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