[PATCH 3.12 074/116] x86/apic: Disable I/O APIC before shutdown of the local APIC
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2013-11-27 01:22:17
Also in:
lkml
3.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Fenghua Yu <redacted> commit 522e66464467543c0d88d023336eec4df03ad40b upstream. In reboot and crash path, when we shut down the local APIC, the I/O APIC is still active. This may cause issues because external interrupts can still come in and disturb the local APIC during shutdown process. To quiet external interrupts, disable I/O APIC before shutdown local APIC. Signed-off-by: Fenghua Yu <redacted> Link: http://lkml.kernel.org/r/1382578212-4677-1-git-send-email-fenghua.yu@intel.com [ I suppose the 'issue' is a hang during shutdown. It's a fine change nevertheless. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- arch/x86/kernel/crash.c | 2 +- arch/x86/kernel/reboot.c | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-)
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c@@ -127,12 +127,12 @@ void native_machine_crash_shutdown(struc cpu_emergency_vmxoff(); cpu_emergency_svm_disable(); - lapic_shutdown(); #ifdef CONFIG_X86_IO_APIC /* Prevent crash_kexec() from deadlocking on ioapic_lock. */ ioapic_zap_locks(); disable_IO_APIC(); #endif + lapic_shutdown(); #ifdef CONFIG_HPET_TIMER hpet_disable(); #endif --- a/arch/x86/kernel/reboot.c +++ b/arch/x86/kernel/reboot.c
@@ -550,6 +550,10 @@ static void native_machine_emergency_res void native_machine_shutdown(void) { /* Stop the cpus and apics */ +#ifdef CONFIG_X86_IO_APIC + disable_IO_APIC(); +#endif + #ifdef CONFIG_SMP /* * Stop all of the others. Also disable the local irq to
@@ -562,10 +566,6 @@ void native_machine_shutdown(void) lapic_shutdown(); -#ifdef CONFIG_X86_IO_APIC - disable_IO_APIC(); -#endif - #ifdef CONFIG_HPET_TIMER hpet_disable(); #endif