Marek Szyprowski | 004cc37 | 2010-12-09 10:20:47 -0300 | [diff] [blame] | 1 | /* |
| 2 | * videobuf2-memops.c - generic memory handling routines for videobuf2 |
| 3 | * |
| 4 | * Copyright (C) 2010 Samsung Electronics |
| 5 | * |
Pawel Osciak | 9507208 | 2011-03-13 15:23:32 -0300 | [diff] [blame] | 6 | * Author: Pawel Osciak <pawel@osciak.com> |
Marek Szyprowski | 004cc37 | 2010-12-09 10:20:47 -0300 | [diff] [blame] | 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> |
Marek Szyprowski | 004cc37 | 2010-12-09 10:20:47 -0300 | [diff] [blame] | 21 | |
Junghak Sung | c139990 | 2015-09-22 10:30:29 -0300 | [diff] [blame] | 22 | #include <media/videobuf2-v4l2.h> |
Marek Szyprowski | 004cc37 | 2010-12-09 10:20:47 -0300 | [diff] [blame] | 23 | #include <media/videobuf2-memops.h> |
| 24 | |
| 25 | /** |
Jan Kara | 21fb0cb | 2015-07-13 11:55:46 -0300 | [diff] [blame] | 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; |
| 45 | |
| 46 | first = start >> PAGE_SHIFT; |
| 47 | last = (start + length - 1) >> PAGE_SHIFT; |
| 48 | nr = last - first + 1; |
| 49 | vec = frame_vector_create(nr); |
| 50 | if (!vec) |
| 51 | return ERR_PTR(-ENOMEM); |
| 52 | ret = get_vaddr_frames(start, nr, write, 1, vec); |
| 53 | if (ret < 0) |
| 54 | goto out_destroy; |
| 55 | /* We accept only complete set of PFNs */ |
| 56 | if (ret != nr) { |
| 57 | ret = -EFAULT; |
| 58 | goto out_release; |
| 59 | } |
| 60 | return vec; |
| 61 | out_release: |
| 62 | put_vaddr_frames(vec); |
| 63 | out_destroy: |
| 64 | frame_vector_destroy(vec); |
| 65 | return ERR_PTR(ret); |
| 66 | } |
| 67 | EXPORT_SYMBOL(vb2_create_framevec); |
| 68 | |
| 69 | /** |
| 70 | * vb2_destroy_framevec() - release vector of mapped pfns |
| 71 | * @vec: vector of pfns / pages to release |
| 72 | * |
| 73 | * This releases references to all pages in the vector @vec (if corresponding |
| 74 | * pfns are backed by pages) and frees the passed vector. |
| 75 | */ |
| 76 | void vb2_destroy_framevec(struct frame_vector *vec) |
| 77 | { |
| 78 | put_vaddr_frames(vec); |
| 79 | frame_vector_destroy(vec); |
| 80 | } |
| 81 | EXPORT_SYMBOL(vb2_destroy_framevec); |
| 82 | |
| 83 | /** |
Marek Szyprowski | 004cc37 | 2010-12-09 10:20:47 -0300 | [diff] [blame] | 84 | * vb2_common_vm_open() - increase refcount of the vma |
| 85 | * @vma: virtual memory region for the mapping |
| 86 | * |
| 87 | * This function adds another user to the provided vma. It expects |
| 88 | * struct vb2_vmarea_handler pointer in vma->vm_private_data. |
| 89 | */ |
| 90 | static void vb2_common_vm_open(struct vm_area_struct *vma) |
| 91 | { |
| 92 | struct vb2_vmarea_handler *h = vma->vm_private_data; |
| 93 | |
Uwe Kleine-König | 7f116b3 | 2011-06-01 17:19:22 -0300 | [diff] [blame] | 94 | pr_debug("%s: %p, refcount: %d, vma: %08lx-%08lx\n", |
Marek Szyprowski | 004cc37 | 2010-12-09 10:20:47 -0300 | [diff] [blame] | 95 | __func__, h, atomic_read(h->refcount), vma->vm_start, |
| 96 | vma->vm_end); |
| 97 | |
| 98 | atomic_inc(h->refcount); |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * vb2_common_vm_close() - decrease refcount of the vma |
| 103 | * @vma: virtual memory region for the mapping |
| 104 | * |
| 105 | * This function releases the user from the provided vma. It expects |
| 106 | * struct vb2_vmarea_handler pointer in vma->vm_private_data. |
| 107 | */ |
| 108 | static void vb2_common_vm_close(struct vm_area_struct *vma) |
| 109 | { |
| 110 | struct vb2_vmarea_handler *h = vma->vm_private_data; |
| 111 | |
Uwe Kleine-König | 7f116b3 | 2011-06-01 17:19:22 -0300 | [diff] [blame] | 112 | pr_debug("%s: %p, refcount: %d, vma: %08lx-%08lx\n", |
Marek Szyprowski | 004cc37 | 2010-12-09 10:20:47 -0300 | [diff] [blame] | 113 | __func__, h, atomic_read(h->refcount), vma->vm_start, |
| 114 | vma->vm_end); |
| 115 | |
| 116 | h->put(h->arg); |
| 117 | } |
| 118 | |
| 119 | /** |
| 120 | * vb2_common_vm_ops - common vm_ops used for tracking refcount of mmaped |
| 121 | * video buffers |
| 122 | */ |
| 123 | const struct vm_operations_struct vb2_common_vm_ops = { |
| 124 | .open = vb2_common_vm_open, |
| 125 | .close = vb2_common_vm_close, |
| 126 | }; |
| 127 | EXPORT_SYMBOL_GPL(vb2_common_vm_ops); |
| 128 | |
| 129 | MODULE_DESCRIPTION("common memory handling routines for videobuf2"); |
Pawel Osciak | 9507208 | 2011-03-13 15:23:32 -0300 | [diff] [blame] | 130 | MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>"); |
Marek Szyprowski | 004cc37 | 2010-12-09 10:20:47 -0300 | [diff] [blame] | 131 | MODULE_LICENSE("GPL"); |