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
|
/*
* Copyright (C) 2009-2010 PetaLogix
* Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
*
* Provide default implementations of the DMA mapping callbacks for
* directly mapped busses.
*/
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/gfp.h>
#include <linux/dma-debug.h>
#include <asm/bug.h>
#include <asm/cacheflush.h>
/*
* Generic direct DMA implementation
*
* This implementation supports a per-device offset that can be applied if
* the address at which memory is visible to devices is not 0. Platform code
* can set archdata.dma_data to an unsigned long holding the offset. By
* default the offset is PCI_DRAM_OFFSET.
*/
static inline void __dma_sync_page(unsigned long paddr, unsigned long offset,
size_t size, enum dma_data_direction direction)
{
switch (direction) {
case DMA_TO_DEVICE:
flush_dcache_range(paddr + offset, paddr + offset + size);
break;
case DMA_FROM_DEVICE:
invalidate_dcache_range(paddr + offset, paddr + offset + size);
break;
default:
BUG();
}
}
static unsigned long get_dma_direct_offset(struct device *dev)
{
if (likely(dev))
return (unsigned long)dev->archdata.dma_data;
return PCI_DRAM_OFFSET; /* FIXME Not sure if is correct */
}
#define NOT_COHERENT_CACHE
static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag)
{
#ifdef NOT_COHERENT_CACHE
return consistent_alloc(flag, size, dma_handle);
#else
void *ret;
struct page *page;
int node = dev_to_node(dev);
/* ignore region specifiers */
flag &= ~(__GFP_HIGHMEM);
page = alloc_pages_node(node, flag, get_order(size));
if (page == NULL)
return NULL;
ret = page_address(page);
memset(ret, 0, size);
*dma_handle = virt_to_phys(ret) + get_dma_direct_offset(dev);
return ret;
#endif
}
static void dma_direct_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle)
{
#ifdef NOT_COHERENT_CACHE
consistent_free(vaddr);
#else
free_pages((unsigned long)vaddr, get_order(size));
#endif
}
static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction direction,
struct dma_attrs *attrs)
{
struct scatterlist *sg;
int i;
/* FIXME this part of code is untested */
for_each_sg(sgl, sg, nents, i) {
sg->dma_address = sg_phys(sg) + get_dma_direct_offset(dev);
sg->dma_length = sg->length;
__dma_sync_page(page_to_phys(sg_page(sg)), sg->offset,
sg->length, direction);
}
return nents;
}
static void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction direction,
struct dma_attrs *attrs)
{
}
static int dma_direct_dma_supported(struct device *dev, u64 mask)
{
return 1;
}
static inline dma_addr_t dma_direct_map_page(struct device *dev,
struct page *page,
unsigned long offset,
size_t size,
enum dma_data_direction direction,
struct dma_attrs *attrs)
{
__dma_sync_page(page_to_phys(page), offset, size, direction);
return page_to_phys(page) + offset + get_dma_direct_offset(dev);
}
static inline void dma_direct_unmap_page(struct device *dev,
dma_addr_t dma_address,
size_t size,
enum dma_data_direction direction,
struct dma_attrs *attrs)
{
/* There is not necessary to do cache cleanup
*
* phys_to_virt is here because in __dma_sync_page is __virt_to_phys and
* dma_address is physical address
*/
__dma_sync_page(dma_address, 0 , size, direction);
}
struct dma_map_ops dma_direct_ops = {
.alloc_coherent = dma_direct_alloc_coherent,
.free_coherent = dma_direct_free_coherent,
.map_sg = dma_direct_map_sg,
.unmap_sg = dma_direct_unmap_sg,
.dma_supported = dma_direct_dma_supported,
.map_page = dma_direct_map_page,
.unmap_page = dma_direct_unmap_page,
};
EXPORT_SYMBOL(dma_direct_ops);
/* Number of entries preallocated for DMA-API debugging */
#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
static int __init dma_init(void)
{
dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
return 0;
}
fs_initcall(dma_init);
|
