[PATCH v1 4/8] time/sched_clock: Use seqcount_latch_t

Ahmed S. Darwish
2020-08-27T11:54:47Z

Latch sequence counters have unique read and write APIs, and thus
seqcount_latch_t was recently introduced at seqlock.h.

Use that new data type instead of plain seqcount_t. This adds the
necessary type-safety and ensures only latching-safe seqcount APIs are
to be used.

Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
---
kernel/time/sched_clock.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
index 8c6b5febd7a0..0642013dace4 100644
--- a/kernel/time/sched_clock.c
+++ b/kernel/time/sched_clock.c
@@ -35,7 +35,7 @@
* into a single 64-byte cache line.
*/
struct clock_data {
- seqcount_t seq;
+ seqcount_latch_t seq;
struct clock_read_data read_data[2];
ktime_t wrap_kt;
unsigned long rate;
@@ -76,7 +76,7 @@ struct clock_read_data *sched_clock_read_begin(unsigned int *seq)

int sched_clock_read_retry(unsigned int seq)
{
- return read_seqcount_retry(&cd.seq, seq);
+ return read_seqcount_latch_retry(&cd.seq, seq);
}

unsigned long long notrace sched_clock(void)
--
2.28.0