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