[PATCH 2/2] Enter 2nd kernel with BSP

From: HATAYAMA Daisuke
Date: Sun Apr 15 2012 - 22:22:08 EST


Split logic into BSP's and AP's: BSP waits for AP halting.

Don't remove variable crashing_cpu for debugging use; useful for
determining one what CPU crash happens.

Signed-off-by: HATAYAMA Daisuke <d.hatayama@xxxxxxxxxxxxxx>
---

arch/x86/kernel/crash.c | 15 ++++++++++++++-
arch/x86/kernel/reboot.c | 16 ++++++----------
2 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 13ad899..c5c19fa 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -83,9 +83,14 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
* In practice this means shooting down the other cpus in
* an SMP system.
*/
+
+ int cpu;
+
/* The kernel is broken so disable interrupts */
local_irq_disable();

+ crash_ipi_init();
+
kdump_nmi_shootdown_cpus();

/* Booting kdump kernel with VMX or SVM enabled won't work,
@@ -102,5 +107,13 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
#ifdef CONFIG_HPET_TIMER
hpet_disable();
#endif
- crash_save_cpu(regs, safe_smp_processor_id());
+ cpu = safe_smp_processor_id();
+ crash_save_cpu(regs, cpu);
+
+ if (cpu_physical_id(cpu) == boot_cpu_physical_apicid) {
+ crash_ipi_wait_for_APs();
+ return;
+ }
+
+ crash_ipi_dec_and_halt();
}
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 6dd77a8..90354f9 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -7,6 +7,7 @@
#include <linux/sched.h>
#include <linux/tboot.h>
#include <linux/delay.h>
+#include <linux/kexec.h>
#include <acpi/reboot.h>
#include <asm/io.h>
#include <asm/apic.h>
@@ -800,16 +801,15 @@ static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)

cpu = raw_smp_processor_id();

- /* Don't do anything if this handler is invoked on crashing cpu.
- * Otherwise, system will completely hang. Crashing cpu can get
- * an NMI if system was initially booted with nmi_watchdog parameter.
- */
- if (cpu == crashing_cpu)
- return NMI_HANDLED;
local_irq_disable();

shootdown_callback(cpu, regs);

+ if (cpu_physical_id(cpu) == boot_cpu_physical_apicid) {
+ crash_ipi_wait_for_APs();
+ machine_kexec(kexec_crash_image);
+ }
+
crash_ipi_dec_and_halt();

return NMI_HANDLED;
@@ -835,8 +835,6 @@ void nmi_shootdown_cpus(nmi_shootdown_cb callback)

shootdown_callback = callback;

- crash_ipi_init();
-
/* Would it be better to replace the trap vector here? */
if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
NMI_FLAG_FIRST, "crash"))
@@ -848,8 +846,6 @@ void nmi_shootdown_cpus(nmi_shootdown_cb callback)

smp_send_nmi_allbutself();

- crash_ipi_wait_for_APs();
-
/* Leave the nmi callback set */
}
#else /* !CONFIG_SMP */

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