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mm/gup: Switch all callers of get_user_pages() to not pass tsk/mm
[deliverable/linux.git] / drivers / media / v4l2-core / videobuf-dma-sg.c
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 /*
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(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(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
160 dma->direction = direction;
161 switch (dma->direction) {
162 case DMA_FROM_DEVICE:
163 rw = READ;
164 break;
165 case DMA_TO_DEVICE:
166 rw = WRITE;
167 break;
168 default:
169 BUG();
170 }
171
172 first = (data & PAGE_MASK) >> PAGE_SHIFT;
173 last = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
174 dma->offset = data & ~PAGE_MASK;
175 dma->size = size;
176 dma->nr_pages = last-first+1;
177 dma->pages = kmalloc(dma->nr_pages * sizeof(struct page *), GFP_KERNEL);
178 if (NULL == dma->pages)
179 return -ENOMEM;
180
181 dprintk(1, "init user [0x%lx+0x%lx => %d pages]\n",
182 data, size, dma->nr_pages);
183
184 err = get_user_pages(data & PAGE_MASK, dma->nr_pages,
185 rw == READ, 1, /* force */
186 dma->pages, NULL);
187
188 if (err != dma->nr_pages) {
189 dma->nr_pages = (err >= 0) ? err : 0;
190 dprintk(1, "get_user_pages: err=%d [%d]\n", err, dma->nr_pages);
191 return err < 0 ? err : -EINVAL;
192 }
193 return 0;
194 }
195
196 static int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
197 unsigned long data, unsigned long size)
198 {
199 int ret;
200
201 down_read(&current->mm->mmap_sem);
202 ret = videobuf_dma_init_user_locked(dma, direction, data, size);
203 up_read(&current->mm->mmap_sem);
204
205 return ret;
206 }
207
208 static int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
209 int nr_pages)
210 {
211 int i;
212
213 dprintk(1, "init kernel [%d pages]\n", nr_pages);
214
215 dma->direction = direction;
216 dma->vaddr_pages = kcalloc(nr_pages, sizeof(*dma->vaddr_pages),
217 GFP_KERNEL);
218 if (!dma->vaddr_pages)
219 return -ENOMEM;
220
221 dma->dma_addr = kcalloc(nr_pages, sizeof(*dma->dma_addr), GFP_KERNEL);
222 if (!dma->dma_addr) {
223 kfree(dma->vaddr_pages);
224 return -ENOMEM;
225 }
226 for (i = 0; i < nr_pages; i++) {
227 void *addr;
228
229 addr = dma_alloc_coherent(dma->dev, PAGE_SIZE,
230 &(dma->dma_addr[i]), GFP_KERNEL);
231 if (addr == NULL)
232 goto out_free_pages;
233
234 dma->vaddr_pages[i] = virt_to_page(addr);
235 }
236 dma->vaddr = vmap(dma->vaddr_pages, nr_pages, VM_MAP | VM_IOREMAP,
237 PAGE_KERNEL);
238 if (NULL == dma->vaddr) {
239 dprintk(1, "vmalloc_32(%d pages) failed\n", nr_pages);
240 goto out_free_pages;
241 }
242
243 dprintk(1, "vmalloc is at addr 0x%08lx, size=%d\n",
244 (unsigned long)dma->vaddr,
245 nr_pages << PAGE_SHIFT);
246
247 memset(dma->vaddr, 0, nr_pages << PAGE_SHIFT);
248 dma->nr_pages = nr_pages;
249
250 return 0;
251 out_free_pages:
252 while (i > 0) {
253 void *addr;
254
255 i--;
256 addr = page_address(dma->vaddr_pages[i]);
257 dma_free_coherent(dma->dev, PAGE_SIZE, addr, dma->dma_addr[i]);
258 }
259 kfree(dma->dma_addr);
260 dma->dma_addr = NULL;
261 kfree(dma->vaddr_pages);
262 dma->vaddr_pages = NULL;
263
264 return -ENOMEM;
265
266 }
267
268 static int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
269 dma_addr_t addr, int nr_pages)
270 {
271 dprintk(1, "init overlay [%d pages @ bus 0x%lx]\n",
272 nr_pages, (unsigned long)addr);
273 dma->direction = direction;
274
275 if (0 == addr)
276 return -EINVAL;
277
278 dma->bus_addr = addr;
279 dma->nr_pages = nr_pages;
280
281 return 0;
282 }
283
284 static int videobuf_dma_map(struct device *dev, struct videobuf_dmabuf *dma)
285 {
286 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
287 BUG_ON(0 == dma->nr_pages);
288
289 if (dma->pages) {
290 dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
291 dma->offset, dma->size);
292 }
293 if (dma->vaddr) {
294 dma->sglist = videobuf_vmalloc_to_sg(dma->vaddr,
295 dma->nr_pages);
296 }
297 if (dma->bus_addr) {
298 dma->sglist = vmalloc(sizeof(*dma->sglist));
299 if (NULL != dma->sglist) {
300 dma->sglen = 1;
301 sg_dma_address(&dma->sglist[0]) = dma->bus_addr
302 & PAGE_MASK;
303 dma->sglist[0].offset = dma->bus_addr & ~PAGE_MASK;
304 sg_dma_len(&dma->sglist[0]) = dma->nr_pages * PAGE_SIZE;
305 }
306 }
307 if (NULL == dma->sglist) {
308 dprintk(1, "scatterlist is NULL\n");
309 return -ENOMEM;
310 }
311 if (!dma->bus_addr) {
312 dma->sglen = dma_map_sg(dev, dma->sglist,
313 dma->nr_pages, dma->direction);
314 if (0 == dma->sglen) {
315 printk(KERN_WARNING
316 "%s: videobuf_map_sg failed\n", __func__);
317 vfree(dma->sglist);
318 dma->sglist = NULL;
319 dma->sglen = 0;
320 return -ENOMEM;
321 }
322 }
323
324 return 0;
325 }
326
327 int videobuf_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma)
328 {
329 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
330
331 if (!dma->sglen)
332 return 0;
333
334 dma_unmap_sg(dev, dma->sglist, dma->sglen, dma->direction);
335
336 vfree(dma->sglist);
337 dma->sglist = NULL;
338 dma->sglen = 0;
339
340 return 0;
341 }
342 EXPORT_SYMBOL_GPL(videobuf_dma_unmap);
343
344 int videobuf_dma_free(struct videobuf_dmabuf *dma)
345 {
346 int i;
347 MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
348 BUG_ON(dma->sglen);
349
350 if (dma->pages) {
351 for (i = 0; i < dma->nr_pages; i++)
352 page_cache_release(dma->pages[i]);
353 kfree(dma->pages);
354 dma->pages = NULL;
355 }
356
357 if (dma->dma_addr) {
358 for (i = 0; i < dma->nr_pages; i++) {
359 void *addr;
360
361 addr = page_address(dma->vaddr_pages[i]);
362 dma_free_coherent(dma->dev, PAGE_SIZE, addr,
363 dma->dma_addr[i]);
364 }
365 kfree(dma->dma_addr);
366 dma->dma_addr = NULL;
367 kfree(dma->vaddr_pages);
368 dma->vaddr_pages = NULL;
369 vunmap(dma->vaddr);
370 dma->vaddr = NULL;
371 }
372
373 if (dma->bus_addr)
374 dma->bus_addr = 0;
375 dma->direction = DMA_NONE;
376
377 return 0;
378 }
379 EXPORT_SYMBOL_GPL(videobuf_dma_free);
380
381 /* --------------------------------------------------------------------- */
382
383 static void videobuf_vm_open(struct vm_area_struct *vma)
384 {
385 struct videobuf_mapping *map = vma->vm_private_data;
386
387 dprintk(2, "vm_open %p [count=%d,vma=%08lx-%08lx]\n", map,
388 map->count, vma->vm_start, vma->vm_end);
389
390 map->count++;
391 }
392
393 static void videobuf_vm_close(struct vm_area_struct *vma)
394 {
395 struct videobuf_mapping *map = vma->vm_private_data;
396 struct videobuf_queue *q = map->q;
397 struct videobuf_dma_sg_memory *mem;
398 int i;
399
400 dprintk(2, "vm_close %p [count=%d,vma=%08lx-%08lx]\n", map,
401 map->count, vma->vm_start, vma->vm_end);
402
403 map->count--;
404 if (0 == map->count) {
405 dprintk(1, "munmap %p q=%p\n", map, q);
406 videobuf_queue_lock(q);
407 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
408 if (NULL == q->bufs[i])
409 continue;
410 mem = q->bufs[i]->priv;
411 if (!mem)
412 continue;
413
414 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
415
416 if (q->bufs[i]->map != map)
417 continue;
418 q->bufs[i]->map = NULL;
419 q->bufs[i]->baddr = 0;
420 q->ops->buf_release(q, q->bufs[i]);
421 }
422 videobuf_queue_unlock(q);
423 kfree(map);
424 }
425 return;
426 }
427
428 /*
429 * Get a anonymous page for the mapping. Make sure we can DMA to that
430 * memory location with 32bit PCI devices (i.e. don't use highmem for
431 * now ...). Bounce buffers don't work very well for the data rates
432 * video capture has.
433 */
434 static int videobuf_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
435 {
436 struct page *page;
437
438 dprintk(3, "fault: fault @ %08lx [vma %08lx-%08lx]\n",
439 (unsigned long)vmf->virtual_address,
440 vma->vm_start, vma->vm_end);
441
442 page = alloc_page(GFP_USER | __GFP_DMA32);
443 if (!page)
444 return VM_FAULT_OOM;
445 clear_user_highpage(page, (unsigned long)vmf->virtual_address);
446 vmf->page = page;
447
448 return 0;
449 }
450
451 static const struct vm_operations_struct videobuf_vm_ops = {
452 .open = videobuf_vm_open,
453 .close = videobuf_vm_close,
454 .fault = videobuf_vm_fault,
455 };
456
457 /* ---------------------------------------------------------------------
458 * SG handlers for the generic methods
459 */
460
461 /* Allocated area consists on 3 parts:
462 struct video_buffer
463 struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
464 struct videobuf_dma_sg_memory
465 */
466
467 static struct videobuf_buffer *__videobuf_alloc_vb(size_t size)
468 {
469 struct videobuf_dma_sg_memory *mem;
470 struct videobuf_buffer *vb;
471
472 vb = kzalloc(size + sizeof(*mem), GFP_KERNEL);
473 if (!vb)
474 return vb;
475
476 mem = vb->priv = ((char *)vb) + size;
477 mem->magic = MAGIC_SG_MEM;
478
479 videobuf_dma_init(&mem->dma);
480
481 dprintk(1, "%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
482 __func__, vb, (long)sizeof(*vb), (long)size - sizeof(*vb),
483 mem, (long)sizeof(*mem));
484
485 return vb;
486 }
487
488 static void *__videobuf_to_vaddr(struct videobuf_buffer *buf)
489 {
490 struct videobuf_dma_sg_memory *mem = buf->priv;
491 BUG_ON(!mem);
492
493 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
494
495 return mem->dma.vaddr;
496 }
497
498 static int __videobuf_iolock(struct videobuf_queue *q,
499 struct videobuf_buffer *vb,
500 struct v4l2_framebuffer *fbuf)
501 {
502 int err, pages;
503 dma_addr_t bus;
504 struct videobuf_dma_sg_memory *mem = vb->priv;
505 BUG_ON(!mem);
506
507 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
508
509 if (!mem->dma.dev)
510 mem->dma.dev = q->dev;
511 else
512 WARN_ON(mem->dma.dev != q->dev);
513
514 switch (vb->memory) {
515 case V4L2_MEMORY_MMAP:
516 case V4L2_MEMORY_USERPTR:
517 if (0 == vb->baddr) {
518 /* no userspace addr -- kernel bounce buffer */
519 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
520 err = videobuf_dma_init_kernel(&mem->dma,
521 DMA_FROM_DEVICE,
522 pages);
523 if (0 != err)
524 return err;
525 } else if (vb->memory == V4L2_MEMORY_USERPTR) {
526 /* dma directly to userspace */
527 err = videobuf_dma_init_user(&mem->dma,
528 DMA_FROM_DEVICE,
529 vb->baddr, vb->bsize);
530 if (0 != err)
531 return err;
532 } else {
533 /* NOTE: HACK: videobuf_iolock on V4L2_MEMORY_MMAP
534 buffers can only be called from videobuf_qbuf
535 we take current->mm->mmap_sem there, to prevent
536 locking inversion, so don't take it here */
537
538 err = videobuf_dma_init_user_locked(&mem->dma,
539 DMA_FROM_DEVICE,
540 vb->baddr, vb->bsize);
541 if (0 != err)
542 return err;
543 }
544 break;
545 case V4L2_MEMORY_OVERLAY:
546 if (NULL == fbuf)
547 return -EINVAL;
548 /* FIXME: need sanity checks for vb->boff */
549 /*
550 * Using a double cast to avoid compiler warnings when
551 * building for PAE. Compiler doesn't like direct casting
552 * of a 32 bit ptr to 64 bit integer.
553 */
554 bus = (dma_addr_t)(unsigned long)fbuf->base + vb->boff;
555 pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
556 err = videobuf_dma_init_overlay(&mem->dma, DMA_FROM_DEVICE,
557 bus, pages);
558 if (0 != err)
559 return err;
560 break;
561 default:
562 BUG();
563 }
564 err = videobuf_dma_map(q->dev, &mem->dma);
565 if (0 != err)
566 return err;
567
568 return 0;
569 }
570
571 static int __videobuf_sync(struct videobuf_queue *q,
572 struct videobuf_buffer *buf)
573 {
574 struct videobuf_dma_sg_memory *mem = buf->priv;
575 BUG_ON(!mem || !mem->dma.sglen);
576
577 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
578 MAGIC_CHECK(mem->dma.magic, MAGIC_DMABUF);
579
580 dma_sync_sg_for_cpu(q->dev, mem->dma.sglist,
581 mem->dma.sglen, mem->dma.direction);
582
583 return 0;
584 }
585
586 static int __videobuf_mmap_mapper(struct videobuf_queue *q,
587 struct videobuf_buffer *buf,
588 struct vm_area_struct *vma)
589 {
590 struct videobuf_dma_sg_memory *mem = buf->priv;
591 struct videobuf_mapping *map;
592 unsigned int first, last, size = 0, i;
593 int retval;
594
595 retval = -EINVAL;
596
597 BUG_ON(!mem);
598 MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
599
600 /* look for first buffer to map */
601 for (first = 0; first < VIDEO_MAX_FRAME; first++) {
602 if (buf == q->bufs[first]) {
603 size = PAGE_ALIGN(q->bufs[first]->bsize);
604 break;
605 }
606 }
607
608 /* paranoia, should never happen since buf is always valid. */
609 if (!size) {
610 dprintk(1, "mmap app bug: offset invalid [offset=0x%lx]\n",
611 (vma->vm_pgoff << PAGE_SHIFT));
612 goto done;
613 }
614
615 last = first;
616
617 /* create mapping + update buffer list */
618 retval = -ENOMEM;
619 map = kmalloc(sizeof(struct videobuf_mapping), GFP_KERNEL);
620 if (NULL == map)
621 goto done;
622
623 size = 0;
624 for (i = first; i <= last; i++) {
625 if (NULL == q->bufs[i])
626 continue;
627 q->bufs[i]->map = map;
628 q->bufs[i]->baddr = vma->vm_start + size;
629 size += PAGE_ALIGN(q->bufs[i]->bsize);
630 }
631
632 map->count = 1;
633 map->q = q;
634 vma->vm_ops = &videobuf_vm_ops;
635 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
636 vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
637 vma->vm_private_data = map;
638 dprintk(1, "mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
639 map, q, vma->vm_start, vma->vm_end, vma->vm_pgoff, first, last);
640 retval = 0;
641
642 done:
643 return retval;
644 }
645
646 static struct videobuf_qtype_ops sg_ops = {
647 .magic = MAGIC_QTYPE_OPS,
648
649 .alloc_vb = __videobuf_alloc_vb,
650 .iolock = __videobuf_iolock,
651 .sync = __videobuf_sync,
652 .mmap_mapper = __videobuf_mmap_mapper,
653 .vaddr = __videobuf_to_vaddr,
654 };
655
656 void *videobuf_sg_alloc(size_t size)
657 {
658 struct videobuf_queue q;
659
660 /* Required to make generic handler to call __videobuf_alloc */
661 q.int_ops = &sg_ops;
662
663 q.msize = size;
664
665 return videobuf_alloc_vb(&q);
666 }
667 EXPORT_SYMBOL_GPL(videobuf_sg_alloc);
668
669 void videobuf_queue_sg_init(struct videobuf_queue *q,
670 const struct videobuf_queue_ops *ops,
671 struct device *dev,
672 spinlock_t *irqlock,
673 enum v4l2_buf_type type,
674 enum v4l2_field field,
675 unsigned int msize,
676 void *priv,
677 struct mutex *ext_lock)
678 {
679 videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
680 priv, &sg_ops, ext_lock);
681 }
682 EXPORT_SYMBOL_GPL(videobuf_queue_sg_init);
683
Linux kernel - Deliverables
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