Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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);