drivers/infiniband/hw/hfi1/dma.c

   1 /*
   2  * Copyright(c) 2015, 2016 Intel Corporation.
   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
  50 #include "verbs.h"
  51
  52 #define BAD_DMA_ADDRESS ((u64)0)
  53
  54 /*
  55  * The following functions implement driver specific replacements
  56  * for the ib_dma_*() functions.
  57  *
  58  * These functions return kernel virtual addresses instead of
  59  * device bus addresses since the driver uses the CPU to copy
  60  * data instead of using hardware DMA.
  61  */
  62
  63 static int hfi1_mapping_error(struct ib_device *dev, u64 dma_addr)
  64 {
  65         return dma_addr == BAD_DMA_ADDRESS;
  66 }
  67
  68 static u64 hfi1_dma_map_single(struct ib_device *dev, void *cpu_addr,
  69                                size_t size, enum dma_data_direction direction)
  70 {
  71         if (WARN_ON(!valid_dma_direction(direction)))
  72                 return BAD_DMA_ADDRESS;
  73
  74         return (u64)cpu_addr;
  75 }
  76
  77 static void hfi1_dma_unmap_single(struct ib_device *dev, u64 addr, size_t size,
  78                                   enum dma_data_direction direction)
  79 {
  80         /* This is a stub, nothing to be done here */
  81 }
  82
  83 static u64 hfi1_dma_map_page(struct ib_device *dev, struct page *page,
  84                              unsigned long offset, size_t size,
  85                             enum dma_data_direction direction)
  86 {
  87         u64 addr;
  88
  89         if (WARN_ON(!valid_dma_direction(direction)))
  90                 return BAD_DMA_ADDRESS;
  91
  92         if (offset + size > PAGE_SIZE)
  93                 return BAD_DMA_ADDRESS;
  94
  95         addr = (u64)page_address(page);
  96         if (addr)
  97                 addr += offset;
  98
  99         return addr;
 100 }
 101
 102 static void hfi1_dma_unmap_page(struct ib_device *dev, u64 addr, size_t size,
 103                                 enum dma_data_direction direction)
 104 {
 105         /* This is a stub, nothing to be done here */
 106 }
 107
 108 static int hfi1_map_sg(struct ib_device *dev, struct scatterlist *sgl,
 109                        int nents, enum dma_data_direction direction)
 110 {
 111         struct scatterlist *sg;
 112         u64 addr;
 113         int i;
 114         int ret = nents;
 115
 116         if (WARN_ON(!valid_dma_direction(direction)))
 117                 return BAD_DMA_ADDRESS;
 118
 119         for_each_sg(sgl, sg, nents, i) {
 120                 addr = (u64)page_address(sg_page(sg));
 121                 if (!addr) {
 122                         ret = 0;
 123                         break;
 124                 }
 125                 sg->dma_address = addr + sg->offset;
 126 #ifdef CONFIG_NEED_SG_DMA_LENGTH
 127                 sg->dma_length = sg->length;
 128 #endif
 129         }
 130         return ret;
 131 }
 132
 133 static void hfi1_unmap_sg(struct ib_device *dev,
 134                           struct scatterlist *sg, int nents,
 135                          enum dma_data_direction direction)
 136 {
 137         /* This is a stub, nothing to be done here */
 138 }
 139
 140 static void hfi1_sync_single_for_cpu(struct ib_device *dev, u64 addr,
 141                                      size_t size, enum dma_data_direction dir)
 142 {
 143 }
 144
 145 static void hfi1_sync_single_for_device(struct ib_device *dev, u64 addr,
 146                                         size_t size,
 147                                         enum dma_data_direction dir)
 148 {
 149 }
 150
 151 static void *hfi1_dma_alloc_coherent(struct ib_device *dev, size_t size,
 152                                      u64 *dma_handle, gfp_t flag)
 153 {
 154         struct page *p;
 155         void *addr = NULL;
 156
 157         p = alloc_pages(flag, get_order(size));
 158         if (p)
 159                 addr = page_address(p);
 160         if (dma_handle)
 161                 *dma_handle = (u64)addr;
 162         return addr;
 163 }
 164
 165 static void hfi1_dma_free_coherent(struct ib_device *dev, size_t size,
 166                                    void *cpu_addr, u64 dma_handle)
 167 {
 168         free_pages((unsigned long)cpu_addr, get_order(size));
 169 }
 170
 171 struct ib_dma_mapping_ops hfi1_dma_mapping_ops = {
 172         .mapping_error = hfi1_mapping_error,
 173         .map_single = hfi1_dma_map_single,
 174         .unmap_single = hfi1_dma_unmap_single,
 175         .map_page = hfi1_dma_map_page,
 176         .unmap_page = hfi1_dma_unmap_page,
 177         .map_sg = hfi1_map_sg,
 178         .unmap_sg = hfi1_unmap_sg,
 179         .sync_single_for_cpu = hfi1_sync_single_for_cpu,
 180         .sync_single_for_device = hfi1_sync_single_for_device,
 181         .alloc_coherent = hfi1_dma_alloc_coherent,
 182         .free_coherent = hfi1_dma_free_coherent
 183 };