diff options
Diffstat (limited to 'include/asm-x86/processor.h')
-rw-r--r-- | include/asm-x86/processor.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/include/asm-x86/processor.h b/include/asm-x86/processor.h index eb4bd8c0773..61c3d3005dc 100644 --- a/include/asm-x86/processor.h +++ b/include/asm-x86/processor.h | |||
@@ -746,6 +746,29 @@ extern unsigned long boot_option_idle_override; | |||
746 | extern unsigned long idle_halt; | 746 | extern unsigned long idle_halt; |
747 | extern unsigned long idle_nomwait; | 747 | extern unsigned long idle_nomwait; |
748 | 748 | ||
749 | /* | ||
750 | * on systems with caches, caches must be flashed as the absolute | ||
751 | * last instruction before going into a suspended halt. Otherwise, | ||
752 | * dirty data can linger in the cache and become stale on resume, | ||
753 | * leading to strange errors. | ||
754 | * | ||
755 | * perform a variety of operations to guarantee that the compiler | ||
756 | * will not reorder instructions. wbinvd itself is serializing | ||
757 | * so the processor will not reorder. | ||
758 | * | ||
759 | * Systems without cache can just go into halt. | ||
760 | */ | ||
761 | static inline void wbinvd_halt(void) | ||
762 | { | ||
763 | mb(); | ||
764 | /* check for clflush to determine if wbinvd is legal */ | ||
765 | if (cpu_has_clflush) | ||
766 | asm volatile("cli; wbinvd; 1: hlt; jmp 1b" : : : "memory"); | ||
767 | else | ||
768 | while (1) | ||
769 | halt(); | ||
770 | } | ||
771 | |||
749 | extern void enable_sep_cpu(void); | 772 | extern void enable_sep_cpu(void); |
750 | extern int sysenter_setup(void); | 773 | extern int sysenter_setup(void); |
751 | 774 | ||