obj-$(CONFIG_CPU_SUP_AMD) += amd/iommu.o
endif
obj-$(CONFIG_CPU_SUP_INTEL) += intel/core.o intel/bts.o intel/cqm.o
-obj-$(CONFIG_CPU_SUP_INTEL) += intel/cstate.o intel/ds.o
+obj-$(CONFIG_CPU_SUP_INTEL) += intel/cstate.o intel/ds.o intel/lbr.o
--- /dev/null
+#include <linux/perf_event.h>
+#include <linux/types.h>
+
+#include <asm/perf_event.h>
+#include <asm/msr.h>
+#include <asm/insn.h>
+
+#include "../../kernel/cpu/perf_event.h"
+
+enum {
+ LBR_FORMAT_32 = 0x00,
+ LBR_FORMAT_LIP = 0x01,
+ LBR_FORMAT_EIP = 0x02,
+ LBR_FORMAT_EIP_FLAGS = 0x03,
+ LBR_FORMAT_EIP_FLAGS2 = 0x04,
+ LBR_FORMAT_INFO = 0x05,
+ LBR_FORMAT_MAX_KNOWN = LBR_FORMAT_INFO,
+};
+
+static enum {
+ LBR_EIP_FLAGS = 1,
+ LBR_TSX = 2,
+} lbr_desc[LBR_FORMAT_MAX_KNOWN + 1] = {
+ [LBR_FORMAT_EIP_FLAGS] = LBR_EIP_FLAGS,
+ [LBR_FORMAT_EIP_FLAGS2] = LBR_EIP_FLAGS | LBR_TSX,
+};
+
+/*
+ * 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 0x1ff /* 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 (1ULL << 63)
+#define LBR_FROM_FLAG_IN_TX (1ULL << 62)
+#define LBR_FROM_FLAG_ABORT (1ULL << 61)
+
+/*
+ * x86control flow change classification
+ * x86control flow changes include branches, interrupts, traps, faults
+ */
+enum {
+ X86_BR_NONE = 0, /* unknown */
+
+ X86_BR_USER = 1 << 0, /* branch target is user */
+ X86_BR_KERNEL = 1 << 1, /* branch target is kernel */
+
+ X86_BR_CALL = 1 << 2, /* call */
+ X86_BR_RET = 1 << 3, /* return */
+ X86_BR_SYSCALL = 1 << 4, /* syscall */
+ X86_BR_SYSRET = 1 << 5, /* syscall return */
+ X86_BR_INT = 1 << 6, /* sw interrupt */
+ X86_BR_IRET = 1 << 7, /* return from interrupt */
+ X86_BR_JCC = 1 << 8, /* conditional */
+ X86_BR_JMP = 1 << 9, /* jump */
+ X86_BR_IRQ = 1 << 10,/* hw interrupt or trap or fault */
+ X86_BR_IND_CALL = 1 << 11,/* indirect calls */
+ X86_BR_ABORT = 1 << 12,/* transaction abort */
+ X86_BR_IN_TX = 1 << 13,/* in transaction */
+ X86_BR_NO_TX = 1 << 14,/* not in transaction */
+ X86_BR_ZERO_CALL = 1 << 15,/* zero length call */
+ X86_BR_CALL_STACK = 1 << 16,/* call stack */
+ X86_BR_IND_JMP = 1 << 17,/* indirect jump */
+};
+
+#define X86_BR_PLM (X86_BR_USER | X86_BR_KERNEL)
+#define X86_BR_ANYTX (X86_BR_NO_TX | X86_BR_IN_TX)
+
+#define X86_BR_ANY \
+ (X86_BR_CALL |\
+ X86_BR_RET |\
+ X86_BR_SYSCALL |\
+ X86_BR_SYSRET |\
+ X86_BR_INT |\
+ X86_BR_IRET |\
+ X86_BR_JCC |\
+ X86_BR_JMP |\
+ X86_BR_IRQ |\
+ X86_BR_ABORT |\
+ X86_BR_IND_CALL |\
+ X86_BR_IND_JMP |\
+ X86_BR_ZERO_CALL)
+
+#define X86_BR_ALL (X86_BR_PLM | X86_BR_ANY)
+
+#define X86_BR_ANY_CALL \
+ (X86_BR_CALL |\
+ X86_BR_IND_CALL |\
+ X86_BR_ZERO_CALL |\
+ X86_BR_SYSCALL |\
+ X86_BR_IRQ |\
+ X86_BR_INT)
+
+static void intel_pmu_lbr_filter(struct cpu_hw_events *cpuc);
+
+/*
+ * 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 (!pmi && cpuc->lbr_sel)
+ wrmsrl(MSR_LBR_SELECT, lbr_select);
+
+ rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+ orig_debugctl = debugctl;
+ debugctl |= DEBUGCTLMSR_LBR;
+ /*
+ * LBR callstack does not work well with FREEZE_LBRS_ON_PMI.
+ * If FREEZE_LBRS_ON_PMI is set, PMI near call/return instructions
+ * may cause superfluous increase/decrease of LBR_TOS.
+ */
+ if (!(lbr_select & LBR_CALL_STACK))
+ debugctl |= DEBUGCTLMSR_FREEZE_LBRS_ON_PMI;
+ if (orig_debugctl != debugctl)
+ wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+}
+
+static void __intel_pmu_lbr_disable(void)
+{
+ u64 debugctl;
+
+ rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+ debugctl &= ~(DEBUGCTLMSR_LBR | DEBUGCTLMSR_FREEZE_LBRS_ON_PMI);
+ wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+}
+
+static 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);
+}
+
+static 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.intel_cap.lbr_format == LBR_FORMAT_INFO)
+ wrmsrl(MSR_LBR_INFO_0 + i, 0);
+ }
+}
+
+void intel_pmu_lbr_reset(void)
+{
+ if (!x86_pmu.lbr_nr)
+ return;
+
+ if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_32)
+ intel_pmu_lbr_reset_32();
+ else
+ intel_pmu_lbr_reset_64();
+}
+
+/*
+ * TOS = most recently recorded branch
+ */
+static inline u64 intel_pmu_lbr_tos(void)
+{
+ u64 tos;
+
+ rdmsrl(x86_pmu.lbr_tos, tos);
+ return tos;
+}
+
+enum {
+ LBR_NONE,
+ LBR_VALID,
+};
+
+static void __intel_pmu_lbr_restore(struct x86_perf_task_context *task_ctx)
+{
+ int i;
+ unsigned lbr_idx, mask;
+ u64 tos;
+
+ if (task_ctx->lbr_callstack_users == 0 ||
+ task_ctx->lbr_stack_state == LBR_NONE) {
+ intel_pmu_lbr_reset();
+ return;
+ }
+
+ mask = x86_pmu.lbr_nr - 1;
+ tos = task_ctx->tos;
+ for (i = 0; i < tos; i++) {
+ lbr_idx = (tos - i) & mask;
+ wrmsrl(x86_pmu.lbr_from + lbr_idx, task_ctx->lbr_from[i]);
+ wrmsrl(x86_pmu.lbr_to + lbr_idx, task_ctx->lbr_to[i]);
+ if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO)
+ wrmsrl(MSR_LBR_INFO_0 + lbr_idx, task_ctx->lbr_info[i]);
+ }
+ wrmsrl(x86_pmu.lbr_tos, tos);
+ task_ctx->lbr_stack_state = LBR_NONE;
+}
+
+static void __intel_pmu_lbr_save(struct x86_perf_task_context *task_ctx)
+{
+ int i;
+ unsigned lbr_idx, mask;
+ u64 tos;
+
+ if (task_ctx->lbr_callstack_users == 0) {
+ task_ctx->lbr_stack_state = LBR_NONE;
+ return;
+ }
+
+ mask = x86_pmu.lbr_nr - 1;
+ tos = intel_pmu_lbr_tos();
+ for (i = 0; i < tos; i++) {
+ lbr_idx = (tos - i) & mask;
+ rdmsrl(x86_pmu.lbr_from + lbr_idx, task_ctx->lbr_from[i]);
+ rdmsrl(x86_pmu.lbr_to + lbr_idx, task_ctx->lbr_to[i]);
+ if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO)
+ rdmsrl(MSR_LBR_INFO_0 + lbr_idx, task_ctx->lbr_info[i]);
+ }
+ task_ctx->tos = tos;
+ task_ctx->lbr_stack_state = LBR_VALID;
+}
+
+void intel_pmu_lbr_sched_task(struct perf_event_context *ctx, bool sched_in)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ struct x86_perf_task_context *task_ctx;
+
+ /*
+ * If LBR callstack feature is enabled and the stack was saved when
+ * the task was scheduled out, restore the stack. Otherwise flush
+ * the LBR stack.
+ */
+ task_ctx = ctx ? ctx->task_ctx_data : NULL;
+ if (task_ctx) {
+ if (sched_in) {
+ __intel_pmu_lbr_restore(task_ctx);
+ cpuc->lbr_context = ctx;
+ } else {
+ __intel_pmu_lbr_save(task_ctx);
+ }
+ return;
+ }
+
+ /*
+ * When sampling the branck stack in system-wide, it may be
+ * necessary to flush the stack on context switch. This happens
+ * when the branch stack does not tag its entries with the pid
+ * of the current task. Otherwise it becomes impossible to
+ * associate a branch entry with a task. This ambiguity is more
+ * likely to appear when the branch stack supports priv level
+ * filtering and the user sets it to monitor only at the user
+ * level (which could be a useful measurement in system-wide
+ * mode). In that case, the risk is high of having a branch
+ * stack with branch from multiple tasks.
+ */
+ if (sched_in) {
+ intel_pmu_lbr_reset();
+ cpuc->lbr_context = ctx;
+ }
+}
+
+static inline bool branch_user_callstack(unsigned br_sel)
+{
+ return (br_sel & X86_BR_USER) && (br_sel & X86_BR_CALL_STACK);
+}
+
+void intel_pmu_lbr_enable(struct perf_event *event)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ struct x86_perf_task_context *task_ctx;
+
+ if (!x86_pmu.lbr_nr)
+ return;
+
+ /*
+ * Reset the LBR stack if we changed task context to
+ * avoid data leaks.
+ */
+ if (event->ctx->task && cpuc->lbr_context != event->ctx) {
+ intel_pmu_lbr_reset();
+ cpuc->lbr_context = event->ctx;
+ }
+ cpuc->br_sel = event->hw.branch_reg.reg;
+
+ if (branch_user_callstack(cpuc->br_sel) && event->ctx &&
+ event->ctx->task_ctx_data) {
+ task_ctx = event->ctx->task_ctx_data;
+ task_ctx->lbr_callstack_users++;
+ }
+
+ cpuc->lbr_users++;
+ perf_sched_cb_inc(event->ctx->pmu);
+}
+
+void intel_pmu_lbr_disable(struct perf_event *event)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ struct x86_perf_task_context *task_ctx;
+
+ if (!x86_pmu.lbr_nr)
+ return;
+
+ if (branch_user_callstack(cpuc->br_sel) && event->ctx &&
+ event->ctx->task_ctx_data) {
+ task_ctx = event->ctx->task_ctx_data;
+ task_ctx->lbr_callstack_users--;
+ }
+
+ cpuc->lbr_users--;
+ WARN_ON_ONCE(cpuc->lbr_users < 0);
+ perf_sched_cb_dec(event->ctx->pmu);
+
+ if (cpuc->enabled && !cpuc->lbr_users) {
+ __intel_pmu_lbr_disable();
+ /* avoid stale pointer */
+ cpuc->lbr_context = NULL;
+ }
+}
+
+void intel_pmu_lbr_enable_all(bool pmi)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ if (cpuc->lbr_users)
+ __intel_pmu_lbr_enable(pmi);
+}
+
+void intel_pmu_lbr_disable_all(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ if (cpuc->lbr_users)
+ __intel_pmu_lbr_disable();
+}
+
+static void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc)
+{
+ unsigned long mask = x86_pmu.lbr_nr - 1;
+ 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);
+
+ cpuc->lbr_entries[i].from = msr_lastbranch.from;
+ cpuc->lbr_entries[i].to = msr_lastbranch.to;
+ cpuc->lbr_entries[i].mispred = 0;
+ cpuc->lbr_entries[i].predicted = 0;
+ cpuc->lbr_entries[i].reserved = 0;
+ }
+ cpuc->lbr_stack.nr = i;
+}
+
+/*
+ * 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.
+ */
+static void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc)
+{
+ bool need_info = false;
+ unsigned long mask = x86_pmu.lbr_nr - 1;
+ int lbr_format = x86_pmu.intel_cap.lbr_format;
+ 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)
+ num = tos;
+ }
+
+ 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;
+ int skip = 0;
+ u16 cycles = 0;
+ int lbr_flags = lbr_desc[lbr_format];
+
+ rdmsrl(x86_pmu.lbr_from + lbr_idx, from);
+ rdmsrl(x86_pmu.lbr_to + lbr_idx, to);
+
+ if (lbr_format == LBR_FORMAT_INFO && need_info) {
+ u64 info;
+
+ rdmsrl(MSR_LBR_INFO_0 + lbr_idx, info);
+ mis = !!(info & LBR_INFO_MISPRED);
+ pred = !mis;
+ in_tx = !!(info & LBR_INFO_IN_TX);
+ abort = !!(info & LBR_INFO_ABORT);
+ cycles = (info & LBR_INFO_CYCLES);
+ }
+ if (lbr_flags & LBR_EIP_FLAGS) {
+ mis = !!(from & LBR_FROM_FLAG_MISPRED);
+ pred = !mis;
+ skip = 1;
+ }
+ if (lbr_flags & LBR_TSX) {
+ in_tx = !!(from & LBR_FROM_FLAG_IN_TX);
+ abort = !!(from & LBR_FROM_FLAG_ABORT);
+ skip = 3;
+ }
+ from = (u64)((((s64)from) << skip) >> skip);
+
+ /*
+ * 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--;
+
+ cpuc->lbr_entries[out].from = from;
+ cpuc->lbr_entries[out].to = to;
+ cpuc->lbr_entries[out].mispred = mis;
+ cpuc->lbr_entries[out].predicted = pred;
+ cpuc->lbr_entries[out].in_tx = in_tx;
+ cpuc->lbr_entries[out].abort = abort;
+ cpuc->lbr_entries[out].cycles = cycles;
+ cpuc->lbr_entries[out].reserved = 0;
+ out++;
+ }
+ cpuc->lbr_stack.nr = out;
+}
+
+void intel_pmu_lbr_read(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ if (!cpuc->lbr_users)
+ return;
+
+ if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_32)
+ intel_pmu_lbr_read_32(cpuc);
+ else
+ intel_pmu_lbr_read_64(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;
+ /*
+ * 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;
+
+ /*
+ * The first 9 bits (LBR_SEL_MASK) in LBR_SELECT operate
+ * in suppress mode. So LBR_SELECT should be set to
+ * (~mask & LBR_SEL_MASK) | (mask & ~LBR_SEL_MASK)
+ */
+ reg->config = mask ^ x86_pmu.lbr_sel_mask;
+
+ if ((br_type & PERF_SAMPLE_BRANCH_NO_CYCLES) &&
+ (br_type & PERF_SAMPLE_BRANCH_NO_FLAGS) &&
+ (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_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;
+}
+
+/*
+ * return the type of control flow change at address "from"
+ * intruction is not necessarily a branch (in case of interrupt).
+ *
+ * The branch type returned also includes the priv level of the
+ * target of the control flow change (X86_BR_USER, X86_BR_KERNEL).
+ *
+ * If a branch type is unknown OR the instruction cannot be
+ * decoded (e.g., text page not present), then X86_BR_NONE is
+ * returned.
+ */
+static int branch_type(unsigned long from, unsigned long to, int abort)
+{
+ struct insn insn;
+ void *addr;
+ int bytes_read, bytes_left;
+ int ret = X86_BR_NONE;
+ int ext, to_plm, from_plm;
+ u8 buf[MAX_INSN_SIZE];
+ int is64 = 0;
+
+ to_plm = kernel_ip(to) ? X86_BR_KERNEL : X86_BR_USER;
+ from_plm = kernel_ip(from) ? X86_BR_KERNEL : X86_BR_USER;
+
+ /*
+ * maybe zero if lbr did not fill up after a reset by the time
+ * we get a PMU interrupt
+ */
+ if (from == 0 || to == 0)
+ return X86_BR_NONE;
+
+ if (abort)
+ return X86_BR_ABORT | to_plm;
+
+ if (from_plm == X86_BR_USER) {
+ /*
+ * can happen if measuring at the user level only
+ * and we interrupt in a kernel thread, e.g., idle.
+ */
+ if (!current->mm)
+ return X86_BR_NONE;
+
+ /* may fail if text not present */
+ bytes_left = copy_from_user_nmi(buf, (void __user *)from,
+ MAX_INSN_SIZE);
+ bytes_read = MAX_INSN_SIZE - bytes_left;
+ if (!bytes_read)
+ return X86_BR_NONE;
+
+ addr = buf;
+ } else {
+ /*
+ * The LBR logs any address in the IP, even if the IP just
+ * faulted. This means userspace can control the from address.
+ * Ensure we don't blindy read any address by validating it is
+ * a known text address.
+ */
+ if (kernel_text_address(from)) {
+ addr = (void *)from;
+ /*
+ * Assume we can get the maximum possible size
+ * when grabbing kernel data. This is not
+ * _strictly_ true since we could possibly be
+ * executing up next to a memory hole, but
+ * it is very unlikely to be a problem.
+ */
+ bytes_read = MAX_INSN_SIZE;
+ } else {
+ return X86_BR_NONE;
+ }
+ }
+
+ /*
+ * decoder needs to know the ABI especially
+ * on 64-bit systems running 32-bit apps
+ */
+#ifdef CONFIG_X86_64
+ is64 = kernel_ip((unsigned long)addr) || !test_thread_flag(TIF_IA32);
+#endif
+ insn_init(&insn, addr, bytes_read, is64);
+ insn_get_opcode(&insn);
+ if (!insn.opcode.got)
+ return X86_BR_ABORT;
+
+ switch (insn.opcode.bytes[0]) {
+ case 0xf:
+ switch (insn.opcode.bytes[1]) {
+ case 0x05: /* syscall */
+ case 0x34: /* sysenter */
+ ret = X86_BR_SYSCALL;
+ break;
+ case 0x07: /* sysret */
+ case 0x35: /* sysexit */
+ ret = X86_BR_SYSRET;
+ break;
+ case 0x80 ... 0x8f: /* conditional */
+ ret = X86_BR_JCC;
+ break;
+ default:
+ ret = X86_BR_NONE;
+ }
+ break;
+ case 0x70 ... 0x7f: /* conditional */
+ ret = X86_BR_JCC;
+ break;
+ case 0xc2: /* near ret */
+ case 0xc3: /* near ret */
+ case 0xca: /* far ret */
+ case 0xcb: /* far ret */
+ ret = X86_BR_RET;
+ break;
+ case 0xcf: /* iret */
+ ret = X86_BR_IRET;
+ break;
+ case 0xcc ... 0xce: /* int */
+ ret = X86_BR_INT;
+ break;
+ case 0xe8: /* call near rel */
+ insn_get_immediate(&insn);
+ if (insn.immediate1.value == 0) {
+ /* zero length call */
+ ret = X86_BR_ZERO_CALL;
+ break;
+ }
+ case 0x9a: /* call far absolute */
+ ret = X86_BR_CALL;
+ break;
+ case 0xe0 ... 0xe3: /* loop jmp */
+ ret = X86_BR_JCC;
+ break;
+ case 0xe9 ... 0xeb: /* jmp */
+ ret = X86_BR_JMP;
+ break;
+ case 0xff: /* call near absolute, call far absolute ind */
+ insn_get_modrm(&insn);
+ ext = (insn.modrm.bytes[0] >> 3) & 0x7;
+ switch (ext) {
+ case 2: /* near ind call */
+ case 3: /* far ind call */
+ ret = X86_BR_IND_CALL;
+ break;
+ case 4:
+ case 5:
+ ret = X86_BR_IND_JMP;
+ break;
+ }
+ break;
+ default:
+ ret = X86_BR_NONE;
+ }
+ /*
+ * interrupts, traps, faults (and thus ring transition) may
+ * occur on any instructions. Thus, to classify them correctly,
+ * we need to first look at the from and to priv levels. If they
+ * are different and to is in the kernel, then it indicates
+ * a ring transition. If the from instruction is not a ring
+ * transition instr (syscall, systenter, int), then it means
+ * it was a irq, trap or fault.
+ *
+ * we have no way of detecting kernel to kernel faults.
+ */
+ if (from_plm == X86_BR_USER && to_plm == X86_BR_KERNEL
+ && ret != X86_BR_SYSCALL && ret != X86_BR_INT)
+ ret = X86_BR_IRQ;
+
+ /*
+ * branch priv level determined by target as
+ * is done by HW when LBR_SELECT is implemented
+ */
+ if (ret != X86_BR_NONE)
+ ret |= to_plm;
+
+ return 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;
+ bool compress = false;
+
+ /* if sampling all branches, then nothing to filter */
+ if ((br_sel & X86_BR_ALL) == X86_BR_ALL)
+ return;
+
+ for (i = 0; i < cpuc->lbr_stack.nr; i++) {
+
+ from = cpuc->lbr_entries[i].from;
+ to = cpuc->lbr_entries[i].to;
+
+ 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 (!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++;
+ }
+}
+
+/*
+ * 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,
+};
+
+/* 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
+ */
+ pr_cont("4-deep LBR, ");
+}
+
+/* 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
+ */
+ pr_cont("16-deep LBR, ");
+}
+
+/* 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
+ */
+ pr_cont("16-deep LBR, ");
+}
+
+/* haswell */
+void intel_pmu_lbr_init_hsw(void)
+{
+ x86_pmu.lbr_nr = 16;
+ x86_pmu.lbr_tos = MSR_LBR_TOS;
+ x86_pmu.lbr_from = MSR_LBR_NHM_FROM;
+ x86_pmu.lbr_to = MSR_LBR_NHM_TO;
+
+ x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
+ x86_pmu.lbr_sel_map = hsw_lbr_sel_map;
+
+ pr_cont("16-deep LBR, ");
+}
+
+/* skylake */
+__init void intel_pmu_lbr_init_skl(void)
+{
+ 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_sel_mask = LBR_SEL_MASK;
+ x86_pmu.lbr_sel_map = hsw_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
+ */
+ pr_cont("32-deep LBR, ");
+}
+
+/* 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_mask < 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
+ */
+ 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;
+
+ pr_cont("8-deep LBR, ");
+}
ifdef CONFIG_PERF_EVENTS
obj-$(CONFIG_CPU_SUP_INTEL) += perf_event_p6.o perf_event_knc.o perf_event_p4.o
-obj-$(CONFIG_CPU_SUP_INTEL) += perf_event_intel_lbr.o
obj-$(CONFIG_CPU_SUP_INTEL) += perf_event_intel_rapl.o
obj-$(CONFIG_CPU_SUP_INTEL) += perf_event_intel_pt.o
+++ /dev/null
-#include <linux/perf_event.h>
-#include <linux/types.h>
-
-#include <asm/perf_event.h>
-#include <asm/msr.h>
-#include <asm/insn.h>
-
-#include "perf_event.h"
-
-enum {
- LBR_FORMAT_32 = 0x00,
- LBR_FORMAT_LIP = 0x01,
- LBR_FORMAT_EIP = 0x02,
- LBR_FORMAT_EIP_FLAGS = 0x03,
- LBR_FORMAT_EIP_FLAGS2 = 0x04,
- LBR_FORMAT_INFO = 0x05,
- LBR_FORMAT_MAX_KNOWN = LBR_FORMAT_INFO,
-};
-
-static enum {
- LBR_EIP_FLAGS = 1,
- LBR_TSX = 2,
-} lbr_desc[LBR_FORMAT_MAX_KNOWN + 1] = {
- [LBR_FORMAT_EIP_FLAGS] = LBR_EIP_FLAGS,
- [LBR_FORMAT_EIP_FLAGS2] = LBR_EIP_FLAGS | LBR_TSX,
-};
-
-/*
- * 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 0x1ff /* 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 (1ULL << 63)
-#define LBR_FROM_FLAG_IN_TX (1ULL << 62)
-#define LBR_FROM_FLAG_ABORT (1ULL << 61)
-
-/*
- * x86control flow change classification
- * x86control flow changes include branches, interrupts, traps, faults
- */
-enum {
- X86_BR_NONE = 0, /* unknown */
-
- X86_BR_USER = 1 << 0, /* branch target is user */
- X86_BR_KERNEL = 1 << 1, /* branch target is kernel */
-
- X86_BR_CALL = 1 << 2, /* call */
- X86_BR_RET = 1 << 3, /* return */
- X86_BR_SYSCALL = 1 << 4, /* syscall */
- X86_BR_SYSRET = 1 << 5, /* syscall return */
- X86_BR_INT = 1 << 6, /* sw interrupt */
- X86_BR_IRET = 1 << 7, /* return from interrupt */
- X86_BR_JCC = 1 << 8, /* conditional */
- X86_BR_JMP = 1 << 9, /* jump */
- X86_BR_IRQ = 1 << 10,/* hw interrupt or trap or fault */
- X86_BR_IND_CALL = 1 << 11,/* indirect calls */
- X86_BR_ABORT = 1 << 12,/* transaction abort */
- X86_BR_IN_TX = 1 << 13,/* in transaction */
- X86_BR_NO_TX = 1 << 14,/* not in transaction */
- X86_BR_ZERO_CALL = 1 << 15,/* zero length call */
- X86_BR_CALL_STACK = 1 << 16,/* call stack */
- X86_BR_IND_JMP = 1 << 17,/* indirect jump */
-};
-
-#define X86_BR_PLM (X86_BR_USER | X86_BR_KERNEL)
-#define X86_BR_ANYTX (X86_BR_NO_TX | X86_BR_IN_TX)
-
-#define X86_BR_ANY \
- (X86_BR_CALL |\
- X86_BR_RET |\
- X86_BR_SYSCALL |\
- X86_BR_SYSRET |\
- X86_BR_INT |\
- X86_BR_IRET |\
- X86_BR_JCC |\
- X86_BR_JMP |\
- X86_BR_IRQ |\
- X86_BR_ABORT |\
- X86_BR_IND_CALL |\
- X86_BR_IND_JMP |\
- X86_BR_ZERO_CALL)
-
-#define X86_BR_ALL (X86_BR_PLM | X86_BR_ANY)
-
-#define X86_BR_ANY_CALL \
- (X86_BR_CALL |\
- X86_BR_IND_CALL |\
- X86_BR_ZERO_CALL |\
- X86_BR_SYSCALL |\
- X86_BR_IRQ |\
- X86_BR_INT)
-
-static void intel_pmu_lbr_filter(struct cpu_hw_events *cpuc);
-
-/*
- * 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 (!pmi && cpuc->lbr_sel)
- wrmsrl(MSR_LBR_SELECT, lbr_select);
-
- rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
- orig_debugctl = debugctl;
- debugctl |= DEBUGCTLMSR_LBR;
- /*
- * LBR callstack does not work well with FREEZE_LBRS_ON_PMI.
- * If FREEZE_LBRS_ON_PMI is set, PMI near call/return instructions
- * may cause superfluous increase/decrease of LBR_TOS.
- */
- if (!(lbr_select & LBR_CALL_STACK))
- debugctl |= DEBUGCTLMSR_FREEZE_LBRS_ON_PMI;
- if (orig_debugctl != debugctl)
- wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
-}
-
-static void __intel_pmu_lbr_disable(void)
-{
- u64 debugctl;
-
- rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
- debugctl &= ~(DEBUGCTLMSR_LBR | DEBUGCTLMSR_FREEZE_LBRS_ON_PMI);
- wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
-}
-
-static 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);
-}
-
-static 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.intel_cap.lbr_format == LBR_FORMAT_INFO)
- wrmsrl(MSR_LBR_INFO_0 + i, 0);
- }
-}
-
-void intel_pmu_lbr_reset(void)
-{
- if (!x86_pmu.lbr_nr)
- return;
-
- if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_32)
- intel_pmu_lbr_reset_32();
- else
- intel_pmu_lbr_reset_64();
-}
-
-/*
- * TOS = most recently recorded branch
- */
-static inline u64 intel_pmu_lbr_tos(void)
-{
- u64 tos;
-
- rdmsrl(x86_pmu.lbr_tos, tos);
- return tos;
-}
-
-enum {
- LBR_NONE,
- LBR_VALID,
-};
-
-static void __intel_pmu_lbr_restore(struct x86_perf_task_context *task_ctx)
-{
- int i;
- unsigned lbr_idx, mask;
- u64 tos;
-
- if (task_ctx->lbr_callstack_users == 0 ||
- task_ctx->lbr_stack_state == LBR_NONE) {
- intel_pmu_lbr_reset();
- return;
- }
-
- mask = x86_pmu.lbr_nr - 1;
- tos = task_ctx->tos;
- for (i = 0; i < tos; i++) {
- lbr_idx = (tos - i) & mask;
- wrmsrl(x86_pmu.lbr_from + lbr_idx, task_ctx->lbr_from[i]);
- wrmsrl(x86_pmu.lbr_to + lbr_idx, task_ctx->lbr_to[i]);
- if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO)
- wrmsrl(MSR_LBR_INFO_0 + lbr_idx, task_ctx->lbr_info[i]);
- }
- wrmsrl(x86_pmu.lbr_tos, tos);
- task_ctx->lbr_stack_state = LBR_NONE;
-}
-
-static void __intel_pmu_lbr_save(struct x86_perf_task_context *task_ctx)
-{
- int i;
- unsigned lbr_idx, mask;
- u64 tos;
-
- if (task_ctx->lbr_callstack_users == 0) {
- task_ctx->lbr_stack_state = LBR_NONE;
- return;
- }
-
- mask = x86_pmu.lbr_nr - 1;
- tos = intel_pmu_lbr_tos();
- for (i = 0; i < tos; i++) {
- lbr_idx = (tos - i) & mask;
- rdmsrl(x86_pmu.lbr_from + lbr_idx, task_ctx->lbr_from[i]);
- rdmsrl(x86_pmu.lbr_to + lbr_idx, task_ctx->lbr_to[i]);
- if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_INFO)
- rdmsrl(MSR_LBR_INFO_0 + lbr_idx, task_ctx->lbr_info[i]);
- }
- task_ctx->tos = tos;
- task_ctx->lbr_stack_state = LBR_VALID;
-}
-
-void intel_pmu_lbr_sched_task(struct perf_event_context *ctx, bool sched_in)
-{
- struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
- struct x86_perf_task_context *task_ctx;
-
- /*
- * If LBR callstack feature is enabled and the stack was saved when
- * the task was scheduled out, restore the stack. Otherwise flush
- * the LBR stack.
- */
- task_ctx = ctx ? ctx->task_ctx_data : NULL;
- if (task_ctx) {
- if (sched_in) {
- __intel_pmu_lbr_restore(task_ctx);
- cpuc->lbr_context = ctx;
- } else {
- __intel_pmu_lbr_save(task_ctx);
- }
- return;
- }
-
- /*
- * When sampling the branck stack in system-wide, it may be
- * necessary to flush the stack on context switch. This happens
- * when the branch stack does not tag its entries with the pid
- * of the current task. Otherwise it becomes impossible to
- * associate a branch entry with a task. This ambiguity is more
- * likely to appear when the branch stack supports priv level
- * filtering and the user sets it to monitor only at the user
- * level (which could be a useful measurement in system-wide
- * mode). In that case, the risk is high of having a branch
- * stack with branch from multiple tasks.
- */
- if (sched_in) {
- intel_pmu_lbr_reset();
- cpuc->lbr_context = ctx;
- }
-}
-
-static inline bool branch_user_callstack(unsigned br_sel)
-{
- return (br_sel & X86_BR_USER) && (br_sel & X86_BR_CALL_STACK);
-}
-
-void intel_pmu_lbr_enable(struct perf_event *event)
-{
- struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
- struct x86_perf_task_context *task_ctx;
-
- if (!x86_pmu.lbr_nr)
- return;
-
- /*
- * Reset the LBR stack if we changed task context to
- * avoid data leaks.
- */
- if (event->ctx->task && cpuc->lbr_context != event->ctx) {
- intel_pmu_lbr_reset();
- cpuc->lbr_context = event->ctx;
- }
- cpuc->br_sel = event->hw.branch_reg.reg;
-
- if (branch_user_callstack(cpuc->br_sel) && event->ctx &&
- event->ctx->task_ctx_data) {
- task_ctx = event->ctx->task_ctx_data;
- task_ctx->lbr_callstack_users++;
- }
-
- cpuc->lbr_users++;
- perf_sched_cb_inc(event->ctx->pmu);
-}
-
-void intel_pmu_lbr_disable(struct perf_event *event)
-{
- struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
- struct x86_perf_task_context *task_ctx;
-
- if (!x86_pmu.lbr_nr)
- return;
-
- if (branch_user_callstack(cpuc->br_sel) && event->ctx &&
- event->ctx->task_ctx_data) {
- task_ctx = event->ctx->task_ctx_data;
- task_ctx->lbr_callstack_users--;
- }
-
- cpuc->lbr_users--;
- WARN_ON_ONCE(cpuc->lbr_users < 0);
- perf_sched_cb_dec(event->ctx->pmu);
-
- if (cpuc->enabled && !cpuc->lbr_users) {
- __intel_pmu_lbr_disable();
- /* avoid stale pointer */
- cpuc->lbr_context = NULL;
- }
-}
-
-void intel_pmu_lbr_enable_all(bool pmi)
-{
- struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
-
- if (cpuc->lbr_users)
- __intel_pmu_lbr_enable(pmi);
-}
-
-void intel_pmu_lbr_disable_all(void)
-{
- struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
-
- if (cpuc->lbr_users)
- __intel_pmu_lbr_disable();
-}
-
-static void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc)
-{
- unsigned long mask = x86_pmu.lbr_nr - 1;
- 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);
-
- cpuc->lbr_entries[i].from = msr_lastbranch.from;
- cpuc->lbr_entries[i].to = msr_lastbranch.to;
- cpuc->lbr_entries[i].mispred = 0;
- cpuc->lbr_entries[i].predicted = 0;
- cpuc->lbr_entries[i].reserved = 0;
- }
- cpuc->lbr_stack.nr = i;
-}
-
-/*
- * 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.
- */
-static void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc)
-{
- bool need_info = false;
- unsigned long mask = x86_pmu.lbr_nr - 1;
- int lbr_format = x86_pmu.intel_cap.lbr_format;
- 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)
- num = tos;
- }
-
- 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;
- int skip = 0;
- u16 cycles = 0;
- int lbr_flags = lbr_desc[lbr_format];
-
- rdmsrl(x86_pmu.lbr_from + lbr_idx, from);
- rdmsrl(x86_pmu.lbr_to + lbr_idx, to);
-
- if (lbr_format == LBR_FORMAT_INFO && need_info) {
- u64 info;
-
- rdmsrl(MSR_LBR_INFO_0 + lbr_idx, info);
- mis = !!(info & LBR_INFO_MISPRED);
- pred = !mis;
- in_tx = !!(info & LBR_INFO_IN_TX);
- abort = !!(info & LBR_INFO_ABORT);
- cycles = (info & LBR_INFO_CYCLES);
- }
- if (lbr_flags & LBR_EIP_FLAGS) {
- mis = !!(from & LBR_FROM_FLAG_MISPRED);
- pred = !mis;
- skip = 1;
- }
- if (lbr_flags & LBR_TSX) {
- in_tx = !!(from & LBR_FROM_FLAG_IN_TX);
- abort = !!(from & LBR_FROM_FLAG_ABORT);
- skip = 3;
- }
- from = (u64)((((s64)from) << skip) >> skip);
-
- /*
- * 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--;
-
- cpuc->lbr_entries[out].from = from;
- cpuc->lbr_entries[out].to = to;
- cpuc->lbr_entries[out].mispred = mis;
- cpuc->lbr_entries[out].predicted = pred;
- cpuc->lbr_entries[out].in_tx = in_tx;
- cpuc->lbr_entries[out].abort = abort;
- cpuc->lbr_entries[out].cycles = cycles;
- cpuc->lbr_entries[out].reserved = 0;
- out++;
- }
- cpuc->lbr_stack.nr = out;
-}
-
-void intel_pmu_lbr_read(void)
-{
- struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
-
- if (!cpuc->lbr_users)
- return;
-
- if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_32)
- intel_pmu_lbr_read_32(cpuc);
- else
- intel_pmu_lbr_read_64(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;
- /*
- * 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;
-
- /*
- * The first 9 bits (LBR_SEL_MASK) in LBR_SELECT operate
- * in suppress mode. So LBR_SELECT should be set to
- * (~mask & LBR_SEL_MASK) | (mask & ~LBR_SEL_MASK)
- */
- reg->config = mask ^ x86_pmu.lbr_sel_mask;
-
- if ((br_type & PERF_SAMPLE_BRANCH_NO_CYCLES) &&
- (br_type & PERF_SAMPLE_BRANCH_NO_FLAGS) &&
- (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_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;
-}
-
-/*
- * return the type of control flow change at address "from"
- * intruction is not necessarily a branch (in case of interrupt).
- *
- * The branch type returned also includes the priv level of the
- * target of the control flow change (X86_BR_USER, X86_BR_KERNEL).
- *
- * If a branch type is unknown OR the instruction cannot be
- * decoded (e.g., text page not present), then X86_BR_NONE is
- * returned.
- */
-static int branch_type(unsigned long from, unsigned long to, int abort)
-{
- struct insn insn;
- void *addr;
- int bytes_read, bytes_left;
- int ret = X86_BR_NONE;
- int ext, to_plm, from_plm;
- u8 buf[MAX_INSN_SIZE];
- int is64 = 0;
-
- to_plm = kernel_ip(to) ? X86_BR_KERNEL : X86_BR_USER;
- from_plm = kernel_ip(from) ? X86_BR_KERNEL : X86_BR_USER;
-
- /*
- * maybe zero if lbr did not fill up after a reset by the time
- * we get a PMU interrupt
- */
- if (from == 0 || to == 0)
- return X86_BR_NONE;
-
- if (abort)
- return X86_BR_ABORT | to_plm;
-
- if (from_plm == X86_BR_USER) {
- /*
- * can happen if measuring at the user level only
- * and we interrupt in a kernel thread, e.g., idle.
- */
- if (!current->mm)
- return X86_BR_NONE;
-
- /* may fail if text not present */
- bytes_left = copy_from_user_nmi(buf, (void __user *)from,
- MAX_INSN_SIZE);
- bytes_read = MAX_INSN_SIZE - bytes_left;
- if (!bytes_read)
- return X86_BR_NONE;
-
- addr = buf;
- } else {
- /*
- * The LBR logs any address in the IP, even if the IP just
- * faulted. This means userspace can control the from address.
- * Ensure we don't blindy read any address by validating it is
- * a known text address.
- */
- if (kernel_text_address(from)) {
- addr = (void *)from;
- /*
- * Assume we can get the maximum possible size
- * when grabbing kernel data. This is not
- * _strictly_ true since we could possibly be
- * executing up next to a memory hole, but
- * it is very unlikely to be a problem.
- */
- bytes_read = MAX_INSN_SIZE;
- } else {
- return X86_BR_NONE;
- }
- }
-
- /*
- * decoder needs to know the ABI especially
- * on 64-bit systems running 32-bit apps
- */
-#ifdef CONFIG_X86_64
- is64 = kernel_ip((unsigned long)addr) || !test_thread_flag(TIF_IA32);
-#endif
- insn_init(&insn, addr, bytes_read, is64);
- insn_get_opcode(&insn);
- if (!insn.opcode.got)
- return X86_BR_ABORT;
-
- switch (insn.opcode.bytes[0]) {
- case 0xf:
- switch (insn.opcode.bytes[1]) {
- case 0x05: /* syscall */
- case 0x34: /* sysenter */
- ret = X86_BR_SYSCALL;
- break;
- case 0x07: /* sysret */
- case 0x35: /* sysexit */
- ret = X86_BR_SYSRET;
- break;
- case 0x80 ... 0x8f: /* conditional */
- ret = X86_BR_JCC;
- break;
- default:
- ret = X86_BR_NONE;
- }
- break;
- case 0x70 ... 0x7f: /* conditional */
- ret = X86_BR_JCC;
- break;
- case 0xc2: /* near ret */
- case 0xc3: /* near ret */
- case 0xca: /* far ret */
- case 0xcb: /* far ret */
- ret = X86_BR_RET;
- break;
- case 0xcf: /* iret */
- ret = X86_BR_IRET;
- break;
- case 0xcc ... 0xce: /* int */
- ret = X86_BR_INT;
- break;
- case 0xe8: /* call near rel */
- insn_get_immediate(&insn);
- if (insn.immediate1.value == 0) {
- /* zero length call */
- ret = X86_BR_ZERO_CALL;
- break;
- }
- case 0x9a: /* call far absolute */
- ret = X86_BR_CALL;
- break;
- case 0xe0 ... 0xe3: /* loop jmp */
- ret = X86_BR_JCC;
- break;
- case 0xe9 ... 0xeb: /* jmp */
- ret = X86_BR_JMP;
- break;
- case 0xff: /* call near absolute, call far absolute ind */
- insn_get_modrm(&insn);
- ext = (insn.modrm.bytes[0] >> 3) & 0x7;
- switch (ext) {
- case 2: /* near ind call */
- case 3: /* far ind call */
- ret = X86_BR_IND_CALL;
- break;
- case 4:
- case 5:
- ret = X86_BR_IND_JMP;
- break;
- }
- break;
- default:
- ret = X86_BR_NONE;
- }
- /*
- * interrupts, traps, faults (and thus ring transition) may
- * occur on any instructions. Thus, to classify them correctly,
- * we need to first look at the from and to priv levels. If they
- * are different and to is in the kernel, then it indicates
- * a ring transition. If the from instruction is not a ring
- * transition instr (syscall, systenter, int), then it means
- * it was a irq, trap or fault.
- *
- * we have no way of detecting kernel to kernel faults.
- */
- if (from_plm == X86_BR_USER && to_plm == X86_BR_KERNEL
- && ret != X86_BR_SYSCALL && ret != X86_BR_INT)
- ret = X86_BR_IRQ;
-
- /*
- * branch priv level determined by target as
- * is done by HW when LBR_SELECT is implemented
- */
- if (ret != X86_BR_NONE)
- ret |= to_plm;
-
- return 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;
- bool compress = false;
-
- /* if sampling all branches, then nothing to filter */
- if ((br_sel & X86_BR_ALL) == X86_BR_ALL)
- return;
-
- for (i = 0; i < cpuc->lbr_stack.nr; i++) {
-
- from = cpuc->lbr_entries[i].from;
- to = cpuc->lbr_entries[i].to;
-
- 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 (!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++;
- }
-}
-
-/*
- * 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,
-};
-
-/* 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
- */
- pr_cont("4-deep LBR, ");
-}
-
-/* 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
- */
- pr_cont("16-deep LBR, ");
-}
-
-/* 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
- */
- pr_cont("16-deep LBR, ");
-}
-
-/* haswell */
-void intel_pmu_lbr_init_hsw(void)
-{
- x86_pmu.lbr_nr = 16;
- x86_pmu.lbr_tos = MSR_LBR_TOS;
- x86_pmu.lbr_from = MSR_LBR_NHM_FROM;
- x86_pmu.lbr_to = MSR_LBR_NHM_TO;
-
- x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
- x86_pmu.lbr_sel_map = hsw_lbr_sel_map;
-
- pr_cont("16-deep LBR, ");
-}
-
-/* skylake */
-__init void intel_pmu_lbr_init_skl(void)
-{
- 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_sel_mask = LBR_SEL_MASK;
- x86_pmu.lbr_sel_map = hsw_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
- */
- pr_cont("32-deep LBR, ");
-}
-
-/* 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_mask < 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
- */
- 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;
-
- pr_cont("8-deep LBR, ");
-}
projects / cascardo / linux.git / commitdiff