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-rw-r--r--arch/powerpc/kernel/crash.c101
-rw-r--r--include/asm-powerpc/kexec.h3
2 files changed, 99 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/crash.c b/arch/powerpc/kernel/crash.c
index 77c749a1337..571132ed12c 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 b6f817b8ba3..701857bc8e2 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);