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
|
/*
* Copyright (C) 2004 - 2007 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/init.h>
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <asm/cacheflush.h>
#include <asm/addrspace.h>
void *dma_generic_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp,
unsigned long attrs)
{
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.
*/
sh_sync_dma_for_device(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);
if (!WARN_ON(!dev))
*dma_handle -= PFN_PHYS(dev->dma_pfn_offset);
return ret_nocache;
}
void dma_generic_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle,
unsigned long attrs)
{
int order = get_order(size);
unsigned long pfn = (dma_handle >> PAGE_SHIFT);
int k;
if (!WARN_ON(!dev))
pfn += dev->dma_pfn_offset;
for (k = 0; k < (1 << order); k++)
__free_pages(pfn_to_page(pfn + k), 0);
iounmap(vaddr);
}
void sh_sync_dma_for_device(void *vaddr, size_t size,
enum dma_data_direction direction)
{
void *addr = sh_cacheop_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();
}
}
|
