perf: arm_spe: Add support for filtering on data source

SPE_FEAT_FDS adds the ability to filter on the data source of packets.
Like the other existing filters, enable filtering with PMSFCR_EL1.FDS
when any of the filter bits are set.

Each bit position of the 64 bit filter maps to numerical data sources
0-63 described by bits[0:5] in the data source packet (although the full
range of data source is 16 bits so higher value data sources can't be
filtered on). The filter is an OR of all the filter bits, so for example
clearing filter bits 0 and 3 only includes packets from data sources 0
OR 3.

Invert the filter given by userspace so that the default value of 0 is
equivalent to including all values (no filtering). This allows us to
skip adding a new format bit to enable filtering and still support
excluding all data sources which would have been a filter value of 0 if
not for the inversion.

Tested-by: Leo Yan <leo.yan@arm.com>
Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 37 insertions, 0 deletions

diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c
index fa50645fedda..617f8a98dd63 100644
--- a/drivers/perf/arm_spe_pmu.c
+++ b/drivers/perf/arm_spe_pmu.c
@@ -87,6 +87,7 @@ struct arm_spe_pmu {
 #define SPE_PMU_FEAT_INV_FILT_EVT		(1UL << 6)
 #define SPE_PMU_FEAT_DISCARD			(1UL << 7)
 #define SPE_PMU_FEAT_EFT			(1UL << 8)
+#define SPE_PMU_FEAT_FDS			(1UL << 9)
 #define SPE_PMU_FEAT_DEV_PROBED			(1UL << 63)
 	u64					features;
 
@@ -252,6 +253,10 @@ static const struct attribute_group arm_spe_pmu_cap_group = {
 #define ATTR_CFG_FLD_inv_event_filter_LO	0
 #define ATTR_CFG_FLD_inv_event_filter_HI	63
 
+#define ATTR_CFG_FLD_inv_data_src_filter_CFG	config4	/* inverse of PMSDSFR_EL1 */
+#define ATTR_CFG_FLD_inv_data_src_filter_LO	0
+#define ATTR_CFG_FLD_inv_data_src_filter_HI	63
+
 GEN_PMU_FORMAT_ATTR(ts_enable);
 GEN_PMU_FORMAT_ATTR(pa_enable);
 GEN_PMU_FORMAT_ATTR(pct_enable);
@@ -268,6 +273,7 @@ GEN_PMU_FORMAT_ATTR(float_filter);
 GEN_PMU_FORMAT_ATTR(float_filter_mask);
 GEN_PMU_FORMAT_ATTR(event_filter);
 GEN_PMU_FORMAT_ATTR(inv_event_filter);
+GEN_PMU_FORMAT_ATTR(inv_data_src_filter);
 GEN_PMU_FORMAT_ATTR(min_latency);
 GEN_PMU_FORMAT_ATTR(discard);
 
@@ -288,6 +294,7 @@ static struct attribute *arm_spe_pmu_formats_attr[] = {
 	&format_attr_float_filter_mask.attr,
 	&format_attr_event_filter.attr,
 	&format_attr_inv_event_filter.attr,
+	&format_attr_inv_data_src_filter.attr,
 	&format_attr_min_latency.attr,
 	&format_attr_discard.attr,
 	NULL,
@@ -306,6 +313,10 @@ static umode_t arm_spe_pmu_format_attr_is_visible(struct kobject *kobj,
 	if (attr == &format_attr_inv_event_filter.attr && !(spe_pmu->features & SPE_PMU_FEAT_INV_FILT_EVT))
 		return 0;
 
+	if (attr == &format_attr_inv_data_src_filter.attr &&
+	    !(spe_pmu->features & SPE_PMU_FEAT_FDS))
+		return 0;
+
 	if ((attr == &format_attr_branch_filter_mask.attr ||
 	     attr == &format_attr_load_filter_mask.attr ||
 	     attr == &format_attr_store_filter_mask.attr ||
@@ -430,6 +441,9 @@ static u64 arm_spe_event_to_pmsfcr(struct perf_event *event)
 	if (ATTR_CFG_GET_FLD(attr, inv_event_filter))
 		reg |= PMSFCR_EL1_FnE;
 
+	if (ATTR_CFG_GET_FLD(attr, inv_data_src_filter))
+		reg |= PMSFCR_EL1_FDS;
+
 	if (ATTR_CFG_GET_FLD(attr, min_latency))
 		reg |= PMSFCR_EL1_FL;
 
@@ -454,6 +468,17 @@ static u64 arm_spe_event_to_pmslatfr(struct perf_event *event)
 	return FIELD_PREP(PMSLATFR_EL1_MINLAT, ATTR_CFG_GET_FLD(attr, min_latency));
 }
 
+static u64 arm_spe_event_to_pmsdsfr(struct perf_event *event)
+{
+	struct perf_event_attr *attr = &event->attr;
+
+	/*
+	 * Data src filter is inverted so that the default value of 0 is
+	 * equivalent to no filtering.
+	 */
+	return ~ATTR_CFG_GET_FLD(attr, inv_data_src_filter);
+}
+
 static void arm_spe_pmu_pad_buf(struct perf_output_handle *handle, int len)
 {
 	struct arm_spe_pmu_buf *buf = perf_get_aux(handle);
@@ -791,6 +816,10 @@ static int arm_spe_pmu_event_init(struct perf_event *event)
 	if (arm_spe_event_to_pmsnevfr(event) & spe_pmu->pmsevfr_res0)
 		return -EOPNOTSUPP;
 
+	if (arm_spe_event_to_pmsdsfr(event) != U64_MAX &&
+	    !(spe_pmu->features & SPE_PMU_FEAT_FDS))
+		return -EOPNOTSUPP;
+
 	if (attr->exclude_idle)
 		return -EOPNOTSUPP;
 
@@ -866,6 +895,11 @@ static void arm_spe_pmu_start(struct perf_event *event, int flags)
 		write_sysreg_s(reg, SYS_PMSNEVFR_EL1);
 	}
 
+	if (spe_pmu->features & SPE_PMU_FEAT_FDS) {
+		reg = arm_spe_event_to_pmsdsfr(event);
+		write_sysreg_s(reg, SYS_PMSDSFR_EL1);
+	}
+
 	reg = arm_spe_event_to_pmslatfr(event);
 	write_sysreg_s(reg, SYS_PMSLATFR_EL1);
 
@@ -1125,6 +1159,9 @@ static void __arm_spe_pmu_dev_probe(void *info)
 	if (FIELD_GET(PMSIDR_EL1_EFT, reg))
 		spe_pmu->features |= SPE_PMU_FEAT_EFT;
 
+	if (FIELD_GET(PMSIDR_EL1_FDS, reg))
+		spe_pmu->features |= SPE_PMU_FEAT_FDS;
+
 	/* This field has a spaced out encoding, so just use a look-up */
 	fld = FIELD_GET(PMSIDR_EL1_INTERVAL, reg);
 	switch (fld) {