aboutsummaryrefslogtreecommitdiff
path: root/drivers/infiniband/hw/ipath/ipath_dma.c
blob: 644c2c74e054dce8a50fa30ac64ecfd2d59654e5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
/*
 * Copyright (c) 2006 QLogic, Corporation. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/scatterlist.h>
#include <linux/gfp.h>
#include <rdma/ib_verbs.h>

#include "ipath_verbs.h"

#define BAD_DMA_ADDRESS ((u64) 0)

/*
 * The following functions implement driver specific replacements
 * for the ib_dma_*() functions.
 *
 * These functions return kernel virtual addresses instead of
 * device bus addresses since the driver uses the CPU to copy
 * data instead of using hardware DMA.
 */

static int ipath_mapping_error(struct ib_device *dev, u64 dma_addr)
{
	return dma_addr == BAD_DMA_ADDRESS;
}

static u64 ipath_dma_map_single(struct ib_device *dev,
			        void *cpu_addr, size_t size,
			        enum dma_data_direction direction)
{
	BUG_ON(!valid_dma_direction(direction));
	return (u64) cpu_addr;
}

static void ipath_dma_unmap_single(struct ib_device *dev,
				   u64 addr, size_t size,
				   enum dma_data_direction direction)
{
	BUG_ON(!valid_dma_direction(direction));
}

static u64 ipath_dma_map_page(struct ib_device *dev,
			      struct page *page,
			      unsigned long offset,
			      size_t size,
			      enum dma_data_direction direction)
{
	u64 addr;

	BUG_ON(!valid_dma_direction(direction));

	if (offset + size > PAGE_SIZE) {
		addr = BAD_DMA_ADDRESS;
		goto done;
	}

	addr = (u64) page_address(page);
	if (addr)
		addr += offset;
	/* TODO: handle highmem pages */

done:
	return addr;
}

static void ipath_dma_unmap_page(struct ib_device *dev,
				 u64 addr, size_t size,
				 enum dma_data_direction direction)
{
	BUG_ON(!valid_dma_direction(direction));
}

static int ipath_map_sg(struct ib_device *dev, struct scatterlist *sgl,
			int nents, enum dma_data_direction direction)
{
	struct scatterlist *sg;
	u64 addr;
	int i;
	int ret = nents;

	BUG_ON(!valid_dma_direction(direction));

	for_each_sg(sgl, sg, nents, i) {
		addr = (u64) page_address(sg_page(sg));
		/* TODO: handle highmem pages */
		if (!addr) {
			ret = 0;
			break;
		}
	}
	return ret;
}

static void ipath_unmap_sg(struct ib_device *dev,
			   struct scatterlist *sg, int nents,
			   enum dma_data_direction direction)
{
	BUG_ON(!valid_dma_direction(direction));
}

static u64 ipath_sg_dma_address(struct ib_device *dev, struct scatterlist *sg)
{
	u64 addr = (u64) page_address(sg_page(sg));

	if (addr)
		addr += sg->offset;
	return addr;
}

static unsigned int ipath_sg_dma_len(struct ib_device *dev,
				     struct scatterlist *sg)
{
	return sg->length;
}

static void ipath_sync_single_for_cpu(struct ib_device *dev,
				      u64 addr,
				      size_t size,
				      enum dma_data_direction dir)
{
}

static void ipath_sync_single_for_device(struct ib_device *dev,
					 u64 addr,
					 size_t size,
					 enum dma_data_direction dir)
{
}

static void *ipath_dma_alloc_coherent(struct ib_device *dev, size_t size,
				      u64 *dma_handle, gfp_t flag)
{
	struct page *p;
	void *addr = NULL;

	p = alloc_pages(flag, get_order(size));
	if (p)
		addr = page_address(p);
	if (dma_handle)
		*dma_handle = (u64) addr;
	return addr;
}

static void ipath_dma_free_coherent(struct ib_device *dev, size_t size,
				    void *cpu_addr, u64 dma_handle)
{
	free_pages((unsigned long) cpu_addr, get_order(size));
}

struct ib_dma_mapping_ops ipath_dma_mapping_ops = {
	ipath_mapping_error,
	ipath_dma_map_single,
	ipath_dma_unmap_single,
	ipath_dma_map_page,
	ipath_dma_unmap_page,
	ipath_map_sg,
	ipath_unmap_sg,
	ipath_sg_dma_address,
	ipath_sg_dma_len,
	ipath_sync_single_for_cpu,
	ipath_sync_single_for_device,
	ipath_dma_alloc_coherent,
	ipath_dma_free_coherent
};