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authorArnaud Pouliquen <arnaud.pouliquen@foss.st.com>2022-01-24 13:25:22 +0300
committerBjorn Andersson <bjorn.andersson@linaro.org>2022-03-13 19:49:53 +0300
commitbea9b79c2d10fecf7bfa26e212ecefe61d232e39 (patch)
tree3d0441a0647e5253fc713f73102d154ef7e91c39 /drivers/rpmsg
parentcc9da7de4a7c188fbcc4536a460cb73193a68b46 (diff)
downloadlinux-bea9b79c2d10fecf7bfa26e212ecefe61d232e39.tar.xz
rpmsg: char: Add possibility to use default endpoint of the rpmsg device
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 a default endpoint is created. In this case we have to reuse the default rpmsg device endpoint associated to the channel instead of creating a new one. 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. Add protection in rpmsg_eptdev_ioctl to prevent to destroy a default endpoint. Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> Link: https://lore.kernel.org/r/20220124102524.295783-10-arnaud.pouliquen@foss.st.com
Diffstat (limited to 'drivers/rpmsg')
-rw-r--r--drivers/rpmsg/rpmsg_char.c21
1 files changed, 19 insertions, 2 deletions
diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index bf7311d64e42..8430d568fdd0 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);
@@ -272,6 +285,10 @@ 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);
}