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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> |
5a0e3ad6 | 23 | #include <linux/slab.h> |
2cc45cf2 MD |
24 | #include <media/videobuf-dma-contig.h> |
25 | ||
26 | struct videobuf_dma_contig_memory { | |
27 | u32 magic; | |
28 | void *vaddr; | |
29 | dma_addr_t dma_handle; | |
a8f3c203 | 30 | bool cached; |
2cc45cf2 MD |
31 | unsigned long size; |
32 | }; | |
33 | ||
34 | #define MAGIC_DC_MEM 0x0733ac61 | |
c60f2b5c GL |
35 | #define MAGIC_CHECK(is, should) \ |
36 | if (unlikely((is) != (should))) { \ | |
37 | pr_err("magic mismatch: %x expected %x\n", (is), (should)); \ | |
38 | BUG(); \ | |
2cc45cf2 MD |
39 | } |
40 | ||
a8f3c203 FV |
41 | static int __videobuf_dc_alloc(struct device *dev, |
42 | struct videobuf_dma_contig_memory *mem, | |
43 | unsigned long size, unsigned long flags) | |
44 | { | |
45 | mem->size = size; | |
46 | if (mem->cached) { | |
47 | mem->vaddr = alloc_pages_exact(mem->size, flags | GFP_DMA); | |
48 | if (mem->vaddr) { | |
49 | int err; | |
50 | ||
51 | mem->dma_handle = dma_map_single(dev, mem->vaddr, | |
52 | mem->size, | |
53 | DMA_FROM_DEVICE); | |
54 | err = dma_mapping_error(dev, mem->dma_handle); | |
55 | if (err) { | |
56 | dev_err(dev, "dma_map_single failed\n"); | |
57 | ||
58 | free_pages_exact(mem->vaddr, mem->size); | |
59 | mem->vaddr = 0; | |
60 | return err; | |
61 | } | |
62 | } | |
63 | } else | |
64 | mem->vaddr = dma_alloc_coherent(dev, mem->size, | |
65 | &mem->dma_handle, flags); | |
66 | ||
67 | if (!mem->vaddr) { | |
68 | dev_err(dev, "memory alloc size %ld failed\n", mem->size); | |
69 | return -ENOMEM; | |
70 | } | |
71 | ||
72 | dev_dbg(dev, "dma mapped data is at %p (%ld)\n", mem->vaddr, mem->size); | |
73 | ||
74 | return 0; | |
75 | } | |
76 | ||
77 | static void __videobuf_dc_free(struct device *dev, | |
78 | struct videobuf_dma_contig_memory *mem) | |
79 | { | |
80 | if (mem->cached) { | |
81 | if (!mem->vaddr) | |
82 | return; | |
83 | dma_unmap_single(dev, mem->dma_handle, mem->size, | |
84 | DMA_FROM_DEVICE); | |
85 | free_pages_exact(mem->vaddr, mem->size); | |
86 | } else | |
87 | dma_free_coherent(dev, mem->size, mem->vaddr, mem->dma_handle); | |
88 | ||
89 | mem->vaddr = NULL; | |
90 | } | |
91 | ||
92 | static void videobuf_vm_open(struct vm_area_struct *vma) | |
2cc45cf2 MD |
93 | { |
94 | struct videobuf_mapping *map = vma->vm_private_data; | |
95 | ||
96 | dev_dbg(map->q->dev, "vm_open %p [count=%u,vma=%08lx-%08lx]\n", | |
97 | map, map->count, vma->vm_start, vma->vm_end); | |
98 | ||
99 | map->count++; | |
100 | } | |
101 | ||
102 | static void videobuf_vm_close(struct vm_area_struct *vma) | |
103 | { | |
104 | struct videobuf_mapping *map = vma->vm_private_data; | |
105 | struct videobuf_queue *q = map->q; | |
106 | int i; | |
107 | ||
f35f1bb8 | 108 | dev_dbg(q->dev, "vm_close %p [count=%u,vma=%08lx-%08lx]\n", |
2cc45cf2 MD |
109 | map, map->count, vma->vm_start, vma->vm_end); |
110 | ||
111 | map->count--; | |
112 | if (0 == map->count) { | |
113 | struct videobuf_dma_contig_memory *mem; | |
114 | ||
f35f1bb8 | 115 | dev_dbg(q->dev, "munmap %p q=%p\n", map, q); |
97397687 | 116 | videobuf_queue_lock(q); |
2cc45cf2 MD |
117 | |
118 | /* We need first to cancel streams, before unmapping */ | |
119 | if (q->streaming) | |
120 | videobuf_queue_cancel(q); | |
121 | ||
122 | for (i = 0; i < VIDEO_MAX_FRAME; i++) { | |
123 | if (NULL == q->bufs[i]) | |
124 | continue; | |
125 | ||
126 | if (q->bufs[i]->map != map) | |
127 | continue; | |
128 | ||
129 | mem = q->bufs[i]->priv; | |
130 | if (mem) { | |
131 | /* This callback is called only if kernel has | |
132 | allocated memory and this memory is mmapped. | |
133 | In this case, memory should be freed, | |
134 | in order to do memory unmap. | |
135 | */ | |
136 | ||
137 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
138 | ||
139 | /* vfree is not atomic - can't be | |
140 | called with IRQ's disabled | |
141 | */ | |
f35f1bb8 | 142 | dev_dbg(q->dev, "buf[%d] freeing %p\n", |
2cc45cf2 MD |
143 | i, mem->vaddr); |
144 | ||
a8f3c203 | 145 | __videobuf_dc_free(q->dev, mem); |
2cc45cf2 MD |
146 | mem->vaddr = NULL; |
147 | } | |
148 | ||
a8f3c203 | 149 | q->bufs[i]->map = NULL; |
2cc45cf2 MD |
150 | q->bufs[i]->baddr = 0; |
151 | } | |
152 | ||
153 | kfree(map); | |
154 | ||
97397687 | 155 | videobuf_queue_unlock(q); |
2cc45cf2 MD |
156 | } |
157 | } | |
158 | ||
f0f37e2f | 159 | static const struct vm_operations_struct videobuf_vm_ops = { |
a8f3c203 FV |
160 | .open = videobuf_vm_open, |
161 | .close = videobuf_vm_close, | |
2cc45cf2 MD |
162 | }; |
163 | ||
720b17e7 MD |
164 | /** |
165 | * videobuf_dma_contig_user_put() - reset pointer to user space buffer | |
166 | * @mem: per-buffer private videobuf-dma-contig data | |
167 | * | |
168 | * This function resets the user space pointer | |
169 | */ | |
170 | static void videobuf_dma_contig_user_put(struct videobuf_dma_contig_memory *mem) | |
171 | { | |
720b17e7 MD |
172 | mem->dma_handle = 0; |
173 | mem->size = 0; | |
174 | } | |
175 | ||
176 | /** | |
177 | * videobuf_dma_contig_user_get() - setup user space memory pointer | |
178 | * @mem: per-buffer private videobuf-dma-contig data | |
179 | * @vb: video buffer to map | |
180 | * | |
181 | * This function validates and sets up a pointer to user space memory. | |
182 | * Only physically contiguous pfn-mapped memory is accepted. | |
183 | * | |
184 | * Returns 0 if successful. | |
185 | */ | |
186 | static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem, | |
187 | struct videobuf_buffer *vb) | |
188 | { | |
189 | struct mm_struct *mm = current->mm; | |
190 | struct vm_area_struct *vma; | |
191 | unsigned long prev_pfn, this_pfn; | |
192 | unsigned long pages_done, user_address; | |
31bedfa5 | 193 | unsigned int offset; |
720b17e7 MD |
194 | int ret; |
195 | ||
31bedfa5 MK |
196 | offset = vb->baddr & ~PAGE_MASK; |
197 | mem->size = PAGE_ALIGN(vb->size + offset); | |
720b17e7 MD |
198 | ret = -EINVAL; |
199 | ||
200 | down_read(&mm->mmap_sem); | |
201 | ||
202 | vma = find_vma(mm, vb->baddr); | |
203 | if (!vma) | |
204 | goto out_up; | |
205 | ||
206 | if ((vb->baddr + mem->size) > vma->vm_end) | |
207 | goto out_up; | |
208 | ||
209 | pages_done = 0; | |
210 | prev_pfn = 0; /* kill warning */ | |
211 | user_address = vb->baddr; | |
212 | ||
213 | while (pages_done < (mem->size >> PAGE_SHIFT)) { | |
214 | ret = follow_pfn(vma, user_address, &this_pfn); | |
215 | if (ret) | |
216 | break; | |
217 | ||
218 | if (pages_done == 0) | |
31bedfa5 | 219 | mem->dma_handle = (this_pfn << PAGE_SHIFT) + offset; |
720b17e7 MD |
220 | else if (this_pfn != (prev_pfn + 1)) |
221 | ret = -EFAULT; | |
222 | ||
223 | if (ret) | |
224 | break; | |
225 | ||
226 | prev_pfn = this_pfn; | |
227 | user_address += PAGE_SIZE; | |
228 | pages_done++; | |
229 | } | |
230 | ||
a8f3c203 | 231 | out_up: |
720b17e7 MD |
232 | up_read(¤t->mm->mmap_sem); |
233 | ||
234 | return ret; | |
235 | } | |
236 | ||
a8f3c203 | 237 | static struct videobuf_buffer *__videobuf_alloc_vb(size_t size, bool cached) |
2cc45cf2 MD |
238 | { |
239 | struct videobuf_dma_contig_memory *mem; | |
240 | struct videobuf_buffer *vb; | |
241 | ||
242 | vb = kzalloc(size + sizeof(*mem), GFP_KERNEL); | |
243 | if (vb) { | |
a8f3c203 FV |
244 | vb->priv = ((char *)vb) + size; |
245 | mem = vb->priv; | |
2cc45cf2 | 246 | mem->magic = MAGIC_DC_MEM; |
a8f3c203 | 247 | mem->cached = cached; |
2cc45cf2 MD |
248 | } |
249 | ||
250 | return vb; | |
251 | } | |
252 | ||
a8f3c203 FV |
253 | static struct videobuf_buffer *__videobuf_alloc_uncached(size_t size) |
254 | { | |
255 | return __videobuf_alloc_vb(size, false); | |
256 | } | |
257 | ||
258 | static struct videobuf_buffer *__videobuf_alloc_cached(size_t size) | |
259 | { | |
260 | return __videobuf_alloc_vb(size, true); | |
261 | } | |
262 | ||
037c75eb | 263 | static void *__videobuf_to_vaddr(struct videobuf_buffer *buf) |
2cc45cf2 MD |
264 | { |
265 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
266 | ||
267 | BUG_ON(!mem); | |
268 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
269 | ||
270 | return mem->vaddr; | |
271 | } | |
272 | ||
273 | static int __videobuf_iolock(struct videobuf_queue *q, | |
274 | struct videobuf_buffer *vb, | |
275 | struct v4l2_framebuffer *fbuf) | |
276 | { | |
277 | struct videobuf_dma_contig_memory *mem = vb->priv; | |
278 | ||
279 | BUG_ON(!mem); | |
280 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
281 | ||
282 | switch (vb->memory) { | |
283 | case V4L2_MEMORY_MMAP: | |
284 | dev_dbg(q->dev, "%s memory method MMAP\n", __func__); | |
285 | ||
286 | /* All handling should be done by __videobuf_mmap_mapper() */ | |
287 | if (!mem->vaddr) { | |
288 | dev_err(q->dev, "memory is not alloced/mmapped.\n"); | |
289 | return -EINVAL; | |
290 | } | |
291 | break; | |
292 | case V4L2_MEMORY_USERPTR: | |
293 | dev_dbg(q->dev, "%s memory method USERPTR\n", __func__); | |
294 | ||
720b17e7 | 295 | /* handle pointer from user space */ |
2cc45cf2 | 296 | if (vb->baddr) |
720b17e7 | 297 | return videobuf_dma_contig_user_get(mem, vb); |
2cc45cf2 | 298 | |
720b17e7 | 299 | /* allocate memory for the read() method */ |
a8f3c203 FV |
300 | if (__videobuf_dc_alloc(q->dev, mem, PAGE_ALIGN(vb->size), |
301 | GFP_KERNEL)) | |
2cc45cf2 | 302 | return -ENOMEM; |
2cc45cf2 MD |
303 | break; |
304 | case V4L2_MEMORY_OVERLAY: | |
305 | default: | |
a8f3c203 | 306 | dev_dbg(q->dev, "%s memory method OVERLAY/unknown\n", __func__); |
2cc45cf2 MD |
307 | return -EINVAL; |
308 | } | |
309 | ||
310 | return 0; | |
311 | } | |
312 | ||
a8f3c203 FV |
313 | static int __videobuf_sync(struct videobuf_queue *q, |
314 | struct videobuf_buffer *buf) | |
315 | { | |
316 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
317 | BUG_ON(!mem); | |
318 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
319 | ||
320 | dma_sync_single_for_cpu(q->dev, mem->dma_handle, mem->size, | |
321 | DMA_FROM_DEVICE); | |
322 | ||
323 | return 0; | |
324 | } | |
325 | ||
2cc45cf2 | 326 | static int __videobuf_mmap_mapper(struct videobuf_queue *q, |
0b62b737 | 327 | struct videobuf_buffer *buf, |
2cc45cf2 MD |
328 | struct vm_area_struct *vma) |
329 | { | |
330 | struct videobuf_dma_contig_memory *mem; | |
331 | struct videobuf_mapping *map; | |
2cc45cf2 | 332 | int retval; |
0b62b737 | 333 | unsigned long size; |
a8f3c203 FV |
334 | unsigned long pos, start = vma->vm_start; |
335 | struct page *page; | |
2cc45cf2 MD |
336 | |
337 | dev_dbg(q->dev, "%s\n", __func__); | |
2cc45cf2 MD |
338 | |
339 | /* create mapping + update buffer list */ | |
340 | map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL); | |
341 | if (!map) | |
342 | return -ENOMEM; | |
343 | ||
0b62b737 | 344 | buf->map = map; |
2cc45cf2 MD |
345 | map->q = q; |
346 | ||
0b62b737 | 347 | buf->baddr = vma->vm_start; |
2cc45cf2 | 348 | |
0b62b737 | 349 | mem = buf->priv; |
2cc45cf2 MD |
350 | BUG_ON(!mem); |
351 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
352 | ||
a8f3c203 FV |
353 | if (__videobuf_dc_alloc(q->dev, mem, PAGE_ALIGN(buf->bsize), |
354 | GFP_KERNEL | __GFP_COMP)) | |
2cc45cf2 | 355 | goto error; |
2cc45cf2 MD |
356 | |
357 | /* Try to remap memory */ | |
358 | ||
359 | size = vma->vm_end - vma->vm_start; | |
360 | size = (size < mem->size) ? size : mem->size; | |
361 | ||
a8f3c203 FV |
362 | if (!mem->cached) |
363 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); | |
364 | ||
365 | pos = (unsigned long)mem->vaddr; | |
366 | ||
367 | while (size > 0) { | |
368 | page = virt_to_page((void *)pos); | |
369 | if (NULL == page) { | |
370 | dev_err(q->dev, "mmap: virt_to_page failed\n"); | |
371 | __videobuf_dc_free(q->dev, mem); | |
372 | goto error; | |
373 | } | |
374 | retval = vm_insert_page(vma, start, page); | |
375 | if (retval) { | |
376 | dev_err(q->dev, "mmap: insert failed with error %d\n", | |
377 | retval); | |
378 | __videobuf_dc_free(q->dev, mem); | |
379 | goto error; | |
380 | } | |
381 | start += PAGE_SIZE; | |
382 | pos += PAGE_SIZE; | |
383 | ||
384 | if (size > PAGE_SIZE) | |
385 | size -= PAGE_SIZE; | |
386 | else | |
387 | size = 0; | |
2cc45cf2 MD |
388 | } |
389 | ||
a8f3c203 FV |
390 | vma->vm_ops = &videobuf_vm_ops; |
391 | vma->vm_flags |= VM_DONTEXPAND; | |
2cc45cf2 MD |
392 | vma->vm_private_data = map; |
393 | ||
394 | dev_dbg(q->dev, "mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n", | |
395 | map, q, vma->vm_start, vma->vm_end, | |
a8f3c203 | 396 | (long int)buf->bsize, vma->vm_pgoff, buf->i); |
2cc45cf2 MD |
397 | |
398 | videobuf_vm_open(vma); | |
399 | ||
400 | return 0; | |
401 | ||
402 | error: | |
403 | kfree(map); | |
404 | return -ENOMEM; | |
405 | } | |
406 | ||
2cc45cf2 | 407 | static struct videobuf_qtype_ops qops = { |
a8f3c203 FV |
408 | .magic = MAGIC_QTYPE_OPS, |
409 | .alloc_vb = __videobuf_alloc_uncached, | |
410 | .iolock = __videobuf_iolock, | |
411 | .mmap_mapper = __videobuf_mmap_mapper, | |
412 | .vaddr = __videobuf_to_vaddr, | |
413 | }; | |
2cc45cf2 | 414 | |
a8f3c203 FV |
415 | static struct videobuf_qtype_ops qops_cached = { |
416 | .magic = MAGIC_QTYPE_OPS, | |
417 | .alloc_vb = __videobuf_alloc_cached, | |
418 | .iolock = __videobuf_iolock, | |
419 | .sync = __videobuf_sync, | |
420 | .mmap_mapper = __videobuf_mmap_mapper, | |
421 | .vaddr = __videobuf_to_vaddr, | |
2cc45cf2 MD |
422 | }; |
423 | ||
424 | void videobuf_queue_dma_contig_init(struct videobuf_queue *q, | |
38a54f35 | 425 | const struct videobuf_queue_ops *ops, |
2cc45cf2 MD |
426 | struct device *dev, |
427 | spinlock_t *irqlock, | |
428 | enum v4l2_buf_type type, | |
429 | enum v4l2_field field, | |
430 | unsigned int msize, | |
08bff03e HV |
431 | void *priv, |
432 | struct mutex *ext_lock) | |
2cc45cf2 MD |
433 | { |
434 | videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize, | |
08bff03e | 435 | priv, &qops, ext_lock); |
2cc45cf2 MD |
436 | } |
437 | EXPORT_SYMBOL_GPL(videobuf_queue_dma_contig_init); | |
438 | ||
a8f3c203 FV |
439 | void videobuf_queue_dma_contig_init_cached(struct videobuf_queue *q, |
440 | const struct videobuf_queue_ops *ops, | |
441 | struct device *dev, | |
442 | spinlock_t *irqlock, | |
443 | enum v4l2_buf_type type, | |
444 | enum v4l2_field field, | |
445 | unsigned int msize, | |
446 | void *priv, struct mutex *ext_lock) | |
447 | { | |
448 | videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize, | |
449 | priv, &qops_cached, ext_lock); | |
450 | } | |
451 | EXPORT_SYMBOL_GPL(videobuf_queue_dma_contig_init_cached); | |
452 | ||
2cc45cf2 MD |
453 | dma_addr_t videobuf_to_dma_contig(struct videobuf_buffer *buf) |
454 | { | |
455 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
456 | ||
457 | BUG_ON(!mem); | |
458 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
459 | ||
460 | return mem->dma_handle; | |
461 | } | |
462 | EXPORT_SYMBOL_GPL(videobuf_to_dma_contig); | |
463 | ||
464 | void videobuf_dma_contig_free(struct videobuf_queue *q, | |
465 | struct videobuf_buffer *buf) | |
466 | { | |
467 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
468 | ||
469 | /* mmapped memory can't be freed here, otherwise mmapped region | |
470 | would be released, while still needed. In this case, the memory | |
471 | release should happen inside videobuf_vm_close(). | |
472 | So, it should free memory only if the memory were allocated for | |
473 | read() operation. | |
474 | */ | |
720b17e7 | 475 | if (buf->memory != V4L2_MEMORY_USERPTR) |
2cc45cf2 MD |
476 | return; |
477 | ||
478 | if (!mem) | |
479 | return; | |
480 | ||
481 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
482 | ||
720b17e7 MD |
483 | /* handle user space pointer case */ |
484 | if (buf->baddr) { | |
485 | videobuf_dma_contig_user_put(mem); | |
486 | return; | |
487 | } | |
488 | ||
489 | /* read() method */ | |
b2b476f5 | 490 | if (mem->vaddr) { |
a8f3c203 | 491 | __videobuf_dc_free(q->dev, mem); |
b2b476f5 PO |
492 | mem->vaddr = NULL; |
493 | } | |
2cc45cf2 MD |
494 | } |
495 | EXPORT_SYMBOL_GPL(videobuf_dma_contig_free); | |
496 | ||
497 | MODULE_DESCRIPTION("helper module to manage video4linux dma contig buffers"); | |
498 | MODULE_AUTHOR("Magnus Damm"); | |
499 | MODULE_LICENSE("GPL"); |