[Intel-gfx] [PATCH 1/3] drm/i915: Use readl/writel for ring buffer access

[Chris Wilson]

On Thu, Apr 14, 2016 at 11:59:29AM +0100, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> We know ringbuffers are memory and not ports so if we use readl
> and writel instead of ioread32 and iowrite32 (which dispatch to
> the very same functions after checking the address range) we
> avoid generating functions calls and branching on every access.

We don't need to use readl/write at all, since they are normal memory
on llc, and on x86 we can pretend that iomaps (!llc/stolen) are as well.

This patch is in the queue along with killing the incorrect spare iomem
annotation.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre