1 /* 2 * Copyright (c) 2015-2016 François Tigeot 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 36 #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : (1ULL<<(n)) - 1) 37 38 static inline dma_addr_t 39 dma_map_page(struct device *dev, struct vm_page *page, 40 unsigned long offset, size_t size, enum dma_data_direction direction) 41 { 42 return VM_PAGE_TO_PHYS(page) + offset; 43 } 44 45 static inline void dma_unmap_page(struct device *dev, dma_addr_t addr, 46 size_t size, enum dma_data_direction dir) 47 { 48 } 49 50 static inline int 51 dma_mapping_error(struct device *dev, dma_addr_t dma_addr) 52 { 53 return 0; 54 } 55 56 static inline int 57 dma_map_sg(struct device *dev, struct scatterlist *sg, 58 int nents, enum dma_data_direction dir) 59 { 60 struct scatterlist *s; 61 int i; 62 63 for_each_sg(sg, s, nents, i) 64 s->dma_address = sg_phys(s); 65 66 return nents; 67 } 68 69 static inline void 70 dma_unmap_sg(struct device *dev, struct scatterlist *sg, 71 int nents, enum dma_data_direction dir) 72 { 73 } 74 75 static inline void * 76 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, 77 gfp_t flag) 78 { 79 vm_paddr_t high; 80 size_t align; 81 void *mem; 82 83 #if 0 /* XXX swildner */ 84 if (dev->dma_mask) 85 high = *dev->dma_mask; 86 else 87 #endif 88 high = BUS_SPACE_MAXADDR_32BIT; 89 align = PAGE_SIZE << get_order(size); 90 mem = (void *)kmem_alloc_contig(size, 0, high, align); 91 if (mem) 92 *dma_handle = vtophys(mem); 93 else 94 *dma_handle = 0; 95 return (mem); 96 } 97 98 static inline void 99 dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, 100 dma_addr_t dma_handle) 101 { 102 103 kmem_free(&kernel_map, (vm_offset_t)cpu_addr, size); 104 } 105 106 #endif /* _LINUX_DMA-MAPPING_H_ */ 107