xref: /openbmc/linux/drivers/usb/storage/uas.c (revision 1e8fc4ff)
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 = scsi_cmd_priv(cmnd);
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 scsi_cmnd *cmnd)
143 {
144 	struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
145 	struct uas_dev_info *devinfo = cmnd->device->hostdata;
146 
147 	lockdep_assert_held(&devinfo->lock);
148 	cmdinfo->state |= IS_IN_WORK_LIST;
149 	queue_work(workqueue, &devinfo->work);
150 }
151 
152 static void uas_zap_pending(struct uas_dev_info *devinfo, int result)
153 {
154 	struct uas_cmd_info *cmdinfo;
155 	struct scsi_cmnd *cmnd;
156 	unsigned long flags;
157 	int i, err;
158 
159 	spin_lock_irqsave(&devinfo->lock, flags);
160 	for (i = 0; i < devinfo->qdepth; i++) {
161 		if (!devinfo->cmnd[i])
162 			continue;
163 
164 		cmnd = devinfo->cmnd[i];
165 		cmdinfo = scsi_cmd_priv(cmnd);
166 		uas_log_cmd_state(cmnd, __func__, 0);
167 		/* Sense urbs were killed, clear COMMAND_INFLIGHT manually */
168 		cmdinfo->state &= ~COMMAND_INFLIGHT;
169 		cmnd->result = result << 16;
170 		err = uas_try_complete(cmnd, __func__);
171 		WARN_ON(err != 0);
172 	}
173 	spin_unlock_irqrestore(&devinfo->lock, flags);
174 }
175 
176 static void uas_sense(struct urb *urb, struct scsi_cmnd *cmnd)
177 {
178 	struct sense_iu *sense_iu = urb->transfer_buffer;
179 	struct scsi_device *sdev = cmnd->device;
180 
181 	if (urb->actual_length > 16) {
182 		unsigned len = be16_to_cpup(&sense_iu->len);
183 		if (len + 16 != urb->actual_length) {
184 			int newlen = min(len + 16, urb->actual_length) - 16;
185 			if (newlen < 0)
186 				newlen = 0;
187 			sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
188 				"disagrees with IU sense data length %d, "
189 				"using %d bytes of sense data\n", __func__,
190 					urb->actual_length, len, newlen);
191 			len = newlen;
192 		}
193 		memcpy(cmnd->sense_buffer, sense_iu->sense, len);
194 	}
195 
196 	cmnd->result = sense_iu->status;
197 }
198 
199 static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *prefix,
200 			      int status)
201 {
202 	struct uas_cmd_info *ci = scsi_cmd_priv(cmnd);
203 
204 	if (status == -ENODEV) /* too late */
205 		return;
206 
207 	scmd_printk(KERN_INFO, cmnd,
208 		    "%s %d uas-tag %d inflight:%s%s%s%s%s%s%s%s%s%s%s%s ",
209 		    prefix, status, ci->uas_tag,
210 		    (ci->state & SUBMIT_STATUS_URB)     ? " s-st"  : "",
211 		    (ci->state & ALLOC_DATA_IN_URB)     ? " a-in"  : "",
212 		    (ci->state & SUBMIT_DATA_IN_URB)    ? " s-in"  : "",
213 		    (ci->state & ALLOC_DATA_OUT_URB)    ? " a-out" : "",
214 		    (ci->state & SUBMIT_DATA_OUT_URB)   ? " s-out" : "",
215 		    (ci->state & ALLOC_CMD_URB)         ? " a-cmd" : "",
216 		    (ci->state & SUBMIT_CMD_URB)        ? " s-cmd" : "",
217 		    (ci->state & COMMAND_INFLIGHT)      ? " CMD"   : "",
218 		    (ci->state & DATA_IN_URB_INFLIGHT)  ? " IN"    : "",
219 		    (ci->state & DATA_OUT_URB_INFLIGHT) ? " OUT"   : "",
220 		    (ci->state & COMMAND_ABORTED)       ? " abort" : "",
221 		    (ci->state & IS_IN_WORK_LIST)       ? " work"  : "");
222 	scsi_print_command(cmnd);
223 }
224 
225 static void uas_free_unsubmitted_urbs(struct scsi_cmnd *cmnd)
226 {
227 	struct uas_cmd_info *cmdinfo;
228 
229 	if (!cmnd)
230 		return;
231 
232 	cmdinfo = scsi_cmd_priv(cmnd);
233 
234 	if (cmdinfo->state & SUBMIT_CMD_URB)
235 		usb_free_urb(cmdinfo->cmd_urb);
236 
237 	/* data urbs may have never gotten their submit flag set */
238 	if (!(cmdinfo->state & DATA_IN_URB_INFLIGHT))
239 		usb_free_urb(cmdinfo->data_in_urb);
240 	if (!(cmdinfo->state & DATA_OUT_URB_INFLIGHT))
241 		usb_free_urb(cmdinfo->data_out_urb);
242 }
243 
244 static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller)
245 {
246 	struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
247 	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
248 
249 	lockdep_assert_held(&devinfo->lock);
250 	if (cmdinfo->state & (COMMAND_INFLIGHT |
251 			      DATA_IN_URB_INFLIGHT |
252 			      DATA_OUT_URB_INFLIGHT |
253 			      COMMAND_ABORTED))
254 		return -EBUSY;
255 	devinfo->cmnd[cmdinfo->uas_tag - 1] = NULL;
256 	uas_free_unsubmitted_urbs(cmnd);
257 	scsi_done(cmnd);
258 	return 0;
259 }
260 
261 static void uas_xfer_data(struct urb *urb, struct scsi_cmnd *cmnd,
262 			  unsigned direction)
263 {
264 	struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
265 	int err;
266 
267 	cmdinfo->state |= direction | SUBMIT_STATUS_URB;
268 	err = uas_submit_urbs(cmnd, cmnd->device->hostdata);
269 	if (err) {
270 		uas_add_work(cmnd);
271 	}
272 }
273 
274 static bool uas_evaluate_response_iu(struct response_iu *riu, struct scsi_cmnd *cmnd)
275 {
276 	u8 response_code = riu->response_code;
277 
278 	switch (response_code) {
279 	case RC_INCORRECT_LUN:
280 		set_host_byte(cmnd, DID_BAD_TARGET);
281 		break;
282 	case RC_TMF_SUCCEEDED:
283 		set_host_byte(cmnd, DID_OK);
284 		break;
285 	case RC_TMF_NOT_SUPPORTED:
286 		set_host_byte(cmnd, DID_BAD_TARGET);
287 		break;
288 	default:
289 		uas_log_cmd_state(cmnd, "response iu", response_code);
290 		set_host_byte(cmnd, DID_ERROR);
291 		break;
292 	}
293 
294 	return response_code == RC_TMF_SUCCEEDED;
295 }
296 
297 static void uas_stat_cmplt(struct urb *urb)
298 {
299 	struct iu *iu = urb->transfer_buffer;
300 	struct Scsi_Host *shost = urb->context;
301 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
302 	struct urb *data_in_urb = NULL;
303 	struct urb *data_out_urb = NULL;
304 	struct scsi_cmnd *cmnd;
305 	struct uas_cmd_info *cmdinfo;
306 	unsigned long flags;
307 	unsigned int idx;
308 	int status = urb->status;
309 	bool success;
310 
311 	spin_lock_irqsave(&devinfo->lock, flags);
312 
313 	if (devinfo->resetting)
314 		goto out;
315 
316 	if (status) {
317 		if (status != -ENOENT && status != -ECONNRESET && status != -ESHUTDOWN)
318 			dev_err(&urb->dev->dev, "stat urb: status %d\n", status);
319 		goto out;
320 	}
321 
322 	idx = be16_to_cpup(&iu->tag) - 1;
323 	if (idx >= MAX_CMNDS || !devinfo->cmnd[idx]) {
324 		dev_err(&urb->dev->dev,
325 			"stat urb: no pending cmd for uas-tag %d\n", idx + 1);
326 		goto out;
327 	}
328 
329 	cmnd = devinfo->cmnd[idx];
330 	cmdinfo = scsi_cmd_priv(cmnd);
331 
332 	if (!(cmdinfo->state & COMMAND_INFLIGHT)) {
333 		uas_log_cmd_state(cmnd, "unexpected status cmplt", 0);
334 		goto out;
335 	}
336 
337 	switch (iu->iu_id) {
338 	case IU_ID_STATUS:
339 		uas_sense(urb, cmnd);
340 		if (cmnd->result != 0) {
341 			/* cancel data transfers on error */
342 			data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
343 			data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
344 		}
345 		cmdinfo->state &= ~COMMAND_INFLIGHT;
346 		uas_try_complete(cmnd, __func__);
347 		break;
348 	case IU_ID_READ_READY:
349 		if (!cmdinfo->data_in_urb ||
350 				(cmdinfo->state & DATA_IN_URB_INFLIGHT)) {
351 			uas_log_cmd_state(cmnd, "unexpected read rdy", 0);
352 			break;
353 		}
354 		uas_xfer_data(urb, cmnd, SUBMIT_DATA_IN_URB);
355 		break;
356 	case IU_ID_WRITE_READY:
357 		if (!cmdinfo->data_out_urb ||
358 				(cmdinfo->state & DATA_OUT_URB_INFLIGHT)) {
359 			uas_log_cmd_state(cmnd, "unexpected write rdy", 0);
360 			break;
361 		}
362 		uas_xfer_data(urb, cmnd, SUBMIT_DATA_OUT_URB);
363 		break;
364 	case IU_ID_RESPONSE:
365 		cmdinfo->state &= ~COMMAND_INFLIGHT;
366 		success = uas_evaluate_response_iu((struct response_iu *)iu, cmnd);
367 		if (!success) {
368 			/* Error, cancel data transfers */
369 			data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
370 			data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
371 		}
372 		uas_try_complete(cmnd, __func__);
373 		break;
374 	default:
375 		uas_log_cmd_state(cmnd, "bogus IU", iu->iu_id);
376 	}
377 out:
378 	usb_free_urb(urb);
379 	spin_unlock_irqrestore(&devinfo->lock, flags);
380 
381 	/* Unlinking of data urbs must be done without holding the lock */
382 	if (data_in_urb) {
383 		usb_unlink_urb(data_in_urb);
384 		usb_put_urb(data_in_urb);
385 	}
386 	if (data_out_urb) {
387 		usb_unlink_urb(data_out_urb);
388 		usb_put_urb(data_out_urb);
389 	}
390 }
391 
392 static void uas_data_cmplt(struct urb *urb)
393 {
394 	struct scsi_cmnd *cmnd = urb->context;
395 	struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
396 	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
397 	struct scsi_data_buffer *sdb = &cmnd->sdb;
398 	unsigned long flags;
399 	int status = urb->status;
400 
401 	spin_lock_irqsave(&devinfo->lock, flags);
402 
403 	if (cmdinfo->data_in_urb == urb) {
404 		cmdinfo->state &= ~DATA_IN_URB_INFLIGHT;
405 		cmdinfo->data_in_urb = NULL;
406 	} else if (cmdinfo->data_out_urb == urb) {
407 		cmdinfo->state &= ~DATA_OUT_URB_INFLIGHT;
408 		cmdinfo->data_out_urb = NULL;
409 	}
410 
411 	if (devinfo->resetting)
412 		goto out;
413 
414 	/* Data urbs should not complete before the cmd urb is submitted */
415 	if (cmdinfo->state & SUBMIT_CMD_URB) {
416 		uas_log_cmd_state(cmnd, "unexpected data cmplt", 0);
417 		goto out;
418 	}
419 
420 	if (status) {
421 		if (status != -ENOENT && status != -ECONNRESET && status != -ESHUTDOWN)
422 			uas_log_cmd_state(cmnd, "data cmplt err", status);
423 		/* error: no data transfered */
424 		scsi_set_resid(cmnd, sdb->length);
425 		set_host_byte(cmnd, DID_ERROR);
426 	} else {
427 		scsi_set_resid(cmnd, sdb->length - urb->actual_length);
428 	}
429 	uas_try_complete(cmnd, __func__);
430 out:
431 	usb_free_urb(urb);
432 	spin_unlock_irqrestore(&devinfo->lock, flags);
433 }
434 
435 static void uas_cmd_cmplt(struct urb *urb)
436 {
437 	if (urb->status)
438 		dev_err(&urb->dev->dev, "cmd cmplt err %d\n", urb->status);
439 
440 	usb_free_urb(urb);
441 }
442 
443 static struct urb *uas_alloc_data_urb(struct uas_dev_info *devinfo, gfp_t gfp,
444 				      struct scsi_cmnd *cmnd,
445 				      enum dma_data_direction dir)
446 {
447 	struct usb_device *udev = devinfo->udev;
448 	struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
449 	struct urb *urb = usb_alloc_urb(0, gfp);
450 	struct scsi_data_buffer *sdb = &cmnd->sdb;
451 	unsigned int pipe = (dir == DMA_FROM_DEVICE)
452 		? devinfo->data_in_pipe : devinfo->data_out_pipe;
453 
454 	if (!urb)
455 		goto out;
456 	usb_fill_bulk_urb(urb, udev, pipe, NULL, sdb->length,
457 			  uas_data_cmplt, cmnd);
458 	if (devinfo->use_streams)
459 		urb->stream_id = cmdinfo->uas_tag;
460 	urb->num_sgs = udev->bus->sg_tablesize ? sdb->table.nents : 0;
461 	urb->sg = sdb->table.sgl;
462  out:
463 	return urb;
464 }
465 
466 static struct urb *uas_alloc_sense_urb(struct uas_dev_info *devinfo, gfp_t gfp,
467 				       struct scsi_cmnd *cmnd)
468 {
469 	struct usb_device *udev = devinfo->udev;
470 	struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
471 	struct urb *urb = usb_alloc_urb(0, gfp);
472 	struct sense_iu *iu;
473 
474 	if (!urb)
475 		goto out;
476 
477 	iu = kzalloc(sizeof(*iu), gfp);
478 	if (!iu)
479 		goto free;
480 
481 	usb_fill_bulk_urb(urb, udev, devinfo->status_pipe, iu, sizeof(*iu),
482 			  uas_stat_cmplt, cmnd->device->host);
483 	if (devinfo->use_streams)
484 		urb->stream_id = cmdinfo->uas_tag;
485 	urb->transfer_flags |= URB_FREE_BUFFER;
486  out:
487 	return urb;
488  free:
489 	usb_free_urb(urb);
490 	return NULL;
491 }
492 
493 static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
494 					struct scsi_cmnd *cmnd)
495 {
496 	struct usb_device *udev = devinfo->udev;
497 	struct scsi_device *sdev = cmnd->device;
498 	struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
499 	struct urb *urb = usb_alloc_urb(0, gfp);
500 	struct command_iu *iu;
501 	int len;
502 
503 	if (!urb)
504 		goto out;
505 
506 	len = cmnd->cmd_len - 16;
507 	if (len < 0)
508 		len = 0;
509 	len = ALIGN(len, 4);
510 	iu = kzalloc(sizeof(*iu) + len, gfp);
511 	if (!iu)
512 		goto free;
513 
514 	iu->iu_id = IU_ID_COMMAND;
515 	iu->tag = cpu_to_be16(cmdinfo->uas_tag);
516 	iu->prio_attr = UAS_SIMPLE_TAG;
517 	iu->len = len;
518 	int_to_scsilun(sdev->lun, &iu->lun);
519 	memcpy(iu->cdb, cmnd->cmnd, cmnd->cmd_len);
520 
521 	usb_fill_bulk_urb(urb, udev, devinfo->cmd_pipe, iu, sizeof(*iu) + len,
522 							uas_cmd_cmplt, NULL);
523 	urb->transfer_flags |= URB_FREE_BUFFER;
524  out:
525 	return urb;
526  free:
527 	usb_free_urb(urb);
528 	return NULL;
529 }
530 
531 /*
532  * Why should I request the Status IU before sending the Command IU?  Spec
533  * says to, but also says the device may receive them in any order.  Seems
534  * daft to me.
535  */
536 
537 static int uas_submit_sense_urb(struct scsi_cmnd *cmnd, gfp_t gfp)
538 {
539 	struct uas_dev_info *devinfo = cmnd->device->hostdata;
540 	struct urb *urb;
541 	int err;
542 
543 	urb = uas_alloc_sense_urb(devinfo, gfp, cmnd);
544 	if (!urb)
545 		return -ENOMEM;
546 	usb_anchor_urb(urb, &devinfo->sense_urbs);
547 	err = usb_submit_urb(urb, gfp);
548 	if (err) {
549 		usb_unanchor_urb(urb);
550 		uas_log_cmd_state(cmnd, "sense submit err", err);
551 		usb_free_urb(urb);
552 	}
553 	return err;
554 }
555 
556 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
557 			   struct uas_dev_info *devinfo)
558 {
559 	struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
560 	int err;
561 
562 	lockdep_assert_held(&devinfo->lock);
563 	if (cmdinfo->state & SUBMIT_STATUS_URB) {
564 		err = uas_submit_sense_urb(cmnd, GFP_ATOMIC);
565 		if (err)
566 			return err;
567 		cmdinfo->state &= ~SUBMIT_STATUS_URB;
568 	}
569 
570 	if (cmdinfo->state & ALLOC_DATA_IN_URB) {
571 		cmdinfo->data_in_urb = uas_alloc_data_urb(devinfo, GFP_ATOMIC,
572 							cmnd, DMA_FROM_DEVICE);
573 		if (!cmdinfo->data_in_urb)
574 			return -ENOMEM;
575 		cmdinfo->state &= ~ALLOC_DATA_IN_URB;
576 	}
577 
578 	if (cmdinfo->state & SUBMIT_DATA_IN_URB) {
579 		usb_anchor_urb(cmdinfo->data_in_urb, &devinfo->data_urbs);
580 		err = usb_submit_urb(cmdinfo->data_in_urb, GFP_ATOMIC);
581 		if (err) {
582 			usb_unanchor_urb(cmdinfo->data_in_urb);
583 			uas_log_cmd_state(cmnd, "data in submit err", err);
584 			return err;
585 		}
586 		cmdinfo->state &= ~SUBMIT_DATA_IN_URB;
587 		cmdinfo->state |= DATA_IN_URB_INFLIGHT;
588 	}
589 
590 	if (cmdinfo->state & ALLOC_DATA_OUT_URB) {
591 		cmdinfo->data_out_urb = uas_alloc_data_urb(devinfo, GFP_ATOMIC,
592 							cmnd, DMA_TO_DEVICE);
593 		if (!cmdinfo->data_out_urb)
594 			return -ENOMEM;
595 		cmdinfo->state &= ~ALLOC_DATA_OUT_URB;
596 	}
597 
598 	if (cmdinfo->state & SUBMIT_DATA_OUT_URB) {
599 		usb_anchor_urb(cmdinfo->data_out_urb, &devinfo->data_urbs);
600 		err = usb_submit_urb(cmdinfo->data_out_urb, GFP_ATOMIC);
601 		if (err) {
602 			usb_unanchor_urb(cmdinfo->data_out_urb);
603 			uas_log_cmd_state(cmnd, "data out submit err", err);
604 			return err;
605 		}
606 		cmdinfo->state &= ~SUBMIT_DATA_OUT_URB;
607 		cmdinfo->state |= DATA_OUT_URB_INFLIGHT;
608 	}
609 
610 	if (cmdinfo->state & ALLOC_CMD_URB) {
611 		cmdinfo->cmd_urb = uas_alloc_cmd_urb(devinfo, GFP_ATOMIC, cmnd);
612 		if (!cmdinfo->cmd_urb)
613 			return -ENOMEM;
614 		cmdinfo->state &= ~ALLOC_CMD_URB;
615 	}
616 
617 	if (cmdinfo->state & SUBMIT_CMD_URB) {
618 		usb_anchor_urb(cmdinfo->cmd_urb, &devinfo->cmd_urbs);
619 		err = usb_submit_urb(cmdinfo->cmd_urb, GFP_ATOMIC);
620 		if (err) {
621 			usb_unanchor_urb(cmdinfo->cmd_urb);
622 			uas_log_cmd_state(cmnd, "cmd submit err", err);
623 			return err;
624 		}
625 		cmdinfo->cmd_urb = NULL;
626 		cmdinfo->state &= ~SUBMIT_CMD_URB;
627 		cmdinfo->state |= COMMAND_INFLIGHT;
628 	}
629 
630 	return 0;
631 }
632 
633 static int uas_queuecommand_lck(struct scsi_cmnd *cmnd)
634 {
635 	struct scsi_device *sdev = cmnd->device;
636 	struct uas_dev_info *devinfo = sdev->hostdata;
637 	struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
638 	unsigned long flags;
639 	int idx, err;
640 
641 	/* Re-check scsi_block_requests now that we've the host-lock */
642 	if (cmnd->device->host->host_self_blocked)
643 		return SCSI_MLQUEUE_DEVICE_BUSY;
644 
645 	if ((devinfo->flags & US_FL_NO_ATA_1X) &&
646 			(cmnd->cmnd[0] == ATA_12 || cmnd->cmnd[0] == ATA_16)) {
647 		memcpy(cmnd->sense_buffer, usb_stor_sense_invalidCDB,
648 		       sizeof(usb_stor_sense_invalidCDB));
649 		cmnd->result = SAM_STAT_CHECK_CONDITION;
650 		scsi_done(cmnd);
651 		return 0;
652 	}
653 
654 	spin_lock_irqsave(&devinfo->lock, flags);
655 
656 	if (devinfo->resetting) {
657 		set_host_byte(cmnd, DID_ERROR);
658 		scsi_done(cmnd);
659 		goto zombie;
660 	}
661 
662 	/* Find a free uas-tag */
663 	for (idx = 0; idx < devinfo->qdepth; idx++) {
664 		if (!devinfo->cmnd[idx])
665 			break;
666 	}
667 	if (idx == devinfo->qdepth) {
668 		spin_unlock_irqrestore(&devinfo->lock, flags);
669 		return SCSI_MLQUEUE_DEVICE_BUSY;
670 	}
671 
672 	memset(cmdinfo, 0, sizeof(*cmdinfo));
673 	cmdinfo->uas_tag = idx + 1; /* uas-tag == usb-stream-id, so 1 based */
674 	cmdinfo->state = SUBMIT_STATUS_URB | ALLOC_CMD_URB | SUBMIT_CMD_URB;
675 
676 	switch (cmnd->sc_data_direction) {
677 	case DMA_FROM_DEVICE:
678 		cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
679 		break;
680 	case DMA_BIDIRECTIONAL:
681 		cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
682 		fallthrough;
683 	case DMA_TO_DEVICE:
684 		cmdinfo->state |= ALLOC_DATA_OUT_URB | SUBMIT_DATA_OUT_URB;
685 		break;
686 	case DMA_NONE:
687 		break;
688 	}
689 
690 	if (!devinfo->use_streams)
691 		cmdinfo->state &= ~(SUBMIT_DATA_IN_URB | SUBMIT_DATA_OUT_URB);
692 
693 	err = uas_submit_urbs(cmnd, devinfo);
694 	/*
695 	 * in case of fatal errors the SCSI layer is peculiar
696 	 * a command that has finished is a success for the purpose
697 	 * of queueing, no matter how fatal the error
698 	 */
699 	if (err == -ENODEV) {
700 		set_host_byte(cmnd, DID_NO_CONNECT);
701 		scsi_done(cmnd);
702 		goto zombie;
703 	}
704 	if (err) {
705 		/* If we did nothing, give up now */
706 		if (cmdinfo->state & SUBMIT_STATUS_URB) {
707 			spin_unlock_irqrestore(&devinfo->lock, flags);
708 			return SCSI_MLQUEUE_DEVICE_BUSY;
709 		}
710 		uas_add_work(cmnd);
711 	}
712 
713 	devinfo->cmnd[idx] = cmnd;
714 zombie:
715 	spin_unlock_irqrestore(&devinfo->lock, flags);
716 	return 0;
717 }
718 
719 static DEF_SCSI_QCMD(uas_queuecommand)
720 
721 /*
722  * For now we do not support actually sending an abort to the device, so
723  * this eh always fails. Still we must define it to make sure that we've
724  * dropped all references to the cmnd in question once this function exits.
725  */
726 static int uas_eh_abort_handler(struct scsi_cmnd *cmnd)
727 {
728 	struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
729 	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
730 	struct urb *data_in_urb = NULL;
731 	struct urb *data_out_urb = NULL;
732 	unsigned long flags;
733 
734 	spin_lock_irqsave(&devinfo->lock, flags);
735 
736 	uas_log_cmd_state(cmnd, __func__, 0);
737 
738 	/* Ensure that try_complete does not call scsi_done */
739 	cmdinfo->state |= COMMAND_ABORTED;
740 
741 	/* Drop all refs to this cmnd, kill data urbs to break their ref */
742 	devinfo->cmnd[cmdinfo->uas_tag - 1] = NULL;
743 	if (cmdinfo->state & DATA_IN_URB_INFLIGHT)
744 		data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
745 	if (cmdinfo->state & DATA_OUT_URB_INFLIGHT)
746 		data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
747 
748 	uas_free_unsubmitted_urbs(cmnd);
749 
750 	spin_unlock_irqrestore(&devinfo->lock, flags);
751 
752 	if (data_in_urb) {
753 		usb_kill_urb(data_in_urb);
754 		usb_put_urb(data_in_urb);
755 	}
756 	if (data_out_urb) {
757 		usb_kill_urb(data_out_urb);
758 		usb_put_urb(data_out_urb);
759 	}
760 
761 	return FAILED;
762 }
763 
764 static int uas_eh_device_reset_handler(struct scsi_cmnd *cmnd)
765 {
766 	struct scsi_device *sdev = cmnd->device;
767 	struct uas_dev_info *devinfo = sdev->hostdata;
768 	struct usb_device *udev = devinfo->udev;
769 	unsigned long flags;
770 	int err;
771 
772 	err = usb_lock_device_for_reset(udev, devinfo->intf);
773 	if (err) {
774 		shost_printk(KERN_ERR, sdev->host,
775 			     "%s FAILED to get lock err %d\n", __func__, err);
776 		return FAILED;
777 	}
778 
779 	shost_printk(KERN_INFO, sdev->host, "%s start\n", __func__);
780 
781 	spin_lock_irqsave(&devinfo->lock, flags);
782 	devinfo->resetting = 1;
783 	spin_unlock_irqrestore(&devinfo->lock, flags);
784 
785 	usb_kill_anchored_urbs(&devinfo->cmd_urbs);
786 	usb_kill_anchored_urbs(&devinfo->sense_urbs);
787 	usb_kill_anchored_urbs(&devinfo->data_urbs);
788 	uas_zap_pending(devinfo, DID_RESET);
789 
790 	err = usb_reset_device(udev);
791 
792 	spin_lock_irqsave(&devinfo->lock, flags);
793 	devinfo->resetting = 0;
794 	spin_unlock_irqrestore(&devinfo->lock, flags);
795 
796 	usb_unlock_device(udev);
797 
798 	if (err) {
799 		shost_printk(KERN_INFO, sdev->host, "%s FAILED err %d\n",
800 			     __func__, err);
801 		return FAILED;
802 	}
803 
804 	shost_printk(KERN_INFO, sdev->host, "%s success\n", __func__);
805 	return SUCCESS;
806 }
807 
808 static int uas_target_alloc(struct scsi_target *starget)
809 {
810 	struct uas_dev_info *devinfo = (struct uas_dev_info *)
811 			dev_to_shost(starget->dev.parent)->hostdata;
812 
813 	if (devinfo->flags & US_FL_NO_REPORT_LUNS)
814 		starget->no_report_luns = 1;
815 
816 	return 0;
817 }
818 
819 static int uas_slave_alloc(struct scsi_device *sdev)
820 {
821 	struct uas_dev_info *devinfo =
822 		(struct uas_dev_info *)sdev->host->hostdata;
823 
824 	sdev->hostdata = devinfo;
825 
826 	/*
827 	 * The protocol has no requirements on alignment in the strict sense.
828 	 * Controllers may or may not have alignment restrictions.
829 	 * As this is not exported, we use an extremely conservative guess.
830 	 */
831 	blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
832 
833 	if (devinfo->flags & US_FL_MAX_SECTORS_64)
834 		blk_queue_max_hw_sectors(sdev->request_queue, 64);
835 	else if (devinfo->flags & US_FL_MAX_SECTORS_240)
836 		blk_queue_max_hw_sectors(sdev->request_queue, 240);
837 
838 	return 0;
839 }
840 
841 static int uas_slave_configure(struct scsi_device *sdev)
842 {
843 	struct uas_dev_info *devinfo = sdev->hostdata;
844 
845 	if (devinfo->flags & US_FL_NO_REPORT_OPCODES)
846 		sdev->no_report_opcodes = 1;
847 
848 	/* A few buggy USB-ATA bridges don't understand FUA */
849 	if (devinfo->flags & US_FL_BROKEN_FUA)
850 		sdev->broken_fua = 1;
851 
852 	/* UAS also needs to support FL_ALWAYS_SYNC */
853 	if (devinfo->flags & US_FL_ALWAYS_SYNC) {
854 		sdev->skip_ms_page_3f = 1;
855 		sdev->skip_ms_page_8 = 1;
856 		sdev->wce_default_on = 1;
857 	}
858 
859 	/* Some disks cannot handle READ_CAPACITY_16 */
860 	if (devinfo->flags & US_FL_NO_READ_CAPACITY_16)
861 		sdev->no_read_capacity_16 = 1;
862 
863 	/* Some disks cannot handle WRITE_SAME */
864 	if (devinfo->flags & US_FL_NO_SAME)
865 		sdev->no_write_same = 1;
866 	/*
867 	 * Some disks return the total number of blocks in response
868 	 * to READ CAPACITY rather than the highest block number.
869 	 * If this device makes that mistake, tell the sd driver.
870 	 */
871 	if (devinfo->flags & US_FL_FIX_CAPACITY)
872 		sdev->fix_capacity = 1;
873 
874 	/*
875 	 * in some cases we have to guess
876 	 */
877 	if (devinfo->flags & US_FL_CAPACITY_HEURISTICS)
878 		sdev->guess_capacity = 1;
879 
880 	/*
881 	 * Some devices report generic values until the media has been
882 	 * accessed. Force a READ(10) prior to querying device
883 	 * characteristics.
884 	 */
885 	sdev->read_before_ms = 1;
886 
887 	/*
888 	 * Some devices don't like MODE SENSE with page=0x3f,
889 	 * which is the command used for checking if a device
890 	 * is write-protected.  Now that we tell the sd driver
891 	 * to do a 192-byte transfer with this command the
892 	 * majority of devices work fine, but a few still can't
893 	 * handle it.  The sd driver will simply assume those
894 	 * devices are write-enabled.
895 	 */
896 	if (devinfo->flags & US_FL_NO_WP_DETECT)
897 		sdev->skip_ms_page_3f = 1;
898 
899 	scsi_change_queue_depth(sdev, devinfo->qdepth - 2);
900 	return 0;
901 }
902 
903 static const struct scsi_host_template uas_host_template = {
904 	.module = THIS_MODULE,
905 	.name = "uas",
906 	.queuecommand = uas_queuecommand,
907 	.target_alloc = uas_target_alloc,
908 	.slave_alloc = uas_slave_alloc,
909 	.slave_configure = uas_slave_configure,
910 	.eh_abort_handler = uas_eh_abort_handler,
911 	.eh_device_reset_handler = uas_eh_device_reset_handler,
912 	.this_id = -1,
913 	.skip_settle_delay = 1,
914 	.dma_boundary = PAGE_SIZE - 1,
915 	.cmd_size = sizeof(struct uas_cmd_info),
916 };
917 
918 #define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
919 		    vendorName, productName, useProtocol, useTransport, \
920 		    initFunction, flags) \
921 { USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
922 	.driver_info = (flags) }
923 
924 static struct usb_device_id uas_usb_ids[] = {
925 #	include "unusual_uas.h"
926 	{ USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_BULK) },
927 	{ USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_UAS) },
928 	{ }
929 };
930 MODULE_DEVICE_TABLE(usb, uas_usb_ids);
931 
932 #undef UNUSUAL_DEV
933 
934 static int uas_switch_interface(struct usb_device *udev,
935 				struct usb_interface *intf)
936 {
937 	struct usb_host_interface *alt;
938 
939 	alt = uas_find_uas_alt_setting(intf);
940 	if (!alt)
941 		return -ENODEV;
942 
943 	return usb_set_interface(udev, alt->desc.bInterfaceNumber,
944 			alt->desc.bAlternateSetting);
945 }
946 
947 static int uas_configure_endpoints(struct uas_dev_info *devinfo)
948 {
949 	struct usb_host_endpoint *eps[4] = { };
950 	struct usb_device *udev = devinfo->udev;
951 	int r;
952 
953 	r = uas_find_endpoints(devinfo->intf->cur_altsetting, eps);
954 	if (r)
955 		return r;
956 
957 	devinfo->cmd_pipe = usb_sndbulkpipe(udev,
958 					    usb_endpoint_num(&eps[0]->desc));
959 	devinfo->status_pipe = usb_rcvbulkpipe(udev,
960 					    usb_endpoint_num(&eps[1]->desc));
961 	devinfo->data_in_pipe = usb_rcvbulkpipe(udev,
962 					    usb_endpoint_num(&eps[2]->desc));
963 	devinfo->data_out_pipe = usb_sndbulkpipe(udev,
964 					    usb_endpoint_num(&eps[3]->desc));
965 
966 	if (udev->speed < USB_SPEED_SUPER) {
967 		devinfo->qdepth = 32;
968 		devinfo->use_streams = 0;
969 	} else {
970 		devinfo->qdepth = usb_alloc_streams(devinfo->intf, eps + 1,
971 						    3, MAX_CMNDS, GFP_NOIO);
972 		if (devinfo->qdepth < 0)
973 			return devinfo->qdepth;
974 		devinfo->use_streams = 1;
975 	}
976 
977 	return 0;
978 }
979 
980 static void uas_free_streams(struct uas_dev_info *devinfo)
981 {
982 	struct usb_device *udev = devinfo->udev;
983 	struct usb_host_endpoint *eps[3];
984 
985 	eps[0] = usb_pipe_endpoint(udev, devinfo->status_pipe);
986 	eps[1] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
987 	eps[2] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
988 	usb_free_streams(devinfo->intf, eps, 3, GFP_NOIO);
989 }
990 
991 static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id)
992 {
993 	int result = -ENOMEM;
994 	struct Scsi_Host *shost = NULL;
995 	struct uas_dev_info *devinfo;
996 	struct usb_device *udev = interface_to_usbdev(intf);
997 	unsigned long dev_flags;
998 
999 	if (!uas_use_uas_driver(intf, id, &dev_flags))
1000 		return -ENODEV;
1001 
1002 	if (uas_switch_interface(udev, intf))
1003 		return -ENODEV;
1004 
1005 	shost = scsi_host_alloc(&uas_host_template,
1006 				sizeof(struct uas_dev_info));
1007 	if (!shost)
1008 		goto set_alt0;
1009 
1010 	shost->max_cmd_len = 16 + 252;
1011 	shost->max_id = 1;
1012 	shost->max_lun = 256;
1013 	shost->max_channel = 0;
1014 	shost->sg_tablesize = udev->bus->sg_tablesize;
1015 
1016 	devinfo = (struct uas_dev_info *)shost->hostdata;
1017 	devinfo->intf = intf;
1018 	devinfo->udev = udev;
1019 	devinfo->resetting = 0;
1020 	devinfo->shutdown = 0;
1021 	devinfo->flags = dev_flags;
1022 	init_usb_anchor(&devinfo->cmd_urbs);
1023 	init_usb_anchor(&devinfo->sense_urbs);
1024 	init_usb_anchor(&devinfo->data_urbs);
1025 	spin_lock_init(&devinfo->lock);
1026 	INIT_WORK(&devinfo->work, uas_do_work);
1027 	INIT_WORK(&devinfo->scan_work, uas_scan_work);
1028 
1029 	result = uas_configure_endpoints(devinfo);
1030 	if (result)
1031 		goto set_alt0;
1032 
1033 	/*
1034 	 * 1 tag is reserved for untagged commands +
1035 	 * 1 tag to avoid off by one errors in some bridge firmwares
1036 	 */
1037 	shost->can_queue = devinfo->qdepth - 2;
1038 
1039 	usb_set_intfdata(intf, shost);
1040 	result = scsi_add_host(shost, &intf->dev);
1041 	if (result)
1042 		goto free_streams;
1043 
1044 	/* Submit the delayed_work for SCSI-device scanning */
1045 	schedule_work(&devinfo->scan_work);
1046 
1047 	return result;
1048 
1049 free_streams:
1050 	uas_free_streams(devinfo);
1051 	usb_set_intfdata(intf, NULL);
1052 set_alt0:
1053 	usb_set_interface(udev, intf->altsetting[0].desc.bInterfaceNumber, 0);
1054 	if (shost)
1055 		scsi_host_put(shost);
1056 	return result;
1057 }
1058 
1059 static int uas_cmnd_list_empty(struct uas_dev_info *devinfo)
1060 {
1061 	unsigned long flags;
1062 	int i, r = 1;
1063 
1064 	spin_lock_irqsave(&devinfo->lock, flags);
1065 
1066 	for (i = 0; i < devinfo->qdepth; i++) {
1067 		if (devinfo->cmnd[i]) {
1068 			r = 0; /* Not empty */
1069 			break;
1070 		}
1071 	}
1072 
1073 	spin_unlock_irqrestore(&devinfo->lock, flags);
1074 
1075 	return r;
1076 }
1077 
1078 /*
1079  * Wait for any pending cmnds to complete, on usb-2 sense_urbs may temporarily
1080  * get empty while there still is more work to do due to sense-urbs completing
1081  * with a READ/WRITE_READY iu code, so keep waiting until the list gets empty.
1082  */
1083 static int uas_wait_for_pending_cmnds(struct uas_dev_info *devinfo)
1084 {
1085 	unsigned long start_time;
1086 	int r;
1087 
1088 	start_time = jiffies;
1089 	do {
1090 		flush_work(&devinfo->work);
1091 
1092 		r = usb_wait_anchor_empty_timeout(&devinfo->sense_urbs, 5000);
1093 		if (r == 0)
1094 			return -ETIME;
1095 
1096 		r = usb_wait_anchor_empty_timeout(&devinfo->data_urbs, 500);
1097 		if (r == 0)
1098 			return -ETIME;
1099 
1100 		if (time_after(jiffies, start_time + 5 * HZ))
1101 			return -ETIME;
1102 	} while (!uas_cmnd_list_empty(devinfo));
1103 
1104 	return 0;
1105 }
1106 
1107 static int uas_pre_reset(struct usb_interface *intf)
1108 {
1109 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1110 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1111 	unsigned long flags;
1112 
1113 	if (devinfo->shutdown)
1114 		return 0;
1115 
1116 	/* Block new requests */
1117 	spin_lock_irqsave(shost->host_lock, flags);
1118 	scsi_block_requests(shost);
1119 	spin_unlock_irqrestore(shost->host_lock, flags);
1120 
1121 	if (uas_wait_for_pending_cmnds(devinfo) != 0) {
1122 		shost_printk(KERN_ERR, shost, "%s: timed out\n", __func__);
1123 		scsi_unblock_requests(shost);
1124 		return 1;
1125 	}
1126 
1127 	uas_free_streams(devinfo);
1128 
1129 	return 0;
1130 }
1131 
1132 static int uas_post_reset(struct usb_interface *intf)
1133 {
1134 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1135 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1136 	unsigned long flags;
1137 	int err;
1138 
1139 	if (devinfo->shutdown)
1140 		return 0;
1141 
1142 	err = uas_configure_endpoints(devinfo);
1143 	if (err && err != -ENODEV)
1144 		shost_printk(KERN_ERR, shost,
1145 			     "%s: alloc streams error %d after reset",
1146 			     __func__, err);
1147 
1148 	/* we must unblock the host in every case lest we deadlock */
1149 	spin_lock_irqsave(shost->host_lock, flags);
1150 	scsi_report_bus_reset(shost, 0);
1151 	spin_unlock_irqrestore(shost->host_lock, flags);
1152 
1153 	scsi_unblock_requests(shost);
1154 
1155 	return err ? 1 : 0;
1156 }
1157 
1158 static int uas_suspend(struct usb_interface *intf, pm_message_t message)
1159 {
1160 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1161 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1162 
1163 	if (uas_wait_for_pending_cmnds(devinfo) != 0) {
1164 		shost_printk(KERN_ERR, shost, "%s: timed out\n", __func__);
1165 		return -ETIME;
1166 	}
1167 
1168 	return 0;
1169 }
1170 
1171 static int uas_resume(struct usb_interface *intf)
1172 {
1173 	return 0;
1174 }
1175 
1176 static int uas_reset_resume(struct usb_interface *intf)
1177 {
1178 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1179 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1180 	unsigned long flags;
1181 	int err;
1182 
1183 	err = uas_configure_endpoints(devinfo);
1184 	if (err) {
1185 		shost_printk(KERN_ERR, shost,
1186 			     "%s: alloc streams error %d after reset",
1187 			     __func__, err);
1188 		return -EIO;
1189 	}
1190 
1191 	spin_lock_irqsave(shost->host_lock, flags);
1192 	scsi_report_bus_reset(shost, 0);
1193 	spin_unlock_irqrestore(shost->host_lock, flags);
1194 
1195 	return 0;
1196 }
1197 
1198 static void uas_disconnect(struct usb_interface *intf)
1199 {
1200 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1201 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1202 	unsigned long flags;
1203 
1204 	spin_lock_irqsave(&devinfo->lock, flags);
1205 	devinfo->resetting = 1;
1206 	spin_unlock_irqrestore(&devinfo->lock, flags);
1207 
1208 	cancel_work_sync(&devinfo->work);
1209 	usb_kill_anchored_urbs(&devinfo->cmd_urbs);
1210 	usb_kill_anchored_urbs(&devinfo->sense_urbs);
1211 	usb_kill_anchored_urbs(&devinfo->data_urbs);
1212 	uas_zap_pending(devinfo, DID_NO_CONNECT);
1213 
1214 	/*
1215 	 * Prevent SCSI scanning (if it hasn't started yet)
1216 	 * or wait for the SCSI-scanning routine to stop.
1217 	 */
1218 	cancel_work_sync(&devinfo->scan_work);
1219 
1220 	scsi_remove_host(shost);
1221 	uas_free_streams(devinfo);
1222 	scsi_host_put(shost);
1223 }
1224 
1225 /*
1226  * Put the device back in usb-storage mode on shutdown, as some BIOS-es
1227  * hang on reboot when the device is still in uas mode. Note the reset is
1228  * necessary as some devices won't revert to usb-storage mode without it.
1229  */
1230 static void uas_shutdown(struct device *dev)
1231 {
1232 	struct usb_interface *intf = to_usb_interface(dev);
1233 	struct usb_device *udev = interface_to_usbdev(intf);
1234 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1235 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1236 
1237 	if (system_state != SYSTEM_RESTART)
1238 		return;
1239 
1240 	devinfo->shutdown = 1;
1241 	uas_free_streams(devinfo);
1242 	usb_set_interface(udev, intf->altsetting[0].desc.bInterfaceNumber, 0);
1243 	usb_reset_device(udev);
1244 }
1245 
1246 static struct usb_driver uas_driver = {
1247 	.name = "uas",
1248 	.probe = uas_probe,
1249 	.disconnect = uas_disconnect,
1250 	.pre_reset = uas_pre_reset,
1251 	.post_reset = uas_post_reset,
1252 	.suspend = uas_suspend,
1253 	.resume = uas_resume,
1254 	.reset_resume = uas_reset_resume,
1255 	.drvwrap.driver.shutdown = uas_shutdown,
1256 	.id_table = uas_usb_ids,
1257 };
1258 
1259 static int __init uas_init(void)
1260 {
1261 	int rv;
1262 
1263 	workqueue = alloc_workqueue("uas", WQ_MEM_RECLAIM, 0);
1264 	if (!workqueue)
1265 		return -ENOMEM;
1266 
1267 	rv = usb_register(&uas_driver);
1268 	if (rv) {
1269 		destroy_workqueue(workqueue);
1270 		return -ENOMEM;
1271 	}
1272 
1273 	return 0;
1274 }
1275 
1276 static void __exit uas_exit(void)
1277 {
1278 	usb_deregister(&uas_driver);
1279 	destroy_workqueue(workqueue);
1280 }
1281 
1282 module_init(uas_init);
1283 module_exit(uas_exit);
1284 
1285 MODULE_LICENSE("GPL");
1286 MODULE_IMPORT_NS(USB_STORAGE);
1287 MODULE_AUTHOR(
1288 	"Hans de Goede <hdegoede@redhat.com>, Matthew Wilcox and Sarah Sharp");
1289