260 строки
6.1 KiB
C
260 строки
6.1 KiB
C
/*
|
|
* 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.
|
|
*
|
|
*/
|
|
|
|
#undef DEBUG
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/kexec.h>
|
|
#include <linux/bootmem.h>
|
|
#include <linux/crash_dump.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/elf.h>
|
|
#include <linux/elfcore.h>
|
|
#include <linux/init.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/types.h>
|
|
#include <linux/irq.h>
|
|
|
|
#include <asm/processor.h>
|
|
#include <asm/machdep.h>
|
|
#include <asm/kexec.h>
|
|
#include <asm/kdump.h>
|
|
#include <asm/lmb.h>
|
|
#include <asm/firmware.h>
|
|
#include <asm/smp.h>
|
|
|
|
#ifdef DEBUG
|
|
#include <asm/udbg.h>
|
|
#define DBG(fmt...) udbg_printf(fmt)
|
|
#else
|
|
#define DBG(fmt...)
|
|
#endif
|
|
|
|
/* This keeps a track of which one is crashing cpu. */
|
|
int crashing_cpu = -1;
|
|
static cpumask_t cpus_in_crash = CPU_MASK_NONE;
|
|
cpumask_t cpus_in_sr = CPU_MASK_NONE;
|
|
|
|
#ifdef CONFIG_SMP
|
|
static atomic_t enter_on_soft_reset = ATOMIC_INIT(0);
|
|
|
|
void crash_ipi_callback(struct pt_regs *regs)
|
|
{
|
|
int cpu = smp_processor_id();
|
|
|
|
if (!cpu_online(cpu))
|
|
return;
|
|
|
|
hard_irq_disable();
|
|
if (!cpu_isset(cpu, cpus_in_crash))
|
|
crash_save_cpu(regs, cpu);
|
|
cpu_set(cpu, cpus_in_crash);
|
|
|
|
/*
|
|
* Entered via soft-reset - could be the kdump
|
|
* process is invoked using soft-reset or user activated
|
|
* it if some CPU did not respond to an IPI.
|
|
* For soft-reset, the secondary CPU can enter this func
|
|
* twice. 1 - using IPI, and 2. soft-reset.
|
|
* Tell the kexec CPU that entered via soft-reset and ready
|
|
* to go down.
|
|
*/
|
|
if (cpu_isset(cpu, cpus_in_sr)) {
|
|
cpu_clear(cpu, cpus_in_sr);
|
|
atomic_inc(&enter_on_soft_reset);
|
|
}
|
|
|
|
/*
|
|
* Starting the kdump boot.
|
|
* This barrier is needed to make sure that all CPUs are stopped.
|
|
* If not, soft-reset will be invoked to bring other CPUs.
|
|
*/
|
|
while (!cpu_isset(crashing_cpu, cpus_in_crash))
|
|
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 */
|
|
}
|
|
|
|
/*
|
|
* Wait until all CPUs are entered via soft-reset.
|
|
*/
|
|
static void crash_soft_reset_check(int cpu)
|
|
{
|
|
unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
|
|
|
|
cpu_clear(cpu, cpus_in_sr);
|
|
while (atomic_read(&enter_on_soft_reset) != ncpus)
|
|
cpu_relax();
|
|
}
|
|
|
|
|
|
static void crash_kexec_prepare_cpus(int cpu)
|
|
{
|
|
unsigned int msecs;
|
|
|
|
unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
|
|
|
|
crash_send_ipi(crash_ipi_callback);
|
|
smp_wmb();
|
|
|
|
/*
|
|
* FIXME: Until we will have the way to stop other CPUSs reliabally,
|
|
* the crash CPU will send an IPI and wait for other CPUs to
|
|
* respond.
|
|
* Delay of at least 10 seconds.
|
|
*/
|
|
printk(KERN_EMERG "Sending IPI to other cpus...\n");
|
|
msecs = 10000;
|
|
while ((cpus_weight(cpus_in_crash) < ncpus) && (--msecs > 0)) {
|
|
cpu_relax();
|
|
mdelay(1);
|
|
}
|
|
|
|
/* Would it be better to replace the trap vector here? */
|
|
|
|
/*
|
|
* FIXME: In case if we do not get all CPUs, one possibility: ask the
|
|
* user to do soft reset such that we get all.
|
|
* Soft-reset will be used until better mechanism is implemented.
|
|
*/
|
|
if (cpus_weight(cpus_in_crash) < ncpus) {
|
|
printk(KERN_EMERG "done waiting: %d cpu(s) not responding\n",
|
|
ncpus - cpus_weight(cpus_in_crash));
|
|
printk(KERN_EMERG "Activate soft-reset to stop other cpu(s)\n");
|
|
cpus_in_sr = CPU_MASK_NONE;
|
|
atomic_set(&enter_on_soft_reset, 0);
|
|
while (cpus_weight(cpus_in_crash) < ncpus)
|
|
cpu_relax();
|
|
}
|
|
/*
|
|
* Make sure all CPUs are entered via soft-reset if the kdump is
|
|
* invoked using soft-reset.
|
|
*/
|
|
if (cpu_isset(cpu, cpus_in_sr))
|
|
crash_soft_reset_check(cpu);
|
|
/* Leave the IPI callback set */
|
|
}
|
|
|
|
/*
|
|
* This function will be called by secondary cpus or by kexec cpu
|
|
* if soft-reset is activated to stop some CPUs.
|
|
*/
|
|
void crash_kexec_secondary(struct pt_regs *regs)
|
|
{
|
|
int cpu = smp_processor_id();
|
|
unsigned long flags;
|
|
int msecs = 5;
|
|
|
|
local_irq_save(flags);
|
|
/* Wait 5ms if the kexec CPU is not entered yet. */
|
|
while (crashing_cpu < 0) {
|
|
if (--msecs < 0) {
|
|
/*
|
|
* Either kdump image is not loaded or
|
|
* kdump process is not started - Probably xmon
|
|
* exited using 'x'(exit and recover) or
|
|
* kexec_should_crash() failed for all running tasks.
|
|
*/
|
|
cpu_clear(cpu, cpus_in_sr);
|
|
local_irq_restore(flags);
|
|
return;
|
|
}
|
|
mdelay(1);
|
|
cpu_relax();
|
|
}
|
|
if (cpu == crashing_cpu) {
|
|
/*
|
|
* Panic CPU will enter this func only via soft-reset.
|
|
* Wait until all secondary CPUs entered and
|
|
* then start kexec boot.
|
|
*/
|
|
crash_soft_reset_check(cpu);
|
|
cpu_set(crashing_cpu, cpus_in_crash);
|
|
if (ppc_md.kexec_cpu_down)
|
|
ppc_md.kexec_cpu_down(1, 0);
|
|
machine_kexec(kexec_crash_image);
|
|
/* NOTREACHED */
|
|
}
|
|
crash_ipi_callback(regs);
|
|
}
|
|
|
|
#else
|
|
static void crash_kexec_prepare_cpus(int cpu)
|
|
{
|
|
/*
|
|
* move the secondarys 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
|
|
}
|
|
|
|
void crash_kexec_secondary(struct pt_regs *regs)
|
|
{
|
|
cpus_in_sr = CPU_MASK_NONE;
|
|
}
|
|
#endif
|
|
|
|
void default_machine_crash_shutdown(struct pt_regs *regs)
|
|
{
|
|
unsigned int irq;
|
|
|
|
/*
|
|
* 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();
|
|
|
|
for_each_irq(irq) {
|
|
struct irq_desc *desc = irq_desc + irq;
|
|
|
|
if (desc->status & IRQ_INPROGRESS)
|
|
desc->chip->eoi(irq);
|
|
|
|
if (!(desc->status & IRQ_DISABLED))
|
|
desc->chip->disable(irq);
|
|
}
|
|
|
|
/*
|
|
* 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();
|
|
crash_save_cpu(regs, crashing_cpu);
|
|
crash_kexec_prepare_cpus(crashing_cpu);
|
|
cpu_set(crashing_cpu, cpus_in_crash);
|
|
if (ppc_md.kexec_cpu_down)
|
|
ppc_md.kexec_cpu_down(1, 0);
|
|
}
|