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| author | Shixiong Ou <oushixiong@kylinos.cn> | 2025-05-22 10:07:12 +0300 |
|---|---|---|
| committer | Thomas Zimmermann <tzimmermann@suse.de> | 2025-06-03 10:21:01 +0300 |
| commit | 660cd44659a05c5fbfce6d2bb1ce448aa0f35594 (patch) | |
| tree | 0f69608e085745b2ee892d02e7b5de63621ef372 /include/drm | |
| parent | 6048f5587614bb4919c54966913452c1a0a43138 (diff) | |
| download | linux-660cd44659a05c5fbfce6d2bb1ce448aa0f35594.tar.xz | |
drm/shmem-helper: Import dmabuf without mapping its sg_table
[WHY]
1. Drivers using DRM_GEM_SHADOW_PLANE_HELPER_FUNCS and
DRM_GEM_SHMEM_DRIVER_OPS (e.g., udl, ast) do not require
sg_table import.
They only need dma_buf_vmap() to access the shared buffer's
kernel virtual address.
2. On certain Aspeed-based boards, a dma_mask of 0xffff_ffff may
trigger SWIOTLB during dmabuf import. However, IO_TLB_SEGSIZE
restricts the maximum DMA streaming mapping memory, resulting in
errors like:
ast 0000:07:00.0: swiotlb buffer is full (sz: 3145728 bytes), total 32768 (slots), used 0 (slots)
[HOW]
Provide a gem_prime_import implementation without sg_table mapping
to avoid issues (e.g., "swiotlb buffer is full"). Drivers that do not
require sg_table can adopt this.
Signed-off-by: Shixiong Ou <oushixiong@kylinos.cn>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20250522070714.439824-1-oushixiong1025@163.com
Diffstat (limited to 'include/drm')
| -rw-r--r-- | include/drm/drm_gem_shmem_helper.h | 15 | ||||
| -rw-r--r-- | include/drm/drm_prime.h | 3 |
2 files changed, 18 insertions, 0 deletions
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h index b4f993da3cae..35f7466dca84 100644 --- a/include/drm/drm_gem_shmem_helper.h +++ b/include/drm/drm_gem_shmem_helper.h @@ -287,6 +287,8 @@ drm_gem_shmem_prime_import_sg_table(struct drm_device *dev, struct sg_table *sgt); int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev, struct drm_mode_create_dumb *args); +struct drm_gem_object *drm_gem_shmem_prime_import_no_map(struct drm_device *dev, + struct dma_buf *buf); /** * DRM_GEM_SHMEM_DRIVER_OPS - Default shmem GEM operations @@ -298,4 +300,17 @@ int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev, .gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table, \ .dumb_create = drm_gem_shmem_dumb_create +/** + * DRM_GEM_SHMEM_DRIVER_OPS_NO_MAP_SGT - shmem GEM operations + * without mapping sg_table on + * imported buffer. + * + * This macro provides a shortcut for setting the shmem GEM operations in + * the &drm_driver structure for drivers that do not require a sg_table on + * imported buffers. + */ +#define DRM_GEM_SHMEM_DRIVER_OPS_NO_MAP_SGT \ + .gem_prime_import = drm_gem_shmem_prime_import_no_map, \ + .dumb_create = drm_gem_shmem_dumb_create + #endif /* __DRM_GEM_SHMEM_HELPER_H__ */ diff --git a/include/drm/drm_prime.h b/include/drm/drm_prime.h index fa085c44d4ca..f50f862f0d8b 100644 --- a/include/drm/drm_prime.h +++ b/include/drm/drm_prime.h @@ -100,6 +100,9 @@ struct dma_buf *drm_gem_prime_export(struct drm_gem_object *obj, unsigned long drm_prime_get_contiguous_size(struct sg_table *sgt); /* helper functions for importing */ +bool drm_gem_is_prime_exported_dma_buf(struct drm_device *dev, + struct dma_buf *dma_buf); + struct drm_gem_object *drm_gem_prime_import_dev(struct drm_device *dev, struct dma_buf *dma_buf, struct device *attach_dev); |