[Intel-gfx] [PATCH 16/34] drm: kselftest for drm_mm and top-down alignment
Joonas Lahtinen
joonas.lahtinen at linux.intel.com
Wed Dec 14 11:51:03 UTC 2016
On ma, 2016-12-12 at 11:53 +0000, Chris Wilson wrote:
> Check that if we request top-down allocation with a particular alignment
> from drm_mm_insert_node() that the start of the node matches our
> request.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Assuming magic numbers be gone in next iteration.
> +static int igt_topdown_align(void *ignored)
> +{
> + struct drm_mm mm;
> + struct drm_mm_node tmp, resv;
> + int ret = -EINVAL;
> + int n, m, err;
> +
> + drm_mm_init(&mm, 0, ~0ull);
> + memset(&tmp, 0, sizeof(tmp));
> + memset(&resv, 0, sizeof(resv));
> +
> + for (m = 0; m < 32; m++) {
> + u64 end = ~0ull;
> +
> + if (m) {
> + resv.size = BIT_ULL(m);
> + end -= resv.size;
> + resv.start = end;
> +
> + err = drm_mm_reserve_node(&mm, &resv);
> + if (err) {
> + pr_err("reservation of sentinel node failed\n");
> + ret = err;
> + goto out;
> + }
> + }
> +
> + for (n = 0; n < 63 - m; n++) {
> + u64 align = BIT_ULL(n);
DRM_MM_BUG_ON(end % align); to protect somebody from modifying? (or end
& (align - 1))
> +
> + err = drm_mm_insert_node_generic(&mm, &tmp, 1, align, 0,
> + DRM_MM_SEARCH_BELOW,
> + DRM_MM_CREATE_TOP);
> + drm_mm_remove_node(&tmp);
Could move this after if (err) again and in the rest of the code, too.
Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Regards, Joonas
--
Joonas Lahtinen
Open Source Technology Center
Intel Corporation
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