drivers/media/v4l2-core/v4l2-mem2mem.c

   1 /*
   2  * Memory-to-memory device framework for Video for Linux 2 and videobuf.
   3  *
   4  * Helper functions for devices that use videobuf buffers for both their
   5  * source and destination.
   6  *
   7  * Copyright (c) 2009-2010 Samsung Electronics Co., Ltd.
   8  * Pawel Osciak, <[email protected]>
   9  * Marek Szyprowski, <[email protected]>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by the
  13  * Free Software Foundation; either version 2 of the License, or (at your
  14  * option) any later version.
  15  */
  16 #include <linux/module.h>
  17 #include <linux/sched.h>
  18 #include <linux/slab.h>
  19
  20 #include <media/videobuf2-v4l2.h>
  21 #include <media/v4l2-mem2mem.h>
  22 #include <media/v4l2-dev.h>
  23 #include <media/v4l2-fh.h>
  24 #include <media/v4l2-event.h>
  25
  26 MODULE_DESCRIPTION("Mem to mem device framework for videobuf");
  27 MODULE_AUTHOR("Pawel Osciak, <[email protected]>");
  28 MODULE_LICENSE("GPL");
  29
  30 static bool debug;
  31 module_param(debug, bool, 0644);
  32
  33 #define dprintk(fmt, arg...)                                            \
  34         do {                                                            \
  35                 if (debug)                                              \
  36                         printk(KERN_DEBUG "%s: " fmt, __func__, ## arg);\
  37         } while (0)
  38
  39
  40 /* Instance is already queued on the job_queue */
  41 #define TRANS_QUEUED            (1 << 0)
  42 /* Instance is currently running in hardware */
  43 #define TRANS_RUNNING           (1 << 1)
  44 /* Instance is currently aborting */
  45 #define TRANS_ABORT             (1 << 2)
  46
  47
  48 /* Offset base for buffers on the destination queue - used to distinguish
  49  * between source and destination buffers when mmapping - they receive the same
  50  * offsets but for different queues */
  51 #define DST_QUEUE_OFF_BASE      (1 << 30)
  52
  53
  54 /**
  55  * struct v4l2_m2m_dev - per-device context
  56  * @curr_ctx:           currently running instance
  57  * @job_queue:          instances queued to run
  58  * @job_spinlock:       protects job_queue
  59  * @m2m_ops:            driver callbacks
  60  */
  61 struct v4l2_m2m_dev {
  62         struct v4l2_m2m_ctx     *curr_ctx;
  63
  64         struct list_head        job_queue;
  65         spinlock_t              job_spinlock;
  66
  67         const struct v4l2_m2m_ops *m2m_ops;
  68 };
  69
  70 static struct v4l2_m2m_queue_ctx *get_queue_ctx(struct v4l2_m2m_ctx *m2m_ctx,
  71                                                 enum v4l2_buf_type type)
  72 {
  73         if (V4L2_TYPE_IS_OUTPUT(type))
  74                 return &m2m_ctx->out_q_ctx;
  75         else
  76                 return &m2m_ctx->cap_q_ctx;
  77 }
  78
  79 struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
  80                                        enum v4l2_buf_type type)
  81 {
  82         struct v4l2_m2m_queue_ctx *q_ctx;
  83
  84         q_ctx = get_queue_ctx(m2m_ctx, type);
  85         if (!q_ctx)
  86                 return NULL;
  87
  88         return &q_ctx->q;
  89 }
  90 EXPORT_SYMBOL(v4l2_m2m_get_vq);
  91
  92 void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx)
  93 {
  94         struct v4l2_m2m_buffer *b;
  95         unsigned long flags;
  96
  97         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
  98
  99         if (list_empty(&q_ctx->rdy_queue)) {
 100                 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 101                 return NULL;
 102         }
 103
 104         b = list_first_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list);
 105         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 106         return &b->vb;
 107 }
 108 EXPORT_SYMBOL_GPL(v4l2_m2m_next_buf);
 109
 110 void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx)
 111 {
 112         struct v4l2_m2m_buffer *b;
 113         unsigned long flags;
 114
 115         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 116         if (list_empty(&q_ctx->rdy_queue)) {
 117                 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 118                 return NULL;
 119         }
 120         b = list_first_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list);
 121         list_del(&b->list);
 122         q_ctx->num_rdy--;
 123         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 124
 125         return &b->vb;
 126 }
 127 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove);
 128
 129 void v4l2_m2m_buf_remove_by_buf(struct v4l2_m2m_queue_ctx *q_ctx,
 130                                 struct vb2_v4l2_buffer *vbuf)
 131 {
 132         struct v4l2_m2m_buffer *b;
 133         unsigned long flags;
 134
 135         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 136         b = container_of(vbuf, struct v4l2_m2m_buffer, vb);
 137         list_del(&b->list);
 138         q_ctx->num_rdy--;
 139         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 140 }
 141 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove_by_buf);
 142
 143 struct vb2_v4l2_buffer *
 144 v4l2_m2m_buf_remove_by_idx(struct v4l2_m2m_queue_ctx *q_ctx, unsigned int idx)
 145
 146 {
 147         struct v4l2_m2m_buffer *b, *tmp;
 148         struct vb2_v4l2_buffer *ret = NULL;
 149         unsigned long flags;
 150
 151         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 152         list_for_each_entry_safe(b, tmp, &q_ctx->rdy_queue, list) {
 153                 if (b->vb.vb2_buf.index == idx) {
 154                         list_del(&b->list);
 155                         q_ctx->num_rdy--;
 156                         ret = &b->vb;
 157                         break;
 158                 }
 159         }
 160         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 161
 162         return ret;
 163 }
 164 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove_by_idx);
 165
 166 /*
 167  * Scheduling handlers
 168  */
 169
 170 void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev)
 171 {
 172         unsigned long flags;
 173         void *ret = NULL;
 174
 175         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 176         if (m2m_dev->curr_ctx)
 177                 ret = m2m_dev->curr_ctx->priv;
 178         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 179
 180         return ret;
 181 }
 182 EXPORT_SYMBOL(v4l2_m2m_get_curr_priv);
 183
 184 /**
 185  * v4l2_m2m_try_run() - select next job to perform and run it if possible
 186  *
 187  * Get next transaction (if present) from the waiting jobs list and run it.
 188  */
 189 static void v4l2_m2m_try_run(struct v4l2_m2m_dev *m2m_dev)
 190 {
 191         unsigned long flags;
 192
 193         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 194         if (NULL != m2m_dev->curr_ctx) {
 195                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 196                 dprintk("Another instance is running, won't run now\n");
 197                 return;
 198         }
 199
 200         if (list_empty(&m2m_dev->job_queue)) {
 201                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 202                 dprintk("No job pending\n");
 203                 return;
 204         }
 205
 206         m2m_dev->curr_ctx = list_first_entry(&m2m_dev->job_queue,
 207                                    struct v4l2_m2m_ctx, queue);
 208         m2m_dev->curr_ctx->job_flags |= TRANS_RUNNING;
 209         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 210
 211         m2m_dev->m2m_ops->device_run(m2m_dev->curr_ctx->priv);
 212 }
 213
 214 void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx)
 215 {
 216         struct v4l2_m2m_dev *m2m_dev;
 217         unsigned long flags_job, flags_out, flags_cap;
 218
 219         m2m_dev = m2m_ctx->m2m_dev;
 220         dprintk("Trying to schedule a job for m2m_ctx: %p\n", m2m_ctx);
 221
 222         if (!m2m_ctx->out_q_ctx.q.streaming
 223             || !m2m_ctx->cap_q_ctx.q.streaming) {
 224                 dprintk("Streaming needs to be on for both queues\n");
 225                 return;
 226         }
 227
 228         spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
 229
 230         /* If the context is aborted then don't schedule it */
 231         if (m2m_ctx->job_flags & TRANS_ABORT) {
 232                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 233                 dprintk("Aborted context\n");
 234                 return;
 235         }
 236
 237         if (m2m_ctx->job_flags & TRANS_QUEUED) {
 238                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 239                 dprintk("On job queue already\n");
 240                 return;
 241         }
 242
 243         spin_lock_irqsave(&m2m_ctx->out_q_ctx.rdy_spinlock, flags_out);
 244         if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue)
 245             && !m2m_ctx->out_q_ctx.buffered) {
 246                 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock,
 247                                         flags_out);
 248                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 249                 dprintk("No input buffers available\n");
 250                 return;
 251         }
 252         spin_lock_irqsave(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap);
 253         if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)
 254             && !m2m_ctx->cap_q_ctx.buffered) {
 255                 spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock,
 256                                         flags_cap);
 257                 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock,
 258                                         flags_out);
 259                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 260                 dprintk("No output buffers available\n");
 261                 return;
 262         }
 263         spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap);
 264         spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags_out);
 265
 266         if (m2m_dev->m2m_ops->job_ready
 267                 && (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) {
 268                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 269                 dprintk("Driver not ready\n");
 270                 return;
 271         }
 272
 273         list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue);
 274         m2m_ctx->job_flags |= TRANS_QUEUED;
 275
 276         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 277
 278         v4l2_m2m_try_run(m2m_dev);
 279 }
 280 EXPORT_SYMBOL_GPL(v4l2_m2m_try_schedule);
 281
 282 /**
 283  * v4l2_m2m_cancel_job() - cancel pending jobs for the context
 284  *
 285  * In case of streamoff or release called on any context,
 286  * 1] If the context is currently running, then abort job will be called
 287  * 2] If the context is queued, then the context will be removed from
 288  *    the job_queue
 289  */
 290 static void v4l2_m2m_cancel_job(struct v4l2_m2m_ctx *m2m_ctx)
 291 {
 292         struct v4l2_m2m_dev *m2m_dev;
 293         unsigned long flags;
 294
 295         m2m_dev = m2m_ctx->m2m_dev;
 296         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 297
 298         m2m_ctx->job_flags |= TRANS_ABORT;
 299         if (m2m_ctx->job_flags & TRANS_RUNNING) {
 300                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 301                 m2m_dev->m2m_ops->job_abort(m2m_ctx->priv);
 302                 dprintk("m2m_ctx %p running, will wait to complete", m2m_ctx);
 303                 wait_event(m2m_ctx->finished,
 304                                 !(m2m_ctx->job_flags & TRANS_RUNNING));
 305         } else if (m2m_ctx->job_flags & TRANS_QUEUED) {
 306                 list_del(&m2m_ctx->queue);
 307                 m2m_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
 308                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 309                 dprintk("m2m_ctx: %p had been on queue and was removed\n",
 310                         m2m_ctx);
 311         } else {
 312                 /* Do nothing, was not on queue/running */
 313                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 314         }
 315 }
 316
 317 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
 318                          struct v4l2_m2m_ctx *m2m_ctx)
 319 {
 320         unsigned long flags;
 321
 322         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 323         if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) {
 324                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 325                 dprintk("Called by an instance not currently running\n");
 326                 return;
 327         }
 328
 329         list_del(&m2m_dev->curr_ctx->queue);
 330         m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
 331         wake_up(&m2m_dev->curr_ctx->finished);
 332         m2m_dev->curr_ctx = NULL;
 333
 334         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 335
 336         /* This instance might have more buffers ready, but since we do not
 337          * allow more than one job on the job_queue per instance, each has
 338          * to be scheduled separately after the previous one finishes. */
 339         v4l2_m2m_try_schedule(m2m_ctx);
 340         v4l2_m2m_try_run(m2m_dev);
 341 }
 342 EXPORT_SYMBOL(v4l2_m2m_job_finish);
 343
 344 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 345                      struct v4l2_requestbuffers *reqbufs)
 346 {
 347         struct vb2_queue *vq;
 348         int ret;
 349
 350         vq = v4l2_m2m_get_vq(m2m_ctx, reqbufs->type);
 351         ret = vb2_reqbufs(vq, reqbufs);
 352         /* If count == 0, then the owner has released all buffers and he
 353            is no longer owner of the queue. Otherwise we have an owner. */
 354         if (ret == 0)
 355                 vq->owner = reqbufs->count ? file->private_data : NULL;
 356
 357         return ret;
 358 }
 359 EXPORT_SYMBOL_GPL(v4l2_m2m_reqbufs);
 360
 361 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 362                       struct v4l2_buffer *buf)
 363 {
 364         struct vb2_queue *vq;
 365         int ret = 0;
 366         unsigned int i;
 367
 368         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 369         ret = vb2_querybuf(vq, buf);
 370
 371         /* Adjust MMAP memory offsets for the CAPTURE queue */
 372         if (buf->memory == V4L2_MEMORY_MMAP && !V4L2_TYPE_IS_OUTPUT(vq->type)) {
 373                 if (V4L2_TYPE_IS_MULTIPLANAR(vq->type)) {
 374                         for (i = 0; i < buf->length; ++i)
 375                                 buf->m.planes[i].m.mem_offset
 376                                         += DST_QUEUE_OFF_BASE;
 377                 } else {
 378                         buf->m.offset += DST_QUEUE_OFF_BASE;
 379                 }
 380         }
 381
 382         return ret;
 383 }
 384 EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf);
 385
 386 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 387                   struct v4l2_buffer *buf)
 388 {
 389         struct vb2_queue *vq;
 390         int ret;
 391
 392         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 393         ret = vb2_qbuf(vq, buf);
 394         if (!ret)
 395                 v4l2_m2m_try_schedule(m2m_ctx);
 396
 397         return ret;
 398 }
 399 EXPORT_SYMBOL_GPL(v4l2_m2m_qbuf);
 400
 401 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 402                    struct v4l2_buffer *buf)
 403 {
 404         struct vb2_queue *vq;
 405
 406         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 407         return vb2_dqbuf(vq, buf, file->f_flags & O_NONBLOCK);
 408 }
 409 EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
 410
 411 int v4l2_m2m_prepare_buf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 412                          struct v4l2_buffer *buf)
 413 {
 414         struct vb2_queue *vq;
 415         int ret;
 416
 417         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 418         ret = vb2_prepare_buf(vq, buf);
 419         if (!ret)
 420                 v4l2_m2m_try_schedule(m2m_ctx);
 421
 422         return ret;
 423 }
 424 EXPORT_SYMBOL_GPL(v4l2_m2m_prepare_buf);
 425
 426 int v4l2_m2m_create_bufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 427                          struct v4l2_create_buffers *create)
 428 {
 429         struct vb2_queue *vq;
 430
 431         vq = v4l2_m2m_get_vq(m2m_ctx, create->format.type);
 432         return vb2_create_bufs(vq, create);
 433 }
 434 EXPORT_SYMBOL_GPL(v4l2_m2m_create_bufs);
 435
 436 int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 437                   struct v4l2_exportbuffer *eb)
 438 {
 439         struct vb2_queue *vq;
 440
 441         vq = v4l2_m2m_get_vq(m2m_ctx, eb->type);
 442         return vb2_expbuf(vq, eb);
 443 }
 444 EXPORT_SYMBOL_GPL(v4l2_m2m_expbuf);
 445
 446 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 447                       enum v4l2_buf_type type)
 448 {
 449         struct vb2_queue *vq;
 450         int ret;
 451
 452         vq = v4l2_m2m_get_vq(m2m_ctx, type);
 453         ret = vb2_streamon(vq, type);
 454         if (!ret)
 455                 v4l2_m2m_try_schedule(m2m_ctx);
 456
 457         return ret;
 458 }
 459 EXPORT_SYMBOL_GPL(v4l2_m2m_streamon);
 460
 461 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 462                        enum v4l2_buf_type type)
 463 {
 464         struct v4l2_m2m_dev *m2m_dev;
 465         struct v4l2_m2m_queue_ctx *q_ctx;
 466         unsigned long flags_job, flags;
 467         int ret;
 468
 469         /* wait until the current context is dequeued from job_queue */
 470         v4l2_m2m_cancel_job(m2m_ctx);
 471
 472         q_ctx = get_queue_ctx(m2m_ctx, type);
 473         ret = vb2_streamoff(&q_ctx->q, type);
 474         if (ret)
 475                 return ret;
 476
 477         m2m_dev = m2m_ctx->m2m_dev;
 478         spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
 479         /* We should not be scheduled anymore, since we're dropping a queue. */
 480         if (m2m_ctx->job_flags & TRANS_QUEUED)
 481                 list_del(&m2m_ctx->queue);
 482         m2m_ctx->job_flags = 0;
 483
 484         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 485         /* Drop queue, since streamoff returns device to the same state as after
 486          * calling reqbufs. */
 487         INIT_LIST_HEAD(&q_ctx->rdy_queue);
 488         q_ctx->num_rdy = 0;
 489         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 490
 491         if (m2m_dev->curr_ctx == m2m_ctx) {
 492                 m2m_dev->curr_ctx = NULL;
 493                 wake_up(&m2m_ctx->finished);
 494         }
 495         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 496
 497         return 0;
 498 }
 499 EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff);
 500
 501 unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 502                            struct poll_table_struct *wait)
 503 {
 504         struct video_device *vfd = video_devdata(file);
 505         unsigned long req_events = poll_requested_events(wait);
 506         struct vb2_queue *src_q, *dst_q;
 507         struct vb2_buffer *src_vb = NULL, *dst_vb = NULL;
 508         unsigned int rc = 0;
 509         unsigned long flags;
 510
 511         if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
 512                 struct v4l2_fh *fh = file->private_data;
 513
 514                 if (v4l2_event_pending(fh))
 515                         rc = POLLPRI;
 516                 else if (req_events & POLLPRI)
 517                         poll_wait(file, &fh->wait, wait);
 518                 if (!(req_events & (POLLOUT | POLLWRNORM | POLLIN | POLLRDNORM)))
 519                         return rc;
 520         }
 521
 522         src_q = v4l2_m2m_get_src_vq(m2m_ctx);
 523         dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
 524
 525         /*
 526          * There has to be at least one buffer queued on each queued_list, which
 527          * means either in driver already or waiting for driver to claim it
 528          * and start processing.
 529          */
 530         if ((!src_q->streaming || list_empty(&src_q->queued_list))
 531                 && (!dst_q->streaming || list_empty(&dst_q->queued_list))) {
 532                 rc |= POLLERR;
 533                 goto end;
 534         }
 535
 536         spin_lock_irqsave(&src_q->done_lock, flags);
 537         if (list_empty(&src_q->done_list))
 538                 poll_wait(file, &src_q->done_wq, wait);
 539         spin_unlock_irqrestore(&src_q->done_lock, flags);
 540
 541         spin_lock_irqsave(&dst_q->done_lock, flags);
 542         if (list_empty(&dst_q->done_list)) {
 543                 /*
 544                  * If the last buffer was dequeued from the capture queue,
 545                  * return immediately. DQBUF will return -EPIPE.
 546                  */
 547                 if (dst_q->last_buffer_dequeued) {
 548                         spin_unlock_irqrestore(&dst_q->done_lock, flags);
 549                         return rc | POLLIN | POLLRDNORM;
 550                 }
 551
 552                 poll_wait(file, &dst_q->done_wq, wait);
 553         }
 554         spin_unlock_irqrestore(&dst_q->done_lock, flags);
 555
 556         spin_lock_irqsave(&src_q->done_lock, flags);
 557         if (!list_empty(&src_q->done_list))
 558                 src_vb = list_first_entry(&src_q->done_list, struct vb2_buffer,
 559                                                 done_entry);
 560         if (src_vb && (src_vb->state == VB2_BUF_STATE_DONE
 561                         || src_vb->state == VB2_BUF_STATE_ERROR))
 562                 rc |= POLLOUT | POLLWRNORM;
 563         spin_unlock_irqrestore(&src_q->done_lock, flags);
 564
 565         spin_lock_irqsave(&dst_q->done_lock, flags);
 566         if (!list_empty(&dst_q->done_list))
 567                 dst_vb = list_first_entry(&dst_q->done_list, struct vb2_buffer,
 568                                                 done_entry);
 569         if (dst_vb && (dst_vb->state == VB2_BUF_STATE_DONE
 570                         || dst_vb->state == VB2_BUF_STATE_ERROR))
 571                 rc |= POLLIN | POLLRDNORM;
 572         spin_unlock_irqrestore(&dst_q->done_lock, flags);
 573
 574 end:
 575         return rc;
 576 }
 577 EXPORT_SYMBOL_GPL(v4l2_m2m_poll);
 578
 579 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 580                          struct vm_area_struct *vma)
 581 {
 582         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 583         struct vb2_queue *vq;
 584
 585         if (offset < DST_QUEUE_OFF_BASE) {
 586                 vq = v4l2_m2m_get_src_vq(m2m_ctx);
 587         } else {
 588                 vq = v4l2_m2m_get_dst_vq(m2m_ctx);
 589                 vma->vm_pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT);
 590         }
 591
 592         return vb2_mmap(vq, vma);
 593 }
 594 EXPORT_SYMBOL(v4l2_m2m_mmap);
 595
 596 struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops)
 597 {
 598         struct v4l2_m2m_dev *m2m_dev;
 599
 600         if (!m2m_ops || WARN_ON(!m2m_ops->device_run) ||
 601                         WARN_ON(!m2m_ops->job_abort))
 602                 return ERR_PTR(-EINVAL);
 603
 604         m2m_dev = kzalloc(sizeof *m2m_dev, GFP_KERNEL);
 605         if (!m2m_dev)
 606                 return ERR_PTR(-ENOMEM);
 607
 608         m2m_dev->curr_ctx = NULL;
 609         m2m_dev->m2m_ops = m2m_ops;
 610         INIT_LIST_HEAD(&m2m_dev->job_queue);
 611         spin_lock_init(&m2m_dev->job_spinlock);
 612
 613         return m2m_dev;
 614 }
 615 EXPORT_SYMBOL_GPL(v4l2_m2m_init);
 616
 617 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev)
 618 {
 619         kfree(m2m_dev);
 620 }
 621 EXPORT_SYMBOL_GPL(v4l2_m2m_release);
 622
 623 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
 624                 void *drv_priv,
 625                 int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq))
 626 {
 627         struct v4l2_m2m_ctx *m2m_ctx;
 628         struct v4l2_m2m_queue_ctx *out_q_ctx, *cap_q_ctx;
 629         int ret;
 630
 631         m2m_ctx = kzalloc(sizeof *m2m_ctx, GFP_KERNEL);
 632         if (!m2m_ctx)
 633                 return ERR_PTR(-ENOMEM);
 634
 635         m2m_ctx->priv = drv_priv;
 636         m2m_ctx->m2m_dev = m2m_dev;
 637         init_waitqueue_head(&m2m_ctx->finished);
 638
 639         out_q_ctx = &m2m_ctx->out_q_ctx;
 640         cap_q_ctx = &m2m_ctx->cap_q_ctx;
 641
 642         INIT_LIST_HEAD(&out_q_ctx->rdy_queue);
 643         INIT_LIST_HEAD(&cap_q_ctx->rdy_queue);
 644         spin_lock_init(&out_q_ctx->rdy_spinlock);
 645         spin_lock_init(&cap_q_ctx->rdy_spinlock);
 646
 647         INIT_LIST_HEAD(&m2m_ctx->queue);
 648
 649         ret = queue_init(drv_priv, &out_q_ctx->q, &cap_q_ctx->q);
 650
 651         if (ret)
 652                 goto err;
 653         /*
 654          * If both queues use same mutex assign it as the common buffer
 655          * queues lock to the m2m context. This lock is used in the
 656          * v4l2_m2m_ioctl_* helpers.
 657          */
 658         if (out_q_ctx->q.lock == cap_q_ctx->q.lock)
 659                 m2m_ctx->q_lock = out_q_ctx->q.lock;
 660
 661         return m2m_ctx;
 662 err:
 663         kfree(m2m_ctx);
 664         return ERR_PTR(ret);
 665 }
 666 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_init);
 667
 668 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx)
 669 {
 670         /* wait until the current context is dequeued from job_queue */
 671         v4l2_m2m_cancel_job(m2m_ctx);
 672
 673         vb2_queue_release(&m2m_ctx->cap_q_ctx.q);
 674         vb2_queue_release(&m2m_ctx->out_q_ctx.q);
 675
 676         kfree(m2m_ctx);
 677 }
 678 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_release);
 679
 680 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx,
 681                 struct vb2_v4l2_buffer *vbuf)
 682 {
 683         struct v4l2_m2m_buffer *b = container_of(vbuf,
 684                                 struct v4l2_m2m_buffer, vb);
 685         struct v4l2_m2m_queue_ctx *q_ctx;
 686         unsigned long flags;
 687
 688         q_ctx = get_queue_ctx(m2m_ctx, vbuf->vb2_buf.vb2_queue->type);
 689         if (!q_ctx)
 690                 return;
 691
 692         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 693         list_add_tail(&b->list, &q_ctx->rdy_queue);
 694         q_ctx->num_rdy++;
 695         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 696 }
 697 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);
 698
 699 /* Videobuf2 ioctl helpers */
 700
 701 int v4l2_m2m_ioctl_reqbufs(struct file *file, void *priv,
 702                                 struct v4l2_requestbuffers *rb)
 703 {
 704         struct v4l2_fh *fh = file->private_data;
 705
 706         return v4l2_m2m_reqbufs(file, fh->m2m_ctx, rb);
 707 }
 708 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_reqbufs);
 709
 710 int v4l2_m2m_ioctl_create_bufs(struct file *file, void *priv,
 711                                 struct v4l2_create_buffers *create)
 712 {
 713         struct v4l2_fh *fh = file->private_data;
 714
 715         return v4l2_m2m_create_bufs(file, fh->m2m_ctx, create);
 716 }
 717 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_create_bufs);
 718
 719 int v4l2_m2m_ioctl_querybuf(struct file *file, void *priv,
 720                                 struct v4l2_buffer *buf)
 721 {
 722         struct v4l2_fh *fh = file->private_data;
 723
 724         return v4l2_m2m_querybuf(file, fh->m2m_ctx, buf);
 725 }
 726 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_querybuf);
 727
 728 int v4l2_m2m_ioctl_qbuf(struct file *file, void *priv,
 729                                 struct v4l2_buffer *buf)
 730 {
 731         struct v4l2_fh *fh = file->private_data;
 732
 733         return v4l2_m2m_qbuf(file, fh->m2m_ctx, buf);
 734 }
 735 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_qbuf);
 736
 737 int v4l2_m2m_ioctl_dqbuf(struct file *file, void *priv,
 738                                 struct v4l2_buffer *buf)
 739 {
 740         struct v4l2_fh *fh = file->private_data;
 741
 742         return v4l2_m2m_dqbuf(file, fh->m2m_ctx, buf);
 743 }
 744 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_dqbuf);
 745
 746 int v4l2_m2m_ioctl_prepare_buf(struct file *file, void *priv,
 747                                struct v4l2_buffer *buf)
 748 {
 749         struct v4l2_fh *fh = file->private_data;
 750
 751         return v4l2_m2m_prepare_buf(file, fh->m2m_ctx, buf);
 752 }
 753 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_prepare_buf);
 754
 755 int v4l2_m2m_ioctl_expbuf(struct file *file, void *priv,
 756                                 struct v4l2_exportbuffer *eb)
 757 {
 758         struct v4l2_fh *fh = file->private_data;
 759
 760         return v4l2_m2m_expbuf(file, fh->m2m_ctx, eb);
 761 }
 762 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_expbuf);
 763
 764 int v4l2_m2m_ioctl_streamon(struct file *file, void *priv,
 765                                 enum v4l2_buf_type type)
 766 {
 767         struct v4l2_fh *fh = file->private_data;
 768
 769         return v4l2_m2m_streamon(file, fh->m2m_ctx, type);
 770 }
 771 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_streamon);
 772
 773 int v4l2_m2m_ioctl_streamoff(struct file *file, void *priv,
 774                                 enum v4l2_buf_type type)
 775 {
 776         struct v4l2_fh *fh = file->private_data;
 777
 778         return v4l2_m2m_streamoff(file, fh->m2m_ctx, type);
 779 }
 780 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_streamoff);
 781
 782 /*
 783  * v4l2_file_operations helpers. It is assumed here same lock is used
 784  * for the output and the capture buffer queue.
 785  */
 786
 787 int v4l2_m2m_fop_mmap(struct file *file, struct vm_area_struct *vma)
 788 {
 789         struct v4l2_fh *fh = file->private_data;
 790
 791         return v4l2_m2m_mmap(file, fh->m2m_ctx, vma);
 792 }
 793 EXPORT_SYMBOL_GPL(v4l2_m2m_fop_mmap);
 794
 795 unsigned int v4l2_m2m_fop_poll(struct file *file, poll_table *wait)
 796 {
 797         struct v4l2_fh *fh = file->private_data;
 798         struct v4l2_m2m_ctx *m2m_ctx = fh->m2m_ctx;
 799         unsigned int ret;
 800
 801         if (m2m_ctx->q_lock)
 802                 mutex_lock(m2m_ctx->q_lock);
 803
 804         ret = v4l2_m2m_poll(file, m2m_ctx, wait);
 805
 806         if (m2m_ctx->q_lock)
 807                 mutex_unlock(m2m_ctx->q_lock);
 808
 809         return ret;
 810 }
 811 EXPORT_SYMBOL_GPL(v4l2_m2m_fop_poll);
 812