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

1 files changed, 9 insertions, 6 deletions

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 621924116eb4..3e738aea2664 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -286,13 +286,14 @@ void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem)
 }
 EXPORT_SYMBOL(drm_gem_shmem_unpin);
 
-static int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem, struct dma_buf_map *map)
+static int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem,
+				     struct iosys_map *map)
 {
 	struct drm_gem_object *obj = &shmem->base;
 	int ret = 0;
 
 	if (shmem->vmap_use_count++ > 0) {
-		dma_buf_map_set_vaddr(map, shmem->vaddr);
+		iosys_map_set_vaddr(map, shmem->vaddr);
 		return 0;
 	}
 
@@ -319,7 +320,7 @@ static int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem, struct
 		if (!shmem->vaddr)
 			ret = -ENOMEM;
 		else
-			dma_buf_map_set_vaddr(map, shmem->vaddr);
+			iosys_map_set_vaddr(map, shmem->vaddr);
 	}
 
 	if (ret) {
@@ -353,7 +354,8 @@ err_zero_use:
  * Returns:
  * 0 on success or a negative error code on failure.
  */
-int drm_gem_shmem_vmap(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)
 {
 	int ret;
 
@@ -368,7 +370,7 @@ int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem, struct dma_buf_map *m
 EXPORT_SYMBOL(drm_gem_shmem_vmap);
 
 static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
-					struct dma_buf_map *map)
+					struct iosys_map *map)
 {
 	struct drm_gem_object *obj = &shmem->base;
 
@@ -400,7 +402,8 @@ static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
  * This function hides the differences between dma-buf imported and natively
  * allocated objects.
  */
-void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem, struct dma_buf_map *map)
+void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem,
+			  struct iosys_map *map)
 {
 	mutex_lock(&shmem->vmap_lock);
 	drm_gem_shmem_vunmap_locked(shmem, map);