mirror of
https://github.com/torvalds/linux.git
synced 2024-12-26 04:42:12 +00:00
9b13a93df2
X86_FEATURE_FXSAVE_LEAK, X86_FEATURE_11AP and X86_FEATURE_CLFLUSH_MONITOR are not really features but synthetic bits we use for applying different bug workarounds. Call them what they really are, and make sure they get the proper cross-CPU behavior (OR rather than AND). Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1403042783-23278-1-git-send-email-bp@alien8.de Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
60 lines
1.6 KiB
C
60 lines
1.6 KiB
C
#ifndef _ASM_X86_MWAIT_H
|
|
#define _ASM_X86_MWAIT_H
|
|
|
|
#include <linux/sched.h>
|
|
|
|
#define MWAIT_SUBSTATE_MASK 0xf
|
|
#define MWAIT_CSTATE_MASK 0xf
|
|
#define MWAIT_SUBSTATE_SIZE 4
|
|
#define MWAIT_HINT2CSTATE(hint) (((hint) >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK)
|
|
#define MWAIT_HINT2SUBSTATE(hint) ((hint) & MWAIT_CSTATE_MASK)
|
|
|
|
#define CPUID_MWAIT_LEAF 5
|
|
#define CPUID5_ECX_EXTENSIONS_SUPPORTED 0x1
|
|
#define CPUID5_ECX_INTERRUPT_BREAK 0x2
|
|
|
|
#define MWAIT_ECX_INTERRUPT_BREAK 0x1
|
|
|
|
static inline void __monitor(const void *eax, unsigned long ecx,
|
|
unsigned long edx)
|
|
{
|
|
/* "monitor %eax, %ecx, %edx;" */
|
|
asm volatile(".byte 0x0f, 0x01, 0xc8;"
|
|
:: "a" (eax), "c" (ecx), "d"(edx));
|
|
}
|
|
|
|
static inline void __mwait(unsigned long eax, unsigned long ecx)
|
|
{
|
|
/* "mwait %eax, %ecx;" */
|
|
asm volatile(".byte 0x0f, 0x01, 0xc9;"
|
|
:: "a" (eax), "c" (ecx));
|
|
}
|
|
|
|
/*
|
|
* This uses new MONITOR/MWAIT instructions on P4 processors with PNI,
|
|
* which can obviate IPI to trigger checking of need_resched.
|
|
* We execute MONITOR against need_resched and enter optimized wait state
|
|
* through MWAIT. Whenever someone changes need_resched, we would be woken
|
|
* up from MWAIT (without an IPI).
|
|
*
|
|
* New with Core Duo processors, MWAIT can take some hints based on CPU
|
|
* capability.
|
|
*/
|
|
static inline void mwait_idle_with_hints(unsigned long eax, unsigned long ecx)
|
|
{
|
|
if (!current_set_polling_and_test()) {
|
|
if (static_cpu_has_bug(X86_BUG_CLFLUSH_MONITOR)) {
|
|
mb();
|
|
clflush((void *)¤t_thread_info()->flags);
|
|
mb();
|
|
}
|
|
|
|
__monitor((void *)¤t_thread_info()->flags, 0, 0);
|
|
if (!need_resched())
|
|
__mwait(eax, ecx);
|
|
}
|
|
current_clr_polling();
|
|
}
|
|
|
|
#endif /* _ASM_X86_MWAIT_H */
|