The generic vDSO library provides an implementation of clock_getres() that can be leveraged by each architecture.
Add clock_getres() entry point on x86.
Cc: Thomas Gleixner tglx@linutronix.de Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- arch/x86/entry/vdso/vclock_gettime.c | 17 ++++++++++++++ arch/x86/entry/vdso/vdso.lds.S | 2 ++ arch/x86/entry/vdso/vdso32/vdso32.lds.S | 1 + arch/x86/include/asm/vdso/gettimeofday.h | 30 ++++++++++++++++++++++++ 4 files changed, 50 insertions(+)
diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c index 4a7ef4ca4f52..de9212a4833e 100644 --- a/arch/x86/entry/vdso/vclock_gettime.c +++ b/arch/x86/entry/vdso/vclock_gettime.c @@ -36,6 +36,7 @@ time_t time(time_t *t) #if defined(CONFIG_X86_64) && !defined(BUILD_VDSO32_64) /* both 64-bit and x32 use these */ extern int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts); +extern int __vdso_clock_getres(clockid_t clock, struct __kernel_timespec *res);
int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts) { @@ -44,9 +45,18 @@ int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts) int clock_gettime(clockid_t, struct __kernel_timespec *) __attribute__((weak, alias("__vdso_clock_gettime")));
+int __vdso_clock_getres(clockid_t clock, + struct __kernel_timespec *res) +{ + return __cvdso_clock_getres(clock, res); +} +int clock_getres(clockid_t, struct __kernel_timespec *) + __attribute__((weak, alias("__vdso_clock_getres"))); + #else /* i386 only */ extern int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts); +extern int __vdso_clock_getres(clockid_t clock, struct old_timespec32 *res);
int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts) { @@ -55,4 +65,11 @@ int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts) int clock_gettime(clockid_t, struct old_timespec32 *) __attribute__((weak, alias("__vdso_clock_gettime")));
+int __vdso_clock_getres(clockid_t clock, + struct old_timespec32 *res) +{ + return __cvdso_clock_getres_time32(clock, res); +} +int clock_getres(clockid_t, struct old_timespec32 *) + __attribute__((weak, alias("__vdso_clock_getres"))); #endif diff --git a/arch/x86/entry/vdso/vdso.lds.S b/arch/x86/entry/vdso/vdso.lds.S index d3a2dce4cfa9..36b644e16272 100644 --- a/arch/x86/entry/vdso/vdso.lds.S +++ b/arch/x86/entry/vdso/vdso.lds.S @@ -25,6 +25,8 @@ VERSION { __vdso_getcpu; time; __vdso_time; + clock_getres; + __vdso_clock_getres; local: *; }; } diff --git a/arch/x86/entry/vdso/vdso32/vdso32.lds.S b/arch/x86/entry/vdso/vdso32/vdso32.lds.S index 422764a81d32..991b26cc855b 100644 --- a/arch/x86/entry/vdso/vdso32/vdso32.lds.S +++ b/arch/x86/entry/vdso/vdso32/vdso32.lds.S @@ -26,6 +26,7 @@ VERSION __vdso_clock_gettime; __vdso_gettimeofday; __vdso_time; + __vdso_clock_getres; };
LINUX_2.5 { diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h index a274d4fea7a5..df8c8dfadfa7 100644 --- a/arch/x86/include/asm/vdso/gettimeofday.h +++ b/arch/x86/include/asm/vdso/gettimeofday.h @@ -24,6 +24,8 @@
#define VDSO_HAS_TIME 1
+#define VDSO_HAS_CLOCK_GETRES 1 + #ifdef CONFIG_PARAVIRT_CLOCK extern u8 pvclock_page[PAGE_SIZE] __attribute__((visibility("hidden"))); @@ -57,6 +59,17 @@ static __always_inline long gettimeofday_fallback( return ret; }
+static __always_inline long clock_getres_fallback( + clockid_t _clkid, + struct __kernel_timespec *_ts) +{ + long ret; + asm ("syscall" : "=a" (ret), "=m" (*_ts) : + "0" (__NR_clock_getres), "D" (_clkid), "S" (_ts) : + "rcx", "r11"); + return ret; +} + #else
static __always_inline long clock_gettime_fallback( @@ -92,6 +105,23 @@ static __always_inline long gettimeofday_fallback( return ret; }
+static __always_inline long clock_getres_fallback( + clockid_t _clkid, + struct __kernel_timespec *_ts) +{ + long ret; + + asm ( + "mov %%ebx, %%edx \n" + "mov %[clock], %%ebx \n" + "call __kernel_vsyscall \n" + "mov %%edx, %%ebx \n" + : "=a" (ret), "=m" (*_ts) + : "0" (__NR_clock_getres_time64), [clock] "g" (_clkid), "c" (_ts) + : "edx"); + return ret; +} + #endif
#ifdef CONFIG_PARAVIRT_CLOCK