From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- arch/x86/events/amd/lbr.c | 439 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 439 insertions(+) create mode 100644 arch/x86/events/amd/lbr.c (limited to 'arch/x86/events/amd/lbr.c') diff --git a/arch/x86/events/amd/lbr.c b/arch/x86/events/amd/lbr.c new file mode 100644 index 000000000..38a75216c --- /dev/null +++ b/arch/x86/events/amd/lbr.c @@ -0,0 +1,439 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include + +#include "../perf_event.h" + +/* LBR Branch Select valid bits */ +#define LBR_SELECT_MASK 0x1ff + +/* + * LBR Branch Select filter bits which when set, ensures that the + * corresponding type of branches are not recorded + */ +#define LBR_SELECT_KERNEL 0 /* Branches ending in CPL = 0 */ +#define LBR_SELECT_USER 1 /* Branches ending in CPL > 0 */ +#define LBR_SELECT_JCC 2 /* Conditional branches */ +#define LBR_SELECT_CALL_NEAR_REL 3 /* Near relative calls */ +#define LBR_SELECT_CALL_NEAR_IND 4 /* Indirect relative calls */ +#define LBR_SELECT_RET_NEAR 5 /* Near returns */ +#define LBR_SELECT_JMP_NEAR_IND 6 /* Near indirect jumps (excl. calls and returns) */ +#define LBR_SELECT_JMP_NEAR_REL 7 /* Near relative jumps (excl. calls) */ +#define LBR_SELECT_FAR_BRANCH 8 /* Far branches */ + +#define LBR_KERNEL BIT(LBR_SELECT_KERNEL) +#define LBR_USER BIT(LBR_SELECT_USER) +#define LBR_JCC BIT(LBR_SELECT_JCC) +#define LBR_REL_CALL BIT(LBR_SELECT_CALL_NEAR_REL) +#define LBR_IND_CALL BIT(LBR_SELECT_CALL_NEAR_IND) +#define LBR_RETURN BIT(LBR_SELECT_RET_NEAR) +#define LBR_REL_JMP BIT(LBR_SELECT_JMP_NEAR_REL) +#define LBR_IND_JMP BIT(LBR_SELECT_JMP_NEAR_IND) +#define LBR_FAR BIT(LBR_SELECT_FAR_BRANCH) +#define LBR_NOT_SUPP -1 /* unsupported filter */ +#define LBR_IGNORE 0 + +#define LBR_ANY \ + (LBR_JCC | LBR_REL_CALL | LBR_IND_CALL | LBR_RETURN | \ + LBR_REL_JMP | LBR_IND_JMP | LBR_FAR) + +struct branch_entry { + union { + struct { + u64 ip:58; + u64 ip_sign_ext:5; + u64 mispredict:1; + } split; + u64 full; + } from; + + union { + struct { + u64 ip:58; + u64 ip_sign_ext:3; + u64 reserved:1; + u64 spec:1; + u64 valid:1; + } split; + u64 full; + } to; +}; + +static __always_inline void amd_pmu_lbr_set_from(unsigned int idx, u64 val) +{ + wrmsrl(MSR_AMD_SAMP_BR_FROM + idx * 2, val); +} + +static __always_inline void amd_pmu_lbr_set_to(unsigned int idx, u64 val) +{ + wrmsrl(MSR_AMD_SAMP_BR_FROM + idx * 2 + 1, val); +} + +static __always_inline u64 amd_pmu_lbr_get_from(unsigned int idx) +{ + u64 val; + + rdmsrl(MSR_AMD_SAMP_BR_FROM + idx * 2, val); + + return val; +} + +static __always_inline u64 amd_pmu_lbr_get_to(unsigned int idx) +{ + u64 val; + + rdmsrl(MSR_AMD_SAMP_BR_FROM + idx * 2 + 1, val); + + return val; +} + +static __always_inline u64 sign_ext_branch_ip(u64 ip) +{ + u32 shift = 64 - boot_cpu_data.x86_virt_bits; + + return (u64)(((s64)ip << shift) >> shift); +} + +static void amd_pmu_lbr_filter(void) +{ + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); + int br_sel = cpuc->br_sel, offset, type, i, j; + bool compress = false; + bool fused_only = false; + u64 from, to; + + /* If sampling all branches, there is nothing to filter */ + if (((br_sel & X86_BR_ALL) == X86_BR_ALL) && + ((br_sel & X86_BR_TYPE_SAVE) != X86_BR_TYPE_SAVE)) + fused_only = true; + + for (i = 0; i < cpuc->lbr_stack.nr; i++) { + from = cpuc->lbr_entries[i].from; + to = cpuc->lbr_entries[i].to; + type = branch_type_fused(from, to, 0, &offset); + + /* + * Adjust the branch from address in case of instruction + * fusion where it points to an instruction preceding the + * actual branch + */ + if (offset) { + cpuc->lbr_entries[i].from += offset; + if (fused_only) + continue; + } + + /* If type does not correspond, then discard */ + if (type == X86_BR_NONE || (br_sel & type) != type) { + cpuc->lbr_entries[i].from = 0; /* mark invalid */ + compress = true; + } + + if ((br_sel & X86_BR_TYPE_SAVE) == X86_BR_TYPE_SAVE) + cpuc->lbr_entries[i].type = common_branch_type(type); + } + + if (!compress) + return; + + /* Remove all invalid entries */ + for (i = 0; i < cpuc->lbr_stack.nr; ) { + if (!cpuc->lbr_entries[i].from) { + j = i; + while (++j < cpuc->lbr_stack.nr) + cpuc->lbr_entries[j - 1] = cpuc->lbr_entries[j]; + cpuc->lbr_stack.nr--; + if (!cpuc->lbr_entries[i].from) + continue; + } + i++; + } +} + +static const int lbr_spec_map[PERF_BR_SPEC_MAX] = { + PERF_BR_SPEC_NA, + PERF_BR_SPEC_WRONG_PATH, + PERF_BR_NON_SPEC_CORRECT_PATH, + PERF_BR_SPEC_CORRECT_PATH, +}; + +void amd_pmu_lbr_read(void) +{ + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); + struct perf_branch_entry *br = cpuc->lbr_entries; + struct branch_entry entry; + int out = 0, idx, i; + + if (!cpuc->lbr_users) + return; + + for (i = 0; i < x86_pmu.lbr_nr; i++) { + entry.from.full = amd_pmu_lbr_get_from(i); + entry.to.full = amd_pmu_lbr_get_to(i); + + /* + * Check if a branch has been logged; if valid = 0, spec = 0 + * then no branch was recorded + */ + if (!entry.to.split.valid && !entry.to.split.spec) + continue; + + perf_clear_branch_entry_bitfields(br + out); + + br[out].from = sign_ext_branch_ip(entry.from.split.ip); + br[out].to = sign_ext_branch_ip(entry.to.split.ip); + br[out].mispred = entry.from.split.mispredict; + br[out].predicted = !br[out].mispred; + + /* + * Set branch speculation information using the status of + * the valid and spec bits. + * + * When valid = 0, spec = 0, no branch was recorded and the + * entry is discarded as seen above. + * + * When valid = 0, spec = 1, the recorded branch was + * speculative but took the wrong path. + * + * When valid = 1, spec = 0, the recorded branch was + * non-speculative but took the correct path. + * + * When valid = 1, spec = 1, the recorded branch was + * speculative and took the correct path + */ + idx = (entry.to.split.valid << 1) | entry.to.split.spec; + br[out].spec = lbr_spec_map[idx]; + out++; + } + + cpuc->lbr_stack.nr = out; + + /* + * Internal register renaming always ensures that LBR From[0] and + * LBR To[0] always represent the TOS + */ + cpuc->lbr_stack.hw_idx = 0; + + /* Perform further software filtering */ + amd_pmu_lbr_filter(); +} + +static const int lbr_select_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = { + [PERF_SAMPLE_BRANCH_USER_SHIFT] = LBR_USER, + [PERF_SAMPLE_BRANCH_KERNEL_SHIFT] = LBR_KERNEL, + [PERF_SAMPLE_BRANCH_HV_SHIFT] = LBR_IGNORE, + + [PERF_SAMPLE_BRANCH_ANY_SHIFT] = LBR_ANY, + [PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT] = LBR_REL_CALL | LBR_IND_CALL | LBR_FAR, + [PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT] = LBR_RETURN | LBR_FAR, + [PERF_SAMPLE_BRANCH_IND_CALL_SHIFT] = LBR_IND_CALL, + [PERF_SAMPLE_BRANCH_ABORT_TX_SHIFT] = LBR_NOT_SUPP, + [PERF_SAMPLE_BRANCH_IN_TX_SHIFT] = LBR_NOT_SUPP, + [PERF_SAMPLE_BRANCH_NO_TX_SHIFT] = LBR_NOT_SUPP, + [PERF_SAMPLE_BRANCH_COND_SHIFT] = LBR_JCC, + + [PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT] = LBR_NOT_SUPP, + [PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT] = LBR_IND_JMP, + [PERF_SAMPLE_BRANCH_CALL_SHIFT] = LBR_REL_CALL, + + [PERF_SAMPLE_BRANCH_NO_FLAGS_SHIFT] = LBR_NOT_SUPP, + [PERF_SAMPLE_BRANCH_NO_CYCLES_SHIFT] = LBR_NOT_SUPP, +}; + +static int amd_pmu_lbr_setup_filter(struct perf_event *event) +{ + struct hw_perf_event_extra *reg = &event->hw.branch_reg; + u64 br_type = event->attr.branch_sample_type; + u64 mask = 0, v; + int i; + + /* No LBR support */ + if (!x86_pmu.lbr_nr) + return -EOPNOTSUPP; + + if (br_type & PERF_SAMPLE_BRANCH_USER) + mask |= X86_BR_USER; + + if (br_type & PERF_SAMPLE_BRANCH_KERNEL) + mask |= X86_BR_KERNEL; + + /* Ignore BRANCH_HV here */ + + if (br_type & PERF_SAMPLE_BRANCH_ANY) + mask |= X86_BR_ANY; + + if (br_type & PERF_SAMPLE_BRANCH_ANY_CALL) + mask |= X86_BR_ANY_CALL; + + if (br_type & PERF_SAMPLE_BRANCH_ANY_RETURN) + mask |= X86_BR_RET | X86_BR_IRET | X86_BR_SYSRET; + + if (br_type & PERF_SAMPLE_BRANCH_IND_CALL) + mask |= X86_BR_IND_CALL; + + if (br_type & PERF_SAMPLE_BRANCH_COND) + mask |= X86_BR_JCC; + + if (br_type & PERF_SAMPLE_BRANCH_IND_JUMP) + mask |= X86_BR_IND_JMP; + + if (br_type & PERF_SAMPLE_BRANCH_CALL) + mask |= X86_BR_CALL | X86_BR_ZERO_CALL; + + if (br_type & PERF_SAMPLE_BRANCH_TYPE_SAVE) + mask |= X86_BR_TYPE_SAVE; + + reg->reg = mask; + mask = 0; + + for (i = 0; i < PERF_SAMPLE_BRANCH_MAX_SHIFT; i++) { + if (!(br_type & BIT_ULL(i))) + continue; + + v = lbr_select_map[i]; + if (v == LBR_NOT_SUPP) + return -EOPNOTSUPP; + + if (v != LBR_IGNORE) + mask |= v; + } + + /* Filter bits operate in suppress mode */ + reg->config = mask ^ LBR_SELECT_MASK; + + return 0; +} + +int amd_pmu_lbr_hw_config(struct perf_event *event) +{ + int ret = 0; + + /* LBR is not recommended in counting mode */ + if (!is_sampling_event(event)) + return -EINVAL; + + ret = amd_pmu_lbr_setup_filter(event); + if (!ret) + event->attach_state |= PERF_ATTACH_SCHED_CB; + + return ret; +} + +void amd_pmu_lbr_reset(void) +{ + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); + int i; + + if (!x86_pmu.lbr_nr) + return; + + /* Reset all branch records individually */ + for (i = 0; i < x86_pmu.lbr_nr; i++) { + amd_pmu_lbr_set_from(i, 0); + amd_pmu_lbr_set_to(i, 0); + } + + cpuc->last_task_ctx = NULL; + cpuc->last_log_id = 0; + wrmsrl(MSR_AMD64_LBR_SELECT, 0); +} + +void amd_pmu_lbr_add(struct perf_event *event) +{ + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); + struct hw_perf_event_extra *reg = &event->hw.branch_reg; + + if (!x86_pmu.lbr_nr) + return; + + if (has_branch_stack(event)) { + cpuc->lbr_select = 1; + cpuc->lbr_sel->config = reg->config; + cpuc->br_sel = reg->reg; + } + + perf_sched_cb_inc(event->ctx->pmu); + + if (!cpuc->lbr_users++ && !event->total_time_running) + amd_pmu_lbr_reset(); +} + +void amd_pmu_lbr_del(struct perf_event *event) +{ + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); + + if (!x86_pmu.lbr_nr) + return; + + if (has_branch_stack(event)) + cpuc->lbr_select = 0; + + cpuc->lbr_users--; + WARN_ON_ONCE(cpuc->lbr_users < 0); + perf_sched_cb_dec(event->ctx->pmu); +} + +void amd_pmu_lbr_sched_task(struct perf_event_context *ctx, bool sched_in) +{ + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); + + /* + * A context switch can flip the address space and LBR entries are + * not tagged with an identifier. Hence, branches cannot be resolved + * from the old address space and the LBR records should be wiped. + */ + if (cpuc->lbr_users && sched_in) + amd_pmu_lbr_reset(); +} + +void amd_pmu_lbr_enable_all(void) +{ + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); + u64 lbr_select, dbg_ctl, dbg_extn_cfg; + + if (!cpuc->lbr_users || !x86_pmu.lbr_nr) + return; + + /* Set hardware branch filter */ + if (cpuc->lbr_select) { + lbr_select = cpuc->lbr_sel->config & LBR_SELECT_MASK; + wrmsrl(MSR_AMD64_LBR_SELECT, lbr_select); + } + + rdmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl); + rdmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg); + + wrmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl | DEBUGCTLMSR_FREEZE_LBRS_ON_PMI); + wrmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg | DBG_EXTN_CFG_LBRV2EN); +} + +void amd_pmu_lbr_disable_all(void) +{ + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); + u64 dbg_ctl, dbg_extn_cfg; + + if (!cpuc->lbr_users || !x86_pmu.lbr_nr) + return; + + rdmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg); + rdmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl); + + wrmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg & ~DBG_EXTN_CFG_LBRV2EN); + wrmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl & ~DEBUGCTLMSR_FREEZE_LBRS_ON_PMI); +} + +__init int amd_pmu_lbr_init(void) +{ + union cpuid_0x80000022_ebx ebx; + + if (x86_pmu.version < 2 || !boot_cpu_has(X86_FEATURE_AMD_LBR_V2)) + return -EOPNOTSUPP; + + /* Set number of entries */ + ebx.full = cpuid_ebx(EXT_PERFMON_DEBUG_FEATURES); + x86_pmu.lbr_nr = ebx.split.lbr_v2_stack_sz; + + pr_cont("%d-deep LBR, ", x86_pmu.lbr_nr); + + return 0; +} -- cgit v1.2.3