1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Perf support for the Statistical Profiling Extension, introduced as
4 * part of ARMv8.2.
5 *
6 * Copyright (C) 2016 ARM Limited
7 *
8 * Author: Will Deacon <will.deacon@arm.com>
9 */
10
11 #define PMUNAME "arm_spe"
12 #define DRVNAME PMUNAME "_pmu"
13 #define pr_fmt(fmt) DRVNAME ": " fmt
14
15 #include <linux/bitfield.h>
16 #include <linux/bitops.h>
17 #include <linux/bug.h>
18 #include <linux/capability.h>
19 #include <linux/cpuhotplug.h>
20 #include <linux/cpumask.h>
21 #include <linux/device.h>
22 #include <linux/errno.h>
23 #include <linux/interrupt.h>
24 #include <linux/irq.h>
25 #include <linux/kernel.h>
26 #include <linux/list.h>
27 #include <linux/module.h>
28 #include <linux/of.h>
29 #include <linux/perf_event.h>
30 #include <linux/perf/arm_pmu.h>
31 #include <linux/platform_device.h>
32 #include <linux/printk.h>
33 #include <linux/slab.h>
34 #include <linux/smp.h>
35 #include <linux/vmalloc.h>
36
37 #include <asm/barrier.h>
38 #include <asm/cpufeature.h>
39 #include <asm/mmu.h>
40 #include <asm/sysreg.h>
41
42 /*
43 * Cache if the event is allowed to trace Context information.
44 * This allows us to perform the check, i.e, perf_allow_kernel(),
45 * in the context of the event owner, once, during the event_init().
46 */
47 #define SPE_PMU_HW_FLAGS_CX 0x00001
48
49 static_assert((PERF_EVENT_FLAG_ARCH & SPE_PMU_HW_FLAGS_CX) == SPE_PMU_HW_FLAGS_CX);
50
set_spe_event_has_cx(struct perf_event * event)51 static void set_spe_event_has_cx(struct perf_event *event)
52 {
53 if (IS_ENABLED(CONFIG_PID_IN_CONTEXTIDR) && !perf_allow_kernel())
54 event->hw.flags |= SPE_PMU_HW_FLAGS_CX;
55 }
56
get_spe_event_has_cx(struct perf_event * event)57 static bool get_spe_event_has_cx(struct perf_event *event)
58 {
59 return !!(event->hw.flags & SPE_PMU_HW_FLAGS_CX);
60 }
61
62 #define ARM_SPE_BUF_PAD_BYTE 0
63
64 struct arm_spe_pmu_buf {
65 int nr_pages;
66 bool snapshot;
67 void *base;
68 };
69
70 struct arm_spe_pmu {
71 struct pmu pmu;
72 struct platform_device *pdev;
73 cpumask_t supported_cpus;
74 struct hlist_node hotplug_node;
75
76 int irq; /* PPI */
77 u16 pmsver;
78 u16 min_period;
79 u16 counter_sz;
80
81 #define SPE_PMU_FEAT_FILT_EVT (1UL << 0)
82 #define SPE_PMU_FEAT_FILT_TYP (1UL << 1)
83 #define SPE_PMU_FEAT_FILT_LAT (1UL << 2)
84 #define SPE_PMU_FEAT_ARCH_INST (1UL << 3)
85 #define SPE_PMU_FEAT_LDS (1UL << 4)
86 #define SPE_PMU_FEAT_ERND (1UL << 5)
87 #define SPE_PMU_FEAT_INV_FILT_EVT (1UL << 6)
88 #define SPE_PMU_FEAT_DISCARD (1UL << 7)
89 #define SPE_PMU_FEAT_EFT (1UL << 8)
90 #define SPE_PMU_FEAT_FDS (1UL << 9)
91 #define SPE_PMU_FEAT_DEV_PROBED (1UL << 63)
92 u64 features;
93
94 u64 pmsevfr_res0;
95 u16 max_record_sz;
96 u16 align;
97 struct perf_output_handle __percpu *handle;
98 };
99
100 #define to_spe_pmu(p) (container_of(p, struct arm_spe_pmu, pmu))
101
102 /* Convert a free-running index from perf into an SPE buffer offset */
103 #define PERF_IDX2OFF(idx, buf) \
104 ((idx) % ((unsigned long)(buf)->nr_pages << PAGE_SHIFT))
105
106 /* Keep track of our dynamic hotplug state */
107 static enum cpuhp_state arm_spe_pmu_online;
108
109 static void arm_spe_pmu_stop(struct perf_event *event, int flags);
110
111 enum arm_spe_pmu_buf_fault_action {
112 SPE_PMU_BUF_FAULT_ACT_SPURIOUS,
113 SPE_PMU_BUF_FAULT_ACT_FATAL,
114 SPE_PMU_BUF_FAULT_ACT_OK,
115 };
116
117 /* This sysfs gunk was really good fun to write. */
118 enum arm_spe_pmu_capabilities {
119 SPE_PMU_CAP_ARCH_INST = 0,
120 SPE_PMU_CAP_ERND,
121 SPE_PMU_CAP_FEAT_MAX,
122 SPE_PMU_CAP_CNT_SZ = SPE_PMU_CAP_FEAT_MAX,
123 SPE_PMU_CAP_MIN_IVAL,
124 SPE_PMU_CAP_EVENT_FILTER,
125 };
126
127 static int arm_spe_pmu_feat_caps[SPE_PMU_CAP_FEAT_MAX] = {
128 [SPE_PMU_CAP_ARCH_INST] = SPE_PMU_FEAT_ARCH_INST,
129 [SPE_PMU_CAP_ERND] = SPE_PMU_FEAT_ERND,
130 };
131
arm_spe_pmu_cap_get(struct arm_spe_pmu * spe_pmu,int cap)132 static u64 arm_spe_pmu_cap_get(struct arm_spe_pmu *spe_pmu, int cap)
133 {
134 if (cap < SPE_PMU_CAP_FEAT_MAX)
135 return !!(spe_pmu->features & arm_spe_pmu_feat_caps[cap]);
136
137 switch (cap) {
138 case SPE_PMU_CAP_CNT_SZ:
139 return spe_pmu->counter_sz;
140 case SPE_PMU_CAP_MIN_IVAL:
141 return spe_pmu->min_period;
142 case SPE_PMU_CAP_EVENT_FILTER:
143 return ~spe_pmu->pmsevfr_res0;
144 default:
145 WARN(1, "unknown cap %d\n", cap);
146 }
147
148 return 0;
149 }
150
arm_spe_pmu_cap_show(struct device * dev,struct device_attribute * attr,char * buf)151 static ssize_t arm_spe_pmu_cap_show(struct device *dev,
152 struct device_attribute *attr,
153 char *buf)
154 {
155 struct arm_spe_pmu *spe_pmu = dev_get_drvdata(dev);
156 struct dev_ext_attribute *ea =
157 container_of(attr, struct dev_ext_attribute, attr);
158 int cap = (long)ea->var;
159
160 return sysfs_emit(buf, "%llu\n", arm_spe_pmu_cap_get(spe_pmu, cap));
161 }
162
arm_spe_pmu_cap_show_hex(struct device * dev,struct device_attribute * attr,char * buf)163 static ssize_t arm_spe_pmu_cap_show_hex(struct device *dev,
164 struct device_attribute *attr,
165 char *buf)
166 {
167 struct arm_spe_pmu *spe_pmu = dev_get_drvdata(dev);
168 struct dev_ext_attribute *ea =
169 container_of(attr, struct dev_ext_attribute, attr);
170 int cap = (long)ea->var;
171
172 return sysfs_emit(buf, "0x%llx\n", arm_spe_pmu_cap_get(spe_pmu, cap));
173 }
174
175 #define SPE_EXT_ATTR_ENTRY(_name, _func, _var) \
176 &((struct dev_ext_attribute[]) { \
177 { __ATTR(_name, S_IRUGO, _func, NULL), (void *)_var } \
178 })[0].attr.attr
179
180 #define SPE_CAP_EXT_ATTR_ENTRY(_name, _var) \
181 SPE_EXT_ATTR_ENTRY(_name, arm_spe_pmu_cap_show, _var)
182 #define SPE_CAP_EXT_ATTR_ENTRY_HEX(_name, _var) \
183 SPE_EXT_ATTR_ENTRY(_name, arm_spe_pmu_cap_show_hex, _var)
184
185 static struct attribute *arm_spe_pmu_cap_attr[] = {
186 SPE_CAP_EXT_ATTR_ENTRY(arch_inst, SPE_PMU_CAP_ARCH_INST),
187 SPE_CAP_EXT_ATTR_ENTRY(ernd, SPE_PMU_CAP_ERND),
188 SPE_CAP_EXT_ATTR_ENTRY(count_size, SPE_PMU_CAP_CNT_SZ),
189 SPE_CAP_EXT_ATTR_ENTRY(min_interval, SPE_PMU_CAP_MIN_IVAL),
190 SPE_CAP_EXT_ATTR_ENTRY_HEX(event_filter, SPE_PMU_CAP_EVENT_FILTER),
191 NULL,
192 };
193
194 static const struct attribute_group arm_spe_pmu_cap_group = {
195 .name = "caps",
196 .attrs = arm_spe_pmu_cap_attr,
197 };
198
199 /* User ABI */
200 #define ATTR_CFG_FLD_ts_enable_CFG config /* PMSCR_EL1.TS */
201 #define ATTR_CFG_FLD_ts_enable_LO 0
202 #define ATTR_CFG_FLD_ts_enable_HI 0
203 #define ATTR_CFG_FLD_pa_enable_CFG config /* PMSCR_EL1.PA */
204 #define ATTR_CFG_FLD_pa_enable_LO 1
205 #define ATTR_CFG_FLD_pa_enable_HI 1
206 #define ATTR_CFG_FLD_pct_enable_CFG config /* PMSCR_EL1.PCT */
207 #define ATTR_CFG_FLD_pct_enable_LO 2
208 #define ATTR_CFG_FLD_pct_enable_HI 2
209 #define ATTR_CFG_FLD_jitter_CFG config /* PMSIRR_EL1.RND */
210 #define ATTR_CFG_FLD_jitter_LO 16
211 #define ATTR_CFG_FLD_jitter_HI 16
212 #define ATTR_CFG_FLD_branch_filter_CFG config /* PMSFCR_EL1.B */
213 #define ATTR_CFG_FLD_branch_filter_LO 32
214 #define ATTR_CFG_FLD_branch_filter_HI 32
215 #define ATTR_CFG_FLD_load_filter_CFG config /* PMSFCR_EL1.LD */
216 #define ATTR_CFG_FLD_load_filter_LO 33
217 #define ATTR_CFG_FLD_load_filter_HI 33
218 #define ATTR_CFG_FLD_store_filter_CFG config /* PMSFCR_EL1.ST */
219 #define ATTR_CFG_FLD_store_filter_LO 34
220 #define ATTR_CFG_FLD_store_filter_HI 34
221 #define ATTR_CFG_FLD_discard_CFG config /* PMBLIMITR_EL1.FM = DISCARD */
222 #define ATTR_CFG_FLD_discard_LO 35
223 #define ATTR_CFG_FLD_discard_HI 35
224 #define ATTR_CFG_FLD_branch_filter_mask_CFG config /* PMSFCR_EL1.Bm */
225 #define ATTR_CFG_FLD_branch_filter_mask_LO 36
226 #define ATTR_CFG_FLD_branch_filter_mask_HI 36
227 #define ATTR_CFG_FLD_load_filter_mask_CFG config /* PMSFCR_EL1.LDm */
228 #define ATTR_CFG_FLD_load_filter_mask_LO 37
229 #define ATTR_CFG_FLD_load_filter_mask_HI 37
230 #define ATTR_CFG_FLD_store_filter_mask_CFG config /* PMSFCR_EL1.STm */
231 #define ATTR_CFG_FLD_store_filter_mask_LO 38
232 #define ATTR_CFG_FLD_store_filter_mask_HI 38
233 #define ATTR_CFG_FLD_simd_filter_CFG config /* PMSFCR_EL1.SIMD */
234 #define ATTR_CFG_FLD_simd_filter_LO 39
235 #define ATTR_CFG_FLD_simd_filter_HI 39
236 #define ATTR_CFG_FLD_simd_filter_mask_CFG config /* PMSFCR_EL1.SIMDm */
237 #define ATTR_CFG_FLD_simd_filter_mask_LO 40
238 #define ATTR_CFG_FLD_simd_filter_mask_HI 40
239 #define ATTR_CFG_FLD_float_filter_CFG config /* PMSFCR_EL1.FP */
240 #define ATTR_CFG_FLD_float_filter_LO 41
241 #define ATTR_CFG_FLD_float_filter_HI 41
242 #define ATTR_CFG_FLD_float_filter_mask_CFG config /* PMSFCR_EL1.FPm */
243 #define ATTR_CFG_FLD_float_filter_mask_LO 42
244 #define ATTR_CFG_FLD_float_filter_mask_HI 42
245
246 #define ATTR_CFG_FLD_event_filter_CFG config1 /* PMSEVFR_EL1 */
247 #define ATTR_CFG_FLD_event_filter_LO 0
248 #define ATTR_CFG_FLD_event_filter_HI 63
249
250 #define ATTR_CFG_FLD_min_latency_CFG config2 /* PMSLATFR_EL1.MINLAT */
251 #define ATTR_CFG_FLD_min_latency_LO 0
252 #define ATTR_CFG_FLD_min_latency_HI 11
253
254 #define ATTR_CFG_FLD_inv_event_filter_CFG config3 /* PMSNEVFR_EL1 */
255 #define ATTR_CFG_FLD_inv_event_filter_LO 0
256 #define ATTR_CFG_FLD_inv_event_filter_HI 63
257
258 #define ATTR_CFG_FLD_inv_data_src_filter_CFG config4 /* inverse of PMSDSFR_EL1 */
259 #define ATTR_CFG_FLD_inv_data_src_filter_LO 0
260 #define ATTR_CFG_FLD_inv_data_src_filter_HI 63
261
262 GEN_PMU_FORMAT_ATTR(ts_enable);
263 GEN_PMU_FORMAT_ATTR(pa_enable);
264 GEN_PMU_FORMAT_ATTR(pct_enable);
265 GEN_PMU_FORMAT_ATTR(jitter);
266 GEN_PMU_FORMAT_ATTR(branch_filter);
267 GEN_PMU_FORMAT_ATTR(branch_filter_mask);
268 GEN_PMU_FORMAT_ATTR(load_filter);
269 GEN_PMU_FORMAT_ATTR(load_filter_mask);
270 GEN_PMU_FORMAT_ATTR(store_filter);
271 GEN_PMU_FORMAT_ATTR(store_filter_mask);
272 GEN_PMU_FORMAT_ATTR(simd_filter);
273 GEN_PMU_FORMAT_ATTR(simd_filter_mask);
274 GEN_PMU_FORMAT_ATTR(float_filter);
275 GEN_PMU_FORMAT_ATTR(float_filter_mask);
276 GEN_PMU_FORMAT_ATTR(event_filter);
277 GEN_PMU_FORMAT_ATTR(inv_event_filter);
278 GEN_PMU_FORMAT_ATTR(inv_data_src_filter);
279 GEN_PMU_FORMAT_ATTR(min_latency);
280 GEN_PMU_FORMAT_ATTR(discard);
281
282 static struct attribute *arm_spe_pmu_formats_attr[] = {
283 &format_attr_ts_enable.attr,
284 &format_attr_pa_enable.attr,
285 &format_attr_pct_enable.attr,
286 &format_attr_jitter.attr,
287 &format_attr_branch_filter.attr,
288 &format_attr_branch_filter_mask.attr,
289 &format_attr_load_filter.attr,
290 &format_attr_load_filter_mask.attr,
291 &format_attr_store_filter.attr,
292 &format_attr_store_filter_mask.attr,
293 &format_attr_simd_filter.attr,
294 &format_attr_simd_filter_mask.attr,
295 &format_attr_float_filter.attr,
296 &format_attr_float_filter_mask.attr,
297 &format_attr_event_filter.attr,
298 &format_attr_inv_event_filter.attr,
299 &format_attr_inv_data_src_filter.attr,
300 &format_attr_min_latency.attr,
301 &format_attr_discard.attr,
302 NULL,
303 };
304
arm_spe_pmu_format_attr_is_visible(struct kobject * kobj,struct attribute * attr,int unused)305 static umode_t arm_spe_pmu_format_attr_is_visible(struct kobject *kobj,
306 struct attribute *attr,
307 int unused)
308 {
309 struct device *dev = kobj_to_dev(kobj);
310 struct arm_spe_pmu *spe_pmu = dev_get_drvdata(dev);
311
312 if (attr == &format_attr_discard.attr && !(spe_pmu->features & SPE_PMU_FEAT_DISCARD))
313 return 0;
314
315 if (attr == &format_attr_inv_event_filter.attr && !(spe_pmu->features & SPE_PMU_FEAT_INV_FILT_EVT))
316 return 0;
317
318 if (attr == &format_attr_inv_data_src_filter.attr &&
319 !(spe_pmu->features & SPE_PMU_FEAT_FDS))
320 return 0;
321
322 if ((attr == &format_attr_branch_filter_mask.attr ||
323 attr == &format_attr_load_filter_mask.attr ||
324 attr == &format_attr_store_filter_mask.attr ||
325 attr == &format_attr_simd_filter.attr ||
326 attr == &format_attr_simd_filter_mask.attr ||
327 attr == &format_attr_float_filter.attr ||
328 attr == &format_attr_float_filter_mask.attr) &&
329 !(spe_pmu->features & SPE_PMU_FEAT_EFT))
330 return 0;
331
332 return attr->mode;
333 }
334
335 static const struct attribute_group arm_spe_pmu_format_group = {
336 .name = "format",
337 .is_visible = arm_spe_pmu_format_attr_is_visible,
338 .attrs = arm_spe_pmu_formats_attr,
339 };
340
cpumask_show(struct device * dev,struct device_attribute * attr,char * buf)341 static ssize_t cpumask_show(struct device *dev,
342 struct device_attribute *attr, char *buf)
343 {
344 struct arm_spe_pmu *spe_pmu = dev_get_drvdata(dev);
345
346 return cpumap_print_to_pagebuf(true, buf, &spe_pmu->supported_cpus);
347 }
348 static DEVICE_ATTR_RO(cpumask);
349
350 static struct attribute *arm_spe_pmu_attrs[] = {
351 &dev_attr_cpumask.attr,
352 NULL,
353 };
354
355 static const struct attribute_group arm_spe_pmu_group = {
356 .attrs = arm_spe_pmu_attrs,
357 };
358
359 static const struct attribute_group *arm_spe_pmu_attr_groups[] = {
360 &arm_spe_pmu_group,
361 &arm_spe_pmu_cap_group,
362 &arm_spe_pmu_format_group,
363 NULL,
364 };
365
366 /* Convert between user ABI and register values */
arm_spe_event_to_pmscr(struct perf_event * event)367 static u64 arm_spe_event_to_pmscr(struct perf_event *event)
368 {
369 struct perf_event_attr *attr = &event->attr;
370 u64 reg = 0;
371
372 reg |= FIELD_PREP(PMSCR_EL1_TS, ATTR_CFG_GET_FLD(attr, ts_enable));
373 reg |= FIELD_PREP(PMSCR_EL1_PA, ATTR_CFG_GET_FLD(attr, pa_enable));
374 reg |= FIELD_PREP(PMSCR_EL1_PCT, ATTR_CFG_GET_FLD(attr, pct_enable));
375
376 if (!attr->exclude_user)
377 reg |= PMSCR_EL1_E0SPE;
378
379 if (!attr->exclude_kernel)
380 reg |= PMSCR_EL1_E1SPE;
381
382 if (get_spe_event_has_cx(event))
383 reg |= PMSCR_EL1_CX;
384
385 return reg;
386 }
387
arm_spe_event_sanitise_period(struct perf_event * event)388 static void arm_spe_event_sanitise_period(struct perf_event *event)
389 {
390 u64 period = event->hw.sample_period;
391 u64 max_period = PMSIRR_EL1_INTERVAL_MASK;
392
393 /*
394 * The PMSIDR_EL1.Interval field (stored in spe_pmu->min_period) is a
395 * recommendation for the minimum interval, not a hardware limitation.
396 *
397 * According to the Arm ARM (DDI 0487 L.a), section D24.7.12 PMSIRR_EL1,
398 * Sampling Interval Reload Register, the INTERVAL field (bits [31:8])
399 * states: "Software must set this to a nonzero value". Use 1 as the
400 * minimum value.
401 */
402 u64 min_period = FIELD_PREP(PMSIRR_EL1_INTERVAL_MASK, 1);
403
404 period = clamp_t(u64, period, min_period, max_period) & max_period;
405 event->hw.sample_period = period;
406 }
407
arm_spe_event_to_pmsirr(struct perf_event * event)408 static u64 arm_spe_event_to_pmsirr(struct perf_event *event)
409 {
410 struct perf_event_attr *attr = &event->attr;
411 u64 reg = 0;
412
413 arm_spe_event_sanitise_period(event);
414
415 reg |= FIELD_PREP(PMSIRR_EL1_RND, ATTR_CFG_GET_FLD(attr, jitter));
416 reg |= event->hw.sample_period;
417
418 return reg;
419 }
420
arm_spe_event_to_pmsfcr(struct perf_event * event)421 static u64 arm_spe_event_to_pmsfcr(struct perf_event *event)
422 {
423 struct perf_event_attr *attr = &event->attr;
424 u64 reg = 0;
425
426 reg |= FIELD_PREP(PMSFCR_EL1_LD, ATTR_CFG_GET_FLD(attr, load_filter));
427 reg |= FIELD_PREP(PMSFCR_EL1_LDm, ATTR_CFG_GET_FLD(attr, load_filter_mask));
428 reg |= FIELD_PREP(PMSFCR_EL1_ST, ATTR_CFG_GET_FLD(attr, store_filter));
429 reg |= FIELD_PREP(PMSFCR_EL1_STm, ATTR_CFG_GET_FLD(attr, store_filter_mask));
430 reg |= FIELD_PREP(PMSFCR_EL1_B, ATTR_CFG_GET_FLD(attr, branch_filter));
431 reg |= FIELD_PREP(PMSFCR_EL1_Bm, ATTR_CFG_GET_FLD(attr, branch_filter_mask));
432 reg |= FIELD_PREP(PMSFCR_EL1_SIMD, ATTR_CFG_GET_FLD(attr, simd_filter));
433 reg |= FIELD_PREP(PMSFCR_EL1_SIMDm, ATTR_CFG_GET_FLD(attr, simd_filter_mask));
434 reg |= FIELD_PREP(PMSFCR_EL1_FP, ATTR_CFG_GET_FLD(attr, float_filter));
435 reg |= FIELD_PREP(PMSFCR_EL1_FPm, ATTR_CFG_GET_FLD(attr, float_filter_mask));
436
437 if (reg)
438 reg |= PMSFCR_EL1_FT;
439
440 if (ATTR_CFG_GET_FLD(attr, event_filter))
441 reg |= PMSFCR_EL1_FE;
442
443 if (ATTR_CFG_GET_FLD(attr, inv_event_filter))
444 reg |= PMSFCR_EL1_FnE;
445
446 if (ATTR_CFG_GET_FLD(attr, inv_data_src_filter))
447 reg |= PMSFCR_EL1_FDS;
448
449 if (ATTR_CFG_GET_FLD(attr, min_latency))
450 reg |= PMSFCR_EL1_FL;
451
452 return reg;
453 }
454
arm_spe_event_to_pmsevfr(struct perf_event * event)455 static u64 arm_spe_event_to_pmsevfr(struct perf_event *event)
456 {
457 struct perf_event_attr *attr = &event->attr;
458 return ATTR_CFG_GET_FLD(attr, event_filter);
459 }
460
arm_spe_event_to_pmsnevfr(struct perf_event * event)461 static u64 arm_spe_event_to_pmsnevfr(struct perf_event *event)
462 {
463 struct perf_event_attr *attr = &event->attr;
464 return ATTR_CFG_GET_FLD(attr, inv_event_filter);
465 }
466
arm_spe_event_to_pmslatfr(struct perf_event * event)467 static u64 arm_spe_event_to_pmslatfr(struct perf_event *event)
468 {
469 struct perf_event_attr *attr = &event->attr;
470 return FIELD_PREP(PMSLATFR_EL1_MINLAT, ATTR_CFG_GET_FLD(attr, min_latency));
471 }
472
arm_spe_event_to_pmsdsfr(struct perf_event * event)473 static u64 arm_spe_event_to_pmsdsfr(struct perf_event *event)
474 {
475 struct perf_event_attr *attr = &event->attr;
476
477 /*
478 * Data src filter is inverted so that the default value of 0 is
479 * equivalent to no filtering.
480 */
481 return ~ATTR_CFG_GET_FLD(attr, inv_data_src_filter);
482 }
483
arm_spe_pmu_pad_buf(struct perf_output_handle * handle,int len)484 static void arm_spe_pmu_pad_buf(struct perf_output_handle *handle, int len)
485 {
486 struct arm_spe_pmu_buf *buf = perf_get_aux(handle);
487 u64 head = PERF_IDX2OFF(handle->head, buf);
488
489 memset(buf->base + head, ARM_SPE_BUF_PAD_BYTE, len);
490 if (!buf->snapshot)
491 perf_aux_output_skip(handle, len);
492 }
493
arm_spe_pmu_next_snapshot_off(struct perf_output_handle * handle)494 static u64 arm_spe_pmu_next_snapshot_off(struct perf_output_handle *handle)
495 {
496 struct arm_spe_pmu_buf *buf = perf_get_aux(handle);
497 struct arm_spe_pmu *spe_pmu = to_spe_pmu(handle->event->pmu);
498 u64 head = PERF_IDX2OFF(handle->head, buf);
499 u64 limit = buf->nr_pages * PAGE_SIZE;
500
501 /*
502 * The trace format isn't parseable in reverse, so clamp
503 * the limit to half of the buffer size in snapshot mode
504 * so that the worst case is half a buffer of records, as
505 * opposed to a single record.
506 */
507 if (head < limit >> 1)
508 limit >>= 1;
509
510 /*
511 * If we're within max_record_sz of the limit, we must
512 * pad, move the head index and recompute the limit.
513 */
514 if (limit - head < spe_pmu->max_record_sz) {
515 arm_spe_pmu_pad_buf(handle, limit - head);
516 handle->head = PERF_IDX2OFF(limit, buf);
517 limit = ((buf->nr_pages * PAGE_SIZE) >> 1) + handle->head;
518 }
519
520 return limit;
521 }
522
__arm_spe_pmu_next_off(struct perf_output_handle * handle)523 static u64 __arm_spe_pmu_next_off(struct perf_output_handle *handle)
524 {
525 struct arm_spe_pmu *spe_pmu = to_spe_pmu(handle->event->pmu);
526 struct arm_spe_pmu_buf *buf = perf_get_aux(handle);
527 const u64 bufsize = buf->nr_pages * PAGE_SIZE;
528 u64 limit = bufsize;
529 u64 head, tail, wakeup;
530
531 /*
532 * The head can be misaligned for two reasons:
533 *
534 * 1. The hardware left PMBPTR pointing to the first byte after
535 * a record when generating a buffer management event.
536 *
537 * 2. We used perf_aux_output_skip to consume handle->size bytes
538 * and CIRC_SPACE was used to compute the size, which always
539 * leaves one entry free.
540 *
541 * Deal with this by padding to the next alignment boundary and
542 * moving the head index. If we run out of buffer space, we'll
543 * reduce handle->size to zero and end up reporting truncation.
544 */
545 head = PERF_IDX2OFF(handle->head, buf);
546 if (!IS_ALIGNED(head, spe_pmu->align)) {
547 unsigned long delta = roundup(head, spe_pmu->align) - head;
548
549 delta = min(delta, handle->size);
550 arm_spe_pmu_pad_buf(handle, delta);
551 head = PERF_IDX2OFF(handle->head, buf);
552 }
553
554 /* If we've run out of free space, then nothing more to do */
555 if (!handle->size)
556 goto no_space;
557
558 /* Compute the tail and wakeup indices now that we've aligned head */
559 tail = PERF_IDX2OFF(handle->head + handle->size, buf);
560 wakeup = PERF_IDX2OFF(handle->wakeup, buf);
561
562 /*
563 * Avoid clobbering unconsumed data. We know we have space, so
564 * if we see head == tail we know that the buffer is empty. If
565 * head > tail, then there's nothing to clobber prior to
566 * wrapping.
567 */
568 if (head < tail)
569 limit = round_down(tail, PAGE_SIZE);
570
571 /*
572 * Wakeup may be arbitrarily far into the future. If it's not in
573 * the current generation, either we'll wrap before hitting it,
574 * or it's in the past and has been handled already.
575 *
576 * If there's a wakeup before we wrap, arrange to be woken up by
577 * the page boundary following it. Keep the tail boundary if
578 * that's lower.
579 */
580 if (handle->wakeup < (handle->head + handle->size) && head <= wakeup)
581 limit = min(limit, round_up(wakeup, PAGE_SIZE));
582
583 if (limit > head)
584 return limit;
585
586 arm_spe_pmu_pad_buf(handle, handle->size);
587 no_space:
588 perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
589 perf_aux_output_end(handle, 0);
590 return 0;
591 }
592
arm_spe_pmu_next_off(struct perf_output_handle * handle)593 static u64 arm_spe_pmu_next_off(struct perf_output_handle *handle)
594 {
595 struct arm_spe_pmu_buf *buf = perf_get_aux(handle);
596 struct arm_spe_pmu *spe_pmu = to_spe_pmu(handle->event->pmu);
597 u64 limit = __arm_spe_pmu_next_off(handle);
598 u64 head = PERF_IDX2OFF(handle->head, buf);
599
600 /*
601 * If the head has come too close to the end of the buffer,
602 * then pad to the end and recompute the limit.
603 */
604 if (limit && (limit - head < spe_pmu->max_record_sz)) {
605 arm_spe_pmu_pad_buf(handle, limit - head);
606 limit = __arm_spe_pmu_next_off(handle);
607 }
608
609 return limit;
610 }
611
arm_spe_perf_aux_output_begin(struct perf_output_handle * handle,struct perf_event * event)612 static int arm_spe_perf_aux_output_begin(struct perf_output_handle *handle,
613 struct perf_event *event)
614 {
615 u64 base, limit;
616 struct arm_spe_pmu_buf *buf;
617
618 if (ATTR_CFG_GET_FLD(&event->attr, discard)) {
619 limit = FIELD_PREP(PMBLIMITR_EL1_FM, PMBLIMITR_EL1_FM_DISCARD);
620 limit |= PMBLIMITR_EL1_E;
621 goto out_write_limit;
622 }
623
624 /* Start a new aux session */
625 buf = perf_aux_output_begin(handle, event);
626 if (!buf) {
627 /*
628 * We still need to clear the limit pointer, since the
629 * profiler might only be disabled by virtue of a fault.
630 */
631 limit = 0;
632 goto out_write_limit;
633 }
634
635 limit = buf->snapshot ? arm_spe_pmu_next_snapshot_off(handle)
636 : arm_spe_pmu_next_off(handle);
637 if (limit)
638 limit |= PMBLIMITR_EL1_E;
639
640 limit += (u64)buf->base;
641 base = (u64)buf->base + PERF_IDX2OFF(handle->head, buf);
642 write_sysreg_s(base, SYS_PMBPTR_EL1);
643
644 out_write_limit:
645 write_sysreg_s(limit, SYS_PMBLIMITR_EL1);
646 return (limit & PMBLIMITR_EL1_E) ? 0 : -EIO;
647 }
648
arm_spe_perf_aux_output_end(struct perf_output_handle * handle)649 static void arm_spe_perf_aux_output_end(struct perf_output_handle *handle)
650 {
651 struct arm_spe_pmu_buf *buf = perf_get_aux(handle);
652 u64 offset, size;
653
654 offset = read_sysreg_s(SYS_PMBPTR_EL1) - (u64)buf->base;
655 size = offset - PERF_IDX2OFF(handle->head, buf);
656
657 if (buf->snapshot)
658 handle->head = offset;
659
660 perf_aux_output_end(handle, size);
661 }
662
arm_spe_pmu_disable_and_drain_local(void)663 static void arm_spe_pmu_disable_and_drain_local(void)
664 {
665 /* Disable profiling at EL0 and EL1 */
666 write_sysreg_s(0, SYS_PMSCR_EL1);
667 isb();
668
669 /* Drain any buffered data */
670 psb_csync();
671 dsb(nsh);
672
673 /* Disable the profiling buffer */
674 write_sysreg_s(0, SYS_PMBLIMITR_EL1);
675 isb();
676 }
677
678 /* IRQ handling */
679 static enum arm_spe_pmu_buf_fault_action
arm_spe_pmu_buf_get_fault_act(struct perf_output_handle * handle)680 arm_spe_pmu_buf_get_fault_act(struct perf_output_handle *handle)
681 {
682 const char *err_str;
683 u64 pmbsr;
684 enum arm_spe_pmu_buf_fault_action ret;
685
686 /*
687 * Ensure new profiling data is visible to the CPU and any external
688 * aborts have been resolved.
689 */
690 psb_csync();
691 dsb(nsh);
692
693 /* Ensure hardware updates to PMBPTR_EL1 are visible */
694 isb();
695
696 /* Service required? */
697 pmbsr = read_sysreg_s(SYS_PMBSR_EL1);
698 if (!FIELD_GET(PMBSR_EL1_S, pmbsr))
699 return SPE_PMU_BUF_FAULT_ACT_SPURIOUS;
700
701 /*
702 * If we've lost data, disable profiling and also set the PARTIAL
703 * flag to indicate that the last record is corrupted.
704 */
705 if (FIELD_GET(PMBSR_EL1_DL, pmbsr))
706 perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED |
707 PERF_AUX_FLAG_PARTIAL);
708
709 /* Report collisions to userspace so that it can up the period */
710 if (FIELD_GET(PMBSR_EL1_COLL, pmbsr))
711 perf_aux_output_flag(handle, PERF_AUX_FLAG_COLLISION);
712
713 /* We only expect buffer management events */
714 switch (FIELD_GET(PMBSR_EL1_EC, pmbsr)) {
715 case PMBSR_EL1_EC_BUF:
716 /* Handled below */
717 break;
718 case PMBSR_EL1_EC_FAULT_S1:
719 case PMBSR_EL1_EC_FAULT_S2:
720 err_str = "Unexpected buffer fault";
721 goto out_err;
722 default:
723 err_str = "Unknown error code";
724 goto out_err;
725 }
726
727 /* Buffer management event */
728 switch (FIELD_GET(PMBSR_EL1_BUF_BSC_MASK, pmbsr)) {
729 case PMBSR_EL1_BUF_BSC_FULL:
730 ret = SPE_PMU_BUF_FAULT_ACT_OK;
731 goto out_stop;
732 default:
733 err_str = "Unknown buffer status code";
734 }
735
736 out_err:
737 pr_err_ratelimited("%s on CPU %d [PMBSR=0x%016llx, PMBPTR=0x%016llx, PMBLIMITR=0x%016llx]\n",
738 err_str, smp_processor_id(), pmbsr,
739 read_sysreg_s(SYS_PMBPTR_EL1),
740 read_sysreg_s(SYS_PMBLIMITR_EL1));
741 ret = SPE_PMU_BUF_FAULT_ACT_FATAL;
742
743 out_stop:
744 arm_spe_perf_aux_output_end(handle);
745 return ret;
746 }
747
arm_spe_pmu_irq_handler(int irq,void * dev)748 static irqreturn_t arm_spe_pmu_irq_handler(int irq, void *dev)
749 {
750 struct perf_output_handle *handle = dev;
751 struct perf_event *event = handle->event;
752 enum arm_spe_pmu_buf_fault_action act;
753
754 if (!perf_get_aux(handle))
755 return IRQ_NONE;
756
757 act = arm_spe_pmu_buf_get_fault_act(handle);
758 if (act == SPE_PMU_BUF_FAULT_ACT_SPURIOUS)
759 return IRQ_NONE;
760
761 /*
762 * Ensure perf callbacks have completed, which may disable the
763 * profiling buffer in response to a TRUNCATION flag.
764 */
765 irq_work_run();
766
767 switch (act) {
768 case SPE_PMU_BUF_FAULT_ACT_FATAL:
769 /*
770 * If a fatal exception occurred then leaving the profiling
771 * buffer enabled is a recipe waiting to happen. Since
772 * fatal faults don't always imply truncation, make sure
773 * that the profiling buffer is disabled explicitly before
774 * clearing the syndrome register.
775 */
776 arm_spe_pmu_disable_and_drain_local();
777 break;
778 case SPE_PMU_BUF_FAULT_ACT_OK:
779 /*
780 * We handled the fault (the buffer was full), so resume
781 * profiling as long as we didn't detect truncation.
782 * PMBPTR might be misaligned, but we'll burn that bridge
783 * when we get to it.
784 */
785 if (!(handle->aux_flags & PERF_AUX_FLAG_TRUNCATED)) {
786 if (arm_spe_perf_aux_output_begin(handle, event)) {
787 arm_spe_pmu_stop(event, PERF_EF_UPDATE);
788 break;
789 }
790 isb();
791 }
792 break;
793 case SPE_PMU_BUF_FAULT_ACT_SPURIOUS:
794 /* We've seen you before, but GCC has the memory of a sieve. */
795 break;
796 }
797
798 /* The buffer pointers are now sane, so resume profiling. */
799 write_sysreg_s(0, SYS_PMBSR_EL1);
800 return IRQ_HANDLED;
801 }
802
803 /* Perf callbacks */
arm_spe_pmu_event_init(struct perf_event * event)804 static int arm_spe_pmu_event_init(struct perf_event *event)
805 {
806 u64 reg;
807 struct perf_event_attr *attr = &event->attr;
808 struct arm_spe_pmu *spe_pmu = to_spe_pmu(event->pmu);
809
810 /* This is, of course, deeply driver-specific */
811 if (attr->type != event->pmu->type)
812 return -ENOENT;
813
814 if (event->cpu >= 0 &&
815 !cpumask_test_cpu(event->cpu, &spe_pmu->supported_cpus))
816 return -ENOENT;
817
818 if (arm_spe_event_to_pmsevfr(event) & spe_pmu->pmsevfr_res0)
819 return -EOPNOTSUPP;
820
821 if (arm_spe_event_to_pmsnevfr(event) & spe_pmu->pmsevfr_res0)
822 return -EOPNOTSUPP;
823
824 if (arm_spe_event_to_pmsdsfr(event) != U64_MAX &&
825 !(spe_pmu->features & SPE_PMU_FEAT_FDS))
826 return -EOPNOTSUPP;
827
828 if (attr->exclude_idle)
829 return -EOPNOTSUPP;
830
831 /*
832 * Feedback-directed frequency throttling doesn't work when we
833 * have a buffer of samples. We'd need to manually count the
834 * samples in the buffer when it fills up and adjust the event
835 * count to reflect that. Instead, just force the user to specify
836 * a sample period.
837 */
838 if (attr->freq)
839 return -EINVAL;
840
841 reg = arm_spe_event_to_pmsfcr(event);
842 if ((FIELD_GET(PMSFCR_EL1_FE, reg)) &&
843 !(spe_pmu->features & SPE_PMU_FEAT_FILT_EVT))
844 return -EOPNOTSUPP;
845
846 if ((FIELD_GET(PMSFCR_EL1_FnE, reg)) &&
847 !(spe_pmu->features & SPE_PMU_FEAT_INV_FILT_EVT))
848 return -EOPNOTSUPP;
849
850 if ((FIELD_GET(PMSFCR_EL1_FT, reg)) &&
851 !(spe_pmu->features & SPE_PMU_FEAT_FILT_TYP))
852 return -EOPNOTSUPP;
853
854 if ((FIELD_GET(PMSFCR_EL1_FL, reg)) &&
855 !(spe_pmu->features & SPE_PMU_FEAT_FILT_LAT))
856 return -EOPNOTSUPP;
857
858 if ((FIELD_GET(PMSFCR_EL1_LDm, reg) ||
859 FIELD_GET(PMSFCR_EL1_STm, reg) ||
860 FIELD_GET(PMSFCR_EL1_Bm, reg) ||
861 FIELD_GET(PMSFCR_EL1_SIMD, reg) ||
862 FIELD_GET(PMSFCR_EL1_SIMDm, reg) ||
863 FIELD_GET(PMSFCR_EL1_FP, reg) ||
864 FIELD_GET(PMSFCR_EL1_FPm, reg)) &&
865 !(spe_pmu->features & SPE_PMU_FEAT_EFT))
866 return -EOPNOTSUPP;
867
868 if (ATTR_CFG_GET_FLD(&event->attr, discard) &&
869 !(spe_pmu->features & SPE_PMU_FEAT_DISCARD))
870 return -EOPNOTSUPP;
871
872 set_spe_event_has_cx(event);
873 reg = arm_spe_event_to_pmscr(event);
874 if (reg & (PMSCR_EL1_PA | PMSCR_EL1_PCT))
875 return perf_allow_kernel();
876
877 return 0;
878 }
879
arm_spe_pmu_start(struct perf_event * event,int flags)880 static void arm_spe_pmu_start(struct perf_event *event, int flags)
881 {
882 u64 reg;
883 struct arm_spe_pmu *spe_pmu = to_spe_pmu(event->pmu);
884 struct hw_perf_event *hwc = &event->hw;
885 struct perf_output_handle *handle = this_cpu_ptr(spe_pmu->handle);
886
887 hwc->state = 0;
888 if (arm_spe_perf_aux_output_begin(handle, event)) {
889 arm_spe_pmu_stop(event, 0);
890 return;
891 }
892
893 reg = arm_spe_event_to_pmsfcr(event);
894 write_sysreg_s(reg, SYS_PMSFCR_EL1);
895
896 reg = arm_spe_event_to_pmsevfr(event);
897 write_sysreg_s(reg, SYS_PMSEVFR_EL1);
898
899 if (spe_pmu->features & SPE_PMU_FEAT_INV_FILT_EVT) {
900 reg = arm_spe_event_to_pmsnevfr(event);
901 write_sysreg_s(reg, SYS_PMSNEVFR_EL1);
902 }
903
904 if (spe_pmu->features & SPE_PMU_FEAT_FDS) {
905 reg = arm_spe_event_to_pmsdsfr(event);
906 write_sysreg_s(reg, SYS_PMSDSFR_EL1);
907 }
908
909 reg = arm_spe_event_to_pmslatfr(event);
910 write_sysreg_s(reg, SYS_PMSLATFR_EL1);
911
912 if (flags & PERF_EF_RELOAD) {
913 reg = arm_spe_event_to_pmsirr(event);
914 write_sysreg_s(reg, SYS_PMSIRR_EL1);
915 isb();
916 reg = local64_read(&hwc->period_left);
917 write_sysreg_s(reg, SYS_PMSICR_EL1);
918 }
919
920 reg = arm_spe_event_to_pmscr(event);
921 isb();
922 write_sysreg_s(reg, SYS_PMSCR_EL1);
923 }
924
arm_spe_pmu_stop(struct perf_event * event,int flags)925 static void arm_spe_pmu_stop(struct perf_event *event, int flags)
926 {
927 struct arm_spe_pmu *spe_pmu = to_spe_pmu(event->pmu);
928 struct hw_perf_event *hwc = &event->hw;
929 struct perf_output_handle *handle = this_cpu_ptr(spe_pmu->handle);
930
931 /* If we're already stopped, then nothing to do */
932 if (hwc->state & PERF_HES_STOPPED)
933 return;
934
935 /* Stop all trace generation */
936 arm_spe_pmu_disable_and_drain_local();
937
938 if (flags & PERF_EF_UPDATE) {
939 /*
940 * If there's a fault pending then ensure we contain it
941 * to this buffer, since we might be on the context-switch
942 * path.
943 */
944 if (perf_get_aux(handle)) {
945 enum arm_spe_pmu_buf_fault_action act;
946
947 act = arm_spe_pmu_buf_get_fault_act(handle);
948 if (act == SPE_PMU_BUF_FAULT_ACT_SPURIOUS)
949 arm_spe_perf_aux_output_end(handle);
950 else
951 write_sysreg_s(0, SYS_PMBSR_EL1);
952 }
953
954 /*
955 * This may also contain ECOUNT, but nobody else should
956 * be looking at period_left, since we forbid frequency
957 * based sampling.
958 */
959 local64_set(&hwc->period_left, read_sysreg_s(SYS_PMSICR_EL1));
960 hwc->state |= PERF_HES_UPTODATE;
961 }
962
963 hwc->state |= PERF_HES_STOPPED;
964 }
965
arm_spe_pmu_add(struct perf_event * event,int flags)966 static int arm_spe_pmu_add(struct perf_event *event, int flags)
967 {
968 int ret = 0;
969 struct arm_spe_pmu *spe_pmu = to_spe_pmu(event->pmu);
970 struct hw_perf_event *hwc = &event->hw;
971 int cpu = event->cpu == -1 ? smp_processor_id() : event->cpu;
972
973 if (!cpumask_test_cpu(cpu, &spe_pmu->supported_cpus))
974 return -ENOENT;
975
976 hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
977
978 if (flags & PERF_EF_START) {
979 arm_spe_pmu_start(event, PERF_EF_RELOAD);
980 if (hwc->state & PERF_HES_STOPPED)
981 ret = -EINVAL;
982 }
983
984 return ret;
985 }
986
arm_spe_pmu_del(struct perf_event * event,int flags)987 static void arm_spe_pmu_del(struct perf_event *event, int flags)
988 {
989 arm_spe_pmu_stop(event, PERF_EF_UPDATE);
990 }
991
arm_spe_pmu_read(struct perf_event * event)992 static void arm_spe_pmu_read(struct perf_event *event)
993 {
994 }
995
arm_spe_pmu_setup_aux(struct perf_event * event,void ** pages,int nr_pages,bool snapshot)996 static void *arm_spe_pmu_setup_aux(struct perf_event *event, void **pages,
997 int nr_pages, bool snapshot)
998 {
999 int i, cpu = event->cpu;
1000 struct page **pglist;
1001 struct arm_spe_pmu_buf *buf;
1002
1003 /* We need at least two pages for this to work. */
1004 if (nr_pages < 2)
1005 return NULL;
1006
1007 /*
1008 * We require an even number of pages for snapshot mode, so that
1009 * we can effectively treat the buffer as consisting of two equal
1010 * parts and give userspace a fighting chance of getting some
1011 * useful data out of it.
1012 */
1013 if (snapshot && (nr_pages & 1))
1014 return NULL;
1015
1016 if (cpu == -1)
1017 cpu = raw_smp_processor_id();
1018
1019 buf = kzalloc_node(sizeof(*buf), GFP_KERNEL, cpu_to_node(cpu));
1020 if (!buf)
1021 return NULL;
1022
1023 pglist = kzalloc_objs(*pglist, nr_pages);
1024 if (!pglist)
1025 goto out_free_buf;
1026
1027 for (i = 0; i < nr_pages; ++i)
1028 pglist[i] = virt_to_page(pages[i]);
1029
1030 buf->base = vmap(pglist, nr_pages, VM_MAP, PAGE_KERNEL);
1031 if (!buf->base)
1032 goto out_free_pglist;
1033
1034 buf->nr_pages = nr_pages;
1035 buf->snapshot = snapshot;
1036
1037 kfree(pglist);
1038 return buf;
1039
1040 out_free_pglist:
1041 kfree(pglist);
1042 out_free_buf:
1043 kfree(buf);
1044 return NULL;
1045 }
1046
arm_spe_pmu_free_aux(void * aux)1047 static void arm_spe_pmu_free_aux(void *aux)
1048 {
1049 struct arm_spe_pmu_buf *buf = aux;
1050
1051 vunmap(buf->base);
1052 kfree(buf);
1053 }
1054
1055 /* Initialisation and teardown functions */
arm_spe_pmu_perf_init(struct arm_spe_pmu * spe_pmu)1056 static int arm_spe_pmu_perf_init(struct arm_spe_pmu *spe_pmu)
1057 {
1058 static atomic_t pmu_idx = ATOMIC_INIT(-1);
1059
1060 int idx;
1061 char *name;
1062 struct device *dev = &spe_pmu->pdev->dev;
1063
1064 spe_pmu->pmu = (struct pmu) {
1065 .module = THIS_MODULE,
1066 .parent = &spe_pmu->pdev->dev,
1067 .capabilities = PERF_PMU_CAP_EXCLUSIVE | PERF_PMU_CAP_ITRACE,
1068 .attr_groups = arm_spe_pmu_attr_groups,
1069 /*
1070 * We hitch a ride on the software context here, so that
1071 * we can support per-task profiling (which is not possible
1072 * with the invalid context as it doesn't get sched callbacks).
1073 * This requires that userspace either uses a dummy event for
1074 * perf_event_open, since the aux buffer is not setup until
1075 * a subsequent mmap, or creates the profiling event in a
1076 * disabled state and explicitly PERF_EVENT_IOC_ENABLEs it
1077 * once the buffer has been created.
1078 */
1079 .task_ctx_nr = perf_sw_context,
1080 .event_init = arm_spe_pmu_event_init,
1081 .add = arm_spe_pmu_add,
1082 .del = arm_spe_pmu_del,
1083 .start = arm_spe_pmu_start,
1084 .stop = arm_spe_pmu_stop,
1085 .read = arm_spe_pmu_read,
1086 .setup_aux = arm_spe_pmu_setup_aux,
1087 .free_aux = arm_spe_pmu_free_aux,
1088 };
1089
1090 idx = atomic_inc_return(&pmu_idx);
1091 name = devm_kasprintf(dev, GFP_KERNEL, "%s_%d", PMUNAME, idx);
1092 if (!name) {
1093 dev_err(dev, "failed to allocate name for pmu %d\n", idx);
1094 return -ENOMEM;
1095 }
1096
1097 return perf_pmu_register(&spe_pmu->pmu, name, -1);
1098 }
1099
arm_spe_pmu_perf_destroy(struct arm_spe_pmu * spe_pmu)1100 static void arm_spe_pmu_perf_destroy(struct arm_spe_pmu *spe_pmu)
1101 {
1102 perf_pmu_unregister(&spe_pmu->pmu);
1103 }
1104
__arm_spe_pmu_dev_probe(void * info)1105 static void __arm_spe_pmu_dev_probe(void *info)
1106 {
1107 int fld;
1108 u64 reg;
1109 struct arm_spe_pmu *spe_pmu = info;
1110 struct device *dev = &spe_pmu->pdev->dev;
1111
1112 fld = cpuid_feature_extract_unsigned_field(read_cpuid(ID_AA64DFR0_EL1),
1113 ID_AA64DFR0_EL1_PMSVer_SHIFT);
1114 if (!fld) {
1115 dev_err(dev,
1116 "unsupported ID_AA64DFR0_EL1.PMSVer [%d] on CPU %d\n",
1117 fld, smp_processor_id());
1118 return;
1119 }
1120 spe_pmu->pmsver = (u16)fld;
1121
1122 /* Read PMBIDR first to determine whether or not we have access */
1123 reg = read_sysreg_s(SYS_PMBIDR_EL1);
1124 if (FIELD_GET(PMBIDR_EL1_P, reg)) {
1125 dev_err(dev,
1126 "profiling buffer owned by higher exception level\n");
1127 return;
1128 }
1129
1130 /* Minimum alignment. If it's out-of-range, then fail the probe */
1131 fld = FIELD_GET(PMBIDR_EL1_ALIGN, reg);
1132 spe_pmu->align = 1 << fld;
1133 if (spe_pmu->align > SZ_2K) {
1134 dev_err(dev, "unsupported PMBIDR.Align [%d] on CPU %d\n",
1135 fld, smp_processor_id());
1136 return;
1137 }
1138
1139 /* It's now safe to read PMSIDR and figure out what we've got */
1140 reg = read_sysreg_s(SYS_PMSIDR_EL1);
1141 if (FIELD_GET(PMSIDR_EL1_FE, reg))
1142 spe_pmu->features |= SPE_PMU_FEAT_FILT_EVT;
1143
1144 if (FIELD_GET(PMSIDR_EL1_FnE, reg))
1145 spe_pmu->features |= SPE_PMU_FEAT_INV_FILT_EVT;
1146
1147 if (FIELD_GET(PMSIDR_EL1_FT, reg))
1148 spe_pmu->features |= SPE_PMU_FEAT_FILT_TYP;
1149
1150 if (FIELD_GET(PMSIDR_EL1_FL, reg))
1151 spe_pmu->features |= SPE_PMU_FEAT_FILT_LAT;
1152
1153 if (FIELD_GET(PMSIDR_EL1_ARCHINST, reg))
1154 spe_pmu->features |= SPE_PMU_FEAT_ARCH_INST;
1155
1156 if (FIELD_GET(PMSIDR_EL1_LDS, reg))
1157 spe_pmu->features |= SPE_PMU_FEAT_LDS;
1158
1159 if (FIELD_GET(PMSIDR_EL1_ERND, reg))
1160 spe_pmu->features |= SPE_PMU_FEAT_ERND;
1161
1162 if (spe_pmu->pmsver >= ID_AA64DFR0_EL1_PMSVer_V1P2)
1163 spe_pmu->features |= SPE_PMU_FEAT_DISCARD;
1164
1165 if (FIELD_GET(PMSIDR_EL1_EFT, reg))
1166 spe_pmu->features |= SPE_PMU_FEAT_EFT;
1167
1168 if (FIELD_GET(PMSIDR_EL1_FDS, reg))
1169 spe_pmu->features |= SPE_PMU_FEAT_FDS;
1170
1171 /* This field has a spaced out encoding, so just use a look-up */
1172 fld = FIELD_GET(PMSIDR_EL1_INTERVAL, reg);
1173 switch (fld) {
1174 case PMSIDR_EL1_INTERVAL_256:
1175 spe_pmu->min_period = 256;
1176 break;
1177 case PMSIDR_EL1_INTERVAL_512:
1178 spe_pmu->min_period = 512;
1179 break;
1180 case PMSIDR_EL1_INTERVAL_768:
1181 spe_pmu->min_period = 768;
1182 break;
1183 case PMSIDR_EL1_INTERVAL_1024:
1184 spe_pmu->min_period = 1024;
1185 break;
1186 case PMSIDR_EL1_INTERVAL_1536:
1187 spe_pmu->min_period = 1536;
1188 break;
1189 case PMSIDR_EL1_INTERVAL_2048:
1190 spe_pmu->min_period = 2048;
1191 break;
1192 case PMSIDR_EL1_INTERVAL_3072:
1193 spe_pmu->min_period = 3072;
1194 break;
1195 default:
1196 dev_warn(dev, "unknown PMSIDR_EL1.Interval [%d]; assuming 8\n",
1197 fld);
1198 fallthrough;
1199 case PMSIDR_EL1_INTERVAL_4096:
1200 spe_pmu->min_period = 4096;
1201 }
1202
1203 /* Maximum record size. If it's out-of-range, then fail the probe */
1204 fld = FIELD_GET(PMSIDR_EL1_MAXSIZE, reg);
1205 spe_pmu->max_record_sz = 1 << fld;
1206 if (spe_pmu->max_record_sz > SZ_2K || spe_pmu->max_record_sz < 16) {
1207 dev_err(dev, "unsupported PMSIDR_EL1.MaxSize [%d] on CPU %d\n",
1208 fld, smp_processor_id());
1209 return;
1210 }
1211
1212 fld = FIELD_GET(PMSIDR_EL1_COUNTSIZE, reg);
1213 switch (fld) {
1214 default:
1215 dev_warn(dev, "unknown PMSIDR_EL1.CountSize [%d]; assuming 2\n",
1216 fld);
1217 fallthrough;
1218 case PMSIDR_EL1_COUNTSIZE_12_BIT_SAT:
1219 spe_pmu->counter_sz = 12;
1220 break;
1221 case PMSIDR_EL1_COUNTSIZE_16_BIT_SAT:
1222 spe_pmu->counter_sz = 16;
1223 }
1224
1225 /* Write all 1s and then read back. Unsupported filter bits are RAZ/WI. */
1226 write_sysreg_s(U64_MAX, SYS_PMSEVFR_EL1);
1227 spe_pmu->pmsevfr_res0 = ~read_sysreg_s(SYS_PMSEVFR_EL1);
1228
1229 dev_info(dev,
1230 "probed SPEv1.%d for CPUs %*pbl [max_record_sz %u, align %u, features 0x%llx]\n",
1231 spe_pmu->pmsver - 1, cpumask_pr_args(&spe_pmu->supported_cpus),
1232 spe_pmu->max_record_sz, spe_pmu->align, spe_pmu->features);
1233
1234 spe_pmu->features |= SPE_PMU_FEAT_DEV_PROBED;
1235 }
1236
__arm_spe_pmu_reset_local(void)1237 static void __arm_spe_pmu_reset_local(void)
1238 {
1239 /*
1240 * This is probably overkill, as we have no idea where we're
1241 * draining any buffered data to...
1242 */
1243 arm_spe_pmu_disable_and_drain_local();
1244
1245 /* Reset the buffer base pointer */
1246 write_sysreg_s(0, SYS_PMBPTR_EL1);
1247 isb();
1248
1249 /* Clear any pending management interrupts */
1250 write_sysreg_s(0, SYS_PMBSR_EL1);
1251 isb();
1252 }
1253
__arm_spe_pmu_setup_one(void * info)1254 static void __arm_spe_pmu_setup_one(void *info)
1255 {
1256 struct arm_spe_pmu *spe_pmu = info;
1257
1258 __arm_spe_pmu_reset_local();
1259 enable_percpu_irq(spe_pmu->irq, IRQ_TYPE_NONE);
1260 }
1261
__arm_spe_pmu_stop_one(void * info)1262 static void __arm_spe_pmu_stop_one(void *info)
1263 {
1264 struct arm_spe_pmu *spe_pmu = info;
1265
1266 disable_percpu_irq(spe_pmu->irq);
1267 __arm_spe_pmu_reset_local();
1268 }
1269
arm_spe_pmu_cpu_startup(unsigned int cpu,struct hlist_node * node)1270 static int arm_spe_pmu_cpu_startup(unsigned int cpu, struct hlist_node *node)
1271 {
1272 struct arm_spe_pmu *spe_pmu;
1273
1274 spe_pmu = hlist_entry_safe(node, struct arm_spe_pmu, hotplug_node);
1275 if (!cpumask_test_cpu(cpu, &spe_pmu->supported_cpus))
1276 return 0;
1277
1278 __arm_spe_pmu_setup_one(spe_pmu);
1279 return 0;
1280 }
1281
arm_spe_pmu_cpu_teardown(unsigned int cpu,struct hlist_node * node)1282 static int arm_spe_pmu_cpu_teardown(unsigned int cpu, struct hlist_node *node)
1283 {
1284 struct arm_spe_pmu *spe_pmu;
1285
1286 spe_pmu = hlist_entry_safe(node, struct arm_spe_pmu, hotplug_node);
1287 if (!cpumask_test_cpu(cpu, &spe_pmu->supported_cpus))
1288 return 0;
1289
1290 __arm_spe_pmu_stop_one(spe_pmu);
1291 return 0;
1292 }
1293
arm_spe_pmu_dev_init(struct arm_spe_pmu * spe_pmu)1294 static int arm_spe_pmu_dev_init(struct arm_spe_pmu *spe_pmu)
1295 {
1296 int ret;
1297 cpumask_t *mask = &spe_pmu->supported_cpus;
1298
1299 /* Make sure we probe the hardware on a relevant CPU */
1300 ret = smp_call_function_any(mask, __arm_spe_pmu_dev_probe, spe_pmu, 1);
1301 if (ret || !(spe_pmu->features & SPE_PMU_FEAT_DEV_PROBED))
1302 return -ENXIO;
1303
1304 /* Request our PPIs (note that the IRQ is still disabled) */
1305 ret = request_percpu_irq_affinity(spe_pmu->irq, arm_spe_pmu_irq_handler,
1306 DRVNAME, mask, spe_pmu->handle);
1307 if (ret)
1308 return ret;
1309
1310 /*
1311 * Register our hotplug notifier now so we don't miss any events.
1312 * This will enable the IRQ for any supported CPUs that are already
1313 * up.
1314 */
1315 ret = cpuhp_state_add_instance(arm_spe_pmu_online,
1316 &spe_pmu->hotplug_node);
1317 if (ret)
1318 free_percpu_irq(spe_pmu->irq, spe_pmu->handle);
1319
1320 return ret;
1321 }
1322
arm_spe_pmu_dev_teardown(struct arm_spe_pmu * spe_pmu)1323 static void arm_spe_pmu_dev_teardown(struct arm_spe_pmu *spe_pmu)
1324 {
1325 cpuhp_state_remove_instance(arm_spe_pmu_online, &spe_pmu->hotplug_node);
1326 free_percpu_irq(spe_pmu->irq, spe_pmu->handle);
1327 }
1328
1329 /* Driver and device probing */
arm_spe_pmu_irq_probe(struct arm_spe_pmu * spe_pmu)1330 static int arm_spe_pmu_irq_probe(struct arm_spe_pmu *spe_pmu)
1331 {
1332 struct platform_device *pdev = spe_pmu->pdev;
1333 const struct cpumask *affinity;
1334 int irq;
1335
1336 irq = platform_get_irq_affinity(pdev, 0, &affinity);
1337 if (irq < 0)
1338 return -ENXIO;
1339
1340 if (!irq_is_percpu(irq)) {
1341 dev_err(&pdev->dev, "expected PPI but got SPI (%d)\n", irq);
1342 return -EINVAL;
1343 }
1344
1345 cpumask_copy(&spe_pmu->supported_cpus, affinity);
1346
1347 spe_pmu->irq = irq;
1348 return 0;
1349 }
1350
1351 static const struct of_device_id arm_spe_pmu_of_match[] = {
1352 { .compatible = "arm,statistical-profiling-extension-v1", .data = (void *)1 },
1353 { /* Sentinel */ },
1354 };
1355 MODULE_DEVICE_TABLE(of, arm_spe_pmu_of_match);
1356
1357 static const struct platform_device_id arm_spe_match[] = {
1358 { ARMV8_SPE_PDEV_NAME, 0},
1359 { }
1360 };
1361 MODULE_DEVICE_TABLE(platform, arm_spe_match);
1362
arm_spe_pmu_device_probe(struct platform_device * pdev)1363 static int arm_spe_pmu_device_probe(struct platform_device *pdev)
1364 {
1365 int ret;
1366 struct arm_spe_pmu *spe_pmu;
1367 struct device *dev = &pdev->dev;
1368
1369 /*
1370 * If kernelspace is unmapped when running at EL0, then the SPE
1371 * buffer will fault and prematurely terminate the AUX session.
1372 */
1373 if (arm64_kernel_unmapped_at_el0()) {
1374 dev_warn_once(dev, "profiling buffer inaccessible. Try passing \"kpti=off\" on the kernel command line\n");
1375 return -EPERM;
1376 }
1377
1378 spe_pmu = devm_kzalloc(dev, sizeof(*spe_pmu), GFP_KERNEL);
1379 if (!spe_pmu)
1380 return -ENOMEM;
1381
1382 spe_pmu->handle = alloc_percpu(typeof(*spe_pmu->handle));
1383 if (!spe_pmu->handle)
1384 return -ENOMEM;
1385
1386 spe_pmu->pdev = pdev;
1387 platform_set_drvdata(pdev, spe_pmu);
1388
1389 ret = arm_spe_pmu_irq_probe(spe_pmu);
1390 if (ret)
1391 goto out_free_handle;
1392
1393 ret = arm_spe_pmu_dev_init(spe_pmu);
1394 if (ret)
1395 goto out_free_handle;
1396
1397 ret = arm_spe_pmu_perf_init(spe_pmu);
1398 if (ret)
1399 goto out_teardown_dev;
1400
1401 return 0;
1402
1403 out_teardown_dev:
1404 arm_spe_pmu_dev_teardown(spe_pmu);
1405 out_free_handle:
1406 free_percpu(spe_pmu->handle);
1407 return ret;
1408 }
1409
arm_spe_pmu_device_remove(struct platform_device * pdev)1410 static void arm_spe_pmu_device_remove(struct platform_device *pdev)
1411 {
1412 struct arm_spe_pmu *spe_pmu = platform_get_drvdata(pdev);
1413
1414 arm_spe_pmu_perf_destroy(spe_pmu);
1415 arm_spe_pmu_dev_teardown(spe_pmu);
1416 free_percpu(spe_pmu->handle);
1417 }
1418
1419 static struct platform_driver arm_spe_pmu_driver = {
1420 .id_table = arm_spe_match,
1421 .driver = {
1422 .name = DRVNAME,
1423 .of_match_table = of_match_ptr(arm_spe_pmu_of_match),
1424 .suppress_bind_attrs = true,
1425 },
1426 .probe = arm_spe_pmu_device_probe,
1427 .remove = arm_spe_pmu_device_remove,
1428 };
1429
arm_spe_pmu_init(void)1430 static int __init arm_spe_pmu_init(void)
1431 {
1432 int ret;
1433
1434 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, DRVNAME,
1435 arm_spe_pmu_cpu_startup,
1436 arm_spe_pmu_cpu_teardown);
1437 if (ret < 0)
1438 return ret;
1439 arm_spe_pmu_online = ret;
1440
1441 ret = platform_driver_register(&arm_spe_pmu_driver);
1442 if (ret)
1443 cpuhp_remove_multi_state(arm_spe_pmu_online);
1444
1445 return ret;
1446 }
1447
arm_spe_pmu_exit(void)1448 static void __exit arm_spe_pmu_exit(void)
1449 {
1450 platform_driver_unregister(&arm_spe_pmu_driver);
1451 cpuhp_remove_multi_state(arm_spe_pmu_online);
1452 }
1453
1454 module_init(arm_spe_pmu_init);
1455 module_exit(arm_spe_pmu_exit);
1456
1457 MODULE_DESCRIPTION("Perf driver for the ARMv8.2 Statistical Profiling Extension");
1458 MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
1459 MODULE_LICENSE("GPL v2");
1460