[Intel-gfx] [PATCH 22/48] drm/i915: Use drm_mm for PPGTT PDEs

Chris Wilson chris at chris-wilson.co.uk
Thu Mar 20 12:10:13 CET 2014


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



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