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
|
// SPDX-License-Identifier: GPL-2.0
/*
* DMABUF CMA heap exporter
*
* Copyright (C) 2012, 2019 Linaro Ltd.
* Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
*/
#include <linux/cma.h>
#include <linux/device.h>
#include <linux/dma-buf.h>
#include <linux/dma-heap.h>
#include <linux/dma-map-ops.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/highmem.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/scatterlist.h>
#include <linux/sched/signal.h>
#include "heap-helpers.h"
struct cma_heap {
struct dma_heap *heap;
struct cma *cma;
};
static void cma_heap_free(struct heap_helper_buffer *buffer)
{
struct cma_heap *cma_heap = dma_heap_get_drvdata(buffer->heap);
unsigned long nr_pages = buffer->pagecount;
struct page *cma_pages = buffer->priv_virt;
/* free page list */
kfree(buffer->pages);
/* release memory */
cma_release(cma_heap->cma, cma_pages, nr_pages);
kfree(buffer);
}
/* dmabuf heap CMA operations functions */
static int cma_heap_allocate(struct dma_heap *heap,
unsigned long len,
unsigned long fd_flags,
unsigned long heap_flags)
{
struct cma_heap *cma_heap = dma_heap_get_drvdata(heap);
struct heap_helper_buffer *helper_buffer;
struct page *cma_pages;
size_t size = PAGE_ALIGN(len);
unsigned long nr_pages = size >> PAGE_SHIFT;
unsigned long align = get_order(size);
struct dma_buf *dmabuf;
int ret = -ENOMEM;
pgoff_t pg;
if (align > CONFIG_CMA_ALIGNMENT)
align = CONFIG_CMA_ALIGNMENT;
helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
if (!helper_buffer)
return -ENOMEM;
init_heap_helper_buffer(helper_buffer, cma_heap_free);
helper_buffer->heap = heap;
helper_buffer->size = len;
cma_pages = cma_alloc(cma_heap->cma, nr_pages, align, false);
if (!cma_pages)
goto free_buf;
if (PageHighMem(cma_pages)) {
unsigned long nr_clear_pages = nr_pages;
struct page *page = cma_pages;
while (nr_clear_pages > 0) {
void *vaddr = kmap_atomic(page);
memset(vaddr, 0, PAGE_SIZE);
kunmap_atomic(vaddr);
/*
* Avoid wasting time zeroing memory if the process
* has been killed by by SIGKILL
*/
if (fatal_signal_pending(current))
goto free_cma;
page++;
nr_clear_pages--;
}
} else {
memset(page_address(cma_pages), 0, size);
}
helper_buffer->pagecount = nr_pages;
helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
sizeof(*helper_buffer->pages),
GFP_KERNEL);
if (!helper_buffer->pages) {
ret = -ENOMEM;
goto free_cma;
}
for (pg = 0; pg < helper_buffer->pagecount; pg++)
helper_buffer->pages[pg] = &cma_pages[pg];
/* create the dmabuf */
dmabuf = heap_helper_export_dmabuf(helper_buffer, fd_flags);
if (IS_ERR(dmabuf)) {
ret = PTR_ERR(dmabuf);
goto free_pages;
}
helper_buffer->dmabuf = dmabuf;
helper_buffer->priv_virt = cma_pages;
ret = dma_buf_fd(dmabuf, fd_flags);
if (ret < 0) {
dma_buf_put(dmabuf);
/* just return, as put will call release and that will free */
return ret;
}
return ret;
free_pages:
kfree(helper_buffer->pages);
free_cma:
cma_release(cma_heap->cma, cma_pages, nr_pages);
free_buf:
kfree(helper_buffer);
return ret;
}
static const struct dma_heap_ops cma_heap_ops = {
.allocate = cma_heap_allocate,
};
static int __add_cma_heap(struct cma *cma, void *data)
{
struct cma_heap *cma_heap;
struct dma_heap_export_info exp_info;
cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
if (!cma_heap)
return -ENOMEM;
cma_heap->cma = cma;
exp_info.name = cma_get_name(cma);
exp_info.ops = &cma_heap_ops;
exp_info.priv = cma_heap;
cma_heap->heap = dma_heap_add(&exp_info);
if (IS_ERR(cma_heap->heap)) {
int ret = PTR_ERR(cma_heap->heap);
kfree(cma_heap);
return ret;
}
return 0;
}
static int add_default_cma_heap(void)
{
struct cma *default_cma = dev_get_cma_area(NULL);
int ret = 0;
if (default_cma)
ret = __add_cma_heap(default_cma, NULL);
return ret;
}
module_init(add_default_cma_heap);
MODULE_DESCRIPTION("DMA-BUF CMA Heap");
MODULE_LICENSE("GPL v2");
|
