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

3 files changed, 19 insertions, 19 deletions

diff --git a/Documentation/driver-api/device-io.rst b/Documentation/driver-api/device-io.rst
index e9f04b1815d1..4d2baac0311c 100644
--- a/Documentation/driver-api/device-io.rst
+++ b/Documentation/driver-api/device-io.rst
@@ -502,6 +502,15 @@ pcim_iomap()
 Not using these wrappers may make drivers unusable on certain platforms with
 stricter rules for mapping I/O memory.
 
+Generalizing Access to System and I/O Memory
+============================================
+
+.. kernel-doc:: include/linux/iosys-map.h
+   :doc: overview
+
+.. kernel-doc:: include/linux/iosys-map.h
+   :internal:
+
 Public Functions Provided
 =========================
 
diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst
index 2cd7db82d9fe..55006678394a 100644
--- a/Documentation/driver-api/dma-buf.rst
+++ b/Documentation/driver-api/dma-buf.rst
@@ -128,15 +128,6 @@ Kernel Functions and Structures Reference
 .. kernel-doc:: include/linux/dma-buf.h
    :internal:
 
-Buffer Mapping Helpers
-~~~~~~~~~~~~~~~~~~~~~~
-
-.. kernel-doc:: include/linux/dma-buf-map.h
-   :doc: overview
-
-.. kernel-doc:: include/linux/dma-buf-map.h
-   :internal:
-
 Reservation Objects
 -------------------
 
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index da138dd39883..c8f39c1ef1ee 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -222,7 +222,7 @@ Convert drivers to use drm_fbdev_generic_setup()
 Most drivers can use drm_fbdev_generic_setup(). Driver have to implement
 atomic modesetting and GEM vmap support. Historically, generic fbdev emulation
 expected the framebuffer in system memory or system-like memory. By employing
-struct dma_buf_map, drivers with frambuffers in I/O memory can be supported
+struct iosys_map, drivers with frambuffers in I/O memory can be supported
 as well.
 
 Contact: Maintainer of the driver you plan to convert
@@ -234,7 +234,7 @@ Reimplement functions in drm_fbdev_fb_ops without fbdev
 
 A number of callback functions in drm_fbdev_fb_ops could benefit from
 being rewritten without dependencies on the fbdev module. Some of the
-helpers could further benefit from using struct dma_buf_map instead of
+helpers could further benefit from using struct iosys_map instead of
 raw pointers.
 
 Contact: Thomas Zimmermann <tzimmermann@suse.de>, Daniel Vetter
@@ -434,19 +434,19 @@ Contact: Emil Velikov, respective driver maintainers
 
 Level: Intermediate
 
-Use struct dma_buf_map throughout codebase
-------------------------------------------
+Use struct iosys_map throughout codebase
+----------------------------------------
 
-Pointers to shared device memory are stored in struct dma_buf_map. Each
+Pointers to shared device memory are stored in struct iosys_map. Each
 instance knows whether it refers to system or I/O memory. Most of the DRM-wide
-interface have been converted to use struct dma_buf_map, but implementations
+interface have been converted to use struct iosys_map, but implementations
 often still use raw pointers.
 
-The task is to use struct dma_buf_map where it makes sense.
+The task is to use struct iosys_map where it makes sense.
 
-* Memory managers should use struct dma_buf_map for dma-buf-imported buffers.
-* TTM might benefit from using struct dma_buf_map internally.
-* Framebuffer copying and blitting helpers should operate on struct dma_buf_map.
+* Memory managers should use struct iosys_map for dma-buf-imported buffers.
+* TTM might benefit from using struct iosys_map internally.
+* Framebuffer copying and blitting helpers should operate on struct iosys_map.
 
 Contact: Thomas Zimmermann <tzimmermann@suse.de>, Christian König, Daniel Vetter