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         if (vb->need_cache_sync_on_prepare) {
 331                 for (plane = 0; plane < vb->num_planes; ++plane)
 332                         call_void_memop(vb, prepare,
 333                                         vb->planes[plane].mem_priv);
 334         }
 335         vb->synced = 1;
 336 }
 337
 338 /*
 339  * __vb2_buf_mem_finish() - call ->finish on buffer's private memory
 340  * to sync caches
 341  */
 342 static void __vb2_buf_mem_finish(struct vb2_buffer *vb)
 343 {
 344         unsigned int plane;
 345
 346         if (!vb->synced)
 347                 return;
 348
 349         if (vb->need_cache_sync_on_finish) {
 350                 for (plane = 0; plane < vb->num_planes; ++plane)
 351                         call_void_memop(vb, finish,
 352                                         vb->planes[plane].mem_priv);
 353         }
 354         vb->synced = 0;
 355 }
 356
 357 /*
 358  * __setup_offsets() - setup unique offsets ("cookies") for every plane in
 359  * the buffer.
 360  */
 361 static void __setup_offsets(struct vb2_buffer *vb)
 362 {
 363         struct vb2_queue *q = vb->vb2_queue;
 364         unsigned int plane;
 365         unsigned long off = 0;
 366
 367         if (vb->index) {
 368                 struct vb2_buffer *prev = q->bufs[vb->index - 1];
 369                 struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
 370
 371                 off = PAGE_ALIGN(p->m.offset + p->length);
 372         }
 373
 374         for (plane = 0; plane < vb->num_planes; ++plane) {
 375                 vb->planes[plane].m.offset = off;
 376
 377                 dprintk(q, 3, "buffer %d, plane %d offset 0x%08lx\n",
 378                                 vb->index, plane, off);
 379
 380                 off += vb->planes[plane].length;
 381                 off = PAGE_ALIGN(off);
 382         }
 383 }
 384
 385 /*
 386  * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
 387  * video buffer memory for all buffers/planes on the queue and initializes the
 388  * queue
 389  *
 390  * Returns the number of buffers successfully allocated.
 391  */
 392 static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
 393                              unsigned int num_buffers, unsigned int num_planes,
 394                              const unsigned plane_sizes[VB2_MAX_PLANES])
 395 {
 396         unsigned int buffer, plane;
 397         struct vb2_buffer *vb;
 398         int ret;
 399
 400         /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
 401         num_buffers = min_t(unsigned int, num_buffers,
 402                             VB2_MAX_FRAME - q->num_buffers);
 403
 404         for (buffer = 0; buffer < num_buffers; ++buffer) {
 405                 /* Allocate videobuf buffer structures */
 406                 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
 407                 if (!vb) {
 408                         dprintk(q, 1, "memory alloc for buffer struct failed\n");
 409                         break;
 410                 }
 411
 412                 vb->state = VB2_BUF_STATE_DEQUEUED;
 413                 vb->vb2_queue = q;
 414                 vb->num_planes = num_planes;
 415                 vb->index = q->num_buffers + buffer;
 416                 vb->type = q->type;
 417                 vb->memory = memory;
 418                 /*
 419                  * We need to set these flags here so that the videobuf2 core
 420                  * will call ->prepare()/->finish() cache sync/flush on vb2
 421                  * buffers when appropriate. However, we can avoid explicit
 422                  * ->prepare() and ->finish() cache sync for DMABUF buffers,
 423                  * because DMA exporter takes care of it.
 424                  */
 425                 if (q->memory != VB2_MEMORY_DMABUF) {
 426                         vb->need_cache_sync_on_prepare = 1;
 427                         vb->need_cache_sync_on_finish = 1;
 428                 }
 429                 for (plane = 0; plane < num_planes; ++plane) {
 430                         vb->planes[plane].length = plane_sizes[plane];
 431                         vb->planes[plane].min_length = plane_sizes[plane];
 432                 }
 433                 call_void_bufop(q, init_buffer, vb);
 434
 435                 q->bufs[vb->index] = vb;
 436
 437                 /* Allocate video buffer memory for the MMAP type */
 438                 if (memory == VB2_MEMORY_MMAP) {
 439                         ret = __vb2_buf_mem_alloc(vb);
 440                         if (ret) {
 441                                 dprintk(q, 1, "failed allocating memory for buffer %d\n",
 442                                         buffer);
 443                                 q->bufs[vb->index] = NULL;
 444                                 kfree(vb);
 445                                 break;
 446                         }
 447                         __setup_offsets(vb);
 448                         /*
 449                          * Call the driver-provided buffer initialization
 450                          * callback, if given. An error in initialization
 451                          * results in queue setup failure.
 452                          */
 453                         ret = call_vb_qop(vb, buf_init, vb);
 454                         if (ret) {
 455                                 dprintk(q, 1, "buffer %d %p initialization failed\n",
 456                                         buffer, vb);
 457                                 __vb2_buf_mem_free(vb);
 458                                 q->bufs[vb->index] = NULL;
 459                                 kfree(vb);
 460                                 break;
 461                         }
 462                 }
 463         }
 464
 465         dprintk(q, 3, "allocated %d buffers, %d plane(s) each\n",
 466                 buffer, num_planes);
 467
 468         return buffer;
 469 }
 470
 471 /*
 472  * __vb2_free_mem() - release all video buffer memory for a given queue
 473  */
 474 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
 475 {
 476         unsigned int buffer;
 477         struct vb2_buffer *vb;
 478
 479         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 480              ++buffer) {
 481                 vb = q->bufs[buffer];
 482                 if (!vb)
 483                         continue;
 484
 485                 /* Free MMAP buffers or release USERPTR buffers */
 486                 if (q->memory == VB2_MEMORY_MMAP)
 487                         __vb2_buf_mem_free(vb);
 488                 else if (q->memory == VB2_MEMORY_DMABUF)
 489                         __vb2_buf_dmabuf_put(vb);
 490                 else
 491                         __vb2_buf_userptr_put(vb);
 492         }
 493 }
 494
 495 /*
 496  * __vb2_queue_free() - free buffers at the end of the queue - video memory and
 497  * related information, if no buffers are left return the queue to an
 498  * uninitialized state. Might be called even if the queue has already been freed.
 499  */
 500 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
 501 {
 502         unsigned int buffer;
 503
 504         /*
 505          * Sanity check: when preparing a buffer the queue lock is released for
 506          * a short while (see __buf_prepare for the details), which would allow
 507          * a race with a reqbufs which can call this function. Removing the
 508          * buffers from underneath __buf_prepare is obviously a bad idea, so we
 509          * check if any of the buffers is in the state PREPARING, and if so we
 510          * just return -EAGAIN.
 511          */
 512         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 513              ++buffer) {
 514                 if (q->bufs[buffer] == NULL)
 515                         continue;
 516                 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
 517                         dprintk(q, 1, "preparing buffers, cannot free\n");
 518                         return -EAGAIN;
 519                 }
 520         }
 521
 522         /* Call driver-provided cleanup function for each buffer, if provided */
 523         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 524              ++buffer) {
 525                 struct vb2_buffer *vb = q->bufs[buffer];
 526
 527                 if (vb && vb->planes[0].mem_priv)
 528                         call_void_vb_qop(vb, buf_cleanup, vb);
 529         }
 530
 531         /* Release video buffer memory */
 532         __vb2_free_mem(q, buffers);
 533
 534 #ifdef CONFIG_VIDEO_ADV_DEBUG
 535         /*
 536          * Check that all the calls were balances during the life-time of this
 537          * queue. If not (or if the debug level is 1 or up), then dump the
 538          * counters to the kernel log.
 539          */
 540         if (q->num_buffers) {
 541                 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
 542                                   q->cnt_wait_prepare != q->cnt_wait_finish;
 543
 544                 if (unbalanced || debug) {
 545                         pr_info("counters for queue %p:%s\n", q,
 546                                 unbalanced ? " UNBALANCED!" : "");
 547                         pr_info("     setup: %u start_streaming: %u stop_streaming: %u\n",
 548                                 q->cnt_queue_setup, q->cnt_start_streaming,
 549                                 q->cnt_stop_streaming);
 550                         pr_info("     wait_prepare: %u wait_finish: %u\n",
 551                                 q->cnt_wait_prepare, q->cnt_wait_finish);
 552                 }
 553                 q->cnt_queue_setup = 0;
 554                 q->cnt_wait_prepare = 0;
 555                 q->cnt_wait_finish = 0;
 556                 q->cnt_start_streaming = 0;
 557                 q->cnt_stop_streaming = 0;
 558         }
 559         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 560                 struct vb2_buffer *vb = q->bufs[buffer];
 561                 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
 562                                   vb->cnt_mem_prepare != vb->cnt_mem_finish ||
 563                                   vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
 564                                   vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
 565                                   vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
 566                                   vb->cnt_buf_queue != vb->cnt_buf_done ||
 567                                   vb->cnt_buf_prepare != vb->cnt_buf_finish ||
 568                                   vb->cnt_buf_init != vb->cnt_buf_cleanup;
 569
 570                 if (unbalanced || debug) {
 571                         pr_info("   counters for queue %p, buffer %d:%s\n",
 572                                 q, buffer, unbalanced ? " UNBALANCED!" : "");
 573                         pr_info("     buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
 574                                 vb->cnt_buf_init, vb->cnt_buf_cleanup,
 575                                 vb->cnt_buf_prepare, vb->cnt_buf_finish);
 576                         pr_info("     buf_out_validate: %u buf_queue: %u buf_done: %u buf_request_complete: %u\n",
 577                                 vb->cnt_buf_out_validate, vb->cnt_buf_queue,
 578                                 vb->cnt_buf_done, vb->cnt_buf_request_complete);
 579                         pr_info("     alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
 580                                 vb->cnt_mem_alloc, vb->cnt_mem_put,
 581                                 vb->cnt_mem_prepare, vb->cnt_mem_finish,
 582                                 vb->cnt_mem_mmap);
 583                         pr_info("     get_userptr: %u put_userptr: %u\n",
 584                                 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
 585                         pr_info("     attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
 586                                 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
 587                                 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
 588                         pr_info("     get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
 589                                 vb->cnt_mem_get_dmabuf,
 590                                 vb->cnt_mem_num_users,
 591                                 vb->cnt_mem_vaddr,
 592                                 vb->cnt_mem_cookie);
 593                 }
 594         }
 595 #endif
 596
 597         /* Free videobuf buffers */
 598         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 599              ++buffer) {
 600                 kfree(q->bufs[buffer]);
 601                 q->bufs[buffer] = NULL;
 602         }
 603
 604         q->num_buffers -= buffers;
 605         if (!q->num_buffers) {
 606                 q->memory = VB2_MEMORY_UNKNOWN;
 607                 INIT_LIST_HEAD(&q->queued_list);
 608         }
 609         return 0;
 610 }
 611
 612 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
 613 {
 614         unsigned int plane;
 615         for (plane = 0; plane < vb->num_planes; ++plane) {
 616                 void *mem_priv = vb->planes[plane].mem_priv;
 617                 /*
 618                  * If num_users() has not been provided, call_memop
 619                  * will return 0, apparently nobody cares about this
 620                  * case anyway. If num_users() returns more than 1,
 621                  * we are not the only user of the plane's memory.
 622                  */
 623                 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
 624                         return true;
 625         }
 626         return false;
 627 }
 628 EXPORT_SYMBOL(vb2_buffer_in_use);
 629
 630 /*
 631  * __buffers_in_use() - return true if any buffers on the queue are in use and
 632  * the queue cannot be freed (by the means of REQBUFS(0)) call
 633  */
 634 static bool __buffers_in_use(struct vb2_queue *q)
 635 {
 636         unsigned int buffer;
 637         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 638                 if (vb2_buffer_in_use(q, q->bufs[buffer]))
 639                         return true;
 640         }
 641         return false;
 642 }
 643
 644 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
 645 {
 646         call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
 647 }
 648 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
 649
 650 /*
 651  * __verify_userptr_ops() - verify that all memory operations required for
 652  * USERPTR queue type have been provided
 653  */
 654 static int __verify_userptr_ops(struct vb2_queue *q)
 655 {
 656         if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
 657             !q->mem_ops->put_userptr)
 658                 return -EINVAL;
 659
 660         return 0;
 661 }
 662
 663 /*
 664  * __verify_mmap_ops() - verify that all memory operations required for
 665  * MMAP queue type have been provided
 666  */
 667 static int __verify_mmap_ops(struct vb2_queue *q)
 668 {
 669         if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
 670             !q->mem_ops->put || !q->mem_ops->mmap)
 671                 return -EINVAL;
 672
 673         return 0;
 674 }
 675
 676 /*
 677  * __verify_dmabuf_ops() - verify that all memory operations required for
 678  * DMABUF queue type have been provided
 679  */
 680 static int __verify_dmabuf_ops(struct vb2_queue *q)
 681 {
 682         if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
 683             !q->mem_ops->detach_dmabuf  || !q->mem_ops->map_dmabuf ||
 684             !q->mem_ops->unmap_dmabuf)
 685                 return -EINVAL;
 686
 687         return 0;
 688 }
 689
 690 int vb2_verify_memory_type(struct vb2_queue *q,
 691                 enum vb2_memory memory, unsigned int type)
 692 {
 693         if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
 694             memory != VB2_MEMORY_DMABUF) {
 695                 dprintk(q, 1, "unsupported memory type\n");
 696                 return -EINVAL;
 697         }
 698
 699         if (type != q->type) {
 700                 dprintk(q, 1, "requested type is incorrect\n");
 701                 return -EINVAL;
 702         }
 703
 704         /*
 705          * Make sure all the required memory ops for given memory type
 706          * are available.
 707          */
 708         if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
 709                 dprintk(q, 1, "MMAP for current setup unsupported\n");
 710                 return -EINVAL;
 711         }
 712
 713         if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
 714                 dprintk(q, 1, "USERPTR for current setup unsupported\n");
 715                 return -EINVAL;
 716         }
 717
 718         if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
 719                 dprintk(q, 1, "DMABUF for current setup unsupported\n");
 720                 return -EINVAL;
 721         }
 722
 723         /*
 724          * Place the busy tests at the end: -EBUSY can be ignored when
 725          * create_bufs is called with count == 0, but count == 0 should still
 726          * do the memory and type validation.
 727          */
 728         if (vb2_fileio_is_active(q)) {
 729                 dprintk(q, 1, "file io in progress\n");
 730                 return -EBUSY;
 731         }
 732         return 0;
 733 }
 734 EXPORT_SYMBOL(vb2_verify_memory_type);
 735
 736 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 737                      unsigned int *count)
 738 {
 739         unsigned int num_buffers, allocated_buffers, num_planes = 0;
 740         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 741         unsigned int i;
 742         int ret;
 743
 744         if (q->streaming) {
 745                 dprintk(q, 1, "streaming active\n");
 746                 return -EBUSY;
 747         }
 748
 749         if (q->waiting_in_dqbuf && *count) {
 750                 dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
 751                 return -EBUSY;
 752         }
 753
 754         if (*count == 0 || q->num_buffers != 0 ||
 755             (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory)) {
 756                 /*
 757                  * We already have buffers allocated, so first check if they
 758                  * are not in use and can be freed.
 759                  */
 760                 mutex_lock(&q->mmap_lock);
 761                 if (debug && q->memory == VB2_MEMORY_MMAP &&
 762                     __buffers_in_use(q))
 763                         dprintk(q, 1, "memory in use, orphaning buffers\n");
 764
 765                 /*
 766                  * Call queue_cancel to clean up any buffers in the
 767                  * QUEUED state which is possible if buffers were prepared or
 768                  * queued without ever calling STREAMON.
 769                  */
 770                 __vb2_queue_cancel(q);
 771                 ret = __vb2_queue_free(q, q->num_buffers);
 772                 mutex_unlock(&q->mmap_lock);
 773                 if (ret)
 774                         return ret;
 775
 776                 /*
 777                  * In case of REQBUFS(0) return immediately without calling
 778                  * driver's queue_setup() callback and allocating resources.
 779                  */
 780                 if (*count == 0)
 781                         return 0;
 782         }
 783
 784         /*
 785          * Make sure the requested values and current defaults are sane.
 786          */
 787         WARN_ON(q->min_buffers_needed > VB2_MAX_FRAME);
 788         num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);
 789         num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);
 790         memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 791         q->memory = memory;
 792
 793         /*
 794          * Ask the driver how many buffers and planes per buffer it requires.
 795          * Driver also sets the size and allocator context for each plane.
 796          */
 797         ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
 798                        plane_sizes, q->alloc_devs);
 799         if (ret)
 800                 return ret;
 801
 802         /* Check that driver has set sane values */
 803         if (WARN_ON(!num_planes))
 804                 return -EINVAL;
 805
 806         for (i = 0; i < num_planes; i++)
 807                 if (WARN_ON(!plane_sizes[i]))
 808                         return -EINVAL;
 809
 810         /* Finally, allocate buffers and video memory */
 811         allocated_buffers =
 812                 __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
 813         if (allocated_buffers == 0) {
 814                 dprintk(q, 1, "memory allocation failed\n");
 815                 return -ENOMEM;
 816         }
 817
 818         /*
 819          * There is no point in continuing if we can't allocate the minimum
 820          * number of buffers needed by this vb2_queue.
 821          */
 822         if (allocated_buffers < q->min_buffers_needed)
 823                 ret = -ENOMEM;
 824
 825         /*
 826          * Check if driver can handle the allocated number of buffers.
 827          */
 828         if (!ret && allocated_buffers < num_buffers) {
 829                 num_buffers = allocated_buffers;
 830                 /*
 831                  * num_planes is set by the previous queue_setup(), but since it
 832                  * signals to queue_setup() whether it is called from create_bufs()
 833                  * vs reqbufs() we zero it here to signal that queue_setup() is
 834                  * called for the reqbufs() case.
 835                  */
 836                 num_planes = 0;
 837
 838                 ret = call_qop(q, queue_setup, q, &num_buffers,
 839                                &num_planes, plane_sizes, q->alloc_devs);
 840
 841                 if (!ret && allocated_buffers < num_buffers)
 842                         ret = -ENOMEM;
 843
 844                 /*
 845                  * Either the driver has accepted a smaller number of buffers,
 846                  * or .queue_setup() returned an error
 847                  */
 848         }
 849
 850         mutex_lock(&q->mmap_lock);
 851         q->num_buffers = allocated_buffers;
 852
 853         if (ret < 0) {
 854                 /*
 855                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 856                  * from q->num_buffers.
 857                  */
 858                 __vb2_queue_free(q, allocated_buffers);
 859                 mutex_unlock(&q->mmap_lock);
 860                 return ret;
 861         }
 862         mutex_unlock(&q->mmap_lock);
 863
 864         /*
 865          * Return the number of successfully allocated buffers
 866          * to the userspace.
 867          */
 868         *count = allocated_buffers;
 869         q->waiting_for_buffers = !q->is_output;
 870
 871         return 0;
 872 }
 873 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
 874
 875 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 876                          unsigned int *count,
 877                          unsigned int requested_planes,
 878                          const unsigned int requested_sizes[])
 879 {
 880         unsigned int num_planes = 0, num_buffers, allocated_buffers;
 881         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 882         int ret;
 883
 884         if (q->num_buffers == VB2_MAX_FRAME) {
 885                 dprintk(q, 1, "maximum number of buffers already allocated\n");
 886                 return -ENOBUFS;
 887         }
 888
 889         if (!q->num_buffers) {
 890                 if (q->waiting_in_dqbuf && *count) {
 891                         dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
 892                         return -EBUSY;
 893                 }
 894                 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 895                 q->memory = memory;
 896                 q->waiting_for_buffers = !q->is_output;
 897         } else {
 898                 if (q->memory != memory) {
 899                         dprintk(q, 1, "memory model mismatch\n");
 900                         return -EINVAL;
 901                 }
 902         }
 903
 904         num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
 905
 906         if (requested_planes && requested_sizes) {
 907                 num_planes = requested_planes;
 908                 memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
 909         }
 910
 911         /*
 912          * Ask the driver, whether the requested number of buffers, planes per
 913          * buffer and their sizes are acceptable
 914          */
 915         ret = call_qop(q, queue_setup, q, &num_buffers,
 916                        &num_planes, plane_sizes, q->alloc_devs);
 917         if (ret)
 918                 return ret;
 919
 920         /* Finally, allocate buffers and video memory */
 921         allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
 922                                 num_planes, plane_sizes);
 923         if (allocated_buffers == 0) {
 924                 dprintk(q, 1, "memory allocation failed\n");
 925                 return -ENOMEM;
 926         }
 927
 928         /*
 929          * Check if driver can handle the so far allocated number of buffers.
 930          */
 931         if (allocated_buffers < num_buffers) {
 932                 num_buffers = allocated_buffers;
 933
 934                 /*
 935                  * q->num_buffers contains the total number of buffers, that the
 936                  * queue driver has set up
 937                  */
 938                 ret = call_qop(q, queue_setup, q, &num_buffers,
 939                                &num_planes, plane_sizes, q->alloc_devs);
 940
 941                 if (!ret && allocated_buffers < num_buffers)
 942                         ret = -ENOMEM;
 943
 944                 /*
 945                  * Either the driver has accepted a smaller number of buffers,
 946                  * or .queue_setup() returned an error
 947                  */
 948         }
 949
 950         mutex_lock(&q->mmap_lock);
 951         q->num_buffers += allocated_buffers;
 952
 953         if (ret < 0) {
 954                 /*
 955                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 956                  * from q->num_buffers.
 957                  */
 958                 __vb2_queue_free(q, allocated_buffers);
 959                 mutex_unlock(&q->mmap_lock);
 960                 return -ENOMEM;
 961         }
 962         mutex_unlock(&q->mmap_lock);
 963
 964         /*
 965          * Return the number of successfully allocated buffers
 966          * to the userspace.
 967          */
 968         *count = allocated_buffers;
 969
 970         return 0;
 971 }
 972 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
 973
 974 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
 975 {
 976         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
 977                 return NULL;
 978
 979         return call_ptr_memop(vaddr, vb, vb->planes[plane_no].mem_priv);
 980
 981 }
 982 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
 983
 984 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
 985 {
 986         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
 987                 return NULL;
 988
 989         return call_ptr_memop(cookie, vb, vb->planes[plane_no].mem_priv);
 990 }
 991 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
 992
 993 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
 994 {
 995         struct vb2_queue *q = vb->vb2_queue;
 996         unsigned long flags;
 997
 998         if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
 999                 return;
1000
1001         if (WARN_ON(state != VB2_BUF_STATE_DONE &&
1002                     state != VB2_BUF_STATE_ERROR &&
1003                     state != VB2_BUF_STATE_QUEUED))
1004                 state = VB2_BUF_STATE_ERROR;
1005
1006 #ifdef CONFIG_VIDEO_ADV_DEBUG
1007         /*
1008          * Although this is not a callback, it still does have to balance
1009          * with the buf_queue op. So update this counter manually.
1010          */
1011         vb->cnt_buf_done++;
1012 #endif
1013         dprintk(q, 4, "done processing on buffer %d, state: %s\n",
1014                 vb->index, vb2_state_name(state));
1015
1016         if (state != VB2_BUF_STATE_QUEUED)
1017                 __vb2_buf_mem_finish(vb);
1018
1019         spin_lock_irqsave(&q->done_lock, flags);
1020         if (state == VB2_BUF_STATE_QUEUED) {
1021                 vb->state = VB2_BUF_STATE_QUEUED;
1022         } else {
1023                 /* Add the buffer to the done buffers list */
1024                 list_add_tail(&vb->done_entry, &q->done_list);
1025                 vb->state = state;
1026         }
1027         atomic_dec(&q->owned_by_drv_count);
1028
1029         if (state != VB2_BUF_STATE_QUEUED && vb->req_obj.req) {
1030                 media_request_object_unbind(&vb->req_obj);
1031                 media_request_object_put(&vb->req_obj);
1032         }
1033
1034         spin_unlock_irqrestore(&q->done_lock, flags);
1035
1036         trace_vb2_buf_done(q, vb);
1037
1038         switch (state) {
1039         case VB2_BUF_STATE_QUEUED:
1040                 return;
1041         default:
1042                 /* Inform any processes that may be waiting for buffers */
1043                 wake_up(&q->done_wq);
1044                 break;
1045         }
1046 }
1047 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1048
1049 void vb2_discard_done(struct vb2_queue *q)
1050 {
1051         struct vb2_buffer *vb;
1052         unsigned long flags;
1053
1054         spin_lock_irqsave(&q->done_lock, flags);
1055         list_for_each_entry(vb, &q->done_list, done_entry)
1056                 vb->state = VB2_BUF_STATE_ERROR;
1057         spin_unlock_irqrestore(&q->done_lock, flags);
1058 }
1059 EXPORT_SYMBOL_GPL(vb2_discard_done);
1060
1061 /*
1062  * __prepare_mmap() - prepare an MMAP buffer
1063  */
1064 static int __prepare_mmap(struct vb2_buffer *vb)
1065 {
1066         int ret = 0;
1067
1068         ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1069                          vb, vb->planes);
1070         return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
1071 }
1072
1073 /*
1074  * __prepare_userptr() - prepare a USERPTR buffer
1075  */
1076 static int __prepare_userptr(struct vb2_buffer *vb)
1077 {
1078         struct vb2_plane planes[VB2_MAX_PLANES];
1079         struct vb2_queue *q = vb->vb2_queue;
1080         void *mem_priv;
1081         unsigned int plane;
1082         int ret = 0;
1083         bool reacquired = vb->planes[0].mem_priv == NULL;
1084
1085         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1086         /* Copy relevant information provided by the userspace */
1087         ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1088                          vb, planes);
1089         if (ret)
1090                 return ret;
1091
1092         for (plane = 0; plane < vb->num_planes; ++plane) {
1093                 /* Skip the plane if already verified */
1094                 if (vb->planes[plane].m.userptr &&
1095                         vb->planes[plane].m.userptr == planes[plane].m.userptr
1096                         && vb->planes[plane].length == planes[plane].length)
1097                         continue;
1098
1099                 dprintk(q, 3, "userspace address for plane %d changed, reacquiring memory\n",
1100                         plane);
1101
1102                 /* Check if the provided plane buffer is large enough */
1103                 if (planes[plane].length < vb->planes[plane].min_length) {
1104                         dprintk(q, 1, "provided buffer size %u is less than setup size %u for plane %d\n",
1105                                                 planes[plane].length,
1106                                                 vb->planes[plane].min_length,
1107                                                 plane);
1108                         ret = -EINVAL;
1109                         goto err;
1110                 }
1111
1112                 /* Release previously acquired memory if present */
1113                 if (vb->planes[plane].mem_priv) {
1114                         if (!reacquired) {
1115                                 reacquired = true;
1116                                 vb->copied_timestamp = 0;
1117                                 call_void_vb_qop(vb, buf_cleanup, vb);
1118                         }
1119                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1120                 }
1121
1122                 vb->planes[plane].mem_priv = NULL;
1123                 vb->planes[plane].bytesused = 0;
1124                 vb->planes[plane].length = 0;
1125                 vb->planes[plane].m.userptr = 0;
1126                 vb->planes[plane].data_offset = 0;
1127
1128                 /* Acquire each plane's memory */
1129                 mem_priv = call_ptr_memop(get_userptr,
1130                                           vb,
1131                                           q->alloc_devs[plane] ? : q->dev,
1132                                           planes[plane].m.userptr,
1133                                           planes[plane].length);
1134                 if (IS_ERR(mem_priv)) {
1135                         dprintk(q, 1, "failed acquiring userspace memory for plane %d\n",
1136                                 plane);
1137                         ret = PTR_ERR(mem_priv);
1138                         goto err;
1139                 }
1140                 vb->planes[plane].mem_priv = mem_priv;
1141         }
1142
1143         /*
1144          * Now that everything is in order, copy relevant information
1145          * provided by userspace.
1146          */
1147         for (plane = 0; plane < vb->num_planes; ++plane) {
1148                 vb->planes[plane].bytesused = planes[plane].bytesused;
1149                 vb->planes[plane].length = planes[plane].length;
1150                 vb->planes[plane].m.userptr = planes[plane].m.userptr;
1151                 vb->planes[plane].data_offset = planes[plane].data_offset;
1152         }
1153
1154         if (reacquired) {
1155                 /*
1156                  * One or more planes changed, so we must call buf_init to do
1157                  * the driver-specific initialization on the newly acquired
1158                  * buffer, if provided.
1159                  */
1160                 ret = call_vb_qop(vb, buf_init, vb);
1161                 if (ret) {
1162                         dprintk(q, 1, "buffer initialization failed\n");
1163                         goto err;
1164                 }
1165         }
1166
1167         ret = call_vb_qop(vb, buf_prepare, vb);
1168         if (ret) {
1169                 dprintk(q, 1, "buffer preparation failed\n");
1170                 call_void_vb_qop(vb, buf_cleanup, vb);
1171                 goto err;
1172         }
1173
1174         return 0;
1175 err:
1176         /* In case of errors, release planes that were already acquired */
1177         for (plane = 0; plane < vb->num_planes; ++plane) {
1178                 if (vb->planes[plane].mem_priv)
1179                         call_void_memop(vb, put_userptr,
1180                                 vb->planes[plane].mem_priv);
1181                 vb->planes[plane].mem_priv = NULL;
1182                 vb->planes[plane].m.userptr = 0;
1183                 vb->planes[plane].length = 0;
1184         }
1185
1186         return ret;
1187 }
1188
1189 /*
1190  * __prepare_dmabuf() - prepare a DMABUF buffer
1191  */
1192 static int __prepare_dmabuf(struct vb2_buffer *vb)
1193 {
1194         struct vb2_plane planes[VB2_MAX_PLANES];
1195         struct vb2_queue *q = vb->vb2_queue;
1196         void *mem_priv;
1197         unsigned int plane;
1198         int ret = 0;
1199         bool reacquired = vb->planes[0].mem_priv == NULL;
1200
1201         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1202         /* Copy relevant information provided by the userspace */
1203         ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1204                          vb, planes);
1205         if (ret)
1206                 return ret;
1207
1208         for (plane = 0; plane < vb->num_planes; ++plane) {
1209                 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1210
1211                 if (IS_ERR_OR_NULL(dbuf)) {
1212                         dprintk(q, 1, "invalid dmabuf fd for plane %d\n",
1213                                 plane);
1214                         ret = -EINVAL;
1215                         goto err;
1216                 }
1217
1218                 /* use DMABUF size if length is not provided */
1219                 if (planes[plane].length == 0)
1220                         planes[plane].length = dbuf->size;
1221
1222                 if (planes[plane].length < vb->planes[plane].min_length) {
1223                         dprintk(q, 1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
1224                                 planes[plane].length, plane,
1225                                 vb->planes[plane].min_length);
1226                         dma_buf_put(dbuf);
1227                         ret = -EINVAL;
1228                         goto err;
1229                 }
1230
1231                 /* Skip the plane if already verified */
1232                 if (dbuf == vb->planes[plane].dbuf &&
1233                         vb->planes[plane].length == planes[plane].length) {
1234                         dma_buf_put(dbuf);
1235                         continue;
1236                 }
1237
1238                 dprintk(q, 3, "buffer for plane %d changed\n", plane);
1239
1240                 if (!reacquired) {
1241                         reacquired = true;
1242                         vb->copied_timestamp = 0;
1243                         call_void_vb_qop(vb, buf_cleanup, vb);
1244                 }
1245
1246                 /* Release previously acquired memory if present */
1247                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1248                 vb->planes[plane].bytesused = 0;
1249                 vb->planes[plane].length = 0;
1250                 vb->planes[plane].m.fd = 0;
1251                 vb->planes[plane].data_offset = 0;
1252
1253                 /* Acquire each plane's memory */
1254                 mem_priv = call_ptr_memop(attach_dmabuf,
1255                                           vb,
1256                                           q->alloc_devs[plane] ? : q->dev,
1257                                           dbuf,
1258                                           planes[plane].length);
1259                 if (IS_ERR(mem_priv)) {
1260                         dprintk(q, 1, "failed to attach dmabuf\n");
1261                         ret = PTR_ERR(mem_priv);
1262                         dma_buf_put(dbuf);
1263                         goto err;
1264                 }
1265
1266                 vb->planes[plane].dbuf = dbuf;
1267                 vb->planes[plane].mem_priv = mem_priv;
1268         }
1269
1270         /*
1271          * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1272          * here instead just before the DMA, while queueing the buffer(s) so
1273          * userspace knows sooner rather than later if the dma-buf map fails.
1274          */
1275         for (plane = 0; plane < vb->num_planes; ++plane) {
1276                 if (vb->planes[plane].dbuf_mapped)
1277                         continue;
1278
1279                 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1280                 if (ret) {
1281                         dprintk(q, 1, "failed to map dmabuf for plane %d\n",
1282                                 plane);
1283                         goto err;
1284                 }
1285                 vb->planes[plane].dbuf_mapped = 1;
1286         }
1287
1288         /*
1289          * Now that everything is in order, copy relevant information
1290          * provided by userspace.
1291          */
1292         for (plane = 0; plane < vb->num_planes; ++plane) {
1293                 vb->planes[plane].bytesused = planes[plane].bytesused;
1294                 vb->planes[plane].length = planes[plane].length;
1295                 vb->planes[plane].m.fd = planes[plane].m.fd;
1296                 vb->planes[plane].data_offset = planes[plane].data_offset;
1297         }
1298
1299         if (reacquired) {
1300                 /*
1301                  * Call driver-specific initialization on the newly acquired buffer,
1302                  * if provided.
1303                  */
1304                 ret = call_vb_qop(vb, buf_init, vb);
1305                 if (ret) {
1306                         dprintk(q, 1, "buffer initialization failed\n");
1307                         goto err;
1308                 }
1309         }
1310
1311         ret = call_vb_qop(vb, buf_prepare, vb);
1312         if (ret) {
1313                 dprintk(q, 1, "buffer preparation failed\n");
1314                 call_void_vb_qop(vb, buf_cleanup, vb);
1315                 goto err;
1316         }
1317
1318         return 0;
1319 err:
1320         /* In case of errors, release planes that were already acquired */
1321         __vb2_buf_dmabuf_put(vb);
1322
1323         return ret;
1324 }
1325
1326 /*
1327  * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1328  */
1329 static void __enqueue_in_driver(struct vb2_buffer *vb)
1330 {
1331         struct vb2_queue *q = vb->vb2_queue;
1332
1333         vb->state = VB2_BUF_STATE_ACTIVE;
1334         atomic_inc(&q->owned_by_drv_count);
1335
1336         trace_vb2_buf_queue(q, vb);
1337
1338         call_void_vb_qop(vb, buf_queue, vb);
1339 }
1340
1341 static int __buf_prepare(struct vb2_buffer *vb)
1342 {
1343         struct vb2_queue *q = vb->vb2_queue;
1344         enum vb2_buffer_state orig_state = vb->state;
1345         int ret;
1346
1347         if (q->error) {
1348                 dprintk(q, 1, "fatal error occurred on queue\n");
1349                 return -EIO;
1350         }
1351
1352         if (vb->prepared)
1353                 return 0;
1354         WARN_ON(vb->synced);
1355
1356         if (q->is_output) {
1357                 ret = call_vb_qop(vb, buf_out_validate, vb);
1358                 if (ret) {
1359                         dprintk(q, 1, "buffer validation failed\n");
1360                         return ret;
1361                 }
1362         }
1363
1364         vb->state = VB2_BUF_STATE_PREPARING;
1365
1366         switch (q->memory) {
1367         case VB2_MEMORY_MMAP:
1368                 ret = __prepare_mmap(vb);
1369                 break;
1370         case VB2_MEMORY_USERPTR:
1371                 ret = __prepare_userptr(vb);
1372                 break;
1373         case VB2_MEMORY_DMABUF:
1374                 ret = __prepare_dmabuf(vb);
1375                 break;
1376         default:
1377                 WARN(1, "Invalid queue type\n");
1378                 ret = -EINVAL;
1379                 break;
1380         }
1381
1382         if (ret) {
1383                 dprintk(q, 1, "buffer preparation failed: %d\n", ret);
1384                 vb->state = orig_state;
1385                 return ret;
1386         }
1387
1388         __vb2_buf_mem_prepare(vb);
1389         vb->prepared = 1;
1390         vb->state = orig_state;
1391
1392         return 0;
1393 }
1394
1395 static int vb2_req_prepare(struct media_request_object *obj)
1396 {
1397         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1398         int ret;
1399
1400         if (WARN_ON(vb->state != VB2_BUF_STATE_IN_REQUEST))
1401                 return -EINVAL;
1402
1403         mutex_lock(vb->vb2_queue->lock);
1404         ret = __buf_prepare(vb);
1405         mutex_unlock(vb->vb2_queue->lock);
1406         return ret;
1407 }
1408
1409 static void __vb2_dqbuf(struct vb2_buffer *vb);
1410
1411 static void vb2_req_unprepare(struct media_request_object *obj)
1412 {
1413         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1414
1415         mutex_lock(vb->vb2_queue->lock);
1416         __vb2_dqbuf(vb);
1417         vb->state = VB2_BUF_STATE_IN_REQUEST;
1418         mutex_unlock(vb->vb2_queue->lock);
1419         WARN_ON(!vb->req_obj.req);
1420 }
1421
1422 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1423                   struct media_request *req);
1424
1425 static void vb2_req_queue(struct media_request_object *obj)
1426 {
1427         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1428
1429         mutex_lock(vb->vb2_queue->lock);
1430         vb2_core_qbuf(vb->vb2_queue, vb->index, NULL, NULL);
1431         mutex_unlock(vb->vb2_queue->lock);
1432 }
1433
1434 static void vb2_req_unbind(struct media_request_object *obj)
1435 {
1436         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1437
1438         if (vb->state == VB2_BUF_STATE_IN_REQUEST)
1439                 call_void_bufop(vb->vb2_queue, init_buffer, vb);
1440 }
1441
1442 static void vb2_req_release(struct media_request_object *obj)
1443 {
1444         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1445
1446         if (vb->state == VB2_BUF_STATE_IN_REQUEST) {
1447                 vb->state = VB2_BUF_STATE_DEQUEUED;
1448                 if (vb->request)
1449                         media_request_put(vb->request);
1450                 vb->request = NULL;
1451         }
1452 }
1453
1454 static const struct media_request_object_ops vb2_core_req_ops = {
1455         .prepare = vb2_req_prepare,
1456         .unprepare = vb2_req_unprepare,
1457         .queue = vb2_req_queue,
1458         .unbind = vb2_req_unbind,
1459         .release = vb2_req_release,
1460 };
1461
1462 bool vb2_request_object_is_buffer(struct media_request_object *obj)
1463 {
1464         return obj->ops == &vb2_core_req_ops;
1465 }
1466 EXPORT_SYMBOL_GPL(vb2_request_object_is_buffer);
1467
1468 unsigned int vb2_request_buffer_cnt(struct media_request *req)
1469 {
1470         struct media_request_object *obj;
1471         unsigned long flags;
1472         unsigned int buffer_cnt = 0;
1473
1474         spin_lock_irqsave(&req->lock, flags);
1475         list_for_each_entry(obj, &req->objects, list)
1476                 if (vb2_request_object_is_buffer(obj))
1477                         buffer_cnt++;
1478         spin_unlock_irqrestore(&req->lock, flags);
1479
1480         return buffer_cnt;
1481 }
1482 EXPORT_SYMBOL_GPL(vb2_request_buffer_cnt);
1483
1484 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1485 {
1486         struct vb2_buffer *vb;
1487         int ret;
1488
1489         vb = q->bufs[index];
1490         if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1491                 dprintk(q, 1, "invalid buffer state %s\n",
1492                         vb2_state_name(vb->state));
1493                 return -EINVAL;
1494         }
1495         if (vb->prepared) {
1496                 dprintk(q, 1, "buffer already prepared\n");
1497                 return -EINVAL;
1498         }
1499
1500         ret = __buf_prepare(vb);
1501         if (ret)
1502                 return ret;
1503
1504         /* Fill buffer information for the userspace */
1505         call_void_bufop(q, fill_user_buffer, vb, pb);
1506
1507         dprintk(q, 2, "prepare of buffer %d succeeded\n", vb->index);
1508
1509         return 0;
1510 }
1511 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1512
1513 /*
1514  * vb2_start_streaming() - Attempt to start streaming.
1515  * @q:          videobuf2 queue
1516  *
1517  * Attempt to start streaming. When this function is called there must be
1518  * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1519  * number of buffers required for the DMA engine to function). If the
1520  * @start_streaming op fails it is supposed to return all the driver-owned
1521  * buffers back to vb2 in state QUEUED. Check if that happened and if
1522  * not warn and reclaim them forcefully.
1523  */
1524 static int vb2_start_streaming(struct vb2_queue *q)
1525 {
1526         struct vb2_buffer *vb;
1527         int ret;
1528
1529         /*
1530          * If any buffers were queued before streamon,
1531          * we can now pass them to driver for processing.
1532          */
1533         list_for_each_entry(vb, &q->queued_list, queued_entry)
1534                 __enqueue_in_driver(vb);
1535
1536         /* Tell the driver to start streaming */
1537         q->start_streaming_called = 1;
1538         ret = call_qop(q, start_streaming, q,
1539                        atomic_read(&q->owned_by_drv_count));
1540         if (!ret)
1541                 return 0;
1542
1543         q->start_streaming_called = 0;
1544
1545         dprintk(q, 1, "driver refused to start streaming\n");
1546         /*
1547          * If you see this warning, then the driver isn't cleaning up properly
1548          * after a failed start_streaming(). See the start_streaming()
1549          * documentation in videobuf2-core.h for more information how buffers
1550          * should be returned to vb2 in start_streaming().
1551          */
1552         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1553                 unsigned i;
1554
1555                 /*
1556                  * Forcefully reclaim buffers if the driver did not
1557                  * correctly return them to vb2.
1558                  */
1559                 for (i = 0; i < q->num_buffers; ++i) {
1560                         vb = q->bufs[i];
1561                         if (vb->state == VB2_BUF_STATE_ACTIVE)
1562                                 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1563                 }
1564                 /* Must be zero now */
1565                 WARN_ON(atomic_read(&q->owned_by_drv_count));
1566         }
1567         /*
1568          * If done_list is not empty, then start_streaming() didn't call
1569          * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1570          * STATE_DONE.
1571          */
1572         WARN_ON(!list_empty(&q->done_list));
1573         return ret;
1574 }
1575
1576 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1577                   struct media_request *req)
1578 {
1579         struct vb2_buffer *vb;
1580         enum vb2_buffer_state orig_state;
1581         int ret;
1582
1583         if (q->error) {
1584                 dprintk(q, 1, "fatal error occurred on queue\n");
1585                 return -EIO;
1586         }
1587
1588         vb = q->bufs[index];
1589
1590         if (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1591             q->requires_requests) {
1592                 dprintk(q, 1, "qbuf requires a request\n");
1593                 return -EBADR;
1594         }
1595
1596         if ((req && q->uses_qbuf) ||
1597             (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1598              q->uses_requests)) {
1599                 dprintk(q, 1, "queue in wrong mode (qbuf vs requests)\n");
1600                 return -EBUSY;
1601         }
1602
1603         if (req) {
1604                 int ret;
1605
1606                 q->uses_requests = 1;
1607                 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1608                         dprintk(q, 1, "buffer %d not in dequeued state\n",
1609                                 vb->index);
1610                         return -EINVAL;
1611                 }
1612
1613                 if (q->is_output && !vb->prepared) {
1614                         ret = call_vb_qop(vb, buf_out_validate, vb);
1615                         if (ret) {
1616                                 dprintk(q, 1, "buffer validation failed\n");
1617                                 return ret;
1618                         }
1619                 }
1620
1621                 media_request_object_init(&vb->req_obj);
1622
1623                 /* Make sure the request is in a safe state for updating. */
1624                 ret = media_request_lock_for_update(req);
1625                 if (ret)
1626                         return ret;
1627                 ret = media_request_object_bind(req, &vb2_core_req_ops,
1628                                                 q, true, &vb->req_obj);
1629                 media_request_unlock_for_update(req);
1630                 if (ret)
1631                         return ret;
1632
1633                 vb->state = VB2_BUF_STATE_IN_REQUEST;
1634
1635                 /*
1636                  * Increment the refcount and store the request.
1637                  * The request refcount is decremented again when the
1638                  * buffer is dequeued. This is to prevent vb2_buffer_done()
1639                  * from freeing the request from interrupt context, which can
1640                  * happen if the application closed the request fd after
1641                  * queueing the request.
1642                  */
1643                 media_request_get(req);
1644                 vb->request = req;
1645
1646                 /* Fill buffer information for the userspace */
1647                 if (pb) {
1648                         call_void_bufop(q, copy_timestamp, vb, pb);
1649                         call_void_bufop(q, fill_user_buffer, vb, pb);
1650                 }
1651
1652                 dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
1653                 return 0;
1654         }
1655
1656         if (vb->state != VB2_BUF_STATE_IN_REQUEST)
1657                 q->uses_qbuf = 1;
1658
1659         switch (vb->state) {
1660         case VB2_BUF_STATE_DEQUEUED:
1661         case VB2_BUF_STATE_IN_REQUEST:
1662                 if (!vb->prepared) {
1663                         ret = __buf_prepare(vb);
1664                         if (ret)
1665                                 return ret;
1666                 }
1667                 break;
1668         case VB2_BUF_STATE_PREPARING:
1669                 dprintk(q, 1, "buffer still being prepared\n");
1670                 return -EINVAL;
1671         default:
1672                 dprintk(q, 1, "invalid buffer state %s\n",
1673                         vb2_state_name(vb->state));
1674                 return -EINVAL;
1675         }
1676
1677         /*
1678          * Add to the queued buffers list, a buffer will stay on it until
1679          * dequeued in dqbuf.
1680          */
1681         orig_state = vb->state;
1682         list_add_tail(&vb->queued_entry, &q->queued_list);
1683         q->queued_count++;
1684         q->waiting_for_buffers = false;
1685         vb->state = VB2_BUF_STATE_QUEUED;
1686
1687         if (pb)
1688                 call_void_bufop(q, copy_timestamp, vb, pb);
1689
1690         trace_vb2_qbuf(q, vb);
1691
1692         /*
1693          * If already streaming, give the buffer to driver for processing.
1694          * If not, the buffer will be given to driver on next streamon.
1695          */
1696         if (q->start_streaming_called)
1697                 __enqueue_in_driver(vb);
1698
1699         /* Fill buffer information for the userspace */
1700         if (pb)
1701                 call_void_bufop(q, fill_user_buffer, vb, pb);
1702
1703         /*
1704          * If streamon has been called, and we haven't yet called
1705          * start_streaming() since not enough buffers were queued, and
1706          * we now have reached the minimum number of queued buffers,
1707          * then we can finally call start_streaming().
1708          */
1709         if (q->streaming && !q->start_streaming_called &&
1710             q->queued_count >= q->min_buffers_needed) {
1711                 ret = vb2_start_streaming(q);
1712                 if (ret) {
1713                         /*
1714                          * Since vb2_core_qbuf will return with an error,
1715                          * we should return it to state DEQUEUED since
1716                          * the error indicates that the buffer wasn't queued.
1717                          */
1718                         list_del(&vb->queued_entry);
1719                         q->queued_count--;
1720                         vb->state = orig_state;
1721                         return ret;
1722                 }
1723         }
1724
1725         dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
1726         return 0;
1727 }
1728 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1729
1730 /*
1731  * __vb2_wait_for_done_vb() - wait for a buffer to become available
1732  * for dequeuing
1733  *
1734  * Will sleep if required for nonblocking == false.
1735  */
1736 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1737 {
1738         /*
1739          * All operations on vb_done_list are performed under done_lock
1740          * spinlock protection. However, buffers may be removed from
1741          * it and returned to userspace only while holding both driver's
1742          * lock and the done_lock spinlock. Thus we can be sure that as
1743          * long as we hold the driver's lock, the list will remain not
1744          * empty if list_empty() check succeeds.
1745          */
1746
1747         for (;;) {
1748                 int ret;
1749
1750                 if (q->waiting_in_dqbuf) {
1751                         dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
1752                         return -EBUSY;
1753                 }
1754
1755                 if (!q->streaming) {
1756                         dprintk(q, 1, "streaming off, will not wait for buffers\n");
1757                         return -EINVAL;
1758                 }
1759
1760                 if (q->error) {
1761                         dprintk(q, 1, "Queue in error state, will not wait for buffers\n");
1762                         return -EIO;
1763                 }
1764
1765                 if (q->last_buffer_dequeued) {
1766                         dprintk(q, 3, "last buffer dequeued already, will not wait for buffers\n");
1767                         return -EPIPE;
1768                 }
1769
1770                 if (!list_empty(&q->done_list)) {
1771                         /*
1772                          * Found a buffer that we were waiting for.
1773                          */
1774                         break;
1775                 }
1776
1777                 if (nonblocking) {
1778                         dprintk(q, 3, "nonblocking and no buffers to dequeue, will not wait\n");
1779                         return -EAGAIN;
1780                 }
1781
1782                 q->waiting_in_dqbuf = 1;
1783                 /*
1784                  * We are streaming and blocking, wait for another buffer to
1785                  * become ready or for streamoff. Driver's lock is released to
1786                  * allow streamoff or qbuf to be called while waiting.
1787                  */
1788                 call_void_qop(q, wait_prepare, q);
1789
1790                 /*
1791                  * All locks have been released, it is safe to sleep now.
1792                  */
1793                 dprintk(q, 3, "will sleep waiting for buffers\n");
1794                 ret = wait_event_interruptible(q->done_wq,
1795                                 !list_empty(&q->done_list) || !q->streaming ||
1796                                 q->error);
1797
1798                 /*
1799                  * We need to reevaluate both conditions again after reacquiring
1800                  * the locks or return an error if one occurred.
1801                  */
1802                 call_void_qop(q, wait_finish, q);
1803                 q->waiting_in_dqbuf = 0;
1804                 if (ret) {
1805                         dprintk(q, 1, "sleep was interrupted\n");
1806                         return ret;
1807                 }
1808         }
1809         return 0;
1810 }
1811
1812 /*
1813  * __vb2_get_done_vb() - get a buffer ready for dequeuing
1814  *
1815  * Will sleep if required for nonblocking == false.
1816  */
1817 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1818                              void *pb, int nonblocking)
1819 {
1820         unsigned long flags;
1821         int ret = 0;
1822
1823         /*
1824          * Wait for at least one buffer to become available on the done_list.
1825          */
1826         ret = __vb2_wait_for_done_vb(q, nonblocking);
1827         if (ret)
1828                 return ret;
1829
1830         /*
1831          * Driver's lock has been held since we last verified that done_list
1832          * is not empty, so no need for another list_empty(done_list) check.
1833          */
1834         spin_lock_irqsave(&q->done_lock, flags);
1835         *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1836         /*
1837          * Only remove the buffer from done_list if all planes can be
1838          * handled. Some cases such as V4L2 file I/O and DVB have pb
1839          * == NULL; skip the check then as there's nothing to verify.
1840          */
1841         if (pb)
1842                 ret = call_bufop(q, verify_planes_array, *vb, pb);
1843         if (!ret)
1844                 list_del(&(*vb)->done_entry);
1845         spin_unlock_irqrestore(&q->done_lock, flags);
1846
1847         return ret;
1848 }
1849
1850 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1851 {
1852         if (!q->streaming) {
1853                 dprintk(q, 1, "streaming off, will not wait for buffers\n");
1854                 return -EINVAL;
1855         }
1856
1857         if (q->start_streaming_called)
1858                 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1859         return 0;
1860 }
1861 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1862
1863 /*
1864  * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1865  */
1866 static void __vb2_dqbuf(struct vb2_buffer *vb)
1867 {
1868         struct vb2_queue *q = vb->vb2_queue;
1869
1870         /* nothing to do if the buffer is already dequeued */
1871         if (vb->state == VB2_BUF_STATE_DEQUEUED)
1872                 return;
1873
1874         vb->state = VB2_BUF_STATE_DEQUEUED;
1875
1876         call_void_bufop(q, init_buffer, vb);
1877 }
1878
1879 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1880                    bool nonblocking)
1881 {
1882         struct vb2_buffer *vb = NULL;
1883         int ret;
1884
1885         ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1886         if (ret < 0)
1887                 return ret;
1888
1889         switch (vb->state) {
1890         case VB2_BUF_STATE_DONE:
1891                 dprintk(q, 3, "returning done buffer\n");
1892                 break;
1893         case VB2_BUF_STATE_ERROR:
1894                 dprintk(q, 3, "returning done buffer with errors\n");
1895                 break;
1896         default:
1897                 dprintk(q, 1, "invalid buffer state %s\n",
1898                         vb2_state_name(vb->state));
1899                 return -EINVAL;
1900         }
1901
1902         call_void_vb_qop(vb, buf_finish, vb);
1903         vb->prepared = 0;
1904
1905         if (pindex)
1906                 *pindex = vb->index;
1907
1908         /* Fill buffer information for the userspace */
1909         if (pb)
1910                 call_void_bufop(q, fill_user_buffer, vb, pb);
1911
1912         /* Remove from videobuf queue */
1913         list_del(&vb->queued_entry);
1914         q->queued_count--;
1915
1916         trace_vb2_dqbuf(q, vb);
1917
1918         /* go back to dequeued state */
1919         __vb2_dqbuf(vb);
1920
1921         if (WARN_ON(vb->req_obj.req)) {
1922                 media_request_object_unbind(&vb->req_obj);
1923                 media_request_object_put(&vb->req_obj);
1924         }
1925         if (vb->request)
1926                 media_request_put(vb->request);
1927         vb->request = NULL;
1928
1929         dprintk(q, 2, "dqbuf of buffer %d, state: %s\n",
1930                 vb->index, vb2_state_name(vb->state));
1931
1932         return 0;
1933
1934 }
1935 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
1936
1937 /*
1938  * __vb2_queue_cancel() - cancel and stop (pause) streaming
1939  *
1940  * Removes all queued buffers from driver's queue and all buffers queued by
1941  * userspace from videobuf's queue. Returns to state after reqbufs.
1942  */
1943 static void __vb2_queue_cancel(struct vb2_queue *q)
1944 {
1945         unsigned int i;
1946
1947         /*
1948          * Tell driver to stop all transactions and release all queued
1949          * buffers.
1950          */
1951         if (q->start_streaming_called)
1952                 call_void_qop(q, stop_streaming, q);
1953
1954         /*
1955          * If you see this warning, then the driver isn't cleaning up properly
1956          * in stop_streaming(). See the stop_streaming() documentation in
1957          * videobuf2-core.h for more information how buffers should be returned
1958          * to vb2 in stop_streaming().
1959          */
1960         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1961                 for (i = 0; i < q->num_buffers; ++i)
1962                         if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE) {
1963                                 pr_warn("driver bug: stop_streaming operation is leaving buf %p in active state\n",
1964                                         q->bufs[i]);
1965                                 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
1966                         }
1967                 /* Must be zero now */
1968                 WARN_ON(atomic_read(&q->owned_by_drv_count));
1969         }
1970
1971         q->streaming = 0;
1972         q->start_streaming_called = 0;
1973         q->queued_count = 0;
1974         q->error = 0;
1975         q->uses_requests = 0;
1976         q->uses_qbuf = 0;
1977
1978         /*
1979          * Remove all buffers from videobuf's list...
1980          */
1981         INIT_LIST_HEAD(&q->queued_list);
1982         /*
1983          * ...and done list; userspace will not receive any buffers it
1984          * has not already dequeued before initiating cancel.
1985          */
1986         INIT_LIST_HEAD(&q->done_list);
1987         atomic_set(&q->owned_by_drv_count, 0);
1988         wake_up_all(&q->done_wq);
1989
1990         /*
1991          * Reinitialize all buffers for next use.
1992          * Make sure to call buf_finish for any queued buffers. Normally
1993          * that's done in dqbuf, but that's not going to happen when we
1994          * cancel the whole queue. Note: this code belongs here, not in
1995          * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
1996          * call to __fill_user_buffer() after buf_finish(). That order can't
1997          * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
1998          */
1999         for (i = 0; i < q->num_buffers; ++i) {
2000                 struct vb2_buffer *vb = q->bufs[i];
2001                 struct media_request *req = vb->req_obj.req;
2002
2003                 /*
2004                  * If a request is associated with this buffer, then
2005                  * call buf_request_cancel() to give the driver to complete()
2006                  * related request objects. Otherwise those objects would
2007                  * never complete.
2008                  */
2009                 if (req) {
2010                         enum media_request_state state;
2011                         unsigned long flags;
2012
2013                         spin_lock_irqsave(&req->lock, flags);
2014                         state = req->state;
2015                         spin_unlock_irqrestore(&req->lock, flags);
2016
2017                         if (state == MEDIA_REQUEST_STATE_QUEUED)
2018                                 call_void_vb_qop(vb, buf_request_complete, vb);
2019                 }
2020
2021                 __vb2_buf_mem_finish(vb);
2022
2023                 if (vb->prepared) {
2024                         call_void_vb_qop(vb, buf_finish, vb);
2025                         vb->prepared = 0;
2026                 }
2027                 __vb2_dqbuf(vb);
2028
2029                 if (vb->req_obj.req) {
2030                         media_request_object_unbind(&vb->req_obj);
2031                         media_request_object_put(&vb->req_obj);
2032                 }
2033                 if (vb->request)
2034                         media_request_put(vb->request);
2035                 vb->request = NULL;
2036                 vb->copied_timestamp = 0;
2037         }
2038 }
2039
2040 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
2041 {
2042         int ret;
2043
2044         if (type != q->type) {
2045                 dprintk(q, 1, "invalid stream type\n");
2046                 return -EINVAL;
2047         }
2048
2049         if (q->streaming) {
2050                 dprintk(q, 3, "already streaming\n");
2051                 return 0;
2052         }
2053
2054         if (!q->num_buffers) {
2055                 dprintk(q, 1, "no buffers have been allocated\n");
2056                 return -EINVAL;
2057         }
2058
2059         if (q->num_buffers < q->min_buffers_needed) {
2060                 dprintk(q, 1, "need at least %u allocated buffers\n",
2061                                 q->min_buffers_needed);
2062                 return -EINVAL;
2063         }
2064
2065         /*
2066          * Tell driver to start streaming provided sufficient buffers
2067          * are available.
2068          */
2069         if (q->queued_count >= q->min_buffers_needed) {
2070                 ret = v4l_vb2q_enable_media_source(q);
2071                 if (ret)
2072                         return ret;
2073                 ret = vb2_start_streaming(q);
2074                 if (ret)
2075                         return ret;
2076         }
2077
2078         q->streaming = 1;
2079
2080         dprintk(q, 3, "successful\n");
2081         return 0;
2082 }
2083 EXPORT_SYMBOL_GPL(vb2_core_streamon);
2084
2085 void vb2_queue_error(struct vb2_queue *q)
2086 {
2087         q->error = 1;
2088
2089         wake_up_all(&q->done_wq);
2090 }
2091 EXPORT_SYMBOL_GPL(vb2_queue_error);
2092
2093 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
2094 {
2095         if (type != q->type) {
2096                 dprintk(q, 1, "invalid stream type\n");
2097                 return -EINVAL;
2098         }
2099
2100         /*
2101          * Cancel will pause streaming and remove all buffers from the driver
2102          * and videobuf, effectively returning control over them to userspace.
2103          *
2104          * Note that we do this even if q->streaming == 0: if you prepare or
2105          * queue buffers, and then call streamoff without ever having called
2106          * streamon, you would still expect those buffers to be returned to
2107          * their normal dequeued state.
2108          */
2109         __vb2_queue_cancel(q);
2110         q->waiting_for_buffers = !q->is_output;
2111         q->last_buffer_dequeued = false;
2112
2113         dprintk(q, 3, "successful\n");
2114         return 0;
2115 }
2116 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
2117
2118 /*
2119  * __find_plane_by_offset() - find plane associated with the given offset off
2120  */
2121 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2122                         unsigned int *_buffer, unsigned int *_plane)
2123 {
2124         struct vb2_buffer *vb;
2125         unsigned int buffer, plane;
2126
2127         /*
2128          * Go over all buffers and their planes, comparing the given offset
2129          * with an offset assigned to each plane. If a match is found,
2130          * return its buffer and plane numbers.
2131          */
2132         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2133                 vb = q->bufs[buffer];
2134
2135                 for (plane = 0; plane < vb->num_planes; ++plane) {
2136                         if (vb->planes[plane].m.offset == off) {
2137                                 *_buffer = buffer;
2138                                 *_plane = plane;
2139                                 return 0;
2140                         }
2141                 }
2142         }
2143
2144         return -EINVAL;
2145 }
2146
2147 int vb2_core_expbuf_dmabuf(struct vb2_queue *q, unsigned int type,
2148                            unsigned int index, unsigned int plane,
2149                            unsigned int flags, struct dma_buf **dmabuf)
2150 {
2151         struct vb2_buffer *vb = NULL;
2152         struct vb2_plane *vb_plane;
2153         struct dma_buf *dbuf;
2154
2155         if (q->memory != VB2_MEMORY_MMAP) {
2156                 dprintk(q, 1, "queue is not currently set up for mmap\n");
2157                 return -EINVAL;
2158         }
2159
2160         if (!q->mem_ops->get_dmabuf) {
2161                 dprintk(q, 1, "queue does not support DMA buffer exporting\n");
2162                 return -EINVAL;
2163         }
2164
2165         if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
2166                 dprintk(q, 1, "queue does support only O_CLOEXEC and access mode flags\n");
2167                 return -EINVAL;
2168         }
2169
2170         if (type != q->type) {
2171                 dprintk(q, 1, "invalid buffer type\n");
2172                 return -EINVAL;
2173         }
2174
2175         if (index >= q->num_buffers) {
2176                 dprintk(q, 1, "buffer index out of range\n");
2177                 return -EINVAL;
2178         }
2179
2180         vb = q->bufs[index];
2181
2182         if (plane >= vb->num_planes) {
2183                 dprintk(q, 1, "buffer plane out of range\n");
2184                 return -EINVAL;
2185         }
2186
2187         if (vb2_fileio_is_active(q)) {
2188                 dprintk(q, 1, "expbuf: file io in progress\n");
2189                 return -EBUSY;
2190         }
2191
2192         vb_plane = &vb->planes[plane];
2193
2194         dbuf = call_ptr_memop(get_dmabuf,
2195                               vb,
2196                               vb_plane->mem_priv,
2197                               flags & O_ACCMODE);
2198         if (IS_ERR_OR_NULL(dbuf)) {
2199                 dprintk(q, 1, "failed to export buffer %d, plane %d\n",
2200                         index, plane);
2201                 return -EINVAL;
2202         }
2203
2204         *dmabuf = dbuf;
2205         return 0;
2206 }
2207 EXPORT_SYMBOL_GPL(vb2_core_expbuf_dmabuf);
2208
2209 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
2210                     unsigned int index, unsigned int plane, unsigned int flags)
2211 {
2212         struct dma_buf *dbuf;
2213         int ret;
2214
2215         ret = vb2_core_expbuf_dmabuf(q, type, index, plane, flags, &dbuf);
2216         if (ret)
2217                 return ret;
2218
2219         ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
2220         if (ret < 0) {
2221                 dprintk(q, 3, "buffer %d, plane %d failed to export (%d)\n",
2222                         index, plane, ret);
2223                 dma_buf_put(dbuf);
2224                 return ret;
2225         }
2226
2227         dprintk(q, 3, "buffer %d, plane %d exported as %d descriptor\n",
2228                 index, plane, ret);
2229         *fd = ret;
2230
2231         return 0;
2232 }
2233 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
2234
2235 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2236 {
2237         unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2238         struct vb2_buffer *vb;
2239         unsigned int buffer = 0, plane = 0;
2240         int ret;
2241         unsigned long length;
2242
2243         if (q->memory != VB2_MEMORY_MMAP) {
2244                 dprintk(q, 1, "queue is not currently set up for mmap\n");
2245                 return -EINVAL;
2246         }
2247
2248         /*
2249          * Check memory area access mode.
2250          */
2251         if (!(vma->vm_flags & VM_SHARED)) {
2252                 dprintk(q, 1, "invalid vma flags, VM_SHARED needed\n");
2253                 return -EINVAL;
2254         }
2255         if (q->is_output) {
2256                 if (!(vma->vm_flags & VM_WRITE)) {
2257                         dprintk(q, 1, "invalid vma flags, VM_WRITE needed\n");
2258                         return -EINVAL;
2259                 }
2260         } else {
2261                 if (!(vma->vm_flags & VM_READ)) {
2262                         dprintk(q, 1, "invalid vma flags, VM_READ needed\n");
2263                         return -EINVAL;
2264                 }
2265         }
2266
2267         mutex_lock(&q->mmap_lock);
2268
2269         if (vb2_fileio_is_active(q)) {
2270                 dprintk(q, 1, "mmap: file io in progress\n");
2271                 ret = -EBUSY;
2272                 goto unlock;
2273         }
2274
2275         /*
2276          * Find the plane corresponding to the offset passed by userspace.
2277          */
2278         ret = __find_plane_by_offset(q, off, &buffer, &plane);
2279         if (ret)
2280                 goto unlock;
2281
2282         vb = q->bufs[buffer];
2283
2284         /*
2285          * MMAP requires page_aligned buffers.
2286          * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2287          * so, we need to do the same here.
2288          */
2289         length = PAGE_ALIGN(vb->planes[plane].length);
2290         if (length < (vma->vm_end - vma->vm_start)) {
2291                 dprintk(q, 1,
2292                         "MMAP invalid, as it would overflow buffer length\n");
2293                 ret = -EINVAL;
2294                 goto unlock;
2295         }
2296
2297         /*
2298          * vm_pgoff is treated in V4L2 API as a 'cookie' to select a buffer,
2299          * not as a in-buffer offset. We always want to mmap a whole buffer
2300          * from its beginning.
2301          */
2302         vma->vm_pgoff = 0;
2303
2304         ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2305
2306 unlock:
2307         mutex_unlock(&q->mmap_lock);
2308         if (ret)
2309                 return ret;
2310
2311         dprintk(q, 3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2312         return 0;
2313 }
2314 EXPORT_SYMBOL_GPL(vb2_mmap);
2315
2316 #ifndef CONFIG_MMU
2317 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2318                                     unsigned long addr,
2319                                     unsigned long len,
2320                                     unsigned long pgoff,
2321                                     unsigned long flags)
2322 {
2323         unsigned long off = pgoff << PAGE_SHIFT;
2324         struct vb2_buffer *vb;
2325         unsigned int buffer, plane;
2326         void *vaddr;
2327         int ret;
2328
2329         if (q->memory != VB2_MEMORY_MMAP) {
2330                 dprintk(q, 1, "queue is not currently set up for mmap\n");
2331                 return -EINVAL;
2332         }
2333
2334         /*
2335          * Find the plane corresponding to the offset passed by userspace.
2336          */
2337         ret = __find_plane_by_offset(q, off, &buffer, &plane);
2338         if (ret)
2339                 return ret;
2340
2341         vb = q->bufs[buffer];
2342
2343         vaddr = vb2_plane_vaddr(vb, plane);
2344         return vaddr ? (unsigned long)vaddr : -EINVAL;
2345 }
2346 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2347 #endif
2348
2349 int vb2_core_queue_init(struct vb2_queue *q)
2350 {
2351         /*
2352          * Sanity check
2353          */
2354         if (WARN_ON(!q)                   ||
2355             WARN_ON(!q->ops)              ||
2356             WARN_ON(!q->mem_ops)          ||
2357             WARN_ON(!q->type)             ||
2358             WARN_ON(!q->io_modes)         ||
2359             WARN_ON(!q->ops->queue_setup) ||
2360             WARN_ON(!q->ops->buf_queue))
2361                 return -EINVAL;
2362
2363         if (WARN_ON(q->requires_requests && !q->supports_requests))
2364                 return -EINVAL;
2365
2366         INIT_LIST_HEAD(&q->queued_list);
2367         INIT_LIST_HEAD(&q->done_list);
2368         spin_lock_init(&q->done_lock);
2369         mutex_init(&q->mmap_lock);
2370         init_waitqueue_head(&q->done_wq);
2371
2372         q->memory = VB2_MEMORY_UNKNOWN;
2373
2374         if (q->buf_struct_size == 0)
2375                 q->buf_struct_size = sizeof(struct vb2_buffer);
2376
2377         if (q->bidirectional)
2378                 q->dma_dir = DMA_BIDIRECTIONAL;
2379         else
2380                 q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
2381
2382         if (q->name[0] == '\0')
2383                 snprintf(q->name, sizeof(q->name), "%s-%p",
2384                          q->is_output ? "out" : "cap", q);
2385
2386         return 0;
2387 }
2388 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2389
2390 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2391 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2392 void vb2_core_queue_release(struct vb2_queue *q)
2393 {
2394         __vb2_cleanup_fileio(q);
2395         __vb2_queue_cancel(q);
2396         mutex_lock(&q->mmap_lock);
2397         __vb2_queue_free(q, q->num_buffers);
2398         mutex_unlock(&q->mmap_lock);
2399 }
2400 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2401
2402 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
2403                 poll_table *wait)
2404 {
2405         __poll_t req_events = poll_requested_events(wait);
2406         struct vb2_buffer *vb = NULL;
2407         unsigned long flags;
2408
2409         /*
2410          * poll_wait() MUST be called on the first invocation on all the
2411          * potential queues of interest, even if we are not interested in their
2412          * events during this first call. Failure to do so will result in
2413          * queue's events to be ignored because the poll_table won't be capable
2414          * of adding new wait queues thereafter.
2415          */
2416         poll_wait(file, &q->done_wq, wait);
2417
2418         if (!q->is_output && !(req_events & (EPOLLIN | EPOLLRDNORM)))
2419                 return 0;
2420         if (q->is_output && !(req_events & (EPOLLOUT | EPOLLWRNORM)))
2421                 return 0;
2422
2423         /*
2424          * Start file I/O emulator only if streaming API has not been used yet.
2425          */
2426         if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2427                 if (!q->is_output && (q->io_modes & VB2_READ) &&
2428                                 (req_events & (EPOLLIN | EPOLLRDNORM))) {
2429                         if (__vb2_init_fileio(q, 1))
2430                                 return EPOLLERR;
2431                 }
2432                 if (q->is_output && (q->io_modes & VB2_WRITE) &&
2433                                 (req_events & (EPOLLOUT | EPOLLWRNORM))) {
2434                         if (__vb2_init_fileio(q, 0))
2435                                 return EPOLLERR;
2436                         /*
2437                          * Write to OUTPUT queue can be done immediately.
2438                          */
2439                         return EPOLLOUT | EPOLLWRNORM;
2440                 }
2441         }
2442
2443         /*
2444          * There is nothing to wait for if the queue isn't streaming, or if the
2445          * error flag is set.
2446          */
2447         if (!vb2_is_streaming(q) || q->error)
2448                 return EPOLLERR;
2449
2450         /*
2451          * If this quirk is set and QBUF hasn't been called yet then
2452          * return EPOLLERR as well. This only affects capture queues, output
2453          * queues will always initialize waiting_for_buffers to false.
2454          * This quirk is set by V4L2 for backwards compatibility reasons.
2455          */
2456         if (q->quirk_poll_must_check_waiting_for_buffers &&
2457             q->waiting_for_buffers && (req_events & (EPOLLIN | EPOLLRDNORM)))
2458                 return EPOLLERR;
2459
2460         /*
2461          * For output streams you can call write() as long as there are fewer
2462          * buffers queued than there are buffers available.
2463          */
2464         if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2465                 return EPOLLOUT | EPOLLWRNORM;
2466
2467         if (list_empty(&q->done_list)) {
2468                 /*
2469                  * If the last buffer was dequeued from a capture queue,
2470                  * return immediately. DQBUF will return -EPIPE.
2471                  */
2472                 if (q->last_buffer_dequeued)
2473                         return EPOLLIN | EPOLLRDNORM;
2474         }
2475
2476         /*
2477          * Take first buffer available for dequeuing.
2478          */
2479         spin_lock_irqsave(&q->done_lock, flags);
2480         if (!list_empty(&q->done_list))
2481                 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2482                                         done_entry);
2483         spin_unlock_irqrestore(&q->done_lock, flags);
2484
2485         if (vb && (vb->state == VB2_BUF_STATE_DONE
2486                         || vb->state == VB2_BUF_STATE_ERROR)) {
2487                 return (q->is_output) ?
2488                                 EPOLLOUT | EPOLLWRNORM :
2489                                 EPOLLIN | EPOLLRDNORM;
2490         }
2491         return 0;
2492 }
2493 EXPORT_SYMBOL_GPL(vb2_core_poll);
2494
2495 /*
2496  * struct vb2_fileio_buf - buffer context used by file io emulator
2497  *
2498  * vb2 provides a compatibility layer and emulator of file io (read and
2499  * write) calls on top of streaming API. This structure is used for
2500  * tracking context related to the buffers.
2501  */
2502 struct vb2_fileio_buf {
2503         void *vaddr;
2504         unsigned int size;
2505         unsigned int pos;
2506         unsigned int queued:1;
2507 };
2508
2509 /*
2510  * struct vb2_fileio_data - queue context used by file io emulator
2511  *
2512  * @cur_index:  the index of the buffer currently being read from or
2513  *              written to. If equal to q->num_buffers then a new buffer
2514  *              must be dequeued.
2515  * @initial_index: in the read() case all buffers are queued up immediately
2516  *              in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2517  *              buffers. However, in the write() case no buffers are initially
2518  *              queued, instead whenever a buffer is full it is queued up by
2519  *              __vb2_perform_fileio(). Only once all available buffers have
2520  *              been queued up will __vb2_perform_fileio() start to dequeue
2521  *              buffers. This means that initially __vb2_perform_fileio()
2522  *              needs to know what buffer index to use when it is queuing up
2523  *              the buffers for the first time. That initial index is stored
2524  *              in this field. Once it is equal to q->num_buffers all
2525  *              available buffers have been queued and __vb2_perform_fileio()
2526  *              should start the normal dequeue/queue cycle.
2527  *
2528  * vb2 provides a compatibility layer and emulator of file io (read and
2529  * write) calls on top of streaming API. For proper operation it required
2530  * this structure to save the driver state between each call of the read
2531  * or write function.
2532  */
2533 struct vb2_fileio_data {
2534         unsigned int count;
2535         unsigned int type;
2536         unsigned int memory;
2537         struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2538         unsigned int cur_index;
2539         unsigned int initial_index;
2540         unsigned int q_count;
2541         unsigned int dq_count;
2542         unsigned read_once:1;
2543         unsigned write_immediately:1;
2544 };
2545
2546 /*
2547  * __vb2_init_fileio() - initialize file io emulator
2548  * @q:          videobuf2 queue
2549  * @read:       mode selector (1 means read, 0 means write)
2550  */
2551 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2552 {
2553         struct vb2_fileio_data *fileio;
2554         int i, ret;
2555         unsigned int count = 0;
2556
2557         /*
2558          * Sanity check
2559          */
2560         if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2561                     (!read && !(q->io_modes & VB2_WRITE))))
2562                 return -EINVAL;
2563
2564         /*
2565          * Check if device supports mapping buffers to kernel virtual space.
2566          */
2567         if (!q->mem_ops->vaddr)
2568                 return -EBUSY;
2569
2570         /*
2571          * Check if streaming api has not been already activated.
2572          */
2573         if (q->streaming || q->num_buffers > 0)
2574                 return -EBUSY;
2575
2576         /*
2577          * Start with count 1, driver can increase it in queue_setup()
2578          */
2579         count = 1;
2580
2581         dprintk(q, 3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2582                 (read) ? "read" : "write", count, q->fileio_read_once,
2583                 q->fileio_write_immediately);
2584
2585         fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2586         if (fileio == NULL)
2587                 return -ENOMEM;
2588
2589         fileio->read_once = q->fileio_read_once;
2590         fileio->write_immediately = q->fileio_write_immediately;
2591
2592         /*
2593          * Request buffers and use MMAP type to force driver
2594          * to allocate buffers by itself.
2595          */
2596         fileio->count = count;
2597         fileio->memory = VB2_MEMORY_MMAP;
2598         fileio->type = q->type;
2599         q->fileio = fileio;
2600         ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2601         if (ret)
2602                 goto err_kfree;
2603
2604         /*
2605          * Check if plane_count is correct
2606          * (multiplane buffers are not supported).
2607          */
2608         if (q->bufs[0]->num_planes != 1) {
2609                 ret = -EBUSY;
2610                 goto err_reqbufs;
2611         }
2612
2613         /*
2614          * Get kernel address of each buffer.
2615          */
2616         for (i = 0; i < q->num_buffers; i++) {
2617                 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2618                 if (fileio->bufs[i].vaddr == NULL) {
2619                         ret = -EINVAL;
2620                         goto err_reqbufs;
2621                 }
2622                 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2623         }
2624
2625         /*
2626          * Read mode requires pre queuing of all buffers.
2627          */
2628         if (read) {
2629                 /*
2630                  * Queue all buffers.
2631                  */
2632                 for (i = 0; i < q->num_buffers; i++) {
2633                         ret = vb2_core_qbuf(q, i, NULL, NULL);
2634                         if (ret)
2635                                 goto err_reqbufs;
2636                         fileio->bufs[i].queued = 1;
2637                 }
2638                 /*
2639                  * All buffers have been queued, so mark that by setting
2640                  * initial_index to q->num_buffers
2641                  */
2642                 fileio->initial_index = q->num_buffers;
2643                 fileio->cur_index = q->num_buffers;
2644         }
2645
2646         /*
2647          * Start streaming.
2648          */
2649         ret = vb2_core_streamon(q, q->type);
2650         if (ret)
2651                 goto err_reqbufs;
2652
2653         return ret;
2654
2655 err_reqbufs:
2656         fileio->count = 0;
2657         vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2658
2659 err_kfree:
2660         q->fileio = NULL;
2661         kfree(fileio);
2662         return ret;
2663 }
2664
2665 /*
2666  * __vb2_cleanup_fileio() - free resourced used by file io emulator
2667  * @q:          videobuf2 queue
2668  */
2669 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2670 {
2671         struct vb2_fileio_data *fileio = q->fileio;
2672
2673         if (fileio) {
2674                 vb2_core_streamoff(q, q->type);
2675                 q->fileio = NULL;
2676                 fileio->count = 0;
2677                 vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2678                 kfree(fileio);
2679                 dprintk(q, 3, "file io emulator closed\n");
2680         }
2681         return 0;
2682 }
2683
2684 /*
2685  * __vb2_perform_fileio() - perform a single file io (read or write) operation
2686  * @q:          videobuf2 queue
2687  * @data:       pointed to target userspace buffer
2688  * @count:      number of bytes to read or write
2689  * @ppos:       file handle position tracking pointer
2690  * @nonblock:   mode selector (1 means blocking calls, 0 means nonblocking)
2691  * @read:       access mode selector (1 means read, 0 means write)
2692  */
2693 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2694                 loff_t *ppos, int nonblock, int read)
2695 {
2696         struct vb2_fileio_data *fileio;
2697         struct vb2_fileio_buf *buf;
2698         bool is_multiplanar = q->is_multiplanar;
2699         /*
2700          * When using write() to write data to an output video node the vb2 core
2701          * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2702          * else is able to provide this information with the write() operation.
2703          */
2704         bool copy_timestamp = !read && q->copy_timestamp;
2705         unsigned index;
2706         int ret;
2707
2708         dprintk(q, 3, "mode %s, offset %ld, count %zd, %sblocking\n",
2709                 read ? "read" : "write", (long)*ppos, count,
2710                 nonblock ? "non" : "");
2711
2712         if (!data)
2713                 return -EINVAL;
2714
2715         if (q->waiting_in_dqbuf) {
2716                 dprintk(q, 3, "another dup()ped fd is %s\n",
2717                         read ? "reading" : "writing");
2718                 return -EBUSY;
2719         }
2720
2721         /*
2722          * Initialize emulator on first call.
2723          */
2724         if (!vb2_fileio_is_active(q)) {
2725                 ret = __vb2_init_fileio(q, read);
2726                 dprintk(q, 3, "vb2_init_fileio result: %d\n", ret);
2727                 if (ret)
2728                         return ret;
2729         }
2730         fileio = q->fileio;
2731
2732         /*
2733          * Check if we need to dequeue the buffer.
2734          */
2735         index = fileio->cur_index;
2736         if (index >= q->num_buffers) {
2737                 struct vb2_buffer *b;
2738
2739                 /*
2740                  * Call vb2_dqbuf to get buffer back.
2741                  */
2742                 ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2743                 dprintk(q, 5, "vb2_dqbuf result: %d\n", ret);
2744                 if (ret)
2745                         return ret;
2746                 fileio->dq_count += 1;
2747
2748                 fileio->cur_index = index;
2749                 buf = &fileio->bufs[index];
2750                 b = q->bufs[index];
2751
2752                 /*
2753                  * Get number of bytes filled by the driver
2754                  */
2755                 buf->pos = 0;
2756                 buf->queued = 0;
2757                 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2758                                  : vb2_plane_size(q->bufs[index], 0);
2759                 /* Compensate for data_offset on read in the multiplanar case. */
2760                 if (is_multiplanar && read &&
2761                                 b->planes[0].data_offset < buf->size) {
2762                         buf->pos = b->planes[0].data_offset;
2763                         buf->size -= buf->pos;
2764                 }
2765         } else {
2766                 buf = &fileio->bufs[index];
2767         }
2768
2769         /*
2770          * Limit count on last few bytes of the buffer.
2771          */
2772         if (buf->pos + count > buf->size) {
2773                 count = buf->size - buf->pos;
2774                 dprintk(q, 5, "reducing read count: %zd\n", count);
2775         }
2776
2777         /*
2778          * Transfer data to userspace.
2779          */
2780         dprintk(q, 3, "copying %zd bytes - buffer %d, offset %u\n",
2781                 count, index, buf->pos);
2782         if (read)
2783                 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2784         else
2785                 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2786         if (ret) {
2787                 dprintk(q, 3, "error copying data\n");
2788                 return -EFAULT;
2789         }
2790
2791         /*
2792          * Update counters.
2793          */
2794         buf->pos += count;
2795         *ppos += count;
2796
2797         /*
2798          * Queue next buffer if required.
2799          */
2800         if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2801                 struct vb2_buffer *b = q->bufs[index];
2802
2803                 /*
2804                  * Check if this is the last buffer to read.
2805                  */
2806                 if (read && fileio->read_once && fileio->dq_count == 1) {
2807                         dprintk(q, 3, "read limit reached\n");
2808                         return __vb2_cleanup_fileio(q);
2809                 }
2810
2811                 /*
2812                  * Call vb2_qbuf and give buffer to the driver.
2813                  */
2814                 b->planes[0].bytesused = buf->pos;
2815
2816                 if (copy_timestamp)
2817                         b->timestamp = ktime_get_ns();
2818                 ret = vb2_core_qbuf(q, index, NULL, NULL);
2819                 dprintk(q, 5, "vb2_dbuf result: %d\n", ret);
2820                 if (ret)
2821                         return ret;
2822
2823                 /*
2824                  * Buffer has been queued, update the status
2825                  */
2826                 buf->pos = 0;
2827                 buf->queued = 1;
2828                 buf->size = vb2_plane_size(q->bufs[index], 0);
2829                 fileio->q_count += 1;
2830                 /*
2831                  * If we are queuing up buffers for the first time, then
2832                  * increase initial_index by one.
2833                  */
2834                 if (fileio->initial_index < q->num_buffers)
2835                         fileio->initial_index++;
2836                 /*
2837                  * The next buffer to use is either a buffer that's going to be
2838                  * queued for the first time (initial_index < q->num_buffers)
2839                  * or it is equal to q->num_buffers, meaning that the next
2840                  * time we need to dequeue a buffer since we've now queued up
2841                  * all the 'first time' buffers.
2842                  */
2843                 fileio->cur_index = fileio->initial_index;
2844         }
2845
2846         /*
2847          * Return proper number of bytes processed.
2848          */
2849         if (ret == 0)
2850                 ret = count;
2851         return ret;
2852 }
2853
2854 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2855                 loff_t *ppos, int nonblocking)
2856 {
2857         return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2858 }
2859 EXPORT_SYMBOL_GPL(vb2_read);
2860
2861 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2862                 loff_t *ppos, int nonblocking)
2863 {
2864         return __vb2_perform_fileio(q, (char __user *) data, count,
2865                                                         ppos, nonblocking, 0);
2866 }
2867 EXPORT_SYMBOL_GPL(vb2_write);
2868
2869 struct vb2_threadio_data {
2870         struct task_struct *thread;
2871         vb2_thread_fnc fnc;
2872         void *priv;
2873         bool stop;
2874 };
2875
2876 static int vb2_thread(void *data)
2877 {
2878         struct vb2_queue *q = data;
2879         struct vb2_threadio_data *threadio = q->threadio;
2880         bool copy_timestamp = false;
2881         unsigned prequeue = 0;
2882         unsigned index = 0;
2883         int ret = 0;
2884
2885         if (q->is_output) {
2886                 prequeue = q->num_buffers;
2887                 copy_timestamp = q->copy_timestamp;
2888         }
2889
2890         set_freezable();
2891
2892         for (;;) {
2893                 struct vb2_buffer *vb;
2894
2895                 /*
2896                  * Call vb2_dqbuf to get buffer back.
2897                  */
2898                 if (prequeue) {
2899                         vb = q->bufs[index++];
2900                         prequeue--;
2901                 } else {
2902                         call_void_qop(q, wait_finish, q);
2903                         if (!threadio->stop)
2904                                 ret = vb2_core_dqbuf(q, &index, NULL, 0);
2905                         call_void_qop(q, wait_prepare, q);
2906                         dprintk(q, 5, "file io: vb2_dqbuf result: %d\n", ret);
2907                         if (!ret)
2908                                 vb = q->bufs[index];
2909                 }
2910                 if (ret || threadio->stop)
2911                         break;
2912                 try_to_freeze();
2913
2914                 if (vb->state != VB2_BUF_STATE_ERROR)
2915                         if (threadio->fnc(vb, threadio->priv))
2916                                 break;
2917                 call_void_qop(q, wait_finish, q);
2918                 if (copy_timestamp)
2919                         vb->timestamp = ktime_get_ns();
2920                 if (!threadio->stop)
2921                         ret = vb2_core_qbuf(q, vb->index, NULL, NULL);
2922                 call_void_qop(q, wait_prepare, q);
2923                 if (ret || threadio->stop)
2924                         break;
2925         }
2926
2927         /* Hmm, linux becomes *very* unhappy without this ... */
2928         while (!kthread_should_stop()) {
2929                 set_current_state(TASK_INTERRUPTIBLE);
2930                 schedule();
2931         }
2932         return 0;
2933 }
2934
2935 /*
2936  * This function should not be used for anything else but the videobuf2-dvb
2937  * support. If you think you have another good use-case for this, then please
2938  * contact the linux-media mailinglist first.
2939  */
2940 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
2941                      const char *thread_name)
2942 {
2943         struct vb2_threadio_data *threadio;
2944         int ret = 0;
2945
2946         if (q->threadio)
2947                 return -EBUSY;
2948         if (vb2_is_busy(q))
2949                 return -EBUSY;
2950         if (WARN_ON(q->fileio))
2951                 return -EBUSY;
2952
2953         threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
2954         if (threadio == NULL)
2955                 return -ENOMEM;
2956         threadio->fnc = fnc;
2957         threadio->priv = priv;
2958
2959         ret = __vb2_init_fileio(q, !q->is_output);
2960         dprintk(q, 3, "file io: vb2_init_fileio result: %d\n", ret);
2961         if (ret)
2962                 goto nomem;
2963         q->threadio = threadio;
2964         threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
2965         if (IS_ERR(threadio->thread)) {
2966                 ret = PTR_ERR(threadio->thread);
2967                 threadio->thread = NULL;
2968                 goto nothread;
2969         }
2970         return 0;
2971
2972 nothread:
2973         __vb2_cleanup_fileio(q);
2974 nomem:
2975         kfree(threadio);
2976         return ret;
2977 }
2978 EXPORT_SYMBOL_GPL(vb2_thread_start);
2979
2980 int vb2_thread_stop(struct vb2_queue *q)
2981 {
2982         struct vb2_threadio_data *threadio = q->threadio;
2983         int err;
2984
2985         if (threadio == NULL)
2986                 return 0;
2987         threadio->stop = true;
2988         /* Wake up all pending sleeps in the thread */
2989         vb2_queue_error(q);
2990         err = kthread_stop(threadio->thread);
2991         __vb2_cleanup_fileio(q);
2992         threadio->thread = NULL;
2993         kfree(threadio);
2994         q->threadio = NULL;
2995         return err;
2996 }
2997 EXPORT_SYMBOL_GPL(vb2_thread_stop);
2998
2999 MODULE_DESCRIPTION("Media buffer core framework");
3000 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3001 MODULE_LICENSE("GPL");