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Diffstat (limited to 'arch/s390/kernel/perf_cpum_sf.c')
-rw-r--r--arch/s390/kernel/perf_cpum_sf.c101
1 files changed, 62 insertions, 39 deletions
diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c
index 332a49965130..ce886a03545a 100644
--- a/arch/s390/kernel/perf_cpum_sf.c
+++ b/arch/s390/kernel/perf_cpum_sf.c
@@ -163,14 +163,15 @@ static void free_sampling_buffer(struct sf_buffer *sfb)
static int alloc_sample_data_block(unsigned long *sdbt, gfp_t gfp_flags)
{
- unsigned long sdb, *trailer;
+ struct hws_trailer_entry *te;
+ unsigned long sdb;
/* Allocate and initialize sample-data-block */
sdb = get_zeroed_page(gfp_flags);
if (!sdb)
return -ENOMEM;
- trailer = trailer_entry_ptr(sdb);
- *trailer = SDB_TE_ALERT_REQ_MASK;
+ te = (struct hws_trailer_entry *)trailer_entry_ptr(sdb);
+ te->header.a = 1;
/* Link SDB into the sample-data-block-table */
*sdbt = sdb;
@@ -1206,7 +1207,7 @@ static void hw_collect_samples(struct perf_event *event, unsigned long *sdbt,
"%s: Found unknown"
" sampling data entry: te->f %i"
" basic.def %#4x (%p)\n", __func__,
- te->f, sample->def, sample);
+ te->header.f, sample->def, sample);
/* Sample slot is not yet written or other record.
*
* This condition can occur if the buffer was reused
@@ -1217,7 +1218,7 @@ static void hw_collect_samples(struct perf_event *event, unsigned long *sdbt,
* that are not full. Stop processing if the first
* invalid format was detected.
*/
- if (!te->f)
+ if (!te->header.f)
break;
}
@@ -1227,6 +1228,16 @@ static void hw_collect_samples(struct perf_event *event, unsigned long *sdbt,
}
}
+static inline __uint128_t __cdsg(__uint128_t *ptr, __uint128_t old, __uint128_t new)
+{
+ asm volatile(
+ " cdsg %[old],%[new],%[ptr]\n"
+ : [old] "+d" (old), [ptr] "+QS" (*ptr)
+ : [new] "d" (new)
+ : "memory", "cc");
+ return old;
+}
+
/* hw_perf_event_update() - Process sampling buffer
* @event: The perf event
* @flush_all: Flag to also flush partially filled sample-data-blocks
@@ -1243,10 +1254,11 @@ static void hw_collect_samples(struct perf_event *event, unsigned long *sdbt,
*/
static void hw_perf_event_update(struct perf_event *event, int flush_all)
{
+ unsigned long long event_overflow, sampl_overflow, num_sdb;
+ union hws_trailer_header old, prev, new;
struct hw_perf_event *hwc = &event->hw;
struct hws_trailer_entry *te;
unsigned long *sdbt;
- unsigned long long event_overflow, sampl_overflow, num_sdb, te_flags;
int done;
/*
@@ -1266,25 +1278,25 @@ static void hw_perf_event_update(struct perf_event *event, int flush_all)
te = (struct hws_trailer_entry *) trailer_entry_ptr(*sdbt);
/* Leave loop if no more work to do (block full indicator) */
- if (!te->f) {
+ if (!te->header.f) {
done = 1;
if (!flush_all)
break;
}
/* Check the sample overflow count */
- if (te->overflow)
+ if (te->header.overflow)
/* Account sample overflows and, if a particular limit
* is reached, extend the sampling buffer.
* For details, see sfb_account_overflows().
*/
- sampl_overflow += te->overflow;
+ sampl_overflow += te->header.overflow;
/* Timestamps are valid for full sample-data-blocks only */
debug_sprintf_event(sfdbg, 6, "%s: sdbt %#lx "
"overflow %llu timestamp %#llx\n",
- __func__, (unsigned long)sdbt, te->overflow,
- (te->f) ? trailer_timestamp(te) : 0ULL);
+ __func__, (unsigned long)sdbt, te->header.overflow,
+ (te->header.f) ? trailer_timestamp(te) : 0ULL);
/* Collect all samples from a single sample-data-block and
* flag if an (perf) event overflow happened. If so, the PMU
@@ -1294,12 +1306,16 @@ 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);
do {
- te_flags = te->flags & ~SDB_TE_BUFFER_FULL_MASK;
- te_flags |= SDB_TE_ALERT_REQ_MASK;
- } while (!cmpxchg_double(&te->flags, &te->overflow,
- te->flags, te->overflow,
- te_flags, 0ULL));
+ old.val = prev.val;
+ new.val = prev.val;
+ new.f = 0;
+ new.a = 1;
+ new.overflow = 0;
+ prev.val = __cdsg(&te->header.val, old.val, new.val);
+ } while (prev.val != old.val);
/* Advance to next sample-data-block */
sdbt++;
@@ -1384,7 +1400,7 @@ static void aux_output_end(struct perf_output_handle *handle)
range_scan = AUX_SDB_NUM_ALERT(aux);
for (i = 0, idx = aux->head; i < range_scan; i++, idx++) {
te = aux_sdb_trailer(aux, idx);
- if (!(te->flags & SDB_TE_BUFFER_FULL_MASK))
+ if (!te->header.f)
break;
}
/* i is num of SDBs which are full */
@@ -1392,7 +1408,7 @@ static void aux_output_end(struct perf_output_handle *handle)
/* Remove alert indicators in the buffer */
te = aux_sdb_trailer(aux, aux->alert_mark);
- te->flags &= ~SDB_TE_ALERT_REQ_MASK;
+ te->header.a = 0;
debug_sprintf_event(sfdbg, 6, "%s: SDBs %ld range %ld head %ld\n",
__func__, i, range_scan, aux->head);
@@ -1437,9 +1453,9 @@ static int aux_output_begin(struct perf_output_handle *handle,
idx = aux->empty_mark + 1;
for (i = 0; i < range_scan; i++, idx++) {
te = aux_sdb_trailer(aux, idx);
- te->flags &= ~(SDB_TE_BUFFER_FULL_MASK |
- SDB_TE_ALERT_REQ_MASK);
- te->overflow = 0;
+ te->header.f = 0;
+ te->header.a = 0;
+ te->header.overflow = 0;
}
/* Save the position of empty SDBs */
aux->empty_mark = aux->head + range - 1;
@@ -1448,7 +1464,7 @@ static int aux_output_begin(struct perf_output_handle *handle,
/* Set alert indicator */
aux->alert_mark = aux->head + range/2 - 1;
te = aux_sdb_trailer(aux, aux->alert_mark);
- te->flags = te->flags | SDB_TE_ALERT_REQ_MASK;
+ te->header.a = 1;
/* Reset hardware buffer head */
head = AUX_SDB_INDEX(aux, aux->head);
@@ -1475,14 +1491,17 @@ static int aux_output_begin(struct perf_output_handle *handle,
static bool aux_set_alert(struct aux_buffer *aux, unsigned long alert_index,
unsigned long long *overflow)
{
- unsigned long long orig_overflow, orig_flags, new_flags;
+ union hws_trailer_header old, prev, new;
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);
do {
- orig_flags = te->flags;
- *overflow = orig_overflow = te->overflow;
- if (orig_flags & SDB_TE_BUFFER_FULL_MASK) {
+ old.val = prev.val;
+ new.val = prev.val;
+ *overflow = old.overflow;
+ if (old.f) {
/*
* SDB is already set by hardware.
* Abort and try to set somewhere
@@ -1490,10 +1509,10 @@ static bool aux_set_alert(struct aux_buffer *aux, unsigned long alert_index,
*/
return false;
}
- new_flags = orig_flags | SDB_TE_ALERT_REQ_MASK;
- } while (!cmpxchg_double(&te->flags, &te->overflow,
- orig_flags, orig_overflow,
- new_flags, 0ULL));
+ new.a = 1;
+ new.overflow = 0;
+ prev.val = __cdsg(&te->header.val, old.val, new.val);
+ } while (prev.val != old.val);
return true;
}
@@ -1522,8 +1541,9 @@ static bool aux_set_alert(struct aux_buffer *aux, unsigned long alert_index,
static bool aux_reset_buffer(struct aux_buffer *aux, unsigned long range,
unsigned long long *overflow)
{
- unsigned long long orig_overflow, orig_flags, new_flags;
unsigned long i, range_scan, idx, idx_old;
+ union hws_trailer_header old, prev, new;
+ unsigned long long orig_overflow;
struct hws_trailer_entry *te;
debug_sprintf_event(sfdbg, 6, "%s: range %ld head %ld alert %ld "
@@ -1554,17 +1574,20 @@ 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);
do {
- orig_flags = te->flags;
- orig_overflow = te->overflow;
- new_flags = orig_flags & ~SDB_TE_BUFFER_FULL_MASK;
+ old.val = prev.val;
+ new.val = prev.val;
+ orig_overflow = old.overflow;
+ new.f = 0;
+ new.overflow = 0;
if (idx == aux->alert_mark)
- new_flags |= SDB_TE_ALERT_REQ_MASK;
+ new.a = 1;
else
- new_flags &= ~SDB_TE_ALERT_REQ_MASK;
- } while (!cmpxchg_double(&te->flags, &te->overflow,
- orig_flags, orig_overflow,
- new_flags, 0ULL));
+ new.a = 0;
+ prev.val = __cdsg(&te->header.val, old.val, new.val);
+ } while (prev.val != old.val);
*overflow += orig_overflow;
}
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-06 08:17:51 +0300