path: root/arch/x86/include/asm/irq_vectors.h
diff options
authorAndi Kleen <andi@firstfloor.org>2009-05-27 21:56:54 +0200
committerH. Peter Anvin <hpa@zytor.com>2009-06-03 14:44:05 -0700
commitccc3c3192ae78dd56dcdf5353fd1a9ef5f9a3e2b (patch)
tree65f380bd68bdd496f42ac8de88ccb74e340cc968 /arch/x86/include/asm/irq_vectors.h
parentbd19a5e6b73df276e1ccedf9059e9ee70c372d7d (diff)
x86, mce: implement bootstrapping for machine check wakeups
Machine checks support waking up the mcelog daemon quickly. The original wake up code for this was pretty ugly, relying on a idle notifier and a special process flag. The reason it did it this way is that the machine check handler is not subject to normal interrupt locking rules so it's not safe to call wake_up(). Instead it set a process flag and then either did the wakeup in the syscall return or in the idle notifier. This patch adds a new "bootstraping" method as replacement. The idea is that the handler checks if it's in a state where it is unsafe to call wake_up(). If it's safe it calls it directly. When it's not safe -- that is it interrupted in a critical section with interrupts disables -- it uses a new "self IPI" to trigger an IPI to its own CPU. This can be done safely because IPI triggers are atomic with some care. The IPI is raised once the interrupts are reenabled and can then safely call wake_up(). When APICs are disabled the event is just queued and will be picked up eventually by the next polling timer. I think that's a reasonable compromise, since it should only happen quite rarely. Contains fixes from Ying Huang. [ solve conflict on irqinit, make it work on 32bit (entry_arch.h) - HS ] Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/include/asm/irq_vectors.h')
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
index 8c46b851296..68f7cf84a33 100644
--- a/arch/x86/include/asm/irq_vectors.h
+++ b/arch/x86/include/asm/irq_vectors.h
@@ -118,6 +118,11 @@
+ * Self IPI vector for machine checks
+ */
+#define MCE_SELF_VECTOR 0xeb
* First APIC vector available to drivers: (vectors 0x30-0xee) we
* start at 0x31(0x41) to spread out vectors evenly between priority
* levels. (0x80 is the syscall vector)