1// SPDX-License-Identifier: GPL-2.0
2/*
3 * message.c - synchronous message handling
4 *
5 * Released under the GPLv2 only.
6 */
7
8#include <linux/acpi.h>
9#include <linux/pci.h> /* for scatterlist macros */
10#include <linux/usb.h>
11#include <linux/module.h>
12#include <linux/of.h>
13#include <linux/slab.h>
14#include <linux/mm.h>
15#include <linux/timer.h>
16#include <linux/ctype.h>
17#include <linux/nls.h>
18#include <linux/device.h>
19#include <linux/scatterlist.h>
20#include <linux/usb/cdc.h>
21#include <linux/usb/quirks.h>
22#include <linux/usb/hcd.h> /* for usbcore internals */
23#include <linux/usb/of.h>
24#include <asm/byteorder.h>
25
26#include "usb.h"
27
28static void cancel_async_set_config(struct usb_device *udev);
29
30struct api_context {
31 struct completion done;
32 int status;
33};
34
35static void usb_api_blocking_completion(struct urb *urb)
36{
37 struct api_context *ctx = urb->context;
38
39 ctx->status = urb->status;
40 complete(&ctx->done);
41}
42
43
44/*
45 * Starts urb and waits for completion or timeout. Note that this call
46 * is NOT interruptible. Many device driver i/o requests should be
47 * interruptible and therefore these drivers should implement their
48 * own interruptible routines.
49 */
50static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length)
51{
52 struct api_context ctx;
53 unsigned long expire;
54 int retval;
55
56 init_completion(x: &ctx.done);
57 urb->context = &ctx;
58 urb->actual_length = 0;
59 retval = usb_submit_urb(urb, GFP_NOIO);
60 if (unlikely(retval))
61 goto out;
62
63 expire = timeout ? msecs_to_jiffies(m: timeout) : MAX_SCHEDULE_TIMEOUT;
64 if (!wait_for_completion_timeout(x: &ctx.done, timeout: expire)) {
65 usb_kill_urb(urb);
66 retval = (ctx.status == -ENOENT ? -ETIMEDOUT : ctx.status);
67
68 dev_dbg(&urb->dev->dev,
69 "%s timed out on ep%d%s len=%u/%u\n",
70 current->comm,
71 usb_endpoint_num(&urb->ep->desc),
72 usb_urb_dir_in(urb) ? "in" : "out",
73 urb->actual_length,
74 urb->transfer_buffer_length);
75 } else
76 retval = ctx.status;
77out:
78 if (actual_length)
79 *actual_length = urb->actual_length;
80
81 usb_free_urb(urb);
82 return retval;
83}
84
85/*-------------------------------------------------------------------*/
86/* returns status (negative) or length (positive) */
87static int usb_internal_control_msg(struct usb_device *usb_dev,
88 unsigned int pipe,
89 struct usb_ctrlrequest *cmd,
90 void *data, int len, int timeout)
91{
92 struct urb *urb;
93 int retv;
94 int length;
95
96 urb = usb_alloc_urb(iso_packets: 0, GFP_NOIO);
97 if (!urb)
98 return -ENOMEM;
99
100 usb_fill_control_urb(urb, dev: usb_dev, pipe, setup_packet: (unsigned char *)cmd, transfer_buffer: data,
101 buffer_length: len, complete_fn: usb_api_blocking_completion, NULL);
102
103 retv = usb_start_wait_urb(urb, timeout, actual_length: &length);
104 if (retv < 0)
105 return retv;
106 else
107 return length;
108}
109
110/**
111 * usb_control_msg - Builds a control urb, sends it off and waits for completion
112 * @dev: pointer to the usb device to send the message to
113 * @pipe: endpoint "pipe" to send the message to
114 * @request: USB message request value
115 * @requesttype: USB message request type value
116 * @value: USB message value
117 * @index: USB message index value
118 * @data: pointer to the data to send
119 * @size: length in bytes of the data to send
120 * @timeout: time in msecs to wait for the message to complete before timing
121 * out (if 0 the wait is forever)
122 *
123 * Context: task context, might sleep.
124 *
125 * This function sends a simple control message to a specified endpoint and
126 * waits for the message to complete, or timeout.
127 *
128 * Don't use this function from within an interrupt context. If you need
129 * an asynchronous message, or need to send a message from within interrupt
130 * context, use usb_submit_urb(). If a thread in your driver uses this call,
131 * make sure your disconnect() method can wait for it to complete. Since you
132 * don't have a handle on the URB used, you can't cancel the request.
133 *
134 * Return: If successful, the number of bytes transferred. Otherwise, a negative
135 * error number.
136 */
137int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
138 __u8 requesttype, __u16 value, __u16 index, void *data,
139 __u16 size, int timeout)
140{
141 struct usb_ctrlrequest *dr;
142 int ret;
143
144 dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
145 if (!dr)
146 return -ENOMEM;
147
148 dr->bRequestType = requesttype;
149 dr->bRequest = request;
150 dr->wValue = cpu_to_le16(value);
151 dr->wIndex = cpu_to_le16(index);
152 dr->wLength = cpu_to_le16(size);
153
154 ret = usb_internal_control_msg(usb_dev: dev, pipe, cmd: dr, data, len: size, timeout);
155
156 /* Linger a bit, prior to the next control message. */
157 if (dev->quirks & USB_QUIRK_DELAY_CTRL_MSG)
158 msleep(msecs: 200);
159
160 kfree(objp: dr);
161
162 return ret;
163}
164EXPORT_SYMBOL_GPL(usb_control_msg);
165
166/**
167 * usb_control_msg_send - Builds a control "send" message, sends it off and waits for completion
168 * @dev: pointer to the usb device to send the message to
169 * @endpoint: endpoint to send the message to
170 * @request: USB message request value
171 * @requesttype: USB message request type value
172 * @value: USB message value
173 * @index: USB message index value
174 * @driver_data: pointer to the data to send
175 * @size: length in bytes of the data to send
176 * @timeout: time in msecs to wait for the message to complete before timing
177 * out (if 0 the wait is forever)
178 * @memflags: the flags for memory allocation for buffers
179 *
180 * Context: !in_interrupt ()
181 *
182 * This function sends a control message to a specified endpoint that is not
183 * expected to fill in a response (i.e. a "send message") and waits for the
184 * message to complete, or timeout.
185 *
186 * Do not use this function from within an interrupt context. If you need
187 * an asynchronous message, or need to send a message from within interrupt
188 * context, use usb_submit_urb(). If a thread in your driver uses this call,
189 * make sure your disconnect() method can wait for it to complete. Since you
190 * don't have a handle on the URB used, you can't cancel the request.
191 *
192 * The data pointer can be made to a reference on the stack, or anywhere else,
193 * as it will not be modified at all. This does not have the restriction that
194 * usb_control_msg() has where the data pointer must be to dynamically allocated
195 * memory (i.e. memory that can be successfully DMAed to a device).
196 *
197 * Return: If successful, 0 is returned, Otherwise, a negative error number.
198 */
199int usb_control_msg_send(struct usb_device *dev, __u8 endpoint, __u8 request,
200 __u8 requesttype, __u16 value, __u16 index,
201 const void *driver_data, __u16 size, int timeout,
202 gfp_t memflags)
203{
204 unsigned int pipe = usb_sndctrlpipe(dev, endpoint);
205 int ret;
206 u8 *data = NULL;
207
208 if (size) {
209 data = kmemdup(driver_data, size, memflags);
210 if (!data)
211 return -ENOMEM;
212 }
213
214 ret = usb_control_msg(dev, pipe, request, requesttype, value, index,
215 data, size, timeout);
216 kfree(objp: data);
217
218 if (ret < 0)
219 return ret;
220
221 return 0;
222}
223EXPORT_SYMBOL_GPL(usb_control_msg_send);
224
225/**
226 * usb_control_msg_recv - Builds a control "receive" message, sends it off and waits for completion
227 * @dev: pointer to the usb device to send the message to
228 * @endpoint: endpoint to send the message to
229 * @request: USB message request value
230 * @requesttype: USB message request type value
231 * @value: USB message value
232 * @index: USB message index value
233 * @driver_data: pointer to the data to be filled in by the message
234 * @size: length in bytes of the data to be received
235 * @timeout: time in msecs to wait for the message to complete before timing
236 * out (if 0 the wait is forever)
237 * @memflags: the flags for memory allocation for buffers
238 *
239 * Context: !in_interrupt ()
240 *
241 * This function sends a control message to a specified endpoint that is
242 * expected to fill in a response (i.e. a "receive message") and waits for the
243 * message to complete, or timeout.
244 *
245 * Do not use this function from within an interrupt context. If you need
246 * an asynchronous message, or need to send a message from within interrupt
247 * context, use usb_submit_urb(). If a thread in your driver uses this call,
248 * make sure your disconnect() method can wait for it to complete. Since you
249 * don't have a handle on the URB used, you can't cancel the request.
250 *
251 * The data pointer can be made to a reference on the stack, or anywhere else
252 * that can be successfully written to. This function does not have the
253 * restriction that usb_control_msg() has where the data pointer must be to
254 * dynamically allocated memory (i.e. memory that can be successfully DMAed to a
255 * device).
256 *
257 * The "whole" message must be properly received from the device in order for
258 * this function to be successful. If a device returns less than the expected
259 * amount of data, then the function will fail. Do not use this for messages
260 * where a variable amount of data might be returned.
261 *
262 * Return: If successful, 0 is returned, Otherwise, a negative error number.
263 */
264int usb_control_msg_recv(struct usb_device *dev, __u8 endpoint, __u8 request,
265 __u8 requesttype, __u16 value, __u16 index,
266 void *driver_data, __u16 size, int timeout,
267 gfp_t memflags)
268{
269 unsigned int pipe = usb_rcvctrlpipe(dev, endpoint);
270 int ret;
271 u8 *data;
272
273 if (!size || !driver_data)
274 return -EINVAL;
275
276 data = kmalloc(size, memflags);
277 if (!data)
278 return -ENOMEM;
279
280 ret = usb_control_msg(dev, pipe, request, requesttype, value, index,
281 data, size, timeout);
282
283 if (ret < 0)
284 goto exit;
285
286 if (ret == size) {
287 memcpy(to: driver_data, from: data, len: size);
288 ret = 0;
289 } else {
290 ret = -EREMOTEIO;
291 }
292
293exit:
294 kfree(objp: data);
295 return ret;
296}
297EXPORT_SYMBOL_GPL(usb_control_msg_recv);
298
299/**
300 * usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion
301 * @usb_dev: pointer to the usb device to send the message to
302 * @pipe: endpoint "pipe" to send the message to
303 * @data: pointer to the data to send
304 * @len: length in bytes of the data to send
305 * @actual_length: pointer to a location to put the actual length transferred
306 * in bytes
307 * @timeout: time in msecs to wait for the message to complete before
308 * timing out (if 0 the wait is forever)
309 *
310 * Context: task context, might sleep.
311 *
312 * This function sends a simple interrupt message to a specified endpoint and
313 * waits for the message to complete, or timeout.
314 *
315 * Don't use this function from within an interrupt context. If you need
316 * an asynchronous message, or need to send a message from within interrupt
317 * context, use usb_submit_urb() If a thread in your driver uses this call,
318 * make sure your disconnect() method can wait for it to complete. Since you
319 * don't have a handle on the URB used, you can't cancel the request.
320 *
321 * Return:
322 * If successful, 0. Otherwise a negative error number. The number of actual
323 * bytes transferred will be stored in the @actual_length parameter.
324 */
325int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe,
326 void *data, int len, int *actual_length, int timeout)
327{
328 return usb_bulk_msg(usb_dev, pipe, data, len, actual_length, timeout);
329}
330EXPORT_SYMBOL_GPL(usb_interrupt_msg);
331
332/**
333 * usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
334 * @usb_dev: pointer to the usb device to send the message to
335 * @pipe: endpoint "pipe" to send the message to
336 * @data: pointer to the data to send
337 * @len: length in bytes of the data to send
338 * @actual_length: pointer to a location to put the actual length transferred
339 * in bytes
340 * @timeout: time in msecs to wait for the message to complete before
341 * timing out (if 0 the wait is forever)
342 *
343 * Context: task context, might sleep.
344 *
345 * This function sends a simple bulk message to a specified endpoint
346 * and waits for the message to complete, or timeout.
347 *
348 * Don't use this function from within an interrupt context. If you need
349 * an asynchronous message, or need to send a message from within interrupt
350 * context, use usb_submit_urb() If a thread in your driver uses this call,
351 * make sure your disconnect() method can wait for it to complete. Since you
352 * don't have a handle on the URB used, you can't cancel the request.
353 *
354 * Because there is no usb_interrupt_msg() and no USBDEVFS_INTERRUPT ioctl,
355 * users are forced to abuse this routine by using it to submit URBs for
356 * interrupt endpoints. We will take the liberty of creating an interrupt URB
357 * (with the default interval) if the target is an interrupt endpoint.
358 *
359 * Return:
360 * If successful, 0. Otherwise a negative error number. The number of actual
361 * bytes transferred will be stored in the @actual_length parameter.
362 *
363 */
364int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe,
365 void *data, int len, int *actual_length, int timeout)
366{
367 struct urb *urb;
368 struct usb_host_endpoint *ep;
369
370 ep = usb_pipe_endpoint(dev: usb_dev, pipe);
371 if (!ep || len < 0)
372 return -EINVAL;
373
374 urb = usb_alloc_urb(iso_packets: 0, GFP_KERNEL);
375 if (!urb)
376 return -ENOMEM;
377
378 if ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
379 USB_ENDPOINT_XFER_INT) {
380 pipe = (pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30);
381 usb_fill_int_urb(urb, dev: usb_dev, pipe, transfer_buffer: data, buffer_length: len,
382 complete_fn: usb_api_blocking_completion, NULL,
383 interval: ep->desc.bInterval);
384 } else
385 usb_fill_bulk_urb(urb, dev: usb_dev, pipe, transfer_buffer: data, buffer_length: len,
386 complete_fn: usb_api_blocking_completion, NULL);
387
388 return usb_start_wait_urb(urb, timeout, actual_length);
389}
390EXPORT_SYMBOL_GPL(usb_bulk_msg);
391
392/*-------------------------------------------------------------------*/
393
394static void sg_clean(struct usb_sg_request *io)
395{
396 if (io->urbs) {
397 while (io->entries--)
398 usb_free_urb(urb: io->urbs[io->entries]);
399 kfree(objp: io->urbs);
400 io->urbs = NULL;
401 }
402 io->dev = NULL;
403}
404
405static void sg_complete(struct urb *urb)
406{
407 unsigned long flags;
408 struct usb_sg_request *io = urb->context;
409 int status = urb->status;
410
411 spin_lock_irqsave(&io->lock, flags);
412
413 /* In 2.5 we require hcds' endpoint queues not to progress after fault
414 * reports, until the completion callback (this!) returns. That lets
415 * device driver code (like this routine) unlink queued urbs first,
416 * if it needs to, since the HC won't work on them at all. So it's
417 * not possible for page N+1 to overwrite page N, and so on.
418 *
419 * That's only for "hard" faults; "soft" faults (unlinks) sometimes
420 * complete before the HCD can get requests away from hardware,
421 * though never during cleanup after a hard fault.
422 */
423 if (io->status
424 && (io->status != -ECONNRESET
425 || status != -ECONNRESET)
426 && urb->actual_length) {
427 dev_err(io->dev->bus->controller,
428 "dev %s ep%d%s scatterlist error %d/%d\n",
429 io->dev->devpath,
430 usb_endpoint_num(&urb->ep->desc),
431 usb_urb_dir_in(urb) ? "in" : "out",
432 status, io->status);
433 /* BUG (); */
434 }
435
436 if (io->status == 0 && status && status != -ECONNRESET) {
437 int i, found, retval;
438
439 io->status = status;
440
441 /* the previous urbs, and this one, completed already.
442 * unlink pending urbs so they won't rx/tx bad data.
443 * careful: unlink can sometimes be synchronous...
444 */
445 spin_unlock_irqrestore(lock: &io->lock, flags);
446 for (i = 0, found = 0; i < io->entries; i++) {
447 if (!io->urbs[i])
448 continue;
449 if (found) {
450 usb_block_urb(urb: io->urbs[i]);
451 retval = usb_unlink_urb(urb: io->urbs[i]);
452 if (retval != -EINPROGRESS &&
453 retval != -ENODEV &&
454 retval != -EBUSY &&
455 retval != -EIDRM)
456 dev_err(&io->dev->dev,
457 "%s, unlink --> %d\n",
458 __func__, retval);
459 } else if (urb == io->urbs[i])
460 found = 1;
461 }
462 spin_lock_irqsave(&io->lock, flags);
463 }
464
465 /* on the last completion, signal usb_sg_wait() */
466 io->bytes += urb->actual_length;
467 io->count--;
468 if (!io->count)
469 complete(&io->complete);
470
471 spin_unlock_irqrestore(lock: &io->lock, flags);
472}
473
474
475/**
476 * usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
477 * @io: request block being initialized. until usb_sg_wait() returns,
478 * treat this as a pointer to an opaque block of memory,
479 * @dev: the usb device that will send or receive the data
480 * @pipe: endpoint "pipe" used to transfer the data
481 * @period: polling rate for interrupt endpoints, in frames or
482 * (for high speed endpoints) microframes; ignored for bulk
483 * @sg: scatterlist entries
484 * @nents: how many entries in the scatterlist
485 * @length: how many bytes to send from the scatterlist, or zero to
486 * send every byte identified in the list.
487 * @mem_flags: SLAB_* flags affecting memory allocations in this call
488 *
489 * This initializes a scatter/gather request, allocating resources such as
490 * I/O mappings and urb memory (except maybe memory used by USB controller
491 * drivers).
492 *
493 * The request must be issued using usb_sg_wait(), which waits for the I/O to
494 * complete (or to be canceled) and then cleans up all resources allocated by
495 * usb_sg_init().
496 *
497 * The request may be canceled with usb_sg_cancel(), either before or after
498 * usb_sg_wait() is called.
499 *
500 * Return: Zero for success, else a negative errno value.
501 */
502int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
503 unsigned pipe, unsigned period, struct scatterlist *sg,
504 int nents, size_t length, gfp_t mem_flags)
505{
506 int i;
507 int urb_flags;
508 int use_sg;
509
510 if (!io || !dev || !sg
511 || usb_pipecontrol(pipe)
512 || usb_pipeisoc(pipe)
513 || nents <= 0)
514 return -EINVAL;
515
516 spin_lock_init(&io->lock);
517 io->dev = dev;
518 io->pipe = pipe;
519
520 if (dev->bus->sg_tablesize > 0) {
521 use_sg = true;
522 io->entries = 1;
523 } else {
524 use_sg = false;
525 io->entries = nents;
526 }
527
528 /* initialize all the urbs we'll use */
529 io->urbs = kmalloc_array(io->entries, sizeof(*io->urbs), mem_flags);
530 if (!io->urbs)
531 goto nomem;
532
533 urb_flags = URB_NO_INTERRUPT;
534 if (usb_pipein(pipe))
535 urb_flags |= URB_SHORT_NOT_OK;
536
537 for_each_sg(sg, sg, io->entries, i) {
538 struct urb *urb;
539 unsigned len;
540
541 urb = usb_alloc_urb(iso_packets: 0, mem_flags);
542 if (!urb) {
543 io->entries = i;
544 goto nomem;
545 }
546 io->urbs[i] = urb;
547
548 urb->dev = NULL;
549 urb->pipe = pipe;
550 urb->interval = period;
551 urb->transfer_flags = urb_flags;
552 urb->complete = sg_complete;
553 urb->context = io;
554 urb->sg = sg;
555
556 if (use_sg) {
557 /* There is no single transfer buffer */
558 urb->transfer_buffer = NULL;
559 urb->num_sgs = nents;
560
561 /* A length of zero means transfer the whole sg list */
562 len = length;
563 if (len == 0) {
564 struct scatterlist *sg2;
565 int j;
566
567 for_each_sg(sg, sg2, nents, j)
568 len += sg2->length;
569 }
570 } else {
571 /*
572 * Some systems can't use DMA; they use PIO instead.
573 * For their sakes, transfer_buffer is set whenever
574 * possible.
575 */
576 if (!PageHighMem(page: sg_page(sg)))
577 urb->transfer_buffer = sg_virt(sg);
578 else
579 urb->transfer_buffer = NULL;
580
581 len = sg->length;
582 if (length) {
583 len = min_t(size_t, len, length);
584 length -= len;
585 if (length == 0)
586 io->entries = i + 1;
587 }
588 }
589 urb->transfer_buffer_length = len;
590 }
591 io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT;
592
593 /* transaction state */
594 io->count = io->entries;
595 io->status = 0;
596 io->bytes = 0;
597 init_completion(x: &io->complete);
598 return 0;
599
600nomem:
601 sg_clean(io);
602 return -ENOMEM;
603}
604EXPORT_SYMBOL_GPL(usb_sg_init);
605
606/**
607 * usb_sg_wait - synchronously execute scatter/gather request
608 * @io: request block handle, as initialized with usb_sg_init().
609 * some fields become accessible when this call returns.
610 *
611 * Context: task context, might sleep.
612 *
613 * This function blocks until the specified I/O operation completes. It
614 * leverages the grouping of the related I/O requests to get good transfer
615 * rates, by queueing the requests. At higher speeds, such queuing can
616 * significantly improve USB throughput.
617 *
618 * There are three kinds of completion for this function.
619 *
620 * (1) success, where io->status is zero. The number of io->bytes
621 * transferred is as requested.
622 * (2) error, where io->status is a negative errno value. The number
623 * of io->bytes transferred before the error is usually less
624 * than requested, and can be nonzero.
625 * (3) cancellation, a type of error with status -ECONNRESET that
626 * is initiated by usb_sg_cancel().
627 *
628 * When this function returns, all memory allocated through usb_sg_init() or
629 * this call will have been freed. The request block parameter may still be
630 * passed to usb_sg_cancel(), or it may be freed. It could also be
631 * reinitialized and then reused.
632 *
633 * Data Transfer Rates:
634 *
635 * Bulk transfers are valid for full or high speed endpoints.
636 * The best full speed data rate is 19 packets of 64 bytes each
637 * per frame, or 1216 bytes per millisecond.
638 * The best high speed data rate is 13 packets of 512 bytes each
639 * per microframe, or 52 KBytes per millisecond.
640 *
641 * The reason to use interrupt transfers through this API would most likely
642 * be to reserve high speed bandwidth, where up to 24 KBytes per millisecond
643 * could be transferred. That capability is less useful for low or full
644 * speed interrupt endpoints, which allow at most one packet per millisecond,
645 * of at most 8 or 64 bytes (respectively).
646 *
647 * It is not necessary to call this function to reserve bandwidth for devices
648 * under an xHCI host controller, as the bandwidth is reserved when the
649 * configuration or interface alt setting is selected.
650 */
651void usb_sg_wait(struct usb_sg_request *io)
652{
653 int i;
654 int entries = io->entries;
655
656 /* queue the urbs. */
657 spin_lock_irq(lock: &io->lock);
658 i = 0;
659 while (i < entries && !io->status) {
660 int retval;
661
662 io->urbs[i]->dev = io->dev;
663 spin_unlock_irq(lock: &io->lock);
664
665 retval = usb_submit_urb(urb: io->urbs[i], GFP_NOIO);
666
667 switch (retval) {
668 /* maybe we retrying will recover */
669 case -ENXIO: /* hc didn't queue this one */
670 case -EAGAIN:
671 case -ENOMEM:
672 retval = 0;
673 yield();
674 break;
675
676 /* no error? continue immediately.
677 *
678 * NOTE: to work better with UHCI (4K I/O buffer may
679 * need 3K of TDs) it may be good to limit how many
680 * URBs are queued at once; N milliseconds?
681 */
682 case 0:
683 ++i;
684 cpu_relax();
685 break;
686
687 /* fail any uncompleted urbs */
688 default:
689 io->urbs[i]->status = retval;
690 dev_dbg(&io->dev->dev, "%s, submit --> %d\n",
691 __func__, retval);
692 usb_sg_cancel(io);
693 }
694 spin_lock_irq(lock: &io->lock);
695 if (retval && (io->status == 0 || io->status == -ECONNRESET))
696 io->status = retval;
697 }
698 io->count -= entries - i;
699 if (io->count == 0)
700 complete(&io->complete);
701 spin_unlock_irq(lock: &io->lock);
702
703 /* OK, yes, this could be packaged as non-blocking.
704 * So could the submit loop above ... but it's easier to
705 * solve neither problem than to solve both!
706 */
707 wait_for_completion(&io->complete);
708
709 sg_clean(io);
710}
711EXPORT_SYMBOL_GPL(usb_sg_wait);
712
713/**
714 * usb_sg_cancel - stop scatter/gather i/o issued by usb_sg_wait()
715 * @io: request block, initialized with usb_sg_init()
716 *
717 * This stops a request after it has been started by usb_sg_wait().
718 * It can also prevents one initialized by usb_sg_init() from starting,
719 * so that call just frees resources allocated to the request.
720 */
721void usb_sg_cancel(struct usb_sg_request *io)
722{
723 unsigned long flags;
724 int i, retval;
725
726 spin_lock_irqsave(&io->lock, flags);
727 if (io->status || io->count == 0) {
728 spin_unlock_irqrestore(lock: &io->lock, flags);
729 return;
730 }
731 /* shut everything down */
732 io->status = -ECONNRESET;
733 io->count++; /* Keep the request alive until we're done */
734 spin_unlock_irqrestore(lock: &io->lock, flags);
735
736 for (i = io->entries - 1; i >= 0; --i) {
737 usb_block_urb(urb: io->urbs[i]);
738
739 retval = usb_unlink_urb(urb: io->urbs[i]);
740 if (retval != -EINPROGRESS
741 && retval != -ENODEV
742 && retval != -EBUSY
743 && retval != -EIDRM)
744 dev_warn(&io->dev->dev, "%s, unlink --> %d\n",
745 __func__, retval);
746 }
747
748 spin_lock_irqsave(&io->lock, flags);
749 io->count--;
750 if (!io->count)
751 complete(&io->complete);
752 spin_unlock_irqrestore(lock: &io->lock, flags);
753}
754EXPORT_SYMBOL_GPL(usb_sg_cancel);
755
756/*-------------------------------------------------------------------*/
757
758/**
759 * usb_get_descriptor - issues a generic GET_DESCRIPTOR request
760 * @dev: the device whose descriptor is being retrieved
761 * @type: the descriptor type (USB_DT_*)
762 * @index: the number of the descriptor
763 * @buf: where to put the descriptor
764 * @size: how big is "buf"?
765 *
766 * Context: task context, might sleep.
767 *
768 * Gets a USB descriptor. Convenience functions exist to simplify
769 * getting some types of descriptors. Use
770 * usb_get_string() or usb_string() for USB_DT_STRING.
771 * Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG)
772 * are part of the device structure.
773 * In addition to a number of USB-standard descriptors, some
774 * devices also use class-specific or vendor-specific descriptors.
775 *
776 * This call is synchronous, and may not be used in an interrupt context.
777 *
778 * Return: The number of bytes received on success, or else the status code
779 * returned by the underlying usb_control_msg() call.
780 */
781int usb_get_descriptor(struct usb_device *dev, unsigned char type,
782 unsigned char index, void *buf, int size)
783{
784 int i;
785 int result;
786
787 if (size <= 0) /* No point in asking for no data */
788 return -EINVAL;
789
790 memset(s: buf, c: 0, n: size); /* Make sure we parse really received data */
791
792 for (i = 0; i < 3; ++i) {
793 /* retry on length 0 or error; some devices are flakey */
794 result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
795 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
796 (type << 8) + index, 0, buf, size,
797 USB_CTRL_GET_TIMEOUT);
798 if (result <= 0 && result != -ETIMEDOUT)
799 continue;
800 if (result > 1 && ((u8 *)buf)[1] != type) {
801 result = -ENODATA;
802 continue;
803 }
804 break;
805 }
806 return result;
807}
808EXPORT_SYMBOL_GPL(usb_get_descriptor);
809
810/**
811 * usb_get_string - gets a string descriptor
812 * @dev: the device whose string descriptor is being retrieved
813 * @langid: code for language chosen (from string descriptor zero)
814 * @index: the number of the descriptor
815 * @buf: where to put the string
816 * @size: how big is "buf"?
817 *
818 * Context: task context, might sleep.
819 *
820 * Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character,
821 * in little-endian byte order).
822 * The usb_string() function will often be a convenient way to turn
823 * these strings into kernel-printable form.
824 *
825 * Strings may be referenced in device, configuration, interface, or other
826 * descriptors, and could also be used in vendor-specific ways.
827 *
828 * This call is synchronous, and may not be used in an interrupt context.
829 *
830 * Return: The number of bytes received on success, or else the status code
831 * returned by the underlying usb_control_msg() call.
832 */
833static int usb_get_string(struct usb_device *dev, unsigned short langid,
834 unsigned char index, void *buf, int size)
835{
836 int i;
837 int result;
838
839 if (size <= 0) /* No point in asking for no data */
840 return -EINVAL;
841
842 for (i = 0; i < 3; ++i) {
843 /* retry on length 0 or stall; some devices are flakey */
844 result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
845 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
846 (USB_DT_STRING << 8) + index, langid, buf, size,
847 USB_CTRL_GET_TIMEOUT);
848 if (result == 0 || result == -EPIPE)
849 continue;
850 if (result > 1 && ((u8 *) buf)[1] != USB_DT_STRING) {
851 result = -ENODATA;
852 continue;
853 }
854 break;
855 }
856 return result;
857}
858
859static void usb_try_string_workarounds(unsigned char *buf, int *length)
860{
861 int newlength, oldlength = *length;
862
863 for (newlength = 2; newlength + 1 < oldlength; newlength += 2)
864 if (!isprint(buf[newlength]) || buf[newlength + 1])
865 break;
866
867 if (newlength > 2) {
868 buf[0] = newlength;
869 *length = newlength;
870 }
871}
872
873static int usb_string_sub(struct usb_device *dev, unsigned int langid,
874 unsigned int index, unsigned char *buf)
875{
876 int rc;
877
878 /* Try to read the string descriptor by asking for the maximum
879 * possible number of bytes */
880 if (dev->quirks & USB_QUIRK_STRING_FETCH_255)
881 rc = -EIO;
882 else
883 rc = usb_get_string(dev, langid, index, buf, size: 255);
884
885 /* If that failed try to read the descriptor length, then
886 * ask for just that many bytes */
887 if (rc < 2) {
888 rc = usb_get_string(dev, langid, index, buf, size: 2);
889 if (rc == 2)
890 rc = usb_get_string(dev, langid, index, buf, size: buf[0]);
891 }
892
893 if (rc >= 2) {
894 if (!buf[0] && !buf[1])
895 usb_try_string_workarounds(buf, length: &rc);
896
897 /* There might be extra junk at the end of the descriptor */
898 if (buf[0] < rc)
899 rc = buf[0];
900
901 rc = rc - (rc & 1); /* force a multiple of two */
902 }
903
904 if (rc < 2)
905 rc = (rc < 0 ? rc : -EINVAL);
906
907 return rc;
908}
909
910static int usb_get_langid(struct usb_device *dev, unsigned char *tbuf)
911{
912 int err;
913
914 if (dev->have_langid)
915 return 0;
916
917 if (dev->string_langid < 0)
918 return -EPIPE;
919
920 err = usb_string_sub(dev, langid: 0, index: 0, buf: tbuf);
921
922 /* If the string was reported but is malformed, default to english
923 * (0x0409) */
924 if (err == -ENODATA || (err > 0 && err < 4)) {
925 dev->string_langid = 0x0409;
926 dev->have_langid = 1;
927 dev_err(&dev->dev,
928 "language id specifier not provided by device, defaulting to English\n");
929 return 0;
930 }
931
932 /* In case of all other errors, we assume the device is not able to
933 * deal with strings at all. Set string_langid to -1 in order to
934 * prevent any string to be retrieved from the device */
935 if (err < 0) {
936 dev_info(&dev->dev, "string descriptor 0 read error: %d\n",
937 err);
938 dev->string_langid = -1;
939 return -EPIPE;
940 }
941
942 /* always use the first langid listed */
943 dev->string_langid = tbuf[2] | (tbuf[3] << 8);
944 dev->have_langid = 1;
945 dev_dbg(&dev->dev, "default language 0x%04x\n",
946 dev->string_langid);
947 return 0;
948}
949
950/**
951 * usb_string - returns UTF-8 version of a string descriptor
952 * @dev: the device whose string descriptor is being retrieved
953 * @index: the number of the descriptor
954 * @buf: where to put the string
955 * @size: how big is "buf"?
956 *
957 * Context: task context, might sleep.
958 *
959 * This converts the UTF-16LE encoded strings returned by devices, from
960 * usb_get_string_descriptor(), to null-terminated UTF-8 encoded ones
961 * that are more usable in most kernel contexts. Note that this function
962 * chooses strings in the first language supported by the device.
963 *
964 * This call is synchronous, and may not be used in an interrupt context.
965 *
966 * Return: length of the string (>= 0) or usb_control_msg status (< 0).
967 */
968int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
969{
970 unsigned char *tbuf;
971 int err;
972
973 if (dev->state == USB_STATE_SUSPENDED)
974 return -EHOSTUNREACH;
975 if (size <= 0 || !buf)
976 return -EINVAL;
977 buf[0] = 0;
978 if (index <= 0 || index >= 256)
979 return -EINVAL;
980 tbuf = kmalloc(256, GFP_NOIO);
981 if (!tbuf)
982 return -ENOMEM;
983
984 err = usb_get_langid(dev, tbuf);
985 if (err < 0)
986 goto errout;
987
988 err = usb_string_sub(dev, langid: dev->string_langid, index, buf: tbuf);
989 if (err < 0)
990 goto errout;
991
992 size--; /* leave room for trailing NULL char in output buffer */
993 err = utf16s_to_utf8s(pwcs: (wchar_t *) &tbuf[2], len: (err - 2) / 2,
994 endian: UTF16_LITTLE_ENDIAN, s: buf, maxlen: size);
995 buf[err] = 0;
996
997 if (tbuf[1] != USB_DT_STRING)
998 dev_dbg(&dev->dev,
999 "wrong descriptor type %02x for string %d (\"%s\")\n",
1000 tbuf[1], index, buf);
1001
1002 errout:
1003 kfree(objp: tbuf);
1004 return err;
1005}
1006EXPORT_SYMBOL_GPL(usb_string);
1007
1008/* one UTF-8-encoded 16-bit character has at most three bytes */
1009#define MAX_USB_STRING_SIZE (127 * 3 + 1)
1010
1011/**
1012 * usb_cache_string - read a string descriptor and cache it for later use
1013 * @udev: the device whose string descriptor is being read
1014 * @index: the descriptor index
1015 *
1016 * Return: A pointer to a kmalloc'ed buffer containing the descriptor string,
1017 * or %NULL if the index is 0 or the string could not be read.
1018 */
1019char *usb_cache_string(struct usb_device *udev, int index)
1020{
1021 char *buf;
1022 char *smallbuf = NULL;
1023 int len;
1024
1025 if (index <= 0)
1026 return NULL;
1027
1028 buf = kmalloc(MAX_USB_STRING_SIZE, GFP_NOIO);
1029 if (buf) {
1030 len = usb_string(udev, index, buf, MAX_USB_STRING_SIZE);
1031 if (len > 0) {
1032 smallbuf = kmalloc(++len, GFP_NOIO);
1033 if (!smallbuf)
1034 return buf;
1035 memcpy(to: smallbuf, from: buf, len);
1036 }
1037 kfree(objp: buf);
1038 }
1039 return smallbuf;
1040}
1041EXPORT_SYMBOL_GPL(usb_cache_string);
1042
1043/*
1044 * usb_get_device_descriptor - read the device descriptor
1045 * @udev: the device whose device descriptor should be read
1046 *
1047 * Context: task context, might sleep.
1048 *
1049 * Not exported, only for use by the core. If drivers really want to read
1050 * the device descriptor directly, they can call usb_get_descriptor() with
1051 * type = USB_DT_DEVICE and index = 0.
1052 *
1053 * Returns: a pointer to a dynamically allocated usb_device_descriptor
1054 * structure (which the caller must deallocate), or an ERR_PTR value.
1055 */
1056struct usb_device_descriptor *usb_get_device_descriptor(struct usb_device *udev)
1057{
1058 struct usb_device_descriptor *desc;
1059 int ret;
1060
1061 desc = kmalloc(sizeof(*desc), GFP_NOIO);
1062 if (!desc)
1063 return ERR_PTR(error: -ENOMEM);
1064
1065 ret = usb_get_descriptor(udev, USB_DT_DEVICE, 0, desc, sizeof(*desc));
1066 if (ret == sizeof(*desc))
1067 return desc;
1068
1069 if (ret >= 0)
1070 ret = -EMSGSIZE;
1071 kfree(objp: desc);
1072 return ERR_PTR(error: ret);
1073}
1074
1075/*
1076 * usb_set_isoch_delay - informs the device of the packet transmit delay
1077 * @dev: the device whose delay is to be informed
1078 * Context: task context, might sleep
1079 *
1080 * Since this is an optional request, we don't bother if it fails.
1081 */
1082int usb_set_isoch_delay(struct usb_device *dev)
1083{
1084 /* skip hub devices */
1085 if (dev->descriptor.bDeviceClass == USB_CLASS_HUB)
1086 return 0;
1087
1088 /* skip non-SS/non-SSP devices */
1089 if (dev->speed < USB_SPEED_SUPER)
1090 return 0;
1091
1092 return usb_control_msg_send(dev, 0,
1093 USB_REQ_SET_ISOCH_DELAY,
1094 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
1095 dev->hub_delay, 0, NULL, 0,
1096 USB_CTRL_SET_TIMEOUT,
1097 GFP_NOIO);
1098}
1099
1100/**
1101 * usb_get_status - issues a GET_STATUS call
1102 * @dev: the device whose status is being checked
1103 * @recip: USB_RECIP_*; for device, interface, or endpoint
1104 * @type: USB_STATUS_TYPE_*; for standard or PTM status types
1105 * @target: zero (for device), else interface or endpoint number
1106 * @data: pointer to two bytes of bitmap data
1107 *
1108 * Context: task context, might sleep.
1109 *
1110 * Returns device, interface, or endpoint status. Normally only of
1111 * interest to see if the device is self powered, or has enabled the
1112 * remote wakeup facility; or whether a bulk or interrupt endpoint
1113 * is halted ("stalled").
1114 *
1115 * Bits in these status bitmaps are set using the SET_FEATURE request,
1116 * and cleared using the CLEAR_FEATURE request. The usb_clear_halt()
1117 * function should be used to clear halt ("stall") status.
1118 *
1119 * This call is synchronous, and may not be used in an interrupt context.
1120 *
1121 * Returns 0 and the status value in *@data (in host byte order) on success,
1122 * or else the status code from the underlying usb_control_msg() call.
1123 */
1124int usb_get_status(struct usb_device *dev, int recip, int type, int target,
1125 void *data)
1126{
1127 int ret;
1128 void *status;
1129 int length;
1130
1131 switch (type) {
1132 case USB_STATUS_TYPE_STANDARD:
1133 length = 2;
1134 break;
1135 case USB_STATUS_TYPE_PTM:
1136 if (recip != USB_RECIP_DEVICE)
1137 return -EINVAL;
1138
1139 length = 4;
1140 break;
1141 default:
1142 return -EINVAL;
1143 }
1144
1145 status = kmalloc(length, GFP_KERNEL);
1146 if (!status)
1147 return -ENOMEM;
1148
1149 ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
1150 USB_REQ_GET_STATUS, USB_DIR_IN | recip, USB_STATUS_TYPE_STANDARD,
1151 target, status, length, USB_CTRL_GET_TIMEOUT);
1152
1153 switch (ret) {
1154 case 4:
1155 if (type != USB_STATUS_TYPE_PTM) {
1156 ret = -EIO;
1157 break;
1158 }
1159
1160 *(u32 *) data = le32_to_cpu(*(__le32 *) status);
1161 ret = 0;
1162 break;
1163 case 2:
1164 if (type != USB_STATUS_TYPE_STANDARD) {
1165 ret = -EIO;
1166 break;
1167 }
1168
1169 *(u16 *) data = le16_to_cpu(*(__le16 *) status);
1170 ret = 0;
1171 break;
1172 default:
1173 ret = -EIO;
1174 }
1175
1176 kfree(objp: status);
1177 return ret;
1178}
1179EXPORT_SYMBOL_GPL(usb_get_status);
1180
1181/**
1182 * usb_clear_halt - tells device to clear endpoint halt/stall condition
1183 * @dev: device whose endpoint is halted
1184 * @pipe: endpoint "pipe" being cleared
1185 *
1186 * Context: task context, might sleep.
1187 *
1188 * This is used to clear halt conditions for bulk and interrupt endpoints,
1189 * as reported by URB completion status. Endpoints that are halted are
1190 * sometimes referred to as being "stalled". Such endpoints are unable
1191 * to transmit or receive data until the halt status is cleared. Any URBs
1192 * queued for such an endpoint should normally be unlinked by the driver
1193 * before clearing the halt condition, as described in sections 5.7.5
1194 * and 5.8.5 of the USB 2.0 spec.
1195 *
1196 * Note that control and isochronous endpoints don't halt, although control
1197 * endpoints report "protocol stall" (for unsupported requests) using the
1198 * same status code used to report a true stall.
1199 *
1200 * This call is synchronous, and may not be used in an interrupt context.
1201 * If a thread in your driver uses this call, make sure your disconnect()
1202 * method can wait for it to complete.
1203 *
1204 * Return: Zero on success, or else the status code returned by the
1205 * underlying usb_control_msg() call.
1206 */
1207int usb_clear_halt(struct usb_device *dev, int pipe)
1208{
1209 int result;
1210 int endp = usb_pipeendpoint(pipe);
1211
1212 if (usb_pipein(pipe))
1213 endp |= USB_DIR_IN;
1214
1215 /* we don't care if it wasn't halted first. in fact some devices
1216 * (like some ibmcam model 1 units) seem to expect hosts to make
1217 * this request for iso endpoints, which can't halt!
1218 */
1219 result = usb_control_msg_send(dev, 0,
1220 USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
1221 USB_ENDPOINT_HALT, endp, NULL, 0,
1222 USB_CTRL_SET_TIMEOUT, GFP_NOIO);
1223
1224 /* don't un-halt or force to DATA0 except on success */
1225 if (result)
1226 return result;
1227
1228 /* NOTE: seems like Microsoft and Apple don't bother verifying
1229 * the clear "took", so some devices could lock up if you check...
1230 * such as the Hagiwara FlashGate DUAL. So we won't bother.
1231 *
1232 * NOTE: make sure the logic here doesn't diverge much from
1233 * the copy in usb-storage, for as long as we need two copies.
1234 */
1235
1236 usb_reset_endpoint(dev, epaddr: endp);
1237
1238 return 0;
1239}
1240EXPORT_SYMBOL_GPL(usb_clear_halt);
1241
1242static int create_intf_ep_devs(struct usb_interface *intf)
1243{
1244 struct usb_device *udev = interface_to_usbdev(intf);
1245 struct usb_host_interface *alt = intf->cur_altsetting;
1246 int i;
1247
1248 if (intf->ep_devs_created || intf->unregistering)
1249 return 0;
1250
1251 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1252 (void) usb_create_ep_devs(parent: &intf->dev, endpoint: &alt->endpoint[i], udev);
1253 intf->ep_devs_created = 1;
1254 return 0;
1255}
1256
1257static void remove_intf_ep_devs(struct usb_interface *intf)
1258{
1259 struct usb_host_interface *alt = intf->cur_altsetting;
1260 int i;
1261
1262 if (!intf->ep_devs_created)
1263 return;
1264
1265 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1266 usb_remove_ep_devs(endpoint: &alt->endpoint[i]);
1267 intf->ep_devs_created = 0;
1268}
1269
1270/**
1271 * usb_disable_endpoint -- Disable an endpoint by address
1272 * @dev: the device whose endpoint is being disabled
1273 * @epaddr: the endpoint's address. Endpoint number for output,
1274 * endpoint number + USB_DIR_IN for input
1275 * @reset_hardware: flag to erase any endpoint state stored in the
1276 * controller hardware
1277 *
1278 * Disables the endpoint for URB submission and nukes all pending URBs.
1279 * If @reset_hardware is set then also deallocates hcd/hardware state
1280 * for the endpoint.
1281 */
1282void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr,
1283 bool reset_hardware)
1284{
1285 unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1286 struct usb_host_endpoint *ep;
1287
1288 if (!dev)
1289 return;
1290
1291 if (usb_endpoint_out(epaddr)) {
1292 ep = dev->ep_out[epnum];
1293 if (reset_hardware && epnum != 0)
1294 dev->ep_out[epnum] = NULL;
1295 } else {
1296 ep = dev->ep_in[epnum];
1297 if (reset_hardware && epnum != 0)
1298 dev->ep_in[epnum] = NULL;
1299 }
1300 if (ep) {
1301 ep->enabled = 0;
1302 usb_hcd_flush_endpoint(udev: dev, ep);
1303 if (reset_hardware)
1304 usb_hcd_disable_endpoint(udev: dev, ep);
1305 }
1306}
1307
1308/**
1309 * usb_reset_endpoint - Reset an endpoint's state.
1310 * @dev: the device whose endpoint is to be reset
1311 * @epaddr: the endpoint's address. Endpoint number for output,
1312 * endpoint number + USB_DIR_IN for input
1313 *
1314 * Resets any host-side endpoint state such as the toggle bit,
1315 * sequence number or current window.
1316 */
1317void usb_reset_endpoint(struct usb_device *dev, unsigned int epaddr)
1318{
1319 unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1320 struct usb_host_endpoint *ep;
1321
1322 if (usb_endpoint_out(epaddr))
1323 ep = dev->ep_out[epnum];
1324 else
1325 ep = dev->ep_in[epnum];
1326 if (ep)
1327 usb_hcd_reset_endpoint(udev: dev, ep);
1328}
1329EXPORT_SYMBOL_GPL(usb_reset_endpoint);
1330
1331
1332/**
1333 * usb_disable_interface -- Disable all endpoints for an interface
1334 * @dev: the device whose interface is being disabled
1335 * @intf: pointer to the interface descriptor
1336 * @reset_hardware: flag to erase any endpoint state stored in the
1337 * controller hardware
1338 *
1339 * Disables all the endpoints for the interface's current altsetting.
1340 */
1341void usb_disable_interface(struct usb_device *dev, struct usb_interface *intf,
1342 bool reset_hardware)
1343{
1344 struct usb_host_interface *alt = intf->cur_altsetting;
1345 int i;
1346
1347 for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
1348 usb_disable_endpoint(dev,
1349 epaddr: alt->endpoint[i].desc.bEndpointAddress,
1350 reset_hardware);
1351 }
1352}
1353
1354/*
1355 * usb_disable_device_endpoints -- Disable all endpoints for a device
1356 * @dev: the device whose endpoints are being disabled
1357 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1358 */
1359static void usb_disable_device_endpoints(struct usb_device *dev, int skip_ep0)
1360{
1361 struct usb_hcd *hcd = bus_to_hcd(bus: dev->bus);
1362 int i;
1363
1364 if (hcd->driver->check_bandwidth) {
1365 /* First pass: Cancel URBs, leave endpoint pointers intact. */
1366 for (i = skip_ep0; i < 16; ++i) {
1367 usb_disable_endpoint(dev, epaddr: i, reset_hardware: false);
1368 usb_disable_endpoint(dev, epaddr: i + USB_DIR_IN, reset_hardware: false);
1369 }
1370 /* Remove endpoints from the host controller internal state */
1371 mutex_lock(lock: hcd->bandwidth_mutex);
1372 usb_hcd_alloc_bandwidth(udev: dev, NULL, NULL, NULL);
1373 mutex_unlock(lock: hcd->bandwidth_mutex);
1374 }
1375 /* Second pass: remove endpoint pointers */
1376 for (i = skip_ep0; i < 16; ++i) {
1377 usb_disable_endpoint(dev, epaddr: i, reset_hardware: true);
1378 usb_disable_endpoint(dev, epaddr: i + USB_DIR_IN, reset_hardware: true);
1379 }
1380}
1381
1382/**
1383 * usb_disable_device - Disable all the endpoints for a USB device
1384 * @dev: the device whose endpoints are being disabled
1385 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1386 *
1387 * Disables all the device's endpoints, potentially including endpoint 0.
1388 * Deallocates hcd/hardware state for the endpoints (nuking all or most
1389 * pending urbs) and usbcore state for the interfaces, so that usbcore
1390 * must usb_set_configuration() before any interfaces could be used.
1391 */
1392void usb_disable_device(struct usb_device *dev, int skip_ep0)
1393{
1394 int i;
1395
1396 /* getting rid of interfaces will disconnect
1397 * any drivers bound to them (a key side effect)
1398 */
1399 if (dev->actconfig) {
1400 /*
1401 * FIXME: In order to avoid self-deadlock involving the
1402 * bandwidth_mutex, we have to mark all the interfaces
1403 * before unregistering any of them.
1404 */
1405 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++)
1406 dev->actconfig->interface[i]->unregistering = 1;
1407
1408 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1409 struct usb_interface *interface;
1410
1411 /* remove this interface if it has been registered */
1412 interface = dev->actconfig->interface[i];
1413 if (!device_is_registered(dev: &interface->dev))
1414 continue;
1415 dev_dbg(&dev->dev, "unregistering interface %s\n",
1416 dev_name(&interface->dev));
1417 remove_intf_ep_devs(intf: interface);
1418 device_del(dev: &interface->dev);
1419 }
1420
1421 /* Now that the interfaces are unbound, nobody should
1422 * try to access them.
1423 */
1424 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1425 put_device(dev: &dev->actconfig->interface[i]->dev);
1426 dev->actconfig->interface[i] = NULL;
1427 }
1428
1429 usb_disable_usb2_hardware_lpm(udev: dev);
1430 usb_unlocked_disable_lpm(udev: dev);
1431 usb_disable_ltm(udev: dev);
1432
1433 dev->actconfig = NULL;
1434 if (dev->state == USB_STATE_CONFIGURED)
1435 usb_set_device_state(udev: dev, new_state: USB_STATE_ADDRESS);
1436 }
1437
1438 dev_dbg(&dev->dev, "%s nuking %s URBs\n", __func__,
1439 skip_ep0 ? "non-ep0" : "all");
1440
1441 usb_disable_device_endpoints(dev, skip_ep0);
1442}
1443
1444/**
1445 * usb_enable_endpoint - Enable an endpoint for USB communications
1446 * @dev: the device whose interface is being enabled
1447 * @ep: the endpoint
1448 * @reset_ep: flag to reset the endpoint state
1449 *
1450 * Resets the endpoint state if asked, and sets dev->ep_{in,out} pointers.
1451 * For control endpoints, both the input and output sides are handled.
1452 */
1453void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep,
1454 bool reset_ep)
1455{
1456 int epnum = usb_endpoint_num(epd: &ep->desc);
1457 int is_out = usb_endpoint_dir_out(epd: &ep->desc);
1458 int is_control = usb_endpoint_xfer_control(epd: &ep->desc);
1459
1460 if (reset_ep)
1461 usb_hcd_reset_endpoint(udev: dev, ep);
1462 if (is_out || is_control)
1463 dev->ep_out[epnum] = ep;
1464 if (!is_out || is_control)
1465 dev->ep_in[epnum] = ep;
1466 ep->enabled = 1;
1467}
1468
1469/**
1470 * usb_enable_interface - Enable all the endpoints for an interface
1471 * @dev: the device whose interface is being enabled
1472 * @intf: pointer to the interface descriptor
1473 * @reset_eps: flag to reset the endpoints' state
1474 *
1475 * Enables all the endpoints for the interface's current altsetting.
1476 */
1477void usb_enable_interface(struct usb_device *dev,
1478 struct usb_interface *intf, bool reset_eps)
1479{
1480 struct usb_host_interface *alt = intf->cur_altsetting;
1481 int i;
1482
1483 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1484 usb_enable_endpoint(dev, ep: &alt->endpoint[i], reset_ep: reset_eps);
1485}
1486
1487/**
1488 * usb_set_interface - Makes a particular alternate setting be current
1489 * @dev: the device whose interface is being updated
1490 * @interface: the interface being updated
1491 * @alternate: the setting being chosen.
1492 *
1493 * Context: task context, might sleep.
1494 *
1495 * This is used to enable data transfers on interfaces that may not
1496 * be enabled by default. Not all devices support such configurability.
1497 * Only the driver bound to an interface may change its setting.
1498 *
1499 * Within any given configuration, each interface may have several
1500 * alternative settings. These are often used to control levels of
1501 * bandwidth consumption. For example, the default setting for a high
1502 * speed interrupt endpoint may not send more than 64 bytes per microframe,
1503 * while interrupt transfers of up to 3KBytes per microframe are legal.
1504 * Also, isochronous endpoints may never be part of an
1505 * interface's default setting. To access such bandwidth, alternate
1506 * interface settings must be made current.
1507 *
1508 * Note that in the Linux USB subsystem, bandwidth associated with
1509 * an endpoint in a given alternate setting is not reserved until an URB
1510 * is submitted that needs that bandwidth. Some other operating systems
1511 * allocate bandwidth early, when a configuration is chosen.
1512 *
1513 * xHCI reserves bandwidth and configures the alternate setting in
1514 * usb_hcd_alloc_bandwidth(). If it fails the original interface altsetting
1515 * may be disabled. Drivers cannot rely on any particular alternate
1516 * setting being in effect after a failure.
1517 *
1518 * This call is synchronous, and may not be used in an interrupt context.
1519 * Also, drivers must not change altsettings while urbs are scheduled for
1520 * endpoints in that interface; all such urbs must first be completed
1521 * (perhaps forced by unlinking). If a thread in your driver uses this call,
1522 * make sure your disconnect() method can wait for it to complete.
1523 *
1524 * Return: Zero on success, or else the status code returned by the
1525 * underlying usb_control_msg() call.
1526 */
1527int usb_set_interface(struct usb_device *dev, int interface, int alternate)
1528{
1529 struct usb_interface *iface;
1530 struct usb_host_interface *alt;
1531 struct usb_hcd *hcd = bus_to_hcd(bus: dev->bus);
1532 int i, ret, manual = 0;
1533 unsigned int epaddr;
1534 unsigned int pipe;
1535
1536 if (dev->state == USB_STATE_SUSPENDED)
1537 return -EHOSTUNREACH;
1538
1539 iface = usb_ifnum_to_if(dev, ifnum: interface);
1540 if (!iface) {
1541 dev_dbg(&dev->dev, "selecting invalid interface %d\n",
1542 interface);
1543 return -EINVAL;
1544 }
1545 if (iface->unregistering)
1546 return -ENODEV;
1547
1548 alt = usb_altnum_to_altsetting(intf: iface, altnum: alternate);
1549 if (!alt) {
1550 dev_warn(&dev->dev, "selecting invalid altsetting %d\n",
1551 alternate);
1552 return -EINVAL;
1553 }
1554 /*
1555 * usb3 hosts configure the interface in usb_hcd_alloc_bandwidth,
1556 * including freeing dropped endpoint ring buffers.
1557 * Make sure the interface endpoints are flushed before that
1558 */
1559 usb_disable_interface(dev, intf: iface, reset_hardware: false);
1560
1561 /* Make sure we have enough bandwidth for this alternate interface.
1562 * Remove the current alt setting and add the new alt setting.
1563 */
1564 mutex_lock(lock: hcd->bandwidth_mutex);
1565 /* Disable LPM, and re-enable it once the new alt setting is installed,
1566 * so that the xHCI driver can recalculate the U1/U2 timeouts.
1567 */
1568 if (usb_disable_lpm(udev: dev)) {
1569 dev_err(&iface->dev, "%s Failed to disable LPM\n", __func__);
1570 mutex_unlock(lock: hcd->bandwidth_mutex);
1571 return -ENOMEM;
1572 }
1573 /* Changing alt-setting also frees any allocated streams */
1574 for (i = 0; i < iface->cur_altsetting->desc.bNumEndpoints; i++)
1575 iface->cur_altsetting->endpoint[i].streams = 0;
1576
1577 ret = usb_hcd_alloc_bandwidth(udev: dev, NULL, old_alt: iface->cur_altsetting, new_alt: alt);
1578 if (ret < 0) {
1579 dev_info(&dev->dev, "Not enough bandwidth for altsetting %d\n",
1580 alternate);
1581 usb_enable_lpm(udev: dev);
1582 mutex_unlock(lock: hcd->bandwidth_mutex);
1583 return ret;
1584 }
1585
1586 if (dev->quirks & USB_QUIRK_NO_SET_INTF)
1587 ret = -EPIPE;
1588 else
1589 ret = usb_control_msg_send(dev, 0,
1590 USB_REQ_SET_INTERFACE,
1591 USB_RECIP_INTERFACE, alternate,
1592 interface, NULL, 0, 5000,
1593 GFP_NOIO);
1594
1595 /* 9.4.10 says devices don't need this and are free to STALL the
1596 * request if the interface only has one alternate setting.
1597 */
1598 if (ret == -EPIPE && iface->num_altsetting == 1) {
1599 dev_dbg(&dev->dev,
1600 "manual set_interface for iface %d, alt %d\n",
1601 interface, alternate);
1602 manual = 1;
1603 } else if (ret) {
1604 /* Re-instate the old alt setting */
1605 usb_hcd_alloc_bandwidth(udev: dev, NULL, old_alt: alt, new_alt: iface->cur_altsetting);
1606 usb_enable_lpm(udev: dev);
1607 mutex_unlock(lock: hcd->bandwidth_mutex);
1608 return ret;
1609 }
1610 mutex_unlock(lock: hcd->bandwidth_mutex);
1611
1612 /* FIXME drivers shouldn't need to replicate/bugfix the logic here
1613 * when they implement async or easily-killable versions of this or
1614 * other "should-be-internal" functions (like clear_halt).
1615 * should hcd+usbcore postprocess control requests?
1616 */
1617
1618 /* prevent submissions using previous endpoint settings */
1619 if (iface->cur_altsetting != alt) {
1620 remove_intf_ep_devs(intf: iface);
1621 usb_remove_sysfs_intf_files(intf: iface);
1622 }
1623 usb_disable_interface(dev, intf: iface, reset_hardware: true);
1624
1625 iface->cur_altsetting = alt;
1626
1627 /* Now that the interface is installed, re-enable LPM. */
1628 usb_unlocked_enable_lpm(udev: dev);
1629
1630 /* If the interface only has one altsetting and the device didn't
1631 * accept the request, we attempt to carry out the equivalent action
1632 * by manually clearing the HALT feature for each endpoint in the
1633 * new altsetting.
1634 */
1635 if (manual) {
1636 for (i = 0; i < alt->desc.bNumEndpoints; i++) {
1637 epaddr = alt->endpoint[i].desc.bEndpointAddress;
1638 pipe = __create_pipe(dev,
1639 USB_ENDPOINT_NUMBER_MASK & epaddr) |
1640 (usb_endpoint_out(epaddr) ?
1641 USB_DIR_OUT : USB_DIR_IN);
1642
1643 usb_clear_halt(dev, pipe);
1644 }
1645 }
1646
1647 /* 9.1.1.5: reset toggles for all endpoints in the new altsetting
1648 *
1649 * Note:
1650 * Despite EP0 is always present in all interfaces/AS, the list of
1651 * endpoints from the descriptor does not contain EP0. Due to its
1652 * omnipresence one might expect EP0 being considered "affected" by
1653 * any SetInterface request and hence assume toggles need to be reset.
1654 * However, EP0 toggles are re-synced for every individual transfer
1655 * during the SETUP stage - hence EP0 toggles are "don't care" here.
1656 * (Likewise, EP0 never "halts" on well designed devices.)
1657 */
1658 usb_enable_interface(dev, intf: iface, reset_eps: true);
1659 if (device_is_registered(dev: &iface->dev)) {
1660 usb_create_sysfs_intf_files(intf: iface);
1661 create_intf_ep_devs(intf: iface);
1662 }
1663 return 0;
1664}
1665EXPORT_SYMBOL_GPL(usb_set_interface);
1666
1667/**
1668 * usb_reset_configuration - lightweight device reset
1669 * @dev: the device whose configuration is being reset
1670 *
1671 * This issues a standard SET_CONFIGURATION request to the device using
1672 * the current configuration. The effect is to reset most USB-related
1673 * state in the device, including interface altsettings (reset to zero),
1674 * endpoint halts (cleared), and endpoint state (only for bulk and interrupt
1675 * endpoints). Other usbcore state is unchanged, including bindings of
1676 * usb device drivers to interfaces.
1677 *
1678 * Because this affects multiple interfaces, avoid using this with composite
1679 * (multi-interface) devices. Instead, the driver for each interface may
1680 * use usb_set_interface() on the interfaces it claims. Be careful though;
1681 * some devices don't support the SET_INTERFACE request, and others won't
1682 * reset all the interface state (notably endpoint state). Resetting the whole
1683 * configuration would affect other drivers' interfaces.
1684 *
1685 * The caller must own the device lock.
1686 *
1687 * Return: Zero on success, else a negative error code.
1688 *
1689 * If this routine fails the device will probably be in an unusable state
1690 * with endpoints disabled, and interfaces only partially enabled.
1691 */
1692int usb_reset_configuration(struct usb_device *dev)
1693{
1694 int i, retval;
1695 struct usb_host_config *config;
1696 struct usb_hcd *hcd = bus_to_hcd(bus: dev->bus);
1697
1698 if (dev->state == USB_STATE_SUSPENDED)
1699 return -EHOSTUNREACH;
1700
1701 /* caller must have locked the device and must own
1702 * the usb bus readlock (so driver bindings are stable);
1703 * calls during probe() are fine
1704 */
1705
1706 usb_disable_device_endpoints(dev, skip_ep0: 1); /* skip ep0*/
1707
1708 config = dev->actconfig;
1709 retval = 0;
1710 mutex_lock(lock: hcd->bandwidth_mutex);
1711 /* Disable LPM, and re-enable it once the configuration is reset, so
1712 * that the xHCI driver can recalculate the U1/U2 timeouts.
1713 */
1714 if (usb_disable_lpm(udev: dev)) {
1715 dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
1716 mutex_unlock(lock: hcd->bandwidth_mutex);
1717 return -ENOMEM;
1718 }
1719
1720 /* xHCI adds all endpoints in usb_hcd_alloc_bandwidth */
1721 retval = usb_hcd_alloc_bandwidth(udev: dev, new_config: config, NULL, NULL);
1722 if (retval < 0) {
1723 usb_enable_lpm(udev: dev);
1724 mutex_unlock(lock: hcd->bandwidth_mutex);
1725 return retval;
1726 }
1727 retval = usb_control_msg_send(dev, 0, USB_REQ_SET_CONFIGURATION, 0,
1728 config->desc.bConfigurationValue, 0,
1729 NULL, 0, USB_CTRL_SET_TIMEOUT,
1730 GFP_NOIO);
1731 if (retval) {
1732 usb_hcd_alloc_bandwidth(udev: dev, NULL, NULL, NULL);
1733 usb_enable_lpm(udev: dev);
1734 mutex_unlock(lock: hcd->bandwidth_mutex);
1735 return retval;
1736 }
1737 mutex_unlock(lock: hcd->bandwidth_mutex);
1738
1739 /* re-init hc/hcd interface/endpoint state */
1740 for (i = 0; i < config->desc.bNumInterfaces; i++) {
1741 struct usb_interface *intf = config->interface[i];
1742 struct usb_host_interface *alt;
1743
1744 alt = usb_altnum_to_altsetting(intf, altnum: 0);
1745
1746 /* No altsetting 0? We'll assume the first altsetting.
1747 * We could use a GetInterface call, but if a device is
1748 * so non-compliant that it doesn't have altsetting 0
1749 * then I wouldn't trust its reply anyway.
1750 */
1751 if (!alt)
1752 alt = &intf->altsetting[0];
1753
1754 if (alt != intf->cur_altsetting) {
1755 remove_intf_ep_devs(intf);
1756 usb_remove_sysfs_intf_files(intf);
1757 }
1758 intf->cur_altsetting = alt;
1759 usb_enable_interface(dev, intf, reset_eps: true);
1760 if (device_is_registered(dev: &intf->dev)) {
1761 usb_create_sysfs_intf_files(intf);
1762 create_intf_ep_devs(intf);
1763 }
1764 }
1765 /* Now that the interfaces are installed, re-enable LPM. */
1766 usb_unlocked_enable_lpm(udev: dev);
1767 return 0;
1768}
1769EXPORT_SYMBOL_GPL(usb_reset_configuration);
1770
1771static void usb_release_interface(struct device *dev)
1772{
1773 struct usb_interface *intf = to_usb_interface(dev);
1774 struct usb_interface_cache *intfc =
1775 altsetting_to_usb_interface_cache(intf->altsetting);
1776
1777 kref_put(kref: &intfc->ref, release: usb_release_interface_cache);
1778 usb_put_dev(interface_to_usbdev(intf));
1779 of_node_put(node: dev->of_node);
1780 kfree(objp: intf);
1781}
1782
1783/*
1784 * usb_deauthorize_interface - deauthorize an USB interface
1785 *
1786 * @intf: USB interface structure
1787 */
1788void usb_deauthorize_interface(struct usb_interface *intf)
1789{
1790 struct device *dev = &intf->dev;
1791
1792 device_lock(dev: dev->parent);
1793
1794 if (intf->authorized) {
1795 device_lock(dev);
1796 intf->authorized = 0;
1797 device_unlock(dev);
1798
1799 usb_forced_unbind_intf(intf);
1800 }
1801
1802 device_unlock(dev: dev->parent);
1803}
1804
1805/*
1806 * usb_authorize_interface - authorize an USB interface
1807 *
1808 * @intf: USB interface structure
1809 */
1810void usb_authorize_interface(struct usb_interface *intf)
1811{
1812 struct device *dev = &intf->dev;
1813
1814 if (!intf->authorized) {
1815 device_lock(dev);
1816 intf->authorized = 1; /* authorize interface */
1817 device_unlock(dev);
1818 }
1819}
1820
1821static int usb_if_uevent(const struct device *dev, struct kobj_uevent_env *env)
1822{
1823 const struct usb_device *usb_dev;
1824 const struct usb_interface *intf;
1825 const struct usb_host_interface *alt;
1826
1827 intf = to_usb_interface(dev);
1828 usb_dev = interface_to_usbdev(intf);
1829 alt = intf->cur_altsetting;
1830
1831 if (add_uevent_var(env, format: "INTERFACE=%d/%d/%d",
1832 alt->desc.bInterfaceClass,
1833 alt->desc.bInterfaceSubClass,
1834 alt->desc.bInterfaceProtocol))
1835 return -ENOMEM;
1836
1837 if (add_uevent_var(env,
1838 format: "MODALIAS=usb:"
1839 "v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02Xin%02X",
1840 le16_to_cpu(usb_dev->descriptor.idVendor),
1841 le16_to_cpu(usb_dev->descriptor.idProduct),
1842 le16_to_cpu(usb_dev->descriptor.bcdDevice),
1843 usb_dev->descriptor.bDeviceClass,
1844 usb_dev->descriptor.bDeviceSubClass,
1845 usb_dev->descriptor.bDeviceProtocol,
1846 alt->desc.bInterfaceClass,
1847 alt->desc.bInterfaceSubClass,
1848 alt->desc.bInterfaceProtocol,
1849 alt->desc.bInterfaceNumber))
1850 return -ENOMEM;
1851
1852 return 0;
1853}
1854
1855const struct device_type usb_if_device_type = {
1856 .name = "usb_interface",
1857 .release = usb_release_interface,
1858 .uevent = usb_if_uevent,
1859};
1860
1861static struct usb_interface_assoc_descriptor *find_iad(struct usb_device *dev,
1862 struct usb_host_config *config,
1863 u8 inum)
1864{
1865 struct usb_interface_assoc_descriptor *retval = NULL;
1866 struct usb_interface_assoc_descriptor *intf_assoc;
1867 int first_intf;
1868 int last_intf;
1869 int i;
1870
1871 for (i = 0; (i < USB_MAXIADS && config->intf_assoc[i]); i++) {
1872 intf_assoc = config->intf_assoc[i];
1873 if (intf_assoc->bInterfaceCount == 0)
1874 continue;
1875
1876 first_intf = intf_assoc->bFirstInterface;
1877 last_intf = first_intf + (intf_assoc->bInterfaceCount - 1);
1878 if (inum >= first_intf && inum <= last_intf) {
1879 if (!retval)
1880 retval = intf_assoc;
1881 else
1882 dev_err(&dev->dev, "Interface #%d referenced"
1883 " by multiple IADs\n", inum);
1884 }
1885 }
1886
1887 return retval;
1888}
1889
1890
1891/*
1892 * Internal function to queue a device reset
1893 * See usb_queue_reset_device() for more details
1894 */
1895static void __usb_queue_reset_device(struct work_struct *ws)
1896{
1897 int rc;
1898 struct usb_interface *iface =
1899 container_of(ws, struct usb_interface, reset_ws);
1900 struct usb_device *udev = interface_to_usbdev(iface);
1901
1902 rc = usb_lock_device_for_reset(udev, iface);
1903 if (rc >= 0) {
1904 usb_reset_device(dev: udev);
1905 usb_unlock_device(udev);
1906 }
1907 usb_put_intf(intf: iface); /* Undo _get_ in usb_queue_reset_device() */
1908}
1909
1910/*
1911 * Internal function to set the wireless_status sysfs attribute
1912 * See usb_set_wireless_status() for more details
1913 */
1914static void __usb_wireless_status_intf(struct work_struct *ws)
1915{
1916 struct usb_interface *iface =
1917 container_of(ws, struct usb_interface, wireless_status_work);
1918
1919 device_lock(dev: iface->dev.parent);
1920 if (iface->sysfs_files_created)
1921 usb_update_wireless_status_attr(intf: iface);
1922 device_unlock(dev: iface->dev.parent);
1923 usb_put_intf(intf: iface); /* Undo _get_ in usb_set_wireless_status() */
1924}
1925
1926/**
1927 * usb_set_wireless_status - sets the wireless_status struct member
1928 * @iface: the interface to modify
1929 * @status: the new wireless status
1930 *
1931 * Set the wireless_status struct member to the new value, and emit
1932 * sysfs changes as necessary.
1933 *
1934 * Returns: 0 on success, -EALREADY if already set.
1935 */
1936int usb_set_wireless_status(struct usb_interface *iface,
1937 enum usb_wireless_status status)
1938{
1939 if (iface->wireless_status == status)
1940 return -EALREADY;
1941
1942 usb_get_intf(intf: iface);
1943 iface->wireless_status = status;
1944 schedule_work(work: &iface->wireless_status_work);
1945
1946 return 0;
1947}
1948EXPORT_SYMBOL_GPL(usb_set_wireless_status);
1949
1950/*
1951 * usb_set_configuration - Makes a particular device setting be current
1952 * @dev: the device whose configuration is being updated
1953 * @configuration: the configuration being chosen.
1954 *
1955 * Context: task context, might sleep. Caller holds device lock.
1956 *
1957 * This is used to enable non-default device modes. Not all devices
1958 * use this kind of configurability; many devices only have one
1959 * configuration.
1960 *
1961 * @configuration is the value of the configuration to be installed.
1962 * According to the USB spec (e.g. section 9.1.1.5), configuration values
1963 * must be non-zero; a value of zero indicates that the device in
1964 * unconfigured. However some devices erroneously use 0 as one of their
1965 * configuration values. To help manage such devices, this routine will
1966 * accept @configuration = -1 as indicating the device should be put in
1967 * an unconfigured state.
1968 *
1969 * USB device configurations may affect Linux interoperability,
1970 * power consumption and the functionality available. For example,
1971 * the default configuration is limited to using 100mA of bus power,
1972 * so that when certain device functionality requires more power,
1973 * and the device is bus powered, that functionality should be in some
1974 * non-default device configuration. Other device modes may also be
1975 * reflected as configuration options, such as whether two ISDN
1976 * channels are available independently; and choosing between open
1977 * standard device protocols (like CDC) or proprietary ones.
1978 *
1979 * Note that a non-authorized device (dev->authorized == 0) will only
1980 * be put in unconfigured mode.
1981 *
1982 * Note that USB has an additional level of device configurability,
1983 * associated with interfaces. That configurability is accessed using
1984 * usb_set_interface().
1985 *
1986 * This call is synchronous. The calling context must be able to sleep,
1987 * must own the device lock, and must not hold the driver model's USB
1988 * bus mutex; usb interface driver probe() methods cannot use this routine.
1989 *
1990 * Returns zero on success, or else the status code returned by the
1991 * underlying call that failed. On successful completion, each interface
1992 * in the original device configuration has been destroyed, and each one
1993 * in the new configuration has been probed by all relevant usb device
1994 * drivers currently known to the kernel.
1995 */
1996int usb_set_configuration(struct usb_device *dev, int configuration)
1997{
1998 int i, ret;
1999 struct usb_host_config *cp = NULL;
2000 struct usb_interface **new_interfaces = NULL;
2001 struct usb_hcd *hcd = bus_to_hcd(bus: dev->bus);
2002 int n, nintf;
2003
2004 if (dev->authorized == 0 || configuration == -1)
2005 configuration = 0;
2006 else {
2007 for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
2008 if (dev->config[i].desc.bConfigurationValue ==
2009 configuration) {
2010 cp = &dev->config[i];
2011 break;
2012 }
2013 }
2014 }
2015 if ((!cp && configuration != 0))
2016 return -EINVAL;
2017
2018 /* The USB spec says configuration 0 means unconfigured.
2019 * But if a device includes a configuration numbered 0,
2020 * we will accept it as a correctly configured state.
2021 * Use -1 if you really want to unconfigure the device.
2022 */
2023 if (cp && configuration == 0)
2024 dev_warn(&dev->dev, "config 0 descriptor??\n");
2025
2026 /* Allocate memory for new interfaces before doing anything else,
2027 * so that if we run out then nothing will have changed. */
2028 n = nintf = 0;
2029 if (cp) {
2030 nintf = cp->desc.bNumInterfaces;
2031 new_interfaces = kmalloc_array(nintf, sizeof(*new_interfaces),
2032 GFP_NOIO);
2033 if (!new_interfaces)
2034 return -ENOMEM;
2035
2036 for (; n < nintf; ++n) {
2037 new_interfaces[n] = kzalloc(
2038 sizeof(struct usb_interface),
2039 GFP_NOIO);
2040 if (!new_interfaces[n]) {
2041 ret = -ENOMEM;
2042free_interfaces:
2043 while (--n >= 0)
2044 kfree(objp: new_interfaces[n]);
2045 kfree(objp: new_interfaces);
2046 return ret;
2047 }
2048 }
2049
2050 i = dev->bus_mA - usb_get_max_power(udev: dev, c: cp);
2051 if (i < 0)
2052 dev_warn(&dev->dev, "new config #%d exceeds power "
2053 "limit by %dmA\n",
2054 configuration, -i);
2055 }
2056
2057 /* Wake up the device so we can send it the Set-Config request */
2058 ret = usb_autoresume_device(udev: dev);
2059 if (ret)
2060 goto free_interfaces;
2061
2062 /* if it's already configured, clear out old state first.
2063 * getting rid of old interfaces means unbinding their drivers.
2064 */
2065 if (dev->state != USB_STATE_ADDRESS)
2066 usb_disable_device(dev, skip_ep0: 1); /* Skip ep0 */
2067
2068 /* Get rid of pending async Set-Config requests for this device */
2069 cancel_async_set_config(udev: dev);
2070
2071 /* Make sure we have bandwidth (and available HCD resources) for this
2072 * configuration. Remove endpoints from the schedule if we're dropping
2073 * this configuration to set configuration 0. After this point, the
2074 * host controller will not allow submissions to dropped endpoints. If
2075 * this call fails, the device state is unchanged.
2076 */
2077 mutex_lock(lock: hcd->bandwidth_mutex);
2078 /* Disable LPM, and re-enable it once the new configuration is
2079 * installed, so that the xHCI driver can recalculate the U1/U2
2080 * timeouts.
2081 */
2082 if (dev->actconfig && usb_disable_lpm(udev: dev)) {
2083 dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
2084 mutex_unlock(lock: hcd->bandwidth_mutex);
2085 ret = -ENOMEM;
2086 goto free_interfaces;
2087 }
2088 ret = usb_hcd_alloc_bandwidth(udev: dev, new_config: cp, NULL, NULL);
2089 if (ret < 0) {
2090 if (dev->actconfig)
2091 usb_enable_lpm(udev: dev);
2092 mutex_unlock(lock: hcd->bandwidth_mutex);
2093 usb_autosuspend_device(udev: dev);
2094 goto free_interfaces;
2095 }
2096
2097 /*
2098 * Initialize the new interface structures and the
2099 * hc/hcd/usbcore interface/endpoint state.
2100 */
2101 for (i = 0; i < nintf; ++i) {
2102 struct usb_interface_cache *intfc;
2103 struct usb_interface *intf;
2104 struct usb_host_interface *alt;
2105 u8 ifnum;
2106
2107 cp->interface[i] = intf = new_interfaces[i];
2108 intfc = cp->intf_cache[i];
2109 intf->altsetting = intfc->altsetting;
2110 intf->num_altsetting = intfc->num_altsetting;
2111 intf->authorized = !!HCD_INTF_AUTHORIZED(hcd);
2112 kref_get(kref: &intfc->ref);
2113
2114 alt = usb_altnum_to_altsetting(intf, altnum: 0);
2115
2116 /* No altsetting 0? We'll assume the first altsetting.
2117 * We could use a GetInterface call, but if a device is
2118 * so non-compliant that it doesn't have altsetting 0
2119 * then I wouldn't trust its reply anyway.
2120 */
2121 if (!alt)
2122 alt = &intf->altsetting[0];
2123
2124 ifnum = alt->desc.bInterfaceNumber;
2125 intf->intf_assoc = find_iad(dev, config: cp, inum: ifnum);
2126 intf->cur_altsetting = alt;
2127 usb_enable_interface(dev, intf, reset_eps: true);
2128 intf->dev.parent = &dev->dev;
2129 if (usb_of_has_combined_node(udev: dev)) {
2130 device_set_of_node_from_dev(dev: &intf->dev, dev2: &dev->dev);
2131 } else {
2132 intf->dev.of_node = usb_of_get_interface_node(udev: dev,
2133 config: configuration, ifnum);
2134 }
2135 ACPI_COMPANION_SET(&intf->dev, ACPI_COMPANION(&dev->dev));
2136 intf->dev.driver = NULL;
2137 intf->dev.bus = &usb_bus_type;
2138 intf->dev.type = &usb_if_device_type;
2139 intf->dev.groups = usb_interface_groups;
2140 INIT_WORK(&intf->reset_ws, __usb_queue_reset_device);
2141 INIT_WORK(&intf->wireless_status_work, __usb_wireless_status_intf);
2142 intf->minor = -1;
2143 device_initialize(dev: &intf->dev);
2144 pm_runtime_no_callbacks(dev: &intf->dev);
2145 dev_set_name(dev: &intf->dev, name: "%d-%s:%d.%d", dev->bus->busnum,
2146 dev->devpath, configuration, ifnum);
2147 usb_get_dev(dev);
2148 }
2149 kfree(objp: new_interfaces);
2150
2151 ret = usb_control_msg_send(dev, 0, USB_REQ_SET_CONFIGURATION, 0,
2152 configuration, 0, NULL, 0,
2153 USB_CTRL_SET_TIMEOUT, GFP_NOIO);
2154 if (ret && cp) {
2155 /*
2156 * All the old state is gone, so what else can we do?
2157 * The device is probably useless now anyway.
2158 */
2159 usb_hcd_alloc_bandwidth(udev: dev, NULL, NULL, NULL);
2160 for (i = 0; i < nintf; ++i) {
2161 usb_disable_interface(dev, intf: cp->interface[i], reset_hardware: true);
2162 put_device(dev: &cp->interface[i]->dev);
2163 cp->interface[i] = NULL;
2164 }
2165 cp = NULL;
2166 }
2167
2168 dev->actconfig = cp;
2169 mutex_unlock(lock: hcd->bandwidth_mutex);
2170
2171 if (!cp) {
2172 usb_set_device_state(udev: dev, new_state: USB_STATE_ADDRESS);
2173
2174 /* Leave LPM disabled while the device is unconfigured. */
2175 usb_autosuspend_device(udev: dev);
2176 return ret;
2177 }
2178 usb_set_device_state(udev: dev, new_state: USB_STATE_CONFIGURED);
2179
2180 if (cp->string == NULL &&
2181 !(dev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
2182 cp->string = usb_cache_string(dev, cp->desc.iConfiguration);
2183
2184 /* Now that the interfaces are installed, re-enable LPM. */
2185 usb_unlocked_enable_lpm(udev: dev);
2186 /* Enable LTM if it was turned off by usb_disable_device. */
2187 usb_enable_ltm(udev: dev);
2188
2189 /* Now that all the interfaces are set up, register them
2190 * to trigger binding of drivers to interfaces. probe()
2191 * routines may install different altsettings and may
2192 * claim() any interfaces not yet bound. Many class drivers
2193 * need that: CDC, audio, video, etc.
2194 */
2195 for (i = 0; i < nintf; ++i) {
2196 struct usb_interface *intf = cp->interface[i];
2197
2198 if (intf->dev.of_node &&
2199 !of_device_is_available(device: intf->dev.of_node)) {
2200 dev_info(&dev->dev, "skipping disabled interface %d\n",
2201 intf->cur_altsetting->desc.bInterfaceNumber);
2202 continue;
2203 }
2204
2205 dev_dbg(&dev->dev,
2206 "adding %s (config #%d, interface %d)\n",
2207 dev_name(&intf->dev), configuration,
2208 intf->cur_altsetting->desc.bInterfaceNumber);
2209 device_enable_async_suspend(dev: &intf->dev);
2210 ret = device_add(dev: &intf->dev);
2211 if (ret != 0) {
2212 dev_err(&dev->dev, "device_add(%s) --> %d\n",
2213 dev_name(&intf->dev), ret);
2214 continue;
2215 }
2216 create_intf_ep_devs(intf);
2217 }
2218
2219 usb_autosuspend_device(udev: dev);
2220 return 0;
2221}
2222EXPORT_SYMBOL_GPL(usb_set_configuration);
2223
2224static LIST_HEAD(set_config_list);
2225static DEFINE_SPINLOCK(set_config_lock);
2226
2227struct set_config_request {
2228 struct usb_device *udev;
2229 int config;
2230 struct work_struct work;
2231 struct list_head node;
2232};
2233
2234/* Worker routine for usb_driver_set_configuration() */
2235static void driver_set_config_work(struct work_struct *work)
2236{
2237 struct set_config_request *req =
2238 container_of(work, struct set_config_request, work);
2239 struct usb_device *udev = req->udev;
2240
2241 usb_lock_device(udev);
2242 spin_lock(lock: &set_config_lock);
2243 list_del(entry: &req->node);
2244 spin_unlock(lock: &set_config_lock);
2245
2246 if (req->config >= -1) /* Is req still valid? */
2247 usb_set_configuration(udev, req->config);
2248 usb_unlock_device(udev);
2249 usb_put_dev(dev: udev);
2250 kfree(objp: req);
2251}
2252
2253/* Cancel pending Set-Config requests for a device whose configuration
2254 * was just changed
2255 */
2256static void cancel_async_set_config(struct usb_device *udev)
2257{
2258 struct set_config_request *req;
2259
2260 spin_lock(lock: &set_config_lock);
2261 list_for_each_entry(req, &set_config_list, node) {
2262 if (req->udev == udev)
2263 req->config = -999; /* Mark as cancelled */
2264 }
2265 spin_unlock(lock: &set_config_lock);
2266}
2267
2268/**
2269 * usb_driver_set_configuration - Provide a way for drivers to change device configurations
2270 * @udev: the device whose configuration is being updated
2271 * @config: the configuration being chosen.
2272 * Context: In process context, must be able to sleep
2273 *
2274 * Device interface drivers are not allowed to change device configurations.
2275 * This is because changing configurations will destroy the interface the
2276 * driver is bound to and create new ones; it would be like a floppy-disk
2277 * driver telling the computer to replace the floppy-disk drive with a
2278 * tape drive!
2279 *
2280 * Still, in certain specialized circumstances the need may arise. This
2281 * routine gets around the normal restrictions by using a work thread to
2282 * submit the change-config request.
2283 *
2284 * Return: 0 if the request was successfully queued, error code otherwise.
2285 * The caller has no way to know whether the queued request will eventually
2286 * succeed.
2287 */
2288int usb_driver_set_configuration(struct usb_device *udev, int config)
2289{
2290 struct set_config_request *req;
2291
2292 req = kmalloc(sizeof(*req), GFP_KERNEL);
2293 if (!req)
2294 return -ENOMEM;
2295 req->udev = udev;
2296 req->config = config;
2297 INIT_WORK(&req->work, driver_set_config_work);
2298
2299 spin_lock(lock: &set_config_lock);
2300 list_add(new: &req->node, head: &set_config_list);
2301 spin_unlock(lock: &set_config_lock);
2302
2303 usb_get_dev(dev: udev);
2304 schedule_work(work: &req->work);
2305 return 0;
2306}
2307EXPORT_SYMBOL_GPL(usb_driver_set_configuration);
2308
2309/**
2310 * cdc_parse_cdc_header - parse the extra headers present in CDC devices
2311 * @hdr: the place to put the results of the parsing
2312 * @intf: the interface for which parsing is requested
2313 * @buffer: pointer to the extra headers to be parsed
2314 * @buflen: length of the extra headers
2315 *
2316 * This evaluates the extra headers present in CDC devices which
2317 * bind the interfaces for data and control and provide details
2318 * about the capabilities of the device.
2319 *
2320 * Return: number of descriptors parsed or -EINVAL
2321 * if the header is contradictory beyond salvage
2322 */
2323
2324int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr,
2325 struct usb_interface *intf,
2326 u8 *buffer,
2327 int buflen)
2328{
2329 /* duplicates are ignored */
2330 struct usb_cdc_union_desc *union_header = NULL;
2331
2332 /* duplicates are not tolerated */
2333 struct usb_cdc_header_desc *header = NULL;
2334 struct usb_cdc_ether_desc *ether = NULL;
2335 struct usb_cdc_mdlm_detail_desc *detail = NULL;
2336 struct usb_cdc_mdlm_desc *desc = NULL;
2337
2338 unsigned int elength;
2339 int cnt = 0;
2340
2341 memset(s: hdr, c: 0x00, n: sizeof(struct usb_cdc_parsed_header));
2342 hdr->phonet_magic_present = false;
2343 while (buflen > 0) {
2344 elength = buffer[0];
2345 if (!elength) {
2346 dev_err(&intf->dev, "skipping garbage byte\n");
2347 elength = 1;
2348 goto next_desc;
2349 }
2350 if ((buflen < elength) || (elength < 3)) {
2351 dev_err(&intf->dev, "invalid descriptor buffer length\n");
2352 break;
2353 }
2354 if (buffer[1] != USB_DT_CS_INTERFACE) {
2355 dev_err(&intf->dev, "skipping garbage\n");
2356 goto next_desc;
2357 }
2358
2359 switch (buffer[2]) {
2360 case USB_CDC_UNION_TYPE: /* we've found it */
2361 if (elength < sizeof(struct usb_cdc_union_desc))
2362 goto next_desc;
2363 if (union_header) {
2364 dev_err(&intf->dev, "More than one union descriptor, skipping ...\n");
2365 goto next_desc;
2366 }
2367 union_header = (struct usb_cdc_union_desc *)buffer;
2368 break;
2369 case USB_CDC_COUNTRY_TYPE:
2370 if (elength < sizeof(struct usb_cdc_country_functional_desc))
2371 goto next_desc;
2372 hdr->usb_cdc_country_functional_desc =
2373 (struct usb_cdc_country_functional_desc *)buffer;
2374 break;
2375 case USB_CDC_HEADER_TYPE:
2376 if (elength != sizeof(struct usb_cdc_header_desc))
2377 goto next_desc;
2378 if (header)
2379 return -EINVAL;
2380 header = (struct usb_cdc_header_desc *)buffer;
2381 break;
2382 case USB_CDC_ACM_TYPE:
2383 if (elength < sizeof(struct usb_cdc_acm_descriptor))
2384 goto next_desc;
2385 hdr->usb_cdc_acm_descriptor =
2386 (struct usb_cdc_acm_descriptor *)buffer;
2387 break;
2388 case USB_CDC_ETHERNET_TYPE:
2389 if (elength != sizeof(struct usb_cdc_ether_desc))
2390 goto next_desc;
2391 if (ether)
2392 return -EINVAL;
2393 ether = (struct usb_cdc_ether_desc *)buffer;
2394 break;
2395 case USB_CDC_CALL_MANAGEMENT_TYPE:
2396 if (elength < sizeof(struct usb_cdc_call_mgmt_descriptor))
2397 goto next_desc;
2398 hdr->usb_cdc_call_mgmt_descriptor =
2399 (struct usb_cdc_call_mgmt_descriptor *)buffer;
2400 break;
2401 case USB_CDC_DMM_TYPE:
2402 if (elength < sizeof(struct usb_cdc_dmm_desc))
2403 goto next_desc;
2404 hdr->usb_cdc_dmm_desc =
2405 (struct usb_cdc_dmm_desc *)buffer;
2406 break;
2407 case USB_CDC_MDLM_TYPE:
2408 if (elength < sizeof(struct usb_cdc_mdlm_desc))
2409 goto next_desc;
2410 if (desc)
2411 return -EINVAL;
2412 desc = (struct usb_cdc_mdlm_desc *)buffer;
2413 break;
2414 case USB_CDC_MDLM_DETAIL_TYPE:
2415 if (elength < sizeof(struct usb_cdc_mdlm_detail_desc))
2416 goto next_desc;
2417 if (detail)
2418 return -EINVAL;
2419 detail = (struct usb_cdc_mdlm_detail_desc *)buffer;
2420 break;
2421 case USB_CDC_NCM_TYPE:
2422 if (elength < sizeof(struct usb_cdc_ncm_desc))
2423 goto next_desc;
2424 hdr->usb_cdc_ncm_desc = (struct usb_cdc_ncm_desc *)buffer;
2425 break;
2426 case USB_CDC_MBIM_TYPE:
2427 if (elength < sizeof(struct usb_cdc_mbim_desc))
2428 goto next_desc;
2429
2430 hdr->usb_cdc_mbim_desc = (struct usb_cdc_mbim_desc *)buffer;
2431 break;
2432 case USB_CDC_MBIM_EXTENDED_TYPE:
2433 if (elength < sizeof(struct usb_cdc_mbim_extended_desc))
2434 break;
2435 hdr->usb_cdc_mbim_extended_desc =
2436 (struct usb_cdc_mbim_extended_desc *)buffer;
2437 break;
2438 case CDC_PHONET_MAGIC_NUMBER:
2439 hdr->phonet_magic_present = true;
2440 break;
2441 default:
2442 /*
2443 * there are LOTS more CDC descriptors that
2444 * could legitimately be found here.
2445 */
2446 dev_dbg(&intf->dev, "Ignoring descriptor: type %02x, length %ud\n",
2447 buffer[2], elength);
2448 goto next_desc;
2449 }
2450 cnt++;
2451next_desc:
2452 buflen -= elength;
2453 buffer += elength;
2454 }
2455 hdr->usb_cdc_union_desc = union_header;
2456 hdr->usb_cdc_header_desc = header;
2457 hdr->usb_cdc_mdlm_detail_desc = detail;
2458 hdr->usb_cdc_mdlm_desc = desc;
2459 hdr->usb_cdc_ether_desc = ether;
2460 return cnt;
2461}
2462
2463EXPORT_SYMBOL(cdc_parse_cdc_header);
2464