Dennis Dalessandro | c1b332b | 2016-01-06 09:51:18 -0800 | [diff] [blame] | 1 | /* |
Dennis Dalessandro | fe31419 | 2016-01-22 13:04:58 -0800 | [diff] [blame] | 2 | * Copyright(c) 2016 Intel Corporation. |
Dennis Dalessandro | c1b332b | 2016-01-06 09:51:18 -0800 | [diff] [blame] | 3 | * |
| 4 | * This file is provided under a dual BSD/GPLv2 license. When using or |
| 5 | * redistributing this file, you may do so under either license. |
| 6 | * |
| 7 | * GPL LICENSE SUMMARY |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of version 2 of the GNU General Public License as |
| 11 | * published by the Free Software Foundation. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, but |
| 14 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | * General Public License for more details. |
| 17 | * |
| 18 | * BSD LICENSE |
| 19 | * |
| 20 | * Redistribution and use in source and binary forms, with or without |
| 21 | * modification, are permitted provided that the following conditions |
| 22 | * are met: |
| 23 | * |
| 24 | * - Redistributions of source code must retain the above copyright |
| 25 | * notice, this list of conditions and the following disclaimer. |
| 26 | * - Redistributions in binary form must reproduce the above copyright |
| 27 | * notice, this list of conditions and the following disclaimer in |
| 28 | * the documentation and/or other materials provided with the |
| 29 | * distribution. |
| 30 | * - Neither the name of Intel Corporation nor the names of its |
| 31 | * contributors may be used to endorse or promote products derived |
| 32 | * from this software without specific prior written permission. |
| 33 | * |
| 34 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 35 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 36 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 37 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 38 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 39 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 40 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 41 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 42 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 43 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 44 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 45 | * |
| 46 | */ |
| 47 | #include <linux/types.h> |
| 48 | #include <linux/scatterlist.h> |
| 49 | #include <rdma/ib_verbs.h> |
| 50 | |
| 51 | #include "dma.h" |
| 52 | |
| 53 | #define BAD_DMA_ADDRESS ((u64)0) |
| 54 | |
| 55 | /* |
| 56 | * The following functions implement driver specific replacements |
| 57 | * for the ib_dma_*() functions. |
| 58 | * |
| 59 | * These functions return kernel virtual addresses instead of |
| 60 | * device bus addresses since the driver uses the CPU to copy |
| 61 | * data instead of using hardware DMA. |
| 62 | */ |
| 63 | |
| 64 | static int rvt_mapping_error(struct ib_device *dev, u64 dma_addr) |
| 65 | { |
| 66 | return dma_addr == BAD_DMA_ADDRESS; |
| 67 | } |
| 68 | |
| 69 | static u64 rvt_dma_map_single(struct ib_device *dev, void *cpu_addr, |
| 70 | size_t size, enum dma_data_direction direction) |
| 71 | { |
| 72 | if (WARN_ON(!valid_dma_direction(direction))) |
| 73 | return BAD_DMA_ADDRESS; |
| 74 | |
| 75 | return (u64)cpu_addr; |
| 76 | } |
| 77 | |
| 78 | static void rvt_dma_unmap_single(struct ib_device *dev, u64 addr, size_t size, |
| 79 | enum dma_data_direction direction) |
| 80 | { |
| 81 | /* This is a stub, nothing to be done here */ |
| 82 | } |
| 83 | |
| 84 | static u64 rvt_dma_map_page(struct ib_device *dev, struct page *page, |
| 85 | unsigned long offset, size_t size, |
| 86 | enum dma_data_direction direction) |
| 87 | { |
| 88 | u64 addr; |
| 89 | |
| 90 | if (WARN_ON(!valid_dma_direction(direction))) |
| 91 | return BAD_DMA_ADDRESS; |
| 92 | |
| 93 | if (offset + size > PAGE_SIZE) |
| 94 | return BAD_DMA_ADDRESS; |
| 95 | |
| 96 | addr = (u64)page_address(page); |
| 97 | if (addr) |
| 98 | addr += offset; |
| 99 | |
| 100 | return addr; |
| 101 | } |
| 102 | |
| 103 | static void rvt_dma_unmap_page(struct ib_device *dev, u64 addr, size_t size, |
| 104 | enum dma_data_direction direction) |
| 105 | { |
| 106 | /* This is a stub, nothing to be done here */ |
| 107 | } |
| 108 | |
| 109 | static int rvt_map_sg(struct ib_device *dev, struct scatterlist *sgl, |
| 110 | int nents, enum dma_data_direction direction) |
| 111 | { |
| 112 | struct scatterlist *sg; |
| 113 | u64 addr; |
| 114 | int i; |
| 115 | int ret = nents; |
| 116 | |
| 117 | if (WARN_ON(!valid_dma_direction(direction))) |
| 118 | return 0; |
| 119 | |
| 120 | for_each_sg(sgl, sg, nents, i) { |
| 121 | addr = (u64)page_address(sg_page(sg)); |
| 122 | if (!addr) { |
| 123 | ret = 0; |
| 124 | break; |
| 125 | } |
| 126 | sg->dma_address = addr + sg->offset; |
| 127 | #ifdef CONFIG_NEED_SG_DMA_LENGTH |
| 128 | sg->dma_length = sg->length; |
| 129 | #endif |
| 130 | } |
| 131 | return ret; |
| 132 | } |
| 133 | |
| 134 | static void rvt_unmap_sg(struct ib_device *dev, |
| 135 | struct scatterlist *sg, int nents, |
| 136 | enum dma_data_direction direction) |
| 137 | { |
| 138 | /* This is a stub, nothing to be done here */ |
| 139 | } |
| 140 | |
| 141 | static void rvt_sync_single_for_cpu(struct ib_device *dev, u64 addr, |
| 142 | size_t size, enum dma_data_direction dir) |
| 143 | { |
| 144 | } |
| 145 | |
| 146 | static void rvt_sync_single_for_device(struct ib_device *dev, u64 addr, |
| 147 | size_t size, |
| 148 | enum dma_data_direction dir) |
| 149 | { |
| 150 | } |
| 151 | |
| 152 | static void *rvt_dma_alloc_coherent(struct ib_device *dev, size_t size, |
| 153 | u64 *dma_handle, gfp_t flag) |
| 154 | { |
| 155 | struct page *p; |
| 156 | void *addr = NULL; |
| 157 | |
| 158 | p = alloc_pages(flag, get_order(size)); |
| 159 | if (p) |
| 160 | addr = page_address(p); |
| 161 | if (dma_handle) |
| 162 | *dma_handle = (u64)addr; |
| 163 | return addr; |
| 164 | } |
| 165 | |
| 166 | static void rvt_dma_free_coherent(struct ib_device *dev, size_t size, |
| 167 | void *cpu_addr, u64 dma_handle) |
| 168 | { |
| 169 | free_pages((unsigned long)cpu_addr, get_order(size)); |
| 170 | } |
| 171 | |
| 172 | struct ib_dma_mapping_ops rvt_default_dma_mapping_ops = { |
| 173 | .mapping_error = rvt_mapping_error, |
| 174 | .map_single = rvt_dma_map_single, |
| 175 | .unmap_single = rvt_dma_unmap_single, |
| 176 | .map_page = rvt_dma_map_page, |
| 177 | .unmap_page = rvt_dma_unmap_page, |
| 178 | .map_sg = rvt_map_sg, |
| 179 | .unmap_sg = rvt_unmap_sg, |
| 180 | .sync_single_for_cpu = rvt_sync_single_for_cpu, |
| 181 | .sync_single_for_device = rvt_sync_single_for_device, |
| 182 | .alloc_coherent = rvt_dma_alloc_coherent, |
| 183 | .free_coherent = rvt_dma_free_coherent |
| 184 | }; |