perf/x86: Add Intel LBR mappings for PERF_SAMPLE_BRANCH filters

This patch adds the mappings from the generic PERF_SAMPLE_BRANCH_*
filters to the actual Intel x86LBR filters, whenever they exist.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1328826068-11713-6-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 101 insertions, 2 deletions

diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
index 6710a5116ebd..e54a063b2863 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -14,6 +14,49 @@ enum {
 };
 
 /*
+ * 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_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_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)
+
+/*
  * We only support LBR implementations that have FREEZE_LBRS_ON_PMI
  * otherwise it becomes near impossible to get a reliable stack.
  */
@@ -151,8 +194,6 @@ static void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc)
         cpuc->lbr_stack.nr = i;
 }
 
-#define LBR_FROM_FLAG_MISPRED  (1ULL << 63)
-
 /*
  * 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
@@ -200,26 +241,84 @@ void intel_pmu_lbr_read(void)
                 intel_pmu_lbr_read_64(cpuc);
 }
 
+/*
+ * Map interface branch filters onto LBR filters
+ */
+static const int nhm_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX] = {
+        [PERF_SAMPLE_BRANCH_ANY]        = LBR_ANY,
+        [PERF_SAMPLE_BRANCH_USER]       = LBR_USER,
+        [PERF_SAMPLE_BRANCH_KERNEL]     = LBR_KERNEL,
+        [PERF_SAMPLE_BRANCH_HV]         = LBR_IGN,
+        [PERF_SAMPLE_BRANCH_ANY_RETURN] = LBR_RETURN | LBR_REL_JMP
+                                        | LBR_IND_JMP | LBR_FAR,
+        /*
+         * NHM/WSM erratum: must include REL_JMP+IND_JMP to get CALL branches
+         */
+        [PERF_SAMPLE_BRANCH_ANY_CALL] =
+         LBR_REL_CALL | LBR_IND_CALL | LBR_REL_JMP | LBR_IND_JMP | LBR_FAR,
+        /*
+         * NHM/WSM erratum: must include IND_JMP to capture IND_CALL
+         */
+        [PERF_SAMPLE_BRANCH_IND_CALL] = LBR_IND_CALL | LBR_IND_JMP,
+};
+
+static const int snb_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX] = {
+        [PERF_SAMPLE_BRANCH_ANY]        = LBR_ANY,
+        [PERF_SAMPLE_BRANCH_USER]       = LBR_USER,
+        [PERF_SAMPLE_BRANCH_KERNEL]     = LBR_KERNEL,
+        [PERF_SAMPLE_BRANCH_HV]         = LBR_IGN,
+        [PERF_SAMPLE_BRANCH_ANY_RETURN] = LBR_RETURN | LBR_FAR,
+        [PERF_SAMPLE_BRANCH_ANY_CALL]   = LBR_REL_CALL | LBR_IND_CALL
+                                        | LBR_FAR,
+        [PERF_SAMPLE_BRANCH_IND_CALL]   = LBR_IND_CALL,
+};
+
+/* core */
 void 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;
+
+        pr_cont("4-deep LBR, ");
 }
 
+/* nehalem/westmere */
 void 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;
+
+        pr_cont("16-deep LBR, ");
 }
 
+/* sandy bridge */
+void 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;
+
+        pr_cont("16-deep LBR, ");
+}
+
+/* atom */
 void intel_pmu_lbr_init_atom(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;
+
+        pr_cont("8-deep LBR, ");
 }