[PATCH 10/13] drm/amdgpu: switch the VRAM backend to self alloc

[Matthew Auld]

On Fri, 30 Apr 2021 at 10:25, Christian König
<ckoenig.leichtzumerken at gmail.com> wrote:
>
> Similar to the TTM range manager.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 51 ++++++++++++--------
>  1 file changed, 30 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> index bb01e0fc621c..d59ec07c77bb 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> @@ -23,6 +23,8 @@
>   */
>
>  #include <linux/dma-mapping.h>
> +#include <drm/ttm/ttm_range_manager.h>
> +
>  #include "amdgpu.h"
>  #include "amdgpu_vm.h"
>  #include "amdgpu_res_cursor.h"
> @@ -367,9 +369,9 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
>         struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
>         struct amdgpu_device *adev = to_amdgpu_device(mgr);
>         uint64_t vis_usage = 0, mem_bytes, max_bytes;
> +       struct ttm_range_mgr_node *node;
>         struct drm_mm *mm = &mgr->mm;
>         enum drm_mm_insert_mode mode;
> -       struct drm_mm_node *nodes;
>         unsigned i;
>         int r;
>
> @@ -384,8 +386,8 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
>         /* bail out quickly if there's likely not enough VRAM for this BO */
>         mem_bytes = (u64)mem->num_pages << PAGE_SHIFT;
>         if (atomic64_add_return(mem_bytes, &mgr->usage) > max_bytes) {
> -               atomic64_sub(mem_bytes, &mgr->usage);
> -               return -ENOSPC;
> +               r = -ENOSPC;
> +               goto error_sub;
>         }
>
>         if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
> @@ -403,13 +405,15 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
>                 num_nodes = DIV_ROUND_UP(mem->num_pages, pages_per_node);
>         }
>
> -       nodes = kvmalloc_array((uint32_t)num_nodes, sizeof(*nodes),
> -                              GFP_KERNEL | __GFP_ZERO);
> -       if (!nodes) {
> -               atomic64_sub(mem_bytes, &mgr->usage);
> -               return -ENOMEM;
> +       node = kvmalloc(struct_size(node, mm_nodes, num_nodes),
> +                         GFP_KERNEL | __GFP_ZERO);

Alignment.

> +       if (!node) {
> +               r = -ENOMEM;
> +               goto error_sub;
>         }
>
> +       ttm_resource_init(tbo, place, &node->base);
> +
>         mode = DRM_MM_INSERT_BEST;
>         if (place->flags & TTM_PL_FLAG_TOPDOWN)
>                 mode = DRM_MM_INSERT_HIGH;
> @@ -428,8 +432,9 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
>                 if (pages >= pages_per_node)
>                         alignment = pages_per_node;
>
> -               r = drm_mm_insert_node_in_range(mm, &nodes[i], pages, alignment,
> -                                               0, place->fpfn, lpfn, mode);
> +               r = drm_mm_insert_node_in_range(mm, &node->mm_nodes[i], pages,
> +                                               alignment, 0, place->fpfn,
> +                                               lpfn, mode);
>                 if (unlikely(r)) {
>                         if (pages > pages_per_node) {
>                                 if (is_power_of_2(pages))
> @@ -438,11 +443,11 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
>                                         pages = rounddown_pow_of_two(pages);
>                                 continue;
>                         }
> -                       goto error;
> +                       goto error_free;
>                 }
>
> -               vis_usage += amdgpu_vram_mgr_vis_size(adev, &nodes[i]);
> -               amdgpu_vram_mgr_virt_start(mem, &nodes[i]);
> +               vis_usage += amdgpu_vram_mgr_vis_size(adev, &node->mm_nodes[i]);
> +               amdgpu_vram_mgr_virt_start(mem, &node->mm_nodes[i]);
>                 pages_left -= pages;
>                 ++i;
>
> @@ -455,16 +460,17 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
>                 mem->placement |= TTM_PL_FLAG_CONTIGUOUS;
>
>         atomic64_add(vis_usage, &mgr->vis_usage);
> -       mem->mm_node = nodes;
> +       mem->mm_node = &node->mm_nodes[0];
>         return 0;
>
> -error:
> +error_free:
>         while (i--)
> -               drm_mm_remove_node(&nodes[i]);
> +               drm_mm_remove_node(&node->mm_nodes[i]);
>         spin_unlock(&mgr->lock);
> -       atomic64_sub(mem->num_pages << PAGE_SHIFT, &mgr->usage);
> +       kvfree(node);
>
> -       kvfree(nodes);
> +error_sub:
> +       atomic64_sub(mem_bytes, &mgr->usage);
>         return r;
>  }
>
> @@ -481,13 +487,17 @@ static void amdgpu_vram_mgr_del(struct ttm_resource_manager *man,
>  {
>         struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
>         struct amdgpu_device *adev = to_amdgpu_device(mgr);
> -       struct drm_mm_node *nodes = mem->mm_node;
> +       struct ttm_range_mgr_node *node;
>         uint64_t usage = 0, vis_usage = 0;
>         unsigned pages = mem->num_pages;
> +       struct drm_mm_node *nodes;
>
>         if (!mem->mm_node)
>                 return;
>
> +       node = to_ttm_range_mgr_node(mem);
> +       nodes = &node->mm_nodes[0];
> +
>         spin_lock(&mgr->lock);
>         while (pages) {
>                 pages -= nodes->size;
> @@ -502,8 +512,7 @@ static void amdgpu_vram_mgr_del(struct ttm_resource_manager *man,
>         atomic64_sub(usage, &mgr->usage);
>         atomic64_sub(vis_usage, &mgr->vis_usage);
>
> -       kvfree(mem->mm_node);
> -       mem->mm_node = NULL;

Not worth keeping the mm_node = NULL?

Reviewed-by: Matthew Auld <matthew.auld at intel.com>


> +       kvfree(node);
>  }
>
>  /**
> --
> 2.25.1
>