[Intel-gfx] [PATCH 08/22] drm/i915: Fallback to single page GTT mmappings for relocations

[Joonas Lahtinen]

On ti, 2016-08-16 at 11:42 +0100, Chris Wilson wrote:
> @@ -360,8 +361,18 @@ static void reloc_cache_fini(struct reloc_cache *cache)
>  		kunmap_atomic(vaddr);
>  		i915_gem_object_unpin_pages((struct drm_i915_gem_object *)cache->node.mm);
>  	} else {
> +		wmb();

Why wmb() here? In other spot it's inside if (cache->node.allocated)?
This alters the original code path, too.

>  		io_mapping_unmap_atomic(vaddr);
> -		i915_vma_unpin((struct i915_vma *)cache->node.mm);
> +		if (cache->node.allocated) {
> +			struct i915_ggtt *ggtt = &cache->i915->ggtt;
> +
> +			ggtt->base.clear_range(&ggtt->base,
> +					       cache->node.start,
> +					       cache->node.size,
> +					       true);
> +			drm_mm_remove_node(&cache->node);
> +		} else
> +			i915_vma_unpin((struct i915_vma *)cache->node.mm);

Pretty sure this needs braces too; "This does not apply if only one
branch of a conditional statement is a single statement; in the latter
case use braces in both branches:"

> @@ -415,21 +437,38 @@ static void *reloc_iomap(struct drm_i915_gem_object *obj,
>  
>  		vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0,
>  					       PIN_MAPPABLE | PIN_NONBLOCK);
> -		if (IS_ERR(vma))
> -			return NULL;
> +		if (IS_ERR(vma)) {
> +			memset(&cache->node, 0, sizeof(cache->node));
> +			ret = drm_mm_insert_node_in_range_generic
> +				(&ggtt->base.mm, &cache->node,

That brace sure needs to be on the previous line. With above fixes;

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

Regards, Joonas
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation