Allow users of remoteproc the ability to get a handle to an rproc by
passing a phandle supplied in the user's device tree node. This is
useful in situations that require manual booting of the rproc.
This patch uses the code removed by commit 40e575b1d0b3 ("remoteproc:
remove the get_by_name/put API") for the ref counting but is modified
to use a simple list and locking mechanism and has rproc_get_by_name
replaced with an rproc_get_by_phandle API.
Signed-off-by: Dave Gerlach <d-gerlach@xxxxxx>
Signed-off-by: Suman Anna <s-anna@xxxxxx>
---
v4->v5: Fixed build error from of_find_node_by_phandle when !CONFIG_OF
based on offline discussion.
Documentation/remoteproc.txt | 6 +++++
drivers/remoteproc/remoteproc_core.c | 52 ++++++++++++++++++++++++++++++++++++
include/linux/remoteproc.h | 14 +++++++---
3 files changed, 69 insertions(+), 3 deletions(-)
diff --git a/Documentation/remoteproc.txt b/Documentation/remoteproc.txt
index e6469fd..ef0219f 100644
--- a/Documentation/remoteproc.txt
+++ b/Documentation/remoteproc.txt
@@ -51,6 +51,12 @@ cost.
rproc_shutdown() returns, and users can still use it with a subsequent
rproc_boot(), if needed.
+ struct rproc *rproc_get_by_phandle(phandle phandle)
+ - Find an rproc handle using a device tree phandle. Returns the rproc
+ handle on success, and NULL on failure. This function increments
+ the remote processor's refcount, so always use rproc_put() to
+ decrement it back once rproc isn't needed anymore.
+
3. Typical usage
#include <linux/remoteproc.h>
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index e991512..a898c48 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -44,6 +44,9 @@
#include "remoteproc_internal.h"
+static DEFINE_MUTEX(rproc_list_mutex);
+static LIST_HEAD(rproc_list);
+
typedef int (*rproc_handle_resources_t)(struct rproc *rproc,
struct resource_table *table, int len);
typedef int (*rproc_handle_resource_t)(struct rproc *rproc,
@@ -1144,6 +1147,45 @@ out:
}
EXPORT_SYMBOL(rproc_shutdown);
+#ifdef CONFIG_OF
+/**
+ * rproc_get_by_phandle() - find a remote processor by phandle
+ * @phandle: phandle to the rproc
+ *
+ * Finds an rproc handle using the remote processor's phandle, and then
+ * return a handle to the rproc.
+ *
+ * This function increments the remote processor's refcount, so always
+ * use rproc_put() to decrement it back once rproc isn't needed anymore.
+ *
+ * Returns the rproc handle on success, and NULL on failure.
+ */
+struct rproc *rproc_get_by_phandle(phandle phandle)
+{
+ struct rproc *rproc = NULL, *r;
+ struct device_node *np;
+
+ np = of_find_node_by_phandle(phandle);
+ if (!np)
+ return NULL;
+
+ mutex_lock(&rproc_list_mutex);
+ list_for_each_entry(r, &rproc_list, node) {
+ if (r->dev.parent && r->dev.parent->of_node == np) {
+ rproc = r;
+ get_device(&rproc->dev);
+ break;
+ }
+ }
+ mutex_unlock(&rproc_list_mutex);
+
+ of_node_put(np);
+
+ return rproc;
+}
+EXPORT_SYMBOL(rproc_get_by_phandle);
+#endif /* CONFIG_OF */
+
/**
* rproc_add() - register a remote processor
* @rproc: the remote processor handle to register
@@ -1173,6 +1215,11 @@ int rproc_add(struct rproc *rproc)
if (ret < 0)
return ret;
+ /* expose to rproc_get_by_phandle users */
+ mutex_lock(&rproc_list_mutex);
+ list_add(&rproc->node, &rproc_list);
+ mutex_unlock(&rproc_list_mutex);
+
dev_info(dev, "%s is available\n", rproc->name);
dev_info(dev, "Note: remoteproc is still under development and considered experimental.\n");
@@ -1360,6 +1407,11 @@ int rproc_del(struct rproc *rproc)
/* Free the copy of the resource table */
kfree(rproc->cached_table);
+ /* the rproc is downref'ed as soon as it's removed from the klist */
+ mutex_lock(&rproc_list_mutex);
+ list_del(&rproc->node);
+ mutex_unlock(&rproc_list_mutex);
+
device_del(&rproc->dev);
return 0;
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 78b8a9b..cccfe0b 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -36,11 +36,11 @@
#define REMOTEPROC_H
#include <linux/types.h>
-#include <linux/klist.h>
#include <linux/mutex.h>
#include <linux/virtio.h>
#include <linux/completion.h>
#include <linux/idr.h>
+#include <linux/of.h>
/**
* struct resource_table - firmware resource table header
@@ -375,7 +375,7 @@ enum rproc_crash_type {
/**
* struct rproc - represents a physical remote processor device
- * @node: klist node of this rproc object
+ * @node: list node of this rproc object
* @domain: iommu domain
* @name: human readable name of the rproc
* @firmware: name of firmware file to be loaded
@@ -407,7 +407,7 @@ enum rproc_crash_type {
* @has_iommu: flag to indicate if remote processor is behind an MMU
*/
struct rproc {
- struct klist_node node;
+ struct list_head node;
struct iommu_domain *domain;
const char *name;
const char *firmware;
@@ -504,4 +504,12 @@ static inline struct rproc *vdev_to_rproc(struct virtio_device *vdev)
return rvdev->rproc;
}
+#ifdef CONFIG_OF
+struct rproc *rproc_get_by_phandle(phandle phandle);
+#else
+static inline struct rproc *rproc_get_by_phandle(phandle phandle)
+{
+ return NULL;
+}
+#endif /* CONFIG_OF */
#endif /* REMOTEPROC_H */
--
2.4.1
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