Masahiro Yamada | 6373a17 | 2020-02-14 16:40:19 +0900 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | #ifndef _LINUX_DMA_MAPPING_H |
| 3 | #define _LINUX_DMA_MAPPING_H |
| 4 | |
| 5 | #include <linux/dma-direction.h> |
| 6 | #include <linux/types.h> |
| 7 | #include <asm/dma-mapping.h> |
| 8 | #include <cpu_func.h> |
| 9 | |
| 10 | #define dma_mapping_error(x, y) 0 |
| 11 | |
| 12 | /** |
| 13 | * Map a buffer to make it available to the DMA device |
| 14 | * |
| 15 | * Linux-like DMA API that is intended to be used from drivers. This hides the |
| 16 | * underlying cache operation from drivers. Call this before starting the DMA |
| 17 | * transfer. In most of architectures in U-Boot, the virtual address matches to |
| 18 | * the physical address (but we have exceptions like sandbox). U-Boot does not |
| 19 | * support iommu at the driver level, so it also matches to the DMA address. |
| 20 | * Hence, this helper currently just performs the cache operation, then returns |
| 21 | * straight-mapped dma_address, which is intended to be set to the register of |
| 22 | * the DMA device. |
| 23 | * |
| 24 | * @vaddr: address of the buffer |
| 25 | * @len: length of the buffer |
| 26 | * @dir: the direction of DMA |
| 27 | */ |
| 28 | static inline dma_addr_t dma_map_single(void *vaddr, size_t len, |
| 29 | enum dma_data_direction dir) |
| 30 | { |
| 31 | unsigned long addr = (unsigned long)vaddr; |
| 32 | |
| 33 | len = ALIGN(len, ARCH_DMA_MINALIGN); |
| 34 | |
| 35 | if (dir == DMA_FROM_DEVICE) |
| 36 | invalidate_dcache_range(addr, addr + len); |
| 37 | else |
| 38 | flush_dcache_range(addr, addr + len); |
| 39 | |
| 40 | return addr; |
| 41 | } |
| 42 | |
| 43 | /** |
| 44 | * Unmap a buffer to make it available to CPU |
| 45 | * |
| 46 | * Linux-like DMA API that is intended to be used from drivers. This hides the |
| 47 | * underlying cache operation from drivers. Call this after finishin the DMA |
| 48 | * transfer. |
| 49 | * |
| 50 | * @addr: DMA address |
| 51 | * @len: length of the buffer |
| 52 | * @dir: the direction of DMA |
| 53 | */ |
| 54 | static inline void dma_unmap_single(dma_addr_t addr, size_t len, |
| 55 | enum dma_data_direction dir) |
| 56 | { |
| 57 | len = ALIGN(len, ARCH_DMA_MINALIGN); |
| 58 | |
| 59 | if (dir != DMA_TO_DEVICE) |
| 60 | invalidate_dcache_range(addr, addr + len); |
| 61 | } |
| 62 | |
| 63 | #endif |