1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * HiSilicon SoC Hardware event counters support
4  *
5  * Copyright (C) 2017 Hisilicon Limited
6  * Author: Anurup M <anurup.m@huawei.com>
7  *         Shaokun Zhang <zhangshaokun@hisilicon.com>
8  *
9  * This code is based on the uncore PMUs like arm-cci and arm-ccn.
10  */
11 #include <linux/bitmap.h>
12 #include <linux/bitops.h>
13 #include <linux/bug.h>
14 #include <linux/err.h>
15 #include <linux/errno.h>
16 #include <linux/interrupt.h>
17 
18 #include <asm/cputype.h>
19 #include <asm/local64.h>
20 
21 #include "hisi_uncore_pmu.h"
22 
23 #define HISI_GET_EVENTID(ev) (ev->hw.config_base & 0xff)
24 #define HISI_MAX_PERIOD(nr) (BIT_ULL(nr) - 1)
25 
26 /*
27  * PMU format attributes
28  */
29 ssize_t hisi_format_sysfs_show(struct device *dev,
30 			       struct device_attribute *attr, char *buf)
31 {
32 	struct dev_ext_attribute *eattr;
33 
34 	eattr = container_of(attr, struct dev_ext_attribute, attr);
35 
36 	return sprintf(buf, "%s\n", (char *)eattr->var);
37 }
38 
39 /*
40  * PMU event attributes
41  */
42 ssize_t hisi_event_sysfs_show(struct device *dev,
43 			      struct device_attribute *attr, char *page)
44 {
45 	struct dev_ext_attribute *eattr;
46 
47 	eattr = container_of(attr, struct dev_ext_attribute, attr);
48 
49 	return sprintf(page, "config=0x%lx\n", (unsigned long)eattr->var);
50 }
51 
52 /*
53  * sysfs cpumask attributes. For uncore PMU, we only have a single CPU to show
54  */
55 ssize_t hisi_cpumask_sysfs_show(struct device *dev,
56 				struct device_attribute *attr, char *buf)
57 {
58 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(dev_get_drvdata(dev));
59 
60 	return sprintf(buf, "%d\n", hisi_pmu->on_cpu);
61 }
62 
63 static bool hisi_validate_event_group(struct perf_event *event)
64 {
65 	struct perf_event *sibling, *leader = event->group_leader;
66 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
67 	/* Include count for the event */
68 	int counters = 1;
69 
70 	if (!is_software_event(leader)) {
71 		/*
72 		 * We must NOT create groups containing mixed PMUs, although
73 		 * software events are acceptable
74 		 */
75 		if (leader->pmu != event->pmu)
76 			return false;
77 
78 		/* Increment counter for the leader */
79 		if (leader != event)
80 			counters++;
81 	}
82 
83 	for_each_sibling_event(sibling, event->group_leader) {
84 		if (is_software_event(sibling))
85 			continue;
86 		if (sibling->pmu != event->pmu)
87 			return false;
88 		/* Increment counter for each sibling */
89 		counters++;
90 	}
91 
92 	/* The group can not count events more than the counters in the HW */
93 	return counters <= hisi_pmu->num_counters;
94 }
95 
96 int hisi_uncore_pmu_counter_valid(struct hisi_pmu *hisi_pmu, int idx)
97 {
98 	return idx >= 0 && idx < hisi_pmu->num_counters;
99 }
100 
101 int hisi_uncore_pmu_get_event_idx(struct perf_event *event)
102 {
103 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
104 	unsigned long *used_mask = hisi_pmu->pmu_events.used_mask;
105 	u32 num_counters = hisi_pmu->num_counters;
106 	int idx;
107 
108 	idx = find_first_zero_bit(used_mask, num_counters);
109 	if (idx == num_counters)
110 		return -EAGAIN;
111 
112 	set_bit(idx, used_mask);
113 
114 	return idx;
115 }
116 
117 static void hisi_uncore_pmu_clear_event_idx(struct hisi_pmu *hisi_pmu, int idx)
118 {
119 	if (!hisi_uncore_pmu_counter_valid(hisi_pmu, idx)) {
120 		dev_err(hisi_pmu->dev, "Unsupported event index:%d!\n", idx);
121 		return;
122 	}
123 
124 	clear_bit(idx, hisi_pmu->pmu_events.used_mask);
125 }
126 
127 int hisi_uncore_pmu_event_init(struct perf_event *event)
128 {
129 	struct hw_perf_event *hwc = &event->hw;
130 	struct hisi_pmu *hisi_pmu;
131 
132 	if (event->attr.type != event->pmu->type)
133 		return -ENOENT;
134 
135 	/*
136 	 * We do not support sampling as the counters are all
137 	 * shared by all CPU cores in a CPU die(SCCL). Also we
138 	 * do not support attach to a task(per-process mode)
139 	 */
140 	if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
141 		return -EOPNOTSUPP;
142 
143 	/*
144 	 *  The uncore counters not specific to any CPU, so cannot
145 	 *  support per-task
146 	 */
147 	if (event->cpu < 0)
148 		return -EINVAL;
149 
150 	/*
151 	 * Validate if the events in group does not exceed the
152 	 * available counters in hardware.
153 	 */
154 	if (!hisi_validate_event_group(event))
155 		return -EINVAL;
156 
157 	hisi_pmu = to_hisi_pmu(event->pmu);
158 	if (event->attr.config > hisi_pmu->check_event)
159 		return -EINVAL;
160 
161 	if (hisi_pmu->on_cpu == -1)
162 		return -EINVAL;
163 	/*
164 	 * We don't assign an index until we actually place the event onto
165 	 * hardware. Use -1 to signify that we haven't decided where to put it
166 	 * yet.
167 	 */
168 	hwc->idx		= -1;
169 	hwc->config_base	= event->attr.config;
170 
171 	/* Enforce to use the same CPU for all events in this PMU */
172 	event->cpu = hisi_pmu->on_cpu;
173 
174 	return 0;
175 }
176 
177 /*
178  * Set the counter to count the event that we're interested in,
179  * and enable interrupt and counter.
180  */
181 static void hisi_uncore_pmu_enable_event(struct perf_event *event)
182 {
183 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
184 	struct hw_perf_event *hwc = &event->hw;
185 
186 	hisi_pmu->ops->write_evtype(hisi_pmu, hwc->idx,
187 				    HISI_GET_EVENTID(event));
188 
189 	hisi_pmu->ops->enable_counter_int(hisi_pmu, hwc);
190 	hisi_pmu->ops->enable_counter(hisi_pmu, hwc);
191 }
192 
193 /*
194  * Disable counter and interrupt.
195  */
196 static void hisi_uncore_pmu_disable_event(struct perf_event *event)
197 {
198 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
199 	struct hw_perf_event *hwc = &event->hw;
200 
201 	hisi_pmu->ops->disable_counter(hisi_pmu, hwc);
202 	hisi_pmu->ops->disable_counter_int(hisi_pmu, hwc);
203 }
204 
205 void hisi_uncore_pmu_set_event_period(struct perf_event *event)
206 {
207 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
208 	struct hw_perf_event *hwc = &event->hw;
209 
210 	/*
211 	 * The HiSilicon PMU counters support 32 bits or 48 bits, depending on
212 	 * the PMU. We reduce it to 2^(counter_bits - 1) to account for the
213 	 * extreme interrupt latency. So we could hopefully handle the overflow
214 	 * interrupt before another 2^(counter_bits - 1) events occur and the
215 	 * counter overtakes its previous value.
216 	 */
217 	u64 val = BIT_ULL(hisi_pmu->counter_bits - 1);
218 
219 	local64_set(&hwc->prev_count, val);
220 	/* Write start value to the hardware event counter */
221 	hisi_pmu->ops->write_counter(hisi_pmu, hwc, val);
222 }
223 
224 void hisi_uncore_pmu_event_update(struct perf_event *event)
225 {
226 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
227 	struct hw_perf_event *hwc = &event->hw;
228 	u64 delta, prev_raw_count, new_raw_count;
229 
230 	do {
231 		/* Read the count from the counter register */
232 		new_raw_count = hisi_pmu->ops->read_counter(hisi_pmu, hwc);
233 		prev_raw_count = local64_read(&hwc->prev_count);
234 	} while (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
235 				 new_raw_count) != prev_raw_count);
236 	/*
237 	 * compute the delta
238 	 */
239 	delta = (new_raw_count - prev_raw_count) &
240 		HISI_MAX_PERIOD(hisi_pmu->counter_bits);
241 	local64_add(delta, &event->count);
242 }
243 
244 void hisi_uncore_pmu_start(struct perf_event *event, int flags)
245 {
246 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
247 	struct hw_perf_event *hwc = &event->hw;
248 
249 	if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
250 		return;
251 
252 	WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
253 	hwc->state = 0;
254 	hisi_uncore_pmu_set_event_period(event);
255 
256 	if (flags & PERF_EF_RELOAD) {
257 		u64 prev_raw_count =  local64_read(&hwc->prev_count);
258 
259 		hisi_pmu->ops->write_counter(hisi_pmu, hwc, prev_raw_count);
260 	}
261 
262 	hisi_uncore_pmu_enable_event(event);
263 	perf_event_update_userpage(event);
264 }
265 
266 void hisi_uncore_pmu_stop(struct perf_event *event, int flags)
267 {
268 	struct hw_perf_event *hwc = &event->hw;
269 
270 	hisi_uncore_pmu_disable_event(event);
271 	WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
272 	hwc->state |= PERF_HES_STOPPED;
273 
274 	if (hwc->state & PERF_HES_UPTODATE)
275 		return;
276 
277 	/* Read hardware counter and update the perf counter statistics */
278 	hisi_uncore_pmu_event_update(event);
279 	hwc->state |= PERF_HES_UPTODATE;
280 }
281 
282 int hisi_uncore_pmu_add(struct perf_event *event, int flags)
283 {
284 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
285 	struct hw_perf_event *hwc = &event->hw;
286 	int idx;
287 
288 	hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
289 
290 	/* Get an available counter index for counting */
291 	idx = hisi_pmu->ops->get_event_idx(event);
292 	if (idx < 0)
293 		return idx;
294 
295 	event->hw.idx = idx;
296 	hisi_pmu->pmu_events.hw_events[idx] = event;
297 
298 	if (flags & PERF_EF_START)
299 		hisi_uncore_pmu_start(event, PERF_EF_RELOAD);
300 
301 	return 0;
302 }
303 
304 void hisi_uncore_pmu_del(struct perf_event *event, int flags)
305 {
306 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(event->pmu);
307 	struct hw_perf_event *hwc = &event->hw;
308 
309 	hisi_uncore_pmu_stop(event, PERF_EF_UPDATE);
310 	hisi_uncore_pmu_clear_event_idx(hisi_pmu, hwc->idx);
311 	perf_event_update_userpage(event);
312 	hisi_pmu->pmu_events.hw_events[hwc->idx] = NULL;
313 }
314 
315 void hisi_uncore_pmu_read(struct perf_event *event)
316 {
317 	/* Read hardware counter and update the perf counter statistics */
318 	hisi_uncore_pmu_event_update(event);
319 }
320 
321 void hisi_uncore_pmu_enable(struct pmu *pmu)
322 {
323 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(pmu);
324 	int enabled = bitmap_weight(hisi_pmu->pmu_events.used_mask,
325 				    hisi_pmu->num_counters);
326 
327 	if (!enabled)
328 		return;
329 
330 	hisi_pmu->ops->start_counters(hisi_pmu);
331 }
332 
333 void hisi_uncore_pmu_disable(struct pmu *pmu)
334 {
335 	struct hisi_pmu *hisi_pmu = to_hisi_pmu(pmu);
336 
337 	hisi_pmu->ops->stop_counters(hisi_pmu);
338 }
339 
340 
341 /*
342  * The Super CPU Cluster (SCCL) and CPU Cluster (CCL) IDs can be
343  * determined from the MPIDR_EL1, but the encoding varies by CPU:
344  *
345  * - For MT variants of TSV110:
346  *   SCCL is Aff2[7:3], CCL is Aff2[2:0]
347  *
348  * - For other MT parts:
349  *   SCCL is Aff3[7:0], CCL is Aff2[7:0]
350  *
351  * - For non-MT parts:
352  *   SCCL is Aff2[7:0], CCL is Aff1[7:0]
353  */
354 static void hisi_read_sccl_and_ccl_id(int *scclp, int *cclp)
355 {
356 	u64 mpidr = read_cpuid_mpidr();
357 	int aff3 = MPIDR_AFFINITY_LEVEL(mpidr, 3);
358 	int aff2 = MPIDR_AFFINITY_LEVEL(mpidr, 2);
359 	int aff1 = MPIDR_AFFINITY_LEVEL(mpidr, 1);
360 	bool mt = mpidr & MPIDR_MT_BITMASK;
361 	int sccl, ccl;
362 
363 	if (mt && read_cpuid_part_number() == HISI_CPU_PART_TSV110) {
364 		sccl = aff2 >> 3;
365 		ccl = aff2 & 0x7;
366 	} else if (mt) {
367 		sccl = aff3;
368 		ccl = aff2;
369 	} else {
370 		sccl = aff2;
371 		ccl = aff1;
372 	}
373 
374 	if (scclp)
375 		*scclp = sccl;
376 	if (cclp)
377 		*cclp = ccl;
378 }
379 
380 /*
381  * Check whether the CPU is associated with this uncore PMU
382  */
383 static bool hisi_pmu_cpu_is_associated_pmu(struct hisi_pmu *hisi_pmu)
384 {
385 	int sccl_id, ccl_id;
386 
387 	if (hisi_pmu->ccl_id == -1) {
388 		/* If CCL_ID is -1, the PMU only shares the same SCCL */
389 		hisi_read_sccl_and_ccl_id(&sccl_id, NULL);
390 
391 		return sccl_id == hisi_pmu->sccl_id;
392 	}
393 
394 	hisi_read_sccl_and_ccl_id(&sccl_id, &ccl_id);
395 
396 	return sccl_id == hisi_pmu->sccl_id && ccl_id == hisi_pmu->ccl_id;
397 }
398 
399 int hisi_uncore_pmu_online_cpu(unsigned int cpu, struct hlist_node *node)
400 {
401 	struct hisi_pmu *hisi_pmu = hlist_entry_safe(node, struct hisi_pmu,
402 						     node);
403 
404 	if (!hisi_pmu_cpu_is_associated_pmu(hisi_pmu))
405 		return 0;
406 
407 	cpumask_set_cpu(cpu, &hisi_pmu->associated_cpus);
408 
409 	/* If another CPU is already managing this PMU, simply return. */
410 	if (hisi_pmu->on_cpu != -1)
411 		return 0;
412 
413 	/* Use this CPU in cpumask for event counting */
414 	hisi_pmu->on_cpu = cpu;
415 
416 	/* Overflow interrupt also should use the same CPU */
417 	WARN_ON(irq_set_affinity(hisi_pmu->irq, cpumask_of(cpu)));
418 
419 	return 0;
420 }
421 
422 int hisi_uncore_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
423 {
424 	struct hisi_pmu *hisi_pmu = hlist_entry_safe(node, struct hisi_pmu,
425 						     node);
426 	cpumask_t pmu_online_cpus;
427 	unsigned int target;
428 
429 	if (!cpumask_test_and_clear_cpu(cpu, &hisi_pmu->associated_cpus))
430 		return 0;
431 
432 	/* Nothing to do if this CPU doesn't own the PMU */
433 	if (hisi_pmu->on_cpu != cpu)
434 		return 0;
435 
436 	/* Give up ownership of the PMU */
437 	hisi_pmu->on_cpu = -1;
438 
439 	/* Choose a new CPU to migrate ownership of the PMU to */
440 	cpumask_and(&pmu_online_cpus, &hisi_pmu->associated_cpus,
441 		    cpu_online_mask);
442 	target = cpumask_any_but(&pmu_online_cpus, cpu);
443 	if (target >= nr_cpu_ids)
444 		return 0;
445 
446 	perf_pmu_migrate_context(&hisi_pmu->pmu, cpu, target);
447 	/* Use this CPU for event counting */
448 	hisi_pmu->on_cpu = target;
449 	WARN_ON(irq_set_affinity(hisi_pmu->irq, cpumask_of(target)));
450 
451 	return 0;
452 }
453