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