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authorMark Langsdorf <mark.langsdorf@amd.com>2008-08-14 10:11:26 -0400
committerIngo Molnar <mingo@elte.hu>2008-08-15 08:04:30 -0400
commit394a15051c33f2b18e72f42283b36a9388fa414b (patch)
tree3e0b4acbd9e940758b184991d78bfe8f3a168050 /arch/x86/kernel/process_32.c
parentdcc984166870150709f0c645b521a47becd9a047 (diff)
x86: invalidate caches before going into suspend
When a CPU core is shut down, all of its caches need to be flushed to prevent stale data from causing errors if the core is resumed. Current Linux suspend code performs an assignment after the flush, which can add dirty data back to the cache.  On some AMD platforms, additional speculative reads have caused crashes on resume because of this dirty data. Relocate the cache flush to be the very last thing done before halting.  Tie into an assembly line so the compile will not reorder it.  Add some documentation explaining what is going on and why we're doing this. Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com> Acked-by: Mark Borden <mark.borden@amd.com> Acked-by: Michael Hohmuth <michael.hohmuth@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/process_32.c')
-rw-r--r--arch/x86/kernel/process_32.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 53bc653ed5ca..3b7a1ddcc0bc 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -95,7 +95,6 @@ static inline void play_dead(void)
95{ 95{
96 /* This must be done before dead CPU ack */ 96 /* This must be done before dead CPU ack */
97 cpu_exit_clear(); 97 cpu_exit_clear();
98 wbinvd();
99 mb(); 98 mb();
100 /* Ack it */ 99 /* Ack it */
101 __get_cpu_var(cpu_state) = CPU_DEAD; 100 __get_cpu_var(cpu_state) = CPU_DEAD;
@@ -104,8 +103,8 @@ static inline void play_dead(void)
104 * With physical CPU hotplug, we should halt the cpu 103 * With physical CPU hotplug, we should halt the cpu
105 */ 104 */
106 local_irq_disable(); 105 local_irq_disable();
107 while (1) 106 /* mask all interrupts, flush any and all caches, and halt */
108 halt(); 107 wbinvd_halt();
109} 108}
110#else 109#else
111static inline void play_dead(void) 110static inline void play_dead(void)