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
|
/*
* Copyright (C) 2013 Google, Inc.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/dma-buf.h>
#include <linux/highmem.h>
#include <linux/memblock.h>
#include <linux/slab.h>
struct adf_memblock_pdata {
phys_addr_t base;
};
static struct sg_table *adf_memblock_map(struct dma_buf_attachment *attach,
enum dma_data_direction direction)
{
struct adf_memblock_pdata *pdata = attach->dmabuf->priv;
unsigned long pfn = PFN_DOWN(pdata->base);
struct page *page = pfn_to_page(pfn);
struct sg_table *table;
int ret;
table = kzalloc(sizeof(*table), GFP_KERNEL);
if (!table)
return ERR_PTR(-ENOMEM);
ret = sg_alloc_table(table, 1, GFP_KERNEL);
if (ret < 0)
goto err;
sg_set_page(table->sgl, page, attach->dmabuf->size, 0);
return table;
err:
kfree(table);
return ERR_PTR(ret);
}
static void adf_memblock_unmap(struct dma_buf_attachment *attach,
struct sg_table *table, enum dma_data_direction direction)
{
sg_free_table(table);
}
static void __init_memblock adf_memblock_release(struct dma_buf *buf)
{
struct adf_memblock_pdata *pdata = buf->priv;
int err = memblock_free(pdata->base, buf->size);
if (err < 0)
pr_warn("%s: freeing memblock failed: %d\n", __func__, err);
kfree(pdata);
}
static void *adf_memblock_do_kmap(struct dma_buf *buf, unsigned long pgoffset,
bool atomic)
{
struct adf_memblock_pdata *pdata = buf->priv;
unsigned long pfn = PFN_DOWN(pdata->base) + pgoffset;
struct page *page = pfn_to_page(pfn);
if (atomic)
return kmap_atomic(page);
else
return kmap(page);
}
static void *adf_memblock_kmap_atomic(struct dma_buf *buf,
unsigned long pgoffset)
{
return adf_memblock_do_kmap(buf, pgoffset, true);
}
static void adf_memblock_kunmap_atomic(struct dma_buf *buf,
unsigned long pgoffset, void *vaddr)
{
kunmap_atomic(vaddr);
}
static void *adf_memblock_kmap(struct dma_buf *buf, unsigned long pgoffset)
{
return adf_memblock_do_kmap(buf, pgoffset, false);
}
static void adf_memblock_kunmap(struct dma_buf *buf, unsigned long pgoffset,
void *vaddr)
{
kunmap(vaddr);
}
static int adf_memblock_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
{
struct adf_memblock_pdata *pdata = buf->priv;
return remap_pfn_range(vma, vma->vm_start, PFN_DOWN(pdata->base),
vma->vm_end - vma->vm_start, vma->vm_page_prot);
}
struct dma_buf_ops adf_memblock_ops = {
.map_dma_buf = adf_memblock_map,
.unmap_dma_buf = adf_memblock_unmap,
.release = adf_memblock_release,
.kmap_atomic = adf_memblock_kmap_atomic,
.kunmap_atomic = adf_memblock_kunmap_atomic,
.kmap = adf_memblock_kmap,
.kunmap = adf_memblock_kunmap,
.mmap = adf_memblock_mmap,
};
/**
* adf_memblock_export - export a memblock reserved area as a dma-buf
*
* @base: base physical address
* @size: memblock size
* @flags: mode flags for the dma-buf's file
*
* @base and @size must be page-aligned.
*
* Returns a dma-buf on success or ERR_PTR(-errno) on failure.
*/
struct dma_buf *adf_memblock_export(phys_addr_t base, size_t size, int flags)
{
struct adf_memblock_pdata *pdata;
struct dma_buf *buf;
if (PAGE_ALIGN(base) != base || PAGE_ALIGN(size) != size)
return ERR_PTR(-EINVAL);
pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return ERR_PTR(-ENOMEM);
pdata->base = base;
buf = dma_buf_export(pdata, &adf_memblock_ops, size, flags);
if (IS_ERR(buf))
kfree(pdata);
return buf;
}
EXPORT_SYMBOL(adf_memblock_export);
|
