xref: /openbmc/linux/drivers/usb/storage/uas.c (revision 59b4412f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * USB Attached SCSI
4  * Note that this is not the same as the USB Mass Storage driver
5  *
6  * Copyright Hans de Goede <hdegoede@redhat.com> for Red Hat, Inc. 2013 - 2016
7  * Copyright Matthew Wilcox for Intel Corp, 2010
8  * Copyright Sarah Sharp for Intel Corp, 2010
9  */
10 
11 #include <linux/blkdev.h>
12 #include <linux/slab.h>
13 #include <linux/types.h>
14 #include <linux/module.h>
15 #include <linux/usb.h>
16 #include <linux/usb_usual.h>
17 #include <linux/usb/hcd.h>
18 #include <linux/usb/storage.h>
19 #include <linux/usb/uas.h>
20 
21 #include <scsi/scsi.h>
22 #include <scsi/scsi_eh.h>
23 #include <scsi/scsi_dbg.h>
24 #include <scsi/scsi_cmnd.h>
25 #include <scsi/scsi_device.h>
26 #include <scsi/scsi_host.h>
27 #include <scsi/scsi_tcq.h>
28 
29 #include "uas-detect.h"
30 #include "scsiglue.h"
31 
32 #define MAX_CMNDS 256
33 
34 struct uas_dev_info {
35 	struct usb_interface *intf;
36 	struct usb_device *udev;
37 	struct usb_anchor cmd_urbs;
38 	struct usb_anchor sense_urbs;
39 	struct usb_anchor data_urbs;
40 	unsigned long flags;
41 	int qdepth, resetting;
42 	unsigned cmd_pipe, status_pipe, data_in_pipe, data_out_pipe;
43 	unsigned use_streams:1;
44 	unsigned shutdown:1;
45 	struct scsi_cmnd *cmnd[MAX_CMNDS];
46 	spinlock_t lock;
47 	struct work_struct work;
48 	struct work_struct scan_work;      /* for async scanning */
49 };
50 
51 enum {
52 	SUBMIT_STATUS_URB	= BIT(1),
53 	ALLOC_DATA_IN_URB	= BIT(2),
54 	SUBMIT_DATA_IN_URB	= BIT(3),
55 	ALLOC_DATA_OUT_URB	= BIT(4),
56 	SUBMIT_DATA_OUT_URB	= BIT(5),
57 	ALLOC_CMD_URB		= BIT(6),
58 	SUBMIT_CMD_URB		= BIT(7),
59 	COMMAND_INFLIGHT        = BIT(8),
60 	DATA_IN_URB_INFLIGHT    = BIT(9),
61 	DATA_OUT_URB_INFLIGHT   = BIT(10),
62 	COMMAND_ABORTED         = BIT(11),
63 	IS_IN_WORK_LIST         = BIT(12),
64 };
65 
66 /* Overrides scsi_pointer */
67 struct uas_cmd_info {
68 	unsigned int state;
69 	unsigned int uas_tag;
70 	struct urb *cmd_urb;
71 	struct urb *data_in_urb;
72 	struct urb *data_out_urb;
73 };
74 
75 /* I hate forward declarations, but I actually have a loop */
76 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
77 				struct uas_dev_info *devinfo);
78 static void uas_do_work(struct work_struct *work);
79 static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller);
80 static void uas_free_streams(struct uas_dev_info *devinfo);
81 static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *prefix,
82 				int status);
83 
84 /*
85  * This driver needs its own workqueue, as we need to control memory allocation.
86  *
87  * In the course of error handling and power management uas_wait_for_pending_cmnds()
88  * needs to flush pending work items. In these contexts we cannot allocate memory
89  * by doing block IO as we would deadlock. For the same reason we cannot wait
90  * for anything allocating memory not heeding these constraints.
91  *
92  * So we have to control all work items that can be on the workqueue we flush.
93  * Hence we cannot share a queue and need our own.
94  */
95 static struct workqueue_struct *workqueue;
96 
97 static void uas_do_work(struct work_struct *work)
98 {
99 	struct uas_dev_info *devinfo =
100 		container_of(work, struct uas_dev_info, work);
101 	struct uas_cmd_info *cmdinfo;
102 	struct scsi_cmnd *cmnd;
103 	unsigned long flags;
104 	int i, err;
105 
106 	spin_lock_irqsave(&devinfo->lock, flags);
107 
108 	if (devinfo->resetting)
109 		goto out;
110 
111 	for (i = 0; i < devinfo->qdepth; i++) {
112 		if (!devinfo->cmnd[i])
113 			continue;
114 
115 		cmnd = devinfo->cmnd[i];
116 		cmdinfo = (void *)&cmnd->SCp;
117 
118 		if (!(cmdinfo->state & IS_IN_WORK_LIST))
119 			continue;
120 
121 		err = uas_submit_urbs(cmnd, cmnd->device->hostdata);
122 		if (!err)
123 			cmdinfo->state &= ~IS_IN_WORK_LIST;
124 		else
125 			queue_work(workqueue, &devinfo->work);
126 	}
127 out:
128 	spin_unlock_irqrestore(&devinfo->lock, flags);
129 }
130 
131 static void uas_scan_work(struct work_struct *work)
132 {
133 	struct uas_dev_info *devinfo =
134 		container_of(work, struct uas_dev_info, scan_work);
135 	struct Scsi_Host *shost = usb_get_intfdata(devinfo->intf);
136 
137 	dev_dbg(&devinfo->intf->dev, "starting scan\n");
138 	scsi_scan_host(shost);
139 	dev_dbg(&devinfo->intf->dev, "scan complete\n");
140 }
141 
142 static void uas_add_work(struct uas_cmd_info *cmdinfo)
143 {
144 	struct scsi_pointer *scp = (void *)cmdinfo;
145 	struct scsi_cmnd *cmnd = container_of(scp, struct scsi_cmnd, SCp);
146 	struct uas_dev_info *devinfo = cmnd->device->hostdata;
147 
148 	lockdep_assert_held(&devinfo->lock);
149 	cmdinfo->state |= IS_IN_WORK_LIST;
150 	queue_work(workqueue, &devinfo->work);
151 }
152 
153 static void uas_zap_pending(struct uas_dev_info *devinfo, int result)
154 {
155 	struct uas_cmd_info *cmdinfo;
156 	struct scsi_cmnd *cmnd;
157 	unsigned long flags;
158 	int i, err;
159 
160 	spin_lock_irqsave(&devinfo->lock, flags);
161 	for (i = 0; i < devinfo->qdepth; i++) {
162 		if (!devinfo->cmnd[i])
163 			continue;
164 
165 		cmnd = devinfo->cmnd[i];
166 		cmdinfo = (void *)&cmnd->SCp;
167 		uas_log_cmd_state(cmnd, __func__, 0);
168 		/* Sense urbs were killed, clear COMMAND_INFLIGHT manually */
169 		cmdinfo->state &= ~COMMAND_INFLIGHT;
170 		cmnd->result = result << 16;
171 		err = uas_try_complete(cmnd, __func__);
172 		WARN_ON(err != 0);
173 	}
174 	spin_unlock_irqrestore(&devinfo->lock, flags);
175 }
176 
177 static void uas_sense(struct urb *urb, struct scsi_cmnd *cmnd)
178 {
179 	struct sense_iu *sense_iu = urb->transfer_buffer;
180 	struct scsi_device *sdev = cmnd->device;
181 
182 	if (urb->actual_length > 16) {
183 		unsigned len = be16_to_cpup(&sense_iu->len);
184 		if (len + 16 != urb->actual_length) {
185 			int newlen = min(len + 16, urb->actual_length) - 16;
186 			if (newlen < 0)
187 				newlen = 0;
188 			sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
189 				"disagrees with IU sense data length %d, "
190 				"using %d bytes of sense data\n", __func__,
191 					urb->actual_length, len, newlen);
192 			len = newlen;
193 		}
194 		memcpy(cmnd->sense_buffer, sense_iu->sense, len);
195 	}
196 
197 	cmnd->result = sense_iu->status;
198 }
199 
200 static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *prefix,
201 			      int status)
202 {
203 	struct uas_cmd_info *ci = (void *)&cmnd->SCp;
204 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
205 
206 	if (status == -ENODEV) /* too late */
207 		return;
208 
209 	scmd_printk(KERN_INFO, cmnd,
210 		    "%s %d uas-tag %d inflight:%s%s%s%s%s%s%s%s%s%s%s%s ",
211 		    prefix, status, cmdinfo->uas_tag,
212 		    (ci->state & SUBMIT_STATUS_URB)     ? " s-st"  : "",
213 		    (ci->state & ALLOC_DATA_IN_URB)     ? " a-in"  : "",
214 		    (ci->state & SUBMIT_DATA_IN_URB)    ? " s-in"  : "",
215 		    (ci->state & ALLOC_DATA_OUT_URB)    ? " a-out" : "",
216 		    (ci->state & SUBMIT_DATA_OUT_URB)   ? " s-out" : "",
217 		    (ci->state & ALLOC_CMD_URB)         ? " a-cmd" : "",
218 		    (ci->state & SUBMIT_CMD_URB)        ? " s-cmd" : "",
219 		    (ci->state & COMMAND_INFLIGHT)      ? " CMD"   : "",
220 		    (ci->state & DATA_IN_URB_INFLIGHT)  ? " IN"    : "",
221 		    (ci->state & DATA_OUT_URB_INFLIGHT) ? " OUT"   : "",
222 		    (ci->state & COMMAND_ABORTED)       ? " abort" : "",
223 		    (ci->state & IS_IN_WORK_LIST)       ? " work"  : "");
224 	scsi_print_command(cmnd);
225 }
226 
227 static void uas_free_unsubmitted_urbs(struct scsi_cmnd *cmnd)
228 {
229 	struct uas_cmd_info *cmdinfo;
230 
231 	if (!cmnd)
232 		return;
233 
234 	cmdinfo = (void *)&cmnd->SCp;
235 
236 	if (cmdinfo->state & SUBMIT_CMD_URB)
237 		usb_free_urb(cmdinfo->cmd_urb);
238 
239 	/* data urbs may have never gotten their submit flag set */
240 	if (!(cmdinfo->state & DATA_IN_URB_INFLIGHT))
241 		usb_free_urb(cmdinfo->data_in_urb);
242 	if (!(cmdinfo->state & DATA_OUT_URB_INFLIGHT))
243 		usb_free_urb(cmdinfo->data_out_urb);
244 }
245 
246 static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller)
247 {
248 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
249 	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
250 
251 	lockdep_assert_held(&devinfo->lock);
252 	if (cmdinfo->state & (COMMAND_INFLIGHT |
253 			      DATA_IN_URB_INFLIGHT |
254 			      DATA_OUT_URB_INFLIGHT |
255 			      COMMAND_ABORTED))
256 		return -EBUSY;
257 	devinfo->cmnd[cmdinfo->uas_tag - 1] = NULL;
258 	uas_free_unsubmitted_urbs(cmnd);
259 	cmnd->scsi_done(cmnd);
260 	return 0;
261 }
262 
263 static void uas_xfer_data(struct urb *urb, struct scsi_cmnd *cmnd,
264 			  unsigned direction)
265 {
266 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
267 	int err;
268 
269 	cmdinfo->state |= direction | SUBMIT_STATUS_URB;
270 	err = uas_submit_urbs(cmnd, cmnd->device->hostdata);
271 	if (err) {
272 		uas_add_work(cmdinfo);
273 	}
274 }
275 
276 static bool uas_evaluate_response_iu(struct response_iu *riu, struct scsi_cmnd *cmnd)
277 {
278 	u8 response_code = riu->response_code;
279 
280 	switch (response_code) {
281 	case RC_INCORRECT_LUN:
282 		cmnd->result = DID_BAD_TARGET << 16;
283 		break;
284 	case RC_TMF_SUCCEEDED:
285 		cmnd->result = DID_OK << 16;
286 		break;
287 	case RC_TMF_NOT_SUPPORTED:
288 		cmnd->result = DID_TARGET_FAILURE << 16;
289 		break;
290 	default:
291 		uas_log_cmd_state(cmnd, "response iu", response_code);
292 		cmnd->result = DID_ERROR << 16;
293 		break;
294 	}
295 
296 	return response_code == RC_TMF_SUCCEEDED;
297 }
298 
299 static void uas_stat_cmplt(struct urb *urb)
300 {
301 	struct iu *iu = urb->transfer_buffer;
302 	struct Scsi_Host *shost = urb->context;
303 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
304 	struct urb *data_in_urb = NULL;
305 	struct urb *data_out_urb = NULL;
306 	struct scsi_cmnd *cmnd;
307 	struct uas_cmd_info *cmdinfo;
308 	unsigned long flags;
309 	unsigned int idx;
310 	int status = urb->status;
311 	bool success;
312 
313 	spin_lock_irqsave(&devinfo->lock, flags);
314 
315 	if (devinfo->resetting)
316 		goto out;
317 
318 	if (status) {
319 		if (status != -ENOENT && status != -ECONNRESET && status != -ESHUTDOWN)
320 			dev_err(&urb->dev->dev, "stat urb: status %d\n", status);
321 		goto out;
322 	}
323 
324 	idx = be16_to_cpup(&iu->tag) - 1;
325 	if (idx >= MAX_CMNDS || !devinfo->cmnd[idx]) {
326 		dev_err(&urb->dev->dev,
327 			"stat urb: no pending cmd for uas-tag %d\n", idx + 1);
328 		goto out;
329 	}
330 
331 	cmnd = devinfo->cmnd[idx];
332 	cmdinfo = (void *)&cmnd->SCp;
333 
334 	if (!(cmdinfo->state & COMMAND_INFLIGHT)) {
335 		uas_log_cmd_state(cmnd, "unexpected status cmplt", 0);
336 		goto out;
337 	}
338 
339 	switch (iu->iu_id) {
340 	case IU_ID_STATUS:
341 		uas_sense(urb, cmnd);
342 		if (cmnd->result != 0) {
343 			/* cancel data transfers on error */
344 			data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
345 			data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
346 		}
347 		cmdinfo->state &= ~COMMAND_INFLIGHT;
348 		uas_try_complete(cmnd, __func__);
349 		break;
350 	case IU_ID_READ_READY:
351 		if (!cmdinfo->data_in_urb ||
352 				(cmdinfo->state & DATA_IN_URB_INFLIGHT)) {
353 			uas_log_cmd_state(cmnd, "unexpected read rdy", 0);
354 			break;
355 		}
356 		uas_xfer_data(urb, cmnd, SUBMIT_DATA_IN_URB);
357 		break;
358 	case IU_ID_WRITE_READY:
359 		if (!cmdinfo->data_out_urb ||
360 				(cmdinfo->state & DATA_OUT_URB_INFLIGHT)) {
361 			uas_log_cmd_state(cmnd, "unexpected write rdy", 0);
362 			break;
363 		}
364 		uas_xfer_data(urb, cmnd, SUBMIT_DATA_OUT_URB);
365 		break;
366 	case IU_ID_RESPONSE:
367 		cmdinfo->state &= ~COMMAND_INFLIGHT;
368 		success = uas_evaluate_response_iu((struct response_iu *)iu, cmnd);
369 		if (!success) {
370 			/* Error, cancel data transfers */
371 			data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
372 			data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
373 		}
374 		uas_try_complete(cmnd, __func__);
375 		break;
376 	default:
377 		uas_log_cmd_state(cmnd, "bogus IU", iu->iu_id);
378 	}
379 out:
380 	usb_free_urb(urb);
381 	spin_unlock_irqrestore(&devinfo->lock, flags);
382 
383 	/* Unlinking of data urbs must be done without holding the lock */
384 	if (data_in_urb) {
385 		usb_unlink_urb(data_in_urb);
386 		usb_put_urb(data_in_urb);
387 	}
388 	if (data_out_urb) {
389 		usb_unlink_urb(data_out_urb);
390 		usb_put_urb(data_out_urb);
391 	}
392 }
393 
394 static void uas_data_cmplt(struct urb *urb)
395 {
396 	struct scsi_cmnd *cmnd = urb->context;
397 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
398 	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
399 	struct scsi_data_buffer *sdb = &cmnd->sdb;
400 	unsigned long flags;
401 	int status = urb->status;
402 
403 	spin_lock_irqsave(&devinfo->lock, flags);
404 
405 	if (cmdinfo->data_in_urb == urb) {
406 		cmdinfo->state &= ~DATA_IN_URB_INFLIGHT;
407 		cmdinfo->data_in_urb = NULL;
408 	} else if (cmdinfo->data_out_urb == urb) {
409 		cmdinfo->state &= ~DATA_OUT_URB_INFLIGHT;
410 		cmdinfo->data_out_urb = NULL;
411 	}
412 
413 	if (devinfo->resetting)
414 		goto out;
415 
416 	/* Data urbs should not complete before the cmd urb is submitted */
417 	if (cmdinfo->state & SUBMIT_CMD_URB) {
418 		uas_log_cmd_state(cmnd, "unexpected data cmplt", 0);
419 		goto out;
420 	}
421 
422 	if (status) {
423 		if (status != -ENOENT && status != -ECONNRESET && status != -ESHUTDOWN)
424 			uas_log_cmd_state(cmnd, "data cmplt err", status);
425 		/* error: no data transfered */
426 		scsi_set_resid(cmnd, sdb->length);
427 	} else {
428 		scsi_set_resid(cmnd, sdb->length - urb->actual_length);
429 	}
430 	uas_try_complete(cmnd, __func__);
431 out:
432 	usb_free_urb(urb);
433 	spin_unlock_irqrestore(&devinfo->lock, flags);
434 }
435 
436 static void uas_cmd_cmplt(struct urb *urb)
437 {
438 	if (urb->status)
439 		dev_err(&urb->dev->dev, "cmd cmplt err %d\n", urb->status);
440 
441 	usb_free_urb(urb);
442 }
443 
444 static struct urb *uas_alloc_data_urb(struct uas_dev_info *devinfo, gfp_t gfp,
445 				      struct scsi_cmnd *cmnd,
446 				      enum dma_data_direction dir)
447 {
448 	struct usb_device *udev = devinfo->udev;
449 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
450 	struct urb *urb = usb_alloc_urb(0, gfp);
451 	struct scsi_data_buffer *sdb = &cmnd->sdb;
452 	unsigned int pipe = (dir == DMA_FROM_DEVICE)
453 		? devinfo->data_in_pipe : devinfo->data_out_pipe;
454 
455 	if (!urb)
456 		goto out;
457 	usb_fill_bulk_urb(urb, udev, pipe, NULL, sdb->length,
458 			  uas_data_cmplt, cmnd);
459 	if (devinfo->use_streams)
460 		urb->stream_id = cmdinfo->uas_tag;
461 	urb->num_sgs = udev->bus->sg_tablesize ? sdb->table.nents : 0;
462 	urb->sg = sdb->table.sgl;
463  out:
464 	return urb;
465 }
466 
467 static struct urb *uas_alloc_sense_urb(struct uas_dev_info *devinfo, gfp_t gfp,
468 				       struct scsi_cmnd *cmnd)
469 {
470 	struct usb_device *udev = devinfo->udev;
471 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
472 	struct urb *urb = usb_alloc_urb(0, gfp);
473 	struct sense_iu *iu;
474 
475 	if (!urb)
476 		goto out;
477 
478 	iu = kzalloc(sizeof(*iu), gfp);
479 	if (!iu)
480 		goto free;
481 
482 	usb_fill_bulk_urb(urb, udev, devinfo->status_pipe, iu, sizeof(*iu),
483 			  uas_stat_cmplt, cmnd->device->host);
484 	if (devinfo->use_streams)
485 		urb->stream_id = cmdinfo->uas_tag;
486 	urb->transfer_flags |= URB_FREE_BUFFER;
487  out:
488 	return urb;
489  free:
490 	usb_free_urb(urb);
491 	return NULL;
492 }
493 
494 static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
495 					struct scsi_cmnd *cmnd)
496 {
497 	struct usb_device *udev = devinfo->udev;
498 	struct scsi_device *sdev = cmnd->device;
499 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
500 	struct urb *urb = usb_alloc_urb(0, gfp);
501 	struct command_iu *iu;
502 	int len;
503 
504 	if (!urb)
505 		goto out;
506 
507 	len = cmnd->cmd_len - 16;
508 	if (len < 0)
509 		len = 0;
510 	len = ALIGN(len, 4);
511 	iu = kzalloc(sizeof(*iu) + len, gfp);
512 	if (!iu)
513 		goto free;
514 
515 	iu->iu_id = IU_ID_COMMAND;
516 	iu->tag = cpu_to_be16(cmdinfo->uas_tag);
517 	iu->prio_attr = UAS_SIMPLE_TAG;
518 	iu->len = len;
519 	int_to_scsilun(sdev->lun, &iu->lun);
520 	memcpy(iu->cdb, cmnd->cmnd, cmnd->cmd_len);
521 
522 	usb_fill_bulk_urb(urb, udev, devinfo->cmd_pipe, iu, sizeof(*iu) + len,
523 							uas_cmd_cmplt, NULL);
524 	urb->transfer_flags |= URB_FREE_BUFFER;
525  out:
526 	return urb;
527  free:
528 	usb_free_urb(urb);
529 	return NULL;
530 }
531 
532 /*
533  * Why should I request the Status IU before sending the Command IU?  Spec
534  * says to, but also says the device may receive them in any order.  Seems
535  * daft to me.
536  */
537 
538 static struct urb *uas_submit_sense_urb(struct scsi_cmnd *cmnd, gfp_t gfp)
539 {
540 	struct uas_dev_info *devinfo = cmnd->device->hostdata;
541 	struct urb *urb;
542 	int err;
543 
544 	urb = uas_alloc_sense_urb(devinfo, gfp, cmnd);
545 	if (!urb)
546 		return NULL;
547 	usb_anchor_urb(urb, &devinfo->sense_urbs);
548 	err = usb_submit_urb(urb, gfp);
549 	if (err) {
550 		usb_unanchor_urb(urb);
551 		uas_log_cmd_state(cmnd, "sense submit err", err);
552 		usb_free_urb(urb);
553 		return NULL;
554 	}
555 	return urb;
556 }
557 
558 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
559 			   struct uas_dev_info *devinfo)
560 {
561 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
562 	struct urb *urb;
563 	int err;
564 
565 	lockdep_assert_held(&devinfo->lock);
566 	if (cmdinfo->state & SUBMIT_STATUS_URB) {
567 		urb = uas_submit_sense_urb(cmnd, GFP_ATOMIC);
568 		if (!urb)
569 			return SCSI_MLQUEUE_DEVICE_BUSY;
570 		cmdinfo->state &= ~SUBMIT_STATUS_URB;
571 	}
572 
573 	if (cmdinfo->state & ALLOC_DATA_IN_URB) {
574 		cmdinfo->data_in_urb = uas_alloc_data_urb(devinfo, GFP_ATOMIC,
575 							cmnd, DMA_FROM_DEVICE);
576 		if (!cmdinfo->data_in_urb)
577 			return SCSI_MLQUEUE_DEVICE_BUSY;
578 		cmdinfo->state &= ~ALLOC_DATA_IN_URB;
579 	}
580 
581 	if (cmdinfo->state & SUBMIT_DATA_IN_URB) {
582 		usb_anchor_urb(cmdinfo->data_in_urb, &devinfo->data_urbs);
583 		err = usb_submit_urb(cmdinfo->data_in_urb, GFP_ATOMIC);
584 		if (err) {
585 			usb_unanchor_urb(cmdinfo->data_in_urb);
586 			uas_log_cmd_state(cmnd, "data in submit err", err);
587 			return SCSI_MLQUEUE_DEVICE_BUSY;
588 		}
589 		cmdinfo->state &= ~SUBMIT_DATA_IN_URB;
590 		cmdinfo->state |= DATA_IN_URB_INFLIGHT;
591 	}
592 
593 	if (cmdinfo->state & ALLOC_DATA_OUT_URB) {
594 		cmdinfo->data_out_urb = uas_alloc_data_urb(devinfo, GFP_ATOMIC,
595 							cmnd, DMA_TO_DEVICE);
596 		if (!cmdinfo->data_out_urb)
597 			return SCSI_MLQUEUE_DEVICE_BUSY;
598 		cmdinfo->state &= ~ALLOC_DATA_OUT_URB;
599 	}
600 
601 	if (cmdinfo->state & SUBMIT_DATA_OUT_URB) {
602 		usb_anchor_urb(cmdinfo->data_out_urb, &devinfo->data_urbs);
603 		err = usb_submit_urb(cmdinfo->data_out_urb, GFP_ATOMIC);
604 		if (err) {
605 			usb_unanchor_urb(cmdinfo->data_out_urb);
606 			uas_log_cmd_state(cmnd, "data out submit err", err);
607 			return SCSI_MLQUEUE_DEVICE_BUSY;
608 		}
609 		cmdinfo->state &= ~SUBMIT_DATA_OUT_URB;
610 		cmdinfo->state |= DATA_OUT_URB_INFLIGHT;
611 	}
612 
613 	if (cmdinfo->state & ALLOC_CMD_URB) {
614 		cmdinfo->cmd_urb = uas_alloc_cmd_urb(devinfo, GFP_ATOMIC, cmnd);
615 		if (!cmdinfo->cmd_urb)
616 			return SCSI_MLQUEUE_DEVICE_BUSY;
617 		cmdinfo->state &= ~ALLOC_CMD_URB;
618 	}
619 
620 	if (cmdinfo->state & SUBMIT_CMD_URB) {
621 		usb_anchor_urb(cmdinfo->cmd_urb, &devinfo->cmd_urbs);
622 		err = usb_submit_urb(cmdinfo->cmd_urb, GFP_ATOMIC);
623 		if (err) {
624 			usb_unanchor_urb(cmdinfo->cmd_urb);
625 			uas_log_cmd_state(cmnd, "cmd submit err", err);
626 			return SCSI_MLQUEUE_DEVICE_BUSY;
627 		}
628 		cmdinfo->cmd_urb = NULL;
629 		cmdinfo->state &= ~SUBMIT_CMD_URB;
630 		cmdinfo->state |= COMMAND_INFLIGHT;
631 	}
632 
633 	return 0;
634 }
635 
636 static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,
637 					void (*done)(struct scsi_cmnd *))
638 {
639 	struct scsi_device *sdev = cmnd->device;
640 	struct uas_dev_info *devinfo = sdev->hostdata;
641 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
642 	unsigned long flags;
643 	int idx, err;
644 
645 	BUILD_BUG_ON(sizeof(struct uas_cmd_info) > sizeof(struct scsi_pointer));
646 
647 	/* Re-check scsi_block_requests now that we've the host-lock */
648 	if (cmnd->device->host->host_self_blocked)
649 		return SCSI_MLQUEUE_DEVICE_BUSY;
650 
651 	if ((devinfo->flags & US_FL_NO_ATA_1X) &&
652 			(cmnd->cmnd[0] == ATA_12 || cmnd->cmnd[0] == ATA_16)) {
653 		memcpy(cmnd->sense_buffer, usb_stor_sense_invalidCDB,
654 		       sizeof(usb_stor_sense_invalidCDB));
655 		cmnd->result = SAM_STAT_CHECK_CONDITION;
656 		cmnd->scsi_done(cmnd);
657 		return 0;
658 	}
659 
660 	spin_lock_irqsave(&devinfo->lock, flags);
661 
662 	if (devinfo->resetting) {
663 		cmnd->result = DID_ERROR << 16;
664 		cmnd->scsi_done(cmnd);
665 		spin_unlock_irqrestore(&devinfo->lock, flags);
666 		return 0;
667 	}
668 
669 	/* Find a free uas-tag */
670 	for (idx = 0; idx < devinfo->qdepth; idx++) {
671 		if (!devinfo->cmnd[idx])
672 			break;
673 	}
674 	if (idx == devinfo->qdepth) {
675 		spin_unlock_irqrestore(&devinfo->lock, flags);
676 		return SCSI_MLQUEUE_DEVICE_BUSY;
677 	}
678 
679 	cmnd->scsi_done = done;
680 
681 	memset(cmdinfo, 0, sizeof(*cmdinfo));
682 	cmdinfo->uas_tag = idx + 1; /* uas-tag == usb-stream-id, so 1 based */
683 	cmdinfo->state = SUBMIT_STATUS_URB | ALLOC_CMD_URB | SUBMIT_CMD_URB;
684 
685 	switch (cmnd->sc_data_direction) {
686 	case DMA_FROM_DEVICE:
687 		cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
688 		break;
689 	case DMA_BIDIRECTIONAL:
690 		cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
691 		/* fall through */
692 	case DMA_TO_DEVICE:
693 		cmdinfo->state |= ALLOC_DATA_OUT_URB | SUBMIT_DATA_OUT_URB;
694 	case DMA_NONE:
695 		break;
696 	}
697 
698 	if (!devinfo->use_streams)
699 		cmdinfo->state &= ~(SUBMIT_DATA_IN_URB | SUBMIT_DATA_OUT_URB);
700 
701 	err = uas_submit_urbs(cmnd, devinfo);
702 	if (err) {
703 		/* If we did nothing, give up now */
704 		if (cmdinfo->state & SUBMIT_STATUS_URB) {
705 			spin_unlock_irqrestore(&devinfo->lock, flags);
706 			return SCSI_MLQUEUE_DEVICE_BUSY;
707 		}
708 		uas_add_work(cmdinfo);
709 	}
710 
711 	devinfo->cmnd[idx] = cmnd;
712 	spin_unlock_irqrestore(&devinfo->lock, flags);
713 	return 0;
714 }
715 
716 static DEF_SCSI_QCMD(uas_queuecommand)
717 
718 /*
719  * For now we do not support actually sending an abort to the device, so
720  * this eh always fails. Still we must define it to make sure that we've
721  * dropped all references to the cmnd in question once this function exits.
722  */
723 static int uas_eh_abort_handler(struct scsi_cmnd *cmnd)
724 {
725 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
726 	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
727 	struct urb *data_in_urb = NULL;
728 	struct urb *data_out_urb = NULL;
729 	unsigned long flags;
730 
731 	spin_lock_irqsave(&devinfo->lock, flags);
732 
733 	uas_log_cmd_state(cmnd, __func__, 0);
734 
735 	/* Ensure that try_complete does not call scsi_done */
736 	cmdinfo->state |= COMMAND_ABORTED;
737 
738 	/* Drop all refs to this cmnd, kill data urbs to break their ref */
739 	devinfo->cmnd[cmdinfo->uas_tag - 1] = NULL;
740 	if (cmdinfo->state & DATA_IN_URB_INFLIGHT)
741 		data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
742 	if (cmdinfo->state & DATA_OUT_URB_INFLIGHT)
743 		data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
744 
745 	uas_free_unsubmitted_urbs(cmnd);
746 
747 	spin_unlock_irqrestore(&devinfo->lock, flags);
748 
749 	if (data_in_urb) {
750 		usb_kill_urb(data_in_urb);
751 		usb_put_urb(data_in_urb);
752 	}
753 	if (data_out_urb) {
754 		usb_kill_urb(data_out_urb);
755 		usb_put_urb(data_out_urb);
756 	}
757 
758 	return FAILED;
759 }
760 
761 static int uas_eh_device_reset_handler(struct scsi_cmnd *cmnd)
762 {
763 	struct scsi_device *sdev = cmnd->device;
764 	struct uas_dev_info *devinfo = sdev->hostdata;
765 	struct usb_device *udev = devinfo->udev;
766 	unsigned long flags;
767 	int err;
768 
769 	err = usb_lock_device_for_reset(udev, devinfo->intf);
770 	if (err) {
771 		shost_printk(KERN_ERR, sdev->host,
772 			     "%s FAILED to get lock err %d\n", __func__, err);
773 		return FAILED;
774 	}
775 
776 	shost_printk(KERN_INFO, sdev->host, "%s start\n", __func__);
777 
778 	spin_lock_irqsave(&devinfo->lock, flags);
779 	devinfo->resetting = 1;
780 	spin_unlock_irqrestore(&devinfo->lock, flags);
781 
782 	usb_kill_anchored_urbs(&devinfo->cmd_urbs);
783 	usb_kill_anchored_urbs(&devinfo->sense_urbs);
784 	usb_kill_anchored_urbs(&devinfo->data_urbs);
785 	uas_zap_pending(devinfo, DID_RESET);
786 
787 	err = usb_reset_device(udev);
788 
789 	spin_lock_irqsave(&devinfo->lock, flags);
790 	devinfo->resetting = 0;
791 	spin_unlock_irqrestore(&devinfo->lock, flags);
792 
793 	usb_unlock_device(udev);
794 
795 	if (err) {
796 		shost_printk(KERN_INFO, sdev->host, "%s FAILED err %d\n",
797 			     __func__, err);
798 		return FAILED;
799 	}
800 
801 	shost_printk(KERN_INFO, sdev->host, "%s success\n", __func__);
802 	return SUCCESS;
803 }
804 
805 static int uas_target_alloc(struct scsi_target *starget)
806 {
807 	struct uas_dev_info *devinfo = (struct uas_dev_info *)
808 			dev_to_shost(starget->dev.parent)->hostdata;
809 
810 	if (devinfo->flags & US_FL_NO_REPORT_LUNS)
811 		starget->no_report_luns = 1;
812 
813 	return 0;
814 }
815 
816 static int uas_slave_alloc(struct scsi_device *sdev)
817 {
818 	struct uas_dev_info *devinfo =
819 		(struct uas_dev_info *)sdev->host->hostdata;
820 
821 	sdev->hostdata = devinfo;
822 
823 	/*
824 	 * The protocol has no requirements on alignment in the strict sense.
825 	 * Controllers may or may not have alignment restrictions.
826 	 * As this is not exported, we use an extremely conservative guess.
827 	 */
828 	blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
829 
830 	if (devinfo->flags & US_FL_MAX_SECTORS_64)
831 		blk_queue_max_hw_sectors(sdev->request_queue, 64);
832 	else if (devinfo->flags & US_FL_MAX_SECTORS_240)
833 		blk_queue_max_hw_sectors(sdev->request_queue, 240);
834 
835 	return 0;
836 }
837 
838 static int uas_slave_configure(struct scsi_device *sdev)
839 {
840 	struct uas_dev_info *devinfo = sdev->hostdata;
841 
842 	if (devinfo->flags & US_FL_NO_REPORT_OPCODES)
843 		sdev->no_report_opcodes = 1;
844 
845 	/* A few buggy USB-ATA bridges don't understand FUA */
846 	if (devinfo->flags & US_FL_BROKEN_FUA)
847 		sdev->broken_fua = 1;
848 
849 	/* UAS also needs to support FL_ALWAYS_SYNC */
850 	if (devinfo->flags & US_FL_ALWAYS_SYNC) {
851 		sdev->skip_ms_page_3f = 1;
852 		sdev->skip_ms_page_8 = 1;
853 		sdev->wce_default_on = 1;
854 	}
855 
856 	/* Some disks cannot handle READ_CAPACITY_16 */
857 	if (devinfo->flags & US_FL_NO_READ_CAPACITY_16)
858 		sdev->no_read_capacity_16 = 1;
859 
860 	/*
861 	 * Some disks return the total number of blocks in response
862 	 * to READ CAPACITY rather than the highest block number.
863 	 * If this device makes that mistake, tell the sd driver.
864 	 */
865 	if (devinfo->flags & US_FL_FIX_CAPACITY)
866 		sdev->fix_capacity = 1;
867 
868 	/*
869 	 * in some cases we have to guess
870 	 */
871 	if (devinfo->flags & US_FL_CAPACITY_HEURISTICS)
872 		sdev->guess_capacity = 1;
873 
874 	/*
875 	 * Some devices don't like MODE SENSE with page=0x3f,
876 	 * which is the command used for checking if a device
877 	 * is write-protected.  Now that we tell the sd driver
878 	 * to do a 192-byte transfer with this command the
879 	 * majority of devices work fine, but a few still can't
880 	 * handle it.  The sd driver will simply assume those
881 	 * devices are write-enabled.
882 	 */
883 	if (devinfo->flags & US_FL_NO_WP_DETECT)
884 		sdev->skip_ms_page_3f = 1;
885 
886 	scsi_change_queue_depth(sdev, devinfo->qdepth - 2);
887 	return 0;
888 }
889 
890 static struct scsi_host_template uas_host_template = {
891 	.module = THIS_MODULE,
892 	.name = "uas",
893 	.queuecommand = uas_queuecommand,
894 	.target_alloc = uas_target_alloc,
895 	.slave_alloc = uas_slave_alloc,
896 	.slave_configure = uas_slave_configure,
897 	.eh_abort_handler = uas_eh_abort_handler,
898 	.eh_device_reset_handler = uas_eh_device_reset_handler,
899 	.this_id = -1,
900 	.skip_settle_delay = 1,
901 	.dma_boundary = PAGE_SIZE - 1,
902 };
903 
904 #define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
905 		    vendorName, productName, useProtocol, useTransport, \
906 		    initFunction, flags) \
907 { USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
908 	.driver_info = (flags) }
909 
910 static struct usb_device_id uas_usb_ids[] = {
911 #	include "unusual_uas.h"
912 	{ USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_BULK) },
913 	{ USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_UAS) },
914 	{ }
915 };
916 MODULE_DEVICE_TABLE(usb, uas_usb_ids);
917 
918 #undef UNUSUAL_DEV
919 
920 static int uas_switch_interface(struct usb_device *udev,
921 				struct usb_interface *intf)
922 {
923 	struct usb_host_interface *alt;
924 
925 	alt = uas_find_uas_alt_setting(intf);
926 	if (!alt)
927 		return -ENODEV;
928 
929 	return usb_set_interface(udev, alt->desc.bInterfaceNumber,
930 			alt->desc.bAlternateSetting);
931 }
932 
933 static int uas_configure_endpoints(struct uas_dev_info *devinfo)
934 {
935 	struct usb_host_endpoint *eps[4] = { };
936 	struct usb_device *udev = devinfo->udev;
937 	int r;
938 
939 	r = uas_find_endpoints(devinfo->intf->cur_altsetting, eps);
940 	if (r)
941 		return r;
942 
943 	devinfo->cmd_pipe = usb_sndbulkpipe(udev,
944 					    usb_endpoint_num(&eps[0]->desc));
945 	devinfo->status_pipe = usb_rcvbulkpipe(udev,
946 					    usb_endpoint_num(&eps[1]->desc));
947 	devinfo->data_in_pipe = usb_rcvbulkpipe(udev,
948 					    usb_endpoint_num(&eps[2]->desc));
949 	devinfo->data_out_pipe = usb_sndbulkpipe(udev,
950 					    usb_endpoint_num(&eps[3]->desc));
951 
952 	if (udev->speed < USB_SPEED_SUPER) {
953 		devinfo->qdepth = 32;
954 		devinfo->use_streams = 0;
955 	} else {
956 		devinfo->qdepth = usb_alloc_streams(devinfo->intf, eps + 1,
957 						    3, MAX_CMNDS, GFP_NOIO);
958 		if (devinfo->qdepth < 0)
959 			return devinfo->qdepth;
960 		devinfo->use_streams = 1;
961 	}
962 
963 	return 0;
964 }
965 
966 static void uas_free_streams(struct uas_dev_info *devinfo)
967 {
968 	struct usb_device *udev = devinfo->udev;
969 	struct usb_host_endpoint *eps[3];
970 
971 	eps[0] = usb_pipe_endpoint(udev, devinfo->status_pipe);
972 	eps[1] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
973 	eps[2] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
974 	usb_free_streams(devinfo->intf, eps, 3, GFP_NOIO);
975 }
976 
977 static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id)
978 {
979 	int result = -ENOMEM;
980 	struct Scsi_Host *shost = NULL;
981 	struct uas_dev_info *devinfo;
982 	struct usb_device *udev = interface_to_usbdev(intf);
983 	unsigned long dev_flags;
984 
985 	if (!uas_use_uas_driver(intf, id, &dev_flags))
986 		return -ENODEV;
987 
988 	if (uas_switch_interface(udev, intf))
989 		return -ENODEV;
990 
991 	shost = scsi_host_alloc(&uas_host_template,
992 				sizeof(struct uas_dev_info));
993 	if (!shost)
994 		goto set_alt0;
995 
996 	shost->max_cmd_len = 16 + 252;
997 	shost->max_id = 1;
998 	shost->max_lun = 256;
999 	shost->max_channel = 0;
1000 	shost->sg_tablesize = udev->bus->sg_tablesize;
1001 
1002 	devinfo = (struct uas_dev_info *)shost->hostdata;
1003 	devinfo->intf = intf;
1004 	devinfo->udev = udev;
1005 	devinfo->resetting = 0;
1006 	devinfo->shutdown = 0;
1007 	devinfo->flags = dev_flags;
1008 	init_usb_anchor(&devinfo->cmd_urbs);
1009 	init_usb_anchor(&devinfo->sense_urbs);
1010 	init_usb_anchor(&devinfo->data_urbs);
1011 	spin_lock_init(&devinfo->lock);
1012 	INIT_WORK(&devinfo->work, uas_do_work);
1013 	INIT_WORK(&devinfo->scan_work, uas_scan_work);
1014 
1015 	result = uas_configure_endpoints(devinfo);
1016 	if (result)
1017 		goto set_alt0;
1018 
1019 	/*
1020 	 * 1 tag is reserved for untagged commands +
1021 	 * 1 tag to avoid off by one errors in some bridge firmwares
1022 	 */
1023 	shost->can_queue = devinfo->qdepth - 2;
1024 
1025 	usb_set_intfdata(intf, shost);
1026 	result = scsi_add_host(shost, &intf->dev);
1027 	if (result)
1028 		goto free_streams;
1029 
1030 	/* Submit the delayed_work for SCSI-device scanning */
1031 	schedule_work(&devinfo->scan_work);
1032 
1033 	return result;
1034 
1035 free_streams:
1036 	uas_free_streams(devinfo);
1037 	usb_set_intfdata(intf, NULL);
1038 set_alt0:
1039 	usb_set_interface(udev, intf->altsetting[0].desc.bInterfaceNumber, 0);
1040 	if (shost)
1041 		scsi_host_put(shost);
1042 	return result;
1043 }
1044 
1045 static int uas_cmnd_list_empty(struct uas_dev_info *devinfo)
1046 {
1047 	unsigned long flags;
1048 	int i, r = 1;
1049 
1050 	spin_lock_irqsave(&devinfo->lock, flags);
1051 
1052 	for (i = 0; i < devinfo->qdepth; i++) {
1053 		if (devinfo->cmnd[i]) {
1054 			r = 0; /* Not empty */
1055 			break;
1056 		}
1057 	}
1058 
1059 	spin_unlock_irqrestore(&devinfo->lock, flags);
1060 
1061 	return r;
1062 }
1063 
1064 /*
1065  * Wait for any pending cmnds to complete, on usb-2 sense_urbs may temporarily
1066  * get empty while there still is more work to do due to sense-urbs completing
1067  * with a READ/WRITE_READY iu code, so keep waiting until the list gets empty.
1068  */
1069 static int uas_wait_for_pending_cmnds(struct uas_dev_info *devinfo)
1070 {
1071 	unsigned long start_time;
1072 	int r;
1073 
1074 	start_time = jiffies;
1075 	do {
1076 		flush_work(&devinfo->work);
1077 
1078 		r = usb_wait_anchor_empty_timeout(&devinfo->sense_urbs, 5000);
1079 		if (r == 0)
1080 			return -ETIME;
1081 
1082 		r = usb_wait_anchor_empty_timeout(&devinfo->data_urbs, 500);
1083 		if (r == 0)
1084 			return -ETIME;
1085 
1086 		if (time_after(jiffies, start_time + 5 * HZ))
1087 			return -ETIME;
1088 	} while (!uas_cmnd_list_empty(devinfo));
1089 
1090 	return 0;
1091 }
1092 
1093 static int uas_pre_reset(struct usb_interface *intf)
1094 {
1095 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1096 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1097 	unsigned long flags;
1098 
1099 	if (devinfo->shutdown)
1100 		return 0;
1101 
1102 	/* Block new requests */
1103 	spin_lock_irqsave(shost->host_lock, flags);
1104 	scsi_block_requests(shost);
1105 	spin_unlock_irqrestore(shost->host_lock, flags);
1106 
1107 	if (uas_wait_for_pending_cmnds(devinfo) != 0) {
1108 		shost_printk(KERN_ERR, shost, "%s: timed out\n", __func__);
1109 		scsi_unblock_requests(shost);
1110 		return 1;
1111 	}
1112 
1113 	uas_free_streams(devinfo);
1114 
1115 	return 0;
1116 }
1117 
1118 static int uas_post_reset(struct usb_interface *intf)
1119 {
1120 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1121 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1122 	unsigned long flags;
1123 	int err;
1124 
1125 	if (devinfo->shutdown)
1126 		return 0;
1127 
1128 	err = uas_configure_endpoints(devinfo);
1129 	if (err && err != -ENODEV)
1130 		shost_printk(KERN_ERR, shost,
1131 			     "%s: alloc streams error %d after reset",
1132 			     __func__, err);
1133 
1134 	/* we must unblock the host in every case lest we deadlock */
1135 	spin_lock_irqsave(shost->host_lock, flags);
1136 	scsi_report_bus_reset(shost, 0);
1137 	spin_unlock_irqrestore(shost->host_lock, flags);
1138 
1139 	scsi_unblock_requests(shost);
1140 
1141 	return err ? 1 : 0;
1142 }
1143 
1144 static int uas_suspend(struct usb_interface *intf, pm_message_t message)
1145 {
1146 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1147 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1148 
1149 	if (uas_wait_for_pending_cmnds(devinfo) != 0) {
1150 		shost_printk(KERN_ERR, shost, "%s: timed out\n", __func__);
1151 		return -ETIME;
1152 	}
1153 
1154 	return 0;
1155 }
1156 
1157 static int uas_resume(struct usb_interface *intf)
1158 {
1159 	return 0;
1160 }
1161 
1162 static int uas_reset_resume(struct usb_interface *intf)
1163 {
1164 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1165 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1166 	unsigned long flags;
1167 	int err;
1168 
1169 	err = uas_configure_endpoints(devinfo);
1170 	if (err) {
1171 		shost_printk(KERN_ERR, shost,
1172 			     "%s: alloc streams error %d after reset",
1173 			     __func__, err);
1174 		return -EIO;
1175 	}
1176 
1177 	spin_lock_irqsave(shost->host_lock, flags);
1178 	scsi_report_bus_reset(shost, 0);
1179 	spin_unlock_irqrestore(shost->host_lock, flags);
1180 
1181 	return 0;
1182 }
1183 
1184 static void uas_disconnect(struct usb_interface *intf)
1185 {
1186 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1187 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1188 	unsigned long flags;
1189 
1190 	spin_lock_irqsave(&devinfo->lock, flags);
1191 	devinfo->resetting = 1;
1192 	spin_unlock_irqrestore(&devinfo->lock, flags);
1193 
1194 	cancel_work_sync(&devinfo->work);
1195 	usb_kill_anchored_urbs(&devinfo->cmd_urbs);
1196 	usb_kill_anchored_urbs(&devinfo->sense_urbs);
1197 	usb_kill_anchored_urbs(&devinfo->data_urbs);
1198 	uas_zap_pending(devinfo, DID_NO_CONNECT);
1199 
1200 	/*
1201 	 * Prevent SCSI scanning (if it hasn't started yet)
1202 	 * or wait for the SCSI-scanning routine to stop.
1203 	 */
1204 	cancel_work_sync(&devinfo->scan_work);
1205 
1206 	scsi_remove_host(shost);
1207 	uas_free_streams(devinfo);
1208 	scsi_host_put(shost);
1209 }
1210 
1211 /*
1212  * Put the device back in usb-storage mode on shutdown, as some BIOS-es
1213  * hang on reboot when the device is still in uas mode. Note the reset is
1214  * necessary as some devices won't revert to usb-storage mode without it.
1215  */
1216 static void uas_shutdown(struct device *dev)
1217 {
1218 	struct usb_interface *intf = to_usb_interface(dev);
1219 	struct usb_device *udev = interface_to_usbdev(intf);
1220 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1221 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1222 
1223 	if (system_state != SYSTEM_RESTART)
1224 		return;
1225 
1226 	devinfo->shutdown = 1;
1227 	uas_free_streams(devinfo);
1228 	usb_set_interface(udev, intf->altsetting[0].desc.bInterfaceNumber, 0);
1229 	usb_reset_device(udev);
1230 }
1231 
1232 static struct usb_driver uas_driver = {
1233 	.name = "uas",
1234 	.probe = uas_probe,
1235 	.disconnect = uas_disconnect,
1236 	.pre_reset = uas_pre_reset,
1237 	.post_reset = uas_post_reset,
1238 	.suspend = uas_suspend,
1239 	.resume = uas_resume,
1240 	.reset_resume = uas_reset_resume,
1241 	.drvwrap.driver.shutdown = uas_shutdown,
1242 	.id_table = uas_usb_ids,
1243 };
1244 
1245 static int __init uas_init(void)
1246 {
1247 	int rv;
1248 
1249 	workqueue = alloc_workqueue("uas", WQ_MEM_RECLAIM, 0);
1250 	if (!workqueue)
1251 		return -ENOMEM;
1252 
1253 	rv = usb_register(&uas_driver);
1254 	if (rv) {
1255 		destroy_workqueue(workqueue);
1256 		return -ENOMEM;
1257 	}
1258 
1259 	return 0;
1260 }
1261 
1262 static void __exit uas_exit(void)
1263 {
1264 	usb_deregister(&uas_driver);
1265 	destroy_workqueue(workqueue);
1266 }
1267 
1268 module_init(uas_init);
1269 module_exit(uas_exit);
1270 
1271 MODULE_LICENSE("GPL");
1272 MODULE_IMPORT_NS(USB_STORAGE);
1273 MODULE_AUTHOR(
1274 	"Hans de Goede <hdegoede@redhat.com>, Matthew Wilcox and Sarah Sharp");
1275