[PATCH 2/4] coresight: Add support for multiple output ports on the funnel
Suzuki K Poulose
suzuki.poulose at arm.com
Thu Mar 21 09:41:54 PDT 2024
On 21/03/2024 08:32, Tao Zhang wrote:
> Funnel devices are now capable of supporting multiple-inputs and
> multiple-outputs configuration with in built hardware filtering
> for TPDM devices. Add software support to this function. Output
> port is selected according to the source in the trace path.
>
> The source of the input port on funnels will be marked in the
> device tree.
> e.g.
> tpdm at xxxxxxx {
> ... ... ... ...
> };
>
> funnel_XXX: funnel at xxxxxxx {
> ... ... ... ...
> out-ports {
> ... ... ... ...
> port at x {
> ... ... ... ...
> label = "xxxxxxx.tpdm"; <-- To label the source
> }; corresponding to the output
> ... ... ... ... connection "port at x". And this
> }; is a hardware static connections.
> ... ... ... ... Here needs to refer to hardware
> }; design.
>
> Then driver will parse the source label marked in the device tree, and
> save it to the coresight path. When the function needs to know the
> source label, 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.
Why do we need labels ? We have connection information for all devices
(both in and out), so, why do we need this label to find a device ?
And also, I thought TPDM is a source device, why does a funnel output
port link to a source ?
Are these funnels programmable ? Or, are they static ? If they are
static, do these need to be described in the DT ? If they are simply
acting as a "LINK" (or HWFIFO ?)
Suzuki
>
> Signed-off-by: Tao Zhang <quic_taozha at quicinc.com>
> ---
> drivers/hwtracing/coresight/coresight-core.c | 81 ++++++++++++++++---
> .../hwtracing/coresight/coresight-platform.c | 5 ++
> include/linux/coresight.h | 2 +
> 3 files changed, 75 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
> index 5dde597403b3..b1b5e6d9ec7a 100644
> --- a/drivers/hwtracing/coresight/coresight-core.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -113,15 +113,63 @@ 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,
> + struct coresight_connection *conn)
> +{
> + int ret = 0;
> + struct coresight_device *source = NULL;
> +
> + if (conn->source_label == NULL)
> + return ret;
> +
> + source = coresight_get_source(path);
> + if (source == NULL)
> + return ret;
> +
> + if (strstr(kobject_get_path(&source->dev.kobj, GFP_KERNEL),
> + conn->source_label))
> + 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 +360,8 @@ 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 +370,8 @@ 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 +390,8 @@ 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 +400,8 @@ 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 +557,7 @@ 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;
> default:
> break;
> @@ -588,7 +638,7 @@ 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 +852,8 @@ 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 *source)
> {
> int i, ret;
> bool found = false;
> @@ -814,7 +865,7 @@ 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, source) == 0) {
> found = true;
> goto out;
> }
> @@ -825,8 +876,12 @@ static int _coresight_build_path(struct coresight_device *csdev,
> struct coresight_device *child_dev;
>
> child_dev = csdev->pdata->out_conns[i]->dest_dev;
> + if (csdev->pdata->out_conns[i]->source_label &&
> + !strstr(kobject_get_path(&source->dev.kobj, GFP_KERNEL),
> + csdev->pdata->out_conns[i]->source_label))
> + continue;
> if (child_dev &&
> - _coresight_build_path(child_dev, sink, path) == 0) {
> + _coresight_build_path(child_dev, sink, path, 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);
> diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
> index 9d550f5697fa..f553fb20966d 100644
> --- a/drivers/hwtracing/coresight/coresight-platform.c
> +++ b/drivers/hwtracing/coresight/coresight-platform.c
> @@ -205,6 +205,7 @@ static int of_coresight_parse_endpoint(struct device *dev,
> struct fwnode_handle *rdev_fwnode;
> struct coresight_connection conn = {};
> struct coresight_connection *new_conn;
> + const char *label;
>
> do {
> /* Parse the local port details */
> @@ -243,6 +244,10 @@ static int of_coresight_parse_endpoint(struct device *dev,
> conn.dest_fwnode = fwnode_handle_get(rdev_fwnode);
> conn.dest_port = rendpoint.port;
>
> + conn.source_label = NULL;
> + if (!of_property_read_string(ep, "label", &label))
> + conn.source_label = label;
> +
> 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..a9c06ef9bbb2 100644
> --- a/include/linux/coresight.h
> +++ b/include/linux/coresight.h
> @@ -167,6 +167,7 @@ struct coresight_desc {
> * struct coresight_connection - representation of a single connection
> * @src_port: a connection's output port number.
> * @dest_port: destination's input port number @src_port is connected to.
> + * @source_label: source component's label.
> * @dest_fwnode: destination component's fwnode handle.
> * @dest_dev: a @coresight_device representation of the component
> connected to @src_port. NULL until the device is created
> @@ -195,6 +196,7 @@ struct coresight_desc {
> struct coresight_connection {
> int src_port;
> int dest_port;
> + const char *source_label;
> struct fwnode_handle *dest_fwnode;
> struct coresight_device *dest_dev;
> struct coresight_sysfs_link *link;
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