This series introduces interconnect debugfs files that support voting
for any path the framework supports.
We've historically relied on an out-of-tree module for this, which used
the old icc_get() that was recently removed in [0]. The old icc_get()
took integer endpoint IDs, which made identifying paths in our old
implementation non-intuitive. The logical node names typically don't
change much chip-to-chip, but the raw integer IDs do. Take this
opportunity to introduce an icc_get() that uses string names instead,
which allows for a more intuitive and generic debugfs interface.
We rely on this support for debug, test, and verification. Hopefully
it'll be useful for other vendors as well.
[0] commit 7dcdad6f32c9 ("interconnect: drop unused icc_get() interface")
Changes in v3:
- Use GFP_ATOMIC when allocating with the rcu lock held.
Changes in v2:
- Make icc_get() an internal interface.
- RCU-protect src_node and dst_node.
- Replace PLATFORM_DEVID_AUTO with PLATFORM_DEVID_NONE.
- Remove unnecessary #include.
- Add debugfs client documentation.
Mike Tipton (3):
debugfs: Add write support to debugfs_create_str()
interconnect: Reintroduce icc_get()
interconnect: Add debugfs test client
Documentation/driver-api/interconnect.rst | 25 ++++
drivers/interconnect/Makefile | 2 +-
drivers/interconnect/core.c | 66 +++++++++
drivers/interconnect/debugfs-client.c | 168 ++++++++++++++++++++++
drivers/interconnect/internal.h | 3 +
fs/debugfs/file.c | 48 ++++++-
6 files changed, 309 insertions(+), 3 deletions(-)
create mode 100644 drivers/interconnect/debugfs-client.c
--
2.17.1
The original icc_get() that took integer node IDs was removed due to
lack of users. Reintroduce a new version that takes string node names,
which is needed for the debugfs client.
Signed-off-by: Mike Tipton <[email protected]>
---
drivers/interconnect/core.c | 63 +++++++++++++++++++++++++++++++++
drivers/interconnect/internal.h | 2 ++
2 files changed, 65 insertions(+)
diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 5fac448c28fd..fc1461dfc61b 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -147,6 +147,21 @@ static struct icc_node *node_find(const int id)
return idr_find(&icc_idr, id);
}
+static struct icc_node *node_find_by_name(const char *name)
+{
+ struct icc_provider *provider;
+ struct icc_node *n;
+
+ list_for_each_entry(provider, &icc_providers, provider_list) {
+ list_for_each_entry(n, &provider->nodes, node_list) {
+ if (!strcmp(n->name, name))
+ return n;
+ }
+ }
+
+ return NULL;
+}
+
static struct icc_path *path_init(struct device *dev, struct icc_node *dst,
ssize_t num_nodes)
{
@@ -561,6 +576,54 @@ struct icc_path *of_icc_get(struct device *dev, const char *name)
}
EXPORT_SYMBOL_GPL(of_icc_get);
+/**
+ * icc_get() - get a path handle between two endpoints
+ * @dev: device pointer for the consumer device
+ * @src: source node name
+ * @dst: destination node name
+ *
+ * This function will search for a path between two endpoints and return an
+ * icc_path handle on success. Use icc_put() to release constraints when they
+ * are not needed anymore.
+ *
+ * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
+ * when the API is disabled.
+ */
+struct icc_path *icc_get(struct device *dev, const char *src, const char *dst)
+{
+ struct icc_node *src_node, *dst_node;
+ struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
+
+ mutex_lock(&icc_lock);
+
+ src_node = node_find_by_name(src);
+ if (!src_node) {
+ dev_err(dev, "%s: invalid src=%s\n", __func__, src);
+ goto out;
+ }
+
+ dst_node = node_find_by_name(dst);
+ if (!dst_node) {
+ dev_err(dev, "%s: invalid dst=%s\n", __func__, dst);
+ goto out;
+ }
+
+ path = path_find(dev, src_node, dst_node);
+ if (IS_ERR(path)) {
+ dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
+ goto out;
+ }
+
+ path->name = kasprintf(GFP_KERNEL, "%s-%s", src_node->name, dst_node->name);
+ if (!path->name) {
+ kfree(path);
+ path = ERR_PTR(-ENOMEM);
+ }
+out:
+ mutex_unlock(&icc_lock);
+ return path;
+}
+
/**
* icc_set_tag() - set an optional tag on a path
* @path: the path we want to tag
diff --git a/drivers/interconnect/internal.h b/drivers/interconnect/internal.h
index f5f82a5c939e..95d6ba27bf78 100644
--- a/drivers/interconnect/internal.h
+++ b/drivers/interconnect/internal.h
@@ -41,4 +41,6 @@ struct icc_path {
struct icc_req reqs[];
};
+struct icc_path *icc_get(struct device *dev, const char *src, const char *dst);
+
#endif
--
2.17.1