[PATCH v2 1/2] drivers/perf: hisi: Add driver for HiSilicon PCIe PMU

John Garry john.garry at huawei.com
Fri Apr 9 11:22:36 BST 2021


On 09/04/2021 10:05, Qi Liu wrote:
> PCIe PMU Root Complex Integrated End Point(RCiEP) device is supported
> to sample bandwidth, latency, buffer occupation etc.
> 
> Each PMU RCiEP device monitors multiple Root Ports, and each RCiEP is
> registered as a PMU in /sys/bus/event_source/devices, so users can
> select target PMU, and use filter to do further sets.
> 
> Filtering options contains:
> event        - select the event.
> subevent     - select the subevent.
> port         - select target Root Ports. Information of Root Ports
>                 are shown under sysfs.
> bdf          - select requester_id of target EP device.
> trig_len     - set trigger condition for starting event statistics.
> trigger_mode - set trigger mode. 0 means starting to statistic when
>                 bigger than trigger condition, and 1 means smaller.
> thr_len      - set threshold for statistics.
> thr_mode     - set threshold mode. 0 means count when bigger than
>                 threshold, and 1 means smaller.
> 
> Signed-off-by: Qi Liu <liuqi115 at huawei.com>
> ---
>   MAINTAINERS                                |    6 +
>   drivers/perf/Kconfig                       |    2 +
>   drivers/perf/Makefile                      |    1 +
>   drivers/perf/pci/Kconfig                   |   16 +
>   drivers/perf/pci/Makefile                  |    2 +
>   drivers/perf/pci/hisilicon/Makefile        |    5 +
>   drivers/perf/pci/hisilicon/hisi_pcie_pmu.c | 1011 ++++++++++++++++++++++++++++
>   include/linux/cpuhotplug.h                 |    1 +
>   8 files changed, 1044 insertions(+)
>   create mode 100644 drivers/perf/pci/Kconfig
>   create mode 100644 drivers/perf/pci/Makefile
>   create mode 100644 drivers/perf/pci/hisilicon/Makefile
>   create mode 100644 drivers/perf/pci/hisilicon/hisi_pcie_pmu.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 3353de0..46c7861 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8023,6 +8023,12 @@ W:	http://www.hisilicon.com
>   F:	Documentation/admin-guide/perf/hisi-pmu.rst
>   F:	drivers/perf/hisilicon
>   
> +HISILICON PCIE PMU DRIVER
> +M:	Qi Liu <liuqi115 at huawei.com>
> +S:	Maintained
> +F:	Documentation/admin-guide/perf/hisi-pcie-pmu.rst

nit: this does not exist yet...

> +F:	drivers/perf/pci/hisilicon/hisi_pcie_pmu.c
> +
>   HISILICON QM AND ZIP Controller DRIVER
>   M:	Zhou Wang <wangzhou1 at hisilicon.com>
>   L:	linux-crypto at vger.kernel.org
> diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
> index 3075cf1..99d4760 100644
> --- a/drivers/perf/Kconfig
> +++ b/drivers/perf/Kconfig
> @@ -139,4 +139,6 @@ config ARM_DMC620_PMU
>   
>   source "drivers/perf/hisilicon/Kconfig"
>   
> +source "drivers/perf/pci/Kconfig"
> +
>   endmenu
> diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile
> index 5260b11..1208c08 100644
> --- a/drivers/perf/Makefile
> +++ b/drivers/perf/Makefile
> @@ -14,3 +14,4 @@ obj-$(CONFIG_THUNDERX2_PMU) += thunderx2_pmu.o
>   obj-$(CONFIG_XGENE_PMU) += xgene_pmu.o
>   obj-$(CONFIG_ARM_SPE_PMU) += arm_spe_pmu.o
>   obj-$(CONFIG_ARM_DMC620_PMU) += arm_dmc620_pmu.o
> +obj-y += pci/
> diff --git a/drivers/perf/pci/Kconfig b/drivers/perf/pci/Kconfig
> new file mode 100644
> index 0000000..a119486
> --- /dev/null
> +++ b/drivers/perf/pci/Kconfig
> @@ -0,0 +1,16 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +#
> +# PCIe Performance Monitor Drivers
> +#
> +menu "PCIe Performance Monitor"
> +
> +config HISI_PCIE_PMU
> +	tristate "HiSilicon PCIE PERF PMU"
> +	depends on ARM64 && PCI && HISI_PMU

What from HISI_PMU is needed? I couldn't find anything here

> +	help
> +	  Provide support for HiSilicon PCIe performance monitoring unit (PMU)
> +	  RCiEP devices.
> +	  Adds the PCIe PMU into perf events system for monitoring latency,
> +	  bandwidth etc.
> +
> +endmenu
> diff --git a/drivers/perf/pci/Makefile b/drivers/perf/pci/Makefile
> new file mode 100644
> index 0000000..a56b1a9
> --- /dev/null
> +++ b/drivers/perf/pci/Makefile
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +obj-y += hisilicon/
> diff --git a/drivers/perf/pci/hisilicon/Makefile b/drivers/perf/pci/hisilicon/Makefile
> new file mode 100644
> index 0000000..6f99f52
> --- /dev/null
> +++ b/drivers/perf/pci/hisilicon/Makefile
> @@ -0,0 +1,5 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +ccflags-y :=  -I $(srctree)/drivers/perf/hisilicon
> +
> +obj-$(CONFIG_HISI_PCIE_PMU) += hisi_pcie_pmu.o
> diff --git a/drivers/perf/pci/hisilicon/hisi_pcie_pmu.c b/drivers/perf/pci/hisilicon/hisi_pcie_pmu.c
> new file mode 100644
> index 0000000..ac0e444
> --- /dev/null
> +++ b/drivers/perf/pci/hisilicon/hisi_pcie_pmu.c
> @@ -0,0 +1,1011 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * This driver adds support for PCIe PMU RCiEP device. Related
> + * perf events are bandwidth, bandwidth utilization, latency
> + * etc.
> + *
> + * Copyright (C) 2021 HiSilicon Limited
> + * Author: Qi Liu<liuqi115 at huawei.com>
> + */
> +#include <linux/bitfield.h>
> +#include <linux/bitmap.h>
> +#include <linux/bug.h>
> +#include <linux/cpuhotplug.h>
> +#include <linux/cpumask.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/kernel.h>
> +#include <linux/list.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +#include <linux/perf_event.h>
> +
> +#include "hisi_uncore_pmu.h"
> +
> +/* Define registers */
> +#define HISI_PCIE_GLOBAL_CTRL		0x00
> +#define HISI_PCIE_EVENT_CTRL		0x010
> +#define HISI_PCIE_CNT			0x090
> +#define HISI_PCIE_EXT_CNT		0x110
> +#define HISI_PCIE_INT_STAT		0x150
> +#define HISI_PCIE_INT_MASK		0x154
> +#define HISI_PCIE_REG_BDF		0xfe0
> +#define HISI_PCIE_REG_VERSION		0xfe4
> +#define HISI_PCIE_REG_INFO		0xfe8
> +#define HISI_PCIE_REG_FREQ		0xfec
> +
> +/* Define PCIE CTRL CMD */
> +#define HISI_PCIE_GLOBAL_EN		0x01
> +#define HISI_PCIE_GLOBAL_NONE		0
> +#define HISI_PCIE_EVENT_EN		BIT(20)
> +#define HISI_PCIE_RESET_CNT		BIT(22)
> +#define HISI_PCIE_DEFAULT_SET		BIT(34)
> +#define HISI_PCIE_THR_EN		BIT(26)
> +#define HISI_PCIE_TARGET_EN		BIT(32)
> +#define HISI_PCIE_TRIG_EN		BIT(52)
> +
> +/* Define offsets in event ctrl regesiter */
> +#define HISI_PCIE_EVENT_M		GENMASK_ULL(7, 0)
> +#define HISI_PCIE_SUBEVENT_M		GENMASK_ULL(15, 8)
> +#define HISI_PCIE_THR_MODE_M		GENMASK_ULL(27, 27)
> +#define HISI_PCIE_THR_M			GENMASK_ULL(31, 28)
> +#define HISI_PCIE_TARGET_M		GENMASK_ULL(52, 36)
> +#define HISI_PCIE_TRIG_MODE_M		GENMASK_ULL(53, 53)
> +#define HISI_PCIE_TRIG_M		GENMASK_ULL(59, 56)
> +
> +#define HISI_PCIE_MAX_COUNTERS		8
> +#define HISI_PCIE_REG_STEP		8
> +#define HISI_PCIE_EVENT_MAX		0xa2
> +#define HISI_PCIE_SUBEVENT_MAX		0x20
> +#define HISI_PCIE_THR_MAX_VAL		10
> +#define HISI_PCIE_TRIG_MAX_VAL		10
> +#define HISI_PCIE_COUNTER_BITS		64
> +#define HISI_PCIE_MAX_PERIOD		BIT_ULL(63)
> +
> +struct hisi_pcie_pmu {
> +	struct perf_event *hw_events[HISI_PCIE_MAX_COUNTERS];
> +	struct hlist_node node;
> +	struct pci_dev *pdev;
> +	struct pmu pmu;
> +	void __iomem *base;
> +	cpumask_t cpumask;
> +	int irq;
> +	u32 identifier;
> +	/* Minimum and maximum bdf of root ports monitored by PMU */
> +	u16 bdf_min;
> +	u16 bdf_max;
> +};
> +
> +#define to_pcie_pmu(p)  (container_of((p), struct hisi_pcie_pmu, pmu))
> +#define GET_PCI_DEVFN(bdf)  ((bdf) & 0xff)
> +
> +#define HISI_PCIE_PMU_FILTER_ATTR(_name, _config, _hi, _lo)       \
> +	static inline u64 hisi_pcie_get_##_name(struct perf_event *event)  \
> +	{                                                             \
> +		return FIELD_GET(GENMASK(_hi, _lo), event->attr._config); \
> +	}							\
> +
> +HISI_PCIE_PMU_FILTER_ATTR(event, config, 7, 0);
> +HISI_PCIE_PMU_FILTER_ATTR(subevent, config, 15, 8);
> +HISI_PCIE_PMU_FILTER_ATTR(thr_len, config1, 3, 0);
> +HISI_PCIE_PMU_FILTER_ATTR(thr_mode, config1, 4, 4);
> +HISI_PCIE_PMU_FILTER_ATTR(trig_len, config1, 8, 5);
> +HISI_PCIE_PMU_FILTER_ATTR(trig_mode, config1, 9, 9);
> +HISI_PCIE_PMU_FILTER_ATTR(port, config2, 15, 0);
> +HISI_PCIE_PMU_FILTER_ATTR(bdf, config2, 31, 16);
> +
> +#define HISI_PCIE_CHECK_EVENTS(name, list)             \

"check" in a function name is too vague, as it does not imply any 
side-effect from calling this function.

And I think "build" or similar would be good to be included in the macro 
name.

> +	static inline bool is_##name##_event(u32 idx)                  \

why inline?

> +	{                                                                   \
> +		if ((idx >= list[0] && idx <= list[1]) || idx == list[2])  \
> +			return true;                                        \
> +		return false;                                               \

isn't this just:
{
	return (idx >= list[0] && idx <= list[1]) || idx == list[2])
}

> +	}
> +
> +/*
> + * The first element of event list is minimum index of TL-layer events
> + * and the second element is maximum index. The third element is index
> + * of a DL-layer event.
> + */
> +static const u32 bw_events_list[] = {0x04, 0x08, 0x84};
> +static const u32 latency_events_list[] = {0x10, 0x15, 0x85};
> +static const u32 bus_util_events_list[] = {0x20, 0x24, 0x09};
> +static const u32 buf_util_events_list[] = {0x28, 0x2a, 0x33};
> +
> +HISI_PCIE_CHECK_EVENTS(bw, bw_events_list);
> +HISI_PCIE_CHECK_EVENTS(latency, latency_events_list);
> +HISI_PCIE_CHECK_EVENTS(bus_util, bus_util_events_list);
> +HISI_PCIE_CHECK_EVENTS(buf_util, buf_util_events_list);

Surely the macro can be fixed such that you need to have:
HISI_PCIE_CHECK_EVENTS(buf_util);


> +
> +static ssize_t hisi_pcie_cpumask_show(struct device *dev,
> +				      struct device_attribute *attr, char *buf)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(dev_get_drvdata(dev));
> +
> +	return cpumap_print_to_pagebuf(true, buf, &pcie_pmu->cpumask);
> +}
> +
> +static ssize_t hisi_pcie_identifier_show(struct device *dev,
> +					 struct device_attribute *attr,
> +					 char *buf)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(dev_get_drvdata(dev));
> +
> +	return sysfs_emit(buf, "0x%x\n", pcie_pmu->identifier);
> +}
> +
> +static ssize_t hisi_pcie_bus_show(struct device *dev,
> +				  struct device_attribute *attr, char *buf)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(dev_get_drvdata(dev));
> +
> +	return sysfs_emit(buf, "0x%02x\n", PCI_BUS_NUM(pcie_pmu->bdf_min));
> +}
> +
> +static void hisi_pcie_parse_data(struct hisi_pcie_pmu *pcie_pmu, u32 reg_off,

hisi_pcie_parse_data() name is way too vague. I mean, parse what data?

is there is some standard format register we use for various data types, 
then make that clear please

> +			       u16 *arg0, u16 *arg1)
> +{
> +	u32 val = readl(pcie_pmu->base + reg_off);
> +
> +	*arg0 = val & 0xffff;
> +	*arg1 = (val & 0xffff0000) >> 16;
> +}
> +
> +static u32 hisi_pcie_pmu_get_offset(u32 offset, u32 idx)
> +{
> +	return offset + HISI_PCIE_REG_STEP * idx;
> +}
> +
> +static u32 hisi_pcie_pmu_readl(struct hisi_pcie_pmu *pcie_pmu, u32 reg_offset,
> +			       u32 idx)
> +{
> +	u32 offset = hisi_pcie_pmu_get_offset(reg_offset, idx);
> +
> +	return readl(pcie_pmu->base + offset);
> +}
> +
> +static void hisi_pcie_pmu_writel(struct hisi_pcie_pmu *pcie_pmu, u32 reg_offset,
> +				 u32 idx, u32 val)
> +{
> +	u32 offset = hisi_pcie_pmu_get_offset(reg_offset, idx);
> +
> +	writel(val, pcie_pmu->base + offset);
> +}
> +
> +static u64 hisi_pcie_pmu_readq(struct hisi_pcie_pmu *pcie_pmu, u32 reg_offset,
> +			       u32 idx)
> +{
> +	u32 offset = hisi_pcie_pmu_get_offset(reg_offset, idx);
> +
> +	return readq(pcie_pmu->base + offset);
> +}
> +
> +static void hisi_pcie_pmu_writeq(struct hisi_pcie_pmu *pcie_pmu, u32 reg_offset,
> +				 u32 idx, u64 val)
> +{
> +	u32 offset = hisi_pcie_pmu_get_offset(reg_offset, idx);
> +
> +	writeq(val, pcie_pmu->base + offset);
> +}
> +
> +static u64 hisi_pcie_pmu_get_event(struct perf_event *event)

that function name is too vague

> +{
> +	return FIELD_PREP(HISI_PCIE_EVENT_M, hisi_pcie_get_event(event)) |
> +	       FIELD_PREP(HISI_PCIE_SUBEVENT_M, hisi_pcie_get_subevent(event));
> +}
> +
> +static u64 hisi_pcie_pmu_get_target(struct perf_event *event)

same here

> +{
> +	u64 port, val;
> +
> +	port = hisi_pcie_get_port(event);
> +	if (port) {
> +		val = FIELD_PREP(HISI_PCIE_TARGET_M, port);
> +	} else {
> +		val = FIELD_PREP(HISI_PCIE_TARGET_M, hisi_pcie_get_bdf(event));
> +		val |= HISI_PCIE_TARGET_EN;
> +	}
> +
> +	return val;
> +}
> +
> +static u64 hisi_pcie_pmu_get_trigger(struct perf_event *event)

and here

what you really seem to be doing is getting the formatted fields for the 
register


Having all these call-once functions seem to make life a bit more 
difficult...

> +{
> +	u64 trig_len, val;
> +
> +	trig_len = hisi_pcie_get_trig_len(event);
> +	if (!trig_len)
> +		return 0;
> +
> +	val = FIELD_PREP(HISI_PCIE_TRIG_M, trig_len);
> +	val |= FIELD_PREP(HISI_PCIE_TRIG_MODE_M,
> +			  hisi_pcie_get_trig_mode(event));
> +	val |= HISI_PCIE_TRIG_EN;
> +
> +	return val;
> +}
> +
> +static u64 hisi_pcie_pmu_get_thr(struct perf_event *event)
> +{
> +	u64 thr_len, val;
> +
> +	thr_len = hisi_pcie_get_thr_len(event);
> +	if (!thr_len)
> +		return 0;
> +
> +	val = FIELD_PREP(HISI_PCIE_THR_M, thr_len);
> +	val |= FIELD_PREP(HISI_PCIE_THR_MODE_M, hisi_pcie_get_thr_mode(event));
> +	val |= HISI_PCIE_THR_EN;
> +
> +	return val;
> +}
> +
> +static void hisi_pcie_pmu_config_filter(struct perf_event *event)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(event->pmu);
> +	struct hw_perf_event *hwc = &event->hw;
> +	u32 idx = hwc->idx;
> +	u64 val;
> +
> +	val = HISI_PCIE_DEFAULT_SET;
> +	val |= hisi_pcie_pmu_get_event(event);
> +	val |= hisi_pcie_pmu_get_target(event);
> +	val |= hisi_pcie_pmu_get_trigger(event);
> +	val |= hisi_pcie_pmu_get_thr(event);
> +	hisi_pcie_pmu_writeq(pcie_pmu, HISI_PCIE_EVENT_CTRL, idx, val);
> +}
> +
> +static void hisi_pcie_pmu_clear_filter(struct perf_event *event)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(event->pmu);
> +	struct hw_perf_event *hwc = &event->hw;
> +
> +	hisi_pcie_pmu_writeq(pcie_pmu, HISI_PCIE_EVENT_CTRL, hwc->idx,
> +			     HISI_PCIE_DEFAULT_SET);
> +}
> +
> +static bool hisi_pcie_pmu_valid_port(struct hisi_pcie_pmu *pcie_pmu, u16 bdf)
> +{
> +	return bdf <= pcie_pmu->bdf_max && bdf >= pcie_pmu->bdf_min;

nit: it is standard to have:

	if (x >= min && x <= max)

i.e. have min on the left

2nd nit: it is passed bdf, yet "port" is in the name


> +}
> +
> +static bool hisi_pcie_pmu_valid_requester_id(struct hisi_pcie_pmu *pcie_pmu,
> +					    u32 bdf)
> +{
> +	struct pci_dev *root_port, *pdev;
> +
> +	pdev = pci_get_domain_bus_and_slot(pci_domain_nr(pcie_pmu->pdev->bus),
> +					   PCI_BUS_NUM(bdf),
> +					   GET_PCI_DEVFN(bdf));
> +	if (!pdev)
> +		return false;
> +
> +	root_port = pcie_find_root_port(pdev);
> +	if (!root_port)
> +		return false;
> +
> +	pci_dev_put(pdev);
> +	return hisi_pcie_pmu_valid_port(pcie_pmu, pci_dev_id(root_port));
> +}
> +
> +static bool hisi_pcie_pmu_valid_filter(struct perf_event *event,
> +				       struct hisi_pcie_pmu *pcie_pmu)
> +{
> +	u32 subev_idx = hisi_pcie_get_subevent(event);
> +	u32 event_idx = hisi_pcie_get_event(event);
> +	u32 requester_id = hisi_pcie_get_bdf(event);
> +
> +	if (subev_idx > HISI_PCIE_SUBEVENT_MAX ||
> +	    event_idx > HISI_PCIE_EVENT_MAX) {
> +		pci_err(pcie_pmu->pdev,
> +			"Max event index and max subevent index is: %d, %d.\n",
> +			HISI_PCIE_EVENT_MAX, HISI_PCIE_SUBEVENT_MAX);

if this is just going to be fed back to userspace, I don't see why we 
need a kernel log

and the only caller also triggers an error message, which I doubt is needed

> +		return false;
> +	}
> +
> +	if (hisi_pcie_get_thr_len(event) > HISI_PCIE_THR_MAX_VAL)
> +		return false;
> +
> +	if (hisi_pcie_get_trig_len(event) > HISI_PCIE_TRIG_MAX_VAL)
> +		return false;
> +
> +	if (requester_id) {
> +		if (!hisi_pcie_pmu_valid_requester_id(pcie_pmu, requester_id)) {
> +			pci_err(pcie_pmu->pdev, "Invalid requester id.\n");

see previous comments

> +			return false;
> +		}
> +	}
> +
> +	return true;
> +}
> +
> +static bool hisi_pcie_pmu_validate_event_group(struct perf_event *event)
> +{
> +	struct perf_event *sibling, *leader = event->group_leader;
> +	int counters = 1;
> +
> +	if (!is_software_event(leader)) {
> +		if (leader->pmu != event->pmu)
> +			return false;
> +
> +		if (leader != event)
> +			counters++;
> +	}
> +
> +	for_each_sibling_event(sibling, event->group_leader) {
> +		if (is_software_event(sibling))
> +			continue;
> +
> +		if (sibling->pmu != event->pmu)
> +			return false;
> +
> +		counters++;
> +	}
> +
> +	return counters <= HISI_PCIE_MAX_COUNTERS;
> +}
> +
> +static int hisi_pcie_pmu_event_init(struct perf_event *event)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(event->pmu);
> +
> +	event->cpu = cpumask_first(&pcie_pmu->cpumask);
> +
> +	if (event->attr.type != event->pmu->type)
> +		return -ENOENT;
> +
> +	/* Sampling is not supported. */
> +	if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
> +		return -EOPNOTSUPP;
> +
> +	/* Per-task mode is not supported. */
> +	if (event->cpu < 0)

cpumask_first() gives an unsigned int - this can never happen

> +		return -EINVAL;
> +
> +	if (!hisi_pcie_pmu_valid_filter(event, pcie_pmu)) {
> +		pci_err(pcie_pmu->pdev, "Invalid filter!\n");
> +		return -EINVAL;
> +	}
> +
> +	if (!hisi_pcie_pmu_validate_event_group(event))
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static u64 hisi_pcie_pmu_process_data(struct perf_event *event, u64 val,

function name too vague, as are the argument names

> +				      u64 val_ext)
> +{
> +#define CONVERT_DW_TO_BYTE(x)	(sizeof(u32) * (x))
> +	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(event->pmu);
> +	u64 us_per_cycle = readl(pcie_pmu->base + HISI_PCIE_REG_FREQ);
> +	u32 idx = hisi_pcie_get_event(event);
> +
> +	if (!val_ext)
> +		return 0;
> +
> +	/*
> +	 * The bandwidth, latency, bus utilization and buffer occupancy
> +	 * are obtained by the (COMMON_COUNTER and EXT_COUNTER). And other
> +	 * features are obtained by COMMON_COUNTER.
> +	 */
> +	if (is_bw_event(idx)) {
> +		if (!val_ext / 1000)
> +			return 0;
> +
> +		/* Process data to set unit of bandwidth as "Byte/ms". */
> +		return (CONVERT_DW_TO_BYTE(val)) / (val_ext / 1000);
> +	}
> +
> +	if (is_latency_event(idx))
> +		/* Process data to set unit of latency as "us". */

it's not a good programming practice to put comments after an if 
statement like this

> +		return (val * us_per_cycle) / val_ext;
> +
> +	if (is_bus_util_event(idx))
> +		return (val * us_per_cycle) / val_ext;
> +
> +	if (is_buf_util_event(idx))
> +		return val / (val_ext * us_per_cycle);
> +
> +	return val;
> +}
> +
> +static void hisi_pcie_pmu_read_counter(struct perf_event *event, u64 *cnt,
> +				       u64 *cnt_ext)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(event->pmu);
> +	u32 idx = event->hw.idx;
> +
> +	*cnt = hisi_pcie_pmu_readq(pcie_pmu, HISI_PCIE_CNT, idx);
> +	*cnt_ext = hisi_pcie_pmu_readq(pcie_pmu, HISI_PCIE_EXT_CNT, idx);
> +}
> +
> +static void hisi_pcie_pmu_write_counter(struct perf_event *event, u64 val,
> +					u64 val_ext)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(event->pmu);
> +	u32 idx = event->hw.idx;
> +
> +	hisi_pcie_pmu_writeq(pcie_pmu, HISI_PCIE_CNT, idx, val);
> +	hisi_pcie_pmu_writeq(pcie_pmu, HISI_PCIE_EXT_CNT, idx, val_ext);
> +}
> +
> +static int hisi_pcie_pmu_get_event_idx(struct hisi_pcie_pmu *pcie_pmu)
> +{
> +	int idx;
> +
> +	for (idx = 0; idx < HISI_PCIE_MAX_COUNTERS; idx++) {
> +		if (!pcie_pmu->hw_events[idx])
> +			return idx;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static void hisi_pcie_pmu_read(struct perf_event *event)
> +{
> +	struct hw_perf_event *hwc = &event->hw;
> +	struct hw_perf_event_extra *hwc_ext = &hwc->extra_reg;
> +	u64 new_cnt_ext, prev_cnt_ext;
> +	u64 new_cnt, prev_cnt, delta;
> +
> +	hwc_ext = &hwc->extra_reg;
> +	do {
> +		prev_cnt = local64_read(&hwc->prev_count);
> +		prev_cnt_ext = hwc_ext->config;
> +		hisi_pcie_pmu_read_counter(event, &new_cnt, &new_cnt_ext);
> +	} while (local64_cmpxchg(&hwc->prev_count, prev_cnt,
> +				 new_cnt) != prev_cnt);
> +
> +	hwc_ext->config = new_cnt_ext;
> +
> +	delta = hisi_pcie_pmu_process_data(event, new_cnt - prev_cnt,
> +					   new_cnt_ext - prev_cnt_ext);
> +	local64_add(delta, &event->count);
> +}
> +
> +static void hisi_pcie_pmu_set_period(struct perf_event *event)
> +{
> +	struct hw_perf_event *hwc = &event->hw;
> +	struct hw_perf_event_extra *hwc_ext;
> +	u64 val = BIT_ULL(HISI_PCIE_COUNTER_BITS - 1);
> +
> +	hwc_ext = &hwc->extra_reg;
> +	local64_set(&hwc->prev_count, val);
> +	hwc_ext->config = 0;
> +	hisi_pcie_pmu_write_counter(event, val, 0);
> +}
> +
> +static void hisi_pcie_pmu_enable_counter(struct hisi_pcie_pmu *pcie_pmu,
> +					 struct hw_perf_event *hwc)
> +{
> +	u32 idx = hwc->idx;
> +	u64 val;
> +
> +	val = hisi_pcie_pmu_readq(pcie_pmu, HISI_PCIE_EVENT_CTRL, idx);
> +	val |= HISI_PCIE_EVENT_EN;
> +	hisi_pcie_pmu_writeq(pcie_pmu, HISI_PCIE_EVENT_CTRL, idx, val);
> +}
> +
> +static void hisi_pcie_pmu_disable_counter(struct hisi_pcie_pmu *pcie_pmu,
> +					  struct hw_perf_event *hwc)
> +{
> +	u32 idx = hwc->idx;
> +	u64 val;
> +
> +	val = hisi_pcie_pmu_readq(pcie_pmu, HISI_PCIE_EVENT_CTRL, idx);
> +	val &= ~HISI_PCIE_EVENT_EN;
> +	hisi_pcie_pmu_writeq(pcie_pmu, HISI_PCIE_EVENT_CTRL, idx, val);
> +}
> +
> +static void hisi_pcie_pmu_enable_int(struct hisi_pcie_pmu *pcie_pmu,
> +				     struct hw_perf_event *hwc)
> +{
> +	u32 idx = hwc->idx;
> +
> +	hisi_pcie_pmu_writel(pcie_pmu, HISI_PCIE_INT_MASK, idx, 0);
> +}
> +
> +static void hisi_pcie_pmu_disable_int(struct hisi_pcie_pmu *pcie_pmu,
> +				      struct hw_perf_event *hwc)
> +{
> +	u32 idx = hwc->idx;
> +
> +	hisi_pcie_pmu_writel(pcie_pmu, HISI_PCIE_INT_MASK, idx, 1);
> +}
> +
> +static void hisi_pcie_pmu_reset_counter(struct hisi_pcie_pmu *pcie_pmu,
> +					struct hw_perf_event *hwc)
> +{
> +	u32 idx = hwc->idx;
> +
> +	hisi_pcie_pmu_writeq(pcie_pmu, HISI_PCIE_EVENT_CTRL, idx,
> +			     HISI_PCIE_RESET_CNT);
> +	hisi_pcie_pmu_writeq(pcie_pmu, HISI_PCIE_EVENT_CTRL, idx,
> +			     HISI_PCIE_DEFAULT_SET);
> +}
> +
> +static void hisi_pcie_pmu_start(struct perf_event *event, int flags)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(event->pmu);
> +	struct hw_perf_event *hwc = &event->hw;
> +	struct hw_perf_event_extra *hwc_ext;
> +	u64 prev_cnt, prev_cnt_ext;
> +
> +	hwc_ext = &hwc->extra_reg;
> +	if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
> +		return;
> +
> +	WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
> +	hwc->state = 0;
> +
> +	hisi_pcie_pmu_config_filter(event);
> +	hisi_pcie_pmu_enable_counter(pcie_pmu, hwc);
> +	hisi_pcie_pmu_enable_int(pcie_pmu, hwc);
> +	hisi_pcie_pmu_set_period(event);
> +
> +	if (flags & PERF_EF_RELOAD) {
> +		prev_cnt = local64_read(&hwc->prev_count);
> +		prev_cnt_ext = hwc_ext->config;
> +		hisi_pcie_pmu_write_counter(event, prev_cnt, prev_cnt_ext);
> +	}
> +
> +	perf_event_update_userpage(event);
> +}
> +
> +static void hisi_pcie_pmu_stop(struct perf_event *event, int flags)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(event->pmu);
> +	struct hw_perf_event *hwc = &event->hw;
> +
> +	hisi_pcie_pmu_read(event);

why do this - it just reads a register? and so why not check the return 
value?

> +	hisi_pcie_pmu_disable_int(pcie_pmu, hwc);
> +	hisi_pcie_pmu_disable_counter(pcie_pmu, hwc);
> +	hisi_pcie_pmu_clear_filter(event);
> +	WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
> +	hwc->state |= PERF_HES_STOPPED;
> +
> +	if (hwc->state & PERF_HES_UPTODATE)
> +		return;
> +
> +	hwc->state |= PERF_HES_UPTODATE;
> +}
> +
> +static int hisi_pcie_pmu_add(struct perf_event *event, int flags)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(event->pmu);
> +	struct hw_perf_event *hwc = &event->hw;
> +	int idx;
> +
> +	hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
> +	idx = hisi_pcie_pmu_get_event_idx(pcie_pmu);
> +	if (idx < 0)
> +		return idx;
> +
> +	hwc->idx = idx;
> +	pcie_pmu->hw_events[idx] = event;
> +
> +	/* Reset PMC to avoid interference caused by previous statistic. */

what is PMC?

> +	hisi_pcie_pmu_reset_counter(pcie_pmu, hwc);
> +
> +	if (flags & PERF_EF_START)
> +		hisi_pcie_pmu_start(event, PERF_EF_RELOAD);
> +
> +	return 0;
> +}
> +
> +static void hisi_pcie_pmu_del(struct perf_event *event, int flags)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(event->pmu);
> +	struct hw_perf_event *hwc = &event->hw;
> +
> +	hisi_pcie_pmu_stop(event, PERF_EF_UPDATE);
> +	pcie_pmu->hw_events[hwc->idx] = NULL;
> +	perf_event_update_userpage(event);
> +}
> +
> +static void hisi_pcie_pmu_enable(struct pmu *pmu)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(pmu);
> +	int num;
> +
> +	for (num = 0; num < HISI_PCIE_MAX_COUNTERS; num++) {
> +		if (pcie_pmu->hw_events[num])
> +			break;
> +	}
> +
> +	if (num == HISI_PCIE_MAX_COUNTERS)
> +		return;
> +
> +	writel(HISI_PCIE_GLOBAL_EN, pcie_pmu->base + HISI_PCIE_GLOBAL_CTRL);
> +}
> +
> +static void hisi_pcie_pmu_disable(struct pmu *pmu)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(pmu);
> +
> +	writel(HISI_PCIE_GLOBAL_NONE, pcie_pmu->base + HISI_PCIE_GLOBAL_CTRL);
> +}
> +
> +static irqreturn_t hisi_pcie_pmu_irq(int irq, void *data)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = data;
> +	irqreturn_t ret = IRQ_NONE;
> +	struct perf_event *event;
> +	u32 overflown;
> +	int idx;
> +
> +	for (idx = 0; idx < HISI_PCIE_MAX_COUNTERS; idx++) {
> +		overflown = hisi_pcie_pmu_readl(pcie_pmu, HISI_PCIE_INT_STAT,
> +						idx);
> +		if (!overflown)
> +			continue;
> +
> +		/* Clear status of interrupt. */
> +		hisi_pcie_pmu_writel(pcie_pmu, HISI_PCIE_INT_STAT, idx, 1);
> +		event = pcie_pmu->hw_events[idx];
> +		if (!event)
> +			continue;
> +
> +		hisi_pcie_pmu_read(event);
> +		hisi_pcie_pmu_set_period(event);
> +		ret = IRQ_HANDLED;
> +	}
> +
> +	return ret;
> +}
> +
> +static int hisi_pcie_pmu_irq_register(struct pci_dev *pdev,
> +				      struct hisi_pcie_pmu *pcie_pmu)
> +{
> +	int irq, ret;
> +
> +	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
> +	if (ret < 0) {
> +		pci_err(pdev, "Failed to enable MSI vectors, ret = %d!\n", ret);
> +		return ret;
> +	}
> +
> +	irq = pci_irq_vector(pdev, 0);
> +	ret = request_irq(irq, hisi_pcie_pmu_irq, IRQF_SHARED, "hisi_pcie_pmu",


is this interrupt line really shared?

> +			  pcie_pmu);
> +	if (ret) {
> +		pci_err(pdev, "Failed to register irq, ret = %d!\n", ret);
> +		pci_free_irq_vectors(pdev);
> +		return ret;
> +	}
> +
> +	pcie_pmu->irq = irq;
> +
> +	return 0;
> +}
> +
> +static void hisi_pcie_pmu_irq_unregister(struct pci_dev *pdev,
> +					 struct hisi_pcie_pmu *pcie_pmu)
> +{
> +	free_irq(pcie_pmu->irq, pcie_pmu);
> +	pci_free_irq_vectors(pdev);
> +}
> +
> +static int hisi_pcie_pmu_online_cpu(unsigned int cpu, struct hlist_node *node)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = hlist_entry_safe(node,
> +					 struct hisi_pcie_pmu, node);
> +
> +	if (cpumask_empty(&pcie_pmu->cpumask)) {
> +		cpumask_set_cpu(cpu, &pcie_pmu->cpumask);
> +		WARN_ON(irq_set_affinity_hint(pcie_pmu->irq, cpumask_of(cpu)));
> +	}
> +
> +	return 0;
> +}
> +
> +static int hisi_pcie_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu = hlist_entry_safe(node,
> +					 struct hisi_pcie_pmu, node);
> +	unsigned int target;
> +
> +	if (!cpumask_test_and_clear_cpu(cpu, &pcie_pmu->cpumask))

I do wonder why we even need maintain pcie_pmu->cpumask

Can't we just use cpu_online_mask as appropiate instead?

> +		return 0;
> +
> +	/* Choose a new CPU from all online cpus. */
> +	target = cpumask_any_but(cpu_online_mask, cpu);
> +	if (target >= nr_cpu_ids)
> +		return 0;
> +
> +	perf_pmu_migrate_context(&pcie_pmu->pmu, cpu, target);
> +	WARN_ON(irq_set_affinity_hint(pcie_pmu->irq, cpumask_of(target)));
> +
> +	return 0;
> +}
> +
> +/*
> + * Events with the "dl" suffix in their names count performance in DL layer,
> + * otherswise, events count performance in TL layer.
> + */
> +static struct attribute *hisi_pcie_pmu_events_attr[] = {
> +	HISI_PMU_EVENT_ATTR(bw_rx_mwr, 0x0104),
> +	HISI_PMU_EVENT_ATTR(bw_rx_mrd, 0x1005),
> +	HISI_PMU_EVENT_ATTR(bw_tx_mwr, 0x0105),
> +	HISI_PMU_EVENT_ATTR(bw_tx_mrd, 0x2004),
> +	HISI_PMU_EVENT_ATTR(lat_rx_mwr, 0x0010),
> +	HISI_PMU_EVENT_ATTR(lat_rx_mrd, 0x0210),
> +	HISI_PMU_EVENT_ATTR(lat_tx_mrd, 0x0011),
> +	HISI_PMU_EVENT_ATTR(lat_tx_cfg, 0x0111),
> +	HISI_PMU_EVENT_ATTR(bw_rx_dl, 0x0184),
> +	HISI_PMU_EVENT_ATTR(bw_tx_dl, 0x0384),

it would be nice to see JSONs for these as well with full event descriptions

> +	NULL
> +};
> +
> +static struct attribute_group hisi_pcie_pmu_events_group = {
> +	.name = "events",
> +	.attrs = hisi_pcie_pmu_events_attr,
> +};
> +
> +static struct attribute *hisi_pcie_pmu_format_attr[] = {
> +	HISI_PMU_FORMAT_ATTR(event, "config:0-7"),
> +	HISI_PMU_FORMAT_ATTR(subevent, "config:8-15"),
> +	HISI_PMU_FORMAT_ATTR(thr_len, "config1:0-3"),
> +	HISI_PMU_FORMAT_ATTR(thr_mode, "config1:4"),
> +	HISI_PMU_FORMAT_ATTR(trig_len, "config1:5-8"),
> +	HISI_PMU_FORMAT_ATTR(trig_mode, "config1:9"),
> +	HISI_PMU_FORMAT_ATTR(port, "config2:0-15"),
> +	HISI_PMU_FORMAT_ATTR(bdf, "config2:16-31"),
> +	NULL
> +};
> +
> +static struct attribute_group hisi_pcie_pmu_format_group = {
> +	.name = "format",
> +	.attrs = hisi_pcie_pmu_format_attr,
> +};
> +
> +static struct device_attribute hisi_pcie_pmu_bus_attr =
> +	__ATTR(bus, 0444, hisi_pcie_bus_show, NULL);
> +
> +static struct attribute *hisi_pcie_pmu_bus_attrs[] = {
> +	&hisi_pcie_pmu_bus_attr.attr,
> +	NULL
> +};
> +
> +static struct attribute_group hisi_pcie_pmu_bus_attr_group = {
> +	.attrs = hisi_pcie_pmu_bus_attrs,
> +};
> +
> +static struct device_attribute hisi_pcie_pmu_cpumask_attr =
> +	__ATTR(cpumask, 0444, hisi_pcie_cpumask_show, NULL);
> +
> +static struct attribute *hisi_pcie_pmu_cpumask_attrs[] = {
> +	&hisi_pcie_pmu_cpumask_attr.attr,
> +	NULL
> +};
> +
> +static struct attribute_group hisi_pcie_pmu_cpumask_attr_group = {
> +	.attrs = hisi_pcie_pmu_cpumask_attrs,
> +};
> +
> +static struct device_attribute hisi_pcie_pmu_identifier_attr =
> +	__ATTR(identifier, 0444, hisi_pcie_identifier_show, NULL);
> +
> +static struct attribute *hisi_pcie_pmu_identifier_attrs[] = {
> +	&hisi_pcie_pmu_identifier_attr.attr,
> +	NULL
> +};
> +
> +static struct attribute_group hisi_pcie_pmu_identifier_attr_group = {
> +	.attrs = hisi_pcie_pmu_identifier_attrs,
> +};
> +
> +static const struct attribute_group *hisi_pcie_pmu_attr_groups[] = {
> +	&hisi_pcie_pmu_events_group,
> +	&hisi_pcie_pmu_format_group,
> +	&hisi_pcie_pmu_bus_attr_group,
> +	&hisi_pcie_pmu_cpumask_attr_group,
> +	&hisi_pcie_pmu_identifier_attr_group,
> +	NULL
> +};
> +
> +static int hisi_pcie_alloc_pmu(struct pci_dev *pdev,
> +			     struct hisi_pcie_pmu *pcie_pmu)
> +{
> +	u16 sicl_id, device_id;
> +	char *name;
> +
> +	pcie_pmu->base = pci_ioremap_bar(pdev, 2);
> +	if (!pcie_pmu->base) {
> +		pci_err(pdev, "Ioremap failed for pcie_pmu resource.\n");
> +		return -ENOMEM;
> +	}
> +
> +	hisi_pcie_parse_data(pcie_pmu, HISI_PCIE_REG_BDF, &pcie_pmu->bdf_min,
> +			   &pcie_pmu->bdf_max);
> +	hisi_pcie_parse_data(pcie_pmu, HISI_PCIE_REG_INFO, &device_id,
> +			     &sicl_id);
> +	name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
> +			      "hisi_pcie%u_%u", sicl_id, device_id);
> +	if (!name) {
> +		pci_err(pdev, "Failed to allocate name for PMU.\n");

no need for that log

> +		return -ENOMEM;
> +	}
> +
> +	pcie_pmu->pdev = pdev;
> +	pcie_pmu->identifier = readl(pcie_pmu->base + HISI_PCIE_REG_VERSION);
> +	pcie_pmu->pmu = (struct pmu) {
> +		.name		= name,
> +		.module		= THIS_MODULE,
> +		.event_init	= hisi_pcie_pmu_event_init,
> +		.pmu_enable	= hisi_pcie_pmu_enable,
> +		.pmu_disable	= hisi_pcie_pmu_disable,
> +		.add		= hisi_pcie_pmu_add,
> +		.del		= hisi_pcie_pmu_del,
> +		.start		= hisi_pcie_pmu_start,
> +		.stop		= hisi_pcie_pmu_stop,
> +		.read		= hisi_pcie_pmu_read,
> +		.task_ctx_nr	= perf_invalid_context,
> +		.attr_groups	= hisi_pcie_pmu_attr_groups,
> +		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
> +	};
> +
> +	return 0;
> +}
> +
> +static int hisi_pcie_init_pmu(struct pci_dev *pdev,
> +			      struct hisi_pcie_pmu *pcie_pmu)
> +{
> +	int ret;
> +
> +	ret = hisi_pcie_alloc_pmu(pdev, pcie_pmu);
> +	if (ret)
> +		return ret;
> +
> +	ret = hisi_pcie_pmu_irq_register(pdev, pcie_pmu);
> +	if (ret)
> +		goto err_set_pmu_fail;
> +
> +	ret = cpuhp_state_add_instance(CPUHP_AP_PERF_ARM_HISI_PCIE_PMU_ONLINE,
> +				       &pcie_pmu->node);
> +	if (ret) {
> +		pci_err(pdev, "Failed to register hotplug, ret = %d.\n", ret);
> +		goto err_irq_unregister;
> +	}
> +
> +	ret = perf_pmu_register(&pcie_pmu->pmu, pcie_pmu->pmu.name, -1);
> +	if (ret) {
> +		pci_err(pdev, "Failed to register PCIe PMU, ret = %d.\n", ret);
> +		goto err_hotplug_unregister;
> +	}
> +
> +	return ret;
> +
> +err_hotplug_unregister:
> +	cpuhp_state_remove_instance(CPUHP_AP_PERF_ARM_HISI_PCIE_PMU_ONLINE,
> +				    &pcie_pmu->node);
> +	irq_set_affinity_hint(pcie_pmu->irq, NULL);
> +
> +err_irq_unregister:
> +	hisi_pcie_pmu_irq_unregister(pdev, pcie_pmu);
> +
> +err_set_pmu_fail:
> +	iounmap(pcie_pmu->base);
> +
> +	return ret;
> +}
> +
> +static void hisi_pcie_uninit_pmu(struct pci_dev *pdev,
> +				 struct hisi_pcie_pmu *pcie_pmu)
> +{
> +	perf_pmu_unregister(&pcie_pmu->pmu);
> +	cpuhp_state_remove_instance(CPUHP_AP_PERF_ARM_HISI_PCIE_PMU_ONLINE,
> +				    &pcie_pmu->node);
> +	irq_set_affinity_hint(pcie_pmu->irq, NULL);
> +	hisi_pcie_pmu_irq_unregister(pdev, pcie_pmu);
> +	iounmap(pcie_pmu->base);
> +}
> +
> +static int hisi_pcie_init_dev(struct pci_dev *pdev)
> +{
> +	int ret;
> +
> +	ret = pci_enable_device(pdev);
> +	if (ret) {
> +		pci_err(pdev, "Failed to enable pci device, ret = %d.\n", ret);
> +		return ret;
> +	}
> +
> +	ret = pci_request_mem_regions(pdev, "hisi_pcie_pmu");
> +	if (ret < 0) {
> +		pci_err(pdev, "Failed to request pci mem regions, ret = %d.\n",
> +			ret);
> +		pci_disable_device(pdev);
> +		return ret;
> +	}
> +
> +	pci_set_master(pdev);
> +
> +	return 0;
> +}
> +
> +static void hisi_pcie_uninit_dev(struct pci_dev *pdev)
> +{
> +	pci_clear_master(pdev);
> +	pci_release_mem_regions(pdev);
> +	pci_disable_device(pdev);
> +}
> +
> +static int hisi_pcie_pmu_probe(struct pci_dev *pdev,
> +			       const struct pci_device_id *id)
> +{
> +	struct hisi_pcie_pmu *pcie_pmu;
> +	int ret;
> +
> +	pcie_pmu = devm_kzalloc(&pdev->dev, sizeof(*pcie_pmu), GFP_KERNEL);
> +	if (!pcie_pmu)
> +		return -ENOMEM;
> +
> +	ret = hisi_pcie_init_dev(pdev);
> +	if (ret)
> +		return ret;
> +
> +	ret = hisi_pcie_init_pmu(pdev, pcie_pmu);
> +	if (ret)
> +		hisi_pcie_uninit_dev(pdev);
> +
> +	pci_set_drvdata(pdev, pcie_pmu);
> +
> +	return ret;
> +}
> +
> +static void hisi_pcie_pmu_remove(struct pci_dev *pdev)
> +{
> +	hisi_pcie_uninit_pmu(pdev, pci_get_drvdata(pdev));

passing both pdev and pci_get_drvdata(pdev) should not be needed

> +	hisi_pcie_uninit_dev(pdev);
> +	pci_set_drvdata(pdev, NULL); > +}
> +
> +static const struct pci_device_id hisi_pcie_pmu_ids[] = {
> +	{ PCI_DEVICE(PCI_VENDOR_ID_HUAWEI, 0xa12d) },
> +	{ 0, }
> +};
> +MODULE_DEVICE_TABLE(pci, hisi_pcie_pmu_ids);
> +
> +static struct pci_driver hisi_pcie_pmu_driver = {
> +	.name = "hisi_pcie_pmu",
> +	.id_table = hisi_pcie_pmu_ids,
> +	.probe = hisi_pcie_pmu_probe,
> +	.remove = hisi_pcie_pmu_remove,
> +};
> +
> +static int __init hisi_pcie_module_init(void)
> +{
> +	int ret;
> +
> +	ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_HISI_PCIE_PMU_ONLINE,
> +				      "AP_PERF_ARM_HISI_PCIE_PMU_ONLINE",
> +				      hisi_pcie_pmu_online_cpu,
> +				      hisi_pcie_pmu_offline_cpu);
> +	if (ret) {
> +		pr_err("Failed to setup PCIE PMU hotplug, ret = %d.\n", ret);
> +		return ret;
> +	}
> +
> +	ret = pci_register_driver(&hisi_pcie_pmu_driver);
> +	if (ret)
> +		cpuhp_remove_multi_state(
> +				CPUHP_AP_PERF_ARM_HISI_PCIE_PMU_ONLINE);
> +
> +	return ret;
> +}
> +module_init(hisi_pcie_module_init);
> +
> +static void __exit hisi_pcie_module_exit(void)
> +{
> +	pci_unregister_driver(&hisi_pcie_pmu_driver);
> +	cpuhp_remove_multi_state(CPUHP_AP_PERF_ARM_HISI_PCIE_PMU_ONLINE);
> +}
> +module_exit(hisi_pcie_module_exit);
> +
> +MODULE_DESCRIPTION("HiSilicon PCIe PMU driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Qi Liu <liuqi115 at huawei.com>");
> diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
> index 113f51f..c17861a 100644
> --- a/include/linux/cpuhotplug.h
> +++ b/include/linux/cpuhotplug.h
> @@ -174,6 +174,7 @@ enum cpuhp_state {
>   	CPUHP_AP_PERF_ARM_HISI_DDRC_ONLINE,
>   	CPUHP_AP_PERF_ARM_HISI_HHA_ONLINE,
>   	CPUHP_AP_PERF_ARM_HISI_L3_ONLINE,
> +	CPUHP_AP_PERF_ARM_HISI_PCIE_PMU_ONLINE,
>   	CPUHP_AP_PERF_ARM_L2X0_ONLINE,
>   	CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
>   	CPUHP_AP_PERF_ARM_QCOM_L3_ONLINE,
> 




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