Re: [PATCH v8 1/3] perf: cs-etm: Move mapping of Trace ID and cpu into helper function

From: Arnaldo Carvalho de Melo
Date: Wed Mar 29 2023 - 08:41:19 EST


Em Wed, Mar 29, 2023 at 12:14:20PM +0100, Mike Leach escreveu:
> The information to associate Trace ID and CPU will be changing.
>
> Drivers will start outputting this as a hardware ID packet in the data
> file which if present will be used in preference to the AUXINFO values.

CC /tmp/build/perf-tools-next/util/symbol-elf.o
LD /tmp/build/perf-tools-next/util/cs-etm-decoder/perf-in.o
util/cs-etm.c: In function ‘cs_etm__process_auxtrace_info_full’:
util/cs-etm.c:2866:26: error: unused variable ‘inode’ [-Werror=unused-variable]
2866 | struct int_node *inode;
| ^~~~~
cc1: all warnings being treated as errors
make[4]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:97: /tmp/build/perf-tools-next/util/cs-etm.o] Error 1
make[4]: *** Waiting for unfinished jobs....
gmake[3]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:140: util] Err

Trying to fix...

> To prepare for this we provide a helper functions to do the individual ID
> mapping, and one to extract the IDs from the completed metadata blocks.
>
> Signed-off-by: Mike Leach <mike.leach@xxxxxxxxxx>
> Reviewed-by: James Clark <james.clark@xxxxxxx>
> Acked-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> ---
> tools/include/linux/coresight-pmu.h | 5 ++
> tools/perf/util/cs-etm.c | 91 +++++++++++++++++++----------
> tools/perf/util/cs-etm.h | 14 ++++-
> 3 files changed, 77 insertions(+), 33 deletions(-)
>
> diff --git a/tools/include/linux/coresight-pmu.h b/tools/include/linux/coresight-pmu.h
> index 6c2fd6cc5a98..db9c7c0abb6a 100644
> --- a/tools/include/linux/coresight-pmu.h
> +++ b/tools/include/linux/coresight-pmu.h
> @@ -7,9 +7,14 @@
> #ifndef _LINUX_CORESIGHT_PMU_H
> #define _LINUX_CORESIGHT_PMU_H
>
> +#include <linux/bits.h>
> +
> #define CORESIGHT_ETM_PMU_NAME "cs_etm"
> #define CORESIGHT_ETM_PMU_SEED 0x10
>
> +/* CoreSight trace ID is currently the bottom 7 bits of the value */
> +#define CORESIGHT_TRACE_ID_VAL_MASK GENMASK(6, 0)
> +
> /*
> * Below are the definition of bit offsets for perf option, and works as
> * arbitrary values for all ETM versions.
> diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
> index f65bac5ddbdb..f6ca07f68b25 100644
> --- a/tools/perf/util/cs-etm.c
> +++ b/tools/perf/util/cs-etm.c
> @@ -196,6 +196,30 @@ int cs_etm__get_pid_fmt(u8 trace_chan_id, u64 *pid_fmt)
> return 0;
> }
>
> +static int cs_etm__map_trace_id(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);
> +
> + /* 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;
> +
> + /* All good, associate the traceID with the metadata pointer */
> + inode->priv = cpu_metadata;
> +
> + return 0;
> +}
> +
> void cs_etm__etmq_set_traceid_queue_timestamp(struct cs_etm_queue *etmq,
> u8 trace_chan_id)
> {
> @@ -2804,6 +2828,36 @@ static bool cs_etm__has_virtual_ts(u64 **metadata, int num_cpu)
> return true;
> }
>
> +/* map trace ids to correct metadata block, from information in metadata */
> +static int cs_etm__map_trace_ids_metadata(int num_cpu, u64 **metadata)
> +{
> + u64 cs_etm_magic;
> + u8 trace_chan_id;
> + int i, err;
> +
> + for (i = 0; i < num_cpu; i++) {
> + cs_etm_magic = metadata[i][CS_ETM_MAGIC];
> + switch (cs_etm_magic) {
> + case __perf_cs_etmv3_magic:
> + trace_chan_id = (u8)((metadata[i][CS_ETM_ETMTRACEIDR]) &
> + CORESIGHT_TRACE_ID_VAL_MASK);
> + break;
> + case __perf_cs_etmv4_magic:
> + case __perf_cs_ete_magic:
> + trace_chan_id = (u8)((metadata[i][CS_ETMV4_TRCTRACEIDR]) &
> + CORESIGHT_TRACE_ID_VAL_MASK);
> + break;
> + default:
> + /* unknown magic number */
> + return -EINVAL;
> + }
> + err = cs_etm__map_trace_id(trace_chan_id, metadata[i]);
> + if (err)
> + return err;
> + }
> + return 0;
> +}
> +
> int cs_etm__process_auxtrace_info_full(union perf_event *event,
> struct perf_session *session)
> {
> @@ -2814,7 +2868,7 @@ 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, trcidr_idx;
> + int num_cpu;
> int err = 0;
> int i, j;
> u64 *ptr = NULL;
> @@ -2853,23 +2907,13 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
> cs_etm__create_meta_blk(ptr, &i,
> CS_ETM_PRIV_MAX,
> CS_ETM_NR_TRC_PARAMS_V0);
> -
> - /* The traceID is our handle */
> - trcidr_idx = CS_ETM_ETMTRACEIDR;
> -
> } else if (ptr[i] == __perf_cs_etmv4_magic) {
> metadata[j] =
> cs_etm__create_meta_blk(ptr, &i,
> CS_ETMV4_PRIV_MAX,
> CS_ETMV4_NR_TRC_PARAMS_V0);
> -
> - /* The traceID is our handle */
> - trcidr_idx = CS_ETMV4_TRCTRACEIDR;
> } else if (ptr[i] == __perf_cs_ete_magic) {
> metadata[j] = cs_etm__create_meta_blk(ptr, &i, CS_ETE_PRIV_MAX, -1);
> -
> - /* ETE shares first part of metadata with ETMv4 */
> - trcidr_idx = CS_ETMV4_TRCTRACEIDR;
> } else {
> ui__error("CS ETM Trace: Unrecognised magic number %#"PRIx64". File could be from a newer version of perf.\n",
> ptr[i]);
> @@ -2881,26 +2925,6 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
> err = -ENOMEM;
> goto err_free_metadata;
> }
> -
> - /* Get an RB node for this CPU */
> - inode = intlist__findnew(traceid_list, metadata[j][trcidr_idx]);
> -
> - /* Something went wrong, no need to continue */
> - if (!inode) {
> - err = -ENOMEM;
> - goto err_free_metadata;
> - }
> -
> - /*
> - * The node for that CPU should not be taken.
> - * Back out if that's the case.
> - */
> - if (inode->priv) {
> - err = -EINVAL;
> - goto err_free_metadata;
> - }
> - /* All good, associate the traceID with the metadata pointer */
> - inode->priv = metadata[j];
> }
>
> /*
> @@ -2994,6 +3018,11 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
> if (err)
> goto err_delete_thread;
>
> + /* before aux records are queued, need to map metadata to trace IDs */
> + err = cs_etm__map_trace_ids_metadata(num_cpu, metadata);
> + if (err)
> + goto err_delete_thread;
> +
> err = cs_etm__queue_aux_records(session);
> if (err)
> goto err_delete_thread;
> diff --git a/tools/perf/util/cs-etm.h b/tools/perf/util/cs-etm.h
> index 98a4f7113d2f..6d3078e042b4 100644
> --- a/tools/perf/util/cs-etm.h
> +++ b/tools/perf/util/cs-etm.h
> @@ -29,13 +29,17 @@ enum {
> /*
> * Update the version for new format.
> *
> - * New version 1 format adds a param count to the per cpu metadata.
> + * Version 1: format adds a param count to the per cpu metadata.
> * This allows easy adding of new metadata parameters.
> * Requires that new params always added after current ones.
> * Also allows client reader to handle file versions that are different by
> * checking the number of params in the file vs the number expected.
> + *
> + * Version 2: Drivers will use PERF_RECORD_AUX_OUTPUT_HW_ID to output
> + * CoreSight Trace ID. ...TRACEIDR metadata will be set to unused ID.
> */
> -#define CS_HEADER_CURRENT_VERSION 1
> +#define CS_HEADER_CURRENT_VERSION 2
> +#define CS_AUX_HW_ID_VERSION_MIN 2
>
> /* Beginning of header common to both ETMv3 and V4 */
> enum {
> @@ -97,6 +101,12 @@ enum {
> CS_ETE_PRIV_MAX
> };
>
> +/*
> + * Check for valid CoreSight trace ID. If an invalid value is present in the metadata,
> + * then IDs are present in the hardware ID packet in the data file.
> + */
> +#define CS_IS_VALID_TRACE_ID(id) ((id > 0) && (id < 0x70))
> +
> /*
> * ETMv3 exception encoding number:
> * See Embedded Trace Macrocell specification (ARM IHI 0014Q)
> --
> 2.32.0
>

--

- Arnaldo