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perf tools: Don't clone maps from parent when synthesizing forks
[linux/fpc-iii.git] / drivers / media / v4l2-core / videobuf-dma-sg.c
blob08929c087e270397f8d013102e6961f19e2f09b4
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@kernel.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@kernel.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/mm.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@kernel.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 /*
61 * Return a scatterlist for some page-aligned vmalloc()'ed memory
62 * block (NULL on errors). Memory for the scatterlist is allocated
63 * using kmalloc. The caller must free the memory.
64 */
65 static 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(array_size(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
85 err:
86 vfree(sglist);
87 return NULL;
88 }
89
90 /*
91 * Return a scatterlist for a an array of userpages (NULL on errors).
92 * Memory for the scatterlist is allocated using kmalloc. The caller
93 * must free the memory.
94 */
95 static 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(array_size(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 /* DMA to highmem pages might not work */
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
124 nopage:
125 dprintk(2, "sgl: oops - no page\n");
126 vfree(sglist);
127 return NULL;
128
129 highmem:
130 dprintk(2, "sgl: oops - highmem page\n");
131 vfree(sglist);
132 return NULL;
133 }
134
135 /* --------------------------------------------------------------------- */
136
137 struct 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 }
146 EXPORT_SYMBOL_GPL(videobuf_to_dma);
147
148 static void videobuf_dma_init(struct videobuf_dmabuf *dma)
149 {
150 memset(dma, 0, sizeof(*dma));
151 dma->magic = MAGIC_DMABUF;
152 }
153
154 static 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_array(dma->nr_pages, sizeof(struct page *),
179 GFP_KERNEL);
180 if (NULL == dma->pages)
181 return -ENOMEM;
182
183 if (rw == READ)
184 flags |= FOLL_WRITE;
185
186 dprintk(1, "init user [0x%lx+0x%lx => %d pages]\n",
187 data, size, dma->nr_pages);
188
189 err = get_user_pages_longterm(data & PAGE_MASK, dma->nr_pages,
190 flags, dma->pages, NULL);
191
192 if (err != dma->nr_pages) {
193 dma->nr_pages = (err >= 0) ? err : 0;
194 dprintk(1, "get_user_pages_longterm: err=%d [%d]\n", err,
195 dma->nr_pages);
196 return err < 0 ? err : -EINVAL;
197 }
198 return 0;
199 }
200
201 static int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
202 unsigned long data, unsigned long size)
203 {
204 int ret;
205
206 down_read(&current->mm->mmap_sem);
207 ret = videobuf_dma_init_user_locked(dma, direction, data, size);
208 up_read(&current->mm->mmap_sem);
209
210 return ret;
211 }
212
213 static int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
214 int nr_pages)
215 {
216 int i;
217
218 dprintk(1, "init kernel [%d pages]\n", nr_pages);
219
220 dma->direction = direction;
221 dma->vaddr_pages = kcalloc(nr_pages, sizeof(*dma->vaddr_pages),
222 GFP_KERNEL);
223 if (!dma->vaddr_pages)
224 return -ENOMEM;
225
226 dma->dma_addr = kcalloc(nr_pages, sizeof(*dma->dma_addr), GFP_KERNEL);
227 if (!dma->dma_addr) {
228 kfree(dma->vaddr_pages);
229 return -ENOMEM;
230 }
231 for (i = 0; i < nr_pages; i++) {
232 void *addr;
233
234 addr = dma_alloc_coherent(dma->dev, PAGE_SIZE,
235 &(dma->dma_addr[i]), GFP_KERNEL);
236 if (addr == NULL)
237 goto out_free_pages;
238
239 dma->vaddr_pages[i] = virt_to_page(addr);
240 }
241 dma->vaddr = vmap(dma->vaddr_pages, nr_pages, VM_MAP | VM_IOREMAP,
242 PAGE_KERNEL);
243 if (NULL == dma->vaddr) {
244 dprintk(1, "vmalloc_32(%d pages) failed\n", nr_pages);
245 goto out_free_pages;
246 }
247
248 dprintk(1, "vmalloc is at addr %p, size=%d\n",
249 dma->vaddr, nr_pages << PAGE_SHIFT);
250
251 memset(dma->vaddr, 0, nr_pages << PAGE_SHIFT);
252 dma->nr_pages = nr_pages;
253
254 return 0;
255 out_free_pages:
256 while (i > 0) {
257 void *addr;
258
259 i--;
260 addr = page_address(dma->vaddr_pages[i]);
261 dma_free_coherent(dma->dev, PAGE_SIZE, addr, dma->dma_addr[i]);
262 }
263 kfree(dma->dma_addr);
264 dma->dma_addr = NULL;
265 kfree(dma->vaddr_pages);
266 dma->vaddr_pages = NULL;
267
268 return -ENOMEM;
269
270 }
271
272 static int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
273 dma_addr_t addr, int nr_pages)
274 {
275 dprintk(1, "init overlay [%d pages @ bus 0x%lx]\n",
276 nr_pages, (unsigned long)addr);
277 dma->direction = direction;
278
279 if (0 == addr)
280 return -EINVAL;
281
282 dma->bus_addr = addr;
283 dma->nr_pages = nr_pages;
284
285 return 0;
286 }
287
288 static int videobuf_dma_map(struct device *dev, struct videobuf_dmabuf *dma)
289 {
290 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
291 BUG_ON(0 == dma->nr_pages);
292
293 if (dma->pages) {
294 dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
295 dma->offset, dma->size);
296 }
297 if (dma->vaddr) {
298 dma->sglist = videobuf_vmalloc_to_sg(dma->vaddr,
299 dma->nr_pages);
300 }
301 if (dma->bus_addr) {
302 dma->sglist = vmalloc(sizeof(*dma->sglist));
303 if (NULL != dma->sglist) {
304 dma->sglen = 1;
305 sg_dma_address(&dma->sglist[0]) = dma->bus_addr
306 & PAGE_MASK;
307 dma->sglist[0].offset = dma->bus_addr & ~PAGE_MASK;
308 sg_dma_len(&dma->sglist[0]) = dma->nr_pages * PAGE_SIZE;
309 }
310 }
311 if (NULL == dma->sglist) {
312 dprintk(1, "scatterlist is NULL\n");
313 return -ENOMEM;
314 }
315 if (!dma->bus_addr) {
316 dma->sglen = dma_map_sg(dev, dma->sglist,
317 dma->nr_pages, dma->direction);
318 if (0 == dma->sglen) {
319 printk(KERN_WARNING
320 "%s: videobuf_map_sg failed\n", __func__);
321 vfree(dma->sglist);
322 dma->sglist = NULL;
323 dma->sglen = 0;
324 return -ENOMEM;
325 }
326 }
327
328 return 0;
329 }
330
331 int videobuf_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma)
332 {
333 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
334
335 if (!dma->sglen)
336 return 0;
337
338 dma_unmap_sg(dev, dma->sglist, dma->nr_pages, dma->direction);
339
340 vfree(dma->sglist);
341 dma->sglist = NULL;
342 dma->sglen = 0;
343
344 return 0;
345 }
346 EXPORT_SYMBOL_GPL(videobuf_dma_unmap);
347
348 int videobuf_dma_free(struct videobuf_dmabuf *dma)
349 {
350 int i;
351 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
352 BUG_ON(dma->sglen);
353
354 if (dma->pages) {
355 for (i = 0; i < dma->nr_pages; i++)
356 put_page(dma->pages[i]);
357 kfree(dma->pages);
358 dma->pages = NULL;
359 }
360
361 if (dma->dma_addr) {
362 for (i = 0; i < dma->nr_pages; i++) {
363 void *addr;
364
365 addr = page_address(dma->vaddr_pages[i]);
366 dma_free_coherent(dma->dev, PAGE_SIZE, addr,
367 dma->dma_addr[i]);
368 }
369 kfree(dma->dma_addr);
370 dma->dma_addr = NULL;
371 kfree(dma->vaddr_pages);
372 dma->vaddr_pages = NULL;
373 vunmap(dma->vaddr);
374 dma->vaddr = NULL;
375 }
376
377 if (dma->bus_addr)
378 dma->bus_addr = 0;
379 dma->direction = DMA_NONE;
380
381 return 0;
382 }
383 EXPORT_SYMBOL_GPL(videobuf_dma_free);
384
385 /* --------------------------------------------------------------------- */
386
387 static void videobuf_vm_open(struct vm_area_struct *vma)
388 {
389 struct videobuf_mapping *map = vma->vm_private_data;
390
391 dprintk(2, "vm_open %p [count=%d,vma=%08lx-%08lx]\n", map,
392 map->count, vma->vm_start, vma->vm_end);
393
394 map->count++;
395 }
396
397 static void videobuf_vm_close(struct vm_area_struct *vma)
398 {
399 struct videobuf_mapping *map = vma->vm_private_data;
400 struct videobuf_queue *q = map->q;
401 struct videobuf_dma_sg_memory *mem;
402 int i;
403
404 dprintk(2, "vm_close %p [count=%d,vma=%08lx-%08lx]\n", map,
405 map->count, vma->vm_start, vma->vm_end);
406
407 map->count--;
408 if (0 == map->count) {
409 dprintk(1, "munmap %p q=%p\n", map, q);
410 videobuf_queue_lock(q);
411 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
412 if (NULL == q->bufs[i])
413 continue;
414 mem = q->bufs[i]->priv;
415 if (!mem)
416 continue;
417
418 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
419
420 if (q->bufs[i]->map != map)
421 continue;
422 q->bufs[i]->map = NULL;
423 q->bufs[i]->baddr = 0;
424 q->ops->buf_release(q, q->bufs[i]);
425 }
426 videobuf_queue_unlock(q);
427 kfree(map);
428 }
429 return;
430 }
431
432 /*
433 * Get a anonymous page for the mapping. Make sure we can DMA to that
434 * memory location with 32bit PCI devices (i.e. don't use highmem for
435 * now ...). Bounce buffers don't work very well for the data rates
436 * video capture has.
437 */
438 static vm_fault_t videobuf_vm_fault(struct vm_fault *vmf)
439 {
440 struct vm_area_struct *vma = vmf->vma;
441 struct page *page;
442
443 dprintk(3, "fault: fault @ %08lx [vma %08lx-%08lx]\n",
444 vmf->address, vma->vm_start, vma->vm_end);
445
446 page = alloc_page(GFP_USER | __GFP_DMA32);
447 if (!page)
448 return VM_FAULT_OOM;
449 clear_user_highpage(page, vmf->address);
450 vmf->page = page;
451
452 return 0;
453 }
454
455 static const struct vm_operations_struct videobuf_vm_ops = {
456 .open = videobuf_vm_open,
457 .close = videobuf_vm_close,
458 .fault = videobuf_vm_fault,
459 };
460
461 /* ---------------------------------------------------------------------
462 * SG handlers for the generic methods
463 */
464
465 /* Allocated area consists on 3 parts:
466 struct video_buffer
467 struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
468 struct videobuf_dma_sg_memory
469 */
470
471 static struct videobuf_buffer *__videobuf_alloc_vb(size_t size)
472 {
473 struct videobuf_dma_sg_memory *mem;
474 struct videobuf_buffer *vb;
475
476 vb = kzalloc(size + sizeof(*mem), GFP_KERNEL);
477 if (!vb)
478 return vb;
479
480 mem = vb->priv = ((char *)vb) + size;
481 mem->magic = MAGIC_SG_MEM;
482
483 videobuf_dma_init(&mem->dma);
484
485 dprintk(1, "%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
486 __func__, vb, (long)sizeof(*vb), (long)size - sizeof(*vb),
487 mem, (long)sizeof(*mem));
488
489 return vb;
490 }
491
492 static void *__videobuf_to_vaddr(struct videobuf_buffer *buf)
493 {
494 struct videobuf_dma_sg_memory *mem = buf->priv;
495 BUG_ON(!mem);
496
497 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
498
499 return mem->dma.vaddr;
500 }
501
502 static int __videobuf_iolock(struct videobuf_queue *q,
503 struct videobuf_buffer *vb,
504 struct v4l2_framebuffer *fbuf)
505 {
506 int err, pages;
507 dma_addr_t bus;
508 struct videobuf_dma_sg_memory *mem = vb->priv;
509 BUG_ON(!mem);
510
511 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
512
513 if (!mem->dma.dev)
514 mem->dma.dev = q->dev;
515 else
516 WARN_ON(mem->dma.dev != q->dev);
517
518 switch (vb->memory) {
519 case V4L2_MEMORY_MMAP:
520 case V4L2_MEMORY_USERPTR:
521 if (0 == vb->baddr) {
522 /* no userspace addr -- kernel bounce buffer */
523 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
524 err = videobuf_dma_init_kernel(&mem->dma,
525 DMA_FROM_DEVICE,
526 pages);
527 if (0 != err)
528 return err;
529 } else if (vb->memory == V4L2_MEMORY_USERPTR) {
530 /* dma directly to userspace */
531 err = videobuf_dma_init_user(&mem->dma,
532 DMA_FROM_DEVICE,
533 vb->baddr, vb->bsize);
534 if (0 != err)
535 return err;
536 } else {
537 /* NOTE: HACK: videobuf_iolock on V4L2_MEMORY_MMAP
538 buffers can only be called from videobuf_qbuf
539 we take current->mm->mmap_sem there, to prevent
540 locking inversion, so don't take it here */
541
542 err = videobuf_dma_init_user_locked(&mem->dma,
543 DMA_FROM_DEVICE,
544 vb->baddr, vb->bsize);
545 if (0 != err)
546 return err;
547 }
548 break;
549 case V4L2_MEMORY_OVERLAY:
550 if (NULL == fbuf)
551 return -EINVAL;
552 /* FIXME: need sanity checks for vb->boff */
553 /*
554 * Using a double cast to avoid compiler warnings when
555 * building for PAE. Compiler doesn't like direct casting
556 * of a 32 bit ptr to 64 bit integer.
557 */
558 bus = (dma_addr_t)(unsigned long)fbuf->base + vb->boff;
559 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
560 err = videobuf_dma_init_overlay(&mem->dma, DMA_FROM_DEVICE,
561 bus, pages);
562 if (0 != err)
563 return err;
564 break;
565 default:
566 BUG();
567 }
568 err = videobuf_dma_map(q->dev, &mem->dma);
569 if (0 != err)
570 return err;
571
572 return 0;
573 }
574
575 static int __videobuf_sync(struct videobuf_queue *q,
576 struct videobuf_buffer *buf)
577 {
578 struct videobuf_dma_sg_memory *mem = buf->priv;
579 BUG_ON(!mem || !mem->dma.sglen);
580
581 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
582 MAGIC_CHECK(mem->dma.magic, MAGIC_DMABUF);
583
584 dma_sync_sg_for_cpu(q->dev, mem->dma.sglist,
585 mem->dma.nr_pages, mem->dma.direction);
586
587 return 0;
588 }
589
590 static int __videobuf_mmap_mapper(struct videobuf_queue *q,
591 struct videobuf_buffer *buf,
592 struct vm_area_struct *vma)
593 {
594 struct videobuf_dma_sg_memory *mem = buf->priv;
595 struct videobuf_mapping *map;
596 unsigned int first, last, size = 0, i;
597 int retval;
598
599 retval = -EINVAL;
600
601 BUG_ON(!mem);
602 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
603
604 /* look for first buffer to map */
605 for (first = 0; first < VIDEO_MAX_FRAME; first++) {
606 if (buf == q->bufs[first]) {
607 size = PAGE_ALIGN(q->bufs[first]->bsize);
608 break;
609 }
610 }
611
612 /* paranoia, should never happen since buf is always valid. */
613 if (!size) {
614 dprintk(1, "mmap app bug: offset invalid [offset=0x%lx]\n",
615 (vma->vm_pgoff << PAGE_SHIFT));
616 goto done;
617 }
618
619 last = first;
620
621 /* create mapping + update buffer list */
622 retval = -ENOMEM;
623 map = kmalloc(sizeof(struct videobuf_mapping), GFP_KERNEL);
624 if (NULL == map)
625 goto done;
626
627 size = 0;
628 for (i = first; i <= last; i++) {
629 if (NULL == q->bufs[i])
630 continue;
631 q->bufs[i]->map = map;
632 q->bufs[i]->baddr = vma->vm_start + size;
633 size += PAGE_ALIGN(q->bufs[i]->bsize);
634 }
635
636 map->count = 1;
637 map->q = q;
638 vma->vm_ops = &videobuf_vm_ops;
639 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
640 vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
641 vma->vm_private_data = map;
642 dprintk(1, "mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
643 map, q, vma->vm_start, vma->vm_end, vma->vm_pgoff, first, last);
644 retval = 0;
645
646 done:
647 return retval;
648 }
649
650 static struct videobuf_qtype_ops sg_ops = {
651 .magic = MAGIC_QTYPE_OPS,
652
653 .alloc_vb = __videobuf_alloc_vb,
654 .iolock = __videobuf_iolock,
655 .sync = __videobuf_sync,
656 .mmap_mapper = __videobuf_mmap_mapper,
657 .vaddr = __videobuf_to_vaddr,
658 };
659
660 void *videobuf_sg_alloc(size_t size)
661 {
662 struct videobuf_queue q;
663
664 /* Required to make generic handler to call __videobuf_alloc */
665 q.int_ops = &sg_ops;
666
667 q.msize = size;
668
669 return videobuf_alloc_vb(&q);
670 }
671 EXPORT_SYMBOL_GPL(videobuf_sg_alloc);
672
673 void videobuf_queue_sg_init(struct videobuf_queue *q,
674 const struct videobuf_queue_ops *ops,
675 struct device *dev,
676 spinlock_t *irqlock,
677 enum v4l2_buf_type type,
678 enum v4l2_field field,
679 unsigned int msize,
680 void *priv,
681 struct mutex *ext_lock)
682 {
683 videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
684 priv, &sg_ops, ext_lock);
685 }
686 EXPORT_SYMBOL_GPL(videobuf_queue_sg_init);
687
Linux with added FPC-III support