ARC: perf: Add some comments/debug stuff
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/arch/arc/include/asm/perf_event.h b/arch/arc/include/asm/perf_event.h
index cbf755e..1c45667 100644
--- a/arch/arc/include/asm/perf_event.h
+++ b/arch/arc/include/asm/perf_event.h
@@ -57,26 +57,7 @@
#define PERF_COUNT_ARC_HW_MAX (PERF_COUNT_HW_MAX + 6)
/*
- * The "generalized" performance events seem to really be a copy
- * of the available events on x86 processors; the mapping to ARC
- * events is not always possible 1-to-1. Fortunately, there doesn't
- * seem to be an exact definition for these events, so we can cheat
- * a bit where necessary.
- *
- * In particular, the following PERF events may behave a bit differently
- * compared to other architectures:
- *
- * PERF_COUNT_HW_CPU_CYCLES
- * Cycles not in halted state
- *
- * PERF_COUNT_HW_REF_CPU_CYCLES
- * Reference cycles not in halted state, same as PERF_COUNT_HW_CPU_CYCLES
- * for now as we don't do Dynamic Voltage/Frequency Scaling (yet)
- *
- * PERF_COUNT_HW_BUS_CYCLES
- * Unclear what this means, Intel uses 0x013c, which according to
- * their datasheet means "unhalted reference cycles". It sounds similar
- * to PERF_COUNT_HW_REF_CPU_CYCLES, and we use the same counter for it.
+ * Some ARC pct quirks:
*
* PERF_COUNT_HW_STALLED_CYCLES_BACKEND
* PERF_COUNT_HW_STALLED_CYCLES_FRONTEND
@@ -91,21 +72,35 @@
* Note that I$ cache misses aren't counted by either of the two!
*/
+/*
+ * ARC PCT has hardware conditions with fixed "names" but variable "indexes"
+ * (based on a specific RTL build)
+ * Below is the static map between perf generic/arc specific event_id and
+ * h/w condition names.
+ * At the time of probe, we loop thru each index and find it's name to
+ * complete the mapping of perf event_id to h/w index as latter is needed
+ * to program the counter really
+ */
static const char * const arc_pmu_ev_hw_map[] = {
+ /* count cycles */
[PERF_COUNT_HW_CPU_CYCLES] = "crun",
[PERF_COUNT_HW_REF_CPU_CYCLES] = "crun",
[PERF_COUNT_HW_BUS_CYCLES] = "crun",
- [PERF_COUNT_HW_INSTRUCTIONS] = "iall",
- [PERF_COUNT_HW_BRANCH_MISSES] = "bpfail",
- [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = "ijmp",
+
[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = "bflush",
[PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = "bstall",
- [PERF_COUNT_ARC_DCLM] = "dclm",
- [PERF_COUNT_ARC_DCSM] = "dcsm",
- [PERF_COUNT_ARC_ICM] = "icm",
- [PERF_COUNT_ARC_BPOK] = "bpok",
- [PERF_COUNT_ARC_EDTLB] = "edtlb",
- [PERF_COUNT_ARC_EITLB] = "eitlb",
+
+ /* counts condition */
+ [PERF_COUNT_HW_INSTRUCTIONS] = "iall",
+ [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = "ijmp",
+ [PERF_COUNT_ARC_BPOK] = "bpok", /* NP-NT, PT-T, PNT-NT */
+ [PERF_COUNT_HW_BRANCH_MISSES] = "bpfail", /* NP-T, PT-NT, PNT-T */
+
+ [PERF_COUNT_ARC_DCLM] = "dclm", /* D-cache Load Miss */
+ [PERF_COUNT_ARC_DCSM] = "dcsm", /* D-cache Store Miss */
+ [PERF_COUNT_ARC_ICM] = "icm", /* I-cache Miss */
+ [PERF_COUNT_ARC_EDTLB] = "edtlb", /* D-TLB Miss */
+ [PERF_COUNT_ARC_EITLB] = "eitlb", /* I-TLB Miss */
};
#define C(_x) PERF_COUNT_HW_CACHE_##_x