On 31.03.2017 11:47, Christian König wrote:
> From: Christian König <christian.koenig at amd.com>
>
> Implement AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS using TTM_PL_FLAG_CONTIGUOUS
> instead of a placement limit. That allows us to better handle CPU
> accessible placements.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> Acked-by: Michel Dänzer <michel.daenzer at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 11 +++++------
> drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 14 ++++++++++----
> 2 files changed, 15 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> index d6b2de9..387d190 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> @@ -122,20 +122,19 @@ static void amdgpu_ttm_placement_init(struct amdgpu_device *adev,
>
> if (domain & AMDGPU_GEM_DOMAIN_VRAM) {
> unsigned visible_pfn = adev->mc.visible_vram_size >> PAGE_SHIFT;
> - unsigned lpfn = 0;
> -
> - /* This forces a reallocation if the flag wasn't set before */
> - if (flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS)
> - lpfn = adev->mc.real_vram_size >> PAGE_SHIFT;
>
> places[c].fpfn = 0;
> - places[c].lpfn = lpfn;
> + places[c].lpfn = 0;
> places[c].flags = TTM_PL_FLAG_WC | TTM_PL_FLAG_UNCACHED |
> TTM_PL_FLAG_VRAM;
> +
> if (flags & AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED)
> places[c].lpfn = visible_pfn;
> else
> places[c].flags |= TTM_PL_FLAG_TOPDOWN;
> +
> + if (flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS)
> + places[c].flags |= TTM_PL_FLAG_CONTIGUOUS;
> c++;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> index d710226..af2d172 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> @@ -93,7 +93,6 @@ static int amdgpu_vram_mgr_new(struct ttm_mem_type_manager *man,
> const struct ttm_place *place,
> struct ttm_mem_reg *mem)
> {
> - struct amdgpu_bo *bo = container_of(tbo, struct amdgpu_bo, tbo);
> struct amdgpu_vram_mgr *mgr = man->priv;
> struct drm_mm *mm = &mgr->mm;
> struct drm_mm_node *nodes;
> @@ -107,8 +106,8 @@ static int amdgpu_vram_mgr_new(struct ttm_mem_type_manager *man,
> if (!lpfn)
> lpfn = man->size;
>
> - if (bo->flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS ||
> - place->lpfn || amdgpu_vram_page_split == -1) {
> + if (place->flags & TTM_PL_FLAG_CONTIGUOUS ||
> + amdgpu_vram_page_split == -1) {
> pages_per_node = ~0ul;
> num_nodes = 1;
> } else {
> @@ -126,12 +125,14 @@ static int amdgpu_vram_mgr_new(struct ttm_mem_type_manager *man,
> aflags = DRM_MM_CREATE_TOP;
> }
>
> + mem->start = 0;
> pages_left = mem->num_pages;
>
> spin_lock(&mgr->lock);
> for (i = 0; i < num_nodes; ++i) {
> unsigned long pages = min(pages_left, pages_per_node);
> uint32_t alignment = mem->page_alignment;
> + unsigned long start;
>
> if (pages == pages_per_node)
> alignment = pages_per_node;
> @@ -145,11 +146,16 @@ static int amdgpu_vram_mgr_new(struct ttm_mem_type_manager *man,
> if (unlikely(r))
> goto error;
>
> + /*
> + * Calculate a virtual BO start address to easily check if
> + * everything is CPU accessible.
> + */
> + start = nodes[i].start + nodes[i].size - mem->num_pages;
This might wrap around (be a signed negative number), completely
breaking the max() logic below.
> + mem->start = max(mem->start, start);
> pages_left -= pages;
> }
> spin_unlock(&mgr->lock);
>
> - mem->start = num_nodes == 1 ? nodes[0].start : AMDGPU_BO_INVALID_OFFSET;
If we're going to abuse mem->start anyway, might I suggest just keeping
track of max(nodes[i].start + nodes[i].size), and then setting
mem->start to a magic (macro'd) constant based on whether everything is
in visible VRAM or not?
Then the check in amdgpu_ttm_io_mem_reserve could be simplified accordingly.
Also, I think patches #6 and #5 should be exchanged, otherwise there's a
temporary bug in handling split visible VRAM buffers.
Cheers,
Nicolai
> mem->mm_node = nodes;
>
> return 0;
>
--
Lerne, wie die Welt wirklich ist,
Aber vergiss niemals, wie sie sein sollte.
