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

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

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

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
 

MAINTAINERS

@@ -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

@@ -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);
 }

drivers/dma-buf/heaps/cma_heap.c

@@ -202,7 +202,7 @@ static void *cma_heap_do_vmap(struct cma_heap_buffer *buffer)
 	return vaddr;
 }
 
-static int cma_heap_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
+static int cma_heap_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
 {
 	struct cma_heap_buffer *buffer = dmabuf->priv;
 	void *vaddr;
@@ -211,7 +211,7 @@ static int cma_heap_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
 	mutex_lock(&buffer->lock);
 	if (buffer->vmap_cnt) {
 		buffer->vmap_cnt++;
-		dma_buf_map_set_vaddr(map, buffer->vaddr);
+		iosys_map_set_vaddr(map, buffer->vaddr);
 		goto out;
 	}
 
@@ -222,14 +222,14 @@ static int cma_heap_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
 	}
 	buffer->vaddr = vaddr;
 	buffer->vmap_cnt++;
-	dma_buf_map_set_vaddr(map, buffer->vaddr);
+	iosys_map_set_vaddr(map, buffer->vaddr);
 out:
 	mutex_unlock(&buffer->lock);
 
 	return ret;
 }
 
-static void cma_heap_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
+static void cma_heap_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)
 {
 	struct cma_heap_buffer *buffer = dmabuf->priv;
 
@@ -239,7 +239,7 @@ static void cma_heap_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
 		buffer->vaddr = NULL;
 	}
 	mutex_unlock(&buffer->lock);
-	dma_buf_map_clear(map);
+	iosys_map_clear(map);
 }
 
 static void cma_heap_dma_buf_release(struct dma_buf *dmabuf)

drivers/dma-buf/heaps/system_heap.c

@@ -241,7 +241,7 @@ static void *system_heap_do_vmap(struct system_heap_buffer *buffer)
 	return vaddr;
 }
 
-static int system_heap_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
+static int system_heap_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
 {
 	struct system_heap_buffer *buffer = dmabuf->priv;
 	void *vaddr;
@@ -250,7 +250,7 @@ static int system_heap_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
 	mutex_lock(&buffer->lock);
 	if (buffer->vmap_cnt) {
 		buffer->vmap_cnt++;
-		dma_buf_map_set_vaddr(map, buffer->vaddr);
+		iosys_map_set_vaddr(map, buffer->vaddr);
 		goto out;
 	}
 
@@ -262,14 +262,14 @@ static int system_heap_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
 
 	buffer->vaddr = vaddr;
 	buffer->vmap_cnt++;
-	dma_buf_map_set_vaddr(map, buffer->vaddr);
+	iosys_map_set_vaddr(map, buffer->vaddr);
 out:
 	mutex_unlock(&buffer->lock);
 
 	return ret;
 }
 
-static void system_heap_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
+static void system_heap_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)
 {
 	struct system_heap_buffer *buffer = dmabuf->priv;
 
@@ -279,7 +279,7 @@ static void system_heap_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
 		buffer->vaddr = NULL;
 	}
 	mutex_unlock(&buffer->lock);
-	dma_buf_map_clear(map);
+	iosys_map_clear(map);
 }
 
 static void system_heap_dma_buf_release(struct dma_buf *dmabuf)

drivers/gpu/drm/ast/ast_drv.h

@@ -107,7 +107,7 @@ struct ast_cursor_plane {
 
 	struct {
 		struct drm_gem_vram_object *gbo;
-		struct dma_buf_map map;
+		struct iosys_map map;
 		u64 off;
 	} hwc[AST_DEFAULT_HWC_NUM];
 

drivers/gpu/drm/ast/ast_mode.c

@@ -801,11 +801,11 @@ ast_cursor_plane_helper_atomic_update(struct drm_plane *plane,
 	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(new_state);
 	struct drm_framebuffer *fb = new_state->fb;
 	struct ast_private *ast = to_ast_private(plane->dev);
-	struct dma_buf_map dst_map =
+	struct iosys_map dst_map =
 		ast_cursor_plane->hwc[ast_cursor_plane->next_hwc_index].map;
 	u64 dst_off =
 		ast_cursor_plane->hwc[ast_cursor_plane->next_hwc_index].off;
-	struct dma_buf_map src_map = shadow_plane_state->data[0];
+	struct iosys_map src_map = shadow_plane_state->data[0];
 	unsigned int offset_x, offset_y;
 	u16 x, y;
 	u8 x_offset, y_offset;
@@ -883,7 +883,7 @@ static void ast_cursor_plane_destroy(struct drm_plane *plane)
 	struct ast_cursor_plane *ast_cursor_plane = to_ast_cursor_plane(plane);
 	size_t i;
 	struct drm_gem_vram_object *gbo;
-	struct dma_buf_map map;
+	struct iosys_map map;
 
 	for (i = 0; i < ARRAY_SIZE(ast_cursor_plane->hwc); ++i) {
 		gbo = ast_cursor_plane->hwc[i].gbo;
@@ -910,7 +910,7 @@ static int ast_cursor_plane_init(struct ast_private *ast)
 	struct drm_plane *cursor_plane = &ast_cursor_plane->base;
 	size_t size, i;
 	struct drm_gem_vram_object *gbo;
-	struct dma_buf_map map;
+	struct iosys_map map;
 	int ret;
 	s64 off;
 

drivers/gpu/drm/drm_cache.c

@@ -28,10 +28,10 @@
  * Authors: Thomas Hellström <thomas-at-tungstengraphics-dot-com>
  */
 
-#include <linux/dma-buf-map.h>
+#include <linux/cc_platform.h>
 #include <linux/export.h>
 #include <linux/highmem.h>
-#include <linux/cc_platform.h>
+#include <linux/iosys-map.h>
 #include <xen/xen.h>
 
 #include <drm/drm_cache.h>
@@ -214,14 +214,14 @@ bool drm_need_swiotlb(int dma_bits)
 }
 EXPORT_SYMBOL(drm_need_swiotlb);
 
-static void memcpy_fallback(struct dma_buf_map *dst,
-			    const struct dma_buf_map *src,
+static void memcpy_fallback(struct iosys_map *dst,
+			    const struct iosys_map *src,
 			    unsigned long len)
 {
 	if (!dst->is_iomem && !src->is_iomem) {
 		memcpy(dst->vaddr, src->vaddr, len);
 	} else if (!src->is_iomem) {
-		dma_buf_map_memcpy_to(dst, src->vaddr, len);
+		iosys_map_memcpy_to(dst, src->vaddr, len);
 	} else if (!dst->is_iomem) {
 		memcpy_fromio(dst->vaddr, src->vaddr_iomem, len);
 	} else {
@@ -305,8 +305,8 @@ static void __drm_memcpy_from_wc(void *dst, const void *src, unsigned long len)
  * Tries an arch optimized memcpy for prefetching reading out of a WC region,
  * and if no such beast is available, falls back to a normal memcpy.
  */
-void drm_memcpy_from_wc(struct dma_buf_map *dst,
-			const struct dma_buf_map *src,
+void drm_memcpy_from_wc(struct iosys_map *dst,
+			const struct iosys_map *src,
 			unsigned long len)
 {
 	if (WARN_ON(in_interrupt())) {
@@ -343,8 +343,8 @@ void drm_memcpy_init_early(void)
 		static_branch_enable(&has_movntdqa);
 }
 #else
-void drm_memcpy_from_wc(struct dma_buf_map *dst,
-			const struct dma_buf_map *src,
+void drm_memcpy_from_wc(struct iosys_map *dst,
+			const struct iosys_map *src,
 			unsigned long len)
 {
 	WARN_ON(in_interrupt());

drivers/gpu/drm/drm_client.c

@@ -3,7 +3,7 @@
  * Copyright 2018 Noralf Trønnes
  */
 
-#include <linux/dma-buf-map.h>
+#include <linux/iosys-map.h>
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -309,9 +309,10 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u
  *	0 on success, or a negative errno code otherwise.
  */
 int
-drm_client_buffer_vmap(struct drm_client_buffer *buffer, struct dma_buf_map *map_copy)
+drm_client_buffer_vmap(struct drm_client_buffer *buffer,
+		       struct iosys_map *map_copy)
 {
-	struct dma_buf_map *map = &buffer->map;
+	struct iosys_map *map = &buffer->map;
 	int ret;
 
 	/*
@@ -342,7 +343,7 @@ EXPORT_SYMBOL(drm_client_buffer_vmap);
  */
 void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
 {
-	struct dma_buf_map *map = &buffer->map;
+	struct iosys_map *map = &buffer->map;
 
 	drm_gem_vunmap(buffer->gem, map);
 }