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
  23 MODULE_DESCRIPTION("Mem to mem device framework for videobuf");
  24 MODULE_AUTHOR("Pawel Osciak, <pawel@osciak.com>");
  25 MODULE_LICENSE("GPL");
  26
  27 static bool debug;
  28 module_param(debug, bool, 0644);
  29
  30 #define dprintk(fmt, arg...)                                            \
  31         do {                                                            \
  32                 if (debug)                                              \
  33                         printk(KERN_DEBUG "%s: " fmt, __func__, ## arg);\
  34         } while (0)
  35
  36
  37 /* Instance is already queued on the job_queue */
  38 #define TRANS_QUEUED            (1 << 0)
  39 /* Instance is currently running in hardware */
  40 #define TRANS_RUNNING           (1 << 1)
  41
  42
  43 /* Offset base for buffers on the destination queue - used to distinguish
  44  * between source and destination buffers when mmapping - they receive the same
  45  * offsets but for different queues */
  46 #define DST_QUEUE_OFF_BASE      (1 << 30)
  47
  48
  49 /**
  50  * struct v4l2_m2m_dev - per-device context
  51  * @curr_ctx:           currently running instance
  52  * @job_queue:          instances queued to run
  53  * @job_spinlock:       protects job_queue
  54  * @m2m_ops:            driver callbacks
  55  */
  56 struct v4l2_m2m_dev {
  57         struct v4l2_m2m_ctx     *curr_ctx;
  58
  59         struct list_head        job_queue;
  60         spinlock_t              job_spinlock;
  61
  62         struct v4l2_m2m_ops     *m2m_ops;
  63 };
  64
  65 static struct v4l2_m2m_queue_ctx *get_queue_ctx(struct v4l2_m2m_ctx *m2m_ctx,
  66                                                 enum v4l2_buf_type type)
  67 {
  68         if (V4L2_TYPE_IS_OUTPUT(type))
  69                 return &m2m_ctx->out_q_ctx;
  70         else
  71                 return &m2m_ctx->cap_q_ctx;
  72 }
  73
  74 /**
  75  * v4l2_m2m_get_vq() - return vb2_queue for the given type
  76  */
  77 struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
  78                                        enum v4l2_buf_type type)
  79 {
  80         struct v4l2_m2m_queue_ctx *q_ctx;
  81
  82         q_ctx = get_queue_ctx(m2m_ctx, type);
  83         if (!q_ctx)
  84                 return NULL;
  85
  86         return &q_ctx->q;
  87 }
  88 EXPORT_SYMBOL(v4l2_m2m_get_vq);
  89
  90 /**
  91  * v4l2_m2m_next_buf() - return next buffer from the list of ready buffers
  92  */
  93 void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx)
  94 {
  95         struct v4l2_m2m_buffer *b = NULL;
  96         unsigned long flags;
  97
  98         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
  99
 100         if (list_empty(&q_ctx->rdy_queue)) {
 101                 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 102                 return NULL;
 103         }
 104
 105         b = list_entry(q_ctx->rdy_queue.next, struct v4l2_m2m_buffer, list);
 106         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 107         return &b->vb;
 108 }
 109 EXPORT_SYMBOL_GPL(v4l2_m2m_next_buf);
 110
 111 /**
 112  * v4l2_m2m_buf_remove() - take off a buffer from the list of ready buffers and
 113  * return it
 114  */
 115 void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx)
 116 {
 117         struct v4l2_m2m_buffer *b = NULL;
 118         unsigned long flags;
 119
 120         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 121         if (list_empty(&q_ctx->rdy_queue)) {
 122                 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 123                 return NULL;
 124         }
 125         b = list_entry(q_ctx->rdy_queue.next, struct v4l2_m2m_buffer, list);
 126         list_del(&b->list);
 127         q_ctx->num_rdy--;
 128         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 129
 130         return &b->vb;
 131 }
 132 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove);
 133
 134 /*
 135  * Scheduling handlers
 136  */
 137
 138 /**
 139  * v4l2_m2m_get_curr_priv() - return driver private data for the currently
 140  * running instance or NULL if no instance is running
 141  */
 142 void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev)
 143 {
 144         unsigned long flags;
 145         void *ret = NULL;
 146
 147         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 148         if (m2m_dev->curr_ctx)
 149                 ret = m2m_dev->curr_ctx->priv;
 150         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 151
 152         return ret;
 153 }
 154 EXPORT_SYMBOL(v4l2_m2m_get_curr_priv);
 155
 156 /**
 157  * v4l2_m2m_try_run() - select next job to perform and run it if possible
 158  *
 159  * Get next transaction (if present) from the waiting jobs list and run it.
 160  */
 161 static void v4l2_m2m_try_run(struct v4l2_m2m_dev *m2m_dev)
 162 {
 163         unsigned long flags;
 164
 165         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 166         if (NULL != m2m_dev->curr_ctx) {
 167                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 168                 dprintk("Another instance is running, won't run now\n");
 169                 return;
 170         }
 171
 172         if (list_empty(&m2m_dev->job_queue)) {
 173                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 174                 dprintk("No job pending\n");
 175                 return;
 176         }
 177
 178         m2m_dev->curr_ctx = list_entry(m2m_dev->job_queue.next,
 179                                    struct v4l2_m2m_ctx, queue);
 180         m2m_dev->curr_ctx->job_flags |= TRANS_RUNNING;
 181         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 182
 183         m2m_dev->m2m_ops->device_run(m2m_dev->curr_ctx->priv);
 184 }
 185
 186 /**
 187  * v4l2_m2m_try_schedule() - check whether an instance is ready to be added to
 188  * the pending job queue and add it if so.
 189  * @m2m_ctx:    m2m context assigned to the instance to be checked
 190  *
 191  * There are three basic requirements an instance has to meet to be able to run:
 192  * 1) at least one source buffer has to be queued,
 193  * 2) at least one destination buffer has to be queued,
 194  * 3) streaming has to be on.
 195  *
 196  * There may also be additional, custom requirements. In such case the driver
 197  * should supply a custom callback (job_ready in v4l2_m2m_ops) that should
 198  * return 1 if the instance is ready.
 199  * An example of the above could be an instance that requires more than one
 200  * src/dst buffer per transaction.
 201  */
 202 static void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx)
 203 {
 204         struct v4l2_m2m_dev *m2m_dev;
 205         unsigned long flags_job, flags;
 206
 207         m2m_dev = m2m_ctx->m2m_dev;
 208         dprintk("Trying to schedule a job for m2m_ctx: %p\n", m2m_ctx);
 209
 210         if (!m2m_ctx->out_q_ctx.q.streaming
 211             || !m2m_ctx->cap_q_ctx.q.streaming) {
 212                 dprintk("Streaming needs to be on for both queues\n");
 213                 return;
 214         }
 215
 216         spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
 217         if (m2m_ctx->job_flags & TRANS_QUEUED) {
 218                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 219                 dprintk("On job queue already\n");
 220                 return;
 221         }
 222
 223         spin_lock_irqsave(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
 224         if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue)) {
 225                 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
 226                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 227                 dprintk("No input buffers available\n");
 228                 return;
 229         }
 230         if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)) {
 231                 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
 232                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 233                 dprintk("No output buffers available\n");
 234                 return;
 235         }
 236         spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
 237
 238         if (m2m_dev->m2m_ops->job_ready
 239                 && (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) {
 240                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 241                 dprintk("Driver not ready\n");
 242                 return;
 243         }
 244
 245         list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue);
 246         m2m_ctx->job_flags |= TRANS_QUEUED;
 247
 248         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 249
 250         v4l2_m2m_try_run(m2m_dev);
 251 }
 252
 253 /**
 254  * v4l2_m2m_job_finish() - inform the framework that a job has been finished
 255  * and have it clean up
 256  *
 257  * Called by a driver to yield back the device after it has finished with it.
 258  * Should be called as soon as possible after reaching a state which allows
 259  * other instances to take control of the device.
 260  *
 261  * This function has to be called only after device_run() callback has been
 262  * called on the driver. To prevent recursion, it should not be called directly
 263  * from the device_run() callback though.
 264  */
 265 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
 266                          struct v4l2_m2m_ctx *m2m_ctx)
 267 {
 268         unsigned long flags;
 269
 270         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 271         if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) {
 272                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 273                 dprintk("Called by an instance not currently running\n");
 274                 return;
 275         }
 276
 277         list_del(&m2m_dev->curr_ctx->queue);
 278         m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
 279         wake_up(&m2m_dev->curr_ctx->finished);
 280         m2m_dev->curr_ctx = NULL;
 281
 282         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 283
 284         /* This instance might have more buffers ready, but since we do not
 285          * allow more than one job on the job_queue per instance, each has
 286          * to be scheduled separately after the previous one finishes. */
 287         v4l2_m2m_try_schedule(m2m_ctx);
 288         v4l2_m2m_try_run(m2m_dev);
 289 }
 290 EXPORT_SYMBOL(v4l2_m2m_job_finish);
 291
 292 /**
 293  * v4l2_m2m_reqbufs() - multi-queue-aware REQBUFS multiplexer
 294  */
 295 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 296                      struct v4l2_requestbuffers *reqbufs)
 297 {
 298         struct vb2_queue *vq;
 299
 300         vq = v4l2_m2m_get_vq(m2m_ctx, reqbufs->type);
 301         return vb2_reqbufs(vq, reqbufs);
 302 }
 303 EXPORT_SYMBOL_GPL(v4l2_m2m_reqbufs);
 304
 305 /**
 306  * v4l2_m2m_querybuf() - multi-queue-aware QUERYBUF multiplexer
 307  *
 308  * See v4l2_m2m_mmap() documentation for details.
 309  */
 310 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 311                       struct v4l2_buffer *buf)
 312 {
 313         struct vb2_queue *vq;
 314         int ret = 0;
 315         unsigned int i;
 316
 317         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 318         ret = vb2_querybuf(vq, buf);
 319
 320         /* Adjust MMAP memory offsets for the CAPTURE queue */
 321         if (buf->memory == V4L2_MEMORY_MMAP && !V4L2_TYPE_IS_OUTPUT(vq->type)) {
 322                 if (V4L2_TYPE_IS_MULTIPLANAR(vq->type)) {
 323                         for (i = 0; i < buf->length; ++i)
 324                                 buf->m.planes[i].m.mem_offset
 325                                         += DST_QUEUE_OFF_BASE;
 326                 } else {
 327                         buf->m.offset += DST_QUEUE_OFF_BASE;
 328                 }
 329         }
 330
 331         return ret;
 332 }
 333 EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf);
 334
 335 /**
 336  * v4l2_m2m_qbuf() - enqueue a source or destination buffer, depending on
 337  * the type
 338  */
 339 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 340                   struct v4l2_buffer *buf)
 341 {
 342         struct vb2_queue *vq;
 343         int ret;
 344
 345         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 346         ret = vb2_qbuf(vq, buf);
 347         if (!ret)
 348                 v4l2_m2m_try_schedule(m2m_ctx);
 349
 350         return ret;
 351 }
 352 EXPORT_SYMBOL_GPL(v4l2_m2m_qbuf);
 353
 354 /**
 355  * v4l2_m2m_dqbuf() - dequeue a source or destination buffer, depending on
 356  * the type
 357  */
 358 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 359                    struct v4l2_buffer *buf)
 360 {
 361         struct vb2_queue *vq;
 362
 363         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 364         return vb2_dqbuf(vq, buf, file->f_flags & O_NONBLOCK);
 365 }
 366 EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
 367
 368 /**
 369  * v4l2_m2m_streamon() - turn on streaming for a video queue
 370  */
 371 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 372                       enum v4l2_buf_type type)
 373 {
 374         struct vb2_queue *vq;
 375         int ret;
 376
 377         vq = v4l2_m2m_get_vq(m2m_ctx, type);
 378         ret = vb2_streamon(vq, type);
 379         if (!ret)
 380                 v4l2_m2m_try_schedule(m2m_ctx);
 381
 382         return ret;
 383 }
 384 EXPORT_SYMBOL_GPL(v4l2_m2m_streamon);
 385
 386 /**
 387  * v4l2_m2m_streamoff() - turn off streaming for a video queue
 388  */
 389 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 390                        enum v4l2_buf_type type)
 391 {
 392         struct vb2_queue *vq;
 393
 394         vq = v4l2_m2m_get_vq(m2m_ctx, type);
 395         return vb2_streamoff(vq, type);
 396 }
 397 EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff);
 398
 399 /**
 400  * v4l2_m2m_poll() - poll replacement, for destination buffers only
 401  *
 402  * Call from the driver's poll() function. Will poll both queues. If a buffer
 403  * is available to dequeue (with dqbuf) from the source queue, this will
 404  * indicate that a non-blocking write can be performed, while read will be
 405  * returned in case of the destination queue.
 406  */
 407 unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 408                            struct poll_table_struct *wait)
 409 {
 410         struct vb2_queue *src_q, *dst_q;
 411         struct vb2_buffer *src_vb = NULL, *dst_vb = NULL;
 412         unsigned int rc = 0;
 413         unsigned long flags;
 414
 415         src_q = v4l2_m2m_get_src_vq(m2m_ctx);
 416         dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
 417
 418         /*
 419          * There has to be at least one buffer queued on each queued_list, which
 420          * means either in driver already or waiting for driver to claim it
 421          * and start processing.
 422          */
 423         if ((!src_q->streaming || list_empty(&src_q->queued_list))
 424                 && (!dst_q->streaming || list_empty(&dst_q->queued_list))) {
 425                 rc = POLLERR;
 426                 goto end;
 427         }
 428
 429         if (m2m_ctx->m2m_dev->m2m_ops->unlock)
 430                 m2m_ctx->m2m_dev->m2m_ops->unlock(m2m_ctx->priv);
 431
 432         poll_wait(file, &src_q->done_wq, wait);
 433         poll_wait(file, &dst_q->done_wq, wait);
 434
 435         if (m2m_ctx->m2m_dev->m2m_ops->lock)
 436                 m2m_ctx->m2m_dev->m2m_ops->lock(m2m_ctx->priv);
 437
 438         spin_lock_irqsave(&src_q->done_lock, flags);
 439         if (!list_empty(&src_q->done_list))
 440                 src_vb = list_first_entry(&src_q->done_list, struct vb2_buffer,
 441                                                 done_entry);
 442         if (src_vb && (src_vb->state == VB2_BUF_STATE_DONE
 443                         || src_vb->state == VB2_BUF_STATE_ERROR))
 444                 rc |= POLLOUT | POLLWRNORM;
 445         spin_unlock_irqrestore(&src_q->done_lock, flags);
 446
 447         spin_lock_irqsave(&dst_q->done_lock, flags);
 448         if (!list_empty(&dst_q->done_list))
 449                 dst_vb = list_first_entry(&dst_q->done_list, struct vb2_buffer,
 450                                                 done_entry);
 451         if (dst_vb && (dst_vb->state == VB2_BUF_STATE_DONE
 452                         || dst_vb->state == VB2_BUF_STATE_ERROR))
 453                 rc |= POLLIN | POLLRDNORM;
 454         spin_unlock_irqrestore(&dst_q->done_lock, flags);
 455
 456 end:
 457         return rc;
 458 }
 459 EXPORT_SYMBOL_GPL(v4l2_m2m_poll);
 460
 461 /**
 462  * v4l2_m2m_mmap() - source and destination queues-aware mmap multiplexer
 463  *
 464  * Call from driver's mmap() function. Will handle mmap() for both queues
 465  * seamlessly for videobuffer, which will receive normal per-queue offsets and
 466  * proper videobuf queue pointers. The differentiation is made outside videobuf
 467  * by adding a predefined offset to buffers from one of the queues and
 468  * subtracting it before passing it back to videobuf. Only drivers (and
 469  * thus applications) receive modified offsets.
 470  */
 471 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 472                          struct vm_area_struct *vma)
 473 {
 474         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 475         struct vb2_queue *vq;
 476
 477         if (offset < DST_QUEUE_OFF_BASE) {
 478                 vq = v4l2_m2m_get_src_vq(m2m_ctx);
 479         } else {
 480                 vq = v4l2_m2m_get_dst_vq(m2m_ctx);
 481                 vma->vm_pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT);
 482         }
 483
 484         return vb2_mmap(vq, vma);
 485 }
 486 EXPORT_SYMBOL(v4l2_m2m_mmap);
 487
 488 /**
 489  * v4l2_m2m_init() - initialize per-driver m2m data
 490  *
 491  * Usually called from driver's probe() function.
 492  */
 493 struct v4l2_m2m_dev *v4l2_m2m_init(struct v4l2_m2m_ops *m2m_ops)
 494 {
 495         struct v4l2_m2m_dev *m2m_dev;
 496
 497         if (!m2m_ops)
 498                 return ERR_PTR(-EINVAL);
 499
 500         BUG_ON(!m2m_ops->device_run);
 501         BUG_ON(!m2m_ops->job_abort);
 502
 503         m2m_dev = kzalloc(sizeof *m2m_dev, GFP_KERNEL);
 504         if (!m2m_dev)
 505                 return ERR_PTR(-ENOMEM);
 506
 507         m2m_dev->curr_ctx = NULL;
 508         m2m_dev->m2m_ops = m2m_ops;
 509         INIT_LIST_HEAD(&m2m_dev->job_queue);
 510         spin_lock_init(&m2m_dev->job_spinlock);
 511
 512         return m2m_dev;
 513 }
 514 EXPORT_SYMBOL_GPL(v4l2_m2m_init);
 515
 516 /**
 517  * v4l2_m2m_release() - cleans up and frees a m2m_dev structure
 518  *
 519  * Usually called from driver's remove() function.
 520  */
 521 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev)
 522 {
 523         kfree(m2m_dev);
 524 }
 525 EXPORT_SYMBOL_GPL(v4l2_m2m_release);
 526
 527 /**
 528  * v4l2_m2m_ctx_init() - allocate and initialize a m2m context
 529  * @priv - driver's instance private data
 530  * @m2m_dev - a previously initialized m2m_dev struct
 531  * @vq_init - a callback for queue type-specific initialization function to be
 532  * used for initializing videobuf_queues
 533  *
 534  * Usually called from driver's open() function.
 535  */
 536 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
 537                 void *drv_priv,
 538                 int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq))
 539 {
 540         struct v4l2_m2m_ctx *m2m_ctx;
 541         struct v4l2_m2m_queue_ctx *out_q_ctx, *cap_q_ctx;
 542         int ret;
 543
 544         m2m_ctx = kzalloc(sizeof *m2m_ctx, GFP_KERNEL);
 545         if (!m2m_ctx)
 546                 return ERR_PTR(-ENOMEM);
 547
 548         m2m_ctx->priv = drv_priv;
 549         m2m_ctx->m2m_dev = m2m_dev;
 550         init_waitqueue_head(&m2m_ctx->finished);
 551
 552         out_q_ctx = &m2m_ctx->out_q_ctx;
 553         cap_q_ctx = &m2m_ctx->cap_q_ctx;
 554
 555         INIT_LIST_HEAD(&out_q_ctx->rdy_queue);
 556         INIT_LIST_HEAD(&cap_q_ctx->rdy_queue);
 557         spin_lock_init(&out_q_ctx->rdy_spinlock);
 558         spin_lock_init(&cap_q_ctx->rdy_spinlock);
 559
 560         INIT_LIST_HEAD(&m2m_ctx->queue);
 561
 562         ret = queue_init(drv_priv, &out_q_ctx->q, &cap_q_ctx->q);
 563
 564         if (ret)
 565                 goto err;
 566
 567         return m2m_ctx;
 568 err:
 569         kfree(m2m_ctx);
 570         return ERR_PTR(ret);
 571 }
 572 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_init);
 573
 574 /**
 575  * v4l2_m2m_ctx_release() - release m2m context
 576  *
 577  * Usually called from driver's release() function.
 578  */
 579 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx)
 580 {
 581         struct v4l2_m2m_dev *m2m_dev;
 582         unsigned long flags;
 583
 584         m2m_dev = m2m_ctx->m2m_dev;
 585
 586         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 587         if (m2m_ctx->job_flags & TRANS_RUNNING) {
 588                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 589                 m2m_dev->m2m_ops->job_abort(m2m_ctx->priv);
 590                 dprintk("m2m_ctx %p running, will wait to complete", m2m_ctx);
 591                 wait_event(m2m_ctx->finished, !(m2m_ctx->job_flags & TRANS_RUNNING));
 592         } else if (m2m_ctx->job_flags & TRANS_QUEUED) {
 593                 list_del(&m2m_ctx->queue);
 594                 m2m_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
 595                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 596                 dprintk("m2m_ctx: %p had been on queue and was removed\n",
 597                         m2m_ctx);
 598         } else {
 599                 /* Do nothing, was not on queue/running */
 600                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 601         }
 602
 603         vb2_queue_release(&m2m_ctx->cap_q_ctx.q);
 604         vb2_queue_release(&m2m_ctx->out_q_ctx.q);
 605
 606         kfree(m2m_ctx);
 607 }
 608 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_release);
 609
 610 /**
 611  * v4l2_m2m_buf_queue() - add a buffer to the proper ready buffers list.
 612  *
 613  * Call from buf_queue(), videobuf_queue_ops callback.
 614  */
 615 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct vb2_buffer *vb)
 616 {
 617         struct v4l2_m2m_buffer *b = container_of(vb, struct v4l2_m2m_buffer, vb);
 618         struct v4l2_m2m_queue_ctx *q_ctx;
 619         unsigned long flags;
 620
 621         q_ctx = get_queue_ctx(m2m_ctx, vb->vb2_queue->type);
 622         if (!q_ctx)
 623                 return;
 624
 625         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 626         list_add_tail(&b->list, &q_ctx->rdy_queue);
 627         q_ctx->num_rdy++;
 628         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 629 }
 630 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);
 631