rpmsg: Remove usage of the deprecated ida_simple_xx() API

ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().

Note that the upper limit of ida_simple_get() is exclusive, but the one of
ida_alloc_max() is inclusive. So a -1 has been added when needed.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/c09ee5b66d451bf97d14c167048549aa0824ee06.1705225049.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

rpmsg: ctrl: Add lock to rpmsg_ctrldev_remove

Call to rpmsg_ctrldev_ioctl() and rpmsg_ctrldev_remove() must be synchronized.
In present code rpmsg_ctrldev_remove() is not protected with lock, therefore
new char device creation can succeed through rpmsg_ctrldev_ioctl() call. At the
same time call to rpmsg_ctrldev_remove() function for ctrl device removal will
free associated rpdev device. As char device creation already succeeded, user
space is free to issue open() call which maps to rpmsg_create_ept() in kernel.
rpmsg_create_ept() function tries to reference rpdev which has already been
freed through rpmsg_ctrldev_remove(). Issue is predominantly seen in aggressive
reboot tests where rpmsg_ctrldev_ioctl() and rpmsg_ctrldev_remove() can race with
each other.

Adding lock in rpmsg_ctrldev_remove() avoids any new char device creation
through rpmsg_ctrldev_ioctl() while remove call is already in progress.

Signed-off-by: Deepak Kumar Singh <quic_deesin@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/1663584840-15762-3-git-send-email-quic_deesin@quicinc.com

rpmsg: ctrl: Introduce new RPMSG_CREATE/RELEASE_DEV_IOCTL controls

Allow the user space application to create and release an rpmsg device
by adding RPMSG_CREATE_DEV_IOCTL and RPMSG_RELEASE_DEV_IOCTL ioctrls to
the /dev/rpmsg_ctrl interface

The RPMSG_CREATE_DEV_IOCTL Ioctl can be used to instantiate a local rpmsg
device.
Depending on the back-end implementation, the associated rpmsg driver is
probed and a NS announcement can be sent to the remote processor.

The RPMSG_RELEASE_DEV_IOCTL allows the user application to release a
rpmsg device created either by the remote processor or with the
RPMSG_CREATE_DEV_IOCTL call.
Depending on the back-end implementation, the associated rpmsg driver is
removed and a NS destroy rpmsg can be sent to the remote processor.

Suggested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220124102524.295783-12-arnaud.pouliquen@foss.st.com

rpmsg: Update rpmsg_chrdev_register_device function

The rpmsg_chrdev driver has been replaced by the rpmsg_ctrl driver
for the /dev/rpmsg_ctrlX devices management. The reference for the
driver override is now the rpmsg_ctrl.

Update the rpmsg_chrdev_register_device function to reflect the update,
and rename the function to use the rpmsg_ctrldev prefix.

The platform drivers are updated accordingly.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220124102524.295783-8-arnaud.pouliquen@foss.st.com

rpmsg: Move the rpmsg control device from rpmsg_char to rpmsg_ctrl

Create the rpmsg_ctrl.c module and move the code related to the
rpmsg_ctrldev device in this new module.

Add the dependency between rpmsg_char and rpmsg_ctrl in the
kconfig file:

1) RPMSG_CTRL can set as module or built-in if
RPMSG=y || RPMSG_CHAR=y || RPMSG_CHAR=n

2) RPMSG_CTRL can not be set as built-in if
RPMSG=m || RPMSG_CHAR=m

Note that RPMGH_CHAR and RPMSG_CTRL can be activated separately.
Therefore, the RPMSG_CTRL configuration must be set for backwards compatibility.

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/20220124102524.295783-4-arnaud.pouliquen@foss.st.com