Commit f44ffd67 authored by Christian König's avatar Christian König
Browse files

drm/amdgpu: add support for exporting VRAM using DMA-buf v3 



We should be able to do this now after checking all the prerequisites.

v2: fix entrie count in the sgt
v3: manually construct the sg

Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
Acked-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: default avatarSumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/359295
parent 48262cd9

drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c

+43 −13
Original line number Diff line number Diff line
@@ -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);

	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)

{

	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);

	}

}



/**

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h

+11 −1
Original line number Diff line number Diff line
@@ -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);

drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c

+99 −0
Original line number Diff line number Diff line
@@ -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 +459,104 @@ 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_page(sg, NULL, size, 0);

		sg_dma_address(sg) = addr;

		sg_dma_len(sg) = size;

	}

	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

 *

 * @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

 *