drivers/media/video/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, <pawel@osciak.com>
   9  * Marek Szyprowski, <m.szyprowski@samsung.com>
  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-core.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, <pawel@osciak.com>");
  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
  45
  46 /* Offset base for buffers on the destination queue - used to distinguish
  47  * between source and destination buffers when mmapping - they receive the same
  48  * offsets but for different queues */
  49 #define DST_QUEUE_OFF_BASE      (1 << 30)
  50
  51
  52 /**
  53  * struct v4l2_m2m_dev - per-device context
  54  * @curr_ctx:           currently running instance
  55  * @job_queue:          instances queued to run
  56  * @job_spinlock:       protects job_queue
  57  * @m2m_ops:            driver callbacks
  58  */
  59 struct v4l2_m2m_dev {
  60         struct v4l2_m2m_ctx     *curr_ctx;
  61
  62         struct list_head        job_queue;
  63         spinlock_t              job_spinlock;
  64
  65         struct v4l2_m2m_ops     *m2m_ops;
  66 };
  67
  68 static struct v4l2_m2m_queue_ctx *get_queue_ctx(struct v4l2_m2m_ctx *m2m_ctx,
  69                                                 enum v4l2_buf_type type)
  70 {
  71         if (V4L2_TYPE_IS_OUTPUT(type))
  72                 return &m2m_ctx->out_q_ctx;
  73         else
  74                 return &m2m_ctx->cap_q_ctx;
  75 }
  76
  77 /**
  78  * v4l2_m2m_get_vq() - return vb2_queue for the given type
  79  */
  80 struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
  81                                        enum v4l2_buf_type type)
  82 {
  83         struct v4l2_m2m_queue_ctx *q_ctx;
  84
  85         q_ctx = get_queue_ctx(m2m_ctx, type);
  86         if (!q_ctx)
  87                 return NULL;
  88
  89         return &q_ctx->q;
  90 }
  91 EXPORT_SYMBOL(v4l2_m2m_get_vq);
  92
  93 /**
  94  * v4l2_m2m_next_buf() - return next buffer from the list of ready buffers
  95  */
  96 void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx)
  97 {
  98         struct v4l2_m2m_buffer *b = NULL;
  99         unsigned long flags;
 100
 101         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 102
 103         if (list_empty(&q_ctx->rdy_queue)) {
 104                 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 105                 return NULL;
 106         }
 107
 108         b = list_entry(q_ctx->rdy_queue.next, struct v4l2_m2m_buffer, list);
 109         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 110         return &b->vb;
 111 }
 112 EXPORT_SYMBOL_GPL(v4l2_m2m_next_buf);
 113
 114 /**
 115  * v4l2_m2m_buf_remove() - take off a buffer from the list of ready buffers and
 116  * return it
 117  */
 118 void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx)
 119 {
 120         struct v4l2_m2m_buffer *b = NULL;
 121         unsigned long flags;
 122
 123         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 124         if (list_empty(&q_ctx->rdy_queue)) {
 125                 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 126                 return NULL;
 127         }
 128         b = list_entry(q_ctx->rdy_queue.next, struct v4l2_m2m_buffer, list);
 129         list_del(&b->list);
 130         q_ctx->num_rdy--;
 131         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 132
 133         return &b->vb;
 134 }
 135 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove);
 136
 137 /*
 138  * Scheduling handlers
 139  */
 140
 141 /**
 142  * v4l2_m2m_get_curr_priv() - return driver private data for the currently
 143  * running instance or NULL if no instance is running
 144  */
 145 void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev)
 146 {
 147         unsigned long flags;
 148         void *ret = NULL;
 149
 150         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 151         if (m2m_dev->curr_ctx)
 152                 ret = m2m_dev->curr_ctx->priv;
 153         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 154
 155         return ret;
 156 }
 157 EXPORT_SYMBOL(v4l2_m2m_get_curr_priv);
 158
 159 /**
 160  * v4l2_m2m_try_run() - select next job to perform and run it if possible
 161  *
 162  * Get next transaction (if present) from the waiting jobs list and run it.
 163  */
 164 static void v4l2_m2m_try_run(struct v4l2_m2m_dev *m2m_dev)
 165 {
 166         unsigned long flags;
 167
 168         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 169         if (NULL != m2m_dev->curr_ctx) {
 170                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 171                 dprintk("Another instance is running, won't run now\n");
 172                 return;
 173         }
 174
 175         if (list_empty(&m2m_dev->job_queue)) {
 176                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 177                 dprintk("No job pending\n");
 178                 return;
 179         }
 180
 181         m2m_dev->curr_ctx = list_entry(m2m_dev->job_queue.next,
 182                                    struct v4l2_m2m_ctx, queue);
 183         m2m_dev->curr_ctx->job_flags |= TRANS_RUNNING;
 184         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 185
 186         m2m_dev->m2m_ops->device_run(m2m_dev->curr_ctx->priv);
 187 }
 188
 189 /**
 190  * v4l2_m2m_try_schedule() - check whether an instance is ready to be added to
 191  * the pending job queue and add it if so.
 192  * @m2m_ctx:    m2m context assigned to the instance to be checked
 193  *
 194  * There are three basic requirements an instance has to meet to be able to run:
 195  * 1) at least one source buffer has to be queued,
 196  * 2) at least one destination buffer has to be queued,
 197  * 3) streaming has to be on.
 198  *
 199  * There may also be additional, custom requirements. In such case the driver
 200  * should supply a custom callback (job_ready in v4l2_m2m_ops) that should
 201  * return 1 if the instance is ready.
 202  * An example of the above could be an instance that requires more than one
 203  * src/dst buffer per transaction.
 204  */
 205 static void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx)
 206 {
 207         struct v4l2_m2m_dev *m2m_dev;
 208         unsigned long flags_job, flags;
 209
 210         m2m_dev = m2m_ctx->m2m_dev;
 211         dprintk("Trying to schedule a job for m2m_ctx: %p\n", m2m_ctx);
 212
 213         if (!m2m_ctx->out_q_ctx.q.streaming
 214             || !m2m_ctx->cap_q_ctx.q.streaming) {
 215                 dprintk("Streaming needs to be on for both queues\n");
 216                 return;
 217         }
 218
 219         spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
 220         if (m2m_ctx->job_flags & TRANS_QUEUED) {
 221                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 222                 dprintk("On job queue already\n");
 223                 return;
 224         }
 225
 226         spin_lock_irqsave(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
 227         if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue)) {
 228                 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
 229                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 230                 dprintk("No input buffers available\n");
 231                 return;
 232         }
 233         if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)) {
 234                 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
 235                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 236                 dprintk("No output buffers available\n");
 237                 return;
 238         }
 239         spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
 240
 241         if (m2m_dev->m2m_ops->job_ready
 242                 && (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) {
 243                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 244                 dprintk("Driver not ready\n");
 245                 return;
 246         }
 247
 248         list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue);
 249         m2m_ctx->job_flags |= TRANS_QUEUED;
 250
 251         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 252
 253         v4l2_m2m_try_run(m2m_dev);
 254 }
 255
 256 /**
 257  * v4l2_m2m_job_finish() - inform the framework that a job has been finished
 258  * and have it clean up
 259  *
 260  * Called by a driver to yield back the device after it has finished with it.
 261  * Should be called as soon as possible after reaching a state which allows
 262  * other instances to take control of the device.
 263  *
 264  * This function has to be called only after device_run() callback has been
 265  * called on the driver. To prevent recursion, it should not be called directly
 266  * from the device_run() callback though.
 267  */
 268 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
 269                          struct v4l2_m2m_ctx *m2m_ctx)
 270 {
 271         unsigned long flags;
 272
 273         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 274         if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) {
 275                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 276                 dprintk("Called by an instance not currently running\n");
 277                 return;
 278         }
 279
 280         list_del(&m2m_dev->curr_ctx->queue);
 281         m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
 282         wake_up(&m2m_dev->curr_ctx->finished);
 283         m2m_dev->curr_ctx = NULL;
 284
 285         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 286
 287         /* This instance might have more buffers ready, but since we do not
 288          * allow more than one job on the job_queue per instance, each has
 289          * to be scheduled separately after the previous one finishes. */
 290         v4l2_m2m_try_schedule(m2m_ctx);
 291         v4l2_m2m_try_run(m2m_dev);
 292 }
 293 EXPORT_SYMBOL(v4l2_m2m_job_finish);
 294
 295 /**
 296  * v4l2_m2m_reqbufs() - multi-queue-aware REQBUFS multiplexer
 297  */
 298 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 299                      struct v4l2_requestbuffers *reqbufs)
 300 {
 301         struct vb2_queue *vq;
 302
 303         vq = v4l2_m2m_get_vq(m2m_ctx, reqbufs->type);
 304         return vb2_reqbufs(vq, reqbufs);
 305 }
 306 EXPORT_SYMBOL_GPL(v4l2_m2m_reqbufs);
 307
 308 /**
 309  * v4l2_m2m_querybuf() - multi-queue-aware QUERYBUF multiplexer
 310  *
 311  * See v4l2_m2m_mmap() documentation for details.
 312  */
 313 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 314                       struct v4l2_buffer *buf)
 315 {
 316         struct vb2_queue *vq;
 317         int ret = 0;
 318         unsigned int i;
 319
 320         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 321         ret = vb2_querybuf(vq, buf);
 322
 323         /* Adjust MMAP memory offsets for the CAPTURE queue */
 324         if (buf->memory == V4L2_MEMORY_MMAP && !V4L2_TYPE_IS_OUTPUT(vq->type)) {
 325                 if (V4L2_TYPE_IS_MULTIPLANAR(vq->type)) {
 326                         for (i = 0; i < buf->length; ++i)
 327                                 buf->m.planes[i].m.mem_offset
 328                                         += DST_QUEUE_OFF_BASE;
 329                 } else {
 330                         buf->m.offset += DST_QUEUE_OFF_BASE;
 331                 }
 332         }
 333
 334         return ret;
 335 }
 336 EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf);
 337
 338 /**
 339  * v4l2_m2m_qbuf() - enqueue a source or destination buffer, depending on
 340  * the type
 341  */
 342 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 343                   struct v4l2_buffer *buf)
 344 {
 345         struct vb2_queue *vq;
 346         int ret;
 347
 348         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 349         ret = vb2_qbuf(vq, buf);
 350         if (!ret)
 351                 v4l2_m2m_try_schedule(m2m_ctx);
 352
 353         return ret;
 354 }
 355 EXPORT_SYMBOL_GPL(v4l2_m2m_qbuf);
 356
 357 /**
 358  * v4l2_m2m_dqbuf() - dequeue a source or destination buffer, depending on
 359  * the type
 360  */
 361 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 362                    struct v4l2_buffer *buf)
 363 {
 364         struct vb2_queue *vq;
 365
 366         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 367         return vb2_dqbuf(vq, buf, file->f_flags & O_NONBLOCK);
 368 }
 369 EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
 370
 371 /**
 372  * v4l2_m2m_streamon() - turn on streaming for a video queue
 373  */
 374 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 375                       enum v4l2_buf_type type)
 376 {
 377         struct vb2_queue *vq;
 378         int ret;
 379
 380         vq = v4l2_m2m_get_vq(m2m_ctx, type);
 381         ret = vb2_streamon(vq, type);
 382         if (!ret)
 383                 v4l2_m2m_try_schedule(m2m_ctx);
 384
 385         return ret;
 386 }
 387 EXPORT_SYMBOL_GPL(v4l2_m2m_streamon);
 388
 389 /**
 390  * v4l2_m2m_streamoff() - turn off streaming for a video queue
 391  */
 392 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 393                        enum v4l2_buf_type type)
 394 {
 395         struct vb2_queue *vq;
 396
 397         vq = v4l2_m2m_get_vq(m2m_ctx, type);
 398         return vb2_streamoff(vq, type);
 399 }
 400 EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff);
 401
 402 /**
 403  * v4l2_m2m_poll() - poll replacement, for destination buffers only
 404  *
 405  * Call from the driver's poll() function. Will poll both queues. If a buffer
 406  * is available to dequeue (with dqbuf) from the source queue, this will
 407  * indicate that a non-blocking write can be performed, while read will be
 408  * returned in case of the destination queue.
 409  */
 410 unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 411                            struct poll_table_struct *wait)
 412 {
 413         struct video_device *vfd = video_devdata(file);
 414         unsigned long req_events = poll_requested_events(wait);
 415         struct vb2_queue *src_q, *dst_q;
 416         struct vb2_buffer *src_vb = NULL, *dst_vb = NULL;
 417         unsigned int rc = 0;
 418         unsigned long flags;
 419
 420         if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
 421                 struct v4l2_fh *fh = file->private_data;
 422
 423                 if (v4l2_event_pending(fh))
 424                         rc = POLLPRI;
 425                 else if (req_events & POLLPRI)
 426                         poll_wait(file, &fh->wait, wait);
 427                 if (!(req_events & (POLLOUT | POLLWRNORM | POLLIN | POLLRDNORM)))
 428                         return rc;
 429         }
 430
 431         src_q = v4l2_m2m_get_src_vq(m2m_ctx);
 432         dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
 433
 434         /*
 435          * There has to be at least one buffer queued on each queued_list, which
 436          * means either in driver already or waiting for driver to claim it
 437          * and start processing.
 438          */
 439         if ((!src_q->streaming || list_empty(&src_q->queued_list))
 440                 && (!dst_q->streaming || list_empty(&dst_q->queued_list))) {
 441                 rc |= POLLERR;
 442                 goto end;
 443         }
 444
 445         if (m2m_ctx->m2m_dev->m2m_ops->unlock)
 446                 m2m_ctx->m2m_dev->m2m_ops->unlock(m2m_ctx->priv);
 447
 448         poll_wait(file, &src_q->done_wq, wait);
 449         poll_wait(file, &dst_q->done_wq, wait);
 450
 451         if (m2m_ctx->m2m_dev->m2m_ops->lock)
 452                 m2m_ctx->m2m_dev->m2m_ops->lock(m2m_ctx->priv);
 453
 454         spin_lock_irqsave(&src_q->done_lock, flags);
 455         if (!list_empty(&src_q->done_list))
 456                 src_vb = list_first_entry(&src_q->done_list, struct vb2_buffer,
 457                                                 done_entry);
 458         if (src_vb && (src_vb->state == VB2_BUF_STATE_DONE
 459                         || src_vb->state == VB2_BUF_STATE_ERROR))
 460                 rc |= POLLOUT | POLLWRNORM;
 461         spin_unlock_irqrestore(&src_q->done_lock, flags);
 462
 463         spin_lock_irqsave(&dst_q->done_lock, flags);
 464         if (!list_empty(&dst_q->done_list))
 465                 dst_vb = list_first_entry(&dst_q->done_list, struct vb2_buffer,
 466                                                 done_entry);
 467         if (dst_vb && (dst_vb->state == VB2_BUF_STATE_DONE
 468                         || dst_vb->state == VB2_BUF_STATE_ERROR))
 469                 rc |= POLLIN | POLLRDNORM;
 470         spin_unlock_irqrestore(&dst_q->done_lock, flags);
 471
 472 end:
 473         return rc;
 474 }
 475 EXPORT_SYMBOL_GPL(v4l2_m2m_poll);
 476
 477 /**
 478  * v4l2_m2m_mmap() - source and destination queues-aware mmap multiplexer
 479  *
 480  * Call from driver's mmap() function. Will handle mmap() for both queues
 481  * seamlessly for videobuffer, which will receive normal per-queue offsets and
 482  * proper videobuf queue pointers. The differentiation is made outside videobuf
 483  * by adding a predefined offset to buffers from one of the queues and
 484  * subtracting it before passing it back to videobuf. Only drivers (and
 485  * thus applications) receive modified offsets.
 486  */
 487 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 488                          struct vm_area_struct *vma)
 489 {
 490         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 491         struct vb2_queue *vq;
 492
 493         if (offset < DST_QUEUE_OFF_BASE) {
 494                 vq = v4l2_m2m_get_src_vq(m2m_ctx);
 495         } else {
 496                 vq = v4l2_m2m_get_dst_vq(m2m_ctx);
 497                 vma->vm_pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT);
 498         }
 499
 500         return vb2_mmap(vq, vma);
 501 }
 502 EXPORT_SYMBOL(v4l2_m2m_mmap);
 503
 504 /**
 505  * v4l2_m2m_init() - initialize per-driver m2m data
 506  *
 507  * Usually called from driver's probe() function.
 508  */
 509 struct v4l2_m2m_dev *v4l2_m2m_init(struct v4l2_m2m_ops *m2m_ops)
 510 {
 511         struct v4l2_m2m_dev *m2m_dev;
 512
 513         if (!m2m_ops)
 514                 return ERR_PTR(-EINVAL);
 515
 516         BUG_ON(!m2m_ops->device_run);
 517         BUG_ON(!m2m_ops->job_abort);
 518
 519         m2m_dev = kzalloc(sizeof *m2m_dev, GFP_KERNEL);
 520         if (!m2m_dev)
 521                 return ERR_PTR(-ENOMEM);
 522
 523         m2m_dev->curr_ctx = NULL;
 524         m2m_dev->m2m_ops = m2m_ops;
 525         INIT_LIST_HEAD(&m2m_dev->job_queue);
 526         spin_lock_init(&m2m_dev->job_spinlock);
 527
 528         return m2m_dev;
 529 }
 530 EXPORT_SYMBOL_GPL(v4l2_m2m_init);
 531
 532 /**
 533  * v4l2_m2m_release() - cleans up and frees a m2m_dev structure
 534  *
 535  * Usually called from driver's remove() function.
 536  */
 537 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev)
 538 {
 539         kfree(m2m_dev);
 540 }
 541 EXPORT_SYMBOL_GPL(v4l2_m2m_release);
 542
 543 /**
 544  * v4l2_m2m_ctx_init() - allocate and initialize a m2m context
 545  * @priv - driver's instance private data
 546  * @m2m_dev - a previously initialized m2m_dev struct
 547  * @vq_init - a callback for queue type-specific initialization function to be
 548  * used for initializing videobuf_queues
 549  *
 550  * Usually called from driver's open() function.
 551  */
 552 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
 553                 void *drv_priv,
 554                 int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq))
 555 {
 556         struct v4l2_m2m_ctx *m2m_ctx;
 557         struct v4l2_m2m_queue_ctx *out_q_ctx, *cap_q_ctx;
 558         int ret;
 559
 560         m2m_ctx = kzalloc(sizeof *m2m_ctx, GFP_KERNEL);
 561         if (!m2m_ctx)
 562                 return ERR_PTR(-ENOMEM);
 563
 564         m2m_ctx->priv = drv_priv;
 565         m2m_ctx->m2m_dev = m2m_dev;
 566         init_waitqueue_head(&m2m_ctx->finished);
 567
 568         out_q_ctx = &m2m_ctx->out_q_ctx;
 569         cap_q_ctx = &m2m_ctx->cap_q_ctx;
 570
 571         INIT_LIST_HEAD(&out_q_ctx->rdy_queue);
 572         INIT_LIST_HEAD(&cap_q_ctx->rdy_queue);
 573         spin_lock_init(&out_q_ctx->rdy_spinlock);
 574         spin_lock_init(&cap_q_ctx->rdy_spinlock);
 575
 576         INIT_LIST_HEAD(&m2m_ctx->queue);
 577
 578         ret = queue_init(drv_priv, &out_q_ctx->q, &cap_q_ctx->q);
 579
 580         if (ret)
 581                 goto err;
 582
 583         return m2m_ctx;
 584 err:
 585         kfree(m2m_ctx);
 586         return ERR_PTR(ret);
 587 }
 588 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_init);
 589
 590 /**
 591  * v4l2_m2m_ctx_release() - release m2m context
 592  *
 593  * Usually called from driver's release() function.
 594  */
 595 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx)
 596 {
 597         struct v4l2_m2m_dev *m2m_dev;
 598         unsigned long flags;
 599
 600         m2m_dev = m2m_ctx->m2m_dev;
 601
 602         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 603         if (m2m_ctx->job_flags & TRANS_RUNNING) {
 604                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 605                 m2m_dev->m2m_ops->job_abort(m2m_ctx->priv);
 606                 dprintk("m2m_ctx %p running, will wait to complete", m2m_ctx);
 607                 wait_event(m2m_ctx->finished, !(m2m_ctx->job_flags & TRANS_RUNNING));
 608         } else if (m2m_ctx->job_flags & TRANS_QUEUED) {
 609                 list_del(&m2m_ctx->queue);
 610                 m2m_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
 611                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 612                 dprintk("m2m_ctx: %p had been on queue and was removed\n",
 613                         m2m_ctx);
 614         } else {
 615                 /* Do nothing, was not on queue/running */
 616                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 617         }
 618
 619         vb2_queue_release(&m2m_ctx->cap_q_ctx.q);
 620         vb2_queue_release(&m2m_ctx->out_q_ctx.q);
 621
 622         kfree(m2m_ctx);
 623 }
 624 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_release);
 625
 626 /**
 627  * v4l2_m2m_buf_queue() - add a buffer to the proper ready buffers list.
 628  *
 629  * Call from buf_queue(), videobuf_queue_ops callback.
 630  */
 631 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct vb2_buffer *vb)
 632 {
 633         struct v4l2_m2m_buffer *b = container_of(vb, struct v4l2_m2m_buffer, vb);
 634         struct v4l2_m2m_queue_ctx *q_ctx;
 635         unsigned long flags;
 636
 637         q_ctx = get_queue_ctx(m2m_ctx, vb->vb2_queue->type);
 638         if (!q_ctx)
 639                 return;
 640
 641         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 642         list_add_tail(&b->list, &q_ctx->rdy_queue);
 643         q_ctx->num_rdy++;
 644         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 645 }
 646 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);
 647