Re: [PATCH v1 2/3] coresight: Add source filtering for multi-port output
From: Tao Zhang
Date: Thu Jul 11 2024 - 04:21:17 EST
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@xxxxxxxxxxx>
---
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