?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
sfc: Disable setting feature flags that are not implemented
[linux-2.6/x86.git] / drivers / media / video / videobuf-dma-sg.c
blob8359e6badd36789b9380c6a83ccca153e0d2cb71
1 /*
2 * helper functions for SG DMA video4linux capture buffers
3 *
4 * The functions expect the hardware being able to scatter gather
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 * Highly based on video-buf written originally by:
12 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
13 * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
14 * (c) 2006 Ted Walther and John Sokol
15 *
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2
19 */
20
21 #include <linux/init.h>
22 #include <linux/module.h>
23 #include <linux/moduleparam.h>
24 #include <linux/sched.h>
25 #include <linux/slab.h>
26 #include <linux/interrupt.h>
27
28 #include <linux/dma-mapping.h>
29 #include <linux/vmalloc.h>
30 #include <linux/pagemap.h>
31 #include <linux/scatterlist.h>
32 #include <asm/page.h>
33 #include <asm/pgtable.h>
34
35 #include <media/videobuf-dma-sg.h>
36
37 #define MAGIC_DMABUF 0x19721112
38 #define MAGIC_SG_MEM 0x17890714
39
40 #define MAGIC_CHECK(is, should) \
41 if (unlikely((is) != (should))) { \
42 printk(KERN_ERR "magic mismatch: %x (expected %x)\n", \
43 is, should); \
44 BUG(); \
45 }
46
47 static int debug;
48 module_param(debug, int, 0644);
49
50 MODULE_DESCRIPTION("helper module to manage video4linux dma sg buffers");
51 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
52 MODULE_LICENSE("GPL");
53
54 #define dprintk(level, fmt, arg...) \
55 if (debug >= level) \
56 printk(KERN_DEBUG "vbuf-sg: " fmt , ## arg)
57
58 /* --------------------------------------------------------------------- */
59
60 struct scatterlist *videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages)
61 {
62 struct scatterlist *sglist;
63 struct page *pg;
64 int i;
65
66 sglist = vmalloc(nr_pages * sizeof(*sglist));
67 if (NULL == sglist)
68 return NULL;
69 memset(sglist, 0, nr_pages * sizeof(*sglist));
70 sg_init_table(sglist, nr_pages);
71 for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
72 pg = vmalloc_to_page(virt);
73 if (NULL == pg)
74 goto err;
75 BUG_ON(PageHighMem(pg));
76 sg_set_page(&sglist[i], pg, PAGE_SIZE, 0);
77 }
78 return sglist;
79
80 err:
81 vfree(sglist);
82 return NULL;
83 }
84 EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
85
86 struct scatterlist *videobuf_pages_to_sg(struct page **pages, int nr_pages,
87 int offset)
88 {
89 struct scatterlist *sglist;
90 int i;
91
92 if (NULL == pages[0])
93 return NULL;
94 sglist = vmalloc(nr_pages * sizeof(*sglist));
95 if (NULL == sglist)
96 return NULL;
97 sg_init_table(sglist, nr_pages);
98
99 if (PageHighMem(pages[0]))
100 /* DMA to highmem pages might not work */
101 goto highmem;
102 sg_set_page(&sglist[0], pages[0], PAGE_SIZE - offset, offset);
103 for (i = 1; i < nr_pages; i++) {
104 if (NULL == pages[i])
105 goto nopage;
106 if (PageHighMem(pages[i]))
107 goto highmem;
108 sg_set_page(&sglist[i], pages[i], PAGE_SIZE, 0);
109 }
110 return sglist;
111
112 nopage:
113 dprintk(2, "sgl: oops - no page\n");
114 vfree(sglist);
115 return NULL;
116
117 highmem:
118 dprintk(2, "sgl: oops - highmem page\n");
119 vfree(sglist);
120 return NULL;
121 }
122
123 /* --------------------------------------------------------------------- */
124
125 struct videobuf_dmabuf *videobuf_to_dma(struct videobuf_buffer *buf)
126 {
127 struct videobuf_dma_sg_memory *mem = buf->priv;
128 BUG_ON(!mem);
129
130 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
131
132 return &mem->dma;
133 }
134 EXPORT_SYMBOL_GPL(videobuf_to_dma);
135
136 void videobuf_dma_init(struct videobuf_dmabuf *dma)
137 {
138 memset(dma, 0, sizeof(*dma));
139 dma->magic = MAGIC_DMABUF;
140 }
141 EXPORT_SYMBOL_GPL(videobuf_dma_init);
142
143 static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma,
144 int direction, unsigned long data, unsigned long size)
145 {
146 unsigned long first, last;
147 int err, rw = 0;
148
149 dma->direction = direction;
150 switch (dma->direction) {
151 case DMA_FROM_DEVICE:
152 rw = READ;
153 break;
154 case DMA_TO_DEVICE:
155 rw = WRITE;
156 break;
157 default:
158 BUG();
159 }
160
161 first = (data & PAGE_MASK) >> PAGE_SHIFT;
162 last = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
163 dma->offset = data & ~PAGE_MASK;
164 dma->nr_pages = last-first+1;
165 dma->pages = kmalloc(dma->nr_pages * sizeof(struct page *), GFP_KERNEL);
166 if (NULL == dma->pages)
167 return -ENOMEM;
168
169 dprintk(1, "init user [0x%lx+0x%lx => %d pages]\n",
170 data, size, dma->nr_pages);
171
172 err = get_user_pages(current, current->mm,
173 data & PAGE_MASK, dma->nr_pages,
174 rw == READ, 1, /* force */
175 dma->pages, NULL);
176
177 if (err != dma->nr_pages) {
178 dma->nr_pages = (err >= 0) ? err : 0;
179 dprintk(1, "get_user_pages: err=%d [%d]\n", err, dma->nr_pages);
180 return err < 0 ? err : -EINVAL;
181 }
182 return 0;
183 }
184
185 int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
186 unsigned long data, unsigned long size)
187 {
188 int ret;
189
190 down_read(&current->mm->mmap_sem);
191 ret = videobuf_dma_init_user_locked(dma, direction, data, size);
192 up_read(&current->mm->mmap_sem);
193
194 return ret;
195 }
196 EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
197
198 int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
199 int nr_pages)
200 {
201 dprintk(1, "init kernel [%d pages]\n", nr_pages);
202
203 dma->direction = direction;
204 dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
205 if (NULL == dma->vmalloc) {
206 dprintk(1, "vmalloc_32(%d pages) failed\n", nr_pages);
207 return -ENOMEM;
208 }
209
210 dprintk(1, "vmalloc is at addr 0x%08lx, size=%d\n",
211 (unsigned long)dma->vmalloc,
212 nr_pages << PAGE_SHIFT);
213
214 memset(dma->vmalloc, 0, nr_pages << PAGE_SHIFT);
215 dma->nr_pages = nr_pages;
216
217 return 0;
218 }
219 EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
220
221 int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
222 dma_addr_t addr, int nr_pages)
223 {
224 dprintk(1, "init overlay [%d pages @ bus 0x%lx]\n",
225 nr_pages, (unsigned long)addr);
226 dma->direction = direction;
227
228 if (0 == addr)
229 return -EINVAL;
230
231 dma->bus_addr = addr;
232 dma->nr_pages = nr_pages;
233
234 return 0;
235 }
236 EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
237
238 int videobuf_dma_map(struct videobuf_queue *q, struct videobuf_dmabuf *dma)
239 {
240 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
241 BUG_ON(0 == dma->nr_pages);
242
243 if (dma->pages) {
244 dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
245 dma->offset);
246 }
247 if (dma->vmalloc) {
248 dma->sglist = videobuf_vmalloc_to_sg(dma->vmalloc,
249 dma->nr_pages);
250 }
251 if (dma->bus_addr) {
252 dma->sglist = vmalloc(sizeof(*dma->sglist));
253 if (NULL != dma->sglist) {
254 dma->sglen = 1;
255 sg_dma_address(&dma->sglist[0]) = dma->bus_addr
256 & PAGE_MASK;
257 dma->sglist[0].offset = dma->bus_addr & ~PAGE_MASK;
258 sg_dma_len(&dma->sglist[0]) = dma->nr_pages * PAGE_SIZE;
259 }
260 }
261 if (NULL == dma->sglist) {
262 dprintk(1, "scatterlist is NULL\n");
263 return -ENOMEM;
264 }
265 if (!dma->bus_addr) {
266 dma->sglen = dma_map_sg(q->dev, dma->sglist,
267 dma->nr_pages, dma->direction);
268 if (0 == dma->sglen) {
269 printk(KERN_WARNING
270 "%s: videobuf_map_sg failed\n", __func__);
271 vfree(dma->sglist);
272 dma->sglist = NULL;
273 dma->sglen = 0;
274 return -ENOMEM;
275 }
276 }
277
278 return 0;
279 }
280 EXPORT_SYMBOL_GPL(videobuf_dma_map);
281
282 int videobuf_dma_unmap(struct videobuf_queue *q, struct videobuf_dmabuf *dma)
283 {
284 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
285
286 if (!dma->sglen)
287 return 0;
288
289 dma_unmap_sg(q->dev, dma->sglist, dma->sglen, dma->direction);
290
291 vfree(dma->sglist);
292 dma->sglist = NULL;
293 dma->sglen = 0;
294
295 return 0;
296 }
297 EXPORT_SYMBOL_GPL(videobuf_dma_unmap);
298
299 int videobuf_dma_free(struct videobuf_dmabuf *dma)
300 {
301 int i;
302 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
303 BUG_ON(dma->sglen);
304
305 if (dma->pages) {
306 for (i = 0; i < dma->nr_pages; i++)
307 page_cache_release(dma->pages[i]);
308 kfree(dma->pages);
309 dma->pages = NULL;
310 }
311
312 vfree(dma->vmalloc);
313 dma->vmalloc = NULL;
314
315 if (dma->bus_addr)
316 dma->bus_addr = 0;
317 dma->direction = DMA_NONE;
318
319 return 0;
320 }
321 EXPORT_SYMBOL_GPL(videobuf_dma_free);
322
323 /* --------------------------------------------------------------------- */
324
325 int videobuf_sg_dma_map(struct device *dev, struct videobuf_dmabuf *dma)
326 {
327 struct videobuf_queue q;
328
329 q.dev = dev;
330
331 return videobuf_dma_map(&q, dma);
332 }
333 EXPORT_SYMBOL_GPL(videobuf_sg_dma_map);
334
335 int videobuf_sg_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma)
336 {
337 struct videobuf_queue q;
338
339 q.dev = dev;
340
341 return videobuf_dma_unmap(&q, dma);
342 }
343 EXPORT_SYMBOL_GPL(videobuf_sg_dma_unmap);
344
345 /* --------------------------------------------------------------------- */
346
347 static void videobuf_vm_open(struct vm_area_struct *vma)
348 {
349 struct videobuf_mapping *map = vma->vm_private_data;
350
351 dprintk(2, "vm_open %p [count=%d,vma=%08lx-%08lx]\n", map,
352 map->count, vma->vm_start, vma->vm_end);
353
354 map->count++;
355 }
356
357 static void videobuf_vm_close(struct vm_area_struct *vma)
358 {
359 struct videobuf_mapping *map = vma->vm_private_data;
360 struct videobuf_queue *q = map->q;
361 struct videobuf_dma_sg_memory *mem;
362 int i;
363
364 dprintk(2, "vm_close %p [count=%d,vma=%08lx-%08lx]\n", map,
365 map->count, vma->vm_start, vma->vm_end);
366
367 map->count--;
368 if (0 == map->count) {
369 dprintk(1, "munmap %p q=%p\n", map, q);
370 mutex_lock(&q->vb_lock);
371 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
372 if (NULL == q->bufs[i])
373 continue;
374 mem = q->bufs[i]->priv;
375 if (!mem)
376 continue;
377
378 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
379
380 if (q->bufs[i]->map != map)
381 continue;
382 q->bufs[i]->map = NULL;
383 q->bufs[i]->baddr = 0;
384 q->ops->buf_release(q, q->bufs[i]);
385 }
386 mutex_unlock(&q->vb_lock);
387 kfree(map);
388 }
389 return;
390 }
391
392 /*
393 * Get a anonymous page for the mapping. Make sure we can DMA to that
394 * memory location with 32bit PCI devices (i.e. don't use highmem for
395 * now ...). Bounce buffers don't work very well for the data rates
396 * video capture has.
397 */
398 static int videobuf_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
399 {
400 struct page *page;
401
402 dprintk(3, "fault: fault @ %08lx [vma %08lx-%08lx]\n",
403 (unsigned long)vmf->virtual_address,
404 vma->vm_start, vma->vm_end);
405
406 page = alloc_page(GFP_USER | __GFP_DMA32);
407 if (!page)
408 return VM_FAULT_OOM;
409 clear_user_highpage(page, (unsigned long)vmf->virtual_address);
410 vmf->page = page;
411
412 return 0;
413 }
414
415 static const struct vm_operations_struct videobuf_vm_ops = {
416 .open = videobuf_vm_open,
417 .close = videobuf_vm_close,
418 .fault = videobuf_vm_fault,
419 };
420
421 /* ---------------------------------------------------------------------
422 * SG handlers for the generic methods
423 */
424
425 /* Allocated area consists on 3 parts:
426 struct video_buffer
427 struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
428 struct videobuf_dma_sg_memory
429 */
430
431 static struct videobuf_buffer *__videobuf_alloc(size_t size)
432 {
433 struct videobuf_dma_sg_memory *mem;
434 struct videobuf_buffer *vb;
435
436 vb = kzalloc(size + sizeof(*mem), GFP_KERNEL);
437 if (!vb)
438 return vb;
439
440 mem = vb->priv = ((char *)vb) + size;
441 mem->magic = MAGIC_SG_MEM;
442
443 videobuf_dma_init(&mem->dma);
444
445 dprintk(1, "%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
446 __func__, vb, (long)sizeof(*vb), (long)size - sizeof(*vb),
447 mem, (long)sizeof(*mem));
448
449 return vb;
450 }
451
452 static void *__videobuf_to_vaddr(struct videobuf_buffer *buf)
453 {
454 struct videobuf_dma_sg_memory *mem = buf->priv;
455 BUG_ON(!mem);
456
457 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
458
459 return mem->dma.vmalloc;
460 }
461
462 static int __videobuf_iolock(struct videobuf_queue *q,
463 struct videobuf_buffer *vb,
464 struct v4l2_framebuffer *fbuf)
465 {
466 int err, pages;
467 dma_addr_t bus;
468 struct videobuf_dma_sg_memory *mem = vb->priv;
469 BUG_ON(!mem);
470
471 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
472
473 switch (vb->memory) {
474 case V4L2_MEMORY_MMAP:
475 case V4L2_MEMORY_USERPTR:
476 if (0 == vb->baddr) {
477 /* no userspace addr -- kernel bounce buffer */
478 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
479 err = videobuf_dma_init_kernel(&mem->dma,
480 DMA_FROM_DEVICE,
481 pages);
482 if (0 != err)
483 return err;
484 } else if (vb->memory == V4L2_MEMORY_USERPTR) {
485 /* dma directly to userspace */
486 err = videobuf_dma_init_user(&mem->dma,
487 DMA_FROM_DEVICE,
488 vb->baddr, vb->bsize);
489 if (0 != err)
490 return err;
491 } else {
492 /* NOTE: HACK: videobuf_iolock on V4L2_MEMORY_MMAP
493 buffers can only be called from videobuf_qbuf
494 we take current->mm->mmap_sem there, to prevent
495 locking inversion, so don't take it here */
496
497 err = videobuf_dma_init_user_locked(&mem->dma,
498 DMA_FROM_DEVICE,
499 vb->baddr, vb->bsize);
500 if (0 != err)
501 return err;
502 }
503 break;
504 case V4L2_MEMORY_OVERLAY:
505 if (NULL == fbuf)
506 return -EINVAL;
507 /* FIXME: need sanity checks for vb->boff */
508 /*
509 * Using a double cast to avoid compiler warnings when
510 * building for PAE. Compiler doesn't like direct casting
511 * of a 32 bit ptr to 64 bit integer.
512 */
513 bus = (dma_addr_t)(unsigned long)fbuf->base + vb->boff;
514 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
515 err = videobuf_dma_init_overlay(&mem->dma, DMA_FROM_DEVICE,
516 bus, pages);
517 if (0 != err)
518 return err;
519 break;
520 default:
521 BUG();
522 }
523 err = videobuf_dma_map(q, &mem->dma);
524 if (0 != err)
525 return err;
526
527 return 0;
528 }
529
530 static int __videobuf_sync(struct videobuf_queue *q,
531 struct videobuf_buffer *buf)
532 {
533 struct videobuf_dma_sg_memory *mem = buf->priv;
534 BUG_ON(!mem || !mem->dma.sglen);
535
536 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
537 MAGIC_CHECK(mem->dma.magic, MAGIC_DMABUF);
538
539 dma_sync_sg_for_cpu(q->dev, mem->dma.sglist,
540 mem->dma.sglen, mem->dma.direction);
541
542 return 0;
543 }
544
545 static int __videobuf_mmap_mapper(struct videobuf_queue *q,
546 struct videobuf_buffer *buf,
547 struct vm_area_struct *vma)
548 {
549 struct videobuf_dma_sg_memory *mem = buf->priv;
550 struct videobuf_mapping *map;
551 unsigned int first, last, size = 0, i;
552 int retval;
553
554 retval = -EINVAL;
555
556 /* This function maintains backwards compatibility with V4L1 and will
557 * map more than one buffer if the vma length is equal to the combined
558 * size of multiple buffers than it will map them together. See
559 * VIDIOCGMBUF in the v4l spec
560 *
561 * TODO: Allow drivers to specify if they support this mode
562 */
563
564 BUG_ON(!mem);
565 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
566
567 /* look for first buffer to map */
568 for (first = 0; first < VIDEO_MAX_FRAME; first++) {
569 if (buf == q->bufs[first]) {
570 size = PAGE_ALIGN(q->bufs[first]->bsize);
571 break;
572 }
573 }
574
575 /* paranoia, should never happen since buf is always valid. */
576 if (!size) {
577 dprintk(1, "mmap app bug: offset invalid [offset=0x%lx]\n",
578 (vma->vm_pgoff << PAGE_SHIFT));
579 goto done;
580 }
581
582 last = first;
583 #ifdef CONFIG_VIDEO_V4L1_COMPAT
584 if (size != (vma->vm_end - vma->vm_start)) {
585 /* look for last buffer to map */
586 for (last = first + 1; last < VIDEO_MAX_FRAME; last++) {
587 if (NULL == q->bufs[last])
588 continue;
589 if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
590 continue;
591 if (q->bufs[last]->map) {
592 retval = -EBUSY;
593 goto done;
594 }
595 size += PAGE_ALIGN(q->bufs[last]->bsize);
596 if (size == (vma->vm_end - vma->vm_start))
597 break;
598 }
599 if (VIDEO_MAX_FRAME == last) {
600 dprintk(1, "mmap app bug: size invalid [size=0x%lx]\n",
601 (vma->vm_end - vma->vm_start));
602 goto done;
603 }
604 }
605 #endif
606
607 /* create mapping + update buffer list */
608 retval = -ENOMEM;
609 map = kmalloc(sizeof(struct videobuf_mapping), GFP_KERNEL);
610 if (NULL == map)
611 goto done;
612
613 size = 0;
614 for (i = first; i <= last; i++) {
615 if (NULL == q->bufs[i])
616 continue;
617 q->bufs[i]->map = map;
618 q->bufs[i]->baddr = vma->vm_start + size;
619 size += PAGE_ALIGN(q->bufs[i]->bsize);
620 }
621
622 map->count = 1;
623 map->start = vma->vm_start;
624 map->end = vma->vm_end;
625 map->q = q;
626 vma->vm_ops = &videobuf_vm_ops;
627 vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
628 vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
629 vma->vm_private_data = map;
630 dprintk(1, "mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
631 map, q, vma->vm_start, vma->vm_end, vma->vm_pgoff, first, last);
632 retval = 0;
633
634 done:
635 return retval;
636 }
637
638 static struct videobuf_qtype_ops sg_ops = {
639 .magic = MAGIC_QTYPE_OPS,
640
641 .alloc = __videobuf_alloc,
642 .iolock = __videobuf_iolock,
643 .sync = __videobuf_sync,
644 .mmap_mapper = __videobuf_mmap_mapper,
645 .vaddr = __videobuf_to_vaddr,
646 };
647
648 void *videobuf_sg_alloc(size_t size)
649 {
650 struct videobuf_queue q;
651
652 /* Required to make generic handler to call __videobuf_alloc */
653 q.int_ops = &sg_ops;
654
655 q.msize = size;
656
657 return videobuf_alloc(&q);
658 }
659 EXPORT_SYMBOL_GPL(videobuf_sg_alloc);
660
661 void videobuf_queue_sg_init(struct videobuf_queue *q,
662 const struct videobuf_queue_ops *ops,
663 struct device *dev,
664 spinlock_t *irqlock,
665 enum v4l2_buf_type type,
666 enum v4l2_field field,
667 unsigned int msize,
668 void *priv)
669 {
670 videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
671 priv, &sg_ops);
672 }
673 EXPORT_SYMBOL_GPL(videobuf_queue_sg_init);
674
x86 "subsystem" repository