Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 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 | enum { |
| 12 | LBR_FORMAT_32 = 0x00, |
| 13 | LBR_FORMAT_LIP = 0x01, |
| 14 | LBR_FORMAT_EIP = 0x02, |
| 15 | LBR_FORMAT_EIP_FLAGS = 0x03, |
| 16 | LBR_FORMAT_EIP_FLAGS2 = 0x04, |
| 17 | LBR_FORMAT_INFO = 0x05, |
| 18 | LBR_FORMAT_TIME = 0x06, |
| 19 | LBR_FORMAT_MAX_KNOWN = LBR_FORMAT_TIME, |
| 20 | }; |
| 21 | |
| 22 | static const enum { |
| 23 | LBR_EIP_FLAGS = 1, |
| 24 | LBR_TSX = 2, |
| 25 | } lbr_desc[LBR_FORMAT_MAX_KNOWN + 1] = { |
| 26 | [LBR_FORMAT_EIP_FLAGS] = LBR_EIP_FLAGS, |
| 27 | [LBR_FORMAT_EIP_FLAGS2] = LBR_EIP_FLAGS | LBR_TSX, |
| 28 | }; |
| 29 | |
| 30 | /* |
| 31 | * Intel LBR_SELECT bits |
| 32 | * Intel Vol3a, April 2011, Section 16.7 Table 16-10 |
| 33 | * |
| 34 | * Hardware branch filter (not available on all CPUs) |
| 35 | */ |
| 36 | #define LBR_KERNEL_BIT 0 /* do not capture at ring0 */ |
| 37 | #define LBR_USER_BIT 1 /* do not capture at ring > 0 */ |
| 38 | #define LBR_JCC_BIT 2 /* do not capture conditional branches */ |
| 39 | #define LBR_REL_CALL_BIT 3 /* do not capture relative calls */ |
| 40 | #define LBR_IND_CALL_BIT 4 /* do not capture indirect calls */ |
| 41 | #define LBR_RETURN_BIT 5 /* do not capture near returns */ |
| 42 | #define LBR_IND_JMP_BIT 6 /* do not capture indirect jumps */ |
| 43 | #define LBR_REL_JMP_BIT 7 /* do not capture relative jumps */ |
| 44 | #define LBR_FAR_BIT 8 /* do not capture far branches */ |
| 45 | #define LBR_CALL_STACK_BIT 9 /* enable call stack */ |
| 46 | |
| 47 | /* |
| 48 | * Following bit only exists in Linux; we mask it out before writing it to |
| 49 | * the actual MSR. But it helps the constraint perf code to understand |
| 50 | * that this is a separate configuration. |
| 51 | */ |
| 52 | #define LBR_NO_INFO_BIT 63 /* don't read LBR_INFO. */ |
| 53 | |
| 54 | #define LBR_KERNEL (1 << LBR_KERNEL_BIT) |
| 55 | #define LBR_USER (1 << LBR_USER_BIT) |
| 56 | #define LBR_JCC (1 << LBR_JCC_BIT) |
| 57 | #define LBR_REL_CALL (1 << LBR_REL_CALL_BIT) |
| 58 | #define LBR_IND_CALL (1 << LBR_IND_CALL_BIT) |
| 59 | #define LBR_RETURN (1 << LBR_RETURN_BIT) |
| 60 | #define LBR_REL_JMP (1 << LBR_REL_JMP_BIT) |
| 61 | #define LBR_IND_JMP (1 << LBR_IND_JMP_BIT) |
| 62 | #define LBR_FAR (1 << LBR_FAR_BIT) |
| 63 | #define LBR_CALL_STACK (1 << LBR_CALL_STACK_BIT) |
| 64 | #define LBR_NO_INFO (1ULL << LBR_NO_INFO_BIT) |
| 65 | |
| 66 | #define LBR_PLM (LBR_KERNEL | LBR_USER) |
| 67 | |
| 68 | #define LBR_SEL_MASK 0x3ff /* valid bits in LBR_SELECT */ |
| 69 | #define LBR_NOT_SUPP -1 /* LBR filter not supported */ |
| 70 | #define LBR_IGN 0 /* ignored */ |
| 71 | |
| 72 | #define LBR_ANY \ |
| 73 | (LBR_JCC |\ |
| 74 | LBR_REL_CALL |\ |
| 75 | LBR_IND_CALL |\ |
| 76 | LBR_RETURN |\ |
| 77 | LBR_REL_JMP |\ |
| 78 | LBR_IND_JMP |\ |
| 79 | LBR_FAR) |
| 80 | |
| 81 | #define LBR_FROM_FLAG_MISPRED BIT_ULL(63) |
| 82 | #define LBR_FROM_FLAG_IN_TX BIT_ULL(62) |
| 83 | #define LBR_FROM_FLAG_ABORT BIT_ULL(61) |
| 84 | |
| 85 | #define LBR_FROM_SIGNEXT_2MSB (BIT_ULL(60) | BIT_ULL(59)) |
| 86 | |
| 87 | /* |
| 88 | * x86control flow change classification |
| 89 | * x86control flow changes include branches, interrupts, traps, faults |
| 90 | */ |
| 91 | enum { |
| 92 | X86_BR_NONE = 0, /* unknown */ |
| 93 | |
| 94 | X86_BR_USER = 1 << 0, /* branch target is user */ |
| 95 | X86_BR_KERNEL = 1 << 1, /* branch target is kernel */ |
| 96 | |
| 97 | X86_BR_CALL = 1 << 2, /* call */ |
| 98 | X86_BR_RET = 1 << 3, /* return */ |
| 99 | X86_BR_SYSCALL = 1 << 4, /* syscall */ |
| 100 | X86_BR_SYSRET = 1 << 5, /* syscall return */ |
| 101 | X86_BR_INT = 1 << 6, /* sw interrupt */ |
| 102 | X86_BR_IRET = 1 << 7, /* return from interrupt */ |
| 103 | X86_BR_JCC = 1 << 8, /* conditional */ |
| 104 | X86_BR_JMP = 1 << 9, /* jump */ |
| 105 | X86_BR_IRQ = 1 << 10,/* hw interrupt or trap or fault */ |
| 106 | X86_BR_IND_CALL = 1 << 11,/* indirect calls */ |
| 107 | X86_BR_ABORT = 1 << 12,/* transaction abort */ |
| 108 | X86_BR_IN_TX = 1 << 13,/* in transaction */ |
| 109 | X86_BR_NO_TX = 1 << 14,/* not in transaction */ |
| 110 | X86_BR_ZERO_CALL = 1 << 15,/* zero length call */ |
| 111 | X86_BR_CALL_STACK = 1 << 16,/* call stack */ |
| 112 | X86_BR_IND_JMP = 1 << 17,/* indirect jump */ |
| 113 | |
| 114 | X86_BR_TYPE_SAVE = 1 << 18,/* indicate to save branch type */ |
| 115 | |
| 116 | }; |
| 117 | |
| 118 | #define X86_BR_PLM (X86_BR_USER | X86_BR_KERNEL) |
| 119 | #define X86_BR_ANYTX (X86_BR_NO_TX | X86_BR_IN_TX) |
| 120 | |
| 121 | #define X86_BR_ANY \ |
| 122 | (X86_BR_CALL |\ |
| 123 | X86_BR_RET |\ |
| 124 | X86_BR_SYSCALL |\ |
| 125 | X86_BR_SYSRET |\ |
| 126 | X86_BR_INT |\ |
| 127 | X86_BR_IRET |\ |
| 128 | X86_BR_JCC |\ |
| 129 | X86_BR_JMP |\ |
| 130 | X86_BR_IRQ |\ |
| 131 | X86_BR_ABORT |\ |
| 132 | X86_BR_IND_CALL |\ |
| 133 | X86_BR_IND_JMP |\ |
| 134 | X86_BR_ZERO_CALL) |
| 135 | |
| 136 | #define X86_BR_ALL (X86_BR_PLM | X86_BR_ANY) |
| 137 | |
| 138 | #define X86_BR_ANY_CALL \ |
| 139 | (X86_BR_CALL |\ |
| 140 | X86_BR_IND_CALL |\ |
| 141 | X86_BR_ZERO_CALL |\ |
| 142 | X86_BR_SYSCALL |\ |
| 143 | X86_BR_IRQ |\ |
| 144 | X86_BR_INT) |
| 145 | |
| 146 | static void intel_pmu_lbr_filter(struct cpu_hw_events *cpuc); |
| 147 | |
| 148 | /* |
| 149 | * We only support LBR implementations that have FREEZE_LBRS_ON_PMI |
| 150 | * otherwise it becomes near impossible to get a reliable stack. |
| 151 | */ |
| 152 | |
| 153 | static void __intel_pmu_lbr_enable(bool pmi) |
| 154 | { |
| 155 | struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); |
| 156 | u64 debugctl, lbr_select = 0, orig_debugctl; |
| 157 | |
| 158 | /* |
| 159 | * No need to unfreeze manually, as v4 can do that as part |
| 160 | * of the GLOBAL_STATUS ack. |
| 161 | */ |
| 162 | if (pmi && x86_pmu.version >= 4) |
| 163 | return; |
| 164 | |
| 165 | /* |
| 166 | * No need to reprogram LBR_SELECT in a PMI, as it |
| 167 | * did not change. |
| 168 | */ |
| 169 | if (cpuc->lbr_sel) |
| 170 | lbr_select = cpuc->lbr_sel->config & x86_pmu.lbr_sel_mask; |
| 171 | if (!pmi && cpuc->lbr_sel) |
| 172 | wrmsrl(MSR_LBR_SELECT, lbr_select); |
| 173 | |
| 174 | rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); |
| 175 | orig_debugctl = debugctl; |
| 176 | debugctl |= DEBUGCTLMSR_LBR; |
| 177 | /* |
| 178 | * LBR callstack does not work well with FREEZE_LBRS_ON_PMI. |
| 179 | * If FREEZE_LBRS_ON_PMI is set, PMI near call/return instructions |
| 180 | * may cause superfluous increase/decrease of LBR_TOS. |
| 181 | */ |
| 182 | if (!(lbr_select & LBR_CALL_STACK)) |
| 183 | debugctl |= DEBUGCTLMSR_FREEZE_LBRS_ON_PMI; |
| 184 | if (orig_debugctl != debugctl) |
| 185 | wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); |
| 186 | } |
| 187 | |
| 188 | static void __intel_pmu_lbr_disable(void) |
| 189 | { |
| 190 | u64 debugctl; |
| 191 | |
| 192 | rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); |
| 193 | debugctl &= ~(DEBUGCTLMSR_LBR | DEBUGCTLMSR_FREEZE_LBRS_ON_PMI); |
| 194 | wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); |
| 195 | } |
| 196 | |
| 197 | static void intel_pmu_lbr_reset_32(void) |
| 198 | { |
| 199 | int i; |
| 200 | |
| 201 | for (i = 0; i < x86_pmu.lbr_nr; i++) |
| 202 | wrmsrl(x86_pmu.lbr_from + i, 0); |
| 203 | } |
| 204 | |
| 205 | static void intel_pmu_lbr_reset_64(void) |
| 206 | { |
| 207 | int i; |
| 208 | |
| 209 | for (i = 0; i < x86_pmu.lbr_nr; i++) { |
| 210 | wrmsrl(x86_pmu.lbr_from + i, 0); |
| 211 | wrmsrl(x86_pmu.lbr_to + i, 0); |
| 212 | if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO) |
| 213 | wrmsrl(MSR_LBR_INFO_0 + i, 0); |
| 214 | } |
| 215 | } |
| 216 | |
| 217 | void intel_pmu_lbr_reset(void) |
| 218 | { |
| 219 | struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); |
| 220 | |
| 221 | if (!x86_pmu.lbr_nr) |
| 222 | return; |
| 223 | |
| 224 | if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_32) |
| 225 | intel_pmu_lbr_reset_32(); |
| 226 | else |
| 227 | intel_pmu_lbr_reset_64(); |
| 228 | |
| 229 | cpuc->last_task_ctx = NULL; |
| 230 | cpuc->last_log_id = 0; |
| 231 | } |
| 232 | |
| 233 | /* |
| 234 | * TOS = most recently recorded branch |
| 235 | */ |
| 236 | static inline u64 intel_pmu_lbr_tos(void) |
| 237 | { |
| 238 | u64 tos; |
| 239 | |
| 240 | rdmsrl(x86_pmu.lbr_tos, tos); |
| 241 | return tos; |
| 242 | } |
| 243 | |
| 244 | enum { |
| 245 | LBR_NONE, |
| 246 | LBR_VALID, |
| 247 | }; |
| 248 | |
| 249 | /* |
| 250 | * For formats with LBR_TSX flags (e.g. LBR_FORMAT_EIP_FLAGS2), bits 61:62 in |
| 251 | * MSR_LAST_BRANCH_FROM_x are the TSX flags when TSX is supported, but when |
| 252 | * TSX is not supported they have no consistent behavior: |
| 253 | * |
| 254 | * - For wrmsr(), bits 61:62 are considered part of the sign extension. |
| 255 | * - For HW updates (branch captures) bits 61:62 are always OFF and are not |
| 256 | * part of the sign extension. |
| 257 | * |
| 258 | * Therefore, if: |
| 259 | * |
| 260 | * 1) LBR has TSX format |
| 261 | * 2) CPU has no TSX support enabled |
| 262 | * |
| 263 | * ... then any value passed to wrmsr() must be sign extended to 63 bits and any |
| 264 | * value from rdmsr() must be converted to have a 61 bits sign extension, |
| 265 | * ignoring the TSX flags. |
| 266 | */ |
| 267 | static inline bool lbr_from_signext_quirk_needed(void) |
| 268 | { |
| 269 | int lbr_format = x86_pmu.intel_cap.lbr_format; |
| 270 | bool tsx_support = boot_cpu_has(X86_FEATURE_HLE) || |
| 271 | boot_cpu_has(X86_FEATURE_RTM); |
| 272 | |
| 273 | return !tsx_support && (lbr_desc[lbr_format] & LBR_TSX); |
| 274 | } |
| 275 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 276 | static DEFINE_STATIC_KEY_FALSE(lbr_from_quirk_key); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 277 | |
| 278 | /* If quirk is enabled, ensure sign extension is 63 bits: */ |
| 279 | inline u64 lbr_from_signext_quirk_wr(u64 val) |
| 280 | { |
| 281 | if (static_branch_unlikely(&lbr_from_quirk_key)) { |
| 282 | /* |
| 283 | * Sign extend into bits 61:62 while preserving bit 63. |
| 284 | * |
| 285 | * Quirk is enabled when TSX is disabled. Therefore TSX bits |
| 286 | * in val are always OFF and must be changed to be sign |
| 287 | * extension bits. Since bits 59:60 are guaranteed to be |
| 288 | * part of the sign extension bits, we can just copy them |
| 289 | * to 61:62. |
| 290 | */ |
| 291 | val |= (LBR_FROM_SIGNEXT_2MSB & val) << 2; |
| 292 | } |
| 293 | return val; |
| 294 | } |
| 295 | |
| 296 | /* |
| 297 | * If quirk is needed, ensure sign extension is 61 bits: |
| 298 | */ |
| 299 | static u64 lbr_from_signext_quirk_rd(u64 val) |
| 300 | { |
| 301 | if (static_branch_unlikely(&lbr_from_quirk_key)) { |
| 302 | /* |
| 303 | * Quirk is on when TSX is not enabled. Therefore TSX |
| 304 | * flags must be read as OFF. |
| 305 | */ |
| 306 | val &= ~(LBR_FROM_FLAG_IN_TX | LBR_FROM_FLAG_ABORT); |
| 307 | } |
| 308 | return val; |
| 309 | } |
| 310 | |
| 311 | static inline void wrlbr_from(unsigned int idx, u64 val) |
| 312 | { |
| 313 | val = lbr_from_signext_quirk_wr(val); |
| 314 | wrmsrl(x86_pmu.lbr_from + idx, val); |
| 315 | } |
| 316 | |
| 317 | static inline void wrlbr_to(unsigned int idx, u64 val) |
| 318 | { |
| 319 | wrmsrl(x86_pmu.lbr_to + idx, val); |
| 320 | } |
| 321 | |
| 322 | static inline u64 rdlbr_from(unsigned int idx) |
| 323 | { |
| 324 | u64 val; |
| 325 | |
| 326 | rdmsrl(x86_pmu.lbr_from + idx, val); |
| 327 | |
| 328 | return lbr_from_signext_quirk_rd(val); |
| 329 | } |
| 330 | |
| 331 | static inline u64 rdlbr_to(unsigned int idx) |
| 332 | { |
| 333 | u64 val; |
| 334 | |
| 335 | rdmsrl(x86_pmu.lbr_to + idx, val); |
| 336 | |
| 337 | return val; |
| 338 | } |
| 339 | |
| 340 | static void __intel_pmu_lbr_restore(struct x86_perf_task_context *task_ctx) |
| 341 | { |
| 342 | struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); |
| 343 | int i; |
| 344 | unsigned lbr_idx, mask; |
| 345 | u64 tos; |
| 346 | |
| 347 | if (task_ctx->lbr_callstack_users == 0 || |
| 348 | task_ctx->lbr_stack_state == LBR_NONE) { |
| 349 | intel_pmu_lbr_reset(); |
| 350 | return; |
| 351 | } |
| 352 | |
| 353 | tos = task_ctx->tos; |
| 354 | /* |
| 355 | * Does not restore the LBR registers, if |
| 356 | * - No one else touched them, and |
| 357 | * - Did not enter C6 |
| 358 | */ |
| 359 | if ((task_ctx == cpuc->last_task_ctx) && |
| 360 | (task_ctx->log_id == cpuc->last_log_id) && |
| 361 | rdlbr_from(tos)) { |
| 362 | task_ctx->lbr_stack_state = LBR_NONE; |
| 363 | return; |
| 364 | } |
| 365 | |
| 366 | mask = x86_pmu.lbr_nr - 1; |
| 367 | for (i = 0; i < task_ctx->valid_lbrs; i++) { |
| 368 | lbr_idx = (tos - i) & mask; |
| 369 | wrlbr_from(lbr_idx, task_ctx->lbr_from[i]); |
| 370 | wrlbr_to (lbr_idx, task_ctx->lbr_to[i]); |
| 371 | |
| 372 | if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO) |
| 373 | wrmsrl(MSR_LBR_INFO_0 + lbr_idx, task_ctx->lbr_info[i]); |
| 374 | } |
| 375 | |
| 376 | for (; i < x86_pmu.lbr_nr; i++) { |
| 377 | lbr_idx = (tos - i) & mask; |
| 378 | wrlbr_from(lbr_idx, 0); |
| 379 | wrlbr_to(lbr_idx, 0); |
| 380 | if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO) |
| 381 | wrmsrl(MSR_LBR_INFO_0 + lbr_idx, 0); |
| 382 | } |
| 383 | |
| 384 | wrmsrl(x86_pmu.lbr_tos, tos); |
| 385 | task_ctx->lbr_stack_state = LBR_NONE; |
| 386 | } |
| 387 | |
| 388 | static void __intel_pmu_lbr_save(struct x86_perf_task_context *task_ctx) |
| 389 | { |
| 390 | struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); |
| 391 | unsigned lbr_idx, mask; |
| 392 | u64 tos, from; |
| 393 | int i; |
| 394 | |
| 395 | if (task_ctx->lbr_callstack_users == 0) { |
| 396 | task_ctx->lbr_stack_state = LBR_NONE; |
| 397 | return; |
| 398 | } |
| 399 | |
| 400 | mask = x86_pmu.lbr_nr - 1; |
| 401 | tos = intel_pmu_lbr_tos(); |
| 402 | for (i = 0; i < x86_pmu.lbr_nr; i++) { |
| 403 | lbr_idx = (tos - i) & mask; |
| 404 | from = rdlbr_from(lbr_idx); |
| 405 | if (!from) |
| 406 | break; |
| 407 | task_ctx->lbr_from[i] = from; |
| 408 | task_ctx->lbr_to[i] = rdlbr_to(lbr_idx); |
| 409 | if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO) |
| 410 | rdmsrl(MSR_LBR_INFO_0 + lbr_idx, task_ctx->lbr_info[i]); |
| 411 | } |
| 412 | task_ctx->valid_lbrs = i; |
| 413 | task_ctx->tos = tos; |
| 414 | task_ctx->lbr_stack_state = LBR_VALID; |
| 415 | |
| 416 | cpuc->last_task_ctx = task_ctx; |
| 417 | cpuc->last_log_id = ++task_ctx->log_id; |
| 418 | } |
| 419 | |
| 420 | void intel_pmu_lbr_sched_task(struct perf_event_context *ctx, bool sched_in) |
| 421 | { |
| 422 | struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); |
| 423 | struct x86_perf_task_context *task_ctx; |
| 424 | |
| 425 | if (!cpuc->lbr_users) |
| 426 | return; |
| 427 | |
| 428 | /* |
| 429 | * If LBR callstack feature is enabled and the stack was saved when |
| 430 | * the task was scheduled out, restore the stack. Otherwise flush |
| 431 | * the LBR stack. |
| 432 | */ |
| 433 | task_ctx = ctx ? ctx->task_ctx_data : NULL; |
| 434 | if (task_ctx) { |
| 435 | if (sched_in) |
| 436 | __intel_pmu_lbr_restore(task_ctx); |
| 437 | else |
| 438 | __intel_pmu_lbr_save(task_ctx); |
| 439 | return; |
| 440 | } |
| 441 | |
| 442 | /* |
| 443 | * Since a context switch can flip the address space and LBR entries |
| 444 | * are not tagged with an identifier, we need to wipe the LBR, even for |
| 445 | * per-cpu events. You simply cannot resolve the branches from the old |
| 446 | * address space. |
| 447 | */ |
| 448 | if (sched_in) |
| 449 | intel_pmu_lbr_reset(); |
| 450 | } |
| 451 | |
| 452 | static inline bool branch_user_callstack(unsigned br_sel) |
| 453 | { |
| 454 | return (br_sel & X86_BR_USER) && (br_sel & X86_BR_CALL_STACK); |
| 455 | } |
| 456 | |
| 457 | void intel_pmu_lbr_add(struct perf_event *event) |
| 458 | { |
| 459 | struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); |
| 460 | struct x86_perf_task_context *task_ctx; |
| 461 | |
| 462 | if (!x86_pmu.lbr_nr) |
| 463 | return; |
| 464 | |
| 465 | cpuc->br_sel = event->hw.branch_reg.reg; |
| 466 | |
| 467 | if (branch_user_callstack(cpuc->br_sel) && event->ctx->task_ctx_data) { |
| 468 | task_ctx = event->ctx->task_ctx_data; |
| 469 | task_ctx->lbr_callstack_users++; |
| 470 | } |
| 471 | |
| 472 | /* |
| 473 | * Request pmu::sched_task() callback, which will fire inside the |
| 474 | * regular perf event scheduling, so that call will: |
| 475 | * |
| 476 | * - restore or wipe; when LBR-callstack, |
| 477 | * - wipe; otherwise, |
| 478 | * |
| 479 | * when this is from __perf_event_task_sched_in(). |
| 480 | * |
| 481 | * However, if this is from perf_install_in_context(), no such callback |
| 482 | * will follow and we'll need to reset the LBR here if this is the |
| 483 | * first LBR event. |
| 484 | * |
| 485 | * The problem is, we cannot tell these cases apart... but we can |
| 486 | * exclude the biggest chunk of cases by looking at |
| 487 | * event->total_time_running. An event that has accrued runtime cannot |
| 488 | * be 'new'. Conversely, a new event can get installed through the |
| 489 | * context switch path for the first time. |
| 490 | */ |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 491 | if (x86_pmu.intel_cap.pebs_baseline && event->attr.precise_ip > 0) |
| 492 | cpuc->lbr_pebs_users++; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 493 | perf_sched_cb_inc(event->ctx->pmu); |
| 494 | if (!cpuc->lbr_users++ && !event->total_time_running) |
| 495 | intel_pmu_lbr_reset(); |
| 496 | } |
| 497 | |
| 498 | void intel_pmu_lbr_del(struct perf_event *event) |
| 499 | { |
| 500 | struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); |
| 501 | struct x86_perf_task_context *task_ctx; |
| 502 | |
| 503 | if (!x86_pmu.lbr_nr) |
| 504 | return; |
| 505 | |
| 506 | if (branch_user_callstack(cpuc->br_sel) && |
| 507 | event->ctx->task_ctx_data) { |
| 508 | task_ctx = event->ctx->task_ctx_data; |
| 509 | task_ctx->lbr_callstack_users--; |
| 510 | } |
| 511 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 512 | if (x86_pmu.intel_cap.pebs_baseline && event->attr.precise_ip > 0) |
| 513 | cpuc->lbr_pebs_users--; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 514 | cpuc->lbr_users--; |
| 515 | WARN_ON_ONCE(cpuc->lbr_users < 0); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 516 | WARN_ON_ONCE(cpuc->lbr_pebs_users < 0); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 517 | perf_sched_cb_dec(event->ctx->pmu); |
| 518 | } |
| 519 | |
| 520 | void intel_pmu_lbr_enable_all(bool pmi) |
| 521 | { |
| 522 | struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); |
| 523 | |
| 524 | if (cpuc->lbr_users) |
| 525 | __intel_pmu_lbr_enable(pmi); |
| 526 | } |
| 527 | |
| 528 | void intel_pmu_lbr_disable_all(void) |
| 529 | { |
| 530 | struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); |
| 531 | |
| 532 | if (cpuc->lbr_users) |
| 533 | __intel_pmu_lbr_disable(); |
| 534 | } |
| 535 | |
| 536 | static void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc) |
| 537 | { |
| 538 | unsigned long mask = x86_pmu.lbr_nr - 1; |
| 539 | u64 tos = intel_pmu_lbr_tos(); |
| 540 | int i; |
| 541 | |
| 542 | for (i = 0; i < x86_pmu.lbr_nr; i++) { |
| 543 | unsigned long lbr_idx = (tos - i) & mask; |
| 544 | union { |
| 545 | struct { |
| 546 | u32 from; |
| 547 | u32 to; |
| 548 | }; |
| 549 | u64 lbr; |
| 550 | } msr_lastbranch; |
| 551 | |
| 552 | rdmsrl(x86_pmu.lbr_from + lbr_idx, msr_lastbranch.lbr); |
| 553 | |
| 554 | cpuc->lbr_entries[i].from = msr_lastbranch.from; |
| 555 | cpuc->lbr_entries[i].to = msr_lastbranch.to; |
| 556 | cpuc->lbr_entries[i].mispred = 0; |
| 557 | cpuc->lbr_entries[i].predicted = 0; |
| 558 | cpuc->lbr_entries[i].in_tx = 0; |
| 559 | cpuc->lbr_entries[i].abort = 0; |
| 560 | cpuc->lbr_entries[i].cycles = 0; |
| 561 | cpuc->lbr_entries[i].type = 0; |
| 562 | cpuc->lbr_entries[i].reserved = 0; |
| 563 | } |
| 564 | cpuc->lbr_stack.nr = i; |
| 565 | } |
| 566 | |
| 567 | /* |
| 568 | * Due to lack of segmentation in Linux the effective address (offset) |
| 569 | * is the same as the linear address, allowing us to merge the LIP and EIP |
| 570 | * LBR formats. |
| 571 | */ |
| 572 | static void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc) |
| 573 | { |
| 574 | bool need_info = false, call_stack = false; |
| 575 | unsigned long mask = x86_pmu.lbr_nr - 1; |
| 576 | int lbr_format = x86_pmu.intel_cap.lbr_format; |
| 577 | u64 tos = intel_pmu_lbr_tos(); |
| 578 | int i; |
| 579 | int out = 0; |
| 580 | int num = x86_pmu.lbr_nr; |
| 581 | |
| 582 | if (cpuc->lbr_sel) { |
| 583 | need_info = !(cpuc->lbr_sel->config & LBR_NO_INFO); |
| 584 | if (cpuc->lbr_sel->config & LBR_CALL_STACK) |
| 585 | call_stack = true; |
| 586 | } |
| 587 | |
| 588 | for (i = 0; i < num; i++) { |
| 589 | unsigned long lbr_idx = (tos - i) & mask; |
| 590 | u64 from, to, mis = 0, pred = 0, in_tx = 0, abort = 0; |
| 591 | int skip = 0; |
| 592 | u16 cycles = 0; |
| 593 | int lbr_flags = lbr_desc[lbr_format]; |
| 594 | |
| 595 | from = rdlbr_from(lbr_idx); |
| 596 | to = rdlbr_to(lbr_idx); |
| 597 | |
| 598 | /* |
| 599 | * Read LBR call stack entries |
| 600 | * until invalid entry (0s) is detected. |
| 601 | */ |
| 602 | if (call_stack && !from) |
| 603 | break; |
| 604 | |
| 605 | if (lbr_format == LBR_FORMAT_INFO && need_info) { |
| 606 | u64 info; |
| 607 | |
| 608 | rdmsrl(MSR_LBR_INFO_0 + lbr_idx, info); |
| 609 | mis = !!(info & LBR_INFO_MISPRED); |
| 610 | pred = !mis; |
| 611 | in_tx = !!(info & LBR_INFO_IN_TX); |
| 612 | abort = !!(info & LBR_INFO_ABORT); |
| 613 | cycles = (info & LBR_INFO_CYCLES); |
| 614 | } |
| 615 | |
| 616 | if (lbr_format == LBR_FORMAT_TIME) { |
| 617 | mis = !!(from & LBR_FROM_FLAG_MISPRED); |
| 618 | pred = !mis; |
| 619 | skip = 1; |
| 620 | cycles = ((to >> 48) & LBR_INFO_CYCLES); |
| 621 | |
| 622 | to = (u64)((((s64)to) << 16) >> 16); |
| 623 | } |
| 624 | |
| 625 | if (lbr_flags & LBR_EIP_FLAGS) { |
| 626 | mis = !!(from & LBR_FROM_FLAG_MISPRED); |
| 627 | pred = !mis; |
| 628 | skip = 1; |
| 629 | } |
| 630 | if (lbr_flags & LBR_TSX) { |
| 631 | in_tx = !!(from & LBR_FROM_FLAG_IN_TX); |
| 632 | abort = !!(from & LBR_FROM_FLAG_ABORT); |
| 633 | skip = 3; |
| 634 | } |
| 635 | from = (u64)((((s64)from) << skip) >> skip); |
| 636 | |
| 637 | /* |
| 638 | * Some CPUs report duplicated abort records, |
| 639 | * with the second entry not having an abort bit set. |
| 640 | * Skip them here. This loop runs backwards, |
| 641 | * so we need to undo the previous record. |
| 642 | * If the abort just happened outside the window |
| 643 | * the extra entry cannot be removed. |
| 644 | */ |
| 645 | if (abort && x86_pmu.lbr_double_abort && out > 0) |
| 646 | out--; |
| 647 | |
| 648 | cpuc->lbr_entries[out].from = from; |
| 649 | cpuc->lbr_entries[out].to = to; |
| 650 | cpuc->lbr_entries[out].mispred = mis; |
| 651 | cpuc->lbr_entries[out].predicted = pred; |
| 652 | cpuc->lbr_entries[out].in_tx = in_tx; |
| 653 | cpuc->lbr_entries[out].abort = abort; |
| 654 | cpuc->lbr_entries[out].cycles = cycles; |
| 655 | cpuc->lbr_entries[out].type = 0; |
| 656 | cpuc->lbr_entries[out].reserved = 0; |
| 657 | out++; |
| 658 | } |
| 659 | cpuc->lbr_stack.nr = out; |
| 660 | } |
| 661 | |
| 662 | void intel_pmu_lbr_read(void) |
| 663 | { |
| 664 | struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); |
| 665 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 666 | /* |
| 667 | * Don't read when all LBRs users are using adaptive PEBS. |
| 668 | * |
| 669 | * This could be smarter and actually check the event, |
| 670 | * but this simple approach seems to work for now. |
| 671 | */ |
| 672 | if (!cpuc->lbr_users || cpuc->lbr_users == cpuc->lbr_pebs_users) |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 673 | return; |
| 674 | |
| 675 | if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_32) |
| 676 | intel_pmu_lbr_read_32(cpuc); |
| 677 | else |
| 678 | intel_pmu_lbr_read_64(cpuc); |
| 679 | |
| 680 | intel_pmu_lbr_filter(cpuc); |
| 681 | } |
| 682 | |
| 683 | /* |
| 684 | * SW filter is used: |
| 685 | * - in case there is no HW filter |
| 686 | * - in case the HW filter has errata or limitations |
| 687 | */ |
| 688 | static int intel_pmu_setup_sw_lbr_filter(struct perf_event *event) |
| 689 | { |
| 690 | u64 br_type = event->attr.branch_sample_type; |
| 691 | int mask = 0; |
| 692 | |
| 693 | if (br_type & PERF_SAMPLE_BRANCH_USER) |
| 694 | mask |= X86_BR_USER; |
| 695 | |
| 696 | if (br_type & PERF_SAMPLE_BRANCH_KERNEL) |
| 697 | mask |= X86_BR_KERNEL; |
| 698 | |
| 699 | /* we ignore BRANCH_HV here */ |
| 700 | |
| 701 | if (br_type & PERF_SAMPLE_BRANCH_ANY) |
| 702 | mask |= X86_BR_ANY; |
| 703 | |
| 704 | if (br_type & PERF_SAMPLE_BRANCH_ANY_CALL) |
| 705 | mask |= X86_BR_ANY_CALL; |
| 706 | |
| 707 | if (br_type & PERF_SAMPLE_BRANCH_ANY_RETURN) |
| 708 | mask |= X86_BR_RET | X86_BR_IRET | X86_BR_SYSRET; |
| 709 | |
| 710 | if (br_type & PERF_SAMPLE_BRANCH_IND_CALL) |
| 711 | mask |= X86_BR_IND_CALL; |
| 712 | |
| 713 | if (br_type & PERF_SAMPLE_BRANCH_ABORT_TX) |
| 714 | mask |= X86_BR_ABORT; |
| 715 | |
| 716 | if (br_type & PERF_SAMPLE_BRANCH_IN_TX) |
| 717 | mask |= X86_BR_IN_TX; |
| 718 | |
| 719 | if (br_type & PERF_SAMPLE_BRANCH_NO_TX) |
| 720 | mask |= X86_BR_NO_TX; |
| 721 | |
| 722 | if (br_type & PERF_SAMPLE_BRANCH_COND) |
| 723 | mask |= X86_BR_JCC; |
| 724 | |
| 725 | if (br_type & PERF_SAMPLE_BRANCH_CALL_STACK) { |
| 726 | if (!x86_pmu_has_lbr_callstack()) |
| 727 | return -EOPNOTSUPP; |
| 728 | if (mask & ~(X86_BR_USER | X86_BR_KERNEL)) |
| 729 | return -EINVAL; |
| 730 | mask |= X86_BR_CALL | X86_BR_IND_CALL | X86_BR_RET | |
| 731 | X86_BR_CALL_STACK; |
| 732 | } |
| 733 | |
| 734 | if (br_type & PERF_SAMPLE_BRANCH_IND_JUMP) |
| 735 | mask |= X86_BR_IND_JMP; |
| 736 | |
| 737 | if (br_type & PERF_SAMPLE_BRANCH_CALL) |
| 738 | mask |= X86_BR_CALL | X86_BR_ZERO_CALL; |
| 739 | |
| 740 | if (br_type & PERF_SAMPLE_BRANCH_TYPE_SAVE) |
| 741 | mask |= X86_BR_TYPE_SAVE; |
| 742 | |
| 743 | /* |
| 744 | * stash actual user request into reg, it may |
| 745 | * be used by fixup code for some CPU |
| 746 | */ |
| 747 | event->hw.branch_reg.reg = mask; |
| 748 | return 0; |
| 749 | } |
| 750 | |
| 751 | /* |
| 752 | * setup the HW LBR filter |
| 753 | * Used only when available, may not be enough to disambiguate |
| 754 | * all branches, may need the help of the SW filter |
| 755 | */ |
| 756 | static int intel_pmu_setup_hw_lbr_filter(struct perf_event *event) |
| 757 | { |
| 758 | struct hw_perf_event_extra *reg; |
| 759 | u64 br_type = event->attr.branch_sample_type; |
| 760 | u64 mask = 0, v; |
| 761 | int i; |
| 762 | |
| 763 | for (i = 0; i < PERF_SAMPLE_BRANCH_MAX_SHIFT; i++) { |
| 764 | if (!(br_type & (1ULL << i))) |
| 765 | continue; |
| 766 | |
| 767 | v = x86_pmu.lbr_sel_map[i]; |
| 768 | if (v == LBR_NOT_SUPP) |
| 769 | return -EOPNOTSUPP; |
| 770 | |
| 771 | if (v != LBR_IGN) |
| 772 | mask |= v; |
| 773 | } |
| 774 | |
| 775 | reg = &event->hw.branch_reg; |
| 776 | reg->idx = EXTRA_REG_LBR; |
| 777 | |
| 778 | /* |
| 779 | * The first 9 bits (LBR_SEL_MASK) in LBR_SELECT operate |
| 780 | * in suppress mode. So LBR_SELECT should be set to |
| 781 | * (~mask & LBR_SEL_MASK) | (mask & ~LBR_SEL_MASK) |
| 782 | * But the 10th bit LBR_CALL_STACK does not operate |
| 783 | * in suppress mode. |
| 784 | */ |
| 785 | reg->config = mask ^ (x86_pmu.lbr_sel_mask & ~LBR_CALL_STACK); |
| 786 | |
| 787 | if ((br_type & PERF_SAMPLE_BRANCH_NO_CYCLES) && |
| 788 | (br_type & PERF_SAMPLE_BRANCH_NO_FLAGS) && |
| 789 | (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO)) |
| 790 | reg->config |= LBR_NO_INFO; |
| 791 | |
| 792 | return 0; |
| 793 | } |
| 794 | |
| 795 | int intel_pmu_setup_lbr_filter(struct perf_event *event) |
| 796 | { |
| 797 | int ret = 0; |
| 798 | |
| 799 | /* |
| 800 | * no LBR on this PMU |
| 801 | */ |
| 802 | if (!x86_pmu.lbr_nr) |
| 803 | return -EOPNOTSUPP; |
| 804 | |
| 805 | /* |
| 806 | * setup SW LBR filter |
| 807 | */ |
| 808 | ret = intel_pmu_setup_sw_lbr_filter(event); |
| 809 | if (ret) |
| 810 | return ret; |
| 811 | |
| 812 | /* |
| 813 | * setup HW LBR filter, if any |
| 814 | */ |
| 815 | if (x86_pmu.lbr_sel_map) |
| 816 | ret = intel_pmu_setup_hw_lbr_filter(event); |
| 817 | |
| 818 | return ret; |
| 819 | } |
| 820 | |
| 821 | /* |
| 822 | * return the type of control flow change at address "from" |
| 823 | * instruction is not necessarily a branch (in case of interrupt). |
| 824 | * |
| 825 | * The branch type returned also includes the priv level of the |
| 826 | * target of the control flow change (X86_BR_USER, X86_BR_KERNEL). |
| 827 | * |
| 828 | * If a branch type is unknown OR the instruction cannot be |
| 829 | * decoded (e.g., text page not present), then X86_BR_NONE is |
| 830 | * returned. |
| 831 | */ |
| 832 | static int branch_type(unsigned long from, unsigned long to, int abort) |
| 833 | { |
| 834 | struct insn insn; |
| 835 | void *addr; |
| 836 | int bytes_read, bytes_left; |
| 837 | int ret = X86_BR_NONE; |
| 838 | int ext, to_plm, from_plm; |
| 839 | u8 buf[MAX_INSN_SIZE]; |
| 840 | int is64 = 0; |
| 841 | |
| 842 | to_plm = kernel_ip(to) ? X86_BR_KERNEL : X86_BR_USER; |
| 843 | from_plm = kernel_ip(from) ? X86_BR_KERNEL : X86_BR_USER; |
| 844 | |
| 845 | /* |
| 846 | * maybe zero if lbr did not fill up after a reset by the time |
| 847 | * we get a PMU interrupt |
| 848 | */ |
| 849 | if (from == 0 || to == 0) |
| 850 | return X86_BR_NONE; |
| 851 | |
| 852 | if (abort) |
| 853 | return X86_BR_ABORT | to_plm; |
| 854 | |
| 855 | if (from_plm == X86_BR_USER) { |
| 856 | /* |
| 857 | * can happen if measuring at the user level only |
| 858 | * and we interrupt in a kernel thread, e.g., idle. |
| 859 | */ |
| 860 | if (!current->mm) |
| 861 | return X86_BR_NONE; |
| 862 | |
| 863 | /* may fail if text not present */ |
| 864 | bytes_left = copy_from_user_nmi(buf, (void __user *)from, |
| 865 | MAX_INSN_SIZE); |
| 866 | bytes_read = MAX_INSN_SIZE - bytes_left; |
| 867 | if (!bytes_read) |
| 868 | return X86_BR_NONE; |
| 869 | |
| 870 | addr = buf; |
| 871 | } else { |
| 872 | /* |
| 873 | * The LBR logs any address in the IP, even if the IP just |
| 874 | * faulted. This means userspace can control the from address. |
| 875 | * Ensure we don't blindy read any address by validating it is |
| 876 | * a known text address. |
| 877 | */ |
| 878 | if (kernel_text_address(from)) { |
| 879 | addr = (void *)from; |
| 880 | /* |
| 881 | * Assume we can get the maximum possible size |
| 882 | * when grabbing kernel data. This is not |
| 883 | * _strictly_ true since we could possibly be |
| 884 | * executing up next to a memory hole, but |
| 885 | * it is very unlikely to be a problem. |
| 886 | */ |
| 887 | bytes_read = MAX_INSN_SIZE; |
| 888 | } else { |
| 889 | return X86_BR_NONE; |
| 890 | } |
| 891 | } |
| 892 | |
| 893 | /* |
| 894 | * decoder needs to know the ABI especially |
| 895 | * on 64-bit systems running 32-bit apps |
| 896 | */ |
| 897 | #ifdef CONFIG_X86_64 |
| 898 | is64 = kernel_ip((unsigned long)addr) || !test_thread_flag(TIF_IA32); |
| 899 | #endif |
| 900 | insn_init(&insn, addr, bytes_read, is64); |
| 901 | insn_get_opcode(&insn); |
| 902 | if (!insn.opcode.got) |
| 903 | return X86_BR_ABORT; |
| 904 | |
| 905 | switch (insn.opcode.bytes[0]) { |
| 906 | case 0xf: |
| 907 | switch (insn.opcode.bytes[1]) { |
| 908 | case 0x05: /* syscall */ |
| 909 | case 0x34: /* sysenter */ |
| 910 | ret = X86_BR_SYSCALL; |
| 911 | break; |
| 912 | case 0x07: /* sysret */ |
| 913 | case 0x35: /* sysexit */ |
| 914 | ret = X86_BR_SYSRET; |
| 915 | break; |
| 916 | case 0x80 ... 0x8f: /* conditional */ |
| 917 | ret = X86_BR_JCC; |
| 918 | break; |
| 919 | default: |
| 920 | ret = X86_BR_NONE; |
| 921 | } |
| 922 | break; |
| 923 | case 0x70 ... 0x7f: /* conditional */ |
| 924 | ret = X86_BR_JCC; |
| 925 | break; |
| 926 | case 0xc2: /* near ret */ |
| 927 | case 0xc3: /* near ret */ |
| 928 | case 0xca: /* far ret */ |
| 929 | case 0xcb: /* far ret */ |
| 930 | ret = X86_BR_RET; |
| 931 | break; |
| 932 | case 0xcf: /* iret */ |
| 933 | ret = X86_BR_IRET; |
| 934 | break; |
| 935 | case 0xcc ... 0xce: /* int */ |
| 936 | ret = X86_BR_INT; |
| 937 | break; |
| 938 | case 0xe8: /* call near rel */ |
| 939 | insn_get_immediate(&insn); |
| 940 | if (insn.immediate1.value == 0) { |
| 941 | /* zero length call */ |
| 942 | ret = X86_BR_ZERO_CALL; |
| 943 | break; |
| 944 | } |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 945 | /* fall through */ |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 946 | case 0x9a: /* call far absolute */ |
| 947 | ret = X86_BR_CALL; |
| 948 | break; |
| 949 | case 0xe0 ... 0xe3: /* loop jmp */ |
| 950 | ret = X86_BR_JCC; |
| 951 | break; |
| 952 | case 0xe9 ... 0xeb: /* jmp */ |
| 953 | ret = X86_BR_JMP; |
| 954 | break; |
| 955 | case 0xff: /* call near absolute, call far absolute ind */ |
| 956 | insn_get_modrm(&insn); |
| 957 | ext = (insn.modrm.bytes[0] >> 3) & 0x7; |
| 958 | switch (ext) { |
| 959 | case 2: /* near ind call */ |
| 960 | case 3: /* far ind call */ |
| 961 | ret = X86_BR_IND_CALL; |
| 962 | break; |
| 963 | case 4: |
| 964 | case 5: |
| 965 | ret = X86_BR_IND_JMP; |
| 966 | break; |
| 967 | } |
| 968 | break; |
| 969 | default: |
| 970 | ret = X86_BR_NONE; |
| 971 | } |
| 972 | /* |
| 973 | * interrupts, traps, faults (and thus ring transition) may |
| 974 | * occur on any instructions. Thus, to classify them correctly, |
| 975 | * we need to first look at the from and to priv levels. If they |
| 976 | * are different and to is in the kernel, then it indicates |
| 977 | * a ring transition. If the from instruction is not a ring |
| 978 | * transition instr (syscall, systenter, int), then it means |
| 979 | * it was a irq, trap or fault. |
| 980 | * |
| 981 | * we have no way of detecting kernel to kernel faults. |
| 982 | */ |
| 983 | if (from_plm == X86_BR_USER && to_plm == X86_BR_KERNEL |
| 984 | && ret != X86_BR_SYSCALL && ret != X86_BR_INT) |
| 985 | ret = X86_BR_IRQ; |
| 986 | |
| 987 | /* |
| 988 | * branch priv level determined by target as |
| 989 | * is done by HW when LBR_SELECT is implemented |
| 990 | */ |
| 991 | if (ret != X86_BR_NONE) |
| 992 | ret |= to_plm; |
| 993 | |
| 994 | return ret; |
| 995 | } |
| 996 | |
| 997 | #define X86_BR_TYPE_MAP_MAX 16 |
| 998 | |
| 999 | static int branch_map[X86_BR_TYPE_MAP_MAX] = { |
| 1000 | PERF_BR_CALL, /* X86_BR_CALL */ |
| 1001 | PERF_BR_RET, /* X86_BR_RET */ |
| 1002 | PERF_BR_SYSCALL, /* X86_BR_SYSCALL */ |
| 1003 | PERF_BR_SYSRET, /* X86_BR_SYSRET */ |
| 1004 | PERF_BR_UNKNOWN, /* X86_BR_INT */ |
| 1005 | PERF_BR_UNKNOWN, /* X86_BR_IRET */ |
| 1006 | PERF_BR_COND, /* X86_BR_JCC */ |
| 1007 | PERF_BR_UNCOND, /* X86_BR_JMP */ |
| 1008 | PERF_BR_UNKNOWN, /* X86_BR_IRQ */ |
| 1009 | PERF_BR_IND_CALL, /* X86_BR_IND_CALL */ |
| 1010 | PERF_BR_UNKNOWN, /* X86_BR_ABORT */ |
| 1011 | PERF_BR_UNKNOWN, /* X86_BR_IN_TX */ |
| 1012 | PERF_BR_UNKNOWN, /* X86_BR_NO_TX */ |
| 1013 | PERF_BR_CALL, /* X86_BR_ZERO_CALL */ |
| 1014 | PERF_BR_UNKNOWN, /* X86_BR_CALL_STACK */ |
| 1015 | PERF_BR_IND, /* X86_BR_IND_JMP */ |
| 1016 | }; |
| 1017 | |
| 1018 | static int |
| 1019 | common_branch_type(int type) |
| 1020 | { |
| 1021 | int i; |
| 1022 | |
| 1023 | type >>= 2; /* skip X86_BR_USER and X86_BR_KERNEL */ |
| 1024 | |
| 1025 | if (type) { |
| 1026 | i = __ffs(type); |
| 1027 | if (i < X86_BR_TYPE_MAP_MAX) |
| 1028 | return branch_map[i]; |
| 1029 | } |
| 1030 | |
| 1031 | return PERF_BR_UNKNOWN; |
| 1032 | } |
| 1033 | |
| 1034 | /* |
| 1035 | * implement actual branch filter based on user demand. |
| 1036 | * Hardware may not exactly satisfy that request, thus |
| 1037 | * we need to inspect opcodes. Mismatched branches are |
| 1038 | * discarded. Therefore, the number of branches returned |
| 1039 | * in PERF_SAMPLE_BRANCH_STACK sample may vary. |
| 1040 | */ |
| 1041 | static void |
| 1042 | intel_pmu_lbr_filter(struct cpu_hw_events *cpuc) |
| 1043 | { |
| 1044 | u64 from, to; |
| 1045 | int br_sel = cpuc->br_sel; |
| 1046 | int i, j, type; |
| 1047 | bool compress = false; |
| 1048 | |
| 1049 | /* if sampling all branches, then nothing to filter */ |
| 1050 | if (((br_sel & X86_BR_ALL) == X86_BR_ALL) && |
| 1051 | ((br_sel & X86_BR_TYPE_SAVE) != X86_BR_TYPE_SAVE)) |
| 1052 | return; |
| 1053 | |
| 1054 | for (i = 0; i < cpuc->lbr_stack.nr; i++) { |
| 1055 | |
| 1056 | from = cpuc->lbr_entries[i].from; |
| 1057 | to = cpuc->lbr_entries[i].to; |
| 1058 | |
| 1059 | type = branch_type(from, to, cpuc->lbr_entries[i].abort); |
| 1060 | if (type != X86_BR_NONE && (br_sel & X86_BR_ANYTX)) { |
| 1061 | if (cpuc->lbr_entries[i].in_tx) |
| 1062 | type |= X86_BR_IN_TX; |
| 1063 | else |
| 1064 | type |= X86_BR_NO_TX; |
| 1065 | } |
| 1066 | |
| 1067 | /* if type does not correspond, then discard */ |
| 1068 | if (type == X86_BR_NONE || (br_sel & type) != type) { |
| 1069 | cpuc->lbr_entries[i].from = 0; |
| 1070 | compress = true; |
| 1071 | } |
| 1072 | |
| 1073 | if ((br_sel & X86_BR_TYPE_SAVE) == X86_BR_TYPE_SAVE) |
| 1074 | cpuc->lbr_entries[i].type = common_branch_type(type); |
| 1075 | } |
| 1076 | |
| 1077 | if (!compress) |
| 1078 | return; |
| 1079 | |
| 1080 | /* remove all entries with from=0 */ |
| 1081 | for (i = 0; i < cpuc->lbr_stack.nr; ) { |
| 1082 | if (!cpuc->lbr_entries[i].from) { |
| 1083 | j = i; |
| 1084 | while (++j < cpuc->lbr_stack.nr) |
| 1085 | cpuc->lbr_entries[j-1] = cpuc->lbr_entries[j]; |
| 1086 | cpuc->lbr_stack.nr--; |
| 1087 | if (!cpuc->lbr_entries[i].from) |
| 1088 | continue; |
| 1089 | } |
| 1090 | i++; |
| 1091 | } |
| 1092 | } |
| 1093 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 1094 | void intel_pmu_store_pebs_lbrs(struct pebs_lbr *lbr) |
| 1095 | { |
| 1096 | struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); |
| 1097 | int i; |
| 1098 | |
| 1099 | cpuc->lbr_stack.nr = x86_pmu.lbr_nr; |
| 1100 | for (i = 0; i < x86_pmu.lbr_nr; i++) { |
| 1101 | u64 info = lbr->lbr[i].info; |
| 1102 | struct perf_branch_entry *e = &cpuc->lbr_entries[i]; |
| 1103 | |
| 1104 | e->from = lbr->lbr[i].from; |
| 1105 | e->to = lbr->lbr[i].to; |
| 1106 | e->mispred = !!(info & LBR_INFO_MISPRED); |
| 1107 | e->predicted = !(info & LBR_INFO_MISPRED); |
| 1108 | e->in_tx = !!(info & LBR_INFO_IN_TX); |
| 1109 | e->abort = !!(info & LBR_INFO_ABORT); |
| 1110 | e->cycles = info & LBR_INFO_CYCLES; |
| 1111 | e->reserved = 0; |
| 1112 | } |
| 1113 | intel_pmu_lbr_filter(cpuc); |
| 1114 | } |
| 1115 | |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1116 | /* |
| 1117 | * Map interface branch filters onto LBR filters |
| 1118 | */ |
| 1119 | static const int nhm_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = { |
| 1120 | [PERF_SAMPLE_BRANCH_ANY_SHIFT] = LBR_ANY, |
| 1121 | [PERF_SAMPLE_BRANCH_USER_SHIFT] = LBR_USER, |
| 1122 | [PERF_SAMPLE_BRANCH_KERNEL_SHIFT] = LBR_KERNEL, |
| 1123 | [PERF_SAMPLE_BRANCH_HV_SHIFT] = LBR_IGN, |
| 1124 | [PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT] = LBR_RETURN | LBR_REL_JMP |
| 1125 | | LBR_IND_JMP | LBR_FAR, |
| 1126 | /* |
| 1127 | * NHM/WSM erratum: must include REL_JMP+IND_JMP to get CALL branches |
| 1128 | */ |
| 1129 | [PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT] = |
| 1130 | LBR_REL_CALL | LBR_IND_CALL | LBR_REL_JMP | LBR_IND_JMP | LBR_FAR, |
| 1131 | /* |
| 1132 | * NHM/WSM erratum: must include IND_JMP to capture IND_CALL |
| 1133 | */ |
| 1134 | [PERF_SAMPLE_BRANCH_IND_CALL_SHIFT] = LBR_IND_CALL | LBR_IND_JMP, |
| 1135 | [PERF_SAMPLE_BRANCH_COND_SHIFT] = LBR_JCC, |
| 1136 | [PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT] = LBR_IND_JMP, |
| 1137 | }; |
| 1138 | |
| 1139 | static const int snb_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = { |
| 1140 | [PERF_SAMPLE_BRANCH_ANY_SHIFT] = LBR_ANY, |
| 1141 | [PERF_SAMPLE_BRANCH_USER_SHIFT] = LBR_USER, |
| 1142 | [PERF_SAMPLE_BRANCH_KERNEL_SHIFT] = LBR_KERNEL, |
| 1143 | [PERF_SAMPLE_BRANCH_HV_SHIFT] = LBR_IGN, |
| 1144 | [PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT] = LBR_RETURN | LBR_FAR, |
| 1145 | [PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT] = LBR_REL_CALL | LBR_IND_CALL |
| 1146 | | LBR_FAR, |
| 1147 | [PERF_SAMPLE_BRANCH_IND_CALL_SHIFT] = LBR_IND_CALL, |
| 1148 | [PERF_SAMPLE_BRANCH_COND_SHIFT] = LBR_JCC, |
| 1149 | [PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT] = LBR_IND_JMP, |
| 1150 | [PERF_SAMPLE_BRANCH_CALL_SHIFT] = LBR_REL_CALL, |
| 1151 | }; |
| 1152 | |
| 1153 | static const int hsw_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = { |
| 1154 | [PERF_SAMPLE_BRANCH_ANY_SHIFT] = LBR_ANY, |
| 1155 | [PERF_SAMPLE_BRANCH_USER_SHIFT] = LBR_USER, |
| 1156 | [PERF_SAMPLE_BRANCH_KERNEL_SHIFT] = LBR_KERNEL, |
| 1157 | [PERF_SAMPLE_BRANCH_HV_SHIFT] = LBR_IGN, |
| 1158 | [PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT] = LBR_RETURN | LBR_FAR, |
| 1159 | [PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT] = LBR_REL_CALL | LBR_IND_CALL |
| 1160 | | LBR_FAR, |
| 1161 | [PERF_SAMPLE_BRANCH_IND_CALL_SHIFT] = LBR_IND_CALL, |
| 1162 | [PERF_SAMPLE_BRANCH_COND_SHIFT] = LBR_JCC, |
| 1163 | [PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT] = LBR_REL_CALL | LBR_IND_CALL |
| 1164 | | LBR_RETURN | LBR_CALL_STACK, |
| 1165 | [PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT] = LBR_IND_JMP, |
| 1166 | [PERF_SAMPLE_BRANCH_CALL_SHIFT] = LBR_REL_CALL, |
| 1167 | }; |
| 1168 | |
| 1169 | /* core */ |
| 1170 | void __init intel_pmu_lbr_init_core(void) |
| 1171 | { |
| 1172 | x86_pmu.lbr_nr = 4; |
| 1173 | x86_pmu.lbr_tos = MSR_LBR_TOS; |
| 1174 | x86_pmu.lbr_from = MSR_LBR_CORE_FROM; |
| 1175 | x86_pmu.lbr_to = MSR_LBR_CORE_TO; |
| 1176 | |
| 1177 | /* |
| 1178 | * SW branch filter usage: |
| 1179 | * - compensate for lack of HW filter |
| 1180 | */ |
| 1181 | } |
| 1182 | |
| 1183 | /* nehalem/westmere */ |
| 1184 | void __init intel_pmu_lbr_init_nhm(void) |
| 1185 | { |
| 1186 | x86_pmu.lbr_nr = 16; |
| 1187 | x86_pmu.lbr_tos = MSR_LBR_TOS; |
| 1188 | x86_pmu.lbr_from = MSR_LBR_NHM_FROM; |
| 1189 | x86_pmu.lbr_to = MSR_LBR_NHM_TO; |
| 1190 | |
| 1191 | x86_pmu.lbr_sel_mask = LBR_SEL_MASK; |
| 1192 | x86_pmu.lbr_sel_map = nhm_lbr_sel_map; |
| 1193 | |
| 1194 | /* |
| 1195 | * SW branch filter usage: |
| 1196 | * - workaround LBR_SEL errata (see above) |
| 1197 | * - support syscall, sysret capture. |
| 1198 | * That requires LBR_FAR but that means far |
| 1199 | * jmp need to be filtered out |
| 1200 | */ |
| 1201 | } |
| 1202 | |
| 1203 | /* sandy bridge */ |
| 1204 | void __init intel_pmu_lbr_init_snb(void) |
| 1205 | { |
| 1206 | x86_pmu.lbr_nr = 16; |
| 1207 | x86_pmu.lbr_tos = MSR_LBR_TOS; |
| 1208 | x86_pmu.lbr_from = MSR_LBR_NHM_FROM; |
| 1209 | x86_pmu.lbr_to = MSR_LBR_NHM_TO; |
| 1210 | |
| 1211 | x86_pmu.lbr_sel_mask = LBR_SEL_MASK; |
| 1212 | x86_pmu.lbr_sel_map = snb_lbr_sel_map; |
| 1213 | |
| 1214 | /* |
| 1215 | * SW branch filter usage: |
| 1216 | * - support syscall, sysret capture. |
| 1217 | * That requires LBR_FAR but that means far |
| 1218 | * jmp need to be filtered out |
| 1219 | */ |
| 1220 | } |
| 1221 | |
| 1222 | /* haswell */ |
| 1223 | void intel_pmu_lbr_init_hsw(void) |
| 1224 | { |
| 1225 | x86_pmu.lbr_nr = 16; |
| 1226 | x86_pmu.lbr_tos = MSR_LBR_TOS; |
| 1227 | x86_pmu.lbr_from = MSR_LBR_NHM_FROM; |
| 1228 | x86_pmu.lbr_to = MSR_LBR_NHM_TO; |
| 1229 | |
| 1230 | x86_pmu.lbr_sel_mask = LBR_SEL_MASK; |
| 1231 | x86_pmu.lbr_sel_map = hsw_lbr_sel_map; |
| 1232 | |
| 1233 | if (lbr_from_signext_quirk_needed()) |
| 1234 | static_branch_enable(&lbr_from_quirk_key); |
| 1235 | } |
| 1236 | |
| 1237 | /* skylake */ |
| 1238 | __init void intel_pmu_lbr_init_skl(void) |
| 1239 | { |
| 1240 | x86_pmu.lbr_nr = 32; |
| 1241 | x86_pmu.lbr_tos = MSR_LBR_TOS; |
| 1242 | x86_pmu.lbr_from = MSR_LBR_NHM_FROM; |
| 1243 | x86_pmu.lbr_to = MSR_LBR_NHM_TO; |
| 1244 | |
| 1245 | x86_pmu.lbr_sel_mask = LBR_SEL_MASK; |
| 1246 | x86_pmu.lbr_sel_map = hsw_lbr_sel_map; |
| 1247 | |
| 1248 | /* |
| 1249 | * SW branch filter usage: |
| 1250 | * - support syscall, sysret capture. |
| 1251 | * That requires LBR_FAR but that means far |
| 1252 | * jmp need to be filtered out |
| 1253 | */ |
| 1254 | } |
| 1255 | |
| 1256 | /* atom */ |
| 1257 | void __init intel_pmu_lbr_init_atom(void) |
| 1258 | { |
| 1259 | /* |
| 1260 | * only models starting at stepping 10 seems |
| 1261 | * to have an operational LBR which can freeze |
| 1262 | * on PMU interrupt |
| 1263 | */ |
| 1264 | if (boot_cpu_data.x86_model == 28 |
| 1265 | && boot_cpu_data.x86_stepping < 10) { |
| 1266 | pr_cont("LBR disabled due to erratum"); |
| 1267 | return; |
| 1268 | } |
| 1269 | |
| 1270 | x86_pmu.lbr_nr = 8; |
| 1271 | x86_pmu.lbr_tos = MSR_LBR_TOS; |
| 1272 | x86_pmu.lbr_from = MSR_LBR_CORE_FROM; |
| 1273 | x86_pmu.lbr_to = MSR_LBR_CORE_TO; |
| 1274 | |
| 1275 | /* |
| 1276 | * SW branch filter usage: |
| 1277 | * - compensate for lack of HW filter |
| 1278 | */ |
| 1279 | } |
| 1280 | |
| 1281 | /* slm */ |
| 1282 | void __init intel_pmu_lbr_init_slm(void) |
| 1283 | { |
| 1284 | x86_pmu.lbr_nr = 8; |
| 1285 | x86_pmu.lbr_tos = MSR_LBR_TOS; |
| 1286 | x86_pmu.lbr_from = MSR_LBR_CORE_FROM; |
| 1287 | x86_pmu.lbr_to = MSR_LBR_CORE_TO; |
| 1288 | |
| 1289 | x86_pmu.lbr_sel_mask = LBR_SEL_MASK; |
| 1290 | x86_pmu.lbr_sel_map = nhm_lbr_sel_map; |
| 1291 | |
| 1292 | /* |
| 1293 | * SW branch filter usage: |
| 1294 | * - compensate for lack of HW filter |
| 1295 | */ |
| 1296 | pr_cont("8-deep LBR, "); |
| 1297 | } |
| 1298 | |
| 1299 | /* Knights Landing */ |
| 1300 | void intel_pmu_lbr_init_knl(void) |
| 1301 | { |
| 1302 | x86_pmu.lbr_nr = 8; |
| 1303 | x86_pmu.lbr_tos = MSR_LBR_TOS; |
| 1304 | x86_pmu.lbr_from = MSR_LBR_NHM_FROM; |
| 1305 | x86_pmu.lbr_to = MSR_LBR_NHM_TO; |
| 1306 | |
| 1307 | x86_pmu.lbr_sel_mask = LBR_SEL_MASK; |
| 1308 | x86_pmu.lbr_sel_map = snb_lbr_sel_map; |
| 1309 | |
| 1310 | /* Knights Landing does have MISPREDICT bit */ |
| 1311 | if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_LIP) |
| 1312 | x86_pmu.intel_cap.lbr_format = LBR_FORMAT_EIP_FLAGS; |
| 1313 | } |