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Message-ID: <f2221c21-b891-413f-8adb-e76921da1fb1@arm.com>
Date: Fri, 15 Nov 2024 09:40:45 +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 15/11/2024 09:18, Tao Zhang wrote:
>
> 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@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.
>
> 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?
This looks good.
>
> + 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");
minor nit: It would be good to indicate which device has this
"filtering". i.e,
dev_warn(dev, "Filter source is not a trace source : %s\n",
dev_name(&conn.filter_src_dev->dev));
> + conn.filter_src_dev = NULL；
> + conn.filter_src_dev = NULL；
Duplicated line ^
Suzuki
> + }
>
> 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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