[PATCH V3 4/5] powerpc, perf: Define BHRB generic functions, data and flags for POWER8

From: Anshuman Khandual
Date: Thu Apr 18 2013 - 08:27:38 EST


This patch populates BHRB specific data for power_pmu structure. It
also implements POWER8 specific BHRB filter and configuration functions.

Signed-off-by: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/perf/power8-pmu.c | 57 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 56 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/perf/power8-pmu.c b/arch/powerpc/perf/power8-pmu.c
index 106ae0b..153408c 100644
--- a/arch/powerpc/perf/power8-pmu.c
+++ b/arch/powerpc/perf/power8-pmu.c
@@ -109,6 +109,16 @@
#define EVENT_IS_MARKED (EVENT_MARKED_MASK << EVENT_MARKED_SHIFT)
#define EVENT_PSEL_MASK 0xff /* PMCxSEL value */

+/* MMCRA IFM bits - POWER8 */
+#define POWER8_MMCRA_IFM1 0x0000000040000000UL
+#define POWER8_MMCRA_IFM2 0x0000000080000000UL
+#define POWER8_MMCRA_IFM3 0x00000000C0000000UL
+
+#define ONLY_PLM \
+ (PERF_SAMPLE_BRANCH_USER |\
+ PERF_SAMPLE_BRANCH_KERNEL |\
+ PERF_SAMPLE_BRANCH_HV)
+
/*
* Layout of constraint bits:
*
@@ -428,6 +438,48 @@ static int power8_generic_events[] = {
[PERF_COUNT_HW_BRANCH_MISSES] = PM_BR_MPRED_CMPL,
};

+static u64 power8_bhrb_filter_map(u64 branch_sample_type)
+{
+ u64 pmu_bhrb_filter = 0;
+ u64 br_privilege = branch_sample_type & ONLY_PLM;
+
+ /* BHRB and regular PMU events share the same prvillege state
+ * filter configuration. BHRB is always recorded along with a
+ * regular PMU event. So privilege state filter criteria for BHRB
+ * and the companion PMU events has to be the same. As a default
+ * "perf record" tool sets all privillege bits ON when no filter
+ * criteria is provided in the command line. So as along as all
+ * privillege bits are ON or they are OFF, we are good to go.
+ */
+ if ((br_privilege != 7) && (br_privilege != 0))
+ return -1;
+
+ /* No branch filter requested */
+ if (branch_sample_type & PERF_SAMPLE_BRANCH_ANY)
+ return pmu_bhrb_filter;
+
+ /* Invalid branch filter options - HW does not support */
+ if (branch_sample_type & PERF_SAMPLE_BRANCH_ANY_RETURN)
+ return -1;
+
+ if (branch_sample_type & PERF_SAMPLE_BRANCH_IND_CALL)
+ return -1;
+
+ if (branch_sample_type & PERF_SAMPLE_BRANCH_ANY_CALL) {
+ pmu_bhrb_filter |= POWER8_MMCRA_IFM1;
+ return pmu_bhrb_filter;
+ }
+
+ /* Every thing else is unsupported */
+ return -1;
+}
+
+static void power8_config_bhrb(u64 pmu_bhrb_filter)
+{
+ /* Enable BHRB filter in PMU */
+ mtspr(SPRN_MMCRA, (mfspr(SPRN_MMCRA) | pmu_bhrb_filter));
+}
+
static struct power_pmu power8_pmu = {
.name = "POWER8",
.n_counter = 6,
@@ -435,12 +487,15 @@ static struct power_pmu power8_pmu = {
.add_fields = POWER8_ADD_FIELDS,
.test_adder = POWER8_TEST_ADDER,
.compute_mmcr = power8_compute_mmcr,
+ .config_bhrb = power8_config_bhrb,
+ .bhrb_filter_map = power8_bhrb_filter_map,
.get_constraint = power8_get_constraint,
.disable_pmc = power8_disable_pmc,
- .flags = PPMU_HAS_SSLOT | PPMU_HAS_SIER,
+ .flags = PPMU_HAS_SSLOT | PPMU_HAS_SIER | PPMU_BHRB,
.n_generic = ARRAY_SIZE(power8_generic_events),
.generic_events = power8_generic_events,
.attr_groups = power8_pmu_attr_groups,
+ .bhrb_nr = 32,
};

static int __init init_power8_pmu(void)
--
1.7.11.7

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