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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
60const char *perf_pmu_name(void)
61{
62 if (!sh_pmu)
63 return NULL;
64
65 return sh_pmu->name;
66}
67EXPORT_SYMBOL_GPL(perf_pmu_name);
68
69int perf_num_counters(void)
70{
71 if (!sh_pmu)
72 return 0;
73
74 return sh_pmu->num_events;
75}
76EXPORT_SYMBOL_GPL(perf_num_counters);
77
78/*
79 * Release the PMU if this is the last perf_event.
80 */
81static void hw_perf_event_destroy(struct perf_event *event)
82{
83 if (!atomic_add_unless(&num_events, -1, 1)) {
84 mutex_lock(&pmc_reserve_mutex);
85 if (atomic_dec_return(&num_events) == 0)
86 release_pmc_hardware();
87 mutex_unlock(&pmc_reserve_mutex);
88 }
89}
90
91static int hw_perf_cache_event(int config, int *evp)
92{
93 unsigned long type, op, result;
94 int ev;
95
96 if (!sh_pmu->cache_events)
97 return -EINVAL;
98
99 /* unpack config */
100 type = config & 0xff;
101 op = (config >> 8) & 0xff;
102 result = (config >> 16) & 0xff;
103
104 if (type >= PERF_COUNT_HW_CACHE_MAX ||
105 op >= PERF_COUNT_HW_CACHE_OP_MAX ||
106 result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
107 return -EINVAL;
108
109 ev = (*sh_pmu->cache_events)[type][op][result];
110 if (ev == 0)
111 return -EOPNOTSUPP;
112 if (ev == -1)
113 return -EINVAL;
114 *evp = ev;
115 return 0;
116}
117
118static int __hw_perf_event_init(struct perf_event *event)
119{
120 struct perf_event_attr *attr = &event->attr;
121 struct hw_perf_event *hwc = &event->hw;
122 int config = -1;
123 int err;
124
125 if (!sh_pmu_initialized())
126 return -ENODEV;
127
128 /*
129 * See if we need to reserve the counter.
130 *
131 * If no events are currently in use, then we have to take a
132 * mutex to ensure that we don't race with another task doing
133 * reserve_pmc_hardware or release_pmc_hardware.
134 */
135 err = 0;
136 if (!atomic_inc_not_zero(&num_events)) {
137 mutex_lock(&pmc_reserve_mutex);
138 if (atomic_read(&num_events) == 0 &&
139 reserve_pmc_hardware())
140 err = -EBUSY;
141 else
142 atomic_inc(&num_events);
143 mutex_unlock(&pmc_reserve_mutex);
144 }
145
146 if (err)
147 return err;
148
149 event->destroy = hw_perf_event_destroy;
150
151 switch (attr->type) {
152 case PERF_TYPE_RAW:
153 config = attr->config & sh_pmu->raw_event_mask;
154 break;
155 case PERF_TYPE_HW_CACHE:
156 err = hw_perf_cache_event(attr->config, &config);
157 if (err)
158 return err;
159 break;
160 case PERF_TYPE_HARDWARE:
161 if (attr->config >= sh_pmu->max_events)
162 return -EINVAL;
163
164 config = sh_pmu->event_map(attr->config);
165 break;
166 }
167
168 if (config == -1)
169 return -EINVAL;
170
171 hwc->config |= config;
172
173 return 0;
174}
175
176static void sh_perf_event_update(struct perf_event *event,
177 struct hw_perf_event *hwc, int idx)
178{
179 u64 prev_raw_count, new_raw_count;
180 s64 delta;
181 int shift = 0;
182
183 /*
184 * Depending on the counter configuration, they may or may not
185 * be chained, in which case the previous counter value can be
186 * updated underneath us if the lower-half overflows.
187 *
188 * Our tactic to handle this is to first atomically read and
189 * exchange a new raw count - then add that new-prev delta
190 * count to the generic counter atomically.
191 *
192 * As there is no interrupt associated with the overflow events,
193 * this is the simplest approach for maintaining consistency.
194 */
195again:
196 prev_raw_count = local64_read(&hwc->prev_count);
197 new_raw_count = sh_pmu->read(idx);
198
199 if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
200 new_raw_count) != prev_raw_count)
201 goto again;
202
203 /*
204 * Now we have the new raw value and have updated the prev
205 * timestamp already. We can now calculate the elapsed delta
206 * (counter-)time and add that to the generic counter.
207 *
208 * Careful, not all hw sign-extends above the physical width
209 * of the count.
210 */
211 delta = (new_raw_count << shift) - (prev_raw_count << shift);
212 delta >>= shift;
213
214 local64_add(delta, &event->count);
215}
216
217static void sh_pmu_stop(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 (!(event->hw.state & PERF_HES_STOPPED)) {
224 sh_pmu->disable(hwc, idx);
225 cpuc->events[idx] = NULL;
226 event->hw.state |= PERF_HES_STOPPED;
227 }
228
229 if ((flags & PERF_EF_UPDATE) && !(event->hw.state & PERF_HES_UPTODATE)) {
230 sh_perf_event_update(event, &event->hw, idx);
231 event->hw.state |= PERF_HES_UPTODATE;
232 }
233}
234
235static void sh_pmu_start(struct perf_event *event, int flags)
236{
237 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
238 struct hw_perf_event *hwc = &event->hw;
239 int idx = hwc->idx;
240
241 if (WARN_ON_ONCE(idx == -1))
242 return;
243
244 if (flags & PERF_EF_RELOAD)
245 WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
246
247 cpuc->events[idx] = event;
248 event->hw.state = 0;
249 sh_pmu->enable(hwc, idx);
250}
251
252static void sh_pmu_del(struct perf_event *event, int flags)
253{
254 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
255
256 sh_pmu_stop(event, PERF_EF_UPDATE);
257 __clear_bit(event->hw.idx, cpuc->used_mask);
258
259 perf_event_update_userpage(event);
260}
261
262static int sh_pmu_add(struct perf_event *event, int flags)
263{
264 struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
265 struct hw_perf_event *hwc = &event->hw;
266 int idx = hwc->idx;
267 int ret = -EAGAIN;
268
269 perf_pmu_disable(event->pmu);
270
271 if (__test_and_set_bit(idx, cpuc->used_mask)) {
272 idx = find_first_zero_bit(cpuc->used_mask, sh_pmu->num_events);
273 if (idx == sh_pmu->num_events)
274 goto out;
275
276 __set_bit(idx, cpuc->used_mask);
277 hwc->idx = idx;
278 }
279
280 sh_pmu->disable(hwc, idx);
281
282 event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
283 if (flags & PERF_EF_START)
284 sh_pmu_start(event, PERF_EF_RELOAD);
285
286 perf_event_update_userpage(event);
287 ret = 0;
288out:
289 perf_pmu_enable(event->pmu);
290 return ret;
291}
292
293static void sh_pmu_read(struct perf_event *event)
294{
295 sh_perf_event_update(event, &event->hw, event->hw.idx);
296}
297
298static int sh_pmu_event_init(struct perf_event *event)
299{
300 int err;
301
302 /* does not support taken branch sampling */
303 if (has_branch_stack(event))
304 return -EOPNOTSUPP;
305
306 switch (event->attr.type) {
307 case PERF_TYPE_RAW:
308 case PERF_TYPE_HW_CACHE:
309 case PERF_TYPE_HARDWARE:
310 err = __hw_perf_event_init(event);
311 break;
312
313 default:
314 return -ENOENT;
315 }
316
317 if (unlikely(err)) {
318 if (event->destroy)
319 event->destroy(event);
320 }
321
322 return err;
323}
324
325static void sh_pmu_enable(struct pmu *pmu)
326{
327 if (!sh_pmu_initialized())
328 return;
329
330 sh_pmu->enable_all();
331}
332
333static void sh_pmu_disable(struct pmu *pmu)
334{
335 if (!sh_pmu_initialized())
336 return;
337
338 sh_pmu->disable_all();
339}
340
341static struct pmu pmu = {
342 .pmu_enable = sh_pmu_enable,
343 .pmu_disable = sh_pmu_disable,
344 .event_init = sh_pmu_event_init,
345 .add = sh_pmu_add,
346 .del = sh_pmu_del,
347 .start = sh_pmu_start,
348 .stop = sh_pmu_stop,
349 .read = sh_pmu_read,
350};
351
352static int sh_pmu_prepare_cpu(unsigned int cpu)
353{
354 struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu);
355
356 memset(cpuhw, 0, sizeof(struct cpu_hw_events));
357 return 0;
358}
359
360int register_sh_pmu(struct sh_pmu *_pmu)
361{
362 if (sh_pmu)
363 return -EBUSY;
364 sh_pmu = _pmu;
365
366 pr_info("Performance Events: %s support registered\n", _pmu->name);
367
368 /*
369 * All of the on-chip counters are "limited", in that they have
370 * no interrupts, and are therefore unable to do sampling without
371 * further work and timer assistance.
372 */
373 pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
374
375 WARN_ON(_pmu->num_events > MAX_HWEVENTS);
376
377 perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
378 cpuhp_setup_state(CPUHP_PERF_SUPERH, "PERF_SUPERH", sh_pmu_prepare_cpu,
379 NULL);
380 return 0;
381}
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}