drivers/media/v4l2-core/videobuf2-core.c

   1 /*
   2  * videobuf2-core.c - video buffer 2 core framework
   3  *
   4  * Copyright (C) 2010 Samsung Electronics
   5  *
   6  * Author: Pawel Osciak <pawel@osciak.com>
   7  *         Marek Szyprowski <m.szyprowski@samsung.com>
   8  *
   9  * The vb2_thread implementation was based on code from videobuf-dvb.c:
  10  *      (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation.
  15  */
  16
  17 #include <linux/err.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/mm.h>
  21 #include <linux/poll.h>
  22 #include <linux/slab.h>
  23 #include <linux/sched.h>
  24 #include <linux/freezer.h>
  25 #include <linux/kthread.h>
  26
  27 #include <media/videobuf2-core.h>
  28 #include <media/v4l2-mc.h>
  29
  30 #include <trace/events/vb2.h>
  31
  32 static int debug;
  33 module_param(debug, int, 0644);
  34
  35 #define dprintk(level, fmt, arg...)                                           \
  36         do {                                                                  \
  37                 if (debug >= level)                                           \
  38                         pr_info("vb2-core: %s: " fmt, __func__, ## arg); \
  39         } while (0)
  40
  41 #ifdef CONFIG_VIDEO_ADV_DEBUG
  42
  43 /*
  44  * If advanced debugging is on, then count how often each op is called
  45  * successfully, which can either be per-buffer or per-queue.
  46  *
  47  * This makes it easy to check that the 'init' and 'cleanup'
  48  * (and variations thereof) stay balanced.
  49  */
  50
  51 #define log_memop(vb, op)                                               \
  52         dprintk(2, "call_memop(%p, %d, %s)%s\n",                        \
  53                 (vb)->vb2_queue, (vb)->index, #op,                      \
  54                 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
  55
  56 #define call_memop(vb, op, args...)                                     \
  57 ({                                                                      \
  58         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  59         int err;                                                        \
  60                                                                         \
  61         log_memop(vb, op);                                              \
  62         err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0;              \
  63         if (!err)                                                       \
  64                 (vb)->cnt_mem_ ## op++;                                 \
  65         err;                                                            \
  66 })
  67
  68 #define call_ptr_memop(vb, op, args...)                                 \
  69 ({                                                                      \
  70         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  71         void *ptr;                                                      \
  72                                                                         \
  73         log_memop(vb, op);                                              \
  74         ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL;           \
  75         if (!IS_ERR_OR_NULL(ptr))                                       \
  76                 (vb)->cnt_mem_ ## op++;                                 \
  77         ptr;                                                            \
  78 })
  79
  80 #define call_void_memop(vb, op, args...)                                \
  81 ({                                                                      \
  82         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  83                                                                         \
  84         log_memop(vb, op);                                              \
  85         if (_q->mem_ops->op)                                            \
  86                 _q->mem_ops->op(args);                                  \
  87         (vb)->cnt_mem_ ## op++;                                         \
  88 })
  89
  90 #define log_qop(q, op)                                                  \
  91         dprintk(2, "call_qop(%p, %s)%s\n", q, #op,                      \
  92                 (q)->ops->op ? "" : " (nop)")
  93
  94 #define call_qop(q, op, args...)                                        \
  95 ({                                                                      \
  96         int err;                                                        \
  97                                                                         \
  98         log_qop(q, op);                                                 \
  99         err = (q)->ops->op ? (q)->ops->op(args) : 0;                    \
 100         if (!err)                                                       \
 101                 (q)->cnt_ ## op++;                                      \
 102         err;                                                            \
 103 })
 104
 105 #define call_void_qop(q, op, args...)                                   \
 106 ({                                                                      \
 107         log_qop(q, op);                                                 \
 108         if ((q)->ops->op)                                               \
 109                 (q)->ops->op(args);                                     \
 110         (q)->cnt_ ## op++;                                              \
 111 })
 112
 113 #define log_vb_qop(vb, op, args...)                                     \
 114         dprintk(2, "call_vb_qop(%p, %d, %s)%s\n",                       \
 115                 (vb)->vb2_queue, (vb)->index, #op,                      \
 116                 (vb)->vb2_queue->ops->op ? "" : " (nop)")
 117
 118 #define call_vb_qop(vb, op, args...)                                    \
 119 ({                                                                      \
 120         int err;                                                        \
 121                                                                         \
 122         log_vb_qop(vb, op);                                             \
 123         err = (vb)->vb2_queue->ops->op ?                                \
 124                 (vb)->vb2_queue->ops->op(args) : 0;                     \
 125         if (!err)                                                       \
 126                 (vb)->cnt_ ## op++;                                     \
 127         err;                                                            \
 128 })
 129
 130 #define call_void_vb_qop(vb, op, args...)                               \
 131 ({                                                                      \
 132         log_vb_qop(vb, op);                                             \
 133         if ((vb)->vb2_queue->ops->op)                                   \
 134                 (vb)->vb2_queue->ops->op(args);                         \
 135         (vb)->cnt_ ## op++;                                             \
 136 })
 137
 138 #else
 139
 140 #define call_memop(vb, op, args...)                                     \
 141         ((vb)->vb2_queue->mem_ops->op ?                                 \
 142                 (vb)->vb2_queue->mem_ops->op(args) : 0)
 143
 144 #define call_ptr_memop(vb, op, args...)                                 \
 145         ((vb)->vb2_queue->mem_ops->op ?                                 \
 146                 (vb)->vb2_queue->mem_ops->op(args) : NULL)
 147
 148 #define call_void_memop(vb, op, args...)                                \
 149         do {                                                            \
 150                 if ((vb)->vb2_queue->mem_ops->op)                       \
 151                         (vb)->vb2_queue->mem_ops->op(args);             \
 152         } while (0)
 153
 154 #define call_qop(q, op, args...)                                        \
 155         ((q)->ops->op ? (q)->ops->op(args) : 0)
 156
 157 #define call_void_qop(q, op, args...)                                   \
 158         do {                                                            \
 159                 if ((q)->ops->op)                                       \
 160                         (q)->ops->op(args);                             \
 161         } while (0)
 162
 163 #define call_vb_qop(vb, op, args...)                                    \
 164         ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
 165
 166 #define call_void_vb_qop(vb, op, args...)                               \
 167         do {                                                            \
 168                 if ((vb)->vb2_queue->ops->op)                           \
 169                         (vb)->vb2_queue->ops->op(args);                 \
 170         } while (0)
 171
 172 #endif
 173
 174 #define call_bufop(q, op, args...)                                      \
 175 ({                                                                      \
 176         int ret = 0;                                                    \
 177         if (q && q->buf_ops && q->buf_ops->op)                          \
 178                 ret = q->buf_ops->op(args);                             \
 179         ret;                                                            \
 180 })
 181
 182 #define call_void_bufop(q, op, args...)                                 \
 183 ({                                                                      \
 184         if (q && q->buf_ops && q->buf_ops->op)                          \
 185                 q->buf_ops->op(args);                                   \
 186 })
 187
 188 static void __vb2_queue_cancel(struct vb2_queue *q);
 189 static void __enqueue_in_driver(struct vb2_buffer *vb);
 190
 191 /**
 192  * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
 193  */
 194 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
 195 {
 196         struct vb2_queue *q = vb->vb2_queue;
 197         enum dma_data_direction dma_dir =
 198                 q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
 199         void *mem_priv;
 200         int plane;
 201         int ret = -ENOMEM;
 202
 203         /*
 204          * Allocate memory for all planes in this buffer
 205          * NOTE: mmapped areas should be page aligned
 206          */
 207         for (plane = 0; plane < vb->num_planes; ++plane) {
 208                 unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
 209
 210                 mem_priv = call_ptr_memop(vb, alloc,
 211                                 q->alloc_devs[plane] ? : q->dev,
 212                                 q->dma_attrs, size, dma_dir, q->gfp_flags);
 213                 if (IS_ERR(mem_priv)) {
 214                         if (mem_priv)
 215                                 ret = PTR_ERR(mem_priv);
 216                         goto free;
 217                 }
 218
 219                 /* Associate allocator private data with this plane */
 220                 vb->planes[plane].mem_priv = mem_priv;
 221         }
 222
 223         return 0;
 224 free:
 225         /* Free already allocated memory if one of the allocations failed */
 226         for (; plane > 0; --plane) {
 227                 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
 228                 vb->planes[plane - 1].mem_priv = NULL;
 229         }
 230
 231         return ret;
 232 }
 233
 234 /**
 235  * __vb2_buf_mem_free() - free memory of the given buffer
 236  */
 237 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
 238 {
 239         unsigned int plane;
 240
 241         for (plane = 0; plane < vb->num_planes; ++plane) {
 242                 call_void_memop(vb, put, vb->planes[plane].mem_priv);
 243                 vb->planes[plane].mem_priv = NULL;
 244                 dprintk(3, "freed plane %d of buffer %d\n", plane, vb->index);
 245         }
 246 }
 247
 248 /**
 249  * __vb2_buf_userptr_put() - release userspace memory associated with
 250  * a USERPTR buffer
 251  */
 252 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
 253 {
 254         unsigned int plane;
 255
 256         for (plane = 0; plane < vb->num_planes; ++plane) {
 257                 if (vb->planes[plane].mem_priv)
 258                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
 259                 vb->planes[plane].mem_priv = NULL;
 260         }
 261 }
 262
 263 /**
 264  * __vb2_plane_dmabuf_put() - release memory associated with
 265  * a DMABUF shared plane
 266  */
 267 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
 268 {
 269         if (!p->mem_priv)
 270                 return;
 271
 272         if (p->dbuf_mapped)
 273                 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
 274
 275         call_void_memop(vb, detach_dmabuf, p->mem_priv);
 276         dma_buf_put(p->dbuf);
 277         p->mem_priv = NULL;
 278         p->dbuf = NULL;
 279         p->dbuf_mapped = 0;
 280 }
 281
 282 /**
 283  * __vb2_buf_dmabuf_put() - release memory associated with
 284  * a DMABUF shared buffer
 285  */
 286 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
 287 {
 288         unsigned int plane;
 289
 290         for (plane = 0; plane < vb->num_planes; ++plane)
 291                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
 292 }
 293
 294 /**
 295  * __setup_offsets() - setup unique offsets ("cookies") for every plane in
 296  * the buffer.
 297  */
 298 static void __setup_offsets(struct vb2_buffer *vb)
 299 {
 300         struct vb2_queue *q = vb->vb2_queue;
 301         unsigned int plane;
 302         unsigned long off = 0;
 303
 304         if (vb->index) {
 305                 struct vb2_buffer *prev = q->bufs[vb->index - 1];
 306                 struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
 307
 308                 off = PAGE_ALIGN(p->m.offset + p->length);
 309         }
 310
 311         for (plane = 0; plane < vb->num_planes; ++plane) {
 312                 vb->planes[plane].m.offset = off;
 313
 314                 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
 315                                 vb->index, plane, off);
 316
 317                 off += vb->planes[plane].length;
 318                 off = PAGE_ALIGN(off);
 319         }
 320 }
 321
 322 /**
 323  * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
 324  * video buffer memory for all buffers/planes on the queue and initializes the
 325  * queue
 326  *
 327  * Returns the number of buffers successfully allocated.
 328  */
 329 static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
 330                              unsigned int num_buffers, unsigned int num_planes,
 331                              const unsigned plane_sizes[VB2_MAX_PLANES])
 332 {
 333         unsigned int buffer, plane;
 334         struct vb2_buffer *vb;
 335         int ret;
 336
 337         for (buffer = 0; buffer < num_buffers; ++buffer) {
 338                 /* Allocate videobuf buffer structures */
 339                 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
 340                 if (!vb) {
 341                         dprintk(1, "memory alloc for buffer struct failed\n");
 342                         break;
 343                 }
 344
 345                 vb->state = VB2_BUF_STATE_DEQUEUED;
 346                 vb->vb2_queue = q;
 347                 vb->num_planes = num_planes;
 348                 vb->index = q->num_buffers + buffer;
 349                 vb->type = q->type;
 350                 vb->memory = memory;
 351                 for (plane = 0; plane < num_planes; ++plane) {
 352                         vb->planes[plane].length = plane_sizes[plane];
 353                         vb->planes[plane].min_length = plane_sizes[plane];
 354                 }
 355                 q->bufs[vb->index] = vb;
 356
 357                 /* Allocate video buffer memory for the MMAP type */
 358                 if (memory == VB2_MEMORY_MMAP) {
 359                         ret = __vb2_buf_mem_alloc(vb);
 360                         if (ret) {
 361                                 dprintk(1, "failed allocating memory for buffer %d\n",
 362                                         buffer);
 363                                 q->bufs[vb->index] = NULL;
 364                                 kfree(vb);
 365                                 break;
 366                         }
 367                         __setup_offsets(vb);
 368                         /*
 369                          * Call the driver-provided buffer initialization
 370                          * callback, if given. An error in initialization
 371                          * results in queue setup failure.
 372                          */
 373                         ret = call_vb_qop(vb, buf_init, vb);
 374                         if (ret) {
 375                                 dprintk(1, "buffer %d %p initialization failed\n",
 376                                         buffer, vb);
 377                                 __vb2_buf_mem_free(vb);
 378                                 q->bufs[vb->index] = NULL;
 379                                 kfree(vb);
 380                                 break;
 381                         }
 382                 }
 383         }
 384
 385         dprintk(1, "allocated %d buffers, %d plane(s) each\n",
 386                         buffer, num_planes);
 387
 388         return buffer;
 389 }
 390
 391 /**
 392  * __vb2_free_mem() - release all video buffer memory for a given queue
 393  */
 394 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
 395 {
 396         unsigned int buffer;
 397         struct vb2_buffer *vb;
 398
 399         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 400              ++buffer) {
 401                 vb = q->bufs[buffer];
 402                 if (!vb)
 403                         continue;
 404
 405                 /* Free MMAP buffers or release USERPTR buffers */
 406                 if (q->memory == VB2_MEMORY_MMAP)
 407                         __vb2_buf_mem_free(vb);
 408                 else if (q->memory == VB2_MEMORY_DMABUF)
 409                         __vb2_buf_dmabuf_put(vb);
 410                 else
 411                         __vb2_buf_userptr_put(vb);
 412         }
 413 }
 414
 415 /**
 416  * __vb2_queue_free() - free buffers at the end of the queue - video memory and
 417  * related information, if no buffers are left return the queue to an
 418  * uninitialized state. Might be called even if the queue has already been freed.
 419  */
 420 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
 421 {
 422         unsigned int buffer;
 423
 424         /*
 425          * Sanity check: when preparing a buffer the queue lock is released for
 426          * a short while (see __buf_prepare for the details), which would allow
 427          * a race with a reqbufs which can call this function. Removing the
 428          * buffers from underneath __buf_prepare is obviously a bad idea, so we
 429          * check if any of the buffers is in the state PREPARING, and if so we
 430          * just return -EAGAIN.
 431          */
 432         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 433              ++buffer) {
 434                 if (q->bufs[buffer] == NULL)
 435                         continue;
 436                 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
 437                         dprintk(1, "preparing buffers, cannot free\n");
 438                         return -EAGAIN;
 439                 }
 440         }
 441
 442         /* Call driver-provided cleanup function for each buffer, if provided */
 443         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 444              ++buffer) {
 445                 struct vb2_buffer *vb = q->bufs[buffer];
 446
 447                 if (vb && vb->planes[0].mem_priv)
 448                         call_void_vb_qop(vb, buf_cleanup, vb);
 449         }
 450
 451         /* Release video buffer memory */
 452         __vb2_free_mem(q, buffers);
 453
 454 #ifdef CONFIG_VIDEO_ADV_DEBUG
 455         /*
 456          * Check that all the calls were balances during the life-time of this
 457          * queue. If not (or if the debug level is 1 or up), then dump the
 458          * counters to the kernel log.
 459          */
 460         if (q->num_buffers) {
 461                 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
 462                                   q->cnt_wait_prepare != q->cnt_wait_finish;
 463
 464                 if (unbalanced || debug) {
 465                         pr_info("vb2: counters for queue %p:%s\n", q,
 466                                 unbalanced ? " UNBALANCED!" : "");
 467                         pr_info("vb2:     setup: %u start_streaming: %u stop_streaming: %u\n",
 468                                 q->cnt_queue_setup, q->cnt_start_streaming,
 469                                 q->cnt_stop_streaming);
 470                         pr_info("vb2:     wait_prepare: %u wait_finish: %u\n",
 471                                 q->cnt_wait_prepare, q->cnt_wait_finish);
 472                 }
 473                 q->cnt_queue_setup = 0;
 474                 q->cnt_wait_prepare = 0;
 475                 q->cnt_wait_finish = 0;
 476                 q->cnt_start_streaming = 0;
 477                 q->cnt_stop_streaming = 0;
 478         }
 479         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 480                 struct vb2_buffer *vb = q->bufs[buffer];
 481                 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
 482                                   vb->cnt_mem_prepare != vb->cnt_mem_finish ||
 483                                   vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
 484                                   vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
 485                                   vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
 486                                   vb->cnt_buf_queue != vb->cnt_buf_done ||
 487                                   vb->cnt_buf_prepare != vb->cnt_buf_finish ||
 488                                   vb->cnt_buf_init != vb->cnt_buf_cleanup;
 489
 490                 if (unbalanced || debug) {
 491                         pr_info("vb2:   counters for queue %p, buffer %d:%s\n",
 492                                 q, buffer, unbalanced ? " UNBALANCED!" : "");
 493                         pr_info("vb2:     buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
 494                                 vb->cnt_buf_init, vb->cnt_buf_cleanup,
 495                                 vb->cnt_buf_prepare, vb->cnt_buf_finish);
 496                         pr_info("vb2:     buf_queue: %u buf_done: %u\n",
 497                                 vb->cnt_buf_queue, vb->cnt_buf_done);
 498                         pr_info("vb2:     alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
 499                                 vb->cnt_mem_alloc, vb->cnt_mem_put,
 500                                 vb->cnt_mem_prepare, vb->cnt_mem_finish,
 501                                 vb->cnt_mem_mmap);
 502                         pr_info("vb2:     get_userptr: %u put_userptr: %u\n",
 503                                 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
 504                         pr_info("vb2:     attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
 505                                 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
 506                                 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
 507                         pr_info("vb2:     get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
 508                                 vb->cnt_mem_get_dmabuf,
 509                                 vb->cnt_mem_num_users,
 510                                 vb->cnt_mem_vaddr,
 511                                 vb->cnt_mem_cookie);
 512                 }
 513         }
 514 #endif
 515
 516         /* Free videobuf buffers */
 517         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 518              ++buffer) {
 519                 kfree(q->bufs[buffer]);
 520                 q->bufs[buffer] = NULL;
 521         }
 522
 523         q->num_buffers -= buffers;
 524         if (!q->num_buffers) {
 525                 q->memory = 0;
 526                 INIT_LIST_HEAD(&q->queued_list);
 527         }
 528         return 0;
 529 }
 530
 531 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
 532 {
 533         unsigned int plane;
 534         for (plane = 0; plane < vb->num_planes; ++plane) {
 535                 void *mem_priv = vb->planes[plane].mem_priv;
 536                 /*
 537                  * If num_users() has not been provided, call_memop
 538                  * will return 0, apparently nobody cares about this
 539                  * case anyway. If num_users() returns more than 1,
 540                  * we are not the only user of the plane's memory.
 541                  */
 542                 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
 543                         return true;
 544         }
 545         return false;
 546 }
 547 EXPORT_SYMBOL(vb2_buffer_in_use);
 548
 549 /**
 550  * __buffers_in_use() - return true if any buffers on the queue are in use and
 551  * the queue cannot be freed (by the means of REQBUFS(0)) call
 552  */
 553 static bool __buffers_in_use(struct vb2_queue *q)
 554 {
 555         unsigned int buffer;
 556         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 557                 if (vb2_buffer_in_use(q, q->bufs[buffer]))
 558                         return true;
 559         }
 560         return false;
 561 }
 562
 563 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
 564 {
 565         call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
 566 }
 567 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
 568
 569 /**
 570  * __verify_userptr_ops() - verify that all memory operations required for
 571  * USERPTR queue type have been provided
 572  */
 573 static int __verify_userptr_ops(struct vb2_queue *q)
 574 {
 575         if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
 576             !q->mem_ops->put_userptr)
 577                 return -EINVAL;
 578
 579         return 0;
 580 }
 581
 582 /**
 583  * __verify_mmap_ops() - verify that all memory operations required for
 584  * MMAP queue type have been provided
 585  */
 586 static int __verify_mmap_ops(struct vb2_queue *q)
 587 {
 588         if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
 589             !q->mem_ops->put || !q->mem_ops->mmap)
 590                 return -EINVAL;
 591
 592         return 0;
 593 }
 594
 595 /**
 596  * __verify_dmabuf_ops() - verify that all memory operations required for
 597  * DMABUF queue type have been provided
 598  */
 599 static int __verify_dmabuf_ops(struct vb2_queue *q)
 600 {
 601         if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
 602             !q->mem_ops->detach_dmabuf  || !q->mem_ops->map_dmabuf ||
 603             !q->mem_ops->unmap_dmabuf)
 604                 return -EINVAL;
 605
 606         return 0;
 607 }
 608
 609 int vb2_verify_memory_type(struct vb2_queue *q,
 610                 enum vb2_memory memory, unsigned int type)
 611 {
 612         if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
 613             memory != VB2_MEMORY_DMABUF) {
 614                 dprintk(1, "unsupported memory type\n");
 615                 return -EINVAL;
 616         }
 617
 618         if (type != q->type) {
 619                 dprintk(1, "requested type is incorrect\n");
 620                 return -EINVAL;
 621         }
 622
 623         /*
 624          * Make sure all the required memory ops for given memory type
 625          * are available.
 626          */
 627         if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
 628                 dprintk(1, "MMAP for current setup unsupported\n");
 629                 return -EINVAL;
 630         }
 631
 632         if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
 633                 dprintk(1, "USERPTR for current setup unsupported\n");
 634                 return -EINVAL;
 635         }
 636
 637         if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
 638                 dprintk(1, "DMABUF for current setup unsupported\n");
 639                 return -EINVAL;
 640         }
 641
 642         /*
 643          * Place the busy tests at the end: -EBUSY can be ignored when
 644          * create_bufs is called with count == 0, but count == 0 should still
 645          * do the memory and type validation.
 646          */
 647         if (vb2_fileio_is_active(q)) {
 648                 dprintk(1, "file io in progress\n");
 649                 return -EBUSY;
 650         }
 651         return 0;
 652 }
 653 EXPORT_SYMBOL(vb2_verify_memory_type);
 654
 655 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 656                 unsigned int *count)
 657 {
 658         unsigned int num_buffers, allocated_buffers, num_planes = 0;
 659         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 660         int ret;
 661
 662         if (q->streaming) {
 663                 dprintk(1, "streaming active\n");
 664                 return -EBUSY;
 665         }
 666
 667         if (*count == 0 || q->num_buffers != 0 || q->memory != memory) {
 668                 /*
 669                  * We already have buffers allocated, so first check if they
 670                  * are not in use and can be freed.
 671                  */
 672                 mutex_lock(&q->mmap_lock);
 673                 if (q->memory == VB2_MEMORY_MMAP && __buffers_in_use(q)) {
 674                         mutex_unlock(&q->mmap_lock);
 675                         dprintk(1, "memory in use, cannot free\n");
 676                         return -EBUSY;
 677                 }
 678
 679                 /*
 680                  * Call queue_cancel to clean up any buffers in the PREPARED or
 681                  * QUEUED state which is possible if buffers were prepared or
 682                  * queued without ever calling STREAMON.
 683                  */
 684                 __vb2_queue_cancel(q);
 685                 ret = __vb2_queue_free(q, q->num_buffers);
 686                 mutex_unlock(&q->mmap_lock);
 687                 if (ret)
 688                         return ret;
 689
 690                 /*
 691                  * In case of REQBUFS(0) return immediately without calling
 692                  * driver's queue_setup() callback and allocating resources.
 693                  */
 694                 if (*count == 0)
 695                         return 0;
 696         }
 697
 698         /*
 699          * Make sure the requested values and current defaults are sane.
 700          */
 701         num_buffers = min_t(unsigned int, *count, VB2_MAX_FRAME);
 702         num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
 703         memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 704         q->memory = memory;
 705
 706         /*
 707          * Ask the driver how many buffers and planes per buffer it requires.
 708          * Driver also sets the size and allocator context for each plane.
 709          */
 710         ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
 711                        plane_sizes, q->alloc_devs);
 712         if (ret)
 713                 return ret;
 714
 715         /* Finally, allocate buffers and video memory */
 716         allocated_buffers =
 717                 __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
 718         if (allocated_buffers == 0) {
 719                 dprintk(1, "memory allocation failed\n");
 720                 return -ENOMEM;
 721         }
 722
 723         /*
 724          * There is no point in continuing if we can't allocate the minimum
 725          * number of buffers needed by this vb2_queue.
 726          */
 727         if (allocated_buffers < q->min_buffers_needed)
 728                 ret = -ENOMEM;
 729
 730         /*
 731          * Check if driver can handle the allocated number of buffers.
 732          */
 733         if (!ret && allocated_buffers < num_buffers) {
 734                 num_buffers = allocated_buffers;
 735                 /*
 736                  * num_planes is set by the previous queue_setup(), but since it
 737                  * signals to queue_setup() whether it is called from create_bufs()
 738                  * vs reqbufs() we zero it here to signal that queue_setup() is
 739                  * called for the reqbufs() case.
 740                  */
 741                 num_planes = 0;
 742
 743                 ret = call_qop(q, queue_setup, q, &num_buffers,
 744                                &num_planes, plane_sizes, q->alloc_devs);
 745
 746                 if (!ret && allocated_buffers < num_buffers)
 747                         ret = -ENOMEM;
 748
 749                 /*
 750                  * Either the driver has accepted a smaller number of buffers,
 751                  * or .queue_setup() returned an error
 752                  */
 753         }
 754
 755         mutex_lock(&q->mmap_lock);
 756         q->num_buffers = allocated_buffers;
 757
 758         if (ret < 0) {
 759                 /*
 760                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 761                  * from q->num_buffers.
 762                  */
 763                 __vb2_queue_free(q, allocated_buffers);
 764                 mutex_unlock(&q->mmap_lock);
 765                 return ret;
 766         }
 767         mutex_unlock(&q->mmap_lock);
 768
 769         /*
 770          * Return the number of successfully allocated buffers
 771          * to the userspace.
 772          */
 773         *count = allocated_buffers;
 774         q->waiting_for_buffers = !q->is_output;
 775
 776         return 0;
 777 }
 778 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
 779
 780 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 781                 unsigned int *count, unsigned requested_planes,
 782                 const unsigned requested_sizes[])
 783 {
 784         unsigned int num_planes = 0, num_buffers, allocated_buffers;
 785         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 786         int ret;
 787
 788         if (q->num_buffers == VB2_MAX_FRAME) {
 789                 dprintk(1, "maximum number of buffers already allocated\n");
 790                 return -ENOBUFS;
 791         }
 792
 793         if (!q->num_buffers) {
 794                 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 795                 q->memory = memory;
 796                 q->waiting_for_buffers = !q->is_output;
 797         }
 798
 799         num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
 800
 801         if (requested_planes && requested_sizes) {
 802                 num_planes = requested_planes;
 803                 memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
 804         }
 805
 806         /*
 807          * Ask the driver, whether the requested number of buffers, planes per
 808          * buffer and their sizes are acceptable
 809          */
 810         ret = call_qop(q, queue_setup, q, &num_buffers,
 811                        &num_planes, plane_sizes, q->alloc_devs);
 812         if (ret)
 813                 return ret;
 814
 815         /* Finally, allocate buffers and video memory */
 816         allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
 817                                 num_planes, plane_sizes);
 818         if (allocated_buffers == 0) {
 819                 dprintk(1, "memory allocation failed\n");
 820                 return -ENOMEM;
 821         }
 822
 823         /*
 824          * Check if driver can handle the so far allocated number of buffers.
 825          */
 826         if (allocated_buffers < num_buffers) {
 827                 num_buffers = allocated_buffers;
 828
 829                 /*
 830                  * q->num_buffers contains the total number of buffers, that the
 831                  * queue driver has set up
 832                  */
 833                 ret = call_qop(q, queue_setup, q, &num_buffers,
 834                                &num_planes, plane_sizes, q->alloc_devs);
 835
 836                 if (!ret && allocated_buffers < num_buffers)
 837                         ret = -ENOMEM;
 838
 839                 /*
 840                  * Either the driver has accepted a smaller number of buffers,
 841                  * or .queue_setup() returned an error
 842                  */
 843         }
 844
 845         mutex_lock(&q->mmap_lock);
 846         q->num_buffers += allocated_buffers;
 847
 848         if (ret < 0) {
 849                 /*
 850                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 851                  * from q->num_buffers.
 852                  */
 853                 __vb2_queue_free(q, allocated_buffers);
 854                 mutex_unlock(&q->mmap_lock);
 855                 return -ENOMEM;
 856         }
 857         mutex_unlock(&q->mmap_lock);
 858
 859         /*
 860          * Return the number of successfully allocated buffers
 861          * to the userspace.
 862          */
 863         *count = allocated_buffers;
 864
 865         return 0;
 866 }
 867 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
 868
 869 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
 870 {
 871         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
 872                 return NULL;
 873
 874         return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
 875
 876 }
 877 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
 878
 879 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
 880 {
 881         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
 882                 return NULL;
 883
 884         return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
 885 }
 886 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
 887
 888 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
 889 {
 890         struct vb2_queue *q = vb->vb2_queue;
 891         unsigned long flags;
 892         unsigned int plane;
 893
 894         if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
 895                 return;
 896
 897         if (WARN_ON(state != VB2_BUF_STATE_DONE &&
 898                     state != VB2_BUF_STATE_ERROR &&
 899                     state != VB2_BUF_STATE_QUEUED &&
 900                     state != VB2_BUF_STATE_REQUEUEING))
 901                 state = VB2_BUF_STATE_ERROR;
 902
 903 #ifdef CONFIG_VIDEO_ADV_DEBUG
 904         /*
 905          * Although this is not a callback, it still does have to balance
 906          * with the buf_queue op. So update this counter manually.
 907          */
 908         vb->cnt_buf_done++;
 909 #endif
 910         dprintk(4, "done processing on buffer %d, state: %d\n",
 911                         vb->index, state);
 912
 913         /* sync buffers */
 914         for (plane = 0; plane < vb->num_planes; ++plane)
 915                 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
 916
 917         spin_lock_irqsave(&q->done_lock, flags);
 918         if (state == VB2_BUF_STATE_QUEUED ||
 919             state == VB2_BUF_STATE_REQUEUEING) {
 920                 vb->state = VB2_BUF_STATE_QUEUED;
 921         } else {
 922                 /* Add the buffer to the done buffers list */
 923                 list_add_tail(&vb->done_entry, &q->done_list);
 924                 vb->state = state;
 925         }
 926         atomic_dec(&q->owned_by_drv_count);
 927         spin_unlock_irqrestore(&q->done_lock, flags);
 928
 929         trace_vb2_buf_done(q, vb);
 930
 931         switch (state) {
 932         case VB2_BUF_STATE_QUEUED:
 933                 return;
 934         case VB2_BUF_STATE_REQUEUEING:
 935                 if (q->start_streaming_called)
 936                         __enqueue_in_driver(vb);
 937                 return;
 938         default:
 939                 /* Inform any processes that may be waiting for buffers */
 940                 wake_up(&q->done_wq);
 941                 break;
 942         }
 943 }
 944 EXPORT_SYMBOL_GPL(vb2_buffer_done);
 945
 946 void vb2_discard_done(struct vb2_queue *q)
 947 {
 948         struct vb2_buffer *vb;
 949         unsigned long flags;
 950
 951         spin_lock_irqsave(&q->done_lock, flags);
 952         list_for_each_entry(vb, &q->done_list, done_entry)
 953                 vb->state = VB2_BUF_STATE_ERROR;
 954         spin_unlock_irqrestore(&q->done_lock, flags);
 955 }
 956 EXPORT_SYMBOL_GPL(vb2_discard_done);
 957
 958 /**
 959  * __qbuf_mmap() - handle qbuf of an MMAP buffer
 960  */
 961 static int __qbuf_mmap(struct vb2_buffer *vb, const void *pb)
 962 {
 963         int ret = 0;
 964
 965         if (pb)
 966                 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
 967                                  vb, pb, vb->planes);
 968         return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
 969 }
 970
 971 /**
 972  * __qbuf_userptr() - handle qbuf of a USERPTR buffer
 973  */
 974 static int __qbuf_userptr(struct vb2_buffer *vb, const void *pb)
 975 {
 976         struct vb2_plane planes[VB2_MAX_PLANES];
 977         struct vb2_queue *q = vb->vb2_queue;
 978         void *mem_priv;
 979         unsigned int plane;
 980         int ret = 0;
 981         enum dma_data_direction dma_dir =
 982                 q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
 983         bool reacquired = vb->planes[0].mem_priv == NULL;
 984
 985         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
 986         /* Copy relevant information provided by the userspace */
 987         if (pb) {
 988                 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
 989                                  vb, pb, planes);
 990                 if (ret)
 991                         return ret;
 992         }
 993
 994         for (plane = 0; plane < vb->num_planes; ++plane) {
 995                 /* Skip the plane if already verified */
 996                 if (vb->planes[plane].m.userptr &&
 997                         vb->planes[plane].m.userptr == planes[plane].m.userptr
 998                         && vb->planes[plane].length == planes[plane].length)
 999                         continue;
1000
1001                 dprintk(3, "userspace address for plane %d changed, reacquiring memory\n",
1002                         plane);
1003
1004                 /* Check if the provided plane buffer is large enough */
1005                 if (planes[plane].length < vb->planes[plane].min_length) {
1006                         dprintk(1, "provided buffer size %u is less than setup size %u for plane %d\n",
1007                                                 planes[plane].length,
1008                                                 vb->planes[plane].min_length,
1009                                                 plane);
1010                         ret = -EINVAL;
1011                         goto err;
1012                 }
1013
1014                 /* Release previously acquired memory if present */
1015                 if (vb->planes[plane].mem_priv) {
1016                         if (!reacquired) {
1017                                 reacquired = true;
1018                                 call_void_vb_qop(vb, buf_cleanup, vb);
1019                         }
1020                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1021                 }
1022
1023                 vb->planes[plane].mem_priv = NULL;
1024                 vb->planes[plane].bytesused = 0;
1025                 vb->planes[plane].length = 0;
1026                 vb->planes[plane].m.userptr = 0;
1027                 vb->planes[plane].data_offset = 0;
1028
1029                 /* Acquire each plane's memory */
1030                 mem_priv = call_ptr_memop(vb, get_userptr,
1031                                 q->alloc_devs[plane] ? : q->dev,
1032                                 planes[plane].m.userptr,
1033                                 planes[plane].length, dma_dir);
1034                 if (IS_ERR(mem_priv)) {
1035                         dprintk(1, "failed acquiring userspace memory for plane %d\n",
1036                                 plane);
1037                         ret = PTR_ERR(mem_priv);
1038                         goto err;
1039                 }
1040                 vb->planes[plane].mem_priv = mem_priv;
1041         }
1042
1043         /*
1044          * Now that everything is in order, copy relevant information
1045          * provided by userspace.
1046          */
1047         for (plane = 0; plane < vb->num_planes; ++plane) {
1048                 vb->planes[plane].bytesused = planes[plane].bytesused;
1049                 vb->planes[plane].length = planes[plane].length;
1050                 vb->planes[plane].m.userptr = planes[plane].m.userptr;
1051                 vb->planes[plane].data_offset = planes[plane].data_offset;
1052         }
1053
1054         if (reacquired) {
1055                 /*
1056                  * One or more planes changed, so we must call buf_init to do
1057                  * the driver-specific initialization on the newly acquired
1058                  * buffer, if provided.
1059                  */
1060                 ret = call_vb_qop(vb, buf_init, vb);
1061                 if (ret) {
1062                         dprintk(1, "buffer initialization failed\n");
1063                         goto err;
1064                 }
1065         }
1066
1067         ret = call_vb_qop(vb, buf_prepare, vb);
1068         if (ret) {
1069                 dprintk(1, "buffer preparation failed\n");
1070                 call_void_vb_qop(vb, buf_cleanup, vb);
1071                 goto err;
1072         }
1073
1074         return 0;
1075 err:
1076         /* In case of errors, release planes that were already acquired */
1077         for (plane = 0; plane < vb->num_planes; ++plane) {
1078                 if (vb->planes[plane].mem_priv)
1079                         call_void_memop(vb, put_userptr,
1080                                 vb->planes[plane].mem_priv);
1081                 vb->planes[plane].mem_priv = NULL;
1082                 vb->planes[plane].m.userptr = 0;
1083                 vb->planes[plane].length = 0;
1084         }
1085
1086         return ret;
1087 }
1088
1089 /**
1090  * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1091  */
1092 static int __qbuf_dmabuf(struct vb2_buffer *vb, const void *pb)
1093 {
1094         struct vb2_plane planes[VB2_MAX_PLANES];
1095         struct vb2_queue *q = vb->vb2_queue;
1096         void *mem_priv;
1097         unsigned int plane;
1098         int ret = 0;
1099         enum dma_data_direction dma_dir =
1100                 q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
1101         bool reacquired = vb->planes[0].mem_priv == NULL;
1102
1103         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1104         /* Copy relevant information provided by the userspace */
1105         if (pb) {
1106                 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1107                                  vb, pb, planes);
1108                 if (ret)
1109                         return ret;
1110         }
1111
1112         for (plane = 0; plane < vb->num_planes; ++plane) {
1113                 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1114
1115                 if (IS_ERR_OR_NULL(dbuf)) {
1116                         dprintk(1, "invalid dmabuf fd for plane %d\n",
1117                                 plane);
1118                         ret = -EINVAL;
1119                         goto err;
1120                 }
1121
1122                 /* use DMABUF size if length is not provided */
1123                 if (planes[plane].length == 0)
1124                         planes[plane].length = dbuf->size;
1125
1126                 if (planes[plane].length < vb->planes[plane].min_length) {
1127                         dprintk(1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
1128                                 planes[plane].length, plane,
1129                                 vb->planes[plane].min_length);
1130                         dma_buf_put(dbuf);
1131                         ret = -EINVAL;
1132                         goto err;
1133                 }
1134
1135                 /* Skip the plane if already verified */
1136                 if (dbuf == vb->planes[plane].dbuf &&
1137                         vb->planes[plane].length == planes[plane].length) {
1138                         dma_buf_put(dbuf);
1139                         continue;
1140                 }
1141
1142                 dprintk(1, "buffer for plane %d changed\n", plane);
1143
1144                 if (!reacquired) {
1145                         reacquired = true;
1146                         call_void_vb_qop(vb, buf_cleanup, vb);
1147                 }
1148
1149                 /* Release previously acquired memory if present */
1150                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1151                 vb->planes[plane].bytesused = 0;
1152                 vb->planes[plane].length = 0;
1153                 vb->planes[plane].m.fd = 0;
1154                 vb->planes[plane].data_offset = 0;
1155
1156                 /* Acquire each plane's memory */
1157                 mem_priv = call_ptr_memop(vb, attach_dmabuf,
1158                                 q->alloc_devs[plane] ? : q->dev,
1159                                 dbuf, planes[plane].length, dma_dir);
1160                 if (IS_ERR(mem_priv)) {
1161                         dprintk(1, "failed to attach dmabuf\n");
1162                         ret = PTR_ERR(mem_priv);
1163                         dma_buf_put(dbuf);
1164                         goto err;
1165                 }
1166
1167                 vb->planes[plane].dbuf = dbuf;
1168                 vb->planes[plane].mem_priv = mem_priv;
1169         }
1170
1171         /*
1172          * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1173          * here instead just before the DMA, while queueing the buffer(s) so
1174          * userspace knows sooner rather than later if the dma-buf map fails.
1175          */
1176         for (plane = 0; plane < vb->num_planes; ++plane) {
1177                 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1178                 if (ret) {
1179                         dprintk(1, "failed to map dmabuf for plane %d\n",
1180                                 plane);
1181                         goto err;
1182                 }
1183                 vb->planes[plane].dbuf_mapped = 1;
1184         }
1185
1186         /*
1187          * Now that everything is in order, copy relevant information
1188          * provided by userspace.
1189          */
1190         for (plane = 0; plane < vb->num_planes; ++plane) {
1191                 vb->planes[plane].bytesused = planes[plane].bytesused;
1192                 vb->planes[plane].length = planes[plane].length;
1193                 vb->planes[plane].m.fd = planes[plane].m.fd;
1194                 vb->planes[plane].data_offset = planes[plane].data_offset;
1195         }
1196
1197         if (reacquired) {
1198                 /*
1199                  * Call driver-specific initialization on the newly acquired buffer,
1200                  * if provided.
1201                  */
1202                 ret = call_vb_qop(vb, buf_init, vb);
1203                 if (ret) {
1204                         dprintk(1, "buffer initialization failed\n");
1205                         goto err;
1206                 }
1207         }
1208
1209         ret = call_vb_qop(vb, buf_prepare, vb);
1210         if (ret) {
1211                 dprintk(1, "buffer preparation failed\n");
1212                 call_void_vb_qop(vb, buf_cleanup, vb);
1213                 goto err;
1214         }
1215
1216         return 0;
1217 err:
1218         /* In case of errors, release planes that were already acquired */
1219         __vb2_buf_dmabuf_put(vb);
1220
1221         return ret;
1222 }
1223
1224 /**
1225  * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1226  */
1227 static void __enqueue_in_driver(struct vb2_buffer *vb)
1228 {
1229         struct vb2_queue *q = vb->vb2_queue;
1230         unsigned int plane;
1231
1232         vb->state = VB2_BUF_STATE_ACTIVE;
1233         atomic_inc(&q->owned_by_drv_count);
1234
1235         trace_vb2_buf_queue(q, vb);
1236
1237         /* sync buffers */
1238         for (plane = 0; plane < vb->num_planes; ++plane)
1239                 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1240
1241         call_void_vb_qop(vb, buf_queue, vb);
1242 }
1243
1244 static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
1245 {
1246         struct vb2_queue *q = vb->vb2_queue;
1247         int ret;
1248
1249         if (q->error) {
1250                 dprintk(1, "fatal error occurred on queue\n");
1251                 return -EIO;
1252         }
1253
1254         vb->state = VB2_BUF_STATE_PREPARING;
1255
1256         switch (q->memory) {
1257         case VB2_MEMORY_MMAP:
1258                 ret = __qbuf_mmap(vb, pb);
1259                 break;
1260         case VB2_MEMORY_USERPTR:
1261                 ret = __qbuf_userptr(vb, pb);
1262                 break;
1263         case VB2_MEMORY_DMABUF:
1264                 ret = __qbuf_dmabuf(vb, pb);
1265                 break;
1266         default:
1267                 WARN(1, "Invalid queue type\n");
1268                 ret = -EINVAL;
1269         }
1270
1271         if (ret)
1272                 dprintk(1, "buffer preparation failed: %d\n", ret);
1273         vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED;
1274
1275         return ret;
1276 }
1277
1278 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1279 {
1280         struct vb2_buffer *vb;
1281         int ret;
1282
1283         vb = q->bufs[index];
1284         if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1285                 dprintk(1, "invalid buffer state %d\n",
1286                         vb->state);
1287                 return -EINVAL;
1288         }
1289
1290         ret = __buf_prepare(vb, pb);
1291         if (ret)
1292                 return ret;
1293
1294         /* Fill buffer information for the userspace */
1295         call_void_bufop(q, fill_user_buffer, vb, pb);
1296
1297         dprintk(1, "prepare of buffer %d succeeded\n", vb->index);
1298
1299         return ret;
1300 }
1301 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1302
1303 /**
1304  * vb2_start_streaming() - Attempt to start streaming.
1305  * @q:          videobuf2 queue
1306  *
1307  * Attempt to start streaming. When this function is called there must be
1308  * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1309  * number of buffers required for the DMA engine to function). If the
1310  * @start_streaming op fails it is supposed to return all the driver-owned
1311  * buffers back to vb2 in state QUEUED. Check if that happened and if
1312  * not warn and reclaim them forcefully.
1313  */
1314 static int vb2_start_streaming(struct vb2_queue *q)
1315 {
1316         struct vb2_buffer *vb;
1317         int ret;
1318
1319         /*
1320          * If any buffers were queued before streamon,
1321          * we can now pass them to driver for processing.
1322          */
1323         list_for_each_entry(vb, &q->queued_list, queued_entry)
1324                 __enqueue_in_driver(vb);
1325
1326         /* Tell the driver to start streaming */
1327         q->start_streaming_called = 1;
1328         ret = call_qop(q, start_streaming, q,
1329                        atomic_read(&q->owned_by_drv_count));
1330         if (!ret)
1331                 return 0;
1332
1333         q->start_streaming_called = 0;
1334
1335         dprintk(1, "driver refused to start streaming\n");
1336         /*
1337          * If you see this warning, then the driver isn't cleaning up properly
1338          * after a failed start_streaming(). See the start_streaming()
1339          * documentation in videobuf2-core.h for more information how buffers
1340          * should be returned to vb2 in start_streaming().
1341          */
1342         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1343                 unsigned i;
1344
1345                 /*
1346                  * Forcefully reclaim buffers if the driver did not
1347                  * correctly return them to vb2.
1348                  */
1349                 for (i = 0; i < q->num_buffers; ++i) {
1350                         vb = q->bufs[i];
1351                         if (vb->state == VB2_BUF_STATE_ACTIVE)
1352                                 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1353                 }
1354                 /* Must be zero now */
1355                 WARN_ON(atomic_read(&q->owned_by_drv_count));
1356         }
1357         /*
1358          * If done_list is not empty, then start_streaming() didn't call
1359          * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1360          * STATE_DONE.
1361          */
1362         WARN_ON(!list_empty(&q->done_list));
1363         return ret;
1364 }
1365
1366 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
1367 {
1368         struct vb2_buffer *vb;
1369         int ret;
1370
1371         vb = q->bufs[index];
1372
1373         switch (vb->state) {
1374         case VB2_BUF_STATE_DEQUEUED:
1375                 ret = __buf_prepare(vb, pb);
1376                 if (ret)
1377                         return ret;
1378                 break;
1379         case VB2_BUF_STATE_PREPARED:
1380                 break;
1381         case VB2_BUF_STATE_PREPARING:
1382                 dprintk(1, "buffer still being prepared\n");
1383                 return -EINVAL;
1384         default:
1385                 dprintk(1, "invalid buffer state %d\n", vb->state);
1386                 return -EINVAL;
1387         }
1388
1389         /*
1390          * Add to the queued buffers list, a buffer will stay on it until
1391          * dequeued in dqbuf.
1392          */
1393         list_add_tail(&vb->queued_entry, &q->queued_list);
1394         q->queued_count++;
1395         q->waiting_for_buffers = false;
1396         vb->state = VB2_BUF_STATE_QUEUED;
1397
1398         if (pb)
1399                 call_void_bufop(q, copy_timestamp, vb, pb);
1400
1401         trace_vb2_qbuf(q, vb);
1402
1403         /*
1404          * If already streaming, give the buffer to driver for processing.
1405          * If not, the buffer will be given to driver on next streamon.
1406          */
1407         if (q->start_streaming_called)
1408                 __enqueue_in_driver(vb);
1409
1410         /* Fill buffer information for the userspace */
1411         if (pb)
1412                 call_void_bufop(q, fill_user_buffer, vb, pb);
1413
1414         /*
1415          * If streamon has been called, and we haven't yet called
1416          * start_streaming() since not enough buffers were queued, and
1417          * we now have reached the minimum number of queued buffers,
1418          * then we can finally call start_streaming().
1419          */
1420         if (q->streaming && !q->start_streaming_called &&
1421             q->queued_count >= q->min_buffers_needed) {
1422                 ret = vb2_start_streaming(q);
1423                 if (ret)
1424                         return ret;
1425         }
1426
1427         dprintk(1, "qbuf of buffer %d succeeded\n", vb->index);
1428         return 0;
1429 }
1430 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1431
1432 /**
1433  * __vb2_wait_for_done_vb() - wait for a buffer to become available
1434  * for dequeuing
1435  *
1436  * Will sleep if required for nonblocking == false.
1437  */
1438 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1439 {
1440         /*
1441          * All operations on vb_done_list are performed under done_lock
1442          * spinlock protection. However, buffers may be removed from
1443          * it and returned to userspace only while holding both driver's
1444          * lock and the done_lock spinlock. Thus we can be sure that as
1445          * long as we hold the driver's lock, the list will remain not
1446          * empty if list_empty() check succeeds.
1447          */
1448
1449         for (;;) {
1450                 int ret;
1451
1452                 if (!q->streaming) {
1453                         dprintk(1, "streaming off, will not wait for buffers\n");
1454                         return -EINVAL;
1455                 }
1456
1457                 if (q->error) {
1458                         dprintk(1, "Queue in error state, will not wait for buffers\n");
1459                         return -EIO;
1460                 }
1461
1462                 if (q->last_buffer_dequeued) {
1463                         dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1464                         return -EPIPE;
1465                 }
1466
1467                 if (!list_empty(&q->done_list)) {
1468                         /*
1469                          * Found a buffer that we were waiting for.
1470                          */
1471                         break;
1472                 }
1473
1474                 if (nonblocking) {
1475                         dprintk(1, "nonblocking and no buffers to dequeue, will not wait\n");
1476                         return -EAGAIN;
1477                 }
1478
1479                 /*
1480                  * We are streaming and blocking, wait for another buffer to
1481                  * become ready or for streamoff. Driver's lock is released to
1482                  * allow streamoff or qbuf to be called while waiting.
1483                  */
1484                 call_void_qop(q, wait_prepare, q);
1485
1486                 /*
1487                  * All locks have been released, it is safe to sleep now.
1488                  */
1489                 dprintk(3, "will sleep waiting for buffers\n");
1490                 ret = wait_event_interruptible(q->done_wq,
1491                                 !list_empty(&q->done_list) || !q->streaming ||
1492                                 q->error);
1493
1494                 /*
1495                  * We need to reevaluate both conditions again after reacquiring
1496                  * the locks or return an error if one occurred.
1497                  */
1498                 call_void_qop(q, wait_finish, q);
1499                 if (ret) {
1500                         dprintk(1, "sleep was interrupted\n");
1501                         return ret;
1502                 }
1503         }
1504         return 0;
1505 }
1506
1507 /**
1508  * __vb2_get_done_vb() - get a buffer ready for dequeuing
1509  *
1510  * Will sleep if required for nonblocking == false.
1511  */
1512 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1513                              void *pb, int nonblocking)
1514 {
1515         unsigned long flags;
1516         int ret = 0;
1517
1518         /*
1519          * Wait for at least one buffer to become available on the done_list.
1520          */
1521         ret = __vb2_wait_for_done_vb(q, nonblocking);
1522         if (ret)
1523                 return ret;
1524
1525         /*
1526          * Driver's lock has been held since we last verified that done_list
1527          * is not empty, so no need for another list_empty(done_list) check.
1528          */
1529         spin_lock_irqsave(&q->done_lock, flags);
1530         *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1531         /*
1532          * Only remove the buffer from done_list if all planes can be
1533          * handled. Some cases such as V4L2 file I/O and DVB have pb
1534          * == NULL; skip the check then as there's nothing to verify.
1535          */
1536         if (pb)
1537                 ret = call_bufop(q, verify_planes_array, *vb, pb);
1538         if (!ret)
1539                 list_del(&(*vb)->done_entry);
1540         spin_unlock_irqrestore(&q->done_lock, flags);
1541
1542         return ret;
1543 }
1544
1545 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1546 {
1547         if (!q->streaming) {
1548                 dprintk(1, "streaming off, will not wait for buffers\n");
1549                 return -EINVAL;
1550         }
1551
1552         if (q->start_streaming_called)
1553                 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1554         return 0;
1555 }
1556 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1557
1558 /**
1559  * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1560  */
1561 static void __vb2_dqbuf(struct vb2_buffer *vb)
1562 {
1563         struct vb2_queue *q = vb->vb2_queue;
1564         unsigned int i;
1565
1566         /* nothing to do if the buffer is already dequeued */
1567         if (vb->state == VB2_BUF_STATE_DEQUEUED)
1568                 return;
1569
1570         vb->state = VB2_BUF_STATE_DEQUEUED;
1571
1572         /* unmap DMABUF buffer */
1573         if (q->memory == VB2_MEMORY_DMABUF)
1574                 for (i = 0; i < vb->num_planes; ++i) {
1575                         if (!vb->planes[i].dbuf_mapped)
1576                                 continue;
1577                         call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
1578                         vb->planes[i].dbuf_mapped = 0;
1579                 }
1580 }
1581
1582 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1583                    bool nonblocking)
1584 {
1585         struct vb2_buffer *vb = NULL;
1586         int ret;
1587
1588         ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1589         if (ret < 0)
1590                 return ret;
1591
1592         switch (vb->state) {
1593         case VB2_BUF_STATE_DONE:
1594                 dprintk(3, "returning done buffer\n");
1595                 break;
1596         case VB2_BUF_STATE_ERROR:
1597                 dprintk(3, "returning done buffer with errors\n");
1598                 break;
1599         default:
1600                 dprintk(1, "invalid buffer state\n");
1601                 return -EINVAL;
1602         }
1603
1604         call_void_vb_qop(vb, buf_finish, vb);
1605
1606         if (pindex)
1607                 *pindex = vb->index;
1608
1609         /* Fill buffer information for the userspace */
1610         if (pb)
1611                 call_void_bufop(q, fill_user_buffer, vb, pb);
1612
1613         /* Remove from videobuf queue */
1614         list_del(&vb->queued_entry);
1615         q->queued_count--;
1616
1617         trace_vb2_dqbuf(q, vb);
1618
1619         /* go back to dequeued state */
1620         __vb2_dqbuf(vb);
1621
1622         dprintk(1, "dqbuf of buffer %d, with state %d\n",
1623                         vb->index, vb->state);
1624
1625         return 0;
1626
1627 }
1628 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
1629
1630 /**
1631  * __vb2_queue_cancel() - cancel and stop (pause) streaming
1632  *
1633  * Removes all queued buffers from driver's queue and all buffers queued by
1634  * userspace from videobuf's queue. Returns to state after reqbufs.
1635  */
1636 static void __vb2_queue_cancel(struct vb2_queue *q)
1637 {
1638         unsigned int i;
1639
1640         /*
1641          * Tell driver to stop all transactions and release all queued
1642          * buffers.
1643          */
1644         if (q->start_streaming_called)
1645                 call_void_qop(q, stop_streaming, q);
1646
1647         /*
1648          * If you see this warning, then the driver isn't cleaning up properly
1649          * in stop_streaming(). See the stop_streaming() documentation in
1650          * videobuf2-core.h for more information how buffers should be returned
1651          * to vb2 in stop_streaming().
1652          */
1653         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1654                 for (i = 0; i < q->num_buffers; ++i)
1655                         if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
1656                                 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
1657                 /* Must be zero now */
1658                 WARN_ON(atomic_read(&q->owned_by_drv_count));
1659         }
1660
1661         q->streaming = 0;
1662         q->start_streaming_called = 0;
1663         q->queued_count = 0;
1664         q->error = 0;
1665
1666         /*
1667          * Remove all buffers from videobuf's list...
1668          */
1669         INIT_LIST_HEAD(&q->queued_list);
1670         /*
1671          * ...and done list; userspace will not receive any buffers it
1672          * has not already dequeued before initiating cancel.
1673          */
1674         INIT_LIST_HEAD(&q->done_list);
1675         atomic_set(&q->owned_by_drv_count, 0);
1676         wake_up_all(&q->done_wq);
1677
1678         /*
1679          * Reinitialize all buffers for next use.
1680          * Make sure to call buf_finish for any queued buffers. Normally
1681          * that's done in dqbuf, but that's not going to happen when we
1682          * cancel the whole queue. Note: this code belongs here, not in
1683          * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
1684          * call to __fill_user_buffer() after buf_finish(). That order can't
1685          * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
1686          */
1687         for (i = 0; i < q->num_buffers; ++i) {
1688                 struct vb2_buffer *vb = q->bufs[i];
1689
1690                 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1691                         vb->state = VB2_BUF_STATE_PREPARED;
1692                         call_void_vb_qop(vb, buf_finish, vb);
1693                 }
1694                 __vb2_dqbuf(vb);
1695         }
1696 }
1697
1698 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
1699 {
1700         int ret;
1701
1702         if (type != q->type) {
1703                 dprintk(1, "invalid stream type\n");
1704                 return -EINVAL;
1705         }
1706
1707         if (q->streaming) {
1708                 dprintk(3, "already streaming\n");
1709                 return 0;
1710         }
1711
1712         if (!q->num_buffers) {
1713                 dprintk(1, "no buffers have been allocated\n");
1714                 return -EINVAL;
1715         }
1716
1717         if (q->num_buffers < q->min_buffers_needed) {
1718                 dprintk(1, "need at least %u allocated buffers\n",
1719                                 q->min_buffers_needed);
1720                 return -EINVAL;
1721         }
1722
1723         /*
1724          * Tell driver to start streaming provided sufficient buffers
1725          * are available.
1726          */
1727         if (q->queued_count >= q->min_buffers_needed) {
1728                 ret = v4l_vb2q_enable_media_source(q);
1729                 if (ret)
1730                         return ret;
1731                 ret = vb2_start_streaming(q);
1732                 if (ret) {
1733                         __vb2_queue_cancel(q);
1734                         return ret;
1735                 }
1736         }
1737
1738         q->streaming = 1;
1739
1740         dprintk(3, "successful\n");
1741         return 0;
1742 }
1743 EXPORT_SYMBOL_GPL(vb2_core_streamon);
1744
1745 void vb2_queue_error(struct vb2_queue *q)
1746 {
1747         q->error = 1;
1748
1749         wake_up_all(&q->done_wq);
1750 }
1751 EXPORT_SYMBOL_GPL(vb2_queue_error);
1752
1753 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
1754 {
1755         if (type != q->type) {
1756                 dprintk(1, "invalid stream type\n");
1757                 return -EINVAL;
1758         }
1759
1760         /*
1761          * Cancel will pause streaming and remove all buffers from the driver
1762          * and videobuf, effectively returning control over them to userspace.
1763          *
1764          * Note that we do this even if q->streaming == 0: if you prepare or
1765          * queue buffers, and then call streamoff without ever having called
1766          * streamon, you would still expect those buffers to be returned to
1767          * their normal dequeued state.
1768          */
1769         __vb2_queue_cancel(q);
1770         q->waiting_for_buffers = !q->is_output;
1771         q->last_buffer_dequeued = false;
1772
1773         dprintk(3, "successful\n");
1774         return 0;
1775 }
1776 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
1777
1778 /**
1779  * __find_plane_by_offset() - find plane associated with the given offset off
1780  */
1781 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
1782                         unsigned int *_buffer, unsigned int *_plane)
1783 {
1784         struct vb2_buffer *vb;
1785         unsigned int buffer, plane;
1786
1787         /*
1788          * Go over all buffers and their planes, comparing the given offset
1789          * with an offset assigned to each plane. If a match is found,
1790          * return its buffer and plane numbers.
1791          */
1792         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
1793                 vb = q->bufs[buffer];
1794
1795                 for (plane = 0; plane < vb->num_planes; ++plane) {
1796                         if (vb->planes[plane].m.offset == off) {
1797                                 *_buffer = buffer;
1798                                 *_plane = plane;
1799                                 return 0;
1800                         }
1801                 }
1802         }
1803
1804         return -EINVAL;
1805 }
1806
1807 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
1808                 unsigned int index, unsigned int plane, unsigned int flags)
1809 {
1810         struct vb2_buffer *vb = NULL;
1811         struct vb2_plane *vb_plane;
1812         int ret;
1813         struct dma_buf *dbuf;
1814
1815         if (q->memory != VB2_MEMORY_MMAP) {
1816                 dprintk(1, "queue is not currently set up for mmap\n");
1817                 return -EINVAL;
1818         }
1819
1820         if (!q->mem_ops->get_dmabuf) {
1821                 dprintk(1, "queue does not support DMA buffer exporting\n");
1822                 return -EINVAL;
1823         }
1824
1825         if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
1826                 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
1827                 return -EINVAL;
1828         }
1829
1830         if (type != q->type) {
1831                 dprintk(1, "invalid buffer type\n");
1832                 return -EINVAL;
1833         }
1834
1835         if (index >= q->num_buffers) {
1836                 dprintk(1, "buffer index out of range\n");
1837                 return -EINVAL;
1838         }
1839
1840         vb = q->bufs[index];
1841
1842         if (plane >= vb->num_planes) {
1843                 dprintk(1, "buffer plane out of range\n");
1844                 return -EINVAL;
1845         }
1846
1847         if (vb2_fileio_is_active(q)) {
1848                 dprintk(1, "expbuf: file io in progress\n");
1849                 return -EBUSY;
1850         }
1851
1852         vb_plane = &vb->planes[plane];
1853
1854         dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv,
1855                                 flags & O_ACCMODE);
1856         if (IS_ERR_OR_NULL(dbuf)) {
1857                 dprintk(1, "failed to export buffer %d, plane %d\n",
1858                         index, plane);
1859                 return -EINVAL;
1860         }
1861
1862         ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
1863         if (ret < 0) {
1864                 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
1865                         index, plane, ret);
1866                 dma_buf_put(dbuf);
1867                 return ret;
1868         }
1869
1870         dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
1871                 index, plane, ret);
1872         *fd = ret;
1873
1874         return 0;
1875 }
1876 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
1877
1878 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
1879 {
1880         unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
1881         struct vb2_buffer *vb;
1882         unsigned int buffer = 0, plane = 0;
1883         int ret;
1884         unsigned long length;
1885
1886         if (q->memory != VB2_MEMORY_MMAP) {
1887                 dprintk(1, "queue is not currently set up for mmap\n");
1888                 return -EINVAL;
1889         }
1890
1891         /*
1892          * Check memory area access mode.
1893          */
1894         if (!(vma->vm_flags & VM_SHARED)) {
1895                 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
1896                 return -EINVAL;
1897         }
1898         if (q->is_output) {
1899                 if (!(vma->vm_flags & VM_WRITE)) {
1900                         dprintk(1, "invalid vma flags, VM_WRITE needed\n");
1901                         return -EINVAL;
1902                 }
1903         } else {
1904                 if (!(vma->vm_flags & VM_READ)) {
1905                         dprintk(1, "invalid vma flags, VM_READ needed\n");
1906                         return -EINVAL;
1907                 }
1908         }
1909         if (vb2_fileio_is_active(q)) {
1910                 dprintk(1, "mmap: file io in progress\n");
1911                 return -EBUSY;
1912         }
1913
1914         /*
1915          * Find the plane corresponding to the offset passed by userspace.
1916          */
1917         ret = __find_plane_by_offset(q, off, &buffer, &plane);
1918         if (ret)
1919                 return ret;
1920
1921         vb = q->bufs[buffer];
1922
1923         /*
1924          * MMAP requires page_aligned buffers.
1925          * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
1926          * so, we need to do the same here.
1927          */
1928         length = PAGE_ALIGN(vb->planes[plane].length);
1929         if (length < (vma->vm_end - vma->vm_start)) {
1930                 dprintk(1,
1931                         "MMAP invalid, as it would overflow buffer length\n");
1932                 return -EINVAL;
1933         }
1934
1935         mutex_lock(&q->mmap_lock);
1936         ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
1937         mutex_unlock(&q->mmap_lock);
1938         if (ret)
1939                 return ret;
1940
1941         dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
1942         return 0;
1943 }
1944 EXPORT_SYMBOL_GPL(vb2_mmap);
1945
1946 #ifndef CONFIG_MMU
1947 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
1948                                     unsigned long addr,
1949                                     unsigned long len,
1950                                     unsigned long pgoff,
1951                                     unsigned long flags)
1952 {
1953         unsigned long off = pgoff << PAGE_SHIFT;
1954         struct vb2_buffer *vb;
1955         unsigned int buffer, plane;
1956         void *vaddr;
1957         int ret;
1958
1959         if (q->memory != VB2_MEMORY_MMAP) {
1960                 dprintk(1, "queue is not currently set up for mmap\n");
1961                 return -EINVAL;
1962         }
1963
1964         /*
1965          * Find the plane corresponding to the offset passed by userspace.
1966          */
1967         ret = __find_plane_by_offset(q, off, &buffer, &plane);
1968         if (ret)
1969                 return ret;
1970
1971         vb = q->bufs[buffer];
1972
1973         vaddr = vb2_plane_vaddr(vb, plane);
1974         return vaddr ? (unsigned long)vaddr : -EINVAL;
1975 }
1976 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
1977 #endif
1978
1979 int vb2_core_queue_init(struct vb2_queue *q)
1980 {
1981         /*
1982          * Sanity check
1983          */
1984         if (WARN_ON(!q)                   ||
1985             WARN_ON(!q->ops)              ||
1986             WARN_ON(!q->mem_ops)          ||
1987             WARN_ON(!q->type)             ||
1988             WARN_ON(!q->io_modes)         ||
1989             WARN_ON(!q->ops->queue_setup) ||
1990             WARN_ON(!q->ops->buf_queue))
1991                 return -EINVAL;
1992
1993         INIT_LIST_HEAD(&q->queued_list);
1994         INIT_LIST_HEAD(&q->done_list);
1995         spin_lock_init(&q->done_lock);
1996         mutex_init(&q->mmap_lock);
1997         init_waitqueue_head(&q->done_wq);
1998
1999         if (q->buf_struct_size == 0)
2000                 q->buf_struct_size = sizeof(struct vb2_buffer);
2001
2002         return 0;
2003 }
2004 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2005
2006 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2007 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2008 void vb2_core_queue_release(struct vb2_queue *q)
2009 {
2010         __vb2_cleanup_fileio(q);
2011         __vb2_queue_cancel(q);
2012         mutex_lock(&q->mmap_lock);
2013         __vb2_queue_free(q, q->num_buffers);
2014         mutex_unlock(&q->mmap_lock);
2015 }
2016 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2017
2018 unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file,
2019                 poll_table *wait)
2020 {
2021         unsigned long req_events = poll_requested_events(wait);
2022         struct vb2_buffer *vb = NULL;
2023         unsigned long flags;
2024
2025         if (!q->is_output && !(req_events & (POLLIN | POLLRDNORM)))
2026                 return 0;
2027         if (q->is_output && !(req_events & (POLLOUT | POLLWRNORM)))
2028                 return 0;
2029
2030         /*
2031          * Start file I/O emulator only if streaming API has not been used yet.
2032          */
2033         if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2034                 if (!q->is_output && (q->io_modes & VB2_READ) &&
2035                                 (req_events & (POLLIN | POLLRDNORM))) {
2036                         if (__vb2_init_fileio(q, 1))
2037                                 return POLLERR;
2038                 }
2039                 if (q->is_output && (q->io_modes & VB2_WRITE) &&
2040                                 (req_events & (POLLOUT | POLLWRNORM))) {
2041                         if (__vb2_init_fileio(q, 0))
2042                                 return POLLERR;
2043                         /*
2044                          * Write to OUTPUT queue can be done immediately.
2045                          */
2046                         return POLLOUT | POLLWRNORM;
2047                 }
2048         }
2049
2050         /*
2051          * There is nothing to wait for if the queue isn't streaming, or if the
2052          * error flag is set.
2053          */
2054         if (!vb2_is_streaming(q) || q->error)
2055                 return POLLERR;
2056
2057         /*
2058          * If this quirk is set and QBUF hasn't been called yet then
2059          * return POLLERR as well. This only affects capture queues, output
2060          * queues will always initialize waiting_for_buffers to false.
2061          * This quirk is set by V4L2 for backwards compatibility reasons.
2062          */
2063         if (q->quirk_poll_must_check_waiting_for_buffers &&
2064             q->waiting_for_buffers && (req_events & (POLLIN | POLLRDNORM)))
2065                 return POLLERR;
2066
2067         /*
2068          * For output streams you can call write() as long as there are fewer
2069          * buffers queued than there are buffers available.
2070          */
2071         if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2072                 return POLLOUT | POLLWRNORM;
2073
2074         if (list_empty(&q->done_list)) {
2075                 /*
2076                  * If the last buffer was dequeued from a capture queue,
2077                  * return immediately. DQBUF will return -EPIPE.
2078                  */
2079                 if (q->last_buffer_dequeued)
2080                         return POLLIN | POLLRDNORM;
2081
2082                 poll_wait(file, &q->done_wq, wait);
2083         }
2084
2085         /*
2086          * Take first buffer available for dequeuing.
2087          */
2088         spin_lock_irqsave(&q->done_lock, flags);
2089         if (!list_empty(&q->done_list))
2090                 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2091                                         done_entry);
2092         spin_unlock_irqrestore(&q->done_lock, flags);
2093
2094         if (vb && (vb->state == VB2_BUF_STATE_DONE
2095                         || vb->state == VB2_BUF_STATE_ERROR)) {
2096                 return (q->is_output) ?
2097                                 POLLOUT | POLLWRNORM :
2098                                 POLLIN | POLLRDNORM;
2099         }
2100         return 0;
2101 }
2102 EXPORT_SYMBOL_GPL(vb2_core_poll);
2103
2104 /**
2105  * struct vb2_fileio_buf - buffer context used by file io emulator
2106  *
2107  * vb2 provides a compatibility layer and emulator of file io (read and
2108  * write) calls on top of streaming API. This structure is used for
2109  * tracking context related to the buffers.
2110  */
2111 struct vb2_fileio_buf {
2112         void *vaddr;
2113         unsigned int size;
2114         unsigned int pos;
2115         unsigned int queued:1;
2116 };
2117
2118 /**
2119  * struct vb2_fileio_data - queue context used by file io emulator
2120  *
2121  * @cur_index:  the index of the buffer currently being read from or
2122  *              written to. If equal to q->num_buffers then a new buffer
2123  *              must be dequeued.
2124  * @initial_index: in the read() case all buffers are queued up immediately
2125  *              in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2126  *              buffers. However, in the write() case no buffers are initially
2127  *              queued, instead whenever a buffer is full it is queued up by
2128  *              __vb2_perform_fileio(). Only once all available buffers have
2129  *              been queued up will __vb2_perform_fileio() start to dequeue
2130  *              buffers. This means that initially __vb2_perform_fileio()
2131  *              needs to know what buffer index to use when it is queuing up
2132  *              the buffers for the first time. That initial index is stored
2133  *              in this field. Once it is equal to q->num_buffers all
2134  *              available buffers have been queued and __vb2_perform_fileio()
2135  *              should start the normal dequeue/queue cycle.
2136  *
2137  * vb2 provides a compatibility layer and emulator of file io (read and
2138  * write) calls on top of streaming API. For proper operation it required
2139  * this structure to save the driver state between each call of the read
2140  * or write function.
2141  */
2142 struct vb2_fileio_data {
2143         unsigned int count;
2144         unsigned int type;
2145         unsigned int memory;
2146         struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2147         unsigned int cur_index;
2148         unsigned int initial_index;
2149         unsigned int q_count;
2150         unsigned int dq_count;
2151         unsigned read_once:1;
2152         unsigned write_immediately:1;
2153 };
2154
2155 /**
2156  * __vb2_init_fileio() - initialize file io emulator
2157  * @q:          videobuf2 queue
2158  * @read:       mode selector (1 means read, 0 means write)
2159  */
2160 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2161 {
2162         struct vb2_fileio_data *fileio;
2163         int i, ret;
2164         unsigned int count = 0;
2165
2166         /*
2167          * Sanity check
2168          */
2169         if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2170                     (!read && !(q->io_modes & VB2_WRITE))))
2171                 return -EINVAL;
2172
2173         /*
2174          * Check if device supports mapping buffers to kernel virtual space.
2175          */
2176         if (!q->mem_ops->vaddr)
2177                 return -EBUSY;
2178
2179         /*
2180          * Check if streaming api has not been already activated.
2181          */
2182         if (q->streaming || q->num_buffers > 0)
2183                 return -EBUSY;
2184
2185         /*
2186          * Start with count 1, driver can increase it in queue_setup()
2187          */
2188         count = 1;
2189
2190         dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2191                 (read) ? "read" : "write", count, q->fileio_read_once,
2192                 q->fileio_write_immediately);
2193
2194         fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2195         if (fileio == NULL)
2196                 return -ENOMEM;
2197
2198         fileio->read_once = q->fileio_read_once;
2199         fileio->write_immediately = q->fileio_write_immediately;
2200
2201         /*
2202          * Request buffers and use MMAP type to force driver
2203          * to allocate buffers by itself.
2204          */
2205         fileio->count = count;
2206         fileio->memory = VB2_MEMORY_MMAP;
2207         fileio->type = q->type;
2208         q->fileio = fileio;
2209         ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2210         if (ret)
2211                 goto err_kfree;
2212
2213         /*
2214          * Check if plane_count is correct
2215          * (multiplane buffers are not supported).
2216          */
2217         if (q->bufs[0]->num_planes != 1) {
2218                 ret = -EBUSY;
2219                 goto err_reqbufs;
2220         }
2221
2222         /*
2223          * Get kernel address of each buffer.
2224          */
2225         for (i = 0; i < q->num_buffers; i++) {
2226                 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2227                 if (fileio->bufs[i].vaddr == NULL) {
2228                         ret = -EINVAL;
2229                         goto err_reqbufs;
2230                 }
2231                 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2232         }
2233
2234         /*
2235          * Read mode requires pre queuing of all buffers.
2236          */
2237         if (read) {
2238                 /*
2239                  * Queue all buffers.
2240                  */
2241                 for (i = 0; i < q->num_buffers; i++) {
2242                         ret = vb2_core_qbuf(q, i, NULL);
2243                         if (ret)
2244                                 goto err_reqbufs;
2245                         fileio->bufs[i].queued = 1;
2246                 }
2247                 /*
2248                  * All buffers have been queued, so mark that by setting
2249                  * initial_index to q->num_buffers
2250                  */
2251                 fileio->initial_index = q->num_buffers;
2252                 fileio->cur_index = q->num_buffers;
2253         }
2254
2255         /*
2256          * Start streaming.
2257          */
2258         ret = vb2_core_streamon(q, q->type);
2259         if (ret)
2260                 goto err_reqbufs;
2261
2262         return ret;
2263
2264 err_reqbufs:
2265         fileio->count = 0;
2266         vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2267
2268 err_kfree:
2269         q->fileio = NULL;
2270         kfree(fileio);
2271         return ret;
2272 }
2273
2274 /**
2275  * __vb2_cleanup_fileio() - free resourced used by file io emulator
2276  * @q:          videobuf2 queue
2277  */
2278 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2279 {
2280         struct vb2_fileio_data *fileio = q->fileio;
2281
2282         if (fileio) {
2283                 vb2_core_streamoff(q, q->type);
2284                 q->fileio = NULL;
2285                 fileio->count = 0;
2286                 vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2287                 kfree(fileio);
2288                 dprintk(3, "file io emulator closed\n");
2289         }
2290         return 0;
2291 }
2292
2293 /**
2294  * __vb2_perform_fileio() - perform a single file io (read or write) operation
2295  * @q:          videobuf2 queue
2296  * @data:       pointed to target userspace buffer
2297  * @count:      number of bytes to read or write
2298  * @ppos:       file handle position tracking pointer
2299  * @nonblock:   mode selector (1 means blocking calls, 0 means nonblocking)
2300  * @read:       access mode selector (1 means read, 0 means write)
2301  */
2302 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2303                 loff_t *ppos, int nonblock, int read)
2304 {
2305         struct vb2_fileio_data *fileio;
2306         struct vb2_fileio_buf *buf;
2307         bool is_multiplanar = q->is_multiplanar;
2308         /*
2309          * When using write() to write data to an output video node the vb2 core
2310          * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2311          * else is able to provide this information with the write() operation.
2312          */
2313         bool copy_timestamp = !read && q->copy_timestamp;
2314         unsigned index;
2315         int ret;
2316
2317         dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2318                 read ? "read" : "write", (long)*ppos, count,
2319                 nonblock ? "non" : "");
2320
2321         if (!data)
2322                 return -EINVAL;
2323
2324         /*
2325          * Initialize emulator on first call.
2326          */
2327         if (!vb2_fileio_is_active(q)) {
2328                 ret = __vb2_init_fileio(q, read);
2329                 dprintk(3, "vb2_init_fileio result: %d\n", ret);
2330                 if (ret)
2331                         return ret;
2332         }
2333         fileio = q->fileio;
2334
2335         /*
2336          * Check if we need to dequeue the buffer.
2337          */
2338         index = fileio->cur_index;
2339         if (index >= q->num_buffers) {
2340                 struct vb2_buffer *b;
2341
2342                 /*
2343                  * Call vb2_dqbuf to get buffer back.
2344                  */
2345                 ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2346                 dprintk(5, "vb2_dqbuf result: %d\n", ret);
2347                 if (ret)
2348                         return ret;
2349                 fileio->dq_count += 1;
2350
2351                 fileio->cur_index = index;
2352                 buf = &fileio->bufs[index];
2353                 b = q->bufs[index];
2354
2355                 /*
2356                  * Get number of bytes filled by the driver
2357                  */
2358                 buf->pos = 0;
2359                 buf->queued = 0;
2360                 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2361                                  : vb2_plane_size(q->bufs[index], 0);
2362                 /* Compensate for data_offset on read in the multiplanar case. */
2363                 if (is_multiplanar && read &&
2364                                 b->planes[0].data_offset < buf->size) {
2365                         buf->pos = b->planes[0].data_offset;
2366                         buf->size -= buf->pos;
2367                 }
2368         } else {
2369                 buf = &fileio->bufs[index];
2370         }
2371
2372         /*
2373          * Limit count on last few bytes of the buffer.
2374          */
2375         if (buf->pos + count > buf->size) {
2376                 count = buf->size - buf->pos;
2377                 dprintk(5, "reducing read count: %zd\n", count);
2378         }
2379
2380         /*
2381          * Transfer data to userspace.
2382          */
2383         dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
2384                 count, index, buf->pos);
2385         if (read)
2386                 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2387         else
2388                 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2389         if (ret) {
2390                 dprintk(3, "error copying data\n");
2391                 return -EFAULT;
2392         }
2393
2394         /*
2395          * Update counters.
2396          */
2397         buf->pos += count;
2398         *ppos += count;
2399
2400         /*
2401          * Queue next buffer if required.
2402          */
2403         if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2404                 struct vb2_buffer *b = q->bufs[index];
2405
2406                 /*
2407                  * Check if this is the last buffer to read.
2408                  */
2409                 if (read && fileio->read_once && fileio->dq_count == 1) {
2410                         dprintk(3, "read limit reached\n");
2411                         return __vb2_cleanup_fileio(q);
2412                 }
2413
2414                 /*
2415                  * Call vb2_qbuf and give buffer to the driver.
2416                  */
2417                 b->planes[0].bytesused = buf->pos;
2418
2419                 if (copy_timestamp)
2420                         b->timestamp = ktime_get_ns();
2421                 ret = vb2_core_qbuf(q, index, NULL);
2422                 dprintk(5, "vb2_dbuf result: %d\n", ret);
2423                 if (ret)
2424                         return ret;
2425
2426                 /*
2427                  * Buffer has been queued, update the status
2428                  */
2429                 buf->pos = 0;
2430                 buf->queued = 1;
2431                 buf->size = vb2_plane_size(q->bufs[index], 0);
2432                 fileio->q_count += 1;
2433                 /*
2434                  * If we are queuing up buffers for the first time, then
2435                  * increase initial_index by one.
2436                  */
2437                 if (fileio->initial_index < q->num_buffers)
2438                         fileio->initial_index++;
2439                 /*
2440                  * The next buffer to use is either a buffer that's going to be
2441                  * queued for the first time (initial_index < q->num_buffers)
2442                  * or it is equal to q->num_buffers, meaning that the next
2443                  * time we need to dequeue a buffer since we've now queued up
2444                  * all the 'first time' buffers.
2445                  */
2446                 fileio->cur_index = fileio->initial_index;
2447         }
2448
2449         /*
2450          * Return proper number of bytes processed.
2451          */
2452         if (ret == 0)
2453                 ret = count;
2454         return ret;
2455 }
2456
2457 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2458                 loff_t *ppos, int nonblocking)
2459 {
2460         return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2461 }
2462 EXPORT_SYMBOL_GPL(vb2_read);
2463
2464 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2465                 loff_t *ppos, int nonblocking)
2466 {
2467         return __vb2_perform_fileio(q, (char __user *) data, count,
2468                                                         ppos, nonblocking, 0);
2469 }
2470 EXPORT_SYMBOL_GPL(vb2_write);
2471
2472 struct vb2_threadio_data {
2473         struct task_struct *thread;
2474         vb2_thread_fnc fnc;
2475         void *priv;
2476         bool stop;
2477 };
2478
2479 static int vb2_thread(void *data)
2480 {
2481         struct vb2_queue *q = data;
2482         struct vb2_threadio_data *threadio = q->threadio;
2483         bool copy_timestamp = false;
2484         unsigned prequeue = 0;
2485         unsigned index = 0;
2486         int ret = 0;
2487
2488         if (q->is_output) {
2489                 prequeue = q->num_buffers;
2490                 copy_timestamp = q->copy_timestamp;
2491         }
2492
2493         set_freezable();
2494
2495         for (;;) {
2496                 struct vb2_buffer *vb;
2497
2498                 /*
2499                  * Call vb2_dqbuf to get buffer back.
2500                  */
2501                 if (prequeue) {
2502                         vb = q->bufs[index++];
2503                         prequeue--;
2504                 } else {
2505                         call_void_qop(q, wait_finish, q);
2506                         if (!threadio->stop)
2507                                 ret = vb2_core_dqbuf(q, &index, NULL, 0);
2508                         call_void_qop(q, wait_prepare, q);
2509                         dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
2510                         if (!ret)
2511                                 vb = q->bufs[index];
2512                 }
2513                 if (ret || threadio->stop)
2514                         break;
2515                 try_to_freeze();
2516
2517                 if (vb->state != VB2_BUF_STATE_ERROR)
2518                         if (threadio->fnc(vb, threadio->priv))
2519                                 break;
2520                 call_void_qop(q, wait_finish, q);
2521                 if (copy_timestamp)
2522                         vb->timestamp = ktime_get_ns();;
2523                 if (!threadio->stop)
2524                         ret = vb2_core_qbuf(q, vb->index, NULL);
2525                 call_void_qop(q, wait_prepare, q);
2526                 if (ret || threadio->stop)
2527                         break;
2528         }
2529
2530         /* Hmm, linux becomes *very* unhappy without this ... */
2531         while (!kthread_should_stop()) {
2532                 set_current_state(TASK_INTERRUPTIBLE);
2533                 schedule();
2534         }
2535         return 0;
2536 }
2537
2538 /*
2539  * This function should not be used for anything else but the videobuf2-dvb
2540  * support. If you think you have another good use-case for this, then please
2541  * contact the linux-media mailinglist first.
2542  */
2543 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
2544                      const char *thread_name)
2545 {
2546         struct vb2_threadio_data *threadio;
2547         int ret = 0;
2548
2549         if (q->threadio)
2550                 return -EBUSY;
2551         if (vb2_is_busy(q))
2552                 return -EBUSY;
2553         if (WARN_ON(q->fileio))
2554                 return -EBUSY;
2555
2556         threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
2557         if (threadio == NULL)
2558                 return -ENOMEM;
2559         threadio->fnc = fnc;
2560         threadio->priv = priv;
2561
2562         ret = __vb2_init_fileio(q, !q->is_output);
2563         dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
2564         if (ret)
2565                 goto nomem;
2566         q->threadio = threadio;
2567         threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
2568         if (IS_ERR(threadio->thread)) {
2569                 ret = PTR_ERR(threadio->thread);
2570                 threadio->thread = NULL;
2571                 goto nothread;
2572         }
2573         return 0;
2574
2575 nothread:
2576         __vb2_cleanup_fileio(q);
2577 nomem:
2578         kfree(threadio);
2579         return ret;
2580 }
2581 EXPORT_SYMBOL_GPL(vb2_thread_start);
2582
2583 int vb2_thread_stop(struct vb2_queue *q)
2584 {
2585         struct vb2_threadio_data *threadio = q->threadio;
2586         int err;
2587
2588         if (threadio == NULL)
2589                 return 0;
2590         threadio->stop = true;
2591         /* Wake up all pending sleeps in the thread */
2592         vb2_queue_error(q);
2593         err = kthread_stop(threadio->thread);
2594         __vb2_cleanup_fileio(q);
2595         threadio->thread = NULL;
2596         kfree(threadio);
2597         q->threadio = NULL;
2598         return err;
2599 }
2600 EXPORT_SYMBOL_GPL(vb2_thread_stop);
2601
2602 MODULE_DESCRIPTION("Media buffer core framework");
2603 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2604 MODULE_LICENSE("GPL");