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linux/arch/powerpc/kernel/mce.c

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-27 14:55:05 +08:00
// SPDX-License-Identifier: GPL-2.0-or-later
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
/*
* Machine check exception handling.
*
* Copyright 2013 IBM Corporation
* Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
*/
#undef DEBUG
#define pr_fmt(fmt) "mce: " fmt
powerpc/mce: Move 64-bit machine check code into mce.c We already have mce.c which is built for 64bit and contains other parts of the machine check code, so move these bits in there too. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-08 14:39:24 +08:00
#include <linux/hardirq.h>
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/percpu.h>
#include <linux/export.h>
Move precessing of MCE queued event out from syscall exit path. Huge Dickins reported an issue that b5ff4211a829 "powerpc/book3s: Queue up and process delayed MCE events" breaks the PowerMac G5 boot. This patch fixes it by moving the mce even processing away from syscall exit, which was wrong to do that in first place, and using irq work framework to delay processing of mce event. Reported-by: Hugh Dickins <hughd@google.com Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-14 18:15:09 +08:00
#include <linux/irq_work.h>
powerpc/pseries: Handle UE event for memcpy_mcsafe memcpy_mcsafe has been implemented for power machines which is used by pmem infrastructure, so that an UE encountered during memcpy from pmem devices would not result in panic instead a right error code is returned. The implementation expects machine check handler to ignore the event and set nip to continue the execution from fixup code. Appropriate changes are already made to powernv machine check handler, make similar changes to pseries machine check handler to ignore the the event and set nip to continue execution at the fixup entry if we hit UE at an instruction with a fixup entry. while we are at it, have a common function which searches the exception table entry and updates nip with fixup address, and any future common changes can be made in this function that are valid for both architectures. powernv changes are made by commit 895e3dceeb97 ("powerpc/mce: Handle UE event for memcpy_mcsafe") Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reviewed-by: Santosh S <santosh@fossix.org> Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200326184916.31172-1-ganeshgr@linux.ibm.com
2020-03-27 02:49:16 +08:00
#include <linux/extable.h>
powerpc/64s: machine check do not trace real-mode handler Rather than notrace annotations throughout a significant part of the machine check code across kernel/ pseries/ and powernv/ which can easily be broken and is infrequently tested, use paca->ftrace_enabled to blanket-disable tracing of the real-mode non-maskable handler. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Link: https://lore.kernel.org/r/20200508043408.886394-14-npiggin@gmail.com
2020-05-08 12:34:05 +08:00
#include <linux/ftrace.h>
powerpc/mce: Move 64-bit machine check code into mce.c We already have mce.c which is built for 64bit and contains other parts of the machine check code, so move these bits in there too. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-08 14:39:24 +08:00
#include <asm/machdep.h>
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
#include <asm/mce.h>
powerpc/64s: Fix HV NMI vs HV interrupt recoverability test HV interrupts that use HSRR registers do not enter with MSR[RI] clear, but their entry code is not recoverable vs NMI, due to shared use of HSPRG1 as a scratch register to save r13. This means that a system reset or machine check that hits in HSRR interrupt entry can cause r13 to be silently corrupted. Fix this by marking NMIs non-recoverable if they land in HV interrupt ranges. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-26 16:51:07 +08:00
#include <asm/nmi.h>
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
static DEFINE_PER_CPU(int, mce_nest_count);
static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event);
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
/* Queue for delayed MCE events. */
static DEFINE_PER_CPU(int, mce_queue_count);
static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event_queue);
powerpc/mce: hookup memory_failure for UE errors If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:55 +08:00
/* Queue for delayed MCE UE events. */
static DEFINE_PER_CPU(int, mce_ue_count);
static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT],
mce_ue_event_queue);
Move precessing of MCE queued event out from syscall exit path. Huge Dickins reported an issue that b5ff4211a829 "powerpc/book3s: Queue up and process delayed MCE events" breaks the PowerMac G5 boot. This patch fixes it by moving the mce even processing away from syscall exit, which was wrong to do that in first place, and using irq work framework to delay processing of mce event. Reported-by: Hugh Dickins <hughd@google.com Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-14 18:15:09 +08:00
static void machine_check_process_queued_event(struct irq_work *work);
powerpc/mce: Schedule work from irq_work schedule_work() cannot be called from MCE exception context as MCE can interrupt even in interrupt disabled context. Fixes: 733e4a4c4467 ("powerpc/mce: hookup memory_failure for UE errors") Cc: stable@vger.kernel.org # v4.15+ Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Santosh Sivaraj <santosh@fossix.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190820081352.8641-2-santosh@fossix.org
2019-08-20 16:13:46 +08:00
static void machine_check_ue_irq_work(struct irq_work *work);
powerpc/mce: Make machine_check_ue_event() static The function doesn't get used outside this file, so make it static. Signed-off-by: Reza Arbab <arbab@linux.ibm.com> Signed-off-by: Santosh Sivaraj <santosh@fossix.org> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190820081352.8641-4-santosh@fossix.org
2019-08-20 16:13:48 +08:00
static void machine_check_ue_event(struct machine_check_event *evt);
powerpc/mce: hookup memory_failure for UE errors If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:55 +08:00
static void machine_process_ue_event(struct work_struct *work);
powerpc: sparse: static-ify some things As sparse suggests, these should be made static. Signed-off-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-01-06 08:45:50 +08:00
static struct irq_work mce_event_process_work = {
Move precessing of MCE queued event out from syscall exit path. Huge Dickins reported an issue that b5ff4211a829 "powerpc/book3s: Queue up and process delayed MCE events" breaks the PowerMac G5 boot. This patch fixes it by moving the mce even processing away from syscall exit, which was wrong to do that in first place, and using irq work framework to delay processing of mce event. Reported-by: Hugh Dickins <hughd@google.com Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-14 18:15:09 +08:00
.func = machine_check_process_queued_event,
};
powerpc/mce: Schedule work from irq_work schedule_work() cannot be called from MCE exception context as MCE can interrupt even in interrupt disabled context. Fixes: 733e4a4c4467 ("powerpc/mce: hookup memory_failure for UE errors") Cc: stable@vger.kernel.org # v4.15+ Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Santosh Sivaraj <santosh@fossix.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190820081352.8641-2-santosh@fossix.org
2019-08-20 16:13:46 +08:00
static struct irq_work mce_ue_event_irq_work = {
.func = machine_check_ue_irq_work,
};
powerpc/mce: hookup memory_failure for UE errors If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:55 +08:00
DECLARE_WORK(mce_ue_event_work, machine_process_ue_event);
powerpc/mce: Add MCE notification chain Introduce notification chain which lets us know about uncorrected memory errors(UE). This would help prospective users in pmem or nvdimm subsystem to track bad blocks for better handling of persistent memory allocations. Signed-off-by: Santosh Sivaraj <santosh@fossix.org> Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709135142.721504-1-santosh@fossix.org
2020-07-09 21:51:41 +08:00
static BLOCKING_NOTIFIER_HEAD(mce_notifier_list);
int mce_register_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&mce_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(mce_register_notifier);
int mce_unregister_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_unregister(&mce_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(mce_unregister_notifier);
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
static void mce_set_error_info(struct machine_check_event *mce,
struct mce_error_info *mce_err)
{
mce->error_type = mce_err->error_type;
switch (mce_err->error_type) {
case MCE_ERROR_TYPE_UE:
mce->u.ue_error.ue_error_type = mce_err->u.ue_error_type;
break;
case MCE_ERROR_TYPE_SLB:
mce->u.slb_error.slb_error_type = mce_err->u.slb_error_type;
break;
case MCE_ERROR_TYPE_ERAT:
mce->u.erat_error.erat_error_type = mce_err->u.erat_error_type;
break;
case MCE_ERROR_TYPE_TLB:
mce->u.tlb_error.tlb_error_type = mce_err->u.tlb_error_type;
break;
powerpc/64s: POWER9 machine check handler Add POWER9 machine check handler. There are several new types of errors added, so logging messages for those are also added. This doesn't attempt to reuse any of the P7/8 defines or functions, because that becomes too complex. The better option in future is to use a table driven approach. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-28 10:00:48 +08:00
case MCE_ERROR_TYPE_USER:
mce->u.user_error.user_error_type = mce_err->u.user_error_type;
break;
case MCE_ERROR_TYPE_RA:
mce->u.ra_error.ra_error_type = mce_err->u.ra_error_type;
break;
case MCE_ERROR_TYPE_LINK:
mce->u.link_error.link_error_type = mce_err->u.link_error_type;
break;
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
case MCE_ERROR_TYPE_UNKNOWN:
default:
break;
}
}
/*
* Decode and save high level MCE information into per cpu buffer which
* is an array of machine_check_event structure.
*/
void save_mce_event(struct pt_regs *regs, long handled,
struct mce_error_info *mce_err,
powerpc/mce: Hookup derror (load/store) UE errors Extract physical_address for UE errors by walking the page tables for the mm and address at the NIP, to extract the instruction. Then use the instruction to find the effective address via analyse_instr(). We might have page table walking races, but we expect them to be rare, the physical address extraction is best effort. The idea is to then hook up this infrastructure to memory failure eventually. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:53 +08:00
uint64_t nip, uint64_t addr, uint64_t phys_addr)
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
{
powerpc/mce: fix off by one errors in mce event handling Before 69111bac42f5 ("powerpc: Replace __get_cpu_var uses"), in save_mce_event, index got the value of mce_nest_count, and mce_nest_count was incremented *after* index was set. However, that patch changed the behaviour so that mce_nest count was incremented *before* setting index. This causes an off-by-one error, as get_mce_event sets index as mce_nest_count - 1 before reading mce_event. Thus get_mce_event reads bogus data, causing warnings like "Machine Check Exception, Unknown event version 0 !" and breaking MCEs handling. Restore the old behaviour and unbreak MCE handling by subtracting one from the newly incremented value. The same broken change occured in machine_check_queue_event (which set a queue read by machine_check_process_queued_event). Fix that too, unbreaking printing of MCE information. Fixes: 69111bac42f5 ("powerpc: Replace __get_cpu_var uses") CC: stable@vger.kernel.org CC: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> CC: Christoph Lameter <cl@linux.com> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-05-12 11:23:59 +08:00
int index = __this_cpu_inc_return(mce_nest_count) - 1;
powerpc: Replace __get_cpu_var uses This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> Signed-off-by: Christoph Lameter <cl@linux.com> [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-22 04:23:25 +08:00
struct machine_check_event *mce = this_cpu_ptr(&mce_event[index]);
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
/*
* Return if we don't have enough space to log mce event.
* mce_nest_count may go beyond MAX_MC_EVT but that's ok,
* the check below will stop buffer overrun.
*/
if (index >= MAX_MC_EVT)
return;
/* Populate generic machine check info */
mce->version = MCE_V1;
powerpc/book3s: Recover from MC in sapphire on SCOM read via MMIO. Detect and recover from machine check when inside opal on a special scom load instructions. On specific SCOM read via MMIO we may get a machine check exception with SRR0 pointing inside opal. To recover from MC in this scenario, get a recovery instruction address and return to it from MC. OPAL will export the machine check recoverable ranges through device tree node mcheck-recoverable-ranges under ibm,opal: # hexdump /proc/device-tree/ibm,opal/mcheck-recoverable-ranges 0000000 0000 0000 3000 2804 0000 000c 0000 0000 0000010 3000 2814 0000 0000 3000 27f0 0000 000c 0000020 0000 0000 3000 2814 xxxx xxxx xxxx xxxx 0000030 llll llll yyyy yyyy yyyy yyyy ... ... # where: xxxx xxxx xxxx xxxx = Starting instruction address llll llll = Length of the address range. yyyy yyyy yyyy yyyy = recovery address Each recoverable address range entry is (start address, len, recovery address), 2 cells each for start and recovery address, 1 cell for len, totalling 5 cells per entry. During kernel boot time, build up the recovery table with the list of recovery ranges from device-tree node which will be used during machine check exception to recover from MMIO SCOM UE. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-16 13:16:24 +08:00
mce->srr0 = nip;
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
mce->srr1 = regs->msr;
mce->gpr3 = regs->gpr[3];
mce->in_use = 1;
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
mce->cpu = get_paca()->paca_index;
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
powerpc/book3s: Fix MCE console messages for unrecoverable MCE. When machine check occurs with MSR(RI=0), it means MC interrupt is unrecoverable and kernel goes down to panic path. But the console message still shows it as recovered. This patch fixes the MCE console messages. Fixes: 36df96f8acaf ("powerpc/book3s: Decode and save machine check event.") Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-09 13:09:13 +08:00
/* Mark it recovered if we have handled it and MSR(RI=1). */
if (handled && (regs->msr & MSR_RI))
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
mce->disposition = MCE_DISPOSITION_RECOVERED;
else
mce->disposition = MCE_DISPOSITION_NOT_RECOVERED;
powerpc/64s: allow machine check handler to set severity and initiator Currently severity and initiator are always set to MCE_SEV_ERROR_SYNC and MCE_INITIATOR_CPU in the core mce code. Allow them to be set by the machine specific mce handlers. No functional change for existing handlers. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-28 10:00:47 +08:00
mce->initiator = mce_err->initiator;
mce->severity = mce_err->severity;
powerpc/powernv/mce: Print correct severity for MCE error. Currently all machine check errors are printed as severe errors which isn't correct. Print soft errors as warning instead of severe errors. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:55 +08:00
mce->sync_error = mce_err->sync_error;
powerpc/powernv/mce: Print additional information about MCE error. Print more information about MCE error whether it is an hardware or software error. Some of the MCE errors can be easily categorized as hardware or software errors e.g. UEs are due to hardware error, where as error triggered due to invalid usage of tlbie is a pure software bug. But not all the MCE errors can be easily categorize into either software or hardware. There are errors like multihit errors which are usually result of a software bug, but in some rare cases a hardware failure can cause a multihit error. In past, we have seen case where after replacing faulty chip, multihit errors stopped occurring. Same with parity errors, which are usually due to faulty hardware but there are chances where multihit can also cause an parity error. Such errors are difficult to determine what really caused it. Hence this patch classifies MCE errors into following four categorize: 1. Hardware error: UE and Link timeout failure errors. 2. Probable hardware error (some chance of software cause) SLB/ERAT/TLB Parity errors. 3. Software error Invalid tlbie form. 4. Probable software error (some chance of hardware cause) SLB/ERAT/TLB Multihit errors. Sample output: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable Software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:16:02 +08:00
mce->error_class = mce_err->error_class;
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
/*
* Populate the mce error_type and type-specific error_type.
*/
mce_set_error_info(mce, mce_err);
if (!addr)
return;
if (mce->error_type == MCE_ERROR_TYPE_TLB) {
mce->u.tlb_error.effective_address_provided = true;
mce->u.tlb_error.effective_address = addr;
} else if (mce->error_type == MCE_ERROR_TYPE_SLB) {
mce->u.slb_error.effective_address_provided = true;
mce->u.slb_error.effective_address = addr;
} else if (mce->error_type == MCE_ERROR_TYPE_ERAT) {
mce->u.erat_error.effective_address_provided = true;
mce->u.erat_error.effective_address = addr;
powerpc/64s: POWER9 machine check handler Add POWER9 machine check handler. There are several new types of errors added, so logging messages for those are also added. This doesn't attempt to reuse any of the P7/8 defines or functions, because that becomes too complex. The better option in future is to use a table driven approach. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-28 10:00:48 +08:00
} else if (mce->error_type == MCE_ERROR_TYPE_USER) {
mce->u.user_error.effective_address_provided = true;
mce->u.user_error.effective_address = addr;
} else if (mce->error_type == MCE_ERROR_TYPE_RA) {
mce->u.ra_error.effective_address_provided = true;
mce->u.ra_error.effective_address = addr;
} else if (mce->error_type == MCE_ERROR_TYPE_LINK) {
mce->u.link_error.effective_address_provided = true;
mce->u.link_error.effective_address = addr;
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
} else if (mce->error_type == MCE_ERROR_TYPE_UE) {
mce->u.ue_error.effective_address_provided = true;
mce->u.ue_error.effective_address = addr;
powerpc/mce: Hookup derror (load/store) UE errors Extract physical_address for UE errors by walking the page tables for the mm and address at the NIP, to extract the instruction. Then use the instruction to find the effective address via analyse_instr(). We might have page table walking races, but we expect them to be rare, the physical address extraction is best effort. The idea is to then hook up this infrastructure to memory failure eventually. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:53 +08:00
if (phys_addr != ULONG_MAX) {
mce->u.ue_error.physical_address_provided = true;
mce->u.ue_error.physical_address = phys_addr;
powerpc/mce: Handle UE event for memcpy_mcsafe If we take a UE on one of the instructions with a fixup entry, set nip to continue execution at the fixup entry. Stop processing the event further or print it. Co-developed-by: Reza Arbab <arbab@linux.ibm.com> Signed-off-by: Reza Arbab <arbab@linux.ibm.com> Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Santosh Sivaraj <santosh@fossix.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190820081352.8641-6-santosh@fossix.org
2019-08-20 16:13:50 +08:00
mce->u.ue_error.ignore_event = mce_err->ignore_event;
powerpc/mce: hookup memory_failure for UE errors If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:55 +08:00
machine_check_ue_event(mce);
powerpc/mce: Hookup derror (load/store) UE errors Extract physical_address for UE errors by walking the page tables for the mm and address at the NIP, to extract the instruction. Then use the instruction to find the effective address via analyse_instr(). We might have page table walking races, but we expect them to be rare, the physical address extraction is best effort. The idea is to then hook up this infrastructure to memory failure eventually. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:53 +08:00
}
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
}
return;
}
/*
* get_mce_event:
* mce Pointer to machine_check_event structure to be filled.
* release Flag to indicate whether to free the event slot or not.
* 0 <= do not release the mce event. Caller will invoke
* release_mce_event() once event has been consumed.
* 1 <= release the slot.
*
* return 1 = success
* 0 = failure
*
* get_mce_event() will be called by platform specific machine check
* handle routine and in KVM.
* When we call get_mce_event(), we are still in interrupt context and
* preemption will not be scheduled until ret_from_expect() routine
* is called.
*/
int get_mce_event(struct machine_check_event *mce, bool release)
{
powerpc: Replace __get_cpu_var uses This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> Signed-off-by: Christoph Lameter <cl@linux.com> [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-22 04:23:25 +08:00
int index = __this_cpu_read(mce_nest_count) - 1;
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
struct machine_check_event *mc_evt;
int ret = 0;
/* Sanity check */
if (index < 0)
return ret;
/* Check if we have MCE info to process. */
if (index < MAX_MC_EVT) {
powerpc: Replace __get_cpu_var uses This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> Signed-off-by: Christoph Lameter <cl@linux.com> [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-22 04:23:25 +08:00
mc_evt = this_cpu_ptr(&mce_event[index]);
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
/* Copy the event structure and release the original */
if (mce)
*mce = *mc_evt;
if (release)
mc_evt->in_use = 0;
ret = 1;
}
/* Decrement the count to free the slot. */
if (release)
powerpc: Replace __get_cpu_var uses This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> Signed-off-by: Christoph Lameter <cl@linux.com> [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-22 04:23:25 +08:00
__this_cpu_dec(mce_nest_count);
powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:40 +08:00
return ret;
}
void release_mce_event(void)
{
get_mce_event(NULL, true);
}
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
powerpc/mce: Schedule work from irq_work schedule_work() cannot be called from MCE exception context as MCE can interrupt even in interrupt disabled context. Fixes: 733e4a4c4467 ("powerpc/mce: hookup memory_failure for UE errors") Cc: stable@vger.kernel.org # v4.15+ Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Santosh Sivaraj <santosh@fossix.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190820081352.8641-2-santosh@fossix.org
2019-08-20 16:13:46 +08:00
static void machine_check_ue_irq_work(struct irq_work *work)
{
schedule_work(&mce_ue_event_work);
}
powerpc/mce: hookup memory_failure for UE errors If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:55 +08:00
/*
* Queue up the MCE event which then can be handled later.
*/
powerpc/mce: Make machine_check_ue_event() static The function doesn't get used outside this file, so make it static. Signed-off-by: Reza Arbab <arbab@linux.ibm.com> Signed-off-by: Santosh Sivaraj <santosh@fossix.org> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190820081352.8641-4-santosh@fossix.org
2019-08-20 16:13:48 +08:00
static void machine_check_ue_event(struct machine_check_event *evt)
powerpc/mce: hookup memory_failure for UE errors If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:55 +08:00
{
int index;
index = __this_cpu_inc_return(mce_ue_count) - 1;
/* If queue is full, just return for now. */
if (index >= MAX_MC_EVT) {
__this_cpu_dec(mce_ue_count);
return;
}
memcpy(this_cpu_ptr(&mce_ue_event_queue[index]), evt, sizeof(*evt));
/* Queue work to process this event later. */
powerpc/mce: Schedule work from irq_work schedule_work() cannot be called from MCE exception context as MCE can interrupt even in interrupt disabled context. Fixes: 733e4a4c4467 ("powerpc/mce: hookup memory_failure for UE errors") Cc: stable@vger.kernel.org # v4.15+ Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Santosh Sivaraj <santosh@fossix.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190820081352.8641-2-santosh@fossix.org
2019-08-20 16:13:46 +08:00
irq_work_queue(&mce_ue_event_irq_work);
powerpc/mce: hookup memory_failure for UE errors If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:55 +08:00
}
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
/*
* Queue up the MCE event which then can be handled later.
*/
void machine_check_queue_event(void)
{
int index;
struct machine_check_event evt;
if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
return;
powerpc/mce: fix off by one errors in mce event handling Before 69111bac42f5 ("powerpc: Replace __get_cpu_var uses"), in save_mce_event, index got the value of mce_nest_count, and mce_nest_count was incremented *after* index was set. However, that patch changed the behaviour so that mce_nest count was incremented *before* setting index. This causes an off-by-one error, as get_mce_event sets index as mce_nest_count - 1 before reading mce_event. Thus get_mce_event reads bogus data, causing warnings like "Machine Check Exception, Unknown event version 0 !" and breaking MCEs handling. Restore the old behaviour and unbreak MCE handling by subtracting one from the newly incremented value. The same broken change occured in machine_check_queue_event (which set a queue read by machine_check_process_queued_event). Fix that too, unbreaking printing of MCE information. Fixes: 69111bac42f5 ("powerpc: Replace __get_cpu_var uses") CC: stable@vger.kernel.org CC: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> CC: Christoph Lameter <cl@linux.com> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-05-12 11:23:59 +08:00
index = __this_cpu_inc_return(mce_queue_count) - 1;
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
/* If queue is full, just return for now. */
if (index >= MAX_MC_EVT) {
powerpc: Replace __get_cpu_var uses This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> Signed-off-by: Christoph Lameter <cl@linux.com> [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-22 04:23:25 +08:00
__this_cpu_dec(mce_queue_count);
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
return;
}
powerpc: Replace __get_cpu_var uses This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> Signed-off-by: Christoph Lameter <cl@linux.com> [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-22 04:23:25 +08:00
memcpy(this_cpu_ptr(&mce_event_queue[index]), &evt, sizeof(evt));
Move precessing of MCE queued event out from syscall exit path. Huge Dickins reported an issue that b5ff4211a829 "powerpc/book3s: Queue up and process delayed MCE events" breaks the PowerMac G5 boot. This patch fixes it by moving the mce even processing away from syscall exit, which was wrong to do that in first place, and using irq work framework to delay processing of mce event. Reported-by: Hugh Dickins <hughd@google.com Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-14 18:15:09 +08:00
/* Queue irq work to process this event later. */
irq_work_queue(&mce_event_process_work);
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
}
powerpc/pseries: Handle UE event for memcpy_mcsafe memcpy_mcsafe has been implemented for power machines which is used by pmem infrastructure, so that an UE encountered during memcpy from pmem devices would not result in panic instead a right error code is returned. The implementation expects machine check handler to ignore the event and set nip to continue the execution from fixup code. Appropriate changes are already made to powernv machine check handler, make similar changes to pseries machine check handler to ignore the the event and set nip to continue execution at the fixup entry if we hit UE at an instruction with a fixup entry. while we are at it, have a common function which searches the exception table entry and updates nip with fixup address, and any future common changes can be made in this function that are valid for both architectures. powernv changes are made by commit 895e3dceeb97 ("powerpc/mce: Handle UE event for memcpy_mcsafe") Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reviewed-by: Santosh S <santosh@fossix.org> Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200326184916.31172-1-ganeshgr@linux.ibm.com
2020-03-27 02:49:16 +08:00
void mce_common_process_ue(struct pt_regs *regs,
struct mce_error_info *mce_err)
{
const struct exception_table_entry *entry;
entry = search_kernel_exception_table(regs->nip);
if (entry) {
mce_err->ignore_event = true;
regs->nip = extable_fixup(entry);
}
}
powerpc/mce: hookup memory_failure for UE errors If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:55 +08:00
/*
* process pending MCE event from the mce event queue. This function will be
* called during syscall exit.
*/
static void machine_process_ue_event(struct work_struct *work)
{
int index;
struct machine_check_event *evt;
while (__this_cpu_read(mce_ue_count) > 0) {
index = __this_cpu_read(mce_ue_count) - 1;
evt = this_cpu_ptr(&mce_ue_event_queue[index]);
powerpc/mce: Add MCE notification chain Introduce notification chain which lets us know about uncorrected memory errors(UE). This would help prospective users in pmem or nvdimm subsystem to track bad blocks for better handling of persistent memory allocations. Signed-off-by: Santosh Sivaraj <santosh@fossix.org> Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709135142.721504-1-santosh@fossix.org
2020-07-09 21:51:41 +08:00
blocking_notifier_call_chain(&mce_notifier_list, 0, evt);
powerpc/mce: hookup memory_failure for UE errors If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:55 +08:00
#ifdef CONFIG_MEMORY_FAILURE
/*
* This should probably queued elsewhere, but
* oh! well
powerpc/mce: Handle UE event for memcpy_mcsafe If we take a UE on one of the instructions with a fixup entry, set nip to continue execution at the fixup entry. Stop processing the event further or print it. Co-developed-by: Reza Arbab <arbab@linux.ibm.com> Signed-off-by: Reza Arbab <arbab@linux.ibm.com> Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Santosh Sivaraj <santosh@fossix.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190820081352.8641-6-santosh@fossix.org
2019-08-20 16:13:50 +08:00
*
* Don't report this machine check because the caller has a
* asked us to ignore the event, it has a fixup handler which
* will do the appropriate error handling and reporting.
powerpc/mce: hookup memory_failure for UE errors If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:55 +08:00
*/
if (evt->error_type == MCE_ERROR_TYPE_UE) {
powerpc/mce: Handle UE event for memcpy_mcsafe If we take a UE on one of the instructions with a fixup entry, set nip to continue execution at the fixup entry. Stop processing the event further or print it. Co-developed-by: Reza Arbab <arbab@linux.ibm.com> Signed-off-by: Reza Arbab <arbab@linux.ibm.com> Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Santosh Sivaraj <santosh@fossix.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190820081352.8641-6-santosh@fossix.org
2019-08-20 16:13:50 +08:00
if (evt->u.ue_error.ignore_event) {
__this_cpu_dec(mce_ue_count);
continue;
}
powerpc/mce: hookup memory_failure for UE errors If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:55 +08:00
if (evt->u.ue_error.physical_address_provided) {
unsigned long pfn;
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
powerpc/mce: hookup memory_failure for UE errors If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:55 +08:00
pfn = evt->u.ue_error.physical_address >>
PAGE_SHIFT;
Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull siginfo cleanups from Eric Biederman: "Long ago when 2.4 was just a testing release copy_siginfo_to_user was made to copy individual fields to userspace, possibly for efficiency and to ensure initialized values were not copied to userspace. Unfortunately the design was complex, it's assumptions unstated, and humans are fallible and so while it worked much of the time that design failed to ensure unitialized memory is not copied to userspace. This set of changes is part of a new design to clean up siginfo and simplify things, and hopefully make the siginfo handling robust enough that a simple inspection of the code can be made to ensure we don't copy any unitializied fields to userspace. The design is to unify struct siginfo and struct compat_siginfo into a single definition that is shared between all architectures so that anyone adding to the set of information shared with struct siginfo can see the whole picture. Hopefully ensuring all future si_code assignments are arch independent. The design is to unify copy_siginfo_to_user32 and copy_siginfo_from_user32 so that those function are complete and cope with all of the different cases documented in signinfo_layout. I don't think there was a single implementation of either of those functions that was complete and correct before my changes unified them. The design is to introduce a series of helpers including force_siginfo_fault that take the values that are needed in struct siginfo and build the siginfo structure for their callers. Ensuring struct siginfo is built correctly. The remaining work for 4.17 (unless someone thinks it is post -rc1 material) is to push usage of those helpers down into the architectures so that architecture specific code will not need to deal with the fiddly work of intializing struct siginfo, and then when struct siginfo is guaranteed to be fully initialized change copy siginfo_to_user into a simple wrapper around copy_to_user. Further there is work in progress on the issues that have been documented requires arch specific knowledge to sort out. The changes below fix or at least document all of the issues that have been found with siginfo generation. Then proceed to unify struct siginfo the 32 bit helpers that copy siginfo to and from userspace, and generally clean up anything that is not arch specific with regards to siginfo generation. It is a lot but with the unification you can of siginfo you can already see the code reduction in the kernel" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (45 commits) signal/memory-failure: Use force_sig_mceerr and send_sig_mceerr mm/memory_failure: Remove unused trapno from memory_failure signal/ptrace: Add force_sig_ptrace_errno_trap and use it where needed signal/powerpc: Remove unnecessary signal_code parameter of do_send_trap signal: Helpers for faults with specialized siginfo layouts signal: Add send_sig_fault and force_sig_fault signal: Replace memset(info,...) with clear_siginfo for clarity signal: Don't use structure initializers for struct siginfo signal/arm64: Better isolate the COMPAT_TASK portion of ptrace_hbptriggered ptrace: Use copy_siginfo in setsiginfo and getsiginfo signal: Unify and correct copy_siginfo_to_user32 signal: Remove the code to clear siginfo before calling copy_siginfo_from_user32 signal: Unify and correct copy_siginfo_from_user32 signal/blackfin: Remove pointless UID16_SIGINFO_COMPAT_NEEDED signal/blackfin: Move the blackfin specific si_codes to asm-generic/siginfo.h signal/tile: Move the tile specific si_codes to asm-generic/siginfo.h signal/frv: Move the frv specific si_codes to asm-generic/siginfo.h signal/ia64: Move the ia64 specific si_codes to asm-generic/siginfo.h signal/powerpc: Remove redefinition of NSIGTRAP on powerpc signal: Move addr_lsb into the _sigfault union for clarity ...
2018-01-31 06:18:52 +08:00
memory_failure(pfn, 0);
powerpc/mce: hookup memory_failure for UE errors If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:55 +08:00
} else
pr_warn("Failed to identify bad address from "
"where the uncorrectable error (UE) "
"was generated\n");
}
#endif
__this_cpu_dec(mce_ue_count);
}
}
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
/*
* process pending MCE event from the mce event queue. This function will be
* called during syscall exit.
*/
Move precessing of MCE queued event out from syscall exit path. Huge Dickins reported an issue that b5ff4211a829 "powerpc/book3s: Queue up and process delayed MCE events" breaks the PowerMac G5 boot. This patch fixes it by moving the mce even processing away from syscall exit, which was wrong to do that in first place, and using irq work framework to delay processing of mce event. Reported-by: Hugh Dickins <hughd@google.com Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-14 18:15:09 +08:00
static void machine_check_process_queued_event(struct irq_work *work)
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
{
int index;
powerpc/mce: hookup memory_failure for UE errors If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:55 +08:00
struct machine_check_event *evt;
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
powerpc/book3s/mce: Move add_taint() later in virtual mode machine_check_early() gets called in real mode. The very first time when add_taint() is called, it prints a warning which ends up calling opal call (that uses OPAL_CALL wrapper) for writing it to console. If we get a very first machine check while we are in opal we are doomed. OPAL_CALL overwrites the PACASAVEDMSR in r13 and in this case when we are done with MCE handling the original opal call will use this new MSR on it's way back to opal_return. This usually leads to unexpected behaviour or the kernel to panic. Instead move the add_taint() call later in the virtual mode where it is safe to call. This is broken with current FW level. We got lucky so far for not getting very first MCE hit while in OPAL. But easily reproducible on Mambo. Fixes: 27ea2c420cad ("powerpc: Set the correct kernel taint on machine check errors.") Cc: stable@vger.kernel.org # v4.2+ Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-19 00:38:17 +08:00
add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
/*
* For now just print it to console.
* TODO: log this error event to FSP or nvram.
*/
powerpc: Replace __get_cpu_var uses This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> Signed-off-by: Christoph Lameter <cl@linux.com> [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-22 04:23:25 +08:00
while (__this_cpu_read(mce_queue_count) > 0) {
index = __this_cpu_read(mce_queue_count) - 1;
powerpc/mce: hookup memory_failure for UE errors If we are in user space and hit a UE error, we now have the basic infrastructure to walk the page tables and find out the effective address that was accessed, since the DAR is not valid. We use a work_queue content to hookup the bad pfn, any other context causes problems, since memory_failure itself can call into schedule() via lru_drain_ bits. We could probably poison the struct page to avoid a race between detection and taking corrective action. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 12:26:55 +08:00
evt = this_cpu_ptr(&mce_event_queue[index]);
powerpc/mce: Handle UE event for memcpy_mcsafe If we take a UE on one of the instructions with a fixup entry, set nip to continue execution at the fixup entry. Stop processing the event further or print it. Co-developed-by: Reza Arbab <arbab@linux.ibm.com> Signed-off-by: Reza Arbab <arbab@linux.ibm.com> Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Santosh Sivaraj <santosh@fossix.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190820081352.8641-6-santosh@fossix.org
2019-08-20 16:13:50 +08:00
if (evt->error_type == MCE_ERROR_TYPE_UE &&
evt->u.ue_error.ignore_event) {
__this_cpu_dec(mce_queue_count);
continue;
}
powerpc/64s: Better printing of machine check info for guest MCEs This adds an "in_guest" parameter to machine_check_print_event_info() so that we can avoid trying to translate guest NIP values into symbolic form using the host kernel's symbol table. Reviewed-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-21 10:40:20 +08:00
machine_check_print_event_info(evt, false, false);
powerpc: Replace __get_cpu_var uses This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> Signed-off-by: Christoph Lameter <cl@linux.com> [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-22 04:23:25 +08:00
__this_cpu_dec(mce_queue_count);
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
}
}
powerpc/book3s: Print task info if we take a machine check in user mode For an MCE (Machine Check Exception) that hits while in user mode MSR(PR=1), print the task info to the console MCE error log. This may help to identify an application that triggered the MCE. After this patch the MCE console looks like: Severe Machine check interrupt [Recovered] NIP: [0000000010039778] PID: 762 Comm: ebizzy Initiator: CPU Error type: SLB [Multihit] Effective address: 0000000010039778 Severe Machine check interrupt [Not recovered] NIP: [0000000010039778] PID: 763 Comm: ebizzy Initiator: CPU Error type: UE [Page table walk ifetch] Effective address: 0000000010039778 ebizzy[763]: unhandled signal 7 at 0000000010039778 nip 0000000010039778 lr 0000000010001b44 code 30004 Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-03 13:29:34 +08:00
void machine_check_print_event_info(struct machine_check_event *evt,
powerpc/64s: Better printing of machine check info for guest MCEs This adds an "in_guest" parameter to machine_check_print_event_info() so that we can avoid trying to translate guest NIP values into symbolic form using the host kernel's symbol table. Reviewed-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-21 10:40:20 +08:00
bool user_mode, bool in_guest)
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
{
powerpc/64s/pseries: machine check convert to use common event code The common machine_check_event data structures and queues are mostly platform independent, with powernv decoding SRR1/DSISR/etc., into machine_check_event objects. This patch converts pseries to use this infrastructure by decoding fwnmi/rtas data into machine_check_event objects. This allows queueing to be used by a subsequent change to delay the virtual mode handling of machine checks that occur in kernel space where it is unsafe to switch immediately to virtual mode, similarly to powernv. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fix implicit fallthrough warnings in mce_handle_error()] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190802105709.27696-10-npiggin@gmail.com
2019-08-02 18:56:34 +08:00
const char *level, *sevstr, *subtype, *err_type, *initiator;
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
uint64_t ea = 0, pa = 0;
int n = 0;
char dar_str[50];
char pa_str[50];
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
static const char *mc_ue_types[] = {
"Indeterminate",
"Instruction fetch",
"Page table walk ifetch",
"Load/Store",
"Page table walk Load/Store",
};
static const char *mc_slb_types[] = {
"Indeterminate",
"Parity",
"Multihit",
};
static const char *mc_erat_types[] = {
"Indeterminate",
"Parity",
"Multihit",
};
static const char *mc_tlb_types[] = {
"Indeterminate",
"Parity",
"Multihit",
};
powerpc/64s: POWER9 machine check handler Add POWER9 machine check handler. There are several new types of errors added, so logging messages for those are also added. This doesn't attempt to reuse any of the P7/8 defines or functions, because that becomes too complex. The better option in future is to use a table driven approach. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-28 10:00:48 +08:00
static const char *mc_user_types[] = {
"Indeterminate",
"tlbie(l) invalid",
powerpc/powernv: Machine check handler for POWER10 Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200702233343.1128026-1-npiggin@gmail.com
2020-07-03 07:33:43 +08:00
"scv invalid",
powerpc/64s: POWER9 machine check handler Add POWER9 machine check handler. There are several new types of errors added, so logging messages for those are also added. This doesn't attempt to reuse any of the P7/8 defines or functions, because that becomes too complex. The better option in future is to use a table driven approach. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-28 10:00:48 +08:00
};
static const char *mc_ra_types[] = {
"Indeterminate",
"Instruction fetch (bad)",
powerpc/64s: Machine check handle ifetch from foreign real address for POWER9 The i-side 0111b machine check, which is "Instruction Fetch to foreign address space", was missed by 7b9f71f974 ("powerpc/64s: POWER9 machine check handler"). The POWER9 processor core considers host real addresses with a nonzero value in RA(8:12) as foreign address space, accessible only by the copy and paste instructions. The copy and paste instruction pair can be used to invoke the Nest accelerators via the Virtual Accelerator Switchboard (VAS). It is an error for any regular load/store or ifetch to go to a foreign addresses. When relocation is on, this causes an MMU exception. When relocation is off, a machine check exception. It is possible to trigger this machine check by branching to a foreign address with MSR[IR]=0. Fixes: 7b9f71f974a1 ("powerpc/64s: POWER9 machine check handler") Reported-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-05-29 14:26:44 +08:00
"Instruction fetch (foreign)",
powerpc/64s: POWER9 machine check handler Add POWER9 machine check handler. There are several new types of errors added, so logging messages for those are also added. This doesn't attempt to reuse any of the P7/8 defines or functions, because that becomes too complex. The better option in future is to use a table driven approach. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-28 10:00:48 +08:00
"Page table walk ifetch (bad)",
"Page table walk ifetch (foreign)",
"Load (bad)",
"Store (bad)",
"Page table walk Load/Store (bad)",
"Page table walk Load/Store (foreign)",
"Load/Store (foreign)",
};
static const char *mc_link_types[] = {
"Indeterminate",
"Instruction fetch (timeout)",
"Page table walk ifetch (timeout)",
"Load (timeout)",
"Store (timeout)",
"Page table walk Load/Store (timeout)",
};
powerpc/powernv/mce: Print additional information about MCE error. Print more information about MCE error whether it is an hardware or software error. Some of the MCE errors can be easily categorized as hardware or software errors e.g. UEs are due to hardware error, where as error triggered due to invalid usage of tlbie is a pure software bug. But not all the MCE errors can be easily categorize into either software or hardware. There are errors like multihit errors which are usually result of a software bug, but in some rare cases a hardware failure can cause a multihit error. In past, we have seen case where after replacing faulty chip, multihit errors stopped occurring. Same with parity errors, which are usually due to faulty hardware but there are chances where multihit can also cause an parity error. Such errors are difficult to determine what really caused it. Hence this patch classifies MCE errors into following four categorize: 1. Hardware error: UE and Link timeout failure errors. 2. Probable hardware error (some chance of software cause) SLB/ERAT/TLB Parity errors. 3. Software error Invalid tlbie form. 4. Probable software error (some chance of hardware cause) SLB/ERAT/TLB Multihit errors. Sample output: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable Software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:16:02 +08:00
static const char *mc_error_class[] = {
"Unknown",
"Hardware error",
"Probable Hardware error (some chance of software cause)",
"Software error",
"Probable Software error (some chance of hardware cause)",
};
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
/* Print things out */
if (evt->version != MCE_V1) {
pr_err("Machine Check Exception, Unknown event version %d !\n",
evt->version);
return;
}
switch (evt->severity) {
case MCE_SEV_NO_ERROR:
level = KERN_INFO;
sevstr = "Harmless";
break;
case MCE_SEV_WARNING:
level = KERN_WARNING;
powerpc/powernv/mce: Print correct severity for MCE error. Currently all machine check errors are printed as severe errors which isn't correct. Print soft errors as warning instead of severe errors. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:55 +08:00
sevstr = "Warning";
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
break;
powerpc/powernv/mce: Print correct severity for MCE error. Currently all machine check errors are printed as severe errors which isn't correct. Print soft errors as warning instead of severe errors. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:55 +08:00
case MCE_SEV_SEVERE:
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
level = KERN_ERR;
sevstr = "Severe";
break;
case MCE_SEV_FATAL:
default:
level = KERN_ERR;
sevstr = "Fatal";
break;
}
powerpc/64s/pseries: machine check convert to use common event code The common machine_check_event data structures and queues are mostly platform independent, with powernv decoding SRR1/DSISR/etc., into machine_check_event objects. This patch converts pseries to use this infrastructure by decoding fwnmi/rtas data into machine_check_event objects. This allows queueing to be used by a subsequent change to delay the virtual mode handling of machine checks that occur in kernel space where it is unsafe to switch immediately to virtual mode, similarly to powernv. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fix implicit fallthrough warnings in mce_handle_error()] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190802105709.27696-10-npiggin@gmail.com
2019-08-02 18:56:34 +08:00
switch(evt->initiator) {
case MCE_INITIATOR_CPU:
initiator = "CPU";
break;
case MCE_INITIATOR_PCI:
initiator = "PCI";
break;
case MCE_INITIATOR_ISA:
initiator = "ISA";
break;
case MCE_INITIATOR_MEMORY:
initiator = "Memory";
break;
case MCE_INITIATOR_POWERMGM:
initiator = "Power Management";
break;
case MCE_INITIATOR_UNKNOWN:
default:
initiator = "Unknown";
break;
}
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
switch (evt->error_type) {
case MCE_ERROR_TYPE_UE:
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
err_type = "UE";
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
subtype = evt->u.ue_error.ue_error_type <
ARRAY_SIZE(mc_ue_types) ?
mc_ue_types[evt->u.ue_error.ue_error_type]
: "Unknown";
if (evt->u.ue_error.effective_address_provided)
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
ea = evt->u.ue_error.effective_address;
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
if (evt->u.ue_error.physical_address_provided)
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
pa = evt->u.ue_error.physical_address;
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
break;
case MCE_ERROR_TYPE_SLB:
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
err_type = "SLB";
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
subtype = evt->u.slb_error.slb_error_type <
ARRAY_SIZE(mc_slb_types) ?
mc_slb_types[evt->u.slb_error.slb_error_type]
: "Unknown";
if (evt->u.slb_error.effective_address_provided)
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
ea = evt->u.slb_error.effective_address;
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
break;
case MCE_ERROR_TYPE_ERAT:
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
err_type = "ERAT";
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
subtype = evt->u.erat_error.erat_error_type <
ARRAY_SIZE(mc_erat_types) ?
mc_erat_types[evt->u.erat_error.erat_error_type]
: "Unknown";
if (evt->u.erat_error.effective_address_provided)
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
ea = evt->u.erat_error.effective_address;
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
break;
case MCE_ERROR_TYPE_TLB:
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
err_type = "TLB";
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
subtype = evt->u.tlb_error.tlb_error_type <
ARRAY_SIZE(mc_tlb_types) ?
mc_tlb_types[evt->u.tlb_error.tlb_error_type]
: "Unknown";
if (evt->u.tlb_error.effective_address_provided)
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
ea = evt->u.tlb_error.effective_address;
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
break;
powerpc/64s: POWER9 machine check handler Add POWER9 machine check handler. There are several new types of errors added, so logging messages for those are also added. This doesn't attempt to reuse any of the P7/8 defines or functions, because that becomes too complex. The better option in future is to use a table driven approach. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-28 10:00:48 +08:00
case MCE_ERROR_TYPE_USER:
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
err_type = "User";
powerpc/64s: POWER9 machine check handler Add POWER9 machine check handler. There are several new types of errors added, so logging messages for those are also added. This doesn't attempt to reuse any of the P7/8 defines or functions, because that becomes too complex. The better option in future is to use a table driven approach. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-28 10:00:48 +08:00
subtype = evt->u.user_error.user_error_type <
ARRAY_SIZE(mc_user_types) ?
mc_user_types[evt->u.user_error.user_error_type]
: "Unknown";
if (evt->u.user_error.effective_address_provided)
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
ea = evt->u.user_error.effective_address;
powerpc/64s: POWER9 machine check handler Add POWER9 machine check handler. There are several new types of errors added, so logging messages for those are also added. This doesn't attempt to reuse any of the P7/8 defines or functions, because that becomes too complex. The better option in future is to use a table driven approach. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-28 10:00:48 +08:00
break;
case MCE_ERROR_TYPE_RA:
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
err_type = "Real address";
powerpc/64s: POWER9 machine check handler Add POWER9 machine check handler. There are several new types of errors added, so logging messages for those are also added. This doesn't attempt to reuse any of the P7/8 defines or functions, because that becomes too complex. The better option in future is to use a table driven approach. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-28 10:00:48 +08:00
subtype = evt->u.ra_error.ra_error_type <
ARRAY_SIZE(mc_ra_types) ?
mc_ra_types[evt->u.ra_error.ra_error_type]
: "Unknown";
if (evt->u.ra_error.effective_address_provided)
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
ea = evt->u.ra_error.effective_address;
powerpc/64s: POWER9 machine check handler Add POWER9 machine check handler. There are several new types of errors added, so logging messages for those are also added. This doesn't attempt to reuse any of the P7/8 defines or functions, because that becomes too complex. The better option in future is to use a table driven approach. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-28 10:00:48 +08:00
break;
case MCE_ERROR_TYPE_LINK:
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
err_type = "Link";
powerpc/64s: POWER9 machine check handler Add POWER9 machine check handler. There are several new types of errors added, so logging messages for those are also added. This doesn't attempt to reuse any of the P7/8 defines or functions, because that becomes too complex. The better option in future is to use a table driven approach. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-28 10:00:48 +08:00
subtype = evt->u.link_error.link_error_type <
ARRAY_SIZE(mc_link_types) ?
mc_link_types[evt->u.link_error.link_error_type]
: "Unknown";
if (evt->u.link_error.effective_address_provided)
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
ea = evt->u.link_error.effective_address;
powerpc/64s: POWER9 machine check handler Add POWER9 machine check handler. There are several new types of errors added, so logging messages for those are also added. This doesn't attempt to reuse any of the P7/8 defines or functions, because that becomes too complex. The better option in future is to use a table driven approach. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-28 10:00:48 +08:00
break;
powerpc/64s/pseries: machine check convert to use common event code The common machine_check_event data structures and queues are mostly platform independent, with powernv decoding SRR1/DSISR/etc., into machine_check_event objects. This patch converts pseries to use this infrastructure by decoding fwnmi/rtas data into machine_check_event objects. This allows queueing to be used by a subsequent change to delay the virtual mode handling of machine checks that occur in kernel space where it is unsafe to switch immediately to virtual mode, similarly to powernv. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fix implicit fallthrough warnings in mce_handle_error()] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190802105709.27696-10-npiggin@gmail.com
2019-08-02 18:56:34 +08:00
case MCE_ERROR_TYPE_DCACHE:
err_type = "D-Cache";
subtype = "Unknown";
break;
case MCE_ERROR_TYPE_ICACHE:
err_type = "I-Cache";
subtype = "Unknown";
break;
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
default:
case MCE_ERROR_TYPE_UNKNOWN:
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
err_type = "Unknown";
subtype = "";
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
break;
}
powerpc/powernv/mce: Reduce MCE console logs to lesser lines. Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:15:48 +08:00
dar_str[0] = pa_str[0] = '\0';
if (ea && evt->srr0 != ea) {
/* Load/Store address */
n = sprintf(dar_str, "DAR: %016llx ", ea);
if (pa)
sprintf(dar_str + n, "paddr: %016llx ", pa);
} else if (pa) {
sprintf(pa_str, " paddr: %016llx", pa);
}
printk("%sMCE: CPU%d: machine check (%s) %s %s %s %s[%s]\n",
level, evt->cpu, sevstr, in_guest ? "Guest" : "Host",
err_type, subtype, dar_str,
evt->disposition == MCE_DISPOSITION_RECOVERED ?
"Recovered" : "Not recovered");
if (in_guest || user_mode) {
printk("%sMCE: CPU%d: PID: %d Comm: %s %sNIP: [%016llx]%s\n",
level, evt->cpu, current->pid, current->comm,
in_guest ? "Guest " : "", evt->srr0, pa_str);
} else {
printk("%sMCE: CPU%d: NIP: [%016llx] %pS%s\n",
level, evt->cpu, evt->srr0, (void *)evt->srr0, pa_str);
}
powerpc/powernv/mce: Print additional information about MCE error. Print more information about MCE error whether it is an hardware or software error. Some of the MCE errors can be easily categorized as hardware or software errors e.g. UEs are due to hardware error, where as error triggered due to invalid usage of tlbie is a pure software bug. But not all the MCE errors can be easily categorize into either software or hardware. There are errors like multihit errors which are usually result of a software bug, but in some rare cases a hardware failure can cause a multihit error. In past, we have seen case where after replacing faulty chip, multihit errors stopped occurring. Same with parity errors, which are usually due to faulty hardware but there are chances where multihit can also cause an parity error. Such errors are difficult to determine what really caused it. Hence this patch classifies MCE errors into following four categorize: 1. Hardware error: UE and Link timeout failure errors. 2. Probable hardware error (some chance of software cause) SLB/ERAT/TLB Parity errors. 3. Software error Invalid tlbie form. 4. Probable software error (some chance of hardware cause) SLB/ERAT/TLB Multihit errors. Sample output: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable Software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:16:02 +08:00
powerpc/64s/pseries: machine check convert to use common event code The common machine_check_event data structures and queues are mostly platform independent, with powernv decoding SRR1/DSISR/etc., into machine_check_event objects. This patch converts pseries to use this infrastructure by decoding fwnmi/rtas data into machine_check_event objects. This allows queueing to be used by a subsequent change to delay the virtual mode handling of machine checks that occur in kernel space where it is unsafe to switch immediately to virtual mode, similarly to powernv. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fix implicit fallthrough warnings in mce_handle_error()] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190802105709.27696-10-npiggin@gmail.com
2019-08-02 18:56:34 +08:00
printk("%sMCE: CPU%d: Initiator %s\n", level, evt->cpu, initiator);
powerpc/powernv/mce: Print additional information about MCE error. Print more information about MCE error whether it is an hardware or software error. Some of the MCE errors can be easily categorized as hardware or software errors e.g. UEs are due to hardware error, where as error triggered due to invalid usage of tlbie is a pure software bug. But not all the MCE errors can be easily categorize into either software or hardware. There are errors like multihit errors which are usually result of a software bug, but in some rare cases a hardware failure can cause a multihit error. In past, we have seen case where after replacing faulty chip, multihit errors stopped occurring. Same with parity errors, which are usually due to faulty hardware but there are chances where multihit can also cause an parity error. Such errors are difficult to determine what really caused it. Hence this patch classifies MCE errors into following four categorize: 1. Hardware error: UE and Link timeout failure errors. 2. Probable hardware error (some chance of software cause) SLB/ERAT/TLB Parity errors. 3. Software error Invalid tlbie form. 4. Probable software error (some chance of hardware cause) SLB/ERAT/TLB Multihit errors. Sample output: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable Software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 02:16:02 +08:00
subtype = evt->error_class < ARRAY_SIZE(mc_error_class) ?
mc_error_class[evt->error_class] : "Unknown";
printk("%sMCE: CPU%d: %s\n", level, evt->cpu, subtype);
powerpc/64s/powernv: machine check dump SLB contents Re-use the code introduced in pseries to save and dump the contents of the SLB in the case of an SLB involved machine check exception. This patch also avoids allocating the SLB save array on pseries radix. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190802105709.27696-9-npiggin@gmail.com
2019-08-02 18:56:33 +08:00
#ifdef CONFIG_PPC_BOOK3S_64
/* Display faulty slb contents for SLB errors. */
if (evt->error_type == MCE_ERROR_TYPE_SLB)
slb_dump_contents(local_paca->mce_faulty_slbs);
#endif
powerpc/book3s: Queue up and process delayed MCE events. When machine check real mode handler can not continue into host kernel in V mode, it returns from the interrupt and we loose MCE event which never gets logged. In such a situation queue up the MCE event so that we can log it later when we get back into host kernel with r1 pointing to kernel stack e.g. during syscall exit. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:35:49 +08:00
}
powerpc/book3s: EXPORT_SYMBOL_GPL machine_check_print_event_info It will be used in arch/powerpc/kvm/book3s_hv.c KVM module. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-05-11 19:03:12 +08:00
EXPORT_SYMBOL_GPL(machine_check_print_event_info);
powerpc/powernv: Machine check exception handling. Add basic error handling in machine check exception handler. - If MSR_RI isn't set, we can not recover. - Check if disposition set to OpalMCE_DISPOSITION_RECOVERED. - Check if address at fault is inside kernel address space, if not then send SIGBUS to process if we hit exception when in userspace. - If address at fault is not provided then and if we get a synchronous machine check while in userspace then kill the task. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 22:36:13 +08:00
powerpc/mce: Move 64-bit machine check code into mce.c We already have mce.c which is built for 64bit and contains other parts of the machine check code, so move these bits in there too. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-08 14:39:24 +08:00
/*
* This function is called in real mode. Strictly no printk's please.
*
* regs->nip and regs->msr contains srr0 and ssr1.
*/
powerpc/64s: machine check do not trace real-mode handler Rather than notrace annotations throughout a significant part of the machine check code across kernel/ pseries/ and powernv/ which can easily be broken and is infrequently tested, use paca->ftrace_enabled to blanket-disable tracing of the real-mode non-maskable handler. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Link: https://lore.kernel.org/r/20200508043408.886394-14-npiggin@gmail.com
2020-05-08 12:34:05 +08:00
long notrace machine_check_early(struct pt_regs *regs)
powerpc/mce: Move 64-bit machine check code into mce.c We already have mce.c which is built for 64bit and contains other parts of the machine check code, so move these bits in there too. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-08 14:39:24 +08:00
{
long handled = 0;
powerpc/64s: machine check interrupt update NMI accounting machine_check_early() is taken as an NMI, so nmi_enter() is used there. machine_check_exception() is no longer taken as an NMI (it's invoked via irq_work in the case a machine check hits in kernel mode), so remove the nmi_enter() from that case. In NMI context, hash faults don't try to refill the hash table, which can lead to crashes accessing non-pinned kernel pages. System reset still has this potential problem. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Drop change in show_regs() which breaks Book3E] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200508043408.886394-12-npiggin@gmail.com
2020-05-08 12:34:03 +08:00
bool nested = in_nmi();
powerpc/64s: machine check do not trace real-mode handler Rather than notrace annotations throughout a significant part of the machine check code across kernel/ pseries/ and powernv/ which can easily be broken and is infrequently tested, use paca->ftrace_enabled to blanket-disable tracing of the real-mode non-maskable handler. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Link: https://lore.kernel.org/r/20200508043408.886394-14-npiggin@gmail.com
2020-05-08 12:34:05 +08:00
u8 ftrace_enabled = this_cpu_get_ftrace_enabled();
this_cpu_set_ftrace_enabled(0);
powerpc/64s: machine check interrupt update NMI accounting machine_check_early() is taken as an NMI, so nmi_enter() is used there. machine_check_exception() is no longer taken as an NMI (it's invoked via irq_work in the case a machine check hits in kernel mode), so remove the nmi_enter() from that case. In NMI context, hash faults don't try to refill the hash table, which can lead to crashes accessing non-pinned kernel pages. System reset still has this potential problem. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Drop change in show_regs() which breaks Book3E] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200508043408.886394-12-npiggin@gmail.com
2020-05-08 12:34:03 +08:00
if (!nested)
nmi_enter();
powerpc/mce: Move 64-bit machine check code into mce.c We already have mce.c which is built for 64bit and contains other parts of the machine check code, so move these bits in there too. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-08 14:39:24 +08:00
powerpc/64s: Fix HV NMI vs HV interrupt recoverability test HV interrupts that use HSRR registers do not enter with MSR[RI] clear, but their entry code is not recoverable vs NMI, due to shared use of HSPRG1 as a scratch register to save r13. This means that a system reset or machine check that hits in HSRR interrupt entry can cause r13 to be silently corrupted. Fix this by marking NMIs non-recoverable if they land in HV interrupt ranges. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-26 16:51:07 +08:00
hv_nmi_check_nonrecoverable(regs);
powerpc/pseries: Flush SLB contents on SLB MCE errors. On pseries, as of today system crashes if we get a machine check exceptions due to SLB errors. These are soft errors and can be fixed by flushing the SLBs so the kernel can continue to function instead of system crash. We do this in real mode before turning on MMU. Otherwise we would run into nested machine checks. This patch now fetches the rtas error log in real mode and flushes the SLBs on SLB/ERAT errors. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michal Suchanek <msuchanek@suse.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-11 22:27:00 +08:00
/*
* See if platform is capable of handling machine check.
*/
if (ppc_md.machine_check_early)
handled = ppc_md.machine_check_early(regs);
powerpc/64s: machine check interrupt update NMI accounting machine_check_early() is taken as an NMI, so nmi_enter() is used there. machine_check_exception() is no longer taken as an NMI (it's invoked via irq_work in the case a machine check hits in kernel mode), so remove the nmi_enter() from that case. In NMI context, hash faults don't try to refill the hash table, which can lead to crashes accessing non-pinned kernel pages. System reset still has this potential problem. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Drop change in show_regs() which breaks Book3E] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200508043408.886394-12-npiggin@gmail.com
2020-05-08 12:34:03 +08:00
if (!nested)
nmi_exit();
powerpc/64s: machine check do not trace real-mode handler Rather than notrace annotations throughout a significant part of the machine check code across kernel/ pseries/ and powernv/ which can easily be broken and is infrequently tested, use paca->ftrace_enabled to blanket-disable tracing of the real-mode non-maskable handler. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Link: https://lore.kernel.org/r/20200508043408.886394-14-npiggin@gmail.com
2020-05-08 12:34:05 +08:00
this_cpu_set_ftrace_enabled(ftrace_enabled);
powerpc/mce: Move 64-bit machine check code into mce.c We already have mce.c which is built for 64bit and contains other parts of the machine check code, so move these bits in there too. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-08 14:39:24 +08:00
return handled;
}
KVM: PPC: Book3S HV: Improve handling of debug-trigger HMIs on POWER9 Hypervisor maintenance interrupts (HMIs) are generated by various causes, signalled by bits in the hypervisor maintenance exception register (HMER). In most cases calling OPAL to handle the interrupt is the correct thing to do, but the "debug trigger" HMIs signalled by PPC bit 17 (bit 46) of HMER are used to invoke software workarounds for hardware bugs, and OPAL does not have any code to handle this cause. The debug trigger HMI is used in POWER9 DD2.0 and DD2.1 chips to work around a hardware bug in executing vector load instructions to cache inhibited memory. In POWER9 DD2.2 chips, it is generated when conditions are detected relating to threads being in TM (transactional memory) suspended mode when the core SMT configuration needs to be reconfigured. The kernel currently has code to detect the vector CI load condition, but only when the HMI occurs in the host, not when it occurs in a guest. If a HMI occurs in the guest, it is always passed to OPAL, and then we always re-sync the timebase, because the HMI cause might have been a timebase error, for which OPAL would re-sync the timebase, thus removing the timebase offset which KVM applied for the guest. Since we don't know what OPAL did, we don't know whether to subtract the timebase offset from the timebase, so instead we re-sync the timebase. This adds code to determine explicitly what the cause of a debug trigger HMI will be. This is based on a new device-tree property under the CPU nodes called ibm,hmi-special-triggers, if it is present, or otherwise based on the PVR (processor version register). The handling of debug trigger HMIs is pulled out into a separate function which can be called from the KVM guest exit code. If this function handles and clears the HMI, and no other HMI causes remain, then we skip calling OPAL and we proceed to subtract the guest timebase offset from the timebase. The overall handling for HMIs that occur in the host (i.e. not in a KVM guest) is largely unchanged, except that we now don't set the flag for the vector CI load workaround on DD2.2 processors. This also removes a BUG_ON in the KVM code. BUG_ON is generally not useful in KVM guest entry/exit code since it is difficult to handle the resulting trap gracefully. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-17 17:51:13 +08:00
/* Possible meanings for HMER_DEBUG_TRIG bit being set on POWER9 */
static enum {
DTRIG_UNKNOWN,
DTRIG_VECTOR_CI, /* need to emulate vector CI load instr */
DTRIG_SUSPEND_ESCAPE, /* need to escape from TM suspend mode */
} hmer_debug_trig_function;
static int init_debug_trig_function(void)
powerpc/mce: Move 64-bit machine check code into mce.c We already have mce.c which is built for 64bit and contains other parts of the machine check code, so move these bits in there too. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-08 14:39:24 +08:00
{
KVM: PPC: Book3S HV: Improve handling of debug-trigger HMIs on POWER9 Hypervisor maintenance interrupts (HMIs) are generated by various causes, signalled by bits in the hypervisor maintenance exception register (HMER). In most cases calling OPAL to handle the interrupt is the correct thing to do, but the "debug trigger" HMIs signalled by PPC bit 17 (bit 46) of HMER are used to invoke software workarounds for hardware bugs, and OPAL does not have any code to handle this cause. The debug trigger HMI is used in POWER9 DD2.0 and DD2.1 chips to work around a hardware bug in executing vector load instructions to cache inhibited memory. In POWER9 DD2.2 chips, it is generated when conditions are detected relating to threads being in TM (transactional memory) suspended mode when the core SMT configuration needs to be reconfigured. The kernel currently has code to detect the vector CI load condition, but only when the HMI occurs in the host, not when it occurs in a guest. If a HMI occurs in the guest, it is always passed to OPAL, and then we always re-sync the timebase, because the HMI cause might have been a timebase error, for which OPAL would re-sync the timebase, thus removing the timebase offset which KVM applied for the guest. Since we don't know what OPAL did, we don't know whether to subtract the timebase offset from the timebase, so instead we re-sync the timebase. This adds code to determine explicitly what the cause of a debug trigger HMI will be. This is based on a new device-tree property under the CPU nodes called ibm,hmi-special-triggers, if it is present, or otherwise based on the PVR (processor version register). The handling of debug trigger HMIs is pulled out into a separate function which can be called from the KVM guest exit code. If this function handles and clears the HMI, and no other HMI causes remain, then we skip calling OPAL and we proceed to subtract the guest timebase offset from the timebase. The overall handling for HMIs that occur in the host (i.e. not in a KVM guest) is largely unchanged, except that we now don't set the flag for the vector CI load workaround on DD2.2 processors. This also removes a BUG_ON in the KVM code. BUG_ON is generally not useful in KVM guest entry/exit code since it is difficult to handle the resulting trap gracefully. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-17 17:51:13 +08:00
int pvr;
struct device_node *cpun;
struct property *prop = NULL;
const char *str;
/* First look in the device tree */
preempt_disable();
cpun = of_get_cpu_node(smp_processor_id(), NULL);
if (cpun) {
of_property_for_each_string(cpun, "ibm,hmi-special-triggers",
prop, str) {
if (strcmp(str, "bit17-vector-ci-load") == 0)
hmer_debug_trig_function = DTRIG_VECTOR_CI;
else if (strcmp(str, "bit17-tm-suspend-escape") == 0)
hmer_debug_trig_function = DTRIG_SUSPEND_ESCAPE;
powerpc/64s: Add workaround for P9 vector CI load issue POWER9 DD2.1 and earlier has an issue where some cache inhibited vector load will return bad data. The workaround is two part, one firmware/microcode part triggers HMI interrupts when hitting such loads, the other part is this patch which then emulates the instructions in Linux. The affected instructions are limited to lxvd2x, lxvw4x, lxvb16x and lxvh8x. When an instruction triggers the HMI, all threads in the core will be sent to the HMI handler, not just the one running the vector load. In general, these spurious HMIs are detected by the emulation code and we just return back to the running process. Unfortunately, if a spurious interrupt occurs on a vector load that's to normal memory we have no way to detect that it's spurious (unless we walk the page tables, which is very expensive). In this case we emulate the load but we need do so using a vector load itself to ensure 128bit atomicity is preserved. Some additional debugfs emulated instruction counters are added also. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Switch CONFIG_PPC_BOOK3S_64 to CONFIG_VSX to unbreak the build] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-15 13:25:48 +08:00
}
KVM: PPC: Book3S HV: Improve handling of debug-trigger HMIs on POWER9 Hypervisor maintenance interrupts (HMIs) are generated by various causes, signalled by bits in the hypervisor maintenance exception register (HMER). In most cases calling OPAL to handle the interrupt is the correct thing to do, but the "debug trigger" HMIs signalled by PPC bit 17 (bit 46) of HMER are used to invoke software workarounds for hardware bugs, and OPAL does not have any code to handle this cause. The debug trigger HMI is used in POWER9 DD2.0 and DD2.1 chips to work around a hardware bug in executing vector load instructions to cache inhibited memory. In POWER9 DD2.2 chips, it is generated when conditions are detected relating to threads being in TM (transactional memory) suspended mode when the core SMT configuration needs to be reconfigured. The kernel currently has code to detect the vector CI load condition, but only when the HMI occurs in the host, not when it occurs in a guest. If a HMI occurs in the guest, it is always passed to OPAL, and then we always re-sync the timebase, because the HMI cause might have been a timebase error, for which OPAL would re-sync the timebase, thus removing the timebase offset which KVM applied for the guest. Since we don't know what OPAL did, we don't know whether to subtract the timebase offset from the timebase, so instead we re-sync the timebase. This adds code to determine explicitly what the cause of a debug trigger HMI will be. This is based on a new device-tree property under the CPU nodes called ibm,hmi-special-triggers, if it is present, or otherwise based on the PVR (processor version register). The handling of debug trigger HMIs is pulled out into a separate function which can be called from the KVM guest exit code. If this function handles and clears the HMI, and no other HMI causes remain, then we skip calling OPAL and we proceed to subtract the guest timebase offset from the timebase. The overall handling for HMIs that occur in the host (i.e. not in a KVM guest) is largely unchanged, except that we now don't set the flag for the vector CI load workaround on DD2.2 processors. This also removes a BUG_ON in the KVM code. BUG_ON is generally not useful in KVM guest entry/exit code since it is difficult to handle the resulting trap gracefully. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-17 17:51:13 +08:00
of_node_put(cpun);
}
preempt_enable();
/* If we found the property, don't look at PVR */
if (prop)
goto out;
pvr = mfspr(SPRN_PVR);
/* Check for POWER9 Nimbus (scale-out) */
if ((PVR_VER(pvr) == PVR_POWER9) && (pvr & 0xe000) == 0) {
/* DD2.2 and later */
if ((pvr & 0xfff) >= 0x202)
hmer_debug_trig_function = DTRIG_SUSPEND_ESCAPE;
/* DD2.0 and DD2.1 - used for vector CI load emulation */
else if ((pvr & 0xfff) >= 0x200)
hmer_debug_trig_function = DTRIG_VECTOR_CI;
}
out:
switch (hmer_debug_trig_function) {
case DTRIG_VECTOR_CI:
pr_debug("HMI debug trigger used for vector CI load\n");
break;
case DTRIG_SUSPEND_ESCAPE:
pr_debug("HMI debug trigger used for TM suspend escape\n");
break;
default:
break;
powerpc/64s: Add workaround for P9 vector CI load issue POWER9 DD2.1 and earlier has an issue where some cache inhibited vector load will return bad data. The workaround is two part, one firmware/microcode part triggers HMI interrupts when hitting such loads, the other part is this patch which then emulates the instructions in Linux. The affected instructions are limited to lxvd2x, lxvw4x, lxvb16x and lxvh8x. When an instruction triggers the HMI, all threads in the core will be sent to the HMI handler, not just the one running the vector load. In general, these spurious HMIs are detected by the emulation code and we just return back to the running process. Unfortunately, if a spurious interrupt occurs on a vector load that's to normal memory we have no way to detect that it's spurious (unless we walk the page tables, which is very expensive). In this case we emulate the load but we need do so using a vector load itself to ensure 128bit atomicity is preserved. Some additional debugfs emulated instruction counters are added also. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Switch CONFIG_PPC_BOOK3S_64 to CONFIG_VSX to unbreak the build] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-15 13:25:48 +08:00
}
KVM: PPC: Book3S HV: Improve handling of debug-trigger HMIs on POWER9 Hypervisor maintenance interrupts (HMIs) are generated by various causes, signalled by bits in the hypervisor maintenance exception register (HMER). In most cases calling OPAL to handle the interrupt is the correct thing to do, but the "debug trigger" HMIs signalled by PPC bit 17 (bit 46) of HMER are used to invoke software workarounds for hardware bugs, and OPAL does not have any code to handle this cause. The debug trigger HMI is used in POWER9 DD2.0 and DD2.1 chips to work around a hardware bug in executing vector load instructions to cache inhibited memory. In POWER9 DD2.2 chips, it is generated when conditions are detected relating to threads being in TM (transactional memory) suspended mode when the core SMT configuration needs to be reconfigured. The kernel currently has code to detect the vector CI load condition, but only when the HMI occurs in the host, not when it occurs in a guest. If a HMI occurs in the guest, it is always passed to OPAL, and then we always re-sync the timebase, because the HMI cause might have been a timebase error, for which OPAL would re-sync the timebase, thus removing the timebase offset which KVM applied for the guest. Since we don't know what OPAL did, we don't know whether to subtract the timebase offset from the timebase, so instead we re-sync the timebase. This adds code to determine explicitly what the cause of a debug trigger HMI will be. This is based on a new device-tree property under the CPU nodes called ibm,hmi-special-triggers, if it is present, or otherwise based on the PVR (processor version register). The handling of debug trigger HMIs is pulled out into a separate function which can be called from the KVM guest exit code. If this function handles and clears the HMI, and no other HMI causes remain, then we skip calling OPAL and we proceed to subtract the guest timebase offset from the timebase. The overall handling for HMIs that occur in the host (i.e. not in a KVM guest) is largely unchanged, except that we now don't set the flag for the vector CI load workaround on DD2.2 processors. This also removes a BUG_ON in the KVM code. BUG_ON is generally not useful in KVM guest entry/exit code since it is difficult to handle the resulting trap gracefully. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-17 17:51:13 +08:00
return 0;
}
__initcall(init_debug_trig_function);
/*
* Handle HMIs that occur as a result of a debug trigger.
* Return values:
* -1 means this is not a HMI cause that we know about
* 0 means no further handling is required
* 1 means further handling is required
*/
long hmi_handle_debugtrig(struct pt_regs *regs)
{
unsigned long hmer = mfspr(SPRN_HMER);
long ret = 0;
/* HMER_DEBUG_TRIG bit is used for various workarounds on P9 */
if (!((hmer & HMER_DEBUG_TRIG)
&& hmer_debug_trig_function != DTRIG_UNKNOWN))
return -1;
hmer &= ~HMER_DEBUG_TRIG;
/* HMER is a write-AND register */
mtspr(SPRN_HMER, ~HMER_DEBUG_TRIG);
switch (hmer_debug_trig_function) {
case DTRIG_VECTOR_CI:
/*
* Now to avoid problems with soft-disable we
* only do the emulation if we are coming from
* host user space
*/
if (regs && user_mode(regs))
ret = local_paca->hmi_p9_special_emu = 1;
break;
default:
break;
}
/*
* See if any other HMI causes remain to be handled
*/
if (hmer & mfspr(SPRN_HMEER))
return -1;
return ret;
}
/*
* Return values:
*/
long hmi_exception_realmode(struct pt_regs *regs)
{
int ret;
__this_cpu_inc(irq_stat.hmi_exceptions);
ret = hmi_handle_debugtrig(regs);
if (ret >= 0)
return ret;
powerpc/64s: Add workaround for P9 vector CI load issue POWER9 DD2.1 and earlier has an issue where some cache inhibited vector load will return bad data. The workaround is two part, one firmware/microcode part triggers HMI interrupts when hitting such loads, the other part is this patch which then emulates the instructions in Linux. The affected instructions are limited to lxvd2x, lxvw4x, lxvb16x and lxvh8x. When an instruction triggers the HMI, all threads in the core will be sent to the HMI handler, not just the one running the vector load. In general, these spurious HMIs are detected by the emulation code and we just return back to the running process. Unfortunately, if a spurious interrupt occurs on a vector load that's to normal memory we have no way to detect that it's spurious (unless we walk the page tables, which is very expensive). In this case we emulate the load but we need do so using a vector load itself to ensure 128bit atomicity is preserved. Some additional debugfs emulated instruction counters are added also. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Switch CONFIG_PPC_BOOK3S_64 to CONFIG_VSX to unbreak the build] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-15 13:25:48 +08:00
powerpc/mce: Move 64-bit machine check code into mce.c We already have mce.c which is built for 64bit and contains other parts of the machine check code, so move these bits in there too. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-08 14:39:24 +08:00
wait_for_subcore_guest_exit();
if (ppc_md.hmi_exception_early)
ppc_md.hmi_exception_early(regs);
wait_for_tb_resync();
powerpc/64s: Add workaround for P9 vector CI load issue POWER9 DD2.1 and earlier has an issue where some cache inhibited vector load will return bad data. The workaround is two part, one firmware/microcode part triggers HMI interrupts when hitting such loads, the other part is this patch which then emulates the instructions in Linux. The affected instructions are limited to lxvd2x, lxvw4x, lxvb16x and lxvh8x. When an instruction triggers the HMI, all threads in the core will be sent to the HMI handler, not just the one running the vector load. In general, these spurious HMIs are detected by the emulation code and we just return back to the running process. Unfortunately, if a spurious interrupt occurs on a vector load that's to normal memory we have no way to detect that it's spurious (unless we walk the page tables, which is very expensive). In this case we emulate the load but we need do so using a vector load itself to ensure 128bit atomicity is preserved. Some additional debugfs emulated instruction counters are added also. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Switch CONFIG_PPC_BOOK3S_64 to CONFIG_VSX to unbreak the build] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-15 13:25:48 +08:00
return 1;
powerpc/mce: Move 64-bit machine check code into mce.c We already have mce.c which is built for 64bit and contains other parts of the machine check code, so move these bits in there too. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-08 14:39:24 +08:00
}