From c6e5ca35c4685cd920b1d5279dbc9f4483d7dfd4 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Thu, 25 Jun 2015 18:43:55 +0200 Subject: [PATCH] x86/asm/tsc: Inline native_read_tsc() and remove __native_read_tsc() In the following commit: cdc7957d1954 ("x86: move native_read_tsc() offline") ... native_read_tsc() was moved out of line, presumably for some now-obsolete vDSO-related reason. Undo it. The entire rdtsc, shl, or sequence is only 11 bytes, and calls via rdtscl() and similar helpers were already inlined. Signed-off-by: Andy Lutomirski Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Huang Rui Cc: John Stultz Cc: Len Brown Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Ralf Baechle Cc: Thomas Gleixner Cc: kvm ML Link: http://lkml.kernel.org/r/d05ffe2aaf8468ca475ebc00efad7b2fa174af19.1434501121.git.luto@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/entry/vdso/vclock_gettime.c | 2 +- arch/x86/include/asm/msr.h | 8 +++----- arch/x86/include/asm/pvclock.h | 2 +- arch/x86/include/asm/stackprotector.h | 2 +- arch/x86/include/asm/tsc.h | 2 +- arch/x86/kernel/apb_timer.c | 4 ++-- arch/x86/kernel/tsc.c | 6 ------ 7 files changed, 9 insertions(+), 17 deletions(-) diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c index 9793322..972b488 100644 --- a/arch/x86/entry/vdso/vclock_gettime.c +++ b/arch/x86/entry/vdso/vclock_gettime.c @@ -186,7 +186,7 @@ notrace static cycle_t vread_tsc(void) * but no one has ever seen it happen. */ rdtsc_barrier(); - ret = (cycle_t)__native_read_tsc(); + ret = (cycle_t)native_read_tsc(); last = gtod->cycle_last; diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h index e6a707e..8871147 100644 --- a/arch/x86/include/asm/msr.h +++ b/arch/x86/include/asm/msr.h @@ -106,12 +106,10 @@ notrace static inline int native_write_msr_safe(unsigned int msr, return err; } -extern unsigned long long native_read_tsc(void); - 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) +static __always_inline unsigned long long native_read_tsc(void) { DECLARE_ARGS(val, low, high); @@ -181,10 +179,10 @@ static inline int rdmsrl_safe(unsigned msr, unsigned long long *p) } #define rdtscl(low) \ - ((low) = (u32)__native_read_tsc()) + ((low) = (u32)native_read_tsc()) #define rdtscll(val) \ - ((val) = __native_read_tsc()) + ((val) = native_read_tsc()) #define rdpmc(counter, low, high) \ do { \ diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h index 628954c..2bd69d6 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 = native_read_tsc() - 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 c2e00bb2..bc5fa2a 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 = native_read_tsc(); 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 94605c0..fd11128 100644 --- a/arch/x86/include/asm/tsc.h +++ b/arch/x86/include/asm/tsc.h @@ -42,7 +42,7 @@ static __always_inline cycles_t vget_cycles(void) if (!cpu_has_tsc) return 0; #endif - return (cycles_t)__native_read_tsc(); + return (cycles_t)native_read_tsc(); } extern void tsc_init(void); diff --git a/arch/x86/kernel/apb_timer.c b/arch/x86/kernel/apb_timer.c index ede92c3..9fe111c 100644 --- a/arch/x86/kernel/apb_timer.c +++ b/arch/x86/kernel/apb_timer.c @@ -390,13 +390,13 @@ unsigned long apbt_quick_calibrate(void) old = dw_apb_clocksource_read(clocksource_apbt); old += loop; - t1 = __native_read_tsc(); + t1 = native_read_tsc(); do { new = dw_apb_clocksource_read(clocksource_apbt); } while (new < old); - t2 = __native_read_tsc(); + t2 = native_read_tsc(); shift = 5; if (unlikely(loop >> shift == 0)) { diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 5054497..e7710cd 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -308,12 +308,6 @@ unsigned long long sched_clock(void) __attribute__((alias("native_sched_clock"))); #endif -unsigned long long native_read_tsc(void) -{ - return __native_read_tsc(); -} -EXPORT_SYMBOL(native_read_tsc); - int check_tsc_unstable(void) { return tsc_unstable; -- 2.7.4