1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2017 NXP
4  * Copyright 2016 Freescale Semiconductor, Inc.
5  */
6 
7 #include <linux/bitfield.h>
8 #include <linux/init.h>
9 #include <linux/interrupt.h>
10 #include <linux/io.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/of_address.h>
14 #include <linux/of_device.h>
15 #include <linux/of_irq.h>
16 #include <linux/perf_event.h>
17 #include <linux/slab.h>
18 
19 #define COUNTER_CNTL		0x0
20 #define COUNTER_READ		0x20
21 
22 #define COUNTER_DPCR1		0x30
23 
24 #define CNTL_OVER		0x1
25 #define CNTL_CLEAR		0x2
26 #define CNTL_EN			0x4
27 #define CNTL_EN_MASK		0xFFFFFFFB
28 #define CNTL_CLEAR_MASK		0xFFFFFFFD
29 #define CNTL_OVER_MASK		0xFFFFFFFE
30 
31 #define CNTL_CSV_SHIFT		24
32 #define CNTL_CSV_MASK		(0xFF << CNTL_CSV_SHIFT)
33 
34 #define EVENT_CYCLES_ID		0
35 #define EVENT_CYCLES_COUNTER	0
36 #define NUM_COUNTERS		4
37 
38 #define AXI_MASKING_REVERT	0xffff0000	/* AXI_MASKING(MSB 16bits) + AXI_ID(LSB 16bits) */
39 
40 #define to_ddr_pmu(p)		container_of(p, struct ddr_pmu, pmu)
41 
42 #define DDR_PERF_DEV_NAME	"imx8_ddr"
43 #define DDR_CPUHP_CB_NAME	DDR_PERF_DEV_NAME "_perf_pmu"
44 
45 static DEFINE_IDA(ddr_ida);
46 
47 /* DDR Perf hardware feature */
48 #define DDR_CAP_AXI_ID_FILTER			0x1     /* support AXI ID filter */
49 #define DDR_CAP_AXI_ID_FILTER_ENHANCED		0x3     /* support enhanced AXI ID filter */
50 
51 struct fsl_ddr_devtype_data {
52 	unsigned int quirks;    /* quirks needed for different DDR Perf core */
53 };
54 
55 static const struct fsl_ddr_devtype_data imx8_devtype_data;
56 
57 static const struct fsl_ddr_devtype_data imx8m_devtype_data = {
58 	.quirks = DDR_CAP_AXI_ID_FILTER,
59 };
60 
61 static const struct fsl_ddr_devtype_data imx8mp_devtype_data = {
62 	.quirks = DDR_CAP_AXI_ID_FILTER_ENHANCED,
63 };
64 
65 static const struct of_device_id imx_ddr_pmu_dt_ids[] = {
66 	{ .compatible = "fsl,imx8-ddr-pmu", .data = &imx8_devtype_data},
67 	{ .compatible = "fsl,imx8m-ddr-pmu", .data = &imx8m_devtype_data},
68 	{ .compatible = "fsl,imx8mp-ddr-pmu", .data = &imx8mp_devtype_data},
69 	{ /* sentinel */ }
70 };
71 MODULE_DEVICE_TABLE(of, imx_ddr_pmu_dt_ids);
72 
73 struct ddr_pmu {
74 	struct pmu pmu;
75 	void __iomem *base;
76 	unsigned int cpu;
77 	struct	hlist_node node;
78 	struct	device *dev;
79 	struct perf_event *events[NUM_COUNTERS];
80 	int active_events;
81 	enum cpuhp_state cpuhp_state;
82 	const struct fsl_ddr_devtype_data *devtype_data;
83 	int irq;
84 	int id;
85 };
86 
87 enum ddr_perf_filter_capabilities {
88 	PERF_CAP_AXI_ID_FILTER = 0,
89 	PERF_CAP_AXI_ID_FILTER_ENHANCED,
90 	PERF_CAP_AXI_ID_FEAT_MAX,
91 };
92 
93 static u32 ddr_perf_filter_cap_get(struct ddr_pmu *pmu, int cap)
94 {
95 	u32 quirks = pmu->devtype_data->quirks;
96 
97 	switch (cap) {
98 	case PERF_CAP_AXI_ID_FILTER:
99 		return !!(quirks & DDR_CAP_AXI_ID_FILTER);
100 	case PERF_CAP_AXI_ID_FILTER_ENHANCED:
101 		quirks &= DDR_CAP_AXI_ID_FILTER_ENHANCED;
102 		return quirks == DDR_CAP_AXI_ID_FILTER_ENHANCED;
103 	default:
104 		WARN(1, "unknown filter cap %d\n", cap);
105 	}
106 
107 	return 0;
108 }
109 
110 static ssize_t ddr_perf_filter_cap_show(struct device *dev,
111 					struct device_attribute *attr,
112 					char *buf)
113 {
114 	struct ddr_pmu *pmu = dev_get_drvdata(dev);
115 	struct dev_ext_attribute *ea =
116 		container_of(attr, struct dev_ext_attribute, attr);
117 	int cap = (long)ea->var;
118 
119 	return snprintf(buf, PAGE_SIZE, "%u\n",
120 			ddr_perf_filter_cap_get(pmu, cap));
121 }
122 
123 #define PERF_EXT_ATTR_ENTRY(_name, _func, _var)				\
124 	(&((struct dev_ext_attribute) {					\
125 		__ATTR(_name, 0444, _func, NULL), (void *)_var		\
126 	}).attr.attr)
127 
128 #define PERF_FILTER_EXT_ATTR_ENTRY(_name, _var)				\
129 	PERF_EXT_ATTR_ENTRY(_name, ddr_perf_filter_cap_show, _var)
130 
131 static struct attribute *ddr_perf_filter_cap_attr[] = {
132 	PERF_FILTER_EXT_ATTR_ENTRY(filter, PERF_CAP_AXI_ID_FILTER),
133 	PERF_FILTER_EXT_ATTR_ENTRY(enhanced_filter, PERF_CAP_AXI_ID_FILTER_ENHANCED),
134 	NULL,
135 };
136 
137 static struct attribute_group ddr_perf_filter_cap_attr_group = {
138 	.name = "caps",
139 	.attrs = ddr_perf_filter_cap_attr,
140 };
141 
142 static ssize_t ddr_perf_cpumask_show(struct device *dev,
143 				struct device_attribute *attr, char *buf)
144 {
145 	struct ddr_pmu *pmu = dev_get_drvdata(dev);
146 
147 	return cpumap_print_to_pagebuf(true, buf, cpumask_of(pmu->cpu));
148 }
149 
150 static struct device_attribute ddr_perf_cpumask_attr =
151 	__ATTR(cpumask, 0444, ddr_perf_cpumask_show, NULL);
152 
153 static struct attribute *ddr_perf_cpumask_attrs[] = {
154 	&ddr_perf_cpumask_attr.attr,
155 	NULL,
156 };
157 
158 static struct attribute_group ddr_perf_cpumask_attr_group = {
159 	.attrs = ddr_perf_cpumask_attrs,
160 };
161 
162 static ssize_t
163 ddr_pmu_event_show(struct device *dev, struct device_attribute *attr,
164 		   char *page)
165 {
166 	struct perf_pmu_events_attr *pmu_attr;
167 
168 	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
169 	return sprintf(page, "event=0x%02llx\n", pmu_attr->id);
170 }
171 
172 #define IMX8_DDR_PMU_EVENT_ATTR(_name, _id)				\
173 	(&((struct perf_pmu_events_attr[]) {				\
174 		{ .attr = __ATTR(_name, 0444, ddr_pmu_event_show, NULL),\
175 		  .id = _id, }						\
176 	})[0].attr.attr)
177 
178 static struct attribute *ddr_perf_events_attrs[] = {
179 	IMX8_DDR_PMU_EVENT_ATTR(cycles, EVENT_CYCLES_ID),
180 	IMX8_DDR_PMU_EVENT_ATTR(selfresh, 0x01),
181 	IMX8_DDR_PMU_EVENT_ATTR(read-accesses, 0x04),
182 	IMX8_DDR_PMU_EVENT_ATTR(write-accesses, 0x05),
183 	IMX8_DDR_PMU_EVENT_ATTR(read-queue-depth, 0x08),
184 	IMX8_DDR_PMU_EVENT_ATTR(write-queue-depth, 0x09),
185 	IMX8_DDR_PMU_EVENT_ATTR(lp-read-credit-cnt, 0x10),
186 	IMX8_DDR_PMU_EVENT_ATTR(hp-read-credit-cnt, 0x11),
187 	IMX8_DDR_PMU_EVENT_ATTR(write-credit-cnt, 0x12),
188 	IMX8_DDR_PMU_EVENT_ATTR(read-command, 0x20),
189 	IMX8_DDR_PMU_EVENT_ATTR(write-command, 0x21),
190 	IMX8_DDR_PMU_EVENT_ATTR(read-modify-write-command, 0x22),
191 	IMX8_DDR_PMU_EVENT_ATTR(hp-read, 0x23),
192 	IMX8_DDR_PMU_EVENT_ATTR(hp-req-nocredit, 0x24),
193 	IMX8_DDR_PMU_EVENT_ATTR(hp-xact-credit, 0x25),
194 	IMX8_DDR_PMU_EVENT_ATTR(lp-req-nocredit, 0x26),
195 	IMX8_DDR_PMU_EVENT_ATTR(lp-xact-credit, 0x27),
196 	IMX8_DDR_PMU_EVENT_ATTR(wr-xact-credit, 0x29),
197 	IMX8_DDR_PMU_EVENT_ATTR(read-cycles, 0x2a),
198 	IMX8_DDR_PMU_EVENT_ATTR(write-cycles, 0x2b),
199 	IMX8_DDR_PMU_EVENT_ATTR(read-write-transition, 0x30),
200 	IMX8_DDR_PMU_EVENT_ATTR(precharge, 0x31),
201 	IMX8_DDR_PMU_EVENT_ATTR(activate, 0x32),
202 	IMX8_DDR_PMU_EVENT_ATTR(load-mode, 0x33),
203 	IMX8_DDR_PMU_EVENT_ATTR(perf-mwr, 0x34),
204 	IMX8_DDR_PMU_EVENT_ATTR(read, 0x35),
205 	IMX8_DDR_PMU_EVENT_ATTR(read-activate, 0x36),
206 	IMX8_DDR_PMU_EVENT_ATTR(refresh, 0x37),
207 	IMX8_DDR_PMU_EVENT_ATTR(write, 0x38),
208 	IMX8_DDR_PMU_EVENT_ATTR(raw-hazard, 0x39),
209 	IMX8_DDR_PMU_EVENT_ATTR(axid-read, 0x41),
210 	IMX8_DDR_PMU_EVENT_ATTR(axid-write, 0x42),
211 	NULL,
212 };
213 
214 static struct attribute_group ddr_perf_events_attr_group = {
215 	.name = "events",
216 	.attrs = ddr_perf_events_attrs,
217 };
218 
219 PMU_FORMAT_ATTR(event, "config:0-7");
220 PMU_FORMAT_ATTR(axi_id, "config1:0-15");
221 PMU_FORMAT_ATTR(axi_mask, "config1:16-31");
222 
223 static struct attribute *ddr_perf_format_attrs[] = {
224 	&format_attr_event.attr,
225 	&format_attr_axi_id.attr,
226 	&format_attr_axi_mask.attr,
227 	NULL,
228 };
229 
230 static struct attribute_group ddr_perf_format_attr_group = {
231 	.name = "format",
232 	.attrs = ddr_perf_format_attrs,
233 };
234 
235 static const struct attribute_group *attr_groups[] = {
236 	&ddr_perf_events_attr_group,
237 	&ddr_perf_format_attr_group,
238 	&ddr_perf_cpumask_attr_group,
239 	&ddr_perf_filter_cap_attr_group,
240 	NULL,
241 };
242 
243 static bool ddr_perf_is_filtered(struct perf_event *event)
244 {
245 	return event->attr.config == 0x41 || event->attr.config == 0x42;
246 }
247 
248 static u32 ddr_perf_filter_val(struct perf_event *event)
249 {
250 	return event->attr.config1;
251 }
252 
253 static bool ddr_perf_filters_compatible(struct perf_event *a,
254 					struct perf_event *b)
255 {
256 	if (!ddr_perf_is_filtered(a))
257 		return true;
258 	if (!ddr_perf_is_filtered(b))
259 		return true;
260 	return ddr_perf_filter_val(a) == ddr_perf_filter_val(b);
261 }
262 
263 static bool ddr_perf_is_enhanced_filtered(struct perf_event *event)
264 {
265 	unsigned int filt;
266 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
267 
268 	filt = pmu->devtype_data->quirks & DDR_CAP_AXI_ID_FILTER_ENHANCED;
269 	return (filt == DDR_CAP_AXI_ID_FILTER_ENHANCED) &&
270 		ddr_perf_is_filtered(event);
271 }
272 
273 static u32 ddr_perf_alloc_counter(struct ddr_pmu *pmu, int event)
274 {
275 	int i;
276 
277 	/*
278 	 * Always map cycle event to counter 0
279 	 * Cycles counter is dedicated for cycle event
280 	 * can't used for the other events
281 	 */
282 	if (event == EVENT_CYCLES_ID) {
283 		if (pmu->events[EVENT_CYCLES_COUNTER] == NULL)
284 			return EVENT_CYCLES_COUNTER;
285 		else
286 			return -ENOENT;
287 	}
288 
289 	for (i = 1; i < NUM_COUNTERS; i++) {
290 		if (pmu->events[i] == NULL)
291 			return i;
292 	}
293 
294 	return -ENOENT;
295 }
296 
297 static void ddr_perf_free_counter(struct ddr_pmu *pmu, int counter)
298 {
299 	pmu->events[counter] = NULL;
300 }
301 
302 static u32 ddr_perf_read_counter(struct ddr_pmu *pmu, int counter)
303 {
304 	struct perf_event *event = pmu->events[counter];
305 	void __iomem *base = pmu->base;
306 
307 	/*
308 	 * return bytes instead of bursts from ddr transaction for
309 	 * axid-read and axid-write event if PMU core supports enhanced
310 	 * filter.
311 	 */
312 	base += ddr_perf_is_enhanced_filtered(event) ? COUNTER_DPCR1 :
313 						       COUNTER_READ;
314 	return readl_relaxed(base + counter * 4);
315 }
316 
317 static int ddr_perf_event_init(struct perf_event *event)
318 {
319 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
320 	struct hw_perf_event *hwc = &event->hw;
321 	struct perf_event *sibling;
322 
323 	if (event->attr.type != event->pmu->type)
324 		return -ENOENT;
325 
326 	if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
327 		return -EOPNOTSUPP;
328 
329 	if (event->cpu < 0) {
330 		dev_warn(pmu->dev, "Can't provide per-task data!\n");
331 		return -EOPNOTSUPP;
332 	}
333 
334 	/*
335 	 * We must NOT create groups containing mixed PMUs, although software
336 	 * events are acceptable (for example to create a CCN group
337 	 * periodically read when a hrtimer aka cpu-clock leader triggers).
338 	 */
339 	if (event->group_leader->pmu != event->pmu &&
340 			!is_software_event(event->group_leader))
341 		return -EINVAL;
342 
343 	if (pmu->devtype_data->quirks & DDR_CAP_AXI_ID_FILTER) {
344 		if (!ddr_perf_filters_compatible(event, event->group_leader))
345 			return -EINVAL;
346 		for_each_sibling_event(sibling, event->group_leader) {
347 			if (!ddr_perf_filters_compatible(event, sibling))
348 				return -EINVAL;
349 		}
350 	}
351 
352 	for_each_sibling_event(sibling, event->group_leader) {
353 		if (sibling->pmu != event->pmu &&
354 				!is_software_event(sibling))
355 			return -EINVAL;
356 	}
357 
358 	event->cpu = pmu->cpu;
359 	hwc->idx = -1;
360 
361 	return 0;
362 }
363 
364 
365 static void ddr_perf_event_update(struct perf_event *event)
366 {
367 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
368 	struct hw_perf_event *hwc = &event->hw;
369 	u64 delta, prev_raw_count, new_raw_count;
370 	int counter = hwc->idx;
371 
372 	do {
373 		prev_raw_count = local64_read(&hwc->prev_count);
374 		new_raw_count = ddr_perf_read_counter(pmu, counter);
375 	} while (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
376 			new_raw_count) != prev_raw_count);
377 
378 	delta = (new_raw_count - prev_raw_count) & 0xFFFFFFFF;
379 
380 	local64_add(delta, &event->count);
381 }
382 
383 static void ddr_perf_counter_enable(struct ddr_pmu *pmu, int config,
384 				  int counter, bool enable)
385 {
386 	u8 reg = counter * 4 + COUNTER_CNTL;
387 	int val;
388 
389 	if (enable) {
390 		/*
391 		 * cycle counter is special which should firstly write 0 then
392 		 * write 1 into CLEAR bit to clear it. Other counters only
393 		 * need write 0 into CLEAR bit and it turns out to be 1 by
394 		 * hardware. Below enable flow is harmless for all counters.
395 		 */
396 		writel(0, pmu->base + reg);
397 		val = CNTL_EN | CNTL_CLEAR;
398 		val |= FIELD_PREP(CNTL_CSV_MASK, config);
399 		writel(val, pmu->base + reg);
400 	} else {
401 		/* Disable counter */
402 		val = readl_relaxed(pmu->base + reg) & CNTL_EN_MASK;
403 		writel(val, pmu->base + reg);
404 	}
405 }
406 
407 static void ddr_perf_event_start(struct perf_event *event, int flags)
408 {
409 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
410 	struct hw_perf_event *hwc = &event->hw;
411 	int counter = hwc->idx;
412 
413 	local64_set(&hwc->prev_count, 0);
414 
415 	ddr_perf_counter_enable(pmu, event->attr.config, counter, true);
416 
417 	hwc->state = 0;
418 }
419 
420 static int ddr_perf_event_add(struct perf_event *event, int flags)
421 {
422 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
423 	struct hw_perf_event *hwc = &event->hw;
424 	int counter;
425 	int cfg = event->attr.config;
426 	int cfg1 = event->attr.config1;
427 
428 	if (pmu->devtype_data->quirks & DDR_CAP_AXI_ID_FILTER) {
429 		int i;
430 
431 		for (i = 1; i < NUM_COUNTERS; i++) {
432 			if (pmu->events[i] &&
433 			    !ddr_perf_filters_compatible(event, pmu->events[i]))
434 				return -EINVAL;
435 		}
436 
437 		if (ddr_perf_is_filtered(event)) {
438 			/* revert axi id masking(axi_mask) value */
439 			cfg1 ^= AXI_MASKING_REVERT;
440 			writel(cfg1, pmu->base + COUNTER_DPCR1);
441 		}
442 	}
443 
444 	counter = ddr_perf_alloc_counter(pmu, cfg);
445 	if (counter < 0) {
446 		dev_dbg(pmu->dev, "There are not enough counters\n");
447 		return -EOPNOTSUPP;
448 	}
449 
450 	pmu->events[counter] = event;
451 	pmu->active_events++;
452 	hwc->idx = counter;
453 
454 	hwc->state |= PERF_HES_STOPPED;
455 
456 	if (flags & PERF_EF_START)
457 		ddr_perf_event_start(event, flags);
458 
459 	return 0;
460 }
461 
462 static void ddr_perf_event_stop(struct perf_event *event, int flags)
463 {
464 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
465 	struct hw_perf_event *hwc = &event->hw;
466 	int counter = hwc->idx;
467 
468 	ddr_perf_counter_enable(pmu, event->attr.config, counter, false);
469 	ddr_perf_event_update(event);
470 
471 	hwc->state |= PERF_HES_STOPPED;
472 }
473 
474 static void ddr_perf_event_del(struct perf_event *event, int flags)
475 {
476 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
477 	struct hw_perf_event *hwc = &event->hw;
478 	int counter = hwc->idx;
479 
480 	ddr_perf_event_stop(event, PERF_EF_UPDATE);
481 
482 	ddr_perf_free_counter(pmu, counter);
483 	pmu->active_events--;
484 	hwc->idx = -1;
485 }
486 
487 static void ddr_perf_pmu_enable(struct pmu *pmu)
488 {
489 	struct ddr_pmu *ddr_pmu = to_ddr_pmu(pmu);
490 
491 	/* enable cycle counter if cycle is not active event list */
492 	if (ddr_pmu->events[EVENT_CYCLES_COUNTER] == NULL)
493 		ddr_perf_counter_enable(ddr_pmu,
494 				      EVENT_CYCLES_ID,
495 				      EVENT_CYCLES_COUNTER,
496 				      true);
497 }
498 
499 static void ddr_perf_pmu_disable(struct pmu *pmu)
500 {
501 	struct ddr_pmu *ddr_pmu = to_ddr_pmu(pmu);
502 
503 	if (ddr_pmu->events[EVENT_CYCLES_COUNTER] == NULL)
504 		ddr_perf_counter_enable(ddr_pmu,
505 				      EVENT_CYCLES_ID,
506 				      EVENT_CYCLES_COUNTER,
507 				      false);
508 }
509 
510 static int ddr_perf_init(struct ddr_pmu *pmu, void __iomem *base,
511 			 struct device *dev)
512 {
513 	*pmu = (struct ddr_pmu) {
514 		.pmu = (struct pmu) {
515 			.module	      = THIS_MODULE,
516 			.capabilities = PERF_PMU_CAP_NO_EXCLUDE,
517 			.task_ctx_nr = perf_invalid_context,
518 			.attr_groups = attr_groups,
519 			.event_init  = ddr_perf_event_init,
520 			.add	     = ddr_perf_event_add,
521 			.del	     = ddr_perf_event_del,
522 			.start	     = ddr_perf_event_start,
523 			.stop	     = ddr_perf_event_stop,
524 			.read	     = ddr_perf_event_update,
525 			.pmu_enable  = ddr_perf_pmu_enable,
526 			.pmu_disable = ddr_perf_pmu_disable,
527 		},
528 		.base = base,
529 		.dev = dev,
530 	};
531 
532 	pmu->id = ida_simple_get(&ddr_ida, 0, 0, GFP_KERNEL);
533 	return pmu->id;
534 }
535 
536 static irqreturn_t ddr_perf_irq_handler(int irq, void *p)
537 {
538 	int i;
539 	struct ddr_pmu *pmu = (struct ddr_pmu *) p;
540 	struct perf_event *event, *cycle_event = NULL;
541 
542 	/* all counter will stop if cycle counter disabled */
543 	ddr_perf_counter_enable(pmu,
544 			      EVENT_CYCLES_ID,
545 			      EVENT_CYCLES_COUNTER,
546 			      false);
547 	/*
548 	 * When the cycle counter overflows, all counters are stopped,
549 	 * and an IRQ is raised. If any other counter overflows, it
550 	 * continues counting, and no IRQ is raised.
551 	 *
552 	 * Cycles occur at least 4 times as often as other events, so we
553 	 * can update all events on a cycle counter overflow and not
554 	 * lose events.
555 	 *
556 	 */
557 	for (i = 0; i < NUM_COUNTERS; i++) {
558 
559 		if (!pmu->events[i])
560 			continue;
561 
562 		event = pmu->events[i];
563 
564 		ddr_perf_event_update(event);
565 
566 		if (event->hw.idx == EVENT_CYCLES_COUNTER)
567 			cycle_event = event;
568 	}
569 
570 	ddr_perf_counter_enable(pmu,
571 			      EVENT_CYCLES_ID,
572 			      EVENT_CYCLES_COUNTER,
573 			      true);
574 	if (cycle_event)
575 		ddr_perf_event_update(cycle_event);
576 
577 	return IRQ_HANDLED;
578 }
579 
580 static int ddr_perf_offline_cpu(unsigned int cpu, struct hlist_node *node)
581 {
582 	struct ddr_pmu *pmu = hlist_entry_safe(node, struct ddr_pmu, node);
583 	int target;
584 
585 	if (cpu != pmu->cpu)
586 		return 0;
587 
588 	target = cpumask_any_but(cpu_online_mask, cpu);
589 	if (target >= nr_cpu_ids)
590 		return 0;
591 
592 	perf_pmu_migrate_context(&pmu->pmu, cpu, target);
593 	pmu->cpu = target;
594 
595 	WARN_ON(irq_set_affinity_hint(pmu->irq, cpumask_of(pmu->cpu)));
596 
597 	return 0;
598 }
599 
600 static int ddr_perf_probe(struct platform_device *pdev)
601 {
602 	struct ddr_pmu *pmu;
603 	struct device_node *np;
604 	void __iomem *base;
605 	char *name;
606 	int num;
607 	int ret;
608 	int irq;
609 
610 	base = devm_platform_ioremap_resource(pdev, 0);
611 	if (IS_ERR(base))
612 		return PTR_ERR(base);
613 
614 	np = pdev->dev.of_node;
615 
616 	pmu = devm_kzalloc(&pdev->dev, sizeof(*pmu), GFP_KERNEL);
617 	if (!pmu)
618 		return -ENOMEM;
619 
620 	num = ddr_perf_init(pmu, base, &pdev->dev);
621 
622 	platform_set_drvdata(pdev, pmu);
623 
624 	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, DDR_PERF_DEV_NAME "%d",
625 			      num);
626 	if (!name)
627 		return -ENOMEM;
628 
629 	pmu->devtype_data = of_device_get_match_data(&pdev->dev);
630 
631 	pmu->cpu = raw_smp_processor_id();
632 	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
633 				      DDR_CPUHP_CB_NAME,
634 				      NULL,
635 				      ddr_perf_offline_cpu);
636 
637 	if (ret < 0) {
638 		dev_err(&pdev->dev, "cpuhp_setup_state_multi failed\n");
639 		goto cpuhp_state_err;
640 	}
641 
642 	pmu->cpuhp_state = ret;
643 
644 	/* Register the pmu instance for cpu hotplug */
645 	ret = cpuhp_state_add_instance_nocalls(pmu->cpuhp_state, &pmu->node);
646 	if (ret) {
647 		dev_err(&pdev->dev, "Error %d registering hotplug\n", ret);
648 		goto cpuhp_instance_err;
649 	}
650 
651 	/* Request irq */
652 	irq = of_irq_get(np, 0);
653 	if (irq < 0) {
654 		dev_err(&pdev->dev, "Failed to get irq: %d", irq);
655 		ret = irq;
656 		goto ddr_perf_err;
657 	}
658 
659 	ret = devm_request_irq(&pdev->dev, irq,
660 					ddr_perf_irq_handler,
661 					IRQF_NOBALANCING | IRQF_NO_THREAD,
662 					DDR_CPUHP_CB_NAME,
663 					pmu);
664 	if (ret < 0) {
665 		dev_err(&pdev->dev, "Request irq failed: %d", ret);
666 		goto ddr_perf_err;
667 	}
668 
669 	pmu->irq = irq;
670 	ret = irq_set_affinity_hint(pmu->irq, cpumask_of(pmu->cpu));
671 	if (ret) {
672 		dev_err(pmu->dev, "Failed to set interrupt affinity!\n");
673 		goto ddr_perf_err;
674 	}
675 
676 	ret = perf_pmu_register(&pmu->pmu, name, -1);
677 	if (ret)
678 		goto ddr_perf_err;
679 
680 	return 0;
681 
682 ddr_perf_err:
683 	cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
684 cpuhp_instance_err:
685 	cpuhp_remove_multi_state(pmu->cpuhp_state);
686 cpuhp_state_err:
687 	ida_simple_remove(&ddr_ida, pmu->id);
688 	dev_warn(&pdev->dev, "i.MX8 DDR Perf PMU failed (%d), disabled\n", ret);
689 	return ret;
690 }
691 
692 static int ddr_perf_remove(struct platform_device *pdev)
693 {
694 	struct ddr_pmu *pmu = platform_get_drvdata(pdev);
695 
696 	cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
697 	cpuhp_remove_multi_state(pmu->cpuhp_state);
698 	irq_set_affinity_hint(pmu->irq, NULL);
699 
700 	perf_pmu_unregister(&pmu->pmu);
701 
702 	ida_simple_remove(&ddr_ida, pmu->id);
703 	return 0;
704 }
705 
706 static struct platform_driver imx_ddr_pmu_driver = {
707 	.driver         = {
708 		.name   = "imx-ddr-pmu",
709 		.of_match_table = imx_ddr_pmu_dt_ids,
710 		.suppress_bind_attrs = true,
711 	},
712 	.probe          = ddr_perf_probe,
713 	.remove         = ddr_perf_remove,
714 };
715 
716 module_platform_driver(imx_ddr_pmu_driver);
717 MODULE_LICENSE("GPL v2");
718