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
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
|
/*
* 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 <linux/export.h>
#include <linux/bug.h>
#define NOT_COHERENT_CACHE
static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag,
struct dma_attrs *attrs)
{
#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);
return ret;
#endif
}
static void dma_direct_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle,
struct dma_attrs *attrs)
{
#ifdef NOT_COHERENT_CACHE
consistent_free(size, 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);
__dma_sync(page_to_phys(sg_page(sg)) + sg->offset,
sg->length, direction);
}
return nents;
}
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_to_phys(page) + offset, size, direction);
return page_to_phys(page) + offset;
}
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(dma_address, size, direction);
}
static inline void
dma_direct_sync_single_for_cpu(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction direction)
{
/*
* It's pointless to flush the cache as the memory segment
* is given to the CPU
*/
if (direction == DMA_FROM_DEVICE)
__dma_sync(dma_handle, size, direction);
}
static inline void
dma_direct_sync_single_for_device(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction direction)
{
/*
* It's pointless to invalidate the cache if the device isn't
* supposed to write to the relevant region
*/
if (direction == DMA_TO_DEVICE)
__dma_sync(dma_handle, size, direction);
}
static inline void
dma_direct_sync_sg_for_cpu(struct device *dev,
struct scatterlist *sgl, int nents,
enum dma_data_direction direction)
{
struct scatterlist *sg;
int i;
/* FIXME this part of code is untested */
if (direction == DMA_FROM_DEVICE)
for_each_sg(sgl, sg, nents, i)
__dma_sync(sg->dma_address, sg->length, direction);
}
static inline void
dma_direct_sync_sg_for_device(struct device *dev,
struct scatterlist *sgl, int nents,
enum dma_data_direction direction)
{
struct scatterlist *sg;
int i;
/* FIXME this part of code is untested */
if (direction == DMA_TO_DEVICE)
for_each_sg(sgl, sg, nents, i)
__dma_sync(sg->dma_address, sg->length, direction);
}
int dma_direct_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t handle, size_t size,
struct dma_attrs *attrs)
{
#ifdef CONFIG_MMU
unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned long off = vma->vm_pgoff;
unsigned long pfn;
if (off >= count || user_count > (count - off))
return -ENXIO;
#ifdef NOT_COHERENT_CACHE
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
pfn = consistent_virt_to_pfn(cpu_addr);
#else
pfn = virt_to_pfn(cpu_addr);
#endif
return remap_pfn_range(vma, vma->vm_start, pfn + off,
vma->vm_end - vma->vm_start, vma->vm_page_prot);
#else
return -ENXIO;
#endif
}
struct dma_map_ops dma_direct_ops = {
.alloc = dma_direct_alloc_coherent,
.free = dma_direct_free_coherent,
.mmap = dma_direct_mmap_coherent,
.map_sg = dma_direct_map_sg,
.dma_supported = dma_direct_dma_supported,
.map_page = dma_direct_map_page,
.unmap_page = dma_direct_unmap_page,
.sync_single_for_cpu = dma_direct_sync_single_for_cpu,
.sync_single_for_device = dma_direct_sync_single_for_device,
.sync_sg_for_cpu = dma_direct_sync_sg_for_cpu,
.sync_sg_for_device = dma_direct_sync_sg_for_device,
};
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);
|
