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

   1 /*
   2  * videobuf2-core.c - video buffer 2 core framework
   3  *
   4  * Copyright (C) 2010 Samsung Electronics
   5  *
   6  * Author: Pawel Osciak <pawel@osciak.com>
   7  *         Marek Szyprowski <m.szyprowski@samsung.com>
   8  *
   9  * The vb2_thread implementation was based on code from videobuf-dvb.c:
  10  *      (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation.
  15  */
  16
  17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  18
  19 #include <linux/err.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/mm.h>
  23 #include <linux/poll.h>
  24 #include <linux/slab.h>
  25 #include <linux/sched.h>
  26 #include <linux/freezer.h>
  27 #include <linux/kthread.h>
  28
  29 #include <media/videobuf2-core.h>
  30 #include <media/v4l2-mc.h>
  31
  32 #include <trace/events/vb2.h>
  33
  34 static int debug;
  35 module_param(debug, int, 0644);
  36
  37 #define dprintk(level, fmt, arg...)                             \
  38         do {                                                    \
  39                 if (debug >= level)                             \
  40                         pr_info("%s: " fmt, __func__, ## arg);  \
  41         } while (0)
  42
  43 #ifdef CONFIG_VIDEO_ADV_DEBUG
  44
  45 /*
  46  * If advanced debugging is on, then count how often each op is called
  47  * successfully, which can either be per-buffer or per-queue.
  48  *
  49  * This makes it easy to check that the 'init' and 'cleanup'
  50  * (and variations thereof) stay balanced.
  51  */
  52
  53 #define log_memop(vb, op)                                               \
  54         dprintk(2, "call_memop(%p, %d, %s)%s\n",                        \
  55                 (vb)->vb2_queue, (vb)->index, #op,                      \
  56                 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
  57
  58 #define call_memop(vb, op, args...)                                     \
  59 ({                                                                      \
  60         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  61         int err;                                                        \
  62                                                                         \
  63         log_memop(vb, op);                                              \
  64         err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0;              \
  65         if (!err)                                                       \
  66                 (vb)->cnt_mem_ ## op++;                                 \
  67         err;                                                            \
  68 })
  69
  70 #define call_ptr_memop(vb, op, args...)                                 \
  71 ({                                                                      \
  72         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  73         void *ptr;                                                      \
  74                                                                         \
  75         log_memop(vb, op);                                              \
  76         ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL;           \
  77         if (!IS_ERR_OR_NULL(ptr))                                       \
  78                 (vb)->cnt_mem_ ## op++;                                 \
  79         ptr;                                                            \
  80 })
  81
  82 #define call_void_memop(vb, op, args...)                                \
  83 ({                                                                      \
  84         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  85                                                                         \
  86         log_memop(vb, op);                                              \
  87         if (_q->mem_ops->op)                                            \
  88                 _q->mem_ops->op(args);                                  \
  89         (vb)->cnt_mem_ ## op++;                                         \
  90 })
  91
  92 #define log_qop(q, op)                                                  \
  93         dprintk(2, "call_qop(%p, %s)%s\n", q, #op,                      \
  94                 (q)->ops->op ? "" : " (nop)")
  95
  96 #define call_qop(q, op, args...)                                        \
  97 ({                                                                      \
  98         int err;                                                        \
  99                                                                         \
 100         log_qop(q, op);                                                 \
 101         err = (q)->ops->op ? (q)->ops->op(args) : 0;                    \
 102         if (!err)                                                       \
 103                 (q)->cnt_ ## op++;                                      \
 104         err;                                                            \
 105 })
 106
 107 #define call_void_qop(q, op, args...)                                   \
 108 ({                                                                      \
 109         log_qop(q, op);                                                 \
 110         if ((q)->ops->op)                                               \
 111                 (q)->ops->op(args);                                     \
 112         (q)->cnt_ ## op++;                                              \
 113 })
 114
 115 #define log_vb_qop(vb, op, args...)                                     \
 116         dprintk(2, "call_vb_qop(%p, %d, %s)%s\n",                       \
 117                 (vb)->vb2_queue, (vb)->index, #op,                      \
 118                 (vb)->vb2_queue->ops->op ? "" : " (nop)")
 119
 120 #define call_vb_qop(vb, op, args...)                                    \
 121 ({                                                                      \
 122         int err;                                                        \
 123                                                                         \
 124         log_vb_qop(vb, op);                                             \
 125         err = (vb)->vb2_queue->ops->op ?                                \
 126                 (vb)->vb2_queue->ops->op(args) : 0;                     \
 127         if (!err)                                                       \
 128                 (vb)->cnt_ ## op++;                                     \
 129         err;                                                            \
 130 })
 131
 132 #define call_void_vb_qop(vb, op, args...)                               \
 133 ({                                                                      \
 134         log_vb_qop(vb, op);                                             \
 135         if ((vb)->vb2_queue->ops->op)                                   \
 136                 (vb)->vb2_queue->ops->op(args);                         \
 137         (vb)->cnt_ ## op++;                                             \
 138 })
 139
 140 #else
 141
 142 #define call_memop(vb, op, args...)                                     \
 143         ((vb)->vb2_queue->mem_ops->op ?                                 \
 144                 (vb)->vb2_queue->mem_ops->op(args) : 0)
 145
 146 #define call_ptr_memop(vb, op, args...)                                 \
 147         ((vb)->vb2_queue->mem_ops->op ?                                 \
 148                 (vb)->vb2_queue->mem_ops->op(args) : NULL)
 149
 150 #define call_void_memop(vb, op, args...)                                \
 151         do {                                                            \
 152                 if ((vb)->vb2_queue->mem_ops->op)                       \
 153                         (vb)->vb2_queue->mem_ops->op(args);             \
 154         } while (0)
 155
 156 #define call_qop(q, op, args...)                                        \
 157         ((q)->ops->op ? (q)->ops->op(args) : 0)
 158
 159 #define call_void_qop(q, op, args...)                                   \
 160         do {                                                            \
 161                 if ((q)->ops->op)                                       \
 162                         (q)->ops->op(args);                             \
 163         } while (0)
 164
 165 #define call_vb_qop(vb, op, args...)                                    \
 166         ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
 167
 168 #define call_void_vb_qop(vb, op, args...)                               \
 169         do {                                                            \
 170                 if ((vb)->vb2_queue->ops->op)                           \
 171                         (vb)->vb2_queue->ops->op(args);                 \
 172         } while (0)
 173
 174 #endif
 175
 176 #define call_bufop(q, op, args...)                                      \
 177 ({                                                                      \
 178         int ret = 0;                                                    \
 179         if (q && q->buf_ops && q->buf_ops->op)                          \
 180                 ret = q->buf_ops->op(args);                             \
 181         ret;                                                            \
 182 })
 183
 184 #define call_void_bufop(q, op, args...)                                 \
 185 ({                                                                      \
 186         if (q && q->buf_ops && q->buf_ops->op)                          \
 187                 q->buf_ops->op(args);                                   \
 188 })
 189
 190 static void __vb2_queue_cancel(struct vb2_queue *q);
 191 static void __enqueue_in_driver(struct vb2_buffer *vb);
 192
 193 /*
 194  * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
 195  */
 196 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
 197 {
 198         struct vb2_queue *q = vb->vb2_queue;
 199         void *mem_priv;
 200         int plane;
 201         int ret = -ENOMEM;
 202
 203         /*
 204          * Allocate memory for all planes in this buffer
 205          * NOTE: mmapped areas should be page aligned
 206          */
 207         for (plane = 0; plane < vb->num_planes; ++plane) {
 208                 unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
 209
 210                 mem_priv = call_ptr_memop(vb, alloc,
 211                                 q->alloc_devs[plane] ? : q->dev,
 212                                 q->dma_attrs, size, q->dma_dir, q->gfp_flags);
 213                 if (IS_ERR_OR_NULL(mem_priv)) {
 214                         if (mem_priv)
 215                                 ret = PTR_ERR(mem_priv);
 216                         goto free;
 217                 }
 218
 219                 /* Associate allocator private data with this plane */
 220                 vb->planes[plane].mem_priv = mem_priv;
 221         }
 222
 223         return 0;
 224 free:
 225         /* Free already allocated memory if one of the allocations failed */
 226         for (; plane > 0; --plane) {
 227                 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
 228                 vb->planes[plane - 1].mem_priv = NULL;
 229         }
 230
 231         return ret;
 232 }
 233
 234 /*
 235  * __vb2_buf_mem_free() - free memory of the given buffer
 236  */
 237 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
 238 {
 239         unsigned int plane;
 240
 241         for (plane = 0; plane < vb->num_planes; ++plane) {
 242                 call_void_memop(vb, put, vb->planes[plane].mem_priv);
 243                 vb->planes[plane].mem_priv = NULL;
 244                 dprintk(3, "freed plane %d of buffer %d\n", plane, vb->index);
 245         }
 246 }
 247
 248 /*
 249  * __vb2_buf_userptr_put() - release userspace memory associated with
 250  * a USERPTR buffer
 251  */
 252 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
 253 {
 254         unsigned int plane;
 255
 256         for (plane = 0; plane < vb->num_planes; ++plane) {
 257                 if (vb->planes[plane].mem_priv)
 258                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
 259                 vb->planes[plane].mem_priv = NULL;
 260         }
 261 }
 262
 263 /*
 264  * __vb2_plane_dmabuf_put() - release memory associated with
 265  * a DMABUF shared plane
 266  */
 267 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
 268 {
 269         if (!p->mem_priv)
 270                 return;
 271
 272         if (p->dbuf_mapped)
 273                 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
 274
 275         call_void_memop(vb, detach_dmabuf, p->mem_priv);
 276         dma_buf_put(p->dbuf);
 277         p->mem_priv = NULL;
 278         p->dbuf = NULL;
 279         p->dbuf_mapped = 0;
 280 }
 281
 282 /*
 283  * __vb2_buf_dmabuf_put() - release memory associated with
 284  * a DMABUF shared buffer
 285  */
 286 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
 287 {
 288         unsigned int plane;
 289
 290         for (plane = 0; plane < vb->num_planes; ++plane)
 291                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
 292 }
 293
 294 /*
 295  * __setup_offsets() - setup unique offsets ("cookies") for every plane in
 296  * the buffer.
 297  */
 298 static void __setup_offsets(struct vb2_buffer *vb)
 299 {
 300         struct vb2_queue *q = vb->vb2_queue;
 301         unsigned int plane;
 302         unsigned long off = 0;
 303
 304         if (vb->index) {
 305                 struct vb2_buffer *prev = q->bufs[vb->index - 1];
 306                 struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
 307
 308                 off = PAGE_ALIGN(p->m.offset + p->length);
 309         }
 310
 311         for (plane = 0; plane < vb->num_planes; ++plane) {
 312                 vb->planes[plane].m.offset = off;
 313
 314                 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
 315                                 vb->index, plane, off);
 316
 317                 off += vb->planes[plane].length;
 318                 off = PAGE_ALIGN(off);
 319         }
 320 }
 321
 322 /*
 323  * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
 324  * video buffer memory for all buffers/planes on the queue and initializes the
 325  * queue
 326  *
 327  * Returns the number of buffers successfully allocated.
 328  */
 329 static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
 330                              unsigned int num_buffers, unsigned int num_planes,
 331                              const unsigned plane_sizes[VB2_MAX_PLANES])
 332 {
 333         unsigned int buffer, plane;
 334         struct vb2_buffer *vb;
 335         int ret;
 336
 337         /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
 338         num_buffers = min_t(unsigned int, num_buffers,
 339                             VB2_MAX_FRAME - q->num_buffers);
 340
 341         for (buffer = 0; buffer < num_buffers; ++buffer) {
 342                 /* Allocate videobuf buffer structures */
 343                 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
 344                 if (!vb) {
 345                         dprintk(1, "memory alloc for buffer struct failed\n");
 346                         break;
 347                 }
 348
 349                 vb->state = VB2_BUF_STATE_DEQUEUED;
 350                 vb->vb2_queue = q;
 351                 vb->num_planes = num_planes;
 352                 vb->index = q->num_buffers + buffer;
 353                 vb->type = q->type;
 354                 vb->memory = memory;
 355                 for (plane = 0; plane < num_planes; ++plane) {
 356                         vb->planes[plane].length = plane_sizes[plane];
 357                         vb->planes[plane].min_length = plane_sizes[plane];
 358                 }
 359                 call_void_bufop(q, init_buffer, vb);
 360
 361                 q->bufs[vb->index] = vb;
 362
 363                 /* Allocate video buffer memory for the MMAP type */
 364                 if (memory == VB2_MEMORY_MMAP) {
 365                         ret = __vb2_buf_mem_alloc(vb);
 366                         if (ret) {
 367                                 dprintk(1, "failed allocating memory for buffer %d\n",
 368                                         buffer);
 369                                 q->bufs[vb->index] = NULL;
 370                                 kfree(vb);
 371                                 break;
 372                         }
 373                         __setup_offsets(vb);
 374                         /*
 375                          * Call the driver-provided buffer initialization
 376                          * callback, if given. An error in initialization
 377                          * results in queue setup failure.
 378                          */
 379                         ret = call_vb_qop(vb, buf_init, vb);
 380                         if (ret) {
 381                                 dprintk(1, "buffer %d %p initialization failed\n",
 382                                         buffer, vb);
 383                                 __vb2_buf_mem_free(vb);
 384                                 q->bufs[vb->index] = NULL;
 385                                 kfree(vb);
 386                                 break;
 387                         }
 388                 }
 389         }
 390
 391         dprintk(1, "allocated %d buffers, %d plane(s) each\n",
 392                         buffer, num_planes);
 393
 394         return buffer;
 395 }
 396
 397 /*
 398  * __vb2_free_mem() - release all video buffer memory for a given queue
 399  */
 400 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
 401 {
 402         unsigned int buffer;
 403         struct vb2_buffer *vb;
 404
 405         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 406              ++buffer) {
 407                 vb = q->bufs[buffer];
 408                 if (!vb)
 409                         continue;
 410
 411                 /* Free MMAP buffers or release USERPTR buffers */
 412                 if (q->memory == VB2_MEMORY_MMAP)
 413                         __vb2_buf_mem_free(vb);
 414                 else if (q->memory == VB2_MEMORY_DMABUF)
 415                         __vb2_buf_dmabuf_put(vb);
 416                 else
 417                         __vb2_buf_userptr_put(vb);
 418         }
 419 }
 420
 421 /*
 422  * __vb2_queue_free() - free buffers at the end of the queue - video memory and
 423  * related information, if no buffers are left return the queue to an
 424  * uninitialized state. Might be called even if the queue has already been freed.
 425  */
 426 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
 427 {
 428         unsigned int buffer;
 429
 430         /*
 431          * Sanity check: when preparing a buffer the queue lock is released for
 432          * a short while (see __buf_prepare for the details), which would allow
 433          * a race with a reqbufs which can call this function. Removing the
 434          * buffers from underneath __buf_prepare is obviously a bad idea, so we
 435          * check if any of the buffers is in the state PREPARING, and if so we
 436          * just return -EAGAIN.
 437          */
 438         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 439              ++buffer) {
 440                 if (q->bufs[buffer] == NULL)
 441                         continue;
 442                 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
 443                         dprintk(1, "preparing buffers, cannot free\n");
 444                         return -EAGAIN;
 445                 }
 446         }
 447
 448         /* Call driver-provided cleanup function for each buffer, if provided */
 449         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 450              ++buffer) {
 451                 struct vb2_buffer *vb = q->bufs[buffer];
 452
 453                 if (vb && vb->planes[0].mem_priv)
 454                         call_void_vb_qop(vb, buf_cleanup, vb);
 455         }
 456
 457         /* Release video buffer memory */
 458         __vb2_free_mem(q, buffers);
 459
 460 #ifdef CONFIG_VIDEO_ADV_DEBUG
 461         /*
 462          * Check that all the calls were balances during the life-time of this
 463          * queue. If not (or if the debug level is 1 or up), then dump the
 464          * counters to the kernel log.
 465          */
 466         if (q->num_buffers) {
 467                 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
 468                                   q->cnt_wait_prepare != q->cnt_wait_finish;
 469
 470                 if (unbalanced || debug) {
 471                         pr_info("counters for queue %p:%s\n", q,
 472                                 unbalanced ? " UNBALANCED!" : "");
 473                         pr_info("     setup: %u start_streaming: %u stop_streaming: %u\n",
 474                                 q->cnt_queue_setup, q->cnt_start_streaming,
 475                                 q->cnt_stop_streaming);
 476                         pr_info("     wait_prepare: %u wait_finish: %u\n",
 477                                 q->cnt_wait_prepare, q->cnt_wait_finish);
 478                 }
 479                 q->cnt_queue_setup = 0;
 480                 q->cnt_wait_prepare = 0;
 481                 q->cnt_wait_finish = 0;
 482                 q->cnt_start_streaming = 0;
 483                 q->cnt_stop_streaming = 0;
 484         }
 485         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 486                 struct vb2_buffer *vb = q->bufs[buffer];
 487                 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
 488                                   vb->cnt_mem_prepare != vb->cnt_mem_finish ||
 489                                   vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
 490                                   vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
 491                                   vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
 492                                   vb->cnt_buf_queue != vb->cnt_buf_done ||
 493                                   vb->cnt_buf_prepare != vb->cnt_buf_finish ||
 494                                   vb->cnt_buf_init != vb->cnt_buf_cleanup;
 495
 496                 if (unbalanced || debug) {
 497                         pr_info("   counters for queue %p, buffer %d:%s\n",
 498                                 q, buffer, unbalanced ? " UNBALANCED!" : "");
 499                         pr_info("     buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
 500                                 vb->cnt_buf_init, vb->cnt_buf_cleanup,
 501                                 vb->cnt_buf_prepare, vb->cnt_buf_finish);
 502                         pr_info("     buf_queue: %u buf_done: %u buf_request_complete: %u\n",
 503                                 vb->cnt_buf_queue, vb->cnt_buf_done,
 504                                 vb->cnt_buf_request_complete);
 505                         pr_info("     alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
 506                                 vb->cnt_mem_alloc, vb->cnt_mem_put,
 507                                 vb->cnt_mem_prepare, vb->cnt_mem_finish,
 508                                 vb->cnt_mem_mmap);
 509                         pr_info("     get_userptr: %u put_userptr: %u\n",
 510                                 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
 511                         pr_info("     attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
 512                                 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
 513                                 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
 514                         pr_info("     get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
 515                                 vb->cnt_mem_get_dmabuf,
 516                                 vb->cnt_mem_num_users,
 517                                 vb->cnt_mem_vaddr,
 518                                 vb->cnt_mem_cookie);
 519                 }
 520         }
 521 #endif
 522
 523         /* Free videobuf buffers */
 524         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 525              ++buffer) {
 526                 kfree(q->bufs[buffer]);
 527                 q->bufs[buffer] = NULL;
 528         }
 529
 530         q->num_buffers -= buffers;
 531         if (!q->num_buffers) {
 532                 q->memory = VB2_MEMORY_UNKNOWN;
 533                 INIT_LIST_HEAD(&q->queued_list);
 534         }
 535         return 0;
 536 }
 537
 538 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
 539 {
 540         unsigned int plane;
 541         for (plane = 0; plane < vb->num_planes; ++plane) {
 542                 void *mem_priv = vb->planes[plane].mem_priv;
 543                 /*
 544                  * If num_users() has not been provided, call_memop
 545                  * will return 0, apparently nobody cares about this
 546                  * case anyway. If num_users() returns more than 1,
 547                  * we are not the only user of the plane's memory.
 548                  */
 549                 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
 550                         return true;
 551         }
 552         return false;
 553 }
 554 EXPORT_SYMBOL(vb2_buffer_in_use);
 555
 556 /*
 557  * __buffers_in_use() - return true if any buffers on the queue are in use and
 558  * the queue cannot be freed (by the means of REQBUFS(0)) call
 559  */
 560 static bool __buffers_in_use(struct vb2_queue *q)
 561 {
 562         unsigned int buffer;
 563         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 564                 if (vb2_buffer_in_use(q, q->bufs[buffer]))
 565                         return true;
 566         }
 567         return false;
 568 }
 569
 570 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
 571 {
 572         call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
 573 }
 574 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
 575
 576 /*
 577  * __verify_userptr_ops() - verify that all memory operations required for
 578  * USERPTR queue type have been provided
 579  */
 580 static int __verify_userptr_ops(struct vb2_queue *q)
 581 {
 582         if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
 583             !q->mem_ops->put_userptr)
 584                 return -EINVAL;
 585
 586         return 0;
 587 }
 588
 589 /*
 590  * __verify_mmap_ops() - verify that all memory operations required for
 591  * MMAP queue type have been provided
 592  */
 593 static int __verify_mmap_ops(struct vb2_queue *q)
 594 {
 595         if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
 596             !q->mem_ops->put || !q->mem_ops->mmap)
 597                 return -EINVAL;
 598
 599         return 0;
 600 }
 601
 602 /*
 603  * __verify_dmabuf_ops() - verify that all memory operations required for
 604  * DMABUF queue type have been provided
 605  */
 606 static int __verify_dmabuf_ops(struct vb2_queue *q)
 607 {
 608         if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
 609             !q->mem_ops->detach_dmabuf  || !q->mem_ops->map_dmabuf ||
 610             !q->mem_ops->unmap_dmabuf)
 611                 return -EINVAL;
 612
 613         return 0;
 614 }
 615
 616 int vb2_verify_memory_type(struct vb2_queue *q,
 617                 enum vb2_memory memory, unsigned int type)
 618 {
 619         if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
 620             memory != VB2_MEMORY_DMABUF) {
 621                 dprintk(1, "unsupported memory type\n");
 622                 return -EINVAL;
 623         }
 624
 625         if (type != q->type) {
 626                 dprintk(1, "requested type is incorrect\n");
 627                 return -EINVAL;
 628         }
 629
 630         /*
 631          * Make sure all the required memory ops for given memory type
 632          * are available.
 633          */
 634         if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
 635                 dprintk(1, "MMAP for current setup unsupported\n");
 636                 return -EINVAL;
 637         }
 638
 639         if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
 640                 dprintk(1, "USERPTR for current setup unsupported\n");
 641                 return -EINVAL;
 642         }
 643
 644         if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
 645                 dprintk(1, "DMABUF for current setup unsupported\n");
 646                 return -EINVAL;
 647         }
 648
 649         /*
 650          * Place the busy tests at the end: -EBUSY can be ignored when
 651          * create_bufs is called with count == 0, but count == 0 should still
 652          * do the memory and type validation.
 653          */
 654         if (vb2_fileio_is_active(q)) {
 655                 dprintk(1, "file io in progress\n");
 656                 return -EBUSY;
 657         }
 658         return 0;
 659 }
 660 EXPORT_SYMBOL(vb2_verify_memory_type);
 661
 662 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 663                 unsigned int *count)
 664 {
 665         unsigned int num_buffers, allocated_buffers, num_planes = 0;
 666         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 667         unsigned int i;
 668         int ret;
 669
 670         if (q->streaming) {
 671                 dprintk(1, "streaming active\n");
 672                 return -EBUSY;
 673         }
 674
 675         if (*count == 0 || q->num_buffers != 0 ||
 676             (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory)) {
 677                 /*
 678                  * We already have buffers allocated, so first check if they
 679                  * are not in use and can be freed.
 680                  */
 681                 mutex_lock(&q->mmap_lock);
 682                 if (debug && q->memory == VB2_MEMORY_MMAP &&
 683                     __buffers_in_use(q))
 684                         dprintk(1, "memory in use, orphaning buffers\n");
 685
 686                 /*
 687                  * Call queue_cancel to clean up any buffers in the
 688                  * QUEUED state which is possible if buffers were prepared or
 689                  * queued without ever calling STREAMON.
 690                  */
 691                 __vb2_queue_cancel(q);
 692                 ret = __vb2_queue_free(q, q->num_buffers);
 693                 mutex_unlock(&q->mmap_lock);
 694                 if (ret)
 695                         return ret;
 696
 697                 /*
 698                  * In case of REQBUFS(0) return immediately without calling
 699                  * driver's queue_setup() callback and allocating resources.
 700                  */
 701                 if (*count == 0)
 702                         return 0;
 703         }
 704
 705         /*
 706          * Make sure the requested values and current defaults are sane.
 707          */
 708         WARN_ON(q->min_buffers_needed > VB2_MAX_FRAME);
 709         num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);
 710         num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);
 711         memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 712         q->memory = memory;
 713
 714         /*
 715          * Ask the driver how many buffers and planes per buffer it requires.
 716          * Driver also sets the size and allocator context for each plane.
 717          */
 718         ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
 719                        plane_sizes, q->alloc_devs);
 720         if (ret)
 721                 return ret;
 722
 723         /* Check that driver has set sane values */
 724         if (WARN_ON(!num_planes))
 725                 return -EINVAL;
 726
 727         for (i = 0; i < num_planes; i++)
 728                 if (WARN_ON(!plane_sizes[i]))
 729                         return -EINVAL;
 730
 731         /* Finally, allocate buffers and video memory */
 732         allocated_buffers =
 733                 __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
 734         if (allocated_buffers == 0) {
 735                 dprintk(1, "memory allocation failed\n");
 736                 return -ENOMEM;
 737         }
 738
 739         /*
 740          * There is no point in continuing if we can't allocate the minimum
 741          * number of buffers needed by this vb2_queue.
 742          */
 743         if (allocated_buffers < q->min_buffers_needed)
 744                 ret = -ENOMEM;
 745
 746         /*
 747          * Check if driver can handle the allocated number of buffers.
 748          */
 749         if (!ret && allocated_buffers < num_buffers) {
 750                 num_buffers = allocated_buffers;
 751                 /*
 752                  * num_planes is set by the previous queue_setup(), but since it
 753                  * signals to queue_setup() whether it is called from create_bufs()
 754                  * vs reqbufs() we zero it here to signal that queue_setup() is
 755                  * called for the reqbufs() case.
 756                  */
 757                 num_planes = 0;
 758
 759                 ret = call_qop(q, queue_setup, q, &num_buffers,
 760                                &num_planes, plane_sizes, q->alloc_devs);
 761
 762                 if (!ret && allocated_buffers < num_buffers)
 763                         ret = -ENOMEM;
 764
 765                 /*
 766                  * Either the driver has accepted a smaller number of buffers,
 767                  * or .queue_setup() returned an error
 768                  */
 769         }
 770
 771         mutex_lock(&q->mmap_lock);
 772         q->num_buffers = allocated_buffers;
 773
 774         if (ret < 0) {
 775                 /*
 776                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 777                  * from q->num_buffers.
 778                  */
 779                 __vb2_queue_free(q, allocated_buffers);
 780                 mutex_unlock(&q->mmap_lock);
 781                 return ret;
 782         }
 783         mutex_unlock(&q->mmap_lock);
 784
 785         /*
 786          * Return the number of successfully allocated buffers
 787          * to the userspace.
 788          */
 789         *count = allocated_buffers;
 790         q->waiting_for_buffers = !q->is_output;
 791
 792         return 0;
 793 }
 794 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
 795
 796 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 797                 unsigned int *count, unsigned requested_planes,
 798                 const unsigned requested_sizes[])
 799 {
 800         unsigned int num_planes = 0, num_buffers, allocated_buffers;
 801         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 802         int ret;
 803
 804         if (q->num_buffers == VB2_MAX_FRAME) {
 805                 dprintk(1, "maximum number of buffers already allocated\n");
 806                 return -ENOBUFS;
 807         }
 808
 809         if (!q->num_buffers) {
 810                 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 811                 q->memory = memory;
 812                 q->waiting_for_buffers = !q->is_output;
 813         } else if (q->memory != memory) {
 814                 dprintk(1, "memory model mismatch\n");
 815                 return -EINVAL;
 816         }
 817
 818         num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
 819
 820         if (requested_planes && requested_sizes) {
 821                 num_planes = requested_planes;
 822                 memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
 823         }
 824
 825         /*
 826          * Ask the driver, whether the requested number of buffers, planes per
 827          * buffer and their sizes are acceptable
 828          */
 829         ret = call_qop(q, queue_setup, q, &num_buffers,
 830                        &num_planes, plane_sizes, q->alloc_devs);
 831         if (ret)
 832                 return ret;
 833
 834         /* Finally, allocate buffers and video memory */
 835         allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
 836                                 num_planes, plane_sizes);
 837         if (allocated_buffers == 0) {
 838                 dprintk(1, "memory allocation failed\n");
 839                 return -ENOMEM;
 840         }
 841
 842         /*
 843          * Check if driver can handle the so far allocated number of buffers.
 844          */
 845         if (allocated_buffers < num_buffers) {
 846                 num_buffers = allocated_buffers;
 847
 848                 /*
 849                  * q->num_buffers contains the total number of buffers, that the
 850                  * queue driver has set up
 851                  */
 852                 ret = call_qop(q, queue_setup, q, &num_buffers,
 853                                &num_planes, plane_sizes, q->alloc_devs);
 854
 855                 if (!ret && allocated_buffers < num_buffers)
 856                         ret = -ENOMEM;
 857
 858                 /*
 859                  * Either the driver has accepted a smaller number of buffers,
 860                  * or .queue_setup() returned an error
 861                  */
 862         }
 863
 864         mutex_lock(&q->mmap_lock);
 865         q->num_buffers += allocated_buffers;
 866
 867         if (ret < 0) {
 868                 /*
 869                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 870                  * from q->num_buffers.
 871                  */
 872                 __vb2_queue_free(q, allocated_buffers);
 873                 mutex_unlock(&q->mmap_lock);
 874                 return -ENOMEM;
 875         }
 876         mutex_unlock(&q->mmap_lock);
 877
 878         /*
 879          * Return the number of successfully allocated buffers
 880          * to the userspace.
 881          */
 882         *count = allocated_buffers;
 883
 884         return 0;
 885 }
 886 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
 887
 888 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
 889 {
 890         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
 891                 return NULL;
 892
 893         return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
 894
 895 }
 896 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
 897
 898 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
 899 {
 900         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
 901                 return NULL;
 902
 903         return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
 904 }
 905 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
 906
 907 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
 908 {
 909         struct vb2_queue *q = vb->vb2_queue;
 910         unsigned long flags;
 911         unsigned int plane;
 912
 913         if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
 914                 return;
 915
 916         if (WARN_ON(state != VB2_BUF_STATE_DONE &&
 917                     state != VB2_BUF_STATE_ERROR &&
 918                     state != VB2_BUF_STATE_QUEUED &&
 919                     state != VB2_BUF_STATE_REQUEUEING))
 920                 state = VB2_BUF_STATE_ERROR;
 921
 922 #ifdef CONFIG_VIDEO_ADV_DEBUG
 923         /*
 924          * Although this is not a callback, it still does have to balance
 925          * with the buf_queue op. So update this counter manually.
 926          */
 927         vb->cnt_buf_done++;
 928 #endif
 929         dprintk(4, "done processing on buffer %d, state: %d\n",
 930                         vb->index, state);
 931
 932         if (state != VB2_BUF_STATE_QUEUED &&
 933             state != VB2_BUF_STATE_REQUEUEING) {
 934                 /* sync buffers */
 935                 for (plane = 0; plane < vb->num_planes; ++plane)
 936                         call_void_memop(vb, finish, vb->planes[plane].mem_priv);
 937                 vb->synced = false;
 938         }
 939
 940         spin_lock_irqsave(&q->done_lock, flags);
 941         if (state == VB2_BUF_STATE_QUEUED ||
 942             state == VB2_BUF_STATE_REQUEUEING) {
 943                 vb->state = VB2_BUF_STATE_QUEUED;
 944         } else {
 945                 /* Add the buffer to the done buffers list */
 946                 list_add_tail(&vb->done_entry, &q->done_list);
 947                 vb->state = state;
 948         }
 949         atomic_dec(&q->owned_by_drv_count);
 950
 951         if (state != VB2_BUF_STATE_QUEUED && vb->req_obj.req) {
 952                 /* This is not supported at the moment */
 953                 WARN_ON(state == VB2_BUF_STATE_REQUEUEING);
 954                 media_request_object_unbind(&vb->req_obj);
 955                 media_request_object_put(&vb->req_obj);
 956         }
 957
 958         spin_unlock_irqrestore(&q->done_lock, flags);
 959
 960         trace_vb2_buf_done(q, vb);
 961
 962         switch (state) {
 963         case VB2_BUF_STATE_QUEUED:
 964                 return;
 965         case VB2_BUF_STATE_REQUEUEING:
 966                 if (q->start_streaming_called)
 967                         __enqueue_in_driver(vb);
 968                 return;
 969         default:
 970                 /* Inform any processes that may be waiting for buffers */
 971                 wake_up(&q->done_wq);
 972                 break;
 973         }
 974 }
 975 EXPORT_SYMBOL_GPL(vb2_buffer_done);
 976
 977 void vb2_discard_done(struct vb2_queue *q)
 978 {
 979         struct vb2_buffer *vb;
 980         unsigned long flags;
 981
 982         spin_lock_irqsave(&q->done_lock, flags);
 983         list_for_each_entry(vb, &q->done_list, done_entry)
 984                 vb->state = VB2_BUF_STATE_ERROR;
 985         spin_unlock_irqrestore(&q->done_lock, flags);
 986 }
 987 EXPORT_SYMBOL_GPL(vb2_discard_done);
 988
 989 /*
 990  * __prepare_mmap() - prepare an MMAP buffer
 991  */
 992 static int __prepare_mmap(struct vb2_buffer *vb)
 993 {
 994         int ret = 0;
 995
 996         ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
 997                          vb, vb->planes);
 998         return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
 999 }
1000
1001 /*
1002  * __prepare_userptr() - prepare a USERPTR buffer
1003  */
1004 static int __prepare_userptr(struct vb2_buffer *vb)
1005 {
1006         struct vb2_plane planes[VB2_MAX_PLANES];
1007         struct vb2_queue *q = vb->vb2_queue;
1008         void *mem_priv;
1009         unsigned int plane;
1010         int ret = 0;
1011         bool reacquired = vb->planes[0].mem_priv == NULL;
1012
1013         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1014         /* Copy relevant information provided by the userspace */
1015         ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1016                          vb, planes);
1017         if (ret)
1018                 return ret;
1019
1020         for (plane = 0; plane < vb->num_planes; ++plane) {
1021                 /* Skip the plane if already verified */
1022                 if (vb->planes[plane].m.userptr &&
1023                         vb->planes[plane].m.userptr == planes[plane].m.userptr
1024                         && vb->planes[plane].length == planes[plane].length)
1025                         continue;
1026
1027                 dprintk(3, "userspace address for plane %d changed, reacquiring memory\n",
1028                         plane);
1029
1030                 /* Check if the provided plane buffer is large enough */
1031                 if (planes[plane].length < vb->planes[plane].min_length) {
1032                         dprintk(1, "provided buffer size %u is less than setup size %u for plane %d\n",
1033                                                 planes[plane].length,
1034                                                 vb->planes[plane].min_length,
1035                                                 plane);
1036                         ret = -EINVAL;
1037                         goto err;
1038                 }
1039
1040                 /* Release previously acquired memory if present */
1041                 if (vb->planes[plane].mem_priv) {
1042                         if (!reacquired) {
1043                                 reacquired = true;
1044                                 call_void_vb_qop(vb, buf_cleanup, vb);
1045                         }
1046                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1047                 }
1048
1049                 vb->planes[plane].mem_priv = NULL;
1050                 vb->planes[plane].bytesused = 0;
1051                 vb->planes[plane].length = 0;
1052                 vb->planes[plane].m.userptr = 0;
1053                 vb->planes[plane].data_offset = 0;
1054
1055                 /* Acquire each plane's memory */
1056                 mem_priv = call_ptr_memop(vb, get_userptr,
1057                                 q->alloc_devs[plane] ? : q->dev,
1058                                 planes[plane].m.userptr,
1059                                 planes[plane].length, q->dma_dir);
1060                 if (IS_ERR(mem_priv)) {
1061                         dprintk(1, "failed acquiring userspace memory for plane %d\n",
1062                                 plane);
1063                         ret = PTR_ERR(mem_priv);
1064                         goto err;
1065                 }
1066                 vb->planes[plane].mem_priv = mem_priv;
1067         }
1068
1069         /*
1070          * Now that everything is in order, copy relevant information
1071          * provided by userspace.
1072          */
1073         for (plane = 0; plane < vb->num_planes; ++plane) {
1074                 vb->planes[plane].bytesused = planes[plane].bytesused;
1075                 vb->planes[plane].length = planes[plane].length;
1076                 vb->planes[plane].m.userptr = planes[plane].m.userptr;
1077                 vb->planes[plane].data_offset = planes[plane].data_offset;
1078         }
1079
1080         if (reacquired) {
1081                 /*
1082                  * One or more planes changed, so we must call buf_init to do
1083                  * the driver-specific initialization on the newly acquired
1084                  * buffer, if provided.
1085                  */
1086                 ret = call_vb_qop(vb, buf_init, vb);
1087                 if (ret) {
1088                         dprintk(1, "buffer initialization failed\n");
1089                         goto err;
1090                 }
1091         }
1092
1093         ret = call_vb_qop(vb, buf_prepare, vb);
1094         if (ret) {
1095                 dprintk(1, "buffer preparation failed\n");
1096                 call_void_vb_qop(vb, buf_cleanup, vb);
1097                 goto err;
1098         }
1099
1100         return 0;
1101 err:
1102         /* In case of errors, release planes that were already acquired */
1103         for (plane = 0; plane < vb->num_planes; ++plane) {
1104                 if (vb->planes[plane].mem_priv)
1105                         call_void_memop(vb, put_userptr,
1106                                 vb->planes[plane].mem_priv);
1107                 vb->planes[plane].mem_priv = NULL;
1108                 vb->planes[plane].m.userptr = 0;
1109                 vb->planes[plane].length = 0;
1110         }
1111
1112         return ret;
1113 }
1114
1115 /*
1116  * __prepare_dmabuf() - prepare a DMABUF buffer
1117  */
1118 static int __prepare_dmabuf(struct vb2_buffer *vb)
1119 {
1120         struct vb2_plane planes[VB2_MAX_PLANES];
1121         struct vb2_queue *q = vb->vb2_queue;
1122         void *mem_priv;
1123         unsigned int plane;
1124         int ret = 0;
1125         bool reacquired = vb->planes[0].mem_priv == NULL;
1126
1127         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1128         /* Copy relevant information provided by the userspace */
1129         ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1130                          vb, planes);
1131         if (ret)
1132                 return ret;
1133
1134         for (plane = 0; plane < vb->num_planes; ++plane) {
1135                 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1136
1137                 if (IS_ERR_OR_NULL(dbuf)) {
1138                         dprintk(1, "invalid dmabuf fd for plane %d\n",
1139                                 plane);
1140                         ret = -EINVAL;
1141                         goto err;
1142                 }
1143
1144                 /* use DMABUF size if length is not provided */
1145                 if (planes[plane].length == 0)
1146                         planes[plane].length = dbuf->size;
1147
1148                 if (planes[plane].length < vb->planes[plane].min_length) {
1149                         dprintk(1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
1150                                 planes[plane].length, plane,
1151                                 vb->planes[plane].min_length);
1152                         dma_buf_put(dbuf);
1153                         ret = -EINVAL;
1154                         goto err;
1155                 }
1156
1157                 /* Skip the plane if already verified */
1158                 if (dbuf == vb->planes[plane].dbuf &&
1159                         vb->planes[plane].length == planes[plane].length) {
1160                         dma_buf_put(dbuf);
1161                         continue;
1162                 }
1163
1164                 dprintk(3, "buffer for plane %d changed\n", plane);
1165
1166                 if (!reacquired) {
1167                         reacquired = true;
1168                         call_void_vb_qop(vb, buf_cleanup, vb);
1169                 }
1170
1171                 /* Release previously acquired memory if present */
1172                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1173                 vb->planes[plane].bytesused = 0;
1174                 vb->planes[plane].length = 0;
1175                 vb->planes[plane].m.fd = 0;
1176                 vb->planes[plane].data_offset = 0;
1177
1178                 /* Acquire each plane's memory */
1179                 mem_priv = call_ptr_memop(vb, attach_dmabuf,
1180                                 q->alloc_devs[plane] ? : q->dev,
1181                                 dbuf, planes[plane].length, q->dma_dir);
1182                 if (IS_ERR(mem_priv)) {
1183                         dprintk(1, "failed to attach dmabuf\n");
1184                         ret = PTR_ERR(mem_priv);
1185                         dma_buf_put(dbuf);
1186                         goto err;
1187                 }
1188
1189                 vb->planes[plane].dbuf = dbuf;
1190                 vb->planes[plane].mem_priv = mem_priv;
1191         }
1192
1193         /*
1194          * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1195          * here instead just before the DMA, while queueing the buffer(s) so
1196          * userspace knows sooner rather than later if the dma-buf map fails.
1197          */
1198         for (plane = 0; plane < vb->num_planes; ++plane) {
1199                 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1200                 if (ret) {
1201                         dprintk(1, "failed to map dmabuf for plane %d\n",
1202                                 plane);
1203                         goto err;
1204                 }
1205                 vb->planes[plane].dbuf_mapped = 1;
1206         }
1207
1208         /*
1209          * Now that everything is in order, copy relevant information
1210          * provided by userspace.
1211          */
1212         for (plane = 0; plane < vb->num_planes; ++plane) {
1213                 vb->planes[plane].bytesused = planes[plane].bytesused;
1214                 vb->planes[plane].length = planes[plane].length;
1215                 vb->planes[plane].m.fd = planes[plane].m.fd;
1216                 vb->planes[plane].data_offset = planes[plane].data_offset;
1217         }
1218
1219         if (reacquired) {
1220                 /*
1221                  * Call driver-specific initialization on the newly acquired buffer,
1222                  * if provided.
1223                  */
1224                 ret = call_vb_qop(vb, buf_init, vb);
1225                 if (ret) {
1226                         dprintk(1, "buffer initialization failed\n");
1227                         goto err;
1228                 }
1229         }
1230
1231         ret = call_vb_qop(vb, buf_prepare, vb);
1232         if (ret) {
1233                 dprintk(1, "buffer preparation failed\n");
1234                 call_void_vb_qop(vb, buf_cleanup, vb);
1235                 goto err;
1236         }
1237
1238         return 0;
1239 err:
1240         /* In case of errors, release planes that were already acquired */
1241         __vb2_buf_dmabuf_put(vb);
1242
1243         return ret;
1244 }
1245
1246 /*
1247  * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1248  */
1249 static void __enqueue_in_driver(struct vb2_buffer *vb)
1250 {
1251         struct vb2_queue *q = vb->vb2_queue;
1252
1253         vb->state = VB2_BUF_STATE_ACTIVE;
1254         atomic_inc(&q->owned_by_drv_count);
1255
1256         trace_vb2_buf_queue(q, vb);
1257
1258         call_void_vb_qop(vb, buf_queue, vb);
1259 }
1260
1261 static int __buf_prepare(struct vb2_buffer *vb)
1262 {
1263         struct vb2_queue *q = vb->vb2_queue;
1264         enum vb2_buffer_state orig_state = vb->state;
1265         unsigned int plane;
1266         int ret;
1267
1268         if (q->error) {
1269                 dprintk(1, "fatal error occurred on queue\n");
1270                 return -EIO;
1271         }
1272
1273         if (vb->prepared)
1274                 return 0;
1275         WARN_ON(vb->synced);
1276
1277         vb->state = VB2_BUF_STATE_PREPARING;
1278
1279         switch (q->memory) {
1280         case VB2_MEMORY_MMAP:
1281                 ret = __prepare_mmap(vb);
1282                 break;
1283         case VB2_MEMORY_USERPTR:
1284                 ret = __prepare_userptr(vb);
1285                 break;
1286         case VB2_MEMORY_DMABUF:
1287                 ret = __prepare_dmabuf(vb);
1288                 break;
1289         default:
1290                 WARN(1, "Invalid queue type\n");
1291                 ret = -EINVAL;
1292                 break;
1293         }
1294
1295         if (ret) {
1296                 dprintk(1, "buffer preparation failed: %d\n", ret);
1297                 vb->state = orig_state;
1298                 return ret;
1299         }
1300
1301         /* sync buffers */
1302         for (plane = 0; plane < vb->num_planes; ++plane)
1303                 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1304
1305         vb->synced = true;
1306         vb->prepared = true;
1307         vb->state = orig_state;
1308
1309         return 0;
1310 }
1311
1312 static int vb2_req_prepare(struct media_request_object *obj)
1313 {
1314         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1315         int ret;
1316
1317         if (WARN_ON(vb->state != VB2_BUF_STATE_IN_REQUEST))
1318                 return -EINVAL;
1319
1320         mutex_lock(vb->vb2_queue->lock);
1321         ret = __buf_prepare(vb);
1322         mutex_unlock(vb->vb2_queue->lock);
1323         return ret;
1324 }
1325
1326 static void __vb2_dqbuf(struct vb2_buffer *vb);
1327
1328 static void vb2_req_unprepare(struct media_request_object *obj)
1329 {
1330         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1331
1332         mutex_lock(vb->vb2_queue->lock);
1333         __vb2_dqbuf(vb);
1334         vb->state = VB2_BUF_STATE_IN_REQUEST;
1335         mutex_unlock(vb->vb2_queue->lock);
1336         WARN_ON(!vb->req_obj.req);
1337 }
1338
1339 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1340                   struct media_request *req);
1341
1342 static void vb2_req_queue(struct media_request_object *obj)
1343 {
1344         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1345
1346         mutex_lock(vb->vb2_queue->lock);
1347         vb2_core_qbuf(vb->vb2_queue, vb->index, NULL, NULL);
1348         mutex_unlock(vb->vb2_queue->lock);
1349 }
1350
1351 static void vb2_req_unbind(struct media_request_object *obj)
1352 {
1353         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1354
1355         if (vb->state == VB2_BUF_STATE_IN_REQUEST)
1356                 call_void_bufop(vb->vb2_queue, init_buffer, vb);
1357 }
1358
1359 static void vb2_req_release(struct media_request_object *obj)
1360 {
1361         struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1362
1363         if (vb->state == VB2_BUF_STATE_IN_REQUEST) {
1364                 vb->state = VB2_BUF_STATE_DEQUEUED;
1365                 if (vb->request)
1366                         media_request_put(vb->request);
1367                 vb->request = NULL;
1368         }
1369 }
1370
1371 static const struct media_request_object_ops vb2_core_req_ops = {
1372         .prepare = vb2_req_prepare,
1373         .unprepare = vb2_req_unprepare,
1374         .queue = vb2_req_queue,
1375         .unbind = vb2_req_unbind,
1376         .release = vb2_req_release,
1377 };
1378
1379 bool vb2_request_object_is_buffer(struct media_request_object *obj)
1380 {
1381         return obj->ops == &vb2_core_req_ops;
1382 }
1383 EXPORT_SYMBOL_GPL(vb2_request_object_is_buffer);
1384
1385 unsigned int vb2_request_buffer_cnt(struct media_request *req)
1386 {
1387         struct media_request_object *obj;
1388         unsigned long flags;
1389         unsigned int buffer_cnt = 0;
1390
1391         spin_lock_irqsave(&req->lock, flags);
1392         list_for_each_entry(obj, &req->objects, list)
1393                 if (vb2_request_object_is_buffer(obj))
1394                         buffer_cnt++;
1395         spin_unlock_irqrestore(&req->lock, flags);
1396
1397         return buffer_cnt;
1398 }
1399 EXPORT_SYMBOL_GPL(vb2_request_buffer_cnt);
1400
1401 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1402 {
1403         struct vb2_buffer *vb;
1404         int ret;
1405
1406         vb = q->bufs[index];
1407         if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1408                 dprintk(1, "invalid buffer state %d\n",
1409                         vb->state);
1410                 return -EINVAL;
1411         }
1412         if (vb->prepared) {
1413                 dprintk(1, "buffer already prepared\n");
1414                 return -EINVAL;
1415         }
1416
1417         ret = __buf_prepare(vb);
1418         if (ret)
1419                 return ret;
1420
1421         /* Fill buffer information for the userspace */
1422         call_void_bufop(q, fill_user_buffer, vb, pb);
1423
1424         dprintk(2, "prepare of buffer %d succeeded\n", vb->index);
1425
1426         return 0;
1427 }
1428 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1429
1430 /*
1431  * vb2_start_streaming() - Attempt to start streaming.
1432  * @q:          videobuf2 queue
1433  *
1434  * Attempt to start streaming. When this function is called there must be
1435  * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1436  * number of buffers required for the DMA engine to function). If the
1437  * @start_streaming op fails it is supposed to return all the driver-owned
1438  * buffers back to vb2 in state QUEUED. Check if that happened and if
1439  * not warn and reclaim them forcefully.
1440  */
1441 static int vb2_start_streaming(struct vb2_queue *q)
1442 {
1443         struct vb2_buffer *vb;
1444         int ret;
1445
1446         /*
1447          * If any buffers were queued before streamon,
1448          * we can now pass them to driver for processing.
1449          */
1450         list_for_each_entry(vb, &q->queued_list, queued_entry)
1451                 __enqueue_in_driver(vb);
1452
1453         /* Tell the driver to start streaming */
1454         q->start_streaming_called = 1;
1455         ret = call_qop(q, start_streaming, q,
1456                        atomic_read(&q->owned_by_drv_count));
1457         if (!ret)
1458                 return 0;
1459
1460         q->start_streaming_called = 0;
1461
1462         dprintk(1, "driver refused to start streaming\n");
1463         /*
1464          * If you see this warning, then the driver isn't cleaning up properly
1465          * after a failed start_streaming(). See the start_streaming()
1466          * documentation in videobuf2-core.h for more information how buffers
1467          * should be returned to vb2 in start_streaming().
1468          */
1469         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1470                 unsigned i;
1471
1472                 /*
1473                  * Forcefully reclaim buffers if the driver did not
1474                  * correctly return them to vb2.
1475                  */
1476                 for (i = 0; i < q->num_buffers; ++i) {
1477                         vb = q->bufs[i];
1478                         if (vb->state == VB2_BUF_STATE_ACTIVE)
1479                                 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1480                 }
1481                 /* Must be zero now */
1482                 WARN_ON(atomic_read(&q->owned_by_drv_count));
1483         }
1484         /*
1485          * If done_list is not empty, then start_streaming() didn't call
1486          * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1487          * STATE_DONE.
1488          */
1489         WARN_ON(!list_empty(&q->done_list));
1490         return ret;
1491 }
1492
1493 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1494                   struct media_request *req)
1495 {
1496         struct vb2_buffer *vb;
1497         int ret;
1498
1499         if (q->error) {
1500                 dprintk(1, "fatal error occurred on queue\n");
1501                 return -EIO;
1502         }
1503
1504         vb = q->bufs[index];
1505
1506         if ((req && q->uses_qbuf) ||
1507             (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1508              q->uses_requests)) {
1509                 dprintk(1, "queue in wrong mode (qbuf vs requests)\n");
1510                 return -EBUSY;
1511         }
1512
1513         if (req) {
1514                 int ret;
1515
1516                 q->uses_requests = 1;
1517                 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1518                         dprintk(1, "buffer %d not in dequeued state\n",
1519                                 vb->index);
1520                         return -EINVAL;
1521                 }
1522
1523                 media_request_object_init(&vb->req_obj);
1524
1525                 /* Make sure the request is in a safe state for updating. */
1526                 ret = media_request_lock_for_update(req);
1527                 if (ret)
1528                         return ret;
1529                 ret = media_request_object_bind(req, &vb2_core_req_ops,
1530                                                 q, true, &vb->req_obj);
1531                 media_request_unlock_for_update(req);
1532                 if (ret)
1533                         return ret;
1534
1535                 vb->state = VB2_BUF_STATE_IN_REQUEST;
1536
1537                 /*
1538                  * Increment the refcount and store the request.
1539                  * The request refcount is decremented again when the
1540                  * buffer is dequeued. This is to prevent vb2_buffer_done()
1541                  * from freeing the request from interrupt context, which can
1542                  * happen if the application closed the request fd after
1543                  * queueing the request.
1544                  */
1545                 media_request_get(req);
1546                 vb->request = req;
1547
1548                 /* Fill buffer information for the userspace */
1549                 if (pb) {
1550                         call_void_bufop(q, copy_timestamp, vb, pb);
1551                         call_void_bufop(q, fill_user_buffer, vb, pb);
1552                 }
1553
1554                 dprintk(2, "qbuf of buffer %d succeeded\n", vb->index);
1555                 return 0;
1556         }
1557
1558         if (vb->state != VB2_BUF_STATE_IN_REQUEST)
1559                 q->uses_qbuf = 1;
1560
1561         switch (vb->state) {
1562         case VB2_BUF_STATE_DEQUEUED:
1563         case VB2_BUF_STATE_IN_REQUEST:
1564                 if (!vb->prepared) {
1565                         ret = __buf_prepare(vb);
1566                         if (ret)
1567                                 return ret;
1568                 }
1569                 break;
1570         case VB2_BUF_STATE_PREPARING:
1571                 dprintk(1, "buffer still being prepared\n");
1572                 return -EINVAL;
1573         default:
1574                 dprintk(1, "invalid buffer state %d\n", vb->state);
1575                 return -EINVAL;
1576         }
1577
1578         /*
1579          * Add to the queued buffers list, a buffer will stay on it until
1580          * dequeued in dqbuf.
1581          */
1582         list_add_tail(&vb->queued_entry, &q->queued_list);
1583         q->queued_count++;
1584         q->waiting_for_buffers = false;
1585         vb->state = VB2_BUF_STATE_QUEUED;
1586
1587         if (pb)
1588                 call_void_bufop(q, copy_timestamp, vb, pb);
1589
1590         trace_vb2_qbuf(q, vb);
1591
1592         /*
1593          * If already streaming, give the buffer to driver for processing.
1594          * If not, the buffer will be given to driver on next streamon.
1595          */
1596         if (q->start_streaming_called)
1597                 __enqueue_in_driver(vb);
1598
1599         /* Fill buffer information for the userspace */
1600         if (pb)
1601                 call_void_bufop(q, fill_user_buffer, vb, pb);
1602
1603         /*
1604          * If streamon has been called, and we haven't yet called
1605          * start_streaming() since not enough buffers were queued, and
1606          * we now have reached the minimum number of queued buffers,
1607          * then we can finally call start_streaming().
1608          */
1609         if (q->streaming && !q->start_streaming_called &&
1610             q->queued_count >= q->min_buffers_needed) {
1611                 ret = vb2_start_streaming(q);
1612                 if (ret)
1613                         return ret;
1614         }
1615
1616         dprintk(2, "qbuf of buffer %d succeeded\n", vb->index);
1617         return 0;
1618 }
1619 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1620
1621 /*
1622  * __vb2_wait_for_done_vb() - wait for a buffer to become available
1623  * for dequeuing
1624  *
1625  * Will sleep if required for nonblocking == false.
1626  */
1627 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1628 {
1629         /*
1630          * All operations on vb_done_list are performed under done_lock
1631          * spinlock protection. However, buffers may be removed from
1632          * it and returned to userspace only while holding both driver's
1633          * lock and the done_lock spinlock. Thus we can be sure that as
1634          * long as we hold the driver's lock, the list will remain not
1635          * empty if list_empty() check succeeds.
1636          */
1637
1638         for (;;) {
1639                 int ret;
1640
1641                 if (!q->streaming) {
1642                         dprintk(1, "streaming off, will not wait for buffers\n");
1643                         return -EINVAL;
1644                 }
1645
1646                 if (q->error) {
1647                         dprintk(1, "Queue in error state, will not wait for buffers\n");
1648                         return -EIO;
1649                 }
1650
1651                 if (q->last_buffer_dequeued) {
1652                         dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1653                         return -EPIPE;
1654                 }
1655
1656                 if (!list_empty(&q->done_list)) {
1657                         /*
1658                          * Found a buffer that we were waiting for.
1659                          */
1660                         break;
1661                 }
1662
1663                 if (nonblocking) {
1664                         dprintk(3, "nonblocking and no buffers to dequeue, will not wait\n");
1665                         return -EAGAIN;
1666                 }
1667
1668                 /*
1669                  * We are streaming and blocking, wait for another buffer to
1670                  * become ready or for streamoff. Driver's lock is released to
1671                  * allow streamoff or qbuf to be called while waiting.
1672                  */
1673                 call_void_qop(q, wait_prepare, q);
1674
1675                 /*
1676                  * All locks have been released, it is safe to sleep now.
1677                  */
1678                 dprintk(3, "will sleep waiting for buffers\n");
1679                 ret = wait_event_interruptible(q->done_wq,
1680                                 !list_empty(&q->done_list) || !q->streaming ||
1681                                 q->error);
1682
1683                 /*
1684                  * We need to reevaluate both conditions again after reacquiring
1685                  * the locks or return an error if one occurred.
1686                  */
1687                 call_void_qop(q, wait_finish, q);
1688                 if (ret) {
1689                         dprintk(1, "sleep was interrupted\n");
1690                         return ret;
1691                 }
1692         }
1693         return 0;
1694 }
1695
1696 /*
1697  * __vb2_get_done_vb() - get a buffer ready for dequeuing
1698  *
1699  * Will sleep if required for nonblocking == false.
1700  */
1701 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1702                              void *pb, int nonblocking)
1703 {
1704         unsigned long flags;
1705         int ret = 0;
1706
1707         /*
1708          * Wait for at least one buffer to become available on the done_list.
1709          */
1710         ret = __vb2_wait_for_done_vb(q, nonblocking);
1711         if (ret)
1712                 return ret;
1713
1714         /*
1715          * Driver's lock has been held since we last verified that done_list
1716          * is not empty, so no need for another list_empty(done_list) check.
1717          */
1718         spin_lock_irqsave(&q->done_lock, flags);
1719         *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1720         /*
1721          * Only remove the buffer from done_list if all planes can be
1722          * handled. Some cases such as V4L2 file I/O and DVB have pb
1723          * == NULL; skip the check then as there's nothing to verify.
1724          */
1725         if (pb)
1726                 ret = call_bufop(q, verify_planes_array, *vb, pb);
1727         if (!ret)
1728                 list_del(&(*vb)->done_entry);
1729         spin_unlock_irqrestore(&q->done_lock, flags);
1730
1731         return ret;
1732 }
1733
1734 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1735 {
1736         if (!q->streaming) {
1737                 dprintk(1, "streaming off, will not wait for buffers\n");
1738                 return -EINVAL;
1739         }
1740
1741         if (q->start_streaming_called)
1742                 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1743         return 0;
1744 }
1745 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1746
1747 /*
1748  * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1749  */
1750 static void __vb2_dqbuf(struct vb2_buffer *vb)
1751 {
1752         struct vb2_queue *q = vb->vb2_queue;
1753         unsigned int i;
1754
1755         /* nothing to do if the buffer is already dequeued */
1756         if (vb->state == VB2_BUF_STATE_DEQUEUED)
1757                 return;
1758
1759         vb->state = VB2_BUF_STATE_DEQUEUED;
1760
1761         /* unmap DMABUF buffer */
1762         if (q->memory == VB2_MEMORY_DMABUF)
1763                 for (i = 0; i < vb->num_planes; ++i) {
1764                         if (!vb->planes[i].dbuf_mapped)
1765                                 continue;
1766                         call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
1767                         vb->planes[i].dbuf_mapped = 0;
1768                 }
1769         call_void_bufop(q, init_buffer, vb);
1770 }
1771
1772 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1773                    bool nonblocking)
1774 {
1775         struct vb2_buffer *vb = NULL;
1776         int ret;
1777
1778         ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1779         if (ret < 0)
1780                 return ret;
1781
1782         switch (vb->state) {
1783         case VB2_BUF_STATE_DONE:
1784                 dprintk(3, "returning done buffer\n");
1785                 break;
1786         case VB2_BUF_STATE_ERROR:
1787                 dprintk(3, "returning done buffer with errors\n");
1788                 break;
1789         default:
1790                 dprintk(1, "invalid buffer state\n");
1791                 return -EINVAL;
1792         }
1793
1794         call_void_vb_qop(vb, buf_finish, vb);
1795         vb->prepared = false;
1796
1797         if (pindex)
1798                 *pindex = vb->index;
1799
1800         /* Fill buffer information for the userspace */
1801         if (pb)
1802                 call_void_bufop(q, fill_user_buffer, vb, pb);
1803
1804         /* Remove from videobuf queue */
1805         list_del(&vb->queued_entry);
1806         q->queued_count--;
1807
1808         trace_vb2_dqbuf(q, vb);
1809
1810         /* go back to dequeued state */
1811         __vb2_dqbuf(vb);
1812
1813         if (WARN_ON(vb->req_obj.req)) {
1814                 media_request_object_unbind(&vb->req_obj);
1815                 media_request_object_put(&vb->req_obj);
1816         }
1817         if (vb->request)
1818                 media_request_put(vb->request);
1819         vb->request = NULL;
1820
1821         dprintk(2, "dqbuf of buffer %d, with state %d\n",
1822                         vb->index, vb->state);
1823
1824         return 0;
1825
1826 }
1827 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
1828
1829 /*
1830  * __vb2_queue_cancel() - cancel and stop (pause) streaming
1831  *
1832  * Removes all queued buffers from driver's queue and all buffers queued by
1833  * userspace from videobuf's queue. Returns to state after reqbufs.
1834  */
1835 static void __vb2_queue_cancel(struct vb2_queue *q)
1836 {
1837         unsigned int i;
1838
1839         /*
1840          * Tell driver to stop all transactions and release all queued
1841          * buffers.
1842          */
1843         if (q->start_streaming_called)
1844                 call_void_qop(q, stop_streaming, q);
1845
1846         /*
1847          * If you see this warning, then the driver isn't cleaning up properly
1848          * in stop_streaming(). See the stop_streaming() documentation in
1849          * videobuf2-core.h for more information how buffers should be returned
1850          * to vb2 in stop_streaming().
1851          */
1852         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1853                 for (i = 0; i < q->num_buffers; ++i)
1854                         if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE) {
1855                                 pr_warn("driver bug: stop_streaming operation is leaving buf %p in active state\n",
1856                                         q->bufs[i]);
1857                                 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
1858                         }
1859                 /* Must be zero now */
1860                 WARN_ON(atomic_read(&q->owned_by_drv_count));
1861         }
1862
1863         q->streaming = 0;
1864         q->start_streaming_called = 0;
1865         q->queued_count = 0;
1866         q->error = 0;
1867         q->uses_requests = 0;
1868         q->uses_qbuf = 0;
1869
1870         /*
1871          * Remove all buffers from videobuf's list...
1872          */
1873         INIT_LIST_HEAD(&q->queued_list);
1874         /*
1875          * ...and done list; userspace will not receive any buffers it
1876          * has not already dequeued before initiating cancel.
1877          */
1878         INIT_LIST_HEAD(&q->done_list);
1879         atomic_set(&q->owned_by_drv_count, 0);
1880         wake_up_all(&q->done_wq);
1881
1882         /*
1883          * Reinitialize all buffers for next use.
1884          * Make sure to call buf_finish for any queued buffers. Normally
1885          * that's done in dqbuf, but that's not going to happen when we
1886          * cancel the whole queue. Note: this code belongs here, not in
1887          * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
1888          * call to __fill_user_buffer() after buf_finish(). That order can't
1889          * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
1890          */
1891         for (i = 0; i < q->num_buffers; ++i) {
1892                 struct vb2_buffer *vb = q->bufs[i];
1893                 struct media_request *req = vb->req_obj.req;
1894
1895                 /*
1896                  * If a request is associated with this buffer, then
1897                  * call buf_request_cancel() to give the driver to complete()
1898                  * related request objects. Otherwise those objects would
1899                  * never complete.
1900                  */
1901                 if (req) {
1902                         enum media_request_state state;
1903                         unsigned long flags;
1904
1905                         spin_lock_irqsave(&req->lock, flags);
1906                         state = req->state;
1907                         spin_unlock_irqrestore(&req->lock, flags);
1908
1909                         if (state == MEDIA_REQUEST_STATE_QUEUED)
1910                                 call_void_vb_qop(vb, buf_request_complete, vb);
1911                 }
1912
1913                 if (vb->synced) {
1914                         unsigned int plane;
1915
1916                         for (plane = 0; plane < vb->num_planes; ++plane)
1917                                 call_void_memop(vb, finish,
1918                                                 vb->planes[plane].mem_priv);
1919                         vb->synced = false;
1920                 }
1921
1922                 if (vb->prepared) {
1923                         call_void_vb_qop(vb, buf_finish, vb);
1924                         vb->prepared = false;
1925                 }
1926                 __vb2_dqbuf(vb);
1927
1928                 if (vb->req_obj.req) {
1929                         media_request_object_unbind(&vb->req_obj);
1930                         media_request_object_put(&vb->req_obj);
1931                 }
1932                 if (vb->request)
1933                         media_request_put(vb->request);
1934                 vb->request = NULL;
1935         }
1936 }
1937
1938 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
1939 {
1940         int ret;
1941
1942         if (type != q->type) {
1943                 dprintk(1, "invalid stream type\n");
1944                 return -EINVAL;
1945         }
1946
1947         if (q->streaming) {
1948                 dprintk(3, "already streaming\n");
1949                 return 0;
1950         }
1951
1952         if (!q->num_buffers) {
1953                 dprintk(1, "no buffers have been allocated\n");
1954                 return -EINVAL;
1955         }
1956
1957         if (q->num_buffers < q->min_buffers_needed) {
1958                 dprintk(1, "need at least %u allocated buffers\n",
1959                                 q->min_buffers_needed);
1960                 return -EINVAL;
1961         }
1962
1963         /*
1964          * Tell driver to start streaming provided sufficient buffers
1965          * are available.
1966          */
1967         if (q->queued_count >= q->min_buffers_needed) {
1968                 ret = v4l_vb2q_enable_media_source(q);
1969                 if (ret)
1970                         return ret;
1971                 ret = vb2_start_streaming(q);
1972                 if (ret)
1973                         return ret;
1974         }
1975
1976         q->streaming = 1;
1977
1978         dprintk(3, "successful\n");
1979         return 0;
1980 }
1981 EXPORT_SYMBOL_GPL(vb2_core_streamon);
1982
1983 void vb2_queue_error(struct vb2_queue *q)
1984 {
1985         q->error = 1;
1986
1987         wake_up_all(&q->done_wq);
1988 }
1989 EXPORT_SYMBOL_GPL(vb2_queue_error);
1990
1991 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
1992 {
1993         if (type != q->type) {
1994                 dprintk(1, "invalid stream type\n");
1995                 return -EINVAL;
1996         }
1997
1998         /*
1999          * Cancel will pause streaming and remove all buffers from the driver
2000          * and videobuf, effectively returning control over them to userspace.
2001          *
2002          * Note that we do this even if q->streaming == 0: if you prepare or
2003          * queue buffers, and then call streamoff without ever having called
2004          * streamon, you would still expect those buffers to be returned to
2005          * their normal dequeued state.
2006          */
2007         __vb2_queue_cancel(q);
2008         q->waiting_for_buffers = !q->is_output;
2009         q->last_buffer_dequeued = false;
2010
2011         dprintk(3, "successful\n");
2012         return 0;
2013 }
2014 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
2015
2016 /*
2017  * __find_plane_by_offset() - find plane associated with the given offset off
2018  */
2019 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2020                         unsigned int *_buffer, unsigned int *_plane)
2021 {
2022         struct vb2_buffer *vb;
2023         unsigned int buffer, plane;
2024
2025         /*
2026          * Go over all buffers and their planes, comparing the given offset
2027          * with an offset assigned to each plane. If a match is found,
2028          * return its buffer and plane numbers.
2029          */
2030         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2031                 vb = q->bufs[buffer];
2032
2033                 for (plane = 0; plane < vb->num_planes; ++plane) {
2034                         if (vb->planes[plane].m.offset == off) {
2035                                 *_buffer = buffer;
2036                                 *_plane = plane;
2037                                 return 0;
2038                         }
2039                 }
2040         }
2041
2042         return -EINVAL;
2043 }
2044
2045 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
2046                 unsigned int index, unsigned int plane, unsigned int flags)
2047 {
2048         struct vb2_buffer *vb = NULL;
2049         struct vb2_plane *vb_plane;
2050         int ret;
2051         struct dma_buf *dbuf;
2052
2053         if (q->memory != VB2_MEMORY_MMAP) {
2054                 dprintk(1, "queue is not currently set up for mmap\n");
2055                 return -EINVAL;
2056         }
2057
2058         if (!q->mem_ops->get_dmabuf) {
2059                 dprintk(1, "queue does not support DMA buffer exporting\n");
2060                 return -EINVAL;
2061         }
2062
2063         if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
2064                 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2065                 return -EINVAL;
2066         }
2067
2068         if (type != q->type) {
2069                 dprintk(1, "invalid buffer type\n");
2070                 return -EINVAL;
2071         }
2072
2073         if (index >= q->num_buffers) {
2074                 dprintk(1, "buffer index out of range\n");
2075                 return -EINVAL;
2076         }
2077
2078         vb = q->bufs[index];
2079
2080         if (plane >= vb->num_planes) {
2081                 dprintk(1, "buffer plane out of range\n");
2082                 return -EINVAL;
2083         }
2084
2085         if (vb2_fileio_is_active(q)) {
2086                 dprintk(1, "expbuf: file io in progress\n");
2087                 return -EBUSY;
2088         }
2089
2090         vb_plane = &vb->planes[plane];
2091
2092         dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv,
2093                                 flags & O_ACCMODE);
2094         if (IS_ERR_OR_NULL(dbuf)) {
2095                 dprintk(1, "failed to export buffer %d, plane %d\n",
2096                         index, plane);
2097                 return -EINVAL;
2098         }
2099
2100         ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
2101         if (ret < 0) {
2102                 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2103                         index, plane, ret);
2104                 dma_buf_put(dbuf);
2105                 return ret;
2106         }
2107
2108         dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2109                 index, plane, ret);
2110         *fd = ret;
2111
2112         return 0;
2113 }
2114 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
2115
2116 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2117 {
2118         unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2119         struct vb2_buffer *vb;
2120         unsigned int buffer = 0, plane = 0;
2121         int ret;
2122         unsigned long length;
2123
2124         if (q->memory != VB2_MEMORY_MMAP) {
2125                 dprintk(1, "queue is not currently set up for mmap\n");
2126                 return -EINVAL;
2127         }
2128
2129         /*
2130          * Check memory area access mode.
2131          */
2132         if (!(vma->vm_flags & VM_SHARED)) {
2133                 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2134                 return -EINVAL;
2135         }
2136         if (q->is_output) {
2137                 if (!(vma->vm_flags & VM_WRITE)) {
2138                         dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2139                         return -EINVAL;
2140                 }
2141         } else {
2142                 if (!(vma->vm_flags & VM_READ)) {
2143                         dprintk(1, "invalid vma flags, VM_READ needed\n");
2144                         return -EINVAL;
2145                 }
2146         }
2147
2148         mutex_lock(&q->mmap_lock);
2149
2150         if (vb2_fileio_is_active(q)) {
2151                 dprintk(1, "mmap: file io in progress\n");
2152                 ret = -EBUSY;
2153                 goto unlock;
2154         }
2155
2156         /*
2157          * Find the plane corresponding to the offset passed by userspace.
2158          */
2159         ret = __find_plane_by_offset(q, off, &buffer, &plane);
2160         if (ret)
2161                 goto unlock;
2162
2163         vb = q->bufs[buffer];
2164
2165         /*
2166          * MMAP requires page_aligned buffers.
2167          * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2168          * so, we need to do the same here.
2169          */
2170         length = PAGE_ALIGN(vb->planes[plane].length);
2171         if (length < (vma->vm_end - vma->vm_start)) {
2172                 dprintk(1,
2173                         "MMAP invalid, as it would overflow buffer length\n");
2174                 ret = -EINVAL;
2175                 goto unlock;
2176         }
2177
2178         ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2179
2180 unlock:
2181         mutex_unlock(&q->mmap_lock);
2182         if (ret)
2183                 return ret;
2184
2185         dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2186         return 0;
2187 }
2188 EXPORT_SYMBOL_GPL(vb2_mmap);
2189
2190 #ifndef CONFIG_MMU
2191 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2192                                     unsigned long addr,
2193                                     unsigned long len,
2194                                     unsigned long pgoff,
2195                                     unsigned long flags)
2196 {
2197         unsigned long off = pgoff << PAGE_SHIFT;
2198         struct vb2_buffer *vb;
2199         unsigned int buffer, plane;
2200         void *vaddr;
2201         int ret;
2202
2203         if (q->memory != VB2_MEMORY_MMAP) {
2204                 dprintk(1, "queue is not currently set up for mmap\n");
2205                 return -EINVAL;
2206         }
2207
2208         /*
2209          * Find the plane corresponding to the offset passed by userspace.
2210          */
2211         ret = __find_plane_by_offset(q, off, &buffer, &plane);
2212         if (ret)
2213                 return ret;
2214
2215         vb = q->bufs[buffer];
2216
2217         vaddr = vb2_plane_vaddr(vb, plane);
2218         return vaddr ? (unsigned long)vaddr : -EINVAL;
2219 }
2220 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2221 #endif
2222
2223 int vb2_core_queue_init(struct vb2_queue *q)
2224 {
2225         /*
2226          * Sanity check
2227          */
2228         if (WARN_ON(!q)                   ||
2229             WARN_ON(!q->ops)              ||
2230             WARN_ON(!q->mem_ops)          ||
2231             WARN_ON(!q->type)             ||
2232             WARN_ON(!q->io_modes)         ||
2233             WARN_ON(!q->ops->queue_setup) ||
2234             WARN_ON(!q->ops->buf_queue))
2235                 return -EINVAL;
2236
2237         INIT_LIST_HEAD(&q->queued_list);
2238         INIT_LIST_HEAD(&q->done_list);
2239         spin_lock_init(&q->done_lock);
2240         mutex_init(&q->mmap_lock);
2241         init_waitqueue_head(&q->done_wq);
2242
2243         q->memory = VB2_MEMORY_UNKNOWN;
2244
2245         if (q->buf_struct_size == 0)
2246                 q->buf_struct_size = sizeof(struct vb2_buffer);
2247
2248         if (q->bidirectional)
2249                 q->dma_dir = DMA_BIDIRECTIONAL;
2250         else
2251                 q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
2252
2253         return 0;
2254 }
2255 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2256
2257 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2258 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2259 void vb2_core_queue_release(struct vb2_queue *q)
2260 {
2261         __vb2_cleanup_fileio(q);
2262         __vb2_queue_cancel(q);
2263         mutex_lock(&q->mmap_lock);
2264         __vb2_queue_free(q, q->num_buffers);
2265         mutex_unlock(&q->mmap_lock);
2266 }
2267 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2268
2269 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
2270                 poll_table *wait)
2271 {
2272         __poll_t req_events = poll_requested_events(wait);
2273         struct vb2_buffer *vb = NULL;
2274         unsigned long flags;
2275
2276         if (!q->is_output && !(req_events & (EPOLLIN | EPOLLRDNORM)))
2277                 return 0;
2278         if (q->is_output && !(req_events & (EPOLLOUT | EPOLLWRNORM)))
2279                 return 0;
2280
2281         /*
2282          * Start file I/O emulator only if streaming API has not been used yet.
2283          */
2284         if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2285                 if (!q->is_output && (q->io_modes & VB2_READ) &&
2286                                 (req_events & (EPOLLIN | EPOLLRDNORM))) {
2287                         if (__vb2_init_fileio(q, 1))
2288                                 return EPOLLERR;
2289                 }
2290                 if (q->is_output && (q->io_modes & VB2_WRITE) &&
2291                                 (req_events & (EPOLLOUT | EPOLLWRNORM))) {
2292                         if (__vb2_init_fileio(q, 0))
2293                                 return EPOLLERR;
2294                         /*
2295                          * Write to OUTPUT queue can be done immediately.
2296                          */
2297                         return EPOLLOUT | EPOLLWRNORM;
2298                 }
2299         }
2300
2301         /*
2302          * There is nothing to wait for if the queue isn't streaming, or if the
2303          * error flag is set.
2304          */
2305         if (!vb2_is_streaming(q) || q->error)
2306                 return EPOLLERR;
2307
2308         /*
2309          * If this quirk is set and QBUF hasn't been called yet then
2310          * return EPOLLERR as well. This only affects capture queues, output
2311          * queues will always initialize waiting_for_buffers to false.
2312          * This quirk is set by V4L2 for backwards compatibility reasons.
2313          */
2314         if (q->quirk_poll_must_check_waiting_for_buffers &&
2315             q->waiting_for_buffers && (req_events & (EPOLLIN | EPOLLRDNORM)))
2316                 return EPOLLERR;
2317
2318         /*
2319          * For output streams you can call write() as long as there are fewer
2320          * buffers queued than there are buffers available.
2321          */
2322         if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2323                 return EPOLLOUT | EPOLLWRNORM;
2324
2325         if (list_empty(&q->done_list)) {
2326                 /*
2327                  * If the last buffer was dequeued from a capture queue,
2328                  * return immediately. DQBUF will return -EPIPE.
2329                  */
2330                 if (q->last_buffer_dequeued)
2331                         return EPOLLIN | EPOLLRDNORM;
2332
2333                 poll_wait(file, &q->done_wq, wait);
2334         }
2335
2336         /*
2337          * Take first buffer available for dequeuing.
2338          */
2339         spin_lock_irqsave(&q->done_lock, flags);
2340         if (!list_empty(&q->done_list))
2341                 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2342                                         done_entry);
2343         spin_unlock_irqrestore(&q->done_lock, flags);
2344
2345         if (vb && (vb->state == VB2_BUF_STATE_DONE
2346                         || vb->state == VB2_BUF_STATE_ERROR)) {
2347                 return (q->is_output) ?
2348                                 EPOLLOUT | EPOLLWRNORM :
2349                                 EPOLLIN | EPOLLRDNORM;
2350         }
2351         return 0;
2352 }
2353 EXPORT_SYMBOL_GPL(vb2_core_poll);
2354
2355 /*
2356  * struct vb2_fileio_buf - buffer context used by file io emulator
2357  *
2358  * vb2 provides a compatibility layer and emulator of file io (read and
2359  * write) calls on top of streaming API. This structure is used for
2360  * tracking context related to the buffers.
2361  */
2362 struct vb2_fileio_buf {
2363         void *vaddr;
2364         unsigned int size;
2365         unsigned int pos;
2366         unsigned int queued:1;
2367 };
2368
2369 /*
2370  * struct vb2_fileio_data - queue context used by file io emulator
2371  *
2372  * @cur_index:  the index of the buffer currently being read from or
2373  *              written to. If equal to q->num_buffers then a new buffer
2374  *              must be dequeued.
2375  * @initial_index: in the read() case all buffers are queued up immediately
2376  *              in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2377  *              buffers. However, in the write() case no buffers are initially
2378  *              queued, instead whenever a buffer is full it is queued up by
2379  *              __vb2_perform_fileio(). Only once all available buffers have
2380  *              been queued up will __vb2_perform_fileio() start to dequeue
2381  *              buffers. This means that initially __vb2_perform_fileio()
2382  *              needs to know what buffer index to use when it is queuing up
2383  *              the buffers for the first time. That initial index is stored
2384  *              in this field. Once it is equal to q->num_buffers all
2385  *              available buffers have been queued and __vb2_perform_fileio()
2386  *              should start the normal dequeue/queue cycle.
2387  *
2388  * vb2 provides a compatibility layer and emulator of file io (read and
2389  * write) calls on top of streaming API. For proper operation it required
2390  * this structure to save the driver state between each call of the read
2391  * or write function.
2392  */
2393 struct vb2_fileio_data {
2394         unsigned int count;
2395         unsigned int type;
2396         unsigned int memory;
2397         struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2398         unsigned int cur_index;
2399         unsigned int initial_index;
2400         unsigned int q_count;
2401         unsigned int dq_count;
2402         unsigned read_once:1;
2403         unsigned write_immediately:1;
2404 };
2405
2406 /*
2407  * __vb2_init_fileio() - initialize file io emulator
2408  * @q:          videobuf2 queue
2409  * @read:       mode selector (1 means read, 0 means write)
2410  */
2411 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2412 {
2413         struct vb2_fileio_data *fileio;
2414         int i, ret;
2415         unsigned int count = 0;
2416
2417         /*
2418          * Sanity check
2419          */
2420         if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2421                     (!read && !(q->io_modes & VB2_WRITE))))
2422                 return -EINVAL;
2423
2424         /*
2425          * Check if device supports mapping buffers to kernel virtual space.
2426          */
2427         if (!q->mem_ops->vaddr)
2428                 return -EBUSY;
2429
2430         /*
2431          * Check if streaming api has not been already activated.
2432          */
2433         if (q->streaming || q->num_buffers > 0)
2434                 return -EBUSY;
2435
2436         /*
2437          * Start with count 1, driver can increase it in queue_setup()
2438          */
2439         count = 1;
2440
2441         dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2442                 (read) ? "read" : "write", count, q->fileio_read_once,
2443                 q->fileio_write_immediately);
2444
2445         fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2446         if (fileio == NULL)
2447                 return -ENOMEM;
2448
2449         fileio->read_once = q->fileio_read_once;
2450         fileio->write_immediately = q->fileio_write_immediately;
2451
2452         /*
2453          * Request buffers and use MMAP type to force driver
2454          * to allocate buffers by itself.
2455          */
2456         fileio->count = count;
2457         fileio->memory = VB2_MEMORY_MMAP;
2458         fileio->type = q->type;
2459         q->fileio = fileio;
2460         ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2461         if (ret)
2462                 goto err_kfree;
2463
2464         /*
2465          * Check if plane_count is correct
2466          * (multiplane buffers are not supported).
2467          */
2468         if (q->bufs[0]->num_planes != 1) {
2469                 ret = -EBUSY;
2470                 goto err_reqbufs;
2471         }
2472
2473         /*
2474          * Get kernel address of each buffer.
2475          */
2476         for (i = 0; i < q->num_buffers; i++) {
2477                 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2478                 if (fileio->bufs[i].vaddr == NULL) {
2479                         ret = -EINVAL;
2480                         goto err_reqbufs;
2481                 }
2482                 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2483         }
2484
2485         /*
2486          * Read mode requires pre queuing of all buffers.
2487          */
2488         if (read) {
2489                 /*
2490                  * Queue all buffers.
2491                  */
2492                 for (i = 0; i < q->num_buffers; i++) {
2493                         ret = vb2_core_qbuf(q, i, NULL, NULL);
2494                         if (ret)
2495                                 goto err_reqbufs;
2496                         fileio->bufs[i].queued = 1;
2497                 }
2498                 /*
2499                  * All buffers have been queued, so mark that by setting
2500                  * initial_index to q->num_buffers
2501                  */
2502                 fileio->initial_index = q->num_buffers;
2503                 fileio->cur_index = q->num_buffers;
2504         }
2505
2506         /*
2507          * Start streaming.
2508          */
2509         ret = vb2_core_streamon(q, q->type);
2510         if (ret)
2511                 goto err_reqbufs;
2512
2513         return ret;
2514
2515 err_reqbufs:
2516         fileio->count = 0;
2517         vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2518
2519 err_kfree:
2520         q->fileio = NULL;
2521         kfree(fileio);
2522         return ret;
2523 }
2524
2525 /*
2526  * __vb2_cleanup_fileio() - free resourced used by file io emulator
2527  * @q:          videobuf2 queue
2528  */
2529 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2530 {
2531         struct vb2_fileio_data *fileio = q->fileio;
2532
2533         if (fileio) {
2534                 vb2_core_streamoff(q, q->type);
2535                 q->fileio = NULL;
2536                 fileio->count = 0;
2537                 vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2538                 kfree(fileio);
2539                 dprintk(3, "file io emulator closed\n");
2540         }
2541         return 0;
2542 }
2543
2544 /*
2545  * __vb2_perform_fileio() - perform a single file io (read or write) operation
2546  * @q:          videobuf2 queue
2547  * @data:       pointed to target userspace buffer
2548  * @count:      number of bytes to read or write
2549  * @ppos:       file handle position tracking pointer
2550  * @nonblock:   mode selector (1 means blocking calls, 0 means nonblocking)
2551  * @read:       access mode selector (1 means read, 0 means write)
2552  */
2553 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2554                 loff_t *ppos, int nonblock, int read)
2555 {
2556         struct vb2_fileio_data *fileio;
2557         struct vb2_fileio_buf *buf;
2558         bool is_multiplanar = q->is_multiplanar;
2559         /*
2560          * When using write() to write data to an output video node the vb2 core
2561          * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2562          * else is able to provide this information with the write() operation.
2563          */
2564         bool copy_timestamp = !read && q->copy_timestamp;
2565         unsigned index;
2566         int ret;
2567
2568         dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2569                 read ? "read" : "write", (long)*ppos, count,
2570                 nonblock ? "non" : "");
2571
2572         if (!data)
2573                 return -EINVAL;
2574
2575         /*
2576          * Initialize emulator on first call.
2577          */
2578         if (!vb2_fileio_is_active(q)) {
2579                 ret = __vb2_init_fileio(q, read);
2580                 dprintk(3, "vb2_init_fileio result: %d\n", ret);
2581                 if (ret)
2582                         return ret;
2583         }
2584         fileio = q->fileio;
2585
2586         /*
2587          * Check if we need to dequeue the buffer.
2588          */
2589         index = fileio->cur_index;
2590         if (index >= q->num_buffers) {
2591                 struct vb2_buffer *b;
2592
2593                 /*
2594                  * Call vb2_dqbuf to get buffer back.
2595                  */
2596                 ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2597                 dprintk(5, "vb2_dqbuf result: %d\n", ret);
2598                 if (ret)
2599                         return ret;
2600                 fileio->dq_count += 1;
2601
2602                 fileio->cur_index = index;
2603                 buf = &fileio->bufs[index];
2604                 b = q->bufs[index];
2605
2606                 /*
2607                  * Get number of bytes filled by the driver
2608                  */
2609                 buf->pos = 0;
2610                 buf->queued = 0;
2611                 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2612                                  : vb2_plane_size(q->bufs[index], 0);
2613                 /* Compensate for data_offset on read in the multiplanar case. */
2614                 if (is_multiplanar && read &&
2615                                 b->planes[0].data_offset < buf->size) {
2616                         buf->pos = b->planes[0].data_offset;
2617                         buf->size -= buf->pos;
2618                 }
2619         } else {
2620                 buf = &fileio->bufs[index];
2621         }
2622
2623         /*
2624          * Limit count on last few bytes of the buffer.
2625          */
2626         if (buf->pos + count > buf->size) {
2627                 count = buf->size - buf->pos;
2628                 dprintk(5, "reducing read count: %zd\n", count);
2629         }
2630
2631         /*
2632          * Transfer data to userspace.
2633          */
2634         dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
2635                 count, index, buf->pos);
2636         if (read)
2637                 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2638         else
2639                 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2640         if (ret) {
2641                 dprintk(3, "error copying data\n");
2642                 return -EFAULT;
2643         }
2644
2645         /*
2646          * Update counters.
2647          */
2648         buf->pos += count;
2649         *ppos += count;
2650
2651         /*
2652          * Queue next buffer if required.
2653          */
2654         if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2655                 struct vb2_buffer *b = q->bufs[index];
2656
2657                 /*
2658                  * Check if this is the last buffer to read.
2659                  */
2660                 if (read && fileio->read_once && fileio->dq_count == 1) {
2661                         dprintk(3, "read limit reached\n");
2662                         return __vb2_cleanup_fileio(q);
2663                 }
2664
2665                 /*
2666                  * Call vb2_qbuf and give buffer to the driver.
2667                  */
2668                 b->planes[0].bytesused = buf->pos;
2669
2670                 if (copy_timestamp)
2671                         b->timestamp = ktime_get_ns();
2672                 ret = vb2_core_qbuf(q, index, NULL, NULL);
2673                 dprintk(5, "vb2_dbuf result: %d\n", ret);
2674                 if (ret)
2675                         return ret;
2676
2677                 /*
2678                  * Buffer has been queued, update the status
2679                  */
2680                 buf->pos = 0;
2681                 buf->queued = 1;
2682                 buf->size = vb2_plane_size(q->bufs[index], 0);
2683                 fileio->q_count += 1;
2684                 /*
2685                  * If we are queuing up buffers for the first time, then
2686                  * increase initial_index by one.
2687                  */
2688                 if (fileio->initial_index < q->num_buffers)
2689                         fileio->initial_index++;
2690                 /*
2691                  * The next buffer to use is either a buffer that's going to be
2692                  * queued for the first time (initial_index < q->num_buffers)
2693                  * or it is equal to q->num_buffers, meaning that the next
2694                  * time we need to dequeue a buffer since we've now queued up
2695                  * all the 'first time' buffers.
2696                  */
2697                 fileio->cur_index = fileio->initial_index;
2698         }
2699
2700         /*
2701          * Return proper number of bytes processed.
2702          */
2703         if (ret == 0)
2704                 ret = count;
2705         return ret;
2706 }
2707
2708 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2709                 loff_t *ppos, int nonblocking)
2710 {
2711         return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2712 }
2713 EXPORT_SYMBOL_GPL(vb2_read);
2714
2715 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2716                 loff_t *ppos, int nonblocking)
2717 {
2718         return __vb2_perform_fileio(q, (char __user *) data, count,
2719                                                         ppos, nonblocking, 0);
2720 }
2721 EXPORT_SYMBOL_GPL(vb2_write);
2722
2723 struct vb2_threadio_data {
2724         struct task_struct *thread;
2725         vb2_thread_fnc fnc;
2726         void *priv;
2727         bool stop;
2728 };
2729
2730 static int vb2_thread(void *data)
2731 {
2732         struct vb2_queue *q = data;
2733         struct vb2_threadio_data *threadio = q->threadio;
2734         bool copy_timestamp = false;
2735         unsigned prequeue = 0;
2736         unsigned index = 0;
2737         int ret = 0;
2738
2739         if (q->is_output) {
2740                 prequeue = q->num_buffers;
2741                 copy_timestamp = q->copy_timestamp;
2742         }
2743
2744         set_freezable();
2745
2746         for (;;) {
2747                 struct vb2_buffer *vb;
2748
2749                 /*
2750                  * Call vb2_dqbuf to get buffer back.
2751                  */
2752                 if (prequeue) {
2753                         vb = q->bufs[index++];
2754                         prequeue--;
2755                 } else {
2756                         call_void_qop(q, wait_finish, q);
2757                         if (!threadio->stop)
2758                                 ret = vb2_core_dqbuf(q, &index, NULL, 0);
2759                         call_void_qop(q, wait_prepare, q);
2760                         dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
2761                         if (!ret)
2762                                 vb = q->bufs[index];
2763                 }
2764                 if (ret || threadio->stop)
2765                         break;
2766                 try_to_freeze();
2767
2768                 if (vb->state != VB2_BUF_STATE_ERROR)
2769                         if (threadio->fnc(vb, threadio->priv))
2770                                 break;
2771                 call_void_qop(q, wait_finish, q);
2772                 if (copy_timestamp)
2773                         vb->timestamp = ktime_get_ns();
2774                 if (!threadio->stop)
2775                         ret = vb2_core_qbuf(q, vb->index, NULL, NULL);
2776                 call_void_qop(q, wait_prepare, q);
2777                 if (ret || threadio->stop)
2778                         break;
2779         }
2780
2781         /* Hmm, linux becomes *very* unhappy without this ... */
2782         while (!kthread_should_stop()) {
2783                 set_current_state(TASK_INTERRUPTIBLE);
2784                 schedule();
2785         }
2786         return 0;
2787 }
2788
2789 /*
2790  * This function should not be used for anything else but the videobuf2-dvb
2791  * support. If you think you have another good use-case for this, then please
2792  * contact the linux-media mailinglist first.
2793  */
2794 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
2795                      const char *thread_name)
2796 {
2797         struct vb2_threadio_data *threadio;
2798         int ret = 0;
2799
2800         if (q->threadio)
2801                 return -EBUSY;
2802         if (vb2_is_busy(q))
2803                 return -EBUSY;
2804         if (WARN_ON(q->fileio))
2805                 return -EBUSY;
2806
2807         threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
2808         if (threadio == NULL)
2809                 return -ENOMEM;
2810         threadio->fnc = fnc;
2811         threadio->priv = priv;
2812
2813         ret = __vb2_init_fileio(q, !q->is_output);
2814         dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
2815         if (ret)
2816                 goto nomem;
2817         q->threadio = threadio;
2818         threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
2819         if (IS_ERR(threadio->thread)) {
2820                 ret = PTR_ERR(threadio->thread);
2821                 threadio->thread = NULL;
2822                 goto nothread;
2823         }
2824         return 0;
2825
2826 nothread:
2827         __vb2_cleanup_fileio(q);
2828 nomem:
2829         kfree(threadio);
2830         return ret;
2831 }
2832 EXPORT_SYMBOL_GPL(vb2_thread_start);
2833
2834 int vb2_thread_stop(struct vb2_queue *q)
2835 {
2836         struct vb2_threadio_data *threadio = q->threadio;
2837         int err;
2838
2839         if (threadio == NULL)
2840                 return 0;
2841         threadio->stop = true;
2842         /* Wake up all pending sleeps in the thread */
2843         vb2_queue_error(q);
2844         err = kthread_stop(threadio->thread);
2845         __vb2_cleanup_fileio(q);
2846         threadio->thread = NULL;
2847         kfree(threadio);
2848         q->threadio = NULL;
2849         return err;
2850 }
2851 EXPORT_SYMBOL_GPL(vb2_thread_stop);
2852
2853 MODULE_DESCRIPTION("Media buffer core framework");
2854 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2855 MODULE_LICENSE("GPL");