xref: /linux/drivers/perf/arm-ni.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2022-2024 Arm Limited
3 // NI-700 Network-on-Chip PMU driver
4 
5 #include <linux/acpi.h>
6 #include <linux/bitfield.h>
7 #include <linux/interrupt.h>
8 #include <linux/io.h>
9 #include <linux/io-64-nonatomic-lo-hi.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/perf_event.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16 
17 /* Common registers */
18 #define NI_NODE_TYPE		0x000
19 #define NI_NODE_TYPE_NODE_ID	GENMASK(31, 16)
20 #define NI_NODE_TYPE_NODE_TYPE	GENMASK(15, 0)
21 
22 #define NI_CHILD_NODE_INFO	0x004
23 #define NI_CHILD_PTR(n)		(0x008 + (n) * 4)
24 
25 #define NI700_PMUSELA		0x00c
26 
27 /* Config node */
28 #define NI_PERIPHERAL_ID0	0xfe0
29 #define NI_PIDR0_PART_7_0	GENMASK(7, 0)
30 #define NI_PERIPHERAL_ID1	0xfe4
31 #define NI_PIDR1_PART_11_8	GENMASK(3, 0)
32 #define NI_PERIPHERAL_ID2	0xfe8
33 #define NI_PIDR2_VERSION	GENMASK(7, 4)
34 
35 /* PMU node */
36 #define NI_PMEVCNTR(n)		(0x008 + (n) * 8)
37 #define NI_PMCCNTR_L		0x0f8
38 #define NI_PMCCNTR_U		0x0fc
39 #define NI_PMEVTYPER(n)		(0x400 + (n) * 4)
40 #define NI_PMEVTYPER_NODE_TYPE	GENMASK(12, 9)
41 #define NI_PMEVTYPER_NODE_ID	GENMASK(8, 0)
42 #define NI_PMCNTENSET		0xc00
43 #define NI_PMCNTENCLR		0xc20
44 #define NI_PMINTENSET		0xc40
45 #define NI_PMINTENCLR		0xc60
46 #define NI_PMOVSCLR		0xc80
47 #define NI_PMOVSSET		0xcc0
48 #define NI_PMCFGR		0xe00
49 #define NI_PMCR			0xe04
50 #define NI_PMCR_RESET_CCNT	BIT(2)
51 #define NI_PMCR_RESET_EVCNT	BIT(1)
52 #define NI_PMCR_ENABLE		BIT(0)
53 
54 #define NI_NUM_COUNTERS		8
55 #define NI_CCNT_IDX		31
56 
57 /* Event attributes */
58 #define NI_CONFIG_TYPE		GENMASK_ULL(15, 0)
59 #define NI_CONFIG_NODEID	GENMASK_ULL(31, 16)
60 #define NI_CONFIG_EVENTID	GENMASK_ULL(47, 32)
61 
62 #define NI_EVENT_TYPE(event)	FIELD_GET(NI_CONFIG_TYPE, (event)->attr.config)
63 #define NI_EVENT_NODEID(event)	FIELD_GET(NI_CONFIG_NODEID, (event)->attr.config)
64 #define NI_EVENT_EVENTID(event)	FIELD_GET(NI_CONFIG_EVENTID, (event)->attr.config)
65 
66 enum ni_part {
67 	PART_NI_700 = 0x43b,
68 	PART_NI_710AE = 0x43d,
69 };
70 
71 enum ni_node_type {
72 	NI_GLOBAL,
73 	NI_VOLTAGE,
74 	NI_POWER,
75 	NI_CLOCK,
76 	NI_ASNI,
77 	NI_AMNI,
78 	NI_PMU,
79 	NI_HSNI,
80 	NI_HMNI,
81 	NI_PMNI,
82 };
83 
84 struct arm_ni_node {
85 	void __iomem *base;
86 	enum ni_node_type type;
87 	u16 id;
88 	u32 num_components;
89 };
90 
91 struct arm_ni_unit {
92 	void __iomem *pmusela;
93 	enum ni_node_type type;
94 	u16 id;
95 	bool ns;
96 	union {
97 		__le64 pmusel;
98 		u8 event[8];
99 	};
100 };
101 
102 struct arm_ni_cd {
103 	void __iomem *pmu_base;
104 	u16 id;
105 	int num_units;
106 	int irq;
107 	int cpu;
108 	struct hlist_node cpuhp_node;
109 	struct pmu pmu;
110 	struct arm_ni_unit *units;
111 	struct perf_event *evcnt[NI_NUM_COUNTERS];
112 	struct perf_event *ccnt;
113 };
114 
115 struct arm_ni {
116 	struct device *dev;
117 	void __iomem *base;
118 	enum ni_part part;
119 	int id;
120 	int num_cds;
121 	struct arm_ni_cd cds[] __counted_by(num_cds);
122 };
123 
124 #define cd_to_ni(cd) container_of((cd), struct arm_ni, cds[(cd)->id])
125 #define pmu_to_cd(p) container_of((p), struct arm_ni_cd, pmu)
126 
127 #define cd_for_each_unit(cd, u) \
128 	for (struct arm_ni_unit *u = cd->units; u < cd->units + cd->num_units; u++)
129 
130 static int arm_ni_hp_state;
131 
132 struct arm_ni_event_attr {
133 	struct device_attribute attr;
134 	enum ni_node_type type;
135 };
136 
137 #define NI_EVENT_ATTR(_name, _type)					\
138 	(&((struct arm_ni_event_attr[]) {{				\
139 		.attr = __ATTR(_name, 0444, arm_ni_event_show, NULL),	\
140 		.type = _type,						\
141 	}})[0].attr.attr)
142 
143 static ssize_t arm_ni_event_show(struct device *dev,
144 				 struct device_attribute *attr, char *buf)
145 {
146 	struct arm_ni_event_attr *eattr = container_of(attr, typeof(*eattr), attr);
147 
148 	if (eattr->type == NI_PMU)
149 		return sysfs_emit(buf, "type=0x%x\n", eattr->type);
150 
151 	return sysfs_emit(buf, "type=0x%x,eventid=?,nodeid=?\n", eattr->type);
152 }
153 
154 static umode_t arm_ni_event_attr_is_visible(struct kobject *kobj,
155 					    struct attribute *attr, int unused)
156 {
157 	struct device *dev = kobj_to_dev(kobj);
158 	struct arm_ni_cd *cd = pmu_to_cd(dev_get_drvdata(dev));
159 	struct arm_ni_event_attr *eattr;
160 
161 	eattr = container_of(attr, typeof(*eattr), attr.attr);
162 
163 	cd_for_each_unit(cd, unit) {
164 		if (unit->type == eattr->type && unit->ns)
165 			return attr->mode;
166 	}
167 
168 	return 0;
169 }
170 
171 static struct attribute *arm_ni_event_attrs[] = {
172 	NI_EVENT_ATTR(asni, NI_ASNI),
173 	NI_EVENT_ATTR(amni, NI_AMNI),
174 	NI_EVENT_ATTR(cycles, NI_PMU),
175 	NI_EVENT_ATTR(hsni, NI_HSNI),
176 	NI_EVENT_ATTR(hmni, NI_HMNI),
177 	NI_EVENT_ATTR(pmni, NI_PMNI),
178 	NULL
179 };
180 
181 static const struct attribute_group arm_ni_event_attrs_group = {
182 	.name = "events",
183 	.attrs = arm_ni_event_attrs,
184 	.is_visible = arm_ni_event_attr_is_visible,
185 };
186 
187 struct arm_ni_format_attr {
188 	struct device_attribute attr;
189 	u64 field;
190 };
191 
192 #define NI_FORMAT_ATTR(_name, _fld)					\
193 	(&((struct arm_ni_format_attr[]) {{				\
194 		.attr = __ATTR(_name, 0444, arm_ni_format_show, NULL),	\
195 		.field = _fld,						\
196 	}})[0].attr.attr)
197 
198 static ssize_t arm_ni_format_show(struct device *dev,
199 				  struct device_attribute *attr, char *buf)
200 {
201 	struct arm_ni_format_attr *fmt = container_of(attr, typeof(*fmt), attr);
202 
203 	return sysfs_emit(buf, "config:%*pbl\n", 64, &fmt->field);
204 }
205 
206 static struct attribute *arm_ni_format_attrs[] = {
207 	NI_FORMAT_ATTR(type, NI_CONFIG_TYPE),
208 	NI_FORMAT_ATTR(nodeid, NI_CONFIG_NODEID),
209 	NI_FORMAT_ATTR(eventid, NI_CONFIG_EVENTID),
210 	NULL
211 };
212 
213 static const struct attribute_group arm_ni_format_attrs_group = {
214 	.name = "format",
215 	.attrs = arm_ni_format_attrs,
216 };
217 
218 static ssize_t arm_ni_cpumask_show(struct device *dev,
219 				   struct device_attribute *attr, char *buf)
220 {
221 	struct arm_ni_cd *cd = pmu_to_cd(dev_get_drvdata(dev));
222 
223 	return cpumap_print_to_pagebuf(true, buf, cpumask_of(cd->cpu));
224 }
225 
226 static struct device_attribute arm_ni_cpumask_attr =
227 		__ATTR(cpumask, 0444, arm_ni_cpumask_show, NULL);
228 
229 static ssize_t arm_ni_identifier_show(struct device *dev,
230 				      struct device_attribute *attr, char *buf)
231 {
232 	struct arm_ni *ni = cd_to_ni(pmu_to_cd(dev_get_drvdata(dev)));
233 	u32 reg = readl_relaxed(ni->base + NI_PERIPHERAL_ID2);
234 	int version = FIELD_GET(NI_PIDR2_VERSION, reg);
235 
236 	return sysfs_emit(buf, "%03x%02x\n", ni->part, version);
237 }
238 
239 static struct device_attribute arm_ni_identifier_attr =
240 		__ATTR(identifier, 0444, arm_ni_identifier_show, NULL);
241 
242 static struct attribute *arm_ni_other_attrs[] = {
243 	&arm_ni_cpumask_attr.attr,
244 	&arm_ni_identifier_attr.attr,
245 	NULL
246 };
247 
248 static const struct attribute_group arm_ni_other_attr_group = {
249 	.attrs = arm_ni_other_attrs,
250 };
251 
252 static const struct attribute_group *arm_ni_attr_groups[] = {
253 	&arm_ni_event_attrs_group,
254 	&arm_ni_format_attrs_group,
255 	&arm_ni_other_attr_group,
256 	NULL
257 };
258 
259 static void arm_ni_pmu_enable(struct pmu *pmu)
260 {
261 	writel_relaxed(NI_PMCR_ENABLE, pmu_to_cd(pmu)->pmu_base + NI_PMCR);
262 }
263 
264 static void arm_ni_pmu_disable(struct pmu *pmu)
265 {
266 	writel_relaxed(0, pmu_to_cd(pmu)->pmu_base + NI_PMCR);
267 }
268 
269 struct arm_ni_val {
270 	unsigned int evcnt;
271 	unsigned int ccnt;
272 };
273 
274 static bool arm_ni_val_count_event(struct perf_event *evt, struct arm_ni_val *val)
275 {
276 	if (is_software_event(evt))
277 		return true;
278 
279 	if (NI_EVENT_TYPE(evt) == NI_PMU) {
280 		val->ccnt++;
281 		return val->ccnt <= 1;
282 	}
283 
284 	val->evcnt++;
285 	return val->evcnt <= NI_NUM_COUNTERS;
286 }
287 
288 static int arm_ni_validate_group(struct perf_event *event)
289 {
290 	struct perf_event *sibling, *leader = event->group_leader;
291 	struct arm_ni_val val = { 0 };
292 
293 	if (leader == event)
294 		return 0;
295 
296 	arm_ni_val_count_event(event, &val);
297 	if (!arm_ni_val_count_event(leader, &val))
298 		return -EINVAL;
299 
300 	for_each_sibling_event(sibling, leader) {
301 		if (!arm_ni_val_count_event(sibling, &val))
302 			return -EINVAL;
303 	}
304 	return 0;
305 }
306 
307 static int arm_ni_event_init(struct perf_event *event)
308 {
309 	struct arm_ni_cd *cd = pmu_to_cd(event->pmu);
310 
311 	if (event->attr.type != event->pmu->type)
312 		return -ENOENT;
313 
314 	if (is_sampling_event(event))
315 		return -EINVAL;
316 
317 	event->cpu = cd->cpu;
318 	if (NI_EVENT_TYPE(event) == NI_PMU)
319 		return arm_ni_validate_group(event);
320 
321 	cd_for_each_unit(cd, unit) {
322 		if (unit->type == NI_EVENT_TYPE(event) &&
323 		    unit->id == NI_EVENT_NODEID(event) && unit->ns) {
324 			event->hw.config_base = (unsigned long)unit;
325 			return arm_ni_validate_group(event);
326 		}
327 	}
328 	return -EINVAL;
329 }
330 
331 static u64 arm_ni_read_ccnt(struct arm_ni_cd *cd)
332 {
333 	u64 l, u_old, u_new;
334 	int retries = 3; /* 1st time unlucky, 2nd improbable, 3rd just broken */
335 
336 	u_new = readl_relaxed(cd->pmu_base + NI_PMCCNTR_U);
337 	do {
338 		u_old = u_new;
339 		l = readl_relaxed(cd->pmu_base + NI_PMCCNTR_L);
340 		u_new = readl_relaxed(cd->pmu_base + NI_PMCCNTR_U);
341 	} while (u_new != u_old && --retries);
342 	WARN_ON(!retries);
343 
344 	return (u_new << 32) | l;
345 }
346 
347 static void arm_ni_event_read(struct perf_event *event)
348 {
349 	struct arm_ni_cd *cd = pmu_to_cd(event->pmu);
350 	struct hw_perf_event *hw = &event->hw;
351 	u64 count, prev;
352 	bool ccnt = hw->idx == NI_CCNT_IDX;
353 
354 	do {
355 		prev = local64_read(&hw->prev_count);
356 		if (ccnt)
357 			count = arm_ni_read_ccnt(cd);
358 		else
359 			count = readl_relaxed(cd->pmu_base + NI_PMEVCNTR(hw->idx));
360 	} while (local64_cmpxchg(&hw->prev_count, prev, count) != prev);
361 
362 	count -= prev;
363 	if (!ccnt)
364 		count = (u32)count;
365 	local64_add(count, &event->count);
366 }
367 
368 static void arm_ni_event_start(struct perf_event *event, int flags)
369 {
370 	struct arm_ni_cd *cd = pmu_to_cd(event->pmu);
371 
372 	writel_relaxed(1U << event->hw.idx, cd->pmu_base + NI_PMCNTENSET);
373 }
374 
375 static void arm_ni_event_stop(struct perf_event *event, int flags)
376 {
377 	struct arm_ni_cd *cd = pmu_to_cd(event->pmu);
378 
379 	writel_relaxed(1U << event->hw.idx, cd->pmu_base + NI_PMCNTENCLR);
380 	if (flags & PERF_EF_UPDATE)
381 		arm_ni_event_read(event);
382 }
383 
384 static void arm_ni_init_ccnt(struct arm_ni_cd *cd)
385 {
386 	local64_set(&cd->ccnt->hw.prev_count, S64_MIN);
387 	lo_hi_writeq_relaxed(S64_MIN, cd->pmu_base + NI_PMCCNTR_L);
388 }
389 
390 static void arm_ni_init_evcnt(struct arm_ni_cd *cd, int idx)
391 {
392 	local64_set(&cd->evcnt[idx]->hw.prev_count, S32_MIN);
393 	writel_relaxed(S32_MIN, cd->pmu_base + NI_PMEVCNTR(idx));
394 }
395 
396 static int arm_ni_event_add(struct perf_event *event, int flags)
397 {
398 	struct arm_ni_cd *cd = pmu_to_cd(event->pmu);
399 	struct hw_perf_event *hw = &event->hw;
400 	struct arm_ni_unit *unit;
401 	enum ni_node_type type = NI_EVENT_TYPE(event);
402 	u32 reg;
403 
404 	if (type == NI_PMU) {
405 		if (cd->ccnt)
406 			return -ENOSPC;
407 		hw->idx = NI_CCNT_IDX;
408 		cd->ccnt = event;
409 		arm_ni_init_ccnt(cd);
410 	} else {
411 		hw->idx = 0;
412 		while (cd->evcnt[hw->idx]) {
413 			if (++hw->idx == NI_NUM_COUNTERS)
414 				return -ENOSPC;
415 		}
416 		cd->evcnt[hw->idx] = event;
417 		unit = (void *)hw->config_base;
418 		unit->event[hw->idx] = NI_EVENT_EVENTID(event);
419 		arm_ni_init_evcnt(cd, hw->idx);
420 		lo_hi_writeq_relaxed(le64_to_cpu(unit->pmusel), unit->pmusela);
421 
422 		reg = FIELD_PREP(NI_PMEVTYPER_NODE_TYPE, type) |
423 		      FIELD_PREP(NI_PMEVTYPER_NODE_ID, NI_EVENT_NODEID(event));
424 		writel_relaxed(reg, cd->pmu_base + NI_PMEVTYPER(hw->idx));
425 	}
426 	if (flags & PERF_EF_START)
427 		arm_ni_event_start(event, 0);
428 	return 0;
429 }
430 
431 static void arm_ni_event_del(struct perf_event *event, int flags)
432 {
433 	struct arm_ni_cd *cd = pmu_to_cd(event->pmu);
434 	struct hw_perf_event *hw = &event->hw;
435 
436 	arm_ni_event_stop(event, PERF_EF_UPDATE);
437 
438 	if (hw->idx == NI_CCNT_IDX)
439 		cd->ccnt = NULL;
440 	else
441 		cd->evcnt[hw->idx] = NULL;
442 }
443 
444 static irqreturn_t arm_ni_handle_irq(int irq, void *dev_id)
445 {
446 	struct arm_ni_cd *cd = dev_id;
447 	irqreturn_t ret = IRQ_NONE;
448 	u32 reg = readl_relaxed(cd->pmu_base + NI_PMOVSCLR);
449 
450 	if (reg & (1U << NI_CCNT_IDX)) {
451 		ret = IRQ_HANDLED;
452 		if (!(WARN_ON(!cd->ccnt))) {
453 			arm_ni_event_read(cd->ccnt);
454 			arm_ni_init_ccnt(cd);
455 		}
456 	}
457 	for (int i = 0; i < NI_NUM_COUNTERS; i++) {
458 		if (!(reg & (1U << i)))
459 			continue;
460 		ret = IRQ_HANDLED;
461 		if (!(WARN_ON(!cd->evcnt[i]))) {
462 			arm_ni_event_read(cd->evcnt[i]);
463 			arm_ni_init_evcnt(cd, i);
464 		}
465 	}
466 	writel_relaxed(reg, cd->pmu_base + NI_PMOVSCLR);
467 	return ret;
468 }
469 
470 static int arm_ni_init_cd(struct arm_ni *ni, struct arm_ni_node *node, u64 res_start)
471 {
472 	struct arm_ni_cd *cd = ni->cds + node->id;
473 	const char *name;
474 	int err;
475 
476 	cd->id = node->id;
477 	cd->num_units = node->num_components;
478 	cd->units = devm_kcalloc(ni->dev, cd->num_units, sizeof(*(cd->units)), GFP_KERNEL);
479 	if (!cd->units)
480 		return -ENOMEM;
481 
482 	for (int i = 0; i < cd->num_units; i++) {
483 		u32 reg = readl_relaxed(node->base + NI_CHILD_PTR(i));
484 		void __iomem *unit_base = ni->base + reg;
485 		struct arm_ni_unit *unit = cd->units + i;
486 
487 		reg = readl_relaxed(unit_base + NI_NODE_TYPE);
488 		unit->type = FIELD_GET(NI_NODE_TYPE_NODE_TYPE, reg);
489 		unit->id = FIELD_GET(NI_NODE_TYPE_NODE_ID, reg);
490 
491 		switch (unit->type) {
492 		case NI_PMU:
493 			reg = readl_relaxed(unit_base + NI_PMCFGR);
494 			if (!reg) {
495 				dev_info(ni->dev, "No access to PMU %d\n", cd->id);
496 				devm_kfree(ni->dev, cd->units);
497 				return 0;
498 			}
499 			unit->ns = true;
500 			cd->pmu_base = unit_base;
501 			break;
502 		case NI_ASNI:
503 		case NI_AMNI:
504 		case NI_HSNI:
505 		case NI_HMNI:
506 		case NI_PMNI:
507 			unit->pmusela = unit_base + NI700_PMUSELA;
508 			writel_relaxed(1, unit->pmusela);
509 			if (readl_relaxed(unit->pmusela) != 1)
510 				dev_info(ni->dev, "No access to node 0x%04x%04x\n", unit->id, unit->type);
511 			else
512 				unit->ns = true;
513 			break;
514 		default:
515 			/*
516 			 * e.g. FMU - thankfully bits 3:2 of FMU_ERR_FR0 are RES0 so
517 			 * can't alias any of the leaf node types we're looking for.
518 			 */
519 			dev_dbg(ni->dev, "Mystery node 0x%04x%04x\n", unit->id, unit->type);
520 			break;
521 		}
522 	}
523 
524 	res_start += cd->pmu_base - ni->base;
525 	if (!devm_request_mem_region(ni->dev, res_start, SZ_4K, dev_name(ni->dev))) {
526 		dev_err(ni->dev, "Failed to request PMU region 0x%llx\n", res_start);
527 		return -EBUSY;
528 	}
529 
530 	writel_relaxed(NI_PMCR_RESET_CCNT | NI_PMCR_RESET_EVCNT,
531 		       cd->pmu_base + NI_PMCR);
532 	writel_relaxed(U32_MAX, cd->pmu_base + NI_PMCNTENCLR);
533 	writel_relaxed(U32_MAX, cd->pmu_base + NI_PMOVSCLR);
534 	writel_relaxed(U32_MAX, cd->pmu_base + NI_PMINTENSET);
535 
536 	cd->irq = platform_get_irq(to_platform_device(ni->dev), cd->id);
537 	if (cd->irq < 0)
538 		return cd->irq;
539 
540 	err = devm_request_irq(ni->dev, cd->irq, arm_ni_handle_irq,
541 			       IRQF_NOBALANCING | IRQF_NO_THREAD,
542 			       dev_name(ni->dev), cd);
543 	if (err)
544 		return err;
545 
546 	cd->cpu = cpumask_local_spread(0, dev_to_node(ni->dev));
547 	cd->pmu = (struct pmu) {
548 		.module = THIS_MODULE,
549 		.parent = ni->dev,
550 		.attr_groups = arm_ni_attr_groups,
551 		.capabilities = PERF_PMU_CAP_NO_EXCLUDE,
552 		.task_ctx_nr = perf_invalid_context,
553 		.pmu_enable = arm_ni_pmu_enable,
554 		.pmu_disable = arm_ni_pmu_disable,
555 		.event_init = arm_ni_event_init,
556 		.add = arm_ni_event_add,
557 		.del = arm_ni_event_del,
558 		.start = arm_ni_event_start,
559 		.stop = arm_ni_event_stop,
560 		.read = arm_ni_event_read,
561 	};
562 
563 	name = devm_kasprintf(ni->dev, GFP_KERNEL, "arm_ni_%d_cd_%d", ni->id, cd->id);
564 	if (!name)
565 		return -ENOMEM;
566 
567 	err = cpuhp_state_add_instance_nocalls(arm_ni_hp_state, &cd->cpuhp_node);
568 	if (err)
569 		return err;
570 
571 	err = perf_pmu_register(&cd->pmu, name, -1);
572 	if (err)
573 		cpuhp_state_remove_instance_nocalls(arm_ni_hp_state, &cd->cpuhp_node);
574 
575 	return err;
576 }
577 
578 static void arm_ni_probe_domain(void __iomem *base, struct arm_ni_node *node)
579 {
580 	u32 reg = readl_relaxed(base + NI_NODE_TYPE);
581 
582 	node->base = base;
583 	node->type = FIELD_GET(NI_NODE_TYPE_NODE_TYPE, reg);
584 	node->id = FIELD_GET(NI_NODE_TYPE_NODE_ID, reg);
585 	node->num_components = readl_relaxed(base + NI_CHILD_NODE_INFO);
586 }
587 
588 static int arm_ni_probe(struct platform_device *pdev)
589 {
590 	struct arm_ni_node cfg, vd, pd, cd;
591 	struct arm_ni *ni;
592 	struct resource *res;
593 	void __iomem *base;
594 	static atomic_t id;
595 	int num_cds;
596 	u32 reg, part;
597 
598 	/*
599 	 * We want to map the whole configuration space for ease of discovery,
600 	 * but the PMU pages are the only ones for which we can honestly claim
601 	 * exclusive ownership, so we'll request them explicitly once found.
602 	 */
603 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
604 	base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
605 	if (!base)
606 		return -ENOMEM;
607 
608 	arm_ni_probe_domain(base, &cfg);
609 	if (cfg.type != NI_GLOBAL)
610 		return -ENODEV;
611 
612 	reg = readl_relaxed(cfg.base + NI_PERIPHERAL_ID0);
613 	part = FIELD_GET(NI_PIDR0_PART_7_0, reg);
614 	reg = readl_relaxed(cfg.base + NI_PERIPHERAL_ID1);
615 	part |= FIELD_GET(NI_PIDR1_PART_11_8, reg) << 8;
616 
617 	switch (part) {
618 	case PART_NI_700:
619 	case PART_NI_710AE:
620 		break;
621 	default:
622 		dev_WARN(&pdev->dev, "Unknown part number: 0x%03x, this may go badly\n", part);
623 		break;
624 	}
625 
626 	num_cds = 0;
627 	for (int v = 0; v < cfg.num_components; v++) {
628 		reg = readl_relaxed(cfg.base + NI_CHILD_PTR(v));
629 		arm_ni_probe_domain(base + reg, &vd);
630 		for (int p = 0; p < vd.num_components; p++) {
631 			reg = readl_relaxed(vd.base + NI_CHILD_PTR(p));
632 			arm_ni_probe_domain(base + reg, &pd);
633 			num_cds += pd.num_components;
634 		}
635 	}
636 
637 	ni = devm_kzalloc(&pdev->dev, struct_size(ni, cds, num_cds), GFP_KERNEL);
638 	if (!ni)
639 		return -ENOMEM;
640 
641 	ni->dev = &pdev->dev;
642 	ni->base = base;
643 	ni->num_cds = num_cds;
644 	ni->part = part;
645 	ni->id = atomic_fetch_inc(&id);
646 
647 	for (int v = 0; v < cfg.num_components; v++) {
648 		reg = readl_relaxed(cfg.base + NI_CHILD_PTR(v));
649 		arm_ni_probe_domain(base + reg, &vd);
650 		for (int p = 0; p < vd.num_components; p++) {
651 			reg = readl_relaxed(vd.base + NI_CHILD_PTR(p));
652 			arm_ni_probe_domain(base + reg, &pd);
653 			for (int c = 0; c < pd.num_components; c++) {
654 				int ret;
655 
656 				reg = readl_relaxed(pd.base + NI_CHILD_PTR(c));
657 				arm_ni_probe_domain(base + reg, &cd);
658 				ret = arm_ni_init_cd(ni, &cd, res->start);
659 				if (ret)
660 					return ret;
661 			}
662 		}
663 	}
664 
665 	return 0;
666 }
667 
668 static void arm_ni_remove(struct platform_device *pdev)
669 {
670 	struct arm_ni *ni = platform_get_drvdata(pdev);
671 
672 	for (int i = 0; i < ni->num_cds; i++) {
673 		struct arm_ni_cd *cd = ni->cds + i;
674 
675 		if (!cd->pmu_base)
676 			continue;
677 
678 		writel_relaxed(0, cd->pmu_base + NI_PMCR);
679 		writel_relaxed(U32_MAX, cd->pmu_base + NI_PMINTENCLR);
680 		perf_pmu_unregister(&cd->pmu);
681 		cpuhp_state_remove_instance_nocalls(arm_ni_hp_state, &cd->cpuhp_node);
682 	}
683 }
684 
685 #ifdef CONFIG_OF
686 static const struct of_device_id arm_ni_of_match[] = {
687 	{ .compatible = "arm,ni-700" },
688 	{}
689 };
690 MODULE_DEVICE_TABLE(of, arm_ni_of_match);
691 #endif
692 
693 #ifdef CONFIG_ACPI
694 static const struct acpi_device_id arm_ni_acpi_match[] = {
695 	{ "ARMHCB70" },
696 	{}
697 };
698 MODULE_DEVICE_TABLE(acpi, arm_ni_acpi_match);
699 #endif
700 
701 static struct platform_driver arm_ni_driver = {
702 	.driver = {
703 		.name = "arm-ni",
704 		.of_match_table = of_match_ptr(arm_ni_of_match),
705 		.acpi_match_table = ACPI_PTR(arm_ni_acpi_match),
706 	},
707 	.probe = arm_ni_probe,
708 	.remove = arm_ni_remove,
709 };
710 
711 static void arm_ni_pmu_migrate(struct arm_ni_cd *cd, unsigned int cpu)
712 {
713 	perf_pmu_migrate_context(&cd->pmu, cd->cpu, cpu);
714 	irq_set_affinity(cd->irq, cpumask_of(cpu));
715 	cd->cpu = cpu;
716 }
717 
718 static int arm_ni_pmu_online_cpu(unsigned int cpu, struct hlist_node *cpuhp_node)
719 {
720 	struct arm_ni_cd *cd;
721 	int node;
722 
723 	cd = hlist_entry_safe(cpuhp_node, struct arm_ni_cd, cpuhp_node);
724 	node = dev_to_node(cd_to_ni(cd)->dev);
725 	if (cpu_to_node(cd->cpu) != node && cpu_to_node(cpu) == node)
726 		arm_ni_pmu_migrate(cd, cpu);
727 	return 0;
728 }
729 
730 static int arm_ni_pmu_offline_cpu(unsigned int cpu, struct hlist_node *cpuhp_node)
731 {
732 	struct arm_ni_cd *cd;
733 	unsigned int target;
734 	int node;
735 
736 	cd = hlist_entry_safe(cpuhp_node, struct arm_ni_cd, cpuhp_node);
737 	if (cpu != cd->cpu)
738 		return 0;
739 
740 	node = dev_to_node(cd_to_ni(cd)->dev);
741 	target = cpumask_any_and_but(cpumask_of_node(node), cpu_online_mask, cpu);
742 	if (target >= nr_cpu_ids)
743 		target = cpumask_any_but(cpu_online_mask, cpu);
744 
745 	if (target < nr_cpu_ids)
746 		arm_ni_pmu_migrate(cd, target);
747 	return 0;
748 }
749 
750 static int __init arm_ni_init(void)
751 {
752 	int ret;
753 
754 	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
755 				      "perf/arm/ni:online",
756 				      arm_ni_pmu_online_cpu,
757 				      arm_ni_pmu_offline_cpu);
758 	if (ret < 0)
759 		return ret;
760 
761 	arm_ni_hp_state = ret;
762 
763 	ret = platform_driver_register(&arm_ni_driver);
764 	if (ret)
765 		cpuhp_remove_multi_state(arm_ni_hp_state);
766 	return ret;
767 }
768 
769 static void __exit arm_ni_exit(void)
770 {
771 	platform_driver_unregister(&arm_ni_driver);
772 	cpuhp_remove_multi_state(arm_ni_hp_state);
773 }
774 
775 module_init(arm_ni_init);
776 module_exit(arm_ni_exit);
777 
778 MODULE_AUTHOR("Robin Murphy <robin.murphy@arm.com>");
779 MODULE_DESCRIPTION("Arm NI-700 PMU driver");
780 MODULE_LICENSE("GPL v2");
781