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/kmsan.h> |
12 | #include <linux/usb.h> |
13 | #include <linux/wait.h> |
14 | #include <linux/usb/hcd.h> |
15 | #include <linux/scatterlist.h> |
16 | |
17 | #define to_urb(d) container_of(d, struct urb, kref) |
18 | |
19 | |
20 | static void urb_destroy(struct kref *kref) |
21 | { |
22 | struct urb *urb = to_urb(kref); |
23 | |
24 | if (urb->transfer_flags & URB_FREE_BUFFER) |
25 | kfree(objp: urb->transfer_buffer); |
26 | |
27 | kfree(objp: urb); |
28 | } |
29 | |
30 | /** |
31 | * usb_init_urb - initializes a urb so that it can be used by a USB driver |
32 | * @urb: pointer to the urb to initialize |
33 | * |
34 | * Initializes a urb so that the USB subsystem can use it properly. |
35 | * |
36 | * If a urb is created with a call to usb_alloc_urb() it is not |
37 | * necessary to call this function. Only use this if you allocate the |
38 | * space for a struct urb on your own. If you call this function, be |
39 | * careful when freeing the memory for your urb that it is no longer in |
40 | * use by the USB core. |
41 | * |
42 | * Only use this function if you _really_ understand what you are doing. |
43 | */ |
44 | void usb_init_urb(struct urb *urb) |
45 | { |
46 | if (urb) { |
47 | memset(urb, 0, sizeof(*urb)); |
48 | kref_init(kref: &urb->kref); |
49 | INIT_LIST_HEAD(list: &urb->urb_list); |
50 | INIT_LIST_HEAD(list: &urb->anchor_list); |
51 | } |
52 | } |
53 | EXPORT_SYMBOL_GPL(usb_init_urb); |
54 | |
55 | /** |
56 | * usb_alloc_urb - creates a new urb for a USB driver to use |
57 | * @iso_packets: number of iso packets for this urb |
58 | * @mem_flags: the type of memory to allocate, see kmalloc() for a list of |
59 | * valid options for this. |
60 | * |
61 | * Creates an urb for the USB driver to use, initializes a few internal |
62 | * structures, increments the usage counter, and returns a pointer to it. |
63 | * |
64 | * If the driver want to use this urb for interrupt, control, or bulk |
65 | * endpoints, pass '0' as the number of iso packets. |
66 | * |
67 | * The driver must call usb_free_urb() when it is finished with the urb. |
68 | * |
69 | * Return: A pointer to the new urb, or %NULL if no memory is available. |
70 | */ |
71 | struct urb *usb_alloc_urb(int iso_packets, gfp_t mem_flags) |
72 | { |
73 | struct urb *urb; |
74 | |
75 | urb = kmalloc(struct_size(urb, iso_frame_desc, iso_packets), |
76 | flags: mem_flags); |
77 | if (!urb) |
78 | return NULL; |
79 | usb_init_urb(urb); |
80 | return urb; |
81 | } |
82 | EXPORT_SYMBOL_GPL(usb_alloc_urb); |
83 | |
84 | /** |
85 | * usb_free_urb - frees the memory used by a urb when all users of it are finished |
86 | * @urb: pointer to the urb to free, may be NULL |
87 | * |
88 | * Must be called when a user of a urb is finished with it. When the last user |
89 | * of the urb calls this function, the memory of the urb is freed. |
90 | * |
91 | * Note: The transfer buffer associated with the urb is not freed unless the |
92 | * URB_FREE_BUFFER transfer flag is set. |
93 | */ |
94 | void usb_free_urb(struct urb *urb) |
95 | { |
96 | if (urb) |
97 | kref_put(kref: &urb->kref, release: urb_destroy); |
98 | } |
99 | EXPORT_SYMBOL_GPL(usb_free_urb); |
100 | |
101 | /** |
102 | * usb_get_urb - increments the reference count of the urb |
103 | * @urb: pointer to the urb to modify, may be NULL |
104 | * |
105 | * This must be called whenever a urb is transferred from a device driver to a |
106 | * host controller driver. This allows proper reference counting to happen |
107 | * for urbs. |
108 | * |
109 | * Return: A pointer to the urb with the incremented reference counter. |
110 | */ |
111 | struct urb *usb_get_urb(struct urb *urb) |
112 | { |
113 | if (urb) |
114 | kref_get(kref: &urb->kref); |
115 | return urb; |
116 | } |
117 | EXPORT_SYMBOL_GPL(usb_get_urb); |
118 | |
119 | /** |
120 | * usb_anchor_urb - anchors an URB while it is processed |
121 | * @urb: pointer to the urb to anchor |
122 | * @anchor: pointer to the anchor |
123 | * |
124 | * This can be called to have access to URBs which are to be executed |
125 | * without bothering to track them |
126 | */ |
127 | void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor) |
128 | { |
129 | unsigned long flags; |
130 | |
131 | spin_lock_irqsave(&anchor->lock, flags); |
132 | usb_get_urb(urb); |
133 | list_add_tail(new: &urb->anchor_list, head: &anchor->urb_list); |
134 | urb->anchor = anchor; |
135 | |
136 | if (unlikely(anchor->poisoned)) |
137 | atomic_inc(v: &urb->reject); |
138 | |
139 | spin_unlock_irqrestore(lock: &anchor->lock, flags); |
140 | } |
141 | EXPORT_SYMBOL_GPL(usb_anchor_urb); |
142 | |
143 | static int usb_anchor_check_wakeup(struct usb_anchor *anchor) |
144 | { |
145 | return atomic_read(v: &anchor->suspend_wakeups) == 0 && |
146 | list_empty(head: &anchor->urb_list); |
147 | } |
148 | |
149 | /* Callers must hold anchor->lock */ |
150 | static void __usb_unanchor_urb(struct urb *urb, struct usb_anchor *anchor) |
151 | { |
152 | urb->anchor = NULL; |
153 | list_del(entry: &urb->anchor_list); |
154 | usb_put_urb(urb); |
155 | if (usb_anchor_check_wakeup(anchor)) |
156 | wake_up(&anchor->wait); |
157 | } |
158 | |
159 | /** |
160 | * usb_unanchor_urb - unanchors an URB |
161 | * @urb: pointer to the urb to anchor |
162 | * |
163 | * Call this to stop the system keeping track of this URB |
164 | */ |
165 | void usb_unanchor_urb(struct urb *urb) |
166 | { |
167 | unsigned long flags; |
168 | struct usb_anchor *anchor; |
169 | |
170 | if (!urb) |
171 | return; |
172 | |
173 | anchor = urb->anchor; |
174 | if (!anchor) |
175 | return; |
176 | |
177 | spin_lock_irqsave(&anchor->lock, flags); |
178 | /* |
179 | * At this point, we could be competing with another thread which |
180 | * has the same intention. To protect the urb from being unanchored |
181 | * twice, only the winner of the race gets the job. |
182 | */ |
183 | if (likely(anchor == urb->anchor)) |
184 | __usb_unanchor_urb(urb, anchor); |
185 | spin_unlock_irqrestore(lock: &anchor->lock, flags); |
186 | } |
187 | EXPORT_SYMBOL_GPL(usb_unanchor_urb); |
188 | |
189 | /*-------------------------------------------------------------------*/ |
190 | |
191 | static const int pipetypes[4] = { |
192 | PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT |
193 | }; |
194 | |
195 | /** |
196 | * usb_pipe_type_check - sanity check of a specific pipe for a usb device |
197 | * @dev: struct usb_device to be checked |
198 | * @pipe: pipe to check |
199 | * |
200 | * This performs a light-weight sanity check for the endpoint in the |
201 | * given usb device. It returns 0 if the pipe is valid for the specific usb |
202 | * device, otherwise a negative error code. |
203 | */ |
204 | int usb_pipe_type_check(struct usb_device *dev, unsigned int pipe) |
205 | { |
206 | const struct usb_host_endpoint *ep; |
207 | |
208 | ep = usb_pipe_endpoint(dev, pipe); |
209 | if (!ep) |
210 | return -EINVAL; |
211 | if (usb_pipetype(pipe) != pipetypes[usb_endpoint_type(epd: &ep->desc)]) |
212 | return -EINVAL; |
213 | return 0; |
214 | } |
215 | EXPORT_SYMBOL_GPL(usb_pipe_type_check); |
216 | |
217 | /** |
218 | * usb_urb_ep_type_check - sanity check of endpoint in the given urb |
219 | * @urb: urb to be checked |
220 | * |
221 | * This performs a light-weight sanity check for the endpoint in the |
222 | * given urb. It returns 0 if the urb contains a valid endpoint, otherwise |
223 | * a negative error code. |
224 | */ |
225 | int usb_urb_ep_type_check(const struct urb *urb) |
226 | { |
227 | return usb_pipe_type_check(urb->dev, urb->pipe); |
228 | } |
229 | EXPORT_SYMBOL_GPL(usb_urb_ep_type_check); |
230 | |
231 | /** |
232 | * usb_submit_urb - issue an asynchronous transfer request for an endpoint |
233 | * @urb: pointer to the urb describing the request |
234 | * @mem_flags: the type of memory to allocate, see kmalloc() for a list |
235 | * of valid options for this. |
236 | * |
237 | * This submits a transfer request, and transfers control of the URB |
238 | * describing that request to the USB subsystem. Request completion will |
239 | * be indicated later, asynchronously, by calling the completion handler. |
240 | * The three types of completion are success, error, and unlink |
241 | * (a software-induced fault, also called "request cancellation"). |
242 | * |
243 | * URBs may be submitted in interrupt context. |
244 | * |
245 | * The caller must have correctly initialized the URB before submitting |
246 | * it. Functions such as usb_fill_bulk_urb() and usb_fill_control_urb() are |
247 | * available to ensure that most fields are correctly initialized, for |
248 | * the particular kind of transfer, although they will not initialize |
249 | * any transfer flags. |
250 | * |
251 | * If the submission is successful, the complete() callback from the URB |
252 | * will be called exactly once, when the USB core and Host Controller Driver |
253 | * (HCD) are finished with the URB. When the completion function is called, |
254 | * control of the URB is returned to the device driver which issued the |
255 | * request. The completion handler may then immediately free or reuse that |
256 | * URB. |
257 | * |
258 | * With few exceptions, USB device drivers should never access URB fields |
259 | * provided by usbcore or the HCD until its complete() is called. |
260 | * The exceptions relate to periodic transfer scheduling. For both |
261 | * interrupt and isochronous urbs, as part of successful URB submission |
262 | * urb->interval is modified to reflect the actual transfer period used |
263 | * (normally some power of two units). And for isochronous urbs, |
264 | * urb->start_frame is modified to reflect when the URB's transfers were |
265 | * scheduled to start. |
266 | * |
267 | * Not all isochronous transfer scheduling policies will work, but most |
268 | * host controller drivers should easily handle ISO queues going from now |
269 | * until 10-200 msec into the future. Drivers should try to keep at |
270 | * least one or two msec of data in the queue; many controllers require |
271 | * that new transfers start at least 1 msec in the future when they are |
272 | * added. If the driver is unable to keep up and the queue empties out, |
273 | * the behavior for new submissions is governed by the URB_ISO_ASAP flag. |
274 | * If the flag is set, or if the queue is idle, then the URB is always |
275 | * assigned to the first available (and not yet expired) slot in the |
276 | * endpoint's schedule. If the flag is not set and the queue is active |
277 | * then the URB is always assigned to the next slot in the schedule |
278 | * following the end of the endpoint's previous URB, even if that slot is |
279 | * in the past. When a packet is assigned in this way to a slot that has |
280 | * already expired, the packet is not transmitted and the corresponding |
281 | * usb_iso_packet_descriptor's status field will return -EXDEV. If this |
282 | * would happen to all the packets in the URB, submission fails with a |
283 | * -EXDEV error code. |
284 | * |
285 | * For control endpoints, the synchronous usb_control_msg() call is |
286 | * often used (in non-interrupt context) instead of this call. |
287 | * That is often used through convenience wrappers, for the requests |
288 | * that are standardized in the USB 2.0 specification. For bulk |
289 | * endpoints, a synchronous usb_bulk_msg() call is available. |
290 | * |
291 | * Return: |
292 | * 0 on successful submissions. A negative error number otherwise. |
293 | * |
294 | * Request Queuing: |
295 | * |
296 | * URBs may be submitted to endpoints before previous ones complete, to |
297 | * minimize the impact of interrupt latencies and system overhead on data |
298 | * throughput. With that queuing policy, an endpoint's queue would never |
299 | * be empty. This is required for continuous isochronous data streams, |
300 | * and may also be required for some kinds of interrupt transfers. Such |
301 | * queuing also maximizes bandwidth utilization by letting USB controllers |
302 | * start work on later requests before driver software has finished the |
303 | * completion processing for earlier (successful) requests. |
304 | * |
305 | * As of Linux 2.6, all USB endpoint transfer queues support depths greater |
306 | * than one. This was previously a HCD-specific behavior, except for ISO |
307 | * transfers. Non-isochronous endpoint queues are inactive during cleanup |
308 | * after faults (transfer errors or cancellation). |
309 | * |
310 | * Reserved Bandwidth Transfers: |
311 | * |
312 | * Periodic transfers (interrupt or isochronous) are performed repeatedly, |
313 | * using the interval specified in the urb. Submitting the first urb to |
314 | * the endpoint reserves the bandwidth necessary to make those transfers. |
315 | * If the USB subsystem can't allocate sufficient bandwidth to perform |
316 | * the periodic request, submitting such a periodic request should fail. |
317 | * |
318 | * For devices under xHCI, the bandwidth is reserved at configuration time, or |
319 | * when the alt setting is selected. If there is not enough bus bandwidth, the |
320 | * configuration/alt setting request will fail. Therefore, submissions to |
321 | * periodic endpoints on devices under xHCI should never fail due to bandwidth |
322 | * constraints. |
323 | * |
324 | * Device drivers must explicitly request that repetition, by ensuring that |
325 | * some URB is always on the endpoint's queue (except possibly for short |
326 | * periods during completion callbacks). When there is no longer an urb |
327 | * queued, the endpoint's bandwidth reservation is canceled. This means |
328 | * drivers can use their completion handlers to ensure they keep bandwidth |
329 | * they need, by reinitializing and resubmitting the just-completed urb |
330 | * until the driver longer needs that periodic bandwidth. |
331 | * |
332 | * Memory Flags: |
333 | * |
334 | * The general rules for how to decide which mem_flags to use |
335 | * are the same as for kmalloc. There are four |
336 | * different possible values; GFP_KERNEL, GFP_NOFS, GFP_NOIO and |
337 | * GFP_ATOMIC. |
338 | * |
339 | * GFP_NOFS is not ever used, as it has not been implemented yet. |
340 | * |
341 | * GFP_ATOMIC is used when |
342 | * (a) you are inside a completion handler, an interrupt, bottom half, |
343 | * tasklet or timer, or |
344 | * (b) you are holding a spinlock or rwlock (does not apply to |
345 | * semaphores), or |
346 | * (c) current->state != TASK_RUNNING, this is the case only after |
347 | * you've changed it. |
348 | * |
349 | * GFP_NOIO is used in the block io path and error handling of storage |
350 | * devices. |
351 | * |
352 | * All other situations use GFP_KERNEL. |
353 | * |
354 | * Some more specific rules for mem_flags can be inferred, such as |
355 | * (1) start_xmit, timeout, and receive methods of network drivers must |
356 | * use GFP_ATOMIC (they are called with a spinlock held); |
357 | * (2) queuecommand methods of scsi drivers must use GFP_ATOMIC (also |
358 | * called with a spinlock held); |
359 | * (3) If you use a kernel thread with a network driver you must use |
360 | * GFP_NOIO, unless (b) or (c) apply; |
361 | * (4) after you have done a down() you can use GFP_KERNEL, unless (b) or (c) |
362 | * apply or your are in a storage driver's block io path; |
363 | * (5) USB probe and disconnect can use GFP_KERNEL unless (b) or (c) apply; and |
364 | * (6) changing firmware on a running storage or net device uses |
365 | * GFP_NOIO, unless b) or c) apply |
366 | * |
367 | */ |
368 | int usb_submit_urb(struct urb *urb, gfp_t mem_flags) |
369 | { |
370 | int xfertype, max; |
371 | struct usb_device *dev; |
372 | struct usb_host_endpoint *ep; |
373 | int is_out; |
374 | unsigned int allowed; |
375 | |
376 | if (!urb || !urb->complete) |
377 | return -EINVAL; |
378 | if (urb->hcpriv) { |
379 | WARN_ONCE(1, "URB %pK submitted while active\n" , urb); |
380 | return -EBUSY; |
381 | } |
382 | |
383 | dev = urb->dev; |
384 | if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED)) |
385 | return -ENODEV; |
386 | |
387 | /* For now, get the endpoint from the pipe. Eventually drivers |
388 | * will be required to set urb->ep directly and we will eliminate |
389 | * urb->pipe. |
390 | */ |
391 | ep = usb_pipe_endpoint(dev, pipe: urb->pipe); |
392 | if (!ep) |
393 | return -ENOENT; |
394 | |
395 | urb->ep = ep; |
396 | urb->status = -EINPROGRESS; |
397 | urb->actual_length = 0; |
398 | |
399 | /* Lots of sanity checks, so HCDs can rely on clean data |
400 | * and don't need to duplicate tests |
401 | */ |
402 | xfertype = usb_endpoint_type(epd: &ep->desc); |
403 | if (xfertype == USB_ENDPOINT_XFER_CONTROL) { |
404 | struct usb_ctrlrequest *setup = |
405 | (struct usb_ctrlrequest *) urb->setup_packet; |
406 | |
407 | if (!setup) |
408 | return -ENOEXEC; |
409 | is_out = !(setup->bRequestType & USB_DIR_IN) || |
410 | !setup->wLength; |
411 | dev_WARN_ONCE(&dev->dev, (usb_pipeout(urb->pipe) != is_out), |
412 | "BOGUS control dir, pipe %x doesn't match bRequestType %x\n" , |
413 | urb->pipe, setup->bRequestType); |
414 | if (le16_to_cpu(setup->wLength) != urb->transfer_buffer_length) { |
415 | dev_dbg(&dev->dev, "BOGUS control len %d doesn't match transfer length %d\n" , |
416 | le16_to_cpu(setup->wLength), |
417 | urb->transfer_buffer_length); |
418 | return -EBADR; |
419 | } |
420 | } else { |
421 | is_out = usb_endpoint_dir_out(epd: &ep->desc); |
422 | } |
423 | |
424 | /* Clear the internal flags and cache the direction for later use */ |
425 | urb->transfer_flags &= ~(URB_DIR_MASK | URB_DMA_MAP_SINGLE | |
426 | URB_DMA_MAP_PAGE | URB_DMA_MAP_SG | URB_MAP_LOCAL | |
427 | URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL | |
428 | URB_DMA_SG_COMBINED); |
429 | urb->transfer_flags |= (is_out ? URB_DIR_OUT : URB_DIR_IN); |
430 | kmsan_handle_urb(urb, is_out); |
431 | |
432 | if (xfertype != USB_ENDPOINT_XFER_CONTROL && |
433 | dev->state < USB_STATE_CONFIGURED) |
434 | return -ENODEV; |
435 | |
436 | max = usb_endpoint_maxp(epd: &ep->desc); |
437 | if (max <= 0) { |
438 | dev_dbg(&dev->dev, |
439 | "bogus endpoint ep%d%s in %s (bad maxpacket %d)\n" , |
440 | usb_endpoint_num(&ep->desc), is_out ? "out" : "in" , |
441 | __func__, max); |
442 | return -EMSGSIZE; |
443 | } |
444 | |
445 | /* periodic transfers limit size per frame/uframe, |
446 | * but drivers only control those sizes for ISO. |
447 | * while we're checking, initialize return status. |
448 | */ |
449 | if (xfertype == USB_ENDPOINT_XFER_ISOC) { |
450 | int n, len; |
451 | |
452 | /* SuperSpeed isoc endpoints have up to 16 bursts of up to |
453 | * 3 packets each |
454 | */ |
455 | if (dev->speed >= USB_SPEED_SUPER) { |
456 | int burst = 1 + ep->ss_ep_comp.bMaxBurst; |
457 | int mult = USB_SS_MULT(ep->ss_ep_comp.bmAttributes); |
458 | max *= burst; |
459 | max *= mult; |
460 | } |
461 | |
462 | if (dev->speed == USB_SPEED_SUPER_PLUS && |
463 | USB_SS_SSP_ISOC_COMP(ep->ss_ep_comp.bmAttributes)) { |
464 | struct usb_ssp_isoc_ep_comp_descriptor *isoc_ep_comp; |
465 | |
466 | isoc_ep_comp = &ep->ssp_isoc_ep_comp; |
467 | max = le32_to_cpu(isoc_ep_comp->dwBytesPerInterval); |
468 | } |
469 | |
470 | /* "high bandwidth" mode, 1-3 packets/uframe? */ |
471 | if (dev->speed == USB_SPEED_HIGH) |
472 | max *= usb_endpoint_maxp_mult(epd: &ep->desc); |
473 | |
474 | if (urb->number_of_packets <= 0) |
475 | return -EINVAL; |
476 | for (n = 0; n < urb->number_of_packets; n++) { |
477 | len = urb->iso_frame_desc[n].length; |
478 | if (len < 0 || len > max) |
479 | return -EMSGSIZE; |
480 | urb->iso_frame_desc[n].status = -EXDEV; |
481 | urb->iso_frame_desc[n].actual_length = 0; |
482 | } |
483 | } else if (urb->num_sgs && !urb->dev->bus->no_sg_constraint) { |
484 | struct scatterlist *sg; |
485 | int i; |
486 | |
487 | for_each_sg(urb->sg, sg, urb->num_sgs - 1, i) |
488 | if (sg->length % max) |
489 | return -EINVAL; |
490 | } |
491 | |
492 | /* the I/O buffer must be mapped/unmapped, except when length=0 */ |
493 | if (urb->transfer_buffer_length > INT_MAX) |
494 | return -EMSGSIZE; |
495 | |
496 | /* |
497 | * stuff that drivers shouldn't do, but which shouldn't |
498 | * cause problems in HCDs if they get it wrong. |
499 | */ |
500 | |
501 | /* Check that the pipe's type matches the endpoint's type */ |
502 | if (usb_pipe_type_check(urb->dev, urb->pipe)) |
503 | dev_WARN(&dev->dev, "BOGUS urb xfer, pipe %x != type %x\n" , |
504 | usb_pipetype(urb->pipe), pipetypes[xfertype]); |
505 | |
506 | /* Check against a simple/standard policy */ |
507 | allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT | URB_DIR_MASK | |
508 | URB_FREE_BUFFER); |
509 | switch (xfertype) { |
510 | case USB_ENDPOINT_XFER_BULK: |
511 | case USB_ENDPOINT_XFER_INT: |
512 | if (is_out) |
513 | allowed |= URB_ZERO_PACKET; |
514 | fallthrough; |
515 | default: /* all non-iso endpoints */ |
516 | if (!is_out) |
517 | allowed |= URB_SHORT_NOT_OK; |
518 | break; |
519 | case USB_ENDPOINT_XFER_ISOC: |
520 | allowed |= URB_ISO_ASAP; |
521 | break; |
522 | } |
523 | allowed &= urb->transfer_flags; |
524 | |
525 | /* warn if submitter gave bogus flags */ |
526 | if (allowed != urb->transfer_flags) |
527 | dev_WARN(&dev->dev, "BOGUS urb flags, %x --> %x\n" , |
528 | urb->transfer_flags, allowed); |
529 | |
530 | /* |
531 | * Force periodic transfer intervals to be legal values that are |
532 | * a power of two (so HCDs don't need to). |
533 | * |
534 | * FIXME want bus->{intr,iso}_sched_horizon values here. Each HC |
535 | * supports different values... this uses EHCI/UHCI defaults (and |
536 | * EHCI can use smaller non-default values). |
537 | */ |
538 | switch (xfertype) { |
539 | case USB_ENDPOINT_XFER_ISOC: |
540 | case USB_ENDPOINT_XFER_INT: |
541 | /* too small? */ |
542 | if (urb->interval <= 0) |
543 | return -EINVAL; |
544 | |
545 | /* too big? */ |
546 | switch (dev->speed) { |
547 | case USB_SPEED_SUPER_PLUS: |
548 | case USB_SPEED_SUPER: /* units are 125us */ |
549 | /* Handle up to 2^(16-1) microframes */ |
550 | if (urb->interval > (1 << 15)) |
551 | return -EINVAL; |
552 | max = 1 << 15; |
553 | break; |
554 | case USB_SPEED_HIGH: /* units are microframes */ |
555 | /* NOTE usb handles 2^15 */ |
556 | if (urb->interval > (1024 * 8)) |
557 | urb->interval = 1024 * 8; |
558 | max = 1024 * 8; |
559 | break; |
560 | case USB_SPEED_FULL: /* units are frames/msec */ |
561 | case USB_SPEED_LOW: |
562 | if (xfertype == USB_ENDPOINT_XFER_INT) { |
563 | if (urb->interval > 255) |
564 | return -EINVAL; |
565 | /* NOTE ohci only handles up to 32 */ |
566 | max = 128; |
567 | } else { |
568 | if (urb->interval > 1024) |
569 | urb->interval = 1024; |
570 | /* NOTE usb and ohci handle up to 2^15 */ |
571 | max = 1024; |
572 | } |
573 | break; |
574 | default: |
575 | return -EINVAL; |
576 | } |
577 | /* Round down to a power of 2, no more than max */ |
578 | urb->interval = min(max, 1 << ilog2(urb->interval)); |
579 | } |
580 | |
581 | return usb_hcd_submit_urb(urb, mem_flags); |
582 | } |
583 | EXPORT_SYMBOL_GPL(usb_submit_urb); |
584 | |
585 | /*-------------------------------------------------------------------*/ |
586 | |
587 | /** |
588 | * usb_unlink_urb - abort/cancel a transfer request for an endpoint |
589 | * @urb: pointer to urb describing a previously submitted request, |
590 | * may be NULL |
591 | * |
592 | * This routine cancels an in-progress request. URBs complete only once |
593 | * per submission, and may be canceled only once per submission. |
594 | * Successful cancellation means termination of @urb will be expedited |
595 | * and the completion handler will be called with a status code |
596 | * indicating that the request has been canceled (rather than any other |
597 | * code). |
598 | * |
599 | * Drivers should not call this routine or related routines, such as |
600 | * usb_kill_urb() or usb_unlink_anchored_urbs(), after their disconnect |
601 | * method has returned. The disconnect function should synchronize with |
602 | * a driver's I/O routines to insure that all URB-related activity has |
603 | * completed before it returns. |
604 | * |
605 | * This request is asynchronous, however the HCD might call the ->complete() |
606 | * callback during unlink. Therefore when drivers call usb_unlink_urb(), they |
607 | * must not hold any locks that may be taken by the completion function. |
608 | * Success is indicated by returning -EINPROGRESS, at which time the URB will |
609 | * probably not yet have been given back to the device driver. When it is |
610 | * eventually called, the completion function will see @urb->status == |
611 | * -ECONNRESET. |
612 | * Failure is indicated by usb_unlink_urb() returning any other value. |
613 | * Unlinking will fail when @urb is not currently "linked" (i.e., it was |
614 | * never submitted, or it was unlinked before, or the hardware is already |
615 | * finished with it), even if the completion handler has not yet run. |
616 | * |
617 | * The URB must not be deallocated while this routine is running. In |
618 | * particular, when a driver calls this routine, it must insure that the |
619 | * completion handler cannot deallocate the URB. |
620 | * |
621 | * Return: -EINPROGRESS on success. See description for other values on |
622 | * failure. |
623 | * |
624 | * Unlinking and Endpoint Queues: |
625 | * |
626 | * [The behaviors and guarantees described below do not apply to virtual |
627 | * root hubs but only to endpoint queues for physical USB devices.] |
628 | * |
629 | * Host Controller Drivers (HCDs) place all the URBs for a particular |
630 | * endpoint in a queue. Normally the queue advances as the controller |
631 | * hardware processes each request. But when an URB terminates with an |
632 | * error its queue generally stops (see below), at least until that URB's |
633 | * completion routine returns. It is guaranteed that a stopped queue |
634 | * will not restart until all its unlinked URBs have been fully retired, |
635 | * with their completion routines run, even if that's not until some time |
636 | * after the original completion handler returns. The same behavior and |
637 | * guarantee apply when an URB terminates because it was unlinked. |
638 | * |
639 | * Bulk and interrupt endpoint queues are guaranteed to stop whenever an |
640 | * URB terminates with any sort of error, including -ECONNRESET, -ENOENT, |
641 | * and -EREMOTEIO. Control endpoint queues behave the same way except |
642 | * that they are not guaranteed to stop for -EREMOTEIO errors. Queues |
643 | * for isochronous endpoints are treated differently, because they must |
644 | * advance at fixed rates. Such queues do not stop when an URB |
645 | * encounters an error or is unlinked. An unlinked isochronous URB may |
646 | * leave a gap in the stream of packets; it is undefined whether such |
647 | * gaps can be filled in. |
648 | * |
649 | * Note that early termination of an URB because a short packet was |
650 | * received will generate a -EREMOTEIO error if and only if the |
651 | * URB_SHORT_NOT_OK flag is set. By setting this flag, USB device |
652 | * drivers can build deep queues for large or complex bulk transfers |
653 | * and clean them up reliably after any sort of aborted transfer by |
654 | * unlinking all pending URBs at the first fault. |
655 | * |
656 | * When a control URB terminates with an error other than -EREMOTEIO, it |
657 | * is quite likely that the status stage of the transfer will not take |
658 | * place. |
659 | */ |
660 | int usb_unlink_urb(struct urb *urb) |
661 | { |
662 | if (!urb) |
663 | return -EINVAL; |
664 | if (!urb->dev) |
665 | return -ENODEV; |
666 | if (!urb->ep) |
667 | return -EIDRM; |
668 | return usb_hcd_unlink_urb(urb, status: -ECONNRESET); |
669 | } |
670 | EXPORT_SYMBOL_GPL(usb_unlink_urb); |
671 | |
672 | /** |
673 | * usb_kill_urb - cancel a transfer request and wait for it to finish |
674 | * @urb: pointer to URB describing a previously submitted request, |
675 | * may be NULL |
676 | * |
677 | * This routine cancels an in-progress request. It is guaranteed that |
678 | * upon return all completion handlers will have finished and the URB |
679 | * will be totally idle and available for reuse. These features make |
680 | * this an ideal way to stop I/O in a disconnect() callback or close() |
681 | * function. If the request has not already finished or been unlinked |
682 | * the completion handler will see urb->status == -ENOENT. |
683 | * |
684 | * While the routine is running, attempts to resubmit the URB will fail |
685 | * with error -EPERM. Thus even if the URB's completion handler always |
686 | * tries to resubmit, it will not succeed and the URB will become idle. |
687 | * |
688 | * The URB must not be deallocated while this routine is running. In |
689 | * particular, when a driver calls this routine, it must insure that the |
690 | * completion handler cannot deallocate the URB. |
691 | * |
692 | * This routine may not be used in an interrupt context (such as a bottom |
693 | * half or a completion handler), or when holding a spinlock, or in other |
694 | * situations where the caller can't schedule(). |
695 | * |
696 | * This routine should not be called by a driver after its disconnect |
697 | * method has returned. |
698 | */ |
699 | void usb_kill_urb(struct urb *urb) |
700 | { |
701 | might_sleep(); |
702 | if (!(urb && urb->dev && urb->ep)) |
703 | return; |
704 | atomic_inc(v: &urb->reject); |
705 | /* |
706 | * Order the write of urb->reject above before the read |
707 | * of urb->use_count below. Pairs with the barriers in |
708 | * __usb_hcd_giveback_urb() and usb_hcd_submit_urb(). |
709 | */ |
710 | smp_mb__after_atomic(); |
711 | |
712 | usb_hcd_unlink_urb(urb, status: -ENOENT); |
713 | wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); |
714 | |
715 | atomic_dec(v: &urb->reject); |
716 | } |
717 | EXPORT_SYMBOL_GPL(usb_kill_urb); |
718 | |
719 | /** |
720 | * usb_poison_urb - reliably kill a transfer and prevent further use of an URB |
721 | * @urb: pointer to URB describing a previously submitted request, |
722 | * may be NULL |
723 | * |
724 | * This routine cancels an in-progress request. It is guaranteed that |
725 | * upon return all completion handlers will have finished and the URB |
726 | * will be totally idle and cannot be reused. These features make |
727 | * this an ideal way to stop I/O in a disconnect() callback. |
728 | * If the request has not already finished or been unlinked |
729 | * the completion handler will see urb->status == -ENOENT. |
730 | * |
731 | * After and while the routine runs, attempts to resubmit the URB will fail |
732 | * with error -EPERM. Thus even if the URB's completion handler always |
733 | * tries to resubmit, it will not succeed and the URB will become idle. |
734 | * |
735 | * The URB must not be deallocated while this routine is running. In |
736 | * particular, when a driver calls this routine, it must insure that the |
737 | * completion handler cannot deallocate the URB. |
738 | * |
739 | * This routine may not be used in an interrupt context (such as a bottom |
740 | * half or a completion handler), or when holding a spinlock, or in other |
741 | * situations where the caller can't schedule(). |
742 | * |
743 | * This routine should not be called by a driver after its disconnect |
744 | * method has returned. |
745 | */ |
746 | void usb_poison_urb(struct urb *urb) |
747 | { |
748 | might_sleep(); |
749 | if (!urb) |
750 | return; |
751 | atomic_inc(v: &urb->reject); |
752 | /* |
753 | * Order the write of urb->reject above before the read |
754 | * of urb->use_count below. Pairs with the barriers in |
755 | * __usb_hcd_giveback_urb() and usb_hcd_submit_urb(). |
756 | */ |
757 | smp_mb__after_atomic(); |
758 | |
759 | if (!urb->dev || !urb->ep) |
760 | return; |
761 | |
762 | usb_hcd_unlink_urb(urb, status: -ENOENT); |
763 | wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); |
764 | } |
765 | EXPORT_SYMBOL_GPL(usb_poison_urb); |
766 | |
767 | void usb_unpoison_urb(struct urb *urb) |
768 | { |
769 | if (!urb) |
770 | return; |
771 | |
772 | atomic_dec(v: &urb->reject); |
773 | } |
774 | EXPORT_SYMBOL_GPL(usb_unpoison_urb); |
775 | |
776 | /** |
777 | * usb_block_urb - reliably prevent further use of an URB |
778 | * @urb: pointer to URB to be blocked, may be NULL |
779 | * |
780 | * After the routine has run, attempts to resubmit the URB will fail |
781 | * with error -EPERM. Thus even if the URB's completion handler always |
782 | * tries to resubmit, it will not succeed and the URB will become idle. |
783 | * |
784 | * The URB must not be deallocated while this routine is running. In |
785 | * particular, when a driver calls this routine, it must insure that the |
786 | * completion handler cannot deallocate the URB. |
787 | */ |
788 | void usb_block_urb(struct urb *urb) |
789 | { |
790 | if (!urb) |
791 | return; |
792 | |
793 | atomic_inc(v: &urb->reject); |
794 | } |
795 | EXPORT_SYMBOL_GPL(usb_block_urb); |
796 | |
797 | /** |
798 | * usb_kill_anchored_urbs - kill all URBs associated with an anchor |
799 | * @anchor: anchor the requests are bound to |
800 | * |
801 | * This kills all outstanding URBs starting from the back of the queue, |
802 | * with guarantee that no completer callbacks will take place from the |
803 | * anchor after this function returns. |
804 | * |
805 | * This routine should not be called by a driver after its disconnect |
806 | * method has returned. |
807 | */ |
808 | void usb_kill_anchored_urbs(struct usb_anchor *anchor) |
809 | { |
810 | struct urb *victim; |
811 | int surely_empty; |
812 | |
813 | do { |
814 | spin_lock_irq(lock: &anchor->lock); |
815 | while (!list_empty(head: &anchor->urb_list)) { |
816 | victim = list_entry(anchor->urb_list.prev, |
817 | struct urb, anchor_list); |
818 | /* make sure the URB isn't freed before we kill it */ |
819 | usb_get_urb(victim); |
820 | spin_unlock_irq(lock: &anchor->lock); |
821 | /* this will unanchor the URB */ |
822 | usb_kill_urb(victim); |
823 | usb_put_urb(victim); |
824 | spin_lock_irq(lock: &anchor->lock); |
825 | } |
826 | surely_empty = usb_anchor_check_wakeup(anchor); |
827 | |
828 | spin_unlock_irq(lock: &anchor->lock); |
829 | cpu_relax(); |
830 | } while (!surely_empty); |
831 | } |
832 | EXPORT_SYMBOL_GPL(usb_kill_anchored_urbs); |
833 | |
834 | |
835 | /** |
836 | * usb_poison_anchored_urbs - cease all traffic from an anchor |
837 | * @anchor: anchor the requests are bound to |
838 | * |
839 | * this allows all outstanding URBs to be poisoned starting |
840 | * from the back of the queue. Newly added URBs will also be |
841 | * poisoned |
842 | * |
843 | * This routine should not be called by a driver after its disconnect |
844 | * method has returned. |
845 | */ |
846 | void usb_poison_anchored_urbs(struct usb_anchor *anchor) |
847 | { |
848 | struct urb *victim; |
849 | int surely_empty; |
850 | |
851 | do { |
852 | spin_lock_irq(lock: &anchor->lock); |
853 | anchor->poisoned = 1; |
854 | while (!list_empty(head: &anchor->urb_list)) { |
855 | victim = list_entry(anchor->urb_list.prev, |
856 | struct urb, anchor_list); |
857 | /* make sure the URB isn't freed before we kill it */ |
858 | usb_get_urb(victim); |
859 | spin_unlock_irq(lock: &anchor->lock); |
860 | /* this will unanchor the URB */ |
861 | usb_poison_urb(victim); |
862 | usb_put_urb(victim); |
863 | spin_lock_irq(lock: &anchor->lock); |
864 | } |
865 | surely_empty = usb_anchor_check_wakeup(anchor); |
866 | |
867 | spin_unlock_irq(lock: &anchor->lock); |
868 | cpu_relax(); |
869 | } while (!surely_empty); |
870 | } |
871 | EXPORT_SYMBOL_GPL(usb_poison_anchored_urbs); |
872 | |
873 | /** |
874 | * usb_unpoison_anchored_urbs - let an anchor be used successfully again |
875 | * @anchor: anchor the requests are bound to |
876 | * |
877 | * Reverses the effect of usb_poison_anchored_urbs |
878 | * the anchor can be used normally after it returns |
879 | */ |
880 | void usb_unpoison_anchored_urbs(struct usb_anchor *anchor) |
881 | { |
882 | unsigned long flags; |
883 | struct urb *lazarus; |
884 | |
885 | spin_lock_irqsave(&anchor->lock, flags); |
886 | list_for_each_entry(lazarus, &anchor->urb_list, anchor_list) { |
887 | usb_unpoison_urb(lazarus); |
888 | } |
889 | anchor->poisoned = 0; |
890 | spin_unlock_irqrestore(lock: &anchor->lock, flags); |
891 | } |
892 | EXPORT_SYMBOL_GPL(usb_unpoison_anchored_urbs); |
893 | /** |
894 | * usb_unlink_anchored_urbs - asynchronously cancel transfer requests en masse |
895 | * @anchor: anchor the requests are bound to |
896 | * |
897 | * this allows all outstanding URBs to be unlinked starting |
898 | * from the back of the queue. This function is asynchronous. |
899 | * The unlinking is just triggered. It may happen after this |
900 | * function has returned. |
901 | * |
902 | * This routine should not be called by a driver after its disconnect |
903 | * method has returned. |
904 | */ |
905 | void usb_unlink_anchored_urbs(struct usb_anchor *anchor) |
906 | { |
907 | struct urb *victim; |
908 | |
909 | while ((victim = usb_get_from_anchor(anchor)) != NULL) { |
910 | usb_unlink_urb(victim); |
911 | usb_put_urb(victim); |
912 | } |
913 | } |
914 | EXPORT_SYMBOL_GPL(usb_unlink_anchored_urbs); |
915 | |
916 | /** |
917 | * usb_anchor_suspend_wakeups |
918 | * @anchor: the anchor you want to suspend wakeups on |
919 | * |
920 | * Call this to stop the last urb being unanchored from waking up any |
921 | * usb_wait_anchor_empty_timeout waiters. This is used in the hcd urb give- |
922 | * back path to delay waking up until after the completion handler has run. |
923 | */ |
924 | void usb_anchor_suspend_wakeups(struct usb_anchor *anchor) |
925 | { |
926 | if (anchor) |
927 | atomic_inc(v: &anchor->suspend_wakeups); |
928 | } |
929 | EXPORT_SYMBOL_GPL(usb_anchor_suspend_wakeups); |
930 | |
931 | /** |
932 | * usb_anchor_resume_wakeups |
933 | * @anchor: the anchor you want to resume wakeups on |
934 | * |
935 | * Allow usb_wait_anchor_empty_timeout waiters to be woken up again, and |
936 | * wake up any current waiters if the anchor is empty. |
937 | */ |
938 | void usb_anchor_resume_wakeups(struct usb_anchor *anchor) |
939 | { |
940 | if (!anchor) |
941 | return; |
942 | |
943 | atomic_dec(v: &anchor->suspend_wakeups); |
944 | if (usb_anchor_check_wakeup(anchor)) |
945 | wake_up(&anchor->wait); |
946 | } |
947 | EXPORT_SYMBOL_GPL(usb_anchor_resume_wakeups); |
948 | |
949 | /** |
950 | * usb_wait_anchor_empty_timeout - wait for an anchor to be unused |
951 | * @anchor: the anchor you want to become unused |
952 | * @timeout: how long you are willing to wait in milliseconds |
953 | * |
954 | * Call this is you want to be sure all an anchor's |
955 | * URBs have finished |
956 | * |
957 | * Return: Non-zero if the anchor became unused. Zero on timeout. |
958 | */ |
959 | int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor, |
960 | unsigned int timeout) |
961 | { |
962 | return wait_event_timeout(anchor->wait, |
963 | usb_anchor_check_wakeup(anchor), |
964 | msecs_to_jiffies(timeout)); |
965 | } |
966 | EXPORT_SYMBOL_GPL(usb_wait_anchor_empty_timeout); |
967 | |
968 | /** |
969 | * usb_get_from_anchor - get an anchor's oldest urb |
970 | * @anchor: the anchor whose urb you want |
971 | * |
972 | * This will take the oldest urb from an anchor, |
973 | * unanchor and return it |
974 | * |
975 | * Return: The oldest urb from @anchor, or %NULL if @anchor has no |
976 | * urbs associated with it. |
977 | */ |
978 | struct urb *usb_get_from_anchor(struct usb_anchor *anchor) |
979 | { |
980 | struct urb *victim; |
981 | unsigned long flags; |
982 | |
983 | spin_lock_irqsave(&anchor->lock, flags); |
984 | if (!list_empty(head: &anchor->urb_list)) { |
985 | victim = list_entry(anchor->urb_list.next, struct urb, |
986 | anchor_list); |
987 | usb_get_urb(victim); |
988 | __usb_unanchor_urb(urb: victim, anchor); |
989 | } else { |
990 | victim = NULL; |
991 | } |
992 | spin_unlock_irqrestore(lock: &anchor->lock, flags); |
993 | |
994 | return victim; |
995 | } |
996 | |
997 | EXPORT_SYMBOL_GPL(usb_get_from_anchor); |
998 | |
999 | /** |
1000 | * usb_scuttle_anchored_urbs - unanchor all an anchor's urbs |
1001 | * @anchor: the anchor whose urbs you want to unanchor |
1002 | * |
1003 | * use this to get rid of all an anchor's urbs |
1004 | */ |
1005 | void usb_scuttle_anchored_urbs(struct usb_anchor *anchor) |
1006 | { |
1007 | struct urb *victim; |
1008 | unsigned long flags; |
1009 | int surely_empty; |
1010 | |
1011 | do { |
1012 | spin_lock_irqsave(&anchor->lock, flags); |
1013 | while (!list_empty(head: &anchor->urb_list)) { |
1014 | victim = list_entry(anchor->urb_list.prev, |
1015 | struct urb, anchor_list); |
1016 | __usb_unanchor_urb(urb: victim, anchor); |
1017 | } |
1018 | surely_empty = usb_anchor_check_wakeup(anchor); |
1019 | |
1020 | spin_unlock_irqrestore(lock: &anchor->lock, flags); |
1021 | cpu_relax(); |
1022 | } while (!surely_empty); |
1023 | } |
1024 | |
1025 | EXPORT_SYMBOL_GPL(usb_scuttle_anchored_urbs); |
1026 | |
1027 | /** |
1028 | * usb_anchor_empty - is an anchor empty |
1029 | * @anchor: the anchor you want to query |
1030 | * |
1031 | * Return: 1 if the anchor has no urbs associated with it. |
1032 | */ |
1033 | int usb_anchor_empty(struct usb_anchor *anchor) |
1034 | { |
1035 | return list_empty(head: &anchor->urb_list); |
1036 | } |
1037 | |
1038 | EXPORT_SYMBOL_GPL(usb_anchor_empty); |
1039 | |
1040 | |