Re: [PATCH 22/48] drm/i915: Use drm_mm for PPGTT PDEs

Chris Wilson
2014-03-20T11:10:21Z

On Fri, Dec 06, 2013 at 02:11:55PM -0800, Ben Widawsky wrote:
> static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
> {
> +#define GEN6_PD_ALIGN (PAGE_SIZE * 16)
> +#define GEN6_PD_SIZE (GEN6_PPGTT_PD_ENTRIES * PAGE_SIZE)
> struct drm_device *dev = ppgtt->base.dev;
> struct drm_i915_private *dev_priv = dev->dev_private;
> - unsigned first_pd_entry_in_global_pt;
> - int i;
> - int ret = -ENOMEM;
> + int i, ret;
>
> - /* ppgtt PDEs reside in the global gtt pagetable, which has 512*1024
> - * entries. For aliasing ppgtt support we just steal them at the end for
> - * now. */
> - first_pd_entry_in_global_pt = gtt_total_entries(dev_priv->gtt);
> + /* PPGTT PDEs reside in the GGTT and consists of 512 entries. The
> + * allocator works in address space sizes, so it's multiplied by page
> + * size. We allocate at the top of the GTT to avoid fragmentation.
> + */
> + BUG_ON(!drm_mm_initialized(&dev_priv->gtt.base.mm));
> + ret = drm_mm_insert_node_in_range_generic(&dev_priv->gtt.base.mm,
> + &ppgtt->node, GEN6_PD_SIZE,
> + GEN6_PD_ALIGN, 0,
> + 0, dev_priv->gtt.base.total,
> + DRM_MM_SEARCH_DEFAULT);
This could use the simpler drm_mm_insert_node_generic().
-Chris

--
Chris Wilson, Intel Open Source Technology Centre