xref: /linux/drivers/perf/riscv_pmu_sbi.c (revision f643f520c4c6998fa27dce90dd3b3ff6414e0bae)
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/perf/riscv_pmu.h>
14 #include <linux/platform_device.h>
15 #include <linux/irq.h>
16 #include <linux/irqdomain.h>
17 #include <linux/of_irq.h>
18 #include <linux/of.h>
19 #include <linux/cpu_pm.h>
20 #include <linux/sched/clock.h>
21 #include <linux/soc/andes/irq.h>
22 #include <linux/workqueue.h>
23 
24 #include <asm/errata_list.h>
25 #include <asm/sbi.h>
26 #include <asm/cpufeature.h>
27 #include <asm/vendor_extensions.h>
28 #include <asm/vendor_extensions/andes.h>
29 
30 #define ALT_SBI_PMU_OVERFLOW(__ovl)					\
31 asm volatile(ALTERNATIVE_2(						\
32 	"csrr %0, " __stringify(CSR_SCOUNTOVF),				\
33 	"csrr %0, " __stringify(THEAD_C9XX_CSR_SCOUNTEROF),		\
34 		THEAD_VENDOR_ID, ERRATA_THEAD_PMU,			\
35 		CONFIG_ERRATA_THEAD_PMU,				\
36 	"csrr %0, " __stringify(ANDES_CSR_SCOUNTEROF),			\
37 		ANDES_VENDOR_ID,					\
38 		RISCV_ISA_VENDOR_EXT_XANDESPMU + RISCV_VENDOR_EXT_ALTERNATIVES_BASE, \
39 		CONFIG_ANDES_CUSTOM_PMU)				\
40 	: "=r" (__ovl) :						\
41 	: "memory")
42 
43 #define ALT_SBI_PMU_OVF_CLEAR_PENDING(__irq_mask)			\
44 asm volatile(ALTERNATIVE(						\
45 	"csrc " __stringify(CSR_IP) ", %0\n\t",				\
46 	"csrc " __stringify(ANDES_CSR_SLIP) ", %0\n\t",			\
47 		ANDES_VENDOR_ID,					\
48 		RISCV_ISA_VENDOR_EXT_XANDESPMU + RISCV_VENDOR_EXT_ALTERNATIVES_BASE, \
49 		CONFIG_ANDES_CUSTOM_PMU)				\
50 	: : "r"(__irq_mask)						\
51 	: "memory")
52 
53 #define SYSCTL_NO_USER_ACCESS	0
54 #define SYSCTL_USER_ACCESS	1
55 #define SYSCTL_LEGACY		2
56 
57 #define PERF_EVENT_FLAG_NO_USER_ACCESS	BIT(SYSCTL_NO_USER_ACCESS)
58 #define PERF_EVENT_FLAG_USER_ACCESS	BIT(SYSCTL_USER_ACCESS)
59 #define PERF_EVENT_FLAG_LEGACY		BIT(SYSCTL_LEGACY)
60 
61 PMU_FORMAT_ATTR(event, "config:0-55");
62 PMU_FORMAT_ATTR(firmware, "config:62-63");
63 
64 static bool sbi_v2_available;
65 static bool sbi_v3_available;
66 static DEFINE_STATIC_KEY_FALSE(sbi_pmu_snapshot_available);
67 #define sbi_pmu_snapshot_available() \
68 	static_branch_unlikely(&sbi_pmu_snapshot_available)
69 
70 static struct attribute *riscv_arch_formats_attr[] = {
71 	&format_attr_event.attr,
72 	&format_attr_firmware.attr,
73 	NULL,
74 };
75 
76 static struct attribute_group riscv_pmu_format_group = {
77 	.name = "format",
78 	.attrs = riscv_arch_formats_attr,
79 };
80 
81 static const struct attribute_group *riscv_pmu_attr_groups[] = {
82 	&riscv_pmu_format_group,
83 	NULL,
84 };
85 
86 /* Allow user mode access by default */
87 static int sysctl_perf_user_access __read_mostly = SYSCTL_USER_ACCESS;
88 
89 /*
90  * RISC-V doesn't have heterogeneous harts yet. This need to be part of
91  * per_cpu in case of harts with different pmu counters
92  */
93 static union sbi_pmu_ctr_info *pmu_ctr_list;
94 static bool riscv_pmu_use_irq;
95 static unsigned int riscv_pmu_irq_num;
96 static unsigned int riscv_pmu_irq_mask;
97 static unsigned int riscv_pmu_irq;
98 
99 /* Cache the available counters in a bitmask */
100 static DECLARE_BITMAP(cmask, RISCV_MAX_COUNTERS);
101 
102 static int pmu_event_find_cache(u64 config);
103 struct sbi_pmu_event_data {
104 	union {
105 		union {
106 			struct hw_gen_event {
107 				uint32_t event_code:16;
108 				uint32_t event_type:4;
109 				uint32_t reserved:12;
110 			} hw_gen_event;
111 			struct hw_cache_event {
112 				uint32_t result_id:1;
113 				uint32_t op_id:2;
114 				uint32_t cache_id:13;
115 				uint32_t event_type:4;
116 				uint32_t reserved:12;
117 			} hw_cache_event;
118 		};
119 		uint32_t event_idx;
120 	};
121 };
122 
123 static struct sbi_pmu_event_data pmu_hw_event_map[] = {
124 	[PERF_COUNT_HW_CPU_CYCLES]		= {.hw_gen_event = {
125 							SBI_PMU_HW_CPU_CYCLES,
126 							SBI_PMU_EVENT_TYPE_HW, 0}},
127 	[PERF_COUNT_HW_INSTRUCTIONS]		= {.hw_gen_event = {
128 							SBI_PMU_HW_INSTRUCTIONS,
129 							SBI_PMU_EVENT_TYPE_HW, 0}},
130 	[PERF_COUNT_HW_CACHE_REFERENCES]	= {.hw_gen_event = {
131 							SBI_PMU_HW_CACHE_REFERENCES,
132 							SBI_PMU_EVENT_TYPE_HW, 0}},
133 	[PERF_COUNT_HW_CACHE_MISSES]		= {.hw_gen_event = {
134 							SBI_PMU_HW_CACHE_MISSES,
135 							SBI_PMU_EVENT_TYPE_HW, 0}},
136 	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= {.hw_gen_event = {
137 							SBI_PMU_HW_BRANCH_INSTRUCTIONS,
138 							SBI_PMU_EVENT_TYPE_HW, 0}},
139 	[PERF_COUNT_HW_BRANCH_MISSES]		= {.hw_gen_event = {
140 							SBI_PMU_HW_BRANCH_MISSES,
141 							SBI_PMU_EVENT_TYPE_HW, 0}},
142 	[PERF_COUNT_HW_BUS_CYCLES]		= {.hw_gen_event = {
143 							SBI_PMU_HW_BUS_CYCLES,
144 							SBI_PMU_EVENT_TYPE_HW, 0}},
145 	[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND]	= {.hw_gen_event = {
146 							SBI_PMU_HW_STALLED_CYCLES_FRONTEND,
147 							SBI_PMU_EVENT_TYPE_HW, 0}},
148 	[PERF_COUNT_HW_STALLED_CYCLES_BACKEND]	= {.hw_gen_event = {
149 							SBI_PMU_HW_STALLED_CYCLES_BACKEND,
150 							SBI_PMU_EVENT_TYPE_HW, 0}},
151 	[PERF_COUNT_HW_REF_CPU_CYCLES]		= {.hw_gen_event = {
152 							SBI_PMU_HW_REF_CPU_CYCLES,
153 							SBI_PMU_EVENT_TYPE_HW, 0}},
154 };
155 
156 #define C(x) PERF_COUNT_HW_CACHE_##x
157 static struct sbi_pmu_event_data pmu_cache_event_map[PERF_COUNT_HW_CACHE_MAX]
158 [PERF_COUNT_HW_CACHE_OP_MAX]
159 [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
160 	[C(L1D)] = {
161 		[C(OP_READ)] = {
162 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
163 					C(OP_READ), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
164 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
165 					C(OP_READ), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
166 		},
167 		[C(OP_WRITE)] = {
168 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
169 					C(OP_WRITE), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
170 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
171 					C(OP_WRITE), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
172 		},
173 		[C(OP_PREFETCH)] = {
174 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
175 					C(OP_PREFETCH), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
176 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
177 					C(OP_PREFETCH), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
178 		},
179 	},
180 	[C(L1I)] = {
181 		[C(OP_READ)] = {
182 			[C(RESULT_ACCESS)] = {.hw_cache_event =	{C(RESULT_ACCESS),
183 					C(OP_READ), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
184 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_READ),
185 					C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
186 		},
187 		[C(OP_WRITE)] = {
188 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
189 					C(OP_WRITE), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
190 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
191 					C(OP_WRITE), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
192 		},
193 		[C(OP_PREFETCH)] = {
194 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
195 					C(OP_PREFETCH), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
196 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
197 					C(OP_PREFETCH), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
198 		},
199 	},
200 	[C(LL)] = {
201 		[C(OP_READ)] = {
202 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
203 					C(OP_READ), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
204 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
205 					C(OP_READ), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
206 		},
207 		[C(OP_WRITE)] = {
208 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
209 					C(OP_WRITE), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
210 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
211 					C(OP_WRITE), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
212 		},
213 		[C(OP_PREFETCH)] = {
214 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
215 					C(OP_PREFETCH), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
216 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
217 					C(OP_PREFETCH), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
218 		},
219 	},
220 	[C(DTLB)] = {
221 		[C(OP_READ)] = {
222 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
223 					C(OP_READ), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
224 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
225 					C(OP_READ), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
226 		},
227 		[C(OP_WRITE)] = {
228 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
229 					C(OP_WRITE), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
230 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
231 					C(OP_WRITE), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
232 		},
233 		[C(OP_PREFETCH)] = {
234 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
235 					C(OP_PREFETCH), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
236 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
237 					C(OP_PREFETCH), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
238 		},
239 	},
240 	[C(ITLB)] = {
241 		[C(OP_READ)] = {
242 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
243 					C(OP_READ), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
244 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
245 					C(OP_READ), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
246 		},
247 		[C(OP_WRITE)] = {
248 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
249 					C(OP_WRITE), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
250 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
251 					C(OP_WRITE), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
252 		},
253 		[C(OP_PREFETCH)] = {
254 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
255 					C(OP_PREFETCH), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
256 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
257 					C(OP_PREFETCH), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
258 		},
259 	},
260 	[C(BPU)] = {
261 		[C(OP_READ)] = {
262 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
263 					C(OP_READ), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
264 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
265 					C(OP_READ), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
266 		},
267 		[C(OP_WRITE)] = {
268 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
269 					C(OP_WRITE), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
270 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
271 					C(OP_WRITE), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
272 		},
273 		[C(OP_PREFETCH)] = {
274 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
275 					C(OP_PREFETCH), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
276 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
277 					C(OP_PREFETCH), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
278 		},
279 	},
280 	[C(NODE)] = {
281 		[C(OP_READ)] = {
282 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
283 					C(OP_READ), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
284 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
285 					C(OP_READ), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
286 		},
287 		[C(OP_WRITE)] = {
288 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
289 					C(OP_WRITE), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
290 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
291 					C(OP_WRITE), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
292 		},
293 		[C(OP_PREFETCH)] = {
294 			[C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
295 					C(OP_PREFETCH), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
296 			[C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
297 					C(OP_PREFETCH), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
298 		},
299 	},
300 };
301 
302 static int pmu_sbi_check_event_info(void)
303 {
304 	int num_events = ARRAY_SIZE(pmu_hw_event_map) + PERF_COUNT_HW_CACHE_MAX *
305 			 PERF_COUNT_HW_CACHE_OP_MAX * PERF_COUNT_HW_CACHE_RESULT_MAX;
306 	struct riscv_pmu_event_info *event_info_shmem;
307 	phys_addr_t base_addr;
308 	int i, j, k, result = 0, count = 0;
309 	struct sbiret ret;
310 
311 	event_info_shmem = kzalloc_objs(*event_info_shmem, num_events);
312 	if (!event_info_shmem)
313 		return -ENOMEM;
314 
315 	for (i = 0; i < ARRAY_SIZE(pmu_hw_event_map); i++)
316 		event_info_shmem[count++].event_idx = pmu_hw_event_map[i].event_idx;
317 
318 	for (i = 0; i < ARRAY_SIZE(pmu_cache_event_map); i++) {
319 		for (j = 0; j < ARRAY_SIZE(pmu_cache_event_map[i]); j++) {
320 			for (k = 0; k < ARRAY_SIZE(pmu_cache_event_map[i][j]); k++)
321 				event_info_shmem[count++].event_idx =
322 							pmu_cache_event_map[i][j][k].event_idx;
323 		}
324 	}
325 
326 	base_addr = __pa(event_info_shmem);
327 	if (IS_ENABLED(CONFIG_32BIT))
328 		ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_EVENT_GET_INFO, lower_32_bits(base_addr),
329 				upper_32_bits(base_addr), count, 0, 0, 0);
330 	else
331 		ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_EVENT_GET_INFO, base_addr, 0,
332 				count, 0, 0, 0);
333 	if (ret.error) {
334 		result = -EOPNOTSUPP;
335 		goto free_mem;
336 	}
337 
338 	for (i = 0; i < ARRAY_SIZE(pmu_hw_event_map); i++) {
339 		if (!(event_info_shmem[i].output & RISCV_PMU_EVENT_INFO_OUTPUT_MASK))
340 			pmu_hw_event_map[i].event_idx = -ENOENT;
341 	}
342 
343 	count = ARRAY_SIZE(pmu_hw_event_map);
344 
345 	for (i = 0; i < ARRAY_SIZE(pmu_cache_event_map); i++) {
346 		for (j = 0; j < ARRAY_SIZE(pmu_cache_event_map[i]); j++) {
347 			for (k = 0; k < ARRAY_SIZE(pmu_cache_event_map[i][j]); k++) {
348 				if (!(event_info_shmem[count].output &
349 				      RISCV_PMU_EVENT_INFO_OUTPUT_MASK))
350 					pmu_cache_event_map[i][j][k].event_idx = -ENOENT;
351 				count++;
352 			}
353 		}
354 	}
355 
356 free_mem:
357 	kfree(event_info_shmem);
358 
359 	return result;
360 }
361 
362 static struct sbiret pmu_sbi_ctr_cfg_match(unsigned long cbase,
363 					   unsigned long ctr_mask,
364 					   unsigned long cflags,
365 					   unsigned long event_idx,
366 					   u64 config)
367 {
368 #if defined(CONFIG_32BIT)
369 	return sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase,
370 			 ctr_mask, cflags, event_idx, config, config >> 32);
371 #else
372 	return sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase,
373 			 ctr_mask, cflags, event_idx, config, 0);
374 #endif
375 }
376 
377 static void pmu_sbi_check_event(struct sbi_pmu_event_data *edata)
378 {
379 	struct sbiret ret = { .error = SBI_ERR_NOT_SUPPORTED };
380 	int i;
381 
382 	for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) {
383 		if (!cmask[i])
384 			continue;
385 		ret = pmu_sbi_ctr_cfg_match(i * BITS_PER_LONG, cmask[i], 0,
386 					    edata->event_idx, 0);
387 		if (!ret.error) {
388 			sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP,
389 				  ret.value, 0x1, SBI_PMU_STOP_FLAG_RESET, 0, 0, 0);
390 			return;
391 		}
392 	}
393 	if (ret.error == SBI_ERR_NOT_SUPPORTED) {
394 		/* This event cannot be monitored by any counter */
395 		edata->event_idx = -ENOENT;
396 	}
397 }
398 
399 static void pmu_sbi_check_std_events(struct work_struct *work)
400 {
401 	int ret;
402 
403 	if (sbi_v3_available) {
404 		ret = pmu_sbi_check_event_info();
405 		if (ret)
406 			pr_err("pmu_sbi_check_event_info failed with error %d\n", ret);
407 		return;
408 	}
409 
410 	for (int i = 0; i < ARRAY_SIZE(pmu_hw_event_map); i++)
411 		pmu_sbi_check_event(&pmu_hw_event_map[i]);
412 
413 	for (int i = 0; i < ARRAY_SIZE(pmu_cache_event_map); i++)
414 		for (int j = 0; j < ARRAY_SIZE(pmu_cache_event_map[i]); j++)
415 			for (int k = 0; k < ARRAY_SIZE(pmu_cache_event_map[i][j]); k++)
416 				pmu_sbi_check_event(&pmu_cache_event_map[i][j][k]);
417 }
418 
419 static DECLARE_WORK(check_std_events_work, pmu_sbi_check_std_events);
420 
421 static int pmu_sbi_ctr_get_width(int idx)
422 {
423 	return pmu_ctr_list[idx].width;
424 }
425 
426 static bool pmu_sbi_ctr_is_fw(int cidx)
427 {
428 	union sbi_pmu_ctr_info *info;
429 
430 	info = &pmu_ctr_list[cidx];
431 	if (!info)
432 		return false;
433 
434 	return info->type == SBI_PMU_CTR_TYPE_FW;
435 }
436 
437 int riscv_pmu_get_event_info(u32 type, u64 config, u64 *econfig)
438 {
439 	int ret = -ENOENT;
440 
441 	switch (type) {
442 	case PERF_TYPE_HARDWARE:
443 		if (config >= PERF_COUNT_HW_MAX)
444 			return -EINVAL;
445 		ret = pmu_hw_event_map[config].event_idx;
446 		break;
447 	case PERF_TYPE_HW_CACHE:
448 		ret = pmu_event_find_cache(config);
449 		break;
450 	case PERF_TYPE_RAW:
451 		/*
452 		 * As per SBI v0.3 specification,
453 		 *  -- the upper 16 bits must be unused for a hardware raw event.
454 		 * As per SBI v2.0 specification,
455 		 *  -- the upper 8 bits must be unused for a hardware raw event.
456 		 * Bits 63:62 are used to distinguish between raw events
457 		 * 00 - Hardware raw event
458 		 * 10 - SBI firmware events
459 		 * 11 - Risc-V platform specific firmware event
460 		 */
461 		switch (config >> 62) {
462 		case 0:
463 			if (sbi_v3_available) {
464 			/* Return error any bits [56-63] is set  as it is not allowed by the spec */
465 				if (!(config & ~RISCV_PMU_RAW_EVENT_V2_MASK)) {
466 					if (econfig)
467 						*econfig = config & RISCV_PMU_RAW_EVENT_V2_MASK;
468 					ret = RISCV_PMU_RAW_EVENT_V2_IDX;
469 				}
470 			/* Return error any bits [48-63] is set  as it is not allowed by the spec */
471 			} else if (!(config & ~RISCV_PMU_RAW_EVENT_MASK)) {
472 				if (econfig)
473 					*econfig = config & RISCV_PMU_RAW_EVENT_MASK;
474 				ret = RISCV_PMU_RAW_EVENT_IDX;
475 			}
476 			break;
477 		case 2:
478 			ret = (config & 0xFFFF) | (SBI_PMU_EVENT_TYPE_FW << 16);
479 			break;
480 		case 3:
481 			/*
482 			 * For Risc-V platform specific firmware events
483 			 * Event code - 0xFFFF
484 			 * Event data - raw event encoding
485 			 */
486 			ret = SBI_PMU_EVENT_TYPE_FW << 16 | RISCV_PLAT_FW_EVENT;
487 			if (econfig)
488 				*econfig = config & RISCV_PMU_PLAT_FW_EVENT_MASK;
489 			break;
490 		default:
491 			break;
492 		}
493 		break;
494 	default:
495 		break;
496 	}
497 
498 	return ret;
499 }
500 EXPORT_SYMBOL_GPL(riscv_pmu_get_event_info);
501 
502 /*
503  * Returns the counter width of a programmable counter and number of hardware
504  * counters. As we don't support heterogeneous CPUs yet, it is okay to just
505  * return the counter width of the first programmable counter.
506  */
507 int riscv_pmu_get_hpm_info(u32 *hw_ctr_width, u32 *num_hw_ctr)
508 {
509 	int i;
510 	union sbi_pmu_ctr_info *info;
511 	u32 hpm_width = 0, hpm_count = 0;
512 
513 	if (bitmap_empty(cmask, RISCV_MAX_COUNTERS))
514 		return -EINVAL;
515 
516 	for_each_set_bit(i, cmask, RISCV_MAX_COUNTERS) {
517 		info = &pmu_ctr_list[i];
518 		if (!info)
519 			continue;
520 		if (!hpm_width && info->csr != CSR_CYCLE && info->csr != CSR_INSTRET)
521 			hpm_width = info->width;
522 		if (info->type == SBI_PMU_CTR_TYPE_HW)
523 			hpm_count++;
524 	}
525 
526 	*hw_ctr_width = hpm_width;
527 	*num_hw_ctr = hpm_count;
528 
529 	return 0;
530 }
531 EXPORT_SYMBOL_GPL(riscv_pmu_get_hpm_info);
532 
533 static uint8_t pmu_sbi_csr_index(struct perf_event *event)
534 {
535 	return pmu_ctr_list[event->hw.idx].csr - CSR_CYCLE;
536 }
537 
538 static unsigned long pmu_sbi_get_filter_flags(struct perf_event *event)
539 {
540 	unsigned long cflags = 0;
541 	bool guest_events = false;
542 
543 	if (event->attr.config1 & RISCV_PMU_CONFIG1_GUEST_EVENTS)
544 		guest_events = true;
545 	if (event->attr.exclude_kernel)
546 		cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VSINH : SBI_PMU_CFG_FLAG_SET_SINH;
547 	if (event->attr.exclude_user)
548 		cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VUINH : SBI_PMU_CFG_FLAG_SET_UINH;
549 	if (guest_events && event->attr.exclude_hv)
550 		cflags |= SBI_PMU_CFG_FLAG_SET_SINH;
551 	if (event->attr.exclude_host)
552 		cflags |= SBI_PMU_CFG_FLAG_SET_UINH | SBI_PMU_CFG_FLAG_SET_SINH;
553 	if (event->attr.exclude_guest)
554 		cflags |= SBI_PMU_CFG_FLAG_SET_VSINH | SBI_PMU_CFG_FLAG_SET_VUINH;
555 
556 	return cflags;
557 }
558 
559 static int pmu_sbi_ctr_get_idx(struct perf_event *event)
560 {
561 	struct hw_perf_event *hwc = &event->hw;
562 	struct riscv_pmu *rvpmu = to_riscv_pmu(event->pmu);
563 	struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events);
564 	struct sbiret ret;
565 	int idx, i;
566 	u64 cbase = 0, cmask = 0;
567 	unsigned long cflags = 0;
568 
569 	cflags = pmu_sbi_get_filter_flags(event);
570 
571 	/*
572 	 * In legacy mode, we have to force the fixed counters for those events
573 	 * but not in the user access mode as we want to use the other counters
574 	 * that support sampling/filtering.
575 	 */
576 	if ((hwc->flags & PERF_EVENT_FLAG_LEGACY) && (event->attr.type == PERF_TYPE_HARDWARE)) {
577 		if (event->attr.config == PERF_COUNT_HW_CPU_CYCLES) {
578 			cflags |= SBI_PMU_CFG_FLAG_SKIP_MATCH;
579 			cmask = 1;
580 		} else if (event->attr.config == PERF_COUNT_HW_INSTRUCTIONS) {
581 			cflags |= SBI_PMU_CFG_FLAG_SKIP_MATCH;
582 			cmask = BIT(CSR_INSTRET - CSR_CYCLE);
583 		}
584 	}
585 
586 	/* retrieve the available counter index */
587 	if (cmask) {
588 		ret = pmu_sbi_ctr_cfg_match(cbase, cmask, cflags, hwc->event_base,
589 					    hwc->config);
590 	} else {
591 		ret.error = SBI_ERR_NOT_SUPPORTED;
592 		for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) {
593 			if (!rvpmu->cmask[i])
594 				continue;
595 			cbase = i * BITS_PER_LONG;
596 			ret = pmu_sbi_ctr_cfg_match(cbase, rvpmu->cmask[i], cflags,
597 						    hwc->event_base, hwc->config);
598 			if (!ret.error)
599 				break;
600 		}
601 	}
602 	if (ret.error) {
603 		pr_debug("Not able to find a counter for event %lx config %llx\n",
604 			hwc->event_base, hwc->config);
605 		return sbi_err_map_linux_errno(ret.error);
606 	}
607 
608 	idx = ret.value;
609 	if (!test_bit(idx, rvpmu->cmask) || !pmu_ctr_list[idx].value)
610 		return -ENOENT;
611 
612 	/* Additional sanity check for the counter id */
613 	if (pmu_sbi_ctr_is_fw(idx)) {
614 		if (!test_and_set_bit(idx, cpuc->used_fw_ctrs))
615 			return idx;
616 	} else {
617 		if (!test_and_set_bit(idx, cpuc->used_hw_ctrs))
618 			return idx;
619 	}
620 
621 	return -ENOENT;
622 }
623 
624 static void pmu_sbi_ctr_clear_idx(struct perf_event *event)
625 {
626 
627 	struct hw_perf_event *hwc = &event->hw;
628 	struct riscv_pmu *rvpmu = to_riscv_pmu(event->pmu);
629 	struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events);
630 	int idx = hwc->idx;
631 
632 	if (pmu_sbi_ctr_is_fw(idx))
633 		clear_bit(idx, cpuc->used_fw_ctrs);
634 	else
635 		clear_bit(idx, cpuc->used_hw_ctrs);
636 }
637 
638 static int pmu_event_find_cache(u64 config)
639 {
640 	unsigned int cache_type, cache_op, cache_result, ret;
641 
642 	cache_type = (config >>  0) & 0xff;
643 	if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
644 		return -EINVAL;
645 
646 	cache_op = (config >>  8) & 0xff;
647 	if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
648 		return -EINVAL;
649 
650 	cache_result = (config >> 16) & 0xff;
651 	if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
652 		return -EINVAL;
653 
654 	ret = pmu_cache_event_map[cache_type][cache_op][cache_result].event_idx;
655 
656 	return ret;
657 }
658 
659 static bool pmu_sbi_is_fw_event(struct perf_event *event)
660 {
661 	u32 type = event->attr.type;
662 	u64 config = event->attr.config;
663 
664 	if ((type == PERF_TYPE_RAW) && ((config >> 63) == 1))
665 		return true;
666 	else
667 		return false;
668 }
669 
670 static int pmu_sbi_event_map(struct perf_event *event, u64 *econfig)
671 {
672 	u32 type = event->attr.type;
673 	u64 config = event->attr.config;
674 
675 	/*
676 	 * Ensure we are finished checking standard hardware events for
677 	 * validity before allowing userspace to configure any events.
678 	 */
679 	flush_work(&check_std_events_work);
680 
681 	return riscv_pmu_get_event_info(type, config, econfig);
682 }
683 
684 static void pmu_sbi_snapshot_free(struct riscv_pmu *pmu)
685 {
686 	int cpu;
687 
688 	for_each_possible_cpu(cpu) {
689 		struct cpu_hw_events *cpu_hw_evt = per_cpu_ptr(pmu->hw_events, cpu);
690 
691 		if (!cpu_hw_evt->snapshot_addr)
692 			continue;
693 
694 		free_page((unsigned long)cpu_hw_evt->snapshot_addr);
695 		cpu_hw_evt->snapshot_addr = NULL;
696 		cpu_hw_evt->snapshot_addr_phys = 0;
697 	}
698 }
699 
700 static int pmu_sbi_snapshot_alloc(struct riscv_pmu *pmu)
701 {
702 	int cpu;
703 	struct page *snapshot_page;
704 
705 	for_each_possible_cpu(cpu) {
706 		struct cpu_hw_events *cpu_hw_evt = per_cpu_ptr(pmu->hw_events, cpu);
707 
708 		snapshot_page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
709 		if (!snapshot_page) {
710 			pmu_sbi_snapshot_free(pmu);
711 			return -ENOMEM;
712 		}
713 		cpu_hw_evt->snapshot_addr = page_to_virt(snapshot_page);
714 		cpu_hw_evt->snapshot_addr_phys = page_to_phys(snapshot_page);
715 	}
716 
717 	return 0;
718 }
719 
720 static int pmu_sbi_snapshot_disable(void)
721 {
722 	struct sbiret ret;
723 
724 	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_SNAPSHOT_SET_SHMEM, SBI_SHMEM_DISABLE,
725 			SBI_SHMEM_DISABLE, 0, 0, 0, 0);
726 	if (ret.error) {
727 		pr_warn("failed to disable snapshot shared memory\n");
728 		return sbi_err_map_linux_errno(ret.error);
729 	}
730 
731 	return 0;
732 }
733 
734 static int pmu_sbi_snapshot_setup(struct riscv_pmu *pmu, int cpu)
735 {
736 	struct cpu_hw_events *cpu_hw_evt;
737 	struct sbiret ret = {0};
738 
739 	cpu_hw_evt = per_cpu_ptr(pmu->hw_events, cpu);
740 	if (!cpu_hw_evt->snapshot_addr_phys)
741 		return -EINVAL;
742 
743 	if (cpu_hw_evt->snapshot_set_done)
744 		return 0;
745 
746 	if (IS_ENABLED(CONFIG_32BIT))
747 		ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_SNAPSHOT_SET_SHMEM,
748 				cpu_hw_evt->snapshot_addr_phys,
749 				(u64)(cpu_hw_evt->snapshot_addr_phys) >> 32, 0, 0, 0, 0);
750 	else
751 		ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_SNAPSHOT_SET_SHMEM,
752 				cpu_hw_evt->snapshot_addr_phys, 0, 0, 0, 0, 0);
753 
754 	/* Free up the snapshot area memory and fall back to SBI PMU calls without snapshot */
755 	if (ret.error) {
756 		if (ret.error != SBI_ERR_NOT_SUPPORTED)
757 			pr_warn("pmu snapshot setup failed with error %ld\n", ret.error);
758 		return sbi_err_map_linux_errno(ret.error);
759 	}
760 
761 	memset(cpu_hw_evt->snapshot_cval_shcopy, 0, sizeof(u64) * RISCV_MAX_COUNTERS);
762 	cpu_hw_evt->snapshot_set_done = true;
763 
764 	return 0;
765 }
766 
767 static u64 pmu_sbi_ctr_read(struct perf_event *event)
768 {
769 	struct hw_perf_event *hwc = &event->hw;
770 	int idx = hwc->idx;
771 	struct sbiret ret;
772 	u64 val = 0;
773 	struct riscv_pmu *pmu = to_riscv_pmu(event->pmu);
774 	struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
775 	struct riscv_pmu_snapshot_data *sdata = cpu_hw_evt->snapshot_addr;
776 	union sbi_pmu_ctr_info info = pmu_ctr_list[idx];
777 
778 	/* Read the value from the shared memory directly only if counter is stopped */
779 	if (sbi_pmu_snapshot_available() && (hwc->state & PERF_HES_STOPPED)) {
780 		val = sdata->ctr_values[idx];
781 		return val;
782 	}
783 
784 	if (pmu_sbi_is_fw_event(event)) {
785 		ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_FW_READ,
786 				hwc->idx, 0, 0, 0, 0, 0);
787 		if (ret.error)
788 			return 0;
789 
790 		val = ret.value;
791 		if (IS_ENABLED(CONFIG_32BIT) && sbi_v2_available && info.width >= 32) {
792 			ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_FW_READ_HI,
793 					hwc->idx, 0, 0, 0, 0, 0);
794 			if (!ret.error)
795 				val |= ((u64)ret.value << 32);
796 			else
797 				WARN_ONCE(1, "Unable to read upper 32 bits of firmware counter error: %ld\n",
798 					  ret.error);
799 		}
800 	} else {
801 		val = riscv_pmu_ctr_read_csr(info.csr);
802 		if (IS_ENABLED(CONFIG_32BIT))
803 			val |= ((u64)riscv_pmu_ctr_read_csr(info.csr + 0x80)) << 32;
804 	}
805 
806 	return val;
807 }
808 
809 static void pmu_sbi_set_scounteren(void *arg)
810 {
811 	struct perf_event *event = (struct perf_event *)arg;
812 
813 	if (event->hw.idx != -1)
814 		csr_write(CSR_SCOUNTEREN,
815 			  csr_read(CSR_SCOUNTEREN) | BIT(pmu_sbi_csr_index(event)));
816 }
817 
818 static void pmu_sbi_reset_scounteren(void *arg)
819 {
820 	struct perf_event *event = (struct perf_event *)arg;
821 
822 	if (event->hw.idx != -1)
823 		csr_write(CSR_SCOUNTEREN,
824 			  csr_read(CSR_SCOUNTEREN) & ~BIT(pmu_sbi_csr_index(event)));
825 }
826 
827 static void pmu_sbi_ctr_start(struct perf_event *event, u64 ival)
828 {
829 	struct sbiret ret;
830 	struct hw_perf_event *hwc = &event->hw;
831 	unsigned long flag = SBI_PMU_START_FLAG_SET_INIT_VALUE;
832 
833 	/* There is no benefit setting SNAPSHOT FLAG for a single counter */
834 #if defined(CONFIG_32BIT)
835 	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, hwc->idx,
836 			1, flag, ival, ival >> 32, 0);
837 #else
838 	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, hwc->idx,
839 			1, flag, ival, 0, 0);
840 #endif
841 	if (ret.error && (ret.error != SBI_ERR_ALREADY_STARTED))
842 		pr_err("Starting counter idx %d failed with error %d\n",
843 			hwc->idx, sbi_err_map_linux_errno(ret.error));
844 
845 	if ((hwc->flags & PERF_EVENT_FLAG_USER_ACCESS) &&
846 	    (hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT))
847 		pmu_sbi_set_scounteren((void *)event);
848 }
849 
850 static void pmu_sbi_ctr_stop(struct perf_event *event, unsigned long flag)
851 {
852 	struct sbiret ret;
853 	struct hw_perf_event *hwc = &event->hw;
854 	struct riscv_pmu *pmu = to_riscv_pmu(event->pmu);
855 	struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
856 	struct riscv_pmu_snapshot_data *sdata = cpu_hw_evt->snapshot_addr;
857 
858 	if ((hwc->flags & PERF_EVENT_FLAG_USER_ACCESS) &&
859 	    (hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT))
860 		pmu_sbi_reset_scounteren((void *)event);
861 
862 	if (sbi_pmu_snapshot_available())
863 		flag |= SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT;
864 
865 	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, hwc->idx, 1, flag, 0, 0, 0);
866 	if (!ret.error && sbi_pmu_snapshot_available()) {
867 		/*
868 		 * The counter snapshot is based on the index base specified by hwc->idx.
869 		 * The actual counter value is updated in shared memory at index 0 when counter
870 		 * mask is 0x01. To ensure accurate counter values, it's necessary to transfer
871 		 * the counter value to shared memory. However, if hwc->idx is zero, the counter
872 		 * value is already correctly updated in shared memory, requiring no further
873 		 * adjustment.
874 		 */
875 		if (hwc->idx > 0) {
876 			sdata->ctr_values[hwc->idx] = sdata->ctr_values[0];
877 			sdata->ctr_values[0] = 0;
878 		}
879 	} else if (ret.error && (ret.error != SBI_ERR_ALREADY_STOPPED) &&
880 		flag != SBI_PMU_STOP_FLAG_RESET) {
881 		pr_err("Stopping counter idx %d failed with error %d\n",
882 			hwc->idx, sbi_err_map_linux_errno(ret.error));
883 	}
884 }
885 
886 static int pmu_sbi_find_num_ctrs(void)
887 {
888 	struct sbiret ret;
889 
890 	ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_NUM_COUNTERS, 0, 0, 0, 0, 0, 0);
891 	if (!ret.error)
892 		return ret.value;
893 	else
894 		return sbi_err_map_linux_errno(ret.error);
895 }
896 
897 static int pmu_sbi_get_ctrinfo(int nctr, unsigned long *mask)
898 {
899 	struct sbiret ret;
900 	int i, num_hw_ctr = 0, num_fw_ctr = 0;
901 	union sbi_pmu_ctr_info cinfo;
902 
903 	pmu_ctr_list = kzalloc_objs(*pmu_ctr_list, nctr);
904 	if (!pmu_ctr_list)
905 		return -ENOMEM;
906 
907 	for (i = 0; i < nctr; i++) {
908 		ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_GET_INFO, i, 0, 0, 0, 0, 0);
909 		if (ret.error)
910 			/* The logical counter ids are not expected to be contiguous */
911 			continue;
912 
913 		set_bit(i, mask);
914 
915 		cinfo.value = ret.value;
916 		if (cinfo.type == SBI_PMU_CTR_TYPE_FW)
917 			num_fw_ctr++;
918 		else
919 			num_hw_ctr++;
920 		pmu_ctr_list[i].value = cinfo.value;
921 	}
922 
923 	pr_info("%d firmware and %d hardware counters\n", num_fw_ctr, num_hw_ctr);
924 
925 	return 0;
926 }
927 
928 static inline void pmu_sbi_stop_all(struct riscv_pmu *pmu)
929 {
930 	int i;
931 
932 	/*
933 	 * No need to check the error because we are disabling all the counters
934 	 * which may include counters that are not enabled yet.
935 	 */
936 	for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) {
937 		if (!pmu->cmask[i])
938 			continue;
939 		sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP,
940 			  i * BITS_PER_LONG, pmu->cmask[i],
941 			  SBI_PMU_STOP_FLAG_RESET, 0, 0, 0);
942 	}
943 }
944 
945 static inline void pmu_sbi_stop_hw_ctrs(struct riscv_pmu *pmu)
946 {
947 	struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
948 	struct riscv_pmu_snapshot_data *sdata = cpu_hw_evt->snapshot_addr;
949 	unsigned long flag = 0;
950 	int i, idx;
951 	struct sbiret ret;
952 	u64 temp_ctr_overflow_mask = 0;
953 
954 	if (sbi_pmu_snapshot_available())
955 		flag = SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT;
956 
957 	/* Reset the shadow copy to avoid save/restore any value from previous overflow */
958 	memset(cpu_hw_evt->snapshot_cval_shcopy, 0, sizeof(u64) * RISCV_MAX_COUNTERS);
959 
960 	for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) {
961 		/* No need to check the error here as we can't do anything about the error */
962 		ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, i * BITS_PER_LONG,
963 				cpu_hw_evt->used_hw_ctrs[i], flag, 0, 0, 0);
964 		if (!ret.error && sbi_pmu_snapshot_available()) {
965 			/* Save the counter values to avoid clobbering */
966 			for_each_set_bit(idx, &cpu_hw_evt->used_hw_ctrs[i], BITS_PER_LONG)
967 				cpu_hw_evt->snapshot_cval_shcopy[i * BITS_PER_LONG + idx] =
968 							sdata->ctr_values[idx];
969 			/* Save the overflow mask to avoid clobbering */
970 			temp_ctr_overflow_mask |= sdata->ctr_overflow_mask << (i * BITS_PER_LONG);
971 		}
972 	}
973 
974 	/* Restore the counter values to the shared memory for used hw counters */
975 	if (sbi_pmu_snapshot_available()) {
976 		for_each_set_bit(idx, cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS)
977 			sdata->ctr_values[idx] = cpu_hw_evt->snapshot_cval_shcopy[idx];
978 		if (temp_ctr_overflow_mask)
979 			sdata->ctr_overflow_mask = temp_ctr_overflow_mask;
980 	}
981 }
982 
983 /*
984  * This function starts all the used counters in two step approach.
985  * Any counter that did not overflow can be start in a single step
986  * while the overflowed counters need to be started with updated initialization
987  * value.
988  */
989 static inline void pmu_sbi_start_ovf_ctrs_sbi(struct cpu_hw_events *cpu_hw_evt,
990 					      u64 ctr_ovf_mask)
991 {
992 	int idx = 0, i;
993 	struct perf_event *event;
994 	unsigned long flag = SBI_PMU_START_FLAG_SET_INIT_VALUE;
995 	unsigned long ctr_start_mask = 0;
996 	uint64_t max_period;
997 	struct hw_perf_event *hwc;
998 	u64 init_val = 0;
999 
1000 	for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) {
1001 		ctr_start_mask = cpu_hw_evt->used_hw_ctrs[i] & ~ctr_ovf_mask;
1002 		/* Start all the counters that did not overflow in a single shot */
1003 		if (ctr_start_mask) {
1004 			sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, i * BITS_PER_LONG,
1005 				  ctr_start_mask, 0, 0, 0, 0);
1006 		}
1007 	}
1008 
1009 	/* Reinitialize and start all the counter that overflowed */
1010 	while (ctr_ovf_mask) {
1011 		if (ctr_ovf_mask & 0x01) {
1012 			event = cpu_hw_evt->events[idx];
1013 			hwc = &event->hw;
1014 			max_period = riscv_pmu_ctr_get_width_mask(event);
1015 			init_val = local64_read(&hwc->prev_count) & max_period;
1016 #if defined(CONFIG_32BIT)
1017 			sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx, 1,
1018 				  flag, init_val, init_val >> 32, 0);
1019 #else
1020 			sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx, 1,
1021 				  flag, init_val, 0, 0);
1022 #endif
1023 			perf_event_update_userpage(event);
1024 		}
1025 		ctr_ovf_mask = ctr_ovf_mask >> 1;
1026 		idx++;
1027 	}
1028 }
1029 
1030 static inline void pmu_sbi_start_ovf_ctrs_snapshot(struct cpu_hw_events *cpu_hw_evt,
1031 						   u64 ctr_ovf_mask)
1032 {
1033 	int i, idx = 0;
1034 	struct perf_event *event;
1035 	unsigned long flag = SBI_PMU_START_FLAG_INIT_SNAPSHOT;
1036 	u64 max_period, init_val = 0;
1037 	struct hw_perf_event *hwc;
1038 	struct riscv_pmu_snapshot_data *sdata = cpu_hw_evt->snapshot_addr;
1039 
1040 	for_each_set_bit(idx, cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS) {
1041 		if (ctr_ovf_mask & BIT_ULL(idx)) {
1042 			event = cpu_hw_evt->events[idx];
1043 			hwc = &event->hw;
1044 			max_period = riscv_pmu_ctr_get_width_mask(event);
1045 			init_val = local64_read(&hwc->prev_count) & max_period;
1046 			cpu_hw_evt->snapshot_cval_shcopy[idx] = init_val;
1047 		}
1048 		/*
1049 		 * We do not need to update the non-overflow counters the previous
1050 		 * value should have been there already.
1051 		 */
1052 	}
1053 
1054 	for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) {
1055 		/* Restore the counter values to relative indices for used hw counters */
1056 		for_each_set_bit(idx, &cpu_hw_evt->used_hw_ctrs[i], BITS_PER_LONG)
1057 			sdata->ctr_values[idx] =
1058 					cpu_hw_evt->snapshot_cval_shcopy[idx + i * BITS_PER_LONG];
1059 		/* Start all the counters in a single shot */
1060 		sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx * BITS_PER_LONG,
1061 			  cpu_hw_evt->used_hw_ctrs[i], flag, 0, 0, 0);
1062 	}
1063 }
1064 
1065 static void pmu_sbi_start_overflow_mask(struct riscv_pmu *pmu,
1066 					u64 ctr_ovf_mask)
1067 {
1068 	struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
1069 
1070 	if (sbi_pmu_snapshot_available())
1071 		pmu_sbi_start_ovf_ctrs_snapshot(cpu_hw_evt, ctr_ovf_mask);
1072 	else
1073 		pmu_sbi_start_ovf_ctrs_sbi(cpu_hw_evt, ctr_ovf_mask);
1074 }
1075 
1076 static irqreturn_t pmu_sbi_ovf_handler(int irq, void *dev)
1077 {
1078 	struct perf_sample_data data;
1079 	struct pt_regs *regs;
1080 	struct hw_perf_event *hw_evt;
1081 	union sbi_pmu_ctr_info *info;
1082 	int lidx, hidx, fidx;
1083 	struct riscv_pmu *pmu;
1084 	struct perf_event *event;
1085 	u64 overflow;
1086 	u64 overflowed_ctrs = 0;
1087 	struct cpu_hw_events *cpu_hw_evt = dev;
1088 	u64 start_clock = sched_clock();
1089 	struct riscv_pmu_snapshot_data *sdata;
1090 
1091 	if (WARN_ON_ONCE(!cpu_hw_evt))
1092 		return IRQ_NONE;
1093 
1094 	sdata = cpu_hw_evt->snapshot_addr;
1095 
1096 	/* Firmware counter don't support overflow yet */
1097 	fidx = find_first_bit(cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS);
1098 	if (fidx == RISCV_MAX_COUNTERS) {
1099 		csr_clear(CSR_SIP, BIT(riscv_pmu_irq_num));
1100 		return IRQ_NONE;
1101 	}
1102 
1103 	event = cpu_hw_evt->events[fidx];
1104 	if (!event) {
1105 		ALT_SBI_PMU_OVF_CLEAR_PENDING(riscv_pmu_irq_mask);
1106 		return IRQ_NONE;
1107 	}
1108 
1109 	pmu = to_riscv_pmu(event->pmu);
1110 	pmu_sbi_stop_hw_ctrs(pmu);
1111 
1112 	/* Overflow status register should only be read after counter are stopped */
1113 	if (sbi_pmu_snapshot_available())
1114 		overflow = sdata->ctr_overflow_mask;
1115 	else
1116 		ALT_SBI_PMU_OVERFLOW(overflow);
1117 
1118 	/*
1119 	 * Overflow interrupt pending bit should only be cleared after stopping
1120 	 * all the counters to avoid any race condition.
1121 	 */
1122 	ALT_SBI_PMU_OVF_CLEAR_PENDING(riscv_pmu_irq_mask);
1123 
1124 	/* No overflow bit is set */
1125 	if (!overflow)
1126 		return IRQ_NONE;
1127 
1128 	regs = get_irq_regs();
1129 
1130 	for_each_set_bit(lidx, cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS) {
1131 		struct perf_event *event = cpu_hw_evt->events[lidx];
1132 
1133 		/* Skip if invalid event or user did not request a sampling */
1134 		if (!event || !is_sampling_event(event))
1135 			continue;
1136 
1137 		info = &pmu_ctr_list[lidx];
1138 		/* Do a sanity check */
1139 		if (!info || info->type != SBI_PMU_CTR_TYPE_HW)
1140 			continue;
1141 
1142 		if (sbi_pmu_snapshot_available())
1143 			/* SBI implementation already updated the logical indicies */
1144 			hidx = lidx;
1145 		else
1146 			/* compute hardware counter index */
1147 			hidx = info->csr - CSR_CYCLE;
1148 
1149 		/* check if the corresponding bit is set in scountovf or overflow mask in shmem */
1150 		if (!(overflow & BIT_ULL(hidx)))
1151 			continue;
1152 
1153 		/*
1154 		 * Keep a track of overflowed counters so that they can be started
1155 		 * with updated initial value.
1156 		 */
1157 		overflowed_ctrs |= BIT_ULL(lidx);
1158 		hw_evt = &event->hw;
1159 		/* Update the event states here so that we know the state while reading */
1160 		hw_evt->state |= PERF_HES_STOPPED;
1161 		riscv_pmu_event_update(event);
1162 		hw_evt->state |= PERF_HES_UPTODATE;
1163 		perf_sample_data_init(&data, 0, hw_evt->last_period);
1164 		if (riscv_pmu_event_set_period(event)) {
1165 			/*
1166 			 * Unlike other ISAs, RISC-V don't have to disable interrupts
1167 			 * to avoid throttling here. As per the specification, the
1168 			 * interrupt remains disabled until the OF bit is set.
1169 			 * Interrupts are enabled again only during the start.
1170 			 * TODO: We will need to stop the guest counters once
1171 			 * virtualization support is added.
1172 			 */
1173 			perf_event_overflow(event, &data, regs);
1174 		}
1175 		/* Reset the state as we are going to start the counter after the loop */
1176 		hw_evt->state = 0;
1177 	}
1178 
1179 	pmu_sbi_start_overflow_mask(pmu, overflowed_ctrs);
1180 	perf_sample_event_took(sched_clock() - start_clock);
1181 
1182 	return IRQ_HANDLED;
1183 }
1184 
1185 static int pmu_sbi_starting_cpu(unsigned int cpu, struct hlist_node *node)
1186 {
1187 	struct riscv_pmu *pmu = hlist_entry_safe(node, struct riscv_pmu, node);
1188 	struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
1189 
1190 	/*
1191 	 * We keep enabling userspace access to CYCLE, TIME and INSTRET via the
1192 	 * legacy option but that will be removed in the future.
1193 	 */
1194 	if (sysctl_perf_user_access == SYSCTL_LEGACY)
1195 		csr_write(CSR_SCOUNTEREN, 0x7);
1196 	else
1197 		csr_write(CSR_SCOUNTEREN, 0x2);
1198 
1199 	/* Stop all the counters so that they can be enabled from perf */
1200 	pmu_sbi_stop_all(pmu);
1201 
1202 	if (riscv_pmu_use_irq) {
1203 		cpu_hw_evt->irq = riscv_pmu_irq;
1204 		ALT_SBI_PMU_OVF_CLEAR_PENDING(riscv_pmu_irq_mask);
1205 		enable_percpu_irq(riscv_pmu_irq, IRQ_TYPE_NONE);
1206 	}
1207 
1208 	if (sbi_pmu_snapshot_available())
1209 		return pmu_sbi_snapshot_setup(pmu, cpu);
1210 
1211 	return 0;
1212 }
1213 
1214 static int pmu_sbi_dying_cpu(unsigned int cpu, struct hlist_node *node)
1215 {
1216 	if (riscv_pmu_use_irq) {
1217 		disable_percpu_irq(riscv_pmu_irq);
1218 	}
1219 
1220 	/* Disable all counters access for user mode now */
1221 	csr_write(CSR_SCOUNTEREN, 0x0);
1222 
1223 	if (sbi_pmu_snapshot_available())
1224 		return pmu_sbi_snapshot_disable();
1225 
1226 	return 0;
1227 }
1228 
1229 static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pdev)
1230 {
1231 	int ret;
1232 	struct cpu_hw_events __percpu *hw_events = pmu->hw_events;
1233 	struct irq_domain *domain = NULL;
1234 
1235 	if (riscv_isa_extension_available(NULL, SSCOFPMF)) {
1236 		riscv_pmu_irq_num = RV_IRQ_PMU;
1237 		riscv_pmu_use_irq = true;
1238 	} else if (IS_ENABLED(CONFIG_ERRATA_THEAD_PMU) &&
1239 		   riscv_cached_mvendorid(0) == THEAD_VENDOR_ID &&
1240 		   riscv_cached_marchid(0) == 0 &&
1241 		   riscv_cached_mimpid(0) == 0) {
1242 		riscv_pmu_irq_num = THEAD_C9XX_RV_IRQ_PMU;
1243 		riscv_pmu_use_irq = true;
1244 	} else if (riscv_has_vendor_extension_unlikely(ANDES_VENDOR_ID,
1245 						       RISCV_ISA_VENDOR_EXT_XANDESPMU) &&
1246 		   IS_ENABLED(CONFIG_ANDES_CUSTOM_PMU)) {
1247 		riscv_pmu_irq_num = ANDES_SLI_CAUSE_BASE + ANDES_RV_IRQ_PMOVI;
1248 		riscv_pmu_use_irq = true;
1249 	}
1250 
1251 	riscv_pmu_irq_mask = BIT(riscv_pmu_irq_num % BITS_PER_LONG);
1252 
1253 	if (!riscv_pmu_use_irq)
1254 		return -EOPNOTSUPP;
1255 
1256 	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
1257 					  DOMAIN_BUS_ANY);
1258 	if (!domain) {
1259 		pr_err("Failed to find INTC IRQ root domain\n");
1260 		ret = -ENODEV;
1261 		goto err;
1262 	}
1263 
1264 	riscv_pmu_irq = irq_create_mapping(domain, riscv_pmu_irq_num);
1265 	if (!riscv_pmu_irq) {
1266 		pr_err("Failed to map PMU interrupt for node\n");
1267 		ret = -ENODEV;
1268 		goto err;
1269 	}
1270 
1271 	ret = request_percpu_irq(riscv_pmu_irq, pmu_sbi_ovf_handler, "riscv-pmu", hw_events);
1272 	if (ret) {
1273 		pr_err("registering percpu irq failed [%d]\n", ret);
1274 		irq_dispose_mapping(riscv_pmu_irq);
1275 		riscv_pmu_irq = 0;
1276 		goto err;
1277 	}
1278 
1279 	return 0;
1280 err:
1281 	riscv_pmu_use_irq = false;
1282 	return ret;
1283 }
1284 
1285 #ifdef CONFIG_CPU_PM
1286 static int riscv_pm_pmu_notify(struct notifier_block *b, unsigned long cmd,
1287 				void *v)
1288 {
1289 	struct riscv_pmu *rvpmu = container_of(b, struct riscv_pmu, riscv_pm_nb);
1290 	struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events);
1291 	bool enabled = !bitmap_empty(cpuc->used_hw_ctrs, RISCV_MAX_COUNTERS);
1292 	struct perf_event *event;
1293 	int idx;
1294 
1295 	if (!enabled)
1296 		return NOTIFY_OK;
1297 
1298 	for (idx = 0; idx < RISCV_MAX_COUNTERS; idx++) {
1299 		event = cpuc->events[idx];
1300 		if (!event)
1301 			continue;
1302 
1303 		switch (cmd) {
1304 		case CPU_PM_ENTER:
1305 			/*
1306 			 * Stop and update the counter
1307 			 */
1308 			riscv_pmu_stop(event, PERF_EF_UPDATE);
1309 			break;
1310 		case CPU_PM_EXIT:
1311 		case CPU_PM_ENTER_FAILED:
1312 			/*
1313 			 * Restore and enable the counter.
1314 			 */
1315 			riscv_pmu_start(event, PERF_EF_RELOAD);
1316 			break;
1317 		default:
1318 			break;
1319 		}
1320 	}
1321 
1322 	return NOTIFY_OK;
1323 }
1324 
1325 static int riscv_pm_pmu_register(struct riscv_pmu *pmu)
1326 {
1327 	pmu->riscv_pm_nb.notifier_call = riscv_pm_pmu_notify;
1328 	return cpu_pm_register_notifier(&pmu->riscv_pm_nb);
1329 }
1330 
1331 static void riscv_pm_pmu_unregister(struct riscv_pmu *pmu)
1332 {
1333 	cpu_pm_unregister_notifier(&pmu->riscv_pm_nb);
1334 }
1335 #else
1336 static inline int riscv_pm_pmu_register(struct riscv_pmu *pmu) { return 0; }
1337 static inline void riscv_pm_pmu_unregister(struct riscv_pmu *pmu) { }
1338 #endif
1339 
1340 static void riscv_pmu_destroy(struct riscv_pmu *pmu)
1341 {
1342 	if (sbi_v2_available) {
1343 		if (sbi_pmu_snapshot_available()) {
1344 			pmu_sbi_snapshot_disable();
1345 			pmu_sbi_snapshot_free(pmu);
1346 		}
1347 	}
1348 	riscv_pm_pmu_unregister(pmu);
1349 	if (!hlist_unhashed(&pmu->node))
1350 		cpuhp_state_remove_instance(CPUHP_AP_PERF_RISCV_STARTING, &pmu->node);
1351 }
1352 
1353 static void pmu_sbi_event_init(struct perf_event *event)
1354 {
1355 	/*
1356 	 * The permissions are set at event_init so that we do not depend
1357 	 * on the sysctl value that can change.
1358 	 */
1359 	if (sysctl_perf_user_access == SYSCTL_NO_USER_ACCESS)
1360 		event->hw.flags |= PERF_EVENT_FLAG_NO_USER_ACCESS;
1361 	else if (sysctl_perf_user_access == SYSCTL_USER_ACCESS)
1362 		event->hw.flags |= PERF_EVENT_FLAG_USER_ACCESS;
1363 	else
1364 		event->hw.flags |= PERF_EVENT_FLAG_LEGACY;
1365 }
1366 
1367 static void pmu_sbi_event_mapped(struct perf_event *event, struct mm_struct *mm)
1368 {
1369 	if (event->hw.flags & PERF_EVENT_FLAG_NO_USER_ACCESS)
1370 		return;
1371 
1372 	if (event->hw.flags & PERF_EVENT_FLAG_LEGACY) {
1373 		if (event->attr.config != PERF_COUNT_HW_CPU_CYCLES &&
1374 		    event->attr.config != PERF_COUNT_HW_INSTRUCTIONS) {
1375 			return;
1376 		}
1377 	}
1378 
1379 	/*
1380 	 * The user mmapped the event to directly access it: this is where
1381 	 * we determine based on sysctl_perf_user_access if we grant userspace
1382 	 * the direct access to this event. That means that within the same
1383 	 * task, some events may be directly accessible and some other may not,
1384 	 * if the user changes the value of sysctl_perf_user_accesss in the
1385 	 * meantime.
1386 	 */
1387 
1388 	event->hw.flags |= PERF_EVENT_FLAG_USER_READ_CNT;
1389 
1390 	/*
1391 	 * We must enable userspace access *before* advertising in the user page
1392 	 * that it is possible to do so to avoid any race.
1393 	 * And we must notify all cpus here because threads that currently run
1394 	 * on other cpus will try to directly access the counter too without
1395 	 * calling pmu_sbi_ctr_start.
1396 	 */
1397 	if (event->hw.flags & PERF_EVENT_FLAG_USER_ACCESS)
1398 		on_each_cpu_mask(mm_cpumask(mm),
1399 				 pmu_sbi_set_scounteren, (void *)event, 1);
1400 }
1401 
1402 static void pmu_sbi_event_unmapped(struct perf_event *event, struct mm_struct *mm)
1403 {
1404 	if (event->hw.flags & PERF_EVENT_FLAG_NO_USER_ACCESS)
1405 		return;
1406 
1407 	if (event->hw.flags & PERF_EVENT_FLAG_LEGACY) {
1408 		if (event->attr.config != PERF_COUNT_HW_CPU_CYCLES &&
1409 		    event->attr.config != PERF_COUNT_HW_INSTRUCTIONS) {
1410 			return;
1411 		}
1412 	}
1413 
1414 	/*
1415 	 * Here we can directly remove user access since the user does not have
1416 	 * access to the user page anymore so we avoid the racy window where the
1417 	 * user could have read cap_user_rdpmc to true right before we disable
1418 	 * it.
1419 	 */
1420 	event->hw.flags &= ~PERF_EVENT_FLAG_USER_READ_CNT;
1421 
1422 	if (event->hw.flags & PERF_EVENT_FLAG_USER_ACCESS)
1423 		on_each_cpu_mask(mm_cpumask(mm),
1424 				 pmu_sbi_reset_scounteren, (void *)event, 1);
1425 }
1426 
1427 static void riscv_pmu_update_counter_access(void *info)
1428 {
1429 	if (sysctl_perf_user_access == SYSCTL_LEGACY)
1430 		csr_write(CSR_SCOUNTEREN, 0x7);
1431 	else
1432 		csr_write(CSR_SCOUNTEREN, 0x2);
1433 }
1434 
1435 static int riscv_pmu_proc_user_access_handler(const struct ctl_table *table,
1436 					      int write, void *buffer,
1437 					      size_t *lenp, loff_t *ppos)
1438 {
1439 	int prev = sysctl_perf_user_access;
1440 	int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
1441 
1442 	/*
1443 	 * Test against the previous value since we clear SCOUNTEREN when
1444 	 * sysctl_perf_user_access is set to SYSCTL_USER_ACCESS, but we should
1445 	 * not do that if that was already the case.
1446 	 */
1447 	if (ret || !write || prev == sysctl_perf_user_access)
1448 		return ret;
1449 
1450 	on_each_cpu(riscv_pmu_update_counter_access, NULL, 1);
1451 
1452 	return 0;
1453 }
1454 
1455 static const struct ctl_table sbi_pmu_sysctl_table[] = {
1456 	{
1457 		.procname       = "perf_user_access",
1458 		.data		= &sysctl_perf_user_access,
1459 		.maxlen		= sizeof(unsigned int),
1460 		.mode           = 0644,
1461 		.proc_handler	= riscv_pmu_proc_user_access_handler,
1462 		.extra1		= SYSCTL_ZERO,
1463 		.extra2		= SYSCTL_TWO,
1464 	},
1465 };
1466 
1467 static int pmu_sbi_device_probe(struct platform_device *pdev)
1468 {
1469 	struct riscv_pmu *pmu = NULL;
1470 	int ret = -ENODEV;
1471 	int num_counters;
1472 	bool irq_requested = false;
1473 
1474 	pr_info("SBI PMU extension is available\n");
1475 	pmu = riscv_pmu_alloc();
1476 	if (!pmu)
1477 		return -ENOMEM;
1478 
1479 	num_counters = pmu_sbi_find_num_ctrs();
1480 	if (num_counters < 0) {
1481 		pr_err("SBI PMU extension doesn't provide any counters\n");
1482 		goto out_free;
1483 	}
1484 
1485 	/* It is possible to get from SBI more than max number of counters */
1486 	if (num_counters > RISCV_MAX_COUNTERS) {
1487 		num_counters = RISCV_MAX_COUNTERS;
1488 		pr_info("SBI returned more than maximum number of counters. Limiting the number of counters to %d\n", num_counters);
1489 	}
1490 
1491 	/* cache all the information about counters now */
1492 	if (pmu_sbi_get_ctrinfo(num_counters, cmask))
1493 		goto out_free;
1494 
1495 	ret = pmu_sbi_setup_irqs(pmu, pdev);
1496 	if (ret < 0) {
1497 		pr_info("Perf sampling/filtering is not supported as sscof extension is not available\n");
1498 		pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
1499 		pmu->pmu.capabilities |= PERF_PMU_CAP_NO_EXCLUDE;
1500 	}
1501 	irq_requested = (ret == 0);
1502 
1503 	pmu->pmu.attr_groups = riscv_pmu_attr_groups;
1504 	pmu->pmu.parent = &pdev->dev;
1505 	bitmap_copy(pmu->cmask, cmask, RISCV_MAX_COUNTERS);
1506 	pmu->ctr_start = pmu_sbi_ctr_start;
1507 	pmu->ctr_stop = pmu_sbi_ctr_stop;
1508 	pmu->event_map = pmu_sbi_event_map;
1509 	pmu->ctr_get_idx = pmu_sbi_ctr_get_idx;
1510 	pmu->ctr_get_width = pmu_sbi_ctr_get_width;
1511 	pmu->ctr_clear_idx = pmu_sbi_ctr_clear_idx;
1512 	pmu->ctr_read = pmu_sbi_ctr_read;
1513 	pmu->event_init = pmu_sbi_event_init;
1514 	pmu->event_mapped = pmu_sbi_event_mapped;
1515 	pmu->event_unmapped = pmu_sbi_event_unmapped;
1516 	pmu->csr_index = pmu_sbi_csr_index;
1517 
1518 	ret = riscv_pm_pmu_register(pmu);
1519 	if (ret)
1520 		goto out_destroy;
1521 
1522 	ret = perf_pmu_register(&pmu->pmu, "cpu", PERF_TYPE_RAW);
1523 	if (ret)
1524 		goto out_destroy;
1525 
1526 	/* SBI PMU Snapsphot is only available in SBI v2.0 */
1527 	if (sbi_v2_available) {
1528 		int cpu;
1529 
1530 		ret = pmu_sbi_snapshot_alloc(pmu);
1531 		if (ret)
1532 			goto out_unregister;
1533 
1534 		cpu = get_cpu();
1535 		ret = pmu_sbi_snapshot_setup(pmu, cpu);
1536 		put_cpu();
1537 
1538 		if (ret) {
1539 			/* Snapshot is an optional feature. Continue if not available */
1540 			pmu_sbi_snapshot_free(pmu);
1541 		} else {
1542 			pr_info("SBI PMU snapshot detected\n");
1543 			/*
1544 			 * We enable it once here for the boot cpu. If snapshot shmem setup
1545 			 * fails during cpu hotplug process, it will fail to start the cpu
1546 			 * as we can not handle hetergenous PMUs with different snapshot
1547 			 * capability.
1548 			 */
1549 			static_branch_enable(&sbi_pmu_snapshot_available);
1550 		}
1551 	}
1552 
1553 	register_sysctl("kernel", sbi_pmu_sysctl_table);
1554 
1555 	ret = cpuhp_state_add_instance(CPUHP_AP_PERF_RISCV_STARTING, &pmu->node);
1556 	if (ret)
1557 		goto out_unregister;
1558 
1559 	/* Asynchronously check which standard events are available */
1560 	schedule_work(&check_std_events_work);
1561 
1562 	return 0;
1563 
1564 out_unregister:
1565 	perf_pmu_unregister(&pmu->pmu);
1566 
1567 out_destroy:
1568 	riscv_pmu_destroy(pmu);
1569 	if (irq_requested) {
1570 		free_percpu_irq(riscv_pmu_irq, pmu->hw_events);
1571 		irq_dispose_mapping(riscv_pmu_irq);
1572 		riscv_pmu_irq = 0;
1573 	}
1574 
1575 out_free:
1576 	free_percpu(pmu->hw_events);
1577 	kfree(pmu_ctr_list);
1578 	pmu_ctr_list = NULL;
1579 	kfree(pmu);
1580 	return ret;
1581 }
1582 
1583 static struct platform_driver pmu_sbi_driver = {
1584 	.probe		= pmu_sbi_device_probe,
1585 	.driver		= {
1586 		.name	= RISCV_PMU_SBI_PDEV_NAME,
1587 	},
1588 };
1589 
1590 static int __init pmu_sbi_devinit(void)
1591 {
1592 	int ret;
1593 	struct platform_device *pdev;
1594 
1595 	if (sbi_spec_version < sbi_mk_version(0, 3) ||
1596 	    !sbi_probe_extension(SBI_EXT_PMU)) {
1597 		return 0;
1598 	}
1599 
1600 	if (sbi_spec_version >= sbi_mk_version(2, 0))
1601 		sbi_v2_available = true;
1602 
1603 	if (sbi_spec_version >= sbi_mk_version(3, 0))
1604 		sbi_v3_available = true;
1605 
1606 	ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_RISCV_STARTING,
1607 				      "perf/riscv/pmu:starting",
1608 				      pmu_sbi_starting_cpu, pmu_sbi_dying_cpu);
1609 	if (ret) {
1610 		pr_err("CPU hotplug notifier could not be registered: %d\n",
1611 		       ret);
1612 		return ret;
1613 	}
1614 
1615 	ret = platform_driver_register(&pmu_sbi_driver);
1616 	if (ret)
1617 		return ret;
1618 
1619 	pdev = platform_device_register_simple(RISCV_PMU_SBI_PDEV_NAME, -1, NULL, 0);
1620 	if (IS_ERR(pdev)) {
1621 		platform_driver_unregister(&pmu_sbi_driver);
1622 		return PTR_ERR(pdev);
1623 	}
1624 
1625 	/* Notify legacy implementation that SBI pmu is available*/
1626 	riscv_pmu_legacy_skip_init();
1627 
1628 	return ret;
1629 }
1630 device_initcall(pmu_sbi_devinit)
1631