[0/2] Add character device interface to remoteproc

Message

Rishabh Bhatnagar March 26, 2020, 4:50 p.m. UTC

This patch series adds a character device interface to remoteproc
framework. This interface can be used by userspace clients in order
to boot and shutdown the remote processor.
Currently there is only a sysfs interface which the userspace
clients can use. If a usersapce application crashes after booting
the remote processor through the sysfs interface the remote processor
does not get any indication about the crash. It might still assume
that the  application is running.
For example modem uses remotefs service to data from disk/flash memory.
If the remotefs service crashes, modem still keeps on requesting data
which might lead to crash on modem. Even if the service is restarted the
file handles modem requested previously would become stale.
Adding a character device interface makes the remote processor tightly
coupled with the user space application. A crash of the application
leads to a close on the file descriptors therefore shutting down the
remoteproc.

Rishabh Bhatnagar (2):
  remoteproc: Add userspace char device driver
  remoteproc: core: Register the character device interface

 drivers/remoteproc/Makefile               |   1 +
 drivers/remoteproc/remoteproc_core.c      |   8 +-
 drivers/remoteproc/remoteproc_internal.h  |   3 +
 drivers/remoteproc/remoteproc_userspace.c | 126 ++++++++++++++++++++++++++++++
 include/linux/remoteproc.h                |   2 +
 5 files changed, 139 insertions(+), 1 deletion(-)
 create mode 100644 drivers/remoteproc/remoteproc_userspace.c