Re: [PATCH 2/4] perf arm_spe: Turn event name mappings into an array

James Clark
2026-04-02T09:48:47Z

On 02/04/2026 10:13 am, Leo Yan wrote:
> On Wed, Apr 01, 2026 at 03:25:50PM +0100, James Clark wrote:
>> This is so we can have a single function that prints events and can be
>> used with multiple mappings from different CPUs. Remove any bit that was
>> printed so that later we can print out the remaining unknown impdef
>> bits.
>>
>> No functional changes intended.
>>
>> Signed-off-by: James Clark <james.clark@linaro.org>
>> ---
>> .../util/arm-spe-decoder/arm-spe-pkt-decoder.c | 88 +++++++++++-----------
>> 1 file changed, 43 insertions(+), 45 deletions(-)
>>
>> diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
>> index 5769ba2f4140..c880b0dec3a1 100644
>> --- a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
>> +++ b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
>> @@ -276,6 +276,48 @@ static int arm_spe_pkt_out_string(int *err, char **buf_p, size_t *blen,
>> return ret;
>> }
>>
>> +struct ev_string {
>> + u8 event;
>> + const char *desc;
>> +};
>
> Maybe we can have more ambition to define a more general structure:
>
> struct packet_field_string {
> u64 bit_mask;
> u64 bit_val;
> const char *desc;
> };
>
> Thus, this also can be used by other bit fields decoding. We can do
> this now or if later refactor for other packets.
>
> Either way is fine for me:
>
> Reviewed-by: Leo Yan <leo.yan@arm.com>
>

Thanks. I think I'll leave it as it is, there's a risk of making it too
generic and then it doesn't fit any other use case anyway. We can always
add it later.

>> +
>> +static const struct ev_string common_ev_strings[] = {
>> + { .event = EV_EXCEPTION_GEN, .desc = "EXCEPTION-GEN" },
>> + { .event = EV_RETIRED, .desc = "RETIRED" },
>> + { .event = EV_L1D_ACCESS, .desc = "L1D-ACCESS" },
>> + { .event = EV_L1D_REFILL, .desc = "L1D-REFILL" },
>> + { .event = EV_TLB_ACCESS, .desc = "TLB-ACCESS" },
>> + { .event = EV_TLB_WALK, .desc = "TLB-REFILL" },
>> + { .event = EV_NOT_TAKEN, .desc = "NOT-TAKEN" },
>> + { .event = EV_MISPRED, .desc = "MISPRED" },
>> + { .event = EV_LLC_ACCESS, .desc = "LLC-ACCESS" },
>> + { .event = EV_LLC_MISS, .desc = "LLC-REFILL" },
>> + { .event = EV_REMOTE_ACCESS, .desc = "REMOTE-ACCESS" },
>> + { .event = EV_ALIGNMENT, .desc = "ALIGNMENT" },
>> + { .event = EV_TRANSACTIONAL, .desc = "TXN" },
>> + { .event = EV_PARTIAL_PREDICATE, .desc = "SVE-PARTIAL-PRED" },
>> + { .event = EV_EMPTY_PREDICATE, .desc = "SVE-EMPTY-PRED" },
>> + { .event = EV_L2D_ACCESS, .desc = "L2D-ACCESS" },
>> + { .event = EV_L2D_MISS, .desc = "L2D-MISS" },
>> + { .event = EV_CACHE_DATA_MODIFIED, .desc = "HITM" },
>> + { .event = EV_RECENTLY_FETCHED, .desc = "LFB" },
>> + { .event = EV_DATA_SNOOPED, .desc = "SNOOPED" },
>> + { .event = EV_STREAMING_SVE_MODE, .desc = "STREAMING-SVE" },
>> + { .event = EV_SMCU, .desc = "SMCU" },
>> + { .event = 0, .desc = NULL },
>> +};
>> +
>> +static u64 print_event_list(int *err, char **buf, size_t *buf_len,
>> + const struct ev_string *ev_strings, u64 payload)
>> +{
>> + for (const struct ev_string *ev = ev_strings; ev->desc != NULL; ev++) {
>> + if (payload & BIT(ev->event))
>> + arm_spe_pkt_out_string(err, buf, buf_len, " %s", ev->desc);
>> + payload &= ~BIT(ev->event);
>> + }
>> + return payload;
>> +}
>> +
>> static int arm_spe_pkt_desc_event(const struct arm_spe_pkt *packet,
>> char *buf, size_t buf_len)
>> {
>> @@ -283,51 +325,7 @@ static int arm_spe_pkt_desc_event(const struct arm_spe_pkt *packet,
>> int err = 0;
>>
>> arm_spe_pkt_out_string(&err, &buf, &buf_len, "EV");
>> -
>> - if (payload & BIT(EV_EXCEPTION_GEN))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " EXCEPTION-GEN");
>> - if (payload & BIT(EV_RETIRED))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " RETIRED");
>> - if (payload & BIT(EV_L1D_ACCESS))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " L1D-ACCESS");
>> - if (payload & BIT(EV_L1D_REFILL))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " L1D-REFILL");
>> - if (payload & BIT(EV_TLB_ACCESS))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " TLB-ACCESS");
>> - if (payload & BIT(EV_TLB_WALK))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " TLB-REFILL");
>> - if (payload & BIT(EV_NOT_TAKEN))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " NOT-TAKEN");
>> - if (payload & BIT(EV_MISPRED))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " MISPRED");
>> - if (payload & BIT(EV_LLC_ACCESS))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " LLC-ACCESS");
>> - if (payload & BIT(EV_LLC_MISS))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " LLC-REFILL");
>> - if (payload & BIT(EV_REMOTE_ACCESS))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " REMOTE-ACCESS");
>> - if (payload & BIT(EV_ALIGNMENT))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " ALIGNMENT");
>> - if (payload & BIT(EV_TRANSACTIONAL))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " TXN");
>> - if (payload & BIT(EV_PARTIAL_PREDICATE))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " SVE-PARTIAL-PRED");
>> - if (payload & BIT(EV_EMPTY_PREDICATE))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " SVE-EMPTY-PRED");
>> - if (payload & BIT(EV_L2D_ACCESS))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " L2D-ACCESS");
>> - if (payload & BIT(EV_L2D_MISS))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " L2D-MISS");
>> - if (payload & BIT(EV_CACHE_DATA_MODIFIED))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " HITM");
>> - if (payload & BIT(EV_RECENTLY_FETCHED))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " LFB");
>> - if (payload & BIT(EV_DATA_SNOOPED))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " SNOOPED");
>> - if (payload & BIT(EV_STREAMING_SVE_MODE))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " STREAMING-SVE");
>> - if (payload & BIT(EV_SMCU))
>> - arm_spe_pkt_out_string(&err, &buf, &buf_len, " SMCU");
>> + print_event_list(&err, &buf, &buf_len, common_ev_strings, payload);
>>
>> return err;
>> }
>>
>> --
>> 2.34.1
>>
>>