[PATCH 3/5] perf/arm-cmn: Refactor event filter data

Robin Murphy robin.murphy at arm.com
Tue Jun 30 08:19:18 PDT 2026


The ABI hole I have dug myself into requires the driver to know which
event encodings are associated with which particular filter control.
Since we will soon have a notion of multiple filters per event, refactor
the event data to encapsulate filters in an explicit structure, which
can then more easily scale as an array in future.

Signed-off-by: Robin Murphy <robin.murphy at arm.com>
---
 drivers/perf/arm-cmn.c | 95 ++++++++++++++++++++++--------------------
 1 file changed, 49 insertions(+), 46 deletions(-)

diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
index 14c267d2e2f9..4ba78df87045 100644
--- a/drivers/perf/arm-cmn.c
+++ b/drivers/perf/arm-cmn.c
@@ -717,13 +717,17 @@ static void arm_cmn_clear_idx(struct arm_cmn_hw_event *hw)
 		bitmap_zero(hw->wp_idx, CMN_MAX_XPS);
 }
 
+struct arm_cmn_filter_attr {
+	enum cmn_filter_select sel;
+	u8 val;
+};
+
 struct arm_cmn_event_attr {
 	struct device_attribute attr;
 	enum cmn_model model;
 	enum cmn_node_type type;
-	enum cmn_filter_select fsel;
 	u16 eventid;
-	u8 filter;
+	struct arm_cmn_filter_attr filter[1];
 };
 
 struct arm_cmn_format_attr {
@@ -732,24 +736,25 @@ struct arm_cmn_format_attr {
 	int config;
 };
 
-#define _CMN_EVENT_ATTR(_model, _name, _type, _eventid, _filter, _fsel)\
+#define _CMN_EVENT_ATTR(_model, _name, _type, _eventid, _filter, ...)	\
 	(&((struct arm_cmn_event_attr[]) {{				\
 		.attr = __ATTR(_name, 0444, arm_cmn_event_show, NULL),	\
 		.model = _model,					\
 		.type = _type,						\
 		.eventid = _eventid,					\
-		.filter = _filter,					\
-		.fsel = _fsel,						\
+		.filter = {{_filter}},					\
 	}})[0].attr.attr)
-#define CMN_EVENT_ATTR(_model, _name, _type, _eventid)			\
-	_CMN_EVENT_ATTR(_model, _name, _type, _eventid, 0, SEL_NONE)
+#define CMN_EVENT_ATTR(_model, _name, _type, _eventid, _filter...)	\
+	_CMN_EVENT_ATTR(_model, _name, _type, _eventid, ##_filter, 0, 0)
 
 static ssize_t arm_cmn_event_show(struct device *dev,
 				  struct device_attribute *attr, char *buf)
 {
 	struct arm_cmn_event_attr *eattr;
+	struct arm_cmn_filter_attr *filter;
 
 	eattr = container_of(attr, typeof(*eattr), attr);
+	filter = eattr->filter;
 
 	if (eattr->type == CMN_TYPE_DTC)
 		return sysfs_emit(buf, "type=0x%x\n", eattr->type);
@@ -759,9 +764,9 @@ 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)
+	if (filter[0].sel)
 		return sysfs_emit(buf, "type=0x%x,eventid=0x%x,filter=0x%x\n",
-				  eattr->type, eattr->eventid, eattr->filter);
+				  eattr->type, eattr->eventid, filter[0].val);
 
 	return sysfs_emit(buf, "type=0x%x,eventid=0x%x\n", eattr->type,
 			  eattr->eventid);
@@ -849,8 +854,8 @@ static umode_t arm_cmn_event_attr_is_visible(struct kobject *kobj,
 	return attr->mode;
 }
 
-#define _CMN_EVENT_DVM(_model, _name, _event, _occup, _fsel)	\
-	_CMN_EVENT_ATTR(_model, dn_##_name, CMN_TYPE_DVM, _event, _occup, _fsel)
+#define CMN_EVENT_DVM(_model, _name, _event, _filter...)	\
+	CMN_EVENT_ATTR(_model, dn_##_name, CMN_TYPE_DVM, _event, ##_filter)
 #define CMN_EVENT_DTC(_name)					\
 	CMN_EVENT_ATTR(CMN_ANY, dtc_##_name, CMN_TYPE_DTC, 0)
 #define CMN_EVENT_HNF(_model, _name, _event)			\
@@ -880,32 +885,30 @@ static umode_t arm_cmn_event_attr_is_visible(struct kobject *kobj,
 #define CMN_EVENT_HNS(_name, _event)				\
 	CMN_EVENT_ATTR(CMN_ANY, hns_##_name, CMN_TYPE_HNS, _event)
 
-#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_OCCUP1_ID),	\
-	_CMN_EVENT_DVM(_model, _name##_dvmop, _event, 1, SEL_OCCUP1_ID),	\
-	_CMN_EVENT_DVM(_model, _name##_dvmsync, _event, 2, SEL_OCCUP1_ID)
+	CMN_EVENT_DVM(_model, _name##_all, _event, SEL_OCCUP1_ID, 0),	\
+	CMN_EVENT_DVM(_model, _name##_dvmop, _event, SEL_OCCUP1_ID, 1),	\
+	CMN_EVENT_DVM(_model, _name##_dvmsync, _event, SEL_OCCUP1_ID, 2)
 
 #define CMN_EVENT_HN_OCC(_model, _name, _type, _event)		\
-	_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)
+	CMN_EVENT_ATTR(_model, _name##_all, _type, _event, SEL_OCCUP1_ID, 0), \
+	CMN_EVENT_ATTR(_model, _name##_read, _type, _event, SEL_OCCUP1_ID, 1), \
+	CMN_EVENT_ATTR(_model, _name##_write, _type, _event, SEL_OCCUP1_ID, 2), \
+	CMN_EVENT_ATTR(_model, _name##_atomic, _type, _event, SEL_OCCUP1_ID, 3), \
+	CMN_EVENT_ATTR(_model, _name##_stash, _type, _event, SEL_OCCUP1_ID, 4)
 #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), \
-	_CMN_EVENT_ATTR(_model, _name##_class2, _type, _event, 2, SEL_CLASS_OCCUP_ID), \
-	_CMN_EVENT_ATTR(_model, _name##_class3, _type, _event, 3, SEL_CLASS_OCCUP_ID)
+	CMN_EVENT_ATTR(_model, _name##_class0, _type, _event, SEL_CLASS_OCCUP_ID, 0), \
+	CMN_EVENT_ATTR(_model, _name##_class1, _type, _event, SEL_CLASS_OCCUP_ID, 1), \
+	CMN_EVENT_ATTR(_model, _name##_class2, _type, _event, SEL_CLASS_OCCUP_ID, 2), \
+	CMN_EVENT_ATTR(_model, _name##_class3, _type, _event, SEL_CLASS_OCCUP_ID, 3)
 #define CMN_EVENT_HN_SNT(_model, _name, _type, _event)			\
-	_CMN_EVENT_ATTR(_model, _name##_all, _type, _event, 0, SEL_CBUSY_SNTHROTTLE_SEL), \
-	_CMN_EVENT_ATTR(_model, _name##_group0_read, _type, _event, 1, SEL_CBUSY_SNTHROTTLE_SEL), \
-	_CMN_EVENT_ATTR(_model, _name##_group0_write, _type, _event, 2, SEL_CBUSY_SNTHROTTLE_SEL), \
-	_CMN_EVENT_ATTR(_model, _name##_group1_read, _type, _event, 3, SEL_CBUSY_SNTHROTTLE_SEL), \
-	_CMN_EVENT_ATTR(_model, _name##_group1_write, _type, _event, 4, SEL_CBUSY_SNTHROTTLE_SEL), \
-	_CMN_EVENT_ATTR(_model, _name##_read, _type, _event, 5, SEL_CBUSY_SNTHROTTLE_SEL), \
-	_CMN_EVENT_ATTR(_model, _name##_write, _type, _event, 6, SEL_CBUSY_SNTHROTTLE_SEL)
+	CMN_EVENT_ATTR(_model, _name##_all, _type, _event, SEL_CBUSY_SNTHROTTLE_SEL, 0), \
+	CMN_EVENT_ATTR(_model, _name##_group0_read, _type, _event, SEL_CBUSY_SNTHROTTLE_SEL, 1), \
+	CMN_EVENT_ATTR(_model, _name##_group0_write, _type, _event, SEL_CBUSY_SNTHROTTLE_SEL, 2), \
+	CMN_EVENT_ATTR(_model, _name##_group1_read, _type, _event, SEL_CBUSY_SNTHROTTLE_SEL, 3), \
+	CMN_EVENT_ATTR(_model, _name##_group1_write, _type, _event, SEL_CBUSY_SNTHROTTLE_SEL, 4), \
+	CMN_EVENT_ATTR(_model, _name##_read, _type, _event, SEL_CBUSY_SNTHROTTLE_SEL, 5), \
+	CMN_EVENT_ATTR(_model, _name##_write, _type, _event, SEL_CBUSY_SNTHROTTLE_SEL, 6)
 
 #define CMN_EVENT_HNF_OCC(_model, _name, _event)			\
 	CMN_EVENT_HN_OCC(_model, hnf_##_name, CMN_TYPE_HNF, _event)
@@ -916,21 +919,21 @@ 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_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)
+	CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_rxsnp, CMN_TYPE_HNS, _event, SEL_OCCUP1_ID, 5), \
+	CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_lbt, CMN_TYPE_HNS, _event, SEL_OCCUP1_ID, 6), \
+	CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_hbt, CMN_TYPE_HNS, _event, SEL_OCCUP1_ID, 7)
 #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)				\
 	CMN_EVENT_HN_SNT(CMN_ANY, hns_##_name, CMN_TYPE_HNS, _event)
 #define CMN_EVENT_HNS_HBT(_name, _event)				\
-	_CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_all, CMN_TYPE_HNS, _event, 0, SEL_HBT_LBT_SEL), \
-	_CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_hbt, CMN_TYPE_HNS, _event, 1, SEL_HBT_LBT_SEL), \
-	_CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_lbt, CMN_TYPE_HNS, _event, 2, SEL_HBT_LBT_SEL)
+	CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_all, CMN_TYPE_HNS, _event, SEL_HBT_LBT_SEL, 0), \
+	CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_hbt, CMN_TYPE_HNS, _event, SEL_HBT_LBT_SEL, 1), \
+	CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_lbt, CMN_TYPE_HNS, _event, SEL_HBT_LBT_SEL, 2)
 #define CMN_EVENT_HNS_SNH(_name, _event)				\
-	_CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_all, CMN_TYPE_HNS, _event, 0, SEL_SN_HOME_SEL), \
-	_CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_sn, CMN_TYPE_HNS, _event, 1, SEL_SN_HOME_SEL), \
-	_CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_home, CMN_TYPE_HNS, _event, 2, SEL_SN_HOME_SEL)
+	CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_all, CMN_TYPE_HNS, _event, SEL_SN_HOME_SEL, 0), \
+	CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_sn, CMN_TYPE_HNS, _event, SEL_SN_HOME_SEL, 1), \
+	CMN_EVENT_ATTR(CMN_ANY, hns_##_name##_home, CMN_TYPE_HNS, _event, SEL_SN_HOME_SEL, 2)
 
 #define _CMN_EVENT_XP_MESH(_name, _event)			\
 	__CMN_EVENT_XP(e_##_name, (_event) | (0 << 2)),		\
@@ -1814,9 +1817,9 @@ static int arm_cmn_validate_group(struct arm_cmn *cmn, struct perf_event *event)
 	return ret;
 }
 
-static enum cmn_filter_select arm_cmn_filter_sel(const struct arm_cmn *cmn,
-						 enum cmn_node_type type,
-						 unsigned int eventid)
+static enum cmn_filter_select arm_cmn_event_filter(const struct arm_cmn *cmn,
+						   enum cmn_node_type type,
+						   unsigned int eventid)
 {
 	struct arm_cmn_event_attr *e;
 	enum cmn_model model = arm_cmn_model(cmn);
@@ -1824,7 +1827,7 @@ static enum cmn_filter_select arm_cmn_filter_sel(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->fsel;
+			return e->filter[0].sel;
 	}
 	return SEL_NONE;
 }
@@ -1889,7 +1892,7 @@ static int arm_cmn_event_init(struct perf_event *event)
 	}
 
 	/* This is sufficiently annoying to recalculate, so cache it */
-	hw->filter_sel = arm_cmn_filter_sel(cmn, type, eventid);
+	hw->filter_sel = arm_cmn_event_filter(cmn, type, eventid);
 
 	bynodeid = CMN_EVENT_BYNODEID(event);
 	nodeid = CMN_EVENT_NODEID(event);
-- 
2.54.0.dirty




More information about the linux-arm-kernel mailing list