arch/x86/events/intel/lbr.c

   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         u64 tos = intel_pmu_lbr_tos();
 773         int i;
 774
 775         for (i = 0; i < x86_pmu.lbr_nr; i++) {
 776                 unsigned long lbr_idx = (tos - i) & mask;
 777                 union {
 778                         struct {
 779                                 u32 from;
 780                                 u32 to;
 781                         };
 782                         u64     lbr;
 783                 } msr_lastbranch;
 784
 785                 rdmsrl(x86_pmu.lbr_from + lbr_idx, msr_lastbranch.lbr);
 786
 787                 cpuc->lbr_entries[i].from       = msr_lastbranch.from;
 788                 cpuc->lbr_entries[i].to         = msr_lastbranch.to;
 789                 cpuc->lbr_entries[i].mispred    = 0;
 790                 cpuc->lbr_entries[i].predicted  = 0;
 791                 cpuc->lbr_entries[i].in_tx      = 0;
 792                 cpuc->lbr_entries[i].abort      = 0;
 793                 cpuc->lbr_entries[i].cycles     = 0;
 794                 cpuc->lbr_entries[i].type       = 0;
 795                 cpuc->lbr_entries[i].reserved   = 0;
 796         }
 797         cpuc->lbr_stack.nr = i;
 798         cpuc->lbr_stack.hw_idx = tos;
 799 }
 800
 801 /*
 802  * Due to lack of segmentation in Linux the effective address (offset)
 803  * is the same as the linear address, allowing us to merge the LIP and EIP
 804  * LBR formats.
 805  */
 806 void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc)
 807 {
 808         bool need_info = false, call_stack = false;
 809         unsigned long mask = x86_pmu.lbr_nr - 1;
 810         u64 tos = intel_pmu_lbr_tos();
 811         int i;
 812         int out = 0;
 813         int num = x86_pmu.lbr_nr;
 814
 815         if (cpuc->lbr_sel) {
 816                 need_info = !(cpuc->lbr_sel->config & LBR_NO_INFO);
 817                 if (cpuc->lbr_sel->config & LBR_CALL_STACK)
 818                         call_stack = true;
 819         }
 820
 821         for (i = 0; i < num; i++) {
 822                 unsigned long lbr_idx = (tos - i) & mask;
 823                 u64 from, to, mis = 0, pred = 0, in_tx = 0, abort = 0;
 824                 u16 cycles = 0;
 825
 826                 from = rdlbr_from(lbr_idx, NULL);
 827                 to   = rdlbr_to(lbr_idx, NULL);
 828
 829                 /*
 830                  * Read LBR call stack entries
 831                  * until invalid entry (0s) is detected.
 832                  */
 833                 if (call_stack && !from)
 834                         break;
 835
 836                 if (x86_pmu.lbr_has_info) {
 837                         if (need_info) {
 838                                 u64 info;
 839
 840                                 info = rdlbr_info(lbr_idx, NULL);
 841                                 mis = !!(info & LBR_INFO_MISPRED);
 842                                 pred = !mis;
 843                                 cycles = (info & LBR_INFO_CYCLES);
 844                                 if (x86_pmu.lbr_has_tsx) {
 845                                         in_tx = !!(info & LBR_INFO_IN_TX);
 846                                         abort = !!(info & LBR_INFO_ABORT);
 847                                 }
 848                         }
 849                 } else {
 850                         int skip = 0;
 851
 852                         if (x86_pmu.lbr_from_flags) {
 853                                 mis = !!(from & LBR_FROM_FLAG_MISPRED);
 854                                 pred = !mis;
 855                                 skip = 1;
 856                         }
 857                         if (x86_pmu.lbr_has_tsx) {
 858                                 in_tx = !!(from & LBR_FROM_FLAG_IN_TX);
 859                                 abort = !!(from & LBR_FROM_FLAG_ABORT);
 860                                 skip = 3;
 861                         }
 862                         from = (u64)((((s64)from) << skip) >> skip);
 863
 864                         if (x86_pmu.lbr_to_cycles) {
 865                                 cycles = ((to >> 48) & LBR_INFO_CYCLES);
 866                                 to = (u64)((((s64)to) << 16) >> 16);
 867                         }
 868                 }
 869
 870                 /*
 871                  * Some CPUs report duplicated abort records,
 872                  * with the second entry not having an abort bit set.
 873                  * Skip them here. This loop runs backwards,
 874                  * so we need to undo the previous record.
 875                  * If the abort just happened outside the window
 876                  * the extra entry cannot be removed.
 877                  */
 878                 if (abort && x86_pmu.lbr_double_abort && out > 0)
 879                         out--;
 880
 881                 cpuc->lbr_entries[out].from      = from;
 882                 cpuc->lbr_entries[out].to        = to;
 883                 cpuc->lbr_entries[out].mispred   = mis;
 884                 cpuc->lbr_entries[out].predicted = pred;
 885                 cpuc->lbr_entries[out].in_tx     = in_tx;
 886                 cpuc->lbr_entries[out].abort     = abort;
 887                 cpuc->lbr_entries[out].cycles    = cycles;
 888                 cpuc->lbr_entries[out].type      = 0;
 889                 cpuc->lbr_entries[out].reserved  = 0;
 890                 out++;
 891         }
 892         cpuc->lbr_stack.nr = out;
 893         cpuc->lbr_stack.hw_idx = tos;
 894 }
 895
 896 static DEFINE_STATIC_KEY_FALSE(x86_lbr_mispred);
 897 static DEFINE_STATIC_KEY_FALSE(x86_lbr_cycles);
 898 static DEFINE_STATIC_KEY_FALSE(x86_lbr_type);
 899
 900 static __always_inline int get_lbr_br_type(u64 info)
 901 {
 902         int type = 0;
 903
 904         if (static_branch_likely(&x86_lbr_type))
 905                 type = (info & LBR_INFO_BR_TYPE) >> LBR_INFO_BR_TYPE_OFFSET;
 906
 907         return type;
 908 }
 909
 910 static __always_inline bool get_lbr_mispred(u64 info)
 911 {
 912         bool mispred = 0;
 913
 914         if (static_branch_likely(&x86_lbr_mispred))
 915                 mispred = !!(info & LBR_INFO_MISPRED);
 916
 917         return mispred;
 918 }
 919
 920 static __always_inline u16 get_lbr_cycles(u64 info)
 921 {
 922         u16 cycles = info & LBR_INFO_CYCLES;
 923
 924         if (static_cpu_has(X86_FEATURE_ARCH_LBR) &&
 925             (!static_branch_likely(&x86_lbr_cycles) ||
 926              !(info & LBR_INFO_CYC_CNT_VALID)))
 927                 cycles = 0;
 928
 929         return cycles;
 930 }
 931
 932 static void intel_pmu_store_lbr(struct cpu_hw_events *cpuc,
 933                                 struct lbr_entry *entries)
 934 {
 935         struct perf_branch_entry *e;
 936         struct lbr_entry *lbr;
 937         u64 from, to, info;
 938         int i;
 939
 940         for (i = 0; i < x86_pmu.lbr_nr; i++) {
 941                 lbr = entries ? &entries[i] : NULL;
 942                 e = &cpuc->lbr_entries[i];
 943
 944                 from = rdlbr_from(i, lbr);
 945                 /*
 946                  * Read LBR entries until invalid entry (0s) is detected.
 947                  */
 948                 if (!from)
 949                         break;
 950
 951                 to = rdlbr_to(i, lbr);
 952                 info = rdlbr_info(i, lbr);
 953
 954                 e->from         = from;
 955                 e->to           = to;
 956                 e->mispred      = get_lbr_mispred(info);
 957                 e->predicted    = !e->mispred;
 958                 e->in_tx        = !!(info & LBR_INFO_IN_TX);
 959                 e->abort        = !!(info & LBR_INFO_ABORT);
 960                 e->cycles       = get_lbr_cycles(info);
 961                 e->type         = get_lbr_br_type(info);
 962                 e->reserved     = 0;
 963         }
 964
 965         cpuc->lbr_stack.nr = i;
 966 }
 967
 968 static void intel_pmu_arch_lbr_read(struct cpu_hw_events *cpuc)
 969 {
 970         intel_pmu_store_lbr(cpuc, NULL);
 971 }
 972
 973 static void intel_pmu_arch_lbr_read_xsave(struct cpu_hw_events *cpuc)
 974 {
 975         struct x86_perf_task_context_arch_lbr_xsave *xsave = cpuc->lbr_xsave;
 976
 977         if (!xsave) {
 978                 intel_pmu_store_lbr(cpuc, NULL);
 979                 return;
 980         }
 981         xsaves(&xsave->xsave, XFEATURE_MASK_LBR);
 982
 983         intel_pmu_store_lbr(cpuc, xsave->lbr.entries);
 984 }
 985
 986 void intel_pmu_lbr_read(void)
 987 {
 988         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 989
 990         /*
 991          * Don't read when all LBRs users are using adaptive PEBS.
 992          *
 993          * This could be smarter and actually check the event,
 994          * but this simple approach seems to work for now.
 995          */
 996         if (!cpuc->lbr_users || vlbr_exclude_host() ||
 997             cpuc->lbr_users == cpuc->lbr_pebs_users)
 998                 return;
 999
1000         x86_pmu.lbr_read(cpuc);
1001
1002         intel_pmu_lbr_filter(cpuc);
1003 }
1004
1005 /*
1006  * SW filter is used:
1007  * - in case there is no HW filter
1008  * - in case the HW filter has errata or limitations
1009  */
1010 static int intel_pmu_setup_sw_lbr_filter(struct perf_event *event)
1011 {
1012         u64 br_type = event->attr.branch_sample_type;
1013         int mask = 0;
1014
1015         if (br_type & PERF_SAMPLE_BRANCH_USER)
1016                 mask |= X86_BR_USER;
1017
1018         if (br_type & PERF_SAMPLE_BRANCH_KERNEL)
1019                 mask |= X86_BR_KERNEL;
1020
1021         /* we ignore BRANCH_HV here */
1022
1023         if (br_type & PERF_SAMPLE_BRANCH_ANY)
1024                 mask |= X86_BR_ANY;
1025
1026         if (br_type & PERF_SAMPLE_BRANCH_ANY_CALL)
1027                 mask |= X86_BR_ANY_CALL;
1028
1029         if (br_type & PERF_SAMPLE_BRANCH_ANY_RETURN)
1030                 mask |= X86_BR_RET | X86_BR_IRET | X86_BR_SYSRET;
1031
1032         if (br_type & PERF_SAMPLE_BRANCH_IND_CALL)
1033                 mask |= X86_BR_IND_CALL;
1034
1035         if (br_type & PERF_SAMPLE_BRANCH_ABORT_TX)
1036                 mask |= X86_BR_ABORT;
1037
1038         if (br_type & PERF_SAMPLE_BRANCH_IN_TX)
1039                 mask |= X86_BR_IN_TX;
1040
1041         if (br_type & PERF_SAMPLE_BRANCH_NO_TX)
1042                 mask |= X86_BR_NO_TX;
1043
1044         if (br_type & PERF_SAMPLE_BRANCH_COND)
1045                 mask |= X86_BR_JCC;
1046
1047         if (br_type & PERF_SAMPLE_BRANCH_CALL_STACK) {
1048                 if (!x86_pmu_has_lbr_callstack())
1049                         return -EOPNOTSUPP;
1050                 if (mask & ~(X86_BR_USER | X86_BR_KERNEL))
1051                         return -EINVAL;
1052                 mask |= X86_BR_CALL | X86_BR_IND_CALL | X86_BR_RET |
1053                         X86_BR_CALL_STACK;
1054         }
1055
1056         if (br_type & PERF_SAMPLE_BRANCH_IND_JUMP)
1057                 mask |= X86_BR_IND_JMP;
1058
1059         if (br_type & PERF_SAMPLE_BRANCH_CALL)
1060                 mask |= X86_BR_CALL | X86_BR_ZERO_CALL;
1061
1062         if (br_type & PERF_SAMPLE_BRANCH_TYPE_SAVE)
1063                 mask |= X86_BR_TYPE_SAVE;
1064
1065         /*
1066          * stash actual user request into reg, it may
1067          * be used by fixup code for some CPU
1068          */
1069         event->hw.branch_reg.reg = mask;
1070         return 0;
1071 }
1072
1073 /*
1074  * setup the HW LBR filter
1075  * Used only when available, may not be enough to disambiguate
1076  * all branches, may need the help of the SW filter
1077  */
1078 static int intel_pmu_setup_hw_lbr_filter(struct perf_event *event)
1079 {
1080         struct hw_perf_event_extra *reg;
1081         u64 br_type = event->attr.branch_sample_type;
1082         u64 mask = 0, v;
1083         int i;
1084
1085         for (i = 0; i < PERF_SAMPLE_BRANCH_MAX_SHIFT; i++) {
1086                 if (!(br_type & (1ULL << i)))
1087                         continue;
1088
1089                 v = x86_pmu.lbr_sel_map[i];
1090                 if (v == LBR_NOT_SUPP)
1091                         return -EOPNOTSUPP;
1092
1093                 if (v != LBR_IGN)
1094                         mask |= v;
1095         }
1096
1097         reg = &event->hw.branch_reg;
1098         reg->idx = EXTRA_REG_LBR;
1099
1100         if (static_cpu_has(X86_FEATURE_ARCH_LBR)) {
1101                 reg->config = mask;
1102                 return 0;
1103         }
1104
1105         /*
1106          * The first 9 bits (LBR_SEL_MASK) in LBR_SELECT operate
1107          * in suppress mode. So LBR_SELECT should be set to
1108          * (~mask & LBR_SEL_MASK) | (mask & ~LBR_SEL_MASK)
1109          * But the 10th bit LBR_CALL_STACK does not operate
1110          * in suppress mode.
1111          */
1112         reg->config = mask ^ (x86_pmu.lbr_sel_mask & ~LBR_CALL_STACK);
1113
1114         if ((br_type & PERF_SAMPLE_BRANCH_NO_CYCLES) &&
1115             (br_type & PERF_SAMPLE_BRANCH_NO_FLAGS) &&
1116             x86_pmu.lbr_has_info)
1117                 reg->config |= LBR_NO_INFO;
1118
1119         return 0;
1120 }
1121
1122 int intel_pmu_setup_lbr_filter(struct perf_event *event)
1123 {
1124         int ret = 0;
1125
1126         /*
1127          * no LBR on this PMU
1128          */
1129         if (!x86_pmu.lbr_nr)
1130                 return -EOPNOTSUPP;
1131
1132         /*
1133          * setup SW LBR filter
1134          */
1135         ret = intel_pmu_setup_sw_lbr_filter(event);
1136         if (ret)
1137                 return ret;
1138
1139         /*
1140          * setup HW LBR filter, if any
1141          */
1142         if (x86_pmu.lbr_sel_map)
1143                 ret = intel_pmu_setup_hw_lbr_filter(event);
1144
1145         return ret;
1146 }
1147
1148 /*
1149  * return the type of control flow change at address "from"
1150  * instruction is not necessarily a branch (in case of interrupt).
1151  *
1152  * The branch type returned also includes the priv level of the
1153  * target of the control flow change (X86_BR_USER, X86_BR_KERNEL).
1154  *
1155  * If a branch type is unknown OR the instruction cannot be
1156  * decoded (e.g., text page not present), then X86_BR_NONE is
1157  * returned.
1158  */
1159 static int branch_type(unsigned long from, unsigned long to, int abort)
1160 {
1161         struct insn insn;
1162         void *addr;
1163         int bytes_read, bytes_left;
1164         int ret = X86_BR_NONE;
1165         int ext, to_plm, from_plm;
1166         u8 buf[MAX_INSN_SIZE];
1167         int is64 = 0;
1168
1169         to_plm = kernel_ip(to) ? X86_BR_KERNEL : X86_BR_USER;
1170         from_plm = kernel_ip(from) ? X86_BR_KERNEL : X86_BR_USER;
1171
1172         /*
1173          * maybe zero if lbr did not fill up after a reset by the time
1174          * we get a PMU interrupt
1175          */
1176         if (from == 0 || to == 0)
1177                 return X86_BR_NONE;
1178
1179         if (abort)
1180                 return X86_BR_ABORT | to_plm;
1181
1182         if (from_plm == X86_BR_USER) {
1183                 /*
1184                  * can happen if measuring at the user level only
1185                  * and we interrupt in a kernel thread, e.g., idle.
1186                  */
1187                 if (!current->mm)
1188                         return X86_BR_NONE;
1189
1190                 /* may fail if text not present */
1191                 bytes_left = copy_from_user_nmi(buf, (void __user *)from,
1192                                                 MAX_INSN_SIZE);
1193                 bytes_read = MAX_INSN_SIZE - bytes_left;
1194                 if (!bytes_read)
1195                         return X86_BR_NONE;
1196
1197                 addr = buf;
1198         } else {
1199                 /*
1200                  * The LBR logs any address in the IP, even if the IP just
1201                  * faulted. This means userspace can control the from address.
1202                  * Ensure we don't blindly read any address by validating it is
1203                  * a known text address.
1204                  */
1205                 if (kernel_text_address(from)) {
1206                         addr = (void *)from;
1207                         /*
1208                          * Assume we can get the maximum possible size
1209                          * when grabbing kernel data.  This is not
1210                          * _strictly_ true since we could possibly be
1211                          * executing up next to a memory hole, but
1212                          * it is very unlikely to be a problem.
1213                          */
1214                         bytes_read = MAX_INSN_SIZE;
1215                 } else {
1216                         return X86_BR_NONE;
1217                 }
1218         }
1219
1220         /*
1221          * decoder needs to know the ABI especially
1222          * on 64-bit systems running 32-bit apps
1223          */
1224 #ifdef CONFIG_X86_64
1225         is64 = kernel_ip((unsigned long)addr) || any_64bit_mode(current_pt_regs());
1226 #endif
1227         insn_init(&insn, addr, bytes_read, is64);
1228         if (insn_get_opcode(&insn))
1229                 return X86_BR_ABORT;
1230
1231         switch (insn.opcode.bytes[0]) {
1232         case 0xf:
1233                 switch (insn.opcode.bytes[1]) {
1234                 case 0x05: /* syscall */
1235                 case 0x34: /* sysenter */
1236                         ret = X86_BR_SYSCALL;
1237                         break;
1238                 case 0x07: /* sysret */
1239                 case 0x35: /* sysexit */
1240                         ret = X86_BR_SYSRET;
1241                         break;
1242                 case 0x80 ... 0x8f: /* conditional */
1243                         ret = X86_BR_JCC;
1244                         break;
1245                 default:
1246                         ret = X86_BR_NONE;
1247                 }
1248                 break;
1249         case 0x70 ... 0x7f: /* conditional */
1250                 ret = X86_BR_JCC;
1251                 break;
1252         case 0xc2: /* near ret */
1253         case 0xc3: /* near ret */
1254         case 0xca: /* far ret */
1255         case 0xcb: /* far ret */
1256                 ret = X86_BR_RET;
1257                 break;
1258         case 0xcf: /* iret */
1259                 ret = X86_BR_IRET;
1260                 break;
1261         case 0xcc ... 0xce: /* int */
1262                 ret = X86_BR_INT;
1263                 break;
1264         case 0xe8: /* call near rel */
1265                 if (insn_get_immediate(&insn) || insn.immediate1.value == 0) {
1266                         /* zero length call */
1267                         ret = X86_BR_ZERO_CALL;
1268                         break;
1269                 }
1270                 fallthrough;
1271         case 0x9a: /* call far absolute */
1272                 ret = X86_BR_CALL;
1273                 break;
1274         case 0xe0 ... 0xe3: /* loop jmp */
1275                 ret = X86_BR_JCC;
1276                 break;
1277         case 0xe9 ... 0xeb: /* jmp */
1278                 ret = X86_BR_JMP;
1279                 break;
1280         case 0xff: /* call near absolute, call far absolute ind */
1281                 if (insn_get_modrm(&insn))
1282                         return X86_BR_ABORT;
1283
1284                 ext = (insn.modrm.bytes[0] >> 3) & 0x7;
1285                 switch (ext) {
1286                 case 2: /* near ind call */
1287                 case 3: /* far ind call */
1288                         ret = X86_BR_IND_CALL;
1289                         break;
1290                 case 4:
1291                 case 5:
1292                         ret = X86_BR_IND_JMP;
1293                         break;
1294                 }
1295                 break;
1296         default:
1297                 ret = X86_BR_NONE;
1298         }
1299         /*
1300          * interrupts, traps, faults (and thus ring transition) may
1301          * occur on any instructions. Thus, to classify them correctly,
1302          * we need to first look at the from and to priv levels. If they
1303          * are different and to is in the kernel, then it indicates
1304          * a ring transition. If the from instruction is not a ring
1305          * transition instr (syscall, systenter, int), then it means
1306          * it was a irq, trap or fault.
1307          *
1308          * we have no way of detecting kernel to kernel faults.
1309          */
1310         if (from_plm == X86_BR_USER && to_plm == X86_BR_KERNEL
1311             && ret != X86_BR_SYSCALL && ret != X86_BR_INT)
1312                 ret = X86_BR_IRQ;
1313
1314         /*
1315          * branch priv level determined by target as
1316          * is done by HW when LBR_SELECT is implemented
1317          */
1318         if (ret != X86_BR_NONE)
1319                 ret |= to_plm;
1320
1321         return ret;
1322 }
1323
1324 #define X86_BR_TYPE_MAP_MAX     16
1325
1326 static int branch_map[X86_BR_TYPE_MAP_MAX] = {
1327         PERF_BR_CALL,           /* X86_BR_CALL */
1328         PERF_BR_RET,            /* X86_BR_RET */
1329         PERF_BR_SYSCALL,        /* X86_BR_SYSCALL */
1330         PERF_BR_SYSRET,         /* X86_BR_SYSRET */
1331         PERF_BR_UNKNOWN,        /* X86_BR_INT */
1332         PERF_BR_UNKNOWN,        /* X86_BR_IRET */
1333         PERF_BR_COND,           /* X86_BR_JCC */
1334         PERF_BR_UNCOND,         /* X86_BR_JMP */
1335         PERF_BR_UNKNOWN,        /* X86_BR_IRQ */
1336         PERF_BR_IND_CALL,       /* X86_BR_IND_CALL */
1337         PERF_BR_UNKNOWN,        /* X86_BR_ABORT */
1338         PERF_BR_UNKNOWN,        /* X86_BR_IN_TX */
1339         PERF_BR_UNKNOWN,        /* X86_BR_NO_TX */
1340         PERF_BR_CALL,           /* X86_BR_ZERO_CALL */
1341         PERF_BR_UNKNOWN,        /* X86_BR_CALL_STACK */
1342         PERF_BR_IND,            /* X86_BR_IND_JMP */
1343 };
1344
1345 static int
1346 common_branch_type(int type)
1347 {
1348         int i;
1349
1350         type >>= 2; /* skip X86_BR_USER and X86_BR_KERNEL */
1351
1352         if (type) {
1353                 i = __ffs(type);
1354                 if (i < X86_BR_TYPE_MAP_MAX)
1355                         return branch_map[i];
1356         }
1357
1358         return PERF_BR_UNKNOWN;
1359 }
1360
1361 enum {
1362         ARCH_LBR_BR_TYPE_JCC                    = 0,
1363         ARCH_LBR_BR_TYPE_NEAR_IND_JMP           = 1,
1364         ARCH_LBR_BR_TYPE_NEAR_REL_JMP           = 2,
1365         ARCH_LBR_BR_TYPE_NEAR_IND_CALL          = 3,
1366         ARCH_LBR_BR_TYPE_NEAR_REL_CALL          = 4,
1367         ARCH_LBR_BR_TYPE_NEAR_RET               = 5,
1368         ARCH_LBR_BR_TYPE_KNOWN_MAX              = ARCH_LBR_BR_TYPE_NEAR_RET,
1369
1370         ARCH_LBR_BR_TYPE_MAP_MAX                = 16,
1371 };
1372
1373 static const int arch_lbr_br_type_map[ARCH_LBR_BR_TYPE_MAP_MAX] = {
1374         [ARCH_LBR_BR_TYPE_JCC]                  = X86_BR_JCC,
1375         [ARCH_LBR_BR_TYPE_NEAR_IND_JMP]         = X86_BR_IND_JMP,
1376         [ARCH_LBR_BR_TYPE_NEAR_REL_JMP]         = X86_BR_JMP,
1377         [ARCH_LBR_BR_TYPE_NEAR_IND_CALL]        = X86_BR_IND_CALL,
1378         [ARCH_LBR_BR_TYPE_NEAR_REL_CALL]        = X86_BR_CALL,
1379         [ARCH_LBR_BR_TYPE_NEAR_RET]             = X86_BR_RET,
1380 };
1381
1382 /*
1383  * implement actual branch filter based on user demand.
1384  * Hardware may not exactly satisfy that request, thus
1385  * we need to inspect opcodes. Mismatched branches are
1386  * discarded. Therefore, the number of branches returned
1387  * in PERF_SAMPLE_BRANCH_STACK sample may vary.
1388  */
1389 static void
1390 intel_pmu_lbr_filter(struct cpu_hw_events *cpuc)
1391 {
1392         u64 from, to;
1393         int br_sel = cpuc->br_sel;
1394         int i, j, type, to_plm;
1395         bool compress = false;
1396
1397         /* if sampling all branches, then nothing to filter */
1398         if (((br_sel & X86_BR_ALL) == X86_BR_ALL) &&
1399             ((br_sel & X86_BR_TYPE_SAVE) != X86_BR_TYPE_SAVE))
1400                 return;
1401
1402         for (i = 0; i < cpuc->lbr_stack.nr; i++) {
1403
1404                 from = cpuc->lbr_entries[i].from;
1405                 to = cpuc->lbr_entries[i].to;
1406                 type = cpuc->lbr_entries[i].type;
1407
1408                 /*
1409                  * Parse the branch type recorded in LBR_x_INFO MSR.
1410                  * Doesn't support OTHER_BRANCH decoding for now.
1411                  * OTHER_BRANCH branch type still rely on software decoding.
1412                  */
1413                 if (static_cpu_has(X86_FEATURE_ARCH_LBR) &&
1414                     type <= ARCH_LBR_BR_TYPE_KNOWN_MAX) {
1415                         to_plm = kernel_ip(to) ? X86_BR_KERNEL : X86_BR_USER;
1416                         type = arch_lbr_br_type_map[type] | to_plm;
1417                 } else
1418                         type = branch_type(from, to, cpuc->lbr_entries[i].abort);
1419                 if (type != X86_BR_NONE && (br_sel & X86_BR_ANYTX)) {
1420                         if (cpuc->lbr_entries[i].in_tx)
1421                                 type |= X86_BR_IN_TX;
1422                         else
1423                                 type |= X86_BR_NO_TX;
1424                 }
1425
1426                 /* if type does not correspond, then discard */
1427                 if (type == X86_BR_NONE || (br_sel & type) != type) {
1428                         cpuc->lbr_entries[i].from = 0;
1429                         compress = true;
1430                 }
1431
1432                 if ((br_sel & X86_BR_TYPE_SAVE) == X86_BR_TYPE_SAVE)
1433                         cpuc->lbr_entries[i].type = common_branch_type(type);
1434         }
1435
1436         if (!compress)
1437                 return;
1438
1439         /* remove all entries with from=0 */
1440         for (i = 0; i < cpuc->lbr_stack.nr; ) {
1441                 if (!cpuc->lbr_entries[i].from) {
1442                         j = i;
1443                         while (++j < cpuc->lbr_stack.nr)
1444                                 cpuc->lbr_entries[j-1] = cpuc->lbr_entries[j];
1445                         cpuc->lbr_stack.nr--;
1446                         if (!cpuc->lbr_entries[i].from)
1447                                 continue;
1448                 }
1449                 i++;
1450         }
1451 }
1452
1453 void intel_pmu_store_pebs_lbrs(struct lbr_entry *lbr)
1454 {
1455         struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1456
1457         /* Cannot get TOS for large PEBS and Arch LBR */
1458         if (static_cpu_has(X86_FEATURE_ARCH_LBR) ||
1459             (cpuc->n_pebs == cpuc->n_large_pebs))
1460                 cpuc->lbr_stack.hw_idx = -1ULL;
1461         else
1462                 cpuc->lbr_stack.hw_idx = intel_pmu_lbr_tos();
1463
1464         intel_pmu_store_lbr(cpuc, lbr);
1465         intel_pmu_lbr_filter(cpuc);
1466 }
1467
1468 /*
1469  * Map interface branch filters onto LBR filters
1470  */
1471 static const int nhm_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = {
1472         [PERF_SAMPLE_BRANCH_ANY_SHIFT]          = LBR_ANY,
1473         [PERF_SAMPLE_BRANCH_USER_SHIFT]         = LBR_USER,
1474         [PERF_SAMPLE_BRANCH_KERNEL_SHIFT]       = LBR_KERNEL,
1475         [PERF_SAMPLE_BRANCH_HV_SHIFT]           = LBR_IGN,
1476         [PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT]   = LBR_RETURN | LBR_REL_JMP
1477                                                 | LBR_IND_JMP | LBR_FAR,
1478         /*
1479          * NHM/WSM erratum: must include REL_JMP+IND_JMP to get CALL branches
1480          */
1481         [PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT] =
1482          LBR_REL_CALL | LBR_IND_CALL | LBR_REL_JMP | LBR_IND_JMP | LBR_FAR,
1483         /*
1484          * NHM/WSM erratum: must include IND_JMP to capture IND_CALL
1485          */
1486         [PERF_SAMPLE_BRANCH_IND_CALL_SHIFT] = LBR_IND_CALL | LBR_IND_JMP,
1487         [PERF_SAMPLE_BRANCH_COND_SHIFT]     = LBR_JCC,
1488         [PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT] = LBR_IND_JMP,
1489 };
1490
1491 static const int snb_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = {
1492         [PERF_SAMPLE_BRANCH_ANY_SHIFT]          = LBR_ANY,
1493         [PERF_SAMPLE_BRANCH_USER_SHIFT]         = LBR_USER,
1494         [PERF_SAMPLE_BRANCH_KERNEL_SHIFT]       = LBR_KERNEL,
1495         [PERF_SAMPLE_BRANCH_HV_SHIFT]           = LBR_IGN,
1496         [PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT]   = LBR_RETURN | LBR_FAR,
1497         [PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT]     = LBR_REL_CALL | LBR_IND_CALL
1498                                                 | LBR_FAR,
1499         [PERF_SAMPLE_BRANCH_IND_CALL_SHIFT]     = LBR_IND_CALL,
1500         [PERF_SAMPLE_BRANCH_COND_SHIFT]         = LBR_JCC,
1501         [PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT]     = LBR_IND_JMP,
1502         [PERF_SAMPLE_BRANCH_CALL_SHIFT]         = LBR_REL_CALL,
1503 };
1504
1505 static const int hsw_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = {
1506         [PERF_SAMPLE_BRANCH_ANY_SHIFT]          = LBR_ANY,
1507         [PERF_SAMPLE_BRANCH_USER_SHIFT]         = LBR_USER,
1508         [PERF_SAMPLE_BRANCH_KERNEL_SHIFT]       = LBR_KERNEL,
1509         [PERF_SAMPLE_BRANCH_HV_SHIFT]           = LBR_IGN,
1510         [PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT]   = LBR_RETURN | LBR_FAR,
1511         [PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT]     = LBR_REL_CALL | LBR_IND_CALL
1512                                                 | LBR_FAR,
1513         [PERF_SAMPLE_BRANCH_IND_CALL_SHIFT]     = LBR_IND_CALL,
1514         [PERF_SAMPLE_BRANCH_COND_SHIFT]         = LBR_JCC,
1515         [PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT]   = LBR_REL_CALL | LBR_IND_CALL
1516                                                 | LBR_RETURN | LBR_CALL_STACK,
1517         [PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT]     = LBR_IND_JMP,
1518         [PERF_SAMPLE_BRANCH_CALL_SHIFT]         = LBR_REL_CALL,
1519 };
1520
1521 static int arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = {
1522         [PERF_SAMPLE_BRANCH_ANY_SHIFT]          = ARCH_LBR_ANY,
1523         [PERF_SAMPLE_BRANCH_USER_SHIFT]         = ARCH_LBR_USER,
1524         [PERF_SAMPLE_BRANCH_KERNEL_SHIFT]       = ARCH_LBR_KERNEL,
1525         [PERF_SAMPLE_BRANCH_HV_SHIFT]           = LBR_IGN,
1526         [PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT]   = ARCH_LBR_RETURN |
1527                                                   ARCH_LBR_OTHER_BRANCH,
1528         [PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT]     = ARCH_LBR_REL_CALL |
1529                                                   ARCH_LBR_IND_CALL |
1530                                                   ARCH_LBR_OTHER_BRANCH,
1531         [PERF_SAMPLE_BRANCH_IND_CALL_SHIFT]     = ARCH_LBR_IND_CALL,
1532         [PERF_SAMPLE_BRANCH_COND_SHIFT]         = ARCH_LBR_JCC,
1533         [PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT]   = ARCH_LBR_REL_CALL |
1534                                                   ARCH_LBR_IND_CALL |
1535                                                   ARCH_LBR_RETURN |
1536                                                   ARCH_LBR_CALL_STACK,
1537         [PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT]     = ARCH_LBR_IND_JMP,
1538         [PERF_SAMPLE_BRANCH_CALL_SHIFT]         = ARCH_LBR_REL_CALL,
1539 };
1540
1541 /* core */
1542 void __init intel_pmu_lbr_init_core(void)
1543 {
1544         x86_pmu.lbr_nr     = 4;
1545         x86_pmu.lbr_tos    = MSR_LBR_TOS;
1546         x86_pmu.lbr_from   = MSR_LBR_CORE_FROM;
1547         x86_pmu.lbr_to     = MSR_LBR_CORE_TO;
1548
1549         /*
1550          * SW branch filter usage:
1551          * - compensate for lack of HW filter
1552          */
1553 }
1554
1555 /* nehalem/westmere */
1556 void __init intel_pmu_lbr_init_nhm(void)
1557 {
1558         x86_pmu.lbr_nr     = 16;
1559         x86_pmu.lbr_tos    = MSR_LBR_TOS;
1560         x86_pmu.lbr_from   = MSR_LBR_NHM_FROM;
1561         x86_pmu.lbr_to     = MSR_LBR_NHM_TO;
1562
1563         x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
1564         x86_pmu.lbr_sel_map  = nhm_lbr_sel_map;
1565
1566         /*
1567          * SW branch filter usage:
1568          * - workaround LBR_SEL errata (see above)
1569          * - support syscall, sysret capture.
1570          *   That requires LBR_FAR but that means far
1571          *   jmp need to be filtered out
1572          */
1573 }
1574
1575 /* sandy bridge */
1576 void __init intel_pmu_lbr_init_snb(void)
1577 {
1578         x86_pmu.lbr_nr   = 16;
1579         x86_pmu.lbr_tos  = MSR_LBR_TOS;
1580         x86_pmu.lbr_from = MSR_LBR_NHM_FROM;
1581         x86_pmu.lbr_to   = MSR_LBR_NHM_TO;
1582
1583         x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
1584         x86_pmu.lbr_sel_map  = snb_lbr_sel_map;
1585
1586         /*
1587          * SW branch filter usage:
1588          * - support syscall, sysret capture.
1589          *   That requires LBR_FAR but that means far
1590          *   jmp need to be filtered out
1591          */
1592 }
1593
1594 static inline struct kmem_cache *
1595 create_lbr_kmem_cache(size_t size, size_t align)
1596 {
1597         return kmem_cache_create("x86_lbr", size, align, 0, NULL);
1598 }
1599
1600 /* haswell */
1601 void intel_pmu_lbr_init_hsw(void)
1602 {
1603         size_t size = sizeof(struct x86_perf_task_context);
1604
1605         x86_pmu.lbr_nr   = 16;
1606         x86_pmu.lbr_tos  = MSR_LBR_TOS;
1607         x86_pmu.lbr_from = MSR_LBR_NHM_FROM;
1608         x86_pmu.lbr_to   = MSR_LBR_NHM_TO;
1609
1610         x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
1611         x86_pmu.lbr_sel_map  = hsw_lbr_sel_map;
1612
1613         x86_get_pmu(smp_processor_id())->task_ctx_cache = create_lbr_kmem_cache(size, 0);
1614
1615         if (lbr_from_signext_quirk_needed())
1616                 static_branch_enable(&lbr_from_quirk_key);
1617 }
1618
1619 /* skylake */
1620 __init void intel_pmu_lbr_init_skl(void)
1621 {
1622         size_t size = sizeof(struct x86_perf_task_context);
1623
1624         x86_pmu.lbr_nr   = 32;
1625         x86_pmu.lbr_tos  = MSR_LBR_TOS;
1626         x86_pmu.lbr_from = MSR_LBR_NHM_FROM;
1627         x86_pmu.lbr_to   = MSR_LBR_NHM_TO;
1628         x86_pmu.lbr_info = MSR_LBR_INFO_0;
1629
1630         x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
1631         x86_pmu.lbr_sel_map  = hsw_lbr_sel_map;
1632
1633         x86_get_pmu(smp_processor_id())->task_ctx_cache = create_lbr_kmem_cache(size, 0);
1634
1635         /*
1636          * SW branch filter usage:
1637          * - support syscall, sysret capture.
1638          *   That requires LBR_FAR but that means far
1639          *   jmp need to be filtered out
1640          */
1641 }
1642
1643 /* atom */
1644 void __init intel_pmu_lbr_init_atom(void)
1645 {
1646         /*
1647          * only models starting at stepping 10 seems
1648          * to have an operational LBR which can freeze
1649          * on PMU interrupt
1650          */
1651         if (boot_cpu_data.x86_model == 28
1652             && boot_cpu_data.x86_stepping < 10) {
1653                 pr_cont("LBR disabled due to erratum");
1654                 return;
1655         }
1656
1657         x86_pmu.lbr_nr     = 8;
1658         x86_pmu.lbr_tos    = MSR_LBR_TOS;
1659         x86_pmu.lbr_from   = MSR_LBR_CORE_FROM;
1660         x86_pmu.lbr_to     = MSR_LBR_CORE_TO;
1661
1662         /*
1663          * SW branch filter usage:
1664          * - compensate for lack of HW filter
1665          */
1666 }
1667
1668 /* slm */
1669 void __init intel_pmu_lbr_init_slm(void)
1670 {
1671         x86_pmu.lbr_nr     = 8;
1672         x86_pmu.lbr_tos    = MSR_LBR_TOS;
1673         x86_pmu.lbr_from   = MSR_LBR_CORE_FROM;
1674         x86_pmu.lbr_to     = MSR_LBR_CORE_TO;
1675
1676         x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
1677         x86_pmu.lbr_sel_map  = nhm_lbr_sel_map;
1678
1679         /*
1680          * SW branch filter usage:
1681          * - compensate for lack of HW filter
1682          */
1683         pr_cont("8-deep LBR, ");
1684 }
1685
1686 /* Knights Landing */
1687 void intel_pmu_lbr_init_knl(void)
1688 {
1689         x86_pmu.lbr_nr     = 8;
1690         x86_pmu.lbr_tos    = MSR_LBR_TOS;
1691         x86_pmu.lbr_from   = MSR_LBR_NHM_FROM;
1692         x86_pmu.lbr_to     = MSR_LBR_NHM_TO;
1693
1694         x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
1695         x86_pmu.lbr_sel_map  = snb_lbr_sel_map;
1696
1697         /* Knights Landing does have MISPREDICT bit */
1698         if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_LIP)
1699                 x86_pmu.intel_cap.lbr_format = LBR_FORMAT_EIP_FLAGS;
1700 }
1701
1702 void intel_pmu_lbr_init(void)
1703 {
1704         switch (x86_pmu.intel_cap.lbr_format) {
1705         case LBR_FORMAT_EIP_FLAGS2:
1706                 x86_pmu.lbr_has_tsx = 1;
1707                 fallthrough;
1708         case LBR_FORMAT_EIP_FLAGS:
1709                 x86_pmu.lbr_from_flags = 1;
1710                 break;
1711
1712         case LBR_FORMAT_INFO:
1713                 x86_pmu.lbr_has_tsx = 1;
1714                 fallthrough;
1715         case LBR_FORMAT_INFO2:
1716                 x86_pmu.lbr_has_info = 1;
1717                 break;
1718
1719         case LBR_FORMAT_TIME:
1720                 x86_pmu.lbr_from_flags = 1;
1721                 x86_pmu.lbr_to_cycles = 1;
1722                 break;
1723         }
1724
1725         if (x86_pmu.lbr_has_info) {
1726                 /*
1727                  * Only used in combination with baseline pebs.
1728                  */
1729                 static_branch_enable(&x86_lbr_mispred);
1730                 static_branch_enable(&x86_lbr_cycles);
1731         }
1732 }
1733
1734 /*
1735  * LBR state size is variable based on the max number of registers.
1736  * This calculates the expected state size, which should match
1737  * what the hardware enumerates for the size of XFEATURE_LBR.
1738  */
1739 static inline unsigned int get_lbr_state_size(void)
1740 {
1741         return sizeof(struct arch_lbr_state) +
1742                x86_pmu.lbr_nr * sizeof(struct lbr_entry);
1743 }
1744
1745 static bool is_arch_lbr_xsave_available(void)
1746 {
1747         if (!boot_cpu_has(X86_FEATURE_XSAVES))
1748                 return false;
1749
1750         /*
1751          * Check the LBR state with the corresponding software structure.
1752          * Disable LBR XSAVES support if the size doesn't match.
1753          */
1754         if (xfeature_size(XFEATURE_LBR) == 0)
1755                 return false;
1756
1757         if (WARN_ON(xfeature_size(XFEATURE_LBR) != get_lbr_state_size()))
1758                 return false;
1759
1760         return true;
1761 }
1762
1763 void __init intel_pmu_arch_lbr_init(void)
1764 {
1765         struct pmu *pmu = x86_get_pmu(smp_processor_id());
1766         union cpuid28_eax eax;
1767         union cpuid28_ebx ebx;
1768         union cpuid28_ecx ecx;
1769         unsigned int unused_edx;
1770         bool arch_lbr_xsave;
1771         size_t size;
1772         u64 lbr_nr;
1773
1774         /* Arch LBR Capabilities */
1775         cpuid(28, &eax.full, &ebx.full, &ecx.full, &unused_edx);
1776
1777         lbr_nr = fls(eax.split.lbr_depth_mask) * 8;
1778         if (!lbr_nr)
1779                 goto clear_arch_lbr;
1780
1781         /* Apply the max depth of Arch LBR */
1782         if (wrmsrl_safe(MSR_ARCH_LBR_DEPTH, lbr_nr))
1783                 goto clear_arch_lbr;
1784
1785         x86_pmu.lbr_depth_mask = eax.split.lbr_depth_mask;
1786         x86_pmu.lbr_deep_c_reset = eax.split.lbr_deep_c_reset;
1787         x86_pmu.lbr_lip = eax.split.lbr_lip;
1788         x86_pmu.lbr_cpl = ebx.split.lbr_cpl;
1789         x86_pmu.lbr_filter = ebx.split.lbr_filter;
1790         x86_pmu.lbr_call_stack = ebx.split.lbr_call_stack;
1791         x86_pmu.lbr_mispred = ecx.split.lbr_mispred;
1792         x86_pmu.lbr_timed_lbr = ecx.split.lbr_timed_lbr;
1793         x86_pmu.lbr_br_type = ecx.split.lbr_br_type;
1794         x86_pmu.lbr_nr = lbr_nr;
1795
1796         if (x86_pmu.lbr_mispred)
1797                 static_branch_enable(&x86_lbr_mispred);
1798         if (x86_pmu.lbr_timed_lbr)
1799                 static_branch_enable(&x86_lbr_cycles);
1800         if (x86_pmu.lbr_br_type)
1801                 static_branch_enable(&x86_lbr_type);
1802
1803         arch_lbr_xsave = is_arch_lbr_xsave_available();
1804         if (arch_lbr_xsave) {
1805                 size = sizeof(struct x86_perf_task_context_arch_lbr_xsave) +
1806                        get_lbr_state_size();
1807                 pmu->task_ctx_cache = create_lbr_kmem_cache(size,
1808                                                             XSAVE_ALIGNMENT);
1809         }
1810
1811         if (!pmu->task_ctx_cache) {
1812                 arch_lbr_xsave = false;
1813
1814                 size = sizeof(struct x86_perf_task_context_arch_lbr) +
1815                        lbr_nr * sizeof(struct lbr_entry);
1816                 pmu->task_ctx_cache = create_lbr_kmem_cache(size, 0);
1817         }
1818
1819         x86_pmu.lbr_from = MSR_ARCH_LBR_FROM_0;
1820         x86_pmu.lbr_to = MSR_ARCH_LBR_TO_0;
1821         x86_pmu.lbr_info = MSR_ARCH_LBR_INFO_0;
1822
1823         /* LBR callstack requires both CPL and Branch Filtering support */
1824         if (!x86_pmu.lbr_cpl ||
1825             !x86_pmu.lbr_filter ||
1826             !x86_pmu.lbr_call_stack)
1827                 arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT] = LBR_NOT_SUPP;
1828
1829         if (!x86_pmu.lbr_cpl) {
1830                 arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_USER_SHIFT] = LBR_NOT_SUPP;
1831                 arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_KERNEL_SHIFT] = LBR_NOT_SUPP;
1832         } else if (!x86_pmu.lbr_filter) {
1833                 arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_ANY_SHIFT] = LBR_NOT_SUPP;
1834                 arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT] = LBR_NOT_SUPP;
1835                 arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT] = LBR_NOT_SUPP;
1836                 arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_IND_CALL_SHIFT] = LBR_NOT_SUPP;
1837                 arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_COND_SHIFT] = LBR_NOT_SUPP;
1838                 arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT] = LBR_NOT_SUPP;
1839                 arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_CALL_SHIFT] = LBR_NOT_SUPP;
1840         }
1841
1842         x86_pmu.lbr_ctl_mask = ARCH_LBR_CTL_MASK;
1843         x86_pmu.lbr_ctl_map  = arch_lbr_ctl_map;
1844
1845         if (!x86_pmu.lbr_cpl && !x86_pmu.lbr_filter)
1846                 x86_pmu.lbr_ctl_map = NULL;
1847
1848         x86_pmu.lbr_reset = intel_pmu_arch_lbr_reset;
1849         if (arch_lbr_xsave) {
1850                 x86_pmu.lbr_save = intel_pmu_arch_lbr_xsaves;
1851                 x86_pmu.lbr_restore = intel_pmu_arch_lbr_xrstors;
1852                 x86_pmu.lbr_read = intel_pmu_arch_lbr_read_xsave;
1853                 pr_cont("XSAVE ");
1854         } else {
1855                 x86_pmu.lbr_save = intel_pmu_arch_lbr_save;
1856                 x86_pmu.lbr_restore = intel_pmu_arch_lbr_restore;
1857                 x86_pmu.lbr_read = intel_pmu_arch_lbr_read;
1858         }
1859
1860         pr_cont("Architectural LBR, ");
1861
1862         return;
1863
1864 clear_arch_lbr:
1865         clear_cpu_cap(&boot_cpu_data, X86_FEATURE_ARCH_LBR);
1866 }
1867
1868 /**
1869  * x86_perf_get_lbr - get the LBR records information
1870  *
1871  * @lbr: the caller's memory to store the LBR records information
1872  *
1873  * Returns: 0 indicates the LBR info has been successfully obtained
1874  */
1875 int x86_perf_get_lbr(struct x86_pmu_lbr *lbr)
1876 {
1877         int lbr_fmt = x86_pmu.intel_cap.lbr_format;
1878
1879         lbr->nr = x86_pmu.lbr_nr;
1880         lbr->from = x86_pmu.lbr_from;
1881         lbr->to = x86_pmu.lbr_to;
1882         lbr->info = (lbr_fmt == LBR_FORMAT_INFO) ? x86_pmu.lbr_info : 0;
1883
1884         return 0;
1885 }
1886 EXPORT_SYMBOL_GPL(x86_perf_get_lbr);
1887
1888 struct event_constraint vlbr_constraint =
1889         __EVENT_CONSTRAINT(INTEL_FIXED_VLBR_EVENT, (1ULL << INTEL_PMC_IDX_FIXED_VLBR),
1890                           FIXED_EVENT_FLAGS, 1, 0, PERF_X86_EVENT_LBR_SELECT);