treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / arch / arc / kernel / perf_event.c
blob661fd842ea97db7ad4f3871b2a1038d715a44130
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Linux performance counter support for ARC CPUs.
4 // This code is inspired by the perf support of various other architectures.
5 //
6 // Copyright (C) 2013-2018 Synopsys, Inc. (www.synopsys.com)
8 #include <linux/errno.h>
9 #include <linux/interrupt.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/perf_event.h>
13 #include <linux/platform_device.h>
14 #include <asm/arcregs.h>
15 #include <asm/stacktrace.h>
17 /* HW holds 8 symbols + one for null terminator */
18 #define ARCPMU_EVENT_NAME_LEN 9
20 enum arc_pmu_attr_groups {
21 ARCPMU_ATTR_GR_EVENTS,
22 ARCPMU_ATTR_GR_FORMATS,
23 ARCPMU_NR_ATTR_GR
26 struct arc_pmu_raw_event_entry {
27 char name[ARCPMU_EVENT_NAME_LEN];
30 struct arc_pmu {
31 struct pmu pmu;
32 unsigned int irq;
33 int n_counters;
34 int n_events;
35 u64 max_period;
36 int ev_hw_idx[PERF_COUNT_ARC_HW_MAX];
38 struct arc_pmu_raw_event_entry *raw_entry;
39 struct attribute **attrs;
40 struct perf_pmu_events_attr *attr;
41 const struct attribute_group *attr_groups[ARCPMU_NR_ATTR_GR + 1];
44 struct arc_pmu_cpu {
46 * A 1 bit for an index indicates that the counter is being used for
47 * an event. A 0 means that the counter can be used.
49 unsigned long used_mask[BITS_TO_LONGS(ARC_PERF_MAX_COUNTERS)];
52 * The events that are active on the PMU for the given index.
54 struct perf_event *act_counter[ARC_PERF_MAX_COUNTERS];
57 struct arc_callchain_trace {
58 int depth;
59 void *perf_stuff;
62 static int callchain_trace(unsigned int addr, void *data)
64 struct arc_callchain_trace *ctrl = data;
65 struct perf_callchain_entry_ctx *entry = ctrl->perf_stuff;
67 perf_callchain_store(entry, addr);
69 if (ctrl->depth++ < 3)
70 return 0;
72 return -1;
75 void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
76 struct pt_regs *regs)
78 struct arc_callchain_trace ctrl = {
79 .depth = 0,
80 .perf_stuff = entry,
83 arc_unwind_core(NULL, regs, callchain_trace, &ctrl);
86 void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
87 struct pt_regs *regs)
90 * User stack can't be unwound trivially with kernel dwarf unwinder
91 * So for now just record the user PC
93 perf_callchain_store(entry, instruction_pointer(regs));
96 static struct arc_pmu *arc_pmu;
97 static DEFINE_PER_CPU(struct arc_pmu_cpu, arc_pmu_cpu);
99 /* read counter #idx; note that counter# != event# on ARC! */
100 static u64 arc_pmu_read_counter(int idx)
102 u32 tmp;
103 u64 result;
106 * ARC supports making 'snapshots' of the counters, so we don't
107 * need to care about counters wrapping to 0 underneath our feet
109 write_aux_reg(ARC_REG_PCT_INDEX, idx);
110 tmp = read_aux_reg(ARC_REG_PCT_CONTROL);
111 write_aux_reg(ARC_REG_PCT_CONTROL, tmp | ARC_REG_PCT_CONTROL_SN);
112 result = (u64) (read_aux_reg(ARC_REG_PCT_SNAPH)) << 32;
113 result |= read_aux_reg(ARC_REG_PCT_SNAPL);
115 return result;
118 static void arc_perf_event_update(struct perf_event *event,
119 struct hw_perf_event *hwc, int idx)
121 u64 prev_raw_count = local64_read(&hwc->prev_count);
122 u64 new_raw_count = arc_pmu_read_counter(idx);
123 s64 delta = new_raw_count - prev_raw_count;
126 * We aren't afraid of hwc->prev_count changing beneath our feet
127 * because there's no way for us to re-enter this function anytime.
129 local64_set(&hwc->prev_count, new_raw_count);
130 local64_add(delta, &event->count);
131 local64_sub(delta, &hwc->period_left);
134 static void arc_pmu_read(struct perf_event *event)
136 arc_perf_event_update(event, &event->hw, event->hw.idx);
139 static int arc_pmu_cache_event(u64 config)
141 unsigned int cache_type, cache_op, cache_result;
142 int ret;
144 cache_type = (config >> 0) & 0xff;
145 cache_op = (config >> 8) & 0xff;
146 cache_result = (config >> 16) & 0xff;
147 if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
148 return -EINVAL;
149 if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
150 return -EINVAL;
151 if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
152 return -EINVAL;
154 ret = arc_pmu_cache_map[cache_type][cache_op][cache_result];
156 if (ret == CACHE_OP_UNSUPPORTED)
157 return -ENOENT;
159 pr_debug("init cache event: type/op/result %d/%d/%d with h/w %d \'%s\'\n",
160 cache_type, cache_op, cache_result, ret,
161 arc_pmu_ev_hw_map[ret]);
163 return ret;
166 /* initializes hw_perf_event structure if event is supported */
167 static int arc_pmu_event_init(struct perf_event *event)
169 struct hw_perf_event *hwc = &event->hw;
170 int ret;
172 if (!is_sampling_event(event)) {
173 hwc->sample_period = arc_pmu->max_period;
174 hwc->last_period = hwc->sample_period;
175 local64_set(&hwc->period_left, hwc->sample_period);
178 hwc->config = 0;
180 if (is_isa_arcv2()) {
181 /* "exclude user" means "count only kernel" */
182 if (event->attr.exclude_user)
183 hwc->config |= ARC_REG_PCT_CONFIG_KERN;
185 /* "exclude kernel" means "count only user" */
186 if (event->attr.exclude_kernel)
187 hwc->config |= ARC_REG_PCT_CONFIG_USER;
190 switch (event->attr.type) {
191 case PERF_TYPE_HARDWARE:
192 if (event->attr.config >= PERF_COUNT_HW_MAX)
193 return -ENOENT;
194 if (arc_pmu->ev_hw_idx[event->attr.config] < 0)
195 return -ENOENT;
196 hwc->config |= arc_pmu->ev_hw_idx[event->attr.config];
197 pr_debug("init event %d with h/w %08x \'%s\'\n",
198 (int)event->attr.config, (int)hwc->config,
199 arc_pmu_ev_hw_map[event->attr.config]);
200 return 0;
202 case PERF_TYPE_HW_CACHE:
203 ret = arc_pmu_cache_event(event->attr.config);
204 if (ret < 0)
205 return ret;
206 hwc->config |= arc_pmu->ev_hw_idx[ret];
207 pr_debug("init cache event with h/w %08x \'%s\'\n",
208 (int)hwc->config, arc_pmu_ev_hw_map[ret]);
209 return 0;
211 case PERF_TYPE_RAW:
212 if (event->attr.config >= arc_pmu->n_events)
213 return -ENOENT;
215 hwc->config |= event->attr.config;
216 pr_debug("init raw event with idx %lld \'%s\'\n",
217 event->attr.config,
218 arc_pmu->raw_entry[event->attr.config].name);
220 return 0;
222 default:
223 return -ENOENT;
227 /* starts all counters */
228 static void arc_pmu_enable(struct pmu *pmu)
230 u32 tmp;
231 tmp = read_aux_reg(ARC_REG_PCT_CONTROL);
232 write_aux_reg(ARC_REG_PCT_CONTROL, (tmp & 0xffff0000) | 0x1);
235 /* stops all counters */
236 static void arc_pmu_disable(struct pmu *pmu)
238 u32 tmp;
239 tmp = read_aux_reg(ARC_REG_PCT_CONTROL);
240 write_aux_reg(ARC_REG_PCT_CONTROL, (tmp & 0xffff0000) | 0x0);
243 static int arc_pmu_event_set_period(struct perf_event *event)
245 struct hw_perf_event *hwc = &event->hw;
246 s64 left = local64_read(&hwc->period_left);
247 s64 period = hwc->sample_period;
248 int idx = hwc->idx;
249 int overflow = 0;
250 u64 value;
252 if (unlikely(left <= -period)) {
253 /* left underflowed by more than period. */
254 left = period;
255 local64_set(&hwc->period_left, left);
256 hwc->last_period = period;
257 overflow = 1;
258 } else if (unlikely(left <= 0)) {
259 /* left underflowed by less than period. */
260 left += period;
261 local64_set(&hwc->period_left, left);
262 hwc->last_period = period;
263 overflow = 1;
266 if (left > arc_pmu->max_period)
267 left = arc_pmu->max_period;
269 value = arc_pmu->max_period - left;
270 local64_set(&hwc->prev_count, value);
272 /* Select counter */
273 write_aux_reg(ARC_REG_PCT_INDEX, idx);
275 /* Write value */
276 write_aux_reg(ARC_REG_PCT_COUNTL, lower_32_bits(value));
277 write_aux_reg(ARC_REG_PCT_COUNTH, upper_32_bits(value));
279 perf_event_update_userpage(event);
281 return overflow;
285 * Assigns hardware counter to hardware condition.
286 * Note that there is no separate start/stop mechanism;
287 * stopping is achieved by assigning the 'never' condition
289 static void arc_pmu_start(struct perf_event *event, int flags)
291 struct hw_perf_event *hwc = &event->hw;
292 int idx = hwc->idx;
294 if (WARN_ON_ONCE(idx == -1))
295 return;
297 if (flags & PERF_EF_RELOAD)
298 WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
300 hwc->state = 0;
302 arc_pmu_event_set_period(event);
304 /* Enable interrupt for this counter */
305 if (is_sampling_event(event))
306 write_aux_reg(ARC_REG_PCT_INT_CTRL,
307 read_aux_reg(ARC_REG_PCT_INT_CTRL) | BIT(idx));
309 /* enable ARC pmu here */
310 write_aux_reg(ARC_REG_PCT_INDEX, idx); /* counter # */
311 write_aux_reg(ARC_REG_PCT_CONFIG, hwc->config); /* condition */
314 static void arc_pmu_stop(struct perf_event *event, int flags)
316 struct hw_perf_event *hwc = &event->hw;
317 int idx = hwc->idx;
319 /* Disable interrupt for this counter */
320 if (is_sampling_event(event)) {
322 * Reset interrupt flag by writing of 1. This is required
323 * to make sure pending interrupt was not left.
325 write_aux_reg(ARC_REG_PCT_INT_ACT, BIT(idx));
326 write_aux_reg(ARC_REG_PCT_INT_CTRL,
327 read_aux_reg(ARC_REG_PCT_INT_CTRL) & ~BIT(idx));
330 if (!(event->hw.state & PERF_HES_STOPPED)) {
331 /* stop ARC pmu here */
332 write_aux_reg(ARC_REG_PCT_INDEX, idx);
334 /* condition code #0 is always "never" */
335 write_aux_reg(ARC_REG_PCT_CONFIG, 0);
337 event->hw.state |= PERF_HES_STOPPED;
340 if ((flags & PERF_EF_UPDATE) &&
341 !(event->hw.state & PERF_HES_UPTODATE)) {
342 arc_perf_event_update(event, &event->hw, idx);
343 event->hw.state |= PERF_HES_UPTODATE;
347 static void arc_pmu_del(struct perf_event *event, int flags)
349 struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu);
351 arc_pmu_stop(event, PERF_EF_UPDATE);
352 __clear_bit(event->hw.idx, pmu_cpu->used_mask);
354 pmu_cpu->act_counter[event->hw.idx] = 0;
356 perf_event_update_userpage(event);
359 /* allocate hardware counter and optionally start counting */
360 static int arc_pmu_add(struct perf_event *event, int flags)
362 struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu);
363 struct hw_perf_event *hwc = &event->hw;
364 int idx = hwc->idx;
366 idx = ffz(pmu_cpu->used_mask[0]);
367 if (idx == arc_pmu->n_counters)
368 return -EAGAIN;
370 __set_bit(idx, pmu_cpu->used_mask);
371 hwc->idx = idx;
373 write_aux_reg(ARC_REG_PCT_INDEX, idx);
375 pmu_cpu->act_counter[idx] = event;
377 if (is_sampling_event(event)) {
378 /* Mimic full counter overflow as other arches do */
379 write_aux_reg(ARC_REG_PCT_INT_CNTL,
380 lower_32_bits(arc_pmu->max_period));
381 write_aux_reg(ARC_REG_PCT_INT_CNTH,
382 upper_32_bits(arc_pmu->max_period));
385 write_aux_reg(ARC_REG_PCT_CONFIG, 0);
386 write_aux_reg(ARC_REG_PCT_COUNTL, 0);
387 write_aux_reg(ARC_REG_PCT_COUNTH, 0);
388 local64_set(&hwc->prev_count, 0);
390 hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
391 if (flags & PERF_EF_START)
392 arc_pmu_start(event, PERF_EF_RELOAD);
394 perf_event_update_userpage(event);
396 return 0;
399 #ifdef CONFIG_ISA_ARCV2
400 static irqreturn_t arc_pmu_intr(int irq, void *dev)
402 struct perf_sample_data data;
403 struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu);
404 struct pt_regs *regs;
405 unsigned int active_ints;
406 int idx;
408 arc_pmu_disable(&arc_pmu->pmu);
410 active_ints = read_aux_reg(ARC_REG_PCT_INT_ACT);
411 if (!active_ints)
412 goto done;
414 regs = get_irq_regs();
416 do {
417 struct perf_event *event;
418 struct hw_perf_event *hwc;
420 idx = __ffs(active_ints);
422 /* Reset interrupt flag by writing of 1 */
423 write_aux_reg(ARC_REG_PCT_INT_ACT, BIT(idx));
426 * On reset of "interrupt active" bit corresponding
427 * "interrupt enable" bit gets automatically reset as well.
428 * Now we need to re-enable interrupt for the counter.
430 write_aux_reg(ARC_REG_PCT_INT_CTRL,
431 read_aux_reg(ARC_REG_PCT_INT_CTRL) | BIT(idx));
433 event = pmu_cpu->act_counter[idx];
434 hwc = &event->hw;
436 WARN_ON_ONCE(hwc->idx != idx);
438 arc_perf_event_update(event, &event->hw, event->hw.idx);
439 perf_sample_data_init(&data, 0, hwc->last_period);
440 if (arc_pmu_event_set_period(event)) {
441 if (perf_event_overflow(event, &data, regs))
442 arc_pmu_stop(event, 0);
445 active_ints &= ~BIT(idx);
446 } while (active_ints);
448 done:
449 arc_pmu_enable(&arc_pmu->pmu);
451 return IRQ_HANDLED;
453 #else
455 static irqreturn_t arc_pmu_intr(int irq, void *dev)
457 return IRQ_NONE;
460 #endif /* CONFIG_ISA_ARCV2 */
462 static void arc_cpu_pmu_irq_init(void *data)
464 int irq = *(int *)data;
466 enable_percpu_irq(irq, IRQ_TYPE_NONE);
468 /* Clear all pending interrupt flags */
469 write_aux_reg(ARC_REG_PCT_INT_ACT, 0xffffffff);
472 /* Event field occupies the bottom 15 bits of our config field */
473 PMU_FORMAT_ATTR(event, "config:0-14");
474 static struct attribute *arc_pmu_format_attrs[] = {
475 &format_attr_event.attr,
476 NULL,
479 static struct attribute_group arc_pmu_format_attr_gr = {
480 .name = "format",
481 .attrs = arc_pmu_format_attrs,
484 static ssize_t arc_pmu_events_sysfs_show(struct device *dev,
485 struct device_attribute *attr,
486 char *page)
488 struct perf_pmu_events_attr *pmu_attr;
490 pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
491 return sprintf(page, "event=0x%04llx\n", pmu_attr->id);
495 * We don't add attrs here as we don't have pre-defined list of perf events.
496 * We will generate and add attrs dynamically in probe() after we read HW
497 * configuration.
499 static struct attribute_group arc_pmu_events_attr_gr = {
500 .name = "events",
503 static void arc_pmu_add_raw_event_attr(int j, char *str)
505 memmove(arc_pmu->raw_entry[j].name, str, ARCPMU_EVENT_NAME_LEN - 1);
506 arc_pmu->attr[j].attr.attr.name = arc_pmu->raw_entry[j].name;
507 arc_pmu->attr[j].attr.attr.mode = VERIFY_OCTAL_PERMISSIONS(0444);
508 arc_pmu->attr[j].attr.show = arc_pmu_events_sysfs_show;
509 arc_pmu->attr[j].id = j;
510 arc_pmu->attrs[j] = &(arc_pmu->attr[j].attr.attr);
513 static int arc_pmu_raw_alloc(struct device *dev)
515 arc_pmu->attr = devm_kmalloc_array(dev, arc_pmu->n_events + 1,
516 sizeof(*arc_pmu->attr), GFP_KERNEL | __GFP_ZERO);
517 if (!arc_pmu->attr)
518 return -ENOMEM;
520 arc_pmu->attrs = devm_kmalloc_array(dev, arc_pmu->n_events + 1,
521 sizeof(*arc_pmu->attrs), GFP_KERNEL | __GFP_ZERO);
522 if (!arc_pmu->attrs)
523 return -ENOMEM;
525 arc_pmu->raw_entry = devm_kmalloc_array(dev, arc_pmu->n_events,
526 sizeof(*arc_pmu->raw_entry), GFP_KERNEL | __GFP_ZERO);
527 if (!arc_pmu->raw_entry)
528 return -ENOMEM;
530 return 0;
533 static inline bool event_in_hw_event_map(int i, char *name)
535 if (!arc_pmu_ev_hw_map[i])
536 return false;
538 if (!strlen(arc_pmu_ev_hw_map[i]))
539 return false;
541 if (strcmp(arc_pmu_ev_hw_map[i], name))
542 return false;
544 return true;
547 static void arc_pmu_map_hw_event(int j, char *str)
549 int i;
551 /* See if HW condition has been mapped to a perf event_id */
552 for (i = 0; i < ARRAY_SIZE(arc_pmu_ev_hw_map); i++) {
553 if (event_in_hw_event_map(i, str)) {
554 pr_debug("mapping perf event %2d to h/w event \'%8s\' (idx %d)\n",
555 i, str, j);
556 arc_pmu->ev_hw_idx[i] = j;
561 static int arc_pmu_device_probe(struct platform_device *pdev)
563 struct arc_reg_pct_build pct_bcr;
564 struct arc_reg_cc_build cc_bcr;
565 int i, has_interrupts;
566 int counter_size; /* in bits */
568 union cc_name {
569 struct {
570 u32 word0, word1;
571 char sentinel;
572 } indiv;
573 char str[ARCPMU_EVENT_NAME_LEN];
574 } cc_name;
577 READ_BCR(ARC_REG_PCT_BUILD, pct_bcr);
578 if (!pct_bcr.v) {
579 pr_err("This core does not have performance counters!\n");
580 return -ENODEV;
582 BUILD_BUG_ON(ARC_PERF_MAX_COUNTERS > 32);
583 if (WARN_ON(pct_bcr.c > ARC_PERF_MAX_COUNTERS))
584 return -EINVAL;
586 READ_BCR(ARC_REG_CC_BUILD, cc_bcr);
587 if (WARN(!cc_bcr.v, "Counters exist but No countable conditions?"))
588 return -EINVAL;
590 arc_pmu = devm_kzalloc(&pdev->dev, sizeof(struct arc_pmu), GFP_KERNEL);
591 if (!arc_pmu)
592 return -ENOMEM;
594 arc_pmu->n_events = cc_bcr.c;
596 if (arc_pmu_raw_alloc(&pdev->dev))
597 return -ENOMEM;
599 has_interrupts = is_isa_arcv2() ? pct_bcr.i : 0;
601 arc_pmu->n_counters = pct_bcr.c;
602 counter_size = 32 + (pct_bcr.s << 4);
604 arc_pmu->max_period = (1ULL << counter_size) / 2 - 1ULL;
606 pr_info("ARC perf\t: %d counters (%d bits), %d conditions%s\n",
607 arc_pmu->n_counters, counter_size, cc_bcr.c,
608 has_interrupts ? ", [overflow IRQ support]" : "");
610 cc_name.str[ARCPMU_EVENT_NAME_LEN - 1] = 0;
611 for (i = 0; i < PERF_COUNT_ARC_HW_MAX; i++)
612 arc_pmu->ev_hw_idx[i] = -1;
614 /* loop thru all available h/w condition indexes */
615 for (i = 0; i < cc_bcr.c; i++) {
616 write_aux_reg(ARC_REG_CC_INDEX, i);
617 cc_name.indiv.word0 = le32_to_cpu(read_aux_reg(ARC_REG_CC_NAME0));
618 cc_name.indiv.word1 = le32_to_cpu(read_aux_reg(ARC_REG_CC_NAME1));
620 arc_pmu_map_hw_event(i, cc_name.str);
621 arc_pmu_add_raw_event_attr(i, cc_name.str);
624 arc_pmu_events_attr_gr.attrs = arc_pmu->attrs;
625 arc_pmu->attr_groups[ARCPMU_ATTR_GR_EVENTS] = &arc_pmu_events_attr_gr;
626 arc_pmu->attr_groups[ARCPMU_ATTR_GR_FORMATS] = &arc_pmu_format_attr_gr;
628 arc_pmu->pmu = (struct pmu) {
629 .pmu_enable = arc_pmu_enable,
630 .pmu_disable = arc_pmu_disable,
631 .event_init = arc_pmu_event_init,
632 .add = arc_pmu_add,
633 .del = arc_pmu_del,
634 .start = arc_pmu_start,
635 .stop = arc_pmu_stop,
636 .read = arc_pmu_read,
637 .attr_groups = arc_pmu->attr_groups,
640 if (has_interrupts) {
641 int irq = platform_get_irq(pdev, 0);
643 if (irq < 0) {
644 pr_err("Cannot get IRQ number for the platform\n");
645 return -ENODEV;
648 arc_pmu->irq = irq;
650 /* intc map function ensures irq_set_percpu_devid() called */
651 request_percpu_irq(irq, arc_pmu_intr, "ARC perf counters",
652 this_cpu_ptr(&arc_pmu_cpu));
654 on_each_cpu(arc_cpu_pmu_irq_init, &irq, 1);
656 } else
657 arc_pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
660 * perf parser doesn't really like '-' symbol in events name, so let's
661 * use '_' in arc pct name as it goes to kernel PMU event prefix.
663 return perf_pmu_register(&arc_pmu->pmu, "arc_pct", PERF_TYPE_RAW);
666 static const struct of_device_id arc_pmu_match[] = {
667 { .compatible = "snps,arc700-pct" },
668 { .compatible = "snps,archs-pct" },
671 MODULE_DEVICE_TABLE(of, arc_pmu_match);
673 static struct platform_driver arc_pmu_driver = {
674 .driver = {
675 .name = "arc-pct",
676 .of_match_table = of_match_ptr(arc_pmu_match),
678 .probe = arc_pmu_device_probe,
681 module_platform_driver(arc_pmu_driver);
683 MODULE_LICENSE("GPL");
684 MODULE_AUTHOR("Mischa Jonker <mjonker@synopsys.com>");
685 MODULE_DESCRIPTION("ARC PMU driver");