GNU Linux-libre 4.9.287-gnu1
[releases.git] / drivers / infiniband / hw / qib / qib_dma.c
1 /*
2  * Copyright (c) 2006, 2009, 2010 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 #include <linux/types.h>
33 #include <linux/scatterlist.h>
34
35 #include "qib_verbs.h"
36
37 #define BAD_DMA_ADDRESS ((u64) 0)
38
39 /*
40  * The following functions implement driver specific replacements
41  * for the ib_dma_*() functions.
42  *
43  * These functions return kernel virtual addresses instead of
44  * device bus addresses since the driver uses the CPU to copy
45  * data instead of using hardware DMA.
46  */
47
48 static int qib_mapping_error(struct ib_device *dev, u64 dma_addr)
49 {
50         return dma_addr == BAD_DMA_ADDRESS;
51 }
52
53 static u64 qib_dma_map_single(struct ib_device *dev, void *cpu_addr,
54                               size_t size, enum dma_data_direction direction)
55 {
56         BUG_ON(!valid_dma_direction(direction));
57         return (u64) cpu_addr;
58 }
59
60 static void qib_dma_unmap_single(struct ib_device *dev, u64 addr, size_t size,
61                                  enum dma_data_direction direction)
62 {
63         BUG_ON(!valid_dma_direction(direction));
64 }
65
66 static u64 qib_dma_map_page(struct ib_device *dev, struct page *page,
67                             unsigned long offset, size_t size,
68                             enum dma_data_direction direction)
69 {
70         u64 addr;
71
72         BUG_ON(!valid_dma_direction(direction));
73
74         if (offset + size > PAGE_SIZE) {
75                 addr = BAD_DMA_ADDRESS;
76                 goto done;
77         }
78
79         addr = (u64) page_address(page);
80         if (addr)
81                 addr += offset;
82         /* TODO: handle highmem pages */
83
84 done:
85         return addr;
86 }
87
88 static void qib_dma_unmap_page(struct ib_device *dev, u64 addr, size_t size,
89                                enum dma_data_direction direction)
90 {
91         BUG_ON(!valid_dma_direction(direction));
92 }
93
94 static int qib_map_sg(struct ib_device *dev, struct scatterlist *sgl,
95                       int nents, enum dma_data_direction direction)
96 {
97         struct scatterlist *sg;
98         u64 addr;
99         int i;
100         int ret = nents;
101
102         BUG_ON(!valid_dma_direction(direction));
103
104         for_each_sg(sgl, sg, nents, i) {
105                 addr = (u64) page_address(sg_page(sg));
106                 /* TODO: handle highmem pages */
107                 if (!addr) {
108                         ret = 0;
109                         break;
110                 }
111                 sg->dma_address = addr + sg->offset;
112 #ifdef CONFIG_NEED_SG_DMA_LENGTH
113                 sg->dma_length = sg->length;
114 #endif
115         }
116         return ret;
117 }
118
119 static void qib_unmap_sg(struct ib_device *dev,
120                          struct scatterlist *sg, int nents,
121                          enum dma_data_direction direction)
122 {
123         BUG_ON(!valid_dma_direction(direction));
124 }
125
126 static void qib_sync_single_for_cpu(struct ib_device *dev, u64 addr,
127                                     size_t size, enum dma_data_direction dir)
128 {
129 }
130
131 static void qib_sync_single_for_device(struct ib_device *dev, u64 addr,
132                                        size_t size,
133                                        enum dma_data_direction dir)
134 {
135 }
136
137 static void *qib_dma_alloc_coherent(struct ib_device *dev, size_t size,
138                                     u64 *dma_handle, gfp_t flag)
139 {
140         struct page *p;
141         void *addr = NULL;
142
143         p = alloc_pages(flag, get_order(size));
144         if (p)
145                 addr = page_address(p);
146         if (dma_handle)
147                 *dma_handle = (u64) addr;
148         return addr;
149 }
150
151 static void qib_dma_free_coherent(struct ib_device *dev, size_t size,
152                                   void *cpu_addr, u64 dma_handle)
153 {
154         free_pages((unsigned long) cpu_addr, get_order(size));
155 }
156
157 struct ib_dma_mapping_ops qib_dma_mapping_ops = {
158         .mapping_error = qib_mapping_error,
159         .map_single = qib_dma_map_single,
160         .unmap_single = qib_dma_unmap_single,
161         .map_page = qib_dma_map_page,
162         .unmap_page = qib_dma_unmap_page,
163         .map_sg = qib_map_sg,
164         .unmap_sg = qib_unmap_sg,
165         .sync_single_for_cpu = qib_sync_single_for_cpu,
166         .sync_single_for_device = qib_sync_single_for_device,
167         .alloc_coherent = qib_dma_alloc_coherent,
168         .free_coherent = qib_dma_free_coherent
169 };