diff options
| -rw-r--r-- | arch/powerpc/kernel/crash.c | 101 | ||||
| -rw-r--r-- | include/asm-powerpc/kexec.h | 3 |
2 files changed, 99 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/crash.c b/arch/powerpc/kernel/crash.c index 77c749a13378..571132ed12c1 100644 --- a/arch/powerpc/kernel/crash.c +++ b/arch/powerpc/kernel/crash.c @@ -32,6 +32,8 @@ #include <asm/lmb.h> #include <asm/firmware.h> #include <asm/smp.h> +#include <asm/system.h> +#include <asm/setjmp.h> #ifdef DEBUG #include <asm/udbg.h> @@ -45,6 +47,11 @@ int crashing_cpu = -1; static cpumask_t cpus_in_crash = CPU_MASK_NONE; cpumask_t cpus_in_sr = CPU_MASK_NONE; +#define CRASH_HANDLER_MAX 1 +/* NULL terminated list of shutdown handles */ +static crash_shutdown_t crash_shutdown_handles[CRASH_HANDLER_MAX+1]; +static DEFINE_SPINLOCK(crash_handlers_lock); + #ifdef CONFIG_SMP static atomic_t enter_on_soft_reset = ATOMIC_INIT(0); @@ -285,9 +292,72 @@ static inline void crash_kexec_stop_spus(void) } #endif /* CONFIG_SPU_BASE */ +/* + * 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); + +static unsigned long crash_shutdown_buf[JMP_BUF_LEN]; + +static int handle_fault(struct pt_regs *regs) +{ + longjmp(crash_shutdown_buf, 1); + return 0; +} + void default_machine_crash_shutdown(struct pt_regs *regs) { - unsigned int irq; + unsigned int i; + int (*old_handler)(struct pt_regs *regs); + /* * This function is only called after the system @@ -301,15 +371,36 @@ void default_machine_crash_shutdown(struct pt_regs *regs) */ hard_irq_disable(); - for_each_irq(irq) { - struct irq_desc *desc = irq_desc + irq; + for_each_irq(i) { + struct irq_desc *desc = irq_desc + i; if (desc->status & IRQ_INPROGRESS) - desc->chip->eoi(irq); + desc->chip->eoi(i); if (!(desc->status & IRQ_DISABLED)) - desc->chip->disable(irq); + desc->chip->disable(i); + } + + /* + * Call registered shutdown routines savely. Swap out + * __debugger_fault_handler, and replace on exit. + */ + old_handler = __debugger_fault_handler; + __debugger_fault_handler = handle_fault; + 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"); + } } + __debugger_fault_handler = old_handler; /* * Make a note of crashing cpu. Will be used in machine_kexec diff --git a/include/asm-powerpc/kexec.h b/include/asm-powerpc/kexec.h index b6f817b8ba3d..701857bc8e24 100644 --- a/include/asm-powerpc/kexec.h +++ b/include/asm-powerpc/kexec.h @@ -123,6 +123,9 @@ struct pt_regs; extern void default_machine_kexec(struct kimage *image); extern int default_machine_kexec_prepare(struct kimage *image); extern void default_machine_crash_shutdown(struct pt_regs *regs); +typedef void (*crash_shutdown_t)(void); +extern int crash_shutdown_register(crash_shutdown_t handler); +extern int crash_shutdown_unregister(crash_shutdown_t handler); extern void machine_kexec_simple(struct kimage *image); extern void crash_kexec_secondary(struct pt_regs *regs); |