Pawel Osciak | 1a758d4 | 2010-10-11 10:59:36 -0300 | [diff] [blame] | 1 | /* |
| 2 | * videobuf2-dma-contig.c - DMA contig memory allocator 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> |
Pawel Osciak | 1a758d4 | 2010-10-11 10:59:36 -0300 | [diff] [blame] | 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", |
| 49 | buf->size); |
| 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 | |
Pawel Osciak | 472af2b | 2011-03-14 10:38:24 -0300 | [diff] [blame] | 81 | return &buf->paddr; |
Pawel Osciak | 1a758d4 | 2010-10-11 10:59:36 -0300 | [diff] [blame] | 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"); |
Pawel Osciak | 9507208 | 2011-03-13 15:23:32 -0300 | [diff] [blame] | 184 | MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>"); |
Pawel Osciak | 1a758d4 | 2010-10-11 10:59:36 -0300 | [diff] [blame] | 185 | MODULE_LICENSE("GPL"); |