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1a758d4e PO |
1 | /* |
2 | * videobuf2-dma-contig.c - DMA contig memory allocator for videobuf2 | |
3 | * | |
4 | * Copyright (C) 2010 Samsung Electronics | |
5 | * | |
95072084 | 6 | * Author: Pawel Osciak <pawel@osciak.com> |
1a758d4e 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/slab.h> | |
15 | #include <linux/dma-mapping.h> | |
16 | ||
17 | #include <media/videobuf2-core.h> | |
18 | #include <media/videobuf2-memops.h> | |
19 | ||
20 | struct vb2_dc_conf { | |
21 | struct device *dev; | |
22 | }; | |
23 | ||
24 | struct vb2_dc_buf { | |
25 | struct vb2_dc_conf *conf; | |
26 | void *vaddr; | |
27 | dma_addr_t paddr; | |
28 | unsigned long size; | |
29 | struct vm_area_struct *vma; | |
30 | atomic_t refcount; | |
31 | struct vb2_vmarea_handler handler; | |
32 | }; | |
33 | ||
34 | static void vb2_dma_contig_put(void *buf_priv); | |
35 | ||
36 | static void *vb2_dma_contig_alloc(void *alloc_ctx, unsigned long size) | |
37 | { | |
38 | struct vb2_dc_conf *conf = alloc_ctx; | |
39 | struct vb2_dc_buf *buf; | |
40 | ||
41 | buf = kzalloc(sizeof *buf, GFP_KERNEL); | |
42 | if (!buf) | |
43 | return ERR_PTR(-ENOMEM); | |
44 | ||
45 | buf->vaddr = dma_alloc_coherent(conf->dev, size, &buf->paddr, | |
46 | GFP_KERNEL); | |
47 | if (!buf->vaddr) { | |
48 | dev_err(conf->dev, "dma_alloc_coherent of size %ld failed\n", | |
99a41771 | 49 | size); |
1a758d4e PO |
50 | kfree(buf); |
51 | return ERR_PTR(-ENOMEM); | |
52 | } | |
53 | ||
54 | buf->conf = conf; | |
55 | buf->size = size; | |
56 | ||
57 | buf->handler.refcount = &buf->refcount; | |
58 | buf->handler.put = vb2_dma_contig_put; | |
59 | buf->handler.arg = buf; | |
60 | ||
61 | atomic_inc(&buf->refcount); | |
62 | ||
63 | return buf; | |
64 | } | |
65 | ||
66 | static void vb2_dma_contig_put(void *buf_priv) | |
67 | { | |
68 | struct vb2_dc_buf *buf = buf_priv; | |
69 | ||
70 | if (atomic_dec_and_test(&buf->refcount)) { | |
71 | dma_free_coherent(buf->conf->dev, buf->size, buf->vaddr, | |
72 | buf->paddr); | |
73 | kfree(buf); | |
74 | } | |
75 | } | |
76 | ||
77 | static void *vb2_dma_contig_cookie(void *buf_priv) | |
78 | { | |
79 | struct vb2_dc_buf *buf = buf_priv; | |
80 | ||
472af2b0 | 81 | return &buf->paddr; |
1a758d4e PO |
82 | } |
83 | ||
84 | static void *vb2_dma_contig_vaddr(void *buf_priv) | |
85 | { | |
86 | struct vb2_dc_buf *buf = buf_priv; | |
87 | if (!buf) | |
88 | return 0; | |
89 | ||
90 | return buf->vaddr; | |
91 | } | |
92 | ||
93 | static unsigned int vb2_dma_contig_num_users(void *buf_priv) | |
94 | { | |
95 | struct vb2_dc_buf *buf = buf_priv; | |
96 | ||
97 | return atomic_read(&buf->refcount); | |
98 | } | |
99 | ||
100 | static int vb2_dma_contig_mmap(void *buf_priv, struct vm_area_struct *vma) | |
101 | { | |
102 | struct vb2_dc_buf *buf = buf_priv; | |
103 | ||
104 | if (!buf) { | |
105 | printk(KERN_ERR "No buffer to map\n"); | |
106 | return -EINVAL; | |
107 | } | |
108 | ||
109 | return vb2_mmap_pfn_range(vma, buf->paddr, buf->size, | |
110 | &vb2_common_vm_ops, &buf->handler); | |
111 | } | |
112 | ||
113 | static void *vb2_dma_contig_get_userptr(void *alloc_ctx, unsigned long vaddr, | |
114 | unsigned long size, int write) | |
115 | { | |
116 | struct vb2_dc_buf *buf; | |
117 | struct vm_area_struct *vma; | |
118 | dma_addr_t paddr = 0; | |
119 | int ret; | |
120 | ||
121 | buf = kzalloc(sizeof *buf, GFP_KERNEL); | |
122 | if (!buf) | |
123 | return ERR_PTR(-ENOMEM); | |
124 | ||
125 | ret = vb2_get_contig_userptr(vaddr, size, &vma, &paddr); | |
126 | if (ret) { | |
127 | printk(KERN_ERR "Failed acquiring VMA for vaddr 0x%08lx\n", | |
128 | vaddr); | |
129 | kfree(buf); | |
130 | return ERR_PTR(ret); | |
131 | } | |
132 | ||
133 | buf->size = size; | |
134 | buf->paddr = paddr; | |
135 | buf->vma = vma; | |
136 | ||
137 | return buf; | |
138 | } | |
139 | ||
140 | static void vb2_dma_contig_put_userptr(void *mem_priv) | |
141 | { | |
142 | struct vb2_dc_buf *buf = mem_priv; | |
143 | ||
144 | if (!buf) | |
145 | return; | |
146 | ||
147 | vb2_put_vma(buf->vma); | |
148 | kfree(buf); | |
149 | } | |
150 | ||
151 | const struct vb2_mem_ops vb2_dma_contig_memops = { | |
152 | .alloc = vb2_dma_contig_alloc, | |
153 | .put = vb2_dma_contig_put, | |
154 | .cookie = vb2_dma_contig_cookie, | |
155 | .vaddr = vb2_dma_contig_vaddr, | |
156 | .mmap = vb2_dma_contig_mmap, | |
157 | .get_userptr = vb2_dma_contig_get_userptr, | |
158 | .put_userptr = vb2_dma_contig_put_userptr, | |
159 | .num_users = vb2_dma_contig_num_users, | |
160 | }; | |
161 | EXPORT_SYMBOL_GPL(vb2_dma_contig_memops); | |
162 | ||
163 | void *vb2_dma_contig_init_ctx(struct device *dev) | |
164 | { | |
165 | struct vb2_dc_conf *conf; | |
166 | ||
167 | conf = kzalloc(sizeof *conf, GFP_KERNEL); | |
168 | if (!conf) | |
169 | return ERR_PTR(-ENOMEM); | |
170 | ||
171 | conf->dev = dev; | |
172 | ||
173 | return conf; | |
174 | } | |
175 | EXPORT_SYMBOL_GPL(vb2_dma_contig_init_ctx); | |
176 | ||
177 | void vb2_dma_contig_cleanup_ctx(void *alloc_ctx) | |
178 | { | |
179 | kfree(alloc_ctx); | |
180 | } | |
181 | EXPORT_SYMBOL_GPL(vb2_dma_contig_cleanup_ctx); | |
182 | ||
183 | MODULE_DESCRIPTION("DMA-contig memory handling routines for videobuf2"); | |
95072084 | 184 | MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>"); |
1a758d4e | 185 | MODULE_LICENSE("GPL"); |