Commit | Line | Data |
---|---|---|
004cc378 MS |
1 | /* |
2 | * videobuf2-memops.c - generic memory handling routines for videobuf2 | |
3 | * | |
4 | * Copyright (C) 2010 Samsung Electronics | |
5 | * | |
95072084 | 6 | * Author: Pawel Osciak <pawel@osciak.com> |
004cc378 MS |
7 | * Marek Szyprowski <m.szyprowski@samsung.com> |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation. | |
12 | */ | |
13 | ||
14 | #include <linux/slab.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/dma-mapping.h> | |
17 | #include <linux/vmalloc.h> | |
18 | #include <linux/mm.h> | |
19 | #include <linux/sched.h> | |
20 | #include <linux/file.h> | |
004cc378 | 21 | |
c139990e | 22 | #include <media/videobuf2-v4l2.h> |
004cc378 MS |
23 | #include <media/videobuf2-memops.h> |
24 | ||
21fb0cb7 JK |
25 | /** |
26 | * vb2_create_framevec() - map virtual addresses to pfns | |
27 | * @start: Virtual user address where we start mapping | |
28 | * @length: Length of a range to map | |
29 | * @write: Should we map for writing into the area | |
30 | * | |
31 | * This function allocates and fills in a vector with pfns corresponding to | |
32 | * virtual address range passed in arguments. If pfns have corresponding pages, | |
33 | * page references are also grabbed to pin pages in memory. The function | |
34 | * returns pointer to the vector on success and error pointer in case of | |
35 | * failure. Returned vector needs to be freed via vb2_destroy_pfnvec(). | |
36 | */ | |
37 | struct frame_vector *vb2_create_framevec(unsigned long start, | |
38 | unsigned long length, | |
39 | bool write) | |
40 | { | |
41 | int ret; | |
42 | unsigned long first, last; | |
43 | unsigned long nr; | |
44 | struct frame_vector *vec; | |
7f23b350 LS |
45 | unsigned int flags = FOLL_FORCE; |
46 | ||
47 | if (write) | |
48 | flags |= FOLL_WRITE; | |
21fb0cb7 JK |
49 | |
50 | first = start >> PAGE_SHIFT; | |
51 | last = (start + length - 1) >> PAGE_SHIFT; | |
52 | nr = last - first + 1; | |
53 | vec = frame_vector_create(nr); | |
54 | if (!vec) | |
55 | return ERR_PTR(-ENOMEM); | |
7f23b350 | 56 | ret = get_vaddr_frames(start & PAGE_MASK, nr, flags, vec); |
21fb0cb7 JK |
57 | if (ret < 0) |
58 | goto out_destroy; | |
59 | /* We accept only complete set of PFNs */ | |
60 | if (ret != nr) { | |
61 | ret = -EFAULT; | |
62 | goto out_release; | |
63 | } | |
64 | return vec; | |
65 | out_release: | |
66 | put_vaddr_frames(vec); | |
67 | out_destroy: | |
68 | frame_vector_destroy(vec); | |
69 | return ERR_PTR(ret); | |
70 | } | |
71 | EXPORT_SYMBOL(vb2_create_framevec); | |
72 | ||
73 | /** | |
74 | * vb2_destroy_framevec() - release vector of mapped pfns | |
75 | * @vec: vector of pfns / pages to release | |
76 | * | |
77 | * This releases references to all pages in the vector @vec (if corresponding | |
78 | * pfns are backed by pages) and frees the passed vector. | |
79 | */ | |
80 | void vb2_destroy_framevec(struct frame_vector *vec) | |
81 | { | |
82 | put_vaddr_frames(vec); | |
83 | frame_vector_destroy(vec); | |
84 | } | |
85 | EXPORT_SYMBOL(vb2_destroy_framevec); | |
86 | ||
004cc378 MS |
87 | /** |
88 | * vb2_common_vm_open() - increase refcount of the vma | |
89 | * @vma: virtual memory region for the mapping | |
90 | * | |
91 | * This function adds another user to the provided vma. It expects | |
92 | * struct vb2_vmarea_handler pointer in vma->vm_private_data. | |
93 | */ | |
94 | static void vb2_common_vm_open(struct vm_area_struct *vma) | |
95 | { | |
96 | struct vb2_vmarea_handler *h = vma->vm_private_data; | |
97 | ||
7f116b3e | 98 | pr_debug("%s: %p, refcount: %d, vma: %08lx-%08lx\n", |
6c4bb65d | 99 | __func__, h, refcount_read(h->refcount), vma->vm_start, |
004cc378 MS |
100 | vma->vm_end); |
101 | ||
6c4bb65d | 102 | refcount_inc(h->refcount); |
004cc378 MS |
103 | } |
104 | ||
105 | /** | |
106 | * vb2_common_vm_close() - decrease refcount of the vma | |
107 | * @vma: virtual memory region for the mapping | |
108 | * | |
109 | * This function releases the user from the provided vma. It expects | |
110 | * struct vb2_vmarea_handler pointer in vma->vm_private_data. | |
111 | */ | |
112 | static void vb2_common_vm_close(struct vm_area_struct *vma) | |
113 | { | |
114 | struct vb2_vmarea_handler *h = vma->vm_private_data; | |
115 | ||
7f116b3e | 116 | pr_debug("%s: %p, refcount: %d, vma: %08lx-%08lx\n", |
6c4bb65d | 117 | __func__, h, refcount_read(h->refcount), vma->vm_start, |
004cc378 MS |
118 | vma->vm_end); |
119 | ||
120 | h->put(h->arg); | |
121 | } | |
122 | ||
d28b2cf9 | 123 | /* |
004cc378 MS |
124 | * vb2_common_vm_ops - common vm_ops used for tracking refcount of mmaped |
125 | * video buffers | |
126 | */ | |
127 | const struct vm_operations_struct vb2_common_vm_ops = { | |
128 | .open = vb2_common_vm_open, | |
129 | .close = vb2_common_vm_close, | |
130 | }; | |
131 | EXPORT_SYMBOL_GPL(vb2_common_vm_ops); | |
132 | ||
133 | MODULE_DESCRIPTION("common memory handling routines for videobuf2"); | |
95072084 | 134 | MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>"); |
004cc378 | 135 | MODULE_LICENSE("GPL"); |