lkml.org 
[lkml]   [2019]   [Jun]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v7 23/25] x86: Add clock_getres entry point
    Date
    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
    --
    2.21.0
    \
     
     \ /
      Last update: 2019-06-21 11:55    [W:4.132 / U:0.384 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site