Branch data Line data Source code
1 : : // SPDX-License-Identifier: GPL-2.0
2 : : /*
3 : : * Released under the GPLv2 only.
4 : : */
5 : :
6 : : #include <linux/module.h>
7 : : #include <linux/string.h>
8 : : #include <linux/bitops.h>
9 : : #include <linux/slab.h>
10 : : #include <linux/log2.h>
11 : : #include <linux/usb.h>
12 : : #include <linux/wait.h>
13 : : #include <linux/usb/hcd.h>
14 : : #include <linux/scatterlist.h>
15 : :
16 : : #define to_urb(d) container_of(d, struct urb, kref)
17 : :
18 : :
19 : 3 : static void urb_destroy(struct kref *kref)
20 : : {
21 : : struct urb *urb = to_urb(kref);
22 : :
23 : 3 : if (urb->transfer_flags & URB_FREE_BUFFER)
24 : 2 : kfree(urb->transfer_buffer);
25 : :
26 : 3 : kfree(urb);
27 : 3 : }
28 : :
29 : : /**
30 : : * usb_init_urb - initializes a urb so that it can be used by a USB driver
31 : : * @urb: pointer to the urb to initialize
32 : : *
33 : : * Initializes a urb so that the USB subsystem can use it properly.
34 : : *
35 : : * If a urb is created with a call to usb_alloc_urb() it is not
36 : : * necessary to call this function. Only use this if you allocate the
37 : : * space for a struct urb on your own. If you call this function, be
38 : : * careful when freeing the memory for your urb that it is no longer in
39 : : * use by the USB core.
40 : : *
41 : : * Only use this function if you _really_ understand what you are doing.
42 : : */
43 : 3 : void usb_init_urb(struct urb *urb)
44 : : {
45 : 3 : if (urb) {
46 : 3 : memset(urb, 0, sizeof(*urb));
47 : : kref_init(&urb->kref);
48 : 3 : INIT_LIST_HEAD(&urb->urb_list);
49 : 3 : INIT_LIST_HEAD(&urb->anchor_list);
50 : : }
51 : 3 : }
52 : : EXPORT_SYMBOL_GPL(usb_init_urb);
53 : :
54 : : /**
55 : : * usb_alloc_urb - creates a new urb for a USB driver to use
56 : : * @iso_packets: number of iso packets for this urb
57 : : * @mem_flags: the type of memory to allocate, see kmalloc() for a list of
58 : : * valid options for this.
59 : : *
60 : : * Creates an urb for the USB driver to use, initializes a few internal
61 : : * structures, increments the usage counter, and returns a pointer to it.
62 : : *
63 : : * If the driver want to use this urb for interrupt, control, or bulk
64 : : * endpoints, pass '0' as the number of iso packets.
65 : : *
66 : : * The driver must call usb_free_urb() when it is finished with the urb.
67 : : *
68 : : * Return: A pointer to the new urb, or %NULL if no memory is available.
69 : : */
70 : 3 : struct urb *usb_alloc_urb(int iso_packets, gfp_t mem_flags)
71 : : {
72 : : struct urb *urb;
73 : :
74 : 3 : urb = kmalloc(struct_size(urb, iso_frame_desc, iso_packets),
75 : : mem_flags);
76 : 3 : if (!urb)
77 : : return NULL;
78 : 3 : usb_init_urb(urb);
79 : 3 : return urb;
80 : : }
81 : : EXPORT_SYMBOL_GPL(usb_alloc_urb);
82 : :
83 : : /**
84 : : * usb_free_urb - frees the memory used by a urb when all users of it are finished
85 : : * @urb: pointer to the urb to free, may be NULL
86 : : *
87 : : * Must be called when a user of a urb is finished with it. When the last user
88 : : * of the urb calls this function, the memory of the urb is freed.
89 : : *
90 : : * Note: The transfer buffer associated with the urb is not freed unless the
91 : : * URB_FREE_BUFFER transfer flag is set.
92 : : */
93 : 3 : void usb_free_urb(struct urb *urb)
94 : : {
95 : 3 : if (urb)
96 : 3 : kref_put(&urb->kref, urb_destroy);
97 : 3 : }
98 : : EXPORT_SYMBOL_GPL(usb_free_urb);
99 : :
100 : : /**
101 : : * usb_get_urb - increments the reference count of the urb
102 : : * @urb: pointer to the urb to modify, may be NULL
103 : : *
104 : : * This must be called whenever a urb is transferred from a device driver to a
105 : : * host controller driver. This allows proper reference counting to happen
106 : : * for urbs.
107 : : *
108 : : * Return: A pointer to the urb with the incremented reference counter.
109 : : */
110 : 3 : struct urb *usb_get_urb(struct urb *urb)
111 : : {
112 : 3 : if (urb)
113 : : kref_get(&urb->kref);
114 : 3 : return urb;
115 : : }
116 : : EXPORT_SYMBOL_GPL(usb_get_urb);
117 : :
118 : : /**
119 : : * usb_anchor_urb - anchors an URB while it is processed
120 : : * @urb: pointer to the urb to anchor
121 : : * @anchor: pointer to the anchor
122 : : *
123 : : * This can be called to have access to URBs which are to be executed
124 : : * without bothering to track them
125 : : */
126 : 0 : void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor)
127 : : {
128 : : unsigned long flags;
129 : :
130 : 0 : spin_lock_irqsave(&anchor->lock, flags);
131 : : usb_get_urb(urb);
132 : 0 : list_add_tail(&urb->anchor_list, &anchor->urb_list);
133 : 0 : urb->anchor = anchor;
134 : :
135 : 0 : if (unlikely(anchor->poisoned))
136 : 0 : atomic_inc(&urb->reject);
137 : :
138 : : spin_unlock_irqrestore(&anchor->lock, flags);
139 : 0 : }
140 : : EXPORT_SYMBOL_GPL(usb_anchor_urb);
141 : :
142 : : static int usb_anchor_check_wakeup(struct usb_anchor *anchor)
143 : : {
144 : 0 : return atomic_read(&anchor->suspend_wakeups) == 0 &&
145 : 0 : list_empty(&anchor->urb_list);
146 : : }
147 : :
148 : : /* Callers must hold anchor->lock */
149 : 0 : static void __usb_unanchor_urb(struct urb *urb, struct usb_anchor *anchor)
150 : : {
151 : 0 : urb->anchor = NULL;
152 : : list_del(&urb->anchor_list);
153 : : usb_put_urb(urb);
154 : 0 : if (usb_anchor_check_wakeup(anchor))
155 : 0 : wake_up(&anchor->wait);
156 : 0 : }
157 : :
158 : : /**
159 : : * usb_unanchor_urb - unanchors an URB
160 : : * @urb: pointer to the urb to anchor
161 : : *
162 : : * Call this to stop the system keeping track of this URB
163 : : */
164 : 3 : void usb_unanchor_urb(struct urb *urb)
165 : : {
166 : : unsigned long flags;
167 : : struct usb_anchor *anchor;
168 : :
169 : 3 : if (!urb)
170 : : return;
171 : :
172 : 3 : anchor = urb->anchor;
173 : 3 : if (!anchor)
174 : : return;
175 : :
176 : 0 : spin_lock_irqsave(&anchor->lock, flags);
177 : : /*
178 : : * At this point, we could be competing with another thread which
179 : : * has the same intention. To protect the urb from being unanchored
180 : : * twice, only the winner of the race gets the job.
181 : : */
182 : 0 : if (likely(anchor == urb->anchor))
183 : 0 : __usb_unanchor_urb(urb, anchor);
184 : : spin_unlock_irqrestore(&anchor->lock, flags);
185 : : }
186 : : EXPORT_SYMBOL_GPL(usb_unanchor_urb);
187 : :
188 : : /*-------------------------------------------------------------------*/
189 : :
190 : : static const int pipetypes[4] = {
191 : : PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT
192 : : };
193 : :
194 : : /**
195 : : * usb_urb_ep_type_check - sanity check of endpoint in the given urb
196 : : * @urb: urb to be checked
197 : : *
198 : : * This performs a light-weight sanity check for the endpoint in the
199 : : * given urb. It returns 0 if the urb contains a valid endpoint, otherwise
200 : : * a negative error code.
201 : : */
202 : 3 : int usb_urb_ep_type_check(const struct urb *urb)
203 : : {
204 : : const struct usb_host_endpoint *ep;
205 : :
206 : 3 : ep = usb_pipe_endpoint(urb->dev, urb->pipe);
207 : 3 : if (!ep)
208 : : return -EINVAL;
209 : 3 : if (usb_pipetype(urb->pipe) != pipetypes[usb_endpoint_type(&ep->desc)])
210 : : return -EINVAL;
211 : 3 : return 0;
212 : : }
213 : : EXPORT_SYMBOL_GPL(usb_urb_ep_type_check);
214 : :
215 : : /**
216 : : * usb_submit_urb - issue an asynchronous transfer request for an endpoint
217 : : * @urb: pointer to the urb describing the request
218 : : * @mem_flags: the type of memory to allocate, see kmalloc() for a list
219 : : * of valid options for this.
220 : : *
221 : : * This submits a transfer request, and transfers control of the URB
222 : : * describing that request to the USB subsystem. Request completion will
223 : : * be indicated later, asynchronously, by calling the completion handler.
224 : : * The three types of completion are success, error, and unlink
225 : : * (a software-induced fault, also called "request cancellation").
226 : : *
227 : : * URBs may be submitted in interrupt context.
228 : : *
229 : : * The caller must have correctly initialized the URB before submitting
230 : : * it. Functions such as usb_fill_bulk_urb() and usb_fill_control_urb() are
231 : : * available to ensure that most fields are correctly initialized, for
232 : : * the particular kind of transfer, although they will not initialize
233 : : * any transfer flags.
234 : : *
235 : : * If the submission is successful, the complete() callback from the URB
236 : : * will be called exactly once, when the USB core and Host Controller Driver
237 : : * (HCD) are finished with the URB. When the completion function is called,
238 : : * control of the URB is returned to the device driver which issued the
239 : : * request. The completion handler may then immediately free or reuse that
240 : : * URB.
241 : : *
242 : : * With few exceptions, USB device drivers should never access URB fields
243 : : * provided by usbcore or the HCD until its complete() is called.
244 : : * The exceptions relate to periodic transfer scheduling. For both
245 : : * interrupt and isochronous urbs, as part of successful URB submission
246 : : * urb->interval is modified to reflect the actual transfer period used
247 : : * (normally some power of two units). And for isochronous urbs,
248 : : * urb->start_frame is modified to reflect when the URB's transfers were
249 : : * scheduled to start.
250 : : *
251 : : * Not all isochronous transfer scheduling policies will work, but most
252 : : * host controller drivers should easily handle ISO queues going from now
253 : : * until 10-200 msec into the future. Drivers should try to keep at
254 : : * least one or two msec of data in the queue; many controllers require
255 : : * that new transfers start at least 1 msec in the future when they are
256 : : * added. If the driver is unable to keep up and the queue empties out,
257 : : * the behavior for new submissions is governed by the URB_ISO_ASAP flag.
258 : : * If the flag is set, or if the queue is idle, then the URB is always
259 : : * assigned to the first available (and not yet expired) slot in the
260 : : * endpoint's schedule. If the flag is not set and the queue is active
261 : : * then the URB is always assigned to the next slot in the schedule
262 : : * following the end of the endpoint's previous URB, even if that slot is
263 : : * in the past. When a packet is assigned in this way to a slot that has
264 : : * already expired, the packet is not transmitted and the corresponding
265 : : * usb_iso_packet_descriptor's status field will return -EXDEV. If this
266 : : * would happen to all the packets in the URB, submission fails with a
267 : : * -EXDEV error code.
268 : : *
269 : : * For control endpoints, the synchronous usb_control_msg() call is
270 : : * often used (in non-interrupt context) instead of this call.
271 : : * That is often used through convenience wrappers, for the requests
272 : : * that are standardized in the USB 2.0 specification. For bulk
273 : : * endpoints, a synchronous usb_bulk_msg() call is available.
274 : : *
275 : : * Return:
276 : : * 0 on successful submissions. A negative error number otherwise.
277 : : *
278 : : * Request Queuing:
279 : : *
280 : : * URBs may be submitted to endpoints before previous ones complete, to
281 : : * minimize the impact of interrupt latencies and system overhead on data
282 : : * throughput. With that queuing policy, an endpoint's queue would never
283 : : * be empty. This is required for continuous isochronous data streams,
284 : : * and may also be required for some kinds of interrupt transfers. Such
285 : : * queuing also maximizes bandwidth utilization by letting USB controllers
286 : : * start work on later requests before driver software has finished the
287 : : * completion processing for earlier (successful) requests.
288 : : *
289 : : * As of Linux 2.6, all USB endpoint transfer queues support depths greater
290 : : * than one. This was previously a HCD-specific behavior, except for ISO
291 : : * transfers. Non-isochronous endpoint queues are inactive during cleanup
292 : : * after faults (transfer errors or cancellation).
293 : : *
294 : : * Reserved Bandwidth Transfers:
295 : : *
296 : : * Periodic transfers (interrupt or isochronous) are performed repeatedly,
297 : : * using the interval specified in the urb. Submitting the first urb to
298 : : * the endpoint reserves the bandwidth necessary to make those transfers.
299 : : * If the USB subsystem can't allocate sufficient bandwidth to perform
300 : : * the periodic request, submitting such a periodic request should fail.
301 : : *
302 : : * For devices under xHCI, the bandwidth is reserved at configuration time, or
303 : : * when the alt setting is selected. If there is not enough bus bandwidth, the
304 : : * configuration/alt setting request will fail. Therefore, submissions to
305 : : * periodic endpoints on devices under xHCI should never fail due to bandwidth
306 : : * constraints.
307 : : *
308 : : * Device drivers must explicitly request that repetition, by ensuring that
309 : : * some URB is always on the endpoint's queue (except possibly for short
310 : : * periods during completion callbacks). When there is no longer an urb
311 : : * queued, the endpoint's bandwidth reservation is canceled. This means
312 : : * drivers can use their completion handlers to ensure they keep bandwidth
313 : : * they need, by reinitializing and resubmitting the just-completed urb
314 : : * until the driver longer needs that periodic bandwidth.
315 : : *
316 : : * Memory Flags:
317 : : *
318 : : * The general rules for how to decide which mem_flags to use
319 : : * are the same as for kmalloc. There are four
320 : : * different possible values; GFP_KERNEL, GFP_NOFS, GFP_NOIO and
321 : : * GFP_ATOMIC.
322 : : *
323 : : * GFP_NOFS is not ever used, as it has not been implemented yet.
324 : : *
325 : : * GFP_ATOMIC is used when
326 : : * (a) you are inside a completion handler, an interrupt, bottom half,
327 : : * tasklet or timer, or
328 : : * (b) you are holding a spinlock or rwlock (does not apply to
329 : : * semaphores), or
330 : : * (c) current->state != TASK_RUNNING, this is the case only after
331 : : * you've changed it.
332 : : *
333 : : * GFP_NOIO is used in the block io path and error handling of storage
334 : : * devices.
335 : : *
336 : : * All other situations use GFP_KERNEL.
337 : : *
338 : : * Some more specific rules for mem_flags can be inferred, such as
339 : : * (1) start_xmit, timeout, and receive methods of network drivers must
340 : : * use GFP_ATOMIC (they are called with a spinlock held);
341 : : * (2) queuecommand methods of scsi drivers must use GFP_ATOMIC (also
342 : : * called with a spinlock held);
343 : : * (3) If you use a kernel thread with a network driver you must use
344 : : * GFP_NOIO, unless (b) or (c) apply;
345 : : * (4) after you have done a down() you can use GFP_KERNEL, unless (b) or (c)
346 : : * apply or your are in a storage driver's block io path;
347 : : * (5) USB probe and disconnect can use GFP_KERNEL unless (b) or (c) apply; and
348 : : * (6) changing firmware on a running storage or net device uses
349 : : * GFP_NOIO, unless b) or c) apply
350 : : *
351 : : */
352 : 3 : int usb_submit_urb(struct urb *urb, gfp_t mem_flags)
353 : : {
354 : : int xfertype, max;
355 : : struct usb_device *dev;
356 : : struct usb_host_endpoint *ep;
357 : : int is_out;
358 : : unsigned int allowed;
359 : :
360 : 3 : if (!urb || !urb->complete)
361 : : return -EINVAL;
362 : 3 : if (urb->hcpriv) {
363 : 0 : WARN_ONCE(1, "URB %pK submitted while active\n", urb);
364 : : return -EBUSY;
365 : : }
366 : :
367 : 3 : dev = urb->dev;
368 : 3 : if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
369 : : return -ENODEV;
370 : :
371 : : /* For now, get the endpoint from the pipe. Eventually drivers
372 : : * will be required to set urb->ep directly and we will eliminate
373 : : * urb->pipe.
374 : : */
375 : 3 : ep = usb_pipe_endpoint(dev, urb->pipe);
376 : 3 : if (!ep)
377 : : return -ENOENT;
378 : :
379 : 3 : urb->ep = ep;
380 : 3 : urb->status = -EINPROGRESS;
381 : 3 : urb->actual_length = 0;
382 : :
383 : : /* Lots of sanity checks, so HCDs can rely on clean data
384 : : * and don't need to duplicate tests
385 : : */
386 : : xfertype = usb_endpoint_type(&ep->desc);
387 : 3 : if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
388 : 3 : struct usb_ctrlrequest *setup =
389 : : (struct usb_ctrlrequest *) urb->setup_packet;
390 : :
391 : 3 : if (!setup)
392 : : return -ENOEXEC;
393 : 3 : is_out = !(setup->bRequestType & USB_DIR_IN) ||
394 : 3 : !setup->wLength;
395 : : } else {
396 : : is_out = usb_endpoint_dir_out(&ep->desc);
397 : : }
398 : :
399 : : /* Clear the internal flags and cache the direction for later use */
400 : 3 : urb->transfer_flags &= ~(URB_DIR_MASK | URB_DMA_MAP_SINGLE |
401 : : URB_DMA_MAP_PAGE | URB_DMA_MAP_SG | URB_MAP_LOCAL |
402 : : URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL |
403 : : URB_DMA_SG_COMBINED);
404 : 3 : urb->transfer_flags |= (is_out ? URB_DIR_OUT : URB_DIR_IN);
405 : :
406 : 3 : if (xfertype != USB_ENDPOINT_XFER_CONTROL &&
407 : 3 : dev->state < USB_STATE_CONFIGURED)
408 : : return -ENODEV;
409 : :
410 : : max = usb_endpoint_maxp(&ep->desc);
411 : 3 : if (max <= 0) {
412 : : dev_dbg(&dev->dev,
413 : : "bogus endpoint ep%d%s in %s (bad maxpacket %d)\n",
414 : : usb_endpoint_num(&ep->desc), is_out ? "out" : "in",
415 : : __func__, max);
416 : : return -EMSGSIZE;
417 : : }
418 : :
419 : : /* periodic transfers limit size per frame/uframe,
420 : : * but drivers only control those sizes for ISO.
421 : : * while we're checking, initialize return status.
422 : : */
423 : 3 : if (xfertype == USB_ENDPOINT_XFER_ISOC) {
424 : : int n, len;
425 : :
426 : : /* SuperSpeed isoc endpoints have up to 16 bursts of up to
427 : : * 3 packets each
428 : : */
429 : 0 : if (dev->speed >= USB_SPEED_SUPER) {
430 : 0 : int burst = 1 + ep->ss_ep_comp.bMaxBurst;
431 : 0 : int mult = USB_SS_MULT(ep->ss_ep_comp.bmAttributes);
432 : 0 : max *= burst;
433 : 0 : max *= mult;
434 : : }
435 : :
436 : 0 : if (dev->speed == USB_SPEED_SUPER_PLUS &&
437 : 0 : USB_SS_SSP_ISOC_COMP(ep->ss_ep_comp.bmAttributes)) {
438 : : struct usb_ssp_isoc_ep_comp_descriptor *isoc_ep_comp;
439 : :
440 : : isoc_ep_comp = &ep->ssp_isoc_ep_comp;
441 : 0 : max = le32_to_cpu(isoc_ep_comp->dwBytesPerInterval);
442 : : }
443 : :
444 : : /* "high bandwidth" mode, 1-3 packets/uframe? */
445 : 0 : if (dev->speed == USB_SPEED_HIGH)
446 : 0 : max *= usb_endpoint_maxp_mult(&ep->desc);
447 : :
448 : 0 : if (urb->number_of_packets <= 0)
449 : : return -EINVAL;
450 : 0 : for (n = 0; n < urb->number_of_packets; n++) {
451 : 0 : len = urb->iso_frame_desc[n].length;
452 : 0 : if (len < 0 || len > max)
453 : : return -EMSGSIZE;
454 : 0 : urb->iso_frame_desc[n].status = -EXDEV;
455 : 0 : urb->iso_frame_desc[n].actual_length = 0;
456 : : }
457 : 3 : } else if (urb->num_sgs && !urb->dev->bus->no_sg_constraint &&
458 : 0 : dev->speed != USB_SPEED_WIRELESS) {
459 : : struct scatterlist *sg;
460 : : int i;
461 : :
462 : 0 : for_each_sg(urb->sg, sg, urb->num_sgs - 1, i)
463 : 0 : if (sg->length % max)
464 : : return -EINVAL;
465 : : }
466 : :
467 : : /* the I/O buffer must be mapped/unmapped, except when length=0 */
468 : 3 : if (urb->transfer_buffer_length > INT_MAX)
469 : : return -EMSGSIZE;
470 : :
471 : : /*
472 : : * stuff that drivers shouldn't do, but which shouldn't
473 : : * cause problems in HCDs if they get it wrong.
474 : : */
475 : :
476 : : /* Check that the pipe's type matches the endpoint's type */
477 : 3 : if (usb_urb_ep_type_check(urb))
478 : 0 : dev_WARN(&dev->dev, "BOGUS urb xfer, pipe %x != type %x\n",
479 : : usb_pipetype(urb->pipe), pipetypes[xfertype]);
480 : :
481 : : /* Check against a simple/standard policy */
482 : : allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT | URB_DIR_MASK |
483 : : URB_FREE_BUFFER);
484 : 3 : switch (xfertype) {
485 : : case USB_ENDPOINT_XFER_BULK:
486 : : case USB_ENDPOINT_XFER_INT:
487 : 3 : if (is_out)
488 : : allowed |= URB_ZERO_PACKET;
489 : : /* FALLTHROUGH */
490 : : default: /* all non-iso endpoints */
491 : 3 : if (!is_out)
492 : 3 : allowed |= URB_SHORT_NOT_OK;
493 : : break;
494 : : case USB_ENDPOINT_XFER_ISOC:
495 : : allowed |= URB_ISO_ASAP;
496 : : break;
497 : : }
498 : 3 : allowed &= urb->transfer_flags;
499 : :
500 : : /* warn if submitter gave bogus flags */
501 : 3 : if (allowed != urb->transfer_flags)
502 : 0 : dev_WARN(&dev->dev, "BOGUS urb flags, %x --> %x\n",
503 : : urb->transfer_flags, allowed);
504 : :
505 : : /*
506 : : * Force periodic transfer intervals to be legal values that are
507 : : * a power of two (so HCDs don't need to).
508 : : *
509 : : * FIXME want bus->{intr,iso}_sched_horizon values here. Each HC
510 : : * supports different values... this uses EHCI/UHCI defaults (and
511 : : * EHCI can use smaller non-default values).
512 : : */
513 : 3 : switch (xfertype) {
514 : : case USB_ENDPOINT_XFER_ISOC:
515 : : case USB_ENDPOINT_XFER_INT:
516 : : /* too small? */
517 : 3 : switch (dev->speed) {
518 : : case USB_SPEED_WIRELESS:
519 : 0 : if ((urb->interval < 6)
520 : 0 : && (xfertype == USB_ENDPOINT_XFER_INT))
521 : : return -EINVAL;
522 : : /* fall through */
523 : : default:
524 : 3 : if (urb->interval <= 0)
525 : : return -EINVAL;
526 : : break;
527 : : }
528 : : /* too big? */
529 : 3 : switch (dev->speed) {
530 : : case USB_SPEED_SUPER_PLUS:
531 : : case USB_SPEED_SUPER: /* units are 125us */
532 : : /* Handle up to 2^(16-1) microframes */
533 : 0 : if (urb->interval > (1 << 15))
534 : : return -EINVAL;
535 : : max = 1 << 15;
536 : : break;
537 : : case USB_SPEED_WIRELESS:
538 : 0 : if (urb->interval > 16)
539 : : return -EINVAL;
540 : : break;
541 : : case USB_SPEED_HIGH: /* units are microframes */
542 : : /* NOTE usb handles 2^15 */
543 : 3 : if (urb->interval > (1024 * 8))
544 : 0 : urb->interval = 1024 * 8;
545 : : max = 1024 * 8;
546 : : break;
547 : : case USB_SPEED_FULL: /* units are frames/msec */
548 : : case USB_SPEED_LOW:
549 : 3 : if (xfertype == USB_ENDPOINT_XFER_INT) {
550 : 3 : if (urb->interval > 255)
551 : : return -EINVAL;
552 : : /* NOTE ohci only handles up to 32 */
553 : : max = 128;
554 : : } else {
555 : 0 : if (urb->interval > 1024)
556 : 0 : urb->interval = 1024;
557 : : /* NOTE usb and ohci handle up to 2^15 */
558 : : max = 1024;
559 : : }
560 : : break;
561 : : default:
562 : : return -EINVAL;
563 : : }
564 : 3 : if (dev->speed != USB_SPEED_WIRELESS) {
565 : : /* Round down to a power of 2, no more than max */
566 : 3 : urb->interval = min(max, 1 << ilog2(urb->interval));
567 : : }
568 : : }
569 : :
570 : 3 : return usb_hcd_submit_urb(urb, mem_flags);
571 : : }
572 : : EXPORT_SYMBOL_GPL(usb_submit_urb);
573 : :
574 : : /*-------------------------------------------------------------------*/
575 : :
576 : : /**
577 : : * usb_unlink_urb - abort/cancel a transfer request for an endpoint
578 : : * @urb: pointer to urb describing a previously submitted request,
579 : : * may be NULL
580 : : *
581 : : * This routine cancels an in-progress request. URBs complete only once
582 : : * per submission, and may be canceled only once per submission.
583 : : * Successful cancellation means termination of @urb will be expedited
584 : : * and the completion handler will be called with a status code
585 : : * indicating that the request has been canceled (rather than any other
586 : : * code).
587 : : *
588 : : * Drivers should not call this routine or related routines, such as
589 : : * usb_kill_urb() or usb_unlink_anchored_urbs(), after their disconnect
590 : : * method has returned. The disconnect function should synchronize with
591 : : * a driver's I/O routines to insure that all URB-related activity has
592 : : * completed before it returns.
593 : : *
594 : : * This request is asynchronous, however the HCD might call the ->complete()
595 : : * callback during unlink. Therefore when drivers call usb_unlink_urb(), they
596 : : * must not hold any locks that may be taken by the completion function.
597 : : * Success is indicated by returning -EINPROGRESS, at which time the URB will
598 : : * probably not yet have been given back to the device driver. When it is
599 : : * eventually called, the completion function will see @urb->status ==
600 : : * -ECONNRESET.
601 : : * Failure is indicated by usb_unlink_urb() returning any other value.
602 : : * Unlinking will fail when @urb is not currently "linked" (i.e., it was
603 : : * never submitted, or it was unlinked before, or the hardware is already
604 : : * finished with it), even if the completion handler has not yet run.
605 : : *
606 : : * The URB must not be deallocated while this routine is running. In
607 : : * particular, when a driver calls this routine, it must insure that the
608 : : * completion handler cannot deallocate the URB.
609 : : *
610 : : * Return: -EINPROGRESS on success. See description for other values on
611 : : * failure.
612 : : *
613 : : * Unlinking and Endpoint Queues:
614 : : *
615 : : * [The behaviors and guarantees described below do not apply to virtual
616 : : * root hubs but only to endpoint queues for physical USB devices.]
617 : : *
618 : : * Host Controller Drivers (HCDs) place all the URBs for a particular
619 : : * endpoint in a queue. Normally the queue advances as the controller
620 : : * hardware processes each request. But when an URB terminates with an
621 : : * error its queue generally stops (see below), at least until that URB's
622 : : * completion routine returns. It is guaranteed that a stopped queue
623 : : * will not restart until all its unlinked URBs have been fully retired,
624 : : * with their completion routines run, even if that's not until some time
625 : : * after the original completion handler returns. The same behavior and
626 : : * guarantee apply when an URB terminates because it was unlinked.
627 : : *
628 : : * Bulk and interrupt endpoint queues are guaranteed to stop whenever an
629 : : * URB terminates with any sort of error, including -ECONNRESET, -ENOENT,
630 : : * and -EREMOTEIO. Control endpoint queues behave the same way except
631 : : * that they are not guaranteed to stop for -EREMOTEIO errors. Queues
632 : : * for isochronous endpoints are treated differently, because they must
633 : : * advance at fixed rates. Such queues do not stop when an URB
634 : : * encounters an error or is unlinked. An unlinked isochronous URB may
635 : : * leave a gap in the stream of packets; it is undefined whether such
636 : : * gaps can be filled in.
637 : : *
638 : : * Note that early termination of an URB because a short packet was
639 : : * received will generate a -EREMOTEIO error if and only if the
640 : : * URB_SHORT_NOT_OK flag is set. By setting this flag, USB device
641 : : * drivers can build deep queues for large or complex bulk transfers
642 : : * and clean them up reliably after any sort of aborted transfer by
643 : : * unlinking all pending URBs at the first fault.
644 : : *
645 : : * When a control URB terminates with an error other than -EREMOTEIO, it
646 : : * is quite likely that the status stage of the transfer will not take
647 : : * place.
648 : : */
649 : 2 : int usb_unlink_urb(struct urb *urb)
650 : : {
651 : 2 : if (!urb)
652 : : return -EINVAL;
653 : 2 : if (!urb->dev)
654 : : return -ENODEV;
655 : 2 : if (!urb->ep)
656 : : return -EIDRM;
657 : 2 : return usb_hcd_unlink_urb(urb, -ECONNRESET);
658 : : }
659 : : EXPORT_SYMBOL_GPL(usb_unlink_urb);
660 : :
661 : : /**
662 : : * usb_kill_urb - cancel a transfer request and wait for it to finish
663 : : * @urb: pointer to URB describing a previously submitted request,
664 : : * may be NULL
665 : : *
666 : : * This routine cancels an in-progress request. It is guaranteed that
667 : : * upon return all completion handlers will have finished and the URB
668 : : * will be totally idle and available for reuse. These features make
669 : : * this an ideal way to stop I/O in a disconnect() callback or close()
670 : : * function. If the request has not already finished or been unlinked
671 : : * the completion handler will see urb->status == -ENOENT.
672 : : *
673 : : * While the routine is running, attempts to resubmit the URB will fail
674 : : * with error -EPERM. Thus even if the URB's completion handler always
675 : : * tries to resubmit, it will not succeed and the URB will become idle.
676 : : *
677 : : * The URB must not be deallocated while this routine is running. In
678 : : * particular, when a driver calls this routine, it must insure that the
679 : : * completion handler cannot deallocate the URB.
680 : : *
681 : : * This routine may not be used in an interrupt context (such as a bottom
682 : : * half or a completion handler), or when holding a spinlock, or in other
683 : : * situations where the caller can't schedule().
684 : : *
685 : : * This routine should not be called by a driver after its disconnect
686 : : * method has returned.
687 : : */
688 : 1 : void usb_kill_urb(struct urb *urb)
689 : : {
690 : 1 : might_sleep();
691 : 1 : if (!(urb && urb->dev && urb->ep))
692 : 1 : return;
693 : 1 : atomic_inc(&urb->reject);
694 : :
695 : 1 : usb_hcd_unlink_urb(urb, -ENOENT);
696 : 1 : wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0);
697 : :
698 : : atomic_dec(&urb->reject);
699 : : }
700 : : EXPORT_SYMBOL_GPL(usb_kill_urb);
701 : :
702 : : /**
703 : : * usb_poison_urb - reliably kill a transfer and prevent further use of an URB
704 : : * @urb: pointer to URB describing a previously submitted request,
705 : : * may be NULL
706 : : *
707 : : * This routine cancels an in-progress request. It is guaranteed that
708 : : * upon return all completion handlers will have finished and the URB
709 : : * will be totally idle and cannot be reused. These features make
710 : : * this an ideal way to stop I/O in a disconnect() callback.
711 : : * If the request has not already finished or been unlinked
712 : : * the completion handler will see urb->status == -ENOENT.
713 : : *
714 : : * After and while the routine runs, attempts to resubmit the URB will fail
715 : : * with error -EPERM. Thus even if the URB's completion handler always
716 : : * tries to resubmit, it will not succeed and the URB will become idle.
717 : : *
718 : : * The URB must not be deallocated while this routine is running. In
719 : : * particular, when a driver calls this routine, it must insure that the
720 : : * completion handler cannot deallocate the URB.
721 : : *
722 : : * This routine may not be used in an interrupt context (such as a bottom
723 : : * half or a completion handler), or when holding a spinlock, or in other
724 : : * situations where the caller can't schedule().
725 : : *
726 : : * This routine should not be called by a driver after its disconnect
727 : : * method has returned.
728 : : */
729 : 0 : void usb_poison_urb(struct urb *urb)
730 : : {
731 : 0 : might_sleep();
732 : 0 : if (!urb)
733 : : return;
734 : 0 : atomic_inc(&urb->reject);
735 : :
736 : 0 : if (!urb->dev || !urb->ep)
737 : : return;
738 : :
739 : 0 : usb_hcd_unlink_urb(urb, -ENOENT);
740 : 0 : wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0);
741 : : }
742 : : EXPORT_SYMBOL_GPL(usb_poison_urb);
743 : :
744 : 0 : void usb_unpoison_urb(struct urb *urb)
745 : : {
746 : 0 : if (!urb)
747 : 0 : return;
748 : :
749 : 0 : atomic_dec(&urb->reject);
750 : : }
751 : : EXPORT_SYMBOL_GPL(usb_unpoison_urb);
752 : :
753 : : /**
754 : : * usb_block_urb - reliably prevent further use of an URB
755 : : * @urb: pointer to URB to be blocked, may be NULL
756 : : *
757 : : * After the routine has run, attempts to resubmit the URB will fail
758 : : * with error -EPERM. Thus even if the URB's completion handler always
759 : : * tries to resubmit, it will not succeed and the URB will become idle.
760 : : *
761 : : * The URB must not be deallocated while this routine is running. In
762 : : * particular, when a driver calls this routine, it must insure that the
763 : : * completion handler cannot deallocate the URB.
764 : : */
765 : 0 : void usb_block_urb(struct urb *urb)
766 : : {
767 : 0 : if (!urb)
768 : 0 : return;
769 : :
770 : 0 : atomic_inc(&urb->reject);
771 : : }
772 : : EXPORT_SYMBOL_GPL(usb_block_urb);
773 : :
774 : : /**
775 : : * usb_kill_anchored_urbs - cancel transfer requests en masse
776 : : * @anchor: anchor the requests are bound to
777 : : *
778 : : * this allows all outstanding URBs to be killed starting
779 : : * from the back of the queue
780 : : *
781 : : * This routine should not be called by a driver after its disconnect
782 : : * method has returned.
783 : : */
784 : 0 : void usb_kill_anchored_urbs(struct usb_anchor *anchor)
785 : : {
786 : : struct urb *victim;
787 : :
788 : : spin_lock_irq(&anchor->lock);
789 : 0 : while (!list_empty(&anchor->urb_list)) {
790 : 0 : victim = list_entry(anchor->urb_list.prev, struct urb,
791 : : anchor_list);
792 : : /* we must make sure the URB isn't freed before we kill it*/
793 : : usb_get_urb(victim);
794 : : spin_unlock_irq(&anchor->lock);
795 : : /* this will unanchor the URB */
796 : 0 : usb_kill_urb(victim);
797 : : usb_put_urb(victim);
798 : : spin_lock_irq(&anchor->lock);
799 : : }
800 : : spin_unlock_irq(&anchor->lock);
801 : 0 : }
802 : : EXPORT_SYMBOL_GPL(usb_kill_anchored_urbs);
803 : :
804 : :
805 : : /**
806 : : * usb_poison_anchored_urbs - cease all traffic from an anchor
807 : : * @anchor: anchor the requests are bound to
808 : : *
809 : : * this allows all outstanding URBs to be poisoned starting
810 : : * from the back of the queue. Newly added URBs will also be
811 : : * poisoned
812 : : *
813 : : * This routine should not be called by a driver after its disconnect
814 : : * method has returned.
815 : : */
816 : 0 : void usb_poison_anchored_urbs(struct usb_anchor *anchor)
817 : : {
818 : : struct urb *victim;
819 : :
820 : : spin_lock_irq(&anchor->lock);
821 : 0 : anchor->poisoned = 1;
822 : 0 : while (!list_empty(&anchor->urb_list)) {
823 : 0 : victim = list_entry(anchor->urb_list.prev, struct urb,
824 : : anchor_list);
825 : : /* we must make sure the URB isn't freed before we kill it*/
826 : : usb_get_urb(victim);
827 : : spin_unlock_irq(&anchor->lock);
828 : : /* this will unanchor the URB */
829 : 0 : usb_poison_urb(victim);
830 : : usb_put_urb(victim);
831 : : spin_lock_irq(&anchor->lock);
832 : : }
833 : : spin_unlock_irq(&anchor->lock);
834 : 0 : }
835 : : EXPORT_SYMBOL_GPL(usb_poison_anchored_urbs);
836 : :
837 : : /**
838 : : * usb_unpoison_anchored_urbs - let an anchor be used successfully again
839 : : * @anchor: anchor the requests are bound to
840 : : *
841 : : * Reverses the effect of usb_poison_anchored_urbs
842 : : * the anchor can be used normally after it returns
843 : : */
844 : 0 : void usb_unpoison_anchored_urbs(struct usb_anchor *anchor)
845 : : {
846 : : unsigned long flags;
847 : : struct urb *lazarus;
848 : :
849 : 0 : spin_lock_irqsave(&anchor->lock, flags);
850 : 0 : list_for_each_entry(lazarus, &anchor->urb_list, anchor_list) {
851 : 0 : usb_unpoison_urb(lazarus);
852 : : }
853 : 0 : anchor->poisoned = 0;
854 : : spin_unlock_irqrestore(&anchor->lock, flags);
855 : 0 : }
856 : : EXPORT_SYMBOL_GPL(usb_unpoison_anchored_urbs);
857 : : /**
858 : : * usb_unlink_anchored_urbs - asynchronously cancel transfer requests en masse
859 : : * @anchor: anchor the requests are bound to
860 : : *
861 : : * this allows all outstanding URBs to be unlinked starting
862 : : * from the back of the queue. This function is asynchronous.
863 : : * The unlinking is just triggered. It may happen after this
864 : : * function has returned.
865 : : *
866 : : * This routine should not be called by a driver after its disconnect
867 : : * method has returned.
868 : : */
869 : 0 : void usb_unlink_anchored_urbs(struct usb_anchor *anchor)
870 : : {
871 : : struct urb *victim;
872 : :
873 : 0 : while ((victim = usb_get_from_anchor(anchor)) != NULL) {
874 : 0 : usb_unlink_urb(victim);
875 : : usb_put_urb(victim);
876 : : }
877 : 0 : }
878 : : EXPORT_SYMBOL_GPL(usb_unlink_anchored_urbs);
879 : :
880 : : /**
881 : : * usb_anchor_suspend_wakeups
882 : : * @anchor: the anchor you want to suspend wakeups on
883 : : *
884 : : * Call this to stop the last urb being unanchored from waking up any
885 : : * usb_wait_anchor_empty_timeout waiters. This is used in the hcd urb give-
886 : : * back path to delay waking up until after the completion handler has run.
887 : : */
888 : 3 : void usb_anchor_suspend_wakeups(struct usb_anchor *anchor)
889 : : {
890 : 3 : if (anchor)
891 : 0 : atomic_inc(&anchor->suspend_wakeups);
892 : 3 : }
893 : : EXPORT_SYMBOL_GPL(usb_anchor_suspend_wakeups);
894 : :
895 : : /**
896 : : * usb_anchor_resume_wakeups
897 : : * @anchor: the anchor you want to resume wakeups on
898 : : *
899 : : * Allow usb_wait_anchor_empty_timeout waiters to be woken up again, and
900 : : * wake up any current waiters if the anchor is empty.
901 : : */
902 : 3 : void usb_anchor_resume_wakeups(struct usb_anchor *anchor)
903 : : {
904 : 3 : if (!anchor)
905 : 3 : return;
906 : :
907 : 0 : atomic_dec(&anchor->suspend_wakeups);
908 : 0 : if (usb_anchor_check_wakeup(anchor))
909 : 0 : wake_up(&anchor->wait);
910 : : }
911 : : EXPORT_SYMBOL_GPL(usb_anchor_resume_wakeups);
912 : :
913 : : /**
914 : : * usb_wait_anchor_empty_timeout - wait for an anchor to be unused
915 : : * @anchor: the anchor you want to become unused
916 : : * @timeout: how long you are willing to wait in milliseconds
917 : : *
918 : : * Call this is you want to be sure all an anchor's
919 : : * URBs have finished
920 : : *
921 : : * Return: Non-zero if the anchor became unused. Zero on timeout.
922 : : */
923 : 0 : int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor,
924 : : unsigned int timeout)
925 : : {
926 : 0 : return wait_event_timeout(anchor->wait,
927 : : usb_anchor_check_wakeup(anchor),
928 : : msecs_to_jiffies(timeout));
929 : : }
930 : : EXPORT_SYMBOL_GPL(usb_wait_anchor_empty_timeout);
931 : :
932 : : /**
933 : : * usb_get_from_anchor - get an anchor's oldest urb
934 : : * @anchor: the anchor whose urb you want
935 : : *
936 : : * This will take the oldest urb from an anchor,
937 : : * unanchor and return it
938 : : *
939 : : * Return: The oldest urb from @anchor, or %NULL if @anchor has no
940 : : * urbs associated with it.
941 : : */
942 : 0 : struct urb *usb_get_from_anchor(struct usb_anchor *anchor)
943 : : {
944 : : struct urb *victim;
945 : : unsigned long flags;
946 : :
947 : 0 : spin_lock_irqsave(&anchor->lock, flags);
948 : 0 : if (!list_empty(&anchor->urb_list)) {
949 : 0 : victim = list_entry(anchor->urb_list.next, struct urb,
950 : : anchor_list);
951 : : usb_get_urb(victim);
952 : 0 : __usb_unanchor_urb(victim, anchor);
953 : : } else {
954 : : victim = NULL;
955 : : }
956 : : spin_unlock_irqrestore(&anchor->lock, flags);
957 : :
958 : 0 : return victim;
959 : : }
960 : :
961 : : EXPORT_SYMBOL_GPL(usb_get_from_anchor);
962 : :
963 : : /**
964 : : * usb_scuttle_anchored_urbs - unanchor all an anchor's urbs
965 : : * @anchor: the anchor whose urbs you want to unanchor
966 : : *
967 : : * use this to get rid of all an anchor's urbs
968 : : */
969 : 0 : void usb_scuttle_anchored_urbs(struct usb_anchor *anchor)
970 : : {
971 : : struct urb *victim;
972 : : unsigned long flags;
973 : :
974 : 0 : spin_lock_irqsave(&anchor->lock, flags);
975 : 0 : while (!list_empty(&anchor->urb_list)) {
976 : 0 : victim = list_entry(anchor->urb_list.prev, struct urb,
977 : : anchor_list);
978 : 0 : __usb_unanchor_urb(victim, anchor);
979 : : }
980 : : spin_unlock_irqrestore(&anchor->lock, flags);
981 : 0 : }
982 : :
983 : : EXPORT_SYMBOL_GPL(usb_scuttle_anchored_urbs);
984 : :
985 : : /**
986 : : * usb_anchor_empty - is an anchor empty
987 : : * @anchor: the anchor you want to query
988 : : *
989 : : * Return: 1 if the anchor has no urbs associated with it.
990 : : */
991 : 0 : int usb_anchor_empty(struct usb_anchor *anchor)
992 : : {
993 : 0 : return list_empty(&anchor->urb_list);
994 : : }
995 : :
996 : : EXPORT_SYMBOL_GPL(usb_anchor_empty);
997 : :
|
