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, <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         const 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_first_entry(&q_ctx->rdy_queue, 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_first_entry(&q_ctx->rdy_queue, 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_first_entry(&m2m_dev->job_queue,
 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         spin_lock_irqsave(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags);
 234         if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)) {
 235                 spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags);
 236                 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
 237                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 238                 dprintk("No output buffers available\n");
 239                 return;
 240         }
 241         spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags);
 242         spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
 243
 244         if (m2m_dev->m2m_ops->job_ready
 245                 && (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) {
 246                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 247                 dprintk("Driver not ready\n");
 248                 return;
 249         }
 250
 251         list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue);
 252         m2m_ctx->job_flags |= TRANS_QUEUED;
 253
 254         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 255
 256         v4l2_m2m_try_run(m2m_dev);
 257 }
 258
 259 /**
 260  * v4l2_m2m_job_finish() - inform the framework that a job has been finished
 261  * and have it clean up
 262  *
 263  * Called by a driver to yield back the device after it has finished with it.
 264  * Should be called as soon as possible after reaching a state which allows
 265  * other instances to take control of the device.
 266  *
 267  * This function has to be called only after device_run() callback has been
 268  * called on the driver. To prevent recursion, it should not be called directly
 269  * from the device_run() callback though.
 270  */
 271 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
 272                          struct v4l2_m2m_ctx *m2m_ctx)
 273 {
 274         unsigned long flags;
 275
 276         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 277         if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) {
 278                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 279                 dprintk("Called by an instance not currently running\n");
 280                 return;
 281         }
 282
 283         list_del(&m2m_dev->curr_ctx->queue);
 284         m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
 285         wake_up(&m2m_dev->curr_ctx->finished);
 286         m2m_dev->curr_ctx = NULL;
 287
 288         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 289
 290         /* This instance might have more buffers ready, but since we do not
 291          * allow more than one job on the job_queue per instance, each has
 292          * to be scheduled separately after the previous one finishes. */
 293         v4l2_m2m_try_schedule(m2m_ctx);
 294         v4l2_m2m_try_run(m2m_dev);
 295 }
 296 EXPORT_SYMBOL(v4l2_m2m_job_finish);
 297
 298 /**
 299  * v4l2_m2m_reqbufs() - multi-queue-aware REQBUFS multiplexer
 300  */
 301 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 302                      struct v4l2_requestbuffers *reqbufs)
 303 {
 304         struct vb2_queue *vq;
 305
 306         vq = v4l2_m2m_get_vq(m2m_ctx, reqbufs->type);
 307         return vb2_reqbufs(vq, reqbufs);
 308 }
 309 EXPORT_SYMBOL_GPL(v4l2_m2m_reqbufs);
 310
 311 /**
 312  * v4l2_m2m_querybuf() - multi-queue-aware QUERYBUF multiplexer
 313  *
 314  * See v4l2_m2m_mmap() documentation for details.
 315  */
 316 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 317                       struct v4l2_buffer *buf)
 318 {
 319         struct vb2_queue *vq;
 320         int ret = 0;
 321         unsigned int i;
 322
 323         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 324         ret = vb2_querybuf(vq, buf);
 325
 326         /* Adjust MMAP memory offsets for the CAPTURE queue */
 327         if (buf->memory == V4L2_MEMORY_MMAP && !V4L2_TYPE_IS_OUTPUT(vq->type)) {
 328                 if (V4L2_TYPE_IS_MULTIPLANAR(vq->type)) {
 329                         for (i = 0; i < buf->length; ++i)
 330                                 buf->m.planes[i].m.mem_offset
 331                                         += DST_QUEUE_OFF_BASE;
 332                 } else {
 333                         buf->m.offset += DST_QUEUE_OFF_BASE;
 334                 }
 335         }
 336
 337         return ret;
 338 }
 339 EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf);
 340
 341 /**
 342  * v4l2_m2m_qbuf() - enqueue a source or destination buffer, depending on
 343  * the type
 344  */
 345 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 346                   struct v4l2_buffer *buf)
 347 {
 348         struct vb2_queue *vq;
 349         int ret;
 350
 351         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 352         ret = vb2_qbuf(vq, buf);
 353         if (!ret)
 354                 v4l2_m2m_try_schedule(m2m_ctx);
 355
 356         return ret;
 357 }
 358 EXPORT_SYMBOL_GPL(v4l2_m2m_qbuf);
 359
 360 /**
 361  * v4l2_m2m_dqbuf() - dequeue a source or destination buffer, depending on
 362  * the type
 363  */
 364 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 365                    struct v4l2_buffer *buf)
 366 {
 367         struct vb2_queue *vq;
 368
 369         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 370         return vb2_dqbuf(vq, buf, file->f_flags & O_NONBLOCK);
 371 }
 372 EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
 373
 374 /**
 375  * v4l2_m2m_create_bufs() - create a source or destination buffer, depending
 376  * on the type
 377  */
 378 int v4l2_m2m_create_bufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 379                          struct v4l2_create_buffers *create)
 380 {
 381         struct vb2_queue *vq;
 382
 383         vq = v4l2_m2m_get_vq(m2m_ctx, create->format.type);
 384         return vb2_create_bufs(vq, create);
 385 }
 386 EXPORT_SYMBOL_GPL(v4l2_m2m_create_bufs);
 387
 388 /**
 389  * v4l2_m2m_expbuf() - export a source or destination buffer, depending on
 390  * the type
 391  */
 392 int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 393                   struct v4l2_exportbuffer *eb)
 394 {
 395         struct vb2_queue *vq;
 396
 397         vq = v4l2_m2m_get_vq(m2m_ctx, eb->type);
 398         return vb2_expbuf(vq, eb);
 399 }
 400 EXPORT_SYMBOL_GPL(v4l2_m2m_expbuf);
 401 /**
 402  * v4l2_m2m_streamon() - turn on streaming for a video queue
 403  */
 404 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 405                       enum v4l2_buf_type type)
 406 {
 407         struct vb2_queue *vq;
 408         int ret;
 409
 410         vq = v4l2_m2m_get_vq(m2m_ctx, type);
 411         ret = vb2_streamon(vq, type);
 412         if (!ret)
 413                 v4l2_m2m_try_schedule(m2m_ctx);
 414
 415         return ret;
 416 }
 417 EXPORT_SYMBOL_GPL(v4l2_m2m_streamon);
 418
 419 /**
 420  * v4l2_m2m_streamoff() - turn off streaming for a video queue
 421  */
 422 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 423                        enum v4l2_buf_type type)
 424 {
 425         struct v4l2_m2m_dev *m2m_dev;
 426         struct v4l2_m2m_queue_ctx *q_ctx;
 427         unsigned long flags_job, flags;
 428         int ret;
 429
 430         q_ctx = get_queue_ctx(m2m_ctx, type);
 431         ret = vb2_streamoff(&q_ctx->q, type);
 432         if (ret)
 433                 return ret;
 434
 435         m2m_dev = m2m_ctx->m2m_dev;
 436         spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
 437         /* We should not be scheduled anymore, since we're dropping a queue. */
 438         INIT_LIST_HEAD(&m2m_ctx->queue);
 439         m2m_ctx->job_flags = 0;
 440
 441         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 442         /* Drop queue, since streamoff returns device to the same state as after
 443          * calling reqbufs. */
 444         INIT_LIST_HEAD(&q_ctx->rdy_queue);
 445         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 446
 447         if (m2m_dev->curr_ctx == m2m_ctx) {
 448                 m2m_dev->curr_ctx = NULL;
 449                 wake_up(&m2m_ctx->finished);
 450         }
 451         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 452
 453         return 0;
 454 }
 455 EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff);
 456
 457 /**
 458  * v4l2_m2m_poll() - poll replacement, for destination buffers only
 459  *
 460  * Call from the driver's poll() function. Will poll both queues. If a buffer
 461  * is available to dequeue (with dqbuf) from the source queue, this will
 462  * indicate that a non-blocking write can be performed, while read will be
 463  * returned in case of the destination queue.
 464  */
 465 unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 466                            struct poll_table_struct *wait)
 467 {
 468         struct video_device *vfd = video_devdata(file);
 469         unsigned long req_events = poll_requested_events(wait);
 470         struct vb2_queue *src_q, *dst_q;
 471         struct vb2_buffer *src_vb = NULL, *dst_vb = NULL;
 472         unsigned int rc = 0;
 473         unsigned long flags;
 474
 475         if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
 476                 struct v4l2_fh *fh = file->private_data;
 477
 478                 if (v4l2_event_pending(fh))
 479                         rc = POLLPRI;
 480                 else if (req_events & POLLPRI)
 481                         poll_wait(file, &fh->wait, wait);
 482                 if (!(req_events & (POLLOUT | POLLWRNORM | POLLIN | POLLRDNORM)))
 483                         return rc;
 484         }
 485
 486         src_q = v4l2_m2m_get_src_vq(m2m_ctx);
 487         dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
 488
 489         /*
 490          * There has to be at least one buffer queued on each queued_list, which
 491          * means either in driver already or waiting for driver to claim it
 492          * and start processing.
 493          */
 494         if ((!src_q->streaming || list_empty(&src_q->queued_list))
 495                 && (!dst_q->streaming || list_empty(&dst_q->queued_list))) {
 496                 rc |= POLLERR;
 497                 goto end;
 498         }
 499
 500         if (m2m_ctx->m2m_dev->m2m_ops->unlock)
 501                 m2m_ctx->m2m_dev->m2m_ops->unlock(m2m_ctx->priv);
 502
 503         if (list_empty(&src_q->done_list))
 504                 poll_wait(file, &src_q->done_wq, wait);
 505         if (list_empty(&dst_q->done_list))
 506                 poll_wait(file, &dst_q->done_wq, wait);
 507
 508         if (m2m_ctx->m2m_dev->m2m_ops->lock)
 509                 m2m_ctx->m2m_dev->m2m_ops->lock(m2m_ctx->priv);
 510
 511         spin_lock_irqsave(&src_q->done_lock, flags);
 512         if (!list_empty(&src_q->done_list))
 513                 src_vb = list_first_entry(&src_q->done_list, struct vb2_buffer,
 514                                                 done_entry);
 515         if (src_vb && (src_vb->state == VB2_BUF_STATE_DONE
 516                         || src_vb->state == VB2_BUF_STATE_ERROR))
 517                 rc |= POLLOUT | POLLWRNORM;
 518         spin_unlock_irqrestore(&src_q->done_lock, flags);
 519
 520         spin_lock_irqsave(&dst_q->done_lock, flags);
 521         if (!list_empty(&dst_q->done_list))
 522                 dst_vb = list_first_entry(&dst_q->done_list, struct vb2_buffer,
 523                                                 done_entry);
 524         if (dst_vb && (dst_vb->state == VB2_BUF_STATE_DONE
 525                         || dst_vb->state == VB2_BUF_STATE_ERROR))
 526                 rc |= POLLIN | POLLRDNORM;
 527         spin_unlock_irqrestore(&dst_q->done_lock, flags);
 528
 529 end:
 530         return rc;
 531 }
 532 EXPORT_SYMBOL_GPL(v4l2_m2m_poll);
 533
 534 /**
 535  * v4l2_m2m_mmap() - source and destination queues-aware mmap multiplexer
 536  *
 537  * Call from driver's mmap() function. Will handle mmap() for both queues
 538  * seamlessly for videobuffer, which will receive normal per-queue offsets and
 539  * proper videobuf queue pointers. The differentiation is made outside videobuf
 540  * by adding a predefined offset to buffers from one of the queues and
 541  * subtracting it before passing it back to videobuf. Only drivers (and
 542  * thus applications) receive modified offsets.
 543  */
 544 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 545                          struct vm_area_struct *vma)
 546 {
 547         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 548         struct vb2_queue *vq;
 549
 550         if (offset < DST_QUEUE_OFF_BASE) {
 551                 vq = v4l2_m2m_get_src_vq(m2m_ctx);
 552         } else {
 553                 vq = v4l2_m2m_get_dst_vq(m2m_ctx);
 554                 vma->vm_pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT);
 555         }
 556
 557         return vb2_mmap(vq, vma);
 558 }
 559 EXPORT_SYMBOL(v4l2_m2m_mmap);
 560
 561 /**
 562  * v4l2_m2m_init() - initialize per-driver m2m data
 563  *
 564  * Usually called from driver's probe() function.
 565  */
 566 struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops)
 567 {
 568         struct v4l2_m2m_dev *m2m_dev;
 569
 570         if (!m2m_ops || WARN_ON(!m2m_ops->device_run) ||
 571                         WARN_ON(!m2m_ops->job_abort))
 572                 return ERR_PTR(-EINVAL);
 573
 574         m2m_dev = kzalloc(sizeof *m2m_dev, GFP_KERNEL);
 575         if (!m2m_dev)
 576                 return ERR_PTR(-ENOMEM);
 577
 578         m2m_dev->curr_ctx = NULL;
 579         m2m_dev->m2m_ops = m2m_ops;
 580         INIT_LIST_HEAD(&m2m_dev->job_queue);
 581         spin_lock_init(&m2m_dev->job_spinlock);
 582
 583         return m2m_dev;
 584 }
 585 EXPORT_SYMBOL_GPL(v4l2_m2m_init);
 586
 587 /**
 588  * v4l2_m2m_release() - cleans up and frees a m2m_dev structure
 589  *
 590  * Usually called from driver's remove() function.
 591  */
 592 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev)
 593 {
 594         kfree(m2m_dev);
 595 }
 596 EXPORT_SYMBOL_GPL(v4l2_m2m_release);
 597
 598 /**
 599  * v4l2_m2m_ctx_init() - allocate and initialize a m2m context
 600  * @priv - driver's instance private data
 601  * @m2m_dev - a previously initialized m2m_dev struct
 602  * @vq_init - a callback for queue type-specific initialization function to be
 603  * used for initializing videobuf_queues
 604  *
 605  * Usually called from driver's open() function.
 606  */
 607 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
 608                 void *drv_priv,
 609                 int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq))
 610 {
 611         struct v4l2_m2m_ctx *m2m_ctx;
 612         struct v4l2_m2m_queue_ctx *out_q_ctx, *cap_q_ctx;
 613         int ret;
 614
 615         m2m_ctx = kzalloc(sizeof *m2m_ctx, GFP_KERNEL);
 616         if (!m2m_ctx)
 617                 return ERR_PTR(-ENOMEM);
 618
 619         m2m_ctx->priv = drv_priv;
 620         m2m_ctx->m2m_dev = m2m_dev;
 621         init_waitqueue_head(&m2m_ctx->finished);
 622
 623         out_q_ctx = &m2m_ctx->out_q_ctx;
 624         cap_q_ctx = &m2m_ctx->cap_q_ctx;
 625
 626         INIT_LIST_HEAD(&out_q_ctx->rdy_queue);
 627         INIT_LIST_HEAD(&cap_q_ctx->rdy_queue);
 628         spin_lock_init(&out_q_ctx->rdy_spinlock);
 629         spin_lock_init(&cap_q_ctx->rdy_spinlock);
 630
 631         INIT_LIST_HEAD(&m2m_ctx->queue);
 632
 633         ret = queue_init(drv_priv, &out_q_ctx->q, &cap_q_ctx->q);
 634
 635         if (ret)
 636                 goto err;
 637
 638         return m2m_ctx;
 639 err:
 640         kfree(m2m_ctx);
 641         return ERR_PTR(ret);
 642 }
 643 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_init);
 644
 645 /**
 646  * v4l2_m2m_ctx_release() - release m2m context
 647  *
 648  * Usually called from driver's release() function.
 649  */
 650 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx)
 651 {
 652         struct v4l2_m2m_dev *m2m_dev;
 653         unsigned long flags;
 654
 655         m2m_dev = m2m_ctx->m2m_dev;
 656
 657         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 658         if (m2m_ctx->job_flags & TRANS_RUNNING) {
 659                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 660                 m2m_dev->m2m_ops->job_abort(m2m_ctx->priv);
 661                 dprintk("m2m_ctx %p running, will wait to complete", m2m_ctx);
 662                 wait_event(m2m_ctx->finished, !(m2m_ctx->job_flags & TRANS_RUNNING));
 663         } else if (m2m_ctx->job_flags & TRANS_QUEUED) {
 664                 list_del(&m2m_ctx->queue);
 665                 m2m_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
 666                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 667                 dprintk("m2m_ctx: %p had been on queue and was removed\n",
 668                         m2m_ctx);
 669         } else {
 670                 /* Do nothing, was not on queue/running */
 671                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 672         }
 673
 674         vb2_queue_release(&m2m_ctx->cap_q_ctx.q);
 675         vb2_queue_release(&m2m_ctx->out_q_ctx.q);
 676
 677         kfree(m2m_ctx);
 678 }
 679 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_release);
 680
 681 /**
 682  * v4l2_m2m_buf_queue() - add a buffer to the proper ready buffers list.
 683  *
 684  * Call from buf_queue(), videobuf_queue_ops callback.
 685  */
 686 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct vb2_buffer *vb)
 687 {
 688         struct v4l2_m2m_buffer *b = container_of(vb, struct v4l2_m2m_buffer, vb);
 689         struct v4l2_m2m_queue_ctx *q_ctx;
 690         unsigned long flags;
 691
 692         q_ctx = get_queue_ctx(m2m_ctx, vb->vb2_queue->type);
 693         if (!q_ctx)
 694                 return;
 695
 696         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 697         list_add_tail(&b->list, &q_ctx->rdy_queue);
 698         q_ctx->num_rdy++;
 699         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 700 }
 701 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);
 702