[PATCH] x86_64: Avoid broadcasting NMI IPIs
On some i386/x86_64 systems, sending an NMI IPI as a broadcast will
reset the system. This seems to be a BIOS bug which affects machines
where one or more cpus are not under OS control. It occurs on HT
systems with a version of the OS that is not compiled without HT
support. It also occurs when a system is booted with max_cpus=n where
2 <= n < cpus known to the BIOS. The fix is to always send NMI IPI as
a mask instead of as a broadcast.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-i386/mach-default/mach_ipi.h b/include/asm-i386/mach-default/mach_ipi.h
index a1d0072..0dba244 100644
--- a/include/asm-i386/mach-default/mach_ipi.h
+++ b/include/asm-i386/mach-default/mach_ipi.h
@@ -1,6 +1,9 @@
#ifndef __ASM_MACH_IPI_H
#define __ASM_MACH_IPI_H
+/* Avoid include hell */
+#define NMI_VECTOR 0x02
+
void send_IPI_mask_bitmask(cpumask_t mask, int vector);
void __send_IPI_shortcut(unsigned int shortcut, int vector);
@@ -13,7 +16,7 @@
static inline void __local_send_IPI_allbutself(int vector)
{
- if (no_broadcast) {
+ if (no_broadcast || vector == NMI_VECTOR) {
cpumask_t mask = cpu_online_map;
cpu_clear(smp_processor_id(), mask);
@@ -24,7 +27,7 @@
static inline void __local_send_IPI_all(int vector)
{
- if (no_broadcast)
+ if (no_broadcast || vector == NMI_VECTOR)
send_IPI_mask(cpu_online_map, vector);
else
__send_IPI_shortcut(APIC_DEST_ALLINC, vector);