Re: [PATCH] ARM: at91: Fix: Change internal SRAM memory type to"MT_MEMORY_SO"

From: Russell King - ARM Linux
Date: Fri May 24 2013 - 12:41:45 EST


On Fri, May 24, 2013 at 04:03:22PM +0200, Jean-Christophe PLAGNIOL-VILLARD wrote:
> On 12:20 Fri 24 May , Russell King - ARM Linux wrote:
> > On Fri, May 24, 2013 at 07:11:04AM +0000, Yang, Wenyou wrote:
> > > The story is: for sama5d3x with Cortex-A5 core, if not so, when copying
> > > code snippet to the internal SRAM, then jump to run this code, but fail
> > > to run.
> >
> > And that is where your mistake is - you forgot that you're working with
> > a CPU with harvard caches which will require some cache maintanence
> > between copying the code and executing it.
> >
> > You want to look at flush_icache_range() rather than making this memory
> > strongly ordered.
>
> I understand your point but today we map a SRAM as MT_DEVICE

If you map SRAM as MT_DEVICE then you won't be able to execute code from
it. It needs to be a normal memory mapping.
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