dma-buf.c revision 9b495a5887994a6d74d5c261d012083a92b94738
1/* 2 * Framework for buffer objects that can be shared across devices/subsystems. 3 * 4 * Copyright(C) 2011 Linaro Limited. All rights reserved. 5 * Author: Sumit Semwal <sumit.semwal@ti.com> 6 * 7 * Many thanks to linaro-mm-sig list, and specially 8 * Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and 9 * Daniel Vetter <daniel@ffwll.ch> for their support in creation and 10 * refining of this idea. 11 * 12 * This program is free software; you can redistribute it and/or modify it 13 * under the terms of the GNU General Public License version 2 as published by 14 * the Free Software Foundation. 15 * 16 * This program is distributed in the hope that it will be useful, but WITHOUT 17 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 18 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 19 * more details. 20 * 21 * You should have received a copy of the GNU General Public License along with 22 * this program. If not, see <http://www.gnu.org/licenses/>. 23 */ 24 25#include <linux/fs.h> 26#include <linux/slab.h> 27#include <linux/dma-buf.h> 28#include <linux/fence.h> 29#include <linux/anon_inodes.h> 30#include <linux/export.h> 31#include <linux/debugfs.h> 32#include <linux/seq_file.h> 33#include <linux/poll.h> 34#include <linux/reservation.h> 35 36static inline int is_dma_buf_file(struct file *); 37 38struct dma_buf_list { 39 struct list_head head; 40 struct mutex lock; 41}; 42 43static struct dma_buf_list db_list; 44 45static int dma_buf_release(struct inode *inode, struct file *file) 46{ 47 struct dma_buf *dmabuf; 48 49 if (!is_dma_buf_file(file)) 50 return -EINVAL; 51 52 dmabuf = file->private_data; 53 54 BUG_ON(dmabuf->vmapping_counter); 55 56 /* 57 * Any fences that a dma-buf poll can wait on should be signaled 58 * before releasing dma-buf. This is the responsibility of each 59 * driver that uses the reservation objects. 60 * 61 * If you hit this BUG() it means someone dropped their ref to the 62 * dma-buf while still having pending operation to the buffer. 63 */ 64 BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active); 65 66 dmabuf->ops->release(dmabuf); 67 68 mutex_lock(&db_list.lock); 69 list_del(&dmabuf->list_node); 70 mutex_unlock(&db_list.lock); 71 72 if (dmabuf->resv == (struct reservation_object *)&dmabuf[1]) 73 reservation_object_fini(dmabuf->resv); 74 75 kfree(dmabuf); 76 return 0; 77} 78 79static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) 80{ 81 struct dma_buf *dmabuf; 82 83 if (!is_dma_buf_file(file)) 84 return -EINVAL; 85 86 dmabuf = file->private_data; 87 88 /* check for overflowing the buffer's size */ 89 if (vma->vm_pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) > 90 dmabuf->size >> PAGE_SHIFT) 91 return -EINVAL; 92 93 return dmabuf->ops->mmap(dmabuf, vma); 94} 95 96static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence) 97{ 98 struct dma_buf *dmabuf; 99 loff_t base; 100 101 if (!is_dma_buf_file(file)) 102 return -EBADF; 103 104 dmabuf = file->private_data; 105 106 /* only support discovering the end of the buffer, 107 but also allow SEEK_SET to maintain the idiomatic 108 SEEK_END(0), SEEK_CUR(0) pattern */ 109 if (whence == SEEK_END) 110 base = dmabuf->size; 111 else if (whence == SEEK_SET) 112 base = 0; 113 else 114 return -EINVAL; 115 116 if (offset != 0) 117 return -EINVAL; 118 119 return base + offset; 120} 121 122static void dma_buf_poll_cb(struct fence *fence, struct fence_cb *cb) 123{ 124 struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t *)cb; 125 unsigned long flags; 126 127 spin_lock_irqsave(&dcb->poll->lock, flags); 128 wake_up_locked_poll(dcb->poll, dcb->active); 129 dcb->active = 0; 130 spin_unlock_irqrestore(&dcb->poll->lock, flags); 131} 132 133static unsigned int dma_buf_poll(struct file *file, poll_table *poll) 134{ 135 struct dma_buf *dmabuf; 136 struct reservation_object *resv; 137 unsigned long events; 138 139 dmabuf = file->private_data; 140 if (!dmabuf || !dmabuf->resv) 141 return POLLERR; 142 143 resv = dmabuf->resv; 144 145 poll_wait(file, &dmabuf->poll, poll); 146 147 events = poll_requested_events(poll) & (POLLIN | POLLOUT); 148 if (!events) 149 return 0; 150 151 ww_mutex_lock(&resv->lock, NULL); 152 153 if (resv->fence_excl && (!(events & POLLOUT) || 154 resv->fence_shared_count == 0)) { 155 struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl; 156 unsigned long pevents = POLLIN; 157 158 if (resv->fence_shared_count == 0) 159 pevents |= POLLOUT; 160 161 spin_lock_irq(&dmabuf->poll.lock); 162 if (dcb->active) { 163 dcb->active |= pevents; 164 events &= ~pevents; 165 } else 166 dcb->active = pevents; 167 spin_unlock_irq(&dmabuf->poll.lock); 168 169 if (events & pevents) { 170 if (!fence_add_callback(resv->fence_excl, 171 &dcb->cb, dma_buf_poll_cb)) 172 events &= ~pevents; 173 else 174 /* 175 * No callback queued, wake up any additional 176 * waiters. 177 */ 178 dma_buf_poll_cb(NULL, &dcb->cb); 179 } 180 } 181 182 if ((events & POLLOUT) && resv->fence_shared_count > 0) { 183 struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared; 184 int i; 185 186 /* Only queue a new callback if no event has fired yet */ 187 spin_lock_irq(&dmabuf->poll.lock); 188 if (dcb->active) 189 events &= ~POLLOUT; 190 else 191 dcb->active = POLLOUT; 192 spin_unlock_irq(&dmabuf->poll.lock); 193 194 if (!(events & POLLOUT)) 195 goto out; 196 197 for (i = 0; i < resv->fence_shared_count; ++i) 198 if (!fence_add_callback(resv->fence_shared[i], 199 &dcb->cb, dma_buf_poll_cb)) { 200 events &= ~POLLOUT; 201 break; 202 } 203 204 /* No callback queued, wake up any additional waiters. */ 205 if (i == resv->fence_shared_count) 206 dma_buf_poll_cb(NULL, &dcb->cb); 207 } 208 209out: 210 ww_mutex_unlock(&resv->lock); 211 return events; 212} 213 214static const struct file_operations dma_buf_fops = { 215 .release = dma_buf_release, 216 .mmap = dma_buf_mmap_internal, 217 .llseek = dma_buf_llseek, 218 .poll = dma_buf_poll, 219}; 220 221/* 222 * is_dma_buf_file - Check if struct file* is associated with dma_buf 223 */ 224static inline int is_dma_buf_file(struct file *file) 225{ 226 return file->f_op == &dma_buf_fops; 227} 228 229/** 230 * dma_buf_export_named - Creates a new dma_buf, and associates an anon file 231 * with this buffer, so it can be exported. 232 * Also connect the allocator specific data and ops to the buffer. 233 * Additionally, provide a name string for exporter; useful in debugging. 234 * 235 * @priv: [in] Attach private data of allocator to this buffer 236 * @ops: [in] Attach allocator-defined dma buf ops to the new buffer. 237 * @size: [in] Size of the buffer 238 * @flags: [in] mode flags for the file. 239 * @exp_name: [in] name of the exporting module - useful for debugging. 240 * @resv: [in] reservation-object, NULL to allocate default one. 241 * 242 * Returns, on success, a newly created dma_buf object, which wraps the 243 * supplied private data and operations for dma_buf_ops. On either missing 244 * ops, or error in allocating struct dma_buf, will return negative error. 245 * 246 */ 247struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops, 248 size_t size, int flags, const char *exp_name, 249 struct reservation_object *resv) 250{ 251 struct dma_buf *dmabuf; 252 struct file *file; 253 size_t alloc_size = sizeof(struct dma_buf); 254 if (!resv) 255 alloc_size += sizeof(struct reservation_object); 256 else 257 /* prevent &dma_buf[1] == dma_buf->resv */ 258 alloc_size += 1; 259 260 if (WARN_ON(!priv || !ops 261 || !ops->map_dma_buf 262 || !ops->unmap_dma_buf 263 || !ops->release 264 || !ops->kmap_atomic 265 || !ops->kmap 266 || !ops->mmap)) { 267 return ERR_PTR(-EINVAL); 268 } 269 270 dmabuf = kzalloc(alloc_size, GFP_KERNEL); 271 if (dmabuf == NULL) 272 return ERR_PTR(-ENOMEM); 273 274 dmabuf->priv = priv; 275 dmabuf->ops = ops; 276 dmabuf->size = size; 277 dmabuf->exp_name = exp_name; 278 init_waitqueue_head(&dmabuf->poll); 279 dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll; 280 dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0; 281 282 if (!resv) { 283 resv = (struct reservation_object *)&dmabuf[1]; 284 reservation_object_init(resv); 285 } 286 dmabuf->resv = resv; 287 288 file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf, flags); 289 if (IS_ERR(file)) { 290 kfree(dmabuf); 291 return ERR_CAST(file); 292 } 293 294 file->f_mode |= FMODE_LSEEK; 295 dmabuf->file = file; 296 297 mutex_init(&dmabuf->lock); 298 INIT_LIST_HEAD(&dmabuf->attachments); 299 300 mutex_lock(&db_list.lock); 301 list_add(&dmabuf->list_node, &db_list.head); 302 mutex_unlock(&db_list.lock); 303 304 return dmabuf; 305} 306EXPORT_SYMBOL_GPL(dma_buf_export_named); 307 308 309/** 310 * dma_buf_fd - returns a file descriptor for the given dma_buf 311 * @dmabuf: [in] pointer to dma_buf for which fd is required. 312 * @flags: [in] flags to give to fd 313 * 314 * On success, returns an associated 'fd'. Else, returns error. 315 */ 316int dma_buf_fd(struct dma_buf *dmabuf, int flags) 317{ 318 int fd; 319 320 if (!dmabuf || !dmabuf->file) 321 return -EINVAL; 322 323 fd = get_unused_fd_flags(flags); 324 if (fd < 0) 325 return fd; 326 327 fd_install(fd, dmabuf->file); 328 329 return fd; 330} 331EXPORT_SYMBOL_GPL(dma_buf_fd); 332 333/** 334 * dma_buf_get - returns the dma_buf structure related to an fd 335 * @fd: [in] fd associated with the dma_buf to be returned 336 * 337 * On success, returns the dma_buf structure associated with an fd; uses 338 * file's refcounting done by fget to increase refcount. returns ERR_PTR 339 * otherwise. 340 */ 341struct dma_buf *dma_buf_get(int fd) 342{ 343 struct file *file; 344 345 file = fget(fd); 346 347 if (!file) 348 return ERR_PTR(-EBADF); 349 350 if (!is_dma_buf_file(file)) { 351 fput(file); 352 return ERR_PTR(-EINVAL); 353 } 354 355 return file->private_data; 356} 357EXPORT_SYMBOL_GPL(dma_buf_get); 358 359/** 360 * dma_buf_put - decreases refcount of the buffer 361 * @dmabuf: [in] buffer to reduce refcount of 362 * 363 * Uses file's refcounting done implicitly by fput() 364 */ 365void dma_buf_put(struct dma_buf *dmabuf) 366{ 367 if (WARN_ON(!dmabuf || !dmabuf->file)) 368 return; 369 370 fput(dmabuf->file); 371} 372EXPORT_SYMBOL_GPL(dma_buf_put); 373 374/** 375 * dma_buf_attach - Add the device to dma_buf's attachments list; optionally, 376 * calls attach() of dma_buf_ops to allow device-specific attach functionality 377 * @dmabuf: [in] buffer to attach device to. 378 * @dev: [in] device to be attached. 379 * 380 * Returns struct dma_buf_attachment * for this attachment; returns ERR_PTR on 381 * error. 382 */ 383struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, 384 struct device *dev) 385{ 386 struct dma_buf_attachment *attach; 387 int ret; 388 389 if (WARN_ON(!dmabuf || !dev)) 390 return ERR_PTR(-EINVAL); 391 392 attach = kzalloc(sizeof(struct dma_buf_attachment), GFP_KERNEL); 393 if (attach == NULL) 394 return ERR_PTR(-ENOMEM); 395 396 attach->dev = dev; 397 attach->dmabuf = dmabuf; 398 399 mutex_lock(&dmabuf->lock); 400 401 if (dmabuf->ops->attach) { 402 ret = dmabuf->ops->attach(dmabuf, dev, attach); 403 if (ret) 404 goto err_attach; 405 } 406 list_add(&attach->node, &dmabuf->attachments); 407 408 mutex_unlock(&dmabuf->lock); 409 return attach; 410 411err_attach: 412 kfree(attach); 413 mutex_unlock(&dmabuf->lock); 414 return ERR_PTR(ret); 415} 416EXPORT_SYMBOL_GPL(dma_buf_attach); 417 418/** 419 * dma_buf_detach - Remove the given attachment from dmabuf's attachments list; 420 * optionally calls detach() of dma_buf_ops for device-specific detach 421 * @dmabuf: [in] buffer to detach from. 422 * @attach: [in] attachment to be detached; is free'd after this call. 423 * 424 */ 425void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) 426{ 427 if (WARN_ON(!dmabuf || !attach)) 428 return; 429 430 mutex_lock(&dmabuf->lock); 431 list_del(&attach->node); 432 if (dmabuf->ops->detach) 433 dmabuf->ops->detach(dmabuf, attach); 434 435 mutex_unlock(&dmabuf->lock); 436 kfree(attach); 437} 438EXPORT_SYMBOL_GPL(dma_buf_detach); 439 440/** 441 * dma_buf_map_attachment - Returns the scatterlist table of the attachment; 442 * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the 443 * dma_buf_ops. 444 * @attach: [in] attachment whose scatterlist is to be returned 445 * @direction: [in] direction of DMA transfer 446 * 447 * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR 448 * on error. 449 */ 450struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, 451 enum dma_data_direction direction) 452{ 453 struct sg_table *sg_table = ERR_PTR(-EINVAL); 454 455 might_sleep(); 456 457 if (WARN_ON(!attach || !attach->dmabuf)) 458 return ERR_PTR(-EINVAL); 459 460 sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); 461 if (!sg_table) 462 sg_table = ERR_PTR(-ENOMEM); 463 464 return sg_table; 465} 466EXPORT_SYMBOL_GPL(dma_buf_map_attachment); 467 468/** 469 * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might 470 * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of 471 * dma_buf_ops. 472 * @attach: [in] attachment to unmap buffer from 473 * @sg_table: [in] scatterlist info of the buffer to unmap 474 * @direction: [in] direction of DMA transfer 475 * 476 */ 477void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, 478 struct sg_table *sg_table, 479 enum dma_data_direction direction) 480{ 481 might_sleep(); 482 483 if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) 484 return; 485 486 attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, 487 direction); 488} 489EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); 490 491 492/** 493 * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the 494 * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific 495 * preparations. Coherency is only guaranteed in the specified range for the 496 * specified access direction. 497 * @dmabuf: [in] buffer to prepare cpu access for. 498 * @start: [in] start of range for cpu access. 499 * @len: [in] length of range for cpu access. 500 * @direction: [in] length of range for cpu access. 501 * 502 * Can return negative error values, returns 0 on success. 503 */ 504int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len, 505 enum dma_data_direction direction) 506{ 507 int ret = 0; 508 509 if (WARN_ON(!dmabuf)) 510 return -EINVAL; 511 512 if (dmabuf->ops->begin_cpu_access) 513 ret = dmabuf->ops->begin_cpu_access(dmabuf, start, len, direction); 514 515 return ret; 516} 517EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access); 518 519/** 520 * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the 521 * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific 522 * actions. Coherency is only guaranteed in the specified range for the 523 * specified access direction. 524 * @dmabuf: [in] buffer to complete cpu access for. 525 * @start: [in] start of range for cpu access. 526 * @len: [in] length of range for cpu access. 527 * @direction: [in] length of range for cpu access. 528 * 529 * This call must always succeed. 530 */ 531void dma_buf_end_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len, 532 enum dma_data_direction direction) 533{ 534 WARN_ON(!dmabuf); 535 536 if (dmabuf->ops->end_cpu_access) 537 dmabuf->ops->end_cpu_access(dmabuf, start, len, direction); 538} 539EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); 540 541/** 542 * dma_buf_kmap_atomic - Map a page of the buffer object into kernel address 543 * space. The same restrictions as for kmap_atomic and friends apply. 544 * @dmabuf: [in] buffer to map page from. 545 * @page_num: [in] page in PAGE_SIZE units to map. 546 * 547 * This call must always succeed, any necessary preparations that might fail 548 * need to be done in begin_cpu_access. 549 */ 550void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num) 551{ 552 WARN_ON(!dmabuf); 553 554 return dmabuf->ops->kmap_atomic(dmabuf, page_num); 555} 556EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic); 557 558/** 559 * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic. 560 * @dmabuf: [in] buffer to unmap page from. 561 * @page_num: [in] page in PAGE_SIZE units to unmap. 562 * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap_atomic. 563 * 564 * This call must always succeed. 565 */ 566void dma_buf_kunmap_atomic(struct dma_buf *dmabuf, unsigned long page_num, 567 void *vaddr) 568{ 569 WARN_ON(!dmabuf); 570 571 if (dmabuf->ops->kunmap_atomic) 572 dmabuf->ops->kunmap_atomic(dmabuf, page_num, vaddr); 573} 574EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic); 575 576/** 577 * dma_buf_kmap - Map a page of the buffer object into kernel address space. The 578 * same restrictions as for kmap and friends apply. 579 * @dmabuf: [in] buffer to map page from. 580 * @page_num: [in] page in PAGE_SIZE units to map. 581 * 582 * This call must always succeed, any necessary preparations that might fail 583 * need to be done in begin_cpu_access. 584 */ 585void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num) 586{ 587 WARN_ON(!dmabuf); 588 589 return dmabuf->ops->kmap(dmabuf, page_num); 590} 591EXPORT_SYMBOL_GPL(dma_buf_kmap); 592 593/** 594 * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap. 595 * @dmabuf: [in] buffer to unmap page from. 596 * @page_num: [in] page in PAGE_SIZE units to unmap. 597 * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap. 598 * 599 * This call must always succeed. 600 */ 601void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num, 602 void *vaddr) 603{ 604 WARN_ON(!dmabuf); 605 606 if (dmabuf->ops->kunmap) 607 dmabuf->ops->kunmap(dmabuf, page_num, vaddr); 608} 609EXPORT_SYMBOL_GPL(dma_buf_kunmap); 610 611 612/** 613 * dma_buf_mmap - Setup up a userspace mmap with the given vma 614 * @dmabuf: [in] buffer that should back the vma 615 * @vma: [in] vma for the mmap 616 * @pgoff: [in] offset in pages where this mmap should start within the 617 * dma-buf buffer. 618 * 619 * This function adjusts the passed in vma so that it points at the file of the 620 * dma_buf operation. It also adjusts the starting pgoff and does bounds 621 * checking on the size of the vma. Then it calls the exporters mmap function to 622 * set up the mapping. 623 * 624 * Can return negative error values, returns 0 on success. 625 */ 626int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, 627 unsigned long pgoff) 628{ 629 struct file *oldfile; 630 int ret; 631 632 if (WARN_ON(!dmabuf || !vma)) 633 return -EINVAL; 634 635 /* check for offset overflow */ 636 if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) < pgoff) 637 return -EOVERFLOW; 638 639 /* check for overflowing the buffer's size */ 640 if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) > 641 dmabuf->size >> PAGE_SHIFT) 642 return -EINVAL; 643 644 /* readjust the vma */ 645 get_file(dmabuf->file); 646 oldfile = vma->vm_file; 647 vma->vm_file = dmabuf->file; 648 vma->vm_pgoff = pgoff; 649 650 ret = dmabuf->ops->mmap(dmabuf, vma); 651 if (ret) { 652 /* restore old parameters on failure */ 653 vma->vm_file = oldfile; 654 fput(dmabuf->file); 655 } else { 656 if (oldfile) 657 fput(oldfile); 658 } 659 return ret; 660 661} 662EXPORT_SYMBOL_GPL(dma_buf_mmap); 663 664/** 665 * dma_buf_vmap - Create virtual mapping for the buffer object into kernel 666 * address space. Same restrictions as for vmap and friends apply. 667 * @dmabuf: [in] buffer to vmap 668 * 669 * This call may fail due to lack of virtual mapping address space. 670 * These calls are optional in drivers. The intended use for them 671 * is for mapping objects linear in kernel space for high use objects. 672 * Please attempt to use kmap/kunmap before thinking about these interfaces. 673 * 674 * Returns NULL on error. 675 */ 676void *dma_buf_vmap(struct dma_buf *dmabuf) 677{ 678 void *ptr; 679 680 if (WARN_ON(!dmabuf)) 681 return NULL; 682 683 if (!dmabuf->ops->vmap) 684 return NULL; 685 686 mutex_lock(&dmabuf->lock); 687 if (dmabuf->vmapping_counter) { 688 dmabuf->vmapping_counter++; 689 BUG_ON(!dmabuf->vmap_ptr); 690 ptr = dmabuf->vmap_ptr; 691 goto out_unlock; 692 } 693 694 BUG_ON(dmabuf->vmap_ptr); 695 696 ptr = dmabuf->ops->vmap(dmabuf); 697 if (WARN_ON_ONCE(IS_ERR(ptr))) 698 ptr = NULL; 699 if (!ptr) 700 goto out_unlock; 701 702 dmabuf->vmap_ptr = ptr; 703 dmabuf->vmapping_counter = 1; 704 705out_unlock: 706 mutex_unlock(&dmabuf->lock); 707 return ptr; 708} 709EXPORT_SYMBOL_GPL(dma_buf_vmap); 710 711/** 712 * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap. 713 * @dmabuf: [in] buffer to vunmap 714 * @vaddr: [in] vmap to vunmap 715 */ 716void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) 717{ 718 if (WARN_ON(!dmabuf)) 719 return; 720 721 BUG_ON(!dmabuf->vmap_ptr); 722 BUG_ON(dmabuf->vmapping_counter == 0); 723 BUG_ON(dmabuf->vmap_ptr != vaddr); 724 725 mutex_lock(&dmabuf->lock); 726 if (--dmabuf->vmapping_counter == 0) { 727 if (dmabuf->ops->vunmap) 728 dmabuf->ops->vunmap(dmabuf, vaddr); 729 dmabuf->vmap_ptr = NULL; 730 } 731 mutex_unlock(&dmabuf->lock); 732} 733EXPORT_SYMBOL_GPL(dma_buf_vunmap); 734 735#ifdef CONFIG_DEBUG_FS 736static int dma_buf_describe(struct seq_file *s) 737{ 738 int ret; 739 struct dma_buf *buf_obj; 740 struct dma_buf_attachment *attach_obj; 741 int count = 0, attach_count; 742 size_t size = 0; 743 744 ret = mutex_lock_interruptible(&db_list.lock); 745 746 if (ret) 747 return ret; 748 749 seq_puts(s, "\nDma-buf Objects:\n"); 750 seq_puts(s, "size\tflags\tmode\tcount\texp_name\n"); 751 752 list_for_each_entry(buf_obj, &db_list.head, list_node) { 753 ret = mutex_lock_interruptible(&buf_obj->lock); 754 755 if (ret) { 756 seq_puts(s, 757 "\tERROR locking buffer object: skipping\n"); 758 continue; 759 } 760 761 seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\n", 762 buf_obj->size, 763 buf_obj->file->f_flags, buf_obj->file->f_mode, 764 (long)(buf_obj->file->f_count.counter), 765 buf_obj->exp_name); 766 767 seq_puts(s, "\tAttached Devices:\n"); 768 attach_count = 0; 769 770 list_for_each_entry(attach_obj, &buf_obj->attachments, node) { 771 seq_puts(s, "\t"); 772 773 seq_printf(s, "%s\n", dev_name(attach_obj->dev)); 774 attach_count++; 775 } 776 777 seq_printf(s, "Total %d devices attached\n\n", 778 attach_count); 779 780 count++; 781 size += buf_obj->size; 782 mutex_unlock(&buf_obj->lock); 783 } 784 785 seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size); 786 787 mutex_unlock(&db_list.lock); 788 return 0; 789} 790 791static int dma_buf_show(struct seq_file *s, void *unused) 792{ 793 void (*func)(struct seq_file *) = s->private; 794 func(s); 795 return 0; 796} 797 798static int dma_buf_debug_open(struct inode *inode, struct file *file) 799{ 800 return single_open(file, dma_buf_show, inode->i_private); 801} 802 803static const struct file_operations dma_buf_debug_fops = { 804 .open = dma_buf_debug_open, 805 .read = seq_read, 806 .llseek = seq_lseek, 807 .release = single_release, 808}; 809 810static struct dentry *dma_buf_debugfs_dir; 811 812static int dma_buf_init_debugfs(void) 813{ 814 int err = 0; 815 dma_buf_debugfs_dir = debugfs_create_dir("dma_buf", NULL); 816 if (IS_ERR(dma_buf_debugfs_dir)) { 817 err = PTR_ERR(dma_buf_debugfs_dir); 818 dma_buf_debugfs_dir = NULL; 819 return err; 820 } 821 822 err = dma_buf_debugfs_create_file("bufinfo", dma_buf_describe); 823 824 if (err) 825 pr_debug("dma_buf: debugfs: failed to create node bufinfo\n"); 826 827 return err; 828} 829 830static void dma_buf_uninit_debugfs(void) 831{ 832 if (dma_buf_debugfs_dir) 833 debugfs_remove_recursive(dma_buf_debugfs_dir); 834} 835 836int dma_buf_debugfs_create_file(const char *name, 837 int (*write)(struct seq_file *)) 838{ 839 struct dentry *d; 840 841 d = debugfs_create_file(name, S_IRUGO, dma_buf_debugfs_dir, 842 write, &dma_buf_debug_fops); 843 844 return PTR_ERR_OR_ZERO(d); 845} 846#else 847static inline int dma_buf_init_debugfs(void) 848{ 849 return 0; 850} 851static inline void dma_buf_uninit_debugfs(void) 852{ 853} 854#endif 855 856static int __init dma_buf_init(void) 857{ 858 mutex_init(&db_list.lock); 859 INIT_LIST_HEAD(&db_list.head); 860 dma_buf_init_debugfs(); 861 return 0; 862} 863subsys_initcall(dma_buf_init); 864 865static void __exit dma_buf_deinit(void) 866{ 867 dma_buf_uninit_debugfs(); 868} 869__exitcall(dma_buf_deinit); 870