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_mapping_error(...) (0) 28 29 #define dma_unmap_single(...) do { } while (0) 30 #define dma_unmap_page(...) do { } while (0) 31 32 #define dma_max_mapping_size(...) SIZE_MAX 33 34 #endif 35