[Intel-gfx] [PATCH v4 4/8] drm/i915/selftests: Add mock selftest for remapped vmas

[Chris Wilson]

Quoting Ville Syrjala (2018-10-23 17:03:01)
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Extend the rotated vma mock selftest to cover remapped vmas as
> well.
> 
> TODO: reindent the loops I guess? Left like this for now to
> ease review
> 
> v2: Include the vma type in the error message (Chris)
> 
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
> +static struct scatterlist *
> +assert_remapped(struct drm_i915_gem_object *obj,
> +               const struct intel_remapped_info *r, unsigned int n,
> +               struct scatterlist *sg)
> +{
> +       unsigned int x, y;
> +
> +       for (y = 0; y < r->plane[n].height; y++) {
> +               for (x = 0; x < r->plane[n].width; x++) {
> +                       unsigned long src_idx;
> +                       dma_addr_t src;
> +
> +                       if (!sg) {
> +                               pr_err("Invalid sg table: too short at plane %d, (%d, %d)!\n",
> +                                      n, x, y);
> +                               return ERR_PTR(-EINVAL);
> +                       }
> +
> +                       src_idx = remapped_index(r, n, x, y);
> +                       src = i915_gem_object_get_dma_address(obj, src_idx);
> +
> +                       if (sg_dma_len(sg) != PAGE_SIZE) {
> +                               pr_err("Invalid sg.length, found %d, expected %lu for remapped page (%d, %d) [src index %lu]\n",
> +                                      sg_dma_len(sg), PAGE_SIZE,
> +                                      x, y, src_idx);
> +                               return ERR_PTR(-EINVAL);
> +                       }

Meh, seems overly restrictive for a remapped view. But given we are
iterating by pages and have restricted the construction to be page
aligned (though didn't we use I915_GTT_PAGE_SIZE in the constructor?),
seems reasonable for a first stab.

~o~ it fits the series, but it doesn't validate potential changes.

Acked-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris