1 /* SPDX-License-Identifier: GPL-2.0-only */
3  * Pointer to dma-buf-mapped memory, plus helpers.
15  * Calling dma-buf's vmap operation returns a pointer to the buffer's memory.
21  * .. code-block:: c
29  * When using dma-buf's vmap operation, the returned pointer is encoded as
37  * actually independent from the dma-buf infrastructure. When sharing buffers
39  * the buffers in a safe way. :c:type:`struct dma_buf_map <dma_buf_map>`
40  * solves this problem for dma-buf and its users. If other drivers or
41  * sub-systems require similar functionality, the type could be generalized
44  * Open-coding access to :c:type:`struct dma_buf_map <dma_buf_map>` is
51  * .. code-block:: c
53  *	struct dma_buf_map map = DMA_BUF_MAP_INIT_VADDR(0xdeadbeaf);
55  *	dma_buf_map_set_vaddr(&map. 0xdeadbeaf);
59  * .. code-block:: c
61  *	dma_buf_map_set_vaddr_iomem(&map. 0xdeadbeaf);
67  * .. code-block:: c
69  *	dma_buf_map_clear(&map);
74  * .. code-block:: c
76  *	if (dma_buf_map_is_set(&map) != dma_buf_map_is_null(&map))
85  * .. code-block:: c
99  * .. code-block:: c
104  *	dma_buf_map_memcpy_to(&map, src, len);
105  *	dma_buf_map_incr(&map, len); // go to first byte after the memcpy
109  * struct dma_buf_map - Pointer to vmap'ed dma-buf memory.
112  * @is_iomem:		True if the dma-buf memory is located in I/O
124  * DMA_BUF_MAP_INIT_VADDR - Initializes struct dma_buf_map to an address in system memory
125  * @vaddr_:	A system-memory address
134  * dma_buf_map_set_vaddr - Sets a dma-buf mapping structure to an address in system memory
135  * @map:	The dma-buf mapping structure
136  * @vaddr:	A system-memory address
138  * Sets the address and clears the I/O-memory flag.
140 static inline void dma_buf_map_set_vaddr(struct dma_buf_map *map, void *vaddr)  in dma_buf_map_set_vaddr()  argument
142 	map->vaddr = vaddr;  in dma_buf_map_set_vaddr()
143 	map->is_iomem = false;  in dma_buf_map_set_vaddr()
147  * dma_buf_map_set_vaddr_iomem - Sets a dma-buf mapping structure to an address in I/O memory
148  * @map:		The dma-buf mapping structure
149  * @vaddr_iomem:	An I/O-memory address
151  * Sets the address and the I/O-memory flag.
153 static inline void dma_buf_map_set_vaddr_iomem(struct dma_buf_map *map,  in dma_buf_map_set_vaddr_iomem()  argument
156 	map->vaddr_iomem = vaddr_iomem;  in dma_buf_map_set_vaddr_iomem()
157 	map->is_iomem = true;  in dma_buf_map_set_vaddr_iomem()
161  * dma_buf_map_is_equal - Compares two dma-buf mapping structures for equality
162  * @lhs:	The dma-buf mapping structure
163  * @rhs:	A dma-buf mapping structure to compare with
165  * Two dma-buf mapping structures are equal if they both refer to the same type of memory
174 	if (lhs->is_iomem != rhs->is_iomem)  in dma_buf_map_is_equal()
176 	else if (lhs->is_iomem)  in dma_buf_map_is_equal()
177 		return lhs->vaddr_iomem == rhs->vaddr_iomem;  in dma_buf_map_is_equal()
179 		return lhs->vaddr == rhs->vaddr;  in dma_buf_map_is_equal()
183  * dma_buf_map_is_null - Tests for a dma-buf mapping to be NULL
184  * @map:	The dma-buf mapping structure
192 static inline bool dma_buf_map_is_null(const struct dma_buf_map *map)  in dma_buf_map_is_null()  argument
194 	if (map->is_iomem)  in dma_buf_map_is_null()
195 		return !map->vaddr_iomem;  in dma_buf_map_is_null()
196 	return !map->vaddr;  in dma_buf_map_is_null()
200  * dma_buf_map_is_set - Tests is the dma-buf mapping has been set
201  * @map:	The dma-buf mapping structure
209 static inline bool dma_buf_map_is_set(const struct dma_buf_map *map)  in dma_buf_map_is_set()  argument
211 	return !dma_buf_map_is_null(map);  in dma_buf_map_is_set()
215  * dma_buf_map_clear - Clears a dma-buf mapping structure
216  * @map:	The dma-buf mapping structure
222 static inline void dma_buf_map_clear(struct dma_buf_map *map)  in dma_buf_map_clear()  argument
224 	if (map->is_iomem) {  in dma_buf_map_clear()
225 		map->vaddr_iomem = NULL;  in dma_buf_map_clear()
226 		map->is_iomem = false;  in dma_buf_map_clear()
228 		map->vaddr = NULL;  in dma_buf_map_clear()
233  * dma_buf_map_memcpy_to - Memcpy into dma-buf mapping
234  * @dst:	The dma-buf mapping structure
238  * Copies data into a dma-buf mapping. The source buffer is in system
244 	if (dst->is_iomem)  in dma_buf_map_memcpy_to()
245 		memcpy_toio(dst->vaddr_iomem, src, len);  in dma_buf_map_memcpy_to()
247 		memcpy(dst->vaddr, src, len);  in dma_buf_map_memcpy_to()
251  * dma_buf_map_incr - Increments the address stored in a dma-buf mapping
252  * @map:	The dma-buf mapping structure
255  * Increments the address stored in a dma-buf mapping. Depending on the
258 static inline void dma_buf_map_incr(struct dma_buf_map *map, size_t incr)  in dma_buf_map_incr()  argument
260 	if (map->is_iomem)  in dma_buf_map_incr()
261 		map->vaddr_iomem += incr;  in dma_buf_map_incr()
263 		map->vaddr += incr;  in dma_buf_map_incr()