dma-buf-map: Rename to iosys-map

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 <linux/dma-buf-map.h>
	+ #include <linux/iosys-map.h>

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 <lucas.demarchi@intel.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com

16 files changed, 316 insertions, 317 deletions

diff --git a/include/drm/drm_cache.h b/include/drm/drm_cache.h
index cc9de1632dd3..22deb216b59c 100644
--- a/include/drm/drm_cache.h
+++ b/include/drm/drm_cache.h
@@ -35,7 +35,7 @@
 
 #include <linux/scatterlist.h>
 
-struct dma_buf_map;
+struct iosys_map;
 
 void drm_clflush_pages(struct page *pages[], unsigned long num_pages);
 void drm_clflush_sg(struct sg_table *st);
@@ -74,7 +74,7 @@ static inline bool drm_arch_can_wc_memory(void)
 
 void drm_memcpy_init_early(void);
 
-void drm_memcpy_from_wc(struct dma_buf_map *dst,
-			const struct dma_buf_map *src,
+void drm_memcpy_from_wc(struct iosys_map *dst,
+			const struct iosys_map *src,
 			unsigned long len);
 #endif
diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
index f07f2fb02e75..4fc8018eddda 100644
--- a/include/drm/drm_client.h
+++ b/include/drm/drm_client.h
@@ -3,7 +3,7 @@
 #ifndef _DRM_CLIENT_H_
 #define _DRM_CLIENT_H_
 
-#include <linux/dma-buf-map.h>
+#include <linux/iosys-map.h>
 #include <linux/lockdep.h>
 #include <linux/mutex.h>
 #include <linux/types.h>
@@ -144,7 +144,7 @@ struct drm_client_buffer {
 	/**
 	 * @map: Virtual address for the buffer
 	 */
-	struct dma_buf_map map;
+	struct iosys_map map;
 
 	/**
 	 * @fb: DRM framebuffer
@@ -156,7 +156,8 @@ struct drm_client_buffer *
 drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format);
 void drm_client_framebuffer_delete(struct drm_client_buffer *buffer);
 int drm_client_framebuffer_flush(struct drm_client_buffer *buffer, struct drm_rect *rect);
-int drm_client_buffer_vmap(struct drm_client_buffer *buffer, struct dma_buf_map *map);
+int drm_client_buffer_vmap(struct drm_client_buffer *buffer,
+			   struct iosys_map *map);
 void drm_client_buffer_vunmap(struct drm_client_buffer *buffer);
 
 int drm_client_modeset_create(struct drm_client_dev *client);
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 35e7f44c2a75..e2941cee14b6 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -39,7 +39,7 @@
 
 #include <drm/drm_vma_manager.h>
 
-struct dma_buf_map;
+struct iosys_map;
 struct drm_gem_object;
 
 /**
@@ -139,7 +139,7 @@ struct drm_gem_object_funcs {
 	 *
 	 * This callback is optional.
 	 */
-	int (*vmap)(struct drm_gem_object *obj, struct dma_buf_map *map);
+	int (*vmap)(struct drm_gem_object *obj, struct iosys_map *map);
 
 	/**
 	 * @vunmap:
@@ -149,7 +149,7 @@ struct drm_gem_object_funcs {
 	 *
 	 * This callback is optional.
 	 */
-	void (*vunmap)(struct drm_gem_object *obj, struct dma_buf_map *map);
+	void (*vunmap)(struct drm_gem_object *obj, struct iosys_map *map);
 
 	/**
 	 * @mmap:
diff --git a/include/drm/drm_gem_atomic_helper.h b/include/drm/drm_gem_atomic_helper.h
index 0b1e2dd2ac3f..6e3319e9001a 100644
--- a/include/drm/drm_gem_atomic_helper.h
+++ b/include/drm/drm_gem_atomic_helper.h
@@ -3,7 +3,7 @@
 #ifndef __DRM_GEM_ATOMIC_HELPER_H__
 #define __DRM_GEM_ATOMIC_HELPER_H__
 
-#include <linux/dma-buf-map.h>
+#include <linux/iosys-map.h>
 
 #include <drm/drm_fourcc.h>
 #include <drm/drm_plane.h>
@@ -59,7 +59,7 @@ struct drm_shadow_plane_state {
 	 * The memory mappings stored in map should be established in the plane's
 	 * prepare_fb callback and removed in the cleanup_fb callback.
 	 */
-	struct dma_buf_map map[DRM_FORMAT_MAX_PLANES];
+	struct iosys_map map[DRM_FORMAT_MAX_PLANES];
 
 	/**
 	 * @data: Address of each framebuffer BO's data
@@ -67,7 +67,7 @@ struct drm_shadow_plane_state {
 	 * The address of the data stored in each mapping. This is different
 	 * for framebuffers with non-zero offset fields.
 	 */
-	struct dma_buf_map data[DRM_FORMAT_MAX_PLANES];
+	struct iosys_map data[DRM_FORMAT_MAX_PLANES];
 };
 
 /**
diff --git a/include/drm/drm_gem_cma_helper.h b/include/drm/drm_gem_cma_helper.h
index adb507a9dbf0..fbda4ce5d5fb 100644
--- a/include/drm/drm_gem_cma_helper.h
+++ b/include/drm/drm_gem_cma_helper.h
@@ -38,7 +38,8 @@ void drm_gem_cma_free(struct drm_gem_cma_object *cma_obj);
 void drm_gem_cma_print_info(const struct drm_gem_cma_object *cma_obj,
 			    struct drm_printer *p, unsigned int indent);
 struct sg_table *drm_gem_cma_get_sg_table(struct drm_gem_cma_object *cma_obj);
-int drm_gem_cma_vmap(struct drm_gem_cma_object *cma_obj, struct dma_buf_map *map);
+int drm_gem_cma_vmap(struct drm_gem_cma_object *cma_obj,
+		     struct iosys_map *map);
 int drm_gem_cma_mmap(struct drm_gem_cma_object *cma_obj, struct vm_area_struct *vma);
 
 extern const struct vm_operations_struct drm_gem_cma_vm_ops;
@@ -106,7 +107,8 @@ static inline struct sg_table *drm_gem_cma_object_get_sg_table(struct drm_gem_ob
  * Returns:
  * 0 on success or a negative error code on failure.
  */
-static inline int drm_gem_cma_object_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
+static inline int drm_gem_cma_object_vmap(struct drm_gem_object *obj,
+					  struct iosys_map *map)
 {
 	struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);
 
diff --git a/include/drm/drm_gem_framebuffer_helper.h b/include/drm/drm_gem_framebuffer_helper.h
index 905727719ead..1091e4fa08cb 100644
--- a/include/drm/drm_gem_framebuffer_helper.h
+++ b/include/drm/drm_gem_framebuffer_helper.h
@@ -2,7 +2,7 @@
 #define __DRM_GEM_FB_HELPER_H__
 
 #include <linux/dma-buf.h>
-#include <linux/dma-buf-map.h>
+#include <linux/iosys-map.h>
 
 #include <drm/drm_fourcc.h>
 
@@ -40,10 +40,10 @@ drm_gem_fb_create_with_dirty(struct drm_device *dev, struct drm_file *file,
 			     const struct drm_mode_fb_cmd2 *mode_cmd);
 
 int drm_gem_fb_vmap(struct drm_framebuffer *fb,
-		    struct dma_buf_map map[static DRM_FORMAT_MAX_PLANES],
-		    struct dma_buf_map data[DRM_FORMAT_MAX_PLANES]);
+		    struct iosys_map map[static DRM_FORMAT_MAX_PLANES],
+		    struct iosys_map data[DRM_FORMAT_MAX_PLANES]);
 void drm_gem_fb_vunmap(struct drm_framebuffer *fb,
-		       struct dma_buf_map map[static DRM_FORMAT_MAX_PLANES]);
+		       struct iosys_map map[static DRM_FORMAT_MAX_PLANES]);
 int drm_gem_fb_begin_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir);
 void drm_gem_fb_end_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir);
 
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index 311d66c9cf4b..68347b63fc71 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -113,8 +113,10 @@ int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem);
 void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem);
 int drm_gem_shmem_pin(struct drm_gem_shmem_object *shmem);
 void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem);
-int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem, struct dma_buf_map *map);
-void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem, struct dma_buf_map *map);
+int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem,
+		       struct iosys_map *map);
+void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem,
+			  struct iosys_map *map);
 int drm_gem_shmem_mmap(struct drm_gem_shmem_object *shmem, struct vm_area_struct *vma);
 
 int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv);
@@ -226,7 +228,8 @@ static inline struct sg_table *drm_gem_shmem_object_get_sg_table(struct drm_gem_
  * Returns:
  * 0 on success or a negative error code on failure.
  */
-static inline int drm_gem_shmem_object_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
+static inline int drm_gem_shmem_object_vmap(struct drm_gem_object *obj,
+					    struct iosys_map *map)
 {
 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
 
@@ -241,7 +244,8 @@ static inline int drm_gem_shmem_object_vmap(struct drm_gem_object *obj, struct d
  * This function wraps drm_gem_shmem_vunmap(). Drivers that employ the shmem helpers should
  * use it as their &drm_gem_object_funcs.vunmap handler.
  */
-static inline void drm_gem_shmem_object_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map)
+static inline void drm_gem_shmem_object_vunmap(struct drm_gem_object *obj,
+					       struct iosys_map *map)
 {
 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
 
diff --git a/include/drm/drm_gem_ttm_helper.h b/include/drm/drm_gem_ttm_helper.h
index 78040f6cc6f3..4c003b4f173e 100644
--- a/include/drm/drm_gem_ttm_helper.h
+++ b/include/drm/drm_gem_ttm_helper.h
@@ -10,7 +10,7 @@
 #include <drm/ttm/ttm_bo_api.h>
 #include <drm/ttm/ttm_bo_driver.h>
 
-struct dma_buf_map;
+struct iosys_map;
 
 #define drm_gem_ttm_of_gem(gem_obj) \
 	container_of(gem_obj, struct ttm_buffer_object, base)
@@ -18,9 +18,9 @@ struct dma_buf_map;
 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);
+		     struct iosys_map *map);
 void drm_gem_ttm_vunmap(struct drm_gem_object *gem,
-			struct dma_buf_map *map);
+			struct iosys_map *map);
 int drm_gem_ttm_mmap(struct drm_gem_object *gem,
 		     struct vm_area_struct *vma);
 
diff --git a/include/drm/drm_gem_vram_helper.h b/include/drm/drm_gem_vram_helper.h
index b4ce27a72773..c083a1d71cf4 100644
--- a/include/drm/drm_gem_vram_helper.h
+++ b/include/drm/drm_gem_vram_helper.h
@@ -12,7 +12,7 @@
 #include <drm/ttm/ttm_bo_driver.h>
 
 #include <linux/container_of.h>
-#include <linux/dma-buf-map.h>
+#include <linux/iosys-map.h>
 
 struct drm_mode_create_dumb;
 struct drm_plane;
@@ -51,7 +51,7 @@ struct vm_area_struct;
  */
 struct drm_gem_vram_object {
 	struct ttm_buffer_object bo;
-	struct dma_buf_map map;
+	struct iosys_map map;
 
 	/**
 	 * @vmap_use_count:
@@ -97,8 +97,9 @@ void drm_gem_vram_put(struct drm_gem_vram_object *gbo);
 s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo);
 int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag);
 int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo);
-int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map);
-void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map);
+int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct iosys_map *map);
+void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo,
+			 struct iosys_map *map);
 
 int drm_gem_vram_fill_create_dumb(struct drm_file *file,
 				  struct drm_device *dev,
diff --git a/include/drm/drm_prime.h b/include/drm/drm_prime.h
index 54f2c58305d2..2a1d01e5b56b 100644
--- a/include/drm/drm_prime.h
+++ b/include/drm/drm_prime.h
@@ -54,7 +54,7 @@ struct device;
 struct dma_buf_export_info;
 struct dma_buf;
 struct dma_buf_attachment;
-struct dma_buf_map;
+struct iosys_map;
 
 enum dma_data_direction;
 
@@ -83,8 +83,8 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
 void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
 			   struct sg_table *sgt,
 			   enum dma_data_direction dir);
-int drm_gem_dmabuf_vmap(struct dma_buf *dma_buf, struct dma_buf_map *map);
-void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, struct dma_buf_map *map);
+int drm_gem_dmabuf_vmap(struct dma_buf *dma_buf, struct iosys_map *map);
+void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, struct iosys_map *map);
 
 int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
 int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma);
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index c17b2df9178b..155b19ee12fb 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -47,7 +47,7 @@ struct ttm_global;
 
 struct ttm_device;
 
-struct dma_buf_map;
+struct iosys_map;
 
 struct drm_mm_node;
 
@@ -481,17 +481,17 @@ 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.
+ * @map: pointer to a struct iosys_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().
+ * address as struct iosys_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);
+int ttm_bo_vmap(struct ttm_buffer_object *bo, struct iosys_map *map);
 
 /**
  * ttm_bo_vunmap
@@ -501,7 +501,7 @@ int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map);
  *
  * Unmaps a kernel map set up by ttm_bo_vmap().
  */
-void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map);
+void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct iosys_map *map);
 
 /**
  * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object.
diff --git a/include/drm/ttm/ttm_kmap_iter.h b/include/drm/ttm/ttm_kmap_iter.h
index 8bb00fd39d6c..cc5c09a211b4 100644
--- a/include/drm/ttm/ttm_kmap_iter.h
+++ b/include/drm/ttm/ttm_kmap_iter.h
@@ -8,7 +8,7 @@
 #include <linux/types.h>
 
 struct ttm_kmap_iter;
-struct dma_buf_map;
+struct iosys_map;
 
 /**
  * struct ttm_kmap_iter_ops - Ops structure for a struct
@@ -24,22 +24,22 @@ struct ttm_kmap_iter_ops {
 	 * kmap_local semantics.
 	 * @res_iter: Pointer to the struct ttm_kmap_iter representing
 	 * the resource.
-	 * @dmap: The struct dma_buf_map holding the virtual address after
+	 * @dmap: The struct iosys_map holding the virtual address after
 	 * the operation.
 	 * @i: The location within the resource to map. PAGE_SIZE granularity.
 	 */
 	void (*map_local)(struct ttm_kmap_iter *res_iter,
-			  struct dma_buf_map *dmap, pgoff_t i);
+			  struct iosys_map *dmap, pgoff_t i);
 	/**
 	 * unmap_local() - Unmap a PAGE_SIZE part of the resource previously
 	 * mapped using kmap_local.
 	 * @res_iter: Pointer to the struct ttm_kmap_iter representing
 	 * the resource.
-	 * @dmap: The struct dma_buf_map holding the virtual address after
+	 * @dmap: The struct iosys_map holding the virtual address after
 	 * the operation.
 	 */
 	void (*unmap_local)(struct ttm_kmap_iter *res_iter,
-			    struct dma_buf_map *dmap);
+			    struct iosys_map *dmap);
 	bool maps_tt;
 };
 
diff --git a/include/drm/ttm/ttm_resource.h b/include/drm/ttm/ttm_resource.h
index 5952051091cd..6eae09e382d2 100644
--- a/include/drm/ttm/ttm_resource.h
+++ b/include/drm/ttm/ttm_resource.h
@@ -27,7 +27,7 @@
 
 #include <linux/types.h>
 #include <linux/mutex.h>
-#include <linux/dma-buf-map.h>
+#include <linux/iosys-map.h>
 #include <linux/dma-fence.h>
 #include <drm/drm_print.h>
 #include <drm/ttm/ttm_caching.h>
@@ -41,7 +41,7 @@ struct ttm_resource;
 struct ttm_place;
 struct ttm_buffer_object;
 struct ttm_placement;
-struct dma_buf_map;
+struct iosys_map;
 struct io_mapping;
 struct sg_table;
 struct scatterlist;
@@ -207,7 +207,7 @@ struct ttm_kmap_iter_iomap {
  */
 struct ttm_kmap_iter_linear_io {
 	struct ttm_kmap_iter base;
-	struct dma_buf_map dmap;
+	struct iosys_map dmap;
 	bool needs_unmap;
 };
 
diff --git a/include/linux/dma-buf-map.h b/include/linux/dma-buf-map.h
deleted file mode 100644
index 278d489e4bdd..000000000000
--- a/include/linux/dma-buf-map.h
+++ /dev/null
@@ -1,266 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Pointer to dma-buf-mapped memory, plus helpers.
- */
-
-#ifndef __DMA_BUF_MAP_H__
-#define __DMA_BUF_MAP_H__
-
-#include <linux/io.h>
-#include <linux/string.h>
-
-/**
- * DOC: overview
- *
- * Calling dma-buf's vmap operation returns a pointer to the buffer's memory.
- * Depending on the location of the buffer, users may have to access it with
- * I/O operations or memory load/store operations. For example, copying to
- * system memory could be done with memcpy(), copying to I/O memory would be
- * done with memcpy_toio().
- *
- * .. code-block:: c
- *
- *	void *vaddr = ...; // pointer to system memory
- *	memcpy(vaddr, src, len);
- *
- *	void *vaddr_iomem = ...; // pointer to I/O memory
- *	memcpy_toio(vaddr, _iomem, src, len);
- *
- * When using dma-buf's vmap operation, the returned pointer is encoded as
- * :c:type:`struct dma_buf_map <dma_buf_map>`.
- * :c:type:`struct dma_buf_map <dma_buf_map>` stores the buffer's address in
- * system or I/O memory and a flag that signals the required method of
- * 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 <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 <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 <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,
- * instances of :c:type:`struct dma_buf_map <dma_buf_map>` can be initialized
- * statically with DMA_BUF_MAP_INIT_VADDR(), or at runtime with
- * dma_buf_map_set_vaddr(). These helpers will set an address in system memory.
- *
- * .. code-block:: c
- *
- *	struct dma_buf_map map = DMA_BUF_MAP_INIT_VADDR(0xdeadbeaf);
- *
- *	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);
- *
- * 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().
- *
- * .. code-block:: c
- *
- *	if (dma_buf_map_is_set(&map) != dma_buf_map_is_null(&map))
- *		// always true
- *
- * Instances of :c:type:`struct dma_buf_map <dma_buf_map>` can be compared
- * for equality with dma_buf_map_is_equal(). Mappings the point to different
- * memory spaces, system or I/O, are never equal. That's even true if both
- * spaces are located in the same address space, both mappings contain the
- * same address value, or both mappings refer to NULL.
- *
- * .. code-block:: c
- *
- *	struct dma_buf_map sys_map; // refers to system memory
- *	struct dma_buf_map io_map; // refers to I/O memory
- *
- *	if (dma_buf_map_is_equal(&sys_map, &io_map))
- *		// always false
- *
- * 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().
- *
- * .. 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
- */
-
-/**
- * struct dma_buf_map - Pointer to vmap'ed dma-buf memory.
- * @vaddr_iomem:	The buffer's address if in I/O memory
- * @vaddr:		The buffer's address if in system memory
- * @is_iomem:		True if the dma-buf memory is located in I/O
- *			memory, or false otherwise.
- */
-struct dma_buf_map {
-	union {
-		void __iomem *vaddr_iomem;
-		void *vaddr;
-	};
-	bool is_iomem;
-};
-
-/**
- * DMA_BUF_MAP_INIT_VADDR - Initializes struct dma_buf_map to an address in system memory
- * @vaddr_:	A system-memory address
- */
-#define DMA_BUF_MAP_INIT_VADDR(vaddr_) \
-	{ \
-		.vaddr = (vaddr_), \
-		.is_iomem = false, \
-	}
-
-/**
- * dma_buf_map_set_vaddr - Sets a dma-buf mapping structure to an address in system memory
- * @map:	The dma-buf mapping structure
- * @vaddr:	A system-memory address
- *
- * Sets the address and clears the I/O-memory flag.
- */
-static inline void dma_buf_map_set_vaddr(struct dma_buf_map *map, void *vaddr)
-{
-	map->vaddr = 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
- * @rhs:	A dma-buf mapping structure to compare with
- *
- * Two dma-buf mapping structures are equal if they both refer to the same type of memory
- * and to the same address within that memory.
- *
- * Returns:
- * True is both structures are equal, or false otherwise.
- */
-static inline bool dma_buf_map_is_equal(const struct dma_buf_map *lhs,
-					const struct dma_buf_map *rhs)
-{
-	if (lhs->is_iomem != rhs->is_iomem)
-		return false;
-	else if (lhs->is_iomem)
-		return lhs->vaddr_iomem == rhs->vaddr_iomem;
-	else
-		return lhs->vaddr == rhs->vaddr;
-}
-
-/**
- * dma_buf_map_is_null - Tests for a dma-buf mapping to be NULL
- * @map:	The dma-buf mapping structure
- *
- * Depending on the state of struct dma_buf_map.is_iomem, tests if the
- * mapping is NULL.
- *
- * Returns:
- * True if the mapping is NULL, or false otherwise.
- */
-static inline bool dma_buf_map_is_null(const struct dma_buf_map *map)
-{
-	if (map->is_iomem)
-		return !map->vaddr_iomem;
-	return !map->vaddr;
-}
-
-/**
- * dma_buf_map_is_set - Tests is the dma-buf mapping has been set
- * @map:	The dma-buf mapping structure
- *
- * Depending on the state of struct dma_buf_map.is_iomem, tests if the
- * mapping has been set.
- *
- * Returns:
- * True if the mapping is been set, or false otherwise.
- */
-static inline bool dma_buf_map_is_set(const struct dma_buf_map *map)
-{
-	return !dma_buf_map_is_null(map);
-}
-
-/**
- * dma_buf_map_clear - Clears a dma-buf mapping structure
- * @map:	The dma-buf mapping structure
- *
- * Clears all fields to zero; including struct dma_buf_map.is_iomem. So
- * mapping structures that were set to point to I/O memory are reset for
- * system memory. Pointers are cleared to NULL. This is the default.
- */
-static inline void dma_buf_map_clear(struct dma_buf_map *map)
-{
-	if (map->is_iomem) {
-		map->vaddr_iomem = NULL;
-		map->is_iomem = false;
-	} else {
-		map->vaddr = NULL;
-	}
-}
-
-/**
- * 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__ */
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 7ab50076e7a6..2097760e8e95 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -13,7 +13,7 @@
 #ifndef __DMA_BUF_H__
 #define __DMA_BUF_H__
 
-#include <linux/dma-buf-map.h>
+#include <linux/iosys-map.h>
 #include <linux/file.h>
 #include <linux/err.h>
 #include <linux/scatterlist.h>
@@ -283,8 +283,8 @@ struct dma_buf_ops {
 	 */
 	int (*mmap)(struct dma_buf *, struct vm_area_struct *vma);
 
-	int (*vmap)(struct dma_buf *dmabuf, struct dma_buf_map *map);
-	void (*vunmap)(struct dma_buf *dmabuf, struct dma_buf_map *map);
+	int (*vmap)(struct dma_buf *dmabuf, struct iosys_map *map);
+	void (*vunmap)(struct dma_buf *dmabuf, struct iosys_map *map);
 };
 
 /**
@@ -347,7 +347,7 @@ struct dma_buf {
 	 * @vmap_ptr:
 	 * The current vmap ptr if @vmapping_counter > 0. Protected by @lock.
 	 */
-	struct dma_buf_map vmap_ptr;
+	struct iosys_map vmap_ptr;
 
 	/**
 	 * @exp_name:
@@ -628,6 +628,6 @@ int dma_buf_end_cpu_access(struct dma_buf *dma_buf,
 
 int dma_buf_mmap(struct dma_buf *, struct vm_area_struct *,
 		 unsigned long);
-int dma_buf_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map);
-void dma_buf_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map);
+int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map);
+void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map);
 #endif /* __DMA_BUF_H__ */
diff --git a/include/linux/iosys-map.h b/include/linux/iosys-map.h
new file mode 100644
index 000000000000..f4186f91caa6
--- /dev/null
+++ b/include/linux/iosys-map.h
@@ -0,0 +1,257 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Pointer abstraction for IO/system memory
+ */
+
+#ifndef __IOSYS_MAP_H__
+#define __IOSYS_MAP_H__
+
+#include <linux/io.h>
+#include <linux/string.h>
+
+/**
+ * DOC: overview
+ *
+ * When accessing a memory region, depending on its location, users may have to
+ * access it with I/O operations or memory load/store operations. For example,
+ * copying to system memory could be done with memcpy(), copying to I/O memory
+ * would be done with memcpy_toio().
+ *
+ * .. code-block:: c
+ *
+ *	void *vaddr = ...; // pointer to system memory
+ *	memcpy(vaddr, src, len);
+ *
+ *	void *vaddr_iomem = ...; // pointer to I/O memory
+ *	memcpy_toio(vaddr, _iomem, src, len);
+ *
+ * The user of such pointer may not have information about the mapping of that
+ * region or may want to have a single code path to handle operations on that
+ * buffer, regardless if it's located in system or IO memory. The type
+ * :c:type:`struct iosys_map <iosys_map>` and its helpers abstract that so the
+ * buffer can be passed around to other drivers or have separate duties inside
+ * the same driver for allocation, read and write operations.
+ *
+ * Open-coding access to :c:type:`struct iosys_map <iosys_map>` is considered
+ * bad style. Rather then accessing its fields directly, use one of the provided
+ * helper functions, or implement your own. For example, instances of
+ * :c:type:`struct iosys_map <iosys_map>` can be initialized statically with
+ * IOSYS_MAP_INIT_VADDR(), or at runtime with iosys_map_set_vaddr(). These
+ * helpers will set an address in system memory.
+ *
+ * .. code-block:: c
+ *
+ *	struct iosys_map map = IOSYS_MAP_INIT_VADDR(0xdeadbeaf);
+ *
+ *	iosys_map_set_vaddr(&map, 0xdeadbeaf);
+ *
+ * To set an address in I/O memory, use iosys_map_set_vaddr_iomem().
+ *
+ * .. code-block:: c
+ *
+ *	iosys_map_set_vaddr_iomem(&map, 0xdeadbeaf);
+ *
+ * Instances of struct iosys_map do not have to be cleaned up, but
+ * can be cleared to NULL with iosys_map_clear(). Cleared mappings
+ * always refer to system memory.
+ *
+ * .. code-block:: c
+ *
+ *	iosys_map_clear(&map);
+ *
+ * Test if a mapping is valid with either iosys_map_is_set() or
+ * iosys_map_is_null().
+ *
+ * .. code-block:: c
+ *
+ *	if (iosys_map_is_set(&map) != iosys_map_is_null(&map))
+ *		// always true
+ *
+ * Instances of :c:type:`struct iosys_map <iosys_map>` can be compared for
+ * equality with iosys_map_is_equal(). Mappings that point to different memory
+ * spaces, system or I/O, are never equal. That's even true if both spaces are
+ * located in the same address space, both mappings contain the same address
+ * value, or both mappings refer to NULL.
+ *
+ * .. code-block:: c
+ *
+ *	struct iosys_map sys_map; // refers to system memory
+ *	struct iosys_map io_map; // refers to I/O memory
+ *
+ *	if (iosys_map_is_equal(&sys_map, &io_map))
+ *		// always false
+ *
+ * A set up instance of struct iosys_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
+ * iosys_map_memcpy_to(). The address can be manipulated with iosys_map_incr().
+ *
+ * .. code-block:: c
+ *
+ *	const void *src = ...; // source buffer
+ *	size_t len = ...; // length of src
+ *
+ *	iosys_map_memcpy_to(&map, src, len);
+ *	iosys_map_incr(&map, len); // go to first byte after the memcpy
+ */
+
+/**
+ * struct iosys_map - Pointer to IO/system memory
+ * @vaddr_iomem:	The buffer's address if in I/O memory
+ * @vaddr:		The buffer's address if in system memory
+ * @is_iomem:		True if the buffer is located in I/O memory, or false
+ *			otherwise.
+ */
+struct iosys_map {
+	union {
+		void __iomem *vaddr_iomem;
+		void *vaddr;
+	};
+	bool is_iomem;
+};
+
+/**
+ * IOSYS_MAP_INIT_VADDR - Initializes struct iosys_map to an address in system memory
+ * @vaddr_:	A system-memory address
+ */
+#define IOSYS_MAP_INIT_VADDR(vaddr_)	\
+	{				\
+		.vaddr = (vaddr_),	\
+		.is_iomem = false,	\
+	}
+
+/**
+ * iosys_map_set_vaddr - Sets a iosys mapping structure to an address in system memory
+ * @map:	The iosys_map structure
+ * @vaddr:	A system-memory address
+ *
+ * Sets the address and clears the I/O-memory flag.
+ */
+static inline void iosys_map_set_vaddr(struct iosys_map *map, void *vaddr)
+{
+	map->vaddr = vaddr;
+	map->is_iomem = false;
+}
+
+/**
+ * iosys_map_set_vaddr_iomem - Sets a iosys mapping structure to an address in I/O memory
+ * @map:		The iosys_map structure
+ * @vaddr_iomem:	An I/O-memory address
+ *
+ * Sets the address and the I/O-memory flag.
+ */
+static inline void iosys_map_set_vaddr_iomem(struct iosys_map *map,
+					     void __iomem *vaddr_iomem)
+{
+	map->vaddr_iomem = vaddr_iomem;
+	map->is_iomem = true;
+}
+
+/**
+ * iosys_map_is_equal - Compares two iosys mapping structures for equality
+ * @lhs:	The iosys_map structure
+ * @rhs:	A iosys_map structure to compare with
+ *
+ * Two iosys mapping structures are equal if they both refer to the same type of memory
+ * and to the same address within that memory.
+ *
+ * Returns:
+ * True is both structures are equal, or false otherwise.
+ */
+static inline bool iosys_map_is_equal(const struct iosys_map *lhs,
+				      const struct iosys_map *rhs)
+{
+	if (lhs->is_iomem != rhs->is_iomem)
+		return false;
+	else if (lhs->is_iomem)
+		return lhs->vaddr_iomem == rhs->vaddr_iomem;
+	else
+		return lhs->vaddr == rhs->vaddr;
+}
+
+/**
+ * iosys_map_is_null - Tests for a iosys mapping to be NULL
+ * @map:	The iosys_map structure
+ *
+ * Depending on the state of struct iosys_map.is_iomem, tests if the
+ * mapping is NULL.
+ *
+ * Returns:
+ * True if the mapping is NULL, or false otherwise.
+ */
+static inline bool iosys_map_is_null(const struct iosys_map *map)
+{
+	if (map->is_iomem)
+		return !map->vaddr_iomem;
+	return !map->vaddr;
+}
+
+/**
+ * iosys_map_is_set - Tests if the iosys mapping has been set
+ * @map:	The iosys_map structure
+ *
+ * Depending on the state of struct iosys_map.is_iomem, tests if the
+ * mapping has been set.
+ *
+ * Returns:
+ * True if the mapping is been set, or false otherwise.
+ */
+static inline bool iosys_map_is_set(const struct iosys_map *map)
+{
+	return !iosys_map_is_null(map);
+}
+
+/**
+ * iosys_map_clear - Clears a iosys mapping structure
+ * @map:	The iosys_map structure
+ *
+ * Clears all fields to zero, including struct iosys_map.is_iomem, so
+ * mapping structures that were set to point to I/O memory are reset for
+ * system memory. Pointers are cleared to NULL. This is the default.
+ */
+static inline void iosys_map_clear(struct iosys_map *map)
+{
+	if (map->is_iomem) {
+		map->vaddr_iomem = NULL;
+		map->is_iomem = false;
+	} else {
+		map->vaddr = NULL;
+	}
+}
+
+/**
+ * iosys_map_memcpy_to - Memcpy into iosys mapping
+ * @dst:	The iosys_map structure
+ * @src:	The source buffer
+ * @len:	The number of byte in src
+ *
+ * Copies data into a iosys 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 iosys_map_memcpy_to(struct iosys_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);
+}
+
+/**
+ * iosys_map_incr - Increments the address stored in a iosys mapping
+ * @map:	The iosys_map structure
+ * @incr:	The number of bytes to increment
+ *
+ * Increments the address stored in a iosys mapping. Depending on the
+ * buffer's location, the correct value will be updated.
+ */
+static inline void iosys_map_incr(struct iosys_map *map, size_t incr)
+{
+	if (map->is_iomem)
+		map->vaddr_iomem += incr;
+	else
+		map->vaddr += incr;
+}
+
+#endif /* __IOSYS_MAP_H__ */