[PATCH 0/2] Add character device interface to remoteproc

From: Rishabh Bhatnagar
Date: Thu Mar 26 2020 - 12:51:01 EST


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

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