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| author | H. Peter Anvin <hpa@linux.intel.com> | 2013-12-19 11:58:16 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2013-12-19 11:58:16 -0800 |
| commit | 7e98b71920464b8d15fa95c74366416cd3c88861 (patch) | |
| tree | e33e2af9f6a1813490aa686619de72c67b159e81 /arch/x86/include/asm | |
| parent | 16824255394f55adf31b9a96a9965d8c15bdac4c (diff) | |
| download | lwn-7e98b71920464b8d15fa95c74366416cd3c88861.tar.gz lwn-7e98b71920464b8d15fa95c74366416cd3c88861.zip | |
x86, idle: Use static_cpu_has() for CLFLUSH workaround, add barriers
Use static_cpu_has() to conditionalize the CLFLUSH workaround, and add
memory barriers around it since the documentation is explicit that
CLFLUSH is only ordered with respect to MFENCE.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Len Brown <len.brown@intel.com>
Link: http://lkml.kernel.org/r/CA%2B55aFzGxcML7j8CEvQPYzh0W81uVoAAVmGctMOUZ7CZ1yYd2A@mail.gmail.com
Diffstat (limited to 'arch/x86/include/asm')
| -rw-r--r-- | arch/x86/include/asm/mwait.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/include/asm/mwait.h b/arch/x86/include/asm/mwait.h index 361b02ef128c..19b71c439256 100644 --- a/arch/x86/include/asm/mwait.h +++ b/arch/x86/include/asm/mwait.h @@ -43,8 +43,11 @@ static inline void __mwait(unsigned long eax, unsigned long ecx) static inline void mwait_idle_with_hints(unsigned long eax, unsigned long ecx) { if (!current_set_polling_and_test()) { - if (this_cpu_has(X86_FEATURE_CLFLUSH_MONITOR)) + if (static_cpu_has(X86_FEATURE_CLFLUSH_MONITOR)) { + mb(); clflush((void *)¤t_thread_info()->flags); + mb(); + } __monitor((void *)¤t_thread_info()->flags, 0, 0); if (!need_resched()) |