1 #include <linux/module.h> 2 #include <linux/string.h> 3 #include <linux/bitops.h> 4 #include <linux/slab.h> 5 #include <linux/init.h> 6 #include <linux/log2.h> 7 #include <linux/usb.h> 8 #include <linux/wait.h> 9 #include "hcd.h" 10 11 #define to_urb(d) container_of(d, struct urb, kref) 12 13 static DEFINE_SPINLOCK(usb_reject_lock); 14 15 static void urb_destroy(struct kref *kref) 16 { 17 struct urb *urb = to_urb(kref); 18 19 if (urb->transfer_flags & URB_FREE_BUFFER) 20 kfree(urb->transfer_buffer); 21 22 kfree(urb); 23 } 24 25 /** 26 * usb_init_urb - initializes a urb so that it can be used by a USB driver 27 * @urb: pointer to the urb to initialize 28 * 29 * Initializes a urb so that the USB subsystem can use it properly. 30 * 31 * If a urb is created with a call to usb_alloc_urb() it is not 32 * necessary to call this function. Only use this if you allocate the 33 * space for a struct urb on your own. If you call this function, be 34 * careful when freeing the memory for your urb that it is no longer in 35 * use by the USB core. 36 * 37 * Only use this function if you _really_ understand what you are doing. 38 */ 39 void usb_init_urb(struct urb *urb) 40 { 41 if (urb) { 42 memset(urb, 0, sizeof(*urb)); 43 kref_init(&urb->kref); 44 INIT_LIST_HEAD(&urb->anchor_list); 45 } 46 } 47 EXPORT_SYMBOL_GPL(usb_init_urb); 48 49 /** 50 * usb_alloc_urb - creates a new urb for a USB driver to use 51 * @iso_packets: number of iso packets for this urb 52 * @mem_flags: the type of memory to allocate, see kmalloc() for a list of 53 * valid options for this. 54 * 55 * Creates an urb for the USB driver to use, initializes a few internal 56 * structures, incrementes the usage counter, and returns a pointer to it. 57 * 58 * If no memory is available, NULL is returned. 59 * 60 * If the driver want to use this urb for interrupt, control, or bulk 61 * endpoints, pass '0' as the number of iso packets. 62 * 63 * The driver must call usb_free_urb() when it is finished with the urb. 64 */ 65 struct urb *usb_alloc_urb(int iso_packets, gfp_t mem_flags) 66 { 67 struct urb *urb; 68 69 urb = kmalloc(sizeof(struct urb) + 70 iso_packets * sizeof(struct usb_iso_packet_descriptor), 71 mem_flags); 72 if (!urb) { 73 printk(KERN_ERR "alloc_urb: kmalloc failed\n"); 74 return NULL; 75 } 76 usb_init_urb(urb); 77 return urb; 78 } 79 EXPORT_SYMBOL_GPL(usb_alloc_urb); 80 81 /** 82 * usb_free_urb - frees the memory used by a urb when all users of it are finished 83 * @urb: pointer to the urb to free, may be NULL 84 * 85 * Must be called when a user of a urb is finished with it. When the last user 86 * of the urb calls this function, the memory of the urb is freed. 87 * 88 * Note: The transfer buffer associated with the urb is not freed, that must be 89 * done elsewhere. 90 */ 91 void usb_free_urb(struct urb *urb) 92 { 93 if (urb) 94 kref_put(&urb->kref, urb_destroy); 95 } 96 EXPORT_SYMBOL_GPL(usb_free_urb); 97 98 /** 99 * usb_get_urb - increments the reference count of the urb 100 * @urb: pointer to the urb to modify, may be NULL 101 * 102 * This must be called whenever a urb is transferred from a device driver to a 103 * host controller driver. This allows proper reference counting to happen 104 * for urbs. 105 * 106 * A pointer to the urb with the incremented reference counter is returned. 107 */ 108 struct urb *usb_get_urb(struct urb *urb) 109 { 110 if (urb) 111 kref_get(&urb->kref); 112 return urb; 113 } 114 EXPORT_SYMBOL_GPL(usb_get_urb); 115 116 /** 117 * usb_anchor_urb - anchors an URB while it is processed 118 * @urb: pointer to the urb to anchor 119 * @anchor: pointer to the anchor 120 * 121 * This can be called to have access to URBs which are to be executed 122 * without bothering to track them 123 */ 124 void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor) 125 { 126 unsigned long flags; 127 128 spin_lock_irqsave(&anchor->lock, flags); 129 usb_get_urb(urb); 130 list_add_tail(&urb->anchor_list, &anchor->urb_list); 131 urb->anchor = anchor; 132 133 if (unlikely(anchor->poisoned)) { 134 spin_lock(&usb_reject_lock); 135 urb->reject++; 136 spin_unlock(&usb_reject_lock); 137 } 138 139 spin_unlock_irqrestore(&anchor->lock, flags); 140 } 141 EXPORT_SYMBOL_GPL(usb_anchor_urb); 142 143 /** 144 * usb_unanchor_urb - unanchors an URB 145 * @urb: pointer to the urb to anchor 146 * 147 * Call this to stop the system keeping track of this URB 148 */ 149 void usb_unanchor_urb(struct urb *urb) 150 { 151 unsigned long flags; 152 struct usb_anchor *anchor; 153 154 if (!urb) 155 return; 156 157 anchor = urb->anchor; 158 if (!anchor) 159 return; 160 161 spin_lock_irqsave(&anchor->lock, flags); 162 if (unlikely(anchor != urb->anchor)) { 163 /* we've lost the race to another thread */ 164 spin_unlock_irqrestore(&anchor->lock, flags); 165 return; 166 } 167 urb->anchor = NULL; 168 list_del(&urb->anchor_list); 169 spin_unlock_irqrestore(&anchor->lock, flags); 170 usb_put_urb(urb); 171 if (list_empty(&anchor->urb_list)) 172 wake_up(&anchor->wait); 173 } 174 EXPORT_SYMBOL_GPL(usb_unanchor_urb); 175 176 /*-------------------------------------------------------------------*/ 177 178 /** 179 * usb_submit_urb - issue an asynchronous transfer request for an endpoint 180 * @urb: pointer to the urb describing the request 181 * @mem_flags: the type of memory to allocate, see kmalloc() for a list 182 * of valid options for this. 183 * 184 * This submits a transfer request, and transfers control of the URB 185 * describing that request to the USB subsystem. Request completion will 186 * be indicated later, asynchronously, by calling the completion handler. 187 * The three types of completion are success, error, and unlink 188 * (a software-induced fault, also called "request cancellation"). 189 * 190 * URBs may be submitted in interrupt context. 191 * 192 * The caller must have correctly initialized the URB before submitting 193 * it. Functions such as usb_fill_bulk_urb() and usb_fill_control_urb() are 194 * available to ensure that most fields are correctly initialized, for 195 * the particular kind of transfer, although they will not initialize 196 * any transfer flags. 197 * 198 * Successful submissions return 0; otherwise this routine returns a 199 * negative error number. If the submission is successful, the complete() 200 * callback from the URB will be called exactly once, when the USB core and 201 * Host Controller Driver (HCD) are finished with the URB. When the completion 202 * function is called, control of the URB is returned to the device 203 * driver which issued the request. The completion handler may then 204 * immediately free or reuse that URB. 205 * 206 * With few exceptions, USB device drivers should never access URB fields 207 * provided by usbcore or the HCD until its complete() is called. 208 * The exceptions relate to periodic transfer scheduling. For both 209 * interrupt and isochronous urbs, as part of successful URB submission 210 * urb->interval is modified to reflect the actual transfer period used 211 * (normally some power of two units). And for isochronous urbs, 212 * urb->start_frame is modified to reflect when the URB's transfers were 213 * scheduled to start. Not all isochronous transfer scheduling policies 214 * will work, but most host controller drivers should easily handle ISO 215 * queues going from now until 10-200 msec into the future. 216 * 217 * For control endpoints, the synchronous usb_control_msg() call is 218 * often used (in non-interrupt context) instead of this call. 219 * That is often used through convenience wrappers, for the requests 220 * that are standardized in the USB 2.0 specification. For bulk 221 * endpoints, a synchronous usb_bulk_msg() call is available. 222 * 223 * Request Queuing: 224 * 225 * URBs may be submitted to endpoints before previous ones complete, to 226 * minimize the impact of interrupt latencies and system overhead on data 227 * throughput. With that queuing policy, an endpoint's queue would never 228 * be empty. This is required for continuous isochronous data streams, 229 * and may also be required for some kinds of interrupt transfers. Such 230 * queuing also maximizes bandwidth utilization by letting USB controllers 231 * start work on later requests before driver software has finished the 232 * completion processing for earlier (successful) requests. 233 * 234 * As of Linux 2.6, all USB endpoint transfer queues support depths greater 235 * than one. This was previously a HCD-specific behavior, except for ISO 236 * transfers. Non-isochronous endpoint queues are inactive during cleanup 237 * after faults (transfer errors or cancellation). 238 * 239 * Reserved Bandwidth Transfers: 240 * 241 * Periodic transfers (interrupt or isochronous) are performed repeatedly, 242 * using the interval specified in the urb. Submitting the first urb to 243 * the endpoint reserves the bandwidth necessary to make those transfers. 244 * If the USB subsystem can't allocate sufficient bandwidth to perform 245 * the periodic request, submitting such a periodic request should fail. 246 * 247 * Device drivers must explicitly request that repetition, by ensuring that 248 * some URB is always on the endpoint's queue (except possibly for short 249 * periods during completion callacks). When there is no longer an urb 250 * queued, the endpoint's bandwidth reservation is canceled. This means 251 * drivers can use their completion handlers to ensure they keep bandwidth 252 * they need, by reinitializing and resubmitting the just-completed urb 253 * until the driver longer needs that periodic bandwidth. 254 * 255 * Memory Flags: 256 * 257 * The general rules for how to decide which mem_flags to use 258 * are the same as for kmalloc. There are four 259 * different possible values; GFP_KERNEL, GFP_NOFS, GFP_NOIO and 260 * GFP_ATOMIC. 261 * 262 * GFP_NOFS is not ever used, as it has not been implemented yet. 263 * 264 * GFP_ATOMIC is used when 265 * (a) you are inside a completion handler, an interrupt, bottom half, 266 * tasklet or timer, or 267 * (b) you are holding a spinlock or rwlock (does not apply to 268 * semaphores), or 269 * (c) current->state != TASK_RUNNING, this is the case only after 270 * you've changed it. 271 * 272 * GFP_NOIO is used in the block io path and error handling of storage 273 * devices. 274 * 275 * All other situations use GFP_KERNEL. 276 * 277 * Some more specific rules for mem_flags can be inferred, such as 278 * (1) start_xmit, timeout, and receive methods of network drivers must 279 * use GFP_ATOMIC (they are called with a spinlock held); 280 * (2) queuecommand methods of scsi drivers must use GFP_ATOMIC (also 281 * called with a spinlock held); 282 * (3) If you use a kernel thread with a network driver you must use 283 * GFP_NOIO, unless (b) or (c) apply; 284 * (4) after you have done a down() you can use GFP_KERNEL, unless (b) or (c) 285 * apply or your are in a storage driver's block io path; 286 * (5) USB probe and disconnect can use GFP_KERNEL unless (b) or (c) apply; and 287 * (6) changing firmware on a running storage or net device uses 288 * GFP_NOIO, unless b) or c) apply 289 * 290 */ 291 int usb_submit_urb(struct urb *urb, gfp_t mem_flags) 292 { 293 int xfertype, max; 294 struct usb_device *dev; 295 struct usb_host_endpoint *ep; 296 int is_out; 297 298 if (!urb || urb->hcpriv || !urb->complete) 299 return -EINVAL; 300 dev = urb->dev; 301 if ((!dev) || (dev->state < USB_STATE_DEFAULT)) 302 return -ENODEV; 303 304 /* For now, get the endpoint from the pipe. Eventually drivers 305 * will be required to set urb->ep directly and we will eliminate 306 * urb->pipe. 307 */ 308 ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out) 309 [usb_pipeendpoint(urb->pipe)]; 310 if (!ep) 311 return -ENOENT; 312 313 urb->ep = ep; 314 urb->status = -EINPROGRESS; 315 urb->actual_length = 0; 316 317 /* Lots of sanity checks, so HCDs can rely on clean data 318 * and don't need to duplicate tests 319 */ 320 xfertype = usb_endpoint_type(&ep->desc); 321 if (xfertype == USB_ENDPOINT_XFER_CONTROL) { 322 struct usb_ctrlrequest *setup = 323 (struct usb_ctrlrequest *) urb->setup_packet; 324 325 if (!setup) 326 return -ENOEXEC; 327 is_out = !(setup->bRequestType & USB_DIR_IN) || 328 !setup->wLength; 329 } else { 330 is_out = usb_endpoint_dir_out(&ep->desc); 331 } 332 333 /* Cache the direction for later use */ 334 urb->transfer_flags = (urb->transfer_flags & ~URB_DIR_MASK) | 335 (is_out ? URB_DIR_OUT : URB_DIR_IN); 336 337 if (xfertype != USB_ENDPOINT_XFER_CONTROL && 338 dev->state < USB_STATE_CONFIGURED) 339 return -ENODEV; 340 341 max = le16_to_cpu(ep->desc.wMaxPacketSize); 342 if (max <= 0) { 343 dev_dbg(&dev->dev, 344 "bogus endpoint ep%d%s in %s (bad maxpacket %d)\n", 345 usb_endpoint_num(&ep->desc), is_out ? "out" : "in", 346 __func__, max); 347 return -EMSGSIZE; 348 } 349 350 /* periodic transfers limit size per frame/uframe, 351 * but drivers only control those sizes for ISO. 352 * while we're checking, initialize return status. 353 */ 354 if (xfertype == USB_ENDPOINT_XFER_ISOC) { 355 int n, len; 356 357 /* "high bandwidth" mode, 1-3 packets/uframe? */ 358 if (dev->speed == USB_SPEED_HIGH) { 359 int mult = 1 + ((max >> 11) & 0x03); 360 max &= 0x07ff; 361 max *= mult; 362 } 363 364 if (urb->number_of_packets <= 0) 365 return -EINVAL; 366 for (n = 0; n < urb->number_of_packets; n++) { 367 len = urb->iso_frame_desc[n].length; 368 if (len < 0 || len > max) 369 return -EMSGSIZE; 370 urb->iso_frame_desc[n].status = -EXDEV; 371 urb->iso_frame_desc[n].actual_length = 0; 372 } 373 } 374 375 /* the I/O buffer must be mapped/unmapped, except when length=0 */ 376 if (urb->transfer_buffer_length < 0) 377 return -EMSGSIZE; 378 379 #ifdef DEBUG 380 /* stuff that drivers shouldn't do, but which shouldn't 381 * cause problems in HCDs if they get it wrong. 382 */ 383 { 384 unsigned int orig_flags = urb->transfer_flags; 385 unsigned int allowed; 386 387 /* enforce simple/standard policy */ 388 allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_SETUP_DMA_MAP | 389 URB_NO_INTERRUPT | URB_DIR_MASK | URB_FREE_BUFFER); 390 switch (xfertype) { 391 case USB_ENDPOINT_XFER_BULK: 392 if (is_out) 393 allowed |= URB_ZERO_PACKET; 394 /* FALLTHROUGH */ 395 case USB_ENDPOINT_XFER_CONTROL: 396 allowed |= URB_NO_FSBR; /* only affects UHCI */ 397 /* FALLTHROUGH */ 398 default: /* all non-iso endpoints */ 399 if (!is_out) 400 allowed |= URB_SHORT_NOT_OK; 401 break; 402 case USB_ENDPOINT_XFER_ISOC: 403 allowed |= URB_ISO_ASAP; 404 break; 405 } 406 urb->transfer_flags &= allowed; 407 408 /* fail if submitter gave bogus flags */ 409 if (urb->transfer_flags != orig_flags) { 410 dev_err(&dev->dev, "BOGUS urb flags, %x --> %x\n", 411 orig_flags, urb->transfer_flags); 412 return -EINVAL; 413 } 414 } 415 #endif 416 /* 417 * Force periodic transfer intervals to be legal values that are 418 * a power of two (so HCDs don't need to). 419 * 420 * FIXME want bus->{intr,iso}_sched_horizon values here. Each HC 421 * supports different values... this uses EHCI/UHCI defaults (and 422 * EHCI can use smaller non-default values). 423 */ 424 switch (xfertype) { 425 case USB_ENDPOINT_XFER_ISOC: 426 case USB_ENDPOINT_XFER_INT: 427 /* too small? */ 428 if (urb->interval <= 0) 429 return -EINVAL; 430 /* too big? */ 431 switch (dev->speed) { 432 case USB_SPEED_HIGH: /* units are microframes */ 433 /* NOTE usb handles 2^15 */ 434 if (urb->interval > (1024 * 8)) 435 urb->interval = 1024 * 8; 436 max = 1024 * 8; 437 break; 438 case USB_SPEED_FULL: /* units are frames/msec */ 439 case USB_SPEED_LOW: 440 if (xfertype == USB_ENDPOINT_XFER_INT) { 441 if (urb->interval > 255) 442 return -EINVAL; 443 /* NOTE ohci only handles up to 32 */ 444 max = 128; 445 } else { 446 if (urb->interval > 1024) 447 urb->interval = 1024; 448 /* NOTE usb and ohci handle up to 2^15 */ 449 max = 1024; 450 } 451 break; 452 default: 453 return -EINVAL; 454 } 455 /* Round down to a power of 2, no more than max */ 456 urb->interval = min(max, 1 << ilog2(urb->interval)); 457 } 458 459 return usb_hcd_submit_urb(urb, mem_flags); 460 } 461 EXPORT_SYMBOL_GPL(usb_submit_urb); 462 463 /*-------------------------------------------------------------------*/ 464 465 /** 466 * usb_unlink_urb - abort/cancel a transfer request for an endpoint 467 * @urb: pointer to urb describing a previously submitted request, 468 * may be NULL 469 * 470 * This routine cancels an in-progress request. URBs complete only once 471 * per submission, and may be canceled only once per submission. 472 * Successful cancellation means termination of @urb will be expedited 473 * and the completion handler will be called with a status code 474 * indicating that the request has been canceled (rather than any other 475 * code). 476 * 477 * Drivers should not call this routine or related routines, such as 478 * usb_kill_urb() or usb_unlink_anchored_urbs(), after their disconnect 479 * method has returned. The disconnect function should synchronize with 480 * a driver's I/O routines to insure that all URB-related activity has 481 * completed before it returns. 482 * 483 * This request is always asynchronous. Success is indicated by 484 * returning -EINPROGRESS, at which time the URB will probably not yet 485 * have been given back to the device driver. When it is eventually 486 * called, the completion function will see @urb->status == -ECONNRESET. 487 * Failure is indicated by usb_unlink_urb() returning any other value. 488 * Unlinking will fail when @urb is not currently "linked" (i.e., it was 489 * never submitted, or it was unlinked before, or the hardware is already 490 * finished with it), even if the completion handler has not yet run. 491 * 492 * Unlinking and Endpoint Queues: 493 * 494 * [The behaviors and guarantees described below do not apply to virtual 495 * root hubs but only to endpoint queues for physical USB devices.] 496 * 497 * Host Controller Drivers (HCDs) place all the URBs for a particular 498 * endpoint in a queue. Normally the queue advances as the controller 499 * hardware processes each request. But when an URB terminates with an 500 * error its queue generally stops (see below), at least until that URB's 501 * completion routine returns. It is guaranteed that a stopped queue 502 * will not restart until all its unlinked URBs have been fully retired, 503 * with their completion routines run, even if that's not until some time 504 * after the original completion handler returns. The same behavior and 505 * guarantee apply when an URB terminates because it was unlinked. 506 * 507 * Bulk and interrupt endpoint queues are guaranteed to stop whenever an 508 * URB terminates with any sort of error, including -ECONNRESET, -ENOENT, 509 * and -EREMOTEIO. Control endpoint queues behave the same way except 510 * that they are not guaranteed to stop for -EREMOTEIO errors. Queues 511 * for isochronous endpoints are treated differently, because they must 512 * advance at fixed rates. Such queues do not stop when an URB 513 * encounters an error or is unlinked. An unlinked isochronous URB may 514 * leave a gap in the stream of packets; it is undefined whether such 515 * gaps can be filled in. 516 * 517 * Note that early termination of an URB because a short packet was 518 * received will generate a -EREMOTEIO error if and only if the 519 * URB_SHORT_NOT_OK flag is set. By setting this flag, USB device 520 * drivers can build deep queues for large or complex bulk transfers 521 * and clean them up reliably after any sort of aborted transfer by 522 * unlinking all pending URBs at the first fault. 523 * 524 * When a control URB terminates with an error other than -EREMOTEIO, it 525 * is quite likely that the status stage of the transfer will not take 526 * place. 527 */ 528 int usb_unlink_urb(struct urb *urb) 529 { 530 if (!urb) 531 return -EINVAL; 532 if (!urb->dev) 533 return -ENODEV; 534 if (!urb->ep) 535 return -EIDRM; 536 return usb_hcd_unlink_urb(urb, -ECONNRESET); 537 } 538 EXPORT_SYMBOL_GPL(usb_unlink_urb); 539 540 /** 541 * usb_kill_urb - cancel a transfer request and wait for it to finish 542 * @urb: pointer to URB describing a previously submitted request, 543 * may be NULL 544 * 545 * This routine cancels an in-progress request. It is guaranteed that 546 * upon return all completion handlers will have finished and the URB 547 * will be totally idle and available for reuse. These features make 548 * this an ideal way to stop I/O in a disconnect() callback or close() 549 * function. If the request has not already finished or been unlinked 550 * the completion handler will see urb->status == -ENOENT. 551 * 552 * While the routine is running, attempts to resubmit the URB will fail 553 * with error -EPERM. Thus even if the URB's completion handler always 554 * tries to resubmit, it will not succeed and the URB will become idle. 555 * 556 * This routine may not be used in an interrupt context (such as a bottom 557 * half or a completion handler), or when holding a spinlock, or in other 558 * situations where the caller can't schedule(). 559 * 560 * This routine should not be called by a driver after its disconnect 561 * method has returned. 562 */ 563 void usb_kill_urb(struct urb *urb) 564 { 565 might_sleep(); 566 if (!(urb && urb->dev && urb->ep)) 567 return; 568 spin_lock_irq(&usb_reject_lock); 569 ++urb->reject; 570 spin_unlock_irq(&usb_reject_lock); 571 572 usb_hcd_unlink_urb(urb, -ENOENT); 573 wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); 574 575 spin_lock_irq(&usb_reject_lock); 576 --urb->reject; 577 spin_unlock_irq(&usb_reject_lock); 578 } 579 EXPORT_SYMBOL_GPL(usb_kill_urb); 580 581 /** 582 * usb_poison_urb - reliably kill a transfer and prevent further use of an URB 583 * @urb: pointer to URB describing a previously submitted request, 584 * may be NULL 585 * 586 * This routine cancels an in-progress request. It is guaranteed that 587 * upon return all completion handlers will have finished and the URB 588 * will be totally idle and cannot be reused. These features make 589 * this an ideal way to stop I/O in a disconnect() callback. 590 * If the request has not already finished or been unlinked 591 * the completion handler will see urb->status == -ENOENT. 592 * 593 * After and while the routine runs, attempts to resubmit the URB will fail 594 * with error -EPERM. Thus even if the URB's completion handler always 595 * tries to resubmit, it will not succeed and the URB will become idle. 596 * 597 * This routine may not be used in an interrupt context (such as a bottom 598 * half or a completion handler), or when holding a spinlock, or in other 599 * situations where the caller can't schedule(). 600 * 601 * This routine should not be called by a driver after its disconnect 602 * method has returned. 603 */ 604 void usb_poison_urb(struct urb *urb) 605 { 606 might_sleep(); 607 if (!(urb && urb->dev && urb->ep)) 608 return; 609 spin_lock_irq(&usb_reject_lock); 610 ++urb->reject; 611 spin_unlock_irq(&usb_reject_lock); 612 613 usb_hcd_unlink_urb(urb, -ENOENT); 614 wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); 615 } 616 EXPORT_SYMBOL_GPL(usb_poison_urb); 617 618 void usb_unpoison_urb(struct urb *urb) 619 { 620 unsigned long flags; 621 622 if (!urb) 623 return; 624 625 spin_lock_irqsave(&usb_reject_lock, flags); 626 --urb->reject; 627 spin_unlock_irqrestore(&usb_reject_lock, flags); 628 } 629 EXPORT_SYMBOL_GPL(usb_unpoison_urb); 630 631 /** 632 * usb_kill_anchored_urbs - cancel transfer requests en masse 633 * @anchor: anchor the requests are bound to 634 * 635 * this allows all outstanding URBs to be killed starting 636 * from the back of the queue 637 * 638 * This routine should not be called by a driver after its disconnect 639 * method has returned. 640 */ 641 void usb_kill_anchored_urbs(struct usb_anchor *anchor) 642 { 643 struct urb *victim; 644 645 spin_lock_irq(&anchor->lock); 646 while (!list_empty(&anchor->urb_list)) { 647 victim = list_entry(anchor->urb_list.prev, struct urb, 648 anchor_list); 649 /* we must make sure the URB isn't freed before we kill it*/ 650 usb_get_urb(victim); 651 spin_unlock_irq(&anchor->lock); 652 /* this will unanchor the URB */ 653 usb_kill_urb(victim); 654 usb_put_urb(victim); 655 spin_lock_irq(&anchor->lock); 656 } 657 spin_unlock_irq(&anchor->lock); 658 } 659 EXPORT_SYMBOL_GPL(usb_kill_anchored_urbs); 660 661 662 /** 663 * usb_poison_anchored_urbs - cease all traffic from an anchor 664 * @anchor: anchor the requests are bound to 665 * 666 * this allows all outstanding URBs to be poisoned starting 667 * from the back of the queue. Newly added URBs will also be 668 * poisoned 669 * 670 * This routine should not be called by a driver after its disconnect 671 * method has returned. 672 */ 673 void usb_poison_anchored_urbs(struct usb_anchor *anchor) 674 { 675 struct urb *victim; 676 677 spin_lock_irq(&anchor->lock); 678 anchor->poisoned = 1; 679 while (!list_empty(&anchor->urb_list)) { 680 victim = list_entry(anchor->urb_list.prev, struct urb, 681 anchor_list); 682 /* we must make sure the URB isn't freed before we kill it*/ 683 usb_get_urb(victim); 684 spin_unlock_irq(&anchor->lock); 685 /* this will unanchor the URB */ 686 usb_poison_urb(victim); 687 usb_put_urb(victim); 688 spin_lock_irq(&anchor->lock); 689 } 690 spin_unlock_irq(&anchor->lock); 691 } 692 EXPORT_SYMBOL_GPL(usb_poison_anchored_urbs); 693 694 /** 695 * usb_unlink_anchored_urbs - asynchronously cancel transfer requests en masse 696 * @anchor: anchor the requests are bound to 697 * 698 * this allows all outstanding URBs to be unlinked starting 699 * from the back of the queue. This function is asynchronous. 700 * The unlinking is just tiggered. It may happen after this 701 * function has returned. 702 * 703 * This routine should not be called by a driver after its disconnect 704 * method has returned. 705 */ 706 void usb_unlink_anchored_urbs(struct usb_anchor *anchor) 707 { 708 struct urb *victim; 709 unsigned long flags; 710 711 spin_lock_irqsave(&anchor->lock, flags); 712 while (!list_empty(&anchor->urb_list)) { 713 victim = list_entry(anchor->urb_list.prev, struct urb, 714 anchor_list); 715 usb_get_urb(victim); 716 spin_unlock_irqrestore(&anchor->lock, flags); 717 /* this will unanchor the URB */ 718 usb_unlink_urb(victim); 719 usb_put_urb(victim); 720 spin_lock_irqsave(&anchor->lock, flags); 721 } 722 spin_unlock_irqrestore(&anchor->lock, flags); 723 } 724 EXPORT_SYMBOL_GPL(usb_unlink_anchored_urbs); 725 726 /** 727 * usb_wait_anchor_empty_timeout - wait for an anchor to be unused 728 * @anchor: the anchor you want to become unused 729 * @timeout: how long you are willing to wait in milliseconds 730 * 731 * Call this is you want to be sure all an anchor's 732 * URBs have finished 733 */ 734 int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor, 735 unsigned int timeout) 736 { 737 return wait_event_timeout(anchor->wait, list_empty(&anchor->urb_list), 738 msecs_to_jiffies(timeout)); 739 } 740 EXPORT_SYMBOL_GPL(usb_wait_anchor_empty_timeout); 741 742 /** 743 * usb_get_from_anchor - get an anchor's oldest urb 744 * @anchor: the anchor whose urb you want 745 * 746 * this will take the oldest urb from an anchor, 747 * unanchor and return it 748 */ 749 struct urb *usb_get_from_anchor(struct usb_anchor *anchor) 750 { 751 struct urb *victim; 752 unsigned long flags; 753 754 spin_lock_irqsave(&anchor->lock, flags); 755 if (!list_empty(&anchor->urb_list)) { 756 victim = list_entry(anchor->urb_list.next, struct urb, 757 anchor_list); 758 usb_get_urb(victim); 759 spin_unlock_irqrestore(&anchor->lock, flags); 760 usb_unanchor_urb(victim); 761 } else { 762 spin_unlock_irqrestore(&anchor->lock, flags); 763 victim = NULL; 764 } 765 766 return victim; 767 } 768 769 EXPORT_SYMBOL_GPL(usb_get_from_anchor); 770 771 /** 772 * usb_scuttle_anchored_urbs - unanchor all an anchor's urbs 773 * @anchor: the anchor whose urbs you want to unanchor 774 * 775 * use this to get rid of all an anchor's urbs 776 */ 777 void usb_scuttle_anchored_urbs(struct usb_anchor *anchor) 778 { 779 struct urb *victim; 780 unsigned long flags; 781 782 spin_lock_irqsave(&anchor->lock, flags); 783 while (!list_empty(&anchor->urb_list)) { 784 victim = list_entry(anchor->urb_list.prev, struct urb, 785 anchor_list); 786 usb_get_urb(victim); 787 spin_unlock_irqrestore(&anchor->lock, flags); 788 /* this may free the URB */ 789 usb_unanchor_urb(victim); 790 usb_put_urb(victim); 791 spin_lock_irqsave(&anchor->lock, flags); 792 } 793 spin_unlock_irqrestore(&anchor->lock, flags); 794 } 795 796 EXPORT_SYMBOL_GPL(usb_scuttle_anchored_urbs); 797 798 /** 799 * usb_anchor_empty - is an anchor empty 800 * @anchor: the anchor you want to query 801 * 802 * returns 1 if the anchor has no urbs associated with it 803 */ 804 int usb_anchor_empty(struct usb_anchor *anchor) 805 { 806 return list_empty(&anchor->urb_list); 807 } 808 809 EXPORT_SYMBOL_GPL(usb_anchor_empty); 810 811