[PATCH v2] perf/arm-cmn: Fix multi-filter encoding
Robin Murphy
robin.murphy at arm.com
Tue Sep 15 05:24:22 PDT 2026
The current special-case for EVICT_STATE_SEL filtering effectively
assigns the "filter" and "filter2" controls in the opposite order from
how the CMN S3 r2 TRM states "Filtering is programmed in pmu_hbt_lbt_sel
and pmu_evict_state_sel". On reflection, not only does this seem
unnecessarily non-obvious to users, but it's also likely to be a problem
for scaling to a full multi-filter abstraction in future. There is a
logical order to filters based on their bitfield positions in the
pmu_event_sel register, which the TRM descriptions allude to, and the
cmn_filter_select enum already (almost) follows, so let's fix the UABI
to follow suit while it's still unreleased.
Fixes: 09178f536bb9 ("perf/arm-cmn: Plumb in new filter types")
Signed-off-by: Robin Murphy <robin.murphy at arm.com>
---
v2: Also fix filter lookup order and missing return in set_event_filter
drivers/perf/arm-cmn.c | 58 +++++++++++++++++++++++++-----------------
1 file changed, 34 insertions(+), 24 deletions(-)
diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
index b162de3d9d16..33e8a040c903 100644
--- a/drivers/perf/arm-cmn.c
+++ b/drivers/perf/arm-cmn.c
@@ -305,9 +305,9 @@ enum cmn_filter_select {
SEL_NONE,
SEL_OCCUP1_ID,
SEL_CLASS_OCCUP_ID,
- SEL_CBUSY_SNTHROTTLE_SEL,
SEL_HBT_LBT_SEL,
SEL_SN_HOME_SEL,
+ SEL_CBUSY_SNTHROTTLE_SEL,
SEL_SNP_VC_SEL,
SEL_ENHANCED_HBT_LBT_SEL,
SEL_EVICT_STATE_SEL,
@@ -978,10 +978,14 @@ static umode_t arm_cmn_event_attr_is_visible(struct kobject *kobj,
_CMN_EVENT_HNS(_model, _name##_all, _event, _sel, 0), \
_CMN_EVENT_HNS(_model, _name##_hbt, _event, _sel, 1), \
_CMN_EVENT_HNS(_model, _name##_lbt, _event, _sel, 2)
-#define _CMN_EVENT_HNS_HBT2(_model, _name, _event, _fsel1, f1) \
- _CMN_EVENT_HNS(_model, _name##_all, _event, _fsel1, f1, SEL_HBT_LBT_SEL, 0), \
- _CMN_EVENT_HNS(_model, _name##_hbt, _event, _fsel1, f1, SEL_HBT_LBT_SEL, 1), \
- _CMN_EVENT_HNS(_model, _name##_lbt, _event, _fsel1, f1, SEL_HBT_LBT_SEL, 2)
+#define _CMN_EVENT_HNS_EVICT(_model, _name, _event, _fsel1, f1) \
+ _CMN_EVENT_HNS(_model, _name##_all, _event, _fsel1, f1, SEL_EVICT_STATE_SEL, 0), \
+ _CMN_EVENT_HNS(_model, _name##_eu, _event, _fsel1, f1, SEL_EVICT_STATE_SEL, 1), \
+ _CMN_EVENT_HNS(_model, _name##_en, _event, _fsel1, f1, SEL_EVICT_STATE_SEL, 2), \
+ _CMN_EVENT_HNS(_model, _name##_su, _event, _fsel1, f1, SEL_EVICT_STATE_SEL, 3), \
+ _CMN_EVENT_HNS(_model, _name##_sn, _event, _fsel1, f1, SEL_EVICT_STATE_SEL, 4), \
+ _CMN_EVENT_HNS(_model, _name##_mu, _event, _fsel1, f1, SEL_EVICT_STATE_SEL, 5), \
+ _CMN_EVENT_HNS(_model, _name##_mn, _event, _fsel1, f1, SEL_EVICT_STATE_SEL, 6)
#define CMN_EVENT_HNS_OCC(_model, _name, _event) \
CMN_EVENT_HN_OCC(_model, hns_##_name, CMN_TYPE_HNS, _event), \
@@ -1014,13 +1018,9 @@ static umode_t arm_cmn_event_attr_is_visible(struct kobject *kobj,
_CMN_EVENT_HNS(CMNS3R2, _name##_ccglcn, _event, SEL_ENHANCED_HBT_LBT_SEL, 5), \
_CMN_EVENT_HNS(CMNS3R2, _name##_ccgrn, _event, SEL_ENHANCED_HBT_LBT_SEL, 6)
#define CMN_EVENT_HNS_EVICT(_model, _name, _event) \
- _CMN_EVENT_HNS_HBT2(_model, _name##_all, _event, SEL_EVICT_STATE_SEL, 0), \
- _CMN_EVENT_HNS_HBT2(_model, _name##_eu, _event, SEL_EVICT_STATE_SEL, 1), \
- _CMN_EVENT_HNS_HBT2(_model, _name##_en, _event, SEL_EVICT_STATE_SEL, 2), \
- _CMN_EVENT_HNS_HBT2(_model, _name##_su, _event, SEL_EVICT_STATE_SEL, 3), \
- _CMN_EVENT_HNS_HBT2(_model, _name##_sn, _event, SEL_EVICT_STATE_SEL, 4), \
- _CMN_EVENT_HNS_HBT2(_model, _name##_mu, _event, SEL_EVICT_STATE_SEL, 5), \
- _CMN_EVENT_HNS_HBT2(_model, _name##_mn, _event, SEL_EVICT_STATE_SEL, 6)
+ _CMN_EVENT_HNS_EVICT(_model, _name##_all, _event, SEL_HBT_LBT_SEL, 0), \
+ _CMN_EVENT_HNS_EVICT(_model, _name##_hbt, _event, SEL_HBT_LBT_SEL, 1), \
+ _CMN_EVENT_HNS_EVICT(_model, _name##_lbt, _event, SEL_HBT_LBT_SEL, 2)
#define CMN_EVENT_HNSR0_HBT(_name, _event) \
_CMN_EVENT_HNS_HBT(CMN700 | CMNS3R01, _name, _event, SEL_HBT_LBT_SEL)
@@ -1856,10 +1856,12 @@ static void arm_cmn_val_add_event(struct arm_cmn *cmn, struct arm_cmn_val *val,
val->dtm_count[dtm]++;
+ if (sel == SEL_EVICT_STATE_SEL) {
+ val->filter[dtm][sel] = CMN_EVENT_FILTER2(event) + 1;
+ sel = SEL_HBT_LBT_SEL;
+ }
if (sel)
val->filter[dtm][sel] = CMN_EVENT_FILTER(event) + 1;
- if (sel == SEL_EVICT_STATE_SEL)
- val->filter[dtm][SEL_HBT_LBT_SEL] = CMN_EVENT_FILTER2(event) + 1;
if (type != CMN_TYPE_WP)
continue;
@@ -1910,14 +1912,17 @@ static int arm_cmn_validate_group(struct arm_cmn *cmn, struct perf_event *event)
if (val->dtm_count[dtm] == CMN_DTM_NUM_COUNTERS)
goto done;
+ if (sel == SEL_EVICT_STATE_SEL) {
+ if (val->filter[dtm][sel] &&
+ val->filter[dtm][sel] != CMN_EVENT_FILTER2(event) + 1)
+ goto done;
+ sel = SEL_HBT_LBT_SEL;
+ }
+
if (sel && val->filter[dtm][sel] &&
val->filter[dtm][sel] != CMN_EVENT_FILTER(event) + 1)
goto done;
- if (sel == SEL_EVICT_STATE_SEL && val->filter[dtm][SEL_HBT_LBT_SEL] &&
- val->filter[dtm][SEL_HBT_LBT_SEL] != CMN_EVENT_FILTER2(event) + 1)
- goto done;
-
if (type != CMN_TYPE_WP)
continue;
@@ -1946,7 +1951,7 @@ static enum cmn_filter_select arm_cmn_event_filter(const struct arm_cmn *cmn,
for (int i = 0; i < ARRAY_SIZE(arm_cmn_event_attrs) - 1; i++) {
e = container_of(arm_cmn_event_attrs[i], typeof(*e), attr.attr);
if (e->model & model && e->type == type && e->eventid == eventid)
- return e->filter[0].sel;
+ return e->filter[1].sel ?: e->filter[0].sel;
}
return SEL_NONE;
}
@@ -2077,16 +2082,21 @@ static void arm_cmn_event_clear(struct arm_cmn *cmn, struct perf_event *event,
static int arm_cmn_set_event_filter(struct arm_cmn_node *dn, struct perf_event *event)
{
enum cmn_filter_select fsel = to_cmn_hw(event)->filter_sel;
+ bool evict_state = fsel == SEL_EVICT_STATE_SEL;
int ret = 0;
+ if (evict_state) {
+ ret = arm_cmn_set_event_sel_hi(dn, fsel, CMN_EVENT_FILTER2(event));
+ if (ret)
+ return ret;
+ fsel = SEL_HBT_LBT_SEL;
+ }
if (fsel)
ret = arm_cmn_set_event_sel_hi(dn, fsel, CMN_EVENT_FILTER(event));
- if (fsel == SEL_EVICT_STATE_SEL && !ret) {
- ret = arm_cmn_set_event_sel_hi(dn, SEL_HBT_LBT_SEL, CMN_EVENT_FILTER2(event));
- if (ret)
- dn->filter[fsel].count--;
- }
+ if (ret && evict_state)
+ dn->filter[SEL_EVICT_STATE_SEL].count--;
+
return ret;
}
--
2.54.0.dirty
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