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ARC: perf: Add some comments/debug stuff

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Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This commit is contained in:
Vineet Gupta 2015-04-15 19:44:07 +05:30
parent 03c94fcf95
commit bde80c237e
2 changed files with 37 additions and 34 deletions
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53
arch/arc/include/asm/perf_event.h
View File

@ -57,26 +57,7 @@ struct arc_reg_cc_build {
#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 @@ struct arc_reg_cc_build {
* 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

18
arch/arc/kernel/perf_event.c
View File

@ -90,6 +90,10 @@ static int arc_pmu_cache_event(u64 config)
if (ret == CACHE_OP_UNSUPPORTED)
return -ENOENT;
pr_debug("init cache event: type/op/result %d/%d/%d with h/w %d \'%s\'\n",
cache_type, cache_op, cache_result, ret,
arc_pmu_ev_hw_map[ret]);
return ret;
}
@ -106,8 +110,9 @@ static int arc_pmu_event_init(struct perf_event *event)
if (arc_pmu->ev_hw_idx[event->attr.config] < 0)
return -ENOENT;
hwc->config = arc_pmu->ev_hw_idx[event->attr.config];
pr_debug("initializing event %d with cfg %d\n",
(int) event->attr.config, (int) hwc->config);
pr_debug("init event %d with h/w %d \'%s\'\n",
(int) event->attr.config, (int) hwc->config,
arc_pmu_ev_hw_map[event->attr.config]);
return 0;
case PERF_TYPE_HW_CACHE:
ret = arc_pmu_cache_event(event->attr.config);
@ -260,19 +265,22 @@ static int arc_pmu_device_probe(struct platform_device *pdev)
arc_pmu->n_counters, arc_pmu->counter_size, cc_bcr.c);
cc_name.str[8] = 0;
for (i = 0; i < PERF_COUNT_HW_MAX; i++)
for (i = 0; i < PERF_COUNT_ARC_HW_MAX; i++)
arc_pmu->ev_hw_idx[i] = -1;
/* loop thru all available h/w condition indexes */
for (j = 0; j < cc_bcr.c; j++) {
write_aux_reg(ARC_REG_CC_INDEX, j);
cc_name.indiv.word0 = read_aux_reg(ARC_REG_CC_NAME0);
cc_name.indiv.word1 = read_aux_reg(ARC_REG_CC_NAME1);
/* See if it has been mapped to a perf event_id */
for (i = 0; i < ARRAY_SIZE(arc_pmu_ev_hw_map); i++) {
if (arc_pmu_ev_hw_map[i] &&
!strcmp(arc_pmu_ev_hw_map[i], cc_name.str) &&
strlen(arc_pmu_ev_hw_map[i])) {
pr_debug("mapping %d to idx %d with name %s\n",
i, j, cc_name.str);
pr_debug("mapping perf event %2d to h/w event \'%8s\' (idx %d)\n",
i, cc_name.str, j);
arc_pmu->ev_hw_idx[i] = j;
}
}