2022-04-07 20:01:44

by John Garry

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

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 <[email protected]>

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

Reviewed-by: John Garry <[email protected]>

> ---
> 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 <[email protected]>
> + *
> + * 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 <[email protected]>");
> 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,