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_out, flags_cap;
 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_out);
 227         if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue)) {
 228                 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock,
 229                                         flags_out);
 230                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 231                 dprintk("No input buffers available\n");
 232                 return;
 233         }
 234         spin_lock_irqsave(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap);
 235         if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)) {
 236                 spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock,
 237                                         flags_cap);
 238                 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock,
 239                                         flags_out);
 240                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 241                 dprintk("No output buffers available\n");
 242                 return;
 243         }
 244         spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap);
 245         spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags_out);
 246
 247         if (m2m_dev->m2m_ops->job_ready
 248                 && (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) {
 249                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 250                 dprintk("Driver not ready\n");
 251                 return;
 252         }
 253
 254         list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue);
 255         m2m_ctx->job_flags |= TRANS_QUEUED;
 256
 257         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 258
 259         v4l2_m2m_try_run(m2m_dev);
 260 }
 261
 262 /**
 263  * v4l2_m2m_job_finish() - inform the framework that a job has been finished
 264  * and have it clean up
 265  *
 266  * Called by a driver to yield back the device after it has finished with it.
 267  * Should be called as soon as possible after reaching a state which allows
 268  * other instances to take control of the device.
 269  *
 270  * This function has to be called only after device_run() callback has been
 271  * called on the driver. To prevent recursion, it should not be called directly
 272  * from the device_run() callback though.
 273  */
 274 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
 275                          struct v4l2_m2m_ctx *m2m_ctx)
 276 {
 277         unsigned long flags;
 278
 279         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 280         if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) {
 281                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 282                 dprintk("Called by an instance not currently running\n");
 283                 return;
 284         }
 285
 286         list_del(&m2m_dev->curr_ctx->queue);
 287         m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
 288         wake_up(&m2m_dev->curr_ctx->finished);
 289         m2m_dev->curr_ctx = NULL;
 290
 291         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 292
 293         /* This instance might have more buffers ready, but since we do not
 294          * allow more than one job on the job_queue per instance, each has
 295          * to be scheduled separately after the previous one finishes. */
 296         v4l2_m2m_try_schedule(m2m_ctx);
 297         v4l2_m2m_try_run(m2m_dev);
 298 }
 299 EXPORT_SYMBOL(v4l2_m2m_job_finish);
 300
 301 /**
 302  * v4l2_m2m_reqbufs() - multi-queue-aware REQBUFS multiplexer
 303  */
 304 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 305                      struct v4l2_requestbuffers *reqbufs)
 306 {
 307         struct vb2_queue *vq;
 308
 309         vq = v4l2_m2m_get_vq(m2m_ctx, reqbufs->type);
 310         return vb2_reqbufs(vq, reqbufs);
 311 }
 312 EXPORT_SYMBOL_GPL(v4l2_m2m_reqbufs);
 313
 314 /**
 315  * v4l2_m2m_querybuf() - multi-queue-aware QUERYBUF multiplexer
 316  *
 317  * See v4l2_m2m_mmap() documentation for details.
 318  */
 319 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 320                       struct v4l2_buffer *buf)
 321 {
 322         struct vb2_queue *vq;
 323         int ret = 0;
 324         unsigned int i;
 325
 326         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 327         ret = vb2_querybuf(vq, buf);
 328
 329         /* Adjust MMAP memory offsets for the CAPTURE queue */
 330         if (buf->memory == V4L2_MEMORY_MMAP && !V4L2_TYPE_IS_OUTPUT(vq->type)) {
 331                 if (V4L2_TYPE_IS_MULTIPLANAR(vq->type)) {
 332                         for (i = 0; i < buf->length; ++i)
 333                                 buf->m.planes[i].m.mem_offset
 334                                         += DST_QUEUE_OFF_BASE;
 335                 } else {
 336                         buf->m.offset += DST_QUEUE_OFF_BASE;
 337                 }
 338         }
 339
 340         return ret;
 341 }
 342 EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf);
 343
 344 /**
 345  * v4l2_m2m_qbuf() - enqueue a source or destination buffer, depending on
 346  * the type
 347  */
 348 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 349                   struct v4l2_buffer *buf)
 350 {
 351         struct vb2_queue *vq;
 352         int ret;
 353
 354         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 355         ret = vb2_qbuf(vq, buf);
 356         if (!ret)
 357                 v4l2_m2m_try_schedule(m2m_ctx);
 358
 359         return ret;
 360 }
 361 EXPORT_SYMBOL_GPL(v4l2_m2m_qbuf);
 362
 363 /**
 364  * v4l2_m2m_dqbuf() - dequeue a source or destination buffer, depending on
 365  * the type
 366  */
 367 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 368                    struct v4l2_buffer *buf)
 369 {
 370         struct vb2_queue *vq;
 371
 372         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 373         return vb2_dqbuf(vq, buf, file->f_flags & O_NONBLOCK);
 374 }
 375 EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
 376
 377 /**
 378  * v4l2_m2m_create_bufs() - create a source or destination buffer, depending
 379  * on the type
 380  */
 381 int v4l2_m2m_create_bufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 382                          struct v4l2_create_buffers *create)
 383 {
 384         struct vb2_queue *vq;
 385
 386         vq = v4l2_m2m_get_vq(m2m_ctx, create->format.type);
 387         return vb2_create_bufs(vq, create);
 388 }
 389 EXPORT_SYMBOL_GPL(v4l2_m2m_create_bufs);
 390
 391 /**
 392  * v4l2_m2m_expbuf() - export a source or destination buffer, depending on
 393  * the type
 394  */
 395 int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 396                   struct v4l2_exportbuffer *eb)
 397 {
 398         struct vb2_queue *vq;
 399
 400         vq = v4l2_m2m_get_vq(m2m_ctx, eb->type);
 401         return vb2_expbuf(vq, eb);
 402 }
 403 EXPORT_SYMBOL_GPL(v4l2_m2m_expbuf);
 404 /**
 405  * v4l2_m2m_streamon() - turn on streaming for a video queue
 406  */
 407 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 408                       enum v4l2_buf_type type)
 409 {
 410         struct vb2_queue *vq;
 411         int ret;
 412
 413         vq = v4l2_m2m_get_vq(m2m_ctx, type);
 414         ret = vb2_streamon(vq, type);
 415         if (!ret)
 416                 v4l2_m2m_try_schedule(m2m_ctx);
 417
 418         return ret;
 419 }
 420 EXPORT_SYMBOL_GPL(v4l2_m2m_streamon);
 421
 422 /**
 423  * v4l2_m2m_streamoff() - turn off streaming for a video queue
 424  */
 425 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 426                        enum v4l2_buf_type type)
 427 {
 428         struct v4l2_m2m_dev *m2m_dev;
 429         struct v4l2_m2m_queue_ctx *q_ctx;
 430         unsigned long flags_job, flags;
 431         int ret;
 432
 433         q_ctx = get_queue_ctx(m2m_ctx, type);
 434         ret = vb2_streamoff(&q_ctx->q, type);
 435         if (ret)
 436                 return ret;
 437
 438         m2m_dev = m2m_ctx->m2m_dev;
 439         spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
 440         /* We should not be scheduled anymore, since we're dropping a queue. */
 441         INIT_LIST_HEAD(&m2m_ctx->queue);
 442         m2m_ctx->job_flags = 0;
 443
 444         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 445         /* Drop queue, since streamoff returns device to the same state as after
 446          * calling reqbufs. */
 447         INIT_LIST_HEAD(&q_ctx->rdy_queue);
 448         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 449
 450         if (m2m_dev->curr_ctx == m2m_ctx) {
 451                 m2m_dev->curr_ctx = NULL;
 452                 wake_up(&m2m_ctx->finished);
 453         }
 454         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 455
 456         return 0;
 457 }
 458 EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff);
 459
 460 /**
 461  * v4l2_m2m_poll() - poll replacement, for destination buffers only
 462  *
 463  * Call from the driver's poll() function. Will poll both queues. If a buffer
 464  * is available to dequeue (with dqbuf) from the source queue, this will
 465  * indicate that a non-blocking write can be performed, while read will be
 466  * returned in case of the destination queue.
 467  */
 468 unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 469                            struct poll_table_struct *wait)
 470 {
 471         struct video_device *vfd = video_devdata(file);
 472         unsigned long req_events = poll_requested_events(wait);
 473         struct vb2_queue *src_q, *dst_q;
 474         struct vb2_buffer *src_vb = NULL, *dst_vb = NULL;
 475         unsigned int rc = 0;
 476         unsigned long flags;
 477
 478         if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
 479                 struct v4l2_fh *fh = file->private_data;
 480
 481                 if (v4l2_event_pending(fh))
 482                         rc = POLLPRI;
 483                 else if (req_events & POLLPRI)
 484                         poll_wait(file, &fh->wait, wait);
 485                 if (!(req_events & (POLLOUT | POLLWRNORM | POLLIN | POLLRDNORM)))
 486                         return rc;
 487         }
 488
 489         src_q = v4l2_m2m_get_src_vq(m2m_ctx);
 490         dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
 491
 492         /*
 493          * There has to be at least one buffer queued on each queued_list, which
 494          * means either in driver already or waiting for driver to claim it
 495          * and start processing.
 496          */
 497         if ((!src_q->streaming || list_empty(&src_q->queued_list))
 498                 && (!dst_q->streaming || list_empty(&dst_q->queued_list))) {
 499                 rc |= POLLERR;
 500                 goto end;
 501         }
 502
 503         if (m2m_ctx->m2m_dev->m2m_ops->unlock)
 504                 m2m_ctx->m2m_dev->m2m_ops->unlock(m2m_ctx->priv);
 505
 506         if (list_empty(&src_q->done_list))
 507                 poll_wait(file, &src_q->done_wq, wait);
 508         if (list_empty(&dst_q->done_list))
 509                 poll_wait(file, &dst_q->done_wq, wait);
 510
 511         if (m2m_ctx->m2m_dev->m2m_ops->lock)
 512                 m2m_ctx->m2m_dev->m2m_ops->lock(m2m_ctx->priv);
 513
 514         spin_lock_irqsave(&src_q->done_lock, flags);
 515         if (!list_empty(&src_q->done_list))
 516                 src_vb = list_first_entry(&src_q->done_list, struct vb2_buffer,
 517                                                 done_entry);
 518         if (src_vb && (src_vb->state == VB2_BUF_STATE_DONE
 519                         || src_vb->state == VB2_BUF_STATE_ERROR))
 520                 rc |= POLLOUT | POLLWRNORM;
 521         spin_unlock_irqrestore(&src_q->done_lock, flags);
 522
 523         spin_lock_irqsave(&dst_q->done_lock, flags);
 524         if (!list_empty(&dst_q->done_list))
 525                 dst_vb = list_first_entry(&dst_q->done_list, struct vb2_buffer,
 526                                                 done_entry);
 527         if (dst_vb && (dst_vb->state == VB2_BUF_STATE_DONE
 528                         || dst_vb->state == VB2_BUF_STATE_ERROR))
 529                 rc |= POLLIN | POLLRDNORM;
 530         spin_unlock_irqrestore(&dst_q->done_lock, flags);
 531
 532 end:
 533         return rc;
 534 }
 535 EXPORT_SYMBOL_GPL(v4l2_m2m_poll);
 536
 537 /**
 538  * v4l2_m2m_mmap() - source and destination queues-aware mmap multiplexer
 539  *
 540  * Call from driver's mmap() function. Will handle mmap() for both queues
 541  * seamlessly for videobuffer, which will receive normal per-queue offsets and
 542  * proper videobuf queue pointers. The differentiation is made outside videobuf
 543  * by adding a predefined offset to buffers from one of the queues and
 544  * subtracting it before passing it back to videobuf. Only drivers (and
 545  * thus applications) receive modified offsets.
 546  */
 547 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 548                          struct vm_area_struct *vma)
 549 {
 550         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 551         struct vb2_queue *vq;
 552
 553         if (offset < DST_QUEUE_OFF_BASE) {
 554                 vq = v4l2_m2m_get_src_vq(m2m_ctx);
 555         } else {
 556                 vq = v4l2_m2m_get_dst_vq(m2m_ctx);
 557                 vma->vm_pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT);
 558         }
 559
 560         return vb2_mmap(vq, vma);
 561 }
 562 EXPORT_SYMBOL(v4l2_m2m_mmap);
 563
 564 /**
 565  * v4l2_m2m_init() - initialize per-driver m2m data
 566  *
 567  * Usually called from driver's probe() function.
 568  */
 569 struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops)
 570 {
 571         struct v4l2_m2m_dev *m2m_dev;
 572
 573         if (!m2m_ops || WARN_ON(!m2m_ops->device_run) ||
 574                         WARN_ON(!m2m_ops->job_abort))
 575                 return ERR_PTR(-EINVAL);
 576
 577         m2m_dev = kzalloc(sizeof *m2m_dev, GFP_KERNEL);
 578         if (!m2m_dev)
 579                 return ERR_PTR(-ENOMEM);
 580
 581         m2m_dev->curr_ctx = NULL;
 582         m2m_dev->m2m_ops = m2m_ops;
 583         INIT_LIST_HEAD(&m2m_dev->job_queue);
 584         spin_lock_init(&m2m_dev->job_spinlock);
 585
 586         return m2m_dev;
 587 }
 588 EXPORT_SYMBOL_GPL(v4l2_m2m_init);
 589
 590 /**
 591  * v4l2_m2m_release() - cleans up and frees a m2m_dev structure
 592  *
 593  * Usually called from driver's remove() function.
 594  */
 595 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev)
 596 {
 597         kfree(m2m_dev);
 598 }
 599 EXPORT_SYMBOL_GPL(v4l2_m2m_release);
 600
 601 /**
 602  * v4l2_m2m_ctx_init() - allocate and initialize a m2m context
 603  * @priv - driver's instance private data
 604  * @m2m_dev - a previously initialized m2m_dev struct
 605  * @vq_init - a callback for queue type-specific initialization function to be
 606  * used for initializing videobuf_queues
 607  *
 608  * Usually called from driver's open() function.
 609  */
 610 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
 611                 void *drv_priv,
 612                 int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq))
 613 {
 614         struct v4l2_m2m_ctx *m2m_ctx;
 615         struct v4l2_m2m_queue_ctx *out_q_ctx, *cap_q_ctx;
 616         int ret;
 617
 618         m2m_ctx = kzalloc(sizeof *m2m_ctx, GFP_KERNEL);
 619         if (!m2m_ctx)
 620                 return ERR_PTR(-ENOMEM);
 621
 622         m2m_ctx->priv = drv_priv;
 623         m2m_ctx->m2m_dev = m2m_dev;
 624         init_waitqueue_head(&m2m_ctx->finished);
 625
 626         out_q_ctx = &m2m_ctx->out_q_ctx;
 627         cap_q_ctx = &m2m_ctx->cap_q_ctx;
 628
 629         INIT_LIST_HEAD(&out_q_ctx->rdy_queue);
 630         INIT_LIST_HEAD(&cap_q_ctx->rdy_queue);
 631         spin_lock_init(&out_q_ctx->rdy_spinlock);
 632         spin_lock_init(&cap_q_ctx->rdy_spinlock);
 633
 634         INIT_LIST_HEAD(&m2m_ctx->queue);
 635
 636         ret = queue_init(drv_priv, &out_q_ctx->q, &cap_q_ctx->q);
 637
 638         if (ret)
 639                 goto err;
 640
 641         return m2m_ctx;
 642 err:
 643         kfree(m2m_ctx);
 644         return ERR_PTR(ret);
 645 }
 646 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_init);
 647
 648 /**
 649  * v4l2_m2m_ctx_release() - release m2m context
 650  *
 651  * Usually called from driver's release() function.
 652  */
 653 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx)
 654 {
 655         struct v4l2_m2m_dev *m2m_dev;
 656         unsigned long flags;
 657
 658         m2m_dev = m2m_ctx->m2m_dev;
 659
 660         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 661         if (m2m_ctx->job_flags & TRANS_RUNNING) {
 662                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 663                 m2m_dev->m2m_ops->job_abort(m2m_ctx->priv);
 664                 dprintk("m2m_ctx %p running, will wait to complete", m2m_ctx);
 665                 wait_event(m2m_ctx->finished, !(m2m_ctx->job_flags & TRANS_RUNNING));
 666         } else if (m2m_ctx->job_flags & TRANS_QUEUED) {
 667                 list_del(&m2m_ctx->queue);
 668                 m2m_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
 669                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 670                 dprintk("m2m_ctx: %p had been on queue and was removed\n",
 671                         m2m_ctx);
 672         } else {
 673                 /* Do nothing, was not on queue/running */
 674                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 675         }
 676
 677         vb2_queue_release(&m2m_ctx->cap_q_ctx.q);
 678         vb2_queue_release(&m2m_ctx->out_q_ctx.q);
 679
 680         kfree(m2m_ctx);
 681 }
 682 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_release);
 683
 684 /**
 685  * v4l2_m2m_buf_queue() - add a buffer to the proper ready buffers list.
 686  *
 687  * Call from buf_queue(), videobuf_queue_ops callback.
 688  */
 689 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct vb2_buffer *vb)
 690 {
 691         struct v4l2_m2m_buffer *b = container_of(vb, struct v4l2_m2m_buffer, vb);
 692         struct v4l2_m2m_queue_ctx *q_ctx;
 693         unsigned long flags;
 694
 695         q_ctx = get_queue_ctx(m2m_ctx, vb->vb2_queue->type);
 696         if (!q_ctx)
 697                 return;
 698
 699         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 700         list_add_tail(&b->list, &q_ctx->rdy_queue);
 701         q_ctx->num_rdy++;
 702         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 703 }
 704 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);
 705