diff options
Diffstat (limited to 'arch/x86/kernel/cpu/perf_event_intel_lbr.c')
-rw-r--r-- | arch/x86/kernel/cpu/perf_event_intel_lbr.c | 321 |
1 files changed, 249 insertions, 72 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c index 58f1a94beaf0..94e5b506caa6 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c +++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c @@ -39,6 +39,7 @@ static enum { #define LBR_IND_JMP_BIT 6 /* do not capture indirect jumps */ #define LBR_REL_JMP_BIT 7 /* do not capture relative jumps */ #define LBR_FAR_BIT 8 /* do not capture far branches */ +#define LBR_CALL_STACK_BIT 9 /* enable call stack */ #define LBR_KERNEL (1 << LBR_KERNEL_BIT) #define LBR_USER (1 << LBR_USER_BIT) @@ -49,6 +50,7 @@ static enum { #define LBR_REL_JMP (1 << LBR_REL_JMP_BIT) #define LBR_IND_JMP (1 << LBR_IND_JMP_BIT) #define LBR_FAR (1 << LBR_FAR_BIT) +#define LBR_CALL_STACK (1 << LBR_CALL_STACK_BIT) #define LBR_PLM (LBR_KERNEL | LBR_USER) @@ -69,33 +71,31 @@ static enum { #define LBR_FROM_FLAG_IN_TX (1ULL << 62) #define LBR_FROM_FLAG_ABORT (1ULL << 61) -#define for_each_branch_sample_type(x) \ - for ((x) = PERF_SAMPLE_BRANCH_USER; \ - (x) < PERF_SAMPLE_BRANCH_MAX; (x) <<= 1) - /* * x86control flow change classification * x86control flow changes include branches, interrupts, traps, faults */ enum { - X86_BR_NONE = 0, /* unknown */ - - X86_BR_USER = 1 << 0, /* branch target is user */ - X86_BR_KERNEL = 1 << 1, /* branch target is kernel */ - - X86_BR_CALL = 1 << 2, /* call */ - X86_BR_RET = 1 << 3, /* return */ - X86_BR_SYSCALL = 1 << 4, /* syscall */ - X86_BR_SYSRET = 1 << 5, /* syscall return */ - X86_BR_INT = 1 << 6, /* sw interrupt */ - X86_BR_IRET = 1 << 7, /* return from interrupt */ - X86_BR_JCC = 1 << 8, /* conditional */ - X86_BR_JMP = 1 << 9, /* jump */ - X86_BR_IRQ = 1 << 10,/* hw interrupt or trap or fault */ - X86_BR_IND_CALL = 1 << 11,/* indirect calls */ - X86_BR_ABORT = 1 << 12,/* transaction abort */ - X86_BR_IN_TX = 1 << 13,/* in transaction */ - X86_BR_NO_TX = 1 << 14,/* not in transaction */ + X86_BR_NONE = 0, /* unknown */ + + X86_BR_USER = 1 << 0, /* branch target is user */ + X86_BR_KERNEL = 1 << 1, /* branch target is kernel */ + + X86_BR_CALL = 1 << 2, /* call */ + X86_BR_RET = 1 << 3, /* return */ + X86_BR_SYSCALL = 1 << 4, /* syscall */ + X86_BR_SYSRET = 1 << 5, /* syscall return */ + X86_BR_INT = 1 << 6, /* sw interrupt */ + X86_BR_IRET = 1 << 7, /* return from interrupt */ + X86_BR_JCC = 1 << 8, /* conditional */ + X86_BR_JMP = 1 << 9, /* jump */ + X86_BR_IRQ = 1 << 10,/* hw interrupt or trap or fault */ + X86_BR_IND_CALL = 1 << 11,/* indirect calls */ + X86_BR_ABORT = 1 << 12,/* transaction abort */ + X86_BR_IN_TX = 1 << 13,/* in transaction */ + X86_BR_NO_TX = 1 << 14,/* not in transaction */ + X86_BR_ZERO_CALL = 1 << 15,/* zero length call */ + X86_BR_CALL_STACK = 1 << 16,/* call stack */ }; #define X86_BR_PLM (X86_BR_USER | X86_BR_KERNEL) @@ -112,13 +112,15 @@ enum { X86_BR_JMP |\ X86_BR_IRQ |\ X86_BR_ABORT |\ - X86_BR_IND_CALL) + X86_BR_IND_CALL |\ + X86_BR_ZERO_CALL) #define X86_BR_ALL (X86_BR_PLM | X86_BR_ANY) #define X86_BR_ANY_CALL \ (X86_BR_CALL |\ X86_BR_IND_CALL |\ + X86_BR_ZERO_CALL |\ X86_BR_SYSCALL |\ X86_BR_IRQ |\ X86_BR_INT) @@ -130,17 +132,32 @@ static void intel_pmu_lbr_filter(struct cpu_hw_events *cpuc); * otherwise it becomes near impossible to get a reliable stack. */ -static void __intel_pmu_lbr_enable(void) +static void __intel_pmu_lbr_enable(bool pmi) { - u64 debugctl; struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); + u64 debugctl, lbr_select = 0, orig_debugctl; - if (cpuc->lbr_sel) - wrmsrl(MSR_LBR_SELECT, cpuc->lbr_sel->config); + /* + * No need to reprogram LBR_SELECT in a PMI, as it + * did not change. + */ + if (cpuc->lbr_sel && !pmi) { + lbr_select = cpuc->lbr_sel->config; + wrmsrl(MSR_LBR_SELECT, lbr_select); + } rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); - debugctl |= (DEBUGCTLMSR_LBR | DEBUGCTLMSR_FREEZE_LBRS_ON_PMI); - wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); + orig_debugctl = debugctl; + debugctl |= DEBUGCTLMSR_LBR; + /* + * LBR callstack does not work well with FREEZE_LBRS_ON_PMI. + * If FREEZE_LBRS_ON_PMI is set, PMI near call/return instructions + * may cause superfluous increase/decrease of LBR_TOS. + */ + if (!(lbr_select & LBR_CALL_STACK)) + debugctl |= DEBUGCTLMSR_FREEZE_LBRS_ON_PMI; + if (orig_debugctl != debugctl) + wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); } static void __intel_pmu_lbr_disable(void) @@ -181,9 +198,116 @@ void intel_pmu_lbr_reset(void) intel_pmu_lbr_reset_64(); } +/* + * TOS = most recently recorded branch + */ +static inline u64 intel_pmu_lbr_tos(void) +{ + u64 tos; + + rdmsrl(x86_pmu.lbr_tos, tos); + return tos; +} + +enum { + LBR_NONE, + LBR_VALID, +}; + +static void __intel_pmu_lbr_restore(struct x86_perf_task_context *task_ctx) +{ + int i; + unsigned lbr_idx, mask; + u64 tos; + + if (task_ctx->lbr_callstack_users == 0 || + task_ctx->lbr_stack_state == LBR_NONE) { + intel_pmu_lbr_reset(); + return; + } + + mask = x86_pmu.lbr_nr - 1; + tos = intel_pmu_lbr_tos(); + for (i = 0; i < x86_pmu.lbr_nr; i++) { + lbr_idx = (tos - i) & mask; + wrmsrl(x86_pmu.lbr_from + lbr_idx, task_ctx->lbr_from[i]); + wrmsrl(x86_pmu.lbr_to + lbr_idx, task_ctx->lbr_to[i]); + } + task_ctx->lbr_stack_state = LBR_NONE; +} + +static void __intel_pmu_lbr_save(struct x86_perf_task_context *task_ctx) +{ + int i; + unsigned lbr_idx, mask; + u64 tos; + + if (task_ctx->lbr_callstack_users == 0) { + task_ctx->lbr_stack_state = LBR_NONE; + return; + } + + mask = x86_pmu.lbr_nr - 1; + tos = intel_pmu_lbr_tos(); + for (i = 0; i < x86_pmu.lbr_nr; i++) { + lbr_idx = (tos - i) & mask; + rdmsrl(x86_pmu.lbr_from + lbr_idx, task_ctx->lbr_from[i]); + rdmsrl(x86_pmu.lbr_to + lbr_idx, task_ctx->lbr_to[i]); + } + task_ctx->lbr_stack_state = LBR_VALID; +} + +void intel_pmu_lbr_sched_task(struct perf_event_context *ctx, bool sched_in) +{ + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); + struct x86_perf_task_context *task_ctx; + + if (!x86_pmu.lbr_nr) + return; + + /* + * If LBR callstack feature is enabled and the stack was saved when + * the task was scheduled out, restore the stack. Otherwise flush + * the LBR stack. + */ + task_ctx = ctx ? ctx->task_ctx_data : NULL; + if (task_ctx) { + if (sched_in) { + __intel_pmu_lbr_restore(task_ctx); + cpuc->lbr_context = ctx; + } else { + __intel_pmu_lbr_save(task_ctx); + } + return; + } + + /* + * When sampling the branck stack in system-wide, it may be + * necessary to flush the stack on context switch. This happens + * when the branch stack does not tag its entries with the pid + * of the current task. Otherwise it becomes impossible to + * associate a branch entry with a task. This ambiguity is more + * likely to appear when the branch stack supports priv level + * filtering and the user sets it to monitor only at the user + * level (which could be a useful measurement in system-wide + * mode). In that case, the risk is high of having a branch + * stack with branch from multiple tasks. + */ + if (sched_in) { + intel_pmu_lbr_reset(); + cpuc->lbr_context = ctx; + } +} + +static inline bool branch_user_callstack(unsigned br_sel) +{ + return (br_sel & X86_BR_USER) && (br_sel & X86_BR_CALL_STACK); +} + void intel_pmu_lbr_enable(struct perf_event *event) { struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); + struct x86_perf_task_context *task_ctx; if (!x86_pmu.lbr_nr) return; @@ -198,18 +322,33 @@ void intel_pmu_lbr_enable(struct perf_event *event) } cpuc->br_sel = event->hw.branch_reg.reg; + if (branch_user_callstack(cpuc->br_sel) && event->ctx && + event->ctx->task_ctx_data) { + task_ctx = event->ctx->task_ctx_data; + task_ctx->lbr_callstack_users++; + } + cpuc->lbr_users++; + perf_sched_cb_inc(event->ctx->pmu); } void intel_pmu_lbr_disable(struct perf_event *event) { struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); + struct x86_perf_task_context *task_ctx; if (!x86_pmu.lbr_nr) return; + if (branch_user_callstack(cpuc->br_sel) && event->ctx && + event->ctx->task_ctx_data) { + task_ctx = event->ctx->task_ctx_data; + task_ctx->lbr_callstack_users--; + } + cpuc->lbr_users--; WARN_ON_ONCE(cpuc->lbr_users < 0); + perf_sched_cb_dec(event->ctx->pmu); if (cpuc->enabled && !cpuc->lbr_users) { __intel_pmu_lbr_disable(); @@ -218,12 +357,12 @@ void intel_pmu_lbr_disable(struct perf_event *event) } } -void intel_pmu_lbr_enable_all(void) +void intel_pmu_lbr_enable_all(bool pmi) { struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); if (cpuc->lbr_users) - __intel_pmu_lbr_enable(); + __intel_pmu_lbr_enable(pmi); } void intel_pmu_lbr_disable_all(void) @@ -234,18 +373,6 @@ void intel_pmu_lbr_disable_all(void) __intel_pmu_lbr_disable(); } -/* - * TOS = most recently recorded branch - */ -static inline u64 intel_pmu_lbr_tos(void) -{ - u64 tos; - - rdmsrl(x86_pmu.lbr_tos, tos); - - return tos; -} - static void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc) { unsigned long mask = x86_pmu.lbr_nr - 1; @@ -350,7 +477,7 @@ void intel_pmu_lbr_read(void) * - in case there is no HW filter * - in case the HW filter has errata or limitations */ -static void intel_pmu_setup_sw_lbr_filter(struct perf_event *event) +static int intel_pmu_setup_sw_lbr_filter(struct perf_event *event) { u64 br_type = event->attr.branch_sample_type; int mask = 0; @@ -387,11 +514,21 @@ static void intel_pmu_setup_sw_lbr_filter(struct perf_event *event) if (br_type & PERF_SAMPLE_BRANCH_COND) mask |= X86_BR_JCC; + if (br_type & PERF_SAMPLE_BRANCH_CALL_STACK) { + if (!x86_pmu_has_lbr_callstack()) + return -EOPNOTSUPP; + if (mask & ~(X86_BR_USER | X86_BR_KERNEL)) + return -EINVAL; + mask |= X86_BR_CALL | X86_BR_IND_CALL | X86_BR_RET | + X86_BR_CALL_STACK; + } + /* * stash actual user request into reg, it may * be used by fixup code for some CPU */ event->hw.branch_reg.reg = mask; + return 0; } /* @@ -403,14 +540,14 @@ static int intel_pmu_setup_hw_lbr_filter(struct perf_event *event) { struct hw_perf_event_extra *reg; u64 br_type = event->attr.branch_sample_type; - u64 mask = 0, m; - u64 v; + u64 mask = 0, v; + int i; - for_each_branch_sample_type(m) { - if (!(br_type & m)) + for (i = 0; i < PERF_SAMPLE_BRANCH_MAX_SHIFT; i++) { + if (!(br_type & (1ULL << i))) continue; - v = x86_pmu.lbr_sel_map[m]; + v = x86_pmu.lbr_sel_map[i]; if (v == LBR_NOT_SUPP) return -EOPNOTSUPP; @@ -420,8 +557,12 @@ static int intel_pmu_setup_hw_lbr_filter(struct perf_event *event) reg = &event->hw.branch_reg; reg->idx = EXTRA_REG_LBR; - /* LBR_SELECT operates in suppress mode so invert mask */ - reg->config = ~mask & x86_pmu.lbr_sel_mask; + /* + * The first 9 bits (LBR_SEL_MASK) in LBR_SELECT operate + * in suppress mode. So LBR_SELECT should be set to + * (~mask & LBR_SEL_MASK) | (mask & ~LBR_SEL_MASK) + */ + reg->config = mask ^ x86_pmu.lbr_sel_mask; return 0; } @@ -439,7 +580,9 @@ int intel_pmu_setup_lbr_filter(struct perf_event *event) /* * setup SW LBR filter */ - intel_pmu_setup_sw_lbr_filter(event); + ret = intel_pmu_setup_sw_lbr_filter(event); + if (ret) + return ret; /* * setup HW LBR filter, if any @@ -568,6 +711,12 @@ static int branch_type(unsigned long from, unsigned long to, int abort) ret = X86_BR_INT; break; case 0xe8: /* call near rel */ + insn_get_immediate(&insn); + if (insn.immediate1.value == 0) { + /* zero length call */ + ret = X86_BR_ZERO_CALL; + break; + } case 0x9a: /* call far absolute */ ret = X86_BR_CALL; break; @@ -678,35 +827,49 @@ intel_pmu_lbr_filter(struct cpu_hw_events *cpuc) /* * Map interface branch filters onto LBR filters */ -static const int nhm_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX] = { - [PERF_SAMPLE_BRANCH_ANY] = LBR_ANY, - [PERF_SAMPLE_BRANCH_USER] = LBR_USER, - [PERF_SAMPLE_BRANCH_KERNEL] = LBR_KERNEL, - [PERF_SAMPLE_BRANCH_HV] = LBR_IGN, - [PERF_SAMPLE_BRANCH_ANY_RETURN] = LBR_RETURN | LBR_REL_JMP - | LBR_IND_JMP | LBR_FAR, +static const int nhm_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = { + [PERF_SAMPLE_BRANCH_ANY_SHIFT] = LBR_ANY, + [PERF_SAMPLE_BRANCH_USER_SHIFT] = LBR_USER, + [PERF_SAMPLE_BRANCH_KERNEL_SHIFT] = LBR_KERNEL, + [PERF_SAMPLE_BRANCH_HV_SHIFT] = LBR_IGN, + [PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT] = LBR_RETURN | LBR_REL_JMP + | LBR_IND_JMP | LBR_FAR, /* * NHM/WSM erratum: must include REL_JMP+IND_JMP to get CALL branches */ - [PERF_SAMPLE_BRANCH_ANY_CALL] = + [PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT] = LBR_REL_CALL | LBR_IND_CALL | LBR_REL_JMP | LBR_IND_JMP | LBR_FAR, /* * NHM/WSM erratum: must include IND_JMP to capture IND_CALL */ - [PERF_SAMPLE_BRANCH_IND_CALL] = LBR_IND_CALL | LBR_IND_JMP, - [PERF_SAMPLE_BRANCH_COND] = LBR_JCC, + [PERF_SAMPLE_BRANCH_IND_CALL_SHIFT] = LBR_IND_CALL | LBR_IND_JMP, + [PERF_SAMPLE_BRANCH_COND_SHIFT] = LBR_JCC, }; -static const int snb_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX] = { - [PERF_SAMPLE_BRANCH_ANY] = LBR_ANY, - [PERF_SAMPLE_BRANCH_USER] = LBR_USER, - [PERF_SAMPLE_BRANCH_KERNEL] = LBR_KERNEL, - [PERF_SAMPLE_BRANCH_HV] = LBR_IGN, - [PERF_SAMPLE_BRANCH_ANY_RETURN] = LBR_RETURN | LBR_FAR, - [PERF_SAMPLE_BRANCH_ANY_CALL] = LBR_REL_CALL | LBR_IND_CALL - | LBR_FAR, - [PERF_SAMPLE_BRANCH_IND_CALL] = LBR_IND_CALL, - [PERF_SAMPLE_BRANCH_COND] = LBR_JCC, +static const int snb_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = { + [PERF_SAMPLE_BRANCH_ANY_SHIFT] = LBR_ANY, + [PERF_SAMPLE_BRANCH_USER_SHIFT] = LBR_USER, + [PERF_SAMPLE_BRANCH_KERNEL_SHIFT] = LBR_KERNEL, + [PERF_SAMPLE_BRANCH_HV_SHIFT] = LBR_IGN, + [PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT] = LBR_RETURN | LBR_FAR, + [PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT] = LBR_REL_CALL | LBR_IND_CALL + | LBR_FAR, + [PERF_SAMPLE_BRANCH_IND_CALL_SHIFT] = LBR_IND_CALL, + [PERF_SAMPLE_BRANCH_COND_SHIFT] = LBR_JCC, +}; + +static const int hsw_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = { + [PERF_SAMPLE_BRANCH_ANY_SHIFT] = LBR_ANY, + [PERF_SAMPLE_BRANCH_USER_SHIFT] = LBR_USER, + [PERF_SAMPLE_BRANCH_KERNEL_SHIFT] = LBR_KERNEL, + [PERF_SAMPLE_BRANCH_HV_SHIFT] = LBR_IGN, + [PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT] = LBR_RETURN | LBR_FAR, + [PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT] = LBR_REL_CALL | LBR_IND_CALL + | LBR_FAR, + [PERF_SAMPLE_BRANCH_IND_CALL_SHIFT] = LBR_IND_CALL, + [PERF_SAMPLE_BRANCH_COND_SHIFT] = LBR_JCC, + [PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT] = LBR_REL_CALL | LBR_IND_CALL + | LBR_RETURN | LBR_CALL_STACK, }; /* core */ @@ -765,6 +928,20 @@ void __init intel_pmu_lbr_init_snb(void) pr_cont("16-deep LBR, "); } +/* haswell */ +void intel_pmu_lbr_init_hsw(void) +{ + x86_pmu.lbr_nr = 16; + x86_pmu.lbr_tos = MSR_LBR_TOS; + x86_pmu.lbr_from = MSR_LBR_NHM_FROM; + x86_pmu.lbr_to = MSR_LBR_NHM_TO; + + x86_pmu.lbr_sel_mask = LBR_SEL_MASK; + x86_pmu.lbr_sel_map = hsw_lbr_sel_map; + + pr_cont("16-deep LBR, "); +} + /* atom */ void __init intel_pmu_lbr_init_atom(void) { |