[Intel-gfx] [PATCH 17/26] drm/i915: Clean up pagetable DMA map & unmap

[Chris Wilson]

On Mon, Mar 17, 2014 at 10:48:49PM -0700, Ben Widawsky wrote:
> Map and unmap are common operations across all generations for
> pagetables. With a simple helper, we can get a nice net code reduction
> as well as simplified complexity.
> 
> There is some room for optimization here, for instance with the multiple
> page mapping, that can be done in one pci_map operation. In that case
> however, the max value we'll ever see there is 512, and so I believe the
> simpler code makes this a worthwhile trade-off. Also, the range mapping
> functions are place holders to help transition the code. Eventually,
> mapping will only occur during a page allocation which will always be a
> discrete operation.

Nice. (Except still uneasy about that WARN_ON ;-)
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre