kernel/linux.git/include/drm/drm_prime.h, branch v6.19.11

drm/shmem-helper: Import dmabuf without mapping its sg_table

2025-06-03T07:21:01+00:00

[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 Acked-by: Thomas Zimmermann Signed-off-by: Thomas Zimmermann Link: https://lore.kernel.org/r/20250522070714.439824-1-oushixiong1025@163.com

drm: new helper: drm_gem_prime_handle_to_dmabuf()

2024-09-10T17:44:30+00:00

Once something had been put into descriptor table, the only thing you can do with it is returning descriptor to userland - you can't withdraw it on subsequent failure exit, etc. You certainly can't count upon it staying in the same slot of descriptor table - another thread could've played with close(2)/dup2(2)/whatnot. drm_gem_prime_handle_to_fd() creates a dmabuf, allocates a descriptor and attaches dmabuf's file to it (the last two steps are done in dma_buf_fd()). That's nice when all you are going to do is passing a descriptor to userland. If you just need to work with the resulting object or have something else to be done that might fail, drm_gem_prime_handle_to_fd() is racy. The problem is analogous to one with anon_inode_getfd(), and solution is similar to what anon_inode_getfile() provides. Add drm_gem_prime_handle_to_dmabuf() - the "set dmabuf up" parts of drm_gem_prime_handle_to_fd() without the descriptor-related ones. Instead of inserting into descriptor table and returning the file descriptor it just returns the struct file. drm_gem_prime_handle_to_fd() becomes a wrapper for it. Other users will be introduced in the next commit. Acked-by: Thomas Zimmermann Signed-off-by: Al Viro Signed-off-by: Alex Deucher

Revert "drm/prime: Unexport helpers for fd/handle conversion"

2023-11-30T19:46:04+00:00

This reverts commit 71a7974ac7019afeec105a54447ae1dc7216cbb3. These helper functions are needed for KFD to export and import DMABufs the right way without duplicating the tracking of DMABufs associated with GEM objects while ensuring that move notifier callbacks are working as intended. CC: Christian König CC: Thomas Zimmermann Acked-by: Thomas Zimmermann Acked-by: Daniel Vetter Signed-off-by: Felix Kuehling Signed-off-by: Alex Deucher

drm/prime: Unexport helpers for fd/handle conversion

2023-06-26T09:08:46+00:00

Unexport drm_gem_prime_fd_to_handle() and drm_gem_prime_handle_to_fd(). Both are only used internally within the PRIME code. v2: * reword docs as functions are now unexported (Simon) Signed-off-by: Thomas Zimmermann Reviewed-by: Simon Ser Acked-by: Alex Deucher Reviewed-by: Jeffrey Hugo Link: https://patchwork.freedesktop.org/patch/msgid/20230620080252.16368-4-tzimmermann@suse.de

dma-buf-map: Rename to iosys-map

2022-02-08T00:35:35+00:00

Rename struct dma_buf_map to struct iosys_map and corresponding APIs. Over time dma-buf-map grew up to more functionality than the one used by dma-buf: in fact it's just a shim layer to abstract system memory, that can be accessed via regular load and store, from IO memory that needs to be acessed via arch helpers. The idea is to extend this API so it can fulfill other needs, internal to a single driver. Example: in the i915 driver it's desired to share the implementation for integrated graphics, which uses mostly system memory, with discrete graphics, which may need to access IO memory. The conversion was mostly done with the following semantic patch: @r1@ @@ - struct dma_buf_map + struct iosys_map @r2@ @@ ( - DMA_BUF_MAP_INIT_VADDR + IOSYS_MAP_INIT_VADDR | - dma_buf_map_set_vaddr + iosys_map_set_vaddr | - dma_buf_map_set_vaddr_iomem + iosys_map_set_vaddr_iomem | - dma_buf_map_is_equal + iosys_map_is_equal | - dma_buf_map_is_null + iosys_map_is_null | - dma_buf_map_is_set + iosys_map_is_set | - dma_buf_map_clear + iosys_map_clear | - dma_buf_map_memcpy_to + iosys_map_memcpy_to | - dma_buf_map_incr + iosys_map_incr ) @@ @@ - #include + #include Then some files had their includes adjusted and some comments were update to remove mentions to dma-buf-map. Since this is not specific to dma-buf anymore, move the documentation to the "Bus-Independent Device Accesses" section. v2: - Squash patches v3: - Fix wrong removal of dma-buf.h from MAINTAINERS - Move documentation from dma-buf.rst to device-io.rst v4: - Change documentation title and level Signed-off-by: Lucas De Marchi Acked-by: Christian König Acked-by: Sumit Semwal Acked-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com

drm/prime: split array import functions v4

2020-11-30T14:00:45+00:00

Mapping the imported pages of a DMA-buf into an userspace process doesn't work as expected. But we have reoccurring requests on this approach, so split the functions for this and document that dma_buf_mmap() needs to be used instead. v2: split it into two functions v3: rebased on latest changes v4: update commit message a bit Signed-off-by: Christian König Acked-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/403838/

Merge drm/drm-next into drm-misc-next

2020-11-02T10:17:54+00:00

Daniel needs -rc2 in drm-misc-next to merge some patches Signed-off-by: Maxime Ripard

dma-buf: Use struct dma_buf_map in dma_buf_vunmap() interfaces

2020-09-29T10:41:21+00:00

This patch updates dma_buf_vunmap() and dma-buf's vunmap callback to use struct dma_buf_map. The interfaces used to receive a buffer address. This address is now given in an instance of the structure. Users of the functions are updated accordingly. This is only an interface change. It is currently expected that dma-buf memory can be accessed with system memory load/store operations. v2: * include dma-buf-heaps and i915 selftests (kernel test robot) * initialize cma_obj before using it in drm_gem_cma_free_object() (kernel test robot) Signed-off-by: Thomas Zimmermann Acked-by: Sumit Semwal Acked-by: Christian König Acked-by: Daniel Vetter Acked-by: Tomasz Figa Acked-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20200925115601.23955-4-tzimmermann@suse.de

dma-buf: Use struct dma_buf_map in dma_buf_vmap() interfaces

2020-09-29T10:40:58+00:00

This patch updates dma_buf_vmap() and dma-buf's vmap callback to use struct dma_buf_map. The interfaces used to return a buffer address. This address now gets stored in an instance of the structure that is given as an additional argument. The functions return an errno code on errors. Users of the functions are updated accordingly. This is only an interface change. It is currently expected that dma-buf memory can be accessed with system memory load/store operations. v3: * update fastrpc driver (kernel test robot) v2: * always clear map parameter in dma_buf_vmap() (Daniel) * include dma-buf-heaps and i915 selftests (kernel test robot) Signed-off-by: Thomas Zimmermann Acked-by: Sumit Semwal Acked-by: Christian König Acked-by: Daniel Vetter Acked-by: Tomasz Figa Acked-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20200925115601.23955-3-tzimmermann@suse.de

Merge tag 'drm-misc-next-2020-09-21' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

2020-09-22T23:52:24+00:00

drm-misc-next for 5.10: UAPI Changes: Cross-subsystem Changes: - virtio: Merged a PR for patches that will affect drm/virtio Core Changes: - dev: More devm_drm convertions and removal of drm_dev_init - atomic: Split out drm_atomic_helper_calc_timestamping_constants of drm_atomic_helper_update_legacy_modeset_state - ttm: More rework Driver Changes: - i915: selftests improvements - panfrost: support for Amlogic SoC - vc4: one fix - tree-wide: conversions to devm_drm_dev_alloc, - ast: simplifications of the atomic modesetting code - panfrost: multiple fixes - vc4: multiple fixes Signed-off-by: Dave Airlie From: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20200921152956.2gxnsdgxmwhvjyut@gilmour.lan