LinuxLists.cc - [PATCH v3 00/14] coresight: Use per-sink trace ID maps for Perf sessions

2024-06-11 15:02:51

Subject: [PATCH v3 00/14] coresight: Use per-sink trace ID maps for Perf sessions

2024-06-11 15:03:05

Subject: [PATCH v3 01/14] perf: cs-etm: Create decoders after both AUX and HW_ID search passes

Both of these passes gather information about how to create the
decoders. AUX records determine formatted/unformatted, and the HW_IDs
determine the traceID/metadata mappings. Therefore it makes sense to
cache the information and wait until both passes are over until creating
the decoders, rather than creating them at the first HW_ID found. This
will allow a simplification of the creation process where
cs_etm_queue->traceid_list will exclusively used to create the decoders,
rather than the current two methods depending on whether the trace is
formatted or not.

Previously the sample CPU from the AUX record was used to initialize
the decoder CPU, but actually sample CPU == AUX queue index in per-CPU
mode, so saving the sample CPU isn't required. Similarly
formatted/unformatted was used upfront to create the decoders, but now
it's cached until later.

Signed-off-by: James Clark <[email protected]>
---
tools/perf/util/cs-etm.c | 167 ++++++++++++++++++++++++---------------
1 file changed, 102 insertions(+), 65 deletions(-)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index 32818bd7cd17..f09004c4ba44 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -103,6 +103,7 @@ struct cs_etm_queue {
struct auxtrace_buffer *buffer;
unsigned int queue_nr;
u8 pending_timestamp_chan_id;
+ bool formatted;
u64 offset;
const unsigned char *buf;
size_t buf_len, buf_used;
@@ -738,8 +739,7 @@ static int cs_etm__init_trace_params(struct cs_etm_trace_params *t_params,

static int cs_etm__init_decoder_params(struct cs_etm_decoder_params *d_params,
struct cs_etm_queue *etmq,
- enum cs_etm_decoder_operation mode,
- bool formatted)
+ enum cs_etm_decoder_operation mode)
{
int ret = -EINVAL;

@@ -749,7 +749,7 @@ static int cs_etm__init_decoder_params(struct cs_etm_decoder_params *d_params,
d_params->packet_printer = cs_etm__packet_dump;
d_params->operation = mode;
d_params->data = etmq;
- d_params->formatted = formatted;
+ d_params->formatted = etmq->formatted;
d_params->fsyncs = false;
d_params->hsyncs = false;
d_params->frame_aligned = true;
@@ -1041,81 +1041,34 @@ static u32 cs_etm__mem_access(struct cs_etm_queue *etmq, u8 trace_chan_id,
return ret;
}

-static struct cs_etm_queue *cs_etm__alloc_queue(struct cs_etm_auxtrace *etm,
- bool formatted, int sample_cpu)
+static struct cs_etm_queue *cs_etm__alloc_queue(void)
{
- struct cs_etm_decoder_params d_params;
- struct cs_etm_trace_params *t_params = NULL;
- struct cs_etm_queue *etmq;
- /*
- * Each queue can only contain data from one CPU when unformatted, so only one decoder is
- * needed.
- */
- int decoders = formatted ? etm->num_cpu : 1;
-
- etmq = zalloc(sizeof(*etmq));
+ struct cs_etm_queue *etmq = zalloc(sizeof(*etmq));
if (!etmq)
return NULL;

etmq->traceid_queues_list = intlist__new(NULL);
if (!etmq->traceid_queues_list)
- goto out_free;
-
- /* Use metadata to fill in trace parameters for trace decoder */
- t_params = zalloc(sizeof(*t_params) * decoders);
+ free(etmq);

- if (!t_params)
- goto out_free;
-
- if (cs_etm__init_trace_params(t_params, etm, formatted, sample_cpu, decoders))
- goto out_free;
-
- /* Set decoder parameters to decode trace packets */
- if (cs_etm__init_decoder_params(&d_params, etmq,
- dump_trace ? CS_ETM_OPERATION_PRINT :
- CS_ETM_OPERATION_DECODE,
- formatted))
- goto out_free;
-
- etmq->decoder = cs_etm_decoder__new(decoders, &d_params,
- t_params);
-
- if (!etmq->decoder)
- goto out_free;
-
- /*
- * Register a function to handle all memory accesses required by
- * the trace decoder library.
- */
- if (cs_etm_decoder__add_mem_access_cb(etmq->decoder,
- 0x0L, ((u64) -1L),
- cs_etm__mem_access))
- goto out_free_decoder;
-
- zfree(&t_params);
return etmq;
-
-out_free_decoder:
- cs_etm_decoder__free(etmq->decoder);
-out_free:
- intlist__delete(etmq->traceid_queues_list);
- free(etmq);
-
- return NULL;
}

static int cs_etm__setup_queue(struct cs_etm_auxtrace *etm,
struct auxtrace_queue *queue,
- unsigned int queue_nr,
- bool formatted,
- int sample_cpu)
+ unsigned int queue_nr, bool formatted)
{
struct cs_etm_queue *etmq = queue->priv;

+ if (etmq && formatted != etmq->formatted) {
+ pr_err("CS_ETM: mixed formatted and unformatted trace not supported\n");
+ return -EINVAL;
+ }
+
if (list_empty(&queue->head) || etmq)
return 0;

- etmq = cs_etm__alloc_queue(etm, formatted, sample_cpu);
+ etmq = cs_etm__alloc_queue();

if (!etmq)
return -ENOMEM;
@@ -1123,7 +1076,9 @@ static int cs_etm__setup_queue(struct cs_etm_auxtrace *etm,
queue->priv = etmq;
etmq->etm = etm;
etmq->queue_nr = queue_nr;
+ queue->cpu = queue_nr; /* Placeholder, may be reset to -1 in per-thread mode */
etmq->offset = 0;
+ etmq->formatted = formatted;

return 0;
}
@@ -2843,7 +2798,7 @@ static int cs_etm__process_auxtrace_event(struct perf_session *session,
* formatted in piped mode (true).
*/
err = cs_etm__setup_queue(etm, &etm->queues.queue_array[idx],
- idx, true, -1);
+ idx, true);
if (err)
return err;

@@ -3048,8 +3003,8 @@ static int cs_etm__queue_aux_fragment(struct perf_session *session, off_t file_o

idx = auxtrace_event->idx;
formatted = !(aux_event->flags & PERF_AUX_FLAG_CORESIGHT_FORMAT_RAW);
- return cs_etm__setup_queue(etm, &etm->queues.queue_array[idx],
- idx, formatted, sample->cpu);
+
+ return cs_etm__setup_queue(etm, &etm->queues.queue_array[idx], idx, formatted);
}

/* Wasn't inside this buffer, but there were no parse errors. 1 == 'not found' */
@@ -3233,6 +3188,84 @@ static int cs_etm__clear_unused_trace_ids_metadata(int num_cpu, u64 **metadata)
return 0;
}

+/*
+ * Use the data gathered by the peeks for HW_ID (trace ID mappings) and AUX
+ * (formatted or not) packets to create the decoders.
+ */
+static int cs_etm__create_queue_decoders(struct cs_etm_queue *etmq)
+{
+ struct cs_etm_decoder_params d_params;
+
+ /*
+ * Each queue can only contain data from one CPU when unformatted, so only one decoder is
+ * needed.
+ */
+ int decoders = etmq->formatted ? etmq->etm->num_cpu : 1;
+
+ /* Use metadata to fill in trace parameters for trace decoder */
+ struct cs_etm_trace_params *t_params = zalloc(sizeof(*t_params) * decoders);
+
+ if (!t_params)
+ goto out_free;
+
+ if (cs_etm__init_trace_params(t_params, etmq->etm, etmq->formatted,
+ etmq->queue_nr, decoders))
+ goto out_free;
+
+ /* Set decoder parameters to decode trace packets */
+ if (cs_etm__init_decoder_params(&d_params, etmq,
+ dump_trace ? CS_ETM_OPERATION_PRINT :
+ CS_ETM_OPERATION_DECODE))
+ goto out_free;
+
+ etmq->decoder = cs_etm_decoder__new(decoders, &d_params,
+ t_params);
+
+ if (!etmq->decoder)
+ goto out_free;
+
+ /*
+ * Register a function to handle all memory accesses required by
+ * the trace decoder library.
+ */
+ if (cs_etm_decoder__add_mem_access_cb(etmq->decoder,
+ 0x0L, ((u64) -1L),
+ cs_etm__mem_access))
+ goto out_free_decoder;
+
+ zfree(&t_params);
+ return 0;
+
+out_free_decoder:
+ cs_etm_decoder__free(etmq->decoder);
+out_free:
+ zfree(&t_params);
+ return -EINVAL;
+}
+
+static int cs_etm__create_decoders(struct cs_etm_auxtrace *etm)
+{
+ struct auxtrace_queues *queues = &etm->queues;
+
+ for (unsigned int i = 0; i < queues->nr_queues; i++) {
+ bool empty = list_empty(&queues->queue_array[i].head);
+ struct cs_etm_queue *etmq = queues->queue_array[i].priv;
+ int ret;
+
+ /*
+ * Don't create decoders for empty queues, mainly because
+ * etmq->formatted is unknown for empty queues.
+ */
+ if (empty)
+ continue;
+
+ ret = cs_etm__create_queue_decoders(etmq);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
int cs_etm__process_auxtrace_info_full(union perf_event *event,
struct perf_session *session)
{
@@ -3396,6 +3429,10 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
if (err)
goto err_free_queues;

+ err = cs_etm__queue_aux_records(session);
+ if (err)
+ goto err_free_queues;
+
/*
* Map Trace ID values to CPU metadata.
*
@@ -3418,7 +3455,7 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
* flags if present.
*/

- /* first scan for AUX_OUTPUT_HW_ID records to map trace ID values to CPU metadata */
+ /* 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,
@@ -3436,7 +3473,7 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
if (err)
goto err_free_queues;

- err = cs_etm__queue_aux_records(session);
+ err = cs_etm__create_decoders(etm);
if (err)
goto err_free_queues;

--
2.34.1

2024-06-11 15:04:02

by James Clark

[permalink] [raw]

Subject: [PATCH v3 03/14] perf: cs-etm: Move traceid_list to each queue

The global list won't work for per-sink trace ID allocations, so put a
list in each queue where the IDs will be unique to that queue.

To keep the same behavior as before, for version 0 of the HW_ID packets,
copy all the HW_ID mappings into all queues.

This change doesn't effect the decoders, only trace ID lookups on the
Perf side. The decoders are still created with global mappings which
will be fixed in a later commit.

Signed-off-by: James Clark <[email protected]>
---
.../perf/util/cs-etm-decoder/cs-etm-decoder.c | 28 +--
tools/perf/util/cs-etm.c | 195 ++++++++++--------
tools/perf/util/cs-etm.h | 2 +-
3 files changed, 126 insertions(+), 99 deletions(-)

diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
index e917985bbbe6..0c9c48cedbf1 100644
--- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
+++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
@@ -388,7 +388,8 @@ cs_etm_decoder__reset_timestamp(struct cs_etm_packet_queue *packet_queue)
}

static ocsd_datapath_resp_t
-cs_etm_decoder__buffer_packet(struct cs_etm_packet_queue *packet_queue,
+cs_etm_decoder__buffer_packet(struct cs_etm_queue *etmq,
+ struct cs_etm_packet_queue *packet_queue,
const u8 trace_chan_id,
enum cs_etm_sample_type sample_type)
{
@@ -398,7 +399,7 @@ cs_etm_decoder__buffer_packet(struct cs_etm_packet_queue *packet_queue,
if (packet_queue->packet_count >= CS_ETM_PACKET_MAX_BUFFER - 1)
return OCSD_RESP_FATAL_SYS_ERR;

- if (cs_etm__get_cpu(trace_chan_id, &cpu) < 0)
+ if (cs_etm__get_cpu(etmq, trace_chan_id, &cpu) < 0)
return OCSD_RESP_FATAL_SYS_ERR;

et = packet_queue->tail;
@@ -436,7 +437,7 @@ cs_etm_decoder__buffer_range(struct cs_etm_queue *etmq,
int ret = 0;
struct cs_etm_packet *packet;

- ret = cs_etm_decoder__buffer_packet(packet_queue, trace_chan_id,
+ ret = cs_etm_decoder__buffer_packet(etmq, packet_queue, trace_chan_id,
CS_ETM_RANGE);
if (ret != OCSD_RESP_CONT && ret != OCSD_RESP_WAIT)
return ret;
@@ -496,7 +497,8 @@ cs_etm_decoder__buffer_range(struct cs_etm_queue *etmq,
}

static ocsd_datapath_resp_t
-cs_etm_decoder__buffer_discontinuity(struct cs_etm_packet_queue *queue,
+cs_etm_decoder__buffer_discontinuity(struct cs_etm_queue *etmq,
+ struct cs_etm_packet_queue *queue,
const uint8_t trace_chan_id)
{
/*
@@ -504,18 +506,19 @@ cs_etm_decoder__buffer_discontinuity(struct cs_etm_packet_queue *queue,
* reset time statistics.
*/
cs_etm_decoder__reset_timestamp(queue);
- return cs_etm_decoder__buffer_packet(queue, trace_chan_id,
+ return cs_etm_decoder__buffer_packet(etmq, queue, trace_chan_id,
CS_ETM_DISCONTINUITY);
}

static ocsd_datapath_resp_t
-cs_etm_decoder__buffer_exception(struct cs_etm_packet_queue *queue,
+cs_etm_decoder__buffer_exception(struct cs_etm_queue *etmq,
+ struct cs_etm_packet_queue *queue,
const ocsd_generic_trace_elem *elem,
const uint8_t trace_chan_id)
{ int ret = 0;
struct cs_etm_packet *packet;

- ret = cs_etm_decoder__buffer_packet(queue, trace_chan_id,
+ ret = cs_etm_decoder__buffer_packet(etmq, queue, trace_chan_id,
CS_ETM_EXCEPTION);
if (ret != OCSD_RESP_CONT && ret != OCSD_RESP_WAIT)
return ret;
@@ -527,10 +530,11 @@ cs_etm_decoder__buffer_exception(struct cs_etm_packet_queue *queue,
}

static ocsd_datapath_resp_t
-cs_etm_decoder__buffer_exception_ret(struct cs_etm_packet_queue *queue,
+cs_etm_decoder__buffer_exception_ret(struct cs_etm_queue *etmq,
+ struct cs_etm_packet_queue *queue,
const uint8_t trace_chan_id)
{
- return cs_etm_decoder__buffer_packet(queue, trace_chan_id,
+ return cs_etm_decoder__buffer_packet(etmq, queue, trace_chan_id,
CS_ETM_EXCEPTION_RET);
}

@@ -599,7 +603,7 @@ static ocsd_datapath_resp_t cs_etm_decoder__gen_trace_elem_printer(
case OCSD_GEN_TRC_ELEM_EO_TRACE:
case OCSD_GEN_TRC_ELEM_NO_SYNC:
case OCSD_GEN_TRC_ELEM_TRACE_ON:
- resp = cs_etm_decoder__buffer_discontinuity(packet_queue,
+ resp = cs_etm_decoder__buffer_discontinuity(etmq, packet_queue,
trace_chan_id);
break;
case OCSD_GEN_TRC_ELEM_INSTR_RANGE:
@@ -607,11 +611,11 @@ static ocsd_datapath_resp_t cs_etm_decoder__gen_trace_elem_printer(
trace_chan_id);
break;
case OCSD_GEN_TRC_ELEM_EXCEPTION:
- resp = cs_etm_decoder__buffer_exception(packet_queue, elem,
+ resp = cs_etm_decoder__buffer_exception(etmq, packet_queue, elem,
trace_chan_id);
break;
case OCSD_GEN_TRC_ELEM_EXCEPTION_RET:
- resp = cs_etm_decoder__buffer_exception_ret(packet_queue,
+ resp = cs_etm_decoder__buffer_exception_ret(etmq, packet_queue,
trace_chan_id);
break;
case OCSD_GEN_TRC_ELEM_TIMESTAMP:
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index e40dfd09d3ed..be858aed26c4 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -111,16 +111,18 @@ struct cs_etm_queue {
/* Conversion between traceID and index in traceid_queues array */
struct intlist *traceid_queues_list;
struct cs_etm_traceid_queue **traceid_queues;
+ /* Conversion between traceID and metadata pointers */
+ struct intlist *traceid_list;
};

-/* RB tree for quick conversion between traceID and metadata pointers */
-static struct intlist *traceid_list;
-
static int cs_etm__process_timestamped_queues(struct cs_etm_auxtrace *etm);
static int cs_etm__process_timeless_queues(struct cs_etm_auxtrace *etm,
pid_t tid);
static int cs_etm__get_data_block(struct cs_etm_queue *etmq);
static int cs_etm__decode_data_block(struct cs_etm_queue *etmq);
+static int cs_etm__metadata_get_trace_id(u8 *trace_chan_id, u64 *cpu_metadata);
+static u64 *get_cpu_data(struct cs_etm_auxtrace *etm, int cpu);
+static int cs_etm__metadata_set_trace_id(u8 trace_chan_id, u64 *cpu_metadata);

/* PTMs ETMIDR [11:8] set to b0011 */
#define ETMIDR_PTM_VERSION 0x00000300
@@ -146,12 +148,12 @@ static u32 cs_etm__get_v7_protocol_version(u32 etmidr)
return CS_ETM_PROTO_ETMV3;
}

-static int cs_etm__get_magic(u8 trace_chan_id, u64 *magic)
+static int cs_etm__get_magic(struct cs_etm_queue *etmq, u8 trace_chan_id, u64 *magic)
{
struct int_node *inode;
u64 *metadata;

- inode = intlist__find(traceid_list, trace_chan_id);
+ inode = intlist__find(etmq->traceid_list, trace_chan_id);
if (!inode)
return -EINVAL;

@@ -160,12 +162,12 @@ static int cs_etm__get_magic(u8 trace_chan_id, u64 *magic)
return 0;
}

-int cs_etm__get_cpu(u8 trace_chan_id, int *cpu)
+int cs_etm__get_cpu(struct cs_etm_queue *etmq, u8 trace_chan_id, int *cpu)
{
struct int_node *inode;
u64 *metadata;

- inode = intlist__find(traceid_list, trace_chan_id);
+ inode = intlist__find(etmq->traceid_list, trace_chan_id);
if (!inode)
return -EINVAL;

@@ -217,30 +219,86 @@ enum cs_etm_pid_fmt cs_etm__get_pid_fmt(struct cs_etm_queue *etmq)
return etmq->etm->pid_fmt;
}

-static int cs_etm__map_trace_id(u8 trace_chan_id, u64 *cpu_metadata)
+static int cs_etm__insert_trace_id_node(struct cs_etm_queue *etmq,
+ u8 trace_chan_id, u64 *cpu_metadata)
{
- struct int_node *inode;
-
/* Get an RB node for this CPU */
- inode = intlist__findnew(traceid_list, trace_chan_id);
+ struct int_node *inode = intlist__findnew(etmq->traceid_list, trace_chan_id);

/* Something went wrong, no need to continue */
if (!inode)
return -ENOMEM;

- /*
- * The node for that CPU should not be taken.
- * Back out if that's the case.
- */
- if (inode->priv)
- return -EINVAL;
+ /* Disallow re-mapping a different traceID to metadata pair. */
+ if (inode->priv) {
+ u64 *curr_cpu_data = inode->priv;
+ u8 curr_chan_id;
+ int err;
+
+ if (curr_cpu_data[CS_ETM_CPU] != cpu_metadata[CS_ETM_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, curr_cpu_data);
+ if (err)
+ return err;

- /* All good, associate the traceID with the metadata pointer */
+ if (curr_chan_id != trace_chan_id) {
+ pr_err("CS_ETM: mismatch between CPU trace ID and HW_ID packet ID\n");
+ return -EINVAL;
+ }
+
+ /* Skip re-adding the same mappings if everything matched */
+ return 0;
+ }
+
+ /* Not one we've seen before, associate the traceID with the metadata pointer */
inode->priv = cpu_metadata;

return 0;
}

+static int cs_etm__map_trace_id_v0(struct cs_etm_auxtrace *etm, u8 trace_chan_id,
+ u64 *cpu_metadata)
+{
+ /* Version 0 trace IDs are global so save them into every queue */
+ for (unsigned int i = 0; i < etm->queues.nr_queues; ++i) {
+ int ret;
+ struct cs_etm_queue *etmq = etm->queues.queue_array[i].priv;
+
+ ret = cs_etm__insert_trace_id_node(etmq, trace_chan_id,
+ cpu_metadata);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int cs_etm__process_trace_id_v0(struct cs_etm_auxtrace *etm, int cpu,
+ u64 hw_id)
+{
+ int err;
+ u64 *cpu_data;
+ u8 trace_chan_id = FIELD_GET(CS_AUX_HW_ID_TRACE_ID_MASK, hw_id);
+
+ cpu_data = get_cpu_data(etm, cpu);
+ if (cpu_data == NULL)
+ return -EINVAL;
+
+ err = cs_etm__map_trace_id_v0(etm, 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.
+ */
+ return cs_etm__metadata_set_trace_id(trace_chan_id, cpu_data);
+}
+
static int cs_etm__metadata_get_trace_id(u8 *trace_chan_id, u64 *cpu_metadata)
{
u64 cs_etm_magic = cpu_metadata[CS_ETM_MAGIC];
@@ -324,17 +382,13 @@ static int cs_etm__process_aux_output_hw_id(struct perf_session *session,
{
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) {
@@ -362,43 +416,7 @@ static int cs_etm__process_aux_output_hw_id(struct perf_session *session,
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;
- }
-
- cpu_data = get_cpu_data(etm, cpu);
- if (cpu_data == NULL)
- return err;
-
- /* not one we've seen before - lets map it */
- 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;
+ return cs_etm__process_trace_id_v0(etm, cpu, hw_id);
}

void cs_etm__etmq_set_traceid_queue_timestamp(struct cs_etm_queue *etmq,
@@ -851,6 +869,7 @@ static void cs_etm__free_traceid_queues(struct cs_etm_queue *etmq)

static void cs_etm__free_queue(void *priv)
{
+ struct int_node *inode, *tmp;
struct cs_etm_queue *etmq = priv;

if (!etmq)
@@ -858,6 +877,14 @@ static void cs_etm__free_queue(void *priv)

cs_etm_decoder__free(etmq->decoder);
cs_etm__free_traceid_queues(etmq);
+
+ /* First remove all traceID/metadata nodes for the RB tree */
+ intlist__for_each_entry_safe(inode, tmp, etmq->traceid_list)
+ intlist__remove(etmq->traceid_list, inode);
+
+ /* Then the RB tree itself */
+ intlist__delete(etmq->traceid_list);
+
free(etmq);
}

@@ -880,19 +907,12 @@ static void cs_etm__free_events(struct perf_session *session)
static void cs_etm__free(struct perf_session *session)
{
int i;
- struct int_node *inode, *tmp;
struct cs_etm_auxtrace *aux = container_of(session->auxtrace,
struct cs_etm_auxtrace,
auxtrace);
cs_etm__free_events(session);
session->auxtrace = NULL;

- /* First remove all traceID/metadata nodes for the RB tree */
- intlist__for_each_entry_safe(inode, tmp, traceid_list)
- intlist__remove(traceid_list, inode);
- /* Then the RB tree itself */
- intlist__delete(traceid_list);
-
for (i = 0; i < aux->num_cpu; i++)
zfree(&aux->metadata[i]);

@@ -1050,9 +1070,24 @@ static struct cs_etm_queue *cs_etm__alloc_queue(void)

etmq->traceid_queues_list = intlist__new(NULL);
if (!etmq->traceid_queues_list)
- free(etmq);
+ goto out_free;
+
+ /*
+ * Create an RB tree for traceID-metadata tuple. Since the conversion
+ * has to be made for each packet that gets decoded, optimizing access
+ * in anything other than a sequential array is worth doing.
+ */
+ etmq->traceid_list = intlist__new(NULL);
+ if (!etmq->traceid_list)
+ goto out_free;

return etmq;
+
+out_free:
+ intlist__delete(etmq->traceid_queues_list);
+ free(etmq);
+
+ return NULL;
}

static int cs_etm__setup_queue(struct cs_etm_auxtrace *etm,
@@ -2202,7 +2237,7 @@ static int cs_etm__set_sample_flags(struct cs_etm_queue *etmq,
PERF_IP_FLAG_TRACE_END;
break;
case CS_ETM_EXCEPTION:
- ret = cs_etm__get_magic(packet->trace_chan_id, &magic);
+ ret = cs_etm__get_magic(etmq, packet->trace_chan_id, &magic);
if (ret)
return ret;

@@ -3119,7 +3154,8 @@ static bool cs_etm__has_virtual_ts(u64 **metadata, int num_cpu)
}

/* map trace ids to correct metadata block, from information in metadata */
-static int cs_etm__map_trace_ids_metadata(int num_cpu, u64 **metadata)
+static int cs_etm__map_trace_ids_metadata(struct cs_etm_auxtrace *etm, int num_cpu,
+ u64 **metadata)
{
u64 cs_etm_magic;
u8 trace_chan_id;
@@ -3141,7 +3177,7 @@ static int cs_etm__map_trace_ids_metadata(int num_cpu, u64 **metadata)
/* unknown magic number */
return -EINVAL;
}
- err = cs_etm__map_trace_id(trace_chan_id, metadata[i]);
+ err = cs_etm__map_trace_id_v0(etm, trace_chan_id, metadata[i]);
if (err)
return err;
}
@@ -3272,23 +3308,12 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
u64 *ptr = NULL;
u64 **metadata = NULL;

- /*
- * Create an RB tree for traceID-metadata tuple. Since the conversion
- * has to be made for each packet that gets decoded, optimizing access
- * in anything other than a sequential array is worth doing.
- */
- traceid_list = intlist__new(NULL);
- if (!traceid_list)
- return -ENOMEM;
-
/* First the global part */
ptr = (u64 *) auxtrace_info->priv;
num_cpu = ptr[CS_PMU_TYPE_CPUS] & 0xffffffff;
metadata = zalloc(sizeof(*metadata) * num_cpu);
- if (!metadata) {
- err = -ENOMEM;
- goto err_free_traceid_list;
- }
+ if (!metadata)
+ return -ENOMEM;

/* Start parsing after the common part of the header */
i = CS_HEADER_VERSION_MAX;
@@ -3467,7 +3492,7 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
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);
+ err = cs_etm__map_trace_ids_metadata(etm, num_cpu, metadata);

if (err)
goto err_free_queues;
@@ -3489,7 +3514,5 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
for (int j = 0; j < num_cpu; j++)
zfree(&metadata[j]);
zfree(&metadata);
-err_free_traceid_list:
- intlist__delete(traceid_list);
return err;
}
diff --git a/tools/perf/util/cs-etm.h b/tools/perf/util/cs-etm.h
index 4696267a32f0..f4f69f7cc0f3 100644
--- a/tools/perf/util/cs-etm.h
+++ b/tools/perf/util/cs-etm.h
@@ -252,7 +252,7 @@ enum cs_etm_pid_fmt {

#ifdef HAVE_CSTRACE_SUPPORT
#include <opencsd/ocsd_if_types.h>
-int cs_etm__get_cpu(u8 trace_chan_id, int *cpu);
+int cs_etm__get_cpu(struct cs_etm_queue *etmq, u8 trace_chan_id, int *cpu);
enum cs_etm_pid_fmt cs_etm__get_pid_fmt(struct cs_etm_queue *etmq);
int cs_etm__etmq_set_tid_el(struct cs_etm_queue *etmq, pid_t tid,
u8 trace_chan_id, ocsd_ex_level el);
--
2.34.1

2024-06-11 15:04:50

by James Clark

[permalink] [raw]

Subject: [PATCH v3 02/14] perf: cs-etm: Allocate queues for all CPUs

Make cs_etm__setup_queue() setup a queue even if it's empty, and
pre-allocate queues based on the max CPU that was recorded. In per-CPU
mode aux queues are indexed based on CPU ID even if all CPUs aren't
recorded, sparse queue arrays aren't used.

This will allow HW_IDs to be saved even if no aux data was received in
that queue without having to call cs_etm__setup_queue() from two
different places.

Signed-off-by: James Clark <[email protected]>
---
tools/perf/util/cs-etm.c | 55 ++++++++++++++++++++--------------------
1 file changed, 27 insertions(+), 28 deletions(-)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index f09004c4ba44..e40dfd09d3ed 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -104,6 +104,7 @@ struct cs_etm_queue {
unsigned int queue_nr;
u8 pending_timestamp_chan_id;
bool formatted;
+ bool formatted_set;
u64 offset;
const unsigned char *buf;
size_t buf_len, buf_used;
@@ -1056,16 +1057,11 @@ static struct cs_etm_queue *cs_etm__alloc_queue(void)

static int cs_etm__setup_queue(struct cs_etm_auxtrace *etm,
struct auxtrace_queue *queue,
- unsigned int queue_nr, bool formatted)
+ unsigned int queue_nr)
{
struct cs_etm_queue *etmq = queue->priv;

- if (etmq && formatted != etmq->formatted) {
- pr_err("CS_ETM: mixed formatted and unformatted trace not supported\n");
- return -EINVAL;
- }
-
- if (list_empty(&queue->head) || etmq)
+ if (etmq)
return 0;

etmq = cs_etm__alloc_queue();
@@ -1078,7 +1074,6 @@ static int cs_etm__setup_queue(struct cs_etm_auxtrace *etm,
etmq->queue_nr = queue_nr;
queue->cpu = queue_nr; /* Placeholder, may be reset to -1 in per-thread mode */
etmq->offset = 0;
- etmq->formatted = formatted;

return 0;
}
@@ -2791,17 +2786,6 @@ static int cs_etm__process_auxtrace_event(struct perf_session *session,
if (err)
return err;

- /*
- * Knowing if the trace is formatted or not requires a lookup of
- * the aux record so only works in non-piped mode where data is
- * queued in cs_etm__queue_aux_records(). Always assume
- * formatted in piped mode (true).
- */
- err = cs_etm__setup_queue(etm, &etm->queues.queue_array[idx],
- idx, true);
- if (err)
- return err;
-
if (dump_trace)
if (auxtrace_buffer__get_data(buffer, fd)) {
cs_etm__dump_event(etm->queues.queue_array[idx].priv, buffer);
@@ -2918,7 +2902,6 @@ static int cs_etm__queue_aux_fragment(struct perf_session *session, off_t file_o
struct perf_record_auxtrace *auxtrace_event;
union perf_event auxtrace_fragment;
__u64 aux_offset, aux_size;
- __u32 idx;
bool formatted;

struct cs_etm_auxtrace *etm = container_of(session->auxtrace,
@@ -2985,6 +2968,8 @@ static int cs_etm__queue_aux_fragment(struct perf_session *session, off_t file_o

if (aux_offset >= auxtrace_event->offset &&
aux_offset + aux_size <= auxtrace_event->offset + auxtrace_event->size) {
+ struct cs_etm_queue *etmq = etm->queues.queue_array[auxtrace_event->idx].priv;
+
/*
* If this AUX event was inside this buffer somewhere, create a new auxtrace event
* based on the sizes of the aux event, and queue that fragment.
@@ -3001,10 +2986,14 @@ static int cs_etm__queue_aux_fragment(struct perf_session *session, off_t file_o
if (err)
return err;

- idx = auxtrace_event->idx;
formatted = !(aux_event->flags & PERF_AUX_FLAG_CORESIGHT_FORMAT_RAW);
-
- return cs_etm__setup_queue(etm, &etm->queues.queue_array[idx], idx, formatted);
+ if (etmq->formatted_set && formatted != etmq->formatted) {
+ pr_err("CS_ETM: mixed formatted and unformatted trace not supported\n");
+ return -EINVAL;
+ }
+ etmq->formatted = formatted;
+ etmq->formatted_set = true;
+ return 0;
}

/* Wasn't inside this buffer, but there were no parse errors. 1 == 'not found' */
@@ -3256,6 +3245,7 @@ static int cs_etm__create_decoders(struct cs_etm_auxtrace *etm)
* Don't create decoders for empty queues, mainly because
* etmq->formatted is unknown for empty queues.
*/
+ assert(empty == !etmq->formatted_set);
if (empty)
continue;

@@ -3275,10 +3265,10 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
int event_header_size = sizeof(struct perf_event_header);
int total_size = auxtrace_info->header.size;
int priv_size = 0;
- int num_cpu;
+ int num_cpu, max_cpu = 0;
int err = 0;
int aux_hw_id_found;
- int i, j;
+ int i;
u64 *ptr = NULL;
u64 **metadata = NULL;

@@ -3309,7 +3299,7 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
* required by the trace decoder to properly decode the trace due
* to its highly compressed nature.
*/
- for (j = 0; j < num_cpu; j++) {
+ for (int j = 0; j < num_cpu; j++) {
if (ptr[i] == __perf_cs_etmv3_magic) {
metadata[j] =
cs_etm__create_meta_blk(ptr, &i,
@@ -3333,6 +3323,9 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
err = -ENOMEM;
goto err_free_metadata;
}
+
+ if ((int) metadata[j][CS_ETM_CPU] > max_cpu)
+ max_cpu = metadata[j][CS_ETM_CPU];
}

/*
@@ -3362,10 +3355,16 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
*/
etm->pid_fmt = cs_etm__init_pid_fmt(metadata[0]);

- err = auxtrace_queues__init(&etm->queues);
+ err = auxtrace_queues__init_nr(&etm->queues, max_cpu + 1);
if (err)
goto err_free_etm;

+ for (unsigned int j = 0; j < etm->queues.nr_queues; ++j) {
+ err = cs_etm__setup_queue(etm, &etm->queues.queue_array[j], j);
+ if (err)
+ goto err_free_queues;
+ }
+
if (session->itrace_synth_opts->set) {
etm->synth_opts = *session->itrace_synth_opts;
} else {
@@ -3487,7 +3486,7 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
zfree(&etm);
err_free_metadata:
/* No need to check @metadata[j], free(NULL) is supported */
- for (j = 0; j < num_cpu; j++)
+ for (int j = 0; j < num_cpu; j++)
zfree(&metadata[j]);
zfree(&metadata);
err_free_traceid_list:
--
2.34.1

2024-06-11 15:05:01

by James Clark

[permalink] [raw]

Subject: [PATCH v3 05/14] perf: cs-etm: Support version 0.1 of HW_ID packets

v0.1 HW_ID packets have a new field that describes which sink each CPU
writes to. Use the sink ID to link trace ID maps to each other so that
mappings are shared wherever the sink is shared.

Also update the error message to show that overlapping IDs aren't an
error in per-thread mode, just not supported. In the future we can
use the CPU ID from the AUX records, or watch for changing sink IDs on
HW_ID packets to use the correct decoders.

Signed-off-by: James Clark <[email protected]>
---
tools/include/linux/coresight-pmu.h | 17 ++++-
tools/perf/util/cs-etm.c | 110 +++++++++++++++++++++++++---
2 files changed, 113 insertions(+), 14 deletions(-)

diff --git a/tools/include/linux/coresight-pmu.h b/tools/include/linux/coresight-pmu.h
index 51ac441a37c3..89b0ac0014b0 100644
--- a/tools/include/linux/coresight-pmu.h
+++ b/tools/include/linux/coresight-pmu.h
@@ -49,12 +49,21 @@
* 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
+ * [39:08] - Sink ID - as reported in /sys/bus/event_source/devices/cs_etm/sinks/
+ * Added in minor version 1.
+ * [55:40] - Unused (SBZ)
+ * [59:56] - Minor Version - previously existing fields are compatible with
+ * all minor versions.
+ * [63:60] - Major Version - previously existing fields mean different things
+ * in new major versions.
*/
#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_SINK_ID_MASK GENMASK_ULL(39, 8)

-#define CS_AUX_HW_ID_CURR_VERSION 0
+#define CS_AUX_HW_ID_MINOR_VERSION_MASK GENMASK_ULL(59, 56)
+#define CS_AUX_HW_ID_MAJOR_VERSION_MASK GENMASK_ULL(63, 60)
+
+#define CS_AUX_HW_ID_MAJOR_VERSION 0
+#define CS_AUX_HW_ID_MINOR_VERSION 1

#endif
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index 73fc0ab2fb09..b0f9a3933b03 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -113,6 +113,12 @@ struct cs_etm_queue {
struct cs_etm_traceid_queue **traceid_queues;
/* Conversion between traceID and metadata pointers */
struct intlist *traceid_list;
+ /*
+ * Same as traceid_list, but traceid_list may be a reference to another
+ * queue's which has a matching sink ID.
+ */
+ struct intlist *own_traceid_list;
+ u32 sink_id;
};

static int cs_etm__process_timestamped_queues(struct cs_etm_auxtrace *etm);
@@ -137,6 +143,7 @@ static int cs_etm__metadata_set_trace_id(u8 trace_chan_id, u64 *cpu_metadata);
(queue_nr << 16 | trace_chan_id)
#define TO_QUEUE_NR(cs_queue_nr) (cs_queue_nr >> 16)
#define TO_TRACE_CHAN_ID(cs_queue_nr) (cs_queue_nr & 0x0000ffff)
+#define SINK_UNSET ((u32) -1)

static u32 cs_etm__get_v7_protocol_version(u32 etmidr)
{
@@ -236,7 +243,16 @@ static int cs_etm__insert_trace_id_node(struct cs_etm_queue *etmq,
int err;

if (curr_cpu_data[CS_ETM_CPU] != cpu_metadata[CS_ETM_CPU]) {
- pr_err("CS_ETM: map mismatch between HW_ID packet CPU and Trace ID\n");
+ /*
+ * With > CORESIGHT_TRACE_IDS_MAX ETMs, overlapping IDs
+ * are expected (but not supported) in per-thread mode,
+ * rather than signifying an error.
+ */
+ if (etmq->etm->per_thread_decoding)
+ pr_err("CS_ETM: overlapping Trace IDs aren't currently supported in per-thread mode\n");
+ else
+ pr_err("CS_ETM: map mismatch between HW_ID packet CPU and Trace ID\n");
+
return -EINVAL;
}

@@ -303,6 +319,74 @@ static int cs_etm__process_trace_id_v0(struct cs_etm_auxtrace *etm, int cpu,
return cs_etm__metadata_set_trace_id(trace_chan_id, cpu_data);
}

+static int cs_etm__process_trace_id_v0_1(struct cs_etm_auxtrace *etm, int cpu,
+ u64 hw_id)
+{
+ struct cs_etm_queue *etmq;
+ int ret;
+ u64 *cpu_data;
+ u32 sink_id = FIELD_GET(CS_AUX_HW_ID_SINK_ID_MASK, hw_id);
+ u8 trace_id = FIELD_GET(CS_AUX_HW_ID_TRACE_ID_MASK, hw_id);
+
+ /* In per thread mode there is only one queue and it's index 0 */
+ if (etm->per_thread_decoding)
+ etmq = etm->queues.queue_array[0].priv;
+ else
+ etmq = etm->queues.queue_array[cpu].priv;
+
+ /* Ignore HW_IDs on unformatted queues */
+ if (etmq->formatted_set && !etmq->formatted)
+ return 0;
+
+ /*
+ * Check sink id hasn't changed in per-cpu mode. In per-thread mode,
+ * let it pass for now until an actual overlapping trace ID is hit. In
+ * most cases IDs won't overlap even if the sink changes.
+ */
+ if (!etmq->etm->per_thread_decoding && etmq->sink_id != SINK_UNSET &&
+ etmq->sink_id != sink_id) {
+ pr_err("CS_ETM: mismatch between sink IDs\n");
+ return -EINVAL;
+ }
+
+ etmq->sink_id = sink_id;
+
+ /* Find which other queues use this sink and link their ID maps */
+ for (unsigned int i = 0; i < etm->queues.nr_queues; ++i) {
+ struct cs_etm_queue *other_etmq = etm->queues.queue_array[i].priv;
+
+ /* Different sinks, skip */
+ if (other_etmq->sink_id != etmq->sink_id)
+ continue;
+
+ /* Already linked, skip */
+ if (other_etmq->traceid_list == etmq->traceid_list)
+ continue;
+
+ /* At the point of first linking, this one should be empty */
+ if (!intlist__empty(etmq->traceid_list)) {
+ pr_err("CS_ETM: Can't link populated trace ID lists\n");
+ return -EINVAL;
+ }
+
+ etmq->own_traceid_list = NULL;
+ intlist__delete(etmq->traceid_list);
+ etmq->traceid_list = other_etmq->traceid_list;
+ break;
+ }
+
+ cpu_data = get_cpu_data(etm, cpu);
+ ret = cs_etm__insert_trace_id_node(etmq, trace_id, cpu_data);
+ if (ret)
+ return ret;
+
+ ret = cs_etm__metadata_set_trace_id(trace_id, cpu_data);
+ if (ret)
+ return ret;
+
+ 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];
@@ -392,10 +476,10 @@ static int cs_etm__process_aux_output_hw_id(struct perf_session *session,

/* 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);
+ version = FIELD_GET(CS_AUX_HW_ID_MAJOR_VERSION_MASK, hw_id);

/* check that we can handle this version */
- if (version > CS_AUX_HW_ID_CURR_VERSION) {
+ if (version > CS_AUX_HW_ID_MAJOR_VERSION) {
pr_err("CS ETM Trace: PERF_RECORD_AUX_OUTPUT_HW_ID version %d not supported. Please update Perf.\n",
version);
return -EINVAL;
@@ -420,7 +504,10 @@ static int cs_etm__process_aux_output_hw_id(struct perf_session *session,
return -EINVAL;
}

- return cs_etm__process_trace_id_v0(etm, cpu, hw_id);
+ if (FIELD_GET(CS_AUX_HW_ID_MINOR_VERSION_MASK, hw_id) == 0)
+ return cs_etm__process_trace_id_v0(etm, cpu, hw_id);
+ else
+ return cs_etm__process_trace_id_v0_1(etm, cpu, hw_id);
}

void cs_etm__etmq_set_traceid_queue_timestamp(struct cs_etm_queue *etmq,
@@ -860,12 +947,14 @@ static void cs_etm__free_queue(void *priv)
cs_etm_decoder__free(etmq->decoder);
cs_etm__free_traceid_queues(etmq);

- /* First remove all traceID/metadata nodes for the RB tree */
- intlist__for_each_entry_safe(inode, tmp, etmq->traceid_list)
- intlist__remove(etmq->traceid_list, inode);
+ if (etmq->own_traceid_list) {
+ /* First remove all traceID/metadata nodes for the RB tree */
+ intlist__for_each_entry_safe(inode, tmp, etmq->own_traceid_list)
+ intlist__remove(etmq->own_traceid_list, inode);

- /* Then the RB tree itself */
- intlist__delete(etmq->traceid_list);
+ /* Then the RB tree itself */
+ intlist__delete(etmq->own_traceid_list);
+ }

free(etmq);
}
@@ -1059,7 +1148,7 @@ static struct cs_etm_queue *cs_etm__alloc_queue(void)
* has to be made for each packet that gets decoded, optimizing access
* in anything other than a sequential array is worth doing.
*/
- etmq->traceid_list = intlist__new(NULL);
+ etmq->traceid_list = etmq->own_traceid_list = intlist__new(NULL);
if (!etmq->traceid_list)
goto out_free;

@@ -1091,6 +1180,7 @@ static int cs_etm__setup_queue(struct cs_etm_auxtrace *etm,
etmq->queue_nr = queue_nr;
queue->cpu = queue_nr; /* Placeholder, may be reset to -1 in per-thread mode */
etmq->offset = 0;
+ etmq->sink_id = SINK_UNSET;

return 0;
}
--
2.34.1

2024-06-11 15:05:12

by James Clark

[permalink] [raw]

Subject: [PATCH v3 07/14] coresight: Clarify comments around the PID of the sink owner

"Process being monitored" and "pid of the process to monitor" imply that
this would be the same PID if there were two sessions targeting the same
process. But this is actually the PID of the process that did the Perf
event open call, rather than the target of the session. So update the
comments to make this clearer.

Reviewed-by: Anshuman Khandual <[email protected]>
Reviewed-by: Mike Leach <[email protected]>
Signed-off-by: James Clark <[email protected]>
---
drivers/hwtracing/coresight/coresight-tmc-etr.c | 5 +++--
drivers/hwtracing/coresight/coresight-tmc.h | 5 +++--
2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index e75428fa1592..8962fc27d04f 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -36,7 +36,8 @@ struct etr_buf_hw {
* etr_perf_buffer - Perf buffer used for ETR
* @drvdata - The ETR drvdaga this buffer has been allocated for.
* @etr_buf - Actual buffer used by the ETR
- * @pid - The PID this etr_perf_buffer belongs to.
+ * @pid - The PID of the session owner that etr_perf_buffer
+ * belongs to.
* @snaphost - Perf session mode
* @nr_pages - Number of pages in the ring buffer.
* @pages - Array of Pages in the ring buffer.
@@ -1662,7 +1663,7 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data)
goto unlock_out;
}

- /* Get a handle on the pid of the process to monitor */
+ /* Get a handle on the pid of the session owner */
pid = etr_perf->pid;

/* Do not proceed if this device is associated with another session */
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index c77763b49de0..2671926be62a 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -171,8 +171,9 @@ struct etr_buf {
* @csdev: component vitals needed by the framework.
* @miscdev: specifics to handle "/dev/xyz.tmc" entry.
* @spinlock: only one at a time pls.
- * @pid: Process ID of the process being monitored by the session
- * that is using this component.
+ * @pid: Process ID of the process that owns the session that is using
+ * this component. For example this would be the pid of the Perf
+ * process.
* @buf: Snapshot of the trace data for ETF/ETB.
* @etr_buf: details of buffer used in TMC-ETR
* @len: size of the available trace for ETF/ETB.
--
2.34.1

2024-06-11 15:05:18

by James Clark

[permalink] [raw]

Subject: [PATCH v3 06/14] coresight: Remove unused ETM Perf stubs

This file is never included anywhere if CONFIG_CORESIGHT is not set so
they are unused and aren't currently compile tested with any config so
remove them.

Reviewed-by: Anshuman Khandual <[email protected]>
Reviewed-by: Mike Leach <[email protected]>
Signed-off-by: James Clark <[email protected]>
---
.../hwtracing/coresight/coresight-etm-perf.h | 18 ------------------
1 file changed, 18 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.h b/drivers/hwtracing/coresight/coresight-etm-perf.h
index bebbadee2ceb..744531158d6b 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.h
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.h
@@ -62,7 +62,6 @@ struct etm_event_data {
struct list_head * __percpu *path;
};

-#if IS_ENABLED(CONFIG_CORESIGHT)
int etm_perf_symlink(struct coresight_device *csdev, bool link);
int etm_perf_add_symlink_sink(struct coresight_device *csdev);
void etm_perf_del_symlink_sink(struct coresight_device *csdev);
@@ -77,23 +76,6 @@ static inline void *etm_perf_sink_config(struct perf_output_handle *handle)
int etm_perf_add_symlink_cscfg(struct device *dev,
struct cscfg_config_desc *config_desc);
void etm_perf_del_symlink_cscfg(struct cscfg_config_desc *config_desc);
-#else
-static inline int etm_perf_symlink(struct coresight_device *csdev, bool link)
-{ return -EINVAL; }
-int etm_perf_add_symlink_sink(struct coresight_device *csdev)
-{ return -EINVAL; }
-void etm_perf_del_symlink_sink(struct coresight_device *csdev) {}
-static inline void *etm_perf_sink_config(struct perf_output_handle *handle)
-{
- return NULL;
-}
-int etm_perf_add_symlink_cscfg(struct device *dev,
- struct cscfg_config_desc *config_desc)
-{ return -EINVAL; }
-void etm_perf_del_symlink_cscfg(struct cscfg_config_desc *config_desc) {}
-
-#endif /* CONFIG_CORESIGHT */
-
int __init etm_perf_init(void);
void etm_perf_exit(void);

--
2.34.1

2024-06-11 15:05:25

by James Clark

[permalink] [raw]

Subject: [PATCH v3 08/14] coresight: Move struct coresight_trace_id_map to common header

The trace ID maps will need to be created and stored by the core and
Perf code so move the definition up to the common header.

Reviewed-by: Anshuman Khandual <[email protected]>
Reviewed-by: Mike Leach <[email protected]>
Signed-off-by: James Clark <[email protected]>
---
.../hwtracing/coresight/coresight-trace-id.c | 1 +
.../hwtracing/coresight/coresight-trace-id.h | 19 -------------------
include/linux/coresight.h | 18 ++++++++++++++++++
3 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-trace-id.c b/drivers/hwtracing/coresight/coresight-trace-id.c
index af5b4ef59cea..19005b5b4dc4 100644
--- a/drivers/hwtracing/coresight/coresight-trace-id.c
+++ b/drivers/hwtracing/coresight/coresight-trace-id.c
@@ -3,6 +3,7 @@
* Copyright (c) 2022, Linaro Limited, All rights reserved.
* Author: Mike Leach <[email protected]>
*/
+#include <linux/coresight.h>
#include <linux/coresight-pmu.h>
#include <linux/cpumask.h>
#include <linux/kernel.h>
diff --git a/drivers/hwtracing/coresight/coresight-trace-id.h b/drivers/hwtracing/coresight/coresight-trace-id.h
index 3797777d367e..49438a96fcc6 100644
--- a/drivers/hwtracing/coresight/coresight-trace-id.h
+++ b/drivers/hwtracing/coresight/coresight-trace-id.h
@@ -32,10 +32,6 @@
#include <linux/bitops.h>
#include <linux/types.h>

-
-/* architecturally we have 128 IDs some of which are reserved */
-#define CORESIGHT_TRACE_IDS_MAX 128
-
/* ID 0 is reserved */
#define CORESIGHT_TRACE_ID_RES_0 0

@@ -46,21 +42,6 @@
#define IS_VALID_CS_TRACE_ID(id) \
((id > CORESIGHT_TRACE_ID_RES_0) && (id < CORESIGHT_TRACE_ID_RES_TOP))

-/**
- * Trace ID map.
- *
- * @used_ids: Bitmap to register available (bit = 0) and in use (bit = 1) IDs.
- * Initialised so that the reserved IDs are permanently marked as
- * in use.
- * @pend_rel_ids: CPU IDs that have been released by the trace source but not
- * yet marked as available, to allow re-allocation to the same
- * CPU during a perf session.
- */
-struct coresight_trace_id_map {
- DECLARE_BITMAP(used_ids, CORESIGHT_TRACE_IDS_MAX);
- DECLARE_BITMAP(pend_rel_ids, CORESIGHT_TRACE_IDS_MAX);
-};
-
/* Allocate and release IDs for a single default trace ID map */

/**
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index f09ace92176e..c16c61a8411d 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -218,6 +218,24 @@ struct coresight_sysfs_link {
const char *target_name;
};

+/* architecturally we have 128 IDs some of which are reserved */
+#define CORESIGHT_TRACE_IDS_MAX 128
+
+/**
+ * Trace ID map.
+ *
+ * @used_ids: Bitmap to register available (bit = 0) and in use (bit = 1) IDs.
+ * Initialised so that the reserved IDs are permanently marked as
+ * in use.
+ * @pend_rel_ids: CPU IDs that have been released by the trace source but not
+ * yet marked as available, to allow re-allocation to the same
+ * CPU during a perf session.
+ */
+struct coresight_trace_id_map {
+ DECLARE_BITMAP(used_ids, CORESIGHT_TRACE_IDS_MAX);
+ DECLARE_BITMAP(pend_rel_ids, CORESIGHT_TRACE_IDS_MAX);
+};
+
/**
* struct coresight_device - representation of a device as used by the framework
* @pdata: Platform data with device connections associated to this device.
--
2.34.1

2024-06-11 15:05:46

by James Clark

[permalink] [raw]

Subject: [PATCH v3 04/14] perf: cs-etm: Create decoders based on the trace ID mappings

Now that each queue has a unique set of trace ID mappings, use this
list to create the decoders. This also works the same way for
unformatted where a single dummy entry is added into the trace ID list.

Previously each queue would have a decoder created for each traced CPU
on the system but this won't work anymore because CPUs can have
overlapping trace IDs.

Signed-off-by: James Clark <[email protected]>
---
tools/perf/util/cs-etm.c | 143 +++++++++++++++++++++++----------------
1 file changed, 85 insertions(+), 58 deletions(-)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index be858aed26c4..73fc0ab2fb09 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -268,6 +268,10 @@ static int cs_etm__map_trace_id_v0(struct cs_etm_auxtrace *etm, u8 trace_chan_id
int ret;
struct cs_etm_queue *etmq = etm->queues.queue_array[i].priv;

+ /* Ignore HW_IDs on unformatted queues */
+ if (etmq->formatted_set && !etmq->formatted)
+ continue;
+
ret = cs_etm__insert_trace_id_node(etmq, trace_chan_id,
cpu_metadata);
if (ret)
@@ -673,80 +677,58 @@ static void cs_etm__packet_dump(const char *pkt_string)
}

static void cs_etm__set_trace_param_etmv3(struct cs_etm_trace_params *t_params,
- struct cs_etm_auxtrace *etm, int t_idx,
- int m_idx, u32 etmidr)
+ u64 *metadata, u32 etmidr)
{
- u64 **metadata = etm->metadata;
-
- t_params[t_idx].protocol = cs_etm__get_v7_protocol_version(etmidr);
- t_params[t_idx].etmv3.reg_ctrl = metadata[m_idx][CS_ETM_ETMCR];
- t_params[t_idx].etmv3.reg_trc_id = metadata[m_idx][CS_ETM_ETMTRACEIDR];
+ t_params->protocol = cs_etm__get_v7_protocol_version(etmidr);
+ t_params->etmv3.reg_ctrl = metadata[CS_ETM_ETMCR];
+ t_params->etmv3.reg_trc_id = metadata[CS_ETM_ETMTRACEIDR];
}

static void cs_etm__set_trace_param_etmv4(struct cs_etm_trace_params *t_params,
- struct cs_etm_auxtrace *etm, int t_idx,
- int m_idx)
+ u64 *metadata)
{
- u64 **metadata = etm->metadata;
-
- t_params[t_idx].protocol = CS_ETM_PROTO_ETMV4i;
- t_params[t_idx].etmv4.reg_idr0 = metadata[m_idx][CS_ETMV4_TRCIDR0];
- t_params[t_idx].etmv4.reg_idr1 = metadata[m_idx][CS_ETMV4_TRCIDR1];
- t_params[t_idx].etmv4.reg_idr2 = metadata[m_idx][CS_ETMV4_TRCIDR2];
- t_params[t_idx].etmv4.reg_idr8 = metadata[m_idx][CS_ETMV4_TRCIDR8];
- t_params[t_idx].etmv4.reg_configr = metadata[m_idx][CS_ETMV4_TRCCONFIGR];
- t_params[t_idx].etmv4.reg_traceidr = metadata[m_idx][CS_ETMV4_TRCTRACEIDR];
+ t_params->protocol = CS_ETM_PROTO_ETMV4i;
+ t_params->etmv4.reg_idr0 = metadata[CS_ETMV4_TRCIDR0];
+ t_params->etmv4.reg_idr1 = metadata[CS_ETMV4_TRCIDR1];
+ t_params->etmv4.reg_idr2 = metadata[CS_ETMV4_TRCIDR2];
+ t_params->etmv4.reg_idr8 = metadata[CS_ETMV4_TRCIDR8];
+ t_params->etmv4.reg_configr = metadata[CS_ETMV4_TRCCONFIGR];
+ t_params->etmv4.reg_traceidr = metadata[CS_ETMV4_TRCTRACEIDR];
}

static void cs_etm__set_trace_param_ete(struct cs_etm_trace_params *t_params,
- struct cs_etm_auxtrace *etm, int t_idx,
- int m_idx)
+ u64 *metadata)
{
- u64 **metadata = etm->metadata;
-
- t_params[t_idx].protocol = CS_ETM_PROTO_ETE;
- t_params[t_idx].ete.reg_idr0 = metadata[m_idx][CS_ETE_TRCIDR0];
- t_params[t_idx].ete.reg_idr1 = metadata[m_idx][CS_ETE_TRCIDR1];
- t_params[t_idx].ete.reg_idr2 = metadata[m_idx][CS_ETE_TRCIDR2];
- t_params[t_idx].ete.reg_idr8 = metadata[m_idx][CS_ETE_TRCIDR8];
- t_params[t_idx].ete.reg_configr = metadata[m_idx][CS_ETE_TRCCONFIGR];
- t_params[t_idx].ete.reg_traceidr = metadata[m_idx][CS_ETE_TRCTRACEIDR];
- t_params[t_idx].ete.reg_devarch = metadata[m_idx][CS_ETE_TRCDEVARCH];
+ t_params->protocol = CS_ETM_PROTO_ETE;
+ t_params->ete.reg_idr0 = metadata[CS_ETE_TRCIDR0];
+ t_params->ete.reg_idr1 = metadata[CS_ETE_TRCIDR1];
+ t_params->ete.reg_idr2 = metadata[CS_ETE_TRCIDR2];
+ t_params->ete.reg_idr8 = metadata[CS_ETE_TRCIDR8];
+ t_params->ete.reg_configr = metadata[CS_ETE_TRCCONFIGR];
+ t_params->ete.reg_traceidr = metadata[CS_ETE_TRCTRACEIDR];
+ t_params->ete.reg_devarch = metadata[CS_ETE_TRCDEVARCH];
}

static int cs_etm__init_trace_params(struct cs_etm_trace_params *t_params,
- struct cs_etm_auxtrace *etm,
- bool formatted,
- int sample_cpu,
- int decoders)
-{
- int t_idx, m_idx;
- u32 etmidr;
- u64 architecture;
-
- for (t_idx = 0; t_idx < decoders; t_idx++) {
- if (formatted)
- m_idx = t_idx;
- else {
- m_idx = get_cpu_data_idx(etm, sample_cpu);
- if (m_idx == -1) {
- pr_warning("CS_ETM: unknown CPU, falling back to first metadata\n");
- m_idx = 0;
- }
- }
+ struct cs_etm_queue *etmq)
+{
+ struct int_node *inode;

- architecture = etm->metadata[m_idx][CS_ETM_MAGIC];
+ intlist__for_each_entry(inode, etmq->traceid_list) {
+ u64 *metadata = inode->priv;
+ u64 architecture = metadata[CS_ETM_MAGIC];
+ u32 etmidr;

switch (architecture) {
case __perf_cs_etmv3_magic:
- etmidr = etm->metadata[m_idx][CS_ETM_ETMIDR];
- cs_etm__set_trace_param_etmv3(t_params, etm, t_idx, m_idx, etmidr);
+ etmidr = metadata[CS_ETM_ETMIDR];
+ cs_etm__set_trace_param_etmv3(t_params++, metadata, etmidr);
break;
case __perf_cs_etmv4_magic:
- cs_etm__set_trace_param_etmv4(t_params, etm, t_idx, m_idx);
+ cs_etm__set_trace_param_etmv4(t_params++, metadata);
break;
case __perf_cs_ete_magic:
- cs_etm__set_trace_param_ete(t_params, etm, t_idx, m_idx);
+ cs_etm__set_trace_param_ete(t_params++, metadata);
break;
default:
return -EINVAL;
@@ -2918,6 +2900,42 @@ static u64 *cs_etm__create_meta_blk(u64 *buff_in, int *buff_in_offset,
return metadata;
}

+/*
+ * traceid_list is used to create decoders and give them the trace ID
+ * mappings. In unformatted mode just insert one entry for the sample
+ * CPU so the decoder knows which settings to use.
+ */
+static int cs_etm__map_trace_ids_unformatted(struct cs_etm_auxtrace *etm)
+{
+ for (unsigned int i = 0; i < etm->queues.nr_queues; ++i) {
+ int ret;
+ struct cs_etm_queue *etmq;
+ u8 trace_chan_id;
+ u64 *cpu_data;
+
+ etmq = etm->queues.queue_array[i].priv;
+ if (!etmq->formatted_set || etmq->formatted)
+ continue;
+
+ /* Giving it a real ID doesn't do much but can help with debugging */
+ trace_chan_id = CORESIGHT_LEGACY_CPU_TRACE_ID(i);
+ cpu_data = get_cpu_data(etm, i);
+ if (cpu_data == NULL) {
+ pr_warning("CS_ETM: unknown CPU, falling back to first metadata\n");
+ cpu_data = etm->metadata[0];
+ }
+
+ ret = cs_etm__insert_trace_id_node(etmq, trace_chan_id, cpu_data);
+ if (ret)
+ return ret;
+
+ ret = cs_etm__metadata_set_trace_id(trace_chan_id, cpu_data);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
/**
* Puts a fragment of an auxtrace buffer into the auxtrace queues based
* on the bounds of aux_event, if it matches with the buffer that's at
@@ -3220,21 +3238,26 @@ static int cs_etm__clear_unused_trace_ids_metadata(int num_cpu, u64 **metadata)
static int cs_etm__create_queue_decoders(struct cs_etm_queue *etmq)
{
struct cs_etm_decoder_params d_params;
+ struct cs_etm_trace_params *t_params;
+ int decoders = intlist__nr_entries(etmq->traceid_list);

/*
* Each queue can only contain data from one CPU when unformatted, so only one decoder is
* needed.
*/
- int decoders = etmq->formatted ? etmq->etm->num_cpu : 1;
+ if (etmq->formatted_set && !etmq->formatted)
+ assert(decoders == 1);
+
+ if (decoders == 0)
+ return 0;

/* Use metadata to fill in trace parameters for trace decoder */
- struct cs_etm_trace_params *t_params = zalloc(sizeof(*t_params) * decoders);
+ t_params = zalloc(sizeof(*t_params) * decoders);

if (!t_params)
goto out_free;

- if (cs_etm__init_trace_params(t_params, etmq->etm, etmq->formatted,
- etmq->queue_nr, decoders))
+ if (cs_etm__init_trace_params(t_params, etmq))
goto out_free;

/* Set decoder parameters to decode trace packets */
@@ -3497,6 +3520,10 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
if (err)
goto err_free_queues;

+ err = cs_etm__map_trace_ids_unformatted(etm);
+ if (err)
+ goto err_free_queues;
+
err = cs_etm__create_decoders(etm);
if (err)
goto err_free_queues;
--
2.34.1

2024-06-11 15:08:08

by James Clark

[permalink] [raw]

Subject: [PATCH v3 11/14] coresight: Use per-sink trace ID maps for Perf sessions

This will allow sessions with more than CORESIGHT_TRACE_IDS_MAX ETMs
as long as there are fewer than that many ETMs connected to each sink.

Each sink owns its own trace ID map, and any Perf session connecting to
that sink will allocate from it, even if the sink is currently in use by
other users. This is similar to the existing behavior where the dynamic
trace IDs are constant as long as there is any concurrent Perf session
active. It's not completely optimal because slightly more IDs will be
used than necessary, but the optimal solution involves tracking the PIDs
of each session and allocating ID maps based on the session owner. This
is difficult to do with the combination of per-thread and per-cpu modes
and some scheduling issues. The complexity of this isn't likely to worth
it because even with multiple users they'd just see a difference in the
ordering of ID allocations rather than hitting any limits (unless the
hardware does have too many ETMs connected to one sink).

Signed-off-by: James Clark <[email protected]>
---
drivers/hwtracing/coresight/coresight-core.c | 10 ++++++++++
drivers/hwtracing/coresight/coresight-dummy.c | 3 ++-
drivers/hwtracing/coresight/coresight-etm-perf.c | 15 ++++++++++-----
.../hwtracing/coresight/coresight-etm3x-core.c | 9 +++++----
.../hwtracing/coresight/coresight-etm4x-core.c | 9 +++++----
drivers/hwtracing/coresight/coresight-stm.c | 3 ++-
drivers/hwtracing/coresight/coresight-sysfs.c | 3 ++-
drivers/hwtracing/coresight/coresight-tpdm.c | 3 ++-
include/linux/coresight.h | 3 ++-
9 files changed, 40 insertions(+), 18 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 9fc6f6b863e0..faf560ba8d64 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -902,6 +902,7 @@ static void coresight_device_release(struct device *dev)
struct coresight_device *csdev = to_coresight_device(dev);

fwnode_handle_put(csdev->dev.fwnode);
+ free_percpu(csdev->perf_sink_id_map.cpu_map);
kfree(csdev);
}

@@ -1159,6 +1160,15 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)
csdev->dev.fwnode = fwnode_handle_get(dev_fwnode(desc->dev));
dev_set_name(&csdev->dev, "%s", desc->name);

+ if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
+ csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
+ csdev->perf_sink_id_map.cpu_map = alloc_percpu(atomic_t);
+ if (!csdev->perf_sink_id_map.cpu_map) {
+ kfree(csdev);
+ ret = -ENOMEM;
+ goto err_out;
+ }
+ }
/*
* Make sure the device registration and the connection fixup
* are synchronised, so that we don't see uninitialised devices
diff --git a/drivers/hwtracing/coresight/coresight-dummy.c b/drivers/hwtracing/coresight/coresight-dummy.c
index ac70c0b491be..1f1b9ad160f6 100644
--- a/drivers/hwtracing/coresight/coresight-dummy.c
+++ b/drivers/hwtracing/coresight/coresight-dummy.c
@@ -21,7 +21,8 @@ DEFINE_CORESIGHT_DEVLIST(source_devs, "dummy_source");
DEFINE_CORESIGHT_DEVLIST(sink_devs, "dummy_sink");

static int dummy_source_enable(struct coresight_device *csdev,
- struct perf_event *event, enum cs_mode mode)
+ struct perf_event *event, enum cs_mode mode,
+ __maybe_unused struct coresight_trace_id_map *id_map)
{
dev_dbg(csdev->dev.parent, "Dummy source enabled\n");

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index c0c60e6a1703..7fb55dafb639 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -229,10 +229,13 @@ static void free_event_data(struct work_struct *work)
struct list_head **ppath;

ppath = etm_event_cpu_path_ptr(event_data, cpu);
- if (!(IS_ERR_OR_NULL(*ppath)))
+ if (!(IS_ERR_OR_NULL(*ppath))) {
+ struct coresight_device *sink = coresight_get_sink(*ppath);
+
+ coresight_trace_id_put_cpu_id_map(cpu, &sink->perf_sink_id_map);
coresight_release_path(*ppath);
+ }
*ppath = NULL;
- coresight_trace_id_put_cpu_id(cpu);
}

/* mark perf event as done for trace id allocator */
@@ -401,7 +404,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
}

/* ensure we can allocate a trace ID for this CPU */
- trace_id = coresight_trace_id_get_cpu_id(cpu);
+ trace_id = coresight_trace_id_get_cpu_id_map(cpu, &sink->perf_sink_id_map);
if (!IS_VALID_CS_TRACE_ID(trace_id)) {
cpumask_clear_cpu(cpu, mask);
coresight_release_path(path);
@@ -495,7 +498,8 @@ static void etm_event_start(struct perf_event *event, int flags)
goto fail_end_stop;

/* Finally enable the tracer */
- if (source_ops(csdev)->enable(csdev, event, CS_MODE_PERF))
+ if (source_ops(csdev)->enable(csdev, event, CS_MODE_PERF,
+ &sink->perf_sink_id_map))
goto fail_disable_path;

/*
@@ -507,7 +511,8 @@ static void etm_event_start(struct perf_event *event, int flags)
hw_id = FIELD_PREP(CS_AUX_HW_ID_VERSION_MASK,
CS_AUX_HW_ID_CURR_VERSION);
hw_id |= FIELD_PREP(CS_AUX_HW_ID_TRACE_ID_MASK,
- coresight_trace_id_read_cpu_id(cpu));
+ coresight_trace_id_read_cpu_id_map(cpu,
+ &sink->perf_sink_id_map));
perf_report_aux_output_id(event, hw_id);
}

diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
index 8b362605d242..c103f4c70f5d 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
@@ -481,7 +481,8 @@ void etm_release_trace_id(struct etm_drvdata *drvdata)
}

static int etm_enable_perf(struct coresight_device *csdev,
- struct perf_event *event)
+ struct perf_event *event,
+ struct coresight_trace_id_map *id_map)
{
struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
int trace_id;
@@ -500,7 +501,7 @@ static int etm_enable_perf(struct coresight_device *csdev,
* with perf locks - we know the ID cannot change until perf shuts down
* the session
*/
- trace_id = coresight_trace_id_read_cpu_id(drvdata->cpu);
+ trace_id = coresight_trace_id_read_cpu_id_map(drvdata->cpu, id_map);
if (!IS_VALID_CS_TRACE_ID(trace_id)) {
dev_err(&drvdata->csdev->dev, "Failed to set trace ID for %s on CPU%d\n",
dev_name(&drvdata->csdev->dev), drvdata->cpu);
@@ -553,7 +554,7 @@ static int etm_enable_sysfs(struct coresight_device *csdev)
}

static int etm_enable(struct coresight_device *csdev, struct perf_event *event,
- enum cs_mode mode)
+ enum cs_mode mode, struct coresight_trace_id_map *id_map)
{
int ret;
struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -568,7 +569,7 @@ static int etm_enable(struct coresight_device *csdev, struct perf_event *event,
ret = etm_enable_sysfs(csdev);
break;
case CS_MODE_PERF:
- ret = etm_enable_perf(csdev, event);
+ ret = etm_enable_perf(csdev, event, id_map);
break;
default:
ret = -EINVAL;
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index bf01f01964cf..66d44a404ad0 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -752,7 +752,8 @@ static int etm4_parse_event_config(struct coresight_device *csdev,
}

static int etm4_enable_perf(struct coresight_device *csdev,
- struct perf_event *event)
+ struct perf_event *event,
+ struct coresight_trace_id_map *id_map)
{
int ret = 0, trace_id;
struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -775,7 +776,7 @@ static int etm4_enable_perf(struct coresight_device *csdev,
* with perf locks - we know the ID cannot change until perf shuts down
* the session
*/
- trace_id = coresight_trace_id_read_cpu_id(drvdata->cpu);
+ trace_id = coresight_trace_id_read_cpu_id_map(drvdata->cpu, id_map);
if (!IS_VALID_CS_TRACE_ID(trace_id)) {
dev_err(&drvdata->csdev->dev, "Failed to set trace ID for %s on CPU%d\n",
dev_name(&drvdata->csdev->dev), drvdata->cpu);
@@ -837,7 +838,7 @@ static int etm4_enable_sysfs(struct coresight_device *csdev)
}

static int etm4_enable(struct coresight_device *csdev, struct perf_event *event,
- enum cs_mode mode)
+ enum cs_mode mode, struct coresight_trace_id_map *id_map)
{
int ret;

@@ -851,7 +852,7 @@ static int etm4_enable(struct coresight_device *csdev, struct perf_event *event,
ret = etm4_enable_sysfs(csdev);
break;
case CS_MODE_PERF:
- ret = etm4_enable_perf(csdev, event);
+ ret = etm4_enable_perf(csdev, event, id_map);
break;
default:
ret = -EINVAL;
diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
index 117dbb484543..cb3e04755c99 100644
--- a/drivers/hwtracing/coresight/coresight-stm.c
+++ b/drivers/hwtracing/coresight/coresight-stm.c
@@ -194,7 +194,8 @@ static void stm_enable_hw(struct stm_drvdata *drvdata)
}

static int stm_enable(struct coresight_device *csdev, struct perf_event *event,
- enum cs_mode mode)
+ enum cs_mode mode,
+ __maybe_unused struct coresight_trace_id_map *trace_id)
{
struct stm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);

diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c
index 1e67cc7758d7..a01c9e54e2ed 100644
--- a/drivers/hwtracing/coresight/coresight-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-sysfs.c
@@ -9,6 +9,7 @@
#include <linux/kernel.h>

#include "coresight-priv.h"
+#include "coresight-trace-id.h"

/*
* Use IDR to map the hash of the source's device name
@@ -63,7 +64,7 @@ static int coresight_enable_source_sysfs(struct coresight_device *csdev,
*/
lockdep_assert_held(&coresight_mutex);
if (coresight_get_mode(csdev) != CS_MODE_SYSFS) {
- ret = source_ops(csdev)->enable(csdev, data, mode);
+ ret = source_ops(csdev)->enable(csdev, data, mode, NULL);
if (ret)
return ret;
}
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index 0726f8842552..0a5e20cf23e8 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -439,7 +439,8 @@ static void __tpdm_enable(struct tpdm_drvdata *drvdata)
}

static int tpdm_enable(struct coresight_device *csdev, struct perf_event *event,
- enum cs_mode mode)
+ enum cs_mode mode,
+ __maybe_unused struct coresight_trace_id_map *id_map)
{
struct tpdm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);

diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 7d62b88bfb5c..9c3067e2e38b 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -290,6 +290,7 @@ struct coresight_device {
bool sysfs_sink_activated;
struct dev_ext_attribute *ea;
struct coresight_device *def_sink;
+ struct coresight_trace_id_map perf_sink_id_map;
/* sysfs links between components */
int nr_links;
bool has_conns_grp;
@@ -384,7 +385,7 @@ struct coresight_ops_link {
struct coresight_ops_source {
int (*cpu_id)(struct coresight_device *csdev);
int (*enable)(struct coresight_device *csdev, struct perf_event *event,
- enum cs_mode mode);
+ enum cs_mode mode, struct coresight_trace_id_map *id_map);
void (*disable)(struct coresight_device *csdev,
struct perf_event *event);
};
--
2.34.1

2024-06-11 15:08:36

by James Clark

[permalink] [raw]

Subject: [PATCH v3 13/14] coresight: Emit sink ID in the HW_ID packets

For Perf to be able to decode when per-sink trace IDs are used, emit the
sink that's being written to for each ETM.

Perf currently errors out if it sees a newer packet version so instead
of bumping it, add a new minor version field. This can be used to
signify new versions that have backwards compatible fields. Considering
this change is only for high core count machines, it doesn't make sense
to make a breaking change for everyone.

Signed-off-by: James Clark <[email protected]>
---
drivers/hwtracing/coresight/coresight-core.c | 26 ++++++++++---------
.../hwtracing/coresight/coresight-etm-perf.c | 16 ++++++++----
drivers/hwtracing/coresight/coresight-priv.h | 1 +
include/linux/coresight-pmu.h | 17 +++++++++---
4 files changed, 39 insertions(+), 21 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index faf560ba8d64..c427e9344a84 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -487,23 +487,25 @@ struct coresight_device *coresight_get_sink(struct list_head *path)
return csdev;
}

+u32 coresight_get_sink_id(struct coresight_device *csdev)
+{
+ if (!csdev->ea)
+ return 0;
+
+ /*
+ * See function etm_perf_add_symlink_sink() to know where
+ * this comes from.
+ */
+ return (u32) (unsigned long) csdev->ea->var;
+}
+
static int coresight_sink_by_id(struct device *dev, const void *data)
{
struct coresight_device *csdev = to_coresight_device(dev);
- unsigned long hash;

if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
- csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
-
- if (!csdev->ea)
- return 0;
- /*
- * See function etm_perf_add_symlink_sink() to know where
- * this comes from.
- */
- hash = (unsigned long)csdev->ea->var;
-
- if ((u32)hash == *(u32 *)data)
+ csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
+ if (coresight_get_sink_id(csdev) == *(u32 *)data)
return 1;
}

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 17fa29969643..9bbc41f4b0af 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -453,6 +453,7 @@ static void etm_event_start(struct perf_event *event, int flags)
struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu);
struct list_head *path;
u64 hw_id;
+ u8 trace_id;

if (!csdev)
goto fail;
@@ -505,11 +506,16 @@ static void etm_event_start(struct perf_event *event, int flags)
*/
if (!cpumask_test_cpu(cpu, &event_data->aux_hwid_done)) {
cpumask_set_cpu(cpu, &event_data->aux_hwid_done);
- hw_id = FIELD_PREP(CS_AUX_HW_ID_VERSION_MASK,
- CS_AUX_HW_ID_CURR_VERSION);
- hw_id |= FIELD_PREP(CS_AUX_HW_ID_TRACE_ID_MASK,
- coresight_trace_id_read_cpu_id_map(cpu,
- &sink->perf_sink_id_map));
+
+ trace_id = coresight_trace_id_read_cpu_id_map(cpu, &sink->perf_sink_id_map);
+
+ hw_id = FIELD_PREP(CS_AUX_HW_ID_MAJOR_VERSION_MASK,
+ CS_AUX_HW_ID_MAJOR_VERSION);
+ hw_id |= FIELD_PREP(CS_AUX_HW_ID_MINOR_VERSION_MASK,
+ CS_AUX_HW_ID_MINOR_VERSION);
+ hw_id |= FIELD_PREP(CS_AUX_HW_ID_TRACE_ID_MASK, trace_id);
+ hw_id |= FIELD_PREP(CS_AUX_HW_ID_SINK_ID_MASK, coresight_get_sink_id(sink));
+
perf_report_aux_output_id(event, hw_id);
}

diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index 61a46d3bdcc8..05f891ca6b5c 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -148,6 +148,7 @@ int coresight_make_links(struct coresight_device *orig,
struct coresight_device *target);
void coresight_remove_links(struct coresight_device *orig,
struct coresight_connection *conn);
+u32 coresight_get_sink_id(struct coresight_device *csdev);

#if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM3X)
extern int etm_readl_cp14(u32 off, unsigned int *val);
diff --git a/include/linux/coresight-pmu.h b/include/linux/coresight-pmu.h
index 51ac441a37c3..89b0ac0014b0 100644
--- a/include/linux/coresight-pmu.h
+++ b/include/linux/coresight-pmu.h
@@ -49,12 +49,21 @@
* 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
+ * [39:08] - Sink ID - as reported in /sys/bus/event_source/devices/cs_etm/sinks/
+ * Added in minor version 1.
+ * [55:40] - Unused (SBZ)
+ * [59:56] - Minor Version - previously existing fields are compatible with
+ * all minor versions.
+ * [63:60] - Major Version - previously existing fields mean different things
+ * in new major versions.
*/
#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_SINK_ID_MASK GENMASK_ULL(39, 8)

-#define CS_AUX_HW_ID_CURR_VERSION 0
+#define CS_AUX_HW_ID_MINOR_VERSION_MASK GENMASK_ULL(59, 56)
+#define CS_AUX_HW_ID_MAJOR_VERSION_MASK GENMASK_ULL(63, 60)
+
+#define CS_AUX_HW_ID_MAJOR_VERSION 0
+#define CS_AUX_HW_ID_MINOR_VERSION 1

#endif
--
2.34.1

2024-06-11 15:13:14

by James Clark

[permalink] [raw]

Subject: [PATCH v3 09/14] coresight: Expose map arguments in trace ID API

The trace ID API is currently hard coded to always use the global map.
Add public versions that allow the map to be passed in so that Perf
mode can use per-sink maps. Keep the non-map versions so that sysfs
mode can continue to use the default global map.

System ID functions are unchanged because they will always use the
default map.

Signed-off-by: James Clark <[email protected]>
---
.../hwtracing/coresight/coresight-trace-id.c | 36 ++++++++++++++-----
.../hwtracing/coresight/coresight-trace-id.h | 20 +++++++++--
2 files changed, 45 insertions(+), 11 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-trace-id.c b/drivers/hwtracing/coresight/coresight-trace-id.c
index 19005b5b4dc4..5561989a03fa 100644
--- a/drivers/hwtracing/coresight/coresight-trace-id.c
+++ b/drivers/hwtracing/coresight/coresight-trace-id.c
@@ -12,7 +12,7 @@

#include "coresight-trace-id.h"

-/* Default trace ID map. Used on systems that don't require per sink mappings */
+/* Default trace ID map. Used in sysfs mode and for system sources */
static struct coresight_trace_id_map id_map_default;

/* maintain a record of the mapping of IDs and pending releases per cpu */
@@ -47,7 +47,7 @@ static void coresight_trace_id_dump_table(struct coresight_trace_id_map *id_map,
#endif

/* unlocked read of current trace ID value for given CPU */
-static int _coresight_trace_id_read_cpu_id(int cpu)
+static int _coresight_trace_id_read_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
{
return atomic_read(&per_cpu(cpu_id, cpu));
}
@@ -152,7 +152,7 @@ static void coresight_trace_id_release_all_pending(void)
DUMP_ID_MAP(id_map);
}

-static int coresight_trace_id_map_get_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
+static int _coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
{
unsigned long flags;
int id;
@@ -160,7 +160,7 @@ static int coresight_trace_id_map_get_cpu_id(int cpu, struct coresight_trace_id_
spin_lock_irqsave(&id_map_lock, flags);

/* check for existing allocation for this CPU */
- id = _coresight_trace_id_read_cpu_id(cpu);
+ id = _coresight_trace_id_read_cpu_id(cpu, id_map);
if (id)
goto get_cpu_id_clr_pend;

@@ -196,13 +196,13 @@ static int coresight_trace_id_map_get_cpu_id(int cpu, struct coresight_trace_id_
return id;
}

-static void coresight_trace_id_map_put_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
+static void _coresight_trace_id_put_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
{
unsigned long flags;
int id;

/* check for existing allocation for this CPU */
- id = _coresight_trace_id_read_cpu_id(cpu);
+ id = _coresight_trace_id_read_cpu_id(cpu, id_map);
if (!id)
return;

@@ -254,22 +254,40 @@ static void coresight_trace_id_map_put_system_id(struct coresight_trace_id_map *

int coresight_trace_id_get_cpu_id(int cpu)
{
- return coresight_trace_id_map_get_cpu_id(cpu, &id_map_default);
+ return _coresight_trace_id_get_cpu_id(cpu, &id_map_default);
}
EXPORT_SYMBOL_GPL(coresight_trace_id_get_cpu_id);

+int coresight_trace_id_get_cpu_id_map(int cpu, struct coresight_trace_id_map *id_map)
+{
+ return _coresight_trace_id_get_cpu_id(cpu, id_map);
+}
+EXPORT_SYMBOL_GPL(coresight_trace_id_get_cpu_id_map);
+
void coresight_trace_id_put_cpu_id(int cpu)
{
- coresight_trace_id_map_put_cpu_id(cpu, &id_map_default);
+ _coresight_trace_id_put_cpu_id(cpu, &id_map_default);
}
EXPORT_SYMBOL_GPL(coresight_trace_id_put_cpu_id);

+void coresight_trace_id_put_cpu_id_map(int cpu, struct coresight_trace_id_map *id_map)
+{
+ _coresight_trace_id_put_cpu_id(cpu, id_map);
+}
+EXPORT_SYMBOL_GPL(coresight_trace_id_put_cpu_id_map);
+
int coresight_trace_id_read_cpu_id(int cpu)
{
- return _coresight_trace_id_read_cpu_id(cpu);
+ return _coresight_trace_id_read_cpu_id(cpu, &id_map_default);
}
EXPORT_SYMBOL_GPL(coresight_trace_id_read_cpu_id);

+int coresight_trace_id_read_cpu_id_map(int cpu, struct coresight_trace_id_map *id_map)
+{
+ return _coresight_trace_id_read_cpu_id(cpu, id_map);
+}
+EXPORT_SYMBOL_GPL(coresight_trace_id_read_cpu_id_map);
+
int coresight_trace_id_get_system_id(void)
{
return coresight_trace_id_map_get_system_id(&id_map_default);
diff --git a/drivers/hwtracing/coresight/coresight-trace-id.h b/drivers/hwtracing/coresight/coresight-trace-id.h
index 49438a96fcc6..840babdd0794 100644
--- a/drivers/hwtracing/coresight/coresight-trace-id.h
+++ b/drivers/hwtracing/coresight/coresight-trace-id.h
@@ -42,8 +42,6 @@
#define IS_VALID_CS_TRACE_ID(id) \
((id > CORESIGHT_TRACE_ID_RES_0) && (id < CORESIGHT_TRACE_ID_RES_TOP))

-/* Allocate and release IDs for a single default trace ID map */
-
/**
* Read and optionally allocate a CoreSight trace ID and associate with a CPU.
*
@@ -59,6 +57,12 @@
*/
int coresight_trace_id_get_cpu_id(int cpu);

+/**
+ * Version of coresight_trace_id_get_cpu_id() that allows the ID map to operate
+ * on to be provided.
+ */
+int coresight_trace_id_get_cpu_id_map(int cpu, struct coresight_trace_id_map *id_map);
+
/**
* Release an allocated trace ID associated with the CPU.
*
@@ -72,6 +76,12 @@ int coresight_trace_id_get_cpu_id(int cpu);
*/
void coresight_trace_id_put_cpu_id(int cpu);

+/**
+ * Version of coresight_trace_id_put_cpu_id() that allows the ID map to operate
+ * on to be provided.
+ */
+void coresight_trace_id_put_cpu_id_map(int cpu, struct coresight_trace_id_map *id_map);
+
/**
* Read the current allocated CoreSight Trace ID value for the CPU.
*
@@ -92,6 +102,12 @@ void coresight_trace_id_put_cpu_id(int cpu);
*/
int coresight_trace_id_read_cpu_id(int cpu);

+/**
+ * Version of coresight_trace_id_read_cpu_id() that allows the ID map to operate
+ * on to be provided.
+ */
+int coresight_trace_id_read_cpu_id_map(int cpu, struct coresight_trace_id_map *id_map);
+
/**
* Allocate a CoreSight trace ID for a system component.
*
--
2.34.1

2024-06-11 15:13:50

by James Clark

[permalink] [raw]

Subject: [PATCH v3 10/14] coresight: Make CPU id map a property of a trace ID map

The global CPU ID mappings won't work for per-sink ID maps so move it to
the ID map struct. coresight_trace_id_release_all_pending() is hard
coded to operate on the default map, but once Perf sessions use their
own maps the pending release mechanism will be deleted. So it doesn't
need to be extended to accept a trace ID map argument at this point.

Signed-off-by: James Clark <[email protected]>
---
drivers/hwtracing/coresight/coresight-trace-id.c | 16 +++++++++-------
include/linux/coresight.h | 1 +
2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-trace-id.c b/drivers/hwtracing/coresight/coresight-trace-id.c
index 5561989a03fa..8a777c0af6ea 100644
--- a/drivers/hwtracing/coresight/coresight-trace-id.c
+++ b/drivers/hwtracing/coresight/coresight-trace-id.c
@@ -13,10 +13,12 @@
#include "coresight-trace-id.h"

/* Default trace ID map. Used in sysfs mode and for system sources */
-static struct coresight_trace_id_map id_map_default;
+static DEFINE_PER_CPU(atomic_t, id_map_default_cpu_ids) = ATOMIC_INIT(0);
+static struct coresight_trace_id_map id_map_default = {
+ .cpu_map = &id_map_default_cpu_ids
+};

-/* maintain a record of the mapping of IDs and pending releases per cpu */
-static DEFINE_PER_CPU(atomic_t, cpu_id) = ATOMIC_INIT(0);
+/* maintain a record of the pending releases per cpu */
static cpumask_t cpu_id_release_pending;

/* perf session active counter */
@@ -49,7 +51,7 @@ static void coresight_trace_id_dump_table(struct coresight_trace_id_map *id_map,
/* unlocked read of current trace ID value for given CPU */
static int _coresight_trace_id_read_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
{
- return atomic_read(&per_cpu(cpu_id, cpu));
+ return atomic_read(per_cpu_ptr(id_map->cpu_map, cpu));
}

/* look for next available odd ID, return 0 if none found */
@@ -145,7 +147,7 @@ static void coresight_trace_id_release_all_pending(void)
clear_bit(bit, id_map->pend_rel_ids);
}
for_each_cpu(cpu, &cpu_id_release_pending) {
- atomic_set(&per_cpu(cpu_id, cpu), 0);
+ atomic_set(per_cpu_ptr(id_map_default.cpu_map, cpu), 0);
cpumask_clear_cpu(cpu, &cpu_id_release_pending);
}
spin_unlock_irqrestore(&id_map_lock, flags);
@@ -181,7 +183,7 @@ static int _coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map
goto get_cpu_id_out_unlock;

/* allocate the new id to the cpu */
- atomic_set(&per_cpu(cpu_id, cpu), id);
+ atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), id);

get_cpu_id_clr_pend:
/* we are (re)using this ID - so ensure it is not marked for release */
@@ -215,7 +217,7 @@ static void _coresight_trace_id_put_cpu_id(int cpu, struct coresight_trace_id_ma
} else {
/* otherwise clear id */
coresight_trace_id_free(id, id_map);
- atomic_set(&per_cpu(cpu_id, cpu), 0);
+ atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);
}

spin_unlock_irqrestore(&id_map_lock, flags);
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index c16c61a8411d..7d62b88bfb5c 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -234,6 +234,7 @@ struct coresight_sysfs_link {
struct coresight_trace_id_map {
DECLARE_BITMAP(used_ids, CORESIGHT_TRACE_IDS_MAX);
DECLARE_BITMAP(pend_rel_ids, CORESIGHT_TRACE_IDS_MAX);
+ atomic_t __percpu *cpu_map;
};

/**
--
2.34.1

2024-06-11 15:13:56

by James Clark

[permalink] [raw]

Subject: [PATCH v3 12/14] coresight: Remove pending trace ID release mechanism

Pending the release of IDs was a way of managing concurrent sysfs and
Perf sessions in a single global ID map. Perf may have finished while
sysfs hadn't, and Perf shouldn't release the IDs in use by sysfs and
vice versa.

Now that Perf uses its own exclusive ID maps, pending release doesn't
result in any different behavior than just releasing all IDs when the
last Perf session finishes. As part of the per-sink trace ID change, we
would have still had to make the pending mechanism work on a per-sink
basis, due to the overlapping ID allocations, so instead of making that
more complicated, just remove it.

Signed-off-by: James Clark <[email protected]>
---
.../hwtracing/coresight/coresight-etm-perf.c | 11 ++--
.../hwtracing/coresight/coresight-trace-id.c | 62 +++++--------------
.../hwtracing/coresight/coresight-trace-id.h | 31 +++++-----
include/linux/coresight.h | 6 +-
4 files changed, 34 insertions(+), 76 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 7fb55dafb639..17fa29969643 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -232,15 +232,14 @@ static void free_event_data(struct work_struct *work)
if (!(IS_ERR_OR_NULL(*ppath))) {
struct coresight_device *sink = coresight_get_sink(*ppath);

- coresight_trace_id_put_cpu_id_map(cpu, &sink->perf_sink_id_map);
+ /* mark perf event as done for trace id allocator */
+ coresight_trace_id_perf_stop(&sink->perf_sink_id_map);
+
coresight_release_path(*ppath);
}
*ppath = NULL;
}

- /* mark perf event as done for trace id allocator */
- coresight_trace_id_perf_stop();
-
free_percpu(event_data->path);
kfree(event_data);
}
@@ -328,9 +327,6 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
sink = user_sink = coresight_get_sink_by_id(id);
}

- /* tell the trace ID allocator that a perf event is starting up */
- coresight_trace_id_perf_start();
-
/* check if user wants a coresight configuration selected */
cfg_hash = (u32)((event->attr.config2 & GENMASK_ULL(63, 32)) >> 32);
if (cfg_hash) {
@@ -411,6 +407,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
continue;
}

+ coresight_trace_id_perf_start(&sink->perf_sink_id_map);
*etm_event_cpu_path_ptr(event_data, cpu) = path;
}

diff --git a/drivers/hwtracing/coresight/coresight-trace-id.c b/drivers/hwtracing/coresight/coresight-trace-id.c
index 8a777c0af6ea..1e70892f5beb 100644
--- a/drivers/hwtracing/coresight/coresight-trace-id.c
+++ b/drivers/hwtracing/coresight/coresight-trace-id.c
@@ -18,12 +18,6 @@ static struct coresight_trace_id_map id_map_default = {
.cpu_map = &id_map_default_cpu_ids
};

-/* maintain a record of the pending releases per cpu */
-static cpumask_t cpu_id_release_pending;
-
-/* perf session active counter */
-static atomic_t perf_cs_etm_session_active = ATOMIC_INIT(0);
-
/* lock to protect id_map and cpu data */
static DEFINE_SPINLOCK(id_map_lock);

@@ -122,34 +116,18 @@ static void coresight_trace_id_free(int id, struct coresight_trace_id_map *id_ma
clear_bit(id, id_map->used_ids);
}

-static void coresight_trace_id_set_pend_rel(int id, struct coresight_trace_id_map *id_map)
-{
- if (WARN(!IS_VALID_CS_TRACE_ID(id), "Invalid Trace ID %d\n", id))
- return;
- set_bit(id, id_map->pend_rel_ids);
-}
-
/*
- * release all pending IDs for all current maps & clear CPU associations
- *
- * This currently operates on the default id map, but may be extended to
- * operate on all registered id maps if per sink id maps are used.
+ * Release all IDs and clear CPU associations.
*/
-static void coresight_trace_id_release_all_pending(void)
+static void coresight_trace_id_release_all(struct coresight_trace_id_map *id_map)
{
- struct coresight_trace_id_map *id_map = &id_map_default;
unsigned long flags;
- int cpu, bit;
+ int cpu;

spin_lock_irqsave(&id_map_lock, flags);
- for_each_set_bit(bit, id_map->pend_rel_ids, CORESIGHT_TRACE_ID_RES_TOP) {
- clear_bit(bit, id_map->used_ids);
- clear_bit(bit, id_map->pend_rel_ids);
- }
- for_each_cpu(cpu, &cpu_id_release_pending) {
- atomic_set(per_cpu_ptr(id_map_default.cpu_map, cpu), 0);
- cpumask_clear_cpu(cpu, &cpu_id_release_pending);
- }
+ bitmap_zero(id_map->used_ids, CORESIGHT_TRACE_IDS_MAX);
+ for_each_possible_cpu(cpu)
+ atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);
spin_unlock_irqrestore(&id_map_lock, flags);
DUMP_ID_MAP(id_map);
}
@@ -164,7 +142,7 @@ static int _coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map
/* check for existing allocation for this CPU */
id = _coresight_trace_id_read_cpu_id(cpu, id_map);
if (id)
- goto get_cpu_id_clr_pend;
+ goto get_cpu_id_out_unlock;

/*
* Find a new ID.
@@ -185,11 +163,6 @@ static int _coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map
/* allocate the new id to the cpu */
atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), id);

-get_cpu_id_clr_pend:
- /* we are (re)using this ID - so ensure it is not marked for release */
- cpumask_clear_cpu(cpu, &cpu_id_release_pending);
- clear_bit(id, id_map->pend_rel_ids);
-
get_cpu_id_out_unlock:
spin_unlock_irqrestore(&id_map_lock, flags);

@@ -210,15 +183,8 @@ static void _coresight_trace_id_put_cpu_id(int cpu, struct coresight_trace_id_ma

spin_lock_irqsave(&id_map_lock, flags);

- if (atomic_read(&perf_cs_etm_session_active)) {
- /* set release at pending if perf still active */
- coresight_trace_id_set_pend_rel(id, id_map);
- cpumask_set_cpu(cpu, &cpu_id_release_pending);
- } else {
- /* otherwise clear id */
- coresight_trace_id_free(id, id_map);
- atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);
- }
+ coresight_trace_id_free(id, id_map);
+ atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);

spin_unlock_irqrestore(&id_map_lock, flags);
DUMP_ID_CPU(cpu, id);
@@ -302,17 +268,17 @@ void coresight_trace_id_put_system_id(int id)
}
EXPORT_SYMBOL_GPL(coresight_trace_id_put_system_id);

-void coresight_trace_id_perf_start(void)
+void coresight_trace_id_perf_start(struct coresight_trace_id_map *id_map)
{
- atomic_inc(&perf_cs_etm_session_active);
+ atomic_inc(&id_map->perf_cs_etm_session_active);
PERF_SESSION(atomic_read(&perf_cs_etm_session_active));
}
EXPORT_SYMBOL_GPL(coresight_trace_id_perf_start);

-void coresight_trace_id_perf_stop(void)
+void coresight_trace_id_perf_stop(struct coresight_trace_id_map *id_map)
{
- if (!atomic_dec_return(&perf_cs_etm_session_active))
- coresight_trace_id_release_all_pending();
+ if (!atomic_dec_return(&id_map->perf_cs_etm_session_active))
+ coresight_trace_id_release_all(id_map);
PERF_SESSION(atomic_read(&perf_cs_etm_session_active));
}
EXPORT_SYMBOL_GPL(coresight_trace_id_perf_stop);
diff --git a/drivers/hwtracing/coresight/coresight-trace-id.h b/drivers/hwtracing/coresight/coresight-trace-id.h
index 840babdd0794..9aae50a553ca 100644
--- a/drivers/hwtracing/coresight/coresight-trace-id.h
+++ b/drivers/hwtracing/coresight/coresight-trace-id.h
@@ -17,9 +17,10 @@
* released when done.
*
* In order to ensure that a consistent cpu / ID matching is maintained
- * throughout a perf cs_etm event session - a session in progress flag will
- * be maintained, and released IDs not cleared until the perf session is
- * complete. This allows the same CPU to be re-allocated its prior ID.
+ * throughout a perf cs_etm event session - a session in progress flag will be
+ * maintained for each sink, and IDs are cleared when all the perf sessions
+ * complete. This allows the same CPU to be re-allocated its prior ID when
+ * events are scheduled in and out.
*
*
* Trace ID maps will be created and initialised to prevent architecturally
@@ -66,11 +67,7 @@ int coresight_trace_id_get_cpu_id_map(int cpu, struct coresight_trace_id_map *id
/**
* Release an allocated trace ID associated with the CPU.
*
- * This will release the CoreSight trace ID associated with the CPU,
- * unless a perf session is in operation.
- *
- * If a perf session is in operation then the ID will be marked as pending
- * release.
+ * This will release the CoreSight trace ID associated with the CPU.
*
* @cpu: The CPU index to release the associated trace ID.
*/
@@ -133,21 +130,21 @@ void coresight_trace_id_put_system_id(int id);
/**
* Notify the Trace ID allocator that a perf session is starting.
*
- * Increase the perf session reference count - called by perf when setting up
- * a trace event.
+ * Increase the perf session reference count - called by perf when setting up a
+ * trace event.
*
- * This reference count is used by the ID allocator to ensure that trace IDs
- * associated with a CPU cannot change or be released during a perf session.
+ * Perf sessions never free trace IDs to ensure that the ID associated with a
+ * CPU cannot change during their and other's concurrent sessions. Instead,
+ * this refcount is used so that the last event to finish always frees all IDs.
*/
-void coresight_trace_id_perf_start(void);
+void coresight_trace_id_perf_start(struct coresight_trace_id_map *id_map);

/**
* Notify the ID allocator that a perf session is stopping.
*
- * Decrease the perf session reference count.
- * if this causes the count to go to zero, then all Trace IDs marked as pending
- * release, will be released.
+ * Decrease the perf session reference count. If this causes the count to go to
+ * zero, then all Trace IDs will be released.
*/
-void coresight_trace_id_perf_stop(void);
+void coresight_trace_id_perf_stop(struct coresight_trace_id_map *id_map);

#endif /* _CORESIGHT_TRACE_ID_H */
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 9c3067e2e38b..197949fd2c35 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -227,14 +227,12 @@ struct coresight_sysfs_link {
* @used_ids: Bitmap to register available (bit = 0) and in use (bit = 1) IDs.
* Initialised so that the reserved IDs are permanently marked as
* in use.
- * @pend_rel_ids: CPU IDs that have been released by the trace source but not
- * yet marked as available, to allow re-allocation to the same
- * CPU during a perf session.
+ * @perf_cs_etm_session_active: Number of Perf sessions using this ID map.
*/
struct coresight_trace_id_map {
DECLARE_BITMAP(used_ids, CORESIGHT_TRACE_IDS_MAX);
- DECLARE_BITMAP(pend_rel_ids, CORESIGHT_TRACE_IDS_MAX);
atomic_t __percpu *cpu_map;
+ atomic_t perf_cs_etm_session_active;
};

/**
--
2.34.1

2024-06-11 15:14:05

by James Clark

[permalink] [raw]

Subject: [PATCH v3 14/14] coresight: Make trace ID map spinlock local to the map

Reduce contention on the lock by replacing the global lock with one for
each map.

Signed-off-by: James Clark <[email protected]>
---
drivers/hwtracing/coresight/coresight-core.c | 1 +
.../hwtracing/coresight/coresight-trace-id.c | 26 +++++++++----------
include/linux/coresight.h | 1 +
3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index c427e9344a84..ea38ecf26fcb 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -1164,6 +1164,7 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)

if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
+ spin_lock_init(&csdev->perf_sink_id_map.lock);
csdev->perf_sink_id_map.cpu_map = alloc_percpu(atomic_t);
if (!csdev->perf_sink_id_map.cpu_map) {
kfree(csdev);
diff --git a/drivers/hwtracing/coresight/coresight-trace-id.c b/drivers/hwtracing/coresight/coresight-trace-id.c
index 1e70892f5beb..82bb70c1ad73 100644
--- a/drivers/hwtracing/coresight/coresight-trace-id.c
+++ b/drivers/hwtracing/coresight/coresight-trace-id.c
@@ -15,12 +15,10 @@
/* Default trace ID map. Used in sysfs mode and for system sources */
static DEFINE_PER_CPU(atomic_t, id_map_default_cpu_ids) = ATOMIC_INIT(0);
static struct coresight_trace_id_map id_map_default = {
- .cpu_map = &id_map_default_cpu_ids
+ .cpu_map = &id_map_default_cpu_ids,
+ .lock = __SPIN_LOCK_UNLOCKED(id_map_default.lock)
};

-/* lock to protect id_map and cpu data */
-static DEFINE_SPINLOCK(id_map_lock);
-
/* #define TRACE_ID_DEBUG 1 */
#if defined(TRACE_ID_DEBUG) || defined(CONFIG_COMPILE_TEST)

@@ -124,11 +122,11 @@ static void coresight_trace_id_release_all(struct coresight_trace_id_map *id_map
unsigned long flags;
int cpu;

- spin_lock_irqsave(&id_map_lock, flags);
+ spin_lock_irqsave(&id_map->lock, flags);
bitmap_zero(id_map->used_ids, CORESIGHT_TRACE_IDS_MAX);
for_each_possible_cpu(cpu)
atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);
- spin_unlock_irqrestore(&id_map_lock, flags);
+ spin_unlock_irqrestore(&id_map->lock, flags);
DUMP_ID_MAP(id_map);
}

@@ -137,7 +135,7 @@ static int _coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map
unsigned long flags;
int id;

- spin_lock_irqsave(&id_map_lock, flags);
+ spin_lock_irqsave(&id_map->lock, flags);

/* check for existing allocation for this CPU */
id = _coresight_trace_id_read_cpu_id(cpu, id_map);
@@ -164,7 +162,7 @@ static int _coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map
atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), id);

get_cpu_id_out_unlock:
- spin_unlock_irqrestore(&id_map_lock, flags);
+ spin_unlock_irqrestore(&id_map->lock, flags);

DUMP_ID_CPU(cpu, id);
DUMP_ID_MAP(id_map);
@@ -181,12 +179,12 @@ static void _coresight_trace_id_put_cpu_id(int cpu, struct coresight_trace_id_ma
if (!id)
return;

- spin_lock_irqsave(&id_map_lock, flags);
+ spin_lock_irqsave(&id_map->lock, flags);

coresight_trace_id_free(id, id_map);
atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);

- spin_unlock_irqrestore(&id_map_lock, flags);
+ spin_unlock_irqrestore(&id_map->lock, flags);
DUMP_ID_CPU(cpu, id);
DUMP_ID_MAP(id_map);
}
@@ -196,10 +194,10 @@ static int coresight_trace_id_map_get_system_id(struct coresight_trace_id_map *i
unsigned long flags;
int id;

- spin_lock_irqsave(&id_map_lock, flags);
+ spin_lock_irqsave(&id_map->lock, flags);
/* prefer odd IDs for system components to avoid legacy CPU IDS */
id = coresight_trace_id_alloc_new_id(id_map, 0, true);
- spin_unlock_irqrestore(&id_map_lock, flags);
+ spin_unlock_irqrestore(&id_map->lock, flags);

DUMP_ID(id);
DUMP_ID_MAP(id_map);
@@ -210,9 +208,9 @@ static void coresight_trace_id_map_put_system_id(struct coresight_trace_id_map *
{
unsigned long flags;

- spin_lock_irqsave(&id_map_lock, flags);
+ spin_lock_irqsave(&id_map->lock, flags);
coresight_trace_id_free(id, id_map);
- spin_unlock_irqrestore(&id_map_lock, flags);
+ spin_unlock_irqrestore(&id_map->lock, flags);

DUMP_ID(id);
DUMP_ID_MAP(id_map);
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 197949fd2c35..c13342594278 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -233,6 +233,7 @@ struct coresight_trace_id_map {
DECLARE_BITMAP(used_ids, CORESIGHT_TRACE_IDS_MAX);
atomic_t __percpu *cpu_map;
atomic_t perf_cs_etm_session_active;
+ spinlock_t lock;
};

/**
--
2.34.1