Hi Ohad,

On Tue, Jul 29, 2014 at 10:33 PM, Suman Anna [off-list ref] wrote:

quoted

We currently have two usecases. The primary usecase is the WkupM3
processor on TI Sitara AM335x/AM437x SoCs used for suspend/resume
management. This series is a dependency for the WkupM3 remoteproc driver
that Dave posted [1]. More details are in section 8.1.4.6 of the AM335x
TRM [2]. The program/data sections for this processor all _needs_ to be
in the two internal memory RAMS (16K Unified RAM and 8K Data RAM), and
there is no MMU for this processor. The current RSC_CARVEOUT and
RSC_DEVMEM do not fit to describe this type of memory (we neither
allocate memory through dma api nor do we need to map these into an MMU).

Thanks for the details.

Can we define a CMA block for these regions, and then just use
carveout resource entries instead of the ioremap approach?

I am looking at refreshing these patches, and found that I missed
responding to this message.

These processors need to use their internal RAM for loading, which is
not for generic usage by the kernel, so defining a CMA block for this
memory doesn't make sense.

This may require some changes in remoteproc which we'll need to think
about, but it sounds like it may fit the problem better instead of
forcing ioremap to provide a regular pointer (we're supposed to use
ioremaped memory only with memory primitives such as readl/writel/..).

Will it suffice to replace the memcpy() with memcpy_toio()?

regards
Suman