1 /* 2 * Copyright (c) 2015-2018 François Tigeot <ftigeot@wolfpond.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #ifndef _LINUX_DMA_MAPPING_H_ 28 #define _LINUX_DMA_MAPPING_H_ 29 30 #include <linux/string.h> 31 #include <linux/device.h> 32 #include <linux/err.h> 33 #include <linux/dma-direction.h> 34 #include <linux/scatterlist.h> 35 #include <linux/bug.h> 36 37 #include <asm/dma-mapping.h> 38 39 #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : (1ULL<<(n)) - 1) 40 41 static inline dma_addr_t 42 dma_map_page(struct device *dev, struct page *page, 43 unsigned long offset, size_t size, enum dma_data_direction direction) 44 { 45 return VM_PAGE_TO_PHYS((struct vm_page *)page) + offset; 46 } 47 48 static inline void dma_unmap_page(struct device *dev, dma_addr_t addr, 49 size_t size, enum dma_data_direction dir) 50 { 51 } 52 53 static inline int 54 dma_mapping_error(struct device *dev, dma_addr_t dma_addr) 55 { 56 return 0; 57 } 58 59 static inline int 60 dma_map_sg(struct device *dev, struct scatterlist *sg, 61 int nents, enum dma_data_direction dir) 62 { 63 struct scatterlist *s; 64 int i; 65 66 for_each_sg(sg, s, nents, i) 67 s->dma_address = sg_phys(s); 68 69 return nents; 70 } 71 72 static inline void 73 dma_unmap_sg(struct device *dev, struct scatterlist *sg, 74 int nents, enum dma_data_direction dir) 75 { 76 } 77 78 void * 79 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, 80 gfp_t flag); 81 82 void 83 dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, 84 dma_addr_t dma_handle); 85 86 #endif /* _LINUX_DMA-MAPPING_H_ */ 87