Current implementation create/destroy a new endpoint on each
rpmsg_eptdev_open/rpmsg_eptdev_release calls.
For a rpmsg device created by the NS announcement mechanism we need to
use a unique static endpoint that is the default rpmsg device endpoint
associated to the channel.
This patch prepares the introduction of a rpmsg channel device for the
char device. The rpmsg channel device will require a default endpoint to
communicate to the remote processor.
Add the default_ept field in rpmsg_eptdev structure.This pointer
determines the behavior on rpmsg_eptdev_open and rpmsg_eptdev_release call.
- If default_ept == NULL:
Use the legacy behavior by creating a new endpoint each time
rpmsg_eptdev_open is called and release it when rpmsg_eptdev_release
is called on /dev/rpmsgX device open/close.
- If default_ept is set:
use the rpmsg device default endpoint for the communication.
Address the update of _rpmsg_chrdev_eptdev_create in a separate patch for readability.
Add protection in rpmsg_eptdev_ioctl to prevent to destroy a default endpoint.
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>
---
Update vs previous revision:
- fix comment in rpmsg_eptdev_open
---
drivers/rpmsg/rpmsg_char.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index a39f19161cd6..cf97839f5833 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -50,6 +50,8 @@ static DEFINE_IDA(rpmsg_minor_ida);
* @queue_lock: synchronization of @queue operations
* @queue: incoming message queue
* @readq: wait object for incoming queue
+ * @default_ept: set to channel default endpoint if the default endpoint should be re-used
+ * on device open to prevent endpoint address update.
*/
struct rpmsg_eptdev {
struct device dev;
@@ -60,10 +62,12 @@ struct rpmsg_eptdev {
struct mutex ept_lock;
struct rpmsg_endpoint *ept;
+ struct rpmsg_endpoint *default_ept;
spinlock_t queue_lock;
struct sk_buff_head queue;
wait_queue_head_t readq;
+
};
int rpmsg_chrdev_eptdev_destroy(struct device *dev, void *data)
@@ -121,7 +125,15 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp)
get_device(dev);
- ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo);
+ /*
+ * If the default_ept is set, the rpmsg device default endpoint is used.
+ * Else a new endpoint is created on open that will be destroyed on release.
+ */
+ if (eptdev->default_ept)
+ ept = eptdev->default_ept;
+ else
+ ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo);
+
if (!ept) {
dev_err(dev, "failed to open %s\n", eptdev->chinfo.name);
put_device(dev);
@@ -142,7 +154,8 @@ static int rpmsg_eptdev_release(struct inode *inode, struct file *filp)
/* Close the endpoint, if it's not already destroyed by the parent */
mutex_lock(&eptdev->ept_lock);
if (eptdev->ept) {
- rpmsg_destroy_ept(eptdev->ept);
+ if (!eptdev->default_ept)
+ rpmsg_destroy_ept(eptdev->ept);
eptdev->ept = NULL;
}
mutex_unlock(&eptdev->ept_lock);
@@ -269,6 +282,10 @@ static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd,
if (cmd != RPMSG_DESTROY_EPT_IOCTL)
return -EINVAL;
+ /* Don't allow to destroy a default endpoint. */
+ if (eptdev->default_ept)
+ return -EINVAL;
+
return rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL);
}
--
2.17.1
