meta-arm/meta-arm-bsp/recipes-kernel/linux/linux-arm64-ack-5.15/tc/0025-perf-arm-cmn-Support-new-IP-features.patch

From 821c1c36ba8883a8709bbbcdf4ebc716e69da991 Mon Sep 17 00:00:00 2001
From: Robin Murphy <robin.murphy@arm.com>
Date: Fri, 3 Dec 2021 11:45:00 +0000
Subject: [PATCH 25/40] perf/arm-cmn: Support new IP features

The second generation of CMN IPs add new node types and significantly
expand the configuration space with options for extra device ports on
edge XPs, either plumbed into the regular DTM or with extra dedicated
DTMs to monitor them, plus larger (and smaller) mesh sizes. Add basic
support for pulling this new information out of the hardware, piping
it around as necessary, and handling (most of) the new choices.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/e58b495bcc7deec3882be4bac910ed0bf6979674.1638530442.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Upstream-Status = Backport [https://lore.kernel.org/r/e58b495bcc7deec3882be4bac910ed0bf6979674.1638530442.git.robin.murphy@arm.com]
Signed-off-by: Rupinderjit Singh <rupinderjit.singh@arm.com>
Signed-off-by: Arunachalam Ganapathy <arunachalam.ganapathy@arm.com>
---
 drivers/perf/arm-cmn.c | 218 ++++++++++++++++++++++++++++++++---------
 1 file changed, 171 insertions(+), 47 deletions(-)

diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
index ce94f923a607..0a3f33a83c01 100644
--- a/drivers/perf/arm-cmn.c
+++ b/drivers/perf/arm-cmn.c
@@ -24,7 +24,10 @@
 #define CMN_NI_LOGICAL_ID		GENMASK_ULL(47, 32)
 
 #define CMN_NODEID_DEVID(reg)		((reg) & 3)
+#define CMN_NODEID_EXT_DEVID(reg)	((reg) & 1)
 #define CMN_NODEID_PID(reg)		(((reg) >> 2) & 1)
+#define CMN_NODEID_EXT_PID(reg)		(((reg) >> 1) & 3)
+#define CMN_NODEID_1x1_PID(reg)		(((reg) >> 2) & 7)
 #define CMN_NODEID_X(reg, bits)		((reg) >> (3 + (bits)))
 #define CMN_NODEID_Y(reg, bits)		(((reg) >> 3) & ((1U << (bits)) - 1))
 
@@ -37,13 +40,26 @@
 
 #define CMN_MAX_DIMENSION		8
 #define CMN_MAX_XPS			(CMN_MAX_DIMENSION * CMN_MAX_DIMENSION)
-#define CMN_MAX_DTMS			CMN_MAX_XPS
+#define CMN_MAX_DTMS			(CMN_MAX_XPS + (CMN_MAX_DIMENSION - 1) * 4)
 
-/* The CFG node has one other useful purpose */
+/* The CFG node has various info besides the discovery tree */
 #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_CFGM_INFO_GLOBAL		0x900
+#define CMN_INFO_MULTIPLE_DTM_EN	BIT_ULL(63)
+#define CMN_INFO_RSP_VC_NUM		GENMASK_ULL(53, 52)
+#define CMN_INFO_DAT_VC_NUM		GENMASK_ULL(51, 50)
+
+/* XPs also have some local topology info which has uses too */
+#define CMN_MXP__CONNECT_INFO_P0	0x0008
+#define CMN_MXP__CONNECT_INFO_P1	0x0010
+#define CMN_MXP__CONNECT_INFO_P2	0x0028
+#define CMN_MXP__CONNECT_INFO_P3	0x0030
+#define CMN_MXP__CONNECT_INFO_P4	0x0038
+#define CMN_MXP__CONNECT_INFO_P5	0x0040
+
+/* PMU registers occupy the 3rd 4KB page of each node's region */
 #define CMN_PMU_OFFSET			0x2000
 
 /* For most nodes, this is all there is */
@@ -53,6 +69,7 @@
 /* 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_DEV_SEL2	GENMASK_ULL(18,17)
 #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)
@@ -77,7 +94,11 @@
 
 #define CMN_DTM_PMEVCNTSR		0x240
 
+#define CMN_DTM_UNIT_INFO		0x0910
+
 #define CMN_DTM_NUM_COUNTERS		4
+/* Want more local counters? Why not replicate the whole DTM! Ugh... */
+#define CMN_DTM_OFFSET(n)		((n) * 0x200)
 
 /* The DTC node is where the magic happens */
 #define CMN_DT_DTC_CTL			0x0a00
@@ -131,10 +152,10 @@
 #define CMN_EVENT_NODEID(event)		FIELD_GET(CMN_CONFIG_NODEID, (event)->attr.config)
 
 #define CMN_CONFIG_WP_COMBINE		GENMASK_ULL(27, 24)
-#define CMN_CONFIG_WP_DEV_SEL		BIT_ULL(48)
-#define CMN_CONFIG_WP_CHN_SEL		GENMASK_ULL(50, 49)
-#define CMN_CONFIG_WP_GRP		BIT_ULL(52)
-#define CMN_CONFIG_WP_EXCLUSIVE		BIT_ULL(53)
+#define CMN_CONFIG_WP_DEV_SEL		GENMASK_ULL(50, 48)
+#define CMN_CONFIG_WP_CHN_SEL		GENMASK_ULL(55, 51)
+#define CMN_CONFIG_WP_GRP		BIT_ULL(56)
+#define CMN_CONFIG_WP_EXCLUSIVE		BIT_ULL(57)
 #define CMN_CONFIG1_WP_VAL		GENMASK_ULL(63, 0)
 #define CMN_CONFIG2_WP_MASK		GENMASK_ULL(63, 0)
 
@@ -176,9 +197,12 @@ enum cmn_node_type {
 	CMN_TYPE_HNF,
 	CMN_TYPE_XP,
 	CMN_TYPE_SBSX,
-	CMN_TYPE_RNI = 0xa,
+	CMN_TYPE_MPAM_S,
+	CMN_TYPE_MPAM_NS,
+	CMN_TYPE_RNI,
 	CMN_TYPE_RND = 0xd,
 	CMN_TYPE_RNSAM = 0xf,
+	CMN_TYPE_MTSX,
 	CMN_TYPE_CXRA = 0x100,
 	CMN_TYPE_CXHA = 0x101,
 	CMN_TYPE_CXLA = 0x102,
@@ -233,6 +257,7 @@ struct arm_cmn_dtc {
 struct arm_cmn {
 	struct device *dev;
 	void __iomem *base;
+	unsigned int state;
 
 	enum cmn_revision rev;
 	enum cmn_model model;
@@ -240,6 +265,13 @@ struct arm_cmn {
 	u8 mesh_y;
 	u16 num_xps;
 	u16 num_dns;
+	bool multi_dtm;
+	u8 ports_used;
+	struct {
+		unsigned int rsp_vc_num : 2;
+		unsigned int dat_vc_num : 2;
+	};
+
 	struct arm_cmn_node *xps;
 	struct arm_cmn_node *dns;
 
@@ -250,7 +282,6 @@ struct arm_cmn {
 	int cpu;
 	struct hlist_node cpuhp_node;
 
-	unsigned int state;
 	struct pmu pmu;
 };
 
@@ -275,13 +306,25 @@ static int arm_cmn_xyidbits(const struct arm_cmn *cmn)
 static struct arm_cmn_nodeid arm_cmn_nid(const struct arm_cmn *cmn, u16 id)
 {
 	struct arm_cmn_nodeid nid;
-	int bits = arm_cmn_xyidbits(cmn);
 
-	nid.x = CMN_NODEID_X(id, bits);
-	nid.y = CMN_NODEID_Y(id, bits);
-	nid.port = CMN_NODEID_PID(id);
-	nid.dev = CMN_NODEID_DEVID(id);
+	if (cmn->num_xps == 1) {
+		nid.x = 0;
+		nid.y = 0;
+		nid.port = CMN_NODEID_1x1_PID(id);
+		nid.dev = CMN_NODEID_DEVID(id);
+	} else {
+		int bits = arm_cmn_xyidbits(cmn);
 
+		nid.x = CMN_NODEID_X(id, bits);
+		nid.y = CMN_NODEID_Y(id, bits);
+		if (cmn->ports_used & 0xc) {
+			nid.port = CMN_NODEID_EXT_PID(id);
+			nid.dev = CMN_NODEID_EXT_DEVID(id);
+		} else {
+			nid.port = CMN_NODEID_PID(id);
+			nid.dev = CMN_NODEID_DEVID(id);
+		}
+	}
 	return nid;
 }
 
@@ -310,6 +353,7 @@ struct arm_cmn_hw_event {
 	unsigned int dtc_idx;
 	u8 dtcs_used;
 	u8 num_dns;
+	u8 dtm_offset;
 };
 
 #define for_each_hw_dn(hw, dn, i) \
@@ -354,7 +398,8 @@ struct arm_cmn_format_attr {
 		.occupid = _occupid,					\
 	}})[0].attr.attr)
 
-static bool arm_cmn_is_occup_event(enum cmn_node_type type, unsigned int id)
+static bool arm_cmn_is_occup_event(enum cmn_model model,
+				   enum cmn_node_type type, unsigned int id)
 {
 	return (type == CMN_TYPE_DVM && id == 0x05) ||
 	       (type == CMN_TYPE_HNF && id == 0x0f);
@@ -375,7 +420,7 @@ static ssize_t arm_cmn_event_show(struct device *dev,
 				  "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))
+	if (arm_cmn_is_occup_event(eattr->model, eattr->type, eattr->eventid))
 		return sysfs_emit(buf, "type=0x%x,eventid=0x%x,occupid=0x%x\n",
 				  eattr->type, eattr->eventid, eattr->occupid);
 
@@ -390,25 +435,36 @@ static umode_t arm_cmn_event_attr_is_visible(struct kobject *kobj,
 	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;
 
 	if (!(eattr->model & cmn->model))
 		return 0;
 
-	/* Watchpoints aren't nodes */
-	if (type == CMN_TYPE_WP)
-		type = CMN_TYPE_XP;
+	/* Watchpoints aren't nodes, so avoid confusion */
+	if (eattr->type == CMN_TYPE_WP)
+		return attr->mode;
+
+	/* Hide XP events for unused interfaces/channels */
+	if (eattr->type == CMN_TYPE_XP) {
+		unsigned int intf = (eattr->eventid >> 2) & 7;
+		unsigned int chan = eattr->eventid >> 5;
+
+		if ((intf & 4) && !(cmn->ports_used & BIT(intf & 3)))
+			return 0;
+
+		if ((chan == 5 && cmn->rsp_vc_num < 2) ||
+		    (chan == 6 && cmn->dat_vc_num < 2))
+			return 0;
+	}
 
 	/* Revision-specific differences */
 	if (cmn->model == CMN600 && cmn->rev < CMN600_R1P2) {
-		if (type == CMN_TYPE_HNF && eattr->eventid == 0x1b)
+		if (eattr->type == CMN_TYPE_HNF && eattr->eventid == 0x1b)
 			return 0;
 	}
 
-	if (!arm_cmn_node(cmn, type))
+	if (!arm_cmn_node(cmn, eattr->type))
 		return 0;
 
 	return attr->mode;
@@ -669,7 +725,8 @@ static u32 arm_cmn_wp_config(struct perf_event *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);
+		 FIELD_PREP(CMN_DTM_WPn_CONFIG_WP_EXCLUSIVE, exc) |
+		 FIELD_PREP(CMN_DTM_WPn_CONFIG_WP_DEV_SEL2, dev >> 1);
 	if (combine && !grp)
 		config |= CMN_DTM_WPn_CONFIG_WP_COMBINE;
 
@@ -712,7 +769,7 @@ static u64 arm_cmn_read_dtm(struct arm_cmn *cmn, struct arm_cmn_hw_event *hw,
 	offset = snapshot ? CMN_DTM_PMEVCNTSR : CMN_DTM_PMEVCNT;
 	for_each_hw_dn(hw, dn, i) {
 		if (dtm != &cmn->dtms[dn->dtm]) {
-			dtm = &cmn->dtms[dn->dtm];
+			dtm = &cmn->dtms[dn->dtm] + hw->dtm_offset;
 			reg = readq_relaxed(dtm->base + offset);
 		}
 		dtm_idx = arm_cmn_get_index(hw->dtm_idx, i);
@@ -800,8 +857,10 @@ static void arm_cmn_event_start(struct perf_event *event, int flags)
 		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));
+			void __iomem *base = dn->pmu_base + CMN_DTM_OFFSET(hw->dtm_offset);
+
+			writeq_relaxed(val, base + CMN_DTM_WPn_VAL(wp_idx));
+			writeq_relaxed(mask, 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);
@@ -826,8 +885,10 @@ static void arm_cmn_event_stop(struct perf_event *event, int flags)
 		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));
+			void __iomem *base = dn->pmu_base + CMN_DTM_OFFSET(hw->dtm_offset);
+
+			writeq_relaxed(0, base + CMN_DTM_WPn_MASK(wp_idx));
+			writeq_relaxed(~0ULL, 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);
@@ -847,7 +908,8 @@ struct arm_cmn_val {
 	bool cycles;
 };
 
-static void arm_cmn_val_add_event(struct arm_cmn_val *val, struct perf_event *event)
+static void arm_cmn_val_add_event(struct arm_cmn *cmn, struct arm_cmn_val *val,
+				  struct perf_event *event)
 {
 	struct arm_cmn_hw_event *hw = to_cmn_hw(event);
 	struct arm_cmn_node *dn;
@@ -865,7 +927,7 @@ static void arm_cmn_val_add_event(struct arm_cmn_val *val, struct perf_event *ev
 	}
 
 	val->dtc_count++;
-	if (arm_cmn_is_occup_event(type, CMN_EVENT_EVENTID(event)))
+	if (arm_cmn_is_occup_event(cmn->model, type, CMN_EVENT_EVENTID(event)))
 		occupid = CMN_EVENT_OCCUPID(event) + 1;
 	else
 		occupid = 0;
@@ -884,7 +946,7 @@ static void arm_cmn_val_add_event(struct arm_cmn_val *val, struct perf_event *ev
 	}
 }
 
-static int arm_cmn_validate_group(struct perf_event *event)
+static int arm_cmn_validate_group(struct arm_cmn *cmn, struct perf_event *event)
 {
 	struct arm_cmn_hw_event *hw = to_cmn_hw(event);
 	struct arm_cmn_node *dn;
@@ -904,9 +966,9 @@ static int arm_cmn_validate_group(struct perf_event *event)
 	if (!val)
 		return -ENOMEM;
 
-	arm_cmn_val_add_event(val, leader);
+	arm_cmn_val_add_event(cmn, val, leader);
 	for_each_sibling_event(sibling, leader)
-		arm_cmn_val_add_event(val, sibling);
+		arm_cmn_val_add_event(cmn, val, sibling);
 
 	type = CMN_EVENT_TYPE(event);
 	if (type == CMN_TYPE_DTC) {
@@ -917,7 +979,7 @@ static int arm_cmn_validate_group(struct perf_event *event)
 	if (val->dtc_count == CMN_DT_NUM_COUNTERS)
 		goto done;
 
-	if (arm_cmn_is_occup_event(type, CMN_EVENT_EVENTID(event)))
+	if (arm_cmn_is_occup_event(cmn->model, type, CMN_EVENT_EVENTID(event)))
 		occupid = CMN_EVENT_OCCUPID(event) + 1;
 	else
 		occupid = 0;
@@ -980,6 +1042,9 @@ static int arm_cmn_event_init(struct perf_event *event)
 		eventid = CMN_EVENT_EVENTID(event);
 		if (eventid != CMN_WP_UP && eventid != CMN_WP_DOWN)
 			return -EINVAL;
+		/* ...but the DTM may depend on which port we're watching */
+		if (cmn->multi_dtm)
+			hw->dtm_offset = CMN_EVENT_WP_DEV_SEL(event) / 2;
 	}
 
 	bynodeid = CMN_EVENT_BYNODEID(event);
@@ -1007,7 +1072,7 @@ static int arm_cmn_event_init(struct perf_event *event)
 		return -EINVAL;
 	}
 
-	return arm_cmn_validate_group(event);
+	return arm_cmn_validate_group(cmn, event);
 }
 
 static void arm_cmn_event_clear(struct arm_cmn *cmn, struct perf_event *event,
@@ -1017,13 +1082,13 @@ static void arm_cmn_event_clear(struct arm_cmn *cmn, struct perf_event *event,
 	enum cmn_node_type type = CMN_EVENT_TYPE(event);
 
 	while (i--) {
-		struct arm_cmn_dtm *dtm = &cmn->dtms[hw->dn[i].dtm];
+		struct arm_cmn_dtm *dtm = &cmn->dtms[hw->dn[i].dtm] + hw->dtm_offset;
 		unsigned int dtm_idx = arm_cmn_get_index(hw->dtm_idx, i);
 
 		if (type == CMN_TYPE_WP)
 			dtm->wp_event[arm_cmn_wp_idx(event)] = -1;
 
-		if (arm_cmn_is_occup_event(type, CMN_EVENT_EVENTID(event)))
+		if (arm_cmn_is_occup_event(cmn->model, type, CMN_EVENT_EVENTID(event)))
 			hw->dn[i].occupid_count--;
 
 		dtm->pmu_config_low &= ~CMN__PMEVCNT_PAIRED(dtm_idx);
@@ -1069,7 +1134,7 @@ static int arm_cmn_event_add(struct perf_event *event, int flags)
 
 	/* ...then the local counters to feed it. */
 	for_each_hw_dn(hw, dn, i) {
-		struct arm_cmn_dtm *dtm = &cmn->dtms[dn->dtm];
+		struct arm_cmn_dtm *dtm = &cmn->dtms[dn->dtm] + hw->dtm_offset;
 		unsigned int dtm_idx, shift;
 		u64 reg;
 
@@ -1098,10 +1163,13 @@ static int arm_cmn_event_add(struct perf_event *event, int flags)
 		} else {
 			struct arm_cmn_nodeid nid = arm_cmn_nid(cmn, dn->id);
 
+			if (cmn->multi_dtm)
+				nid.port %= 2;
+
 			input_sel = CMN__PMEVCNT0_INPUT_SEL_DEV + dtm_idx +
 				    (nid.port << 4) + (nid.dev << 2);
 
-			if (arm_cmn_is_occup_event(type, CMN_EVENT_EVENTID(event))) {
+			if (arm_cmn_is_occup_event(cmn->model, type, CMN_EVENT_EVENTID(event))) {
 				u8 occupid = CMN_EVENT_OCCUPID(event);
 
 				if (dn->occupid_count == 0) {
@@ -1283,11 +1351,11 @@ static int arm_cmn_init_irqs(struct arm_cmn *cmn)
 	return 0;
 }
 
-static void arm_cmn_init_dtm(struct arm_cmn_dtm *dtm, struct arm_cmn_node *xp)
+static void arm_cmn_init_dtm(struct arm_cmn_dtm *dtm, struct arm_cmn_node *xp, int idx)
 {
 	int i;
 
-	dtm->base = xp->pmu_base;
+	dtm->base = xp->pmu_base + CMN_DTM_OFFSET(idx);
 	dtm->pmu_config_low = CMN_DTM_PMU_CONFIG_PMU_EN;
 	for (i = 0; i < 4; i++) {
 		dtm->wp_event[i] = -1;
@@ -1345,6 +1413,8 @@ static int arm_cmn_init_dtcs(struct arm_cmn *cmn)
 
 		xp = arm_cmn_node_to_xp(cmn, dn);
 		dn->dtm = xp->dtm;
+		if (cmn->multi_dtm)
+			dn->dtm += arm_cmn_nid(cmn, dn->id).port / 2;
 
 		if (dn->type == CMN_TYPE_DTC) {
 			int err;
@@ -1408,6 +1478,11 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset)
 	reg = readl_relaxed(cfg_region + CMN_CFGM_PERIPH_ID_2);
 	cmn->rev = FIELD_GET(CMN_CFGM_PID2_REVISION, reg);
 
+	reg = readq_relaxed(cfg_region + CMN_CFGM_INFO_GLOBAL);
+	cmn->multi_dtm = reg & CMN_INFO_MULTIPLE_DTM_EN;
+	cmn->rsp_vc_num = FIELD_GET(CMN_INFO_RSP_VC_NUM, reg);
+	cmn->dat_vc_num = FIELD_GET(CMN_INFO_DAT_VC_NUM, reg);
+
 	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);
@@ -1429,7 +1504,11 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset)
 	if (!dn)
 		return -ENOMEM;
 
-	dtm = devm_kcalloc(cmn->dev, cmn->num_xps, sizeof(*dtm), GFP_KERNEL);
+	/* Initial safe upper bound on DTMs for any possible mesh layout */
+	i = cmn->num_xps;
+	if (cmn->multi_dtm)
+		i += cmn->num_xps + 1;
+	dtm = devm_kcalloc(cmn->dev, i, sizeof(*dtm), GFP_KERNEL);
 	if (!dtm)
 		return -ENOMEM;
 
@@ -1439,6 +1518,7 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset)
 	for (i = 0; i < cmn->num_xps; i++) {
 		void __iomem *xp_region = cmn->base + xp_offset[i];
 		struct arm_cmn_node *xp = dn++;
+		unsigned int xp_ports = 0;
 
 		arm_cmn_init_node_info(cmn, xp_offset[i], xp);
 		/*
@@ -1450,9 +1530,39 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset)
 		if (xp->id == (1 << 3))
 			cmn->mesh_x = xp->logid;
 
-		xp->dtc = 0xf;
+		if (cmn->model == CMN600)
+			xp->dtc = 0xf;
+		else
+			xp->dtc = 1 << readl_relaxed(xp_region + CMN_DTM_UNIT_INFO);
+
 		xp->dtm = dtm - cmn->dtms;
-		arm_cmn_init_dtm(dtm++, xp);
+		arm_cmn_init_dtm(dtm++, xp, 0);
+		/*
+		 * Keeping track of connected ports will let us filter out
+		 * unnecessary XP events easily. We can also reliably infer the
+		 * "extra device ports" configuration for the node ID format
+		 * from this, since in that case we will see at least one XP
+		 * with port 2 connected, for the HN-D.
+		 */
+		if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P0))
+			xp_ports |= BIT(0);
+		if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P1))
+			xp_ports |= BIT(1);
+		if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P2))
+			xp_ports |= BIT(2);
+		if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P3))
+			xp_ports |= BIT(3);
+		if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P4))
+			xp_ports |= BIT(4);
+		if (readq_relaxed(xp_region + CMN_MXP__CONNECT_INFO_P5))
+			xp_ports |= BIT(5);
+
+		if (cmn->multi_dtm && (xp_ports & 0xc))
+			arm_cmn_init_dtm(dtm++, xp, 1);
+		if (cmn->multi_dtm && (xp_ports & 0x30))
+			arm_cmn_init_dtm(dtm++, xp, 2);
+
+		cmn->ports_used |= xp_ports;
 
 		reg = readq_relaxed(xp_region + CMN_CHILD_INFO);
 		child_count = FIELD_GET(CMN_CI_CHILD_COUNT, reg);
@@ -1488,11 +1598,14 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset)
 			case CMN_TYPE_SBSX:
 			case CMN_TYPE_RNI:
 			case CMN_TYPE_RND:
+			case CMN_TYPE_MTSX:
 			case CMN_TYPE_CXRA:
 			case CMN_TYPE_CXHA:
 				dn++;
 				break;
 			/* Nothing to see here */
+			case CMN_TYPE_MPAM_S:
+			case CMN_TYPE_MPAM_NS:
 			case CMN_TYPE_RNSAM:
 			case CMN_TYPE_CXLA:
 				break;
@@ -1512,6 +1625,11 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset)
 	if (dn)
 		cmn->dns = dn;
 
+	sz = (void *)dtm - (void *)cmn->dtms;
+	dtm = devm_krealloc(cmn->dev, cmn->dtms, sz, GFP_KERNEL);
+	if (dtm)
+		cmn->dtms = dtm;
+
 	/*
 	 * If mesh_x wasn't set during discovery then we never saw
 	 * an XP at (0,1), thus we must have an Nx1 configuration.
@@ -1520,9 +1638,15 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset)
 		cmn->mesh_x = cmn->num_xps;
 	cmn->mesh_y = cmn->num_xps / cmn->mesh_x;
 
+	/* 1x1 config plays havoc with XP event encodings */
+	if (cmn->num_xps == 1)
+		dev_warn(cmn->dev, "1x1 config not fully supported, translate XP events manually\n");
+
 	dev_dbg(cmn->dev, "model %d, periph_id_2 revision %d\n", cmn->model, cmn->rev);
-	dev_dbg(cmn->dev, "mesh %dx%d, ID width %d\n",
-		cmn->mesh_x, cmn->mesh_y, arm_cmn_xyidbits(cmn));
+	reg = cmn->ports_used;
+	dev_dbg(cmn->dev, "mesh %dx%d, ID width %d, ports %6pbl%s\n",
+		cmn->mesh_x, cmn->mesh_y, arm_cmn_xyidbits(cmn), &reg,
+		cmn->multi_dtm ? ", multi-DTM" : "");
 
 	return 0;
 }
-- 
2.34.1