xref: /linux/drivers/perf/qcom_l2_pmu.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /* Copyright (c) 2015-2017 The Linux Foundation. All rights reserved.
2  *
3  * This program is free software; you can redistribute it and/or modify
4  * it under the terms of the GNU General Public License version 2 and
5  * only version 2 as published by the Free Software Foundation.
6  *
7  * This program is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10  * GNU General Public License for more details.
11  */
12 #include <linux/acpi.h>
13 #include <linux/bitops.h>
14 #include <linux/bug.h>
15 #include <linux/cpuhotplug.h>
16 #include <linux/cpumask.h>
17 #include <linux/device.h>
18 #include <linux/errno.h>
19 #include <linux/interrupt.h>
20 #include <linux/irq.h>
21 #include <linux/kernel.h>
22 #include <linux/list.h>
23 #include <linux/percpu.h>
24 #include <linux/perf_event.h>
25 #include <linux/platform_device.h>
26 #include <linux/smp.h>
27 #include <linux/spinlock.h>
28 #include <linux/sysfs.h>
29 #include <linux/types.h>
30 
31 #include <asm/barrier.h>
32 #include <asm/local64.h>
33 #include <asm/sysreg.h>
34 
35 #define MAX_L2_CTRS             9
36 
37 #define L2PMCR_NUM_EV_SHIFT     11
38 #define L2PMCR_NUM_EV_MASK      0x1F
39 
40 #define L2PMCR                  0x400
41 #define L2PMCNTENCLR            0x403
42 #define L2PMCNTENSET            0x404
43 #define L2PMINTENCLR            0x405
44 #define L2PMINTENSET            0x406
45 #define L2PMOVSCLR              0x407
46 #define L2PMOVSSET              0x408
47 #define L2PMCCNTCR              0x409
48 #define L2PMCCNTR               0x40A
49 #define L2PMCCNTSR              0x40C
50 #define L2PMRESR                0x410
51 #define IA_L2PMXEVCNTCR_BASE    0x420
52 #define IA_L2PMXEVCNTR_BASE     0x421
53 #define IA_L2PMXEVFILTER_BASE   0x423
54 #define IA_L2PMXEVTYPER_BASE    0x424
55 
56 #define IA_L2_REG_OFFSET        0x10
57 
58 #define L2PMXEVFILTER_SUFILTER_ALL      0x000E0000
59 #define L2PMXEVFILTER_ORGFILTER_IDINDEP 0x00000004
60 #define L2PMXEVFILTER_ORGFILTER_ALL     0x00000003
61 
62 #define L2EVTYPER_REG_SHIFT     3
63 
64 #define L2PMRESR_GROUP_BITS     8
65 #define L2PMRESR_GROUP_MASK     GENMASK(7, 0)
66 
67 #define L2CYCLE_CTR_BIT         31
68 #define L2CYCLE_CTR_RAW_CODE    0xFE
69 
70 #define L2PMCR_RESET_ALL        0x6
71 #define L2PMCR_COUNTERS_ENABLE  0x1
72 #define L2PMCR_COUNTERS_DISABLE 0x0
73 
74 #define L2PMRESR_EN             BIT_ULL(63)
75 
76 #define L2_EVT_MASK             0x00000FFF
77 #define L2_EVT_CODE_MASK        0x00000FF0
78 #define L2_EVT_GRP_MASK         0x0000000F
79 #define L2_EVT_CODE_SHIFT       4
80 #define L2_EVT_GRP_SHIFT        0
81 
82 #define L2_EVT_CODE(event)   (((event) & L2_EVT_CODE_MASK) >> L2_EVT_CODE_SHIFT)
83 #define L2_EVT_GROUP(event)  (((event) & L2_EVT_GRP_MASK) >> L2_EVT_GRP_SHIFT)
84 
85 #define L2_EVT_GROUP_MAX        7
86 
87 #define L2_COUNTER_RELOAD       BIT_ULL(31)
88 #define L2_CYCLE_COUNTER_RELOAD BIT_ULL(63)
89 
90 #define L2CPUSRSELR_EL1         sys_reg(3, 3, 15, 0, 6)
91 #define L2CPUSRDR_EL1           sys_reg(3, 3, 15, 0, 7)
92 
93 #define reg_idx(reg, i)         (((i) * IA_L2_REG_OFFSET) + reg##_BASE)
94 
95 static DEFINE_RAW_SPINLOCK(l2_access_lock);
96 
97 /**
98  * set_l2_indirect_reg: write value to an L2 register
99  * @reg: Address of L2 register.
100  * @value: Value to be written to register.
101  *
102  * Use architecturally required barriers for ordering between system register
103  * accesses
104  */
105 static void set_l2_indirect_reg(u64 reg, u64 val)
106 {
107 	unsigned long flags;
108 
109 	raw_spin_lock_irqsave(&l2_access_lock, flags);
110 	write_sysreg_s(reg, L2CPUSRSELR_EL1);
111 	isb();
112 	write_sysreg_s(val, L2CPUSRDR_EL1);
113 	isb();
114 	raw_spin_unlock_irqrestore(&l2_access_lock, flags);
115 }
116 
117 /**
118  * get_l2_indirect_reg: read an L2 register value
119  * @reg: Address of L2 register.
120  *
121  * Use architecturally required barriers for ordering between system register
122  * accesses
123  */
124 static u64 get_l2_indirect_reg(u64 reg)
125 {
126 	u64 val;
127 	unsigned long flags;
128 
129 	raw_spin_lock_irqsave(&l2_access_lock, flags);
130 	write_sysreg_s(reg, L2CPUSRSELR_EL1);
131 	isb();
132 	val = read_sysreg_s(L2CPUSRDR_EL1);
133 	raw_spin_unlock_irqrestore(&l2_access_lock, flags);
134 
135 	return val;
136 }
137 
138 struct cluster_pmu;
139 
140 /*
141  * Aggregate PMU. Implements the core pmu functions and manages
142  * the hardware PMUs.
143  */
144 struct l2cache_pmu {
145 	struct hlist_node node;
146 	u32 num_pmus;
147 	struct pmu pmu;
148 	int num_counters;
149 	cpumask_t cpumask;
150 	struct platform_device *pdev;
151 	struct cluster_pmu * __percpu *pmu_cluster;
152 	struct list_head clusters;
153 };
154 
155 /*
156  * The cache is made up of one or more clusters, each cluster has its own PMU.
157  * Each cluster is associated with one or more CPUs.
158  * This structure represents one of the hardware PMUs.
159  *
160  * Events can be envisioned as a 2-dimensional array. Each column represents
161  * a group of events. There are 8 groups. Only one entry from each
162  * group can be in use at a time.
163  *
164  * Events are specified as 0xCCG, where CC is 2 hex digits specifying
165  * the code (array row) and G specifies the group (column).
166  *
167  * In addition there is a cycle counter event specified by L2CYCLE_CTR_RAW_CODE
168  * which is outside the above scheme.
169  */
170 struct cluster_pmu {
171 	struct list_head next;
172 	struct perf_event *events[MAX_L2_CTRS];
173 	struct l2cache_pmu *l2cache_pmu;
174 	DECLARE_BITMAP(used_counters, MAX_L2_CTRS);
175 	DECLARE_BITMAP(used_groups, L2_EVT_GROUP_MAX + 1);
176 	int irq;
177 	int cluster_id;
178 	/* The CPU that is used for collecting events on this cluster */
179 	int on_cpu;
180 	/* All the CPUs associated with this cluster */
181 	cpumask_t cluster_cpus;
182 	spinlock_t pmu_lock;
183 };
184 
185 #define to_l2cache_pmu(p) (container_of(p, struct l2cache_pmu, pmu))
186 
187 static u32 l2_cycle_ctr_idx;
188 static u32 l2_counter_present_mask;
189 
190 static inline u32 idx_to_reg_bit(u32 idx)
191 {
192 	if (idx == l2_cycle_ctr_idx)
193 		return BIT(L2CYCLE_CTR_BIT);
194 
195 	return BIT(idx);
196 }
197 
198 static inline struct cluster_pmu *get_cluster_pmu(
199 	struct l2cache_pmu *l2cache_pmu, int cpu)
200 {
201 	return *per_cpu_ptr(l2cache_pmu->pmu_cluster, cpu);
202 }
203 
204 static void cluster_pmu_reset(void)
205 {
206 	/* Reset all counters */
207 	set_l2_indirect_reg(L2PMCR, L2PMCR_RESET_ALL);
208 	set_l2_indirect_reg(L2PMCNTENCLR, l2_counter_present_mask);
209 	set_l2_indirect_reg(L2PMINTENCLR, l2_counter_present_mask);
210 	set_l2_indirect_reg(L2PMOVSCLR, l2_counter_present_mask);
211 }
212 
213 static inline void cluster_pmu_enable(void)
214 {
215 	set_l2_indirect_reg(L2PMCR, L2PMCR_COUNTERS_ENABLE);
216 }
217 
218 static inline void cluster_pmu_disable(void)
219 {
220 	set_l2_indirect_reg(L2PMCR, L2PMCR_COUNTERS_DISABLE);
221 }
222 
223 static inline void cluster_pmu_counter_set_value(u32 idx, u64 value)
224 {
225 	if (idx == l2_cycle_ctr_idx)
226 		set_l2_indirect_reg(L2PMCCNTR, value);
227 	else
228 		set_l2_indirect_reg(reg_idx(IA_L2PMXEVCNTR, idx), value);
229 }
230 
231 static inline u64 cluster_pmu_counter_get_value(u32 idx)
232 {
233 	u64 value;
234 
235 	if (idx == l2_cycle_ctr_idx)
236 		value = get_l2_indirect_reg(L2PMCCNTR);
237 	else
238 		value = get_l2_indirect_reg(reg_idx(IA_L2PMXEVCNTR, idx));
239 
240 	return value;
241 }
242 
243 static inline void cluster_pmu_counter_enable(u32 idx)
244 {
245 	set_l2_indirect_reg(L2PMCNTENSET, idx_to_reg_bit(idx));
246 }
247 
248 static inline void cluster_pmu_counter_disable(u32 idx)
249 {
250 	set_l2_indirect_reg(L2PMCNTENCLR, idx_to_reg_bit(idx));
251 }
252 
253 static inline void cluster_pmu_counter_enable_interrupt(u32 idx)
254 {
255 	set_l2_indirect_reg(L2PMINTENSET, idx_to_reg_bit(idx));
256 }
257 
258 static inline void cluster_pmu_counter_disable_interrupt(u32 idx)
259 {
260 	set_l2_indirect_reg(L2PMINTENCLR, idx_to_reg_bit(idx));
261 }
262 
263 static inline void cluster_pmu_set_evccntcr(u32 val)
264 {
265 	set_l2_indirect_reg(L2PMCCNTCR, val);
266 }
267 
268 static inline void cluster_pmu_set_evcntcr(u32 ctr, u32 val)
269 {
270 	set_l2_indirect_reg(reg_idx(IA_L2PMXEVCNTCR, ctr), val);
271 }
272 
273 static inline void cluster_pmu_set_evtyper(u32 ctr, u32 val)
274 {
275 	set_l2_indirect_reg(reg_idx(IA_L2PMXEVTYPER, ctr), val);
276 }
277 
278 static void cluster_pmu_set_resr(struct cluster_pmu *cluster,
279 			       u32 event_group, u32 event_cc)
280 {
281 	u64 field;
282 	u64 resr_val;
283 	u32 shift;
284 	unsigned long flags;
285 
286 	shift = L2PMRESR_GROUP_BITS * event_group;
287 	field = ((u64)(event_cc & L2PMRESR_GROUP_MASK) << shift);
288 
289 	spin_lock_irqsave(&cluster->pmu_lock, flags);
290 
291 	resr_val = get_l2_indirect_reg(L2PMRESR);
292 	resr_val &= ~(L2PMRESR_GROUP_MASK << shift);
293 	resr_val |= field;
294 	resr_val |= L2PMRESR_EN;
295 	set_l2_indirect_reg(L2PMRESR, resr_val);
296 
297 	spin_unlock_irqrestore(&cluster->pmu_lock, flags);
298 }
299 
300 /*
301  * Hardware allows filtering of events based on the originating
302  * CPU. Turn this off by setting filter bits to allow events from
303  * all CPUS, subunits and ID independent events in this cluster.
304  */
305 static inline void cluster_pmu_set_evfilter_sys_mode(u32 ctr)
306 {
307 	u32 val =  L2PMXEVFILTER_SUFILTER_ALL |
308 		   L2PMXEVFILTER_ORGFILTER_IDINDEP |
309 		   L2PMXEVFILTER_ORGFILTER_ALL;
310 
311 	set_l2_indirect_reg(reg_idx(IA_L2PMXEVFILTER, ctr), val);
312 }
313 
314 static inline u32 cluster_pmu_getreset_ovsr(void)
315 {
316 	u32 result = get_l2_indirect_reg(L2PMOVSSET);
317 
318 	set_l2_indirect_reg(L2PMOVSCLR, result);
319 	return result;
320 }
321 
322 static inline bool cluster_pmu_has_overflowed(u32 ovsr)
323 {
324 	return !!(ovsr & l2_counter_present_mask);
325 }
326 
327 static inline bool cluster_pmu_counter_has_overflowed(u32 ovsr, u32 idx)
328 {
329 	return !!(ovsr & idx_to_reg_bit(idx));
330 }
331 
332 static void l2_cache_event_update(struct perf_event *event)
333 {
334 	struct hw_perf_event *hwc = &event->hw;
335 	u64 delta, prev, now;
336 	u32 idx = hwc->idx;
337 
338 	do {
339 		prev = local64_read(&hwc->prev_count);
340 		now = cluster_pmu_counter_get_value(idx);
341 	} while (local64_cmpxchg(&hwc->prev_count, prev, now) != prev);
342 
343 	/*
344 	 * The cycle counter is 64-bit, but all other counters are
345 	 * 32-bit, and we must handle 32-bit overflow explicitly.
346 	 */
347 	delta = now - prev;
348 	if (idx != l2_cycle_ctr_idx)
349 		delta &= 0xffffffff;
350 
351 	local64_add(delta, &event->count);
352 }
353 
354 static void l2_cache_cluster_set_period(struct cluster_pmu *cluster,
355 				       struct hw_perf_event *hwc)
356 {
357 	u32 idx = hwc->idx;
358 	u64 new;
359 
360 	/*
361 	 * We limit the max period to half the max counter value so
362 	 * that even in the case of extreme interrupt latency the
363 	 * counter will (hopefully) not wrap past its initial value.
364 	 */
365 	if (idx == l2_cycle_ctr_idx)
366 		new = L2_CYCLE_COUNTER_RELOAD;
367 	else
368 		new = L2_COUNTER_RELOAD;
369 
370 	local64_set(&hwc->prev_count, new);
371 	cluster_pmu_counter_set_value(idx, new);
372 }
373 
374 static int l2_cache_get_event_idx(struct cluster_pmu *cluster,
375 				   struct perf_event *event)
376 {
377 	struct hw_perf_event *hwc = &event->hw;
378 	int idx;
379 	int num_ctrs = cluster->l2cache_pmu->num_counters - 1;
380 	unsigned int group;
381 
382 	if (hwc->config_base == L2CYCLE_CTR_RAW_CODE) {
383 		if (test_and_set_bit(l2_cycle_ctr_idx, cluster->used_counters))
384 			return -EAGAIN;
385 
386 		return l2_cycle_ctr_idx;
387 	}
388 
389 	idx = find_first_zero_bit(cluster->used_counters, num_ctrs);
390 	if (idx == num_ctrs)
391 		/* The counters are all in use. */
392 		return -EAGAIN;
393 
394 	/*
395 	 * Check for column exclusion: event column already in use by another
396 	 * event. This is for events which are not in the same group.
397 	 * Conflicting events in the same group are detected in event_init.
398 	 */
399 	group = L2_EVT_GROUP(hwc->config_base);
400 	if (test_bit(group, cluster->used_groups))
401 		return -EAGAIN;
402 
403 	set_bit(idx, cluster->used_counters);
404 	set_bit(group, cluster->used_groups);
405 
406 	return idx;
407 }
408 
409 static void l2_cache_clear_event_idx(struct cluster_pmu *cluster,
410 				      struct perf_event *event)
411 {
412 	struct hw_perf_event *hwc = &event->hw;
413 	int idx = hwc->idx;
414 
415 	clear_bit(idx, cluster->used_counters);
416 	if (hwc->config_base != L2CYCLE_CTR_RAW_CODE)
417 		clear_bit(L2_EVT_GROUP(hwc->config_base), cluster->used_groups);
418 }
419 
420 static irqreturn_t l2_cache_handle_irq(int irq_num, void *data)
421 {
422 	struct cluster_pmu *cluster = data;
423 	int num_counters = cluster->l2cache_pmu->num_counters;
424 	u32 ovsr;
425 	int idx;
426 
427 	ovsr = cluster_pmu_getreset_ovsr();
428 	if (!cluster_pmu_has_overflowed(ovsr))
429 		return IRQ_NONE;
430 
431 	for_each_set_bit(idx, cluster->used_counters, num_counters) {
432 		struct perf_event *event = cluster->events[idx];
433 		struct hw_perf_event *hwc;
434 
435 		if (WARN_ON_ONCE(!event))
436 			continue;
437 
438 		if (!cluster_pmu_counter_has_overflowed(ovsr, idx))
439 			continue;
440 
441 		l2_cache_event_update(event);
442 		hwc = &event->hw;
443 
444 		l2_cache_cluster_set_period(cluster, hwc);
445 	}
446 
447 	return IRQ_HANDLED;
448 }
449 
450 /*
451  * Implementation of abstract pmu functionality required by
452  * the core perf events code.
453  */
454 
455 static void l2_cache_pmu_enable(struct pmu *pmu)
456 {
457 	/*
458 	 * Although there is only one PMU (per socket) controlling multiple
459 	 * physical PMUs (per cluster), because we do not support per-task mode
460 	 * each event is associated with a CPU. Each event has pmu_enable
461 	 * called on its CPU, so here it is only necessary to enable the
462 	 * counters for the current CPU.
463 	 */
464 
465 	cluster_pmu_enable();
466 }
467 
468 static void l2_cache_pmu_disable(struct pmu *pmu)
469 {
470 	cluster_pmu_disable();
471 }
472 
473 static int l2_cache_event_init(struct perf_event *event)
474 {
475 	struct hw_perf_event *hwc = &event->hw;
476 	struct cluster_pmu *cluster;
477 	struct perf_event *sibling;
478 	struct l2cache_pmu *l2cache_pmu;
479 
480 	if (event->attr.type != event->pmu->type)
481 		return -ENOENT;
482 
483 	l2cache_pmu = to_l2cache_pmu(event->pmu);
484 
485 	if (hwc->sample_period) {
486 		dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
487 				    "Sampling not supported\n");
488 		return -EOPNOTSUPP;
489 	}
490 
491 	if (event->cpu < 0) {
492 		dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
493 				    "Per-task mode not supported\n");
494 		return -EOPNOTSUPP;
495 	}
496 
497 	/* We cannot filter accurately so we just don't allow it. */
498 	if (event->attr.exclude_user || event->attr.exclude_kernel ||
499 	    event->attr.exclude_hv || event->attr.exclude_idle) {
500 		dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
501 				    "Can't exclude execution levels\n");
502 		return -EOPNOTSUPP;
503 	}
504 
505 	if (((L2_EVT_GROUP(event->attr.config) > L2_EVT_GROUP_MAX) ||
506 	     ((event->attr.config & ~L2_EVT_MASK) != 0)) &&
507 	    (event->attr.config != L2CYCLE_CTR_RAW_CODE)) {
508 		dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
509 				    "Invalid config %llx\n",
510 				    event->attr.config);
511 		return -EINVAL;
512 	}
513 
514 	/* Don't allow groups with mixed PMUs, except for s/w events */
515 	if (event->group_leader->pmu != event->pmu &&
516 	    !is_software_event(event->group_leader)) {
517 		dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
518 			 "Can't create mixed PMU group\n");
519 		return -EINVAL;
520 	}
521 
522 	list_for_each_entry(sibling, &event->group_leader->sibling_list,
523 			    group_entry)
524 		if (sibling->pmu != event->pmu &&
525 		    !is_software_event(sibling)) {
526 			dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
527 				 "Can't create mixed PMU group\n");
528 			return -EINVAL;
529 		}
530 
531 	cluster = get_cluster_pmu(l2cache_pmu, event->cpu);
532 	if (!cluster) {
533 		/* CPU has not been initialised */
534 		dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
535 			"CPU%d not associated with L2 cluster\n", event->cpu);
536 		return -EINVAL;
537 	}
538 
539 	/* Ensure all events in a group are on the same cpu */
540 	if ((event->group_leader != event) &&
541 	    (cluster->on_cpu != event->group_leader->cpu)) {
542 		dev_dbg_ratelimited(&l2cache_pmu->pdev->dev,
543 			 "Can't create group on CPUs %d and %d",
544 			 event->cpu, event->group_leader->cpu);
545 		return -EINVAL;
546 	}
547 
548 	if ((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 	list_for_each_entry(sibling, &event->group_leader->sibling_list,
559 			    group_entry) {
560 		if ((sibling != event) &&
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 static struct attribute *l2_cache_pmu_formats[] = {
702 	&format_attr_l2_code.attr,
703 	&format_attr_l2_group.attr,
704 	NULL,
705 };
706 
707 static struct attribute_group l2_cache_pmu_format_group = {
708 	.name = "format",
709 	.attrs = l2_cache_pmu_formats,
710 };
711 
712 static const struct attribute_group *l2_cache_pmu_attr_grps[] = {
713 	&l2_cache_pmu_format_group,
714 	&l2_cache_pmu_cpumask_group,
715 	NULL,
716 };
717 
718 /*
719  * Generic device handlers
720  */
721 
722 static const struct acpi_device_id l2_cache_pmu_acpi_match[] = {
723 	{ "QCOM8130", },
724 	{ }
725 };
726 
727 static int get_num_counters(void)
728 {
729 	int val;
730 
731 	val = get_l2_indirect_reg(L2PMCR);
732 
733 	/*
734 	 * Read number of counters from L2PMCR and add 1
735 	 * for the cycle counter.
736 	 */
737 	return ((val >> L2PMCR_NUM_EV_SHIFT) & L2PMCR_NUM_EV_MASK) + 1;
738 }
739 
740 static struct cluster_pmu *l2_cache_associate_cpu_with_cluster(
741 	struct l2cache_pmu *l2cache_pmu, int cpu)
742 {
743 	u64 mpidr;
744 	int cpu_cluster_id;
745 	struct cluster_pmu *cluster = NULL;
746 
747 	/*
748 	 * This assumes that the cluster_id is in MPIDR[aff1] for
749 	 * single-threaded cores, and MPIDR[aff2] for multi-threaded
750 	 * cores. This logic will have to be updated if this changes.
751 	 */
752 	mpidr = read_cpuid_mpidr();
753 	if (mpidr & MPIDR_MT_BITMASK)
754 		cpu_cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 2);
755 	else
756 		cpu_cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 1);
757 
758 	list_for_each_entry(cluster, &l2cache_pmu->clusters, next) {
759 		if (cluster->cluster_id != cpu_cluster_id)
760 			continue;
761 
762 		dev_info(&l2cache_pmu->pdev->dev,
763 			 "CPU%d associated with cluster %d\n", cpu,
764 			 cluster->cluster_id);
765 		cpumask_set_cpu(cpu, &cluster->cluster_cpus);
766 		*per_cpu_ptr(l2cache_pmu->pmu_cluster, cpu) = cluster;
767 		break;
768 	}
769 
770 	return cluster;
771 }
772 
773 static int l2cache_pmu_online_cpu(unsigned int cpu, struct hlist_node *node)
774 {
775 	struct cluster_pmu *cluster;
776 	struct l2cache_pmu *l2cache_pmu;
777 
778 	l2cache_pmu = hlist_entry_safe(node, struct l2cache_pmu, node);
779 	cluster = get_cluster_pmu(l2cache_pmu, cpu);
780 	if (!cluster) {
781 		/* First time this CPU has come online */
782 		cluster = l2_cache_associate_cpu_with_cluster(l2cache_pmu, cpu);
783 		if (!cluster) {
784 			/* Only if broken firmware doesn't list every cluster */
785 			WARN_ONCE(1, "No L2 cache cluster for CPU%d\n", cpu);
786 			return 0;
787 		}
788 	}
789 
790 	/* If another CPU is managing this cluster, we're done */
791 	if (cluster->on_cpu != -1)
792 		return 0;
793 
794 	/*
795 	 * All CPUs on this cluster were down, use this one.
796 	 * Reset to put it into sane state.
797 	 */
798 	cluster->on_cpu = cpu;
799 	cpumask_set_cpu(cpu, &l2cache_pmu->cpumask);
800 	cluster_pmu_reset();
801 
802 	WARN_ON(irq_set_affinity(cluster->irq, cpumask_of(cpu)));
803 	enable_irq(cluster->irq);
804 
805 	return 0;
806 }
807 
808 static int l2cache_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
809 {
810 	struct cluster_pmu *cluster;
811 	struct l2cache_pmu *l2cache_pmu;
812 	cpumask_t cluster_online_cpus;
813 	unsigned int target;
814 
815 	l2cache_pmu = hlist_entry_safe(node, struct l2cache_pmu, node);
816 	cluster = get_cluster_pmu(l2cache_pmu, cpu);
817 	if (!cluster)
818 		return 0;
819 
820 	/* If this CPU is not managing the cluster, we're done */
821 	if (cluster->on_cpu != cpu)
822 		return 0;
823 
824 	/* Give up ownership of cluster */
825 	cpumask_clear_cpu(cpu, &l2cache_pmu->cpumask);
826 	cluster->on_cpu = -1;
827 
828 	/* Any other CPU for this cluster which is still online */
829 	cpumask_and(&cluster_online_cpus, &cluster->cluster_cpus,
830 		    cpu_online_mask);
831 	target = cpumask_any_but(&cluster_online_cpus, cpu);
832 	if (target >= nr_cpu_ids) {
833 		disable_irq(cluster->irq);
834 		return 0;
835 	}
836 
837 	perf_pmu_migrate_context(&l2cache_pmu->pmu, cpu, target);
838 	cluster->on_cpu = target;
839 	cpumask_set_cpu(target, &l2cache_pmu->cpumask);
840 	WARN_ON(irq_set_affinity(cluster->irq, cpumask_of(target)));
841 
842 	return 0;
843 }
844 
845 static int l2_cache_pmu_probe_cluster(struct device *dev, void *data)
846 {
847 	struct platform_device *pdev = to_platform_device(dev->parent);
848 	struct platform_device *sdev = to_platform_device(dev);
849 	struct l2cache_pmu *l2cache_pmu = data;
850 	struct cluster_pmu *cluster;
851 	struct acpi_device *device;
852 	unsigned long fw_cluster_id;
853 	int err;
854 	int irq;
855 
856 	if (acpi_bus_get_device(ACPI_HANDLE(dev), &device))
857 		return -ENODEV;
858 
859 	if (kstrtoul(device->pnp.unique_id, 10, &fw_cluster_id) < 0) {
860 		dev_err(&pdev->dev, "unable to read ACPI uid\n");
861 		return -ENODEV;
862 	}
863 
864 	cluster = devm_kzalloc(&pdev->dev, sizeof(*cluster), GFP_KERNEL);
865 	if (!cluster)
866 		return -ENOMEM;
867 
868 	INIT_LIST_HEAD(&cluster->next);
869 	list_add(&cluster->next, &l2cache_pmu->clusters);
870 	cluster->cluster_id = fw_cluster_id;
871 
872 	irq = platform_get_irq(sdev, 0);
873 	if (irq < 0) {
874 		dev_err(&pdev->dev,
875 			"Failed to get valid irq for cluster %ld\n",
876 			fw_cluster_id);
877 		return irq;
878 	}
879 	irq_set_status_flags(irq, IRQ_NOAUTOEN);
880 	cluster->irq = irq;
881 
882 	cluster->l2cache_pmu = l2cache_pmu;
883 	cluster->on_cpu = -1;
884 
885 	err = devm_request_irq(&pdev->dev, irq, l2_cache_handle_irq,
886 			       IRQF_NOBALANCING | IRQF_NO_THREAD,
887 			       "l2-cache-pmu", cluster);
888 	if (err) {
889 		dev_err(&pdev->dev,
890 			"Unable to request IRQ%d for L2 PMU counters\n", irq);
891 		return err;
892 	}
893 
894 	dev_info(&pdev->dev,
895 		"Registered L2 cache PMU cluster %ld\n", fw_cluster_id);
896 
897 	spin_lock_init(&cluster->pmu_lock);
898 
899 	l2cache_pmu->num_pmus++;
900 
901 	return 0;
902 }
903 
904 static int l2_cache_pmu_probe(struct platform_device *pdev)
905 {
906 	int err;
907 	struct l2cache_pmu *l2cache_pmu;
908 
909 	l2cache_pmu =
910 		devm_kzalloc(&pdev->dev, sizeof(*l2cache_pmu), GFP_KERNEL);
911 	if (!l2cache_pmu)
912 		return -ENOMEM;
913 
914 	INIT_LIST_HEAD(&l2cache_pmu->clusters);
915 
916 	platform_set_drvdata(pdev, l2cache_pmu);
917 	l2cache_pmu->pmu = (struct pmu) {
918 		/* suffix is instance id for future use with multiple sockets */
919 		.name		= "l2cache_0",
920 		.task_ctx_nr    = perf_invalid_context,
921 		.pmu_enable	= l2_cache_pmu_enable,
922 		.pmu_disable	= l2_cache_pmu_disable,
923 		.event_init	= l2_cache_event_init,
924 		.add		= l2_cache_event_add,
925 		.del		= l2_cache_event_del,
926 		.start		= l2_cache_event_start,
927 		.stop		= l2_cache_event_stop,
928 		.read		= l2_cache_event_read,
929 		.attr_groups	= l2_cache_pmu_attr_grps,
930 	};
931 
932 	l2cache_pmu->num_counters = get_num_counters();
933 	l2cache_pmu->pdev = pdev;
934 	l2cache_pmu->pmu_cluster = devm_alloc_percpu(&pdev->dev,
935 						     struct cluster_pmu *);
936 	if (!l2cache_pmu->pmu_cluster)
937 		return -ENOMEM;
938 
939 	l2_cycle_ctr_idx = l2cache_pmu->num_counters - 1;
940 	l2_counter_present_mask = GENMASK(l2cache_pmu->num_counters - 2, 0) |
941 		BIT(L2CYCLE_CTR_BIT);
942 
943 	cpumask_clear(&l2cache_pmu->cpumask);
944 
945 	/* Read cluster info and initialize each cluster */
946 	err = device_for_each_child(&pdev->dev, l2cache_pmu,
947 				    l2_cache_pmu_probe_cluster);
948 	if (err)
949 		return err;
950 
951 	if (l2cache_pmu->num_pmus == 0) {
952 		dev_err(&pdev->dev, "No hardware L2 cache PMUs found\n");
953 		return -ENODEV;
954 	}
955 
956 	err = cpuhp_state_add_instance(CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
957 				       &l2cache_pmu->node);
958 	if (err) {
959 		dev_err(&pdev->dev, "Error %d registering hotplug", err);
960 		return err;
961 	}
962 
963 	err = perf_pmu_register(&l2cache_pmu->pmu, l2cache_pmu->pmu.name, -1);
964 	if (err) {
965 		dev_err(&pdev->dev, "Error %d registering L2 cache PMU\n", err);
966 		goto out_unregister;
967 	}
968 
969 	dev_info(&pdev->dev, "Registered L2 cache PMU using %d HW PMUs\n",
970 		 l2cache_pmu->num_pmus);
971 
972 	return err;
973 
974 out_unregister:
975 	cpuhp_state_remove_instance(CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
976 				    &l2cache_pmu->node);
977 	return err;
978 }
979 
980 static int l2_cache_pmu_remove(struct platform_device *pdev)
981 {
982 	struct l2cache_pmu *l2cache_pmu =
983 		to_l2cache_pmu(platform_get_drvdata(pdev));
984 
985 	perf_pmu_unregister(&l2cache_pmu->pmu);
986 	cpuhp_state_remove_instance(CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
987 				    &l2cache_pmu->node);
988 	return 0;
989 }
990 
991 static struct platform_driver l2_cache_pmu_driver = {
992 	.driver = {
993 		.name = "qcom-l2cache-pmu",
994 		.acpi_match_table = ACPI_PTR(l2_cache_pmu_acpi_match),
995 	},
996 	.probe = l2_cache_pmu_probe,
997 	.remove = l2_cache_pmu_remove,
998 };
999 
1000 static int __init register_l2_cache_pmu_driver(void)
1001 {
1002 	int err;
1003 
1004 	err = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
1005 				      "AP_PERF_ARM_QCOM_L2_ONLINE",
1006 				      l2cache_pmu_online_cpu,
1007 				      l2cache_pmu_offline_cpu);
1008 	if (err)
1009 		return err;
1010 
1011 	return platform_driver_register(&l2_cache_pmu_driver);
1012 }
1013 device_initcall(register_l2_cache_pmu_driver);
1014