Commit | Line | Data |
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2cc45cf2 MD |
1 | /* |
2 | * helper functions for physically contiguous capture buffers | |
3 | * | |
4 | * The functions support hardware lacking scatter gather support | |
5 | * (i.e. the buffers must be linear in physical memory) | |
6 | * | |
7 | * Copyright (c) 2008 Magnus Damm | |
8 | * | |
9 | * Based on videobuf-vmalloc.c, | |
10 | * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org> | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU General Public License as published by | |
14 | * the Free Software Foundation; either version 2 | |
15 | */ | |
16 | ||
17 | #include <linux/init.h> | |
18 | #include <linux/module.h> | |
f19ad390 | 19 | #include <linux/mm.h> |
720b17e7 | 20 | #include <linux/pagemap.h> |
2cc45cf2 MD |
21 | #include <linux/dma-mapping.h> |
22 | #include <media/videobuf-dma-contig.h> | |
23 | ||
24 | struct videobuf_dma_contig_memory { | |
25 | u32 magic; | |
26 | void *vaddr; | |
27 | dma_addr_t dma_handle; | |
28 | unsigned long size; | |
720b17e7 | 29 | int is_userptr; |
2cc45cf2 MD |
30 | }; |
31 | ||
32 | #define MAGIC_DC_MEM 0x0733ac61 | |
c60f2b5c GL |
33 | #define MAGIC_CHECK(is, should) \ |
34 | if (unlikely((is) != (should))) { \ | |
35 | pr_err("magic mismatch: %x expected %x\n", (is), (should)); \ | |
36 | BUG(); \ | |
2cc45cf2 MD |
37 | } |
38 | ||
39 | static void | |
40 | videobuf_vm_open(struct vm_area_struct *vma) | |
41 | { | |
42 | struct videobuf_mapping *map = vma->vm_private_data; | |
43 | ||
44 | dev_dbg(map->q->dev, "vm_open %p [count=%u,vma=%08lx-%08lx]\n", | |
45 | map, map->count, vma->vm_start, vma->vm_end); | |
46 | ||
47 | map->count++; | |
48 | } | |
49 | ||
50 | static void videobuf_vm_close(struct vm_area_struct *vma) | |
51 | { | |
52 | struct videobuf_mapping *map = vma->vm_private_data; | |
53 | struct videobuf_queue *q = map->q; | |
54 | int i; | |
55 | ||
56 | dev_dbg(map->q->dev, "vm_close %p [count=%u,vma=%08lx-%08lx]\n", | |
57 | map, map->count, vma->vm_start, vma->vm_end); | |
58 | ||
59 | map->count--; | |
60 | if (0 == map->count) { | |
61 | struct videobuf_dma_contig_memory *mem; | |
62 | ||
63 | dev_dbg(map->q->dev, "munmap %p q=%p\n", map, q); | |
64 | mutex_lock(&q->vb_lock); | |
65 | ||
66 | /* We need first to cancel streams, before unmapping */ | |
67 | if (q->streaming) | |
68 | videobuf_queue_cancel(q); | |
69 | ||
70 | for (i = 0; i < VIDEO_MAX_FRAME; i++) { | |
71 | if (NULL == q->bufs[i]) | |
72 | continue; | |
73 | ||
74 | if (q->bufs[i]->map != map) | |
75 | continue; | |
76 | ||
77 | mem = q->bufs[i]->priv; | |
78 | if (mem) { | |
79 | /* This callback is called only if kernel has | |
80 | allocated memory and this memory is mmapped. | |
81 | In this case, memory should be freed, | |
82 | in order to do memory unmap. | |
83 | */ | |
84 | ||
85 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
86 | ||
87 | /* vfree is not atomic - can't be | |
88 | called with IRQ's disabled | |
89 | */ | |
90 | dev_dbg(map->q->dev, "buf[%d] freeing %p\n", | |
91 | i, mem->vaddr); | |
92 | ||
93 | dma_free_coherent(q->dev, mem->size, | |
94 | mem->vaddr, mem->dma_handle); | |
95 | mem->vaddr = NULL; | |
96 | } | |
97 | ||
98 | q->bufs[i]->map = NULL; | |
99 | q->bufs[i]->baddr = 0; | |
100 | } | |
101 | ||
102 | kfree(map); | |
103 | ||
104 | mutex_unlock(&q->vb_lock); | |
105 | } | |
106 | } | |
107 | ||
f0f37e2f | 108 | static const struct vm_operations_struct videobuf_vm_ops = { |
2cc45cf2 MD |
109 | .open = videobuf_vm_open, |
110 | .close = videobuf_vm_close, | |
111 | }; | |
112 | ||
720b17e7 MD |
113 | /** |
114 | * videobuf_dma_contig_user_put() - reset pointer to user space buffer | |
115 | * @mem: per-buffer private videobuf-dma-contig data | |
116 | * | |
117 | * This function resets the user space pointer | |
118 | */ | |
119 | static void videobuf_dma_contig_user_put(struct videobuf_dma_contig_memory *mem) | |
120 | { | |
121 | mem->is_userptr = 0; | |
122 | mem->dma_handle = 0; | |
123 | mem->size = 0; | |
124 | } | |
125 | ||
126 | /** | |
127 | * videobuf_dma_contig_user_get() - setup user space memory pointer | |
128 | * @mem: per-buffer private videobuf-dma-contig data | |
129 | * @vb: video buffer to map | |
130 | * | |
131 | * This function validates and sets up a pointer to user space memory. | |
132 | * Only physically contiguous pfn-mapped memory is accepted. | |
133 | * | |
134 | * Returns 0 if successful. | |
135 | */ | |
136 | static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem, | |
137 | struct videobuf_buffer *vb) | |
138 | { | |
139 | struct mm_struct *mm = current->mm; | |
140 | struct vm_area_struct *vma; | |
141 | unsigned long prev_pfn, this_pfn; | |
142 | unsigned long pages_done, user_address; | |
143 | int ret; | |
144 | ||
145 | mem->size = PAGE_ALIGN(vb->size); | |
146 | mem->is_userptr = 0; | |
147 | ret = -EINVAL; | |
148 | ||
149 | down_read(&mm->mmap_sem); | |
150 | ||
151 | vma = find_vma(mm, vb->baddr); | |
152 | if (!vma) | |
153 | goto out_up; | |
154 | ||
155 | if ((vb->baddr + mem->size) > vma->vm_end) | |
156 | goto out_up; | |
157 | ||
158 | pages_done = 0; | |
159 | prev_pfn = 0; /* kill warning */ | |
160 | user_address = vb->baddr; | |
161 | ||
162 | while (pages_done < (mem->size >> PAGE_SHIFT)) { | |
163 | ret = follow_pfn(vma, user_address, &this_pfn); | |
164 | if (ret) | |
165 | break; | |
166 | ||
167 | if (pages_done == 0) | |
168 | mem->dma_handle = this_pfn << PAGE_SHIFT; | |
169 | else if (this_pfn != (prev_pfn + 1)) | |
170 | ret = -EFAULT; | |
171 | ||
172 | if (ret) | |
173 | break; | |
174 | ||
175 | prev_pfn = this_pfn; | |
176 | user_address += PAGE_SIZE; | |
177 | pages_done++; | |
178 | } | |
179 | ||
180 | if (!ret) | |
181 | mem->is_userptr = 1; | |
182 | ||
183 | out_up: | |
184 | up_read(¤t->mm->mmap_sem); | |
185 | ||
186 | return ret; | |
187 | } | |
188 | ||
2cc45cf2 MD |
189 | static void *__videobuf_alloc(size_t size) |
190 | { | |
191 | struct videobuf_dma_contig_memory *mem; | |
192 | struct videobuf_buffer *vb; | |
193 | ||
194 | vb = kzalloc(size + sizeof(*mem), GFP_KERNEL); | |
195 | if (vb) { | |
196 | mem = vb->priv = ((char *)vb) + size; | |
197 | mem->magic = MAGIC_DC_MEM; | |
198 | } | |
199 | ||
200 | return vb; | |
201 | } | |
202 | ||
203 | static void *__videobuf_to_vmalloc(struct videobuf_buffer *buf) | |
204 | { | |
205 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
206 | ||
207 | BUG_ON(!mem); | |
208 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
209 | ||
210 | return mem->vaddr; | |
211 | } | |
212 | ||
213 | static int __videobuf_iolock(struct videobuf_queue *q, | |
214 | struct videobuf_buffer *vb, | |
215 | struct v4l2_framebuffer *fbuf) | |
216 | { | |
217 | struct videobuf_dma_contig_memory *mem = vb->priv; | |
218 | ||
219 | BUG_ON(!mem); | |
220 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
221 | ||
222 | switch (vb->memory) { | |
223 | case V4L2_MEMORY_MMAP: | |
224 | dev_dbg(q->dev, "%s memory method MMAP\n", __func__); | |
225 | ||
226 | /* All handling should be done by __videobuf_mmap_mapper() */ | |
227 | if (!mem->vaddr) { | |
228 | dev_err(q->dev, "memory is not alloced/mmapped.\n"); | |
229 | return -EINVAL; | |
230 | } | |
231 | break; | |
232 | case V4L2_MEMORY_USERPTR: | |
233 | dev_dbg(q->dev, "%s memory method USERPTR\n", __func__); | |
234 | ||
720b17e7 | 235 | /* handle pointer from user space */ |
2cc45cf2 | 236 | if (vb->baddr) |
720b17e7 | 237 | return videobuf_dma_contig_user_get(mem, vb); |
2cc45cf2 | 238 | |
720b17e7 | 239 | /* allocate memory for the read() method */ |
2cc45cf2 MD |
240 | mem->size = PAGE_ALIGN(vb->size); |
241 | mem->vaddr = dma_alloc_coherent(q->dev, mem->size, | |
242 | &mem->dma_handle, GFP_KERNEL); | |
243 | if (!mem->vaddr) { | |
244 | dev_err(q->dev, "dma_alloc_coherent %ld failed\n", | |
245 | mem->size); | |
246 | return -ENOMEM; | |
247 | } | |
248 | ||
249 | dev_dbg(q->dev, "dma_alloc_coherent data is at %p (%ld)\n", | |
250 | mem->vaddr, mem->size); | |
251 | break; | |
252 | case V4L2_MEMORY_OVERLAY: | |
253 | default: | |
254 | dev_dbg(q->dev, "%s memory method OVERLAY/unknown\n", | |
255 | __func__); | |
256 | return -EINVAL; | |
257 | } | |
258 | ||
259 | return 0; | |
260 | } | |
261 | ||
2cc45cf2 MD |
262 | static int __videobuf_mmap_free(struct videobuf_queue *q) |
263 | { | |
264 | unsigned int i; | |
265 | ||
266 | dev_dbg(q->dev, "%s\n", __func__); | |
267 | for (i = 0; i < VIDEO_MAX_FRAME; i++) { | |
268 | if (q->bufs[i] && q->bufs[i]->map) | |
269 | return -EBUSY; | |
270 | } | |
271 | ||
272 | return 0; | |
273 | } | |
274 | ||
275 | static int __videobuf_mmap_mapper(struct videobuf_queue *q, | |
276 | struct vm_area_struct *vma) | |
277 | { | |
278 | struct videobuf_dma_contig_memory *mem; | |
279 | struct videobuf_mapping *map; | |
280 | unsigned int first; | |
281 | int retval; | |
282 | unsigned long size, offset = vma->vm_pgoff << PAGE_SHIFT; | |
283 | ||
284 | dev_dbg(q->dev, "%s\n", __func__); | |
285 | if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) | |
286 | return -EINVAL; | |
287 | ||
288 | /* look for first buffer to map */ | |
289 | for (first = 0; first < VIDEO_MAX_FRAME; first++) { | |
290 | if (!q->bufs[first]) | |
291 | continue; | |
292 | ||
293 | if (V4L2_MEMORY_MMAP != q->bufs[first]->memory) | |
294 | continue; | |
295 | if (q->bufs[first]->boff == offset) | |
296 | break; | |
297 | } | |
298 | if (VIDEO_MAX_FRAME == first) { | |
299 | dev_dbg(q->dev, "invalid user space offset [offset=0x%lx]\n", | |
300 | offset); | |
301 | return -EINVAL; | |
302 | } | |
303 | ||
304 | /* create mapping + update buffer list */ | |
305 | map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL); | |
306 | if (!map) | |
307 | return -ENOMEM; | |
308 | ||
309 | q->bufs[first]->map = map; | |
310 | map->start = vma->vm_start; | |
311 | map->end = vma->vm_end; | |
312 | map->q = q; | |
313 | ||
314 | q->bufs[first]->baddr = vma->vm_start; | |
315 | ||
316 | mem = q->bufs[first]->priv; | |
317 | BUG_ON(!mem); | |
318 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
319 | ||
320 | mem->size = PAGE_ALIGN(q->bufs[first]->bsize); | |
321 | mem->vaddr = dma_alloc_coherent(q->dev, mem->size, | |
322 | &mem->dma_handle, GFP_KERNEL); | |
323 | if (!mem->vaddr) { | |
324 | dev_err(q->dev, "dma_alloc_coherent size %ld failed\n", | |
325 | mem->size); | |
326 | goto error; | |
327 | } | |
328 | dev_dbg(q->dev, "dma_alloc_coherent data is at addr %p (size %ld)\n", | |
329 | mem->vaddr, mem->size); | |
330 | ||
331 | /* Try to remap memory */ | |
332 | ||
333 | size = vma->vm_end - vma->vm_start; | |
334 | size = (size < mem->size) ? size : mem->size; | |
335 | ||
336 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); | |
337 | retval = remap_pfn_range(vma, vma->vm_start, | |
338 | mem->dma_handle >> PAGE_SHIFT, | |
339 | size, vma->vm_page_prot); | |
340 | if (retval) { | |
341 | dev_err(q->dev, "mmap: remap failed with error %d. ", retval); | |
342 | dma_free_coherent(q->dev, mem->size, | |
343 | mem->vaddr, mem->dma_handle); | |
344 | goto error; | |
345 | } | |
346 | ||
347 | vma->vm_ops = &videobuf_vm_ops; | |
348 | vma->vm_flags |= VM_DONTEXPAND; | |
349 | vma->vm_private_data = map; | |
350 | ||
351 | dev_dbg(q->dev, "mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n", | |
352 | map, q, vma->vm_start, vma->vm_end, | |
353 | (long int) q->bufs[first]->bsize, | |
354 | vma->vm_pgoff, first); | |
355 | ||
356 | videobuf_vm_open(vma); | |
357 | ||
358 | return 0; | |
359 | ||
360 | error: | |
361 | kfree(map); | |
362 | return -ENOMEM; | |
363 | } | |
364 | ||
365 | static int __videobuf_copy_to_user(struct videobuf_queue *q, | |
366 | char __user *data, size_t count, | |
367 | int nonblocking) | |
368 | { | |
369 | struct videobuf_dma_contig_memory *mem = q->read_buf->priv; | |
370 | void *vaddr; | |
371 | ||
372 | BUG_ON(!mem); | |
373 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
374 | BUG_ON(!mem->vaddr); | |
375 | ||
376 | /* copy to userspace */ | |
377 | if (count > q->read_buf->size - q->read_off) | |
378 | count = q->read_buf->size - q->read_off; | |
379 | ||
380 | vaddr = mem->vaddr; | |
381 | ||
382 | if (copy_to_user(data, vaddr + q->read_off, count)) | |
383 | return -EFAULT; | |
384 | ||
385 | return count; | |
386 | } | |
387 | ||
388 | static int __videobuf_copy_stream(struct videobuf_queue *q, | |
389 | char __user *data, size_t count, size_t pos, | |
390 | int vbihack, int nonblocking) | |
391 | { | |
392 | unsigned int *fc; | |
393 | struct videobuf_dma_contig_memory *mem = q->read_buf->priv; | |
394 | ||
395 | BUG_ON(!mem); | |
396 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
397 | ||
398 | if (vbihack) { | |
399 | /* dirty, undocumented hack -- pass the frame counter | |
400 | * within the last four bytes of each vbi data block. | |
401 | * We need that one to maintain backward compatibility | |
402 | * to all vbi decoding software out there ... */ | |
403 | fc = (unsigned int *)mem->vaddr; | |
404 | fc += (q->read_buf->size >> 2) - 1; | |
405 | *fc = q->read_buf->field_count >> 1; | |
406 | dev_dbg(q->dev, "vbihack: %d\n", *fc); | |
407 | } | |
408 | ||
409 | /* copy stuff using the common method */ | |
410 | count = __videobuf_copy_to_user(q, data, count, nonblocking); | |
411 | ||
412 | if ((count == -EFAULT) && (pos == 0)) | |
413 | return -EFAULT; | |
414 | ||
415 | return count; | |
416 | } | |
417 | ||
418 | static struct videobuf_qtype_ops qops = { | |
419 | .magic = MAGIC_QTYPE_OPS, | |
420 | ||
421 | .alloc = __videobuf_alloc, | |
422 | .iolock = __videobuf_iolock, | |
2cc45cf2 MD |
423 | .mmap_free = __videobuf_mmap_free, |
424 | .mmap_mapper = __videobuf_mmap_mapper, | |
425 | .video_copy_to_user = __videobuf_copy_to_user, | |
426 | .copy_stream = __videobuf_copy_stream, | |
427 | .vmalloc = __videobuf_to_vmalloc, | |
428 | }; | |
429 | ||
430 | void videobuf_queue_dma_contig_init(struct videobuf_queue *q, | |
431 | struct videobuf_queue_ops *ops, | |
432 | struct device *dev, | |
433 | spinlock_t *irqlock, | |
434 | enum v4l2_buf_type type, | |
435 | enum v4l2_field field, | |
436 | unsigned int msize, | |
437 | void *priv) | |
438 | { | |
439 | videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize, | |
440 | priv, &qops); | |
441 | } | |
442 | EXPORT_SYMBOL_GPL(videobuf_queue_dma_contig_init); | |
443 | ||
444 | dma_addr_t videobuf_to_dma_contig(struct videobuf_buffer *buf) | |
445 | { | |
446 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
447 | ||
448 | BUG_ON(!mem); | |
449 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
450 | ||
451 | return mem->dma_handle; | |
452 | } | |
453 | EXPORT_SYMBOL_GPL(videobuf_to_dma_contig); | |
454 | ||
455 | void videobuf_dma_contig_free(struct videobuf_queue *q, | |
456 | struct videobuf_buffer *buf) | |
457 | { | |
458 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
459 | ||
460 | /* mmapped memory can't be freed here, otherwise mmapped region | |
461 | would be released, while still needed. In this case, the memory | |
462 | release should happen inside videobuf_vm_close(). | |
463 | So, it should free memory only if the memory were allocated for | |
464 | read() operation. | |
465 | */ | |
720b17e7 | 466 | if (buf->memory != V4L2_MEMORY_USERPTR) |
2cc45cf2 MD |
467 | return; |
468 | ||
469 | if (!mem) | |
470 | return; | |
471 | ||
472 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
473 | ||
720b17e7 MD |
474 | /* handle user space pointer case */ |
475 | if (buf->baddr) { | |
476 | videobuf_dma_contig_user_put(mem); | |
477 | return; | |
478 | } | |
479 | ||
480 | /* read() method */ | |
2cc45cf2 MD |
481 | dma_free_coherent(q->dev, mem->size, mem->vaddr, mem->dma_handle); |
482 | mem->vaddr = NULL; | |
483 | } | |
484 | EXPORT_SYMBOL_GPL(videobuf_dma_contig_free); | |
485 | ||
486 | MODULE_DESCRIPTION("helper module to manage video4linux dma contig buffers"); | |
487 | MODULE_AUTHOR("Magnus Damm"); | |
488 | MODULE_LICENSE("GPL"); |