drivers/media/common/videobuf2/videobuf2-dma-sg.c

   1 /*
   2  * videobuf2-dma-sg.c - dma scatter/gather memory allocator for videobuf2
   3  *
   4  * Copyright (C) 2010 Samsung Electronics
   5  *
   6  * Author: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/mm.h>
  15 #include <linux/refcount.h>
  16 #include <linux/scatterlist.h>
  17 #include <linux/sched.h>
  18 #include <linux/slab.h>
  19 #include <linux/vmalloc.h>
  20
  21 #include <media/videobuf2-v4l2.h>
  22 #include <media/videobuf2-memops.h>
  23 #include <media/videobuf2-dma-sg.h>
  24
  25 static int debug;
  26 module_param(debug, int, 0644);
  27
  28 #define dprintk(level, fmt, arg...)                                     \
  29         do {                                                            \
  30                 if (debug >= level)                                     \
  31                         printk(KERN_DEBUG "vb2-dma-sg: " fmt, ## arg);  \
  32         } while (0)
  33
  34 struct vb2_dma_sg_buf {
  35         struct device                   *dev;
  36         void                            *vaddr;
  37         struct page                     **pages;
  38         struct frame_vector             *vec;
  39         int                             offset;
  40         enum dma_data_direction         dma_dir;
  41         struct sg_table                 sg_table;
  42         /*
  43          * This will point to sg_table when used with the MMAP or USERPTR
  44          * memory model, and to the dma_buf sglist when used with the
  45          * DMABUF memory model.
  46          */
  47         struct sg_table                 *dma_sgt;
  48         size_t                          size;
  49         unsigned int                    num_pages;
  50         refcount_t                      refcount;
  51         struct vb2_vmarea_handler       handler;
  52
  53         struct dma_buf_attachment       *db_attach;
  54
  55         struct vb2_buffer               *vb;
  56 };
  57
  58 static void vb2_dma_sg_put(void *buf_priv);
  59
  60 static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf,
  61                 gfp_t gfp_flags)
  62 {
  63         unsigned int last_page = 0;
  64         unsigned long size = buf->size;
  65
  66         while (size > 0) {
  67                 struct page *pages;
  68                 int order;
  69                 int i;
  70
  71                 order = get_order(size);
  72                 /* Don't over allocate*/
  73                 if ((PAGE_SIZE << order) > size)
  74                         order--;
  75
  76                 pages = NULL;
  77                 while (!pages) {
  78                         pages = alloc_pages(GFP_KERNEL | __GFP_ZERO |
  79                                         __GFP_NOWARN | gfp_flags, order);
  80                         if (pages)
  81                                 break;
  82
  83                         if (order == 0) {
  84                                 while (last_page--)
  85                                         __free_page(buf->pages[last_page]);
  86                                 return -ENOMEM;
  87                         }
  88                         order--;
  89                 }
  90
  91                 split_page(pages, order);
  92                 for (i = 0; i < (1 << order); i++)
  93                         buf->pages[last_page++] = &pages[i];
  94
  95                 size -= PAGE_SIZE << order;
  96         }
  97
  98         return 0;
  99 }
 100
 101 static void *vb2_dma_sg_alloc(struct vb2_buffer *vb, struct device *dev,
 102                               unsigned long size)
 103 {
 104         struct vb2_dma_sg_buf *buf;
 105         struct sg_table *sgt;
 106         int ret;
 107         int num_pages;
 108
 109         if (WARN_ON(!dev) || WARN_ON(!size))
 110                 return ERR_PTR(-EINVAL);
 111
 112         buf = kzalloc(sizeof *buf, GFP_KERNEL);
 113         if (!buf)
 114                 return ERR_PTR(-ENOMEM);
 115
 116         buf->vaddr = NULL;
 117         buf->dma_dir = vb->vb2_queue->dma_dir;
 118         buf->offset = 0;
 119         buf->size = size;
 120         /* size is already page aligned */
 121         buf->num_pages = size >> PAGE_SHIFT;
 122         buf->dma_sgt = &buf->sg_table;
 123
 124         /*
 125          * NOTE: dma-sg allocates memory using the page allocator directly, so
 126          * there is no memory consistency guarantee, hence dma-sg ignores DMA
 127          * attributes passed from the upper layer.
 128          */
 129         buf->pages = kvmalloc_array(buf->num_pages, sizeof(struct page *),
 130                                     GFP_KERNEL | __GFP_ZERO);
 131         if (!buf->pages)
 132                 goto fail_pages_array_alloc;
 133
 134         ret = vb2_dma_sg_alloc_compacted(buf, vb->vb2_queue->gfp_flags);
 135         if (ret)
 136                 goto fail_pages_alloc;
 137
 138         ret = sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
 139                         buf->num_pages, 0, size, GFP_KERNEL);
 140         if (ret)
 141                 goto fail_table_alloc;
 142
 143         /* Prevent the device from being released while the buffer is used */
 144         buf->dev = get_device(dev);
 145
 146         sgt = &buf->sg_table;
 147         /*
 148          * No need to sync to the device, this will happen later when the
 149          * prepare() memop is called.
 150          */
 151         if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
 152                             DMA_ATTR_SKIP_CPU_SYNC))
 153                 goto fail_map;
 154
 155         buf->handler.refcount = &buf->refcount;
 156         buf->handler.put = vb2_dma_sg_put;
 157         buf->handler.arg = buf;
 158         buf->vb = vb;
 159
 160         refcount_set(&buf->refcount, 1);
 161
 162         dprintk(1, "%s: Allocated buffer of %d pages\n",
 163                 __func__, buf->num_pages);
 164         return buf;
 165
 166 fail_map:
 167         put_device(buf->dev);
 168         sg_free_table(buf->dma_sgt);
 169 fail_table_alloc:
 170         num_pages = buf->num_pages;
 171         while (num_pages--)
 172                 __free_page(buf->pages[num_pages]);
 173 fail_pages_alloc:
 174         kvfree(buf->pages);
 175 fail_pages_array_alloc:
 176         kfree(buf);
 177         return ERR_PTR(-ENOMEM);
 178 }
 179
 180 static void vb2_dma_sg_put(void *buf_priv)
 181 {
 182         struct vb2_dma_sg_buf *buf = buf_priv;
 183         struct sg_table *sgt = &buf->sg_table;
 184         int i = buf->num_pages;
 185
 186         if (refcount_dec_and_test(&buf->refcount)) {
 187                 dprintk(1, "%s: Freeing buffer of %d pages\n", __func__,
 188                         buf->num_pages);
 189                 dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir,
 190                                   DMA_ATTR_SKIP_CPU_SYNC);
 191                 if (buf->vaddr)
 192                         vm_unmap_ram(buf->vaddr, buf->num_pages);
 193                 sg_free_table(buf->dma_sgt);
 194                 while (--i >= 0)
 195                         __free_page(buf->pages[i]);
 196                 kvfree(buf->pages);
 197                 put_device(buf->dev);
 198                 kfree(buf);
 199         }
 200 }
 201
 202 static void vb2_dma_sg_prepare(void *buf_priv)
 203 {
 204         struct vb2_dma_sg_buf *buf = buf_priv;
 205         struct sg_table *sgt = buf->dma_sgt;
 206
 207         if (buf->vb->skip_cache_sync_on_prepare)
 208                 return;
 209
 210         dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir);
 211 }
 212
 213 static void vb2_dma_sg_finish(void *buf_priv)
 214 {
 215         struct vb2_dma_sg_buf *buf = buf_priv;
 216         struct sg_table *sgt = buf->dma_sgt;
 217
 218         if (buf->vb->skip_cache_sync_on_finish)
 219                 return;
 220
 221         dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir);
 222 }
 223
 224 static void *vb2_dma_sg_get_userptr(struct vb2_buffer *vb, struct device *dev,
 225                                     unsigned long vaddr, unsigned long size)
 226 {
 227         struct vb2_dma_sg_buf *buf;
 228         struct sg_table *sgt;
 229         struct frame_vector *vec;
 230
 231         if (WARN_ON(!dev))
 232                 return ERR_PTR(-EINVAL);
 233
 234         buf = kzalloc(sizeof *buf, GFP_KERNEL);
 235         if (!buf)
 236                 return ERR_PTR(-ENOMEM);
 237
 238         buf->vaddr = NULL;
 239         buf->dev = dev;
 240         buf->dma_dir = vb->vb2_queue->dma_dir;
 241         buf->offset = vaddr & ~PAGE_MASK;
 242         buf->size = size;
 243         buf->dma_sgt = &buf->sg_table;
 244         buf->vb = vb;
 245         vec = vb2_create_framevec(vaddr, size);
 246         if (IS_ERR(vec))
 247                 goto userptr_fail_pfnvec;
 248         buf->vec = vec;
 249
 250         buf->pages = frame_vector_pages(vec);
 251         if (IS_ERR(buf->pages))
 252                 goto userptr_fail_sgtable;
 253         buf->num_pages = frame_vector_count(vec);
 254
 255         if (sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
 256                         buf->num_pages, buf->offset, size, 0))
 257                 goto userptr_fail_sgtable;
 258
 259         sgt = &buf->sg_table;
 260         /*
 261          * No need to sync to the device, this will happen later when the
 262          * prepare() memop is called.
 263          */
 264         if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
 265                             DMA_ATTR_SKIP_CPU_SYNC))
 266                 goto userptr_fail_map;
 267
 268         return buf;
 269
 270 userptr_fail_map:
 271         sg_free_table(&buf->sg_table);
 272 userptr_fail_sgtable:
 273         vb2_destroy_framevec(vec);
 274 userptr_fail_pfnvec:
 275         kfree(buf);
 276         return ERR_PTR(-ENOMEM);
 277 }
 278
 279 /*
 280  * @put_userptr: inform the allocator that a USERPTR buffer will no longer
 281  *               be used
 282  */
 283 static void vb2_dma_sg_put_userptr(void *buf_priv)
 284 {
 285         struct vb2_dma_sg_buf *buf = buf_priv;
 286         struct sg_table *sgt = &buf->sg_table;
 287         int i = buf->num_pages;
 288
 289         dprintk(1, "%s: Releasing userspace buffer of %d pages\n",
 290                __func__, buf->num_pages);
 291         dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
 292         if (buf->vaddr)
 293                 vm_unmap_ram(buf->vaddr, buf->num_pages);
 294         sg_free_table(buf->dma_sgt);
 295         if (buf->dma_dir == DMA_FROM_DEVICE ||
 296             buf->dma_dir == DMA_BIDIRECTIONAL)
 297                 while (--i >= 0)
 298                         set_page_dirty_lock(buf->pages[i]);
 299         vb2_destroy_framevec(buf->vec);
 300         kfree(buf);
 301 }
 302
 303 static void *vb2_dma_sg_vaddr(struct vb2_buffer *vb, void *buf_priv)
 304 {
 305         struct vb2_dma_sg_buf *buf = buf_priv;
 306         struct dma_buf_map map;
 307         int ret;
 308
 309         BUG_ON(!buf);
 310
 311         if (!buf->vaddr) {
 312                 if (buf->db_attach) {
 313                         ret = dma_buf_vmap(buf->db_attach->dmabuf, &map);
 314                         buf->vaddr = ret ? NULL : map.vaddr;
 315                 } else {
 316                         buf->vaddr = vm_map_ram(buf->pages, buf->num_pages, -1);
 317                 }
 318         }
 319
 320         /* add offset in case userptr is not page-aligned */
 321         return buf->vaddr ? buf->vaddr + buf->offset : NULL;
 322 }
 323
 324 static unsigned int vb2_dma_sg_num_users(void *buf_priv)
 325 {
 326         struct vb2_dma_sg_buf *buf = buf_priv;
 327
 328         return refcount_read(&buf->refcount);
 329 }
 330
 331 static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma)
 332 {
 333         struct vb2_dma_sg_buf *buf = buf_priv;
 334         int err;
 335
 336         if (!buf) {
 337                 printk(KERN_ERR "No memory to map\n");
 338                 return -EINVAL;
 339         }
 340
 341         err = vm_map_pages(vma, buf->pages, buf->num_pages);
 342         if (err) {
 343                 printk(KERN_ERR "Remapping memory, error: %d\n", err);
 344                 return err;
 345         }
 346
 347         /*
 348          * Use common vm_area operations to track buffer refcount.
 349          */
 350         vma->vm_private_data    = &buf->handler;
 351         vma->vm_ops             = &vb2_common_vm_ops;
 352
 353         vma->vm_ops->open(vma);
 354
 355         return 0;
 356 }
 357
 358 /*********************************************/
 359 /*         DMABUF ops for exporters          */
 360 /*********************************************/
 361
 362 struct vb2_dma_sg_attachment {
 363         struct sg_table sgt;
 364         enum dma_data_direction dma_dir;
 365 };
 366
 367 static int vb2_dma_sg_dmabuf_ops_attach(struct dma_buf *dbuf,
 368         struct dma_buf_attachment *dbuf_attach)
 369 {
 370         struct vb2_dma_sg_attachment *attach;
 371         unsigned int i;
 372         struct scatterlist *rd, *wr;
 373         struct sg_table *sgt;
 374         struct vb2_dma_sg_buf *buf = dbuf->priv;
 375         int ret;
 376
 377         attach = kzalloc(sizeof(*attach), GFP_KERNEL);
 378         if (!attach)
 379                 return -ENOMEM;
 380
 381         sgt = &attach->sgt;
 382         /* Copy the buf->base_sgt scatter list to the attachment, as we can't
 383          * map the same scatter list to multiple attachments at the same time.
 384          */
 385         ret = sg_alloc_table(sgt, buf->dma_sgt->orig_nents, GFP_KERNEL);
 386         if (ret) {
 387                 kfree(attach);
 388                 return -ENOMEM;
 389         }
 390
 391         rd = buf->dma_sgt->sgl;
 392         wr = sgt->sgl;
 393         for (i = 0; i < sgt->orig_nents; ++i) {
 394                 sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
 395                 rd = sg_next(rd);
 396                 wr = sg_next(wr);
 397         }
 398
 399         attach->dma_dir = DMA_NONE;
 400         dbuf_attach->priv = attach;
 401
 402         return 0;
 403 }
 404
 405 static void vb2_dma_sg_dmabuf_ops_detach(struct dma_buf *dbuf,
 406         struct dma_buf_attachment *db_attach)
 407 {
 408         struct vb2_dma_sg_attachment *attach = db_attach->priv;
 409         struct sg_table *sgt;
 410
 411         if (!attach)
 412                 return;
 413
 414         sgt = &attach->sgt;
 415
 416         /* release the scatterlist cache */
 417         if (attach->dma_dir != DMA_NONE)
 418                 dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, 0);
 419         sg_free_table(sgt);
 420         kfree(attach);
 421         db_attach->priv = NULL;
 422 }
 423
 424 static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
 425         struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
 426 {
 427         struct vb2_dma_sg_attachment *attach = db_attach->priv;
 428         /* stealing dmabuf mutex to serialize map/unmap operations */
 429         struct mutex *lock = &db_attach->dmabuf->lock;
 430         struct sg_table *sgt;
 431
 432         mutex_lock(lock);
 433
 434         sgt = &attach->sgt;
 435         /* return previously mapped sg table */
 436         if (attach->dma_dir == dma_dir) {
 437                 mutex_unlock(lock);
 438                 return sgt;
 439         }
 440
 441         /* release any previous cache */
 442         if (attach->dma_dir != DMA_NONE) {
 443                 dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, 0);
 444                 attach->dma_dir = DMA_NONE;
 445         }
 446
 447         /* mapping to the client with new direction */
 448         if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 0)) {
 449                 pr_err("failed to map scatterlist\n");
 450                 mutex_unlock(lock);
 451                 return ERR_PTR(-EIO);
 452         }
 453
 454         attach->dma_dir = dma_dir;
 455
 456         mutex_unlock(lock);
 457
 458         return sgt;
 459 }
 460
 461 static void vb2_dma_sg_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
 462         struct sg_table *sgt, enum dma_data_direction dma_dir)
 463 {
 464         /* nothing to be done here */
 465 }
 466
 467 static void vb2_dma_sg_dmabuf_ops_release(struct dma_buf *dbuf)
 468 {
 469         /* drop reference obtained in vb2_dma_sg_get_dmabuf */
 470         vb2_dma_sg_put(dbuf->priv);
 471 }
 472
 473 static int
 474 vb2_dma_sg_dmabuf_ops_begin_cpu_access(struct dma_buf *dbuf,
 475                                        enum dma_data_direction direction)
 476 {
 477         struct vb2_dma_sg_buf *buf = dbuf->priv;
 478         struct sg_table *sgt = buf->dma_sgt;
 479
 480         dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
 481         return 0;
 482 }
 483
 484 static int
 485 vb2_dma_sg_dmabuf_ops_end_cpu_access(struct dma_buf *dbuf,
 486                                      enum dma_data_direction direction)
 487 {
 488         struct vb2_dma_sg_buf *buf = dbuf->priv;
 489         struct sg_table *sgt = buf->dma_sgt;
 490
 491         dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
 492         return 0;
 493 }
 494
 495 static int vb2_dma_sg_dmabuf_ops_vmap(struct dma_buf *dbuf, struct dma_buf_map *map)
 496 {
 497         struct vb2_dma_sg_buf *buf = dbuf->priv;
 498
 499         dma_buf_map_set_vaddr(map, buf->vaddr);
 500
 501         return 0;
 502 }
 503
 504 static int vb2_dma_sg_dmabuf_ops_mmap(struct dma_buf *dbuf,
 505         struct vm_area_struct *vma)
 506 {
 507         return vb2_dma_sg_mmap(dbuf->priv, vma);
 508 }
 509
 510 static const struct dma_buf_ops vb2_dma_sg_dmabuf_ops = {
 511         .attach = vb2_dma_sg_dmabuf_ops_attach,
 512         .detach = vb2_dma_sg_dmabuf_ops_detach,
 513         .map_dma_buf = vb2_dma_sg_dmabuf_ops_map,
 514         .unmap_dma_buf = vb2_dma_sg_dmabuf_ops_unmap,
 515         .begin_cpu_access = vb2_dma_sg_dmabuf_ops_begin_cpu_access,
 516         .end_cpu_access = vb2_dma_sg_dmabuf_ops_end_cpu_access,
 517         .vmap = vb2_dma_sg_dmabuf_ops_vmap,
 518         .mmap = vb2_dma_sg_dmabuf_ops_mmap,
 519         .release = vb2_dma_sg_dmabuf_ops_release,
 520 };
 521
 522 static struct dma_buf *vb2_dma_sg_get_dmabuf(struct vb2_buffer *vb,
 523                                              void *buf_priv,
 524                                              unsigned long flags)
 525 {
 526         struct vb2_dma_sg_buf *buf = buf_priv;
 527         struct dma_buf *dbuf;
 528         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 529
 530         exp_info.ops = &vb2_dma_sg_dmabuf_ops;
 531         exp_info.size = buf->size;
 532         exp_info.flags = flags;
 533         exp_info.priv = buf;
 534
 535         if (WARN_ON(!buf->dma_sgt))
 536                 return NULL;
 537
 538         dbuf = dma_buf_export(&exp_info);
 539         if (IS_ERR(dbuf))
 540                 return NULL;
 541
 542         /* dmabuf keeps reference to vb2 buffer */
 543         refcount_inc(&buf->refcount);
 544
 545         return dbuf;
 546 }
 547
 548 /*********************************************/
 549 /*       callbacks for DMABUF buffers        */
 550 /*********************************************/
 551
 552 static int vb2_dma_sg_map_dmabuf(void *mem_priv)
 553 {
 554         struct vb2_dma_sg_buf *buf = mem_priv;
 555         struct sg_table *sgt;
 556
 557         if (WARN_ON(!buf->db_attach)) {
 558                 pr_err("trying to pin a non attached buffer\n");
 559                 return -EINVAL;
 560         }
 561
 562         if (WARN_ON(buf->dma_sgt)) {
 563                 pr_err("dmabuf buffer is already pinned\n");
 564                 return 0;
 565         }
 566
 567         /* get the associated scatterlist for this buffer */
 568         sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir);
 569         if (IS_ERR(sgt)) {
 570                 pr_err("Error getting dmabuf scatterlist\n");
 571                 return -EINVAL;
 572         }
 573
 574         buf->dma_sgt = sgt;
 575         buf->vaddr = NULL;
 576
 577         return 0;
 578 }
 579
 580 static void vb2_dma_sg_unmap_dmabuf(void *mem_priv)
 581 {
 582         struct vb2_dma_sg_buf *buf = mem_priv;
 583         struct sg_table *sgt = buf->dma_sgt;
 584         struct dma_buf_map map = DMA_BUF_MAP_INIT_VADDR(buf->vaddr);
 585
 586         if (WARN_ON(!buf->db_attach)) {
 587                 pr_err("trying to unpin a not attached buffer\n");
 588                 return;
 589         }
 590
 591         if (WARN_ON(!sgt)) {
 592                 pr_err("dmabuf buffer is already unpinned\n");
 593                 return;
 594         }
 595
 596         if (buf->vaddr) {
 597                 dma_buf_vunmap(buf->db_attach->dmabuf, &map);
 598                 buf->vaddr = NULL;
 599         }
 600         dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir);
 601
 602         buf->dma_sgt = NULL;
 603 }
 604
 605 static void vb2_dma_sg_detach_dmabuf(void *mem_priv)
 606 {
 607         struct vb2_dma_sg_buf *buf = mem_priv;
 608
 609         /* if vb2 works correctly you should never detach mapped buffer */
 610         if (WARN_ON(buf->dma_sgt))
 611                 vb2_dma_sg_unmap_dmabuf(buf);
 612
 613         /* detach this attachment */
 614         dma_buf_detach(buf->db_attach->dmabuf, buf->db_attach);
 615         kfree(buf);
 616 }
 617
 618 static void *vb2_dma_sg_attach_dmabuf(struct vb2_buffer *vb, struct device *dev,
 619                                       struct dma_buf *dbuf, unsigned long size)
 620 {
 621         struct vb2_dma_sg_buf *buf;
 622         struct dma_buf_attachment *dba;
 623
 624         if (WARN_ON(!dev))
 625                 return ERR_PTR(-EINVAL);
 626
 627         if (dbuf->size < size)
 628                 return ERR_PTR(-EFAULT);
 629
 630         buf = kzalloc(sizeof(*buf), GFP_KERNEL);
 631         if (!buf)
 632                 return ERR_PTR(-ENOMEM);
 633
 634         buf->dev = dev;
 635         /* create attachment for the dmabuf with the user device */
 636         dba = dma_buf_attach(dbuf, buf->dev);
 637         if (IS_ERR(dba)) {
 638                 pr_err("failed to attach dmabuf\n");
 639                 kfree(buf);
 640                 return dba;
 641         }
 642
 643         buf->dma_dir = vb->vb2_queue->dma_dir;
 644         buf->size = size;
 645         buf->db_attach = dba;
 646         buf->vb = vb;
 647
 648         return buf;
 649 }
 650
 651 static void *vb2_dma_sg_cookie(struct vb2_buffer *vb, void *buf_priv)
 652 {
 653         struct vb2_dma_sg_buf *buf = buf_priv;
 654
 655         return buf->dma_sgt;
 656 }
 657
 658 const struct vb2_mem_ops vb2_dma_sg_memops = {
 659         .alloc          = vb2_dma_sg_alloc,
 660         .put            = vb2_dma_sg_put,
 661         .get_userptr    = vb2_dma_sg_get_userptr,
 662         .put_userptr    = vb2_dma_sg_put_userptr,
 663         .prepare        = vb2_dma_sg_prepare,
 664         .finish         = vb2_dma_sg_finish,
 665         .vaddr          = vb2_dma_sg_vaddr,
 666         .mmap           = vb2_dma_sg_mmap,
 667         .num_users      = vb2_dma_sg_num_users,
 668         .get_dmabuf     = vb2_dma_sg_get_dmabuf,
 669         .map_dmabuf     = vb2_dma_sg_map_dmabuf,
 670         .unmap_dmabuf   = vb2_dma_sg_unmap_dmabuf,
 671         .attach_dmabuf  = vb2_dma_sg_attach_dmabuf,
 672         .detach_dmabuf  = vb2_dma_sg_detach_dmabuf,
 673         .cookie         = vb2_dma_sg_cookie,
 674 };
 675 EXPORT_SYMBOL_GPL(vb2_dma_sg_memops);
 676
 677 MODULE_DESCRIPTION("dma scatter/gather memory handling routines for videobuf2");
 678 MODULE_AUTHOR("Andrzej Pietrasiewicz");
 679 MODULE_LICENSE("GPL");
 680 MODULE_IMPORT_NS(DMA_BUF);