xref: /openbmc/linux/drivers/perf/qcom_l2_pmu.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2015-2017 The Linux Foundation. All rights reserved.
3  */
4 #include <linux/acpi.h>
5 #include <linux/bitops.h>
6 #include <linux/bug.h>
7 #include <linux/cpuhotplug.h>
8 #include <linux/cpumask.h>
9 #include <linux/device.h>
10 #include <linux/errno.h>
11 #include <linux/interrupt.h>
12 #include <linux/irq.h>
13 #include <linux/kernel.h>
14 #include <linux/list.h>
15 #include <linux/percpu.h>
16 #include <linux/perf_event.h>
17 #include <linux/platform_device.h>
18 #include <linux/smp.h>
19 #include <linux/spinlock.h>
20 #include <linux/sysfs.h>
21 #include <linux/types.h>
22 
23 #include <asm/barrier.h>
24 #include <asm/local64.h>
25 #include <asm/sysreg.h>
26 
27 #define MAX_L2_CTRS             9
28 
29 #define L2PMCR_NUM_EV_SHIFT     11
30 #define L2PMCR_NUM_EV_MASK      0x1F
31 
32 #define L2PMCR                  0x400
33 #define L2PMCNTENCLR            0x403
34 #define L2PMCNTENSET            0x404
35 #define L2PMINTENCLR            0x405
36 #define L2PMINTENSET            0x406
37 #define L2PMOVSCLR              0x407
38 #define L2PMOVSSET              0x408
39 #define L2PMCCNTCR              0x409
40 #define L2PMCCNTR               0x40A
41 #define L2PMCCNTSR              0x40C
42 #define L2PMRESR                0x410
43 #define IA_L2PMXEVCNTCR_BASE    0x420
44 #define IA_L2PMXEVCNTR_BASE     0x421
45 #define IA_L2PMXEVFILTER_BASE   0x423
46 #define IA_L2PMXEVTYPER_BASE    0x424
47 
48 #define IA_L2_REG_OFFSET        0x10
49 
50 #define L2PMXEVFILTER_SUFILTER_ALL      0x000E0000
51 #define L2PMXEVFILTER_ORGFILTER_IDINDEP 0x00000004
52 #define L2PMXEVFILTER_ORGFILTER_ALL     0x00000003
53 
54 #define L2EVTYPER_REG_SHIFT     3
55 
56 #define L2PMRESR_GROUP_BITS     8
57 #define L2PMRESR_GROUP_MASK     GENMASK(7, 0)
58 
59 #define L2CYCLE_CTR_BIT         31
60 #define L2CYCLE_CTR_RAW_CODE    0xFE
61 
62 #define L2PMCR_RESET_ALL        0x6
63 #define L2PMCR_COUNTERS_ENABLE  0x1
64 #define L2PMCR_COUNTERS_DISABLE 0x0
65 
66 #define L2PMRESR_EN             BIT_ULL(63)
67 
68 #define L2_EVT_MASK             0x00000FFF
69 #define L2_EVT_CODE_MASK        0x00000FF0
70 #define L2_EVT_GRP_MASK         0x0000000F
71 #define L2_EVT_CODE_SHIFT       4
72 #define L2_EVT_GRP_SHIFT        0
73 
74 #define L2_EVT_CODE(event)   (((event) & L2_EVT_CODE_MASK) >> L2_EVT_CODE_SHIFT)
75 #define L2_EVT_GROUP(event)  (((event) & L2_EVT_GRP_MASK) >> L2_EVT_GRP_SHIFT)
76 
77 #define L2_EVT_GROUP_MAX        7
78 
79 #define L2_COUNTER_RELOAD       BIT_ULL(31)
80 #define L2_CYCLE_COUNTER_RELOAD BIT_ULL(63)
81 
82 #define L2CPUSRSELR_EL1         sys_reg(3, 3, 15, 0, 6)
83 #define L2CPUSRDR_EL1           sys_reg(3, 3, 15, 0, 7)
84 
85 #define reg_idx(reg, i)         (((i) * IA_L2_REG_OFFSET) + reg##_BASE)
86 
87 /*
88  * Events
89  */
90 #define L2_EVENT_CYCLES                    0xfe
91 #define L2_EVENT_DCACHE_OPS                0x400
92 #define L2_EVENT_ICACHE_OPS                0x401
93 #define L2_EVENT_TLBI                      0x402
94 #define L2_EVENT_BARRIERS                  0x403
95 #define L2_EVENT_TOTAL_READS               0x405
96 #define L2_EVENT_TOTAL_WRITES              0x406
97 #define L2_EVENT_TOTAL_REQUESTS            0x407
98 #define L2_EVENT_LDREX                     0x420
99 #define L2_EVENT_STREX                     0x421
100 #define L2_EVENT_CLREX                     0x422
101 
102 static DEFINE_RAW_SPINLOCK(l2_access_lock);
103 
104 /**
105  * set_l2_indirect_reg: write value to an L2 register
106  * @reg: Address of L2 register.
107  * @value: Value to be written to register.
108  *
109  * Use architecturally required barriers for ordering between system register
110  * accesses
111  */
112 static void set_l2_indirect_reg(u64 reg, u64 val)
113 {
114 	unsigned long flags;
115 
116 	raw_spin_lock_irqsave(&l2_access_lock, flags);
117 	write_sysreg_s(reg, L2CPUSRSELR_EL1);
118 	isb();
119 	write_sysreg_s(val, L2CPUSRDR_EL1);
120 	isb();
121 	raw_spin_unlock_irqrestore(&l2_access_lock, flags);
122 }
123 
124 /**
125  * get_l2_indirect_reg: read an L2 register value
126  * @reg: Address of L2 register.
127  *
128  * Use architecturally required barriers for ordering between system register
129  * accesses
130  */
131 static u64 get_l2_indirect_reg(u64 reg)
132 {
133 	u64 val;
134 	unsigned long flags;
135 
136 	raw_spin_lock_irqsave(&l2_access_lock, flags);
137 	write_sysreg_s(reg, L2CPUSRSELR_EL1);
138 	isb();
139 	val = read_sysreg_s(L2CPUSRDR_EL1);
140 	raw_spin_unlock_irqrestore(&l2_access_lock, flags);
141 
142 	return val;
143 }
144 
145 struct cluster_pmu;
146 
147 /*
148  * Aggregate PMU. Implements the core pmu functions and manages
149  * the hardware PMUs.
150  */
151 struct l2cache_pmu {
152 	struct hlist_node node;
153 	u32 num_pmus;
154 	struct pmu pmu;
155 	int num_counters;
156 	cpumask_t cpumask;
157 	struct platform_device *pdev;
158 	struct cluster_pmu * __percpu *pmu_cluster;
159 	struct list_head clusters;
160 };
161 
162 /*
163  * The cache is made up of one or more clusters, each cluster has its own PMU.
164  * Each cluster is associated with one or more CPUs.
165  * This structure represents one of the hardware PMUs.
166  *
167  * Events can be envisioned as a 2-dimensional array. Each column represents
168  * a group of events. There are 8 groups. Only one entry from each
169  * group can be in use at a time.
170  *
171  * Events are specified as 0xCCG, where CC is 2 hex digits specifying
172  * the code (array row) and G specifies the group (column).
173  *
174  * In addition there is a cycle counter event specified by L2CYCLE_CTR_RAW_CODE
175  * which is outside the above scheme.
176  */
177 struct cluster_pmu {
178 	struct list_head next;
179 	struct perf_event *events[MAX_L2_CTRS];
180 	struct l2cache_pmu *l2cache_pmu;
181 	DECLARE_BITMAP(used_counters, MAX_L2_CTRS);
182 	DECLARE_BITMAP(used_groups, L2_EVT_GROUP_MAX + 1);
183 	int irq;
184 	int cluster_id;
185 	/* The CPU that is used for collecting events on this cluster */
186 	int on_cpu;
187 	/* All the CPUs associated with this cluster */
188 	cpumask_t cluster_cpus;
189 	spinlock_t pmu_lock;
190 };
191 
192 #define to_l2cache_pmu(p) (container_of(p, struct l2cache_pmu, pmu))
193 
194 static u32 l2_cycle_ctr_idx;
195 static u32 l2_counter_present_mask;
196 
197 static inline u32 idx_to_reg_bit(u32 idx)
198 {
199 	if (idx == l2_cycle_ctr_idx)
200 		return BIT(L2CYCLE_CTR_BIT);
201 
202 	return BIT(idx);
203 }
204 
205 static inline struct cluster_pmu *get_cluster_pmu(
206 	struct l2cache_pmu *l2cache_pmu, int cpu)
207 {
208 	return *per_cpu_ptr(l2cache_pmu->pmu_cluster, cpu);
209 }
210 
211 static void cluster_pmu_reset(void)
212 {
213 	/* Reset all counters */
214 	set_l2_indirect_reg(L2PMCR, L2PMCR_RESET_ALL);
215 	set_l2_indirect_reg(L2PMCNTENCLR, l2_counter_present_mask);
216 	set_l2_indirect_reg(L2PMINTENCLR, l2_counter_present_mask);
217 	set_l2_indirect_reg(L2PMOVSCLR, l2_counter_present_mask);
218 }
219 
220 static inline void cluster_pmu_enable(void)
221 {
222 	set_l2_indirect_reg(L2PMCR, L2PMCR_COUNTERS_ENABLE);
223 }
224 
225 static inline void cluster_pmu_disable(void)
226 {
227 	set_l2_indirect_reg(L2PMCR, L2PMCR_COUNTERS_DISABLE);
228 }
229 
230 static inline void cluster_pmu_counter_set_value(u32 idx, u64 value)
231 {
232 	if (idx == l2_cycle_ctr_idx)
233 		set_l2_indirect_reg(L2PMCCNTR, value);
234 	else
235 		set_l2_indirect_reg(reg_idx(IA_L2PMXEVCNTR, idx), value);
236 }
237 
238 static inline u64 cluster_pmu_counter_get_value(u32 idx)
239 {
240 	u64 value;
241 
242 	if (idx == l2_cycle_ctr_idx)
243 		value = get_l2_indirect_reg(L2PMCCNTR);
244 	else
245 		value = get_l2_indirect_reg(reg_idx(IA_L2PMXEVCNTR, idx));
246 
247 	return value;
248 }
249 
250 static inline void cluster_pmu_counter_enable(u32 idx)
251 {
252 	set_l2_indirect_reg(L2PMCNTENSET, idx_to_reg_bit(idx));
253 }
254 
255 static inline void cluster_pmu_counter_disable(u32 idx)
256 {
257 	set_l2_indirect_reg(L2PMCNTENCLR, idx_to_reg_bit(idx));
258 }
259 
260 static inline void cluster_pmu_counter_enable_interrupt(u32 idx)
261 {
262 	set_l2_indirect_reg(L2PMINTENSET, idx_to_reg_bit(idx));
263 }
264 
265 static inline void cluster_pmu_counter_disable_interrupt(u32 idx)
266 {
267 	set_l2_indirect_reg(L2PMINTENCLR, idx_to_reg_bit(idx));
268 }
269 
270 static inline void cluster_pmu_set_evccntcr(u32 val)
271 {
272 	set_l2_indirect_reg(L2PMCCNTCR, val);
273 }
274 
275 static inline void cluster_pmu_set_evcntcr(u32 ctr, u32 val)
276 {
277 	set_l2_indirect_reg(reg_idx(IA_L2PMXEVCNTCR, ctr), val);
278 }
279 
280 static inline void cluster_pmu_set_evtyper(u32 ctr, u32 val)
281 {
282 	set_l2_indirect_reg(reg_idx(IA_L2PMXEVTYPER, ctr), val);
283 }
284 
285 static void cluster_pmu_set_resr(struct cluster_pmu *cluster,
286 			       u32 event_group, u32 event_cc)
287 {
288 	u64 field;
289 	u64 resr_val;
290 	u32 shift;
291 	unsigned long flags;
292 
293 	shift = L2PMRESR_GROUP_BITS * event_group;
294 	field = ((u64)(event_cc & L2PMRESR_GROUP_MASK) << shift);
295 
296 	spin_lock_irqsave(&cluster->pmu_lock, flags);
297 
298 	resr_val = get_l2_indirect_reg(L2PMRESR);
299 	resr_val &= ~(L2PMRESR_GROUP_MASK << shift);
300 	resr_val |= field;
301 	resr_val |= L2PMRESR_EN;
302 	set_l2_indirect_reg(L2PMRESR, resr_val);
303 
304 	spin_unlock_irqrestore(&cluster->pmu_lock, flags);
305 }
306 
307 /*
308  * Hardware allows filtering of events based on the originating
309  * CPU. Turn this off by setting filter bits to allow events from
310  * all CPUS, subunits and ID independent events in this cluster.
311  */
312 static inline void cluster_pmu_set_evfilter_sys_mode(u32 ctr)
313 {
314 	u32 val =  L2PMXEVFILTER_SUFILTER_ALL |
315 		   L2PMXEVFILTER_ORGFILTER_IDINDEP |
316 		   L2PMXEVFILTER_ORGFILTER_ALL;
317 
318 	set_l2_indirect_reg(reg_idx(IA_L2PMXEVFILTER, ctr), val);
319 }
320 
321 static inline u32 cluster_pmu_getreset_ovsr(void)
322 {
323 	u32 result = get_l2_indirect_reg(L2PMOVSSET);
324 
325 	set_l2_indirect_reg(L2PMOVSCLR, result);
326 	return result;
327 }
328 
329 static inline bool cluster_pmu_has_overflowed(u32 ovsr)
330 {
331 	return !!(ovsr & l2_counter_present_mask);
332 }
333 
334 static inline bool cluster_pmu_counter_has_overflowed(u32 ovsr, u32 idx)
335 {
336 	return !!(ovsr & idx_to_reg_bit(idx));
337 }
338 
339 static void l2_cache_event_update(struct perf_event *event)
340 {
341 	struct hw_perf_event *hwc = &event->hw;
342 	u64 delta, prev, now;
343 	u32 idx = hwc->idx;
344 
345 	do {
346 		prev = local64_read(&hwc->prev_count);
347 		now = cluster_pmu_counter_get_value(idx);
348 	} while (local64_cmpxchg(&hwc->prev_count, prev, now) != prev);
349 
350 	/*
351 	 * The cycle counter is 64-bit, but all other counters are
352 	 * 32-bit, and we must handle 32-bit overflow explicitly.
353 	 */
354 	delta = now - prev;
355 	if (idx != l2_cycle_ctr_idx)
356 		delta &= 0xffffffff;
357 
358 	local64_add(delta, &event->count);
359 }
360 
361 static void l2_cache_cluster_set_period(struct cluster_pmu *cluster,
362 				       struct hw_perf_event *hwc)
363 {
364 	u32 idx = hwc->idx;
365 	u64 new;
366 
367 	/*
368 	 * We limit the max period to half the max counter value so
369 	 * that even in the case of extreme interrupt latency the
370 	 * counter will (hopefully) not wrap past its initial value.
371 	 */
372 	if (idx == l2_cycle_ctr_idx)
373 		new = L2_CYCLE_COUNTER_RELOAD;
374 	else
375 		new = L2_COUNTER_RELOAD;
376 
377 	local64_set(&hwc->prev_count, new);
378 	cluster_pmu_counter_set_value(idx, new);
379 }
380 
381 static int l2_cache_get_event_idx(struct cluster_pmu *cluster,
382 				   struct perf_event *event)
383 {
384 	struct hw_perf_event *hwc = &event->hw;
385 	int idx;
386 	int num_ctrs = cluster->l2cache_pmu->num_counters - 1;
387 	unsigned int group;
388 
389 	if (hwc->config_base == L2CYCLE_CTR_RAW_CODE) {
390 		if (test_and_set_bit(l2_cycle_ctr_idx, cluster->used_counters))
391 			return -EAGAIN;
392 
393 		return l2_cycle_ctr_idx;
394 	}
395 
396 	idx = find_first_zero_bit(cluster->used_counters, num_ctrs);
397 	if (idx == num_ctrs)
398 		/* The counters are all in use. */
399 		return -EAGAIN;
400 
401 	/*
402 	 * Check for column exclusion: event column already in use by another
403 	 * event. This is for events which are not in the same group.
404 	 * Conflicting events in the same group are detected in event_init.
405 	 */
406 	group = L2_EVT_GROUP(hwc->config_base);
407 	if (test_bit(group, cluster->used_groups))
408 		return -EAGAIN;
409 
410 	set_bit(idx, cluster->used_counters);
411 	set_bit(group, cluster->used_groups);
412 
413 	return idx;
414 }
415 
416 static void l2_cache_clear_event_idx(struct cluster_pmu *cluster,
417 				      struct perf_event *event)
418 {
419 	struct hw_perf_event *hwc = &event->hw;
420 	int idx = hwc->idx;
421 
422 	clear_bit(idx, cluster->used_counters);
423 	if (hwc->config_base != L2CYCLE_CTR_RAW_CODE)
424 		clear_bit(L2_EVT_GROUP(hwc->config_base), cluster->used_groups);
425 }
426 
427 static irqreturn_t l2_cache_handle_irq(int irq_num, void *data)
428 {
429 	struct cluster_pmu *cluster = data;
430 	int num_counters = cluster->l2cache_pmu->num_counters;
431 	u32 ovsr;
432 	int idx;
433 
434 	ovsr = cluster_pmu_getreset_ovsr();
435 	if (!cluster_pmu_has_overflowed(ovsr))
436 		return IRQ_NONE;
437 
438 	for_each_set_bit(idx, cluster->used_counters, num_counters) {
439 		struct perf_event *event = cluster->events[idx];
440 		struct hw_perf_event *hwc;
441 
442 		if (WARN_ON_ONCE(!event))
443 			continue;
444 
445 		if (!cluster_pmu_counter_has_overflowed(ovsr, idx))
446 			continue;
447 
448 		l2_cache_event_update(event);
449 		hwc = &event->hw;
450 
451 		l2_cache_cluster_set_period(cluster, hwc);
452 	}
453 
454 	return IRQ_HANDLED;
455 }
456 
457 /*
458  * Implementation of abstract pmu functionality required by
459  * the core perf events code.
460  */
461 
462 static void l2_cache_pmu_enable(struct pmu *pmu)
463 {
464 	/*
465 	 * Although there is only one PMU (per socket) controlling multiple
466 	 * physical PMUs (per cluster), because we do not support per-task mode
467 	 * each event is associated with a CPU. Each event has pmu_enable
468 	 * called on its CPU, so here it is only necessary to enable the
469 	 * counters for the current CPU.
470 	 */
471 
472 	cluster_pmu_enable();
473 }
474 
475 static void l2_cache_pmu_disable(struct pmu *pmu)
476 {
477 	cluster_pmu_disable();
478 }
479 
480 static int l2_cache_event_init(struct perf_event *event)
481 {
482 	struct hw_perf_event *hwc = &event->hw;
483 	struct cluster_pmu *cluster;
484 	struct perf_event *sibling;
485 	struct l2cache_pmu *l2cache_pmu;
486 
487 	if (event->attr.type != event->pmu->type)
488 		return -ENOENT;
489 
490 	l2cache_pmu = to_l2cache_pmu(event->pmu);
491 
492 	if (hwc->sample_period) {
493 		dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
494 				    "Sampling not supported\n");
495 		return -EOPNOTSUPP;
496 	}
497 
498 	if (event->cpu < 0) {
499 		dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
500 				    "Per-task mode not supported\n");
501 		return -EOPNOTSUPP;
502 	}
503 
504 	if (((L2_EVT_GROUP(event->attr.config) > L2_EVT_GROUP_MAX) ||
505 	     ((event->attr.config & ~L2_EVT_MASK) != 0)) &&
506 	    (event->attr.config != L2CYCLE_CTR_RAW_CODE)) {
507 		dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
508 				    "Invalid config %llx\n",
509 				    event->attr.config);
510 		return -EINVAL;
511 	}
512 
513 	/* Don't allow groups with mixed PMUs, except for s/w events */
514 	if (event->group_leader->pmu != event->pmu &&
515 	    !is_software_event(event->group_leader)) {
516 		dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
517 			 "Can't create mixed PMU group\n");
518 		return -EINVAL;
519 	}
520 
521 	for_each_sibling_event(sibling, event->group_leader) {
522 		if (sibling->pmu != event->pmu &&
523 		    !is_software_event(sibling)) {
524 			dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
525 				 "Can't create mixed PMU group\n");
526 			return -EINVAL;
527 		}
528 	}
529 
530 	cluster = get_cluster_pmu(l2cache_pmu, event->cpu);
531 	if (!cluster) {
532 		/* CPU has not been initialised */
533 		dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
534 			"CPU%d not associated with L2 cluster\n", event->cpu);
535 		return -EINVAL;
536 	}
537 
538 	/* Ensure all events in a group are on the same cpu */
539 	if ((event->group_leader != event) &&
540 	    (cluster->on_cpu != event->group_leader->cpu)) {
541 		dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
542 			 "Can't create group on CPUs %d and %d",
543 			 event->cpu, event->group_leader->cpu);
544 		return -EINVAL;
545 	}
546 
547 	if ((event != event->group_leader) &&
548 	    !is_software_event(event->group_leader) &&
549 	    (L2_EVT_GROUP(event->group_leader->attr.config) ==
550 	     L2_EVT_GROUP(event->attr.config))) {
551 		dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
552 			 "Column exclusion: conflicting events %llx %llx\n",
553 		       event->group_leader->attr.config,
554 		       event->attr.config);
555 		return -EINVAL;
556 	}
557 
558 	for_each_sibling_event(sibling, event->group_leader) {
559 		if ((sibling != event) &&
560 		    !is_software_event(sibling) &&
561 		    (L2_EVT_GROUP(sibling->attr.config) ==
562 		     L2_EVT_GROUP(event->attr.config))) {
563 			dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
564 			     "Column exclusion: conflicting events %llx %llx\n",
565 					    sibling->attr.config,
566 					    event->attr.config);
567 			return -EINVAL;
568 		}
569 	}
570 
571 	hwc->idx = -1;
572 	hwc->config_base = event->attr.config;
573 
574 	/*
575 	 * Ensure all events are on the same cpu so all events are in the
576 	 * same cpu context, to avoid races on pmu_enable etc.
577 	 */
578 	event->cpu = cluster->on_cpu;
579 
580 	return 0;
581 }
582 
583 static void l2_cache_event_start(struct perf_event *event, int flags)
584 {
585 	struct cluster_pmu *cluster;
586 	struct hw_perf_event *hwc = &event->hw;
587 	int idx = hwc->idx;
588 	u32 config;
589 	u32 event_cc, event_group;
590 
591 	hwc->state = 0;
592 
593 	cluster = get_cluster_pmu(to_l2cache_pmu(event->pmu), event->cpu);
594 
595 	l2_cache_cluster_set_period(cluster, hwc);
596 
597 	if (hwc->config_base == L2CYCLE_CTR_RAW_CODE) {
598 		cluster_pmu_set_evccntcr(0);
599 	} else {
600 		config = hwc->config_base;
601 		event_cc    = L2_EVT_CODE(config);
602 		event_group = L2_EVT_GROUP(config);
603 
604 		cluster_pmu_set_evcntcr(idx, 0);
605 		cluster_pmu_set_evtyper(idx, event_group);
606 		cluster_pmu_set_resr(cluster, event_group, event_cc);
607 		cluster_pmu_set_evfilter_sys_mode(idx);
608 	}
609 
610 	cluster_pmu_counter_enable_interrupt(idx);
611 	cluster_pmu_counter_enable(idx);
612 }
613 
614 static void l2_cache_event_stop(struct perf_event *event, int flags)
615 {
616 	struct hw_perf_event *hwc = &event->hw;
617 	int idx = hwc->idx;
618 
619 	if (hwc->state & PERF_HES_STOPPED)
620 		return;
621 
622 	cluster_pmu_counter_disable_interrupt(idx);
623 	cluster_pmu_counter_disable(idx);
624 
625 	if (flags & PERF_EF_UPDATE)
626 		l2_cache_event_update(event);
627 	hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
628 }
629 
630 static int l2_cache_event_add(struct perf_event *event, int flags)
631 {
632 	struct hw_perf_event *hwc = &event->hw;
633 	int idx;
634 	int err = 0;
635 	struct cluster_pmu *cluster;
636 
637 	cluster = get_cluster_pmu(to_l2cache_pmu(event->pmu), event->cpu);
638 
639 	idx = l2_cache_get_event_idx(cluster, event);
640 	if (idx < 0)
641 		return idx;
642 
643 	hwc->idx = idx;
644 	hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
645 	cluster->events[idx] = event;
646 	local64_set(&hwc->prev_count, 0);
647 
648 	if (flags & PERF_EF_START)
649 		l2_cache_event_start(event, flags);
650 
651 	/* Propagate changes to the userspace mapping. */
652 	perf_event_update_userpage(event);
653 
654 	return err;
655 }
656 
657 static void l2_cache_event_del(struct perf_event *event, int flags)
658 {
659 	struct hw_perf_event *hwc = &event->hw;
660 	struct cluster_pmu *cluster;
661 	int idx = hwc->idx;
662 
663 	cluster = get_cluster_pmu(to_l2cache_pmu(event->pmu), event->cpu);
664 
665 	l2_cache_event_stop(event, flags | PERF_EF_UPDATE);
666 	cluster->events[idx] = NULL;
667 	l2_cache_clear_event_idx(cluster, event);
668 
669 	perf_event_update_userpage(event);
670 }
671 
672 static void l2_cache_event_read(struct perf_event *event)
673 {
674 	l2_cache_event_update(event);
675 }
676 
677 static ssize_t l2_cache_pmu_cpumask_show(struct device *dev,
678 					 struct device_attribute *attr,
679 					 char *buf)
680 {
681 	struct l2cache_pmu *l2cache_pmu = to_l2cache_pmu(dev_get_drvdata(dev));
682 
683 	return cpumap_print_to_pagebuf(true, buf, &l2cache_pmu->cpumask);
684 }
685 
686 static struct device_attribute l2_cache_pmu_cpumask_attr =
687 		__ATTR(cpumask, S_IRUGO, l2_cache_pmu_cpumask_show, NULL);
688 
689 static struct attribute *l2_cache_pmu_cpumask_attrs[] = {
690 	&l2_cache_pmu_cpumask_attr.attr,
691 	NULL,
692 };
693 
694 static struct attribute_group l2_cache_pmu_cpumask_group = {
695 	.attrs = l2_cache_pmu_cpumask_attrs,
696 };
697 
698 /* CCG format for perf RAW codes. */
699 PMU_FORMAT_ATTR(l2_code,   "config:4-11");
700 PMU_FORMAT_ATTR(l2_group,  "config:0-3");
701 PMU_FORMAT_ATTR(event,     "config:0-11");
702 
703 static struct attribute *l2_cache_pmu_formats[] = {
704 	&format_attr_l2_code.attr,
705 	&format_attr_l2_group.attr,
706 	&format_attr_event.attr,
707 	NULL,
708 };
709 
710 static struct attribute_group l2_cache_pmu_format_group = {
711 	.name = "format",
712 	.attrs = l2_cache_pmu_formats,
713 };
714 
715 static ssize_t l2cache_pmu_event_show(struct device *dev,
716 				      struct device_attribute *attr, char *page)
717 {
718 	struct perf_pmu_events_attr *pmu_attr;
719 
720 	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
721 	return sprintf(page, "event=0x%02llx\n", pmu_attr->id);
722 }
723 
724 #define L2CACHE_EVENT_ATTR(_name, _id)					     \
725 	(&((struct perf_pmu_events_attr[]) {				     \
726 		{ .attr = __ATTR(_name, 0444, l2cache_pmu_event_show, NULL), \
727 		  .id = _id, }						     \
728 	})[0].attr.attr)
729 
730 static struct attribute *l2_cache_pmu_events[] = {
731 	L2CACHE_EVENT_ATTR(cycles, L2_EVENT_CYCLES),
732 	L2CACHE_EVENT_ATTR(dcache-ops, L2_EVENT_DCACHE_OPS),
733 	L2CACHE_EVENT_ATTR(icache-ops, L2_EVENT_ICACHE_OPS),
734 	L2CACHE_EVENT_ATTR(tlbi, L2_EVENT_TLBI),
735 	L2CACHE_EVENT_ATTR(barriers, L2_EVENT_BARRIERS),
736 	L2CACHE_EVENT_ATTR(total-reads, L2_EVENT_TOTAL_READS),
737 	L2CACHE_EVENT_ATTR(total-writes, L2_EVENT_TOTAL_WRITES),
738 	L2CACHE_EVENT_ATTR(total-requests, L2_EVENT_TOTAL_REQUESTS),
739 	L2CACHE_EVENT_ATTR(ldrex, L2_EVENT_LDREX),
740 	L2CACHE_EVENT_ATTR(strex, L2_EVENT_STREX),
741 	L2CACHE_EVENT_ATTR(clrex, L2_EVENT_CLREX),
742 	NULL
743 };
744 
745 static struct attribute_group l2_cache_pmu_events_group = {
746 	.name = "events",
747 	.attrs = l2_cache_pmu_events,
748 };
749 
750 static const struct attribute_group *l2_cache_pmu_attr_grps[] = {
751 	&l2_cache_pmu_format_group,
752 	&l2_cache_pmu_cpumask_group,
753 	&l2_cache_pmu_events_group,
754 	NULL,
755 };
756 
757 /*
758  * Generic device handlers
759  */
760 
761 static const struct acpi_device_id l2_cache_pmu_acpi_match[] = {
762 	{ "QCOM8130", },
763 	{ }
764 };
765 
766 static int get_num_counters(void)
767 {
768 	int val;
769 
770 	val = get_l2_indirect_reg(L2PMCR);
771 
772 	/*
773 	 * Read number of counters from L2PMCR and add 1
774 	 * for the cycle counter.
775 	 */
776 	return ((val >> L2PMCR_NUM_EV_SHIFT) & L2PMCR_NUM_EV_MASK) + 1;
777 }
778 
779 static struct cluster_pmu *l2_cache_associate_cpu_with_cluster(
780 	struct l2cache_pmu *l2cache_pmu, int cpu)
781 {
782 	u64 mpidr;
783 	int cpu_cluster_id;
784 	struct cluster_pmu *cluster = NULL;
785 
786 	/*
787 	 * This assumes that the cluster_id is in MPIDR[aff1] for
788 	 * single-threaded cores, and MPIDR[aff2] for multi-threaded
789 	 * cores. This logic will have to be updated if this changes.
790 	 */
791 	mpidr = read_cpuid_mpidr();
792 	if (mpidr & MPIDR_MT_BITMASK)
793 		cpu_cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 2);
794 	else
795 		cpu_cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 1);
796 
797 	list_for_each_entry(cluster, &l2cache_pmu->clusters, next) {
798 		if (cluster->cluster_id != cpu_cluster_id)
799 			continue;
800 
801 		dev_info(&l2cache_pmu->pdev->dev,
802 			 "CPU%d associated with cluster %d\n", cpu,
803 			 cluster->cluster_id);
804 		cpumask_set_cpu(cpu, &cluster->cluster_cpus);
805 		*per_cpu_ptr(l2cache_pmu->pmu_cluster, cpu) = cluster;
806 		break;
807 	}
808 
809 	return cluster;
810 }
811 
812 static int l2cache_pmu_online_cpu(unsigned int cpu, struct hlist_node *node)
813 {
814 	struct cluster_pmu *cluster;
815 	struct l2cache_pmu *l2cache_pmu;
816 
817 	l2cache_pmu = hlist_entry_safe(node, struct l2cache_pmu, node);
818 	cluster = get_cluster_pmu(l2cache_pmu, cpu);
819 	if (!cluster) {
820 		/* First time this CPU has come online */
821 		cluster = l2_cache_associate_cpu_with_cluster(l2cache_pmu, cpu);
822 		if (!cluster) {
823 			/* Only if broken firmware doesn't list every cluster */
824 			WARN_ONCE(1, "No L2 cache cluster for CPU%d\n", cpu);
825 			return 0;
826 		}
827 	}
828 
829 	/* If another CPU is managing this cluster, we're done */
830 	if (cluster->on_cpu != -1)
831 		return 0;
832 
833 	/*
834 	 * All CPUs on this cluster were down, use this one.
835 	 * Reset to put it into sane state.
836 	 */
837 	cluster->on_cpu = cpu;
838 	cpumask_set_cpu(cpu, &l2cache_pmu->cpumask);
839 	cluster_pmu_reset();
840 
841 	WARN_ON(irq_set_affinity(cluster->irq, cpumask_of(cpu)));
842 	enable_irq(cluster->irq);
843 
844 	return 0;
845 }
846 
847 static int l2cache_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
848 {
849 	struct cluster_pmu *cluster;
850 	struct l2cache_pmu *l2cache_pmu;
851 	cpumask_t cluster_online_cpus;
852 	unsigned int target;
853 
854 	l2cache_pmu = hlist_entry_safe(node, struct l2cache_pmu, node);
855 	cluster = get_cluster_pmu(l2cache_pmu, cpu);
856 	if (!cluster)
857 		return 0;
858 
859 	/* If this CPU is not managing the cluster, we're done */
860 	if (cluster->on_cpu != cpu)
861 		return 0;
862 
863 	/* Give up ownership of cluster */
864 	cpumask_clear_cpu(cpu, &l2cache_pmu->cpumask);
865 	cluster->on_cpu = -1;
866 
867 	/* Any other CPU for this cluster which is still online */
868 	cpumask_and(&cluster_online_cpus, &cluster->cluster_cpus,
869 		    cpu_online_mask);
870 	target = cpumask_any_but(&cluster_online_cpus, cpu);
871 	if (target >= nr_cpu_ids) {
872 		disable_irq(cluster->irq);
873 		return 0;
874 	}
875 
876 	perf_pmu_migrate_context(&l2cache_pmu->pmu, cpu, target);
877 	cluster->on_cpu = target;
878 	cpumask_set_cpu(target, &l2cache_pmu->cpumask);
879 	WARN_ON(irq_set_affinity(cluster->irq, cpumask_of(target)));
880 
881 	return 0;
882 }
883 
884 static int l2_cache_pmu_probe_cluster(struct device *dev, void *data)
885 {
886 	struct platform_device *pdev = to_platform_device(dev->parent);
887 	struct platform_device *sdev = to_platform_device(dev);
888 	struct l2cache_pmu *l2cache_pmu = data;
889 	struct cluster_pmu *cluster;
890 	struct acpi_device *device;
891 	unsigned long fw_cluster_id;
892 	int err;
893 	int irq;
894 
895 	if (acpi_bus_get_device(ACPI_HANDLE(dev), &device))
896 		return -ENODEV;
897 
898 	if (kstrtoul(device->pnp.unique_id, 10, &fw_cluster_id) < 0) {
899 		dev_err(&pdev->dev, "unable to read ACPI uid\n");
900 		return -ENODEV;
901 	}
902 
903 	cluster = devm_kzalloc(&pdev->dev, sizeof(*cluster), GFP_KERNEL);
904 	if (!cluster)
905 		return -ENOMEM;
906 
907 	INIT_LIST_HEAD(&cluster->next);
908 	list_add(&cluster->next, &l2cache_pmu->clusters);
909 	cluster->cluster_id = fw_cluster_id;
910 
911 	irq = platform_get_irq(sdev, 0);
912 	if (irq < 0)
913 		return irq;
914 	irq_set_status_flags(irq, IRQ_NOAUTOEN);
915 	cluster->irq = irq;
916 
917 	cluster->l2cache_pmu = l2cache_pmu;
918 	cluster->on_cpu = -1;
919 
920 	err = devm_request_irq(&pdev->dev, irq, l2_cache_handle_irq,
921 			       IRQF_NOBALANCING | IRQF_NO_THREAD,
922 			       "l2-cache-pmu", cluster);
923 	if (err) {
924 		dev_err(&pdev->dev,
925 			"Unable to request IRQ%d for L2 PMU counters\n", irq);
926 		return err;
927 	}
928 
929 	dev_info(&pdev->dev,
930 		"Registered L2 cache PMU cluster %ld\n", fw_cluster_id);
931 
932 	spin_lock_init(&cluster->pmu_lock);
933 
934 	l2cache_pmu->num_pmus++;
935 
936 	return 0;
937 }
938 
939 static int l2_cache_pmu_probe(struct platform_device *pdev)
940 {
941 	int err;
942 	struct l2cache_pmu *l2cache_pmu;
943 
944 	l2cache_pmu =
945 		devm_kzalloc(&pdev->dev, sizeof(*l2cache_pmu), GFP_KERNEL);
946 	if (!l2cache_pmu)
947 		return -ENOMEM;
948 
949 	INIT_LIST_HEAD(&l2cache_pmu->clusters);
950 
951 	platform_set_drvdata(pdev, l2cache_pmu);
952 	l2cache_pmu->pmu = (struct pmu) {
953 		/* suffix is instance id for future use with multiple sockets */
954 		.name		= "l2cache_0",
955 		.task_ctx_nr    = perf_invalid_context,
956 		.pmu_enable	= l2_cache_pmu_enable,
957 		.pmu_disable	= l2_cache_pmu_disable,
958 		.event_init	= l2_cache_event_init,
959 		.add		= l2_cache_event_add,
960 		.del		= l2_cache_event_del,
961 		.start		= l2_cache_event_start,
962 		.stop		= l2_cache_event_stop,
963 		.read		= l2_cache_event_read,
964 		.attr_groups	= l2_cache_pmu_attr_grps,
965 		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
966 	};
967 
968 	l2cache_pmu->num_counters = get_num_counters();
969 	l2cache_pmu->pdev = pdev;
970 	l2cache_pmu->pmu_cluster = devm_alloc_percpu(&pdev->dev,
971 						     struct cluster_pmu *);
972 	if (!l2cache_pmu->pmu_cluster)
973 		return -ENOMEM;
974 
975 	l2_cycle_ctr_idx = l2cache_pmu->num_counters - 1;
976 	l2_counter_present_mask = GENMASK(l2cache_pmu->num_counters - 2, 0) |
977 		BIT(L2CYCLE_CTR_BIT);
978 
979 	cpumask_clear(&l2cache_pmu->cpumask);
980 
981 	/* Read cluster info and initialize each cluster */
982 	err = device_for_each_child(&pdev->dev, l2cache_pmu,
983 				    l2_cache_pmu_probe_cluster);
984 	if (err)
985 		return err;
986 
987 	if (l2cache_pmu->num_pmus == 0) {
988 		dev_err(&pdev->dev, "No hardware L2 cache PMUs found\n");
989 		return -ENODEV;
990 	}
991 
992 	err = cpuhp_state_add_instance(CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
993 				       &l2cache_pmu->node);
994 	if (err) {
995 		dev_err(&pdev->dev, "Error %d registering hotplug", err);
996 		return err;
997 	}
998 
999 	err = perf_pmu_register(&l2cache_pmu->pmu, l2cache_pmu->pmu.name, -1);
1000 	if (err) {
1001 		dev_err(&pdev->dev, "Error %d registering L2 cache PMU\n", err);
1002 		goto out_unregister;
1003 	}
1004 
1005 	dev_info(&pdev->dev, "Registered L2 cache PMU using %d HW PMUs\n",
1006 		 l2cache_pmu->num_pmus);
1007 
1008 	return err;
1009 
1010 out_unregister:
1011 	cpuhp_state_remove_instance(CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
1012 				    &l2cache_pmu->node);
1013 	return err;
1014 }
1015 
1016 static int l2_cache_pmu_remove(struct platform_device *pdev)
1017 {
1018 	struct l2cache_pmu *l2cache_pmu =
1019 		to_l2cache_pmu(platform_get_drvdata(pdev));
1020 
1021 	perf_pmu_unregister(&l2cache_pmu->pmu);
1022 	cpuhp_state_remove_instance(CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
1023 				    &l2cache_pmu->node);
1024 	return 0;
1025 }
1026 
1027 static struct platform_driver l2_cache_pmu_driver = {
1028 	.driver = {
1029 		.name = "qcom-l2cache-pmu",
1030 		.acpi_match_table = ACPI_PTR(l2_cache_pmu_acpi_match),
1031 	},
1032 	.probe = l2_cache_pmu_probe,
1033 	.remove = l2_cache_pmu_remove,
1034 };
1035 
1036 static int __init register_l2_cache_pmu_driver(void)
1037 {
1038 	int err;
1039 
1040 	err = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
1041 				      "AP_PERF_ARM_QCOM_L2_ONLINE",
1042 				      l2cache_pmu_online_cpu,
1043 				      l2cache_pmu_offline_cpu);
1044 	if (err)
1045 		return err;
1046 
1047 	return platform_driver_register(&l2_cache_pmu_driver);
1048 }
1049 device_initcall(register_l2_cache_pmu_driver);
1050