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 #include <linux/soc/andes/irq.h>
23 #include <linux/workqueue.h>
24
25 #include <asm/errata_list.h>
26 #include <asm/sbi.h>
27 #include <asm/cpufeature.h>
28 #include <asm/vendor_extensions.h>
29 #include <asm/vendor_extensions/andes.h>
30
31 #define ALT_SBI_PMU_OVERFLOW(__ovl) \
32 asm volatile(ALTERNATIVE_2( \
33 "csrr %0, " __stringify(CSR_SCOUNTOVF), \
34 "csrr %0, " __stringify(THEAD_C9XX_CSR_SCOUNTEROF), \
35 THEAD_VENDOR_ID, ERRATA_THEAD_PMU, \
36 CONFIG_ERRATA_THEAD_PMU, \
37 "csrr %0, " __stringify(ANDES_CSR_SCOUNTEROF), \
38 ANDES_VENDOR_ID, \
39 RISCV_ISA_VENDOR_EXT_XANDESPMU + RISCV_VENDOR_EXT_ALTERNATIVES_BASE, \
40 CONFIG_ANDES_CUSTOM_PMU) \
41 : "=r" (__ovl) : \
42 : "memory")
43
44 #define ALT_SBI_PMU_OVF_CLEAR_PENDING(__irq_mask) \
45 asm volatile(ALTERNATIVE( \
46 "csrc " __stringify(CSR_IP) ", %0\n\t", \
47 "csrc " __stringify(ANDES_CSR_SLIP) ", %0\n\t", \
48 ANDES_VENDOR_ID, \
49 RISCV_ISA_VENDOR_EXT_XANDESPMU + RISCV_VENDOR_EXT_ALTERNATIVES_BASE, \
50 CONFIG_ANDES_CUSTOM_PMU) \
51 : : "r"(__irq_mask) \
52 : "memory")
53
54 #define SYSCTL_NO_USER_ACCESS 0
55 #define SYSCTL_USER_ACCESS 1
56 #define SYSCTL_LEGACY 2
57
58 #define PERF_EVENT_FLAG_NO_USER_ACCESS BIT(SYSCTL_NO_USER_ACCESS)
59 #define PERF_EVENT_FLAG_USER_ACCESS BIT(SYSCTL_USER_ACCESS)
60 #define PERF_EVENT_FLAG_LEGACY BIT(SYSCTL_LEGACY)
61
62 PMU_FORMAT_ATTR(event, "config:0-47");
63 PMU_FORMAT_ATTR(firmware, "config:62-63");
64
65 static bool sbi_v2_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 unsigned long cmask;
101
102 struct sbi_pmu_event_data {
103 union {
104 union {
105 struct hw_gen_event {
106 uint32_t event_code:16;
107 uint32_t event_type:4;
108 uint32_t reserved:12;
109 } hw_gen_event;
110 struct hw_cache_event {
111 uint32_t result_id:1;
112 uint32_t op_id:2;
113 uint32_t cache_id:13;
114 uint32_t event_type:4;
115 uint32_t reserved:12;
116 } hw_cache_event;
117 };
118 uint32_t event_idx;
119 };
120 };
121
122 static struct sbi_pmu_event_data pmu_hw_event_map[] = {
123 [PERF_COUNT_HW_CPU_CYCLES] = {.hw_gen_event = {
124 SBI_PMU_HW_CPU_CYCLES,
125 SBI_PMU_EVENT_TYPE_HW, 0}},
126 [PERF_COUNT_HW_INSTRUCTIONS] = {.hw_gen_event = {
127 SBI_PMU_HW_INSTRUCTIONS,
128 SBI_PMU_EVENT_TYPE_HW, 0}},
129 [PERF_COUNT_HW_CACHE_REFERENCES] = {.hw_gen_event = {
130 SBI_PMU_HW_CACHE_REFERENCES,
131 SBI_PMU_EVENT_TYPE_HW, 0}},
132 [PERF_COUNT_HW_CACHE_MISSES] = {.hw_gen_event = {
133 SBI_PMU_HW_CACHE_MISSES,
134 SBI_PMU_EVENT_TYPE_HW, 0}},
135 [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = {.hw_gen_event = {
136 SBI_PMU_HW_BRANCH_INSTRUCTIONS,
137 SBI_PMU_EVENT_TYPE_HW, 0}},
138 [PERF_COUNT_HW_BRANCH_MISSES] = {.hw_gen_event = {
139 SBI_PMU_HW_BRANCH_MISSES,
140 SBI_PMU_EVENT_TYPE_HW, 0}},
141 [PERF_COUNT_HW_BUS_CYCLES] = {.hw_gen_event = {
142 SBI_PMU_HW_BUS_CYCLES,
143 SBI_PMU_EVENT_TYPE_HW, 0}},
144 [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = {.hw_gen_event = {
145 SBI_PMU_HW_STALLED_CYCLES_FRONTEND,
146 SBI_PMU_EVENT_TYPE_HW, 0}},
147 [PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = {.hw_gen_event = {
148 SBI_PMU_HW_STALLED_CYCLES_BACKEND,
149 SBI_PMU_EVENT_TYPE_HW, 0}},
150 [PERF_COUNT_HW_REF_CPU_CYCLES] = {.hw_gen_event = {
151 SBI_PMU_HW_REF_CPU_CYCLES,
152 SBI_PMU_EVENT_TYPE_HW, 0}},
153 };
154
155 #define C(x) PERF_COUNT_HW_CACHE_##x
156 static struct sbi_pmu_event_data pmu_cache_event_map[PERF_COUNT_HW_CACHE_MAX]
157 [PERF_COUNT_HW_CACHE_OP_MAX]
158 [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
159 [C(L1D)] = {
160 [C(OP_READ)] = {
161 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
162 C(OP_READ), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
163 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
164 C(OP_READ), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
165 },
166 [C(OP_WRITE)] = {
167 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
168 C(OP_WRITE), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
169 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
170 C(OP_WRITE), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
171 },
172 [C(OP_PREFETCH)] = {
173 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
174 C(OP_PREFETCH), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
175 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
176 C(OP_PREFETCH), C(L1D), SBI_PMU_EVENT_TYPE_CACHE, 0}},
177 },
178 },
179 [C(L1I)] = {
180 [C(OP_READ)] = {
181 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
182 C(OP_READ), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
183 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS), C(OP_READ),
184 C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
185 },
186 [C(OP_WRITE)] = {
187 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
188 C(OP_WRITE), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
189 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
190 C(OP_WRITE), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
191 },
192 [C(OP_PREFETCH)] = {
193 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
194 C(OP_PREFETCH), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
195 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
196 C(OP_PREFETCH), C(L1I), SBI_PMU_EVENT_TYPE_CACHE, 0}},
197 },
198 },
199 [C(LL)] = {
200 [C(OP_READ)] = {
201 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
202 C(OP_READ), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
203 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
204 C(OP_READ), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
205 },
206 [C(OP_WRITE)] = {
207 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
208 C(OP_WRITE), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
209 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
210 C(OP_WRITE), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
211 },
212 [C(OP_PREFETCH)] = {
213 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
214 C(OP_PREFETCH), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
215 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
216 C(OP_PREFETCH), C(LL), SBI_PMU_EVENT_TYPE_CACHE, 0}},
217 },
218 },
219 [C(DTLB)] = {
220 [C(OP_READ)] = {
221 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
222 C(OP_READ), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
223 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
224 C(OP_READ), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
225 },
226 [C(OP_WRITE)] = {
227 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
228 C(OP_WRITE), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
229 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
230 C(OP_WRITE), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
231 },
232 [C(OP_PREFETCH)] = {
233 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
234 C(OP_PREFETCH), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
235 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
236 C(OP_PREFETCH), C(DTLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
237 },
238 },
239 [C(ITLB)] = {
240 [C(OP_READ)] = {
241 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
242 C(OP_READ), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
243 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
244 C(OP_READ), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
245 },
246 [C(OP_WRITE)] = {
247 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
248 C(OP_WRITE), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
249 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
250 C(OP_WRITE), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
251 },
252 [C(OP_PREFETCH)] = {
253 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
254 C(OP_PREFETCH), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
255 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
256 C(OP_PREFETCH), C(ITLB), SBI_PMU_EVENT_TYPE_CACHE, 0}},
257 },
258 },
259 [C(BPU)] = {
260 [C(OP_READ)] = {
261 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
262 C(OP_READ), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
263 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
264 C(OP_READ), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
265 },
266 [C(OP_WRITE)] = {
267 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
268 C(OP_WRITE), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
269 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
270 C(OP_WRITE), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
271 },
272 [C(OP_PREFETCH)] = {
273 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
274 C(OP_PREFETCH), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
275 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
276 C(OP_PREFETCH), C(BPU), SBI_PMU_EVENT_TYPE_CACHE, 0}},
277 },
278 },
279 [C(NODE)] = {
280 [C(OP_READ)] = {
281 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
282 C(OP_READ), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
283 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
284 C(OP_READ), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
285 },
286 [C(OP_WRITE)] = {
287 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
288 C(OP_WRITE), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
289 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
290 C(OP_WRITE), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
291 },
292 [C(OP_PREFETCH)] = {
293 [C(RESULT_ACCESS)] = {.hw_cache_event = {C(RESULT_ACCESS),
294 C(OP_PREFETCH), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
295 [C(RESULT_MISS)] = {.hw_cache_event = {C(RESULT_MISS),
296 C(OP_PREFETCH), C(NODE), SBI_PMU_EVENT_TYPE_CACHE, 0}},
297 },
298 },
299 };
300
pmu_sbi_check_event(struct sbi_pmu_event_data * edata)301 static void pmu_sbi_check_event(struct sbi_pmu_event_data *edata)
302 {
303 struct sbiret ret;
304
305 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH,
306 0, cmask, 0, edata->event_idx, 0, 0);
307 if (!ret.error) {
308 sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP,
309 ret.value, 0x1, SBI_PMU_STOP_FLAG_RESET, 0, 0, 0);
310 } else if (ret.error == SBI_ERR_NOT_SUPPORTED) {
311 /* This event cannot be monitored by any counter */
312 edata->event_idx = -ENOENT;
313 }
314 }
315
pmu_sbi_check_std_events(struct work_struct * work)316 static void pmu_sbi_check_std_events(struct work_struct *work)
317 {
318 for (int i = 0; i < ARRAY_SIZE(pmu_hw_event_map); i++)
319 pmu_sbi_check_event(&pmu_hw_event_map[i]);
320
321 for (int i = 0; i < ARRAY_SIZE(pmu_cache_event_map); i++)
322 for (int j = 0; j < ARRAY_SIZE(pmu_cache_event_map[i]); j++)
323 for (int k = 0; k < ARRAY_SIZE(pmu_cache_event_map[i][j]); k++)
324 pmu_sbi_check_event(&pmu_cache_event_map[i][j][k]);
325 }
326
327 static DECLARE_WORK(check_std_events_work, pmu_sbi_check_std_events);
328
pmu_sbi_ctr_get_width(int idx)329 static int pmu_sbi_ctr_get_width(int idx)
330 {
331 return pmu_ctr_list[idx].width;
332 }
333
pmu_sbi_ctr_is_fw(int cidx)334 static bool pmu_sbi_ctr_is_fw(int cidx)
335 {
336 union sbi_pmu_ctr_info *info;
337
338 info = &pmu_ctr_list[cidx];
339 if (!info)
340 return false;
341
342 return (info->type == SBI_PMU_CTR_TYPE_FW) ? true : false;
343 }
344
345 /*
346 * Returns the counter width of a programmable counter and number of hardware
347 * counters. As we don't support heterogeneous CPUs yet, it is okay to just
348 * return the counter width of the first programmable counter.
349 */
riscv_pmu_get_hpm_info(u32 * hw_ctr_width,u32 * num_hw_ctr)350 int riscv_pmu_get_hpm_info(u32 *hw_ctr_width, u32 *num_hw_ctr)
351 {
352 int i;
353 union sbi_pmu_ctr_info *info;
354 u32 hpm_width = 0, hpm_count = 0;
355
356 if (!cmask)
357 return -EINVAL;
358
359 for_each_set_bit(i, &cmask, RISCV_MAX_COUNTERS) {
360 info = &pmu_ctr_list[i];
361 if (!info)
362 continue;
363 if (!hpm_width && info->csr != CSR_CYCLE && info->csr != CSR_INSTRET)
364 hpm_width = info->width;
365 if (info->type == SBI_PMU_CTR_TYPE_HW)
366 hpm_count++;
367 }
368
369 *hw_ctr_width = hpm_width;
370 *num_hw_ctr = hpm_count;
371
372 return 0;
373 }
374 EXPORT_SYMBOL_GPL(riscv_pmu_get_hpm_info);
375
pmu_sbi_csr_index(struct perf_event * event)376 static uint8_t pmu_sbi_csr_index(struct perf_event *event)
377 {
378 return pmu_ctr_list[event->hw.idx].csr - CSR_CYCLE;
379 }
380
pmu_sbi_get_filter_flags(struct perf_event * event)381 static unsigned long pmu_sbi_get_filter_flags(struct perf_event *event)
382 {
383 unsigned long cflags = 0;
384 bool guest_events = false;
385
386 if (event->attr.config1 & RISCV_PMU_CONFIG1_GUEST_EVENTS)
387 guest_events = true;
388 if (event->attr.exclude_kernel)
389 cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VSINH : SBI_PMU_CFG_FLAG_SET_SINH;
390 if (event->attr.exclude_user)
391 cflags |= guest_events ? SBI_PMU_CFG_FLAG_SET_VUINH : SBI_PMU_CFG_FLAG_SET_UINH;
392 if (guest_events && event->attr.exclude_hv)
393 cflags |= SBI_PMU_CFG_FLAG_SET_SINH;
394 if (event->attr.exclude_host)
395 cflags |= SBI_PMU_CFG_FLAG_SET_UINH | SBI_PMU_CFG_FLAG_SET_SINH;
396 if (event->attr.exclude_guest)
397 cflags |= SBI_PMU_CFG_FLAG_SET_VSINH | SBI_PMU_CFG_FLAG_SET_VUINH;
398
399 return cflags;
400 }
401
pmu_sbi_ctr_get_idx(struct perf_event * event)402 static int pmu_sbi_ctr_get_idx(struct perf_event *event)
403 {
404 struct hw_perf_event *hwc = &event->hw;
405 struct riscv_pmu *rvpmu = to_riscv_pmu(event->pmu);
406 struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events);
407 struct sbiret ret;
408 int idx;
409 uint64_t cbase = 0, cmask = rvpmu->cmask;
410 unsigned long cflags = 0;
411
412 cflags = pmu_sbi_get_filter_flags(event);
413
414 /*
415 * In legacy mode, we have to force the fixed counters for those events
416 * but not in the user access mode as we want to use the other counters
417 * that support sampling/filtering.
418 */
419 if ((hwc->flags & PERF_EVENT_FLAG_LEGACY) && (event->attr.type == PERF_TYPE_HARDWARE)) {
420 if (event->attr.config == PERF_COUNT_HW_CPU_CYCLES) {
421 cflags |= SBI_PMU_CFG_FLAG_SKIP_MATCH;
422 cmask = 1;
423 } else if (event->attr.config == PERF_COUNT_HW_INSTRUCTIONS) {
424 cflags |= SBI_PMU_CFG_FLAG_SKIP_MATCH;
425 cmask = BIT(CSR_INSTRET - CSR_CYCLE);
426 }
427 }
428
429 /* retrieve the available counter index */
430 #if defined(CONFIG_32BIT)
431 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase,
432 cmask, cflags, hwc->event_base, hwc->config,
433 hwc->config >> 32);
434 #else
435 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase,
436 cmask, cflags, hwc->event_base, hwc->config, 0);
437 #endif
438 if (ret.error) {
439 pr_debug("Not able to find a counter for event %lx config %llx\n",
440 hwc->event_base, hwc->config);
441 return sbi_err_map_linux_errno(ret.error);
442 }
443
444 idx = ret.value;
445 if (!test_bit(idx, &rvpmu->cmask) || !pmu_ctr_list[idx].value)
446 return -ENOENT;
447
448 /* Additional sanity check for the counter id */
449 if (pmu_sbi_ctr_is_fw(idx)) {
450 if (!test_and_set_bit(idx, cpuc->used_fw_ctrs))
451 return idx;
452 } else {
453 if (!test_and_set_bit(idx, cpuc->used_hw_ctrs))
454 return idx;
455 }
456
457 return -ENOENT;
458 }
459
pmu_sbi_ctr_clear_idx(struct perf_event * event)460 static void pmu_sbi_ctr_clear_idx(struct perf_event *event)
461 {
462
463 struct hw_perf_event *hwc = &event->hw;
464 struct riscv_pmu *rvpmu = to_riscv_pmu(event->pmu);
465 struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events);
466 int idx = hwc->idx;
467
468 if (pmu_sbi_ctr_is_fw(idx))
469 clear_bit(idx, cpuc->used_fw_ctrs);
470 else
471 clear_bit(idx, cpuc->used_hw_ctrs);
472 }
473
pmu_event_find_cache(u64 config)474 static int pmu_event_find_cache(u64 config)
475 {
476 unsigned int cache_type, cache_op, cache_result, ret;
477
478 cache_type = (config >> 0) & 0xff;
479 if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
480 return -EINVAL;
481
482 cache_op = (config >> 8) & 0xff;
483 if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
484 return -EINVAL;
485
486 cache_result = (config >> 16) & 0xff;
487 if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
488 return -EINVAL;
489
490 ret = pmu_cache_event_map[cache_type][cache_op][cache_result].event_idx;
491
492 return ret;
493 }
494
pmu_sbi_is_fw_event(struct perf_event * event)495 static bool pmu_sbi_is_fw_event(struct perf_event *event)
496 {
497 u32 type = event->attr.type;
498 u64 config = event->attr.config;
499
500 if ((type == PERF_TYPE_RAW) && ((config >> 63) == 1))
501 return true;
502 else
503 return false;
504 }
505
pmu_sbi_event_map(struct perf_event * event,u64 * econfig)506 static int pmu_sbi_event_map(struct perf_event *event, u64 *econfig)
507 {
508 u32 type = event->attr.type;
509 u64 config = event->attr.config;
510 u64 raw_config_val;
511 int ret;
512
513 /*
514 * Ensure we are finished checking standard hardware events for
515 * validity before allowing userspace to configure any events.
516 */
517 flush_work(&check_std_events_work);
518
519 switch (type) {
520 case PERF_TYPE_HARDWARE:
521 if (config >= PERF_COUNT_HW_MAX)
522 return -EINVAL;
523 ret = pmu_hw_event_map[event->attr.config].event_idx;
524 break;
525 case PERF_TYPE_HW_CACHE:
526 ret = pmu_event_find_cache(config);
527 break;
528 case PERF_TYPE_RAW:
529 /*
530 * As per SBI specification, the upper 16 bits must be unused
531 * for a raw event.
532 * Bits 63:62 are used to distinguish between raw events
533 * 00 - Hardware raw event
534 * 10 - SBI firmware events
535 * 11 - Risc-V platform specific firmware event
536 */
537 raw_config_val = config & RISCV_PMU_RAW_EVENT_MASK;
538 switch (config >> 62) {
539 case 0:
540 ret = RISCV_PMU_RAW_EVENT_IDX;
541 *econfig = raw_config_val;
542 break;
543 case 2:
544 ret = (raw_config_val & 0xFFFF) |
545 (SBI_PMU_EVENT_TYPE_FW << 16);
546 break;
547 case 3:
548 /*
549 * For Risc-V platform specific firmware events
550 * Event code - 0xFFFF
551 * Event data - raw event encoding
552 */
553 ret = SBI_PMU_EVENT_TYPE_FW << 16 | RISCV_PLAT_FW_EVENT;
554 *econfig = raw_config_val;
555 break;
556 }
557 break;
558 default:
559 ret = -ENOENT;
560 break;
561 }
562
563 return ret;
564 }
565
pmu_sbi_snapshot_free(struct riscv_pmu * pmu)566 static void pmu_sbi_snapshot_free(struct riscv_pmu *pmu)
567 {
568 int cpu;
569
570 for_each_possible_cpu(cpu) {
571 struct cpu_hw_events *cpu_hw_evt = per_cpu_ptr(pmu->hw_events, cpu);
572
573 if (!cpu_hw_evt->snapshot_addr)
574 continue;
575
576 free_page((unsigned long)cpu_hw_evt->snapshot_addr);
577 cpu_hw_evt->snapshot_addr = NULL;
578 cpu_hw_evt->snapshot_addr_phys = 0;
579 }
580 }
581
pmu_sbi_snapshot_alloc(struct riscv_pmu * pmu)582 static int pmu_sbi_snapshot_alloc(struct riscv_pmu *pmu)
583 {
584 int cpu;
585 struct page *snapshot_page;
586
587 for_each_possible_cpu(cpu) {
588 struct cpu_hw_events *cpu_hw_evt = per_cpu_ptr(pmu->hw_events, cpu);
589
590 snapshot_page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
591 if (!snapshot_page) {
592 pmu_sbi_snapshot_free(pmu);
593 return -ENOMEM;
594 }
595 cpu_hw_evt->snapshot_addr = page_to_virt(snapshot_page);
596 cpu_hw_evt->snapshot_addr_phys = page_to_phys(snapshot_page);
597 }
598
599 return 0;
600 }
601
pmu_sbi_snapshot_disable(void)602 static int pmu_sbi_snapshot_disable(void)
603 {
604 struct sbiret ret;
605
606 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_SNAPSHOT_SET_SHMEM, SBI_SHMEM_DISABLE,
607 SBI_SHMEM_DISABLE, 0, 0, 0, 0);
608 if (ret.error) {
609 pr_warn("failed to disable snapshot shared memory\n");
610 return sbi_err_map_linux_errno(ret.error);
611 }
612
613 return 0;
614 }
615
pmu_sbi_snapshot_setup(struct riscv_pmu * pmu,int cpu)616 static int pmu_sbi_snapshot_setup(struct riscv_pmu *pmu, int cpu)
617 {
618 struct cpu_hw_events *cpu_hw_evt;
619 struct sbiret ret = {0};
620
621 cpu_hw_evt = per_cpu_ptr(pmu->hw_events, cpu);
622 if (!cpu_hw_evt->snapshot_addr_phys)
623 return -EINVAL;
624
625 if (cpu_hw_evt->snapshot_set_done)
626 return 0;
627
628 if (IS_ENABLED(CONFIG_32BIT))
629 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_SNAPSHOT_SET_SHMEM,
630 cpu_hw_evt->snapshot_addr_phys,
631 (u64)(cpu_hw_evt->snapshot_addr_phys) >> 32, 0, 0, 0, 0);
632 else
633 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_SNAPSHOT_SET_SHMEM,
634 cpu_hw_evt->snapshot_addr_phys, 0, 0, 0, 0, 0);
635
636 /* Free up the snapshot area memory and fall back to SBI PMU calls without snapshot */
637 if (ret.error) {
638 if (ret.error != SBI_ERR_NOT_SUPPORTED)
639 pr_warn("pmu snapshot setup failed with error %ld\n", ret.error);
640 return sbi_err_map_linux_errno(ret.error);
641 }
642
643 memset(cpu_hw_evt->snapshot_cval_shcopy, 0, sizeof(u64) * RISCV_MAX_COUNTERS);
644 cpu_hw_evt->snapshot_set_done = true;
645
646 return 0;
647 }
648
pmu_sbi_ctr_read(struct perf_event * event)649 static u64 pmu_sbi_ctr_read(struct perf_event *event)
650 {
651 struct hw_perf_event *hwc = &event->hw;
652 int idx = hwc->idx;
653 struct sbiret ret;
654 u64 val = 0;
655 struct riscv_pmu *pmu = to_riscv_pmu(event->pmu);
656 struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
657 struct riscv_pmu_snapshot_data *sdata = cpu_hw_evt->snapshot_addr;
658 union sbi_pmu_ctr_info info = pmu_ctr_list[idx];
659
660 /* Read the value from the shared memory directly only if counter is stopped */
661 if (sbi_pmu_snapshot_available() && (hwc->state & PERF_HES_STOPPED)) {
662 val = sdata->ctr_values[idx];
663 return val;
664 }
665
666 if (pmu_sbi_is_fw_event(event)) {
667 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_FW_READ,
668 hwc->idx, 0, 0, 0, 0, 0);
669 if (ret.error)
670 return 0;
671
672 val = ret.value;
673 if (IS_ENABLED(CONFIG_32BIT) && sbi_v2_available && info.width >= 32) {
674 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_FW_READ_HI,
675 hwc->idx, 0, 0, 0, 0, 0);
676 if (!ret.error)
677 val |= ((u64)ret.value << 32);
678 else
679 WARN_ONCE(1, "Unable to read upper 32 bits of firmware counter error: %ld\n",
680 ret.error);
681 }
682 } else {
683 val = riscv_pmu_ctr_read_csr(info.csr);
684 if (IS_ENABLED(CONFIG_32BIT))
685 val |= ((u64)riscv_pmu_ctr_read_csr(info.csr + 0x80)) << 32;
686 }
687
688 return val;
689 }
690
pmu_sbi_set_scounteren(void * arg)691 static void pmu_sbi_set_scounteren(void *arg)
692 {
693 struct perf_event *event = (struct perf_event *)arg;
694
695 if (event->hw.idx != -1)
696 csr_write(CSR_SCOUNTEREN,
697 csr_read(CSR_SCOUNTEREN) | BIT(pmu_sbi_csr_index(event)));
698 }
699
pmu_sbi_reset_scounteren(void * arg)700 static void pmu_sbi_reset_scounteren(void *arg)
701 {
702 struct perf_event *event = (struct perf_event *)arg;
703
704 if (event->hw.idx != -1)
705 csr_write(CSR_SCOUNTEREN,
706 csr_read(CSR_SCOUNTEREN) & ~BIT(pmu_sbi_csr_index(event)));
707 }
708
pmu_sbi_ctr_start(struct perf_event * event,u64 ival)709 static void pmu_sbi_ctr_start(struct perf_event *event, u64 ival)
710 {
711 struct sbiret ret;
712 struct hw_perf_event *hwc = &event->hw;
713 unsigned long flag = SBI_PMU_START_FLAG_SET_INIT_VALUE;
714
715 /* There is no benefit setting SNAPSHOT FLAG for a single counter */
716 #if defined(CONFIG_32BIT)
717 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, hwc->idx,
718 1, flag, ival, ival >> 32, 0);
719 #else
720 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, hwc->idx,
721 1, flag, ival, 0, 0);
722 #endif
723 if (ret.error && (ret.error != SBI_ERR_ALREADY_STARTED))
724 pr_err("Starting counter idx %d failed with error %d\n",
725 hwc->idx, sbi_err_map_linux_errno(ret.error));
726
727 if ((hwc->flags & PERF_EVENT_FLAG_USER_ACCESS) &&
728 (hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT))
729 pmu_sbi_set_scounteren((void *)event);
730 }
731
pmu_sbi_ctr_stop(struct perf_event * event,unsigned long flag)732 static void pmu_sbi_ctr_stop(struct perf_event *event, unsigned long flag)
733 {
734 struct sbiret ret;
735 struct hw_perf_event *hwc = &event->hw;
736 struct riscv_pmu *pmu = to_riscv_pmu(event->pmu);
737 struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
738 struct riscv_pmu_snapshot_data *sdata = cpu_hw_evt->snapshot_addr;
739
740 if ((hwc->flags & PERF_EVENT_FLAG_USER_ACCESS) &&
741 (hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT))
742 pmu_sbi_reset_scounteren((void *)event);
743
744 if (sbi_pmu_snapshot_available())
745 flag |= SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT;
746
747 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, hwc->idx, 1, flag, 0, 0, 0);
748 if (!ret.error && sbi_pmu_snapshot_available()) {
749 /*
750 * The counter snapshot is based on the index base specified by hwc->idx.
751 * The actual counter value is updated in shared memory at index 0 when counter
752 * mask is 0x01. To ensure accurate counter values, it's necessary to transfer
753 * the counter value to shared memory. However, if hwc->idx is zero, the counter
754 * value is already correctly updated in shared memory, requiring no further
755 * adjustment.
756 */
757 if (hwc->idx > 0) {
758 sdata->ctr_values[hwc->idx] = sdata->ctr_values[0];
759 sdata->ctr_values[0] = 0;
760 }
761 } else if (ret.error && (ret.error != SBI_ERR_ALREADY_STOPPED) &&
762 flag != SBI_PMU_STOP_FLAG_RESET) {
763 pr_err("Stopping counter idx %d failed with error %d\n",
764 hwc->idx, sbi_err_map_linux_errno(ret.error));
765 }
766 }
767
pmu_sbi_find_num_ctrs(void)768 static int pmu_sbi_find_num_ctrs(void)
769 {
770 struct sbiret ret;
771
772 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_NUM_COUNTERS, 0, 0, 0, 0, 0, 0);
773 if (!ret.error)
774 return ret.value;
775 else
776 return sbi_err_map_linux_errno(ret.error);
777 }
778
pmu_sbi_get_ctrinfo(int nctr,unsigned long * mask)779 static int pmu_sbi_get_ctrinfo(int nctr, unsigned long *mask)
780 {
781 struct sbiret ret;
782 int i, num_hw_ctr = 0, num_fw_ctr = 0;
783 union sbi_pmu_ctr_info cinfo;
784
785 pmu_ctr_list = kcalloc(nctr, sizeof(*pmu_ctr_list), GFP_KERNEL);
786 if (!pmu_ctr_list)
787 return -ENOMEM;
788
789 for (i = 0; i < nctr; i++) {
790 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_GET_INFO, i, 0, 0, 0, 0, 0);
791 if (ret.error)
792 /* The logical counter ids are not expected to be contiguous */
793 continue;
794
795 *mask |= BIT(i);
796
797 cinfo.value = ret.value;
798 if (cinfo.type == SBI_PMU_CTR_TYPE_FW)
799 num_fw_ctr++;
800 else
801 num_hw_ctr++;
802 pmu_ctr_list[i].value = cinfo.value;
803 }
804
805 pr_info("%d firmware and %d hardware counters\n", num_fw_ctr, num_hw_ctr);
806
807 return 0;
808 }
809
pmu_sbi_stop_all(struct riscv_pmu * pmu)810 static inline void pmu_sbi_stop_all(struct riscv_pmu *pmu)
811 {
812 /*
813 * No need to check the error because we are disabling all the counters
814 * which may include counters that are not enabled yet.
815 */
816 sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP,
817 0, pmu->cmask, SBI_PMU_STOP_FLAG_RESET, 0, 0, 0);
818 }
819
pmu_sbi_stop_hw_ctrs(struct riscv_pmu * pmu)820 static inline void pmu_sbi_stop_hw_ctrs(struct riscv_pmu *pmu)
821 {
822 struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
823 struct riscv_pmu_snapshot_data *sdata = cpu_hw_evt->snapshot_addr;
824 unsigned long flag = 0;
825 int i, idx;
826 struct sbiret ret;
827 u64 temp_ctr_overflow_mask = 0;
828
829 if (sbi_pmu_snapshot_available())
830 flag = SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT;
831
832 /* Reset the shadow copy to avoid save/restore any value from previous overflow */
833 memset(cpu_hw_evt->snapshot_cval_shcopy, 0, sizeof(u64) * RISCV_MAX_COUNTERS);
834
835 for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) {
836 /* No need to check the error here as we can't do anything about the error */
837 ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, i * BITS_PER_LONG,
838 cpu_hw_evt->used_hw_ctrs[i], flag, 0, 0, 0);
839 if (!ret.error && sbi_pmu_snapshot_available()) {
840 /* Save the counter values to avoid clobbering */
841 for_each_set_bit(idx, &cpu_hw_evt->used_hw_ctrs[i], BITS_PER_LONG)
842 cpu_hw_evt->snapshot_cval_shcopy[i * BITS_PER_LONG + idx] =
843 sdata->ctr_values[idx];
844 /* Save the overflow mask to avoid clobbering */
845 temp_ctr_overflow_mask |= sdata->ctr_overflow_mask << (i * BITS_PER_LONG);
846 }
847 }
848
849 /* Restore the counter values to the shared memory for used hw counters */
850 if (sbi_pmu_snapshot_available()) {
851 for_each_set_bit(idx, cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS)
852 sdata->ctr_values[idx] = cpu_hw_evt->snapshot_cval_shcopy[idx];
853 if (temp_ctr_overflow_mask)
854 sdata->ctr_overflow_mask = temp_ctr_overflow_mask;
855 }
856 }
857
858 /*
859 * This function starts all the used counters in two step approach.
860 * Any counter that did not overflow can be start in a single step
861 * while the overflowed counters need to be started with updated initialization
862 * value.
863 */
pmu_sbi_start_ovf_ctrs_sbi(struct cpu_hw_events * cpu_hw_evt,u64 ctr_ovf_mask)864 static inline void pmu_sbi_start_ovf_ctrs_sbi(struct cpu_hw_events *cpu_hw_evt,
865 u64 ctr_ovf_mask)
866 {
867 int idx = 0, i;
868 struct perf_event *event;
869 unsigned long flag = SBI_PMU_START_FLAG_SET_INIT_VALUE;
870 unsigned long ctr_start_mask = 0;
871 uint64_t max_period;
872 struct hw_perf_event *hwc;
873 u64 init_val = 0;
874
875 for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) {
876 ctr_start_mask = cpu_hw_evt->used_hw_ctrs[i] & ~ctr_ovf_mask;
877 /* Start all the counters that did not overflow in a single shot */
878 sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, i * BITS_PER_LONG, ctr_start_mask,
879 0, 0, 0, 0);
880 }
881
882 /* Reinitialize and start all the counter that overflowed */
883 while (ctr_ovf_mask) {
884 if (ctr_ovf_mask & 0x01) {
885 event = cpu_hw_evt->events[idx];
886 hwc = &event->hw;
887 max_period = riscv_pmu_ctr_get_width_mask(event);
888 init_val = local64_read(&hwc->prev_count) & max_period;
889 #if defined(CONFIG_32BIT)
890 sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx, 1,
891 flag, init_val, init_val >> 32, 0);
892 #else
893 sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx, 1,
894 flag, init_val, 0, 0);
895 #endif
896 perf_event_update_userpage(event);
897 }
898 ctr_ovf_mask = ctr_ovf_mask >> 1;
899 idx++;
900 }
901 }
902
pmu_sbi_start_ovf_ctrs_snapshot(struct cpu_hw_events * cpu_hw_evt,u64 ctr_ovf_mask)903 static inline void pmu_sbi_start_ovf_ctrs_snapshot(struct cpu_hw_events *cpu_hw_evt,
904 u64 ctr_ovf_mask)
905 {
906 int i, idx = 0;
907 struct perf_event *event;
908 unsigned long flag = SBI_PMU_START_FLAG_INIT_SNAPSHOT;
909 u64 max_period, init_val = 0;
910 struct hw_perf_event *hwc;
911 struct riscv_pmu_snapshot_data *sdata = cpu_hw_evt->snapshot_addr;
912
913 for_each_set_bit(idx, cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS) {
914 if (ctr_ovf_mask & BIT(idx)) {
915 event = cpu_hw_evt->events[idx];
916 hwc = &event->hw;
917 max_period = riscv_pmu_ctr_get_width_mask(event);
918 init_val = local64_read(&hwc->prev_count) & max_period;
919 cpu_hw_evt->snapshot_cval_shcopy[idx] = init_val;
920 }
921 /*
922 * We do not need to update the non-overflow counters the previous
923 * value should have been there already.
924 */
925 }
926
927 for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) {
928 /* Restore the counter values to relative indices for used hw counters */
929 for_each_set_bit(idx, &cpu_hw_evt->used_hw_ctrs[i], BITS_PER_LONG)
930 sdata->ctr_values[idx] =
931 cpu_hw_evt->snapshot_cval_shcopy[idx + i * BITS_PER_LONG];
932 /* Start all the counters in a single shot */
933 sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx * BITS_PER_LONG,
934 cpu_hw_evt->used_hw_ctrs[i], flag, 0, 0, 0);
935 }
936 }
937
pmu_sbi_start_overflow_mask(struct riscv_pmu * pmu,u64 ctr_ovf_mask)938 static void pmu_sbi_start_overflow_mask(struct riscv_pmu *pmu,
939 u64 ctr_ovf_mask)
940 {
941 struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
942
943 if (sbi_pmu_snapshot_available())
944 pmu_sbi_start_ovf_ctrs_snapshot(cpu_hw_evt, ctr_ovf_mask);
945 else
946 pmu_sbi_start_ovf_ctrs_sbi(cpu_hw_evt, ctr_ovf_mask);
947 }
948
pmu_sbi_ovf_handler(int irq,void * dev)949 static irqreturn_t pmu_sbi_ovf_handler(int irq, void *dev)
950 {
951 struct perf_sample_data data;
952 struct pt_regs *regs;
953 struct hw_perf_event *hw_evt;
954 union sbi_pmu_ctr_info *info;
955 int lidx, hidx, fidx;
956 struct riscv_pmu *pmu;
957 struct perf_event *event;
958 u64 overflow;
959 u64 overflowed_ctrs = 0;
960 struct cpu_hw_events *cpu_hw_evt = dev;
961 u64 start_clock = sched_clock();
962 struct riscv_pmu_snapshot_data *sdata = cpu_hw_evt->snapshot_addr;
963
964 if (WARN_ON_ONCE(!cpu_hw_evt))
965 return IRQ_NONE;
966
967 /* Firmware counter don't support overflow yet */
968 fidx = find_first_bit(cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS);
969 if (fidx == RISCV_MAX_COUNTERS) {
970 csr_clear(CSR_SIP, BIT(riscv_pmu_irq_num));
971 return IRQ_NONE;
972 }
973
974 event = cpu_hw_evt->events[fidx];
975 if (!event) {
976 ALT_SBI_PMU_OVF_CLEAR_PENDING(riscv_pmu_irq_mask);
977 return IRQ_NONE;
978 }
979
980 pmu = to_riscv_pmu(event->pmu);
981 pmu_sbi_stop_hw_ctrs(pmu);
982
983 /* Overflow status register should only be read after counter are stopped */
984 if (sbi_pmu_snapshot_available())
985 overflow = sdata->ctr_overflow_mask;
986 else
987 ALT_SBI_PMU_OVERFLOW(overflow);
988
989 /*
990 * Overflow interrupt pending bit should only be cleared after stopping
991 * all the counters to avoid any race condition.
992 */
993 ALT_SBI_PMU_OVF_CLEAR_PENDING(riscv_pmu_irq_mask);
994
995 /* No overflow bit is set */
996 if (!overflow)
997 return IRQ_NONE;
998
999 regs = get_irq_regs();
1000
1001 for_each_set_bit(lidx, cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS) {
1002 struct perf_event *event = cpu_hw_evt->events[lidx];
1003
1004 /* Skip if invalid event or user did not request a sampling */
1005 if (!event || !is_sampling_event(event))
1006 continue;
1007
1008 info = &pmu_ctr_list[lidx];
1009 /* Do a sanity check */
1010 if (!info || info->type != SBI_PMU_CTR_TYPE_HW)
1011 continue;
1012
1013 if (sbi_pmu_snapshot_available())
1014 /* SBI implementation already updated the logical indicies */
1015 hidx = lidx;
1016 else
1017 /* compute hardware counter index */
1018 hidx = info->csr - CSR_CYCLE;
1019
1020 /* check if the corresponding bit is set in sscountovf or overflow mask in shmem */
1021 if (!(overflow & BIT(hidx)))
1022 continue;
1023
1024 /*
1025 * Keep a track of overflowed counters so that they can be started
1026 * with updated initial value.
1027 */
1028 overflowed_ctrs |= BIT(lidx);
1029 hw_evt = &event->hw;
1030 /* Update the event states here so that we know the state while reading */
1031 hw_evt->state |= PERF_HES_STOPPED;
1032 riscv_pmu_event_update(event);
1033 hw_evt->state |= PERF_HES_UPTODATE;
1034 perf_sample_data_init(&data, 0, hw_evt->last_period);
1035 if (riscv_pmu_event_set_period(event)) {
1036 /*
1037 * Unlike other ISAs, RISC-V don't have to disable interrupts
1038 * to avoid throttling here. As per the specification, the
1039 * interrupt remains disabled until the OF bit is set.
1040 * Interrupts are enabled again only during the start.
1041 * TODO: We will need to stop the guest counters once
1042 * virtualization support is added.
1043 */
1044 perf_event_overflow(event, &data, regs);
1045 }
1046 /* Reset the state as we are going to start the counter after the loop */
1047 hw_evt->state = 0;
1048 }
1049
1050 pmu_sbi_start_overflow_mask(pmu, overflowed_ctrs);
1051 perf_sample_event_took(sched_clock() - start_clock);
1052
1053 return IRQ_HANDLED;
1054 }
1055
pmu_sbi_starting_cpu(unsigned int cpu,struct hlist_node * node)1056 static int pmu_sbi_starting_cpu(unsigned int cpu, struct hlist_node *node)
1057 {
1058 struct riscv_pmu *pmu = hlist_entry_safe(node, struct riscv_pmu, node);
1059 struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events);
1060
1061 /*
1062 * We keep enabling userspace access to CYCLE, TIME and INSTRET via the
1063 * legacy option but that will be removed in the future.
1064 */
1065 if (sysctl_perf_user_access == SYSCTL_LEGACY)
1066 csr_write(CSR_SCOUNTEREN, 0x7);
1067 else
1068 csr_write(CSR_SCOUNTEREN, 0x2);
1069
1070 /* Stop all the counters so that they can be enabled from perf */
1071 pmu_sbi_stop_all(pmu);
1072
1073 if (riscv_pmu_use_irq) {
1074 cpu_hw_evt->irq = riscv_pmu_irq;
1075 ALT_SBI_PMU_OVF_CLEAR_PENDING(riscv_pmu_irq_mask);
1076 enable_percpu_irq(riscv_pmu_irq, IRQ_TYPE_NONE);
1077 }
1078
1079 if (sbi_pmu_snapshot_available())
1080 return pmu_sbi_snapshot_setup(pmu, cpu);
1081
1082 return 0;
1083 }
1084
pmu_sbi_dying_cpu(unsigned int cpu,struct hlist_node * node)1085 static int pmu_sbi_dying_cpu(unsigned int cpu, struct hlist_node *node)
1086 {
1087 if (riscv_pmu_use_irq) {
1088 disable_percpu_irq(riscv_pmu_irq);
1089 }
1090
1091 /* Disable all counters access for user mode now */
1092 csr_write(CSR_SCOUNTEREN, 0x0);
1093
1094 if (sbi_pmu_snapshot_available())
1095 return pmu_sbi_snapshot_disable();
1096
1097 return 0;
1098 }
1099
pmu_sbi_setup_irqs(struct riscv_pmu * pmu,struct platform_device * pdev)1100 static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pdev)
1101 {
1102 int ret;
1103 struct cpu_hw_events __percpu *hw_events = pmu->hw_events;
1104 struct irq_domain *domain = NULL;
1105
1106 if (riscv_isa_extension_available(NULL, SSCOFPMF)) {
1107 riscv_pmu_irq_num = RV_IRQ_PMU;
1108 riscv_pmu_use_irq = true;
1109 } else if (IS_ENABLED(CONFIG_ERRATA_THEAD_PMU) &&
1110 riscv_cached_mvendorid(0) == THEAD_VENDOR_ID &&
1111 riscv_cached_marchid(0) == 0 &&
1112 riscv_cached_mimpid(0) == 0) {
1113 riscv_pmu_irq_num = THEAD_C9XX_RV_IRQ_PMU;
1114 riscv_pmu_use_irq = true;
1115 } else if (riscv_has_vendor_extension_unlikely(ANDES_VENDOR_ID,
1116 RISCV_ISA_VENDOR_EXT_XANDESPMU) &&
1117 IS_ENABLED(CONFIG_ANDES_CUSTOM_PMU)) {
1118 riscv_pmu_irq_num = ANDES_SLI_CAUSE_BASE + ANDES_RV_IRQ_PMOVI;
1119 riscv_pmu_use_irq = true;
1120 }
1121
1122 riscv_pmu_irq_mask = BIT(riscv_pmu_irq_num % BITS_PER_LONG);
1123
1124 if (!riscv_pmu_use_irq)
1125 return -EOPNOTSUPP;
1126
1127 domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
1128 DOMAIN_BUS_ANY);
1129 if (!domain) {
1130 pr_err("Failed to find INTC IRQ root domain\n");
1131 return -ENODEV;
1132 }
1133
1134 riscv_pmu_irq = irq_create_mapping(domain, riscv_pmu_irq_num);
1135 if (!riscv_pmu_irq) {
1136 pr_err("Failed to map PMU interrupt for node\n");
1137 return -ENODEV;
1138 }
1139
1140 ret = request_percpu_irq(riscv_pmu_irq, pmu_sbi_ovf_handler, "riscv-pmu", hw_events);
1141 if (ret) {
1142 pr_err("registering percpu irq failed [%d]\n", ret);
1143 return ret;
1144 }
1145
1146 return 0;
1147 }
1148
1149 #ifdef CONFIG_CPU_PM
riscv_pm_pmu_notify(struct notifier_block * b,unsigned long cmd,void * v)1150 static int riscv_pm_pmu_notify(struct notifier_block *b, unsigned long cmd,
1151 void *v)
1152 {
1153 struct riscv_pmu *rvpmu = container_of(b, struct riscv_pmu, riscv_pm_nb);
1154 struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events);
1155 int enabled = bitmap_weight(cpuc->used_hw_ctrs, RISCV_MAX_COUNTERS);
1156 struct perf_event *event;
1157 int idx;
1158
1159 if (!enabled)
1160 return NOTIFY_OK;
1161
1162 for (idx = 0; idx < RISCV_MAX_COUNTERS; idx++) {
1163 event = cpuc->events[idx];
1164 if (!event)
1165 continue;
1166
1167 switch (cmd) {
1168 case CPU_PM_ENTER:
1169 /*
1170 * Stop and update the counter
1171 */
1172 riscv_pmu_stop(event, PERF_EF_UPDATE);
1173 break;
1174 case CPU_PM_EXIT:
1175 case CPU_PM_ENTER_FAILED:
1176 /*
1177 * Restore and enable the counter.
1178 */
1179 riscv_pmu_start(event, PERF_EF_RELOAD);
1180 break;
1181 default:
1182 break;
1183 }
1184 }
1185
1186 return NOTIFY_OK;
1187 }
1188
riscv_pm_pmu_register(struct riscv_pmu * pmu)1189 static int riscv_pm_pmu_register(struct riscv_pmu *pmu)
1190 {
1191 pmu->riscv_pm_nb.notifier_call = riscv_pm_pmu_notify;
1192 return cpu_pm_register_notifier(&pmu->riscv_pm_nb);
1193 }
1194
riscv_pm_pmu_unregister(struct riscv_pmu * pmu)1195 static void riscv_pm_pmu_unregister(struct riscv_pmu *pmu)
1196 {
1197 cpu_pm_unregister_notifier(&pmu->riscv_pm_nb);
1198 }
1199 #else
riscv_pm_pmu_register(struct riscv_pmu * pmu)1200 static inline int riscv_pm_pmu_register(struct riscv_pmu *pmu) { return 0; }
riscv_pm_pmu_unregister(struct riscv_pmu * pmu)1201 static inline void riscv_pm_pmu_unregister(struct riscv_pmu *pmu) { }
1202 #endif
1203
riscv_pmu_destroy(struct riscv_pmu * pmu)1204 static void riscv_pmu_destroy(struct riscv_pmu *pmu)
1205 {
1206 if (sbi_v2_available) {
1207 if (sbi_pmu_snapshot_available()) {
1208 pmu_sbi_snapshot_disable();
1209 pmu_sbi_snapshot_free(pmu);
1210 }
1211 }
1212 riscv_pm_pmu_unregister(pmu);
1213 cpuhp_state_remove_instance(CPUHP_AP_PERF_RISCV_STARTING, &pmu->node);
1214 }
1215
pmu_sbi_event_init(struct perf_event * event)1216 static void pmu_sbi_event_init(struct perf_event *event)
1217 {
1218 /*
1219 * The permissions are set at event_init so that we do not depend
1220 * on the sysctl value that can change.
1221 */
1222 if (sysctl_perf_user_access == SYSCTL_NO_USER_ACCESS)
1223 event->hw.flags |= PERF_EVENT_FLAG_NO_USER_ACCESS;
1224 else if (sysctl_perf_user_access == SYSCTL_USER_ACCESS)
1225 event->hw.flags |= PERF_EVENT_FLAG_USER_ACCESS;
1226 else
1227 event->hw.flags |= PERF_EVENT_FLAG_LEGACY;
1228 }
1229
pmu_sbi_event_mapped(struct perf_event * event,struct mm_struct * mm)1230 static void pmu_sbi_event_mapped(struct perf_event *event, struct mm_struct *mm)
1231 {
1232 if (event->hw.flags & PERF_EVENT_FLAG_NO_USER_ACCESS)
1233 return;
1234
1235 if (event->hw.flags & PERF_EVENT_FLAG_LEGACY) {
1236 if (event->attr.config != PERF_COUNT_HW_CPU_CYCLES &&
1237 event->attr.config != PERF_COUNT_HW_INSTRUCTIONS) {
1238 return;
1239 }
1240 }
1241
1242 /*
1243 * The user mmapped the event to directly access it: this is where
1244 * we determine based on sysctl_perf_user_access if we grant userspace
1245 * the direct access to this event. That means that within the same
1246 * task, some events may be directly accessible and some other may not,
1247 * if the user changes the value of sysctl_perf_user_accesss in the
1248 * meantime.
1249 */
1250
1251 event->hw.flags |= PERF_EVENT_FLAG_USER_READ_CNT;
1252
1253 /*
1254 * We must enable userspace access *before* advertising in the user page
1255 * that it is possible to do so to avoid any race.
1256 * And we must notify all cpus here because threads that currently run
1257 * on other cpus will try to directly access the counter too without
1258 * calling pmu_sbi_ctr_start.
1259 */
1260 if (event->hw.flags & PERF_EVENT_FLAG_USER_ACCESS)
1261 on_each_cpu_mask(mm_cpumask(mm),
1262 pmu_sbi_set_scounteren, (void *)event, 1);
1263 }
1264
pmu_sbi_event_unmapped(struct perf_event * event,struct mm_struct * mm)1265 static void pmu_sbi_event_unmapped(struct perf_event *event, struct mm_struct *mm)
1266 {
1267 if (event->hw.flags & PERF_EVENT_FLAG_NO_USER_ACCESS)
1268 return;
1269
1270 if (event->hw.flags & PERF_EVENT_FLAG_LEGACY) {
1271 if (event->attr.config != PERF_COUNT_HW_CPU_CYCLES &&
1272 event->attr.config != PERF_COUNT_HW_INSTRUCTIONS) {
1273 return;
1274 }
1275 }
1276
1277 /*
1278 * Here we can directly remove user access since the user does not have
1279 * access to the user page anymore so we avoid the racy window where the
1280 * user could have read cap_user_rdpmc to true right before we disable
1281 * it.
1282 */
1283 event->hw.flags &= ~PERF_EVENT_FLAG_USER_READ_CNT;
1284
1285 if (event->hw.flags & PERF_EVENT_FLAG_USER_ACCESS)
1286 on_each_cpu_mask(mm_cpumask(mm),
1287 pmu_sbi_reset_scounteren, (void *)event, 1);
1288 }
1289
riscv_pmu_update_counter_access(void * info)1290 static void riscv_pmu_update_counter_access(void *info)
1291 {
1292 if (sysctl_perf_user_access == SYSCTL_LEGACY)
1293 csr_write(CSR_SCOUNTEREN, 0x7);
1294 else
1295 csr_write(CSR_SCOUNTEREN, 0x2);
1296 }
1297
riscv_pmu_proc_user_access_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1298 static int riscv_pmu_proc_user_access_handler(const struct ctl_table *table,
1299 int write, void *buffer,
1300 size_t *lenp, loff_t *ppos)
1301 {
1302 int prev = sysctl_perf_user_access;
1303 int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
1304
1305 /*
1306 * Test against the previous value since we clear SCOUNTEREN when
1307 * sysctl_perf_user_access is set to SYSCTL_USER_ACCESS, but we should
1308 * not do that if that was already the case.
1309 */
1310 if (ret || !write || prev == sysctl_perf_user_access)
1311 return ret;
1312
1313 on_each_cpu(riscv_pmu_update_counter_access, NULL, 1);
1314
1315 return 0;
1316 }
1317
1318 static struct ctl_table sbi_pmu_sysctl_table[] = {
1319 {
1320 .procname = "perf_user_access",
1321 .data = &sysctl_perf_user_access,
1322 .maxlen = sizeof(unsigned int),
1323 .mode = 0644,
1324 .proc_handler = riscv_pmu_proc_user_access_handler,
1325 .extra1 = SYSCTL_ZERO,
1326 .extra2 = SYSCTL_TWO,
1327 },
1328 };
1329
pmu_sbi_device_probe(struct platform_device * pdev)1330 static int pmu_sbi_device_probe(struct platform_device *pdev)
1331 {
1332 struct riscv_pmu *pmu = NULL;
1333 int ret = -ENODEV;
1334 int num_counters;
1335
1336 pr_info("SBI PMU extension is available\n");
1337 pmu = riscv_pmu_alloc();
1338 if (!pmu)
1339 return -ENOMEM;
1340
1341 num_counters = pmu_sbi_find_num_ctrs();
1342 if (num_counters < 0) {
1343 pr_err("SBI PMU extension doesn't provide any counters\n");
1344 goto out_free;
1345 }
1346
1347 /* It is possible to get from SBI more than max number of counters */
1348 if (num_counters > RISCV_MAX_COUNTERS) {
1349 num_counters = RISCV_MAX_COUNTERS;
1350 pr_info("SBI returned more than maximum number of counters. Limiting the number of counters to %d\n", num_counters);
1351 }
1352
1353 /* cache all the information about counters now */
1354 if (pmu_sbi_get_ctrinfo(num_counters, &cmask))
1355 goto out_free;
1356
1357 ret = pmu_sbi_setup_irqs(pmu, pdev);
1358 if (ret < 0) {
1359 pr_info("Perf sampling/filtering is not supported as sscof extension is not available\n");
1360 pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
1361 pmu->pmu.capabilities |= PERF_PMU_CAP_NO_EXCLUDE;
1362 }
1363
1364 pmu->pmu.attr_groups = riscv_pmu_attr_groups;
1365 pmu->pmu.parent = &pdev->dev;
1366 pmu->cmask = cmask;
1367 pmu->ctr_start = pmu_sbi_ctr_start;
1368 pmu->ctr_stop = pmu_sbi_ctr_stop;
1369 pmu->event_map = pmu_sbi_event_map;
1370 pmu->ctr_get_idx = pmu_sbi_ctr_get_idx;
1371 pmu->ctr_get_width = pmu_sbi_ctr_get_width;
1372 pmu->ctr_clear_idx = pmu_sbi_ctr_clear_idx;
1373 pmu->ctr_read = pmu_sbi_ctr_read;
1374 pmu->event_init = pmu_sbi_event_init;
1375 pmu->event_mapped = pmu_sbi_event_mapped;
1376 pmu->event_unmapped = pmu_sbi_event_unmapped;
1377 pmu->csr_index = pmu_sbi_csr_index;
1378
1379 ret = riscv_pm_pmu_register(pmu);
1380 if (ret)
1381 goto out_unregister;
1382
1383 ret = perf_pmu_register(&pmu->pmu, "cpu", PERF_TYPE_RAW);
1384 if (ret)
1385 goto out_unregister;
1386
1387 /* SBI PMU Snapsphot is only available in SBI v2.0 */
1388 if (sbi_v2_available) {
1389 int cpu;
1390
1391 ret = pmu_sbi_snapshot_alloc(pmu);
1392 if (ret)
1393 goto out_unregister;
1394
1395 cpu = get_cpu();
1396 ret = pmu_sbi_snapshot_setup(pmu, cpu);
1397 put_cpu();
1398
1399 if (ret) {
1400 /* Snapshot is an optional feature. Continue if not available */
1401 pmu_sbi_snapshot_free(pmu);
1402 } else {
1403 pr_info("SBI PMU snapshot detected\n");
1404 /*
1405 * We enable it once here for the boot cpu. If snapshot shmem setup
1406 * fails during cpu hotplug process, it will fail to start the cpu
1407 * as we can not handle hetergenous PMUs with different snapshot
1408 * capability.
1409 */
1410 static_branch_enable(&sbi_pmu_snapshot_available);
1411 }
1412 }
1413
1414 register_sysctl("kernel", sbi_pmu_sysctl_table);
1415
1416 ret = cpuhp_state_add_instance(CPUHP_AP_PERF_RISCV_STARTING, &pmu->node);
1417 if (ret)
1418 goto out_unregister;
1419
1420 /* Asynchronously check which standard events are available */
1421 schedule_work(&check_std_events_work);
1422
1423 return 0;
1424
1425 out_unregister:
1426 riscv_pmu_destroy(pmu);
1427
1428 out_free:
1429 kfree(pmu);
1430 return ret;
1431 }
1432
1433 static struct platform_driver pmu_sbi_driver = {
1434 .probe = pmu_sbi_device_probe,
1435 .driver = {
1436 .name = RISCV_PMU_SBI_PDEV_NAME,
1437 },
1438 };
1439
pmu_sbi_devinit(void)1440 static int __init pmu_sbi_devinit(void)
1441 {
1442 int ret;
1443 struct platform_device *pdev;
1444
1445 if (sbi_spec_version < sbi_mk_version(0, 3) ||
1446 !sbi_probe_extension(SBI_EXT_PMU)) {
1447 return 0;
1448 }
1449
1450 if (sbi_spec_version >= sbi_mk_version(2, 0))
1451 sbi_v2_available = true;
1452
1453 ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_RISCV_STARTING,
1454 "perf/riscv/pmu:starting",
1455 pmu_sbi_starting_cpu, pmu_sbi_dying_cpu);
1456 if (ret) {
1457 pr_err("CPU hotplug notifier could not be registered: %d\n",
1458 ret);
1459 return ret;
1460 }
1461
1462 ret = platform_driver_register(&pmu_sbi_driver);
1463 if (ret)
1464 return ret;
1465
1466 pdev = platform_device_register_simple(RISCV_PMU_SBI_PDEV_NAME, -1, NULL, 0);
1467 if (IS_ERR(pdev)) {
1468 platform_driver_unregister(&pmu_sbi_driver);
1469 return PTR_ERR(pdev);
1470 }
1471
1472 /* Notify legacy implementation that SBI pmu is available*/
1473 riscv_pmu_legacy_skip_init();
1474
1475 return ret;
1476 }
1477 device_initcall(pmu_sbi_devinit)
1478