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_irq.h>
14 #include <linux/perf_event.h>
15 #include <linux/platform_device.h>
16 #include <linux/slab.h>
17 
18 #define COUNTER_CNTL		0x0
19 #define COUNTER_READ		0x20
20 
21 #define COUNTER_DPCR1		0x30
22 
23 #define CNTL_OVER		0x1
24 #define CNTL_CLEAR		0x2
25 #define CNTL_EN			0x4
26 #define CNTL_EN_MASK		0xFFFFFFFB
27 #define CNTL_CLEAR_MASK		0xFFFFFFFD
28 #define CNTL_OVER_MASK		0xFFFFFFFE
29 
30 #define CNTL_CSV_SHIFT		24
31 #define CNTL_CSV_MASK		(0xFFU << CNTL_CSV_SHIFT)
32 
33 #define EVENT_CYCLES_ID		0
34 #define EVENT_CYCLES_COUNTER	0
35 #define NUM_COUNTERS		4
36 
37 #define AXI_MASKING_REVERT	0xffff0000	/* AXI_MASKING(MSB 16bits) + AXI_ID(LSB 16bits) */
38 
39 #define to_ddr_pmu(p)		container_of(p, struct ddr_pmu, pmu)
40 
41 #define DDR_PERF_DEV_NAME	"imx8_ddr"
42 #define DDR_CPUHP_CB_NAME	DDR_PERF_DEV_NAME "_perf_pmu"
43 
44 static DEFINE_IDA(ddr_ida);
45 
46 /* DDR Perf hardware feature */
47 #define DDR_CAP_AXI_ID_FILTER			0x1     /* support AXI ID filter */
48 #define DDR_CAP_AXI_ID_FILTER_ENHANCED		0x3     /* support enhanced AXI ID filter */
49 
50 struct fsl_ddr_devtype_data {
51 	unsigned int quirks;    /* quirks needed for different DDR Perf core */
52 	const char *identifier;	/* system PMU identifier for userspace */
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 imx8mq_devtype_data = {
62 	.quirks = DDR_CAP_AXI_ID_FILTER,
63 	.identifier = "i.MX8MQ",
64 };
65 
66 static const struct fsl_ddr_devtype_data imx8mm_devtype_data = {
67 	.quirks = DDR_CAP_AXI_ID_FILTER,
68 	.identifier = "i.MX8MM",
69 };
70 
71 static const struct fsl_ddr_devtype_data imx8mn_devtype_data = {
72 	.quirks = DDR_CAP_AXI_ID_FILTER,
73 	.identifier = "i.MX8MN",
74 };
75 
76 static const struct fsl_ddr_devtype_data imx8mp_devtype_data = {
77 	.quirks = DDR_CAP_AXI_ID_FILTER_ENHANCED,
78 	.identifier = "i.MX8MP",
79 };
80 
81 static const struct of_device_id imx_ddr_pmu_dt_ids[] = {
82 	{ .compatible = "fsl,imx8-ddr-pmu", .data = &imx8_devtype_data},
83 	{ .compatible = "fsl,imx8m-ddr-pmu", .data = &imx8m_devtype_data},
84 	{ .compatible = "fsl,imx8mq-ddr-pmu", .data = &imx8mq_devtype_data},
85 	{ .compatible = "fsl,imx8mm-ddr-pmu", .data = &imx8mm_devtype_data},
86 	{ .compatible = "fsl,imx8mn-ddr-pmu", .data = &imx8mn_devtype_data},
87 	{ .compatible = "fsl,imx8mp-ddr-pmu", .data = &imx8mp_devtype_data},
88 	{ /* sentinel */ }
89 };
90 MODULE_DEVICE_TABLE(of, imx_ddr_pmu_dt_ids);
91 
92 struct ddr_pmu {
93 	struct pmu pmu;
94 	void __iomem *base;
95 	unsigned int cpu;
96 	struct	hlist_node node;
97 	struct	device *dev;
98 	struct perf_event *events[NUM_COUNTERS];
99 	enum cpuhp_state cpuhp_state;
100 	const struct fsl_ddr_devtype_data *devtype_data;
101 	int irq;
102 	int id;
103 };
104 
105 static ssize_t ddr_perf_identifier_show(struct device *dev,
106 					struct device_attribute *attr,
107 					char *page)
108 {
109 	struct ddr_pmu *pmu = dev_get_drvdata(dev);
110 
111 	return sysfs_emit(page, "%s\n", pmu->devtype_data->identifier);
112 }
113 
114 static umode_t ddr_perf_identifier_attr_visible(struct kobject *kobj,
115 						struct attribute *attr,
116 						int n)
117 {
118 	struct device *dev = kobj_to_dev(kobj);
119 	struct ddr_pmu *pmu = dev_get_drvdata(dev);
120 
121 	if (!pmu->devtype_data->identifier)
122 		return 0;
123 	return attr->mode;
124 };
125 
126 static struct device_attribute ddr_perf_identifier_attr =
127 	__ATTR(identifier, 0444, ddr_perf_identifier_show, NULL);
128 
129 static struct attribute *ddr_perf_identifier_attrs[] = {
130 	&ddr_perf_identifier_attr.attr,
131 	NULL,
132 };
133 
134 static const struct attribute_group ddr_perf_identifier_attr_group = {
135 	.attrs = ddr_perf_identifier_attrs,
136 	.is_visible = ddr_perf_identifier_attr_visible,
137 };
138 
139 enum ddr_perf_filter_capabilities {
140 	PERF_CAP_AXI_ID_FILTER = 0,
141 	PERF_CAP_AXI_ID_FILTER_ENHANCED,
142 	PERF_CAP_AXI_ID_FEAT_MAX,
143 };
144 
145 static u32 ddr_perf_filter_cap_get(struct ddr_pmu *pmu, int cap)
146 {
147 	u32 quirks = pmu->devtype_data->quirks;
148 
149 	switch (cap) {
150 	case PERF_CAP_AXI_ID_FILTER:
151 		return !!(quirks & DDR_CAP_AXI_ID_FILTER);
152 	case PERF_CAP_AXI_ID_FILTER_ENHANCED:
153 		quirks &= DDR_CAP_AXI_ID_FILTER_ENHANCED;
154 		return quirks == DDR_CAP_AXI_ID_FILTER_ENHANCED;
155 	default:
156 		WARN(1, "unknown filter cap %d\n", cap);
157 	}
158 
159 	return 0;
160 }
161 
162 static ssize_t ddr_perf_filter_cap_show(struct device *dev,
163 					struct device_attribute *attr,
164 					char *buf)
165 {
166 	struct ddr_pmu *pmu = dev_get_drvdata(dev);
167 	struct dev_ext_attribute *ea =
168 		container_of(attr, struct dev_ext_attribute, attr);
169 	int cap = (long)ea->var;
170 
171 	return sysfs_emit(buf, "%u\n", ddr_perf_filter_cap_get(pmu, cap));
172 }
173 
174 #define PERF_EXT_ATTR_ENTRY(_name, _func, _var)				\
175 	(&((struct dev_ext_attribute) {					\
176 		__ATTR(_name, 0444, _func, NULL), (void *)_var		\
177 	}).attr.attr)
178 
179 #define PERF_FILTER_EXT_ATTR_ENTRY(_name, _var)				\
180 	PERF_EXT_ATTR_ENTRY(_name, ddr_perf_filter_cap_show, _var)
181 
182 static struct attribute *ddr_perf_filter_cap_attr[] = {
183 	PERF_FILTER_EXT_ATTR_ENTRY(filter, PERF_CAP_AXI_ID_FILTER),
184 	PERF_FILTER_EXT_ATTR_ENTRY(enhanced_filter, PERF_CAP_AXI_ID_FILTER_ENHANCED),
185 	NULL,
186 };
187 
188 static const struct attribute_group ddr_perf_filter_cap_attr_group = {
189 	.name = "caps",
190 	.attrs = ddr_perf_filter_cap_attr,
191 };
192 
193 static ssize_t ddr_perf_cpumask_show(struct device *dev,
194 				struct device_attribute *attr, char *buf)
195 {
196 	struct ddr_pmu *pmu = dev_get_drvdata(dev);
197 
198 	return cpumap_print_to_pagebuf(true, buf, cpumask_of(pmu->cpu));
199 }
200 
201 static struct device_attribute ddr_perf_cpumask_attr =
202 	__ATTR(cpumask, 0444, ddr_perf_cpumask_show, NULL);
203 
204 static struct attribute *ddr_perf_cpumask_attrs[] = {
205 	&ddr_perf_cpumask_attr.attr,
206 	NULL,
207 };
208 
209 static const struct attribute_group ddr_perf_cpumask_attr_group = {
210 	.attrs = ddr_perf_cpumask_attrs,
211 };
212 
213 static ssize_t
214 ddr_pmu_event_show(struct device *dev, struct device_attribute *attr,
215 		   char *page)
216 {
217 	struct perf_pmu_events_attr *pmu_attr;
218 
219 	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
220 	return sysfs_emit(page, "event=0x%02llx\n", pmu_attr->id);
221 }
222 
223 #define IMX8_DDR_PMU_EVENT_ATTR(_name, _id)		\
224 	PMU_EVENT_ATTR_ID(_name, ddr_pmu_event_show, _id)
225 
226 static struct attribute *ddr_perf_events_attrs[] = {
227 	IMX8_DDR_PMU_EVENT_ATTR(cycles, EVENT_CYCLES_ID),
228 	IMX8_DDR_PMU_EVENT_ATTR(selfresh, 0x01),
229 	IMX8_DDR_PMU_EVENT_ATTR(read-accesses, 0x04),
230 	IMX8_DDR_PMU_EVENT_ATTR(write-accesses, 0x05),
231 	IMX8_DDR_PMU_EVENT_ATTR(read-queue-depth, 0x08),
232 	IMX8_DDR_PMU_EVENT_ATTR(write-queue-depth, 0x09),
233 	IMX8_DDR_PMU_EVENT_ATTR(lp-read-credit-cnt, 0x10),
234 	IMX8_DDR_PMU_EVENT_ATTR(hp-read-credit-cnt, 0x11),
235 	IMX8_DDR_PMU_EVENT_ATTR(write-credit-cnt, 0x12),
236 	IMX8_DDR_PMU_EVENT_ATTR(read-command, 0x20),
237 	IMX8_DDR_PMU_EVENT_ATTR(write-command, 0x21),
238 	IMX8_DDR_PMU_EVENT_ATTR(read-modify-write-command, 0x22),
239 	IMX8_DDR_PMU_EVENT_ATTR(hp-read, 0x23),
240 	IMX8_DDR_PMU_EVENT_ATTR(hp-req-nocredit, 0x24),
241 	IMX8_DDR_PMU_EVENT_ATTR(hp-xact-credit, 0x25),
242 	IMX8_DDR_PMU_EVENT_ATTR(lp-req-nocredit, 0x26),
243 	IMX8_DDR_PMU_EVENT_ATTR(lp-xact-credit, 0x27),
244 	IMX8_DDR_PMU_EVENT_ATTR(wr-xact-credit, 0x29),
245 	IMX8_DDR_PMU_EVENT_ATTR(read-cycles, 0x2a),
246 	IMX8_DDR_PMU_EVENT_ATTR(write-cycles, 0x2b),
247 	IMX8_DDR_PMU_EVENT_ATTR(read-write-transition, 0x30),
248 	IMX8_DDR_PMU_EVENT_ATTR(precharge, 0x31),
249 	IMX8_DDR_PMU_EVENT_ATTR(activate, 0x32),
250 	IMX8_DDR_PMU_EVENT_ATTR(load-mode, 0x33),
251 	IMX8_DDR_PMU_EVENT_ATTR(perf-mwr, 0x34),
252 	IMX8_DDR_PMU_EVENT_ATTR(read, 0x35),
253 	IMX8_DDR_PMU_EVENT_ATTR(read-activate, 0x36),
254 	IMX8_DDR_PMU_EVENT_ATTR(refresh, 0x37),
255 	IMX8_DDR_PMU_EVENT_ATTR(write, 0x38),
256 	IMX8_DDR_PMU_EVENT_ATTR(raw-hazard, 0x39),
257 	IMX8_DDR_PMU_EVENT_ATTR(axid-read, 0x41),
258 	IMX8_DDR_PMU_EVENT_ATTR(axid-write, 0x42),
259 	NULL,
260 };
261 
262 static const struct attribute_group ddr_perf_events_attr_group = {
263 	.name = "events",
264 	.attrs = ddr_perf_events_attrs,
265 };
266 
267 PMU_FORMAT_ATTR(event, "config:0-7");
268 PMU_FORMAT_ATTR(axi_id, "config1:0-15");
269 PMU_FORMAT_ATTR(axi_mask, "config1:16-31");
270 
271 static struct attribute *ddr_perf_format_attrs[] = {
272 	&format_attr_event.attr,
273 	&format_attr_axi_id.attr,
274 	&format_attr_axi_mask.attr,
275 	NULL,
276 };
277 
278 static const struct attribute_group ddr_perf_format_attr_group = {
279 	.name = "format",
280 	.attrs = ddr_perf_format_attrs,
281 };
282 
283 static const struct attribute_group *attr_groups[] = {
284 	&ddr_perf_events_attr_group,
285 	&ddr_perf_format_attr_group,
286 	&ddr_perf_cpumask_attr_group,
287 	&ddr_perf_filter_cap_attr_group,
288 	&ddr_perf_identifier_attr_group,
289 	NULL,
290 };
291 
292 static bool ddr_perf_is_filtered(struct perf_event *event)
293 {
294 	return event->attr.config == 0x41 || event->attr.config == 0x42;
295 }
296 
297 static u32 ddr_perf_filter_val(struct perf_event *event)
298 {
299 	return event->attr.config1;
300 }
301 
302 static bool ddr_perf_filters_compatible(struct perf_event *a,
303 					struct perf_event *b)
304 {
305 	if (!ddr_perf_is_filtered(a))
306 		return true;
307 	if (!ddr_perf_is_filtered(b))
308 		return true;
309 	return ddr_perf_filter_val(a) == ddr_perf_filter_val(b);
310 }
311 
312 static bool ddr_perf_is_enhanced_filtered(struct perf_event *event)
313 {
314 	unsigned int filt;
315 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
316 
317 	filt = pmu->devtype_data->quirks & DDR_CAP_AXI_ID_FILTER_ENHANCED;
318 	return (filt == DDR_CAP_AXI_ID_FILTER_ENHANCED) &&
319 		ddr_perf_is_filtered(event);
320 }
321 
322 static u32 ddr_perf_alloc_counter(struct ddr_pmu *pmu, int event)
323 {
324 	int i;
325 
326 	/*
327 	 * Always map cycle event to counter 0
328 	 * Cycles counter is dedicated for cycle event
329 	 * can't used for the other events
330 	 */
331 	if (event == EVENT_CYCLES_ID) {
332 		if (pmu->events[EVENT_CYCLES_COUNTER] == NULL)
333 			return EVENT_CYCLES_COUNTER;
334 		else
335 			return -ENOENT;
336 	}
337 
338 	for (i = 1; i < NUM_COUNTERS; i++) {
339 		if (pmu->events[i] == NULL)
340 			return i;
341 	}
342 
343 	return -ENOENT;
344 }
345 
346 static void ddr_perf_free_counter(struct ddr_pmu *pmu, int counter)
347 {
348 	pmu->events[counter] = NULL;
349 }
350 
351 static u32 ddr_perf_read_counter(struct ddr_pmu *pmu, int counter)
352 {
353 	struct perf_event *event = pmu->events[counter];
354 	void __iomem *base = pmu->base;
355 
356 	/*
357 	 * return bytes instead of bursts from ddr transaction for
358 	 * axid-read and axid-write event if PMU core supports enhanced
359 	 * filter.
360 	 */
361 	base += ddr_perf_is_enhanced_filtered(event) ? COUNTER_DPCR1 :
362 						       COUNTER_READ;
363 	return readl_relaxed(base + counter * 4);
364 }
365 
366 static int ddr_perf_event_init(struct perf_event *event)
367 {
368 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
369 	struct hw_perf_event *hwc = &event->hw;
370 	struct perf_event *sibling;
371 
372 	if (event->attr.type != event->pmu->type)
373 		return -ENOENT;
374 
375 	if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
376 		return -EOPNOTSUPP;
377 
378 	if (event->cpu < 0) {
379 		dev_warn(pmu->dev, "Can't provide per-task data!\n");
380 		return -EOPNOTSUPP;
381 	}
382 
383 	/*
384 	 * We must NOT create groups containing mixed PMUs, although software
385 	 * events are acceptable (for example to create a CCN group
386 	 * periodically read when a hrtimer aka cpu-clock leader triggers).
387 	 */
388 	if (event->group_leader->pmu != event->pmu &&
389 			!is_software_event(event->group_leader))
390 		return -EINVAL;
391 
392 	if (pmu->devtype_data->quirks & DDR_CAP_AXI_ID_FILTER) {
393 		if (!ddr_perf_filters_compatible(event, event->group_leader))
394 			return -EINVAL;
395 		for_each_sibling_event(sibling, event->group_leader) {
396 			if (!ddr_perf_filters_compatible(event, sibling))
397 				return -EINVAL;
398 		}
399 	}
400 
401 	for_each_sibling_event(sibling, event->group_leader) {
402 		if (sibling->pmu != event->pmu &&
403 				!is_software_event(sibling))
404 			return -EINVAL;
405 	}
406 
407 	event->cpu = pmu->cpu;
408 	hwc->idx = -1;
409 
410 	return 0;
411 }
412 
413 static void ddr_perf_counter_enable(struct ddr_pmu *pmu, int config,
414 				  int counter, bool enable)
415 {
416 	u8 reg = counter * 4 + COUNTER_CNTL;
417 	int val;
418 
419 	if (enable) {
420 		/*
421 		 * cycle counter is special which should firstly write 0 then
422 		 * write 1 into CLEAR bit to clear it. Other counters only
423 		 * need write 0 into CLEAR bit and it turns out to be 1 by
424 		 * hardware. Below enable flow is harmless for all counters.
425 		 */
426 		writel(0, pmu->base + reg);
427 		val = CNTL_EN | CNTL_CLEAR;
428 		val |= FIELD_PREP(CNTL_CSV_MASK, config);
429 		writel(val, pmu->base + reg);
430 	} else {
431 		/* Disable counter */
432 		val = readl_relaxed(pmu->base + reg) & CNTL_EN_MASK;
433 		writel(val, pmu->base + reg);
434 	}
435 }
436 
437 static bool ddr_perf_counter_overflow(struct ddr_pmu *pmu, int counter)
438 {
439 	int val;
440 
441 	val = readl_relaxed(pmu->base + counter * 4 + COUNTER_CNTL);
442 
443 	return val & CNTL_OVER;
444 }
445 
446 static void ddr_perf_counter_clear(struct ddr_pmu *pmu, int counter)
447 {
448 	u8 reg = counter * 4 + COUNTER_CNTL;
449 	int val;
450 
451 	val = readl_relaxed(pmu->base + reg);
452 	val &= ~CNTL_CLEAR;
453 	writel(val, pmu->base + reg);
454 
455 	val |= CNTL_CLEAR;
456 	writel(val, pmu->base + reg);
457 }
458 
459 static void ddr_perf_event_update(struct perf_event *event)
460 {
461 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
462 	struct hw_perf_event *hwc = &event->hw;
463 	u64 new_raw_count;
464 	int counter = hwc->idx;
465 	int ret;
466 
467 	new_raw_count = ddr_perf_read_counter(pmu, counter);
468 	local64_add(new_raw_count, &event->count);
469 
470 	/*
471 	 * For legacy SoCs: event counter continue counting when overflow,
472 	 *                  no need to clear the counter.
473 	 * For new SoCs: event counter stop counting when overflow, need
474 	 *               clear counter to let it count again.
475 	 */
476 	if (counter != EVENT_CYCLES_COUNTER) {
477 		ret = ddr_perf_counter_overflow(pmu, counter);
478 		if (ret)
479 			dev_warn_ratelimited(pmu->dev,  "events lost due to counter overflow (config 0x%llx)\n",
480 					     event->attr.config);
481 	}
482 
483 	/* clear counter every time for both cycle counter and event counter */
484 	ddr_perf_counter_clear(pmu, counter);
485 }
486 
487 static void ddr_perf_event_start(struct perf_event *event, int flags)
488 {
489 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
490 	struct hw_perf_event *hwc = &event->hw;
491 	int counter = hwc->idx;
492 
493 	local64_set(&hwc->prev_count, 0);
494 
495 	ddr_perf_counter_enable(pmu, event->attr.config, counter, true);
496 
497 	hwc->state = 0;
498 }
499 
500 static int ddr_perf_event_add(struct perf_event *event, int flags)
501 {
502 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
503 	struct hw_perf_event *hwc = &event->hw;
504 	int counter;
505 	int cfg = event->attr.config;
506 	int cfg1 = event->attr.config1;
507 
508 	if (pmu->devtype_data->quirks & DDR_CAP_AXI_ID_FILTER) {
509 		int i;
510 
511 		for (i = 1; i < NUM_COUNTERS; i++) {
512 			if (pmu->events[i] &&
513 			    !ddr_perf_filters_compatible(event, pmu->events[i]))
514 				return -EINVAL;
515 		}
516 
517 		if (ddr_perf_is_filtered(event)) {
518 			/* revert axi id masking(axi_mask) value */
519 			cfg1 ^= AXI_MASKING_REVERT;
520 			writel(cfg1, pmu->base + COUNTER_DPCR1);
521 		}
522 	}
523 
524 	counter = ddr_perf_alloc_counter(pmu, cfg);
525 	if (counter < 0) {
526 		dev_dbg(pmu->dev, "There are not enough counters\n");
527 		return -EOPNOTSUPP;
528 	}
529 
530 	pmu->events[counter] = event;
531 	hwc->idx = counter;
532 
533 	hwc->state |= PERF_HES_STOPPED;
534 
535 	if (flags & PERF_EF_START)
536 		ddr_perf_event_start(event, flags);
537 
538 	return 0;
539 }
540 
541 static void ddr_perf_event_stop(struct perf_event *event, int flags)
542 {
543 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
544 	struct hw_perf_event *hwc = &event->hw;
545 	int counter = hwc->idx;
546 
547 	ddr_perf_counter_enable(pmu, event->attr.config, counter, false);
548 	ddr_perf_event_update(event);
549 
550 	hwc->state |= PERF_HES_STOPPED;
551 }
552 
553 static void ddr_perf_event_del(struct perf_event *event, int flags)
554 {
555 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
556 	struct hw_perf_event *hwc = &event->hw;
557 	int counter = hwc->idx;
558 
559 	ddr_perf_event_stop(event, PERF_EF_UPDATE);
560 
561 	ddr_perf_free_counter(pmu, counter);
562 	hwc->idx = -1;
563 }
564 
565 static void ddr_perf_pmu_enable(struct pmu *pmu)
566 {
567 	struct ddr_pmu *ddr_pmu = to_ddr_pmu(pmu);
568 
569 	/* enable cycle counter if cycle is not active event list */
570 	if (ddr_pmu->events[EVENT_CYCLES_COUNTER] == NULL)
571 		ddr_perf_counter_enable(ddr_pmu,
572 				      EVENT_CYCLES_ID,
573 				      EVENT_CYCLES_COUNTER,
574 				      true);
575 }
576 
577 static void ddr_perf_pmu_disable(struct pmu *pmu)
578 {
579 	struct ddr_pmu *ddr_pmu = to_ddr_pmu(pmu);
580 
581 	if (ddr_pmu->events[EVENT_CYCLES_COUNTER] == NULL)
582 		ddr_perf_counter_enable(ddr_pmu,
583 				      EVENT_CYCLES_ID,
584 				      EVENT_CYCLES_COUNTER,
585 				      false);
586 }
587 
588 static int ddr_perf_init(struct ddr_pmu *pmu, void __iomem *base,
589 			 struct device *dev)
590 {
591 	*pmu = (struct ddr_pmu) {
592 		.pmu = (struct pmu) {
593 			.module	      = THIS_MODULE,
594 			.capabilities = PERF_PMU_CAP_NO_EXCLUDE,
595 			.task_ctx_nr = perf_invalid_context,
596 			.attr_groups = attr_groups,
597 			.event_init  = ddr_perf_event_init,
598 			.add	     = ddr_perf_event_add,
599 			.del	     = ddr_perf_event_del,
600 			.start	     = ddr_perf_event_start,
601 			.stop	     = ddr_perf_event_stop,
602 			.read	     = ddr_perf_event_update,
603 			.pmu_enable  = ddr_perf_pmu_enable,
604 			.pmu_disable = ddr_perf_pmu_disable,
605 		},
606 		.base = base,
607 		.dev = dev,
608 	};
609 
610 	pmu->id = ida_alloc(&ddr_ida, GFP_KERNEL);
611 	return pmu->id;
612 }
613 
614 static irqreturn_t ddr_perf_irq_handler(int irq, void *p)
615 {
616 	int i;
617 	struct ddr_pmu *pmu = (struct ddr_pmu *) p;
618 	struct perf_event *event;
619 
620 	/* all counter will stop if cycle counter disabled */
621 	ddr_perf_counter_enable(pmu,
622 			      EVENT_CYCLES_ID,
623 			      EVENT_CYCLES_COUNTER,
624 			      false);
625 	/*
626 	 * When the cycle counter overflows, all counters are stopped,
627 	 * and an IRQ is raised. If any other counter overflows, it
628 	 * continues counting, and no IRQ is raised. But for new SoCs,
629 	 * such as i.MX8MP, event counter would stop when overflow, so
630 	 * we need use cycle counter to stop overflow of event counter.
631 	 *
632 	 * Cycles occur at least 4 times as often as other events, so we
633 	 * can update all events on a cycle counter overflow and not
634 	 * lose events.
635 	 *
636 	 */
637 	for (i = 0; i < NUM_COUNTERS; i++) {
638 
639 		if (!pmu->events[i])
640 			continue;
641 
642 		event = pmu->events[i];
643 
644 		ddr_perf_event_update(event);
645 	}
646 
647 	ddr_perf_counter_enable(pmu,
648 			      EVENT_CYCLES_ID,
649 			      EVENT_CYCLES_COUNTER,
650 			      true);
651 
652 	return IRQ_HANDLED;
653 }
654 
655 static int ddr_perf_offline_cpu(unsigned int cpu, struct hlist_node *node)
656 {
657 	struct ddr_pmu *pmu = hlist_entry_safe(node, struct ddr_pmu, node);
658 	int target;
659 
660 	if (cpu != pmu->cpu)
661 		return 0;
662 
663 	target = cpumask_any_but(cpu_online_mask, cpu);
664 	if (target >= nr_cpu_ids)
665 		return 0;
666 
667 	perf_pmu_migrate_context(&pmu->pmu, cpu, target);
668 	pmu->cpu = target;
669 
670 	WARN_ON(irq_set_affinity(pmu->irq, cpumask_of(pmu->cpu)));
671 
672 	return 0;
673 }
674 
675 static int ddr_perf_probe(struct platform_device *pdev)
676 {
677 	struct ddr_pmu *pmu;
678 	struct device_node *np;
679 	void __iomem *base;
680 	char *name;
681 	int num;
682 	int ret;
683 	int irq;
684 
685 	base = devm_platform_ioremap_resource(pdev, 0);
686 	if (IS_ERR(base))
687 		return PTR_ERR(base);
688 
689 	np = pdev->dev.of_node;
690 
691 	pmu = devm_kzalloc(&pdev->dev, sizeof(*pmu), GFP_KERNEL);
692 	if (!pmu)
693 		return -ENOMEM;
694 
695 	num = ddr_perf_init(pmu, base, &pdev->dev);
696 
697 	platform_set_drvdata(pdev, pmu);
698 
699 	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, DDR_PERF_DEV_NAME "%d",
700 			      num);
701 	if (!name) {
702 		ret = -ENOMEM;
703 		goto cpuhp_state_err;
704 	}
705 
706 	pmu->devtype_data = of_device_get_match_data(&pdev->dev);
707 
708 	pmu->cpu = raw_smp_processor_id();
709 	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
710 				      DDR_CPUHP_CB_NAME,
711 				      NULL,
712 				      ddr_perf_offline_cpu);
713 
714 	if (ret < 0) {
715 		dev_err(&pdev->dev, "cpuhp_setup_state_multi failed\n");
716 		goto cpuhp_state_err;
717 	}
718 
719 	pmu->cpuhp_state = ret;
720 
721 	/* Register the pmu instance for cpu hotplug */
722 	ret = cpuhp_state_add_instance_nocalls(pmu->cpuhp_state, &pmu->node);
723 	if (ret) {
724 		dev_err(&pdev->dev, "Error %d registering hotplug\n", ret);
725 		goto cpuhp_instance_err;
726 	}
727 
728 	/* Request irq */
729 	irq = of_irq_get(np, 0);
730 	if (irq < 0) {
731 		dev_err(&pdev->dev, "Failed to get irq: %d", irq);
732 		ret = irq;
733 		goto ddr_perf_err;
734 	}
735 
736 	ret = devm_request_irq(&pdev->dev, irq,
737 					ddr_perf_irq_handler,
738 					IRQF_NOBALANCING | IRQF_NO_THREAD,
739 					DDR_CPUHP_CB_NAME,
740 					pmu);
741 	if (ret < 0) {
742 		dev_err(&pdev->dev, "Request irq failed: %d", ret);
743 		goto ddr_perf_err;
744 	}
745 
746 	pmu->irq = irq;
747 	ret = irq_set_affinity(pmu->irq, cpumask_of(pmu->cpu));
748 	if (ret) {
749 		dev_err(pmu->dev, "Failed to set interrupt affinity!\n");
750 		goto ddr_perf_err;
751 	}
752 
753 	ret = perf_pmu_register(&pmu->pmu, name, -1);
754 	if (ret)
755 		goto ddr_perf_err;
756 
757 	return 0;
758 
759 ddr_perf_err:
760 	cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
761 cpuhp_instance_err:
762 	cpuhp_remove_multi_state(pmu->cpuhp_state);
763 cpuhp_state_err:
764 	ida_free(&ddr_ida, pmu->id);
765 	dev_warn(&pdev->dev, "i.MX8 DDR Perf PMU failed (%d), disabled\n", ret);
766 	return ret;
767 }
768 
769 static int ddr_perf_remove(struct platform_device *pdev)
770 {
771 	struct ddr_pmu *pmu = platform_get_drvdata(pdev);
772 
773 	cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
774 	cpuhp_remove_multi_state(pmu->cpuhp_state);
775 
776 	perf_pmu_unregister(&pmu->pmu);
777 
778 	ida_free(&ddr_ida, pmu->id);
779 	return 0;
780 }
781 
782 static struct platform_driver imx_ddr_pmu_driver = {
783 	.driver         = {
784 		.name   = "imx-ddr-pmu",
785 		.of_match_table = imx_ddr_pmu_dt_ids,
786 		.suppress_bind_attrs = true,
787 	},
788 	.probe          = ddr_perf_probe,
789 	.remove         = ddr_perf_remove,
790 };
791 
792 module_platform_driver(imx_ddr_pmu_driver);
793 MODULE_LICENSE("GPL v2");
794