Re: [PATCH v4 2/2] drivers/perf: hisi: Add Support for CPA PMU

From: liuqi (BA)
Date: Thu Apr 07 2022 - 21:47:52 EST




On 2022/4/7 21:10, John Garry wrote:
On 07/04/2022 13:46, Qi Liu wrote:
On HiSilicon Hip09 platform, there is a CPA (Coherency Protocol Agent) on
each SICL (Super I/O Cluster) which implements packet format translation,
route parsing and traffic statistics.

CPA PMU has 8 PMU counters and interrupt is supported to handle counter
overflow. Let's support its driver under the framework of HiSilicon PMU
driver.

Signed-off-by: Qi Liu <liuqi115@xxxxxxxxxx>

This looks ok, but I still have a few nitpicks. Regardless,

Reviewed-by: John Garry <john.garry@xxxxxxxxxx>


Hi John,

Thanks for the comments. some replies inline.

---
  drivers/perf/hisilicon/Makefile              |   2 +-
  drivers/perf/hisilicon/hisi_uncore_cpa_pmu.c | 401 +++++++++++++++++++
  include/linux/cpuhotplug.h                   |   1 +
  3 files changed, 403 insertions(+), 1 deletion(-)
  create mode 100644 drivers/perf/hisilicon/hisi_uncore_cpa_pmu.c

diff --git a/drivers/perf/hisilicon/Makefile b/drivers/perf/hisilicon/Makefile
index 506ed39e3266..6be83517acaa 100644
--- a/drivers/perf/hisilicon/Makefile
+++ b/drivers/perf/hisilicon/Makefile
@@ -1,6 +1,6 @@
  # SPDX-License-Identifier: GPL-2.0-only
  obj-$(CONFIG_HISI_PMU) += hisi_uncore_pmu.o hisi_uncore_l3c_pmu.o \
                hisi_uncore_hha_pmu.o hisi_uncore_ddrc_pmu.o hisi_uncore_sllc_pmu.o \
-              hisi_uncore_pa_pmu.o
+              hisi_uncore_pa_pmu.o hisi_uncore_cpa_pmu.o
  obj-$(CONFIG_HISI_PCIE_PMU) += hisi_pcie_pmu.o
diff --git a/drivers/perf/hisilicon/hisi_uncore_cpa_pmu.c b/drivers/perf/hisilicon/hisi_uncore_cpa_pmu.c
new file mode 100644
index 000000000000..d6b8e4037076
--- /dev/null
+++ b/drivers/perf/hisilicon/hisi_uncore_cpa_pmu.c
@@ -0,0 +1,401 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * HiSilicon SoC CPA(Coherency Protocol Agent) hardware event counters support
+ *
+ * Copyright (C) 2022 HiSilicon Limited
+ * Author: Qi Liu <liuqi115@xxxxxxxxxx>
+ *
+ * This code is based on the uncore PMUs like arm-cci and arm-ccn.
+ */
+
+#define pr_fmt(fmt) "cpa pmu: " fmt

comment: you could add "hisi" but maybe it becomes too long

yes, so we'll keep "cpa pmu" here, thanks.
+#include <linux/acpi.h>
+#include <linux/bug.h>
+#include <linux/cpuhotplug.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/list.h>
+#include <linux/smp.h>
+
+#include "hisi_uncore_pmu.h"
+
+/* CPA register definition */
+#define CPA_PERF_CTRL        0x1c00
+#define CPA_EVENT_CTRL        0x1c04
+#define CPA_INT_MASK        0x1c70
+#define CPA_INT_STATUS        0x1c78
+#define CPA_INT_CLEAR        0x1c7c
+#define CPA_EVENT_TYPE0        0x1c80
+#define CPA_VERSION        0x1cf0
+#define CPA_CNT0_LOWER        0x1d00
+#define CPA_CFG_REG        0x0534
+
+/* CPA operation command */
+#define CPA_PERF_CTRL_EN    BIT_ULL(0)
+#define CPA_EVTYPE_MASK        0xffUL
+#define CPA_PM_CTRL        BIT_ULL(9)
+
+/* CPA has 8-counters */
+#define CPA_NR_COUNTERS        0x8
+#define CPA_COUNTER_BITS    64
+#define CPA_NR_EVENTS        0xff
+#define CPA_REG_OFFSET        0x8
+

[...]
+static int hisi_cpa_pmu_probe(struct platform_device *pdev)
+{
+    struct hisi_pmu *cpa_pmu;
+    char *name;
+    int ret;
+
+    cpa_pmu = devm_kzalloc(&pdev->dev, sizeof(*cpa_pmu), GFP_KERNEL);
+    if (!cpa_pmu)
+        return -ENOMEM;
+
+    ret = hisi_cpa_pmu_dev_probe(pdev, cpa_pmu);
+    if (ret)
+        return ret;
+
+    /* Power Management should be disabled before using CPA PMU. */
+    hisi_cpa_pmu_disable_pm(cpa_pmu);
+

nit: we call hisi_cpa_pmu_enable_pm() in the remove function to restore to the same state as we had before loading the driver. However we don't do the same for a failed probe later.

thanks, I'll add this next version.

+    ret = cpuhp_state_add_instance(CPUHP_AP_PERF_ARM_HISI_CPA_ONLINE,
+                       &cpa_pmu->node);
+    if (ret) {
+        dev_err(&pdev->dev, "Error %d registering hotplug\n", ret);
+        return ret;
+    }
+
+    name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "hisi_sicl%d_cpa%u", cpa_pmu->sicl_id,
+                  cpa_pmu->index_id);

nit: should check non-NULL here

got it, will add this, thanks.
Qi
+
+    cpa_pmu->pmu = (struct pmu) {
+        .name        = name,
+        .module        = THIS_MODULE,
+        .task_ctx_nr    = perf_invalid_context,
+        .event_init    = hisi_uncore_pmu_event_init,
+        .pmu_enable    = hisi_uncore_pmu_enable,
+        .pmu_disable    = hisi_uncore_pmu_disable,
+        .add        = hisi_uncore_pmu_add,
+        .del        = hisi_uncore_pmu_del,
+        .start        = hisi_uncore_pmu_start,
+        .stop        = hisi_uncore_pmu_stop,
+        .read        = hisi_uncore_pmu_read,
+        .attr_groups    = cpa_pmu->pmu_events.attr_groups,
+        .capabilities    = PERF_PMU_CAP_NO_EXCLUDE,
+    };
+
+    ret = perf_pmu_register(&cpa_pmu->pmu, name, -1);
+    if (ret) {
+        dev_err(cpa_pmu->dev, "PMU register failed\n");
+        cpuhp_state_remove_instance_nocalls(
+            CPUHP_AP_PERF_ARM_HISI_CPA_ONLINE, &cpa_pmu->node);
+        return ret;
+    }
+
+    platform_set_drvdata(pdev, cpa_pmu);
+    return ret;
+}
+
+static int hisi_cpa_pmu_remove(struct platform_device *pdev)
+{
+    struct hisi_pmu *cpa_pmu = platform_get_drvdata(pdev);
+
+    perf_pmu_unregister(&cpa_pmu->pmu);
+ cpuhp_state_remove_instance_nocalls(CPUHP_AP_PERF_ARM_HISI_CPA_ONLINE,
+                        &cpa_pmu->node);
+    hisi_cpa_pmu_enable_pm(cpa_pmu);
+    return 0;
+}
+
+static struct platform_driver hisi_cpa_pmu_driver = {
+    .driver = {
+        .name = "hisi_cpa_pmu",
+        .acpi_match_table = ACPI_PTR(hisi_cpa_pmu_acpi_match),
+        .suppress_bind_attrs = true,
+    },
+    .probe = hisi_cpa_pmu_probe,
+    .remove = hisi_cpa_pmu_remove,
+};
+
+static int __init hisi_cpa_pmu_module_init(void)
+{
+    int ret;
+
+    ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_HISI_CPA_ONLINE,
+                      "AP_PERF_ARM_HISI_CPA_ONLINE",
+                      hisi_uncore_pmu_online_cpu,
+                      hisi_uncore_pmu_offline_cpu);
+    if (ret) {
+        pr_err("setup hotplug failed: %d\n", ret);
+        return ret;
+    }
+
+    ret = platform_driver_register(&hisi_cpa_pmu_driver);
+    if (ret)
+        cpuhp_remove_multi_state(CPUHP_AP_PERF_ARM_HISI_CPA_ONLINE);
+
+    return ret;
+}
+module_init(hisi_cpa_pmu_module_init);
+
+static void __exit hisi_cpa_pmu_module_exit(void)
+{
+    platform_driver_unregister(&hisi_cpa_pmu_driver);
+    cpuhp_remove_multi_state(CPUHP_AP_PERF_ARM_HISI_CPA_ONLINE);
+}
+module_exit(hisi_cpa_pmu_module_exit);
+
+MODULE_DESCRIPTION("HiSilicon SoC CPA uncore PMU driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Qi Liu <liuqi115@xxxxxxxxxx>");
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 411a428ace4d..d55063719904 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -220,6 +220,7 @@ enum cpuhp_state {
      CPUHP_AP_PERF_S390_SF_ONLINE,
      CPUHP_AP_PERF_ARM_CCI_ONLINE,
      CPUHP_AP_PERF_ARM_CCN_ONLINE,
+    CPUHP_AP_PERF_ARM_HISI_CPA_ONLINE,
      CPUHP_AP_PERF_ARM_HISI_DDRC_ONLINE,
      CPUHP_AP_PERF_ARM_HISI_HHA_ONLINE,
      CPUHP_AP_PERF_ARM_HISI_L3_ONLINE,

.