perf/arm_dmc620: Add cpumask

Add a cpumask for the DMC620 PMU. As it is an uncore PMU, perf
userspace tool only needs to open a single counter on the CPU
specified by the CPU mask for each event on a given DMC620 device.

Signed-off-by: Xin Yang <xin.yang@arm.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20230613013423.2078397-1-xin.yang@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/perf/arm_dmc620_pmu.c b/drivers/perf/arm_dmc620_pmu.c
index 5de06f9..9d0f01c 100644 (file)
--- a/drivers/perf/arm_dmc620_pmu.c
+++ b/drivers/perf/arm_dmc620_pmu.c
@@ -227,9 +227,31 @@ static const struct attribute_group dmc620_pmu_format_attr_group = {
        .attrs  = dmc620_pmu_formats_attrs,
 };
 
+static ssize_t dmc620_pmu_cpumask_show(struct device *dev,
+                                      struct device_attribute *attr, char *buf)
+{
+       struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(dev_get_drvdata(dev));
+
+       return cpumap_print_to_pagebuf(true, buf,
+                                      cpumask_of(dmc620_pmu->irq->cpu));
+}
+
+static struct device_attribute dmc620_pmu_cpumask_attr =
+       __ATTR(cpumask, 0444, dmc620_pmu_cpumask_show, NULL);
+
+static struct attribute *dmc620_pmu_cpumask_attrs[] = {
+       &dmc620_pmu_cpumask_attr.attr,
+       NULL,
+};
+
+static const struct attribute_group dmc620_pmu_cpumask_attr_group = {
+       .attrs = dmc620_pmu_cpumask_attrs,
+};
+
 static const struct attribute_group *dmc620_pmu_attr_groups[] = {
        &dmc620_pmu_events_attr_group,
        &dmc620_pmu_format_attr_group,
+       &dmc620_pmu_cpumask_attr_group,
        NULL,
 };