tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
50static int ipath_mapping_error(struct ib_device *dev, u64 dma_addr)
51{
52 return dma_addr == BAD_DMA_ADDRESS;
53}
54
55static 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
63static 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
70static 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
90done:
91 return addr;
92}
93
94static 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
101static 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 }
119 return ret;
120}
121
122static void ipath_unmap_sg(struct ib_device *dev,
123 struct scatterlist *sg, int nents,
124 enum dma_data_direction direction)
125{
126 BUG_ON(!valid_dma_direction(direction));
127}
128
129static u64 ipath_sg_dma_address(struct ib_device *dev, struct scatterlist *sg)
130{
131 u64 addr = (u64) page_address(sg_page(sg));
132
133 if (addr)
134 addr += sg->offset;
135 return addr;
136}
137
138static unsigned int ipath_sg_dma_len(struct ib_device *dev,
139 struct scatterlist *sg)
140{
141 return sg->length;
142}
143
144static void ipath_sync_single_for_cpu(struct ib_device *dev,
145 u64 addr,
146 size_t size,
147 enum dma_data_direction dir)
148{
149}
150
151static void ipath_sync_single_for_device(struct ib_device *dev,
152 u64 addr,
153 size_t size,
154 enum dma_data_direction dir)
155{
156}
157
158static void *ipath_dma_alloc_coherent(struct ib_device *dev, size_t size,
159 u64 *dma_handle, gfp_t flag)
160{
161 struct page *p;
162 void *addr = NULL;
163
164 p = alloc_pages(flag, get_order(size));
165 if (p)
166 addr = page_address(p);
167 if (dma_handle)
168 *dma_handle = (u64) addr;
169 return addr;
170}
171
172static void ipath_dma_free_coherent(struct ib_device *dev, size_t size,
173 void *cpu_addr, u64 dma_handle)
174{
175 free_pages((unsigned long) cpu_addr, get_order(size));
176}
177
178struct ib_dma_mapping_ops ipath_dma_mapping_ops = {
179 ipath_mapping_error,
180 ipath_dma_map_single,
181 ipath_dma_unmap_single,
182 ipath_dma_map_page,
183 ipath_dma_unmap_page,
184 ipath_map_sg,
185 ipath_unmap_sg,
186 ipath_sg_dma_address,
187 ipath_sg_dma_len,
188 ipath_sync_single_for_cpu,
189 ipath_sync_single_for_device,
190 ipath_dma_alloc_coherent,
191 ipath_dma_free_coherent
192};