Re: IO space memcpy support for userspace.

From: Carlos O'Donell
Date: Sat Dec 06 2008 - 11:08:16 EST

On Sat, Dec 6, 2008 at 1:34 AM, Dave Airlie <airlied@xxxxxxxxx> wrote:
> Its a real pain in the ass with dynamic buffer objects, we don't want userspace
> to care where they are located, the kernel migrates them in/out of
> video memory, GART, local RAM etc.
> However I suspect I just need on these platforms to ban any CPU
> accesses to pixmaps in VRAM. However
> sw fallbacks to the front buffer will always need these accesses.
> Its going to be a real pain getting any traction this stuff upstream
> ( where the world is x86 and maybe the odd powerpc, having
> to do special accessors for shithouse hw is never going to be fun.

Is there no case on x86 when this matters?

What about ARM, ColdFire or MIPS?

As the embedded market continues to grow I hope to see on
more hardware with different memory access rules.

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