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 tzimmermann@suse.de Reviewed-by: Christian König christian.koenig@amd.com Acked-by: Daniel Vetter daniel.vetter@ffwll.ch Tested-by: Sam Ravnborg sam@ravnborg.org --- drivers/gpu/drm/drm_gem_ttm_helper.c | 38 +++++++++++++++ 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, 164 insertions(+)
diff --git a/drivers/gpu/drm/drm_gem_ttm_helper.c b/drivers/gpu/drm/drm_gem_ttm_helper.c index 0e4fb9ba43ad..db4c14d78a30 100644 --- a/drivers/gpu/drm/drm_gem_ttm_helper.c +++ b/drivers/gpu/drm/drm_gem_ttm_helper.c @@ -49,6 +49,44 @@ 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 <drm/ttm/ttm_bo_driver.h> #include <drm/ttm/ttm_placement.h> #include <drm/drm_vma_manager.h> +#include <linux/dma-buf-map.h> #include <linux/io.h> #include <linux/highmem.h> #include <linux/wait.h> @@ -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 <drm/ttm/ttm_bo_api.h> #include <drm/ttm/ttm_bo_driver.h>
+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 37102e45e496..2c59a785374c 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; @@ -494,6 +496,32 @@ 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