linux/arch/sparc/prom/p1275.c

55 lines
1.1 KiB
C
Raw Normal View History

/*
* p1275.c: Sun IEEE 1275 PROM low level interface routines
*
* Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/string.h>
#include <linux/spinlock.h>
sparc64: Fix lockdep warnings on reboot on Ultra-5 Inconsistently, the raw_* IRQ routines do not interact with and update the irqflags tracing and lockdep state, whereas the raw_* spinlock interfaces do. This causes problems in p1275_cmd_direct() because we disable hardirqs by hand using raw_local_irq_restore() and then do a raw_spin_lock() which triggers a lockdep trace because the CPU's hw IRQ state doesn't match IRQ tracing's internal software copy of that state. The CPU's irqs are disabled, yet current->hardirqs_enabled is true. ==================== reboot: Restarting system ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:3536 check_flags+0x7c/0x240() DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled) Modules linked in: openpromfs CPU: 0 PID: 1 Comm: systemd-shutdow Tainted: G W 3.17.0-dirty #145 Call Trace: [000000000045919c] warn_slowpath_common+0x5c/0xa0 [0000000000459210] warn_slowpath_fmt+0x30/0x40 [000000000048f41c] check_flags+0x7c/0x240 [0000000000493280] lock_acquire+0x20/0x1c0 [0000000000832b70] _raw_spin_lock+0x30/0x60 [000000000068f2fc] p1275_cmd_direct+0x1c/0x60 [000000000068ed28] prom_reboot+0x28/0x40 [000000000043610c] machine_restart+0x4c/0x80 [000000000047d2d4] kernel_restart+0x54/0x80 [000000000047d618] SyS_reboot+0x138/0x200 [00000000004060b4] linux_sparc_syscall32+0x34/0x60 ---[ end trace 5c439fe81c05a100 ]--- possible reason: unannotated irqs-off. irq event stamp: 2010267 hardirqs last enabled at (2010267): [<000000000049a358>] vprintk_emit+0x4b8/0x580 hardirqs last disabled at (2010266): [<0000000000499f08>] vprintk_emit+0x68/0x580 softirqs last enabled at (2010046): [<000000000045d278>] __do_softirq+0x378/0x4a0 softirqs last disabled at (2010039): [<000000000042bf08>] do_softirq_own_stack+0x28/0x40 Resetting ... ==================== Use local_* variables of the hw IRQ interfaces so that IRQ tracing sees all of our changes. Reported-by: Meelis Roos <mroos@linux.ee> Tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-11 03:49:16 +08:00
#include <linux/irqflags.h>
#include <asm/openprom.h>
#include <asm/oplib.h>
#include <asm/spitfire.h>
#include <asm/pstate.h>
[SPARC64]: Initial LDOM cpu hotplug support. Only adding cpus is supports at the moment, removal will come next. When new cpus are configured, the machine description is updated. When we get the configure request we pass in a cpu mask of to-be-added cpus to the mdesc CPU node parser so it only fetches information for those cpus. That code also proceeds to update the SMT/multi-core scheduling bitmaps. cpu_up() does all the work and we return the status back over the DS channel. CPUs via dr-cpu need to be booted straight out of the hypervisor, and this requires: 1) A new trampoline mechanism. CPUs are booted straight out of the hypervisor with MMU disabled and running in physical addresses with no mappings installed in the TLB. The new hvtramp.S code sets up the critical cpu state, installs the locked TLB mappings for the kernel, and turns the MMU on. It then proceeds to follow the logic of the existing trampoline.S SMP cpu bringup code. 2) All calls into OBP have to be disallowed when domaining is enabled. Since cpus boot straight into the kernel from the hypervisor, OBP has no state about that cpu and therefore cannot handle being invoked on that cpu. Luckily it's only a handful of interfaces which can be called after the OBP device tree is obtained. For example, rebooting, halting, powering-off, and setting options node variables. CPU removal support will require some infrastructure changes here. Namely we'll have to process the requests via a true kernel thread instead of in a workqueue. workqueues run on a per-cpu thread, but when unconfiguring we might need to force the thread to execute on another cpu if the current cpu is the one being removed. Removal of a cpu also causes the kernel to destroy that cpu's workqueue running thread. Another issue on removal is that we may have interrupts still pointing to the cpu-to-be-removed. So new code will be needed to walk the active INO list and retarget those cpus as-needed. Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-14 07:03:42 +08:00
#include <asm/ldc.h>
struct {
long prom_callback; /* 0x00 */
void (*prom_cif_handler)(long *); /* 0x08 */
} p1275buf;
extern void prom_world(int);
extern void prom_cif_direct(unsigned long *args);
extern void prom_cif_callback(void);
/*
* This provides SMP safety on the p1275buf.
*/
DEFINE_RAW_SPINLOCK(prom_entry_lock);
void p1275_cmd_direct(unsigned long *args)
{
unsigned long flags;
sparc64: Fix lockdep warnings on reboot on Ultra-5 Inconsistently, the raw_* IRQ routines do not interact with and update the irqflags tracing and lockdep state, whereas the raw_* spinlock interfaces do. This causes problems in p1275_cmd_direct() because we disable hardirqs by hand using raw_local_irq_restore() and then do a raw_spin_lock() which triggers a lockdep trace because the CPU's hw IRQ state doesn't match IRQ tracing's internal software copy of that state. The CPU's irqs are disabled, yet current->hardirqs_enabled is true. ==================== reboot: Restarting system ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:3536 check_flags+0x7c/0x240() DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled) Modules linked in: openpromfs CPU: 0 PID: 1 Comm: systemd-shutdow Tainted: G W 3.17.0-dirty #145 Call Trace: [000000000045919c] warn_slowpath_common+0x5c/0xa0 [0000000000459210] warn_slowpath_fmt+0x30/0x40 [000000000048f41c] check_flags+0x7c/0x240 [0000000000493280] lock_acquire+0x20/0x1c0 [0000000000832b70] _raw_spin_lock+0x30/0x60 [000000000068f2fc] p1275_cmd_direct+0x1c/0x60 [000000000068ed28] prom_reboot+0x28/0x40 [000000000043610c] machine_restart+0x4c/0x80 [000000000047d2d4] kernel_restart+0x54/0x80 [000000000047d618] SyS_reboot+0x138/0x200 [00000000004060b4] linux_sparc_syscall32+0x34/0x60 ---[ end trace 5c439fe81c05a100 ]--- possible reason: unannotated irqs-off. irq event stamp: 2010267 hardirqs last enabled at (2010267): [<000000000049a358>] vprintk_emit+0x4b8/0x580 hardirqs last disabled at (2010266): [<0000000000499f08>] vprintk_emit+0x68/0x580 softirqs last enabled at (2010046): [<000000000045d278>] __do_softirq+0x378/0x4a0 softirqs last disabled at (2010039): [<000000000042bf08>] do_softirq_own_stack+0x28/0x40 Resetting ... ==================== Use local_* variables of the hw IRQ interfaces so that IRQ tracing sees all of our changes. Reported-by: Meelis Roos <mroos@linux.ee> Tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-11 03:49:16 +08:00
local_save_flags(flags);
local_irq_restore((unsigned long)PIL_NMI);
raw_spin_lock(&prom_entry_lock);
prom_world(1);
prom_cif_direct(args);
prom_world(0);
raw_spin_unlock(&prom_entry_lock);
sparc64: Fix lockdep warnings on reboot on Ultra-5 Inconsistently, the raw_* IRQ routines do not interact with and update the irqflags tracing and lockdep state, whereas the raw_* spinlock interfaces do. This causes problems in p1275_cmd_direct() because we disable hardirqs by hand using raw_local_irq_restore() and then do a raw_spin_lock() which triggers a lockdep trace because the CPU's hw IRQ state doesn't match IRQ tracing's internal software copy of that state. The CPU's irqs are disabled, yet current->hardirqs_enabled is true. ==================== reboot: Restarting system ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:3536 check_flags+0x7c/0x240() DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled) Modules linked in: openpromfs CPU: 0 PID: 1 Comm: systemd-shutdow Tainted: G W 3.17.0-dirty #145 Call Trace: [000000000045919c] warn_slowpath_common+0x5c/0xa0 [0000000000459210] warn_slowpath_fmt+0x30/0x40 [000000000048f41c] check_flags+0x7c/0x240 [0000000000493280] lock_acquire+0x20/0x1c0 [0000000000832b70] _raw_spin_lock+0x30/0x60 [000000000068f2fc] p1275_cmd_direct+0x1c/0x60 [000000000068ed28] prom_reboot+0x28/0x40 [000000000043610c] machine_restart+0x4c/0x80 [000000000047d2d4] kernel_restart+0x54/0x80 [000000000047d618] SyS_reboot+0x138/0x200 [00000000004060b4] linux_sparc_syscall32+0x34/0x60 ---[ end trace 5c439fe81c05a100 ]--- possible reason: unannotated irqs-off. irq event stamp: 2010267 hardirqs last enabled at (2010267): [<000000000049a358>] vprintk_emit+0x4b8/0x580 hardirqs last disabled at (2010266): [<0000000000499f08>] vprintk_emit+0x68/0x580 softirqs last enabled at (2010046): [<000000000045d278>] __do_softirq+0x378/0x4a0 softirqs last disabled at (2010039): [<000000000042bf08>] do_softirq_own_stack+0x28/0x40 Resetting ... ==================== Use local_* variables of the hw IRQ interfaces so that IRQ tracing sees all of our changes. Reported-by: Meelis Roos <mroos@linux.ee> Tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-11 03:49:16 +08:00
local_irq_restore(flags);
}
void prom_cif_init(void *cif_handler, void *cif_stack)
{
p1275buf.prom_cif_handler = (void (*)(long *))cif_handler;
}