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TOMOYO Linux Cross Reference
Linux/arch/x86/events/core.c

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  1 /*
  2  * Performance events x86 architecture code
  3  *
  4  *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
  5  *  Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
  6  *  Copyright (C) 2009 Jaswinder Singh Rajput
  7  *  Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter
  8  *  Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra
  9  *  Copyright (C) 2009 Intel Corporation, <markus.t.metzger@intel.com>
 10  *  Copyright (C) 2009 Google, Inc., Stephane Eranian
 11  *
 12  *  For licencing details see kernel-base/COPYING
 13  */
 14 
 15 #include <linux/perf_event.h>
 16 #include <linux/capability.h>
 17 #include <linux/notifier.h>
 18 #include <linux/hardirq.h>
 19 #include <linux/kprobes.h>
 20 #include <linux/export.h>
 21 #include <linux/init.h>
 22 #include <linux/kdebug.h>
 23 #include <linux/sched/mm.h>
 24 #include <linux/sched/clock.h>
 25 #include <linux/uaccess.h>
 26 #include <linux/slab.h>
 27 #include <linux/cpu.h>
 28 #include <linux/bitops.h>
 29 #include <linux/device.h>
 30 #include <linux/nospec.h>
 31 #include <linux/static_call.h>
 32 
 33 #include <asm/apic.h>
 34 #include <asm/stacktrace.h>
 35 #include <asm/nmi.h>
 36 #include <asm/smp.h>
 37 #include <asm/alternative.h>
 38 #include <asm/mmu_context.h>
 39 #include <asm/tlbflush.h>
 40 #include <asm/timer.h>
 41 #include <asm/desc.h>
 42 #include <asm/ldt.h>
 43 #include <asm/unwind.h>
 44 
 45 #include "perf_event.h"
 46 
 47 struct x86_pmu x86_pmu __read_mostly;
 48 static struct pmu pmu;
 49 
 50 DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = {
 51         .enabled = 1,
 52         .pmu = &pmu,
 53 };
 54 
 55 DEFINE_STATIC_KEY_FALSE(rdpmc_never_available_key);
 56 DEFINE_STATIC_KEY_FALSE(rdpmc_always_available_key);
 57 DEFINE_STATIC_KEY_FALSE(perf_is_hybrid);
 58 
 59 /*
 60  * This here uses DEFINE_STATIC_CALL_NULL() to get a static_call defined
 61  * from just a typename, as opposed to an actual function.
 62  */
 63 DEFINE_STATIC_CALL_NULL(x86_pmu_handle_irq,  *x86_pmu.handle_irq);
 64 DEFINE_STATIC_CALL_NULL(x86_pmu_disable_all, *x86_pmu.disable_all);
 65 DEFINE_STATIC_CALL_NULL(x86_pmu_enable_all,  *x86_pmu.enable_all);
 66 DEFINE_STATIC_CALL_NULL(x86_pmu_enable,      *x86_pmu.enable);
 67 DEFINE_STATIC_CALL_NULL(x86_pmu_disable,     *x86_pmu.disable);
 68 
 69 DEFINE_STATIC_CALL_NULL(x86_pmu_assign, *x86_pmu.assign);
 70 
 71 DEFINE_STATIC_CALL_NULL(x86_pmu_add,  *x86_pmu.add);
 72 DEFINE_STATIC_CALL_NULL(x86_pmu_del,  *x86_pmu.del);
 73 DEFINE_STATIC_CALL_NULL(x86_pmu_read, *x86_pmu.read);
 74 
 75 DEFINE_STATIC_CALL_NULL(x86_pmu_set_period,   *x86_pmu.set_period);
 76 DEFINE_STATIC_CALL_NULL(x86_pmu_update,       *x86_pmu.update);
 77 DEFINE_STATIC_CALL_NULL(x86_pmu_limit_period, *x86_pmu.limit_period);
 78 
 79 DEFINE_STATIC_CALL_NULL(x86_pmu_schedule_events,       *x86_pmu.schedule_events);
 80 DEFINE_STATIC_CALL_NULL(x86_pmu_get_event_constraints, *x86_pmu.get_event_constraints);
 81 DEFINE_STATIC_CALL_NULL(x86_pmu_put_event_constraints, *x86_pmu.put_event_constraints);
 82 
 83 DEFINE_STATIC_CALL_NULL(x86_pmu_start_scheduling,  *x86_pmu.start_scheduling);
 84 DEFINE_STATIC_CALL_NULL(x86_pmu_commit_scheduling, *x86_pmu.commit_scheduling);
 85 DEFINE_STATIC_CALL_NULL(x86_pmu_stop_scheduling,   *x86_pmu.stop_scheduling);
 86 
 87 DEFINE_STATIC_CALL_NULL(x86_pmu_sched_task,    *x86_pmu.sched_task);
 88 DEFINE_STATIC_CALL_NULL(x86_pmu_swap_task_ctx, *x86_pmu.swap_task_ctx);
 89 
 90 DEFINE_STATIC_CALL_NULL(x86_pmu_drain_pebs,   *x86_pmu.drain_pebs);
 91 DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_aliases, *x86_pmu.pebs_aliases);
 92 
 93 DEFINE_STATIC_CALL_NULL(x86_pmu_filter, *x86_pmu.filter);
 94 
 95 /*
 96  * This one is magic, it will get called even when PMU init fails (because
 97  * there is no PMU), in which case it should simply return NULL.
 98  */
 99 DEFINE_STATIC_CALL_RET0(x86_pmu_guest_get_msrs, *x86_pmu.guest_get_msrs);
100 
101 u64 __read_mostly hw_cache_event_ids
102                                 [PERF_COUNT_HW_CACHE_MAX]
103                                 [PERF_COUNT_HW_CACHE_OP_MAX]
104                                 [PERF_COUNT_HW_CACHE_RESULT_MAX];
105 u64 __read_mostly hw_cache_extra_regs
106                                 [PERF_COUNT_HW_CACHE_MAX]
107                                 [PERF_COUNT_HW_CACHE_OP_MAX]
108                                 [PERF_COUNT_HW_CACHE_RESULT_MAX];
109 
110 /*
111  * Propagate event elapsed time into the generic event.
112  * Can only be executed on the CPU where the event is active.
113  * Returns the delta events processed.
114  */
115 u64 x86_perf_event_update(struct perf_event *event)
116 {
117         struct hw_perf_event *hwc = &event->hw;
118         int shift = 64 - x86_pmu.cntval_bits;
119         u64 prev_raw_count, new_raw_count;
120         u64 delta;
121 
122         if (unlikely(!hwc->event_base))
123                 return 0;
124 
125         /*
126          * Careful: an NMI might modify the previous event value.
127          *
128          * Our tactic to handle this is to first atomically read and
129          * exchange a new raw count - then add that new-prev delta
130          * count to the generic event atomically:
131          */
132         prev_raw_count = local64_read(&hwc->prev_count);
133         do {
134                 rdpmcl(hwc->event_base_rdpmc, new_raw_count);
135         } while (!local64_try_cmpxchg(&hwc->prev_count,
136                                       &prev_raw_count, new_raw_count));
137 
138         /*
139          * Now we have the new raw value and have updated the prev
140          * timestamp already. We can now calculate the elapsed delta
141          * (event-)time and add that to the generic event.
142          *
143          * Careful, not all hw sign-extends above the physical width
144          * of the count.
145          */
146         delta = (new_raw_count << shift) - (prev_raw_count << shift);
147         delta >>= shift;
148 
149         local64_add(delta, &event->count);
150         local64_sub(delta, &hwc->period_left);
151 
152         return new_raw_count;
153 }
154 
155 /*
156  * Find and validate any extra registers to set up.
157  */
158 static int x86_pmu_extra_regs(u64 config, struct perf_event *event)
159 {
160         struct extra_reg *extra_regs = hybrid(event->pmu, extra_regs);
161         struct hw_perf_event_extra *reg;
162         struct extra_reg *er;
163 
164         reg = &event->hw.extra_reg;
165 
166         if (!extra_regs)
167                 return 0;
168 
169         for (er = extra_regs; er->msr; er++) {
170                 if (er->event != (config & er->config_mask))
171                         continue;
172                 if (event->attr.config1 & ~er->valid_mask)
173                         return -EINVAL;
174                 /* Check if the extra msrs can be safely accessed*/
175                 if (!er->extra_msr_access)
176                         return -ENXIO;
177 
178                 reg->idx = er->idx;
179                 reg->config = event->attr.config1;
180                 reg->reg = er->msr;
181                 break;
182         }
183         return 0;
184 }
185 
186 static atomic_t active_events;
187 static atomic_t pmc_refcount;
188 static DEFINE_MUTEX(pmc_reserve_mutex);
189 
190 #ifdef CONFIG_X86_LOCAL_APIC
191 
192 static inline u64 get_possible_counter_mask(void)
193 {
194         u64 cntr_mask = x86_pmu.cntr_mask64;
195         int i;
196 
197         if (!is_hybrid())
198                 return cntr_mask;
199 
200         for (i = 0; i < x86_pmu.num_hybrid_pmus; i++)
201                 cntr_mask |= x86_pmu.hybrid_pmu[i].cntr_mask64;
202 
203         return cntr_mask;
204 }
205 
206 static bool reserve_pmc_hardware(void)
207 {
208         u64 cntr_mask = get_possible_counter_mask();
209         int i, end;
210 
211         for_each_set_bit(i, (unsigned long *)&cntr_mask, X86_PMC_IDX_MAX) {
212                 if (!reserve_perfctr_nmi(x86_pmu_event_addr(i)))
213                         goto perfctr_fail;
214         }
215 
216         for_each_set_bit(i, (unsigned long *)&cntr_mask, X86_PMC_IDX_MAX) {
217                 if (!reserve_evntsel_nmi(x86_pmu_config_addr(i)))
218                         goto eventsel_fail;
219         }
220 
221         return true;
222 
223 eventsel_fail:
224         end = i;
225         for_each_set_bit(i, (unsigned long *)&cntr_mask, end)
226                 release_evntsel_nmi(x86_pmu_config_addr(i));
227         i = X86_PMC_IDX_MAX;
228 
229 perfctr_fail:
230         end = i;
231         for_each_set_bit(i, (unsigned long *)&cntr_mask, end)
232                 release_perfctr_nmi(x86_pmu_event_addr(i));
233 
234         return false;
235 }
236 
237 static void release_pmc_hardware(void)
238 {
239         u64 cntr_mask = get_possible_counter_mask();
240         int i;
241 
242         for_each_set_bit(i, (unsigned long *)&cntr_mask, X86_PMC_IDX_MAX) {
243                 release_perfctr_nmi(x86_pmu_event_addr(i));
244                 release_evntsel_nmi(x86_pmu_config_addr(i));
245         }
246 }
247 
248 #else
249 
250 static bool reserve_pmc_hardware(void) { return true; }
251 static void release_pmc_hardware(void) {}
252 
253 #endif
254 
255 bool check_hw_exists(struct pmu *pmu, unsigned long *cntr_mask,
256                      unsigned long *fixed_cntr_mask)
257 {
258         u64 val, val_fail = -1, val_new= ~0;
259         int i, reg, reg_fail = -1, ret = 0;
260         int bios_fail = 0;
261         int reg_safe = -1;
262 
263         /*
264          * Check to see if the BIOS enabled any of the counters, if so
265          * complain and bail.
266          */
267         for_each_set_bit(i, cntr_mask, X86_PMC_IDX_MAX) {
268                 reg = x86_pmu_config_addr(i);
269                 ret = rdmsrl_safe(reg, &val);
270                 if (ret)
271                         goto msr_fail;
272                 if (val & ARCH_PERFMON_EVENTSEL_ENABLE) {
273                         bios_fail = 1;
274                         val_fail = val;
275                         reg_fail = reg;
276                 } else {
277                         reg_safe = i;
278                 }
279         }
280 
281         if (*(u64 *)fixed_cntr_mask) {
282                 reg = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
283                 ret = rdmsrl_safe(reg, &val);
284                 if (ret)
285                         goto msr_fail;
286                 for_each_set_bit(i, fixed_cntr_mask, X86_PMC_IDX_MAX) {
287                         if (fixed_counter_disabled(i, pmu))
288                                 continue;
289                         if (val & (0x03ULL << i*4)) {
290                                 bios_fail = 1;
291                                 val_fail = val;
292                                 reg_fail = reg;
293                         }
294                 }
295         }
296 
297         /*
298          * If all the counters are enabled, the below test will always
299          * fail.  The tools will also become useless in this scenario.
300          * Just fail and disable the hardware counters.
301          */
302 
303         if (reg_safe == -1) {
304                 reg = reg_safe;
305                 goto msr_fail;
306         }
307 
308         /*
309          * Read the current value, change it and read it back to see if it
310          * matches, this is needed to detect certain hardware emulators
311          * (qemu/kvm) that don't trap on the MSR access and always return 0s.
312          */
313         reg = x86_pmu_event_addr(reg_safe);
314         if (rdmsrl_safe(reg, &val))
315                 goto msr_fail;
316         val ^= 0xffffUL;
317         ret = wrmsrl_safe(reg, val);
318         ret |= rdmsrl_safe(reg, &val_new);
319         if (ret || val != val_new)
320                 goto msr_fail;
321 
322         /*
323          * We still allow the PMU driver to operate:
324          */
325         if (bios_fail) {
326                 pr_cont("Broken BIOS detected, complain to your hardware vendor.\n");
327                 pr_err(FW_BUG "the BIOS has corrupted hw-PMU resources (MSR %x is %Lx)\n",
328                               reg_fail, val_fail);
329         }
330 
331         return true;
332 
333 msr_fail:
334         if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
335                 pr_cont("PMU not available due to virtualization, using software events only.\n");
336         } else {
337                 pr_cont("Broken PMU hardware detected, using software events only.\n");
338                 pr_err("Failed to access perfctr msr (MSR %x is %Lx)\n",
339                        reg, val_new);
340         }
341 
342         return false;
343 }
344 
345 static void hw_perf_event_destroy(struct perf_event *event)
346 {
347         x86_release_hardware();
348         atomic_dec(&active_events);
349 }
350 
351 void hw_perf_lbr_event_destroy(struct perf_event *event)
352 {
353         hw_perf_event_destroy(event);
354 
355         /* undo the lbr/bts event accounting */
356         x86_del_exclusive(x86_lbr_exclusive_lbr);
357 }
358 
359 static inline int x86_pmu_initialized(void)
360 {
361         return x86_pmu.handle_irq != NULL;
362 }
363 
364 static inline int
365 set_ext_hw_attr(struct hw_perf_event *hwc, struct perf_event *event)
366 {
367         struct perf_event_attr *attr = &event->attr;
368         unsigned int cache_type, cache_op, cache_result;
369         u64 config, val;
370 
371         config = attr->config;
372 
373         cache_type = (config >> 0) & 0xff;
374         if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
375                 return -EINVAL;
376         cache_type = array_index_nospec(cache_type, PERF_COUNT_HW_CACHE_MAX);
377 
378         cache_op = (config >>  8) & 0xff;
379         if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
380                 return -EINVAL;
381         cache_op = array_index_nospec(cache_op, PERF_COUNT_HW_CACHE_OP_MAX);
382 
383         cache_result = (config >> 16) & 0xff;
384         if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
385                 return -EINVAL;
386         cache_result = array_index_nospec(cache_result, PERF_COUNT_HW_CACHE_RESULT_MAX);
387 
388         val = hybrid_var(event->pmu, hw_cache_event_ids)[cache_type][cache_op][cache_result];
389         if (val == 0)
390                 return -ENOENT;
391 
392         if (val == -1)
393                 return -EINVAL;
394 
395         hwc->config |= val;
396         attr->config1 = hybrid_var(event->pmu, hw_cache_extra_regs)[cache_type][cache_op][cache_result];
397         return x86_pmu_extra_regs(val, event);
398 }
399 
400 int x86_reserve_hardware(void)
401 {
402         int err = 0;
403 
404         if (!atomic_inc_not_zero(&pmc_refcount)) {
405                 mutex_lock(&pmc_reserve_mutex);
406                 if (atomic_read(&pmc_refcount) == 0) {
407                         if (!reserve_pmc_hardware()) {
408                                 err = -EBUSY;
409                         } else {
410                                 reserve_ds_buffers();
411                                 reserve_lbr_buffers();
412                         }
413                 }
414                 if (!err)
415                         atomic_inc(&pmc_refcount);
416                 mutex_unlock(&pmc_reserve_mutex);
417         }
418 
419         return err;
420 }
421 
422 void x86_release_hardware(void)
423 {
424         if (atomic_dec_and_mutex_lock(&pmc_refcount, &pmc_reserve_mutex)) {
425                 release_pmc_hardware();
426                 release_ds_buffers();
427                 release_lbr_buffers();
428                 mutex_unlock(&pmc_reserve_mutex);
429         }
430 }
431 
432 /*
433  * Check if we can create event of a certain type (that no conflicting events
434  * are present).
435  */
436 int x86_add_exclusive(unsigned int what)
437 {
438         int i;
439 
440         /*
441          * When lbr_pt_coexist we allow PT to coexist with either LBR or BTS.
442          * LBR and BTS are still mutually exclusive.
443          */
444         if (x86_pmu.lbr_pt_coexist && what == x86_lbr_exclusive_pt)
445                 goto out;
446 
447         if (!atomic_inc_not_zero(&x86_pmu.lbr_exclusive[what])) {
448                 mutex_lock(&pmc_reserve_mutex);
449                 for (i = 0; i < ARRAY_SIZE(x86_pmu.lbr_exclusive); i++) {
450                         if (i != what && atomic_read(&x86_pmu.lbr_exclusive[i]))
451                                 goto fail_unlock;
452                 }
453                 atomic_inc(&x86_pmu.lbr_exclusive[what]);
454                 mutex_unlock(&pmc_reserve_mutex);
455         }
456 
457 out:
458         atomic_inc(&active_events);
459         return 0;
460 
461 fail_unlock:
462         mutex_unlock(&pmc_reserve_mutex);
463         return -EBUSY;
464 }
465 
466 void x86_del_exclusive(unsigned int what)
467 {
468         atomic_dec(&active_events);
469 
470         /*
471          * See the comment in x86_add_exclusive().
472          */
473         if (x86_pmu.lbr_pt_coexist && what == x86_lbr_exclusive_pt)
474                 return;
475 
476         atomic_dec(&x86_pmu.lbr_exclusive[what]);
477 }
478 
479 int x86_setup_perfctr(struct perf_event *event)
480 {
481         struct perf_event_attr *attr = &event->attr;
482         struct hw_perf_event *hwc = &event->hw;
483         u64 config;
484 
485         if (!is_sampling_event(event)) {
486                 hwc->sample_period = x86_pmu.max_period;
487                 hwc->last_period = hwc->sample_period;
488                 local64_set(&hwc->period_left, hwc->sample_period);
489         }
490 
491         if (attr->type == event->pmu->type)
492                 return x86_pmu_extra_regs(event->attr.config, event);
493 
494         if (attr->type == PERF_TYPE_HW_CACHE)
495                 return set_ext_hw_attr(hwc, event);
496 
497         if (attr->config >= x86_pmu.max_events)
498                 return -EINVAL;
499 
500         attr->config = array_index_nospec((unsigned long)attr->config, x86_pmu.max_events);
501 
502         /*
503          * The generic map:
504          */
505         config = x86_pmu.event_map(attr->config);
506 
507         if (config == 0)
508                 return -ENOENT;
509 
510         if (config == -1LL)
511                 return -EINVAL;
512 
513         hwc->config |= config;
514 
515         return 0;
516 }
517 
518 /*
519  * check that branch_sample_type is compatible with
520  * settings needed for precise_ip > 1 which implies
521  * using the LBR to capture ALL taken branches at the
522  * priv levels of the measurement
523  */
524 static inline int precise_br_compat(struct perf_event *event)
525 {
526         u64 m = event->attr.branch_sample_type;
527         u64 b = 0;
528 
529         /* must capture all branches */
530         if (!(m & PERF_SAMPLE_BRANCH_ANY))
531                 return 0;
532 
533         m &= PERF_SAMPLE_BRANCH_KERNEL | PERF_SAMPLE_BRANCH_USER;
534 
535         if (!event->attr.exclude_user)
536                 b |= PERF_SAMPLE_BRANCH_USER;
537 
538         if (!event->attr.exclude_kernel)
539                 b |= PERF_SAMPLE_BRANCH_KERNEL;
540 
541         /*
542          * ignore PERF_SAMPLE_BRANCH_HV, not supported on x86
543          */
544 
545         return m == b;
546 }
547 
548 int x86_pmu_max_precise(void)
549 {
550         int precise = 0;
551 
552         /* Support for constant skid */
553         if (x86_pmu.pebs_active && !x86_pmu.pebs_broken) {
554                 precise++;
555 
556                 /* Support for IP fixup */
557                 if (x86_pmu.lbr_nr || x86_pmu.intel_cap.pebs_format >= 2)
558                         precise++;
559 
560                 if (x86_pmu.pebs_prec_dist)
561                         precise++;
562         }
563         return precise;
564 }
565 
566 int x86_pmu_hw_config(struct perf_event *event)
567 {
568         if (event->attr.precise_ip) {
569                 int precise = x86_pmu_max_precise();
570 
571                 if (event->attr.precise_ip > precise)
572                         return -EOPNOTSUPP;
573 
574                 /* There's no sense in having PEBS for non sampling events: */
575                 if (!is_sampling_event(event))
576                         return -EINVAL;
577         }
578         /*
579          * check that PEBS LBR correction does not conflict with
580          * whatever the user is asking with attr->branch_sample_type
581          */
582         if (event->attr.precise_ip > 1 && x86_pmu.intel_cap.pebs_format < 2) {
583                 u64 *br_type = &event->attr.branch_sample_type;
584 
585                 if (has_branch_stack(event)) {
586                         if (!precise_br_compat(event))
587                                 return -EOPNOTSUPP;
588 
589                         /* branch_sample_type is compatible */
590 
591                 } else {
592                         /*
593                          * user did not specify  branch_sample_type
594                          *
595                          * For PEBS fixups, we capture all
596                          * the branches at the priv level of the
597                          * event.
598                          */
599                         *br_type = PERF_SAMPLE_BRANCH_ANY;
600 
601                         if (!event->attr.exclude_user)
602                                 *br_type |= PERF_SAMPLE_BRANCH_USER;
603 
604                         if (!event->attr.exclude_kernel)
605                                 *br_type |= PERF_SAMPLE_BRANCH_KERNEL;
606                 }
607         }
608 
609         if (branch_sample_call_stack(event))
610                 event->attach_state |= PERF_ATTACH_TASK_DATA;
611 
612         /*
613          * Generate PMC IRQs:
614          * (keep 'enabled' bit clear for now)
615          */
616         event->hw.config = ARCH_PERFMON_EVENTSEL_INT;
617 
618         /*
619          * Count user and OS events unless requested not to
620          */
621         if (!event->attr.exclude_user)
622                 event->hw.config |= ARCH_PERFMON_EVENTSEL_USR;
623         if (!event->attr.exclude_kernel)
624                 event->hw.config |= ARCH_PERFMON_EVENTSEL_OS;
625 
626         if (event->attr.type == event->pmu->type)
627                 event->hw.config |= x86_pmu_get_event_config(event);
628 
629         if (event->attr.sample_period && x86_pmu.limit_period) {
630                 s64 left = event->attr.sample_period;
631                 x86_pmu.limit_period(event, &left);
632                 if (left > event->attr.sample_period)
633                         return -EINVAL;
634         }
635 
636         /* sample_regs_user never support XMM registers */
637         if (unlikely(event->attr.sample_regs_user & PERF_REG_EXTENDED_MASK))
638                 return -EINVAL;
639         /*
640          * Besides the general purpose registers, XMM registers may
641          * be collected in PEBS on some platforms, e.g. Icelake
642          */
643         if (unlikely(event->attr.sample_regs_intr & PERF_REG_EXTENDED_MASK)) {
644                 if (!(event->pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS))
645                         return -EINVAL;
646 
647                 if (!event->attr.precise_ip)
648                         return -EINVAL;
649         }
650 
651         return x86_setup_perfctr(event);
652 }
653 
654 /*
655  * Setup the hardware configuration for a given attr_type
656  */
657 static int __x86_pmu_event_init(struct perf_event *event)
658 {
659         int err;
660 
661         if (!x86_pmu_initialized())
662                 return -ENODEV;
663 
664         err = x86_reserve_hardware();
665         if (err)
666                 return err;
667 
668         atomic_inc(&active_events);
669         event->destroy = hw_perf_event_destroy;
670 
671         event->hw.idx = -1;
672         event->hw.last_cpu = -1;
673         event->hw.last_tag = ~0ULL;
674 
675         /* mark unused */
676         event->hw.extra_reg.idx = EXTRA_REG_NONE;
677         event->hw.branch_reg.idx = EXTRA_REG_NONE;
678 
679         return x86_pmu.hw_config(event);
680 }
681 
682 void x86_pmu_disable_all(void)
683 {
684         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
685         int idx;
686 
687         for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) {
688                 struct hw_perf_event *hwc = &cpuc->events[idx]->hw;
689                 u64 val;
690 
691                 if (!test_bit(idx, cpuc->active_mask))
692                         continue;
693                 rdmsrl(x86_pmu_config_addr(idx), val);
694                 if (!(val & ARCH_PERFMON_EVENTSEL_ENABLE))
695                         continue;
696                 val &= ~ARCH_PERFMON_EVENTSEL_ENABLE;
697                 wrmsrl(x86_pmu_config_addr(idx), val);
698                 if (is_counter_pair(hwc))
699                         wrmsrl(x86_pmu_config_addr(idx + 1), 0);
700         }
701 }
702 
703 struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr, void *data)
704 {
705         return static_call(x86_pmu_guest_get_msrs)(nr, data);
706 }
707 EXPORT_SYMBOL_GPL(perf_guest_get_msrs);
708 
709 /*
710  * There may be PMI landing after enabled=0. The PMI hitting could be before or
711  * after disable_all.
712  *
713  * If PMI hits before disable_all, the PMU will be disabled in the NMI handler.
714  * It will not be re-enabled in the NMI handler again, because enabled=0. After
715  * handling the NMI, disable_all will be called, which will not change the
716  * state either. If PMI hits after disable_all, the PMU is already disabled
717  * before entering NMI handler. The NMI handler will not change the state
718  * either.
719  *
720  * So either situation is harmless.
721  */
722 static void x86_pmu_disable(struct pmu *pmu)
723 {
724         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
725 
726         if (!x86_pmu_initialized())
727                 return;
728 
729         if (!cpuc->enabled)
730                 return;
731 
732         cpuc->n_added = 0;
733         cpuc->enabled = 0;
734         barrier();
735 
736         static_call(x86_pmu_disable_all)();
737 }
738 
739 void x86_pmu_enable_all(int added)
740 {
741         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
742         int idx;
743 
744         for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) {
745                 struct hw_perf_event *hwc = &cpuc->events[idx]->hw;
746 
747                 if (!test_bit(idx, cpuc->active_mask))
748                         continue;
749 
750                 __x86_pmu_enable_event(hwc, ARCH_PERFMON_EVENTSEL_ENABLE);
751         }
752 }
753 
754 static inline int is_x86_event(struct perf_event *event)
755 {
756         int i;
757 
758         if (!is_hybrid())
759                 return event->pmu == &pmu;
760 
761         for (i = 0; i < x86_pmu.num_hybrid_pmus; i++) {
762                 if (event->pmu == &x86_pmu.hybrid_pmu[i].pmu)
763                         return true;
764         }
765 
766         return false;
767 }
768 
769 struct pmu *x86_get_pmu(unsigned int cpu)
770 {
771         struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
772 
773         /*
774          * All CPUs of the hybrid type have been offline.
775          * The x86_get_pmu() should not be invoked.
776          */
777         if (WARN_ON_ONCE(!cpuc->pmu))
778                 return &pmu;
779 
780         return cpuc->pmu;
781 }
782 /*
783  * Event scheduler state:
784  *
785  * Assign events iterating over all events and counters, beginning
786  * with events with least weights first. Keep the current iterator
787  * state in struct sched_state.
788  */
789 struct sched_state {
790         int     weight;
791         int     event;          /* event index */
792         int     counter;        /* counter index */
793         int     unassigned;     /* number of events to be assigned left */
794         int     nr_gp;          /* number of GP counters used */
795         u64     used;
796 };
797 
798 /* Total max is X86_PMC_IDX_MAX, but we are O(n!) limited */
799 #define SCHED_STATES_MAX        2
800 
801 struct perf_sched {
802         int                     max_weight;
803         int                     max_events;
804         int                     max_gp;
805         int                     saved_states;
806         struct event_constraint **constraints;
807         struct sched_state      state;
808         struct sched_state      saved[SCHED_STATES_MAX];
809 };
810 
811 /*
812  * Initialize iterator that runs through all events and counters.
813  */
814 static void perf_sched_init(struct perf_sched *sched, struct event_constraint **constraints,
815                             int num, int wmin, int wmax, int gpmax)
816 {
817         int idx;
818 
819         memset(sched, 0, sizeof(*sched));
820         sched->max_events       = num;
821         sched->max_weight       = wmax;
822         sched->max_gp           = gpmax;
823         sched->constraints      = constraints;
824 
825         for (idx = 0; idx < num; idx++) {
826                 if (constraints[idx]->weight == wmin)
827                         break;
828         }
829 
830         sched->state.event      = idx;          /* start with min weight */
831         sched->state.weight     = wmin;
832         sched->state.unassigned = num;
833 }
834 
835 static void perf_sched_save_state(struct perf_sched *sched)
836 {
837         if (WARN_ON_ONCE(sched->saved_states >= SCHED_STATES_MAX))
838                 return;
839 
840         sched->saved[sched->saved_states] = sched->state;
841         sched->saved_states++;
842 }
843 
844 static bool perf_sched_restore_state(struct perf_sched *sched)
845 {
846         if (!sched->saved_states)
847                 return false;
848 
849         sched->saved_states--;
850         sched->state = sched->saved[sched->saved_states];
851 
852         /* this assignment didn't work out */
853         /* XXX broken vs EVENT_PAIR */
854         sched->state.used &= ~BIT_ULL(sched->state.counter);
855 
856         /* try the next one */
857         sched->state.counter++;
858 
859         return true;
860 }
861 
862 /*
863  * Select a counter for the current event to schedule. Return true on
864  * success.
865  */
866 static bool __perf_sched_find_counter(struct perf_sched *sched)
867 {
868         struct event_constraint *c;
869         int idx;
870 
871         if (!sched->state.unassigned)
872                 return false;
873 
874         if (sched->state.event >= sched->max_events)
875                 return false;
876 
877         c = sched->constraints[sched->state.event];
878         /* Prefer fixed purpose counters */
879         if (c->idxmsk64 & (~0ULL << INTEL_PMC_IDX_FIXED)) {
880                 idx = INTEL_PMC_IDX_FIXED;
881                 for_each_set_bit_from(idx, c->idxmsk, X86_PMC_IDX_MAX) {
882                         u64 mask = BIT_ULL(idx);
883 
884                         if (sched->state.used & mask)
885                                 continue;
886 
887                         sched->state.used |= mask;
888                         goto done;
889                 }
890         }
891 
892         /* Grab the first unused counter starting with idx */
893         idx = sched->state.counter;
894         for_each_set_bit_from(idx, c->idxmsk, INTEL_PMC_IDX_FIXED) {
895                 u64 mask = BIT_ULL(idx);
896 
897                 if (c->flags & PERF_X86_EVENT_PAIR)
898                         mask |= mask << 1;
899 
900                 if (sched->state.used & mask)
901                         continue;
902 
903                 if (sched->state.nr_gp++ >= sched->max_gp)
904                         return false;
905 
906                 sched->state.used |= mask;
907                 goto done;
908         }
909 
910         return false;
911 
912 done:
913         sched->state.counter = idx;
914 
915         if (c->overlap)
916                 perf_sched_save_state(sched);
917 
918         return true;
919 }
920 
921 static bool perf_sched_find_counter(struct perf_sched *sched)
922 {
923         while (!__perf_sched_find_counter(sched)) {
924                 if (!perf_sched_restore_state(sched))
925                         return false;
926         }
927 
928         return true;
929 }
930 
931 /*
932  * Go through all unassigned events and find the next one to schedule.
933  * Take events with the least weight first. Return true on success.
934  */
935 static bool perf_sched_next_event(struct perf_sched *sched)
936 {
937         struct event_constraint *c;
938 
939         if (!sched->state.unassigned || !--sched->state.unassigned)
940                 return false;
941 
942         do {
943                 /* next event */
944                 sched->state.event++;
945                 if (sched->state.event >= sched->max_events) {
946                         /* next weight */
947                         sched->state.event = 0;
948                         sched->state.weight++;
949                         if (sched->state.weight > sched->max_weight)
950                                 return false;
951                 }
952                 c = sched->constraints[sched->state.event];
953         } while (c->weight != sched->state.weight);
954 
955         sched->state.counter = 0;       /* start with first counter */
956 
957         return true;
958 }
959 
960 /*
961  * Assign a counter for each event.
962  */
963 int perf_assign_events(struct event_constraint **constraints, int n,
964                         int wmin, int wmax, int gpmax, int *assign)
965 {
966         struct perf_sched sched;
967 
968         perf_sched_init(&sched, constraints, n, wmin, wmax, gpmax);
969 
970         do {
971                 if (!perf_sched_find_counter(&sched))
972                         break;  /* failed */
973                 if (assign)
974                         assign[sched.state.event] = sched.state.counter;
975         } while (perf_sched_next_event(&sched));
976 
977         return sched.state.unassigned;
978 }
979 EXPORT_SYMBOL_GPL(perf_assign_events);
980 
981 int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
982 {
983         struct event_constraint *c;
984         struct perf_event *e;
985         int n0, i, wmin, wmax, unsched = 0;
986         struct hw_perf_event *hwc;
987         u64 used_mask = 0;
988 
989         /*
990          * Compute the number of events already present; see x86_pmu_add(),
991          * validate_group() and x86_pmu_commit_txn(). For the former two
992          * cpuc->n_events hasn't been updated yet, while for the latter
993          * cpuc->n_txn contains the number of events added in the current
994          * transaction.
995          */
996         n0 = cpuc->n_events;
997         if (cpuc->txn_flags & PERF_PMU_TXN_ADD)
998                 n0 -= cpuc->n_txn;
999 
1000         static_call_cond(x86_pmu_start_scheduling)(cpuc);
1001 
1002         for (i = 0, wmin = X86_PMC_IDX_MAX, wmax = 0; i < n; i++) {
1003                 c = cpuc->event_constraint[i];
1004 
1005                 /*
1006                  * Previously scheduled events should have a cached constraint,
1007                  * while new events should not have one.
1008                  */
1009                 WARN_ON_ONCE((c && i >= n0) || (!c && i < n0));
1010 
1011                 /*
1012                  * Request constraints for new events; or for those events that
1013                  * have a dynamic constraint -- for those the constraint can
1014                  * change due to external factors (sibling state, allow_tfa).
1015                  */
1016                 if (!c || (c->flags & PERF_X86_EVENT_DYNAMIC)) {
1017                         c = static_call(x86_pmu_get_event_constraints)(cpuc, i, cpuc->event_list[i]);
1018                         cpuc->event_constraint[i] = c;
1019                 }
1020 
1021                 wmin = min(wmin, c->weight);
1022                 wmax = max(wmax, c->weight);
1023         }
1024 
1025         /*
1026          * fastpath, try to reuse previous register
1027          */
1028         for (i = 0; i < n; i++) {
1029                 u64 mask;
1030 
1031                 hwc = &cpuc->event_list[i]->hw;
1032                 c = cpuc->event_constraint[i];
1033 
1034                 /* never assigned */
1035                 if (hwc->idx == -1)
1036                         break;
1037 
1038                 /* constraint still honored */
1039                 if (!test_bit(hwc->idx, c->idxmsk))
1040                         break;
1041 
1042                 mask = BIT_ULL(hwc->idx);
1043                 if (is_counter_pair(hwc))
1044                         mask |= mask << 1;
1045 
1046                 /* not already used */
1047                 if (used_mask & mask)
1048                         break;
1049 
1050                 used_mask |= mask;
1051 
1052                 if (assign)
1053                         assign[i] = hwc->idx;
1054         }
1055 
1056         /* slow path */
1057         if (i != n) {
1058                 int gpmax = x86_pmu_max_num_counters(cpuc->pmu);
1059 
1060                 /*
1061                  * Do not allow scheduling of more than half the available
1062                  * generic counters.
1063                  *
1064                  * This helps avoid counter starvation of sibling thread by
1065                  * ensuring at most half the counters cannot be in exclusive
1066                  * mode. There is no designated counters for the limits. Any
1067                  * N/2 counters can be used. This helps with events with
1068                  * specific counter constraints.
1069                  */
1070                 if (is_ht_workaround_enabled() && !cpuc->is_fake &&
1071                     READ_ONCE(cpuc->excl_cntrs->exclusive_present))
1072                         gpmax /= 2;
1073 
1074                 /*
1075                  * Reduce the amount of available counters to allow fitting
1076                  * the extra Merge events needed by large increment events.
1077                  */
1078                 if (x86_pmu.flags & PMU_FL_PAIR) {
1079                         gpmax -= cpuc->n_pair;
1080                         WARN_ON(gpmax <= 0);
1081                 }
1082 
1083                 unsched = perf_assign_events(cpuc->event_constraint, n, wmin,
1084                                              wmax, gpmax, assign);
1085         }
1086 
1087         /*
1088          * In case of success (unsched = 0), mark events as committed,
1089          * so we do not put_constraint() in case new events are added
1090          * and fail to be scheduled
1091          *
1092          * We invoke the lower level commit callback to lock the resource
1093          *
1094          * We do not need to do all of this in case we are called to
1095          * validate an event group (assign == NULL)
1096          */
1097         if (!unsched && assign) {
1098                 for (i = 0; i < n; i++)
1099                         static_call_cond(x86_pmu_commit_scheduling)(cpuc, i, assign[i]);
1100         } else {
1101                 for (i = n0; i < n; i++) {
1102                         e = cpuc->event_list[i];
1103 
1104                         /*
1105                          * release events that failed scheduling
1106                          */
1107                         static_call_cond(x86_pmu_put_event_constraints)(cpuc, e);
1108 
1109                         cpuc->event_constraint[i] = NULL;
1110                 }
1111         }
1112 
1113         static_call_cond(x86_pmu_stop_scheduling)(cpuc);
1114 
1115         return unsched ? -EINVAL : 0;
1116 }
1117 
1118 static int add_nr_metric_event(struct cpu_hw_events *cpuc,
1119                                struct perf_event *event)
1120 {
1121         if (is_metric_event(event)) {
1122                 if (cpuc->n_metric == INTEL_TD_METRIC_NUM)
1123                         return -EINVAL;
1124                 cpuc->n_metric++;
1125                 cpuc->n_txn_metric++;
1126         }
1127 
1128         return 0;
1129 }
1130 
1131 static void del_nr_metric_event(struct cpu_hw_events *cpuc,
1132                                 struct perf_event *event)
1133 {
1134         if (is_metric_event(event))
1135                 cpuc->n_metric--;
1136 }
1137 
1138 static int collect_event(struct cpu_hw_events *cpuc, struct perf_event *event,
1139                          int max_count, int n)
1140 {
1141         union perf_capabilities intel_cap = hybrid(cpuc->pmu, intel_cap);
1142 
1143         if (intel_cap.perf_metrics && add_nr_metric_event(cpuc, event))
1144                 return -EINVAL;
1145 
1146         if (n >= max_count + cpuc->n_metric)
1147                 return -EINVAL;
1148 
1149         cpuc->event_list[n] = event;
1150         if (is_counter_pair(&event->hw)) {
1151                 cpuc->n_pair++;
1152                 cpuc->n_txn_pair++;
1153         }
1154 
1155         return 0;
1156 }
1157 
1158 /*
1159  * dogrp: true if must collect siblings events (group)
1160  * returns total number of events and error code
1161  */
1162 static int collect_events(struct cpu_hw_events *cpuc, struct perf_event *leader, bool dogrp)
1163 {
1164         struct perf_event *event;
1165         int n, max_count;
1166 
1167         max_count = x86_pmu_num_counters(cpuc->pmu) + x86_pmu_num_counters_fixed(cpuc->pmu);
1168 
1169         /* current number of events already accepted */
1170         n = cpuc->n_events;
1171         if (!cpuc->n_events)
1172                 cpuc->pebs_output = 0;
1173 
1174         if (!cpuc->is_fake && leader->attr.precise_ip) {
1175                 /*
1176                  * For PEBS->PT, if !aux_event, the group leader (PT) went
1177                  * away, the group was broken down and this singleton event
1178                  * can't schedule any more.
1179                  */
1180                 if (is_pebs_pt(leader) && !leader->aux_event)
1181                         return -EINVAL;
1182 
1183                 /*
1184                  * pebs_output: 0: no PEBS so far, 1: PT, 2: DS
1185                  */
1186                 if (cpuc->pebs_output &&
1187                     cpuc->pebs_output != is_pebs_pt(leader) + 1)
1188                         return -EINVAL;
1189 
1190                 cpuc->pebs_output = is_pebs_pt(leader) + 1;
1191         }
1192 
1193         if (is_x86_event(leader)) {
1194                 if (collect_event(cpuc, leader, max_count, n))
1195                         return -EINVAL;
1196                 n++;
1197         }
1198 
1199         if (!dogrp)
1200                 return n;
1201 
1202         for_each_sibling_event(event, leader) {
1203                 if (!is_x86_event(event) || event->state <= PERF_EVENT_STATE_OFF)
1204                         continue;
1205 
1206                 if (collect_event(cpuc, event, max_count, n))
1207                         return -EINVAL;
1208 
1209                 n++;
1210         }
1211         return n;
1212 }
1213 
1214 static inline void x86_assign_hw_event(struct perf_event *event,
1215                                 struct cpu_hw_events *cpuc, int i)
1216 {
1217         struct hw_perf_event *hwc = &event->hw;
1218         int idx;
1219 
1220         idx = hwc->idx = cpuc->assign[i];
1221         hwc->last_cpu = smp_processor_id();
1222         hwc->last_tag = ++cpuc->tags[i];
1223 
1224         static_call_cond(x86_pmu_assign)(event, idx);
1225 
1226         switch (hwc->idx) {
1227         case INTEL_PMC_IDX_FIXED_BTS:
1228         case INTEL_PMC_IDX_FIXED_VLBR:
1229                 hwc->config_base = 0;
1230                 hwc->event_base = 0;
1231                 break;
1232 
1233         case INTEL_PMC_IDX_METRIC_BASE ... INTEL_PMC_IDX_METRIC_END:
1234                 /* All the metric events are mapped onto the fixed counter 3. */
1235                 idx = INTEL_PMC_IDX_FIXED_SLOTS;
1236                 fallthrough;
1237         case INTEL_PMC_IDX_FIXED ... INTEL_PMC_IDX_FIXED_BTS-1:
1238                 hwc->config_base = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
1239                 hwc->event_base = x86_pmu_fixed_ctr_addr(idx - INTEL_PMC_IDX_FIXED);
1240                 hwc->event_base_rdpmc = (idx - INTEL_PMC_IDX_FIXED) |
1241                                         INTEL_PMC_FIXED_RDPMC_BASE;
1242                 break;
1243 
1244         default:
1245                 hwc->config_base = x86_pmu_config_addr(hwc->idx);
1246                 hwc->event_base  = x86_pmu_event_addr(hwc->idx);
1247                 hwc->event_base_rdpmc = x86_pmu_rdpmc_index(hwc->idx);
1248                 break;
1249         }
1250 }
1251 
1252 /**
1253  * x86_perf_rdpmc_index - Return PMC counter used for event
1254  * @event: the perf_event to which the PMC counter was assigned
1255  *
1256  * The counter assigned to this performance event may change if interrupts
1257  * are enabled. This counter should thus never be used while interrupts are
1258  * enabled. Before this function is used to obtain the assigned counter the
1259  * event should be checked for validity using, for example,
1260  * perf_event_read_local(), within the same interrupt disabled section in
1261  * which this counter is planned to be used.
1262  *
1263  * Return: The index of the performance monitoring counter assigned to
1264  * @perf_event.
1265  */
1266 int x86_perf_rdpmc_index(struct perf_event *event)
1267 {
1268         lockdep_assert_irqs_disabled();
1269 
1270         return event->hw.event_base_rdpmc;
1271 }
1272 
1273 static inline int match_prev_assignment(struct hw_perf_event *hwc,
1274                                         struct cpu_hw_events *cpuc,
1275                                         int i)
1276 {
1277         return hwc->idx == cpuc->assign[i] &&
1278                 hwc->last_cpu == smp_processor_id() &&
1279                 hwc->last_tag == cpuc->tags[i];
1280 }
1281 
1282 static void x86_pmu_start(struct perf_event *event, int flags);
1283 
1284 static void x86_pmu_enable(struct pmu *pmu)
1285 {
1286         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1287         struct perf_event *event;
1288         struct hw_perf_event *hwc;
1289         int i, added = cpuc->n_added;
1290 
1291         if (!x86_pmu_initialized())
1292                 return;
1293 
1294         if (cpuc->enabled)
1295                 return;
1296 
1297         if (cpuc->n_added) {
1298                 int n_running = cpuc->n_events - cpuc->n_added;
1299                 /*
1300                  * apply assignment obtained either from
1301                  * hw_perf_group_sched_in() or x86_pmu_enable()
1302                  *
1303                  * step1: save events moving to new counters
1304                  */
1305                 for (i = 0; i < n_running; i++) {
1306                         event = cpuc->event_list[i];
1307                         hwc = &event->hw;
1308 
1309                         /*
1310                          * we can avoid reprogramming counter if:
1311                          * - assigned same counter as last time
1312                          * - running on same CPU as last time
1313                          * - no other event has used the counter since
1314                          */
1315                         if (hwc->idx == -1 ||
1316                             match_prev_assignment(hwc, cpuc, i))
1317                                 continue;
1318 
1319                         /*
1320                          * Ensure we don't accidentally enable a stopped
1321                          * counter simply because we rescheduled.
1322                          */
1323                         if (hwc->state & PERF_HES_STOPPED)
1324                                 hwc->state |= PERF_HES_ARCH;
1325 
1326                         x86_pmu_stop(event, PERF_EF_UPDATE);
1327                 }
1328 
1329                 /*
1330                  * step2: reprogram moved events into new counters
1331                  */
1332                 for (i = 0; i < cpuc->n_events; i++) {
1333                         event = cpuc->event_list[i];
1334                         hwc = &event->hw;
1335 
1336                         if (!match_prev_assignment(hwc, cpuc, i))
1337                                 x86_assign_hw_event(event, cpuc, i);
1338                         else if (i < n_running)
1339                                 continue;
1340 
1341                         if (hwc->state & PERF_HES_ARCH)
1342                                 continue;
1343 
1344                         /*
1345                          * if cpuc->enabled = 0, then no wrmsr as
1346                          * per x86_pmu_enable_event()
1347                          */
1348                         x86_pmu_start(event, PERF_EF_RELOAD);
1349                 }
1350                 cpuc->n_added = 0;
1351                 perf_events_lapic_init();
1352         }
1353 
1354         cpuc->enabled = 1;
1355         barrier();
1356 
1357         static_call(x86_pmu_enable_all)(added);
1358 }
1359 
1360 DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left);
1361 
1362 /*
1363  * Set the next IRQ period, based on the hwc->period_left value.
1364  * To be called with the event disabled in hw:
1365  */
1366 int x86_perf_event_set_period(struct perf_event *event)
1367 {
1368         struct hw_perf_event *hwc = &event->hw;
1369         s64 left = local64_read(&hwc->period_left);
1370         s64 period = hwc->sample_period;
1371         int ret = 0, idx = hwc->idx;
1372 
1373         if (unlikely(!hwc->event_base))
1374                 return 0;
1375 
1376         /*
1377          * If we are way outside a reasonable range then just skip forward:
1378          */
1379         if (unlikely(left <= -period)) {
1380                 left = period;
1381                 local64_set(&hwc->period_left, left);
1382                 hwc->last_period = period;
1383                 ret = 1;
1384         }
1385 
1386         if (unlikely(left <= 0)) {
1387                 left += period;
1388                 local64_set(&hwc->period_left, left);
1389                 hwc->last_period = period;
1390                 ret = 1;
1391         }
1392         /*
1393          * Quirk: certain CPUs dont like it if just 1 hw_event is left:
1394          */
1395         if (unlikely(left < 2))
1396                 left = 2;
1397 
1398         if (left > x86_pmu.max_period)
1399                 left = x86_pmu.max_period;
1400 
1401         static_call_cond(x86_pmu_limit_period)(event, &left);
1402 
1403         this_cpu_write(pmc_prev_left[idx], left);
1404 
1405         /*
1406          * The hw event starts counting from this event offset,
1407          * mark it to be able to extra future deltas:
1408          */
1409         local64_set(&hwc->prev_count, (u64)-left);
1410 
1411         wrmsrl(hwc->event_base, (u64)(-left) & x86_pmu.cntval_mask);
1412 
1413         /*
1414          * Sign extend the Merge event counter's upper 16 bits since
1415          * we currently declare a 48-bit counter width
1416          */
1417         if (is_counter_pair(hwc))
1418                 wrmsrl(x86_pmu_event_addr(idx + 1), 0xffff);
1419 
1420         perf_event_update_userpage(event);
1421 
1422         return ret;
1423 }
1424 
1425 void x86_pmu_enable_event(struct perf_event *event)
1426 {
1427         if (__this_cpu_read(cpu_hw_events.enabled))
1428                 __x86_pmu_enable_event(&event->hw,
1429                                        ARCH_PERFMON_EVENTSEL_ENABLE);
1430 }
1431 
1432 /*
1433  * Add a single event to the PMU.
1434  *
1435  * The event is added to the group of enabled events
1436  * but only if it can be scheduled with existing events.
1437  */
1438 static int x86_pmu_add(struct perf_event *event, int flags)
1439 {
1440         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1441         struct hw_perf_event *hwc;
1442         int assign[X86_PMC_IDX_MAX];
1443         int n, n0, ret;
1444 
1445         hwc = &event->hw;
1446 
1447         n0 = cpuc->n_events;
1448         ret = n = collect_events(cpuc, event, false);
1449         if (ret < 0)
1450                 goto out;
1451 
1452         hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
1453         if (!(flags & PERF_EF_START))
1454                 hwc->state |= PERF_HES_ARCH;
1455 
1456         /*
1457          * If group events scheduling transaction was started,
1458          * skip the schedulability test here, it will be performed
1459          * at commit time (->commit_txn) as a whole.
1460          *
1461          * If commit fails, we'll call ->del() on all events
1462          * for which ->add() was called.
1463          */
1464         if (cpuc->txn_flags & PERF_PMU_TXN_ADD)
1465                 goto done_collect;
1466 
1467         ret = static_call(x86_pmu_schedule_events)(cpuc, n, assign);
1468         if (ret)
1469                 goto out;
1470         /*
1471          * copy new assignment, now we know it is possible
1472          * will be used by hw_perf_enable()
1473          */
1474         memcpy(cpuc->assign, assign, n*sizeof(int));
1475 
1476 done_collect:
1477         /*
1478          * Commit the collect_events() state. See x86_pmu_del() and
1479          * x86_pmu_*_txn().
1480          */
1481         cpuc->n_events = n;
1482         cpuc->n_added += n - n0;
1483         cpuc->n_txn += n - n0;
1484 
1485         /*
1486          * This is before x86_pmu_enable() will call x86_pmu_start(),
1487          * so we enable LBRs before an event needs them etc..
1488          */
1489         static_call_cond(x86_pmu_add)(event);
1490 
1491         ret = 0;
1492 out:
1493         return ret;
1494 }
1495 
1496 static void x86_pmu_start(struct perf_event *event, int flags)
1497 {
1498         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1499         int idx = event->hw.idx;
1500 
1501         if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
1502                 return;
1503 
1504         if (WARN_ON_ONCE(idx == -1))
1505                 return;
1506 
1507         if (flags & PERF_EF_RELOAD) {
1508                 WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
1509                 static_call(x86_pmu_set_period)(event);
1510         }
1511 
1512         event->hw.state = 0;
1513 
1514         cpuc->events[idx] = event;
1515         __set_bit(idx, cpuc->active_mask);
1516         static_call(x86_pmu_enable)(event);
1517         perf_event_update_userpage(event);
1518 }
1519 
1520 void perf_event_print_debug(void)
1521 {
1522         u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;
1523         unsigned long *cntr_mask, *fixed_cntr_mask;
1524         struct event_constraint *pebs_constraints;
1525         struct cpu_hw_events *cpuc;
1526         u64 pebs, debugctl;
1527         int cpu, idx;
1528 
1529         guard(irqsave)();
1530 
1531         cpu = smp_processor_id();
1532         cpuc = &per_cpu(cpu_hw_events, cpu);
1533         cntr_mask = hybrid(cpuc->pmu, cntr_mask);
1534         fixed_cntr_mask = hybrid(cpuc->pmu, fixed_cntr_mask);
1535         pebs_constraints = hybrid(cpuc->pmu, pebs_constraints);
1536 
1537         if (!*(u64 *)cntr_mask)
1538                 return;
1539 
1540         if (x86_pmu.version >= 2) {
1541                 rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
1542                 rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
1543                 rdmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow);
1544                 rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed);
1545 
1546                 pr_info("\n");
1547                 pr_info("CPU#%d: ctrl:       %016llx\n", cpu, ctrl);
1548                 pr_info("CPU#%d: status:     %016llx\n", cpu, status);
1549                 pr_info("CPU#%d: overflow:   %016llx\n", cpu, overflow);
1550                 pr_info("CPU#%d: fixed:      %016llx\n", cpu, fixed);
1551                 if (pebs_constraints) {
1552                         rdmsrl(MSR_IA32_PEBS_ENABLE, pebs);
1553                         pr_info("CPU#%d: pebs:       %016llx\n", cpu, pebs);
1554                 }
1555                 if (x86_pmu.lbr_nr) {
1556                         rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
1557                         pr_info("CPU#%d: debugctl:   %016llx\n", cpu, debugctl);
1558                 }
1559         }
1560         pr_info("CPU#%d: active:     %016llx\n", cpu, *(u64 *)cpuc->active_mask);
1561 
1562         for_each_set_bit(idx, cntr_mask, X86_PMC_IDX_MAX) {
1563                 rdmsrl(x86_pmu_config_addr(idx), pmc_ctrl);
1564                 rdmsrl(x86_pmu_event_addr(idx), pmc_count);
1565 
1566                 prev_left = per_cpu(pmc_prev_left[idx], cpu);
1567 
1568                 pr_info("CPU#%d:   gen-PMC%d ctrl:  %016llx\n",
1569                         cpu, idx, pmc_ctrl);
1570                 pr_info("CPU#%d:   gen-PMC%d count: %016llx\n",
1571                         cpu, idx, pmc_count);
1572                 pr_info("CPU#%d:   gen-PMC%d left:  %016llx\n",
1573                         cpu, idx, prev_left);
1574         }
1575         for_each_set_bit(idx, fixed_cntr_mask, X86_PMC_IDX_MAX) {
1576                 if (fixed_counter_disabled(idx, cpuc->pmu))
1577                         continue;
1578                 rdmsrl(x86_pmu_fixed_ctr_addr(idx), pmc_count);
1579 
1580                 pr_info("CPU#%d: fixed-PMC%d count: %016llx\n",
1581                         cpu, idx, pmc_count);
1582         }
1583 }
1584 
1585 void x86_pmu_stop(struct perf_event *event, int flags)
1586 {
1587         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1588         struct hw_perf_event *hwc = &event->hw;
1589 
1590         if (test_bit(hwc->idx, cpuc->active_mask)) {
1591                 static_call(x86_pmu_disable)(event);
1592                 __clear_bit(hwc->idx, cpuc->active_mask);
1593                 cpuc->events[hwc->idx] = NULL;
1594                 WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
1595                 hwc->state |= PERF_HES_STOPPED;
1596         }
1597 
1598         if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
1599                 /*
1600                  * Drain the remaining delta count out of a event
1601                  * that we are disabling:
1602                  */
1603                 static_call(x86_pmu_update)(event);
1604                 hwc->state |= PERF_HES_UPTODATE;
1605         }
1606 }
1607 
1608 static void x86_pmu_del(struct perf_event *event, int flags)
1609 {
1610         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1611         union perf_capabilities intel_cap = hybrid(cpuc->pmu, intel_cap);
1612         int i;
1613 
1614         /*
1615          * If we're called during a txn, we only need to undo x86_pmu.add.
1616          * The events never got scheduled and ->cancel_txn will truncate
1617          * the event_list.
1618          *
1619          * XXX assumes any ->del() called during a TXN will only be on
1620          * an event added during that same TXN.
1621          */
1622         if (cpuc->txn_flags & PERF_PMU_TXN_ADD)
1623                 goto do_del;
1624 
1625         __set_bit(event->hw.idx, cpuc->dirty);
1626 
1627         /*
1628          * Not a TXN, therefore cleanup properly.
1629          */
1630         x86_pmu_stop(event, PERF_EF_UPDATE);
1631 
1632         for (i = 0; i < cpuc->n_events; i++) {
1633                 if (event == cpuc->event_list[i])
1634                         break;
1635         }
1636 
1637         if (WARN_ON_ONCE(i == cpuc->n_events)) /* called ->del() without ->add() ? */
1638                 return;
1639 
1640         /* If we have a newly added event; make sure to decrease n_added. */
1641         if (i >= cpuc->n_events - cpuc->n_added)
1642                 --cpuc->n_added;
1643 
1644         static_call_cond(x86_pmu_put_event_constraints)(cpuc, event);
1645 
1646         /* Delete the array entry. */
1647         while (++i < cpuc->n_events) {
1648                 cpuc->event_list[i-1] = cpuc->event_list[i];
1649                 cpuc->event_constraint[i-1] = cpuc->event_constraint[i];
1650                 cpuc->assign[i-1] = cpuc->assign[i];
1651         }
1652         cpuc->event_constraint[i-1] = NULL;
1653         --cpuc->n_events;
1654         if (intel_cap.perf_metrics)
1655                 del_nr_metric_event(cpuc, event);
1656 
1657         perf_event_update_userpage(event);
1658 
1659 do_del:
1660 
1661         /*
1662          * This is after x86_pmu_stop(); so we disable LBRs after any
1663          * event can need them etc..
1664          */
1665         static_call_cond(x86_pmu_del)(event);
1666 }
1667 
1668 int x86_pmu_handle_irq(struct pt_regs *regs)
1669 {
1670         struct perf_sample_data data;
1671         struct cpu_hw_events *cpuc;
1672         struct perf_event *event;
1673         int idx, handled = 0;
1674         u64 val;
1675 
1676         cpuc = this_cpu_ptr(&cpu_hw_events);
1677 
1678         /*
1679          * Some chipsets need to unmask the LVTPC in a particular spot
1680          * inside the nmi handler.  As a result, the unmasking was pushed
1681          * into all the nmi handlers.
1682          *
1683          * This generic handler doesn't seem to have any issues where the
1684          * unmasking occurs so it was left at the top.
1685          */
1686         apic_write(APIC_LVTPC, APIC_DM_NMI);
1687 
1688         for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) {
1689                 if (!test_bit(idx, cpuc->active_mask))
1690                         continue;
1691 
1692                 event = cpuc->events[idx];
1693 
1694                 val = static_call(x86_pmu_update)(event);
1695                 if (val & (1ULL << (x86_pmu.cntval_bits - 1)))
1696                         continue;
1697 
1698                 /*
1699                  * event overflow
1700                  */
1701                 handled++;
1702 
1703                 if (!static_call(x86_pmu_set_period)(event))
1704                         continue;
1705 
1706                 perf_sample_data_init(&data, 0, event->hw.last_period);
1707 
1708                 if (has_branch_stack(event))
1709                         perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL);
1710 
1711                 if (perf_event_overflow(event, &data, regs))
1712                         x86_pmu_stop(event, 0);
1713         }
1714 
1715         if (handled)
1716                 inc_irq_stat(apic_perf_irqs);
1717 
1718         return handled;
1719 }
1720 
1721 void perf_events_lapic_init(void)
1722 {
1723         if (!x86_pmu.apic || !x86_pmu_initialized())
1724                 return;
1725 
1726         /*
1727          * Always use NMI for PMU
1728          */
1729         apic_write(APIC_LVTPC, APIC_DM_NMI);
1730 }
1731 
1732 static int
1733 perf_event_nmi_handler(unsigned int cmd, struct pt_regs *regs)
1734 {
1735         u64 start_clock;
1736         u64 finish_clock;
1737         int ret;
1738 
1739         /*
1740          * All PMUs/events that share this PMI handler should make sure to
1741          * increment active_events for their events.
1742          */
1743         if (!atomic_read(&active_events))
1744                 return NMI_DONE;
1745 
1746         start_clock = sched_clock();
1747         ret = static_call(x86_pmu_handle_irq)(regs);
1748         finish_clock = sched_clock();
1749 
1750         perf_sample_event_took(finish_clock - start_clock);
1751 
1752         return ret;
1753 }
1754 NOKPROBE_SYMBOL(perf_event_nmi_handler);
1755 
1756 struct event_constraint emptyconstraint;
1757 struct event_constraint unconstrained;
1758 
1759 static int x86_pmu_prepare_cpu(unsigned int cpu)
1760 {
1761         struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
1762         int i;
1763 
1764         for (i = 0 ; i < X86_PERF_KFREE_MAX; i++)
1765                 cpuc->kfree_on_online[i] = NULL;
1766         if (x86_pmu.cpu_prepare)
1767                 return x86_pmu.cpu_prepare(cpu);
1768         return 0;
1769 }
1770 
1771 static int x86_pmu_dead_cpu(unsigned int cpu)
1772 {
1773         if (x86_pmu.cpu_dead)
1774                 x86_pmu.cpu_dead(cpu);
1775         return 0;
1776 }
1777 
1778 static int x86_pmu_online_cpu(unsigned int cpu)
1779 {
1780         struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
1781         int i;
1782 
1783         for (i = 0 ; i < X86_PERF_KFREE_MAX; i++) {
1784                 kfree(cpuc->kfree_on_online[i]);
1785                 cpuc->kfree_on_online[i] = NULL;
1786         }
1787         return 0;
1788 }
1789 
1790 static int x86_pmu_starting_cpu(unsigned int cpu)
1791 {
1792         if (x86_pmu.cpu_starting)
1793                 x86_pmu.cpu_starting(cpu);
1794         return 0;
1795 }
1796 
1797 static int x86_pmu_dying_cpu(unsigned int cpu)
1798 {
1799         if (x86_pmu.cpu_dying)
1800                 x86_pmu.cpu_dying(cpu);
1801         return 0;
1802 }
1803 
1804 static void __init pmu_check_apic(void)
1805 {
1806         if (boot_cpu_has(X86_FEATURE_APIC))
1807                 return;
1808 
1809         x86_pmu.apic = 0;
1810         pr_info("no APIC, boot with the \"lapic\" boot parameter to force-enable it.\n");
1811         pr_info("no hardware sampling interrupt available.\n");
1812 
1813         /*
1814          * If we have a PMU initialized but no APIC
1815          * interrupts, we cannot sample hardware
1816          * events (user-space has to fall back and
1817          * sample via a hrtimer based software event):
1818          */
1819         pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
1820 
1821 }
1822 
1823 static struct attribute_group x86_pmu_format_group __ro_after_init = {
1824         .name = "format",
1825         .attrs = NULL,
1826 };
1827 
1828 ssize_t events_sysfs_show(struct device *dev, struct device_attribute *attr, char *page)
1829 {
1830         struct perf_pmu_events_attr *pmu_attr =
1831                 container_of(attr, struct perf_pmu_events_attr, attr);
1832         u64 config = 0;
1833 
1834         if (pmu_attr->id < x86_pmu.max_events)
1835                 config = x86_pmu.event_map(pmu_attr->id);
1836 
1837         /* string trumps id */
1838         if (pmu_attr->event_str)
1839                 return sprintf(page, "%s\n", pmu_attr->event_str);
1840 
1841         return x86_pmu.events_sysfs_show(page, config);
1842 }
1843 EXPORT_SYMBOL_GPL(events_sysfs_show);
1844 
1845 ssize_t events_ht_sysfs_show(struct device *dev, struct device_attribute *attr,
1846                           char *page)
1847 {
1848         struct perf_pmu_events_ht_attr *pmu_attr =
1849                 container_of(attr, struct perf_pmu_events_ht_attr, attr);
1850 
1851         /*
1852          * Report conditional events depending on Hyper-Threading.
1853          *
1854          * This is overly conservative as usually the HT special
1855          * handling is not needed if the other CPU thread is idle.
1856          *
1857          * Note this does not (and cannot) handle the case when thread
1858          * siblings are invisible, for example with virtualization
1859          * if they are owned by some other guest.  The user tool
1860          * has to re-read when a thread sibling gets onlined later.
1861          */
1862         return sprintf(page, "%s",
1863                         topology_max_smt_threads() > 1 ?
1864                         pmu_attr->event_str_ht :
1865                         pmu_attr->event_str_noht);
1866 }
1867 
1868 ssize_t events_hybrid_sysfs_show(struct device *dev,
1869                                  struct device_attribute *attr,
1870                                  char *page)
1871 {
1872         struct perf_pmu_events_hybrid_attr *pmu_attr =
1873                 container_of(attr, struct perf_pmu_events_hybrid_attr, attr);
1874         struct x86_hybrid_pmu *pmu;
1875         const char *str, *next_str;
1876         int i;
1877 
1878         if (hweight64(pmu_attr->pmu_type) == 1)
1879                 return sprintf(page, "%s", pmu_attr->event_str);
1880 
1881         /*
1882          * Hybrid PMUs may support the same event name, but with different
1883          * event encoding, e.g., the mem-loads event on an Atom PMU has
1884          * different event encoding from a Core PMU.
1885          *
1886          * The event_str includes all event encodings. Each event encoding
1887          * is divided by ";". The order of the event encodings must follow
1888          * the order of the hybrid PMU index.
1889          */
1890         pmu = container_of(dev_get_drvdata(dev), struct x86_hybrid_pmu, pmu);
1891 
1892         str = pmu_attr->event_str;
1893         for (i = 0; i < x86_pmu.num_hybrid_pmus; i++) {
1894                 if (!(x86_pmu.hybrid_pmu[i].pmu_type & pmu_attr->pmu_type))
1895                         continue;
1896                 if (x86_pmu.hybrid_pmu[i].pmu_type & pmu->pmu_type) {
1897                         next_str = strchr(str, ';');
1898                         if (next_str)
1899                                 return snprintf(page, next_str - str + 1, "%s", str);
1900                         else
1901                                 return sprintf(page, "%s", str);
1902                 }
1903                 str = strchr(str, ';');
1904                 str++;
1905         }
1906 
1907         return 0;
1908 }
1909 EXPORT_SYMBOL_GPL(events_hybrid_sysfs_show);
1910 
1911 EVENT_ATTR(cpu-cycles,                  CPU_CYCLES              );
1912 EVENT_ATTR(instructions,                INSTRUCTIONS            );
1913 EVENT_ATTR(cache-references,            CACHE_REFERENCES        );
1914 EVENT_ATTR(cache-misses,                CACHE_MISSES            );
1915 EVENT_ATTR(branch-instructions,         BRANCH_INSTRUCTIONS     );
1916 EVENT_ATTR(branch-misses,               BRANCH_MISSES           );
1917 EVENT_ATTR(bus-cycles,                  BUS_CYCLES              );
1918 EVENT_ATTR(stalled-cycles-frontend,     STALLED_CYCLES_FRONTEND );
1919 EVENT_ATTR(stalled-cycles-backend,      STALLED_CYCLES_BACKEND  );
1920 EVENT_ATTR(ref-cycles,                  REF_CPU_CYCLES          );
1921 
1922 static struct attribute *empty_attrs;
1923 
1924 static struct attribute *events_attr[] = {
1925         EVENT_PTR(CPU_CYCLES),
1926         EVENT_PTR(INSTRUCTIONS),
1927         EVENT_PTR(CACHE_REFERENCES),
1928         EVENT_PTR(CACHE_MISSES),
1929         EVENT_PTR(BRANCH_INSTRUCTIONS),
1930         EVENT_PTR(BRANCH_MISSES),
1931         EVENT_PTR(BUS_CYCLES),
1932         EVENT_PTR(STALLED_CYCLES_FRONTEND),
1933         EVENT_PTR(STALLED_CYCLES_BACKEND),
1934         EVENT_PTR(REF_CPU_CYCLES),
1935         NULL,
1936 };
1937 
1938 /*
1939  * Remove all undefined events (x86_pmu.event_map(id) == 0)
1940  * out of events_attr attributes.
1941  */
1942 static umode_t
1943 is_visible(struct kobject *kobj, struct attribute *attr, int idx)
1944 {
1945         struct perf_pmu_events_attr *pmu_attr;
1946 
1947         if (idx >= x86_pmu.max_events)
1948                 return 0;
1949 
1950         pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr.attr);
1951         /* str trumps id */
1952         return pmu_attr->event_str || x86_pmu.event_map(idx) ? attr->mode : 0;
1953 }
1954 
1955 static struct attribute_group x86_pmu_events_group __ro_after_init = {
1956         .name = "events",
1957         .attrs = events_attr,
1958         .is_visible = is_visible,
1959 };
1960 
1961 ssize_t x86_event_sysfs_show(char *page, u64 config, u64 event)
1962 {
1963         u64 umask  = (config & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;
1964         u64 cmask  = (config & ARCH_PERFMON_EVENTSEL_CMASK) >> 24;
1965         bool edge  = (config & ARCH_PERFMON_EVENTSEL_EDGE);
1966         bool pc    = (config & ARCH_PERFMON_EVENTSEL_PIN_CONTROL);
1967         bool any   = (config & ARCH_PERFMON_EVENTSEL_ANY);
1968         bool inv   = (config & ARCH_PERFMON_EVENTSEL_INV);
1969         ssize_t ret;
1970 
1971         /*
1972         * We have whole page size to spend and just little data
1973         * to write, so we can safely use sprintf.
1974         */
1975         ret = sprintf(page, "event=0x%02llx", event);
1976 
1977         if (umask)
1978                 ret += sprintf(page + ret, ",umask=0x%02llx", umask);
1979 
1980         if (edge)
1981                 ret += sprintf(page + ret, ",edge");
1982 
1983         if (pc)
1984                 ret += sprintf(page + ret, ",pc");
1985 
1986         if (any)
1987                 ret += sprintf(page + ret, ",any");
1988 
1989         if (inv)
1990                 ret += sprintf(page + ret, ",inv");
1991 
1992         if (cmask)
1993                 ret += sprintf(page + ret, ",cmask=0x%02llx", cmask);
1994 
1995         ret += sprintf(page + ret, "\n");
1996 
1997         return ret;
1998 }
1999 
2000 static struct attribute_group x86_pmu_attr_group;
2001 static struct attribute_group x86_pmu_caps_group;
2002 
2003 static void x86_pmu_static_call_update(void)
2004 {
2005         static_call_update(x86_pmu_handle_irq, x86_pmu.handle_irq);
2006         static_call_update(x86_pmu_disable_all, x86_pmu.disable_all);
2007         static_call_update(x86_pmu_enable_all, x86_pmu.enable_all);
2008         static_call_update(x86_pmu_enable, x86_pmu.enable);
2009         static_call_update(x86_pmu_disable, x86_pmu.disable);
2010 
2011         static_call_update(x86_pmu_assign, x86_pmu.assign);
2012 
2013         static_call_update(x86_pmu_add, x86_pmu.add);
2014         static_call_update(x86_pmu_del, x86_pmu.del);
2015         static_call_update(x86_pmu_read, x86_pmu.read);
2016 
2017         static_call_update(x86_pmu_set_period, x86_pmu.set_period);
2018         static_call_update(x86_pmu_update, x86_pmu.update);
2019         static_call_update(x86_pmu_limit_period, x86_pmu.limit_period);
2020 
2021         static_call_update(x86_pmu_schedule_events, x86_pmu.schedule_events);
2022         static_call_update(x86_pmu_get_event_constraints, x86_pmu.get_event_constraints);
2023         static_call_update(x86_pmu_put_event_constraints, x86_pmu.put_event_constraints);
2024 
2025         static_call_update(x86_pmu_start_scheduling, x86_pmu.start_scheduling);
2026         static_call_update(x86_pmu_commit_scheduling, x86_pmu.commit_scheduling);
2027         static_call_update(x86_pmu_stop_scheduling, x86_pmu.stop_scheduling);
2028 
2029         static_call_update(x86_pmu_sched_task, x86_pmu.sched_task);
2030         static_call_update(x86_pmu_swap_task_ctx, x86_pmu.swap_task_ctx);
2031 
2032         static_call_update(x86_pmu_drain_pebs, x86_pmu.drain_pebs);
2033         static_call_update(x86_pmu_pebs_aliases, x86_pmu.pebs_aliases);
2034 
2035         static_call_update(x86_pmu_guest_get_msrs, x86_pmu.guest_get_msrs);
2036         static_call_update(x86_pmu_filter, x86_pmu.filter);
2037 }
2038 
2039 static void _x86_pmu_read(struct perf_event *event)
2040 {
2041         static_call(x86_pmu_update)(event);
2042 }
2043 
2044 void x86_pmu_show_pmu_cap(struct pmu *pmu)
2045 {
2046         pr_info("... version:                %d\n",     x86_pmu.version);
2047         pr_info("... bit width:              %d\n",     x86_pmu.cntval_bits);
2048         pr_info("... generic registers:      %d\n",     x86_pmu_num_counters(pmu));
2049         pr_info("... value mask:             %016Lx\n", x86_pmu.cntval_mask);
2050         pr_info("... max period:             %016Lx\n", x86_pmu.max_period);
2051         pr_info("... fixed-purpose events:   %d\n",     x86_pmu_num_counters_fixed(pmu));
2052         pr_info("... event mask:             %016Lx\n", hybrid(pmu, intel_ctrl));
2053 }
2054 
2055 static int __init init_hw_perf_events(void)
2056 {
2057         struct x86_pmu_quirk *quirk;
2058         int err;
2059 
2060         pr_info("Performance Events: ");
2061 
2062         switch (boot_cpu_data.x86_vendor) {
2063         case X86_VENDOR_INTEL:
2064                 err = intel_pmu_init();
2065                 break;
2066         case X86_VENDOR_AMD:
2067                 err = amd_pmu_init();
2068                 break;
2069         case X86_VENDOR_HYGON:
2070                 err = amd_pmu_init();
2071                 x86_pmu.name = "HYGON";
2072                 break;
2073         case X86_VENDOR_ZHAOXIN:
2074         case X86_VENDOR_CENTAUR:
2075                 err = zhaoxin_pmu_init();
2076                 break;
2077         default:
2078                 err = -ENOTSUPP;
2079         }
2080         if (err != 0) {
2081                 pr_cont("no PMU driver, software events only.\n");
2082                 err = 0;
2083                 goto out_bad_pmu;
2084         }
2085 
2086         pmu_check_apic();
2087 
2088         /* sanity check that the hardware exists or is emulated */
2089         if (!check_hw_exists(&pmu, x86_pmu.cntr_mask, x86_pmu.fixed_cntr_mask))
2090                 goto out_bad_pmu;
2091 
2092         pr_cont("%s PMU driver.\n", x86_pmu.name);
2093 
2094         x86_pmu.attr_rdpmc = 1; /* enable userspace RDPMC usage by default */
2095 
2096         for (quirk = x86_pmu.quirks; quirk; quirk = quirk->next)
2097                 quirk->func();
2098 
2099         if (!x86_pmu.intel_ctrl)
2100                 x86_pmu.intel_ctrl = x86_pmu.cntr_mask64;
2101 
2102         if (!x86_pmu.config_mask)
2103                 x86_pmu.config_mask = X86_RAW_EVENT_MASK;
2104 
2105         perf_events_lapic_init();
2106         register_nmi_handler(NMI_LOCAL, perf_event_nmi_handler, 0, "PMI");
2107 
2108         unconstrained = (struct event_constraint)
2109                 __EVENT_CONSTRAINT(0, x86_pmu.cntr_mask64,
2110                                    0, x86_pmu_num_counters(NULL), 0, 0);
2111 
2112         x86_pmu_format_group.attrs = x86_pmu.format_attrs;
2113 
2114         if (!x86_pmu.events_sysfs_show)
2115                 x86_pmu_events_group.attrs = &empty_attrs;
2116 
2117         pmu.attr_update = x86_pmu.attr_update;
2118 
2119         if (!is_hybrid())
2120                 x86_pmu_show_pmu_cap(NULL);
2121 
2122         if (!x86_pmu.read)
2123                 x86_pmu.read = _x86_pmu_read;
2124 
2125         if (!x86_pmu.guest_get_msrs)
2126                 x86_pmu.guest_get_msrs = (void *)&__static_call_return0;
2127 
2128         if (!x86_pmu.set_period)
2129                 x86_pmu.set_period = x86_perf_event_set_period;
2130 
2131         if (!x86_pmu.update)
2132                 x86_pmu.update = x86_perf_event_update;
2133 
2134         x86_pmu_static_call_update();
2135 
2136         /*
2137          * Install callbacks. Core will call them for each online
2138          * cpu.
2139          */
2140         err = cpuhp_setup_state(CPUHP_PERF_X86_PREPARE, "perf/x86:prepare",
2141                                 x86_pmu_prepare_cpu, x86_pmu_dead_cpu);
2142         if (err)
2143                 return err;
2144 
2145         err = cpuhp_setup_state(CPUHP_AP_PERF_X86_STARTING,
2146                                 "perf/x86:starting", x86_pmu_starting_cpu,
2147                                 x86_pmu_dying_cpu);
2148         if (err)
2149                 goto out;
2150 
2151         err = cpuhp_setup_state(CPUHP_AP_PERF_X86_ONLINE, "perf/x86:online",
2152                                 x86_pmu_online_cpu, NULL);
2153         if (err)
2154                 goto out1;
2155 
2156         if (!is_hybrid()) {
2157                 err = perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
2158                 if (err)
2159                         goto out2;
2160         } else {
2161                 struct x86_hybrid_pmu *hybrid_pmu;
2162                 int i, j;
2163 
2164                 for (i = 0; i < x86_pmu.num_hybrid_pmus; i++) {
2165                         hybrid_pmu = &x86_pmu.hybrid_pmu[i];
2166 
2167                         hybrid_pmu->pmu = pmu;
2168                         hybrid_pmu->pmu.type = -1;
2169                         hybrid_pmu->pmu.attr_update = x86_pmu.attr_update;
2170                         hybrid_pmu->pmu.capabilities |= PERF_PMU_CAP_EXTENDED_HW_TYPE;
2171 
2172                         err = perf_pmu_register(&hybrid_pmu->pmu, hybrid_pmu->name,
2173                                                 (hybrid_pmu->pmu_type == hybrid_big) ? PERF_TYPE_RAW : -1);
2174                         if (err)
2175                                 break;
2176                 }
2177 
2178                 if (i < x86_pmu.num_hybrid_pmus) {
2179                         for (j = 0; j < i; j++)
2180                                 perf_pmu_unregister(&x86_pmu.hybrid_pmu[j].pmu);
2181                         pr_warn("Failed to register hybrid PMUs\n");
2182                         kfree(x86_pmu.hybrid_pmu);
2183                         x86_pmu.hybrid_pmu = NULL;
2184                         x86_pmu.num_hybrid_pmus = 0;
2185                         goto out2;
2186                 }
2187         }
2188 
2189         return 0;
2190 
2191 out2:
2192         cpuhp_remove_state(CPUHP_AP_PERF_X86_ONLINE);
2193 out1:
2194         cpuhp_remove_state(CPUHP_AP_PERF_X86_STARTING);
2195 out:
2196         cpuhp_remove_state(CPUHP_PERF_X86_PREPARE);
2197 out_bad_pmu:
2198         memset(&x86_pmu, 0, sizeof(x86_pmu));
2199         return err;
2200 }
2201 early_initcall(init_hw_perf_events);
2202 
2203 static void x86_pmu_read(struct perf_event *event)
2204 {
2205         static_call(x86_pmu_read)(event);
2206 }
2207 
2208 /*
2209  * Start group events scheduling transaction
2210  * Set the flag to make pmu::enable() not perform the
2211  * schedulability test, it will be performed at commit time
2212  *
2213  * We only support PERF_PMU_TXN_ADD transactions. Save the
2214  * transaction flags but otherwise ignore non-PERF_PMU_TXN_ADD
2215  * transactions.
2216  */
2217 static void x86_pmu_start_txn(struct pmu *pmu, unsigned int txn_flags)
2218 {
2219         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
2220 
2221         WARN_ON_ONCE(cpuc->txn_flags);          /* txn already in flight */
2222 
2223         cpuc->txn_flags = txn_flags;
2224         if (txn_flags & ~PERF_PMU_TXN_ADD)
2225                 return;
2226 
2227         perf_pmu_disable(pmu);
2228         __this_cpu_write(cpu_hw_events.n_txn, 0);
2229         __this_cpu_write(cpu_hw_events.n_txn_pair, 0);
2230         __this_cpu_write(cpu_hw_events.n_txn_metric, 0);
2231 }
2232 
2233 /*
2234  * Stop group events scheduling transaction
2235  * Clear the flag and pmu::enable() will perform the
2236  * schedulability test.
2237  */
2238 static void x86_pmu_cancel_txn(struct pmu *pmu)
2239 {
2240         unsigned int txn_flags;
2241         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
2242 
2243         WARN_ON_ONCE(!cpuc->txn_flags); /* no txn in flight */
2244 
2245         txn_flags = cpuc->txn_flags;
2246         cpuc->txn_flags = 0;
2247         if (txn_flags & ~PERF_PMU_TXN_ADD)
2248                 return;
2249 
2250         /*
2251          * Truncate collected array by the number of events added in this
2252          * transaction. See x86_pmu_add() and x86_pmu_*_txn().
2253          */
2254         __this_cpu_sub(cpu_hw_events.n_added, __this_cpu_read(cpu_hw_events.n_txn));
2255         __this_cpu_sub(cpu_hw_events.n_events, __this_cpu_read(cpu_hw_events.n_txn));
2256         __this_cpu_sub(cpu_hw_events.n_pair, __this_cpu_read(cpu_hw_events.n_txn_pair));
2257         __this_cpu_sub(cpu_hw_events.n_metric, __this_cpu_read(cpu_hw_events.n_txn_metric));
2258         perf_pmu_enable(pmu);
2259 }
2260 
2261 /*
2262  * Commit group events scheduling transaction
2263  * Perform the group schedulability test as a whole
2264  * Return 0 if success
2265  *
2266  * Does not cancel the transaction on failure; expects the caller to do this.
2267  */
2268 static int x86_pmu_commit_txn(struct pmu *pmu)
2269 {
2270         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
2271         int assign[X86_PMC_IDX_MAX];
2272         int n, ret;
2273 
2274         WARN_ON_ONCE(!cpuc->txn_flags); /* no txn in flight */
2275 
2276         if (cpuc->txn_flags & ~PERF_PMU_TXN_ADD) {
2277                 cpuc->txn_flags = 0;
2278                 return 0;
2279         }
2280 
2281         n = cpuc->n_events;
2282 
2283         if (!x86_pmu_initialized())
2284                 return -EAGAIN;
2285 
2286         ret = static_call(x86_pmu_schedule_events)(cpuc, n, assign);
2287         if (ret)
2288                 return ret;
2289 
2290         /*
2291          * copy new assignment, now we know it is possible
2292          * will be used by hw_perf_enable()
2293          */
2294         memcpy(cpuc->assign, assign, n*sizeof(int));
2295 
2296         cpuc->txn_flags = 0;
2297         perf_pmu_enable(pmu);
2298         return 0;
2299 }
2300 /*
2301  * a fake_cpuc is used to validate event groups. Due to
2302  * the extra reg logic, we need to also allocate a fake
2303  * per_core and per_cpu structure. Otherwise, group events
2304  * using extra reg may conflict without the kernel being
2305  * able to catch this when the last event gets added to
2306  * the group.
2307  */
2308 static void free_fake_cpuc(struct cpu_hw_events *cpuc)
2309 {
2310         intel_cpuc_finish(cpuc);
2311         kfree(cpuc);
2312 }
2313 
2314 static struct cpu_hw_events *allocate_fake_cpuc(struct pmu *event_pmu)
2315 {
2316         struct cpu_hw_events *cpuc;
2317         int cpu;
2318 
2319         cpuc = kzalloc(sizeof(*cpuc), GFP_KERNEL);
2320         if (!cpuc)
2321                 return ERR_PTR(-ENOMEM);
2322         cpuc->is_fake = 1;
2323 
2324         if (is_hybrid()) {
2325                 struct x86_hybrid_pmu *h_pmu;
2326 
2327                 h_pmu = hybrid_pmu(event_pmu);
2328                 if (cpumask_empty(&h_pmu->supported_cpus))
2329                         goto error;
2330                 cpu = cpumask_first(&h_pmu->supported_cpus);
2331         } else
2332                 cpu = raw_smp_processor_id();
2333         cpuc->pmu = event_pmu;
2334 
2335         if (intel_cpuc_prepare(cpuc, cpu))
2336                 goto error;
2337 
2338         return cpuc;
2339 error:
2340         free_fake_cpuc(cpuc);
2341         return ERR_PTR(-ENOMEM);
2342 }
2343 
2344 /*
2345  * validate that we can schedule this event
2346  */
2347 static int validate_event(struct perf_event *event)
2348 {
2349         struct cpu_hw_events *fake_cpuc;
2350         struct event_constraint *c;
2351         int ret = 0;
2352 
2353         fake_cpuc = allocate_fake_cpuc(event->pmu);
2354         if (IS_ERR(fake_cpuc))
2355                 return PTR_ERR(fake_cpuc);
2356 
2357         c = x86_pmu.get_event_constraints(fake_cpuc, 0, event);
2358 
2359         if (!c || !c->weight)
2360                 ret = -EINVAL;
2361 
2362         if (x86_pmu.put_event_constraints)
2363                 x86_pmu.put_event_constraints(fake_cpuc, event);
2364 
2365         free_fake_cpuc(fake_cpuc);
2366 
2367         return ret;
2368 }
2369 
2370 /*
2371  * validate a single event group
2372  *
2373  * validation include:
2374  *      - check events are compatible which each other
2375  *      - events do not compete for the same counter
2376  *      - number of events <= number of counters
2377  *
2378  * validation ensures the group can be loaded onto the
2379  * PMU if it was the only group available.
2380  */
2381 static int validate_group(struct perf_event *event)
2382 {
2383         struct perf_event *leader = event->group_leader;
2384         struct cpu_hw_events *fake_cpuc;
2385         int ret = -EINVAL, n;
2386 
2387         /*
2388          * Reject events from different hybrid PMUs.
2389          */
2390         if (is_hybrid()) {
2391                 struct perf_event *sibling;
2392                 struct pmu *pmu = NULL;
2393 
2394                 if (is_x86_event(leader))
2395                         pmu = leader->pmu;
2396 
2397                 for_each_sibling_event(sibling, leader) {
2398                         if (!is_x86_event(sibling))
2399                                 continue;
2400                         if (!pmu)
2401                                 pmu = sibling->pmu;
2402                         else if (pmu != sibling->pmu)
2403                                 return ret;
2404                 }
2405         }
2406 
2407         fake_cpuc = allocate_fake_cpuc(event->pmu);
2408         if (IS_ERR(fake_cpuc))
2409                 return PTR_ERR(fake_cpuc);
2410         /*
2411          * the event is not yet connected with its
2412          * siblings therefore we must first collect
2413          * existing siblings, then add the new event
2414          * before we can simulate the scheduling
2415          */
2416         n = collect_events(fake_cpuc, leader, true);
2417         if (n < 0)
2418                 goto out;
2419 
2420         fake_cpuc->n_events = n;
2421         n = collect_events(fake_cpuc, event, false);
2422         if (n < 0)
2423                 goto out;
2424 
2425         fake_cpuc->n_events = 0;
2426         ret = x86_pmu.schedule_events(fake_cpuc, n, NULL);
2427 
2428 out:
2429         free_fake_cpuc(fake_cpuc);
2430         return ret;
2431 }
2432 
2433 static int x86_pmu_event_init(struct perf_event *event)
2434 {
2435         struct x86_hybrid_pmu *pmu = NULL;
2436         int err;
2437 
2438         if ((event->attr.type != event->pmu->type) &&
2439             (event->attr.type != PERF_TYPE_HARDWARE) &&
2440             (event->attr.type != PERF_TYPE_HW_CACHE))
2441                 return -ENOENT;
2442 
2443         if (is_hybrid() && (event->cpu != -1)) {
2444                 pmu = hybrid_pmu(event->pmu);
2445                 if (!cpumask_test_cpu(event->cpu, &pmu->supported_cpus))
2446                         return -ENOENT;
2447         }
2448 
2449         err = __x86_pmu_event_init(event);
2450         if (!err) {
2451                 if (event->group_leader != event)
2452                         err = validate_group(event);
2453                 else
2454                         err = validate_event(event);
2455         }
2456         if (err) {
2457                 if (event->destroy)
2458                         event->destroy(event);
2459                 event->destroy = NULL;
2460         }
2461 
2462         if (READ_ONCE(x86_pmu.attr_rdpmc) &&
2463             !(event->hw.flags & PERF_X86_EVENT_LARGE_PEBS))
2464                 event->hw.flags |= PERF_EVENT_FLAG_USER_READ_CNT;
2465 
2466         return err;
2467 }
2468 
2469 void perf_clear_dirty_counters(void)
2470 {
2471         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
2472         int i;
2473 
2474          /* Don't need to clear the assigned counter. */
2475         for (i = 0; i < cpuc->n_events; i++)
2476                 __clear_bit(cpuc->assign[i], cpuc->dirty);
2477 
2478         if (bitmap_empty(cpuc->dirty, X86_PMC_IDX_MAX))
2479                 return;
2480 
2481         for_each_set_bit(i, cpuc->dirty, X86_PMC_IDX_MAX) {
2482                 if (i >= INTEL_PMC_IDX_FIXED) {
2483                         /* Metrics and fake events don't have corresponding HW counters. */
2484                         if (!test_bit(i - INTEL_PMC_IDX_FIXED, hybrid(cpuc->pmu, fixed_cntr_mask)))
2485                                 continue;
2486 
2487                         wrmsrl(x86_pmu_fixed_ctr_addr(i - INTEL_PMC_IDX_FIXED), 0);
2488                 } else {
2489                         wrmsrl(x86_pmu_event_addr(i), 0);
2490                 }
2491         }
2492 
2493         bitmap_zero(cpuc->dirty, X86_PMC_IDX_MAX);
2494 }
2495 
2496 static void x86_pmu_event_mapped(struct perf_event *event, struct mm_struct *mm)
2497 {
2498         if (!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT))
2499                 return;
2500 
2501         /*
2502          * This function relies on not being called concurrently in two
2503          * tasks in the same mm.  Otherwise one task could observe
2504          * perf_rdpmc_allowed > 1 and return all the way back to
2505          * userspace with CR4.PCE clear while another task is still
2506          * doing on_each_cpu_mask() to propagate CR4.PCE.
2507          *
2508          * For now, this can't happen because all callers hold mmap_lock
2509          * for write.  If this changes, we'll need a different solution.
2510          */
2511         mmap_assert_write_locked(mm);
2512 
2513         if (atomic_inc_return(&mm->context.perf_rdpmc_allowed) == 1)
2514                 on_each_cpu_mask(mm_cpumask(mm), cr4_update_pce, NULL, 1);
2515 }
2516 
2517 static void x86_pmu_event_unmapped(struct perf_event *event, struct mm_struct *mm)
2518 {
2519         if (!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT))
2520                 return;
2521 
2522         if (atomic_dec_and_test(&mm->context.perf_rdpmc_allowed))
2523                 on_each_cpu_mask(mm_cpumask(mm), cr4_update_pce, NULL, 1);
2524 }
2525 
2526 static int x86_pmu_event_idx(struct perf_event *event)
2527 {
2528         struct hw_perf_event *hwc = &event->hw;
2529 
2530         if (!(hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT))
2531                 return 0;
2532 
2533         if (is_metric_idx(hwc->idx))
2534                 return INTEL_PMC_FIXED_RDPMC_METRICS + 1;
2535         else
2536                 return hwc->event_base_rdpmc + 1;
2537 }
2538 
2539 static ssize_t get_attr_rdpmc(struct device *cdev,
2540                               struct device_attribute *attr,
2541                               char *buf)
2542 {
2543         return snprintf(buf, 40, "%d\n", x86_pmu.attr_rdpmc);
2544 }
2545 
2546 static ssize_t set_attr_rdpmc(struct device *cdev,
2547                               struct device_attribute *attr,
2548                               const char *buf, size_t count)
2549 {
2550         static DEFINE_MUTEX(rdpmc_mutex);
2551         unsigned long val;
2552         ssize_t ret;
2553 
2554         ret = kstrtoul(buf, 0, &val);
2555         if (ret)
2556                 return ret;
2557 
2558         if (val > 2)
2559                 return -EINVAL;
2560 
2561         if (x86_pmu.attr_rdpmc_broken)
2562                 return -ENOTSUPP;
2563 
2564         guard(mutex)(&rdpmc_mutex);
2565 
2566         if (val != x86_pmu.attr_rdpmc) {
2567                 /*
2568                  * Changing into or out of never available or always available,
2569                  * aka perf-event-bypassing mode. This path is extremely slow,
2570                  * but only root can trigger it, so it's okay.
2571                  */
2572                 if (val == 0)
2573                         static_branch_inc(&rdpmc_never_available_key);
2574                 else if (x86_pmu.attr_rdpmc == 0)
2575                         static_branch_dec(&rdpmc_never_available_key);
2576 
2577                 if (val == 2)
2578                         static_branch_inc(&rdpmc_always_available_key);
2579                 else if (x86_pmu.attr_rdpmc == 2)
2580                         static_branch_dec(&rdpmc_always_available_key);
2581 
2582                 on_each_cpu(cr4_update_pce, NULL, 1);
2583                 x86_pmu.attr_rdpmc = val;
2584         }
2585 
2586         return count;
2587 }
2588 
2589 static DEVICE_ATTR(rdpmc, S_IRUSR | S_IWUSR, get_attr_rdpmc, set_attr_rdpmc);
2590 
2591 static struct attribute *x86_pmu_attrs[] = {
2592         &dev_attr_rdpmc.attr,
2593         NULL,
2594 };
2595 
2596 static struct attribute_group x86_pmu_attr_group __ro_after_init = {
2597         .attrs = x86_pmu_attrs,
2598 };
2599 
2600 static ssize_t max_precise_show(struct device *cdev,
2601                                   struct device_attribute *attr,
2602                                   char *buf)
2603 {
2604         return snprintf(buf, PAGE_SIZE, "%d\n", x86_pmu_max_precise());
2605 }
2606 
2607 static DEVICE_ATTR_RO(max_precise);
2608 
2609 static struct attribute *x86_pmu_caps_attrs[] = {
2610         &dev_attr_max_precise.attr,
2611         NULL
2612 };
2613 
2614 static struct attribute_group x86_pmu_caps_group __ro_after_init = {
2615         .name = "caps",
2616         .attrs = x86_pmu_caps_attrs,
2617 };
2618 
2619 static const struct attribute_group *x86_pmu_attr_groups[] = {
2620         &x86_pmu_attr_group,
2621         &x86_pmu_format_group,
2622         &x86_pmu_events_group,
2623         &x86_pmu_caps_group,
2624         NULL,
2625 };
2626 
2627 static void x86_pmu_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in)
2628 {
2629         static_call_cond(x86_pmu_sched_task)(pmu_ctx, sched_in);
2630 }
2631 
2632 static void x86_pmu_swap_task_ctx(struct perf_event_pmu_context *prev_epc,
2633                                   struct perf_event_pmu_context *next_epc)
2634 {
2635         static_call_cond(x86_pmu_swap_task_ctx)(prev_epc, next_epc);
2636 }
2637 
2638 void perf_check_microcode(void)
2639 {
2640         if (x86_pmu.check_microcode)
2641                 x86_pmu.check_microcode();
2642 }
2643 
2644 static int x86_pmu_check_period(struct perf_event *event, u64 value)
2645 {
2646         if (x86_pmu.check_period && x86_pmu.check_period(event, value))
2647                 return -EINVAL;
2648 
2649         if (value && x86_pmu.limit_period) {
2650                 s64 left = value;
2651                 x86_pmu.limit_period(event, &left);
2652                 if (left > value)
2653                         return -EINVAL;
2654         }
2655 
2656         return 0;
2657 }
2658 
2659 static int x86_pmu_aux_output_match(struct perf_event *event)
2660 {
2661         if (!(pmu.capabilities & PERF_PMU_CAP_AUX_OUTPUT))
2662                 return 0;
2663 
2664         if (x86_pmu.aux_output_match)
2665                 return x86_pmu.aux_output_match(event);
2666 
2667         return 0;
2668 }
2669 
2670 static bool x86_pmu_filter(struct pmu *pmu, int cpu)
2671 {
2672         bool ret = false;
2673 
2674         static_call_cond(x86_pmu_filter)(pmu, cpu, &ret);
2675 
2676         return ret;
2677 }
2678 
2679 static struct pmu pmu = {
2680         .pmu_enable             = x86_pmu_enable,
2681         .pmu_disable            = x86_pmu_disable,
2682 
2683         .attr_groups            = x86_pmu_attr_groups,
2684 
2685         .event_init             = x86_pmu_event_init,
2686 
2687         .event_mapped           = x86_pmu_event_mapped,
2688         .event_unmapped         = x86_pmu_event_unmapped,
2689 
2690         .add                    = x86_pmu_add,
2691         .del                    = x86_pmu_del,
2692         .start                  = x86_pmu_start,
2693         .stop                   = x86_pmu_stop,
2694         .read                   = x86_pmu_read,
2695 
2696         .start_txn              = x86_pmu_start_txn,
2697         .cancel_txn             = x86_pmu_cancel_txn,
2698         .commit_txn             = x86_pmu_commit_txn,
2699 
2700         .event_idx              = x86_pmu_event_idx,
2701         .sched_task             = x86_pmu_sched_task,
2702         .swap_task_ctx          = x86_pmu_swap_task_ctx,
2703         .check_period           = x86_pmu_check_period,
2704 
2705         .aux_output_match       = x86_pmu_aux_output_match,
2706 
2707         .filter                 = x86_pmu_filter,
2708 };
2709 
2710 void arch_perf_update_userpage(struct perf_event *event,
2711                                struct perf_event_mmap_page *userpg, u64 now)
2712 {
2713         struct cyc2ns_data data;
2714         u64 offset;
2715 
2716         userpg->cap_user_time = 0;
2717         userpg->cap_user_time_zero = 0;
2718         userpg->cap_user_rdpmc =
2719                 !!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT);
2720         userpg->pmc_width = x86_pmu.cntval_bits;
2721 
2722         if (!using_native_sched_clock() || !sched_clock_stable())
2723                 return;
2724 
2725         cyc2ns_read_begin(&data);
2726 
2727         offset = data.cyc2ns_offset + __sched_clock_offset;
2728 
2729         /*
2730          * Internal timekeeping for enabled/running/stopped times
2731          * is always in the local_clock domain.
2732          */
2733         userpg->cap_user_time = 1;
2734         userpg->time_mult = data.cyc2ns_mul;
2735         userpg->time_shift = data.cyc2ns_shift;
2736         userpg->time_offset = offset - now;
2737 
2738         /*
2739          * cap_user_time_zero doesn't make sense when we're using a different
2740          * time base for the records.
2741          */
2742         if (!event->attr.use_clockid) {
2743                 userpg->cap_user_time_zero = 1;
2744                 userpg->time_zero = offset;
2745         }
2746 
2747         cyc2ns_read_end();
2748 }
2749 
2750 /*
2751  * Determine whether the regs were taken from an irq/exception handler rather
2752  * than from perf_arch_fetch_caller_regs().
2753  */
2754 static bool perf_hw_regs(struct pt_regs *regs)
2755 {
2756         return regs->flags & X86_EFLAGS_FIXED;
2757 }
2758 
2759 void
2760 perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
2761 {
2762         struct unwind_state state;
2763         unsigned long addr;
2764 
2765         if (perf_guest_state()) {
2766                 /* TODO: We don't support guest os callchain now */
2767                 return;
2768         }
2769 
2770         if (perf_callchain_store(entry, regs->ip))
2771                 return;
2772 
2773         if (perf_hw_regs(regs))
2774                 unwind_start(&state, current, regs, NULL);
2775         else
2776                 unwind_start(&state, current, NULL, (void *)regs->sp);
2777 
2778         for (; !unwind_done(&state); unwind_next_frame(&state)) {
2779                 addr = unwind_get_return_address(&state);
2780                 if (!addr || perf_callchain_store(entry, addr))
2781                         return;
2782         }
2783 }
2784 
2785 static inline int
2786 valid_user_frame(const void __user *fp, unsigned long size)
2787 {
2788         return __access_ok(fp, size);
2789 }
2790 
2791 static unsigned long get_segment_base(unsigned int segment)
2792 {
2793         struct desc_struct *desc;
2794         unsigned int idx = segment >> 3;
2795 
2796         if ((segment & SEGMENT_TI_MASK) == SEGMENT_LDT) {
2797 #ifdef CONFIG_MODIFY_LDT_SYSCALL
2798                 struct ldt_struct *ldt;
2799 
2800                 /* IRQs are off, so this synchronizes with smp_store_release */
2801                 ldt = READ_ONCE(current->active_mm->context.ldt);
2802                 if (!ldt || idx >= ldt->nr_entries)
2803                         return 0;
2804 
2805                 desc = &ldt->entries[idx];
2806 #else
2807                 return 0;
2808 #endif
2809         } else {
2810                 if (idx >= GDT_ENTRIES)
2811                         return 0;
2812 
2813                 desc = raw_cpu_ptr(gdt_page.gdt) + idx;
2814         }
2815 
2816         return get_desc_base(desc);
2817 }
2818 
2819 #ifdef CONFIG_IA32_EMULATION
2820 
2821 #include <linux/compat.h>
2822 
2823 static inline int
2824 perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *entry)
2825 {
2826         /* 32-bit process in 64-bit kernel. */
2827         unsigned long ss_base, cs_base;
2828         struct stack_frame_ia32 frame;
2829         const struct stack_frame_ia32 __user *fp;
2830 
2831         if (user_64bit_mode(regs))
2832                 return 0;
2833 
2834         cs_base = get_segment_base(regs->cs);
2835         ss_base = get_segment_base(regs->ss);
2836 
2837         fp = compat_ptr(ss_base + regs->bp);
2838         pagefault_disable();
2839         while (entry->nr < entry->max_stack) {
2840                 if (!valid_user_frame(fp, sizeof(frame)))
2841                         break;
2842 
2843                 if (__get_user(frame.next_frame, &fp->next_frame))
2844                         break;
2845                 if (__get_user(frame.return_address, &fp->return_address))
2846                         break;
2847 
2848                 perf_callchain_store(entry, cs_base + frame.return_address);
2849                 fp = compat_ptr(ss_base + frame.next_frame);
2850         }
2851         pagefault_enable();
2852         return 1;
2853 }
2854 #else
2855 static inline int
2856 perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *entry)
2857 {
2858     return 0;
2859 }
2860 #endif
2861 
2862 void
2863 perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
2864 {
2865         struct stack_frame frame;
2866         const struct stack_frame __user *fp;
2867 
2868         if (perf_guest_state()) {
2869                 /* TODO: We don't support guest os callchain now */
2870                 return;
2871         }
2872 
2873         /*
2874          * We don't know what to do with VM86 stacks.. ignore them for now.
2875          */
2876         if (regs->flags & (X86_VM_MASK | PERF_EFLAGS_VM))
2877                 return;
2878 
2879         fp = (void __user *)regs->bp;
2880 
2881         perf_callchain_store(entry, regs->ip);
2882 
2883         if (!nmi_uaccess_okay())
2884                 return;
2885 
2886         if (perf_callchain_user32(regs, entry))
2887                 return;
2888 
2889         pagefault_disable();
2890         while (entry->nr < entry->max_stack) {
2891                 if (!valid_user_frame(fp, sizeof(frame)))
2892                         break;
2893 
2894                 if (__get_user(frame.next_frame, &fp->next_frame))
2895                         break;
2896                 if (__get_user(frame.return_address, &fp->return_address))
2897                         break;
2898 
2899                 perf_callchain_store(entry, frame.return_address);
2900                 fp = (void __user *)frame.next_frame;
2901         }
2902         pagefault_enable();
2903 }
2904 
2905 /*
2906  * Deal with code segment offsets for the various execution modes:
2907  *
2908  *   VM86 - the good olde 16 bit days, where the linear address is
2909  *          20 bits and we use regs->ip + 0x10 * regs->cs.
2910  *
2911  *   IA32 - Where we need to look at GDT/LDT segment descriptor tables
2912  *          to figure out what the 32bit base address is.
2913  *
2914  *    X32 - has TIF_X32 set, but is running in x86_64
2915  *
2916  * X86_64 - CS,DS,SS,ES are all zero based.
2917  */
2918 static unsigned long code_segment_base(struct pt_regs *regs)
2919 {
2920         /*
2921          * For IA32 we look at the GDT/LDT segment base to convert the
2922          * effective IP to a linear address.
2923          */
2924 
2925 #ifdef CONFIG_X86_32
2926         /*
2927          * If we are in VM86 mode, add the segment offset to convert to a
2928          * linear address.
2929          */
2930         if (regs->flags & X86_VM_MASK)
2931                 return 0x10 * regs->cs;
2932 
2933         if (user_mode(regs) && regs->cs != __USER_CS)
2934                 return get_segment_base(regs->cs);
2935 #else
2936         if (user_mode(regs) && !user_64bit_mode(regs) &&
2937             regs->cs != __USER32_CS)
2938                 return get_segment_base(regs->cs);
2939 #endif
2940         return 0;
2941 }
2942 
2943 unsigned long perf_instruction_pointer(struct pt_regs *regs)
2944 {
2945         if (perf_guest_state())
2946                 return perf_guest_get_ip();
2947 
2948         return regs->ip + code_segment_base(regs);
2949 }
2950 
2951 unsigned long perf_misc_flags(struct pt_regs *regs)
2952 {
2953         unsigned int guest_state = perf_guest_state();
2954         int misc = 0;
2955 
2956         if (guest_state) {
2957                 if (guest_state & PERF_GUEST_USER)
2958                         misc |= PERF_RECORD_MISC_GUEST_USER;
2959                 else
2960                         misc |= PERF_RECORD_MISC_GUEST_KERNEL;
2961         } else {
2962                 if (user_mode(regs))
2963                         misc |= PERF_RECORD_MISC_USER;
2964                 else
2965                         misc |= PERF_RECORD_MISC_KERNEL;
2966         }
2967 
2968         if (regs->flags & PERF_EFLAGS_EXACT)
2969                 misc |= PERF_RECORD_MISC_EXACT_IP;
2970 
2971         return misc;
2972 }
2973 
2974 void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap)
2975 {
2976         /* This API doesn't currently support enumerating hybrid PMUs. */
2977         if (WARN_ON_ONCE(cpu_feature_enabled(X86_FEATURE_HYBRID_CPU)) ||
2978             !x86_pmu_initialized()) {
2979                 memset(cap, 0, sizeof(*cap));
2980                 return;
2981         }
2982 
2983         /*
2984          * Note, hybrid CPU models get tracked as having hybrid PMUs even when
2985          * all E-cores are disabled via BIOS.  When E-cores are disabled, the
2986          * base PMU holds the correct number of counters for P-cores.
2987          */
2988         cap->version            = x86_pmu.version;
2989         cap->num_counters_gp    = x86_pmu_num_counters(NULL);
2990         cap->num_counters_fixed = x86_pmu_num_counters_fixed(NULL);
2991         cap->bit_width_gp       = x86_pmu.cntval_bits;
2992         cap->bit_width_fixed    = x86_pmu.cntval_bits;
2993         cap->events_mask        = (unsigned int)x86_pmu.events_maskl;
2994         cap->events_mask_len    = x86_pmu.events_mask_len;
2995         cap->pebs_ept           = x86_pmu.pebs_ept;
2996 }
2997 EXPORT_SYMBOL_GPL(perf_get_x86_pmu_capability);
2998 
2999 u64 perf_get_hw_event_config(int hw_event)
3000 {
3001         int max = x86_pmu.max_events;
3002 
3003         if (hw_event < max)
3004                 return x86_pmu.event_map(array_index_nospec(hw_event, max));
3005 
3006         return 0;
3007 }
3008 EXPORT_SYMBOL_GPL(perf_get_hw_event_config);
3009 

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