Extend current implementation of SG_TABLE construction method to
allow exportation of sub-buffers of a VRAM BO. This capability will
enable logical partitioning of a VRAM BO into multiple non-overlapping
sub-buffers. One example of this use case is to partition a VRAM BO
into two sub-buffers, one for SRC and another for DST.
Signed-off-by: Ramesh Errabolu <Ramesh.Errabolu@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 6 ++--
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h | 1 +
drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 32 ++++++++++++++------
3 files changed, 27 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
index e0c4f7c7f1b9..57534b93bd91 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
@@ -255,6 +255,7 @@ static struct sg_table *amdgpu_dma_buf_map(struct dma_buf_attachment *attach,
struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
struct sg_table *sgt;
+ u64 num_bytes;
long r;
if (!bo->tbo.pin_count) {
@@ -291,8 +292,9 @@ static struct sg_table *amdgpu_dma_buf_map(struct dma_buf_attachment *attach,
break;
case TTM_PL_VRAM:
- r = amdgpu_vram_mgr_alloc_sgt(adev, &bo->tbo.mem, attach->dev,
- dir, &sgt);
+ num_bytes = bo->tbo.mem.num_pages << PAGE_SHIFT;
+ r = amdgpu_vram_mgr_alloc_sgt(adev, &bo->tbo.mem, 0, num_bytes,
+ attach->dev, dir, &sgt);
if (r)
return ERR_PTR(r);
break;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
index dec0db8b0b13..9e38475e0f8d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
@@ -112,6 +112,7 @@ int amdgpu_gtt_mgr_recover(struct ttm_resource_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_resource *mem,
+ u64 offset, u64 size,
struct device *dev,
enum dma_data_direction dir,
struct sg_table **sgt);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index 592a2dd16493..fcdee0deba16 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -25,6 +25,7 @@
#include <linux/dma-mapping.h>
#include "amdgpu.h"
#include "amdgpu_vm.h"
+#include "amdgpu_res_cursor.h"
#include "amdgpu_atomfirmware.h"
#include "atom.h"
@@ -565,6 +566,8 @@ static void amdgpu_vram_mgr_del(struct ttm_resource_manager *man,
*
* @adev: amdgpu device pointer
* @mem: TTM memory object
+ * @offset: byte offset from the base of VRAM BO
+ * @length: number of bytes to export in sg_table
* @dev: the other device
* @dir: dma direction
* @sgt: resulting sg table
@@ -573,39 +576,45 @@ static void amdgpu_vram_mgr_del(struct ttm_resource_manager *man,
*/
int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev,
struct ttm_resource *mem,
+ u64 offset, u64 length,
struct device *dev,
enum dma_data_direction dir,
struct sg_table **sgt)
{
- struct drm_mm_node *node;
+ struct amdgpu_res_cursor cursor;
struct scatterlist *sg;
int num_entries = 0;
- unsigned int pages;
int i, r;
*sgt = kmalloc(sizeof(**sgt), GFP_KERNEL);
if (!*sgt)
return -ENOMEM;
- for (pages = mem->num_pages, node = mem->mm_node;
- pages; pages -= node->size, ++node)
- ++num_entries;
+ // Determine the number of DRM_MM nodes to export
+ amdgpu_res_first(mem, offset, length, &cursor);
+ while (cursor.remaining) {
+ num_entries++;
+ amdgpu_res_next(&cursor, cursor.size);
+ }
r = sg_alloc_table(*sgt, num_entries, GFP_KERNEL);
if (r)
goto error_free;
+ // Initialize scatterlist nodes of sg_table
for_each_sgtable_sg((*sgt), sg, i)
sg->length = 0;
- node = mem->mm_node;
+ // Walk down DRM_MM nodes to populate scatterlist nodes
+ // @note: Use iterator api to get first the DRM_MM node
+ // and the number of bytes from it. Access the following
+ // DRM_MM node(s) if more buffer needs to exported
+ amdgpu_res_first(mem, offset, length, &cursor);
for_each_sgtable_sg((*sgt), sg, i) {
- phys_addr_t phys = (node->start << PAGE_SHIFT) +
- adev->gmc.aper_base;
- size_t size = node->size << PAGE_SHIFT;
dma_addr_t addr;
+ size_t size = cursor.size;
+ phys_addr_t phys = cursor.start + adev->gmc.aper_base;
- ++node;
addr = dma_map_resource(dev, phys, size, dir,
DMA_ATTR_SKIP_CPU_SYNC);
r = dma_mapping_error(dev, addr);
@@ -615,7 +624,10 @@ int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev,
sg_set_page(sg, NULL, size, 0);
sg_dma_address(sg) = addr;
sg_dma_len(sg) = size;
+
+ amdgpu_res_next(&cursor, cursor.size);
}
+
return 0;
error_unmap:
--
2.30.0
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