[PATCH 2/5] perf/arm-cmn: Refactor event filter programming
Robin Murphy
robin.murphy at arm.com
Tue Jun 30 08:19:17 PDT 2026
We're soon going to need to cope with events having multiple filters,
plus the filter fields themselves moving around, wherein any more inline
if/else logic will struggle to scale. Add a more general abstraction for
the node-specific filter controls, and rejig the pmu_event_sel filter
programming around it in a more extensible manner.
Signed-off-by: Robin Murphy <robin.murphy at arm.com>
---
drivers/perf/arm-cmn.c | 139 ++++++++++++++++++++++++++++++-----------
1 file changed, 101 insertions(+), 38 deletions(-)
diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
index 2a8a67da72c3..14c267d2e2f9 100644
--- a/drivers/perf/arm-cmn.c
+++ b/drivers/perf/arm-cmn.c
@@ -278,8 +278,8 @@ enum cmn_node_type {
};
enum cmn_filter_select {
- SEL_NONE = -1,
- SEL_OCCUP1ID,
+ SEL_NONE,
+ SEL_OCCUP1_ID,
SEL_CLASS_OCCUP_ID,
SEL_CBUSY_SNTHROTTLE_SEL,
SEL_HBT_LBT_SEL,
@@ -599,6 +599,57 @@ static void arm_cmn_debugfs_init(struct arm_cmn *cmn, int id)
static void arm_cmn_debugfs_init(struct arm_cmn *cmn, int id) {}
#endif
+enum cmn_filter_type {
+ FILT_NONE,
+ FILT_OCCUP1_ID,
+ FILT_HNF_700,
+ FILT_HNS,
+};
+#define CMN_FILTER(_sel) [SEL_##_sel] = CMN__PMU_##_sel
+
+static const u64 arm_cmn_filters[][SEL_MAX] = {
+ [FILT_NONE] = {},
+ /* DVM etc. */
+ [FILT_OCCUP1_ID] = {
+ CMN_FILTER(OCCUP1_ID)
+ },
+ /* Newer HN-F */
+ [FILT_HNF_700] = {
+ CMN_FILTER(OCCUP1_ID),
+ CMN_FILTER(CLASS_OCCUP_ID),
+ CMN_FILTER(CBUSY_SNTHROTTLE_SEL)
+ },
+ /* HN-S */
+ [FILT_HNS] = {
+ CMN_FILTER(OCCUP1_ID),
+ CMN_FILTER(CLASS_OCCUP_ID),
+ CMN_FILTER(CBUSY_SNTHROTTLE_SEL),
+ CMN_FILTER(HBT_LBT_SEL),
+ CMN_FILTER(SN_HOME_SEL)
+ },
+};
+
+static enum cmn_filter_type arm_cmn_filter(enum cmn_node_type node,
+ enum cmn_model model)
+{
+ switch (node) {
+ default:
+ return FILT_NONE;
+ case CMN_TYPE_DVM:
+ case CMN_TYPE_CXRA:
+ case CMN_TYPE_CXHA:
+ case CMN_TYPE_CCRA:
+ case CMN_TYPE_CCHA:
+ return FILT_OCCUP1_ID;
+ case CMN_TYPE_HNF:
+ if (model < CMN700)
+ return FILT_OCCUP1_ID;
+ return FILT_HNF_700;
+ case CMN_TYPE_HNS:
+ return FILT_HNS;
+ };
+}
+
struct arm_cmn_hw_event {
struct arm_cmn_node *dn;
union {
@@ -708,7 +759,7 @@ static ssize_t arm_cmn_event_show(struct device *dev,
"type=0x%x,eventid=0x%x,wp_dev_sel=?,wp_chn_sel=?,wp_grp=?,wp_val=?,wp_mask=?\n",
eattr->type, eattr->eventid);
- if (eattr->fsel > SEL_NONE)
+ if (eattr->fsel)
return sysfs_emit(buf, "type=0x%x,eventid=0x%x,filter=0x%x\n",
eattr->type, eattr->eventid, eattr->filter);
@@ -832,16 +883,16 @@ static umode_t arm_cmn_event_attr_is_visible(struct kobject *kobj,
#define CMN_EVENT_DVM(_model, _name, _event) \
_CMN_EVENT_DVM(_model, _name, _event, 0, SEL_NONE)
#define CMN_EVENT_DVM_OCC(_model, _name, _event) \
- _CMN_EVENT_DVM(_model, _name##_all, _event, 0, SEL_OCCUP1ID), \
- _CMN_EVENT_DVM(_model, _name##_dvmop, _event, 1, SEL_OCCUP1ID), \
- _CMN_EVENT_DVM(_model, _name##_dvmsync, _event, 2, SEL_OCCUP1ID)
+ _CMN_EVENT_DVM(_model, _name##_all, _event, 0, SEL_OCCUP1_ID), \
+ _CMN_EVENT_DVM(_model, _name##_dvmop, _event, 1, SEL_OCCUP1_ID), \
+ _CMN_EVENT_DVM(_model, _name##_dvmsync, _event, 2, SEL_OCCUP1_ID)
#define CMN_EVENT_HN_OCC(_model, _name, _type, _event) \
- _CMN_EVENT_ATTR(_model, _name##_all, _type, _event, 0, SEL_OCCUP1ID), \
- _CMN_EVENT_ATTR(_model, _name##_read, _type, _event, 1, SEL_OCCUP1ID), \
- _CMN_EVENT_ATTR(_model, _name##_write, _type, _event, 2, SEL_OCCUP1ID), \
- _CMN_EVENT_ATTR(_model, _name##_atomic, _type, _event, 3, SEL_OCCUP1ID), \
- _CMN_EVENT_ATTR(_model, _name##_stash, _type, _event, 4, SEL_OCCUP1ID)
+ _CMN_EVENT_ATTR(_model, _name##_all, _type, _event, 0, SEL_OCCUP1_ID), \
+ _CMN_EVENT_ATTR(_model, _name##_read, _type, _event, 1, SEL_OCCUP1_ID), \
+ _CMN_EVENT_ATTR(_model, _name##_write, _type, _event, 2, SEL_OCCUP1_ID), \
+ _CMN_EVENT_ATTR(_model, _name##_atomic, _type, _event, 3, SEL_OCCUP1_ID), \
+ _CMN_EVENT_ATTR(_model, _name##_stash, _type, _event, 4, SEL_OCCUP1_ID)
#define CMN_EVENT_HN_CLS(_model, _name, _type, _event) \
_CMN_EVENT_ATTR(_model, _name##_class0, _type, _event, 0, SEL_CLASS_OCCUP_ID), \
_CMN_EVENT_ATTR(_model, _name##_class1, _type, _event, 1, SEL_CLASS_OCCUP_ID), \
@@ -865,9 +916,9 @@ static umode_t arm_cmn_event_attr_is_visible(struct kobject *kobj,
#define CMN_EVENT_HNS_OCC(_name, _event) \
CMN_EVENT_HN_OCC(CMN_ANY, hns_##_name, CMN_TYPE_HNS, _event), \
- _CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_rxsnp, CMN_TYPE_HNS, _event, 5, SEL_OCCUP1ID), \
- _CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_lbt, CMN_TYPE_HNS, _event, 6, SEL_OCCUP1ID), \
- _CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_hbt, CMN_TYPE_HNS, _event, 7, SEL_OCCUP1ID)
+ _CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_rxsnp, CMN_TYPE_HNS, _event, 5, SEL_OCCUP1_ID), \
+ _CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_lbt, CMN_TYPE_HNS, _event, 6, SEL_OCCUP1_ID), \
+ _CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_hbt, CMN_TYPE_HNS, _event, 7, SEL_OCCUP1_ID)
#define CMN_EVENT_HNS_CLS( _name, _event) \
CMN_EVENT_HN_CLS(CMN_ANY, hns_##_name, CMN_TYPE_HNS, _event)
#define CMN_EVENT_HNS_SNT(_name, _event) \
@@ -1547,27 +1598,20 @@ static void arm_cmn_event_read(struct perf_event *event)
}
static int arm_cmn_set_event_sel_hi(struct arm_cmn_node *dn,
- enum cmn_filter_select fsel, u8 filter)
+ enum cmn_filter_select fsel, u8 val)
{
- u64 reg;
-
- if (fsel == SEL_NONE)
- return 0;
-
if (!dn->filter[fsel].count) {
- dn->filter[fsel].val = filter;
- reg = FIELD_PREP(CMN__PMU_CBUSY_SNTHROTTLE_SEL,
- dn->filter[SEL_CBUSY_SNTHROTTLE_SEL].val) |
- FIELD_PREP(CMN__PMU_SN_HOME_SEL,
- dn->filter[SEL_SN_HOME_SEL].val) |
- FIELD_PREP(CMN__PMU_HBT_LBT_SEL,
- dn->filter[SEL_HBT_LBT_SEL].val) |
- FIELD_PREP(CMN__PMU_CLASS_OCCUP_ID,
- dn->filter[SEL_CLASS_OCCUP_ID].val) |
- FIELD_PREP(CMN__PMU_OCCUP1_ID,
- dn->filter[SEL_OCCUP1ID].val);
+ const u64 *filter = arm_cmn_filters[dn->filter[SEL_NONE].val];
+ u64 reg = 0;
+
+ dn->filter[fsel].val = val;
+ for (int i = SEL_OCCUP1_ID; i < SEL_MAX; i++) {
+ if (filter[i])
+ reg |= field_prep(filter[i], dn->filter[i].val);
+ }
+
writel_relaxed(reg >> 32, dn->pmu_base + CMN_PMU_EVENT_SEL + 4);
- } else if (dn->filter[fsel].val != filter) {
+ } else if (dn->filter[fsel].val != val) {
return -EBUSY;
}
dn->filter[fsel].count++;
@@ -1696,7 +1740,7 @@ static void arm_cmn_val_add_event(struct arm_cmn *cmn, struct arm_cmn_val *val,
val->dtm_count[dtm]++;
- if (sel > SEL_NONE)
+ if (sel)
val->filter[dtm][sel] = CMN_EVENT_FILTER(event) + 1;
if (type != CMN_TYPE_WP)
@@ -1748,7 +1792,7 @@ 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_NONE && val->filter[dtm][sel] &&
+ if (sel && val->filter[dtm][sel] &&
val->filter[dtm][sel] != CMN_EVENT_FILTER(event) + 1)
goto done;
@@ -1894,7 +1938,7 @@ static void arm_cmn_event_clear(struct arm_cmn *cmn, struct perf_event *event,
dtm->wp_event[wp_idx] = -1;
}
- if (hw->filter_sel > SEL_NONE)
+ if (hw->filter_sel)
hw->dn[i].filter[hw->filter_sel].count--;
dtm->pmu_config_low &= ~CMN__PMEVCNT_PAIRED(dtm_idx);
@@ -1906,6 +1950,17 @@ static void arm_cmn_event_clear(struct arm_cmn *cmn, struct perf_event *event,
cmn->dtc[j].counters[idx] = NULL;
}
+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;
+ int ret = 0;
+
+ if (fsel)
+ ret = arm_cmn_set_event_sel_hi(dn, fsel, CMN_EVENT_FILTER(event));
+
+ return ret;
+}
+
static int arm_cmn_event_add(struct perf_event *event, int flags)
{
struct arm_cmn *cmn = to_cmn(event->pmu);
@@ -1981,7 +2036,7 @@ static int arm_cmn_event_add(struct perf_event *event, int flags)
input_sel = CMN__PMEVCNT0_INPUT_SEL_DEV + dtm_idx +
(nid.port << 4) + (nid.dev << 2);
- if (arm_cmn_set_event_sel_hi(dn, hw->filter_sel, CMN_EVENT_FILTER(event)))
+ if (arm_cmn_set_event_filter(dn, event))
goto free_dtms;
}
@@ -2311,6 +2366,7 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset)
void __iomem *cfg_region, __iomem *xp_region;
struct arm_cmn_node cfg, *dn;
struct arm_cmn_dtm *dtm;
+ enum cmn_model model;
enum cmn_part part;
u16 child_count, child_poff;
u64 reg;
@@ -2342,12 +2398,14 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset)
"Firmware binding mismatch: expected part number 0x%x, found 0x%x\n",
cmn->part, part);
cmn->part = part;
- if (!arm_cmn_model(cmn))
- dev_warn(cmn->dev, "Unknown part number: 0x%x\n", part);
reg = readl_relaxed(cfg_region + CMN_CFGM_PERIPH_ID_23);
cmn->rev = FIELD_GET(CMN_CFGM_PID2_REVISION, reg);
+ model = arm_cmn_model(cmn);
+ if (!model)
+ dev_warn(cmn->dev, "Unknown part number: 0x%x\n", part);
+
/*
* With the device isolation feature, if firmware has neglected to enable
* an XP port then we risk locking up if we try to access anything behind
@@ -2500,6 +2558,11 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset)
dev_err(cmn->dev, "Node ID invalid for supported CMN versions: %d\n", dn->logid);
return -ENODEV;
}
+ /*
+ * We can utilise the "wasted" filter array slot to store
+ * the index for referencing the filter encodings later.
+ */
+ dn->filter[SEL_NONE].val = arm_cmn_filter(dn->type, model);
switch (dn->type) {
case CMN_TYPE_DTC:
--
2.54.0.dirty
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