Commit b6521ea2 authored by Mike Leach's avatar Mike Leach Committed by Arnaldo Carvalho de Melo
Browse files

perf cs-etm: Handle PERF_RECORD_AUX_OUTPUT_HW_ID packet 



When using dynamically assigned CoreSight trace IDs the drivers can output
the ID / CPU association as a PERF_RECORD_AUX_OUTPUT_HW_ID packet.

Update cs-etm decoder to handle this packet by setting the CPU/Trace ID
mapping.

Reviewed-by: default avatarJames Clark <james.clark@arm.com>
Signed-off-by: default avatarMike Leach <mike.leach@linaro.org>
Acked-by: default avatarSuzuki Poulouse <suzuki.poulose@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Darren Hart <darren@os.amperecomputing.com>
Cc: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230331055645.26918-2-mike.leach@linaro.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent e5fa5b41

tools/include/linux/coresight-pmu.h

+15 −0
Original line number Diff line number Diff line
@@ -31,6 +31,9 @@ 
 */

#define CORESIGHT_TRACE_ID_UNUSED_FLAG	BIT(31)



/* Value to set for unused trace ID values */

#define CORESIGHT_TRACE_ID_UNUSED_VAL	0x7F



/*

 * Below are the definition of bit offsets for perf option, and works as

 * arbitrary values for all ETM versions.
@@ -55,4 +58,16 @@ 
#define ETM4_CFG_BIT_RETSTK	12

#define ETM4_CFG_BIT_VMID_OPT	15



/*

 * Interpretation of the PERF_RECORD_AUX_OUTPUT_HW_ID payload.

 * Used to associate a CPU with the CoreSight Trace ID.

 * [07:00] - Trace ID - uses 8 bits to make value easy to read in file.

 * [59:08] - Unused (SBZ)

 * [63:60] - Version

 */

#define CS_AUX_HW_ID_TRACE_ID_MASK	GENMASK_ULL(7, 0)

#define CS_AUX_HW_ID_VERSION_MASK	GENMASK_ULL(63, 60)



#define CS_AUX_HW_ID_CURR_VERSION 0



#endif

tools/perf/util/cs-etm-decoder/cs-etm-decoder.c

+7 −0
Original line number Diff line number Diff line
@@ -668,6 +668,7 @@ cs_etm_decoder__create_etm_decoder(struct cs_etm_decoder_params *d_params, 
	switch (t_params->protocol) {

	case CS_ETM_PROTO_ETMV3:

	case CS_ETM_PROTO_PTM:

		csid = (t_params->etmv3.reg_idr & CORESIGHT_TRACE_ID_VAL_MASK);

		cs_etm_decoder__gen_etmv3_config(t_params, &config_etmv3);

		decoder->decoder_name = (t_params->protocol == CS_ETM_PROTO_ETMV3) ?

							OCSD_BUILTIN_DCD_ETMV3 :
@@ -675,11 +676,13 @@ cs_etm_decoder__create_etm_decoder(struct cs_etm_decoder_params *d_params, 
		trace_config = &config_etmv3;

		break;

	case CS_ETM_PROTO_ETMV4i:

		csid = (t_params->etmv4.reg_traceidr & CORESIGHT_TRACE_ID_VAL_MASK);

		cs_etm_decoder__gen_etmv4_config(t_params, &trace_config_etmv4);

		decoder->decoder_name = OCSD_BUILTIN_DCD_ETMV4I;

		trace_config = &trace_config_etmv4;

		break;

	case CS_ETM_PROTO_ETE:

		csid = (t_params->ete.reg_traceidr & CORESIGHT_TRACE_ID_VAL_MASK);

		cs_etm_decoder__gen_ete_config(t_params, &trace_config_ete);

		decoder->decoder_name = OCSD_BUILTIN_DCD_ETE;

		trace_config = &trace_config_ete;
@@ -688,6 +691,10 @@ cs_etm_decoder__create_etm_decoder(struct cs_etm_decoder_params *d_params, 
		return -1;

	}



	/* if the CPU has no trace ID associated, no decoder needed */

	if (csid == CORESIGHT_TRACE_ID_UNUSED_VAL)

		return 0;



	if (d_params->operation == CS_ETM_OPERATION_DECODE) {

		if (ocsd_dt_create_decoder(decoder->dcd_tree,

					   decoder->decoder_name,

tools/perf/util/cs-etm.c

+228 −18
Original line number Diff line number Diff line
@@ -220,6 +220,143 @@ static int cs_etm__map_trace_id(u8 trace_chan_id, u64 *cpu_metadata) 
	return 0;

}



static int cs_etm__metadata_get_trace_id(u8 *trace_chan_id, u64 *cpu_metadata)

{

	u64 cs_etm_magic = cpu_metadata[CS_ETM_MAGIC];



	switch (cs_etm_magic) {

	case __perf_cs_etmv3_magic:

		*trace_chan_id = (u8)(cpu_metadata[CS_ETM_ETMTRACEIDR] &

				      CORESIGHT_TRACE_ID_VAL_MASK);

		break;

	case __perf_cs_etmv4_magic:

	case __perf_cs_ete_magic:

		*trace_chan_id = (u8)(cpu_metadata[CS_ETMV4_TRCTRACEIDR] &

				      CORESIGHT_TRACE_ID_VAL_MASK);

		break;

	default:

		return -EINVAL;

	}

	return 0;

}



/*

 * update metadata trace ID from the value found in the AUX_HW_INFO packet.

 * This will also clear the CORESIGHT_TRACE_ID_UNUSED_FLAG flag if present.

 */

static int cs_etm__metadata_set_trace_id(u8 trace_chan_id, u64 *cpu_metadata)

{

	u64 cs_etm_magic = cpu_metadata[CS_ETM_MAGIC];



	switch (cs_etm_magic) {

	case __perf_cs_etmv3_magic:

		 cpu_metadata[CS_ETM_ETMTRACEIDR] = trace_chan_id;

		break;

	case __perf_cs_etmv4_magic:

	case __perf_cs_ete_magic:

		cpu_metadata[CS_ETMV4_TRCTRACEIDR] = trace_chan_id;

		break;



	default:

		return -EINVAL;

	}

	return 0;

}



/*

 * FIELD_GET (linux/bitfield.h) not available outside kernel code,

 * and the header contains too many dependencies to just copy over,

 * so roll our own based on the original

 */

#define __bf_shf(x) (__builtin_ffsll(x) - 1)

#define FIELD_GET(_mask, _reg)						\

	({								\

		(typeof(_mask))(((_reg) & (_mask)) >> __bf_shf(_mask)); \

	})



/*

 * Handle the PERF_RECORD_AUX_OUTPUT_HW_ID event.

 *

 * The payload associates the Trace ID and the CPU.

 * The routine is tolerant of seeing multiple packets with the same association,

 * but a CPU / Trace ID association changing during a session is an error.

 */

static int cs_etm__process_aux_output_hw_id(struct perf_session *session,

					    union perf_event *event)

{

	struct cs_etm_auxtrace *etm;

	struct perf_sample sample;

	struct int_node *inode;

	struct evsel *evsel;

	u64 *cpu_data;

	u64 hw_id;

	int cpu, version, err;

	u8 trace_chan_id, curr_chan_id;



	/* extract and parse the HW ID */

	hw_id = event->aux_output_hw_id.hw_id;

	version = FIELD_GET(CS_AUX_HW_ID_VERSION_MASK, hw_id);

	trace_chan_id = FIELD_GET(CS_AUX_HW_ID_TRACE_ID_MASK, hw_id);



	/* check that we can handle this version */

	if (version > CS_AUX_HW_ID_CURR_VERSION)

		return -EINVAL;



	/* get access to the etm metadata */

	etm = container_of(session->auxtrace, struct cs_etm_auxtrace, auxtrace);

	if (!etm || !etm->metadata)

		return -EINVAL;



	/* parse the sample to get the CPU */

	evsel = evlist__event2evsel(session->evlist, event);

	if (!evsel)

		return -EINVAL;

	err = evsel__parse_sample(evsel, event, &sample);

	if (err)

		return err;

	cpu = sample.cpu;

	if (cpu == -1) {

		/* no CPU in the sample - possibly recorded with an old version of perf */

		pr_err("CS_ETM: no CPU AUX_OUTPUT_HW_ID sample. Use compatible perf to record.");

		return -EINVAL;

	}



	/* See if the ID is mapped to a CPU, and it matches the current CPU */

	inode = intlist__find(traceid_list, trace_chan_id);

	if (inode) {

		cpu_data = inode->priv;

		if ((int)cpu_data[CS_ETM_CPU] != cpu) {

			pr_err("CS_ETM: map mismatch between HW_ID packet CPU and Trace ID\n");

			return -EINVAL;

		}



		/* check that the mapped ID matches */

		err = cs_etm__metadata_get_trace_id(&curr_chan_id, cpu_data);

		if (err)

			return err;

		if (curr_chan_id != trace_chan_id) {

			pr_err("CS_ETM: mismatch between CPU trace ID and HW_ID packet ID\n");

			return -EINVAL;

		}



		/* mapped and matched - return OK */

		return 0;

	}



	/* not one we've seen before - lets map it */

	cpu_data = etm->metadata[cpu];

	err = cs_etm__map_trace_id(trace_chan_id, cpu_data);

	if (err)

		return err;



	/*

	 * if we are picking up the association from the packet, need to plug

	 * the correct trace ID into the metadata for setting up decoders later.

	 */

	err = cs_etm__metadata_set_trace_id(trace_chan_id, cpu_data);

	return err;

}



void cs_etm__etmq_set_traceid_queue_timestamp(struct cs_etm_queue *etmq,

					      u8 trace_chan_id)

{
@@ -2668,11 +2805,16 @@ static int cs_etm__queue_aux_fragment(struct perf_session *session, off_t file_o 
	}



	/*

	 * In per-thread mode, CPU is set to -1, but TID will be set instead. See

	 * auxtrace_mmap_params__set_idx(). Return 'not found' if neither CPU nor TID match.

	 * In per-thread mode, auxtrace CPU is set to -1, but TID will be set instead. See

	 * auxtrace_mmap_params__set_idx(). However, the sample AUX event will contain a

	 * CPU as we set this always for the AUX_OUTPUT_HW_ID event.

	 * So now compare only TIDs if auxtrace CPU is -1, and CPUs if auxtrace CPU is not -1.

	 * Return 'not found' if mismatch.

	 */

	if ((auxtrace_event->cpu == (__u32) -1 && auxtrace_event->tid != sample->tid) ||

			auxtrace_event->cpu != sample->cpu)

	if (auxtrace_event->cpu == (__u32) -1) {

		if (auxtrace_event->tid != sample->tid)

			return 1;

	} else if (auxtrace_event->cpu != sample->cpu)

		return 1;



	if (aux_event->flags & PERF_AUX_FLAG_OVERWRITE) {
@@ -2721,6 +2863,17 @@ static int cs_etm__queue_aux_fragment(struct perf_session *session, off_t file_o 
	return 1;

}



static int cs_etm__process_aux_hw_id_cb(struct perf_session *session, union perf_event *event,

					u64 offset __maybe_unused, void *data __maybe_unused)

{

	/* look to handle PERF_RECORD_AUX_OUTPUT_HW_ID early to ensure decoders can be set up */

	if (event->header.type == PERF_RECORD_AUX_OUTPUT_HW_ID) {

		(*(int *)data)++; /* increment found count */

		return cs_etm__process_aux_output_hw_id(session, event);

	}

	return 0;

}



static int cs_etm__queue_aux_records_cb(struct perf_session *session, union perf_event *event,

					u64 offset __maybe_unused, void *data __maybe_unused)

{
@@ -2839,13 +2992,13 @@ static int cs_etm__map_trace_ids_metadata(int num_cpu, u64 **metadata) 
		cs_etm_magic = metadata[i][CS_ETM_MAGIC];

		switch (cs_etm_magic) {

		case __perf_cs_etmv3_magic:

			trace_chan_id = (u8)((metadata[i][CS_ETM_ETMTRACEIDR]) &

					     CORESIGHT_TRACE_ID_VAL_MASK);

			metadata[i][CS_ETM_ETMTRACEIDR] &= CORESIGHT_TRACE_ID_VAL_MASK;

			trace_chan_id = (u8)(metadata[i][CS_ETM_ETMTRACEIDR]);

			break;

		case __perf_cs_etmv4_magic:

		case __perf_cs_ete_magic:

			trace_chan_id = (u8)((metadata[i][CS_ETMV4_TRCTRACEIDR]) &

					      CORESIGHT_TRACE_ID_VAL_MASK);

			metadata[i][CS_ETMV4_TRCTRACEIDR] &= CORESIGHT_TRACE_ID_VAL_MASK;

			trace_chan_id = (u8)(metadata[i][CS_ETMV4_TRCTRACEIDR]);

			break;

		default:

			/* unknown magic number */
@@ -2858,6 +3011,35 @@ static int cs_etm__map_trace_ids_metadata(int num_cpu, u64 **metadata) 
	return 0;

}



/*

 * If we found AUX_HW_ID packets, then set any metadata marked as unused to the

 * unused value to reduce the number of unneeded decoders created.

 */

static int cs_etm__clear_unused_trace_ids_metadata(int num_cpu, u64 **metadata)

{

	u64 cs_etm_magic;

	int i;



	for (i = 0; i < num_cpu; i++) {

		cs_etm_magic = metadata[i][CS_ETM_MAGIC];

		switch (cs_etm_magic) {

		case __perf_cs_etmv3_magic:

			if (metadata[i][CS_ETM_ETMTRACEIDR] & CORESIGHT_TRACE_ID_UNUSED_FLAG)

				metadata[i][CS_ETM_ETMTRACEIDR] = CORESIGHT_TRACE_ID_UNUSED_VAL;

			break;

		case __perf_cs_etmv4_magic:

		case __perf_cs_ete_magic:

			if (metadata[i][CS_ETMV4_TRCTRACEIDR] & CORESIGHT_TRACE_ID_UNUSED_FLAG)

				metadata[i][CS_ETMV4_TRCTRACEIDR] = CORESIGHT_TRACE_ID_UNUSED_VAL;

			break;

		default:

			/* unknown magic number */

			return -EINVAL;

		}

	}

	return 0;

}



int cs_etm__process_auxtrace_info_full(union perf_event *event,

				       struct perf_session *session)

{
@@ -2869,6 +3051,7 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event, 
	int priv_size = 0;

	int num_cpu;

	int err = 0;

	int aux_hw_id_found;

	int i, j;

	u64 *ptr = NULL;

	u64 **metadata = NULL;
@@ -3017,8 +3200,43 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event, 
	if (err)

		goto err_delete_thread;



	/* before aux records are queued, need to map metadata to trace IDs */

	/*

	 * Map Trace ID values to CPU metadata.

	 *

	 * Trace metadata will always contain Trace ID values from the legacy algorithm. If the

	 * files has been recorded by a "new" perf updated to handle AUX_HW_ID then the metadata

	 * ID value will also have the CORESIGHT_TRACE_ID_UNUSED_FLAG set.

	 *

	 * The updated kernel drivers that use AUX_HW_ID to sent Trace IDs will attempt to use

	 * the same IDs as the old algorithm as far as is possible, unless there are clashes

	 * in which case a different value will be used. This means an older perf may still

	 * be able to record and read files generate on a newer system.

	 *

	 * For a perf able to interpret AUX_HW_ID packets we first check for the presence of

	 * those packets. If they are there then the values will be mapped and plugged into

	 * the metadata. We then set any remaining metadata values with the used flag to a

	 * value CORESIGHT_TRACE_ID_UNUSED_VAL - which indicates no decoder is required.

	 *

	 * If no AUX_HW_ID packets are present - which means a file recorded on an old kernel

	 * then we map Trace ID values to CPU directly from the metadata - clearing any unused

	 * flags if present.

	 */



	/* first scan for AUX_OUTPUT_HW_ID records to map trace ID values to CPU metadata */

	aux_hw_id_found = 0;

	err = perf_session__peek_events(session, session->header.data_offset,

					session->header.data_size,

					cs_etm__process_aux_hw_id_cb, &aux_hw_id_found);

	if (err)

		goto err_delete_thread;



	/* if HW ID found then clear any unused metadata ID values */

	if (aux_hw_id_found)

		err = cs_etm__clear_unused_trace_ids_metadata(num_cpu, metadata);

	/* otherwise, this is a file with metadata values only, map from metadata */

	else

		err = cs_etm__map_trace_ids_metadata(num_cpu, metadata);



	if (err)

		goto err_delete_thread;
@@ -3027,14 +3245,6 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event, 
		goto err_delete_thread;



	etm->data_queued = etm->queues.populated;

	/*

	 * Print warning in pipe mode, see cs_etm__process_auxtrace_event() and

	 * cs_etm__queue_aux_fragment() for details relating to limitations.

	 */

	if (!etm->data_queued)

		pr_warning("CS ETM warning: Coresight decode and TRBE support requires random file access.\n"

			   "Continuing with best effort decoding in piped mode.\n\n");



	return 0;



err_delete_thread: