xref: /openbmc/linux/arch/x86/events/intel/lbr.c (revision 465191d6)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/perf_event.h>
3 #include <linux/types.h>
4 
5 #include <asm/perf_event.h>
6 #include <asm/msr.h>
7 #include <asm/insn.h>
8 
9 #include "../perf_event.h"
10 
11 /*
12  * Intel LBR_SELECT bits
13  * Intel Vol3a, April 2011, Section 16.7 Table 16-10
14  *
15  * Hardware branch filter (not available on all CPUs)
16  */
17 #define LBR_KERNEL_BIT		0 /* do not capture at ring0 */
18 #define LBR_USER_BIT		1 /* do not capture at ring > 0 */
19 #define LBR_JCC_BIT		2 /* do not capture conditional branches */
20 #define LBR_REL_CALL_BIT	3 /* do not capture relative calls */
21 #define LBR_IND_CALL_BIT	4 /* do not capture indirect calls */
22 #define LBR_RETURN_BIT		5 /* do not capture near returns */
23 #define LBR_IND_JMP_BIT		6 /* do not capture indirect jumps */
24 #define LBR_REL_JMP_BIT		7 /* do not capture relative jumps */
25 #define LBR_FAR_BIT		8 /* do not capture far branches */
26 #define LBR_CALL_STACK_BIT	9 /* enable call stack */
27 
28 /*
29  * Following bit only exists in Linux; we mask it out before writing it to
30  * the actual MSR. But it helps the constraint perf code to understand
31  * that this is a separate configuration.
32  */
33 #define LBR_NO_INFO_BIT	       63 /* don't read LBR_INFO. */
34 
35 #define LBR_KERNEL	(1 << LBR_KERNEL_BIT)
36 #define LBR_USER	(1 << LBR_USER_BIT)
37 #define LBR_JCC		(1 << LBR_JCC_BIT)
38 #define LBR_REL_CALL	(1 << LBR_REL_CALL_BIT)
39 #define LBR_IND_CALL	(1 << LBR_IND_CALL_BIT)
40 #define LBR_RETURN	(1 << LBR_RETURN_BIT)
41 #define LBR_REL_JMP	(1 << LBR_REL_JMP_BIT)
42 #define LBR_IND_JMP	(1 << LBR_IND_JMP_BIT)
43 #define LBR_FAR		(1 << LBR_FAR_BIT)
44 #define LBR_CALL_STACK	(1 << LBR_CALL_STACK_BIT)
45 #define LBR_NO_INFO	(1ULL << LBR_NO_INFO_BIT)
46 
47 #define LBR_PLM (LBR_KERNEL | LBR_USER)
48 
49 #define LBR_SEL_MASK	0x3ff	/* valid bits in LBR_SELECT */
50 #define LBR_NOT_SUPP	-1	/* LBR filter not supported */
51 #define LBR_IGN		0	/* ignored */
52 
53 #define LBR_ANY		 \
54 	(LBR_JCC	|\
55 	 LBR_REL_CALL	|\
56 	 LBR_IND_CALL	|\
57 	 LBR_RETURN	|\
58 	 LBR_REL_JMP	|\
59 	 LBR_IND_JMP	|\
60 	 LBR_FAR)
61 
62 #define LBR_FROM_FLAG_MISPRED	BIT_ULL(63)
63 #define LBR_FROM_FLAG_IN_TX	BIT_ULL(62)
64 #define LBR_FROM_FLAG_ABORT	BIT_ULL(61)
65 
66 #define LBR_FROM_SIGNEXT_2MSB	(BIT_ULL(60) | BIT_ULL(59))
67 
68 /*
69  * x86control flow change classification
70  * x86control flow changes include branches, interrupts, traps, faults
71  */
72 enum {
73 	X86_BR_NONE		= 0,      /* unknown */
74 
75 	X86_BR_USER		= 1 << 0, /* branch target is user */
76 	X86_BR_KERNEL		= 1 << 1, /* branch target is kernel */
77 
78 	X86_BR_CALL		= 1 << 2, /* call */
79 	X86_BR_RET		= 1 << 3, /* return */
80 	X86_BR_SYSCALL		= 1 << 4, /* syscall */
81 	X86_BR_SYSRET		= 1 << 5, /* syscall return */
82 	X86_BR_INT		= 1 << 6, /* sw interrupt */
83 	X86_BR_IRET		= 1 << 7, /* return from interrupt */
84 	X86_BR_JCC		= 1 << 8, /* conditional */
85 	X86_BR_JMP		= 1 << 9, /* jump */
86 	X86_BR_IRQ		= 1 << 10,/* hw interrupt or trap or fault */
87 	X86_BR_IND_CALL		= 1 << 11,/* indirect calls */
88 	X86_BR_ABORT		= 1 << 12,/* transaction abort */
89 	X86_BR_IN_TX		= 1 << 13,/* in transaction */
90 	X86_BR_NO_TX		= 1 << 14,/* not in transaction */
91 	X86_BR_ZERO_CALL	= 1 << 15,/* zero length call */
92 	X86_BR_CALL_STACK	= 1 << 16,/* call stack */
93 	X86_BR_IND_JMP		= 1 << 17,/* indirect jump */
94 
95 	X86_BR_TYPE_SAVE	= 1 << 18,/* indicate to save branch type */
96 
97 };
98 
99 #define X86_BR_PLM (X86_BR_USER | X86_BR_KERNEL)
100 #define X86_BR_ANYTX (X86_BR_NO_TX | X86_BR_IN_TX)
101 
102 #define X86_BR_ANY       \
103 	(X86_BR_CALL    |\
104 	 X86_BR_RET     |\
105 	 X86_BR_SYSCALL |\
106 	 X86_BR_SYSRET  |\
107 	 X86_BR_INT     |\
108 	 X86_BR_IRET    |\
109 	 X86_BR_JCC     |\
110 	 X86_BR_JMP	 |\
111 	 X86_BR_IRQ	 |\
112 	 X86_BR_ABORT	 |\
113 	 X86_BR_IND_CALL |\
114 	 X86_BR_IND_JMP  |\
115 	 X86_BR_ZERO_CALL)
116 
117 #define X86_BR_ALL (X86_BR_PLM | X86_BR_ANY)
118 
119 #define X86_BR_ANY_CALL		 \
120 	(X86_BR_CALL		|\
121 	 X86_BR_IND_CALL	|\
122 	 X86_BR_ZERO_CALL	|\
123 	 X86_BR_SYSCALL		|\
124 	 X86_BR_IRQ		|\
125 	 X86_BR_INT)
126 
127 /*
128  * Intel LBR_CTL bits
129  *
130  * Hardware branch filter for Arch LBR
131  */
132 #define ARCH_LBR_KERNEL_BIT		1  /* capture at ring0 */
133 #define ARCH_LBR_USER_BIT		2  /* capture at ring > 0 */
134 #define ARCH_LBR_CALL_STACK_BIT		3  /* enable call stack */
135 #define ARCH_LBR_JCC_BIT		16 /* capture conditional branches */
136 #define ARCH_LBR_REL_JMP_BIT		17 /* capture relative jumps */
137 #define ARCH_LBR_IND_JMP_BIT		18 /* capture indirect jumps */
138 #define ARCH_LBR_REL_CALL_BIT		19 /* capture relative calls */
139 #define ARCH_LBR_IND_CALL_BIT		20 /* capture indirect calls */
140 #define ARCH_LBR_RETURN_BIT		21 /* capture near returns */
141 #define ARCH_LBR_OTHER_BRANCH_BIT	22 /* capture other branches */
142 
143 #define ARCH_LBR_KERNEL			(1ULL << ARCH_LBR_KERNEL_BIT)
144 #define ARCH_LBR_USER			(1ULL << ARCH_LBR_USER_BIT)
145 #define ARCH_LBR_CALL_STACK		(1ULL << ARCH_LBR_CALL_STACK_BIT)
146 #define ARCH_LBR_JCC			(1ULL << ARCH_LBR_JCC_BIT)
147 #define ARCH_LBR_REL_JMP		(1ULL << ARCH_LBR_REL_JMP_BIT)
148 #define ARCH_LBR_IND_JMP		(1ULL << ARCH_LBR_IND_JMP_BIT)
149 #define ARCH_LBR_REL_CALL		(1ULL << ARCH_LBR_REL_CALL_BIT)
150 #define ARCH_LBR_IND_CALL		(1ULL << ARCH_LBR_IND_CALL_BIT)
151 #define ARCH_LBR_RETURN			(1ULL << ARCH_LBR_RETURN_BIT)
152 #define ARCH_LBR_OTHER_BRANCH		(1ULL << ARCH_LBR_OTHER_BRANCH_BIT)
153 
154 #define ARCH_LBR_ANY			 \
155 	(ARCH_LBR_JCC			|\
156 	 ARCH_LBR_REL_JMP		|\
157 	 ARCH_LBR_IND_JMP		|\
158 	 ARCH_LBR_REL_CALL		|\
159 	 ARCH_LBR_IND_CALL		|\
160 	 ARCH_LBR_RETURN		|\
161 	 ARCH_LBR_OTHER_BRANCH)
162 
163 #define ARCH_LBR_CTL_MASK			0x7f000e
164 
165 static void intel_pmu_lbr_filter(struct cpu_hw_events *cpuc);
166 
167 static __always_inline bool is_lbr_call_stack_bit_set(u64 config)
168 {
169 	if (static_cpu_has(X86_FEATURE_ARCH_LBR))
170 		return !!(config & ARCH_LBR_CALL_STACK);
171 
172 	return !!(config & LBR_CALL_STACK);
173 }
174 
175 /*
176  * We only support LBR implementations that have FREEZE_LBRS_ON_PMI
177  * otherwise it becomes near impossible to get a reliable stack.
178  */
179 
180 static void __intel_pmu_lbr_enable(bool pmi)
181 {
182 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
183 	u64 debugctl, lbr_select = 0, orig_debugctl;
184 
185 	/*
186 	 * No need to unfreeze manually, as v4 can do that as part
187 	 * of the GLOBAL_STATUS ack.
188 	 */
189 	if (pmi && x86_pmu.version >= 4)
190 		return;
191 
192 	/*
193 	 * No need to reprogram LBR_SELECT in a PMI, as it
194 	 * did not change.
195 	 */
196 	if (cpuc->lbr_sel)
197 		lbr_select = cpuc->lbr_sel->config & x86_pmu.lbr_sel_mask;
198 	if (!static_cpu_has(X86_FEATURE_ARCH_LBR) && !pmi && cpuc->lbr_sel)
199 		wrmsrl(MSR_LBR_SELECT, lbr_select);
200 
201 	rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
202 	orig_debugctl = debugctl;
203 
204 	if (!static_cpu_has(X86_FEATURE_ARCH_LBR))
205 		debugctl |= DEBUGCTLMSR_LBR;
206 	/*
207 	 * LBR callstack does not work well with FREEZE_LBRS_ON_PMI.
208 	 * If FREEZE_LBRS_ON_PMI is set, PMI near call/return instructions
209 	 * may cause superfluous increase/decrease of LBR_TOS.
210 	 */
211 	if (is_lbr_call_stack_bit_set(lbr_select))
212 		debugctl &= ~DEBUGCTLMSR_FREEZE_LBRS_ON_PMI;
213 	else
214 		debugctl |= DEBUGCTLMSR_FREEZE_LBRS_ON_PMI;
215 
216 	if (orig_debugctl != debugctl)
217 		wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
218 
219 	if (static_cpu_has(X86_FEATURE_ARCH_LBR))
220 		wrmsrl(MSR_ARCH_LBR_CTL, lbr_select | ARCH_LBR_CTL_LBREN);
221 }
222 
223 void intel_pmu_lbr_reset_32(void)
224 {
225 	int i;
226 
227 	for (i = 0; i < x86_pmu.lbr_nr; i++)
228 		wrmsrl(x86_pmu.lbr_from + i, 0);
229 }
230 
231 void intel_pmu_lbr_reset_64(void)
232 {
233 	int i;
234 
235 	for (i = 0; i < x86_pmu.lbr_nr; i++) {
236 		wrmsrl(x86_pmu.lbr_from + i, 0);
237 		wrmsrl(x86_pmu.lbr_to   + i, 0);
238 		if (x86_pmu.lbr_has_info)
239 			wrmsrl(x86_pmu.lbr_info + i, 0);
240 	}
241 }
242 
243 static void intel_pmu_arch_lbr_reset(void)
244 {
245 	/* Write to ARCH_LBR_DEPTH MSR, all LBR entries are reset to 0 */
246 	wrmsrl(MSR_ARCH_LBR_DEPTH, x86_pmu.lbr_nr);
247 }
248 
249 void intel_pmu_lbr_reset(void)
250 {
251 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
252 
253 	if (!x86_pmu.lbr_nr)
254 		return;
255 
256 	x86_pmu.lbr_reset();
257 
258 	cpuc->last_task_ctx = NULL;
259 	cpuc->last_log_id = 0;
260 	if (!static_cpu_has(X86_FEATURE_ARCH_LBR) && cpuc->lbr_select)
261 		wrmsrl(MSR_LBR_SELECT, 0);
262 }
263 
264 /*
265  * TOS = most recently recorded branch
266  */
267 static inline u64 intel_pmu_lbr_tos(void)
268 {
269 	u64 tos;
270 
271 	rdmsrl(x86_pmu.lbr_tos, tos);
272 	return tos;
273 }
274 
275 enum {
276 	LBR_NONE,
277 	LBR_VALID,
278 };
279 
280 /*
281  * For formats with LBR_TSX flags (e.g. LBR_FORMAT_EIP_FLAGS2), bits 61:62 in
282  * MSR_LAST_BRANCH_FROM_x are the TSX flags when TSX is supported, but when
283  * TSX is not supported they have no consistent behavior:
284  *
285  *   - For wrmsr(), bits 61:62 are considered part of the sign extension.
286  *   - For HW updates (branch captures) bits 61:62 are always OFF and are not
287  *     part of the sign extension.
288  *
289  * Therefore, if:
290  *
291  *   1) LBR has TSX format
292  *   2) CPU has no TSX support enabled
293  *
294  * ... then any value passed to wrmsr() must be sign extended to 63 bits and any
295  * value from rdmsr() must be converted to have a 61 bits sign extension,
296  * ignoring the TSX flags.
297  */
298 static inline bool lbr_from_signext_quirk_needed(void)
299 {
300 	bool tsx_support = boot_cpu_has(X86_FEATURE_HLE) ||
301 			   boot_cpu_has(X86_FEATURE_RTM);
302 
303 	return !tsx_support && x86_pmu.lbr_has_tsx;
304 }
305 
306 static DEFINE_STATIC_KEY_FALSE(lbr_from_quirk_key);
307 
308 /* If quirk is enabled, ensure sign extension is 63 bits: */
309 inline u64 lbr_from_signext_quirk_wr(u64 val)
310 {
311 	if (static_branch_unlikely(&lbr_from_quirk_key)) {
312 		/*
313 		 * Sign extend into bits 61:62 while preserving bit 63.
314 		 *
315 		 * Quirk is enabled when TSX is disabled. Therefore TSX bits
316 		 * in val are always OFF and must be changed to be sign
317 		 * extension bits. Since bits 59:60 are guaranteed to be
318 		 * part of the sign extension bits, we can just copy them
319 		 * to 61:62.
320 		 */
321 		val |= (LBR_FROM_SIGNEXT_2MSB & val) << 2;
322 	}
323 	return val;
324 }
325 
326 /*
327  * If quirk is needed, ensure sign extension is 61 bits:
328  */
329 static u64 lbr_from_signext_quirk_rd(u64 val)
330 {
331 	if (static_branch_unlikely(&lbr_from_quirk_key)) {
332 		/*
333 		 * Quirk is on when TSX is not enabled. Therefore TSX
334 		 * flags must be read as OFF.
335 		 */
336 		val &= ~(LBR_FROM_FLAG_IN_TX | LBR_FROM_FLAG_ABORT);
337 	}
338 	return val;
339 }
340 
341 static __always_inline void wrlbr_from(unsigned int idx, u64 val)
342 {
343 	val = lbr_from_signext_quirk_wr(val);
344 	wrmsrl(x86_pmu.lbr_from + idx, val);
345 }
346 
347 static __always_inline void wrlbr_to(unsigned int idx, u64 val)
348 {
349 	wrmsrl(x86_pmu.lbr_to + idx, val);
350 }
351 
352 static __always_inline void wrlbr_info(unsigned int idx, u64 val)
353 {
354 	wrmsrl(x86_pmu.lbr_info + idx, val);
355 }
356 
357 static __always_inline u64 rdlbr_from(unsigned int idx, struct lbr_entry *lbr)
358 {
359 	u64 val;
360 
361 	if (lbr)
362 		return lbr->from;
363 
364 	rdmsrl(x86_pmu.lbr_from + idx, val);
365 
366 	return lbr_from_signext_quirk_rd(val);
367 }
368 
369 static __always_inline u64 rdlbr_to(unsigned int idx, struct lbr_entry *lbr)
370 {
371 	u64 val;
372 
373 	if (lbr)
374 		return lbr->to;
375 
376 	rdmsrl(x86_pmu.lbr_to + idx, val);
377 
378 	return val;
379 }
380 
381 static __always_inline u64 rdlbr_info(unsigned int idx, struct lbr_entry *lbr)
382 {
383 	u64 val;
384 
385 	if (lbr)
386 		return lbr->info;
387 
388 	rdmsrl(x86_pmu.lbr_info + idx, val);
389 
390 	return val;
391 }
392 
393 static inline void
394 wrlbr_all(struct lbr_entry *lbr, unsigned int idx, bool need_info)
395 {
396 	wrlbr_from(idx, lbr->from);
397 	wrlbr_to(idx, lbr->to);
398 	if (need_info)
399 		wrlbr_info(idx, lbr->info);
400 }
401 
402 static inline bool
403 rdlbr_all(struct lbr_entry *lbr, unsigned int idx, bool need_info)
404 {
405 	u64 from = rdlbr_from(idx, NULL);
406 
407 	/* Don't read invalid entry */
408 	if (!from)
409 		return false;
410 
411 	lbr->from = from;
412 	lbr->to = rdlbr_to(idx, NULL);
413 	if (need_info)
414 		lbr->info = rdlbr_info(idx, NULL);
415 
416 	return true;
417 }
418 
419 void intel_pmu_lbr_restore(void *ctx)
420 {
421 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
422 	struct x86_perf_task_context *task_ctx = ctx;
423 	bool need_info = x86_pmu.lbr_has_info;
424 	u64 tos = task_ctx->tos;
425 	unsigned lbr_idx, mask;
426 	int i;
427 
428 	mask = x86_pmu.lbr_nr - 1;
429 	for (i = 0; i < task_ctx->valid_lbrs; i++) {
430 		lbr_idx = (tos - i) & mask;
431 		wrlbr_all(&task_ctx->lbr[i], lbr_idx, need_info);
432 	}
433 
434 	for (; i < x86_pmu.lbr_nr; i++) {
435 		lbr_idx = (tos - i) & mask;
436 		wrlbr_from(lbr_idx, 0);
437 		wrlbr_to(lbr_idx, 0);
438 		if (need_info)
439 			wrlbr_info(lbr_idx, 0);
440 	}
441 
442 	wrmsrl(x86_pmu.lbr_tos, tos);
443 
444 	if (cpuc->lbr_select)
445 		wrmsrl(MSR_LBR_SELECT, task_ctx->lbr_sel);
446 }
447 
448 static void intel_pmu_arch_lbr_restore(void *ctx)
449 {
450 	struct x86_perf_task_context_arch_lbr *task_ctx = ctx;
451 	struct lbr_entry *entries = task_ctx->entries;
452 	int i;
453 
454 	/* Fast reset the LBRs before restore if the call stack is not full. */
455 	if (!entries[x86_pmu.lbr_nr - 1].from)
456 		intel_pmu_arch_lbr_reset();
457 
458 	for (i = 0; i < x86_pmu.lbr_nr; i++) {
459 		if (!entries[i].from)
460 			break;
461 		wrlbr_all(&entries[i], i, true);
462 	}
463 }
464 
465 /*
466  * Restore the Architecture LBR state from the xsave area in the perf
467  * context data for the task via the XRSTORS instruction.
468  */
469 static void intel_pmu_arch_lbr_xrstors(void *ctx)
470 {
471 	struct x86_perf_task_context_arch_lbr_xsave *task_ctx = ctx;
472 
473 	xrstors(&task_ctx->xsave, XFEATURE_MASK_LBR);
474 }
475 
476 static __always_inline bool lbr_is_reset_in_cstate(void *ctx)
477 {
478 	if (static_cpu_has(X86_FEATURE_ARCH_LBR))
479 		return x86_pmu.lbr_deep_c_reset && !rdlbr_from(0, NULL);
480 
481 	return !rdlbr_from(((struct x86_perf_task_context *)ctx)->tos, NULL);
482 }
483 
484 static void __intel_pmu_lbr_restore(void *ctx)
485 {
486 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
487 
488 	if (task_context_opt(ctx)->lbr_callstack_users == 0 ||
489 	    task_context_opt(ctx)->lbr_stack_state == LBR_NONE) {
490 		intel_pmu_lbr_reset();
491 		return;
492 	}
493 
494 	/*
495 	 * Does not restore the LBR registers, if
496 	 * - No one else touched them, and
497 	 * - Was not cleared in Cstate
498 	 */
499 	if ((ctx == cpuc->last_task_ctx) &&
500 	    (task_context_opt(ctx)->log_id == cpuc->last_log_id) &&
501 	    !lbr_is_reset_in_cstate(ctx)) {
502 		task_context_opt(ctx)->lbr_stack_state = LBR_NONE;
503 		return;
504 	}
505 
506 	x86_pmu.lbr_restore(ctx);
507 
508 	task_context_opt(ctx)->lbr_stack_state = LBR_NONE;
509 }
510 
511 void intel_pmu_lbr_save(void *ctx)
512 {
513 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
514 	struct x86_perf_task_context *task_ctx = ctx;
515 	bool need_info = x86_pmu.lbr_has_info;
516 	unsigned lbr_idx, mask;
517 	u64 tos;
518 	int i;
519 
520 	mask = x86_pmu.lbr_nr - 1;
521 	tos = intel_pmu_lbr_tos();
522 	for (i = 0; i < x86_pmu.lbr_nr; i++) {
523 		lbr_idx = (tos - i) & mask;
524 		if (!rdlbr_all(&task_ctx->lbr[i], lbr_idx, need_info))
525 			break;
526 	}
527 	task_ctx->valid_lbrs = i;
528 	task_ctx->tos = tos;
529 
530 	if (cpuc->lbr_select)
531 		rdmsrl(MSR_LBR_SELECT, task_ctx->lbr_sel);
532 }
533 
534 static void intel_pmu_arch_lbr_save(void *ctx)
535 {
536 	struct x86_perf_task_context_arch_lbr *task_ctx = ctx;
537 	struct lbr_entry *entries = task_ctx->entries;
538 	int i;
539 
540 	for (i = 0; i < x86_pmu.lbr_nr; i++) {
541 		if (!rdlbr_all(&entries[i], i, true))
542 			break;
543 	}
544 
545 	/* LBR call stack is not full. Reset is required in restore. */
546 	if (i < x86_pmu.lbr_nr)
547 		entries[x86_pmu.lbr_nr - 1].from = 0;
548 }
549 
550 /*
551  * Save the Architecture LBR state to the xsave area in the perf
552  * context data for the task via the XSAVES instruction.
553  */
554 static void intel_pmu_arch_lbr_xsaves(void *ctx)
555 {
556 	struct x86_perf_task_context_arch_lbr_xsave *task_ctx = ctx;
557 
558 	xsaves(&task_ctx->xsave, XFEATURE_MASK_LBR);
559 }
560 
561 static void __intel_pmu_lbr_save(void *ctx)
562 {
563 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
564 
565 	if (task_context_opt(ctx)->lbr_callstack_users == 0) {
566 		task_context_opt(ctx)->lbr_stack_state = LBR_NONE;
567 		return;
568 	}
569 
570 	x86_pmu.lbr_save(ctx);
571 
572 	task_context_opt(ctx)->lbr_stack_state = LBR_VALID;
573 
574 	cpuc->last_task_ctx = ctx;
575 	cpuc->last_log_id = ++task_context_opt(ctx)->log_id;
576 }
577 
578 void intel_pmu_lbr_swap_task_ctx(struct perf_event_context *prev,
579 				 struct perf_event_context *next)
580 {
581 	void *prev_ctx_data, *next_ctx_data;
582 
583 	swap(prev->task_ctx_data, next->task_ctx_data);
584 
585 	/*
586 	 * Architecture specific synchronization makes sense in
587 	 * case both prev->task_ctx_data and next->task_ctx_data
588 	 * pointers are allocated.
589 	 */
590 
591 	prev_ctx_data = next->task_ctx_data;
592 	next_ctx_data = prev->task_ctx_data;
593 
594 	if (!prev_ctx_data || !next_ctx_data)
595 		return;
596 
597 	swap(task_context_opt(prev_ctx_data)->lbr_callstack_users,
598 	     task_context_opt(next_ctx_data)->lbr_callstack_users);
599 }
600 
601 void intel_pmu_lbr_sched_task(struct perf_event_context *ctx, bool sched_in)
602 {
603 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
604 	void *task_ctx;
605 
606 	if (!cpuc->lbr_users)
607 		return;
608 
609 	/*
610 	 * If LBR callstack feature is enabled and the stack was saved when
611 	 * the task was scheduled out, restore the stack. Otherwise flush
612 	 * the LBR stack.
613 	 */
614 	task_ctx = ctx ? ctx->task_ctx_data : NULL;
615 	if (task_ctx) {
616 		if (sched_in)
617 			__intel_pmu_lbr_restore(task_ctx);
618 		else
619 			__intel_pmu_lbr_save(task_ctx);
620 		return;
621 	}
622 
623 	/*
624 	 * Since a context switch can flip the address space and LBR entries
625 	 * are not tagged with an identifier, we need to wipe the LBR, even for
626 	 * per-cpu events. You simply cannot resolve the branches from the old
627 	 * address space.
628 	 */
629 	if (sched_in)
630 		intel_pmu_lbr_reset();
631 }
632 
633 static inline bool branch_user_callstack(unsigned br_sel)
634 {
635 	return (br_sel & X86_BR_USER) && (br_sel & X86_BR_CALL_STACK);
636 }
637 
638 void intel_pmu_lbr_add(struct perf_event *event)
639 {
640 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
641 
642 	if (!x86_pmu.lbr_nr)
643 		return;
644 
645 	if (event->hw.flags & PERF_X86_EVENT_LBR_SELECT)
646 		cpuc->lbr_select = 1;
647 
648 	cpuc->br_sel = event->hw.branch_reg.reg;
649 
650 	if (branch_user_callstack(cpuc->br_sel) && event->ctx->task_ctx_data)
651 		task_context_opt(event->ctx->task_ctx_data)->lbr_callstack_users++;
652 
653 	/*
654 	 * Request pmu::sched_task() callback, which will fire inside the
655 	 * regular perf event scheduling, so that call will:
656 	 *
657 	 *  - restore or wipe; when LBR-callstack,
658 	 *  - wipe; otherwise,
659 	 *
660 	 * when this is from __perf_event_task_sched_in().
661 	 *
662 	 * However, if this is from perf_install_in_context(), no such callback
663 	 * will follow and we'll need to reset the LBR here if this is the
664 	 * first LBR event.
665 	 *
666 	 * The problem is, we cannot tell these cases apart... but we can
667 	 * exclude the biggest chunk of cases by looking at
668 	 * event->total_time_running. An event that has accrued runtime cannot
669 	 * be 'new'. Conversely, a new event can get installed through the
670 	 * context switch path for the first time.
671 	 */
672 	if (x86_pmu.intel_cap.pebs_baseline && event->attr.precise_ip > 0)
673 		cpuc->lbr_pebs_users++;
674 	perf_sched_cb_inc(event->ctx->pmu);
675 	if (!cpuc->lbr_users++ && !event->total_time_running)
676 		intel_pmu_lbr_reset();
677 }
678 
679 void release_lbr_buffers(void)
680 {
681 	struct kmem_cache *kmem_cache;
682 	struct cpu_hw_events *cpuc;
683 	int cpu;
684 
685 	if (!static_cpu_has(X86_FEATURE_ARCH_LBR))
686 		return;
687 
688 	for_each_possible_cpu(cpu) {
689 		cpuc = per_cpu_ptr(&cpu_hw_events, cpu);
690 		kmem_cache = x86_get_pmu(cpu)->task_ctx_cache;
691 		if (kmem_cache && cpuc->lbr_xsave) {
692 			kmem_cache_free(kmem_cache, cpuc->lbr_xsave);
693 			cpuc->lbr_xsave = NULL;
694 		}
695 	}
696 }
697 
698 void reserve_lbr_buffers(void)
699 {
700 	struct kmem_cache *kmem_cache;
701 	struct cpu_hw_events *cpuc;
702 	int cpu;
703 
704 	if (!static_cpu_has(X86_FEATURE_ARCH_LBR))
705 		return;
706 
707 	for_each_possible_cpu(cpu) {
708 		cpuc = per_cpu_ptr(&cpu_hw_events, cpu);
709 		kmem_cache = x86_get_pmu(cpu)->task_ctx_cache;
710 		if (!kmem_cache || cpuc->lbr_xsave)
711 			continue;
712 
713 		cpuc->lbr_xsave = kmem_cache_alloc_node(kmem_cache,
714 							GFP_KERNEL | __GFP_ZERO,
715 							cpu_to_node(cpu));
716 	}
717 }
718 
719 void intel_pmu_lbr_del(struct perf_event *event)
720 {
721 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
722 
723 	if (!x86_pmu.lbr_nr)
724 		return;
725 
726 	if (branch_user_callstack(cpuc->br_sel) &&
727 	    event->ctx->task_ctx_data)
728 		task_context_opt(event->ctx->task_ctx_data)->lbr_callstack_users--;
729 
730 	if (event->hw.flags & PERF_X86_EVENT_LBR_SELECT)
731 		cpuc->lbr_select = 0;
732 
733 	if (x86_pmu.intel_cap.pebs_baseline && event->attr.precise_ip > 0)
734 		cpuc->lbr_pebs_users--;
735 	cpuc->lbr_users--;
736 	WARN_ON_ONCE(cpuc->lbr_users < 0);
737 	WARN_ON_ONCE(cpuc->lbr_pebs_users < 0);
738 	perf_sched_cb_dec(event->ctx->pmu);
739 }
740 
741 static inline bool vlbr_exclude_host(void)
742 {
743 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
744 
745 	return test_bit(INTEL_PMC_IDX_FIXED_VLBR,
746 		(unsigned long *)&cpuc->intel_ctrl_guest_mask);
747 }
748 
749 void intel_pmu_lbr_enable_all(bool pmi)
750 {
751 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
752 
753 	if (cpuc->lbr_users && !vlbr_exclude_host())
754 		__intel_pmu_lbr_enable(pmi);
755 }
756 
757 void intel_pmu_lbr_disable_all(void)
758 {
759 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
760 
761 	if (cpuc->lbr_users && !vlbr_exclude_host()) {
762 		if (static_cpu_has(X86_FEATURE_ARCH_LBR))
763 			return __intel_pmu_arch_lbr_disable();
764 
765 		__intel_pmu_lbr_disable();
766 	}
767 }
768 
769 void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc)
770 {
771 	unsigned long mask = x86_pmu.lbr_nr - 1;
772 	struct perf_branch_entry *br = cpuc->lbr_entries;
773 	u64 tos = intel_pmu_lbr_tos();
774 	int i;
775 
776 	for (i = 0; i < x86_pmu.lbr_nr; i++) {
777 		unsigned long lbr_idx = (tos - i) & mask;
778 		union {
779 			struct {
780 				u32 from;
781 				u32 to;
782 			};
783 			u64     lbr;
784 		} msr_lastbranch;
785 
786 		rdmsrl(x86_pmu.lbr_from + lbr_idx, msr_lastbranch.lbr);
787 
788 		perf_clear_branch_entry_bitfields(br);
789 
790 		br->from	= msr_lastbranch.from;
791 		br->to		= msr_lastbranch.to;
792 		br++;
793 	}
794 	cpuc->lbr_stack.nr = i;
795 	cpuc->lbr_stack.hw_idx = tos;
796 }
797 
798 /*
799  * Due to lack of segmentation in Linux the effective address (offset)
800  * is the same as the linear address, allowing us to merge the LIP and EIP
801  * LBR formats.
802  */
803 void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc)
804 {
805 	bool need_info = false, call_stack = false;
806 	unsigned long mask = x86_pmu.lbr_nr - 1;
807 	struct perf_branch_entry *br = cpuc->lbr_entries;
808 	u64 tos = intel_pmu_lbr_tos();
809 	int i;
810 	int out = 0;
811 	int num = x86_pmu.lbr_nr;
812 
813 	if (cpuc->lbr_sel) {
814 		need_info = !(cpuc->lbr_sel->config & LBR_NO_INFO);
815 		if (cpuc->lbr_sel->config & LBR_CALL_STACK)
816 			call_stack = true;
817 	}
818 
819 	for (i = 0; i < num; i++) {
820 		unsigned long lbr_idx = (tos - i) & mask;
821 		u64 from, to, mis = 0, pred = 0, in_tx = 0, abort = 0;
822 		u16 cycles = 0;
823 
824 		from = rdlbr_from(lbr_idx, NULL);
825 		to   = rdlbr_to(lbr_idx, NULL);
826 
827 		/*
828 		 * Read LBR call stack entries
829 		 * until invalid entry (0s) is detected.
830 		 */
831 		if (call_stack && !from)
832 			break;
833 
834 		if (x86_pmu.lbr_has_info) {
835 			if (need_info) {
836 				u64 info;
837 
838 				info = rdlbr_info(lbr_idx, NULL);
839 				mis = !!(info & LBR_INFO_MISPRED);
840 				pred = !mis;
841 				cycles = (info & LBR_INFO_CYCLES);
842 				if (x86_pmu.lbr_has_tsx) {
843 					in_tx = !!(info & LBR_INFO_IN_TX);
844 					abort = !!(info & LBR_INFO_ABORT);
845 				}
846 			}
847 		} else {
848 			int skip = 0;
849 
850 			if (x86_pmu.lbr_from_flags) {
851 				mis = !!(from & LBR_FROM_FLAG_MISPRED);
852 				pred = !mis;
853 				skip = 1;
854 			}
855 			if (x86_pmu.lbr_has_tsx) {
856 				in_tx = !!(from & LBR_FROM_FLAG_IN_TX);
857 				abort = !!(from & LBR_FROM_FLAG_ABORT);
858 				skip = 3;
859 			}
860 			from = (u64)((((s64)from) << skip) >> skip);
861 
862 			if (x86_pmu.lbr_to_cycles) {
863 				cycles = ((to >> 48) & LBR_INFO_CYCLES);
864 				to = (u64)((((s64)to) << 16) >> 16);
865 			}
866 		}
867 
868 		/*
869 		 * Some CPUs report duplicated abort records,
870 		 * with the second entry not having an abort bit set.
871 		 * Skip them here. This loop runs backwards,
872 		 * so we need to undo the previous record.
873 		 * If the abort just happened outside the window
874 		 * the extra entry cannot be removed.
875 		 */
876 		if (abort && x86_pmu.lbr_double_abort && out > 0)
877 			out--;
878 
879 		perf_clear_branch_entry_bitfields(br+out);
880 		br[out].from	 = from;
881 		br[out].to	 = to;
882 		br[out].mispred	 = mis;
883 		br[out].predicted = pred;
884 		br[out].in_tx	 = in_tx;
885 		br[out].abort	 = abort;
886 		br[out].cycles	 = cycles;
887 		out++;
888 	}
889 	cpuc->lbr_stack.nr = out;
890 	cpuc->lbr_stack.hw_idx = tos;
891 }
892 
893 static DEFINE_STATIC_KEY_FALSE(x86_lbr_mispred);
894 static DEFINE_STATIC_KEY_FALSE(x86_lbr_cycles);
895 static DEFINE_STATIC_KEY_FALSE(x86_lbr_type);
896 
897 static __always_inline int get_lbr_br_type(u64 info)
898 {
899 	int type = 0;
900 
901 	if (static_branch_likely(&x86_lbr_type))
902 		type = (info & LBR_INFO_BR_TYPE) >> LBR_INFO_BR_TYPE_OFFSET;
903 
904 	return type;
905 }
906 
907 static __always_inline bool get_lbr_mispred(u64 info)
908 {
909 	bool mispred = 0;
910 
911 	if (static_branch_likely(&x86_lbr_mispred))
912 		mispred = !!(info & LBR_INFO_MISPRED);
913 
914 	return mispred;
915 }
916 
917 static __always_inline u16 get_lbr_cycles(u64 info)
918 {
919 	u16 cycles = info & LBR_INFO_CYCLES;
920 
921 	if (static_cpu_has(X86_FEATURE_ARCH_LBR) &&
922 	    (!static_branch_likely(&x86_lbr_cycles) ||
923 	     !(info & LBR_INFO_CYC_CNT_VALID)))
924 		cycles = 0;
925 
926 	return cycles;
927 }
928 
929 static void intel_pmu_store_lbr(struct cpu_hw_events *cpuc,
930 				struct lbr_entry *entries)
931 {
932 	struct perf_branch_entry *e;
933 	struct lbr_entry *lbr;
934 	u64 from, to, info;
935 	int i;
936 
937 	for (i = 0; i < x86_pmu.lbr_nr; i++) {
938 		lbr = entries ? &entries[i] : NULL;
939 		e = &cpuc->lbr_entries[i];
940 
941 		from = rdlbr_from(i, lbr);
942 		/*
943 		 * Read LBR entries until invalid entry (0s) is detected.
944 		 */
945 		if (!from)
946 			break;
947 
948 		to = rdlbr_to(i, lbr);
949 		info = rdlbr_info(i, lbr);
950 
951 		perf_clear_branch_entry_bitfields(e);
952 
953 		e->from		= from;
954 		e->to		= to;
955 		e->mispred	= get_lbr_mispred(info);
956 		e->predicted	= !e->mispred;
957 		e->in_tx	= !!(info & LBR_INFO_IN_TX);
958 		e->abort	= !!(info & LBR_INFO_ABORT);
959 		e->cycles	= get_lbr_cycles(info);
960 		e->type		= get_lbr_br_type(info);
961 	}
962 
963 	cpuc->lbr_stack.nr = i;
964 }
965 
966 static void intel_pmu_arch_lbr_read(struct cpu_hw_events *cpuc)
967 {
968 	intel_pmu_store_lbr(cpuc, NULL);
969 }
970 
971 static void intel_pmu_arch_lbr_read_xsave(struct cpu_hw_events *cpuc)
972 {
973 	struct x86_perf_task_context_arch_lbr_xsave *xsave = cpuc->lbr_xsave;
974 
975 	if (!xsave) {
976 		intel_pmu_store_lbr(cpuc, NULL);
977 		return;
978 	}
979 	xsaves(&xsave->xsave, XFEATURE_MASK_LBR);
980 
981 	intel_pmu_store_lbr(cpuc, xsave->lbr.entries);
982 }
983 
984 void intel_pmu_lbr_read(void)
985 {
986 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
987 
988 	/*
989 	 * Don't read when all LBRs users are using adaptive PEBS.
990 	 *
991 	 * This could be smarter and actually check the event,
992 	 * but this simple approach seems to work for now.
993 	 */
994 	if (!cpuc->lbr_users || vlbr_exclude_host() ||
995 	    cpuc->lbr_users == cpuc->lbr_pebs_users)
996 		return;
997 
998 	x86_pmu.lbr_read(cpuc);
999 
1000 	intel_pmu_lbr_filter(cpuc);
1001 }
1002 
1003 /*
1004  * SW filter is used:
1005  * - in case there is no HW filter
1006  * - in case the HW filter has errata or limitations
1007  */
1008 static int intel_pmu_setup_sw_lbr_filter(struct perf_event *event)
1009 {
1010 	u64 br_type = event->attr.branch_sample_type;
1011 	int mask = 0;
1012 
1013 	if (br_type & PERF_SAMPLE_BRANCH_USER)
1014 		mask |= X86_BR_USER;
1015 
1016 	if (br_type & PERF_SAMPLE_BRANCH_KERNEL)
1017 		mask |= X86_BR_KERNEL;
1018 
1019 	/* we ignore BRANCH_HV here */
1020 
1021 	if (br_type & PERF_SAMPLE_BRANCH_ANY)
1022 		mask |= X86_BR_ANY;
1023 
1024 	if (br_type & PERF_SAMPLE_BRANCH_ANY_CALL)
1025 		mask |= X86_BR_ANY_CALL;
1026 
1027 	if (br_type & PERF_SAMPLE_BRANCH_ANY_RETURN)
1028 		mask |= X86_BR_RET | X86_BR_IRET | X86_BR_SYSRET;
1029 
1030 	if (br_type & PERF_SAMPLE_BRANCH_IND_CALL)
1031 		mask |= X86_BR_IND_CALL;
1032 
1033 	if (br_type & PERF_SAMPLE_BRANCH_ABORT_TX)
1034 		mask |= X86_BR_ABORT;
1035 
1036 	if (br_type & PERF_SAMPLE_BRANCH_IN_TX)
1037 		mask |= X86_BR_IN_TX;
1038 
1039 	if (br_type & PERF_SAMPLE_BRANCH_NO_TX)
1040 		mask |= X86_BR_NO_TX;
1041 
1042 	if (br_type & PERF_SAMPLE_BRANCH_COND)
1043 		mask |= X86_BR_JCC;
1044 
1045 	if (br_type & PERF_SAMPLE_BRANCH_CALL_STACK) {
1046 		if (!x86_pmu_has_lbr_callstack())
1047 			return -EOPNOTSUPP;
1048 		if (mask & ~(X86_BR_USER | X86_BR_KERNEL))
1049 			return -EINVAL;
1050 		mask |= X86_BR_CALL | X86_BR_IND_CALL | X86_BR_RET |
1051 			X86_BR_CALL_STACK;
1052 	}
1053 
1054 	if (br_type & PERF_SAMPLE_BRANCH_IND_JUMP)
1055 		mask |= X86_BR_IND_JMP;
1056 
1057 	if (br_type & PERF_SAMPLE_BRANCH_CALL)
1058 		mask |= X86_BR_CALL | X86_BR_ZERO_CALL;
1059 
1060 	if (br_type & PERF_SAMPLE_BRANCH_TYPE_SAVE)
1061 		mask |= X86_BR_TYPE_SAVE;
1062 
1063 	/*
1064 	 * stash actual user request into reg, it may
1065 	 * be used by fixup code for some CPU
1066 	 */
1067 	event->hw.branch_reg.reg = mask;
1068 	return 0;
1069 }
1070 
1071 /*
1072  * setup the HW LBR filter
1073  * Used only when available, may not be enough to disambiguate
1074  * all branches, may need the help of the SW filter
1075  */
1076 static int intel_pmu_setup_hw_lbr_filter(struct perf_event *event)
1077 {
1078 	struct hw_perf_event_extra *reg;
1079 	u64 br_type = event->attr.branch_sample_type;
1080 	u64 mask = 0, v;
1081 	int i;
1082 
1083 	for (i = 0; i < PERF_SAMPLE_BRANCH_MAX_SHIFT; i++) {
1084 		if (!(br_type & (1ULL << i)))
1085 			continue;
1086 
1087 		v = x86_pmu.lbr_sel_map[i];
1088 		if (v == LBR_NOT_SUPP)
1089 			return -EOPNOTSUPP;
1090 
1091 		if (v != LBR_IGN)
1092 			mask |= v;
1093 	}
1094 
1095 	reg = &event->hw.branch_reg;
1096 	reg->idx = EXTRA_REG_LBR;
1097 
1098 	if (static_cpu_has(X86_FEATURE_ARCH_LBR)) {
1099 		reg->config = mask;
1100 		return 0;
1101 	}
1102 
1103 	/*
1104 	 * The first 9 bits (LBR_SEL_MASK) in LBR_SELECT operate
1105 	 * in suppress mode. So LBR_SELECT should be set to
1106 	 * (~mask & LBR_SEL_MASK) | (mask & ~LBR_SEL_MASK)
1107 	 * But the 10th bit LBR_CALL_STACK does not operate
1108 	 * in suppress mode.
1109 	 */
1110 	reg->config = mask ^ (x86_pmu.lbr_sel_mask & ~LBR_CALL_STACK);
1111 
1112 	if ((br_type & PERF_SAMPLE_BRANCH_NO_CYCLES) &&
1113 	    (br_type & PERF_SAMPLE_BRANCH_NO_FLAGS) &&
1114 	    x86_pmu.lbr_has_info)
1115 		reg->config |= LBR_NO_INFO;
1116 
1117 	return 0;
1118 }
1119 
1120 int intel_pmu_setup_lbr_filter(struct perf_event *event)
1121 {
1122 	int ret = 0;
1123 
1124 	/*
1125 	 * no LBR on this PMU
1126 	 */
1127 	if (!x86_pmu.lbr_nr)
1128 		return -EOPNOTSUPP;
1129 
1130 	/*
1131 	 * setup SW LBR filter
1132 	 */
1133 	ret = intel_pmu_setup_sw_lbr_filter(event);
1134 	if (ret)
1135 		return ret;
1136 
1137 	/*
1138 	 * setup HW LBR filter, if any
1139 	 */
1140 	if (x86_pmu.lbr_sel_map)
1141 		ret = intel_pmu_setup_hw_lbr_filter(event);
1142 
1143 	return ret;
1144 }
1145 
1146 /*
1147  * return the type of control flow change at address "from"
1148  * instruction is not necessarily a branch (in case of interrupt).
1149  *
1150  * The branch type returned also includes the priv level of the
1151  * target of the control flow change (X86_BR_USER, X86_BR_KERNEL).
1152  *
1153  * If a branch type is unknown OR the instruction cannot be
1154  * decoded (e.g., text page not present), then X86_BR_NONE is
1155  * returned.
1156  */
1157 static int branch_type(unsigned long from, unsigned long to, int abort)
1158 {
1159 	struct insn insn;
1160 	void *addr;
1161 	int bytes_read, bytes_left;
1162 	int ret = X86_BR_NONE;
1163 	int ext, to_plm, from_plm;
1164 	u8 buf[MAX_INSN_SIZE];
1165 	int is64 = 0;
1166 
1167 	to_plm = kernel_ip(to) ? X86_BR_KERNEL : X86_BR_USER;
1168 	from_plm = kernel_ip(from) ? X86_BR_KERNEL : X86_BR_USER;
1169 
1170 	/*
1171 	 * maybe zero if lbr did not fill up after a reset by the time
1172 	 * we get a PMU interrupt
1173 	 */
1174 	if (from == 0 || to == 0)
1175 		return X86_BR_NONE;
1176 
1177 	if (abort)
1178 		return X86_BR_ABORT | to_plm;
1179 
1180 	if (from_plm == X86_BR_USER) {
1181 		/*
1182 		 * can happen if measuring at the user level only
1183 		 * and we interrupt in a kernel thread, e.g., idle.
1184 		 */
1185 		if (!current->mm)
1186 			return X86_BR_NONE;
1187 
1188 		/* may fail if text not present */
1189 		bytes_left = copy_from_user_nmi(buf, (void __user *)from,
1190 						MAX_INSN_SIZE);
1191 		bytes_read = MAX_INSN_SIZE - bytes_left;
1192 		if (!bytes_read)
1193 			return X86_BR_NONE;
1194 
1195 		addr = buf;
1196 	} else {
1197 		/*
1198 		 * The LBR logs any address in the IP, even if the IP just
1199 		 * faulted. This means userspace can control the from address.
1200 		 * Ensure we don't blindly read any address by validating it is
1201 		 * a known text address.
1202 		 */
1203 		if (kernel_text_address(from)) {
1204 			addr = (void *)from;
1205 			/*
1206 			 * Assume we can get the maximum possible size
1207 			 * when grabbing kernel data.  This is not
1208 			 * _strictly_ true since we could possibly be
1209 			 * executing up next to a memory hole, but
1210 			 * it is very unlikely to be a problem.
1211 			 */
1212 			bytes_read = MAX_INSN_SIZE;
1213 		} else {
1214 			return X86_BR_NONE;
1215 		}
1216 	}
1217 
1218 	/*
1219 	 * decoder needs to know the ABI especially
1220 	 * on 64-bit systems running 32-bit apps
1221 	 */
1222 #ifdef CONFIG_X86_64
1223 	is64 = kernel_ip((unsigned long)addr) || any_64bit_mode(current_pt_regs());
1224 #endif
1225 	insn_init(&insn, addr, bytes_read, is64);
1226 	if (insn_get_opcode(&insn))
1227 		return X86_BR_ABORT;
1228 
1229 	switch (insn.opcode.bytes[0]) {
1230 	case 0xf:
1231 		switch (insn.opcode.bytes[1]) {
1232 		case 0x05: /* syscall */
1233 		case 0x34: /* sysenter */
1234 			ret = X86_BR_SYSCALL;
1235 			break;
1236 		case 0x07: /* sysret */
1237 		case 0x35: /* sysexit */
1238 			ret = X86_BR_SYSRET;
1239 			break;
1240 		case 0x80 ... 0x8f: /* conditional */
1241 			ret = X86_BR_JCC;
1242 			break;
1243 		default:
1244 			ret = X86_BR_NONE;
1245 		}
1246 		break;
1247 	case 0x70 ... 0x7f: /* conditional */
1248 		ret = X86_BR_JCC;
1249 		break;
1250 	case 0xc2: /* near ret */
1251 	case 0xc3: /* near ret */
1252 	case 0xca: /* far ret */
1253 	case 0xcb: /* far ret */
1254 		ret = X86_BR_RET;
1255 		break;
1256 	case 0xcf: /* iret */
1257 		ret = X86_BR_IRET;
1258 		break;
1259 	case 0xcc ... 0xce: /* int */
1260 		ret = X86_BR_INT;
1261 		break;
1262 	case 0xe8: /* call near rel */
1263 		if (insn_get_immediate(&insn) || insn.immediate1.value == 0) {
1264 			/* zero length call */
1265 			ret = X86_BR_ZERO_CALL;
1266 			break;
1267 		}
1268 		fallthrough;
1269 	case 0x9a: /* call far absolute */
1270 		ret = X86_BR_CALL;
1271 		break;
1272 	case 0xe0 ... 0xe3: /* loop jmp */
1273 		ret = X86_BR_JCC;
1274 		break;
1275 	case 0xe9 ... 0xeb: /* jmp */
1276 		ret = X86_BR_JMP;
1277 		break;
1278 	case 0xff: /* call near absolute, call far absolute ind */
1279 		if (insn_get_modrm(&insn))
1280 			return X86_BR_ABORT;
1281 
1282 		ext = (insn.modrm.bytes[0] >> 3) & 0x7;
1283 		switch (ext) {
1284 		case 2: /* near ind call */
1285 		case 3: /* far ind call */
1286 			ret = X86_BR_IND_CALL;
1287 			break;
1288 		case 4:
1289 		case 5:
1290 			ret = X86_BR_IND_JMP;
1291 			break;
1292 		}
1293 		break;
1294 	default:
1295 		ret = X86_BR_NONE;
1296 	}
1297 	/*
1298 	 * interrupts, traps, faults (and thus ring transition) may
1299 	 * occur on any instructions. Thus, to classify them correctly,
1300 	 * we need to first look at the from and to priv levels. If they
1301 	 * are different and to is in the kernel, then it indicates
1302 	 * a ring transition. If the from instruction is not a ring
1303 	 * transition instr (syscall, systenter, int), then it means
1304 	 * it was a irq, trap or fault.
1305 	 *
1306 	 * we have no way of detecting kernel to kernel faults.
1307 	 */
1308 	if (from_plm == X86_BR_USER && to_plm == X86_BR_KERNEL
1309 	    && ret != X86_BR_SYSCALL && ret != X86_BR_INT)
1310 		ret = X86_BR_IRQ;
1311 
1312 	/*
1313 	 * branch priv level determined by target as
1314 	 * is done by HW when LBR_SELECT is implemented
1315 	 */
1316 	if (ret != X86_BR_NONE)
1317 		ret |= to_plm;
1318 
1319 	return ret;
1320 }
1321 
1322 #define X86_BR_TYPE_MAP_MAX	16
1323 
1324 static int branch_map[X86_BR_TYPE_MAP_MAX] = {
1325 	PERF_BR_CALL,		/* X86_BR_CALL */
1326 	PERF_BR_RET,		/* X86_BR_RET */
1327 	PERF_BR_SYSCALL,	/* X86_BR_SYSCALL */
1328 	PERF_BR_SYSRET,		/* X86_BR_SYSRET */
1329 	PERF_BR_UNKNOWN,	/* X86_BR_INT */
1330 	PERF_BR_ERET,		/* X86_BR_IRET */
1331 	PERF_BR_COND,		/* X86_BR_JCC */
1332 	PERF_BR_UNCOND,		/* X86_BR_JMP */
1333 	PERF_BR_IRQ,		/* X86_BR_IRQ */
1334 	PERF_BR_IND_CALL,	/* X86_BR_IND_CALL */
1335 	PERF_BR_UNKNOWN,	/* X86_BR_ABORT */
1336 	PERF_BR_UNKNOWN,	/* X86_BR_IN_TX */
1337 	PERF_BR_UNKNOWN,	/* X86_BR_NO_TX */
1338 	PERF_BR_CALL,		/* X86_BR_ZERO_CALL */
1339 	PERF_BR_UNKNOWN,	/* X86_BR_CALL_STACK */
1340 	PERF_BR_IND,		/* X86_BR_IND_JMP */
1341 };
1342 
1343 static int
1344 common_branch_type(int type)
1345 {
1346 	int i;
1347 
1348 	type >>= 2; /* skip X86_BR_USER and X86_BR_KERNEL */
1349 
1350 	if (type) {
1351 		i = __ffs(type);
1352 		if (i < X86_BR_TYPE_MAP_MAX)
1353 			return branch_map[i];
1354 	}
1355 
1356 	return PERF_BR_UNKNOWN;
1357 }
1358 
1359 enum {
1360 	ARCH_LBR_BR_TYPE_JCC			= 0,
1361 	ARCH_LBR_BR_TYPE_NEAR_IND_JMP		= 1,
1362 	ARCH_LBR_BR_TYPE_NEAR_REL_JMP		= 2,
1363 	ARCH_LBR_BR_TYPE_NEAR_IND_CALL		= 3,
1364 	ARCH_LBR_BR_TYPE_NEAR_REL_CALL		= 4,
1365 	ARCH_LBR_BR_TYPE_NEAR_RET		= 5,
1366 	ARCH_LBR_BR_TYPE_KNOWN_MAX		= ARCH_LBR_BR_TYPE_NEAR_RET,
1367 
1368 	ARCH_LBR_BR_TYPE_MAP_MAX		= 16,
1369 };
1370 
1371 static const int arch_lbr_br_type_map[ARCH_LBR_BR_TYPE_MAP_MAX] = {
1372 	[ARCH_LBR_BR_TYPE_JCC]			= X86_BR_JCC,
1373 	[ARCH_LBR_BR_TYPE_NEAR_IND_JMP]		= X86_BR_IND_JMP,
1374 	[ARCH_LBR_BR_TYPE_NEAR_REL_JMP]		= X86_BR_JMP,
1375 	[ARCH_LBR_BR_TYPE_NEAR_IND_CALL]	= X86_BR_IND_CALL,
1376 	[ARCH_LBR_BR_TYPE_NEAR_REL_CALL]	= X86_BR_CALL,
1377 	[ARCH_LBR_BR_TYPE_NEAR_RET]		= X86_BR_RET,
1378 };
1379 
1380 /*
1381  * implement actual branch filter based on user demand.
1382  * Hardware may not exactly satisfy that request, thus
1383  * we need to inspect opcodes. Mismatched branches are
1384  * discarded. Therefore, the number of branches returned
1385  * in PERF_SAMPLE_BRANCH_STACK sample may vary.
1386  */
1387 static void
1388 intel_pmu_lbr_filter(struct cpu_hw_events *cpuc)
1389 {
1390 	u64 from, to;
1391 	int br_sel = cpuc->br_sel;
1392 	int i, j, type, to_plm;
1393 	bool compress = false;
1394 
1395 	/* if sampling all branches, then nothing to filter */
1396 	if (((br_sel & X86_BR_ALL) == X86_BR_ALL) &&
1397 	    ((br_sel & X86_BR_TYPE_SAVE) != X86_BR_TYPE_SAVE))
1398 		return;
1399 
1400 	for (i = 0; i < cpuc->lbr_stack.nr; i++) {
1401 
1402 		from = cpuc->lbr_entries[i].from;
1403 		to = cpuc->lbr_entries[i].to;
1404 		type = cpuc->lbr_entries[i].type;
1405 
1406 		/*
1407 		 * Parse the branch type recorded in LBR_x_INFO MSR.
1408 		 * Doesn't support OTHER_BRANCH decoding for now.
1409 		 * OTHER_BRANCH branch type still rely on software decoding.
1410 		 */
1411 		if (static_cpu_has(X86_FEATURE_ARCH_LBR) &&
1412 		    type <= ARCH_LBR_BR_TYPE_KNOWN_MAX) {
1413 			to_plm = kernel_ip(to) ? X86_BR_KERNEL : X86_BR_USER;
1414 			type = arch_lbr_br_type_map[type] | to_plm;
1415 		} else
1416 			type = branch_type(from, to, cpuc->lbr_entries[i].abort);
1417 		if (type != X86_BR_NONE && (br_sel & X86_BR_ANYTX)) {
1418 			if (cpuc->lbr_entries[i].in_tx)
1419 				type |= X86_BR_IN_TX;
1420 			else
1421 				type |= X86_BR_NO_TX;
1422 		}
1423 
1424 		/* if type does not correspond, then discard */
1425 		if (type == X86_BR_NONE || (br_sel & type) != type) {
1426 			cpuc->lbr_entries[i].from = 0;
1427 			compress = true;
1428 		}
1429 
1430 		if ((br_sel & X86_BR_TYPE_SAVE) == X86_BR_TYPE_SAVE)
1431 			cpuc->lbr_entries[i].type = common_branch_type(type);
1432 	}
1433 
1434 	if (!compress)
1435 		return;
1436 
1437 	/* remove all entries with from=0 */
1438 	for (i = 0; i < cpuc->lbr_stack.nr; ) {
1439 		if (!cpuc->lbr_entries[i].from) {
1440 			j = i;
1441 			while (++j < cpuc->lbr_stack.nr)
1442 				cpuc->lbr_entries[j-1] = cpuc->lbr_entries[j];
1443 			cpuc->lbr_stack.nr--;
1444 			if (!cpuc->lbr_entries[i].from)
1445 				continue;
1446 		}
1447 		i++;
1448 	}
1449 }
1450 
1451 void intel_pmu_store_pebs_lbrs(struct lbr_entry *lbr)
1452 {
1453 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1454 
1455 	/* Cannot get TOS for large PEBS and Arch LBR */
1456 	if (static_cpu_has(X86_FEATURE_ARCH_LBR) ||
1457 	    (cpuc->n_pebs == cpuc->n_large_pebs))
1458 		cpuc->lbr_stack.hw_idx = -1ULL;
1459 	else
1460 		cpuc->lbr_stack.hw_idx = intel_pmu_lbr_tos();
1461 
1462 	intel_pmu_store_lbr(cpuc, lbr);
1463 	intel_pmu_lbr_filter(cpuc);
1464 }
1465 
1466 /*
1467  * Map interface branch filters onto LBR filters
1468  */
1469 static const int nhm_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = {
1470 	[PERF_SAMPLE_BRANCH_ANY_SHIFT]		= LBR_ANY,
1471 	[PERF_SAMPLE_BRANCH_USER_SHIFT]		= LBR_USER,
1472 	[PERF_SAMPLE_BRANCH_KERNEL_SHIFT]	= LBR_KERNEL,
1473 	[PERF_SAMPLE_BRANCH_HV_SHIFT]		= LBR_IGN,
1474 	[PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT]	= LBR_RETURN | LBR_REL_JMP
1475 						| LBR_IND_JMP | LBR_FAR,
1476 	/*
1477 	 * NHM/WSM erratum: must include REL_JMP+IND_JMP to get CALL branches
1478 	 */
1479 	[PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT] =
1480 	 LBR_REL_CALL | LBR_IND_CALL | LBR_REL_JMP | LBR_IND_JMP | LBR_FAR,
1481 	/*
1482 	 * NHM/WSM erratum: must include IND_JMP to capture IND_CALL
1483 	 */
1484 	[PERF_SAMPLE_BRANCH_IND_CALL_SHIFT] = LBR_IND_CALL | LBR_IND_JMP,
1485 	[PERF_SAMPLE_BRANCH_COND_SHIFT]     = LBR_JCC,
1486 	[PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT] = LBR_IND_JMP,
1487 };
1488 
1489 static const int snb_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = {
1490 	[PERF_SAMPLE_BRANCH_ANY_SHIFT]		= LBR_ANY,
1491 	[PERF_SAMPLE_BRANCH_USER_SHIFT]		= LBR_USER,
1492 	[PERF_SAMPLE_BRANCH_KERNEL_SHIFT]	= LBR_KERNEL,
1493 	[PERF_SAMPLE_BRANCH_HV_SHIFT]		= LBR_IGN,
1494 	[PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT]	= LBR_RETURN | LBR_FAR,
1495 	[PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT]	= LBR_REL_CALL | LBR_IND_CALL
1496 						| LBR_FAR,
1497 	[PERF_SAMPLE_BRANCH_IND_CALL_SHIFT]	= LBR_IND_CALL,
1498 	[PERF_SAMPLE_BRANCH_COND_SHIFT]		= LBR_JCC,
1499 	[PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT]	= LBR_IND_JMP,
1500 	[PERF_SAMPLE_BRANCH_CALL_SHIFT]		= LBR_REL_CALL,
1501 };
1502 
1503 static const int hsw_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = {
1504 	[PERF_SAMPLE_BRANCH_ANY_SHIFT]		= LBR_ANY,
1505 	[PERF_SAMPLE_BRANCH_USER_SHIFT]		= LBR_USER,
1506 	[PERF_SAMPLE_BRANCH_KERNEL_SHIFT]	= LBR_KERNEL,
1507 	[PERF_SAMPLE_BRANCH_HV_SHIFT]		= LBR_IGN,
1508 	[PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT]	= LBR_RETURN | LBR_FAR,
1509 	[PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT]	= LBR_REL_CALL | LBR_IND_CALL
1510 						| LBR_FAR,
1511 	[PERF_SAMPLE_BRANCH_IND_CALL_SHIFT]	= LBR_IND_CALL,
1512 	[PERF_SAMPLE_BRANCH_COND_SHIFT]		= LBR_JCC,
1513 	[PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT]	= LBR_REL_CALL | LBR_IND_CALL
1514 						| LBR_RETURN | LBR_CALL_STACK,
1515 	[PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT]	= LBR_IND_JMP,
1516 	[PERF_SAMPLE_BRANCH_CALL_SHIFT]		= LBR_REL_CALL,
1517 };
1518 
1519 static int arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = {
1520 	[PERF_SAMPLE_BRANCH_ANY_SHIFT]		= ARCH_LBR_ANY,
1521 	[PERF_SAMPLE_BRANCH_USER_SHIFT]		= ARCH_LBR_USER,
1522 	[PERF_SAMPLE_BRANCH_KERNEL_SHIFT]	= ARCH_LBR_KERNEL,
1523 	[PERF_SAMPLE_BRANCH_HV_SHIFT]		= LBR_IGN,
1524 	[PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT]	= ARCH_LBR_RETURN |
1525 						  ARCH_LBR_OTHER_BRANCH,
1526 	[PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT]     = ARCH_LBR_REL_CALL |
1527 						  ARCH_LBR_IND_CALL |
1528 						  ARCH_LBR_OTHER_BRANCH,
1529 	[PERF_SAMPLE_BRANCH_IND_CALL_SHIFT]     = ARCH_LBR_IND_CALL,
1530 	[PERF_SAMPLE_BRANCH_COND_SHIFT]         = ARCH_LBR_JCC,
1531 	[PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT]   = ARCH_LBR_REL_CALL |
1532 						  ARCH_LBR_IND_CALL |
1533 						  ARCH_LBR_RETURN |
1534 						  ARCH_LBR_CALL_STACK,
1535 	[PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT]	= ARCH_LBR_IND_JMP,
1536 	[PERF_SAMPLE_BRANCH_CALL_SHIFT]		= ARCH_LBR_REL_CALL,
1537 };
1538 
1539 /* core */
1540 void __init intel_pmu_lbr_init_core(void)
1541 {
1542 	x86_pmu.lbr_nr     = 4;
1543 	x86_pmu.lbr_tos    = MSR_LBR_TOS;
1544 	x86_pmu.lbr_from   = MSR_LBR_CORE_FROM;
1545 	x86_pmu.lbr_to     = MSR_LBR_CORE_TO;
1546 
1547 	/*
1548 	 * SW branch filter usage:
1549 	 * - compensate for lack of HW filter
1550 	 */
1551 }
1552 
1553 /* nehalem/westmere */
1554 void __init intel_pmu_lbr_init_nhm(void)
1555 {
1556 	x86_pmu.lbr_nr     = 16;
1557 	x86_pmu.lbr_tos    = MSR_LBR_TOS;
1558 	x86_pmu.lbr_from   = MSR_LBR_NHM_FROM;
1559 	x86_pmu.lbr_to     = MSR_LBR_NHM_TO;
1560 
1561 	x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
1562 	x86_pmu.lbr_sel_map  = nhm_lbr_sel_map;
1563 
1564 	/*
1565 	 * SW branch filter usage:
1566 	 * - workaround LBR_SEL errata (see above)
1567 	 * - support syscall, sysret capture.
1568 	 *   That requires LBR_FAR but that means far
1569 	 *   jmp need to be filtered out
1570 	 */
1571 }
1572 
1573 /* sandy bridge */
1574 void __init intel_pmu_lbr_init_snb(void)
1575 {
1576 	x86_pmu.lbr_nr	 = 16;
1577 	x86_pmu.lbr_tos	 = MSR_LBR_TOS;
1578 	x86_pmu.lbr_from = MSR_LBR_NHM_FROM;
1579 	x86_pmu.lbr_to   = MSR_LBR_NHM_TO;
1580 
1581 	x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
1582 	x86_pmu.lbr_sel_map  = snb_lbr_sel_map;
1583 
1584 	/*
1585 	 * SW branch filter usage:
1586 	 * - support syscall, sysret capture.
1587 	 *   That requires LBR_FAR but that means far
1588 	 *   jmp need to be filtered out
1589 	 */
1590 }
1591 
1592 static inline struct kmem_cache *
1593 create_lbr_kmem_cache(size_t size, size_t align)
1594 {
1595 	return kmem_cache_create("x86_lbr", size, align, 0, NULL);
1596 }
1597 
1598 /* haswell */
1599 void intel_pmu_lbr_init_hsw(void)
1600 {
1601 	size_t size = sizeof(struct x86_perf_task_context);
1602 
1603 	x86_pmu.lbr_nr	 = 16;
1604 	x86_pmu.lbr_tos	 = MSR_LBR_TOS;
1605 	x86_pmu.lbr_from = MSR_LBR_NHM_FROM;
1606 	x86_pmu.lbr_to   = MSR_LBR_NHM_TO;
1607 
1608 	x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
1609 	x86_pmu.lbr_sel_map  = hsw_lbr_sel_map;
1610 
1611 	x86_get_pmu(smp_processor_id())->task_ctx_cache = create_lbr_kmem_cache(size, 0);
1612 
1613 	if (lbr_from_signext_quirk_needed())
1614 		static_branch_enable(&lbr_from_quirk_key);
1615 }
1616 
1617 /* skylake */
1618 __init void intel_pmu_lbr_init_skl(void)
1619 {
1620 	size_t size = sizeof(struct x86_perf_task_context);
1621 
1622 	x86_pmu.lbr_nr	 = 32;
1623 	x86_pmu.lbr_tos	 = MSR_LBR_TOS;
1624 	x86_pmu.lbr_from = MSR_LBR_NHM_FROM;
1625 	x86_pmu.lbr_to   = MSR_LBR_NHM_TO;
1626 	x86_pmu.lbr_info = MSR_LBR_INFO_0;
1627 
1628 	x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
1629 	x86_pmu.lbr_sel_map  = hsw_lbr_sel_map;
1630 
1631 	x86_get_pmu(smp_processor_id())->task_ctx_cache = create_lbr_kmem_cache(size, 0);
1632 
1633 	/*
1634 	 * SW branch filter usage:
1635 	 * - support syscall, sysret capture.
1636 	 *   That requires LBR_FAR but that means far
1637 	 *   jmp need to be filtered out
1638 	 */
1639 }
1640 
1641 /* atom */
1642 void __init intel_pmu_lbr_init_atom(void)
1643 {
1644 	/*
1645 	 * only models starting at stepping 10 seems
1646 	 * to have an operational LBR which can freeze
1647 	 * on PMU interrupt
1648 	 */
1649 	if (boot_cpu_data.x86_model == 28
1650 	    && boot_cpu_data.x86_stepping < 10) {
1651 		pr_cont("LBR disabled due to erratum");
1652 		return;
1653 	}
1654 
1655 	x86_pmu.lbr_nr	   = 8;
1656 	x86_pmu.lbr_tos    = MSR_LBR_TOS;
1657 	x86_pmu.lbr_from   = MSR_LBR_CORE_FROM;
1658 	x86_pmu.lbr_to     = MSR_LBR_CORE_TO;
1659 
1660 	/*
1661 	 * SW branch filter usage:
1662 	 * - compensate for lack of HW filter
1663 	 */
1664 }
1665 
1666 /* slm */
1667 void __init intel_pmu_lbr_init_slm(void)
1668 {
1669 	x86_pmu.lbr_nr	   = 8;
1670 	x86_pmu.lbr_tos    = MSR_LBR_TOS;
1671 	x86_pmu.lbr_from   = MSR_LBR_CORE_FROM;
1672 	x86_pmu.lbr_to     = MSR_LBR_CORE_TO;
1673 
1674 	x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
1675 	x86_pmu.lbr_sel_map  = nhm_lbr_sel_map;
1676 
1677 	/*
1678 	 * SW branch filter usage:
1679 	 * - compensate for lack of HW filter
1680 	 */
1681 	pr_cont("8-deep LBR, ");
1682 }
1683 
1684 /* Knights Landing */
1685 void intel_pmu_lbr_init_knl(void)
1686 {
1687 	x86_pmu.lbr_nr	   = 8;
1688 	x86_pmu.lbr_tos    = MSR_LBR_TOS;
1689 	x86_pmu.lbr_from   = MSR_LBR_NHM_FROM;
1690 	x86_pmu.lbr_to     = MSR_LBR_NHM_TO;
1691 
1692 	x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
1693 	x86_pmu.lbr_sel_map  = snb_lbr_sel_map;
1694 
1695 	/* Knights Landing does have MISPREDICT bit */
1696 	if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_LIP)
1697 		x86_pmu.intel_cap.lbr_format = LBR_FORMAT_EIP_FLAGS;
1698 }
1699 
1700 void intel_pmu_lbr_init(void)
1701 {
1702 	switch (x86_pmu.intel_cap.lbr_format) {
1703 	case LBR_FORMAT_EIP_FLAGS2:
1704 		x86_pmu.lbr_has_tsx = 1;
1705 		fallthrough;
1706 	case LBR_FORMAT_EIP_FLAGS:
1707 		x86_pmu.lbr_from_flags = 1;
1708 		break;
1709 
1710 	case LBR_FORMAT_INFO:
1711 		x86_pmu.lbr_has_tsx = 1;
1712 		fallthrough;
1713 	case LBR_FORMAT_INFO2:
1714 		x86_pmu.lbr_has_info = 1;
1715 		break;
1716 
1717 	case LBR_FORMAT_TIME:
1718 		x86_pmu.lbr_from_flags = 1;
1719 		x86_pmu.lbr_to_cycles = 1;
1720 		break;
1721 	}
1722 
1723 	if (x86_pmu.lbr_has_info) {
1724 		/*
1725 		 * Only used in combination with baseline pebs.
1726 		 */
1727 		static_branch_enable(&x86_lbr_mispred);
1728 		static_branch_enable(&x86_lbr_cycles);
1729 	}
1730 }
1731 
1732 /*
1733  * LBR state size is variable based on the max number of registers.
1734  * This calculates the expected state size, which should match
1735  * what the hardware enumerates for the size of XFEATURE_LBR.
1736  */
1737 static inline unsigned int get_lbr_state_size(void)
1738 {
1739 	return sizeof(struct arch_lbr_state) +
1740 	       x86_pmu.lbr_nr * sizeof(struct lbr_entry);
1741 }
1742 
1743 static bool is_arch_lbr_xsave_available(void)
1744 {
1745 	if (!boot_cpu_has(X86_FEATURE_XSAVES))
1746 		return false;
1747 
1748 	/*
1749 	 * Check the LBR state with the corresponding software structure.
1750 	 * Disable LBR XSAVES support if the size doesn't match.
1751 	 */
1752 	if (xfeature_size(XFEATURE_LBR) == 0)
1753 		return false;
1754 
1755 	if (WARN_ON(xfeature_size(XFEATURE_LBR) != get_lbr_state_size()))
1756 		return false;
1757 
1758 	return true;
1759 }
1760 
1761 void __init intel_pmu_arch_lbr_init(void)
1762 {
1763 	struct pmu *pmu = x86_get_pmu(smp_processor_id());
1764 	union cpuid28_eax eax;
1765 	union cpuid28_ebx ebx;
1766 	union cpuid28_ecx ecx;
1767 	unsigned int unused_edx;
1768 	bool arch_lbr_xsave;
1769 	size_t size;
1770 	u64 lbr_nr;
1771 
1772 	/* Arch LBR Capabilities */
1773 	cpuid(28, &eax.full, &ebx.full, &ecx.full, &unused_edx);
1774 
1775 	lbr_nr = fls(eax.split.lbr_depth_mask) * 8;
1776 	if (!lbr_nr)
1777 		goto clear_arch_lbr;
1778 
1779 	/* Apply the max depth of Arch LBR */
1780 	if (wrmsrl_safe(MSR_ARCH_LBR_DEPTH, lbr_nr))
1781 		goto clear_arch_lbr;
1782 
1783 	x86_pmu.lbr_depth_mask = eax.split.lbr_depth_mask;
1784 	x86_pmu.lbr_deep_c_reset = eax.split.lbr_deep_c_reset;
1785 	x86_pmu.lbr_lip = eax.split.lbr_lip;
1786 	x86_pmu.lbr_cpl = ebx.split.lbr_cpl;
1787 	x86_pmu.lbr_filter = ebx.split.lbr_filter;
1788 	x86_pmu.lbr_call_stack = ebx.split.lbr_call_stack;
1789 	x86_pmu.lbr_mispred = ecx.split.lbr_mispred;
1790 	x86_pmu.lbr_timed_lbr = ecx.split.lbr_timed_lbr;
1791 	x86_pmu.lbr_br_type = ecx.split.lbr_br_type;
1792 	x86_pmu.lbr_nr = lbr_nr;
1793 
1794 	if (x86_pmu.lbr_mispred)
1795 		static_branch_enable(&x86_lbr_mispred);
1796 	if (x86_pmu.lbr_timed_lbr)
1797 		static_branch_enable(&x86_lbr_cycles);
1798 	if (x86_pmu.lbr_br_type)
1799 		static_branch_enable(&x86_lbr_type);
1800 
1801 	arch_lbr_xsave = is_arch_lbr_xsave_available();
1802 	if (arch_lbr_xsave) {
1803 		size = sizeof(struct x86_perf_task_context_arch_lbr_xsave) +
1804 		       get_lbr_state_size();
1805 		pmu->task_ctx_cache = create_lbr_kmem_cache(size,
1806 							    XSAVE_ALIGNMENT);
1807 	}
1808 
1809 	if (!pmu->task_ctx_cache) {
1810 		arch_lbr_xsave = false;
1811 
1812 		size = sizeof(struct x86_perf_task_context_arch_lbr) +
1813 		       lbr_nr * sizeof(struct lbr_entry);
1814 		pmu->task_ctx_cache = create_lbr_kmem_cache(size, 0);
1815 	}
1816 
1817 	x86_pmu.lbr_from = MSR_ARCH_LBR_FROM_0;
1818 	x86_pmu.lbr_to = MSR_ARCH_LBR_TO_0;
1819 	x86_pmu.lbr_info = MSR_ARCH_LBR_INFO_0;
1820 
1821 	/* LBR callstack requires both CPL and Branch Filtering support */
1822 	if (!x86_pmu.lbr_cpl ||
1823 	    !x86_pmu.lbr_filter ||
1824 	    !x86_pmu.lbr_call_stack)
1825 		arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT] = LBR_NOT_SUPP;
1826 
1827 	if (!x86_pmu.lbr_cpl) {
1828 		arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_USER_SHIFT] = LBR_NOT_SUPP;
1829 		arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_KERNEL_SHIFT] = LBR_NOT_SUPP;
1830 	} else if (!x86_pmu.lbr_filter) {
1831 		arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_ANY_SHIFT] = LBR_NOT_SUPP;
1832 		arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT] = LBR_NOT_SUPP;
1833 		arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT] = LBR_NOT_SUPP;
1834 		arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_IND_CALL_SHIFT] = LBR_NOT_SUPP;
1835 		arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_COND_SHIFT] = LBR_NOT_SUPP;
1836 		arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT] = LBR_NOT_SUPP;
1837 		arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_CALL_SHIFT] = LBR_NOT_SUPP;
1838 	}
1839 
1840 	x86_pmu.lbr_ctl_mask = ARCH_LBR_CTL_MASK;
1841 	x86_pmu.lbr_ctl_map  = arch_lbr_ctl_map;
1842 
1843 	if (!x86_pmu.lbr_cpl && !x86_pmu.lbr_filter)
1844 		x86_pmu.lbr_ctl_map = NULL;
1845 
1846 	x86_pmu.lbr_reset = intel_pmu_arch_lbr_reset;
1847 	if (arch_lbr_xsave) {
1848 		x86_pmu.lbr_save = intel_pmu_arch_lbr_xsaves;
1849 		x86_pmu.lbr_restore = intel_pmu_arch_lbr_xrstors;
1850 		x86_pmu.lbr_read = intel_pmu_arch_lbr_read_xsave;
1851 		pr_cont("XSAVE ");
1852 	} else {
1853 		x86_pmu.lbr_save = intel_pmu_arch_lbr_save;
1854 		x86_pmu.lbr_restore = intel_pmu_arch_lbr_restore;
1855 		x86_pmu.lbr_read = intel_pmu_arch_lbr_read;
1856 	}
1857 
1858 	pr_cont("Architectural LBR, ");
1859 
1860 	return;
1861 
1862 clear_arch_lbr:
1863 	clear_cpu_cap(&boot_cpu_data, X86_FEATURE_ARCH_LBR);
1864 }
1865 
1866 /**
1867  * x86_perf_get_lbr - get the LBR records information
1868  *
1869  * @lbr: the caller's memory to store the LBR records information
1870  *
1871  * Returns: 0 indicates the LBR info has been successfully obtained
1872  */
1873 int x86_perf_get_lbr(struct x86_pmu_lbr *lbr)
1874 {
1875 	int lbr_fmt = x86_pmu.intel_cap.lbr_format;
1876 
1877 	lbr->nr = x86_pmu.lbr_nr;
1878 	lbr->from = x86_pmu.lbr_from;
1879 	lbr->to = x86_pmu.lbr_to;
1880 	lbr->info = (lbr_fmt == LBR_FORMAT_INFO) ? x86_pmu.lbr_info : 0;
1881 
1882 	return 0;
1883 }
1884 EXPORT_SYMBOL_GPL(x86_perf_get_lbr);
1885 
1886 struct event_constraint vlbr_constraint =
1887 	__EVENT_CONSTRAINT(INTEL_FIXED_VLBR_EVENT, (1ULL << INTEL_PMC_IDX_FIXED_VLBR),
1888 			  FIXED_EVENT_FLAGS, 1, 0, PERF_X86_EVENT_LBR_SELECT);
1889