Re: [PATCH v3 1/2] drivers/perf: hisi: Associate PMUs in SICL with CPUs online

From: John Garry
Date: Tue Apr 05 2022 - 05:51:36 EST


On 21/03/2022 07:01, Qi Liu wrote:
If a PMU is in SICL, we associate it with all CPUs online, rather

/s/in SICL/in a SICL/ [and all other places, including the code change], or maybe it is better mention "IO super cluster" as well for people who would not know or remember.

than CPUs in the nearest SCCL.

You are not really saying why. I would mention that we do it as it is not appropiate to associate with a CPU die, and you can also mention problems that associating with a SICL creates.

Please also mention how changing FW definition is ok at this stage.


Signed-off-by: Qi Liu <liuqi115@xxxxxxxxxx>
---
drivers/perf/hisilicon/hisi_uncore_pa_pmu.c | 18 +++++++-----------
drivers/perf/hisilicon/hisi_uncore_pmu.c | 4 ++++
drivers/perf/hisilicon/hisi_uncore_pmu.h | 1 +
3 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/perf/hisilicon/hisi_uncore_pa_pmu.c b/drivers/perf/hisilicon/hisi_uncore_pa_pmu.c
index bad99d149172..54c604c0d404 100644
--- a/drivers/perf/hisilicon/hisi_uncore_pa_pmu.c
+++ b/drivers/perf/hisilicon/hisi_uncore_pa_pmu.c
@@ -258,13 +258,12 @@ static int hisi_pa_pmu_init_data(struct platform_device *pdev,
struct hisi_pmu *pa_pmu)
{
/*
- * Use the SCCL_ID and the index ID to identify the PA PMU,
- * while SCCL_ID is the nearst SCCL_ID from this SICL and
- * CPU core is chosen from this SCCL to manage this PMU.
+ * As PA PMU is in SICL, use the SICL_ID and the index ID

"a SICL"

+ * to identify the PA PMU.
*/
if (device_property_read_u32(&pdev->dev, "hisilicon,scl-id",
- &pa_pmu->sccl_id)) {
- dev_err(&pdev->dev, "Cannot read sccl-id!\n");
+ &pa_pmu->sicl_id)) {
+ dev_err(&pdev->dev, "Cannot read sicl-id!\n");
return -EINVAL;
}
@@ -275,6 +274,7 @@ static int hisi_pa_pmu_init_data(struct platform_device *pdev,
}
pa_pmu->ccl_id = -1;
+ pa_pmu->sccl_id = -1;
pa_pmu->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(pa_pmu->base)) {
@@ -399,13 +399,9 @@ static int hisi_pa_pmu_probe(struct platform_device *pdev)
ret = hisi_pa_pmu_dev_probe(pdev, pa_pmu);
if (ret)
return ret;
- /*
- * PA is attached in SICL and the CPU core is chosen to manage this
- * PMU which is the nearest SCCL, while its SCCL_ID is greater than
- * one with the SICL_ID.
- */
+
name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "hisi_sicl%u_pa%u",
- pa_pmu->sccl_id - 1, pa_pmu->index_id);
+ pa_pmu->sicl_id, pa_pmu->index_id);
if (!name)
return -ENOMEM;
diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.c b/drivers/perf/hisilicon/hisi_uncore_pmu.c
index a738aeab5c04..31930166c34b 100644
--- a/drivers/perf/hisilicon/hisi_uncore_pmu.c
+++ b/drivers/perf/hisilicon/hisi_uncore_pmu.c
@@ -458,6 +458,10 @@ static bool hisi_pmu_cpu_is_associated_pmu(struct hisi_pmu *hisi_pmu)
{
int sccl_id, ccl_id;
+ /* If SCCL_ID is -1, the PMU is in SICL and can be associated this PMU with any CPU */

too long, just have "The PMU is in a SICL and has no CPU affinity"

+ if (hisi_pmu->sccl_id == -1)
+ return true;
+
if (hisi_pmu->ccl_id == -1) {
/* If CCL_ID is -1, the PMU only shares the same SCCL */
hisi_read_sccl_and_ccl_id(&sccl_id, NULL);
diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.h b/drivers/perf/hisilicon/hisi_uncore_pmu.h
index 7f5841d6f592..96eeddad55ff 100644
--- a/drivers/perf/hisilicon/hisi_uncore_pmu.h
+++ b/drivers/perf/hisilicon/hisi_uncore_pmu.h
@@ -81,6 +81,7 @@ struct hisi_pmu {
struct device *dev;
struct hlist_node node;
int sccl_id;
+ int sicl_id;
int ccl_id;
void __iomem *base;
/* the ID of the PMU modules */