[PATCH v5 3/4] coresight: Add support for trace filtering by source
Tao Zhang
quic_taozha at quicinc.com
Fri Nov 15 01:18:34 PST 2024
On 11/13/2024 9:39 PM, Suzuki K Poulose wrote:
> On 30/10/2024 09:32, Tao Zhang wrote:
>> Some replicators have hard coded filtering of "trace" data, based on the
>> source device. This is different from the trace filtering based on
>> TraceID, available in the standard programmable replicators. e.g.,
>> Qualcomm replicators have filtering based on custom trace protocol
>> format and is not programmable.
>>
>> The source device could be connected to the replicator via intermediate
>> components (e.g., a funnel). Thus we need platform information from
>> the firmware tables to decide the source device corresponding to a
>> given output port from the replicator. Given this affects "trace
>> path building" and traversing the path back from the sink to source,
>> add the concept of "filtering by source" to the generic coresight
>> connection.
>>
>> The specified source will be marked like below in the Devicetree.
>> test-replicator {
>> ... ... ... ...
>> out-ports {
>> ... ... ... ...
>> port at 0 {
>> reg = <0>;
>> xyz: endpoint {
>> remote-endpoint = <&zyx>;
>> filter-source = <&source_1>; <-- To specify the
>> source to
>> }; be filtered out here.
>> };
>>
>> port at 1 {
>> reg = <1>;
>> abc: endpoint {
>> remote-endpoint = <&cba>;
>> filter-source = <&source_2>; <-- To specify the
>> source to
>> }; be filtered out here.
>> };
>> };
>> };
>>
>> Signed-off-by: Tao Zhang <quic_taozha at quicinc.com>
>> ---
>> drivers/hwtracing/coresight/coresight-core.c | 113 +++++++++++++++---
>> .../hwtracing/coresight/coresight-platform.c | 18 +++
>> include/linux/coresight.h | 5 +
>> 3 files changed, 117 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-core.c
>> b/drivers/hwtracing/coresight/coresight-core.c
>> index ea38ecf26fcb..0a9380350fb5 100644
>> --- a/drivers/hwtracing/coresight/coresight-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-core.c
>> @@ -75,22 +75,54 @@ struct coresight_device
>> *coresight_get_percpu_sink(int cpu)
>> }
>> EXPORT_SYMBOL_GPL(coresight_get_percpu_sink);
>> +static struct coresight_device *coresight_get_source(struct
>> list_head *path)
>> +{
>> + struct coresight_device *csdev;
>> +
>> + if (!path)
>> + return NULL;
>> +
>> + csdev = list_first_entry(path, struct coresight_node, link)->csdev;
>> + if (!coresight_is_device_source(csdev))
>> + return NULL;
>> +
>> + return csdev;
>> +}
>> +
>> +/**
>> + * coresight_blocks_source - checks whether the connection matches
>> the source
>> + * of path if connection is bound to specific source.
>> + * @src: The source device of the trace path
>> + * @conn: The connection of one outport
>> + *
>> + * Return false if the connection doesn't have a source binded or
>> source of the
>> + * path matches the source binds to connection.
>> + */
>> +static bool coresight_blocks_source(struct coresight_device *src,
>> + struct coresight_connection *conn)
>> +{
>> + return conn->filter_src_fwnode && (conn->filter_src_dev != src);
>> +}
>> +
>> static struct coresight_connection *
>> -coresight_find_out_connection(struct coresight_device *src_dev,
>> - struct coresight_device *dest_dev)
>> +coresight_find_out_connection(struct coresight_device *csdev,
>> + struct coresight_device *out_dev,
>> + struct coresight_device *trace_src)
>> {
>> int i;
>> struct coresight_connection *conn;
>> - for (i = 0; i < src_dev->pdata->nr_outconns; i++) {
>> - conn = src_dev->pdata->out_conns[i];
>> - if (conn->dest_dev == dest_dev)
>> + for (i = 0; i < csdev->pdata->nr_outconns; i++) {
>> + conn = csdev->pdata->out_conns[i];
>> + if (coresight_blocks_source(trace_src, conn))
>> + continue;
>> + if (conn->dest_dev == out_dev)
>> return conn;
>> }
>> - dev_err(&src_dev->dev,
>> - "couldn't find output connection, src_dev: %s, dest_dev: %s\n",
>> - dev_name(&src_dev->dev), dev_name(&dest_dev->dev));
>> + dev_err(&csdev->dev,
>> + "couldn't find output connection, csdev: %s, out_dev: %s\n",
>> + dev_name(&csdev->dev), dev_name(&out_dev->dev));
>> return ERR_PTR(-ENODEV);
>> }
>> @@ -251,7 +283,8 @@ static void coresight_disable_sink(struct
>> coresight_device *csdev)
>> static int coresight_enable_link(struct coresight_device *csdev,
>> struct coresight_device *parent,
>> - struct coresight_device *child)
>> + struct coresight_device *child,
>> + struct coresight_device *source)
>> {
>> int link_subtype;
>> struct coresight_connection *inconn, *outconn;
>> @@ -259,8 +292,8 @@ static int coresight_enable_link(struct
>> coresight_device *csdev,
>> if (!parent || !child)
>> return -EINVAL;
>> - inconn = coresight_find_out_connection(parent, csdev);
>> - outconn = coresight_find_out_connection(csdev, child);
>> + inconn = coresight_find_out_connection(parent, csdev, source);
>> + outconn = coresight_find_out_connection(csdev, child, source);
>> link_subtype = csdev->subtype.link_subtype;
>> if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG &&
>> IS_ERR(inconn))
>> @@ -273,15 +306,16 @@ static int coresight_enable_link(struct
>> coresight_device *csdev,
>> static void coresight_disable_link(struct coresight_device *csdev,
>> struct coresight_device *parent,
>> - struct coresight_device *child)
>> + struct coresight_device *child,
>> + struct coresight_device *source)
>> {
>> struct coresight_connection *inconn, *outconn;
>> if (!parent || !child)
>> return;
>> - inconn = coresight_find_out_connection(parent, csdev);
>> - outconn = coresight_find_out_connection(csdev, child);
>> + inconn = coresight_find_out_connection(parent, csdev, source);
>> + outconn = coresight_find_out_connection(csdev, child, source);
>> link_ops(csdev)->disable(csdev, inconn, outconn);
>> }
>> @@ -375,7 +409,8 @@ static void coresight_disable_path_from(struct
>> list_head *path,
>> case CORESIGHT_DEV_TYPE_LINK:
>> parent = list_prev_entry(nd, link)->csdev;
>> child = list_next_entry(nd, link)->csdev;
>> - coresight_disable_link(csdev, parent, child);
>> + coresight_disable_link(csdev, parent, child,
>> + coresight_get_source(path));
>> break;
>> default:
>> break;
>> @@ -418,7 +453,9 @@ int coresight_enable_path(struct list_head *path,
>> enum cs_mode mode,
>> u32 type;
>> struct coresight_node *nd;
>> struct coresight_device *csdev, *parent, *child;
>> + struct coresight_device *source;
>> + source = coresight_get_source(path);
>> list_for_each_entry_reverse(nd, path, link) {
>> csdev = nd->csdev;
>> type = csdev->type;
>> @@ -456,7 +493,7 @@ int coresight_enable_path(struct list_head *path,
>> enum cs_mode mode,
>> case CORESIGHT_DEV_TYPE_LINK:
>> parent = list_prev_entry(nd, link)->csdev;
>> child = list_next_entry(nd, link)->csdev;
>> - ret = coresight_enable_link(csdev, parent, child);
>> + ret = coresight_enable_link(csdev, parent, child, source);
>> if (ret)
>> goto err;
>> break;
>> @@ -619,6 +656,7 @@ static void coresight_drop_device(struct
>> coresight_device *csdev)
>> /**
>> * _coresight_build_path - recursively build a path from a @csdev
>> to a sink.
>> * @csdev: The device to start from.
>> + * @source: The trace source device of the path.
>> * @sink: The final sink we want in this path.
>> * @path: The list to add devices to.
>> *
>> @@ -628,6 +666,7 @@ static void coresight_drop_device(struct
>> coresight_device *csdev)
>> * the source is the first device and the sink the last one.
>> */
>> static int _coresight_build_path(struct coresight_device *csdev,
>> + struct coresight_device *source,
>> struct coresight_device *sink,
>> struct list_head *path)
>> {
>> @@ -641,7 +680,7 @@ static int _coresight_build_path(struct
>> coresight_device *csdev,
>> if (coresight_is_percpu_source(csdev) &&
>> coresight_is_percpu_sink(sink) &&
>> sink == per_cpu(csdev_sink,
>> source_ops(csdev)->cpu_id(csdev))) {
>> - if (_coresight_build_path(sink, sink, path) == 0) {
>> + if (_coresight_build_path(sink, source, sink, path) == 0) {
>> found = true;
>> goto out;
>> }
>> @@ -652,8 +691,12 @@ static int _coresight_build_path(struct
>> coresight_device *csdev,
>> struct coresight_device *child_dev;
>> child_dev = csdev->pdata->out_conns[i]->dest_dev;
>> +
>> + if (coresight_blocks_source(source,
>> csdev->pdata->out_conns[i]))
>> + continue;
>> +
>> if (child_dev &&
>> - _coresight_build_path(child_dev, sink, path) == 0) {
>> + _coresight_build_path(child_dev, source, sink, path) ==
>> 0) {
>> found = true;
>> break;
>> }
>> @@ -698,7 +741,7 @@ struct list_head *coresight_build_path(struct
>> coresight_device *source,
>> INIT_LIST_HEAD(path);
>> - rc = _coresight_build_path(source, sink, path);
>> + rc = _coresight_build_path(source, source, sink, path);
>> if (rc) {
>> kfree(path);
>> return ERR_PTR(rc);
>> @@ -927,6 +970,16 @@ static int coresight_orphan_match(struct device
>> *dev, void *data)
>> for (i = 0; i < src_csdev->pdata->nr_outconns; i++) {
>> conn = src_csdev->pdata->out_conns[i];
>> + /* Fix filter source device before skip the port */
>> + if (conn->filter_src_fwnode && !conn->filter_src_dev) {
>> + if (dst_csdev &&
>> + (conn->filter_src_fwnode == dst_csdev->dev.fwnode) &&
>> + !WARN_ON_ONCE(!coresight_is_device_source(dst_csdev)))
>> + conn->filter_src_dev = dst_csdev;
>> + else
>> + still_orphan = true;
>> + }
>> +
>> /* Skip the port if it's already connected. */
>> if (conn->dest_dev)
>> continue;
>> @@ -977,18 +1030,40 @@ static int coresight_fixup_orphan_conns(struct
>> coresight_device *csdev)
>> csdev, coresight_orphan_match);
>> }
>> +static int coresight_clear_filter_source(struct device *dev, void
>> *data)
>> +{
>> + int i;
>> + struct coresight_device *source = data;
>> + struct coresight_device *csdev = to_coresight_device(dev);
>> +
>> + for (i = 0; i < csdev->pdata->nr_outconns; ++i) {
>> + if (csdev->pdata->out_conns[i]->filter_src_dev == source)
>> + csdev->pdata->out_conns[i]->filter_src_dev = NULL;
>> + }
>> + return 0;
>> +}
>> +
>> /* coresight_remove_conns - Remove other device's references to
>> this device */
>> static void coresight_remove_conns(struct coresight_device *csdev)
>> {
>> int i, j;
>> struct coresight_connection *conn;
>> + if (coresight_is_device_source(csdev))
>> + bus_for_each_dev(&coresight_bustype, NULL, csdev,
>> + coresight_clear_filter_source);
>> +
>> /*
>> * Remove the input connection references from the destination
>> device
>> * for each output connection.
>> */
>> for (i = 0; i < csdev->pdata->nr_outconns; i++) {
>> conn = csdev->pdata->out_conns[i];
>> + if (conn->filter_src_fwnode) {
>> + conn->filter_src_dev = NULL;
>> + fwnode_handle_put(conn->filter_src_fwnode);
>> + }
>> +
>> if (!conn->dest_dev)
>> continue;
>> diff --git a/drivers/hwtracing/coresight/coresight-platform.c
>> b/drivers/hwtracing/coresight/coresight-platform.c
>> index 64e171eaad82..d5532caa9e92 100644
>> --- a/drivers/hwtracing/coresight/coresight-platform.c
>> +++ b/drivers/hwtracing/coresight/coresight-platform.c
>> @@ -243,6 +243,24 @@ static int of_coresight_parse_endpoint(struct
>> device *dev,
>> conn.dest_fwnode = fwnode_handle_get(rdev_fwnode);
>> conn.dest_port = rendpoint.port;
>> + /*
>> + * Get the firmware node of the filter source through the
>> + * reference. This could be used to filter the source in
>> + * building path.
>> + */
>> + conn.filter_src_fwnode =
>> + fwnode_find_reference(&ep->fwnode, "filter-source", 0);
>> + if (IS_ERR(conn.filter_src_fwnode)) {
>> + conn.filter_src_fwnode = NULL;
>> + } else {
>> + conn.filter_src_dev =
>> + coresight_find_csdev_by_fwnode(conn.filter_src_fwnode);
>> + if (conn.filter_src_dev &&
>> + !coresight_is_device_source(conn.filter_src_dev))
>> + dev_warn(&conn.filter_src_dev->dev,
>> + "Filter source is not a source device\n");
>
> Do we need to reset the conn.filter_src_fwnode ? Otherwise, we can
> warn from other places too.
Agree, we need to reset conn.filter_src_fwnode and conn.filter_src_dev
here if it is not a SOURCE
type device.
I will update the following code to the next patch series. Could you
help check if it is fine to you?
+ if (conn.filter_src_dev &&
+ !coresight_is_device_source(conn.filter_src_dev)) {
+ dev_warn(&conn.filter_src_dev->dev,
+ "Filter source is not a source device\n");
+ conn.filter_src_dev = NULL；
+ conn.filter_src_dev = NULL；
+ }
Best,
Tao
>
> Suzuki
>
>> + }
>> +
>> new_conn = coresight_add_out_conn(dev, pdata, &conn);
>> if (IS_ERR_VALUE(new_conn)) {
>> fwnode_handle_put(conn.dest_fwnode);
>> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
>> index 9311df8538fc..f372c01ae2fc 100644
>> --- a/include/linux/coresight.h
>> +++ b/include/linux/coresight.h
>> @@ -172,6 +172,9 @@ struct coresight_desc {
>> * @dest_dev: a @coresight_device representation of the component
>> connected to @src_port. NULL until the device is created
>> * @link: Representation of the connection as a sysfs link.
>> + * @filter_src_fwnode: filter source component's fwnode handle.
>> + * @filter_src_dev: a @coresight_device representation of the
>> component that
>> + needs to be filtered.
>> *
>> * The full connection structure looks like this, where in_conns store
>> * references to same connection as the source device's out_conns.
>> @@ -200,6 +203,8 @@ struct coresight_connection {
>> struct coresight_device *dest_dev;
>> struct coresight_sysfs_link *link;
>> struct coresight_device *src_dev;
>> + struct fwnode_handle *filter_src_fwnode;
>> + struct coresight_device *filter_src_dev;
>> atomic_t src_refcnt;
>> atomic_t dest_refcnt;
>> };
>
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