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nds32: Fix vDSO clock_getres()

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clock_getres in the vDSO library has to preserve the same behaviour
of posix_get_hrtimer_res().

In particular, posix_get_hrtimer_res() does:
    sec = 0;
    ns = hrtimer_resolution;
and hrtimer_resolution depends on the enablement of the high
resolution timers that can happen either at compile or at run time.

Fix the nds32 vdso implementation of clock_getres keeping a copy of
hrtimer_resolution in vdso data and using that directly.

Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
This commit is contained in:
Vincenzo Frascino 2019-04-01 12:51:51 +01:00 committed by Greentime Hu
parent 63e07e2029
commit af9abd6598
3 changed files with 5 additions and 1 deletions
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1
arch/nds32/include/asm/vdso_datapage.h
View File

@ -20,6 +20,7 @@ struct vdso_data {
u32 xtime_clock_sec; /* CLOCK_REALTIME - seconds */
u32 cs_mult; /* clocksource multiplier */
u32 cs_shift; /* Cycle to nanosecond divisor (power of two) */
u32 hrtimer_res; /* hrtimer resolution */
u64 cs_cycle_last; /* last cycle value */
u64 cs_mask; /* clocksource mask */

1
arch/nds32/kernel/vdso.c
View File

@ -220,6 +220,7 @@ void update_vsyscall(struct timekeeper *tk)
vdso_data->xtime_coarse_sec = tk->xtime_sec;
vdso_data->xtime_coarse_nsec = tk->tkr_mono.xtime_nsec >>
tk->tkr_mono.shift;
vdso_data->hrtimer_res = hrtimer_resolution;
vdso_write_end(vdso_data);
}

4
arch/nds32/kernel/vdso/gettimeofday.c
View File

@ -208,6 +208,8 @@ static notrace int clock_getres_fallback(clockid_t _clk_id,
notrace int __vdso_clock_getres(clockid_t clk_id, struct timespec *res)
{
struct vdso_data *vdata = __get_datapage();
if (res == NULL)
return 0;
switch (clk_id) {
@ -215,7 +217,7 @@ notrace int __vdso_clock_getres(clockid_t clk_id, struct timespec *res)
case CLOCK_MONOTONIC:
case CLOCK_MONOTONIC_RAW:
res->tv_sec = 0;
res->tv_nsec = CLOCK_REALTIME_RES;
res->tv_nsec = vdata->hrtimer_res;
break;
case CLOCK_REALTIME_COARSE:
case CLOCK_MONOTONIC_COARSE: