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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/events/intel/lbr.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/events/intel/lbr.c')
-rw-r--r--arch/x86/events/intel/lbr.c1620
1 files changed, 1620 insertions, 0 deletions
diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c
new file mode 100644
index 000000000..4dbde69c4
--- /dev/null
+++ b/arch/x86/events/intel/lbr.c
@@ -0,0 +1,1620 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/perf_event.h>
+#include <linux/types.h>
+
+#include <asm/perf_event.h>
+#include <asm/msr.h>
+
+#include "../perf_event.h"
+
+/*
+ * Intel LBR_SELECT bits
+ * Intel Vol3a, April 2011, Section 16.7 Table 16-10
+ *
+ * Hardware branch filter (not available on all CPUs)
+ */
+#define LBR_KERNEL_BIT 0 /* do not capture at ring0 */
+#define LBR_USER_BIT 1 /* do not capture at ring > 0 */
+#define LBR_JCC_BIT 2 /* do not capture conditional branches */
+#define LBR_REL_CALL_BIT 3 /* do not capture relative calls */
+#define LBR_IND_CALL_BIT 4 /* do not capture indirect calls */
+#define LBR_RETURN_BIT 5 /* do not capture near returns */
+#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 */
+
+/*
+ * Following bit only exists in Linux; we mask it out before writing it to
+ * the actual MSR. But it helps the constraint perf code to understand
+ * that this is a separate configuration.
+ */
+#define LBR_NO_INFO_BIT 63 /* don't read LBR_INFO. */
+
+#define LBR_KERNEL (1 << LBR_KERNEL_BIT)
+#define LBR_USER (1 << LBR_USER_BIT)
+#define LBR_JCC (1 << LBR_JCC_BIT)
+#define LBR_REL_CALL (1 << LBR_REL_CALL_BIT)
+#define LBR_IND_CALL (1 << LBR_IND_CALL_BIT)
+#define LBR_RETURN (1 << LBR_RETURN_BIT)
+#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_NO_INFO (1ULL << LBR_NO_INFO_BIT)
+
+#define LBR_PLM (LBR_KERNEL | LBR_USER)
+
+#define LBR_SEL_MASK 0x3ff /* valid bits in LBR_SELECT */
+#define LBR_NOT_SUPP -1 /* LBR filter not supported */
+#define LBR_IGN 0 /* ignored */
+
+#define LBR_ANY \
+ (LBR_JCC |\
+ LBR_REL_CALL |\
+ LBR_IND_CALL |\
+ LBR_RETURN |\
+ LBR_REL_JMP |\
+ LBR_IND_JMP |\
+ LBR_FAR)
+
+#define LBR_FROM_FLAG_MISPRED BIT_ULL(63)
+#define LBR_FROM_FLAG_IN_TX BIT_ULL(62)
+#define LBR_FROM_FLAG_ABORT BIT_ULL(61)
+
+#define LBR_FROM_SIGNEXT_2MSB (BIT_ULL(60) | BIT_ULL(59))
+
+/*
+ * Intel LBR_CTL bits
+ *
+ * Hardware branch filter for Arch LBR
+ */
+#define ARCH_LBR_KERNEL_BIT 1 /* capture at ring0 */
+#define ARCH_LBR_USER_BIT 2 /* capture at ring > 0 */
+#define ARCH_LBR_CALL_STACK_BIT 3 /* enable call stack */
+#define ARCH_LBR_JCC_BIT 16 /* capture conditional branches */
+#define ARCH_LBR_REL_JMP_BIT 17 /* capture relative jumps */
+#define ARCH_LBR_IND_JMP_BIT 18 /* capture indirect jumps */
+#define ARCH_LBR_REL_CALL_BIT 19 /* capture relative calls */
+#define ARCH_LBR_IND_CALL_BIT 20 /* capture indirect calls */
+#define ARCH_LBR_RETURN_BIT 21 /* capture near returns */
+#define ARCH_LBR_OTHER_BRANCH_BIT 22 /* capture other branches */
+
+#define ARCH_LBR_KERNEL (1ULL << ARCH_LBR_KERNEL_BIT)
+#define ARCH_LBR_USER (1ULL << ARCH_LBR_USER_BIT)
+#define ARCH_LBR_CALL_STACK (1ULL << ARCH_LBR_CALL_STACK_BIT)
+#define ARCH_LBR_JCC (1ULL << ARCH_LBR_JCC_BIT)
+#define ARCH_LBR_REL_JMP (1ULL << ARCH_LBR_REL_JMP_BIT)
+#define ARCH_LBR_IND_JMP (1ULL << ARCH_LBR_IND_JMP_BIT)
+#define ARCH_LBR_REL_CALL (1ULL << ARCH_LBR_REL_CALL_BIT)
+#define ARCH_LBR_IND_CALL (1ULL << ARCH_LBR_IND_CALL_BIT)
+#define ARCH_LBR_RETURN (1ULL << ARCH_LBR_RETURN_BIT)
+#define ARCH_LBR_OTHER_BRANCH (1ULL << ARCH_LBR_OTHER_BRANCH_BIT)
+
+#define ARCH_LBR_ANY \
+ (ARCH_LBR_JCC |\
+ ARCH_LBR_REL_JMP |\
+ ARCH_LBR_IND_JMP |\
+ ARCH_LBR_REL_CALL |\
+ ARCH_LBR_IND_CALL |\
+ ARCH_LBR_RETURN |\
+ ARCH_LBR_OTHER_BRANCH)
+
+#define ARCH_LBR_CTL_MASK 0x7f000e
+
+static void intel_pmu_lbr_filter(struct cpu_hw_events *cpuc);
+
+static __always_inline bool is_lbr_call_stack_bit_set(u64 config)
+{
+ if (static_cpu_has(X86_FEATURE_ARCH_LBR))
+ return !!(config & ARCH_LBR_CALL_STACK);
+
+ return !!(config & LBR_CALL_STACK);
+}
+
+/*
+ * We only support LBR implementations that have FREEZE_LBRS_ON_PMI
+ * otherwise it becomes near impossible to get a reliable stack.
+ */
+
+static void __intel_pmu_lbr_enable(bool pmi)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ u64 debugctl, lbr_select = 0, orig_debugctl;
+
+ /*
+ * No need to unfreeze manually, as v4 can do that as part
+ * of the GLOBAL_STATUS ack.
+ */
+ if (pmi && x86_pmu.version >= 4)
+ return;
+
+ /*
+ * No need to reprogram LBR_SELECT in a PMI, as it
+ * did not change.
+ */
+ if (cpuc->lbr_sel)
+ lbr_select = cpuc->lbr_sel->config & x86_pmu.lbr_sel_mask;
+ if (!static_cpu_has(X86_FEATURE_ARCH_LBR) && !pmi && cpuc->lbr_sel)
+ wrmsrl(MSR_LBR_SELECT, lbr_select);
+
+ rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+ orig_debugctl = debugctl;
+
+ if (!static_cpu_has(X86_FEATURE_ARCH_LBR))
+ 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 (is_lbr_call_stack_bit_set(lbr_select))
+ debugctl &= ~DEBUGCTLMSR_FREEZE_LBRS_ON_PMI;
+ else
+ debugctl |= DEBUGCTLMSR_FREEZE_LBRS_ON_PMI;
+
+ if (orig_debugctl != debugctl)
+ wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+
+ if (static_cpu_has(X86_FEATURE_ARCH_LBR))
+ wrmsrl(MSR_ARCH_LBR_CTL, lbr_select | ARCH_LBR_CTL_LBREN);
+}
+
+void intel_pmu_lbr_reset_32(void)
+{
+ int i;
+
+ for (i = 0; i < x86_pmu.lbr_nr; i++)
+ wrmsrl(x86_pmu.lbr_from + i, 0);
+}
+
+void intel_pmu_lbr_reset_64(void)
+{
+ int i;
+
+ for (i = 0; i < x86_pmu.lbr_nr; i++) {
+ wrmsrl(x86_pmu.lbr_from + i, 0);
+ wrmsrl(x86_pmu.lbr_to + i, 0);
+ if (x86_pmu.lbr_has_info)
+ wrmsrl(x86_pmu.lbr_info + i, 0);
+ }
+}
+
+static void intel_pmu_arch_lbr_reset(void)
+{
+ /* Write to ARCH_LBR_DEPTH MSR, all LBR entries are reset to 0 */
+ wrmsrl(MSR_ARCH_LBR_DEPTH, x86_pmu.lbr_nr);
+}
+
+void intel_pmu_lbr_reset(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ if (!x86_pmu.lbr_nr)
+ return;
+
+ x86_pmu.lbr_reset();
+
+ cpuc->last_task_ctx = NULL;
+ cpuc->last_log_id = 0;
+ if (!static_cpu_has(X86_FEATURE_ARCH_LBR) && cpuc->lbr_select)
+ wrmsrl(MSR_LBR_SELECT, 0);
+}
+
+/*
+ * 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,
+};
+
+/*
+ * For format LBR_FORMAT_EIP_FLAGS2, bits 61:62 in MSR_LAST_BRANCH_FROM_x
+ * are the TSX flags when TSX is supported, but when TSX is not supported
+ * they have no consistent behavior:
+ *
+ * - For wrmsr(), bits 61:62 are considered part of the sign extension.
+ * - For HW updates (branch captures) bits 61:62 are always OFF and are not
+ * part of the sign extension.
+ *
+ * Therefore, if:
+ *
+ * 1) LBR format LBR_FORMAT_EIP_FLAGS2
+ * 2) CPU has no TSX support enabled
+ *
+ * ... then any value passed to wrmsr() must be sign extended to 63 bits and any
+ * value from rdmsr() must be converted to have a 61 bits sign extension,
+ * ignoring the TSX flags.
+ */
+static inline bool lbr_from_signext_quirk_needed(void)
+{
+ bool tsx_support = boot_cpu_has(X86_FEATURE_HLE) ||
+ boot_cpu_has(X86_FEATURE_RTM);
+
+ return !tsx_support;
+}
+
+static DEFINE_STATIC_KEY_FALSE(lbr_from_quirk_key);
+
+/* If quirk is enabled, ensure sign extension is 63 bits: */
+inline u64 lbr_from_signext_quirk_wr(u64 val)
+{
+ if (static_branch_unlikely(&lbr_from_quirk_key)) {
+ /*
+ * Sign extend into bits 61:62 while preserving bit 63.
+ *
+ * Quirk is enabled when TSX is disabled. Therefore TSX bits
+ * in val are always OFF and must be changed to be sign
+ * extension bits. Since bits 59:60 are guaranteed to be
+ * part of the sign extension bits, we can just copy them
+ * to 61:62.
+ */
+ val |= (LBR_FROM_SIGNEXT_2MSB & val) << 2;
+ }
+ return val;
+}
+
+/*
+ * If quirk is needed, ensure sign extension is 61 bits:
+ */
+static u64 lbr_from_signext_quirk_rd(u64 val)
+{
+ if (static_branch_unlikely(&lbr_from_quirk_key)) {
+ /*
+ * Quirk is on when TSX is not enabled. Therefore TSX
+ * flags must be read as OFF.
+ */
+ val &= ~(LBR_FROM_FLAG_IN_TX | LBR_FROM_FLAG_ABORT);
+ }
+ return val;
+}
+
+static __always_inline void wrlbr_from(unsigned int idx, u64 val)
+{
+ val = lbr_from_signext_quirk_wr(val);
+ wrmsrl(x86_pmu.lbr_from + idx, val);
+}
+
+static __always_inline void wrlbr_to(unsigned int idx, u64 val)
+{
+ wrmsrl(x86_pmu.lbr_to + idx, val);
+}
+
+static __always_inline void wrlbr_info(unsigned int idx, u64 val)
+{
+ wrmsrl(x86_pmu.lbr_info + idx, val);
+}
+
+static __always_inline u64 rdlbr_from(unsigned int idx, struct lbr_entry *lbr)
+{
+ u64 val;
+
+ if (lbr)
+ return lbr->from;
+
+ rdmsrl(x86_pmu.lbr_from + idx, val);
+
+ return lbr_from_signext_quirk_rd(val);
+}
+
+static __always_inline u64 rdlbr_to(unsigned int idx, struct lbr_entry *lbr)
+{
+ u64 val;
+
+ if (lbr)
+ return lbr->to;
+
+ rdmsrl(x86_pmu.lbr_to + idx, val);
+
+ return val;
+}
+
+static __always_inline u64 rdlbr_info(unsigned int idx, struct lbr_entry *lbr)
+{
+ u64 val;
+
+ if (lbr)
+ return lbr->info;
+
+ rdmsrl(x86_pmu.lbr_info + idx, val);
+
+ return val;
+}
+
+static inline void
+wrlbr_all(struct lbr_entry *lbr, unsigned int idx, bool need_info)
+{
+ wrlbr_from(idx, lbr->from);
+ wrlbr_to(idx, lbr->to);
+ if (need_info)
+ wrlbr_info(idx, lbr->info);
+}
+
+static inline bool
+rdlbr_all(struct lbr_entry *lbr, unsigned int idx, bool need_info)
+{
+ u64 from = rdlbr_from(idx, NULL);
+
+ /* Don't read invalid entry */
+ if (!from)
+ return false;
+
+ lbr->from = from;
+ lbr->to = rdlbr_to(idx, NULL);
+ if (need_info)
+ lbr->info = rdlbr_info(idx, NULL);
+
+ return true;
+}
+
+void intel_pmu_lbr_restore(void *ctx)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ struct x86_perf_task_context *task_ctx = ctx;
+ bool need_info = x86_pmu.lbr_has_info;
+ u64 tos = task_ctx->tos;
+ unsigned lbr_idx, mask;
+ int i;
+
+ mask = x86_pmu.lbr_nr - 1;
+ for (i = 0; i < task_ctx->valid_lbrs; i++) {
+ lbr_idx = (tos - i) & mask;
+ wrlbr_all(&task_ctx->lbr[i], lbr_idx, need_info);
+ }
+
+ for (; i < x86_pmu.lbr_nr; i++) {
+ lbr_idx = (tos - i) & mask;
+ wrlbr_from(lbr_idx, 0);
+ wrlbr_to(lbr_idx, 0);
+ if (need_info)
+ wrlbr_info(lbr_idx, 0);
+ }
+
+ wrmsrl(x86_pmu.lbr_tos, tos);
+
+ if (cpuc->lbr_select)
+ wrmsrl(MSR_LBR_SELECT, task_ctx->lbr_sel);
+}
+
+static void intel_pmu_arch_lbr_restore(void *ctx)
+{
+ struct x86_perf_task_context_arch_lbr *task_ctx = ctx;
+ struct lbr_entry *entries = task_ctx->entries;
+ int i;
+
+ /* Fast reset the LBRs before restore if the call stack is not full. */
+ if (!entries[x86_pmu.lbr_nr - 1].from)
+ intel_pmu_arch_lbr_reset();
+
+ for (i = 0; i < x86_pmu.lbr_nr; i++) {
+ if (!entries[i].from)
+ break;
+ wrlbr_all(&entries[i], i, true);
+ }
+}
+
+/*
+ * Restore the Architecture LBR state from the xsave area in the perf
+ * context data for the task via the XRSTORS instruction.
+ */
+static void intel_pmu_arch_lbr_xrstors(void *ctx)
+{
+ struct x86_perf_task_context_arch_lbr_xsave *task_ctx = ctx;
+
+ xrstors(&task_ctx->xsave, XFEATURE_MASK_LBR);
+}
+
+static __always_inline bool lbr_is_reset_in_cstate(void *ctx)
+{
+ if (static_cpu_has(X86_FEATURE_ARCH_LBR))
+ return x86_pmu.lbr_deep_c_reset && !rdlbr_from(0, NULL);
+
+ return !rdlbr_from(((struct x86_perf_task_context *)ctx)->tos, NULL);
+}
+
+static void __intel_pmu_lbr_restore(void *ctx)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ if (task_context_opt(ctx)->lbr_callstack_users == 0 ||
+ task_context_opt(ctx)->lbr_stack_state == LBR_NONE) {
+ intel_pmu_lbr_reset();
+ return;
+ }
+
+ /*
+ * Does not restore the LBR registers, if
+ * - No one else touched them, and
+ * - Was not cleared in Cstate
+ */
+ if ((ctx == cpuc->last_task_ctx) &&
+ (task_context_opt(ctx)->log_id == cpuc->last_log_id) &&
+ !lbr_is_reset_in_cstate(ctx)) {
+ task_context_opt(ctx)->lbr_stack_state = LBR_NONE;
+ return;
+ }
+
+ x86_pmu.lbr_restore(ctx);
+
+ task_context_opt(ctx)->lbr_stack_state = LBR_NONE;
+}
+
+void intel_pmu_lbr_save(void *ctx)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ struct x86_perf_task_context *task_ctx = ctx;
+ bool need_info = x86_pmu.lbr_has_info;
+ unsigned lbr_idx, mask;
+ u64 tos;
+ int i;
+
+ 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;
+ if (!rdlbr_all(&task_ctx->lbr[i], lbr_idx, need_info))
+ break;
+ }
+ task_ctx->valid_lbrs = i;
+ task_ctx->tos = tos;
+
+ if (cpuc->lbr_select)
+ rdmsrl(MSR_LBR_SELECT, task_ctx->lbr_sel);
+}
+
+static void intel_pmu_arch_lbr_save(void *ctx)
+{
+ struct x86_perf_task_context_arch_lbr *task_ctx = ctx;
+ struct lbr_entry *entries = task_ctx->entries;
+ int i;
+
+ for (i = 0; i < x86_pmu.lbr_nr; i++) {
+ if (!rdlbr_all(&entries[i], i, true))
+ break;
+ }
+
+ /* LBR call stack is not full. Reset is required in restore. */
+ if (i < x86_pmu.lbr_nr)
+ entries[x86_pmu.lbr_nr - 1].from = 0;
+}
+
+/*
+ * Save the Architecture LBR state to the xsave area in the perf
+ * context data for the task via the XSAVES instruction.
+ */
+static void intel_pmu_arch_lbr_xsaves(void *ctx)
+{
+ struct x86_perf_task_context_arch_lbr_xsave *task_ctx = ctx;
+
+ xsaves(&task_ctx->xsave, XFEATURE_MASK_LBR);
+}
+
+static void __intel_pmu_lbr_save(void *ctx)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ if (task_context_opt(ctx)->lbr_callstack_users == 0) {
+ task_context_opt(ctx)->lbr_stack_state = LBR_NONE;
+ return;
+ }
+
+ x86_pmu.lbr_save(ctx);
+
+ task_context_opt(ctx)->lbr_stack_state = LBR_VALID;
+
+ cpuc->last_task_ctx = ctx;
+ cpuc->last_log_id = ++task_context_opt(ctx)->log_id;
+}
+
+void intel_pmu_lbr_swap_task_ctx(struct perf_event_context *prev,
+ struct perf_event_context *next)
+{
+ void *prev_ctx_data, *next_ctx_data;
+
+ swap(prev->task_ctx_data, next->task_ctx_data);
+
+ /*
+ * Architecture specific synchronization makes sense in
+ * case both prev->task_ctx_data and next->task_ctx_data
+ * pointers are allocated.
+ */
+
+ prev_ctx_data = next->task_ctx_data;
+ next_ctx_data = prev->task_ctx_data;
+
+ if (!prev_ctx_data || !next_ctx_data)
+ return;
+
+ swap(task_context_opt(prev_ctx_data)->lbr_callstack_users,
+ task_context_opt(next_ctx_data)->lbr_callstack_users);
+}
+
+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);
+ void *task_ctx;
+
+ if (!cpuc->lbr_users)
+ 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);
+ else
+ __intel_pmu_lbr_save(task_ctx);
+ return;
+ }
+
+ /*
+ * Since a context switch can flip the address space and LBR entries
+ * are not tagged with an identifier, we need to wipe the LBR, even for
+ * per-cpu events. You simply cannot resolve the branches from the old
+ * address space.
+ */
+ if (sched_in)
+ intel_pmu_lbr_reset();
+}
+
+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_add(struct perf_event *event)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ if (!x86_pmu.lbr_nr)
+ return;
+
+ if (event->hw.flags & PERF_X86_EVENT_LBR_SELECT)
+ cpuc->lbr_select = 1;
+
+ cpuc->br_sel = event->hw.branch_reg.reg;
+
+ if (branch_user_callstack(cpuc->br_sel) && event->ctx->task_ctx_data)
+ task_context_opt(event->ctx->task_ctx_data)->lbr_callstack_users++;
+
+ /*
+ * Request pmu::sched_task() callback, which will fire inside the
+ * regular perf event scheduling, so that call will:
+ *
+ * - restore or wipe; when LBR-callstack,
+ * - wipe; otherwise,
+ *
+ * when this is from __perf_event_task_sched_in().
+ *
+ * However, if this is from perf_install_in_context(), no such callback
+ * will follow and we'll need to reset the LBR here if this is the
+ * first LBR event.
+ *
+ * The problem is, we cannot tell these cases apart... but we can
+ * exclude the biggest chunk of cases by looking at
+ * event->total_time_running. An event that has accrued runtime cannot
+ * be 'new'. Conversely, a new event can get installed through the
+ * context switch path for the first time.
+ */
+ if (x86_pmu.intel_cap.pebs_baseline && event->attr.precise_ip > 0)
+ cpuc->lbr_pebs_users++;
+ perf_sched_cb_inc(event->ctx->pmu);
+ if (!cpuc->lbr_users++ && !event->total_time_running)
+ intel_pmu_lbr_reset();
+}
+
+void release_lbr_buffers(void)
+{
+ struct kmem_cache *kmem_cache;
+ struct cpu_hw_events *cpuc;
+ int cpu;
+
+ if (!static_cpu_has(X86_FEATURE_ARCH_LBR))
+ return;
+
+ for_each_possible_cpu(cpu) {
+ cpuc = per_cpu_ptr(&cpu_hw_events, cpu);
+ kmem_cache = x86_get_pmu(cpu)->task_ctx_cache;
+ if (kmem_cache && cpuc->lbr_xsave) {
+ kmem_cache_free(kmem_cache, cpuc->lbr_xsave);
+ cpuc->lbr_xsave = NULL;
+ }
+ }
+}
+
+void reserve_lbr_buffers(void)
+{
+ struct kmem_cache *kmem_cache;
+ struct cpu_hw_events *cpuc;
+ int cpu;
+
+ if (!static_cpu_has(X86_FEATURE_ARCH_LBR))
+ return;
+
+ for_each_possible_cpu(cpu) {
+ cpuc = per_cpu_ptr(&cpu_hw_events, cpu);
+ kmem_cache = x86_get_pmu(cpu)->task_ctx_cache;
+ if (!kmem_cache || cpuc->lbr_xsave)
+ continue;
+
+ cpuc->lbr_xsave = kmem_cache_alloc_node(kmem_cache,
+ GFP_KERNEL | __GFP_ZERO,
+ cpu_to_node(cpu));
+ }
+}
+
+void intel_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 (branch_user_callstack(cpuc->br_sel) &&
+ event->ctx->task_ctx_data)
+ task_context_opt(event->ctx->task_ctx_data)->lbr_callstack_users--;
+
+ if (event->hw.flags & PERF_X86_EVENT_LBR_SELECT)
+ cpuc->lbr_select = 0;
+
+ if (x86_pmu.intel_cap.pebs_baseline && event->attr.precise_ip > 0)
+ cpuc->lbr_pebs_users--;
+ cpuc->lbr_users--;
+ WARN_ON_ONCE(cpuc->lbr_users < 0);
+ WARN_ON_ONCE(cpuc->lbr_pebs_users < 0);
+ perf_sched_cb_dec(event->ctx->pmu);
+}
+
+static inline bool vlbr_exclude_host(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ return test_bit(INTEL_PMC_IDX_FIXED_VLBR,
+ (unsigned long *)&cpuc->intel_ctrl_guest_mask);
+}
+
+void intel_pmu_lbr_enable_all(bool pmi)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ if (cpuc->lbr_users && !vlbr_exclude_host())
+ __intel_pmu_lbr_enable(pmi);
+}
+
+void intel_pmu_lbr_disable_all(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ if (cpuc->lbr_users && !vlbr_exclude_host()) {
+ if (static_cpu_has(X86_FEATURE_ARCH_LBR))
+ return __intel_pmu_arch_lbr_disable();
+
+ __intel_pmu_lbr_disable();
+ }
+}
+
+void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc)
+{
+ unsigned long mask = x86_pmu.lbr_nr - 1;
+ struct perf_branch_entry *br = cpuc->lbr_entries;
+ u64 tos = intel_pmu_lbr_tos();
+ int i;
+
+ for (i = 0; i < x86_pmu.lbr_nr; i++) {
+ unsigned long lbr_idx = (tos - i) & mask;
+ union {
+ struct {
+ u32 from;
+ u32 to;
+ };
+ u64 lbr;
+ } msr_lastbranch;
+
+ rdmsrl(x86_pmu.lbr_from + lbr_idx, msr_lastbranch.lbr);
+
+ perf_clear_branch_entry_bitfields(br);
+
+ br->from = msr_lastbranch.from;
+ br->to = msr_lastbranch.to;
+ br++;
+ }
+ cpuc->lbr_stack.nr = i;
+ cpuc->lbr_stack.hw_idx = tos;
+}
+
+/*
+ * Due to lack of segmentation in Linux the effective address (offset)
+ * is the same as the linear address, allowing us to merge the LIP and EIP
+ * LBR formats.
+ */
+void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc)
+{
+ bool need_info = false, call_stack = false;
+ unsigned long mask = x86_pmu.lbr_nr - 1;
+ struct perf_branch_entry *br = cpuc->lbr_entries;
+ u64 tos = intel_pmu_lbr_tos();
+ int i;
+ int out = 0;
+ int num = x86_pmu.lbr_nr;
+
+ if (cpuc->lbr_sel) {
+ need_info = !(cpuc->lbr_sel->config & LBR_NO_INFO);
+ if (cpuc->lbr_sel->config & LBR_CALL_STACK)
+ call_stack = true;
+ }
+
+ for (i = 0; i < num; i++) {
+ unsigned long lbr_idx = (tos - i) & mask;
+ u64 from, to, mis = 0, pred = 0, in_tx = 0, abort = 0;
+ u16 cycles = 0;
+
+ from = rdlbr_from(lbr_idx, NULL);
+ to = rdlbr_to(lbr_idx, NULL);
+
+ /*
+ * Read LBR call stack entries
+ * until invalid entry (0s) is detected.
+ */
+ if (call_stack && !from)
+ break;
+
+ if (x86_pmu.lbr_has_info) {
+ if (need_info) {
+ u64 info;
+
+ info = rdlbr_info(lbr_idx, NULL);
+ mis = !!(info & LBR_INFO_MISPRED);
+ pred = !mis;
+ cycles = (info & LBR_INFO_CYCLES);
+ if (x86_pmu.lbr_has_tsx) {
+ in_tx = !!(info & LBR_INFO_IN_TX);
+ abort = !!(info & LBR_INFO_ABORT);
+ }
+ }
+ } else {
+ int skip = 0;
+
+ if (x86_pmu.lbr_from_flags) {
+ mis = !!(from & LBR_FROM_FLAG_MISPRED);
+ pred = !mis;
+ skip = 1;
+ }
+ if (x86_pmu.lbr_has_tsx) {
+ in_tx = !!(from & LBR_FROM_FLAG_IN_TX);
+ abort = !!(from & LBR_FROM_FLAG_ABORT);
+ skip = 3;
+ }
+ from = (u64)((((s64)from) << skip) >> skip);
+
+ if (x86_pmu.lbr_to_cycles) {
+ cycles = ((to >> 48) & LBR_INFO_CYCLES);
+ to = (u64)((((s64)to) << 16) >> 16);
+ }
+ }
+
+ /*
+ * Some CPUs report duplicated abort records,
+ * with the second entry not having an abort bit set.
+ * Skip them here. This loop runs backwards,
+ * so we need to undo the previous record.
+ * If the abort just happened outside the window
+ * the extra entry cannot be removed.
+ */
+ if (abort && x86_pmu.lbr_double_abort && out > 0)
+ out--;
+
+ perf_clear_branch_entry_bitfields(br+out);
+ br[out].from = from;
+ br[out].to = to;
+ br[out].mispred = mis;
+ br[out].predicted = pred;
+ br[out].in_tx = in_tx;
+ br[out].abort = abort;
+ br[out].cycles = cycles;
+ out++;
+ }
+ cpuc->lbr_stack.nr = out;
+ cpuc->lbr_stack.hw_idx = tos;
+}
+
+static DEFINE_STATIC_KEY_FALSE(x86_lbr_mispred);
+static DEFINE_STATIC_KEY_FALSE(x86_lbr_cycles);
+static DEFINE_STATIC_KEY_FALSE(x86_lbr_type);
+
+static __always_inline int get_lbr_br_type(u64 info)
+{
+ int type = 0;
+
+ if (static_branch_likely(&x86_lbr_type))
+ type = (info & LBR_INFO_BR_TYPE) >> LBR_INFO_BR_TYPE_OFFSET;
+
+ return type;
+}
+
+static __always_inline bool get_lbr_mispred(u64 info)
+{
+ bool mispred = 0;
+
+ if (static_branch_likely(&x86_lbr_mispred))
+ mispred = !!(info & LBR_INFO_MISPRED);
+
+ return mispred;
+}
+
+static __always_inline u16 get_lbr_cycles(u64 info)
+{
+ u16 cycles = info & LBR_INFO_CYCLES;
+
+ if (static_cpu_has(X86_FEATURE_ARCH_LBR) &&
+ (!static_branch_likely(&x86_lbr_cycles) ||
+ !(info & LBR_INFO_CYC_CNT_VALID)))
+ cycles = 0;
+
+ return cycles;
+}
+
+static void intel_pmu_store_lbr(struct cpu_hw_events *cpuc,
+ struct lbr_entry *entries)
+{
+ struct perf_branch_entry *e;
+ struct lbr_entry *lbr;
+ u64 from, to, info;
+ int i;
+
+ for (i = 0; i < x86_pmu.lbr_nr; i++) {
+ lbr = entries ? &entries[i] : NULL;
+ e = &cpuc->lbr_entries[i];
+
+ from = rdlbr_from(i, lbr);
+ /*
+ * Read LBR entries until invalid entry (0s) is detected.
+ */
+ if (!from)
+ break;
+
+ to = rdlbr_to(i, lbr);
+ info = rdlbr_info(i, lbr);
+
+ perf_clear_branch_entry_bitfields(e);
+
+ e->from = from;
+ e->to = to;
+ e->mispred = get_lbr_mispred(info);
+ e->predicted = !e->mispred;
+ e->in_tx = !!(info & LBR_INFO_IN_TX);
+ e->abort = !!(info & LBR_INFO_ABORT);
+ e->cycles = get_lbr_cycles(info);
+ e->type = get_lbr_br_type(info);
+ }
+
+ cpuc->lbr_stack.nr = i;
+}
+
+static void intel_pmu_arch_lbr_read(struct cpu_hw_events *cpuc)
+{
+ intel_pmu_store_lbr(cpuc, NULL);
+}
+
+static void intel_pmu_arch_lbr_read_xsave(struct cpu_hw_events *cpuc)
+{
+ struct x86_perf_task_context_arch_lbr_xsave *xsave = cpuc->lbr_xsave;
+
+ if (!xsave) {
+ intel_pmu_store_lbr(cpuc, NULL);
+ return;
+ }
+ xsaves(&xsave->xsave, XFEATURE_MASK_LBR);
+
+ intel_pmu_store_lbr(cpuc, xsave->lbr.entries);
+}
+
+void intel_pmu_lbr_read(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ /*
+ * Don't read when all LBRs users are using adaptive PEBS.
+ *
+ * This could be smarter and actually check the event,
+ * but this simple approach seems to work for now.
+ */
+ if (!cpuc->lbr_users || vlbr_exclude_host() ||
+ cpuc->lbr_users == cpuc->lbr_pebs_users)
+ return;
+
+ x86_pmu.lbr_read(cpuc);
+
+ intel_pmu_lbr_filter(cpuc);
+}
+
+/*
+ * SW filter is used:
+ * - in case there is no HW filter
+ * - in case the HW filter has errata or limitations
+ */
+static int intel_pmu_setup_sw_lbr_filter(struct perf_event *event)
+{
+ u64 br_type = event->attr.branch_sample_type;
+ int mask = 0;
+
+ if (br_type & PERF_SAMPLE_BRANCH_USER)
+ mask |= X86_BR_USER;
+
+ if (br_type & PERF_SAMPLE_BRANCH_KERNEL)
+ mask |= X86_BR_KERNEL;
+
+ /* we 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_ABORT_TX)
+ mask |= X86_BR_ABORT;
+
+ if (br_type & PERF_SAMPLE_BRANCH_IN_TX)
+ mask |= X86_BR_IN_TX;
+
+ if (br_type & PERF_SAMPLE_BRANCH_NO_TX)
+ mask |= X86_BR_NO_TX;
+
+ 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;
+ }
+
+ 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;
+
+ /*
+ * stash actual user request into reg, it may
+ * be used by fixup code for some CPU
+ */
+ event->hw.branch_reg.reg = mask;
+ return 0;
+}
+
+/*
+ * setup the HW LBR filter
+ * Used only when available, may not be enough to disambiguate
+ * all branches, may need the help of the SW filter
+ */
+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, v;
+ int i;
+
+ for (i = 0; i < PERF_SAMPLE_BRANCH_MAX_SHIFT; i++) {
+ if (!(br_type & (1ULL << i)))
+ continue;
+
+ v = x86_pmu.lbr_sel_map[i];
+ if (v == LBR_NOT_SUPP)
+ return -EOPNOTSUPP;
+
+ if (v != LBR_IGN)
+ mask |= v;
+ }
+
+ reg = &event->hw.branch_reg;
+ reg->idx = EXTRA_REG_LBR;
+
+ if (static_cpu_has(X86_FEATURE_ARCH_LBR)) {
+ reg->config = mask;
+
+ /*
+ * The Arch LBR HW can retrieve the common branch types
+ * from the LBR_INFO. It doesn't require the high overhead
+ * SW disassemble.
+ * Enable the branch type by default for the Arch LBR.
+ */
+ reg->reg |= X86_BR_TYPE_SAVE;
+ return 0;
+ }
+
+ /*
+ * 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)
+ * But the 10th bit LBR_CALL_STACK does not operate
+ * in suppress mode.
+ */
+ reg->config = mask ^ (x86_pmu.lbr_sel_mask & ~LBR_CALL_STACK);
+
+ if ((br_type & PERF_SAMPLE_BRANCH_NO_CYCLES) &&
+ (br_type & PERF_SAMPLE_BRANCH_NO_FLAGS) &&
+ x86_pmu.lbr_has_info)
+ reg->config |= LBR_NO_INFO;
+
+ return 0;
+}
+
+int intel_pmu_setup_lbr_filter(struct perf_event *event)
+{
+ int ret = 0;
+
+ /*
+ * no LBR on this PMU
+ */
+ if (!x86_pmu.lbr_nr)
+ return -EOPNOTSUPP;
+
+ /*
+ * setup SW LBR filter
+ */
+ ret = intel_pmu_setup_sw_lbr_filter(event);
+ if (ret)
+ return ret;
+
+ /*
+ * setup HW LBR filter, if any
+ */
+ if (x86_pmu.lbr_sel_map)
+ ret = intel_pmu_setup_hw_lbr_filter(event);
+
+ return ret;
+}
+
+enum {
+ ARCH_LBR_BR_TYPE_JCC = 0,
+ ARCH_LBR_BR_TYPE_NEAR_IND_JMP = 1,
+ ARCH_LBR_BR_TYPE_NEAR_REL_JMP = 2,
+ ARCH_LBR_BR_TYPE_NEAR_IND_CALL = 3,
+ ARCH_LBR_BR_TYPE_NEAR_REL_CALL = 4,
+ ARCH_LBR_BR_TYPE_NEAR_RET = 5,
+ ARCH_LBR_BR_TYPE_KNOWN_MAX = ARCH_LBR_BR_TYPE_NEAR_RET,
+
+ ARCH_LBR_BR_TYPE_MAP_MAX = 16,
+};
+
+static const int arch_lbr_br_type_map[ARCH_LBR_BR_TYPE_MAP_MAX] = {
+ [ARCH_LBR_BR_TYPE_JCC] = X86_BR_JCC,
+ [ARCH_LBR_BR_TYPE_NEAR_IND_JMP] = X86_BR_IND_JMP,
+ [ARCH_LBR_BR_TYPE_NEAR_REL_JMP] = X86_BR_JMP,
+ [ARCH_LBR_BR_TYPE_NEAR_IND_CALL] = X86_BR_IND_CALL,
+ [ARCH_LBR_BR_TYPE_NEAR_REL_CALL] = X86_BR_CALL,
+ [ARCH_LBR_BR_TYPE_NEAR_RET] = X86_BR_RET,
+};
+
+/*
+ * implement actual branch filter based on user demand.
+ * Hardware may not exactly satisfy that request, thus
+ * we need to inspect opcodes. Mismatched branches are
+ * discarded. Therefore, the number of branches returned
+ * in PERF_SAMPLE_BRANCH_STACK sample may vary.
+ */
+static void
+intel_pmu_lbr_filter(struct cpu_hw_events *cpuc)
+{
+ u64 from, to;
+ int br_sel = cpuc->br_sel;
+ int i, j, type, to_plm;
+ bool compress = false;
+
+ /* if sampling all branches, then nothing to filter */
+ if (((br_sel & X86_BR_ALL) == X86_BR_ALL) &&
+ ((br_sel & X86_BR_TYPE_SAVE) != X86_BR_TYPE_SAVE))
+ return;
+
+ for (i = 0; i < cpuc->lbr_stack.nr; i++) {
+
+ from = cpuc->lbr_entries[i].from;
+ to = cpuc->lbr_entries[i].to;
+ type = cpuc->lbr_entries[i].type;
+
+ /*
+ * Parse the branch type recorded in LBR_x_INFO MSR.
+ * Doesn't support OTHER_BRANCH decoding for now.
+ * OTHER_BRANCH branch type still rely on software decoding.
+ */
+ if (static_cpu_has(X86_FEATURE_ARCH_LBR) &&
+ type <= ARCH_LBR_BR_TYPE_KNOWN_MAX) {
+ to_plm = kernel_ip(to) ? X86_BR_KERNEL : X86_BR_USER;
+ type = arch_lbr_br_type_map[type] | to_plm;
+ } else
+ type = branch_type(from, to, cpuc->lbr_entries[i].abort);
+ if (type != X86_BR_NONE && (br_sel & X86_BR_ANYTX)) {
+ if (cpuc->lbr_entries[i].in_tx)
+ type |= X86_BR_IN_TX;
+ else
+ type |= X86_BR_NO_TX;
+ }
+
+ /* if type does not correspond, then discard */
+ if (type == X86_BR_NONE || (br_sel & type) != type) {
+ cpuc->lbr_entries[i].from = 0;
+ 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 entries with from=0 */
+ 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++;
+ }
+}
+
+void intel_pmu_store_pebs_lbrs(struct lbr_entry *lbr)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ /* Cannot get TOS for large PEBS and Arch LBR */
+ if (static_cpu_has(X86_FEATURE_ARCH_LBR) ||
+ (cpuc->n_pebs == cpuc->n_large_pebs))
+ cpuc->lbr_stack.hw_idx = -1ULL;
+ else
+ cpuc->lbr_stack.hw_idx = intel_pmu_lbr_tos();
+
+ intel_pmu_store_lbr(cpuc, lbr);
+ intel_pmu_lbr_filter(cpuc);
+}
+
+/*
+ * Map interface branch filters onto LBR filters
+ */
+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_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_SHIFT] = LBR_IND_CALL | LBR_IND_JMP,
+ [PERF_SAMPLE_BRANCH_COND_SHIFT] = LBR_JCC,
+ [PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT] = LBR_IND_JMP,
+};
+
+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,
+ [PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT] = LBR_IND_JMP,
+ [PERF_SAMPLE_BRANCH_CALL_SHIFT] = LBR_REL_CALL,
+};
+
+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,
+ [PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT] = LBR_IND_JMP,
+ [PERF_SAMPLE_BRANCH_CALL_SHIFT] = LBR_REL_CALL,
+};
+
+static int arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] = {
+ [PERF_SAMPLE_BRANCH_ANY_SHIFT] = ARCH_LBR_ANY,
+ [PERF_SAMPLE_BRANCH_USER_SHIFT] = ARCH_LBR_USER,
+ [PERF_SAMPLE_BRANCH_KERNEL_SHIFT] = ARCH_LBR_KERNEL,
+ [PERF_SAMPLE_BRANCH_HV_SHIFT] = LBR_IGN,
+ [PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT] = ARCH_LBR_RETURN |
+ ARCH_LBR_OTHER_BRANCH,
+ [PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT] = ARCH_LBR_REL_CALL |
+ ARCH_LBR_IND_CALL |
+ ARCH_LBR_OTHER_BRANCH,
+ [PERF_SAMPLE_BRANCH_IND_CALL_SHIFT] = ARCH_LBR_IND_CALL,
+ [PERF_SAMPLE_BRANCH_COND_SHIFT] = ARCH_LBR_JCC,
+ [PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT] = ARCH_LBR_REL_CALL |
+ ARCH_LBR_IND_CALL |
+ ARCH_LBR_RETURN |
+ ARCH_LBR_CALL_STACK,
+ [PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT] = ARCH_LBR_IND_JMP,
+ [PERF_SAMPLE_BRANCH_CALL_SHIFT] = ARCH_LBR_REL_CALL,
+};
+
+/* core */
+void __init intel_pmu_lbr_init_core(void)
+{
+ x86_pmu.lbr_nr = 4;
+ x86_pmu.lbr_tos = MSR_LBR_TOS;
+ x86_pmu.lbr_from = MSR_LBR_CORE_FROM;
+ x86_pmu.lbr_to = MSR_LBR_CORE_TO;
+
+ /*
+ * SW branch filter usage:
+ * - compensate for lack of HW filter
+ */
+}
+
+/* nehalem/westmere */
+void __init intel_pmu_lbr_init_nhm(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 = nhm_lbr_sel_map;
+
+ /*
+ * SW branch filter usage:
+ * - workaround LBR_SEL errata (see above)
+ * - support syscall, sysret capture.
+ * That requires LBR_FAR but that means far
+ * jmp need to be filtered out
+ */
+}
+
+/* sandy bridge */
+void __init intel_pmu_lbr_init_snb(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 = snb_lbr_sel_map;
+
+ /*
+ * SW branch filter usage:
+ * - support syscall, sysret capture.
+ * That requires LBR_FAR but that means far
+ * jmp need to be filtered out
+ */
+}
+
+static inline struct kmem_cache *
+create_lbr_kmem_cache(size_t size, size_t align)
+{
+ return kmem_cache_create("x86_lbr", size, align, 0, NULL);
+}
+
+/* haswell */
+void intel_pmu_lbr_init_hsw(void)
+{
+ size_t size = sizeof(struct x86_perf_task_context);
+
+ 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;
+
+ x86_get_pmu(smp_processor_id())->task_ctx_cache = create_lbr_kmem_cache(size, 0);
+}
+
+/* skylake */
+__init void intel_pmu_lbr_init_skl(void)
+{
+ size_t size = sizeof(struct x86_perf_task_context);
+
+ x86_pmu.lbr_nr = 32;
+ 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_info = MSR_LBR_INFO_0;
+
+ x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
+ x86_pmu.lbr_sel_map = hsw_lbr_sel_map;
+
+ x86_get_pmu(smp_processor_id())->task_ctx_cache = create_lbr_kmem_cache(size, 0);
+
+ /*
+ * SW branch filter usage:
+ * - support syscall, sysret capture.
+ * That requires LBR_FAR but that means far
+ * jmp need to be filtered out
+ */
+}
+
+/* atom */
+void __init intel_pmu_lbr_init_atom(void)
+{
+ /*
+ * only models starting at stepping 10 seems
+ * to have an operational LBR which can freeze
+ * on PMU interrupt
+ */
+ if (boot_cpu_data.x86_model == 28
+ && boot_cpu_data.x86_stepping < 10) {
+ pr_cont("LBR disabled due to erratum");
+ return;
+ }
+
+ x86_pmu.lbr_nr = 8;
+ x86_pmu.lbr_tos = MSR_LBR_TOS;
+ x86_pmu.lbr_from = MSR_LBR_CORE_FROM;
+ x86_pmu.lbr_to = MSR_LBR_CORE_TO;
+
+ /*
+ * SW branch filter usage:
+ * - compensate for lack of HW filter
+ */
+}
+
+/* slm */
+void __init intel_pmu_lbr_init_slm(void)
+{
+ x86_pmu.lbr_nr = 8;
+ x86_pmu.lbr_tos = MSR_LBR_TOS;
+ x86_pmu.lbr_from = MSR_LBR_CORE_FROM;
+ x86_pmu.lbr_to = MSR_LBR_CORE_TO;
+
+ x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
+ x86_pmu.lbr_sel_map = nhm_lbr_sel_map;
+
+ /*
+ * SW branch filter usage:
+ * - compensate for lack of HW filter
+ */
+ pr_cont("8-deep LBR, ");
+}
+
+/* Knights Landing */
+void intel_pmu_lbr_init_knl(void)
+{
+ x86_pmu.lbr_nr = 8;
+ 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 = snb_lbr_sel_map;
+
+ /* Knights Landing does have MISPREDICT bit */
+ if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_LIP)
+ x86_pmu.intel_cap.lbr_format = LBR_FORMAT_EIP_FLAGS;
+}
+
+void intel_pmu_lbr_init(void)
+{
+ switch (x86_pmu.intel_cap.lbr_format) {
+ case LBR_FORMAT_EIP_FLAGS2:
+ x86_pmu.lbr_has_tsx = 1;
+ x86_pmu.lbr_from_flags = 1;
+ if (lbr_from_signext_quirk_needed())
+ static_branch_enable(&lbr_from_quirk_key);
+ break;
+
+ case LBR_FORMAT_EIP_FLAGS:
+ x86_pmu.lbr_from_flags = 1;
+ break;
+
+ case LBR_FORMAT_INFO:
+ x86_pmu.lbr_has_tsx = 1;
+ fallthrough;
+ case LBR_FORMAT_INFO2:
+ x86_pmu.lbr_has_info = 1;
+ break;
+
+ case LBR_FORMAT_TIME:
+ x86_pmu.lbr_from_flags = 1;
+ x86_pmu.lbr_to_cycles = 1;
+ break;
+ }
+
+ if (x86_pmu.lbr_has_info) {
+ /*
+ * Only used in combination with baseline pebs.
+ */
+ static_branch_enable(&x86_lbr_mispred);
+ static_branch_enable(&x86_lbr_cycles);
+ }
+}
+
+/*
+ * LBR state size is variable based on the max number of registers.
+ * This calculates the expected state size, which should match
+ * what the hardware enumerates for the size of XFEATURE_LBR.
+ */
+static inline unsigned int get_lbr_state_size(void)
+{
+ return sizeof(struct arch_lbr_state) +
+ x86_pmu.lbr_nr * sizeof(struct lbr_entry);
+}
+
+static bool is_arch_lbr_xsave_available(void)
+{
+ if (!boot_cpu_has(X86_FEATURE_XSAVES))
+ return false;
+
+ /*
+ * Check the LBR state with the corresponding software structure.
+ * Disable LBR XSAVES support if the size doesn't match.
+ */
+ if (xfeature_size(XFEATURE_LBR) == 0)
+ return false;
+
+ if (WARN_ON(xfeature_size(XFEATURE_LBR) != get_lbr_state_size()))
+ return false;
+
+ return true;
+}
+
+void __init intel_pmu_arch_lbr_init(void)
+{
+ struct pmu *pmu = x86_get_pmu(smp_processor_id());
+ union cpuid28_eax eax;
+ union cpuid28_ebx ebx;
+ union cpuid28_ecx ecx;
+ unsigned int unused_edx;
+ bool arch_lbr_xsave;
+ size_t size;
+ u64 lbr_nr;
+
+ /* Arch LBR Capabilities */
+ cpuid(28, &eax.full, &ebx.full, &ecx.full, &unused_edx);
+
+ lbr_nr = fls(eax.split.lbr_depth_mask) * 8;
+ if (!lbr_nr)
+ goto clear_arch_lbr;
+
+ /* Apply the max depth of Arch LBR */
+ if (wrmsrl_safe(MSR_ARCH_LBR_DEPTH, lbr_nr))
+ goto clear_arch_lbr;
+
+ x86_pmu.lbr_depth_mask = eax.split.lbr_depth_mask;
+ x86_pmu.lbr_deep_c_reset = eax.split.lbr_deep_c_reset;
+ x86_pmu.lbr_lip = eax.split.lbr_lip;
+ x86_pmu.lbr_cpl = ebx.split.lbr_cpl;
+ x86_pmu.lbr_filter = ebx.split.lbr_filter;
+ x86_pmu.lbr_call_stack = ebx.split.lbr_call_stack;
+ x86_pmu.lbr_mispred = ecx.split.lbr_mispred;
+ x86_pmu.lbr_timed_lbr = ecx.split.lbr_timed_lbr;
+ x86_pmu.lbr_br_type = ecx.split.lbr_br_type;
+ x86_pmu.lbr_nr = lbr_nr;
+
+ if (x86_pmu.lbr_mispred)
+ static_branch_enable(&x86_lbr_mispred);
+ if (x86_pmu.lbr_timed_lbr)
+ static_branch_enable(&x86_lbr_cycles);
+ if (x86_pmu.lbr_br_type)
+ static_branch_enable(&x86_lbr_type);
+
+ arch_lbr_xsave = is_arch_lbr_xsave_available();
+ if (arch_lbr_xsave) {
+ size = sizeof(struct x86_perf_task_context_arch_lbr_xsave) +
+ get_lbr_state_size();
+ pmu->task_ctx_cache = create_lbr_kmem_cache(size,
+ XSAVE_ALIGNMENT);
+ }
+
+ if (!pmu->task_ctx_cache) {
+ arch_lbr_xsave = false;
+
+ size = sizeof(struct x86_perf_task_context_arch_lbr) +
+ lbr_nr * sizeof(struct lbr_entry);
+ pmu->task_ctx_cache = create_lbr_kmem_cache(size, 0);
+ }
+
+ x86_pmu.lbr_from = MSR_ARCH_LBR_FROM_0;
+ x86_pmu.lbr_to = MSR_ARCH_LBR_TO_0;
+ x86_pmu.lbr_info = MSR_ARCH_LBR_INFO_0;
+
+ /* LBR callstack requires both CPL and Branch Filtering support */
+ if (!x86_pmu.lbr_cpl ||
+ !x86_pmu.lbr_filter ||
+ !x86_pmu.lbr_call_stack)
+ arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT] = LBR_NOT_SUPP;
+
+ if (!x86_pmu.lbr_cpl) {
+ arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_USER_SHIFT] = LBR_NOT_SUPP;
+ arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_KERNEL_SHIFT] = LBR_NOT_SUPP;
+ } else if (!x86_pmu.lbr_filter) {
+ arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_ANY_SHIFT] = LBR_NOT_SUPP;
+ arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT] = LBR_NOT_SUPP;
+ arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT] = LBR_NOT_SUPP;
+ arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_IND_CALL_SHIFT] = LBR_NOT_SUPP;
+ arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_COND_SHIFT] = LBR_NOT_SUPP;
+ arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT] = LBR_NOT_SUPP;
+ arch_lbr_ctl_map[PERF_SAMPLE_BRANCH_CALL_SHIFT] = LBR_NOT_SUPP;
+ }
+
+ x86_pmu.lbr_ctl_mask = ARCH_LBR_CTL_MASK;
+ x86_pmu.lbr_ctl_map = arch_lbr_ctl_map;
+
+ if (!x86_pmu.lbr_cpl && !x86_pmu.lbr_filter)
+ x86_pmu.lbr_ctl_map = NULL;
+
+ x86_pmu.lbr_reset = intel_pmu_arch_lbr_reset;
+ if (arch_lbr_xsave) {
+ x86_pmu.lbr_save = intel_pmu_arch_lbr_xsaves;
+ x86_pmu.lbr_restore = intel_pmu_arch_lbr_xrstors;
+ x86_pmu.lbr_read = intel_pmu_arch_lbr_read_xsave;
+ pr_cont("XSAVE ");
+ } else {
+ x86_pmu.lbr_save = intel_pmu_arch_lbr_save;
+ x86_pmu.lbr_restore = intel_pmu_arch_lbr_restore;
+ x86_pmu.lbr_read = intel_pmu_arch_lbr_read;
+ }
+
+ pr_cont("Architectural LBR, ");
+
+ return;
+
+clear_arch_lbr:
+ setup_clear_cpu_cap(X86_FEATURE_ARCH_LBR);
+}
+
+/**
+ * x86_perf_get_lbr - get the LBR records information
+ *
+ * @lbr: the caller's memory to store the LBR records information
+ */
+void x86_perf_get_lbr(struct x86_pmu_lbr *lbr)
+{
+ int lbr_fmt = x86_pmu.intel_cap.lbr_format;
+
+ lbr->nr = x86_pmu.lbr_nr;
+ lbr->from = x86_pmu.lbr_from;
+ lbr->to = x86_pmu.lbr_to;
+ lbr->info = (lbr_fmt == LBR_FORMAT_INFO) ? x86_pmu.lbr_info : 0;
+}
+EXPORT_SYMBOL_GPL(x86_perf_get_lbr);
+
+struct event_constraint vlbr_constraint =
+ __EVENT_CONSTRAINT(INTEL_FIXED_VLBR_EVENT, (1ULL << INTEL_PMC_IDX_FIXED_VLBR),
+ FIXED_EVENT_FLAGS, 1, 0, PERF_X86_EVENT_LBR_SELECT);