On Tue, 7 May 2013 22:57:37 +0100
Chris Wilson <ch...@chris-wilson.co.uk> wrote:
> On Tue, May 07, 2013 at 02:34:31PM -0700, Jesse Barnes wrote:
> > +static void valleyview_setup_pctx(struct drm_device *dev)
> > +{
> > + struct drm_i915_private *dev_priv = dev->dev_private;
> > + struct drm_i915_gem_object *pctx;
> > + unsigned long pctx_paddr;
> > + u32 pcbr;
> > + int pctx_size = 24*1024;
> > +
> > + pcbr = I915_READ(VLV_PCBR);
> > + if (pcbr) {
> > + /* BIOS set it up already, grab the pre-alloc'd space */
> > + int pcbr_offset;
> > +
> > + pcbr_offset = (pcbr & (~4095)) - dev_priv->mm.stolen_base;
> > + pctx =
> > i915_gem_object_create_stolen_for_preallocated(dev_priv->dev,
> > +
> > pcbr_offset,
> > +
> > pcbr_offset,
> > +
> > pctx_size);
>
> We're reserving global GTT space here for someting that just looks like
> it requires contiguous physical memory. This may cause issues if
> something else is already bound to that GTT range. I think we want to
> extend the interface to not reserve GTT space if gtt_offset == -1.
I should have added a comment for this too. The physical range for the
power context must reside in stolen space. So while it needs
contiguous physical memory, it also has a relationship to the stolen
handling. I'd prefer to see a failure here than to try to do something
fancy with funky GTT vs stolen setups... (Still waiting on the BIOS
guys to promise the identity map going forward.)
--
Jesse Barnes, Intel Open Source Technology Center
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx
