| Message ID | 20211108141937.13016-10-arnaud.pouliquen@foss.st.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Restructure the rpmsg_char driver and introduce rpmsg_ctrl driver | expand |
On Mon 08 Nov 08:19 CST 2021, Arnaud Pouliquen wrote: > 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@foss.st.com> > --- > 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 3daf62df69a0..6a01e8e1c111 100644 > --- a/drivers/rpmsg/rpmsg_char.c > +++ b/drivers/rpmsg/rpmsg_char.c > @@ -47,6 +47,8 @@ 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; > @@ -57,10 +59,12 @@ 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) > @@ -118,7 +122,15 @@ 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 to true, the rpmsg device default endpoint is used. default_ept will no longer be "set to true". Regards, Bjorn > + * 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); > @@ -139,7 +151,8 @@ 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); > @@ -266,6 +279,10 @@ 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 >
diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c index 3daf62df69a0..6a01e8e1c111 100644 --- a/drivers/rpmsg/rpmsg_char.c +++ b/drivers/rpmsg/rpmsg_char.c @@ -47,6 +47,8 @@ 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; @@ -57,10 +59,12 @@ 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) @@ -118,7 +122,15 @@ 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 to true, 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); @@ -139,7 +151,8 @@ 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); @@ -266,6 +279,10 @@ 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); }
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@foss.st.com> --- drivers/rpmsg/rpmsg_char.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-)