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-v4l2.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 /* Instance is currently aborting */
  45 #define TRANS_ABORT             (1 << 2)
  46
  47
  48 /* Offset base for buffers on the destination queue - used to distinguish
  49  * between source and destination buffers when mmapping - they receive the same
  50  * offsets but for different queues */
  51 #define DST_QUEUE_OFF_BASE      (1 << 30)
  52
  53
  54 /**
  55  * struct v4l2_m2m_dev - per-device context
  56  * @curr_ctx:           currently running instance
  57  * @job_queue:          instances queued to run
  58  * @job_spinlock:       protects job_queue
  59  * @m2m_ops:            driver callbacks
  60  */
  61 struct v4l2_m2m_dev {
  62         struct v4l2_m2m_ctx     *curr_ctx;
  63
  64         struct list_head        job_queue;
  65         spinlock_t              job_spinlock;
  66
  67         const struct v4l2_m2m_ops *m2m_ops;
  68 };
  69
  70 static struct v4l2_m2m_queue_ctx *get_queue_ctx(struct v4l2_m2m_ctx *m2m_ctx,
  71                                                 enum v4l2_buf_type type)
  72 {
  73         if (V4L2_TYPE_IS_OUTPUT(type))
  74                 return &m2m_ctx->out_q_ctx;
  75         else
  76                 return &m2m_ctx->cap_q_ctx;
  77 }
  78
  79 struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
  80                                        enum v4l2_buf_type type)
  81 {
  82         struct v4l2_m2m_queue_ctx *q_ctx;
  83
  84         q_ctx = get_queue_ctx(m2m_ctx, type);
  85         if (!q_ctx)
  86                 return NULL;
  87
  88         return &q_ctx->q;
  89 }
  90 EXPORT_SYMBOL(v4l2_m2m_get_vq);
  91
  92 void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx)
  93 {
  94         struct v4l2_m2m_buffer *b;
  95         unsigned long flags;
  96
  97         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
  98
  99         if (list_empty(&q_ctx->rdy_queue)) {
 100                 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 101                 return NULL;
 102         }
 103
 104         b = list_first_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list);
 105         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 106         return &b->vb;
 107 }
 108 EXPORT_SYMBOL_GPL(v4l2_m2m_next_buf);
 109
 110 void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx)
 111 {
 112         struct v4l2_m2m_buffer *b;
 113         unsigned long flags;
 114
 115         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 116         if (list_empty(&q_ctx->rdy_queue)) {
 117                 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 118                 return NULL;
 119         }
 120         b = list_first_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list);
 121         list_del(&b->list);
 122         q_ctx->num_rdy--;
 123         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 124
 125         return &b->vb;
 126 }
 127 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove);
 128
 129 void v4l2_m2m_buf_remove_by_buf(struct v4l2_m2m_queue_ctx *q_ctx,
 130                                 struct vb2_v4l2_buffer *vbuf)
 131 {
 132         struct v4l2_m2m_buffer *b;
 133         unsigned long flags;
 134
 135         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 136         b = container_of(vbuf, struct v4l2_m2m_buffer, vb);
 137         list_del(&b->list);
 138         q_ctx->num_rdy--;
 139         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 140 }
 141 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove_by_buf);
 142
 143 struct vb2_v4l2_buffer *
 144 v4l2_m2m_buf_remove_by_idx(struct v4l2_m2m_queue_ctx *q_ctx, unsigned int idx)
 145
 146 {
 147         struct v4l2_m2m_buffer *b, *tmp;
 148         struct vb2_v4l2_buffer *ret = NULL;
 149         unsigned long flags;
 150
 151         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 152         list_for_each_entry_safe(b, tmp, &q_ctx->rdy_queue, list) {
 153                 if (b->vb.vb2_buf.index == idx) {
 154                         list_del(&b->list);
 155                         q_ctx->num_rdy--;
 156                         ret = &b->vb;
 157                         break;
 158                 }
 159         }
 160         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 161
 162         return ret;
 163 }
 164 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove_by_idx);
 165
 166 /*
 167  * Scheduling handlers
 168  */
 169
 170 void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev)
 171 {
 172         unsigned long flags;
 173         void *ret = NULL;
 174
 175         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 176         if (m2m_dev->curr_ctx)
 177                 ret = m2m_dev->curr_ctx->priv;
 178         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 179
 180         return ret;
 181 }
 182 EXPORT_SYMBOL(v4l2_m2m_get_curr_priv);
 183
 184 /**
 185  * v4l2_m2m_try_run() - select next job to perform and run it if possible
 186  *
 187  * Get next transaction (if present) from the waiting jobs list and run it.
 188  */
 189 static void v4l2_m2m_try_run(struct v4l2_m2m_dev *m2m_dev)
 190 {
 191         unsigned long flags;
 192
 193         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 194         if (NULL != m2m_dev->curr_ctx) {
 195                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 196                 dprintk("Another instance is running, won't run now\n");
 197                 return;
 198         }
 199
 200         if (list_empty(&m2m_dev->job_queue)) {
 201                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 202                 dprintk("No job pending\n");
 203                 return;
 204         }
 205
 206         m2m_dev->curr_ctx = list_first_entry(&m2m_dev->job_queue,
 207                                    struct v4l2_m2m_ctx, queue);
 208         m2m_dev->curr_ctx->job_flags |= TRANS_RUNNING;
 209         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 210
 211         m2m_dev->m2m_ops->device_run(m2m_dev->curr_ctx->priv);
 212 }
 213
 214 void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx)
 215 {
 216         struct v4l2_m2m_dev *m2m_dev;
 217         unsigned long flags_job, flags_out, flags_cap;
 218
 219         m2m_dev = m2m_ctx->m2m_dev;
 220         dprintk("Trying to schedule a job for m2m_ctx: %p\n", m2m_ctx);
 221
 222         if (!m2m_ctx->out_q_ctx.q.streaming
 223             || !m2m_ctx->cap_q_ctx.q.streaming) {
 224                 dprintk("Streaming needs to be on for both queues\n");
 225                 return;
 226         }
 227
 228         spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
 229
 230         /* If the context is aborted then don't schedule it */
 231         if (m2m_ctx->job_flags & TRANS_ABORT) {
 232                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 233                 dprintk("Aborted context\n");
 234                 return;
 235         }
 236
 237         if (m2m_ctx->job_flags & TRANS_QUEUED) {
 238                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 239                 dprintk("On job queue already\n");
 240                 return;
 241         }
 242
 243         spin_lock_irqsave(&m2m_ctx->out_q_ctx.rdy_spinlock, flags_out);
 244         if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue)
 245             && !m2m_ctx->out_q_ctx.buffered) {
 246                 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock,
 247                                         flags_out);
 248                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 249                 dprintk("No input buffers available\n");
 250                 return;
 251         }
 252         spin_lock_irqsave(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap);
 253         if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)
 254             && !m2m_ctx->cap_q_ctx.buffered) {
 255                 spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock,
 256                                         flags_cap);
 257                 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock,
 258                                         flags_out);
 259                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 260                 dprintk("No output buffers available\n");
 261                 return;
 262         }
 263         spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap);
 264         spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags_out);
 265
 266         if (m2m_dev->m2m_ops->job_ready
 267                 && (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) {
 268                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 269                 dprintk("Driver not ready\n");
 270                 return;
 271         }
 272
 273         list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue);
 274         m2m_ctx->job_flags |= TRANS_QUEUED;
 275
 276         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 277
 278         v4l2_m2m_try_run(m2m_dev);
 279 }
 280 EXPORT_SYMBOL_GPL(v4l2_m2m_try_schedule);
 281
 282 /**
 283  * v4l2_m2m_cancel_job() - cancel pending jobs for the context
 284  *
 285  * In case of streamoff or release called on any context,
 286  * 1] If the context is currently running, then abort job will be called
 287  * 2] If the context is queued, then the context will be removed from
 288  *    the job_queue
 289  */
 290 static void v4l2_m2m_cancel_job(struct v4l2_m2m_ctx *m2m_ctx)
 291 {
 292         struct v4l2_m2m_dev *m2m_dev;
 293         unsigned long flags;
 294
 295         m2m_dev = m2m_ctx->m2m_dev;
 296         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 297
 298         m2m_ctx->job_flags |= TRANS_ABORT;
 299         if (m2m_ctx->job_flags & TRANS_RUNNING) {
 300                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 301                 m2m_dev->m2m_ops->job_abort(m2m_ctx->priv);
 302                 dprintk("m2m_ctx %p running, will wait to complete", m2m_ctx);
 303                 wait_event(m2m_ctx->finished,
 304                                 !(m2m_ctx->job_flags & TRANS_RUNNING));
 305         } else if (m2m_ctx->job_flags & TRANS_QUEUED) {
 306                 list_del(&m2m_ctx->queue);
 307                 m2m_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
 308                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 309                 dprintk("m2m_ctx: %p had been on queue and was removed\n",
 310                         m2m_ctx);
 311         } else {
 312                 /* Do nothing, was not on queue/running */
 313                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 314         }
 315 }
 316
 317 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
 318                          struct v4l2_m2m_ctx *m2m_ctx)
 319 {
 320         unsigned long flags;
 321
 322         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 323         if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) {
 324                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 325                 dprintk("Called by an instance not currently running\n");
 326                 return;
 327         }
 328
 329         list_del(&m2m_dev->curr_ctx->queue);
 330         m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
 331         wake_up(&m2m_dev->curr_ctx->finished);
 332         m2m_dev->curr_ctx = NULL;
 333
 334         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 335
 336         /* This instance might have more buffers ready, but since we do not
 337          * allow more than one job on the job_queue per instance, each has
 338          * to be scheduled separately after the previous one finishes. */
 339         v4l2_m2m_try_schedule(m2m_ctx);
 340         v4l2_m2m_try_run(m2m_dev);
 341 }
 342 EXPORT_SYMBOL(v4l2_m2m_job_finish);
 343
 344 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 345                      struct v4l2_requestbuffers *reqbufs)
 346 {
 347         struct vb2_queue *vq;
 348         int ret;
 349
 350         vq = v4l2_m2m_get_vq(m2m_ctx, reqbufs->type);
 351         ret = vb2_reqbufs(vq, reqbufs);
 352         /* If count == 0, then the owner has released all buffers and he
 353            is no longer owner of the queue. Otherwise we have an owner. */
 354         if (ret == 0)
 355                 vq->owner = reqbufs->count ? file->private_data : NULL;
 356
 357         return ret;
 358 }
 359 EXPORT_SYMBOL_GPL(v4l2_m2m_reqbufs);
 360
 361 static void v4l2_m2m_adjust_mem_offset(struct vb2_queue *vq,
 362                                        struct v4l2_buffer *buf)
 363 {
 364         /* Adjust MMAP memory offsets for the CAPTURE queue */
 365         if (buf->memory == V4L2_MEMORY_MMAP && !V4L2_TYPE_IS_OUTPUT(vq->type)) {
 366                 if (V4L2_TYPE_IS_MULTIPLANAR(vq->type)) {
 367                         unsigned int i;
 368
 369                         for (i = 0; i < buf->length; ++i)
 370                                 buf->m.planes[i].m.mem_offset
 371                                         += DST_QUEUE_OFF_BASE;
 372                 } else {
 373                         buf->m.offset += DST_QUEUE_OFF_BASE;
 374                 }
 375         }
 376 }
 377
 378 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 379                       struct v4l2_buffer *buf)
 380 {
 381         struct vb2_queue *vq;
 382         int ret;
 383
 384         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 385         ret = vb2_querybuf(vq, buf);
 386         if (ret)
 387                 return ret;
 388
 389         /* Adjust MMAP memory offsets for the CAPTURE queue */
 390         v4l2_m2m_adjust_mem_offset(vq, buf);
 391
 392         return 0;
 393 }
 394 EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf);
 395
 396 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 397                   struct v4l2_buffer *buf)
 398 {
 399         struct vb2_queue *vq;
 400         int ret;
 401
 402         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 403         ret = vb2_qbuf(vq, buf);
 404         if (ret)
 405                 return ret;
 406
 407         /* Adjust MMAP memory offsets for the CAPTURE queue */
 408         v4l2_m2m_adjust_mem_offset(vq, buf);
 409
 410         v4l2_m2m_try_schedule(m2m_ctx);
 411
 412         return 0;
 413 }
 414 EXPORT_SYMBOL_GPL(v4l2_m2m_qbuf);
 415
 416 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 417                    struct v4l2_buffer *buf)
 418 {
 419         struct vb2_queue *vq;
 420         int ret;
 421
 422         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 423         ret = vb2_dqbuf(vq, buf, file->f_flags & O_NONBLOCK);
 424         if (ret)
 425                 return ret;
 426
 427         /* Adjust MMAP memory offsets for the CAPTURE queue */
 428         v4l2_m2m_adjust_mem_offset(vq, buf);
 429
 430         return 0;
 431 }
 432 EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
 433
 434 int v4l2_m2m_prepare_buf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 435                          struct v4l2_buffer *buf)
 436 {
 437         struct vb2_queue *vq;
 438         int ret;
 439
 440         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 441         ret = vb2_prepare_buf(vq, buf);
 442         if (ret)
 443                 return ret;
 444
 445         /* Adjust MMAP memory offsets for the CAPTURE queue */
 446         v4l2_m2m_adjust_mem_offset(vq, buf);
 447
 448         v4l2_m2m_try_schedule(m2m_ctx);
 449
 450         return 0;
 451 }
 452 EXPORT_SYMBOL_GPL(v4l2_m2m_prepare_buf);
 453
 454 int v4l2_m2m_create_bufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 455                          struct v4l2_create_buffers *create)
 456 {
 457         struct vb2_queue *vq;
 458
 459         vq = v4l2_m2m_get_vq(m2m_ctx, create->format.type);
 460         return vb2_create_bufs(vq, create);
 461 }
 462 EXPORT_SYMBOL_GPL(v4l2_m2m_create_bufs);
 463
 464 int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 465                   struct v4l2_exportbuffer *eb)
 466 {
 467         struct vb2_queue *vq;
 468
 469         vq = v4l2_m2m_get_vq(m2m_ctx, eb->type);
 470         return vb2_expbuf(vq, eb);
 471 }
 472 EXPORT_SYMBOL_GPL(v4l2_m2m_expbuf);
 473
 474 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 475                       enum v4l2_buf_type type)
 476 {
 477         struct vb2_queue *vq;
 478         int ret;
 479
 480         vq = v4l2_m2m_get_vq(m2m_ctx, type);
 481         ret = vb2_streamon(vq, type);
 482         if (!ret)
 483                 v4l2_m2m_try_schedule(m2m_ctx);
 484
 485         return ret;
 486 }
 487 EXPORT_SYMBOL_GPL(v4l2_m2m_streamon);
 488
 489 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 490                        enum v4l2_buf_type type)
 491 {
 492         struct v4l2_m2m_dev *m2m_dev;
 493         struct v4l2_m2m_queue_ctx *q_ctx;
 494         unsigned long flags_job, flags;
 495         int ret;
 496
 497         /* wait until the current context is dequeued from job_queue */
 498         v4l2_m2m_cancel_job(m2m_ctx);
 499
 500         q_ctx = get_queue_ctx(m2m_ctx, type);
 501         ret = vb2_streamoff(&q_ctx->q, type);
 502         if (ret)
 503                 return ret;
 504
 505         m2m_dev = m2m_ctx->m2m_dev;
 506         spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
 507         /* We should not be scheduled anymore, since we're dropping a queue. */
 508         if (m2m_ctx->job_flags & TRANS_QUEUED)
 509                 list_del(&m2m_ctx->queue);
 510         m2m_ctx->job_flags = 0;
 511
 512         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 513         /* Drop queue, since streamoff returns device to the same state as after
 514          * calling reqbufs. */
 515         INIT_LIST_HEAD(&q_ctx->rdy_queue);
 516         q_ctx->num_rdy = 0;
 517         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 518
 519         if (m2m_dev->curr_ctx == m2m_ctx) {
 520                 m2m_dev->curr_ctx = NULL;
 521                 wake_up(&m2m_ctx->finished);
 522         }
 523         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 524
 525         return 0;
 526 }
 527 EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff);
 528
 529 unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 530                            struct poll_table_struct *wait)
 531 {
 532         struct video_device *vfd = video_devdata(file);
 533         unsigned long req_events = poll_requested_events(wait);
 534         struct vb2_queue *src_q, *dst_q;
 535         struct vb2_buffer *src_vb = NULL, *dst_vb = NULL;
 536         unsigned int rc = 0;
 537         unsigned long flags;
 538
 539         if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
 540                 struct v4l2_fh *fh = file->private_data;
 541
 542                 if (v4l2_event_pending(fh))
 543                         rc = POLLPRI;
 544                 else if (req_events & POLLPRI)
 545                         poll_wait(file, &fh->wait, wait);
 546                 if (!(req_events & (POLLOUT | POLLWRNORM | POLLIN | POLLRDNORM)))
 547                         return rc;
 548         }
 549
 550         src_q = v4l2_m2m_get_src_vq(m2m_ctx);
 551         dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
 552
 553         /*
 554          * There has to be at least one buffer queued on each queued_list, which
 555          * means either in driver already or waiting for driver to claim it
 556          * and start processing.
 557          */
 558         if ((!src_q->streaming || list_empty(&src_q->queued_list))
 559                 && (!dst_q->streaming || list_empty(&dst_q->queued_list))) {
 560                 rc |= POLLERR;
 561                 goto end;
 562         }
 563
 564         spin_lock_irqsave(&src_q->done_lock, flags);
 565         if (list_empty(&src_q->done_list))
 566                 poll_wait(file, &src_q->done_wq, wait);
 567         spin_unlock_irqrestore(&src_q->done_lock, flags);
 568
 569         spin_lock_irqsave(&dst_q->done_lock, flags);
 570         if (list_empty(&dst_q->done_list)) {
 571                 /*
 572                  * If the last buffer was dequeued from the capture queue,
 573                  * return immediately. DQBUF will return -EPIPE.
 574                  */
 575                 if (dst_q->last_buffer_dequeued) {
 576                         spin_unlock_irqrestore(&dst_q->done_lock, flags);
 577                         return rc | POLLIN | POLLRDNORM;
 578                 }
 579
 580                 poll_wait(file, &dst_q->done_wq, wait);
 581         }
 582         spin_unlock_irqrestore(&dst_q->done_lock, flags);
 583
 584         spin_lock_irqsave(&src_q->done_lock, flags);
 585         if (!list_empty(&src_q->done_list))
 586                 src_vb = list_first_entry(&src_q->done_list, struct vb2_buffer,
 587                                                 done_entry);
 588         if (src_vb && (src_vb->state == VB2_BUF_STATE_DONE
 589                         || src_vb->state == VB2_BUF_STATE_ERROR))
 590                 rc |= POLLOUT | POLLWRNORM;
 591         spin_unlock_irqrestore(&src_q->done_lock, flags);
 592
 593         spin_lock_irqsave(&dst_q->done_lock, flags);
 594         if (!list_empty(&dst_q->done_list))
 595                 dst_vb = list_first_entry(&dst_q->done_list, struct vb2_buffer,
 596                                                 done_entry);
 597         if (dst_vb && (dst_vb->state == VB2_BUF_STATE_DONE
 598                         || dst_vb->state == VB2_BUF_STATE_ERROR))
 599                 rc |= POLLIN | POLLRDNORM;
 600         spin_unlock_irqrestore(&dst_q->done_lock, flags);
 601
 602 end:
 603         return rc;
 604 }
 605 EXPORT_SYMBOL_GPL(v4l2_m2m_poll);
 606
 607 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 608                          struct vm_area_struct *vma)
 609 {
 610         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 611         struct vb2_queue *vq;
 612
 613         if (offset < DST_QUEUE_OFF_BASE) {
 614                 vq = v4l2_m2m_get_src_vq(m2m_ctx);
 615         } else {
 616                 vq = v4l2_m2m_get_dst_vq(m2m_ctx);
 617                 vma->vm_pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT);
 618         }
 619
 620         return vb2_mmap(vq, vma);
 621 }
 622 EXPORT_SYMBOL(v4l2_m2m_mmap);
 623
 624 struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops)
 625 {
 626         struct v4l2_m2m_dev *m2m_dev;
 627
 628         if (!m2m_ops || WARN_ON(!m2m_ops->device_run) ||
 629                         WARN_ON(!m2m_ops->job_abort))
 630                 return ERR_PTR(-EINVAL);
 631
 632         m2m_dev = kzalloc(sizeof *m2m_dev, GFP_KERNEL);
 633         if (!m2m_dev)
 634                 return ERR_PTR(-ENOMEM);
 635
 636         m2m_dev->curr_ctx = NULL;
 637         m2m_dev->m2m_ops = m2m_ops;
 638         INIT_LIST_HEAD(&m2m_dev->job_queue);
 639         spin_lock_init(&m2m_dev->job_spinlock);
 640
 641         return m2m_dev;
 642 }
 643 EXPORT_SYMBOL_GPL(v4l2_m2m_init);
 644
 645 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev)
 646 {
 647         kfree(m2m_dev);
 648 }
 649 EXPORT_SYMBOL_GPL(v4l2_m2m_release);
 650
 651 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
 652                 void *drv_priv,
 653                 int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq))
 654 {
 655         struct v4l2_m2m_ctx *m2m_ctx;
 656         struct v4l2_m2m_queue_ctx *out_q_ctx, *cap_q_ctx;
 657         int ret;
 658
 659         m2m_ctx = kzalloc(sizeof *m2m_ctx, GFP_KERNEL);
 660         if (!m2m_ctx)
 661                 return ERR_PTR(-ENOMEM);
 662
 663         m2m_ctx->priv = drv_priv;
 664         m2m_ctx->m2m_dev = m2m_dev;
 665         init_waitqueue_head(&m2m_ctx->finished);
 666
 667         out_q_ctx = &m2m_ctx->out_q_ctx;
 668         cap_q_ctx = &m2m_ctx->cap_q_ctx;
 669
 670         INIT_LIST_HEAD(&out_q_ctx->rdy_queue);
 671         INIT_LIST_HEAD(&cap_q_ctx->rdy_queue);
 672         spin_lock_init(&out_q_ctx->rdy_spinlock);
 673         spin_lock_init(&cap_q_ctx->rdy_spinlock);
 674
 675         INIT_LIST_HEAD(&m2m_ctx->queue);
 676
 677         ret = queue_init(drv_priv, &out_q_ctx->q, &cap_q_ctx->q);
 678
 679         if (ret)
 680                 goto err;
 681         /*
 682          * If both queues use same mutex assign it as the common buffer
 683          * queues lock to the m2m context. This lock is used in the
 684          * v4l2_m2m_ioctl_* helpers.
 685          */
 686         if (out_q_ctx->q.lock == cap_q_ctx->q.lock)
 687                 m2m_ctx->q_lock = out_q_ctx->q.lock;
 688
 689         return m2m_ctx;
 690 err:
 691         kfree(m2m_ctx);
 692         return ERR_PTR(ret);
 693 }
 694 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_init);
 695
 696 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx)
 697 {
 698         /* wait until the current context is dequeued from job_queue */
 699         v4l2_m2m_cancel_job(m2m_ctx);
 700
 701         vb2_queue_release(&m2m_ctx->cap_q_ctx.q);
 702         vb2_queue_release(&m2m_ctx->out_q_ctx.q);
 703
 704         kfree(m2m_ctx);
 705 }
 706 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_release);
 707
 708 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx,
 709                 struct vb2_v4l2_buffer *vbuf)
 710 {
 711         struct v4l2_m2m_buffer *b = container_of(vbuf,
 712                                 struct v4l2_m2m_buffer, vb);
 713         struct v4l2_m2m_queue_ctx *q_ctx;
 714         unsigned long flags;
 715
 716         q_ctx = get_queue_ctx(m2m_ctx, vbuf->vb2_buf.vb2_queue->type);
 717         if (!q_ctx)
 718                 return;
 719
 720         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 721         list_add_tail(&b->list, &q_ctx->rdy_queue);
 722         q_ctx->num_rdy++;
 723         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 724 }
 725 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);
 726
 727 /* Videobuf2 ioctl helpers */
 728
 729 int v4l2_m2m_ioctl_reqbufs(struct file *file, void *priv,
 730                                 struct v4l2_requestbuffers *rb)
 731 {
 732         struct v4l2_fh *fh = file->private_data;
 733
 734         return v4l2_m2m_reqbufs(file, fh->m2m_ctx, rb);
 735 }
 736 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_reqbufs);
 737
 738 int v4l2_m2m_ioctl_create_bufs(struct file *file, void *priv,
 739                                 struct v4l2_create_buffers *create)
 740 {
 741         struct v4l2_fh *fh = file->private_data;
 742
 743         return v4l2_m2m_create_bufs(file, fh->m2m_ctx, create);
 744 }
 745 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_create_bufs);
 746
 747 int v4l2_m2m_ioctl_querybuf(struct file *file, void *priv,
 748                                 struct v4l2_buffer *buf)
 749 {
 750         struct v4l2_fh *fh = file->private_data;
 751
 752         return v4l2_m2m_querybuf(file, fh->m2m_ctx, buf);
 753 }
 754 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_querybuf);
 755
 756 int v4l2_m2m_ioctl_qbuf(struct file *file, void *priv,
 757                                 struct v4l2_buffer *buf)
 758 {
 759         struct v4l2_fh *fh = file->private_data;
 760
 761         return v4l2_m2m_qbuf(file, fh->m2m_ctx, buf);
 762 }
 763 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_qbuf);
 764
 765 int v4l2_m2m_ioctl_dqbuf(struct file *file, void *priv,
 766                                 struct v4l2_buffer *buf)
 767 {
 768         struct v4l2_fh *fh = file->private_data;
 769
 770         return v4l2_m2m_dqbuf(file, fh->m2m_ctx, buf);
 771 }
 772 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_dqbuf);
 773
 774 int v4l2_m2m_ioctl_prepare_buf(struct file *file, void *priv,
 775                                struct v4l2_buffer *buf)
 776 {
 777         struct v4l2_fh *fh = file->private_data;
 778
 779         return v4l2_m2m_prepare_buf(file, fh->m2m_ctx, buf);
 780 }
 781 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_prepare_buf);
 782
 783 int v4l2_m2m_ioctl_expbuf(struct file *file, void *priv,
 784                                 struct v4l2_exportbuffer *eb)
 785 {
 786         struct v4l2_fh *fh = file->private_data;
 787
 788         return v4l2_m2m_expbuf(file, fh->m2m_ctx, eb);
 789 }
 790 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_expbuf);
 791
 792 int v4l2_m2m_ioctl_streamon(struct file *file, void *priv,
 793                                 enum v4l2_buf_type type)
 794 {
 795         struct v4l2_fh *fh = file->private_data;
 796
 797         return v4l2_m2m_streamon(file, fh->m2m_ctx, type);
 798 }
 799 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_streamon);
 800
 801 int v4l2_m2m_ioctl_streamoff(struct file *file, void *priv,
 802                                 enum v4l2_buf_type type)
 803 {
 804         struct v4l2_fh *fh = file->private_data;
 805
 806         return v4l2_m2m_streamoff(file, fh->m2m_ctx, type);
 807 }
 808 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_streamoff);
 809
 810 /*
 811  * v4l2_file_operations helpers. It is assumed here same lock is used
 812  * for the output and the capture buffer queue.
 813  */
 814
 815 int v4l2_m2m_fop_mmap(struct file *file, struct vm_area_struct *vma)
 816 {
 817         struct v4l2_fh *fh = file->private_data;
 818
 819         return v4l2_m2m_mmap(file, fh->m2m_ctx, vma);
 820 }
 821 EXPORT_SYMBOL_GPL(v4l2_m2m_fop_mmap);
 822
 823 unsigned int v4l2_m2m_fop_poll(struct file *file, poll_table *wait)
 824 {
 825         struct v4l2_fh *fh = file->private_data;
 826         struct v4l2_m2m_ctx *m2m_ctx = fh->m2m_ctx;
 827         unsigned int ret;
 828
 829         if (m2m_ctx->q_lock)
 830                 mutex_lock(m2m_ctx->q_lock);
 831
 832         ret = v4l2_m2m_poll(file, m2m_ctx, wait);
 833
 834         if (m2m_ctx->q_lock)
 835                 mutex_unlock(m2m_ctx->q_lock);
 836
 837         return ret;
 838 }
 839 EXPORT_SYMBOL_GPL(v4l2_m2m_fop_poll);
 840