1 /*
2 * Copyright (c) 2006 QLogic, Corporation. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 */
32
33 #include <linux/scatterlist.h>
34 #include <linux/gfp.h>
35 #include <rdma/ib_verbs.h>
36
37 #include "ipath_verbs.h"
38
39 #define BAD_DMA_ADDRESS ((u64) 0)
40
41 /*
42 * The following functions implement driver specific replacements
43 * for the ib_dma_*() functions.
44 *
45 * These functions return kernel virtual addresses instead of
46 * device bus addresses since the driver uses the CPU to copy
47 * data instead of using hardware DMA.
48 */
49
ipath_mapping_error(struct ib_device * dev,u64 dma_addr)50 static int ipath_mapping_error(struct ib_device *dev, u64 dma_addr)
51 {
52 return dma_addr == BAD_DMA_ADDRESS;
53 }
54
ipath_dma_map_single(struct ib_device * dev,void * cpu_addr,size_t size,enum dma_data_direction direction)55 static u64 ipath_dma_map_single(struct ib_device *dev,
56 void *cpu_addr, size_t size,
57 enum dma_data_direction direction)
58 {
59 BUG_ON(!valid_dma_direction(direction));
60 return (u64) cpu_addr;
61 }
62
ipath_dma_unmap_single(struct ib_device * dev,u64 addr,size_t size,enum dma_data_direction direction)63 static void ipath_dma_unmap_single(struct ib_device *dev,
64 u64 addr, size_t size,
65 enum dma_data_direction direction)
66 {
67 BUG_ON(!valid_dma_direction(direction));
68 }
69
ipath_dma_map_page(struct ib_device * dev,struct page * page,unsigned long offset,size_t size,enum dma_data_direction direction)70 static u64 ipath_dma_map_page(struct ib_device *dev,
71 struct page *page,
72 unsigned long offset,
73 size_t size,
74 enum dma_data_direction direction)
75 {
76 u64 addr;
77
78 BUG_ON(!valid_dma_direction(direction));
79
80 if (offset + size > PAGE_SIZE) {
81 addr = BAD_DMA_ADDRESS;
82 goto done;
83 }
84
85 addr = (u64) page_address(page);
86 if (addr)
87 addr += offset;
88 /* TODO: handle highmem pages */
89
90 done:
91 return addr;
92 }
93
ipath_dma_unmap_page(struct ib_device * dev,u64 addr,size_t size,enum dma_data_direction direction)94 static void ipath_dma_unmap_page(struct ib_device *dev,
95 u64 addr, size_t size,
96 enum dma_data_direction direction)
97 {
98 BUG_ON(!valid_dma_direction(direction));
99 }
100
ipath_map_sg(struct ib_device * dev,struct scatterlist * sgl,int nents,enum dma_data_direction direction)101 static int ipath_map_sg(struct ib_device *dev, struct scatterlist *sgl,
102 int nents, enum dma_data_direction direction)
103 {
104 struct scatterlist *sg;
105 u64 addr;
106 int i;
107 int ret = nents;
108
109 BUG_ON(!valid_dma_direction(direction));
110
111 for_each_sg(sgl, sg, nents, i) {
112 addr = (u64) page_address(sg_page(sg));
113 /* TODO: handle highmem pages */
114 if (!addr) {
115 ret = 0;
116 break;
117 }
118 sg->dma_address = addr + sg->offset;
119 #ifdef CONFIG_NEED_SG_DMA_LENGTH
120 sg->dma_length = sg->length;
121 #endif
122 }
123 return ret;
124 }
125
ipath_unmap_sg(struct ib_device * dev,struct scatterlist * sg,int nents,enum dma_data_direction direction)126 static void ipath_unmap_sg(struct ib_device *dev,
127 struct scatterlist *sg, int nents,
128 enum dma_data_direction direction)
129 {
130 BUG_ON(!valid_dma_direction(direction));
131 }
132
ipath_sync_single_for_cpu(struct ib_device * dev,u64 addr,size_t size,enum dma_data_direction dir)133 static void ipath_sync_single_for_cpu(struct ib_device *dev,
134 u64 addr,
135 size_t size,
136 enum dma_data_direction dir)
137 {
138 }
139
ipath_sync_single_for_device(struct ib_device * dev,u64 addr,size_t size,enum dma_data_direction dir)140 static void ipath_sync_single_for_device(struct ib_device *dev,
141 u64 addr,
142 size_t size,
143 enum dma_data_direction dir)
144 {
145 }
146
ipath_dma_alloc_coherent(struct ib_device * dev,size_t size,u64 * dma_handle,gfp_t flag)147 static void *ipath_dma_alloc_coherent(struct ib_device *dev, size_t size,
148 u64 *dma_handle, gfp_t flag)
149 {
150 struct page *p;
151 void *addr = NULL;
152
153 p = alloc_pages(flag, get_order(size));
154 if (p)
155 addr = page_address(p);
156 if (dma_handle)
157 *dma_handle = (u64) addr;
158 return addr;
159 }
160
ipath_dma_free_coherent(struct ib_device * dev,size_t size,void * cpu_addr,u64 dma_handle)161 static void ipath_dma_free_coherent(struct ib_device *dev, size_t size,
162 void *cpu_addr, u64 dma_handle)
163 {
164 free_pages((unsigned long) cpu_addr, get_order(size));
165 }
166
167 struct ib_dma_mapping_ops ipath_dma_mapping_ops = {
168 .mapping_error = ipath_mapping_error,
169 .map_single = ipath_dma_map_single,
170 .unmap_single = ipath_dma_unmap_single,
171 .map_page = ipath_dma_map_page,
172 .unmap_page = ipath_dma_unmap_page,
173 .map_sg = ipath_map_sg,
174 .unmap_sg = ipath_unmap_sg,
175 .sync_single_for_cpu = ipath_sync_single_for_cpu,
176 .sync_single_for_device = ipath_sync_single_for_device,
177 .alloc_coherent = ipath_dma_alloc_coherent,
178 .free_coherent = ipath_dma_free_coherent
179 };
180