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 #define PLANE_INDEX_BITS        3
  35 #define PLANE_INDEX_SHIFT       (PAGE_SHIFT + PLANE_INDEX_BITS)
  36 #define PLANE_INDEX_MASK        (BIT_MASK(PLANE_INDEX_BITS) - 1)
  37 #define MAX_BUFFER_INDEX        BIT_MASK(30 - PLANE_INDEX_SHIFT)
  38 #define BUFFER_INDEX_MASK       (MAX_BUFFER_INDEX - 1)
  39
  40 #if BIT(PLANE_INDEX_BITS) != VIDEO_MAX_PLANES
  41 #error PLANE_INDEX_BITS order must be equal to VIDEO_MAX_PLANES
  42 #endif
  43
  44 static int debug;
  45 module_param(debug, int, 0644);
  46
  47 #define dprintk(q, level, fmt, arg...)                                  \
  48         do {                                                            \
  49                 if (debug >= level)                                     \
  50                         pr_info("[%s] %s: " fmt, (q)->name, __func__,   \
  51                                 ## arg);                                \
  52         } while (0)
  53
  54 #ifdef CONFIG_VIDEO_ADV_DEBUG
  55
  56 /*
  57  * If advanced debugging is on, then count how often each op is called
  58  * successfully, which can either be per-buffer or per-queue.
  59  *
  60  * This makes it easy to check that the 'init' and 'cleanup'
  61  * (and variations thereof) stay balanced.
  62  */
  63
  64 #define log_memop(vb, op)                                               \
  65         dprintk((vb)->vb2_queue, 2, "call_memop(%d, %s)%s\n",           \
  66                 (vb)->index, #op,                                       \
  67                 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
  68
  69 #define call_memop(vb, op, args...)                                     \
  70 ({                                                                      \
  71         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  72         int err;                                                        \
  73                                                                         \
  74         log_memop(vb, op);                                              \
  75         err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0;              \
  76         if (!err)                                                       \
  77                 (vb)->cnt_mem_ ## op++;                                 \
  78         err;                                                            \
  79 })
  80
  81 #define call_ptr_memop(op, vb, args...)                                 \
  82 ({                                                                      \
  83         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  84         void *ptr;                                                      \
  85                                                                         \
  86         log_memop(vb, op);                                              \
  87         ptr = _q->mem_ops->op ? _q->mem_ops->op(vb, args) : NULL;       \
  88         if (!IS_ERR_OR_NULL(ptr))                                       \
  89                 (vb)->cnt_mem_ ## op++;                                 \
  90         ptr;                                                            \
  91 })
  92
  93 #define call_void_memop(vb, op, args...)                                \
  94 ({                                                                      \
  95         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  96                                                                         \
  97         log_memop(vb, op);                                              \
  98         if (_q->mem_ops->op)                                            \
  99                 _q->mem_ops->op(args);                                  \
 100         (vb)->cnt_mem_ ## op++;                                         \
 101 })
 102
 103 #define log_qop(q, op)                                                  \
 104         dprintk(q, 2, "call_qop(%s)%s\n", #op,                          \
 105                 (q)->ops->op ? "" : " (nop)")
 106
 107 #define call_qop(q, op, args...)                                        \
 108 ({                                                                      \
 109         int err;                                                        \
 110                                                                         \
 111         log_qop(q, op);                                                 \
 112         err = (q)->ops->op ? (q)->ops->op(args) : 0;                    \
 113         if (!err)                                                       \
 114                 (q)->cnt_ ## op++;                                      \
 115         err;                                                            \
 116 })
 117
 118 #define call_void_qop(q, op, args...)                                   \
 119 ({                                                                      \
 120         log_qop(q, op);                                                 \
 121         if ((q)->ops->op)                                               \
 122                 (q)->ops->op(args);                                     \
 123         (q)->cnt_ ## op++;                                              \
 124 })
 125
 126 #define log_vb_qop(vb, op, args...)                                     \
 127         dprintk((vb)->vb2_queue, 2, "call_vb_qop(%d, %s)%s\n",          \
 128                 (vb)->index, #op,                                       \
 129                 (vb)->vb2_queue->ops->op ? "" : " (nop)")
 130
 131 #define call_vb_qop(vb, op, args...)                                    \
 132 ({                                                                      \
 133         int err;                                                        \
 134                                                                         \
 135         log_vb_qop(vb, op);                                             \
 136         err = (vb)->vb2_queue->ops->op ?                                \
 137                 (vb)->vb2_queue->ops->op(args) : 0;                     \
 138         if (!err)                                                       \
 139                 (vb)->cnt_ ## op++;                                     \
 140         err;                                                            \
 141 })
 142
 143 #define call_void_vb_qop(vb, op, args...)                               \
 144 ({                                                                      \
 145         log_vb_qop(vb, op);                                             \
 146         if ((vb)->vb2_queue->ops->op)                                   \
 147                 (vb)->vb2_queue->ops->op(args);                         \
 148         (vb)->cnt_ ## op++;                                             \
 149 })
 150
 151 #else
 152
 153 #define call_memop(vb, op, args...)                                     \
 154         ((vb)->vb2_queue->mem_ops->op ?                                 \
 155                 (vb)->vb2_queue->mem_ops->op(args) : 0)
 156
 157 #define call_ptr_memop(op, vb, args...)                                 \
 158         ((vb)->vb2_queue->mem_ops->op ?                                 \
 159                 (vb)->vb2_queue->mem_ops->op(vb, args) : NULL)
 160
 161 #define call_void_memop(vb, op, args...)                                \
 162         do {                                                            \
 163                 if ((vb)->vb2_queue->mem_ops->op)                       \
 164                         (vb)->vb2_queue->mem_ops->op(args);             \
 165         } while (0)
 166
 167 #define call_qop(q, op, args...)                                        \
 168         ((q)->ops->op ? (q)->ops->op(args) : 0)
 169
 170 #define call_void_qop(q, op, args...)                                   \
 171         do {                                                            \
 172                 if ((q)->ops->op)                                       \
 173                         (q)->ops->op(args);                             \
 174         } while (0)
 175
 176 #define call_vb_qop(vb, op, args...)                                    \
 177         ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
 178
 179 #define call_void_vb_qop(vb, op, args...)                               \
 180         do {                                                            \
 181                 if ((vb)->vb2_queue->ops->op)                           \
 182                         (vb)->vb2_queue->ops->op(args);                 \
 183         } while (0)
 184
 185 #endif
 186
 187 #define call_bufop(q, op, args...)                                      \
 188 ({                                                                      \
 189         int ret = 0;                                                    \
 190         if (q && q->buf_ops && q->buf_ops->op)                          \
 191                 ret = q->buf_ops->op(args);                             \
 192         ret;                                                            \
 193 })
 194
 195 #define call_void_bufop(q, op, args...)                                 \
 196 ({                                                                      \
 197         if (q && q->buf_ops && q->buf_ops->op)                          \
 198                 q->buf_ops->op(args);                                   \
 199 })
 200
 201 static void __vb2_queue_cancel(struct vb2_queue *q);
 202 static void __enqueue_in_driver(struct vb2_buffer *vb);
 203
 204 static const char *vb2_state_name(enum vb2_buffer_state s)
 205 {
 206         static const char * const state_names[] = {
 207                 [VB2_BUF_STATE_DEQUEUED] = "dequeued",
 208                 [VB2_BUF_STATE_IN_REQUEST] = "in request",
 209                 [VB2_BUF_STATE_PREPARING] = "preparing",
 210                 [VB2_BUF_STATE_QUEUED] = "queued",
 211                 [VB2_BUF_STATE_ACTIVE] = "active",
 212                 [VB2_BUF_STATE_DONE] = "done",
 213                 [VB2_BUF_STATE_ERROR] = "error",
 214         };
 215
 216         if ((unsigned int)(s) < ARRAY_SIZE(state_names))
 217                 return state_names[s];
 218         return "unknown";
 219 }
 220
 221 /*
 222  * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
 223  */
 224 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
 225 {
 226         struct vb2_queue *q = vb->vb2_queue;
 227         void *mem_priv;
 228         int plane;
 229         int ret = -ENOMEM;
 230
 231         /*
 232          * Allocate memory for all planes in this buffer
 233          * NOTE: mmapped areas should be page aligned
 234          */
 235         for (plane = 0; plane < vb->num_planes; ++plane) {
 236                 /* Memops alloc requires size to be page aligned. */
 237                 unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
 238
 239                 /* Did it wrap around? */
 240                 if (size < vb->planes[plane].length)
 241                         goto free;
 242
 243                 mem_priv = call_ptr_memop(alloc,
 244                                           vb,
 245                                           q->alloc_devs[plane] ? : q->dev,
 246                                           size);
 247                 if (IS_ERR_OR_NULL(mem_priv)) {
 248                         if (mem_priv)
 249                                 ret = PTR_ERR(mem_priv);
 250                         goto free;
 251                 }
 252
 253                 /* Associate allocator private data with this plane */
 254                 vb->planes[plane].mem_priv = mem_priv;
 255         }
 256
 257         return 0;
 258 free:
 259         /* Free already allocated memory if one of the allocations failed */
 260         for (; plane > 0; --plane) {
 261                 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
 262                 vb->planes[plane - 1].mem_priv = NULL;
 263         }
 264
 265         return ret;
 266 }
 267
 268 /*
 269  * __vb2_buf_mem_free() - free memory of the given buffer
 270  */
 271 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
 272 {
 273         unsigned int plane;
 274
 275         for (plane = 0; plane < vb->num_planes; ++plane) {
 276                 call_void_memop(vb, put, vb->planes[plane].mem_priv);
 277                 vb->planes[plane].mem_priv = NULL;
 278                 dprintk(vb->vb2_queue, 3, "freed plane %d of buffer %d\n",
 279                         plane, vb->index);
 280         }
 281 }
 282
 283 /*
 284  * __vb2_buf_userptr_put() - release userspace memory associated with
 285  * a USERPTR buffer
 286  */
 287 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
 288 {
 289         unsigned int plane;
 290
 291         for (plane = 0; plane < vb->num_planes; ++plane) {
 292                 if (vb->planes[plane].mem_priv)
 293                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
 294                 vb->planes[plane].mem_priv = NULL;
 295         }
 296 }
 297
 298 /*
 299  * __vb2_plane_dmabuf_put() - release memory associated with
 300  * a DMABUF shared plane
 301  */
 302 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
 303 {
 304         if (!p->mem_priv)
 305                 return;
 306
 307         if (p->dbuf_mapped)
 308                 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
 309
 310         call_void_memop(vb, detach_dmabuf, p->mem_priv);
 311         dma_buf_put(p->dbuf);
 312         p->mem_priv = NULL;
 313         p->dbuf = NULL;
 314         p->dbuf_mapped = 0;
 315 }
 316
 317 /*
 318  * __vb2_buf_dmabuf_put() - release memory associated with
 319  * a DMABUF shared buffer
 320  */
 321 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
 322 {
 323         unsigned int plane;
 324
 325         for (plane = 0; plane < vb->num_planes; ++plane)
 326                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
 327 }
 328
 329 /*
 330  * __vb2_buf_mem_prepare() - call ->prepare() on buffer's private memory
 331  * to sync caches
 332  */
 333 static void __vb2_buf_mem_prepare(struct vb2_buffer *vb)
 334 {
 335         unsigned int plane;
 336
 337         if (vb->synced)
 338                 return;
 339
 340         vb->synced = 1;
 341         for (plane = 0; plane < vb->num_planes; ++plane)
 342                 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
 343 }
 344
 345 /*
 346  * __vb2_buf_mem_finish() - call ->finish on buffer's private memory
 347  * to sync caches
 348  */
 349 static void __vb2_buf_mem_finish(struct vb2_buffer *vb)
 350 {
 351         unsigned int plane;
 352
 353         if (!vb->synced)
 354                 return;
 355
 356         vb->synced = 0;
 357         for (plane = 0; plane < vb->num_planes; ++plane)
 358                 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
 359 }
 360
 361 /*
 362  * __setup_offsets() - setup unique offsets ("cookies") for every plane in
 363  * the buffer.
 364  */
 365 static void __setup_offsets(struct vb2_buffer *vb)
 366 {
 367         struct vb2_queue *q = vb->vb2_queue;
 368         unsigned int plane;
 369         unsigned long offset = 0;
 370
 371         /*
 372          * The offset "cookie" value has the following constraints:
 373          * - a buffer can have up to 8 planes.
 374          * - v4l2 mem2mem uses bit 30 to distinguish between
 375          *   OUTPUT (aka "source", bit 30 is 0) and
 376          *   CAPTURE (aka "destination", bit 30 is 1) buffers.
 377          * - must be page aligned
 378          * That led to this bit mapping when PAGE_SHIFT = 12:
 379          * |30                |29        15|14       12|11 0|
 380          * |DST_QUEUE_OFF_BASE|buffer index|plane index| 0  |
 381          * where there are 15 bits to store the buffer index.
 382          * Depending on PAGE_SHIFT value we can have fewer bits
 383          * to store the buffer index.
 384          */
 385         offset = vb->index << PLANE_INDEX_SHIFT;
 386
 387         for (plane = 0; plane < vb->num_planes; ++plane) {
 388                 vb->planes[plane].m.offset = offset + (plane << PAGE_SHIFT);
 389
 390                 dprintk(q, 3, "buffer %d, plane %d offset 0x%08lx\n",
 391                                 vb->index, plane, offset);
 392         }
 393 }
 394
 395 static void init_buffer_cache_hints(struct vb2_queue *q, struct vb2_buffer *vb)
 396 {
 397         /*
 398          * DMA exporter should take care of cache syncs, so we can avoid
 399          * explicit ->prepare()/->finish() syncs. For other ->memory types
 400          * we always need ->prepare() or/and ->finish() cache sync.
 401          */
 402         if (q->memory == VB2_MEMORY_DMABUF) {
 403                 vb->skip_cache_sync_on_finish = 1;
 404                 vb->skip_cache_sync_on_prepare = 1;
 405                 return;
 406         }
 407
 408         /*
 409          * ->finish() cache sync can be avoided when queue direction is
 410          * TO_DEVICE.
 411          */
 412         if (q->dma_dir == DMA_TO_DEVICE)
 413                 vb->skip_cache_sync_on_finish = 1;
 414 }
 415
 416 /**
 417  * vb2_queue_add_buffer() - add a buffer to a queue
 418  * @q:  pointer to &struct vb2_queue with videobuf2 queue.
 419  * @vb: pointer to &struct vb2_buffer to be added to the queue.
 420  * @index: index where add vb2_buffer in the queue
 421  */
 422 static void vb2_queue_add_buffer(struct vb2_queue *q, struct vb2_buffer *vb, unsigned int index)
 423 {
 424         WARN_ON(index >= q->max_num_buffers || q->bufs[index] || vb->vb2_queue);
 425
 426         q->bufs[index] = vb;
 427         vb->index = index;
 428         vb->vb2_queue = q;
 429 }
 430
 431 /**
 432  * vb2_queue_remove_buffer() - remove a buffer from a queue
 433  * @vb: pointer to &struct vb2_buffer to be removed from the queue.
 434  */
 435 static void vb2_queue_remove_buffer(struct vb2_buffer *vb)
 436 {
 437         vb->vb2_queue->bufs[vb->index] = NULL;
 438         vb->vb2_queue = NULL;
 439 }
 440
 441 /*
 442  * __vb2_queue_alloc() - allocate vb2 buffer structures and (for MMAP type)
 443  * video buffer memory for all buffers/planes on the queue and initializes the
 444  * queue
 445  *
 446  * Returns the number of buffers successfully allocated.
 447  */
 448 static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
 449                              unsigned int num_buffers, unsigned int num_planes,
 450                              const unsigned plane_sizes[VB2_MAX_PLANES])
 451 {
 452         unsigned int q_num_buffers = vb2_get_num_buffers(q);
 453         unsigned int buffer, plane;
 454         struct vb2_buffer *vb;
 455         int ret;
 456
 457         /*
 458          * Ensure that the number of already queue + the number of buffers already
 459          * in the queue is below q->max_num_buffers
 460          */
 461         num_buffers = min_t(unsigned int, num_buffers,
 462                             q->max_num_buffers - q_num_buffers);
 463
 464         for (buffer = 0; buffer < num_buffers; ++buffer) {
 465                 /* Allocate vb2 buffer structures */
 466                 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
 467                 if (!vb) {
 468                         dprintk(q, 1, "memory alloc for buffer struct failed\n");
 469                         break;
 470                 }
 471
 472                 vb->state = VB2_BUF_STATE_DEQUEUED;
 473                 vb->num_planes = num_planes;
 474                 vb->type = q->type;
 475                 vb->memory = memory;
 476                 init_buffer_cache_hints(q, vb);
 477                 for (plane = 0; plane < num_planes; ++plane) {
 478                         vb->planes[plane].length = plane_sizes[plane];
 479                         vb->planes[plane].min_length = plane_sizes[plane];
 480                 }
 481
 482                 vb2_queue_add_buffer(q, vb, q_num_buffers + buffer);
 483                 call_void_bufop(q, init_buffer, vb);
 484
 485                 /* Allocate video buffer memory for the MMAP type */
 486                 if (memory == VB2_MEMORY_MMAP) {
 487                         ret = __vb2_buf_mem_alloc(vb);
 488                         if (ret) {
 489                                 dprintk(q, 1, "failed allocating memory for buffer %d\n",
 490                                         buffer);
 491                                 vb2_queue_remove_buffer(vb);
 492                                 kfree(vb);
 493                                 break;
 494                         }
 495                         __setup_offsets(vb);
 496                         /*
 497                          * Call the driver-provided buffer initialization
 498                          * callback, if given. An error in initialization
 499                          * results in queue setup failure.
 500                          */
 501                         ret = call_vb_qop(vb, buf_init, vb);
 502                         if (ret) {
 503                                 dprintk(q, 1, "buffer %d %p initialization failed\n",
 504                                         buffer, vb);
 505                                 __vb2_buf_mem_free(vb);
 506                                 vb2_queue_remove_buffer(vb);
 507                                 kfree(vb);
 508                                 break;
 509                         }
 510                 }
 511         }
 512
 513         dprintk(q, 3, "allocated %d buffers, %d plane(s) each\n",
 514                 buffer, num_planes);
 515
 516         return buffer;
 517 }
 518
 519 /*
 520  * __vb2_free_mem() - release all video buffer memory for a given queue
 521  */
 522 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
 523 {
 524         unsigned int buffer;
 525         struct vb2_buffer *vb;
 526         unsigned int q_num_buffers = vb2_get_num_buffers(q);
 527
 528         for (buffer = q_num_buffers - buffers; buffer < q_num_buffers;
 529              ++buffer) {
 530                 vb = vb2_get_buffer(q, buffer);
 531                 if (!vb)
 532                         continue;
 533
 534                 /* Free MMAP buffers or release USERPTR buffers */
 535                 if (q->memory == VB2_MEMORY_MMAP)
 536                         __vb2_buf_mem_free(vb);
 537                 else if (q->memory == VB2_MEMORY_DMABUF)
 538                         __vb2_buf_dmabuf_put(vb);
 539                 else
 540                         __vb2_buf_userptr_put(vb);
 541         }
 542 }
 543
 544 /*
 545  * __vb2_queue_free() - free buffers at the end of the queue - video memory and
 546  * related information, if no buffers are left return the queue to an
 547  * uninitialized state. Might be called even if the queue has already been freed.
 548  */
 549 static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
 550 {
 551         unsigned int buffer;
 552         unsigned int q_num_buffers = vb2_get_num_buffers(q);
 553
 554         lockdep_assert_held(&q->mmap_lock);
 555
 556         /* Call driver-provided cleanup function for each buffer, if provided */
 557         for (buffer = q_num_buffers - buffers; buffer < q_num_buffers;
 558              ++buffer) {
 559                 struct vb2_buffer *vb = vb2_get_buffer(q, buffer);
 560
 561                 if (vb && vb->planes[0].mem_priv)
 562                         call_void_vb_qop(vb, buf_cleanup, vb);
 563         }
 564
 565         /* Release video buffer memory */
 566         __vb2_free_mem(q, buffers);
 567
 568 #ifdef CONFIG_VIDEO_ADV_DEBUG
 569         /*
 570          * Check that all the calls were balanced during the life-time of this
 571          * queue. If not then dump the counters to the kernel log.
 572          */
 573         if (q_num_buffers) {
 574                 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
 575                                   q->cnt_prepare_streaming != q->cnt_unprepare_streaming ||
 576                                   q->cnt_wait_prepare != q->cnt_wait_finish;
 577
 578                 if (unbalanced) {
 579                         pr_info("unbalanced counters for queue %p:\n", q);
 580                         if (q->cnt_start_streaming != q->cnt_stop_streaming)
 581                                 pr_info("     setup: %u start_streaming: %u stop_streaming: %u\n",
 582                                         q->cnt_queue_setup, q->cnt_start_streaming,
 583                                         q->cnt_stop_streaming);
 584                         if (q->cnt_prepare_streaming != q->cnt_unprepare_streaming)
 585                                 pr_info("     prepare_streaming: %u unprepare_streaming: %u\n",
 586                                         q->cnt_prepare_streaming, q->cnt_unprepare_streaming);
 587                         if (q->cnt_wait_prepare != q->cnt_wait_finish)
 588                                 pr_info("     wait_prepare: %u wait_finish: %u\n",
 589                                         q->cnt_wait_prepare, q->cnt_wait_finish);
 590                 }
 591                 q->cnt_queue_setup = 0;
 592                 q->cnt_wait_prepare = 0;
 593                 q->cnt_wait_finish = 0;
 594                 q->cnt_prepare_streaming = 0;
 595                 q->cnt_start_streaming = 0;
 596                 q->cnt_stop_streaming = 0;
 597                 q->cnt_unprepare_streaming = 0;
 598         }
 599         for (buffer = 0; buffer < vb2_get_num_buffers(q); buffer++) {
 600                 struct vb2_buffer *vb = vb2_get_buffer(q, buffer);
 601                 bool unbalanced;
 602
 603                 if (!vb)
 604                         continue;
 605
 606                 unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
 607                              vb->cnt_mem_prepare != vb->cnt_mem_finish ||
 608                              vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
 609                              vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
 610                              vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
 611                              vb->cnt_buf_queue != vb->cnt_buf_done ||
 612                              vb->cnt_buf_prepare != vb->cnt_buf_finish ||
 613                              vb->cnt_buf_init != vb->cnt_buf_cleanup;
 614
 615                 if (unbalanced) {
 616                         pr_info("unbalanced counters for queue %p, buffer %d:\n",
 617                                 q, buffer);
 618                         if (vb->cnt_buf_init != vb->cnt_buf_cleanup)
 619                                 pr_info("     buf_init: %u buf_cleanup: %u\n",
 620                                         vb->cnt_buf_init, vb->cnt_buf_cleanup);
 621                         if (vb->cnt_buf_prepare != vb->cnt_buf_finish)
 622                                 pr_info("     buf_prepare: %u buf_finish: %u\n",
 623                                         vb->cnt_buf_prepare, vb->cnt_buf_finish);
 624                         if (vb->cnt_buf_queue != vb->cnt_buf_done)
 625                                 pr_info("     buf_out_validate: %u buf_queue: %u buf_done: %u buf_request_complete: %u\n",
 626                                         vb->cnt_buf_out_validate, vb->cnt_buf_queue,
 627                                         vb->cnt_buf_done, vb->cnt_buf_request_complete);
 628                         if (vb->cnt_mem_alloc != vb->cnt_mem_put)
 629                                 pr_info("     alloc: %u put: %u\n",
 630                                         vb->cnt_mem_alloc, vb->cnt_mem_put);
 631                         if (vb->cnt_mem_prepare != vb->cnt_mem_finish)
 632                                 pr_info("     prepare: %u finish: %u\n",
 633                                         vb->cnt_mem_prepare, vb->cnt_mem_finish);
 634                         if (vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr)
 635                                 pr_info("     get_userptr: %u put_userptr: %u\n",
 636                                         vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
 637                         if (vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf)
 638                                 pr_info("     attach_dmabuf: %u detach_dmabuf: %u\n",
 639                                         vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf);
 640                         if (vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf)
 641                                 pr_info("     map_dmabuf: %u unmap_dmabuf: %u\n",
 642                                         vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
 643                         pr_info("     get_dmabuf: %u num_users: %u\n",
 644                                 vb->cnt_mem_get_dmabuf,
 645                                 vb->cnt_mem_num_users);
 646                 }
 647         }
 648 #endif
 649
 650         /* Free vb2 buffers */
 651         for (buffer = q_num_buffers - buffers; buffer < q_num_buffers;
 652              ++buffer) {
 653                 struct vb2_buffer *vb = vb2_get_buffer(q, buffer);
 654
 655                 if (!vb)
 656                         continue;
 657
 658                 vb2_queue_remove_buffer(vb);
 659                 kfree(vb);
 660         }
 661
 662         q->num_buffers -= buffers;
 663         if (!vb2_get_num_buffers(q)) {
 664                 q->memory = VB2_MEMORY_UNKNOWN;
 665                 INIT_LIST_HEAD(&q->queued_list);
 666         }
 667 }
 668
 669 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
 670 {
 671         unsigned int plane;
 672         for (plane = 0; plane < vb->num_planes; ++plane) {
 673                 void *mem_priv = vb->planes[plane].mem_priv;
 674                 /*
 675                  * If num_users() has not been provided, call_memop
 676                  * will return 0, apparently nobody cares about this
 677                  * case anyway. If num_users() returns more than 1,
 678                  * we are not the only user of the plane's memory.
 679                  */
 680                 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
 681                         return true;
 682         }
 683         return false;
 684 }
 685 EXPORT_SYMBOL(vb2_buffer_in_use);
 686
 687 /*
 688  * __buffers_in_use() - return true if any buffers on the queue are in use and
 689  * the queue cannot be freed (by the means of REQBUFS(0)) call
 690  */
 691 static bool __buffers_in_use(struct vb2_queue *q)
 692 {
 693         unsigned int buffer;
 694         for (buffer = 0; buffer < vb2_get_num_buffers(q); ++buffer) {
 695                 struct vb2_buffer *vb = vb2_get_buffer(q, buffer);
 696
 697                 if (!vb)
 698                         continue;
 699
 700                 if (vb2_buffer_in_use(q, vb))
 701                         return true;
 702         }
 703         return false;
 704 }
 705
 706 void vb2_core_querybuf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb)
 707 {
 708         call_void_bufop(q, fill_user_buffer, vb, pb);
 709 }
 710 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
 711
 712 /*
 713  * __verify_userptr_ops() - verify that all memory operations required for
 714  * USERPTR queue type have been provided
 715  */
 716 static int __verify_userptr_ops(struct vb2_queue *q)
 717 {
 718         if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
 719             !q->mem_ops->put_userptr)
 720                 return -EINVAL;
 721
 722         return 0;
 723 }
 724
 725 /*
 726  * __verify_mmap_ops() - verify that all memory operations required for
 727  * MMAP queue type have been provided
 728  */
 729 static int __verify_mmap_ops(struct vb2_queue *q)
 730 {
 731         if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
 732             !q->mem_ops->put || !q->mem_ops->mmap)
 733                 return -EINVAL;
 734
 735         return 0;
 736 }
 737
 738 /*
 739  * __verify_dmabuf_ops() - verify that all memory operations required for
 740  * DMABUF queue type have been provided
 741  */
 742 static int __verify_dmabuf_ops(struct vb2_queue *q)
 743 {
 744         if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
 745             !q->mem_ops->detach_dmabuf  || !q->mem_ops->map_dmabuf ||
 746             !q->mem_ops->unmap_dmabuf)
 747                 return -EINVAL;
 748
 749         return 0;
 750 }
 751
 752 int vb2_verify_memory_type(struct vb2_queue *q,
 753                 enum vb2_memory memory, unsigned int type)
 754 {
 755         if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
 756             memory != VB2_MEMORY_DMABUF) {
 757                 dprintk(q, 1, "unsupported memory type\n");
 758                 return -EINVAL;
 759         }
 760
 761         if (type != q->type) {
 762                 dprintk(q, 1, "requested type is incorrect\n");
 763                 return -EINVAL;
 764         }
 765
 766         /*
 767          * Make sure all the required memory ops for given memory type
 768          * are available.
 769          */
 770         if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
 771                 dprintk(q, 1, "MMAP for current setup unsupported\n");
 772                 return -EINVAL;
 773         }
 774
 775         if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
 776                 dprintk(q, 1, "USERPTR for current setup unsupported\n");
 777                 return -EINVAL;
 778         }
 779
 780         if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
 781                 dprintk(q, 1, "DMABUF for current setup unsupported\n");
 782                 return -EINVAL;
 783         }
 784
 785         /*
 786          * Place the busy tests at the end: -EBUSY can be ignored when
 787          * create_bufs is called with count == 0, but count == 0 should still
 788          * do the memory and type validation.
 789          */
 790         if (vb2_fileio_is_active(q)) {
 791                 dprintk(q, 1, "file io in progress\n");
 792                 return -EBUSY;
 793         }
 794         return 0;
 795 }
 796 EXPORT_SYMBOL(vb2_verify_memory_type);
 797
 798 static void set_queue_coherency(struct vb2_queue *q, bool non_coherent_mem)
 799 {
 800         q->non_coherent_mem = 0;
 801
 802         if (!vb2_queue_allows_cache_hints(q))
 803                 return;
 804         q->non_coherent_mem = non_coherent_mem;
 805 }
 806
 807 static bool verify_coherency_flags(struct vb2_queue *q, bool non_coherent_mem)
 808 {
 809         if (non_coherent_mem != q->non_coherent_mem) {
 810                 dprintk(q, 1, "memory coherency model mismatch\n");
 811                 return false;
 812         }
 813         return true;
 814 }
 815
 816 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 817                      unsigned int flags, unsigned int *count)
 818 {
 819         unsigned int num_buffers, allocated_buffers, num_planes = 0;
 820         unsigned int q_num_bufs = vb2_get_num_buffers(q);
 821         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 822         bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
 823         unsigned int i;
 824         int ret = 0;
 825
 826         if (q->streaming) {
 827                 dprintk(q, 1, "streaming active\n");
 828                 return -EBUSY;
 829         }
 830
 831         if (q->waiting_in_dqbuf && *count) {
 832                 dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
 833                 return -EBUSY;
 834         }
 835
 836         if (*count == 0 || q_num_bufs != 0 ||
 837             (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory) ||
 838             !verify_coherency_flags(q, non_coherent_mem)) {
 839                 /*
 840                  * We already have buffers allocated, so first check if they
 841                  * are not in use and can be freed.
 842                  */
 843                 mutex_lock(&q->mmap_lock);
 844                 if (debug && q->memory == VB2_MEMORY_MMAP &&
 845                     __buffers_in_use(q))
 846                         dprintk(q, 1, "memory in use, orphaning buffers\n");
 847
 848                 /*
 849                  * Call queue_cancel to clean up any buffers in the
 850                  * QUEUED state which is possible if buffers were prepared or
 851                  * queued without ever calling STREAMON.
 852                  */
 853                 __vb2_queue_cancel(q);
 854                 __vb2_queue_free(q, q_num_bufs);
 855                 mutex_unlock(&q->mmap_lock);
 856
 857                 /*
 858                  * In case of REQBUFS(0) return immediately without calling
 859                  * driver's queue_setup() callback and allocating resources.
 860                  */
 861                 if (*count == 0)
 862                         return 0;
 863         }
 864
 865         /*
 866          * Make sure the requested values and current defaults are sane.
 867          */
 868         num_buffers = max_t(unsigned int, *count, q->min_queued_buffers);
 869         num_buffers = min_t(unsigned int, num_buffers, q->max_num_buffers);
 870         memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 871         /*
 872          * Set this now to ensure that drivers see the correct q->memory value
 873          * in the queue_setup op.
 874          */
 875         mutex_lock(&q->mmap_lock);
 876         if (!q->bufs)
 877                 q->bufs = kcalloc(q->max_num_buffers, sizeof(*q->bufs), GFP_KERNEL);
 878         if (!q->bufs)
 879                 ret = -ENOMEM;
 880         q->memory = memory;
 881         mutex_unlock(&q->mmap_lock);
 882         if (ret)
 883                 return ret;
 884         set_queue_coherency(q, non_coherent_mem);
 885
 886         /*
 887          * Ask the driver how many buffers and planes per buffer it requires.
 888          * Driver also sets the size and allocator context for each plane.
 889          */
 890         ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
 891                        plane_sizes, q->alloc_devs);
 892         if (ret)
 893                 goto error;
 894
 895         /* Check that driver has set sane values */
 896         if (WARN_ON(!num_planes)) {
 897                 ret = -EINVAL;
 898                 goto error;
 899         }
 900
 901         for (i = 0; i < num_planes; i++)
 902                 if (WARN_ON(!plane_sizes[i])) {
 903                         ret = -EINVAL;
 904                         goto error;
 905                 }
 906
 907         /* Finally, allocate buffers and video memory */
 908         allocated_buffers =
 909                 __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
 910         if (allocated_buffers == 0) {
 911                 dprintk(q, 1, "memory allocation failed\n");
 912                 ret = -ENOMEM;
 913                 goto error;
 914         }
 915
 916         /*
 917          * There is no point in continuing if we can't allocate the minimum
 918          * number of buffers needed by this vb2_queue.
 919          */
 920         if (allocated_buffers < q->min_queued_buffers)
 921                 ret = -ENOMEM;
 922
 923         /*
 924          * Check if driver can handle the allocated number of buffers.
 925          */
 926         if (!ret && allocated_buffers < num_buffers) {
 927                 num_buffers = allocated_buffers;
 928                 /*
 929                  * num_planes is set by the previous queue_setup(), but since it
 930                  * signals to queue_setup() whether it is called from create_bufs()
 931                  * vs reqbufs() we zero it here to signal that queue_setup() is
 932                  * called for the reqbufs() case.
 933                  */
 934                 num_planes = 0;
 935
 936                 ret = call_qop(q, queue_setup, q, &num_buffers,
 937                                &num_planes, plane_sizes, q->alloc_devs);
 938
 939                 if (!ret && allocated_buffers < num_buffers)
 940                         ret = -ENOMEM;
 941
 942                 /*
 943                  * Either the driver has accepted a smaller number of buffers,
 944                  * or .queue_setup() returned an error
 945                  */
 946         }
 947
 948         mutex_lock(&q->mmap_lock);
 949         q->num_buffers = allocated_buffers;
 950
 951         if (ret < 0) {
 952                 /*
 953                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 954                  * from already queued buffers and it will reset q->memory to
 955                  * VB2_MEMORY_UNKNOWN.
 956                  */
 957                 __vb2_queue_free(q, allocated_buffers);
 958                 mutex_unlock(&q->mmap_lock);
 959                 return ret;
 960         }
 961         mutex_unlock(&q->mmap_lock);
 962
 963         /*
 964          * Return the number of successfully allocated buffers
 965          * to the userspace.
 966          */
 967         *count = allocated_buffers;
 968         q->waiting_for_buffers = !q->is_output;
 969
 970         return 0;
 971
 972 error:
 973         mutex_lock(&q->mmap_lock);
 974         q->memory = VB2_MEMORY_UNKNOWN;
 975         mutex_unlock(&q->mmap_lock);
 976         return ret;
 977 }
 978 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
 979
 980 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 981                          unsigned int flags, unsigned int *count,
 982                          unsigned int requested_planes,
 983                          const unsigned int requested_sizes[])
 984 {
 985         unsigned int num_planes = 0, num_buffers, allocated_buffers;
 986         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 987         bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
 988         unsigned int q_num_bufs = vb2_get_num_buffers(q);
 989         bool no_previous_buffers = !q_num_bufs;
 990         int ret = 0;
 991
 992         if (q_num_bufs == q->max_num_buffers) {
 993                 dprintk(q, 1, "maximum number of buffers already allocated\n");
 994                 return -ENOBUFS;
 995         }
 996
 997         if (no_previous_buffers) {
 998                 if (q->waiting_in_dqbuf && *count) {
 999                         dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
1000                         return -EBUSY;
1001                 }
1002                 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
1003                 /*
1004                  * Set this now to ensure that drivers see the correct q->memory
1005                  * value in the queue_setup op.
1006                  */
1007                 mutex_lock(&q->mmap_lock);
1008                 q->memory = memory;
1009                 if (!q->bufs)
1010                         q->bufs = kcalloc(q->max_num_buffers, sizeof(*q->bufs), GFP_KERNEL);
1011                 if (!q->bufs)
1012                         ret = -ENOMEM;
1013                 mutex_unlock(&q->mmap_lock);
1014                 if (ret)
1015                         return ret;
1016                 q->waiting_for_buffers = !q->is_output;
1017                 set_queue_coherency(q, non_coherent_mem);
1018         } else {
1019                 if (q->memory != memory) {
1020                         dprintk(q, 1, "memory model mismatch\n");
1021                         return -EINVAL;
1022                 }
1023                 if (!verify_coherency_flags(q, non_coherent_mem))
1024                         return -EINVAL;
1025         }
1026
1027         num_buffers = min(*count, q->max_num_buffers - q_num_bufs);
1028
1029         if (requested_planes && requested_sizes) {
1030                 num_planes = requested_planes;
1031                 memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
1032         }
1033
1034         /*
1035          * Ask the driver, whether the requested number of buffers, planes per
1036          * buffer and their sizes are acceptable
1037          */
1038         ret = call_qop(q, queue_setup, q, &num_buffers,
1039                        &num_planes, plane_sizes, q->alloc_devs);
1040         if (ret)
1041                 goto error;
1042
1043         /* Finally, allocate buffers and video memory */
1044         allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
1045                                 num_planes, plane_sizes);
1046         if (allocated_buffers == 0) {
1047                 dprintk(q, 1, "memory allocation failed\n");
1048                 ret = -ENOMEM;
1049                 goto error;
1050         }
1051
1052         /*
1053          * Check if driver can handle the so far allocated number of buffers.
1054          */
1055         if (allocated_buffers < num_buffers) {
1056                 num_buffers = allocated_buffers;
1057
1058                 /*
1059                  * num_buffers contains the total number of buffers, that the
1060                  * queue driver has set up
1061                  */
1062                 ret = call_qop(q, queue_setup, q, &num_buffers,
1063                                &num_planes, plane_sizes, q->alloc_devs);
1064
1065                 if (!ret && allocated_buffers < num_buffers)
1066                         ret = -ENOMEM;
1067
1068                 /*
1069                  * Either the driver has accepted a smaller number of buffers,
1070                  * or .queue_setup() returned an error
1071                  */
1072         }
1073
1074         mutex_lock(&q->mmap_lock);
1075         q->num_buffers += allocated_buffers;
1076
1077         if (ret < 0) {
1078                 /*
1079                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
1080                  * from already queued buffers and it will reset q->memory to
1081                  * VB2_MEMORY_UNKNOWN.
1082                  */
1083                 __vb2_queue_free(q, allocated_buffers);
1084                 mutex_unlock(&q->mmap_lock);
1085                 return -ENOMEM;
1086         }
1087         mutex_unlock(&q->mmap_lock);
1088
1089         /*
1090          * Return the number of successfully allocated buffers
1091          * to the userspace.
1092          */
1093         *count = allocated_buffers;
1094
1095         return 0;
1096
1097 error:
1098         if (no_previous_buffers) {
1099                 mutex_lock(&q->mmap_lock);
1100                 q->memory = VB2_MEMORY_UNKNOWN;
1101                 mutex_unlock(&q->mmap_lock);
1102         }
1103         return ret;
1104 }
1105 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
1106
1107 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
1108 {
1109         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1110                 return NULL;
1111
1112         return call_ptr_memop(vaddr, vb, vb->planes[plane_no].mem_priv);
1113
1114 }
1115 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
1116
1117 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
1118 {
1119         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1120                 return NULL;
1121
1122         return call_ptr_memop(cookie, vb, vb->planes[plane_no].mem_priv);
1123 }
1124 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
1125
1126 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
1127 {
1128         struct vb2_queue *q = vb->vb2_queue;
1129         unsigned long flags;
1130
1131         if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
1132                 return;
1133
1134         if (WARN_ON(state != VB2_BUF_STATE_DONE &&
1135                     state != VB2_BUF_STATE_ERROR &&
1136                     state != VB2_BUF_STATE_QUEUED))
1137                 state = VB2_BUF_STATE_ERROR;
1138
1139 #ifdef CONFIG_VIDEO_ADV_DEBUG
1140         /*
1141          * Although this is not a callback, it still does have to balance
1142          * with the buf_queue op. So update this counter manually.
1143          */
1144         vb->cnt_buf_done++;
1145 #endif
1146         dprintk(q, 4, "done processing on buffer %d, state: %s\n",
1147                 vb->index, vb2_state_name(state));
1148
1149         if (state != VB2_BUF_STATE_QUEUED)
1150                 __vb2_buf_mem_finish(vb);
1151
1152         spin_lock_irqsave(&q->done_lock, flags);
1153         if (state == VB2_BUF_STATE_QUEUED) {
1154                 vb->state = VB2_BUF_STATE_QUEUED;
1155         } else {
1156                 /* Add the buffer to the done buffers list */
1157                 list_add_tail(&vb->done_entry, &q->done_list);
1158                 vb->state = state;
1159         }
1160         atomic_dec(&q->owned_by_drv_count);
1161
1162         if (state != VB2_BUF_STATE_QUEUED && vb->req_obj.req) {
1163                 media_request_object_unbind(&vb->req_obj);
1164                 media_request_object_put(&vb->req_obj);
1165         }
1166
1167         spin_unlock_irqrestore(&q->done_lock, flags);
1168
1169         trace_vb2_buf_done(q, vb);
1170
1171         switch (state) {
1172         case VB2_BUF_STATE_QUEUED:
1173                 return;
1174         default:
1175                 /* Inform any processes that may be waiting for buffers */
1176                 wake_up(&q->done_wq);
1177                 break;
1178         }
1179 }
1180 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1181
1182 void vb2_discard_done(struct vb2_queue *q)
1183 {
1184         struct vb2_buffer *vb;
1185         unsigned long flags;
1186
1187         spin_lock_irqsave(&q->done_lock, flags);
1188         list_for_each_entry(vb, &q->done_list, done_entry)
1189                 vb->state = VB2_BUF_STATE_ERROR;
1190         spin_unlock_irqrestore(&q->done_lock, flags);
1191 }
1192 EXPORT_SYMBOL_GPL(vb2_discard_done);
1193
1194 /*
1195  * __prepare_mmap() - prepare an MMAP buffer
1196  */
1197 static int __prepare_mmap(struct vb2_buffer *vb)
1198 {
1199         int ret = 0;
1200
1201         ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1202                          vb, vb->planes);
1203         return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
1204 }
1205
1206 /*
1207  * __prepare_userptr() - prepare a USERPTR buffer
1208  */
1209 static int __prepare_userptr(struct vb2_buffer *vb)
1210 {
1211         struct vb2_plane planes[VB2_MAX_PLANES];
1212         struct vb2_queue *q = vb->vb2_queue;
1213         void *mem_priv;
1214         unsigned int plane;
1215         int ret = 0;
1216         bool reacquired = vb->planes[0].mem_priv == NULL;
1217
1218         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1219         /* Copy relevant information provided by the userspace */
1220         ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1221                          vb, planes);
1222         if (ret)
1223                 return ret;
1224
1225         for (plane = 0; plane < vb->num_planes; ++plane) {
1226                 /* Skip the plane if already verified */
1227                 if (vb->planes[plane].m.userptr &&
1228                         vb->planes[plane].m.userptr == planes[plane].m.userptr
1229                         && vb->planes[plane].length == planes[plane].length)
1230                         continue;
1231
1232                 dprintk(q, 3, "userspace address for plane %d changed, reacquiring memory\n",
1233                         plane);
1234
1235                 /* Check if the provided plane buffer is large enough */
1236                 if (planes[plane].length < vb->planes[plane].min_length) {
1237                         dprintk(q, 1, "provided buffer size %u is less than setup size %u for plane %d\n",
1238                                                 planes[plane].length,
1239                                                 vb->planes[plane].min_length,
1240                                                 plane);
1241                         ret = -EINVAL;
1242                         goto err;
1243                 }
1244
1245                 /* Release previously acquired memory if present */
1246                 if (vb->planes[plane].mem_priv) {
1247                         if (!reacquired) {
1248                                 reacquired = true;
1249                                 vb->copied_timestamp = 0;
1250                                 call_void_vb_qop(vb, buf_cleanup, vb);
1251                         }
1252                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1253                 }
1254
1255                 vb->planes[plane].mem_priv = NULL;
1256                 vb->planes[plane].bytesused = 0;
1257                 vb->planes[plane].length = 0;
1258                 vb->planes[plane].m.userptr = 0;
1259                 vb->planes[plane].data_offset = 0;
1260
1261                 /* Acquire each plane's memory */
1262                 mem_priv = call_ptr_memop(get_userptr,
1263                                           vb,
1264                                           q->alloc_devs[plane] ? : q->dev,
1265                                           planes[plane].m.userptr,
1266                                           planes[plane].length);
1267                 if (IS_ERR(mem_priv)) {
1268                         dprintk(q, 1, "failed acquiring userspace memory for plane %d\n",
1269                                 plane);
1270                         ret = PTR_ERR(mem_priv);
1271                         goto err;
1272                 }
1273                 vb->planes[plane].mem_priv = mem_priv;
1274         }
1275
1276         /*
1277          * Now that everything is in order, copy relevant information
1278          * provided by userspace.
1279          */
1280         for (plane = 0; plane < vb->num_planes; ++plane) {
1281                 vb->planes[plane].bytesused = planes[plane].bytesused;
1282                 vb->planes[plane].length = planes[plane].length;
1283                 vb->planes[plane].m.userptr = planes[plane].m.userptr;
1284                 vb->planes[plane].data_offset = planes[plane].data_offset;
1285         }
1286
1287         if (reacquired) {
1288                 /*
1289                  * One or more planes changed, so we must call buf_init to do
1290                  * the driver-specific initialization on the newly acquired
1291                  * buffer, if provided.
1292                  */
1293                 ret = call_vb_qop(vb, buf_init, vb);
1294                 if (ret) {
1295                         dprintk(q, 1, "buffer initialization failed\n");
1296                         goto err;
1297                 }
1298         }
1299
1300         ret = call_vb_qop(vb, buf_prepare, vb);
1301         if (ret) {
1302                 dprintk(q, 1, "buffer preparation failed\n");
1303                 call_void_vb_qop(vb, buf_cleanup, vb);
1304                 goto err;
1305         }
1306
1307         return 0;
1308 err:
1309         /* In case of errors, release planes that were already acquired */
1310         for (plane = 0; plane < vb->num_planes; ++plane) {
1311                 if (vb->planes[plane].mem_priv)
1312                         call_void_memop(vb, put_userptr,
1313                                 vb->planes[plane].mem_priv);
1314                 vb->planes[plane].mem_priv = NULL;
1315                 vb->planes[plane].m.userptr = 0;
1316                 vb->planes[plane].length = 0;
1317         }
1318
1319         return ret;
1320 }
1321
1322 /*
1323  * __prepare_dmabuf() - prepare a DMABUF buffer
1324  */
1325 static int __prepare_dmabuf(struct vb2_buffer *vb)
1326 {
1327         struct vb2_plane planes[VB2_MAX_PLANES];
1328         struct vb2_queue *q = vb->vb2_queue;
1329         void *mem_priv;
1330         unsigned int plane;
1331         int ret = 0;
1332         bool reacquired = vb->planes[0].mem_priv == NULL;
1333
1334         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1335         /* Copy relevant information provided by the userspace */
1336         ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1337                          vb, planes);
1338         if (ret)
1339                 return ret;
1340
1341         for (plane = 0; plane < vb->num_planes; ++plane) {
1342                 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1343
1344                 if (IS_ERR_OR_NULL(dbuf)) {
1345                         dprintk(q, 1, "invalid dmabuf fd for plane %d\n",
1346                                 plane);
1347                         ret = -EINVAL;
1348                         goto err;
1349                 }
1350
1351                 /* use DMABUF size if length is not provided */
1352                 if (planes[plane].length == 0)
1353                         planes[plane].length = dbuf->size;
1354
1355                 if (planes[plane].length < vb->planes[plane].min_length) {
1356                         dprintk(q, 1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
1357                                 planes[plane].length, plane,
1358                                 vb->planes[plane].min_length);
1359                         dma_buf_put(dbuf);
1360                         ret = -EINVAL;
1361                         goto err;
1362                 }
1363
1364                 /* Skip the plane if already verified */
1365                 if (dbuf == vb->planes[plane].dbuf &&
1366                         vb->planes[plane].length == planes[plane].length) {
1367                         dma_buf_put(dbuf);
1368                         continue;
1369                 }
1370
1371                 dprintk(q, 3, "buffer for plane %d changed\n", plane);
1372
1373                 if (!reacquired) {
1374                         reacquired = true;
1375                         vb->copied_timestamp = 0;
1376                         call_void_vb_qop(vb, buf_cleanup, vb);
1377                 }
1378
1379                 /* Release previously acquired memory if present */
1380                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1381                 vb->planes[plane].bytesused = 0;
1382                 vb->planes[plane].length = 0;
1383                 vb->planes[plane].m.fd = 0;
1384                 vb->planes[plane].data_offset = 0;
1385
1386                 /* Acquire each plane's memory */
1387                 mem_priv = call_ptr_memop(attach_dmabuf,
1388                                           vb,
1389                                           q->alloc_devs[plane] ? : q->dev,
1390                                           dbuf,
1391                                           planes[plane].length);
1392                 if (IS_ERR(mem_priv)) {
1393                         dprintk(q, 1, "failed to attach dmabuf\n");
1394                         ret = PTR_ERR(mem_priv);
1395                         dma_buf_put(dbuf);
1396                         goto err;
1397                 }
1398
1399                 vb->planes[plane].dbuf = dbuf;
1400                 vb->planes[plane].mem_priv = mem_priv;
1401         }
1402
1403         /*
1404          * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1405          * here instead just before the DMA, while queueing the buffer(s) so
1406          * userspace knows sooner rather than later if the dma-buf map fails.
1407          */
1408         for (plane = 0; plane < vb->num_planes; ++plane) {
1409                 if (vb->planes[plane].dbuf_mapped)
1410                         continue;
1411
1412                 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1413                 if (ret) {
1414                         dprintk(q, 1, "failed to map dmabuf for plane %d\n",
1415                                 plane);
1416                         goto err;
1417                 }
1418                 vb->planes[plane].dbuf_mapped = 1;
1419         }
1420
1421         /*
1422          * Now that everything is in order, copy relevant information
1423          * provided by userspace.
1424          */
1425         for (plane = 0; plane < vb->num_planes; ++plane) {
1426                 vb->planes[plane].bytesused = planes[plane].bytesused;
1427                 vb->planes[plane].length = planes[plane].length;
1428                 vb->planes[plane].m.fd = planes[plane].m.fd;
1429                 vb->planes[plane].data_offset = planes[plane].data_offset;
1430         }
1431
1432         if (reacquired) {
1433                 /*
1434                  * Call driver-specific initialization on the newly acquired buffer,
1435                  * if provided.
1436                  */
1437                 ret = call_vb_qop(vb, buf_init, vb);
1438                 if (ret) {
1439                         dprintk(q, 1, "buffer initialization failed\n");
1440                         goto err;
1441                 }
1442         }
1443
1444         ret = call_vb_qop(vb, buf_prepare, vb);
1445         if (ret) {
1446                 dprintk(q, 1, "buffer preparation failed\n");
1447                 call_void_vb_qop(vb, buf_cleanup, vb);
1448                 goto err;
1449         }
1450
1451         return 0;
1452 err:
1453         /* In case of errors, release planes that were already acquired */
1454         __vb2_buf_dmabuf_put(vb);
1455
1456         return ret;
1457 }
1458
1459 /*
1460  * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1461  */
1462 static void __enqueue_in_driver(struct vb2_buffer *vb)
1463 {
1464         struct vb2_queue *q = vb->vb2_queue;
1465
1466         vb->state = VB2_BUF_STATE_ACTIVE;
1467         atomic_inc(&q->owned_by_drv_count);
1468
1469         trace_vb2_buf_queue(q, vb);
1470
1471         call_void_vb_qop(vb, buf_queue, vb);
1472 }
1473
1474 static int __buf_prepare(struct vb2_buffer *vb)
1475 {
1476         struct vb2_queue *q = vb->vb2_queue;
1477         enum vb2_buffer_state orig_state = vb->state;
1478         int ret;
1479
1480         if (q->error) {
1481                 dprintk(q, 1, "fatal error occurred on queue\n");
1482                 return -EIO;
1483         }
1484
1485         if (vb->prepared)
1486                 return 0;
1487         WARN_ON(vb->synced);
1488
1489         if (q->is_output) {
1490                 ret = call_vb_qop(vb, buf_out_validate, vb);
1491                 if (ret) {
1492                         dprintk(q, 1, "buffer validation failed\n");
1493                         return ret;
1494                 }
1495         }
1496
1497         vb->state = VB2_BUF_STATE_PREPARING;
1498
1499         switch (q->memory) {
1500         case VB2_MEMORY_MMAP:
1501                 ret = __prepare_mmap(vb);
1502                 break;
1503         case VB2_MEMORY_USERPTR:
1504                 ret = __prepare_userptr(vb);
1505                 break;
1506         case VB2_MEMORY_DMABUF:
1507                 ret = __prepare_dmabuf(vb);
1508                 break;
1509         default:
1510                 WARN(1, "Invalid queue type\n");
1511                 ret = -EINVAL;
1512                 break;
1513         }
1514
1515         if (ret) {
1516                 dprintk(q, 1, "buffer preparation failed: %d\n", ret);
1517                 vb->state = orig_state;
1518                 return ret;
1519         }
1520
1521         __vb2_buf_mem_prepare(vb);
1522         vb->prepared = 1;
1523         vb->state = orig_state;
1524
1525         return 0;
1526 }
1527
1528 static int vb2_req_prepare(struct media_request_object *obj)
1529 {
1530         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1531         int ret;
1532
1533         if (WARN_ON(vb->state != VB2_BUF_STATE_IN_REQUEST))
1534                 return -EINVAL;
1535
1536         mutex_lock(vb->vb2_queue->lock);
1537         ret = __buf_prepare(vb);
1538         mutex_unlock(vb->vb2_queue->lock);
1539         return ret;
1540 }
1541
1542 static void __vb2_dqbuf(struct vb2_buffer *vb);
1543
1544 static void vb2_req_unprepare(struct media_request_object *obj)
1545 {
1546         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1547
1548         mutex_lock(vb->vb2_queue->lock);
1549         __vb2_dqbuf(vb);
1550         vb->state = VB2_BUF_STATE_IN_REQUEST;
1551         mutex_unlock(vb->vb2_queue->lock);
1552         WARN_ON(!vb->req_obj.req);
1553 }
1554
1555 static void vb2_req_queue(struct media_request_object *obj)
1556 {
1557         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1558         int err;
1559
1560         mutex_lock(vb->vb2_queue->lock);
1561         /*
1562          * There is no method to propagate an error from vb2_core_qbuf(),
1563          * so if this returns a non-0 value, then WARN.
1564          *
1565          * The only exception is -EIO which is returned if q->error is
1566          * set. We just ignore that, and expect this will be caught the
1567          * next time vb2_req_prepare() is called.
1568          */
1569         err = vb2_core_qbuf(vb->vb2_queue, vb, NULL, NULL);
1570         WARN_ON_ONCE(err && err != -EIO);
1571         mutex_unlock(vb->vb2_queue->lock);
1572 }
1573
1574 static void vb2_req_unbind(struct media_request_object *obj)
1575 {
1576         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1577
1578         if (vb->state == VB2_BUF_STATE_IN_REQUEST)
1579                 call_void_bufop(vb->vb2_queue, init_buffer, vb);
1580 }
1581
1582 static void vb2_req_release(struct media_request_object *obj)
1583 {
1584         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1585
1586         if (vb->state == VB2_BUF_STATE_IN_REQUEST) {
1587                 vb->state = VB2_BUF_STATE_DEQUEUED;
1588                 if (vb->request)
1589                         media_request_put(vb->request);
1590                 vb->request = NULL;
1591         }
1592 }
1593
1594 static const struct media_request_object_ops vb2_core_req_ops = {
1595         .prepare = vb2_req_prepare,
1596         .unprepare = vb2_req_unprepare,
1597         .queue = vb2_req_queue,
1598         .unbind = vb2_req_unbind,
1599         .release = vb2_req_release,
1600 };
1601
1602 bool vb2_request_object_is_buffer(struct media_request_object *obj)
1603 {
1604         return obj->ops == &vb2_core_req_ops;
1605 }
1606 EXPORT_SYMBOL_GPL(vb2_request_object_is_buffer);
1607
1608 unsigned int vb2_request_buffer_cnt(struct media_request *req)
1609 {
1610         struct media_request_object *obj;
1611         unsigned long flags;
1612         unsigned int buffer_cnt = 0;
1613
1614         spin_lock_irqsave(&req->lock, flags);
1615         list_for_each_entry(obj, &req->objects, list)
1616                 if (vb2_request_object_is_buffer(obj))
1617                         buffer_cnt++;
1618         spin_unlock_irqrestore(&req->lock, flags);
1619
1620         return buffer_cnt;
1621 }
1622 EXPORT_SYMBOL_GPL(vb2_request_buffer_cnt);
1623
1624 int vb2_core_prepare_buf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb)
1625 {
1626         int ret;
1627
1628         if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1629                 dprintk(q, 1, "invalid buffer state %s\n",
1630                         vb2_state_name(vb->state));
1631                 return -EINVAL;
1632         }
1633         if (vb->prepared) {
1634                 dprintk(q, 1, "buffer already prepared\n");
1635                 return -EINVAL;
1636         }
1637
1638         ret = __buf_prepare(vb);
1639         if (ret)
1640                 return ret;
1641
1642         /* Fill buffer information for the userspace */
1643         call_void_bufop(q, fill_user_buffer, vb, pb);
1644
1645         dprintk(q, 2, "prepare of buffer %d succeeded\n", vb->index);
1646
1647         return 0;
1648 }
1649 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1650
1651 /*
1652  * vb2_start_streaming() - Attempt to start streaming.
1653  * @q:          videobuf2 queue
1654  *
1655  * Attempt to start streaming. When this function is called there must be
1656  * at least q->min_queued_buffers queued up (i.e. the minimum
1657  * number of buffers required for the DMA engine to function). If the
1658  * @start_streaming op fails it is supposed to return all the driver-owned
1659  * buffers back to vb2 in state QUEUED. Check if that happened and if
1660  * not warn and reclaim them forcefully.
1661  */
1662 static int vb2_start_streaming(struct vb2_queue *q)
1663 {
1664         struct vb2_buffer *vb;
1665         int ret;
1666
1667         /*
1668          * If any buffers were queued before streamon,
1669          * we can now pass them to driver for processing.
1670          */
1671         list_for_each_entry(vb, &q->queued_list, queued_entry)
1672                 __enqueue_in_driver(vb);
1673
1674         /* Tell the driver to start streaming */
1675         q->start_streaming_called = 1;
1676         ret = call_qop(q, start_streaming, q,
1677                        atomic_read(&q->owned_by_drv_count));
1678         if (!ret)
1679                 return 0;
1680
1681         q->start_streaming_called = 0;
1682
1683         dprintk(q, 1, "driver refused to start streaming\n");
1684         /*
1685          * If you see this warning, then the driver isn't cleaning up properly
1686          * after a failed start_streaming(). See the start_streaming()
1687          * documentation in videobuf2-core.h for more information how buffers
1688          * should be returned to vb2 in start_streaming().
1689          */
1690         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1691                 unsigned i;
1692
1693                 /*
1694                  * Forcefully reclaim buffers if the driver did not
1695                  * correctly return them to vb2.
1696                  */
1697                 for (i = 0; i < vb2_get_num_buffers(q); ++i) {
1698                         vb = vb2_get_buffer(q, i);
1699
1700                         if (!vb)
1701                                 continue;
1702
1703                         if (vb->state == VB2_BUF_STATE_ACTIVE)
1704                                 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1705                 }
1706                 /* Must be zero now */
1707                 WARN_ON(atomic_read(&q->owned_by_drv_count));
1708         }
1709         /*
1710          * If done_list is not empty, then start_streaming() didn't call
1711          * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1712          * STATE_DONE.
1713          */
1714         WARN_ON(!list_empty(&q->done_list));
1715         return ret;
1716 }
1717
1718 int vb2_core_qbuf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb,
1719                   struct media_request *req)
1720 {
1721         enum vb2_buffer_state orig_state;
1722         int ret;
1723
1724         if (q->error) {
1725                 dprintk(q, 1, "fatal error occurred on queue\n");
1726                 return -EIO;
1727         }
1728
1729         if (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1730             q->requires_requests) {
1731                 dprintk(q, 1, "qbuf requires a request\n");
1732                 return -EBADR;
1733         }
1734
1735         if ((req && q->uses_qbuf) ||
1736             (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1737              q->uses_requests)) {
1738                 dprintk(q, 1, "queue in wrong mode (qbuf vs requests)\n");
1739                 return -EBUSY;
1740         }
1741
1742         if (req) {
1743                 int ret;
1744
1745                 q->uses_requests = 1;
1746                 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1747                         dprintk(q, 1, "buffer %d not in dequeued state\n",
1748                                 vb->index);
1749                         return -EINVAL;
1750                 }
1751
1752                 if (q->is_output && !vb->prepared) {
1753                         ret = call_vb_qop(vb, buf_out_validate, vb);
1754                         if (ret) {
1755                                 dprintk(q, 1, "buffer validation failed\n");
1756                                 return ret;
1757                         }
1758                 }
1759
1760                 media_request_object_init(&vb->req_obj);
1761
1762                 /* Make sure the request is in a safe state for updating. */
1763                 ret = media_request_lock_for_update(req);
1764                 if (ret)
1765                         return ret;
1766                 ret = media_request_object_bind(req, &vb2_core_req_ops,
1767                                                 q, true, &vb->req_obj);
1768                 media_request_unlock_for_update(req);
1769                 if (ret)
1770                         return ret;
1771
1772                 vb->state = VB2_BUF_STATE_IN_REQUEST;
1773
1774                 /*
1775                  * Increment the refcount and store the request.
1776                  * The request refcount is decremented again when the
1777                  * buffer is dequeued. This is to prevent vb2_buffer_done()
1778                  * from freeing the request from interrupt context, which can
1779                  * happen if the application closed the request fd after
1780                  * queueing the request.
1781                  */
1782                 media_request_get(req);
1783                 vb->request = req;
1784
1785                 /* Fill buffer information for the userspace */
1786                 if (pb) {
1787                         call_void_bufop(q, copy_timestamp, vb, pb);
1788                         call_void_bufop(q, fill_user_buffer, vb, pb);
1789                 }
1790
1791                 dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
1792                 return 0;
1793         }
1794
1795         if (vb->state != VB2_BUF_STATE_IN_REQUEST)
1796                 q->uses_qbuf = 1;
1797
1798         switch (vb->state) {
1799         case VB2_BUF_STATE_DEQUEUED:
1800         case VB2_BUF_STATE_IN_REQUEST:
1801                 if (!vb->prepared) {
1802                         ret = __buf_prepare(vb);
1803                         if (ret)
1804                                 return ret;
1805                 }
1806                 break;
1807         case VB2_BUF_STATE_PREPARING:
1808                 dprintk(q, 1, "buffer still being prepared\n");
1809                 return -EINVAL;
1810         default:
1811                 dprintk(q, 1, "invalid buffer state %s\n",
1812                         vb2_state_name(vb->state));
1813                 return -EINVAL;
1814         }
1815
1816         /*
1817          * Add to the queued buffers list, a buffer will stay on it until
1818          * dequeued in dqbuf.
1819          */
1820         orig_state = vb->state;
1821         list_add_tail(&vb->queued_entry, &q->queued_list);
1822         q->queued_count++;
1823         q->waiting_for_buffers = false;
1824         vb->state = VB2_BUF_STATE_QUEUED;
1825
1826         if (pb)
1827                 call_void_bufop(q, copy_timestamp, vb, pb);
1828
1829         trace_vb2_qbuf(q, vb);
1830
1831         /*
1832          * If already streaming, give the buffer to driver for processing.
1833          * If not, the buffer will be given to driver on next streamon.
1834          */
1835         if (q->start_streaming_called)
1836                 __enqueue_in_driver(vb);
1837
1838         /* Fill buffer information for the userspace */
1839         if (pb)
1840                 call_void_bufop(q, fill_user_buffer, vb, pb);
1841
1842         /*
1843          * If streamon has been called, and we haven't yet called
1844          * start_streaming() since not enough buffers were queued, and
1845          * we now have reached the minimum number of queued buffers,
1846          * then we can finally call start_streaming().
1847          */
1848         if (q->streaming && !q->start_streaming_called &&
1849             q->queued_count >= q->min_queued_buffers) {
1850                 ret = vb2_start_streaming(q);
1851                 if (ret) {
1852                         /*
1853                          * Since vb2_core_qbuf will return with an error,
1854                          * we should return it to state DEQUEUED since
1855                          * the error indicates that the buffer wasn't queued.
1856                          */
1857                         list_del(&vb->queued_entry);
1858                         q->queued_count--;
1859                         vb->state = orig_state;
1860                         return ret;
1861                 }
1862         }
1863
1864         dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
1865         return 0;
1866 }
1867 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1868
1869 /*
1870  * __vb2_wait_for_done_vb() - wait for a buffer to become available
1871  * for dequeuing
1872  *
1873  * Will sleep if required for nonblocking == false.
1874  */
1875 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1876 {
1877         /*
1878          * All operations on vb_done_list are performed under done_lock
1879          * spinlock protection. However, buffers may be removed from
1880          * it and returned to userspace only while holding both driver's
1881          * lock and the done_lock spinlock. Thus we can be sure that as
1882          * long as we hold the driver's lock, the list will remain not
1883          * empty if list_empty() check succeeds.
1884          */
1885
1886         for (;;) {
1887                 int ret;
1888
1889                 if (q->waiting_in_dqbuf) {
1890                         dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
1891                         return -EBUSY;
1892                 }
1893
1894                 if (!q->streaming) {
1895                         dprintk(q, 1, "streaming off, will not wait for buffers\n");
1896                         return -EINVAL;
1897                 }
1898
1899                 if (q->error) {
1900                         dprintk(q, 1, "Queue in error state, will not wait for buffers\n");
1901                         return -EIO;
1902                 }
1903
1904                 if (q->last_buffer_dequeued) {
1905                         dprintk(q, 3, "last buffer dequeued already, will not wait for buffers\n");
1906                         return -EPIPE;
1907                 }
1908
1909                 if (!list_empty(&q->done_list)) {
1910                         /*
1911                          * Found a buffer that we were waiting for.
1912                          */
1913                         break;
1914                 }
1915
1916                 if (nonblocking) {
1917                         dprintk(q, 3, "nonblocking and no buffers to dequeue, will not wait\n");
1918                         return -EAGAIN;
1919                 }
1920
1921                 q->waiting_in_dqbuf = 1;
1922                 /*
1923                  * We are streaming and blocking, wait for another buffer to
1924                  * become ready or for streamoff. Driver's lock is released to
1925                  * allow streamoff or qbuf to be called while waiting.
1926                  */
1927                 call_void_qop(q, wait_prepare, q);
1928
1929                 /*
1930                  * All locks have been released, it is safe to sleep now.
1931                  */
1932                 dprintk(q, 3, "will sleep waiting for buffers\n");
1933                 ret = wait_event_interruptible(q->done_wq,
1934                                 !list_empty(&q->done_list) || !q->streaming ||
1935                                 q->error);
1936
1937                 /*
1938                  * We need to reevaluate both conditions again after reacquiring
1939                  * the locks or return an error if one occurred.
1940                  */
1941                 call_void_qop(q, wait_finish, q);
1942                 q->waiting_in_dqbuf = 0;
1943                 if (ret) {
1944                         dprintk(q, 1, "sleep was interrupted\n");
1945                         return ret;
1946                 }
1947         }
1948         return 0;
1949 }
1950
1951 /*
1952  * __vb2_get_done_vb() - get a buffer ready for dequeuing
1953  *
1954  * Will sleep if required for nonblocking == false.
1955  */
1956 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1957                              void *pb, int nonblocking)
1958 {
1959         unsigned long flags;
1960         int ret = 0;
1961
1962         /*
1963          * Wait for at least one buffer to become available on the done_list.
1964          */
1965         ret = __vb2_wait_for_done_vb(q, nonblocking);
1966         if (ret)
1967                 return ret;
1968
1969         /*
1970          * Driver's lock has been held since we last verified that done_list
1971          * is not empty, so no need for another list_empty(done_list) check.
1972          */
1973         spin_lock_irqsave(&q->done_lock, flags);
1974         *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1975         /*
1976          * Only remove the buffer from done_list if all planes can be
1977          * handled. Some cases such as V4L2 file I/O and DVB have pb
1978          * == NULL; skip the check then as there's nothing to verify.
1979          */
1980         if (pb)
1981                 ret = call_bufop(q, verify_planes_array, *vb, pb);
1982         if (!ret)
1983                 list_del(&(*vb)->done_entry);
1984         spin_unlock_irqrestore(&q->done_lock, flags);
1985
1986         return ret;
1987 }
1988
1989 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1990 {
1991         if (!q->streaming) {
1992                 dprintk(q, 1, "streaming off, will not wait for buffers\n");
1993                 return -EINVAL;
1994         }
1995
1996         if (q->start_streaming_called)
1997                 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1998         return 0;
1999 }
2000 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
2001
2002 /*
2003  * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
2004  */
2005 static void __vb2_dqbuf(struct vb2_buffer *vb)
2006 {
2007         struct vb2_queue *q = vb->vb2_queue;
2008
2009         /* nothing to do if the buffer is already dequeued */
2010         if (vb->state == VB2_BUF_STATE_DEQUEUED)
2011                 return;
2012
2013         vb->state = VB2_BUF_STATE_DEQUEUED;
2014
2015         call_void_bufop(q, init_buffer, vb);
2016 }
2017
2018 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
2019                    bool nonblocking)
2020 {
2021         struct vb2_buffer *vb = NULL;
2022         int ret;
2023
2024         ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
2025         if (ret < 0)
2026                 return ret;
2027
2028         switch (vb->state) {
2029         case VB2_BUF_STATE_DONE:
2030                 dprintk(q, 3, "returning done buffer\n");
2031                 break;
2032         case VB2_BUF_STATE_ERROR:
2033                 dprintk(q, 3, "returning done buffer with errors\n");
2034                 break;
2035         default:
2036                 dprintk(q, 1, "invalid buffer state %s\n",
2037                         vb2_state_name(vb->state));
2038                 return -EINVAL;
2039         }
2040
2041         call_void_vb_qop(vb, buf_finish, vb);
2042         vb->prepared = 0;
2043
2044         if (pindex)
2045                 *pindex = vb->index;
2046
2047         /* Fill buffer information for the userspace */
2048         if (pb)
2049                 call_void_bufop(q, fill_user_buffer, vb, pb);
2050
2051         /* Remove from vb2 queue */
2052         list_del(&vb->queued_entry);
2053         q->queued_count--;
2054
2055         trace_vb2_dqbuf(q, vb);
2056
2057         /* go back to dequeued state */
2058         __vb2_dqbuf(vb);
2059
2060         if (WARN_ON(vb->req_obj.req)) {
2061                 media_request_object_unbind(&vb->req_obj);
2062                 media_request_object_put(&vb->req_obj);
2063         }
2064         if (vb->request)
2065                 media_request_put(vb->request);
2066         vb->request = NULL;
2067
2068         dprintk(q, 2, "dqbuf of buffer %d, state: %s\n",
2069                 vb->index, vb2_state_name(vb->state));
2070
2071         return 0;
2072
2073 }
2074 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
2075
2076 /*
2077  * __vb2_queue_cancel() - cancel and stop (pause) streaming
2078  *
2079  * Removes all queued buffers from driver's queue and all buffers queued by
2080  * userspace from vb2's queue. Returns to state after reqbufs.
2081  */
2082 static void __vb2_queue_cancel(struct vb2_queue *q)
2083 {
2084         unsigned int i;
2085
2086         /*
2087          * Tell driver to stop all transactions and release all queued
2088          * buffers.
2089          */
2090         if (q->start_streaming_called)
2091                 call_void_qop(q, stop_streaming, q);
2092
2093         if (q->streaming)
2094                 call_void_qop(q, unprepare_streaming, q);
2095
2096         /*
2097          * If you see this warning, then the driver isn't cleaning up properly
2098          * in stop_streaming(). See the stop_streaming() documentation in
2099          * videobuf2-core.h for more information how buffers should be returned
2100          * to vb2 in stop_streaming().
2101          */
2102         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
2103                 for (i = 0; i < vb2_get_num_buffers(q); i++) {
2104                         struct vb2_buffer *vb = vb2_get_buffer(q, i);
2105
2106                         if (!vb)
2107                                 continue;
2108
2109                         if (vb->state == VB2_BUF_STATE_ACTIVE) {
2110                                 pr_warn("driver bug: stop_streaming operation is leaving buffer %u in active state\n",
2111                                         vb->index);
2112                                 vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
2113                         }
2114                 }
2115                 /* Must be zero now */
2116                 WARN_ON(atomic_read(&q->owned_by_drv_count));
2117         }
2118
2119         q->streaming = 0;
2120         q->start_streaming_called = 0;
2121         q->queued_count = 0;
2122         q->error = 0;
2123         q->uses_requests = 0;
2124         q->uses_qbuf = 0;
2125
2126         /*
2127          * Remove all buffers from vb2's list...
2128          */
2129         INIT_LIST_HEAD(&q->queued_list);
2130         /*
2131          * ...and done list; userspace will not receive any buffers it
2132          * has not already dequeued before initiating cancel.
2133          */
2134         INIT_LIST_HEAD(&q->done_list);
2135         atomic_set(&q->owned_by_drv_count, 0);
2136         wake_up_all(&q->done_wq);
2137
2138         /*
2139          * Reinitialize all buffers for next use.
2140          * Make sure to call buf_finish for any queued buffers. Normally
2141          * that's done in dqbuf, but that's not going to happen when we
2142          * cancel the whole queue. Note: this code belongs here, not in
2143          * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
2144          * call to __fill_user_buffer() after buf_finish(). That order can't
2145          * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2146          */
2147         for (i = 0; i < vb2_get_num_buffers(q); i++) {
2148                 struct vb2_buffer *vb;
2149                 struct media_request *req;
2150
2151                 vb = vb2_get_buffer(q, i);
2152                 if (!vb)
2153                         continue;
2154
2155                 req = vb->req_obj.req;
2156                 /*
2157                  * If a request is associated with this buffer, then
2158                  * call buf_request_cancel() to give the driver to complete()
2159                  * related request objects. Otherwise those objects would
2160                  * never complete.
2161                  */
2162                 if (req) {
2163                         enum media_request_state state;
2164                         unsigned long flags;
2165
2166                         spin_lock_irqsave(&req->lock, flags);
2167                         state = req->state;
2168                         spin_unlock_irqrestore(&req->lock, flags);
2169
2170                         if (state == MEDIA_REQUEST_STATE_QUEUED)
2171                                 call_void_vb_qop(vb, buf_request_complete, vb);
2172                 }
2173
2174                 __vb2_buf_mem_finish(vb);
2175
2176                 if (vb->prepared) {
2177                         call_void_vb_qop(vb, buf_finish, vb);
2178                         vb->prepared = 0;
2179                 }
2180                 __vb2_dqbuf(vb);
2181
2182                 if (vb->req_obj.req) {
2183                         media_request_object_unbind(&vb->req_obj);
2184                         media_request_object_put(&vb->req_obj);
2185                 }
2186                 if (vb->request)
2187                         media_request_put(vb->request);
2188                 vb->request = NULL;
2189                 vb->copied_timestamp = 0;
2190         }
2191 }
2192
2193 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
2194 {
2195         unsigned int q_num_bufs = vb2_get_num_buffers(q);
2196         int ret;
2197
2198         if (type != q->type) {
2199                 dprintk(q, 1, "invalid stream type\n");
2200                 return -EINVAL;
2201         }
2202
2203         if (q->streaming) {
2204                 dprintk(q, 3, "already streaming\n");
2205                 return 0;
2206         }
2207
2208         if (!q_num_bufs) {
2209                 dprintk(q, 1, "no buffers have been allocated\n");
2210                 return -EINVAL;
2211         }
2212
2213         if (q_num_bufs < q->min_queued_buffers) {
2214                 dprintk(q, 1, "need at least %u queued buffers\n",
2215                         q->min_queued_buffers);
2216                 return -EINVAL;
2217         }
2218
2219         ret = call_qop(q, prepare_streaming, q);
2220         if (ret)
2221                 return ret;
2222
2223         /*
2224          * Tell driver to start streaming provided sufficient buffers
2225          * are available.
2226          */
2227         if (q->queued_count >= q->min_queued_buffers) {
2228                 ret = vb2_start_streaming(q);
2229                 if (ret)
2230                         goto unprepare;
2231         }
2232
2233         q->streaming = 1;
2234
2235         dprintk(q, 3, "successful\n");
2236         return 0;
2237
2238 unprepare:
2239         call_void_qop(q, unprepare_streaming, q);
2240         return ret;
2241 }
2242 EXPORT_SYMBOL_GPL(vb2_core_streamon);
2243
2244 void vb2_queue_error(struct vb2_queue *q)
2245 {
2246         q->error = 1;
2247
2248         wake_up_all(&q->done_wq);
2249 }
2250 EXPORT_SYMBOL_GPL(vb2_queue_error);
2251
2252 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
2253 {
2254         if (type != q->type) {
2255                 dprintk(q, 1, "invalid stream type\n");
2256                 return -EINVAL;
2257         }
2258
2259         /*
2260          * Cancel will pause streaming and remove all buffers from the driver
2261          * and vb2, effectively returning control over them to userspace.
2262          *
2263          * Note that we do this even if q->streaming == 0: if you prepare or
2264          * queue buffers, and then call streamoff without ever having called
2265          * streamon, you would still expect those buffers to be returned to
2266          * their normal dequeued state.
2267          */
2268         __vb2_queue_cancel(q);
2269         q->waiting_for_buffers = !q->is_output;
2270         q->last_buffer_dequeued = false;
2271
2272         dprintk(q, 3, "successful\n");
2273         return 0;
2274 }
2275 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
2276
2277 /*
2278  * __find_plane_by_offset() - find plane associated with the given offset
2279  */
2280 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long offset,
2281                         struct vb2_buffer **vb, unsigned int *plane)
2282 {
2283         unsigned int buffer;
2284
2285         /*
2286          * Sanity checks to ensure the lock is held, MEMORY_MMAP is
2287          * used and fileio isn't active.
2288          */
2289         lockdep_assert_held(&q->mmap_lock);
2290
2291         if (q->memory != VB2_MEMORY_MMAP) {
2292                 dprintk(q, 1, "queue is not currently set up for mmap\n");
2293                 return -EINVAL;
2294         }
2295
2296         if (vb2_fileio_is_active(q)) {
2297                 dprintk(q, 1, "file io in progress\n");
2298                 return -EBUSY;
2299         }
2300
2301         /* Get buffer and plane from the offset */
2302         buffer = (offset >> PLANE_INDEX_SHIFT) & BUFFER_INDEX_MASK;
2303         *plane = (offset >> PAGE_SHIFT) & PLANE_INDEX_MASK;
2304
2305         *vb = vb2_get_buffer(q, buffer);
2306         if (!*vb)
2307                 return -EINVAL;
2308         if (*plane >= (*vb)->num_planes)
2309                 return -EINVAL;
2310
2311         return 0;
2312 }
2313
2314 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
2315                     struct vb2_buffer *vb, unsigned int plane, unsigned int flags)
2316 {
2317         struct vb2_plane *vb_plane;
2318         int ret;
2319         struct dma_buf *dbuf;
2320
2321         if (q->memory != VB2_MEMORY_MMAP) {
2322                 dprintk(q, 1, "queue is not currently set up for mmap\n");
2323                 return -EINVAL;
2324         }
2325
2326         if (!q->mem_ops->get_dmabuf) {
2327                 dprintk(q, 1, "queue does not support DMA buffer exporting\n");
2328                 return -EINVAL;
2329         }
2330
2331         if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
2332                 dprintk(q, 1, "queue does support only O_CLOEXEC and access mode flags\n");
2333                 return -EINVAL;
2334         }
2335
2336         if (type != q->type) {
2337                 dprintk(q, 1, "invalid buffer type\n");
2338                 return -EINVAL;
2339         }
2340
2341         if (plane >= vb->num_planes) {
2342                 dprintk(q, 1, "buffer plane out of range\n");
2343                 return -EINVAL;
2344         }
2345
2346         if (vb2_fileio_is_active(q)) {
2347                 dprintk(q, 1, "expbuf: file io in progress\n");
2348                 return -EBUSY;
2349         }
2350
2351         vb_plane = &vb->planes[plane];
2352
2353         dbuf = call_ptr_memop(get_dmabuf,
2354                               vb,
2355                               vb_plane->mem_priv,
2356                               flags & O_ACCMODE);
2357         if (IS_ERR_OR_NULL(dbuf)) {
2358                 dprintk(q, 1, "failed to export buffer %d, plane %d\n",
2359                         vb->index, plane);
2360                 return -EINVAL;
2361         }
2362
2363         ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
2364         if (ret < 0) {
2365                 dprintk(q, 3, "buffer %d, plane %d failed to export (%d)\n",
2366                         vb->index, plane, ret);
2367                 dma_buf_put(dbuf);
2368                 return ret;
2369         }
2370
2371         dprintk(q, 3, "buffer %d, plane %d exported as %d descriptor\n",
2372                 vb->index, plane, ret);
2373         *fd = ret;
2374
2375         return 0;
2376 }
2377 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
2378
2379 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2380 {
2381         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
2382         struct vb2_buffer *vb;
2383         unsigned int plane = 0;
2384         int ret;
2385         unsigned long length;
2386
2387         /*
2388          * Check memory area access mode.
2389          */
2390         if (!(vma->vm_flags & VM_SHARED)) {
2391                 dprintk(q, 1, "invalid vma flags, VM_SHARED needed\n");
2392                 return -EINVAL;
2393         }
2394         if (q->is_output) {
2395                 if (!(vma->vm_flags & VM_WRITE)) {
2396                         dprintk(q, 1, "invalid vma flags, VM_WRITE needed\n");
2397                         return -EINVAL;
2398                 }
2399         } else {
2400                 if (!(vma->vm_flags & VM_READ)) {
2401                         dprintk(q, 1, "invalid vma flags, VM_READ needed\n");
2402                         return -EINVAL;
2403                 }
2404         }
2405
2406         mutex_lock(&q->mmap_lock);
2407
2408         /*
2409          * Find the plane corresponding to the offset passed by userspace. This
2410          * will return an error if not MEMORY_MMAP or file I/O is in progress.
2411          */
2412         ret = __find_plane_by_offset(q, offset, &vb, &plane);
2413         if (ret)
2414                 goto unlock;
2415
2416         /*
2417          * MMAP requires page_aligned buffers.
2418          * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2419          * so, we need to do the same here.
2420          */
2421         length = PAGE_ALIGN(vb->planes[plane].length);
2422         if (length < (vma->vm_end - vma->vm_start)) {
2423                 dprintk(q, 1,
2424                         "MMAP invalid, as it would overflow buffer length\n");
2425                 ret = -EINVAL;
2426                 goto unlock;
2427         }
2428
2429         /*
2430          * vm_pgoff is treated in V4L2 API as a 'cookie' to select a buffer,
2431          * not as a in-buffer offset. We always want to mmap a whole buffer
2432          * from its beginning.
2433          */
2434         vma->vm_pgoff = 0;
2435
2436         ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2437
2438 unlock:
2439         mutex_unlock(&q->mmap_lock);
2440         if (ret)
2441                 return ret;
2442
2443         dprintk(q, 3, "buffer %u, plane %d successfully mapped\n", vb->index, plane);
2444         return 0;
2445 }
2446 EXPORT_SYMBOL_GPL(vb2_mmap);
2447
2448 #ifndef CONFIG_MMU
2449 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2450                                     unsigned long addr,
2451                                     unsigned long len,
2452                                     unsigned long pgoff,
2453                                     unsigned long flags)
2454 {
2455         unsigned long offset = pgoff << PAGE_SHIFT;
2456         struct vb2_buffer *vb;
2457         unsigned int plane;
2458         void *vaddr;
2459         int ret;
2460
2461         mutex_lock(&q->mmap_lock);
2462
2463         /*
2464          * Find the plane corresponding to the offset passed by userspace. This
2465          * will return an error if not MEMORY_MMAP or file I/O is in progress.
2466          */
2467         ret = __find_plane_by_offset(q, offset, &vb, &plane);
2468         if (ret)
2469                 goto unlock;
2470
2471         vaddr = vb2_plane_vaddr(vb, plane);
2472         mutex_unlock(&q->mmap_lock);
2473         return vaddr ? (unsigned long)vaddr : -EINVAL;
2474
2475 unlock:
2476         mutex_unlock(&q->mmap_lock);
2477         return ret;
2478 }
2479 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2480 #endif
2481
2482 int vb2_core_queue_init(struct vb2_queue *q)
2483 {
2484         /*
2485          * Sanity check
2486          */
2487         /*
2488          * For drivers who don't support max_num_buffers ensure
2489          * a backward compatibility.
2490          */
2491         if (!q->max_num_buffers)
2492                 q->max_num_buffers = VB2_MAX_FRAME;
2493
2494         /* The maximum is limited by offset cookie encoding pattern */
2495         q->max_num_buffers = min_t(unsigned int, q->max_num_buffers, MAX_BUFFER_INDEX);
2496
2497         if (WARN_ON(!q)                   ||
2498             WARN_ON(!q->ops)              ||
2499             WARN_ON(!q->mem_ops)          ||
2500             WARN_ON(!q->type)             ||
2501             WARN_ON(!q->io_modes)         ||
2502             WARN_ON(!q->ops->queue_setup) ||
2503             WARN_ON(!q->ops->buf_queue))
2504                 return -EINVAL;
2505
2506         if (WARN_ON(q->max_num_buffers > MAX_BUFFER_INDEX) ||
2507             WARN_ON(q->min_queued_buffers > q->max_num_buffers))
2508                 return -EINVAL;
2509
2510         if (WARN_ON(q->requires_requests && !q->supports_requests))
2511                 return -EINVAL;
2512
2513         /*
2514          * This combination is not allowed since a non-zero value of
2515          * q->min_queued_buffers can cause vb2_core_qbuf() to fail if
2516          * it has to call start_streaming(), and the Request API expects
2517          * that queueing a request (and thus queueing a buffer contained
2518          * in that request) will always succeed. There is no method of
2519          * propagating an error back to userspace.
2520          */
2521         if (WARN_ON(q->supports_requests && q->min_queued_buffers))
2522                 return -EINVAL;
2523
2524         INIT_LIST_HEAD(&q->queued_list);
2525         INIT_LIST_HEAD(&q->done_list);
2526         spin_lock_init(&q->done_lock);
2527         mutex_init(&q->mmap_lock);
2528         init_waitqueue_head(&q->done_wq);
2529
2530         q->memory = VB2_MEMORY_UNKNOWN;
2531
2532         if (q->buf_struct_size == 0)
2533                 q->buf_struct_size = sizeof(struct vb2_buffer);
2534
2535         if (q->bidirectional)
2536                 q->dma_dir = DMA_BIDIRECTIONAL;
2537         else
2538                 q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
2539
2540         if (q->name[0] == '\0')
2541                 snprintf(q->name, sizeof(q->name), "%s-%p",
2542                          q->is_output ? "out" : "cap", q);
2543
2544         return 0;
2545 }
2546 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2547
2548 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2549 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2550 void vb2_core_queue_release(struct vb2_queue *q)
2551 {
2552         __vb2_cleanup_fileio(q);
2553         __vb2_queue_cancel(q);
2554         mutex_lock(&q->mmap_lock);
2555         __vb2_queue_free(q, vb2_get_num_buffers(q));
2556         kfree(q->bufs);
2557         q->bufs = NULL;
2558         mutex_unlock(&q->mmap_lock);
2559 }
2560 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2561
2562 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
2563                 poll_table *wait)
2564 {
2565         __poll_t req_events = poll_requested_events(wait);
2566         struct vb2_buffer *vb = NULL;
2567         unsigned long flags;
2568
2569         /*
2570          * poll_wait() MUST be called on the first invocation on all the
2571          * potential queues of interest, even if we are not interested in their
2572          * events during this first call. Failure to do so will result in
2573          * queue's events to be ignored because the poll_table won't be capable
2574          * of adding new wait queues thereafter.
2575          */
2576         poll_wait(file, &q->done_wq, wait);
2577
2578         if (!q->is_output && !(req_events & (EPOLLIN | EPOLLRDNORM)))
2579                 return 0;
2580         if (q->is_output && !(req_events & (EPOLLOUT | EPOLLWRNORM)))
2581                 return 0;
2582
2583         /*
2584          * Start file I/O emulator only if streaming API has not been used yet.
2585          */
2586         if (vb2_get_num_buffers(q) == 0 && !vb2_fileio_is_active(q)) {
2587                 if (!q->is_output && (q->io_modes & VB2_READ) &&
2588                                 (req_events & (EPOLLIN | EPOLLRDNORM))) {
2589                         if (__vb2_init_fileio(q, 1))
2590                                 return EPOLLERR;
2591                 }
2592                 if (q->is_output && (q->io_modes & VB2_WRITE) &&
2593                                 (req_events & (EPOLLOUT | EPOLLWRNORM))) {
2594                         if (__vb2_init_fileio(q, 0))
2595                                 return EPOLLERR;
2596                         /*
2597                          * Write to OUTPUT queue can be done immediately.
2598                          */
2599                         return EPOLLOUT | EPOLLWRNORM;
2600                 }
2601         }
2602
2603         /*
2604          * There is nothing to wait for if the queue isn't streaming, or if the
2605          * error flag is set.
2606          */
2607         if (!vb2_is_streaming(q) || q->error)
2608                 return EPOLLERR;
2609
2610         /*
2611          * If this quirk is set and QBUF hasn't been called yet then
2612          * return EPOLLERR as well. This only affects capture queues, output
2613          * queues will always initialize waiting_for_buffers to false.
2614          * This quirk is set by V4L2 for backwards compatibility reasons.
2615          */
2616         if (q->quirk_poll_must_check_waiting_for_buffers &&
2617             q->waiting_for_buffers && (req_events & (EPOLLIN | EPOLLRDNORM)))
2618                 return EPOLLERR;
2619
2620         /*
2621          * For output streams you can call write() as long as there are fewer
2622          * buffers queued than there are buffers available.
2623          */
2624         if (q->is_output && q->fileio && q->queued_count < vb2_get_num_buffers(q))
2625                 return EPOLLOUT | EPOLLWRNORM;
2626
2627         if (list_empty(&q->done_list)) {
2628                 /*
2629                  * If the last buffer was dequeued from a capture queue,
2630                  * return immediately. DQBUF will return -EPIPE.
2631                  */
2632                 if (q->last_buffer_dequeued)
2633                         return EPOLLIN | EPOLLRDNORM;
2634         }
2635
2636         /*
2637          * Take first buffer available for dequeuing.
2638          */
2639         spin_lock_irqsave(&q->done_lock, flags);
2640         if (!list_empty(&q->done_list))
2641                 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2642                                         done_entry);
2643         spin_unlock_irqrestore(&q->done_lock, flags);
2644
2645         if (vb && (vb->state == VB2_BUF_STATE_DONE
2646                         || vb->state == VB2_BUF_STATE_ERROR)) {
2647                 return (q->is_output) ?
2648                                 EPOLLOUT | EPOLLWRNORM :
2649                                 EPOLLIN | EPOLLRDNORM;
2650         }
2651         return 0;
2652 }
2653 EXPORT_SYMBOL_GPL(vb2_core_poll);
2654
2655 /*
2656  * struct vb2_fileio_buf - buffer context used by file io emulator
2657  *
2658  * vb2 provides a compatibility layer and emulator of file io (read and
2659  * write) calls on top of streaming API. This structure is used for
2660  * tracking context related to the buffers.
2661  */
2662 struct vb2_fileio_buf {
2663         void *vaddr;
2664         unsigned int size;
2665         unsigned int pos;
2666         unsigned int queued:1;
2667 };
2668
2669 /*
2670  * struct vb2_fileio_data - queue context used by file io emulator
2671  *
2672  * @cur_index:  the index of the buffer currently being read from or
2673  *              written to. If equal to number of buffers in the vb2_queue
2674  *              then a new buffer must be dequeued.
2675  * @initial_index: in the read() case all buffers are queued up immediately
2676  *              in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2677  *              buffers. However, in the write() case no buffers are initially
2678  *              queued, instead whenever a buffer is full it is queued up by
2679  *              __vb2_perform_fileio(). Only once all available buffers have
2680  *              been queued up will __vb2_perform_fileio() start to dequeue
2681  *              buffers. This means that initially __vb2_perform_fileio()
2682  *              needs to know what buffer index to use when it is queuing up
2683  *              the buffers for the first time. That initial index is stored
2684  *              in this field. Once it is equal to number of buffers in the
2685  *              vb2_queue all available buffers have been queued and
2686  *              __vb2_perform_fileio() should start the normal dequeue/queue cycle.
2687  *
2688  * vb2 provides a compatibility layer and emulator of file io (read and
2689  * write) calls on top of streaming API. For proper operation it required
2690  * this structure to save the driver state between each call of the read
2691  * or write function.
2692  */
2693 struct vb2_fileio_data {
2694         unsigned int count;
2695         unsigned int type;
2696         unsigned int memory;
2697         struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2698         unsigned int cur_index;
2699         unsigned int initial_index;
2700         unsigned int q_count;
2701         unsigned int dq_count;
2702         unsigned read_once:1;
2703         unsigned write_immediately:1;
2704 };
2705
2706 /*
2707  * __vb2_init_fileio() - initialize file io emulator
2708  * @q:          videobuf2 queue
2709  * @read:       mode selector (1 means read, 0 means write)
2710  */
2711 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2712 {
2713         struct vb2_fileio_data *fileio;
2714         struct vb2_buffer *vb;
2715         int i, ret;
2716         unsigned int count = 0;
2717
2718         /*
2719          * Sanity check
2720          */
2721         if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2722                     (!read && !(q->io_modes & VB2_WRITE))))
2723                 return -EINVAL;
2724
2725         /*
2726          * Check if device supports mapping buffers to kernel virtual space.
2727          */
2728         if (!q->mem_ops->vaddr)
2729                 return -EBUSY;
2730
2731         /*
2732          * Check if streaming api has not been already activated.
2733          */
2734         if (q->streaming || vb2_get_num_buffers(q) > 0)
2735                 return -EBUSY;
2736
2737         /*
2738          * Start with q->min_queued_buffers + 1, driver can increase it in
2739          * queue_setup()
2740          *
2741          * 'min_queued_buffers' buffers need to be queued up before you
2742          * can start streaming, plus 1 for userspace (or in this case,
2743          * kernelspace) processing.
2744          */
2745         count = max(2, q->min_queued_buffers + 1);
2746
2747         dprintk(q, 3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2748                 (read) ? "read" : "write", count, q->fileio_read_once,
2749                 q->fileio_write_immediately);
2750
2751         fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2752         if (fileio == NULL)
2753                 return -ENOMEM;
2754
2755         fileio->read_once = q->fileio_read_once;
2756         fileio->write_immediately = q->fileio_write_immediately;
2757
2758         /*
2759          * Request buffers and use MMAP type to force driver
2760          * to allocate buffers by itself.
2761          */
2762         fileio->count = count;
2763         fileio->memory = VB2_MEMORY_MMAP;
2764         fileio->type = q->type;
2765         q->fileio = fileio;
2766         ret = vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
2767         if (ret)
2768                 goto err_kfree;
2769
2770         /*
2771          * Userspace can never add or delete buffers later, so there
2772          * will never be holes. It is safe to assume that vb2_get_buffer(q, 0)
2773          * will always return a valid vb pointer
2774          */
2775         vb = vb2_get_buffer(q, 0);
2776
2777         /*
2778          * Check if plane_count is correct
2779          * (multiplane buffers are not supported).
2780          */
2781         if (vb->num_planes != 1) {
2782                 ret = -EBUSY;
2783                 goto err_reqbufs;
2784         }
2785
2786         /*
2787          * Get kernel address of each buffer.
2788          */
2789         for (i = 0; i < vb2_get_num_buffers(q); i++) {
2790                 /* vb can never be NULL when using fileio. */
2791                 vb = vb2_get_buffer(q, i);
2792
2793                 fileio->bufs[i].vaddr = vb2_plane_vaddr(vb, 0);
2794                 if (fileio->bufs[i].vaddr == NULL) {
2795                         ret = -EINVAL;
2796                         goto err_reqbufs;
2797                 }
2798                 fileio->bufs[i].size = vb2_plane_size(vb, 0);
2799         }
2800
2801         /*
2802          * Read mode requires pre queuing of all buffers.
2803          */
2804         if (read) {
2805                 /*
2806                  * Queue all buffers.
2807                  */
2808                 for (i = 0; i < vb2_get_num_buffers(q); i++) {
2809                         struct vb2_buffer *vb2 = vb2_get_buffer(q, i);
2810
2811                         if (!vb2)
2812                                 continue;
2813
2814                         ret = vb2_core_qbuf(q, vb2, NULL, NULL);
2815                         if (ret)
2816                                 goto err_reqbufs;
2817                         fileio->bufs[i].queued = 1;
2818                 }
2819                 /*
2820                  * All buffers have been queued, so mark that by setting
2821                  * initial_index to the number of buffers in the vb2_queue
2822                  */
2823                 fileio->initial_index = vb2_get_num_buffers(q);
2824                 fileio->cur_index = fileio->initial_index;
2825         }
2826
2827         /*
2828          * Start streaming.
2829          */
2830         ret = vb2_core_streamon(q, q->type);
2831         if (ret)
2832                 goto err_reqbufs;
2833
2834         return ret;
2835
2836 err_reqbufs:
2837         fileio->count = 0;
2838         vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
2839
2840 err_kfree:
2841         q->fileio = NULL;
2842         kfree(fileio);
2843         return ret;
2844 }
2845
2846 /*
2847  * __vb2_cleanup_fileio() - free resourced used by file io emulator
2848  * @q:          videobuf2 queue
2849  */
2850 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2851 {
2852         struct vb2_fileio_data *fileio = q->fileio;
2853
2854         if (fileio) {
2855                 vb2_core_streamoff(q, q->type);
2856                 q->fileio = NULL;
2857                 fileio->count = 0;
2858                 vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
2859                 kfree(fileio);
2860                 dprintk(q, 3, "file io emulator closed\n");
2861         }
2862         return 0;
2863 }
2864
2865 /*
2866  * __vb2_perform_fileio() - perform a single file io (read or write) operation
2867  * @q:          videobuf2 queue
2868  * @data:       pointed to target userspace buffer
2869  * @count:      number of bytes to read or write
2870  * @ppos:       file handle position tracking pointer
2871  * @nonblock:   mode selector (1 means blocking calls, 0 means nonblocking)
2872  * @read:       access mode selector (1 means read, 0 means write)
2873  */
2874 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2875                 loff_t *ppos, int nonblock, int read)
2876 {
2877         struct vb2_fileio_data *fileio;
2878         struct vb2_fileio_buf *buf;
2879         bool is_multiplanar = q->is_multiplanar;
2880         /*
2881          * When using write() to write data to an output video node the vb2 core
2882          * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2883          * else is able to provide this information with the write() operation.
2884          */
2885         bool copy_timestamp = !read && q->copy_timestamp;
2886         unsigned index;
2887         int ret;
2888
2889         dprintk(q, 3, "mode %s, offset %ld, count %zd, %sblocking\n",
2890                 read ? "read" : "write", (long)*ppos, count,
2891                 nonblock ? "non" : "");
2892
2893         if (!data)
2894                 return -EINVAL;
2895
2896         if (q->waiting_in_dqbuf) {
2897                 dprintk(q, 3, "another dup()ped fd is %s\n",
2898                         read ? "reading" : "writing");
2899                 return -EBUSY;
2900         }
2901
2902         /*
2903          * Initialize emulator on first call.
2904          */
2905         if (!vb2_fileio_is_active(q)) {
2906                 ret = __vb2_init_fileio(q, read);
2907                 dprintk(q, 3, "vb2_init_fileio result: %d\n", ret);
2908                 if (ret)
2909                         return ret;
2910         }
2911         fileio = q->fileio;
2912
2913         /*
2914          * Check if we need to dequeue the buffer.
2915          */
2916         index = fileio->cur_index;
2917         if (index >= vb2_get_num_buffers(q)) {
2918                 struct vb2_buffer *b;
2919
2920                 /*
2921                  * Call vb2_dqbuf to get buffer back.
2922                  */
2923                 ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2924                 dprintk(q, 5, "vb2_dqbuf result: %d\n", ret);
2925                 if (ret)
2926                         return ret;
2927                 fileio->dq_count += 1;
2928
2929                 fileio->cur_index = index;
2930                 buf = &fileio->bufs[index];
2931
2932                 /* b can never be NULL when using fileio. */
2933                 b = vb2_get_buffer(q, index);
2934
2935                 /*
2936                  * Get number of bytes filled by the driver
2937                  */
2938                 buf->pos = 0;
2939                 buf->queued = 0;
2940                 buf->size = read ? vb2_get_plane_payload(b, 0)
2941                                  : vb2_plane_size(b, 0);
2942                 /* Compensate for data_offset on read in the multiplanar case. */
2943                 if (is_multiplanar && read &&
2944                                 b->planes[0].data_offset < buf->size) {
2945                         buf->pos = b->planes[0].data_offset;
2946                         buf->size -= buf->pos;
2947                 }
2948         } else {
2949                 buf = &fileio->bufs[index];
2950         }
2951
2952         /*
2953          * Limit count on last few bytes of the buffer.
2954          */
2955         if (buf->pos + count > buf->size) {
2956                 count = buf->size - buf->pos;
2957                 dprintk(q, 5, "reducing read count: %zd\n", count);
2958         }
2959
2960         /*
2961          * Transfer data to userspace.
2962          */
2963         dprintk(q, 3, "copying %zd bytes - buffer %d, offset %u\n",
2964                 count, index, buf->pos);
2965         if (read)
2966                 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2967         else
2968                 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2969         if (ret) {
2970                 dprintk(q, 3, "error copying data\n");
2971                 return -EFAULT;
2972         }
2973
2974         /*
2975          * Update counters.
2976          */
2977         buf->pos += count;
2978         *ppos += count;
2979
2980         /*
2981          * Queue next buffer if required.
2982          */
2983         if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2984                 /* b can never be NULL when using fileio. */
2985                 struct vb2_buffer *b = vb2_get_buffer(q, index);
2986
2987                 /*
2988                  * Check if this is the last buffer to read.
2989                  */
2990                 if (read && fileio->read_once && fileio->dq_count == 1) {
2991                         dprintk(q, 3, "read limit reached\n");
2992                         return __vb2_cleanup_fileio(q);
2993                 }
2994
2995                 /*
2996                  * Call vb2_qbuf and give buffer to the driver.
2997                  */
2998                 b->planes[0].bytesused = buf->pos;
2999
3000                 if (copy_timestamp)
3001                         b->timestamp = ktime_get_ns();
3002                 ret = vb2_core_qbuf(q, b, NULL, NULL);
3003                 dprintk(q, 5, "vb2_qbuf result: %d\n", ret);
3004                 if (ret)
3005                         return ret;
3006
3007                 /*
3008                  * Buffer has been queued, update the status
3009                  */
3010                 buf->pos = 0;
3011                 buf->queued = 1;
3012                 buf->size = vb2_plane_size(b, 0);
3013                 fileio->q_count += 1;
3014                 /*
3015                  * If we are queuing up buffers for the first time, then
3016                  * increase initial_index by one.
3017                  */
3018                 if (fileio->initial_index < vb2_get_num_buffers(q))
3019                         fileio->initial_index++;
3020                 /*
3021                  * The next buffer to use is either a buffer that's going to be
3022                  * queued for the first time (initial_index < number of buffers in the vb2_queue)
3023                  * or it is equal to the number of buffers in the vb2_queue,
3024                  * meaning that the next time we need to dequeue a buffer since
3025                  * we've now queued up all the 'first time' buffers.
3026                  */
3027                 fileio->cur_index = fileio->initial_index;
3028         }
3029
3030         /*
3031          * Return proper number of bytes processed.
3032          */
3033         if (ret == 0)
3034                 ret = count;
3035         return ret;
3036 }
3037
3038 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
3039                 loff_t *ppos, int nonblocking)
3040 {
3041         return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
3042 }
3043 EXPORT_SYMBOL_GPL(vb2_read);
3044
3045 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
3046                 loff_t *ppos, int nonblocking)
3047 {
3048         return __vb2_perform_fileio(q, (char __user *) data, count,
3049                                                         ppos, nonblocking, 0);
3050 }
3051 EXPORT_SYMBOL_GPL(vb2_write);
3052
3053 struct vb2_threadio_data {
3054         struct task_struct *thread;
3055         vb2_thread_fnc fnc;
3056         void *priv;
3057         bool stop;
3058 };
3059
3060 static int vb2_thread(void *data)
3061 {
3062         struct vb2_queue *q = data;
3063         struct vb2_threadio_data *threadio = q->threadio;
3064         bool copy_timestamp = false;
3065         unsigned prequeue = 0;
3066         unsigned index = 0;
3067         int ret = 0;
3068
3069         if (q->is_output) {
3070                 prequeue = vb2_get_num_buffers(q);
3071                 copy_timestamp = q->copy_timestamp;
3072         }
3073
3074         set_freezable();
3075
3076         for (;;) {
3077                 struct vb2_buffer *vb;
3078
3079                 /*
3080                  * Call vb2_dqbuf to get buffer back.
3081                  */
3082                 if (prequeue) {
3083                         vb = vb2_get_buffer(q, index++);
3084                         if (!vb)
3085                                 continue;
3086                         prequeue--;
3087                 } else {
3088                         call_void_qop(q, wait_finish, q);
3089                         if (!threadio->stop)
3090                                 ret = vb2_core_dqbuf(q, &index, NULL, 0);
3091                         call_void_qop(q, wait_prepare, q);
3092                         dprintk(q, 5, "file io: vb2_dqbuf result: %d\n", ret);
3093                         if (!ret)
3094                                 vb = vb2_get_buffer(q, index);
3095                 }
3096                 if (ret || threadio->stop)
3097                         break;
3098                 try_to_freeze();
3099
3100                 if (vb->state != VB2_BUF_STATE_ERROR)
3101                         if (threadio->fnc(vb, threadio->priv))
3102                                 break;
3103                 call_void_qop(q, wait_finish, q);
3104                 if (copy_timestamp)
3105                         vb->timestamp = ktime_get_ns();
3106                 if (!threadio->stop)
3107                         ret = vb2_core_qbuf(q, vb, NULL, NULL);
3108                 call_void_qop(q, wait_prepare, q);
3109                 if (ret || threadio->stop)
3110                         break;
3111         }
3112
3113         /* Hmm, linux becomes *very* unhappy without this ... */
3114         while (!kthread_should_stop()) {
3115                 set_current_state(TASK_INTERRUPTIBLE);
3116                 schedule();
3117         }
3118         return 0;
3119 }
3120
3121 /*
3122  * This function should not be used for anything else but the videobuf2-dvb
3123  * support. If you think you have another good use-case for this, then please
3124  * contact the linux-media mailinglist first.
3125  */
3126 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
3127                      const char *thread_name)
3128 {
3129         struct vb2_threadio_data *threadio;
3130         int ret = 0;
3131
3132         if (q->threadio)
3133                 return -EBUSY;
3134         if (vb2_is_busy(q))
3135                 return -EBUSY;
3136         if (WARN_ON(q->fileio))
3137                 return -EBUSY;
3138
3139         threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
3140         if (threadio == NULL)
3141                 return -ENOMEM;
3142         threadio->fnc = fnc;
3143         threadio->priv = priv;
3144
3145         ret = __vb2_init_fileio(q, !q->is_output);
3146         dprintk(q, 3, "file io: vb2_init_fileio result: %d\n", ret);
3147         if (ret)
3148                 goto nomem;
3149         q->threadio = threadio;
3150         threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
3151         if (IS_ERR(threadio->thread)) {
3152                 ret = PTR_ERR(threadio->thread);
3153                 threadio->thread = NULL;
3154                 goto nothread;
3155         }
3156         return 0;
3157
3158 nothread:
3159         __vb2_cleanup_fileio(q);
3160 nomem:
3161         kfree(threadio);
3162         return ret;
3163 }
3164 EXPORT_SYMBOL_GPL(vb2_thread_start);
3165
3166 int vb2_thread_stop(struct vb2_queue *q)
3167 {
3168         struct vb2_threadio_data *threadio = q->threadio;
3169         int err;
3170
3171         if (threadio == NULL)
3172                 return 0;
3173         threadio->stop = true;
3174         /* Wake up all pending sleeps in the thread */
3175         vb2_queue_error(q);
3176         err = kthread_stop(threadio->thread);
3177         __vb2_cleanup_fileio(q);
3178         threadio->thread = NULL;
3179         kfree(threadio);
3180         q->threadio = NULL;
3181         return err;
3182 }
3183 EXPORT_SYMBOL_GPL(vb2_thread_stop);
3184
3185 MODULE_DESCRIPTION("Media buffer core framework");
3186 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3187 MODULE_LICENSE("GPL");
3188 MODULE_IMPORT_NS(DMA_BUF);