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authorMark Johnston <markj@FreeBSD.org>2021-10-29 14:29:22 -0400
committerMoyano, Gabriel <gabriel.moyano@dlr.de>2021-11-16 09:48:22 +0100
commit1640657022d58e076bea0181b48942bd865a1398 (patch)
treed60d887be5213f9716316e6446d5540d1ac31d34
parentkern_tc.c: Scaling/large delta recalculation (diff)
downloadrtems-1640657022d58e076bea0181b48942bd865a1398.tar.bz2
timecounter: Load the currently selected tc once in tc_windup()
Reported by: Sebastian Huber <sebastian.huber@embedded-brains.de> Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D32729
-rw-r--r--cpukit/score/src/kern_tc.c23
1 files changed, 16 insertions, 7 deletions
diff --git a/cpukit/score/src/kern_tc.c b/cpukit/score/src/kern_tc.c
index 513341f4dc..0e6d98d117 100644
--- a/cpukit/score/src/kern_tc.c
+++ b/cpukit/score/src/kern_tc.c
@@ -110,6 +110,13 @@ atomic_store_rel_int(Atomic_Uint *i, u_int val)
_Atomic_Store_uint(i, val, ATOMIC_ORDER_RELEASE);
}
+
+static inline void *
+atomic_load_ptr(void *ptr)
+{
+
+ return ((void *)_Atomic_Load_uintptr(ptr, ATOMIC_ORDER_RELAXED));
+}
#endif /* __rtems__ */
/*
@@ -1559,6 +1566,7 @@ _Timecounter_Windup(struct bintime *new_boottimebin,
#endif /* __rtems__ */
{
struct bintime bt;
+ struct timecounter *tc;
struct timehands *th, *tho;
uint32_t delta, ncount, ogen;
int i;
@@ -1593,9 +1601,10 @@ _Timecounter_Windup(struct bintime *new_boottimebin,
* changing timecounters, a counter value from the new timecounter.
* Update the offset fields accordingly.
*/
+ tc = atomic_load_ptr(&timecounter);
delta = tc_delta(th);
- if (th->th_counter != timecounter)
- ncount = timecounter->tc_get_timecount(timecounter);
+ if (th->th_counter != tc)
+ ncount = tc->tc_get_timecount(tc);
else
ncount = 0;
#ifdef FFCLOCK
@@ -1661,20 +1670,20 @@ _Timecounter_Windup(struct bintime *new_boottimebin,
bintime2timespec(&bt, &th->th_nanotime);
/* Now is a good time to change timecounters. */
- if (th->th_counter != timecounter) {
+ if (th->th_counter != tc) {
#ifndef __rtems__
#ifndef __arm__
- if ((timecounter->tc_flags & TC_FLAGS_C2STOP) != 0)
+ if ((tc->tc_flags & TC_FLAGS_C2STOP) != 0)
cpu_disable_c2_sleep++;
if ((th->th_counter->tc_flags & TC_FLAGS_C2STOP) != 0)
cpu_disable_c2_sleep--;
#endif
#endif /* __rtems__ */
- th->th_counter = timecounter;
+ th->th_counter = tc;
th->th_offset_count = ncount;
#ifndef __rtems__
- tc_min_ticktock_freq = max(1, timecounter->tc_frequency /
- (((uint64_t)timecounter->tc_counter_mask + 1) / 3));
+ tc_min_ticktock_freq = max(1, tc->tc_frequency /
+ (((uint64_t)tc->tc_counter_mask + 1) / 3));
#endif /* __rtems__ */
recalculate_scaling_factor_and_large_delta(th);
#ifdef FFCLOCK