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
|
/*
* Copyright (C) 2004-2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/dma-mapping.h>
#include <linux/gfp.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/device.h>
#include <linux/scatterlist.h>
#include <asm/processor.h>
#include <asm/cacheflush.h>
#include <asm/io.h>
#include <asm/addrspace.h>
void dma_cache_sync(struct device *dev, void *vaddr, size_t size, int direction)
{
/*
* No need to sync an uncached area
*/
if (PXSEG(vaddr) == P2SEG)
return;
switch (direction) {
case DMA_FROM_DEVICE: /* invalidate only */
invalidate_dcache_region(vaddr, size);
break;
case DMA_TO_DEVICE: /* writeback only */
clean_dcache_region(vaddr, size);
break;
case DMA_BIDIRECTIONAL: /* writeback and invalidate */
flush_dcache_region(vaddr, size);
break;
default:
BUG();
}
}
EXPORT_SYMBOL(dma_cache_sync);
static struct page *__dma_alloc(struct device *dev, size_t size,
dma_addr_t *handle, gfp_t gfp)
{
struct page *page, *free, *end;
int order;
/* Following is a work-around (a.k.a. hack) to prevent pages
* with __GFP_COMP being passed to split_page() which cannot
* handle them. The real problem is that this flag probably
* should be 0 on AVR32 as it is not supported on this
* platform--see CONFIG_HUGETLB_PAGE. */
gfp &= ~(__GFP_COMP);
size = PAGE_ALIGN(size);
order = get_order(size);
page = alloc_pages(gfp, order);
if (!page)
return NULL;
split_page(page, order);
/*
* When accessing physical memory with valid cache data, we
* get a cache hit even if the virtual memory region is marked
* as uncached.
*
* Since the memory is newly allocated, there is no point in
* doing a writeback. If the previous owner cares, he should
* have flushed the cache before releasing the memory.
*/
invalidate_dcache_region(phys_to_virt(page_to_phys(page)), size);
*handle = page_to_bus(page);
free = page + (size >> PAGE_SHIFT);
end = page + (1 << order);
/*
* Free any unused pages
*/
while (free < end) {
__free_page(free);
free++;
}
return page;
}
static void __dma_free(struct device *dev, size_t size,
struct page *page, dma_addr_t handle)
{
struct page *end = page + (PAGE_ALIGN(size) >> PAGE_SHIFT);
while (page < end)
__free_page(page++);
}
static void *avr32_dma_alloc(struct device *dev, size_t size,
dma_addr_t *handle, gfp_t gfp, unsigned long attrs)
{
struct page *page;
dma_addr_t phys;
page = __dma_alloc(dev, size, handle, gfp);
if (!page)
return NULL;
phys = page_to_phys(page);
if (attrs & DMA_ATTR_WRITE_COMBINE) {
/* Now, map the page into P3 with write-combining turned on */
*handle = phys;
return __ioremap(phys, size, _PAGE_BUFFER);
} else {
return phys_to_uncached(phys);
}
}
static void avr32_dma_free(struct device *dev, size_t size,
void *cpu_addr, dma_addr_t handle, unsigned long attrs)
{
struct page *page;
if (attrs & DMA_ATTR_WRITE_COMBINE) {
iounmap(cpu_addr);
page = phys_to_page(handle);
} else {
void *addr = phys_to_cached(uncached_to_phys(cpu_addr));
pr_debug("avr32_dma_free addr %p (phys %08lx) size %u\n",
cpu_addr, (unsigned long)handle, (unsigned)size);
BUG_ON(!virt_addr_valid(addr));
page = virt_to_page(addr);
}
__dma_free(dev, size, page, handle);
}
static dma_addr_t avr32_dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction direction, unsigned long attrs)
{
void *cpu_addr = page_address(page) + offset;
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
dma_cache_sync(dev, cpu_addr, size, direction);
return virt_to_bus(cpu_addr);
}
static int avr32_dma_map_sg(struct device *dev, struct scatterlist *sglist,
int nents, enum dma_data_direction direction,
unsigned long attrs)
{
int i;
struct scatterlist *sg;
for_each_sg(sglist, sg, nents, i) {
char *virt;
sg->dma_address = page_to_bus(sg_page(sg)) + sg->offset;
virt = sg_virt(sg);
if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
continue;
dma_cache_sync(dev, virt, sg->length, direction);
}
return nents;
}
static void avr32_dma_sync_single_for_device(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction direction)
{
dma_cache_sync(dev, bus_to_virt(dma_handle), size, direction);
}
static void avr32_dma_sync_sg_for_device(struct device *dev,
struct scatterlist *sglist, int nents,
enum dma_data_direction direction)
{
int i;
struct scatterlist *sg;
for_each_sg(sglist, sg, nents, i)
dma_cache_sync(dev, sg_virt(sg), sg->length, direction);
}
struct dma_map_ops avr32_dma_ops = {
.alloc = avr32_dma_alloc,
.free = avr32_dma_free,
.map_page = avr32_dma_map_page,
.map_sg = avr32_dma_map_sg,
.sync_single_for_device = avr32_dma_sync_single_for_device,
.sync_sg_for_device = avr32_dma_sync_sg_for_device,
};
EXPORT_SYMBOL(avr32_dma_ops);
|
