[PATCH 7/7 v2] drm/radeon: Refuse to migrate a prime BO to VRAM. (v2)

[Christian König]

Am 03.04.2017 um 05:35 schrieb raof at ubuntu.com:
> From: Christopher James Halse Rogers <christopher.halse.rogers at canonical.com>
>
> BOs shared via dma-buf, either imported or exported, cannot sensibly be migrated to VRAM
> without breaking the dma-buf sharing. Refuse userspace requests to migrate to VRAM,
> ensure such BOs are not migrated during command submission, and refuse to pin them
> to VRAM.
>
> v2: Don't pin BOs in GTT. Instead, refuse to migrate BOs to VRAM.
>
> Signed-off-by: Christopher James Halse Rogers <christopher.halse.rogers at canonical.com>

Patches #4, #6 and this one (#7) are Reviewed-by: Christian König 
<christian.koenig at amd.com>.

> ---
>   drivers/gpu/drm/radeon/radeon_cs.c     | 10 ++++++++++
>   drivers/gpu/drm/radeon/radeon_gem.c    |  4 ++++
>   drivers/gpu/drm/radeon/radeon_object.c |  5 +++++
>   3 files changed, 19 insertions(+)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
> index a8442f7196d6..df6b58c08544 100644
> --- a/drivers/gpu/drm/radeon/radeon_cs.c
> +++ b/drivers/gpu/drm/radeon/radeon_cs.c
> @@ -164,6 +164,16 @@ static int radeon_cs_parser_relocs(struct radeon_cs_parser *p)
>   			p->relocs[i].allowed_domains = domain;
>   		}
>   
> +		/* Objects shared as dma-bufs cannot be moved to VRAM */
> +		if (p->relocs[i].robj->prime_shared_count) {
> +			p->relocs[i].allowed_domains &= ~RADEON_GEM_DOMAIN_VRAM;
> +			if (!p->relocs[i].allowed_domains) {
> +				DRM_ERROR("BO associated with dma-buf cannot "
> +					  "be moved to VRAM\n");
> +				return -EINVAL;
> +			}
> +		}
> +
>   		p->relocs[i].tv.bo = &p->relocs[i].robj->tbo;
>   		p->relocs[i].tv.shared = !r->write_domain;
>   
> diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c
> index 96683f5b2b1b..067ea7d7658a 100644
> --- a/drivers/gpu/drm/radeon/radeon_gem.c
> +++ b/drivers/gpu/drm/radeon/radeon_gem.c
> @@ -120,6 +120,10 @@ static int radeon_gem_set_domain(struct drm_gem_object *gobj,
>   			return r;
>   		}
>   	}
> +	if (domain == RADEON_GEM_DOMAIN_VRAM && robj->prime_shared_count) {
> +		/* A BO that is associated with a dma-buf cannot be sensibly migrated to VRAM */
> +		return -EINVAL;
> +	}
>   	return 0;
>   }
>   
> diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c
> index 74b276060c20..bec2ec056de4 100644
> --- a/drivers/gpu/drm/radeon/radeon_object.c
> +++ b/drivers/gpu/drm/radeon/radeon_object.c
> @@ -352,6 +352,11 @@ int radeon_bo_pin_restricted(struct radeon_bo *bo, u32 domain, u64 max_offset,
>   
>   		return 0;
>   	}
> +	if (bo->prime_shared_count && domain == RADEON_GEM_DOMAIN_VRAM) {
> +		/* A BO shared as a dma-buf cannot be sensibly migrated to VRAM */
> +		return -EINVAL;
> +	}
> +
>   	radeon_ttm_placement_from_domain(bo, domain);
>   	for (i = 0; i < bo->placement.num_placement; i++) {
>   		/* force to pin into visible video ram */