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 /** 80 * v4l2_m2m_get_vq() - return vb2_queue for the given type 81 */ 82 struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx, 83 enum v4l2_buf_type type) 84 { 85 struct v4l2_m2m_queue_ctx *q_ctx; 86 87 q_ctx = get_queue_ctx(m2m_ctx, type); 88 if (!q_ctx) 89 return NULL; 90 91 return &q_ctx->q; 92 } 93 EXPORT_SYMBOL(v4l2_m2m_get_vq); 94 95 /** 96 * v4l2_m2m_next_buf() - return next buffer from the list of ready buffers 97 */ 98 void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx) 99 { 100 struct v4l2_m2m_buffer *b; 101 unsigned long flags; 102 103 spin_lock_irqsave(&q_ctx->rdy_spinlock, flags); 104 105 if (list_empty(&q_ctx->rdy_queue)) { 106 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags); 107 return NULL; 108 } 109 110 b = list_first_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list); 111 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags); 112 return &b->vb; 113 } 114 EXPORT_SYMBOL_GPL(v4l2_m2m_next_buf); 115 116 /** 117 * v4l2_m2m_buf_remove() - take off a buffer from the list of ready buffers and 118 * return it 119 */ 120 void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx) 121 { 122 struct v4l2_m2m_buffer *b; 123 unsigned long flags; 124 125 spin_lock_irqsave(&q_ctx->rdy_spinlock, flags); 126 if (list_empty(&q_ctx->rdy_queue)) { 127 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags); 128 return NULL; 129 } 130 b = list_first_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list); 131 list_del(&b->list); 132 q_ctx->num_rdy--; 133 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags); 134 135 return &b->vb; 136 } 137 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove); 138 139 /* 140 * Scheduling handlers 141 */ 142 143 /** 144 * v4l2_m2m_get_curr_priv() - return driver private data for the currently 145 * running instance or NULL if no instance is running 146 */ 147 void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev) 148 { 149 unsigned long flags; 150 void *ret = NULL; 151 152 spin_lock_irqsave(&m2m_dev->job_spinlock, flags); 153 if (m2m_dev->curr_ctx) 154 ret = m2m_dev->curr_ctx->priv; 155 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); 156 157 return ret; 158 } 159 EXPORT_SYMBOL(v4l2_m2m_get_curr_priv); 160 161 /** 162 * v4l2_m2m_try_run() - select next job to perform and run it if possible 163 * 164 * Get next transaction (if present) from the waiting jobs list and run it. 165 */ 166 static void v4l2_m2m_try_run(struct v4l2_m2m_dev *m2m_dev) 167 { 168 unsigned long flags; 169 170 spin_lock_irqsave(&m2m_dev->job_spinlock, flags); 171 if (NULL != m2m_dev->curr_ctx) { 172 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); 173 dprintk("Another instance is running, won't run now\n"); 174 return; 175 } 176 177 if (list_empty(&m2m_dev->job_queue)) { 178 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); 179 dprintk("No job pending\n"); 180 return; 181 } 182 183 m2m_dev->curr_ctx = list_first_entry(&m2m_dev->job_queue, 184 struct v4l2_m2m_ctx, queue); 185 m2m_dev->curr_ctx->job_flags |= TRANS_RUNNING; 186 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); 187 188 m2m_dev->m2m_ops->device_run(m2m_dev->curr_ctx->priv); 189 } 190 191 /** 192 * v4l2_m2m_try_schedule() - check whether an instance is ready to be added to 193 * the pending job queue and add it if so. 194 * @m2m_ctx: m2m context assigned to the instance to be checked 195 * 196 * There are three basic requirements an instance has to meet to be able to run: 197 * 1) at least one source buffer has to be queued, 198 * 2) at least one destination buffer has to be queued, 199 * 3) streaming has to be on. 200 * 201 * If a queue is buffered (for example a decoder hardware ringbuffer that has 202 * to be drained before doing streamoff), allow scheduling without v4l2 buffers 203 * on that queue. 204 * 205 * There may also be additional, custom requirements. In such case the driver 206 * should supply a custom callback (job_ready in v4l2_m2m_ops) that should 207 * return 1 if the instance is ready. 208 * An example of the above could be an instance that requires more than one 209 * src/dst buffer per transaction. 210 */ 211 void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx) 212 { 213 struct v4l2_m2m_dev *m2m_dev; 214 unsigned long flags_job, flags_out, flags_cap; 215 216 m2m_dev = m2m_ctx->m2m_dev; 217 dprintk("Trying to schedule a job for m2m_ctx: %p\n", m2m_ctx); 218 219 if (!m2m_ctx->out_q_ctx.q.streaming 220 || !m2m_ctx->cap_q_ctx.q.streaming) { 221 dprintk("Streaming needs to be on for both queues\n"); 222 return; 223 } 224 225 spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job); 226 227 /* If the context is aborted then don't schedule it */ 228 if (m2m_ctx->job_flags & TRANS_ABORT) { 229 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job); 230 dprintk("Aborted context\n"); 231 return; 232 } 233 234 if (m2m_ctx->job_flags & TRANS_QUEUED) { 235 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job); 236 dprintk("On job queue already\n"); 237 return; 238 } 239 240 spin_lock_irqsave(&m2m_ctx->out_q_ctx.rdy_spinlock, flags_out); 241 if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue) 242 && !m2m_ctx->out_q_ctx.buffered) { 243 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, 244 flags_out); 245 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job); 246 dprintk("No input buffers available\n"); 247 return; 248 } 249 spin_lock_irqsave(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap); 250 if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue) 251 && !m2m_ctx->cap_q_ctx.buffered) { 252 spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, 253 flags_cap); 254 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, 255 flags_out); 256 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job); 257 dprintk("No output buffers available\n"); 258 return; 259 } 260 spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap); 261 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags_out); 262 263 if (m2m_dev->m2m_ops->job_ready 264 && (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) { 265 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job); 266 dprintk("Driver not ready\n"); 267 return; 268 } 269 270 list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue); 271 m2m_ctx->job_flags |= TRANS_QUEUED; 272 273 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job); 274 275 v4l2_m2m_try_run(m2m_dev); 276 } 277 EXPORT_SYMBOL_GPL(v4l2_m2m_try_schedule); 278 279 /** 280 * v4l2_m2m_cancel_job() - cancel pending jobs for the context 281 * 282 * In case of streamoff or release called on any context, 283 * 1] If the context is currently running, then abort job will be called 284 * 2] If the context is queued, then the context will be removed from 285 * the job_queue 286 */ 287 static void v4l2_m2m_cancel_job(struct v4l2_m2m_ctx *m2m_ctx) 288 { 289 struct v4l2_m2m_dev *m2m_dev; 290 unsigned long flags; 291 292 m2m_dev = m2m_ctx->m2m_dev; 293 spin_lock_irqsave(&m2m_dev->job_spinlock, flags); 294 295 m2m_ctx->job_flags |= TRANS_ABORT; 296 if (m2m_ctx->job_flags & TRANS_RUNNING) { 297 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); 298 m2m_dev->m2m_ops->job_abort(m2m_ctx->priv); 299 dprintk("m2m_ctx %p running, will wait to complete", m2m_ctx); 300 wait_event(m2m_ctx->finished, 301 !(m2m_ctx->job_flags & TRANS_RUNNING)); 302 } else if (m2m_ctx->job_flags & TRANS_QUEUED) { 303 list_del(&m2m_ctx->queue); 304 m2m_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING); 305 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); 306 dprintk("m2m_ctx: %p had been on queue and was removed\n", 307 m2m_ctx); 308 } else { 309 /* Do nothing, was not on queue/running */ 310 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); 311 } 312 } 313 314 /** 315 * v4l2_m2m_job_finish() - inform the framework that a job has been finished 316 * and have it clean up 317 * 318 * Called by a driver to yield back the device after it has finished with it. 319 * Should be called as soon as possible after reaching a state which allows 320 * other instances to take control of the device. 321 * 322 * This function has to be called only after device_run() callback has been 323 * called on the driver. To prevent recursion, it should not be called directly 324 * from the device_run() callback though. 325 */ 326 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev, 327 struct v4l2_m2m_ctx *m2m_ctx) 328 { 329 unsigned long flags; 330 331 spin_lock_irqsave(&m2m_dev->job_spinlock, flags); 332 if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) { 333 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); 334 dprintk("Called by an instance not currently running\n"); 335 return; 336 } 337 338 list_del(&m2m_dev->curr_ctx->queue); 339 m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING); 340 wake_up(&m2m_dev->curr_ctx->finished); 341 m2m_dev->curr_ctx = NULL; 342 343 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); 344 345 /* This instance might have more buffers ready, but since we do not 346 * allow more than one job on the job_queue per instance, each has 347 * to be scheduled separately after the previous one finishes. */ 348 v4l2_m2m_try_schedule(m2m_ctx); 349 v4l2_m2m_try_run(m2m_dev); 350 } 351 EXPORT_SYMBOL(v4l2_m2m_job_finish); 352 353 /** 354 * v4l2_m2m_reqbufs() - multi-queue-aware REQBUFS multiplexer 355 */ 356 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, 357 struct v4l2_requestbuffers *reqbufs) 358 { 359 struct vb2_queue *vq; 360 int ret; 361 362 vq = v4l2_m2m_get_vq(m2m_ctx, reqbufs->type); 363 ret = vb2_reqbufs(vq, reqbufs); 364 /* If count == 0, then the owner has released all buffers and he 365 is no longer owner of the queue. Otherwise we have an owner. */ 366 if (ret == 0) 367 vq->owner = reqbufs->count ? file->private_data : NULL; 368 369 return ret; 370 } 371 EXPORT_SYMBOL_GPL(v4l2_m2m_reqbufs); 372 373 /** 374 * v4l2_m2m_querybuf() - multi-queue-aware QUERYBUF multiplexer 375 * 376 * See v4l2_m2m_mmap() documentation for details. 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 = 0; 383 unsigned int i; 384 385 vq = v4l2_m2m_get_vq(m2m_ctx, buf->type); 386 ret = vb2_querybuf(vq, buf); 387 388 /* Adjust MMAP memory offsets for the CAPTURE queue */ 389 if (buf->memory == V4L2_MEMORY_MMAP && !V4L2_TYPE_IS_OUTPUT(vq->type)) { 390 if (V4L2_TYPE_IS_MULTIPLANAR(vq->type)) { 391 for (i = 0; i < buf->length; ++i) 392 buf->m.planes[i].m.mem_offset 393 += DST_QUEUE_OFF_BASE; 394 } else { 395 buf->m.offset += DST_QUEUE_OFF_BASE; 396 } 397 } 398 399 return ret; 400 } 401 EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf); 402 403 /** 404 * v4l2_m2m_qbuf() - enqueue a source or destination buffer, depending on 405 * the type 406 */ 407 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, 408 struct v4l2_buffer *buf) 409 { 410 struct vb2_queue *vq; 411 int ret; 412 413 vq = v4l2_m2m_get_vq(m2m_ctx, buf->type); 414 ret = vb2_qbuf(vq, buf); 415 if (!ret) 416 v4l2_m2m_try_schedule(m2m_ctx); 417 418 return ret; 419 } 420 EXPORT_SYMBOL_GPL(v4l2_m2m_qbuf); 421 422 /** 423 * v4l2_m2m_dqbuf() - dequeue a source or destination buffer, depending on 424 * the type 425 */ 426 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, 427 struct v4l2_buffer *buf) 428 { 429 struct vb2_queue *vq; 430 431 vq = v4l2_m2m_get_vq(m2m_ctx, buf->type); 432 return vb2_dqbuf(vq, buf, file->f_flags & O_NONBLOCK); 433 } 434 EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf); 435 436 /** 437 * v4l2_m2m_prepare_buf() - prepare a source or destination buffer, depending on 438 * the type 439 */ 440 int v4l2_m2m_prepare_buf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, 441 struct v4l2_buffer *buf) 442 { 443 struct vb2_queue *vq; 444 int ret; 445 446 vq = v4l2_m2m_get_vq(m2m_ctx, buf->type); 447 ret = vb2_prepare_buf(vq, buf); 448 if (!ret) 449 v4l2_m2m_try_schedule(m2m_ctx); 450 451 return ret; 452 } 453 EXPORT_SYMBOL_GPL(v4l2_m2m_prepare_buf); 454 455 /** 456 * v4l2_m2m_create_bufs() - create a source or destination buffer, depending 457 * on the type 458 */ 459 int v4l2_m2m_create_bufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, 460 struct v4l2_create_buffers *create) 461 { 462 struct vb2_queue *vq; 463 464 vq = v4l2_m2m_get_vq(m2m_ctx, create->format.type); 465 return vb2_create_bufs(vq, create); 466 } 467 EXPORT_SYMBOL_GPL(v4l2_m2m_create_bufs); 468 469 /** 470 * v4l2_m2m_expbuf() - export a source or destination buffer, depending on 471 * the type 472 */ 473 int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, 474 struct v4l2_exportbuffer *eb) 475 { 476 struct vb2_queue *vq; 477 478 vq = v4l2_m2m_get_vq(m2m_ctx, eb->type); 479 return vb2_expbuf(vq, eb); 480 } 481 EXPORT_SYMBOL_GPL(v4l2_m2m_expbuf); 482 /** 483 * v4l2_m2m_streamon() - turn on streaming for a video queue 484 */ 485 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, 486 enum v4l2_buf_type type) 487 { 488 struct vb2_queue *vq; 489 int ret; 490 491 vq = v4l2_m2m_get_vq(m2m_ctx, type); 492 ret = vb2_streamon(vq, type); 493 if (!ret) 494 v4l2_m2m_try_schedule(m2m_ctx); 495 496 return ret; 497 } 498 EXPORT_SYMBOL_GPL(v4l2_m2m_streamon); 499 500 /** 501 * v4l2_m2m_streamoff() - turn off streaming for a video queue 502 */ 503 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, 504 enum v4l2_buf_type type) 505 { 506 struct v4l2_m2m_dev *m2m_dev; 507 struct v4l2_m2m_queue_ctx *q_ctx; 508 unsigned long flags_job, flags; 509 int ret; 510 511 /* wait until the current context is dequeued from job_queue */ 512 v4l2_m2m_cancel_job(m2m_ctx); 513 514 q_ctx = get_queue_ctx(m2m_ctx, type); 515 ret = vb2_streamoff(&q_ctx->q, type); 516 if (ret) 517 return ret; 518 519 m2m_dev = m2m_ctx->m2m_dev; 520 spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job); 521 /* We should not be scheduled anymore, since we're dropping a queue. */ 522 if (m2m_ctx->job_flags & TRANS_QUEUED) 523 list_del(&m2m_ctx->queue); 524 m2m_ctx->job_flags = 0; 525 526 spin_lock_irqsave(&q_ctx->rdy_spinlock, flags); 527 /* Drop queue, since streamoff returns device to the same state as after 528 * calling reqbufs. */ 529 INIT_LIST_HEAD(&q_ctx->rdy_queue); 530 q_ctx->num_rdy = 0; 531 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags); 532 533 if (m2m_dev->curr_ctx == m2m_ctx) { 534 m2m_dev->curr_ctx = NULL; 535 wake_up(&m2m_ctx->finished); 536 } 537 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job); 538 539 return 0; 540 } 541 EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff); 542 543 /** 544 * v4l2_m2m_poll() - poll replacement, for destination buffers only 545 * 546 * Call from the driver's poll() function. Will poll both queues. If a buffer 547 * is available to dequeue (with dqbuf) from the source queue, this will 548 * indicate that a non-blocking write can be performed, while read will be 549 * returned in case of the destination queue. 550 */ 551 unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, 552 struct poll_table_struct *wait) 553 { 554 struct video_device *vfd = video_devdata(file); 555 unsigned long req_events = poll_requested_events(wait); 556 struct vb2_queue *src_q, *dst_q; 557 struct vb2_buffer *src_vb = NULL, *dst_vb = NULL; 558 unsigned int rc = 0; 559 unsigned long flags; 560 561 if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) { 562 struct v4l2_fh *fh = file->private_data; 563 564 if (v4l2_event_pending(fh)) 565 rc = POLLPRI; 566 else if (req_events & POLLPRI) 567 poll_wait(file, &fh->wait, wait); 568 if (!(req_events & (POLLOUT | POLLWRNORM | POLLIN | POLLRDNORM))) 569 return rc; 570 } 571 572 src_q = v4l2_m2m_get_src_vq(m2m_ctx); 573 dst_q = v4l2_m2m_get_dst_vq(m2m_ctx); 574 575 /* 576 * There has to be at least one buffer queued on each queued_list, which 577 * means either in driver already or waiting for driver to claim it 578 * and start processing. 579 */ 580 if ((!src_q->streaming || list_empty(&src_q->queued_list)) 581 && (!dst_q->streaming || list_empty(&dst_q->queued_list))) { 582 rc |= POLLERR; 583 goto end; 584 } 585 586 spin_lock_irqsave(&src_q->done_lock, flags); 587 if (list_empty(&src_q->done_list)) 588 poll_wait(file, &src_q->done_wq, wait); 589 spin_unlock_irqrestore(&src_q->done_lock, flags); 590 591 spin_lock_irqsave(&dst_q->done_lock, flags); 592 if (list_empty(&dst_q->done_list)) { 593 /* 594 * If the last buffer was dequeued from the capture queue, 595 * return immediately. DQBUF will return -EPIPE. 596 */ 597 if (dst_q->last_buffer_dequeued) { 598 spin_unlock_irqrestore(&dst_q->done_lock, flags); 599 return rc | POLLIN | POLLRDNORM; 600 } 601 602 poll_wait(file, &dst_q->done_wq, wait); 603 } 604 spin_unlock_irqrestore(&dst_q->done_lock, flags); 605 606 spin_lock_irqsave(&src_q->done_lock, flags); 607 if (!list_empty(&src_q->done_list)) 608 src_vb = list_first_entry(&src_q->done_list, struct vb2_buffer, 609 done_entry); 610 if (src_vb && (src_vb->state == VB2_BUF_STATE_DONE 611 || src_vb->state == VB2_BUF_STATE_ERROR)) 612 rc |= POLLOUT | POLLWRNORM; 613 spin_unlock_irqrestore(&src_q->done_lock, flags); 614 615 spin_lock_irqsave(&dst_q->done_lock, flags); 616 if (!list_empty(&dst_q->done_list)) 617 dst_vb = list_first_entry(&dst_q->done_list, struct vb2_buffer, 618 done_entry); 619 if (dst_vb && (dst_vb->state == VB2_BUF_STATE_DONE 620 || dst_vb->state == VB2_BUF_STATE_ERROR)) 621 rc |= POLLIN | POLLRDNORM; 622 spin_unlock_irqrestore(&dst_q->done_lock, flags); 623 624 end: 625 return rc; 626 } 627 EXPORT_SYMBOL_GPL(v4l2_m2m_poll); 628 629 /** 630 * v4l2_m2m_mmap() - source and destination queues-aware mmap multiplexer 631 * 632 * Call from driver's mmap() function. Will handle mmap() for both queues 633 * seamlessly for videobuffer, which will receive normal per-queue offsets and 634 * proper videobuf queue pointers. The differentiation is made outside videobuf 635 * by adding a predefined offset to buffers from one of the queues and 636 * subtracting it before passing it back to videobuf. Only drivers (and 637 * thus applications) receive modified offsets. 638 */ 639 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, 640 struct vm_area_struct *vma) 641 { 642 unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; 643 struct vb2_queue *vq; 644 645 if (offset < DST_QUEUE_OFF_BASE) { 646 vq = v4l2_m2m_get_src_vq(m2m_ctx); 647 } else { 648 vq = v4l2_m2m_get_dst_vq(m2m_ctx); 649 vma->vm_pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT); 650 } 651 652 return vb2_mmap(vq, vma); 653 } 654 EXPORT_SYMBOL(v4l2_m2m_mmap); 655 656 /** 657 * v4l2_m2m_init() - initialize per-driver m2m data 658 * 659 * Usually called from driver's probe() function. 660 */ 661 struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops) 662 { 663 struct v4l2_m2m_dev *m2m_dev; 664 665 if (!m2m_ops || WARN_ON(!m2m_ops->device_run) || 666 WARN_ON(!m2m_ops->job_abort)) 667 return ERR_PTR(-EINVAL); 668 669 m2m_dev = kzalloc(sizeof *m2m_dev, GFP_KERNEL); 670 if (!m2m_dev) 671 return ERR_PTR(-ENOMEM); 672 673 m2m_dev->curr_ctx = NULL; 674 m2m_dev->m2m_ops = m2m_ops; 675 INIT_LIST_HEAD(&m2m_dev->job_queue); 676 spin_lock_init(&m2m_dev->job_spinlock); 677 678 return m2m_dev; 679 } 680 EXPORT_SYMBOL_GPL(v4l2_m2m_init); 681 682 /** 683 * v4l2_m2m_release() - cleans up and frees a m2m_dev structure 684 * 685 * Usually called from driver's remove() function. 686 */ 687 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev) 688 { 689 kfree(m2m_dev); 690 } 691 EXPORT_SYMBOL_GPL(v4l2_m2m_release); 692 693 /** 694 * v4l2_m2m_ctx_init() - allocate and initialize a m2m context 695 * @priv - driver's instance private data 696 * @m2m_dev - a previously initialized m2m_dev struct 697 * @vq_init - a callback for queue type-specific initialization function to be 698 * used for initializing videobuf_queues 699 * 700 * Usually called from driver's open() function. 701 */ 702 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev, 703 void *drv_priv, 704 int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq)) 705 { 706 struct v4l2_m2m_ctx *m2m_ctx; 707 struct v4l2_m2m_queue_ctx *out_q_ctx, *cap_q_ctx; 708 int ret; 709 710 m2m_ctx = kzalloc(sizeof *m2m_ctx, GFP_KERNEL); 711 if (!m2m_ctx) 712 return ERR_PTR(-ENOMEM); 713 714 m2m_ctx->priv = drv_priv; 715 m2m_ctx->m2m_dev = m2m_dev; 716 init_waitqueue_head(&m2m_ctx->finished); 717 718 out_q_ctx = &m2m_ctx->out_q_ctx; 719 cap_q_ctx = &m2m_ctx->cap_q_ctx; 720 721 INIT_LIST_HEAD(&out_q_ctx->rdy_queue); 722 INIT_LIST_HEAD(&cap_q_ctx->rdy_queue); 723 spin_lock_init(&out_q_ctx->rdy_spinlock); 724 spin_lock_init(&cap_q_ctx->rdy_spinlock); 725 726 INIT_LIST_HEAD(&m2m_ctx->queue); 727 728 ret = queue_init(drv_priv, &out_q_ctx->q, &cap_q_ctx->q); 729 730 if (ret) 731 goto err; 732 /* 733 * If both queues use same mutex assign it as the common buffer 734 * queues lock to the m2m context. This lock is used in the 735 * v4l2_m2m_ioctl_* helpers. 736 */ 737 if (out_q_ctx->q.lock == cap_q_ctx->q.lock) 738 m2m_ctx->q_lock = out_q_ctx->q.lock; 739 740 return m2m_ctx; 741 err: 742 kfree(m2m_ctx); 743 return ERR_PTR(ret); 744 } 745 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_init); 746 747 /** 748 * v4l2_m2m_ctx_release() - release m2m context 749 * 750 * Usually called from driver's release() function. 751 */ 752 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx) 753 { 754 /* wait until the current context is dequeued from job_queue */ 755 v4l2_m2m_cancel_job(m2m_ctx); 756 757 vb2_queue_release(&m2m_ctx->cap_q_ctx.q); 758 vb2_queue_release(&m2m_ctx->out_q_ctx.q); 759 760 kfree(m2m_ctx); 761 } 762 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_release); 763 764 /** 765 * v4l2_m2m_buf_queue() - add a buffer to the proper ready buffers list. 766 * 767 * Call from buf_queue(), videobuf_queue_ops callback. 768 */ 769 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, 770 struct vb2_v4l2_buffer *vbuf) 771 { 772 struct v4l2_m2m_buffer *b = container_of(vbuf, 773 struct v4l2_m2m_buffer, vb); 774 struct v4l2_m2m_queue_ctx *q_ctx; 775 unsigned long flags; 776 777 q_ctx = get_queue_ctx(m2m_ctx, vbuf->vb2_buf.vb2_queue->type); 778 if (!q_ctx) 779 return; 780 781 spin_lock_irqsave(&q_ctx->rdy_spinlock, flags); 782 list_add_tail(&b->list, &q_ctx->rdy_queue); 783 q_ctx->num_rdy++; 784 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags); 785 } 786 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue); 787 788 /* Videobuf2 ioctl helpers */ 789 790 int v4l2_m2m_ioctl_reqbufs(struct file *file, void *priv, 791 struct v4l2_requestbuffers *rb) 792 { 793 struct v4l2_fh *fh = file->private_data; 794 795 return v4l2_m2m_reqbufs(file, fh->m2m_ctx, rb); 796 } 797 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_reqbufs); 798 799 int v4l2_m2m_ioctl_create_bufs(struct file *file, void *priv, 800 struct v4l2_create_buffers *create) 801 { 802 struct v4l2_fh *fh = file->private_data; 803 804 return v4l2_m2m_create_bufs(file, fh->m2m_ctx, create); 805 } 806 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_create_bufs); 807 808 int v4l2_m2m_ioctl_querybuf(struct file *file, void *priv, 809 struct v4l2_buffer *buf) 810 { 811 struct v4l2_fh *fh = file->private_data; 812 813 return v4l2_m2m_querybuf(file, fh->m2m_ctx, buf); 814 } 815 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_querybuf); 816 817 int v4l2_m2m_ioctl_qbuf(struct file *file, void *priv, 818 struct v4l2_buffer *buf) 819 { 820 struct v4l2_fh *fh = file->private_data; 821 822 return v4l2_m2m_qbuf(file, fh->m2m_ctx, buf); 823 } 824 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_qbuf); 825 826 int v4l2_m2m_ioctl_dqbuf(struct file *file, void *priv, 827 struct v4l2_buffer *buf) 828 { 829 struct v4l2_fh *fh = file->private_data; 830 831 return v4l2_m2m_dqbuf(file, fh->m2m_ctx, buf); 832 } 833 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_dqbuf); 834 835 int v4l2_m2m_ioctl_prepare_buf(struct file *file, void *priv, 836 struct v4l2_buffer *buf) 837 { 838 struct v4l2_fh *fh = file->private_data; 839 840 return v4l2_m2m_prepare_buf(file, fh->m2m_ctx, buf); 841 } 842 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_prepare_buf); 843 844 int v4l2_m2m_ioctl_expbuf(struct file *file, void *priv, 845 struct v4l2_exportbuffer *eb) 846 { 847 struct v4l2_fh *fh = file->private_data; 848 849 return v4l2_m2m_expbuf(file, fh->m2m_ctx, eb); 850 } 851 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_expbuf); 852 853 int v4l2_m2m_ioctl_streamon(struct file *file, void *priv, 854 enum v4l2_buf_type type) 855 { 856 struct v4l2_fh *fh = file->private_data; 857 858 return v4l2_m2m_streamon(file, fh->m2m_ctx, type); 859 } 860 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_streamon); 861 862 int v4l2_m2m_ioctl_streamoff(struct file *file, void *priv, 863 enum v4l2_buf_type type) 864 { 865 struct v4l2_fh *fh = file->private_data; 866 867 return v4l2_m2m_streamoff(file, fh->m2m_ctx, type); 868 } 869 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_streamoff); 870 871 /* 872 * v4l2_file_operations helpers. It is assumed here same lock is used 873 * for the output and the capture buffer queue. 874 */ 875 876 int v4l2_m2m_fop_mmap(struct file *file, struct vm_area_struct *vma) 877 { 878 struct v4l2_fh *fh = file->private_data; 879 880 return v4l2_m2m_mmap(file, fh->m2m_ctx, vma); 881 } 882 EXPORT_SYMBOL_GPL(v4l2_m2m_fop_mmap); 883 884 unsigned int v4l2_m2m_fop_poll(struct file *file, poll_table *wait) 885 { 886 struct v4l2_fh *fh = file->private_data; 887 struct v4l2_m2m_ctx *m2m_ctx = fh->m2m_ctx; 888 unsigned int ret; 889 890 if (m2m_ctx->q_lock) 891 mutex_lock(m2m_ctx->q_lock); 892 893 ret = v4l2_m2m_poll(file, m2m_ctx, wait); 894 895 if (m2m_ctx->q_lock) 896 mutex_unlock(m2m_ctx->q_lock); 897 898 return ret; 899 } 900 EXPORT_SYMBOL_GPL(v4l2_m2m_fop_poll); 901 902