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
|
/*
* File: arch/blackfin/kernel/dma-mapping.c
* Based on:
* Author:
*
* Created:
* Description: Dynamic DMA mapping support.
*
* Modified:
* Copyright 2004-2006 Analog Devices Inc.
*
* Bugs: Enter bugs at http://blackfin.uclinux.org/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see the file COPYING, or write
* to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/bootmem.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <asm/bfin-global.h>
static spinlock_t dma_page_lock;
static unsigned int *dma_page;
static unsigned int dma_pages;
static unsigned long dma_base;
static unsigned long dma_size;
static unsigned int dma_initialized;
void dma_alloc_init(unsigned long start, unsigned long end)
{
spin_lock_init(&dma_page_lock);
dma_initialized = 0;
dma_page = (unsigned int *)__get_free_page(GFP_KERNEL);
memset(dma_page, 0, PAGE_SIZE);
dma_base = PAGE_ALIGN(start);
dma_size = PAGE_ALIGN(end) - PAGE_ALIGN(start);
dma_pages = dma_size >> PAGE_SHIFT;
memset((void *)dma_base, 0, DMA_UNCACHED_REGION);
dma_initialized = 1;
printk(KERN_INFO "%s: dma_page @ 0x%p - %d pages at 0x%08lx\n", __FUNCTION__,
dma_page, dma_pages, dma_base);
}
static inline unsigned int get_pages(size_t size)
{
return ((size - 1) >> PAGE_SHIFT) + 1;
}
static unsigned long __alloc_dma_pages(unsigned int pages)
{
unsigned long ret = 0, flags;
int i, count = 0;
if (dma_initialized == 0)
dma_alloc_init(_ramend - DMA_UNCACHED_REGION, _ramend);
spin_lock_irqsave(&dma_page_lock, flags);
for (i = 0; i < dma_pages;) {
if (dma_page[i++] == 0) {
if (++count == pages) {
while (count--)
dma_page[--i] = 1;
ret = dma_base + (i << PAGE_SHIFT);
break;
}
} else
count = 0;
}
spin_unlock_irqrestore(&dma_page_lock, flags);
return ret;
}
static void __free_dma_pages(unsigned long addr, unsigned int pages)
{
unsigned long page = (addr - dma_base) >> PAGE_SHIFT;
unsigned long flags;
int i;
if ((page + pages) > dma_pages) {
printk(KERN_ERR "%s: freeing outside range.\n", __FUNCTION__);
BUG();
}
spin_lock_irqsave(&dma_page_lock, flags);
for (i = page; i < page + pages; i++) {
dma_page[i] = 0;
}
spin_unlock_irqrestore(&dma_page_lock, flags);
}
void *dma_alloc_coherent(struct device *dev, size_t size,
dma_addr_t * dma_handle, gfp_t gfp)
{
void *ret;
ret = (void *)__alloc_dma_pages(get_pages(size));
if (ret) {
memset(ret, 0, size);
*dma_handle = virt_to_phys(ret);
}
return ret;
}
EXPORT_SYMBOL(dma_alloc_coherent);
void
dma_free_coherent(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle)
{
__free_dma_pages((unsigned long)vaddr, get_pages(size));
}
EXPORT_SYMBOL(dma_free_coherent);
/*
* Dummy functions defined for some existing drivers
*/
dma_addr_t
dma_map_single(struct device *dev, void *ptr, size_t size,
enum dma_data_direction direction)
{
BUG_ON(direction == DMA_NONE);
invalidate_dcache_range((unsigned long)ptr,
(unsigned long)ptr + size);
return (dma_addr_t) ptr;
}
EXPORT_SYMBOL(dma_map_single);
int
dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction direction)
{
int i;
BUG_ON(direction == DMA_NONE);
for (i = 0; i < nents; i++, sg++) {
sg->dma_address = (dma_addr_t) sg_virt(sg);
invalidate_dcache_range(sg_dma_address(sg),
sg_dma_address(sg) +
sg_dma_len(sg));
}
return nents;
}
EXPORT_SYMBOL(dma_map_sg);
void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
enum dma_data_direction direction)
{
BUG_ON(direction == DMA_NONE);
}
EXPORT_SYMBOL(dma_unmap_single);
void dma_unmap_sg(struct device *dev, struct scatterlist *sg,
int nhwentries, enum dma_data_direction direction)
{
BUG_ON(direction == DMA_NONE);
}
EXPORT_SYMBOL(dma_unmap_sg);
|
