linux/arch/powerpc/kernel/crash.c

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/*
* Architecture specific (PPC64) functions for kexec based crash dumps.
*
* Copyright (C) 2005, IBM Corp.
*
* Created by: Haren Myneni
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*
*/
#include <linux/kernel.h>
#include <linux/smp.h>
#include <linux/reboot.h>
#include <linux/kexec.h>
#include <linux/export.h>
#include <linux/crash_dump.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/types.h>
#include <asm/processor.h>
#include <asm/machdep.h>
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
#include <asm/kexec.h>
#include <asm/kdump.h>
#include <asm/prom.h>
#include <asm/smp.h>
#include <asm/setjmp.h>
#include <asm/debug.h>
/*
* The primary CPU waits a while for all secondary CPUs to enter. This is to
* avoid sending an IPI if the secondary CPUs are entering
* crash_kexec_secondary on their own (eg via a system reset).
*
* The secondary timeout has to be longer than the primary. Both timeouts are
* in milliseconds.
*/
#define PRIMARY_TIMEOUT 500
#define SECONDARY_TIMEOUT 1000
#define IPI_TIMEOUT 10000
#define REAL_MODE_TIMEOUT 10000
/* This keeps a track of which one is the crashing cpu. */
int crashing_cpu = -1;
static int time_to_dump;
#define CRASH_HANDLER_MAX 3
/* NULL terminated list of shutdown handles */
static crash_shutdown_t crash_shutdown_handles[CRASH_HANDLER_MAX+1];
static DEFINE_SPINLOCK(crash_handlers_lock);
static unsigned long crash_shutdown_buf[JMP_BUF_LEN];
static int crash_shutdown_cpu = -1;
static int handle_fault(struct pt_regs *regs)
{
if (crash_shutdown_cpu == smp_processor_id())
longjmp(crash_shutdown_buf, 1);
return 0;
}
#ifdef CONFIG_SMP
static atomic_t cpus_in_crash;
void crash_ipi_callback(struct pt_regs *regs)
{
static cpumask_t cpus_state_saved = CPU_MASK_NONE;
int cpu = smp_processor_id();
if (!cpu_online(cpu))
return;
hard_irq_disable();
if (!cpumask_test_cpu(cpu, &cpus_state_saved)) {
crash_save_cpu(regs, cpu);
cpumask_set_cpu(cpu, &cpus_state_saved);
}
atomic_inc(&cpus_in_crash);
smp_mb__after_atomic_inc();
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
/*
* Starting the kdump boot.
* This barrier is needed to make sure that all CPUs are stopped.
*/
while (!time_to_dump)
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
cpu_relax();
if (ppc_md.kexec_cpu_down)
ppc_md.kexec_cpu_down(1, 1);
#ifdef CONFIG_PPC64
kexec_smp_wait();
#else
for (;;); /* FIXME */
#endif
/* NOTREACHED */
}
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
static void crash_kexec_prepare_cpus(int cpu)
{
unsigned int msecs;
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
int tries = 0;
int (*old_handler)(struct pt_regs *regs);
printk(KERN_EMERG "Sending IPI to other CPUs\n");
crash_send_ipi(crash_ipi_callback);
smp_wmb();
again:
/*
* FIXME: Until we will have the way to stop other CPUs reliably,
* the crash CPU will send an IPI and wait for other CPUs to
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
* respond.
*/
msecs = IPI_TIMEOUT;
while ((atomic_read(&cpus_in_crash) < ncpus) && (--msecs > 0))
mdelay(1);
/* Would it be better to replace the trap vector here? */
if (atomic_read(&cpus_in_crash) >= ncpus) {
printk(KERN_EMERG "IPI complete\n");
return;
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
}
printk(KERN_EMERG "ERROR: %d cpu(s) not responding\n",
ncpus - atomic_read(&cpus_in_crash));
/*
* If we have a panic timeout set then we can't wait indefinitely
* for someone to activate system reset. We also give up on the
* second time through if system reset fail to work.
*/
if ((panic_timeout > 0) || (tries > 0))
return;
/*
* A system reset will cause all CPUs to take an 0x100 exception.
* The primary CPU returns here via setjmp, and the secondary
* CPUs reexecute the crash_kexec_secondary path.
*/
old_handler = __debugger;
__debugger = handle_fault;
crash_shutdown_cpu = smp_processor_id();
if (setjmp(crash_shutdown_buf) == 0) {
printk(KERN_EMERG "Activate system reset (dumprestart) "
"to stop other cpu(s)\n");
/*
* A system reset will force all CPUs to execute the
* crash code again. We need to reset cpus_in_crash so we
* wait for everyone to do this.
*/
atomic_set(&cpus_in_crash, 0);
smp_mb();
while (atomic_read(&cpus_in_crash) < ncpus)
cpu_relax();
}
crash_shutdown_cpu = -1;
__debugger = old_handler;
tries++;
goto again;
}
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
/*
* This function will be called by secondary cpus.
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
*/
void crash_kexec_secondary(struct pt_regs *regs)
{
unsigned long flags;
int msecs = SECONDARY_TIMEOUT;
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
local_irq_save(flags);
/* Wait for the primary crash CPU to signal its progress */
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
while (crashing_cpu < 0) {
if (--msecs < 0) {
/* No response, kdump image may not have been loaded */
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
local_irq_restore(flags);
return;
}
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
mdelay(1);
}
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
crash_ipi_callback(regs);
}
#else /* ! CONFIG_SMP */
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
static void crash_kexec_prepare_cpus(int cpu)
{
/*
* move the secondaries to us so that we can copy
* the new kernel 0-0x100 safely
*
* do this if kexec in setup.c ?
*/
#ifdef CONFIG_PPC64
smp_release_cpus();
#else
/* FIXME */
#endif
}
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
void crash_kexec_secondary(struct pt_regs *regs)
{
}
#endif /* CONFIG_SMP */
/* wait for all the CPUs to hit real mode but timeout if they don't come in */
#if defined(CONFIG_SMP) && defined(CONFIG_PPC_STD_MMU_64)
static void crash_kexec_wait_realmode(int cpu)
{
unsigned int msecs;
int i;
msecs = REAL_MODE_TIMEOUT;
for (i=0; i < nr_cpu_ids && msecs > 0; i++) {
if (i == cpu)
continue;
while (paca[i].kexec_state < KEXEC_STATE_REAL_MODE) {
barrier();
if (!cpu_possible(i) || !cpu_online(i) || (msecs <= 0))
break;
msecs--;
mdelay(1);
}
}
mb();
}
#else
static inline void crash_kexec_wait_realmode(int cpu) {}
#endif /* CONFIG_SMP && CONFIG_PPC_STD_MMU_64 */
/*
* Register a function to be called on shutdown. Only use this if you
* can't reset your device in the second kernel.
*/
int crash_shutdown_register(crash_shutdown_t handler)
{
unsigned int i, rc;
spin_lock(&crash_handlers_lock);
for (i = 0 ; i < CRASH_HANDLER_MAX; i++)
if (!crash_shutdown_handles[i]) {
/* Insert handle at first empty entry */
crash_shutdown_handles[i] = handler;
rc = 0;
break;
}
if (i == CRASH_HANDLER_MAX) {
printk(KERN_ERR "Crash shutdown handles full, "
"not registered.\n");
rc = 1;
}
spin_unlock(&crash_handlers_lock);
return rc;
}
EXPORT_SYMBOL(crash_shutdown_register);
int crash_shutdown_unregister(crash_shutdown_t handler)
{
unsigned int i, rc;
spin_lock(&crash_handlers_lock);
for (i = 0 ; i < CRASH_HANDLER_MAX; i++)
if (crash_shutdown_handles[i] == handler)
break;
if (i == CRASH_HANDLER_MAX) {
printk(KERN_ERR "Crash shutdown handle not found\n");
rc = 1;
} else {
/* Shift handles down */
for (; crash_shutdown_handles[i]; i++)
crash_shutdown_handles[i] =
crash_shutdown_handles[i+1];
rc = 0;
}
spin_unlock(&crash_handlers_lock);
return rc;
}
EXPORT_SYMBOL(crash_shutdown_unregister);
void default_machine_crash_shutdown(struct pt_regs *regs)
{
unsigned int i;
int (*old_handler)(struct pt_regs *regs);
/*
* This function is only called after the system
* has panicked or is otherwise in a critical state.
* The minimum amount of code to allow a kexec'd kernel
* to run successfully needs to happen here.
*
* In practice this means stopping other cpus in
* an SMP system.
* The kernel is broken so disable interrupts.
*/
hard_irq_disable();
/*
* Make a note of crashing cpu. Will be used in machine_kexec
* such that another IPI will not be sent.
*/
crashing_cpu = smp_processor_id();
/*
* If we came in via system reset, wait a while for the secondary
* CPUs to enter.
*/
if (TRAP(regs) == 0x100)
mdelay(PRIMARY_TIMEOUT);
crash_kexec_prepare_cpus(crashing_cpu);
crash_save_cpu(regs, crashing_cpu);
time_to_dump = 1;
crash_kexec_wait_realmode(crashing_cpu);
machine_kexec_mask_interrupts();
/*
* Call registered shutdown routines safely. Swap out
* __debugger_fault_handler, and replace on exit.
*/
old_handler = __debugger_fault_handler;
__debugger_fault_handler = handle_fault;
crash_shutdown_cpu = smp_processor_id();
for (i = 0; crash_shutdown_handles[i]; i++) {
if (setjmp(crash_shutdown_buf) == 0) {
/*
* Insert syncs and delay to ensure
* instructions in the dangerous region don't
* leak away from this protected region.
*/
asm volatile("sync; isync");
/* dangerous region */
crash_shutdown_handles[i]();
asm volatile("sync; isync");
}
}
crash_shutdown_cpu = -1;
__debugger_fault_handler = old_handler;
[POWERPC] Add the use of the firmware soft-reset-nmi to kdump. With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-23 22:29:34 +00:00
if (ppc_md.kexec_cpu_down)
ppc_md.kexec_cpu_down(1, 0);
}