diff options
| author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2021-10-11 10:45:27 +0200 |
|---|---|---|
| committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2021-11-15 08:56:54 +0100 |
| commit | 52c53a5914f5fbe92e5b935df2b3c3fadb47d1d5 (patch) | |
| tree | a46fbbdfe92d68dad9977f1f727342b0a16314bc /cpukit/score/src/kern_tc.c | |
| parent | score: Initialize timehand generation to UINT_MAX (diff) | |
| download | rtems-52c53a5914f5fbe92e5b935df2b3c3fadb47d1d5.tar.bz2 | |
score: Port large time delta support to RTEMS
Diffstat (limited to '')
| -rw-r--r-- | cpukit/score/src/kern_tc.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/cpukit/score/src/kern_tc.c b/cpukit/score/src/kern_tc.c index e43e3226b1..5544b9ecde 100644 --- a/cpukit/score/src/kern_tc.c +++ b/cpukit/score/src/kern_tc.c @@ -175,7 +175,7 @@ struct timehands { struct timecounter *th_counter; int64_t th_adjustment; uint64_t th_scale; - u_int th_large_delta; + uint32_t th_large_delta; uint32_t th_offset_count; struct bintime th_offset; struct bintime th_bintime; @@ -235,6 +235,7 @@ static struct timehands th0 = { .th_counter = &dummy_timecounter, .th_scale = (uint64_t)-1 / 1000000, .th_offset = { .sec = 1 }, + .th_large_delta = 1000000, .th_generation = UINT_MAX, #ifdef __rtems__ .th_bintime = { .sec = TOD_SECONDS_1970_THROUGH_1988 }, @@ -390,7 +391,12 @@ bintime_off(struct bintime *bt, u_int off) struct timehands *th; struct bintime *btp; uint64_t scale, x; +#ifndef __rtems__ u_int delta, gen, large_delta; +#else /* __rtems__ */ + uint32_t delta, large_delta; + u_int gen; +#endif /* __rtems__ */ do { th = timehands; @@ -553,17 +559,30 @@ sbintime_t _Timecounter_Sbinuptime(void) { struct timehands *th; - uint32_t gen; sbintime_t sbt; + uint64_t scale; + uint32_t delta; + uint32_t large_delta; + u_int gen; do { th = timehands; gen = atomic_load_acq_int(&th->th_generation); sbt = bttosbt(th->th_offset); - sbt += (th->th_scale * tc_delta(th)) >> 32; + scale = th->th_scale; + delta = tc_delta(th); + large_delta = th->th_large_delta; atomic_thread_fence_acq(); } while (gen == 0 || gen != th->th_generation); + if (__predict_false(delta >= large_delta)) { + /* Avoid overflow for scale * delta. */ + sbt += (scale >> 32) * delta; + sbt += ((scale & 0xffffffff) * delta) >> 32; + } else { + sbt += (scale * delta) >> 32; + } + return (sbt); } #endif /* __rtems__ */ |