drivers/perf: add DDR Sub-System Driveway PMU driver for Yitian 710 SoC

Add the DDR Sub-System Driveway Performance Monitoring Unit (PMU) driver
support for Alibaba T-Head Yitian 710 SoC chip. Yitian supports DDR5/4
DRAM and targets cloud computing and HPC.

Each PMU is registered as a device in /sys/bus/event_source/devices, and
users can select event to monitor in each sub-channel, independently. For
example, ali_drw_21000 and ali_drw_21080 are two PMU devices for two
sub-channels of the same channel in die 0. And the PMU device of die 1 is
prefixed with ali_drw_400XXXXX, e.g. ali_drw_40021000.

Due to hardware limitation, one of DDRSS Driveway PMU overflow interrupt
shares the same irq number with MPAM ERR_IRQ. To register DDRSS PMU and
MPAM drivers successfully, add IRQF_SHARED flag.

Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Co-developed-by: Hongbo Yao <yaohongbo@linux.alibaba.com>
Signed-off-by: Hongbo Yao <yaohongbo@linux.alibaba.com>
Co-developed-by: Neng Chen <nengchen@linux.alibaba.com>
Signed-off-by: Neng Chen <nengchen@linux.alibaba.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220818031822.38415-3-xueshuai@linux.alibaba.com
Signed-off-by: Will Deacon <will@kernel.org>

3 files changed, 818 insertions, 0 deletions

diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
index 1e2d69453771..44c07ea487f4 100644
--- a/drivers/perf/Kconfig
+++ b/drivers/perf/Kconfig
@@ -183,6 +183,13 @@ config APPLE_M1_CPU_PMU
 	  Provides support for the non-architectural CPU PMUs present on
 	  the Apple M1 SoCs and derivatives.
 
+config ALIBABA_UNCORE_DRW_PMU
+	tristate "Alibaba T-Head Yitian 710 DDR Sub-system Driveway PMU driver"
+	depends on ARM64 || COMPILE_TEST
+	help
+	  Support for Driveway PMU events monitoring on Yitian 710 DDR
+	  Sub-system.
+
 source "drivers/perf/hisilicon/Kconfig"
 
 config MARVELL_CN10K_DDR_PMU
diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile
index 57a279c61df5..050d04ee19dd 100644
--- a/drivers/perf/Makefile
+++ b/drivers/perf/Makefile
@@ -20,3 +20,4 @@ obj-$(CONFIG_ARM_DMC620_PMU) += arm_dmc620_pmu.o
 obj-$(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
diff --git a/drivers/perf/alibaba_uncore_drw_pmu.c b/drivers/perf/alibaba_uncore_drw_pmu.c
new file mode 100644
index 000000000000..82729b874f09
--- /dev/null
+++ b/drivers/perf/alibaba_uncore_drw_pmu.c
@@ -0,0 +1,810 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Alibaba DDR Sub-System Driveway PMU driver
+ *
+ * Copyright (C) 2022 Alibaba Inc
+ */
+
+#define ALI_DRW_PMUNAME		"ali_drw"
+#define ALI_DRW_DRVNAME		ALI_DRW_PMUNAME "_pmu"
+#define pr_fmt(fmt)		ALI_DRW_DRVNAME ": " fmt
+
+#include <linux/acpi.h>
+#include <linux/bitfield.h>
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/cpuhotplug.h>
+#include <linux/cpumask.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+#include <linux/rculist.h>
+#include <linux/refcount.h>
+
+
+#define ALI_DRW_PMU_COMMON_MAX_COUNTERS			16
+#define ALI_DRW_PMU_TEST_SEL_COMMON_COUNTER_BASE	19
+
+#define ALI_DRW_PMU_PA_SHIFT			12
+#define ALI_DRW_PMU_CNT_INIT			0x00000000
+#define ALI_DRW_CNT_MAX_PERIOD			0xffffffff
+#define ALI_DRW_PMU_CYCLE_EVT_ID		0x80
+
+#define ALI_DRW_PMU_CNT_CTRL			0xC00
+#define ALI_DRW_PMU_CNT_RST			BIT(2)
+#define ALI_DRW_PMU_CNT_STOP			BIT(1)
+#define ALI_DRW_PMU_CNT_START			BIT(0)
+
+#define ALI_DRW_PMU_CNT_STATE			0xC04
+#define ALI_DRW_PMU_TEST_CTRL			0xC08
+#define ALI_DRW_PMU_CNT_PRELOAD			0xC0C
+
+#define ALI_DRW_PMU_CYCLE_CNT_HIGH_MASK		GENMASK(23, 0)
+#define ALI_DRW_PMU_CYCLE_CNT_LOW_MASK		GENMASK(31, 0)
+#define ALI_DRW_PMU_CYCLE_CNT_HIGH		0xC10
+#define ALI_DRW_PMU_CYCLE_CNT_LOW		0xC14
+
+/* PMU EVENT SEL 0-3 are paired in 32-bit registers on a 4-byte stride */
+#define ALI_DRW_PMU_EVENT_SEL0			0xC68
+/* counter 0-3 use sel0, counter 4-7 use sel1...*/
+#define ALI_DRW_PMU_EVENT_SELn(n) \
+	(ALI_DRW_PMU_EVENT_SEL0 + (n / 4) * 0x4)
+#define ALI_DRW_PMCOM_CNT_EN			BIT(7)
+#define ALI_DRW_PMCOM_CNT_EVENT_MASK		GENMASK(5, 0)
+#define ALI_DRW_PMCOM_CNT_EVENT_OFFSET(n) \
+	(8 * (n % 4))
+
+/* PMU COMMON COUNTER 0-15, are paired in 32-bit registers on a 4-byte stride */
+#define ALI_DRW_PMU_COMMON_COUNTER0		0xC78
+#define ALI_DRW_PMU_COMMON_COUNTERn(n) \
+	(ALI_DRW_PMU_COMMON_COUNTER0 + 0x4 * (n))
+
+#define ALI_DRW_PMU_OV_INTR_ENABLE_CTL		0xCB8
+#define ALI_DRW_PMU_OV_INTR_DISABLE_CTL		0xCBC
+#define ALI_DRW_PMU_OV_INTR_ENABLE_STATUS	0xCC0
+#define ALI_DRW_PMU_OV_INTR_CLR			0xCC4
+#define ALI_DRW_PMU_OV_INTR_STATUS		0xCC8
+#define ALI_DRW_PMCOM_CNT_OV_INTR_MASK		GENMASK(23, 8)
+#define ALI_DRW_PMBW_CNT_OV_INTR_MASK		GENMASK(7, 0)
+#define ALI_DRW_PMU_OV_INTR_MASK		GENMASK_ULL(63, 0)
+
+static int ali_drw_cpuhp_state_num;
+
+static LIST_HEAD(ali_drw_pmu_irqs);
+static DEFINE_MUTEX(ali_drw_pmu_irqs_lock);
+
+struct ali_drw_pmu_irq {
+	struct hlist_node node;
+	struct list_head irqs_node;
+	struct list_head pmus_node;
+	int irq_num;
+	int cpu;
+	refcount_t refcount;
+};
+
+struct ali_drw_pmu {
+	void __iomem *cfg_base;
+	struct device *dev;
+
+	struct list_head pmus_node;
+	struct ali_drw_pmu_irq *irq;
+	int irq_num;
+	int cpu;
+	DECLARE_BITMAP(used_mask, ALI_DRW_PMU_COMMON_MAX_COUNTERS);
+	struct perf_event *events[ALI_DRW_PMU_COMMON_MAX_COUNTERS];
+	int evtids[ALI_DRW_PMU_COMMON_MAX_COUNTERS];
+
+	struct pmu pmu;
+};
+
+#define to_ali_drw_pmu(p) (container_of(p, struct ali_drw_pmu, pmu))
+
+#define DRW_CONFIG_EVENTID		GENMASK(7, 0)
+#define GET_DRW_EVENTID(event)	FIELD_GET(DRW_CONFIG_EVENTID, (event)->attr.config)
+
+static ssize_t ali_drw_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 sprintf(buf, "%s\n", (char *)eattr->var);
+}
+
+/*
+ * PMU event attributes
+ */
+static ssize_t ali_drw_pmu_event_show(struct device *dev,
+			       struct device_attribute *attr, char *page)
+{
+	struct dev_ext_attribute *eattr;
+
+	eattr = container_of(attr, struct dev_ext_attribute, attr);
+
+	return sprintf(page, "config=0x%lx\n", (unsigned long)eattr->var);
+}
+
+#define ALI_DRW_PMU_ATTR(_name, _func, _config)                            \
+		(&((struct dev_ext_attribute[]) {                               \
+				{ __ATTR(_name, 0444, _func, NULL), (void *)_config }   \
+		})[0].attr.attr)
+
+#define ALI_DRW_PMU_FORMAT_ATTR(_name, _config)            \
+	ALI_DRW_PMU_ATTR(_name, ali_drw_pmu_format_show, (void *)_config)
+#define ALI_DRW_PMU_EVENT_ATTR(_name, _config)             \
+	ALI_DRW_PMU_ATTR(_name, ali_drw_pmu_event_show, (unsigned long)_config)
+
+static struct attribute *ali_drw_pmu_events_attrs[] = {
+	ALI_DRW_PMU_EVENT_ATTR(hif_rd_or_wr,			0x0),
+	ALI_DRW_PMU_EVENT_ATTR(hif_wr,				0x1),
+	ALI_DRW_PMU_EVENT_ATTR(hif_rd,				0x2),
+	ALI_DRW_PMU_EVENT_ATTR(hif_rmw,				0x3),
+	ALI_DRW_PMU_EVENT_ATTR(hif_hi_pri_rd,			0x4),
+	ALI_DRW_PMU_EVENT_ATTR(dfi_wr_data_cycles,		0x7),
+	ALI_DRW_PMU_EVENT_ATTR(dfi_rd_data_cycles,		0x8),
+	ALI_DRW_PMU_EVENT_ATTR(hpr_xact_when_critical,		0x9),
+	ALI_DRW_PMU_EVENT_ATTR(lpr_xact_when_critical,		0xA),
+	ALI_DRW_PMU_EVENT_ATTR(wr_xact_when_critical,		0xB),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_activate,			0xC),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_rd_or_wr,			0xD),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_rd_activate,		0xE),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_rd,			0xF),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_wr,			0x10),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_mwr,			0x11),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_precharge,			0x12),
+	ALI_DRW_PMU_EVENT_ATTR(precharge_for_rdwr,		0x13),
+	ALI_DRW_PMU_EVENT_ATTR(precharge_for_other,		0x14),
+	ALI_DRW_PMU_EVENT_ATTR(rdwr_transitions,		0x15),
+	ALI_DRW_PMU_EVENT_ATTR(write_combine,			0x16),
+	ALI_DRW_PMU_EVENT_ATTR(war_hazard,			0x17),
+	ALI_DRW_PMU_EVENT_ATTR(raw_hazard,			0x18),
+	ALI_DRW_PMU_EVENT_ATTR(waw_hazard,			0x19),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_enter_selfref_rk0,		0x1A),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_enter_selfref_rk1,		0x1B),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_enter_selfref_rk2,		0x1C),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_enter_selfref_rk3,		0x1D),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_enter_powerdown_rk0,	0x1E),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_enter_powerdown_rk1,	0x1F),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_enter_powerdown_rk2,	0x20),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_enter_powerdown_rk3,	0x21),
+	ALI_DRW_PMU_EVENT_ATTR(selfref_mode_rk0,		0x26),
+	ALI_DRW_PMU_EVENT_ATTR(selfref_mode_rk1,		0x27),
+	ALI_DRW_PMU_EVENT_ATTR(selfref_mode_rk2,		0x28),
+	ALI_DRW_PMU_EVENT_ATTR(selfref_mode_rk3,		0x29),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_refresh,			0x2A),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_crit_ref,			0x2B),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_load_mode,			0x2D),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_zqcl,			0x2E),
+	ALI_DRW_PMU_EVENT_ATTR(visible_window_limit_reached_rd, 0x30),
+	ALI_DRW_PMU_EVENT_ATTR(visible_window_limit_reached_wr, 0x31),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_dqsosc_mpc,		0x34),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_dqsosc_mrr,		0x35),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_tcr_mrr,			0x36),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_zqstart,			0x37),
+	ALI_DRW_PMU_EVENT_ATTR(op_is_zqlatch,			0x38),
+	ALI_DRW_PMU_EVENT_ATTR(chi_txreq,			0x39),
+	ALI_DRW_PMU_EVENT_ATTR(chi_txdat,			0x3A),
+	ALI_DRW_PMU_EVENT_ATTR(chi_rxdat,			0x3B),
+	ALI_DRW_PMU_EVENT_ATTR(chi_rxrsp,			0x3C),
+	ALI_DRW_PMU_EVENT_ATTR(tsz_vio,				0x3D),
+	ALI_DRW_PMU_EVENT_ATTR(cycle,				0x80),
+	NULL,
+};
+
+static struct attribute_group ali_drw_pmu_events_attr_group = {
+	.name = "events",
+	.attrs = ali_drw_pmu_events_attrs,
+};
+
+static struct attribute *ali_drw_pmu_format_attr[] = {
+	ALI_DRW_PMU_FORMAT_ATTR(event, "config:0-7"),
+	NULL,
+};
+
+static const struct attribute_group ali_drw_pmu_format_group = {
+	.name = "format",
+	.attrs = ali_drw_pmu_format_attr,
+};
+
+static ssize_t ali_drw_pmu_cpumask_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct ali_drw_pmu *drw_pmu = to_ali_drw_pmu(dev_get_drvdata(dev));
+
+	return cpumap_print_to_pagebuf(true, buf, cpumask_of(drw_pmu->cpu));
+}
+
+static struct device_attribute ali_drw_pmu_cpumask_attr =
+		__ATTR(cpumask, 0444, ali_drw_pmu_cpumask_show, NULL);
+
+static struct attribute *ali_drw_pmu_cpumask_attrs[] = {
+	&ali_drw_pmu_cpumask_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ali_drw_pmu_cpumask_attr_group = {
+	.attrs = ali_drw_pmu_cpumask_attrs,
+};
+
+static const struct attribute_group *ali_drw_pmu_attr_groups[] = {
+	&ali_drw_pmu_events_attr_group,
+	&ali_drw_pmu_cpumask_attr_group,
+	&ali_drw_pmu_format_group,
+	NULL,
+};
+
+/* find a counter for event, then in add func, hw.idx will equal to counter */
+static int ali_drw_get_counter_idx(struct perf_event *event)
+{
+	struct ali_drw_pmu *drw_pmu = to_ali_drw_pmu(event->pmu);
+	int idx;
+
+	for (idx = 0; idx < ALI_DRW_PMU_COMMON_MAX_COUNTERS; ++idx) {
+		if (!test_and_set_bit(idx, drw_pmu->used_mask))
+			return idx;
+	}
+
+	/* The counters are all in use. */
+	return -EBUSY;
+}
+
+static u64 ali_drw_pmu_read_counter(struct perf_event *event)
+{
+	struct ali_drw_pmu *drw_pmu = to_ali_drw_pmu(event->pmu);
+	u64 cycle_high, cycle_low;
+
+	if (GET_DRW_EVENTID(event) == ALI_DRW_PMU_CYCLE_EVT_ID) {
+		cycle_high = readl(drw_pmu->cfg_base + ALI_DRW_PMU_CYCLE_CNT_HIGH);
+		cycle_high &= ALI_DRW_PMU_CYCLE_CNT_HIGH_MASK;
+		cycle_low = readl(drw_pmu->cfg_base + ALI_DRW_PMU_CYCLE_CNT_LOW);
+		cycle_low &= ALI_DRW_PMU_CYCLE_CNT_LOW_MASK;
+		return (cycle_high << 32 | cycle_low);
+	}
+
+	return readl(drw_pmu->cfg_base +
+		     ALI_DRW_PMU_COMMON_COUNTERn(event->hw.idx));
+}
+
+static void ali_drw_pmu_event_update(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	u64 delta, prev, now;
+
+	do {
+		prev = local64_read(&hwc->prev_count);
+		now = ali_drw_pmu_read_counter(event);
+	} while (local64_cmpxchg(&hwc->prev_count, prev, now) != prev);
+
+	/* handle overflow. */
+	delta = now - prev;
+	if (GET_DRW_EVENTID(event) == ALI_DRW_PMU_CYCLE_EVT_ID)
+		delta &= ALI_DRW_PMU_OV_INTR_MASK;
+	else
+		delta &= ALI_DRW_CNT_MAX_PERIOD;
+	local64_add(delta, &event->count);
+}
+
+static void ali_drw_pmu_event_set_period(struct perf_event *event)
+{
+	u64 pre_val;
+	struct ali_drw_pmu *drw_pmu = to_ali_drw_pmu(event->pmu);
+
+	/* set a preload counter for test purpose */
+	writel(ALI_DRW_PMU_TEST_SEL_COMMON_COUNTER_BASE + event->hw.idx,
+	       drw_pmu->cfg_base + ALI_DRW_PMU_TEST_CTRL);
+
+	/* set conunter initial value */
+	pre_val = ALI_DRW_PMU_CNT_INIT;
+	writel(pre_val, drw_pmu->cfg_base + ALI_DRW_PMU_CNT_PRELOAD);
+	local64_set(&event->hw.prev_count, pre_val);
+
+	/* set sel mode to zero to start test */
+	writel(0x0, drw_pmu->cfg_base + ALI_DRW_PMU_TEST_CTRL);
+}
+
+static void ali_drw_pmu_enable_counter(struct perf_event *event)
+{
+	u32 val, subval, reg, shift;
+	int counter = event->hw.idx;
+	struct ali_drw_pmu *drw_pmu = to_ali_drw_pmu(event->pmu);
+
+	reg = ALI_DRW_PMU_EVENT_SELn(counter);
+	val = readl(drw_pmu->cfg_base + reg);
+	subval = FIELD_PREP(ALI_DRW_PMCOM_CNT_EN, 1) |
+		 FIELD_PREP(ALI_DRW_PMCOM_CNT_EVENT_MASK, drw_pmu->evtids[counter]);
+
+	shift = ALI_DRW_PMCOM_CNT_EVENT_OFFSET(counter);
+	val &= ~(GENMASK(7, 0) << shift);
+	val |= subval << shift;
+
+	writel(val, drw_pmu->cfg_base + reg);
+}
+
+static void ali_drw_pmu_disable_counter(struct perf_event *event)
+{
+	u32 val, reg, subval, shift;
+	struct ali_drw_pmu *drw_pmu = to_ali_drw_pmu(event->pmu);
+	int counter = event->hw.idx;
+
+	reg = ALI_DRW_PMU_EVENT_SELn(counter);
+	val = readl(drw_pmu->cfg_base + reg);
+	subval = FIELD_PREP(ALI_DRW_PMCOM_CNT_EN, 0) |
+		 FIELD_PREP(ALI_DRW_PMCOM_CNT_EVENT_MASK, 0);
+
+	shift = ALI_DRW_PMCOM_CNT_EVENT_OFFSET(counter);
+	val &= ~(GENMASK(7, 0) << shift);
+	val |= subval << shift;
+
+	writel(val, drw_pmu->cfg_base + reg);
+}
+
+static irqreturn_t ali_drw_pmu_isr(int irq_num, void *data)
+{
+	struct ali_drw_pmu_irq *irq = data;
+	struct ali_drw_pmu *drw_pmu;
+	irqreturn_t ret = IRQ_NONE;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(drw_pmu, &irq->pmus_node, pmus_node) {
+		unsigned long status, clr_status;
+		struct perf_event *event;
+		unsigned int idx;
+
+		for (idx = 0; idx < ALI_DRW_PMU_COMMON_MAX_COUNTERS; idx++) {
+			event = drw_pmu->events[idx];
+			if (!event)
+				continue;
+			ali_drw_pmu_disable_counter(event);
+		}
+
+		/* common counter intr status */
+		status = readl(drw_pmu->cfg_base + ALI_DRW_PMU_OV_INTR_STATUS);
+		status = FIELD_GET(ALI_DRW_PMCOM_CNT_OV_INTR_MASK, status);
+		if (status) {
+			for_each_set_bit(idx, &status,
+					 ALI_DRW_PMU_COMMON_MAX_COUNTERS) {
+				event = drw_pmu->events[idx];
+				if (WARN_ON_ONCE(!event))
+					continue;
+				ali_drw_pmu_event_update(event);
+				ali_drw_pmu_event_set_period(event);
+			}
+
+			/* clear common counter intr status */
+			clr_status = FIELD_PREP(ALI_DRW_PMCOM_CNT_OV_INTR_MASK, 1);
+			writel(clr_status,
+			       drw_pmu->cfg_base + ALI_DRW_PMU_OV_INTR_CLR);
+		}
+
+		for (idx = 0; idx < ALI_DRW_PMU_COMMON_MAX_COUNTERS; idx++) {
+			event = drw_pmu->events[idx];
+			if (!event)
+				continue;
+			if (!(event->hw.state & PERF_HES_STOPPED))
+				ali_drw_pmu_enable_counter(event);
+		}
+		if (status)
+			ret = IRQ_HANDLED;
+	}
+	rcu_read_unlock();
+	return ret;
+}
+
+static struct ali_drw_pmu_irq *__ali_drw_pmu_init_irq(struct platform_device
+						      *pdev, int irq_num)
+{
+	int ret;
+	struct ali_drw_pmu_irq *irq;
+
+	list_for_each_entry(irq, &ali_drw_pmu_irqs, irqs_node) {
+		if (irq->irq_num == irq_num
+		    && refcount_inc_not_zero(&irq->refcount))
+			return irq;
+	}
+
+	irq = kzalloc(sizeof(*irq), GFP_KERNEL);
+	if (!irq)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&irq->pmus_node);
+
+	/* Pick one CPU to be the preferred one to use */
+	irq->cpu = smp_processor_id();
+	refcount_set(&irq->refcount, 1);
+
+	/*
+	 * FIXME: one of DDRSS Driveway PMU overflow interrupt shares the same
+	 * irq number with MPAM ERR_IRQ. To register DDRSS PMU and MPAM drivers
+	 * successfully, add IRQF_SHARED flag. Howerer, PMU interrupt should not
+	 * share with other component.
+	 */
+	ret = devm_request_irq(&pdev->dev, irq_num, ali_drw_pmu_isr,
+			       IRQF_SHARED, dev_name(&pdev->dev), irq);
+	if (ret < 0) {
+		dev_err(&pdev->dev,
+			"Fail to request IRQ:%d ret:%d\n", irq_num, ret);
+		goto out_free;
+	}
+
+	ret = irq_set_affinity_hint(irq_num, cpumask_of(irq->cpu));
+	if (ret)
+		goto out_free;
+
+	ret = cpuhp_state_add_instance_nocalls(ali_drw_cpuhp_state_num,
+					     &irq->node);
+	if (ret)
+		goto out_free;
+
+	irq->irq_num = irq_num;
+	list_add(&irq->irqs_node, &ali_drw_pmu_irqs);
+
+	return irq;
+
+out_free:
+	kfree(irq);
+	return ERR_PTR(ret);
+}
+
+static int ali_drw_pmu_init_irq(struct ali_drw_pmu *drw_pmu,
+				struct platform_device *pdev)
+{
+	int irq_num;
+	struct ali_drw_pmu_irq *irq;
+
+	/* Read and init IRQ */
+	irq_num = platform_get_irq(pdev, 0);
+	if (irq_num < 0)
+		return irq_num;
+
+	mutex_lock(&ali_drw_pmu_irqs_lock);
+	irq = __ali_drw_pmu_init_irq(pdev, irq_num);
+	mutex_unlock(&ali_drw_pmu_irqs_lock);
+
+	if (IS_ERR(irq))
+		return PTR_ERR(irq);
+
+	drw_pmu->irq = irq;
+
+	mutex_lock(&ali_drw_pmu_irqs_lock);
+	list_add_rcu(&drw_pmu->pmus_node, &irq->pmus_node);
+	mutex_unlock(&ali_drw_pmu_irqs_lock);
+
+	return 0;
+}
+
+static void ali_drw_pmu_uninit_irq(struct ali_drw_pmu *drw_pmu)
+{
+	struct ali_drw_pmu_irq *irq = drw_pmu->irq;
+
+	mutex_lock(&ali_drw_pmu_irqs_lock);
+	list_del_rcu(&drw_pmu->pmus_node);
+
+	if (!refcount_dec_and_test(&irq->refcount)) {
+		mutex_unlock(&ali_drw_pmu_irqs_lock);
+		return;
+	}
+
+	list_del(&irq->irqs_node);
+	mutex_unlock(&ali_drw_pmu_irqs_lock);
+
+	WARN_ON(irq_set_affinity_hint(irq->irq_num, NULL));
+	cpuhp_state_remove_instance_nocalls(ali_drw_cpuhp_state_num,
+					    &irq->node);
+	kfree(irq);
+}
+
+static int ali_drw_pmu_event_init(struct perf_event *event)
+{
+	struct ali_drw_pmu *drw_pmu = to_ali_drw_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+	struct perf_event *sibling;
+	struct device *dev = drw_pmu->pmu.dev;
+
+	if (event->attr.type != event->pmu->type)
+		return -ENOENT;
+
+	if (is_sampling_event(event)) {
+		dev_err(dev, "Sampling not supported!\n");
+		return -EOPNOTSUPP;
+	}
+
+	if (event->attach_state & PERF_ATTACH_TASK) {
+		dev_err(dev, "Per-task counter cannot allocate!\n");
+		return -EOPNOTSUPP;
+	}
+
+	event->cpu = drw_pmu->cpu;
+	if (event->cpu < 0) {
+		dev_err(dev, "Per-task mode not supported!\n");
+		return -EOPNOTSUPP;
+	}
+
+	if (event->group_leader != event &&
+	    !is_software_event(event->group_leader)) {
+		dev_err(dev, "driveway only allow one event!\n");
+		return -EINVAL;
+	}
+
+	for_each_sibling_event(sibling, event->group_leader) {
+		if (sibling != event && !is_software_event(sibling)) {
+			dev_err(dev, "driveway event not allowed!\n");
+			return -EINVAL;
+		}
+	}
+
+	/* reset all the pmu counters */
+	writel(ALI_DRW_PMU_CNT_RST, drw_pmu->cfg_base + ALI_DRW_PMU_CNT_CTRL);
+
+	hwc->idx = -1;
+
+	return 0;
+}
+
+static void ali_drw_pmu_start(struct perf_event *event, int flags)
+{
+	struct ali_drw_pmu *drw_pmu = to_ali_drw_pmu(event->pmu);
+
+	event->hw.state = 0;
+
+	if (GET_DRW_EVENTID(event) == ALI_DRW_PMU_CYCLE_EVT_ID) {
+		writel(ALI_DRW_PMU_CNT_START,
+		       drw_pmu->cfg_base + ALI_DRW_PMU_CNT_CTRL);
+		return;
+	}
+
+	ali_drw_pmu_event_set_period(event);
+	if (flags & PERF_EF_RELOAD) {
+		unsigned long prev_raw_count =
+		    local64_read(&event->hw.prev_count);
+		writel(prev_raw_count,
+		       drw_pmu->cfg_base + ALI_DRW_PMU_CNT_PRELOAD);
+	}
+
+	ali_drw_pmu_enable_counter(event);
+
+	writel(ALI_DRW_PMU_CNT_START, drw_pmu->cfg_base + ALI_DRW_PMU_CNT_CTRL);
+}
+
+static void ali_drw_pmu_stop(struct perf_event *event, int flags)
+{
+	struct ali_drw_pmu *drw_pmu = to_ali_drw_pmu(event->pmu);
+
+	if (event->hw.state & PERF_HES_STOPPED)
+		return;
+
+	if (GET_DRW_EVENTID(event) != ALI_DRW_PMU_CYCLE_EVT_ID)
+		ali_drw_pmu_disable_counter(event);
+
+	writel(ALI_DRW_PMU_CNT_STOP, drw_pmu->cfg_base + ALI_DRW_PMU_CNT_CTRL);
+
+	ali_drw_pmu_event_update(event);
+	event->hw.state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
+}
+
+static int ali_drw_pmu_add(struct perf_event *event, int flags)
+{
+	struct ali_drw_pmu *drw_pmu = to_ali_drw_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+	int idx = -1;
+	int evtid;
+
+	evtid = GET_DRW_EVENTID(event);
+
+	if (evtid != ALI_DRW_PMU_CYCLE_EVT_ID) {
+		idx = ali_drw_get_counter_idx(event);
+		if (idx < 0)
+			return idx;
+		drw_pmu->events[idx] = event;
+		drw_pmu->evtids[idx] = evtid;
+	}
+	hwc->idx = idx;
+
+	hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+
+	if (flags & PERF_EF_START)
+		ali_drw_pmu_start(event, PERF_EF_RELOAD);
+
+	/* Propagate our changes to the userspace mapping. */
+	perf_event_update_userpage(event);
+
+	return 0;
+}
+
+static void ali_drw_pmu_del(struct perf_event *event, int flags)
+{
+	struct ali_drw_pmu *drw_pmu = to_ali_drw_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+	int idx = hwc->idx;
+
+	ali_drw_pmu_stop(event, PERF_EF_UPDATE);
+
+	if (idx >= 0 && idx < ALI_DRW_PMU_COMMON_MAX_COUNTERS) {
+		drw_pmu->events[idx] = NULL;
+		drw_pmu->evtids[idx] = 0;
+		clear_bit(idx, drw_pmu->used_mask);
+	}
+
+	perf_event_update_userpage(event);
+}
+
+static void ali_drw_pmu_read(struct perf_event *event)
+{
+	ali_drw_pmu_event_update(event);
+}
+
+static int ali_drw_pmu_probe(struct platform_device *pdev)
+{
+	struct ali_drw_pmu *drw_pmu;
+	struct resource *res;
+	char *name;
+	int ret;
+
+	drw_pmu = devm_kzalloc(&pdev->dev, sizeof(*drw_pmu), GFP_KERNEL);
+	if (!drw_pmu)
+		return -ENOMEM;
+
+	drw_pmu->dev = &pdev->dev;
+	platform_set_drvdata(pdev, drw_pmu);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	drw_pmu->cfg_base = devm_ioremap_resource(&pdev->dev, res);
+	if (!drw_pmu->cfg_base)
+		return -ENOMEM;
+
+	name = devm_kasprintf(drw_pmu->dev, GFP_KERNEL, "ali_drw_%llx",
+			      (u64) (res->start >> ALI_DRW_PMU_PA_SHIFT));
+	if (!name)
+		return -ENOMEM;
+
+	writel(ALI_DRW_PMU_CNT_RST, drw_pmu->cfg_base + ALI_DRW_PMU_CNT_CTRL);
+
+	/* enable the generation of interrupt by all common counters */
+	writel(ALI_DRW_PMCOM_CNT_OV_INTR_MASK,
+	       drw_pmu->cfg_base + ALI_DRW_PMU_OV_INTR_ENABLE_CTL);
+
+	/* clearing interrupt status */
+	writel(0xffffff, drw_pmu->cfg_base + ALI_DRW_PMU_OV_INTR_CLR);
+
+	drw_pmu->cpu = smp_processor_id();
+
+	ret = ali_drw_pmu_init_irq(drw_pmu, pdev);
+	if (ret)
+		return ret;
+
+	drw_pmu->pmu = (struct pmu) {
+		.module		= THIS_MODULE,
+		.task_ctx_nr	= perf_invalid_context,
+		.event_init	= ali_drw_pmu_event_init,
+		.add		= ali_drw_pmu_add,
+		.del		= ali_drw_pmu_del,
+		.start		= ali_drw_pmu_start,
+		.stop		= ali_drw_pmu_stop,
+		.read		= ali_drw_pmu_read,
+		.attr_groups	= ali_drw_pmu_attr_groups,
+		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
+	};
+
+	ret = perf_pmu_register(&drw_pmu->pmu, name, -1);
+	if (ret) {
+		dev_err(drw_pmu->dev, "DRW Driveway PMU PMU register failed!\n");
+		ali_drw_pmu_uninit_irq(drw_pmu);
+	}
+
+	return ret;
+}
+
+static int ali_drw_pmu_remove(struct platform_device *pdev)
+{
+	struct ali_drw_pmu *drw_pmu = platform_get_drvdata(pdev);
+
+	/* disable the generation of interrupt by all common counters */
+	writel(ALI_DRW_PMCOM_CNT_OV_INTR_MASK,
+	       drw_pmu->cfg_base + ALI_DRW_PMU_OV_INTR_DISABLE_CTL);
+
+	ali_drw_pmu_uninit_irq(drw_pmu);
+	perf_pmu_unregister(&drw_pmu->pmu);
+
+	return 0;
+}
+
+static int ali_drw_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
+{
+	struct ali_drw_pmu_irq *irq;
+	struct ali_drw_pmu *drw_pmu;
+	unsigned int target;
+	int ret;
+	cpumask_t node_online_cpus;
+
+	irq = hlist_entry_safe(node, struct ali_drw_pmu_irq, node);
+	if (cpu != irq->cpu)
+		return 0;
+
+	ret = cpumask_and(&node_online_cpus,
+			  cpumask_of_node(cpu_to_node(cpu)), cpu_online_mask);
+	if (ret)
+		target = cpumask_any_but(&node_online_cpus, cpu);
+	else
+		target = cpumask_any_but(cpu_online_mask, cpu);
+
+	if (target >= nr_cpu_ids)
+		return 0;
+
+	/* We're only reading, but this isn't the place to be involving RCU */
+	mutex_lock(&ali_drw_pmu_irqs_lock);
+	list_for_each_entry(drw_pmu, &irq->pmus_node, pmus_node)
+		perf_pmu_migrate_context(&drw_pmu->pmu, irq->cpu, target);
+	mutex_unlock(&ali_drw_pmu_irqs_lock);
+
+	WARN_ON(irq_set_affinity_hint(irq->irq_num, cpumask_of(target)));
+	irq->cpu = target;
+
+	return 0;
+}
+
+/*
+ * Due to historical reasons, the HID used in the production environment is
+ * ARMHD700, so we leave ARMHD700 as Compatible ID.
+ */
+static const struct acpi_device_id ali_drw_acpi_match[] = {
+	{"BABA5000", 0},
+	{"ARMHD700", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(acpi, ali_drw_acpi_match);
+
+static struct platform_driver ali_drw_pmu_driver = {
+	.driver = {
+		   .name = "ali_drw_pmu",
+		   .acpi_match_table = ali_drw_acpi_match,
+		   },
+	.probe = ali_drw_pmu_probe,
+	.remove = ali_drw_pmu_remove,
+};
+
+static int __init ali_drw_pmu_init(void)
+{
+	int ret;
+
+	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
+				      "ali_drw_pmu:online",
+				      NULL, ali_drw_pmu_offline_cpu);
+
+	if (ret < 0) {
+		pr_err("DRW Driveway PMU: setup hotplug failed, ret = %d\n",
+		       ret);
+		return ret;
+	}
+	ali_drw_cpuhp_state_num = ret;
+
+	ret = platform_driver_register(&ali_drw_pmu_driver);
+	if (ret)
+		cpuhp_remove_multi_state(ali_drw_cpuhp_state_num);
+
+	return ret;
+}
+
+static void __exit ali_drw_pmu_exit(void)
+{
+	platform_driver_unregister(&ali_drw_pmu_driver);
+	cpuhp_remove_multi_state(ali_drw_cpuhp_state_num);
+}
+
+module_init(ali_drw_pmu_init);
+module_exit(ali_drw_pmu_exit);
+
+MODULE_AUTHOR("Hongbo Yao <yaohongbo@linux.alibaba.com>");
+MODULE_AUTHOR("Neng Chen <nengchen@linux.alibaba.com>");
+MODULE_AUTHOR("Shuai Xue <xueshuai@linux.alibaba.com>");
+MODULE_DESCRIPTION("Alibaba DDR Sub-System Driveway PMU driver");
+MODULE_LICENSE("GPL v2");