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