Commit e77deacb authored by Keith Owens's avatar Keith Owens Committed by Linus Torvalds

[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: default avatarKeith Owens <kaos@sgi.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 704fc59e
......@@ -78,22 +78,29 @@ static void flat_send_IPI_mask(cpumask_t cpumask, int vector)
static void flat_send_IPI_allbutself(int vector)
{
#ifndef CONFIG_HOTPLUG_CPU
if (((num_online_cpus()) - 1) >= 1)
__send_IPI_shortcut(APIC_DEST_ALLBUT, vector,APIC_DEST_LOGICAL);
#ifdef CONFIG_HOTPLUG_CPU
int hotplug = 1;
#else
cpumask_t allbutme = cpu_online_map;
int hotplug = 0;
#endif
if (hotplug || vector == NMI_VECTOR) {
cpumask_t allbutme = cpu_online_map;
cpu_clear(smp_processor_id(), allbutme);
cpu_clear(smp_processor_id(), allbutme);
if (!cpus_empty(allbutme))
flat_send_IPI_mask(allbutme, vector);
#endif
if (!cpus_empty(allbutme))
flat_send_IPI_mask(allbutme, vector);
} else if (num_online_cpus() > 1) {
__send_IPI_shortcut(APIC_DEST_ALLBUT, vector,APIC_DEST_LOGICAL);
}
}
static void flat_send_IPI_all(int vector)
{
__send_IPI_shortcut(APIC_DEST_ALLINC, vector, APIC_DEST_LOGICAL);
if (vector == NMI_VECTOR)
flat_send_IPI_mask(cpu_online_map, vector);
else
__send_IPI_shortcut(APIC_DEST_ALLINC, vector, APIC_DEST_LOGICAL);
}
static int flat_apic_id_registered(void)
......
#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 send_IPI_mask(cpumask_t mask, int vector)
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_allbutself(int vector)
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);
......
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