1// SPDX-License-Identifier: GPL-2.0
2/*
3 * RISC-V performance counter support.
4 *
5 * Copyright (C) 2021 Western Digital Corporation or its affiliates.
6 *
7 * This code is based on ARM perf event code which is in turn based on
8 * sparc64 and x86 code.
9 */
10
11#define pr_fmt(fmt) "riscv-pmu-sbi: " fmt
12
13#include <linux/mod_devicetable.h>
14#include <linux/perf/riscv_pmu.h>
15#include <linux/platform_device.h>
16#include <linux/irq.h>
17#include <linux/irqdomain.h>
18#include <linux/of_irq.h>
19#include <linux/of.h>
20#include <linux/cpu_pm.h>
21#include <linux/sched/clock.h>
22
23#include <asm/errata_list.h>
24#include <asm/sbi.h>
25#include <asm/hwcap.h>
26
27#define SYSCTL_NO_USER_ACCESS	0
28#define SYSCTL_USER_ACCESS	1
29#define SYSCTL_LEGACY		2
30
31#define PERF_EVENT_FLAG_NO_USER_ACCESS	BIT(SYSCTL_NO_USER_ACCESS)
32#define PERF_EVENT_FLAG_USER_ACCESS	BIT(SYSCTL_USER_ACCESS)
33#define PERF_EVENT_FLAG_LEGACY		BIT(SYSCTL_LEGACY)
34
35PMU_FORMAT_ATTR(event, "config:0-47");
36PMU_FORMAT_ATTR(firmware, "config:63");
37
38static struct attribute *riscv_arch_formats_attr[] = {
39	&format_attr_event.attr,
40	&format_attr_firmware.attr,
41	NULL,
42};
43
44static struct attribute_group riscv_pmu_format_group = {
45	.name = "format",
46	.attrs = riscv_arch_formats_attr,
47};
48
49static const struct attribute_group *riscv_pmu_attr_groups[] = {
50	&riscv_pmu_format_group,
51	NULL,
52};
53
54/* Allow user mode access by default */
55static int sysctl_perf_user_access __read_mostly = SYSCTL_USER_ACCESS;
56
57/*
58 * RISC-V doesn't have heterogeneous harts yet. This need to be part of
59 * per_cpu in case of harts with different pmu counters
60 */
61static union sbi_pmu_ctr_info *pmu_ctr_list;
62static bool riscv_pmu_use_irq;
63static unsigned int riscv_pmu_irq_num;
64static unsigned int riscv_pmu_irq;
65
66/* Cache the available counters in a bitmask */
67static unsigned long cmask;
68
69struct sbi_pmu_event_data {
70	union {
71		union {
72			struct hw_gen_event {
73				uint32_t event_code:16;
74				uint32_t event_type:4;
75				uint32_t reserved:12;
76			} hw_gen_event;
77			struct hw_cache_event {
78				uint32_t result_id:1;
79				uint32_t op_id:2;
80				uint32_t cache_id:13;
81				uint32_t event_type:4;
82				uint32_t reserved:12;
83			} hw_cache_event;
84		};
85		uint32_t event_idx;
86	};
87};
88
89static const struct sbi_pmu_event_data pmu_hw_event_map[] = {
90	[PERF_COUNT_HW_CPU_CYCLES]		= {.hw_gen_event = {
91							SBI_PMU_HW_CPU_CYCLES,
92							SBI_PMU_EVENT_TYPE_HW, 0}},
93	[PERF_COUNT_HW_INSTRUCTIONS]		= {.hw_gen_event = {
94							SBI_PMU_HW_INSTRUCTIONS,
95							SBI_PMU_EVENT_TYPE_HW, 0}},
96	[PERF_COUNT_HW_CACHE_REFERENCES]	= {.hw_gen_event = {
97							SBI_PMU_HW_CACHE_REFERENCES,
98							SBI_PMU_EVENT_TYPE_HW, 0}},
99	[PERF_COUNT_HW_CACHE_MISSES]		= {.hw_gen_event = {
100							SBI_PMU_HW_CACHE_MISSES,
101							SBI_PMU_EVENT_TYPE_HW, 0}},
102	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= {.hw_gen_event = {
103							SBI_PMU_HW_BRANCH_INSTRUCTIONS,
104							SBI_PMU_EVENT_TYPE_HW, 0}},
105	[PERF_COUNT_HW_BRANCH_MISSES]		= {.hw_gen_event = {
106							SBI_PMU_HW_BRANCH_MISSES,
107							SBI_PMU_EVENT_TYPE_HW, 0}},
108	[PERF_COUNT_HW_BUS_CYCLES]		= {.hw_gen_event = {
109							SBI_PMU_HW_BUS_CYCLES,
110							SBI_PMU_EVENT_TYPE_HW, 0}},
111	[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND]	= {.hw_gen_event = {
112							SBI_PMU_HW_STALLED_CYCLES_FRONTEND,
113							SBI_PMU_EVENT_TYPE_HW, 0}},
114	[PERF_COUNT_HW_STALLED_CYCLES_BACKEND]	= {.hw_gen_event = {
115							SBI_PMU_HW_STALLED_CYCLES_BACKEND,
116							SBI_PMU_EVENT_TYPE_HW, 0}},
117	[PERF_COUNT_HW_REF_CPU_CYCLES]		= {.hw_gen_event = {
118							SBI_PMU_HW_REF_CPU_CYCLES,
119							SBI_PMU_EVENT_TYPE_HW, 0}},
120};
121
122#define C(x) PERF_COUNT_HW_CACHE_##x
123static const struct sbi_pmu_event_data pmu_cache_event_map[PERF_COUNT_HW_CACHE_MAX]
124[PERF_COUNT_HW_CACHE_OP_MAX]
125[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
126	[C(L1D)] = {
127		[C(OP_READ)] = {
128			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
129					C(OP_READ), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
130			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
131					C(OP_READ), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
132		},
133		[C(OP_WRITE)] = {
134			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
135					C(OP_WRITE), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
136			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
137					C(OP_WRITE), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
138		},
139		[C(OP_PREFETCH)] = {
140			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
141					C(OP_PREFETCH), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
142			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
143					C(OP_PREFETCH), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
144		},
145	},
146	[C(L1I)] = {
147		[C(OP_READ)] = {
148			[C(RESULT_ACCESS)] = {.hw_cache_event =	{C(RESULT_ACCESS),
149					C(OP_READ), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
150			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_READ),
151					C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
152		},
153		[C(OP_WRITE)] = {
154			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
155					C(OP_WRITE), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
156			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
157					C(OP_WRITE), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
158		},
159		[C(OP_PREFETCH)] = {
160			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
161					C(OP_PREFETCH), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
162			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
163					C(OP_PREFETCH), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
164		},
165	},
166	[C(LL)] = {
167		[C(OP_READ)] = {
168			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
169					C(OP_READ), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
170			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
171					C(OP_READ), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
172		},
173		[C(OP_WRITE)] = {
174			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
175					C(OP_WRITE), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
176			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
177					C(OP_WRITE), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
178		},
179		[C(OP_PREFETCH)] = {
180			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
181					C(OP_PREFETCH), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
182			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
183					C(OP_PREFETCH), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
184		},
185	},
186	[C(DTLB)] = {
187		[C(OP_READ)] = {
188			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
189					C(OP_READ), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
190			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
191					C(OP_READ), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
192		},
193		[C(OP_WRITE)] = {
194			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
195					C(OP_WRITE), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
196			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
197					C(OP_WRITE), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
198		},
199		[C(OP_PREFETCH)] = {
200			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
201					C(OP_PREFETCH), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
202			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
203					C(OP_PREFETCH), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
204		},
205	},
206	[C(ITLB)] = {
207		[C(OP_READ)] = {
208			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
209					C(OP_READ), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
210			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
211					C(OP_READ), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
212		},
213		[C(OP_WRITE)] = {
214			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
215					C(OP_WRITE), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
216			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
217					C(OP_WRITE), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
218		},
219		[C(OP_PREFETCH)] = {
220			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
221					C(OP_PREFETCH), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
222			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
223					C(OP_PREFETCH), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
224		},
225	},
226	[C(BPU)] = {
227		[C(OP_READ)] = {
228			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
229					C(OP_READ), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
230			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
231					C(OP_READ), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
232		},
233		[C(OP_WRITE)] = {
234			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
235					C(OP_WRITE), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
236			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
237					C(OP_WRITE), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
238		},
239		[C(OP_PREFETCH)] = {
240			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
241					C(OP_PREFETCH), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
242			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
243					C(OP_PREFETCH), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
244		},
245	},
246	[C(NODE)] = {
247		[C(OP_READ)] = {
248			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
249					C(OP_READ), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
250			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
251					C(OP_READ), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
252		},
253		[C(OP_WRITE)] = {
254			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
255					C(OP_WRITE), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
256			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
257					C(OP_WRITE), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
258		},
259		[C(OP_PREFETCH)] = {
260			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
261					C(OP_PREFETCH), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
262			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
263					C(OP_PREFETCH), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
264		},
265	},
266};
267
268static int pmu_sbi_ctr_get_width(int idx)
269{
270	return pmu_ctr_list[idx].width;
271}
272
273static bool pmu_sbi_ctr_is_fw(int cidx)
274{
275	union sbi_pmu_ctr_info *info;
276
277	info = &pmu_ctr_list[cidx];
278	if (!info)
279		return false;
280
281	return (info->type == SBI_PMU_CTR_TYPE_FW) ? true : false;
282}
283
284/*
285 * Returns the counter width of a programmable counter and number of hardware
286 * counters. As we don't support heterogeneous CPUs yet, it is okay to just
287 * return the counter width of the first programmable counter.
288 */
289int riscv_pmu_get_hpm_info(u32 *hw_ctr_width, u32 *num_hw_ctr)
290{
291	int i;
292	union sbi_pmu_ctr_info *info;
293	u32 hpm_width = 0, hpm_count = 0;
294
295	if (!cmask)
296		return -EINVAL;
297
298	for_each_set_bit(i, &cmask, RISCV_MAX_COUNTERS) {
299		info = &pmu_ctr_list[i];
300		if (!info)
301			continue;
302		if (!hpm_width && info->csr != CSR_CYCLE && info->csr != CSR_INSTRET)
303			hpm_width = info->width;
304		if (info->type == SBI_PMU_CTR_TYPE_HW)
305			hpm_count++;
306	}
307
308	*hw_ctr_width = hpm_width;
309	*num_hw_ctr = hpm_count;
310
311	return 0;
312}
313EXPORT_SYMBOL_GPL(riscv_pmu_get_hpm_info);
314
315static uint8_t pmu_sbi_csr_index(struct perf_event *event)
316{
317	return pmu_ctr_list[event->hw.idx].csr - CSR_CYCLE;
318}
319
320static unsigned long pmu_sbi_get_filter_flags(struct perf_event *event)
321{
322	unsigned long cflags = 0;
323	bool guest_events = false;
324
325	if (event->attr.config1 & RISCV_PMU_CONFIG1_GUEST_EVENTS)
326		guest_events = true;
327	if (event->attr.exclude_kernel)
328		cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VSINH : SBI_PMU_CFG_FLAG_SET_SINH;
329	if (event->attr.exclude_user)
330		cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VUINH : SBI_PMU_CFG_FLAG_SET_UINH;
331	if (guest_events && event->attr.exclude_hv)
332		cflags |= SBI_PMU_CFG_FLAG_SET_SINH;
333	if (event->attr.exclude_host)
334		cflags |= SBI_PMU_CFG_FLAG_SET_UINH | SBI_PMU_CFG_FLAG_SET_SINH;
335	if (event->attr.exclude_guest)
336		cflags |= SBI_PMU_CFG_FLAG_SET_VSINH | SBI_PMU_CFG_FLAG_SET_VUINH;
337
338	return cflags;
339}
340
341static int pmu_sbi_ctr_get_idx(struct perf_event *event)
342{
343	struct hw_perf_event *hwc = &event->hw;
344	struct riscv_pmu *rvpmu = to_riscv_pmu(event->pmu);
345	struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events);
346	struct sbiret ret;
347	int idx;
348	uint64_t cbase = 0, cmask = rvpmu->cmask;
349	unsigned long cflags = 0;
350
351	cflags = pmu_sbi_get_filter_flags(event);
352
353	/*
354	 * In legacy mode, we have to force the fixed counters for those events
355	 * but not in the user access mode as we want to use the other counters
356	 * that support sampling/filtering.
357	 */
358	if (hwc->flags & PERF_EVENT_FLAG_LEGACY) {
359		if (event->attr.config == PERF_COUNT_HW_CPU_CYCLES) {
360			cflags |= SBI_PMU_CFG_FLAG_SKIP_MATCH;
361			cmask = 1;
362		} else if (event->attr.config == PERF_COUNT_HW_INSTRUCTIONS) {
363			cflags |= SBI_PMU_CFG_FLAG_SKIP_MATCH;
364			cmask = 1UL << (CSR_INSTRET - CSR_CYCLE);
365		}
366	}
367
368	/* retrieve the available counter index */
369#if defined(CONFIG_32BIT)
370	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase,
371			cmask, cflags, hwc->event_base, hwc->config,
372			hwc->config >> 32);
373#else
374	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase,
375			cmask, cflags, hwc->event_base, hwc->config, 0);
376#endif
377	if (ret.error) {
378		pr_debug("Not able to find a counter for event %lx config %llx\n",
379			hwc->event_base, hwc->config);
380		return sbi_err_map_linux_errno(ret.error);
381	}
382
383	idx = ret.value;
384	if (!test_bit(idx, &rvpmu->cmask) || !pmu_ctr_list[idx].value)
385		return -ENOENT;
386
387	/* Additional sanity check for the counter id */
388	if (pmu_sbi_ctr_is_fw(idx)) {
389		if (!test_and_set_bit(idx, cpuc->used_fw_ctrs))
390			return idx;
391	} else {
392		if (!test_and_set_bit(idx, cpuc->used_hw_ctrs))
393			return idx;
394	}
395
396	return -ENOENT;
397}
398
399static void pmu_sbi_ctr_clear_idx(struct perf_event *event)
400{
401
402	struct hw_perf_event *hwc = &event->hw;
403	struct riscv_pmu *rvpmu = to_riscv_pmu(event->pmu);
404	struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events);
405	int idx = hwc->idx;
406
407	if (pmu_sbi_ctr_is_fw(idx))
408		clear_bit(idx, cpuc->used_fw_ctrs);
409	else
410		clear_bit(idx, cpuc->used_hw_ctrs);
411}
412
413static int pmu_event_find_cache(u64 config)
414{
415	unsigned int cache_type, cache_op, cache_result, ret;
416
417	cache_type = (config >>  0) & 0xff;
418	if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
419		return -EINVAL;
420
421	cache_op = (config >>  8) & 0xff;
422	if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
423		return -EINVAL;
424
425	cache_result = (config >> 16) & 0xff;
426	if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
427		return -EINVAL;
428
429	ret = pmu_cache_event_map[cache_type][cache_op][cache_result].event_idx;
430
431	return ret;
432}
433
434static bool pmu_sbi_is_fw_event(struct perf_event *event)
435{
436	u32 type = event->attr.type;
437	u64 config = event->attr.config;
438
439	if ((type == PERF_TYPE_RAW) && ((config >> 63) == 1))
440		return true;
441	else
442		return false;
443}
444
445static int pmu_sbi_event_map(struct perf_event *event, u64 *econfig)
446{
447	u32 type = event->attr.type;
448	u64 config = event->attr.config;
449	int bSoftware;
450	u64 raw_config_val;
451	int ret;
452
453	switch (type) {
454	case PERF_TYPE_HARDWARE:
455		if (config >= PERF_COUNT_HW_MAX)
456			return -EINVAL;
457		ret = pmu_hw_event_map[event->attr.config].event_idx;
458		break;
459	case PERF_TYPE_HW_CACHE:
460		ret = pmu_event_find_cache(config);
461		break;
462	case PERF_TYPE_RAW:
463		/*
464		 * As per SBI specification, the upper 16 bits must be unused for
465		 * a raw event. Use the MSB (63b) to distinguish between hardware
466		 * raw event and firmware events.
467		 */
468		bSoftware = config >> 63;
469		raw_config_val = config & RISCV_PMU_RAW_EVENT_MASK;
470		if (bSoftware) {
471			ret = (raw_config_val & 0xFFFF) |
472				(SBI_PMU_EVENT_TYPE_FW << 16);
473		} else {
474			ret = RISCV_PMU_RAW_EVENT_IDX;
475			*econfig = raw_config_val;
476		}
477		break;
478	default:
479		ret = -EINVAL;
480		break;
481	}
482
483	return ret;
484}
485
486static u64 pmu_sbi_ctr_read(struct perf_event *event)
487{
488	struct hw_perf_event *hwc = &event->hw;
489	int idx = hwc->idx;
490	struct sbiret ret;
491	union sbi_pmu_ctr_info info;
492	u64 val = 0;
493
494	if (pmu_sbi_is_fw_event(event)) {
495		ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_FW_READ,
496				hwc->idx, 0, 0, 0, 0, 0);
497		if (!ret.error)
498			val = ret.value;
499	} else {
500		info = pmu_ctr_list[idx];
501		val = riscv_pmu_ctr_read_csr(info.csr);
502		if (IS_ENABLED(CONFIG_32BIT))
503			val = ((u64)riscv_pmu_ctr_read_csr(info.csr + 0x80)) << 31 | val;
504	}
505
506	return val;
507}
508
509static void pmu_sbi_set_scounteren(void *arg)
510{
511	struct perf_event *event = (struct perf_event *)arg;
512
513	if (event->hw.idx != -1)
514		csr_write(CSR_SCOUNTEREN,
515			  csr_read(CSR_SCOUNTEREN) | BIT(pmu_sbi_csr_index(event)));
516}
517
518static void pmu_sbi_reset_scounteren(void *arg)
519{
520	struct perf_event *event = (struct perf_event *)arg;
521
522	if (event->hw.idx != -1)
523		csr_write(CSR_SCOUNTEREN,
524			  csr_read(CSR_SCOUNTEREN) & ~BIT(pmu_sbi_csr_index(event)));
525}
526
527static void pmu_sbi_ctr_start(struct perf_event *event, u64 ival)
528{
529	struct sbiret ret;
530	struct hw_perf_event *hwc = &event->hw;
531	unsigned long flag = SBI_PMU_START_FLAG_SET_INIT_VALUE;
532
533#if defined(CONFIG_32BIT)
534	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, hwc->idx,
535			1, flag, ival, ival >> 32, 0);
536#else
537	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, hwc->idx,
538			1, flag, ival, 0, 0);
539#endif
540	if (ret.error && (ret.error != SBI_ERR_ALREADY_STARTED))
541		pr_err("Starting counter idx %d failed with error %d\n",
542			hwc->idx, sbi_err_map_linux_errno(ret.error));
543
544	if ((hwc->flags & PERF_EVENT_FLAG_USER_ACCESS) &&
545	    (hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT))
546		pmu_sbi_set_scounteren((void *)event);
547}
548
549static void pmu_sbi_ctr_stop(struct perf_event *event, unsigned long flag)
550{
551	struct sbiret ret;
552	struct hw_perf_event *hwc = &event->hw;
553
554	if ((hwc->flags & PERF_EVENT_FLAG_USER_ACCESS) &&
555	    (hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT))
556		pmu_sbi_reset_scounteren((void *)event);
557
558	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, hwc->idx, 1, flag, 0, 0, 0);
559	if (ret.error && (ret.error != SBI_ERR_ALREADY_STOPPED) &&
560		flag != SBI_PMU_STOP_FLAG_RESET)
561		pr_err("Stopping counter idx %d failed with error %d\n",
562			hwc->idx, sbi_err_map_linux_errno(ret.error));
563}
564
565static int pmu_sbi_find_num_ctrs(void)
566{
567	struct sbiret ret;
568
569	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_NUM_COUNTERS, 0, 0, 0, 0, 0, 0);
570	if (!ret.error)
571		return ret.value;
572	else
573		return sbi_err_map_linux_errno(ret.error);
574}
575
576static int pmu_sbi_get_ctrinfo(int nctr, unsigned long *mask)
577{
578	struct sbiret ret;
579	int i, num_hw_ctr = 0, num_fw_ctr = 0;
580	union sbi_pmu_ctr_info cinfo;
581
582	pmu_ctr_list = kcalloc(nctr, sizeof(*pmu_ctr_list), GFP_KERNEL);
583	if (!pmu_ctr_list)
584		return -ENOMEM;
585
586	for (i = 0; i < nctr; i++) {
587		ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_GET_INFO, i, 0, 0, 0, 0, 0);
588		if (ret.error)
589			/* The logical counter ids are not expected to be contiguous */
590			continue;
591
592		*mask |= BIT(i);
593
594		cinfo.value = ret.value;
595		if (cinfo.type == SBI_PMU_CTR_TYPE_FW)
596			num_fw_ctr++;
597		else
598			num_hw_ctr++;
599		pmu_ctr_list[i].value = cinfo.value;
600	}
601
602	pr_info("%d firmware and %d hardware counters\n", num_fw_ctr, num_hw_ctr);
603
604	return 0;
605}
606
607static inline void pmu_sbi_stop_all(struct riscv_pmu *pmu)
608{
609	/*
610	 * No need to check the error because we are disabling all the counters
611	 * which may include counters that are not enabled yet.
612	 */
613	sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP,
614		  0, pmu->cmask, 0, 0, 0, 0);
615}
616
617static inline void pmu_sbi_stop_hw_ctrs(struct riscv_pmu *pmu)
618{
619	struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
620
621	/* No need to check the error here as we can't do anything about the error */
622	sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, 0,
623		  cpu_hw_evt->used_hw_ctrs[0], 0, 0, 0, 0);
624}
625
626/*
627 * This function starts all the used counters in two step approach.
628 * Any counter that did not overflow can be start in a single step
629 * while the overflowed counters need to be started with updated initialization
630 * value.
631 */
632static inline void pmu_sbi_start_overflow_mask(struct riscv_pmu *pmu,
633					       unsigned long ctr_ovf_mask)
634{
635	int idx = 0;
636	struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
637	struct perf_event *event;
638	unsigned long flag = SBI_PMU_START_FLAG_SET_INIT_VALUE;
639	unsigned long ctr_start_mask = 0;
640	uint64_t max_period;
641	struct hw_perf_event *hwc;
642	u64 init_val = 0;
643
644	ctr_start_mask = cpu_hw_evt->used_hw_ctrs[0] & ~ctr_ovf_mask;
645
646	/* Start all the counters that did not overflow in a single shot */
647	sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, 0, ctr_start_mask,
648		  0, 0, 0, 0);
649
650	/* Reinitialize and start all the counter that overflowed */
651	while (ctr_ovf_mask) {
652		if (ctr_ovf_mask & 0x01) {
653			event = cpu_hw_evt->events[idx];
654			hwc = &event->hw;
655			max_period = riscv_pmu_ctr_get_width_mask(event);
656			init_val = local64_read(&hwc->prev_count) & max_period;
657#if defined(CONFIG_32BIT)
658			sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx, 1,
659				  flag, init_val, init_val >> 32, 0);
660#else
661			sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx, 1,
662				  flag, init_val, 0, 0);
663#endif
664			perf_event_update_userpage(event);
665		}
666		ctr_ovf_mask = ctr_ovf_mask >> 1;
667		idx++;
668	}
669}
670
671static irqreturn_t pmu_sbi_ovf_handler(int irq, void *dev)
672{
673	struct perf_sample_data data;
674	struct pt_regs *regs;
675	struct hw_perf_event *hw_evt;
676	union sbi_pmu_ctr_info *info;
677	int lidx, hidx, fidx;
678	struct riscv_pmu *pmu;
679	struct perf_event *event;
680	unsigned long overflow;
681	unsigned long overflowed_ctrs = 0;
682	struct cpu_hw_events *cpu_hw_evt = dev;
683	u64 start_clock = sched_clock();
684
685	if (WARN_ON_ONCE(!cpu_hw_evt))
686		return IRQ_NONE;
687
688	/* Firmware counter don't support overflow yet */
689	fidx = find_first_bit(cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS);
690	if (fidx == RISCV_MAX_COUNTERS) {
691		csr_clear(CSR_SIP, BIT(riscv_pmu_irq_num));
692		return IRQ_NONE;
693	}
694
695	event = cpu_hw_evt->events[fidx];
696	if (!event) {
697		csr_clear(CSR_SIP, BIT(riscv_pmu_irq_num));
698		return IRQ_NONE;
699	}
700
701	pmu = to_riscv_pmu(event->pmu);
702	pmu_sbi_stop_hw_ctrs(pmu);
703
704	/* Overflow status register should only be read after counter are stopped */
705	ALT_SBI_PMU_OVERFLOW(overflow);
706
707	/*
708	 * Overflow interrupt pending bit should only be cleared after stopping
709	 * all the counters to avoid any race condition.
710	 */
711	csr_clear(CSR_SIP, BIT(riscv_pmu_irq_num));
712
713	/* No overflow bit is set */
714	if (!overflow)
715		return IRQ_NONE;
716
717	regs = get_irq_regs();
718
719	for_each_set_bit(lidx, cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS) {
720		struct perf_event *event = cpu_hw_evt->events[lidx];
721
722		/* Skip if invalid event or user did not request a sampling */
723		if (!event || !is_sampling_event(event))
724			continue;
725
726		info = &pmu_ctr_list[lidx];
727		/* Do a sanity check */
728		if (!info || info->type != SBI_PMU_CTR_TYPE_HW)
729			continue;
730
731		/* compute hardware counter index */
732		hidx = info->csr - CSR_CYCLE;
733		/* check if the corresponding bit is set in sscountovf */
734		if (!(overflow & BIT(hidx)))
735			continue;
736
737		/*
738		 * Keep a track of overflowed counters so that they can be started
739		 * with updated initial value.
740		 */
741		overflowed_ctrs |= BIT(lidx);
742		hw_evt = &event->hw;
743		riscv_pmu_event_update(event);
744		perf_sample_data_init(&data, 0, hw_evt->last_period);
745		if (riscv_pmu_event_set_period(event)) {
746			/*
747			 * Unlike other ISAs, RISC-V don't have to disable interrupts
748			 * to avoid throttling here. As per the specification, the
749			 * interrupt remains disabled until the OF bit is set.
750			 * Interrupts are enabled again only during the start.
751			 * TODO: We will need to stop the guest counters once
752			 * virtualization support is added.
753			 */
754			perf_event_overflow(event, &data, regs);
755		}
756	}
757
758	pmu_sbi_start_overflow_mask(pmu, overflowed_ctrs);
759	perf_sample_event_took(sched_clock() - start_clock);
760
761	return IRQ_HANDLED;
762}
763
764static int pmu_sbi_starting_cpu(unsigned int cpu, struct hlist_node *node)
765{
766	struct riscv_pmu *pmu = hlist_entry_safe(node, struct riscv_pmu, node);
767	struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
768
769	/*
770	 * We keep enabling userspace access to CYCLE, TIME and INSTRET via the
771	 * legacy option but that will be removed in the future.
772	 */
773	if (sysctl_perf_user_access == SYSCTL_LEGACY)
774		csr_write(CSR_SCOUNTEREN, 0x7);
775	else
776		csr_write(CSR_SCOUNTEREN, 0x2);
777
778	/* Stop all the counters so that they can be enabled from perf */
779	pmu_sbi_stop_all(pmu);
780
781	if (riscv_pmu_use_irq) {
782		cpu_hw_evt->irq = riscv_pmu_irq;
783		csr_clear(CSR_IP, BIT(riscv_pmu_irq_num));
784		csr_set(CSR_IE, BIT(riscv_pmu_irq_num));
785		enable_percpu_irq(riscv_pmu_irq, IRQ_TYPE_NONE);
786	}
787
788	return 0;
789}
790
791static int pmu_sbi_dying_cpu(unsigned int cpu, struct hlist_node *node)
792{
793	if (riscv_pmu_use_irq) {
794		disable_percpu_irq(riscv_pmu_irq);
795		csr_clear(CSR_IE, BIT(riscv_pmu_irq_num));
796	}
797
798	/* Disable all counters access for user mode now */
799	csr_write(CSR_SCOUNTEREN, 0x0);
800
801	return 0;
802}
803
804static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pdev)
805{
806	int ret;
807	struct cpu_hw_events __percpu *hw_events = pmu->hw_events;
808	struct irq_domain *domain = NULL;
809
810	if (riscv_isa_extension_available(NULL, SSCOFPMF)) {
811		riscv_pmu_irq_num = RV_IRQ_PMU;
812		riscv_pmu_use_irq = true;
813	} else if (IS_ENABLED(CONFIG_ERRATA_THEAD_PMU) &&
814		   riscv_cached_mvendorid(0) == THEAD_VENDOR_ID &&
815		   riscv_cached_marchid(0) == 0 &&
816		   riscv_cached_mimpid(0) == 0) {
817		riscv_pmu_irq_num = THEAD_C9XX_RV_IRQ_PMU;
818		riscv_pmu_use_irq = true;
819	}
820
821	if (!riscv_pmu_use_irq)
822		return -EOPNOTSUPP;
823
824	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
825					  DOMAIN_BUS_ANY);
826	if (!domain) {
827		pr_err("Failed to find INTC IRQ root domain\n");
828		return -ENODEV;
829	}
830
831	riscv_pmu_irq = irq_create_mapping(domain, riscv_pmu_irq_num);
832	if (!riscv_pmu_irq) {
833		pr_err("Failed to map PMU interrupt for node\n");
834		return -ENODEV;
835	}
836
837	ret = request_percpu_irq(riscv_pmu_irq, pmu_sbi_ovf_handler, "riscv-pmu", hw_events);
838	if (ret) {
839		pr_err("registering percpu irq failed [%d]\n", ret);
840		return ret;
841	}
842
843	return 0;
844}
845
846#ifdef CONFIG_CPU_PM
847static int riscv_pm_pmu_notify(struct notifier_block *b, unsigned long cmd,
848				void *v)
849{
850	struct riscv_pmu *rvpmu = container_of(b, struct riscv_pmu, riscv_pm_nb);
851	struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events);
852	int enabled = bitmap_weight(cpuc->used_hw_ctrs, RISCV_MAX_COUNTERS);
853	struct perf_event *event;
854	int idx;
855
856	if (!enabled)
857		return NOTIFY_OK;
858
859	for (idx = 0; idx < RISCV_MAX_COUNTERS; idx++) {
860		event = cpuc->events[idx];
861		if (!event)
862			continue;
863
864		switch (cmd) {
865		case CPU_PM_ENTER:
866			/*
867			 * Stop and update the counter
868			 */
869			riscv_pmu_stop(event, PERF_EF_UPDATE);
870			break;
871		case CPU_PM_EXIT:
872		case CPU_PM_ENTER_FAILED:
873			/*
874			 * Restore and enable the counter.
875			 */
876			riscv_pmu_start(event, PERF_EF_RELOAD);
877			break;
878		default:
879			break;
880		}
881	}
882
883	return NOTIFY_OK;
884}
885
886static int riscv_pm_pmu_register(struct riscv_pmu *pmu)
887{
888	pmu->riscv_pm_nb.notifier_call = riscv_pm_pmu_notify;
889	return cpu_pm_register_notifier(&pmu->riscv_pm_nb);
890}
891
892static void riscv_pm_pmu_unregister(struct riscv_pmu *pmu)
893{
894	cpu_pm_unregister_notifier(&pmu->riscv_pm_nb);
895}
896#else
897static inline int riscv_pm_pmu_register(struct riscv_pmu *pmu) { return 0; }
898static inline void riscv_pm_pmu_unregister(struct riscv_pmu *pmu) { }
899#endif
900
901static void riscv_pmu_destroy(struct riscv_pmu *pmu)
902{
903	riscv_pm_pmu_unregister(pmu);
904	cpuhp_state_remove_instance(CPUHP_AP_PERF_RISCV_STARTING, &pmu->node);
905}
906
907static void pmu_sbi_event_init(struct perf_event *event)
908{
909	/*
910	 * The permissions are set at event_init so that we do not depend
911	 * on the sysctl value that can change.
912	 */
913	if (sysctl_perf_user_access == SYSCTL_NO_USER_ACCESS)
914		event->hw.flags |= PERF_EVENT_FLAG_NO_USER_ACCESS;
915	else if (sysctl_perf_user_access == SYSCTL_USER_ACCESS)
916		event->hw.flags |= PERF_EVENT_FLAG_USER_ACCESS;
917	else
918		event->hw.flags |= PERF_EVENT_FLAG_LEGACY;
919}
920
921static void pmu_sbi_event_mapped(struct perf_event *event, struct mm_struct *mm)
922{
923	if (event->hw.flags & PERF_EVENT_FLAG_NO_USER_ACCESS)
924		return;
925
926	if (event->hw.flags & PERF_EVENT_FLAG_LEGACY) {
927		if (event->attr.config != PERF_COUNT_HW_CPU_CYCLES &&
928		    event->attr.config != PERF_COUNT_HW_INSTRUCTIONS) {
929			return;
930		}
931	}
932
933	/*
934	 * The user mmapped the event to directly access it: this is where
935	 * we determine based on sysctl_perf_user_access if we grant userspace
936	 * the direct access to this event. That means that within the same
937	 * task, some events may be directly accessible and some other may not,
938	 * if the user changes the value of sysctl_perf_user_accesss in the
939	 * meantime.
940	 */
941
942	event->hw.flags |= PERF_EVENT_FLAG_USER_READ_CNT;
943
944	/*
945	 * We must enable userspace access *before* advertising in the user page
946	 * that it is possible to do so to avoid any race.
947	 * And we must notify all cpus here because threads that currently run
948	 * on other cpus will try to directly access the counter too without
949	 * calling pmu_sbi_ctr_start.
950	 */
951	if (event->hw.flags & PERF_EVENT_FLAG_USER_ACCESS)
952		on_each_cpu_mask(mm_cpumask(mm),
953				 pmu_sbi_set_scounteren, (void *)event, 1);
954}
955
956static void pmu_sbi_event_unmapped(struct perf_event *event, struct mm_struct *mm)
957{
958	if (event->hw.flags & PERF_EVENT_FLAG_NO_USER_ACCESS)
959		return;
960
961	if (event->hw.flags & PERF_EVENT_FLAG_LEGACY) {
962		if (event->attr.config != PERF_COUNT_HW_CPU_CYCLES &&
963		    event->attr.config != PERF_COUNT_HW_INSTRUCTIONS) {
964			return;
965		}
966	}
967
968	/*
969	 * Here we can directly remove user access since the user does not have
970	 * access to the user page anymore so we avoid the racy window where the
971	 * user could have read cap_user_rdpmc to true right before we disable
972	 * it.
973	 */
974	event->hw.flags &= ~PERF_EVENT_FLAG_USER_READ_CNT;
975
976	if (event->hw.flags & PERF_EVENT_FLAG_USER_ACCESS)
977		on_each_cpu_mask(mm_cpumask(mm),
978				 pmu_sbi_reset_scounteren, (void *)event, 1);
979}
980
981static void riscv_pmu_update_counter_access(void *info)
982{
983	if (sysctl_perf_user_access == SYSCTL_LEGACY)
984		csr_write(CSR_SCOUNTEREN, 0x7);
985	else
986		csr_write(CSR_SCOUNTEREN, 0x2);
987}
988
989static int riscv_pmu_proc_user_access_handler(struct ctl_table *table,
990					      int write, void *buffer,
991					      size_t *lenp, loff_t *ppos)
992{
993	int prev = sysctl_perf_user_access;
994	int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
995
996	/*
997	 * Test against the previous value since we clear SCOUNTEREN when
998	 * sysctl_perf_user_access is set to SYSCTL_USER_ACCESS, but we should
999	 * not do that if that was already the case.
1000	 */
1001	if (ret || !write || prev == sysctl_perf_user_access)
1002		return ret;
1003
1004	on_each_cpu(riscv_pmu_update_counter_access, NULL, 1);
1005
1006	return 0;
1007}
1008
1009static struct ctl_table sbi_pmu_sysctl_table[] = {
1010	{
1011		.procname       = "perf_user_access",
1012		.data		= &sysctl_perf_user_access,
1013		.maxlen		= sizeof(unsigned int),
1014		.mode           = 0644,
1015		.proc_handler	= riscv_pmu_proc_user_access_handler,
1016		.extra1		= SYSCTL_ZERO,
1017		.extra2		= SYSCTL_TWO,
1018	},
1019	{ }
1020};
1021
1022static int pmu_sbi_device_probe(struct platform_device *pdev)
1023{
1024	struct riscv_pmu *pmu = NULL;
1025	int ret = -ENODEV;
1026	int num_counters;
1027
1028	pr_info("SBI PMU extension is available\n");
1029	pmu = riscv_pmu_alloc();
1030	if (!pmu)
1031		return -ENOMEM;
1032
1033	num_counters = pmu_sbi_find_num_ctrs();
1034	if (num_counters < 0) {
1035		pr_err("SBI PMU extension doesn't provide any counters\n");
1036		goto out_free;
1037	}
1038
1039	/* It is possible to get from SBI more than max number of counters */
1040	if (num_counters > RISCV_MAX_COUNTERS) {
1041		num_counters = RISCV_MAX_COUNTERS;
1042		pr_info("SBI returned more than maximum number of counters. Limiting the number of counters to %d\n", num_counters);
1043	}
1044
1045	/* cache all the information about counters now */
1046	if (pmu_sbi_get_ctrinfo(num_counters, &cmask))
1047		goto out_free;
1048
1049	ret = pmu_sbi_setup_irqs(pmu, pdev);
1050	if (ret < 0) {
1051		pr_info("Perf sampling/filtering is not supported as sscof extension is not available\n");
1052		pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
1053		pmu->pmu.capabilities |= PERF_PMU_CAP_NO_EXCLUDE;
1054	}
1055
1056	pmu->pmu.attr_groups = riscv_pmu_attr_groups;
1057	pmu->cmask = cmask;
1058	pmu->ctr_start = pmu_sbi_ctr_start;
1059	pmu->ctr_stop = pmu_sbi_ctr_stop;
1060	pmu->event_map = pmu_sbi_event_map;
1061	pmu->ctr_get_idx = pmu_sbi_ctr_get_idx;
1062	pmu->ctr_get_width = pmu_sbi_ctr_get_width;
1063	pmu->ctr_clear_idx = pmu_sbi_ctr_clear_idx;
1064	pmu->ctr_read = pmu_sbi_ctr_read;
1065	pmu->event_init = pmu_sbi_event_init;
1066	pmu->event_mapped = pmu_sbi_event_mapped;
1067	pmu->event_unmapped = pmu_sbi_event_unmapped;
1068	pmu->csr_index = pmu_sbi_csr_index;
1069
1070	ret = cpuhp_state_add_instance(CPUHP_AP_PERF_RISCV_STARTING, &pmu->node);
1071	if (ret)
1072		return ret;
1073
1074	ret = riscv_pm_pmu_register(pmu);
1075	if (ret)
1076		goto out_unregister;
1077
1078	ret = perf_pmu_register(&pmu->pmu, "cpu", PERF_TYPE_RAW);
1079	if (ret)
1080		goto out_unregister;
1081
1082	register_sysctl("kernel", sbi_pmu_sysctl_table);
1083
1084	return 0;
1085
1086out_unregister:
1087	riscv_pmu_destroy(pmu);
1088
1089out_free:
1090	kfree(pmu);
1091	return ret;
1092}
1093
1094static struct platform_driver pmu_sbi_driver = {
1095	.probe		= pmu_sbi_device_probe,
1096	.driver		= {
1097		.name	= RISCV_PMU_SBI_PDEV_NAME,
1098	},
1099};
1100
1101static int __init pmu_sbi_devinit(void)
1102{
1103	int ret;
1104	struct platform_device *pdev;
1105
1106	if (sbi_spec_version < sbi_mk_version(0, 3) ||
1107	    !sbi_probe_extension(SBI_EXT_PMU)) {
1108		return 0;
1109	}
1110
1111	ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_RISCV_STARTING,
1112				      "perf/riscv/pmu:starting",
1113				      pmu_sbi_starting_cpu, pmu_sbi_dying_cpu);
1114	if (ret) {
1115		pr_err("CPU hotplug notifier could not be registered: %d\n",
1116		       ret);
1117		return ret;
1118	}
1119
1120	ret = platform_driver_register(&pmu_sbi_driver);
1121	if (ret)
1122		return ret;
1123
1124	pdev = platform_device_register_simple(RISCV_PMU_SBI_PDEV_NAME, -1, NULL, 0);
1125	if (IS_ERR(pdev)) {
1126		platform_driver_unregister(&pmu_sbi_driver);
1127		return PTR_ERR(pdev);
1128	}
1129
1130	/* Notify legacy implementation that SBI pmu is available*/
1131	riscv_pmu_legacy_skip_init();
1132
1133	return ret;
1134}
1135device_initcall(pmu_sbi_devinit)
1136