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 | 21 | #include <linux/dma-mapping.h> |
f39c1ab3 | 22 | #include <linux/sched.h> |
2cc45cf2 MD |
23 | #include <media/videobuf-dma-contig.h> |
24 | ||
25 | struct videobuf_dma_contig_memory { | |
26 | u32 magic; | |
27 | void *vaddr; | |
28 | dma_addr_t dma_handle; | |
29 | unsigned long size; | |
720b17e7 | 30 | int is_userptr; |
2cc45cf2 MD |
31 | }; |
32 | ||
33 | #define MAGIC_DC_MEM 0x0733ac61 | |
c60f2b5c GL |
34 | #define MAGIC_CHECK(is, should) \ |
35 | if (unlikely((is) != (should))) { \ | |
36 | pr_err("magic mismatch: %x expected %x\n", (is), (should)); \ | |
37 | BUG(); \ | |
2cc45cf2 MD |
38 | } |
39 | ||
40 | static void | |
41 | videobuf_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 | ||
51 | static 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 | /* We need first to cancel streams, before unmapping */ | |
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 | /* This callback is called only if kernel has | |
81 | allocated memory and this memory is mmapped. | |
82 | In this case, memory should be freed, | |
83 | in order to do memory unmap. | |
84 | */ | |
85 | ||
86 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
87 | ||
88 | /* vfree is not atomic - can't be | |
89 | called with IRQ's disabled | |
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 | ||
f0f37e2f | 109 | static const struct vm_operations_struct videobuf_vm_ops = { |
2cc45cf2 MD |
110 | .open = videobuf_vm_open, |
111 | .close = videobuf_vm_close, | |
112 | }; | |
113 | ||
720b17e7 MD |
114 | /** |
115 | * videobuf_dma_contig_user_put() - reset pointer to user space buffer | |
116 | * @mem: per-buffer private videobuf-dma-contig data | |
117 | * | |
118 | * This function resets the user space pointer | |
119 | */ | |
120 | static 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 | * videobuf_dma_contig_user_get() - setup user space memory pointer | |
129 | * @mem: per-buffer private videobuf-dma-contig data | |
130 | * @vb: video buffer to map | |
131 | * | |
132 | * This function validates and sets up a pointer to user space memory. | |
133 | * Only physically contiguous pfn-mapped memory is accepted. | |
134 | * | |
135 | * Returns 0 if successful. | |
136 | */ | |
137 | static 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; /* kill warning */ | |
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 | ||
2cc45cf2 MD |
190 | static 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 | ||
204 | static 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 | ||
214 | static 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 | /* All handling should be done by __videobuf_mmap_mapper() */ | |
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 | ||
720b17e7 | 236 | /* handle pointer from user space */ |
2cc45cf2 | 237 | if (vb->baddr) |
720b17e7 | 238 | return videobuf_dma_contig_user_get(mem, vb); |
2cc45cf2 | 239 | |
720b17e7 | 240 | /* allocate memory for the read() method */ |
2cc45cf2 MD |
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 | ||
2cc45cf2 MD |
263 | static 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 | ||
276 | static 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 | /* look for first buffer to map */ | |
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 | /* create mapping + update buffer list */ | |
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 | /* Try to remap memory */ | |
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 | ||
361 | error: | |
362 | kfree(map); | |
363 | return -ENOMEM; | |
364 | } | |
365 | ||
366 | static 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 | /* copy to userspace */ | |
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 | ||
389 | static 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 | /* dirty, undocumented hack -- pass the frame counter | |
401 | * within the last four bytes of each vbi data block. | |
402 | * We need that one to maintain backward compatibility | |
403 | * to all vbi decoding software out there ... */ | |
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 | /* copy stuff using the common method */ | |
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 | ||
419 | static struct videobuf_qtype_ops qops = { | |
420 | .magic = MAGIC_QTYPE_OPS, | |
421 | ||
422 | .alloc = __videobuf_alloc, | |
423 | .iolock = __videobuf_iolock, | |
2cc45cf2 MD |
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 | ||
431 | void 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 | } | |
443 | EXPORT_SYMBOL_GPL(videobuf_queue_dma_contig_init); | |
444 | ||
445 | dma_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 | } | |
454 | EXPORT_SYMBOL_GPL(videobuf_to_dma_contig); | |
455 | ||
456 | void 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 | /* mmapped memory can't be freed here, otherwise mmapped region | |
462 | would be released, while still needed. In this case, the memory | |
463 | release should happen inside videobuf_vm_close(). | |
464 | So, it should free memory only if the memory were allocated for | |
465 | read() operation. | |
466 | */ | |
720b17e7 | 467 | if (buf->memory != V4L2_MEMORY_USERPTR) |
2cc45cf2 MD |
468 | return; |
469 | ||
470 | if (!mem) | |
471 | return; | |
472 | ||
473 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
474 | ||
720b17e7 MD |
475 | /* handle user space pointer case */ |
476 | if (buf->baddr) { | |
477 | videobuf_dma_contig_user_put(mem); | |
478 | return; | |
479 | } | |
480 | ||
481 | /* read() method */ | |
2cc45cf2 MD |
482 | dma_free_coherent(q->dev, mem->size, mem->vaddr, mem->dma_handle); |
483 | mem->vaddr = NULL; | |
484 | } | |
485 | EXPORT_SYMBOL_GPL(videobuf_dma_contig_free); | |
486 | ||
487 | MODULE_DESCRIPTION("helper module to manage video4linux dma contig buffers"); | |
488 | MODULE_AUTHOR("Magnus Damm"); | |
489 | MODULE_LICENSE("GPL"); |