| 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| 2 | /* |
| 3 | * uvc_queue.c -- USB Video Class driver - Buffers management |
| 4 | * |
| 5 | * Copyright (C) 2005-2010 |
| 6 | * Laurent Pinchart (laurent.pinchart@ideasonboard.com) |
| 7 | */ |
| 8 | |
| 9 | #include <linux/atomic.h> |
| 10 | #include <linux/kernel.h> |
| 11 | #include <linux/mm.h> |
| 12 | #include <linux/list.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/usb.h> |
| 15 | #include <linux/videodev2.h> |
| 16 | #include <linux/vmalloc.h> |
| 17 | #include <linux/wait.h> |
| 18 | #include <media/videobuf2-v4l2.h> |
| 19 | #include <media/videobuf2-vmalloc.h> |
| 20 | |
| 21 | #include "uvcvideo.h" |
| 22 | |
| 23 | /* ------------------------------------------------------------------------ |
| 24 | * Video buffers queue management. |
| 25 | * |
| 26 | * Video queues is initialized by uvc_queue_init(). The function performs |
| 27 | * basic initialization of the uvc_video_queue struct and never fails. |
| 28 | * |
| 29 | * Video buffers are managed by videobuf2. The driver uses a mutex to protect |
| 30 | * the videobuf2 queue operations by serializing calls to videobuf2 and a |
| 31 | * spinlock to protect the IRQ queue that holds the buffers to be processed by |
| 32 | * the driver. |
| 33 | */ |
| 34 | |
| 35 | static inline struct uvc_buffer *uvc_vbuf_to_buffer(struct vb2_v4l2_buffer *buf) |
| 36 | { |
| 37 | return container_of(buf, struct uvc_buffer, buf); |
| 38 | } |
| 39 | |
| 40 | /* |
| 41 | * Return all queued buffers to videobuf2 in the requested state. |
| 42 | * |
| 43 | * This function must be called with the queue spinlock held. |
| 44 | */ |
| 45 | static void uvc_queue_return_buffers(struct uvc_video_queue *queue, |
| 46 | enum uvc_buffer_state state) |
| 47 | { |
| 48 | enum vb2_buffer_state vb2_state = state == UVC_BUF_STATE_ERROR |
| 49 | ? VB2_BUF_STATE_ERROR |
| 50 | : VB2_BUF_STATE_QUEUED; |
| 51 | |
| 52 | while (!list_empty(&queue->irqqueue)) { |
| 53 | struct uvc_buffer *buf = list_first_entry(&queue->irqqueue, |
| 54 | struct uvc_buffer, |
| 55 | queue); |
| 56 | list_del(&buf->queue); |
| 57 | buf->state = state; |
| 58 | vb2_buffer_done(&buf->buf.vb2_buf, vb2_state); |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | /* ----------------------------------------------------------------------------- |
| 63 | * videobuf2 queue operations |
| 64 | */ |
| 65 | |
| 66 | static int uvc_queue_setup(struct vb2_queue *vq, |
| 67 | unsigned int *nbuffers, unsigned int *nplanes, |
| 68 | unsigned int sizes[], struct device *alloc_devs[]) |
| 69 | { |
| 70 | struct uvc_video_queue *queue = vb2_get_drv_priv(vq); |
| 71 | struct uvc_streaming *stream; |
| 72 | unsigned int size; |
| 73 | |
| 74 | switch (vq->type) { |
| 75 | case V4L2_BUF_TYPE_META_CAPTURE: |
| 76 | size = UVC_METADATA_BUF_SIZE; |
| 77 | break; |
| 78 | |
| 79 | default: |
| 80 | stream = uvc_queue_to_stream(queue); |
| 81 | size = stream->ctrl.dwMaxVideoFrameSize; |
| 82 | break; |
| 83 | } |
| 84 | |
| 85 | /* |
| 86 | * When called with plane sizes, validate them. The driver supports |
| 87 | * single planar formats only, and requires buffers to be large enough |
| 88 | * to store a complete frame. |
| 89 | */ |
| 90 | if (*nplanes) |
| 91 | return *nplanes != 1 || sizes[0] < size ? -EINVAL : 0; |
| 92 | |
| 93 | *nplanes = 1; |
| 94 | sizes[0] = size; |
| 95 | return 0; |
| 96 | } |
| 97 | |
| 98 | static int uvc_buffer_prepare(struct vb2_buffer *vb) |
| 99 | { |
| 100 | struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb); |
| 101 | struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue); |
| 102 | struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf); |
| 103 | |
| 104 | if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT && |
| 105 | vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) { |
| 106 | uvc_dbg(uvc_queue_to_stream(queue)->dev, CAPTURE, |
| 107 | "[E] Bytes used out of bounds\n"); |
| 108 | return -EINVAL; |
| 109 | } |
| 110 | |
| 111 | if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED)) |
| 112 | return -ENODEV; |
| 113 | |
| 114 | buf->state = UVC_BUF_STATE_QUEUED; |
| 115 | buf->error = 0; |
| 116 | buf->mem = vb2_plane_vaddr(vb, 0); |
| 117 | buf->length = vb2_plane_size(vb, 0); |
| 118 | if (vb->type != V4L2_BUF_TYPE_VIDEO_OUTPUT) |
| 119 | buf->bytesused = 0; |
| 120 | else |
| 121 | buf->bytesused = vb2_get_plane_payload(vb, 0); |
| 122 | |
| 123 | return 0; |
| 124 | } |
| 125 | |
| 126 | static void uvc_buffer_queue(struct vb2_buffer *vb) |
| 127 | { |
| 128 | struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb); |
| 129 | struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue); |
| 130 | struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf); |
| 131 | unsigned long flags; |
| 132 | |
| 133 | spin_lock_irqsave(&queue->irqlock, flags); |
| 134 | if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) { |
| 135 | kref_init(&buf->ref); |
| 136 | list_add_tail(&buf->queue, &queue->irqqueue); |
| 137 | } else { |
| 138 | /* |
| 139 | * If the device is disconnected return the buffer to userspace |
| 140 | * directly. The next QBUF call will fail with -ENODEV. |
| 141 | */ |
| 142 | buf->state = UVC_BUF_STATE_ERROR; |
| 143 | vb2_buffer_done(vb, VB2_BUF_STATE_ERROR); |
| 144 | } |
| 145 | |
| 146 | spin_unlock_irqrestore(&queue->irqlock, flags); |
| 147 | } |
| 148 | |
| 149 | static void uvc_buffer_finish(struct vb2_buffer *vb) |
| 150 | { |
| 151 | struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb); |
| 152 | struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue); |
| 153 | struct uvc_streaming *stream = uvc_queue_to_stream(queue); |
| 154 | struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf); |
| 155 | |
| 156 | if (vb->state == VB2_BUF_STATE_DONE) |
| 157 | uvc_video_clock_update(stream, vbuf, buf); |
| 158 | } |
| 159 | |
| 160 | static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count) |
| 161 | { |
| 162 | struct uvc_video_queue *queue = vb2_get_drv_priv(vq); |
| 163 | struct uvc_streaming *stream = uvc_queue_to_stream(queue); |
| 164 | int ret; |
| 165 | |
| 166 | lockdep_assert_irqs_enabled(); |
| 167 | |
| 168 | queue->buf_used = 0; |
| 169 | |
| 170 | ret = uvc_video_start_streaming(stream); |
| 171 | if (ret == 0) |
| 172 | return 0; |
| 173 | |
| 174 | spin_lock_irq(&queue->irqlock); |
| 175 | uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED); |
| 176 | spin_unlock_irq(&queue->irqlock); |
| 177 | |
| 178 | return ret; |
| 179 | } |
| 180 | |
| 181 | static void uvc_stop_streaming(struct vb2_queue *vq) |
| 182 | { |
| 183 | struct uvc_video_queue *queue = vb2_get_drv_priv(vq); |
| 184 | |
| 185 | lockdep_assert_irqs_enabled(); |
| 186 | |
| 187 | if (vq->type != V4L2_BUF_TYPE_META_CAPTURE) |
| 188 | uvc_video_stop_streaming(uvc_queue_to_stream(queue)); |
| 189 | |
| 190 | spin_lock_irq(&queue->irqlock); |
| 191 | uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR); |
| 192 | spin_unlock_irq(&queue->irqlock); |
| 193 | } |
| 194 | |
| 195 | static const struct vb2_ops uvc_queue_qops = { |
| 196 | .queue_setup = uvc_queue_setup, |
| 197 | .buf_prepare = uvc_buffer_prepare, |
| 198 | .buf_queue = uvc_buffer_queue, |
| 199 | .buf_finish = uvc_buffer_finish, |
| 200 | .wait_prepare = vb2_ops_wait_prepare, |
| 201 | .wait_finish = vb2_ops_wait_finish, |
| 202 | .start_streaming = uvc_start_streaming, |
| 203 | .stop_streaming = uvc_stop_streaming, |
| 204 | }; |
| 205 | |
| 206 | static const struct vb2_ops uvc_meta_queue_qops = { |
| 207 | .queue_setup = uvc_queue_setup, |
| 208 | .buf_prepare = uvc_buffer_prepare, |
| 209 | .buf_queue = uvc_buffer_queue, |
| 210 | .wait_prepare = vb2_ops_wait_prepare, |
| 211 | .wait_finish = vb2_ops_wait_finish, |
| 212 | .stop_streaming = uvc_stop_streaming, |
| 213 | }; |
| 214 | |
| 215 | int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type, |
| 216 | int drop_corrupted) |
| 217 | { |
| 218 | int ret; |
| 219 | |
| 220 | queue->queue.type = type; |
| 221 | queue->queue.io_modes = VB2_MMAP | VB2_USERPTR; |
| 222 | queue->queue.drv_priv = queue; |
| 223 | queue->queue.buf_struct_size = sizeof(struct uvc_buffer); |
| 224 | queue->queue.mem_ops = &vb2_vmalloc_memops; |
| 225 | queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC |
| 226 | | V4L2_BUF_FLAG_TSTAMP_SRC_SOE; |
| 227 | queue->queue.lock = &queue->mutex; |
| 228 | |
| 229 | switch (type) { |
| 230 | case V4L2_BUF_TYPE_META_CAPTURE: |
| 231 | queue->queue.ops = &uvc_meta_queue_qops; |
| 232 | break; |
| 233 | default: |
| 234 | queue->queue.io_modes |= VB2_DMABUF; |
| 235 | queue->queue.ops = &uvc_queue_qops; |
| 236 | break; |
| 237 | } |
| 238 | |
| 239 | ret = vb2_queue_init(&queue->queue); |
| 240 | if (ret) |
| 241 | return ret; |
| 242 | |
| 243 | mutex_init(&queue->mutex); |
| 244 | spin_lock_init(&queue->irqlock); |
| 245 | INIT_LIST_HEAD(&queue->irqqueue); |
| 246 | queue->flags = drop_corrupted ? UVC_QUEUE_DROP_CORRUPTED : 0; |
| 247 | |
| 248 | return 0; |
| 249 | } |
| 250 | |
| 251 | void uvc_queue_release(struct uvc_video_queue *queue) |
| 252 | { |
| 253 | mutex_lock(&queue->mutex); |
| 254 | vb2_queue_release(&queue->queue); |
| 255 | mutex_unlock(&queue->mutex); |
| 256 | } |
| 257 | |
| 258 | /* ----------------------------------------------------------------------------- |
| 259 | * V4L2 queue operations |
| 260 | */ |
| 261 | |
| 262 | int uvc_request_buffers(struct uvc_video_queue *queue, |
| 263 | struct v4l2_requestbuffers *rb) |
| 264 | { |
| 265 | int ret; |
| 266 | |
| 267 | mutex_lock(&queue->mutex); |
| 268 | ret = vb2_reqbufs(&queue->queue, rb); |
| 269 | mutex_unlock(&queue->mutex); |
| 270 | |
| 271 | return ret ? ret : rb->count; |
| 272 | } |
| 273 | |
| 274 | int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf) |
| 275 | { |
| 276 | int ret; |
| 277 | |
| 278 | mutex_lock(&queue->mutex); |
| 279 | ret = vb2_querybuf(&queue->queue, buf); |
| 280 | mutex_unlock(&queue->mutex); |
| 281 | |
| 282 | return ret; |
| 283 | } |
| 284 | |
| 285 | int uvc_create_buffers(struct uvc_video_queue *queue, |
| 286 | struct v4l2_create_buffers *cb) |
| 287 | { |
| 288 | int ret; |
| 289 | |
| 290 | mutex_lock(&queue->mutex); |
| 291 | ret = vb2_create_bufs(&queue->queue, cb); |
| 292 | mutex_unlock(&queue->mutex); |
| 293 | |
| 294 | return ret; |
| 295 | } |
| 296 | |
| 297 | int uvc_queue_buffer(struct uvc_video_queue *queue, |
| 298 | struct media_device *mdev, struct v4l2_buffer *buf) |
| 299 | { |
| 300 | int ret; |
| 301 | |
| 302 | mutex_lock(&queue->mutex); |
| 303 | ret = vb2_qbuf(&queue->queue, mdev, buf); |
| 304 | mutex_unlock(&queue->mutex); |
| 305 | |
| 306 | return ret; |
| 307 | } |
| 308 | |
| 309 | int uvc_export_buffer(struct uvc_video_queue *queue, |
| 310 | struct v4l2_exportbuffer *exp) |
| 311 | { |
| 312 | int ret; |
| 313 | |
| 314 | mutex_lock(&queue->mutex); |
| 315 | ret = vb2_expbuf(&queue->queue, exp); |
| 316 | mutex_unlock(&queue->mutex); |
| 317 | |
| 318 | return ret; |
| 319 | } |
| 320 | |
| 321 | int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf, |
| 322 | int nonblocking) |
| 323 | { |
| 324 | int ret; |
| 325 | |
| 326 | mutex_lock(&queue->mutex); |
| 327 | ret = vb2_dqbuf(&queue->queue, buf, nonblocking); |
| 328 | mutex_unlock(&queue->mutex); |
| 329 | |
| 330 | return ret; |
| 331 | } |
| 332 | |
| 333 | int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type) |
| 334 | { |
| 335 | int ret; |
| 336 | |
| 337 | mutex_lock(&queue->mutex); |
| 338 | ret = vb2_streamon(&queue->queue, type); |
| 339 | mutex_unlock(&queue->mutex); |
| 340 | |
| 341 | return ret; |
| 342 | } |
| 343 | |
| 344 | int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type) |
| 345 | { |
| 346 | int ret; |
| 347 | |
| 348 | mutex_lock(&queue->mutex); |
| 349 | ret = vb2_streamoff(&queue->queue, type); |
| 350 | mutex_unlock(&queue->mutex); |
| 351 | |
| 352 | return ret; |
| 353 | } |
| 354 | |
| 355 | int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma) |
| 356 | { |
| 357 | return vb2_mmap(&queue->queue, vma); |
| 358 | } |
| 359 | |
| 360 | #ifndef CONFIG_MMU |
| 361 | unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue, |
| 362 | unsigned long pgoff) |
| 363 | { |
| 364 | return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0); |
| 365 | } |
| 366 | #endif |
| 367 | |
| 368 | __poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file, |
| 369 | poll_table *wait) |
| 370 | { |
| 371 | __poll_t ret; |
| 372 | |
| 373 | mutex_lock(&queue->mutex); |
| 374 | ret = vb2_poll(&queue->queue, file, wait); |
| 375 | mutex_unlock(&queue->mutex); |
| 376 | |
| 377 | return ret; |
| 378 | } |
| 379 | |
| 380 | /* ----------------------------------------------------------------------------- |
| 381 | * |
| 382 | */ |
| 383 | |
| 384 | /* |
| 385 | * Check if buffers have been allocated. |
| 386 | */ |
| 387 | int uvc_queue_allocated(struct uvc_video_queue *queue) |
| 388 | { |
| 389 | int allocated; |
| 390 | |
| 391 | mutex_lock(&queue->mutex); |
| 392 | allocated = vb2_is_busy(&queue->queue); |
| 393 | mutex_unlock(&queue->mutex); |
| 394 | |
| 395 | return allocated; |
| 396 | } |
| 397 | |
| 398 | /* |
| 399 | * Cancel the video buffers queue. |
| 400 | * |
| 401 | * Cancelling the queue marks all buffers on the irq queue as erroneous, |
| 402 | * wakes them up and removes them from the queue. |
| 403 | * |
| 404 | * If the disconnect parameter is set, further calls to uvc_queue_buffer will |
| 405 | * fail with -ENODEV. |
| 406 | * |
| 407 | * This function acquires the irq spinlock and can be called from interrupt |
| 408 | * context. |
| 409 | */ |
| 410 | void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect) |
| 411 | { |
| 412 | unsigned long flags; |
| 413 | |
| 414 | spin_lock_irqsave(&queue->irqlock, flags); |
| 415 | uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR); |
| 416 | /* |
| 417 | * This must be protected by the irqlock spinlock to avoid race |
| 418 | * conditions between uvc_buffer_queue and the disconnection event that |
| 419 | * could result in an interruptible wait in uvc_dequeue_buffer. Do not |
| 420 | * blindly replace this logic by checking for the UVC_QUEUE_DISCONNECTED |
| 421 | * state outside the queue code. |
| 422 | */ |
| 423 | if (disconnect) |
| 424 | queue->flags |= UVC_QUEUE_DISCONNECTED; |
| 425 | spin_unlock_irqrestore(&queue->irqlock, flags); |
| 426 | } |
| 427 | |
| 428 | /* |
| 429 | * uvc_queue_get_current_buffer: Obtain the current working output buffer |
| 430 | * |
| 431 | * Buffers may span multiple packets, and even URBs, therefore the active buffer |
| 432 | * remains on the queue until the EOF marker. |
| 433 | */ |
| 434 | static struct uvc_buffer * |
| 435 | __uvc_queue_get_current_buffer(struct uvc_video_queue *queue) |
| 436 | { |
| 437 | if (list_empty(&queue->irqqueue)) |
| 438 | return NULL; |
| 439 | |
| 440 | return list_first_entry(&queue->irqqueue, struct uvc_buffer, queue); |
| 441 | } |
| 442 | |
| 443 | struct uvc_buffer *uvc_queue_get_current_buffer(struct uvc_video_queue *queue) |
| 444 | { |
| 445 | struct uvc_buffer *nextbuf; |
| 446 | unsigned long flags; |
| 447 | |
| 448 | spin_lock_irqsave(&queue->irqlock, flags); |
| 449 | nextbuf = __uvc_queue_get_current_buffer(queue); |
| 450 | spin_unlock_irqrestore(&queue->irqlock, flags); |
| 451 | |
| 452 | return nextbuf; |
| 453 | } |
| 454 | |
| 455 | /* |
| 456 | * uvc_queue_buffer_requeue: Requeue a buffer on our internal irqqueue |
| 457 | * |
| 458 | * Reuse a buffer through our internal queue without the need to 'prepare'. |
| 459 | * The buffer will be returned to userspace through the uvc_buffer_queue call if |
| 460 | * the device has been disconnected. |
| 461 | */ |
| 462 | static void uvc_queue_buffer_requeue(struct uvc_video_queue *queue, |
| 463 | struct uvc_buffer *buf) |
| 464 | { |
| 465 | buf->error = 0; |
| 466 | buf->state = UVC_BUF_STATE_QUEUED; |
| 467 | buf->bytesused = 0; |
| 468 | vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0); |
| 469 | |
| 470 | uvc_buffer_queue(&buf->buf.vb2_buf); |
| 471 | } |
| 472 | |
| 473 | static void uvc_queue_buffer_complete(struct kref *ref) |
| 474 | { |
| 475 | struct uvc_buffer *buf = container_of(ref, struct uvc_buffer, ref); |
| 476 | struct vb2_buffer *vb = &buf->buf.vb2_buf; |
| 477 | struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue); |
| 478 | |
| 479 | if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) { |
| 480 | uvc_queue_buffer_requeue(queue, buf); |
| 481 | return; |
| 482 | } |
| 483 | |
| 484 | buf->state = buf->error ? UVC_BUF_STATE_ERROR : UVC_BUF_STATE_DONE; |
| 485 | vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused); |
| 486 | vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE); |
| 487 | } |
| 488 | |
| 489 | /* |
| 490 | * Release a reference on the buffer. Complete the buffer when the last |
| 491 | * reference is released. |
| 492 | */ |
| 493 | void uvc_queue_buffer_release(struct uvc_buffer *buf) |
| 494 | { |
| 495 | kref_put(&buf->ref, uvc_queue_buffer_complete); |
| 496 | } |
| 497 | |
| 498 | /* |
| 499 | * Remove this buffer from the queue. Lifetime will persist while async actions |
| 500 | * are still running (if any), and uvc_queue_buffer_release will give the buffer |
| 501 | * back to VB2 when all users have completed. |
| 502 | */ |
| 503 | struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue, |
| 504 | struct uvc_buffer *buf) |
| 505 | { |
| 506 | struct uvc_buffer *nextbuf; |
| 507 | unsigned long flags; |
| 508 | |
| 509 | spin_lock_irqsave(&queue->irqlock, flags); |
| 510 | list_del(&buf->queue); |
| 511 | nextbuf = __uvc_queue_get_current_buffer(queue); |
| 512 | spin_unlock_irqrestore(&queue->irqlock, flags); |
| 513 | |
| 514 | uvc_queue_buffer_release(buf); |
| 515 | |
| 516 | return nextbuf; |
| 517 | } |