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, 4 insertions, 3 deletions

diff --git a/drivers/gpu/drm/tiny/gm12u320.c b/drivers/gpu/drm/tiny/gm12u320.c
index 6bc0c298739c..648e585d40a8 100644
--- a/drivers/gpu/drm/tiny/gm12u320.c
+++ b/drivers/gpu/drm/tiny/gm12u320.c
@@ -95,7 +95,7 @@ struct gm12u320_device {
 		struct drm_rect          rect;
 		int frame;
 		int draw_status_timeout;
-		struct dma_buf_map src_map;
+		struct iosys_map src_map;
 	} fb_update;
 };
 
@@ -395,7 +395,8 @@ err:
 		GM12U320_ERR("Frame update error: %d\n", ret);
 }
 
-static void gm12u320_fb_mark_dirty(struct drm_framebuffer *fb, const struct dma_buf_map *map,
+static void gm12u320_fb_mark_dirty(struct drm_framebuffer *fb,
+				   const struct iosys_map *map,
 				   struct drm_rect *dirty)
 {
 	struct gm12u320_device *gm12u320 = to_gm12u320(fb->dev);
@@ -438,7 +439,7 @@ static void gm12u320_stop_fb_update(struct gm12u320_device *gm12u320)
 	mutex_lock(&gm12u320->fb_update.lock);
 	old_fb = gm12u320->fb_update.fb;
 	gm12u320->fb_update.fb = NULL;
-	dma_buf_map_clear(&gm12u320->fb_update.src_map);
+	iosys_map_clear(&gm12u320->fb_update.src_map);
 	mutex_unlock(&gm12u320->fb_update.lock);
 
 	drm_framebuffer_put(old_fb);