1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_DMA_MAPPING_H
3 #define _LINUX_DMA_MAPPING_H
4 
5 #ifdef CONFIG_HAS_DMA
6 # error Virtio userspace code does not support CONFIG_HAS_DMA
7 #endif
8 
9 enum dma_data_direction {
10 	DMA_BIDIRECTIONAL = 0,
11 	DMA_TO_DEVICE = 1,
12 	DMA_FROM_DEVICE = 2,
13 	DMA_NONE = 3,
14 };
15 
16 #define dma_alloc_coherent(d, s, hp, f) ({ \
17 	void *__dma_alloc_coherent_p = kmalloc((s), (f)); \
18 	*(hp) = (unsigned long)__dma_alloc_coherent_p; \
19 	__dma_alloc_coherent_p; \
20 })
21 
22 #define dma_free_coherent(d, s, p, h) kfree(p)
23 
24 #define dma_map_page(d, p, o, s, dir) (page_to_phys(p) + (o))
25 
26 #define dma_map_single(d, p, s, dir) (virt_to_phys(p))
27 #define dma_map_single_attrs(d, p, s, dir, a) (virt_to_phys(p))
28 #define dma_mapping_error(...) (0)
29 
30 #define dma_unmap_single(d, a, s, r) do { (void)(d); (void)(a); (void)(s); (void)(r); } while (0)
31 #define dma_unmap_page(d, a, s, r) do { (void)(d); (void)(a); (void)(s); (void)(r); } while (0)
32 
33 #define sg_dma_address(sg) (0)
34 #define sg_dma_len(sg) (0)
35 #define dma_need_sync(v, a) (0)
36 #define dma_unmap_single_attrs(d, a, s, r, t) do { \
37 	(void)(d); (void)(a); (void)(s); (void)(r); (void)(t); \
38 } while (0)
39 #define dma_sync_single_range_for_cpu(d, a, o, s, r) do { \
40 	(void)(d); (void)(a); (void)(o); (void)(s); (void)(r); \
41 } while (0)
42 #define dma_sync_single_range_for_device(d, a, o, s, r) do { \
43 	(void)(d); (void)(a); (void)(o); (void)(s); (void)(r); \
44 } while (0)
45 #define dma_max_mapping_size(...) SIZE_MAX
46 
47 /*
48  * A dma_addr_t can hold any valid DMA or bus address for the platform.  It can
49  * be given to a device to use as a DMA source or target.  It is specific to a
50  * given device and there may be a translation between the CPU physical address
51  * space and the bus address space.
52  *
53  * DMA_MAPPING_ERROR is the magic error code if a mapping failed.  It should not
54  * be used directly in drivers, but checked for using dma_mapping_error()
55  * instead.
56  */
57 #define DMA_MAPPING_ERROR		(~(dma_addr_t)0)
58 
59 #endif
60