diff options
Diffstat (limited to 'arch/powerpc/kernel/crash.c')
| -rw-r--r-- | arch/powerpc/kernel/crash.c | 374 |
1 files changed, 0 insertions, 374 deletions
diff --git a/arch/powerpc/kernel/crash.c b/arch/powerpc/kernel/crash.c deleted file mode 100644 index d488311efab1..000000000000 --- a/arch/powerpc/kernel/crash.c +++ /dev/null @@ -1,374 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * Architecture specific (PPC64) functions for kexec based crash dumps. - * - * Copyright (C) 2005, IBM Corp. - * - * Created by: Haren Myneni - */ - -#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/irq.h> -#include <linux/types.h> - -#include <asm/processor.h> -#include <asm/machdep.h> -#include <asm/kexec.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 - -static int time_to_dump; -/* - * crash_wake_offline should be set to 1 by platforms that intend to wake - * up offline cpus prior to jumping to a kdump kernel. Currently powernv - * sets it to 1, since we want to avoid things from happening when an - * offline CPU wakes up due to something like an HMI (malfunction error), - * which propagates to all threads. - */ -int crash_wake_offline; - -#define CRASH_HANDLER_MAX 3 -/* List of shutdown handles */ -static crash_shutdown_t crash_shutdown_handles[CRASH_HANDLER_MAX]; -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(); - - 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(); - - /* - * Starting the kdump boot. - * This barrier is needed to make sure that all CPUs are stopped. - */ - while (!time_to_dump) - 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 */ -} - -static void crash_kexec_prepare_cpus(int cpu) -{ - unsigned int msecs; - 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"); - - if (crash_wake_offline) - ncpus = num_present_cpus() - 1; - - 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 - * 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; - } - - 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; -} - -/* - * This function will be called by secondary cpus. - */ -void crash_kexec_secondary(struct pt_regs *regs) -{ - unsigned long flags; - int msecs = SECONDARY_TIMEOUT; - - local_irq_save(flags); - - /* Wait for the primary crash CPU to signal its progress */ - while (crashing_cpu < 0) { - if (--msecs < 0) { - /* No response, kdump image may not have been loaded */ - local_irq_restore(flags); - return; - } - - mdelay(1); - } - - crash_ipi_callback(regs); -} - -#else /* ! CONFIG_SMP */ - -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 -} - -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_PPC64) -static void __maybe_unused 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_ptrs[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_PPC64 */ - -/* - * 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 (; i < (CRASH_HANDLER_MAX - 1); i++) - crash_shutdown_handles[i] = - crash_shutdown_handles[i+1]; - /* - * Reset last entry to NULL now that it has been shifted down, - * this will allow new handles to be added here. - */ - crash_shutdown_handles[i] = NULL; - 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; i < CRASH_HANDLER_MAX && 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; - - if (ppc_md.kexec_cpu_down) - ppc_md.kexec_cpu_down(1, 0); -} |