1 /*
2  * HiSilicon SoC Hardware event counters support
3  *
4  * Copyright (C) 2017 Hisilicon Limited
5  * Author: Anurup M <anurup.m@huawei.com>
6  *         Shaokun Zhang <zhangshaokun@hisilicon.com>
7  *
8  * This code is based on the uncore PMUs like arm-cci and arm-ccn.
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  */
14 #include <linux/bitmap.h>
15 #include <linux/bitops.h>
16 #include <linux/bug.h>
17 #include <linux/err.h>
18 #include <linux/errno.h>
19 #include <linux/interrupt.h>
20 
21 #include <asm/local64.h>
22 
23 #include "hisi_uncore_pmu.h"
24 
25 #define HISI_GET_EVENTID(ev) (ev->hw.config_base & 0xff)
26 #define HISI_MAX_PERIOD(nr) (BIT_ULL(nr) - 1)
27 
28 /*
29  * PMU format attributes
30  */
31 ssize_t hisi_format_sysfs_show(struct device *dev,
32 			       struct device_attribute *attr, char *buf)
33 {
34 	struct dev_ext_attribute *eattr;
35 
36 	eattr = container_of(attr, struct dev_ext_attribute, attr);
37 
38 	return sprintf(buf, "%s\n", (char *)eattr->var);
39 }
40 
41 /*
42  * PMU event attributes
43  */
44 ssize_t hisi_event_sysfs_show(struct device *dev,
45 			      struct device_attribute *attr, char *page)
46 {
47 	struct dev_ext_attribute *eattr;
48 
49 	eattr = container_of(attr, struct dev_ext_attribute, attr);
50 
51 	return sprintf(page, "config=0x%lx\n", (unsigned long)eattr->var);
52 }
53 
54 /*
55  * sysfs cpumask attributes. For uncore PMU, we only have a single CPU to show
56  */
57 ssize_t hisi_cpumask_sysfs_show(struct device *dev,
58 				struct device_attribute *attr, char *buf)
59 {
60 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(dev_get_drvdata(dev));
61 
62 	return sprintf(buf, "%d\n", hisi_pmu->on_cpu);
63 }
64 
65 static bool hisi_validate_event_group(struct perf_event *event)
66 {
67 	struct perf_event *sibling, *leader = event->group_leader;
68 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
69 	/* Include count for the event */
70 	int counters = 1;
71 
72 	if (!is_software_event(leader)) {
73 		/*
74 		 * We must NOT create groups containing mixed PMUs, although
75 		 * software events are acceptable
76 		 */
77 		if (leader->pmu != event->pmu)
78 			return false;
79 
80 		/* Increment counter for the leader */
81 		if (leader != event)
82 			counters++;
83 	}
84 
85 	for_each_sibling_event(sibling, event->group_leader) {
86 		if (is_software_event(sibling))
87 			continue;
88 		if (sibling->pmu != event->pmu)
89 			return false;
90 		/* Increment counter for each sibling */
91 		counters++;
92 	}
93 
94 	/* The group can not count events more than the counters in the HW */
95 	return counters <= hisi_pmu->num_counters;
96 }
97 
98 int hisi_uncore_pmu_counter_valid(struct hisi_pmu *hisi_pmu, int idx)
99 {
100 	return idx >= 0 && idx < hisi_pmu->num_counters;
101 }
102 
103 int hisi_uncore_pmu_get_event_idx(struct perf_event *event)
104 {
105 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
106 	unsigned long *used_mask = hisi_pmu->pmu_events.used_mask;
107 	u32 num_counters = hisi_pmu->num_counters;
108 	int idx;
109 
110 	idx = find_first_zero_bit(used_mask, num_counters);
111 	if (idx == num_counters)
112 		return -EAGAIN;
113 
114 	set_bit(idx, used_mask);
115 
116 	return idx;
117 }
118 
119 static void hisi_uncore_pmu_clear_event_idx(struct hisi_pmu *hisi_pmu, int idx)
120 {
121 	if (!hisi_uncore_pmu_counter_valid(hisi_pmu, idx)) {
122 		dev_err(hisi_pmu->dev, "Unsupported event index:%d!\n", idx);
123 		return;
124 	}
125 
126 	clear_bit(idx, hisi_pmu->pmu_events.used_mask);
127 }
128 
129 int hisi_uncore_pmu_event_init(struct perf_event *event)
130 {
131 	struct hw_perf_event *hwc = &event->hw;
132 	struct hisi_pmu *hisi_pmu;
133 
134 	if (event->attr.type != event->pmu->type)
135 		return -ENOENT;
136 
137 	/*
138 	 * We do not support sampling as the counters are all
139 	 * shared by all CPU cores in a CPU die(SCCL). Also we
140 	 * do not support attach to a task(per-process mode)
141 	 */
142 	if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
143 		return -EOPNOTSUPP;
144 
145 	/* counters do not have these bits */
146 	if (event->attr.exclude_user	||
147 	    event->attr.exclude_kernel	||
148 	    event->attr.exclude_host	||
149 	    event->attr.exclude_guest	||
150 	    event->attr.exclude_hv	||
151 	    event->attr.exclude_idle)
152 		return -EINVAL;
153 
154 	/*
155 	 *  The uncore counters not specific to any CPU, so cannot
156 	 *  support per-task
157 	 */
158 	if (event->cpu < 0)
159 		return -EINVAL;
160 
161 	/*
162 	 * Validate if the events in group does not exceed the
163 	 * available counters in hardware.
164 	 */
165 	if (!hisi_validate_event_group(event))
166 		return -EINVAL;
167 
168 	hisi_pmu = to_hisi_pmu(event->pmu);
169 	if (event->attr.config > hisi_pmu->check_event)
170 		return -EINVAL;
171 
172 	if (hisi_pmu->on_cpu == -1)
173 		return -EINVAL;
174 	/*
175 	 * We don't assign an index until we actually place the event onto
176 	 * hardware. Use -1 to signify that we haven't decided where to put it
177 	 * yet.
178 	 */
179 	hwc->idx		= -1;
180 	hwc->config_base	= event->attr.config;
181 
182 	/* Enforce to use the same CPU for all events in this PMU */
183 	event->cpu = hisi_pmu->on_cpu;
184 
185 	return 0;
186 }
187 
188 /*
189  * Set the counter to count the event that we're interested in,
190  * and enable interrupt and counter.
191  */
192 static void hisi_uncore_pmu_enable_event(struct perf_event *event)
193 {
194 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
195 	struct hw_perf_event *hwc = &event->hw;
196 
197 	hisi_pmu->ops->write_evtype(hisi_pmu, hwc->idx,
198 				    HISI_GET_EVENTID(event));
199 
200 	hisi_pmu->ops->enable_counter_int(hisi_pmu, hwc);
201 	hisi_pmu->ops->enable_counter(hisi_pmu, hwc);
202 }
203 
204 /*
205  * Disable counter and interrupt.
206  */
207 static void hisi_uncore_pmu_disable_event(struct perf_event *event)
208 {
209 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
210 	struct hw_perf_event *hwc = &event->hw;
211 
212 	hisi_pmu->ops->disable_counter(hisi_pmu, hwc);
213 	hisi_pmu->ops->disable_counter_int(hisi_pmu, hwc);
214 }
215 
216 void hisi_uncore_pmu_set_event_period(struct perf_event *event)
217 {
218 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
219 	struct hw_perf_event *hwc = &event->hw;
220 
221 	/*
222 	 * The HiSilicon PMU counters support 32 bits or 48 bits, depending on
223 	 * the PMU. We reduce it to 2^(counter_bits - 1) to account for the
224 	 * extreme interrupt latency. So we could hopefully handle the overflow
225 	 * interrupt before another 2^(counter_bits - 1) events occur and the
226 	 * counter overtakes its previous value.
227 	 */
228 	u64 val = BIT_ULL(hisi_pmu->counter_bits - 1);
229 
230 	local64_set(&hwc->prev_count, val);
231 	/* Write start value to the hardware event counter */
232 	hisi_pmu->ops->write_counter(hisi_pmu, hwc, val);
233 }
234 
235 void hisi_uncore_pmu_event_update(struct perf_event *event)
236 {
237 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
238 	struct hw_perf_event *hwc = &event->hw;
239 	u64 delta, prev_raw_count, new_raw_count;
240 
241 	do {
242 		/* Read the count from the counter register */
243 		new_raw_count = hisi_pmu->ops->read_counter(hisi_pmu, hwc);
244 		prev_raw_count = local64_read(&hwc->prev_count);
245 	} while (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
246 				 new_raw_count) != prev_raw_count);
247 	/*
248 	 * compute the delta
249 	 */
250 	delta = (new_raw_count - prev_raw_count) &
251 		HISI_MAX_PERIOD(hisi_pmu->counter_bits);
252 	local64_add(delta, &event->count);
253 }
254 
255 void hisi_uncore_pmu_start(struct perf_event *event, int flags)
256 {
257 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
258 	struct hw_perf_event *hwc = &event->hw;
259 
260 	if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
261 		return;
262 
263 	WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
264 	hwc->state = 0;
265 	hisi_uncore_pmu_set_event_period(event);
266 
267 	if (flags & PERF_EF_RELOAD) {
268 		u64 prev_raw_count =  local64_read(&hwc->prev_count);
269 
270 		hisi_pmu->ops->write_counter(hisi_pmu, hwc, prev_raw_count);
271 	}
272 
273 	hisi_uncore_pmu_enable_event(event);
274 	perf_event_update_userpage(event);
275 }
276 
277 void hisi_uncore_pmu_stop(struct perf_event *event, int flags)
278 {
279 	struct hw_perf_event *hwc = &event->hw;
280 
281 	hisi_uncore_pmu_disable_event(event);
282 	WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
283 	hwc->state |= PERF_HES_STOPPED;
284 
285 	if (hwc->state & PERF_HES_UPTODATE)
286 		return;
287 
288 	/* Read hardware counter and update the perf counter statistics */
289 	hisi_uncore_pmu_event_update(event);
290 	hwc->state |= PERF_HES_UPTODATE;
291 }
292 
293 int hisi_uncore_pmu_add(struct perf_event *event, int flags)
294 {
295 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
296 	struct hw_perf_event *hwc = &event->hw;
297 	int idx;
298 
299 	hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
300 
301 	/* Get an available counter index for counting */
302 	idx = hisi_pmu->ops->get_event_idx(event);
303 	if (idx < 0)
304 		return idx;
305 
306 	event->hw.idx = idx;
307 	hisi_pmu->pmu_events.hw_events[idx] = event;
308 
309 	if (flags & PERF_EF_START)
310 		hisi_uncore_pmu_start(event, PERF_EF_RELOAD);
311 
312 	return 0;
313 }
314 
315 void hisi_uncore_pmu_del(struct perf_event *event, int flags)
316 {
317 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
318 	struct hw_perf_event *hwc = &event->hw;
319 
320 	hisi_uncore_pmu_stop(event, PERF_EF_UPDATE);
321 	hisi_uncore_pmu_clear_event_idx(hisi_pmu, hwc->idx);
322 	perf_event_update_userpage(event);
323 	hisi_pmu->pmu_events.hw_events[hwc->idx] = NULL;
324 }
325 
326 void hisi_uncore_pmu_read(struct perf_event *event)
327 {
328 	/* Read hardware counter and update the perf counter statistics */
329 	hisi_uncore_pmu_event_update(event);
330 }
331 
332 void hisi_uncore_pmu_enable(struct pmu *pmu)
333 {
334 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(pmu);
335 	int enabled = bitmap_weight(hisi_pmu->pmu_events.used_mask,
336 				    hisi_pmu->num_counters);
337 
338 	if (!enabled)
339 		return;
340 
341 	hisi_pmu->ops->start_counters(hisi_pmu);
342 }
343 
344 void hisi_uncore_pmu_disable(struct pmu *pmu)
345 {
346 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(pmu);
347 
348 	hisi_pmu->ops->stop_counters(hisi_pmu);
349 }
350 
351 /*
352  * Read Super CPU cluster and CPU cluster ID from MPIDR_EL1.
353  * If multi-threading is supported, SCCL_ID is in MPIDR[aff3] and CCL_ID
354  * is in MPIDR[aff2]; if not, SCCL_ID is in MPIDR[aff2] and CCL_ID is
355  * in MPIDR[aff1]. If this changes in future, this shall be updated.
356  */
357 static void hisi_read_sccl_and_ccl_id(int *sccl_id, int *ccl_id)
358 {
359 	u64 mpidr = read_cpuid_mpidr();
360 
361 	if (mpidr & MPIDR_MT_BITMASK) {
362 		if (sccl_id)
363 			*sccl_id = MPIDR_AFFINITY_LEVEL(mpidr, 3);
364 		if (ccl_id)
365 			*ccl_id = MPIDR_AFFINITY_LEVEL(mpidr, 2);
366 	} else {
367 		if (sccl_id)
368 			*sccl_id = MPIDR_AFFINITY_LEVEL(mpidr, 2);
369 		if (ccl_id)
370 			*ccl_id = MPIDR_AFFINITY_LEVEL(mpidr, 1);
371 	}
372 }
373 
374 /*
375  * Check whether the CPU is associated with this uncore PMU
376  */
377 static bool hisi_pmu_cpu_is_associated_pmu(struct hisi_pmu *hisi_pmu)
378 {
379 	int sccl_id, ccl_id;
380 
381 	if (hisi_pmu->ccl_id == -1) {
382 		/* If CCL_ID is -1, the PMU only shares the same SCCL */
383 		hisi_read_sccl_and_ccl_id(&sccl_id, NULL);
384 
385 		return sccl_id == hisi_pmu->sccl_id;
386 	}
387 
388 	hisi_read_sccl_and_ccl_id(&sccl_id, &ccl_id);
389 
390 	return sccl_id == hisi_pmu->sccl_id && ccl_id == hisi_pmu->ccl_id;
391 }
392 
393 int hisi_uncore_pmu_online_cpu(unsigned int cpu, struct hlist_node *node)
394 {
395 	struct hisi_pmu *hisi_pmu = hlist_entry_safe(node, struct hisi_pmu,
396 						     node);
397 
398 	if (!hisi_pmu_cpu_is_associated_pmu(hisi_pmu))
399 		return 0;
400 
401 	cpumask_set_cpu(cpu, &hisi_pmu->associated_cpus);
402 
403 	/* If another CPU is already managing this PMU, simply return. */
404 	if (hisi_pmu->on_cpu != -1)
405 		return 0;
406 
407 	/* Use this CPU in cpumask for event counting */
408 	hisi_pmu->on_cpu = cpu;
409 
410 	/* Overflow interrupt also should use the same CPU */
411 	WARN_ON(irq_set_affinity(hisi_pmu->irq, cpumask_of(cpu)));
412 
413 	return 0;
414 }
415 
416 int hisi_uncore_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
417 {
418 	struct hisi_pmu *hisi_pmu = hlist_entry_safe(node, struct hisi_pmu,
419 						     node);
420 	cpumask_t pmu_online_cpus;
421 	unsigned int target;
422 
423 	if (!cpumask_test_and_clear_cpu(cpu, &hisi_pmu->associated_cpus))
424 		return 0;
425 
426 	/* Nothing to do if this CPU doesn't own the PMU */
427 	if (hisi_pmu->on_cpu != cpu)
428 		return 0;
429 
430 	/* Give up ownership of the PMU */
431 	hisi_pmu->on_cpu = -1;
432 
433 	/* Choose a new CPU to migrate ownership of the PMU to */
434 	cpumask_and(&pmu_online_cpus, &hisi_pmu->associated_cpus,
435 		    cpu_online_mask);
436 	target = cpumask_any_but(&pmu_online_cpus, cpu);
437 	if (target >= nr_cpu_ids)
438 		return 0;
439 
440 	perf_pmu_migrate_context(&hisi_pmu->pmu, cpu, target);
441 	/* Use this CPU for event counting */
442 	hisi_pmu->on_cpu = target;
443 	WARN_ON(irq_set_affinity(hisi_pmu->irq, cpumask_of(target)));
444 
445 	return 0;
446 }
447