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Message-ID: <c39a844e-d0a8-46ac-ab52-530dae741751@arm.com>
Date: Wed, 13 Nov 2024 13:39:44 +0000
From: Suzuki K Poulose <suzuki.poulose@....com>
To: Tao Zhang <quic_taozha@...cinc.com>, Mike Leach <mike.leach@...aro.org>,
James Clark <james.clark@....com>, Rob Herring <robh@...nel.org>,
Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley
<conor+dt@...nel.org>, Mathieu Poirier <mathieu.poirier@...aro.org>,
Leo Yan <leo.yan@...ux.dev>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>
Cc: coresight@...ts.linaro.org, linux-arm-kernel@...ts.infradead.org,
linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
linux-arm-msm@...r.kernel.org
Subject: Re: [PATCH v5 3/4] coresight: Add support for trace filtering by
source
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@0 {
> reg = <0>;
> xyz: endpoint {
> remote-endpoint = <&zyx>;
> filter-source = <&source_1>; <-- To specify the source to
> }; be filtered out here.
> };
>
> port@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@...cinc.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.
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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