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linux/arch/powerpc/kernel/eeh.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright IBM Corporation 2001, 2005, 2006
* Copyright Dave Engebretsen & Todd Inglett 2001
* Copyright Linas Vepstas 2005, 2006
* Copyright 2001-2012 IBM Corporation.
*
* Please address comments and feedback to Linas Vepstas <linas@austin.ibm.com>
*/
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/iommu.h>
#include <linux/proc_fs.h>
#include <linux/rbtree.h>
#include <linux/reboot.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/export.h>
#include <linux/of.h>
#include <linux/atomic.h>
#include <asm/debugfs.h>
#include <asm/eeh.h>
#include <asm/eeh_event.h>
#include <asm/io.h>
#include <asm/iommu.h>
#include <asm/machdep.h>
#include <asm/ppc-pci.h>
#include <asm/rtas.h>
#include <asm/pte-walk.h>
/** Overview:
* EEH, or "Enhanced Error Handling" is a PCI bridge technology for
* dealing with PCI bus errors that can't be dealt with within the
* usual PCI framework, except by check-stopping the CPU. Systems
* that are designed for high-availability/reliability cannot afford
* to crash due to a "mere" PCI error, thus the need for EEH.
* An EEH-capable bridge operates by converting a detected error
* into a "slot freeze", taking the PCI adapter off-line, making
* the slot behave, from the OS'es point of view, as if the slot
* were "empty": all reads return 0xff's and all writes are silently
* ignored. EEH slot isolation events can be triggered by parity
* errors on the address or data busses (e.g. during posted writes),
* which in turn might be caused by low voltage on the bus, dust,
* vibration, humidity, radioactivity or plain-old failed hardware.
*
* Note, however, that one of the leading causes of EEH slot
* freeze events are buggy device drivers, buggy device microcode,
* or buggy device hardware. This is because any attempt by the
* device to bus-master data to a memory address that is not
* assigned to the device will trigger a slot freeze. (The idea
* is to prevent devices-gone-wild from corrupting system memory).
* Buggy hardware/drivers will have a miserable time co-existing
* with EEH.
*
* Ideally, a PCI device driver, when suspecting that an isolation
* event has occurred (e.g. by reading 0xff's), will then ask EEH
* whether this is the case, and then take appropriate steps to
* reset the PCI slot, the PCI device, and then resume operations.
* However, until that day, the checking is done here, with the
* eeh_check_failure() routine embedded in the MMIO macros. If
* the slot is found to be isolated, an "EEH Event" is synthesized
* and sent out for processing.
*/
/* If a device driver keeps reading an MMIO register in an interrupt
* handler after a slot isolation event, it might be broken.
* This sets the threshold for how many read attempts we allow
* before printing an error message.
*/
#define EEH_MAX_FAILS 2100000
/* Time to wait for a PCI slot to report status, in milliseconds */
#define PCI_BUS_RESET_WAIT_MSEC (5*60*1000)
/*
* EEH probe mode support, which is part of the flags,
* is to support multiple platforms for EEH. Some platforms
* like pSeries do PCI emunation based on device tree.
* However, other platforms like powernv probe PCI devices
* from hardware. The flag is used to distinguish that.
* In addition, struct eeh_ops::probe would be invoked for
* particular OF node or PCI device so that the corresponding
* PE would be created there.
*/
int eeh_subsystem_flags;
EXPORT_SYMBOL(eeh_subsystem_flags);
/*
* EEH allowed maximal frozen times. If one particular PE's
* frozen count in last hour exceeds this limit, the PE will
* be forced to be offline permanently.
*/
u32 eeh_max_freezes = 5;
/*
* Controls whether a recovery event should be scheduled when an
* isolated device is discovered. This is only really useful for
* debugging problems with the EEH core.
*/
bool eeh_debugfs_no_recover;
/* Platform dependent EEH operations */
struct eeh_ops *eeh_ops = NULL;
/* Lock to avoid races due to multiple reports of an error */
DEFINE_RAW_SPINLOCK(confirm_error_lock);
EXPORT_SYMBOL_GPL(confirm_error_lock);
/* Lock to protect passed flags */
static DEFINE_MUTEX(eeh_dev_mutex);
/* Buffer for reporting pci register dumps. Its here in BSS, and
* not dynamically alloced, so that it ends up in RMO where RTAS
* can access it.
*/
#define EEH_PCI_REGS_LOG_LEN 8192
static unsigned char pci_regs_buf[EEH_PCI_REGS_LOG_LEN];
/*
* The struct is used to maintain the EEH global statistic
* information. Besides, the EEH global statistics will be
* exported to user space through procfs
*/
struct eeh_stats {
u64 no_device; /* PCI device not found */
u64 no_dn; /* OF node not found */
u64 no_cfg_addr; /* Config address not found */
u64 ignored_check; /* EEH check skipped */
u64 total_mmio_ffs; /* Total EEH checks */
u64 false_positives; /* Unnecessary EEH checks */
u64 slot_resets; /* PE reset */
};
static struct eeh_stats eeh_stats;
static int __init eeh_setup(char *str)
{
if (!strcmp(str, "off"))
eeh_add_flag(EEH_FORCE_DISABLED);
else if (!strcmp(str, "early_log"))
eeh_add_flag(EEH_EARLY_DUMP_LOG);
return 1;
}
__setup("eeh=", eeh_setup);
void eeh_show_enabled(void)
{
if (eeh_has_flag(EEH_FORCE_DISABLED))
pr_info("EEH: Recovery disabled by kernel parameter.\n");
else if (eeh_has_flag(EEH_ENABLED))
pr_info("EEH: Capable adapter found: recovery enabled.\n");
else
pr_info("EEH: No capable adapters found: recovery disabled.\n");
}
/*
* This routine captures assorted PCI configuration space data
* for the indicated PCI device, and puts them into a buffer
* for RTAS error logging.
*/
static size_t eeh_dump_dev_log(struct eeh_dev *edev, char *buf, size_t len)
{
u32 cfg;
int cap, i;
int n = 0, l = 0;
char buffer[128];
n += scnprintf(buf+n, len-n, "%04x:%02x:%02x.%01x\n",
edev->pe->phb->global_number, edev->bdfn >> 8,
PCI_SLOT(edev->bdfn), PCI_FUNC(edev->bdfn));
pr_warn("EEH: of node=%04x:%02x:%02x.%01x\n",
edev->pe->phb->global_number, edev->bdfn >> 8,
PCI_SLOT(edev->bdfn), PCI_FUNC(edev->bdfn));
eeh_ops->read_config(edev, PCI_VENDOR_ID, 4, &cfg);
n += scnprintf(buf+n, len-n, "dev/vend:%08x\n", cfg);
pr_warn("EEH: PCI device/vendor: %08x\n", cfg);
eeh_ops->read_config(edev, PCI_COMMAND, 4, &cfg);
n += scnprintf(buf+n, len-n, "cmd/stat:%x\n", cfg);
pr_warn("EEH: PCI cmd/status register: %08x\n", cfg);
/* Gather bridge-specific registers */
if (edev->mode & EEH_DEV_BRIDGE) {
eeh_ops->read_config(edev, PCI_SEC_STATUS, 2, &cfg);
n += scnprintf(buf+n, len-n, "sec stat:%x\n", cfg);
pr_warn("EEH: Bridge secondary status: %04x\n", cfg);
eeh_ops->read_config(edev, PCI_BRIDGE_CONTROL, 2, &cfg);
n += scnprintf(buf+n, len-n, "brdg ctl:%x\n", cfg);
pr_warn("EEH: Bridge control: %04x\n", cfg);
}
/* Dump out the PCI-X command and status regs */
cap = edev->pcix_cap;
if (cap) {
eeh_ops->read_config(edev, cap, 4, &cfg);
n += scnprintf(buf+n, len-n, "pcix-cmd:%x\n", cfg);
pr_warn("EEH: PCI-X cmd: %08x\n", cfg);
eeh_ops->read_config(edev, cap+4, 4, &cfg);
n += scnprintf(buf+n, len-n, "pcix-stat:%x\n", cfg);
pr_warn("EEH: PCI-X status: %08x\n", cfg);
}
/* If PCI-E capable, dump PCI-E cap 10 */
cap = edev->pcie_cap;
if (cap) {
n += scnprintf(buf+n, len-n, "pci-e cap10:\n");
pr_warn("EEH: PCI-E capabilities and status follow:\n");
for (i=0; i<=8; i++) {
eeh_ops->read_config(edev, cap+4*i, 4, &cfg);
n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg);
if ((i % 4) == 0) {
if (i != 0)
pr_warn("%s\n", buffer);
l = scnprintf(buffer, sizeof(buffer),
"EEH: PCI-E %02x: %08x ",
4*i, cfg);
} else {
l += scnprintf(buffer+l, sizeof(buffer)-l,
"%08x ", cfg);
}
}
pr_warn("%s\n", buffer);
}
/* If AER capable, dump it */
cap = edev->aer_cap;
if (cap) {
n += scnprintf(buf+n, len-n, "pci-e AER:\n");
pr_warn("EEH: PCI-E AER capability register set follows:\n");
for (i=0; i<=13; i++) {
eeh_ops->read_config(edev, cap+4*i, 4, &cfg);
n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg);
if ((i % 4) == 0) {
if (i != 0)
pr_warn("%s\n", buffer);
l = scnprintf(buffer, sizeof(buffer),
"EEH: PCI-E AER %02x: %08x ",
4*i, cfg);
} else {
l += scnprintf(buffer+l, sizeof(buffer)-l,
"%08x ", cfg);
}
}
pr_warn("%s\n", buffer);
}
return n;
}
static void *eeh_dump_pe_log(struct eeh_pe *pe, void *flag)
{
struct eeh_dev *edev, *tmp;
size_t *plen = flag;
eeh_pe_for_each_dev(pe, edev, tmp)
*plen += eeh_dump_dev_log(edev, pci_regs_buf + *plen,
EEH_PCI_REGS_LOG_LEN - *plen);
return NULL;
}
/**
* eeh_slot_error_detail - Generate combined log including driver log and error log
* @pe: EEH PE
* @severity: temporary or permanent error log
*
* This routine should be called to generate the combined log, which
* is comprised of driver log and error log. The driver log is figured
* out from the config space of the corresponding PCI device, while
* the error log is fetched through platform dependent function call.
*/
void eeh_slot_error_detail(struct eeh_pe *pe, int severity)
{
size_t loglen = 0;
/*
* When the PHB is fenced or dead, it's pointless to collect
* the data from PCI config space because it should return
* 0xFF's. For ER, we still retrieve the data from the PCI
* config space.
*
* For pHyp, we have to enable IO for log retrieval. Otherwise,
* 0xFF's is always returned from PCI config space.
*
* When the @severity is EEH_LOG_PERM, the PE is going to be
* removed. Prior to that, the drivers for devices included in
* the PE will be closed. The drivers rely on working IO path
* to bring the devices to quiet state. Otherwise, PCI traffic
* from those devices after they are removed is like to cause
* another unexpected EEH error.
*/
if (!(pe->type & EEH_PE_PHB)) {
if (eeh_has_flag(EEH_ENABLE_IO_FOR_LOG) ||
severity == EEH_LOG_PERM)
eeh_pci_enable(pe, EEH_OPT_THAW_MMIO);
/*
* The config space of some PCI devices can't be accessed
* when their PEs are in frozen state. Otherwise, fenced
* PHB might be seen. Those PEs are identified with flag
* EEH_PE_CFG_RESTRICTED, indicating EEH_PE_CFG_BLOCKED
* is set automatically when the PE is put to EEH_PE_ISOLATED.
*
* Restoring BARs possibly triggers PCI config access in
* (OPAL) firmware and then causes fenced PHB. If the
* PCI config is blocked with flag EEH_PE_CFG_BLOCKED, it's
* pointless to restore BARs and dump config space.
*/
eeh_ops->configure_bridge(pe);
if (!(pe->state & EEH_PE_CFG_BLOCKED)) {
eeh_pe_restore_bars(pe);
pci_regs_buf[0] = 0;
eeh_pe_traverse(pe, eeh_dump_pe_log, &loglen);
}
}
eeh_ops->get_log(pe, severity, pci_regs_buf, loglen);
}
/**
* eeh_token_to_phys - Convert EEH address token to phys address
* @token: I/O token, should be address in the form 0xA....
*
* This routine should be called to convert virtual I/O address
* to physical one.
*/
static inline unsigned long eeh_token_to_phys(unsigned long token)
{
pte_t *ptep;
unsigned long pa;
int hugepage_shift;
/*
* We won't find hugepages here(this is iomem). Hence we are not
* worried about _PAGE_SPLITTING/collapse. Also we will not hit
* page table free, because of init_mm.
*/
ptep = find_init_mm_pte(token, &hugepage_shift);
if (!ptep)
return token;
pa = pte_pfn(*ptep);
/* On radix we can do hugepage mappings for io, so handle that */
if (!hugepage_shift)
hugepage_shift = PAGE_SHIFT;
pa <<= PAGE_SHIFT;
pa |= token & ((1ul << hugepage_shift) - 1);
return pa;
}
/*
* On PowerNV platform, we might already have fenced PHB there.
* For that case, it's meaningless to recover frozen PE. Intead,
* We have to handle fenced PHB firstly.
*/
static int eeh_phb_check_failure(struct eeh_pe *pe)
{
struct eeh_pe *phb_pe;
unsigned long flags;
int ret;
if (!eeh_has_flag(EEH_PROBE_MODE_DEV))
return -EPERM;
/* Find the PHB PE */
phb_pe = eeh_phb_pe_get(pe->phb);
if (!phb_pe) {
pr_warn("%s Can't find PE for PHB#%x\n",
__func__, pe->phb->global_number);
return -EEXIST;
}
/* If the PHB has been in problematic state */
eeh_serialize_lock(&flags);
if (phb_pe->state & EEH_PE_ISOLATED) {
ret = 0;
goto out;
}
/* Check PHB state */
ret = eeh_ops->get_state(phb_pe, NULL);
if ((ret < 0) ||
(ret == EEH_STATE_NOT_SUPPORT) || eeh_state_active(ret)) {
ret = 0;
goto out;
}
/* Isolate the PHB and send event */
eeh_pe_mark_isolated(phb_pe);
eeh_serialize_unlock(flags);
pr_debug("EEH: PHB#%x failure detected, location: %s\n",
phb_pe->phb->global_number, eeh_pe_loc_get(phb_pe));
eeh_send_failure_event(phb_pe);
return 1;
out:
eeh_serialize_unlock(flags);
return ret;
}
/**
* eeh_dev_check_failure - Check if all 1's data is due to EEH slot freeze
* @edev: eeh device
*
* Check for an EEH failure for the given device node. Call this
* routine if the result of a read was all 0xff's and you want to
* find out if this is due to an EEH slot freeze. This routine
* will query firmware for the EEH status.
*
* Returns 0 if there has not been an EEH error; otherwise returns
* a non-zero value and queues up a slot isolation event notification.
*
* It is safe to call this routine in an interrupt context.
*/
int eeh_dev_check_failure(struct eeh_dev *edev)
{
int ret;
unsigned long flags;
struct device_node *dn;
struct pci_dev *dev;
struct eeh_pe *pe, *parent_pe;
int rc = 0;
const char *location = NULL;
eeh_stats.total_mmio_ffs++;
if (!eeh_enabled())
return 0;
if (!edev) {
eeh_stats.no_dn++;
return 0;
}
dev = eeh_dev_to_pci_dev(edev);
pe = eeh_dev_to_pe(edev);
/* Access to IO BARs might get this far and still not want checking. */
if (!pe) {
eeh_stats.ignored_check++;
eeh_edev_dbg(edev, "Ignored check\n");
return 0;
}
/*
* On PowerNV platform, we might already have fenced PHB
* there and we need take care of that firstly.
*/
ret = eeh_phb_check_failure(pe);
if (ret > 0)
return ret;
/*
* If the PE isn't owned by us, we shouldn't check the
* state. Instead, let the owner handle it if the PE has
* been frozen.
*/
if (eeh_pe_passed(pe))
return 0;
/* If we already have a pending isolation event for this
* slot, we know it's bad already, we don't need to check.
* Do this checking under a lock; as multiple PCI devices
* in one slot might report errors simultaneously, and we
* only want one error recovery routine running.
*/
eeh_serialize_lock(&flags);
rc = 1;
if (pe->state & EEH_PE_ISOLATED) {
pe->check_count++;
if (pe->check_count == EEH_MAX_FAILS) {
dn = pci_device_to_OF_node(dev);
if (dn)
location = of_get_property(dn, "ibm,loc-code",
NULL);
eeh_edev_err(edev, "%d reads ignored for recovering device at location=%s driver=%s\n",
pe->check_count,
location ? location : "unknown",
eeh_driver_name(dev));
eeh_edev_err(edev, "Might be infinite loop in %s driver\n",
eeh_driver_name(dev));
dump_stack();
}
goto dn_unlock;
}
/*
* Now test for an EEH failure. This is VERY expensive.
* Note that the eeh_config_addr may be a parent device
* in the case of a device behind a bridge, or it may be
* function zero of a multi-function device.
* In any case they must share a common PHB.
*/
ret = eeh_ops->get_state(pe, NULL);
/* Note that config-io to empty slots may fail;
* they are empty when they don't have children.
* We will punt with the following conditions: Failure to get
* PE's state, EEH not support and Permanently unavailable
* state, PE is in good state.
*/
if ((ret < 0) ||
(ret == EEH_STATE_NOT_SUPPORT) || eeh_state_active(ret)) {
eeh_stats.false_positives++;
pe->false_positives++;
rc = 0;
goto dn_unlock;
}
/*
* It should be corner case that the parent PE has been
* put into frozen state as well. We should take care
* that at first.
*/
parent_pe = pe->parent;
while (parent_pe) {
/* Hit the ceiling ? */
if (parent_pe->type & EEH_PE_PHB)
break;
/* Frozen parent PE ? */
ret = eeh_ops->get_state(parent_pe, NULL);
if (ret > 0 && !eeh_state_active(ret)) {
pe = parent_pe;
pr_err("EEH: Failure of PHB#%x-PE#%x will be handled at parent PHB#%x-PE#%x.\n",
pe->phb->global_number, pe->addr,
pe->phb->global_number, parent_pe->addr);
}
/* Next parent level */
parent_pe = parent_pe->parent;
}
eeh_stats.slot_resets++;
/* Avoid repeated reports of this failure, including problems
* with other functions on this device, and functions under
* bridges.
*/
eeh_pe_mark_isolated(pe);
eeh_serialize_unlock(flags);
/* Most EEH events are due to device driver bugs. Having
* a stack trace will help the device-driver authors figure
* out what happened. So print that out.
*/
pr_debug("EEH: %s: Frozen PHB#%x-PE#%x detected\n",
__func__, pe->phb->global_number, pe->addr);
eeh_send_failure_event(pe);
return 1;
dn_unlock:
eeh_serialize_unlock(flags);
return rc;
}
EXPORT_SYMBOL_GPL(eeh_dev_check_failure);
/**
* eeh_check_failure - Check if all 1's data is due to EEH slot freeze
* @token: I/O address
*
* Check for an EEH failure at the given I/O address. Call this
* routine if the result of a read was all 0xff's and you want to
* find out if this is due to an EEH slot freeze event. This routine
* will query firmware for the EEH status.
*
* Note this routine is safe to call in an interrupt context.
*/
int eeh_check_failure(const volatile void __iomem *token)
{
unsigned long addr;
struct eeh_dev *edev;
/* Finding the phys addr + pci device; this is pretty quick. */
addr = eeh_token_to_phys((unsigned long __force) token);
edev = eeh_addr_cache_get_dev(addr);
if (!edev) {
eeh_stats.no_device++;
return 0;
}
return eeh_dev_check_failure(edev);
}
EXPORT_SYMBOL(eeh_check_failure);
/**
* eeh_pci_enable - Enable MMIO or DMA transfers for this slot
* @pe: EEH PE
*
* This routine should be called to reenable frozen MMIO or DMA
* so that it would work correctly again. It's useful while doing
* recovery or log collection on the indicated device.
*/
int eeh_pci_enable(struct eeh_pe *pe, int function)
{
int active_flag, rc;
/*
* pHyp doesn't allow to enable IO or DMA on unfrozen PE.
* Also, it's pointless to enable them on unfrozen PE. So
* we have to check before enabling IO or DMA.
*/
switch (function) {
case EEH_OPT_THAW_MMIO:
active_flag = EEH_STATE_MMIO_ACTIVE | EEH_STATE_MMIO_ENABLED;
break;
case EEH_OPT_THAW_DMA:
active_flag = EEH_STATE_DMA_ACTIVE;
break;
case EEH_OPT_DISABLE:
case EEH_OPT_ENABLE:
case EEH_OPT_FREEZE_PE:
active_flag = 0;
break;
default:
pr_warn("%s: Invalid function %d\n",
__func__, function);
return -EINVAL;
}
/*
* Check if IO or DMA has been enabled before
* enabling them.
*/
if (active_flag) {
rc = eeh_ops->get_state(pe, NULL);
if (rc < 0)
return rc;
/* Needn't enable it at all */
if (rc == EEH_STATE_NOT_SUPPORT)
return 0;
/* It's already enabled */
if (rc & active_flag)
return 0;
}
/* Issue the request */
rc = eeh_ops->set_option(pe, function);
if (rc)
pr_warn("%s: Unexpected state change %d on "
"PHB#%x-PE#%x, err=%d\n",
__func__, function, pe->phb->global_number,
pe->addr, rc);
/* Check if the request is finished successfully */
if (active_flag) {
rc = eeh_wait_state(pe, PCI_BUS_RESET_WAIT_MSEC);
if (rc < 0)
return rc;
if (rc & active_flag)
return 0;
return -EIO;
}
return rc;
}
static void eeh_disable_and_save_dev_state(struct eeh_dev *edev,
void *userdata)
{
struct pci_dev *pdev = eeh_dev_to_pci_dev(edev);
struct pci_dev *dev = userdata;
/*
* The caller should have disabled and saved the
* state for the specified device
*/
if (!pdev || pdev == dev)
return;
/* Ensure we have D0 power state */
pci_set_power_state(pdev, PCI_D0);
/* Save device state */
pci_save_state(pdev);
/*
* Disable device to avoid any DMA traffic and
* interrupt from the device
*/
pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
}
static void eeh_restore_dev_state(struct eeh_dev *edev, void *userdata)
{
struct pci_dev *pdev = eeh_dev_to_pci_dev(edev);
struct pci_dev *dev = userdata;
if (!pdev)
return;
/* Apply customization from firmware */
if (eeh_ops->restore_config)
eeh_ops->restore_config(edev);
/* The caller should restore state for the specified device */
if (pdev != dev)
pci_restore_state(pdev);
}
/**
* pcibios_set_pcie_reset_state - Set PCI-E reset state
* @dev: pci device struct
* @state: reset state to enter
*
* Return value:
* 0 if success
*/
int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
{
struct eeh_dev *edev = pci_dev_to_eeh_dev(dev);
struct eeh_pe *pe = eeh_dev_to_pe(edev);
if (!pe) {
pr_err("%s: No PE found on PCI device %s\n",
__func__, pci_name(dev));
return -EINVAL;
}
switch (state) {
case pcie_deassert_reset:
eeh_ops->reset(pe, EEH_RESET_DEACTIVATE);
eeh_unfreeze_pe(pe);
if (!(pe->type & EEH_PE_VF))
eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, true);
eeh_pe_dev_traverse(pe, eeh_restore_dev_state, dev);
eeh_pe_state_clear(pe, EEH_PE_ISOLATED, true);
break;
case pcie_hot_reset:
eeh_pe_mark_isolated(pe);
eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, true);
eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE);
eeh_pe_dev_traverse(pe, eeh_disable_and_save_dev_state, dev);
if (!(pe->type & EEH_PE_VF))
eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED);
eeh_ops->reset(pe, EEH_RESET_HOT);
break;
case pcie_warm_reset:
eeh_pe_mark_isolated(pe);
eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, true);
eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE);
eeh_pe_dev_traverse(pe, eeh_disable_and_save_dev_state, dev);
if (!(pe->type & EEH_PE_VF))
eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED);
eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL);
break;
default:
eeh_pe_state_clear(pe, EEH_PE_ISOLATED | EEH_PE_CFG_BLOCKED, true);
return -EINVAL;
}
return 0;
}
/**
* eeh_set_pe_freset - Check the required reset for the indicated device
* @data: EEH device
* @flag: return value
*
* Each device might have its preferred reset type: fundamental or
* hot reset. The routine is used to collected the information for
* the indicated device and its children so that the bunch of the
* devices could be reset properly.
*/
static void eeh_set_dev_freset(struct eeh_dev *edev, void *flag)
{
struct pci_dev *dev;
unsigned int *freset = (unsigned int *)flag;
dev = eeh_dev_to_pci_dev(edev);
if (dev)
*freset |= dev->needs_freset;
}
static void eeh_pe_refreeze_passed(struct eeh_pe *root)
{
struct eeh_pe *pe;
int state;
eeh_for_each_pe(root, pe) {
if (eeh_pe_passed(pe)) {
state = eeh_ops->get_state(pe, NULL);
if (state &
(EEH_STATE_MMIO_ACTIVE | EEH_STATE_MMIO_ENABLED)) {
pr_info("EEH: Passed-through PE PHB#%x-PE#%x was thawed by reset, re-freezing for safety.\n",
pe->phb->global_number, pe->addr);
eeh_pe_set_option(pe, EEH_OPT_FREEZE_PE);
}
}
}
}
/**
* eeh_pe_reset_full - Complete a full reset process on the indicated PE
* @pe: EEH PE
*
* This function executes a full reset procedure on a PE, including setting
* the appropriate flags, performing a fundamental or hot reset, and then
* deactivating the reset status. It is designed to be used within the EEH
* subsystem, as opposed to eeh_pe_reset which is exported to drivers and
* only performs a single operation at a time.
*
* This function will attempt to reset a PE three times before failing.
*/
int eeh_pe_reset_full(struct eeh_pe *pe, bool include_passed)
{
int reset_state = (EEH_PE_RESET | EEH_PE_CFG_BLOCKED);
int type = EEH_RESET_HOT;
unsigned int freset = 0;
int i, state = 0, ret;
/*
* Determine the type of reset to perform - hot or fundamental.
* Hot reset is the default operation, unless any device under the
* PE requires a fundamental reset.
*/
eeh_pe_dev_traverse(pe, eeh_set_dev_freset, &freset);
if (freset)
type = EEH_RESET_FUNDAMENTAL;
/* Mark the PE as in reset state and block config space accesses */
eeh_pe_state_mark(pe, reset_state);
/* Make three attempts at resetting the bus */
for (i = 0; i < 3; i++) {
ret = eeh_pe_reset(pe, type, include_passed);
if (!ret)
ret = eeh_pe_reset(pe, EEH_RESET_DEACTIVATE,
include_passed);
if (ret) {
ret = -EIO;
pr_warn("EEH: Failure %d resetting PHB#%x-PE#%x (attempt %d)\n\n",
state, pe->phb->global_number, pe->addr, i + 1);
continue;
}
if (i)
pr_warn("EEH: PHB#%x-PE#%x: Successful reset (attempt %d)\n",
pe->phb->global_number, pe->addr, i + 1);
/* Wait until the PE is in a functioning state */
state = eeh_wait_state(pe, PCI_BUS_RESET_WAIT_MSEC);
if (state < 0) {
pr_warn("EEH: Unrecoverable slot failure on PHB#%x-PE#%x",
pe->phb->global_number, pe->addr);
ret = -ENOTRECOVERABLE;
break;
}
if (eeh_state_active(state))
break;
else
pr_warn("EEH: PHB#%x-PE#%x: Slot inactive after reset: 0x%x (attempt %d)\n",
pe->phb->global_number, pe->addr, state, i + 1);
}
/* Resetting the PE may have unfrozen child PEs. If those PEs have been
* (potentially) passed through to a guest, re-freeze them:
*/
if (!include_passed)
eeh_pe_refreeze_passed(pe);
eeh_pe_state_clear(pe, reset_state, true);
return ret;
}
/**
* eeh_save_bars - Save device bars
* @edev: PCI device associated EEH device
*
* Save the values of the device bars. Unlike the restore
* routine, this routine is *not* recursive. This is because
* PCI devices are added individually; but, for the restore,
* an entire slot is reset at a time.
*/
void eeh_save_bars(struct eeh_dev *edev)
{
int i;
if (!edev)
return;
for (i = 0; i < 16; i++)
eeh_ops->read_config(edev, i * 4, 4, &edev->config_space[i]);
/*
* For PCI bridges including root port, we need enable bus
* master explicitly. Otherwise, it can't fetch IODA table
* entries correctly. So we cache the bit in advance so that
* we can restore it after reset, either PHB range or PE range.
*/
if (edev->mode & EEH_DEV_BRIDGE)
edev->config_space[1] |= PCI_COMMAND_MASTER;
}
static int eeh_reboot_notifier(struct notifier_block *nb,
unsigned long action, void *unused)
{
eeh_clear_flag(EEH_ENABLED);
return NOTIFY_DONE;
}
static struct notifier_block eeh_reboot_nb = {
.notifier_call = eeh_reboot_notifier,
};
static int eeh_device_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
struct device *dev = data;
switch (action) {
/*
* Note: It's not possible to perform EEH device addition (i.e.
* {pseries,pnv}_pcibios_bus_add_device()) here because it depends on
* the device's resources, which have not yet been set up.
*/
case BUS_NOTIFY_DEL_DEVICE:
eeh_remove_device(to_pci_dev(dev));
break;
default:
break;
}
return NOTIFY_DONE;
}
static struct notifier_block eeh_device_nb = {
.notifier_call = eeh_device_notifier,
};
/**
* eeh_init - System wide EEH initialization
*
* It's the platform's job to call this from an arch_initcall().
*/
int eeh_init(struct eeh_ops *ops)
{
struct pci_controller *hose, *tmp;
int ret = 0;
/* the platform should only initialise EEH once */
if (WARN_ON(eeh_ops))
return -EEXIST;
if (WARN_ON(!ops))
return -ENOENT;
eeh_ops = ops;
/* Register reboot notifier */
ret = register_reboot_notifier(&eeh_reboot_nb);
if (ret) {
pr_warn("%s: Failed to register reboot notifier (%d)\n",
__func__, ret);
return ret;
}
ret = bus_register_notifier(&pci_bus_type, &eeh_device_nb);
if (ret) {
pr_warn("%s: Failed to register bus notifier (%d)\n",
__func__, ret);
return ret;
}
/* Initialize PHB PEs */
list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
eeh_phb_pe_create(hose);
eeh_addr_cache_init();
/* Initialize EEH event */
return eeh_event_init();
}
/**
* eeh_probe_device() - Perform EEH initialization for the indicated pci device
* @dev: pci device for which to set up EEH
*
* This routine must be used to complete EEH initialization for PCI
* devices that were added after system boot (e.g. hotplug, dlpar).
*/
void eeh_probe_device(struct pci_dev *dev)
{
struct eeh_dev *edev;
pr_debug("EEH: Adding device %s\n", pci_name(dev));
/*
* pci_dev_to_eeh_dev() can only work if eeh_probe_dev() was
* already called for this device.
*/
if (WARN_ON_ONCE(pci_dev_to_eeh_dev(dev))) {
pci_dbg(dev, "Already bound to an eeh_dev!\n");
return;
}
edev = eeh_ops->probe(dev);
if (!edev) {
pr_debug("EEH: Adding device failed\n");
return;
}
/*
* FIXME: We rely on pcibios_release_device() to remove the
* existing EEH state. The release function is only called if
* the pci_dev's refcount drops to zero so if something is
* keeping a ref to a device (e.g. a filesystem) we need to
* remove the old EEH state.
*
* FIXME: HEY MA, LOOK AT ME, NO LOCKING!
*/
if (edev->pdev && edev->pdev != dev) {
eeh_pe_tree_remove(edev);
eeh_addr_cache_rmv_dev(edev->pdev);
eeh_sysfs_remove_device(edev->pdev);
/*
* We definitely should have the PCI device removed
* though it wasn't correctly. So we needn't call
* into error handler afterwards.
*/
edev->mode |= EEH_DEV_NO_HANDLER;
}
/* bind the pdev and the edev together */
edev->pdev = dev;
dev->dev.archdata.edev = edev;
eeh_addr_cache_insert_dev(dev);
eeh_sysfs_add_device(dev);
}
/**
* eeh_remove_device - Undo EEH setup for the indicated pci device
* @dev: pci device to be removed
*
* This routine should be called when a device is removed from
* a running system (e.g. by hotplug or dlpar). It unregisters
* the PCI device from the EEH subsystem. I/O errors affecting
* this device will no longer be detected after this call; thus,
* i/o errors affecting this slot may leave this device unusable.
*/
void eeh_remove_device(struct pci_dev *dev)
{
struct eeh_dev *edev;
if (!dev || !eeh_enabled())
return;
edev = pci_dev_to_eeh_dev(dev);
/* Unregister the device with the EEH/PCI address search system */
dev_dbg(&dev->dev, "EEH: Removing device\n");
if (!edev || !edev->pdev || !edev->pe) {
dev_dbg(&dev->dev, "EEH: Device not referenced!\n");
return;
}
/*
* During the hotplug for EEH error recovery, we need the EEH
* device attached to the parent PE in order for BAR restore
* a bit later. So we keep it for BAR restore and remove it
* from the parent PE during the BAR resotre.
*/
edev->pdev = NULL;
/*
* eeh_sysfs_remove_device() uses pci_dev_to_eeh_dev() so we need to
* remove the sysfs files before clearing dev.archdata.edev
*/
if (edev->mode & EEH_DEV_SYSFS)
eeh_sysfs_remove_device(dev);
/*
* We're removing from the PCI subsystem, that means
* the PCI device driver can't support EEH or not
* well. So we rely on hotplug completely to do recovery
* for the specific PCI device.
*/
edev->mode |= EEH_DEV_NO_HANDLER;
eeh_addr_cache_rmv_dev(dev);
/*
* The flag "in_error" is used to trace EEH devices for VFs
* in error state or not. It's set in eeh_report_error(). If
* it's not set, eeh_report_{reset,resume}() won't be called
* for the VF EEH device.
*/
edev->in_error = false;
dev->dev.archdata.edev = NULL;
if (!(edev->pe->state & EEH_PE_KEEP))
eeh_pe_tree_remove(edev);
else
edev->mode |= EEH_DEV_DISCONNECTED;
}
int eeh_unfreeze_pe(struct eeh_pe *pe)
{
int ret;
ret = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO);
if (ret) {
pr_warn("%s: Failure %d enabling IO on PHB#%x-PE#%x\n",
__func__, ret, pe->phb->global_number, pe->addr);
return ret;
}
ret = eeh_pci_enable(pe, EEH_OPT_THAW_DMA);
if (ret) {
pr_warn("%s: Failure %d enabling DMA on PHB#%x-PE#%x\n",
__func__, ret, pe->phb->global_number, pe->addr);
return ret;
}
return ret;
}
static struct pci_device_id eeh_reset_ids[] = {
{ PCI_DEVICE(0x19a2, 0x0710) }, /* Emulex, BE */
{ PCI_DEVICE(0x10df, 0xe220) }, /* Emulex, Lancer */
{ PCI_DEVICE(0x14e4, 0x1657) }, /* Broadcom BCM5719 */
{ 0 }
};
static int eeh_pe_change_owner(struct eeh_pe *pe)
{
struct eeh_dev *edev, *tmp;
struct pci_dev *pdev;
struct pci_device_id *id;
int ret;
/* Check PE state */
ret = eeh_ops->get_state(pe, NULL);
if (ret < 0 || ret == EEH_STATE_NOT_SUPPORT)
return 0;
/* Unfrozen PE, nothing to do */
if (eeh_state_active(ret))
return 0;
/* Frozen PE, check if it needs PE level reset */
eeh_pe_for_each_dev(pe, edev, tmp) {
pdev = eeh_dev_to_pci_dev(edev);
if (!pdev)
continue;
for (id = &eeh_reset_ids[0]; id->vendor != 0; id++) {
if (id->vendor != PCI_ANY_ID &&
id->vendor != pdev->vendor)
continue;
if (id->device != PCI_ANY_ID &&
id->device != pdev->device)
continue;
if (id->subvendor != PCI_ANY_ID &&
id->subvendor != pdev->subsystem_vendor)
continue;
if (id->subdevice != PCI_ANY_ID &&
id->subdevice != pdev->subsystem_device)
continue;
return eeh_pe_reset_and_recover(pe);
}
}
ret = eeh_unfreeze_pe(pe);
if (!ret)
eeh_pe_state_clear(pe, EEH_PE_ISOLATED, true);
return ret;
}
/**
* eeh_dev_open - Increase count of pass through devices for PE
* @pdev: PCI device
*
* Increase count of passed through devices for the indicated
* PE. In the result, the EEH errors detected on the PE won't be
* reported. The PE owner will be responsible for detection
* and recovery.
*/
int eeh_dev_open(struct pci_dev *pdev)
{
struct eeh_dev *edev;
int ret = -ENODEV;
mutex_lock(&eeh_dev_mutex);
/* No PCI device ? */
if (!pdev)
goto out;
/* No EEH device or PE ? */
edev = pci_dev_to_eeh_dev(pdev);
if (!edev || !edev->pe)
goto out;
/*
* The PE might have been put into frozen state, but we
* didn't detect that yet. The passed through PCI devices
* in frozen PE won't work properly. Clear the frozen state
* in advance.
*/
ret = eeh_pe_change_owner(edev->pe);
if (ret)
goto out;
/* Increase PE's pass through count */
atomic_inc(&edev->pe->pass_dev_cnt);
mutex_unlock(&eeh_dev_mutex);
return 0;
out:
mutex_unlock(&eeh_dev_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(eeh_dev_open);
/**
* eeh_dev_release - Decrease count of pass through devices for PE
* @pdev: PCI device
*
* Decrease count of pass through devices for the indicated PE. If
* there is no passed through device in PE, the EEH errors detected
* on the PE will be reported and handled as usual.
*/
void eeh_dev_release(struct pci_dev *pdev)
{
struct eeh_dev *edev;
mutex_lock(&eeh_dev_mutex);
/* No PCI device ? */
if (!pdev)
goto out;
/* No EEH device ? */
edev = pci_dev_to_eeh_dev(pdev);
if (!edev || !edev->pe || !eeh_pe_passed(edev->pe))
goto out;
/* Decrease PE's pass through count */
WARN_ON(atomic_dec_if_positive(&edev->pe->pass_dev_cnt) < 0);
eeh_pe_change_owner(edev->pe);
out:
mutex_unlock(&eeh_dev_mutex);
}
EXPORT_SYMBOL(eeh_dev_release);
#ifdef CONFIG_IOMMU_API
static int dev_has_iommu_table(struct device *dev, void *data)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct pci_dev **ppdev = data;
if (!dev)
return 0;
if (device_iommu_mapped(dev)) {
*ppdev = pdev;
return 1;
}
return 0;
}
/**
* eeh_iommu_group_to_pe - Convert IOMMU group to EEH PE
* @group: IOMMU group
*
* The routine is called to convert IOMMU group to EEH PE.
*/
struct eeh_pe *eeh_iommu_group_to_pe(struct iommu_group *group)
{
struct pci_dev *pdev = NULL;
struct eeh_dev *edev;
int ret;
/* No IOMMU group ? */
if (!group)
return NULL;
ret = iommu_group_for_each_dev(group, &pdev, dev_has_iommu_table);
if (!ret || !pdev)
return NULL;
/* No EEH device or PE ? */
edev = pci_dev_to_eeh_dev(pdev);
if (!edev || !edev->pe)
return NULL;
return edev->pe;
}
EXPORT_SYMBOL_GPL(eeh_iommu_group_to_pe);
#endif /* CONFIG_IOMMU_API */
/**
* eeh_pe_set_option - Set options for the indicated PE
* @pe: EEH PE
* @option: requested option
*
* The routine is called to enable or disable EEH functionality
* on the indicated PE, to enable IO or DMA for the frozen PE.
*/
int eeh_pe_set_option(struct eeh_pe *pe, int option)
{
int ret = 0;
/* Invalid PE ? */
if (!pe)
return -ENODEV;
/*
* EEH functionality could possibly be disabled, just
* return error for the case. And the EEH functinality
* isn't expected to be disabled on one specific PE.
*/
switch (option) {
case EEH_OPT_ENABLE:
if (eeh_enabled()) {
ret = eeh_pe_change_owner(pe);
break;
}
ret = -EIO;
break;
case EEH_OPT_DISABLE:
break;
case EEH_OPT_THAW_MMIO:
case EEH_OPT_THAW_DMA:
case EEH_OPT_FREEZE_PE:
if (!eeh_ops || !eeh_ops->set_option) {
ret = -ENOENT;
break;
}
ret = eeh_pci_enable(pe, option);
break;
default:
pr_debug("%s: Option %d out of range (%d, %d)\n",
__func__, option, EEH_OPT_DISABLE, EEH_OPT_THAW_DMA);
ret = -EINVAL;
}
return ret;
}
EXPORT_SYMBOL_GPL(eeh_pe_set_option);
/**
* eeh_pe_get_state - Retrieve PE's state
* @pe: EEH PE
*
* Retrieve the PE's state, which includes 3 aspects: enabled
* DMA, enabled IO and asserted reset.
*/
int eeh_pe_get_state(struct eeh_pe *pe)
{
int result, ret = 0;
bool rst_active, dma_en, mmio_en;
/* Existing PE ? */
if (!pe)
return -ENODEV;
if (!eeh_ops || !eeh_ops->get_state)
return -ENOENT;
/*
* If the parent PE is owned by the host kernel and is undergoing
* error recovery, we should return the PE state as temporarily
* unavailable so that the error recovery on the guest is suspended
* until the recovery completes on the host.
*/
if (pe->parent &&
!(pe->state & EEH_PE_REMOVED) &&
(pe->parent->state & (EEH_PE_ISOLATED | EEH_PE_RECOVERING)))
return EEH_PE_STATE_UNAVAIL;
result = eeh_ops->get_state(pe, NULL);
rst_active = !!(result & EEH_STATE_RESET_ACTIVE);
dma_en = !!(result & EEH_STATE_DMA_ENABLED);
mmio_en = !!(result & EEH_STATE_MMIO_ENABLED);
if (rst_active)
ret = EEH_PE_STATE_RESET;
else if (dma_en && mmio_en)
ret = EEH_PE_STATE_NORMAL;
else if (!dma_en && !mmio_en)
ret = EEH_PE_STATE_STOPPED_IO_DMA;
else if (!dma_en && mmio_en)
ret = EEH_PE_STATE_STOPPED_DMA;
else
ret = EEH_PE_STATE_UNAVAIL;
return ret;
}
EXPORT_SYMBOL_GPL(eeh_pe_get_state);
static int eeh_pe_reenable_devices(struct eeh_pe *pe, bool include_passed)
{
struct eeh_dev *edev, *tmp;
struct pci_dev *pdev;
int ret = 0;
eeh_pe_restore_bars(pe);
/*
* Reenable PCI devices as the devices passed
* through are always enabled before the reset.
*/
eeh_pe_for_each_dev(pe, edev, tmp) {
pdev = eeh_dev_to_pci_dev(edev);
if (!pdev)
continue;
ret = pci_reenable_device(pdev);
if (ret) {
pr_warn("%s: Failure %d reenabling %s\n",
__func__, ret, pci_name(pdev));
return ret;
}
}
/* The PE is still in frozen state */
if (include_passed || !eeh_pe_passed(pe)) {
ret = eeh_unfreeze_pe(pe);
} else
pr_info("EEH: Note: Leaving passthrough PHB#%x-PE#%x frozen.\n",
pe->phb->global_number, pe->addr);
if (!ret)
eeh_pe_state_clear(pe, EEH_PE_ISOLATED, include_passed);
return ret;
}
/**
* eeh_pe_reset - Issue PE reset according to specified type
* @pe: EEH PE
* @option: reset type
*
* The routine is called to reset the specified PE with the
* indicated type, either fundamental reset or hot reset.
* PE reset is the most important part for error recovery.
*/
int eeh_pe_reset(struct eeh_pe *pe, int option, bool include_passed)
{
int ret = 0;
/* Invalid PE ? */
if (!pe)
return -ENODEV;
if (!eeh_ops || !eeh_ops->set_option || !eeh_ops->reset)
return -ENOENT;
switch (option) {
case EEH_RESET_DEACTIVATE:
ret = eeh_ops->reset(pe, option);
eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, include_passed);
if (ret)
break;
ret = eeh_pe_reenable_devices(pe, include_passed);
break;
case EEH_RESET_HOT:
case EEH_RESET_FUNDAMENTAL:
/*
* Proactively freeze the PE to drop all MMIO access
* during reset, which should be banned as it's always
* cause recursive EEH error.
*/
eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE);
eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED);
ret = eeh_ops->reset(pe, option);
break;
default:
pr_debug("%s: Unsupported option %d\n",
__func__, option);
ret = -EINVAL;
}
return ret;
}
EXPORT_SYMBOL_GPL(eeh_pe_reset);
/**
* eeh_pe_configure - Configure PCI bridges after PE reset
* @pe: EEH PE
*
* The routine is called to restore the PCI config space for
* those PCI devices, especially PCI bridges affected by PE
* reset issued previously.
*/
int eeh_pe_configure(struct eeh_pe *pe)
{
int ret = 0;
/* Invalid PE ? */
if (!pe)
return -ENODEV;
return ret;
}
EXPORT_SYMBOL_GPL(eeh_pe_configure);
/**
* eeh_pe_inject_err - Injecting the specified PCI error to the indicated PE
* @pe: the indicated PE
* @type: error type
* @function: error function
* @addr: address
* @mask: address mask
*
* The routine is called to inject the specified PCI error, which
* is determined by @type and @function, to the indicated PE for
* testing purpose.
*/
int eeh_pe_inject_err(struct eeh_pe *pe, int type, int func,
unsigned long addr, unsigned long mask)
{
/* Invalid PE ? */
if (!pe)
return -ENODEV;
/* Unsupported operation ? */
if (!eeh_ops || !eeh_ops->err_inject)
return -ENOENT;
/* Check on PCI error type */
if (type != EEH_ERR_TYPE_32 && type != EEH_ERR_TYPE_64)
return -EINVAL;
/* Check on PCI error function */
if (func < EEH_ERR_FUNC_MIN || func > EEH_ERR_FUNC_MAX)
return -EINVAL;
return eeh_ops->err_inject(pe, type, func, addr, mask);
}
EXPORT_SYMBOL_GPL(eeh_pe_inject_err);
#ifdef CONFIG_PROC_FS
static int proc_eeh_show(struct seq_file *m, void *v)
{
if (!eeh_enabled()) {
seq_printf(m, "EEH Subsystem is globally disabled\n");
seq_printf(m, "eeh_total_mmio_ffs=%llu\n", eeh_stats.total_mmio_ffs);
} else {
seq_printf(m, "EEH Subsystem is enabled\n");
seq_printf(m,
"no device=%llu\n"
"no device node=%llu\n"
"no config address=%llu\n"
"check not wanted=%llu\n"
"eeh_total_mmio_ffs=%llu\n"
"eeh_false_positives=%llu\n"
"eeh_slot_resets=%llu\n",
eeh_stats.no_device,
eeh_stats.no_dn,
eeh_stats.no_cfg_addr,
eeh_stats.ignored_check,
eeh_stats.total_mmio_ffs,
eeh_stats.false_positives,
eeh_stats.slot_resets);
}
return 0;
}
#endif /* CONFIG_PROC_FS */
#ifdef CONFIG_DEBUG_FS
static struct pci_dev *eeh_debug_lookup_pdev(struct file *filp,
const char __user *user_buf,
size_t count, loff_t *ppos)
{
uint32_t domain, bus, dev, fn;
struct pci_dev *pdev;
char buf[20];
int ret;
memset(buf, 0, sizeof(buf));
ret = simple_write_to_buffer(buf, sizeof(buf)-1, ppos, user_buf, count);
if (!ret)
return ERR_PTR(-EFAULT);
ret = sscanf(buf, "%x:%x:%x.%x", &domain, &bus, &dev, &fn);
if (ret != 4) {
pr_err("%s: expected 4 args, got %d\n", __func__, ret);
return ERR_PTR(-EINVAL);
}
pdev = pci_get_domain_bus_and_slot(domain, bus, (dev << 3) | fn);
if (!pdev)
return ERR_PTR(-ENODEV);
return pdev;
}
static int eeh_enable_dbgfs_set(void *data, u64 val)
{
if (val)
eeh_clear_flag(EEH_FORCE_DISABLED);
else
eeh_add_flag(EEH_FORCE_DISABLED);
return 0;
}
static int eeh_enable_dbgfs_get(void *data, u64 *val)
{
if (eeh_enabled())
*val = 0x1ul;
else
*val = 0x0ul;
return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(eeh_enable_dbgfs_ops, eeh_enable_dbgfs_get,
eeh_enable_dbgfs_set, "0x%llx\n");
static ssize_t eeh_force_recover_write(struct file *filp,
const char __user *user_buf,
size_t count, loff_t *ppos)
{
struct pci_controller *hose;
uint32_t phbid, pe_no;
struct eeh_pe *pe;
char buf[20];
int ret;
ret = simple_write_to_buffer(buf, sizeof(buf), ppos, user_buf, count);
if (!ret)
return -EFAULT;
/*
* When PE is NULL the event is a "special" event. Rather than
* recovering a specific PE it forces the EEH core to scan for failed
* PHBs and recovers each. This needs to be done before any device
* recoveries can occur.
*/
if (!strncmp(buf, "hwcheck", 7)) {
__eeh_send_failure_event(NULL);
return count;
}
ret = sscanf(buf, "%x:%x", &phbid, &pe_no);
if (ret != 2)
return -EINVAL;
hose = pci_find_controller_for_domain(phbid);
if (!hose)
return -ENODEV;
/* Retrieve PE */
pe = eeh_pe_get(hose, pe_no);
if (!pe)
return -ENODEV;
/*
* We don't do any state checking here since the detection
* process is async to the recovery process. The recovery
* thread *should* not break even if we schedule a recovery
* from an odd state (e.g. PE removed, or recovery of a
* non-isolated PE)
*/
__eeh_send_failure_event(pe);
return ret < 0 ? ret : count;
}
static const struct file_operations eeh_force_recover_fops = {
.open = simple_open,
.llseek = no_llseek,
.write = eeh_force_recover_write,
};
static ssize_t eeh_debugfs_dev_usage(struct file *filp,
char __user *user_buf,
size_t count, loff_t *ppos)
{
static const char usage[] = "input format: <domain>:<bus>:<dev>.<fn>\n";
return simple_read_from_buffer(user_buf, count, ppos,
usage, sizeof(usage) - 1);
}
static ssize_t eeh_dev_check_write(struct file *filp,
const char __user *user_buf,
size_t count, loff_t *ppos)
{
struct pci_dev *pdev;
struct eeh_dev *edev;
int ret;
pdev = eeh_debug_lookup_pdev(filp, user_buf, count, ppos);
if (IS_ERR(pdev))
return PTR_ERR(pdev);
edev = pci_dev_to_eeh_dev(pdev);
if (!edev) {
pci_err(pdev, "No eeh_dev for this device!\n");
pci_dev_put(pdev);
return -ENODEV;
}
ret = eeh_dev_check_failure(edev);
pci_info(pdev, "eeh_dev_check_failure(%s) = %d\n",
pci_name(pdev), ret);
pci_dev_put(pdev);
return count;
}
static const struct file_operations eeh_dev_check_fops = {
.open = simple_open,
.llseek = no_llseek,
.write = eeh_dev_check_write,
.read = eeh_debugfs_dev_usage,
};
static int eeh_debugfs_break_device(struct pci_dev *pdev)
{
struct resource *bar = NULL;
void __iomem *mapped;
u16 old, bit;
int i, pos;
/* Do we have an MMIO BAR to disable? */
for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
struct resource *r = &pdev->resource[i];
if (!r->flags || !r->start)
continue;
if (r->flags & IORESOURCE_IO)
continue;
if (r->flags & IORESOURCE_UNSET)
continue;
bar = r;
break;
}
if (!bar) {
pci_err(pdev, "Unable to find Memory BAR to cause EEH with\n");
return -ENXIO;
}
pci_err(pdev, "Going to break: %pR\n", bar);
if (pdev->is_virtfn) {
#ifndef CONFIG_PCI_IOV
return -ENXIO;
#else
/*
* VFs don't have a per-function COMMAND register, so the best
* we can do is clear the Memory Space Enable bit in the PF's
* SRIOV control reg.
*
* Unfortunately, this requires that we have a PF (i.e doesn't
* work for a passed-through VF) and it has the potential side
* effect of also causing an EEH on every other VF under the
* PF. Oh well.
*/
pdev = pdev->physfn;
if (!pdev)
return -ENXIO; /* passed through VFs have no PF */
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_SRIOV);
pos += PCI_SRIOV_CTRL;
bit = PCI_SRIOV_CTRL_MSE;
#endif /* !CONFIG_PCI_IOV */
} else {
bit = PCI_COMMAND_MEMORY;
pos = PCI_COMMAND;
}
/*
* Process here is:
*
* 1. Disable Memory space.
*
* 2. Perform an MMIO to the device. This should result in an error
* (CA / UR) being raised by the device which results in an EEH
* PE freeze. Using the in_8() accessor skips the eeh detection hook
* so the freeze hook so the EEH Detection machinery won't be
* triggered here. This is to match the usual behaviour of EEH
* where the HW will asyncronously freeze a PE and it's up to
* the kernel to notice and deal with it.
*
* 3. Turn Memory space back on. This is more important for VFs
* since recovery will probably fail if we don't. For normal
* the COMMAND register is reset as a part of re-initialising
* the device.
*
* Breaking stuff is the point so who cares if it's racy ;)
*/
pci_read_config_word(pdev, pos, &old);
mapped = ioremap(bar->start, PAGE_SIZE);
if (!mapped) {
pci_err(pdev, "Unable to map MMIO BAR %pR\n", bar);
return -ENXIO;
}
pci_write_config_word(pdev, pos, old & ~bit);
in_8(mapped);
pci_write_config_word(pdev, pos, old);
iounmap(mapped);
return 0;
}
static ssize_t eeh_dev_break_write(struct file *filp,
const char __user *user_buf,
size_t count, loff_t *ppos)
{
struct pci_dev *pdev;
int ret;
pdev = eeh_debug_lookup_pdev(filp, user_buf, count, ppos);
if (IS_ERR(pdev))
return PTR_ERR(pdev);
ret = eeh_debugfs_break_device(pdev);
pci_dev_put(pdev);
if (ret < 0)
return ret;
return count;
}
static const struct file_operations eeh_dev_break_fops = {
.open = simple_open,
.llseek = no_llseek,
.write = eeh_dev_break_write,
.read = eeh_debugfs_dev_usage,
};
static ssize_t eeh_dev_can_recover(struct file *filp,
const char __user *user_buf,
size_t count, loff_t *ppos)
{
struct pci_driver *drv;
struct pci_dev *pdev;
size_t ret;
pdev = eeh_debug_lookup_pdev(filp, user_buf, count, ppos);
if (IS_ERR(pdev))
return PTR_ERR(pdev);
/*
* In order for error recovery to work the driver needs to implement
* .error_detected(), so it can quiesce IO to the device, and
* .slot_reset() so it can re-initialise the device after a reset.
*
* Ideally they'd implement .resume() too, but some drivers which
* we need to support (notably IPR) don't so I guess we can tolerate
* that.
*
* .mmio_enabled() is mostly there as a work-around for devices which
* take forever to re-init after a hot reset. Implementing that is
* strictly optional.
*/
drv = pci_dev_driver(pdev);
if (drv &&
drv->err_handler &&
drv->err_handler->error_detected &&
drv->err_handler->slot_reset) {
ret = count;
} else {
ret = -EOPNOTSUPP;
}
pci_dev_put(pdev);
return ret;
}
static const struct file_operations eeh_dev_can_recover_fops = {
.open = simple_open,
.llseek = no_llseek,
.write = eeh_dev_can_recover,
.read = eeh_debugfs_dev_usage,
};
#endif
static int __init eeh_init_proc(void)
{
if (machine_is(pseries) || machine_is(powernv)) {
proc_create_single("powerpc/eeh", 0, NULL, proc_eeh_show);
#ifdef CONFIG_DEBUG_FS
debugfs_create_file_unsafe("eeh_enable", 0600,
powerpc_debugfs_root, NULL,
&eeh_enable_dbgfs_ops);
debugfs_create_u32("eeh_max_freezes", 0600,
powerpc_debugfs_root, &eeh_max_freezes);
debugfs_create_bool("eeh_disable_recovery", 0600,
powerpc_debugfs_root,
&eeh_debugfs_no_recover);
debugfs_create_file_unsafe("eeh_dev_check", 0600,
powerpc_debugfs_root, NULL,
&eeh_dev_check_fops);
debugfs_create_file_unsafe("eeh_dev_break", 0600,
powerpc_debugfs_root, NULL,
&eeh_dev_break_fops);
debugfs_create_file_unsafe("eeh_force_recover", 0600,
powerpc_debugfs_root, NULL,
&eeh_force_recover_fops);
debugfs_create_file_unsafe("eeh_dev_can_recover", 0600,
powerpc_debugfs_root, NULL,
&eeh_dev_can_recover_fops);
eeh_cache_debugfs_init();
#endif
}
return 0;
}
__initcall(eeh_init_proc);
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