diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/x86/vdso/vclock_gettime.c')
| -rw-r--r-- | ANDROID_3.4.5/arch/x86/vdso/vclock_gettime.c | 217 |
1 files changed, 0 insertions, 217 deletions
diff --git a/ANDROID_3.4.5/arch/x86/vdso/vclock_gettime.c b/ANDROID_3.4.5/arch/x86/vdso/vclock_gettime.c deleted file mode 100644 index 885eff49..00000000 --- a/ANDROID_3.4.5/arch/x86/vdso/vclock_gettime.c +++ /dev/null @@ -1,217 +0,0 @@ -/* - * Copyright 2006 Andi Kleen, SUSE Labs. - * Subject to the GNU Public License, v.2 - * - * Fast user context implementation of clock_gettime, gettimeofday, and time. - * - * The code should have no internal unresolved relocations. - * Check with readelf after changing. - */ - -/* Disable profiling for userspace code: */ -#define DISABLE_BRANCH_PROFILING - -#include <linux/kernel.h> -#include <linux/posix-timers.h> -#include <linux/time.h> -#include <linux/string.h> -#include <asm/vsyscall.h> -#include <asm/fixmap.h> -#include <asm/vgtod.h> -#include <asm/timex.h> -#include <asm/hpet.h> -#include <asm/unistd.h> -#include <asm/io.h> - -#define gtod (&VVAR(vsyscall_gtod_data)) - -notrace static cycle_t vread_tsc(void) -{ - cycle_t ret; - u64 last; - - /* - * Empirically, a fence (of type that depends on the CPU) - * before rdtsc is enough to ensure that rdtsc is ordered - * with respect to loads. The various CPU manuals are unclear - * as to whether rdtsc can be reordered with later loads, - * but no one has ever seen it happen. - */ - rdtsc_barrier(); - ret = (cycle_t)vget_cycles(); - - last = VVAR(vsyscall_gtod_data).clock.cycle_last; - - if (likely(ret >= last)) - return ret; - - /* - * GCC likes to generate cmov here, but this branch is extremely - * predictable (it's just a funciton of time and the likely is - * very likely) and there's a data dependence, so force GCC - * to generate a branch instead. I don't barrier() because - * we don't actually need a barrier, and if this function - * ever gets inlined it will generate worse code. - */ - asm volatile (""); - return last; -} - -static notrace cycle_t vread_hpet(void) -{ - return readl((const void __iomem *)fix_to_virt(VSYSCALL_HPET) + 0xf0); -} - -notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) -{ - long ret; - asm("syscall" : "=a" (ret) : - "0" (__NR_clock_gettime),"D" (clock), "S" (ts) : "memory"); - return ret; -} - -notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz) -{ - long ret; - - asm("syscall" : "=a" (ret) : - "0" (__NR_gettimeofday), "D" (tv), "S" (tz) : "memory"); - return ret; -} - - -notrace static inline long vgetns(void) -{ - long v; - cycles_t cycles; - if (gtod->clock.vclock_mode == VCLOCK_TSC) - cycles = vread_tsc(); - else if (gtod->clock.vclock_mode == VCLOCK_HPET) - cycles = vread_hpet(); - else - return 0; - v = (cycles - gtod->clock.cycle_last) & gtod->clock.mask; - return (v * gtod->clock.mult) >> gtod->clock.shift; -} - -/* Code size doesn't matter (vdso is 4k anyway) and this is faster. */ -notrace static int __always_inline do_realtime(struct timespec *ts) -{ - unsigned long seq, ns; - int mode; - - do { - seq = read_seqcount_begin(>od->seq); - mode = gtod->clock.vclock_mode; - ts->tv_sec = gtod->wall_time_sec; - ts->tv_nsec = gtod->wall_time_nsec; - ns = vgetns(); - } while (unlikely(read_seqcount_retry(>od->seq, seq))); - - timespec_add_ns(ts, ns); - return mode; -} - -notrace static int do_monotonic(struct timespec *ts) -{ - unsigned long seq, ns; - int mode; - - do { - seq = read_seqcount_begin(>od->seq); - mode = gtod->clock.vclock_mode; - ts->tv_sec = gtod->monotonic_time_sec; - ts->tv_nsec = gtod->monotonic_time_nsec; - ns = vgetns(); - } while (unlikely(read_seqcount_retry(>od->seq, seq))); - timespec_add_ns(ts, ns); - - return mode; -} - -notrace static int do_realtime_coarse(struct timespec *ts) -{ - unsigned long seq; - do { - seq = read_seqcount_begin(>od->seq); - ts->tv_sec = gtod->wall_time_coarse.tv_sec; - ts->tv_nsec = gtod->wall_time_coarse.tv_nsec; - } while (unlikely(read_seqcount_retry(>od->seq, seq))); - return 0; -} - -notrace static int do_monotonic_coarse(struct timespec *ts) -{ - unsigned long seq; - do { - seq = read_seqcount_begin(>od->seq); - ts->tv_sec = gtod->monotonic_time_coarse.tv_sec; - ts->tv_nsec = gtod->monotonic_time_coarse.tv_nsec; - } while (unlikely(read_seqcount_retry(>od->seq, seq))); - - return 0; -} - -notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) -{ - int ret = VCLOCK_NONE; - - switch (clock) { - case CLOCK_REALTIME: - ret = do_realtime(ts); - break; - case CLOCK_MONOTONIC: - ret = do_monotonic(ts); - break; - case CLOCK_REALTIME_COARSE: - return do_realtime_coarse(ts); - case CLOCK_MONOTONIC_COARSE: - return do_monotonic_coarse(ts); - } - - if (ret == VCLOCK_NONE) - return vdso_fallback_gettime(clock, ts); - return 0; -} -int clock_gettime(clockid_t, struct timespec *) - __attribute__((weak, alias("__vdso_clock_gettime"))); - -notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz) -{ - long ret = VCLOCK_NONE; - - if (likely(tv != NULL)) { - BUILD_BUG_ON(offsetof(struct timeval, tv_usec) != - offsetof(struct timespec, tv_nsec) || - sizeof(*tv) != sizeof(struct timespec)); - ret = do_realtime((struct timespec *)tv); - tv->tv_usec /= 1000; - } - if (unlikely(tz != NULL)) { - /* Avoid memcpy. Some old compilers fail to inline it */ - tz->tz_minuteswest = gtod->sys_tz.tz_minuteswest; - tz->tz_dsttime = gtod->sys_tz.tz_dsttime; - } - - if (ret == VCLOCK_NONE) - return vdso_fallback_gtod(tv, tz); - return 0; -} -int gettimeofday(struct timeval *, struct timezone *) - __attribute__((weak, alias("__vdso_gettimeofday"))); - -/* - * This will break when the xtime seconds get inaccurate, but that is - * unlikely - */ -notrace time_t __vdso_time(time_t *t) -{ - /* This is atomic on x86_64 so we don't need any locks. */ - time_t result = ACCESS_ONCE(VVAR(vsyscall_gtod_data).wall_time_sec); - - if (t) - *t = result; - return result; -} -int time(time_t *t) - __attribute__((weak, alias("__vdso_time"))); |