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17#include <linux/init.h>
18#include <linux/module.h>
19#include <linux/mm.h>
20#include <linux/pagemap.h>
21#include <linux/dma-mapping.h>
22#include <linux/sched.h>
23#include <media/videobuf-dma-contig.h>
24
25struct videobuf_dma_contig_memory {
26 u32 magic;
27 void *vaddr;
28 dma_addr_t dma_handle;
29 unsigned long size;
30 int is_userptr;
31};
32
33#define MAGIC_DC_MEM 0x0733ac61
34#define MAGIC_CHECK(is, should) \
35 if (unlikely((is) != (should))) { \
36 pr_err("magic mismatch: %x expected %x\n", (is), (should)); \
37 BUG(); \
38 }
39
40static void
41videobuf_vm_open(struct vm_area_struct *vma)
42{
43 struct videobuf_mapping *map = vma->vm_private_data;
44
45 dev_dbg(map->q->dev, "vm_open %p [count=%u,vma=%08lx-%08lx]\n",
46 map, map->count, vma->vm_start, vma->vm_end);
47
48 map->count++;
49}
50
51static void videobuf_vm_close(struct vm_area_struct *vma)
52{
53 struct videobuf_mapping *map = vma->vm_private_data;
54 struct videobuf_queue *q = map->q;
55 int i;
56
57 dev_dbg(map->q->dev, "vm_close %p [count=%u,vma=%08lx-%08lx]\n",
58 map, map->count, vma->vm_start, vma->vm_end);
59
60 map->count--;
61 if (0 == map->count) {
62 struct videobuf_dma_contig_memory *mem;
63
64 dev_dbg(map->q->dev, "munmap %p q=%p\n", map, q);
65 mutex_lock(&q->vb_lock);
66
67
68 if (q->streaming)
69 videobuf_queue_cancel(q);
70
71 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
72 if (NULL == q->bufs[i])
73 continue;
74
75 if (q->bufs[i]->map != map)
76 continue;
77
78 mem = q->bufs[i]->priv;
79 if (mem) {
80
81
82
83
84
85
86 MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
87
88
89
90
91 dev_dbg(map->q->dev, "buf[%d] freeing %p\n",
92 i, mem->vaddr);
93
94 dma_free_coherent(q->dev, mem->size,
95 mem->vaddr, mem->dma_handle);
96 mem->vaddr = NULL;
97 }
98
99 q->bufs[i]->map = NULL;
100 q->bufs[i]->baddr = 0;
101 }
102
103 kfree(map);
104
105 mutex_unlock(&q->vb_lock);
106 }
107}
108
109static const struct vm_operations_struct videobuf_vm_ops = {
110 .open = videobuf_vm_open,
111 .close = videobuf_vm_close,
112};
113
114
115
116
117
118
119
120static void videobuf_dma_contig_user_put(struct videobuf_dma_contig_memory *mem)
121{
122 mem->is_userptr = 0;
123 mem->dma_handle = 0;
124 mem->size = 0;
125}
126
127
128
129
130
131
132
133
134
135
136
137static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem,
138 struct videobuf_buffer *vb)
139{
140 struct mm_struct *mm = current->mm;
141 struct vm_area_struct *vma;
142 unsigned long prev_pfn, this_pfn;
143 unsigned long pages_done, user_address;
144 int ret;
145
146 mem->size = PAGE_ALIGN(vb->size);
147 mem->is_userptr = 0;
148 ret = -EINVAL;
149
150 down_read(&mm->mmap_sem);
151
152 vma = find_vma(mm, vb->baddr);
153 if (!vma)
154 goto out_up;
155
156 if ((vb->baddr + mem->size) > vma->vm_end)
157 goto out_up;
158
159 pages_done = 0;
160 prev_pfn = 0;
161 user_address = vb->baddr;
162
163 while (pages_done < (mem->size >> PAGE_SHIFT)) {
164 ret = follow_pfn(vma, user_address, &this_pfn);
165 if (ret)
166 break;
167
168 if (pages_done == 0)
169 mem->dma_handle = this_pfn << PAGE_SHIFT;
170 else if (this_pfn != (prev_pfn + 1))
171 ret = -EFAULT;
172
173 if (ret)
174 break;
175
176 prev_pfn = this_pfn;
177 user_address += PAGE_SIZE;
178 pages_done++;
179 }
180
181 if (!ret)
182 mem->is_userptr = 1;
183
184 out_up:
185 up_read(¤t->mm->mmap_sem);
186
187 return ret;
188}
189
190static void *__videobuf_alloc(size_t size)
191{
192 struct videobuf_dma_contig_memory *mem;
193 struct videobuf_buffer *vb;
194
195 vb = kzalloc(size + sizeof(*mem), GFP_KERNEL);
196 if (vb) {
197 mem = vb->priv = ((char *)vb) + size;
198 mem->magic = MAGIC_DC_MEM;
199 }
200
201 return vb;
202}
203
204static void *__videobuf_to_vmalloc(struct videobuf_buffer *buf)
205{
206 struct videobuf_dma_contig_memory *mem = buf->priv;
207
208 BUG_ON(!mem);
209 MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
210
211 return mem->vaddr;
212}
213
214static int __videobuf_iolock(struct videobuf_queue *q,
215 struct videobuf_buffer *vb,
216 struct v4l2_framebuffer *fbuf)
217{
218 struct videobuf_dma_contig_memory *mem = vb->priv;
219
220 BUG_ON(!mem);
221 MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
222
223 switch (vb->memory) {
224 case V4L2_MEMORY_MMAP:
225 dev_dbg(q->dev, "%s memory method MMAP\n", __func__);
226
227
228 if (!mem->vaddr) {
229 dev_err(q->dev, "memory is not alloced/mmapped.\n");
230 return -EINVAL;
231 }
232 break;
233 case V4L2_MEMORY_USERPTR:
234 dev_dbg(q->dev, "%s memory method USERPTR\n", __func__);
235
236
237 if (vb->baddr)
238 return videobuf_dma_contig_user_get(mem, vb);
239
240
241 mem->size = PAGE_ALIGN(vb->size);
242 mem->vaddr = dma_alloc_coherent(q->dev, mem->size,
243 &mem->dma_handle, GFP_KERNEL);
244 if (!mem->vaddr) {
245 dev_err(q->dev, "dma_alloc_coherent %ld failed\n",
246 mem->size);
247 return -ENOMEM;
248 }
249
250 dev_dbg(q->dev, "dma_alloc_coherent data is at %p (%ld)\n",
251 mem->vaddr, mem->size);
252 break;
253 case V4L2_MEMORY_OVERLAY:
254 default:
255 dev_dbg(q->dev, "%s memory method OVERLAY/unknown\n",
256 __func__);
257 return -EINVAL;
258 }
259
260 return 0;
261}
262
263static int __videobuf_mmap_free(struct videobuf_queue *q)
264{
265 unsigned int i;
266
267 dev_dbg(q->dev, "%s\n", __func__);
268 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
269 if (q->bufs[i] && q->bufs[i]->map)
270 return -EBUSY;
271 }
272
273 return 0;
274}
275
276static int __videobuf_mmap_mapper(struct videobuf_queue *q,
277 struct vm_area_struct *vma)
278{
279 struct videobuf_dma_contig_memory *mem;
280 struct videobuf_mapping *map;
281 unsigned int first;
282 int retval;
283 unsigned long size, offset = vma->vm_pgoff << PAGE_SHIFT;
284
285 dev_dbg(q->dev, "%s\n", __func__);
286 if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED))
287 return -EINVAL;
288
289
290 for (first = 0; first < VIDEO_MAX_FRAME; first++) {
291 if (!q->bufs[first])
292 continue;
293
294 if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
295 continue;
296 if (q->bufs[first]->boff == offset)
297 break;
298 }
299 if (VIDEO_MAX_FRAME == first) {
300 dev_dbg(q->dev, "invalid user space offset [offset=0x%lx]\n",
301 offset);
302 return -EINVAL;
303 }
304
305
306 map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL);
307 if (!map)
308 return -ENOMEM;
309
310 q->bufs[first]->map = map;
311 map->start = vma->vm_start;
312 map->end = vma->vm_end;
313 map->q = q;
314
315 q->bufs[first]->baddr = vma->vm_start;
316
317 mem = q->bufs[first]->priv;
318 BUG_ON(!mem);
319 MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
320
321 mem->size = PAGE_ALIGN(q->bufs[first]->bsize);
322 mem->vaddr = dma_alloc_coherent(q->dev, mem->size,
323 &mem->dma_handle, GFP_KERNEL);
324 if (!mem->vaddr) {
325 dev_err(q->dev, "dma_alloc_coherent size %ld failed\n",
326 mem->size);
327 goto error;
328 }
329 dev_dbg(q->dev, "dma_alloc_coherent data is at addr %p (size %ld)\n",
330 mem->vaddr, mem->size);
331
332
333
334 size = vma->vm_end - vma->vm_start;
335 size = (size < mem->size) ? size : mem->size;
336
337 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
338 retval = remap_pfn_range(vma, vma->vm_start,
339 mem->dma_handle >> PAGE_SHIFT,
340 size, vma->vm_page_prot);
341 if (retval) {
342 dev_err(q->dev, "mmap: remap failed with error %d. ", retval);
343 dma_free_coherent(q->dev, mem->size,
344 mem->vaddr, mem->dma_handle);
345 goto error;
346 }
347
348 vma->vm_ops = &videobuf_vm_ops;
349 vma->vm_flags |= VM_DONTEXPAND;
350 vma->vm_private_data = map;
351
352 dev_dbg(q->dev, "mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n",
353 map, q, vma->vm_start, vma->vm_end,
354 (long int) q->bufs[first]->bsize,
355 vma->vm_pgoff, first);
356
357 videobuf_vm_open(vma);
358
359 return 0;
360
361error:
362 kfree(map);
363 return -ENOMEM;
364}
365
366static int __videobuf_copy_to_user(struct videobuf_queue *q,
367 char __user *data, size_t count,
368 int nonblocking)
369{
370 struct videobuf_dma_contig_memory *mem = q->read_buf->priv;
371 void *vaddr;
372
373 BUG_ON(!mem);
374 MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
375 BUG_ON(!mem->vaddr);
376
377
378 if (count > q->read_buf->size - q->read_off)
379 count = q->read_buf->size - q->read_off;
380
381 vaddr = mem->vaddr;
382
383 if (copy_to_user(data, vaddr + q->read_off, count))
384 return -EFAULT;
385
386 return count;
387}
388
389static int __videobuf_copy_stream(struct videobuf_queue *q,
390 char __user *data, size_t count, size_t pos,
391 int vbihack, int nonblocking)
392{
393 unsigned int *fc;
394 struct videobuf_dma_contig_memory *mem = q->read_buf->priv;
395
396 BUG_ON(!mem);
397 MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
398
399 if (vbihack) {
400
401
402
403
404 fc = (unsigned int *)mem->vaddr;
405 fc += (q->read_buf->size >> 2) - 1;
406 *fc = q->read_buf->field_count >> 1;
407 dev_dbg(q->dev, "vbihack: %d\n", *fc);
408 }
409
410
411 count = __videobuf_copy_to_user(q, data, count, nonblocking);
412
413 if ((count == -EFAULT) && (pos == 0))
414 return -EFAULT;
415
416 return count;
417}
418
419static struct videobuf_qtype_ops qops = {
420 .magic = MAGIC_QTYPE_OPS,
421
422 .alloc = __videobuf_alloc,
423 .iolock = __videobuf_iolock,
424 .mmap_free = __videobuf_mmap_free,
425 .mmap_mapper = __videobuf_mmap_mapper,
426 .video_copy_to_user = __videobuf_copy_to_user,
427 .copy_stream = __videobuf_copy_stream,
428 .vmalloc = __videobuf_to_vmalloc,
429};
430
431void videobuf_queue_dma_contig_init(struct videobuf_queue *q,
432 struct videobuf_queue_ops *ops,
433 struct device *dev,
434 spinlock_t *irqlock,
435 enum v4l2_buf_type type,
436 enum v4l2_field field,
437 unsigned int msize,
438 void *priv)
439{
440 videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
441 priv, &qops);
442}
443EXPORT_SYMBOL_GPL(videobuf_queue_dma_contig_init);
444
445dma_addr_t videobuf_to_dma_contig(struct videobuf_buffer *buf)
446{
447 struct videobuf_dma_contig_memory *mem = buf->priv;
448
449 BUG_ON(!mem);
450 MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
451
452 return mem->dma_handle;
453}
454EXPORT_SYMBOL_GPL(videobuf_to_dma_contig);
455
456void videobuf_dma_contig_free(struct videobuf_queue *q,
457 struct videobuf_buffer *buf)
458{
459 struct videobuf_dma_contig_memory *mem = buf->priv;
460
461
462
463
464
465
466
467 if (buf->memory != V4L2_MEMORY_USERPTR)
468 return;
469
470 if (!mem)
471 return;
472
473 MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
474
475
476 if (buf->baddr) {
477 videobuf_dma_contig_user_put(mem);
478 return;
479 }
480
481
482 dma_free_coherent(q->dev, mem->size, mem->vaddr, mem->dma_handle);
483 mem->vaddr = NULL;
484}
485EXPORT_SYMBOL_GPL(videobuf_dma_contig_free);
486
487MODULE_DESCRIPTION("helper module to manage video4linux dma contig buffers");
488MODULE_AUTHOR("Magnus Damm");
489MODULE_LICENSE("GPL");
490