Re: [Qemu-devel] [PATCH] dma: Define dma_context_memory and use in sysbus-ohci

[David Gibson]

On Thu, Oct 25, 2012 at 08:33:13PM +1000, Peter Crosthwaite wrote:
> On Oct 24, 2012 3:27 AM, "Peter Maydell" <address@hidden> wrote:
> >
> > Define a new global dma_context_memory which is a DMAContext corresponding
> > to the global address_space_memory AddressSpace. This can be used by
> > sysbus peripherals like sysbus-ohci which need to do DMA.
> >
> > In particular, use it in the sysbus-ohci device, which fixes a
> > segfault when attempting to use that device.
> >
> > Signed-off-by: Peter Maydell <address@hidden>
> Reviewed-by: Peter Crosthwaite <address@hidden>

Hrm.  So, as I originally conceived DMAContext, a NULL context pointer
means "no translation" which is to say that DMA addresses are the same
as memory space addresses.  Which would mean a context explicitly for
this purpose should not be necessary.

Has this assumption changed with the newer memory region integrated
dma context stuff?

-- 
David Gibson                    | I'll have my music baroque, and my code
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                                | _way_ _around_!
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