drivers/media/common/videobuf2/videobuf2-core.c

   1 /*
   2  * videobuf2-core.c - video buffer 2 core framework
   3  *
   4  * Copyright (C) 2010 Samsung Electronics
   5  *
   6  * Author: Pawel Osciak <pawel@osciak.com>
   7  *         Marek Szyprowski <m.szyprowski@samsung.com>
   8  *
   9  * The vb2_thread implementation was based on code from videobuf-dvb.c:
  10  *      (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation.
  15  */
  16
  17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  18
  19 #include <linux/err.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/mm.h>
  23 #include <linux/poll.h>
  24 #include <linux/slab.h>
  25 #include <linux/sched.h>
  26 #include <linux/freezer.h>
  27 #include <linux/kthread.h>
  28
  29 #include <media/videobuf2-core.h>
  30 #include <media/v4l2-mc.h>
  31
  32 #include <trace/events/vb2.h>
  33
  34 static int debug;
  35 module_param(debug, int, 0644);
  36
  37 #define dprintk(level, fmt, arg...)                             \
  38         do {                                                    \
  39                 if (debug >= level)                             \
  40                         pr_info("%s: " fmt, __func__, ## arg);  \
  41         } while (0)
  42
  43 #ifdef CONFIG_VIDEO_ADV_DEBUG
  44
  45 /*
  46  * If advanced debugging is on, then count how often each op is called
  47  * successfully, which can either be per-buffer or per-queue.
  48  *
  49  * This makes it easy to check that the 'init' and 'cleanup'
  50  * (and variations thereof) stay balanced.
  51  */
  52
  53 #define log_memop(vb, op)                                               \
  54         dprintk(2, "call_memop(%p, %d, %s)%s\n",                        \
  55                 (vb)->vb2_queue, (vb)->index, #op,                      \
  56                 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
  57
  58 #define call_memop(vb, op, args...)                                     \
  59 ({                                                                      \
  60         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  61         int err;                                                        \
  62                                                                         \
  63         log_memop(vb, op);                                              \
  64         err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0;              \
  65         if (!err)                                                       \
  66                 (vb)->cnt_mem_ ## op++;                                 \
  67         err;                                                            \
  68 })
  69
  70 #define call_ptr_memop(vb, op, args...)                                 \
  71 ({                                                                      \
  72         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  73         void *ptr;                                                      \
  74                                                                         \
  75         log_memop(vb, op);                                              \
  76         ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL;           \
  77         if (!IS_ERR_OR_NULL(ptr))                                       \
  78                 (vb)->cnt_mem_ ## op++;                                 \
  79         ptr;                                                            \
  80 })
  81
  82 #define call_void_memop(vb, op, args...)                                \
  83 ({                                                                      \
  84         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  85                                                                         \
  86         log_memop(vb, op);                                              \
  87         if (_q->mem_ops->op)                                            \
  88                 _q->mem_ops->op(args);                                  \
  89         (vb)->cnt_mem_ ## op++;                                         \
  90 })
  91
  92 #define log_qop(q, op)                                                  \
  93         dprintk(2, "call_qop(%p, %s)%s\n", q, #op,                      \
  94                 (q)->ops->op ? "" : " (nop)")
  95
  96 #define call_qop(q, op, args...)                                        \
  97 ({                                                                      \
  98         int err;                                                        \
  99                                                                         \
 100         log_qop(q, op);                                                 \
 101         err = (q)->ops->op ? (q)->ops->op(args) : 0;                    \
 102         if (!err)                                                       \
 103                 (q)->cnt_ ## op++;                                      \
 104         err;                                                            \
 105 })
 106
 107 #define call_void_qop(q, op, args...)                                   \
 108 ({                                                                      \
 109         log_qop(q, op);                                                 \
 110         if ((q)->ops->op)                                               \
 111                 (q)->ops->op(args);                                     \
 112         (q)->cnt_ ## op++;                                              \
 113 })
 114
 115 #define log_vb_qop(vb, op, args...)                                     \
 116         dprintk(2, "call_vb_qop(%p, %d, %s)%s\n",                       \
 117                 (vb)->vb2_queue, (vb)->index, #op,                      \
 118                 (vb)->vb2_queue->ops->op ? "" : " (nop)")
 119
 120 #define call_vb_qop(vb, op, args...)                                    \
 121 ({                                                                      \
 122         int err;                                                        \
 123                                                                         \
 124         log_vb_qop(vb, op);                                             \
 125         err = (vb)->vb2_queue->ops->op ?                                \
 126                 (vb)->vb2_queue->ops->op(args) : 0;                     \
 127         if (!err)                                                       \
 128                 (vb)->cnt_ ## op++;                                     \
 129         err;                                                            \
 130 })
 131
 132 #define call_void_vb_qop(vb, op, args...)                               \
 133 ({                                                                      \
 134         log_vb_qop(vb, op);                                             \
 135         if ((vb)->vb2_queue->ops->op)                                   \
 136                 (vb)->vb2_queue->ops->op(args);                         \
 137         (vb)->cnt_ ## op++;                                             \
 138 })
 139
 140 #else
 141
 142 #define call_memop(vb, op, args...)                                     \
 143         ((vb)->vb2_queue->mem_ops->op ?                                 \
 144                 (vb)->vb2_queue->mem_ops->op(args) : 0)
 145
 146 #define call_ptr_memop(vb, op, args...)                                 \
 147         ((vb)->vb2_queue->mem_ops->op ?                                 \
 148                 (vb)->vb2_queue->mem_ops->op(args) : NULL)
 149
 150 #define call_void_memop(vb, op, args...)                                \
 151         do {                                                            \
 152                 if ((vb)->vb2_queue->mem_ops->op)                       \
 153                         (vb)->vb2_queue->mem_ops->op(args);             \
 154         } while (0)
 155
 156 #define call_qop(q, op, args...)                                        \
 157         ((q)->ops->op ? (q)->ops->op(args) : 0)
 158
 159 #define call_void_qop(q, op, args...)                                   \
 160         do {                                                            \
 161                 if ((q)->ops->op)                                       \
 162                         (q)->ops->op(args);                             \
 163         } while (0)
 164
 165 #define call_vb_qop(vb, op, args...)                                    \
 166         ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
 167
 168 #define call_void_vb_qop(vb, op, args...)                               \
 169         do {                                                            \
 170                 if ((vb)->vb2_queue->ops->op)                           \
 171                         (vb)->vb2_queue->ops->op(args);                 \
 172         } while (0)
 173
 174 #endif
 175
 176 #define call_bufop(q, op, args...)                                      \
 177 ({                                                                      \
 178         int ret = 0;                                                    \
 179         if (q && q->buf_ops && q->buf_ops->op)                          \
 180                 ret = q->buf_ops->op(args);                             \
 181         ret;                                                            \
 182 })
 183
 184 #define call_void_bufop(q, op, args...)                                 \
 185 ({                                                                      \
 186         if (q && q->buf_ops && q->buf_ops->op)                          \
 187                 q->buf_ops->op(args);                                   \
 188 })
 189
 190 static void __vb2_queue_cancel(struct vb2_queue *q);
 191 static void __enqueue_in_driver(struct vb2_buffer *vb);
 192
 193 /*
 194  * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
 195  */
 196 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
 197 {
 198         struct vb2_queue *q = vb->vb2_queue;
 199         void *mem_priv;
 200         int plane;
 201         int ret = -ENOMEM;
 202
 203         /*
 204          * Allocate memory for all planes in this buffer
 205          * NOTE: mmapped areas should be page aligned
 206          */
 207         for (plane = 0; plane < vb->num_planes; ++plane) {
 208                 unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
 209
 210                 mem_priv = call_ptr_memop(vb, alloc,
 211                                 q->alloc_devs[plane] ? : q->dev,
 212                                 q->dma_attrs, size, q->dma_dir, q->gfp_flags);
 213                 if (IS_ERR_OR_NULL(mem_priv)) {
 214                         if (mem_priv)
 215                                 ret = PTR_ERR(mem_priv);
 216                         goto free;
 217                 }
 218
 219                 /* Associate allocator private data with this plane */
 220                 vb->planes[plane].mem_priv = mem_priv;
 221         }
 222
 223         return 0;
 224 free:
 225         /* Free already allocated memory if one of the allocations failed */
 226         for (; plane > 0; --plane) {
 227                 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
 228                 vb->planes[plane - 1].mem_priv = NULL;
 229         }
 230
 231         return ret;
 232 }
 233
 234 /*
 235  * __vb2_buf_mem_free() - free memory of the given buffer
 236  */
 237 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
 238 {
 239         unsigned int plane;
 240
 241         for (plane = 0; plane < vb->num_planes; ++plane) {
 242                 call_void_memop(vb, put, vb->planes[plane].mem_priv);
 243                 vb->planes[plane].mem_priv = NULL;
 244                 dprintk(3, "freed plane %d of buffer %d\n", plane, vb->index);
 245         }
 246 }
 247
 248 /*
 249  * __vb2_buf_userptr_put() - release userspace memory associated with
 250  * a USERPTR buffer
 251  */
 252 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
 253 {
 254         unsigned int plane;
 255
 256         for (plane = 0; plane < vb->num_planes; ++plane) {
 257                 if (vb->planes[plane].mem_priv)
 258                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
 259                 vb->planes[plane].mem_priv = NULL;
 260         }
 261 }
 262
 263 /*
 264  * __vb2_plane_dmabuf_put() - release memory associated with
 265  * a DMABUF shared plane
 266  */
 267 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
 268 {
 269         if (!p->mem_priv)
 270                 return;
 271
 272         if (p->dbuf_mapped)
 273                 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
 274
 275         call_void_memop(vb, detach_dmabuf, p->mem_priv);
 276         dma_buf_put(p->dbuf);
 277         p->mem_priv = NULL;
 278         p->dbuf = NULL;
 279         p->dbuf_mapped = 0;
 280 }
 281
 282 /*
 283  * __vb2_buf_dmabuf_put() - release memory associated with
 284  * a DMABUF shared buffer
 285  */
 286 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
 287 {
 288         unsigned int plane;
 289
 290         for (plane = 0; plane < vb->num_planes; ++plane)
 291                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
 292 }
 293
 294 /*
 295  * __setup_offsets() - setup unique offsets ("cookies") for every plane in
 296  * the buffer.
 297  */
 298 static void __setup_offsets(struct vb2_buffer *vb)
 299 {
 300         struct vb2_queue *q = vb->vb2_queue;
 301         unsigned int plane;
 302         unsigned long off = 0;
 303
 304         if (vb->index) {
 305                 struct vb2_buffer *prev = q->bufs[vb->index - 1];
 306                 struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
 307
 308                 off = PAGE_ALIGN(p->m.offset + p->length);
 309         }
 310
 311         for (plane = 0; plane < vb->num_planes; ++plane) {
 312                 vb->planes[plane].m.offset = off;
 313
 314                 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
 315                                 vb->index, plane, off);
 316
 317                 off += vb->planes[plane].length;
 318                 off = PAGE_ALIGN(off);
 319         }
 320 }
 321
 322 /*
 323  * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
 324  * video buffer memory for all buffers/planes on the queue and initializes the
 325  * queue
 326  *
 327  * Returns the number of buffers successfully allocated.
 328  */
 329 static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
 330                              unsigned int num_buffers, unsigned int num_planes,
 331                              const unsigned plane_sizes[VB2_MAX_PLANES])
 332 {
 333         unsigned int buffer, plane;
 334         struct vb2_buffer *vb;
 335         int ret;
 336
 337         /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
 338         num_buffers = min_t(unsigned int, num_buffers,
 339                             VB2_MAX_FRAME - q->num_buffers);
 340
 341         for (buffer = 0; buffer < num_buffers; ++buffer) {
 342                 /* Allocate videobuf buffer structures */
 343                 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
 344                 if (!vb) {
 345                         dprintk(1, "memory alloc for buffer struct failed\n");
 346                         break;
 347                 }
 348
 349                 vb->state = VB2_BUF_STATE_DEQUEUED;
 350                 vb->vb2_queue = q;
 351                 vb->num_planes = num_planes;
 352                 vb->index = q->num_buffers + buffer;
 353                 vb->type = q->type;
 354                 vb->memory = memory;
 355                 for (plane = 0; plane < num_planes; ++plane) {
 356                         vb->planes[plane].length = plane_sizes[plane];
 357                         vb->planes[plane].min_length = plane_sizes[plane];
 358                 }
 359                 q->bufs[vb->index] = vb;
 360
 361                 /* Allocate video buffer memory for the MMAP type */
 362                 if (memory == VB2_MEMORY_MMAP) {
 363                         ret = __vb2_buf_mem_alloc(vb);
 364                         if (ret) {
 365                                 dprintk(1, "failed allocating memory for buffer %d\n",
 366                                         buffer);
 367                                 q->bufs[vb->index] = NULL;
 368                                 kfree(vb);
 369                                 break;
 370                         }
 371                         __setup_offsets(vb);
 372                         /*
 373                          * Call the driver-provided buffer initialization
 374                          * callback, if given. An error in initialization
 375                          * results in queue setup failure.
 376                          */
 377                         ret = call_vb_qop(vb, buf_init, vb);
 378                         if (ret) {
 379                                 dprintk(1, "buffer %d %p initialization failed\n",
 380                                         buffer, vb);
 381                                 __vb2_buf_mem_free(vb);
 382                                 q->bufs[vb->index] = NULL;
 383                                 kfree(vb);
 384                                 break;
 385                         }
 386                 }
 387         }
 388
 389         dprintk(1, "allocated %d buffers, %d plane(s) each\n",
 390                         buffer, num_planes);
 391
 392         return buffer;
 393 }
 394
 395 /*
 396  * __vb2_free_mem() - release all video buffer memory for a given queue
 397  */
 398 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
 399 {
 400         unsigned int buffer;
 401         struct vb2_buffer *vb;
 402
 403         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 404              ++buffer) {
 405                 vb = q->bufs[buffer];
 406                 if (!vb)
 407                         continue;
 408
 409                 /* Free MMAP buffers or release USERPTR buffers */
 410                 if (q->memory == VB2_MEMORY_MMAP)
 411                         __vb2_buf_mem_free(vb);
 412                 else if (q->memory == VB2_MEMORY_DMABUF)
 413                         __vb2_buf_dmabuf_put(vb);
 414                 else
 415                         __vb2_buf_userptr_put(vb);
 416         }
 417 }
 418
 419 /*
 420  * __vb2_queue_free() - free buffers at the end of the queue - video memory and
 421  * related information, if no buffers are left return the queue to an
 422  * uninitialized state. Might be called even if the queue has already been freed.
 423  */
 424 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
 425 {
 426         unsigned int buffer;
 427
 428         /*
 429          * Sanity check: when preparing a buffer the queue lock is released for
 430          * a short while (see __buf_prepare for the details), which would allow
 431          * a race with a reqbufs which can call this function. Removing the
 432          * buffers from underneath __buf_prepare is obviously a bad idea, so we
 433          * check if any of the buffers is in the state PREPARING, and if so we
 434          * just return -EAGAIN.
 435          */
 436         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 437              ++buffer) {
 438                 if (q->bufs[buffer] == NULL)
 439                         continue;
 440                 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
 441                         dprintk(1, "preparing buffers, cannot free\n");
 442                         return -EAGAIN;
 443                 }
 444         }
 445
 446         /* Call driver-provided cleanup function for each buffer, if provided */
 447         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 448              ++buffer) {
 449                 struct vb2_buffer *vb = q->bufs[buffer];
 450
 451                 if (vb && vb->planes[0].mem_priv)
 452                         call_void_vb_qop(vb, buf_cleanup, vb);
 453         }
 454
 455         /* Release video buffer memory */
 456         __vb2_free_mem(q, buffers);
 457
 458 #ifdef CONFIG_VIDEO_ADV_DEBUG
 459         /*
 460          * Check that all the calls were balances during the life-time of this
 461          * queue. If not (or if the debug level is 1 or up), then dump the
 462          * counters to the kernel log.
 463          */
 464         if (q->num_buffers) {
 465                 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
 466                                   q->cnt_wait_prepare != q->cnt_wait_finish;
 467
 468                 if (unbalanced || debug) {
 469                         pr_info("counters for queue %p:%s\n", q,
 470                                 unbalanced ? " UNBALANCED!" : "");
 471                         pr_info("     setup: %u start_streaming: %u stop_streaming: %u\n",
 472                                 q->cnt_queue_setup, q->cnt_start_streaming,
 473                                 q->cnt_stop_streaming);
 474                         pr_info("     wait_prepare: %u wait_finish: %u\n",
 475                                 q->cnt_wait_prepare, q->cnt_wait_finish);
 476                 }
 477                 q->cnt_queue_setup = 0;
 478                 q->cnt_wait_prepare = 0;
 479                 q->cnt_wait_finish = 0;
 480                 q->cnt_start_streaming = 0;
 481                 q->cnt_stop_streaming = 0;
 482         }
 483         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 484                 struct vb2_buffer *vb = q->bufs[buffer];
 485                 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
 486                                   vb->cnt_mem_prepare != vb->cnt_mem_finish ||
 487                                   vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
 488                                   vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
 489                                   vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
 490                                   vb->cnt_buf_queue != vb->cnt_buf_done ||
 491                                   vb->cnt_buf_prepare != vb->cnt_buf_finish ||
 492                                   vb->cnt_buf_init != vb->cnt_buf_cleanup;
 493
 494                 if (unbalanced || debug) {
 495                         pr_info("   counters for queue %p, buffer %d:%s\n",
 496                                 q, buffer, unbalanced ? " UNBALANCED!" : "");
 497                         pr_info("     buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
 498                                 vb->cnt_buf_init, vb->cnt_buf_cleanup,
 499                                 vb->cnt_buf_prepare, vb->cnt_buf_finish);
 500                         pr_info("     buf_queue: %u buf_done: %u\n",
 501                                 vb->cnt_buf_queue, vb->cnt_buf_done);
 502                         pr_info("     alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
 503                                 vb->cnt_mem_alloc, vb->cnt_mem_put,
 504                                 vb->cnt_mem_prepare, vb->cnt_mem_finish,
 505                                 vb->cnt_mem_mmap);
 506                         pr_info("     get_userptr: %u put_userptr: %u\n",
 507                                 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
 508                         pr_info("     attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
 509                                 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
 510                                 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
 511                         pr_info("     get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
 512                                 vb->cnt_mem_get_dmabuf,
 513                                 vb->cnt_mem_num_users,
 514                                 vb->cnt_mem_vaddr,
 515                                 vb->cnt_mem_cookie);
 516                 }
 517         }
 518 #endif
 519
 520         /* Free videobuf buffers */
 521         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 522              ++buffer) {
 523                 kfree(q->bufs[buffer]);
 524                 q->bufs[buffer] = NULL;
 525         }
 526
 527         q->num_buffers -= buffers;
 528         if (!q->num_buffers) {
 529                 q->memory = VB2_MEMORY_UNKNOWN;
 530                 INIT_LIST_HEAD(&q->queued_list);
 531         }
 532         return 0;
 533 }
 534
 535 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
 536 {
 537         unsigned int plane;
 538         for (plane = 0; plane < vb->num_planes; ++plane) {
 539                 void *mem_priv = vb->planes[plane].mem_priv;
 540                 /*
 541                  * If num_users() has not been provided, call_memop
 542                  * will return 0, apparently nobody cares about this
 543                  * case anyway. If num_users() returns more than 1,
 544                  * we are not the only user of the plane's memory.
 545                  */
 546                 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
 547                         return true;
 548         }
 549         return false;
 550 }
 551 EXPORT_SYMBOL(vb2_buffer_in_use);
 552
 553 /*
 554  * __buffers_in_use() - return true if any buffers on the queue are in use and
 555  * the queue cannot be freed (by the means of REQBUFS(0)) call
 556  */
 557 static bool __buffers_in_use(struct vb2_queue *q)
 558 {
 559         unsigned int buffer;
 560         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 561                 if (vb2_buffer_in_use(q, q->bufs[buffer]))
 562                         return true;
 563         }
 564         return false;
 565 }
 566
 567 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
 568 {
 569         call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
 570 }
 571 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
 572
 573 /*
 574  * __verify_userptr_ops() - verify that all memory operations required for
 575  * USERPTR queue type have been provided
 576  */
 577 static int __verify_userptr_ops(struct vb2_queue *q)
 578 {
 579         if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
 580             !q->mem_ops->put_userptr)
 581                 return -EINVAL;
 582
 583         return 0;
 584 }
 585
 586 /*
 587  * __verify_mmap_ops() - verify that all memory operations required for
 588  * MMAP queue type have been provided
 589  */
 590 static int __verify_mmap_ops(struct vb2_queue *q)
 591 {
 592         if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
 593             !q->mem_ops->put || !q->mem_ops->mmap)
 594                 return -EINVAL;
 595
 596         return 0;
 597 }
 598
 599 /*
 600  * __verify_dmabuf_ops() - verify that all memory operations required for
 601  * DMABUF queue type have been provided
 602  */
 603 static int __verify_dmabuf_ops(struct vb2_queue *q)
 604 {
 605         if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
 606             !q->mem_ops->detach_dmabuf  || !q->mem_ops->map_dmabuf ||
 607             !q->mem_ops->unmap_dmabuf)
 608                 return -EINVAL;
 609
 610         return 0;
 611 }
 612
 613 int vb2_verify_memory_type(struct vb2_queue *q,
 614                 enum vb2_memory memory, unsigned int type)
 615 {
 616         if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
 617             memory != VB2_MEMORY_DMABUF) {
 618                 dprintk(1, "unsupported memory type\n");
 619                 return -EINVAL;
 620         }
 621
 622         if (type != q->type) {
 623                 dprintk(1, "requested type is incorrect\n");
 624                 return -EINVAL;
 625         }
 626
 627         /*
 628          * Make sure all the required memory ops for given memory type
 629          * are available.
 630          */
 631         if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
 632                 dprintk(1, "MMAP for current setup unsupported\n");
 633                 return -EINVAL;
 634         }
 635
 636         if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
 637                 dprintk(1, "USERPTR for current setup unsupported\n");
 638                 return -EINVAL;
 639         }
 640
 641         if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
 642                 dprintk(1, "DMABUF for current setup unsupported\n");
 643                 return -EINVAL;
 644         }
 645
 646         /*
 647          * Place the busy tests at the end: -EBUSY can be ignored when
 648          * create_bufs is called with count == 0, but count == 0 should still
 649          * do the memory and type validation.
 650          */
 651         if (vb2_fileio_is_active(q)) {
 652                 dprintk(1, "file io in progress\n");
 653                 return -EBUSY;
 654         }
 655         return 0;
 656 }
 657 EXPORT_SYMBOL(vb2_verify_memory_type);
 658
 659 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 660                 unsigned int *count)
 661 {
 662         unsigned int num_buffers, allocated_buffers, num_planes = 0;
 663         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 664         int ret;
 665
 666         if (q->streaming) {
 667                 dprintk(1, "streaming active\n");
 668                 return -EBUSY;
 669         }
 670
 671         if (*count == 0 || q->num_buffers != 0 ||
 672             (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory)) {
 673                 /*
 674                  * We already have buffers allocated, so first check if they
 675                  * are not in use and can be freed.
 676                  */
 677                 mutex_lock(&q->mmap_lock);
 678                 if (q->memory == VB2_MEMORY_MMAP && __buffers_in_use(q)) {
 679                         mutex_unlock(&q->mmap_lock);
 680                         dprintk(1, "memory in use, cannot free\n");
 681                         return -EBUSY;
 682                 }
 683
 684                 /*
 685                  * Call queue_cancel to clean up any buffers in the PREPARED or
 686                  * QUEUED state which is possible if buffers were prepared or
 687                  * queued without ever calling STREAMON.
 688                  */
 689                 __vb2_queue_cancel(q);
 690                 ret = __vb2_queue_free(q, q->num_buffers);
 691                 mutex_unlock(&q->mmap_lock);
 692                 if (ret)
 693                         return ret;
 694
 695                 /*
 696                  * In case of REQBUFS(0) return immediately without calling
 697                  * driver's queue_setup() callback and allocating resources.
 698                  */
 699                 if (*count == 0)
 700                         return 0;
 701         }
 702
 703         /*
 704          * Make sure the requested values and current defaults are sane.
 705          */
 706         WARN_ON(q->min_buffers_needed > VB2_MAX_FRAME);
 707         num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);
 708         num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);
 709         memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 710         q->memory = memory;
 711
 712         /*
 713          * Ask the driver how many buffers and planes per buffer it requires.
 714          * Driver also sets the size and allocator context for each plane.
 715          */
 716         ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
 717                        plane_sizes, q->alloc_devs);
 718         if (ret)
 719                 return ret;
 720
 721         /* Finally, allocate buffers and video memory */
 722         allocated_buffers =
 723                 __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
 724         if (allocated_buffers == 0) {
 725                 dprintk(1, "memory allocation failed\n");
 726                 return -ENOMEM;
 727         }
 728
 729         /*
 730          * There is no point in continuing if we can't allocate the minimum
 731          * number of buffers needed by this vb2_queue.
 732          */
 733         if (allocated_buffers < q->min_buffers_needed)
 734                 ret = -ENOMEM;
 735
 736         /*
 737          * Check if driver can handle the allocated number of buffers.
 738          */
 739         if (!ret && allocated_buffers < num_buffers) {
 740                 num_buffers = allocated_buffers;
 741                 /*
 742                  * num_planes is set by the previous queue_setup(), but since it
 743                  * signals to queue_setup() whether it is called from create_bufs()
 744                  * vs reqbufs() we zero it here to signal that queue_setup() is
 745                  * called for the reqbufs() case.
 746                  */
 747                 num_planes = 0;
 748
 749                 ret = call_qop(q, queue_setup, q, &num_buffers,
 750                                &num_planes, plane_sizes, q->alloc_devs);
 751
 752                 if (!ret && allocated_buffers < num_buffers)
 753                         ret = -ENOMEM;
 754
 755                 /*
 756                  * Either the driver has accepted a smaller number of buffers,
 757                  * or .queue_setup() returned an error
 758                  */
 759         }
 760
 761         mutex_lock(&q->mmap_lock);
 762         q->num_buffers = allocated_buffers;
 763
 764         if (ret < 0) {
 765                 /*
 766                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 767                  * from q->num_buffers.
 768                  */
 769                 __vb2_queue_free(q, allocated_buffers);
 770                 mutex_unlock(&q->mmap_lock);
 771                 return ret;
 772         }
 773         mutex_unlock(&q->mmap_lock);
 774
 775         /*
 776          * Return the number of successfully allocated buffers
 777          * to the userspace.
 778          */
 779         *count = allocated_buffers;
 780         q->waiting_for_buffers = !q->is_output;
 781
 782         return 0;
 783 }
 784 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
 785
 786 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 787                 unsigned int *count, unsigned requested_planes,
 788                 const unsigned requested_sizes[])
 789 {
 790         unsigned int num_planes = 0, num_buffers, allocated_buffers;
 791         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 792         int ret;
 793
 794         if (q->num_buffers == VB2_MAX_FRAME) {
 795                 dprintk(1, "maximum number of buffers already allocated\n");
 796                 return -ENOBUFS;
 797         }
 798
 799         if (!q->num_buffers) {
 800                 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 801                 q->memory = memory;
 802                 q->waiting_for_buffers = !q->is_output;
 803         }
 804
 805         num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
 806
 807         if (requested_planes && requested_sizes) {
 808                 num_planes = requested_planes;
 809                 memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
 810         }
 811
 812         /*
 813          * Ask the driver, whether the requested number of buffers, planes per
 814          * buffer and their sizes are acceptable
 815          */
 816         ret = call_qop(q, queue_setup, q, &num_buffers,
 817                        &num_planes, plane_sizes, q->alloc_devs);
 818         if (ret)
 819                 return ret;
 820
 821         /* Finally, allocate buffers and video memory */
 822         allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
 823                                 num_planes, plane_sizes);
 824         if (allocated_buffers == 0) {
 825                 dprintk(1, "memory allocation failed\n");
 826                 return -ENOMEM;
 827         }
 828
 829         /*
 830          * Check if driver can handle the so far allocated number of buffers.
 831          */
 832         if (allocated_buffers < num_buffers) {
 833                 num_buffers = allocated_buffers;
 834
 835                 /*
 836                  * q->num_buffers contains the total number of buffers, that the
 837                  * queue driver has set up
 838                  */
 839                 ret = call_qop(q, queue_setup, q, &num_buffers,
 840                                &num_planes, plane_sizes, q->alloc_devs);
 841
 842                 if (!ret && allocated_buffers < num_buffers)
 843                         ret = -ENOMEM;
 844
 845                 /*
 846                  * Either the driver has accepted a smaller number of buffers,
 847                  * or .queue_setup() returned an error
 848                  */
 849         }
 850
 851         mutex_lock(&q->mmap_lock);
 852         q->num_buffers += allocated_buffers;
 853
 854         if (ret < 0) {
 855                 /*
 856                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 857                  * from q->num_buffers.
 858                  */
 859                 __vb2_queue_free(q, allocated_buffers);
 860                 mutex_unlock(&q->mmap_lock);
 861                 return -ENOMEM;
 862         }
 863         mutex_unlock(&q->mmap_lock);
 864
 865         /*
 866          * Return the number of successfully allocated buffers
 867          * to the userspace.
 868          */
 869         *count = allocated_buffers;
 870
 871         return 0;
 872 }
 873 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
 874
 875 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
 876 {
 877         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
 878                 return NULL;
 879
 880         return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
 881
 882 }
 883 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
 884
 885 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
 886 {
 887         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
 888                 return NULL;
 889
 890         return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
 891 }
 892 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
 893
 894 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
 895 {
 896         struct vb2_queue *q = vb->vb2_queue;
 897         unsigned long flags;
 898         unsigned int plane;
 899
 900         if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
 901                 return;
 902
 903         if (WARN_ON(state != VB2_BUF_STATE_DONE &&
 904                     state != VB2_BUF_STATE_ERROR &&
 905                     state != VB2_BUF_STATE_QUEUED &&
 906                     state != VB2_BUF_STATE_REQUEUEING))
 907                 state = VB2_BUF_STATE_ERROR;
 908
 909 #ifdef CONFIG_VIDEO_ADV_DEBUG
 910         /*
 911          * Although this is not a callback, it still does have to balance
 912          * with the buf_queue op. So update this counter manually.
 913          */
 914         vb->cnt_buf_done++;
 915 #endif
 916         dprintk(4, "done processing on buffer %d, state: %d\n",
 917                         vb->index, state);
 918
 919         /* sync buffers */
 920         for (plane = 0; plane < vb->num_planes; ++plane)
 921                 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
 922
 923         spin_lock_irqsave(&q->done_lock, flags);
 924         if (state == VB2_BUF_STATE_QUEUED ||
 925             state == VB2_BUF_STATE_REQUEUEING) {
 926                 vb->state = VB2_BUF_STATE_QUEUED;
 927         } else {
 928                 /* Add the buffer to the done buffers list */
 929                 list_add_tail(&vb->done_entry, &q->done_list);
 930                 vb->state = state;
 931         }
 932         atomic_dec(&q->owned_by_drv_count);
 933         spin_unlock_irqrestore(&q->done_lock, flags);
 934
 935         trace_vb2_buf_done(q, vb);
 936
 937         switch (state) {
 938         case VB2_BUF_STATE_QUEUED:
 939                 return;
 940         case VB2_BUF_STATE_REQUEUEING:
 941                 if (q->start_streaming_called)
 942                         __enqueue_in_driver(vb);
 943                 return;
 944         default:
 945                 /* Inform any processes that may be waiting for buffers */
 946                 wake_up(&q->done_wq);
 947                 break;
 948         }
 949 }
 950 EXPORT_SYMBOL_GPL(vb2_buffer_done);
 951
 952 void vb2_discard_done(struct vb2_queue *q)
 953 {
 954         struct vb2_buffer *vb;
 955         unsigned long flags;
 956
 957         spin_lock_irqsave(&q->done_lock, flags);
 958         list_for_each_entry(vb, &q->done_list, done_entry)
 959                 vb->state = VB2_BUF_STATE_ERROR;
 960         spin_unlock_irqrestore(&q->done_lock, flags);
 961 }
 962 EXPORT_SYMBOL_GPL(vb2_discard_done);
 963
 964 /*
 965  * __prepare_mmap() - prepare an MMAP buffer
 966  */
 967 static int __prepare_mmap(struct vb2_buffer *vb, const void *pb)
 968 {
 969         int ret = 0;
 970
 971         if (pb)
 972                 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
 973                                  vb, pb, vb->planes);
 974         return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
 975 }
 976
 977 /*
 978  * __prepare_userptr() - prepare a USERPTR buffer
 979  */
 980 static int __prepare_userptr(struct vb2_buffer *vb, const void *pb)
 981 {
 982         struct vb2_plane planes[VB2_MAX_PLANES];
 983         struct vb2_queue *q = vb->vb2_queue;
 984         void *mem_priv;
 985         unsigned int plane;
 986         int ret = 0;
 987         bool reacquired = vb->planes[0].mem_priv == NULL;
 988
 989         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
 990         /* Copy relevant information provided by the userspace */
 991         if (pb) {
 992                 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
 993                                  vb, pb, planes);
 994                 if (ret)
 995                         return ret;
 996         }
 997
 998         for (plane = 0; plane < vb->num_planes; ++plane) {
 999                 /* Skip the plane if already verified */
1000                 if (vb->planes[plane].m.userptr &&
1001                         vb->planes[plane].m.userptr == planes[plane].m.userptr
1002                         && vb->planes[plane].length == planes[plane].length)
1003                         continue;
1004
1005                 dprintk(3, "userspace address for plane %d changed, reacquiring memory\n",
1006                         plane);
1007
1008                 /* Check if the provided plane buffer is large enough */
1009                 if (planes[plane].length < vb->planes[plane].min_length) {
1010                         dprintk(1, "provided buffer size %u is less than setup size %u for plane %d\n",
1011                                                 planes[plane].length,
1012                                                 vb->planes[plane].min_length,
1013                                                 plane);
1014                         ret = -EINVAL;
1015                         goto err;
1016                 }
1017
1018                 /* Release previously acquired memory if present */
1019                 if (vb->planes[plane].mem_priv) {
1020                         if (!reacquired) {
1021                                 reacquired = true;
1022                                 call_void_vb_qop(vb, buf_cleanup, vb);
1023                         }
1024                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1025                 }
1026
1027                 vb->planes[plane].mem_priv = NULL;
1028                 vb->planes[plane].bytesused = 0;
1029                 vb->planes[plane].length = 0;
1030                 vb->planes[plane].m.userptr = 0;
1031                 vb->planes[plane].data_offset = 0;
1032
1033                 /* Acquire each plane's memory */
1034                 mem_priv = call_ptr_memop(vb, get_userptr,
1035                                 q->alloc_devs[plane] ? : q->dev,
1036                                 planes[plane].m.userptr,
1037                                 planes[plane].length, q->dma_dir);
1038                 if (IS_ERR(mem_priv)) {
1039                         dprintk(1, "failed acquiring userspace memory for plane %d\n",
1040                                 plane);
1041                         ret = PTR_ERR(mem_priv);
1042                         goto err;
1043                 }
1044                 vb->planes[plane].mem_priv = mem_priv;
1045         }
1046
1047         /*
1048          * Now that everything is in order, copy relevant information
1049          * provided by userspace.
1050          */
1051         for (plane = 0; plane < vb->num_planes; ++plane) {
1052                 vb->planes[plane].bytesused = planes[plane].bytesused;
1053                 vb->planes[plane].length = planes[plane].length;
1054                 vb->planes[plane].m.userptr = planes[plane].m.userptr;
1055                 vb->planes[plane].data_offset = planes[plane].data_offset;
1056         }
1057
1058         if (reacquired) {
1059                 /*
1060                  * One or more planes changed, so we must call buf_init to do
1061                  * the driver-specific initialization on the newly acquired
1062                  * buffer, if provided.
1063                  */
1064                 ret = call_vb_qop(vb, buf_init, vb);
1065                 if (ret) {
1066                         dprintk(1, "buffer initialization failed\n");
1067                         goto err;
1068                 }
1069         }
1070
1071         ret = call_vb_qop(vb, buf_prepare, vb);
1072         if (ret) {
1073                 dprintk(1, "buffer preparation failed\n");
1074                 call_void_vb_qop(vb, buf_cleanup, vb);
1075                 goto err;
1076         }
1077
1078         return 0;
1079 err:
1080         /* In case of errors, release planes that were already acquired */
1081         for (plane = 0; plane < vb->num_planes; ++plane) {
1082                 if (vb->planes[plane].mem_priv)
1083                         call_void_memop(vb, put_userptr,
1084                                 vb->planes[plane].mem_priv);
1085                 vb->planes[plane].mem_priv = NULL;
1086                 vb->planes[plane].m.userptr = 0;
1087                 vb->planes[plane].length = 0;
1088         }
1089
1090         return ret;
1091 }
1092
1093 /*
1094  * __prepare_dmabuf() - prepare a DMABUF buffer
1095  */
1096 static int __prepare_dmabuf(struct vb2_buffer *vb, const void *pb)
1097 {
1098         struct vb2_plane planes[VB2_MAX_PLANES];
1099         struct vb2_queue *q = vb->vb2_queue;
1100         void *mem_priv;
1101         unsigned int plane;
1102         int ret = 0;
1103         bool reacquired = vb->planes[0].mem_priv == NULL;
1104
1105         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1106         /* Copy relevant information provided by the userspace */
1107         if (pb) {
1108                 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1109                                  vb, pb, planes);
1110                 if (ret)
1111                         return ret;
1112         }
1113
1114         for (plane = 0; plane < vb->num_planes; ++plane) {
1115                 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1116
1117                 if (IS_ERR_OR_NULL(dbuf)) {
1118                         dprintk(1, "invalid dmabuf fd for plane %d\n",
1119                                 plane);
1120                         ret = -EINVAL;
1121                         goto err;
1122                 }
1123
1124                 /* use DMABUF size if length is not provided */
1125                 if (planes[plane].length == 0)
1126                         planes[plane].length = dbuf->size;
1127
1128                 if (planes[plane].length < vb->planes[plane].min_length) {
1129                         dprintk(1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
1130                                 planes[plane].length, plane,
1131                                 vb->planes[plane].min_length);
1132                         dma_buf_put(dbuf);
1133                         ret = -EINVAL;
1134                         goto err;
1135                 }
1136
1137                 /* Skip the plane if already verified */
1138                 if (dbuf == vb->planes[plane].dbuf &&
1139                         vb->planes[plane].length == planes[plane].length) {
1140                         dma_buf_put(dbuf);
1141                         continue;
1142                 }
1143
1144                 dprintk(3, "buffer for plane %d changed\n", plane);
1145
1146                 if (!reacquired) {
1147                         reacquired = true;
1148                         call_void_vb_qop(vb, buf_cleanup, vb);
1149                 }
1150
1151                 /* Release previously acquired memory if present */
1152                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1153                 vb->planes[plane].bytesused = 0;
1154                 vb->planes[plane].length = 0;
1155                 vb->planes[plane].m.fd = 0;
1156                 vb->planes[plane].data_offset = 0;
1157
1158                 /* Acquire each plane's memory */
1159                 mem_priv = call_ptr_memop(vb, attach_dmabuf,
1160                                 q->alloc_devs[plane] ? : q->dev,
1161                                 dbuf, planes[plane].length, q->dma_dir);
1162                 if (IS_ERR(mem_priv)) {
1163                         dprintk(1, "failed to attach dmabuf\n");
1164                         ret = PTR_ERR(mem_priv);
1165                         dma_buf_put(dbuf);
1166                         goto err;
1167                 }
1168
1169                 vb->planes[plane].dbuf = dbuf;
1170                 vb->planes[plane].mem_priv = mem_priv;
1171         }
1172
1173         /*
1174          * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1175          * here instead just before the DMA, while queueing the buffer(s) so
1176          * userspace knows sooner rather than later if the dma-buf map fails.
1177          */
1178         for (plane = 0; plane < vb->num_planes; ++plane) {
1179                 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1180                 if (ret) {
1181                         dprintk(1, "failed to map dmabuf for plane %d\n",
1182                                 plane);
1183                         goto err;
1184                 }
1185                 vb->planes[plane].dbuf_mapped = 1;
1186         }
1187
1188         /*
1189          * Now that everything is in order, copy relevant information
1190          * provided by userspace.
1191          */
1192         for (plane = 0; plane < vb->num_planes; ++plane) {
1193                 vb->planes[plane].bytesused = planes[plane].bytesused;
1194                 vb->planes[plane].length = planes[plane].length;
1195                 vb->planes[plane].m.fd = planes[plane].m.fd;
1196                 vb->planes[plane].data_offset = planes[plane].data_offset;
1197         }
1198
1199         if (reacquired) {
1200                 /*
1201                  * Call driver-specific initialization on the newly acquired buffer,
1202                  * if provided.
1203                  */
1204                 ret = call_vb_qop(vb, buf_init, vb);
1205                 if (ret) {
1206                         dprintk(1, "buffer initialization failed\n");
1207                         goto err;
1208                 }
1209         }
1210
1211         ret = call_vb_qop(vb, buf_prepare, vb);
1212         if (ret) {
1213                 dprintk(1, "buffer preparation failed\n");
1214                 call_void_vb_qop(vb, buf_cleanup, vb);
1215                 goto err;
1216         }
1217
1218         return 0;
1219 err:
1220         /* In case of errors, release planes that were already acquired */
1221         __vb2_buf_dmabuf_put(vb);
1222
1223         return ret;
1224 }
1225
1226 /*
1227  * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1228  */
1229 static void __enqueue_in_driver(struct vb2_buffer *vb)
1230 {
1231         struct vb2_queue *q = vb->vb2_queue;
1232
1233         vb->state = VB2_BUF_STATE_ACTIVE;
1234         atomic_inc(&q->owned_by_drv_count);
1235
1236         trace_vb2_buf_queue(q, vb);
1237
1238         call_void_vb_qop(vb, buf_queue, vb);
1239 }
1240
1241 static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
1242 {
1243         struct vb2_queue *q = vb->vb2_queue;
1244         unsigned int plane;
1245         int ret;
1246
1247         if (q->error) {
1248                 dprintk(1, "fatal error occurred on queue\n");
1249                 return -EIO;
1250         }
1251
1252         vb->state = VB2_BUF_STATE_PREPARING;
1253
1254         switch (q->memory) {
1255         case VB2_MEMORY_MMAP:
1256                 ret = __prepare_mmap(vb, pb);
1257                 break;
1258         case VB2_MEMORY_USERPTR:
1259                 ret = __prepare_userptr(vb, pb);
1260                 break;
1261         case VB2_MEMORY_DMABUF:
1262                 ret = __prepare_dmabuf(vb, pb);
1263                 break;
1264         default:
1265                 WARN(1, "Invalid queue type\n");
1266                 ret = -EINVAL;
1267         }
1268
1269         if (ret) {
1270                 dprintk(1, "buffer preparation failed: %d\n", ret);
1271                 vb->state = VB2_BUF_STATE_DEQUEUED;
1272                 return ret;
1273         }
1274
1275         /* sync buffers */
1276         for (plane = 0; plane < vb->num_planes; ++plane)
1277                 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1278
1279         vb->state = VB2_BUF_STATE_PREPARED;
1280
1281         return 0;
1282 }
1283
1284 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1285 {
1286         struct vb2_buffer *vb;
1287         int ret;
1288
1289         vb = q->bufs[index];
1290         if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1291                 dprintk(1, "invalid buffer state %d\n",
1292                         vb->state);
1293                 return -EINVAL;
1294         }
1295
1296         ret = __buf_prepare(vb, pb);
1297         if (ret)
1298                 return ret;
1299
1300         /* Fill buffer information for the userspace */
1301         call_void_bufop(q, fill_user_buffer, vb, pb);
1302
1303         dprintk(2, "prepare of buffer %d succeeded\n", vb->index);
1304
1305         return ret;
1306 }
1307 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1308
1309 /*
1310  * vb2_start_streaming() - Attempt to start streaming.
1311  * @q:          videobuf2 queue
1312  *
1313  * Attempt to start streaming. When this function is called there must be
1314  * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1315  * number of buffers required for the DMA engine to function). If the
1316  * @start_streaming op fails it is supposed to return all the driver-owned
1317  * buffers back to vb2 in state QUEUED. Check if that happened and if
1318  * not warn and reclaim them forcefully.
1319  */
1320 static int vb2_start_streaming(struct vb2_queue *q)
1321 {
1322         struct vb2_buffer *vb;
1323         int ret;
1324
1325         /*
1326          * If any buffers were queued before streamon,
1327          * we can now pass them to driver for processing.
1328          */
1329         list_for_each_entry(vb, &q->queued_list, queued_entry)
1330                 __enqueue_in_driver(vb);
1331
1332         /* Tell the driver to start streaming */
1333         q->start_streaming_called = 1;
1334         ret = call_qop(q, start_streaming, q,
1335                        atomic_read(&q->owned_by_drv_count));
1336         if (!ret)
1337                 return 0;
1338
1339         q->start_streaming_called = 0;
1340
1341         dprintk(1, "driver refused to start streaming\n");
1342         /*
1343          * If you see this warning, then the driver isn't cleaning up properly
1344          * after a failed start_streaming(). See the start_streaming()
1345          * documentation in videobuf2-core.h for more information how buffers
1346          * should be returned to vb2 in start_streaming().
1347          */
1348         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1349                 unsigned i;
1350
1351                 /*
1352                  * Forcefully reclaim buffers if the driver did not
1353                  * correctly return them to vb2.
1354                  */
1355                 for (i = 0; i < q->num_buffers; ++i) {
1356                         vb = q->bufs[i];
1357                         if (vb->state == VB2_BUF_STATE_ACTIVE)
1358                                 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1359                 }
1360                 /* Must be zero now */
1361                 WARN_ON(atomic_read(&q->owned_by_drv_count));
1362         }
1363         /*
1364          * If done_list is not empty, then start_streaming() didn't call
1365          * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1366          * STATE_DONE.
1367          */
1368         WARN_ON(!list_empty(&q->done_list));
1369         return ret;
1370 }
1371
1372 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
1373 {
1374         struct vb2_buffer *vb;
1375         int ret;
1376
1377         vb = q->bufs[index];
1378
1379         switch (vb->state) {
1380         case VB2_BUF_STATE_DEQUEUED:
1381                 ret = __buf_prepare(vb, pb);
1382                 if (ret)
1383                         return ret;
1384                 break;
1385         case VB2_BUF_STATE_PREPARED:
1386                 break;
1387         case VB2_BUF_STATE_PREPARING:
1388                 dprintk(1, "buffer still being prepared\n");
1389                 return -EINVAL;
1390         default:
1391                 dprintk(1, "invalid buffer state %d\n", vb->state);
1392                 return -EINVAL;
1393         }
1394
1395         /*
1396          * Add to the queued buffers list, a buffer will stay on it until
1397          * dequeued in dqbuf.
1398          */
1399         list_add_tail(&vb->queued_entry, &q->queued_list);
1400         q->queued_count++;
1401         q->waiting_for_buffers = false;
1402         vb->state = VB2_BUF_STATE_QUEUED;
1403
1404         if (pb)
1405                 call_void_bufop(q, copy_timestamp, vb, pb);
1406
1407         trace_vb2_qbuf(q, vb);
1408
1409         /*
1410          * If already streaming, give the buffer to driver for processing.
1411          * If not, the buffer will be given to driver on next streamon.
1412          */
1413         if (q->start_streaming_called)
1414                 __enqueue_in_driver(vb);
1415
1416         /* Fill buffer information for the userspace */
1417         if (pb)
1418                 call_void_bufop(q, fill_user_buffer, vb, pb);
1419
1420         /*
1421          * If streamon has been called, and we haven't yet called
1422          * start_streaming() since not enough buffers were queued, and
1423          * we now have reached the minimum number of queued buffers,
1424          * then we can finally call start_streaming().
1425          */
1426         if (q->streaming && !q->start_streaming_called &&
1427             q->queued_count >= q->min_buffers_needed) {
1428                 ret = vb2_start_streaming(q);
1429                 if (ret)
1430                         return ret;
1431         }
1432
1433         dprintk(2, "qbuf of buffer %d succeeded\n", vb->index);
1434         return 0;
1435 }
1436 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1437
1438 /*
1439  * __vb2_wait_for_done_vb() - wait for a buffer to become available
1440  * for dequeuing
1441  *
1442  * Will sleep if required for nonblocking == false.
1443  */
1444 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1445 {
1446         /*
1447          * All operations on vb_done_list are performed under done_lock
1448          * spinlock protection. However, buffers may be removed from
1449          * it and returned to userspace only while holding both driver's
1450          * lock and the done_lock spinlock. Thus we can be sure that as
1451          * long as we hold the driver's lock, the list will remain not
1452          * empty if list_empty() check succeeds.
1453          */
1454
1455         for (;;) {
1456                 int ret;
1457
1458                 if (!q->streaming) {
1459                         dprintk(1, "streaming off, will not wait for buffers\n");
1460                         return -EINVAL;
1461                 }
1462
1463                 if (q->error) {
1464                         dprintk(1, "Queue in error state, will not wait for buffers\n");
1465                         return -EIO;
1466                 }
1467
1468                 if (q->last_buffer_dequeued) {
1469                         dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1470                         return -EPIPE;
1471                 }
1472
1473                 if (!list_empty(&q->done_list)) {
1474                         /*
1475                          * Found a buffer that we were waiting for.
1476                          */
1477                         break;
1478                 }
1479
1480                 if (nonblocking) {
1481                         dprintk(3, "nonblocking and no buffers to dequeue, will not wait\n");
1482                         return -EAGAIN;
1483                 }
1484
1485                 /*
1486                  * We are streaming and blocking, wait for another buffer to
1487                  * become ready or for streamoff. Driver's lock is released to
1488                  * allow streamoff or qbuf to be called while waiting.
1489                  */
1490                 call_void_qop(q, wait_prepare, q);
1491
1492                 /*
1493                  * All locks have been released, it is safe to sleep now.
1494                  */
1495                 dprintk(3, "will sleep waiting for buffers\n");
1496                 ret = wait_event_interruptible(q->done_wq,
1497                                 !list_empty(&q->done_list) || !q->streaming ||
1498                                 q->error);
1499
1500                 /*
1501                  * We need to reevaluate both conditions again after reacquiring
1502                  * the locks or return an error if one occurred.
1503                  */
1504                 call_void_qop(q, wait_finish, q);
1505                 if (ret) {
1506                         dprintk(1, "sleep was interrupted\n");
1507                         return ret;
1508                 }
1509         }
1510         return 0;
1511 }
1512
1513 /*
1514  * __vb2_get_done_vb() - get a buffer ready for dequeuing
1515  *
1516  * Will sleep if required for nonblocking == false.
1517  */
1518 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1519                              void *pb, int nonblocking)
1520 {
1521         unsigned long flags;
1522         int ret = 0;
1523
1524         /*
1525          * Wait for at least one buffer to become available on the done_list.
1526          */
1527         ret = __vb2_wait_for_done_vb(q, nonblocking);
1528         if (ret)
1529                 return ret;
1530
1531         /*
1532          * Driver's lock has been held since we last verified that done_list
1533          * is not empty, so no need for another list_empty(done_list) check.
1534          */
1535         spin_lock_irqsave(&q->done_lock, flags);
1536         *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1537         /*
1538          * Only remove the buffer from done_list if all planes can be
1539          * handled. Some cases such as V4L2 file I/O and DVB have pb
1540          * == NULL; skip the check then as there's nothing to verify.
1541          */
1542         if (pb)
1543                 ret = call_bufop(q, verify_planes_array, *vb, pb);
1544         if (!ret)
1545                 list_del(&(*vb)->done_entry);
1546         spin_unlock_irqrestore(&q->done_lock, flags);
1547
1548         return ret;
1549 }
1550
1551 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1552 {
1553         if (!q->streaming) {
1554                 dprintk(1, "streaming off, will not wait for buffers\n");
1555                 return -EINVAL;
1556         }
1557
1558         if (q->start_streaming_called)
1559                 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1560         return 0;
1561 }
1562 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1563
1564 /*
1565  * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1566  */
1567 static void __vb2_dqbuf(struct vb2_buffer *vb)
1568 {
1569         struct vb2_queue *q = vb->vb2_queue;
1570         unsigned int i;
1571
1572         /* nothing to do if the buffer is already dequeued */
1573         if (vb->state == VB2_BUF_STATE_DEQUEUED)
1574                 return;
1575
1576         vb->state = VB2_BUF_STATE_DEQUEUED;
1577
1578         /* unmap DMABUF buffer */
1579         if (q->memory == VB2_MEMORY_DMABUF)
1580                 for (i = 0; i < vb->num_planes; ++i) {
1581                         if (!vb->planes[i].dbuf_mapped)
1582                                 continue;
1583                         call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
1584                         vb->planes[i].dbuf_mapped = 0;
1585                 }
1586 }
1587
1588 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1589                    bool nonblocking)
1590 {
1591         struct vb2_buffer *vb = NULL;
1592         int ret;
1593
1594         ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1595         if (ret < 0)
1596                 return ret;
1597
1598         switch (vb->state) {
1599         case VB2_BUF_STATE_DONE:
1600                 dprintk(3, "returning done buffer\n");
1601                 break;
1602         case VB2_BUF_STATE_ERROR:
1603                 dprintk(3, "returning done buffer with errors\n");
1604                 break;
1605         default:
1606                 dprintk(1, "invalid buffer state\n");
1607                 return -EINVAL;
1608         }
1609
1610         call_void_vb_qop(vb, buf_finish, vb);
1611
1612         if (pindex)
1613                 *pindex = vb->index;
1614
1615         /* Fill buffer information for the userspace */
1616         if (pb)
1617                 call_void_bufop(q, fill_user_buffer, vb, pb);
1618
1619         /* Remove from videobuf queue */
1620         list_del(&vb->queued_entry);
1621         q->queued_count--;
1622
1623         trace_vb2_dqbuf(q, vb);
1624
1625         /* go back to dequeued state */
1626         __vb2_dqbuf(vb);
1627
1628         dprintk(2, "dqbuf of buffer %d, with state %d\n",
1629                         vb->index, vb->state);
1630
1631         return 0;
1632
1633 }
1634 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
1635
1636 /*
1637  * __vb2_queue_cancel() - cancel and stop (pause) streaming
1638  *
1639  * Removes all queued buffers from driver's queue and all buffers queued by
1640  * userspace from videobuf's queue. Returns to state after reqbufs.
1641  */
1642 static void __vb2_queue_cancel(struct vb2_queue *q)
1643 {
1644         unsigned int i;
1645
1646         /*
1647          * Tell driver to stop all transactions and release all queued
1648          * buffers.
1649          */
1650         if (q->start_streaming_called)
1651                 call_void_qop(q, stop_streaming, q);
1652
1653         /*
1654          * If you see this warning, then the driver isn't cleaning up properly
1655          * in stop_streaming(). See the stop_streaming() documentation in
1656          * videobuf2-core.h for more information how buffers should be returned
1657          * to vb2 in stop_streaming().
1658          */
1659         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1660                 for (i = 0; i < q->num_buffers; ++i)
1661                         if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE) {
1662                                 pr_warn("driver bug: stop_streaming operation is leaving buf %p in active state\n",
1663                                         q->bufs[i]);
1664                                 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
1665                         }
1666                 /* Must be zero now */
1667                 WARN_ON(atomic_read(&q->owned_by_drv_count));
1668         }
1669
1670         q->streaming = 0;
1671         q->start_streaming_called = 0;
1672         q->queued_count = 0;
1673         q->error = 0;
1674
1675         /*
1676          * Remove all buffers from videobuf's list...
1677          */
1678         INIT_LIST_HEAD(&q->queued_list);
1679         /*
1680          * ...and done list; userspace will not receive any buffers it
1681          * has not already dequeued before initiating cancel.
1682          */
1683         INIT_LIST_HEAD(&q->done_list);
1684         atomic_set(&q->owned_by_drv_count, 0);
1685         wake_up_all(&q->done_wq);
1686
1687         /*
1688          * Reinitialize all buffers for next use.
1689          * Make sure to call buf_finish for any queued buffers. Normally
1690          * that's done in dqbuf, but that's not going to happen when we
1691          * cancel the whole queue. Note: this code belongs here, not in
1692          * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
1693          * call to __fill_user_buffer() after buf_finish(). That order can't
1694          * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
1695          */
1696         for (i = 0; i < q->num_buffers; ++i) {
1697                 struct vb2_buffer *vb = q->bufs[i];
1698
1699                 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1700                         vb->state = VB2_BUF_STATE_PREPARED;
1701                         call_void_vb_qop(vb, buf_finish, vb);
1702                 }
1703                 __vb2_dqbuf(vb);
1704         }
1705 }
1706
1707 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
1708 {
1709         int ret;
1710
1711         if (type != q->type) {
1712                 dprintk(1, "invalid stream type\n");
1713                 return -EINVAL;
1714         }
1715
1716         if (q->streaming) {
1717                 dprintk(3, "already streaming\n");
1718                 return 0;
1719         }
1720
1721         if (!q->num_buffers) {
1722                 dprintk(1, "no buffers have been allocated\n");
1723                 return -EINVAL;
1724         }
1725
1726         if (q->num_buffers < q->min_buffers_needed) {
1727                 dprintk(1, "need at least %u allocated buffers\n",
1728                                 q->min_buffers_needed);
1729                 return -EINVAL;
1730         }
1731
1732         /*
1733          * Tell driver to start streaming provided sufficient buffers
1734          * are available.
1735          */
1736         if (q->queued_count >= q->min_buffers_needed) {
1737                 ret = v4l_vb2q_enable_media_source(q);
1738                 if (ret)
1739                         return ret;
1740                 ret = vb2_start_streaming(q);
1741                 if (ret) {
1742                         __vb2_queue_cancel(q);
1743                         return ret;
1744                 }
1745         }
1746
1747         q->streaming = 1;
1748
1749         dprintk(3, "successful\n");
1750         return 0;
1751 }
1752 EXPORT_SYMBOL_GPL(vb2_core_streamon);
1753
1754 void vb2_queue_error(struct vb2_queue *q)
1755 {
1756         q->error = 1;
1757
1758         wake_up_all(&q->done_wq);
1759 }
1760 EXPORT_SYMBOL_GPL(vb2_queue_error);
1761
1762 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
1763 {
1764         if (type != q->type) {
1765                 dprintk(1, "invalid stream type\n");
1766                 return -EINVAL;
1767         }
1768
1769         /*
1770          * Cancel will pause streaming and remove all buffers from the driver
1771          * and videobuf, effectively returning control over them to userspace.
1772          *
1773          * Note that we do this even if q->streaming == 0: if you prepare or
1774          * queue buffers, and then call streamoff without ever having called
1775          * streamon, you would still expect those buffers to be returned to
1776          * their normal dequeued state.
1777          */
1778         __vb2_queue_cancel(q);
1779         q->waiting_for_buffers = !q->is_output;
1780         q->last_buffer_dequeued = false;
1781
1782         dprintk(3, "successful\n");
1783         return 0;
1784 }
1785 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
1786
1787 /*
1788  * __find_plane_by_offset() - find plane associated with the given offset off
1789  */
1790 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
1791                         unsigned int *_buffer, unsigned int *_plane)
1792 {
1793         struct vb2_buffer *vb;
1794         unsigned int buffer, plane;
1795
1796         /*
1797          * Go over all buffers and their planes, comparing the given offset
1798          * with an offset assigned to each plane. If a match is found,
1799          * return its buffer and plane numbers.
1800          */
1801         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
1802                 vb = q->bufs[buffer];
1803
1804                 for (plane = 0; plane < vb->num_planes; ++plane) {
1805                         if (vb->planes[plane].m.offset == off) {
1806                                 *_buffer = buffer;
1807                                 *_plane = plane;
1808                                 return 0;
1809                         }
1810                 }
1811         }
1812
1813         return -EINVAL;
1814 }
1815
1816 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
1817                 unsigned int index, unsigned int plane, unsigned int flags)
1818 {
1819         struct vb2_buffer *vb = NULL;
1820         struct vb2_plane *vb_plane;
1821         int ret;
1822         struct dma_buf *dbuf;
1823
1824         if (q->memory != VB2_MEMORY_MMAP) {
1825                 dprintk(1, "queue is not currently set up for mmap\n");
1826                 return -EINVAL;
1827         }
1828
1829         if (!q->mem_ops->get_dmabuf) {
1830                 dprintk(1, "queue does not support DMA buffer exporting\n");
1831                 return -EINVAL;
1832         }
1833
1834         if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
1835                 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
1836                 return -EINVAL;
1837         }
1838
1839         if (type != q->type) {
1840                 dprintk(1, "invalid buffer type\n");
1841                 return -EINVAL;
1842         }
1843
1844         if (index >= q->num_buffers) {
1845                 dprintk(1, "buffer index out of range\n");
1846                 return -EINVAL;
1847         }
1848
1849         vb = q->bufs[index];
1850
1851         if (plane >= vb->num_planes) {
1852                 dprintk(1, "buffer plane out of range\n");
1853                 return -EINVAL;
1854         }
1855
1856         if (vb2_fileio_is_active(q)) {
1857                 dprintk(1, "expbuf: file io in progress\n");
1858                 return -EBUSY;
1859         }
1860
1861         vb_plane = &vb->planes[plane];
1862
1863         dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv,
1864                                 flags & O_ACCMODE);
1865         if (IS_ERR_OR_NULL(dbuf)) {
1866                 dprintk(1, "failed to export buffer %d, plane %d\n",
1867                         index, plane);
1868                 return -EINVAL;
1869         }
1870
1871         ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
1872         if (ret < 0) {
1873                 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
1874                         index, plane, ret);
1875                 dma_buf_put(dbuf);
1876                 return ret;
1877         }
1878
1879         dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
1880                 index, plane, ret);
1881         *fd = ret;
1882
1883         return 0;
1884 }
1885 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
1886
1887 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
1888 {
1889         unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
1890         struct vb2_buffer *vb;
1891         unsigned int buffer = 0, plane = 0;
1892         int ret;
1893         unsigned long length;
1894
1895         if (q->memory != VB2_MEMORY_MMAP) {
1896                 dprintk(1, "queue is not currently set up for mmap\n");
1897                 return -EINVAL;
1898         }
1899
1900         /*
1901          * Check memory area access mode.
1902          */
1903         if (!(vma->vm_flags & VM_SHARED)) {
1904                 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
1905                 return -EINVAL;
1906         }
1907         if (q->is_output) {
1908                 if (!(vma->vm_flags & VM_WRITE)) {
1909                         dprintk(1, "invalid vma flags, VM_WRITE needed\n");
1910                         return -EINVAL;
1911                 }
1912         } else {
1913                 if (!(vma->vm_flags & VM_READ)) {
1914                         dprintk(1, "invalid vma flags, VM_READ needed\n");
1915                         return -EINVAL;
1916                 }
1917         }
1918         if (vb2_fileio_is_active(q)) {
1919                 dprintk(1, "mmap: file io in progress\n");
1920                 return -EBUSY;
1921         }
1922
1923         /*
1924          * Find the plane corresponding to the offset passed by userspace.
1925          */
1926         ret = __find_plane_by_offset(q, off, &buffer, &plane);
1927         if (ret)
1928                 return ret;
1929
1930         vb = q->bufs[buffer];
1931
1932         /*
1933          * MMAP requires page_aligned buffers.
1934          * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
1935          * so, we need to do the same here.
1936          */
1937         length = PAGE_ALIGN(vb->planes[plane].length);
1938         if (length < (vma->vm_end - vma->vm_start)) {
1939                 dprintk(1,
1940                         "MMAP invalid, as it would overflow buffer length\n");
1941                 return -EINVAL;
1942         }
1943
1944         mutex_lock(&q->mmap_lock);
1945         ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
1946         mutex_unlock(&q->mmap_lock);
1947         if (ret)
1948                 return ret;
1949
1950         dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
1951         return 0;
1952 }
1953 EXPORT_SYMBOL_GPL(vb2_mmap);
1954
1955 #ifndef CONFIG_MMU
1956 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
1957                                     unsigned long addr,
1958                                     unsigned long len,
1959                                     unsigned long pgoff,
1960                                     unsigned long flags)
1961 {
1962         unsigned long off = pgoff << PAGE_SHIFT;
1963         struct vb2_buffer *vb;
1964         unsigned int buffer, plane;
1965         void *vaddr;
1966         int ret;
1967
1968         if (q->memory != VB2_MEMORY_MMAP) {
1969                 dprintk(1, "queue is not currently set up for mmap\n");
1970                 return -EINVAL;
1971         }
1972
1973         /*
1974          * Find the plane corresponding to the offset passed by userspace.
1975          */
1976         ret = __find_plane_by_offset(q, off, &buffer, &plane);
1977         if (ret)
1978                 return ret;
1979
1980         vb = q->bufs[buffer];
1981
1982         vaddr = vb2_plane_vaddr(vb, plane);
1983         return vaddr ? (unsigned long)vaddr : -EINVAL;
1984 }
1985 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
1986 #endif
1987
1988 int vb2_core_queue_init(struct vb2_queue *q)
1989 {
1990         /*
1991          * Sanity check
1992          */
1993         if (WARN_ON(!q)                   ||
1994             WARN_ON(!q->ops)              ||
1995             WARN_ON(!q->mem_ops)          ||
1996             WARN_ON(!q->type)             ||
1997             WARN_ON(!q->io_modes)         ||
1998             WARN_ON(!q->ops->queue_setup) ||
1999             WARN_ON(!q->ops->buf_queue))
2000                 return -EINVAL;
2001
2002         INIT_LIST_HEAD(&q->queued_list);
2003         INIT_LIST_HEAD(&q->done_list);
2004         spin_lock_init(&q->done_lock);
2005         mutex_init(&q->mmap_lock);
2006         init_waitqueue_head(&q->done_wq);
2007
2008         q->memory = VB2_MEMORY_UNKNOWN;
2009
2010         if (q->buf_struct_size == 0)
2011                 q->buf_struct_size = sizeof(struct vb2_buffer);
2012
2013         if (q->bidirectional)
2014                 q->dma_dir = DMA_BIDIRECTIONAL;
2015         else
2016                 q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
2017
2018         return 0;
2019 }
2020 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2021
2022 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2023 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2024 void vb2_core_queue_release(struct vb2_queue *q)
2025 {
2026         __vb2_cleanup_fileio(q);
2027         __vb2_queue_cancel(q);
2028         mutex_lock(&q->mmap_lock);
2029         __vb2_queue_free(q, q->num_buffers);
2030         mutex_unlock(&q->mmap_lock);
2031 }
2032 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2033
2034 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
2035                 poll_table *wait)
2036 {
2037         __poll_t req_events = poll_requested_events(wait);
2038         struct vb2_buffer *vb = NULL;
2039         unsigned long flags;
2040
2041         if (!q->is_output && !(req_events & (POLLIN | POLLRDNORM)))
2042                 return 0;
2043         if (q->is_output && !(req_events & (POLLOUT | POLLWRNORM)))
2044                 return 0;
2045
2046         /*
2047          * Start file I/O emulator only if streaming API has not been used yet.
2048          */
2049         if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2050                 if (!q->is_output && (q->io_modes & VB2_READ) &&
2051                                 (req_events & (POLLIN | POLLRDNORM))) {
2052                         if (__vb2_init_fileio(q, 1))
2053                                 return POLLERR;
2054                 }
2055                 if (q->is_output && (q->io_modes & VB2_WRITE) &&
2056                                 (req_events & (POLLOUT | POLLWRNORM))) {
2057                         if (__vb2_init_fileio(q, 0))
2058                                 return POLLERR;
2059                         /*
2060                          * Write to OUTPUT queue can be done immediately.
2061                          */
2062                         return POLLOUT | POLLWRNORM;
2063                 }
2064         }
2065
2066         /*
2067          * There is nothing to wait for if the queue isn't streaming, or if the
2068          * error flag is set.
2069          */
2070         if (!vb2_is_streaming(q) || q->error)
2071                 return POLLERR;
2072
2073         /*
2074          * If this quirk is set and QBUF hasn't been called yet then
2075          * return POLLERR as well. This only affects capture queues, output
2076          * queues will always initialize waiting_for_buffers to false.
2077          * This quirk is set by V4L2 for backwards compatibility reasons.
2078          */
2079         if (q->quirk_poll_must_check_waiting_for_buffers &&
2080             q->waiting_for_buffers && (req_events & (POLLIN | POLLRDNORM)))
2081                 return POLLERR;
2082
2083         /*
2084          * For output streams you can call write() as long as there are fewer
2085          * buffers queued than there are buffers available.
2086          */
2087         if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2088                 return POLLOUT | POLLWRNORM;
2089
2090         if (list_empty(&q->done_list)) {
2091                 /*
2092                  * If the last buffer was dequeued from a capture queue,
2093                  * return immediately. DQBUF will return -EPIPE.
2094                  */
2095                 if (q->last_buffer_dequeued)
2096                         return POLLIN | POLLRDNORM;
2097
2098                 poll_wait(file, &q->done_wq, wait);
2099         }
2100
2101         /*
2102          * Take first buffer available for dequeuing.
2103          */
2104         spin_lock_irqsave(&q->done_lock, flags);
2105         if (!list_empty(&q->done_list))
2106                 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2107                                         done_entry);
2108         spin_unlock_irqrestore(&q->done_lock, flags);
2109
2110         if (vb && (vb->state == VB2_BUF_STATE_DONE
2111                         || vb->state == VB2_BUF_STATE_ERROR)) {
2112                 return (q->is_output) ?
2113                                 POLLOUT | POLLWRNORM :
2114                                 POLLIN | POLLRDNORM;
2115         }
2116         return 0;
2117 }
2118 EXPORT_SYMBOL_GPL(vb2_core_poll);
2119
2120 /*
2121  * struct vb2_fileio_buf - buffer context used by file io emulator
2122  *
2123  * vb2 provides a compatibility layer and emulator of file io (read and
2124  * write) calls on top of streaming API. This structure is used for
2125  * tracking context related to the buffers.
2126  */
2127 struct vb2_fileio_buf {
2128         void *vaddr;
2129         unsigned int size;
2130         unsigned int pos;
2131         unsigned int queued:1;
2132 };
2133
2134 /*
2135  * struct vb2_fileio_data - queue context used by file io emulator
2136  *
2137  * @cur_index:  the index of the buffer currently being read from or
2138  *              written to. If equal to q->num_buffers then a new buffer
2139  *              must be dequeued.
2140  * @initial_index: in the read() case all buffers are queued up immediately
2141  *              in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2142  *              buffers. However, in the write() case no buffers are initially
2143  *              queued, instead whenever a buffer is full it is queued up by
2144  *              __vb2_perform_fileio(). Only once all available buffers have
2145  *              been queued up will __vb2_perform_fileio() start to dequeue
2146  *              buffers. This means that initially __vb2_perform_fileio()
2147  *              needs to know what buffer index to use when it is queuing up
2148  *              the buffers for the first time. That initial index is stored
2149  *              in this field. Once it is equal to q->num_buffers all
2150  *              available buffers have been queued and __vb2_perform_fileio()
2151  *              should start the normal dequeue/queue cycle.
2152  *
2153  * vb2 provides a compatibility layer and emulator of file io (read and
2154  * write) calls on top of streaming API. For proper operation it required
2155  * this structure to save the driver state between each call of the read
2156  * or write function.
2157  */
2158 struct vb2_fileio_data {
2159         unsigned int count;
2160         unsigned int type;
2161         unsigned int memory;
2162         struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2163         unsigned int cur_index;
2164         unsigned int initial_index;
2165         unsigned int q_count;
2166         unsigned int dq_count;
2167         unsigned read_once:1;
2168         unsigned write_immediately:1;
2169 };
2170
2171 /*
2172  * __vb2_init_fileio() - initialize file io emulator
2173  * @q:          videobuf2 queue
2174  * @read:       mode selector (1 means read, 0 means write)
2175  */
2176 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2177 {
2178         struct vb2_fileio_data *fileio;
2179         int i, ret;
2180         unsigned int count = 0;
2181
2182         /*
2183          * Sanity check
2184          */
2185         if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2186                     (!read && !(q->io_modes & VB2_WRITE))))
2187                 return -EINVAL;
2188
2189         /*
2190          * Check if device supports mapping buffers to kernel virtual space.
2191          */
2192         if (!q->mem_ops->vaddr)
2193                 return -EBUSY;
2194
2195         /*
2196          * Check if streaming api has not been already activated.
2197          */
2198         if (q->streaming || q->num_buffers > 0)
2199                 return -EBUSY;
2200
2201         /*
2202          * Start with count 1, driver can increase it in queue_setup()
2203          */
2204         count = 1;
2205
2206         dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2207                 (read) ? "read" : "write", count, q->fileio_read_once,
2208                 q->fileio_write_immediately);
2209
2210         fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2211         if (fileio == NULL)
2212                 return -ENOMEM;
2213
2214         fileio->read_once = q->fileio_read_once;
2215         fileio->write_immediately = q->fileio_write_immediately;
2216
2217         /*
2218          * Request buffers and use MMAP type to force driver
2219          * to allocate buffers by itself.
2220          */
2221         fileio->count = count;
2222         fileio->memory = VB2_MEMORY_MMAP;
2223         fileio->type = q->type;
2224         q->fileio = fileio;
2225         ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2226         if (ret)
2227                 goto err_kfree;
2228
2229         /*
2230          * Check if plane_count is correct
2231          * (multiplane buffers are not supported).
2232          */
2233         if (q->bufs[0]->num_planes != 1) {
2234                 ret = -EBUSY;
2235                 goto err_reqbufs;
2236         }
2237
2238         /*
2239          * Get kernel address of each buffer.
2240          */
2241         for (i = 0; i < q->num_buffers; i++) {
2242                 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2243                 if (fileio->bufs[i].vaddr == NULL) {
2244                         ret = -EINVAL;
2245                         goto err_reqbufs;
2246                 }
2247                 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2248         }
2249
2250         /*
2251          * Read mode requires pre queuing of all buffers.
2252          */
2253         if (read) {
2254                 /*
2255                  * Queue all buffers.
2256                  */
2257                 for (i = 0; i < q->num_buffers; i++) {
2258                         ret = vb2_core_qbuf(q, i, NULL);
2259                         if (ret)
2260                                 goto err_reqbufs;
2261                         fileio->bufs[i].queued = 1;
2262                 }
2263                 /*
2264                  * All buffers have been queued, so mark that by setting
2265                  * initial_index to q->num_buffers
2266                  */
2267                 fileio->initial_index = q->num_buffers;
2268                 fileio->cur_index = q->num_buffers;
2269         }
2270
2271         /*
2272          * Start streaming.
2273          */
2274         ret = vb2_core_streamon(q, q->type);
2275         if (ret)
2276                 goto err_reqbufs;
2277
2278         return ret;
2279
2280 err_reqbufs:
2281         fileio->count = 0;
2282         vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2283
2284 err_kfree:
2285         q->fileio = NULL;
2286         kfree(fileio);
2287         return ret;
2288 }
2289
2290 /*
2291  * __vb2_cleanup_fileio() - free resourced used by file io emulator
2292  * @q:          videobuf2 queue
2293  */
2294 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2295 {
2296         struct vb2_fileio_data *fileio = q->fileio;
2297
2298         if (fileio) {
2299                 vb2_core_streamoff(q, q->type);
2300                 q->fileio = NULL;
2301                 fileio->count = 0;
2302                 vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2303                 kfree(fileio);
2304                 dprintk(3, "file io emulator closed\n");
2305         }
2306         return 0;
2307 }
2308
2309 /*
2310  * __vb2_perform_fileio() - perform a single file io (read or write) operation
2311  * @q:          videobuf2 queue
2312  * @data:       pointed to target userspace buffer
2313  * @count:      number of bytes to read or write
2314  * @ppos:       file handle position tracking pointer
2315  * @nonblock:   mode selector (1 means blocking calls, 0 means nonblocking)
2316  * @read:       access mode selector (1 means read, 0 means write)
2317  */
2318 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2319                 loff_t *ppos, int nonblock, int read)
2320 {
2321         struct vb2_fileio_data *fileio;
2322         struct vb2_fileio_buf *buf;
2323         bool is_multiplanar = q->is_multiplanar;
2324         /*
2325          * When using write() to write data to an output video node the vb2 core
2326          * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2327          * else is able to provide this information with the write() operation.
2328          */
2329         bool copy_timestamp = !read && q->copy_timestamp;
2330         unsigned index;
2331         int ret;
2332
2333         dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2334                 read ? "read" : "write", (long)*ppos, count,
2335                 nonblock ? "non" : "");
2336
2337         if (!data)
2338                 return -EINVAL;
2339
2340         /*
2341          * Initialize emulator on first call.
2342          */
2343         if (!vb2_fileio_is_active(q)) {
2344                 ret = __vb2_init_fileio(q, read);
2345                 dprintk(3, "vb2_init_fileio result: %d\n", ret);
2346                 if (ret)
2347                         return ret;
2348         }
2349         fileio = q->fileio;
2350
2351         /*
2352          * Check if we need to dequeue the buffer.
2353          */
2354         index = fileio->cur_index;
2355         if (index >= q->num_buffers) {
2356                 struct vb2_buffer *b;
2357
2358                 /*
2359                  * Call vb2_dqbuf to get buffer back.
2360                  */
2361                 ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2362                 dprintk(5, "vb2_dqbuf result: %d\n", ret);
2363                 if (ret)
2364                         return ret;
2365                 fileio->dq_count += 1;
2366
2367                 fileio->cur_index = index;
2368                 buf = &fileio->bufs[index];
2369                 b = q->bufs[index];
2370
2371                 /*
2372                  * Get number of bytes filled by the driver
2373                  */
2374                 buf->pos = 0;
2375                 buf->queued = 0;
2376                 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2377                                  : vb2_plane_size(q->bufs[index], 0);
2378                 /* Compensate for data_offset on read in the multiplanar case. */
2379                 if (is_multiplanar && read &&
2380                                 b->planes[0].data_offset < buf->size) {
2381                         buf->pos = b->planes[0].data_offset;
2382                         buf->size -= buf->pos;
2383                 }
2384         } else {
2385                 buf = &fileio->bufs[index];
2386         }
2387
2388         /*
2389          * Limit count on last few bytes of the buffer.
2390          */
2391         if (buf->pos + count > buf->size) {
2392                 count = buf->size - buf->pos;
2393                 dprintk(5, "reducing read count: %zd\n", count);
2394         }
2395
2396         /*
2397          * Transfer data to userspace.
2398          */
2399         dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
2400                 count, index, buf->pos);
2401         if (read)
2402                 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2403         else
2404                 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2405         if (ret) {
2406                 dprintk(3, "error copying data\n");
2407                 return -EFAULT;
2408         }
2409
2410         /*
2411          * Update counters.
2412          */
2413         buf->pos += count;
2414         *ppos += count;
2415
2416         /*
2417          * Queue next buffer if required.
2418          */
2419         if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2420                 struct vb2_buffer *b = q->bufs[index];
2421
2422                 /*
2423                  * Check if this is the last buffer to read.
2424                  */
2425                 if (read && fileio->read_once && fileio->dq_count == 1) {
2426                         dprintk(3, "read limit reached\n");
2427                         return __vb2_cleanup_fileio(q);
2428                 }
2429
2430                 /*
2431                  * Call vb2_qbuf and give buffer to the driver.
2432                  */
2433                 b->planes[0].bytesused = buf->pos;
2434
2435                 if (copy_timestamp)
2436                         b->timestamp = ktime_get_ns();
2437                 ret = vb2_core_qbuf(q, index, NULL);
2438                 dprintk(5, "vb2_dbuf result: %d\n", ret);
2439                 if (ret)
2440                         return ret;
2441
2442                 /*
2443                  * Buffer has been queued, update the status
2444                  */
2445                 buf->pos = 0;
2446                 buf->queued = 1;
2447                 buf->size = vb2_plane_size(q->bufs[index], 0);
2448                 fileio->q_count += 1;
2449                 /*
2450                  * If we are queuing up buffers for the first time, then
2451                  * increase initial_index by one.
2452                  */
2453                 if (fileio->initial_index < q->num_buffers)
2454                         fileio->initial_index++;
2455                 /*
2456                  * The next buffer to use is either a buffer that's going to be
2457                  * queued for the first time (initial_index < q->num_buffers)
2458                  * or it is equal to q->num_buffers, meaning that the next
2459                  * time we need to dequeue a buffer since we've now queued up
2460                  * all the 'first time' buffers.
2461                  */
2462                 fileio->cur_index = fileio->initial_index;
2463         }
2464
2465         /*
2466          * Return proper number of bytes processed.
2467          */
2468         if (ret == 0)
2469                 ret = count;
2470         return ret;
2471 }
2472
2473 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2474                 loff_t *ppos, int nonblocking)
2475 {
2476         return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2477 }
2478 EXPORT_SYMBOL_GPL(vb2_read);
2479
2480 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2481                 loff_t *ppos, int nonblocking)
2482 {
2483         return __vb2_perform_fileio(q, (char __user *) data, count,
2484                                                         ppos, nonblocking, 0);
2485 }
2486 EXPORT_SYMBOL_GPL(vb2_write);
2487
2488 struct vb2_threadio_data {
2489         struct task_struct *thread;
2490         vb2_thread_fnc fnc;
2491         void *priv;
2492         bool stop;
2493 };
2494
2495 static int vb2_thread(void *data)
2496 {
2497         struct vb2_queue *q = data;
2498         struct vb2_threadio_data *threadio = q->threadio;
2499         bool copy_timestamp = false;
2500         unsigned prequeue = 0;
2501         unsigned index = 0;
2502         int ret = 0;
2503
2504         if (q->is_output) {
2505                 prequeue = q->num_buffers;
2506                 copy_timestamp = q->copy_timestamp;
2507         }
2508
2509         set_freezable();
2510
2511         for (;;) {
2512                 struct vb2_buffer *vb;
2513
2514                 /*
2515                  * Call vb2_dqbuf to get buffer back.
2516                  */
2517                 if (prequeue) {
2518                         vb = q->bufs[index++];
2519                         prequeue--;
2520                 } else {
2521                         call_void_qop(q, wait_finish, q);
2522                         if (!threadio->stop)
2523                                 ret = vb2_core_dqbuf(q, &index, NULL, 0);
2524                         call_void_qop(q, wait_prepare, q);
2525                         dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
2526                         if (!ret)
2527                                 vb = q->bufs[index];
2528                 }
2529                 if (ret || threadio->stop)
2530                         break;
2531                 try_to_freeze();
2532
2533                 if (vb->state != VB2_BUF_STATE_ERROR)
2534                         if (threadio->fnc(vb, threadio->priv))
2535                                 break;
2536                 call_void_qop(q, wait_finish, q);
2537                 if (copy_timestamp)
2538                         vb->timestamp = ktime_get_ns();
2539                 if (!threadio->stop)
2540                         ret = vb2_core_qbuf(q, vb->index, NULL);
2541                 call_void_qop(q, wait_prepare, q);
2542                 if (ret || threadio->stop)
2543                         break;
2544         }
2545
2546         /* Hmm, linux becomes *very* unhappy without this ... */
2547         while (!kthread_should_stop()) {
2548                 set_current_state(TASK_INTERRUPTIBLE);
2549                 schedule();
2550         }
2551         return 0;
2552 }
2553
2554 /*
2555  * This function should not be used for anything else but the videobuf2-dvb
2556  * support. If you think you have another good use-case for this, then please
2557  * contact the linux-media mailinglist first.
2558  */
2559 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
2560                      const char *thread_name)
2561 {
2562         struct vb2_threadio_data *threadio;
2563         int ret = 0;
2564
2565         if (q->threadio)
2566                 return -EBUSY;
2567         if (vb2_is_busy(q))
2568                 return -EBUSY;
2569         if (WARN_ON(q->fileio))
2570                 return -EBUSY;
2571
2572         threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
2573         if (threadio == NULL)
2574                 return -ENOMEM;
2575         threadio->fnc = fnc;
2576         threadio->priv = priv;
2577
2578         ret = __vb2_init_fileio(q, !q->is_output);
2579         dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
2580         if (ret)
2581                 goto nomem;
2582         q->threadio = threadio;
2583         threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
2584         if (IS_ERR(threadio->thread)) {
2585                 ret = PTR_ERR(threadio->thread);
2586                 threadio->thread = NULL;
2587                 goto nothread;
2588         }
2589         return 0;
2590
2591 nothread:
2592         __vb2_cleanup_fileio(q);
2593 nomem:
2594         kfree(threadio);
2595         return ret;
2596 }
2597 EXPORT_SYMBOL_GPL(vb2_thread_start);
2598
2599 int vb2_thread_stop(struct vb2_queue *q)
2600 {
2601         struct vb2_threadio_data *threadio = q->threadio;
2602         int err;
2603
2604         if (threadio == NULL)
2605                 return 0;
2606         threadio->stop = true;
2607         /* Wake up all pending sleeps in the thread */
2608         vb2_queue_error(q);
2609         err = kthread_stop(threadio->thread);
2610         __vb2_cleanup_fileio(q);
2611         threadio->thread = NULL;
2612         kfree(threadio);
2613         q->threadio = NULL;
2614         return err;
2615 }
2616 EXPORT_SYMBOL_GPL(vb2_thread_stop);
2617
2618 MODULE_DESCRIPTION("Media buffer core framework");
2619 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2620 MODULE_LICENSE("GPL");