Re: [PATCH v4 07/13] coresight: Store pointers to connections rather than an array of them

From: Suzuki K Poulose
Date: Tue Apr 04 2023 - 10:18:41 EST


On 04/04/2023 14:53, James Clark wrote:
This will allow the same connection object to be referenced via the
input connection list in a later commit rather than duplicating them.

Signed-off-by: James Clark <james.clark@xxxxxxx>
---
drivers/hwtracing/coresight/coresight-core.c | 47 ++++++++++---------
.../hwtracing/coresight/coresight-platform.c | 10 ++--
drivers/hwtracing/coresight/coresight-priv.h | 1 +
.../hwtracing/coresight/coresight-tmc-etr.c | 2 +-
include/linux/coresight.h | 5 +-
5 files changed, 35 insertions(+), 30 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 91274e7e6944..0b738960973b 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -119,7 +119,7 @@ static int coresight_find_link_inport(struct coresight_device *csdev,
struct coresight_connection *conn;
for (i = 0; i < parent->pdata->nr_outconns; i++) {
- conn = &parent->pdata->out_conns[i];
+ conn = parent->pdata->out_conns[i];
if (conn->dest_dev == csdev)
return conn->dest_port;
}
@@ -137,7 +137,7 @@ static int coresight_find_link_outport(struct coresight_device *csdev,
struct coresight_connection *conn;
for (i = 0; i < csdev->pdata->nr_outconns; i++) {
- conn = &csdev->pdata->out_conns[i];
+ conn = csdev->pdata->out_conns[i];
if (conn->dest_dev == child)
return conn->src_port;
}
@@ -606,7 +606,7 @@ coresight_find_enabled_sink(struct coresight_device *csdev)
for (i = 0; i < csdev->pdata->nr_outconns; i++) {
struct coresight_device *child_dev;
- child_dev = csdev->pdata->out_conns[i].dest_dev;
+ child_dev = csdev->pdata->out_conns[i]->dest_dev;
if (child_dev)
sink = coresight_find_enabled_sink(child_dev);
if (sink)
@@ -722,7 +722,7 @@ static int coresight_grab_device(struct coresight_device *csdev)
for (i = 0; i < csdev->pdata->nr_outconns; i++) {
struct coresight_device *child;
- child = csdev->pdata->out_conns[i].dest_dev;
+ child = csdev->pdata->out_conns[i]->dest_dev;
if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
if (!coresight_get_ref(child))
goto err;
@@ -733,7 +733,7 @@ static int coresight_grab_device(struct coresight_device *csdev)
for (i--; i >= 0; i--) {
struct coresight_device *child;
- child = csdev->pdata->out_conns[i].dest_dev;
+ child = csdev->pdata->out_conns[i]->dest_dev;
if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
coresight_put_ref(child);
}
@@ -752,7 +752,7 @@ static void coresight_drop_device(struct coresight_device *csdev)
for (i = 0; i < csdev->pdata->nr_outconns; i++) {
struct coresight_device *child;
- child = csdev->pdata->out_conns[i].dest_dev;
+ child = csdev->pdata->out_conns[i]->dest_dev;
if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
coresight_put_ref(child);
}
@@ -794,7 +794,7 @@ static int _coresight_build_path(struct coresight_device *csdev,
for (i = 0; i < csdev->pdata->nr_outconns; i++) {
struct coresight_device *child_dev;
- child_dev = csdev->pdata->out_conns[i].dest_dev;
+ child_dev = csdev->pdata->out_conns[i]->dest_dev;
if (child_dev &&
_coresight_build_path(child_dev, sink, path) == 0) {
found = true;
@@ -964,7 +964,7 @@ coresight_find_sink(struct coresight_device *csdev, int *depth)
struct coresight_device *child_dev, *sink = NULL;
int child_depth = curr_depth;
- child_dev = csdev->pdata->out_conns[i].dest_dev;
+ child_dev = csdev->pdata->out_conns[i]->dest_dev;
if (child_dev)
sink = coresight_find_sink(child_dev, &child_depth);
@@ -1334,7 +1334,7 @@ static int coresight_orphan_match(struct device *dev, void *data)
* an orphan connection whose name matches @csdev, link it.
*/
for (i = 0; i < i_csdev->pdata->nr_outconns; i++) {
- conn = &i_csdev->pdata->out_conns[i];
+ conn = i_csdev->pdata->out_conns[i];
/* We have found at least one orphan connection */
if (conn->dest_dev == NULL) {
@@ -1372,7 +1372,7 @@ static int coresight_fixup_device_conns(struct coresight_device *csdev)
int i, ret = 0;
for (i = 0; i < csdev->pdata->nr_outconns; i++) {
- struct coresight_connection *conn = &csdev->pdata->out_conns[i];
+ struct coresight_connection *conn = csdev->pdata->out_conns[i];
conn->dest_dev =
coresight_find_csdev_by_fwnode(conn->dest_fwnode);
@@ -1406,15 +1406,12 @@ static int coresight_remove_match(struct device *dev, void *data)
* a connection whose name matches @csdev, remove it.
*/
for (i = 0; i < iterator->pdata->nr_outconns; i++) {
- conn = &iterator->pdata->out_conns[i];
+ conn = iterator->pdata->out_conns[i];
- if (conn->dest_dev == NULL)
- continue;
-
- if (csdev->dev.fwnode == conn->dest_fwnode) {
+ /* Child_dev being set signifies that the links were made */
+ if (csdev->dev.fwnode == conn->dest_fwnode && conn->dest_dev) {
iterator->orphan = true;
coresight_remove_links(iterator, conn);
-
conn->dest_dev = NULL;
/* No need to continue */
break;
@@ -1534,22 +1531,26 @@ void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset)
* to the output port of this device.
*/
void coresight_release_platform_data(struct coresight_device *csdev,
+ struct device *dev,
struct coresight_platform_data *pdata)
{
int i;
- struct coresight_connection *conns = pdata->out_conns;
+ struct coresight_connection **conns = pdata->out_conns;
for (i = 0; i < pdata->nr_outconns; i++) {
/* If we have made the links, remove them now */
- if (csdev && conns[i].dest_dev)
- coresight_remove_links(csdev, &conns[i]);
+ if (csdev && conns[i]->dest_dev)
+ coresight_remove_links(csdev, conns[i]);
/*
* Drop the refcount and clear the handle as this device
* is going away
*/
- fwnode_handle_put(conns[i].dest_fwnode);
- conns[i].dest_fwnode = NULL;
+ fwnode_handle_put(conns[i]->dest_fwnode);
+ conns[i]->dest_fwnode = NULL;
+ devm_kfree(dev, conns[i]);
}
+ devm_kfree(dev, pdata->out_conns);
+ devm_kfree(dev, pdata);
if (csdev)
coresight_remove_conns_sysfs_group(csdev);
}
@@ -1666,7 +1667,7 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)
err_out:
/* Cleanup the connection information */
- coresight_release_platform_data(NULL, desc->pdata);
+ coresight_release_platform_data(NULL, desc->dev, desc->pdata);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(coresight_register);
@@ -1679,7 +1680,7 @@ void coresight_unregister(struct coresight_device *csdev)
cti_assoc_ops->remove(csdev);
coresight_remove_conns(csdev);
coresight_clear_default_sink(csdev);
- coresight_release_platform_data(csdev, csdev->pdata);
+ coresight_release_platform_data(csdev, csdev->dev.parent, csdev->pdata);
device_unregister(&csdev->dev);
}
EXPORT_SYMBOL_GPL(coresight_unregister);
diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
index 8c2029336161..017ea5762988 100644
--- a/drivers/hwtracing/coresight/coresight-platform.c
+++ b/drivers/hwtracing/coresight/coresight-platform.c
@@ -37,7 +37,7 @@ coresight_add_out_conn(struct device *dev,
* Warn on any existing duplicate output port.
*/
for (i = 0; i < pdata->nr_outconns; ++i) {
- conn = &pdata->out_conns[i];
+ conn = pdata->out_conns[i];
/* Output == -1 means ignore the port for example for helpers */
if (conn->src_port != -1 &&
conn->src_port == new_conn->src_port) {
@@ -54,8 +54,10 @@ coresight_add_out_conn(struct device *dev,
if (!pdata->out_conns)
return ERR_PTR(-ENOMEM);
- pdata->out_conns[pdata->nr_outconns - 1] = *new_conn;
- return &pdata->out_conns[pdata->nr_outconns - 1];
+ pdata->out_conns[pdata->nr_outconns - 1] = devm_kmalloc(
+ dev, sizeof(struct coresight_connection), GFP_KERNEL);

Please check the error in allocation. While at it, please use a variable
to simplify the code reading.

Otherwise looks good to me

Suzuki