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

2 files changed, 7 insertions, 5 deletions

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
index d0544962cfc1..139d7724c6d0 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
@@ -220,7 +220,7 @@ struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev,
 	return &mtk_gem->base;
 }
 
-int mtk_drm_gem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
+int mtk_drm_gem_prime_vmap(struct drm_gem_object *obj, struct iosys_map *map)
 {
 	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
 	struct sg_table *sgt = NULL;
@@ -247,12 +247,13 @@ int mtk_drm_gem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
 
 out:
 	kfree(sgt);
-	dma_buf_map_set_vaddr(map, mtk_gem->kvaddr);
+	iosys_map_set_vaddr(map, mtk_gem->kvaddr);
 
 	return 0;
 }
 
-void mtk_drm_gem_prime_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map)
+void mtk_drm_gem_prime_vunmap(struct drm_gem_object *obj,
+			      struct iosys_map *map)
 {
 	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
 	void *vaddr = map->vaddr;
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.h b/drivers/gpu/drm/mediatek/mtk_drm_gem.h
index 9a359a06cb73..78f23b07a02e 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.h
@@ -42,7 +42,8 @@ int mtk_drm_gem_dumb_create(struct drm_file *file_priv, struct drm_device *dev,
 struct sg_table *mtk_gem_prime_get_sg_table(struct drm_gem_object *obj);
 struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev,
 			struct dma_buf_attachment *attach, struct sg_table *sg);
-int mtk_drm_gem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map);
-void mtk_drm_gem_prime_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map);
+int mtk_drm_gem_prime_vmap(struct drm_gem_object *obj, struct iosys_map *map);
+void mtk_drm_gem_prime_vunmap(struct drm_gem_object *obj,
+			      struct iosys_map *map);
 
 #endif