1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright 2023 NXP
3 
4 #include <linux/bitfield.h>
5 #include <linux/init.h>
6 #include <linux/interrupt.h>
7 #include <linux/io.h>
8 #include <linux/module.h>
9 #include <linux/of.h>
10 #include <linux/platform_device.h>
11 #include <linux/perf_event.h>
12 
13 /* Performance monitor configuration */
14 #define PMCFG1  			0x00
15 #define PMCFG1_RD_TRANS_FILT_EN 	BIT(31)
16 #define PMCFG1_WR_TRANS_FILT_EN 	BIT(30)
17 #define PMCFG1_RD_BT_FILT_EN 		BIT(29)
18 #define PMCFG1_ID_MASK  		GENMASK(17, 0)
19 
20 #define PMCFG2  			0x04
21 #define PMCFG2_ID			GENMASK(17, 0)
22 
23 /* Global control register affects all counters and takes priority over local control registers */
24 #define PMGC0		0x40
25 /* Global control register bits */
26 #define PMGC0_FAC	BIT(31)
27 #define PMGC0_PMIE	BIT(30)
28 #define PMGC0_FCECE	BIT(29)
29 
30 /*
31  * 64bit counter0 exclusively dedicated to counting cycles
32  * 32bit counters monitor counter-specific events in addition to counting reference events
33  */
34 #define PMLCA(n)	(0x40 + 0x10 + (0x10 * n))
35 #define PMLCB(n)	(0x40 + 0x14 + (0x10 * n))
36 #define PMC(n)		(0x40 + 0x18 + (0x10 * n))
37 /* Local control register bits */
38 #define PMLCA_FC	BIT(31)
39 #define PMLCA_CE	BIT(26)
40 #define PMLCA_EVENT	GENMASK(22, 16)
41 
42 #define NUM_COUNTERS		11
43 #define CYCLES_COUNTER		0
44 
45 #define to_ddr_pmu(p)		container_of(p, struct ddr_pmu, pmu)
46 
47 #define DDR_PERF_DEV_NAME	"imx9_ddr"
48 #define DDR_CPUHP_CB_NAME	DDR_PERF_DEV_NAME "_perf_pmu"
49 
50 static DEFINE_IDA(ddr_ida);
51 
52 struct imx_ddr_devtype_data {
53 	const char *identifier;		/* system PMU identifier for userspace */
54 };
55 
56 struct ddr_pmu {
57 	struct pmu pmu;
58 	void __iomem *base;
59 	unsigned int cpu;
60 	struct hlist_node node;
61 	struct device *dev;
62 	struct perf_event *events[NUM_COUNTERS];
63 	int active_events;
64 	enum cpuhp_state cpuhp_state;
65 	const struct imx_ddr_devtype_data *devtype_data;
66 	int irq;
67 	int id;
68 };
69 
70 static const struct imx_ddr_devtype_data imx93_devtype_data = {
71 	.identifier = "imx93",
72 };
73 
74 static const struct of_device_id imx_ddr_pmu_dt_ids[] = {
75 	{.compatible = "fsl,imx93-ddr-pmu", .data = &imx93_devtype_data},
76 	{ /* sentinel */ }
77 };
78 MODULE_DEVICE_TABLE(of, imx_ddr_pmu_dt_ids);
79 
80 static ssize_t ddr_perf_identifier_show(struct device *dev,
81 					struct device_attribute *attr,
82 					char *page)
83 {
84 	struct ddr_pmu *pmu = dev_get_drvdata(dev);
85 
86 	return sysfs_emit(page, "%s\n", pmu->devtype_data->identifier);
87 }
88 
89 static struct device_attribute ddr_perf_identifier_attr =
90 	__ATTR(identifier, 0444, ddr_perf_identifier_show, NULL);
91 
92 static struct attribute *ddr_perf_identifier_attrs[] = {
93 	&ddr_perf_identifier_attr.attr,
94 	NULL,
95 };
96 
97 static struct attribute_group ddr_perf_identifier_attr_group = {
98 	.attrs = ddr_perf_identifier_attrs,
99 };
100 
101 static ssize_t ddr_perf_cpumask_show(struct device *dev,
102 				     struct device_attribute *attr, char *buf)
103 {
104 	struct ddr_pmu *pmu = dev_get_drvdata(dev);
105 
106 	return cpumap_print_to_pagebuf(true, buf, cpumask_of(pmu->cpu));
107 }
108 
109 static struct device_attribute ddr_perf_cpumask_attr =
110 	__ATTR(cpumask, 0444, ddr_perf_cpumask_show, NULL);
111 
112 static struct attribute *ddr_perf_cpumask_attrs[] = {
113 	&ddr_perf_cpumask_attr.attr,
114 	NULL,
115 };
116 
117 static const struct attribute_group ddr_perf_cpumask_attr_group = {
118 	.attrs = ddr_perf_cpumask_attrs,
119 };
120 
121 static ssize_t ddr_pmu_event_show(struct device *dev,
122 				  struct device_attribute *attr, char *page)
123 {
124 	struct perf_pmu_events_attr *pmu_attr;
125 
126 	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
127 	return sysfs_emit(page, "event=0x%02llx\n", pmu_attr->id);
128 }
129 
130 #define IMX9_DDR_PMU_EVENT_ATTR(_name, _id)				\
131 	(&((struct perf_pmu_events_attr[]) {				\
132 		{ .attr = __ATTR(_name, 0444, ddr_pmu_event_show, NULL),\
133 		  .id = _id, }						\
134 	})[0].attr.attr)
135 
136 static struct attribute *ddr_perf_events_attrs[] = {
137 	/* counter0 cycles event */
138 	IMX9_DDR_PMU_EVENT_ATTR(cycles, 0),
139 
140 	/* reference events for all normal counters, need assert DEBUG19[21] bit */
141 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ddrc1_rmw_for_ecc, 12),
142 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pmon_rreorder, 13),
143 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pmon_wreorder, 14),
144 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_0, 15),
145 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_1, 16),
146 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_2, 17),
147 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_3, 18),
148 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_4, 19),
149 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_5, 22),
150 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_6, 23),
151 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_7, 24),
152 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_8, 25),
153 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_9, 26),
154 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_10, 27),
155 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_11, 28),
156 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_12, 31),
157 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_13, 59),
158 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_15, 61),
159 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_pm_29, 63),
160 
161 	/* counter1 specific events */
162 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_riq_0, 64),
163 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_riq_1, 65),
164 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_riq_2, 66),
165 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_riq_3, 67),
166 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_riq_4, 68),
167 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_riq_5, 69),
168 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_riq_6, 70),
169 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_riq_7, 71),
170 
171 	/* counter2 specific events */
172 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_wiq_0, 64),
173 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_wiq_1, 65),
174 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_wiq_2, 66),
175 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_wiq_3, 67),
176 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_wiq_4, 68),
177 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_wiq_5, 69),
178 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_wiq_6, 70),
179 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_ld_wiq_7, 71),
180 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pmon_empty, 72),
181 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pm_rd_trans_filt, 73),
182 
183 	/* counter3 specific events */
184 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_collision_0, 64),
185 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_collision_1, 65),
186 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_collision_2, 66),
187 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_collision_3, 67),
188 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_collision_4, 68),
189 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_collision_5, 69),
190 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_collision_6, 70),
191 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_collision_7, 71),
192 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pmon_full, 72),
193 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pm_wr_trans_filt, 73),
194 
195 	/* counter4 specific events */
196 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_open_0, 64),
197 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_open_1, 65),
198 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_open_2, 66),
199 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_open_3, 67),
200 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_open_4, 68),
201 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_open_5, 69),
202 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_open_6, 70),
203 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_row_open_7, 71),
204 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pmon_ld_rdq2_rmw, 72),
205 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pm_rd_beat_filt, 73),
206 
207 	/* counter5 specific events */
208 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_valid_start_0, 64),
209 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_valid_start_1, 65),
210 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_valid_start_2, 66),
211 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_valid_start_3, 67),
212 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_valid_start_4, 68),
213 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_valid_start_5, 69),
214 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_valid_start_6, 70),
215 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_valid_start_7, 71),
216 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pmon_ld_rdq1, 72),
217 
218 	/* counter6 specific events */
219 	IMX9_DDR_PMU_EVENT_ATTR(ddrc_qx_valid_end_0, 64),
220 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pmon_ld_rdq2, 72),
221 
222 	/* counter7 specific events */
223 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pmon_1_2_full, 64),
224 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pmon_ld_wrq0, 65),
225 
226 	/* counter8 specific events */
227 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pmon_bias_switched, 64),
228 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pmon_1_4_full, 65),
229 
230 	/* counter9 specific events */
231 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pmon_ld_wrq1, 65),
232 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pmon_3_4_full, 66),
233 
234 	/* counter10 specific events */
235 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pmon_misc_mrk, 65),
236 	IMX9_DDR_PMU_EVENT_ATTR(eddrtq_pmon_ld_rdq0, 66),
237 	NULL,
238 };
239 
240 static const struct attribute_group ddr_perf_events_attr_group = {
241 	.name = "events",
242 	.attrs = ddr_perf_events_attrs,
243 };
244 
245 PMU_FORMAT_ATTR(event, "config:0-7");
246 PMU_FORMAT_ATTR(counter, "config:8-15");
247 PMU_FORMAT_ATTR(axi_id, "config1:0-17");
248 PMU_FORMAT_ATTR(axi_mask, "config2:0-17");
249 
250 static struct attribute *ddr_perf_format_attrs[] = {
251 	&format_attr_event.attr,
252 	&format_attr_counter.attr,
253 	&format_attr_axi_id.attr,
254 	&format_attr_axi_mask.attr,
255 	NULL,
256 };
257 
258 static const struct attribute_group ddr_perf_format_attr_group = {
259 	.name = "format",
260 	.attrs = ddr_perf_format_attrs,
261 };
262 
263 static const struct attribute_group *attr_groups[] = {
264 	&ddr_perf_identifier_attr_group,
265 	&ddr_perf_cpumask_attr_group,
266 	&ddr_perf_events_attr_group,
267 	&ddr_perf_format_attr_group,
268 	NULL,
269 };
270 
271 static void ddr_perf_clear_counter(struct ddr_pmu *pmu, int counter)
272 {
273 	if (counter == CYCLES_COUNTER) {
274 		writel(0, pmu->base + PMC(counter) + 0x4);
275 		writel(0, pmu->base + PMC(counter));
276 	} else {
277 		writel(0, pmu->base + PMC(counter));
278 	}
279 }
280 
281 static u64 ddr_perf_read_counter(struct ddr_pmu *pmu, int counter)
282 {
283 	u32 val_lower, val_upper;
284 	u64 val;
285 
286 	if (counter != CYCLES_COUNTER) {
287 		val = readl_relaxed(pmu->base + PMC(counter));
288 		goto out;
289 	}
290 
291 	/* special handling for reading 64bit cycle counter */
292 	do {
293 		val_upper = readl_relaxed(pmu->base + PMC(counter) + 0x4);
294 		val_lower = readl_relaxed(pmu->base + PMC(counter));
295 	} while (val_upper != readl_relaxed(pmu->base + PMC(counter) + 0x4));
296 
297 	val = val_upper;
298 	val = (val << 32);
299 	val |= val_lower;
300 out:
301 	return val;
302 }
303 
304 static void ddr_perf_counter_global_config(struct ddr_pmu *pmu, bool enable)
305 {
306 	u32 ctrl;
307 
308 	ctrl = readl_relaxed(pmu->base + PMGC0);
309 
310 	if (enable) {
311 		/*
312 		 * The performance monitor must be reset before event counting
313 		 * sequences. The performance monitor can be reset by first freezing
314 		 * one or more counters and then clearing the freeze condition to
315 		 * allow the counters to count according to the settings in the
316 		 * performance monitor registers. Counters can be frozen individually
317 		 * by setting PMLCAn[FC] bits, or simultaneously by setting PMGC0[FAC].
318 		 * Simply clearing these freeze bits will then allow the performance
319 		 * monitor to begin counting based on the register settings.
320 		 */
321 		ctrl |= PMGC0_FAC;
322 		writel(ctrl, pmu->base + PMGC0);
323 
324 		/*
325 		 * Freeze all counters disabled, interrupt enabled, and freeze
326 		 * counters on condition enabled.
327 		 */
328 		ctrl &= ~PMGC0_FAC;
329 		ctrl |= PMGC0_PMIE | PMGC0_FCECE;
330 		writel(ctrl, pmu->base + PMGC0);
331 	} else {
332 		ctrl |= PMGC0_FAC;
333 		ctrl &= ~(PMGC0_PMIE | PMGC0_FCECE);
334 		writel(ctrl, pmu->base + PMGC0);
335 	}
336 }
337 
338 static void ddr_perf_counter_local_config(struct ddr_pmu *pmu, int config,
339 				    int counter, bool enable)
340 {
341 	u32 ctrl_a;
342 
343 	ctrl_a = readl_relaxed(pmu->base + PMLCA(counter));
344 
345 	if (enable) {
346 		ctrl_a |= PMLCA_FC;
347 		writel(ctrl_a, pmu->base + PMLCA(counter));
348 
349 		ddr_perf_clear_counter(pmu, counter);
350 
351 		/* Freeze counter disabled, condition enabled, and program event.*/
352 		ctrl_a &= ~PMLCA_FC;
353 		ctrl_a |= PMLCA_CE;
354 		ctrl_a &= ~FIELD_PREP(PMLCA_EVENT, 0x7F);
355 		ctrl_a |= FIELD_PREP(PMLCA_EVENT, (config & 0x000000FF));
356 		writel(ctrl_a, pmu->base + PMLCA(counter));
357 	} else {
358 		/* Freeze counter. */
359 		ctrl_a |= PMLCA_FC;
360 		writel(ctrl_a, pmu->base + PMLCA(counter));
361 	}
362 }
363 
364 static void ddr_perf_monitor_config(struct ddr_pmu *pmu, int cfg, int cfg1, int cfg2)
365 {
366 	u32 pmcfg1, pmcfg2;
367 	int event, counter;
368 
369 	event = cfg & 0x000000FF;
370 	counter = (cfg & 0x0000FF00) >> 8;
371 
372 	pmcfg1 = readl_relaxed(pmu->base + PMCFG1);
373 
374 	if (counter == 2 && event == 73)
375 		pmcfg1 |= PMCFG1_RD_TRANS_FILT_EN;
376 	else if (counter == 2 && event != 73)
377 		pmcfg1 &= ~PMCFG1_RD_TRANS_FILT_EN;
378 
379 	if (counter == 3 && event == 73)
380 		pmcfg1 |= PMCFG1_WR_TRANS_FILT_EN;
381 	else if (counter == 3 && event != 73)
382 		pmcfg1 &= ~PMCFG1_WR_TRANS_FILT_EN;
383 
384 	if (counter == 4 && event == 73)
385 		pmcfg1 |= PMCFG1_RD_BT_FILT_EN;
386 	else if (counter == 4 && event != 73)
387 		pmcfg1 &= ~PMCFG1_RD_BT_FILT_EN;
388 
389 	pmcfg1 &= ~FIELD_PREP(PMCFG1_ID_MASK, 0x3FFFF);
390 	pmcfg1 |= FIELD_PREP(PMCFG1_ID_MASK, cfg2);
391 	writel(pmcfg1, pmu->base + PMCFG1);
392 
393 	pmcfg2 = readl_relaxed(pmu->base + PMCFG2);
394 	pmcfg2 &= ~FIELD_PREP(PMCFG2_ID, 0x3FFFF);
395 	pmcfg2 |= FIELD_PREP(PMCFG2_ID, cfg1);
396 	writel(pmcfg2, pmu->base + PMCFG2);
397 }
398 
399 static void ddr_perf_event_update(struct perf_event *event)
400 {
401 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
402 	struct hw_perf_event *hwc = &event->hw;
403 	int counter = hwc->idx;
404 	u64 new_raw_count;
405 
406 	new_raw_count = ddr_perf_read_counter(pmu, counter);
407 	local64_add(new_raw_count, &event->count);
408 
409 	/* clear counter's value every time */
410 	ddr_perf_clear_counter(pmu, counter);
411 }
412 
413 static int ddr_perf_event_init(struct perf_event *event)
414 {
415 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
416 	struct hw_perf_event *hwc = &event->hw;
417 	struct perf_event *sibling;
418 
419 	if (event->attr.type != event->pmu->type)
420 		return -ENOENT;
421 
422 	if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
423 		return -EOPNOTSUPP;
424 
425 	if (event->cpu < 0) {
426 		dev_warn(pmu->dev, "Can't provide per-task data!\n");
427 		return -EOPNOTSUPP;
428 	}
429 
430 	/*
431 	 * We must NOT create groups containing mixed PMUs, although software
432 	 * events are acceptable (for example to create a CCN group
433 	 * periodically read when a hrtimer aka cpu-clock leader triggers).
434 	 */
435 	if (event->group_leader->pmu != event->pmu &&
436 			!is_software_event(event->group_leader))
437 		return -EINVAL;
438 
439 	for_each_sibling_event(sibling, event->group_leader) {
440 		if (sibling->pmu != event->pmu &&
441 				!is_software_event(sibling))
442 			return -EINVAL;
443 	}
444 
445 	event->cpu = pmu->cpu;
446 	hwc->idx = -1;
447 
448 	return 0;
449 }
450 
451 static void ddr_perf_event_start(struct perf_event *event, int flags)
452 {
453 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
454 	struct hw_perf_event *hwc = &event->hw;
455 	int counter = hwc->idx;
456 
457 	local64_set(&hwc->prev_count, 0);
458 
459 	ddr_perf_counter_local_config(pmu, event->attr.config, counter, true);
460 	hwc->state = 0;
461 }
462 
463 static int ddr_perf_event_add(struct perf_event *event, int flags)
464 {
465 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
466 	struct hw_perf_event *hwc = &event->hw;
467 	int cfg = event->attr.config;
468 	int cfg1 = event->attr.config1;
469 	int cfg2 = event->attr.config2;
470 	int counter;
471 
472 	counter = (cfg & 0x0000FF00) >> 8;
473 
474 	pmu->events[counter] = event;
475 	pmu->active_events++;
476 	hwc->idx = counter;
477 	hwc->state |= PERF_HES_STOPPED;
478 
479 	/* read trans, write trans, read beat */
480 	ddr_perf_monitor_config(pmu, cfg, cfg1, cfg2);
481 
482 	if (flags & PERF_EF_START)
483 		ddr_perf_event_start(event, flags);
484 
485 	return 0;
486 }
487 
488 static void ddr_perf_event_stop(struct perf_event *event, int flags)
489 {
490 	struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
491 	struct hw_perf_event *hwc = &event->hw;
492 	int counter = hwc->idx;
493 
494 	ddr_perf_counter_local_config(pmu, event->attr.config, counter, false);
495 	ddr_perf_event_update(event);
496 
497 	hwc->state |= PERF_HES_STOPPED;
498 }
499 
500 static void ddr_perf_event_del(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 
505 	ddr_perf_event_stop(event, PERF_EF_UPDATE);
506 
507 	pmu->active_events--;
508 	hwc->idx = -1;
509 }
510 
511 static void ddr_perf_pmu_enable(struct pmu *pmu)
512 {
513 	struct ddr_pmu *ddr_pmu = to_ddr_pmu(pmu);
514 
515 	ddr_perf_counter_global_config(ddr_pmu, true);
516 }
517 
518 static void ddr_perf_pmu_disable(struct pmu *pmu)
519 {
520 	struct ddr_pmu *ddr_pmu = to_ddr_pmu(pmu);
521 
522 	ddr_perf_counter_global_config(ddr_pmu, false);
523 }
524 
525 static void ddr_perf_init(struct ddr_pmu *pmu, void __iomem *base,
526 			 struct device *dev)
527 {
528 	*pmu = (struct ddr_pmu) {
529 		.pmu = (struct pmu) {
530 			.module       = THIS_MODULE,
531 			.capabilities = PERF_PMU_CAP_NO_EXCLUDE,
532 			.task_ctx_nr  = perf_invalid_context,
533 			.attr_groups  = attr_groups,
534 			.event_init   = ddr_perf_event_init,
535 			.add          = ddr_perf_event_add,
536 			.del          = ddr_perf_event_del,
537 			.start        = ddr_perf_event_start,
538 			.stop         = ddr_perf_event_stop,
539 			.read         = ddr_perf_event_update,
540 			.pmu_enable   = ddr_perf_pmu_enable,
541 			.pmu_disable  = ddr_perf_pmu_disable,
542 		},
543 		.base = base,
544 		.dev = dev,
545 	};
546 }
547 
548 static irqreturn_t ddr_perf_irq_handler(int irq, void *p)
549 {
550 	struct ddr_pmu *pmu = (struct ddr_pmu *)p;
551 	struct perf_event *event;
552 	int i;
553 
554 	/*
555 	 * Counters can generate an interrupt on an overflow when msb of a
556 	 * counter changes from 0 to 1. For the interrupt to be signalled,
557 	 * below condition mush be satisfied:
558 	 * PMGC0[PMIE] = 1, PMGC0[FCECE] = 1, PMLCAn[CE] = 1
559 	 * When an interrupt is signalled, PMGC0[FAC] is set by hardware and
560 	 * all of the registers are frozen.
561 	 * Software can clear the interrupt condition by resetting the performance
562 	 * monitor and clearing the most significant bit of the counter that
563 	 * generate the overflow.
564 	 */
565 	for (i = 0; i < NUM_COUNTERS; i++) {
566 		if (!pmu->events[i])
567 			continue;
568 
569 		event = pmu->events[i];
570 
571 		ddr_perf_event_update(event);
572 	}
573 
574 	ddr_perf_counter_global_config(pmu, true);
575 
576 	return IRQ_HANDLED;
577 }
578 
579 static int ddr_perf_offline_cpu(unsigned int cpu, struct hlist_node *node)
580 {
581 	struct ddr_pmu *pmu = hlist_entry_safe(node, struct ddr_pmu, node);
582 	int target;
583 
584 	if (cpu != pmu->cpu)
585 		return 0;
586 
587 	target = cpumask_any_but(cpu_online_mask, cpu);
588 	if (target >= nr_cpu_ids)
589 		return 0;
590 
591 	perf_pmu_migrate_context(&pmu->pmu, cpu, target);
592 	pmu->cpu = target;
593 
594 	WARN_ON(irq_set_affinity(pmu->irq, cpumask_of(pmu->cpu)));
595 
596 	return 0;
597 }
598 
599 static int ddr_perf_probe(struct platform_device *pdev)
600 {
601 	struct ddr_pmu *pmu;
602 	void __iomem *base;
603 	int ret, irq;
604 	char *name;
605 
606 	base = devm_platform_ioremap_resource(pdev, 0);
607 	if (IS_ERR(base))
608 		return PTR_ERR(base);
609 
610 	pmu = devm_kzalloc(&pdev->dev, sizeof(*pmu), GFP_KERNEL);
611 	if (!pmu)
612 		return -ENOMEM;
613 
614 	ddr_perf_init(pmu, base, &pdev->dev);
615 
616 	pmu->devtype_data = of_device_get_match_data(&pdev->dev);
617 
618 	platform_set_drvdata(pdev, pmu);
619 
620 	pmu->id = ida_simple_get(&ddr_ida, 0, 0, GFP_KERNEL);
621 	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, DDR_PERF_DEV_NAME "%d", pmu->id);
622 	if (!name) {
623 		ret = -ENOMEM;
624 		goto format_string_err;
625 	}
626 
627 	pmu->cpu = raw_smp_processor_id();
628 	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, DDR_CPUHP_CB_NAME,
629 				      NULL, ddr_perf_offline_cpu);
630 	if (ret < 0) {
631 		dev_err(&pdev->dev, "Failed to add callbacks for multi state\n");
632 		goto cpuhp_state_err;
633 	}
634 	pmu->cpuhp_state = ret;
635 
636 	/* Register the pmu instance for cpu hotplug */
637 	ret = cpuhp_state_add_instance_nocalls(pmu->cpuhp_state, &pmu->node);
638 	if (ret) {
639 		dev_err(&pdev->dev, "Error %d registering hotplug\n", ret);
640 		goto cpuhp_instance_err;
641 	}
642 
643 	/* Request irq */
644 	irq = platform_get_irq(pdev, 0);
645 	if (irq < 0) {
646 		ret = irq;
647 		goto ddr_perf_err;
648 	}
649 
650 	ret = devm_request_irq(&pdev->dev, irq, ddr_perf_irq_handler,
651 			       IRQF_NOBALANCING | IRQF_NO_THREAD,
652 			       DDR_CPUHP_CB_NAME, pmu);
653 	if (ret < 0) {
654 		dev_err(&pdev->dev, "Request irq failed: %d", ret);
655 		goto ddr_perf_err;
656 	}
657 
658 	pmu->irq = irq;
659 	ret = irq_set_affinity(pmu->irq, cpumask_of(pmu->cpu));
660 	if (ret) {
661 		dev_err(pmu->dev, "Failed to set interrupt affinity\n");
662 		goto ddr_perf_err;
663 	}
664 
665 	ret = perf_pmu_register(&pmu->pmu, name, -1);
666 	if (ret)
667 		goto ddr_perf_err;
668 
669 	return 0;
670 
671 ddr_perf_err:
672 	cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
673 cpuhp_instance_err:
674 	cpuhp_remove_multi_state(pmu->cpuhp_state);
675 cpuhp_state_err:
676 format_string_err:
677 	ida_simple_remove(&ddr_ida, pmu->id);
678 	dev_warn(&pdev->dev, "i.MX9 DDR Perf PMU failed (%d), disabled\n", ret);
679 	return ret;
680 }
681 
682 static int ddr_perf_remove(struct platform_device *pdev)
683 {
684 	struct ddr_pmu *pmu = platform_get_drvdata(pdev);
685 
686 	cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
687 	cpuhp_remove_multi_state(pmu->cpuhp_state);
688 
689 	perf_pmu_unregister(&pmu->pmu);
690 
691 	ida_simple_remove(&ddr_ida, pmu->id);
692 
693 	return 0;
694 }
695 
696 static struct platform_driver imx_ddr_pmu_driver = {
697 	.driver         = {
698 		.name                = "imx9-ddr-pmu",
699 		.of_match_table      = imx_ddr_pmu_dt_ids,
700 		.suppress_bind_attrs = true,
701 	},
702 	.probe          = ddr_perf_probe,
703 	.remove         = ddr_perf_remove,
704 };
705 module_platform_driver(imx_ddr_pmu_driver);
706 
707 MODULE_AUTHOR("Xu Yang <xu.yang_2@nxp.com>");
708 MODULE_LICENSE("GPL v2");
709 MODULE_DESCRIPTION("DDRC PerfMon for i.MX9 SoCs");
710