Create an rpmsg virtio device to allow message-based communication
with the remote processor (but only if supported by its firmware).
There are several advantages to provide this functionality at
the remoteproc-level:
- to support it, platforms only have to provide their own ->kick()
handler; no need to duplicate the rest of the code.
- the virtio device is created only when the remote processor is
registered and ready to go. No need to depend on initcall magic.
moreover, we only add the virtio device if the firmware really
supports it, and only after we know the supported virtio device features.
- correct device model hierarchy can be set, and that is useful
for natural power management and DMA API behavior.
- when the remote processor crashes (or removed) we only need
to remove the virtio device, and the driver core will take care of
the rest. No need to implement any out-of-bound notifiers.
- we can now easily bind the virtio device to its rproc handle, and
this way we don't need any name-based remoteproc ->get() API.
Currently we only support creating a single rpmsg virtio device per
remote processor, but later this is going to be extended to support
creating numerous virtio devices of other types too (block, net,
console...).
Designed with Brian Swetland <swetland@google.com>.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Brian Swetland <swetland@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg KH <greg@kroah.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Expose several remote processor properties (name, state, trace buffer)
that are helpful for debugging.
This part is extracted to a separate patch just to keep the review load
down.
Designed with Brian Swetland <swetland@google.com>.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Brian Swetland <swetland@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg KH <greg@kroah.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Modern SoCs typically employ a central symmetric multiprocessing (SMP)
application processor running Linux, with several other asymmetric
multiprocessing (AMP) heterogeneous processors running different instances
of operating system, whether Linux or any other flavor of real-time OS.
Booting a remote processor in an AMP configuration typically involves:
- Loading a firmware which contains the OS image
- Allocating and providing it required system resources (e.g. memory)
- Programming an IOMMU (when relevant)
- Powering on the device
This patch introduces a generic framework that allows drivers to do
that. In the future, this framework will also include runtime power
management and error recovery.
Based on (but now quite far from) work done by Fernando Guzman Lugo
<fernando.lugo@ti.com>.
ELF loader was written by Mark Grosen <mgrosen@ti.com>, based on
msm's Peripheral Image Loader (PIL) by Stephen Boyd <sboyd@codeaurora.org>.
Designed with Brian Swetland <swetland@google.com>.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Brian Swetland <swetland@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg KH <greg@kroah.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
