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
|
/*
* arch/sh/mm/consistent.c
*
* Copyright (C) 2004 - 2007 Paul Mundt
*
* Declared coherent memory functions based on arch/x86/kernel/pci-dma_32.c
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/dma-debug.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/gfp.h>
#include <asm/cacheflush.h>
#include <asm/addrspace.h>
#define PREALLOC_DMA_DEBUG_ENTRIES 4096
struct dma_map_ops *dma_ops;
EXPORT_SYMBOL(dma_ops);
static int __init dma_init(void)
{
dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
return 0;
}
fs_initcall(dma_init);
void *dma_generic_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp)
{
void *ret, *ret_nocache;
int order = get_order(size);
gfp |= __GFP_ZERO;
ret = (void *)__get_free_pages(gfp, order);
if (!ret)
return NULL;
/*
* Pages from the page allocator may have data present in
* cache. So flush the cache before using uncached memory.
*/
dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL);
ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size);
if (!ret_nocache) {
free_pages((unsigned long)ret, order);
return NULL;
}
split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order);
*dma_handle = virt_to_phys(ret);
return ret_nocache;
}
void dma_generic_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle)
{
int order = get_order(size);
unsigned long pfn = dma_handle >> PAGE_SHIFT;
int k;
for (k = 0; k < (1 << order); k++)
__free_pages(pfn_to_page(pfn + k), 0);
iounmap(vaddr);
}
void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
enum dma_data_direction direction)
{
void *addr;
addr = __in_29bit_mode() ?
(void *)CAC_ADDR((unsigned long)vaddr) : vaddr;
switch (direction) {
case DMA_FROM_DEVICE: /* invalidate only */
__flush_invalidate_region(addr, size);
break;
case DMA_TO_DEVICE: /* writeback only */
__flush_wback_region(addr, size);
break;
case DMA_BIDIRECTIONAL: /* writeback and invalidate */
__flush_purge_region(addr, size);
break;
default:
BUG();
}
}
EXPORT_SYMBOL(dma_cache_sync);
static int __init memchunk_setup(char *str)
{
return 1; /* accept anything that begins with "memchunk." */
}
__setup("memchunk.", memchunk_setup);
static void __init memchunk_cmdline_override(char *name, unsigned long *sizep)
{
char *p = boot_command_line;
int k = strlen(name);
while ((p = strstr(p, "memchunk."))) {
p += 9; /* strlen("memchunk.") */
if (!strncmp(name, p, k) && p[k] == '=') {
p += k + 1;
*sizep = memparse(p, NULL);
pr_info("%s: forcing memory chunk size to 0x%08lx\n",
name, *sizep);
break;
}
}
}
int __init platform_resource_setup_memory(struct platform_device *pdev,
char *name, unsigned long memsize)
{
struct resource *r;
dma_addr_t dma_handle;
void *buf;
r = pdev->resource + pdev->num_resources - 1;
if (r->flags) {
pr_warning("%s: unable to find empty space for resource\n",
name);
return -EINVAL;
}
memchunk_cmdline_override(name, &memsize);
if (!memsize)
return 0;
buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL);
if (!buf) {
pr_warning("%s: unable to allocate memory\n", name);
return -ENOMEM;
}
memset(buf, 0, memsize);
r->flags = IORESOURCE_MEM;
r->start = dma_handle;
r->end = r->start + memsize - 1;
r->name = name;
return 0;
}
|
