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From:   Shuai Xue <xueshuai@linux.alibaba.com>
To:     helgaas@kernel.org, yangyicong@huawei.com, will@kernel.org,
        Jonathan.Cameron@huawei.com
Cc:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-pci@vger.kernel.org, rdunlap@infradead.org,
        robin.murphy@arm.com, mark.rutland@arm.com,
        baolin.wang@linux.alibaba.com, zhuo.song@linux.alibaba.com,
        xueshuai@linux.alibaba.com
Subject: [PATCH v2 2/3] drivers/perf: add DesignWare PCIe PMU driver
Date:   Mon, 10 Apr 2023 11:17:01 +0800
Message-Id: <20230410031702.68355-3-xueshuai@linux.alibaba.com>
In-Reply-To: <20220917121036.14864-1-xueshuai@linux.alibaba.com>
References: <20220917121036.14864-1-xueshuai@linux.alibaba.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

This commit adds the PCIe Performance Monitoring Unit (PMU) driver support
for T-Head Yitian SoC chip. Yitian is based on the Synopsys PCI Express
Core controller IP which provides statistics feature. The PMU is not a PCIe
Root Complex integrated End Point(RCiEP) device but only register counters
provided by each PCIe Root Port.

To facilitate collection of statistics the controller provides the
following two features for each Root Port:

- Time Based Analysis (RX/TX data throughput and time spent in each
  low-power LTSSM state)
- Event counters (Error and Non-Error for lanes)

Note, only one counter for each type and does not overflow interrupt.

This driver adds PMU devices for each PCIe Root Port. And the PMU device is
named based the BDF of Root Port. For example,

    30:03.0 PCI bridge: Device 1ded:8000 (rev 01)

the PMU device name for this Root Port is dwc_rootport_3018.

Example usage of counting PCIe RX TLP data payload (Units of 16 bytes)::

    $# perf stat -a -e dwc_rootport_3018/Rx_PCIe_TLP_Data_Payload/

average RX bandwidth can be calculated like this:

    PCIe TX Bandwidth = PCIE_TX_DATA * 16B / Measure_Time_Window

Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
---
 drivers/perf/Kconfig        |   7 +
 drivers/perf/Makefile       |   1 +
 drivers/perf/dwc_pcie_pmu.c | 877 ++++++++++++++++++++++++++++++++++++
 3 files changed, 885 insertions(+)
 create mode 100644 drivers/perf/dwc_pcie_pmu.c

diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
index 66c259000a44..57bce3880cba 100644
--- a/drivers/perf/Kconfig
+++ b/drivers/perf/Kconfig
@@ -199,6 +199,13 @@ config MARVELL_CN10K_DDR_PMU
 	  Enable perf support for Marvell DDR Performance monitoring
 	  event on CN10K platform.
 
+config DWC_PCIE_PMU
+	tristate "Enable Synopsys DesignWare PCIe PMU Support"
+	depends on ARM64 || (COMPILE_TEST && 64BIT)
+	help
+	  Enable perf support for Synopsys DesignWare PCIe PMU Performance
+	  monitoring event on Yitian 710 platform.
+
 source "drivers/perf/arm_cspmu/Kconfig"
 
 source "drivers/perf/amlogic/Kconfig"
diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile
index 13e45da61100..3f233e96524e 100644
--- a/drivers/perf/Makefile
+++ b/drivers/perf/Makefile
@@ -21,5 +21,6 @@ obj-$(CONFIG_MARVELL_CN10K_TAD_PMU) += marvell_cn10k_tad_pmu.o
 obj-$(CONFIG_MARVELL_CN10K_DDR_PMU) += marvell_cn10k_ddr_pmu.o
 obj-$(CONFIG_APPLE_M1_CPU_PMU) += apple_m1_cpu_pmu.o
 obj-$(CONFIG_ALIBABA_UNCORE_DRW_PMU) += alibaba_uncore_drw_pmu.o
+obj-$(CONFIG_DWC_PCIE_PMU) += dwc_pcie_pmu.o
 obj-$(CONFIG_ARM_CORESIGHT_PMU_ARCH_SYSTEM_PMU) += arm_cspmu/
 obj-$(CONFIG_MESON_DDR_PMU) += amlogic/
diff --git a/drivers/perf/dwc_pcie_pmu.c b/drivers/perf/dwc_pcie_pmu.c
new file mode 100644
index 000000000000..c8c09f120d4e
--- /dev/null
+++ b/drivers/perf/dwc_pcie_pmu.c
@@ -0,0 +1,877 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Synopsys DesignWare PCIe PMU driver
+ *
+ * Copyright (C) 2021, 2022 Alibaba Inc.
+ */
+
+#include <linux/pci.h>
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/cpuhotplug.h>
+#include <linux/cpumask.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/smp.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+#define PCI_VENDOR_ID_ALIBABA 0x1ded
+
+#define ATTRI_NAME_MAX_SIZE			32
+#define DWC_PCIE_VSEC_RAS_DES_ID		0x02
+
+#define DWC_PCIE_EVENT_CNT_CTL			0x8
+#define DWC_PCIE_CNT_EVENT_SEL			GENMASK(27, 16)
+#define DWC_PCIE_CNT_LANE_SEL			GENMASK(11, 8)
+#define DWC_PCIE_CNT_STATUS			BIT(7)
+#define DWC_PCIE_CNT_ENABLE			GENMASK(4, 2)
+#define DWC_PCIE_PER_EVENT_OFF			FIELD_PREP(DWC_PCIE_CNT_ENABLE, 0x1)
+#define DWC_PCIE_PER_EVENT_ON			FIELD_PREP(DWC_PCIE_CNT_ENABLE, 0x3)
+#define DWC_PCIE_EVENT_CLEAR			GENMASK(1, 0)
+#define DWC_PCIE_EVENT_PER_CLEAR		0x1
+
+#define DWC_PCIE_EVENT_CNT_DATA			0xC
+
+#define DWC_PCIE_TIME_BASED_ANAL_CTL		0x10
+#define DWC_PCIE_TIME_BASED_REPORT_SEL		GENMASK(31, 24)
+#define DWC_PCIE_TIME_BASED_DURATION_SEL	GENMASK(15, 8)
+#define DWC_PCIE_DURATION_MANUAL_CTL		0x0
+#define DWC_PCIE_DURATION_1MS			0x1
+#define DWC_PCIE_DURATION_10MS			0x2
+#define DWC_PCIE_DURATION_100MS			0x3
+#define DWC_PCIE_DURATION_1S			0x4
+#define DWC_PCIE_DURATION_2S			0x5
+#define DWC_PCIE_DURATION_4S			0x6
+#define DWC_PCIE_DURATION_4US			0xff
+#define DWC_PCIE_TIME_BASED_CNT_ENABLE		0x1
+
+#define DWC_PCIE_TIME_BASED_ANAL_DATA_REG_LOW	0x14
+#define DWC_PCIE_TIME_BASED_ANAL_DATA_REG_HIGH	0x18
+
+/* Event attributes */
+#define DWC_PCIE_CONFIG_EVENTID			GENMASK(15, 0)
+#define DWC_PCIE_CONFIG_TYPE			GENMASK(19, 16)
+#define DWC_PCIE_CONFIG_LANE			GENMASK(27, 20)
+
+#define DWC_PCIE_EVENT_ID(event)	FIELD_GET(DWC_PCIE_CONFIG_EVENTID, (event)->attr.config)
+#define DWC_PCIE_EVENT_TYPE(event)	FIELD_GET(DWC_PCIE_CONFIG_TYPE, (event)->attr.config)
+#define DWC_PCIE_EVENT_LANE(event)	FIELD_GET(DWC_PCIE_CONFIG_LANE, (event)->attr.config)
+
+#define DWC_PCIE_PMU_HAS_REGISTER		1
+
+enum dwc_pcie_event_type {
+	DWC_PCIE_TYPE_INVALID,
+	DWC_PCIE_TIME_BASE_EVENT,
+	DWC_PCIE_LANE_EVENT,
+};
+
+struct dwc_event_counters {
+	const char name[32];
+	u32 event_id;
+};
+
+struct dwc_pcie_pmu {
+	struct hlist_node node;
+	unsigned int on_cpu;
+	struct pmu pmu;
+	struct device *dev;
+};
+
+struct dwc_pcie_rp_info {
+	u32 bdf;
+	u32 ras_des;
+	u32 num_lanes;
+
+	struct list_head rp_node;
+	struct pci_dev *pdev;
+	struct dwc_pcie_pmu pcie_pmu;
+	u8 pmu_is_register;
+	struct perf_event *event;
+
+	struct dwc_pcie_event_attr *lane_event_attrs;
+	struct attribute **pcie_pmu_event_attrs;
+	struct attribute_group pcie_pmu_event_attrs_group;
+	const struct attribute_group *pcie_pmu_attr_groups[4];
+};
+
+struct dwc_pcie_pmu_priv {
+	struct device *dev;
+	u32 pcie_ctrl_num;
+	struct list_head rp_infos;
+};
+
+#define to_dwc_pcie_pmu(p) (container_of(p, struct dwc_pcie_pmu, pmu))
+
+static struct platform_device *dwc_pcie_pmu_dev;
+static char *event_attr_name = "events";
+
+static ssize_t cpumask_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct dwc_pcie_pmu *pcie_pmu = to_dwc_pcie_pmu(dev_get_drvdata(dev));
+
+	return cpumap_print_to_pagebuf(true, buf, cpumask_of(pcie_pmu->on_cpu));
+}
+static DEVICE_ATTR_RO(cpumask);
+
+#define DEVICE_ATTR_RO(_name) \
+	struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
+#define __ATTR_RO(_name) {						\
+	.attr	= { .name = __stringify(_name), .mode = 0444 },		\
+	.show	= _name##_show,						\
+}
+#define __ATTR(_name, _mode, _show, _store) {				\
+	.attr = {.name = __stringify(_name),				\
+		 .mode = VERIFY_OCTAL_PERMISSIONS(_mode) },		\
+	.show	= _show,						\
+	.store	= _store,						\
+}
+
+static struct attribute *dwc_pcie_pmu_cpumask_attrs[] = {
+	&dev_attr_cpumask.attr,
+	NULL
+};
+
+static struct attribute_group pcie_pmu_cpumask_attrs_group = {
+	.attrs = dwc_pcie_pmu_cpumask_attrs,
+};
+
+struct dwc_pcie_format_attr {
+	struct device_attribute attr;
+	u64 field;
+	int config;
+};
+
+static ssize_t dwc_pcie_pmu_format_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct dwc_pcie_format_attr *fmt = container_of(attr, typeof(*fmt), attr);
+	int lo = __ffs(fmt->field), hi = __fls(fmt->field);
+
+	if (lo == hi)
+		return snprintf(buf, PAGE_SIZE, "config:%d\n", lo);
+
+	if (!fmt->config)
+		return snprintf(buf, PAGE_SIZE, "config:%d-%d\n", lo, hi);
+
+	return snprintf(buf, PAGE_SIZE, "config%d:%d-%d\n", fmt->config, lo,
+			hi);
+}
+
+#define _dwc_pcie_format_attr(_name, _cfg, _fld)				\
+	(&((struct dwc_pcie_format_attr[]) {{				\
+		.attr = __ATTR(_name, 0444, dwc_pcie_pmu_format_show, NULL),	\
+		.config = _cfg,						\
+		.field = _fld,						\
+	}})[0].attr.attr)
+
+#define dwc_pcie_format_attr(_name, _fld)	_dwc_pcie_format_attr(_name, 0, _fld)
+
+static struct attribute *dwc_pcie_format_attrs[] = {
+	dwc_pcie_format_attr(type, DWC_PCIE_CONFIG_TYPE),
+	dwc_pcie_format_attr(eventid, DWC_PCIE_CONFIG_EVENTID),
+	dwc_pcie_format_attr(lane, DWC_PCIE_CONFIG_LANE),
+	NULL,
+};
+
+static struct attribute_group pcie_pmu_format_attrs_group = {
+	.name = "format",
+	.attrs = dwc_pcie_format_attrs,
+};
+
+struct dwc_pcie_event_attr {
+	struct device_attribute attr;
+	enum dwc_pcie_event_type type;
+	u16 eventid;
+	u8 lane;
+};
+
+ssize_t dwc_pcie_event_show(struct device *dev,
+				struct device_attribute *attr, char *page)
+{
+	struct dwc_pcie_event_attr *eattr;
+
+	eattr = container_of(attr, typeof(*eattr), attr);
+
+	if (eattr->type == DWC_PCIE_LANE_EVENT)
+		return sprintf(page, "eventid=0x%lx, type=0x%lx, lane=0x%lx\n",
+			       (unsigned long)eattr->eventid,
+			       (unsigned long)eattr->type,
+			       (unsigned long)eattr->lane);
+	else
+		return sprintf(page, "eventid=0x%lx, type=0x%lx",
+			       (unsigned long)eattr->eventid,
+			       (unsigned long)eattr->type);
+}
+
+#define DWC_PCIE_EVENT_ATTR(_name, _type, _eventid, _lane)		\
+	(&((struct dwc_pcie_event_attr[]) {{				\
+		.attr = __ATTR(_name, 0444, dwc_pcie_event_show, NULL),	\
+		.type = _type,						\
+		.eventid = _eventid,					\
+		.lane = _lane,					\
+	}})[0].attr.attr)
+
+#define DWC_PCIE_PMU_BASE_TIME_ATTR(_name, _eventid)			\
+	DWC_PCIE_EVENT_ATTR(_name, DWC_PCIE_TIME_BASE_EVENT, _eventid, 0)
+
+static struct attribute *dwc_pcie_pmu_time_event_attrs[] = {
+	/* Group #0 */
+	DWC_PCIE_PMU_BASE_TIME_ATTR(one_cycle, 0x00),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(TX_L0S, 0x01),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(RX_L0S, 0x02),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(L0, 0x03),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(L1, 0x04),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(L1_1, 0x05),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(L1_2, 0x06),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(CFG_RCVRY, 0x07),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(TX_RX_L0S, 0x08),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(L1_AUX, 0x09),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(ONE_cycle, 0x10),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(TX_L0S_, 0x11),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(RX_L0S_, 0x12),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(L0_, 0x13),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(L1_, 0x17),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(CFG_RCVRY_, 0x17),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(TX_RX_L0S_, 0x18),
+	/* Group #1 */
+	DWC_PCIE_PMU_BASE_TIME_ATTR(Tx_PCIe_TLP_Data_Payload, 0x20),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(Rx_PCIe_TLP_Data_Payload, 0x21),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(Tx_CCIX_TLP_Data_Payload, 0x22),
+	DWC_PCIE_PMU_BASE_TIME_ATTR(Rx_CCIX_TLP_Data_Payload, 0x23),
+	NULL
+};
+
+static inline umode_t pcie_pmu_event_attr_is_visible(struct kobject *kobj,
+						     struct attribute *attr,
+						     int unuse)
+{
+	return attr->mode;
+}
+
+static inline bool pci_dev_is_rootport(struct pci_dev *pdev)
+{
+	return (pci_is_pcie(pdev) &&
+		pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT);
+}
+
+static int dwc_pcie_ras_des_discover(struct dwc_pcie_pmu_priv *priv)
+{
+	int index = 0;
+	struct pci_dev *pdev = NULL;
+	struct dwc_pcie_rp_info *rp_info;
+
+	INIT_LIST_HEAD(&priv->rp_infos);
+
+	/* Match the rootport with VSEC_RAS_DES_ID */
+	for_each_pci_dev(pdev) {
+		u16 vsec;
+		u32 val;
+
+		if (!pci_dev_is_rootport(pdev))
+			continue;
+
+		rp_info = devm_kzalloc(&pdev->dev, sizeof(*rp_info), GFP_KERNEL);
+		if (!rp_info)
+			return -ENOMEM;
+
+		rp_info->bdf = PCI_DEVID(pdev->bus->number, pdev->devfn);
+		rp_info->pdev = pdev;
+
+		vsec = pci_find_vsec_capability(pdev, PCI_VENDOR_ID_ALIBABA,
+						DWC_PCIE_VSEC_RAS_DES_ID);
+		if (!vsec)
+			continue;
+
+		pci_read_config_dword(pdev, vsec + PCI_VNDR_HEADER, &val);
+		if (PCI_VNDR_HEADER_REV(val) != 0x04 ||
+		    PCI_VNDR_HEADER_LEN(val) != 0x100)
+			continue;
+		pci_dbg(pdev,
+			"Detected PCIe Vendor-Specific Extended Capability RAS DES\n");
+
+		rp_info->ras_des = vsec;
+
+		pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &val);
+		rp_info->num_lanes = pcie_get_width_cap(pdev);
+
+		list_add(&rp_info->rp_node, &priv->rp_infos);
+		index++;
+	}
+
+	if (!index)
+		return -ENODEV;
+
+	priv->pcie_ctrl_num = index;
+
+	return 0;
+}
+
+static void dwc_pcie_pmu_set_event_id(struct pci_dev *pdev, u16 ras_des,
+				     int event_id)
+{
+	u32 val;
+
+	pci_read_config_dword(pdev, ras_des + DWC_PCIE_EVENT_CNT_CTL, &val);
+
+	val &= ~DWC_PCIE_CNT_ENABLE;
+	val |= FIELD_PREP(DWC_PCIE_CNT_EVENT_SEL, event_id);
+
+	pci_write_config_dword(pdev, ras_des + DWC_PCIE_EVENT_CNT_CTL, val);
+}
+
+static void dwc_pcie_pmu_write_event_lane(struct pci_dev *pdev, u16 ras_des,
+					 int lane, int event_id)
+{
+	u32 val;
+
+	pci_read_config_dword(pdev, ras_des + DWC_PCIE_EVENT_CNT_CTL, &val);
+
+	val &= ~DWC_PCIE_CNT_LANE_SEL;
+	val |= FIELD_PREP(DWC_PCIE_CNT_EVENT_SEL, lane);
+
+	pci_write_config_dword(pdev, ras_des + DWC_PCIE_EVENT_CNT_CTL, val);
+}
+
+static void dwc_pcie_pmu_event_enable(struct pci_dev *pdev, u16 ras_des,
+				     u32 enable)
+{
+	u32 val;
+
+	pci_read_config_dword(pdev, ras_des + DWC_PCIE_EVENT_CNT_CTL, &val);
+
+	val &= ~DWC_PCIE_CNT_ENABLE;
+
+	if (enable)
+		val |= DWC_PCIE_PER_EVENT_ON;
+	else
+		val |= DWC_PCIE_PER_EVENT_OFF;
+
+	pci_write_config_dword(pdev, ras_des + DWC_PCIE_EVENT_CNT_CTL, val);
+}
+
+static void dwc_pcie_pmu_base_time_enable(struct pci_dev *pdev, u16 ras_des,
+					 u32 enable)
+{
+	u32 val;
+
+	pci_read_config_dword(pdev, ras_des + DWC_PCIE_TIME_BASED_ANAL_CTL, &val);
+
+	if (enable)
+		val |= DWC_PCIE_TIME_BASED_CNT_ENABLE;
+	else
+		val &= ~DWC_PCIE_TIME_BASED_CNT_ENABLE;
+
+	pci_write_config_dword(pdev, ras_des + DWC_PCIE_TIME_BASED_ANAL_CTL, val);
+}
+
+static void dwc_pcie_pmu_read_event_counter(struct pci_dev *pdev, u16 ras_des,
+					    u64 *counter)
+{
+	u32 val;
+
+	pci_read_config_dword(pdev, ras_des + DWC_PCIE_EVENT_CNT_DATA, &val);
+	*counter = val;
+}
+
+/* The results are cleared when next measurement starts. */
+static void dwc_pcie_pmu_read_base_time_counter(struct pci_dev *pdev,
+						u16 ras_des, u64 *counter)
+{
+	u32 val;
+
+	pci_read_config_dword(
+		pdev, ras_des + DWC_PCIE_TIME_BASED_ANAL_DATA_REG_HIGH,
+		&val);
+	*counter = val;
+	*counter <<= 32;
+
+	pci_read_config_dword(
+		pdev, ras_des + DWC_PCIE_TIME_BASED_ANAL_DATA_REG_LOW,
+		&val);
+
+	*counter += val;
+}
+
+static void dwc_pcie_pmu_clear_event_counter(struct pci_dev *pdev, u16 ras_des)
+{
+	u32 val;
+
+	pci_read_config_dword(pdev, ras_des + DWC_PCIE_EVENT_CNT_CTL, &val);
+
+	val |= FIELD_PREP(DWC_PCIE_EVENT_CLEAR, DWC_PCIE_EVENT_PER_CLEAR);
+
+	pci_write_config_dword(pdev, ras_des + DWC_PCIE_EVENT_CNT_CTL, val);
+}
+
+static void dwc_pcie_pmu_base_time_add_prepare(struct pci_dev *pdev,
+					       u16 ras_des, u32 event_id)
+{
+	u32 val;
+
+	pci_read_config_dword(pdev, ras_des + DWC_PCIE_TIME_BASED_ANAL_CTL,
+			      &val);
+
+	val &= ~DWC_PCIE_TIME_BASED_REPORT_SEL;
+	val |= FIELD_PREP(DWC_PCIE_TIME_BASED_REPORT_SEL, event_id);
+	val &= ~DWC_PCIE_TIME_BASED_DURATION_SEL;
+
+	/*
+	 * TIME_BASED_ANAL_DATA_REG is a 64 bit register, we can safely
+	 * use it with any manually controlled duration.
+	 */
+	val &= ~(DWC_PCIE_TIME_BASED_DURATION_SEL);
+	val |= DWC_PCIE_DURATION_MANUAL_CTL;
+
+	pci_write_config_dword(pdev, ras_des + DWC_PCIE_TIME_BASED_ANAL_CTL,
+			       val);
+}
+
+static struct dwc_pcie_rp_info *pmu_to_pcie_info(struct pmu *pmu)
+{
+	struct dwc_pcie_rp_info *rp_info;
+	struct dwc_pcie_pmu *pcie_pmu = to_dwc_pcie_pmu(pmu);
+
+	rp_info = container_of(pcie_pmu, struct dwc_pcie_rp_info, pcie_pmu);
+
+	return rp_info;
+}
+
+static void dwc_pcie_pmu_event_update(struct perf_event *event)
+{
+	u64 counter;
+	struct dwc_pcie_pmu *pcie_pmu = to_dwc_pcie_pmu(event->pmu);
+	struct dwc_pcie_rp_info *rp_info = pmu_to_pcie_info(event->pmu);
+	struct pci_dev *pdev = rp_info->pdev;
+	u16 ras_des = rp_info->ras_des;
+	struct hw_perf_event *hwc = &event->hw;
+	enum dwc_pcie_event_type type = DWC_PCIE_EVENT_TYPE(event);
+	u64 delta, prev, now;
+
+	do {
+		prev = local64_read(&hwc->prev_count);
+
+		if (type == DWC_PCIE_LANE_EVENT)
+			dwc_pcie_pmu_read_event_counter(pdev, ras_des, &counter);
+		else if (type == DWC_PCIE_TIME_BASE_EVENT)
+			dwc_pcie_pmu_read_base_time_counter(pdev, ras_des,
+							    &counter);
+		else
+			dev_err(pcie_pmu->dev, "invalid event type: 0x%x\n", type);
+
+		now = counter;
+	} while (local64_cmpxchg(&hwc->prev_count, prev, now) != prev);
+
+	delta = now - prev;
+
+	local64_add(delta, &event->count);
+}
+
+static int dwc_pcie_pmu_event_init(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	struct dwc_pcie_pmu *pcie_pmu = to_dwc_pcie_pmu(event->pmu);
+	struct perf_event *sibling;
+
+	if (event->attr.type != event->pmu->type)
+		return -ENOENT;
+
+	if (hwc->sample_period) {
+		dev_dbg(pcie_pmu->dev, "Sampling not supported\n");
+		return -EOPNOTSUPP;
+	}
+
+	if (event->cpu < 0) {
+		dev_dbg(pcie_pmu->dev, "Per-task mode not supported\n");
+		return -EOPNOTSUPP;
+	}
+
+	event->cpu = pcie_pmu->on_cpu;
+
+	if (event->group_leader != event &&
+	    !is_software_event(event->group_leader))
+		return -EINVAL;
+
+	for_each_sibling_event(sibling, event->group_leader) {
+		if (sibling != event && !is_software_event(sibling))
+			return -EINVAL;
+	}
+
+	hwc->idx = -1;
+
+	return 0;
+}
+
+static void dwc_pcie_pmu_set_period(struct hw_perf_event *hwc)
+{
+	local64_set(&hwc->prev_count, 0);
+}
+
+static void dwc_pcie_pmu_event_start(struct perf_event *event, int flags)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	struct dwc_pcie_pmu *pcie_pmu = to_dwc_pcie_pmu(event->pmu);
+	struct dwc_pcie_rp_info *rp_info = pmu_to_pcie_info(event->pmu);
+	struct pci_dev *pdev = rp_info->pdev;
+	u16 ras_des = rp_info->ras_des;
+	enum dwc_pcie_event_type type = DWC_PCIE_EVENT_TYPE(event);
+
+	hwc->state = 0;
+	dwc_pcie_pmu_set_period(hwc);
+
+	if (type == DWC_PCIE_LANE_EVENT)
+		dwc_pcie_pmu_event_enable(pdev, ras_des, 1);
+	else if (type == DWC_PCIE_TIME_BASE_EVENT)
+		dwc_pcie_pmu_base_time_enable(pdev, ras_des, 1);
+	else
+		dev_err(pcie_pmu->dev, "invalid event type: 0x%x\n", type);
+}
+
+static void dwc_pcie_pmu_event_stop(struct perf_event *event, int flags)
+{
+	struct dwc_pcie_pmu *pcie_pmu = to_dwc_pcie_pmu(event->pmu);
+	struct dwc_pcie_rp_info *rp_info = pmu_to_pcie_info(event->pmu);
+	struct pci_dev *pdev = rp_info->pdev;
+	u16 ras_des = rp_info->ras_des;
+
+	enum dwc_pcie_event_type type = DWC_PCIE_EVENT_TYPE(event);
+
+	if (event->hw.state & PERF_HES_STOPPED)
+		return;
+
+	if (type == DWC_PCIE_LANE_EVENT)
+		dwc_pcie_pmu_event_enable(pdev, ras_des, 0);
+	else if (type == DWC_PCIE_TIME_BASE_EVENT)
+		dwc_pcie_pmu_base_time_enable(pdev, ras_des, 0);
+	else
+		dev_err(pcie_pmu->dev, "invalid event type: 0x%x\n", type);
+
+	dwc_pcie_pmu_event_update(event);
+}
+
+static int dwc_pcie_pmu_event_add(struct perf_event *event, int flags)
+{
+	struct dwc_pcie_pmu *pcie_pmu = to_dwc_pcie_pmu(event->pmu);
+	struct dwc_pcie_rp_info *rp_info = pmu_to_pcie_info(event->pmu);
+	struct pci_dev *pdev = rp_info->pdev;
+	u16 ras_des = rp_info->ras_des;
+	struct hw_perf_event *hwc = &event->hw;
+	enum dwc_pcie_event_type type = DWC_PCIE_EVENT_TYPE(event);
+	int event_id = DWC_PCIE_EVENT_ID(event);
+	int lane = DWC_PCIE_EVENT_LANE(event);
+
+	/* Only one counter and it is in use */
+	if (rp_info->event)
+		return -ENOSPC;
+
+	rp_info->event = event;
+
+	hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+
+	if (type == DWC_PCIE_LANE_EVENT) {
+		dwc_pcie_pmu_event_enable(pdev, ras_des, 0);
+		dwc_pcie_pmu_write_event_lane(pdev, ras_des, lane, event_id);
+		dwc_pcie_pmu_set_event_id(pdev, ras_des, event_id);
+		dwc_pcie_pmu_clear_event_counter(pdev, ras_des);
+	} else if (type == DWC_PCIE_TIME_BASE_EVENT) {
+		dwc_pcie_pmu_base_time_enable(pdev, ras_des, 0);
+		dwc_pcie_pmu_base_time_add_prepare(pdev, ras_des, event_id);
+	} else {
+		dev_err(pcie_pmu->dev, "invalid event type: 0x%x\n", type);
+		return -EINVAL;
+	}
+
+	if (flags & PERF_EF_START)
+		dwc_pcie_pmu_event_start(event, PERF_EF_RELOAD);
+
+	perf_event_update_userpage(event);
+
+	return 0;
+}
+
+static void dwc_pcie_pmu_event_del(struct perf_event *event, int flags)
+{
+	struct dwc_pcie_rp_info *rp_info = pmu_to_pcie_info(event->pmu);
+
+	dwc_pcie_pmu_event_stop(event, flags | PERF_EF_UPDATE);
+	perf_event_update_userpage(event);
+	rp_info->event = NULL;
+}
+
+static void dwc_pcie_pmu_event_read(struct perf_event *event)
+{
+	dwc_pcie_pmu_event_update(event);
+}
+
+static struct dwc_event_counters event_array[] = {
+	{"tx_ack_dllp", 0x600},
+	{"tx_update_fc_dllp", 0x601},
+	{"rx_ack_dllp", 0x602},
+	{"rx_update_fc_dllp", 0x603},
+	{"rx_nulified_tlp", 0x604},
+	{"tx_nulified_tlp", 0x605},
+	{"rx_duplicate_tlp", 0x606},
+	{"tx_memory_write", 0x700},
+	{"tx_memory_read", 0x701},
+	{"tx_configuration_write", 0x702},
+	{"tx_configuration_read", 0x703},
+	{"tx_io_write", 0x704},
+	{"tx_io_read", 0x705},
+	{"tx_completion_without_data", 0x706},
+	{"tx_completion_with_data", 0x707},
+	{"tx_message_tlp", 0x708},
+	{"tx_atomic", 0x709},
+	{"tx_tlp_with_prefix", 0x70A},
+	{"rx_memory_write", 0x70B},
+	{"rx_memory_read", 0x70C},
+	{"rx_io_write", 0x70F},
+	{"rx_io_read", 0x710},
+	{"rx_completion_without_data", 0x711},
+	{"rx_completion_with_data", 0x712},
+	{"rx_message_tlp", 0x713},
+	{"rx_atomic", 0x714},
+	{"rx_tlp_with_prefix", 0x715},
+	{"tx_ccix_tlp", 0x716},
+	{"rx_ccix_tlp", 0x717},
+};
+
+static int dwc_pcie_pmu_attr_init(struct dwc_pcie_pmu_priv *priv,
+				  struct dwc_pcie_rp_info *rp_info)
+{
+	int i, j;
+	char lane[8];
+	const char tmp[64];
+	int events_per_lane;
+	int num_lane_events;
+	int time_base_count;
+	int num_attrs, attr_idx;
+	struct dwc_pcie_event_attr *lane_attrs;
+	struct attribute **pmu_attrs;
+
+	memset((void *)tmp, 0, sizeof(tmp));
+	memset((void *)lane, 0, sizeof(lane));
+	time_base_count = ARRAY_SIZE(dwc_pcie_pmu_time_event_attrs);
+	events_per_lane = ARRAY_SIZE(event_array);
+	num_lane_events = rp_info->num_lanes * events_per_lane;
+	num_attrs = time_base_count + num_lane_events;
+
+	rp_info->lane_event_attrs =
+		devm_kcalloc(priv->dev, num_lane_events,
+				sizeof(struct dwc_pcie_event_attr),
+				GFP_KERNEL);
+	if (!rp_info->lane_event_attrs)
+		return -ENOMEM;
+	lane_attrs = rp_info->lane_event_attrs;
+	rp_info->pcie_pmu_event_attrs =
+		devm_kcalloc(priv->dev, num_attrs, sizeof(struct attribute *),
+			 GFP_KERNEL);
+	if (!rp_info->pcie_pmu_event_attrs)
+		return -ENOMEM;
+	pmu_attrs = rp_info->pcie_pmu_event_attrs;
+
+	for (i = 0; i < num_lane_events; i++) {
+		lane_attrs[i].attr.attr.name =
+		    devm_kzalloc(priv->dev, sizeof(char)
+				 * ATTRI_NAME_MAX_SIZE, GFP_KERNEL);
+		if (!lane_attrs[i].attr.attr.name)
+			return -ENOMEM;
+	}
+
+	attr_idx = 0;
+	for (i = 0; i < rp_info->num_lanes; i++) {
+		sprintf(lane, "_lane%d", i);
+
+		for (j = 0; j < events_per_lane; j++) {
+			int pos = i * events_per_lane + j;
+
+			strcat((char *)tmp, event_array[j].name);
+			strcat((char *)tmp, lane);
+			memcpy((void *)lane_attrs[pos].attr.attr.name,
+			       (void *)tmp,
+			       sizeof(tmp));
+
+			lane_attrs[pos].attr.attr.mode =
+			    VERIFY_OCTAL_PERMISSIONS(0444);
+			lane_attrs[pos].attr.show = dwc_pcie_event_show;
+			lane_attrs[pos].attr.store = NULL;
+			lane_attrs[pos].type = DWC_PCIE_LANE_EVENT;
+			lane_attrs[pos].eventid = event_array[j].event_id;
+			lane_attrs[pos].lane = i;
+			pmu_attrs[attr_idx++] = &lane_attrs[pos].attr.attr;
+
+			memset((void *)tmp, 0, sizeof(tmp));
+		}
+	}
+
+	for (i = 0; i < ARRAY_SIZE(dwc_pcie_pmu_time_event_attrs); i++)
+		pmu_attrs[attr_idx++] = dwc_pcie_pmu_time_event_attrs[i];
+
+	rp_info->pcie_pmu_event_attrs[attr_idx++] = NULL;
+
+	rp_info->pcie_pmu_event_attrs_group.name = event_attr_name;
+	rp_info->pcie_pmu_event_attrs_group.is_visible =
+	    pcie_pmu_event_attr_is_visible;
+	rp_info->pcie_pmu_event_attrs_group.attrs =
+	    rp_info->pcie_pmu_event_attrs;
+
+	rp_info->pcie_pmu_attr_groups[0] =
+	    &rp_info->pcie_pmu_event_attrs_group;
+	rp_info->pcie_pmu_attr_groups[1] = &pcie_pmu_format_attrs_group;
+	rp_info->pcie_pmu_attr_groups[2] = &pcie_pmu_cpumask_attrs_group;
+	rp_info->pcie_pmu_attr_groups[3] = NULL;
+
+	return 0;
+}
+
+static int __dwc_pcie_pmu_probe(struct dwc_pcie_pmu_priv *priv,
+				struct dwc_pcie_rp_info *rp_info)
+{
+	struct dwc_pcie_pmu *pcie_pmu;
+	struct device *dev;
+	char *name;
+	int ret;
+
+	pcie_pmu = &rp_info->pcie_pmu;
+	dev = &rp_info->pdev->dev;
+
+	ret = dwc_pcie_pmu_attr_init(priv, rp_info);
+	if (ret) {
+		pci_err(rp_info->pdev, "PMU attr init fail ret=%d\n", ret);
+		return ret;
+	}
+
+	pcie_pmu->dev = dev;
+	pcie_pmu->pmu = (struct pmu) {
+		.module		= THIS_MODULE,
+		.task_ctx_nr	= perf_invalid_context,
+		.pmu_enable	= NULL,
+		.pmu_disable	= NULL,
+		.event_init	= dwc_pcie_pmu_event_init,
+		.add		= dwc_pcie_pmu_event_add,
+		.del		= dwc_pcie_pmu_event_del,
+		.start		= dwc_pcie_pmu_event_start,
+		.stop		= dwc_pcie_pmu_event_stop,
+		.read		= dwc_pcie_pmu_event_read,
+		.attr_groups	= rp_info->pcie_pmu_attr_groups,
+		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
+	};
+
+	name = devm_kasprintf(priv->dev, GFP_KERNEL, "dwc_rootport_%x",
+			      rp_info->bdf);
+	if (!name)
+		return -ENOMEM;
+
+	/*
+	 * Pick one CPU to be the preferred one on local NUMA node.
+	 *
+	 * Note, this PMU does NOT support interrupt, set on_cpu to indicate it
+	 * is a uncore PMU device.
+	 */
+	pcie_pmu->on_cpu = cpumask_local_spread(0, dev_to_node(pcie_pmu->dev));
+	ret = perf_pmu_register(&pcie_pmu->pmu, name, -1);
+	if (ret) {
+		pci_err(rp_info->pdev, "Error %d registering PMU @%x\n", ret,
+				 rp_info->bdf);
+		return ret;
+	}
+
+	rp_info->pmu_is_register = DWC_PCIE_PMU_HAS_REGISTER;
+
+	return ret;
+}
+
+static int dwc_pcie_pmu_remove(struct platform_device *pdev)
+{
+	struct dwc_pcie_pmu_priv *priv = platform_get_drvdata(pdev);
+	struct dwc_pcie_pmu *pcie_pmu;
+	struct dwc_pcie_rp_info *rp_info;
+
+	list_for_each_entry(rp_info, &priv->rp_infos, rp_node) {
+		if (rp_info->pmu_is_register) {
+			pcie_pmu = &rp_info->pcie_pmu;
+			perf_pmu_unregister(&pcie_pmu->pmu);
+		}
+	}
+	return 0;
+}
+
+static int dwc_pcie_pmu_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct dwc_pcie_pmu_priv *priv;
+	struct dwc_pcie_rp_info *rp_info;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = &pdev->dev;
+	platform_set_drvdata(pdev, priv);
+
+	/* If RAS_DES PMU is not supported on current platform, keep silent */
+	ret = dwc_pcie_ras_des_discover(priv);
+	if (ret)
+		return ret;
+
+	list_for_each_entry(rp_info, &priv->rp_infos, rp_node) {
+		struct pci_dev *rp = rp_info->pdev;
+
+		ret = __dwc_pcie_pmu_probe(priv, rp_info);
+		if (ret) {
+			dev_err(&rp->dev, "PCIe PMU probe fail\n");
+			goto pmu_unregister;
+		}
+	}
+
+	return 0;
+
+pmu_unregister:
+	dwc_pcie_pmu_remove(pdev);
+
+	return ret;
+}
+
+static struct platform_driver dwc_pcie_pmu_driver = {
+	.probe = dwc_pcie_pmu_probe,
+	.remove = dwc_pcie_pmu_remove,
+	.driver = {.name = "dwc_pcie_pmu",},
+};
+
+static int __init dwc_pcie_pmu_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&dwc_pcie_pmu_driver);
+
+	if (ret)
+		return ret;
+
+	dwc_pcie_pmu_dev =
+	    platform_device_register_simple("dwc_pcie_pmu", -1, NULL, 0);
+	if (IS_ERR(dwc_pcie_pmu_dev)) {
+		platform_driver_unregister(&dwc_pcie_pmu_driver);
+		return PTR_ERR(dwc_pcie_pmu_dev);
+	}
+
+	return 0;
+}
+
+static void __exit dwc_pcie_pmu_exit(void)
+{
+	platform_device_unregister(dwc_pcie_pmu_dev);
+	platform_driver_unregister(&dwc_pcie_pmu_driver);
+}
+
+module_init(dwc_pcie_pmu_init);
+module_exit(dwc_pcie_pmu_exit);
+
+MODULE_DESCRIPTION("PMU driver for DesignWare Cores PCI Express Controller");
+MODULE_AUTHOR("xueshuai@linux.alibaba.com");
+MODULE_AUTHOR("yinxuan_cw@linux.alibaba.com");
+MODULE_LICENSE("GPL v2");
-- 
2.20.1.12.g72788fdb