Use READ_ONCE_ALIGNED_128() to read the previous value in front of a
128-bit cmpxchg loop, instead of (mis-)using a 128-bit cmpxchg operation to
do the same.
This makes the code more readable and is faster.
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
---
arch/s390/kernel/perf_cpum_sf.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c
index 79904a839fb9..e7b867e2f73f 100644
--- a/arch/s390/kernel/perf_cpum_sf.c
+++ b/arch/s390/kernel/perf_cpum_sf.c
@@ -1355,8 +1355,7 @@ static void hw_perf_event_update(struct perf_event *event, int flush_all)
num_sdb++;
/* Reset trailer (using compare-double-and-swap) */
- /* READ_ONCE() 16 byte header */
- prev.val = __cdsg(&te->header.val, 0, 0);
+ prev.val = READ_ONCE_ALIGNED_128(te->header.val);
do {
old.val = prev.val;
new.val = prev.val;
@@ -1558,8 +1557,7 @@ static bool aux_set_alert(struct aux_buffer *aux, unsigned long alert_index,
struct hws_trailer_entry *te;
te = aux_sdb_trailer(aux, alert_index);
- /* READ_ONCE() 16 byte header */
- prev.val = __cdsg(&te->header.val, 0, 0);
+ prev.val = READ_ONCE_ALIGNED_128(te->header.val);
do {
old.val = prev.val;
new.val = prev.val;
@@ -1637,8 +1635,7 @@ static bool aux_reset_buffer(struct aux_buffer *aux, unsigned long range,
idx_old = idx = aux->empty_mark + 1;
for (i = 0; i < range_scan; i++, idx++) {
te = aux_sdb_trailer(aux, idx);
- /* READ_ONCE() 16 byte header */
- prev.val = __cdsg(&te->header.val, 0, 0);
+ prev.val = READ_ONCE_ALIGNED_128(te->header.val);
do {
old.val = prev.val;
new.val = prev.val;
--
2.37.2
