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