1eeb66a1bb
This patch moves the die notifier handling to common code. Previous various architectures had exactly the same code for it. Note that the new code is compiled unconditionally, this should be understood as an appel to the other architecture maintainer to implement support for it aswell (aka sprinkling a notify_die or two in the proper place) arm had a notifiy_die that did something totally different, I renamed it to arm_notify_die as part of the patch and made it static to the file it's declared and used at. avr32 used to pass slightly less information through this interface and I brought it into line with the other architectures. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix vmalloc_sync_all bustage] [bryan.wu@analog.com: fix vmalloc_sync_all in nommu] Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: <linux-arch@vger.kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Bryan Wu <bryan.wu@analog.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
136 lines
3.0 KiB
C
136 lines
3.0 KiB
C
/*
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* Architecture specific (x86_64) functions for kexec based crash dumps.
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*
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* Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
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*
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* Copyright (C) IBM Corporation, 2004. All rights reserved.
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*
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*/
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#include <linux/init.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/smp.h>
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#include <linux/irq.h>
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#include <linux/reboot.h>
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#include <linux/kexec.h>
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#include <linux/delay.h>
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#include <linux/elf.h>
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#include <linux/elfcore.h>
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#include <linux/kdebug.h>
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#include <asm/processor.h>
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#include <asm/hardirq.h>
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#include <asm/nmi.h>
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#include <asm/hw_irq.h>
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#include <asm/mach_apic.h>
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/* This keeps a track of which one is crashing cpu. */
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static int crashing_cpu;
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#ifdef CONFIG_SMP
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static atomic_t waiting_for_crash_ipi;
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static int crash_nmi_callback(struct notifier_block *self,
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unsigned long val, void *data)
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{
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struct pt_regs *regs;
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int cpu;
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if (val != DIE_NMI_IPI)
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return NOTIFY_OK;
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regs = ((struct die_args *)data)->regs;
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cpu = raw_smp_processor_id();
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/*
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* Don't do anything if this handler is invoked on crashing cpu.
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* Otherwise, system will completely hang. Crashing cpu can get
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* an NMI if system was initially booted with nmi_watchdog parameter.
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*/
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if (cpu == crashing_cpu)
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return NOTIFY_STOP;
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local_irq_disable();
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crash_save_cpu(regs, cpu);
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disable_local_APIC();
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atomic_dec(&waiting_for_crash_ipi);
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/* Assume hlt works */
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for(;;)
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halt();
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return 1;
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}
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static void smp_send_nmi_allbutself(void)
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{
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send_IPI_allbutself(NMI_VECTOR);
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}
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/*
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* This code is a best effort heuristic to get the
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* other cpus to stop executing. So races with
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* cpu hotplug shouldn't matter.
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*/
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static struct notifier_block crash_nmi_nb = {
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.notifier_call = crash_nmi_callback,
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};
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static void nmi_shootdown_cpus(void)
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{
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unsigned long msecs;
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atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
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if (register_die_notifier(&crash_nmi_nb))
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return; /* return what? */
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/*
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* Ensure the new callback function is set before sending
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* out the NMI
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*/
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wmb();
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smp_send_nmi_allbutself();
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msecs = 1000; /* Wait at most a second for the other cpus to stop */
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while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
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mdelay(1);
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msecs--;
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}
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/* Leave the nmi callback set */
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disable_local_APIC();
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}
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#else
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static void nmi_shootdown_cpus(void)
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{
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/* There are no cpus to shootdown */
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}
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#endif
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void machine_crash_shutdown(struct pt_regs *regs)
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{
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/*
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* This function is only called after the system
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* has panicked or is otherwise in a critical state.
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* The minimum amount of code to allow a kexec'd kernel
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* to run successfully needs to happen here.
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*
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* In practice this means shooting down the other cpus in
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* an SMP system.
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*/
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/* The kernel is broken so disable interrupts */
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local_irq_disable();
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/* Make a note of crashing cpu. Will be used in NMI callback.*/
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crashing_cpu = smp_processor_id();
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nmi_shootdown_cpus();
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if(cpu_has_apic)
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disable_local_APIC();
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disable_IO_APIC();
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crash_save_cpu(regs, smp_processor_id());
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}
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