Loading...
1/*
2 * Performance event support framework for SuperH hardware counters.
3 *
4 * Copyright (C) 2009 Paul Mundt
5 *
6 * Heavily based on the x86 and PowerPC implementations.
7 *
8 * x86:
9 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
10 * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
11 * Copyright (C) 2009 Jaswinder Singh Rajput
12 * Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter
13 * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra
14 * Copyright (C) 2009 Intel Corporation, <markus.t.metzger@intel.com>
15 *
16 * ppc:
17 * Copyright 2008-2009 Paul Mackerras, IBM Corporation.
18 *
19 * This file is subject to the terms and conditions of the GNU General Public
20 * License. See the file "COPYING" in the main directory of this archive
21 * for more details.
22 */
23#include <linux/kernel.h>
24#include <linux/init.h>
25#include <linux/io.h>
26#include <linux/irq.h>
27#include <linux/perf_event.h>
28#include <linux/export.h>
29#include <asm/processor.h>
30
31struct cpu_hw_events {
32 struct perf_event *events[MAX_HWEVENTS];
33 unsigned long used_mask[BITS_TO_LONGS(MAX_HWEVENTS)];
34 unsigned long active_mask[BITS_TO_LONGS(MAX_HWEVENTS)];
35};
36
37DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events);
38
39static struct sh_pmu *sh_pmu __read_mostly;
40
41/* Number of perf_events counting hardware events */
42static atomic_t num_events;
43/* Used to avoid races in calling reserve/release_pmc_hardware */
44static DEFINE_MUTEX(pmc_reserve_mutex);
45
46/*
47 * Stub these out for now, do something more profound later.
48 */
49int reserve_pmc_hardware(void)
50{
51 return 0;
52}
53
54void release_pmc_hardware(void)
55{
56}
57
58static inline int sh_pmu_initialized(void)
59{
60 return !!sh_pmu;
61}
62
63const char *perf_pmu_name(void)
64{
65 if (!sh_pmu)
66 return NULL;
67
68 return sh_pmu->name;
69}
70EXPORT_SYMBOL_GPL(perf_pmu_name);
71
72int perf_num_counters(void)
73{
74 if (!sh_pmu)
75 return 0;
76
77 return sh_pmu->num_events;
78}
79EXPORT_SYMBOL_GPL(perf_num_counters);
80
81/*
82 * Release the PMU if this is the last perf_event.
83 */
84static void hw_perf_event_destroy(struct perf_event *event)
85{
86 if (!atomic_add_unless(&num_events, -1, 1)) {
87 mutex_lock(&pmc_reserve_mutex);
88 if (atomic_dec_return(&num_events) == 0)
89 release_pmc_hardware();
90 mutex_unlock(&pmc_reserve_mutex);
91 }
92}
93
94static int hw_perf_cache_event(int config, int *evp)
95{
96 unsigned long type, op, result;
97 int ev;
98
99 if (!sh_pmu->cache_events)
100 return -EINVAL;
101
102 /* unpack config */
103 type = config & 0xff;
104 op = (config >> 8) & 0xff;
105 result = (config >> 16) & 0xff;
106
107 if (type >= PERF_COUNT_HW_CACHE_MAX ||
108 op >= PERF_COUNT_HW_CACHE_OP_MAX ||
109 result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
110 return -EINVAL;
111
112 ev = (*sh_pmu->cache_events)[type][op][result];
113 if (ev == 0)
114 return -EOPNOTSUPP;
115 if (ev == -1)
116 return -EINVAL;
117 *evp = ev;
118 return 0;
119}
120
121static int __hw_perf_event_init(struct perf_event *event)
122{
123 struct perf_event_attr *attr = &event->attr;
124 struct hw_perf_event *hwc = &event->hw;
125 int config = -1;
126 int err;
127
128 if (!sh_pmu_initialized())
129 return -ENODEV;
130
131 /*
132 * See if we need to reserve the counter.
133 *
134 * If no events are currently in use, then we have to take a
135 * mutex to ensure that we don't race with another task doing
136 * reserve_pmc_hardware or release_pmc_hardware.
137 */
138 err = 0;
139 if (!atomic_inc_not_zero(&num_events)) {
140 mutex_lock(&pmc_reserve_mutex);
141 if (atomic_read(&num_events) == 0 &&
142 reserve_pmc_hardware())
143 err = -EBUSY;
144 else
145 atomic_inc(&num_events);
146 mutex_unlock(&pmc_reserve_mutex);
147 }
148
149 if (err)
150 return err;
151
152 event->destroy = hw_perf_event_destroy;
153
154 switch (attr->type) {
155 case PERF_TYPE_RAW:
156 config = attr->config & sh_pmu->raw_event_mask;
157 break;
158 case PERF_TYPE_HW_CACHE:
159 err = hw_perf_cache_event(attr->config, &config);
160 if (err)
161 return err;
162 break;
163 case PERF_TYPE_HARDWARE:
164 if (attr->config >= sh_pmu->max_events)
165 return -EINVAL;
166
167 config = sh_pmu->event_map(attr->config);
168 break;
169 }
170
171 if (config == -1)
172 return -EINVAL;
173
174 hwc->config |= config;
175
176 return 0;
177}
178
179static void sh_perf_event_update(struct perf_event *event,
180 struct hw_perf_event *hwc, int idx)
181{
182 u64 prev_raw_count, new_raw_count;
183 s64 delta;
184 int shift = 0;
185
186 /*
187 * Depending on the counter configuration, they may or may not
188 * be chained, in which case the previous counter value can be
189 * updated underneath us if the lower-half overflows.
190 *
191 * Our tactic to handle this is to first atomically read and
192 * exchange a new raw count - then add that new-prev delta
193 * count to the generic counter atomically.
194 *
195 * As there is no interrupt associated with the overflow events,
196 * this is the simplest approach for maintaining consistency.
197 */
198again:
199 prev_raw_count = local64_read(&hwc->prev_count);
200 new_raw_count = sh_pmu->read(idx);
201
202 if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
203 new_raw_count) != prev_raw_count)
204 goto again;
205
206 /*
207 * Now we have the new raw value and have updated the prev
208 * timestamp already. We can now calculate the elapsed delta
209 * (counter-)time and add that to the generic counter.
210 *
211 * Careful, not all hw sign-extends above the physical width
212 * of the count.
213 */
214 delta = (new_raw_count << shift) - (prev_raw_count << shift);
215 delta >>= shift;
216
217 local64_add(delta, &event->count);
218}
219
220static void sh_pmu_stop(struct perf_event *event, int flags)
221{
222 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
223 struct hw_perf_event *hwc = &event->hw;
224 int idx = hwc->idx;
225
226 if (!(event->hw.state & PERF_HES_STOPPED)) {
227 sh_pmu->disable(hwc, idx);
228 cpuc->events[idx] = NULL;
229 event->hw.state |= PERF_HES_STOPPED;
230 }
231
232 if ((flags & PERF_EF_UPDATE) && !(event->hw.state & PERF_HES_UPTODATE)) {
233 sh_perf_event_update(event, &event->hw, idx);
234 event->hw.state |= PERF_HES_UPTODATE;
235 }
236}
237
238static void sh_pmu_start(struct perf_event *event, int flags)
239{
240 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
241 struct hw_perf_event *hwc = &event->hw;
242 int idx = hwc->idx;
243
244 if (WARN_ON_ONCE(idx == -1))
245 return;
246
247 if (flags & PERF_EF_RELOAD)
248 WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
249
250 cpuc->events[idx] = event;
251 event->hw.state = 0;
252 sh_pmu->enable(hwc, idx);
253}
254
255static void sh_pmu_del(struct perf_event *event, int flags)
256{
257 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
258
259 sh_pmu_stop(event, PERF_EF_UPDATE);
260 __clear_bit(event->hw.idx, cpuc->used_mask);
261
262 perf_event_update_userpage(event);
263}
264
265static int sh_pmu_add(struct perf_event *event, int flags)
266{
267 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
268 struct hw_perf_event *hwc = &event->hw;
269 int idx = hwc->idx;
270 int ret = -EAGAIN;
271
272 perf_pmu_disable(event->pmu);
273
274 if (__test_and_set_bit(idx, cpuc->used_mask)) {
275 idx = find_first_zero_bit(cpuc->used_mask, sh_pmu->num_events);
276 if (idx == sh_pmu->num_events)
277 goto out;
278
279 __set_bit(idx, cpuc->used_mask);
280 hwc->idx = idx;
281 }
282
283 sh_pmu->disable(hwc, idx);
284
285 event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
286 if (flags & PERF_EF_START)
287 sh_pmu_start(event, PERF_EF_RELOAD);
288
289 perf_event_update_userpage(event);
290 ret = 0;
291out:
292 perf_pmu_enable(event->pmu);
293 return ret;
294}
295
296static void sh_pmu_read(struct perf_event *event)
297{
298 sh_perf_event_update(event, &event->hw, event->hw.idx);
299}
300
301static int sh_pmu_event_init(struct perf_event *event)
302{
303 int err;
304
305 /* does not support taken branch sampling */
306 if (has_branch_stack(event))
307 return -EOPNOTSUPP;
308
309 switch (event->attr.type) {
310 case PERF_TYPE_RAW:
311 case PERF_TYPE_HW_CACHE:
312 case PERF_TYPE_HARDWARE:
313 err = __hw_perf_event_init(event);
314 break;
315
316 default:
317 return -ENOENT;
318 }
319
320 if (unlikely(err)) {
321 if (event->destroy)
322 event->destroy(event);
323 }
324
325 return err;
326}
327
328static void sh_pmu_enable(struct pmu *pmu)
329{
330 if (!sh_pmu_initialized())
331 return;
332
333 sh_pmu->enable_all();
334}
335
336static void sh_pmu_disable(struct pmu *pmu)
337{
338 if (!sh_pmu_initialized())
339 return;
340
341 sh_pmu->disable_all();
342}
343
344static struct pmu pmu = {
345 .pmu_enable = sh_pmu_enable,
346 .pmu_disable = sh_pmu_disable,
347 .event_init = sh_pmu_event_init,
348 .add = sh_pmu_add,
349 .del = sh_pmu_del,
350 .start = sh_pmu_start,
351 .stop = sh_pmu_stop,
352 .read = sh_pmu_read,
353};
354
355static void sh_pmu_setup(int cpu)
356{
357 struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu);
358
359 memset(cpuhw, 0, sizeof(struct cpu_hw_events));
360}
361
362static int
363sh_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu)
364{
365 unsigned int cpu = (long)hcpu;
366
367 switch (action & ~CPU_TASKS_FROZEN) {
368 case CPU_UP_PREPARE:
369 sh_pmu_setup(cpu);
370 break;
371
372 default:
373 break;
374 }
375
376 return NOTIFY_OK;
377}
378
379int register_sh_pmu(struct sh_pmu *_pmu)
380{
381 if (sh_pmu)
382 return -EBUSY;
383 sh_pmu = _pmu;
384
385 pr_info("Performance Events: %s support registered\n", _pmu->name);
386
387 /*
388 * All of the on-chip counters are "limited", in that they have
389 * no interrupts, and are therefore unable to do sampling without
390 * further work and timer assistance.
391 */
392 pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
393
394 WARN_ON(_pmu->num_events > MAX_HWEVENTS);
395
396 perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
397 perf_cpu_notifier(sh_pmu_notifier);
398 return 0;
399}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Performance event support framework for SuperH hardware counters.
4 *
5 * Copyright (C) 2009 Paul Mundt
6 *
7 * Heavily based on the x86 and PowerPC implementations.
8 *
9 * x86:
10 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
11 * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
12 * Copyright (C) 2009 Jaswinder Singh Rajput
13 * Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter
14 * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra
15 * Copyright (C) 2009 Intel Corporation, <markus.t.metzger@intel.com>
16 *
17 * ppc:
18 * Copyright 2008-2009 Paul Mackerras, IBM Corporation.
19 */
20#include <linux/kernel.h>
21#include <linux/init.h>
22#include <linux/io.h>
23#include <linux/irq.h>
24#include <linux/perf_event.h>
25#include <linux/export.h>
26#include <asm/processor.h>
27
28struct cpu_hw_events {
29 struct perf_event *events[MAX_HWEVENTS];
30 unsigned long used_mask[BITS_TO_LONGS(MAX_HWEVENTS)];
31 unsigned long active_mask[BITS_TO_LONGS(MAX_HWEVENTS)];
32};
33
34DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events);
35
36static struct sh_pmu *sh_pmu __read_mostly;
37
38/* Number of perf_events counting hardware events */
39static atomic_t num_events;
40/* Used to avoid races in calling reserve/release_pmc_hardware */
41static DEFINE_MUTEX(pmc_reserve_mutex);
42
43/*
44 * Stub these out for now, do something more profound later.
45 */
46int reserve_pmc_hardware(void)
47{
48 return 0;
49}
50
51void release_pmc_hardware(void)
52{
53}
54
55static inline int sh_pmu_initialized(void)
56{
57 return !!sh_pmu;
58}
59
60/*
61 * Release the PMU if this is the last perf_event.
62 */
63static void hw_perf_event_destroy(struct perf_event *event)
64{
65 if (!atomic_add_unless(&num_events, -1, 1)) {
66 mutex_lock(&pmc_reserve_mutex);
67 if (atomic_dec_return(&num_events) == 0)
68 release_pmc_hardware();
69 mutex_unlock(&pmc_reserve_mutex);
70 }
71}
72
73static int hw_perf_cache_event(int config, int *evp)
74{
75 unsigned long type, op, result;
76 int ev;
77
78 if (!sh_pmu->cache_events)
79 return -EINVAL;
80
81 /* unpack config */
82 type = config & 0xff;
83 op = (config >> 8) & 0xff;
84 result = (config >> 16) & 0xff;
85
86 if (type >= PERF_COUNT_HW_CACHE_MAX ||
87 op >= PERF_COUNT_HW_CACHE_OP_MAX ||
88 result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
89 return -EINVAL;
90
91 ev = (*sh_pmu->cache_events)[type][op][result];
92 if (ev == 0)
93 return -EOPNOTSUPP;
94 if (ev == -1)
95 return -EINVAL;
96 *evp = ev;
97 return 0;
98}
99
100static int __hw_perf_event_init(struct perf_event *event)
101{
102 struct perf_event_attr *attr = &event->attr;
103 struct hw_perf_event *hwc = &event->hw;
104 int config = -1;
105 int err;
106
107 if (!sh_pmu_initialized())
108 return -ENODEV;
109
110 /*
111 * See if we need to reserve the counter.
112 *
113 * If no events are currently in use, then we have to take a
114 * mutex to ensure that we don't race with another task doing
115 * reserve_pmc_hardware or release_pmc_hardware.
116 */
117 err = 0;
118 if (!atomic_inc_not_zero(&num_events)) {
119 mutex_lock(&pmc_reserve_mutex);
120 if (atomic_read(&num_events) == 0 &&
121 reserve_pmc_hardware())
122 err = -EBUSY;
123 else
124 atomic_inc(&num_events);
125 mutex_unlock(&pmc_reserve_mutex);
126 }
127
128 if (err)
129 return err;
130
131 event->destroy = hw_perf_event_destroy;
132
133 switch (attr->type) {
134 case PERF_TYPE_RAW:
135 config = attr->config & sh_pmu->raw_event_mask;
136 break;
137 case PERF_TYPE_HW_CACHE:
138 err = hw_perf_cache_event(attr->config, &config);
139 if (err)
140 return err;
141 break;
142 case PERF_TYPE_HARDWARE:
143 if (attr->config >= sh_pmu->max_events)
144 return -EINVAL;
145
146 config = sh_pmu->event_map(attr->config);
147 break;
148 }
149
150 if (config == -1)
151 return -EINVAL;
152
153 hwc->config |= config;
154
155 return 0;
156}
157
158static void sh_perf_event_update(struct perf_event *event,
159 struct hw_perf_event *hwc, int idx)
160{
161 u64 prev_raw_count, new_raw_count;
162 s64 delta;
163 int shift = 0;
164
165 /*
166 * Depending on the counter configuration, they may or may not
167 * be chained, in which case the previous counter value can be
168 * updated underneath us if the lower-half overflows.
169 *
170 * Our tactic to handle this is to first atomically read and
171 * exchange a new raw count - then add that new-prev delta
172 * count to the generic counter atomically.
173 *
174 * As there is no interrupt associated with the overflow events,
175 * this is the simplest approach for maintaining consistency.
176 */
177again:
178 prev_raw_count = local64_read(&hwc->prev_count);
179 new_raw_count = sh_pmu->read(idx);
180
181 if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
182 new_raw_count) != prev_raw_count)
183 goto again;
184
185 /*
186 * Now we have the new raw value and have updated the prev
187 * timestamp already. We can now calculate the elapsed delta
188 * (counter-)time and add that to the generic counter.
189 *
190 * Careful, not all hw sign-extends above the physical width
191 * of the count.
192 */
193 delta = (new_raw_count << shift) - (prev_raw_count << shift);
194 delta >>= shift;
195
196 local64_add(delta, &event->count);
197}
198
199static void sh_pmu_stop(struct perf_event *event, int flags)
200{
201 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
202 struct hw_perf_event *hwc = &event->hw;
203 int idx = hwc->idx;
204
205 if (!(event->hw.state & PERF_HES_STOPPED)) {
206 sh_pmu->disable(hwc, idx);
207 cpuc->events[idx] = NULL;
208 event->hw.state |= PERF_HES_STOPPED;
209 }
210
211 if ((flags & PERF_EF_UPDATE) && !(event->hw.state & PERF_HES_UPTODATE)) {
212 sh_perf_event_update(event, &event->hw, idx);
213 event->hw.state |= PERF_HES_UPTODATE;
214 }
215}
216
217static void sh_pmu_start(struct perf_event *event, int flags)
218{
219 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
220 struct hw_perf_event *hwc = &event->hw;
221 int idx = hwc->idx;
222
223 if (WARN_ON_ONCE(idx == -1))
224 return;
225
226 if (flags & PERF_EF_RELOAD)
227 WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
228
229 cpuc->events[idx] = event;
230 event->hw.state = 0;
231 sh_pmu->enable(hwc, idx);
232}
233
234static void sh_pmu_del(struct perf_event *event, int flags)
235{
236 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
237
238 sh_pmu_stop(event, PERF_EF_UPDATE);
239 __clear_bit(event->hw.idx, cpuc->used_mask);
240
241 perf_event_update_userpage(event);
242}
243
244static int sh_pmu_add(struct perf_event *event, int flags)
245{
246 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
247 struct hw_perf_event *hwc = &event->hw;
248 int idx = hwc->idx;
249 int ret = -EAGAIN;
250
251 perf_pmu_disable(event->pmu);
252
253 if (__test_and_set_bit(idx, cpuc->used_mask)) {
254 idx = find_first_zero_bit(cpuc->used_mask, sh_pmu->num_events);
255 if (idx == sh_pmu->num_events)
256 goto out;
257
258 __set_bit(idx, cpuc->used_mask);
259 hwc->idx = idx;
260 }
261
262 sh_pmu->disable(hwc, idx);
263
264 event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
265 if (flags & PERF_EF_START)
266 sh_pmu_start(event, PERF_EF_RELOAD);
267
268 perf_event_update_userpage(event);
269 ret = 0;
270out:
271 perf_pmu_enable(event->pmu);
272 return ret;
273}
274
275static void sh_pmu_read(struct perf_event *event)
276{
277 sh_perf_event_update(event, &event->hw, event->hw.idx);
278}
279
280static int sh_pmu_event_init(struct perf_event *event)
281{
282 int err;
283
284 /* does not support taken branch sampling */
285 if (has_branch_stack(event))
286 return -EOPNOTSUPP;
287
288 switch (event->attr.type) {
289 case PERF_TYPE_RAW:
290 case PERF_TYPE_HW_CACHE:
291 case PERF_TYPE_HARDWARE:
292 err = __hw_perf_event_init(event);
293 break;
294
295 default:
296 return -ENOENT;
297 }
298
299 if (unlikely(err)) {
300 if (event->destroy)
301 event->destroy(event);
302 }
303
304 return err;
305}
306
307static void sh_pmu_enable(struct pmu *pmu)
308{
309 if (!sh_pmu_initialized())
310 return;
311
312 sh_pmu->enable_all();
313}
314
315static void sh_pmu_disable(struct pmu *pmu)
316{
317 if (!sh_pmu_initialized())
318 return;
319
320 sh_pmu->disable_all();
321}
322
323static struct pmu pmu = {
324 .pmu_enable = sh_pmu_enable,
325 .pmu_disable = sh_pmu_disable,
326 .event_init = sh_pmu_event_init,
327 .add = sh_pmu_add,
328 .del = sh_pmu_del,
329 .start = sh_pmu_start,
330 .stop = sh_pmu_stop,
331 .read = sh_pmu_read,
332};
333
334static int sh_pmu_prepare_cpu(unsigned int cpu)
335{
336 struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu);
337
338 memset(cpuhw, 0, sizeof(struct cpu_hw_events));
339 return 0;
340}
341
342int register_sh_pmu(struct sh_pmu *_pmu)
343{
344 if (sh_pmu)
345 return -EBUSY;
346 sh_pmu = _pmu;
347
348 pr_info("Performance Events: %s support registered\n", _pmu->name);
349
350 /*
351 * All of the on-chip counters are "limited", in that they have
352 * no interrupts, and are therefore unable to do sampling without
353 * further work and timer assistance.
354 */
355 pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
356
357 WARN_ON(_pmu->num_events > MAX_HWEVENTS);
358
359 perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
360 cpuhp_setup_state(CPUHP_PERF_SUPERH, "PERF_SUPERH", sh_pmu_prepare_cpu,
361 NULL);
362 return 0;
363}