Commit | Line | Data |
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3c18ff06 PO |
1 | /* |
2 | * videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2 | |
3 | * | |
4 | * Copyright (C) 2010 Samsung Electronics | |
5 | * | |
95072084 | 6 | * Author: Pawel Osciak <pawel@osciak.com> |
3c18ff06 PO |
7 | * |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation. | |
11 | */ | |
12 | ||
13 | #include <linux/module.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/vmalloc.h> | |
17 | ||
18 | #include <media/videobuf2-core.h> | |
19 | #include <media/videobuf2-memops.h> | |
20 | ||
21 | struct vb2_vmalloc_buf { | |
22 | void *vaddr; | |
23 | unsigned long size; | |
24 | atomic_t refcount; | |
25 | struct vb2_vmarea_handler handler; | |
26 | }; | |
27 | ||
28 | static void vb2_vmalloc_put(void *buf_priv); | |
29 | ||
30 | static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size) | |
31 | { | |
32 | struct vb2_vmalloc_buf *buf; | |
33 | ||
34 | buf = kzalloc(sizeof *buf, GFP_KERNEL); | |
35 | if (!buf) | |
36 | return NULL; | |
37 | ||
38 | buf->size = size; | |
39 | buf->vaddr = vmalloc_user(buf->size); | |
40 | buf->handler.refcount = &buf->refcount; | |
41 | buf->handler.put = vb2_vmalloc_put; | |
42 | buf->handler.arg = buf; | |
43 | ||
44 | if (!buf->vaddr) { | |
45 | printk(KERN_ERR "vmalloc of size %ld failed\n", buf->size); | |
46 | kfree(buf); | |
47 | return NULL; | |
48 | } | |
49 | ||
50 | atomic_inc(&buf->refcount); | |
51 | printk(KERN_DEBUG "Allocated vmalloc buffer of size %ld at vaddr=%p\n", | |
52 | buf->size, buf->vaddr); | |
53 | ||
54 | return buf; | |
55 | } | |
56 | ||
57 | static void vb2_vmalloc_put(void *buf_priv) | |
58 | { | |
59 | struct vb2_vmalloc_buf *buf = buf_priv; | |
60 | ||
61 | if (atomic_dec_and_test(&buf->refcount)) { | |
62 | printk(KERN_DEBUG "%s: Freeing vmalloc mem at vaddr=%p\n", | |
63 | __func__, buf->vaddr); | |
64 | vfree(buf->vaddr); | |
65 | kfree(buf); | |
66 | } | |
67 | } | |
68 | ||
69 | static void *vb2_vmalloc_vaddr(void *buf_priv) | |
70 | { | |
71 | struct vb2_vmalloc_buf *buf = buf_priv; | |
72 | ||
73 | BUG_ON(!buf); | |
74 | ||
75 | if (!buf->vaddr) { | |
76 | printk(KERN_ERR "Address of an unallocated plane requested\n"); | |
77 | return NULL; | |
78 | } | |
79 | ||
80 | return buf->vaddr; | |
81 | } | |
82 | ||
83 | static unsigned int vb2_vmalloc_num_users(void *buf_priv) | |
84 | { | |
85 | struct vb2_vmalloc_buf *buf = buf_priv; | |
86 | return atomic_read(&buf->refcount); | |
87 | } | |
88 | ||
89 | static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma) | |
90 | { | |
91 | struct vb2_vmalloc_buf *buf = buf_priv; | |
92 | int ret; | |
93 | ||
94 | if (!buf) { | |
95 | printk(KERN_ERR "No memory to map\n"); | |
96 | return -EINVAL; | |
97 | } | |
98 | ||
99 | ret = remap_vmalloc_range(vma, buf->vaddr, 0); | |
100 | if (ret) { | |
101 | printk(KERN_ERR "Remapping vmalloc memory, error: %d\n", ret); | |
102 | return ret; | |
103 | } | |
104 | ||
105 | /* | |
106 | * Make sure that vm_areas for 2 buffers won't be merged together | |
107 | */ | |
108 | vma->vm_flags |= VM_DONTEXPAND; | |
109 | ||
110 | /* | |
111 | * Use common vm_area operations to track buffer refcount. | |
112 | */ | |
113 | vma->vm_private_data = &buf->handler; | |
114 | vma->vm_ops = &vb2_common_vm_ops; | |
115 | ||
116 | vma->vm_ops->open(vma); | |
117 | ||
118 | return 0; | |
119 | } | |
120 | ||
121 | const struct vb2_mem_ops vb2_vmalloc_memops = { | |
122 | .alloc = vb2_vmalloc_alloc, | |
123 | .put = vb2_vmalloc_put, | |
124 | .vaddr = vb2_vmalloc_vaddr, | |
125 | .mmap = vb2_vmalloc_mmap, | |
126 | .num_users = vb2_vmalloc_num_users, | |
127 | }; | |
128 | EXPORT_SYMBOL_GPL(vb2_vmalloc_memops); | |
129 | ||
130 | MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2"); | |
95072084 | 131 | MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>"); |
3c18ff06 | 132 | MODULE_LICENSE("GPL"); |