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Message-ID: <89b90002-fcb8-44c3-bc03-819941161c5d@quicinc.com>
Date: Thu, 11 Jul 2024 16:20:12 +0800
From: Tao Zhang <quic_taozha@...cinc.com>
To: Suzuki K Poulose <suzuki.poulose@....com>,
Mathieu Poirier
<mathieu.poirier@...aro.org>,
Alexander Shishkin
<alexander.shishkin@...ux.intel.com>,
Mike Leach <mike.leach@...aro.org>, "Rob Herring" <robh+dt@...nel.org>,
Krzysztof Kozlowski
<krzysztof.kozlowski+dt@...aro.org>,
James Clark <james.clark@....com>, <james.clark@...aro.org>
CC: Jinlong Mao <quic_jinlmao@...cinc.com>, Leo Yan <leo.yan@...aro.org>,
<coresight@...ts.linaro.org>, <linux-arm-kernel@...ts.infradead.org>,
<linux-kernel@...r.kernel.org>, <devicetree@...r.kernel.org>,
Tingwei Zhang
<quic_tingweiz@...cinc.com>,
Yuanfang Zhang <quic_yuanfang@...cinc.com>,
Trilok Soni <quic_tsoni@...cinc.com>,
Song Chai <quic_songchai@...cinc.com>, <linux-arm-msm@...r.kernel.org>,
Jie Gan <quic_jiegan@...cinc.com>
Subject: Re: [PATCH v1 2/3] coresight: Add source filtering for multi-port
output
On 7/9/2024 9:42 PM, Suzuki K Poulose wrote:
> On 05/07/2024 09:51, Tao Zhang wrote:
>> In order to enable the output ports of multi-port output devices,
>> such as static replicator, to correspond to designated sources,
>> a mechanism for filtering data sources is introduced for the
>> output ports.
>>
>> The specified source will be marked like below in the Devicetree.
>> test-replicator {
>> ... ... ... ...
>> out-ports {
>> ... ... ... ...
>> port@0 {
>> reg = <0>;
>> xxx: endpoint {
>> remote-endpoint = <&xxx>;
>> filter_src = <&xxx>; <-- To specify the source to
>> }; be filtered out here.
>> };
>>
>> port@1 {
>> reg = <1>;
>> yyy: endpoint {
>> remote-endpoint = <&yyy>;
>> filter_src = <&yyy>; <-- To specify the source to
>> }; be filtered out here.
>> };
>> };
>> };
>>
>> Then driver will find the expected source marked in the Devicetree, and
>> save it to the coresight path. When the function needs to filter the
>> source, it could obtain it from coresight path parameter. Finally,
>> the output port knows which source it corresponds to, and it also knows
>> which input port it corresponds to.
>>
>> Signed-off-by: Tao Zhang <quic_taozha@...cinc.com>
>> ---
>> drivers/hwtracing/coresight/coresight-core.c | 89 ++++++++++++++++---
>> .../hwtracing/coresight/coresight-platform.c | 13 +++
>> include/linux/coresight.h | 5 ++
>> 3 files changed, 94 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-core.c
>> b/drivers/hwtracing/coresight/coresight-core.c
>> index 5dde597403b3..1c58b64f0031 100644
>> --- a/drivers/hwtracing/coresight/coresight-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-core.c
>> @@ -113,15 +113,62 @@ 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 (csdev->type != CORESIGHT_DEV_TYPE_SOURCE)
>> + return NULL;
>> +
>> + return csdev;
>> +}
>> +
>> +/**
>> + * coresight_source_filter - checks whether the connection matches
>> the source
>> + * of path if connection is binded to specific source.
>> + * @path: The list of devices
>> + * @conn: The connection of one outport
>> + *
>> + * Return zero if the connection doesn't have a source binded or
>> source of the
>> + * path matches the source binds to connection.
>> + */
>> +static int coresight_source_filter(struct list_head *path,
>
> Instead of path, you may need to switch to "source" device. See below.
Got it. I will update in the next patch series.
>
>> + struct coresight_connection *conn)
>> +{
>> + int ret = 0;
>> + struct coresight_device *source = NULL;
>> +
>> + if (!conn->filter_src_dev)
>> + return ret;
>> +
>> + source = coresight_get_source(path);
>> + if (!source)
>> + return ret;
>> +
>> + if (conn->filter_src_dev == source)
>> + ret = 0;
>> + else
>> + ret = -1;
>> +
>> + return ret;
>> +}
>> +
>> static struct coresight_connection *
>> coresight_find_out_connection(struct coresight_device *src_dev,
>> - struct coresight_device *dest_dev)
>> + struct coresight_device *dest_dev,
>> + struct list_head *path)
>> {
>> int i;
>> struct coresight_connection *conn;
>> for (i = 0; i < src_dev->pdata->nr_outconns; i++) {
>> conn = src_dev->pdata->out_conns[i];
>> + if (coresight_source_filter(path, conn))
>> + continue;
>> if (conn->dest_dev == dest_dev)
>> return conn;
>> }
>> @@ -312,7 +359,8 @@ 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 list_head *path)
>> {
>> int ret = 0;
>> int link_subtype;
>> @@ -321,8 +369,8 @@ 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, path);
>> + outconn = coresight_find_out_connection(csdev, child, path);
>> link_subtype = csdev->subtype.link_subtype;
>> if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG &&
>> IS_ERR(inconn))
>> @@ -341,7 +389,8 @@ 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 list_head *path)
>> {
>> int i;
>> int link_subtype;
>> @@ -350,8 +399,8 @@ static void coresight_disable_link(struct
>> coresight_device *csdev,
>> 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, path);
>> + outconn = coresight_find_out_connection(csdev, child, path);
>> link_subtype = csdev->subtype.link_subtype;
>> if (link_ops(csdev)->disable) {
>> @@ -507,7 +556,7 @@ 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, path);
>> break;
>
> Disable path from could be called with a "partial path" with the
> "source" stripped off. e.g, if the enabling of the components failed
> mid-point in the path. So, source_from_path() above is WRONG csdev.
> Instead you should make sure we pass the "source", which must be
> available with the caller.
I will update in the next patch series.
>
>
>> default:
>> break;
>> @@ -588,7 +637,7 @@ 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, path);
>> if (ret)
>> goto err;
>> break;
>> @@ -802,7 +851,8 @@ static void coresight_drop_device(struct
>> coresight_device *csdev)
>> */
>> static int _coresight_build_path(struct coresight_device *csdev,
>> struct coresight_device *sink,
>> - struct list_head *path)
>> + struct list_head *path,
>> + struct coresight_device *trace_source)
>> {
>> int i, ret;
>> bool found = false;
>> @@ -814,7 +864,7 @@ 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, sink, path, trace_source) ==
>> 0) {
>> found = true;
>> goto out;
>> }
>> @@ -825,8 +875,13 @@ static int _coresight_build_path(struct
>> coresight_device *csdev,
>> struct coresight_device *child_dev;
>> child_dev = csdev->pdata->out_conns[i]->dest_dev;
>> +
>> + if (csdev->pdata->out_conns[i]->filter_src_dev
>> + && (csdev->pdata->out_conns[i]->filter_src_dev !=
>> trace_source))
>> + continue;
>> +
>> if (child_dev &&
>> - _coresight_build_path(child_dev, sink, path) == 0) {
>> + _coresight_build_path(child_dev, sink, path,
>> trace_source) == 0) {
>> found = true;
>> break;
>> }
>> @@ -871,7 +926,7 @@ 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, sink, path, source);
>> if (rc) {
>> kfree(path);
>> return ERR_PTR(rc);
>> @@ -1395,6 +1450,9 @@ static int coresight_orphan_match(struct device
>> *dev, void *data)
>> /* This component still has an orphan */
>> still_orphan = true;
>> }
>> + if ((conn->filter_src_fwnode) && dst_csdev
>> + && (conn->filter_src_fwnode == dst_csdev->dev.fwnode))
>> + conn->filter_src_dev = dst_csdev;
>> }
>> src_csdev->orphan = still_orphan;
>> @@ -1424,6 +1482,11 @@ static void coresight_remove_conns(struct
>> coresight_device *csdev)
>> */
>> for (i = 0; i < csdev->pdata->nr_outconns; i++) {
>> conn = csdev->pdata->out_conns[i];
>> + if (conn->filter_src_dev) {
>> + conn->filter_src_dev = NULL;
>> + conn->filter_src_fwnode = NULL;
>> + }
>> +
>
> Similarly we should reset the "filter_src_dev" if the "src" csdev is
> being removed. You may need a new function for that, which scans
> through all devices and looks for a conn->filter_src_dev == csdev.
> Something like:
I will update in the next patch series.
>
>
>
>> if (!conn->dest_dev)
>> continue;
>> diff --git a/drivers/hwtracing/coresight/coresight-platform.c
>> b/drivers/hwtracing/coresight/coresight-platform.c
>> index 9d550f5697fa..a9f5b0700310 100644
>> --- a/drivers/hwtracing/coresight/coresight-platform.c
>> +++ b/drivers/hwtracing/coresight/coresight-platform.c
>> @@ -243,6 +243,19 @@ 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_src", 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);
>
> We should warn, if the filter_src_dev is of not the type DEV_TYPE_SOURCE.
I will update in the next patch series.
Best,
Tao
>
>> +
>> 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 e8b6e388218c..0a7ec0978605 100644
>> --- a/include/linux/coresight.h
>> +++ b/include/linux/coresight.h
>> @@ -171,6 +171,9 @@ 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.
>> @@ -199,6 +202,8 @@ 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;
>> };
>
> Suzuki
>
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