[PATCH 4/5] nds32: Fix vDSO clock_getres()
Vincenzo Frascino
vincenzo.frascino at arm.com
Mon Apr 1 22:51:51 AEDT 2019
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 at gmail.com>
Cc: Vincent Chen <deanbo422 at gmail.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino at arm.com>
---
arch/nds32/include/asm/vdso_datapage.h | 1 +
arch/nds32/kernel/vdso.c | 1 +
arch/nds32/kernel/vdso/gettimeofday.c | 4 +++-
3 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/nds32/include/asm/vdso_datapage.h b/arch/nds32/include/asm/vdso_datapage.h
index 79db5a12ca5e..34d80548297f 100644
--- a/arch/nds32/include/asm/vdso_datapage.h
+++ b/arch/nds32/include/asm/vdso_datapage.h
@@ -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 */
diff --git a/arch/nds32/kernel/vdso.c b/arch/nds32/kernel/vdso.c
index 016f15891f6d..90bcae6f8554 100644
--- a/arch/nds32/kernel/vdso.c
+++ b/arch/nds32/kernel/vdso.c
@@ -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);
}
diff --git a/arch/nds32/kernel/vdso/gettimeofday.c b/arch/nds32/kernel/vdso/gettimeofday.c
index 038721af40e3..b02581891c33 100644
--- a/arch/nds32/kernel/vdso/gettimeofday.c
+++ b/arch/nds32/kernel/vdso/gettimeofday.c
@@ -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:
--
2.21.0
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