1 files changed, 48 insertions, 31 deletions

diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
index 80f54723cf6d..ef5c2d25ec39 100644
--- a/arch/powerpc/kexec/crash.c
+++ b/arch/powerpc/kexec/crash.c
@@ -40,6 +40,14 @@
 #define REAL_MODE_TIMEOUT	10000
 
 static int time_to_dump;
+
+/*
+ * In case of system reset, secondary CPUs enter crash_kexec_secondary with out
+ * having to send an IPI explicitly. So, indicate if the crash is via
+ * system reset to avoid sending another IPI.
+ */
+static int is_via_system_reset;
+
 /*
  * 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
@@ -101,7 +109,7 @@ void crash_ipi_callback(struct pt_regs *regs)
 	/* NOTREACHED */
 }
 
-static void crash_kexec_prepare_cpus(int cpu)
+static void crash_kexec_prepare_cpus(void)
 {
 	unsigned int msecs;
 	volatile unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
@@ -113,7 +121,15 @@ static void crash_kexec_prepare_cpus(int cpu)
 	if (crash_wake_offline)
 		ncpus = num_present_cpus() - 1;
 
-	crash_send_ipi(crash_ipi_callback);
+	/*
+	 * If we came in via system reset, secondaries enter via crash_kexec_secondary().
+	 * So, wait a while for the secondary CPUs to enter for that case.
+	 * Else, send IPI to all other CPUs.
+	 */
+	if (is_via_system_reset)
+		mdelay(PRIMARY_TIMEOUT);
+	else
+		crash_send_ipi(crash_ipi_callback);
 	smp_wmb();
 
 again:
@@ -202,7 +218,7 @@ void crash_kexec_secondary(struct pt_regs *regs)
 
 #else	/* ! CONFIG_SMP */
 
-static void crash_kexec_prepare_cpus(int cpu)
+static void crash_kexec_prepare_cpus(void)
 {
 	/*
 	 * move the secondaries to us so that we can copy
@@ -248,6 +264,32 @@ noinstr static void __maybe_unused crash_kexec_wait_realmode(int cpu)
 static inline void crash_kexec_wait_realmode(int cpu) {}
 #endif	/* CONFIG_SMP && CONFIG_PPC64 */
 
+void crash_kexec_prepare(void)
+{
+	/* Avoid hardlocking with irresponsive CPU holding logbuf_lock */
+	printk_deferred_enter();
+
+	/*
+	 * 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();
+
+	crash_kexec_prepare_cpus();
+}
+
 /*
  * Register a function to be called on shutdown.  Only use this if you
  * can't reset your device in the second kernel.
@@ -308,38 +350,13 @@ EXPORT_SYMBOL(crash_shutdown_unregister);
 
 void default_machine_crash_shutdown(struct pt_regs *regs)
 {
-	unsigned int i;
+	volatile unsigned int i;
 	int (*old_handler)(struct pt_regs *regs);
 
-	/* Avoid hardlocking with irresponsive CPU holding logbuf_lock */
-	printk_deferred_enter();
-
-	/*
-	 * 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) == INTERRUPT_SYSTEM_RESET)
-		mdelay(PRIMARY_TIMEOUT);
+		is_via_system_reset = 1;
 
-	crash_kexec_prepare_cpus(crashing_cpu);
+	crash_smp_send_stop();
 
 	crash_save_cpu(regs, crashing_cpu);