drivers/media/v4l2-core/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 #include <linux/err.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/mm.h>
  21 #include <linux/poll.h>
  22 #include <linux/slab.h>
  23 #include <linux/sched.h>
  24 #include <linux/freezer.h>
  25 #include <linux/kthread.h>
  26
  27 #include <media/videobuf2-core.h>
  28 #include <media/v4l2-mc.h>
  29
  30 #include <trace/events/vb2.h>
  31
  32 static int debug;
  33 module_param(debug, int, 0644);
  34
  35 #define dprintk(level, fmt, arg...)                                           \
  36         do {                                                                  \
  37                 if (debug >= level)                                           \
  38                         pr_info("vb2-core: %s: " fmt, __func__, ## arg); \
  39         } while (0)
  40
  41 #ifdef CONFIG_VIDEO_ADV_DEBUG
  42
  43 /*
  44  * If advanced debugging is on, then count how often each op is called
  45  * successfully, which can either be per-buffer or per-queue.
  46  *
  47  * This makes it easy to check that the 'init' and 'cleanup'
  48  * (and variations thereof) stay balanced.
  49  */
  50
  51 #define log_memop(vb, op)                                               \
  52         dprintk(2, "call_memop(%p, %d, %s)%s\n",                        \
  53                 (vb)->vb2_queue, (vb)->index, #op,                      \
  54                 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
  55
  56 #define call_memop(vb, op, args...)                                     \
  57 ({                                                                      \
  58         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  59         int err;                                                        \
  60                                                                         \
  61         log_memop(vb, op);                                              \
  62         err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0;              \
  63         if (!err)                                                       \
  64                 (vb)->cnt_mem_ ## op++;                                 \
  65         err;                                                            \
  66 })
  67
  68 #define call_ptr_memop(vb, op, args...)                                 \
  69 ({                                                                      \
  70         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  71         void *ptr;                                                      \
  72                                                                         \
  73         log_memop(vb, op);                                              \
  74         ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL;           \
  75         if (!IS_ERR_OR_NULL(ptr))                                       \
  76                 (vb)->cnt_mem_ ## op++;                                 \
  77         ptr;                                                            \
  78 })
  79
  80 #define call_void_memop(vb, op, args...)                                \
  81 ({                                                                      \
  82         struct vb2_queue *_q = (vb)->vb2_queue;                         \
  83                                                                         \
  84         log_memop(vb, op);                                              \
  85         if (_q->mem_ops->op)                                            \
  86                 _q->mem_ops->op(args);                                  \
  87         (vb)->cnt_mem_ ## op++;                                         \
  88 })
  89
  90 #define log_qop(q, op)                                                  \
  91         dprintk(2, "call_qop(%p, %s)%s\n", q, #op,                      \
  92                 (q)->ops->op ? "" : " (nop)")
  93
  94 #define call_qop(q, op, args...)                                        \
  95 ({                                                                      \
  96         int err;                                                        \
  97                                                                         \
  98         log_qop(q, op);                                                 \
  99         err = (q)->ops->op ? (q)->ops->op(args) : 0;                    \
 100         if (!err)                                                       \
 101                 (q)->cnt_ ## op++;                                      \
 102         err;                                                            \
 103 })
 104
 105 #define call_void_qop(q, op, args...)                                   \
 106 ({                                                                      \
 107         log_qop(q, op);                                                 \
 108         if ((q)->ops->op)                                               \
 109                 (q)->ops->op(args);                                     \
 110         (q)->cnt_ ## op++;                                              \
 111 })
 112
 113 #define log_vb_qop(vb, op, args...)                                     \
 114         dprintk(2, "call_vb_qop(%p, %d, %s)%s\n",                       \
 115                 (vb)->vb2_queue, (vb)->index, #op,                      \
 116                 (vb)->vb2_queue->ops->op ? "" : " (nop)")
 117
 118 #define call_vb_qop(vb, op, args...)                                    \
 119 ({                                                                      \
 120         int err;                                                        \
 121                                                                         \
 122         log_vb_qop(vb, op);                                             \
 123         err = (vb)->vb2_queue->ops->op ?                                \
 124                 (vb)->vb2_queue->ops->op(args) : 0;                     \
 125         if (!err)                                                       \
 126                 (vb)->cnt_ ## op++;                                     \
 127         err;                                                            \
 128 })
 129
 130 #define call_void_vb_qop(vb, op, args...)                               \
 131 ({                                                                      \
 132         log_vb_qop(vb, op);                                             \
 133         if ((vb)->vb2_queue->ops->op)                                   \
 134                 (vb)->vb2_queue->ops->op(args);                         \
 135         (vb)->cnt_ ## op++;                                             \
 136 })
 137
 138 #else
 139
 140 #define call_memop(vb, op, args...)                                     \
 141         ((vb)->vb2_queue->mem_ops->op ?                                 \
 142                 (vb)->vb2_queue->mem_ops->op(args) : 0)
 143
 144 #define call_ptr_memop(vb, op, args...)                                 \
 145         ((vb)->vb2_queue->mem_ops->op ?                                 \
 146                 (vb)->vb2_queue->mem_ops->op(args) : NULL)
 147
 148 #define call_void_memop(vb, op, args...)                                \
 149         do {                                                            \
 150                 if ((vb)->vb2_queue->mem_ops->op)                       \
 151                         (vb)->vb2_queue->mem_ops->op(args);             \
 152         } while (0)
 153
 154 #define call_qop(q, op, args...)                                        \
 155         ((q)->ops->op ? (q)->ops->op(args) : 0)
 156
 157 #define call_void_qop(q, op, args...)                                   \
 158         do {                                                            \
 159                 if ((q)->ops->op)                                       \
 160                         (q)->ops->op(args);                             \
 161         } while (0)
 162
 163 #define call_vb_qop(vb, op, args...)                                    \
 164         ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
 165
 166 #define call_void_vb_qop(vb, op, args...)                               \
 167         do {                                                            \
 168                 if ((vb)->vb2_queue->ops->op)                           \
 169                         (vb)->vb2_queue->ops->op(args);                 \
 170         } while (0)
 171
 172 #endif
 173
 174 #define call_bufop(q, op, args...)                                      \
 175 ({                                                                      \
 176         int ret = 0;                                                    \
 177         if (q && q->buf_ops && q->buf_ops->op)                          \
 178                 ret = q->buf_ops->op(args);                             \
 179         ret;                                                            \
 180 })
 181
 182 #define call_void_bufop(q, op, args...)                                 \
 183 ({                                                                      \
 184         if (q && q->buf_ops && q->buf_ops->op)                          \
 185                 q->buf_ops->op(args);                                   \
 186 })
 187
 188 static void __vb2_queue_cancel(struct vb2_queue *q);
 189 static void __enqueue_in_driver(struct vb2_buffer *vb);
 190
 191 /**
 192  * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
 193  */
 194 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
 195 {
 196         struct vb2_queue *q = vb->vb2_queue;
 197         enum dma_data_direction dma_dir =
 198                 q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
 199         void *mem_priv;
 200         int plane;
 201         int ret = -ENOMEM;
 202
 203         /*
 204          * Allocate memory for all planes in this buffer
 205          * NOTE: mmapped areas should be page aligned
 206          */
 207         for (plane = 0; plane < vb->num_planes; ++plane) {
 208                 unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
 209
 210                 mem_priv = call_ptr_memop(vb, alloc,
 211                                 q->alloc_devs[plane] ? : q->dev,
 212                                 q->dma_attrs, size, dma_dir, q->gfp_flags);
 213                 if (IS_ERR(mem_priv)) {
 214                         if (mem_priv)
 215                                 ret = PTR_ERR(mem_priv);
 216                         goto free;
 217                 }
 218
 219                 /* Associate allocator private data with this plane */
 220                 vb->planes[plane].mem_priv = mem_priv;
 221         }
 222
 223         return 0;
 224 free:
 225         /* Free already allocated memory if one of the allocations failed */
 226         for (; plane > 0; --plane) {
 227                 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
 228                 vb->planes[plane - 1].mem_priv = NULL;
 229         }
 230
 231         return ret;
 232 }
 233
 234 /**
 235  * __vb2_buf_mem_free() - free memory of the given buffer
 236  */
 237 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
 238 {
 239         unsigned int plane;
 240
 241         for (plane = 0; plane < vb->num_planes; ++plane) {
 242                 call_void_memop(vb, put, vb->planes[plane].mem_priv);
 243                 vb->planes[plane].mem_priv = NULL;
 244                 dprintk(3, "freed plane %d of buffer %d\n", plane, vb->index);
 245         }
 246 }
 247
 248 /**
 249  * __vb2_buf_userptr_put() - release userspace memory associated with
 250  * a USERPTR buffer
 251  */
 252 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
 253 {
 254         unsigned int plane;
 255
 256         for (plane = 0; plane < vb->num_planes; ++plane) {
 257                 if (vb->planes[plane].mem_priv)
 258                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
 259                 vb->planes[plane].mem_priv = NULL;
 260         }
 261 }
 262
 263 /**
 264  * __vb2_plane_dmabuf_put() - release memory associated with
 265  * a DMABUF shared plane
 266  */
 267 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
 268 {
 269         if (!p->mem_priv)
 270                 return;
 271
 272         if (p->dbuf_mapped)
 273                 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
 274
 275         call_void_memop(vb, detach_dmabuf, p->mem_priv);
 276         dma_buf_put(p->dbuf);
 277         p->mem_priv = NULL;
 278         p->dbuf = NULL;
 279         p->dbuf_mapped = 0;
 280 }
 281
 282 /**
 283  * __vb2_buf_dmabuf_put() - release memory associated with
 284  * a DMABUF shared buffer
 285  */
 286 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
 287 {
 288         unsigned int plane;
 289
 290         for (plane = 0; plane < vb->num_planes; ++plane)
 291                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
 292 }
 293
 294 /**
 295  * __setup_offsets() - setup unique offsets ("cookies") for every plane in
 296  * the buffer.
 297  */
 298 static void __setup_offsets(struct vb2_buffer *vb)
 299 {
 300         struct vb2_queue *q = vb->vb2_queue;
 301         unsigned int plane;
 302         unsigned long off = 0;
 303
 304         if (vb->index) {
 305                 struct vb2_buffer *prev = q->bufs[vb->index - 1];
 306                 struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
 307
 308                 off = PAGE_ALIGN(p->m.offset + p->length);
 309         }
 310
 311         for (plane = 0; plane < vb->num_planes; ++plane) {
 312                 vb->planes[plane].m.offset = off;
 313
 314                 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
 315                                 vb->index, plane, off);
 316
 317                 off += vb->planes[plane].length;
 318                 off = PAGE_ALIGN(off);
 319         }
 320 }
 321
 322 /**
 323  * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
 324  * video buffer memory for all buffers/planes on the queue and initializes the
 325  * queue
 326  *
 327  * Returns the number of buffers successfully allocated.
 328  */
 329 static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
 330                              unsigned int num_buffers, unsigned int num_planes,
 331                              const unsigned plane_sizes[VB2_MAX_PLANES])
 332 {
 333         unsigned int buffer, plane;
 334         struct vb2_buffer *vb;
 335         int ret;
 336
 337         /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
 338         num_buffers = min_t(unsigned int, num_buffers,
 339                             VB2_MAX_FRAME - q->num_buffers);
 340
 341         for (buffer = 0; buffer < num_buffers; ++buffer) {
 342                 /* Allocate videobuf buffer structures */
 343                 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
 344                 if (!vb) {
 345                         dprintk(1, "memory alloc for buffer struct failed\n");
 346                         break;
 347                 }
 348
 349                 vb->state = VB2_BUF_STATE_DEQUEUED;
 350                 vb->vb2_queue = q;
 351                 vb->num_planes = num_planes;
 352                 vb->index = q->num_buffers + buffer;
 353                 vb->type = q->type;
 354                 vb->memory = memory;
 355                 for (plane = 0; plane < num_planes; ++plane) {
 356                         vb->planes[plane].length = plane_sizes[plane];
 357                         vb->planes[plane].min_length = plane_sizes[plane];
 358                 }
 359                 q->bufs[vb->index] = vb;
 360
 361                 /* Allocate video buffer memory for the MMAP type */
 362                 if (memory == VB2_MEMORY_MMAP) {
 363                         ret = __vb2_buf_mem_alloc(vb);
 364                         if (ret) {
 365                                 dprintk(1, "failed allocating memory for "
 366                                                 "buffer %d\n", buffer);
 367                                 q->bufs[vb->index] = NULL;
 368                                 kfree(vb);
 369                                 break;
 370                         }
 371                         __setup_offsets(vb);
 372                         /*
 373                          * Call the driver-provided buffer initialization
 374                          * callback, if given. An error in initialization
 375                          * results in queue setup failure.
 376                          */
 377                         ret = call_vb_qop(vb, buf_init, vb);
 378                         if (ret) {
 379                                 dprintk(1, "buffer %d %p initialization"
 380                                         " failed\n", buffer, vb);
 381                                 __vb2_buf_mem_free(vb);
 382                                 q->bufs[vb->index] = NULL;
 383                                 kfree(vb);
 384                                 break;
 385                         }
 386                 }
 387         }
 388
 389         dprintk(1, "allocated %d buffers, %d plane(s) each\n",
 390                         buffer, num_planes);
 391
 392         return buffer;
 393 }
 394
 395 /**
 396  * __vb2_free_mem() - release all video buffer memory for a given queue
 397  */
 398 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
 399 {
 400         unsigned int buffer;
 401         struct vb2_buffer *vb;
 402
 403         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 404              ++buffer) {
 405                 vb = q->bufs[buffer];
 406                 if (!vb)
 407                         continue;
 408
 409                 /* Free MMAP buffers or release USERPTR buffers */
 410                 if (q->memory == VB2_MEMORY_MMAP)
 411                         __vb2_buf_mem_free(vb);
 412                 else if (q->memory == VB2_MEMORY_DMABUF)
 413                         __vb2_buf_dmabuf_put(vb);
 414                 else
 415                         __vb2_buf_userptr_put(vb);
 416         }
 417 }
 418
 419 /**
 420  * __vb2_queue_free() - free buffers at the end of the queue - video memory and
 421  * related information, if no buffers are left return the queue to an
 422  * uninitialized state. Might be called even if the queue has already been freed.
 423  */
 424 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
 425 {
 426         unsigned int buffer;
 427
 428         /*
 429          * Sanity check: when preparing a buffer the queue lock is released for
 430          * a short while (see __buf_prepare for the details), which would allow
 431          * a race with a reqbufs which can call this function. Removing the
 432          * buffers from underneath __buf_prepare is obviously a bad idea, so we
 433          * check if any of the buffers is in the state PREPARING, and if so we
 434          * just return -EAGAIN.
 435          */
 436         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 437              ++buffer) {
 438                 if (q->bufs[buffer] == NULL)
 439                         continue;
 440                 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
 441                         dprintk(1, "preparing buffers, cannot free\n");
 442                         return -EAGAIN;
 443                 }
 444         }
 445
 446         /* Call driver-provided cleanup function for each buffer, if provided */
 447         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 448              ++buffer) {
 449                 struct vb2_buffer *vb = q->bufs[buffer];
 450
 451                 if (vb && vb->planes[0].mem_priv)
 452                         call_void_vb_qop(vb, buf_cleanup, vb);
 453         }
 454
 455         /* Release video buffer memory */
 456         __vb2_free_mem(q, buffers);
 457
 458 #ifdef CONFIG_VIDEO_ADV_DEBUG
 459         /*
 460          * Check that all the calls were balances during the life-time of this
 461          * queue. If not (or if the debug level is 1 or up), then dump the
 462          * counters to the kernel log.
 463          */
 464         if (q->num_buffers) {
 465                 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
 466                                   q->cnt_wait_prepare != q->cnt_wait_finish;
 467
 468                 if (unbalanced || debug) {
 469                         pr_info("vb2: counters for queue %p:%s\n", q,
 470                                 unbalanced ? " UNBALANCED!" : "");
 471                         pr_info("vb2:     setup: %u start_streaming: %u stop_streaming: %u\n",
 472                                 q->cnt_queue_setup, q->cnt_start_streaming,
 473                                 q->cnt_stop_streaming);
 474                         pr_info("vb2:     wait_prepare: %u wait_finish: %u\n",
 475                                 q->cnt_wait_prepare, q->cnt_wait_finish);
 476                 }
 477                 q->cnt_queue_setup = 0;
 478                 q->cnt_wait_prepare = 0;
 479                 q->cnt_wait_finish = 0;
 480                 q->cnt_start_streaming = 0;
 481                 q->cnt_stop_streaming = 0;
 482         }
 483         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 484                 struct vb2_buffer *vb = q->bufs[buffer];
 485                 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
 486                                   vb->cnt_mem_prepare != vb->cnt_mem_finish ||
 487                                   vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
 488                                   vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
 489                                   vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
 490                                   vb->cnt_buf_queue != vb->cnt_buf_done ||
 491                                   vb->cnt_buf_prepare != vb->cnt_buf_finish ||
 492                                   vb->cnt_buf_init != vb->cnt_buf_cleanup;
 493
 494                 if (unbalanced || debug) {
 495                         pr_info("vb2:   counters for queue %p, buffer %d:%s\n",
 496                                 q, buffer, unbalanced ? " UNBALANCED!" : "");
 497                         pr_info("vb2:     buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
 498                                 vb->cnt_buf_init, vb->cnt_buf_cleanup,
 499                                 vb->cnt_buf_prepare, vb->cnt_buf_finish);
 500                         pr_info("vb2:     buf_queue: %u buf_done: %u\n",
 501                                 vb->cnt_buf_queue, vb->cnt_buf_done);
 502                         pr_info("vb2:     alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
 503                                 vb->cnt_mem_alloc, vb->cnt_mem_put,
 504                                 vb->cnt_mem_prepare, vb->cnt_mem_finish,
 505                                 vb->cnt_mem_mmap);
 506                         pr_info("vb2:     get_userptr: %u put_userptr: %u\n",
 507                                 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
 508                         pr_info("vb2:     attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
 509                                 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
 510                                 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
 511                         pr_info("vb2:     get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
 512                                 vb->cnt_mem_get_dmabuf,
 513                                 vb->cnt_mem_num_users,
 514                                 vb->cnt_mem_vaddr,
 515                                 vb->cnt_mem_cookie);
 516                 }
 517         }
 518 #endif
 519
 520         /* Free videobuf buffers */
 521         for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
 522              ++buffer) {
 523                 kfree(q->bufs[buffer]);
 524                 q->bufs[buffer] = NULL;
 525         }
 526
 527         q->num_buffers -= buffers;
 528         if (!q->num_buffers) {
 529                 q->memory = 0;
 530                 INIT_LIST_HEAD(&q->queued_list);
 531         }
 532         return 0;
 533 }
 534
 535 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
 536 {
 537         unsigned int plane;
 538         for (plane = 0; plane < vb->num_planes; ++plane) {
 539                 void *mem_priv = vb->planes[plane].mem_priv;
 540                 /*
 541                  * If num_users() has not been provided, call_memop
 542                  * will return 0, apparently nobody cares about this
 543                  * case anyway. If num_users() returns more than 1,
 544                  * we are not the only user of the plane's memory.
 545                  */
 546                 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
 547                         return true;
 548         }
 549         return false;
 550 }
 551 EXPORT_SYMBOL(vb2_buffer_in_use);
 552
 553 /**
 554  * __buffers_in_use() - return true if any buffers on the queue are in use and
 555  * the queue cannot be freed (by the means of REQBUFS(0)) call
 556  */
 557 static bool __buffers_in_use(struct vb2_queue *q)
 558 {
 559         unsigned int buffer;
 560         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
 561                 if (vb2_buffer_in_use(q, q->bufs[buffer]))
 562                         return true;
 563         }
 564         return false;
 565 }
 566
 567 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
 568 {
 569         call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
 570 }
 571 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
 572
 573 /**
 574  * __verify_userptr_ops() - verify that all memory operations required for
 575  * USERPTR queue type have been provided
 576  */
 577 static int __verify_userptr_ops(struct vb2_queue *q)
 578 {
 579         if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
 580             !q->mem_ops->put_userptr)
 581                 return -EINVAL;
 582
 583         return 0;
 584 }
 585
 586 /**
 587  * __verify_mmap_ops() - verify that all memory operations required for
 588  * MMAP queue type have been provided
 589  */
 590 static int __verify_mmap_ops(struct vb2_queue *q)
 591 {
 592         if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
 593             !q->mem_ops->put || !q->mem_ops->mmap)
 594                 return -EINVAL;
 595
 596         return 0;
 597 }
 598
 599 /**
 600  * __verify_dmabuf_ops() - verify that all memory operations required for
 601  * DMABUF queue type have been provided
 602  */
 603 static int __verify_dmabuf_ops(struct vb2_queue *q)
 604 {
 605         if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
 606             !q->mem_ops->detach_dmabuf  || !q->mem_ops->map_dmabuf ||
 607             !q->mem_ops->unmap_dmabuf)
 608                 return -EINVAL;
 609
 610         return 0;
 611 }
 612
 613 int vb2_verify_memory_type(struct vb2_queue *q,
 614                 enum vb2_memory memory, unsigned int type)
 615 {
 616         if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
 617             memory != VB2_MEMORY_DMABUF) {
 618                 dprintk(1, "unsupported memory type\n");
 619                 return -EINVAL;
 620         }
 621
 622         if (type != q->type) {
 623                 dprintk(1, "requested type is incorrect\n");
 624                 return -EINVAL;
 625         }
 626
 627         /*
 628          * Make sure all the required memory ops for given memory type
 629          * are available.
 630          */
 631         if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
 632                 dprintk(1, "MMAP for current setup unsupported\n");
 633                 return -EINVAL;
 634         }
 635
 636         if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
 637                 dprintk(1, "USERPTR for current setup unsupported\n");
 638                 return -EINVAL;
 639         }
 640
 641         if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
 642                 dprintk(1, "DMABUF for current setup unsupported\n");
 643                 return -EINVAL;
 644         }
 645
 646         /*
 647          * Place the busy tests at the end: -EBUSY can be ignored when
 648          * create_bufs is called with count == 0, but count == 0 should still
 649          * do the memory and type validation.
 650          */
 651         if (vb2_fileio_is_active(q)) {
 652                 dprintk(1, "file io in progress\n");
 653                 return -EBUSY;
 654         }
 655         return 0;
 656 }
 657 EXPORT_SYMBOL(vb2_verify_memory_type);
 658
 659 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 660                 unsigned int *count)
 661 {
 662         unsigned int num_buffers, allocated_buffers, num_planes = 0;
 663         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 664         int ret;
 665
 666         if (q->streaming) {
 667                 dprintk(1, "streaming active\n");
 668                 return -EBUSY;
 669         }
 670
 671         if (*count == 0 || q->num_buffers != 0 || q->memory != memory) {
 672                 /*
 673                  * We already have buffers allocated, so first check if they
 674                  * are not in use and can be freed.
 675                  */
 676                 mutex_lock(&q->mmap_lock);
 677                 if (q->memory == VB2_MEMORY_MMAP && __buffers_in_use(q)) {
 678                         mutex_unlock(&q->mmap_lock);
 679                         dprintk(1, "memory in use, cannot free\n");
 680                         return -EBUSY;
 681                 }
 682
 683                 /*
 684                  * Call queue_cancel to clean up any buffers in the PREPARED or
 685                  * QUEUED state which is possible if buffers were prepared or
 686                  * queued without ever calling STREAMON.
 687                  */
 688                 __vb2_queue_cancel(q);
 689                 ret = __vb2_queue_free(q, q->num_buffers);
 690                 mutex_unlock(&q->mmap_lock);
 691                 if (ret)
 692                         return ret;
 693
 694                 /*
 695                  * In case of REQBUFS(0) return immediately without calling
 696                  * driver's queue_setup() callback and allocating resources.
 697                  */
 698                 if (*count == 0)
 699                         return 0;
 700         }
 701
 702         /*
 703          * Make sure the requested values and current defaults are sane.
 704          */
 705         num_buffers = min_t(unsigned int, *count, VB2_MAX_FRAME);
 706         num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
 707         memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 708         q->memory = memory;
 709
 710         /*
 711          * Ask the driver how many buffers and planes per buffer it requires.
 712          * Driver also sets the size and allocator context for each plane.
 713          */
 714         ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
 715                        plane_sizes, q->alloc_devs);
 716         if (ret)
 717                 return ret;
 718
 719         /* Finally, allocate buffers and video memory */
 720         allocated_buffers =
 721                 __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
 722         if (allocated_buffers == 0) {
 723                 dprintk(1, "memory allocation failed\n");
 724                 return -ENOMEM;
 725         }
 726
 727         /*
 728          * There is no point in continuing if we can't allocate the minimum
 729          * number of buffers needed by this vb2_queue.
 730          */
 731         if (allocated_buffers < q->min_buffers_needed)
 732                 ret = -ENOMEM;
 733
 734         /*
 735          * Check if driver can handle the allocated number of buffers.
 736          */
 737         if (!ret && allocated_buffers < num_buffers) {
 738                 num_buffers = allocated_buffers;
 739                 /*
 740                  * num_planes is set by the previous queue_setup(), but since it
 741                  * signals to queue_setup() whether it is called from create_bufs()
 742                  * vs reqbufs() we zero it here to signal that queue_setup() is
 743                  * called for the reqbufs() case.
 744                  */
 745                 num_planes = 0;
 746
 747                 ret = call_qop(q, queue_setup, q, &num_buffers,
 748                                &num_planes, plane_sizes, q->alloc_devs);
 749
 750                 if (!ret && allocated_buffers < num_buffers)
 751                         ret = -ENOMEM;
 752
 753                 /*
 754                  * Either the driver has accepted a smaller number of buffers,
 755                  * or .queue_setup() returned an error
 756                  */
 757         }
 758
 759         mutex_lock(&q->mmap_lock);
 760         q->num_buffers = allocated_buffers;
 761
 762         if (ret < 0) {
 763                 /*
 764                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 765                  * from q->num_buffers.
 766                  */
 767                 __vb2_queue_free(q, allocated_buffers);
 768                 mutex_unlock(&q->mmap_lock);
 769                 return ret;
 770         }
 771         mutex_unlock(&q->mmap_lock);
 772
 773         /*
 774          * Return the number of successfully allocated buffers
 775          * to the userspace.
 776          */
 777         *count = allocated_buffers;
 778         q->waiting_for_buffers = !q->is_output;
 779
 780         return 0;
 781 }
 782 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
 783
 784 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 785                 unsigned int *count, unsigned requested_planes,
 786                 const unsigned requested_sizes[])
 787 {
 788         unsigned int num_planes = 0, num_buffers, allocated_buffers;
 789         unsigned plane_sizes[VB2_MAX_PLANES] = { };
 790         int ret;
 791
 792         if (q->num_buffers == VB2_MAX_FRAME) {
 793                 dprintk(1, "maximum number of buffers already allocated\n");
 794                 return -ENOBUFS;
 795         }
 796
 797         if (!q->num_buffers) {
 798                 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
 799                 q->memory = memory;
 800                 q->waiting_for_buffers = !q->is_output;
 801         }
 802
 803         num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
 804
 805         if (requested_planes && requested_sizes) {
 806                 num_planes = requested_planes;
 807                 memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
 808         }
 809
 810         /*
 811          * Ask the driver, whether the requested number of buffers, planes per
 812          * buffer and their sizes are acceptable
 813          */
 814         ret = call_qop(q, queue_setup, q, &num_buffers,
 815                        &num_planes, plane_sizes, q->alloc_devs);
 816         if (ret)
 817                 return ret;
 818
 819         /* Finally, allocate buffers and video memory */
 820         allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
 821                                 num_planes, plane_sizes);
 822         if (allocated_buffers == 0) {
 823                 dprintk(1, "memory allocation failed\n");
 824                 return -ENOMEM;
 825         }
 826
 827         /*
 828          * Check if driver can handle the so far allocated number of buffers.
 829          */
 830         if (allocated_buffers < num_buffers) {
 831                 num_buffers = allocated_buffers;
 832
 833                 /*
 834                  * q->num_buffers contains the total number of buffers, that the
 835                  * queue driver has set up
 836                  */
 837                 ret = call_qop(q, queue_setup, q, &num_buffers,
 838                                &num_planes, plane_sizes, q->alloc_devs);
 839
 840                 if (!ret && allocated_buffers < num_buffers)
 841                         ret = -ENOMEM;
 842
 843                 /*
 844                  * Either the driver has accepted a smaller number of buffers,
 845                  * or .queue_setup() returned an error
 846                  */
 847         }
 848
 849         mutex_lock(&q->mmap_lock);
 850         q->num_buffers += allocated_buffers;
 851
 852         if (ret < 0) {
 853                 /*
 854                  * Note: __vb2_queue_free() will subtract 'allocated_buffers'
 855                  * from q->num_buffers.
 856                  */
 857                 __vb2_queue_free(q, allocated_buffers);
 858                 mutex_unlock(&q->mmap_lock);
 859                 return -ENOMEM;
 860         }
 861         mutex_unlock(&q->mmap_lock);
 862
 863         /*
 864          * Return the number of successfully allocated buffers
 865          * to the userspace.
 866          */
 867         *count = allocated_buffers;
 868
 869         return 0;
 870 }
 871 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
 872
 873 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
 874 {
 875         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
 876                 return NULL;
 877
 878         return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
 879
 880 }
 881 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
 882
 883 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
 884 {
 885         if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
 886                 return NULL;
 887
 888         return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
 889 }
 890 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
 891
 892 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
 893 {
 894         struct vb2_queue *q = vb->vb2_queue;
 895         unsigned long flags;
 896         unsigned int plane;
 897
 898         if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
 899                 return;
 900
 901         if (WARN_ON(state != VB2_BUF_STATE_DONE &&
 902                     state != VB2_BUF_STATE_ERROR &&
 903                     state != VB2_BUF_STATE_QUEUED &&
 904                     state != VB2_BUF_STATE_REQUEUEING))
 905                 state = VB2_BUF_STATE_ERROR;
 906
 907 #ifdef CONFIG_VIDEO_ADV_DEBUG
 908         /*
 909          * Although this is not a callback, it still does have to balance
 910          * with the buf_queue op. So update this counter manually.
 911          */
 912         vb->cnt_buf_done++;
 913 #endif
 914         dprintk(4, "done processing on buffer %d, state: %d\n",
 915                         vb->index, state);
 916
 917         /* sync buffers */
 918         for (plane = 0; plane < vb->num_planes; ++plane)
 919                 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
 920
 921         spin_lock_irqsave(&q->done_lock, flags);
 922         if (state == VB2_BUF_STATE_QUEUED ||
 923             state == VB2_BUF_STATE_REQUEUEING) {
 924                 vb->state = VB2_BUF_STATE_QUEUED;
 925         } else {
 926                 /* Add the buffer to the done buffers list */
 927                 list_add_tail(&vb->done_entry, &q->done_list);
 928                 vb->state = state;
 929         }
 930         atomic_dec(&q->owned_by_drv_count);
 931         spin_unlock_irqrestore(&q->done_lock, flags);
 932
 933         trace_vb2_buf_done(q, vb);
 934
 935         switch (state) {
 936         case VB2_BUF_STATE_QUEUED:
 937                 return;
 938         case VB2_BUF_STATE_REQUEUEING:
 939                 if (q->start_streaming_called)
 940                         __enqueue_in_driver(vb);
 941                 return;
 942         default:
 943                 /* Inform any processes that may be waiting for buffers */
 944                 wake_up(&q->done_wq);
 945                 break;
 946         }
 947 }
 948 EXPORT_SYMBOL_GPL(vb2_buffer_done);
 949
 950 void vb2_discard_done(struct vb2_queue *q)
 951 {
 952         struct vb2_buffer *vb;
 953         unsigned long flags;
 954
 955         spin_lock_irqsave(&q->done_lock, flags);
 956         list_for_each_entry(vb, &q->done_list, done_entry)
 957                 vb->state = VB2_BUF_STATE_ERROR;
 958         spin_unlock_irqrestore(&q->done_lock, flags);
 959 }
 960 EXPORT_SYMBOL_GPL(vb2_discard_done);
 961
 962 /**
 963  * __qbuf_mmap() - handle qbuf of an MMAP buffer
 964  */
 965 static int __qbuf_mmap(struct vb2_buffer *vb, const void *pb)
 966 {
 967         int ret = 0;
 968
 969         if (pb)
 970                 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
 971                                  vb, pb, vb->planes);
 972         return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
 973 }
 974
 975 /**
 976  * __qbuf_userptr() - handle qbuf of a USERPTR buffer
 977  */
 978 static int __qbuf_userptr(struct vb2_buffer *vb, const void *pb)
 979 {
 980         struct vb2_plane planes[VB2_MAX_PLANES];
 981         struct vb2_queue *q = vb->vb2_queue;
 982         void *mem_priv;
 983         unsigned int plane;
 984         int ret = 0;
 985         enum dma_data_direction dma_dir =
 986                 q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
 987         bool reacquired = vb->planes[0].mem_priv == NULL;
 988
 989         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
 990         /* Copy relevant information provided by the userspace */
 991         if (pb)
 992                 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
 993                                  vb, pb, planes);
 994         if (ret)
 995                 return ret;
 996
 997         for (plane = 0; plane < vb->num_planes; ++plane) {
 998                 /* Skip the plane if already verified */
 999                 if (vb->planes[plane].m.userptr &&
1000                         vb->planes[plane].m.userptr == planes[plane].m.userptr
1001                         && vb->planes[plane].length == planes[plane].length)
1002                         continue;
1003
1004                 dprintk(3, "userspace address for plane %d changed, "
1005                                 "reacquiring memory\n", plane);
1006
1007                 /* Check if the provided plane buffer is large enough */
1008                 if (planes[plane].length < vb->planes[plane].min_length) {
1009                         dprintk(1, "provided buffer size %u is less than "
1010                                                 "setup size %u for plane %d\n",
1011                                                 planes[plane].length,
1012                                                 vb->planes[plane].min_length,
1013                                                 plane);
1014                         ret = -EINVAL;
1015                         goto err;
1016                 }
1017
1018                 /* Release previously acquired memory if present */
1019                 if (vb->planes[plane].mem_priv) {
1020                         if (!reacquired) {
1021                                 reacquired = true;
1022                                 call_void_vb_qop(vb, buf_cleanup, vb);
1023                         }
1024                         call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1025                 }
1026
1027                 vb->planes[plane].mem_priv = NULL;
1028                 vb->planes[plane].bytesused = 0;
1029                 vb->planes[plane].length = 0;
1030                 vb->planes[plane].m.userptr = 0;
1031                 vb->planes[plane].data_offset = 0;
1032
1033                 /* Acquire each plane's memory */
1034                 mem_priv = call_ptr_memop(vb, get_userptr,
1035                                 q->alloc_devs[plane] ? : q->dev,
1036                                 planes[plane].m.userptr,
1037                                 planes[plane].length, dma_dir);
1038                 if (IS_ERR(mem_priv)) {
1039                         dprintk(1, "failed acquiring userspace "
1040                                                 "memory for plane %d\n", plane);
1041                         ret = PTR_ERR(mem_priv);
1042                         goto err;
1043                 }
1044                 vb->planes[plane].mem_priv = mem_priv;
1045         }
1046
1047         /*
1048          * Now that everything is in order, copy relevant information
1049          * provided by userspace.
1050          */
1051         for (plane = 0; plane < vb->num_planes; ++plane) {
1052                 vb->planes[plane].bytesused = planes[plane].bytesused;
1053                 vb->planes[plane].length = planes[plane].length;
1054                 vb->planes[plane].m.userptr = planes[plane].m.userptr;
1055                 vb->planes[plane].data_offset = planes[plane].data_offset;
1056         }
1057
1058         if (reacquired) {
1059                 /*
1060                  * One or more planes changed, so we must call buf_init to do
1061                  * the driver-specific initialization on the newly acquired
1062                  * buffer, if provided.
1063                  */
1064                 ret = call_vb_qop(vb, buf_init, vb);
1065                 if (ret) {
1066                         dprintk(1, "buffer initialization failed\n");
1067                         goto err;
1068                 }
1069         }
1070
1071         ret = call_vb_qop(vb, buf_prepare, vb);
1072         if (ret) {
1073                 dprintk(1, "buffer preparation failed\n");
1074                 call_void_vb_qop(vb, buf_cleanup, vb);
1075                 goto err;
1076         }
1077
1078         return 0;
1079 err:
1080         /* In case of errors, release planes that were already acquired */
1081         for (plane = 0; plane < vb->num_planes; ++plane) {
1082                 if (vb->planes[plane].mem_priv)
1083                         call_void_memop(vb, put_userptr,
1084                                 vb->planes[plane].mem_priv);
1085                 vb->planes[plane].mem_priv = NULL;
1086                 vb->planes[plane].m.userptr = 0;
1087                 vb->planes[plane].length = 0;
1088         }
1089
1090         return ret;
1091 }
1092
1093 /**
1094  * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1095  */
1096 static int __qbuf_dmabuf(struct vb2_buffer *vb, const void *pb)
1097 {
1098         struct vb2_plane planes[VB2_MAX_PLANES];
1099         struct vb2_queue *q = vb->vb2_queue;
1100         void *mem_priv;
1101         unsigned int plane;
1102         int ret = 0;
1103         enum dma_data_direction dma_dir =
1104                 q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
1105         bool reacquired = vb->planes[0].mem_priv == NULL;
1106
1107         memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1108         /* Copy relevant information provided by the userspace */
1109         if (pb)
1110                 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1111                                  vb, pb, planes);
1112         if (ret)
1113                 return ret;
1114
1115         for (plane = 0; plane < vb->num_planes; ++plane) {
1116                 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1117
1118                 if (IS_ERR_OR_NULL(dbuf)) {
1119                         dprintk(1, "invalid dmabuf fd for plane %d\n",
1120                                 plane);
1121                         ret = -EINVAL;
1122                         goto err;
1123                 }
1124
1125                 /* use DMABUF size if length is not provided */
1126                 if (planes[plane].length == 0)
1127                         planes[plane].length = dbuf->size;
1128
1129                 if (planes[plane].length < vb->planes[plane].min_length) {
1130                         dprintk(1, "invalid dmabuf length %u for plane %d, "
1131                                 "minimum length %u\n",
1132                                 planes[plane].length, plane,
1133                                 vb->planes[plane].min_length);
1134                         dma_buf_put(dbuf);
1135                         ret = -EINVAL;
1136                         goto err;
1137                 }
1138
1139                 /* Skip the plane if already verified */
1140                 if (dbuf == vb->planes[plane].dbuf &&
1141                         vb->planes[plane].length == planes[plane].length) {
1142                         dma_buf_put(dbuf);
1143                         continue;
1144                 }
1145
1146                 dprintk(1, "buffer for plane %d changed\n", plane);
1147
1148                 if (!reacquired) {
1149                         reacquired = true;
1150                         call_void_vb_qop(vb, buf_cleanup, vb);
1151                 }
1152
1153                 /* Release previously acquired memory if present */
1154                 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1155                 vb->planes[plane].bytesused = 0;
1156                 vb->planes[plane].length = 0;
1157                 vb->planes[plane].m.fd = 0;
1158                 vb->planes[plane].data_offset = 0;
1159
1160                 /* Acquire each plane's memory */
1161                 mem_priv = call_ptr_memop(vb, attach_dmabuf,
1162                                 q->alloc_devs[plane] ? : q->dev,
1163                                 dbuf, planes[plane].length, dma_dir);
1164                 if (IS_ERR(mem_priv)) {
1165                         dprintk(1, "failed to attach dmabuf\n");
1166                         ret = PTR_ERR(mem_priv);
1167                         dma_buf_put(dbuf);
1168                         goto err;
1169                 }
1170
1171                 vb->planes[plane].dbuf = dbuf;
1172                 vb->planes[plane].mem_priv = mem_priv;
1173         }
1174
1175         /*
1176          * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1177          * here instead just before the DMA, while queueing the buffer(s) so
1178          * userspace knows sooner rather than later if the dma-buf map fails.
1179          */
1180         for (plane = 0; plane < vb->num_planes; ++plane) {
1181                 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1182                 if (ret) {
1183                         dprintk(1, "failed to map dmabuf for plane %d\n",
1184                                 plane);
1185                         goto err;
1186                 }
1187                 vb->planes[plane].dbuf_mapped = 1;
1188         }
1189
1190         /*
1191          * Now that everything is in order, copy relevant information
1192          * provided by userspace.
1193          */
1194         for (plane = 0; plane < vb->num_planes; ++plane) {
1195                 vb->planes[plane].bytesused = planes[plane].bytesused;
1196                 vb->planes[plane].length = planes[plane].length;
1197                 vb->planes[plane].m.fd = planes[plane].m.fd;
1198                 vb->planes[plane].data_offset = planes[plane].data_offset;
1199         }
1200
1201         if (reacquired) {
1202                 /*
1203                  * Call driver-specific initialization on the newly acquired buffer,
1204                  * if provided.
1205                  */
1206                 ret = call_vb_qop(vb, buf_init, vb);
1207                 if (ret) {
1208                         dprintk(1, "buffer initialization failed\n");
1209                         goto err;
1210                 }
1211         }
1212
1213         ret = call_vb_qop(vb, buf_prepare, vb);
1214         if (ret) {
1215                 dprintk(1, "buffer preparation failed\n");
1216                 call_void_vb_qop(vb, buf_cleanup, vb);
1217                 goto err;
1218         }
1219
1220         return 0;
1221 err:
1222         /* In case of errors, release planes that were already acquired */
1223         __vb2_buf_dmabuf_put(vb);
1224
1225         return ret;
1226 }
1227
1228 /**
1229  * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1230  */
1231 static void __enqueue_in_driver(struct vb2_buffer *vb)
1232 {
1233         struct vb2_queue *q = vb->vb2_queue;
1234         unsigned int plane;
1235
1236         vb->state = VB2_BUF_STATE_ACTIVE;
1237         atomic_inc(&q->owned_by_drv_count);
1238
1239         trace_vb2_buf_queue(q, vb);
1240
1241         /* sync buffers */
1242         for (plane = 0; plane < vb->num_planes; ++plane)
1243                 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1244
1245         call_void_vb_qop(vb, buf_queue, vb);
1246 }
1247
1248 static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
1249 {
1250         struct vb2_queue *q = vb->vb2_queue;
1251         int ret;
1252
1253         if (q->error) {
1254                 dprintk(1, "fatal error occurred on queue\n");
1255                 return -EIO;
1256         }
1257
1258         vb->state = VB2_BUF_STATE_PREPARING;
1259
1260         switch (q->memory) {
1261         case VB2_MEMORY_MMAP:
1262                 ret = __qbuf_mmap(vb, pb);
1263                 break;
1264         case VB2_MEMORY_USERPTR:
1265                 ret = __qbuf_userptr(vb, pb);
1266                 break;
1267         case VB2_MEMORY_DMABUF:
1268                 ret = __qbuf_dmabuf(vb, pb);
1269                 break;
1270         default:
1271                 WARN(1, "Invalid queue type\n");
1272                 ret = -EINVAL;
1273         }
1274
1275         if (ret)
1276                 dprintk(1, "buffer preparation failed: %d\n", ret);
1277         vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED;
1278
1279         return ret;
1280 }
1281
1282 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1283 {
1284         struct vb2_buffer *vb;
1285         int ret;
1286
1287         vb = q->bufs[index];
1288         if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1289                 dprintk(1, "invalid buffer state %d\n",
1290                         vb->state);
1291                 return -EINVAL;
1292         }
1293
1294         ret = __buf_prepare(vb, pb);
1295         if (ret)
1296                 return ret;
1297
1298         /* Fill buffer information for the userspace */
1299         call_void_bufop(q, fill_user_buffer, vb, pb);
1300
1301         dprintk(1, "prepare of buffer %d succeeded\n", vb->index);
1302
1303         return ret;
1304 }
1305 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1306
1307 /**
1308  * vb2_start_streaming() - Attempt to start streaming.
1309  * @q:          videobuf2 queue
1310  *
1311  * Attempt to start streaming. When this function is called there must be
1312  * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1313  * number of buffers required for the DMA engine to function). If the
1314  * @start_streaming op fails it is supposed to return all the driver-owned
1315  * buffers back to vb2 in state QUEUED. Check if that happened and if
1316  * not warn and reclaim them forcefully.
1317  */
1318 static int vb2_start_streaming(struct vb2_queue *q)
1319 {
1320         struct vb2_buffer *vb;
1321         int ret;
1322
1323         /*
1324          * If any buffers were queued before streamon,
1325          * we can now pass them to driver for processing.
1326          */
1327         list_for_each_entry(vb, &q->queued_list, queued_entry)
1328                 __enqueue_in_driver(vb);
1329
1330         /* Tell the driver to start streaming */
1331         q->start_streaming_called = 1;
1332         ret = call_qop(q, start_streaming, q,
1333                        atomic_read(&q->owned_by_drv_count));
1334         if (!ret)
1335                 return 0;
1336
1337         q->start_streaming_called = 0;
1338
1339         dprintk(1, "driver refused to start streaming\n");
1340         /*
1341          * If you see this warning, then the driver isn't cleaning up properly
1342          * after a failed start_streaming(). See the start_streaming()
1343          * documentation in videobuf2-core.h for more information how buffers
1344          * should be returned to vb2 in start_streaming().
1345          */
1346         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1347                 unsigned i;
1348
1349                 /*
1350                  * Forcefully reclaim buffers if the driver did not
1351                  * correctly return them to vb2.
1352                  */
1353                 for (i = 0; i < q->num_buffers; ++i) {
1354                         vb = q->bufs[i];
1355                         if (vb->state == VB2_BUF_STATE_ACTIVE)
1356                                 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1357                 }
1358                 /* Must be zero now */
1359                 WARN_ON(atomic_read(&q->owned_by_drv_count));
1360         }
1361         /*
1362          * If done_list is not empty, then start_streaming() didn't call
1363          * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1364          * STATE_DONE.
1365          */
1366         WARN_ON(!list_empty(&q->done_list));
1367         return ret;
1368 }
1369
1370 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
1371 {
1372         struct vb2_buffer *vb;
1373         enum vb2_buffer_state orig_state;
1374         int ret;
1375
1376         if (q->error) {
1377                 dprintk(1, "fatal error occurred on queue\n");
1378                 return -EIO;
1379         }
1380
1381         vb = q->bufs[index];
1382
1383         switch (vb->state) {
1384         case VB2_BUF_STATE_DEQUEUED:
1385                 ret = __buf_prepare(vb, pb);
1386                 if (ret)
1387                         return ret;
1388                 break;
1389         case VB2_BUF_STATE_PREPARED:
1390                 break;
1391         case VB2_BUF_STATE_PREPARING:
1392                 dprintk(1, "buffer still being prepared\n");
1393                 return -EINVAL;
1394         default:
1395                 dprintk(1, "invalid buffer state %d\n", vb->state);
1396                 return -EINVAL;
1397         }
1398
1399         /*
1400          * Add to the queued buffers list, a buffer will stay on it until
1401          * dequeued in dqbuf.
1402          */
1403         orig_state = vb->state;
1404         list_add_tail(&vb->queued_entry, &q->queued_list);
1405         q->queued_count++;
1406         q->waiting_for_buffers = false;
1407         vb->state = VB2_BUF_STATE_QUEUED;
1408
1409         if (pb)
1410                 call_void_bufop(q, copy_timestamp, vb, pb);
1411
1412         trace_vb2_qbuf(q, vb);
1413
1414         /*
1415          * If already streaming, give the buffer to driver for processing.
1416          * If not, the buffer will be given to driver on next streamon.
1417          */
1418         if (q->start_streaming_called)
1419                 __enqueue_in_driver(vb);
1420
1421         /* Fill buffer information for the userspace */
1422         if (pb)
1423                 call_void_bufop(q, fill_user_buffer, vb, pb);
1424
1425         /*
1426          * If streamon has been called, and we haven't yet called
1427          * start_streaming() since not enough buffers were queued, and
1428          * we now have reached the minimum number of queued buffers,
1429          * then we can finally call start_streaming().
1430          */
1431         if (q->streaming && !q->start_streaming_called &&
1432             q->queued_count >= q->min_buffers_needed) {
1433                 ret = vb2_start_streaming(q);
1434                 if (ret) {
1435                         /*
1436                          * Since vb2_core_qbuf will return with an error,
1437                          * we should return it to state DEQUEUED since
1438                          * the error indicates that the buffer wasn't queued.
1439                          */
1440                         list_del(&vb->queued_entry);
1441                         q->queued_count--;
1442                         vb->state = orig_state;
1443                         return ret;
1444                 }
1445         }
1446
1447         dprintk(1, "qbuf of buffer %d succeeded\n", vb->index);
1448         return 0;
1449 }
1450 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1451
1452 /**
1453  * __vb2_wait_for_done_vb() - wait for a buffer to become available
1454  * for dequeuing
1455  *
1456  * Will sleep if required for nonblocking == false.
1457  */
1458 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1459 {
1460         /*
1461          * All operations on vb_done_list are performed under done_lock
1462          * spinlock protection. However, buffers may be removed from
1463          * it and returned to userspace only while holding both driver's
1464          * lock and the done_lock spinlock. Thus we can be sure that as
1465          * long as we hold the driver's lock, the list will remain not
1466          * empty if list_empty() check succeeds.
1467          */
1468
1469         for (;;) {
1470                 int ret;
1471
1472                 if (!q->streaming) {
1473                         dprintk(1, "streaming off, will not wait for buffers\n");
1474                         return -EINVAL;
1475                 }
1476
1477                 if (q->error) {
1478                         dprintk(1, "Queue in error state, will not wait for buffers\n");
1479                         return -EIO;
1480                 }
1481
1482                 if (q->last_buffer_dequeued) {
1483                         dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1484                         return -EPIPE;
1485                 }
1486
1487                 if (!list_empty(&q->done_list)) {
1488                         /*
1489                          * Found a buffer that we were waiting for.
1490                          */
1491                         break;
1492                 }
1493
1494                 if (nonblocking) {
1495                         dprintk(1, "nonblocking and no buffers to dequeue, "
1496                                                                 "will not wait\n");
1497                         return -EAGAIN;
1498                 }
1499
1500                 /*
1501                  * We are streaming and blocking, wait for another buffer to
1502                  * become ready or for streamoff. Driver's lock is released to
1503                  * allow streamoff or qbuf to be called while waiting.
1504                  */
1505                 call_void_qop(q, wait_prepare, q);
1506
1507                 /*
1508                  * All locks have been released, it is safe to sleep now.
1509                  */
1510                 dprintk(3, "will sleep waiting for buffers\n");
1511                 ret = wait_event_interruptible(q->done_wq,
1512                                 !list_empty(&q->done_list) || !q->streaming ||
1513                                 q->error);
1514
1515                 /*
1516                  * We need to reevaluate both conditions again after reacquiring
1517                  * the locks or return an error if one occurred.
1518                  */
1519                 call_void_qop(q, wait_finish, q);
1520                 if (ret) {
1521                         dprintk(1, "sleep was interrupted\n");
1522                         return ret;
1523                 }
1524         }
1525         return 0;
1526 }
1527
1528 /**
1529  * __vb2_get_done_vb() - get a buffer ready for dequeuing
1530  *
1531  * Will sleep if required for nonblocking == false.
1532  */
1533 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1534                              void *pb, int nonblocking)
1535 {
1536         unsigned long flags;
1537         int ret = 0;
1538
1539         /*
1540          * Wait for at least one buffer to become available on the done_list.
1541          */
1542         ret = __vb2_wait_for_done_vb(q, nonblocking);
1543         if (ret)
1544                 return ret;
1545
1546         /*
1547          * Driver's lock has been held since we last verified that done_list
1548          * is not empty, so no need for another list_empty(done_list) check.
1549          */
1550         spin_lock_irqsave(&q->done_lock, flags);
1551         *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1552         /*
1553          * Only remove the buffer from done_list if all planes can be
1554          * handled. Some cases such as V4L2 file I/O and DVB have pb
1555          * == NULL; skip the check then as there's nothing to verify.
1556          */
1557         if (pb)
1558                 ret = call_bufop(q, verify_planes_array, *vb, pb);
1559         if (!ret)
1560                 list_del(&(*vb)->done_entry);
1561         spin_unlock_irqrestore(&q->done_lock, flags);
1562
1563         return ret;
1564 }
1565
1566 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1567 {
1568         if (!q->streaming) {
1569                 dprintk(1, "streaming off, will not wait for buffers\n");
1570                 return -EINVAL;
1571         }
1572
1573         if (q->start_streaming_called)
1574                 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1575         return 0;
1576 }
1577 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1578
1579 /**
1580  * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1581  */
1582 static void __vb2_dqbuf(struct vb2_buffer *vb)
1583 {
1584         struct vb2_queue *q = vb->vb2_queue;
1585         unsigned int i;
1586
1587         /* nothing to do if the buffer is already dequeued */
1588         if (vb->state == VB2_BUF_STATE_DEQUEUED)
1589                 return;
1590
1591         vb->state = VB2_BUF_STATE_DEQUEUED;
1592
1593         /* unmap DMABUF buffer */
1594         if (q->memory == VB2_MEMORY_DMABUF)
1595                 for (i = 0; i < vb->num_planes; ++i) {
1596                         if (!vb->planes[i].dbuf_mapped)
1597                                 continue;
1598                         call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
1599                         vb->planes[i].dbuf_mapped = 0;
1600                 }
1601 }
1602
1603 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1604                    bool nonblocking)
1605 {
1606         struct vb2_buffer *vb = NULL;
1607         int ret;
1608
1609         ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1610         if (ret < 0)
1611                 return ret;
1612
1613         switch (vb->state) {
1614         case VB2_BUF_STATE_DONE:
1615                 dprintk(3, "returning done buffer\n");
1616                 break;
1617         case VB2_BUF_STATE_ERROR:
1618                 dprintk(3, "returning done buffer with errors\n");
1619                 break;
1620         default:
1621                 dprintk(1, "invalid buffer state\n");
1622                 return -EINVAL;
1623         }
1624
1625         call_void_vb_qop(vb, buf_finish, vb);
1626
1627         if (pindex)
1628                 *pindex = vb->index;
1629
1630         /* Fill buffer information for the userspace */
1631         if (pb)
1632                 call_void_bufop(q, fill_user_buffer, vb, pb);
1633
1634         /* Remove from videobuf queue */
1635         list_del(&vb->queued_entry);
1636         q->queued_count--;
1637
1638         trace_vb2_dqbuf(q, vb);
1639
1640         /* go back to dequeued state */
1641         __vb2_dqbuf(vb);
1642
1643         dprintk(1, "dqbuf of buffer %d, with state %d\n",
1644                         vb->index, vb->state);
1645
1646         return 0;
1647
1648 }
1649 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
1650
1651 /**
1652  * __vb2_queue_cancel() - cancel and stop (pause) streaming
1653  *
1654  * Removes all queued buffers from driver's queue and all buffers queued by
1655  * userspace from videobuf's queue. Returns to state after reqbufs.
1656  */
1657 static void __vb2_queue_cancel(struct vb2_queue *q)
1658 {
1659         unsigned int i;
1660
1661         /*
1662          * Tell driver to stop all transactions and release all queued
1663          * buffers.
1664          */
1665         if (q->start_streaming_called)
1666                 call_void_qop(q, stop_streaming, q);
1667
1668         /*
1669          * If you see this warning, then the driver isn't cleaning up properly
1670          * in stop_streaming(). See the stop_streaming() documentation in
1671          * videobuf2-core.h for more information how buffers should be returned
1672          * to vb2 in stop_streaming().
1673          */
1674         if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1675                 for (i = 0; i < q->num_buffers; ++i)
1676                         if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
1677                                 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
1678                 /* Must be zero now */
1679                 WARN_ON(atomic_read(&q->owned_by_drv_count));
1680         }
1681
1682         q->streaming = 0;
1683         q->start_streaming_called = 0;
1684         q->queued_count = 0;
1685         q->error = 0;
1686
1687         /*
1688          * Remove all buffers from videobuf's list...
1689          */
1690         INIT_LIST_HEAD(&q->queued_list);
1691         /*
1692          * ...and done list; userspace will not receive any buffers it
1693          * has not already dequeued before initiating cancel.
1694          */
1695         INIT_LIST_HEAD(&q->done_list);
1696         atomic_set(&q->owned_by_drv_count, 0);
1697         wake_up_all(&q->done_wq);
1698
1699         /*
1700          * Reinitialize all buffers for next use.
1701          * Make sure to call buf_finish for any queued buffers. Normally
1702          * that's done in dqbuf, but that's not going to happen when we
1703          * cancel the whole queue. Note: this code belongs here, not in
1704          * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
1705          * call to __fill_user_buffer() after buf_finish(). That order can't
1706          * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
1707          */
1708         for (i = 0; i < q->num_buffers; ++i) {
1709                 struct vb2_buffer *vb = q->bufs[i];
1710
1711                 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1712                         vb->state = VB2_BUF_STATE_PREPARED;
1713                         call_void_vb_qop(vb, buf_finish, vb);
1714                 }
1715                 __vb2_dqbuf(vb);
1716         }
1717 }
1718
1719 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
1720 {
1721         int ret;
1722
1723         if (type != q->type) {
1724                 dprintk(1, "invalid stream type\n");
1725                 return -EINVAL;
1726         }
1727
1728         if (q->streaming) {
1729                 dprintk(3, "already streaming\n");
1730                 return 0;
1731         }
1732
1733         if (!q->num_buffers) {
1734                 dprintk(1, "no buffers have been allocated\n");
1735                 return -EINVAL;
1736         }
1737
1738         if (q->num_buffers < q->min_buffers_needed) {
1739                 dprintk(1, "need at least %u allocated buffers\n",
1740                                 q->min_buffers_needed);
1741                 return -EINVAL;
1742         }
1743
1744         /*
1745          * Tell driver to start streaming provided sufficient buffers
1746          * are available.
1747          */
1748         if (q->queued_count >= q->min_buffers_needed) {
1749                 ret = v4l_vb2q_enable_media_source(q);
1750                 if (ret)
1751                         return ret;
1752                 ret = vb2_start_streaming(q);
1753                 if (ret) {
1754                         __vb2_queue_cancel(q);
1755                         return ret;
1756                 }
1757         }
1758
1759         q->streaming = 1;
1760
1761         dprintk(3, "successful\n");
1762         return 0;
1763 }
1764 EXPORT_SYMBOL_GPL(vb2_core_streamon);
1765
1766 void vb2_queue_error(struct vb2_queue *q)
1767 {
1768         q->error = 1;
1769
1770         wake_up_all(&q->done_wq);
1771 }
1772 EXPORT_SYMBOL_GPL(vb2_queue_error);
1773
1774 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
1775 {
1776         if (type != q->type) {
1777                 dprintk(1, "invalid stream type\n");
1778                 return -EINVAL;
1779         }
1780
1781         /*
1782          * Cancel will pause streaming and remove all buffers from the driver
1783          * and videobuf, effectively returning control over them to userspace.
1784          *
1785          * Note that we do this even if q->streaming == 0: if you prepare or
1786          * queue buffers, and then call streamoff without ever having called
1787          * streamon, you would still expect those buffers to be returned to
1788          * their normal dequeued state.
1789          */
1790         __vb2_queue_cancel(q);
1791         q->waiting_for_buffers = !q->is_output;
1792         q->last_buffer_dequeued = false;
1793
1794         dprintk(3, "successful\n");
1795         return 0;
1796 }
1797 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
1798
1799 /**
1800  * __find_plane_by_offset() - find plane associated with the given offset off
1801  */
1802 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
1803                         unsigned int *_buffer, unsigned int *_plane)
1804 {
1805         struct vb2_buffer *vb;
1806         unsigned int buffer, plane;
1807
1808         /*
1809          * Go over all buffers and their planes, comparing the given offset
1810          * with an offset assigned to each plane. If a match is found,
1811          * return its buffer and plane numbers.
1812          */
1813         for (buffer = 0; buffer < q->num_buffers; ++buffer) {
1814                 vb = q->bufs[buffer];
1815
1816                 for (plane = 0; plane < vb->num_planes; ++plane) {
1817                         if (vb->planes[plane].m.offset == off) {
1818                                 *_buffer = buffer;
1819                                 *_plane = plane;
1820                                 return 0;
1821                         }
1822                 }
1823         }
1824
1825         return -EINVAL;
1826 }
1827
1828 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
1829                 unsigned int index, unsigned int plane, unsigned int flags)
1830 {
1831         struct vb2_buffer *vb = NULL;
1832         struct vb2_plane *vb_plane;
1833         int ret;
1834         struct dma_buf *dbuf;
1835
1836         if (q->memory != VB2_MEMORY_MMAP) {
1837                 dprintk(1, "queue is not currently set up for mmap\n");
1838                 return -EINVAL;
1839         }
1840
1841         if (!q->mem_ops->get_dmabuf) {
1842                 dprintk(1, "queue does not support DMA buffer exporting\n");
1843                 return -EINVAL;
1844         }
1845
1846         if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
1847                 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
1848                 return -EINVAL;
1849         }
1850
1851         if (type != q->type) {
1852                 dprintk(1, "invalid buffer type\n");
1853                 return -EINVAL;
1854         }
1855
1856         if (index >= q->num_buffers) {
1857                 dprintk(1, "buffer index out of range\n");
1858                 return -EINVAL;
1859         }
1860
1861         vb = q->bufs[index];
1862
1863         if (plane >= vb->num_planes) {
1864                 dprintk(1, "buffer plane out of range\n");
1865                 return -EINVAL;
1866         }
1867
1868         if (vb2_fileio_is_active(q)) {
1869                 dprintk(1, "expbuf: file io in progress\n");
1870                 return -EBUSY;
1871         }
1872
1873         vb_plane = &vb->planes[plane];
1874
1875         dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv,
1876                                 flags & O_ACCMODE);
1877         if (IS_ERR_OR_NULL(dbuf)) {
1878                 dprintk(1, "failed to export buffer %d, plane %d\n",
1879                         index, plane);
1880                 return -EINVAL;
1881         }
1882
1883         ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
1884         if (ret < 0) {
1885                 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
1886                         index, plane, ret);
1887                 dma_buf_put(dbuf);
1888                 return ret;
1889         }
1890
1891         dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
1892                 index, plane, ret);
1893         *fd = ret;
1894
1895         return 0;
1896 }
1897 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
1898
1899 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
1900 {
1901         unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
1902         struct vb2_buffer *vb;
1903         unsigned int buffer = 0, plane = 0;
1904         int ret;
1905         unsigned long length;
1906
1907         if (q->memory != VB2_MEMORY_MMAP) {
1908                 dprintk(1, "queue is not currently set up for mmap\n");
1909                 return -EINVAL;
1910         }
1911
1912         /*
1913          * Check memory area access mode.
1914          */
1915         if (!(vma->vm_flags & VM_SHARED)) {
1916                 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
1917                 return -EINVAL;
1918         }
1919         if (q->is_output) {
1920                 if (!(vma->vm_flags & VM_WRITE)) {
1921                         dprintk(1, "invalid vma flags, VM_WRITE needed\n");
1922                         return -EINVAL;
1923                 }
1924         } else {
1925                 if (!(vma->vm_flags & VM_READ)) {
1926                         dprintk(1, "invalid vma flags, VM_READ needed\n");
1927                         return -EINVAL;
1928                 }
1929         }
1930
1931         mutex_lock(&q->mmap_lock);
1932
1933         if (vb2_fileio_is_active(q)) {
1934                 dprintk(1, "mmap: file io in progress\n");
1935                 ret = -EBUSY;
1936                 goto unlock;
1937         }
1938
1939         /*
1940          * Find the plane corresponding to the offset passed by userspace.
1941          */
1942         ret = __find_plane_by_offset(q, off, &buffer, &plane);
1943         if (ret)
1944                 goto unlock;
1945
1946         vb = q->bufs[buffer];
1947
1948         /*
1949          * MMAP requires page_aligned buffers.
1950          * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
1951          * so, we need to do the same here.
1952          */
1953         length = PAGE_ALIGN(vb->planes[plane].length);
1954         if (length < (vma->vm_end - vma->vm_start)) {
1955                 dprintk(1,
1956                         "MMAP invalid, as it would overflow buffer length\n");
1957                 ret = -EINVAL;
1958                 goto unlock;
1959         }
1960
1961         ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
1962
1963 unlock:
1964         mutex_unlock(&q->mmap_lock);
1965         if (ret)
1966                 return ret;
1967
1968         dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
1969         return 0;
1970 }
1971 EXPORT_SYMBOL_GPL(vb2_mmap);
1972
1973 #ifndef CONFIG_MMU
1974 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
1975                                     unsigned long addr,
1976                                     unsigned long len,
1977                                     unsigned long pgoff,
1978                                     unsigned long flags)
1979 {
1980         unsigned long off = pgoff << PAGE_SHIFT;
1981         struct vb2_buffer *vb;
1982         unsigned int buffer, plane;
1983         void *vaddr;
1984         int ret;
1985
1986         if (q->memory != VB2_MEMORY_MMAP) {
1987                 dprintk(1, "queue is not currently set up for mmap\n");
1988                 return -EINVAL;
1989         }
1990
1991         /*
1992          * Find the plane corresponding to the offset passed by userspace.
1993          */
1994         ret = __find_plane_by_offset(q, off, &buffer, &plane);
1995         if (ret)
1996                 return ret;
1997
1998         vb = q->bufs[buffer];
1999
2000         vaddr = vb2_plane_vaddr(vb, plane);
2001         return vaddr ? (unsigned long)vaddr : -EINVAL;
2002 }
2003 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2004 #endif
2005
2006 int vb2_core_queue_init(struct vb2_queue *q)
2007 {
2008         /*
2009          * Sanity check
2010          */
2011         if (WARN_ON(!q)                   ||
2012             WARN_ON(!q->ops)              ||
2013             WARN_ON(!q->mem_ops)          ||
2014             WARN_ON(!q->type)             ||
2015             WARN_ON(!q->io_modes)         ||
2016             WARN_ON(!q->ops->queue_setup) ||
2017             WARN_ON(!q->ops->buf_queue))
2018                 return -EINVAL;
2019
2020         INIT_LIST_HEAD(&q->queued_list);
2021         INIT_LIST_HEAD(&q->done_list);
2022         spin_lock_init(&q->done_lock);
2023         mutex_init(&q->mmap_lock);
2024         init_waitqueue_head(&q->done_wq);
2025
2026         if (q->buf_struct_size == 0)
2027                 q->buf_struct_size = sizeof(struct vb2_buffer);
2028
2029         return 0;
2030 }
2031 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2032
2033 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2034 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2035 void vb2_core_queue_release(struct vb2_queue *q)
2036 {
2037         __vb2_cleanup_fileio(q);
2038         __vb2_queue_cancel(q);
2039         mutex_lock(&q->mmap_lock);
2040         __vb2_queue_free(q, q->num_buffers);
2041         mutex_unlock(&q->mmap_lock);
2042 }
2043 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2044
2045 unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file,
2046                 poll_table *wait)
2047 {
2048         unsigned long req_events = poll_requested_events(wait);
2049         struct vb2_buffer *vb = NULL;
2050         unsigned long flags;
2051
2052         if (!q->is_output && !(req_events & (POLLIN | POLLRDNORM)))
2053                 return 0;
2054         if (q->is_output && !(req_events & (POLLOUT | POLLWRNORM)))
2055                 return 0;
2056
2057         /*
2058          * Start file I/O emulator only if streaming API has not been used yet.
2059          */
2060         if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2061                 if (!q->is_output && (q->io_modes & VB2_READ) &&
2062                                 (req_events & (POLLIN | POLLRDNORM))) {
2063                         if (__vb2_init_fileio(q, 1))
2064                                 return POLLERR;
2065                 }
2066                 if (q->is_output && (q->io_modes & VB2_WRITE) &&
2067                                 (req_events & (POLLOUT | POLLWRNORM))) {
2068                         if (__vb2_init_fileio(q, 0))
2069                                 return POLLERR;
2070                         /*
2071                          * Write to OUTPUT queue can be done immediately.
2072                          */
2073                         return POLLOUT | POLLWRNORM;
2074                 }
2075         }
2076
2077         /*
2078          * There is nothing to wait for if the queue isn't streaming, or if the
2079          * error flag is set.
2080          */
2081         if (!vb2_is_streaming(q) || q->error)
2082                 return POLLERR;
2083
2084         /*
2085          * If this quirk is set and QBUF hasn't been called yet then
2086          * return POLLERR as well. This only affects capture queues, output
2087          * queues will always initialize waiting_for_buffers to false.
2088          * This quirk is set by V4L2 for backwards compatibility reasons.
2089          */
2090         if (q->quirk_poll_must_check_waiting_for_buffers &&
2091             q->waiting_for_buffers && (req_events & (POLLIN | POLLRDNORM)))
2092                 return POLLERR;
2093
2094         /*
2095          * For output streams you can call write() as long as there are fewer
2096          * buffers queued than there are buffers available.
2097          */
2098         if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2099                 return POLLOUT | POLLWRNORM;
2100
2101         if (list_empty(&q->done_list)) {
2102                 /*
2103                  * If the last buffer was dequeued from a capture queue,
2104                  * return immediately. DQBUF will return -EPIPE.
2105                  */
2106                 if (q->last_buffer_dequeued)
2107                         return POLLIN | POLLRDNORM;
2108
2109                 poll_wait(file, &q->done_wq, wait);
2110         }
2111
2112         /*
2113          * Take first buffer available for dequeuing.
2114          */
2115         spin_lock_irqsave(&q->done_lock, flags);
2116         if (!list_empty(&q->done_list))
2117                 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2118                                         done_entry);
2119         spin_unlock_irqrestore(&q->done_lock, flags);
2120
2121         if (vb && (vb->state == VB2_BUF_STATE_DONE
2122                         || vb->state == VB2_BUF_STATE_ERROR)) {
2123                 return (q->is_output) ?
2124                                 POLLOUT | POLLWRNORM :
2125                                 POLLIN | POLLRDNORM;
2126         }
2127         return 0;
2128 }
2129 EXPORT_SYMBOL_GPL(vb2_core_poll);
2130
2131 /**
2132  * struct vb2_fileio_buf - buffer context used by file io emulator
2133  *
2134  * vb2 provides a compatibility layer and emulator of file io (read and
2135  * write) calls on top of streaming API. This structure is used for
2136  * tracking context related to the buffers.
2137  */
2138 struct vb2_fileio_buf {
2139         void *vaddr;
2140         unsigned int size;
2141         unsigned int pos;
2142         unsigned int queued:1;
2143 };
2144
2145 /**
2146  * struct vb2_fileio_data - queue context used by file io emulator
2147  *
2148  * @cur_index:  the index of the buffer currently being read from or
2149  *              written to. If equal to q->num_buffers then a new buffer
2150  *              must be dequeued.
2151  * @initial_index: in the read() case all buffers are queued up immediately
2152  *              in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2153  *              buffers. However, in the write() case no buffers are initially
2154  *              queued, instead whenever a buffer is full it is queued up by
2155  *              __vb2_perform_fileio(). Only once all available buffers have
2156  *              been queued up will __vb2_perform_fileio() start to dequeue
2157  *              buffers. This means that initially __vb2_perform_fileio()
2158  *              needs to know what buffer index to use when it is queuing up
2159  *              the buffers for the first time. That initial index is stored
2160  *              in this field. Once it is equal to q->num_buffers all
2161  *              available buffers have been queued and __vb2_perform_fileio()
2162  *              should start the normal dequeue/queue cycle.
2163  *
2164  * vb2 provides a compatibility layer and emulator of file io (read and
2165  * write) calls on top of streaming API. For proper operation it required
2166  * this structure to save the driver state between each call of the read
2167  * or write function.
2168  */
2169 struct vb2_fileio_data {
2170         unsigned int count;
2171         unsigned int type;
2172         unsigned int memory;
2173         struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2174         unsigned int cur_index;
2175         unsigned int initial_index;
2176         unsigned int q_count;
2177         unsigned int dq_count;
2178         unsigned read_once:1;
2179         unsigned write_immediately:1;
2180 };
2181
2182 /**
2183  * __vb2_init_fileio() - initialize file io emulator
2184  * @q:          videobuf2 queue
2185  * @read:       mode selector (1 means read, 0 means write)
2186  */
2187 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2188 {
2189         struct vb2_fileio_data *fileio;
2190         int i, ret;
2191         unsigned int count = 0;
2192
2193         /*
2194          * Sanity check
2195          */
2196         if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2197                     (!read && !(q->io_modes & VB2_WRITE))))
2198                 return -EINVAL;
2199
2200         /*
2201          * Check if device supports mapping buffers to kernel virtual space.
2202          */
2203         if (!q->mem_ops->vaddr)
2204                 return -EBUSY;
2205
2206         /*
2207          * Check if streaming api has not been already activated.
2208          */
2209         if (q->streaming || q->num_buffers > 0)
2210                 return -EBUSY;
2211
2212         /*
2213          * Start with count 1, driver can increase it in queue_setup()
2214          */
2215         count = 1;
2216
2217         dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2218                 (read) ? "read" : "write", count, q->fileio_read_once,
2219                 q->fileio_write_immediately);
2220
2221         fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2222         if (fileio == NULL)
2223                 return -ENOMEM;
2224
2225         fileio->read_once = q->fileio_read_once;
2226         fileio->write_immediately = q->fileio_write_immediately;
2227
2228         /*
2229          * Request buffers and use MMAP type to force driver
2230          * to allocate buffers by itself.
2231          */
2232         fileio->count = count;
2233         fileio->memory = VB2_MEMORY_MMAP;
2234         fileio->type = q->type;
2235         q->fileio = fileio;
2236         ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2237         if (ret)
2238                 goto err_kfree;
2239
2240         /*
2241          * Check if plane_count is correct
2242          * (multiplane buffers are not supported).
2243          */
2244         if (q->bufs[0]->num_planes != 1) {
2245                 ret = -EBUSY;
2246                 goto err_reqbufs;
2247         }
2248
2249         /*
2250          * Get kernel address of each buffer.
2251          */
2252         for (i = 0; i < q->num_buffers; i++) {
2253                 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2254                 if (fileio->bufs[i].vaddr == NULL) {
2255                         ret = -EINVAL;
2256                         goto err_reqbufs;
2257                 }
2258                 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2259         }
2260
2261         /*
2262          * Read mode requires pre queuing of all buffers.
2263          */
2264         if (read) {
2265                 /*
2266                  * Queue all buffers.
2267                  */
2268                 for (i = 0; i < q->num_buffers; i++) {
2269                         ret = vb2_core_qbuf(q, i, NULL);
2270                         if (ret)
2271                                 goto err_reqbufs;
2272                         fileio->bufs[i].queued = 1;
2273                 }
2274                 /*
2275                  * All buffers have been queued, so mark that by setting
2276                  * initial_index to q->num_buffers
2277                  */
2278                 fileio->initial_index = q->num_buffers;
2279                 fileio->cur_index = q->num_buffers;
2280         }
2281
2282         /*
2283          * Start streaming.
2284          */
2285         ret = vb2_core_streamon(q, q->type);
2286         if (ret)
2287                 goto err_reqbufs;
2288
2289         return ret;
2290
2291 err_reqbufs:
2292         fileio->count = 0;
2293         vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2294
2295 err_kfree:
2296         q->fileio = NULL;
2297         kfree(fileio);
2298         return ret;
2299 }
2300
2301 /**
2302  * __vb2_cleanup_fileio() - free resourced used by file io emulator
2303  * @q:          videobuf2 queue
2304  */
2305 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2306 {
2307         struct vb2_fileio_data *fileio = q->fileio;
2308
2309         if (fileio) {
2310                 vb2_core_streamoff(q, q->type);
2311                 q->fileio = NULL;
2312                 fileio->count = 0;
2313                 vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2314                 kfree(fileio);
2315                 dprintk(3, "file io emulator closed\n");
2316         }
2317         return 0;
2318 }
2319
2320 /**
2321  * __vb2_perform_fileio() - perform a single file io (read or write) operation
2322  * @q:          videobuf2 queue
2323  * @data:       pointed to target userspace buffer
2324  * @count:      number of bytes to read or write
2325  * @ppos:       file handle position tracking pointer
2326  * @nonblock:   mode selector (1 means blocking calls, 0 means nonblocking)
2327  * @read:       access mode selector (1 means read, 0 means write)
2328  */
2329 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2330                 loff_t *ppos, int nonblock, int read)
2331 {
2332         struct vb2_fileio_data *fileio;
2333         struct vb2_fileio_buf *buf;
2334         bool is_multiplanar = q->is_multiplanar;
2335         /*
2336          * When using write() to write data to an output video node the vb2 core
2337          * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2338          * else is able to provide this information with the write() operation.
2339          */
2340         bool copy_timestamp = !read && q->copy_timestamp;
2341         unsigned index;
2342         int ret;
2343
2344         dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2345                 read ? "read" : "write", (long)*ppos, count,
2346                 nonblock ? "non" : "");
2347
2348         if (!data)
2349                 return -EINVAL;
2350
2351         /*
2352          * Initialize emulator on first call.
2353          */
2354         if (!vb2_fileio_is_active(q)) {
2355                 ret = __vb2_init_fileio(q, read);
2356                 dprintk(3, "vb2_init_fileio result: %d\n", ret);
2357                 if (ret)
2358                         return ret;
2359         }
2360         fileio = q->fileio;
2361
2362         /*
2363          * Check if we need to dequeue the buffer.
2364          */
2365         index = fileio->cur_index;
2366         if (index >= q->num_buffers) {
2367                 struct vb2_buffer *b;
2368
2369                 /*
2370                  * Call vb2_dqbuf to get buffer back.
2371                  */
2372                 ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2373                 dprintk(5, "vb2_dqbuf result: %d\n", ret);
2374                 if (ret)
2375                         return ret;
2376                 fileio->dq_count += 1;
2377
2378                 fileio->cur_index = index;
2379                 buf = &fileio->bufs[index];
2380                 b = q->bufs[index];
2381
2382                 /*
2383                  * Get number of bytes filled by the driver
2384                  */
2385                 buf->pos = 0;
2386                 buf->queued = 0;
2387                 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2388                                  : vb2_plane_size(q->bufs[index], 0);
2389                 /* Compensate for data_offset on read in the multiplanar case. */
2390                 if (is_multiplanar && read &&
2391                                 b->planes[0].data_offset < buf->size) {
2392                         buf->pos = b->planes[0].data_offset;
2393                         buf->size -= buf->pos;
2394                 }
2395         } else {
2396                 buf = &fileio->bufs[index];
2397         }
2398
2399         /*
2400          * Limit count on last few bytes of the buffer.
2401          */
2402         if (buf->pos + count > buf->size) {
2403                 count = buf->size - buf->pos;
2404                 dprintk(5, "reducing read count: %zd\n", count);
2405         }
2406
2407         /*
2408          * Transfer data to userspace.
2409          */
2410         dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
2411                 count, index, buf->pos);
2412         if (read)
2413                 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2414         else
2415                 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2416         if (ret) {
2417                 dprintk(3, "error copying data\n");
2418                 return -EFAULT;
2419         }
2420
2421         /*
2422          * Update counters.
2423          */
2424         buf->pos += count;
2425         *ppos += count;
2426
2427         /*
2428          * Queue next buffer if required.
2429          */
2430         if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2431                 struct vb2_buffer *b = q->bufs[index];
2432
2433                 /*
2434                  * Check if this is the last buffer to read.
2435                  */
2436                 if (read && fileio->read_once && fileio->dq_count == 1) {
2437                         dprintk(3, "read limit reached\n");
2438                         return __vb2_cleanup_fileio(q);
2439                 }
2440
2441                 /*
2442                  * Call vb2_qbuf and give buffer to the driver.
2443                  */
2444                 b->planes[0].bytesused = buf->pos;
2445
2446                 if (copy_timestamp)
2447                         b->timestamp = ktime_get_ns();
2448                 ret = vb2_core_qbuf(q, index, NULL);
2449                 dprintk(5, "vb2_dbuf result: %d\n", ret);
2450                 if (ret)
2451                         return ret;
2452
2453                 /*
2454                  * Buffer has been queued, update the status
2455                  */
2456                 buf->pos = 0;
2457                 buf->queued = 1;
2458                 buf->size = vb2_plane_size(q->bufs[index], 0);
2459                 fileio->q_count += 1;
2460                 /*
2461                  * If we are queuing up buffers for the first time, then
2462                  * increase initial_index by one.
2463                  */
2464                 if (fileio->initial_index < q->num_buffers)
2465                         fileio->initial_index++;
2466                 /*
2467                  * The next buffer to use is either a buffer that's going to be
2468                  * queued for the first time (initial_index < q->num_buffers)
2469                  * or it is equal to q->num_buffers, meaning that the next
2470                  * time we need to dequeue a buffer since we've now queued up
2471                  * all the 'first time' buffers.
2472                  */
2473                 fileio->cur_index = fileio->initial_index;
2474         }
2475
2476         /*
2477          * Return proper number of bytes processed.
2478          */
2479         if (ret == 0)
2480                 ret = count;
2481         return ret;
2482 }
2483
2484 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2485                 loff_t *ppos, int nonblocking)
2486 {
2487         return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2488 }
2489 EXPORT_SYMBOL_GPL(vb2_read);
2490
2491 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2492                 loff_t *ppos, int nonblocking)
2493 {
2494         return __vb2_perform_fileio(q, (char __user *) data, count,
2495                                                         ppos, nonblocking, 0);
2496 }
2497 EXPORT_SYMBOL_GPL(vb2_write);
2498
2499 struct vb2_threadio_data {
2500         struct task_struct *thread;
2501         vb2_thread_fnc fnc;
2502         void *priv;
2503         bool stop;
2504 };
2505
2506 static int vb2_thread(void *data)
2507 {
2508         struct vb2_queue *q = data;
2509         struct vb2_threadio_data *threadio = q->threadio;
2510         bool copy_timestamp = false;
2511         unsigned prequeue = 0;
2512         unsigned index = 0;
2513         int ret = 0;
2514
2515         if (q->is_output) {
2516                 prequeue = q->num_buffers;
2517                 copy_timestamp = q->copy_timestamp;
2518         }
2519
2520         set_freezable();
2521
2522         for (;;) {
2523                 struct vb2_buffer *vb;
2524
2525                 /*
2526                  * Call vb2_dqbuf to get buffer back.
2527                  */
2528                 if (prequeue) {
2529                         vb = q->bufs[index++];
2530                         prequeue--;
2531                 } else {
2532                         call_void_qop(q, wait_finish, q);
2533                         if (!threadio->stop)
2534                                 ret = vb2_core_dqbuf(q, &index, NULL, 0);
2535                         call_void_qop(q, wait_prepare, q);
2536                         dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
2537                         if (!ret)
2538                                 vb = q->bufs[index];
2539                 }
2540                 if (ret || threadio->stop)
2541                         break;
2542                 try_to_freeze();
2543
2544                 if (vb->state != VB2_BUF_STATE_ERROR)
2545                         if (threadio->fnc(vb, threadio->priv))
2546                                 break;
2547                 call_void_qop(q, wait_finish, q);
2548                 if (copy_timestamp)
2549                         vb->timestamp = ktime_get_ns();;
2550                 if (!threadio->stop)
2551                         ret = vb2_core_qbuf(q, vb->index, NULL);
2552                 call_void_qop(q, wait_prepare, q);
2553                 if (ret || threadio->stop)
2554                         break;
2555         }
2556
2557         /* Hmm, linux becomes *very* unhappy without this ... */
2558         while (!kthread_should_stop()) {
2559                 set_current_state(TASK_INTERRUPTIBLE);
2560                 schedule();
2561         }
2562         return 0;
2563 }
2564
2565 /*
2566  * This function should not be used for anything else but the videobuf2-dvb
2567  * support. If you think you have another good use-case for this, then please
2568  * contact the linux-media mailinglist first.
2569  */
2570 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
2571                      const char *thread_name)
2572 {
2573         struct vb2_threadio_data *threadio;
2574         int ret = 0;
2575
2576         if (q->threadio)
2577                 return -EBUSY;
2578         if (vb2_is_busy(q))
2579                 return -EBUSY;
2580         if (WARN_ON(q->fileio))
2581                 return -EBUSY;
2582
2583         threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
2584         if (threadio == NULL)
2585                 return -ENOMEM;
2586         threadio->fnc = fnc;
2587         threadio->priv = priv;
2588
2589         ret = __vb2_init_fileio(q, !q->is_output);
2590         dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
2591         if (ret)
2592                 goto nomem;
2593         q->threadio = threadio;
2594         threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
2595         if (IS_ERR(threadio->thread)) {
2596                 ret = PTR_ERR(threadio->thread);
2597                 threadio->thread = NULL;
2598                 goto nothread;
2599         }
2600         return 0;
2601
2602 nothread:
2603         __vb2_cleanup_fileio(q);
2604 nomem:
2605         kfree(threadio);
2606         return ret;
2607 }
2608 EXPORT_SYMBOL_GPL(vb2_thread_start);
2609
2610 int vb2_thread_stop(struct vb2_queue *q)
2611 {
2612         struct vb2_threadio_data *threadio = q->threadio;
2613         int err;
2614
2615         if (threadio == NULL)
2616                 return 0;
2617         threadio->stop = true;
2618         /* Wake up all pending sleeps in the thread */
2619         vb2_queue_error(q);
2620         err = kthread_stop(threadio->thread);
2621         __vb2_cleanup_fileio(q);
2622         threadio->thread = NULL;
2623         kfree(threadio);
2624         q->threadio = NULL;
2625         return err;
2626 }
2627 EXPORT_SYMBOL_GPL(vb2_thread_stop);
2628
2629 MODULE_DESCRIPTION("Media buffer core framework");
2630 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2631 MODULE_LICENSE("GPL");