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		(0xFFU << 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 	const char *identifier;	/* system PMU identifier for userspace */
54 };
55 
56 static const struct fsl_ddr_devtype_data imx8_devtype_data;
57 
58 static const struct fsl_ddr_devtype_data imx8m_devtype_data = {
59 	.quirks = DDR_CAP_AXI_ID_FILTER,
60 };
61 
62 static const struct fsl_ddr_devtype_data imx8mq_devtype_data = {
63 	.quirks = DDR_CAP_AXI_ID_FILTER,
64 	.identifier = "i.MX8MQ",
65 };
66 
67 static const struct fsl_ddr_devtype_data imx8mm_devtype_data = {
68 	.quirks = DDR_CAP_AXI_ID_FILTER,
69 	.identifier = "i.MX8MM",
70 };
71 
72 static const struct fsl_ddr_devtype_data imx8mn_devtype_data = {
73 	.quirks = DDR_CAP_AXI_ID_FILTER,
74 	.identifier = "i.MX8MN",
75 };
76 
77 static const struct fsl_ddr_devtype_data imx8mp_devtype_data = {
78 	.quirks = DDR_CAP_AXI_ID_FILTER_ENHANCED,
79 	.identifier = "i.MX8MP",
80 };
81 
82 static const struct of_device_id imx_ddr_pmu_dt_ids[] = {
83 	{ .compatible = "fsl,imx8-ddr-pmu", .data = &imx8_devtype_data},
84 	{ .compatible = "fsl,imx8m-ddr-pmu", .data = &imx8m_devtype_data},
85 	{ .compatible = "fsl,imx8mq-ddr-pmu", .data = &imx8mq_devtype_data},
86 	{ .compatible = "fsl,imx8mm-ddr-pmu", .data = &imx8mm_devtype_data},
87 	{ .compatible = "fsl,imx8mn-ddr-pmu", .data = &imx8mn_devtype_data},
88 	{ .compatible = "fsl,imx8mp-ddr-pmu", .data = &imx8mp_devtype_data},
89 	{ /* sentinel */ }
90 };
91 MODULE_DEVICE_TABLE(of, imx_ddr_pmu_dt_ids);
92 
93 struct ddr_pmu {
94 	struct pmu pmu;
95 	void __iomem *base;
96 	unsigned int cpu;
97 	struct	hlist_node node;
98 	struct	device *dev;
99 	struct perf_event *events[NUM_COUNTERS];
100 	int active_events;
101 	enum cpuhp_state cpuhp_state;
102 	const struct fsl_ddr_devtype_data *devtype_data;
103 	int irq;
104 	int id;
105 };
106 
107 static ssize_t ddr_perf_identifier_show(struct device *dev,
108 					struct device_attribute *attr,
109 					char *page)
110 {
111 	struct ddr_pmu *pmu = dev_get_drvdata(dev);
112 
113 	return sysfs_emit(page, "%s\n", pmu->devtype_data->identifier);
114 }
115 
116 static umode_t ddr_perf_identifier_attr_visible(struct kobject *kobj,
117 						struct attribute *attr,
118 						int n)
119 {
120 	struct device *dev = kobj_to_dev(kobj);
121 	struct ddr_pmu *pmu = dev_get_drvdata(dev);
122 
123 	if (!pmu->devtype_data->identifier)
124 		return 0;
125 	return attr->mode;
126 };
127 
128 static struct device_attribute ddr_perf_identifier_attr =
129 	__ATTR(identifier, 0444, ddr_perf_identifier_show, NULL);
130 
131 static struct attribute *ddr_perf_identifier_attrs[] = {
132 	&ddr_perf_identifier_attr.attr,
133 	NULL,
134 };
135 
136 static const struct attribute_group ddr_perf_identifier_attr_group = {
137 	.attrs = ddr_perf_identifier_attrs,
138 	.is_visible = ddr_perf_identifier_attr_visible,
139 };
140 
141 enum ddr_perf_filter_capabilities {
142 	PERF_CAP_AXI_ID_FILTER = 0,
143 	PERF_CAP_AXI_ID_FILTER_ENHANCED,
144 	PERF_CAP_AXI_ID_FEAT_MAX,
145 };
146 
147 static u32 ddr_perf_filter_cap_get(struct ddr_pmu *pmu, int cap)
148 {
149 	u32 quirks = pmu->devtype_data->quirks;
150 
151 	switch (cap) {
152 	case PERF_CAP_AXI_ID_FILTER:
153 		return !!(quirks & DDR_CAP_AXI_ID_FILTER);
154 	case PERF_CAP_AXI_ID_FILTER_ENHANCED:
155 		quirks &= DDR_CAP_AXI_ID_FILTER_ENHANCED;
156 		return quirks == DDR_CAP_AXI_ID_FILTER_ENHANCED;
157 	default:
158 		WARN(1, "unknown filter cap %d\n", cap);
159 	}
160 
161 	return 0;
162 }
163 
164 static ssize_t ddr_perf_filter_cap_show(struct device *dev,
165 					struct device_attribute *attr,
166 					char *buf)
167 {
168 	struct ddr_pmu *pmu = dev_get_drvdata(dev);
169 	struct dev_ext_attribute *ea =
170 		container_of(attr, struct dev_ext_attribute, attr);
171 	int cap = (long)ea->var;
172 
173 	return sysfs_emit(buf, "%u\n", ddr_perf_filter_cap_get(pmu, cap));
174 }
175 
176 #define PERF_EXT_ATTR_ENTRY(_name, _func, _var)				\
177 	(&((struct dev_ext_attribute) {					\
178 		__ATTR(_name, 0444, _func, NULL), (void *)_var		\
179 	}).attr.attr)
180 
181 #define PERF_FILTER_EXT_ATTR_ENTRY(_name, _var)				\
182 	PERF_EXT_ATTR_ENTRY(_name, ddr_perf_filter_cap_show, _var)
183 
184 static struct attribute *ddr_perf_filter_cap_attr[] = {
185 	PERF_FILTER_EXT_ATTR_ENTRY(filter, PERF_CAP_AXI_ID_FILTER),
186 	PERF_FILTER_EXT_ATTR_ENTRY(enhanced_filter, PERF_CAP_AXI_ID_FILTER_ENHANCED),
187 	NULL,
188 };
189 
190 static const struct attribute_group ddr_perf_filter_cap_attr_group = {
191 	.name = "caps",
192 	.attrs = ddr_perf_filter_cap_attr,
193 };
194 
195 static ssize_t ddr_perf_cpumask_show(struct device *dev,
196 				struct device_attribute *attr, char *buf)
197 {
198 	struct ddr_pmu *pmu = dev_get_drvdata(dev);
199 
200 	return cpumap_print_to_pagebuf(true, buf, cpumask_of(pmu->cpu));
201 }
202 
203 static struct device_attribute ddr_perf_cpumask_attr =
204 	__ATTR(cpumask, 0444, ddr_perf_cpumask_show, NULL);
205 
206 static struct attribute *ddr_perf_cpumask_attrs[] = {
207 	&ddr_perf_cpumask_attr.attr,
208 	NULL,
209 };
210 
211 static const struct attribute_group ddr_perf_cpumask_attr_group = {
212 	.attrs = ddr_perf_cpumask_attrs,
213 };
214 
215 static ssize_t
216 ddr_pmu_event_show(struct device *dev, struct device_attribute *attr,
217 		   char *page)
218 {
219 	struct perf_pmu_events_attr *pmu_attr;
220 
221 	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
222 	return sysfs_emit(page, "event=0x%02llx\n", pmu_attr->id);
223 }
224 
225 #define IMX8_DDR_PMU_EVENT_ATTR(_name, _id)		\
226 	PMU_EVENT_ATTR_ID(_name, ddr_pmu_event_show, _id)
227 
228 static struct attribute *ddr_perf_events_attrs[] = {
229 	IMX8_DDR_PMU_EVENT_ATTR(cycles, EVENT_CYCLES_ID),
230 	IMX8_DDR_PMU_EVENT_ATTR(selfresh, 0x01),
231 	IMX8_DDR_PMU_EVENT_ATTR(read-accesses, 0x04),
232 	IMX8_DDR_PMU_EVENT_ATTR(write-accesses, 0x05),
233 	IMX8_DDR_PMU_EVENT_ATTR(read-queue-depth, 0x08),
234 	IMX8_DDR_PMU_EVENT_ATTR(write-queue-depth, 0x09),
235 	IMX8_DDR_PMU_EVENT_ATTR(lp-read-credit-cnt, 0x10),
236 	IMX8_DDR_PMU_EVENT_ATTR(hp-read-credit-cnt, 0x11),
237 	IMX8_DDR_PMU_EVENT_ATTR(write-credit-cnt, 0x12),
238 	IMX8_DDR_PMU_EVENT_ATTR(read-command, 0x20),
239 	IMX8_DDR_PMU_EVENT_ATTR(write-command, 0x21),
240 	IMX8_DDR_PMU_EVENT_ATTR(read-modify-write-command, 0x22),
241 	IMX8_DDR_PMU_EVENT_ATTR(hp-read, 0x23),
242 	IMX8_DDR_PMU_EVENT_ATTR(hp-req-nocredit, 0x24),
243 	IMX8_DDR_PMU_EVENT_ATTR(hp-xact-credit, 0x25),
244 	IMX8_DDR_PMU_EVENT_ATTR(lp-req-nocredit, 0x26),
245 	IMX8_DDR_PMU_EVENT_ATTR(lp-xact-credit, 0x27),
246 	IMX8_DDR_PMU_EVENT_ATTR(wr-xact-credit, 0x29),
247 	IMX8_DDR_PMU_EVENT_ATTR(read-cycles, 0x2a),
248 	IMX8_DDR_PMU_EVENT_ATTR(write-cycles, 0x2b),
249 	IMX8_DDR_PMU_EVENT_ATTR(read-write-transition, 0x30),
250 	IMX8_DDR_PMU_EVENT_ATTR(precharge, 0x31),
251 	IMX8_DDR_PMU_EVENT_ATTR(activate, 0x32),
252 	IMX8_DDR_PMU_EVENT_ATTR(load-mode, 0x33),
253 	IMX8_DDR_PMU_EVENT_ATTR(perf-mwr, 0x34),
254 	IMX8_DDR_PMU_EVENT_ATTR(read, 0x35),
255 	IMX8_DDR_PMU_EVENT_ATTR(read-activate, 0x36),
256 	IMX8_DDR_PMU_EVENT_ATTR(refresh, 0x37),
257 	IMX8_DDR_PMU_EVENT_ATTR(write, 0x38),
258 	IMX8_DDR_PMU_EVENT_ATTR(raw-hazard, 0x39),
259 	IMX8_DDR_PMU_EVENT_ATTR(axid-read, 0x41),
260 	IMX8_DDR_PMU_EVENT_ATTR(axid-write, 0x42),
261 	NULL,
262 };
263 
264 static const struct attribute_group ddr_perf_events_attr_group = {
265 	.name = "events",
266 	.attrs = ddr_perf_events_attrs,
267 };
268 
269 PMU_FORMAT_ATTR(event, "config:0-7");
270 PMU_FORMAT_ATTR(axi_id, "config1:0-15");
271 PMU_FORMAT_ATTR(axi_mask, "config1:16-31");
272 
273 static struct attribute *ddr_perf_format_attrs[] = {
274 	&format_attr_event.attr,
275 	&format_attr_axi_id.attr,
276 	&format_attr_axi_mask.attr,
277 	NULL,
278 };
279 
280 static const struct attribute_group ddr_perf_format_attr_group = {
281 	.name = "format",
282 	.attrs = ddr_perf_format_attrs,
283 };
284 
285 static const struct attribute_group *attr_groups[] = {
286 	&ddr_perf_events_attr_group,
287 	&ddr_perf_format_attr_group,
288 	&ddr_perf_cpumask_attr_group,
289 	&ddr_perf_filter_cap_attr_group,
290 	&ddr_perf_identifier_attr_group,
291 	NULL,
292 };
293 
294 static bool ddr_perf_is_filtered(struct perf_event *event)
295 {
296 	return event->attr.config == 0x41 || event->attr.config == 0x42;
297 }
298 
299 static u32 ddr_perf_filter_val(struct perf_event *event)
300 {
301 	return event->attr.config1;
302 }
303 
304 static bool ddr_perf_filters_compatible(struct perf_event *a,
305 					struct perf_event *b)
306 {
307 	if (!ddr_perf_is_filtered(a))
308 		return true;
309 	if (!ddr_perf_is_filtered(b))
310 		return true;
311 	return ddr_perf_filter_val(a) == ddr_perf_filter_val(b);
312 }
313 
314 static bool ddr_perf_is_enhanced_filtered(struct perf_event *event)
315 {
316 	unsigned int filt;
317 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
318 
319 	filt = pmu->devtype_data->quirks & DDR_CAP_AXI_ID_FILTER_ENHANCED;
320 	return (filt == DDR_CAP_AXI_ID_FILTER_ENHANCED) &&
321 		ddr_perf_is_filtered(event);
322 }
323 
324 static u32 ddr_perf_alloc_counter(struct ddr_pmu *pmu, int event)
325 {
326 	int i;
327 
328 	/*
329 	 * Always map cycle event to counter 0
330 	 * Cycles counter is dedicated for cycle event
331 	 * can't used for the other events
332 	 */
333 	if (event == EVENT_CYCLES_ID) {
334 		if (pmu->events[EVENT_CYCLES_COUNTER] == NULL)
335 			return EVENT_CYCLES_COUNTER;
336 		else
337 			return -ENOENT;
338 	}
339 
340 	for (i = 1; i < NUM_COUNTERS; i++) {
341 		if (pmu->events[i] == NULL)
342 			return i;
343 	}
344 
345 	return -ENOENT;
346 }
347 
348 static void ddr_perf_free_counter(struct ddr_pmu *pmu, int counter)
349 {
350 	pmu->events[counter] = NULL;
351 }
352 
353 static u32 ddr_perf_read_counter(struct ddr_pmu *pmu, int counter)
354 {
355 	struct perf_event *event = pmu->events[counter];
356 	void __iomem *base = pmu->base;
357 
358 	/*
359 	 * return bytes instead of bursts from ddr transaction for
360 	 * axid-read and axid-write event if PMU core supports enhanced
361 	 * filter.
362 	 */
363 	base += ddr_perf_is_enhanced_filtered(event) ? COUNTER_DPCR1 :
364 						       COUNTER_READ;
365 	return readl_relaxed(base + counter * 4);
366 }
367 
368 static int ddr_perf_event_init(struct perf_event *event)
369 {
370 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
371 	struct hw_perf_event *hwc = &event->hw;
372 	struct perf_event *sibling;
373 
374 	if (event->attr.type != event->pmu->type)
375 		return -ENOENT;
376 
377 	if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
378 		return -EOPNOTSUPP;
379 
380 	if (event->cpu < 0) {
381 		dev_warn(pmu->dev, "Can't provide per-task data!\n");
382 		return -EOPNOTSUPP;
383 	}
384 
385 	/*
386 	 * We must NOT create groups containing mixed PMUs, although software
387 	 * events are acceptable (for example to create a CCN group
388 	 * periodically read when a hrtimer aka cpu-clock leader triggers).
389 	 */
390 	if (event->group_leader->pmu != event->pmu &&
391 			!is_software_event(event->group_leader))
392 		return -EINVAL;
393 
394 	if (pmu->devtype_data->quirks & DDR_CAP_AXI_ID_FILTER) {
395 		if (!ddr_perf_filters_compatible(event, event->group_leader))
396 			return -EINVAL;
397 		for_each_sibling_event(sibling, event->group_leader) {
398 			if (!ddr_perf_filters_compatible(event, sibling))
399 				return -EINVAL;
400 		}
401 	}
402 
403 	for_each_sibling_event(sibling, event->group_leader) {
404 		if (sibling->pmu != event->pmu &&
405 				!is_software_event(sibling))
406 			return -EINVAL;
407 	}
408 
409 	event->cpu = pmu->cpu;
410 	hwc->idx = -1;
411 
412 	return 0;
413 }
414 
415 static void ddr_perf_counter_enable(struct ddr_pmu *pmu, int config,
416 				  int counter, bool enable)
417 {
418 	u8 reg = counter * 4 + COUNTER_CNTL;
419 	int val;
420 
421 	if (enable) {
422 		/*
423 		 * cycle counter is special which should firstly write 0 then
424 		 * write 1 into CLEAR bit to clear it. Other counters only
425 		 * need write 0 into CLEAR bit and it turns out to be 1 by
426 		 * hardware. Below enable flow is harmless for all counters.
427 		 */
428 		writel(0, pmu->base + reg);
429 		val = CNTL_EN | CNTL_CLEAR;
430 		val |= FIELD_PREP(CNTL_CSV_MASK, config);
431 		writel(val, pmu->base + reg);
432 	} else {
433 		/* Disable counter */
434 		val = readl_relaxed(pmu->base + reg) & CNTL_EN_MASK;
435 		writel(val, pmu->base + reg);
436 	}
437 }
438 
439 static bool ddr_perf_counter_overflow(struct ddr_pmu *pmu, int counter)
440 {
441 	int val;
442 
443 	val = readl_relaxed(pmu->base + counter * 4 + COUNTER_CNTL);
444 
445 	return val & CNTL_OVER;
446 }
447 
448 static void ddr_perf_counter_clear(struct ddr_pmu *pmu, int counter)
449 {
450 	u8 reg = counter * 4 + COUNTER_CNTL;
451 	int val;
452 
453 	val = readl_relaxed(pmu->base + reg);
454 	val &= ~CNTL_CLEAR;
455 	writel(val, pmu->base + reg);
456 
457 	val |= CNTL_CLEAR;
458 	writel(val, pmu->base + reg);
459 }
460 
461 static void ddr_perf_event_update(struct perf_event *event)
462 {
463 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
464 	struct hw_perf_event *hwc = &event->hw;
465 	u64 new_raw_count;
466 	int counter = hwc->idx;
467 	int ret;
468 
469 	new_raw_count = ddr_perf_read_counter(pmu, counter);
470 	local64_add(new_raw_count, &event->count);
471 
472 	/*
473 	 * For legacy SoCs: event counter continue counting when overflow,
474 	 *                  no need to clear the counter.
475 	 * For new SoCs: event counter stop counting when overflow, need
476 	 *               clear counter to let it count again.
477 	 */
478 	if (counter != EVENT_CYCLES_COUNTER) {
479 		ret = ddr_perf_counter_overflow(pmu, counter);
480 		if (ret)
481 			dev_warn_ratelimited(pmu->dev,  "events lost due to counter overflow (config 0x%llx)\n",
482 					     event->attr.config);
483 	}
484 
485 	/* clear counter every time for both cycle counter and event counter */
486 	ddr_perf_counter_clear(pmu, counter);
487 }
488 
489 static void ddr_perf_event_start(struct perf_event *event, int flags)
490 {
491 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
492 	struct hw_perf_event *hwc = &event->hw;
493 	int counter = hwc->idx;
494 
495 	local64_set(&hwc->prev_count, 0);
496 
497 	ddr_perf_counter_enable(pmu, event->attr.config, counter, true);
498 
499 	hwc->state = 0;
500 }
501 
502 static int ddr_perf_event_add(struct perf_event *event, int flags)
503 {
504 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
505 	struct hw_perf_event *hwc = &event->hw;
506 	int counter;
507 	int cfg = event->attr.config;
508 	int cfg1 = event->attr.config1;
509 
510 	if (pmu->devtype_data->quirks & DDR_CAP_AXI_ID_FILTER) {
511 		int i;
512 
513 		for (i = 1; i < NUM_COUNTERS; i++) {
514 			if (pmu->events[i] &&
515 			    !ddr_perf_filters_compatible(event, pmu->events[i]))
516 				return -EINVAL;
517 		}
518 
519 		if (ddr_perf_is_filtered(event)) {
520 			/* revert axi id masking(axi_mask) value */
521 			cfg1 ^= AXI_MASKING_REVERT;
522 			writel(cfg1, pmu->base + COUNTER_DPCR1);
523 		}
524 	}
525 
526 	counter = ddr_perf_alloc_counter(pmu, cfg);
527 	if (counter < 0) {
528 		dev_dbg(pmu->dev, "There are not enough counters\n");
529 		return -EOPNOTSUPP;
530 	}
531 
532 	pmu->events[counter] = event;
533 	pmu->active_events++;
534 	hwc->idx = counter;
535 
536 	hwc->state |= PERF_HES_STOPPED;
537 
538 	if (flags & PERF_EF_START)
539 		ddr_perf_event_start(event, flags);
540 
541 	return 0;
542 }
543 
544 static void ddr_perf_event_stop(struct perf_event *event, int flags)
545 {
546 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
547 	struct hw_perf_event *hwc = &event->hw;
548 	int counter = hwc->idx;
549 
550 	ddr_perf_counter_enable(pmu, event->attr.config, counter, false);
551 	ddr_perf_event_update(event);
552 
553 	hwc->state |= PERF_HES_STOPPED;
554 }
555 
556 static void ddr_perf_event_del(struct perf_event *event, int flags)
557 {
558 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
559 	struct hw_perf_event *hwc = &event->hw;
560 	int counter = hwc->idx;
561 
562 	ddr_perf_event_stop(event, PERF_EF_UPDATE);
563 
564 	ddr_perf_free_counter(pmu, counter);
565 	pmu->active_events--;
566 	hwc->idx = -1;
567 }
568 
569 static void ddr_perf_pmu_enable(struct pmu *pmu)
570 {
571 	struct ddr_pmu *ddr_pmu = to_ddr_pmu(pmu);
572 
573 	/* enable cycle counter if cycle is not active event list */
574 	if (ddr_pmu->events[EVENT_CYCLES_COUNTER] == NULL)
575 		ddr_perf_counter_enable(ddr_pmu,
576 				      EVENT_CYCLES_ID,
577 				      EVENT_CYCLES_COUNTER,
578 				      true);
579 }
580 
581 static void ddr_perf_pmu_disable(struct pmu *pmu)
582 {
583 	struct ddr_pmu *ddr_pmu = to_ddr_pmu(pmu);
584 
585 	if (ddr_pmu->events[EVENT_CYCLES_COUNTER] == NULL)
586 		ddr_perf_counter_enable(ddr_pmu,
587 				      EVENT_CYCLES_ID,
588 				      EVENT_CYCLES_COUNTER,
589 				      false);
590 }
591 
592 static int ddr_perf_init(struct ddr_pmu *pmu, void __iomem *base,
593 			 struct device *dev)
594 {
595 	*pmu = (struct ddr_pmu) {
596 		.pmu = (struct pmu) {
597 			.module	      = THIS_MODULE,
598 			.capabilities = PERF_PMU_CAP_NO_EXCLUDE,
599 			.task_ctx_nr = perf_invalid_context,
600 			.attr_groups = attr_groups,
601 			.event_init  = ddr_perf_event_init,
602 			.add	     = ddr_perf_event_add,
603 			.del	     = ddr_perf_event_del,
604 			.start	     = ddr_perf_event_start,
605 			.stop	     = ddr_perf_event_stop,
606 			.read	     = ddr_perf_event_update,
607 			.pmu_enable  = ddr_perf_pmu_enable,
608 			.pmu_disable = ddr_perf_pmu_disable,
609 		},
610 		.base = base,
611 		.dev = dev,
612 	};
613 
614 	pmu->id = ida_simple_get(&ddr_ida, 0, 0, GFP_KERNEL);
615 	return pmu->id;
616 }
617 
618 static irqreturn_t ddr_perf_irq_handler(int irq, void *p)
619 {
620 	int i;
621 	struct ddr_pmu *pmu = (struct ddr_pmu *) p;
622 	struct perf_event *event;
623 
624 	/* all counter will stop if cycle counter disabled */
625 	ddr_perf_counter_enable(pmu,
626 			      EVENT_CYCLES_ID,
627 			      EVENT_CYCLES_COUNTER,
628 			      false);
629 	/*
630 	 * When the cycle counter overflows, all counters are stopped,
631 	 * and an IRQ is raised. If any other counter overflows, it
632 	 * continues counting, and no IRQ is raised. But for new SoCs,
633 	 * such as i.MX8MP, event counter would stop when overflow, so
634 	 * we need use cycle counter to stop overflow of event counter.
635 	 *
636 	 * Cycles occur at least 4 times as often as other events, so we
637 	 * can update all events on a cycle counter overflow and not
638 	 * lose events.
639 	 *
640 	 */
641 	for (i = 0; i < NUM_COUNTERS; i++) {
642 
643 		if (!pmu->events[i])
644 			continue;
645 
646 		event = pmu->events[i];
647 
648 		ddr_perf_event_update(event);
649 	}
650 
651 	ddr_perf_counter_enable(pmu,
652 			      EVENT_CYCLES_ID,
653 			      EVENT_CYCLES_COUNTER,
654 			      true);
655 
656 	return IRQ_HANDLED;
657 }
658 
659 static int ddr_perf_offline_cpu(unsigned int cpu, struct hlist_node *node)
660 {
661 	struct ddr_pmu *pmu = hlist_entry_safe(node, struct ddr_pmu, node);
662 	int target;
663 
664 	if (cpu != pmu->cpu)
665 		return 0;
666 
667 	target = cpumask_any_but(cpu_online_mask, cpu);
668 	if (target >= nr_cpu_ids)
669 		return 0;
670 
671 	perf_pmu_migrate_context(&pmu->pmu, cpu, target);
672 	pmu->cpu = target;
673 
674 	WARN_ON(irq_set_affinity(pmu->irq, cpumask_of(pmu->cpu)));
675 
676 	return 0;
677 }
678 
679 static int ddr_perf_probe(struct platform_device *pdev)
680 {
681 	struct ddr_pmu *pmu;
682 	struct device_node *np;
683 	void __iomem *base;
684 	char *name;
685 	int num;
686 	int ret;
687 	int irq;
688 
689 	base = devm_platform_ioremap_resource(pdev, 0);
690 	if (IS_ERR(base))
691 		return PTR_ERR(base);
692 
693 	np = pdev->dev.of_node;
694 
695 	pmu = devm_kzalloc(&pdev->dev, sizeof(*pmu), GFP_KERNEL);
696 	if (!pmu)
697 		return -ENOMEM;
698 
699 	num = ddr_perf_init(pmu, base, &pdev->dev);
700 
701 	platform_set_drvdata(pdev, pmu);
702 
703 	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, DDR_PERF_DEV_NAME "%d",
704 			      num);
705 	if (!name) {
706 		ret = -ENOMEM;
707 		goto cpuhp_state_err;
708 	}
709 
710 	pmu->devtype_data = of_device_get_match_data(&pdev->dev);
711 
712 	pmu->cpu = raw_smp_processor_id();
713 	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
714 				      DDR_CPUHP_CB_NAME,
715 				      NULL,
716 				      ddr_perf_offline_cpu);
717 
718 	if (ret < 0) {
719 		dev_err(&pdev->dev, "cpuhp_setup_state_multi failed\n");
720 		goto cpuhp_state_err;
721 	}
722 
723 	pmu->cpuhp_state = ret;
724 
725 	/* Register the pmu instance for cpu hotplug */
726 	ret = cpuhp_state_add_instance_nocalls(pmu->cpuhp_state, &pmu->node);
727 	if (ret) {
728 		dev_err(&pdev->dev, "Error %d registering hotplug\n", ret);
729 		goto cpuhp_instance_err;
730 	}
731 
732 	/* Request irq */
733 	irq = of_irq_get(np, 0);
734 	if (irq < 0) {
735 		dev_err(&pdev->dev, "Failed to get irq: %d", irq);
736 		ret = irq;
737 		goto ddr_perf_err;
738 	}
739 
740 	ret = devm_request_irq(&pdev->dev, irq,
741 					ddr_perf_irq_handler,
742 					IRQF_NOBALANCING | IRQF_NO_THREAD,
743 					DDR_CPUHP_CB_NAME,
744 					pmu);
745 	if (ret < 0) {
746 		dev_err(&pdev->dev, "Request irq failed: %d", ret);
747 		goto ddr_perf_err;
748 	}
749 
750 	pmu->irq = irq;
751 	ret = irq_set_affinity(pmu->irq, cpumask_of(pmu->cpu));
752 	if (ret) {
753 		dev_err(pmu->dev, "Failed to set interrupt affinity!\n");
754 		goto ddr_perf_err;
755 	}
756 
757 	ret = perf_pmu_register(&pmu->pmu, name, -1);
758 	if (ret)
759 		goto ddr_perf_err;
760 
761 	return 0;
762 
763 ddr_perf_err:
764 	cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
765 cpuhp_instance_err:
766 	cpuhp_remove_multi_state(pmu->cpuhp_state);
767 cpuhp_state_err:
768 	ida_simple_remove(&ddr_ida, pmu->id);
769 	dev_warn(&pdev->dev, "i.MX8 DDR Perf PMU failed (%d), disabled\n", ret);
770 	return ret;
771 }
772 
773 static int ddr_perf_remove(struct platform_device *pdev)
774 {
775 	struct ddr_pmu *pmu = platform_get_drvdata(pdev);
776 
777 	cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
778 	cpuhp_remove_multi_state(pmu->cpuhp_state);
779 
780 	perf_pmu_unregister(&pmu->pmu);
781 
782 	ida_simple_remove(&ddr_ida, pmu->id);
783 	return 0;
784 }
785 
786 static struct platform_driver imx_ddr_pmu_driver = {
787 	.driver         = {
788 		.name   = "imx-ddr-pmu",
789 		.of_match_table = imx_ddr_pmu_dt_ids,
790 		.suppress_bind_attrs = true,
791 	},
792 	.probe          = ddr_perf_probe,
793 	.remove         = ddr_perf_remove,
794 };
795 
796 module_platform_driver(imx_ddr_pmu_driver);
797 MODULE_LICENSE("GPL v2");
798