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

From: John Garry
Date: Thu Apr 07 2022 - 09:11:35 EST


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>

---
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

+#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 u32 hisi_cpa_pmu_get_counter_offset(int idx)
+{
+ return (CPA_CNT0_LOWER + idx * CPA_REG_OFFSET);
+}
+
+static u64 hisi_cpa_pmu_read_counter(struct hisi_pmu *cpa_pmu,
+ struct hw_perf_event *hwc)
+{
+ return readq(cpa_pmu->base + hisi_cpa_pmu_get_counter_offset(hwc->idx));
+}
+
+static void hisi_cpa_pmu_write_counter(struct hisi_pmu *cpa_pmu,
+ struct hw_perf_event *hwc, u64 val)
+{
+ writeq(val, cpa_pmu->base + hisi_cpa_pmu_get_counter_offset(hwc->idx));
+}
+
+static void hisi_cpa_pmu_write_evtype(struct hisi_pmu *cpa_pmu, int idx, u32 type)
+{
+ u32 reg, reg_idx, shift, val;
+
+ /*
+ * Select the appropriate event select register(CPA_EVENT_TYPE0/1).
+ * There are 2 event select registers for the 8 hardware counters.
+ * Event code is 8-bits and for the former 4 hardware counters,
+ * CPA_EVENT_TYPE0 is chosen. For the latter 4 hardware counters,
+ * CPA_EVENT_TYPE1 is chosen.
+ */
+ reg = CPA_EVENT_TYPE0 + (idx / 4) * 4;
+ reg_idx = idx % 4;
+ shift = CPA_REG_OFFSET * reg_idx;
+
+ /* Write event code to CPA_EVENT_TYPEx Register */
+ val = readl(cpa_pmu->base + reg);
+ val &= ~(CPA_EVTYPE_MASK << shift);
+ val |= type << shift;
+ writel(val, cpa_pmu->base + reg);
+}
+
+static void hisi_cpa_pmu_start_counters(struct hisi_pmu *cpa_pmu)
+{
+ u32 val;
+
+ val = readl(cpa_pmu->base + CPA_PERF_CTRL);
+ val |= CPA_PERF_CTRL_EN;
+ writel(val, cpa_pmu->base + CPA_PERF_CTRL);
+}
+
+static void hisi_cpa_pmu_stop_counters(struct hisi_pmu *cpa_pmu)
+{
+ u32 val;
+
+ val = readl(cpa_pmu->base + CPA_PERF_CTRL);
+ val &= ~(CPA_PERF_CTRL_EN);
+ writel(val, cpa_pmu->base + CPA_PERF_CTRL);
+}
+
+static void hisi_cpa_pmu_disable_pm(struct hisi_pmu *cpa_pmu)
+{
+ u32 val;
+
+ val = readl(cpa_pmu->base + CPA_CFG_REG);
+ val |= CPA_PM_CTRL;
+ writel(val, cpa_pmu->base + CPA_CFG_REG);
+}
+
+static void hisi_cpa_pmu_enable_pm(struct hisi_pmu *cpa_pmu)
+{
+ u32 val;
+
+ val = readl(cpa_pmu->base + CPA_CFG_REG);
+ val &= ~(CPA_PM_CTRL);
+ writel(val, cpa_pmu->base + CPA_CFG_REG);
+}
+
+static void hisi_cpa_pmu_enable_counter(struct hisi_pmu *cpa_pmu, struct hw_perf_event *hwc)
+{
+ u32 val;
+
+ /* Enable counter index in CPA_EVENT_CTRL register */
+ val = readl(cpa_pmu->base + CPA_EVENT_CTRL);
+ val |= 1 << hwc->idx;
+ writel(val, cpa_pmu->base + CPA_EVENT_CTRL);
+}
+
+static void hisi_cpa_pmu_disable_counter(struct hisi_pmu *cpa_pmu, struct hw_perf_event *hwc)
+{
+ u32 val;
+
+ /* Clear counter index in CPA_EVENT_CTRL register */
+ val = readl(cpa_pmu->base + CPA_EVENT_CTRL);
+ val &= ~(1UL << hwc->idx);
+ writel(val, cpa_pmu->base + CPA_EVENT_CTRL);
+}
+
+static void hisi_cpa_pmu_enable_counter_int(struct hisi_pmu *cpa_pmu, struct hw_perf_event *hwc)
+{
+ u32 val;
+
+ /* Write 0 to enable interrupt */
+ val = readl(cpa_pmu->base + CPA_INT_MASK);
+ val &= ~(1UL << hwc->idx);
+ writel(val, cpa_pmu->base + CPA_INT_MASK);
+}
+
+static void hisi_cpa_pmu_disable_counter_int(struct hisi_pmu *cpa_pmu, struct hw_perf_event *hwc)
+{
+ u32 val;
+
+ /* Write 1 to mask interrupt */
+ val = readl(cpa_pmu->base + CPA_INT_MASK);
+ val |= 1 << hwc->idx;
+ writel(val, cpa_pmu->base + CPA_INT_MASK);
+}
+
+static u32 hisi_cpa_pmu_get_int_status(struct hisi_pmu *cpa_pmu)
+{
+ return readl(cpa_pmu->base + CPA_INT_STATUS);
+}
+
+static void hisi_cpa_pmu_clear_int_status(struct hisi_pmu *cpa_pmu, int idx)
+{
+ writel(1 << idx, cpa_pmu->base + CPA_INT_CLEAR);
+}
+
+static const struct acpi_device_id hisi_cpa_pmu_acpi_match[] = {
+ { "HISI0281", },
+ {}
+};
+MODULE_DEVICE_TABLE(acpi, hisi_cpa_pmu_acpi_match);
+
+static int hisi_cpa_pmu_init_data(struct platform_device *pdev,
+ struct hisi_pmu *cpa_pmu)
+{
+ if (device_property_read_u32(&pdev->dev, "hisilicon,scl-id",
+ &cpa_pmu->sicl_id)) {
+ dev_err(&pdev->dev, "Can not read sicl-id\n");
+ return -EINVAL;
+ }
+
+ if (device_property_read_u32(&pdev->dev, "hisilicon,idx-id",
+ &cpa_pmu->index_id)) {
+ dev_err(&pdev->dev, "Cannot read idx-id\n");
+ return -EINVAL;
+ }
+
+ cpa_pmu->ccl_id = -1;
+ cpa_pmu->sccl_id = -1;
+ cpa_pmu->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(cpa_pmu->base))
+ return PTR_ERR(cpa_pmu->base);
+
+ cpa_pmu->identifier = readl(cpa_pmu->base + CPA_VERSION);
+
+ return 0;
+}
+
+static struct attribute *hisi_cpa_pmu_format_attr[] = {
+ HISI_PMU_FORMAT_ATTR(event, "config:0-15"),
+ NULL
+};
+
+static const struct attribute_group hisi_cpa_pmu_format_group = {
+ .name = "format",
+ .attrs = hisi_cpa_pmu_format_attr,
+};
+
+static struct attribute *hisi_cpa_pmu_events_attr[] = {
+ HISI_PMU_EVENT_ATTR(cpa_cycles, 0x00),
+ HISI_PMU_EVENT_ATTR(cpa_p1_wr_dat, 0x61),
+ HISI_PMU_EVENT_ATTR(cpa_p1_rd_dat, 0x62),
+ HISI_PMU_EVENT_ATTR(cpa_p0_wr_dat, 0xE1),
+ HISI_PMU_EVENT_ATTR(cpa_p0_rd_dat, 0xE2),
+ NULL
+};
+
+static const struct attribute_group hisi_cpa_pmu_events_group = {
+ .name = "events",
+ .attrs = hisi_cpa_pmu_events_attr,
+};
+
+static DEVICE_ATTR(cpumask, 0444, hisi_cpumask_sysfs_show, NULL);
+
+static struct attribute *hisi_cpa_pmu_cpumask_attrs[] = {
+ &dev_attr_cpumask.attr,
+ NULL
+};
+
+static const struct attribute_group hisi_cpa_pmu_cpumask_attr_group = {
+ .attrs = hisi_cpa_pmu_cpumask_attrs,
+};
+
+static struct device_attribute hisi_cpa_pmu_identifier_attr =
+ __ATTR(identifier, 0444, hisi_uncore_pmu_identifier_attr_show, NULL);
+
+static struct attribute *hisi_cpa_pmu_identifier_attrs[] = {
+ &hisi_cpa_pmu_identifier_attr.attr,
+ NULL
+};
+
+static const struct attribute_group hisi_cpa_pmu_identifier_group = {
+ .attrs = hisi_cpa_pmu_identifier_attrs,
+};
+
+static const struct attribute_group *hisi_cpa_pmu_attr_groups[] = {
+ &hisi_cpa_pmu_format_group,
+ &hisi_cpa_pmu_events_group,
+ &hisi_cpa_pmu_cpumask_attr_group,
+ &hisi_cpa_pmu_identifier_group,
+ NULL
+};
+
+static const struct hisi_uncore_ops hisi_uncore_cpa_pmu_ops = {
+ .write_evtype = hisi_cpa_pmu_write_evtype,
+ .get_event_idx = hisi_uncore_pmu_get_event_idx,
+ .start_counters = hisi_cpa_pmu_start_counters,
+ .stop_counters = hisi_cpa_pmu_stop_counters,
+ .enable_counter = hisi_cpa_pmu_enable_counter,
+ .disable_counter = hisi_cpa_pmu_disable_counter,
+ .enable_counter_int = hisi_cpa_pmu_enable_counter_int,
+ .disable_counter_int = hisi_cpa_pmu_disable_counter_int,
+ .write_counter = hisi_cpa_pmu_write_counter,
+ .read_counter = hisi_cpa_pmu_read_counter,
+ .get_int_status = hisi_cpa_pmu_get_int_status,
+ .clear_int_status = hisi_cpa_pmu_clear_int_status,
+};
+
+static int hisi_cpa_pmu_dev_probe(struct platform_device *pdev,
+ struct hisi_pmu *cpa_pmu)
+{
+ int ret;
+
+ ret = hisi_cpa_pmu_init_data(pdev, cpa_pmu);
+ if (ret)
+ return ret;
+
+ ret = hisi_uncore_pmu_init_irq(cpa_pmu, pdev);
+ if (ret)
+ return ret;
+
+ cpa_pmu->counter_bits = CPA_COUNTER_BITS;
+ cpa_pmu->check_event = CPA_NR_EVENTS;
+ cpa_pmu->pmu_events.attr_groups = hisi_cpa_pmu_attr_groups;
+ cpa_pmu->ops = &hisi_uncore_cpa_pmu_ops;
+ cpa_pmu->num_counters = CPA_NR_COUNTERS;
+ cpa_pmu->dev = &pdev->dev;
+ cpa_pmu->on_cpu = -1;
+
+ return 0;
+}
+
+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.

+ 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

+
+ 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,