perf: Add Arm CMN-600 PMU driver

Initial driver for PMU event counting on the Arm CMN-600 interconnect.
CMN sports an obnoxiously complex distributed PMU system as part of
its debug and trace features, which can do all manner of things like
sampling, cross-triggering and generating CoreSight trace. This driver
covers the PMU functionality, plus the relevant aspects of watchpoints
for simply counting matching flits.

Tested-by: Tsahi Zidenberg <[e-mail]>
Tested-by: Tuan Phan <[e-mail]>
Signed-off-by: Robin Murphy <[e-mail]>
Signed-off-by: Will Deacon <[e-mail]>

Documentation/admin-guide/perf/arm-cmn.rst

···
+=============================
+Arm Coherent Mesh Network PMU
+=============================
+
+CMN-600 is a configurable mesh interconnect consisting of a rectangular
+grid of crosspoints (XPs), with each crosspoint supporting up to two
+device ports to which various AMBA CHI agents are attached.
+
+CMN implements a distributed PMU design as part of its debug and trace
+functionality. This consists of a local monitor (DTM) at every XP, which
+counts up to 4 event signals from the connected device nodes and/or the
+XP itself. Overflow from these local counters is accumulated in up to 8
+global counters implemented by the main controller (DTC), which provides
+overall PMU control and interrupts for global counter overflow.
+
+PMU events
+----------
+
+The PMU driver registers a single PMU device for the whole interconnect,
+see /sys/bus/event_source/devices/arm_cmn. Multi-chip systems may link
+more than one CMN together via external CCIX links - in this situation,
+each mesh counts its own events entirely independently, and additional
+PMU devices will be named arm_cmn_{1..n}.
+
+Most events are specified in a format based directly on the TRM
+definitions - "type" selects the respective node type, and "eventid" the
+event number. Some events require an additional occupancy ID, which is
+specified by "occupid".
+
+* Since RN-D nodes do not have any distinct events from RN-I nodes, they
+  are treated as the same type (0xa), and the common event templates are
+  named "rnid_*".
+
+* The cycle counter is treated as a synthetic event belonging to the DTC
+  node ("type" == 0x3, "eventid" is ignored).
+
+* XP events also encode the port and channel in the "eventid" field, to
+  match the underlying pmu_event0_id encoding for the pmu_event_sel
+  register. The event templates are named with prefixes to cover all
+  permutations.
+
+By default each event provides an aggregate count over all nodes of the
+given type. To target a specific node, "bynodeid" must be set to 1 and
+"nodeid" to the appropriate value derived from the CMN configuration
+(as defined in the "Node ID Mapping" section of the TRM).
+
+Watchpoints
+-----------
+
+The PMU can also count watchpoint events to monitor specific flit
+traffic. Watchpoints are treated as a synthetic event type, and like PMU
+events can be global or targeted with a particular XP's "nodeid" value.
+Since the watchpoint direction is otherwise implicit in the underlying
+register selection, separate events are provided for flit uploads and
+downloads.
+
+The flit match value and mask are passed in config1 and config2 ("val"
+and "mask" respectively). "wp_dev_sel", "wp_chn_sel", "wp_grp" and
+"wp_exclusive" are specified per the TRM definitions for dtm_wp_config0.
+Where a watchpoint needs to match fields from both match groups on the
+REQ or SNP channel, it can be specified as two events - one for each
+group - with the same nonzero "combine" value. The count for such a
+pair of combined events will be attributed to the primary match.
+Watchpoint events with a "combine" value of 0 are considered independent
+and will count individually.

Documentation/admin-guide/perf/index.rst

···
    qcom_l2_pmu
    qcom_l3_pmu
    arm-ccn
+   arm-cmn
    xgene-pmu
    arm_dsu_pmu
    thunderx2-pmu

drivers/perf/Kconfig

···
 	  PMU (perf) driver supporting the ARM CCN (Cache Coherent Network)
 	  interconnect.
 
+config ARM_CMN
+	tristate "Arm CMN-600 PMU support"
+	depends on ARM64 || (COMPILE_TEST && 64BIT)
+	help
+	  Support for PMU events monitoring on the Arm CMN-600 Coherent Mesh
+	  Network interconnect.
+
 config ARM_PMU
 	depends on ARM || ARM64
 	bool "ARM PMU framework"

drivers/perf/Makefile

···
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_ARM_CCI_PMU) += arm-cci.o
 obj-$(CONFIG_ARM_CCN) += arm-ccn.o
+obj-$(CONFIG_ARM_CMN) += arm-cmn.o
 obj-$(CONFIG_ARM_DSU_PMU) += arm_dsu_pmu.o
 obj-$(CONFIG_ARM_PMU) += arm_pmu.o arm_pmu_platform.o
 obj-$(CONFIG_ARM_PMU_ACPI) += arm_pmu_acpi.o

drivers/perf/arm-cmn.c

···
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2016-2020 Arm Limited
+// CMN-600 Coherent Mesh Network PMU driver
+
+#include <linux/acpi.h>
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/sort.h>
+
+/* Common register stuff */
+#define CMN_NODE_INFO			0x0000
+#define CMN_NI_NODE_TYPE		GENMASK_ULL(15, 0)
+#define CMN_NI_NODE_ID			GENMASK_ULL(31, 16)
+#define CMN_NI_LOGICAL_ID		GENMASK_ULL(47, 32)
+
+#define CMN_NODEID_DEVID(reg)		((reg) & 3)
+#define CMN_NODEID_PID(reg)		(((reg) >> 2) & 1)
+#define CMN_NODEID_X(reg, bits)		((reg) >> (3 + (bits)))
+#define CMN_NODEID_Y(reg, bits)		(((reg) >> 3) & ((1U << (bits)) - 1))
+
+#define CMN_CHILD_INFO			0x0080
+#define CMN_CI_CHILD_COUNT		GENMASK_ULL(15, 0)
+#define CMN_CI_CHILD_PTR_OFFSET		GENMASK_ULL(31, 16)
+
+#define CMN_CHILD_NODE_ADDR		GENMASK(27,0)
+#define CMN_CHILD_NODE_EXTERNAL		BIT(31)
+
+#define CMN_ADDR_NODE_PTR		GENMASK(27, 14)
+
+#define CMN_NODE_PTR_DEVID(ptr)		(((ptr) >> 2) & 3)
+#define CMN_NODE_PTR_PID(ptr)		((ptr) & 1)
+#define CMN_NODE_PTR_X(ptr, bits)	((ptr) >> (6 + (bits)))
+#define CMN_NODE_PTR_Y(ptr, bits)	(((ptr) >> 6) & ((1U << (bits)) - 1))
+
+#define CMN_MAX_XPS			(8 * 8)
+
+/* The CFG node has one other useful purpose */
+#define CMN_CFGM_PERIPH_ID_2		0x0010
+#define CMN_CFGM_PID2_REVISION		GENMASK(7, 4)
+
+/* PMU registers occupy the 3rd 4KB page of each node's 16KB space */
+#define CMN_PMU_OFFSET			0x2000
+
+/* For most nodes, this is all there is */
+#define CMN_PMU_EVENT_SEL		0x000
+#define CMN_PMU_EVENTn_ID_SHIFT(n)	((n) * 8)
+
+/* DTMs live in the PMU space of XP registers */
+#define CMN_DTM_WPn(n)			(0x1A0 + (n) * 0x18)
+#define CMN_DTM_WPn_CONFIG(n)		(CMN_DTM_WPn(n) + 0x00)
+#define CMN_DTM_WPn_CONFIG_WP_COMBINE	BIT(6)
+#define CMN_DTM_WPn_CONFIG_WP_EXCLUSIVE	BIT(5)
+#define CMN_DTM_WPn_CONFIG_WP_GRP	BIT(4)
+#define CMN_DTM_WPn_CONFIG_WP_CHN_SEL	GENMASK_ULL(3, 1)
+#define CMN_DTM_WPn_CONFIG_WP_DEV_SEL	BIT(0)
+#define CMN_DTM_WPn_VAL(n)		(CMN_DTM_WPn(n) + 0x08)
+#define CMN_DTM_WPn_MASK(n)		(CMN_DTM_WPn(n) + 0x10)
+
+#define CMN_DTM_PMU_CONFIG		0x210
+#define CMN__PMEVCNT0_INPUT_SEL		GENMASK_ULL(37, 32)
+#define CMN__PMEVCNT0_INPUT_SEL_WP	0x00
+#define CMN__PMEVCNT0_INPUT_SEL_XP	0x04
+#define CMN__PMEVCNT0_INPUT_SEL_DEV	0x10
+#define CMN__PMEVCNT0_GLOBAL_NUM	GENMASK_ULL(18, 16)
+#define CMN__PMEVCNTn_GLOBAL_NUM_SHIFT(n)	((n) * 4)
+#define CMN__PMEVCNT_PAIRED(n)		BIT(4 + (n))
+#define CMN__PMEVCNT23_COMBINED		BIT(2)
+#define CMN__PMEVCNT01_COMBINED		BIT(1)
+#define CMN_DTM_PMU_CONFIG_PMU_EN	BIT(0)
+
+#define CMN_DTM_PMEVCNT			0x220
+
+#define CMN_DTM_PMEVCNTSR		0x240
+
+#define CMN_DTM_NUM_COUNTERS		4
+
+/* The DTC node is where the magic happens */
+#define CMN_DT_DTC_CTL			0x0a00
+#define CMN_DT_DTC_CTL_DT_EN		BIT(0)
+
+/* DTC counters are paired in 64-bit registers on a 16-byte stride. Yuck */
+#define _CMN_DT_CNT_REG(n)		((((n) / 2) * 4 + (n) % 2) * 4)
+#define CMN_DT_PMEVCNT(n)		(CMN_PMU_OFFSET + _CMN_DT_CNT_REG(n))
+#define CMN_DT_PMCCNTR			(CMN_PMU_OFFSET + 0x40)
+
+#define CMN_DT_PMEVCNTSR(n)		(CMN_PMU_OFFSET + 0x50 + _CMN_DT_CNT_REG(n))
+#define CMN_DT_PMCCNTRSR		(CMN_PMU_OFFSET + 0x90)
+
+#define CMN_DT_PMCR			(CMN_PMU_OFFSET + 0x100)
+#define CMN_DT_PMCR_PMU_EN		BIT(0)
+#define CMN_DT_PMCR_CNTR_RST		BIT(5)
+#define CMN_DT_PMCR_OVFL_INTR_EN	BIT(6)
+
+#define CMN_DT_PMOVSR			(CMN_PMU_OFFSET + 0x118)
+#define CMN_DT_PMOVSR_CLR		(CMN_PMU_OFFSET + 0x120)
+
+#define CMN_DT_PMSSR			(CMN_PMU_OFFSET + 0x128)
+#define CMN_DT_PMSSR_SS_STATUS(n)	BIT(n)
+
+#define CMN_DT_PMSRR			(CMN_PMU_OFFSET + 0x130)
+#define CMN_DT_PMSRR_SS_REQ		BIT(0)
+
+#define CMN_DT_NUM_COUNTERS		8
+#define CMN_MAX_DTCS			4
+
+/*
+ * Even in the worst case a DTC counter can't wrap in fewer than 2^42 cycles,
+ * so throwing away one bit to make overflow handling easy is no big deal.
+ */
+#define CMN_COUNTER_INIT		0x80000000
+/* Similarly for the 40-bit cycle counter */
+#define CMN_CC_INIT			0x8000000000ULL
+
+
+/* Event attributes */
+#define CMN_CONFIG_TYPE			GENMASK(15, 0)
+#define CMN_CONFIG_EVENTID		GENMASK(23, 16)
+#define CMN_CONFIG_OCCUPID		GENMASK(27, 24)
+#define CMN_CONFIG_BYNODEID		BIT(31)
+#define CMN_CONFIG_NODEID		GENMASK(47, 32)
+
+#define CMN_EVENT_TYPE(event)		FIELD_GET(CMN_CONFIG_TYPE, (event)->attr.config)
+#define CMN_EVENT_EVENTID(event)	FIELD_GET(CMN_CONFIG_EVENTID, (event)->attr.config)
+#define CMN_EVENT_OCCUPID(event)	FIELD_GET(CMN_CONFIG_OCCUPID, (event)->attr.config)
+#define CMN_EVENT_BYNODEID(event)	FIELD_GET(CMN_CONFIG_BYNODEID, (event)->attr.config)
+#define CMN_EVENT_NODEID(event)		FIELD_GET(CMN_CONFIG_NODEID, (event)->attr.config)
+
+#define CMN_CONFIG_WP_COMBINE		GENMASK(27, 24)
+#define CMN_CONFIG_WP_DEV_SEL		BIT(48)
+#define CMN_CONFIG_WP_CHN_SEL		GENMASK(50, 49)
+#define CMN_CONFIG_WP_GRP		BIT(52)
+#define CMN_CONFIG_WP_EXCLUSIVE		BIT(53)
+#define CMN_CONFIG1_WP_VAL		GENMASK(63, 0)
+#define CMN_CONFIG2_WP_MASK		GENMASK(63, 0)
+
+#define CMN_EVENT_WP_COMBINE(event)	FIELD_GET(CMN_CONFIG_WP_COMBINE, (event)->attr.config)
+#define CMN_EVENT_WP_DEV_SEL(event)	FIELD_GET(CMN_CONFIG_WP_DEV_SEL, (event)->attr.config)
+#define CMN_EVENT_WP_CHN_SEL(event)	FIELD_GET(CMN_CONFIG_WP_CHN_SEL, (event)->attr.config)
+#define CMN_EVENT_WP_GRP(event)		FIELD_GET(CMN_CONFIG_WP_GRP, (event)->attr.config)
+#define CMN_EVENT_WP_EXCLUSIVE(event)	FIELD_GET(CMN_CONFIG_WP_EXCLUSIVE, (event)->attr.config)
+#define CMN_EVENT_WP_VAL(event)		FIELD_GET(CMN_CONFIG1_WP_VAL, (event)->attr.config1)
+#define CMN_EVENT_WP_MASK(event)	FIELD_GET(CMN_CONFIG2_WP_MASK, (event)->attr.config2)
+
+/* Made-up event IDs for watchpoint direction */
+#define CMN_WP_UP			0
+#define CMN_WP_DOWN			2
+
+
+/* r0px probably don't exist in silicon, thankfully */
+enum cmn_revision {
+	CMN600_R1P0,
+	CMN600_R1P1,
+	CMN600_R1P2,
+	CMN600_R1P3,
+	CMN600_R2P0,
+	CMN600_R3P0,
+};
+
+enum cmn_node_type {
+	CMN_TYPE_INVALID,
+	CMN_TYPE_DVM,
+	CMN_TYPE_CFG,
+	CMN_TYPE_DTC,
+	CMN_TYPE_HNI,
+	CMN_TYPE_HNF,
+	CMN_TYPE_XP,
+	CMN_TYPE_SBSX,
+	CMN_TYPE_RNI = 0xa,
+	CMN_TYPE_RND = 0xd,
+	CMN_TYPE_RNSAM = 0xf,
+	CMN_TYPE_CXRA = 0x100,
+	CMN_TYPE_CXHA = 0x101,
+	CMN_TYPE_CXLA = 0x102,
+	/* Not a real node type */
+	CMN_TYPE_WP = 0x7770
+};
+
+struct arm_cmn_node {
+	void __iomem *pmu_base;
+	u16 id, logid;
+	enum cmn_node_type type;
+
+	union {
+		/* Device node */
+		struct {
+			int to_xp;
+			/* DN/HN-F/CXHA */
+			unsigned int occupid_val;
+			unsigned int occupid_count;
+		};
+		/* XP */
+		struct {
+			int dtc;
+			u32 pmu_config_low;
+			union {
+				u8 input_sel[4];
+				__le32 pmu_config_high;
+			};
+			s8 wp_event[4];
+		};
+	};
+
+	union {
+		u8 event[4];
+		__le32 event_sel;
+	};
+};
+
+struct arm_cmn_dtc {
+	void __iomem *base;
+	unsigned int irq;
+	int irq_friend;
+	bool cc_active;
+
+	struct perf_event *counters[CMN_DT_NUM_COUNTERS];
+	struct perf_event *cycles;
+};
+
+#define CMN_STATE_DISABLED	BIT(0)
+#define CMN_STATE_TXN		BIT(1)
+
+struct arm_cmn {
+	struct device *dev;
+	void __iomem *base;
+
+	enum cmn_revision rev;
+	u8 mesh_x;
+	u8 mesh_y;
+	u16 num_xps;
+	u16 num_dns;
+	struct arm_cmn_node *xps;
+	struct arm_cmn_node *dns;
+
+	struct arm_cmn_dtc *dtc;
+	unsigned int num_dtcs;
+
+	int cpu;
+	struct hlist_node cpuhp_node;
+
+	unsigned int state;
+	struct pmu pmu;
+};
+
+#define to_cmn(p)	container_of(p, struct arm_cmn, pmu)
+
+static int arm_cmn_hp_state;
+
+struct arm_cmn_hw_event {
+	struct arm_cmn_node *dn;
+	u64 dtm_idx[2];
+	unsigned int dtc_idx;
+	u8 dtcs_used;
+	u8 num_dns;
+};
+
+#define for_each_hw_dn(hw, dn, i) \
+	for (i = 0, dn = hw->dn; i < hw->num_dns; i++, dn++)
+
+static struct arm_cmn_hw_event *to_cmn_hw(struct perf_event *event)
+{
+	BUILD_BUG_ON(sizeof(struct arm_cmn_hw_event) > offsetof(struct hw_perf_event, target));
+	return (struct arm_cmn_hw_event *)&event->hw;
+}
+
+static void arm_cmn_set_index(u64 x[], unsigned int pos, unsigned int val)
+{
+	x[pos / 32] |= (u64)val << ((pos % 32) * 2);
+}
+
+static unsigned int arm_cmn_get_index(u64 x[], unsigned int pos)
+{
+	return (x[pos / 32] >> ((pos % 32) * 2)) & 3;
+}
+
+struct arm_cmn_event_attr {
+	struct device_attribute attr;
+	enum cmn_node_type type;
+	u8 eventid;
+	u8 occupid;
+};
+
+struct arm_cmn_format_attr {
+	struct device_attribute attr;
+	u64 field;
+	int config;
+};
+
+static int arm_cmn_xyidbits(const struct arm_cmn *cmn)
+{
+	return cmn->mesh_x > 4 || cmn->mesh_y > 4 ? 3 : 2;
+}
+
+static void arm_cmn_init_node_to_xp(const struct arm_cmn *cmn,
+				    struct arm_cmn_node *dn)
+{
+	int bits = arm_cmn_xyidbits(cmn);
+	int x = CMN_NODEID_X(dn->id, bits);
+	int y = CMN_NODEID_Y(dn->id, bits);
+	int xp_idx = cmn->mesh_x * y + x;
+
+	dn->to_xp = (cmn->xps + xp_idx) - dn;
+}
+
+static struct arm_cmn_node *arm_cmn_node_to_xp(struct arm_cmn_node *dn)
+{
+	return dn->type == CMN_TYPE_XP ? dn : dn + dn->to_xp;
+}
+
+static struct arm_cmn_node *arm_cmn_node(const struct arm_cmn *cmn,
+					 enum cmn_node_type type)
+{
+	int i;
+
+	for (i = 0; i < cmn->num_dns; i++)
+		if (cmn->dns[i].type == type)
+			return &cmn->dns[i];
+	return NULL;
+}
+
+#define CMN_EVENT_ATTR(_name, _type, _eventid, _occupid)		\
+	(&((struct arm_cmn_event_attr[]) {{				\
+		.attr = __ATTR(_name, 0444, arm_cmn_event_show, NULL),	\
+		.type = _type,						\
+		.eventid = _eventid,					\
+		.occupid = _occupid,					\
+	}})[0].attr.attr)
+
+static bool arm_cmn_is_occup_event(enum cmn_node_type type, unsigned int id)
+{
+	return (type == CMN_TYPE_DVM && id == 0x05) ||
+	       (type == CMN_TYPE_HNF && id == 0x0f);
+}
+
+static ssize_t arm_cmn_event_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct arm_cmn_event_attr *eattr;
+
+	eattr = container_of(attr, typeof(*eattr), attr);
+
+	if (eattr->type == CMN_TYPE_DTC)
+		return snprintf(buf, PAGE_SIZE, "type=0x%x\n", eattr->type);
+
+	if (eattr->type == CMN_TYPE_WP)
+		return snprintf(buf, PAGE_SIZE,
+				"type=0x%x,eventid=0x%x,wp_dev_sel=?,wp_chn_sel=?,wp_grp=?,wp_val=?,wp_mask=?\n",
+				eattr->type, eattr->eventid);
+
+	if (arm_cmn_is_occup_event(eattr->type, eattr->eventid))
+		return snprintf(buf, PAGE_SIZE, "type=0x%x,eventid=0x%x,occupid=0x%x\n",
+				eattr->type, eattr->eventid, eattr->occupid);
+
+	return snprintf(buf, PAGE_SIZE, "type=0x%x,eventid=0x%x\n",
+			eattr->type, eattr->eventid);
+}
+
+static umode_t arm_cmn_event_attr_is_visible(struct kobject *kobj,
+					     struct attribute *attr,
+					     int unused)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct arm_cmn *cmn = to_cmn(dev_get_drvdata(dev));
+	struct arm_cmn_event_attr *eattr;
+	enum cmn_node_type type;
+
+	eattr = container_of(attr, typeof(*eattr), attr.attr);
+	type = eattr->type;
+
+	/* Watchpoints aren't nodes */
+	if (type == CMN_TYPE_WP)
+		type = CMN_TYPE_XP;
+
+	/* Revision-specific differences */
+	if (cmn->rev < CMN600_R1P2) {
+		if (type == CMN_TYPE_HNF && eattr->eventid == 0x1b)
+			return 0;
+	}
+
+	if (!arm_cmn_node(cmn, type))
+		return 0;
+
+	return attr->mode;
+}
+
+#define _CMN_EVENT_DVM(_name, _event, _occup)			\
+	CMN_EVENT_ATTR(dn_##_name, CMN_TYPE_DVM, _event, _occup)
+#define CMN_EVENT_DTC(_name)					\
+	CMN_EVENT_ATTR(dtc_##_name, CMN_TYPE_DTC, 0, 0)
+#define _CMN_EVENT_HNF(_name, _event, _occup)			\
+	CMN_EVENT_ATTR(hnf_##_name, CMN_TYPE_HNF, _event, _occup)
+#define CMN_EVENT_HNI(_name, _event)				\
+	CMN_EVENT_ATTR(hni_##_name, CMN_TYPE_HNI, _event, 0)
+#define __CMN_EVENT_XP(_name, _event)				\
+	CMN_EVENT_ATTR(mxp_##_name, CMN_TYPE_XP, _event, 0)
+#define CMN_EVENT_SBSX(_name, _event)				\
+	CMN_EVENT_ATTR(sbsx_##_name, CMN_TYPE_SBSX, _event, 0)
+#define CMN_EVENT_RNID(_name, _event)				\
+	CMN_EVENT_ATTR(rnid_##_name, CMN_TYPE_RNI, _event, 0)
+
+#define CMN_EVENT_DVM(_name, _event)				\
+	_CMN_EVENT_DVM(_name, _event, 0)
+#define CMN_EVENT_HNF(_name, _event)				\
+	_CMN_EVENT_HNF(_name, _event, 0)
+#define _CMN_EVENT_XP(_name, _event)				\
+	__CMN_EVENT_XP(e_##_name, (_event) | (0 << 2)),		\
+	__CMN_EVENT_XP(w_##_name, (_event) | (1 << 2)),		\
+	__CMN_EVENT_XP(n_##_name, (_event) | (2 << 2)),		\
+	__CMN_EVENT_XP(s_##_name, (_event) | (3 << 2)),		\
+	__CMN_EVENT_XP(p0_##_name, (_event) | (4 << 2)),	\
+	__CMN_EVENT_XP(p1_##_name, (_event) | (5 << 2))
+
+/* Good thing there are only 3 fundamental XP events... */
+#define CMN_EVENT_XP(_name, _event)				\
+	_CMN_EVENT_XP(req_##_name, (_event) | (0 << 5)),	\
+	_CMN_EVENT_XP(rsp_##_name, (_event) | (1 << 5)),	\
+	_CMN_EVENT_XP(snp_##_name, (_event) | (2 << 5)),	\
+	_CMN_EVENT_XP(dat_##_name, (_event) | (3 << 5))
+
+
+static struct attribute *arm_cmn_event_attrs[] = {
+	CMN_EVENT_DTC(cycles),
+
+	/*
+	 * DVM node events conflict with HN-I events in the equivalent PMU
+	 * slot, but our lazy short-cut of using the DTM counter index for
+	 * the PMU index as well happens to avoid that by construction.
+	 */
+	CMN_EVENT_DVM(rxreq_dvmop,	0x01),
+	CMN_EVENT_DVM(rxreq_dvmsync,	0x02),
+	CMN_EVENT_DVM(rxreq_dvmop_vmid_filtered, 0x03),
+	CMN_EVENT_DVM(rxreq_retried,	0x04),
+	_CMN_EVENT_DVM(rxreq_trk_occupancy_all, 0x05, 0),
+	_CMN_EVENT_DVM(rxreq_trk_occupancy_dvmop, 0x05, 1),
+	_CMN_EVENT_DVM(rxreq_trk_occupancy_dvmsync, 0x05, 2),
+
+	CMN_EVENT_HNF(cache_miss,	0x01),
+	CMN_EVENT_HNF(slc_sf_cache_access, 0x02),
+	CMN_EVENT_HNF(cache_fill,	0x03),
+	CMN_EVENT_HNF(pocq_retry,	0x04),
+	CMN_EVENT_HNF(pocq_reqs_recvd,	0x05),
+	CMN_EVENT_HNF(sf_hit,		0x06),
+	CMN_EVENT_HNF(sf_evictions,	0x07),
+	CMN_EVENT_HNF(dir_snoops_sent,	0x08),
+	CMN_EVENT_HNF(brd_snoops_sent,	0x09),
+	CMN_EVENT_HNF(slc_eviction,	0x0a),
+	CMN_EVENT_HNF(slc_fill_invalid_way, 0x0b),
+	CMN_EVENT_HNF(mc_retries,	0x0c),
+	CMN_EVENT_HNF(mc_reqs,		0x0d),
+	CMN_EVENT_HNF(qos_hh_retry,	0x0e),
+	_CMN_EVENT_HNF(qos_pocq_occupancy_all, 0x0f, 0),
+	_CMN_EVENT_HNF(qos_pocq_occupancy_read, 0x0f, 1),
+	_CMN_EVENT_HNF(qos_pocq_occupancy_write, 0x0f, 2),
+	_CMN_EVENT_HNF(qos_pocq_occupancy_atomic, 0x0f, 3),
+	_CMN_EVENT_HNF(qos_pocq_occupancy_stash, 0x0f, 4),
+	CMN_EVENT_HNF(pocq_addrhaz,	0x10),
+	CMN_EVENT_HNF(pocq_atomic_addrhaz, 0x11),
+	CMN_EVENT_HNF(ld_st_swp_adq_full, 0x12),
+	CMN_EVENT_HNF(cmp_adq_full,	0x13),
+	CMN_EVENT_HNF(txdat_stall,	0x14),
+	CMN_EVENT_HNF(txrsp_stall,	0x15),
+	CMN_EVENT_HNF(seq_full,		0x16),
+	CMN_EVENT_HNF(seq_hit,		0x17),
+	CMN_EVENT_HNF(snp_sent,		0x18),
+	CMN_EVENT_HNF(sfbi_dir_snp_sent, 0x19),
+	CMN_EVENT_HNF(sfbi_brd_snp_sent, 0x1a),
+	CMN_EVENT_HNF(snp_sent_untrk,	0x1b),
+	CMN_EVENT_HNF(intv_dirty,	0x1c),
+	CMN_EVENT_HNF(stash_snp_sent,	0x1d),
+	CMN_EVENT_HNF(stash_data_pull,	0x1e),
+	CMN_EVENT_HNF(snp_fwded,	0x1f),
+
+	CMN_EVENT_HNI(rrt_rd_occ_cnt_ovfl, 0x20),
+	CMN_EVENT_HNI(rrt_wr_occ_cnt_ovfl, 0x21),
+	CMN_EVENT_HNI(rdt_rd_occ_cnt_ovfl, 0x22),
+	CMN_EVENT_HNI(rdt_wr_occ_cnt_ovfl, 0x23),
+	CMN_EVENT_HNI(wdb_occ_cnt_ovfl,	0x24),
+	CMN_EVENT_HNI(rrt_rd_alloc,	0x25),
+	CMN_EVENT_HNI(rrt_wr_alloc,	0x26),
+	CMN_EVENT_HNI(rdt_rd_alloc,	0x27),
+	CMN_EVENT_HNI(rdt_wr_alloc,	0x28),
+	CMN_EVENT_HNI(wdb_alloc,	0x29),
+	CMN_EVENT_HNI(txrsp_retryack,	0x2a),
+	CMN_EVENT_HNI(arvalid_no_arready, 0x2b),
+	CMN_EVENT_HNI(arready_no_arvalid, 0x2c),
+	CMN_EVENT_HNI(awvalid_no_awready, 0x2d),
+	CMN_EVENT_HNI(awready_no_awvalid, 0x2e),
+	CMN_EVENT_HNI(wvalid_no_wready,	0x2f),
+	CMN_EVENT_HNI(txdat_stall,	0x30),
+	CMN_EVENT_HNI(nonpcie_serialization, 0x31),
+	CMN_EVENT_HNI(pcie_serialization, 0x32),
+
+	CMN_EVENT_XP(txflit_valid,	0x01),
+	CMN_EVENT_XP(txflit_stall,	0x02),
+	CMN_EVENT_XP(partial_dat_flit,	0x03),
+	/* We treat watchpoints as a special made-up class of XP events */
+	CMN_EVENT_ATTR(watchpoint_up, CMN_TYPE_WP, 0, 0),
+	CMN_EVENT_ATTR(watchpoint_down, CMN_TYPE_WP, 2, 0),
+
+	CMN_EVENT_SBSX(rd_req,		0x01),
+	CMN_EVENT_SBSX(wr_req,		0x02),
+	CMN_EVENT_SBSX(cmo_req,		0x03),
+	CMN_EVENT_SBSX(txrsp_retryack,	0x04),
+	CMN_EVENT_SBSX(txdat_flitv,	0x05),
+	CMN_EVENT_SBSX(txrsp_flitv,	0x06),
+	CMN_EVENT_SBSX(rd_req_trkr_occ_cnt_ovfl, 0x11),
+	CMN_EVENT_SBSX(wr_req_trkr_occ_cnt_ovfl, 0x12),
+	CMN_EVENT_SBSX(cmo_req_trkr_occ_cnt_ovfl, 0x13),
+	CMN_EVENT_SBSX(wdb_occ_cnt_ovfl, 0x14),
+	CMN_EVENT_SBSX(rd_axi_trkr_occ_cnt_ovfl, 0x15),
+	CMN_EVENT_SBSX(cmo_axi_trkr_occ_cnt_ovfl, 0x16),
+	CMN_EVENT_SBSX(arvalid_no_arready, 0x21),
+	CMN_EVENT_SBSX(awvalid_no_awready, 0x22),
+	CMN_EVENT_SBSX(wvalid_no_wready, 0x23),
+	CMN_EVENT_SBSX(txdat_stall,	0x24),
+	CMN_EVENT_SBSX(txrsp_stall,	0x25),
+
+	CMN_EVENT_RNID(s0_rdata_beats,	0x01),
+	CMN_EVENT_RNID(s1_rdata_beats,	0x02),
+	CMN_EVENT_RNID(s2_rdata_beats,	0x03),
+	CMN_EVENT_RNID(rxdat_flits,	0x04),
+	CMN_EVENT_RNID(txdat_flits,	0x05),
+	CMN_EVENT_RNID(txreq_flits_total, 0x06),
+	CMN_EVENT_RNID(txreq_flits_retried, 0x07),
+	CMN_EVENT_RNID(rrt_occ_ovfl,	0x08),
+	CMN_EVENT_RNID(wrt_occ_ovfl,	0x09),
+	CMN_EVENT_RNID(txreq_flits_replayed, 0x0a),
+	CMN_EVENT_RNID(wrcancel_sent,	0x0b),
+	CMN_EVENT_RNID(s0_wdata_beats,	0x0c),
+	CMN_EVENT_RNID(s1_wdata_beats,	0x0d),
+	CMN_EVENT_RNID(s2_wdata_beats,	0x0e),
+	CMN_EVENT_RNID(rrt_alloc,	0x0f),
+	CMN_EVENT_RNID(wrt_alloc,	0x10),
+	CMN_EVENT_RNID(rdb_unord,	0x11),
+	CMN_EVENT_RNID(rdb_replay,	0x12),
+	CMN_EVENT_RNID(rdb_hybrid,	0x13),
+	CMN_EVENT_RNID(rdb_ord,		0x14),
+
+	NULL
+};
+
+static const struct attribute_group arm_cmn_event_attrs_group = {
+	.name = "events",
+	.attrs = arm_cmn_event_attrs,
+	.is_visible = arm_cmn_event_attr_is_visible,
+};
+
+static ssize_t arm_cmn_format_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct arm_cmn_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 _CMN_FORMAT_ATTR(_name, _cfg, _fld)				\
+	(&((struct arm_cmn_format_attr[]) {{				\
+		.attr = __ATTR(_name, 0444, arm_cmn_format_show, NULL),	\
+		.config = _cfg,						\
+		.field = _fld,						\
+	}})[0].attr.attr)
+#define CMN_FORMAT_ATTR(_name, _fld)	_CMN_FORMAT_ATTR(_name, 0, _fld)
+
+static struct attribute *arm_cmn_format_attrs[] = {
+	CMN_FORMAT_ATTR(type, CMN_CONFIG_TYPE),
+	CMN_FORMAT_ATTR(eventid, CMN_CONFIG_EVENTID),
+	CMN_FORMAT_ATTR(occupid, CMN_CONFIG_OCCUPID),
+	CMN_FORMAT_ATTR(bynodeid, CMN_CONFIG_BYNODEID),
+	CMN_FORMAT_ATTR(nodeid, CMN_CONFIG_NODEID),
+
+	CMN_FORMAT_ATTR(wp_dev_sel, CMN_CONFIG_WP_DEV_SEL),
+	CMN_FORMAT_ATTR(wp_chn_sel, CMN_CONFIG_WP_CHN_SEL),
+	CMN_FORMAT_ATTR(wp_grp, CMN_CONFIG_WP_GRP),
+	CMN_FORMAT_ATTR(wp_exclusive, CMN_CONFIG_WP_EXCLUSIVE),
+	CMN_FORMAT_ATTR(wp_combine, CMN_CONFIG_WP_COMBINE),
+
+	_CMN_FORMAT_ATTR(wp_val, 1, CMN_CONFIG1_WP_VAL),
+	_CMN_FORMAT_ATTR(wp_mask, 2, CMN_CONFIG2_WP_MASK),
+
+	NULL
+};
+
+static const struct attribute_group arm_cmn_format_attrs_group = {
+	.name = "format",
+	.attrs = arm_cmn_format_attrs,
+};
+
+static ssize_t arm_cmn_cpumask_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct arm_cmn *cmn = to_cmn(dev_get_drvdata(dev));
+
+	return cpumap_print_to_pagebuf(true, buf, cpumask_of(cmn->cpu));
+}
+
+static struct device_attribute arm_cmn_cpumask_attr =
+		__ATTR(cpumask, 0444, arm_cmn_cpumask_show, NULL);
+
+static struct attribute *arm_cmn_cpumask_attrs[] = {
+	&arm_cmn_cpumask_attr.attr,
+	NULL,
+};
+
+static struct attribute_group arm_cmn_cpumask_attr_group = {
+	.attrs = arm_cmn_cpumask_attrs,
+};
+
+static const struct attribute_group *arm_cmn_attr_groups[] = {
+	&arm_cmn_event_attrs_group,
+	&arm_cmn_format_attrs_group,
+	&arm_cmn_cpumask_attr_group,
+	NULL
+};
+
+static int arm_cmn_wp_idx(struct perf_event *event)
+{
+	return CMN_EVENT_EVENTID(event) + CMN_EVENT_WP_GRP(event);
+}
+
+static u32 arm_cmn_wp_config(struct perf_event *event)
+{
+	u32 config;
+	u32 dev = CMN_EVENT_WP_DEV_SEL(event);
+	u32 chn = CMN_EVENT_WP_CHN_SEL(event);
+	u32 grp = CMN_EVENT_WP_GRP(event);
+	u32 exc = CMN_EVENT_WP_EXCLUSIVE(event);
+	u32 combine = CMN_EVENT_WP_COMBINE(event);
+
+	config = FIELD_PREP(CMN_DTM_WPn_CONFIG_WP_DEV_SEL, dev) |
+		 FIELD_PREP(CMN_DTM_WPn_CONFIG_WP_CHN_SEL, chn) |
+		 FIELD_PREP(CMN_DTM_WPn_CONFIG_WP_GRP, grp) |
+		 FIELD_PREP(CMN_DTM_WPn_CONFIG_WP_EXCLUSIVE, exc);
+	if (combine && !grp)
+		config |= CMN_DTM_WPn_CONFIG_WP_COMBINE;
+
+	return config;
+}
+
+static void arm_cmn_set_state(struct arm_cmn *cmn, u32 state)
+{
+	if (!cmn->state)
+		writel_relaxed(0, cmn->dtc[0].base + CMN_DT_PMCR);
+	cmn->state |= state;
+}
+
+static void arm_cmn_clear_state(struct arm_cmn *cmn, u32 state)
+{
+	cmn->state &= ~state;
+	if (!cmn->state)
+		writel_relaxed(CMN_DT_PMCR_PMU_EN | CMN_DT_PMCR_OVFL_INTR_EN,
+			       cmn->dtc[0].base + CMN_DT_PMCR);
+}
+
+static void arm_cmn_pmu_enable(struct pmu *pmu)
+{
+	arm_cmn_clear_state(to_cmn(pmu), CMN_STATE_DISABLED);
+}
+
+static void arm_cmn_pmu_disable(struct pmu *pmu)
+{
+	arm_cmn_set_state(to_cmn(pmu), CMN_STATE_DISABLED);
+}
+
+static u64 arm_cmn_read_dtm(struct arm_cmn *cmn, struct arm_cmn_hw_event *hw,
+			    bool snapshot)
+{
+	struct arm_cmn_node *dn;
+	unsigned int i, offset;
+	u64 count = 0;
+
+	offset = snapshot ? CMN_DTM_PMEVCNTSR : CMN_DTM_PMEVCNT;
+	for_each_hw_dn(hw, dn, i) {
+		struct arm_cmn_node *xp = arm_cmn_node_to_xp(dn);
+		int dtm_idx = arm_cmn_get_index(hw->dtm_idx, i);
+		u64 reg = readq_relaxed(xp->pmu_base + offset);
+		u16 dtm_count = reg >> (dtm_idx * 16);
+
+		count += dtm_count;
+	}
+	return count;
+}
+
+static u64 arm_cmn_read_cc(struct arm_cmn_dtc *dtc)
+{
+	u64 val = readq_relaxed(dtc->base + CMN_DT_PMCCNTR);
+
+	writeq_relaxed(CMN_CC_INIT, dtc->base + CMN_DT_PMCCNTR);
+	return (val - CMN_CC_INIT) & ((CMN_CC_INIT << 1) - 1);
+}
+
+static u32 arm_cmn_read_counter(struct arm_cmn_dtc *dtc, int idx)
+{
+	u32 val, pmevcnt = CMN_DT_PMEVCNT(idx);
+
+	val = readl_relaxed(dtc->base + pmevcnt);
+	writel_relaxed(CMN_COUNTER_INIT, dtc->base + pmevcnt);
+	return val - CMN_COUNTER_INIT;
+}
+
+static void arm_cmn_init_counter(struct perf_event *event)
+{
+	struct arm_cmn *cmn = to_cmn(event->pmu);
+	struct arm_cmn_hw_event *hw = to_cmn_hw(event);
+	unsigned int i, pmevcnt = CMN_DT_PMEVCNT(hw->dtc_idx);
+	u64 count;
+
+	for (i = 0; hw->dtcs_used & (1U << i); i++) {
+		writel_relaxed(CMN_COUNTER_INIT, cmn->dtc[i].base + pmevcnt);
+		cmn->dtc[i].counters[hw->dtc_idx] = event;
+	}
+
+	count = arm_cmn_read_dtm(cmn, hw, false);
+	local64_set(&event->hw.prev_count, count);
+}
+
+static void arm_cmn_event_read(struct perf_event *event)
+{
+	struct arm_cmn *cmn = to_cmn(event->pmu);
+	struct arm_cmn_hw_event *hw = to_cmn_hw(event);
+	u64 delta, new, prev;
+	unsigned long flags;
+	unsigned int i;
+
+	if (hw->dtc_idx == CMN_DT_NUM_COUNTERS) {
+		i = __ffs(hw->dtcs_used);
+		delta = arm_cmn_read_cc(cmn->dtc + i);
+		local64_add(delta, &event->count);
+		return;
+	}
+	new = arm_cmn_read_dtm(cmn, hw, false);
+	prev = local64_xchg(&event->hw.prev_count, new);
+
+	delta = new - prev;
+
+	local_irq_save(flags);
+	for (i = 0; hw->dtcs_used & (1U << i); i++) {
+		new = arm_cmn_read_counter(cmn->dtc + i, hw->dtc_idx);
+		delta += new << 16;
+	}
+	local_irq_restore(flags);
+	local64_add(delta, &event->count);
+}
+
+static void arm_cmn_event_start(struct perf_event *event, int flags)
+{
+	struct arm_cmn *cmn = to_cmn(event->pmu);
+	struct arm_cmn_hw_event *hw = to_cmn_hw(event);
+	struct arm_cmn_node *dn;
+	enum cmn_node_type type = CMN_EVENT_TYPE(event);
+	int i;
+
+	if (type == CMN_TYPE_DTC) {
+		i = __ffs(hw->dtcs_used);
+		writeq_relaxed(CMN_CC_INIT, cmn->dtc[i].base + CMN_DT_PMCCNTR);
+		cmn->dtc[i].cc_active = true;
+	} else if (type == CMN_TYPE_WP) {
+		int wp_idx = arm_cmn_wp_idx(event);
+		u64 val = CMN_EVENT_WP_VAL(event);
+		u64 mask = CMN_EVENT_WP_MASK(event);
+
+		for_each_hw_dn(hw, dn, i) {
+			writeq_relaxed(val, dn->pmu_base + CMN_DTM_WPn_VAL(wp_idx));
+			writeq_relaxed(mask, dn->pmu_base + CMN_DTM_WPn_MASK(wp_idx));
+		}
+	} else for_each_hw_dn(hw, dn, i) {
+		int dtm_idx = arm_cmn_get_index(hw->dtm_idx, i);
+
+		dn->event[dtm_idx] = CMN_EVENT_EVENTID(event);
+		writel_relaxed(le32_to_cpu(dn->event_sel), dn->pmu_base + CMN_PMU_EVENT_SEL);
+	}
+}
+
+static void arm_cmn_event_stop(struct perf_event *event, int flags)
+{
+	struct arm_cmn *cmn = to_cmn(event->pmu);
+	struct arm_cmn_hw_event *hw = to_cmn_hw(event);
+	struct arm_cmn_node *dn;
+	enum cmn_node_type type = CMN_EVENT_TYPE(event);
+	int i;
+
+	if (type == CMN_TYPE_DTC) {
+		i = __ffs(hw->dtcs_used);
+		cmn->dtc[i].cc_active = false;
+	} else if (type == CMN_TYPE_WP) {
+		int wp_idx = arm_cmn_wp_idx(event);
+
+		for_each_hw_dn(hw, dn, i) {
+			writeq_relaxed(0, dn->pmu_base + CMN_DTM_WPn_MASK(wp_idx));
+			writeq_relaxed(~0ULL, dn->pmu_base + CMN_DTM_WPn_VAL(wp_idx));
+		}
+	} else for_each_hw_dn(hw, dn, i) {
+		int dtm_idx = arm_cmn_get_index(hw->dtm_idx, i);
+
+		dn->event[dtm_idx] = 0;
+		writel_relaxed(le32_to_cpu(dn->event_sel), dn->pmu_base + CMN_PMU_EVENT_SEL);
+	}
+
+	arm_cmn_event_read(event);
+}
+
+struct arm_cmn_val {
+	u8 dtm_count[CMN_MAX_XPS];
+	u8 occupid[CMN_MAX_XPS];
+	u8 wp[CMN_MAX_XPS][4];
+	int dtc_count;
+	bool cycles;
+};
+
+static void arm_cmn_val_add_event(struct arm_cmn_val *val, struct perf_event *event)
+{
+	struct arm_cmn_hw_event *hw = to_cmn_hw(event);
+	struct arm_cmn_node *dn;
+	enum cmn_node_type type;
+	int i;
+	u8 occupid;
+
+	if (is_software_event(event))
+		return;
+
+	type = CMN_EVENT_TYPE(event);
+	if (type == CMN_TYPE_DTC) {
+		val->cycles = true;
+		return;
+	}
+
+	val->dtc_count++;
+	if (arm_cmn_is_occup_event(type, CMN_EVENT_EVENTID(event)))
+		occupid = CMN_EVENT_OCCUPID(event) + 1;
+	else
+		occupid = 0;
+
+	for_each_hw_dn(hw, dn, i) {
+		int wp_idx, xp = arm_cmn_node_to_xp(dn)->logid;
+
+		val->dtm_count[xp]++;
+		val->occupid[xp] = occupid;
+
+		if (type != CMN_TYPE_WP)
+			continue;
+
+		wp_idx = arm_cmn_wp_idx(event);
+		val->wp[xp][wp_idx] = CMN_EVENT_WP_COMBINE(event) + 1;
+	}
+}
+
+static int arm_cmn_validate_group(struct perf_event *event)
+{
+	struct arm_cmn_hw_event *hw = to_cmn_hw(event);
+	struct arm_cmn_node *dn;
+	struct perf_event *sibling, *leader = event->group_leader;
+	enum cmn_node_type type;
+	struct arm_cmn_val val;
+	int i;
+	u8 occupid;
+
+	if (leader == event)
+		return 0;
+
+	if (event->pmu != leader->pmu && !is_software_event(leader))
+		return -EINVAL;
+
+	memset(&val, 0, sizeof(val));
+
+	arm_cmn_val_add_event(&val, leader);
+	for_each_sibling_event(sibling, leader)
+		arm_cmn_val_add_event(&val, sibling);
+
+	type = CMN_EVENT_TYPE(event);
+	if (type == CMN_TYPE_DTC)
+		return val.cycles ? -EINVAL : 0;
+
+	if (val.dtc_count == CMN_DT_NUM_COUNTERS)
+		return -EINVAL;
+
+	if (arm_cmn_is_occup_event(type, CMN_EVENT_EVENTID(event)))
+		occupid = CMN_EVENT_OCCUPID(event) + 1;
+	else
+		occupid = 0;
+
+	for_each_hw_dn(hw, dn, i) {
+		int wp_idx, wp_cmb, xp = arm_cmn_node_to_xp(dn)->logid;
+
+		if (val.dtm_count[xp] == CMN_DTM_NUM_COUNTERS)
+			return -EINVAL;
+
+		if (occupid && val.occupid[xp] && occupid != val.occupid[xp])
+			return -EINVAL;
+
+		if (type != CMN_TYPE_WP)
+			continue;
+
+		wp_idx = arm_cmn_wp_idx(event);
+		if (val.wp[xp][wp_idx])
+			return -EINVAL;
+
+		wp_cmb = val.wp[xp][wp_idx ^ 1];
+		if (wp_cmb && wp_cmb != CMN_EVENT_WP_COMBINE(event) + 1)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int arm_cmn_event_init(struct perf_event *event)
+{
+	struct arm_cmn *cmn = to_cmn(event->pmu);
+	struct arm_cmn_hw_event *hw = to_cmn_hw(event);
+	enum cmn_node_type type;
+	unsigned int i;
+	bool bynodeid;
+	u16 nodeid, eventid;
+
+	if (event->attr.type != event->pmu->type)
+		return -ENOENT;
+
+	if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
+		return -EINVAL;
+
+	event->cpu = cmn->cpu;
+	if (event->cpu < 0)
+		return -EINVAL;
+
+	type = CMN_EVENT_TYPE(event);
+	/* DTC events (i.e. cycles) already have everything they need */
+	if (type == CMN_TYPE_DTC)
+		return 0;
+
+	/* For watchpoints we need the actual XP node here */
+	if (type == CMN_TYPE_WP) {
+		type = CMN_TYPE_XP;
+		/* ...and we need a "real" direction */
+		eventid = CMN_EVENT_EVENTID(event);
+		if (eventid != CMN_WP_UP && eventid != CMN_WP_DOWN)
+			return -EINVAL;
+	}
+
+	bynodeid = CMN_EVENT_BYNODEID(event);
+	nodeid = CMN_EVENT_NODEID(event);
+
+	hw->dn = arm_cmn_node(cmn, type);
+	for (i = hw->dn - cmn->dns; i < cmn->num_dns && cmn->dns[i].type == type; i++) {
+		if (!bynodeid) {
+			hw->num_dns++;
+		} else if (cmn->dns[i].id != nodeid) {
+			hw->dn++;
+		} else {
+			hw->num_dns = 1;
+			break;
+		}
+	}
+
+	if (!hw->num_dns) {
+		int bits = arm_cmn_xyidbits(cmn);
+
+		dev_dbg(cmn->dev, "invalid node 0x%x (%d,%d,%d,%d) type 0x%x\n",
+			nodeid, CMN_NODEID_X(nodeid, bits), CMN_NODEID_Y(nodeid, bits),
+			CMN_NODEID_PID(nodeid), CMN_NODEID_DEVID(nodeid), type);
+		return -EINVAL;
+	}
+	/*
+	 * By assuming events count in all DTC domains, we cunningly avoid
+	 * needing to know anything about how XPs are assigned to domains.
+	 */
+	hw->dtcs_used = (1U << cmn->num_dtcs) - 1;
+
+	return arm_cmn_validate_group(event);
+}
+
+static void arm_cmn_event_clear(struct arm_cmn *cmn, struct perf_event *event,
+				int i)
+{
+	struct arm_cmn_hw_event *hw = to_cmn_hw(event);
+	enum cmn_node_type type = CMN_EVENT_TYPE(event);
+
+	while (i--) {
+		struct arm_cmn_node *xp = arm_cmn_node_to_xp(hw->dn + i);
+		unsigned int dtm_idx = arm_cmn_get_index(hw->dtm_idx, i);
+
+		if (type == CMN_TYPE_WP)
+			hw->dn[i].wp_event[arm_cmn_wp_idx(event)] = -1;
+
+		if (arm_cmn_is_occup_event(type, CMN_EVENT_EVENTID(event)))
+			hw->dn[i].occupid_count--;
+
+		xp->pmu_config_low &= ~CMN__PMEVCNT_PAIRED(dtm_idx);
+		writel_relaxed(xp->pmu_config_low, xp->pmu_base + CMN_DTM_PMU_CONFIG);
+	}
+	memset(hw->dtm_idx, 0, sizeof(hw->dtm_idx));
+
+	for (i = 0; hw->dtcs_used & (1U << i); i++)
+		cmn->dtc[i].counters[hw->dtc_idx] = NULL;
+}
+
+static int arm_cmn_event_add(struct perf_event *event, int flags)
+{
+	struct arm_cmn *cmn = to_cmn(event->pmu);
+	struct arm_cmn_hw_event *hw = to_cmn_hw(event);
+	struct arm_cmn_dtc *dtc = &cmn->dtc[0];
+	struct arm_cmn_node *dn;
+	enum cmn_node_type type = CMN_EVENT_TYPE(event);
+	unsigned int i, dtc_idx, input_sel;
+
+	if (type == CMN_TYPE_DTC) {
+		i = 0;
+		while (cmn->dtc[i].cycles)
+			if (++i == cmn->num_dtcs)
+				return -ENOSPC;
+
+		cmn->dtc[i].cycles = event;
+		hw->dtc_idx = CMN_DT_NUM_COUNTERS;
+		hw->dtcs_used = 1U << i;
+
+		if (flags & PERF_EF_START)
+			arm_cmn_event_start(event, 0);
+		return 0;
+	}
+
+	/* Grab a free global counter first... */
+	dtc_idx = 0;
+	while (dtc->counters[dtc_idx])
+		if (++dtc_idx == CMN_DT_NUM_COUNTERS)
+			return -ENOSPC;
+
+	hw->dtc_idx = dtc_idx;
+
+	/* ...then the local counters to feed it. */
+	for_each_hw_dn(hw, dn, i) {
+		struct arm_cmn_node *xp = arm_cmn_node_to_xp(dn);
+		unsigned int dtm_idx, shift;
+		u64 reg;
+
+		dtm_idx = 0;
+		while (xp->pmu_config_low & CMN__PMEVCNT_PAIRED(dtm_idx))
+			if (++dtm_idx == CMN_DTM_NUM_COUNTERS)
+				goto free_dtms;
+
+		if (type == CMN_TYPE_XP) {
+			input_sel = CMN__PMEVCNT0_INPUT_SEL_XP + dtm_idx;
+		} else if (type == CMN_TYPE_WP) {
+			int tmp, wp_idx = arm_cmn_wp_idx(event);
+			u32 cfg = arm_cmn_wp_config(event);
+
+			if (dn->wp_event[wp_idx] >= 0)
+				goto free_dtms;
+
+			tmp = dn->wp_event[wp_idx ^ 1];
+			if (tmp >= 0 && CMN_EVENT_WP_COMBINE(event) !=
+					CMN_EVENT_WP_COMBINE(dtc->counters[tmp]))
+				goto free_dtms;
+
+			input_sel = CMN__PMEVCNT0_INPUT_SEL_WP + wp_idx;
+			dn->wp_event[wp_idx] = dtc_idx;
+			writel_relaxed(cfg, dn->pmu_base + CMN_DTM_WPn_CONFIG(wp_idx));
+		} else {
+			unsigned int port = CMN_NODEID_PID(dn->id);
+			unsigned int dev = CMN_NODEID_DEVID(dn->id);
+
+			input_sel = CMN__PMEVCNT0_INPUT_SEL_DEV + dtm_idx +
+				    (port << 4) + (dev << 2);
+
+			if (arm_cmn_is_occup_event(type, CMN_EVENT_EVENTID(event))) {
+				int occupid = CMN_EVENT_OCCUPID(event);
+
+				if (dn->occupid_count == 0) {
+					dn->occupid_val = occupid;
+					writel_relaxed(occupid,
+						       dn->pmu_base + CMN_PMU_EVENT_SEL + 4);
+				} else if (dn->occupid_val != occupid) {
+					goto free_dtms;
+				}
+				dn->occupid_count++;
+			}
+		}
+
+		arm_cmn_set_index(hw->dtm_idx, i, dtm_idx);
+
+		xp->input_sel[dtm_idx] = input_sel;
+		shift = CMN__PMEVCNTn_GLOBAL_NUM_SHIFT(dtm_idx);
+		xp->pmu_config_low &= ~(CMN__PMEVCNT0_GLOBAL_NUM << shift);
+		xp->pmu_config_low |= FIELD_PREP(CMN__PMEVCNT0_GLOBAL_NUM, dtc_idx) << shift;
+		xp->pmu_config_low |= CMN__PMEVCNT_PAIRED(dtm_idx);
+		reg = (u64)le32_to_cpu(xp->pmu_config_high) << 32 | xp->pmu_config_low;
+		writeq_relaxed(reg, xp->pmu_base + CMN_DTM_PMU_CONFIG);
+	}
+
+	/* Go go go! */
+	arm_cmn_init_counter(event);
+
+	if (flags & PERF_EF_START)
+		arm_cmn_event_start(event, 0);
+
+	return 0;
+
+free_dtms:
+	arm_cmn_event_clear(cmn, event, i);
+	return -ENOSPC;
+}
+
+static void arm_cmn_event_del(struct perf_event *event, int flags)
+{
+	struct arm_cmn *cmn = to_cmn(event->pmu);
+	struct arm_cmn_hw_event *hw = to_cmn_hw(event);
+	enum cmn_node_type type = CMN_EVENT_TYPE(event);
+
+	arm_cmn_event_stop(event, PERF_EF_UPDATE);
+
+	if (type == CMN_TYPE_DTC)
+		cmn->dtc[__ffs(hw->dtcs_used)].cycles = NULL;
+	else
+		arm_cmn_event_clear(cmn, event, hw->num_dns);
+}
+
+/*
+ * We stop the PMU for both add and read, to avoid skew across DTM counters.
+ * In theory we could use snapshots to read without stopping, but then it
+ * becomes a lot trickier to deal with overlow and racing against interrupts,
+ * plus it seems they don't work properly on some hardware anyway :(
+ */
+static void arm_cmn_start_txn(struct pmu *pmu, unsigned int flags)
+{
+	arm_cmn_set_state(to_cmn(pmu), CMN_STATE_TXN);
+}
+
+static void arm_cmn_end_txn(struct pmu *pmu)
+{
+	arm_cmn_clear_state(to_cmn(pmu), CMN_STATE_TXN);
+}
+
+static int arm_cmn_commit_txn(struct pmu *pmu)
+{
+	arm_cmn_end_txn(pmu);
+	return 0;
+}
+
+static int arm_cmn_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
+{
+	struct arm_cmn *cmn;
+	unsigned int target;
+
+	cmn = hlist_entry_safe(node, struct arm_cmn, cpuhp_node);
+	if (cpu != cmn->cpu)
+		return 0;
+
+	target = cpumask_any_but(cpu_online_mask, cpu);
+	if (target >= nr_cpu_ids)
+		return 0;
+
+	perf_pmu_migrate_context(&cmn->pmu, cpu, target);
+	cmn->cpu = target;
+	return 0;
+}
+
+static irqreturn_t arm_cmn_handle_irq(int irq, void *dev_id)
+{
+	struct arm_cmn_dtc *dtc = dev_id;
+	irqreturn_t ret = IRQ_NONE;
+
+	for (;;) {
+		u32 status = readl_relaxed(dtc->base + CMN_DT_PMOVSR);
+		u64 delta;
+		int i;
+
+		for (i = 0; i < CMN_DTM_NUM_COUNTERS; i++) {
+			if (status & (1U << i)) {
+				ret = IRQ_HANDLED;
+				if (WARN_ON(!dtc->counters[i]))
+					continue;
+				delta = (u64)arm_cmn_read_counter(dtc, i) << 16;
+				local64_add(delta, &dtc->counters[i]->count);
+			}
+		}
+
+		if (status & (1U << CMN_DT_NUM_COUNTERS)) {
+			ret = IRQ_HANDLED;
+			if (dtc->cc_active && !WARN_ON(!dtc->cycles)) {
+				delta = arm_cmn_read_cc(dtc);
+				local64_add(delta, &dtc->cycles->count);
+			}
+		}
+
+		writel_relaxed(status, dtc->base + CMN_DT_PMOVSR_CLR);
+
+		if (!dtc->irq_friend)
+			return ret;
+		dtc += dtc->irq_friend;
+	}
+}
+
+/* We can reasonably accommodate DTCs of the same CMN sharing IRQs */
+static int arm_cmn_init_irqs(struct arm_cmn *cmn)
+{
+	int i, j, irq, err;
+
+	for (i = 0; i < cmn->num_dtcs; i++) {
+		irq = cmn->dtc[i].irq;
+		for (j = i; j--; ) {
+			if (cmn->dtc[j].irq == irq) {
+				cmn->dtc[j].irq_friend = j - i;
+				goto next;
+			}
+		}
+		err = devm_request_irq(cmn->dev, irq, arm_cmn_handle_irq,
+				       IRQF_NOBALANCING | IRQF_NO_THREAD,
+				       dev_name(cmn->dev), &cmn->dtc[i]);
+		if (err)
+			return err;
+
+		err = irq_set_affinity_hint(irq, cpumask_of(cmn->cpu));
+		if (err)
+			return err;
+	next:
+		; /* isn't C great? */
+	}
+	return 0;
+}
+
+static void arm_cmn_init_dtm(struct arm_cmn_node *xp)
+{
+	int i;
+
+	for (i = 0; i < 4; i++) {
+		xp->wp_event[i] = -1;
+		writeq_relaxed(0, xp->pmu_base + CMN_DTM_WPn_MASK(i));
+		writeq_relaxed(~0ULL, xp->pmu_base + CMN_DTM_WPn_VAL(i));
+	}
+	xp->pmu_config_low = CMN_DTM_PMU_CONFIG_PMU_EN;
+	xp->dtc = -1;
+}
+
+static int arm_cmn_init_dtc(struct arm_cmn *cmn, struct arm_cmn_node *dn, int idx)
+{
+	struct arm_cmn_dtc *dtc = cmn->dtc + idx;
+	struct arm_cmn_node *xp;
+
+	dtc->base = dn->pmu_base - CMN_PMU_OFFSET;
+	dtc->irq = platform_get_irq(to_platform_device(cmn->dev), idx);
+	if (dtc->irq < 0)
+		return dtc->irq;
+
+	writel_relaxed(0, dtc->base + CMN_DT_PMCR);
+	writel_relaxed(0x1ff, dtc->base + CMN_DT_PMOVSR_CLR);
+	writel_relaxed(CMN_DT_PMCR_OVFL_INTR_EN, dtc->base + CMN_DT_PMCR);
+
+	/* We do at least know that a DTC's XP must be in that DTC's domain */
+	xp = arm_cmn_node_to_xp(dn);
+	xp->dtc = idx;
+
+	return 0;
+}
+
+static int arm_cmn_node_cmp(const void *a, const void *b)
+{
+	const struct arm_cmn_node *dna = a, *dnb = b;
+	int cmp;
+
+	cmp = dna->type - dnb->type;
+	if (!cmp)
+		cmp = dna->logid - dnb->logid;
+	return cmp;
+}
+
+static int arm_cmn_init_dtcs(struct arm_cmn *cmn)
+{
+	struct arm_cmn_node *dn;
+	int dtc_idx = 0;
+
+	cmn->dtc = devm_kcalloc(cmn->dev, cmn->num_dtcs, sizeof(cmn->dtc[0]), GFP_KERNEL);
+	if (!cmn->dtc)
+		return -ENOMEM;
+
+	sort(cmn->dns, cmn->num_dns, sizeof(cmn->dns[0]), arm_cmn_node_cmp, NULL);
+
+	cmn->xps = arm_cmn_node(cmn, CMN_TYPE_XP);
+
+	for (dn = cmn->dns; dn < cmn->dns + cmn->num_dns; dn++) {
+		if (dn->type != CMN_TYPE_XP)
+			arm_cmn_init_node_to_xp(cmn, dn);
+		else if (cmn->num_dtcs == 1)
+			dn->dtc = 0;
+
+		if (dn->type == CMN_TYPE_DTC)
+			arm_cmn_init_dtc(cmn, dn, dtc_idx++);
+
+		/* To the PMU, RN-Ds don't add anything over RN-Is, so smoosh them together */
+		if (dn->type == CMN_TYPE_RND)
+			dn->type = CMN_TYPE_RNI;
+	}
+
+	writel_relaxed(CMN_DT_DTC_CTL_DT_EN, cmn->dtc[0].base + CMN_DT_DTC_CTL);
+
+	return 0;
+}
+
+static void arm_cmn_init_node_info(struct arm_cmn *cmn, u32 offset, struct arm_cmn_node *node)
+{
+	int level;
+	u64 reg = readq_relaxed(cmn->base + offset + CMN_NODE_INFO);
+
+	node->type = FIELD_GET(CMN_NI_NODE_TYPE, reg);
+	node->id = FIELD_GET(CMN_NI_NODE_ID, reg);
+	node->logid = FIELD_GET(CMN_NI_LOGICAL_ID, reg);
+
+	node->pmu_base = cmn->base + offset + CMN_PMU_OFFSET;
+
+	if (node->type == CMN_TYPE_CFG)
+		level = 0;
+	else if (node->type == CMN_TYPE_XP)
+		level = 1;
+	else
+		level = 2;
+
+	dev_dbg(cmn->dev, "node%*c%#06hx%*ctype:%-#6hx id:%-4hd off:%#x\n",
+			(level * 2) + 1, ' ', node->id, 5 - (level * 2), ' ',
+			node->type, node->logid, offset);
+}
+
+static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset)
+{
+	void __iomem *cfg_region;
+	struct arm_cmn_node cfg, *dn;
+	u16 child_count, child_poff;
+	u32 xp_offset[CMN_MAX_XPS];
+	u64 reg;
+	int i, j;
+
+	cfg_region = cmn->base + rgn_offset;
+	reg = readl_relaxed(cfg_region + CMN_CFGM_PERIPH_ID_2);
+	cmn->rev = FIELD_GET(CMN_CFGM_PID2_REVISION, reg);
+	dev_dbg(cmn->dev, "periph_id_2 revision: %d\n", cmn->rev);
+
+	arm_cmn_init_node_info(cmn, rgn_offset, &cfg);
+	if (cfg.type != CMN_TYPE_CFG)
+		return -ENODEV;
+
+	reg = readq_relaxed(cfg_region + CMN_CHILD_INFO);
+	child_count = FIELD_GET(CMN_CI_CHILD_COUNT, reg);
+	child_poff = FIELD_GET(CMN_CI_CHILD_PTR_OFFSET, reg);
+
+	cmn->num_xps = child_count;
+	cmn->num_dns = cmn->num_xps;
+
+	/* Pass 1: visit the XPs, enumerate their children */
+	for (i = 0; i < cmn->num_xps; i++) {
+		reg = readq_relaxed(cfg_region + child_poff + i * 8);
+		xp_offset[i] = reg & CMN_CHILD_NODE_ADDR;
+
+		reg = readq_relaxed(cmn->base + xp_offset[i] + CMN_CHILD_INFO);
+		cmn->num_dns += FIELD_GET(CMN_CI_CHILD_COUNT, reg);
+	}
+
+	/* Cheeky +1 to help terminate pointer-based iteration */
+	cmn->dns = devm_kcalloc(cmn->dev, cmn->num_dns + 1,
+				sizeof(*cmn->dns), GFP_KERNEL);
+	if (!cmn->dns)
+		return -ENOMEM;
+
+	/* Pass 2: now we can actually populate the nodes */
+	dn = cmn->dns;
+	for (i = 0; i < cmn->num_xps; i++) {
+		void __iomem *xp_region = cmn->base + xp_offset[i];
+		struct arm_cmn_node *xp = dn++;
+
+		arm_cmn_init_node_info(cmn, xp_offset[i], xp);
+		arm_cmn_init_dtm(xp);
+		/*
+		 * Thanks to the order in which XP logical IDs seem to be
+		 * assigned, we can handily infer the mesh X dimension by
+		 * looking out for the XP at (0,1) without needing to know
+		 * the exact node ID format, which we can later derive.
+		 */
+		if (xp->id == (1 << 3))
+			cmn->mesh_x = xp->logid;
+
+		reg = readq_relaxed(xp_region + CMN_CHILD_INFO);
+		child_count = FIELD_GET(CMN_CI_CHILD_COUNT, reg);
+		child_poff = FIELD_GET(CMN_CI_CHILD_PTR_OFFSET, reg);
+
+		for (j = 0; j < child_count; j++) {
+			reg = readq_relaxed(xp_region + child_poff + j * 8);
+			/*
+			 * Don't even try to touch anything external, since in general
+			 * we haven't a clue how to power up arbitrary CHI requesters.
+			 * As of CMN-600r1 these could only be RN-SAMs or CXLAs,
+			 * neither of which have any PMU events anyway.
+			 * (Actually, CXLAs do seem to have grown some events in r1p2,
+			 * but they don't go to regular XP DTMs, and they depend on
+			 * secure configuration which we can't easily deal with)
+			 */
+			if (reg & CMN_CHILD_NODE_EXTERNAL) {
+				dev_dbg(cmn->dev, "ignoring external node %llx\n", reg);
+				continue;
+			}
+
+			arm_cmn_init_node_info(cmn, reg & CMN_CHILD_NODE_ADDR, dn);
+
+			switch (dn->type) {
+			case CMN_TYPE_DTC:
+				cmn->num_dtcs++;
+				dn++;
+				break;
+			/* These guys have PMU events */
+			case CMN_TYPE_DVM:
+			case CMN_TYPE_HNI:
+			case CMN_TYPE_HNF:
+			case CMN_TYPE_SBSX:
+			case CMN_TYPE_RNI:
+			case CMN_TYPE_RND:
+			case CMN_TYPE_CXRA:
+			case CMN_TYPE_CXHA:
+				dn++;
+				break;
+			/* Nothing to see here */
+			case CMN_TYPE_RNSAM:
+			case CMN_TYPE_CXLA:
+				break;
+			/* Something has gone horribly wrong */
+			default:
+				dev_err(cmn->dev, "invalid device node type: 0x%hx\n", dn->type);
+				return -ENODEV;
+			}
+		}
+	}
+
+	/* Correct for any nodes we skipped */
+	cmn->num_dns = dn - cmn->dns;
+
+	/*
+	 * If mesh_x wasn't set during discovery then we never saw
+	 * an XP at (0,1), thus we must have an Nx1 configuration.
+	 */
+	if (!cmn->mesh_x)
+		cmn->mesh_x = cmn->num_xps;
+	cmn->mesh_y = cmn->num_xps / cmn->mesh_x;
+
+	dev_dbg(cmn->dev, "mesh %dx%d, ID width %d\n",
+		cmn->mesh_x, cmn->mesh_y, arm_cmn_xyidbits(cmn));
+
+	return 0;
+}
+
+static int arm_cmn_acpi_probe(struct platform_device *pdev, struct arm_cmn *cmn)
+{
+	struct resource *cfg, *root;
+
+	cfg = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!cfg)
+		return -EINVAL;
+
+	root = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!root)
+		return -EINVAL;
+
+	if (!resource_contains(cfg, root))
+		swap(cfg, root);
+	/*
+	 * Note that devm_ioremap_resource() is dumb and won't let the platform
+	 * device claim cfg when the ACPI companion device has already claimed
+	 * root within it. But since they *are* already both claimed in the
+	 * appropriate name, we don't really need to do it again here anyway.
+	 */
+	cmn->base = devm_ioremap(cmn->dev, cfg->start, resource_size(cfg));
+	if (!cmn->base)
+		return -ENOMEM;
+
+	return root->start - cfg->start;
+}
+
+static int arm_cmn_of_probe(struct platform_device *pdev, struct arm_cmn *cmn)
+{
+	struct device_node *np = pdev->dev.of_node;
+	u32 rootnode;
+	int ret;
+
+	cmn->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(cmn->base))
+		return PTR_ERR(cmn->base);
+
+	ret = of_property_read_u32(np, "arm,root-node", &rootnode);
+	if (ret)
+		return ret;
+
+	return rootnode;
+}
+
+static int arm_cmn_probe(struct platform_device *pdev)
+{
+	struct arm_cmn *cmn;
+	const char *name;
+	static atomic_t id;
+	int err, rootnode, this_id;
+
+	cmn = devm_kzalloc(&pdev->dev, sizeof(*cmn), GFP_KERNEL);
+	if (!cmn)
+		return -ENOMEM;
+
+	cmn->dev = &pdev->dev;
+	platform_set_drvdata(pdev, cmn);
+
+	if (has_acpi_companion(cmn->dev))
+		rootnode = arm_cmn_acpi_probe(pdev, cmn);
+	else
+		rootnode = arm_cmn_of_probe(pdev, cmn);
+	if (rootnode < 0)
+		return rootnode;
+
+	err = arm_cmn_discover(cmn, rootnode);
+	if (err)
+		return err;
+
+	err = arm_cmn_init_dtcs(cmn);
+	if (err)
+		return err;
+
+	err = arm_cmn_init_irqs(cmn);
+	if (err)
+		return err;
+
+	cmn->cpu = raw_smp_processor_id();
+	cmn->pmu = (struct pmu) {
+		.module = THIS_MODULE,
+		.attr_groups = arm_cmn_attr_groups,
+		.capabilities = PERF_PMU_CAP_NO_EXCLUDE,
+		.task_ctx_nr = perf_invalid_context,
+		.pmu_enable = arm_cmn_pmu_enable,
+		.pmu_disable = arm_cmn_pmu_disable,
+		.event_init = arm_cmn_event_init,
+		.add = arm_cmn_event_add,
+		.del = arm_cmn_event_del,
+		.start = arm_cmn_event_start,
+		.stop = arm_cmn_event_stop,
+		.read = arm_cmn_event_read,
+		.start_txn = arm_cmn_start_txn,
+		.commit_txn = arm_cmn_commit_txn,
+		.cancel_txn = arm_cmn_end_txn,
+	};
+
+	this_id = atomic_fetch_inc(&id);
+	if (this_id == 0) {
+		name = "arm_cmn";
+	} else {
+		name = devm_kasprintf(cmn->dev, GFP_KERNEL, "arm_cmn_%d", this_id);
+		if (!name)
+			return -ENOMEM;
+	}
+
+	err = cpuhp_state_add_instance(arm_cmn_hp_state, &cmn->cpuhp_node);
+	if (err)
+		return err;
+
+	err = perf_pmu_register(&cmn->pmu, name, -1);
+	if (err)
+		cpuhp_state_remove_instance(arm_cmn_hp_state, &cmn->cpuhp_node);
+	return err;
+}
+
+static int arm_cmn_remove(struct platform_device *pdev)
+{
+	struct arm_cmn *cmn = platform_get_drvdata(pdev);
+	int i;
+
+	writel_relaxed(0, cmn->dtc[0].base + CMN_DT_DTC_CTL);
+
+	perf_pmu_unregister(&cmn->pmu);
+	cpuhp_state_remove_instance(arm_cmn_hp_state, &cmn->cpuhp_node);
+
+	for (i = 0; i < cmn->num_dtcs; i++)
+		irq_set_affinity_hint(cmn->dtc[i].irq, NULL);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id arm_cmn_of_match[] = {
+	{ .compatible = "arm,cmn-600", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, arm_cmn_of_match);
+#endif
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id arm_cmn_acpi_match[] = {
+	{ "ARMHC600", },
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, arm_cmn_acpi_match);
+#endif
+
+static struct platform_driver arm_cmn_driver = {
+	.driver = {
+		.name = "arm-cmn",
+		.of_match_table = of_match_ptr(arm_cmn_of_match),
+		.acpi_match_table = ACPI_PTR(arm_cmn_acpi_match),
+	},
+	.probe = arm_cmn_probe,
+	.remove = arm_cmn_remove,
+};
+
+static int __init arm_cmn_init(void)
+{
+	int ret;
+
+	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
+				      "perf/arm/cmn:online", NULL,
+				      arm_cmn_pmu_offline_cpu);
+	if (ret < 0)
+		return ret;
+
+	arm_cmn_hp_state = ret;
+	ret = platform_driver_register(&arm_cmn_driver);
+	if (ret)
+		cpuhp_remove_multi_state(arm_cmn_hp_state);
+	return ret;
+}
+
+static void __exit arm_cmn_exit(void)
+{
+	platform_driver_unregister(&arm_cmn_driver);
+	cpuhp_remove_multi_state(arm_cmn_hp_state);
+}
+
+module_init(arm_cmn_init);
+module_exit(arm_cmn_exit);
+
+MODULE_AUTHOR("Robin Murphy <[e-mail]>");
+MODULE_DESCRIPTION("Arm CMN-600 PMU driver");
+MODULE_LICENSE("GPL v2");