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         void *mem_priv;
 198         int plane;
 199         int ret = -ENOMEM;
 200
 201         /*
 202          * Allocate memory for all planes in this buffer
 203          * NOTE: mmapped areas should be page aligned
 204          */
 205         for (plane = 0; plane < vb->num_planes; ++plane) {
 206                 unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
 207
 208                 mem_priv = call_ptr_memop(vb, alloc,
 209                                 q->alloc_devs[plane] ? : q->dev,
 210                                 q->dma_attrs, size, q->dma_dir, q->gfp_flags);
 211                 if (IS_ERR_OR_NULL(mem_priv)) {
 212                         if (mem_priv)
 213                                 ret = PTR_ERR(mem_priv);
 214                         goto free;
 215                 }
 216
 217                 /* Associate allocator private data with this plane */
 218                 vb->planes[plane].mem_priv = mem_priv;
 219         }
 220
 221         return 0;
 222 free:
 223         /* Free already allocated memory if one of the allocations failed */
 224         for (; plane > 0; --plane) {
 225                 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
 226                 vb->planes[plane - 1].mem_priv = NULL;
 227         }
 228
 229         return ret;
 230 }
 231
 232 /*
 233  * __vb2_buf_mem_free() - free memory of the given buffer
 234  */
 235 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
 236 {
 237         unsigned int plane;
 238
 239         for (plane = 0; plane < vb->num_planes; ++plane) {
 240                 call_void_memop(vb, put, vb->planes[plane].mem_priv);
 241                 vb->planes[plane].mem_priv = NULL;
 242                 dprintk(3, "freed plane %d of buffer %d\n", plane, vb->index);
 243         }
 244 }
 245
 246 /*
 247  * __vb2_buf_userptr_put() - release userspace memory associated with
 248  * a USERPTR buffer
 249  */
 250 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
 251 {
 252         unsigned int plane;
 253
 254         for (plane = 0; plane < vb->num_planes; ++plane) {
 255                 if (vb->planes[plane].mem_priv)
 256                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
 257                 vb->planes[plane].mem_priv = NULL;
 258         }
 259 }
 260
 261 /*
 262  * __vb2_plane_dmabuf_put() - release memory associated with
 263  * a DMABUF shared plane
 264  */
 265 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
 266 {
 267         if (!p->mem_priv)
 268                 return;
 269
 270         if (p->dbuf_mapped)
 271                 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
 272
 273         call_void_memop(vb, detach_dmabuf, p->mem_priv);
 274         dma_buf_put(p->dbuf);
 275         p->mem_priv = NULL;
 276         p->dbuf = NULL;
 277         p->dbuf_mapped = 0;
 278 }
 279
 280 /*
 281  * __vb2_buf_dmabuf_put() - release memory associated with
 282  * a DMABUF shared buffer
 283  */
 284 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
 285 {
 286         unsigned int plane;
 287
 288         for (plane = 0; plane < vb->num_planes; ++plane)
 289                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
 290 }
 291
 292 /*
 293  * __setup_offsets() - setup unique offsets ("cookies") for every plane in
 294  * the buffer.
 295  */
 296 static void __setup_offsets(struct vb2_buffer *vb)
 297 {
 298         struct vb2_queue *q = vb->vb2_queue;
 299         unsigned int plane;
 300         unsigned long off = 0;
 301
 302         if (vb->index) {
 303                 struct vb2_buffer *prev = q->bufs[vb->index - 1];
 304                 struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
 305
 306                 off = PAGE_ALIGN(p->m.offset + p->length);
 307         }
 308
 309         for (plane = 0; plane < vb->num_planes; ++plane) {
 310                 vb->planes[plane].m.offset = off;
 311
 312                 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
 313                                 vb->index, plane, off);
 314
 315                 off += vb->planes[plane].length;
 316                 off = PAGE_ALIGN(off);
 317         }
 318 }
 319
 320 /*
 321  * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
 322  * video buffer memory for all buffers/planes on the queue and initializes the
 323  * queue
 324  *
 325  * Returns the number of buffers successfully allocated.
 326  */
 327 static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
 328                              unsigned int num_buffers, unsigned int num_planes,
 329                              const unsigned plane_sizes[VB2_MAX_PLANES])
 330 {
 331         unsigned int buffer, plane;
 332         struct vb2_buffer *vb;
 333         int ret;
 334
 335         for (buffer = 0; buffer < num_buffers; ++buffer) {
 336                 /* Allocate videobuf buffer structures */
 337                 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
 338                 if (!vb) {
 339                         dprintk(1, "memory alloc for buffer struct failed\n");
 340                         break;
 341                 }
 342
 343                 vb->state = VB2_BUF_STATE_DEQUEUED;
 344                 vb->vb2_queue = q;
 345                 vb->num_planes = num_planes;
 346                 vb->index = q->num_buffers + buffer;
 347                 vb->type = q->type;
 348                 vb->memory = memory;
 349                 for (plane = 0; plane < num_planes; ++plane) {
 350                         vb->planes[plane].length = plane_sizes[plane];
 351                         vb->planes[plane].min_length = plane_sizes[plane];
 352                 }
 353                 q->bufs[vb->index] = vb;
 354
 355                 /* Allocate video buffer memory for the MMAP type */
 356                 if (memory == VB2_MEMORY_MMAP) {
 357                         ret = __vb2_buf_mem_alloc(vb);
 358                         if (ret) {
 359                                 dprintk(1, "failed allocating memory for buffer %d\n",
 360                                         buffer);
 361                                 q->bufs[vb->index] = NULL;
 362                                 kfree(vb);
 363                                 break;
 364                         }
 365                         __setup_offsets(vb);
 366                         /*
 367                          * Call the driver-provided buffer initialization
 368                          * callback, if given. An error in initialization
 369                          * results in queue setup failure.
 370                          */
 371                         ret = call_vb_qop(vb, buf_init, vb);
 372                         if (ret) {
 373                                 dprintk(1, "buffer %d %p initialization failed\n",
 374                                         buffer, vb);
 375                                 __vb2_buf_mem_free(vb);
 376                                 q->bufs[vb->index] = NULL;
 377                                 kfree(vb);
 378                                 break;
 379                         }
 380                 }
 381         }
 382
 383         dprintk(1, "allocated %d buffers, %d plane(s) each\n",
 384                         buffer, num_planes);
 385
 386         return buffer;
 387 }
 388
 389 /*
 390  * __vb2_free_mem() - release all video buffer memory for a given queue
 391  */
 392 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
 393 {
 394         unsigned int buffer;
 395         struct vb2_buffer *vb;
 396
 397         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 398              ++buffer) {
 399                 vb = q->bufs[buffer];
 400                 if (!vb)
 401                         continue;
 402
 403                 /* Free MMAP buffers or release USERPTR buffers */
 404                 if (q->memory == VB2_MEMORY_MMAP)
 405                         __vb2_buf_mem_free(vb);
 406                 else if (q->memory == VB2_MEMORY_DMABUF)
 407                         __vb2_buf_dmabuf_put(vb);
 408                 else
 409                         __vb2_buf_userptr_put(vb);
 410         }
 411 }
 412
 413 /*
 414  * __vb2_queue_free() - free buffers at the end of the queue - video memory and
 415  * related information, if no buffers are left return the queue to an
 416  * uninitialized state. Might be called even if the queue has already been freed.
 417  */
 418 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
 419 {
 420         unsigned int buffer;
 421
 422         /*
 423          * Sanity check: when preparing a buffer the queue lock is released for
 424          * a short while (see __buf_prepare for the details), which would allow
 425          * a race with a reqbufs which can call this function. Removing the
 426          * buffers from underneath __buf_prepare is obviously a bad idea, so we
 427          * check if any of the buffers is in the state PREPARING, and if so we
 428          * just return -EAGAIN.
 429          */
 430         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 431              ++buffer) {
 432                 if (q->bufs[buffer] == NULL)
 433                         continue;
 434                 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
 435                         dprintk(1, "preparing buffers, cannot free\n");
 436                         return -EAGAIN;
 437                 }
 438         }
 439
 440         /* Call driver-provided cleanup function for each buffer, if provided */
 441         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 442              ++buffer) {
 443                 struct vb2_buffer *vb = q->bufs[buffer];
 444
 445                 if (vb && vb->planes[0].mem_priv)
 446                         call_void_vb_qop(vb, buf_cleanup, vb);
 447         }
 448
 449         /* Release video buffer memory */
 450         __vb2_free_mem(q, buffers);
 451
 452 #ifdef CONFIG_VIDEO_ADV_DEBUG
 453         /*
 454          * Check that all the calls were balances during the life-time of this
 455          * queue. If not (or if the debug level is 1 or up), then dump the
 456          * counters to the kernel log.
 457          */
 458         if (q->num_buffers) {
 459                 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
 460                                   q->cnt_wait_prepare != q->cnt_wait_finish;
 461
 462                 if (unbalanced || debug) {
 463                         pr_info("vb2: counters for queue %p:%s\n", q,
 464                                 unbalanced ? " UNBALANCED!" : "");
 465                         pr_info("vb2:     setup: %u start_streaming: %u stop_streaming: %u\n",
 466                                 q->cnt_queue_setup, q->cnt_start_streaming,
 467                                 q->cnt_stop_streaming);
 468                         pr_info("vb2:     wait_prepare: %u wait_finish: %u\n",
 469                                 q->cnt_wait_prepare, q->cnt_wait_finish);
 470                 }
 471                 q->cnt_queue_setup = 0;
 472                 q->cnt_wait_prepare = 0;
 473                 q->cnt_wait_finish = 0;
 474                 q->cnt_start_streaming = 0;
 475                 q->cnt_stop_streaming = 0;
 476         }
 477         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 478                 struct vb2_buffer *vb = q->bufs[buffer];
 479                 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
 480                                   vb->cnt_mem_prepare != vb->cnt_mem_finish ||
 481                                   vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
 482                                   vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
 483                                   vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
 484                                   vb->cnt_buf_queue != vb->cnt_buf_done ||
 485                                   vb->cnt_buf_prepare != vb->cnt_buf_finish ||
 486                                   vb->cnt_buf_init != vb->cnt_buf_cleanup;
 487
 488                 if (unbalanced || debug) {
 489                         pr_info("vb2:   counters for queue %p, buffer %d:%s\n",
 490                                 q, buffer, unbalanced ? " UNBALANCED!" : "");
 491                         pr_info("vb2:     buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
 492                                 vb->cnt_buf_init, vb->cnt_buf_cleanup,
 493                                 vb->cnt_buf_prepare, vb->cnt_buf_finish);
 494                         pr_info("vb2:     buf_queue: %u buf_done: %u\n",
 495                                 vb->cnt_buf_queue, vb->cnt_buf_done);
 496                         pr_info("vb2:     alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
 497                                 vb->cnt_mem_alloc, vb->cnt_mem_put,
 498                                 vb->cnt_mem_prepare, vb->cnt_mem_finish,
 499                                 vb->cnt_mem_mmap);
 500                         pr_info("vb2:     get_userptr: %u put_userptr: %u\n",
 501                                 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
 502                         pr_info("vb2:     attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
 503                                 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
 504                                 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
 505                         pr_info("vb2:     get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
 506                                 vb->cnt_mem_get_dmabuf,
 507                                 vb->cnt_mem_num_users,
 508                                 vb->cnt_mem_vaddr,
 509                                 vb->cnt_mem_cookie);
 510                 }
 511         }
 512 #endif
 513
 514         /* Free videobuf buffers */
 515         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 516              ++buffer) {
 517                 kfree(q->bufs[buffer]);
 518                 q->bufs[buffer] = NULL;
 519         }
 520
 521         q->num_buffers -= buffers;
 522         if (!q->num_buffers) {
 523                 q->memory = 0;
 524                 INIT_LIST_HEAD(&q->queued_list);
 525         }
 526         return 0;
 527 }
 528
 529 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
 530 {
 531         unsigned int plane;
 532         for (plane = 0; plane < vb->num_planes; ++plane) {
 533                 void *mem_priv = vb->planes[plane].mem_priv;
 534                 /*
 535                  * If num_users() has not been provided, call_memop
 536                  * will return 0, apparently nobody cares about this
 537                  * case anyway. If num_users() returns more than 1,
 538                  * we are not the only user of the plane's memory.
 539                  */
 540                 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
 541                         return true;
 542         }
 543         return false;
 544 }
 545 EXPORT_SYMBOL(vb2_buffer_in_use);
 546
 547 /*
 548  * __buffers_in_use() - return true if any buffers on the queue are in use and
 549  * the queue cannot be freed (by the means of REQBUFS(0)) call
 550  */
 551 static bool __buffers_in_use(struct vb2_queue *q)
 552 {
 553         unsigned int buffer;
 554         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 555                 if (vb2_buffer_in_use(q, q->bufs[buffer]))
 556                         return true;
 557         }
 558         return false;
 559 }
 560
 561 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
 562 {
 563         call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
 564 }
 565 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
 566
 567 /*
 568  * __verify_userptr_ops() - verify that all memory operations required for
 569  * USERPTR queue type have been provided
 570  */
 571 static int __verify_userptr_ops(struct vb2_queue *q)
 572 {
 573         if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
 574             !q->mem_ops->put_userptr)
 575                 return -EINVAL;
 576
 577         return 0;
 578 }
 579
 580 /*
 581  * __verify_mmap_ops() - verify that all memory operations required for
 582  * MMAP queue type have been provided
 583  */
 584 static int __verify_mmap_ops(struct vb2_queue *q)
 585 {
 586         if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
 587             !q->mem_ops->put || !q->mem_ops->mmap)
 588                 return -EINVAL;
 589
 590         return 0;
 591 }
 592
 593 /*
 594  * __verify_dmabuf_ops() - verify that all memory operations required for
 595  * DMABUF queue type have been provided
 596  */
 597 static int __verify_dmabuf_ops(struct vb2_queue *q)
 598 {
 599         if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
 600             !q->mem_ops->detach_dmabuf  || !q->mem_ops->map_dmabuf ||
 601             !q->mem_ops->unmap_dmabuf)
 602                 return -EINVAL;
 603
 604         return 0;
 605 }
 606
 607 int vb2_verify_memory_type(struct vb2_queue *q,
 608                 enum vb2_memory memory, unsigned int type)
 609 {
 610         if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
 611             memory != VB2_MEMORY_DMABUF) {
 612                 dprintk(1, "unsupported memory type\n");
 613                 return -EINVAL;
 614         }
 615
 616         if (type != q->type) {
 617                 dprintk(1, "requested type is incorrect\n");
 618                 return -EINVAL;
 619         }
 620
 621         /*
 622          * Make sure all the required memory ops for given memory type
 623          * are available.
 624          */
 625         if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
 626                 dprintk(1, "MMAP for current setup unsupported\n");
 627                 return -EINVAL;
 628         }
 629
 630         if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
 631                 dprintk(1, "USERPTR for current setup unsupported\n");
 632                 return -EINVAL;
 633         }
 634
 635         if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
 636                 dprintk(1, "DMABUF for current setup unsupported\n");
 637                 return -EINVAL;
 638         }
 639
 640         /*
 641          * Place the busy tests at the end: -EBUSY can be ignored when
 642          * create_bufs is called with count == 0, but count == 0 should still
 643          * do the memory and type validation.
 644          */
 645         if (vb2_fileio_is_active(q)) {
 646                 dprintk(1, "file io in progress\n");
 647                 return -EBUSY;
 648         }
 649         return 0;
 650 }
 651 EXPORT_SYMBOL(vb2_verify_memory_type);
 652
 653 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 654                 unsigned int *count)
 655 {
 656         unsigned int num_buffers, allocated_buffers, num_planes = 0;
 657         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 658         int ret;
 659
 660         if (q->streaming) {
 661                 dprintk(1, "streaming active\n");
 662                 return -EBUSY;
 663         }
 664
 665         if (*count == 0 || q->num_buffers != 0 || q->memory != memory) {
 666                 /*
 667                  * We already have buffers allocated, so first check if they
 668                  * are not in use and can be freed.
 669                  */
 670                 mutex_lock(&q->mmap_lock);
 671                 if (q->memory == VB2_MEMORY_MMAP && __buffers_in_use(q)) {
 672                         mutex_unlock(&q->mmap_lock);
 673                         dprintk(1, "memory in use, cannot free\n");
 674                         return -EBUSY;
 675                 }
 676
 677                 /*
 678                  * Call queue_cancel to clean up any buffers in the PREPARED or
 679                  * QUEUED state which is possible if buffers were prepared or
 680                  * queued without ever calling STREAMON.
 681                  */
 682                 __vb2_queue_cancel(q);
 683                 ret = __vb2_queue_free(q, q->num_buffers);
 684                 mutex_unlock(&q->mmap_lock);
 685                 if (ret)
 686                         return ret;
 687
 688                 /*
 689                  * In case of REQBUFS(0) return immediately without calling
 690                  * driver's queue_setup() callback and allocating resources.
 691                  */
 692                 if (*count == 0)
 693                         return 0;
 694         }
 695
 696         /*
 697          * Make sure the requested values and current defaults are sane.
 698          */
 699         num_buffers = min_t(unsigned int, *count, VB2_MAX_FRAME);
 700         num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
 701         memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 702         q->memory = memory;
 703
 704         /*
 705          * Ask the driver how many buffers and planes per buffer it requires.
 706          * Driver also sets the size and allocator context for each plane.
 707          */
 708         ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
 709                        plane_sizes, q->alloc_devs);
 710         if (ret)
 711                 return ret;
 712
 713         /* Finally, allocate buffers and video memory */
 714         allocated_buffers =
 715                 __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
 716         if (allocated_buffers == 0) {
 717                 dprintk(1, "memory allocation failed\n");
 718                 return -ENOMEM;
 719         }
 720
 721         /*
 722          * There is no point in continuing if we can't allocate the minimum
 723          * number of buffers needed by this vb2_queue.
 724          */
 725         if (allocated_buffers < q->min_buffers_needed)
 726                 ret = -ENOMEM;
 727
 728         /*
 729          * Check if driver can handle the allocated number of buffers.
 730          */
 731         if (!ret && allocated_buffers < num_buffers) {
 732                 num_buffers = allocated_buffers;
 733                 /*
 734                  * num_planes is set by the previous queue_setup(), but since it
 735                  * signals to queue_setup() whether it is called from create_bufs()
 736                  * vs reqbufs() we zero it here to signal that queue_setup() is
 737                  * called for the reqbufs() case.
 738                  */
 739                 num_planes = 0;
 740
 741                 ret = call_qop(q, queue_setup, q, &num_buffers,
 742                                &num_planes, plane_sizes, q->alloc_devs);
 743
 744                 if (!ret && allocated_buffers < num_buffers)
 745                         ret = -ENOMEM;
 746
 747                 /*
 748                  * Either the driver has accepted a smaller number of buffers,
 749                  * or .queue_setup() returned an error
 750                  */
 751         }
 752
 753         mutex_lock(&q->mmap_lock);
 754         q->num_buffers = allocated_buffers;
 755
 756         if (ret < 0) {
 757                 /*
 758                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 759                  * from q->num_buffers.
 760                  */
 761                 __vb2_queue_free(q, allocated_buffers);
 762                 mutex_unlock(&q->mmap_lock);
 763                 return ret;
 764         }
 765         mutex_unlock(&q->mmap_lock);
 766
 767         /*
 768          * Return the number of successfully allocated buffers
 769          * to the userspace.
 770          */
 771         *count = allocated_buffers;
 772         q->waiting_for_buffers = !q->is_output;
 773
 774         return 0;
 775 }
 776 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
 777
 778 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 779                 unsigned int *count, unsigned requested_planes,
 780                 const unsigned requested_sizes[])
 781 {
 782         unsigned int num_planes = 0, num_buffers, allocated_buffers;
 783         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 784         int ret;
 785
 786         if (q->num_buffers == VB2_MAX_FRAME) {
 787                 dprintk(1, "maximum number of buffers already allocated\n");
 788                 return -ENOBUFS;
 789         }
 790
 791         if (!q->num_buffers) {
 792                 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 793                 q->memory = memory;
 794                 q->waiting_for_buffers = !q->is_output;
 795         }
 796
 797         num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
 798
 799         if (requested_planes && requested_sizes) {
 800                 num_planes = requested_planes;
 801                 memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
 802         }
 803
 804         /*
 805          * Ask the driver, whether the requested number of buffers, planes per
 806          * buffer and their sizes are acceptable
 807          */
 808         ret = call_qop(q, queue_setup, q, &num_buffers,
 809                        &num_planes, plane_sizes, q->alloc_devs);
 810         if (ret)
 811                 return ret;
 812
 813         /* Finally, allocate buffers and video memory */
 814         allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
 815                                 num_planes, plane_sizes);
 816         if (allocated_buffers == 0) {
 817                 dprintk(1, "memory allocation failed\n");
 818                 return -ENOMEM;
 819         }
 820
 821         /*
 822          * Check if driver can handle the so far allocated number of buffers.
 823          */
 824         if (allocated_buffers < num_buffers) {
 825                 num_buffers = allocated_buffers;
 826
 827                 /*
 828                  * q->num_buffers contains the total number of buffers, that the
 829                  * queue driver has set up
 830                  */
 831                 ret = call_qop(q, queue_setup, q, &num_buffers,
 832                                &num_planes, plane_sizes, q->alloc_devs);
 833
 834                 if (!ret && allocated_buffers < num_buffers)
 835                         ret = -ENOMEM;
 836
 837                 /*
 838                  * Either the driver has accepted a smaller number of buffers,
 839                  * or .queue_setup() returned an error
 840                  */
 841         }
 842
 843         mutex_lock(&q->mmap_lock);
 844         q->num_buffers += allocated_buffers;
 845
 846         if (ret < 0) {
 847                 /*
 848                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 849                  * from q->num_buffers.
 850                  */
 851                 __vb2_queue_free(q, allocated_buffers);
 852                 mutex_unlock(&q->mmap_lock);
 853                 return -ENOMEM;
 854         }
 855         mutex_unlock(&q->mmap_lock);
 856
 857         /*
 858          * Return the number of successfully allocated buffers
 859          * to the userspace.
 860          */
 861         *count = allocated_buffers;
 862
 863         return 0;
 864 }
 865 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
 866
 867 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
 868 {
 869         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
 870                 return NULL;
 871
 872         return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
 873
 874 }
 875 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
 876
 877 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
 878 {
 879         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
 880                 return NULL;
 881
 882         return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
 883 }
 884 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
 885
 886 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
 887 {
 888         struct vb2_queue *q = vb->vb2_queue;
 889         unsigned long flags;
 890         unsigned int plane;
 891
 892         if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
 893                 return;
 894
 895         if (WARN_ON(state != VB2_BUF_STATE_DONE &&
 896                     state != VB2_BUF_STATE_ERROR &&
 897                     state != VB2_BUF_STATE_QUEUED &&
 898                     state != VB2_BUF_STATE_REQUEUEING))
 899                 state = VB2_BUF_STATE_ERROR;
 900
 901 #ifdef CONFIG_VIDEO_ADV_DEBUG
 902         /*
 903          * Although this is not a callback, it still does have to balance
 904          * with the buf_queue op. So update this counter manually.
 905          */
 906         vb->cnt_buf_done++;
 907 #endif
 908         dprintk(4, "done processing on buffer %d, state: %d\n",
 909                         vb->index, state);
 910
 911         /* sync buffers */
 912         for (plane = 0; plane < vb->num_planes; ++plane)
 913                 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
 914
 915         spin_lock_irqsave(&q->done_lock, flags);
 916         if (state == VB2_BUF_STATE_QUEUED ||
 917             state == VB2_BUF_STATE_REQUEUEING) {
 918                 vb->state = VB2_BUF_STATE_QUEUED;
 919         } else {
 920                 /* Add the buffer to the done buffers list */
 921                 list_add_tail(&vb->done_entry, &q->done_list);
 922                 vb->state = state;
 923         }
 924         atomic_dec(&q->owned_by_drv_count);
 925         spin_unlock_irqrestore(&q->done_lock, flags);
 926
 927         trace_vb2_buf_done(q, vb);
 928
 929         switch (state) {
 930         case VB2_BUF_STATE_QUEUED:
 931                 return;
 932         case VB2_BUF_STATE_REQUEUEING:
 933                 if (q->start_streaming_called)
 934                         __enqueue_in_driver(vb);
 935                 return;
 936         default:
 937                 /* Inform any processes that may be waiting for buffers */
 938                 wake_up(&q->done_wq);
 939                 break;
 940         }
 941 }
 942 EXPORT_SYMBOL_GPL(vb2_buffer_done);
 943
 944 void vb2_discard_done(struct vb2_queue *q)
 945 {
 946         struct vb2_buffer *vb;
 947         unsigned long flags;
 948
 949         spin_lock_irqsave(&q->done_lock, flags);
 950         list_for_each_entry(vb, &q->done_list, done_entry)
 951                 vb->state = VB2_BUF_STATE_ERROR;
 952         spin_unlock_irqrestore(&q->done_lock, flags);
 953 }
 954 EXPORT_SYMBOL_GPL(vb2_discard_done);
 955
 956 /*
 957  * __prepare_mmap() - prepare an MMAP buffer
 958  */
 959 static int __prepare_mmap(struct vb2_buffer *vb, const void *pb)
 960 {
 961         int ret = 0;
 962
 963         if (pb)
 964                 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
 965                                  vb, pb, vb->planes);
 966         return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
 967 }
 968
 969 /*
 970  * __prepare_userptr() - prepare a USERPTR buffer
 971  */
 972 static int __prepare_userptr(struct vb2_buffer *vb, const void *pb)
 973 {
 974         struct vb2_plane planes[VB2_MAX_PLANES];
 975         struct vb2_queue *q = vb->vb2_queue;
 976         void *mem_priv;
 977         unsigned int plane;
 978         int ret = 0;
 979         bool reacquired = vb->planes[0].mem_priv == NULL;
 980
 981         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
 982         /* Copy relevant information provided by the userspace */
 983         if (pb) {
 984                 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
 985                                  vb, pb, planes);
 986                 if (ret)
 987                         return ret;
 988         }
 989
 990         for (plane = 0; plane < vb->num_planes; ++plane) {
 991                 /* Skip the plane if already verified */
 992                 if (vb->planes[plane].m.userptr &&
 993                         vb->planes[plane].m.userptr == planes[plane].m.userptr
 994                         && vb->planes[plane].length == planes[plane].length)
 995                         continue;
 996
 997                 dprintk(3, "userspace address for plane %d changed, reacquiring memory\n",
 998                         plane);
 999
1000                 /* Check if the provided plane buffer is large enough */
1001                 if (planes[plane].length < vb->planes[plane].min_length) {
1002                         dprintk(1, "provided buffer size %u is less than setup size %u for plane %d\n",
1003                                                 planes[plane].length,
1004                                                 vb->planes[plane].min_length,
1005                                                 plane);
1006                         ret = -EINVAL;
1007                         goto err;
1008                 }
1009
1010                 /* Release previously acquired memory if present */
1011                 if (vb->planes[plane].mem_priv) {
1012                         if (!reacquired) {
1013                                 reacquired = true;
1014                                 call_void_vb_qop(vb, buf_cleanup, vb);
1015                         }
1016                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1017                 }
1018
1019                 vb->planes[plane].mem_priv = NULL;
1020                 vb->planes[plane].bytesused = 0;
1021                 vb->planes[plane].length = 0;
1022                 vb->planes[plane].m.userptr = 0;
1023                 vb->planes[plane].data_offset = 0;
1024
1025                 /* Acquire each plane's memory */
1026                 mem_priv = call_ptr_memop(vb, get_userptr,
1027                                 q->alloc_devs[plane] ? : q->dev,
1028                                 planes[plane].m.userptr,
1029                                 planes[plane].length, q->dma_dir);
1030                 if (IS_ERR(mem_priv)) {
1031                         dprintk(1, "failed acquiring userspace memory for plane %d\n",
1032                                 plane);
1033                         ret = PTR_ERR(mem_priv);
1034                         goto err;
1035                 }
1036                 vb->planes[plane].mem_priv = mem_priv;
1037         }
1038
1039         /*
1040          * Now that everything is in order, copy relevant information
1041          * provided by userspace.
1042          */
1043         for (plane = 0; plane < vb->num_planes; ++plane) {
1044                 vb->planes[plane].bytesused = planes[plane].bytesused;
1045                 vb->planes[plane].length = planes[plane].length;
1046                 vb->planes[plane].m.userptr = planes[plane].m.userptr;
1047                 vb->planes[plane].data_offset = planes[plane].data_offset;
1048         }
1049
1050         if (reacquired) {
1051                 /*
1052                  * One or more planes changed, so we must call buf_init to do
1053                  * the driver-specific initialization on the newly acquired
1054                  * buffer, if provided.
1055                  */
1056                 ret = call_vb_qop(vb, buf_init, vb);
1057                 if (ret) {
1058                         dprintk(1, "buffer initialization failed\n");
1059                         goto err;
1060                 }
1061         }
1062
1063         ret = call_vb_qop(vb, buf_prepare, vb);
1064         if (ret) {
1065                 dprintk(1, "buffer preparation failed\n");
1066                 call_void_vb_qop(vb, buf_cleanup, vb);
1067                 goto err;
1068         }
1069
1070         return 0;
1071 err:
1072         /* In case of errors, release planes that were already acquired */
1073         for (plane = 0; plane < vb->num_planes; ++plane) {
1074                 if (vb->planes[plane].mem_priv)
1075                         call_void_memop(vb, put_userptr,
1076                                 vb->planes[plane].mem_priv);
1077                 vb->planes[plane].mem_priv = NULL;
1078                 vb->planes[plane].m.userptr = 0;
1079                 vb->planes[plane].length = 0;
1080         }
1081
1082         return ret;
1083 }
1084
1085 /*
1086  * __prepare_dmabuf() - prepare a DMABUF buffer
1087  */
1088 static int __prepare_dmabuf(struct vb2_buffer *vb, const void *pb)
1089 {
1090         struct vb2_plane planes[VB2_MAX_PLANES];
1091         struct vb2_queue *q = vb->vb2_queue;
1092         void *mem_priv;
1093         unsigned int plane;
1094         int ret = 0;
1095         bool reacquired = vb->planes[0].mem_priv == NULL;
1096
1097         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1098         /* Copy relevant information provided by the userspace */
1099         if (pb) {
1100                 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1101                                  vb, pb, planes);
1102                 if (ret)
1103                         return ret;
1104         }
1105
1106         for (plane = 0; plane < vb->num_planes; ++plane) {
1107                 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1108
1109                 if (IS_ERR_OR_NULL(dbuf)) {
1110                         dprintk(1, "invalid dmabuf fd for plane %d\n",
1111                                 plane);
1112                         ret = -EINVAL;
1113                         goto err;
1114                 }
1115
1116                 /* use DMABUF size if length is not provided */
1117                 if (planes[plane].length == 0)
1118                         planes[plane].length = dbuf->size;
1119
1120                 if (planes[plane].length < vb->planes[plane].min_length) {
1121                         dprintk(1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
1122                                 planes[plane].length, plane,
1123                                 vb->planes[plane].min_length);
1124                         dma_buf_put(dbuf);
1125                         ret = -EINVAL;
1126                         goto err;
1127                 }
1128
1129                 /* Skip the plane if already verified */
1130                 if (dbuf == vb->planes[plane].dbuf &&
1131                         vb->planes[plane].length == planes[plane].length) {
1132                         dma_buf_put(dbuf);
1133                         continue;
1134                 }
1135
1136                 dprintk(3, "buffer for plane %d changed\n", plane);
1137
1138                 if (!reacquired) {
1139                         reacquired = true;
1140                         call_void_vb_qop(vb, buf_cleanup, vb);
1141                 }
1142
1143                 /* Release previously acquired memory if present */
1144                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1145                 vb->planes[plane].bytesused = 0;
1146                 vb->planes[plane].length = 0;
1147                 vb->planes[plane].m.fd = 0;
1148                 vb->planes[plane].data_offset = 0;
1149
1150                 /* Acquire each plane's memory */
1151                 mem_priv = call_ptr_memop(vb, attach_dmabuf,
1152                                 q->alloc_devs[plane] ? : q->dev,
1153                                 dbuf, planes[plane].length, q->dma_dir);
1154                 if (IS_ERR(mem_priv)) {
1155                         dprintk(1, "failed to attach dmabuf\n");
1156                         ret = PTR_ERR(mem_priv);
1157                         dma_buf_put(dbuf);
1158                         goto err;
1159                 }
1160
1161                 vb->planes[plane].dbuf = dbuf;
1162                 vb->planes[plane].mem_priv = mem_priv;
1163         }
1164
1165         /*
1166          * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1167          * here instead just before the DMA, while queueing the buffer(s) so
1168          * userspace knows sooner rather than later if the dma-buf map fails.
1169          */
1170         for (plane = 0; plane < vb->num_planes; ++plane) {
1171                 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1172                 if (ret) {
1173                         dprintk(1, "failed to map dmabuf for plane %d\n",
1174                                 plane);
1175                         goto err;
1176                 }
1177                 vb->planes[plane].dbuf_mapped = 1;
1178         }
1179
1180         /*
1181          * Now that everything is in order, copy relevant information
1182          * provided by userspace.
1183          */
1184         for (plane = 0; plane < vb->num_planes; ++plane) {
1185                 vb->planes[plane].bytesused = planes[plane].bytesused;
1186                 vb->planes[plane].length = planes[plane].length;
1187                 vb->planes[plane].m.fd = planes[plane].m.fd;
1188                 vb->planes[plane].data_offset = planes[plane].data_offset;
1189         }
1190
1191         if (reacquired) {
1192                 /*
1193                  * Call driver-specific initialization on the newly acquired buffer,
1194                  * if provided.
1195                  */
1196                 ret = call_vb_qop(vb, buf_init, vb);
1197                 if (ret) {
1198                         dprintk(1, "buffer initialization failed\n");
1199                         goto err;
1200                 }
1201         }
1202
1203         ret = call_vb_qop(vb, buf_prepare, vb);
1204         if (ret) {
1205                 dprintk(1, "buffer preparation failed\n");
1206                 call_void_vb_qop(vb, buf_cleanup, vb);
1207                 goto err;
1208         }
1209
1210         return 0;
1211 err:
1212         /* In case of errors, release planes that were already acquired */
1213         __vb2_buf_dmabuf_put(vb);
1214
1215         return ret;
1216 }
1217
1218 /*
1219  * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1220  */
1221 static void __enqueue_in_driver(struct vb2_buffer *vb)
1222 {
1223         struct vb2_queue *q = vb->vb2_queue;
1224
1225         vb->state = VB2_BUF_STATE_ACTIVE;
1226         atomic_inc(&q->owned_by_drv_count);
1227
1228         trace_vb2_buf_queue(q, vb);
1229
1230         call_void_vb_qop(vb, buf_queue, vb);
1231 }
1232
1233 static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
1234 {
1235         struct vb2_queue *q = vb->vb2_queue;
1236         unsigned int plane;
1237         int ret;
1238
1239         if (q->error) {
1240                 dprintk(1, "fatal error occurred on queue\n");
1241                 return -EIO;
1242         }
1243
1244         vb->state = VB2_BUF_STATE_PREPARING;
1245
1246         switch (q->memory) {
1247         case VB2_MEMORY_MMAP:
1248                 ret = __prepare_mmap(vb, pb);
1249                 break;
1250         case VB2_MEMORY_USERPTR:
1251                 ret = __prepare_userptr(vb, pb);
1252                 break;
1253         case VB2_MEMORY_DMABUF:
1254                 ret = __prepare_dmabuf(vb, pb);
1255                 break;
1256         default:
1257                 WARN(1, "Invalid queue type\n");
1258                 ret = -EINVAL;
1259         }
1260
1261         if (ret) {
1262                 dprintk(1, "buffer preparation failed: %d\n", ret);
1263                 vb->state = VB2_BUF_STATE_DEQUEUED;
1264                 return ret;
1265         }
1266
1267         /* sync buffers */
1268         for (plane = 0; plane < vb->num_planes; ++plane)
1269                 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1270
1271         vb->state = VB2_BUF_STATE_PREPARED;
1272
1273         return 0;
1274 }
1275
1276 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1277 {
1278         struct vb2_buffer *vb;
1279         int ret;
1280
1281         vb = q->bufs[index];
1282         if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1283                 dprintk(1, "invalid buffer state %d\n",
1284                         vb->state);
1285                 return -EINVAL;
1286         }
1287
1288         ret = __buf_prepare(vb, pb);
1289         if (ret)
1290                 return ret;
1291
1292         /* Fill buffer information for the userspace */
1293         call_void_bufop(q, fill_user_buffer, vb, pb);
1294
1295         dprintk(2, "prepare of buffer %d succeeded\n", vb->index);
1296
1297         return ret;
1298 }
1299 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1300
1301 /*
1302  * vb2_start_streaming() - Attempt to start streaming.
1303  * @q:          videobuf2 queue
1304  *
1305  * Attempt to start streaming. When this function is called there must be
1306  * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1307  * number of buffers required for the DMA engine to function). If the
1308  * @start_streaming op fails it is supposed to return all the driver-owned
1309  * buffers back to vb2 in state QUEUED. Check if that happened and if
1310  * not warn and reclaim them forcefully.
1311  */
1312 static int vb2_start_streaming(struct vb2_queue *q)
1313 {
1314         struct vb2_buffer *vb;
1315         int ret;
1316
1317         /*
1318          * If any buffers were queued before streamon,
1319          * we can now pass them to driver for processing.
1320          */
1321         list_for_each_entry(vb, &q->queued_list, queued_entry)
1322                 __enqueue_in_driver(vb);
1323
1324         /* Tell the driver to start streaming */
1325         q->start_streaming_called = 1;
1326         ret = call_qop(q, start_streaming, q,
1327                        atomic_read(&q->owned_by_drv_count));
1328         if (!ret)
1329                 return 0;
1330
1331         q->start_streaming_called = 0;
1332
1333         dprintk(1, "driver refused to start streaming\n");
1334         /*
1335          * If you see this warning, then the driver isn't cleaning up properly
1336          * after a failed start_streaming(). See the start_streaming()
1337          * documentation in videobuf2-core.h for more information how buffers
1338          * should be returned to vb2 in start_streaming().
1339          */
1340         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1341                 unsigned i;
1342
1343                 /*
1344                  * Forcefully reclaim buffers if the driver did not
1345                  * correctly return them to vb2.
1346                  */
1347                 for (i = 0; i < q->num_buffers; ++i) {
1348                         vb = q->bufs[i];
1349                         if (vb->state == VB2_BUF_STATE_ACTIVE)
1350                                 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1351                 }
1352                 /* Must be zero now */
1353                 WARN_ON(atomic_read(&q->owned_by_drv_count));
1354         }
1355         /*
1356          * If done_list is not empty, then start_streaming() didn't call
1357          * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1358          * STATE_DONE.
1359          */
1360         WARN_ON(!list_empty(&q->done_list));
1361         return ret;
1362 }
1363
1364 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
1365 {
1366         struct vb2_buffer *vb;
1367         int ret;
1368
1369         vb = q->bufs[index];
1370
1371         switch (vb->state) {
1372         case VB2_BUF_STATE_DEQUEUED:
1373                 ret = __buf_prepare(vb, pb);
1374                 if (ret)
1375                         return ret;
1376                 break;
1377         case VB2_BUF_STATE_PREPARED:
1378                 break;
1379         case VB2_BUF_STATE_PREPARING:
1380                 dprintk(1, "buffer still being prepared\n");
1381                 return -EINVAL;
1382         default:
1383                 dprintk(1, "invalid buffer state %d\n", vb->state);
1384                 return -EINVAL;
1385         }
1386
1387         /*
1388          * Add to the queued buffers list, a buffer will stay on it until
1389          * dequeued in dqbuf.
1390          */
1391         list_add_tail(&vb->queued_entry, &q->queued_list);
1392         q->queued_count++;
1393         q->waiting_for_buffers = false;
1394         vb->state = VB2_BUF_STATE_QUEUED;
1395
1396         if (pb)
1397                 call_void_bufop(q, copy_timestamp, vb, pb);
1398
1399         trace_vb2_qbuf(q, vb);
1400
1401         /*
1402          * If already streaming, give the buffer to driver for processing.
1403          * If not, the buffer will be given to driver on next streamon.
1404          */
1405         if (q->start_streaming_called)
1406                 __enqueue_in_driver(vb);
1407
1408         /* Fill buffer information for the userspace */
1409         if (pb)
1410                 call_void_bufop(q, fill_user_buffer, vb, pb);
1411
1412         /*
1413          * If streamon has been called, and we haven't yet called
1414          * start_streaming() since not enough buffers were queued, and
1415          * we now have reached the minimum number of queued buffers,
1416          * then we can finally call start_streaming().
1417          */
1418         if (q->streaming && !q->start_streaming_called &&
1419             q->queued_count >= q->min_buffers_needed) {
1420                 ret = vb2_start_streaming(q);
1421                 if (ret)
1422                         return ret;
1423         }
1424
1425         dprintk(2, "qbuf of buffer %d succeeded\n", vb->index);
1426         return 0;
1427 }
1428 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1429
1430 /*
1431  * __vb2_wait_for_done_vb() - wait for a buffer to become available
1432  * for dequeuing
1433  *
1434  * Will sleep if required for nonblocking == false.
1435  */
1436 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1437 {
1438         /*
1439          * All operations on vb_done_list are performed under done_lock
1440          * spinlock protection. However, buffers may be removed from
1441          * it and returned to userspace only while holding both driver's
1442          * lock and the done_lock spinlock. Thus we can be sure that as
1443          * long as we hold the driver's lock, the list will remain not
1444          * empty if list_empty() check succeeds.
1445          */
1446
1447         for (;;) {
1448                 int ret;
1449
1450                 if (!q->streaming) {
1451                         dprintk(1, "streaming off, will not wait for buffers\n");
1452                         return -EINVAL;
1453                 }
1454
1455                 if (q->error) {
1456                         dprintk(1, "Queue in error state, will not wait for buffers\n");
1457                         return -EIO;
1458                 }
1459
1460                 if (q->last_buffer_dequeued) {
1461                         dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1462                         return -EPIPE;
1463                 }
1464
1465                 if (!list_empty(&q->done_list)) {
1466                         /*
1467                          * Found a buffer that we were waiting for.
1468                          */
1469                         break;
1470                 }
1471
1472                 if (nonblocking) {
1473                         dprintk(3, "nonblocking and no buffers to dequeue, will not wait\n");
1474                         return -EAGAIN;
1475                 }
1476
1477                 /*
1478                  * We are streaming and blocking, wait for another buffer to
1479                  * become ready or for streamoff. Driver's lock is released to
1480                  * allow streamoff or qbuf to be called while waiting.
1481                  */
1482                 call_void_qop(q, wait_prepare, q);
1483
1484                 /*
1485                  * All locks have been released, it is safe to sleep now.
1486                  */
1487                 dprintk(3, "will sleep waiting for buffers\n");
1488                 ret = wait_event_interruptible(q->done_wq,
1489                                 !list_empty(&q->done_list) || !q->streaming ||
1490                                 q->error);
1491
1492                 /*
1493                  * We need to reevaluate both conditions again after reacquiring
1494                  * the locks or return an error if one occurred.
1495                  */
1496                 call_void_qop(q, wait_finish, q);
1497                 if (ret) {
1498                         dprintk(1, "sleep was interrupted\n");
1499                         return ret;
1500                 }
1501         }
1502         return 0;
1503 }
1504
1505 /*
1506  * __vb2_get_done_vb() - get a buffer ready for dequeuing
1507  *
1508  * Will sleep if required for nonblocking == false.
1509  */
1510 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1511                              void *pb, int nonblocking)
1512 {
1513         unsigned long flags;
1514         int ret = 0;
1515
1516         /*
1517          * Wait for at least one buffer to become available on the done_list.
1518          */
1519         ret = __vb2_wait_for_done_vb(q, nonblocking);
1520         if (ret)
1521                 return ret;
1522
1523         /*
1524          * Driver's lock has been held since we last verified that done_list
1525          * is not empty, so no need for another list_empty(done_list) check.
1526          */
1527         spin_lock_irqsave(&q->done_lock, flags);
1528         *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1529         /*
1530          * Only remove the buffer from done_list if all planes can be
1531          * handled. Some cases such as V4L2 file I/O and DVB have pb
1532          * == NULL; skip the check then as there's nothing to verify.
1533          */
1534         if (pb)
1535                 ret = call_bufop(q, verify_planes_array, *vb, pb);
1536         if (!ret)
1537                 list_del(&(*vb)->done_entry);
1538         spin_unlock_irqrestore(&q->done_lock, flags);
1539
1540         return ret;
1541 }
1542
1543 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1544 {
1545         if (!q->streaming) {
1546                 dprintk(1, "streaming off, will not wait for buffers\n");
1547                 return -EINVAL;
1548         }
1549
1550         if (q->start_streaming_called)
1551                 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1552         return 0;
1553 }
1554 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1555
1556 /*
1557  * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1558  */
1559 static void __vb2_dqbuf(struct vb2_buffer *vb)
1560 {
1561         struct vb2_queue *q = vb->vb2_queue;
1562         unsigned int i;
1563
1564         /* nothing to do if the buffer is already dequeued */
1565         if (vb->state == VB2_BUF_STATE_DEQUEUED)
1566                 return;
1567
1568         vb->state = VB2_BUF_STATE_DEQUEUED;
1569
1570         /* unmap DMABUF buffer */
1571         if (q->memory == VB2_MEMORY_DMABUF)
1572                 for (i = 0; i < vb->num_planes; ++i) {
1573                         if (!vb->planes[i].dbuf_mapped)
1574                                 continue;
1575                         call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
1576                         vb->planes[i].dbuf_mapped = 0;
1577                 }
1578 }
1579
1580 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1581                    bool nonblocking)
1582 {
1583         struct vb2_buffer *vb = NULL;
1584         int ret;
1585
1586         ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1587         if (ret < 0)
1588                 return ret;
1589
1590         switch (vb->state) {
1591         case VB2_BUF_STATE_DONE:
1592                 dprintk(3, "returning done buffer\n");
1593                 break;
1594         case VB2_BUF_STATE_ERROR:
1595                 dprintk(3, "returning done buffer with errors\n");
1596                 break;
1597         default:
1598                 dprintk(1, "invalid buffer state\n");
1599                 return -EINVAL;
1600         }
1601
1602         call_void_vb_qop(vb, buf_finish, vb);
1603
1604         if (pindex)
1605                 *pindex = vb->index;
1606
1607         /* Fill buffer information for the userspace */
1608         if (pb)
1609                 call_void_bufop(q, fill_user_buffer, vb, pb);
1610
1611         /* Remove from videobuf queue */
1612         list_del(&vb->queued_entry);
1613         q->queued_count--;
1614
1615         trace_vb2_dqbuf(q, vb);
1616
1617         /* go back to dequeued state */
1618         __vb2_dqbuf(vb);
1619
1620         dprintk(2, "dqbuf of buffer %d, with state %d\n",
1621                         vb->index, vb->state);
1622
1623         return 0;
1624
1625 }
1626 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
1627
1628 /*
1629  * __vb2_queue_cancel() - cancel and stop (pause) streaming
1630  *
1631  * Removes all queued buffers from driver's queue and all buffers queued by
1632  * userspace from videobuf's queue. Returns to state after reqbufs.
1633  */
1634 static void __vb2_queue_cancel(struct vb2_queue *q)
1635 {
1636         unsigned int i;
1637
1638         /*
1639          * Tell driver to stop all transactions and release all queued
1640          * buffers.
1641          */
1642         if (q->start_streaming_called)
1643                 call_void_qop(q, stop_streaming, q);
1644
1645         /*
1646          * If you see this warning, then the driver isn't cleaning up properly
1647          * in stop_streaming(). See the stop_streaming() documentation in
1648          * videobuf2-core.h for more information how buffers should be returned
1649          * to vb2 in stop_streaming().
1650          */
1651         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1652                 for (i = 0; i < q->num_buffers; ++i)
1653                         if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
1654                                 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
1655                 /* Must be zero now */
1656                 WARN_ON(atomic_read(&q->owned_by_drv_count));
1657         }
1658
1659         q->streaming = 0;
1660         q->start_streaming_called = 0;
1661         q->queued_count = 0;
1662         q->error = 0;
1663
1664         /*
1665          * Remove all buffers from videobuf's list...
1666          */
1667         INIT_LIST_HEAD(&q->queued_list);
1668         /*
1669          * ...and done list; userspace will not receive any buffers it
1670          * has not already dequeued before initiating cancel.
1671          */
1672         INIT_LIST_HEAD(&q->done_list);
1673         atomic_set(&q->owned_by_drv_count, 0);
1674         wake_up_all(&q->done_wq);
1675
1676         /*
1677          * Reinitialize all buffers for next use.
1678          * Make sure to call buf_finish for any queued buffers. Normally
1679          * that's done in dqbuf, but that's not going to happen when we
1680          * cancel the whole queue. Note: this code belongs here, not in
1681          * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
1682          * call to __fill_user_buffer() after buf_finish(). That order can't
1683          * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
1684          */
1685         for (i = 0; i < q->num_buffers; ++i) {
1686                 struct vb2_buffer *vb = q->bufs[i];
1687
1688                 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1689                         vb->state = VB2_BUF_STATE_PREPARED;
1690                         call_void_vb_qop(vb, buf_finish, vb);
1691                 }
1692                 __vb2_dqbuf(vb);
1693         }
1694 }
1695
1696 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
1697 {
1698         int ret;
1699
1700         if (type != q->type) {
1701                 dprintk(1, "invalid stream type\n");
1702                 return -EINVAL;
1703         }
1704
1705         if (q->streaming) {
1706                 dprintk(3, "already streaming\n");
1707                 return 0;
1708         }
1709
1710         if (!q->num_buffers) {
1711                 dprintk(1, "no buffers have been allocated\n");
1712                 return -EINVAL;
1713         }
1714
1715         if (q->num_buffers < q->min_buffers_needed) {
1716                 dprintk(1, "need at least %u allocated buffers\n",
1717                                 q->min_buffers_needed);
1718                 return -EINVAL;
1719         }
1720
1721         /*
1722          * Tell driver to start streaming provided sufficient buffers
1723          * are available.
1724          */
1725         if (q->queued_count >= q->min_buffers_needed) {
1726                 ret = v4l_vb2q_enable_media_source(q);
1727                 if (ret)
1728                         return ret;
1729                 ret = vb2_start_streaming(q);
1730                 if (ret) {
1731                         __vb2_queue_cancel(q);
1732                         return ret;
1733                 }
1734         }
1735
1736         q->streaming = 1;
1737
1738         dprintk(3, "successful\n");
1739         return 0;
1740 }
1741 EXPORT_SYMBOL_GPL(vb2_core_streamon);
1742
1743 void vb2_queue_error(struct vb2_queue *q)
1744 {
1745         q->error = 1;
1746
1747         wake_up_all(&q->done_wq);
1748 }
1749 EXPORT_SYMBOL_GPL(vb2_queue_error);
1750
1751 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
1752 {
1753         if (type != q->type) {
1754                 dprintk(1, "invalid stream type\n");
1755                 return -EINVAL;
1756         }
1757
1758         /*
1759          * Cancel will pause streaming and remove all buffers from the driver
1760          * and videobuf, effectively returning control over them to userspace.
1761          *
1762          * Note that we do this even if q->streaming == 0: if you prepare or
1763          * queue buffers, and then call streamoff without ever having called
1764          * streamon, you would still expect those buffers to be returned to
1765          * their normal dequeued state.
1766          */
1767         __vb2_queue_cancel(q);
1768         q->waiting_for_buffers = !q->is_output;
1769         q->last_buffer_dequeued = false;
1770
1771         dprintk(3, "successful\n");
1772         return 0;
1773 }
1774 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
1775
1776 /*
1777  * __find_plane_by_offset() - find plane associated with the given offset off
1778  */
1779 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
1780                         unsigned int *_buffer, unsigned int *_plane)
1781 {
1782         struct vb2_buffer *vb;
1783         unsigned int buffer, plane;
1784
1785         /*
1786          * Go over all buffers and their planes, comparing the given offset
1787          * with an offset assigned to each plane. If a match is found,
1788          * return its buffer and plane numbers.
1789          */
1790         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
1791                 vb = q->bufs[buffer];
1792
1793                 for (plane = 0; plane < vb->num_planes; ++plane) {
1794                         if (vb->planes[plane].m.offset == off) {
1795                                 *_buffer = buffer;
1796                                 *_plane = plane;
1797                                 return 0;
1798                         }
1799                 }
1800         }
1801
1802         return -EINVAL;
1803 }
1804
1805 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
1806                 unsigned int index, unsigned int plane, unsigned int flags)
1807 {
1808         struct vb2_buffer *vb = NULL;
1809         struct vb2_plane *vb_plane;
1810         int ret;
1811         struct dma_buf *dbuf;
1812
1813         if (q->memory != VB2_MEMORY_MMAP) {
1814                 dprintk(1, "queue is not currently set up for mmap\n");
1815                 return -EINVAL;
1816         }
1817
1818         if (!q->mem_ops->get_dmabuf) {
1819                 dprintk(1, "queue does not support DMA buffer exporting\n");
1820                 return -EINVAL;
1821         }
1822
1823         if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
1824                 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
1825                 return -EINVAL;
1826         }
1827
1828         if (type != q->type) {
1829                 dprintk(1, "invalid buffer type\n");
1830                 return -EINVAL;
1831         }
1832
1833         if (index >= q->num_buffers) {
1834                 dprintk(1, "buffer index out of range\n");
1835                 return -EINVAL;
1836         }
1837
1838         vb = q->bufs[index];
1839
1840         if (plane >= vb->num_planes) {
1841                 dprintk(1, "buffer plane out of range\n");
1842                 return -EINVAL;
1843         }
1844
1845         if (vb2_fileio_is_active(q)) {
1846                 dprintk(1, "expbuf: file io in progress\n");
1847                 return -EBUSY;
1848         }
1849
1850         vb_plane = &vb->planes[plane];
1851
1852         dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv,
1853                                 flags & O_ACCMODE);
1854         if (IS_ERR_OR_NULL(dbuf)) {
1855                 dprintk(1, "failed to export buffer %d, plane %d\n",
1856                         index, plane);
1857                 return -EINVAL;
1858         }
1859
1860         ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
1861         if (ret < 0) {
1862                 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
1863                         index, plane, ret);
1864                 dma_buf_put(dbuf);
1865                 return ret;
1866         }
1867
1868         dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
1869                 index, plane, ret);
1870         *fd = ret;
1871
1872         return 0;
1873 }
1874 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
1875
1876 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
1877 {
1878         unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
1879         struct vb2_buffer *vb;
1880         unsigned int buffer = 0, plane = 0;
1881         int ret;
1882         unsigned long length;
1883
1884         if (q->memory != VB2_MEMORY_MMAP) {
1885                 dprintk(1, "queue is not currently set up for mmap\n");
1886                 return -EINVAL;
1887         }
1888
1889         /*
1890          * Check memory area access mode.
1891          */
1892         if (!(vma->vm_flags & VM_SHARED)) {
1893                 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
1894                 return -EINVAL;
1895         }
1896         if (q->is_output) {
1897                 if (!(vma->vm_flags & VM_WRITE)) {
1898                         dprintk(1, "invalid vma flags, VM_WRITE needed\n");
1899                         return -EINVAL;
1900                 }
1901         } else {
1902                 if (!(vma->vm_flags & VM_READ)) {
1903                         dprintk(1, "invalid vma flags, VM_READ needed\n");
1904                         return -EINVAL;
1905                 }
1906         }
1907         if (vb2_fileio_is_active(q)) {
1908                 dprintk(1, "mmap: file io in progress\n");
1909                 return -EBUSY;
1910         }
1911
1912         /*
1913          * Find the plane corresponding to the offset passed by userspace.
1914          */
1915         ret = __find_plane_by_offset(q, off, &buffer, &plane);
1916         if (ret)
1917                 return ret;
1918
1919         vb = q->bufs[buffer];
1920
1921         /*
1922          * MMAP requires page_aligned buffers.
1923          * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
1924          * so, we need to do the same here.
1925          */
1926         length = PAGE_ALIGN(vb->planes[plane].length);
1927         if (length < (vma->vm_end - vma->vm_start)) {
1928                 dprintk(1,
1929                         "MMAP invalid, as it would overflow buffer length\n");
1930                 return -EINVAL;
1931         }
1932
1933         mutex_lock(&q->mmap_lock);
1934         ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
1935         mutex_unlock(&q->mmap_lock);
1936         if (ret)
1937                 return ret;
1938
1939         dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
1940         return 0;
1941 }
1942 EXPORT_SYMBOL_GPL(vb2_mmap);
1943
1944 #ifndef CONFIG_MMU
1945 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
1946                                     unsigned long addr,
1947                                     unsigned long len,
1948                                     unsigned long pgoff,
1949                                     unsigned long flags)
1950 {
1951         unsigned long off = pgoff << PAGE_SHIFT;
1952         struct vb2_buffer *vb;
1953         unsigned int buffer, plane;
1954         void *vaddr;
1955         int ret;
1956
1957         if (q->memory != VB2_MEMORY_MMAP) {
1958                 dprintk(1, "queue is not currently set up for mmap\n");
1959                 return -EINVAL;
1960         }
1961
1962         /*
1963          * Find the plane corresponding to the offset passed by userspace.
1964          */
1965         ret = __find_plane_by_offset(q, off, &buffer, &plane);
1966         if (ret)
1967                 return ret;
1968
1969         vb = q->bufs[buffer];
1970
1971         vaddr = vb2_plane_vaddr(vb, plane);
1972         return vaddr ? (unsigned long)vaddr : -EINVAL;
1973 }
1974 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
1975 #endif
1976
1977 int vb2_core_queue_init(struct vb2_queue *q)
1978 {
1979         /*
1980          * Sanity check
1981          */
1982         if (WARN_ON(!q)                   ||
1983             WARN_ON(!q->ops)              ||
1984             WARN_ON(!q->mem_ops)          ||
1985             WARN_ON(!q->type)             ||
1986             WARN_ON(!q->io_modes)         ||
1987             WARN_ON(!q->ops->queue_setup) ||
1988             WARN_ON(!q->ops->buf_queue))
1989                 return -EINVAL;
1990
1991         INIT_LIST_HEAD(&q->queued_list);
1992         INIT_LIST_HEAD(&q->done_list);
1993         spin_lock_init(&q->done_lock);
1994         mutex_init(&q->mmap_lock);
1995         init_waitqueue_head(&q->done_wq);
1996
1997         if (q->buf_struct_size == 0)
1998                 q->buf_struct_size = sizeof(struct vb2_buffer);
1999
2000         if (q->bidirectional)
2001                 q->dma_dir = DMA_BIDIRECTIONAL;
2002         else
2003                 q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
2004
2005         return 0;
2006 }
2007 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2008
2009 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2010 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2011 void vb2_core_queue_release(struct vb2_queue *q)
2012 {
2013         __vb2_cleanup_fileio(q);
2014         __vb2_queue_cancel(q);
2015         mutex_lock(&q->mmap_lock);
2016         __vb2_queue_free(q, q->num_buffers);
2017         mutex_unlock(&q->mmap_lock);
2018 }
2019 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2020
2021 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
2022                 poll_table *wait)
2023 {
2024         __poll_t req_events = poll_requested_events(wait);
2025         struct vb2_buffer *vb = NULL;
2026         unsigned long flags;
2027
2028         if (!q->is_output && !(req_events & (POLLIN | POLLRDNORM)))
2029                 return 0;
2030         if (q->is_output && !(req_events & (POLLOUT | POLLWRNORM)))
2031                 return 0;
2032
2033         /*
2034          * Start file I/O emulator only if streaming API has not been used yet.
2035          */
2036         if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2037                 if (!q->is_output && (q->io_modes & VB2_READ) &&
2038                                 (req_events & (POLLIN | POLLRDNORM))) {
2039                         if (__vb2_init_fileio(q, 1))
2040                                 return POLLERR;
2041                 }
2042                 if (q->is_output && (q->io_modes & VB2_WRITE) &&
2043                                 (req_events & (POLLOUT | POLLWRNORM))) {
2044                         if (__vb2_init_fileio(q, 0))
2045                                 return POLLERR;
2046                         /*
2047                          * Write to OUTPUT queue can be done immediately.
2048                          */
2049                         return POLLOUT | POLLWRNORM;
2050                 }
2051         }
2052
2053         /*
2054          * There is nothing to wait for if the queue isn't streaming, or if the
2055          * error flag is set.
2056          */
2057         if (!vb2_is_streaming(q) || q->error)
2058                 return POLLERR;
2059
2060         /*
2061          * If this quirk is set and QBUF hasn't been called yet then
2062          * return POLLERR as well. This only affects capture queues, output
2063          * queues will always initialize waiting_for_buffers to false.
2064          * This quirk is set by V4L2 for backwards compatibility reasons.
2065          */
2066         if (q->quirk_poll_must_check_waiting_for_buffers &&
2067             q->waiting_for_buffers && (req_events & (POLLIN | POLLRDNORM)))
2068                 return POLLERR;
2069
2070         /*
2071          * For output streams you can call write() as long as there are fewer
2072          * buffers queued than there are buffers available.
2073          */
2074         if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2075                 return POLLOUT | POLLWRNORM;
2076
2077         if (list_empty(&q->done_list)) {
2078                 /*
2079                  * If the last buffer was dequeued from a capture queue,
2080                  * return immediately. DQBUF will return -EPIPE.
2081                  */
2082                 if (q->last_buffer_dequeued)
2083                         return POLLIN | POLLRDNORM;
2084
2085                 poll_wait(file, &q->done_wq, wait);
2086         }
2087
2088         /*
2089          * Take first buffer available for dequeuing.
2090          */
2091         spin_lock_irqsave(&q->done_lock, flags);
2092         if (!list_empty(&q->done_list))
2093                 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2094                                         done_entry);
2095         spin_unlock_irqrestore(&q->done_lock, flags);
2096
2097         if (vb && (vb->state == VB2_BUF_STATE_DONE
2098                         || vb->state == VB2_BUF_STATE_ERROR)) {
2099                 return (q->is_output) ?
2100                                 POLLOUT | POLLWRNORM :
2101                                 POLLIN | POLLRDNORM;
2102         }
2103         return 0;
2104 }
2105 EXPORT_SYMBOL_GPL(vb2_core_poll);
2106
2107 /*
2108  * struct vb2_fileio_buf - buffer context used by file io emulator
2109  *
2110  * vb2 provides a compatibility layer and emulator of file io (read and
2111  * write) calls on top of streaming API. This structure is used for
2112  * tracking context related to the buffers.
2113  */
2114 struct vb2_fileio_buf {
2115         void *vaddr;
2116         unsigned int size;
2117         unsigned int pos;
2118         unsigned int queued:1;
2119 };
2120
2121 /*
2122  * struct vb2_fileio_data - queue context used by file io emulator
2123  *
2124  * @cur_index:  the index of the buffer currently being read from or
2125  *              written to. If equal to q->num_buffers then a new buffer
2126  *              must be dequeued.
2127  * @initial_index: in the read() case all buffers are queued up immediately
2128  *              in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2129  *              buffers. However, in the write() case no buffers are initially
2130  *              queued, instead whenever a buffer is full it is queued up by
2131  *              __vb2_perform_fileio(). Only once all available buffers have
2132  *              been queued up will __vb2_perform_fileio() start to dequeue
2133  *              buffers. This means that initially __vb2_perform_fileio()
2134  *              needs to know what buffer index to use when it is queuing up
2135  *              the buffers for the first time. That initial index is stored
2136  *              in this field. Once it is equal to q->num_buffers all
2137  *              available buffers have been queued and __vb2_perform_fileio()
2138  *              should start the normal dequeue/queue cycle.
2139  *
2140  * vb2 provides a compatibility layer and emulator of file io (read and
2141  * write) calls on top of streaming API. For proper operation it required
2142  * this structure to save the driver state between each call of the read
2143  * or write function.
2144  */
2145 struct vb2_fileio_data {
2146         unsigned int count;
2147         unsigned int type;
2148         unsigned int memory;
2149         struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2150         unsigned int cur_index;
2151         unsigned int initial_index;
2152         unsigned int q_count;
2153         unsigned int dq_count;
2154         unsigned read_once:1;
2155         unsigned write_immediately:1;
2156 };
2157
2158 /*
2159  * __vb2_init_fileio() - initialize file io emulator
2160  * @q:          videobuf2 queue
2161  * @read:       mode selector (1 means read, 0 means write)
2162  */
2163 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2164 {
2165         struct vb2_fileio_data *fileio;
2166         int i, ret;
2167         unsigned int count = 0;
2168
2169         /*
2170          * Sanity check
2171          */
2172         if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2173                     (!read && !(q->io_modes & VB2_WRITE))))
2174                 return -EINVAL;
2175
2176         /*
2177          * Check if device supports mapping buffers to kernel virtual space.
2178          */
2179         if (!q->mem_ops->vaddr)
2180                 return -EBUSY;
2181
2182         /*
2183          * Check if streaming api has not been already activated.
2184          */
2185         if (q->streaming || q->num_buffers > 0)
2186                 return -EBUSY;
2187
2188         /*
2189          * Start with count 1, driver can increase it in queue_setup()
2190          */
2191         count = 1;
2192
2193         dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2194                 (read) ? "read" : "write", count, q->fileio_read_once,
2195                 q->fileio_write_immediately);
2196
2197         fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2198         if (fileio == NULL)
2199                 return -ENOMEM;
2200
2201         fileio->read_once = q->fileio_read_once;
2202         fileio->write_immediately = q->fileio_write_immediately;
2203
2204         /*
2205          * Request buffers and use MMAP type to force driver
2206          * to allocate buffers by itself.
2207          */
2208         fileio->count = count;
2209         fileio->memory = VB2_MEMORY_MMAP;
2210         fileio->type = q->type;
2211         q->fileio = fileio;
2212         ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2213         if (ret)
2214                 goto err_kfree;
2215
2216         /*
2217          * Check if plane_count is correct
2218          * (multiplane buffers are not supported).
2219          */
2220         if (q->bufs[0]->num_planes != 1) {
2221                 ret = -EBUSY;
2222                 goto err_reqbufs;
2223         }
2224
2225         /*
2226          * Get kernel address of each buffer.
2227          */
2228         for (i = 0; i < q->num_buffers; i++) {
2229                 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2230                 if (fileio->bufs[i].vaddr == NULL) {
2231                         ret = -EINVAL;
2232                         goto err_reqbufs;
2233                 }
2234                 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2235         }
2236
2237         /*
2238          * Read mode requires pre queuing of all buffers.
2239          */
2240         if (read) {
2241                 /*
2242                  * Queue all buffers.
2243                  */
2244                 for (i = 0; i < q->num_buffers; i++) {
2245                         ret = vb2_core_qbuf(q, i, NULL);
2246                         if (ret)
2247                                 goto err_reqbufs;
2248                         fileio->bufs[i].queued = 1;
2249                 }
2250                 /*
2251                  * All buffers have been queued, so mark that by setting
2252                  * initial_index to q->num_buffers
2253                  */
2254                 fileio->initial_index = q->num_buffers;
2255                 fileio->cur_index = q->num_buffers;
2256         }
2257
2258         /*
2259          * Start streaming.
2260          */
2261         ret = vb2_core_streamon(q, q->type);
2262         if (ret)
2263                 goto err_reqbufs;
2264
2265         return ret;
2266
2267 err_reqbufs:
2268         fileio->count = 0;
2269         vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2270
2271 err_kfree:
2272         q->fileio = NULL;
2273         kfree(fileio);
2274         return ret;
2275 }
2276
2277 /*
2278  * __vb2_cleanup_fileio() - free resourced used by file io emulator
2279  * @q:          videobuf2 queue
2280  */
2281 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2282 {
2283         struct vb2_fileio_data *fileio = q->fileio;
2284
2285         if (fileio) {
2286                 vb2_core_streamoff(q, q->type);
2287                 q->fileio = NULL;
2288                 fileio->count = 0;
2289                 vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2290                 kfree(fileio);
2291                 dprintk(3, "file io emulator closed\n");
2292         }
2293         return 0;
2294 }
2295
2296 /*
2297  * __vb2_perform_fileio() - perform a single file io (read or write) operation
2298  * @q:          videobuf2 queue
2299  * @data:       pointed to target userspace buffer
2300  * @count:      number of bytes to read or write
2301  * @ppos:       file handle position tracking pointer
2302  * @nonblock:   mode selector (1 means blocking calls, 0 means nonblocking)
2303  * @read:       access mode selector (1 means read, 0 means write)
2304  */
2305 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2306                 loff_t *ppos, int nonblock, int read)
2307 {
2308         struct vb2_fileio_data *fileio;
2309         struct vb2_fileio_buf *buf;
2310         bool is_multiplanar = q->is_multiplanar;
2311         /*
2312          * When using write() to write data to an output video node the vb2 core
2313          * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2314          * else is able to provide this information with the write() operation.
2315          */
2316         bool copy_timestamp = !read && q->copy_timestamp;
2317         unsigned index;
2318         int ret;
2319
2320         dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2321                 read ? "read" : "write", (long)*ppos, count,
2322                 nonblock ? "non" : "");
2323
2324         if (!data)
2325                 return -EINVAL;
2326
2327         /*
2328          * Initialize emulator on first call.
2329          */
2330         if (!vb2_fileio_is_active(q)) {
2331                 ret = __vb2_init_fileio(q, read);
2332                 dprintk(3, "vb2_init_fileio result: %d\n", ret);
2333                 if (ret)
2334                         return ret;
2335         }
2336         fileio = q->fileio;
2337
2338         /*
2339          * Check if we need to dequeue the buffer.
2340          */
2341         index = fileio->cur_index;
2342         if (index >= q->num_buffers) {
2343                 struct vb2_buffer *b;
2344
2345                 /*
2346                  * Call vb2_dqbuf to get buffer back.
2347                  */
2348                 ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2349                 dprintk(5, "vb2_dqbuf result: %d\n", ret);
2350                 if (ret)
2351                         return ret;
2352                 fileio->dq_count += 1;
2353
2354                 fileio->cur_index = index;
2355                 buf = &fileio->bufs[index];
2356                 b = q->bufs[index];
2357
2358                 /*
2359                  * Get number of bytes filled by the driver
2360                  */
2361                 buf->pos = 0;
2362                 buf->queued = 0;
2363                 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2364                                  : vb2_plane_size(q->bufs[index], 0);
2365                 /* Compensate for data_offset on read in the multiplanar case. */
2366                 if (is_multiplanar && read &&
2367                                 b->planes[0].data_offset < buf->size) {
2368                         buf->pos = b->planes[0].data_offset;
2369                         buf->size -= buf->pos;
2370                 }
2371         } else {
2372                 buf = &fileio->bufs[index];
2373         }
2374
2375         /*
2376          * Limit count on last few bytes of the buffer.
2377          */
2378         if (buf->pos + count > buf->size) {
2379                 count = buf->size - buf->pos;
2380                 dprintk(5, "reducing read count: %zd\n", count);
2381         }
2382
2383         /*
2384          * Transfer data to userspace.
2385          */
2386         dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
2387                 count, index, buf->pos);
2388         if (read)
2389                 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2390         else
2391                 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2392         if (ret) {
2393                 dprintk(3, "error copying data\n");
2394                 return -EFAULT;
2395         }
2396
2397         /*
2398          * Update counters.
2399          */
2400         buf->pos += count;
2401         *ppos += count;
2402
2403         /*
2404          * Queue next buffer if required.
2405          */
2406         if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2407                 struct vb2_buffer *b = q->bufs[index];
2408
2409                 /*
2410                  * Check if this is the last buffer to read.
2411                  */
2412                 if (read && fileio->read_once && fileio->dq_count == 1) {
2413                         dprintk(3, "read limit reached\n");
2414                         return __vb2_cleanup_fileio(q);
2415                 }
2416
2417                 /*
2418                  * Call vb2_qbuf and give buffer to the driver.
2419                  */
2420                 b->planes[0].bytesused = buf->pos;
2421
2422                 if (copy_timestamp)
2423                         b->timestamp = ktime_get_ns();
2424                 ret = vb2_core_qbuf(q, index, NULL);
2425                 dprintk(5, "vb2_dbuf result: %d\n", ret);
2426                 if (ret)
2427                         return ret;
2428
2429                 /*
2430                  * Buffer has been queued, update the status
2431                  */
2432                 buf->pos = 0;
2433                 buf->queued = 1;
2434                 buf->size = vb2_plane_size(q->bufs[index], 0);
2435                 fileio->q_count += 1;
2436                 /*
2437                  * If we are queuing up buffers for the first time, then
2438                  * increase initial_index by one.
2439                  */
2440                 if (fileio->initial_index < q->num_buffers)
2441                         fileio->initial_index++;
2442                 /*
2443                  * The next buffer to use is either a buffer that's going to be
2444                  * queued for the first time (initial_index < q->num_buffers)
2445                  * or it is equal to q->num_buffers, meaning that the next
2446                  * time we need to dequeue a buffer since we've now queued up
2447                  * all the 'first time' buffers.
2448                  */
2449                 fileio->cur_index = fileio->initial_index;
2450         }
2451
2452         /*
2453          * Return proper number of bytes processed.
2454          */
2455         if (ret == 0)
2456                 ret = count;
2457         return ret;
2458 }
2459
2460 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2461                 loff_t *ppos, int nonblocking)
2462 {
2463         return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2464 }
2465 EXPORT_SYMBOL_GPL(vb2_read);
2466
2467 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2468                 loff_t *ppos, int nonblocking)
2469 {
2470         return __vb2_perform_fileio(q, (char __user *) data, count,
2471                                                         ppos, nonblocking, 0);
2472 }
2473 EXPORT_SYMBOL_GPL(vb2_write);
2474
2475 struct vb2_threadio_data {
2476         struct task_struct *thread;
2477         vb2_thread_fnc fnc;
2478         void *priv;
2479         bool stop;
2480 };
2481
2482 static int vb2_thread(void *data)
2483 {
2484         struct vb2_queue *q = data;
2485         struct vb2_threadio_data *threadio = q->threadio;
2486         bool copy_timestamp = false;
2487         unsigned prequeue = 0;
2488         unsigned index = 0;
2489         int ret = 0;
2490
2491         if (q->is_output) {
2492                 prequeue = q->num_buffers;
2493                 copy_timestamp = q->copy_timestamp;
2494         }
2495
2496         set_freezable();
2497
2498         for (;;) {
2499                 struct vb2_buffer *vb;
2500
2501                 /*
2502                  * Call vb2_dqbuf to get buffer back.
2503                  */
2504                 if (prequeue) {
2505                         vb = q->bufs[index++];
2506                         prequeue--;
2507                 } else {
2508                         call_void_qop(q, wait_finish, q);
2509                         if (!threadio->stop)
2510                                 ret = vb2_core_dqbuf(q, &index, NULL, 0);
2511                         call_void_qop(q, wait_prepare, q);
2512                         dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
2513                         if (!ret)
2514                                 vb = q->bufs[index];
2515                 }
2516                 if (ret || threadio->stop)
2517                         break;
2518                 try_to_freeze();
2519
2520                 if (vb->state != VB2_BUF_STATE_ERROR)
2521                         if (threadio->fnc(vb, threadio->priv))
2522                                 break;
2523                 call_void_qop(q, wait_finish, q);
2524                 if (copy_timestamp)
2525                         vb->timestamp = ktime_get_ns();;
2526                 if (!threadio->stop)
2527                         ret = vb2_core_qbuf(q, vb->index, NULL);
2528                 call_void_qop(q, wait_prepare, q);
2529                 if (ret || threadio->stop)
2530                         break;
2531         }
2532
2533         /* Hmm, linux becomes *very* unhappy without this ... */
2534         while (!kthread_should_stop()) {
2535                 set_current_state(TASK_INTERRUPTIBLE);
2536                 schedule();
2537         }
2538         return 0;
2539 }
2540
2541 /*
2542  * This function should not be used for anything else but the videobuf2-dvb
2543  * support. If you think you have another good use-case for this, then please
2544  * contact the linux-media mailinglist first.
2545  */
2546 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
2547                      const char *thread_name)
2548 {
2549         struct vb2_threadio_data *threadio;
2550         int ret = 0;
2551
2552         if (q->threadio)
2553                 return -EBUSY;
2554         if (vb2_is_busy(q))
2555                 return -EBUSY;
2556         if (WARN_ON(q->fileio))
2557                 return -EBUSY;
2558
2559         threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
2560         if (threadio == NULL)
2561                 return -ENOMEM;
2562         threadio->fnc = fnc;
2563         threadio->priv = priv;
2564
2565         ret = __vb2_init_fileio(q, !q->is_output);
2566         dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
2567         if (ret)
2568                 goto nomem;
2569         q->threadio = threadio;
2570         threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
2571         if (IS_ERR(threadio->thread)) {
2572                 ret = PTR_ERR(threadio->thread);
2573                 threadio->thread = NULL;
2574                 goto nothread;
2575         }
2576         return 0;
2577
2578 nothread:
2579         __vb2_cleanup_fileio(q);
2580 nomem:
2581         kfree(threadio);
2582         return ret;
2583 }
2584 EXPORT_SYMBOL_GPL(vb2_thread_start);
2585
2586 int vb2_thread_stop(struct vb2_queue *q)
2587 {
2588         struct vb2_threadio_data *threadio = q->threadio;
2589         int err;
2590
2591         if (threadio == NULL)
2592                 return 0;
2593         threadio->stop = true;
2594         /* Wake up all pending sleeps in the thread */
2595         vb2_queue_error(q);
2596         err = kthread_stop(threadio->thread);
2597         __vb2_cleanup_fileio(q);
2598         threadio->thread = NULL;
2599         kfree(threadio);
2600         q->threadio = NULL;
2601         return err;
2602 }
2603 EXPORT_SYMBOL_GPL(vb2_thread_stop);
2604
2605 MODULE_DESCRIPTION("Media buffer core framework");
2606 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2607 MODULE_LICENSE("GPL");