Re: [PATCH v2 1/4] Coresight: Add trace_id function to collect trace ID

From: Mike Leach
Date: Tue Jul 23 2024 - 06:30:24 EST


Hi,

This patch has a number of issues:-

1) The new dynamic trace ID patchset to use per sink ID maps makes
this set unusable. perf supplies a trace ID map for each sink used.
- see https://lists.linaro.org/archives/list/coresight@xxxxxxxxxxxxxxxx/thread/JEK7M7HRS57XK4B7CVTVFSHFAFBX4SFG/

2) See etm4_enable_perf() - in the perf context a locked version of
the read trace ID cannot be used - therefore any path that calls
etm4_read_alloc_trace_id() (or equivalent for other sources) in perf
mode may result in lockdep issues.

3) on enable: given a cpu number, the trace ID can be read from the
id maps rather than needing a new function in ops

4) on disable: trace id can be read directly from the source driver
data - again removing need for a new trace_id function in ops.

Regards

Mike


On Fri, 5 Jul 2024 at 10:01, Jie Gan <quic_jiegan@xxxxxxxxxxx> wrote:
>
> Add 'trace_id' function pointer in ops. It's responsible for collect the
> trace ID of the device.
>
> Add 'struct cs_sink_data' to store the data used by coresight_enable_path/
> coresight_disable_path. The structure will be transmitted to the helper and
> sink device.
>
> Signed-off-by: Jie Gan <quic_jiegan@xxxxxxxxxxx>
> ---
> drivers/hwtracing/coresight/coresight-core.c | 53 +++++++++++++++----
> drivers/hwtracing/coresight/coresight-etb10.c | 3 +-
> .../hwtracing/coresight/coresight-etm-perf.c | 34 ++++++++++--
> .../coresight/coresight-etm3x-core.c | 14 +++++
> .../coresight/coresight-etm4x-core.c | 13 +++++
> drivers/hwtracing/coresight/coresight-priv.h | 12 ++++-
> drivers/hwtracing/coresight/coresight-stm.c | 13 +++++
> drivers/hwtracing/coresight/coresight-sysfs.c | 24 +++++++--
> .../hwtracing/coresight/coresight-tmc-etf.c | 3 +-
> .../hwtracing/coresight/coresight-tmc-etr.c | 6 ++-
> drivers/hwtracing/coresight/coresight-tpda.c | 13 +++++
> drivers/hwtracing/coresight/coresight-trbe.c | 4 +-
> drivers/hwtracing/coresight/ultrasoc-smb.c | 3 +-
> include/linux/coresight.h | 4 ++
> 14 files changed, 174 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
> index 9fc6f6b863e0..f414e66f4cda 100644
> --- a/drivers/hwtracing/coresight/coresight-core.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -297,12 +297,12 @@ static int coresight_enable_helper(struct coresight_device *csdev,
> return helper_ops(csdev)->enable(csdev, mode, data);
> }
>
> -static void coresight_disable_helper(struct coresight_device *csdev)
> +static void coresight_disable_helper(struct coresight_device *csdev, void *data)
> {
> - helper_ops(csdev)->disable(csdev, NULL);
> + helper_ops(csdev)->disable(csdev, data);
> }
>
> -static void coresight_disable_helpers(struct coresight_device *csdev)
> +static void coresight_disable_helpers(struct coresight_device *csdev, void *data)
> {
> int i;
> struct coresight_device *helper;
> @@ -310,7 +310,7 @@ static void coresight_disable_helpers(struct coresight_device *csdev)
> for (i = 0; i < csdev->pdata->nr_outconns; ++i) {
> helper = csdev->pdata->out_conns[i]->dest_dev;
> if (helper && coresight_is_helper(helper))
> - coresight_disable_helper(helper);
> + coresight_disable_helper(helper, data);
> }
> }
>
> @@ -327,7 +327,7 @@ static void coresight_disable_helpers(struct coresight_device *csdev)
> void coresight_disable_source(struct coresight_device *csdev, void *data)
> {
> source_ops(csdev)->disable(csdev, data);
> - coresight_disable_helpers(csdev);
> + coresight_disable_helpers(csdev, NULL);
> }
> EXPORT_SYMBOL_GPL(coresight_disable_source);
>
> @@ -337,7 +337,8 @@ EXPORT_SYMBOL_GPL(coresight_disable_source);
> * disabled.
> */
> static void coresight_disable_path_from(struct list_head *path,
> - struct coresight_node *nd)
> + struct coresight_node *nd,
> + void *sink_data)
> {
> u32 type;
> struct coresight_device *csdev, *parent, *child;
> @@ -382,13 +383,13 @@ static void coresight_disable_path_from(struct list_head *path,
> }
>
> /* Disable all helpers adjacent along the path last */
> - coresight_disable_helpers(csdev);
> + coresight_disable_helpers(csdev, sink_data);
> }
> }
>
> -void coresight_disable_path(struct list_head *path)
> +void coresight_disable_path(struct list_head *path, void *sink_data)
> {
> - coresight_disable_path_from(path, NULL);
> + coresight_disable_path_from(path, NULL, sink_data);
> }
> EXPORT_SYMBOL_GPL(coresight_disable_path);
>
> @@ -468,10 +469,42 @@ int coresight_enable_path(struct list_head *path, enum cs_mode mode,
> out:
> return ret;
> err:
> - coresight_disable_path_from(path, nd);
> + coresight_disable_path_from(path, nd, sink_data);
> goto out;
> }
>
> +int coresight_read_traceid(struct list_head *path)
> +{
> + int trace_id, type;
> + struct coresight_device *csdev;
> + struct coresight_node *nd;
> +
> + list_for_each_entry(nd, path, link) {
> + csdev = nd->csdev;
> + type = csdev->type;
> +
> + switch(type) {
> + case CORESIGHT_DEV_TYPE_SOURCE:
> + if (source_ops(csdev)->trace_id != NULL) {
> + trace_id = source_ops(csdev)->trace_id(csdev);
> + if (trace_id > 0)
> + return trace_id;
> + }
> + break;
> + case CORESIGHT_DEV_TYPE_LINK:
> + if (link_ops(csdev)->trace_id != NULL) {
> + trace_id = link_ops(csdev)->trace_id(csdev);
> + if (trace_id > 0)
> + return trace_id;
> + }
> + break;
> + default:
> + break;
> + }
> + }
> + return -EINVAL;
> +}
> +
> struct coresight_device *coresight_get_sink(struct list_head *path)
> {
> struct coresight_device *csdev;
> diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
> index 7edd3f1d0d46..05e620529c14 100644
> --- a/drivers/hwtracing/coresight/coresight-etb10.c
> +++ b/drivers/hwtracing/coresight/coresight-etb10.c
> @@ -173,7 +173,8 @@ static int etb_enable_perf(struct coresight_device *csdev, void *data)
> pid_t pid;
> unsigned long flags;
> struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> - struct perf_output_handle *handle = data;
> + struct cs_sink_data *sink_data = (struct cs_sink_data *)data;
> + struct perf_output_handle *handle = sink_data->handle;
> struct cs_buffers *buf = etm_perf_sink_config(handle);
>
> spin_lock_irqsave(&drvdata->spinlock, flags);
> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
> index c0c60e6a1703..8b155765b959 100644
> --- a/drivers/hwtracing/coresight/coresight-etm-perf.c
> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
> @@ -452,6 +452,7 @@ static void etm_event_start(struct perf_event *event, int flags)
> struct perf_output_handle *handle = &ctxt->handle;
> struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu);
> struct list_head *path;
> + struct cs_sink_data *sink_data = NULL;
> u64 hw_id;
>
> if (!csdev)
> @@ -490,9 +491,18 @@ static void etm_event_start(struct perf_event *event, int flags)
> if (WARN_ON_ONCE(!sink))
> goto fail_end_stop;
>
> + sink_data = kzalloc(sizeof(*sink_data), GFP_KERNEL);
> + if (!sink_data)
> + goto fail_end_stop;
> +
> + sink_data->sink = sink;
> + sink_data->traceid = coresight_read_traceid(path);
> + sink_data->handle = handle;
> /* Nothing will happen without a path */
> - if (coresight_enable_path(path, CS_MODE_PERF, handle))
> + if (coresight_enable_path(path, CS_MODE_PERF, sink_data)) {
> + kfree(sink_data);
> goto fail_end_stop;
> + }
>
> /* Finally enable the tracer */
> if (source_ops(csdev)->enable(csdev, event, CS_MODE_PERF))
> @@ -511,6 +521,7 @@ static void etm_event_start(struct perf_event *event, int flags)
> perf_report_aux_output_id(event, hw_id);
> }
>
> + kfree(sink_data);
> out:
> /* Tell the perf core the event is alive */
> event->hw.state = 0;
> @@ -519,7 +530,8 @@ static void etm_event_start(struct perf_event *event, int flags)
> return;
>
> fail_disable_path:
> - coresight_disable_path(path);
> + coresight_disable_path(path, sink_data);
> + kfree(sink_data);
> fail_end_stop:
> /*
> * Check if the handle is still associated with the event,
> @@ -544,6 +556,7 @@ static void etm_event_stop(struct perf_event *event, int mode)
> struct perf_output_handle *handle = &ctxt->handle;
> struct etm_event_data *event_data;
> struct list_head *path;
> + struct cs_sink_data *sink_data = NULL;
>
> /*
> * If we still have access to the event_data via handle,
> @@ -588,6 +601,10 @@ static void etm_event_stop(struct perf_event *event, int mode)
> if (!sink)
> return;
>
> + sink_data = kzalloc(sizeof(*sink_data), GFP_KERNEL);
> + if (!sink_data)
> + return;
> +
> /* stop tracer */
> coresight_disable_source(csdev, event);
>
> @@ -601,12 +618,16 @@ static void etm_event_stop(struct perf_event *event, int mode)
> * have to do anything here.
> */
> if (handle->event && (mode & PERF_EF_UPDATE)) {
> - if (WARN_ON_ONCE(handle->event != event))
> + if (WARN_ON_ONCE(handle->event != event)) {
> + kfree(sink_data);
> return;
> + }
>
> /* update trace information */
> - if (!sink_ops(sink)->update_buffer)
> + if (!sink_ops(sink)->update_buffer) {
> + kfree(sink_data);
> return;
> + }
>
> size = sink_ops(sink)->update_buffer(sink, handle,
> event_data->snk_config);
> @@ -627,8 +648,11 @@ static void etm_event_stop(struct perf_event *event, int mode)
> WARN_ON(size);
> }
>
> + sink_data->sink = sink;
> + sink_data->traceid = coresight_read_traceid(path);
> /* Disabling the path make its elements available to other sessions */
> - coresight_disable_path(path);
> + coresight_disable_path(path, sink_data);
> + kfree(sink_data);
> }
>
> static int etm_event_add(struct perf_event *event, int mode)
> diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
> index 8b362605d242..27e973749050 100644
> --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
> @@ -696,10 +696,24 @@ static void etm_disable(struct coresight_device *csdev,
> coresight_set_mode(csdev, CS_MODE_DISABLED);
> }
>
> +static int etm_trace_id(struct coresight_device *csdev)
> +{
> + struct etm_drvdata *drvdata;
> +
> + if (csdev == NULL)
> + return -EINVAL;
> +
> + drvdata = dev_get_drvdata(csdev->dev.parent);
> +
> + return etm_read_alloc_trace_id(drvdata);
> +}
> +
> +
> static const struct coresight_ops_source etm_source_ops = {
> .cpu_id = etm_cpu_id,
> .enable = etm_enable,
> .disable = etm_disable,
> + .trace_id = etm_trace_id,
> };
>
> static const struct coresight_ops etm_cs_ops = {
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> index bf01f01964cf..8c3e9bfb9a9c 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> @@ -1024,10 +1024,23 @@ static void etm4_disable(struct coresight_device *csdev,
> coresight_set_mode(csdev, CS_MODE_DISABLED);
> }
>
> +static int etm4_trace_id(struct coresight_device *csdev)
> +{
> + struct etmv4_drvdata *drvdata;
> +
> + if (csdev == NULL)
> + return -EINVAL;
> +
> + drvdata = dev_get_drvdata(csdev->dev.parent);
> +
> + return etm4_read_alloc_trace_id(drvdata);
> +}
> +
> static const struct coresight_ops_source etm4_source_ops = {
> .cpu_id = etm4_cpu_id,
> .enable = etm4_enable,
> .disable = etm4_disable,
> + .trace_id = etm4_trace_id,
> };
>
> static const struct coresight_ops etm4_cs_ops = {
> diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
> index 61a46d3bdcc8..e2576531f796 100644
> --- a/drivers/hwtracing/coresight/coresight-priv.h
> +++ b/drivers/hwtracing/coresight/coresight-priv.h
> @@ -105,6 +105,15 @@ struct cs_buffers {
> void **data_pages;
> };
>
> +/**
> + * struct cs_sink_data - data used by coresight_enable_path/coresight_disable_path
> + */
> +struct cs_sink_data {
> + struct perf_output_handle *handle;
> + struct coresight_device *sink;
> + u32 traceid;
> +};
> +
> static inline void coresight_insert_barrier_packet(void *buf)
> {
> if (buf)
> @@ -129,9 +138,10 @@ static inline void CS_UNLOCK(void __iomem *addr)
> } while (0);
> }
>
> -void coresight_disable_path(struct list_head *path);
> +void coresight_disable_path(struct list_head *path, void *sink_data);
> int coresight_enable_path(struct list_head *path, enum cs_mode mode,
> void *sink_data);
> +int coresight_read_traceid(struct list_head *path);
> struct coresight_device *coresight_get_sink(struct list_head *path);
> struct coresight_device *coresight_get_sink_by_id(u32 id);
> struct coresight_device *
> diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
> index 117dbb484543..3817743fc0c6 100644
> --- a/drivers/hwtracing/coresight/coresight-stm.c
> +++ b/drivers/hwtracing/coresight/coresight-stm.c
> @@ -280,9 +280,22 @@ static void stm_disable(struct coresight_device *csdev,
> }
> }
>
> +static int stm_trace_id(struct coresight_device *csdev)
> +{
> + struct stm_drvdata *drvdata;
> +
> + if (csdev == NULL)
> + return -EINVAL;
> +
> + drvdata = dev_get_drvdata(csdev->dev.parent);
> +
> + return drvdata->traceid;
> +}
> +
> static const struct coresight_ops_source stm_source_ops = {
> .enable = stm_enable,
> .disable = stm_disable,
> + .trace_id = stm_trace_id,
> };
>
> static const struct coresight_ops stm_cs_ops = {
> diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c
> index 1e67cc7758d7..a95afc890587 100644
> --- a/drivers/hwtracing/coresight/coresight-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-sysfs.c
> @@ -167,6 +167,7 @@ int coresight_enable_sysfs(struct coresight_device *csdev)
> int cpu, ret = 0;
> struct coresight_device *sink;
> struct list_head *path;
> + struct cs_sink_data *sink_data;
> enum coresight_dev_subtype_source subtype;
> u32 hash;
>
> @@ -208,7 +209,14 @@ int coresight_enable_sysfs(struct coresight_device *csdev)
> goto out;
> }
>
> - ret = coresight_enable_path(path, CS_MODE_SYSFS, NULL);
> + sink_data = kzalloc(sizeof(*sink_data), GFP_KERNEL);
> + if (!sink_data) {
> + ret = -ENOMEM;
> + goto out;
> + }
> + sink_data->traceid = coresight_read_traceid(path);
> + sink_data->sink = sink;
> + ret = coresight_enable_path(path, CS_MODE_SYSFS, sink_data);
> if (ret)
> goto err_path;
>
> @@ -245,15 +253,17 @@ int coresight_enable_sysfs(struct coresight_device *csdev)
> break;
> }
>
> + kfree(sink_data);
> out:
> mutex_unlock(&coresight_mutex);
> return ret;
>
> err_source:
> - coresight_disable_path(path);
> + coresight_disable_path(path, sink_data);
>
> err_path:
> coresight_release_path(path);
> + kfree(sink_data);
> goto out;
> }
> EXPORT_SYMBOL_GPL(coresight_enable_sysfs);
> @@ -262,6 +272,7 @@ void coresight_disable_sysfs(struct coresight_device *csdev)
> {
> int cpu, ret;
> struct list_head *path = NULL;
> + struct cs_sink_data *sink_data = NULL;
> u32 hash;
>
> mutex_lock(&coresight_mutex);
> @@ -273,6 +284,10 @@ void coresight_disable_sysfs(struct coresight_device *csdev)
> if (!coresight_disable_source_sysfs(csdev, NULL))
> goto out;
>
> + sink_data = kzalloc(sizeof(*sink_data), GFP_KERNEL);
> + if (!sink_data)
> + goto out;
> +
> switch (csdev->subtype.source_subtype) {
> case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
> cpu = source_ops(csdev)->cpu_id(csdev);
> @@ -296,8 +311,11 @@ void coresight_disable_sysfs(struct coresight_device *csdev)
> break;
> }
>
> - coresight_disable_path(path);
> + sink_data->sink = coresight_find_activated_sysfs_sink(csdev);
> + sink_data->traceid = coresight_read_traceid(path);
> + coresight_disable_path(path, sink_data);
> coresight_release_path(path);
> + kfree(sink_data);
>
> out:
> mutex_unlock(&coresight_mutex);
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> index d4f641cd9de6..7dc536eba3e2 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> @@ -250,7 +250,8 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, void *data)
> pid_t pid;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> - struct perf_output_handle *handle = data;
> + struct cs_sink_data *sink_data = (struct cs_sink_data *)data;
> + struct perf_output_handle *handle = sink_data->handle;
> struct cs_buffers *buf = etm_perf_sink_config(handle);
>
> spin_lock_irqsave(&drvdata->spinlock, flags);
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> index e75428fa1592..0c24520645e2 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> @@ -1253,7 +1253,8 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
> struct etr_buf *tmc_etr_get_buffer(struct coresight_device *csdev,
> enum cs_mode mode, void *data)
> {
> - struct perf_output_handle *handle = data;
> + struct cs_sink_data *sink_data = (struct cs_sink_data *)data;
> + struct perf_output_handle *handle = sink_data->handle;
> struct etr_perf_buffer *etr_perf;
>
> switch (mode) {
> @@ -1647,7 +1648,8 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data)
> pid_t pid;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> - struct perf_output_handle *handle = data;
> + struct cs_sink_data *sink_data = (struct cs_sink_data *)data;
> + struct perf_output_handle *handle = sink_data->handle;
> struct etr_perf_buffer *etr_perf = etm_perf_sink_config(handle);
>
> spin_lock_irqsave(&drvdata->spinlock, flags);
> diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c
> index bfca103f9f84..20f0ab73159c 100644
> --- a/drivers/hwtracing/coresight/coresight-tpda.c
> +++ b/drivers/hwtracing/coresight/coresight-tpda.c
> @@ -232,9 +232,22 @@ static void tpda_disable(struct coresight_device *csdev,
> dev_dbg(drvdata->dev, "TPDA inport %d disabled\n", in->dest_port);
> }
>
> +static int tpda_trace_id(struct coresight_device *csdev)
> +{
> + struct tpda_drvdata *drvdata;
> +
> + if (csdev == NULL)
> + return -EINVAL;
> +
> + drvdata = dev_get_drvdata(csdev->dev.parent);
> +
> + return drvdata->atid;
> +}
> +
> static const struct coresight_ops_link tpda_link_ops = {
> .enable = tpda_enable,
> .disable = tpda_disable,
> + .trace_id = tpda_trace_id,
> };
>
> static const struct coresight_ops tpda_cs_ops = {
> diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
> index 96a32b213669..7f4560b067a8 100644
> --- a/drivers/hwtracing/coresight/coresight-trbe.c
> +++ b/drivers/hwtracing/coresight/coresight-trbe.c
> @@ -21,6 +21,7 @@
>
> #include "coresight-self-hosted-trace.h"
> #include "coresight-trbe.h"
> +#include "coresight-priv.h"
>
> #define PERF_IDX2OFF(idx, buf) ((idx) % ((buf)->nr_pages << PAGE_SHIFT))
>
> @@ -1012,7 +1013,8 @@ static int arm_trbe_enable(struct coresight_device *csdev, enum cs_mode mode,
> {
> struct trbe_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> struct trbe_cpudata *cpudata = dev_get_drvdata(&csdev->dev);
> - struct perf_output_handle *handle = data;
> + struct cs_sink_data *sink_data = (struct cs_sink_data *)data;
> + struct perf_output_handle *handle = sink_data->handle;
> struct trbe_buf *buf = etm_perf_sink_config(handle);
>
> WARN_ON(cpudata->cpu != smp_processor_id());
> diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c
> index f9ebf20c91e6..92d8a9fb844e 100644
> --- a/drivers/hwtracing/coresight/ultrasoc-smb.c
> +++ b/drivers/hwtracing/coresight/ultrasoc-smb.c
> @@ -217,7 +217,8 @@ static void smb_enable_sysfs(struct coresight_device *csdev)
> static int smb_enable_perf(struct coresight_device *csdev, void *data)
> {
> struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
> - struct perf_output_handle *handle = data;
> + struct cs_sink_data *sink_data = (struct cs_sink_data *)data;
> + struct perf_output_handle *handle = sink_data->handle;
> struct cs_buffers *buf = etm_perf_sink_config(handle);
> pid_t pid;
>
> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
> index f09ace92176e..fb1c225076a5 100644
> --- a/include/linux/coresight.h
> +++ b/include/linux/coresight.h
> @@ -344,6 +344,7 @@ struct coresight_ops_sink {
> * Operations available for links.
> * @enable: enables flow between iport and oport.
> * @disable: disables flow between iport and oport.
> + * @trace_id: Collect the traceid.
> */
> struct coresight_ops_link {
> int (*enable)(struct coresight_device *csdev,
> @@ -352,6 +353,7 @@ struct coresight_ops_link {
> void (*disable)(struct coresight_device *csdev,
> struct coresight_connection *in,
> struct coresight_connection *out);
> + int (*trace_id)(struct coresight_device *csdev);
> };
>
> /**
> @@ -361,6 +363,7 @@ struct coresight_ops_link {
> * is associated to.
> * @enable: enables tracing for a source.
> * @disable: disables tracing for a source.
> + * @trace_id: collect the traceid.
> */
> struct coresight_ops_source {
> int (*cpu_id)(struct coresight_device *csdev);
> @@ -368,6 +371,7 @@ struct coresight_ops_source {
> enum cs_mode mode);
> void (*disable)(struct coresight_device *csdev,
> struct perf_event *event);
> + int (*trace_id)(struct coresight_device *csdev);
> };
>
> /**
> --
> 2.34.1
>


--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK