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path: root/arch/tile/kernel/vdso/vgettimeofday.c
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Diffstat (limited to 'arch/tile/kernel/vdso/vgettimeofday.c')
-rw-r--r--arch/tile/kernel/vdso/vgettimeofday.c176
1 files changed, 133 insertions, 43 deletions
diff --git a/arch/tile/kernel/vdso/vgettimeofday.c b/arch/tile/kernel/vdso/vgettimeofday.c
index e933fb9fbf5c..8bb21eda07d8 100644
--- a/arch/tile/kernel/vdso/vgettimeofday.c
+++ b/arch/tile/kernel/vdso/vgettimeofday.c
@@ -15,6 +15,7 @@
#define VDSO_BUILD /* avoid some shift warnings for -m32 in <asm/page.h> */
#include <linux/time.h>
#include <asm/timex.h>
+#include <asm/unistd.h>
#include <asm/vdso.h>
#if CHIP_HAS_SPLIT_CYCLE()
@@ -35,6 +36,11 @@ static inline cycles_t get_cycles_inline(void)
#define get_cycles get_cycles_inline
#endif
+struct syscall_return_value {
+ long value;
+ long error;
+};
+
/*
* Find out the vDSO data page address in the process address space.
*/
@@ -50,59 +56,143 @@ inline unsigned long get_datapage(void)
return ret;
}
-int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
+static inline u64 vgetsns(struct vdso_data *vdso)
+{
+ return ((get_cycles() - vdso->cycle_last) & vdso->mask) * vdso->mult;
+}
+
+static inline int do_realtime(struct vdso_data *vdso, struct timespec *ts)
+{
+ unsigned count;
+ u64 ns;
+
+ do {
+ count = read_seqcount_begin(&vdso->tb_seq);
+ ts->tv_sec = vdso->wall_time_sec;
+ ns = vdso->wall_time_snsec;
+ ns += vgetsns(vdso);
+ ns >>= vdso->shift;
+ } while (unlikely(read_seqcount_retry(&vdso->tb_seq, count)));
+
+ ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
+ ts->tv_nsec = ns;
+
+ return 0;
+}
+
+static inline int do_monotonic(struct vdso_data *vdso, struct timespec *ts)
+{
+ unsigned count;
+ u64 ns;
+
+ do {
+ count = read_seqcount_begin(&vdso->tb_seq);
+ ts->tv_sec = vdso->monotonic_time_sec;
+ ns = vdso->monotonic_time_snsec;
+ ns += vgetsns(vdso);
+ ns >>= vdso->shift;
+ } while (unlikely(read_seqcount_retry(&vdso->tb_seq, count)));
+
+ ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
+ ts->tv_nsec = ns;
+
+ return 0;
+}
+
+static inline int do_realtime_coarse(struct vdso_data *vdso,
+ struct timespec *ts)
+{
+ unsigned count;
+
+ do {
+ count = read_seqcount_begin(&vdso->tb_seq);
+ ts->tv_sec = vdso->wall_time_coarse_sec;
+ ts->tv_nsec = vdso->wall_time_coarse_nsec;
+ } while (unlikely(read_seqcount_retry(&vdso->tb_seq, count)));
+
+ return 0;
+}
+
+static inline int do_monotonic_coarse(struct vdso_data *vdso,
+ struct timespec *ts)
{
- cycles_t cycles;
- unsigned long count, sec, ns;
- volatile struct vdso_data *vdso_data;
+ unsigned count;
+
+ do {
+ count = read_seqcount_begin(&vdso->tb_seq);
+ ts->tv_sec = vdso->monotonic_time_coarse_sec;
+ ts->tv_nsec = vdso->monotonic_time_coarse_nsec;
+ } while (unlikely(read_seqcount_retry(&vdso->tb_seq, count)));
+
+ return 0;
+}
+
+struct syscall_return_value __vdso_gettimeofday(struct timeval *tv,
+ struct timezone *tz)
+{
+ struct syscall_return_value ret = { 0, 0 };
+ unsigned count;
+ struct vdso_data *vdso = (struct vdso_data *)get_datapage();
- vdso_data = (struct vdso_data *)get_datapage();
/* The use of the timezone is obsolete, normally tz is NULL. */
if (unlikely(tz != NULL)) {
- while (1) {
- /* Spin until the update finish. */
- count = vdso_data->tz_update_count;
- if (count & 1)
- continue;
-
- tz->tz_minuteswest = vdso_data->tz_minuteswest;
- tz->tz_dsttime = vdso_data->tz_dsttime;
-
- /* Check whether updated, read again if so. */
- if (count == vdso_data->tz_update_count)
- break;
- }
+ do {
+ count = read_seqcount_begin(&vdso->tz_seq);
+ tz->tz_minuteswest = vdso->tz_minuteswest;
+ tz->tz_dsttime = vdso->tz_dsttime;
+ } while (unlikely(read_seqcount_retry(&vdso->tz_seq, count)));
}
if (unlikely(tv == NULL))
- return 0;
-
- while (1) {
- /* Spin until the update finish. */
- count = vdso_data->tb_update_count;
- if (count & 1)
- continue;
-
- sec = vdso_data->xtime_clock_sec;
- cycles = get_cycles() - vdso_data->xtime_tod_stamp;
- ns = (cycles * vdso_data->mult) + vdso_data->xtime_clock_nsec;
- ns >>= vdso_data->shift;
-
- if (ns >= NSEC_PER_SEC) {
- ns -= NSEC_PER_SEC;
- sec += 1;
- }
-
- /* Check whether updated, read again if so. */
- if (count == vdso_data->tb_update_count)
- break;
- }
+ return ret;
- tv->tv_sec = sec;
- tv->tv_usec = ns / 1000;
+ do_realtime(vdso, (struct timespec *)tv);
+ tv->tv_usec /= 1000;
- return 0;
+ return ret;
}
int gettimeofday(struct timeval *tv, struct timezone *tz)
__attribute__((weak, alias("__vdso_gettimeofday")));
+
+static struct syscall_return_value vdso_fallback_gettime(long clock,
+ struct timespec *ts)
+{
+ struct syscall_return_value ret;
+ __asm__ __volatile__ (
+ "swint1"
+ : "=R00" (ret.value), "=R01" (ret.error)
+ : "R10" (__NR_clock_gettime), "R00" (clock), "R01" (ts)
+ : "r2", "r3", "r4", "r5", "r6", "r7",
+ "r8", "r9", "r11", "r12", "r13", "r14", "r15",
+ "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
+ "r24", "r25", "r26", "r27", "r28", "r29", "memory");
+ return ret;
+}
+
+struct syscall_return_value __vdso_clock_gettime(clockid_t clock,
+ struct timespec *ts)
+{
+ struct vdso_data *vdso = (struct vdso_data *)get_datapage();
+ struct syscall_return_value ret = { 0, 0 };
+
+ switch (clock) {
+ case CLOCK_REALTIME:
+ do_realtime(vdso, ts);
+ return ret;
+ case CLOCK_MONOTONIC:
+ do_monotonic(vdso, ts);
+ return ret;
+ case CLOCK_REALTIME_COARSE:
+ do_realtime_coarse(vdso, ts);
+ return ret;
+ case CLOCK_MONOTONIC_COARSE:
+ do_monotonic_coarse(vdso, ts);
+ return ret;
+ default:
+ return vdso_fallback_gettime(clock, ts);
+ }
+}
+
+int clock_gettime(clockid_t clock, struct timespec *ts)
+ __attribute__((weak, alias("__vdso_clock_gettime")));