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21#include <linux/init.h>
22#include <linux/module.h>
23#include <linux/moduleparam.h>
24#include <linux/slab.h>
25#include <linux/interrupt.h>
26
27#include <linux/dma-mapping.h>
28#include <linux/vmalloc.h>
29#include <linux/pagemap.h>
30#include <linux/scatterlist.h>
31#include <asm/page.h>
32#include <asm/pgtable.h>
33
34#include <media/videobuf-dma-sg.h>
35
36#define MAGIC_DMABUF 0x19721112
37#define MAGIC_SG_MEM 0x17890714
38
39#define MAGIC_CHECK(is,should) if (unlikely((is) != (should))) \
40 { printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); }
41
42static int debug;
43module_param(debug, int, 0644);
44
45MODULE_DESCRIPTION("helper module to manage video4linux dma sg buffers");
46MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
47MODULE_LICENSE("GPL");
48
49#define dprintk(level, fmt, arg...) if (debug >= level) \
50 printk(KERN_DEBUG "vbuf-sg: " fmt , ## arg)
51
52
53
54struct scatterlist*
55videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages)
56{
57 struct scatterlist *sglist;
58 struct page *pg;
59 int i;
60
61 sglist = kcalloc(nr_pages, sizeof(struct scatterlist), GFP_KERNEL);
62 if (NULL == sglist)
63 return NULL;
64 sg_init_table(sglist, nr_pages);
65 for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
66 pg = vmalloc_to_page(virt);
67 if (NULL == pg)
68 goto err;
69 BUG_ON(PageHighMem(pg));
70 sg_set_page(&sglist[i], pg, PAGE_SIZE, 0);
71 }
72 return sglist;
73
74 err:
75 kfree(sglist);
76 return NULL;
77}
78
79struct scatterlist*
80videobuf_pages_to_sg(struct page **pages, int nr_pages, int offset)
81{
82 struct scatterlist *sglist;
83 int i;
84
85 if (NULL == pages[0])
86 return NULL;
87 sglist = kmalloc(nr_pages * sizeof(*sglist), GFP_KERNEL);
88 if (NULL == sglist)
89 return NULL;
90 sg_init_table(sglist, nr_pages);
91
92 if (PageHighMem(pages[0]))
93
94 goto highmem;
95 sg_set_page(&sglist[0], pages[0], PAGE_SIZE - offset, offset);
96 for (i = 1; i < nr_pages; i++) {
97 if (NULL == pages[i])
98 goto nopage;
99 if (PageHighMem(pages[i]))
100 goto highmem;
101 sg_set_page(&sglist[i], pages[i], PAGE_SIZE, 0);
102 }
103 return sglist;
104
105 nopage:
106 dprintk(2,"sgl: oops - no page\n");
107 kfree(sglist);
108 return NULL;
109
110 highmem:
111 dprintk(2,"sgl: oops - highmem page\n");
112 kfree(sglist);
113 return NULL;
114}
115
116
117
118struct videobuf_dmabuf *videobuf_to_dma (struct videobuf_buffer *buf)
119{
120 struct videobuf_dma_sg_memory *mem = buf->priv;
121 BUG_ON(!mem);
122
123 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
124
125 return &mem->dma;
126}
127
128void videobuf_dma_init(struct videobuf_dmabuf *dma)
129{
130 memset(dma,0,sizeof(*dma));
131 dma->magic = MAGIC_DMABUF;
132}
133
134static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma,
135 int direction, unsigned long data, unsigned long size)
136{
137 unsigned long first,last;
138 int err, rw = 0;
139
140 dma->direction = direction;
141 switch (dma->direction) {
142 case DMA_FROM_DEVICE:
143 rw = READ;
144 break;
145 case DMA_TO_DEVICE:
146 rw = WRITE;
147 break;
148 default:
149 BUG();
150 }
151
152 first = (data & PAGE_MASK) >> PAGE_SHIFT;
153 last = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
154 dma->offset = data & ~PAGE_MASK;
155 dma->nr_pages = last-first+1;
156 dma->pages = kmalloc(dma->nr_pages * sizeof(struct page*),
157 GFP_KERNEL);
158 if (NULL == dma->pages)
159 return -ENOMEM;
160 dprintk(1,"init user [0x%lx+0x%lx => %d pages]\n",
161 data,size,dma->nr_pages);
162
163 err = get_user_pages(current,current->mm,
164 data & PAGE_MASK, dma->nr_pages,
165 rw == READ, 1,
166 dma->pages, NULL);
167
168 if (err != dma->nr_pages) {
169 dma->nr_pages = (err >= 0) ? err : 0;
170 dprintk(1,"get_user_pages: err=%d [%d]\n",err,dma->nr_pages);
171 return err < 0 ? err : -EINVAL;
172 }
173 return 0;
174}
175
176int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
177 unsigned long data, unsigned long size)
178{
179 int ret;
180 down_read(¤t->mm->mmap_sem);
181 ret = videobuf_dma_init_user_locked(dma, direction, data, size);
182 up_read(¤t->mm->mmap_sem);
183
184 return ret;
185}
186
187int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
188 int nr_pages)
189{
190 dprintk(1,"init kernel [%d pages]\n",nr_pages);
191 dma->direction = direction;
192 dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
193 if (NULL == dma->vmalloc) {
194 dprintk(1,"vmalloc_32(%d pages) failed\n",nr_pages);
195 return -ENOMEM;
196 }
197 dprintk(1,"vmalloc is at addr 0x%08lx, size=%d\n",
198 (unsigned long)dma->vmalloc,
199 nr_pages << PAGE_SHIFT);
200 memset(dma->vmalloc,0,nr_pages << PAGE_SHIFT);
201 dma->nr_pages = nr_pages;
202 return 0;
203}
204
205int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
206 dma_addr_t addr, int nr_pages)
207{
208 dprintk(1,"init overlay [%d pages @ bus 0x%lx]\n",
209 nr_pages,(unsigned long)addr);
210 dma->direction = direction;
211 if (0 == addr)
212 return -EINVAL;
213
214 dma->bus_addr = addr;
215 dma->nr_pages = nr_pages;
216 return 0;
217}
218
219int videobuf_dma_map(struct videobuf_queue* q, struct videobuf_dmabuf *dma)
220{
221 MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
222 BUG_ON(0 == dma->nr_pages);
223
224 if (dma->pages) {
225 dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
226 dma->offset);
227 }
228 if (dma->vmalloc) {
229 dma->sglist = videobuf_vmalloc_to_sg
230 (dma->vmalloc,dma->nr_pages);
231 }
232 if (dma->bus_addr) {
233 dma->sglist = kmalloc(sizeof(struct scatterlist), GFP_KERNEL);
234 if (NULL != dma->sglist) {
235 dma->sglen = 1;
236 sg_dma_address(&dma->sglist[0]) = dma->bus_addr & PAGE_MASK;
237 dma->sglist[0].offset = dma->bus_addr & ~PAGE_MASK;
238 sg_dma_len(&dma->sglist[0]) = dma->nr_pages * PAGE_SIZE;
239 }
240 }
241 if (NULL == dma->sglist) {
242 dprintk(1,"scatterlist is NULL\n");
243 return -ENOMEM;
244 }
245 if (!dma->bus_addr) {
246 dma->sglen = dma_map_sg(q->dev, dma->sglist,
247 dma->nr_pages, dma->direction);
248 if (0 == dma->sglen) {
249 printk(KERN_WARNING
250 "%s: videobuf_map_sg failed\n",__func__);
251 kfree(dma->sglist);
252 dma->sglist = NULL;
253 dma->sglen = 0;
254 return -EIO;
255 }
256 }
257 return 0;
258}
259
260int videobuf_dma_sync(struct videobuf_queue *q, struct videobuf_dmabuf *dma)
261{
262 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
263 BUG_ON(!dma->sglen);
264
265 dma_sync_sg_for_cpu(q->dev, dma->sglist, dma->nr_pages, dma->direction);
266 return 0;
267}
268
269int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
270{
271 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
272 if (!dma->sglen)
273 return 0;
274
275 dma_unmap_sg(q->dev, dma->sglist, dma->nr_pages, dma->direction);
276
277 kfree(dma->sglist);
278 dma->sglist = NULL;
279 dma->sglen = 0;
280 return 0;
281}
282
283int videobuf_dma_free(struct videobuf_dmabuf *dma)
284{
285 MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
286 BUG_ON(dma->sglen);
287
288 if (dma->pages) {
289 int i;
290 for (i=0; i < dma->nr_pages; i++)
291 page_cache_release(dma->pages[i]);
292 kfree(dma->pages);
293 dma->pages = NULL;
294 }
295
296 vfree(dma->vmalloc);
297 dma->vmalloc = NULL;
298
299 if (dma->bus_addr) {
300 dma->bus_addr = 0;
301 }
302 dma->direction = DMA_NONE;
303 return 0;
304}
305
306
307
308int videobuf_sg_dma_map(struct device *dev, struct videobuf_dmabuf *dma)
309{
310 struct videobuf_queue q;
311
312 q.dev = dev;
313
314 return videobuf_dma_map(&q, dma);
315}
316
317int videobuf_sg_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma)
318{
319 struct videobuf_queue q;
320
321 q.dev = dev;
322
323 return videobuf_dma_unmap(&q, dma);
324}
325
326
327
328static void
329videobuf_vm_open(struct vm_area_struct *vma)
330{
331 struct videobuf_mapping *map = vma->vm_private_data;
332
333 dprintk(2,"vm_open %p [count=%d,vma=%08lx-%08lx]\n",map,
334 map->count,vma->vm_start,vma->vm_end);
335 map->count++;
336}
337
338static void
339videobuf_vm_close(struct vm_area_struct *vma)
340{
341 struct videobuf_mapping *map = vma->vm_private_data;
342 struct videobuf_queue *q = map->q;
343 struct videobuf_dma_sg_memory *mem;
344 int i;
345
346 dprintk(2,"vm_close %p [count=%d,vma=%08lx-%08lx]\n",map,
347 map->count,vma->vm_start,vma->vm_end);
348
349 map->count--;
350 if (0 == map->count) {
351 dprintk(1,"munmap %p q=%p\n",map,q);
352 mutex_lock(&q->vb_lock);
353 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
354 if (NULL == q->bufs[i])
355 continue;
356 mem=q->bufs[i]->priv;
357
358 if (!mem)
359 continue;
360
361 MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
362
363 if (q->bufs[i]->map != map)
364 continue;
365 q->bufs[i]->map = NULL;
366 q->bufs[i]->baddr = 0;
367 q->ops->buf_release(q,q->bufs[i]);
368 }
369 mutex_unlock(&q->vb_lock);
370 kfree(map);
371 }
372 return;
373}
374
375
376
377
378
379
380
381static int
382videobuf_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
383{
384 struct page *page;
385
386 dprintk(3,"fault: fault @ %08lx [vma %08lx-%08lx]\n",
387 (unsigned long)vmf->virtual_address,vma->vm_start,vma->vm_end);
388 page = alloc_page(GFP_USER | __GFP_DMA32);
389 if (!page)
390 return VM_FAULT_OOM;
391 clear_user_page(page_address(page), (unsigned long)vmf->virtual_address,
392 page);
393 vmf->page = page;
394 return 0;
395}
396
397static struct vm_operations_struct videobuf_vm_ops =
398{
399 .open = videobuf_vm_open,
400 .close = videobuf_vm_close,
401 .fault = videobuf_vm_fault,
402};
403
404
405
406
407
408
409
410
411
412
413
414static void *__videobuf_alloc(size_t size)
415{
416 struct videobuf_dma_sg_memory *mem;
417 struct videobuf_buffer *vb;
418
419 vb = kzalloc(size+sizeof(*mem),GFP_KERNEL);
420
421 mem = vb->priv = ((char *)vb)+size;
422 mem->magic=MAGIC_SG_MEM;
423
424 videobuf_dma_init(&mem->dma);
425
426 dprintk(1,"%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
427 __func__,vb,(long)sizeof(*vb),(long)size-sizeof(*vb),
428 mem,(long)sizeof(*mem));
429
430 return vb;
431}
432
433static void *__videobuf_to_vmalloc (struct videobuf_buffer *buf)
434{
435 struct videobuf_dma_sg_memory *mem = buf->priv;
436 BUG_ON(!mem);
437
438 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
439
440 return mem->dma.vmalloc;
441}
442
443static int __videobuf_iolock (struct videobuf_queue* q,
444 struct videobuf_buffer *vb,
445 struct v4l2_framebuffer *fbuf)
446{
447 int err,pages;
448 dma_addr_t bus;
449 struct videobuf_dma_sg_memory *mem = vb->priv;
450 BUG_ON(!mem);
451
452 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
453
454 switch (vb->memory) {
455 case V4L2_MEMORY_MMAP:
456 case V4L2_MEMORY_USERPTR:
457 if (0 == vb->baddr) {
458
459 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
460 err = videobuf_dma_init_kernel( &mem->dma,
461 DMA_FROM_DEVICE,
462 pages );
463 if (0 != err)
464 return err;
465 } else if (vb->memory == V4L2_MEMORY_USERPTR) {
466
467 err = videobuf_dma_init_user( &mem->dma,
468 DMA_FROM_DEVICE,
469 vb->baddr,vb->bsize );
470 if (0 != err)
471 return err;
472 } else {
473
474
475
476
477
478 err = videobuf_dma_init_user_locked(&mem->dma,
479 DMA_FROM_DEVICE,
480 vb->baddr, vb->bsize);
481 if (0 != err)
482 return err;
483 }
484 break;
485 case V4L2_MEMORY_OVERLAY:
486 if (NULL == fbuf)
487 return -EINVAL;
488
489
490
491
492
493
494 bus = (dma_addr_t)(unsigned long)fbuf->base + vb->boff;
495 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
496 err = videobuf_dma_init_overlay(&mem->dma, DMA_FROM_DEVICE,
497 bus, pages);
498 if (0 != err)
499 return err;
500 break;
501 default:
502 BUG();
503 }
504 err = videobuf_dma_map(q, &mem->dma);
505 if (0 != err)
506 return err;
507
508 return 0;
509}
510
511static int __videobuf_sync(struct videobuf_queue *q,
512 struct videobuf_buffer *buf)
513{
514 struct videobuf_dma_sg_memory *mem = buf->priv;
515 BUG_ON(!mem);
516 MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
517
518 return videobuf_dma_sync(q,&mem->dma);
519}
520
521static int __videobuf_mmap_free(struct videobuf_queue *q)
522{
523 int i;
524
525 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
526 if (q->bufs[i]) {
527 if (q->bufs[i]->map)
528 return -EBUSY;
529 }
530 }
531
532 return 0;
533}
534
535static int __videobuf_mmap_mapper(struct videobuf_queue *q,
536 struct vm_area_struct *vma)
537{
538 struct videobuf_dma_sg_memory *mem;
539 struct videobuf_mapping *map;
540 unsigned int first,last,size,i;
541 int retval;
542
543 retval = -EINVAL;
544 if (!(vma->vm_flags & VM_WRITE)) {
545 dprintk(1,"mmap app bug: PROT_WRITE please\n");
546 goto done;
547 }
548 if (!(vma->vm_flags & VM_SHARED)) {
549 dprintk(1,"mmap app bug: MAP_SHARED please\n");
550 goto done;
551 }
552
553
554
555
556
557
558
559
560
561
562 for (first = 0; first < VIDEO_MAX_FRAME; first++) {
563 if (NULL == q->bufs[first])
564 continue;
565 mem=q->bufs[first]->priv;
566 BUG_ON(!mem);
567 MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
568
569 if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
570 continue;
571 if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
572 break;
573 }
574 if (VIDEO_MAX_FRAME == first) {
575 dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
576 (vma->vm_pgoff << PAGE_SHIFT));
577 goto done;
578 }
579
580
581 for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
582 if (NULL == q->bufs[last])
583 continue;
584 if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
585 continue;
586 if (q->bufs[last]->map) {
587 retval = -EBUSY;
588 goto done;
589 }
590 size += q->bufs[last]->bsize;
591 if (size == (vma->vm_end - vma->vm_start))
592 break;
593 }
594 if (VIDEO_MAX_FRAME == last) {
595 dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n",
596 (vma->vm_end - vma->vm_start));
597 goto done;
598 }
599
600
601 retval = -ENOMEM;
602 map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
603 if (NULL == map)
604 goto done;
605
606 size = 0;
607 for (i = first; i <= last; i++) {
608 if (NULL == q->bufs[i])
609 continue;
610 q->bufs[i]->map = map;
611 q->bufs[i]->baddr = vma->vm_start + size;
612 size += q->bufs[i]->bsize;
613 }
614
615 map->count = 1;
616 map->start = vma->vm_start;
617 map->end = vma->vm_end;
618 map->q = q;
619 vma->vm_ops = &videobuf_vm_ops;
620 vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
621 vma->vm_flags &= ~VM_IO;
622 vma->vm_private_data = map;
623 dprintk(1,"mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
624 map,q,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
625 retval = 0;
626
627 done:
628 return retval;
629}
630
631static int __videobuf_copy_to_user ( struct videobuf_queue *q,
632 char __user *data, size_t count,
633 int nonblocking )
634{
635 struct videobuf_dma_sg_memory *mem = q->read_buf->priv;
636 BUG_ON(!mem);
637 MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
638
639
640 if (count > q->read_buf->size - q->read_off)
641 count = q->read_buf->size - q->read_off;
642
643 if (copy_to_user(data, mem->dma.vmalloc+q->read_off, count))
644 return -EFAULT;
645
646 return count;
647}
648
649static int __videobuf_copy_stream ( struct videobuf_queue *q,
650 char __user *data, size_t count, size_t pos,
651 int vbihack, int nonblocking )
652{
653 unsigned int *fc;
654 struct videobuf_dma_sg_memory *mem = q->read_buf->priv;
655 BUG_ON(!mem);
656 MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
657
658 if (vbihack) {
659
660
661
662
663 fc = (unsigned int*)mem->dma.vmalloc;
664 fc += (q->read_buf->size>>2) -1;
665 *fc = q->read_buf->field_count >> 1;
666 dprintk(1,"vbihack: %d\n",*fc);
667 }
668
669
670 count = __videobuf_copy_to_user (q,data,count,nonblocking);
671
672 if ( (count==-EFAULT) && (0 == pos) )
673 return -EFAULT;
674
675 return count;
676}
677
678static struct videobuf_qtype_ops sg_ops = {
679 .magic = MAGIC_QTYPE_OPS,
680
681 .alloc = __videobuf_alloc,
682 .iolock = __videobuf_iolock,
683 .sync = __videobuf_sync,
684 .mmap_free = __videobuf_mmap_free,
685 .mmap_mapper = __videobuf_mmap_mapper,
686 .video_copy_to_user = __videobuf_copy_to_user,
687 .copy_stream = __videobuf_copy_stream,
688 .vmalloc = __videobuf_to_vmalloc,
689};
690
691void *videobuf_sg_alloc(size_t size)
692{
693 struct videobuf_queue q;
694
695
696 q.int_ops = &sg_ops;
697
698 q.msize = size;
699
700 return videobuf_alloc(&q);
701}
702
703void videobuf_queue_sg_init(struct videobuf_queue* q,
704 struct videobuf_queue_ops *ops,
705 struct device *dev,
706 spinlock_t *irqlock,
707 enum v4l2_buf_type type,
708 enum v4l2_field field,
709 unsigned int msize,
710 void *priv)
711{
712 videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
713 priv, &sg_ops);
714}
715
716
717
718EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
719
720EXPORT_SYMBOL_GPL(videobuf_to_dma);
721EXPORT_SYMBOL_GPL(videobuf_dma_init);
722EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
723EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
724EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
725EXPORT_SYMBOL_GPL(videobuf_dma_map);
726EXPORT_SYMBOL_GPL(videobuf_dma_sync);
727EXPORT_SYMBOL_GPL(videobuf_dma_unmap);
728EXPORT_SYMBOL_GPL(videobuf_dma_free);
729
730EXPORT_SYMBOL_GPL(videobuf_sg_dma_map);
731EXPORT_SYMBOL_GPL(videobuf_sg_dma_unmap);
732EXPORT_SYMBOL_GPL(videobuf_sg_alloc);
733
734EXPORT_SYMBOL_GPL(videobuf_queue_sg_init);
735
736
737
738
739
740
741
