[PATCH v5 2/2] ThunderX2: Add Cavium ThunderX2 SoC UNCORE PMU driver

[Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>]

This patch adds a perf driver for the PMU UNCORE devices DDR4 Memory
Controller(DMC) and Level 3 Cache(L3C).

ThunderX2 has 8 independent DMC PMUs to capture performance events
corresponding to 8 channels of DDR4 Memory Controller and 16 independent
L3C PMUs to capture events corresponding to 16 tiles of L3 cache.
Each PMU supports up to 4 counters. All counters lack overflow interrupt
and are sampled periodically.

Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
---
 drivers/perf/Kconfig         |   8 +
 drivers/perf/Makefile        |   1 +
 drivers/perf/thunderx2_pmu.c | 965 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/cpuhotplug.h   |   1 +
 4 files changed, 975 insertions(+)
 create mode 100644 drivers/perf/thunderx2_pmu.c

diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
index 28bb5a0..eafd0fc 100644
--- a/drivers/perf/Kconfig
+++ b/drivers/perf/Kconfig
@@ -85,6 +85,14 @@ config QCOM_L3_PMU
 	   Adds the L3 cache PMU into the perf events subsystem for
 	   monitoring L3 cache events.
 
+config THUNDERX2_PMU
+        bool "Cavium ThunderX2 SoC PMU UNCORE"
+        depends on ARCH_THUNDER2 && PERF_EVENTS && ACPI
+	help
+	  Provides support for ThunderX2 UNCORE events.
+	  The SoC has PMU support in its L3 cache controller (L3C) and
+	  in the DDR4 Memory Controller (DMC).
+
 config XGENE_PMU
         depends on ARCH_XGENE
         bool "APM X-Gene SoC PMU"
diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile
index b3902bd..909f27f 100644
--- a/drivers/perf/Makefile
+++ b/drivers/perf/Makefile
@@ -7,5 +7,6 @@ obj-$(CONFIG_ARM_PMU_ACPI) += arm_pmu_acpi.o
 obj-$(CONFIG_HISI_PMU) += hisilicon/
 obj-$(CONFIG_QCOM_L2_PMU)	+= qcom_l2_pmu.o
 obj-$(CONFIG_QCOM_L3_PMU) += qcom_l3_pmu.o
+obj-$(CONFIG_THUNDERX2_PMU) += thunderx2_pmu.o
 obj-$(CONFIG_XGENE_PMU) += xgene_pmu.o
 obj-$(CONFIG_ARM_SPE_PMU) += arm_spe_pmu.o
diff --git a/drivers/perf/thunderx2_pmu.c b/drivers/perf/thunderx2_pmu.c
new file mode 100644
index 0000000..0401443
--- /dev/null
+++ b/drivers/perf/thunderx2_pmu.c
@@ -0,0 +1,965 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CAVIUM THUNDERX2 SoC PMU UNCORE
+ *
+ * Copyright (C) 2018 Cavium Inc.
+ * Author: Ganapatrao Kulkarni <gkulkarni@cavium.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/acpi.h>
+#include <linux/arm-smccc.h>
+#include <linux/cpuhotplug.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+
+/* L3c and DMC has 16 and 8 channels per socket respectively.
+ * Each Channel supports UNCORE PMU device and consists of
+ * 4 independent programmable counters. Counters are 32 bit
+ * and does not support overflow interrupt, they needs to be
+ * sampled before overflow(i.e, at every 2 seconds).
+ */
+
+#define UNCORE_MAX_COUNTERS		4
+#define UNCORE_L3_MAX_TILES		16
+#define UNCORE_DMC_MAX_CHANNELS		8
+
+#define UNCORE_HRTIMER_INTERVAL		(2 * NSEC_PER_SEC)
+#define GET_EVENTID(ev)			((ev->hw.config) & 0x1ff)
+#define GET_COUNTERID(ev)		((ev->hw.idx) & 0xf)
+#define GET_CHANNELID(pmu_uncore)	(pmu_uncore->channel)
+#define DMC_EVENT_CFG(idx, val)		((val) << (((idx) * 8) + 1))
+
+#define DMC_COUNTER_CTL			0x234
+#define DMC_COUNTER_DATA		0x240
+#define L3C_COUNTER_CTL			0xA8
+#define L3C_COUNTER_DATA		0xAC
+
+#define THUNDERX2_SMC_CALL_ID		0xC200FF00
+#define THUNDERX2_SMC_SET_CHANNEL	0xB010
+
+enum thunderx2_uncore_l3_events {
+	L3_EVENT_NONE,
+	L3_EVENT_NBU_CANCEL,
+	L3_EVENT_DIB_RETRY,
+	L3_EVENT_DOB_RETRY,
+	L3_EVENT_DIB_CREDIT_RETRY,
+	L3_EVENT_DOB_CREDIT_RETRY,
+	L3_EVENT_FORCE_RETRY,
+	L3_EVENT_IDX_CONFLICT_RETRY,
+	L3_EVENT_EVICT_CONFLICT_RETRY,
+	L3_EVENT_BANK_CONFLICT_RETRY,
+	L3_EVENT_FILL_ENTRY_RETRY,
+	L3_EVENT_EVICT_NOT_READY_RETRY,
+	L3_EVENT_L3_RETRY,
+	L3_EVENT_READ_REQ,
+	L3_EVENT_WRITE_BACK_REQ,
+	L3_EVENT_INVALIDATE_NWRITE_REQ,
+	L3_EVENT_INV_REQ,
+	L3_EVENT_SELF_REQ,
+	L3_EVENT_REQ,
+	L3_EVENT_EVICT_REQ,
+	L3_EVENT_INVALIDATE_NWRITE_HIT,
+	L3_EVENT_INVALIDATE_HIT,
+	L3_EVENT_SELF_HIT,
+	L3_EVENT_READ_HIT,
+	L3_EVENT_MAX,
+};
+
+enum thunderx2_uncore_dmc_events {
+	DMC_EVENT_NONE,
+	DMC_EVENT_COUNT_CYCLES,
+	DMC_EVENT_RES2,
+	DMC_EVENT_RES3,
+	DMC_EVENT_RES4,
+	DMC_EVENT_RES5,
+	DMC_EVENT_RES6,
+	DMC_EVENT_RES7,
+	DMC_EVENT_RES8,
+	DMC_EVENT_READ_64B_TXNS,
+	DMC_EVENT_READ_BELOW_64B_TXNS,
+	DMC_EVENT_WRITE_TXNS,
+	DMC_EVENT_TXN_CYCLES,
+	DMC_EVENT_DATA_TRANSFERS,
+	DMC_EVENT_CANCELLED_READ_TXNS,
+	DMC_EVENT_CONSUMED_READ_TXNS,
+	DMC_EVENT_MAX,
+};
+
+enum thunderx2_uncore_type {
+	PMU_TYPE_L3C,
+	PMU_TYPE_DMC,
+	PMU_TYPE_INVALID,
+};
+
+/*
+ * pmu on each socket has 2 uncore devices(dmc and l3),
+ * each uncore device has up to 16 channels, each channel can sample
+ * events independently with counters up to 4.
+ *
+ * struct thunderx2_pmu_uncore_channel created per channel.
+ * struct thunderx2_pmu_uncore_dev per uncore device.
+ */
+struct thunderx2_pmu_uncore_channel {
+	struct pmu pmu;
+	struct hlist_node	node;
+	struct thunderx2_pmu_uncore_dev *uncore_dev;
+	int channel;
+	int cpu;
+	DECLARE_BITMAP(active_counters, UNCORE_MAX_COUNTERS);
+	struct perf_event *events[UNCORE_MAX_COUNTERS];
+	struct hrtimer hrtimer;
+	/* to sync counter alloc/release */
+	raw_spinlock_t lock;
+};
+
+struct thunderx2_pmu_uncore_dev {
+	char *name;
+	struct device *dev;
+	enum thunderx2_uncore_type type;
+	void __iomem *base;
+	int node;
+	u32    max_counters;
+	u32    max_channels;
+	u32    max_events;
+	u64 hrtimer_interval;
+	/* this lock synchronizes across channels */
+	raw_spinlock_t lock;
+	const struct attribute_group **attr_groups;
+	void	(*init_cntr_base)(struct perf_event *event,
+			struct thunderx2_pmu_uncore_dev *uncore_dev);
+	void	(*select_channel)(struct perf_event *event);
+	void	(*stop_event)(struct perf_event *event);
+	void	(*start_event)(struct perf_event *event, int flags);
+};
+
+static inline struct thunderx2_pmu_uncore_channel *
+pmu_to_thunderx2_pmu_uncore(struct pmu *pmu)
+{
+	return container_of(pmu, struct thunderx2_pmu_uncore_channel, pmu);
+}
+
+/*
+ * sysfs format attributes
+ */
+static ssize_t thunderx2_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);
+}
+
+#define FORMAT_ATTR(_name, _config) \
+	(&((struct dev_ext_attribute[]) { \
+	   { \
+	   .attr = __ATTR(_name, 0444, thunderx2_pmu_format_show, NULL), \
+	   .var = (void *) _config, \
+	   } \
+	})[0].attr.attr)
+
+static struct attribute *l3c_pmu_format_attrs[] = {
+	FORMAT_ATTR(event,	"config:0-4"),
+	NULL,
+};
+
+static struct attribute *dmc_pmu_format_attrs[] = {
+	FORMAT_ATTR(event,	"config:0-4"),
+	NULL,
+};
+
+static const struct attribute_group l3c_pmu_format_attr_group = {
+	.name = "format",
+	.attrs = l3c_pmu_format_attrs,
+};
+
+static const struct attribute_group dmc_pmu_format_attr_group = {
+	.name = "format",
+	.attrs = dmc_pmu_format_attrs,
+};
+
+/*
+ * sysfs event attributes
+ */
+static ssize_t thunderx2_pmu_event_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, "config=0x%lx\n", (unsigned long) eattr->var);
+}
+
+#define EVENT_ATTR(_name, _config) \
+	(&((struct dev_ext_attribute[]) { \
+	   { \
+	   .attr = __ATTR(_name, 0444, thunderx2_pmu_event_show, NULL), \
+	   .var = (void *) _config, \
+	   } \
+	 })[0].attr.attr)
+
+static struct attribute *l3c_pmu_events_attrs[] = {
+	EVENT_ATTR(nbu_cancel,			L3_EVENT_NBU_CANCEL),
+	EVENT_ATTR(dib_retry,			L3_EVENT_DIB_RETRY),
+	EVENT_ATTR(dob_retry,			L3_EVENT_DOB_RETRY),
+	EVENT_ATTR(dib_credit_retry,		L3_EVENT_DIB_CREDIT_RETRY),
+	EVENT_ATTR(dob_credit_retry,		L3_EVENT_DOB_CREDIT_RETRY),
+	EVENT_ATTR(force_retry,			L3_EVENT_FORCE_RETRY),
+	EVENT_ATTR(idx_conflict_retry,		L3_EVENT_IDX_CONFLICT_RETRY),
+	EVENT_ATTR(evict_conflict_retry,	L3_EVENT_EVICT_CONFLICT_RETRY),
+	EVENT_ATTR(bank_conflict_retry,		L3_EVENT_BANK_CONFLICT_RETRY),
+	EVENT_ATTR(fill_entry_retry,		L3_EVENT_FILL_ENTRY_RETRY),
+	EVENT_ATTR(evict_not_ready_retry,	L3_EVENT_EVICT_NOT_READY_RETRY),
+	EVENT_ATTR(l3_retry,			L3_EVENT_L3_RETRY),
+	EVENT_ATTR(read_request,		L3_EVENT_READ_REQ),
+	EVENT_ATTR(write_back_request,		L3_EVENT_WRITE_BACK_REQ),
+	EVENT_ATTR(inv_nwrite_request,		L3_EVENT_INVALIDATE_NWRITE_REQ),
+	EVENT_ATTR(inv_request,			L3_EVENT_INV_REQ),
+	EVENT_ATTR(self_request,		L3_EVENT_SELF_REQ),
+	EVENT_ATTR(request,			L3_EVENT_REQ),
+	EVENT_ATTR(evict_request,		L3_EVENT_EVICT_REQ),
+	EVENT_ATTR(inv_nwrite_hit,		L3_EVENT_INVALIDATE_NWRITE_HIT),
+	EVENT_ATTR(inv_hit,			L3_EVENT_INVALIDATE_HIT),
+	EVENT_ATTR(self_hit,			L3_EVENT_SELF_HIT),
+	EVENT_ATTR(read_hit,			L3_EVENT_READ_HIT),
+	NULL,
+};
+
+static struct attribute *dmc_pmu_events_attrs[] = {
+	EVENT_ATTR(cnt_cycles,			DMC_EVENT_COUNT_CYCLES),
+	EVENT_ATTR(read_64b_txns,		DMC_EVENT_READ_64B_TXNS),
+	EVENT_ATTR(read_below_64b_txns,		DMC_EVENT_READ_BELOW_64B_TXNS),
+	EVENT_ATTR(write_txns,			DMC_EVENT_WRITE_TXNS),
+	EVENT_ATTR(txn_cycles,			DMC_EVENT_TXN_CYCLES),
+	EVENT_ATTR(data_transfers,		DMC_EVENT_DATA_TRANSFERS),
+	EVENT_ATTR(cancelled_read_txns,		DMC_EVENT_CANCELLED_READ_TXNS),
+	EVENT_ATTR(consumed_read_txns,		DMC_EVENT_CONSUMED_READ_TXNS),
+	NULL,
+};
+
+static const struct attribute_group l3c_pmu_events_attr_group = {
+	.name = "events",
+	.attrs = l3c_pmu_events_attrs,
+};
+
+static const struct attribute_group dmc_pmu_events_attr_group = {
+	.name = "events",
+	.attrs = dmc_pmu_events_attrs,
+};
+
+/*
+ * sysfs cpumask attributes
+ */
+static ssize_t cpumask_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct cpumask cpu_mask;
+	struct thunderx2_pmu_uncore_channel *pmu_uncore =
+		pmu_to_thunderx2_pmu_uncore(dev_get_drvdata(dev));
+
+	cpumask_clear(&cpu_mask);
+	cpumask_set_cpu(pmu_uncore->cpu, &cpu_mask);
+	return cpumap_print_to_pagebuf(true, buf, &cpu_mask);
+}
+static DEVICE_ATTR_RO(cpumask);
+
+static struct attribute *thunderx2_pmu_cpumask_attrs[] = {
+	&dev_attr_cpumask.attr,
+	NULL,
+};
+
+static const struct attribute_group pmu_cpumask_attr_group = {
+	.attrs = thunderx2_pmu_cpumask_attrs,
+};
+
+/*
+ * Per PMU device attribute groups
+ */
+static const struct attribute_group *l3c_pmu_attr_groups[] = {
+	&l3c_pmu_format_attr_group,
+	&pmu_cpumask_attr_group,
+	&l3c_pmu_events_attr_group,
+	NULL
+};
+
+static const struct attribute_group *dmc_pmu_attr_groups[] = {
+	&dmc_pmu_format_attr_group,
+	&pmu_cpumask_attr_group,
+	&dmc_pmu_events_attr_group,
+	NULL
+};
+
+static inline u32 reg_readl(unsigned long addr)
+{
+	return readl((void __iomem *)addr);
+}
+
+static inline void reg_writel(u32 val, unsigned long addr)
+{
+	writel(val, (void __iomem *)addr);
+}
+
+static int alloc_counter(struct thunderx2_pmu_uncore_channel *pmu_uncore)
+{
+	int counter;
+
+	raw_spin_lock(&pmu_uncore->lock);
+	counter = find_first_zero_bit(pmu_uncore->active_counters,
+				pmu_uncore->uncore_dev->max_counters);
+	if (counter == pmu_uncore->uncore_dev->max_counters) {
+		raw_spin_unlock(&pmu_uncore->lock);
+		return -ENOSPC;
+	}
+	set_bit(counter, pmu_uncore->active_counters);
+	raw_spin_unlock(&pmu_uncore->lock);
+	return counter;
+}
+
+static void free_counter(
+		struct thunderx2_pmu_uncore_channel *pmu_uncore, int counter)
+{
+	raw_spin_lock(&pmu_uncore->lock);
+	clear_bit(counter, pmu_uncore->active_counters);
+	raw_spin_unlock(&pmu_uncore->lock);
+}
+
+/*
+ * DMC and L3 counter interface is muxed across all channels.
+ * hence we need to select the channel before accessing counter
+ * data/control registers.
+ *
+ *  L3 Tile and DMC channel selection is through SMC call
+ *  SMC call arguments,
+ *	x0 = THUNDERX2_SMC_CALL_ID	(Vendor SMC call Id)
+ *	x1 = THUNDERX2_SMC_SET_CHANNEL	(Id to set DMC/L3C channel)
+ *	x2 = Node id
+ *	x3 = DMC(1)/L3C(0)
+ *	x4 = channel Id
+ */
+static void uncore_select_channel(struct perf_event *event)
+{
+	struct arm_smccc_res res;
+	struct thunderx2_pmu_uncore_channel *pmu_uncore =
+		pmu_to_thunderx2_pmu_uncore(event->pmu);
+	struct thunderx2_pmu_uncore_dev *uncore_dev =
+		pmu_uncore->uncore_dev;
+
+	arm_smccc_smc(THUNDERX2_SMC_CALL_ID, THUNDERX2_SMC_SET_CHANNEL,
+			uncore_dev->node, uncore_dev->type,
+			pmu_uncore->channel, 0, 0, 0, &res);
+	if (res.a0) {
+		dev_err(uncore_dev->dev,
+			"SMC to Select channel failed for PMU UNCORE[%s]\n",
+				pmu_uncore->uncore_dev->name);
+	}
+}
+
+/* early probe for firmware support */
+static int __init test_uncore_select_channel_early(struct device *dev)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_smc(THUNDERX2_SMC_CALL_ID, THUNDERX2_SMC_SET_CHANNEL,
+			dev_to_node(dev), 0, 0, 0, 0, 0, &res);
+	if (res.a0) {
+		dev_err(dev, "No Firmware support for PMU UNCORE(%d)\n",
+				dev_to_node(dev));
+		return -ENODEV;
+	}
+	return 0;
+}
+
+static void uncore_start_event_l3c(struct perf_event *event, int flags)
+{
+	u32 val;
+	struct hw_perf_event *hwc = &event->hw;
+
+	/* event id encoded in bits [07:03] */
+	val = GET_EVENTID(event) << 3;
+	reg_writel(val, hwc->config_base);
+	local64_set(&hwc->prev_count, 0);
+	reg_writel(0, hwc->event_base);
+}
+
+static void uncore_stop_event_l3c(struct perf_event *event)
+{
+	reg_writel(0, event->hw.config_base);
+}
+
+static void uncore_start_event_dmc(struct perf_event *event, int flags)
+{
+	u32 val;
+	struct hw_perf_event *hwc = &event->hw;
+	int idx = GET_COUNTERID(event);
+	int event_type = GET_EVENTID(event);
+
+	/* enable and start counters.
+	 * 8 bits for each counter, bits[05:01] of a counter to set event type.
+	 */
+	val = reg_readl(hwc->config_base);
+	val &= ~DMC_EVENT_CFG(idx, 0x1f);
+	val |= DMC_EVENT_CFG(idx, event_type);
+	reg_writel(val, hwc->config_base);
+	local64_set(&hwc->prev_count, 0);
+	reg_writel(0, hwc->event_base);
+}
+
+static void uncore_stop_event_dmc(struct perf_event *event)
+{
+	u32 val;
+	struct hw_perf_event *hwc = &event->hw;
+	int idx = GET_COUNTERID(event);
+
+	/* clear event type(bits[05:01]) to stop counter */
+	val = reg_readl(hwc->config_base);
+	val &= ~DMC_EVENT_CFG(idx, 0x1f);
+	reg_writel(val, hwc->config_base);
+}
+
+static void init_cntr_base_l3c(struct perf_event *event,
+		struct thunderx2_pmu_uncore_dev *uncore_dev)
+{
+	struct hw_perf_event *hwc = &event->hw;
+
+	/* counter ctrl/data reg offset at 8 */
+	hwc->config_base = (unsigned long)uncore_dev->base
+		+ L3C_COUNTER_CTL + (8 * GET_COUNTERID(event));
+	hwc->event_base =  (unsigned long)uncore_dev->base
+		+ L3C_COUNTER_DATA + (8 * GET_COUNTERID(event));
+}
+
+static void init_cntr_base_dmc(struct perf_event *event,
+		struct thunderx2_pmu_uncore_dev *uncore_dev)
+{
+	struct hw_perf_event *hwc = &event->hw;
+
+	hwc->config_base = (unsigned long)uncore_dev->base
+		+ DMC_COUNTER_CTL;
+	/* counter data reg offset at 0xc */
+	hwc->event_base = (unsigned long)uncore_dev->base
+		+ DMC_COUNTER_DATA + (0xc * GET_COUNTERID(event));
+}
+
+static void thunderx2_uncore_update(struct perf_event *event)
+{
+	s64 prev, new = 0;
+	u64 delta;
+	struct hw_perf_event *hwc = &event->hw;
+	struct thunderx2_pmu_uncore_channel *pmu_uncore;
+	enum thunderx2_uncore_type type;
+
+	pmu_uncore = pmu_to_thunderx2_pmu_uncore(event->pmu);
+	type = pmu_uncore->uncore_dev->type;
+
+	pmu_uncore->uncore_dev->select_channel(event);
+
+	new = reg_readl(hwc->event_base);
+	prev = local64_xchg(&hwc->prev_count, new);
+
+	/* handles rollover of 32 bit counter */
+	delta = (u32)(((1UL << 32) - prev) + new);
+	local64_add(delta, &event->count);
+}
+
+enum thunderx2_uncore_type get_uncore_device_type(struct acpi_device *adev)
+{
+	int i = 0;
+	struct acpi_uncore_device {
+		__u8 id[ACPI_ID_LEN];
+		enum thunderx2_uncore_type type;
+	} devices[] = {
+		{"CAV901D", PMU_TYPE_L3C},
+		{"CAV901F", PMU_TYPE_DMC},
+		{"", PMU_TYPE_INVALID},
+	};
+
+	while (devices[i].type != PMU_TYPE_INVALID) {
+		if (!strcmp(acpi_device_hid(adev), devices[i].id))
+			return devices[i].type;
+		i++;
+	}
+	return PMU_TYPE_INVALID;
+}
+
+/*
+ * We must NOT create groups containing events from multiple hardware PMUs,
+ * although mixing different software and hardware PMUs is allowed.
+ */
+static bool thunderx2_uncore_validate_event_group(struct perf_event *event)
+{
+	struct pmu *pmu = event->pmu;
+	struct perf_event *leader = event->group_leader;
+	struct perf_event *sibling;
+	int counters = 0;
+
+	if (leader->pmu != event->pmu && !is_software_event(leader))
+		return false;
+
+	for_each_sibling_event(sibling, event->group_leader) {
+		if (is_software_event(sibling))
+			continue;
+		if (sibling->pmu != pmu)
+			return false;
+		counters++;
+	}
+
+	/*
+	 * If the group requires more counters than the HW has,
+	 * it cannot ever be scheduled.
+	 */
+	return counters < UNCORE_MAX_COUNTERS;
+}
+
+static int thunderx2_uncore_event_init(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	struct thunderx2_pmu_uncore_channel *pmu_uncore;
+
+	/* Test the event attr type check for PMU enumeration */
+	if (event->attr.type != event->pmu->type)
+		return -ENOENT;
+
+	/*
+	 * SOC PMU counters are shared across all cores.
+	 * Therefore, it does not support per-process mode.
+	 * Also, it does not support event sampling mode.
+	 */
+	if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
+		return -EINVAL;
+
+	/* SOC counters do not have usr/os/guest/host bits */
+	if (event->attr.exclude_user || event->attr.exclude_kernel ||
+	    event->attr.exclude_host || event->attr.exclude_guest)
+		return -EINVAL;
+
+	if (event->cpu < 0)
+		return -EINVAL;
+
+	pmu_uncore = pmu_to_thunderx2_pmu_uncore(event->pmu);
+	event->cpu = pmu_uncore->cpu;
+
+	if (event->attr.config >= pmu_uncore->uncore_dev->max_events)
+		return -EINVAL;
+
+	/* store event id */
+	hwc->config = event->attr.config;
+
+	/* Validate the group */
+	if (!thunderx2_uncore_validate_event_group(event))
+		return -EINVAL;
+
+	return 0;
+}
+
+static void thunderx2_uncore_start(struct perf_event *event, int flags)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	struct thunderx2_pmu_uncore_channel *pmu_uncore;
+	struct thunderx2_pmu_uncore_dev *uncore_dev;
+	unsigned long irqflags;
+
+	hwc->state = 0;
+	pmu_uncore = pmu_to_thunderx2_pmu_uncore(event->pmu);
+	uncore_dev = pmu_uncore->uncore_dev;
+
+	raw_spin_lock_irqsave(&uncore_dev->lock, irqflags);
+	uncore_dev->select_channel(event);
+	uncore_dev->start_event(event, flags);
+	raw_spin_unlock_irqrestore(&uncore_dev->lock, irqflags);
+
+	perf_event_update_userpage(event);
+
+	if (!find_last_bit(pmu_uncore->active_counters,
+				pmu_uncore->uncore_dev->max_counters)) {
+		hrtimer_start(&pmu_uncore->hrtimer,
+			ns_to_ktime(uncore_dev->hrtimer_interval),
+			HRTIMER_MODE_REL_PINNED);
+	}
+}
+
+static void thunderx2_uncore_stop(struct perf_event *event, int flags)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	struct thunderx2_pmu_uncore_channel *pmu_uncore;
+	struct thunderx2_pmu_uncore_dev *uncore_dev;
+	unsigned long irqflags;
+
+	if (hwc->state & PERF_HES_UPTODATE)
+		return;
+
+	pmu_uncore = pmu_to_thunderx2_pmu_uncore(event->pmu);
+	uncore_dev = pmu_uncore->uncore_dev;
+
+	raw_spin_lock_irqsave(&uncore_dev->lock, irqflags);
+
+	uncore_dev->select_channel(event);
+	uncore_dev->stop_event(event);
+
+	WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
+	hwc->state |= PERF_HES_STOPPED;
+	if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
+		thunderx2_uncore_update(event);
+		hwc->state |= PERF_HES_UPTODATE;
+	}
+	raw_spin_unlock_irqrestore(&uncore_dev->lock, irqflags);
+}
+
+static int thunderx2_uncore_add(struct perf_event *event, int flags)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	struct thunderx2_pmu_uncore_channel *pmu_uncore;
+	struct thunderx2_pmu_uncore_dev *uncore_dev;
+
+	pmu_uncore = pmu_to_thunderx2_pmu_uncore(event->pmu);
+	uncore_dev = pmu_uncore->uncore_dev;
+
+	/* Allocate a free counter */
+	hwc->idx  = alloc_counter(pmu_uncore);
+	if (hwc->idx < 0)
+		return -EAGAIN;
+
+	pmu_uncore->events[hwc->idx] = event;
+	/* set counter control and data registers base address */
+	uncore_dev->init_cntr_base(event, uncore_dev);
+
+	hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
+	if (flags & PERF_EF_START)
+		thunderx2_uncore_start(event, flags);
+
+	return 0;
+}
+
+static void thunderx2_uncore_del(struct perf_event *event, int flags)
+{
+	struct thunderx2_pmu_uncore_channel *pmu_uncore =
+			pmu_to_thunderx2_pmu_uncore(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+
+	thunderx2_uncore_stop(event, PERF_EF_UPDATE);
+
+	/* clear the assigned counter */
+	free_counter(pmu_uncore, GET_COUNTERID(event));
+
+	perf_event_update_userpage(event);
+	pmu_uncore->events[hwc->idx] = NULL;
+	hwc->idx = -1;
+}
+
+static void thunderx2_uncore_read(struct perf_event *event)
+{
+	unsigned long irqflags;
+	struct thunderx2_pmu_uncore_channel *pmu_uncore =
+			pmu_to_thunderx2_pmu_uncore(event->pmu);
+
+	raw_spin_lock_irqsave(&pmu_uncore->uncore_dev->lock, irqflags);
+	thunderx2_uncore_update(event);
+	raw_spin_unlock_irqrestore(&pmu_uncore->uncore_dev->lock, irqflags);
+}
+
+static enum hrtimer_restart thunderx2_uncore_hrtimer_callback(
+		struct hrtimer *hrt)
+{
+	struct thunderx2_pmu_uncore_channel *pmu_uncore;
+	unsigned long irqflags;
+	int idx;
+	bool restart_timer = false;
+
+	pmu_uncore = container_of(hrt, struct thunderx2_pmu_uncore_channel,
+			hrtimer);
+
+	raw_spin_lock_irqsave(&pmu_uncore->uncore_dev->lock, irqflags);
+	for_each_set_bit(idx, pmu_uncore->active_counters,
+			pmu_uncore->uncore_dev->max_counters) {
+		struct perf_event *event = pmu_uncore->events[idx];
+
+		thunderx2_uncore_update(event);
+		restart_timer = true;
+	}
+	raw_spin_unlock_irqrestore(&pmu_uncore->uncore_dev->lock, irqflags);
+
+	if (restart_timer)
+		hrtimer_forward_now(hrt,
+			ns_to_ktime(
+				pmu_uncore->uncore_dev->hrtimer_interval));
+
+	return restart_timer ? HRTIMER_RESTART : HRTIMER_NORESTART;
+}
+
+static int thunderx2_pmu_uncore_register(
+		struct thunderx2_pmu_uncore_channel *pmu_uncore)
+{
+	struct device *dev = pmu_uncore->uncore_dev->dev;
+	char *name = pmu_uncore->uncore_dev->name;
+	int channel = pmu_uncore->channel;
+
+	/* Perf event registration */
+	pmu_uncore->pmu = (struct pmu) {
+		.attr_groups	= pmu_uncore->uncore_dev->attr_groups,
+		.task_ctx_nr	= perf_invalid_context,
+		.event_init	= thunderx2_uncore_event_init,
+		.add		= thunderx2_uncore_add,
+		.del		= thunderx2_uncore_del,
+		.start		= thunderx2_uncore_start,
+		.stop		= thunderx2_uncore_stop,
+		.read		= thunderx2_uncore_read,
+	};
+
+	pmu_uncore->pmu.name = devm_kasprintf(dev, GFP_KERNEL,
+			"%s_%d", name, channel);
+
+	return perf_pmu_register(&pmu_uncore->pmu, pmu_uncore->pmu.name, -1);
+}
+
+static int thunderx2_pmu_uncore_add(struct thunderx2_pmu_uncore_dev *uncore_dev,
+		int channel)
+{
+	struct thunderx2_pmu_uncore_channel *pmu_uncore;
+	int ret, cpu;
+
+	pmu_uncore = devm_kzalloc(uncore_dev->dev, sizeof(*pmu_uncore),
+			GFP_KERNEL);
+	if (!pmu_uncore)
+		return -ENOMEM;
+
+	cpu = cpumask_any_and(cpumask_of_node(uncore_dev->node),
+			cpu_online_mask);
+	if (cpu >= nr_cpu_ids)
+		return -EINVAL;
+
+	pmu_uncore->cpu = cpu;
+	pmu_uncore->channel = channel;
+	pmu_uncore->uncore_dev = uncore_dev;
+
+	hrtimer_init(&pmu_uncore->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	pmu_uncore->hrtimer.function = thunderx2_uncore_hrtimer_callback;
+
+	ret = thunderx2_pmu_uncore_register(pmu_uncore);
+	if (ret) {
+		dev_err(uncore_dev->dev, "%s PMU: Failed to init driver\n",
+				uncore_dev->name);
+		return -ENODEV;
+	}
+
+	/* register hotplug callback for the pmu */
+	ret = cpuhp_state_add_instance(
+			CPUHP_AP_PERF_ARM_THUNDERX2_UNCORE_ONLINE,
+			&pmu_uncore->node);
+	if (ret) {
+		dev_err(uncore_dev->dev, "Error %d registering hotplug", ret);
+		return ret;
+	}
+
+	dev_dbg(uncore_dev->dev, "%s PMU UNCORE registered\n",
+			pmu_uncore->pmu.name);
+	return ret;
+}
+
+static struct thunderx2_pmu_uncore_dev *init_pmu_uncore_dev(
+		struct device *dev, acpi_handle handle,
+		struct acpi_device *adev, u32 type)
+{
+	struct thunderx2_pmu_uncore_dev *uncore_dev;
+	void __iomem *base;
+	struct resource res;
+	struct resource_entry *rentry;
+	struct list_head list;
+	int ret;
+
+	INIT_LIST_HEAD(&list);
+	ret = acpi_dev_get_resources(adev, &list, NULL, NULL);
+	if (ret <= 0) {
+		dev_err(dev, "failed to parse _CRS method, error %d\n", ret);
+		return NULL;
+	}
+
+	list_for_each_entry(rentry, &list, node) {
+		if (resource_type(rentry->res) == IORESOURCE_MEM) {
+			res = *rentry->res;
+			break;
+		}
+	}
+
+	if (!rentry->res)
+		return NULL;
+
+	acpi_dev_free_resource_list(&list);
+	base = devm_ioremap_resource(dev, &res);
+	if (IS_ERR(base)) {
+		dev_err(dev, "PMU type %d: Fail to map resource\n", type);
+		return NULL;
+	}
+
+	uncore_dev = devm_kzalloc(dev, sizeof(*uncore_dev), GFP_KERNEL);
+	if (!uncore_dev)
+		return NULL;
+
+	uncore_dev->dev = dev;
+	uncore_dev->type = type;
+	uncore_dev->base = base;
+	uncore_dev->node = dev_to_node(dev);
+
+	raw_spin_lock_init(&uncore_dev->lock);
+
+	switch (uncore_dev->type) {
+	case PMU_TYPE_L3C:
+		uncore_dev->max_counters = UNCORE_MAX_COUNTERS;
+		uncore_dev->max_channels = UNCORE_L3_MAX_TILES;
+		uncore_dev->max_events = L3_EVENT_MAX;
+		uncore_dev->hrtimer_interval = UNCORE_HRTIMER_INTERVAL;
+		uncore_dev->attr_groups = l3c_pmu_attr_groups;
+		uncore_dev->name = devm_kasprintf(dev, GFP_KERNEL,
+				"uncore_l3c_%d", uncore_dev->node);
+		uncore_dev->init_cntr_base = init_cntr_base_l3c;
+		uncore_dev->start_event = uncore_start_event_l3c;
+		uncore_dev->stop_event = uncore_stop_event_l3c;
+		uncore_dev->select_channel = uncore_select_channel;
+		break;
+	case PMU_TYPE_DMC:
+		uncore_dev->max_counters = UNCORE_MAX_COUNTERS;
+		uncore_dev->max_channels = UNCORE_DMC_MAX_CHANNELS;
+		uncore_dev->max_events = DMC_EVENT_MAX;
+		uncore_dev->hrtimer_interval = UNCORE_HRTIMER_INTERVAL;
+		uncore_dev->attr_groups = dmc_pmu_attr_groups;
+		uncore_dev->name = devm_kasprintf(dev, GFP_KERNEL,
+				"uncore_dmc_%d", uncore_dev->node);
+		uncore_dev->init_cntr_base = init_cntr_base_dmc;
+		uncore_dev->start_event = uncore_start_event_dmc;
+		uncore_dev->stop_event = uncore_stop_event_dmc;
+		uncore_dev->select_channel = uncore_select_channel;
+		break;
+	case PMU_TYPE_INVALID:
+		devm_kfree(dev, uncore_dev);
+		uncore_dev = NULL;
+		break;
+	}
+
+	return uncore_dev;
+}
+
+static acpi_status thunderx2_pmu_uncore_dev_add(acpi_handle handle, u32 level,
+				    void *data, void **return_value)
+{
+	struct thunderx2_pmu_uncore_dev *uncore_dev;
+	struct acpi_device *adev;
+	enum thunderx2_uncore_type type;
+	int channel;
+
+	if (acpi_bus_get_device(handle, &adev))
+		return AE_OK;
+	if (acpi_bus_get_status(adev) || !adev->status.present)
+		return AE_OK;
+
+	type = get_uncore_device_type(adev);
+	if (type == PMU_TYPE_INVALID)
+		return AE_OK;
+
+	uncore_dev = init_pmu_uncore_dev((struct device *)data, handle,
+			adev, type);
+
+	if (!uncore_dev)
+		return AE_ERROR;
+
+	for (channel = 0; channel < uncore_dev->max_channels; channel++) {
+		if (thunderx2_pmu_uncore_add(uncore_dev, channel)) {
+			/* Can't add the PMU device, abort */
+			return AE_ERROR;
+		}
+	}
+	return AE_OK;
+}
+
+static int thunderx2_uncore_pmu_offline_cpu(unsigned int cpu,
+		struct hlist_node *node)
+{
+	int new_cpu;
+	struct thunderx2_pmu_uncore_channel *pmu_uncore;
+
+	pmu_uncore = hlist_entry_safe(node,
+			struct thunderx2_pmu_uncore_channel, node);
+	if (cpu != pmu_uncore->cpu)
+		return 0;
+
+	new_cpu = cpumask_any_and(
+			cpumask_of_node(pmu_uncore->uncore_dev->node),
+			cpu_online_mask);
+	if (new_cpu >= nr_cpu_ids)
+		return 0;
+
+	pmu_uncore->cpu = new_cpu;
+	perf_pmu_migrate_context(&pmu_uncore->pmu, cpu, new_cpu);
+	return 0;
+}
+
+static const struct acpi_device_id thunderx2_uncore_acpi_match[] = {
+	{"CAV901C", 0},
+	{},
+};
+MODULE_DEVICE_TABLE(acpi, thunderx2_uncore_acpi_match);
+
+static int thunderx2_uncore_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	acpi_handle handle;
+	acpi_status status;
+
+	set_dev_node(dev, acpi_get_node(ACPI_HANDLE(dev)));
+
+	/* Make sure firmware supports DMC/L3C set channel smc call */
+	if (test_uncore_select_channel_early(dev))
+		return -ENODEV;
+
+	if (!has_acpi_companion(dev))
+		return -ENODEV;
+
+	handle = ACPI_HANDLE(dev);
+	if (!handle)
+		return -EINVAL;
+
+	/* Walk through the tree for all PMU UNCORE devices */
+	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
+				     thunderx2_pmu_uncore_dev_add,
+				     NULL, dev, NULL);
+	if (ACPI_FAILURE(status)) {
+		dev_err(dev, "failed to probe PMU devices\n");
+		return_ACPI_STATUS(status);
+	}
+
+	dev_info(dev, "node%d: pmu uncore registered\n", dev_to_node(dev));
+	return 0;
+}
+
+static struct platform_driver thunderx2_uncore_driver = {
+	.probe = thunderx2_uncore_probe,
+	.driver = {
+		.name		= "thunderx2-uncore-pmu",
+		.acpi_match_table = ACPI_PTR(thunderx2_uncore_acpi_match),
+	},
+};
+
+static int __init register_thunderx2_uncore_driver(void)
+{
+	int ret;
+
+	ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_THUNDERX2_UNCORE_ONLINE,
+				      "perf/tx2/uncore:online",
+				      NULL,
+				      thunderx2_uncore_pmu_offline_cpu);
+	if (ret)
+		return ret;
+
+	return platform_driver_register(&thunderx2_uncore_driver);
+
+}
+device_initcall(register_thunderx2_uncore_driver);
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 8796ba3..eb0c896 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -161,6 +161,7 @@ enum cpuhp_state {
 	CPUHP_AP_PERF_ARM_L2X0_ONLINE,
 	CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
 	CPUHP_AP_PERF_ARM_QCOM_L3_ONLINE,
+	CPUHP_AP_PERF_ARM_THUNDERX2_UNCORE_ONLINE,
 	CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE,
 	CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE,
 	CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE,
-- 
2.9.4