xref: /linux/arch/x86/events/intel/ds.c (revision 18f90d372cf35b387663f1567de701e5393f6eb5)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/bitops.h>
3 #include <linux/types.h>
4 #include <linux/slab.h>
5 
6 #include <asm/cpu_entry_area.h>
7 #include <asm/perf_event.h>
8 #include <asm/tlbflush.h>
9 #include <asm/insn.h>
10 
11 #include "../perf_event.h"
12 
13 /* Waste a full page so it can be mapped into the cpu_entry_area */
14 DEFINE_PER_CPU_PAGE_ALIGNED(struct debug_store, cpu_debug_store);
15 
16 /* The size of a BTS record in bytes: */
17 #define BTS_RECORD_SIZE		24
18 
19 #define PEBS_FIXUP_SIZE		PAGE_SIZE
20 
21 /*
22  * pebs_record_32 for p4 and core not supported
23 
24 struct pebs_record_32 {
25 	u32 flags, ip;
26 	u32 ax, bc, cx, dx;
27 	u32 si, di, bp, sp;
28 };
29 
30  */
31 
32 union intel_x86_pebs_dse {
33 	u64 val;
34 	struct {
35 		unsigned int ld_dse:4;
36 		unsigned int ld_stlb_miss:1;
37 		unsigned int ld_locked:1;
38 		unsigned int ld_reserved:26;
39 	};
40 	struct {
41 		unsigned int st_l1d_hit:1;
42 		unsigned int st_reserved1:3;
43 		unsigned int st_stlb_miss:1;
44 		unsigned int st_locked:1;
45 		unsigned int st_reserved2:26;
46 	};
47 };
48 
49 
50 /*
51  * Map PEBS Load Latency Data Source encodings to generic
52  * memory data source information
53  */
54 #define P(a, b) PERF_MEM_S(a, b)
55 #define OP_LH (P(OP, LOAD) | P(LVL, HIT))
56 #define LEVEL(x) P(LVLNUM, x)
57 #define REM P(REMOTE, REMOTE)
58 #define SNOOP_NONE_MISS (P(SNOOP, NONE) | P(SNOOP, MISS))
59 
60 /* Version for Sandy Bridge and later */
61 static u64 pebs_data_source[] = {
62 	P(OP, LOAD) | P(LVL, MISS) | LEVEL(L3) | P(SNOOP, NA),/* 0x00:ukn L3 */
63 	OP_LH | P(LVL, L1)  | LEVEL(L1) | P(SNOOP, NONE),  /* 0x01: L1 local */
64 	OP_LH | P(LVL, LFB) | LEVEL(LFB) | P(SNOOP, NONE), /* 0x02: LFB hit */
65 	OP_LH | P(LVL, L2)  | LEVEL(L2) | P(SNOOP, NONE),  /* 0x03: L2 hit */
66 	OP_LH | P(LVL, L3)  | LEVEL(L3) | P(SNOOP, NONE),  /* 0x04: L3 hit */
67 	OP_LH | P(LVL, L3)  | LEVEL(L3) | P(SNOOP, MISS),  /* 0x05: L3 hit, snoop miss */
68 	OP_LH | P(LVL, L3)  | LEVEL(L3) | P(SNOOP, HIT),   /* 0x06: L3 hit, snoop hit */
69 	OP_LH | P(LVL, L3)  | LEVEL(L3) | P(SNOOP, HITM),  /* 0x07: L3 hit, snoop hitm */
70 	OP_LH | P(LVL, REM_CCE1) | REM | LEVEL(L3) | P(SNOOP, HIT),  /* 0x08: L3 miss snoop hit */
71 	OP_LH | P(LVL, REM_CCE1) | REM | LEVEL(L3) | P(SNOOP, HITM), /* 0x09: L3 miss snoop hitm*/
72 	OP_LH | P(LVL, LOC_RAM)  | LEVEL(RAM) | P(SNOOP, HIT),       /* 0x0a: L3 miss, shared */
73 	OP_LH | P(LVL, REM_RAM1) | REM | LEVEL(L3) | P(SNOOP, HIT),  /* 0x0b: L3 miss, shared */
74 	OP_LH | P(LVL, LOC_RAM)  | LEVEL(RAM) | SNOOP_NONE_MISS,     /* 0x0c: L3 miss, excl */
75 	OP_LH | P(LVL, REM_RAM1) | LEVEL(RAM) | REM | SNOOP_NONE_MISS, /* 0x0d: L3 miss, excl */
76 	OP_LH | P(LVL, IO)  | LEVEL(NA) | P(SNOOP, NONE), /* 0x0e: I/O */
77 	OP_LH | P(LVL, UNC) | LEVEL(NA) | P(SNOOP, NONE), /* 0x0f: uncached */
78 };
79 
80 /* Patch up minor differences in the bits */
81 void __init intel_pmu_pebs_data_source_nhm(void)
82 {
83 	pebs_data_source[0x05] = OP_LH | P(LVL, L3) | LEVEL(L3) | P(SNOOP, HIT);
84 	pebs_data_source[0x06] = OP_LH | P(LVL, L3) | LEVEL(L3) | P(SNOOP, HITM);
85 	pebs_data_source[0x07] = OP_LH | P(LVL, L3) | LEVEL(L3) | P(SNOOP, HITM);
86 }
87 
88 void __init intel_pmu_pebs_data_source_skl(bool pmem)
89 {
90 	u64 pmem_or_l4 = pmem ? LEVEL(PMEM) : LEVEL(L4);
91 
92 	pebs_data_source[0x08] = OP_LH | pmem_or_l4 | P(SNOOP, HIT);
93 	pebs_data_source[0x09] = OP_LH | pmem_or_l4 | REM | P(SNOOP, HIT);
94 	pebs_data_source[0x0b] = OP_LH | LEVEL(RAM) | REM | P(SNOOP, NONE);
95 	pebs_data_source[0x0c] = OP_LH | LEVEL(ANY_CACHE) | REM | P(SNOOPX, FWD);
96 	pebs_data_source[0x0d] = OP_LH | LEVEL(ANY_CACHE) | REM | P(SNOOP, HITM);
97 }
98 
99 static u64 precise_store_data(u64 status)
100 {
101 	union intel_x86_pebs_dse dse;
102 	u64 val = P(OP, STORE) | P(SNOOP, NA) | P(LVL, L1) | P(TLB, L2);
103 
104 	dse.val = status;
105 
106 	/*
107 	 * bit 4: TLB access
108 	 * 1 = stored missed 2nd level TLB
109 	 *
110 	 * so it either hit the walker or the OS
111 	 * otherwise hit 2nd level TLB
112 	 */
113 	if (dse.st_stlb_miss)
114 		val |= P(TLB, MISS);
115 	else
116 		val |= P(TLB, HIT);
117 
118 	/*
119 	 * bit 0: hit L1 data cache
120 	 * if not set, then all we know is that
121 	 * it missed L1D
122 	 */
123 	if (dse.st_l1d_hit)
124 		val |= P(LVL, HIT);
125 	else
126 		val |= P(LVL, MISS);
127 
128 	/*
129 	 * bit 5: Locked prefix
130 	 */
131 	if (dse.st_locked)
132 		val |= P(LOCK, LOCKED);
133 
134 	return val;
135 }
136 
137 static u64 precise_datala_hsw(struct perf_event *event, u64 status)
138 {
139 	union perf_mem_data_src dse;
140 
141 	dse.val = PERF_MEM_NA;
142 
143 	if (event->hw.flags & PERF_X86_EVENT_PEBS_ST_HSW)
144 		dse.mem_op = PERF_MEM_OP_STORE;
145 	else if (event->hw.flags & PERF_X86_EVENT_PEBS_LD_HSW)
146 		dse.mem_op = PERF_MEM_OP_LOAD;
147 
148 	/*
149 	 * L1 info only valid for following events:
150 	 *
151 	 * MEM_UOPS_RETIRED.STLB_MISS_STORES
152 	 * MEM_UOPS_RETIRED.LOCK_STORES
153 	 * MEM_UOPS_RETIRED.SPLIT_STORES
154 	 * MEM_UOPS_RETIRED.ALL_STORES
155 	 */
156 	if (event->hw.flags & PERF_X86_EVENT_PEBS_ST_HSW) {
157 		if (status & 1)
158 			dse.mem_lvl = PERF_MEM_LVL_L1 | PERF_MEM_LVL_HIT;
159 		else
160 			dse.mem_lvl = PERF_MEM_LVL_L1 | PERF_MEM_LVL_MISS;
161 	}
162 	return dse.val;
163 }
164 
165 static u64 load_latency_data(u64 status)
166 {
167 	union intel_x86_pebs_dse dse;
168 	u64 val;
169 
170 	dse.val = status;
171 
172 	/*
173 	 * use the mapping table for bit 0-3
174 	 */
175 	val = pebs_data_source[dse.ld_dse];
176 
177 	/*
178 	 * Nehalem models do not support TLB, Lock infos
179 	 */
180 	if (x86_pmu.pebs_no_tlb) {
181 		val |= P(TLB, NA) | P(LOCK, NA);
182 		return val;
183 	}
184 	/*
185 	 * bit 4: TLB access
186 	 * 0 = did not miss 2nd level TLB
187 	 * 1 = missed 2nd level TLB
188 	 */
189 	if (dse.ld_stlb_miss)
190 		val |= P(TLB, MISS) | P(TLB, L2);
191 	else
192 		val |= P(TLB, HIT) | P(TLB, L1) | P(TLB, L2);
193 
194 	/*
195 	 * bit 5: locked prefix
196 	 */
197 	if (dse.ld_locked)
198 		val |= P(LOCK, LOCKED);
199 
200 	return val;
201 }
202 
203 struct pebs_record_core {
204 	u64 flags, ip;
205 	u64 ax, bx, cx, dx;
206 	u64 si, di, bp, sp;
207 	u64 r8,  r9,  r10, r11;
208 	u64 r12, r13, r14, r15;
209 };
210 
211 struct pebs_record_nhm {
212 	u64 flags, ip;
213 	u64 ax, bx, cx, dx;
214 	u64 si, di, bp, sp;
215 	u64 r8,  r9,  r10, r11;
216 	u64 r12, r13, r14, r15;
217 	u64 status, dla, dse, lat;
218 };
219 
220 /*
221  * Same as pebs_record_nhm, with two additional fields.
222  */
223 struct pebs_record_hsw {
224 	u64 flags, ip;
225 	u64 ax, bx, cx, dx;
226 	u64 si, di, bp, sp;
227 	u64 r8,  r9,  r10, r11;
228 	u64 r12, r13, r14, r15;
229 	u64 status, dla, dse, lat;
230 	u64 real_ip, tsx_tuning;
231 };
232 
233 union hsw_tsx_tuning {
234 	struct {
235 		u32 cycles_last_block     : 32,
236 		    hle_abort		  : 1,
237 		    rtm_abort		  : 1,
238 		    instruction_abort     : 1,
239 		    non_instruction_abort : 1,
240 		    retry		  : 1,
241 		    data_conflict	  : 1,
242 		    capacity_writes	  : 1,
243 		    capacity_reads	  : 1;
244 	};
245 	u64	    value;
246 };
247 
248 #define PEBS_HSW_TSX_FLAGS	0xff00000000ULL
249 
250 /* Same as HSW, plus TSC */
251 
252 struct pebs_record_skl {
253 	u64 flags, ip;
254 	u64 ax, bx, cx, dx;
255 	u64 si, di, bp, sp;
256 	u64 r8,  r9,  r10, r11;
257 	u64 r12, r13, r14, r15;
258 	u64 status, dla, dse, lat;
259 	u64 real_ip, tsx_tuning;
260 	u64 tsc;
261 };
262 
263 void init_debug_store_on_cpu(int cpu)
264 {
265 	struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
266 
267 	if (!ds)
268 		return;
269 
270 	wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA,
271 		     (u32)((u64)(unsigned long)ds),
272 		     (u32)((u64)(unsigned long)ds >> 32));
273 }
274 
275 void fini_debug_store_on_cpu(int cpu)
276 {
277 	if (!per_cpu(cpu_hw_events, cpu).ds)
278 		return;
279 
280 	wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA, 0, 0);
281 }
282 
283 static DEFINE_PER_CPU(void *, insn_buffer);
284 
285 static void ds_update_cea(void *cea, void *addr, size_t size, pgprot_t prot)
286 {
287 	unsigned long start = (unsigned long)cea;
288 	phys_addr_t pa;
289 	size_t msz = 0;
290 
291 	pa = virt_to_phys(addr);
292 
293 	preempt_disable();
294 	for (; msz < size; msz += PAGE_SIZE, pa += PAGE_SIZE, cea += PAGE_SIZE)
295 		cea_set_pte(cea, pa, prot);
296 
297 	/*
298 	 * This is a cross-CPU update of the cpu_entry_area, we must shoot down
299 	 * all TLB entries for it.
300 	 */
301 	flush_tlb_kernel_range(start, start + size);
302 	preempt_enable();
303 }
304 
305 static void ds_clear_cea(void *cea, size_t size)
306 {
307 	unsigned long start = (unsigned long)cea;
308 	size_t msz = 0;
309 
310 	preempt_disable();
311 	for (; msz < size; msz += PAGE_SIZE, cea += PAGE_SIZE)
312 		cea_set_pte(cea, 0, PAGE_NONE);
313 
314 	flush_tlb_kernel_range(start, start + size);
315 	preempt_enable();
316 }
317 
318 static void *dsalloc_pages(size_t size, gfp_t flags, int cpu)
319 {
320 	unsigned int order = get_order(size);
321 	int node = cpu_to_node(cpu);
322 	struct page *page;
323 
324 	page = __alloc_pages_node(node, flags | __GFP_ZERO, order);
325 	return page ? page_address(page) : NULL;
326 }
327 
328 static void dsfree_pages(const void *buffer, size_t size)
329 {
330 	if (buffer)
331 		free_pages((unsigned long)buffer, get_order(size));
332 }
333 
334 static int alloc_pebs_buffer(int cpu)
335 {
336 	struct cpu_hw_events *hwev = per_cpu_ptr(&cpu_hw_events, cpu);
337 	struct debug_store *ds = hwev->ds;
338 	size_t bsiz = x86_pmu.pebs_buffer_size;
339 	int max, node = cpu_to_node(cpu);
340 	void *buffer, *ibuffer, *cea;
341 
342 	if (!x86_pmu.pebs)
343 		return 0;
344 
345 	buffer = dsalloc_pages(bsiz, GFP_KERNEL, cpu);
346 	if (unlikely(!buffer))
347 		return -ENOMEM;
348 
349 	/*
350 	 * HSW+ already provides us the eventing ip; no need to allocate this
351 	 * buffer then.
352 	 */
353 	if (x86_pmu.intel_cap.pebs_format < 2) {
354 		ibuffer = kzalloc_node(PEBS_FIXUP_SIZE, GFP_KERNEL, node);
355 		if (!ibuffer) {
356 			dsfree_pages(buffer, bsiz);
357 			return -ENOMEM;
358 		}
359 		per_cpu(insn_buffer, cpu) = ibuffer;
360 	}
361 	hwev->ds_pebs_vaddr = buffer;
362 	/* Update the cpu entry area mapping */
363 	cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.pebs_buffer;
364 	ds->pebs_buffer_base = (unsigned long) cea;
365 	ds_update_cea(cea, buffer, bsiz, PAGE_KERNEL);
366 	ds->pebs_index = ds->pebs_buffer_base;
367 	max = x86_pmu.pebs_record_size * (bsiz / x86_pmu.pebs_record_size);
368 	ds->pebs_absolute_maximum = ds->pebs_buffer_base + max;
369 	return 0;
370 }
371 
372 static void release_pebs_buffer(int cpu)
373 {
374 	struct cpu_hw_events *hwev = per_cpu_ptr(&cpu_hw_events, cpu);
375 	void *cea;
376 
377 	if (!x86_pmu.pebs)
378 		return;
379 
380 	kfree(per_cpu(insn_buffer, cpu));
381 	per_cpu(insn_buffer, cpu) = NULL;
382 
383 	/* Clear the fixmap */
384 	cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.pebs_buffer;
385 	ds_clear_cea(cea, x86_pmu.pebs_buffer_size);
386 	dsfree_pages(hwev->ds_pebs_vaddr, x86_pmu.pebs_buffer_size);
387 	hwev->ds_pebs_vaddr = NULL;
388 }
389 
390 static int alloc_bts_buffer(int cpu)
391 {
392 	struct cpu_hw_events *hwev = per_cpu_ptr(&cpu_hw_events, cpu);
393 	struct debug_store *ds = hwev->ds;
394 	void *buffer, *cea;
395 	int max;
396 
397 	if (!x86_pmu.bts)
398 		return 0;
399 
400 	buffer = dsalloc_pages(BTS_BUFFER_SIZE, GFP_KERNEL | __GFP_NOWARN, cpu);
401 	if (unlikely(!buffer)) {
402 		WARN_ONCE(1, "%s: BTS buffer allocation failure\n", __func__);
403 		return -ENOMEM;
404 	}
405 	hwev->ds_bts_vaddr = buffer;
406 	/* Update the fixmap */
407 	cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.bts_buffer;
408 	ds->bts_buffer_base = (unsigned long) cea;
409 	ds_update_cea(cea, buffer, BTS_BUFFER_SIZE, PAGE_KERNEL);
410 	ds->bts_index = ds->bts_buffer_base;
411 	max = BTS_BUFFER_SIZE / BTS_RECORD_SIZE;
412 	ds->bts_absolute_maximum = ds->bts_buffer_base +
413 					max * BTS_RECORD_SIZE;
414 	ds->bts_interrupt_threshold = ds->bts_absolute_maximum -
415 					(max / 16) * BTS_RECORD_SIZE;
416 	return 0;
417 }
418 
419 static void release_bts_buffer(int cpu)
420 {
421 	struct cpu_hw_events *hwev = per_cpu_ptr(&cpu_hw_events, cpu);
422 	void *cea;
423 
424 	if (!x86_pmu.bts)
425 		return;
426 
427 	/* Clear the fixmap */
428 	cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.bts_buffer;
429 	ds_clear_cea(cea, BTS_BUFFER_SIZE);
430 	dsfree_pages(hwev->ds_bts_vaddr, BTS_BUFFER_SIZE);
431 	hwev->ds_bts_vaddr = NULL;
432 }
433 
434 static int alloc_ds_buffer(int cpu)
435 {
436 	struct debug_store *ds = &get_cpu_entry_area(cpu)->cpu_debug_store;
437 
438 	memset(ds, 0, sizeof(*ds));
439 	per_cpu(cpu_hw_events, cpu).ds = ds;
440 	return 0;
441 }
442 
443 static void release_ds_buffer(int cpu)
444 {
445 	per_cpu(cpu_hw_events, cpu).ds = NULL;
446 }
447 
448 void release_ds_buffers(void)
449 {
450 	int cpu;
451 
452 	if (!x86_pmu.bts && !x86_pmu.pebs)
453 		return;
454 
455 	for_each_possible_cpu(cpu)
456 		release_ds_buffer(cpu);
457 
458 	for_each_possible_cpu(cpu) {
459 		/*
460 		 * Again, ignore errors from offline CPUs, they will no longer
461 		 * observe cpu_hw_events.ds and not program the DS_AREA when
462 		 * they come up.
463 		 */
464 		fini_debug_store_on_cpu(cpu);
465 	}
466 
467 	for_each_possible_cpu(cpu) {
468 		release_pebs_buffer(cpu);
469 		release_bts_buffer(cpu);
470 	}
471 }
472 
473 void reserve_ds_buffers(void)
474 {
475 	int bts_err = 0, pebs_err = 0;
476 	int cpu;
477 
478 	x86_pmu.bts_active = 0;
479 	x86_pmu.pebs_active = 0;
480 
481 	if (!x86_pmu.bts && !x86_pmu.pebs)
482 		return;
483 
484 	if (!x86_pmu.bts)
485 		bts_err = 1;
486 
487 	if (!x86_pmu.pebs)
488 		pebs_err = 1;
489 
490 	for_each_possible_cpu(cpu) {
491 		if (alloc_ds_buffer(cpu)) {
492 			bts_err = 1;
493 			pebs_err = 1;
494 		}
495 
496 		if (!bts_err && alloc_bts_buffer(cpu))
497 			bts_err = 1;
498 
499 		if (!pebs_err && alloc_pebs_buffer(cpu))
500 			pebs_err = 1;
501 
502 		if (bts_err && pebs_err)
503 			break;
504 	}
505 
506 	if (bts_err) {
507 		for_each_possible_cpu(cpu)
508 			release_bts_buffer(cpu);
509 	}
510 
511 	if (pebs_err) {
512 		for_each_possible_cpu(cpu)
513 			release_pebs_buffer(cpu);
514 	}
515 
516 	if (bts_err && pebs_err) {
517 		for_each_possible_cpu(cpu)
518 			release_ds_buffer(cpu);
519 	} else {
520 		if (x86_pmu.bts && !bts_err)
521 			x86_pmu.bts_active = 1;
522 
523 		if (x86_pmu.pebs && !pebs_err)
524 			x86_pmu.pebs_active = 1;
525 
526 		for_each_possible_cpu(cpu) {
527 			/*
528 			 * Ignores wrmsr_on_cpu() errors for offline CPUs they
529 			 * will get this call through intel_pmu_cpu_starting().
530 			 */
531 			init_debug_store_on_cpu(cpu);
532 		}
533 	}
534 }
535 
536 /*
537  * BTS
538  */
539 
540 struct event_constraint bts_constraint =
541 	EVENT_CONSTRAINT(0, 1ULL << INTEL_PMC_IDX_FIXED_BTS, 0);
542 
543 void intel_pmu_enable_bts(u64 config)
544 {
545 	unsigned long debugctlmsr;
546 
547 	debugctlmsr = get_debugctlmsr();
548 
549 	debugctlmsr |= DEBUGCTLMSR_TR;
550 	debugctlmsr |= DEBUGCTLMSR_BTS;
551 	if (config & ARCH_PERFMON_EVENTSEL_INT)
552 		debugctlmsr |= DEBUGCTLMSR_BTINT;
553 
554 	if (!(config & ARCH_PERFMON_EVENTSEL_OS))
555 		debugctlmsr |= DEBUGCTLMSR_BTS_OFF_OS;
556 
557 	if (!(config & ARCH_PERFMON_EVENTSEL_USR))
558 		debugctlmsr |= DEBUGCTLMSR_BTS_OFF_USR;
559 
560 	update_debugctlmsr(debugctlmsr);
561 }
562 
563 void intel_pmu_disable_bts(void)
564 {
565 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
566 	unsigned long debugctlmsr;
567 
568 	if (!cpuc->ds)
569 		return;
570 
571 	debugctlmsr = get_debugctlmsr();
572 
573 	debugctlmsr &=
574 		~(DEBUGCTLMSR_TR | DEBUGCTLMSR_BTS | DEBUGCTLMSR_BTINT |
575 		  DEBUGCTLMSR_BTS_OFF_OS | DEBUGCTLMSR_BTS_OFF_USR);
576 
577 	update_debugctlmsr(debugctlmsr);
578 }
579 
580 int intel_pmu_drain_bts_buffer(void)
581 {
582 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
583 	struct debug_store *ds = cpuc->ds;
584 	struct bts_record {
585 		u64	from;
586 		u64	to;
587 		u64	flags;
588 	};
589 	struct perf_event *event = cpuc->events[INTEL_PMC_IDX_FIXED_BTS];
590 	struct bts_record *at, *base, *top;
591 	struct perf_output_handle handle;
592 	struct perf_event_header header;
593 	struct perf_sample_data data;
594 	unsigned long skip = 0;
595 	struct pt_regs regs;
596 
597 	if (!event)
598 		return 0;
599 
600 	if (!x86_pmu.bts_active)
601 		return 0;
602 
603 	base = (struct bts_record *)(unsigned long)ds->bts_buffer_base;
604 	top  = (struct bts_record *)(unsigned long)ds->bts_index;
605 
606 	if (top <= base)
607 		return 0;
608 
609 	memset(&regs, 0, sizeof(regs));
610 
611 	ds->bts_index = ds->bts_buffer_base;
612 
613 	perf_sample_data_init(&data, 0, event->hw.last_period);
614 
615 	/*
616 	 * BTS leaks kernel addresses in branches across the cpl boundary,
617 	 * such as traps or system calls, so unless the user is asking for
618 	 * kernel tracing (and right now it's not possible), we'd need to
619 	 * filter them out. But first we need to count how many of those we
620 	 * have in the current batch. This is an extra O(n) pass, however,
621 	 * it's much faster than the other one especially considering that
622 	 * n <= 2560 (BTS_BUFFER_SIZE / BTS_RECORD_SIZE * 15/16; see the
623 	 * alloc_bts_buffer()).
624 	 */
625 	for (at = base; at < top; at++) {
626 		/*
627 		 * Note that right now *this* BTS code only works if
628 		 * attr::exclude_kernel is set, but let's keep this extra
629 		 * check here in case that changes.
630 		 */
631 		if (event->attr.exclude_kernel &&
632 		    (kernel_ip(at->from) || kernel_ip(at->to)))
633 			skip++;
634 	}
635 
636 	/*
637 	 * Prepare a generic sample, i.e. fill in the invariant fields.
638 	 * We will overwrite the from and to address before we output
639 	 * the sample.
640 	 */
641 	rcu_read_lock();
642 	perf_prepare_sample(&header, &data, event, &regs);
643 
644 	if (perf_output_begin(&handle, event, header.size *
645 			      (top - base - skip)))
646 		goto unlock;
647 
648 	for (at = base; at < top; at++) {
649 		/* Filter out any records that contain kernel addresses. */
650 		if (event->attr.exclude_kernel &&
651 		    (kernel_ip(at->from) || kernel_ip(at->to)))
652 			continue;
653 
654 		data.ip		= at->from;
655 		data.addr	= at->to;
656 
657 		perf_output_sample(&handle, &header, &data, event);
658 	}
659 
660 	perf_output_end(&handle);
661 
662 	/* There's new data available. */
663 	event->hw.interrupts++;
664 	event->pending_kill = POLL_IN;
665 unlock:
666 	rcu_read_unlock();
667 	return 1;
668 }
669 
670 static inline void intel_pmu_drain_pebs_buffer(void)
671 {
672 	struct pt_regs regs;
673 
674 	x86_pmu.drain_pebs(&regs);
675 }
676 
677 /*
678  * PEBS
679  */
680 struct event_constraint intel_core2_pebs_event_constraints[] = {
681 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x00c0, 0x1), /* INST_RETIRED.ANY */
682 	INTEL_FLAGS_UEVENT_CONSTRAINT(0xfec1, 0x1), /* X87_OPS_RETIRED.ANY */
683 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x00c5, 0x1), /* BR_INST_RETIRED.MISPRED */
684 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x1fc7, 0x1), /* SIMD_INST_RETURED.ANY */
685 	INTEL_FLAGS_EVENT_CONSTRAINT(0xcb, 0x1),    /* MEM_LOAD_RETIRED.* */
686 	/* INST_RETIRED.ANY_P, inv=1, cmask=16 (cycles:p). */
687 	INTEL_FLAGS_EVENT_CONSTRAINT(0x108000c0, 0x01),
688 	EVENT_CONSTRAINT_END
689 };
690 
691 struct event_constraint intel_atom_pebs_event_constraints[] = {
692 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x00c0, 0x1), /* INST_RETIRED.ANY */
693 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x00c5, 0x1), /* MISPREDICTED_BRANCH_RETIRED */
694 	INTEL_FLAGS_EVENT_CONSTRAINT(0xcb, 0x1),    /* MEM_LOAD_RETIRED.* */
695 	/* INST_RETIRED.ANY_P, inv=1, cmask=16 (cycles:p). */
696 	INTEL_FLAGS_EVENT_CONSTRAINT(0x108000c0, 0x01),
697 	/* Allow all events as PEBS with no flags */
698 	INTEL_ALL_EVENT_CONSTRAINT(0, 0x1),
699 	EVENT_CONSTRAINT_END
700 };
701 
702 struct event_constraint intel_slm_pebs_event_constraints[] = {
703 	/* INST_RETIRED.ANY_P, inv=1, cmask=16 (cycles:p). */
704 	INTEL_FLAGS_EVENT_CONSTRAINT(0x108000c0, 0x1),
705 	/* Allow all events as PEBS with no flags */
706 	INTEL_ALL_EVENT_CONSTRAINT(0, 0x1),
707 	EVENT_CONSTRAINT_END
708 };
709 
710 struct event_constraint intel_glm_pebs_event_constraints[] = {
711 	/* Allow all events as PEBS with no flags */
712 	INTEL_ALL_EVENT_CONSTRAINT(0, 0x1),
713 	EVENT_CONSTRAINT_END
714 };
715 
716 struct event_constraint intel_nehalem_pebs_event_constraints[] = {
717 	INTEL_PLD_CONSTRAINT(0x100b, 0xf),      /* MEM_INST_RETIRED.* */
718 	INTEL_FLAGS_EVENT_CONSTRAINT(0x0f, 0xf),    /* MEM_UNCORE_RETIRED.* */
719 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x010c, 0xf), /* MEM_STORE_RETIRED.DTLB_MISS */
720 	INTEL_FLAGS_EVENT_CONSTRAINT(0xc0, 0xf),    /* INST_RETIRED.ANY */
721 	INTEL_EVENT_CONSTRAINT(0xc2, 0xf),    /* UOPS_RETIRED.* */
722 	INTEL_FLAGS_EVENT_CONSTRAINT(0xc4, 0xf),    /* BR_INST_RETIRED.* */
723 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x02c5, 0xf), /* BR_MISP_RETIRED.NEAR_CALL */
724 	INTEL_FLAGS_EVENT_CONSTRAINT(0xc7, 0xf),    /* SSEX_UOPS_RETIRED.* */
725 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x20c8, 0xf), /* ITLB_MISS_RETIRED */
726 	INTEL_FLAGS_EVENT_CONSTRAINT(0xcb, 0xf),    /* MEM_LOAD_RETIRED.* */
727 	INTEL_FLAGS_EVENT_CONSTRAINT(0xf7, 0xf),    /* FP_ASSIST.* */
728 	/* INST_RETIRED.ANY_P, inv=1, cmask=16 (cycles:p). */
729 	INTEL_FLAGS_EVENT_CONSTRAINT(0x108000c0, 0x0f),
730 	EVENT_CONSTRAINT_END
731 };
732 
733 struct event_constraint intel_westmere_pebs_event_constraints[] = {
734 	INTEL_PLD_CONSTRAINT(0x100b, 0xf),      /* MEM_INST_RETIRED.* */
735 	INTEL_FLAGS_EVENT_CONSTRAINT(0x0f, 0xf),    /* MEM_UNCORE_RETIRED.* */
736 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x010c, 0xf), /* MEM_STORE_RETIRED.DTLB_MISS */
737 	INTEL_FLAGS_EVENT_CONSTRAINT(0xc0, 0xf),    /* INSTR_RETIRED.* */
738 	INTEL_EVENT_CONSTRAINT(0xc2, 0xf),    /* UOPS_RETIRED.* */
739 	INTEL_FLAGS_EVENT_CONSTRAINT(0xc4, 0xf),    /* BR_INST_RETIRED.* */
740 	INTEL_FLAGS_EVENT_CONSTRAINT(0xc5, 0xf),    /* BR_MISP_RETIRED.* */
741 	INTEL_FLAGS_EVENT_CONSTRAINT(0xc7, 0xf),    /* SSEX_UOPS_RETIRED.* */
742 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x20c8, 0xf), /* ITLB_MISS_RETIRED */
743 	INTEL_FLAGS_EVENT_CONSTRAINT(0xcb, 0xf),    /* MEM_LOAD_RETIRED.* */
744 	INTEL_FLAGS_EVENT_CONSTRAINT(0xf7, 0xf),    /* FP_ASSIST.* */
745 	/* INST_RETIRED.ANY_P, inv=1, cmask=16 (cycles:p). */
746 	INTEL_FLAGS_EVENT_CONSTRAINT(0x108000c0, 0x0f),
747 	EVENT_CONSTRAINT_END
748 };
749 
750 struct event_constraint intel_snb_pebs_event_constraints[] = {
751 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x01c0, 0x2), /* INST_RETIRED.PRECDIST */
752 	INTEL_PLD_CONSTRAINT(0x01cd, 0x8),    /* MEM_TRANS_RETIRED.LAT_ABOVE_THR */
753 	INTEL_PST_CONSTRAINT(0x02cd, 0x8),    /* MEM_TRANS_RETIRED.PRECISE_STORES */
754 	/* UOPS_RETIRED.ALL, inv=1, cmask=16 (cycles:p). */
755 	INTEL_FLAGS_EVENT_CONSTRAINT(0x108001c2, 0xf),
756         INTEL_EXCLEVT_CONSTRAINT(0xd0, 0xf),    /* MEM_UOP_RETIRED.* */
757         INTEL_EXCLEVT_CONSTRAINT(0xd1, 0xf),    /* MEM_LOAD_UOPS_RETIRED.* */
758         INTEL_EXCLEVT_CONSTRAINT(0xd2, 0xf),    /* MEM_LOAD_UOPS_LLC_HIT_RETIRED.* */
759         INTEL_EXCLEVT_CONSTRAINT(0xd3, 0xf),    /* MEM_LOAD_UOPS_LLC_MISS_RETIRED.* */
760 	/* Allow all events as PEBS with no flags */
761 	INTEL_ALL_EVENT_CONSTRAINT(0, 0xf),
762 	EVENT_CONSTRAINT_END
763 };
764 
765 struct event_constraint intel_ivb_pebs_event_constraints[] = {
766         INTEL_FLAGS_UEVENT_CONSTRAINT(0x01c0, 0x2), /* INST_RETIRED.PRECDIST */
767         INTEL_PLD_CONSTRAINT(0x01cd, 0x8),    /* MEM_TRANS_RETIRED.LAT_ABOVE_THR */
768 	INTEL_PST_CONSTRAINT(0x02cd, 0x8),    /* MEM_TRANS_RETIRED.PRECISE_STORES */
769 	/* UOPS_RETIRED.ALL, inv=1, cmask=16 (cycles:p). */
770 	INTEL_FLAGS_EVENT_CONSTRAINT(0x108001c2, 0xf),
771 	/* INST_RETIRED.PREC_DIST, inv=1, cmask=16 (cycles:ppp). */
772 	INTEL_FLAGS_EVENT_CONSTRAINT(0x108001c0, 0x2),
773 	INTEL_EXCLEVT_CONSTRAINT(0xd0, 0xf),    /* MEM_UOP_RETIRED.* */
774 	INTEL_EXCLEVT_CONSTRAINT(0xd1, 0xf),    /* MEM_LOAD_UOPS_RETIRED.* */
775 	INTEL_EXCLEVT_CONSTRAINT(0xd2, 0xf),    /* MEM_LOAD_UOPS_LLC_HIT_RETIRED.* */
776 	INTEL_EXCLEVT_CONSTRAINT(0xd3, 0xf),    /* MEM_LOAD_UOPS_LLC_MISS_RETIRED.* */
777 	/* Allow all events as PEBS with no flags */
778 	INTEL_ALL_EVENT_CONSTRAINT(0, 0xf),
779         EVENT_CONSTRAINT_END
780 };
781 
782 struct event_constraint intel_hsw_pebs_event_constraints[] = {
783 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x01c0, 0x2), /* INST_RETIRED.PRECDIST */
784 	INTEL_PLD_CONSTRAINT(0x01cd, 0xf),    /* MEM_TRANS_RETIRED.* */
785 	/* UOPS_RETIRED.ALL, inv=1, cmask=16 (cycles:p). */
786 	INTEL_FLAGS_EVENT_CONSTRAINT(0x108001c2, 0xf),
787 	/* INST_RETIRED.PREC_DIST, inv=1, cmask=16 (cycles:ppp). */
788 	INTEL_FLAGS_EVENT_CONSTRAINT(0x108001c0, 0x2),
789 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_NA(0x01c2, 0xf), /* UOPS_RETIRED.ALL */
790 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_XLD(0x11d0, 0xf), /* MEM_UOPS_RETIRED.STLB_MISS_LOADS */
791 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_XLD(0x21d0, 0xf), /* MEM_UOPS_RETIRED.LOCK_LOADS */
792 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_XLD(0x41d0, 0xf), /* MEM_UOPS_RETIRED.SPLIT_LOADS */
793 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_XLD(0x81d0, 0xf), /* MEM_UOPS_RETIRED.ALL_LOADS */
794 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_XST(0x12d0, 0xf), /* MEM_UOPS_RETIRED.STLB_MISS_STORES */
795 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_XST(0x42d0, 0xf), /* MEM_UOPS_RETIRED.SPLIT_STORES */
796 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_XST(0x82d0, 0xf), /* MEM_UOPS_RETIRED.ALL_STORES */
797 	INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_XLD(0xd1, 0xf),    /* MEM_LOAD_UOPS_RETIRED.* */
798 	INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_XLD(0xd2, 0xf),    /* MEM_LOAD_UOPS_L3_HIT_RETIRED.* */
799 	INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_XLD(0xd3, 0xf),    /* MEM_LOAD_UOPS_L3_MISS_RETIRED.* */
800 	/* Allow all events as PEBS with no flags */
801 	INTEL_ALL_EVENT_CONSTRAINT(0, 0xf),
802 	EVENT_CONSTRAINT_END
803 };
804 
805 struct event_constraint intel_bdw_pebs_event_constraints[] = {
806 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x01c0, 0x2), /* INST_RETIRED.PRECDIST */
807 	INTEL_PLD_CONSTRAINT(0x01cd, 0xf),    /* MEM_TRANS_RETIRED.* */
808 	/* UOPS_RETIRED.ALL, inv=1, cmask=16 (cycles:p). */
809 	INTEL_FLAGS_EVENT_CONSTRAINT(0x108001c2, 0xf),
810 	/* INST_RETIRED.PREC_DIST, inv=1, cmask=16 (cycles:ppp). */
811 	INTEL_FLAGS_EVENT_CONSTRAINT(0x108001c0, 0x2),
812 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_NA(0x01c2, 0xf), /* UOPS_RETIRED.ALL */
813 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x11d0, 0xf), /* MEM_UOPS_RETIRED.STLB_MISS_LOADS */
814 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x21d0, 0xf), /* MEM_UOPS_RETIRED.LOCK_LOADS */
815 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x41d0, 0xf), /* MEM_UOPS_RETIRED.SPLIT_LOADS */
816 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x81d0, 0xf), /* MEM_UOPS_RETIRED.ALL_LOADS */
817 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_ST(0x12d0, 0xf), /* MEM_UOPS_RETIRED.STLB_MISS_STORES */
818 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_ST(0x42d0, 0xf), /* MEM_UOPS_RETIRED.SPLIT_STORES */
819 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_ST(0x82d0, 0xf), /* MEM_UOPS_RETIRED.ALL_STORES */
820 	INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_LD(0xd1, 0xf),    /* MEM_LOAD_UOPS_RETIRED.* */
821 	INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_LD(0xd2, 0xf),    /* MEM_LOAD_UOPS_L3_HIT_RETIRED.* */
822 	INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_LD(0xd3, 0xf),    /* MEM_LOAD_UOPS_L3_MISS_RETIRED.* */
823 	/* Allow all events as PEBS with no flags */
824 	INTEL_ALL_EVENT_CONSTRAINT(0, 0xf),
825 	EVENT_CONSTRAINT_END
826 };
827 
828 
829 struct event_constraint intel_skl_pebs_event_constraints[] = {
830 	INTEL_FLAGS_UEVENT_CONSTRAINT(0x1c0, 0x2),	/* INST_RETIRED.PREC_DIST */
831 	/* INST_RETIRED.PREC_DIST, inv=1, cmask=16 (cycles:ppp). */
832 	INTEL_FLAGS_EVENT_CONSTRAINT(0x108001c0, 0x2),
833 	/* INST_RETIRED.TOTAL_CYCLES_PS (inv=1, cmask=16) (cycles:p). */
834 	INTEL_FLAGS_EVENT_CONSTRAINT(0x108000c0, 0x0f),
835 	INTEL_PLD_CONSTRAINT(0x1cd, 0xf),		      /* MEM_TRANS_RETIRED.* */
836 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x11d0, 0xf), /* MEM_INST_RETIRED.STLB_MISS_LOADS */
837 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_ST(0x12d0, 0xf), /* MEM_INST_RETIRED.STLB_MISS_STORES */
838 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x21d0, 0xf), /* MEM_INST_RETIRED.LOCK_LOADS */
839 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_ST(0x22d0, 0xf), /* MEM_INST_RETIRED.LOCK_STORES */
840 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x41d0, 0xf), /* MEM_INST_RETIRED.SPLIT_LOADS */
841 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_ST(0x42d0, 0xf), /* MEM_INST_RETIRED.SPLIT_STORES */
842 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x81d0, 0xf), /* MEM_INST_RETIRED.ALL_LOADS */
843 	INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_ST(0x82d0, 0xf), /* MEM_INST_RETIRED.ALL_STORES */
844 	INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_LD(0xd1, 0xf),    /* MEM_LOAD_RETIRED.* */
845 	INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_LD(0xd2, 0xf),    /* MEM_LOAD_L3_HIT_RETIRED.* */
846 	INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_LD(0xd3, 0xf),    /* MEM_LOAD_L3_MISS_RETIRED.* */
847 	/* Allow all events as PEBS with no flags */
848 	INTEL_ALL_EVENT_CONSTRAINT(0, 0xf),
849 	EVENT_CONSTRAINT_END
850 };
851 
852 struct event_constraint *intel_pebs_constraints(struct perf_event *event)
853 {
854 	struct event_constraint *c;
855 
856 	if (!event->attr.precise_ip)
857 		return NULL;
858 
859 	if (x86_pmu.pebs_constraints) {
860 		for_each_event_constraint(c, x86_pmu.pebs_constraints) {
861 			if ((event->hw.config & c->cmask) == c->code) {
862 				event->hw.flags |= c->flags;
863 				return c;
864 			}
865 		}
866 	}
867 
868 	/*
869 	 * Extended PEBS support
870 	 * Makes the PEBS code search the normal constraints.
871 	 */
872 	if (x86_pmu.flags & PMU_FL_PEBS_ALL)
873 		return NULL;
874 
875 	return &emptyconstraint;
876 }
877 
878 /*
879  * We need the sched_task callback even for per-cpu events when we use
880  * the large interrupt threshold, such that we can provide PID and TID
881  * to PEBS samples.
882  */
883 static inline bool pebs_needs_sched_cb(struct cpu_hw_events *cpuc)
884 {
885 	return cpuc->n_pebs && (cpuc->n_pebs == cpuc->n_large_pebs);
886 }
887 
888 void intel_pmu_pebs_sched_task(struct perf_event_context *ctx, bool sched_in)
889 {
890 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
891 
892 	if (!sched_in && pebs_needs_sched_cb(cpuc))
893 		intel_pmu_drain_pebs_buffer();
894 }
895 
896 static inline void pebs_update_threshold(struct cpu_hw_events *cpuc)
897 {
898 	struct debug_store *ds = cpuc->ds;
899 	u64 threshold;
900 	int reserved;
901 
902 	if (x86_pmu.flags & PMU_FL_PEBS_ALL)
903 		reserved = x86_pmu.max_pebs_events + x86_pmu.num_counters_fixed;
904 	else
905 		reserved = x86_pmu.max_pebs_events;
906 
907 	if (cpuc->n_pebs == cpuc->n_large_pebs) {
908 		threshold = ds->pebs_absolute_maximum -
909 			reserved * x86_pmu.pebs_record_size;
910 	} else {
911 		threshold = ds->pebs_buffer_base + x86_pmu.pebs_record_size;
912 	}
913 
914 	ds->pebs_interrupt_threshold = threshold;
915 }
916 
917 static void
918 pebs_update_state(bool needed_cb, struct cpu_hw_events *cpuc, struct pmu *pmu)
919 {
920 	/*
921 	 * Make sure we get updated with the first PEBS
922 	 * event. It will trigger also during removal, but
923 	 * that does not hurt:
924 	 */
925 	bool update = cpuc->n_pebs == 1;
926 
927 	if (needed_cb != pebs_needs_sched_cb(cpuc)) {
928 		if (!needed_cb)
929 			perf_sched_cb_inc(pmu);
930 		else
931 			perf_sched_cb_dec(pmu);
932 
933 		update = true;
934 	}
935 
936 	if (update)
937 		pebs_update_threshold(cpuc);
938 }
939 
940 void intel_pmu_pebs_add(struct perf_event *event)
941 {
942 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
943 	struct hw_perf_event *hwc = &event->hw;
944 	bool needed_cb = pebs_needs_sched_cb(cpuc);
945 
946 	cpuc->n_pebs++;
947 	if (hwc->flags & PERF_X86_EVENT_LARGE_PEBS)
948 		cpuc->n_large_pebs++;
949 
950 	pebs_update_state(needed_cb, cpuc, event->ctx->pmu);
951 }
952 
953 void intel_pmu_pebs_enable(struct perf_event *event)
954 {
955 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
956 	struct hw_perf_event *hwc = &event->hw;
957 	struct debug_store *ds = cpuc->ds;
958 
959 	hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT;
960 
961 	cpuc->pebs_enabled |= 1ULL << hwc->idx;
962 
963 	if (event->hw.flags & PERF_X86_EVENT_PEBS_LDLAT)
964 		cpuc->pebs_enabled |= 1ULL << (hwc->idx + 32);
965 	else if (event->hw.flags & PERF_X86_EVENT_PEBS_ST)
966 		cpuc->pebs_enabled |= 1ULL << 63;
967 
968 	/*
969 	 * Use auto-reload if possible to save a MSR write in the PMI.
970 	 * This must be done in pmu::start(), because PERF_EVENT_IOC_PERIOD.
971 	 */
972 	if (hwc->flags & PERF_X86_EVENT_AUTO_RELOAD) {
973 		unsigned int idx = hwc->idx;
974 
975 		if (idx >= INTEL_PMC_IDX_FIXED)
976 			idx = MAX_PEBS_EVENTS + (idx - INTEL_PMC_IDX_FIXED);
977 		ds->pebs_event_reset[idx] =
978 			(u64)(-hwc->sample_period) & x86_pmu.cntval_mask;
979 	} else {
980 		ds->pebs_event_reset[hwc->idx] = 0;
981 	}
982 }
983 
984 void intel_pmu_pebs_del(struct perf_event *event)
985 {
986 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
987 	struct hw_perf_event *hwc = &event->hw;
988 	bool needed_cb = pebs_needs_sched_cb(cpuc);
989 
990 	cpuc->n_pebs--;
991 	if (hwc->flags & PERF_X86_EVENT_LARGE_PEBS)
992 		cpuc->n_large_pebs--;
993 
994 	pebs_update_state(needed_cb, cpuc, event->ctx->pmu);
995 }
996 
997 void intel_pmu_pebs_disable(struct perf_event *event)
998 {
999 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1000 	struct hw_perf_event *hwc = &event->hw;
1001 
1002 	if (cpuc->n_pebs == cpuc->n_large_pebs)
1003 		intel_pmu_drain_pebs_buffer();
1004 
1005 	cpuc->pebs_enabled &= ~(1ULL << hwc->idx);
1006 
1007 	if (event->hw.flags & PERF_X86_EVENT_PEBS_LDLAT)
1008 		cpuc->pebs_enabled &= ~(1ULL << (hwc->idx + 32));
1009 	else if (event->hw.flags & PERF_X86_EVENT_PEBS_ST)
1010 		cpuc->pebs_enabled &= ~(1ULL << 63);
1011 
1012 	if (cpuc->enabled)
1013 		wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled);
1014 
1015 	hwc->config |= ARCH_PERFMON_EVENTSEL_INT;
1016 }
1017 
1018 void intel_pmu_pebs_enable_all(void)
1019 {
1020 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1021 
1022 	if (cpuc->pebs_enabled)
1023 		wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled);
1024 }
1025 
1026 void intel_pmu_pebs_disable_all(void)
1027 {
1028 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1029 
1030 	if (cpuc->pebs_enabled)
1031 		wrmsrl(MSR_IA32_PEBS_ENABLE, 0);
1032 }
1033 
1034 static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
1035 {
1036 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1037 	unsigned long from = cpuc->lbr_entries[0].from;
1038 	unsigned long old_to, to = cpuc->lbr_entries[0].to;
1039 	unsigned long ip = regs->ip;
1040 	int is_64bit = 0;
1041 	void *kaddr;
1042 	int size;
1043 
1044 	/*
1045 	 * We don't need to fixup if the PEBS assist is fault like
1046 	 */
1047 	if (!x86_pmu.intel_cap.pebs_trap)
1048 		return 1;
1049 
1050 	/*
1051 	 * No LBR entry, no basic block, no rewinding
1052 	 */
1053 	if (!cpuc->lbr_stack.nr || !from || !to)
1054 		return 0;
1055 
1056 	/*
1057 	 * Basic blocks should never cross user/kernel boundaries
1058 	 */
1059 	if (kernel_ip(ip) != kernel_ip(to))
1060 		return 0;
1061 
1062 	/*
1063 	 * unsigned math, either ip is before the start (impossible) or
1064 	 * the basic block is larger than 1 page (sanity)
1065 	 */
1066 	if ((ip - to) > PEBS_FIXUP_SIZE)
1067 		return 0;
1068 
1069 	/*
1070 	 * We sampled a branch insn, rewind using the LBR stack
1071 	 */
1072 	if (ip == to) {
1073 		set_linear_ip(regs, from);
1074 		return 1;
1075 	}
1076 
1077 	size = ip - to;
1078 	if (!kernel_ip(ip)) {
1079 		int bytes;
1080 		u8 *buf = this_cpu_read(insn_buffer);
1081 
1082 		/* 'size' must fit our buffer, see above */
1083 		bytes = copy_from_user_nmi(buf, (void __user *)to, size);
1084 		if (bytes != 0)
1085 			return 0;
1086 
1087 		kaddr = buf;
1088 	} else {
1089 		kaddr = (void *)to;
1090 	}
1091 
1092 	do {
1093 		struct insn insn;
1094 
1095 		old_to = to;
1096 
1097 #ifdef CONFIG_X86_64
1098 		is_64bit = kernel_ip(to) || !test_thread_flag(TIF_IA32);
1099 #endif
1100 		insn_init(&insn, kaddr, size, is_64bit);
1101 		insn_get_length(&insn);
1102 		/*
1103 		 * Make sure there was not a problem decoding the
1104 		 * instruction and getting the length.  This is
1105 		 * doubly important because we have an infinite
1106 		 * loop if insn.length=0.
1107 		 */
1108 		if (!insn.length)
1109 			break;
1110 
1111 		to += insn.length;
1112 		kaddr += insn.length;
1113 		size -= insn.length;
1114 	} while (to < ip);
1115 
1116 	if (to == ip) {
1117 		set_linear_ip(regs, old_to);
1118 		return 1;
1119 	}
1120 
1121 	/*
1122 	 * Even though we decoded the basic block, the instruction stream
1123 	 * never matched the given IP, either the TO or the IP got corrupted.
1124 	 */
1125 	return 0;
1126 }
1127 
1128 static inline u64 intel_hsw_weight(struct pebs_record_skl *pebs)
1129 {
1130 	if (pebs->tsx_tuning) {
1131 		union hsw_tsx_tuning tsx = { .value = pebs->tsx_tuning };
1132 		return tsx.cycles_last_block;
1133 	}
1134 	return 0;
1135 }
1136 
1137 static inline u64 intel_hsw_transaction(struct pebs_record_skl *pebs)
1138 {
1139 	u64 txn = (pebs->tsx_tuning & PEBS_HSW_TSX_FLAGS) >> 32;
1140 
1141 	/* For RTM XABORTs also log the abort code from AX */
1142 	if ((txn & PERF_TXN_TRANSACTION) && (pebs->ax & 1))
1143 		txn |= ((pebs->ax >> 24) & 0xff) << PERF_TXN_ABORT_SHIFT;
1144 	return txn;
1145 }
1146 
1147 static void setup_pebs_sample_data(struct perf_event *event,
1148 				   struct pt_regs *iregs, void *__pebs,
1149 				   struct perf_sample_data *data,
1150 				   struct pt_regs *regs)
1151 {
1152 #define PERF_X86_EVENT_PEBS_HSW_PREC \
1153 		(PERF_X86_EVENT_PEBS_ST_HSW | \
1154 		 PERF_X86_EVENT_PEBS_LD_HSW | \
1155 		 PERF_X86_EVENT_PEBS_NA_HSW)
1156 	/*
1157 	 * We cast to the biggest pebs_record but are careful not to
1158 	 * unconditionally access the 'extra' entries.
1159 	 */
1160 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1161 	struct pebs_record_skl *pebs = __pebs;
1162 	u64 sample_type;
1163 	int fll, fst, dsrc;
1164 	int fl = event->hw.flags;
1165 
1166 	if (pebs == NULL)
1167 		return;
1168 
1169 	sample_type = event->attr.sample_type;
1170 	dsrc = sample_type & PERF_SAMPLE_DATA_SRC;
1171 
1172 	fll = fl & PERF_X86_EVENT_PEBS_LDLAT;
1173 	fst = fl & (PERF_X86_EVENT_PEBS_ST | PERF_X86_EVENT_PEBS_HSW_PREC);
1174 
1175 	perf_sample_data_init(data, 0, event->hw.last_period);
1176 
1177 	data->period = event->hw.last_period;
1178 
1179 	/*
1180 	 * Use latency for weight (only avail with PEBS-LL)
1181 	 */
1182 	if (fll && (sample_type & PERF_SAMPLE_WEIGHT))
1183 		data->weight = pebs->lat;
1184 
1185 	/*
1186 	 * data.data_src encodes the data source
1187 	 */
1188 	if (dsrc) {
1189 		u64 val = PERF_MEM_NA;
1190 		if (fll)
1191 			val = load_latency_data(pebs->dse);
1192 		else if (fst && (fl & PERF_X86_EVENT_PEBS_HSW_PREC))
1193 			val = precise_datala_hsw(event, pebs->dse);
1194 		else if (fst)
1195 			val = precise_store_data(pebs->dse);
1196 		data->data_src.val = val;
1197 	}
1198 
1199 	/*
1200 	 * We must however always use iregs for the unwinder to stay sane; the
1201 	 * record BP,SP,IP can point into thin air when the record is from a
1202 	 * previous PMI context or an (I)RET happened between the record and
1203 	 * PMI.
1204 	 */
1205 	if (sample_type & PERF_SAMPLE_CALLCHAIN)
1206 		data->callchain = perf_callchain(event, iregs);
1207 
1208 	/*
1209 	 * We use the interrupt regs as a base because the PEBS record does not
1210 	 * contain a full regs set, specifically it seems to lack segment
1211 	 * descriptors, which get used by things like user_mode().
1212 	 *
1213 	 * In the simple case fix up only the IP for PERF_SAMPLE_IP.
1214 	 */
1215 	*regs = *iregs;
1216 
1217 	/*
1218 	 * Initialize regs_>flags from PEBS,
1219 	 * Clear exact bit (which uses x86 EFLAGS Reserved bit 3),
1220 	 * i.e., do not rely on it being zero:
1221 	 */
1222 	regs->flags = pebs->flags & ~PERF_EFLAGS_EXACT;
1223 
1224 	if (sample_type & PERF_SAMPLE_REGS_INTR) {
1225 		regs->ax = pebs->ax;
1226 		regs->bx = pebs->bx;
1227 		regs->cx = pebs->cx;
1228 		regs->dx = pebs->dx;
1229 		regs->si = pebs->si;
1230 		regs->di = pebs->di;
1231 
1232 		regs->bp = pebs->bp;
1233 		regs->sp = pebs->sp;
1234 
1235 #ifndef CONFIG_X86_32
1236 		regs->r8 = pebs->r8;
1237 		regs->r9 = pebs->r9;
1238 		regs->r10 = pebs->r10;
1239 		regs->r11 = pebs->r11;
1240 		regs->r12 = pebs->r12;
1241 		regs->r13 = pebs->r13;
1242 		regs->r14 = pebs->r14;
1243 		regs->r15 = pebs->r15;
1244 #endif
1245 	}
1246 
1247 	if (event->attr.precise_ip > 1) {
1248 		/*
1249 		 * Haswell and later processors have an 'eventing IP'
1250 		 * (real IP) which fixes the off-by-1 skid in hardware.
1251 		 * Use it when precise_ip >= 2 :
1252 		 */
1253 		if (x86_pmu.intel_cap.pebs_format >= 2) {
1254 			set_linear_ip(regs, pebs->real_ip);
1255 			regs->flags |= PERF_EFLAGS_EXACT;
1256 		} else {
1257 			/* Otherwise, use PEBS off-by-1 IP: */
1258 			set_linear_ip(regs, pebs->ip);
1259 
1260 			/*
1261 			 * With precise_ip >= 2, try to fix up the off-by-1 IP
1262 			 * using the LBR. If successful, the fixup function
1263 			 * corrects regs->ip and calls set_linear_ip() on regs:
1264 			 */
1265 			if (intel_pmu_pebs_fixup_ip(regs))
1266 				regs->flags |= PERF_EFLAGS_EXACT;
1267 		}
1268 	} else {
1269 		/*
1270 		 * When precise_ip == 1, return the PEBS off-by-1 IP,
1271 		 * no fixup attempted:
1272 		 */
1273 		set_linear_ip(regs, pebs->ip);
1274 	}
1275 
1276 
1277 	if ((sample_type & (PERF_SAMPLE_ADDR | PERF_SAMPLE_PHYS_ADDR)) &&
1278 	    x86_pmu.intel_cap.pebs_format >= 1)
1279 		data->addr = pebs->dla;
1280 
1281 	if (x86_pmu.intel_cap.pebs_format >= 2) {
1282 		/* Only set the TSX weight when no memory weight. */
1283 		if ((sample_type & PERF_SAMPLE_WEIGHT) && !fll)
1284 			data->weight = intel_hsw_weight(pebs);
1285 
1286 		if (sample_type & PERF_SAMPLE_TRANSACTION)
1287 			data->txn = intel_hsw_transaction(pebs);
1288 	}
1289 
1290 	/*
1291 	 * v3 supplies an accurate time stamp, so we use that
1292 	 * for the time stamp.
1293 	 *
1294 	 * We can only do this for the default trace clock.
1295 	 */
1296 	if (x86_pmu.intel_cap.pebs_format >= 3 &&
1297 		event->attr.use_clockid == 0)
1298 		data->time = native_sched_clock_from_tsc(pebs->tsc);
1299 
1300 	if (has_branch_stack(event))
1301 		data->br_stack = &cpuc->lbr_stack;
1302 }
1303 
1304 static inline void *
1305 get_next_pebs_record_by_bit(void *base, void *top, int bit)
1306 {
1307 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1308 	void *at;
1309 	u64 pebs_status;
1310 
1311 	/*
1312 	 * fmt0 does not have a status bitfield (does not use
1313 	 * perf_record_nhm format)
1314 	 */
1315 	if (x86_pmu.intel_cap.pebs_format < 1)
1316 		return base;
1317 
1318 	if (base == NULL)
1319 		return NULL;
1320 
1321 	for (at = base; at < top; at += x86_pmu.pebs_record_size) {
1322 		struct pebs_record_nhm *p = at;
1323 
1324 		if (test_bit(bit, (unsigned long *)&p->status)) {
1325 			/* PEBS v3 has accurate status bits */
1326 			if (x86_pmu.intel_cap.pebs_format >= 3)
1327 				return at;
1328 
1329 			if (p->status == (1 << bit))
1330 				return at;
1331 
1332 			/* clear non-PEBS bit and re-check */
1333 			pebs_status = p->status & cpuc->pebs_enabled;
1334 			pebs_status &= PEBS_COUNTER_MASK;
1335 			if (pebs_status == (1 << bit))
1336 				return at;
1337 		}
1338 	}
1339 	return NULL;
1340 }
1341 
1342 void intel_pmu_auto_reload_read(struct perf_event *event)
1343 {
1344 	WARN_ON(!(event->hw.flags & PERF_X86_EVENT_AUTO_RELOAD));
1345 
1346 	perf_pmu_disable(event->pmu);
1347 	intel_pmu_drain_pebs_buffer();
1348 	perf_pmu_enable(event->pmu);
1349 }
1350 
1351 /*
1352  * Special variant of intel_pmu_save_and_restart() for auto-reload.
1353  */
1354 static int
1355 intel_pmu_save_and_restart_reload(struct perf_event *event, int count)
1356 {
1357 	struct hw_perf_event *hwc = &event->hw;
1358 	int shift = 64 - x86_pmu.cntval_bits;
1359 	u64 period = hwc->sample_period;
1360 	u64 prev_raw_count, new_raw_count;
1361 	s64 new, old;
1362 
1363 	WARN_ON(!period);
1364 
1365 	/*
1366 	 * drain_pebs() only happens when the PMU is disabled.
1367 	 */
1368 	WARN_ON(this_cpu_read(cpu_hw_events.enabled));
1369 
1370 	prev_raw_count = local64_read(&hwc->prev_count);
1371 	rdpmcl(hwc->event_base_rdpmc, new_raw_count);
1372 	local64_set(&hwc->prev_count, new_raw_count);
1373 
1374 	/*
1375 	 * Since the counter increments a negative counter value and
1376 	 * overflows on the sign switch, giving the interval:
1377 	 *
1378 	 *   [-period, 0]
1379 	 *
1380 	 * the difference between two consequtive reads is:
1381 	 *
1382 	 *   A) value2 - value1;
1383 	 *      when no overflows have happened in between,
1384 	 *
1385 	 *   B) (0 - value1) + (value2 - (-period));
1386 	 *      when one overflow happened in between,
1387 	 *
1388 	 *   C) (0 - value1) + (n - 1) * (period) + (value2 - (-period));
1389 	 *      when @n overflows happened in between.
1390 	 *
1391 	 * Here A) is the obvious difference, B) is the extension to the
1392 	 * discrete interval, where the first term is to the top of the
1393 	 * interval and the second term is from the bottom of the next
1394 	 * interval and C) the extension to multiple intervals, where the
1395 	 * middle term is the whole intervals covered.
1396 	 *
1397 	 * An equivalent of C, by reduction, is:
1398 	 *
1399 	 *   value2 - value1 + n * period
1400 	 */
1401 	new = ((s64)(new_raw_count << shift) >> shift);
1402 	old = ((s64)(prev_raw_count << shift) >> shift);
1403 	local64_add(new - old + count * period, &event->count);
1404 
1405 	perf_event_update_userpage(event);
1406 
1407 	return 0;
1408 }
1409 
1410 static void __intel_pmu_pebs_event(struct perf_event *event,
1411 				   struct pt_regs *iregs,
1412 				   void *base, void *top,
1413 				   int bit, int count)
1414 {
1415 	struct hw_perf_event *hwc = &event->hw;
1416 	struct perf_sample_data data;
1417 	struct pt_regs regs;
1418 	void *at = get_next_pebs_record_by_bit(base, top, bit);
1419 
1420 	if (hwc->flags & PERF_X86_EVENT_AUTO_RELOAD) {
1421 		/*
1422 		 * Now, auto-reload is only enabled in fixed period mode.
1423 		 * The reload value is always hwc->sample_period.
1424 		 * May need to change it, if auto-reload is enabled in
1425 		 * freq mode later.
1426 		 */
1427 		intel_pmu_save_and_restart_reload(event, count);
1428 	} else if (!intel_pmu_save_and_restart(event))
1429 		return;
1430 
1431 	while (count > 1) {
1432 		setup_pebs_sample_data(event, iregs, at, &data, &regs);
1433 		perf_event_output(event, &data, &regs);
1434 		at += x86_pmu.pebs_record_size;
1435 		at = get_next_pebs_record_by_bit(at, top, bit);
1436 		count--;
1437 	}
1438 
1439 	setup_pebs_sample_data(event, iregs, at, &data, &regs);
1440 
1441 	/*
1442 	 * All but the last records are processed.
1443 	 * The last one is left to be able to call the overflow handler.
1444 	 */
1445 	if (perf_event_overflow(event, &data, &regs)) {
1446 		x86_pmu_stop(event, 0);
1447 		return;
1448 	}
1449 
1450 }
1451 
1452 static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
1453 {
1454 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1455 	struct debug_store *ds = cpuc->ds;
1456 	struct perf_event *event = cpuc->events[0]; /* PMC0 only */
1457 	struct pebs_record_core *at, *top;
1458 	int n;
1459 
1460 	if (!x86_pmu.pebs_active)
1461 		return;
1462 
1463 	at  = (struct pebs_record_core *)(unsigned long)ds->pebs_buffer_base;
1464 	top = (struct pebs_record_core *)(unsigned long)ds->pebs_index;
1465 
1466 	/*
1467 	 * Whatever else happens, drain the thing
1468 	 */
1469 	ds->pebs_index = ds->pebs_buffer_base;
1470 
1471 	if (!test_bit(0, cpuc->active_mask))
1472 		return;
1473 
1474 	WARN_ON_ONCE(!event);
1475 
1476 	if (!event->attr.precise_ip)
1477 		return;
1478 
1479 	n = top - at;
1480 	if (n <= 0) {
1481 		if (event->hw.flags & PERF_X86_EVENT_AUTO_RELOAD)
1482 			intel_pmu_save_and_restart_reload(event, 0);
1483 		return;
1484 	}
1485 
1486 	__intel_pmu_pebs_event(event, iregs, at, top, 0, n);
1487 }
1488 
1489 static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
1490 {
1491 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1492 	struct debug_store *ds = cpuc->ds;
1493 	struct perf_event *event;
1494 	void *base, *at, *top;
1495 	short counts[INTEL_PMC_IDX_FIXED + MAX_FIXED_PEBS_EVENTS] = {};
1496 	short error[INTEL_PMC_IDX_FIXED + MAX_FIXED_PEBS_EVENTS] = {};
1497 	int bit, i, size;
1498 	u64 mask;
1499 
1500 	if (!x86_pmu.pebs_active)
1501 		return;
1502 
1503 	base = (struct pebs_record_nhm *)(unsigned long)ds->pebs_buffer_base;
1504 	top = (struct pebs_record_nhm *)(unsigned long)ds->pebs_index;
1505 
1506 	ds->pebs_index = ds->pebs_buffer_base;
1507 
1508 	mask = (1ULL << x86_pmu.max_pebs_events) - 1;
1509 	size = x86_pmu.max_pebs_events;
1510 	if (x86_pmu.flags & PMU_FL_PEBS_ALL) {
1511 		mask |= ((1ULL << x86_pmu.num_counters_fixed) - 1) << INTEL_PMC_IDX_FIXED;
1512 		size = INTEL_PMC_IDX_FIXED + x86_pmu.num_counters_fixed;
1513 	}
1514 
1515 	if (unlikely(base >= top)) {
1516 		/*
1517 		 * The drain_pebs() could be called twice in a short period
1518 		 * for auto-reload event in pmu::read(). There are no
1519 		 * overflows have happened in between.
1520 		 * It needs to call intel_pmu_save_and_restart_reload() to
1521 		 * update the event->count for this case.
1522 		 */
1523 		for_each_set_bit(bit, (unsigned long *)&cpuc->pebs_enabled,
1524 				 size) {
1525 			event = cpuc->events[bit];
1526 			if (event->hw.flags & PERF_X86_EVENT_AUTO_RELOAD)
1527 				intel_pmu_save_and_restart_reload(event, 0);
1528 		}
1529 		return;
1530 	}
1531 
1532 	for (at = base; at < top; at += x86_pmu.pebs_record_size) {
1533 		struct pebs_record_nhm *p = at;
1534 		u64 pebs_status;
1535 
1536 		pebs_status = p->status & cpuc->pebs_enabled;
1537 		pebs_status &= mask;
1538 
1539 		/* PEBS v3 has more accurate status bits */
1540 		if (x86_pmu.intel_cap.pebs_format >= 3) {
1541 			for_each_set_bit(bit, (unsigned long *)&pebs_status,
1542 					 size)
1543 				counts[bit]++;
1544 
1545 			continue;
1546 		}
1547 
1548 		/*
1549 		 * On some CPUs the PEBS status can be zero when PEBS is
1550 		 * racing with clearing of GLOBAL_STATUS.
1551 		 *
1552 		 * Normally we would drop that record, but in the
1553 		 * case when there is only a single active PEBS event
1554 		 * we can assume it's for that event.
1555 		 */
1556 		if (!pebs_status && cpuc->pebs_enabled &&
1557 			!(cpuc->pebs_enabled & (cpuc->pebs_enabled-1)))
1558 			pebs_status = cpuc->pebs_enabled;
1559 
1560 		bit = find_first_bit((unsigned long *)&pebs_status,
1561 					x86_pmu.max_pebs_events);
1562 		if (bit >= x86_pmu.max_pebs_events)
1563 			continue;
1564 
1565 		/*
1566 		 * The PEBS hardware does not deal well with the situation
1567 		 * when events happen near to each other and multiple bits
1568 		 * are set. But it should happen rarely.
1569 		 *
1570 		 * If these events include one PEBS and multiple non-PEBS
1571 		 * events, it doesn't impact PEBS record. The record will
1572 		 * be handled normally. (slow path)
1573 		 *
1574 		 * If these events include two or more PEBS events, the
1575 		 * records for the events can be collapsed into a single
1576 		 * one, and it's not possible to reconstruct all events
1577 		 * that caused the PEBS record. It's called collision.
1578 		 * If collision happened, the record will be dropped.
1579 		 */
1580 		if (p->status != (1ULL << bit)) {
1581 			for_each_set_bit(i, (unsigned long *)&pebs_status,
1582 					 x86_pmu.max_pebs_events)
1583 				error[i]++;
1584 			continue;
1585 		}
1586 
1587 		counts[bit]++;
1588 	}
1589 
1590 	for (bit = 0; bit < size; bit++) {
1591 		if ((counts[bit] == 0) && (error[bit] == 0))
1592 			continue;
1593 
1594 		event = cpuc->events[bit];
1595 		if (WARN_ON_ONCE(!event))
1596 			continue;
1597 
1598 		if (WARN_ON_ONCE(!event->attr.precise_ip))
1599 			continue;
1600 
1601 		/* log dropped samples number */
1602 		if (error[bit]) {
1603 			perf_log_lost_samples(event, error[bit]);
1604 
1605 			if (perf_event_account_interrupt(event))
1606 				x86_pmu_stop(event, 0);
1607 		}
1608 
1609 		if (counts[bit]) {
1610 			__intel_pmu_pebs_event(event, iregs, base,
1611 					       top, bit, counts[bit]);
1612 		}
1613 	}
1614 }
1615 
1616 /*
1617  * BTS, PEBS probe and setup
1618  */
1619 
1620 void __init intel_ds_init(void)
1621 {
1622 	/*
1623 	 * No support for 32bit formats
1624 	 */
1625 	if (!boot_cpu_has(X86_FEATURE_DTES64))
1626 		return;
1627 
1628 	x86_pmu.bts  = boot_cpu_has(X86_FEATURE_BTS);
1629 	x86_pmu.pebs = boot_cpu_has(X86_FEATURE_PEBS);
1630 	x86_pmu.pebs_buffer_size = PEBS_BUFFER_SIZE;
1631 	if (x86_pmu.version <= 4)
1632 		x86_pmu.pebs_no_isolation = 1;
1633 	if (x86_pmu.pebs) {
1634 		char pebs_type = x86_pmu.intel_cap.pebs_trap ?  '+' : '-';
1635 		int format = x86_pmu.intel_cap.pebs_format;
1636 
1637 		switch (format) {
1638 		case 0:
1639 			pr_cont("PEBS fmt0%c, ", pebs_type);
1640 			x86_pmu.pebs_record_size = sizeof(struct pebs_record_core);
1641 			/*
1642 			 * Using >PAGE_SIZE buffers makes the WRMSR to
1643 			 * PERF_GLOBAL_CTRL in intel_pmu_enable_all()
1644 			 * mysteriously hang on Core2.
1645 			 *
1646 			 * As a workaround, we don't do this.
1647 			 */
1648 			x86_pmu.pebs_buffer_size = PAGE_SIZE;
1649 			x86_pmu.drain_pebs = intel_pmu_drain_pebs_core;
1650 			break;
1651 
1652 		case 1:
1653 			pr_cont("PEBS fmt1%c, ", pebs_type);
1654 			x86_pmu.pebs_record_size = sizeof(struct pebs_record_nhm);
1655 			x86_pmu.drain_pebs = intel_pmu_drain_pebs_nhm;
1656 			break;
1657 
1658 		case 2:
1659 			pr_cont("PEBS fmt2%c, ", pebs_type);
1660 			x86_pmu.pebs_record_size = sizeof(struct pebs_record_hsw);
1661 			x86_pmu.drain_pebs = intel_pmu_drain_pebs_nhm;
1662 			break;
1663 
1664 		case 3:
1665 			pr_cont("PEBS fmt3%c, ", pebs_type);
1666 			x86_pmu.pebs_record_size =
1667 						sizeof(struct pebs_record_skl);
1668 			x86_pmu.drain_pebs = intel_pmu_drain_pebs_nhm;
1669 			x86_pmu.large_pebs_flags |= PERF_SAMPLE_TIME;
1670 			break;
1671 
1672 		default:
1673 			pr_cont("no PEBS fmt%d%c, ", format, pebs_type);
1674 			x86_pmu.pebs = 0;
1675 		}
1676 	}
1677 }
1678 
1679 void perf_restore_debug_store(void)
1680 {
1681 	struct debug_store *ds = __this_cpu_read(cpu_hw_events.ds);
1682 
1683 	if (!x86_pmu.bts && !x86_pmu.pebs)
1684 		return;
1685 
1686 	wrmsrl(MSR_IA32_DS_AREA, (unsigned long)ds);
1687 }
1688