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

   1 /*
   2  * videobuf2-core.c - video buffer 2 core framework
   3  *
   4  * Copyright (C) 2010 Samsung Electronics
   5  *
   6  * Author: Pawel Osciak <pawel@osciak.com>
   7  *         Marek Szyprowski <m.szyprowski@samsung.com>
   8  *
   9  * The vb2_thread implementation was based on code from videobuf-dvb.c:
  10  *      (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation.
  15  */
  16
  17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  18
  19 #include <linux/err.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/mm.h>
  23 #include <linux/poll.h>
  24 #include <linux/slab.h>
  25 #include <linux/sched.h>
  26 #include <linux/freezer.h>
  27 #include <linux/kthread.h>
  28
  29 #include <media/videobuf2-core.h>
  30 #include <media/v4l2-mc.h>
  31
  32 #include <trace/events/vb2.h>
  33
  34 static int debug;
  35 module_param(debug, int, 0644);
  36
  37 #define dprintk(q, level, fmt, arg...)                                  \
  38         do {                                                            \
  39                 if (debug >= level)                                     \
  40                         pr_info("[%s] %s: " fmt, (q)->name, __func__,   \
  41                                 ## arg);                                \
  42         } while (0)
  43
  44 #ifdef CONFIG_VIDEO_ADV_DEBUG
  45
  46 /*
  47  * If advanced debugging is on, then count how often each op is called
  48  * successfully, which can either be per-buffer or per-queue.
  49  *
  50  * This makes it easy to check that the 'init' and 'cleanup'
  51  * (and variations thereof) stay balanced.
  52  */
  53
  54 #define log_memop(vb, op)                                               \
  55         dprintk((vb)->vb2_queue, 2, "call_memop(%d, %s)%s\n",           \
  56                 (vb)->index, #op,                                       \
  57                 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
  58
  59 #define call_memop(vb, op, args...)                                     \
  60 ({                                                                      \
  61         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  62         int err;                                                        \
  63                                                                         \
  64         log_memop(vb, op);                                              \
  65         err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0;              \
  66         if (!err)                                                       \
  67                 (vb)->cnt_mem_ ## op++;                                 \
  68         err;                                                            \
  69 })
  70
  71 #define call_ptr_memop(op, vb, args...)                                 \
  72 ({                                                                      \
  73         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  74         void *ptr;                                                      \
  75                                                                         \
  76         log_memop(vb, op);                                              \
  77         ptr = _q->mem_ops->op ? _q->mem_ops->op(vb, args) : NULL;       \
  78         if (!IS_ERR_OR_NULL(ptr))                                       \
  79                 (vb)->cnt_mem_ ## op++;                                 \
  80         ptr;                                                            \
  81 })
  82
  83 #define call_void_memop(vb, op, args...)                                \
  84 ({                                                                      \
  85         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  86                                                                         \
  87         log_memop(vb, op);                                              \
  88         if (_q->mem_ops->op)                                            \
  89                 _q->mem_ops->op(args);                                  \
  90         (vb)->cnt_mem_ ## op++;                                         \
  91 })
  92
  93 #define log_qop(q, op)                                                  \
  94         dprintk(q, 2, "call_qop(%s)%s\n", #op,                          \
  95                 (q)->ops->op ? "" : " (nop)")
  96
  97 #define call_qop(q, op, args...)                                        \
  98 ({                                                                      \
  99         int err;                                                        \
 100                                                                         \
 101         log_qop(q, op);                                                 \
 102         err = (q)->ops->op ? (q)->ops->op(args) : 0;                    \
 103         if (!err)                                                       \
 104                 (q)->cnt_ ## op++;                                      \
 105         err;                                                            \
 106 })
 107
 108 #define call_void_qop(q, op, args...)                                   \
 109 ({                                                                      \
 110         log_qop(q, op);                                                 \
 111         if ((q)->ops->op)                                               \
 112                 (q)->ops->op(args);                                     \
 113         (q)->cnt_ ## op++;                                              \
 114 })
 115
 116 #define log_vb_qop(vb, op, args...)                                     \
 117         dprintk((vb)->vb2_queue, 2, "call_vb_qop(%d, %s)%s\n",          \
 118                 (vb)->index, #op,                                       \
 119                 (vb)->vb2_queue->ops->op ? "" : " (nop)")
 120
 121 #define call_vb_qop(vb, op, args...)                                    \
 122 ({                                                                      \
 123         int err;                                                        \
 124                                                                         \
 125         log_vb_qop(vb, op);                                             \
 126         err = (vb)->vb2_queue->ops->op ?                                \
 127                 (vb)->vb2_queue->ops->op(args) : 0;                     \
 128         if (!err)                                                       \
 129                 (vb)->cnt_ ## op++;                                     \
 130         err;                                                            \
 131 })
 132
 133 #define call_void_vb_qop(vb, op, args...)                               \
 134 ({                                                                      \
 135         log_vb_qop(vb, op);                                             \
 136         if ((vb)->vb2_queue->ops->op)                                   \
 137                 (vb)->vb2_queue->ops->op(args);                         \
 138         (vb)->cnt_ ## op++;                                             \
 139 })
 140
 141 #else
 142
 143 #define call_memop(vb, op, args...)                                     \
 144         ((vb)->vb2_queue->mem_ops->op ?                                 \
 145                 (vb)->vb2_queue->mem_ops->op(args) : 0)
 146
 147 #define call_ptr_memop(op, vb, args...)                                 \
 148         ((vb)->vb2_queue->mem_ops->op ?                                 \
 149                 (vb)->vb2_queue->mem_ops->op(vb, args) : NULL)
 150
 151 #define call_void_memop(vb, op, args...)                                \
 152         do {                                                            \
 153                 if ((vb)->vb2_queue->mem_ops->op)                       \
 154                         (vb)->vb2_queue->mem_ops->op(args);             \
 155         } while (0)
 156
 157 #define call_qop(q, op, args...)                                        \
 158         ((q)->ops->op ? (q)->ops->op(args) : 0)
 159
 160 #define call_void_qop(q, op, args...)                                   \
 161         do {                                                            \
 162                 if ((q)->ops->op)                                       \
 163                         (q)->ops->op(args);                             \
 164         } while (0)
 165
 166 #define call_vb_qop(vb, op, args...)                                    \
 167         ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
 168
 169 #define call_void_vb_qop(vb, op, args...)                               \
 170         do {                                                            \
 171                 if ((vb)->vb2_queue->ops->op)                           \
 172                         (vb)->vb2_queue->ops->op(args);                 \
 173         } while (0)
 174
 175 #endif
 176
 177 #define call_bufop(q, op, args...)                                      \
 178 ({                                                                      \
 179         int ret = 0;                                                    \
 180         if (q && q->buf_ops && q->buf_ops->op)                          \
 181                 ret = q->buf_ops->op(args);                             \
 182         ret;                                                            \
 183 })
 184
 185 #define call_void_bufop(q, op, args...)                                 \
 186 ({                                                                      \
 187         if (q && q->buf_ops && q->buf_ops->op)                          \
 188                 q->buf_ops->op(args);                                   \
 189 })
 190
 191 static void __vb2_queue_cancel(struct vb2_queue *q);
 192 static void __enqueue_in_driver(struct vb2_buffer *vb);
 193
 194 static const char *vb2_state_name(enum vb2_buffer_state s)
 195 {
 196         static const char * const state_names[] = {
 197                 [VB2_BUF_STATE_DEQUEUED] = "dequeued",
 198                 [VB2_BUF_STATE_IN_REQUEST] = "in request",
 199                 [VB2_BUF_STATE_PREPARING] = "preparing",
 200                 [VB2_BUF_STATE_QUEUED] = "queued",
 201                 [VB2_BUF_STATE_ACTIVE] = "active",
 202                 [VB2_BUF_STATE_DONE] = "done",
 203                 [VB2_BUF_STATE_ERROR] = "error",
 204         };
 205
 206         if ((unsigned int)(s) < ARRAY_SIZE(state_names))
 207                 return state_names[s];
 208         return "unknown";
 209 }
 210
 211 /*
 212  * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
 213  */
 214 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
 215 {
 216         struct vb2_queue *q = vb->vb2_queue;
 217         void *mem_priv;
 218         int plane;
 219         int ret = -ENOMEM;
 220
 221         /*
 222          * Allocate memory for all planes in this buffer
 223          * NOTE: mmapped areas should be page aligned
 224          */
 225         for (plane = 0; plane < vb->num_planes; ++plane) {
 226                 /* Memops alloc requires size to be page aligned. */
 227                 unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
 228
 229                 /* Did it wrap around? */
 230                 if (size < vb->planes[plane].length)
 231                         goto free;
 232
 233                 mem_priv = call_ptr_memop(alloc,
 234                                           vb,
 235                                           q->alloc_devs[plane] ? : q->dev,
 236                                           size);
 237                 if (IS_ERR_OR_NULL(mem_priv)) {
 238                         if (mem_priv)
 239                                 ret = PTR_ERR(mem_priv);
 240                         goto free;
 241                 }
 242
 243                 /* Associate allocator private data with this plane */
 244                 vb->planes[plane].mem_priv = mem_priv;
 245         }
 246
 247         return 0;
 248 free:
 249         /* Free already allocated memory if one of the allocations failed */
 250         for (; plane > 0; --plane) {
 251                 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
 252                 vb->planes[plane - 1].mem_priv = NULL;
 253         }
 254
 255         return ret;
 256 }
 257
 258 /*
 259  * __vb2_buf_mem_free() - free memory of the given buffer
 260  */
 261 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
 262 {
 263         unsigned int plane;
 264
 265         for (plane = 0; plane < vb->num_planes; ++plane) {
 266                 call_void_memop(vb, put, vb->planes[plane].mem_priv);
 267                 vb->planes[plane].mem_priv = NULL;
 268                 dprintk(vb->vb2_queue, 3, "freed plane %d of buffer %d\n",
 269                         plane, vb->index);
 270         }
 271 }
 272
 273 /*
 274  * __vb2_buf_userptr_put() - release userspace memory associated with
 275  * a USERPTR buffer
 276  */
 277 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
 278 {
 279         unsigned int plane;
 280
 281         for (plane = 0; plane < vb->num_planes; ++plane) {
 282                 if (vb->planes[plane].mem_priv)
 283                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
 284                 vb->planes[plane].mem_priv = NULL;
 285         }
 286 }
 287
 288 /*
 289  * __vb2_plane_dmabuf_put() - release memory associated with
 290  * a DMABUF shared plane
 291  */
 292 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
 293 {
 294         if (!p->mem_priv)
 295                 return;
 296
 297         if (p->dbuf_mapped)
 298                 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
 299
 300         call_void_memop(vb, detach_dmabuf, p->mem_priv);
 301         dma_buf_put(p->dbuf);
 302         p->mem_priv = NULL;
 303         p->dbuf = NULL;
 304         p->dbuf_mapped = 0;
 305 }
 306
 307 /*
 308  * __vb2_buf_dmabuf_put() - release memory associated with
 309  * a DMABUF shared buffer
 310  */
 311 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
 312 {
 313         unsigned int plane;
 314
 315         for (plane = 0; plane < vb->num_planes; ++plane)
 316                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
 317 }
 318
 319 /*
 320  * __vb2_buf_mem_prepare() - call ->prepare() on buffer's private memory
 321  * to sync caches
 322  */
 323 static void __vb2_buf_mem_prepare(struct vb2_buffer *vb)
 324 {
 325         unsigned int plane;
 326
 327         if (vb->synced)
 328                 return;
 329
 330         vb->synced = 1;
 331         for (plane = 0; plane < vb->num_planes; ++plane)
 332                 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
 333 }
 334
 335 /*
 336  * __vb2_buf_mem_finish() - call ->finish on buffer's private memory
 337  * to sync caches
 338  */
 339 static void __vb2_buf_mem_finish(struct vb2_buffer *vb)
 340 {
 341         unsigned int plane;
 342
 343         if (!vb->synced)
 344                 return;
 345
 346         vb->synced = 0;
 347         for (plane = 0; plane < vb->num_planes; ++plane)
 348                 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
 349 }
 350
 351 /*
 352  * __setup_offsets() - setup unique offsets ("cookies") for every plane in
 353  * the buffer.
 354  */
 355 static void __setup_offsets(struct vb2_buffer *vb)
 356 {
 357         struct vb2_queue *q = vb->vb2_queue;
 358         unsigned int plane;
 359         unsigned long off = 0;
 360
 361         if (vb->index) {
 362                 struct vb2_buffer *prev = q->bufs[vb->index - 1];
 363                 struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
 364
 365                 off = PAGE_ALIGN(p->m.offset + p->length);
 366         }
 367
 368         for (plane = 0; plane < vb->num_planes; ++plane) {
 369                 vb->planes[plane].m.offset = off;
 370
 371                 dprintk(q, 3, "buffer %d, plane %d offset 0x%08lx\n",
 372                                 vb->index, plane, off);
 373
 374                 off += vb->planes[plane].length;
 375                 off = PAGE_ALIGN(off);
 376         }
 377 }
 378
 379 static void init_buffer_cache_hints(struct vb2_queue *q, struct vb2_buffer *vb)
 380 {
 381         /*
 382          * DMA exporter should take care of cache syncs, so we can avoid
 383          * explicit ->prepare()/->finish() syncs. For other ->memory types
 384          * we always need ->prepare() or/and ->finish() cache sync.
 385          */
 386         if (q->memory == VB2_MEMORY_DMABUF) {
 387                 vb->skip_cache_sync_on_finish = 1;
 388                 vb->skip_cache_sync_on_prepare = 1;
 389                 return;
 390         }
 391
 392         /*
 393          * ->finish() cache sync can be avoided when queue direction is
 394          * TO_DEVICE.
 395          */
 396         if (q->dma_dir == DMA_TO_DEVICE)
 397                 vb->skip_cache_sync_on_finish = 1;
 398 }
 399
 400 /*
 401  * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
 402  * video buffer memory for all buffers/planes on the queue and initializes the
 403  * queue
 404  *
 405  * Returns the number of buffers successfully allocated.
 406  */
 407 static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
 408                              unsigned int num_buffers, unsigned int num_planes,
 409                              const unsigned plane_sizes[VB2_MAX_PLANES])
 410 {
 411         unsigned int buffer, plane;
 412         struct vb2_buffer *vb;
 413         int ret;
 414
 415         /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
 416         num_buffers = min_t(unsigned int, num_buffers,
 417                             VB2_MAX_FRAME - q->num_buffers);
 418
 419         for (buffer = 0; buffer < num_buffers; ++buffer) {
 420                 /* Allocate videobuf buffer structures */
 421                 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
 422                 if (!vb) {
 423                         dprintk(q, 1, "memory alloc for buffer struct failed\n");
 424                         break;
 425                 }
 426
 427                 vb->state = VB2_BUF_STATE_DEQUEUED;
 428                 vb->vb2_queue = q;
 429                 vb->num_planes = num_planes;
 430                 vb->index = q->num_buffers + buffer;
 431                 vb->type = q->type;
 432                 vb->memory = memory;
 433                 init_buffer_cache_hints(q, vb);
 434                 for (plane = 0; plane < num_planes; ++plane) {
 435                         vb->planes[plane].length = plane_sizes[plane];
 436                         vb->planes[plane].min_length = plane_sizes[plane];
 437                 }
 438                 call_void_bufop(q, init_buffer, vb);
 439
 440                 q->bufs[vb->index] = vb;
 441
 442                 /* Allocate video buffer memory for the MMAP type */
 443                 if (memory == VB2_MEMORY_MMAP) {
 444                         ret = __vb2_buf_mem_alloc(vb);
 445                         if (ret) {
 446                                 dprintk(q, 1, "failed allocating memory for buffer %d\n",
 447                                         buffer);
 448                                 q->bufs[vb->index] = NULL;
 449                                 kfree(vb);
 450                                 break;
 451                         }
 452                         __setup_offsets(vb);
 453                         /*
 454                          * Call the driver-provided buffer initialization
 455                          * callback, if given. An error in initialization
 456                          * results in queue setup failure.
 457                          */
 458                         ret = call_vb_qop(vb, buf_init, vb);
 459                         if (ret) {
 460                                 dprintk(q, 1, "buffer %d %p initialization failed\n",
 461                                         buffer, vb);
 462                                 __vb2_buf_mem_free(vb);
 463                                 q->bufs[vb->index] = NULL;
 464                                 kfree(vb);
 465                                 break;
 466                         }
 467                 }
 468         }
 469
 470         dprintk(q, 3, "allocated %d buffers, %d plane(s) each\n",
 471                 buffer, num_planes);
 472
 473         return buffer;
 474 }
 475
 476 /*
 477  * __vb2_free_mem() - release all video buffer memory for a given queue
 478  */
 479 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
 480 {
 481         unsigned int buffer;
 482         struct vb2_buffer *vb;
 483
 484         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 485              ++buffer) {
 486                 vb = q->bufs[buffer];
 487                 if (!vb)
 488                         continue;
 489
 490                 /* Free MMAP buffers or release USERPTR buffers */
 491                 if (q->memory == VB2_MEMORY_MMAP)
 492                         __vb2_buf_mem_free(vb);
 493                 else if (q->memory == VB2_MEMORY_DMABUF)
 494                         __vb2_buf_dmabuf_put(vb);
 495                 else
 496                         __vb2_buf_userptr_put(vb);
 497         }
 498 }
 499
 500 /*
 501  * __vb2_queue_free() - free buffers at the end of the queue - video memory and
 502  * related information, if no buffers are left return the queue to an
 503  * uninitialized state. Might be called even if the queue has already been freed.
 504  */
 505 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
 506 {
 507         unsigned int buffer;
 508
 509         /*
 510          * Sanity check: when preparing a buffer the queue lock is released for
 511          * a short while (see __buf_prepare for the details), which would allow
 512          * a race with a reqbufs which can call this function. Removing the
 513          * buffers from underneath __buf_prepare is obviously a bad idea, so we
 514          * check if any of the buffers is in the state PREPARING, and if so we
 515          * just return -EAGAIN.
 516          */
 517         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 518              ++buffer) {
 519                 if (q->bufs[buffer] == NULL)
 520                         continue;
 521                 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
 522                         dprintk(q, 1, "preparing buffers, cannot free\n");
 523                         return -EAGAIN;
 524                 }
 525         }
 526
 527         /* Call driver-provided cleanup function for each buffer, if provided */
 528         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 529              ++buffer) {
 530                 struct vb2_buffer *vb = q->bufs[buffer];
 531
 532                 if (vb && vb->planes[0].mem_priv)
 533                         call_void_vb_qop(vb, buf_cleanup, vb);
 534         }
 535
 536         /* Release video buffer memory */
 537         __vb2_free_mem(q, buffers);
 538
 539 #ifdef CONFIG_VIDEO_ADV_DEBUG
 540         /*
 541          * Check that all the calls were balances during the life-time of this
 542          * queue. If not (or if the debug level is 1 or up), then dump the
 543          * counters to the kernel log.
 544          */
 545         if (q->num_buffers) {
 546                 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
 547                                   q->cnt_wait_prepare != q->cnt_wait_finish;
 548
 549                 if (unbalanced || debug) {
 550                         pr_info("counters for queue %p:%s\n", q,
 551                                 unbalanced ? " UNBALANCED!" : "");
 552                         pr_info("     setup: %u start_streaming: %u stop_streaming: %u\n",
 553                                 q->cnt_queue_setup, q->cnt_start_streaming,
 554                                 q->cnt_stop_streaming);
 555                         pr_info("     wait_prepare: %u wait_finish: %u\n",
 556                                 q->cnt_wait_prepare, q->cnt_wait_finish);
 557                 }
 558                 q->cnt_queue_setup = 0;
 559                 q->cnt_wait_prepare = 0;
 560                 q->cnt_wait_finish = 0;
 561                 q->cnt_start_streaming = 0;
 562                 q->cnt_stop_streaming = 0;
 563         }
 564         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 565                 struct vb2_buffer *vb = q->bufs[buffer];
 566                 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
 567                                   vb->cnt_mem_prepare != vb->cnt_mem_finish ||
 568                                   vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
 569                                   vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
 570                                   vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
 571                                   vb->cnt_buf_queue != vb->cnt_buf_done ||
 572                                   vb->cnt_buf_prepare != vb->cnt_buf_finish ||
 573                                   vb->cnt_buf_init != vb->cnt_buf_cleanup;
 574
 575                 if (unbalanced || debug) {
 576                         pr_info("   counters for queue %p, buffer %d:%s\n",
 577                                 q, buffer, unbalanced ? " UNBALANCED!" : "");
 578                         pr_info("     buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
 579                                 vb->cnt_buf_init, vb->cnt_buf_cleanup,
 580                                 vb->cnt_buf_prepare, vb->cnt_buf_finish);
 581                         pr_info("     buf_out_validate: %u buf_queue: %u buf_done: %u buf_request_complete: %u\n",
 582                                 vb->cnt_buf_out_validate, vb->cnt_buf_queue,
 583                                 vb->cnt_buf_done, vb->cnt_buf_request_complete);
 584                         pr_info("     alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
 585                                 vb->cnt_mem_alloc, vb->cnt_mem_put,
 586                                 vb->cnt_mem_prepare, vb->cnt_mem_finish,
 587                                 vb->cnt_mem_mmap);
 588                         pr_info("     get_userptr: %u put_userptr: %u\n",
 589                                 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
 590                         pr_info("     attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
 591                                 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
 592                                 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
 593                         pr_info("     get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
 594                                 vb->cnt_mem_get_dmabuf,
 595                                 vb->cnt_mem_num_users,
 596                                 vb->cnt_mem_vaddr,
 597                                 vb->cnt_mem_cookie);
 598                 }
 599         }
 600 #endif
 601
 602         /* Free videobuf buffers */
 603         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 604              ++buffer) {
 605                 kfree(q->bufs[buffer]);
 606                 q->bufs[buffer] = NULL;
 607         }
 608
 609         q->num_buffers -= buffers;
 610         if (!q->num_buffers) {
 611                 q->memory = VB2_MEMORY_UNKNOWN;
 612                 INIT_LIST_HEAD(&q->queued_list);
 613         }
 614         return 0;
 615 }
 616
 617 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
 618 {
 619         unsigned int plane;
 620         for (plane = 0; plane < vb->num_planes; ++plane) {
 621                 void *mem_priv = vb->planes[plane].mem_priv;
 622                 /*
 623                  * If num_users() has not been provided, call_memop
 624                  * will return 0, apparently nobody cares about this
 625                  * case anyway. If num_users() returns more than 1,
 626                  * we are not the only user of the plane's memory.
 627                  */
 628                 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
 629                         return true;
 630         }
 631         return false;
 632 }
 633 EXPORT_SYMBOL(vb2_buffer_in_use);
 634
 635 /*
 636  * __buffers_in_use() - return true if any buffers on the queue are in use and
 637  * the queue cannot be freed (by the means of REQBUFS(0)) call
 638  */
 639 static bool __buffers_in_use(struct vb2_queue *q)
 640 {
 641         unsigned int buffer;
 642         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 643                 if (vb2_buffer_in_use(q, q->bufs[buffer]))
 644                         return true;
 645         }
 646         return false;
 647 }
 648
 649 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
 650 {
 651         call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
 652 }
 653 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
 654
 655 /*
 656  * __verify_userptr_ops() - verify that all memory operations required for
 657  * USERPTR queue type have been provided
 658  */
 659 static int __verify_userptr_ops(struct vb2_queue *q)
 660 {
 661         if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
 662             !q->mem_ops->put_userptr)
 663                 return -EINVAL;
 664
 665         return 0;
 666 }
 667
 668 /*
 669  * __verify_mmap_ops() - verify that all memory operations required for
 670  * MMAP queue type have been provided
 671  */
 672 static int __verify_mmap_ops(struct vb2_queue *q)
 673 {
 674         if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
 675             !q->mem_ops->put || !q->mem_ops->mmap)
 676                 return -EINVAL;
 677
 678         return 0;
 679 }
 680
 681 /*
 682  * __verify_dmabuf_ops() - verify that all memory operations required for
 683  * DMABUF queue type have been provided
 684  */
 685 static int __verify_dmabuf_ops(struct vb2_queue *q)
 686 {
 687         if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
 688             !q->mem_ops->detach_dmabuf  || !q->mem_ops->map_dmabuf ||
 689             !q->mem_ops->unmap_dmabuf)
 690                 return -EINVAL;
 691
 692         return 0;
 693 }
 694
 695 int vb2_verify_memory_type(struct vb2_queue *q,
 696                 enum vb2_memory memory, unsigned int type)
 697 {
 698         if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
 699             memory != VB2_MEMORY_DMABUF) {
 700                 dprintk(q, 1, "unsupported memory type\n");
 701                 return -EINVAL;
 702         }
 703
 704         if (type != q->type) {
 705                 dprintk(q, 1, "requested type is incorrect\n");
 706                 return -EINVAL;
 707         }
 708
 709         /*
 710          * Make sure all the required memory ops for given memory type
 711          * are available.
 712          */
 713         if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
 714                 dprintk(q, 1, "MMAP for current setup unsupported\n");
 715                 return -EINVAL;
 716         }
 717
 718         if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
 719                 dprintk(q, 1, "USERPTR for current setup unsupported\n");
 720                 return -EINVAL;
 721         }
 722
 723         if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
 724                 dprintk(q, 1, "DMABUF for current setup unsupported\n");
 725                 return -EINVAL;
 726         }
 727
 728         /*
 729          * Place the busy tests at the end: -EBUSY can be ignored when
 730          * create_bufs is called with count == 0, but count == 0 should still
 731          * do the memory and type validation.
 732          */
 733         if (vb2_fileio_is_active(q)) {
 734                 dprintk(q, 1, "file io in progress\n");
 735                 return -EBUSY;
 736         }
 737         return 0;
 738 }
 739 EXPORT_SYMBOL(vb2_verify_memory_type);
 740
 741 static void set_queue_coherency(struct vb2_queue *q, bool non_coherent_mem)
 742 {
 743         q->non_coherent_mem = 0;
 744
 745         if (!vb2_queue_allows_cache_hints(q))
 746                 return;
 747         q->non_coherent_mem = non_coherent_mem;
 748 }
 749
 750 static bool verify_coherency_flags(struct vb2_queue *q, bool non_coherent_mem)
 751 {
 752         if (non_coherent_mem != q->non_coherent_mem) {
 753                 dprintk(q, 1, "memory coherency model mismatch\n");
 754                 return false;
 755         }
 756         return true;
 757 }
 758
 759 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 760                      unsigned int flags, unsigned int *count)
 761 {
 762         unsigned int num_buffers, allocated_buffers, num_planes = 0;
 763         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 764         bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
 765         unsigned int i;
 766         int ret;
 767
 768         if (q->streaming) {
 769                 dprintk(q, 1, "streaming active\n");
 770                 return -EBUSY;
 771         }
 772
 773         if (q->waiting_in_dqbuf && *count) {
 774                 dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
 775                 return -EBUSY;
 776         }
 777
 778         if (*count == 0 || q->num_buffers != 0 ||
 779             (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory) ||
 780             !verify_coherency_flags(q, non_coherent_mem)) {
 781                 /*
 782                  * We already have buffers allocated, so first check if they
 783                  * are not in use and can be freed.
 784                  */
 785                 mutex_lock(&q->mmap_lock);
 786                 if (debug && q->memory == VB2_MEMORY_MMAP &&
 787                     __buffers_in_use(q))
 788                         dprintk(q, 1, "memory in use, orphaning buffers\n");
 789
 790                 /*
 791                  * Call queue_cancel to clean up any buffers in the
 792                  * QUEUED state which is possible if buffers were prepared or
 793                  * queued without ever calling STREAMON.
 794                  */
 795                 __vb2_queue_cancel(q);
 796                 ret = __vb2_queue_free(q, q->num_buffers);
 797                 mutex_unlock(&q->mmap_lock);
 798                 if (ret)
 799                         return ret;
 800
 801                 /*
 802                  * In case of REQBUFS(0) return immediately without calling
 803                  * driver's queue_setup() callback and allocating resources.
 804                  */
 805                 if (*count == 0)
 806                         return 0;
 807         }
 808
 809         /*
 810          * Make sure the requested values and current defaults are sane.
 811          */
 812         WARN_ON(q->min_buffers_needed > VB2_MAX_FRAME);
 813         num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);
 814         num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);
 815         memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 816         q->memory = memory;
 817         set_queue_coherency(q, non_coherent_mem);
 818
 819         /*
 820          * Ask the driver how many buffers and planes per buffer it requires.
 821          * Driver also sets the size and allocator context for each plane.
 822          */
 823         ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
 824                        plane_sizes, q->alloc_devs);
 825         if (ret)
 826                 return ret;
 827
 828         /* Check that driver has set sane values */
 829         if (WARN_ON(!num_planes))
 830                 return -EINVAL;
 831
 832         for (i = 0; i < num_planes; i++)
 833                 if (WARN_ON(!plane_sizes[i]))
 834                         return -EINVAL;
 835
 836         /* Finally, allocate buffers and video memory */
 837         allocated_buffers =
 838                 __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
 839         if (allocated_buffers == 0) {
 840                 dprintk(q, 1, "memory allocation failed\n");
 841                 return -ENOMEM;
 842         }
 843
 844         /*
 845          * There is no point in continuing if we can't allocate the minimum
 846          * number of buffers needed by this vb2_queue.
 847          */
 848         if (allocated_buffers < q->min_buffers_needed)
 849                 ret = -ENOMEM;
 850
 851         /*
 852          * Check if driver can handle the allocated number of buffers.
 853          */
 854         if (!ret && allocated_buffers < num_buffers) {
 855                 num_buffers = allocated_buffers;
 856                 /*
 857                  * num_planes is set by the previous queue_setup(), but since it
 858                  * signals to queue_setup() whether it is called from create_bufs()
 859                  * vs reqbufs() we zero it here to signal that queue_setup() is
 860                  * called for the reqbufs() case.
 861                  */
 862                 num_planes = 0;
 863
 864                 ret = call_qop(q, queue_setup, q, &num_buffers,
 865                                &num_planes, plane_sizes, q->alloc_devs);
 866
 867                 if (!ret && allocated_buffers < num_buffers)
 868                         ret = -ENOMEM;
 869
 870                 /*
 871                  * Either the driver has accepted a smaller number of buffers,
 872                  * or .queue_setup() returned an error
 873                  */
 874         }
 875
 876         mutex_lock(&q->mmap_lock);
 877         q->num_buffers = allocated_buffers;
 878
 879         if (ret < 0) {
 880                 /*
 881                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 882                  * from q->num_buffers.
 883                  */
 884                 __vb2_queue_free(q, allocated_buffers);
 885                 mutex_unlock(&q->mmap_lock);
 886                 return ret;
 887         }
 888         mutex_unlock(&q->mmap_lock);
 889
 890         /*
 891          * Return the number of successfully allocated buffers
 892          * to the userspace.
 893          */
 894         *count = allocated_buffers;
 895         q->waiting_for_buffers = !q->is_output;
 896
 897         return 0;
 898 }
 899 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
 900
 901 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 902                          unsigned int flags, unsigned int *count,
 903                          unsigned int requested_planes,
 904                          const unsigned int requested_sizes[])
 905 {
 906         unsigned int num_planes = 0, num_buffers, allocated_buffers;
 907         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 908         bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
 909         int ret;
 910
 911         if (q->num_buffers == VB2_MAX_FRAME) {
 912                 dprintk(q, 1, "maximum number of buffers already allocated\n");
 913                 return -ENOBUFS;
 914         }
 915
 916         if (!q->num_buffers) {
 917                 if (q->waiting_in_dqbuf && *count) {
 918                         dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
 919                         return -EBUSY;
 920                 }
 921                 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 922                 q->memory = memory;
 923                 q->waiting_for_buffers = !q->is_output;
 924                 set_queue_coherency(q, non_coherent_mem);
 925         } else {
 926                 if (q->memory != memory) {
 927                         dprintk(q, 1, "memory model mismatch\n");
 928                         return -EINVAL;
 929                 }
 930                 if (!verify_coherency_flags(q, non_coherent_mem))
 931                         return -EINVAL;
 932         }
 933
 934         num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
 935
 936         if (requested_planes && requested_sizes) {
 937                 num_planes = requested_planes;
 938                 memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
 939         }
 940
 941         /*
 942          * Ask the driver, whether the requested number of buffers, planes per
 943          * buffer and their sizes are acceptable
 944          */
 945         ret = call_qop(q, queue_setup, q, &num_buffers,
 946                        &num_planes, plane_sizes, q->alloc_devs);
 947         if (ret)
 948                 return ret;
 949
 950         /* Finally, allocate buffers and video memory */
 951         allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
 952                                 num_planes, plane_sizes);
 953         if (allocated_buffers == 0) {
 954                 dprintk(q, 1, "memory allocation failed\n");
 955                 return -ENOMEM;
 956         }
 957
 958         /*
 959          * Check if driver can handle the so far allocated number of buffers.
 960          */
 961         if (allocated_buffers < num_buffers) {
 962                 num_buffers = allocated_buffers;
 963
 964                 /*
 965                  * q->num_buffers contains the total number of buffers, that the
 966                  * queue driver has set up
 967                  */
 968                 ret = call_qop(q, queue_setup, q, &num_buffers,
 969                                &num_planes, plane_sizes, q->alloc_devs);
 970
 971                 if (!ret && allocated_buffers < num_buffers)
 972                         ret = -ENOMEM;
 973
 974                 /*
 975                  * Either the driver has accepted a smaller number of buffers,
 976                  * or .queue_setup() returned an error
 977                  */
 978         }
 979
 980         mutex_lock(&q->mmap_lock);
 981         q->num_buffers += allocated_buffers;
 982
 983         if (ret < 0) {
 984                 /*
 985                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 986                  * from q->num_buffers.
 987                  */
 988                 __vb2_queue_free(q, allocated_buffers);
 989                 mutex_unlock(&q->mmap_lock);
 990                 return -ENOMEM;
 991         }
 992         mutex_unlock(&q->mmap_lock);
 993
 994         /*
 995          * Return the number of successfully allocated buffers
 996          * to the userspace.
 997          */
 998         *count = allocated_buffers;
 999
1000         return 0;
1001 }
1002 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
1003
1004 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
1005 {
1006         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1007                 return NULL;
1008
1009         return call_ptr_memop(vaddr, vb, vb->planes[plane_no].mem_priv);
1010
1011 }
1012 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
1013
1014 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
1015 {
1016         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1017                 return NULL;
1018
1019         return call_ptr_memop(cookie, vb, vb->planes[plane_no].mem_priv);
1020 }
1021 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
1022
1023 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
1024 {
1025         struct vb2_queue *q = vb->vb2_queue;
1026         unsigned long flags;
1027
1028         if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
1029                 return;
1030
1031         if (WARN_ON(state != VB2_BUF_STATE_DONE &&
1032                     state != VB2_BUF_STATE_ERROR &&
1033                     state != VB2_BUF_STATE_QUEUED))
1034                 state = VB2_BUF_STATE_ERROR;
1035
1036 #ifdef CONFIG_VIDEO_ADV_DEBUG
1037         /*
1038          * Although this is not a callback, it still does have to balance
1039          * with the buf_queue op. So update this counter manually.
1040          */
1041         vb->cnt_buf_done++;
1042 #endif
1043         dprintk(q, 4, "done processing on buffer %d, state: %s\n",
1044                 vb->index, vb2_state_name(state));
1045
1046         if (state != VB2_BUF_STATE_QUEUED)
1047                 __vb2_buf_mem_finish(vb);
1048
1049         spin_lock_irqsave(&q->done_lock, flags);
1050         if (state == VB2_BUF_STATE_QUEUED) {
1051                 vb->state = VB2_BUF_STATE_QUEUED;
1052         } else {
1053                 /* Add the buffer to the done buffers list */
1054                 list_add_tail(&vb->done_entry, &q->done_list);
1055                 vb->state = state;
1056         }
1057         atomic_dec(&q->owned_by_drv_count);
1058
1059         if (state != VB2_BUF_STATE_QUEUED && vb->req_obj.req) {
1060                 media_request_object_unbind(&vb->req_obj);
1061                 media_request_object_put(&vb->req_obj);
1062         }
1063
1064         spin_unlock_irqrestore(&q->done_lock, flags);
1065
1066         trace_vb2_buf_done(q, vb);
1067
1068         switch (state) {
1069         case VB2_BUF_STATE_QUEUED:
1070                 return;
1071         default:
1072                 /* Inform any processes that may be waiting for buffers */
1073                 wake_up(&q->done_wq);
1074                 break;
1075         }
1076 }
1077 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1078
1079 void vb2_discard_done(struct vb2_queue *q)
1080 {
1081         struct vb2_buffer *vb;
1082         unsigned long flags;
1083
1084         spin_lock_irqsave(&q->done_lock, flags);
1085         list_for_each_entry(vb, &q->done_list, done_entry)
1086                 vb->state = VB2_BUF_STATE_ERROR;
1087         spin_unlock_irqrestore(&q->done_lock, flags);
1088 }
1089 EXPORT_SYMBOL_GPL(vb2_discard_done);
1090
1091 /*
1092  * __prepare_mmap() - prepare an MMAP buffer
1093  */
1094 static int __prepare_mmap(struct vb2_buffer *vb)
1095 {
1096         int ret = 0;
1097
1098         ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1099                          vb, vb->planes);
1100         return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
1101 }
1102
1103 /*
1104  * __prepare_userptr() - prepare a USERPTR buffer
1105  */
1106 static int __prepare_userptr(struct vb2_buffer *vb)
1107 {
1108         struct vb2_plane planes[VB2_MAX_PLANES];
1109         struct vb2_queue *q = vb->vb2_queue;
1110         void *mem_priv;
1111         unsigned int plane;
1112         int ret = 0;
1113         bool reacquired = vb->planes[0].mem_priv == NULL;
1114
1115         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1116         /* Copy relevant information provided by the userspace */
1117         ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1118                          vb, planes);
1119         if (ret)
1120                 return ret;
1121
1122         for (plane = 0; plane < vb->num_planes; ++plane) {
1123                 /* Skip the plane if already verified */
1124                 if (vb->planes[plane].m.userptr &&
1125                         vb->planes[plane].m.userptr == planes[plane].m.userptr
1126                         && vb->planes[plane].length == planes[plane].length)
1127                         continue;
1128
1129                 dprintk(q, 3, "userspace address for plane %d changed, reacquiring memory\n",
1130                         plane);
1131
1132                 /* Check if the provided plane buffer is large enough */
1133                 if (planes[plane].length < vb->planes[plane].min_length) {
1134                         dprintk(q, 1, "provided buffer size %u is less than setup size %u for plane %d\n",
1135                                                 planes[plane].length,
1136                                                 vb->planes[plane].min_length,
1137                                                 plane);
1138                         ret = -EINVAL;
1139                         goto err;
1140                 }
1141
1142                 /* Release previously acquired memory if present */
1143                 if (vb->planes[plane].mem_priv) {
1144                         if (!reacquired) {
1145                                 reacquired = true;
1146                                 vb->copied_timestamp = 0;
1147                                 call_void_vb_qop(vb, buf_cleanup, vb);
1148                         }
1149                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1150                 }
1151
1152                 vb->planes[plane].mem_priv = NULL;
1153                 vb->planes[plane].bytesused = 0;
1154                 vb->planes[plane].length = 0;
1155                 vb->planes[plane].m.userptr = 0;
1156                 vb->planes[plane].data_offset = 0;
1157
1158                 /* Acquire each plane's memory */
1159                 mem_priv = call_ptr_memop(get_userptr,
1160                                           vb,
1161                                           q->alloc_devs[plane] ? : q->dev,
1162                                           planes[plane].m.userptr,
1163                                           planes[plane].length);
1164                 if (IS_ERR(mem_priv)) {
1165                         dprintk(q, 1, "failed acquiring userspace memory for plane %d\n",
1166                                 plane);
1167                         ret = PTR_ERR(mem_priv);
1168                         goto err;
1169                 }
1170                 vb->planes[plane].mem_priv = mem_priv;
1171         }
1172
1173         /*
1174          * Now that everything is in order, copy relevant information
1175          * provided by userspace.
1176          */
1177         for (plane = 0; plane < vb->num_planes; ++plane) {
1178                 vb->planes[plane].bytesused = planes[plane].bytesused;
1179                 vb->planes[plane].length = planes[plane].length;
1180                 vb->planes[plane].m.userptr = planes[plane].m.userptr;
1181                 vb->planes[plane].data_offset = planes[plane].data_offset;
1182         }
1183
1184         if (reacquired) {
1185                 /*
1186                  * One or more planes changed, so we must call buf_init to do
1187                  * the driver-specific initialization on the newly acquired
1188                  * buffer, if provided.
1189                  */
1190                 ret = call_vb_qop(vb, buf_init, vb);
1191                 if (ret) {
1192                         dprintk(q, 1, "buffer initialization failed\n");
1193                         goto err;
1194                 }
1195         }
1196
1197         ret = call_vb_qop(vb, buf_prepare, vb);
1198         if (ret) {
1199                 dprintk(q, 1, "buffer preparation failed\n");
1200                 call_void_vb_qop(vb, buf_cleanup, vb);
1201                 goto err;
1202         }
1203
1204         return 0;
1205 err:
1206         /* In case of errors, release planes that were already acquired */
1207         for (plane = 0; plane < vb->num_planes; ++plane) {
1208                 if (vb->planes[plane].mem_priv)
1209                         call_void_memop(vb, put_userptr,
1210                                 vb->planes[plane].mem_priv);
1211                 vb->planes[plane].mem_priv = NULL;
1212                 vb->planes[plane].m.userptr = 0;
1213                 vb->planes[plane].length = 0;
1214         }
1215
1216         return ret;
1217 }
1218
1219 /*
1220  * __prepare_dmabuf() - prepare a DMABUF buffer
1221  */
1222 static int __prepare_dmabuf(struct vb2_buffer *vb)
1223 {
1224         struct vb2_plane planes[VB2_MAX_PLANES];
1225         struct vb2_queue *q = vb->vb2_queue;
1226         void *mem_priv;
1227         unsigned int plane;
1228         int ret = 0;
1229         bool reacquired = vb->planes[0].mem_priv == NULL;
1230
1231         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1232         /* Copy relevant information provided by the userspace */
1233         ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1234                          vb, planes);
1235         if (ret)
1236                 return ret;
1237
1238         for (plane = 0; plane < vb->num_planes; ++plane) {
1239                 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1240
1241                 if (IS_ERR_OR_NULL(dbuf)) {
1242                         dprintk(q, 1, "invalid dmabuf fd for plane %d\n",
1243                                 plane);
1244                         ret = -EINVAL;
1245                         goto err;
1246                 }
1247
1248                 /* use DMABUF size if length is not provided */
1249                 if (planes[plane].length == 0)
1250                         planes[plane].length = dbuf->size;
1251
1252                 if (planes[plane].length < vb->planes[plane].min_length) {
1253                         dprintk(q, 1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
1254                                 planes[plane].length, plane,
1255                                 vb->planes[plane].min_length);
1256                         dma_buf_put(dbuf);
1257                         ret = -EINVAL;
1258                         goto err;
1259                 }
1260
1261                 /* Skip the plane if already verified */
1262                 if (dbuf == vb->planes[plane].dbuf &&
1263                         vb->planes[plane].length == planes[plane].length) {
1264                         dma_buf_put(dbuf);
1265                         continue;
1266                 }
1267
1268                 dprintk(q, 3, "buffer for plane %d changed\n", plane);
1269
1270                 if (!reacquired) {
1271                         reacquired = true;
1272                         vb->copied_timestamp = 0;
1273                         call_void_vb_qop(vb, buf_cleanup, vb);
1274                 }
1275
1276                 /* Release previously acquired memory if present */
1277                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1278                 vb->planes[plane].bytesused = 0;
1279                 vb->planes[plane].length = 0;
1280                 vb->planes[plane].m.fd = 0;
1281                 vb->planes[plane].data_offset = 0;
1282
1283                 /* Acquire each plane's memory */
1284                 mem_priv = call_ptr_memop(attach_dmabuf,
1285                                           vb,
1286                                           q->alloc_devs[plane] ? : q->dev,
1287                                           dbuf,
1288                                           planes[plane].length);
1289                 if (IS_ERR(mem_priv)) {
1290                         dprintk(q, 1, "failed to attach dmabuf\n");
1291                         ret = PTR_ERR(mem_priv);
1292                         dma_buf_put(dbuf);
1293                         goto err;
1294                 }
1295
1296                 vb->planes[plane].dbuf = dbuf;
1297                 vb->planes[plane].mem_priv = mem_priv;
1298         }
1299
1300         /*
1301          * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1302          * here instead just before the DMA, while queueing the buffer(s) so
1303          * userspace knows sooner rather than later if the dma-buf map fails.
1304          */
1305         for (plane = 0; plane < vb->num_planes; ++plane) {
1306                 if (vb->planes[plane].dbuf_mapped)
1307                         continue;
1308
1309                 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1310                 if (ret) {
1311                         dprintk(q, 1, "failed to map dmabuf for plane %d\n",
1312                                 plane);
1313                         goto err;
1314                 }
1315                 vb->planes[plane].dbuf_mapped = 1;
1316         }
1317
1318         /*
1319          * Now that everything is in order, copy relevant information
1320          * provided by userspace.
1321          */
1322         for (plane = 0; plane < vb->num_planes; ++plane) {
1323                 vb->planes[plane].bytesused = planes[plane].bytesused;
1324                 vb->planes[plane].length = planes[plane].length;
1325                 vb->planes[plane].m.fd = planes[plane].m.fd;
1326                 vb->planes[plane].data_offset = planes[plane].data_offset;
1327         }
1328
1329         if (reacquired) {
1330                 /*
1331                  * Call driver-specific initialization on the newly acquired buffer,
1332                  * if provided.
1333                  */
1334                 ret = call_vb_qop(vb, buf_init, vb);
1335                 if (ret) {
1336                         dprintk(q, 1, "buffer initialization failed\n");
1337                         goto err;
1338                 }
1339         }
1340
1341         ret = call_vb_qop(vb, buf_prepare, vb);
1342         if (ret) {
1343                 dprintk(q, 1, "buffer preparation failed\n");
1344                 call_void_vb_qop(vb, buf_cleanup, vb);
1345                 goto err;
1346         }
1347
1348         return 0;
1349 err:
1350         /* In case of errors, release planes that were already acquired */
1351         __vb2_buf_dmabuf_put(vb);
1352
1353         return ret;
1354 }
1355
1356 /*
1357  * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1358  */
1359 static void __enqueue_in_driver(struct vb2_buffer *vb)
1360 {
1361         struct vb2_queue *q = vb->vb2_queue;
1362
1363         vb->state = VB2_BUF_STATE_ACTIVE;
1364         atomic_inc(&q->owned_by_drv_count);
1365
1366         trace_vb2_buf_queue(q, vb);
1367
1368         call_void_vb_qop(vb, buf_queue, vb);
1369 }
1370
1371 static int __buf_prepare(struct vb2_buffer *vb)
1372 {
1373         struct vb2_queue *q = vb->vb2_queue;
1374         enum vb2_buffer_state orig_state = vb->state;
1375         int ret;
1376
1377         if (q->error) {
1378                 dprintk(q, 1, "fatal error occurred on queue\n");
1379                 return -EIO;
1380         }
1381
1382         if (vb->prepared)
1383                 return 0;
1384         WARN_ON(vb->synced);
1385
1386         if (q->is_output) {
1387                 ret = call_vb_qop(vb, buf_out_validate, vb);
1388                 if (ret) {
1389                         dprintk(q, 1, "buffer validation failed\n");
1390                         return ret;
1391                 }
1392         }
1393
1394         vb->state = VB2_BUF_STATE_PREPARING;
1395
1396         switch (q->memory) {
1397         case VB2_MEMORY_MMAP:
1398                 ret = __prepare_mmap(vb);
1399                 break;
1400         case VB2_MEMORY_USERPTR:
1401                 ret = __prepare_userptr(vb);
1402                 break;
1403         case VB2_MEMORY_DMABUF:
1404                 ret = __prepare_dmabuf(vb);
1405                 break;
1406         default:
1407                 WARN(1, "Invalid queue type\n");
1408                 ret = -EINVAL;
1409                 break;
1410         }
1411
1412         if (ret) {
1413                 dprintk(q, 1, "buffer preparation failed: %d\n", ret);
1414                 vb->state = orig_state;
1415                 return ret;
1416         }
1417
1418         __vb2_buf_mem_prepare(vb);
1419         vb->prepared = 1;
1420         vb->state = orig_state;
1421
1422         return 0;
1423 }
1424
1425 static int vb2_req_prepare(struct media_request_object *obj)
1426 {
1427         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1428         int ret;
1429
1430         if (WARN_ON(vb->state != VB2_BUF_STATE_IN_REQUEST))
1431                 return -EINVAL;
1432
1433         mutex_lock(vb->vb2_queue->lock);
1434         ret = __buf_prepare(vb);
1435         mutex_unlock(vb->vb2_queue->lock);
1436         return ret;
1437 }
1438
1439 static void __vb2_dqbuf(struct vb2_buffer *vb);
1440
1441 static void vb2_req_unprepare(struct media_request_object *obj)
1442 {
1443         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1444
1445         mutex_lock(vb->vb2_queue->lock);
1446         __vb2_dqbuf(vb);
1447         vb->state = VB2_BUF_STATE_IN_REQUEST;
1448         mutex_unlock(vb->vb2_queue->lock);
1449         WARN_ON(!vb->req_obj.req);
1450 }
1451
1452 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1453                   struct media_request *req);
1454
1455 static void vb2_req_queue(struct media_request_object *obj)
1456 {
1457         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1458         int err;
1459
1460         mutex_lock(vb->vb2_queue->lock);
1461         /*
1462          * There is no method to propagate an error from vb2_core_qbuf(),
1463          * so if this returns a non-0 value, then WARN.
1464          *
1465          * The only exception is -EIO which is returned if q->error is
1466          * set. We just ignore that, and expect this will be caught the
1467          * next time vb2_req_prepare() is called.
1468          */
1469         err = vb2_core_qbuf(vb->vb2_queue, vb->index, NULL, NULL);
1470         WARN_ON_ONCE(err && err != -EIO);
1471         mutex_unlock(vb->vb2_queue->lock);
1472 }
1473
1474 static void vb2_req_unbind(struct media_request_object *obj)
1475 {
1476         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1477
1478         if (vb->state == VB2_BUF_STATE_IN_REQUEST)
1479                 call_void_bufop(vb->vb2_queue, init_buffer, vb);
1480 }
1481
1482 static void vb2_req_release(struct media_request_object *obj)
1483 {
1484         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1485
1486         if (vb->state == VB2_BUF_STATE_IN_REQUEST) {
1487                 vb->state = VB2_BUF_STATE_DEQUEUED;
1488                 if (vb->request)
1489                         media_request_put(vb->request);
1490                 vb->request = NULL;
1491         }
1492 }
1493
1494 static const struct media_request_object_ops vb2_core_req_ops = {
1495         .prepare = vb2_req_prepare,
1496         .unprepare = vb2_req_unprepare,
1497         .queue = vb2_req_queue,
1498         .unbind = vb2_req_unbind,
1499         .release = vb2_req_release,
1500 };
1501
1502 bool vb2_request_object_is_buffer(struct media_request_object *obj)
1503 {
1504         return obj->ops == &vb2_core_req_ops;
1505 }
1506 EXPORT_SYMBOL_GPL(vb2_request_object_is_buffer);
1507
1508 unsigned int vb2_request_buffer_cnt(struct media_request *req)
1509 {
1510         struct media_request_object *obj;
1511         unsigned long flags;
1512         unsigned int buffer_cnt = 0;
1513
1514         spin_lock_irqsave(&req->lock, flags);
1515         list_for_each_entry(obj, &req->objects, list)
1516                 if (vb2_request_object_is_buffer(obj))
1517                         buffer_cnt++;
1518         spin_unlock_irqrestore(&req->lock, flags);
1519
1520         return buffer_cnt;
1521 }
1522 EXPORT_SYMBOL_GPL(vb2_request_buffer_cnt);
1523
1524 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1525 {
1526         struct vb2_buffer *vb;
1527         int ret;
1528
1529         vb = q->bufs[index];
1530         if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1531                 dprintk(q, 1, "invalid buffer state %s\n",
1532                         vb2_state_name(vb->state));
1533                 return -EINVAL;
1534         }
1535         if (vb->prepared) {
1536                 dprintk(q, 1, "buffer already prepared\n");
1537                 return -EINVAL;
1538         }
1539
1540         ret = __buf_prepare(vb);
1541         if (ret)
1542                 return ret;
1543
1544         /* Fill buffer information for the userspace */
1545         call_void_bufop(q, fill_user_buffer, vb, pb);
1546
1547         dprintk(q, 2, "prepare of buffer %d succeeded\n", vb->index);
1548
1549         return 0;
1550 }
1551 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1552
1553 /*
1554  * vb2_start_streaming() - Attempt to start streaming.
1555  * @q:          videobuf2 queue
1556  *
1557  * Attempt to start streaming. When this function is called there must be
1558  * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1559  * number of buffers required for the DMA engine to function). If the
1560  * @start_streaming op fails it is supposed to return all the driver-owned
1561  * buffers back to vb2 in state QUEUED. Check if that happened and if
1562  * not warn and reclaim them forcefully.
1563  */
1564 static int vb2_start_streaming(struct vb2_queue *q)
1565 {
1566         struct vb2_buffer *vb;
1567         int ret;
1568
1569         /*
1570          * If any buffers were queued before streamon,
1571          * we can now pass them to driver for processing.
1572          */
1573         list_for_each_entry(vb, &q->queued_list, queued_entry)
1574                 __enqueue_in_driver(vb);
1575
1576         /* Tell the driver to start streaming */
1577         q->start_streaming_called = 1;
1578         ret = call_qop(q, start_streaming, q,
1579                        atomic_read(&q->owned_by_drv_count));
1580         if (!ret)
1581                 return 0;
1582
1583         q->start_streaming_called = 0;
1584
1585         dprintk(q, 1, "driver refused to start streaming\n");
1586         /*
1587          * If you see this warning, then the driver isn't cleaning up properly
1588          * after a failed start_streaming(). See the start_streaming()
1589          * documentation in videobuf2-core.h for more information how buffers
1590          * should be returned to vb2 in start_streaming().
1591          */
1592         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1593                 unsigned i;
1594
1595                 /*
1596                  * Forcefully reclaim buffers if the driver did not
1597                  * correctly return them to vb2.
1598                  */
1599                 for (i = 0; i < q->num_buffers; ++i) {
1600                         vb = q->bufs[i];
1601                         if (vb->state == VB2_BUF_STATE_ACTIVE)
1602                                 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1603                 }
1604                 /* Must be zero now */
1605                 WARN_ON(atomic_read(&q->owned_by_drv_count));
1606         }
1607         /*
1608          * If done_list is not empty, then start_streaming() didn't call
1609          * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1610          * STATE_DONE.
1611          */
1612         WARN_ON(!list_empty(&q->done_list));
1613         return ret;
1614 }
1615
1616 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1617                   struct media_request *req)
1618 {
1619         struct vb2_buffer *vb;
1620         enum vb2_buffer_state orig_state;
1621         int ret;
1622
1623         if (q->error) {
1624                 dprintk(q, 1, "fatal error occurred on queue\n");
1625                 return -EIO;
1626         }
1627
1628         vb = q->bufs[index];
1629
1630         if (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1631             q->requires_requests) {
1632                 dprintk(q, 1, "qbuf requires a request\n");
1633                 return -EBADR;
1634         }
1635
1636         if ((req && q->uses_qbuf) ||
1637             (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1638              q->uses_requests)) {
1639                 dprintk(q, 1, "queue in wrong mode (qbuf vs requests)\n");
1640                 return -EBUSY;
1641         }
1642
1643         if (req) {
1644                 int ret;
1645
1646                 q->uses_requests = 1;
1647                 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1648                         dprintk(q, 1, "buffer %d not in dequeued state\n",
1649                                 vb->index);
1650                         return -EINVAL;
1651                 }
1652
1653                 if (q->is_output && !vb->prepared) {
1654                         ret = call_vb_qop(vb, buf_out_validate, vb);
1655                         if (ret) {
1656                                 dprintk(q, 1, "buffer validation failed\n");
1657                                 return ret;
1658                         }
1659                 }
1660
1661                 media_request_object_init(&vb->req_obj);
1662
1663                 /* Make sure the request is in a safe state for updating. */
1664                 ret = media_request_lock_for_update(req);
1665                 if (ret)
1666                         return ret;
1667                 ret = media_request_object_bind(req, &vb2_core_req_ops,
1668                                                 q, true, &vb->req_obj);
1669                 media_request_unlock_for_update(req);
1670                 if (ret)
1671                         return ret;
1672
1673                 vb->state = VB2_BUF_STATE_IN_REQUEST;
1674
1675                 /*
1676                  * Increment the refcount and store the request.
1677                  * The request refcount is decremented again when the
1678                  * buffer is dequeued. This is to prevent vb2_buffer_done()
1679                  * from freeing the request from interrupt context, which can
1680                  * happen if the application closed the request fd after
1681                  * queueing the request.
1682                  */
1683                 media_request_get(req);
1684                 vb->request = req;
1685
1686                 /* Fill buffer information for the userspace */
1687                 if (pb) {
1688                         call_void_bufop(q, copy_timestamp, vb, pb);
1689                         call_void_bufop(q, fill_user_buffer, vb, pb);
1690                 }
1691
1692                 dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
1693                 return 0;
1694         }
1695
1696         if (vb->state != VB2_BUF_STATE_IN_REQUEST)
1697                 q->uses_qbuf = 1;
1698
1699         switch (vb->state) {
1700         case VB2_BUF_STATE_DEQUEUED:
1701         case VB2_BUF_STATE_IN_REQUEST:
1702                 if (!vb->prepared) {
1703                         ret = __buf_prepare(vb);
1704                         if (ret)
1705                                 return ret;
1706                 }
1707                 break;
1708         case VB2_BUF_STATE_PREPARING:
1709                 dprintk(q, 1, "buffer still being prepared\n");
1710                 return -EINVAL;
1711         default:
1712                 dprintk(q, 1, "invalid buffer state %s\n",
1713                         vb2_state_name(vb->state));
1714                 return -EINVAL;
1715         }
1716
1717         /*
1718          * Add to the queued buffers list, a buffer will stay on it until
1719          * dequeued in dqbuf.
1720          */
1721         orig_state = vb->state;
1722         list_add_tail(&vb->queued_entry, &q->queued_list);
1723         q->queued_count++;
1724         q->waiting_for_buffers = false;
1725         vb->state = VB2_BUF_STATE_QUEUED;
1726
1727         if (pb)
1728                 call_void_bufop(q, copy_timestamp, vb, pb);
1729
1730         trace_vb2_qbuf(q, vb);
1731
1732         /*
1733          * If already streaming, give the buffer to driver for processing.
1734          * If not, the buffer will be given to driver on next streamon.
1735          */
1736         if (q->start_streaming_called)
1737                 __enqueue_in_driver(vb);
1738
1739         /* Fill buffer information for the userspace */
1740         if (pb)
1741                 call_void_bufop(q, fill_user_buffer, vb, pb);
1742
1743         /*
1744          * If streamon has been called, and we haven't yet called
1745          * start_streaming() since not enough buffers were queued, and
1746          * we now have reached the minimum number of queued buffers,
1747          * then we can finally call start_streaming().
1748          */
1749         if (q->streaming && !q->start_streaming_called &&
1750             q->queued_count >= q->min_buffers_needed) {
1751                 ret = vb2_start_streaming(q);
1752                 if (ret) {
1753                         /*
1754                          * Since vb2_core_qbuf will return with an error,
1755                          * we should return it to state DEQUEUED since
1756                          * the error indicates that the buffer wasn't queued.
1757                          */
1758                         list_del(&vb->queued_entry);
1759                         q->queued_count--;
1760                         vb->state = orig_state;
1761                         return ret;
1762                 }
1763         }
1764
1765         dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
1766         return 0;
1767 }
1768 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1769
1770 /*
1771  * __vb2_wait_for_done_vb() - wait for a buffer to become available
1772  * for dequeuing
1773  *
1774  * Will sleep if required for nonblocking == false.
1775  */
1776 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1777 {
1778         /*
1779          * All operations on vb_done_list are performed under done_lock
1780          * spinlock protection. However, buffers may be removed from
1781          * it and returned to userspace only while holding both driver's
1782          * lock and the done_lock spinlock. Thus we can be sure that as
1783          * long as we hold the driver's lock, the list will remain not
1784          * empty if list_empty() check succeeds.
1785          */
1786
1787         for (;;) {
1788                 int ret;
1789
1790                 if (q->waiting_in_dqbuf) {
1791                         dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
1792                         return -EBUSY;
1793                 }
1794
1795                 if (!q->streaming) {
1796                         dprintk(q, 1, "streaming off, will not wait for buffers\n");
1797                         return -EINVAL;
1798                 }
1799
1800                 if (q->error) {
1801                         dprintk(q, 1, "Queue in error state, will not wait for buffers\n");
1802                         return -EIO;
1803                 }
1804
1805                 if (q->last_buffer_dequeued) {
1806                         dprintk(q, 3, "last buffer dequeued already, will not wait for buffers\n");
1807                         return -EPIPE;
1808                 }
1809
1810                 if (!list_empty(&q->done_list)) {
1811                         /*
1812                          * Found a buffer that we were waiting for.
1813                          */
1814                         break;
1815                 }
1816
1817                 if (nonblocking) {
1818                         dprintk(q, 3, "nonblocking and no buffers to dequeue, will not wait\n");
1819                         return -EAGAIN;
1820                 }
1821
1822                 q->waiting_in_dqbuf = 1;
1823                 /*
1824                  * We are streaming and blocking, wait for another buffer to
1825                  * become ready or for streamoff. Driver's lock is released to
1826                  * allow streamoff or qbuf to be called while waiting.
1827                  */
1828                 call_void_qop(q, wait_prepare, q);
1829
1830                 /*
1831                  * All locks have been released, it is safe to sleep now.
1832                  */
1833                 dprintk(q, 3, "will sleep waiting for buffers\n");
1834                 ret = wait_event_interruptible(q->done_wq,
1835                                 !list_empty(&q->done_list) || !q->streaming ||
1836                                 q->error);
1837
1838                 /*
1839                  * We need to reevaluate both conditions again after reacquiring
1840                  * the locks or return an error if one occurred.
1841                  */
1842                 call_void_qop(q, wait_finish, q);
1843                 q->waiting_in_dqbuf = 0;
1844                 if (ret) {
1845                         dprintk(q, 1, "sleep was interrupted\n");
1846                         return ret;
1847                 }
1848         }
1849         return 0;
1850 }
1851
1852 /*
1853  * __vb2_get_done_vb() - get a buffer ready for dequeuing
1854  *
1855  * Will sleep if required for nonblocking == false.
1856  */
1857 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1858                              void *pb, int nonblocking)
1859 {
1860         unsigned long flags;
1861         int ret = 0;
1862
1863         /*
1864          * Wait for at least one buffer to become available on the done_list.
1865          */
1866         ret = __vb2_wait_for_done_vb(q, nonblocking);
1867         if (ret)
1868                 return ret;
1869
1870         /*
1871          * Driver's lock has been held since we last verified that done_list
1872          * is not empty, so no need for another list_empty(done_list) check.
1873          */
1874         spin_lock_irqsave(&q->done_lock, flags);
1875         *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1876         /*
1877          * Only remove the buffer from done_list if all planes can be
1878          * handled. Some cases such as V4L2 file I/O and DVB have pb
1879          * == NULL; skip the check then as there's nothing to verify.
1880          */
1881         if (pb)
1882                 ret = call_bufop(q, verify_planes_array, *vb, pb);
1883         if (!ret)
1884                 list_del(&(*vb)->done_entry);
1885         spin_unlock_irqrestore(&q->done_lock, flags);
1886
1887         return ret;
1888 }
1889
1890 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1891 {
1892         if (!q->streaming) {
1893                 dprintk(q, 1, "streaming off, will not wait for buffers\n");
1894                 return -EINVAL;
1895         }
1896
1897         if (q->start_streaming_called)
1898                 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1899         return 0;
1900 }
1901 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1902
1903 /*
1904  * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1905  */
1906 static void __vb2_dqbuf(struct vb2_buffer *vb)
1907 {
1908         struct vb2_queue *q = vb->vb2_queue;
1909
1910         /* nothing to do if the buffer is already dequeued */
1911         if (vb->state == VB2_BUF_STATE_DEQUEUED)
1912                 return;
1913
1914         vb->state = VB2_BUF_STATE_DEQUEUED;
1915
1916         call_void_bufop(q, init_buffer, vb);
1917 }
1918
1919 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1920                    bool nonblocking)
1921 {
1922         struct vb2_buffer *vb = NULL;
1923         int ret;
1924
1925         ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1926         if (ret < 0)
1927                 return ret;
1928
1929         switch (vb->state) {
1930         case VB2_BUF_STATE_DONE:
1931                 dprintk(q, 3, "returning done buffer\n");
1932                 break;
1933         case VB2_BUF_STATE_ERROR:
1934                 dprintk(q, 3, "returning done buffer with errors\n");
1935                 break;
1936         default:
1937                 dprintk(q, 1, "invalid buffer state %s\n",
1938                         vb2_state_name(vb->state));
1939                 return -EINVAL;
1940         }
1941
1942         call_void_vb_qop(vb, buf_finish, vb);
1943         vb->prepared = 0;
1944
1945         if (pindex)
1946                 *pindex = vb->index;
1947
1948         /* Fill buffer information for the userspace */
1949         if (pb)
1950                 call_void_bufop(q, fill_user_buffer, vb, pb);
1951
1952         /* Remove from videobuf queue */
1953         list_del(&vb->queued_entry);
1954         q->queued_count--;
1955
1956         trace_vb2_dqbuf(q, vb);
1957
1958         /* go back to dequeued state */
1959         __vb2_dqbuf(vb);
1960
1961         if (WARN_ON(vb->req_obj.req)) {
1962                 media_request_object_unbind(&vb->req_obj);
1963                 media_request_object_put(&vb->req_obj);
1964         }
1965         if (vb->request)
1966                 media_request_put(vb->request);
1967         vb->request = NULL;
1968
1969         dprintk(q, 2, "dqbuf of buffer %d, state: %s\n",
1970                 vb->index, vb2_state_name(vb->state));
1971
1972         return 0;
1973
1974 }
1975 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
1976
1977 /*
1978  * __vb2_queue_cancel() - cancel and stop (pause) streaming
1979  *
1980  * Removes all queued buffers from driver's queue and all buffers queued by
1981  * userspace from videobuf's queue. Returns to state after reqbufs.
1982  */
1983 static void __vb2_queue_cancel(struct vb2_queue *q)
1984 {
1985         unsigned int i;
1986
1987         /*
1988          * Tell driver to stop all transactions and release all queued
1989          * buffers.
1990          */
1991         if (q->start_streaming_called)
1992                 call_void_qop(q, stop_streaming, q);
1993
1994         /*
1995          * If you see this warning, then the driver isn't cleaning up properly
1996          * in stop_streaming(). See the stop_streaming() documentation in
1997          * videobuf2-core.h for more information how buffers should be returned
1998          * to vb2 in stop_streaming().
1999          */
2000         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
2001                 for (i = 0; i < q->num_buffers; ++i)
2002                         if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE) {
2003                                 pr_warn("driver bug: stop_streaming operation is leaving buf %p in active state\n",
2004                                         q->bufs[i]);
2005                                 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
2006                         }
2007                 /* Must be zero now */
2008                 WARN_ON(atomic_read(&q->owned_by_drv_count));
2009         }
2010
2011         q->streaming = 0;
2012         q->start_streaming_called = 0;
2013         q->queued_count = 0;
2014         q->error = 0;
2015         q->uses_requests = 0;
2016         q->uses_qbuf = 0;
2017
2018         /*
2019          * Remove all buffers from videobuf's list...
2020          */
2021         INIT_LIST_HEAD(&q->queued_list);
2022         /*
2023          * ...and done list; userspace will not receive any buffers it
2024          * has not already dequeued before initiating cancel.
2025          */
2026         INIT_LIST_HEAD(&q->done_list);
2027         atomic_set(&q->owned_by_drv_count, 0);
2028         wake_up_all(&q->done_wq);
2029
2030         /*
2031          * Reinitialize all buffers for next use.
2032          * Make sure to call buf_finish for any queued buffers. Normally
2033          * that's done in dqbuf, but that's not going to happen when we
2034          * cancel the whole queue. Note: this code belongs here, not in
2035          * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
2036          * call to __fill_user_buffer() after buf_finish(). That order can't
2037          * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2038          */
2039         for (i = 0; i < q->num_buffers; ++i) {
2040                 struct vb2_buffer *vb = q->bufs[i];
2041                 struct media_request *req = vb->req_obj.req;
2042
2043                 /*
2044                  * If a request is associated with this buffer, then
2045                  * call buf_request_cancel() to give the driver to complete()
2046                  * related request objects. Otherwise those objects would
2047                  * never complete.
2048                  */
2049                 if (req) {
2050                         enum media_request_state state;
2051                         unsigned long flags;
2052
2053                         spin_lock_irqsave(&req->lock, flags);
2054                         state = req->state;
2055                         spin_unlock_irqrestore(&req->lock, flags);
2056
2057                         if (state == MEDIA_REQUEST_STATE_QUEUED)
2058                                 call_void_vb_qop(vb, buf_request_complete, vb);
2059                 }
2060
2061                 __vb2_buf_mem_finish(vb);
2062
2063                 if (vb->prepared) {
2064                         call_void_vb_qop(vb, buf_finish, vb);
2065                         vb->prepared = 0;
2066                 }
2067                 __vb2_dqbuf(vb);
2068
2069                 if (vb->req_obj.req) {
2070                         media_request_object_unbind(&vb->req_obj);
2071                         media_request_object_put(&vb->req_obj);
2072                 }
2073                 if (vb->request)
2074                         media_request_put(vb->request);
2075                 vb->request = NULL;
2076                 vb->copied_timestamp = 0;
2077         }
2078 }
2079
2080 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
2081 {
2082         int ret;
2083
2084         if (type != q->type) {
2085                 dprintk(q, 1, "invalid stream type\n");
2086                 return -EINVAL;
2087         }
2088
2089         if (q->streaming) {
2090                 dprintk(q, 3, "already streaming\n");
2091                 return 0;
2092         }
2093
2094         if (!q->num_buffers) {
2095                 dprintk(q, 1, "no buffers have been allocated\n");
2096                 return -EINVAL;
2097         }
2098
2099         if (q->num_buffers < q->min_buffers_needed) {
2100                 dprintk(q, 1, "need at least %u allocated buffers\n",
2101                                 q->min_buffers_needed);
2102                 return -EINVAL;
2103         }
2104
2105         /*
2106          * Tell driver to start streaming provided sufficient buffers
2107          * are available.
2108          */
2109         if (q->queued_count >= q->min_buffers_needed) {
2110                 ret = v4l_vb2q_enable_media_source(q);
2111                 if (ret)
2112                         return ret;
2113                 ret = vb2_start_streaming(q);
2114                 if (ret)
2115                         return ret;
2116         }
2117
2118         q->streaming = 1;
2119
2120         dprintk(q, 3, "successful\n");
2121         return 0;
2122 }
2123 EXPORT_SYMBOL_GPL(vb2_core_streamon);
2124
2125 void vb2_queue_error(struct vb2_queue *q)
2126 {
2127         q->error = 1;
2128
2129         wake_up_all(&q->done_wq);
2130 }
2131 EXPORT_SYMBOL_GPL(vb2_queue_error);
2132
2133 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
2134 {
2135         if (type != q->type) {
2136                 dprintk(q, 1, "invalid stream type\n");
2137                 return -EINVAL;
2138         }
2139
2140         /*
2141          * Cancel will pause streaming and remove all buffers from the driver
2142          * and videobuf, effectively returning control over them to userspace.
2143          *
2144          * Note that we do this even if q->streaming == 0: if you prepare or
2145          * queue buffers, and then call streamoff without ever having called
2146          * streamon, you would still expect those buffers to be returned to
2147          * their normal dequeued state.
2148          */
2149         __vb2_queue_cancel(q);
2150         q->waiting_for_buffers = !q->is_output;
2151         q->last_buffer_dequeued = false;
2152
2153         dprintk(q, 3, "successful\n");
2154         return 0;
2155 }
2156 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
2157
2158 /*
2159  * __find_plane_by_offset() - find plane associated with the given offset off
2160  */
2161 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2162                         unsigned int *_buffer, unsigned int *_plane)
2163 {
2164         struct vb2_buffer *vb;
2165         unsigned int buffer, plane;
2166
2167         /*
2168          * Go over all buffers and their planes, comparing the given offset
2169          * with an offset assigned to each plane. If a match is found,
2170          * return its buffer and plane numbers.
2171          */
2172         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2173                 vb = q->bufs[buffer];
2174
2175                 for (plane = 0; plane < vb->num_planes; ++plane) {
2176                         if (vb->planes[plane].m.offset == off) {
2177                                 *_buffer = buffer;
2178                                 *_plane = plane;
2179                                 return 0;
2180                         }
2181                 }
2182         }
2183
2184         return -EINVAL;
2185 }
2186
2187 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
2188                 unsigned int index, unsigned int plane, unsigned int flags)
2189 {
2190         struct vb2_buffer *vb = NULL;
2191         struct vb2_plane *vb_plane;
2192         int ret;
2193         struct dma_buf *dbuf;
2194
2195         if (q->memory != VB2_MEMORY_MMAP) {
2196                 dprintk(q, 1, "queue is not currently set up for mmap\n");
2197                 return -EINVAL;
2198         }
2199
2200         if (!q->mem_ops->get_dmabuf) {
2201                 dprintk(q, 1, "queue does not support DMA buffer exporting\n");
2202                 return -EINVAL;
2203         }
2204
2205         if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
2206                 dprintk(q, 1, "queue does support only O_CLOEXEC and access mode flags\n");
2207                 return -EINVAL;
2208         }
2209
2210         if (type != q->type) {
2211                 dprintk(q, 1, "invalid buffer type\n");
2212                 return -EINVAL;
2213         }
2214
2215         if (index >= q->num_buffers) {
2216                 dprintk(q, 1, "buffer index out of range\n");
2217                 return -EINVAL;
2218         }
2219
2220         vb = q->bufs[index];
2221
2222         if (plane >= vb->num_planes) {
2223                 dprintk(q, 1, "buffer plane out of range\n");
2224                 return -EINVAL;
2225         }
2226
2227         if (vb2_fileio_is_active(q)) {
2228                 dprintk(q, 1, "expbuf: file io in progress\n");
2229                 return -EBUSY;
2230         }
2231
2232         vb_plane = &vb->planes[plane];
2233
2234         dbuf = call_ptr_memop(get_dmabuf,
2235                               vb,
2236                               vb_plane->mem_priv,
2237                               flags & O_ACCMODE);
2238         if (IS_ERR_OR_NULL(dbuf)) {
2239                 dprintk(q, 1, "failed to export buffer %d, plane %d\n",
2240                         index, plane);
2241                 return -EINVAL;
2242         }
2243
2244         ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
2245         if (ret < 0) {
2246                 dprintk(q, 3, "buffer %d, plane %d failed to export (%d)\n",
2247                         index, plane, ret);
2248                 dma_buf_put(dbuf);
2249                 return ret;
2250         }
2251
2252         dprintk(q, 3, "buffer %d, plane %d exported as %d descriptor\n",
2253                 index, plane, ret);
2254         *fd = ret;
2255
2256         return 0;
2257 }
2258 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
2259
2260 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2261 {
2262         unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2263         struct vb2_buffer *vb;
2264         unsigned int buffer = 0, plane = 0;
2265         int ret;
2266         unsigned long length;
2267
2268         if (q->memory != VB2_MEMORY_MMAP) {
2269                 dprintk(q, 1, "queue is not currently set up for mmap\n");
2270                 return -EINVAL;
2271         }
2272
2273         /*
2274          * Check memory area access mode.
2275          */
2276         if (!(vma->vm_flags & VM_SHARED)) {
2277                 dprintk(q, 1, "invalid vma flags, VM_SHARED needed\n");
2278                 return -EINVAL;
2279         }
2280         if (q->is_output) {
2281                 if (!(vma->vm_flags & VM_WRITE)) {
2282                         dprintk(q, 1, "invalid vma flags, VM_WRITE needed\n");
2283                         return -EINVAL;
2284                 }
2285         } else {
2286                 if (!(vma->vm_flags & VM_READ)) {
2287                         dprintk(q, 1, "invalid vma flags, VM_READ needed\n");
2288                         return -EINVAL;
2289                 }
2290         }
2291
2292         mutex_lock(&q->mmap_lock);
2293
2294         if (vb2_fileio_is_active(q)) {
2295                 dprintk(q, 1, "mmap: file io in progress\n");
2296                 ret = -EBUSY;
2297                 goto unlock;
2298         }
2299
2300         /*
2301          * Find the plane corresponding to the offset passed by userspace.
2302          */
2303         ret = __find_plane_by_offset(q, off, &buffer, &plane);
2304         if (ret)
2305                 goto unlock;
2306
2307         vb = q->bufs[buffer];
2308
2309         /*
2310          * MMAP requires page_aligned buffers.
2311          * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2312          * so, we need to do the same here.
2313          */
2314         length = PAGE_ALIGN(vb->planes[plane].length);
2315         if (length < (vma->vm_end - vma->vm_start)) {
2316                 dprintk(q, 1,
2317                         "MMAP invalid, as it would overflow buffer length\n");
2318                 ret = -EINVAL;
2319                 goto unlock;
2320         }
2321
2322         /*
2323          * vm_pgoff is treated in V4L2 API as a 'cookie' to select a buffer,
2324          * not as a in-buffer offset. We always want to mmap a whole buffer
2325          * from its beginning.
2326          */
2327         vma->vm_pgoff = 0;
2328
2329         ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2330
2331 unlock:
2332         mutex_unlock(&q->mmap_lock);
2333         if (ret)
2334                 return ret;
2335
2336         dprintk(q, 3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2337         return 0;
2338 }
2339 EXPORT_SYMBOL_GPL(vb2_mmap);
2340
2341 #ifndef CONFIG_MMU
2342 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2343                                     unsigned long addr,
2344                                     unsigned long len,
2345                                     unsigned long pgoff,
2346                                     unsigned long flags)
2347 {
2348         unsigned long off = pgoff << PAGE_SHIFT;
2349         struct vb2_buffer *vb;
2350         unsigned int buffer, plane;
2351         void *vaddr;
2352         int ret;
2353
2354         if (q->memory != VB2_MEMORY_MMAP) {
2355                 dprintk(q, 1, "queue is not currently set up for mmap\n");
2356                 return -EINVAL;
2357         }
2358
2359         /*
2360          * Find the plane corresponding to the offset passed by userspace.
2361          */
2362         ret = __find_plane_by_offset(q, off, &buffer, &plane);
2363         if (ret)
2364                 return ret;
2365
2366         vb = q->bufs[buffer];
2367
2368         vaddr = vb2_plane_vaddr(vb, plane);
2369         return vaddr ? (unsigned long)vaddr : -EINVAL;
2370 }
2371 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2372 #endif
2373
2374 int vb2_core_queue_init(struct vb2_queue *q)
2375 {
2376         /*
2377          * Sanity check
2378          */
2379         if (WARN_ON(!q)                   ||
2380             WARN_ON(!q->ops)              ||
2381             WARN_ON(!q->mem_ops)          ||
2382             WARN_ON(!q->type)             ||
2383             WARN_ON(!q->io_modes)         ||
2384             WARN_ON(!q->ops->queue_setup) ||
2385             WARN_ON(!q->ops->buf_queue))
2386                 return -EINVAL;
2387
2388         if (WARN_ON(q->requires_requests && !q->supports_requests))
2389                 return -EINVAL;
2390
2391         /*
2392          * This combination is not allowed since a non-zero value of
2393          * q->min_buffers_needed can cause vb2_core_qbuf() to fail if
2394          * it has to call start_streaming(), and the Request API expects
2395          * that queueing a request (and thus queueing a buffer contained
2396          * in that request) will always succeed. There is no method of
2397          * propagating an error back to userspace.
2398          */
2399         if (WARN_ON(q->supports_requests && q->min_buffers_needed))
2400                 return -EINVAL;
2401
2402         INIT_LIST_HEAD(&q->queued_list);
2403         INIT_LIST_HEAD(&q->done_list);
2404         spin_lock_init(&q->done_lock);
2405         mutex_init(&q->mmap_lock);
2406         init_waitqueue_head(&q->done_wq);
2407
2408         q->memory = VB2_MEMORY_UNKNOWN;
2409
2410         if (q->buf_struct_size == 0)
2411                 q->buf_struct_size = sizeof(struct vb2_buffer);
2412
2413         if (q->bidirectional)
2414                 q->dma_dir = DMA_BIDIRECTIONAL;
2415         else
2416                 q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
2417
2418         if (q->name[0] == '\0')
2419                 snprintf(q->name, sizeof(q->name), "%s-%p",
2420                          q->is_output ? "out" : "cap", q);
2421
2422         return 0;
2423 }
2424 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2425
2426 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2427 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2428 void vb2_core_queue_release(struct vb2_queue *q)
2429 {
2430         __vb2_cleanup_fileio(q);
2431         __vb2_queue_cancel(q);
2432         mutex_lock(&q->mmap_lock);
2433         __vb2_queue_free(q, q->num_buffers);
2434         mutex_unlock(&q->mmap_lock);
2435 }
2436 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2437
2438 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
2439                 poll_table *wait)
2440 {
2441         __poll_t req_events = poll_requested_events(wait);
2442         struct vb2_buffer *vb = NULL;
2443         unsigned long flags;
2444
2445         /*
2446          * poll_wait() MUST be called on the first invocation on all the
2447          * potential queues of interest, even if we are not interested in their
2448          * events during this first call. Failure to do so will result in
2449          * queue's events to be ignored because the poll_table won't be capable
2450          * of adding new wait queues thereafter.
2451          */
2452         poll_wait(file, &q->done_wq, wait);
2453
2454         if (!q->is_output && !(req_events & (EPOLLIN | EPOLLRDNORM)))
2455                 return 0;
2456         if (q->is_output && !(req_events & (EPOLLOUT | EPOLLWRNORM)))
2457                 return 0;
2458
2459         /*
2460          * Start file I/O emulator only if streaming API has not been used yet.
2461          */
2462         if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2463                 if (!q->is_output && (q->io_modes & VB2_READ) &&
2464                                 (req_events & (EPOLLIN | EPOLLRDNORM))) {
2465                         if (__vb2_init_fileio(q, 1))
2466                                 return EPOLLERR;
2467                 }
2468                 if (q->is_output && (q->io_modes & VB2_WRITE) &&
2469                                 (req_events & (EPOLLOUT | EPOLLWRNORM))) {
2470                         if (__vb2_init_fileio(q, 0))
2471                                 return EPOLLERR;
2472                         /*
2473                          * Write to OUTPUT queue can be done immediately.
2474                          */
2475                         return EPOLLOUT | EPOLLWRNORM;
2476                 }
2477         }
2478
2479         /*
2480          * There is nothing to wait for if the queue isn't streaming, or if the
2481          * error flag is set.
2482          */
2483         if (!vb2_is_streaming(q) || q->error)
2484                 return EPOLLERR;
2485
2486         /*
2487          * If this quirk is set and QBUF hasn't been called yet then
2488          * return EPOLLERR as well. This only affects capture queues, output
2489          * queues will always initialize waiting_for_buffers to false.
2490          * This quirk is set by V4L2 for backwards compatibility reasons.
2491          */
2492         if (q->quirk_poll_must_check_waiting_for_buffers &&
2493             q->waiting_for_buffers && (req_events & (EPOLLIN | EPOLLRDNORM)))
2494                 return EPOLLERR;
2495
2496         /*
2497          * For output streams you can call write() as long as there are fewer
2498          * buffers queued than there are buffers available.
2499          */
2500         if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2501                 return EPOLLOUT | EPOLLWRNORM;
2502
2503         if (list_empty(&q->done_list)) {
2504                 /*
2505                  * If the last buffer was dequeued from a capture queue,
2506                  * return immediately. DQBUF will return -EPIPE.
2507                  */
2508                 if (q->last_buffer_dequeued)
2509                         return EPOLLIN | EPOLLRDNORM;
2510         }
2511
2512         /*
2513          * Take first buffer available for dequeuing.
2514          */
2515         spin_lock_irqsave(&q->done_lock, flags);
2516         if (!list_empty(&q->done_list))
2517                 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2518                                         done_entry);
2519         spin_unlock_irqrestore(&q->done_lock, flags);
2520
2521         if (vb && (vb->state == VB2_BUF_STATE_DONE
2522                         || vb->state == VB2_BUF_STATE_ERROR)) {
2523                 return (q->is_output) ?
2524                                 EPOLLOUT | EPOLLWRNORM :
2525                                 EPOLLIN | EPOLLRDNORM;
2526         }
2527         return 0;
2528 }
2529 EXPORT_SYMBOL_GPL(vb2_core_poll);
2530
2531 /*
2532  * struct vb2_fileio_buf - buffer context used by file io emulator
2533  *
2534  * vb2 provides a compatibility layer and emulator of file io (read and
2535  * write) calls on top of streaming API. This structure is used for
2536  * tracking context related to the buffers.
2537  */
2538 struct vb2_fileio_buf {
2539         void *vaddr;
2540         unsigned int size;
2541         unsigned int pos;
2542         unsigned int queued:1;
2543 };
2544
2545 /*
2546  * struct vb2_fileio_data - queue context used by file io emulator
2547  *
2548  * @cur_index:  the index of the buffer currently being read from or
2549  *              written to. If equal to q->num_buffers then a new buffer
2550  *              must be dequeued.
2551  * @initial_index: in the read() case all buffers are queued up immediately
2552  *              in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2553  *              buffers. However, in the write() case no buffers are initially
2554  *              queued, instead whenever a buffer is full it is queued up by
2555  *              __vb2_perform_fileio(). Only once all available buffers have
2556  *              been queued up will __vb2_perform_fileio() start to dequeue
2557  *              buffers. This means that initially __vb2_perform_fileio()
2558  *              needs to know what buffer index to use when it is queuing up
2559  *              the buffers for the first time. That initial index is stored
2560  *              in this field. Once it is equal to q->num_buffers all
2561  *              available buffers have been queued and __vb2_perform_fileio()
2562  *              should start the normal dequeue/queue cycle.
2563  *
2564  * vb2 provides a compatibility layer and emulator of file io (read and
2565  * write) calls on top of streaming API. For proper operation it required
2566  * this structure to save the driver state between each call of the read
2567  * or write function.
2568  */
2569 struct vb2_fileio_data {
2570         unsigned int count;
2571         unsigned int type;
2572         unsigned int memory;
2573         struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2574         unsigned int cur_index;
2575         unsigned int initial_index;
2576         unsigned int q_count;
2577         unsigned int dq_count;
2578         unsigned read_once:1;
2579         unsigned write_immediately:1;
2580 };
2581
2582 /*
2583  * __vb2_init_fileio() - initialize file io emulator
2584  * @q:          videobuf2 queue
2585  * @read:       mode selector (1 means read, 0 means write)
2586  */
2587 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2588 {
2589         struct vb2_fileio_data *fileio;
2590         int i, ret;
2591         unsigned int count = 0;
2592
2593         /*
2594          * Sanity check
2595          */
2596         if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2597                     (!read && !(q->io_modes & VB2_WRITE))))
2598                 return -EINVAL;
2599
2600         /*
2601          * Check if device supports mapping buffers to kernel virtual space.
2602          */
2603         if (!q->mem_ops->vaddr)
2604                 return -EBUSY;
2605
2606         /*
2607          * Check if streaming api has not been already activated.
2608          */
2609         if (q->streaming || q->num_buffers > 0)
2610                 return -EBUSY;
2611
2612         /*
2613          * Start with count 1, driver can increase it in queue_setup()
2614          */
2615         count = 1;
2616
2617         dprintk(q, 3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2618                 (read) ? "read" : "write", count, q->fileio_read_once,
2619                 q->fileio_write_immediately);
2620
2621         fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2622         if (fileio == NULL)
2623                 return -ENOMEM;
2624
2625         fileio->read_once = q->fileio_read_once;
2626         fileio->write_immediately = q->fileio_write_immediately;
2627
2628         /*
2629          * Request buffers and use MMAP type to force driver
2630          * to allocate buffers by itself.
2631          */
2632         fileio->count = count;
2633         fileio->memory = VB2_MEMORY_MMAP;
2634         fileio->type = q->type;
2635         q->fileio = fileio;
2636         ret = vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
2637         if (ret)
2638                 goto err_kfree;
2639
2640         /*
2641          * Check if plane_count is correct
2642          * (multiplane buffers are not supported).
2643          */
2644         if (q->bufs[0]->num_planes != 1) {
2645                 ret = -EBUSY;
2646                 goto err_reqbufs;
2647         }
2648
2649         /*
2650          * Get kernel address of each buffer.
2651          */
2652         for (i = 0; i < q->num_buffers; i++) {
2653                 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2654                 if (fileio->bufs[i].vaddr == NULL) {
2655                         ret = -EINVAL;
2656                         goto err_reqbufs;
2657                 }
2658                 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2659         }
2660
2661         /*
2662          * Read mode requires pre queuing of all buffers.
2663          */
2664         if (read) {
2665                 /*
2666                  * Queue all buffers.
2667                  */
2668                 for (i = 0; i < q->num_buffers; i++) {
2669                         ret = vb2_core_qbuf(q, i, NULL, NULL);
2670                         if (ret)
2671                                 goto err_reqbufs;
2672                         fileio->bufs[i].queued = 1;
2673                 }
2674                 /*
2675                  * All buffers have been queued, so mark that by setting
2676                  * initial_index to q->num_buffers
2677                  */
2678                 fileio->initial_index = q->num_buffers;
2679                 fileio->cur_index = q->num_buffers;
2680         }
2681
2682         /*
2683          * Start streaming.
2684          */
2685         ret = vb2_core_streamon(q, q->type);
2686         if (ret)
2687                 goto err_reqbufs;
2688
2689         return ret;
2690
2691 err_reqbufs:
2692         fileio->count = 0;
2693         vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
2694
2695 err_kfree:
2696         q->fileio = NULL;
2697         kfree(fileio);
2698         return ret;
2699 }
2700
2701 /*
2702  * __vb2_cleanup_fileio() - free resourced used by file io emulator
2703  * @q:          videobuf2 queue
2704  */
2705 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2706 {
2707         struct vb2_fileio_data *fileio = q->fileio;
2708
2709         if (fileio) {
2710                 vb2_core_streamoff(q, q->type);
2711                 q->fileio = NULL;
2712                 fileio->count = 0;
2713                 vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
2714                 kfree(fileio);
2715                 dprintk(q, 3, "file io emulator closed\n");
2716         }
2717         return 0;
2718 }
2719
2720 /*
2721  * __vb2_perform_fileio() - perform a single file io (read or write) operation
2722  * @q:          videobuf2 queue
2723  * @data:       pointed to target userspace buffer
2724  * @count:      number of bytes to read or write
2725  * @ppos:       file handle position tracking pointer
2726  * @nonblock:   mode selector (1 means blocking calls, 0 means nonblocking)
2727  * @read:       access mode selector (1 means read, 0 means write)
2728  */
2729 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2730                 loff_t *ppos, int nonblock, int read)
2731 {
2732         struct vb2_fileio_data *fileio;
2733         struct vb2_fileio_buf *buf;
2734         bool is_multiplanar = q->is_multiplanar;
2735         /*
2736          * When using write() to write data to an output video node the vb2 core
2737          * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2738          * else is able to provide this information with the write() operation.
2739          */
2740         bool copy_timestamp = !read && q->copy_timestamp;
2741         unsigned index;
2742         int ret;
2743
2744         dprintk(q, 3, "mode %s, offset %ld, count %zd, %sblocking\n",
2745                 read ? "read" : "write", (long)*ppos, count,
2746                 nonblock ? "non" : "");
2747
2748         if (!data)
2749                 return -EINVAL;
2750
2751         if (q->waiting_in_dqbuf) {
2752                 dprintk(q, 3, "another dup()ped fd is %s\n",
2753                         read ? "reading" : "writing");
2754                 return -EBUSY;
2755         }
2756
2757         /*
2758          * Initialize emulator on first call.
2759          */
2760         if (!vb2_fileio_is_active(q)) {
2761                 ret = __vb2_init_fileio(q, read);
2762                 dprintk(q, 3, "vb2_init_fileio result: %d\n", ret);
2763                 if (ret)
2764                         return ret;
2765         }
2766         fileio = q->fileio;
2767
2768         /*
2769          * Check if we need to dequeue the buffer.
2770          */
2771         index = fileio->cur_index;
2772         if (index >= q->num_buffers) {
2773                 struct vb2_buffer *b;
2774
2775                 /*
2776                  * Call vb2_dqbuf to get buffer back.
2777                  */
2778                 ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2779                 dprintk(q, 5, "vb2_dqbuf result: %d\n", ret);
2780                 if (ret)
2781                         return ret;
2782                 fileio->dq_count += 1;
2783
2784                 fileio->cur_index = index;
2785                 buf = &fileio->bufs[index];
2786                 b = q->bufs[index];
2787
2788                 /*
2789                  * Get number of bytes filled by the driver
2790                  */
2791                 buf->pos = 0;
2792                 buf->queued = 0;
2793                 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2794                                  : vb2_plane_size(q->bufs[index], 0);
2795                 /* Compensate for data_offset on read in the multiplanar case. */
2796                 if (is_multiplanar && read &&
2797                                 b->planes[0].data_offset < buf->size) {
2798                         buf->pos = b->planes[0].data_offset;
2799                         buf->size -= buf->pos;
2800                 }
2801         } else {
2802                 buf = &fileio->bufs[index];
2803         }
2804
2805         /*
2806          * Limit count on last few bytes of the buffer.
2807          */
2808         if (buf->pos + count > buf->size) {
2809                 count = buf->size - buf->pos;
2810                 dprintk(q, 5, "reducing read count: %zd\n", count);
2811         }
2812
2813         /*
2814          * Transfer data to userspace.
2815          */
2816         dprintk(q, 3, "copying %zd bytes - buffer %d, offset %u\n",
2817                 count, index, buf->pos);
2818         if (read)
2819                 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2820         else
2821                 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2822         if (ret) {
2823                 dprintk(q, 3, "error copying data\n");
2824                 return -EFAULT;
2825         }
2826
2827         /*
2828          * Update counters.
2829          */
2830         buf->pos += count;
2831         *ppos += count;
2832
2833         /*
2834          * Queue next buffer if required.
2835          */
2836         if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2837                 struct vb2_buffer *b = q->bufs[index];
2838
2839                 /*
2840                  * Check if this is the last buffer to read.
2841                  */
2842                 if (read && fileio->read_once && fileio->dq_count == 1) {
2843                         dprintk(q, 3, "read limit reached\n");
2844                         return __vb2_cleanup_fileio(q);
2845                 }
2846
2847                 /*
2848                  * Call vb2_qbuf and give buffer to the driver.
2849                  */
2850                 b->planes[0].bytesused = buf->pos;
2851
2852                 if (copy_timestamp)
2853                         b->timestamp = ktime_get_ns();
2854                 ret = vb2_core_qbuf(q, index, NULL, NULL);
2855                 dprintk(q, 5, "vb2_dbuf result: %d\n", ret);
2856                 if (ret)
2857                         return ret;
2858
2859                 /*
2860                  * Buffer has been queued, update the status
2861                  */
2862                 buf->pos = 0;
2863                 buf->queued = 1;
2864                 buf->size = vb2_plane_size(q->bufs[index], 0);
2865                 fileio->q_count += 1;
2866                 /*
2867                  * If we are queuing up buffers for the first time, then
2868                  * increase initial_index by one.
2869                  */
2870                 if (fileio->initial_index < q->num_buffers)
2871                         fileio->initial_index++;
2872                 /*
2873                  * The next buffer to use is either a buffer that's going to be
2874                  * queued for the first time (initial_index < q->num_buffers)
2875                  * or it is equal to q->num_buffers, meaning that the next
2876                  * time we need to dequeue a buffer since we've now queued up
2877                  * all the 'first time' buffers.
2878                  */
2879                 fileio->cur_index = fileio->initial_index;
2880         }
2881
2882         /*
2883          * Return proper number of bytes processed.
2884          */
2885         if (ret == 0)
2886                 ret = count;
2887         return ret;
2888 }
2889
2890 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2891                 loff_t *ppos, int nonblocking)
2892 {
2893         return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2894 }
2895 EXPORT_SYMBOL_GPL(vb2_read);
2896
2897 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2898                 loff_t *ppos, int nonblocking)
2899 {
2900         return __vb2_perform_fileio(q, (char __user *) data, count,
2901                                                         ppos, nonblocking, 0);
2902 }
2903 EXPORT_SYMBOL_GPL(vb2_write);
2904
2905 struct vb2_threadio_data {
2906         struct task_struct *thread;
2907         vb2_thread_fnc fnc;
2908         void *priv;
2909         bool stop;
2910 };
2911
2912 static int vb2_thread(void *data)
2913 {
2914         struct vb2_queue *q = data;
2915         struct vb2_threadio_data *threadio = q->threadio;
2916         bool copy_timestamp = false;
2917         unsigned prequeue = 0;
2918         unsigned index = 0;
2919         int ret = 0;
2920
2921         if (q->is_output) {
2922                 prequeue = q->num_buffers;
2923                 copy_timestamp = q->copy_timestamp;
2924         }
2925
2926         set_freezable();
2927
2928         for (;;) {
2929                 struct vb2_buffer *vb;
2930
2931                 /*
2932                  * Call vb2_dqbuf to get buffer back.
2933                  */
2934                 if (prequeue) {
2935                         vb = q->bufs[index++];
2936                         prequeue--;
2937                 } else {
2938                         call_void_qop(q, wait_finish, q);
2939                         if (!threadio->stop)
2940                                 ret = vb2_core_dqbuf(q, &index, NULL, 0);
2941                         call_void_qop(q, wait_prepare, q);
2942                         dprintk(q, 5, "file io: vb2_dqbuf result: %d\n", ret);
2943                         if (!ret)
2944                                 vb = q->bufs[index];
2945                 }
2946                 if (ret || threadio->stop)
2947                         break;
2948                 try_to_freeze();
2949
2950                 if (vb->state != VB2_BUF_STATE_ERROR)
2951                         if (threadio->fnc(vb, threadio->priv))
2952                                 break;
2953                 call_void_qop(q, wait_finish, q);
2954                 if (copy_timestamp)
2955                         vb->timestamp = ktime_get_ns();
2956                 if (!threadio->stop)
2957                         ret = vb2_core_qbuf(q, vb->index, NULL, NULL);
2958                 call_void_qop(q, wait_prepare, q);
2959                 if (ret || threadio->stop)
2960                         break;
2961         }
2962
2963         /* Hmm, linux becomes *very* unhappy without this ... */
2964         while (!kthread_should_stop()) {
2965                 set_current_state(TASK_INTERRUPTIBLE);
2966                 schedule();
2967         }
2968         return 0;
2969 }
2970
2971 /*
2972  * This function should not be used for anything else but the videobuf2-dvb
2973  * support. If you think you have another good use-case for this, then please
2974  * contact the linux-media mailinglist first.
2975  */
2976 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
2977                      const char *thread_name)
2978 {
2979         struct vb2_threadio_data *threadio;
2980         int ret = 0;
2981
2982         if (q->threadio)
2983                 return -EBUSY;
2984         if (vb2_is_busy(q))
2985                 return -EBUSY;
2986         if (WARN_ON(q->fileio))
2987                 return -EBUSY;
2988
2989         threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
2990         if (threadio == NULL)
2991                 return -ENOMEM;
2992         threadio->fnc = fnc;
2993         threadio->priv = priv;
2994
2995         ret = __vb2_init_fileio(q, !q->is_output);
2996         dprintk(q, 3, "file io: vb2_init_fileio result: %d\n", ret);
2997         if (ret)
2998                 goto nomem;
2999         q->threadio = threadio;
3000         threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
3001         if (IS_ERR(threadio->thread)) {
3002                 ret = PTR_ERR(threadio->thread);
3003                 threadio->thread = NULL;
3004                 goto nothread;
3005         }
3006         return 0;
3007
3008 nothread:
3009         __vb2_cleanup_fileio(q);
3010 nomem:
3011         kfree(threadio);
3012         return ret;
3013 }
3014 EXPORT_SYMBOL_GPL(vb2_thread_start);
3015
3016 int vb2_thread_stop(struct vb2_queue *q)
3017 {
3018         struct vb2_threadio_data *threadio = q->threadio;
3019         int err;
3020
3021         if (threadio == NULL)
3022                 return 0;
3023         threadio->stop = true;
3024         /* Wake up all pending sleeps in the thread */
3025         vb2_queue_error(q);
3026         err = kthread_stop(threadio->thread);
3027         __vb2_cleanup_fileio(q);
3028         threadio->thread = NULL;
3029         kfree(threadio);
3030         q->threadio = NULL;
3031         return err;
3032 }
3033 EXPORT_SYMBOL_GPL(vb2_thread_stop);
3034
3035 MODULE_DESCRIPTION("Media buffer core framework");
3036 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3037 MODULE_LICENSE("GPL");
3038 MODULE_IMPORT_NS(DMA_BUF);