diff options
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/msr.h | 11 | ||||
| -rw-r--r-- | arch/x86/include/asm/pvclock.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/stackprotector.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/tsc.h | 2 |
4 files changed, 13 insertions, 4 deletions
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h index c89ed6ceed02..ff0c120dafe5 100644 --- a/arch/x86/include/asm/msr.h +++ b/arch/x86/include/asm/msr.h @@ -109,7 +109,16 @@ notrace static inline int native_write_msr_safe(unsigned int msr, extern int rdmsr_safe_regs(u32 regs[8]); extern int wrmsr_safe_regs(u32 regs[8]); -static __always_inline unsigned long long native_read_tsc(void) +/** + * rdtsc() - returns the current TSC without ordering constraints + * + * rdtsc() returns the result of RDTSC as a 64-bit integer. The + * only ordering constraint it supplies is the ordering implied by + * "asm volatile": it will put the RDTSC in the place you expect. The + * CPU can and will speculatively execute that RDTSC, though, so the + * results can be non-monotonic if compared on different CPUs. + */ +static __always_inline unsigned long long rdtsc(void) { DECLARE_ARGS(val, low, high); diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h index 2bd69d62c623..5c490db62e32 100644 --- a/arch/x86/include/asm/pvclock.h +++ b/arch/x86/include/asm/pvclock.h @@ -62,7 +62,7 @@ static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift) static __always_inline u64 pvclock_get_nsec_offset(const struct pvclock_vcpu_time_info *src) { - u64 delta = native_read_tsc() - src->tsc_timestamp; + u64 delta = rdtsc() - src->tsc_timestamp; return pvclock_scale_delta(delta, src->tsc_to_system_mul, src->tsc_shift); } diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h index bc5fa2af112e..58505f01962f 100644 --- a/arch/x86/include/asm/stackprotector.h +++ b/arch/x86/include/asm/stackprotector.h @@ -72,7 +72,7 @@ static __always_inline void boot_init_stack_canary(void) * on during the bootup the random pool has true entropy too. */ get_random_bytes(&canary, sizeof(canary)); - tsc = native_read_tsc(); + tsc = rdtsc(); canary += tsc + (tsc << 32UL); current->stack_canary = canary; diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h index b4883902948b..3df7675debcf 100644 --- a/arch/x86/include/asm/tsc.h +++ b/arch/x86/include/asm/tsc.h @@ -26,7 +26,7 @@ static inline cycles_t get_cycles(void) return 0; #endif - return native_read_tsc(); + return rdtsc(); } extern void tsc_init(void); |