Subject: Re: [RFC PATCH v3 2/2] drivers/perf: hisi: add driver for HNS3 PMU

From: Jonathan Cameron <[email-masked]>
Date: Mon, 10 May 2021 17:33:18 +0100

On Sat, 8 May 2021 17:44:56 +0800
Guangbin Huang <[email-masked]> wrote:

> HNS3 PMU End Point device supports to collect performance statistics

support collection of performance...

> of bandwidth, latency, packet rate, interrupt rate in HiSilicon SoC
> NIC.
> 
> NIC of each IO DIE has one PMU device for it. Driver registers each

There is one HNS3 PMU device per IO die. (perhaps?)
 
> PMU device to perf, and exports information of supported events,
> filter mode of each event, identifier and so on via sysfs.
> 
> Each PMU device has its own control, counter and interrupt registers,
> and supports up to 8 events by hardware.

supports 8 hardware event counters.

> 
> Filter options contains:
> event        - select event
> subevent     - select subevent
> port         - select physical port of nic

NIC

> tc           - select tc(must be used with port)

define TC 

> func         - select PF/VF
> queue        - select queue of PF/VF(must be used with func)
> intr         - select interrupt number(must be used with func)
> global       - select all functions of IO DIE
> 
> Signed-off-by: Guangbin Huang <[email-masked]>

Hi.  A few general comments inline.

> ---
>  MAINTAINERS                           |    6 +
>  drivers/perf/pci/Kconfig              |    8 +
>  drivers/perf/pci/hisilicon/Makefile   |    1 +
>  drivers/perf/pci/hisilicon/hns3_pmu.c | 1586 +++++++++++++++++++++++++++++++++
>  include/linux/cpuhotplug.h            |    1 +
>  5 files changed, 1602 insertions(+)
>  create mode 100644 drivers/perf/pci/hisilicon/hns3_pmu.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 2beb4cb..da7354a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8194,6 +8194,12 @@ S:	Maintained
>  F:	Documentation/admin-guide/perf/hisi-pcie-pmu.rst
>  F:	drivers/perf/pci/hisilicon/hisi_pcie_pmu.c
>  
> +HISILICON HNS3 PMU DRIVER
> +M:	Guangbin Huang <[email-masked]>
> +S:	Supported
> +F:	Documentation/admin-guide/perf/hns3-pmu.rst
> +F:	drivers/perf/pci/hisilicon/hns3_pmu.c
> +
>  HISILICON QM AND ZIP Controller DRIVER
>  M:	Zhou Wang <[email-masked]>
>  L:	[email-masked]
> diff --git a/drivers/perf/pci/Kconfig b/drivers/perf/pci/Kconfig
> index 9f30291..4f85afd 100644
> --- a/drivers/perf/pci/Kconfig
> +++ b/drivers/perf/pci/Kconfig
> @@ -13,4 +13,12 @@ config HISI_PCIE_PMU
>  	  Adds the PCIe PMU into perf events system for monitoring latency,
>  	  bandwidth etc.
>  
> +config HNS3_PMU
> +	tristate "HNS3 PERF PMU"
> +	depends on ARM64 && PCI
> +	help
> +	  Provide support for HNS3 performance monitoring unit (PMU) IEP
> +	  devices.
> +	  Adds the HNS3 PMU into perf events system for monitoring latency,
> +	  bandwidth etc.
>  endmenu
> diff --git a/drivers/perf/pci/hisilicon/Makefile b/drivers/perf/pci/hisilicon/Makefile
> index 65b0bd7..708326d0 100644
> --- a/drivers/perf/pci/hisilicon/Makefile
> +++ b/drivers/perf/pci/hisilicon/Makefile
> @@ -1,3 +1,4 @@
>  # SPDX-License-Identifier: GPL-2.0-only
>  
>  obj-$(CONFIG_HISI_PCIE_PMU) += hisi_pcie_pmu.o
> +obj-$(CONFIG_HNS3_PMU) += hns3_pmu.o
> diff --git a/drivers/perf/pci/hisilicon/hns3_pmu.c b/drivers/perf/pci/hisilicon/hns3_pmu.c
> new file mode 100644
> index 0000000..eddd410
> --- /dev/null
> +++ b/drivers/perf/pci/hisilicon/hns3_pmu.c
> @@ -0,0 +1,1586 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * This driver adds support for HNS3 PMU iEP device. Related perf events are
> + * bandwidth, latency, packet rate, interrupt rate etc.
> + *
> + * Copyright (C) 2021 HiSilicon Limited
> + */
> +#include <linux/bitfield.h>
> +#include <linux/bitmap.h>
> +#include <linux/bug.h>
> +#include <linux/cpuhotplug.h>
> +#include <linux/cpumask.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/iopoll.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 <linux/smp.h>
> +
> +/* registers offset address */
> +#define HNS3_PMU_REG_GLOBAL_CTRL		0x0000
> +#define HNS3_PMU_REG_CLOCK_FREQ			0x0020
> +#define HNS3_PMU_REG_BDF			0x0FE0
> +#define HNS3_PMU_REG_VERSION			0x0FE4
> +#define HNS3_PMU_REG_DEVICE_ID			0x0FE8
> +
> +#define HNS3_PMU_REG_EVENT_OFFSET		0x1000
> +#define HNS3_PMU_REG_EVENT_SIZE			0x1000
> +#define HNS3_PMU_REG_EVENT_CTRL_LOW		0x00
> +#define HNS3_PMU_REG_EVENT_CTRL_HIGH		0x04
> +#define HNS3_PMU_REG_EVENT_INTR_STATUS		0x08
> +#define HNS3_PMU_REG_EVENT_INTR_MASK		0x0C
> +#define HNS3_PMU_REG_EVENT_COUNTER		0x10
> +#define HNS3_PMU_REG_EVENT_EXT_COUNTER		0x18
> +#define HNS3_PMU_REG_EVENT_QID_CTRL		0x28
> +#define HNS3_PMU_REG_EVENT_QID_PARA		0x2C
> +
> +#define HNS3_PMU_FILTER_SUPPORT_GLOBAL		BIT(0)
> +#define HNS3_PMU_FILTER_SUPPORT_PORT		BIT(1)
> +#define HNS3_PMU_FILTER_SUPPORT_PORT_TC		BIT(2)
> +#define HNS3_PMU_FILTER_SUPPORT_FUNC		BIT(3)
> +#define HNS3_PMU_FILTER_SUPPORT_FUNC_QUEUE	BIT(4)
> +#define HNS3_PMU_FILTER_SUPPORT_FUNC_INTR	BIT(5)
> +
> +#define HNS3_PMU_FILTER_ALL_TC			0xF
> +#define HNS3_PMU_FILTER_ALL_QUEUE		0xFFFF
> +
> +#define HNS3_PMU_CTRL_SUBEVENT_S		4
> +#define HNS3_PMU_CTRL_FILTER_MODE_S		24
> +
> +#define HNS3_PMU_GLOBAL_START			BIT(0)
> +
> +#define HNS3_PMU_EVENT_STATUS_RESET		BIT(11)
> +#define HNS3_PMU_EVENT_EN			BIT(12)
> +#define HNS3_PMU_EVENT_OVERFLOW_RESTART		BIT(15)
> +
> +#define HNS3_PMU_QID_PARA_FUNC_S		0
> +#define HNS3_PMU_QID_PARA_QUEUE_S		16
> +
> +#define HNS3_PMU_QID_CTRL_REQ_ENABLE		BIT(0)
> +#define HNS3_PMU_QID_CTRL_DONE			BIT(1)
> +#define HNS3_PMU_QID_CTRL_MISS			BIT(2)
> +
> +#define HNS3_PMU_INTR_MASK_OVERFLOW		BIT(1)
> +
> +#define HNS3_PMU_MAX_COUNTERS			8
> +
> +#define HNS3_PMU_INVALID_CPU_ID			(-1)
> +
> +enum hns3_pmu_event_type {
> +	HNS3_PMU_EVENT_TYPE_BANDWIDTH,
> +	HNS3_PMU_EVENT_TYPE_PACKET_RATE,
> +	HNS3_PMU_EVENT_TYPE_LATENCY,
> +	HNS3_PMU_EVENT_TYPE_INTR_RATE,
> +};
> +
> +enum hns3_pmu_bandwidth_subevent_code {
> +	HNS3_PMU_SUBEVT_BW_IGU_SSU = 0,
> +	HNS3_PMU_SUBEVT_BW_SSU_EGU = 1,
> +	HNS3_PMU_SUBEVT_BW_SSU_RPU = 2,
> +	HNS3_PMU_SUBEVT_BW_TPU_SSU = 5,
> +	HNS3_PMU_SUBEVT_BW_RPU_RCBRX = 6,
> +	HNS3_PMU_SUBEVT_BW_RCBTX_TXSCH = 8,
> +	HNS3_PMU_SUBEVT_BW_WR_FBD = 9,
> +	HNS3_PMU_SUBEVT_BW_WR_EBD = 10,
> +	HNS3_PMU_SUBEVT_BW_RD_FBD = 11,
> +	HNS3_PMU_SUBEVT_BW_RD_EBD = 12,
> +	HNS3_PMU_SUBEVT_BW_RD_PAY_M0 = 13,
> +	HNS3_PMU_SUBEVT_BW_RD_PAY_M1 = 14,
> +	HNS3_PMU_SUBEVT_BW_WR_PAY_M0 = 15,
> +	HNS3_PMU_SUBEVT_BW_WR_PAY_M1 = 16,
> +};
> +
> +enum hns3_pmu_packet_rate_subevent_code {
> +	HNS3_PMU_SUBEVT_PPS_IGU_SSU = 0,
> +	HNS3_PMU_SUBEVT_PPS_SSU_EGU = 1,
> +	HNS3_PMU_SUBEVT_PPS_SSU_RPU = 2,
> +	HNS3_PMU_SUBEVT_PPS_TPU_SSU = 5,
> +	HNS3_PMU_SUBEVT_PPS_RPU_RCBRX = 6,
> +	HNS3_PMU_SUBEVT_PPS_RCBTX_TPU = 7,
> +	HNS3_PMU_SUBEVT_PPS_RCBTX_TXSCH = 8,
> +	HNS3_PMU_SUBEVT_PPS_WR_FBD = 9,
> +	HNS3_PMU_SUBEVT_PPS_WR_EBD = 10,
> +	HNS3_PMU_SUBEVT_PPS_RD_FBD = 11,
> +	HNS3_PMU_SUBEVT_PPS_RD_EBD = 12,
> +	HNS3_PMU_SUBEVT_PPS_RD_PAY_M0 = 13,
> +	HNS3_PMU_SUBEVT_PPS_RD_PAY_M1 = 14,
> +	HNS3_PMU_SUBEVT_PPS_WR_PAY_M0 = 15,
> +	HNS3_PMU_SUBEVT_PPS_WR_PAY_M1 = 16,
> +	HNS3_PMU_SUBEVT_PPS_NICROH_TX_PRE = 17,
> +	HNS3_PMU_SUBEVT_PPS_NICROH_RX_PRE = 18,
> +};
> +
> +enum hns3_pmu_latency_subevent_code {
> +	HNS3_PMU_SUBEVT_DLY_RX_INTR = 0,
> +	HNS3_PMU_SUBEVT_DLY_TX_PUSH = 2,
> +	HNS3_PMU_SUBEVT_DLY_TX = 4,
> +	HNS3_PMU_SUBEVT_DLY_SSU_TX_NIC = 6,
> +	HNS3_PMU_SUBEVT_DLY_SSU_RX_NIC = 8,
> +	HNS3_PMU_SUBEVT_DLY_RPU = 14,
> +	HNS3_PMU_SUBEVT_DLY_TPU = 15,
> +	HNS3_PMU_SUBEVT_DLY_RPE = 16,
> +	HNS3_PMU_SUBEVT_DLY_TPE = 17,
> +	HNS3_PMU_SUBEVT_DLY_TPE_PUSH = 18,
> +	HNS3_PMU_SUBEVT_DLY_WR_FBD = 19,
> +	HNS3_PMU_SUBEVT_DLY_WR_EBD = 20,
> +	HNS3_PMU_SUBEVT_DLY_RD_FBD = 21,
> +	HNS3_PMU_SUBEVT_DLY_RD_EBD = 22,
> +	HNS3_PMU_SUBEVT_DLY_RD_PAY_M0 = 23,
> +	HNS3_PMU_SUBEVT_DLY_RD_PAY_M1 = 24,
> +	HNS3_PMU_SUBEVT_DLY_WR_PAY_M0 = 25,
> +	HNS3_PMU_SUBEVT_DLY_WR_PAY_M1 = 26,
> +	HNS3_PMU_SUBEVT_DLY_MSIX_WRITE = 28,
> +};
> +
> +enum hns3_pmu_interrupt_rate_subevent_code {
> +	HNS3_PMU_SUBEVT_INTR_MSIX_NIC = 0,
> +	HNS3_PMU_SUBEVT_INTR_MERGE = 2,
> +};
> +
> +/* filter mode supported by each bandwidth subevent code */
> +#define HNS3_PMU_FILTER_BW_IGU_SSU		0x07
> +#define HNS3_PMU_FILTER_BW_SSU_EGU		0x07
> +#define HNS3_PMU_FILTER_BW_SSU_RPU		0x1F
> +#define HNS3_PMU_FILTER_BW_TPU_SSU		0x1F
> +#define HNS3_PMU_FILTER_BW_RPU_RCBRX		0x11
> +#define HNS3_PMU_FILTER_BW_RCBTX_TXSCH		0x1B
> +#define HNS3_PMU_FILTER_BW_WR_FBD		0x1B
> +#define HNS3_PMU_FILTER_BW_WR_EBD		0x1B
> +#define HNS3_PMU_FILTER_BW_RD_FBD		0x1B
> +#define HNS3_PMU_FILTER_BW_RD_EBD		0x1B
> +#define HNS3_PMU_FILTER_BW_RD_PAY_M0		0x01
> +#define HNS3_PMU_FILTER_BW_RD_PAY_M1		0x01
> +#define HNS3_PMU_FILTER_BW_WR_PAY_M0		0x01
> +#define HNS3_PMU_FILTER_BW_WR_PAY_M1		0x01
> +
> +/* filter mode supported by each packet rate subevent code */
> +#define HNS3_PMU_FILTER_PPS_IGU_SSU		0x07
> +#define HNS3_PMU_FILTER_PPS_SSU_EGU		0x07
> +#define HNS3_PMU_FILTER_PPS_SSU_RPU		0x1F
> +#define HNS3_PMU_FILTER_PPS_TPU_SSU		0x1F
> +#define HNS3_PMU_FILTER_PPS_RPU_RCBRX		0x11
> +#define HNS3_PMU_FILTER_PPS_RCBTX_TPU		0x1F
> +#define HNS3_PMU_FILTER_PPS_RCBTX_TXSCH		0x1B
> +#define HNS3_PMU_FILTER_PPS_WR_FBD		0x1B
> +#define HNS3_PMU_FILTER_PPS_WR_EBD		0x1B
> +#define HNS3_PMU_FILTER_PPS_RD_FBD		0x1B
> +#define HNS3_PMU_FILTER_PPS_RD_EBD		0x1B
> +#define HNS3_PMU_FILTER_PPS_RD_PAY_M0		0x01
> +#define HNS3_PMU_FILTER_PPS_RD_PAY_M1		0x01
> +#define HNS3_PMU_FILTER_PPS_WR_PAY_M0		0x01
> +#define HNS3_PMU_FILTER_PPS_WR_PAY_M1		0x01
> +#define HNS3_PMU_FILTER_PPS_NICROH_TX_PRE	0x21
> +#define HNS3_PMU_FILTER_PPS_NICROH_RX_PRE	0x21
> +
> +/* filter mode supported by each latency subevent code */
> +#define HNS3_PMU_FILTER_DLY_RX_INTR		0x01
> +#define HNS3_PMU_FILTER_DLY_TX_PUSH		0x01
> +#define HNS3_PMU_FILTER_DLY_TX			0x01
> +#define HNS3_PMU_FILTER_DLY_SSU_TX_NIC		0x07
> +#define HNS3_PMU_FILTER_DLY_SSU_RX_NIC		0x07
> +#define HNS3_PMU_FILTER_DLY_RPU			0x11
> +#define HNS3_PMU_FILTER_DLY_TPU			0x1F
> +#define HNS3_PMU_FILTER_DLY_RPE			0x01
> +#define HNS3_PMU_FILTER_DLY_TPE			0x1B
> +#define HNS3_PMU_FILTER_DLY_TPE_PUSH		0x1B
> +#define HNS3_PMU_FILTER_DLY_WR_FBD		0x1B
> +#define HNS3_PMU_FILTER_DLY_WR_EBD		0x11
> +#define HNS3_PMU_FILTER_DLY_RD_FBD		0x1B
> +#define HNS3_PMU_FILTER_DLY_RD_EBD		0x1B
> +#define HNS3_PMU_FILTER_DLY_RD_PAY_M0		0x01
> +#define HNS3_PMU_FILTER_DLY_RD_PAY_M1		0x01
> +#define HNS3_PMU_FILTER_DLY_WR_PAY_M0		0x01
> +#define HNS3_PMU_FILTER_DLY_WR_PAY_M1		0x01
> +#define HNS3_PMU_FILTER_DLY_MSIX_WRITE		0x01
> +
> +/* filter mode supported by each interrupt rate subevent code */
> +#define HNS3_PMU_FILTER_INTR_MSIX_NIC		0x01
> +#define HNS3_PMU_FILTER_INTR_MERGE		0x01
> +
> +enum hns3_pmu_hw_filter_mode {
> +	HNS3_PMU_HW_FILTER_GLOBAL,
> +	HNS3_PMU_HW_FILTER_PORT,
> +	HNS3_PMU_HW_FILTER_PORT_TC,
> +	HNS3_PMU_HW_FILTER_FUNC,
> +	HNS3_PMU_HW_FILTER_FUNC_QUEUE,
> +	HNS3_PMU_HW_FILTER_FUNC_INTR,
> +};
> +
> +struct hns3_pmu_event_attr {
> +	u8 event;
> +	u8 subevent;
> +	u16 filter_support;
> +};
> +
> +struct hns3_pmu {
> +	struct perf_event *hw_events[HNS3_PMU_MAX_COUNTERS];
> +	struct hlist_node node;
> +	struct pci_dev *pdev;
> +	struct pmu pmu;
> +	void __iomem *base;
> +	int irq;
> +	int on_cpu;
> +	u32 identifier;
> +	u32 hw_clk_freq; /* hardware clock frequency of PMU */
> +	/* maximum and minimun bdf allowed by PMU */
> +	u16 bdf_min;
> +	u16 bdf_max;
> +};
> +
> +#define to_hns3_pmu(p)  (container_of((p), struct hns3_pmu, pmu))
> +#define attr_to_dattr(a) (container_of((a), struct device_attribute, attr))
> +#define dattr_to_eattr(d) (container_of((d), struct dev_ext_attribute, attr))
> +
> +#define GET_PCI_DEVFN(bdf)  ((bdf) & 0xFF)
> +
> +#define FILTER_CONDITION_PORT(port) ((1 << (port)) & 0xFF)
> +#define FILTER_CONDITION_PORT_TC(port, tc) (((port) << 3) | ((tc) & 0x07))
> +#define FILTER_CONDITION_FUNC_INTR(func, intr) (((intr) << 8) | (func))
> +
> +#define BYTES_TO_BITS(bytes)		((bytes) * 8)
> +
> +#define HNS3_PMU_FILTER_ATTR(_name, _config, _start, _end)            \
> +	static inline u64 hns3_get_##_name(struct perf_event *event)  \
> +	{                                                             \
> +		return FIELD_GET(GENMASK_ULL(_end, _start),           \
> +				 event->attr._config);                \
> +	}
> +
> +HNS3_PMU_FILTER_ATTR(event, config, 0, 7);
> +HNS3_PMU_FILTER_ATTR(subevent, config, 8, 15);
> +HNS3_PMU_FILTER_ATTR(port, config1, 0, 3);
> +HNS3_PMU_FILTER_ATTR(tc, config1, 4, 7);
> +HNS3_PMU_FILTER_ATTR(bdf, config1, 8, 23);
> +HNS3_PMU_FILTER_ATTR(queue, config1, 24, 39);
> +HNS3_PMU_FILTER_ATTR(intr, config1, 40, 51);
> +HNS3_PMU_FILTER_ATTR(global, config1, 52, 52);
> +
> +#define HNS3_CONSTRUCT_BW_EVENT(_name)                                    \
> +	(&(struct hns3_pmu_event_attr) {HNS3_PMU_EVENT_TYPE_BANDWIDTH,    \
> +					HNS3_PMU_SUBEVT_BW_##_name,       \
> +					HNS3_PMU_FILTER_BW_##_name})
> +#define HNS3_CONSTRUCT_PPS_EVENT(_name)                                   \
> +	(&(struct hns3_pmu_event_attr) {HNS3_PMU_EVENT_TYPE_PACKET_RATE,  \
> +					HNS3_PMU_SUBEVT_PPS_##_name,      \
> +					HNS3_PMU_FILTER_PPS_##_name})
> +#define HNS3_CONSTRUCT_DLY_EVENT(_name)                                   \
> +	(&(struct hns3_pmu_event_attr) {HNS3_PMU_EVENT_TYPE_LATENCY,      \
> +					HNS3_PMU_SUBEVT_DLY_##_name,      \
> +					HNS3_PMU_FILTER_DLY_##_name})
> +#define HNS3_CONSTRUCT_INTR_EVENT(_name)                                  \
> +	(&(struct hns3_pmu_event_attr) {HNS3_PMU_EVENT_TYPE_INTR_RATE,    \
> +					HNS3_PMU_SUBEVT_INTR_##_name,     \
> +					HNS3_PMU_FILTER_INTR_##_name})
> +
> +static ssize_t hns3_pmu_format_show(struct device *dev,
> +				    struct device_attribute *attr, char *buf)
> +{
> +	struct dev_ext_attribute *eattr;
> +
> +	eattr = container_of(attr, struct dev_ext_attribute, attr);
> +
> +	return sysfs_emit(buf, "%s\n", (char *)eattr->var);
> +}
> +
> +static ssize_t hns3_pmu_event_show(struct device *dev,
> +				   struct device_attribute *attr, char *buf)
> +{
> +	struct hns3_pmu_event_attr *event;
> +	struct dev_ext_attribute *eattr;
> +	u16 config;
> +
> +	eattr = container_of(attr, struct dev_ext_attribute, attr);
> +	event = (struct hns3_pmu_event_attr *)eattr->var;
> +	config = event->event << 8 | event->subevent;
> +
> +	return sysfs_emit(buf, "config=0x%04x\n", config);
> +}
> +
> +static ssize_t hns3_pmu_filter_mode_show(struct device *dev,
> +					 struct device_attribute *attr,
> +					 char *buf)
> +{
> +	struct hns3_pmu_event_attr *event;
> +	struct dev_ext_attribute *eattr;
> +	int len;
> +
> +	eattr = container_of(attr, struct dev_ext_attribute, attr);
> +	event = (struct hns3_pmu_event_attr *)eattr->var;
> +
> +	len = sysfs_emit_at(buf, 0, "filter mode supported: ");

As mentioned in the documentation review, normally sysfs files
don't have such and intro string.  Is this based on an existing
driver?

> +	if (event->filter_support & HNS3_PMU_FILTER_SUPPORT_GLOBAL)
> +		len += sysfs_emit_at(buf, len, "global/");
> +	if (event->filter_support & HNS3_PMU_FILTER_SUPPORT_PORT)
> +		len += sysfs_emit_at(buf, len, "port/");
> +	if (event->filter_support & HNS3_PMU_FILTER_SUPPORT_PORT_TC)
> +		len += sysfs_emit_at(buf, len, "port-tc/");
> +	if (event->filter_support & HNS3_PMU_FILTER_SUPPORT_FUNC)
> +		len += sysfs_emit_at(buf, len, "func/");
> +	if (event->filter_support & HNS3_PMU_FILTER_SUPPORT_FUNC_QUEUE)
> +		len += sysfs_emit_at(buf, len, "func-queue/");
> +	if (event->filter_support & HNS3_PMU_FILTER_SUPPORT_FUNC_INTR)
> +		len += sysfs_emit_at(buf, len, "func-intr/");
> +
> +	len += sysfs_emit_at(buf, len, "\n");
> +
> +	return len;
> +}
> +
> +#define HNS3_PMU_ATTR(_name, _func, _config)				\
> +	(&((struct dev_ext_attribute[]) {				\
> +		{ __ATTR(_name, 0444, _func, NULL), (void *)_config }	\
> +	})[0].attr.attr)
> +
> +#define HNS3_PMU_FORMAT_ATTR(_name, _format) \
> +	HNS3_PMU_ATTR(_name, hns3_pmu_format_show, (void *)_format)
> +#define HNS3_PMU_EVENT_ATTR(_name, _event) \
> +	HNS3_PMU_ATTR(_name, hns3_pmu_event_show, (void *)_event)
> +
> +static u8 hns3_pmu_hw_filter_modes[] = {
> +	HNS3_PMU_HW_FILTER_GLOBAL,
> +	HNS3_PMU_HW_FILTER_PORT,
> +	HNS3_PMU_HW_FILTER_PORT_TC,
> +	HNS3_PMU_HW_FILTER_FUNC,
> +	HNS3_PMU_HW_FILTER_FUNC_QUEUE,
> +	HNS3_PMU_HW_FILTER_FUNC_INTR
> +};
> +
> +#define HNS3_PMU_SET_HW_FILTER(_hwc, _mode) \
> +	((_hwc)->addr_filters = (void *)&hns3_pmu_hw_filter_modes[(_mode)])
> +
> +static ssize_t identifier_show(struct device *dev,
> +			       struct device_attribute *attr, char *buf)
> +{
> +	struct hns3_pmu *hns3_pmu;
> +
> +	hns3_pmu = to_hns3_pmu(dev_get_drvdata(dev));
> +
> +	return sysfs_emit(buf, "0x%x\n", hns3_pmu->identifier);
> +}
> +static DEVICE_ATTR_RO(identifier);
> +
> +static ssize_t cpumask_show(struct device *dev, struct device_attribute *attr,
> +			    char *buf)
> +{
> +	struct hns3_pmu *hns3_pmu = to_hns3_pmu(dev_get_drvdata(dev));
> +
> +	return sysfs_emit(buf, "%d\n", hns3_pmu->on_cpu);
> +}
> +static DEVICE_ATTR_RO(cpumask);
> +
> +static struct attribute *hns3_pmu_events_attr[] = {
> +	/* bandwidth events */
> +	HNS3_PMU_EVENT_ATTR(bw_igu_ssu,
> +			    HNS3_CONSTRUCT_BW_EVENT(IGU_SSU)),

I'd drop the CONSTRUCT part of this as it's fairly obvious and then 
each of these will easily fit on oneline making this both more
readable and shorter.

> +	HNS3_PMU_EVENT_ATTR(bw_ssu_egu,
> +			    HNS3_CONSTRUCT_BW_EVENT(SSU_EGU)),
> +	HNS3_PMU_EVENT_ATTR(bw_ssu_rpu,
> +			    HNS3_CONSTRUCT_BW_EVENT(SSU_RPU)),
> +	HNS3_PMU_EVENT_ATTR(bw_tpu_ssu,
> +			    HNS3_CONSTRUCT_BW_EVENT(TPU_SSU)),
> +	HNS3_PMU_EVENT_ATTR(bw_rpu_rcbrx,
> +			    HNS3_CONSTRUCT_BW_EVENT(RPU_RCBRX)),
> +	HNS3_PMU_EVENT_ATTR(bw_rcbtx_txsch,
> +			    HNS3_CONSTRUCT_BW_EVENT(RCBTX_TXSCH)),
> +	HNS3_PMU_EVENT_ATTR(bw_wr_fbd,
> +			    HNS3_CONSTRUCT_BW_EVENT(WR_FBD)),
> +	HNS3_PMU_EVENT_ATTR(bw_wr_ebd,
> +			    HNS3_CONSTRUCT_BW_EVENT(WR_EBD)),
> +	HNS3_PMU_EVENT_ATTR(bw_rd_fbd,
> +			    HNS3_CONSTRUCT_BW_EVENT(RD_FBD)),
> +	HNS3_PMU_EVENT_ATTR(bw_rd_ebd,
> +			    HNS3_CONSTRUCT_BW_EVENT(RD_EBD)),
> +	HNS3_PMU_EVENT_ATTR(bw_rd_pay_m0,
> +			    HNS3_CONSTRUCT_BW_EVENT(RD_PAY_M0)),
> +	HNS3_PMU_EVENT_ATTR(bw_rd_pay_m1,
> +			    HNS3_CONSTRUCT_BW_EVENT(RD_PAY_M1)),
> +	HNS3_PMU_EVENT_ATTR(bw_wr_pay_m0,
> +			    HNS3_CONSTRUCT_BW_EVENT(WR_PAY_M0)),
> +	HNS3_PMU_EVENT_ATTR(bw_wr_pay_m1,
> +			    HNS3_CONSTRUCT_BW_EVENT(WR_PAY_M1)),
> +
> +	/* packet rate events */
> +	HNS3_PMU_EVENT_ATTR(pps_igu_ssu,
> +			    HNS3_CONSTRUCT_PPS_EVENT(IGU_SSU)),
> +	HNS3_PMU_EVENT_ATTR(pps_ssu_egu,
> +			    HNS3_CONSTRUCT_PPS_EVENT(SSU_EGU)),
> +	HNS3_PMU_EVENT_ATTR(pps_ssu_rpu,
> +			    HNS3_CONSTRUCT_PPS_EVENT(SSU_RPU)),
> +	HNS3_PMU_EVENT_ATTR(pps_tpu_ssu,
> +			    HNS3_CONSTRUCT_PPS_EVENT(TPU_SSU)),
> +	HNS3_PMU_EVENT_ATTR(pps_rpu_rcbrx,
> +			    HNS3_CONSTRUCT_PPS_EVENT(RPU_RCBRX)),
> +	HNS3_PMU_EVENT_ATTR(pps_rcbtx_tpu,
> +			    HNS3_CONSTRUCT_PPS_EVENT(RCBTX_TPU)),
> +	HNS3_PMU_EVENT_ATTR(pps_rcbtx_txsch,
> +			    HNS3_CONSTRUCT_PPS_EVENT(RCBTX_TXSCH)),
> +	HNS3_PMU_EVENT_ATTR(pps_wr_fbd,
> +			    HNS3_CONSTRUCT_PPS_EVENT(WR_FBD)),
> +	HNS3_PMU_EVENT_ATTR(pps_wr_ebd,
> +			    HNS3_CONSTRUCT_PPS_EVENT(WR_EBD)),
> +	HNS3_PMU_EVENT_ATTR(pps_rd_fbd,
> +			    HNS3_CONSTRUCT_PPS_EVENT(RD_FBD)),
> +	HNS3_PMU_EVENT_ATTR(pps_rd_ebd,
> +			    HNS3_CONSTRUCT_PPS_EVENT(RD_EBD)),
> +	HNS3_PMU_EVENT_ATTR(pps_rd_pay_m0,
> +			    HNS3_CONSTRUCT_PPS_EVENT(RD_PAY_M0)),
> +	HNS3_PMU_EVENT_ATTR(pps_rd_pay_m1,
> +			    HNS3_CONSTRUCT_PPS_EVENT(RD_PAY_M1)),
> +	HNS3_PMU_EVENT_ATTR(pps_wr_pay_m0,
> +			    HNS3_CONSTRUCT_PPS_EVENT(WR_PAY_M0)),
> +	HNS3_PMU_EVENT_ATTR(pps_wr_pay_m1,
> +			    HNS3_CONSTRUCT_PPS_EVENT(WR_PAY_M1)),
> +	HNS3_PMU_EVENT_ATTR(pps_intr_nicroh_tx_pre,
> +			    HNS3_CONSTRUCT_PPS_EVENT(NICROH_TX_PRE)),
> +	HNS3_PMU_EVENT_ATTR(pps_intr_nicroh_rx_pre,
> +			    HNS3_CONSTRUCT_PPS_EVENT(NICROH_RX_PRE)),
> +
> +	/* latency events */
> +	HNS3_PMU_EVENT_ATTR(dly_rx_mac_to_intr,
> +			    HNS3_CONSTRUCT_DLY_EVENT(RX_INTR)),
> +	HNS3_PMU_EVENT_ATTR(dly_tx_push_to_mac,
> +			    HNS3_CONSTRUCT_DLY_EVENT(TX_PUSH)),
> +	HNS3_PMU_EVENT_ATTR(dly_tx_normal_to_mac,
> +			    HNS3_CONSTRUCT_DLY_EVENT(TX)),
> +	HNS3_PMU_EVENT_ATTR(dly_ssu_tx_th_nic,
> +			    HNS3_CONSTRUCT_DLY_EVENT(SSU_TX_NIC)),
> +	HNS3_PMU_EVENT_ATTR(dly_ssu_rx_th_nic,
> +			    HNS3_CONSTRUCT_DLY_EVENT(SSU_RX_NIC)),
> +	HNS3_PMU_EVENT_ATTR(dly_rpu,
> +			    HNS3_CONSTRUCT_DLY_EVENT(RPU)),
> +	HNS3_PMU_EVENT_ATTR(dly_tpu,
> +			    HNS3_CONSTRUCT_DLY_EVENT(TPU)),
> +	HNS3_PMU_EVENT_ATTR(dly_rpe,
> +			    HNS3_CONSTRUCT_DLY_EVENT(RPE)),
> +	HNS3_PMU_EVENT_ATTR(dly_tpe_normal,
> +			    HNS3_CONSTRUCT_DLY_EVENT(TPE)),
> +	HNS3_PMU_EVENT_ATTR(dly_tpe_push,
> +			    HNS3_CONSTRUCT_DLY_EVENT(TPE_PUSH)),
> +	HNS3_PMU_EVENT_ATTR(dly_wr_fbd,
> +			    HNS3_CONSTRUCT_DLY_EVENT(WR_FBD)),
> +	HNS3_PMU_EVENT_ATTR(dly_wr_ebd,
> +			    HNS3_CONSTRUCT_DLY_EVENT(WR_EBD)),
> +	HNS3_PMU_EVENT_ATTR(dly_rd_fbd,
> +			    HNS3_CONSTRUCT_DLY_EVENT(RD_FBD)),
> +	HNS3_PMU_EVENT_ATTR(dly_rd_ebd,
> +			    HNS3_CONSTRUCT_DLY_EVENT(RD_EBD)),
> +	HNS3_PMU_EVENT_ATTR(dly_rd_pay_m0,
> +			    HNS3_CONSTRUCT_DLY_EVENT(RD_PAY_M0)),
> +	HNS3_PMU_EVENT_ATTR(dly_rd_pay_m1,
> +			    HNS3_CONSTRUCT_DLY_EVENT(RD_PAY_M1)),
> +	HNS3_PMU_EVENT_ATTR(dly_wr_pay_m0,
> +			    HNS3_CONSTRUCT_DLY_EVENT(WR_PAY_M0)),
> +	HNS3_PMU_EVENT_ATTR(dly_wr_pay_m1,
> +			    HNS3_CONSTRUCT_DLY_EVENT(WR_PAY_M1)),
> +	HNS3_PMU_EVENT_ATTR(dly_msix_write,
> +			    HNS3_CONSTRUCT_DLY_EVENT(MSIX_WRITE)),
> +
> +	/* interrupt rate events */
> +	HNS3_PMU_EVENT_ATTR(pps_intr_msix_nic,
> +			    HNS3_CONSTRUCT_INTR_EVENT(MSIX_NIC)),
> +	HNS3_PMU_EVENT_ATTR(pps_intr_merge_nicroh,
> +			    HNS3_CONSTRUCT_INTR_EVENT(MERGE)),
> +	NULL
> +};
> +
> +static struct attribute_group hns3_pmu_events_group = {
> +	.name = "events",
> +	.attrs = hns3_pmu_events_attr,
> +};
> +
> +static struct attribute_group hns3_pmu_filter_mode_group = {
> +	.name = "filtermode",
> +};
> +
> +static struct attribute *hns3_pmu_format_attr[] = {
> +	HNS3_PMU_FORMAT_ATTR(event, "config:0-7"),
> +	HNS3_PMU_FORMAT_ATTR(subevent, "config:8-15"),
> +	HNS3_PMU_FORMAT_ATTR(port, "config1:0-3"),
> +	HNS3_PMU_FORMAT_ATTR(tc, "config1:4-7"),
> +	HNS3_PMU_FORMAT_ATTR(bdf, "config1:8-23"),
> +	HNS3_PMU_FORMAT_ATTR(queue, "config1:24-39"),
> +	HNS3_PMU_FORMAT_ATTR(intr, "config1:40-51"),
> +	HNS3_PMU_FORMAT_ATTR(global, "config1:52-52"),
> +	NULL
> +};
> +
> +static struct attribute_group hns3_pmu_format_group = {
> +	.name = "format",
> +	.attrs = hns3_pmu_format_attr,
> +};
> +
> +static struct attribute *hns3_pmu_cpumask_attrs[] = {
> +	&dev_attr_cpumask.attr,
> +	NULL
> +};
> +
> +static struct attribute_group hns3_pmu_cpumask_attr_group = {
> +	.attrs = hns3_pmu_cpumask_attrs,
> +};
> +
> +static struct attribute *hns3_pmu_identifier_attrs[] = {
> +	&dev_attr_identifier.attr,
> +	NULL
> +};
> +
> +static struct attribute_group hns3_pmu_identifier_attr_group = {
> +	.attrs = hns3_pmu_identifier_attrs,
> +};
> +
> +static const struct attribute_group *hns3_pmu_attr_groups[] = {
> +	&hns3_pmu_events_group,
> +	&hns3_pmu_filter_mode_group,
> +	&hns3_pmu_format_group,
> +	&hns3_pmu_cpumask_attr_group,
> +	&hns3_pmu_identifier_attr_group,
> +	NULL
> +};
> +
> +static int hns3_pmu_init_filter_mode_group(void)

I'm not sure I'm convinced doing this dynamically is a good idea.
Given it generates the same thing every time, is it really worth
taking this away from the static data we'd normally see.

> +{
> +	u32 group_size = ARRAY_SIZE(hns3_pmu_events_attr);
> +	struct dev_ext_attribute *eattr_filter;
> +	struct dev_ext_attribute *eattr_event;
> +	struct device_attribute *dattr_event;
> +	struct attribute **attr_filter;
> +	struct attribute *attr_event;
> +	u32 i;
> +
> +	attr_filter = kcalloc(group_size, sizeof(struct attribute *),
> +			      GFP_KERNEL);
> +	if (!attr_filter)
> +		return -ENOMEM;
> +
> +	eattr_filter = kcalloc(group_size - 1, sizeof(struct dev_ext_attribute),
> +			       GFP_KERNEL);
> +	if (!eattr_filter) {
> +		kfree(attr_filter);
> +		return -ENOMEM;
> +	}
> +
> +	for (i = 0; i < group_size - 1; i++) {
> +		attr_event = hns3_pmu_events_attr[i];
> +		dattr_event = attr_to_dattr(attr_event);
> +		eattr_event = dattr_to_eattr(dattr_event);
> +
> +		memcpy(&eattr_filter[i], eattr_event,
> +		       sizeof(struct dev_ext_attribute));
> +		eattr_filter[i].attr.show = hns3_pmu_filter_mode_show;
> +
> +		attr_filter[i] = &eattr_filter[i].attr.attr;
> +	}
> +
> +	hns3_pmu_filter_mode_group.attrs = attr_filter;
> +
> +	return 0;
> +}
> +
> +static void hns3_pmu_uinit_filter_mode_group(void)
> +{
> +	struct dev_ext_attribute *eattr;
> +	struct device_attribute *dattr;
> +	struct attribute **attrs;
> +
> +	attrs = hns3_pmu_filter_mode_group.attrs;
> +	dattr = attr_to_dattr(attrs[0]);
> +	eattr = dattr_to_eattr(dattr);
> +
> +	kfree(eattr);
> +	kfree(attrs);
> +
> +	hns3_pmu_filter_mode_group.attrs = NULL;
> +}
> +
> +static u32 hns3_pmu_get_offset(u32 offset, u32 idx)
> +{
> +	return offset + HNS3_PMU_REG_EVENT_OFFSET +
> +	       HNS3_PMU_REG_EVENT_SIZE * idx;
> +}
> +
> +static u32 hns3_pmu_readl(struct hns3_pmu *hns3_pmu, u32 reg_offset, u32 idx)
> +{
> +	u32 offset = hns3_pmu_get_offset(reg_offset, idx);
> +
> +	return readl(hns3_pmu->base + offset);
> +}
> +
> +static void hns3_pmu_writel(struct hns3_pmu *hns3_pmu, u32 reg_offset, u32 idx,
> +			    u32 val)
> +{
> +	u32 offset = hns3_pmu_get_offset(reg_offset, idx);
> +
> +	writel(val, hns3_pmu->base + offset);
> +}
> +
> +static u64 hns3_pmu_readq(struct hns3_pmu *hns3_pmu, u32 reg_offset, u32 idx)
> +{
> +	u32 offset = hns3_pmu_get_offset(reg_offset, idx);
> +
> +	return readq(hns3_pmu->base + offset);
> +}
> +
> +static void hns3_pmu_writeq(struct hns3_pmu *hns3_pmu, u32 reg_offset, u32 idx,
> +			    u64 val)
> +{
> +	u32 offset = hns3_pmu_get_offset(reg_offset, idx);
> +
> +	writeq(val, hns3_pmu->base + offset);
> +}
> +
> +static int hns3_pmu_get_event_idx(struct hns3_pmu *hns3_pmu)
> +{
> +	int idx;
> +
> +	for (idx = 0; idx < HNS3_PMU_MAX_COUNTERS; idx++)
> +		if (!hns3_pmu->hw_events[idx])
> +			return idx;
> +
> +	return -EBUSY;
> +}
> +
> +static bool hns3_pmu_valid_bdf(struct hns3_pmu *hns3_pmu, u16 bdf)
> +{
> +	struct pci_dev *pdev;
> +
> +	if (bdf < hns3_pmu->bdf_min || bdf > hns3_pmu->bdf_max) {
> +		pci_err(hns3_pmu->pdev, "Invalid EP device: %#x!\n", bdf);
> +		return false;
> +	}
> +
> +	pdev = pci_get_domain_bus_and_slot(pci_domain_nr(hns3_pmu->pdev->bus),
> +					   PCI_BUS_NUM(bdf),
> +					   GET_PCI_DEVFN(bdf));
> +	if (!pdev) {
> +		pci_err(hns3_pmu->pdev, "Nonexistent EP device: %#x!\n", bdf);
> +		return false;
> +	}
> +
> +	pci_dev_put(pdev);
> +	return true;
> +}
> +
> +static void hns3_pmu_set_qid_para(struct hns3_pmu *hns3_pmu, u32 idx, u16 bdf,
> +				  u16 queue)
> +{
> +	u32 val;
> +
> +	val = GET_PCI_DEVFN(bdf);
> +	val |= (u32)queue << HNS3_PMU_QID_PARA_QUEUE_S;
> +	hns3_pmu_writel(hns3_pmu, HNS3_PMU_REG_EVENT_QID_PARA, idx, val);
> +}
> +
> +static bool hns3_pmu_qid_req_start(struct hns3_pmu *hns3_pmu, u32 idx)
> +{
> +	bool queue_id_valid = false;
> +	u32 reg_qid_ctrl, val;
> +	int err;
> +
> +	/* enable queue id request */
> +	hns3_pmu_writel(hns3_pmu, HNS3_PMU_REG_EVENT_QID_CTRL, idx,
> +			HNS3_PMU_QID_CTRL_REQ_ENABLE);
> +
> +	reg_qid_ctrl = hns3_pmu_get_offset(HNS3_PMU_REG_EVENT_QID_CTRL, idx);
> +	err = readl_poll_timeout(hns3_pmu->base + reg_qid_ctrl, val,
> +				 val & HNS3_PMU_QID_CTRL_DONE, 1, 1000);
> +	if (err == -ETIMEDOUT) {
> +		pci_err(hns3_pmu->pdev, "QID request timeout!\n");
> +		goto out;
> +	}
> +
> +	queue_id_valid = (val & HNS3_PMU_QID_CTRL_MISS) == 0;
> +
> +out:
> +	/* disable qid request and clear status */
> +	hns3_pmu_writel(hns3_pmu, HNS3_PMU_REG_EVENT_QID_CTRL, idx, 0);
> +
> +	return queue_id_valid;
> +}
> +
> +static bool hns3_pmu_valid_queue(struct hns3_pmu *hns3_pmu, u32 idx, u16 bdf,
> +				 u16 queue)
> +{
> +	hns3_pmu_set_qid_para(hns3_pmu, idx, bdf, queue);
> +
> +	return hns3_pmu_qid_req_start(hns3_pmu, idx);
> +}
> +
> +static struct hns3_pmu_event_attr *hns3_pmu_get_pmu_event(u8 event, u8 subevent)
> +{
> +	struct hns3_pmu_event_attr *pmu_event;
> +	struct dev_ext_attribute *eattr;
> +	struct device_attribute *dattr;
> +	struct attribute *attr;
> +	u32 i;
> +
> +	for (i = 0; i < ARRAY_SIZE(hns3_pmu_events_attr) - 1; i++) {
> +		attr = hns3_pmu_events_attr[i];
> +		dattr = container_of(attr, struct device_attribute, attr);
> +		eattr = container_of(dattr, struct dev_ext_attribute, attr);
> +		pmu_event = (struct hns3_pmu_event_attr *)eattr->var;

var is a void * so there should be no need for an explicit cast.

> +
> +		if (event == pmu_event->event &&
> +		    subevent == pmu_event->subevent)
> +			return pmu_event;
> +	}
> +
> +	return NULL;
> +}
> +
> +static int hns3_pmu_set_func_mode(struct perf_event *event,
> +				  struct hns3_pmu *hns3_pmu)
> +{
> +	struct hw_perf_event *hwc = &event->hw;
> +	u16 bdf = hns3_get_bdf(event);
> +
> +	if (!hns3_pmu_valid_bdf(hns3_pmu, bdf))
> +		return -ENOENT;
> +
> +	HNS3_PMU_SET_HW_FILTER(hwc, HNS3_PMU_HW_FILTER_FUNC);
> +
> +	return 0;
> +}
> +
> +static int hns3_pmu_set_func_queue_mode(struct perf_event *event,
> +					struct hns3_pmu *hns3_pmu)
> +{
> +	struct hw_perf_event *hwc = &event->hw;
> +	u16 queue_id = hns3_get_queue(event);
> +	u16 bdf = hns3_get_bdf(event);
> +
> +	if (!hns3_pmu_valid_bdf(hns3_pmu, bdf))
> +		return -ENOENT;
> +
> +	if (!hns3_pmu_valid_queue(hns3_pmu, hwc->idx, bdf, queue_id)) {
> +		pci_err(hns3_pmu->pdev, "Invalid queue: %u\n", queue_id);
> +		return -ENOENT;
> +	}
> +
> +	HNS3_PMU_SET_HW_FILTER(hwc, HNS3_PMU_HW_FILTER_FUNC_QUEUE);
> +
> +	return 0;
> +}
> +
> +static bool
> +hns3_pmu_is_enabled_global_mode(struct perf_event *event,
> +				struct hns3_pmu_event_attr *pmu_event)
> +{
> +	u8 global = hns3_get_global(event);
> +
> +	return pmu_event->filter_support & HNS3_PMU_FILTER_SUPPORT_GLOBAL &&
> +	       !!global;
> +}
> +
> +static bool hns3_pmu_is_enabled_func_mode(struct perf_event *event,
> +					  struct hns3_pmu_event_attr *pmu_event)
> +{
> +	u16 queue_id = hns3_get_queue(event);
> +	u16 bdf = hns3_get_bdf(event);
> +
> +	return pmu_event->filter_support & HNS3_PMU_FILTER_SUPPORT_FUNC &&
> +	       queue_id == HNS3_PMU_FILTER_ALL_QUEUE && !!bdf;
> +}
> +
> +static bool
> +hns3_pmu_is_enabled_func_queue_mode(struct perf_event *event,
> +				    struct hns3_pmu_event_attr *pmu_event)
> +{
> +	u16 queue_id = hns3_get_queue(event);
> +	u16 bdf = hns3_get_bdf(event);
> +
> +	return pmu_event->filter_support & HNS3_PMU_FILTER_SUPPORT_FUNC_QUEUE &&
> +	       queue_id != HNS3_PMU_FILTER_ALL_QUEUE && !!bdf;
> +}
> +
> +static bool hns3_pmu_is_enabled_port_mode(struct perf_event *event,
> +					  struct hns3_pmu_event_attr *pmu_event)
> +{
> +	u8 tc_id = hns3_get_tc(event);
> +
> +	return pmu_event->filter_support & HNS3_PMU_FILTER_SUPPORT_PORT &&
> +	       tc_id == HNS3_PMU_FILTER_ALL_TC;
> +}
> +
> +static bool
> +hns3_pmu_is_enabled_port_tc_mode(struct perf_event *event,
> +				 struct hns3_pmu_event_attr *pmu_event)
> +{
> +	u8 tc_id = hns3_get_tc(event);
> +
> +	return pmu_event->filter_support & HNS3_PMU_FILTER_SUPPORT_PORT_TC &&
> +	       tc_id != HNS3_PMU_FILTER_ALL_TC;
> +}
> +
> +static bool
> +hns3_pmu_is_enabled_func_intr_mode(struct perf_event *event,
> +				   struct hns3_pmu *hns3_pmu,
> +				   struct hns3_pmu_event_attr *pmu_event)
> +{
> +	u16 bdf = hns3_get_bdf(event);
> +
> +	return pmu_event->filter_support & HNS3_PMU_FILTER_SUPPORT_FUNC_INTR &&
> +	       hns3_pmu_valid_bdf(hns3_pmu, bdf);
> +}
> +
> +static int hns3_pmu_select_filter_mode(struct perf_event *event,
> +				       struct hns3_pmu *hns3_pmu)
> +{
> +	struct hns3_pmu_event_attr *pmu_event;
> +	struct hw_perf_event *hwc = &event->hw;
> +	u8 subevent_id = hns3_get_subevent(event);
> +	u8 event_id = hns3_get_event(event);
> +
> +	pmu_event = hns3_pmu_get_pmu_event(event_id, subevent_id);
> +	if (!pmu_event) {
> +		pci_err(hns3_pmu->pdev, "Invalid pmu event\n");
> +		return -ENOENT;
> +	}
> +
> +	if (hns3_pmu_is_enabled_global_mode(event, pmu_event)) {
> +		HNS3_PMU_SET_HW_FILTER(hwc, HNS3_PMU_HW_FILTER_GLOBAL);
> +		return 0;
> +	}
> +
> +	if (hns3_pmu_is_enabled_func_mode(event, pmu_event))
> +		return hns3_pmu_set_func_mode(event, hns3_pmu);
> +
> +	if (hns3_pmu_is_enabled_func_queue_mode(event, pmu_event))
> +		return hns3_pmu_set_func_queue_mode(event, hns3_pmu);
> +
> +	if (hns3_pmu_is_enabled_port_mode(event, pmu_event)) {
> +		HNS3_PMU_SET_HW_FILTER(hwc, HNS3_PMU_HW_FILTER_PORT);
> +		return 0;
> +	}
> +
> +	if (hns3_pmu_is_enabled_port_tc_mode(event, pmu_event)) {
> +		HNS3_PMU_SET_HW_FILTER(hwc, HNS3_PMU_HW_FILTER_PORT_TC);
> +		return 0;
> +	}
> +
> +	if (hns3_pmu_is_enabled_func_intr_mode(event, hns3_pmu, pmu_event)) {
> +		HNS3_PMU_SET_HW_FILTER(hwc, HNS3_PMU_HW_FILTER_FUNC_INTR);
> +		return 0;
> +	}
> +
> +	return -ENOENT;
> +}
> +
> +static bool hns3_pmu_validate_event_group(struct perf_event *event)
> +{
> +	struct perf_event *leader = event->group_leader;
> +	struct perf_event *sibling;
> +	int counters = 1;
> +
> +	if (!is_software_event(leader)) {
> +		/*
> +		 * We must NOT create groups containing mixed PMUs, although
> +		 * software events are acceptable
> +		 */
> +		if (leader->pmu != event->pmu)
> +			return false;
> +
> +		/* Increase counter for the leader */
> +		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;
> +
> +		/* Increase counter for each sibling */
> +		counters++;
> +	}
> +
> +	return counters <= HNS3_PMU_MAX_COUNTERS;
> +}
> +
> +static u32 hns3_pmu_get_filter_condition(struct perf_event *event)
> +{
> +	struct hw_perf_event *hwc = &event->hw;
> +	u16 intr_id = hns3_get_intr(event);
> +	u8 port_id = hns3_get_port(event);
> +	u16 bdf = hns3_get_bdf(event);
> +	u8 tc_id = hns3_get_tc(event);
> +	u8 filter_mode;
> +	u32 filter = 0;
> +
> +	filter_mode = *(u8 *)hwc->addr_filters;
> +	switch (filter_mode) {
> +	case HNS3_PMU_HW_FILTER_PORT:
> +		filter = FILTER_CONDITION_PORT(port_id);
> +		break;
> +	case HNS3_PMU_HW_FILTER_PORT_TC:
> +		filter = FILTER_CONDITION_PORT_TC(port_id, tc_id);
> +		break;
> +	case HNS3_PMU_HW_FILTER_FUNC:
> +	case HNS3_PMU_HW_FILTER_FUNC_QUEUE:
> +		filter = GET_PCI_DEVFN(bdf);
> +		break;
> +	case HNS3_PMU_HW_FILTER_FUNC_INTR:
> +		filter = FILTER_CONDITION_FUNC_INTR(GET_PCI_DEVFN(bdf),
> +						    intr_id);
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	return filter;
> +}
> +
> +static void hns3_pmu_config_filter(struct perf_event *event)
> +{
> +	struct hns3_pmu *hns3_pmu = to_hns3_pmu(event->pmu);
> +	struct hw_perf_event *hwc = &event->hw;
> +	u8 filter_mode = *(u8 *)hwc->addr_filters;
> +	u8 subevent_id = hns3_get_subevent(event);
> +	u16 queue_id = hns3_get_queue(event);
> +	u8 event_id = hns3_get_event(event);
> +	u16 bdf = hns3_get_bdf(event);
> +	u32 idx = hwc->idx;
> +	u32 val;
> +
> +	val = event_id;
> +	val |= subevent_id << HNS3_PMU_CTRL_SUBEVENT_S;
> +	val |= filter_mode << HNS3_PMU_CTRL_FILTER_MODE_S;
> +	val |= HNS3_PMU_EVENT_OVERFLOW_RESTART;
> +	hns3_pmu_writel(hns3_pmu, HNS3_PMU_REG_EVENT_CTRL_LOW, idx, val);
> +
> +	val = hns3_pmu_get_filter_condition(event);
> +	hns3_pmu_writel(hns3_pmu, HNS3_PMU_REG_EVENT_CTRL_HIGH, idx, val);
> +
> +	if (filter_mode == HNS3_PMU_HW_FILTER_FUNC_QUEUE)
> +		hns3_pmu_set_qid_para(hns3_pmu, idx, bdf, queue_id);
> +}
> +
> +static void hns3_pmu_enable_counter(struct hns3_pmu *hns3_pmu,
> +				    struct hw_perf_event *hwc)
> +{
> +	u32 idx = hwc->idx;
> +	u32 val;
> +
> +	val = hns3_pmu_readl(hns3_pmu, HNS3_PMU_REG_EVENT_CTRL_LOW, idx);
> +	val |= HNS3_PMU_EVENT_EN;
> +	hns3_pmu_writel(hns3_pmu, HNS3_PMU_REG_EVENT_CTRL_LOW, idx, val);
> +}
> +
> +static void hns3_pmu_disable_counter(struct hns3_pmu *hns3_pmu,
> +				     struct hw_perf_event *hwc)
> +{
> +	u32 idx = hwc->idx;
> +	u32 val;
> +
> +	val = hns3_pmu_readl(hns3_pmu, HNS3_PMU_REG_EVENT_CTRL_LOW, idx);
> +	val &= ~HNS3_PMU_EVENT_EN;
> +	hns3_pmu_writel(hns3_pmu, HNS3_PMU_REG_EVENT_CTRL_LOW, idx, val);
> +}
> +
> +static void hns3_pmu_enable_intr(struct hns3_pmu *hns3_pmu,
> +				 struct hw_perf_event *hwc)
> +{
> +	u32 idx = hwc->idx;
> +	u32 val;
> +
> +	val = hns3_pmu_readl(hns3_pmu, HNS3_PMU_REG_EVENT_INTR_MASK, idx);
> +	val &= ~HNS3_PMU_INTR_MASK_OVERFLOW;
> +	hns3_pmu_writel(hns3_pmu, HNS3_PMU_REG_EVENT_INTR_MASK, idx, val);
> +}
> +
> +static void hns3_pmu_disable_intr(struct hns3_pmu *hns3_pmu,
> +				  struct hw_perf_event *hwc)
> +{
> +	u32 idx = hwc->idx;
> +	u32 val;
> +
> +	val = hns3_pmu_readl(hns3_pmu, HNS3_PMU_REG_EVENT_INTR_MASK, idx);
> +	val |= HNS3_PMU_INTR_MASK_OVERFLOW;
> +	hns3_pmu_writel(hns3_pmu, HNS3_PMU_REG_EVENT_INTR_MASK, idx, val);
> +}
> +
> +static void hns3_pmu_clear_intr_status(struct hns3_pmu *hns3_pmu, u32 idx)
> +{
> +	u32 val;
> +
> +	val = hns3_pmu_readl(hns3_pmu, HNS3_PMU_REG_EVENT_CTRL_LOW, idx);
> +	val |= HNS3_PMU_EVENT_STATUS_RESET;
> +	hns3_pmu_writel(hns3_pmu, HNS3_PMU_REG_EVENT_CTRL_LOW, idx, val);
> +
> +	val = hns3_pmu_readl(hns3_pmu, HNS3_PMU_REG_EVENT_CTRL_LOW, idx);
> +	val &= ~HNS3_PMU_EVENT_STATUS_RESET;
> +	hns3_pmu_writel(hns3_pmu, HNS3_PMU_REG_EVENT_CTRL_LOW, idx, val);
> +}
> +
> +static void hns3_pmu_read_counter(struct perf_event *event, u64 *cnt,
> +				  u64 *cnt_ext)
> +{
> +	struct hns3_pmu *hns3_pmu = to_hns3_pmu(event->pmu);
> +	u32 idx = event->hw.idx;
> +
> +	*cnt = hns3_pmu_readq(hns3_pmu, HNS3_PMU_REG_EVENT_COUNTER, idx);
> +	*cnt_ext = hns3_pmu_readq(hns3_pmu, HNS3_PMU_REG_EVENT_EXT_COUNTER,
> +				  idx);
> +}
> +
> +static void hns3_pmu_write_counter(struct perf_event *event, u64 cnt,
> +				   u64 cnt_ext)
> +{
> +	struct hns3_pmu *hns3_pmu = to_hns3_pmu(event->pmu);
> +	u32 idx = event->hw.idx;
> +
> +	hns3_pmu_writeq(hns3_pmu, HNS3_PMU_REG_EVENT_COUNTER, idx, cnt);
> +	hns3_pmu_writeq(hns3_pmu, HNS3_PMU_REG_EVENT_EXT_COUNTER, idx, cnt_ext);
> +}
> +
> +static void hns3_pmu_init_counter(struct perf_event *event)
> +{
> +	struct hw_perf_event *hwc = &event->hw;
> +	struct hw_perf_event_extra *hwc_ext;
> +
> +	hwc_ext = &hwc->extra_reg;
> +	local64_set(&hwc->prev_count, 0);
> +	hwc_ext->config = 0;
> +	hns3_pmu_write_counter(event, 0, 0);
> +}
> +
> +static u64 hns3_pmu_tick_to_ms(u32 hw_clk_freq, u64 ticks)
> +{
> +	u64 time_ms = ticks / (hw_clk_freq / 1000);
> +
> +	if (!time_ms)
> +		time_ms = 1;

Add comment to say why here.  If it actually happens we are going
to get some missleading results.

> +
> +	return time_ms;
> +}
> +
> +/*
> + * The performance calculation formula of all types of event is
> + *                 performance = data / data_ext.
> + * The arguments data and data_ext have different meanings for different types
> + * of events as follow:
> + * event_type             data                     data_ext

Format this so it's obvious there is a separation between this first line (titles)
and the data.

> + * bandwidth              byte number              cycles number
> + * packet rate            packet number            cycles number
> + * interrupt rate         interrupt number         cycles number
> + * latency                cycles number            packet number
> + */
> +static u64 hns3_pmu_get_performance(u8 event_type, u32 hw_clk_freq, u64 data,
> +				    u64 data_ext)
> +{
> +	u64 result;
> +
> +	if (!hw_clk_freq || !data || !data_ext)
> +		return 0;
> +
> +	switch (event_type) {
> +	case HNS3_PMU_EVENT_TYPE_BANDWIDTH:
> +		/* process data to set unit of bandwidth as "KBits/s" */
> +		result = data / hns3_pmu_tick_to_ms(hw_clk_freq, data_ext);
> +		result = BYTES_TO_BITS(result);
> +		break;
> +
> +	case HNS3_PMU_EVENT_TYPE_PACKET_RATE:
> +	case HNS3_PMU_EVENT_TYPE_INTR_RATE:
> +		/* process data to set unit as "pps" */
> +		result = data * 1000 /
> +			 hns3_pmu_tick_to_ms(hw_clk_freq, data_ext);
> +		break;
> +
> +	case HNS3_PMU_EVENT_TYPE_LATENCY:
> +		/* process data to set unit of latency as "ns" */
> +		result = data / data_ext;
> +		result = result * 1000000000 / hw_clk_freq;
> +		break;
> +
> +	default:
> +		result = data / data_ext;
> +		break;
> +	}
> +
> +	return result;
> +}
> +
> +static int hns3_pmu_event_init(struct perf_event *event)
> +{
> +	struct hns3_pmu *hns3_pmu = to_hns3_pmu(event->pmu);
> +	struct hw_perf_event *hwc = &event->hw;
> +	int idx;
> +	int ret;
> +
> +	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;
> +
> +	event->cpu = hns3_pmu->on_cpu;
> +
> +	idx = hns3_pmu_get_event_idx(hns3_pmu);
> +	if (idx < 0) {
> +		pci_err(hns3_pmu->pdev, "Up to %u events are supported!\n",
> +			HNS3_PMU_MAX_COUNTERS);
> +		return -EBUSY;
> +	}
> +
> +	hwc->idx = idx;
> +
> +	ret = hns3_pmu_select_filter_mode(event, hns3_pmu);
> +	if (ret) {
> +		pci_err(hns3_pmu->pdev, "Invalid filter, ret = %d.\n", ret);
> +		return ret;
> +	}
> +
> +	if (!hns3_pmu_validate_event_group(event)) {
> +		pci_err(hns3_pmu->pdev, "Invalid event group.\n");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static void hns3_pmu_read(struct perf_event *event)
> +{
> +	struct hns3_pmu *hns3_pmu = to_hns3_pmu(event->pmu);
> +	struct hw_perf_event *hwc = &event->hw;
> +	struct hw_perf_event_extra *hwc_ext;
> +	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;
> +		hns3_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 = hns3_pmu_get_performance(hns3_get_event(event),
> +					 hns3_pmu->hw_clk_freq,
> +					 new_cnt - prev_cnt,
> +					 new_cnt_ext - prev_cnt_ext);
> +
> +	local64_add(delta, &event->count);
> +}
> +
> +static void hns3_pmu_start(struct perf_event *event, int flags)
> +{
> +	struct hns3_pmu *hns3_pmu = to_hns3_pmu(event->pmu);
> +	struct hw_perf_event *hwc = &event->hw;
> +
> +	if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
> +		return;
> +
> +	WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
> +	hwc->state = 0;
> +
> +	hns3_pmu_config_filter(event);
> +	hns3_pmu_init_counter(event);
> +	hns3_pmu_enable_intr(hns3_pmu, hwc);
> +	hns3_pmu_enable_counter(hns3_pmu, hwc);
> +
> +	perf_event_update_userpage(event);
> +}
> +
> +static void hns3_pmu_stop(struct perf_event *event, int flags)
> +{
> +	struct hns3_pmu *hns3_pmu = to_hns3_pmu(event->pmu);
> +	struct hw_perf_event *hwc = &event->hw;
> +
> +	hns3_pmu_disable_counter(hns3_pmu, hwc);
> +	hns3_pmu_disable_intr(hns3_pmu, hwc);
> +
> +	WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
> +	hwc->state |= PERF_HES_STOPPED;
> +
> +	if (hwc->state & PERF_HES_UPTODATE)
> +		return;
> +
> +	/* Read hardware counter and update the perf counter statistics */
> +	hns3_pmu_read(event);
> +	hwc->state |= PERF_HES_UPTODATE;
> +}
> +
> +static int hns3_pmu_add(struct perf_event *event, int flags)
> +{
> +	struct hns3_pmu *hns3_pmu = to_hns3_pmu(event->pmu);
> +	struct hw_perf_event *hwc = &event->hw;
> +	int idx;
> +
> +	hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
> +
> +	/* Get an available counter index for counting */
> +	idx = hns3_pmu_get_event_idx(hns3_pmu);
> +	if (idx < 0)
> +		return idx;
> +
> +	hwc->idx = idx;
> +	hns3_pmu->hw_events[idx] = event;
> +
> +	if (flags & PERF_EF_START)
> +		hns3_pmu_start(event, PERF_EF_RELOAD);
> +
> +	return 0;
> +}
> +
> +static void hns3_pmu_del(struct perf_event *event, int flags)
> +{
> +	struct hns3_pmu *hns3_pmu = to_hns3_pmu(event->pmu);
> +	struct hw_perf_event *hwc = &event->hw;
> +
> +	hns3_pmu_stop(event, PERF_EF_UPDATE);
> +	hns3_pmu->hw_events[hwc->idx] = NULL;
> +	perf_event_update_userpage(event);
> +}
> +
> +static void hns3_pmu_enable(struct pmu *pmu)
> +{
> +	struct hns3_pmu *hns3_pmu = to_hns3_pmu(pmu);
> +	u32 val;
> +
> +	val = readl(hns3_pmu->base + HNS3_PMU_REG_GLOBAL_CTRL);
> +	val |= HNS3_PMU_GLOBAL_START;
> +	writel(val, hns3_pmu->base + HNS3_PMU_REG_GLOBAL_CTRL);
> +}
> +
> +static void hns3_pmu_disable(struct pmu *pmu)
> +{
> +	struct hns3_pmu *hns3_pmu = to_hns3_pmu(pmu);
> +	u32 val;
> +
> +	val = readl(hns3_pmu->base + HNS3_PMU_REG_GLOBAL_CTRL);
> +	val &= ~HNS3_PMU_GLOBAL_START;
> +	writel(val, hns3_pmu->base + HNS3_PMU_REG_GLOBAL_CTRL);
> +}
> +
> +static int hns3_pmu_alloc_pmu(struct pci_dev *pdev, struct hns3_pmu *hns3_pmu)
> +{
> +	u16 device_id;
> +	char *name;
> +	u32 val;
> +	int ret;
> +
> +	hns3_pmu->base = pci_ioremap_bar(pdev, 2);
> +	if (!hns3_pmu->base) {
> +		pci_err(pdev, "ioremap failed for hns3_pmu resource\n");
> +		ret = -ENOMEM;
> +		goto err_ioremap_bar;

Why is there any cleanup to do if we fail here?

> +	}
> +
> +	hns3_pmu->hw_clk_freq = readl(hns3_pmu->base + HNS3_PMU_REG_CLOCK_FREQ);
> +
> +	val = readl(hns3_pmu->base + HNS3_PMU_REG_BDF);
> +	hns3_pmu->bdf_min = val & 0xffff;
> +	hns3_pmu->bdf_max = val >> 16;
> +
> +	val = readl(hns3_pmu->base + HNS3_PMU_REG_DEVICE_ID);
> +	device_id = val & 0xffff;
> +	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "hns3_pmu_%u", device_id);
> +	if (!name) {
> +		pci_err(pdev, "failed to allocate name for HNS3 PMU.\n");
> +		ret = -ENOMEM;
> +		goto err_alloc_dev_name;
> +	}
> +
> +	hns3_pmu->pdev = pdev;
> +	hns3_pmu->on_cpu = HNS3_PMU_INVALID_CPU_ID;
> +	hns3_pmu->identifier = readl(hns3_pmu->base + HNS3_PMU_REG_VERSION);
> +	hns3_pmu->pmu = (struct pmu) {
> +		.name		= name,
> +		.module		= THIS_MODULE,
> +		.event_init	= hns3_pmu_event_init,
> +		.pmu_enable	= hns3_pmu_enable,
> +		.pmu_disable	= hns3_pmu_disable,
> +		.add		= hns3_pmu_add,
> +		.del		= hns3_pmu_del,
> +		.start		= hns3_pmu_start,
> +		.stop		= hns3_pmu_stop,
> +		.read		= hns3_pmu_read,
> +		.task_ctx_nr	= perf_invalid_context,
> +		.attr_groups	= hns3_pmu_attr_groups,
> +		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
> +	};
> +
> +	return 0;
> +
> +err_alloc_dev_name:
> +	iounmap(hns3_pmu->base);
> +err_ioremap_bar:
> +	pci_release_regions(pdev);

Where is matching pci_request_regions?

> +
> +	return ret;
> +}
> +
> +static irqreturn_t hns3_pmu_irq(int irq, void *data)
> +{
> +	struct hns3_pmu *hns3_pmu = data;
> +	u32 intr_status, idx;
> +
> +	for (idx = 0; idx < HNS3_PMU_MAX_COUNTERS; idx++) {
> +		intr_status = hns3_pmu_readl(hns3_pmu,
> +					     HNS3_PMU_REG_EVENT_INTR_STATUS,
> +					     idx);
> +
> +		/*
> +		 * As each counter will restart from 0 when it is overflowed,
> +		 * extra processing is no need, just clear interrupt status.
> +		 */
> +		if (intr_status)
> +			hns3_pmu_clear_intr_status(hns3_pmu, idx);
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int hns3_pmu_online_cpu(unsigned int cpu, struct hlist_node *node)
> +{
> +	struct hns3_pmu *hns3_pmu;
> +
> +	hns3_pmu = hlist_entry_safe(node, struct hns3_pmu, node);
> +	if (!hns3_pmu)
> +		return -ENODEV;
> +
> +	if (hns3_pmu->on_cpu == HNS3_PMU_INVALID_CPU_ID) {
> +		hns3_pmu->on_cpu = cpu;
> +		irq_set_affinity_hint(hns3_pmu->irq, cpumask_of(cpu));
> +	}
> +
> +	return 0;
> +}
> +
> +static int hns3_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
> +{
> +	struct hns3_pmu *hns3_pmu;
> +	unsigned int target;
> +
> +	hns3_pmu = hlist_entry_safe(node, struct hns3_pmu, node);
> +	if (!hns3_pmu)
> +		return -ENODEV;
> +
> +	/* Nothing to do if this CPU doesn't own the PMU */
> +	if (hns3_pmu->on_cpu != cpu)
> +		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(&hns3_pmu->pmu, cpu, target);
> +	hns3_pmu->on_cpu = target;
> +	irq_set_affinity_hint(hns3_pmu->irq, cpumask_of(target));
> +
> +	return 0;
> +}
> +
> +static int hns3_pmu_irq_register(struct pci_dev *pdev,
> +				 struct hns3_pmu *hns3_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, hns3_pmu_irq, 0, hns3_pmu->pmu.name, hns3_pmu);
> +	if (ret) {
> +		pci_err(pdev, "failed to register irq, ret = %d.\n", ret);
> +		pci_free_irq_vectors(pdev);
> +		return ret;
> +	}
> +
> +	hns3_pmu->irq = irq;
> +
> +	return 0;
> +}
> +
> +static void hns3_pmu_irq_unregister(struct pci_dev *pdev,
> +				    struct hns3_pmu *hns3_pmu)
> +{
> +	free_irq(hns3_pmu->irq, hns3_pmu);
> +	pci_free_irq_vectors(pdev);
> +}
> +
> +static int hns3_pmu_init(struct pci_dev *pdev, struct hns3_pmu *hns3_pmu)
> +{
> +	int ret;
> +
> +	ret = hns3_pmu_alloc_pmu(pdev, hns3_pmu);
> +	if (ret)
> +		return ret;
> +
> +	ret = hns3_pmu_irq_register(pdev, hns3_pmu);
> +	if (ret)
> +		goto err_irq_register;
> +
> +	ret = cpuhp_state_add_instance(CPUHP_AP_PERF_ARM_HNS3_PMU_ONLINE,
> +				       &hns3_pmu->node);
> +	if (ret) {
> +		pci_err(pdev, "failed to register hotplug, ret = %d.\n", ret);
> +		goto err_register_hotplug;
> +	}
> +
> +	ret = perf_pmu_register(&hns3_pmu->pmu, hns3_pmu->pmu.name, -1);
> +	if (ret) {
> +		pci_err(pdev, "failed to register HNS3 PMU, ret = %d.\n", ret);
> +		goto err_register_pmu;
> +	}
> +
> +	return ret;
> +
> +err_register_pmu:
> +	cpuhp_state_remove_instance(CPUHP_AP_PERF_ARM_HNS3_PMU_ONLINE,
> +				    &hns3_pmu->node);
> +	irq_set_affinity_hint(hns3_pmu->irq, NULL);
> +
> +err_register_hotplug:
> +	hns3_pmu_irq_unregister(pdev, hns3_pmu);
> +
> +err_irq_register:
> +	iounmap(hns3_pmu->base);
> +
> +	return ret;
> +}
> +
> +static void hns3_pmu_uninit(struct pci_dev *pdev)
> +{
> +	struct hns3_pmu *hns3_pmu = (struct hns3_pmu *)pci_get_drvdata(pdev);

pci_get_drvdata() returns a void * and the c specification allows implicit
casting to any other pointer type.

	struct hns3_pmu *hns3_pmu = pci_get_drvdata(pdev);

> +
> +	perf_pmu_unregister(&hns3_pmu->pmu);
> +	cpuhp_state_remove_instance(CPUHP_AP_PERF_ARM_HNS3_PMU_ONLINE,
> +				    &hns3_pmu->node);
> +	irq_set_affinity_hint(hns3_pmu->irq, NULL);
> +	hns3_pmu_irq_unregister(pdev, hns3_pmu);
> +	iounmap(hns3_pmu->base);
> +}
> +
> +static int hns3_pmu_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, "hns3_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 hns3_pmu_uninit_dev(struct pci_dev *pdev)
> +{
> +	pci_clear_master(pdev);
> +	pci_release_mem_regions(pdev);
> +	pci_disable_device(pdev);
> +}
> +
> +static int hns3_pmu_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> +{
> +	struct hns3_pmu *hns3_pmu;
> +	int ret;
> +
> +	hns3_pmu = devm_kzalloc(&pdev->dev, sizeof(*hns3_pmu), GFP_KERNEL);
> +	if (!hns3_pmu)
> +		return -ENOMEM;
> +
> +	ret = hns3_pmu_init_dev(pdev);
> +	if (ret)
> +		return ret;
> +
> +	ret = hns3_pmu_init(pdev, hns3_pmu);
> +	if (ret) {
> +		hns3_pmu_uninit_dev(pdev);
> +		return ret;
> +	}
> +
> +	pci_set_drvdata(pdev, hns3_pmu);
> +
> +	return ret;
> +}
> +
> +static void hns3_pmu_remove(struct pci_dev *pdev)
> +{
> +	hns3_pmu_uninit(pdev);
> +	hns3_pmu_uninit_dev(pdev);
> +	pci_set_drvdata(pdev, NULL);

Fairly sure that there are not paths in which you need this to be set to
NULL before the driver core will do it anyway.

> +}
> +
> +static const struct pci_device_id hns3_pmu_ids[] = {
> +	{ PCI_DEVICE(PCI_VENDOR_ID_HUAWEI, 0xA22B) },
> +	{ 0, }
> +};
> +MODULE_DEVICE_TABLE(pci, hns3_pmu_ids);
> +
> +static struct pci_driver hns3_pmu_driver = {
> +	.name = "hns3_pmu",
> +	.id_table = hns3_pmu_ids,
> +	.probe = hns3_pmu_probe,
> +	.remove = hns3_pmu_remove,
> +};
> +
> +static int __init hns3_pmu_module_init(void)
> +{
> +	int ret;
> +
> +	ret = hns3_pmu_init_filter_mode_group();
> +	if (ret)
> +		return ret;
> +
> +	ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_HNS3_PMU_ONLINE,
> +				      "AP_PERF_ARM_HNS3_PMU_ONLINE",
> +				      hns3_pmu_online_cpu,
> +				      hns3_pmu_offline_cpu);
> +	if (ret) {
> +		pr_err("failed to setup HNS3 PMU hotplug, ret = %d.\n", ret);
> +		goto err_init;
> +	}
> +
> +	ret = pci_register_driver(&hns3_pmu_driver);
> +	if (ret) {
> +		pr_err("failed to register pci driver, ret = %d.\n", ret);
> +		goto err_hp;
> +	}
> +
> +	return 0;
> +
> +err_hp:
> +	cpuhp_remove_multi_state(CPUHP_AP_PERF_ARM_HNS3_PMU_ONLINE);
> +err_init:
> +	hns3_pmu_uinit_filter_mode_group();
> +	return ret;
> +}
> +module_init(hns3_pmu_module_init);
> +
> +static void __exit hns3_pmu_module_exit(void)
> +{
> +	pci_unregister_driver(&hns3_pmu_driver);
> +	cpuhp_remove_multi_state(CPUHP_AP_PERF_ARM_HNS3_PMU_ONLINE);
> +	hns3_pmu_uinit_filter_mode_group();
> +}
> +module_exit(hns3_pmu_module_exit);
> +
> +MODULE_DESCRIPTION("HNS3 PMU driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
> index 2b73114..2e788f9 100644
> --- a/include/linux/cpuhotplug.h
> +++ b/include/linux/cpuhotplug.h
> @@ -180,6 +180,7 @@ enum cpuhp_state {
>  	CPUHP_AP_PERF_ARM_HISI_PA_ONLINE,
>  	CPUHP_AP_PERF_ARM_HISI_SLLC_ONLINE,
>  	CPUHP_AP_PERF_ARM_HISI_PCIE_PMU_ONLINE,
> +	CPUHP_AP_PERF_ARM_HNS3_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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