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
|
/*
* arch/sh/mm/consistent.c
*
* Copyright (C) 2004 Paul Mundt
*
* 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/dma-mapping.h>
#include <asm/cacheflush.h>
#include <asm/addrspace.h>
#include <asm/io.h>
void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *handle)
{
struct page *page, *end, *free;
void *ret;
int order;
size = PAGE_ALIGN(size);
order = get_order(size);
page = alloc_pages(gfp, order);
if (!page)
return NULL;
split_page(page, order);
ret = page_address(page);
memset(ret, 0, size);
*handle = virt_to_phys(ret);
/*
* We must flush the cache before we pass it on to the device
*/
dma_cache_wback_inv(ret, size);
page = virt_to_page(ret);
free = page + (size >> PAGE_SHIFT);
end = page + (1 << order);
while (++page < end) {
/* Free any unused pages */
if (page >= free) {
__free_page(page);
}
}
return P2SEGADDR(ret);
}
void consistent_free(void *vaddr, size_t size)
{
unsigned long addr = P1SEGADDR((unsigned long)vaddr);
struct page *page=virt_to_page(addr);
int num_pages=(size+PAGE_SIZE-1) >> PAGE_SHIFT;
int i;
for(i=0;i<num_pages;i++) {
__free_page((page+i));
}
}
void consistent_sync(void *vaddr, size_t size, int direction)
{
void * p1addr = (void*) P1SEGADDR((unsigned long)vaddr);
switch (direction) {
case DMA_FROM_DEVICE: /* invalidate only */
dma_cache_inv(p1addr, size);
break;
case DMA_TO_DEVICE: /* writeback only */
dma_cache_wback(p1addr, size);
break;
case DMA_BIDIRECTIONAL: /* writeback and invalidate */
dma_cache_wback_inv(p1addr, size);
break;
default:
BUG();
}
}
EXPORT_SYMBOL(consistent_alloc);
EXPORT_SYMBOL(consistent_free);
EXPORT_SYMBOL(consistent_sync);
|
