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authorMark Langsdorf <mark.langsdorf@amd.com>2008-08-14 09:11:26 -0500
committerIngo Molnar <mingo@elte.hu>2008-08-15 14:04:30 +0200
commit394a15051c33f2b18e72f42283b36a9388fa414b (patch)
tree3e0b4acbd9e940758b184991d78bfe8f3a168050 /arch/x86/kernel
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')
-rw-r--r--arch/x86/kernel/process_32.c5
-rw-r--r--arch/x86/kernel/process_64.c5
2 files changed, 4 insertions, 6 deletions
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 53bc653ed5c..3b7a1ddcc0b 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)
{
/* This must be done before dead CPU ack */
cpu_exit_clear();
- wbinvd();
mb();
/* Ack it */
__get_cpu_var(cpu_state) = CPU_DEAD;
@@ -104,8 +103,8 @@ static inline void play_dead(void)
* With physical CPU hotplug, we should halt the cpu
*/
local_irq_disable();
- while (1)
- halt();
+ /* mask all interrupts, flush any and all caches, and halt */
+ wbinvd_halt();
}
#else
static inline void play_dead(void)
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 3fb62a7d9a1..71553b664e2 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -93,14 +93,13 @@ DECLARE_PER_CPU(int, cpu_state);
static inline void play_dead(void)
{
idle_task_exit();
- wbinvd();
mb();
/* Ack it */
__get_cpu_var(cpu_state) = CPU_DEAD;
local_irq_disable();
- while (1)
- halt();
+ /* mask all interrupts, flush any and all caches, and halt */
+ wbinvd_halt();
}
#else
static inline void play_dead(void)