Commit 7938f421 authored by Lucas De Marchi's avatar Lucas De Marchi
Browse files

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: default avatarLucas De Marchi <lucas.demarchi@intel.com>
Acked-by: default avatarChristian König <christian.koenig@amd.com>
Acked-by: default avatarSumit Semwal <sumit.semwal@linaro.org>
Acked-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
parent 722b717d

Documentation/driver-api/device-io.rst

+9 −0
Original line number Diff line number Diff line
@@ -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

=========================

Documentation/driver-api/dma-buf.rst

+0 −9
Original line number Diff line number Diff line
@@ -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

-------------------

Documentation/gpu/todo.rst

+10 −10
Original line number Diff line number Diff line
@@ -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

MAINTAINERS

+8 −1
Original line number Diff line number Diff line
@@ -5734,7 +5734,7 @@ T: git git://anongit.freedesktop.org/drm/drm-misc 
F:	Documentation/driver-api/dma-buf.rst

F:	drivers/dma-buf/

F:	include/linux/*fence.h

F:	include/linux/dma-buf*

F:	include/linux/dma-buf.h

F:	include/linux/dma-resv.h

K:	\bdma_(?:buf|fence|resv)\b








@@ -10050,6 +10050,13 @@ F:	include/linux/iova.h







F:	include/linux/of_iommu.h









F:	include/uapi/linux/iommu.h

















IOSYS-MAP HELPERS









M:	Thomas Zimmermann <tzimmermann@suse.de>









L:	dri-devel@lists.freedesktop.org









S:	Maintained









T:	git git://anongit.freedesktop.org/drm/drm-misc









F:	include/linux/iosys-map.h

















IO_URING









M:	Jens Axboe <axboe@kernel.dk>









R:	Pavel Begunkov <asml.silence@gmail.com>
































drivers/dma-buf/dma-buf.c



+11
−11






























Original line number
Diff line number
Diff line







@@ -1047,8 +1047,8 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_move_notify, DMA_BUF);







 *









 *   Interfaces::









 *









 *      void \*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)









 *      void \*dma_buf_vmap(struct dma_buf \*dmabuf, struct iosys_map \*map)









 *      void dma_buf_vunmap(struct dma_buf \*dmabuf, struct iosys_map \*map)









 *









 *   The vmap call can fail if there is no vmap support in the exporter, or if









 *   it runs out of vmalloc space. Note that the dma-buf layer keeps a reference








@@ -1260,12 +1260,12 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, DMA_BUF);







 *









 * Returns 0 on success, or a negative errno code otherwise.









 */









int dma_buf_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)









int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map)









{









	struct dma_buf_map ptr;









	struct iosys_map ptr;









	int ret = 0;



















	dma_buf_map_clear(map);









	iosys_map_clear(map);



















	if (WARN_ON(!dmabuf))









		return -EINVAL;








@@ -1276,12 +1276,12 @@ int dma_buf_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)







	mutex_lock(&dmabuf->lock);









	if (dmabuf->vmapping_counter) {









		dmabuf->vmapping_counter++;









		BUG_ON(dma_buf_map_is_null(&dmabuf->vmap_ptr));









		BUG_ON(iosys_map_is_null(&dmabuf->vmap_ptr));









		*map = dmabuf->vmap_ptr;









		goto out_unlock;









	}



















	BUG_ON(dma_buf_map_is_set(&dmabuf->vmap_ptr));









	BUG_ON(iosys_map_is_set(&dmabuf->vmap_ptr));



















	ret = dmabuf->ops->vmap(dmabuf, &ptr);









	if (WARN_ON_ONCE(ret))








@@ -1303,20 +1303,20 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_vmap, DMA_BUF);







 * @dmabuf:	[in]	buffer to vunmap









 * @map:	[in]	vmap pointer to vunmap









 */









void dma_buf_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map)









void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)









{









	if (WARN_ON(!dmabuf))









		return;



















	BUG_ON(dma_buf_map_is_null(&dmabuf->vmap_ptr));









	BUG_ON(iosys_map_is_null(&dmabuf->vmap_ptr));









	BUG_ON(dmabuf->vmapping_counter == 0);









	BUG_ON(!dma_buf_map_is_equal(&dmabuf->vmap_ptr, map));









	BUG_ON(!iosys_map_is_equal(&dmabuf->vmap_ptr, map));



















	mutex_lock(&dmabuf->lock);









	if (--dmabuf->vmapping_counter == 0) {









		if (dmabuf->ops->vunmap)









			dmabuf->ops->vunmap(dmabuf, map);









		dma_buf_map_clear(&dmabuf->vmap_ptr);









		iosys_map_clear(&dmabuf->vmap_ptr);









	}









	mutex_unlock(&dmabuf->lock);









}