On 2025/9/24 19:19, Will Deacon wrote:

On Tue, Sep 23, 2025 at 03:31:15PM +0800, Yicong Yang wrote:

quoted

diff --git a/drivers/perf/hisilicon/hisi_uncore_l3c_pmu.c b/drivers/perf/hisilicon/hisi_uncore_l3c_pmu.c
index bbd81a43047d..a52d98f1ed34 100644
--- a/drivers/perf/hisilicon/hisi_uncore_l3c_pmu.c
+++ b/drivers/perf/hisilicon/hisi_uncore_l3c_pmu.c

@@ -57,6 +57,11 @@
 #define L3C_V2_NR_EVENTS	0xFF

 HISI_PMU_EVENT_ATTR_EXTRACTOR(ext, config, 17, 16);
+/*
+ * Remain the config1:0-7 for backward compatibility if some existing users
+ * hardcode the config1:0-7 directly without parsing the sysfs attribute.
+ */
+HISI_PMU_EVENT_ATTR_EXTRACTOR(tt_core_deprecated, config1, 7, 0);
 HISI_PMU_EVENT_ATTR_EXTRACTOR(tt_req, config1, 10, 8);
 HISI_PMU_EVENT_ATTR_EXTRACTOR(datasrc_cfg, config1, 15, 11);
 HISI_PMU_EVENT_ATTR_EXTRACTOR(datasrc_skt, config1, 16, 16);

@@ -95,6 +100,21 @@ static bool support_ext(struct hisi_l3c_pmu *pmu)
 	return l3c_pmu_ext->support_ext;
 }

+/*
+ * tt_core was extended to cover all the CPUs sharing the L3 and was moved from
+ * config1:0-7 to config2:0-*. Try it first and fallback to tt_core_deprecated
+ * if user's still using the deprecated one.
+ */
+static u32 hisi_l3c_pmu_get_tt_core(struct perf_event *event)
+{
+	u32 core = hisi_get_tt_core(event);
+
+	if (core)
+		return core;
+
+	return hisi_get_tt_core_deprecated(event);
+}

Perhaps we should be stricter about this and fail validation for events
that specify both a non-zero tt_core and a non-zero tt_core_deprecated?

added in hisi_uncore_l3c_ops->check_filter() that hisi_uncore_pmu_event_init() will
call check_filter() to ask uncore pmu to validate the filter configuration.

https://lore.kernel.org/linux-arm-kernel/20250925033123.5836-1-yangyicong@huawei.com/ (local)

thanks.