V4L/DVB: v4l videobuf: move video_copy_to_user and copy_stream to core
[deliverable/linux.git] / drivers / media / video / videobuf-vmalloc.c
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1/*
2 * helper functions for vmalloc video4linux capture buffers
3 *
5d6aaf50 4 * The functions expect the hardware being able to scatter gather
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5 * (i.e. the buffers are not linear in physical memory, but fragmented
6 * into PAGE_SIZE chunks). They also assume the driver does not need
7 * to touch the video data.
8 *
9 * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2
14 */
15
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/moduleparam.h>
19#include <linux/slab.h>
20#include <linux/interrupt.h>
21
22#include <linux/pci.h>
23#include <linux/vmalloc.h>
24#include <linux/pagemap.h>
25#include <asm/page.h>
26#include <asm/pgtable.h>
27
28#include <media/videobuf-vmalloc.h>
29
30#define MAGIC_DMABUF 0x17760309
31#define MAGIC_VMAL_MEM 0x18221223
32
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33#define MAGIC_CHECK(is, should) \
34 if (unlikely((is) != (should))) { \
35 printk(KERN_ERR "magic mismatch: %x (expected %x)\n", \
36 is, should); \
37 BUG(); \
38 }
87b9ad07 39
ff699e6b 40static int debug;
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41module_param(debug, int, 0644);
42
43MODULE_DESCRIPTION("helper module to manage video4linux vmalloc buffers");
44MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
45MODULE_LICENSE("GPL");
46
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47#define dprintk(level, fmt, arg...) \
48 if (debug >= level) \
49 printk(KERN_DEBUG "vbuf-vmalloc: " fmt , ## arg)
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50
51
52/***************************************************************************/
53
7a02264c 54static void videobuf_vm_open(struct vm_area_struct *vma)
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55{
56 struct videobuf_mapping *map = vma->vm_private_data;
57
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58 dprintk(2, "vm_open %p [count=%u,vma=%08lx-%08lx]\n", map,
59 map->count, vma->vm_start, vma->vm_end);
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60
61 map->count++;
62}
63
aaea56af 64static void videobuf_vm_close(struct vm_area_struct *vma)
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65{
66 struct videobuf_mapping *map = vma->vm_private_data;
67 struct videobuf_queue *q = map->q;
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68 int i;
69
7a02264c 70 dprintk(2, "vm_close %p [count=%u,vma=%08lx-%08lx]\n", map,
aaea56af 71 map->count, vma->vm_start, vma->vm_end);
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72
73 map->count--;
74 if (0 == map->count) {
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75 struct videobuf_vmalloc_memory *mem;
76
77 dprintk(1, "munmap %p q=%p\n", map, q);
64f9477f 78 mutex_lock(&q->vb_lock);
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79
80 /* We need first to cancel streams, before unmapping */
81 if (q->streaming)
82 videobuf_queue_cancel(q);
83
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84 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
85 if (NULL == q->bufs[i])
86 continue;
87b9ad07 87
851c0c96 88 if (q->bufs[i]->map != map)
87b9ad07 89 continue;
123f8ef6 90
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91 mem = q->bufs[i]->priv;
92 if (mem) {
93 /* This callback is called only if kernel has
94 allocated memory and this memory is mmapped.
95 In this case, memory should be freed,
96 in order to do memory unmap.
97 */
aa9479ed 98
aaea56af 99 MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);
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100
101 /* vfree is not atomic - can't be
102 called with IRQ's disabled
103 */
104 dprintk(1, "%s: buf[%d] freeing (%p)\n",
105 __func__, i, mem->vmalloc);
106
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107 vfree(mem->vmalloc);
108 mem->vmalloc = NULL;
109 }
110
851c0c96 111 q->bufs[i]->map = NULL;
87b9ad07 112 q->bufs[i]->baddr = 0;
87b9ad07 113 }
aa9479ed 114
87b9ad07 115 kfree(map);
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116
117 mutex_unlock(&q->vb_lock);
87b9ad07 118 }
aa9479ed 119
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120 return;
121}
122
7a02264c 123static const struct vm_operations_struct videobuf_vm_ops = {
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124 .open = videobuf_vm_open,
125 .close = videobuf_vm_close,
126};
127
128/* ---------------------------------------------------------------------
129 * vmalloc handlers for the generic methods
130 */
131
132/* Allocated area consists on 3 parts:
133 struct video_buffer
134 struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
0705135e 135 struct videobuf_dma_sg_memory
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136 */
137
a4cf4cac 138static struct videobuf_buffer *__videobuf_alloc(size_t size)
87b9ad07 139{
384b835a 140 struct videobuf_vmalloc_memory *mem;
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141 struct videobuf_buffer *vb;
142
7a02264c 143 vb = kzalloc(size + sizeof(*mem), GFP_KERNEL);
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144 if (!vb)
145 return vb;
87b9ad07 146
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147 mem = vb->priv = ((char *)vb) + size;
148 mem->magic = MAGIC_VMAL_MEM;
87b9ad07 149
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150 dprintk(1, "%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
151 __func__, vb, (long)sizeof(*vb), (long)size - sizeof(*vb),
152 mem, (long)sizeof(*mem));
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153
154 return vb;
155}
156
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157static int __videobuf_iolock(struct videobuf_queue *q,
158 struct videobuf_buffer *vb,
159 struct v4l2_framebuffer *fbuf)
87b9ad07 160{
968ced78 161 struct videobuf_vmalloc_memory *mem = vb->priv;
aa9479ed 162 int pages;
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163
164 BUG_ON(!mem);
165
968ced78 166 MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);
87b9ad07 167
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168 switch (vb->memory) {
169 case V4L2_MEMORY_MMAP:
170 dprintk(1, "%s memory method MMAP\n", __func__);
87b9ad07 171
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172 /* All handling should be done by __videobuf_mmap_mapper() */
173 if (!mem->vmalloc) {
174 printk(KERN_ERR "memory is not alloced/mmapped.\n");
175 return -EINVAL;
176 }
177 break;
178 case V4L2_MEMORY_USERPTR:
aa9479ed 179 pages = PAGE_ALIGN(vb->size);
87b9ad07 180
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181 dprintk(1, "%s memory method USERPTR\n", __func__);
182
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183 if (vb->baddr) {
184 printk(KERN_ERR "USERPTR is currently not supported\n");
185 return -EINVAL;
186 }
87b9ad07 187
968ced78 188 /* The only USERPTR currently supported is the one needed for
7a02264c 189 * read() method.
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190 */
191
192 mem->vmalloc = vmalloc_user(pages);
193 if (!mem->vmalloc) {
194 printk(KERN_ERR "vmalloc (%d pages) failed\n", pages);
195 return -ENOMEM;
87b9ad07 196 }
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197 dprintk(1, "vmalloc is at addr %p (%d pages)\n",
198 mem->vmalloc, pages);
199
200#if 0
201 int rc;
202 /* Kernel userptr is used also by read() method. In this case,
203 there's no need to remap, since data will be copied to user
204 */
205 if (!vb->baddr)
206 return 0;
207
208 /* FIXME: to properly support USERPTR, remap should occur.
de1e575d 209 The code below won't work, since mem->vma = NULL
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210 */
211 /* Try to remap memory */
212 rc = remap_vmalloc_range(mem->vma, (void *)vb->baddr, 0);
213 if (rc < 0) {
7a02264c 214 printk(KERN_ERR "mmap: remap failed with error %d", rc);
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215 return -ENOMEM;
216 }
217#endif
218
219 break;
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220 case V4L2_MEMORY_OVERLAY:
221 default:
222 dprintk(1, "%s memory method OVERLAY/unknown\n", __func__);
223
224 /* Currently, doesn't support V4L2_MEMORY_OVERLAY */
225 printk(KERN_ERR "Memory method currently unsupported.\n");
226 return -EINVAL;
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227 }
228
229 return 0;
230}
231
232static int __videobuf_sync(struct videobuf_queue *q,
233 struct videobuf_buffer *buf)
234{
235 return 0;
236}
237
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238static int __videobuf_mmap_mapper(struct videobuf_queue *q,
239 struct vm_area_struct *vma)
240{
384b835a 241 struct videobuf_vmalloc_memory *mem;
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242 struct videobuf_mapping *map;
243 unsigned int first;
968ced78 244 int retval, pages;
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245 unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
246
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247 dprintk(1, "%s\n", __func__);
248 if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED))
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249 return -EINVAL;
250
251 /* look for first buffer to map */
252 for (first = 0; first < VIDEO_MAX_FRAME; first++) {
253 if (NULL == q->bufs[first])
254 continue;
255
256 if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
257 continue;
258 if (q->bufs[first]->boff == offset)
259 break;
260 }
261 if (VIDEO_MAX_FRAME == first) {
7a02264c 262 dprintk(1, "mmap app bug: offset invalid [offset=0x%lx]\n",
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263 (vma->vm_pgoff << PAGE_SHIFT));
264 return -EINVAL;
265 }
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266
267 /* create mapping + update buffer list */
968ced78 268 map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL);
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269 if (NULL == map)
270 return -ENOMEM;
271
968ced78 272 q->bufs[first]->map = map;
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273 map->start = vma->vm_start;
274 map->end = vma->vm_end;
275 map->q = q;
276
277 q->bufs[first]->baddr = vma->vm_start;
278
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279 mem = q->bufs[first]->priv;
280 BUG_ON(!mem);
281 MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);
87b9ad07 282
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283 pages = PAGE_ALIGN(vma->vm_end - vma->vm_start);
284 mem->vmalloc = vmalloc_user(pages);
285 if (!mem->vmalloc) {
286 printk(KERN_ERR "vmalloc (%d pages) failed\n", pages);
287 goto error;
288 }
7a02264c 289 dprintk(1, "vmalloc is at addr %p (%d pages)\n", mem->vmalloc, pages);
851c0c96 290
87b9ad07 291 /* Try to remap memory */
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292 retval = remap_vmalloc_range(vma, mem->vmalloc, 0);
293 if (retval < 0) {
294 printk(KERN_ERR "mmap: remap failed with error %d. ", retval);
295 vfree(mem->vmalloc);
296 goto error;
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297 }
298
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299 vma->vm_ops = &videobuf_vm_ops;
300 vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
301 vma->vm_private_data = map;
302
7a02264c 303 dprintk(1, "mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n",
968ced78 304 map, q, vma->vm_start, vma->vm_end,
87b9ad07 305 (long int) q->bufs[first]->bsize,
968ced78 306 vma->vm_pgoff, first);
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307
308 videobuf_vm_open(vma);
309
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310 return 0;
311
312error:
313 mem = NULL;
314 kfree(map);
315 return -ENOMEM;
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316}
317
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318static struct videobuf_qtype_ops qops = {
319 .magic = MAGIC_QTYPE_OPS,
320
321 .alloc = __videobuf_alloc,
322 .iolock = __videobuf_iolock,
323 .sync = __videobuf_sync,
87b9ad07 324 .mmap_mapper = __videobuf_mmap_mapper,
037c75eb 325 .vaddr = videobuf_to_vmalloc,
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326};
327
7a02264c 328void videobuf_queue_vmalloc_init(struct videobuf_queue *q,
38a54f35 329 const struct videobuf_queue_ops *ops,
f8b0bca1 330 struct device *dev,
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331 spinlock_t *irqlock,
332 enum v4l2_buf_type type,
333 enum v4l2_field field,
334 unsigned int msize,
335 void *priv)
336{
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337 videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
338 priv, &qops);
87b9ad07 339}
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340EXPORT_SYMBOL_GPL(videobuf_queue_vmalloc_init);
341
7a02264c 342void *videobuf_to_vmalloc(struct videobuf_buffer *buf)
87b9ad07 343{
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344 struct videobuf_vmalloc_memory *mem = buf->priv;
345 BUG_ON(!mem);
346 MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);
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347
348 return mem->vmalloc;
349}
350EXPORT_SYMBOL_GPL(videobuf_to_vmalloc);
351
7a02264c 352void videobuf_vmalloc_free(struct videobuf_buffer *buf)
87b9ad07 353{
968ced78 354 struct videobuf_vmalloc_memory *mem = buf->priv;
87b9ad07 355
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356 /* mmapped memory can't be freed here, otherwise mmapped region
357 would be released, while still needed. In this case, the memory
358 release should happen inside videobuf_vm_close().
359 So, it should free memory only if the memory were allocated for
360 read() operation.
361 */
5993a663 362 if ((buf->memory != V4L2_MEMORY_USERPTR) || buf->baddr)
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363 return;
364
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365 if (!mem)
366 return;
367
368 MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);
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369
370 vfree(mem->vmalloc);
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371 mem->vmalloc = NULL;
372
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373 return;
374}
375EXPORT_SYMBOL_GPL(videobuf_vmalloc_free);
376
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