Two carveout reserved memory nodes each have been added for each of the
R5F remote processor devices within both the MCU and MAIN domains on the
TI J7200 EVM boards. These nodes are assigned to the respective rproc
device nodes as well. The first region will be used as the DMA pool for
the rproc device, and the second region will furnish the static carveout
regions for the firmware memory.

An additional reserved memory node is also added to reserve a portion of
the DDR memory to be used for performing inter-processor communication
between all the remote processors running RTOS. 8 MB of memory is reserved
for this purpose, and this accounts for all the vrings and vring buffers
between all the possible pairs of remote processors.

The current carveout addresses and sizes are defined statically for each
device. The R5F processors do not have an MMU, and as such require the
exact memory used by the firmwares to be set-aside. The firmware images
do not require any RSC_CARVEOUT entries in their resource tables either
to allocate the memory for firmware memory segments.

NOTE:
1. The R5F1 carveouts are needed only if the R5F cluster is running in
   Split (non-LockStep) mode. The reserved memory nodes can be disabled
   later on if there is no use-case defined to use the corresponding
   remote processor.
2. The J7200 SoCs have no DSPs and one less R5F cluster compared to J721E
   SoCs. So, while the carveout memories reserved for the R5F clusters
   present on the SoC match to those on J721E, the overall memory map
   reserved for firmwares is quite different.
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>
Link: https://lore.kernel.org/r/20210111184554.6748-4-s-anna@ti.com