[Intel-gfx] [PATCH 5/6] drm/amdgpu: add support for exporting VRAM using DMA-buf v2
Alex Deucher
alexdeucher at gmail.com
Wed Mar 11 15:08:03 UTC 2020
On Wed, Mar 11, 2020 at 9:52 AM Christian König
<ckoenig.leichtzumerken at gmail.com> wrote:
>
> We should be able to do this now after checking all the prerequisites.
>
> v2: fix entrie count in the sgt
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 56 ++++++++---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h | 12 ++-
> drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 97 ++++++++++++++++++++
> 3 files changed, 151 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> index bbf67800c8a6..43d8ed7dbd00 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> @@ -276,14 +276,21 @@ static struct sg_table *amdgpu_dma_buf_map(struct dma_buf_attachment *attach,
> struct dma_buf *dma_buf = attach->dmabuf;
> struct drm_gem_object *obj = dma_buf->priv;
> struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
> + struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> struct sg_table *sgt;
> long r;
>
> if (!bo->pin_count) {
> - /* move buffer into GTT */
> + /* move buffer into GTT or VRAM */
> struct ttm_operation_ctx ctx = { false, false };
> + unsigned domains = AMDGPU_GEM_DOMAIN_GTT;
>
> - amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_GTT);
> + if (bo->preferred_domains & AMDGPU_GEM_DOMAIN_VRAM &&
> + attach->peer2peer) {
> + bo->flags |= AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;
> + domains |= AMDGPU_GEM_DOMAIN_VRAM;
> + }
> + amdgpu_bo_placement_from_domain(bo, domains);
> r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
> if (r)
> return ERR_PTR(r);
> @@ -293,20 +300,34 @@ static struct sg_table *amdgpu_dma_buf_map(struct dma_buf_attachment *attach,
> return ERR_PTR(-EBUSY);
> }
>
> - sgt = drm_prime_pages_to_sg(bo->tbo.ttm->pages, bo->tbo.num_pages);
> - if (IS_ERR(sgt))
> - return sgt;
> -
> - if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
> - DMA_ATTR_SKIP_CPU_SYNC))
> - goto error_free;
> + switch (bo->tbo.mem.mem_type) {
> + case TTM_PL_TT:
> + sgt = drm_prime_pages_to_sg(bo->tbo.ttm->pages,
> + bo->tbo.num_pages);
> + if (IS_ERR(sgt))
> + return sgt;
> +
> + if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
> + DMA_ATTR_SKIP_CPU_SYNC))
> + goto error_free;
> + break;
> +
> + case TTM_PL_VRAM:
> + r = amdgpu_vram_mgr_alloc_sgt(adev, &bo->tbo.mem, attach->dev,
> + dir, &sgt);
> + if (r)
> + return ERR_PTR(r);
> + break;
> + default:
> + return ERR_PTR(-EINVAL);
> + }
>
> return sgt;
>
> error_free:
> sg_free_table(sgt);
> kfree(sgt);
> - return ERR_PTR(-ENOMEM);
> + return ERR_PTR(-EBUSY);
> }
>
> /**
> @@ -322,9 +343,18 @@ static void amdgpu_dma_buf_unmap(struct dma_buf_attachment *attach,
> struct sg_table *sgt,
> enum dma_data_direction dir)
> {
> - dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
> - sg_free_table(sgt);
> - kfree(sgt);
> + struct dma_buf *dma_buf = attach->dmabuf;
> + struct drm_gem_object *obj = dma_buf->priv;
> + struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
> + struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> +
> + if (sgt->sgl->page_link) {
> + dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
> + sg_free_table(sgt);
> + kfree(sgt);
> + } else {
> + amdgpu_vram_mgr_free_sgt(adev, attach->dev, dir, sgt);
> + }
> }
>
> /**
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
> index 7551f3729445..a99d813b23a5 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
> @@ -24,8 +24,9 @@
> #ifndef __AMDGPU_TTM_H__
> #define __AMDGPU_TTM_H__
>
> -#include "amdgpu.h"
> +#include <linux/dma-direction.h>
> #include <drm/gpu_scheduler.h>
> +#include "amdgpu.h"
>
> #define AMDGPU_PL_GDS (TTM_PL_PRIV + 0)
> #define AMDGPU_PL_GWS (TTM_PL_PRIV + 1)
> @@ -74,6 +75,15 @@ uint64_t amdgpu_gtt_mgr_usage(struct ttm_mem_type_manager *man);
> int amdgpu_gtt_mgr_recover(struct ttm_mem_type_manager *man);
>
> u64 amdgpu_vram_mgr_bo_visible_size(struct amdgpu_bo *bo);
> +int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev,
> + struct ttm_mem_reg *mem,
> + struct device *dev,
> + enum dma_data_direction dir,
> + struct sg_table **sgt);
> +void amdgpu_vram_mgr_free_sgt(struct amdgpu_device *adev,
> + struct device *dev,
> + enum dma_data_direction dir,
> + struct sg_table *sgt);
> uint64_t amdgpu_vram_mgr_usage(struct ttm_mem_type_manager *man);
> uint64_t amdgpu_vram_mgr_vis_usage(struct ttm_mem_type_manager *man);
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> index 82a3299e53c0..c6e7f00c5b21 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> @@ -22,6 +22,7 @@
> * Authors: Christian König
> */
>
> +#include <linux/dma-mapping.h>
> #include "amdgpu.h"
> #include "amdgpu_vm.h"
> #include "amdgpu_atomfirmware.h"
> @@ -458,6 +459,102 @@ static void amdgpu_vram_mgr_del(struct ttm_mem_type_manager *man,
> mem->mm_node = NULL;
> }
>
> +/**
> + * amdgpu_vram_mgr_alloc_sgt - allocate and fill a sg table
> + *
> + * @adev: amdgpu device pointer
> + * @mem: TTM memory object
> + * @dev: the other device
> + * @dir: dma direction
> + * @sgt: resulting sg table
> + *
> + * Allocate and fill a sg table from a VRAM allocation.
> + */
> +int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev,
> + struct ttm_mem_reg *mem,
> + struct device *dev,
> + enum dma_data_direction dir,
> + struct sg_table **sgt)
> +{
> + struct drm_mm_node *node;
> + struct scatterlist *sg;
> + int num_entries = 0;
> + unsigned int pages;
> + int i, r;
> +
> + *sgt = kmalloc(sizeof(*sg), GFP_KERNEL);
> + if (!*sgt)
> + return -ENOMEM;
> +
> + for (pages = mem->num_pages, node = mem->mm_node;
> + pages; pages -= node->size, ++node)
> + ++num_entries;
> +
> + r = sg_alloc_table(*sgt, num_entries, GFP_KERNEL);
> + if (r)
> + goto error_free;
> +
> + for_each_sg((*sgt)->sgl, sg, num_entries, i)
> + sg->length = 0;
> +
> + node = mem->mm_node;
> + for_each_sg((*sgt)->sgl, sg, num_entries, i) {
> + phys_addr_t phys = (node->start << PAGE_SHIFT) +
> + adev->gmc.aper_base;
> + size_t size = node->size << PAGE_SHIFT;
> + dma_addr_t addr;
> +
> + ++node;
> + addr = dma_map_resource(dev, phys, size, dir,
> + DMA_ATTR_SKIP_CPU_SYNC);
> + r = dma_mapping_error(dev, addr);
> + if (r)
> + goto error_unmap;
> +
> + sg_set_dma_addr(sg, addr, size, 0);
> + }
> + return 0;
> +
> +error_unmap:
> + for_each_sg((*sgt)->sgl, sg, num_entries, i) {
> + if (!sg->length)
> + continue;
> +
> + dma_unmap_resource(dev, sg->dma_address,
> + sg->length, dir,
> + DMA_ATTR_SKIP_CPU_SYNC);
> + }
> + sg_free_table(*sgt);
> +
> +error_free:
> + kfree(*sgt);
> + return r;
> +}
> +
> +/**
> + * amdgpu_vram_mgr_alloc_sgt - allocate and fill a sg table
This should be:
amdgpu_vram_mgr_free_sgt - unmap and free an sg table
> + *
> + * @adev: amdgpu device pointer
> + * @sgt: sg table to free
> + *
> + * Free a previously allocate sg table.
> + */
> +void amdgpu_vram_mgr_free_sgt(struct amdgpu_device *adev,
> + struct device *dev,
> + enum dma_data_direction dir,
> + struct sg_table *sgt)
> +{
> + struct scatterlist *sg;
> + int i;
> +
> + for_each_sg(sgt->sgl, sg, sgt->nents, i)
> + dma_unmap_resource(dev, sg->dma_address,
> + sg->length, dir,
> + DMA_ATTR_SKIP_CPU_SYNC);
> + sg_free_table(sgt);
> + kfree(sgt);
> +}
> +
> /**
> * amdgpu_vram_mgr_usage - how many bytes are used in this domain
> *
> --
> 2.17.1
>
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