From 2b5b95b1ff3d70a95013a45e3b5b90f1daf42348 Mon Sep 17 00:00:00 2001 From: Christian König Date: Mon, 14 Sep 2020 15:09:33 +0200 Subject: mm: introduce vma_set_file function v4 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add the new vma_set_file() function to allow changing vma->vm_file with the necessary refcount dance. v2: add more users of this. v3: add missing EXPORT_SYMBOL, rebase on mmap cleanup, add comments why we drop the reference on two occasions. v4: make it clear that changing an anonymous vma is illegal. Signed-off-by: Christian König Reviewed-by: Daniel Vetter (v2) Reviewed-by: Jason Gunthorpe Link: https://patchwork.freedesktop.org/patch/394773/ --- include/linux/mm.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/mm.h b/include/linux/mm.h index ef360fe70aaf..2b7ac36c42dd 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2719,6 +2719,8 @@ static inline void vma_set_page_prot(struct vm_area_struct *vma) } #endif +void vma_set_file(struct vm_area_struct *vma, struct file *file); + #ifdef CONFIG_NUMA_BALANCING unsigned long change_prot_numa(struct vm_area_struct *vma, unsigned long start, unsigned long end); -- cgit v1.2.3 From e40b0b56ffdc16edce207904a7782da6a1a47162 Mon Sep 17 00:00:00 2001 From: Christian König Date: Thu, 5 Nov 2020 17:05:35 +0100 Subject: Revert "mm: introduce vma_set_file function v4" MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The kernel test robot is not happy with that. This reverts commit 2b5b95b1ff3d70a95013a45e3b5b90f1daf42348. Signed-off-by: Christian König Acked-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/394773/ --- drivers/dma-buf/dma-buf.c | 3 ++- drivers/gpu/drm/etnaviv/etnaviv_gem.c | 4 +++- drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 3 ++- drivers/gpu/drm/i915/gem/i915_gem_mman.c | 5 ++--- drivers/gpu/drm/msm/msm_gem.c | 4 +++- drivers/gpu/drm/omapdrm/omap_gem.c | 3 ++- drivers/gpu/drm/vgem/vgem_drv.c | 3 ++- drivers/staging/android/ashmem.c | 6 +++--- include/linux/mm.h | 2 -- mm/mmap.c | 12 ------------ 10 files changed, 19 insertions(+), 26 deletions(-) (limited to 'include/linux') diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index e63684d4cd90..282bd8b84170 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -1183,7 +1183,8 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, return -EINVAL; /* readjust the vma */ - vma_set_file(vma, dmabuf->file); + fput(vma->vm_file); + vma->vm_file = get_file(dmabuf->file); vma->vm_pgoff = pgoff; return dmabuf->ops->mmap(dmabuf, vma); diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c index 4132acfa11be..67d9a2b9ea6a 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c @@ -145,8 +145,10 @@ static int etnaviv_gem_mmap_obj(struct etnaviv_gem_object *etnaviv_obj, * address_space (so unmap_mapping_range does what we want, * in particular in the case of mmap'd dmabufs) */ + fput(vma->vm_file); + get_file(etnaviv_obj->base.filp); vma->vm_pgoff = 0; - vma_set_file(vma, etnaviv_obj->base.filp); + vma->vm_file = etnaviv_obj->base.filp; vma->vm_page_prot = vm_page_prot; } diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c index 04e9c04545ad..0dd477e56573 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c @@ -114,7 +114,8 @@ static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct * if (ret) return ret; - vma_set_file(vma, obj->base.filp); + fput(vma->vm_file); + vma->vm_file = get_file(obj->base.filp); return 0; } diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c index ec28a6cde49b..3d69e51f3e4d 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c @@ -893,9 +893,8 @@ int i915_gem_mmap(struct file *filp, struct vm_area_struct *vma) * requires avoiding extraneous references to their filp, hence why * we prefer to use an anonymous file for their mmaps. */ - vma_set_file(vma, anon); - /* Drop the initial creation reference, the vma is now holding one. */ - fput(anon); + fput(vma->vm_file); + vma->vm_file = anon; switch (mmo->mmap_type) { case I915_MMAP_TYPE_WC: diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c index 311721ceee50..2e1bce7c0b19 100644 --- a/drivers/gpu/drm/msm/msm_gem.c +++ b/drivers/gpu/drm/msm/msm_gem.c @@ -212,8 +212,10 @@ int msm_gem_mmap_obj(struct drm_gem_object *obj, * address_space (so unmap_mapping_range does what we want, * in particular in the case of mmap'd dmabufs) */ + fput(vma->vm_file); + get_file(obj->filp); vma->vm_pgoff = 0; - vma_set_file(vma, obj->filp); + vma->vm_file = obj->filp; vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); } diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c index f063f5a04fb0..d8e09792793a 100644 --- a/drivers/gpu/drm/omapdrm/omap_gem.c +++ b/drivers/gpu/drm/omapdrm/omap_gem.c @@ -564,8 +564,9 @@ int omap_gem_mmap_obj(struct drm_gem_object *obj, * address_space (so unmap_mapping_range does what we want, * in particular in the case of mmap'd dmabufs) */ + fput(vma->vm_file); vma->vm_pgoff = 0; - vma_set_file(vma, obj->filp); + vma->vm_file = get_file(obj->filp); vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); } diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c index ea0eecae5153..fa54a6d1403d 100644 --- a/drivers/gpu/drm/vgem/vgem_drv.c +++ b/drivers/gpu/drm/vgem/vgem_drv.c @@ -397,7 +397,8 @@ static int vgem_prime_mmap(struct drm_gem_object *obj, if (ret) return ret; - vma_set_file(vma, obj->filp); + fput(vma->vm_file); + vma->vm_file = get_file(obj->filp); vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c index 4789d36ddfd3..10b4be1f3e78 100644 --- a/drivers/staging/android/ashmem.c +++ b/drivers/staging/android/ashmem.c @@ -450,9 +450,9 @@ static int ashmem_mmap(struct file *file, struct vm_area_struct *vma) vma_set_anonymous(vma); } - vma_set_file(vma, asma->file); - /* XXX: merge this with the get_file() above if possible */ - fput(asma->file); + if (vma->vm_file) + fput(vma->vm_file); + vma->vm_file = asma->file; out: mutex_unlock(&ashmem_mutex); diff --git a/include/linux/mm.h b/include/linux/mm.h index 2b7ac36c42dd..ef360fe70aaf 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2719,8 +2719,6 @@ static inline void vma_set_page_prot(struct vm_area_struct *vma) } #endif -void vma_set_file(struct vm_area_struct *vma, struct file *file); - #ifdef CONFIG_NUMA_BALANCING unsigned long change_prot_numa(struct vm_area_struct *vma, unsigned long start, unsigned long end); diff --git a/mm/mmap.c b/mm/mmap.c index b0093cc69240..30a4e8412a58 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -136,18 +136,6 @@ void vma_set_page_prot(struct vm_area_struct *vma) WRITE_ONCE(vma->vm_page_prot, vm_page_prot); } -/* - * Change backing file, only valid to use during initial VMA setup. - */ -void vma_set_file(struct vm_area_struct *vma, struct file *file) -{ - /* Changing an anonymous vma with this is illegal */ - get_file(file); - swap(vma->vm_file, file); - fput(file); -} -EXPORT_SYMBOL(vma_set_file); - /* * Requires inode->i_mapping->i_mmap_rwsem */ -- cgit v1.2.3 From 43676605f890b218e551f396a55dbaea7799acb4 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Tue, 3 Nov 2020 10:30:10 +0100 Subject: drm/ttm: Add vmap/vunmap to TTM and TTM GEM helpers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The new functions ttm_bo_{vmap,vunmap}() map and unmap a TTM BO in kernel address space. The mapping's address is returned as struct dma_buf_map. Each function is a simplified version of TTM's existing kmap code. Both functions respect the memory's location ani/or writecombine flags. On top TTM's functions, GEM TTM helpers got drm_gem_ttm_{vmap,vunmap}(), two helpers that convert a GEM object into the TTM BO and forward the call to TTM's vmap/vunmap. These helpers can be dropped into the rsp GEM object callbacks. v5: * use size_t for storing mapping size (Christian) * ignore premapped memory areas correctly in ttm_bo_vunmap() * rebase onto latest TTM interfaces (Christian) * remove BUG() from ttm_bo_vmap() (Christian) v4: * drop ttm_kmap_obj_to_dma_buf() in favor of vmap helpers (Daniel, Christian) Signed-off-by: Thomas Zimmermann Reviewed-by: Christian König Acked-by: Daniel Vetter Tested-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20201103093015.1063-6-tzimmermann@suse.de --- drivers/gpu/drm/drm_gem_ttm_helper.c | 37 ++++++++++++++++++ drivers/gpu/drm/ttm/ttm_bo_util.c | 72 ++++++++++++++++++++++++++++++++++++ include/drm/drm_gem_ttm_helper.h | 6 +++ include/drm/ttm/ttm_bo_api.h | 28 ++++++++++++++ include/linux/dma-buf-map.h | 20 ++++++++++ 5 files changed, 163 insertions(+) (limited to 'include/linux') diff --git a/drivers/gpu/drm/drm_gem_ttm_helper.c b/drivers/gpu/drm/drm_gem_ttm_helper.c index 0e4fb9ba43ad..de28720757af 100644 --- a/drivers/gpu/drm/drm_gem_ttm_helper.c +++ b/drivers/gpu/drm/drm_gem_ttm_helper.c @@ -49,6 +49,43 @@ void drm_gem_ttm_print_info(struct drm_printer *p, unsigned int indent, } EXPORT_SYMBOL(drm_gem_ttm_print_info); +/** + * drm_gem_ttm_vmap() - vmap &ttm_buffer_object + * @gem: GEM object. + * @map: [out] returns the dma-buf mapping. + * + * Maps a GEM object with ttm_bo_vmap(). This function can be used as + * &drm_gem_object_funcs.vmap callback. + * + * Returns: + * 0 on success, or a negative errno code otherwise. + */ +int drm_gem_ttm_vmap(struct drm_gem_object *gem, + struct dma_buf_map *map) +{ + struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem); + + return ttm_bo_vmap(bo, map); +} +EXPORT_SYMBOL(drm_gem_ttm_vmap); + +/** + * drm_gem_ttm_vunmap() - vunmap &ttm_buffer_object + * @gem: GEM object. + * @map: dma-buf mapping. + * + * Unmaps a GEM object with ttm_bo_vunmap(). This function can be used as + * &drm_gem_object_funcs.vmap callback. + */ +void drm_gem_ttm_vunmap(struct drm_gem_object *gem, + struct dma_buf_map *map) +{ + struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem); + + ttm_bo_vunmap(bo, map); +} +EXPORT_SYMBOL(drm_gem_ttm_vunmap); + /** * drm_gem_ttm_mmap() - mmap &ttm_buffer_object * @gem: GEM object. diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c index ecb54415d1ca..7ccb2295cac1 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_util.c +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include @@ -471,6 +472,77 @@ void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map) } EXPORT_SYMBOL(ttm_bo_kunmap); +int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map) +{ + struct ttm_resource *mem = &bo->mem; + int ret; + + ret = ttm_mem_io_reserve(bo->bdev, mem); + if (ret) + return ret; + + if (mem->bus.is_iomem) { + void __iomem *vaddr_iomem; + size_t size = bo->num_pages << PAGE_SHIFT; + + if (mem->bus.addr) + vaddr_iomem = (void __iomem *)mem->bus.addr; + else if (mem->bus.caching == ttm_write_combined) + vaddr_iomem = ioremap_wc(mem->bus.offset, size); + else + vaddr_iomem = ioremap(mem->bus.offset, size); + + if (!vaddr_iomem) + return -ENOMEM; + + dma_buf_map_set_vaddr_iomem(map, vaddr_iomem); + + } else { + struct ttm_operation_ctx ctx = { + .interruptible = false, + .no_wait_gpu = false + }; + struct ttm_tt *ttm = bo->ttm; + pgprot_t prot; + void *vaddr; + + ret = ttm_tt_populate(bo->bdev, ttm, &ctx); + if (ret) + return ret; + + /* + * We need to use vmap to get the desired page protection + * or to make the buffer object look contiguous. + */ + prot = ttm_io_prot(bo, mem, PAGE_KERNEL); + vaddr = vmap(ttm->pages, bo->num_pages, 0, prot); + if (!vaddr) + return -ENOMEM; + + dma_buf_map_set_vaddr(map, vaddr); + } + + return 0; +} +EXPORT_SYMBOL(ttm_bo_vmap); + +void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map) +{ + struct ttm_resource *mem = &bo->mem; + + if (dma_buf_map_is_null(map)) + return; + + if (!map->is_iomem) + vunmap(map->vaddr); + else if (!mem->bus.addr) + iounmap(map->vaddr_iomem); + dma_buf_map_clear(map); + + ttm_mem_io_free(bo->bdev, &bo->mem); +} +EXPORT_SYMBOL(ttm_bo_vunmap); + static int ttm_bo_wait_free_node(struct ttm_buffer_object *bo, bool dst_use_tt) { diff --git a/include/drm/drm_gem_ttm_helper.h b/include/drm/drm_gem_ttm_helper.h index 118cef76f84f..7c6d874910b8 100644 --- a/include/drm/drm_gem_ttm_helper.h +++ b/include/drm/drm_gem_ttm_helper.h @@ -10,11 +10,17 @@ #include #include +struct dma_buf_map; + #define drm_gem_ttm_of_gem(gem_obj) \ container_of(gem_obj, struct ttm_buffer_object, base) void drm_gem_ttm_print_info(struct drm_printer *p, unsigned int indent, const struct drm_gem_object *gem); +int drm_gem_ttm_vmap(struct drm_gem_object *gem, + struct dma_buf_map *map); +void drm_gem_ttm_vunmap(struct drm_gem_object *gem, + struct dma_buf_map *map); int drm_gem_ttm_mmap(struct drm_gem_object *gem, struct vm_area_struct *vma); diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index 5ddad88ae6ed..2564e66e67d7 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -48,6 +48,8 @@ struct ttm_bo_global; struct ttm_bo_device; +struct dma_buf_map; + struct drm_mm_node; struct ttm_placement; @@ -495,6 +497,32 @@ int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page, */ void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map); +/** + * ttm_bo_vmap + * + * @bo: The buffer object. + * @map: pointer to a struct dma_buf_map representing the map. + * + * Sets up a kernel virtual mapping, using ioremap or vmap to the + * data in the buffer object. The parameter @map returns the virtual + * address as struct dma_buf_map. Unmap the buffer with ttm_bo_vunmap(). + * + * Returns + * -ENOMEM: Out of memory. + * -EINVAL: Invalid range. + */ +int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map); + +/** + * ttm_bo_vunmap + * + * @bo: The buffer object. + * @map: Object describing the map to unmap. + * + * Unmaps a kernel map set up by ttm_bo_vmap(). + */ +void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map); + /** * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object. * diff --git a/include/linux/dma-buf-map.h b/include/linux/dma-buf-map.h index fd1aba545fdf..2e8bbecb5091 100644 --- a/include/linux/dma-buf-map.h +++ b/include/linux/dma-buf-map.h @@ -45,6 +45,12 @@ * * dma_buf_map_set_vaddr(&map. 0xdeadbeaf); * + * To set an address in I/O memory, use dma_buf_map_set_vaddr_iomem(). + * + * .. code-block:: c + * + * dma_buf_map_set_vaddr_iomem(&map. 0xdeadbeaf); + * * Test if a mapping is valid with either dma_buf_map_is_set() or * dma_buf_map_is_null(). * @@ -118,6 +124,20 @@ static inline void dma_buf_map_set_vaddr(struct dma_buf_map *map, void *vaddr) map->is_iomem = false; } +/** + * dma_buf_map_set_vaddr_iomem - Sets a dma-buf mapping structure to an address in I/O memory + * @map: The dma-buf mapping structure + * @vaddr_iomem: An I/O-memory address + * + * Sets the address and the I/O-memory flag. + */ +static inline void dma_buf_map_set_vaddr_iomem(struct dma_buf_map *map, + void __iomem *vaddr_iomem) +{ + map->vaddr_iomem = vaddr_iomem; + map->is_iomem = true; +} + /** * dma_buf_map_is_equal - Compares two dma-buf mapping structures for equality * @lhs: The dma-buf mapping structure -- cgit v1.2.3 From b4e7090c242ec64bfa77a69ea7c3cceba21c7a65 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Tue, 3 Nov 2020 10:30:14 +0100 Subject: dma-buf-map: Add memcpy and pointer-increment interfaces To do framebuffer updates, one needs memcpy from system memory and a pointer-increment function. Add both interfaces with documentation. v5: * include to build on sparc64 (Sam) Signed-off-by: Thomas Zimmermann Reviewed-by: Sam Ravnborg Tested-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20201103093015.1063-10-tzimmermann@suse.de --- include/linux/dma-buf-map.h | 73 ++++++++++++++++++++++++++++++++++++++------- 1 file changed, 63 insertions(+), 10 deletions(-) (limited to 'include/linux') diff --git a/include/linux/dma-buf-map.h b/include/linux/dma-buf-map.h index 2e8bbecb5091..583a3a1f9447 100644 --- a/include/linux/dma-buf-map.h +++ b/include/linux/dma-buf-map.h @@ -7,6 +7,7 @@ #define __DMA_BUF_MAP_H__ #include +#include /** * DOC: overview @@ -32,6 +33,14 @@ * accessing the buffer. Use the returned instance and the helper functions * to access the buffer's memory in the correct way. * + * The type :c:type:`struct dma_buf_map ` and its helpers are + * actually independent from the dma-buf infrastructure. When sharing buffers + * among devices, drivers have to know the location of the memory to access + * the buffers in a safe way. :c:type:`struct dma_buf_map ` + * solves this problem for dma-buf and its users. If other drivers or + * sub-systems require similar functionality, the type could be generalized + * and moved to a more prominent header file. + * * Open-coding access to :c:type:`struct dma_buf_map ` is * considered bad style. Rather then accessing its fields directly, use one * of the provided helper functions, or implement your own. For example, @@ -51,6 +60,14 @@ * * dma_buf_map_set_vaddr_iomem(&map. 0xdeadbeaf); * + * Instances of struct dma_buf_map do not have to be cleaned up, but + * can be cleared to NULL with dma_buf_map_clear(). Cleared mappings + * always refer to system memory. + * + * .. code-block:: c + * + * dma_buf_map_clear(&map); + * * Test if a mapping is valid with either dma_buf_map_is_set() or * dma_buf_map_is_null(). * @@ -73,17 +90,19 @@ * if (dma_buf_map_is_equal(&sys_map, &io_map)) * // always false * - * Instances of struct dma_buf_map do not have to be cleaned up, but - * can be cleared to NULL with dma_buf_map_clear(). Cleared mappings - * always refer to system memory. + * A set up instance of struct dma_buf_map can be used to access or manipulate + * the buffer memory. Depending on the location of the memory, the provided + * helpers will pick the correct operations. Data can be copied into the memory + * with dma_buf_map_memcpy_to(). The address can be manipulated with + * dma_buf_map_incr(). * - * The type :c:type:`struct dma_buf_map ` and its helpers are - * actually independent from the dma-buf infrastructure. When sharing buffers - * among devices, drivers have to know the location of the memory to access - * the buffers in a safe way. :c:type:`struct dma_buf_map ` - * solves this problem for dma-buf and its users. If other drivers or - * sub-systems require similar functionality, the type could be generalized - * and moved to a more prominent header file. + * .. code-block:: c + * + * const void *src = ...; // source buffer + * size_t len = ...; // length of src + * + * dma_buf_map_memcpy_to(&map, src, len); + * dma_buf_map_incr(&map, len); // go to first byte after the memcpy */ /** @@ -210,4 +229,38 @@ static inline void dma_buf_map_clear(struct dma_buf_map *map) } } +/** + * dma_buf_map_memcpy_to - Memcpy into dma-buf mapping + * @dst: The dma-buf mapping structure + * @src: The source buffer + * @len: The number of byte in src + * + * Copies data into a dma-buf mapping. The source buffer is in system + * memory. Depending on the buffer's location, the helper picks the correct + * method of accessing the memory. + */ +static inline void dma_buf_map_memcpy_to(struct dma_buf_map *dst, const void *src, size_t len) +{ + if (dst->is_iomem) + memcpy_toio(dst->vaddr_iomem, src, len); + else + memcpy(dst->vaddr, src, len); +} + +/** + * dma_buf_map_incr - Increments the address stored in a dma-buf mapping + * @map: The dma-buf mapping structure + * @incr: The number of bytes to increment + * + * Increments the address stored in a dma-buf mapping. Depending on the + * buffer's location, the correct value will be updated. + */ +static inline void dma_buf_map_incr(struct dma_buf_map *map, size_t incr) +{ + if (map->is_iomem) + map->vaddr_iomem += incr; + else + map->vaddr += incr; +} + #endif /* __DMA_BUF_MAP_H__ */ -- cgit v1.2.3 From 476b485be03c37212fcf10d85510aae5d34316ef Mon Sep 17 00:00:00 2001 From: Jianxin Xiong Date: Tue, 10 Nov 2020 13:41:17 -0800 Subject: dma-buf: Document that dma-buf size is fixed The fact that the size of dma-buf is invariant over the lifetime of the buffer is mentioned in the comment of 'dma_buf_ops.mmap', but is not documented at where the info is defined. Add the missing documentation. Signed-off-by: Jianxin Xiong Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/1605044477-51833-7-git-send-email-jianxin.xiong@intel.com --- include/linux/dma-buf.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 03875eaed51a..cf72699cb2bc 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -273,7 +273,7 @@ struct dma_buf_ops { /** * struct dma_buf - shared buffer object - * @size: size of the buffer + * @size: size of the buffer; invariant over the lifetime of the buffer. * @file: file pointer used for sharing buffers across, and for refcounting. * @attachments: list of dma_buf_attachment that denotes all devices attached, * protected by dma_resv lock. @@ -405,7 +405,7 @@ struct dma_buf_attachment { * @exp_name: name of the exporter - useful for debugging. * @owner: pointer to exporter module - used for refcounting kernel module * @ops: Attach allocator-defined dma buf ops to the new buffer - * @size: Size of the buffer + * @size: Size of the buffer - invariant over the lifetime of the buffer * @flags: mode flags for the file * @resv: reservation-object, NULL to allocate default one * @priv: Attach private data of allocator to this buffer -- cgit v1.2.3