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(q, level, fmt, arg...)                                  \
  38         do {                                                            \
  39                 if (debug >= level)                                     \
  40                         pr_info("[%s] %s: " fmt, (q)->name, __func__,   \
  41                                 ## arg);                                \
  42         } while (0)
  43
  44 #ifdef CONFIG_VIDEO_ADV_DEBUG
  45
  46 /*
  47  * If advanced debugging is on, then count how often each op is called
  48  * successfully, which can either be per-buffer or per-queue.
  49  *
  50  * This makes it easy to check that the 'init' and 'cleanup'
  51  * (and variations thereof) stay balanced.
  52  */
  53
  54 #define log_memop(vb, op)                                               \
  55         dprintk((vb)->vb2_queue, 2, "call_memop(%d, %s)%s\n",           \
  56                 (vb)->index, #op,                                       \
  57                 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
  58
  59 #define call_memop(vb, op, args...)                                     \
  60 ({                                                                      \
  61         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  62         int err;                                                        \
  63                                                                         \
  64         log_memop(vb, op);                                              \
  65         err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0;              \
  66         if (!err)                                                       \
  67                 (vb)->cnt_mem_ ## op++;                                 \
  68         err;                                                            \
  69 })
  70
  71 #define call_ptr_memop(op, vb, args...)                                 \
  72 ({                                                                      \
  73         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  74         void *ptr;                                                      \
  75                                                                         \
  76         log_memop(vb, op);                                              \
  77         ptr = _q->mem_ops->op ? _q->mem_ops->op(vb, args) : NULL;       \
  78         if (!IS_ERR_OR_NULL(ptr))                                       \
  79                 (vb)->cnt_mem_ ## op++;                                 \
  80         ptr;                                                            \
  81 })
  82
  83 #define call_void_memop(vb, op, args...)                                \
  84 ({                                                                      \
  85         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  86                                                                         \
  87         log_memop(vb, op);                                              \
  88         if (_q->mem_ops->op)                                            \
  89                 _q->mem_ops->op(args);                                  \
  90         (vb)->cnt_mem_ ## op++;                                         \
  91 })
  92
  93 #define log_qop(q, op)                                                  \
  94         dprintk(q, 2, "call_qop(%s)%s\n", #op,                          \
  95                 (q)->ops->op ? "" : " (nop)")
  96
  97 #define call_qop(q, op, args...)                                        \
  98 ({                                                                      \
  99         int err;                                                        \
 100                                                                         \
 101         log_qop(q, op);                                                 \
 102         err = (q)->ops->op ? (q)->ops->op(args) : 0;                    \
 103         if (!err)                                                       \
 104                 (q)->cnt_ ## op++;                                      \
 105         err;                                                            \
 106 })
 107
 108 #define call_void_qop(q, op, args...)                                   \
 109 ({                                                                      \
 110         log_qop(q, op);                                                 \
 111         if ((q)->ops->op)                                               \
 112                 (q)->ops->op(args);                                     \
 113         (q)->cnt_ ## op++;                                              \
 114 })
 115
 116 #define log_vb_qop(vb, op, args...)                                     \
 117         dprintk((vb)->vb2_queue, 2, "call_vb_qop(%d, %s)%s\n",          \
 118                 (vb)->index, #op,                                       \
 119                 (vb)->vb2_queue->ops->op ? "" : " (nop)")
 120
 121 #define call_vb_qop(vb, op, args...)                                    \
 122 ({                                                                      \
 123         int err;                                                        \
 124                                                                         \
 125         log_vb_qop(vb, op);                                             \
 126         err = (vb)->vb2_queue->ops->op ?                                \
 127                 (vb)->vb2_queue->ops->op(args) : 0;                     \
 128         if (!err)                                                       \
 129                 (vb)->cnt_ ## op++;                                     \
 130         err;                                                            \
 131 })
 132
 133 #define call_void_vb_qop(vb, op, args...)                               \
 134 ({                                                                      \
 135         log_vb_qop(vb, op);                                             \
 136         if ((vb)->vb2_queue->ops->op)                                   \
 137                 (vb)->vb2_queue->ops->op(args);                         \
 138         (vb)->cnt_ ## op++;                                             \
 139 })
 140
 141 #else
 142
 143 #define call_memop(vb, op, args...)                                     \
 144         ((vb)->vb2_queue->mem_ops->op ?                                 \
 145                 (vb)->vb2_queue->mem_ops->op(args) : 0)
 146
 147 #define call_ptr_memop(op, vb, args...)                                 \
 148         ((vb)->vb2_queue->mem_ops->op ?                                 \
 149                 (vb)->vb2_queue->mem_ops->op(vb, args) : NULL)
 150
 151 #define call_void_memop(vb, op, args...)                                \
 152         do {                                                            \
 153                 if ((vb)->vb2_queue->mem_ops->op)                       \
 154                         (vb)->vb2_queue->mem_ops->op(args);             \
 155         } while (0)
 156
 157 #define call_qop(q, op, args...)                                        \
 158         ((q)->ops->op ? (q)->ops->op(args) : 0)
 159
 160 #define call_void_qop(q, op, args...)                                   \
 161         do {                                                            \
 162                 if ((q)->ops->op)                                       \
 163                         (q)->ops->op(args);                             \
 164         } while (0)
 165
 166 #define call_vb_qop(vb, op, args...)                                    \
 167         ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
 168
 169 #define call_void_vb_qop(vb, op, args...)                               \
 170         do {                                                            \
 171                 if ((vb)->vb2_queue->ops->op)                           \
 172                         (vb)->vb2_queue->ops->op(args);                 \
 173         } while (0)
 174
 175 #endif
 176
 177 #define call_bufop(q, op, args...)                                      \
 178 ({                                                                      \
 179         int ret = 0;                                                    \
 180         if (q && q->buf_ops && q->buf_ops->op)                          \
 181                 ret = q->buf_ops->op(args);                             \
 182         ret;                                                            \
 183 })
 184
 185 #define call_void_bufop(q, op, args...)                                 \
 186 ({                                                                      \
 187         if (q && q->buf_ops && q->buf_ops->op)                          \
 188                 q->buf_ops->op(args);                                   \
 189 })
 190
 191 static void __vb2_queue_cancel(struct vb2_queue *q);
 192 static void __enqueue_in_driver(struct vb2_buffer *vb);
 193
 194 static const char *vb2_state_name(enum vb2_buffer_state s)
 195 {
 196         static const char * const state_names[] = {
 197                 [VB2_BUF_STATE_DEQUEUED] = "dequeued",
 198                 [VB2_BUF_STATE_IN_REQUEST] = "in request",
 199                 [VB2_BUF_STATE_PREPARING] = "preparing",
 200                 [VB2_BUF_STATE_QUEUED] = "queued",
 201                 [VB2_BUF_STATE_ACTIVE] = "active",
 202                 [VB2_BUF_STATE_DONE] = "done",
 203                 [VB2_BUF_STATE_ERROR] = "error",
 204         };
 205
 206         if ((unsigned int)(s) < ARRAY_SIZE(state_names))
 207                 return state_names[s];
 208         return "unknown";
 209 }
 210
 211 /*
 212  * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
 213  */
 214 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
 215 {
 216         struct vb2_queue *q = vb->vb2_queue;
 217         void *mem_priv;
 218         int plane;
 219         int ret = -ENOMEM;
 220
 221         /*
 222          * Allocate memory for all planes in this buffer
 223          * NOTE: mmapped areas should be page aligned
 224          */
 225         for (plane = 0; plane < vb->num_planes; ++plane) {
 226                 /* Memops alloc requires size to be page aligned. */
 227                 unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
 228
 229                 /* Did it wrap around? */
 230                 if (size < vb->planes[plane].length)
 231                         goto free;
 232
 233                 mem_priv = call_ptr_memop(alloc,
 234                                           vb,
 235                                           q->alloc_devs[plane] ? : q->dev,
 236                                           size);
 237                 if (IS_ERR_OR_NULL(mem_priv)) {
 238                         if (mem_priv)
 239                                 ret = PTR_ERR(mem_priv);
 240                         goto free;
 241                 }
 242
 243                 /* Associate allocator private data with this plane */
 244                 vb->planes[plane].mem_priv = mem_priv;
 245         }
 246
 247         return 0;
 248 free:
 249         /* Free already allocated memory if one of the allocations failed */
 250         for (; plane > 0; --plane) {
 251                 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
 252                 vb->planes[plane - 1].mem_priv = NULL;
 253         }
 254
 255         return ret;
 256 }
 257
 258 /*
 259  * __vb2_buf_mem_free() - free memory of the given buffer
 260  */
 261 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
 262 {
 263         unsigned int plane;
 264
 265         for (plane = 0; plane < vb->num_planes; ++plane) {
 266                 call_void_memop(vb, put, vb->planes[plane].mem_priv);
 267                 vb->planes[plane].mem_priv = NULL;
 268                 dprintk(vb->vb2_queue, 3, "freed plane %d of buffer %d\n",
 269                         plane, vb->index);
 270         }
 271 }
 272
 273 /*
 274  * __vb2_buf_userptr_put() - release userspace memory associated with
 275  * a USERPTR buffer
 276  */
 277 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
 278 {
 279         unsigned int plane;
 280
 281         for (plane = 0; plane < vb->num_planes; ++plane) {
 282                 if (vb->planes[plane].mem_priv)
 283                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
 284                 vb->planes[plane].mem_priv = NULL;
 285         }
 286 }
 287
 288 /*
 289  * __vb2_plane_dmabuf_put() - release memory associated with
 290  * a DMABUF shared plane
 291  */
 292 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
 293 {
 294         if (!p->mem_priv)
 295                 return;
 296
 297         if (p->dbuf_mapped)
 298                 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
 299
 300         call_void_memop(vb, detach_dmabuf, p->mem_priv);
 301         dma_buf_put(p->dbuf);
 302         p->mem_priv = NULL;
 303         p->dbuf = NULL;
 304         p->dbuf_mapped = 0;
 305 }
 306
 307 /*
 308  * __vb2_buf_dmabuf_put() - release memory associated with
 309  * a DMABUF shared buffer
 310  */
 311 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
 312 {
 313         unsigned int plane;
 314
 315         for (plane = 0; plane < vb->num_planes; ++plane)
 316                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
 317 }
 318
 319 /*
 320  * __vb2_buf_mem_prepare() - call ->prepare() on buffer's private memory
 321  * to sync caches
 322  */
 323 static void __vb2_buf_mem_prepare(struct vb2_buffer *vb)
 324 {
 325         unsigned int plane;
 326
 327         if (vb->synced)
 328                 return;
 329
 330         vb->synced = 1;
 331         for (plane = 0; plane < vb->num_planes; ++plane)
 332                 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
 333 }
 334
 335 /*
 336  * __vb2_buf_mem_finish() - call ->finish on buffer's private memory
 337  * to sync caches
 338  */
 339 static void __vb2_buf_mem_finish(struct vb2_buffer *vb)
 340 {
 341         unsigned int plane;
 342
 343         if (!vb->synced)
 344                 return;
 345
 346         vb->synced = 0;
 347         for (plane = 0; plane < vb->num_planes; ++plane)
 348                 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
 349 }
 350
 351 /*
 352  * __setup_offsets() - setup unique offsets ("cookies") for every plane in
 353  * the buffer.
 354  */
 355 static void __setup_offsets(struct vb2_buffer *vb)
 356 {
 357         struct vb2_queue *q = vb->vb2_queue;
 358         unsigned int plane;
 359         unsigned long off = 0;
 360
 361         if (vb->index) {
 362                 struct vb2_buffer *prev = q->bufs[vb->index - 1];
 363                 struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
 364
 365                 off = PAGE_ALIGN(p->m.offset + p->length);
 366         }
 367
 368         for (plane = 0; plane < vb->num_planes; ++plane) {
 369                 vb->planes[plane].m.offset = off;
 370
 371                 dprintk(q, 3, "buffer %d, plane %d offset 0x%08lx\n",
 372                                 vb->index, plane, off);
 373
 374                 off += vb->planes[plane].length;
 375                 off = PAGE_ALIGN(off);
 376         }
 377 }
 378
 379 static void init_buffer_cache_hints(struct vb2_queue *q, struct vb2_buffer *vb)
 380 {
 381         /*
 382          * DMA exporter should take care of cache syncs, so we can avoid
 383          * explicit ->prepare()/->finish() syncs. For other ->memory types
 384          * we always need ->prepare() or/and ->finish() cache sync.
 385          */
 386         if (q->memory == VB2_MEMORY_DMABUF) {
 387                 vb->skip_cache_sync_on_finish = 1;
 388                 vb->skip_cache_sync_on_prepare = 1;
 389                 return;
 390         }
 391
 392         /*
 393          * ->finish() cache sync can be avoided when queue direction is
 394          * TO_DEVICE.
 395          */
 396         if (q->dma_dir == DMA_TO_DEVICE)
 397                 vb->skip_cache_sync_on_finish = 1;
 398 }
 399
 400 /*
 401  * __vb2_queue_alloc() - allocate vb2 buffer structures and (for MMAP type)
 402  * video buffer memory for all buffers/planes on the queue and initializes the
 403  * queue
 404  *
 405  * Returns the number of buffers successfully allocated.
 406  */
 407 static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
 408                              unsigned int num_buffers, unsigned int num_planes,
 409                              const unsigned plane_sizes[VB2_MAX_PLANES])
 410 {
 411         unsigned int buffer, plane;
 412         struct vb2_buffer *vb;
 413         int ret;
 414
 415         /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
 416         num_buffers = min_t(unsigned int, num_buffers,
 417                             VB2_MAX_FRAME - q->num_buffers);
 418
 419         for (buffer = 0; buffer < num_buffers; ++buffer) {
 420                 /* Allocate vb2 buffer structures */
 421                 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
 422                 if (!vb) {
 423                         dprintk(q, 1, "memory alloc for buffer struct failed\n");
 424                         break;
 425                 }
 426
 427                 vb->state = VB2_BUF_STATE_DEQUEUED;
 428                 vb->vb2_queue = q;
 429                 vb->num_planes = num_planes;
 430                 vb->index = q->num_buffers + buffer;
 431                 vb->type = q->type;
 432                 vb->memory = memory;
 433                 init_buffer_cache_hints(q, vb);
 434                 for (plane = 0; plane < num_planes; ++plane) {
 435                         vb->planes[plane].length = plane_sizes[plane];
 436                         vb->planes[plane].min_length = plane_sizes[plane];
 437                 }
 438                 call_void_bufop(q, init_buffer, vb);
 439
 440                 q->bufs[vb->index] = vb;
 441
 442                 /* Allocate video buffer memory for the MMAP type */
 443                 if (memory == VB2_MEMORY_MMAP) {
 444                         ret = __vb2_buf_mem_alloc(vb);
 445                         if (ret) {
 446                                 dprintk(q, 1, "failed allocating memory for buffer %d\n",
 447                                         buffer);
 448                                 q->bufs[vb->index] = NULL;
 449                                 kfree(vb);
 450                                 break;
 451                         }
 452                         __setup_offsets(vb);
 453                         /*
 454                          * Call the driver-provided buffer initialization
 455                          * callback, if given. An error in initialization
 456                          * results in queue setup failure.
 457                          */
 458                         ret = call_vb_qop(vb, buf_init, vb);
 459                         if (ret) {
 460                                 dprintk(q, 1, "buffer %d %p initialization failed\n",
 461                                         buffer, vb);
 462                                 __vb2_buf_mem_free(vb);
 463                                 q->bufs[vb->index] = NULL;
 464                                 kfree(vb);
 465                                 break;
 466                         }
 467                 }
 468         }
 469
 470         dprintk(q, 3, "allocated %d buffers, %d plane(s) each\n",
 471                 buffer, num_planes);
 472
 473         return buffer;
 474 }
 475
 476 /*
 477  * __vb2_free_mem() - release all video buffer memory for a given queue
 478  */
 479 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
 480 {
 481         unsigned int buffer;
 482         struct vb2_buffer *vb;
 483
 484         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 485              ++buffer) {
 486                 vb = q->bufs[buffer];
 487                 if (!vb)
 488                         continue;
 489
 490                 /* Free MMAP buffers or release USERPTR buffers */
 491                 if (q->memory == VB2_MEMORY_MMAP)
 492                         __vb2_buf_mem_free(vb);
 493                 else if (q->memory == VB2_MEMORY_DMABUF)
 494                         __vb2_buf_dmabuf_put(vb);
 495                 else
 496                         __vb2_buf_userptr_put(vb);
 497         }
 498 }
 499
 500 /*
 501  * __vb2_queue_free() - free buffers at the end of the queue - video memory and
 502  * related information, if no buffers are left return the queue to an
 503  * uninitialized state. Might be called even if the queue has already been freed.
 504  */
 505 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
 506 {
 507         unsigned int buffer;
 508
 509         /*
 510          * Sanity check: when preparing a buffer the queue lock is released for
 511          * a short while (see __buf_prepare for the details), which would allow
 512          * a race with a reqbufs which can call this function. Removing the
 513          * buffers from underneath __buf_prepare is obviously a bad idea, so we
 514          * check if any of the buffers is in the state PREPARING, and if so we
 515          * just return -EAGAIN.
 516          */
 517         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 518              ++buffer) {
 519                 if (q->bufs[buffer] == NULL)
 520                         continue;
 521                 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
 522                         dprintk(q, 1, "preparing buffers, cannot free\n");
 523                         return -EAGAIN;
 524                 }
 525         }
 526
 527         /* Call driver-provided cleanup function for each buffer, if provided */
 528         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 529              ++buffer) {
 530                 struct vb2_buffer *vb = q->bufs[buffer];
 531
 532                 if (vb && vb->planes[0].mem_priv)
 533                         call_void_vb_qop(vb, buf_cleanup, vb);
 534         }
 535
 536         /* Release video buffer memory */
 537         __vb2_free_mem(q, buffers);
 538
 539 #ifdef CONFIG_VIDEO_ADV_DEBUG
 540         /*
 541          * Check that all the calls were balances during the life-time of this
 542          * queue. If not (or if the debug level is 1 or up), then dump the
 543          * counters to the kernel log.
 544          */
 545         if (q->num_buffers) {
 546                 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
 547                                   q->cnt_prepare_streaming != q->cnt_unprepare_streaming ||
 548                                   q->cnt_wait_prepare != q->cnt_wait_finish;
 549
 550                 if (unbalanced || debug) {
 551                         pr_info("counters for queue %p:%s\n", q,
 552                                 unbalanced ? " UNBALANCED!" : "");
 553                         pr_info("     setup: %u start_streaming: %u stop_streaming: %u\n",
 554                                 q->cnt_queue_setup, q->cnt_start_streaming,
 555                                 q->cnt_stop_streaming);
 556                         pr_info("     prepare_streaming: %u unprepare_streaming: %u\n",
 557                                 q->cnt_prepare_streaming, q->cnt_unprepare_streaming);
 558                         pr_info("     wait_prepare: %u wait_finish: %u\n",
 559                                 q->cnt_wait_prepare, q->cnt_wait_finish);
 560                 }
 561                 q->cnt_queue_setup = 0;
 562                 q->cnt_wait_prepare = 0;
 563                 q->cnt_wait_finish = 0;
 564                 q->cnt_prepare_streaming = 0;
 565                 q->cnt_start_streaming = 0;
 566                 q->cnt_stop_streaming = 0;
 567                 q->cnt_unprepare_streaming = 0;
 568         }
 569         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 570                 struct vb2_buffer *vb = q->bufs[buffer];
 571                 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
 572                                   vb->cnt_mem_prepare != vb->cnt_mem_finish ||
 573                                   vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
 574                                   vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
 575                                   vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
 576                                   vb->cnt_buf_queue != vb->cnt_buf_done ||
 577                                   vb->cnt_buf_prepare != vb->cnt_buf_finish ||
 578                                   vb->cnt_buf_init != vb->cnt_buf_cleanup;
 579
 580                 if (unbalanced || debug) {
 581                         pr_info("   counters for queue %p, buffer %d:%s\n",
 582                                 q, buffer, unbalanced ? " UNBALANCED!" : "");
 583                         pr_info("     buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
 584                                 vb->cnt_buf_init, vb->cnt_buf_cleanup,
 585                                 vb->cnt_buf_prepare, vb->cnt_buf_finish);
 586                         pr_info("     buf_out_validate: %u buf_queue: %u buf_done: %u buf_request_complete: %u\n",
 587                                 vb->cnt_buf_out_validate, vb->cnt_buf_queue,
 588                                 vb->cnt_buf_done, vb->cnt_buf_request_complete);
 589                         pr_info("     alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
 590                                 vb->cnt_mem_alloc, vb->cnt_mem_put,
 591                                 vb->cnt_mem_prepare, vb->cnt_mem_finish,
 592                                 vb->cnt_mem_mmap);
 593                         pr_info("     get_userptr: %u put_userptr: %u\n",
 594                                 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
 595                         pr_info("     attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
 596                                 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
 597                                 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
 598                         pr_info("     get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
 599                                 vb->cnt_mem_get_dmabuf,
 600                                 vb->cnt_mem_num_users,
 601                                 vb->cnt_mem_vaddr,
 602                                 vb->cnt_mem_cookie);
 603                 }
 604         }
 605 #endif
 606
 607         /* Free vb2 buffers */
 608         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 609              ++buffer) {
 610                 kfree(q->bufs[buffer]);
 611                 q->bufs[buffer] = NULL;
 612         }
 613
 614         q->num_buffers -= buffers;
 615         if (!q->num_buffers) {
 616                 q->memory = VB2_MEMORY_UNKNOWN;
 617                 INIT_LIST_HEAD(&q->queued_list);
 618         }
 619         return 0;
 620 }
 621
 622 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
 623 {
 624         unsigned int plane;
 625         for (plane = 0; plane < vb->num_planes; ++plane) {
 626                 void *mem_priv = vb->planes[plane].mem_priv;
 627                 /*
 628                  * If num_users() has not been provided, call_memop
 629                  * will return 0, apparently nobody cares about this
 630                  * case anyway. If num_users() returns more than 1,
 631                  * we are not the only user of the plane's memory.
 632                  */
 633                 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
 634                         return true;
 635         }
 636         return false;
 637 }
 638 EXPORT_SYMBOL(vb2_buffer_in_use);
 639
 640 /*
 641  * __buffers_in_use() - return true if any buffers on the queue are in use and
 642  * the queue cannot be freed (by the means of REQBUFS(0)) call
 643  */
 644 static bool __buffers_in_use(struct vb2_queue *q)
 645 {
 646         unsigned int buffer;
 647         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 648                 if (vb2_buffer_in_use(q, q->bufs[buffer]))
 649                         return true;
 650         }
 651         return false;
 652 }
 653
 654 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
 655 {
 656         call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
 657 }
 658 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
 659
 660 /*
 661  * __verify_userptr_ops() - verify that all memory operations required for
 662  * USERPTR queue type have been provided
 663  */
 664 static int __verify_userptr_ops(struct vb2_queue *q)
 665 {
 666         if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
 667             !q->mem_ops->put_userptr)
 668                 return -EINVAL;
 669
 670         return 0;
 671 }
 672
 673 /*
 674  * __verify_mmap_ops() - verify that all memory operations required for
 675  * MMAP queue type have been provided
 676  */
 677 static int __verify_mmap_ops(struct vb2_queue *q)
 678 {
 679         if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
 680             !q->mem_ops->put || !q->mem_ops->mmap)
 681                 return -EINVAL;
 682
 683         return 0;
 684 }
 685
 686 /*
 687  * __verify_dmabuf_ops() - verify that all memory operations required for
 688  * DMABUF queue type have been provided
 689  */
 690 static int __verify_dmabuf_ops(struct vb2_queue *q)
 691 {
 692         if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
 693             !q->mem_ops->detach_dmabuf  || !q->mem_ops->map_dmabuf ||
 694             !q->mem_ops->unmap_dmabuf)
 695                 return -EINVAL;
 696
 697         return 0;
 698 }
 699
 700 int vb2_verify_memory_type(struct vb2_queue *q,
 701                 enum vb2_memory memory, unsigned int type)
 702 {
 703         if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
 704             memory != VB2_MEMORY_DMABUF) {
 705                 dprintk(q, 1, "unsupported memory type\n");
 706                 return -EINVAL;
 707         }
 708
 709         if (type != q->type) {
 710                 dprintk(q, 1, "requested type is incorrect\n");
 711                 return -EINVAL;
 712         }
 713
 714         /*
 715          * Make sure all the required memory ops for given memory type
 716          * are available.
 717          */
 718         if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
 719                 dprintk(q, 1, "MMAP for current setup unsupported\n");
 720                 return -EINVAL;
 721         }
 722
 723         if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
 724                 dprintk(q, 1, "USERPTR for current setup unsupported\n");
 725                 return -EINVAL;
 726         }
 727
 728         if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
 729                 dprintk(q, 1, "DMABUF for current setup unsupported\n");
 730                 return -EINVAL;
 731         }
 732
 733         /*
 734          * Place the busy tests at the end: -EBUSY can be ignored when
 735          * create_bufs is called with count == 0, but count == 0 should still
 736          * do the memory and type validation.
 737          */
 738         if (vb2_fileio_is_active(q)) {
 739                 dprintk(q, 1, "file io in progress\n");
 740                 return -EBUSY;
 741         }
 742         return 0;
 743 }
 744 EXPORT_SYMBOL(vb2_verify_memory_type);
 745
 746 static void set_queue_coherency(struct vb2_queue *q, bool non_coherent_mem)
 747 {
 748         q->non_coherent_mem = 0;
 749
 750         if (!vb2_queue_allows_cache_hints(q))
 751                 return;
 752         q->non_coherent_mem = non_coherent_mem;
 753 }
 754
 755 static bool verify_coherency_flags(struct vb2_queue *q, bool non_coherent_mem)
 756 {
 757         if (non_coherent_mem != q->non_coherent_mem) {
 758                 dprintk(q, 1, "memory coherency model mismatch\n");
 759                 return false;
 760         }
 761         return true;
 762 }
 763
 764 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 765                      unsigned int flags, unsigned int *count)
 766 {
 767         unsigned int num_buffers, allocated_buffers, num_planes = 0;
 768         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 769         bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
 770         unsigned int i;
 771         int ret;
 772
 773         if (q->streaming) {
 774                 dprintk(q, 1, "streaming active\n");
 775                 return -EBUSY;
 776         }
 777
 778         if (q->waiting_in_dqbuf && *count) {
 779                 dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
 780                 return -EBUSY;
 781         }
 782
 783         if (*count == 0 || q->num_buffers != 0 ||
 784             (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory) ||
 785             !verify_coherency_flags(q, non_coherent_mem)) {
 786                 /*
 787                  * We already have buffers allocated, so first check if they
 788                  * are not in use and can be freed.
 789                  */
 790                 mutex_lock(&q->mmap_lock);
 791                 if (debug && q->memory == VB2_MEMORY_MMAP &&
 792                     __buffers_in_use(q))
 793                         dprintk(q, 1, "memory in use, orphaning buffers\n");
 794
 795                 /*
 796                  * Call queue_cancel to clean up any buffers in the
 797                  * QUEUED state which is possible if buffers were prepared or
 798                  * queued without ever calling STREAMON.
 799                  */
 800                 __vb2_queue_cancel(q);
 801                 ret = __vb2_queue_free(q, q->num_buffers);
 802                 mutex_unlock(&q->mmap_lock);
 803                 if (ret)
 804                         return ret;
 805
 806                 /*
 807                  * In case of REQBUFS(0) return immediately without calling
 808                  * driver's queue_setup() callback and allocating resources.
 809                  */
 810                 if (*count == 0)
 811                         return 0;
 812         }
 813
 814         /*
 815          * Make sure the requested values and current defaults are sane.
 816          */
 817         WARN_ON(q->min_buffers_needed > VB2_MAX_FRAME);
 818         num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);
 819         num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);
 820         memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 821         /*
 822          * Set this now to ensure that drivers see the correct q->memory value
 823          * in the queue_setup op.
 824          */
 825         mutex_lock(&q->mmap_lock);
 826         q->memory = memory;
 827         mutex_unlock(&q->mmap_lock);
 828         set_queue_coherency(q, non_coherent_mem);
 829
 830         /*
 831          * Ask the driver how many buffers and planes per buffer it requires.
 832          * Driver also sets the size and allocator context for each plane.
 833          */
 834         ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
 835                        plane_sizes, q->alloc_devs);
 836         if (ret)
 837                 goto error;
 838
 839         /* Check that driver has set sane values */
 840         if (WARN_ON(!num_planes)) {
 841                 ret = -EINVAL;
 842                 goto error;
 843         }
 844
 845         for (i = 0; i < num_planes; i++)
 846                 if (WARN_ON(!plane_sizes[i])) {
 847                         ret = -EINVAL;
 848                         goto error;
 849                 }
 850
 851         /* Finally, allocate buffers and video memory */
 852         allocated_buffers =
 853                 __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
 854         if (allocated_buffers == 0) {
 855                 dprintk(q, 1, "memory allocation failed\n");
 856                 ret = -ENOMEM;
 857                 goto error;
 858         }
 859
 860         /*
 861          * There is no point in continuing if we can't allocate the minimum
 862          * number of buffers needed by this vb2_queue.
 863          */
 864         if (allocated_buffers < q->min_buffers_needed)
 865                 ret = -ENOMEM;
 866
 867         /*
 868          * Check if driver can handle the allocated number of buffers.
 869          */
 870         if (!ret && allocated_buffers < num_buffers) {
 871                 num_buffers = allocated_buffers;
 872                 /*
 873                  * num_planes is set by the previous queue_setup(), but since it
 874                  * signals to queue_setup() whether it is called from create_bufs()
 875                  * vs reqbufs() we zero it here to signal that queue_setup() is
 876                  * called for the reqbufs() case.
 877                  */
 878                 num_planes = 0;
 879
 880                 ret = call_qop(q, queue_setup, q, &num_buffers,
 881                                &num_planes, plane_sizes, q->alloc_devs);
 882
 883                 if (!ret && allocated_buffers < num_buffers)
 884                         ret = -ENOMEM;
 885
 886                 /*
 887                  * Either the driver has accepted a smaller number of buffers,
 888                  * or .queue_setup() returned an error
 889                  */
 890         }
 891
 892         mutex_lock(&q->mmap_lock);
 893         q->num_buffers = allocated_buffers;
 894
 895         if (ret < 0) {
 896                 /*
 897                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 898                  * from q->num_buffers and it will reset q->memory to
 899                  * VB2_MEMORY_UNKNOWN.
 900                  */
 901                 __vb2_queue_free(q, allocated_buffers);
 902                 mutex_unlock(&q->mmap_lock);
 903                 return ret;
 904         }
 905         mutex_unlock(&q->mmap_lock);
 906
 907         /*
 908          * Return the number of successfully allocated buffers
 909          * to the userspace.
 910          */
 911         *count = allocated_buffers;
 912         q->waiting_for_buffers = !q->is_output;
 913
 914         return 0;
 915
 916 error:
 917         mutex_lock(&q->mmap_lock);
 918         q->memory = VB2_MEMORY_UNKNOWN;
 919         mutex_unlock(&q->mmap_lock);
 920         return ret;
 921 }
 922 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
 923
 924 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 925                          unsigned int flags, unsigned int *count,
 926                          unsigned int requested_planes,
 927                          const unsigned int requested_sizes[])
 928 {
 929         unsigned int num_planes = 0, num_buffers, allocated_buffers;
 930         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 931         bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
 932         bool no_previous_buffers = !q->num_buffers;
 933         int ret;
 934
 935         if (q->num_buffers == VB2_MAX_FRAME) {
 936                 dprintk(q, 1, "maximum number of buffers already allocated\n");
 937                 return -ENOBUFS;
 938         }
 939
 940         if (no_previous_buffers) {
 941                 if (q->waiting_in_dqbuf && *count) {
 942                         dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
 943                         return -EBUSY;
 944                 }
 945                 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 946                 /*
 947                  * Set this now to ensure that drivers see the correct q->memory
 948                  * value in the queue_setup op.
 949                  */
 950                 mutex_lock(&q->mmap_lock);
 951                 q->memory = memory;
 952                 mutex_unlock(&q->mmap_lock);
 953                 q->waiting_for_buffers = !q->is_output;
 954                 set_queue_coherency(q, non_coherent_mem);
 955         } else {
 956                 if (q->memory != memory) {
 957                         dprintk(q, 1, "memory model mismatch\n");
 958                         return -EINVAL;
 959                 }
 960                 if (!verify_coherency_flags(q, non_coherent_mem))
 961                         return -EINVAL;
 962         }
 963
 964         num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
 965
 966         if (requested_planes && requested_sizes) {
 967                 num_planes = requested_planes;
 968                 memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
 969         }
 970
 971         /*
 972          * Ask the driver, whether the requested number of buffers, planes per
 973          * buffer and their sizes are acceptable
 974          */
 975         ret = call_qop(q, queue_setup, q, &num_buffers,
 976                        &num_planes, plane_sizes, q->alloc_devs);
 977         if (ret)
 978                 goto error;
 979
 980         /* Finally, allocate buffers and video memory */
 981         allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
 982                                 num_planes, plane_sizes);
 983         if (allocated_buffers == 0) {
 984                 dprintk(q, 1, "memory allocation failed\n");
 985                 ret = -ENOMEM;
 986                 goto error;
 987         }
 988
 989         /*
 990          * Check if driver can handle the so far allocated number of buffers.
 991          */
 992         if (allocated_buffers < num_buffers) {
 993                 num_buffers = allocated_buffers;
 994
 995                 /*
 996                  * q->num_buffers contains the total number of buffers, that the
 997                  * queue driver has set up
 998                  */
 999                 ret = call_qop(q, queue_setup, q, &num_buffers,
1000                                &num_planes, plane_sizes, q->alloc_devs);
1001
1002                 if (!ret && allocated_buffers < num_buffers)
1003                         ret = -ENOMEM;
1004
1005                 /*
1006                  * Either the driver has accepted a smaller number of buffers,
1007                  * or .queue_setup() returned an error
1008                  */
1009         }
1010
1011         mutex_lock(&q->mmap_lock);
1012         q->num_buffers += allocated_buffers;
1013
1014         if (ret < 0) {
1015                 /*
1016                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
1017                  * from q->num_buffers and it will reset q->memory to
1018                  * VB2_MEMORY_UNKNOWN.
1019                  */
1020                 __vb2_queue_free(q, allocated_buffers);
1021                 mutex_unlock(&q->mmap_lock);
1022                 return -ENOMEM;
1023         }
1024         mutex_unlock(&q->mmap_lock);
1025
1026         /*
1027          * Return the number of successfully allocated buffers
1028          * to the userspace.
1029          */
1030         *count = allocated_buffers;
1031
1032         return 0;
1033
1034 error:
1035         if (no_previous_buffers) {
1036                 mutex_lock(&q->mmap_lock);
1037                 q->memory = VB2_MEMORY_UNKNOWN;
1038                 mutex_unlock(&q->mmap_lock);
1039         }
1040         return ret;
1041 }
1042 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
1043
1044 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
1045 {
1046         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1047                 return NULL;
1048
1049         return call_ptr_memop(vaddr, vb, vb->planes[plane_no].mem_priv);
1050
1051 }
1052 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
1053
1054 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
1055 {
1056         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1057                 return NULL;
1058
1059         return call_ptr_memop(cookie, vb, vb->planes[plane_no].mem_priv);
1060 }
1061 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
1062
1063 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
1064 {
1065         struct vb2_queue *q = vb->vb2_queue;
1066         unsigned long flags;
1067
1068         if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
1069                 return;
1070
1071         if (WARN_ON(state != VB2_BUF_STATE_DONE &&
1072                     state != VB2_BUF_STATE_ERROR &&
1073                     state != VB2_BUF_STATE_QUEUED))
1074                 state = VB2_BUF_STATE_ERROR;
1075
1076 #ifdef CONFIG_VIDEO_ADV_DEBUG
1077         /*
1078          * Although this is not a callback, it still does have to balance
1079          * with the buf_queue op. So update this counter manually.
1080          */
1081         vb->cnt_buf_done++;
1082 #endif
1083         dprintk(q, 4, "done processing on buffer %d, state: %s\n",
1084                 vb->index, vb2_state_name(state));
1085
1086         if (state != VB2_BUF_STATE_QUEUED)
1087                 __vb2_buf_mem_finish(vb);
1088
1089         spin_lock_irqsave(&q->done_lock, flags);
1090         if (state == VB2_BUF_STATE_QUEUED) {
1091                 vb->state = VB2_BUF_STATE_QUEUED;
1092         } else {
1093                 /* Add the buffer to the done buffers list */
1094                 list_add_tail(&vb->done_entry, &q->done_list);
1095                 vb->state = state;
1096         }
1097         atomic_dec(&q->owned_by_drv_count);
1098
1099         if (state != VB2_BUF_STATE_QUEUED && vb->req_obj.req) {
1100                 media_request_object_unbind(&vb->req_obj);
1101                 media_request_object_put(&vb->req_obj);
1102         }
1103
1104         spin_unlock_irqrestore(&q->done_lock, flags);
1105
1106         trace_vb2_buf_done(q, vb);
1107
1108         switch (state) {
1109         case VB2_BUF_STATE_QUEUED:
1110                 return;
1111         default:
1112                 /* Inform any processes that may be waiting for buffers */
1113                 wake_up(&q->done_wq);
1114                 break;
1115         }
1116 }
1117 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1118
1119 void vb2_discard_done(struct vb2_queue *q)
1120 {
1121         struct vb2_buffer *vb;
1122         unsigned long flags;
1123
1124         spin_lock_irqsave(&q->done_lock, flags);
1125         list_for_each_entry(vb, &q->done_list, done_entry)
1126                 vb->state = VB2_BUF_STATE_ERROR;
1127         spin_unlock_irqrestore(&q->done_lock, flags);
1128 }
1129 EXPORT_SYMBOL_GPL(vb2_discard_done);
1130
1131 /*
1132  * __prepare_mmap() - prepare an MMAP buffer
1133  */
1134 static int __prepare_mmap(struct vb2_buffer *vb)
1135 {
1136         int ret = 0;
1137
1138         ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1139                          vb, vb->planes);
1140         return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
1141 }
1142
1143 /*
1144  * __prepare_userptr() - prepare a USERPTR buffer
1145  */
1146 static int __prepare_userptr(struct vb2_buffer *vb)
1147 {
1148         struct vb2_plane planes[VB2_MAX_PLANES];
1149         struct vb2_queue *q = vb->vb2_queue;
1150         void *mem_priv;
1151         unsigned int plane;
1152         int ret = 0;
1153         bool reacquired = vb->planes[0].mem_priv == NULL;
1154
1155         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1156         /* Copy relevant information provided by the userspace */
1157         ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1158                          vb, planes);
1159         if (ret)
1160                 return ret;
1161
1162         for (plane = 0; plane < vb->num_planes; ++plane) {
1163                 /* Skip the plane if already verified */
1164                 if (vb->planes[plane].m.userptr &&
1165                         vb->planes[plane].m.userptr == planes[plane].m.userptr
1166                         && vb->planes[plane].length == planes[plane].length)
1167                         continue;
1168
1169                 dprintk(q, 3, "userspace address for plane %d changed, reacquiring memory\n",
1170                         plane);
1171
1172                 /* Check if the provided plane buffer is large enough */
1173                 if (planes[plane].length < vb->planes[plane].min_length) {
1174                         dprintk(q, 1, "provided buffer size %u is less than setup size %u for plane %d\n",
1175                                                 planes[plane].length,
1176                                                 vb->planes[plane].min_length,
1177                                                 plane);
1178                         ret = -EINVAL;
1179                         goto err;
1180                 }
1181
1182                 /* Release previously acquired memory if present */
1183                 if (vb->planes[plane].mem_priv) {
1184                         if (!reacquired) {
1185                                 reacquired = true;
1186                                 vb->copied_timestamp = 0;
1187                                 call_void_vb_qop(vb, buf_cleanup, vb);
1188                         }
1189                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1190                 }
1191
1192                 vb->planes[plane].mem_priv = NULL;
1193                 vb->planes[plane].bytesused = 0;
1194                 vb->planes[plane].length = 0;
1195                 vb->planes[plane].m.userptr = 0;
1196                 vb->planes[plane].data_offset = 0;
1197
1198                 /* Acquire each plane's memory */
1199                 mem_priv = call_ptr_memop(get_userptr,
1200                                           vb,
1201                                           q->alloc_devs[plane] ? : q->dev,
1202                                           planes[plane].m.userptr,
1203                                           planes[plane].length);
1204                 if (IS_ERR(mem_priv)) {
1205                         dprintk(q, 1, "failed acquiring userspace memory for plane %d\n",
1206                                 plane);
1207                         ret = PTR_ERR(mem_priv);
1208                         goto err;
1209                 }
1210                 vb->planes[plane].mem_priv = mem_priv;
1211         }
1212
1213         /*
1214          * Now that everything is in order, copy relevant information
1215          * provided by userspace.
1216          */
1217         for (plane = 0; plane < vb->num_planes; ++plane) {
1218                 vb->planes[plane].bytesused = planes[plane].bytesused;
1219                 vb->planes[plane].length = planes[plane].length;
1220                 vb->planes[plane].m.userptr = planes[plane].m.userptr;
1221                 vb->planes[plane].data_offset = planes[plane].data_offset;
1222         }
1223
1224         if (reacquired) {
1225                 /*
1226                  * One or more planes changed, so we must call buf_init to do
1227                  * the driver-specific initialization on the newly acquired
1228                  * buffer, if provided.
1229                  */
1230                 ret = call_vb_qop(vb, buf_init, vb);
1231                 if (ret) {
1232                         dprintk(q, 1, "buffer initialization failed\n");
1233                         goto err;
1234                 }
1235         }
1236
1237         ret = call_vb_qop(vb, buf_prepare, vb);
1238         if (ret) {
1239                 dprintk(q, 1, "buffer preparation failed\n");
1240                 call_void_vb_qop(vb, buf_cleanup, vb);
1241                 goto err;
1242         }
1243
1244         return 0;
1245 err:
1246         /* In case of errors, release planes that were already acquired */
1247         for (plane = 0; plane < vb->num_planes; ++plane) {
1248                 if (vb->planes[plane].mem_priv)
1249                         call_void_memop(vb, put_userptr,
1250                                 vb->planes[plane].mem_priv);
1251                 vb->planes[plane].mem_priv = NULL;
1252                 vb->planes[plane].m.userptr = 0;
1253                 vb->planes[plane].length = 0;
1254         }
1255
1256         return ret;
1257 }
1258
1259 /*
1260  * __prepare_dmabuf() - prepare a DMABUF buffer
1261  */
1262 static int __prepare_dmabuf(struct vb2_buffer *vb)
1263 {
1264         struct vb2_plane planes[VB2_MAX_PLANES];
1265         struct vb2_queue *q = vb->vb2_queue;
1266         void *mem_priv;
1267         unsigned int plane;
1268         int ret = 0;
1269         bool reacquired = vb->planes[0].mem_priv == NULL;
1270
1271         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1272         /* Copy relevant information provided by the userspace */
1273         ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1274                          vb, planes);
1275         if (ret)
1276                 return ret;
1277
1278         for (plane = 0; plane < vb->num_planes; ++plane) {
1279                 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1280
1281                 if (IS_ERR_OR_NULL(dbuf)) {
1282                         dprintk(q, 1, "invalid dmabuf fd for plane %d\n",
1283                                 plane);
1284                         ret = -EINVAL;
1285                         goto err;
1286                 }
1287
1288                 /* use DMABUF size if length is not provided */
1289                 if (planes[plane].length == 0)
1290                         planes[plane].length = dbuf->size;
1291
1292                 if (planes[plane].length < vb->planes[plane].min_length) {
1293                         dprintk(q, 1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
1294                                 planes[plane].length, plane,
1295                                 vb->planes[plane].min_length);
1296                         dma_buf_put(dbuf);
1297                         ret = -EINVAL;
1298                         goto err;
1299                 }
1300
1301                 /* Skip the plane if already verified */
1302                 if (dbuf == vb->planes[plane].dbuf &&
1303                         vb->planes[plane].length == planes[plane].length) {
1304                         dma_buf_put(dbuf);
1305                         continue;
1306                 }
1307
1308                 dprintk(q, 3, "buffer for plane %d changed\n", plane);
1309
1310                 if (!reacquired) {
1311                         reacquired = true;
1312                         vb->copied_timestamp = 0;
1313                         call_void_vb_qop(vb, buf_cleanup, vb);
1314                 }
1315
1316                 /* Release previously acquired memory if present */
1317                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1318                 vb->planes[plane].bytesused = 0;
1319                 vb->planes[plane].length = 0;
1320                 vb->planes[plane].m.fd = 0;
1321                 vb->planes[plane].data_offset = 0;
1322
1323                 /* Acquire each plane's memory */
1324                 mem_priv = call_ptr_memop(attach_dmabuf,
1325                                           vb,
1326                                           q->alloc_devs[plane] ? : q->dev,
1327                                           dbuf,
1328                                           planes[plane].length);
1329                 if (IS_ERR(mem_priv)) {
1330                         dprintk(q, 1, "failed to attach dmabuf\n");
1331                         ret = PTR_ERR(mem_priv);
1332                         dma_buf_put(dbuf);
1333                         goto err;
1334                 }
1335
1336                 vb->planes[plane].dbuf = dbuf;
1337                 vb->planes[plane].mem_priv = mem_priv;
1338         }
1339
1340         /*
1341          * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1342          * here instead just before the DMA, while queueing the buffer(s) so
1343          * userspace knows sooner rather than later if the dma-buf map fails.
1344          */
1345         for (plane = 0; plane < vb->num_planes; ++plane) {
1346                 if (vb->planes[plane].dbuf_mapped)
1347                         continue;
1348
1349                 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1350                 if (ret) {
1351                         dprintk(q, 1, "failed to map dmabuf for plane %d\n",
1352                                 plane);
1353                         goto err;
1354                 }
1355                 vb->planes[plane].dbuf_mapped = 1;
1356         }
1357
1358         /*
1359          * Now that everything is in order, copy relevant information
1360          * provided by userspace.
1361          */
1362         for (plane = 0; plane < vb->num_planes; ++plane) {
1363                 vb->planes[plane].bytesused = planes[plane].bytesused;
1364                 vb->planes[plane].length = planes[plane].length;
1365                 vb->planes[plane].m.fd = planes[plane].m.fd;
1366                 vb->planes[plane].data_offset = planes[plane].data_offset;
1367         }
1368
1369         if (reacquired) {
1370                 /*
1371                  * Call driver-specific initialization on the newly acquired buffer,
1372                  * if provided.
1373                  */
1374                 ret = call_vb_qop(vb, buf_init, vb);
1375                 if (ret) {
1376                         dprintk(q, 1, "buffer initialization failed\n");
1377                         goto err;
1378                 }
1379         }
1380
1381         ret = call_vb_qop(vb, buf_prepare, vb);
1382         if (ret) {
1383                 dprintk(q, 1, "buffer preparation failed\n");
1384                 call_void_vb_qop(vb, buf_cleanup, vb);
1385                 goto err;
1386         }
1387
1388         return 0;
1389 err:
1390         /* In case of errors, release planes that were already acquired */
1391         __vb2_buf_dmabuf_put(vb);
1392
1393         return ret;
1394 }
1395
1396 /*
1397  * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1398  */
1399 static void __enqueue_in_driver(struct vb2_buffer *vb)
1400 {
1401         struct vb2_queue *q = vb->vb2_queue;
1402
1403         vb->state = VB2_BUF_STATE_ACTIVE;
1404         atomic_inc(&q->owned_by_drv_count);
1405
1406         trace_vb2_buf_queue(q, vb);
1407
1408         call_void_vb_qop(vb, buf_queue, vb);
1409 }
1410
1411 static int __buf_prepare(struct vb2_buffer *vb)
1412 {
1413         struct vb2_queue *q = vb->vb2_queue;
1414         enum vb2_buffer_state orig_state = vb->state;
1415         int ret;
1416
1417         if (q->error) {
1418                 dprintk(q, 1, "fatal error occurred on queue\n");
1419                 return -EIO;
1420         }
1421
1422         if (vb->prepared)
1423                 return 0;
1424         WARN_ON(vb->synced);
1425
1426         if (q->is_output) {
1427                 ret = call_vb_qop(vb, buf_out_validate, vb);
1428                 if (ret) {
1429                         dprintk(q, 1, "buffer validation failed\n");
1430                         return ret;
1431                 }
1432         }
1433
1434         vb->state = VB2_BUF_STATE_PREPARING;
1435
1436         switch (q->memory) {
1437         case VB2_MEMORY_MMAP:
1438                 ret = __prepare_mmap(vb);
1439                 break;
1440         case VB2_MEMORY_USERPTR:
1441                 ret = __prepare_userptr(vb);
1442                 break;
1443         case VB2_MEMORY_DMABUF:
1444                 ret = __prepare_dmabuf(vb);
1445                 break;
1446         default:
1447                 WARN(1, "Invalid queue type\n");
1448                 ret = -EINVAL;
1449                 break;
1450         }
1451
1452         if (ret) {
1453                 dprintk(q, 1, "buffer preparation failed: %d\n", ret);
1454                 vb->state = orig_state;
1455                 return ret;
1456         }
1457
1458         __vb2_buf_mem_prepare(vb);
1459         vb->prepared = 1;
1460         vb->state = orig_state;
1461
1462         return 0;
1463 }
1464
1465 static int vb2_req_prepare(struct media_request_object *obj)
1466 {
1467         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1468         int ret;
1469
1470         if (WARN_ON(vb->state != VB2_BUF_STATE_IN_REQUEST))
1471                 return -EINVAL;
1472
1473         mutex_lock(vb->vb2_queue->lock);
1474         ret = __buf_prepare(vb);
1475         mutex_unlock(vb->vb2_queue->lock);
1476         return ret;
1477 }
1478
1479 static void __vb2_dqbuf(struct vb2_buffer *vb);
1480
1481 static void vb2_req_unprepare(struct media_request_object *obj)
1482 {
1483         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1484
1485         mutex_lock(vb->vb2_queue->lock);
1486         __vb2_dqbuf(vb);
1487         vb->state = VB2_BUF_STATE_IN_REQUEST;
1488         mutex_unlock(vb->vb2_queue->lock);
1489         WARN_ON(!vb->req_obj.req);
1490 }
1491
1492 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1493                   struct media_request *req);
1494
1495 static void vb2_req_queue(struct media_request_object *obj)
1496 {
1497         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1498         int err;
1499
1500         mutex_lock(vb->vb2_queue->lock);
1501         /*
1502          * There is no method to propagate an error from vb2_core_qbuf(),
1503          * so if this returns a non-0 value, then WARN.
1504          *
1505          * The only exception is -EIO which is returned if q->error is
1506          * set. We just ignore that, and expect this will be caught the
1507          * next time vb2_req_prepare() is called.
1508          */
1509         err = vb2_core_qbuf(vb->vb2_queue, vb->index, NULL, NULL);
1510         WARN_ON_ONCE(err && err != -EIO);
1511         mutex_unlock(vb->vb2_queue->lock);
1512 }
1513
1514 static void vb2_req_unbind(struct media_request_object *obj)
1515 {
1516         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1517
1518         if (vb->state == VB2_BUF_STATE_IN_REQUEST)
1519                 call_void_bufop(vb->vb2_queue, init_buffer, vb);
1520 }
1521
1522 static void vb2_req_release(struct media_request_object *obj)
1523 {
1524         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1525
1526         if (vb->state == VB2_BUF_STATE_IN_REQUEST) {
1527                 vb->state = VB2_BUF_STATE_DEQUEUED;
1528                 if (vb->request)
1529                         media_request_put(vb->request);
1530                 vb->request = NULL;
1531         }
1532 }
1533
1534 static const struct media_request_object_ops vb2_core_req_ops = {
1535         .prepare = vb2_req_prepare,
1536         .unprepare = vb2_req_unprepare,
1537         .queue = vb2_req_queue,
1538         .unbind = vb2_req_unbind,
1539         .release = vb2_req_release,
1540 };
1541
1542 bool vb2_request_object_is_buffer(struct media_request_object *obj)
1543 {
1544         return obj->ops == &vb2_core_req_ops;
1545 }
1546 EXPORT_SYMBOL_GPL(vb2_request_object_is_buffer);
1547
1548 unsigned int vb2_request_buffer_cnt(struct media_request *req)
1549 {
1550         struct media_request_object *obj;
1551         unsigned long flags;
1552         unsigned int buffer_cnt = 0;
1553
1554         spin_lock_irqsave(&req->lock, flags);
1555         list_for_each_entry(obj, &req->objects, list)
1556                 if (vb2_request_object_is_buffer(obj))
1557                         buffer_cnt++;
1558         spin_unlock_irqrestore(&req->lock, flags);
1559
1560         return buffer_cnt;
1561 }
1562 EXPORT_SYMBOL_GPL(vb2_request_buffer_cnt);
1563
1564 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1565 {
1566         struct vb2_buffer *vb;
1567         int ret;
1568
1569         vb = q->bufs[index];
1570         if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1571                 dprintk(q, 1, "invalid buffer state %s\n",
1572                         vb2_state_name(vb->state));
1573                 return -EINVAL;
1574         }
1575         if (vb->prepared) {
1576                 dprintk(q, 1, "buffer already prepared\n");
1577                 return -EINVAL;
1578         }
1579
1580         ret = __buf_prepare(vb);
1581         if (ret)
1582                 return ret;
1583
1584         /* Fill buffer information for the userspace */
1585         call_void_bufop(q, fill_user_buffer, vb, pb);
1586
1587         dprintk(q, 2, "prepare of buffer %d succeeded\n", vb->index);
1588
1589         return 0;
1590 }
1591 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1592
1593 /*
1594  * vb2_start_streaming() - Attempt to start streaming.
1595  * @q:          videobuf2 queue
1596  *
1597  * Attempt to start streaming. When this function is called there must be
1598  * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1599  * number of buffers required for the DMA engine to function). If the
1600  * @start_streaming op fails it is supposed to return all the driver-owned
1601  * buffers back to vb2 in state QUEUED. Check if that happened and if
1602  * not warn and reclaim them forcefully.
1603  */
1604 static int vb2_start_streaming(struct vb2_queue *q)
1605 {
1606         struct vb2_buffer *vb;
1607         int ret;
1608
1609         /*
1610          * If any buffers were queued before streamon,
1611          * we can now pass them to driver for processing.
1612          */
1613         list_for_each_entry(vb, &q->queued_list, queued_entry)
1614                 __enqueue_in_driver(vb);
1615
1616         /* Tell the driver to start streaming */
1617         q->start_streaming_called = 1;
1618         ret = call_qop(q, start_streaming, q,
1619                        atomic_read(&q->owned_by_drv_count));
1620         if (!ret)
1621                 return 0;
1622
1623         q->start_streaming_called = 0;
1624
1625         dprintk(q, 1, "driver refused to start streaming\n");
1626         /*
1627          * If you see this warning, then the driver isn't cleaning up properly
1628          * after a failed start_streaming(). See the start_streaming()
1629          * documentation in videobuf2-core.h for more information how buffers
1630          * should be returned to vb2 in start_streaming().
1631          */
1632         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1633                 unsigned i;
1634
1635                 /*
1636                  * Forcefully reclaim buffers if the driver did not
1637                  * correctly return them to vb2.
1638                  */
1639                 for (i = 0; i < q->num_buffers; ++i) {
1640                         vb = q->bufs[i];
1641                         if (vb->state == VB2_BUF_STATE_ACTIVE)
1642                                 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1643                 }
1644                 /* Must be zero now */
1645                 WARN_ON(atomic_read(&q->owned_by_drv_count));
1646         }
1647         /*
1648          * If done_list is not empty, then start_streaming() didn't call
1649          * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1650          * STATE_DONE.
1651          */
1652         WARN_ON(!list_empty(&q->done_list));
1653         return ret;
1654 }
1655
1656 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1657                   struct media_request *req)
1658 {
1659         struct vb2_buffer *vb;
1660         enum vb2_buffer_state orig_state;
1661         int ret;
1662
1663         if (q->error) {
1664                 dprintk(q, 1, "fatal error occurred on queue\n");
1665                 return -EIO;
1666         }
1667
1668         vb = q->bufs[index];
1669
1670         if (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1671             q->requires_requests) {
1672                 dprintk(q, 1, "qbuf requires a request\n");
1673                 return -EBADR;
1674         }
1675
1676         if ((req && q->uses_qbuf) ||
1677             (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1678              q->uses_requests)) {
1679                 dprintk(q, 1, "queue in wrong mode (qbuf vs requests)\n");
1680                 return -EBUSY;
1681         }
1682
1683         if (req) {
1684                 int ret;
1685
1686                 q->uses_requests = 1;
1687                 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1688                         dprintk(q, 1, "buffer %d not in dequeued state\n",
1689                                 vb->index);
1690                         return -EINVAL;
1691                 }
1692
1693                 if (q->is_output && !vb->prepared) {
1694                         ret = call_vb_qop(vb, buf_out_validate, vb);
1695                         if (ret) {
1696                                 dprintk(q, 1, "buffer validation failed\n");
1697                                 return ret;
1698                         }
1699                 }
1700
1701                 media_request_object_init(&vb->req_obj);
1702
1703                 /* Make sure the request is in a safe state for updating. */
1704                 ret = media_request_lock_for_update(req);
1705                 if (ret)
1706                         return ret;
1707                 ret = media_request_object_bind(req, &vb2_core_req_ops,
1708                                                 q, true, &vb->req_obj);
1709                 media_request_unlock_for_update(req);
1710                 if (ret)
1711                         return ret;
1712
1713                 vb->state = VB2_BUF_STATE_IN_REQUEST;
1714
1715                 /*
1716                  * Increment the refcount and store the request.
1717                  * The request refcount is decremented again when the
1718                  * buffer is dequeued. This is to prevent vb2_buffer_done()
1719                  * from freeing the request from interrupt context, which can
1720                  * happen if the application closed the request fd after
1721                  * queueing the request.
1722                  */
1723                 media_request_get(req);
1724                 vb->request = req;
1725
1726                 /* Fill buffer information for the userspace */
1727                 if (pb) {
1728                         call_void_bufop(q, copy_timestamp, vb, pb);
1729                         call_void_bufop(q, fill_user_buffer, vb, pb);
1730                 }
1731
1732                 dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
1733                 return 0;
1734         }
1735
1736         if (vb->state != VB2_BUF_STATE_IN_REQUEST)
1737                 q->uses_qbuf = 1;
1738
1739         switch (vb->state) {
1740         case VB2_BUF_STATE_DEQUEUED:
1741         case VB2_BUF_STATE_IN_REQUEST:
1742                 if (!vb->prepared) {
1743                         ret = __buf_prepare(vb);
1744                         if (ret)
1745                                 return ret;
1746                 }
1747                 break;
1748         case VB2_BUF_STATE_PREPARING:
1749                 dprintk(q, 1, "buffer still being prepared\n");
1750                 return -EINVAL;
1751         default:
1752                 dprintk(q, 1, "invalid buffer state %s\n",
1753                         vb2_state_name(vb->state));
1754                 return -EINVAL;
1755         }
1756
1757         /*
1758          * Add to the queued buffers list, a buffer will stay on it until
1759          * dequeued in dqbuf.
1760          */
1761         orig_state = vb->state;
1762         list_add_tail(&vb->queued_entry, &q->queued_list);
1763         q->queued_count++;
1764         q->waiting_for_buffers = false;
1765         vb->state = VB2_BUF_STATE_QUEUED;
1766
1767         if (pb)
1768                 call_void_bufop(q, copy_timestamp, vb, pb);
1769
1770         trace_vb2_qbuf(q, vb);
1771
1772         /*
1773          * If already streaming, give the buffer to driver for processing.
1774          * If not, the buffer will be given to driver on next streamon.
1775          */
1776         if (q->start_streaming_called)
1777                 __enqueue_in_driver(vb);
1778
1779         /* Fill buffer information for the userspace */
1780         if (pb)
1781                 call_void_bufop(q, fill_user_buffer, vb, pb);
1782
1783         /*
1784          * If streamon has been called, and we haven't yet called
1785          * start_streaming() since not enough buffers were queued, and
1786          * we now have reached the minimum number of queued buffers,
1787          * then we can finally call start_streaming().
1788          */
1789         if (q->streaming && !q->start_streaming_called &&
1790             q->queued_count >= q->min_buffers_needed) {
1791                 ret = vb2_start_streaming(q);
1792                 if (ret) {
1793                         /*
1794                          * Since vb2_core_qbuf will return with an error,
1795                          * we should return it to state DEQUEUED since
1796                          * the error indicates that the buffer wasn't queued.
1797                          */
1798                         list_del(&vb->queued_entry);
1799                         q->queued_count--;
1800                         vb->state = orig_state;
1801                         return ret;
1802                 }
1803         }
1804
1805         dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
1806         return 0;
1807 }
1808 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1809
1810 /*
1811  * __vb2_wait_for_done_vb() - wait for a buffer to become available
1812  * for dequeuing
1813  *
1814  * Will sleep if required for nonblocking == false.
1815  */
1816 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1817 {
1818         /*
1819          * All operations on vb_done_list are performed under done_lock
1820          * spinlock protection. However, buffers may be removed from
1821          * it and returned to userspace only while holding both driver's
1822          * lock and the done_lock spinlock. Thus we can be sure that as
1823          * long as we hold the driver's lock, the list will remain not
1824          * empty if list_empty() check succeeds.
1825          */
1826
1827         for (;;) {
1828                 int ret;
1829
1830                 if (q->waiting_in_dqbuf) {
1831                         dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
1832                         return -EBUSY;
1833                 }
1834
1835                 if (!q->streaming) {
1836                         dprintk(q, 1, "streaming off, will not wait for buffers\n");
1837                         return -EINVAL;
1838                 }
1839
1840                 if (q->error) {
1841                         dprintk(q, 1, "Queue in error state, will not wait for buffers\n");
1842                         return -EIO;
1843                 }
1844
1845                 if (q->last_buffer_dequeued) {
1846                         dprintk(q, 3, "last buffer dequeued already, will not wait for buffers\n");
1847                         return -EPIPE;
1848                 }
1849
1850                 if (!list_empty(&q->done_list)) {
1851                         /*
1852                          * Found a buffer that we were waiting for.
1853                          */
1854                         break;
1855                 }
1856
1857                 if (nonblocking) {
1858                         dprintk(q, 3, "nonblocking and no buffers to dequeue, will not wait\n");
1859                         return -EAGAIN;
1860                 }
1861
1862                 q->waiting_in_dqbuf = 1;
1863                 /*
1864                  * We are streaming and blocking, wait for another buffer to
1865                  * become ready or for streamoff. Driver's lock is released to
1866                  * allow streamoff or qbuf to be called while waiting.
1867                  */
1868                 call_void_qop(q, wait_prepare, q);
1869
1870                 /*
1871                  * All locks have been released, it is safe to sleep now.
1872                  */
1873                 dprintk(q, 3, "will sleep waiting for buffers\n");
1874                 ret = wait_event_interruptible(q->done_wq,
1875                                 !list_empty(&q->done_list) || !q->streaming ||
1876                                 q->error);
1877
1878                 /*
1879                  * We need to reevaluate both conditions again after reacquiring
1880                  * the locks or return an error if one occurred.
1881                  */
1882                 call_void_qop(q, wait_finish, q);
1883                 q->waiting_in_dqbuf = 0;
1884                 if (ret) {
1885                         dprintk(q, 1, "sleep was interrupted\n");
1886                         return ret;
1887                 }
1888         }
1889         return 0;
1890 }
1891
1892 /*
1893  * __vb2_get_done_vb() - get a buffer ready for dequeuing
1894  *
1895  * Will sleep if required for nonblocking == false.
1896  */
1897 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1898                              void *pb, int nonblocking)
1899 {
1900         unsigned long flags;
1901         int ret = 0;
1902
1903         /*
1904          * Wait for at least one buffer to become available on the done_list.
1905          */
1906         ret = __vb2_wait_for_done_vb(q, nonblocking);
1907         if (ret)
1908                 return ret;
1909
1910         /*
1911          * Driver's lock has been held since we last verified that done_list
1912          * is not empty, so no need for another list_empty(done_list) check.
1913          */
1914         spin_lock_irqsave(&q->done_lock, flags);
1915         *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1916         /*
1917          * Only remove the buffer from done_list if all planes can be
1918          * handled. Some cases such as V4L2 file I/O and DVB have pb
1919          * == NULL; skip the check then as there's nothing to verify.
1920          */
1921         if (pb)
1922                 ret = call_bufop(q, verify_planes_array, *vb, pb);
1923         if (!ret)
1924                 list_del(&(*vb)->done_entry);
1925         spin_unlock_irqrestore(&q->done_lock, flags);
1926
1927         return ret;
1928 }
1929
1930 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1931 {
1932         if (!q->streaming) {
1933                 dprintk(q, 1, "streaming off, will not wait for buffers\n");
1934                 return -EINVAL;
1935         }
1936
1937         if (q->start_streaming_called)
1938                 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1939         return 0;
1940 }
1941 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1942
1943 /*
1944  * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1945  */
1946 static void __vb2_dqbuf(struct vb2_buffer *vb)
1947 {
1948         struct vb2_queue *q = vb->vb2_queue;
1949
1950         /* nothing to do if the buffer is already dequeued */
1951         if (vb->state == VB2_BUF_STATE_DEQUEUED)
1952                 return;
1953
1954         vb->state = VB2_BUF_STATE_DEQUEUED;
1955
1956         call_void_bufop(q, init_buffer, vb);
1957 }
1958
1959 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1960                    bool nonblocking)
1961 {
1962         struct vb2_buffer *vb = NULL;
1963         int ret;
1964
1965         ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1966         if (ret < 0)
1967                 return ret;
1968
1969         switch (vb->state) {
1970         case VB2_BUF_STATE_DONE:
1971                 dprintk(q, 3, "returning done buffer\n");
1972                 break;
1973         case VB2_BUF_STATE_ERROR:
1974                 dprintk(q, 3, "returning done buffer with errors\n");
1975                 break;
1976         default:
1977                 dprintk(q, 1, "invalid buffer state %s\n",
1978                         vb2_state_name(vb->state));
1979                 return -EINVAL;
1980         }
1981
1982         call_void_vb_qop(vb, buf_finish, vb);
1983         vb->prepared = 0;
1984
1985         if (pindex)
1986                 *pindex = vb->index;
1987
1988         /* Fill buffer information for the userspace */
1989         if (pb)
1990                 call_void_bufop(q, fill_user_buffer, vb, pb);
1991
1992         /* Remove from vb2 queue */
1993         list_del(&vb->queued_entry);
1994         q->queued_count--;
1995
1996         trace_vb2_dqbuf(q, vb);
1997
1998         /* go back to dequeued state */
1999         __vb2_dqbuf(vb);
2000
2001         if (WARN_ON(vb->req_obj.req)) {
2002                 media_request_object_unbind(&vb->req_obj);
2003                 media_request_object_put(&vb->req_obj);
2004         }
2005         if (vb->request)
2006                 media_request_put(vb->request);
2007         vb->request = NULL;
2008
2009         dprintk(q, 2, "dqbuf of buffer %d, state: %s\n",
2010                 vb->index, vb2_state_name(vb->state));
2011
2012         return 0;
2013
2014 }
2015 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
2016
2017 /*
2018  * __vb2_queue_cancel() - cancel and stop (pause) streaming
2019  *
2020  * Removes all queued buffers from driver's queue and all buffers queued by
2021  * userspace from vb2's queue. Returns to state after reqbufs.
2022  */
2023 static void __vb2_queue_cancel(struct vb2_queue *q)
2024 {
2025         unsigned int i;
2026
2027         /*
2028          * Tell driver to stop all transactions and release all queued
2029          * buffers.
2030          */
2031         if (q->start_streaming_called)
2032                 call_void_qop(q, stop_streaming, q);
2033
2034         if (q->streaming)
2035                 call_void_qop(q, unprepare_streaming, q);
2036
2037         /*
2038          * If you see this warning, then the driver isn't cleaning up properly
2039          * in stop_streaming(). See the stop_streaming() documentation in
2040          * videobuf2-core.h for more information how buffers should be returned
2041          * to vb2 in stop_streaming().
2042          */
2043         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
2044                 for (i = 0; i < q->num_buffers; ++i)
2045                         if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE) {
2046                                 pr_warn("driver bug: stop_streaming operation is leaving buf %p in active state\n",
2047                                         q->bufs[i]);
2048                                 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
2049                         }
2050                 /* Must be zero now */
2051                 WARN_ON(atomic_read(&q->owned_by_drv_count));
2052         }
2053
2054         q->streaming = 0;
2055         q->start_streaming_called = 0;
2056         q->queued_count = 0;
2057         q->error = 0;
2058         q->uses_requests = 0;
2059         q->uses_qbuf = 0;
2060
2061         /*
2062          * Remove all buffers from vb2's list...
2063          */
2064         INIT_LIST_HEAD(&q->queued_list);
2065         /*
2066          * ...and done list; userspace will not receive any buffers it
2067          * has not already dequeued before initiating cancel.
2068          */
2069         INIT_LIST_HEAD(&q->done_list);
2070         atomic_set(&q->owned_by_drv_count, 0);
2071         wake_up_all(&q->done_wq);
2072
2073         /*
2074          * Reinitialize all buffers for next use.
2075          * Make sure to call buf_finish for any queued buffers. Normally
2076          * that's done in dqbuf, but that's not going to happen when we
2077          * cancel the whole queue. Note: this code belongs here, not in
2078          * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
2079          * call to __fill_user_buffer() after buf_finish(). That order can't
2080          * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2081          */
2082         for (i = 0; i < q->num_buffers; ++i) {
2083                 struct vb2_buffer *vb = q->bufs[i];
2084                 struct media_request *req = vb->req_obj.req;
2085
2086                 /*
2087                  * If a request is associated with this buffer, then
2088                  * call buf_request_cancel() to give the driver to complete()
2089                  * related request objects. Otherwise those objects would
2090                  * never complete.
2091                  */
2092                 if (req) {
2093                         enum media_request_state state;
2094                         unsigned long flags;
2095
2096                         spin_lock_irqsave(&req->lock, flags);
2097                         state = req->state;
2098                         spin_unlock_irqrestore(&req->lock, flags);
2099
2100                         if (state == MEDIA_REQUEST_STATE_QUEUED)
2101                                 call_void_vb_qop(vb, buf_request_complete, vb);
2102                 }
2103
2104                 __vb2_buf_mem_finish(vb);
2105
2106                 if (vb->prepared) {
2107                         call_void_vb_qop(vb, buf_finish, vb);
2108                         vb->prepared = 0;
2109                 }
2110                 __vb2_dqbuf(vb);
2111
2112                 if (vb->req_obj.req) {
2113                         media_request_object_unbind(&vb->req_obj);
2114                         media_request_object_put(&vb->req_obj);
2115                 }
2116                 if (vb->request)
2117                         media_request_put(vb->request);
2118                 vb->request = NULL;
2119                 vb->copied_timestamp = 0;
2120         }
2121 }
2122
2123 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
2124 {
2125         int ret;
2126
2127         if (type != q->type) {
2128                 dprintk(q, 1, "invalid stream type\n");
2129                 return -EINVAL;
2130         }
2131
2132         if (q->streaming) {
2133                 dprintk(q, 3, "already streaming\n");
2134                 return 0;
2135         }
2136
2137         if (!q->num_buffers) {
2138                 dprintk(q, 1, "no buffers have been allocated\n");
2139                 return -EINVAL;
2140         }
2141
2142         if (q->num_buffers < q->min_buffers_needed) {
2143                 dprintk(q, 1, "need at least %u allocated buffers\n",
2144                                 q->min_buffers_needed);
2145                 return -EINVAL;
2146         }
2147
2148         ret = call_qop(q, prepare_streaming, q);
2149         if (ret)
2150                 return ret;
2151
2152         /*
2153          * Tell driver to start streaming provided sufficient buffers
2154          * are available.
2155          */
2156         if (q->queued_count >= q->min_buffers_needed) {
2157                 ret = vb2_start_streaming(q);
2158                 if (ret)
2159                         goto unprepare;
2160         }
2161
2162         q->streaming = 1;
2163
2164         dprintk(q, 3, "successful\n");
2165         return 0;
2166
2167 unprepare:
2168         call_void_qop(q, unprepare_streaming, q);
2169         return ret;
2170 }
2171 EXPORT_SYMBOL_GPL(vb2_core_streamon);
2172
2173 void vb2_queue_error(struct vb2_queue *q)
2174 {
2175         q->error = 1;
2176
2177         wake_up_all(&q->done_wq);
2178 }
2179 EXPORT_SYMBOL_GPL(vb2_queue_error);
2180
2181 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
2182 {
2183         if (type != q->type) {
2184                 dprintk(q, 1, "invalid stream type\n");
2185                 return -EINVAL;
2186         }
2187
2188         /*
2189          * Cancel will pause streaming and remove all buffers from the driver
2190          * and vb2, effectively returning control over them to userspace.
2191          *
2192          * Note that we do this even if q->streaming == 0: if you prepare or
2193          * queue buffers, and then call streamoff without ever having called
2194          * streamon, you would still expect those buffers to be returned to
2195          * their normal dequeued state.
2196          */
2197         __vb2_queue_cancel(q);
2198         q->waiting_for_buffers = !q->is_output;
2199         q->last_buffer_dequeued = false;
2200
2201         dprintk(q, 3, "successful\n");
2202         return 0;
2203 }
2204 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
2205
2206 /*
2207  * __find_plane_by_offset() - find plane associated with the given offset off
2208  */
2209 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2210                         unsigned int *_buffer, unsigned int *_plane)
2211 {
2212         struct vb2_buffer *vb;
2213         unsigned int buffer, plane;
2214
2215         /*
2216          * Sanity checks to ensure the lock is held, MEMORY_MMAP is
2217          * used and fileio isn't active.
2218          */
2219         lockdep_assert_held(&q->mmap_lock);
2220
2221         if (q->memory != VB2_MEMORY_MMAP) {
2222                 dprintk(q, 1, "queue is not currently set up for mmap\n");
2223                 return -EINVAL;
2224         }
2225
2226         if (vb2_fileio_is_active(q)) {
2227                 dprintk(q, 1, "file io in progress\n");
2228                 return -EBUSY;
2229         }
2230
2231         /*
2232          * Go over all buffers and their planes, comparing the given offset
2233          * with an offset assigned to each plane. If a match is found,
2234          * return its buffer and plane numbers.
2235          */
2236         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2237                 vb = q->bufs[buffer];
2238
2239                 for (plane = 0; plane < vb->num_planes; ++plane) {
2240                         if (vb->planes[plane].m.offset == off) {
2241                                 *_buffer = buffer;
2242                                 *_plane = plane;
2243                                 return 0;
2244                         }
2245                 }
2246         }
2247
2248         return -EINVAL;
2249 }
2250
2251 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
2252                 unsigned int index, unsigned int plane, unsigned int flags)
2253 {
2254         struct vb2_buffer *vb = NULL;
2255         struct vb2_plane *vb_plane;
2256         int ret;
2257         struct dma_buf *dbuf;
2258
2259         if (q->memory != VB2_MEMORY_MMAP) {
2260                 dprintk(q, 1, "queue is not currently set up for mmap\n");
2261                 return -EINVAL;
2262         }
2263
2264         if (!q->mem_ops->get_dmabuf) {
2265                 dprintk(q, 1, "queue does not support DMA buffer exporting\n");
2266                 return -EINVAL;
2267         }
2268
2269         if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
2270                 dprintk(q, 1, "queue does support only O_CLOEXEC and access mode flags\n");
2271                 return -EINVAL;
2272         }
2273
2274         if (type != q->type) {
2275                 dprintk(q, 1, "invalid buffer type\n");
2276                 return -EINVAL;
2277         }
2278
2279         if (index >= q->num_buffers) {
2280                 dprintk(q, 1, "buffer index out of range\n");
2281                 return -EINVAL;
2282         }
2283
2284         vb = q->bufs[index];
2285
2286         if (plane >= vb->num_planes) {
2287                 dprintk(q, 1, "buffer plane out of range\n");
2288                 return -EINVAL;
2289         }
2290
2291         if (vb2_fileio_is_active(q)) {
2292                 dprintk(q, 1, "expbuf: file io in progress\n");
2293                 return -EBUSY;
2294         }
2295
2296         vb_plane = &vb->planes[plane];
2297
2298         dbuf = call_ptr_memop(get_dmabuf,
2299                               vb,
2300                               vb_plane->mem_priv,
2301                               flags & O_ACCMODE);
2302         if (IS_ERR_OR_NULL(dbuf)) {
2303                 dprintk(q, 1, "failed to export buffer %d, plane %d\n",
2304                         index, plane);
2305                 return -EINVAL;
2306         }
2307
2308         ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
2309         if (ret < 0) {
2310                 dprintk(q, 3, "buffer %d, plane %d failed to export (%d)\n",
2311                         index, plane, ret);
2312                 dma_buf_put(dbuf);
2313                 return ret;
2314         }
2315
2316         dprintk(q, 3, "buffer %d, plane %d exported as %d descriptor\n",
2317                 index, plane, ret);
2318         *fd = ret;
2319
2320         return 0;
2321 }
2322 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
2323
2324 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2325 {
2326         unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2327         struct vb2_buffer *vb;
2328         unsigned int buffer = 0, plane = 0;
2329         int ret;
2330         unsigned long length;
2331
2332         /*
2333          * Check memory area access mode.
2334          */
2335         if (!(vma->vm_flags & VM_SHARED)) {
2336                 dprintk(q, 1, "invalid vma flags, VM_SHARED needed\n");
2337                 return -EINVAL;
2338         }
2339         if (q->is_output) {
2340                 if (!(vma->vm_flags & VM_WRITE)) {
2341                         dprintk(q, 1, "invalid vma flags, VM_WRITE needed\n");
2342                         return -EINVAL;
2343                 }
2344         } else {
2345                 if (!(vma->vm_flags & VM_READ)) {
2346                         dprintk(q, 1, "invalid vma flags, VM_READ needed\n");
2347                         return -EINVAL;
2348                 }
2349         }
2350
2351         mutex_lock(&q->mmap_lock);
2352
2353         /*
2354          * Find the plane corresponding to the offset passed by userspace. This
2355          * will return an error if not MEMORY_MMAP or file I/O is in progress.
2356          */
2357         ret = __find_plane_by_offset(q, off, &buffer, &plane);
2358         if (ret)
2359                 goto unlock;
2360
2361         vb = q->bufs[buffer];
2362
2363         /*
2364          * MMAP requires page_aligned buffers.
2365          * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2366          * so, we need to do the same here.
2367          */
2368         length = PAGE_ALIGN(vb->planes[plane].length);
2369         if (length < (vma->vm_end - vma->vm_start)) {
2370                 dprintk(q, 1,
2371                         "MMAP invalid, as it would overflow buffer length\n");
2372                 ret = -EINVAL;
2373                 goto unlock;
2374         }
2375
2376         /*
2377          * vm_pgoff is treated in V4L2 API as a 'cookie' to select a buffer,
2378          * not as a in-buffer offset. We always want to mmap a whole buffer
2379          * from its beginning.
2380          */
2381         vma->vm_pgoff = 0;
2382
2383         ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2384
2385 unlock:
2386         mutex_unlock(&q->mmap_lock);
2387         if (ret)
2388                 return ret;
2389
2390         dprintk(q, 3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2391         return 0;
2392 }
2393 EXPORT_SYMBOL_GPL(vb2_mmap);
2394
2395 #ifndef CONFIG_MMU
2396 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2397                                     unsigned long addr,
2398                                     unsigned long len,
2399                                     unsigned long pgoff,
2400                                     unsigned long flags)
2401 {
2402         unsigned long off = pgoff << PAGE_SHIFT;
2403         struct vb2_buffer *vb;
2404         unsigned int buffer, plane;
2405         void *vaddr;
2406         int ret;
2407
2408         mutex_lock(&q->mmap_lock);
2409
2410         /*
2411          * Find the plane corresponding to the offset passed by userspace. This
2412          * will return an error if not MEMORY_MMAP or file I/O is in progress.
2413          */
2414         ret = __find_plane_by_offset(q, off, &buffer, &plane);
2415         if (ret)
2416                 goto unlock;
2417
2418         vb = q->bufs[buffer];
2419
2420         vaddr = vb2_plane_vaddr(vb, plane);
2421         mutex_unlock(&q->mmap_lock);
2422         return vaddr ? (unsigned long)vaddr : -EINVAL;
2423
2424 unlock:
2425         mutex_unlock(&q->mmap_lock);
2426         return ret;
2427 }
2428 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2429 #endif
2430
2431 int vb2_core_queue_init(struct vb2_queue *q)
2432 {
2433         /*
2434          * Sanity check
2435          */
2436         if (WARN_ON(!q)                   ||
2437             WARN_ON(!q->ops)              ||
2438             WARN_ON(!q->mem_ops)          ||
2439             WARN_ON(!q->type)             ||
2440             WARN_ON(!q->io_modes)         ||
2441             WARN_ON(!q->ops->queue_setup) ||
2442             WARN_ON(!q->ops->buf_queue))
2443                 return -EINVAL;
2444
2445         if (WARN_ON(q->requires_requests && !q->supports_requests))
2446                 return -EINVAL;
2447
2448         /*
2449          * This combination is not allowed since a non-zero value of
2450          * q->min_buffers_needed can cause vb2_core_qbuf() to fail if
2451          * it has to call start_streaming(), and the Request API expects
2452          * that queueing a request (and thus queueing a buffer contained
2453          * in that request) will always succeed. There is no method of
2454          * propagating an error back to userspace.
2455          */
2456         if (WARN_ON(q->supports_requests && q->min_buffers_needed))
2457                 return -EINVAL;
2458
2459         INIT_LIST_HEAD(&q->queued_list);
2460         INIT_LIST_HEAD(&q->done_list);
2461         spin_lock_init(&q->done_lock);
2462         mutex_init(&q->mmap_lock);
2463         init_waitqueue_head(&q->done_wq);
2464
2465         q->memory = VB2_MEMORY_UNKNOWN;
2466
2467         if (q->buf_struct_size == 0)
2468                 q->buf_struct_size = sizeof(struct vb2_buffer);
2469
2470         if (q->bidirectional)
2471                 q->dma_dir = DMA_BIDIRECTIONAL;
2472         else
2473                 q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
2474
2475         if (q->name[0] == '\0')
2476                 snprintf(q->name, sizeof(q->name), "%s-%p",
2477                          q->is_output ? "out" : "cap", q);
2478
2479         return 0;
2480 }
2481 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2482
2483 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2484 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2485 void vb2_core_queue_release(struct vb2_queue *q)
2486 {
2487         __vb2_cleanup_fileio(q);
2488         __vb2_queue_cancel(q);
2489         mutex_lock(&q->mmap_lock);
2490         __vb2_queue_free(q, q->num_buffers);
2491         mutex_unlock(&q->mmap_lock);
2492 }
2493 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2494
2495 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
2496                 poll_table *wait)
2497 {
2498         __poll_t req_events = poll_requested_events(wait);
2499         struct vb2_buffer *vb = NULL;
2500         unsigned long flags;
2501
2502         /*
2503          * poll_wait() MUST be called on the first invocation on all the
2504          * potential queues of interest, even if we are not interested in their
2505          * events during this first call. Failure to do so will result in
2506          * queue's events to be ignored because the poll_table won't be capable
2507          * of adding new wait queues thereafter.
2508          */
2509         poll_wait(file, &q->done_wq, wait);
2510
2511         if (!q->is_output && !(req_events & (EPOLLIN | EPOLLRDNORM)))
2512                 return 0;
2513         if (q->is_output && !(req_events & (EPOLLOUT | EPOLLWRNORM)))
2514                 return 0;
2515
2516         /*
2517          * Start file I/O emulator only if streaming API has not been used yet.
2518          */
2519         if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2520                 if (!q->is_output && (q->io_modes & VB2_READ) &&
2521                                 (req_events & (EPOLLIN | EPOLLRDNORM))) {
2522                         if (__vb2_init_fileio(q, 1))
2523                                 return EPOLLERR;
2524                 }
2525                 if (q->is_output && (q->io_modes & VB2_WRITE) &&
2526                                 (req_events & (EPOLLOUT | EPOLLWRNORM))) {
2527                         if (__vb2_init_fileio(q, 0))
2528                                 return EPOLLERR;
2529                         /*
2530                          * Write to OUTPUT queue can be done immediately.
2531                          */
2532                         return EPOLLOUT | EPOLLWRNORM;
2533                 }
2534         }
2535
2536         /*
2537          * There is nothing to wait for if the queue isn't streaming, or if the
2538          * error flag is set.
2539          */
2540         if (!vb2_is_streaming(q) || q->error)
2541                 return EPOLLERR;
2542
2543         /*
2544          * If this quirk is set and QBUF hasn't been called yet then
2545          * return EPOLLERR as well. This only affects capture queues, output
2546          * queues will always initialize waiting_for_buffers to false.
2547          * This quirk is set by V4L2 for backwards compatibility reasons.
2548          */
2549         if (q->quirk_poll_must_check_waiting_for_buffers &&
2550             q->waiting_for_buffers && (req_events & (EPOLLIN | EPOLLRDNORM)))
2551                 return EPOLLERR;
2552
2553         /*
2554          * For output streams you can call write() as long as there are fewer
2555          * buffers queued than there are buffers available.
2556          */
2557         if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2558                 return EPOLLOUT | EPOLLWRNORM;
2559
2560         if (list_empty(&q->done_list)) {
2561                 /*
2562                  * If the last buffer was dequeued from a capture queue,
2563                  * return immediately. DQBUF will return -EPIPE.
2564                  */
2565                 if (q->last_buffer_dequeued)
2566                         return EPOLLIN | EPOLLRDNORM;
2567         }
2568
2569         /*
2570          * Take first buffer available for dequeuing.
2571          */
2572         spin_lock_irqsave(&q->done_lock, flags);
2573         if (!list_empty(&q->done_list))
2574                 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2575                                         done_entry);
2576         spin_unlock_irqrestore(&q->done_lock, flags);
2577
2578         if (vb && (vb->state == VB2_BUF_STATE_DONE
2579                         || vb->state == VB2_BUF_STATE_ERROR)) {
2580                 return (q->is_output) ?
2581                                 EPOLLOUT | EPOLLWRNORM :
2582                                 EPOLLIN | EPOLLRDNORM;
2583         }
2584         return 0;
2585 }
2586 EXPORT_SYMBOL_GPL(vb2_core_poll);
2587
2588 /*
2589  * struct vb2_fileio_buf - buffer context used by file io emulator
2590  *
2591  * vb2 provides a compatibility layer and emulator of file io (read and
2592  * write) calls on top of streaming API. This structure is used for
2593  * tracking context related to the buffers.
2594  */
2595 struct vb2_fileio_buf {
2596         void *vaddr;
2597         unsigned int size;
2598         unsigned int pos;
2599         unsigned int queued:1;
2600 };
2601
2602 /*
2603  * struct vb2_fileio_data - queue context used by file io emulator
2604  *
2605  * @cur_index:  the index of the buffer currently being read from or
2606  *              written to. If equal to q->num_buffers then a new buffer
2607  *              must be dequeued.
2608  * @initial_index: in the read() case all buffers are queued up immediately
2609  *              in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2610  *              buffers. However, in the write() case no buffers are initially
2611  *              queued, instead whenever a buffer is full it is queued up by
2612  *              __vb2_perform_fileio(). Only once all available buffers have
2613  *              been queued up will __vb2_perform_fileio() start to dequeue
2614  *              buffers. This means that initially __vb2_perform_fileio()
2615  *              needs to know what buffer index to use when it is queuing up
2616  *              the buffers for the first time. That initial index is stored
2617  *              in this field. Once it is equal to q->num_buffers all
2618  *              available buffers have been queued and __vb2_perform_fileio()
2619  *              should start the normal dequeue/queue cycle.
2620  *
2621  * vb2 provides a compatibility layer and emulator of file io (read and
2622  * write) calls on top of streaming API. For proper operation it required
2623  * this structure to save the driver state between each call of the read
2624  * or write function.
2625  */
2626 struct vb2_fileio_data {
2627         unsigned int count;
2628         unsigned int type;
2629         unsigned int memory;
2630         struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2631         unsigned int cur_index;
2632         unsigned int initial_index;
2633         unsigned int q_count;
2634         unsigned int dq_count;
2635         unsigned read_once:1;
2636         unsigned write_immediately:1;
2637 };
2638
2639 /*
2640  * __vb2_init_fileio() - initialize file io emulator
2641  * @q:          videobuf2 queue
2642  * @read:       mode selector (1 means read, 0 means write)
2643  */
2644 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2645 {
2646         struct vb2_fileio_data *fileio;
2647         int i, ret;
2648         unsigned int count = 0;
2649
2650         /*
2651          * Sanity check
2652          */
2653         if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2654                     (!read && !(q->io_modes & VB2_WRITE))))
2655                 return -EINVAL;
2656
2657         /*
2658          * Check if device supports mapping buffers to kernel virtual space.
2659          */
2660         if (!q->mem_ops->vaddr)
2661                 return -EBUSY;
2662
2663         /*
2664          * Check if streaming api has not been already activated.
2665          */
2666         if (q->streaming || q->num_buffers > 0)
2667                 return -EBUSY;
2668
2669         /*
2670          * Start with count 1, driver can increase it in queue_setup()
2671          */
2672         count = 1;
2673
2674         dprintk(q, 3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2675                 (read) ? "read" : "write", count, q->fileio_read_once,
2676                 q->fileio_write_immediately);
2677
2678         fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2679         if (fileio == NULL)
2680                 return -ENOMEM;
2681
2682         fileio->read_once = q->fileio_read_once;
2683         fileio->write_immediately = q->fileio_write_immediately;
2684
2685         /*
2686          * Request buffers and use MMAP type to force driver
2687          * to allocate buffers by itself.
2688          */
2689         fileio->count = count;
2690         fileio->memory = VB2_MEMORY_MMAP;
2691         fileio->type = q->type;
2692         q->fileio = fileio;
2693         ret = vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
2694         if (ret)
2695                 goto err_kfree;
2696
2697         /*
2698          * Check if plane_count is correct
2699          * (multiplane buffers are not supported).
2700          */
2701         if (q->bufs[0]->num_planes != 1) {
2702                 ret = -EBUSY;
2703                 goto err_reqbufs;
2704         }
2705
2706         /*
2707          * Get kernel address of each buffer.
2708          */
2709         for (i = 0; i < q->num_buffers; i++) {
2710                 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2711                 if (fileio->bufs[i].vaddr == NULL) {
2712                         ret = -EINVAL;
2713                         goto err_reqbufs;
2714                 }
2715                 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2716         }
2717
2718         /*
2719          * Read mode requires pre queuing of all buffers.
2720          */
2721         if (read) {
2722                 /*
2723                  * Queue all buffers.
2724                  */
2725                 for (i = 0; i < q->num_buffers; i++) {
2726                         ret = vb2_core_qbuf(q, i, NULL, NULL);
2727                         if (ret)
2728                                 goto err_reqbufs;
2729                         fileio->bufs[i].queued = 1;
2730                 }
2731                 /*
2732                  * All buffers have been queued, so mark that by setting
2733                  * initial_index to q->num_buffers
2734                  */
2735                 fileio->initial_index = q->num_buffers;
2736                 fileio->cur_index = q->num_buffers;
2737         }
2738
2739         /*
2740          * Start streaming.
2741          */
2742         ret = vb2_core_streamon(q, q->type);
2743         if (ret)
2744                 goto err_reqbufs;
2745
2746         return ret;
2747
2748 err_reqbufs:
2749         fileio->count = 0;
2750         vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
2751
2752 err_kfree:
2753         q->fileio = NULL;
2754         kfree(fileio);
2755         return ret;
2756 }
2757
2758 /*
2759  * __vb2_cleanup_fileio() - free resourced used by file io emulator
2760  * @q:          videobuf2 queue
2761  */
2762 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2763 {
2764         struct vb2_fileio_data *fileio = q->fileio;
2765
2766         if (fileio) {
2767                 vb2_core_streamoff(q, q->type);
2768                 q->fileio = NULL;
2769                 fileio->count = 0;
2770                 vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
2771                 kfree(fileio);
2772                 dprintk(q, 3, "file io emulator closed\n");
2773         }
2774         return 0;
2775 }
2776
2777 /*
2778  * __vb2_perform_fileio() - perform a single file io (read or write) operation
2779  * @q:          videobuf2 queue
2780  * @data:       pointed to target userspace buffer
2781  * @count:      number of bytes to read or write
2782  * @ppos:       file handle position tracking pointer
2783  * @nonblock:   mode selector (1 means blocking calls, 0 means nonblocking)
2784  * @read:       access mode selector (1 means read, 0 means write)
2785  */
2786 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2787                 loff_t *ppos, int nonblock, int read)
2788 {
2789         struct vb2_fileio_data *fileio;
2790         struct vb2_fileio_buf *buf;
2791         bool is_multiplanar = q->is_multiplanar;
2792         /*
2793          * When using write() to write data to an output video node the vb2 core
2794          * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2795          * else is able to provide this information with the write() operation.
2796          */
2797         bool copy_timestamp = !read && q->copy_timestamp;
2798         unsigned index;
2799         int ret;
2800
2801         dprintk(q, 3, "mode %s, offset %ld, count %zd, %sblocking\n",
2802                 read ? "read" : "write", (long)*ppos, count,
2803                 nonblock ? "non" : "");
2804
2805         if (!data)
2806                 return -EINVAL;
2807
2808         if (q->waiting_in_dqbuf) {
2809                 dprintk(q, 3, "another dup()ped fd is %s\n",
2810                         read ? "reading" : "writing");
2811                 return -EBUSY;
2812         }
2813
2814         /*
2815          * Initialize emulator on first call.
2816          */
2817         if (!vb2_fileio_is_active(q)) {
2818                 ret = __vb2_init_fileio(q, read);
2819                 dprintk(q, 3, "vb2_init_fileio result: %d\n", ret);
2820                 if (ret)
2821                         return ret;
2822         }
2823         fileio = q->fileio;
2824
2825         /*
2826          * Check if we need to dequeue the buffer.
2827          */
2828         index = fileio->cur_index;
2829         if (index >= q->num_buffers) {
2830                 struct vb2_buffer *b;
2831
2832                 /*
2833                  * Call vb2_dqbuf to get buffer back.
2834                  */
2835                 ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2836                 dprintk(q, 5, "vb2_dqbuf result: %d\n", ret);
2837                 if (ret)
2838                         return ret;
2839                 fileio->dq_count += 1;
2840
2841                 fileio->cur_index = index;
2842                 buf = &fileio->bufs[index];
2843                 b = q->bufs[index];
2844
2845                 /*
2846                  * Get number of bytes filled by the driver
2847                  */
2848                 buf->pos = 0;
2849                 buf->queued = 0;
2850                 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2851                                  : vb2_plane_size(q->bufs[index], 0);
2852                 /* Compensate for data_offset on read in the multiplanar case. */
2853                 if (is_multiplanar && read &&
2854                                 b->planes[0].data_offset < buf->size) {
2855                         buf->pos = b->planes[0].data_offset;
2856                         buf->size -= buf->pos;
2857                 }
2858         } else {
2859                 buf = &fileio->bufs[index];
2860         }
2861
2862         /*
2863          * Limit count on last few bytes of the buffer.
2864          */
2865         if (buf->pos + count > buf->size) {
2866                 count = buf->size - buf->pos;
2867                 dprintk(q, 5, "reducing read count: %zd\n", count);
2868         }
2869
2870         /*
2871          * Transfer data to userspace.
2872          */
2873         dprintk(q, 3, "copying %zd bytes - buffer %d, offset %u\n",
2874                 count, index, buf->pos);
2875         if (read)
2876                 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2877         else
2878                 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2879         if (ret) {
2880                 dprintk(q, 3, "error copying data\n");
2881                 return -EFAULT;
2882         }
2883
2884         /*
2885          * Update counters.
2886          */
2887         buf->pos += count;
2888         *ppos += count;
2889
2890         /*
2891          * Queue next buffer if required.
2892          */
2893         if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2894                 struct vb2_buffer *b = q->bufs[index];
2895
2896                 /*
2897                  * Check if this is the last buffer to read.
2898                  */
2899                 if (read && fileio->read_once && fileio->dq_count == 1) {
2900                         dprintk(q, 3, "read limit reached\n");
2901                         return __vb2_cleanup_fileio(q);
2902                 }
2903
2904                 /*
2905                  * Call vb2_qbuf and give buffer to the driver.
2906                  */
2907                 b->planes[0].bytesused = buf->pos;
2908
2909                 if (copy_timestamp)
2910                         b->timestamp = ktime_get_ns();
2911                 ret = vb2_core_qbuf(q, index, NULL, NULL);
2912                 dprintk(q, 5, "vb2_dbuf result: %d\n", ret);
2913                 if (ret)
2914                         return ret;
2915
2916                 /*
2917                  * Buffer has been queued, update the status
2918                  */
2919                 buf->pos = 0;
2920                 buf->queued = 1;
2921                 buf->size = vb2_plane_size(q->bufs[index], 0);
2922                 fileio->q_count += 1;
2923                 /*
2924                  * If we are queuing up buffers for the first time, then
2925                  * increase initial_index by one.
2926                  */
2927                 if (fileio->initial_index < q->num_buffers)
2928                         fileio->initial_index++;
2929                 /*
2930                  * The next buffer to use is either a buffer that's going to be
2931                  * queued for the first time (initial_index < q->num_buffers)
2932                  * or it is equal to q->num_buffers, meaning that the next
2933                  * time we need to dequeue a buffer since we've now queued up
2934                  * all the 'first time' buffers.
2935                  */
2936                 fileio->cur_index = fileio->initial_index;
2937         }
2938
2939         /*
2940          * Return proper number of bytes processed.
2941          */
2942         if (ret == 0)
2943                 ret = count;
2944         return ret;
2945 }
2946
2947 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2948                 loff_t *ppos, int nonblocking)
2949 {
2950         return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2951 }
2952 EXPORT_SYMBOL_GPL(vb2_read);
2953
2954 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2955                 loff_t *ppos, int nonblocking)
2956 {
2957         return __vb2_perform_fileio(q, (char __user *) data, count,
2958                                                         ppos, nonblocking, 0);
2959 }
2960 EXPORT_SYMBOL_GPL(vb2_write);
2961
2962 struct vb2_threadio_data {
2963         struct task_struct *thread;
2964         vb2_thread_fnc fnc;
2965         void *priv;
2966         bool stop;
2967 };
2968
2969 static int vb2_thread(void *data)
2970 {
2971         struct vb2_queue *q = data;
2972         struct vb2_threadio_data *threadio = q->threadio;
2973         bool copy_timestamp = false;
2974         unsigned prequeue = 0;
2975         unsigned index = 0;
2976         int ret = 0;
2977
2978         if (q->is_output) {
2979                 prequeue = q->num_buffers;
2980                 copy_timestamp = q->copy_timestamp;
2981         }
2982
2983         set_freezable();
2984
2985         for (;;) {
2986                 struct vb2_buffer *vb;
2987
2988                 /*
2989                  * Call vb2_dqbuf to get buffer back.
2990                  */
2991                 if (prequeue) {
2992                         vb = q->bufs[index++];
2993                         prequeue--;
2994                 } else {
2995                         call_void_qop(q, wait_finish, q);
2996                         if (!threadio->stop)
2997                                 ret = vb2_core_dqbuf(q, &index, NULL, 0);
2998                         call_void_qop(q, wait_prepare, q);
2999                         dprintk(q, 5, "file io: vb2_dqbuf result: %d\n", ret);
3000                         if (!ret)
3001                                 vb = q->bufs[index];
3002                 }
3003                 if (ret || threadio->stop)
3004                         break;
3005                 try_to_freeze();
3006
3007                 if (vb->state != VB2_BUF_STATE_ERROR)
3008                         if (threadio->fnc(vb, threadio->priv))
3009                                 break;
3010                 call_void_qop(q, wait_finish, q);
3011                 if (copy_timestamp)
3012                         vb->timestamp = ktime_get_ns();
3013                 if (!threadio->stop)
3014                         ret = vb2_core_qbuf(q, vb->index, NULL, NULL);
3015                 call_void_qop(q, wait_prepare, q);
3016                 if (ret || threadio->stop)
3017                         break;
3018         }
3019
3020         /* Hmm, linux becomes *very* unhappy without this ... */
3021         while (!kthread_should_stop()) {
3022                 set_current_state(TASK_INTERRUPTIBLE);
3023                 schedule();
3024         }
3025         return 0;
3026 }
3027
3028 /*
3029  * This function should not be used for anything else but the videobuf2-dvb
3030  * support. If you think you have another good use-case for this, then please
3031  * contact the linux-media mailinglist first.
3032  */
3033 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
3034                      const char *thread_name)
3035 {
3036         struct vb2_threadio_data *threadio;
3037         int ret = 0;
3038
3039         if (q->threadio)
3040                 return -EBUSY;
3041         if (vb2_is_busy(q))
3042                 return -EBUSY;
3043         if (WARN_ON(q->fileio))
3044                 return -EBUSY;
3045
3046         threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
3047         if (threadio == NULL)
3048                 return -ENOMEM;
3049         threadio->fnc = fnc;
3050         threadio->priv = priv;
3051
3052         ret = __vb2_init_fileio(q, !q->is_output);
3053         dprintk(q, 3, "file io: vb2_init_fileio result: %d\n", ret);
3054         if (ret)
3055                 goto nomem;
3056         q->threadio = threadio;
3057         threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
3058         if (IS_ERR(threadio->thread)) {
3059                 ret = PTR_ERR(threadio->thread);
3060                 threadio->thread = NULL;
3061                 goto nothread;
3062         }
3063         return 0;
3064
3065 nothread:
3066         __vb2_cleanup_fileio(q);
3067 nomem:
3068         kfree(threadio);
3069         return ret;
3070 }
3071 EXPORT_SYMBOL_GPL(vb2_thread_start);
3072
3073 int vb2_thread_stop(struct vb2_queue *q)
3074 {
3075         struct vb2_threadio_data *threadio = q->threadio;
3076         int err;
3077
3078         if (threadio == NULL)
3079                 return 0;
3080         threadio->stop = true;
3081         /* Wake up all pending sleeps in the thread */
3082         vb2_queue_error(q);
3083         err = kthread_stop(threadio->thread);
3084         __vb2_cleanup_fileio(q);
3085         threadio->thread = NULL;
3086         kfree(threadio);
3087         q->threadio = NULL;
3088         return err;
3089 }
3090 EXPORT_SYMBOL_GPL(vb2_thread_stop);
3091
3092 MODULE_DESCRIPTION("Media buffer core framework");
3093 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3094 MODULE_LICENSE("GPL");
3095 MODULE_IMPORT_NS(DMA_BUF);