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
34struct 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 u64 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
51enum {
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 */
67struct 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 */
76static int uas_submit_urbs(struct scsi_cmnd *cmnd,
77 struct uas_dev_info *devinfo);
78static void uas_do_work(struct work_struct *work);
79static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller);
80static void uas_free_streams(struct uas_dev_info *devinfo);
81static 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 */
95static struct workqueue_struct *workqueue;
96
97static 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(cmd: cmnd);
117
118 if (!(cmdinfo->state & IS_IN_WORK_LIST))
119 continue;
120
121 err = uas_submit_urbs(cmnd, devinfo: cmnd->device->hostdata);
122 if (!err)
123 cmdinfo->state &= ~IS_IN_WORK_LIST;
124 else
125 queue_work(wq: workqueue, work: &devinfo->work);
126 }
127out:
128 spin_unlock_irqrestore(lock: &devinfo->lock, flags);
129}
130
131static 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(intf: 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
142static void uas_add_work(struct scsi_cmnd *cmnd)
143{
144 struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmd: 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(wq: workqueue, work: &devinfo->work);
150}
151
152static 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(cmd: cmnd);
166 uas_log_cmd_state(cmnd, prefix: __func__, status: 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, caller: __func__);
171 WARN_ON(err != 0);
172 }
173 spin_unlock_irqrestore(lock: &devinfo->lock, flags);
174}
175
176static 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(p: &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
199static 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(cmd: 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
225static 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(cmd: cmnd);
233
234 if (cmdinfo->state & SUBMIT_CMD_URB)
235 usb_free_urb(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(urb: cmdinfo->data_in_urb);
240 if (!(cmdinfo->state & DATA_OUT_URB_INFLIGHT))
241 usb_free_urb(urb: cmdinfo->data_out_urb);
242}
243
244static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller)
245{
246 struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmd: 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(cmd: cmnd);
258 return 0;
259}
260
261static void uas_xfer_data(struct urb *urb, struct scsi_cmnd *cmnd,
262 unsigned direction)
263{
264 struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmd: cmnd);
265 int err;
266
267 cmdinfo->state |= direction | SUBMIT_STATUS_URB;
268 err = uas_submit_urbs(cmnd, devinfo: cmnd->device->hostdata);
269 if (err) {
270 uas_add_work(cmnd);
271 }
272}
273
274static 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(cmd: cmnd, status: DID_BAD_TARGET);
281 break;
282 case RC_TMF_SUCCEEDED:
283 set_host_byte(cmd: cmnd, status: DID_OK);
284 break;
285 case RC_TMF_NOT_SUPPORTED:
286 set_host_byte(cmd: cmnd, status: DID_BAD_TARGET);
287 break;
288 default:
289 uas_log_cmd_state(cmnd, prefix: "response iu", status: response_code);
290 set_host_byte(cmd: cmnd, status: DID_ERROR);
291 break;
292 }
293
294 return response_code == RC_TMF_SUCCEEDED;
295}
296
297static 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(p: &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(cmd: cmnd);
331
332 if (!(cmdinfo->state & COMMAND_INFLIGHT)) {
333 uas_log_cmd_state(cmnd, prefix: "unexpected status cmplt", status: 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(urb: cmdinfo->data_in_urb);
343 data_out_urb = usb_get_urb(urb: cmdinfo->data_out_urb);
344 }
345 cmdinfo->state &= ~COMMAND_INFLIGHT;
346 uas_try_complete(cmnd, caller: __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, prefix: "unexpected read rdy", status: 0);
352 break;
353 }
354 uas_xfer_data(urb, cmnd, direction: 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, prefix: "unexpected write rdy", status: 0);
360 break;
361 }
362 uas_xfer_data(urb, cmnd, direction: SUBMIT_DATA_OUT_URB);
363 break;
364 case IU_ID_RESPONSE:
365 cmdinfo->state &= ~COMMAND_INFLIGHT;
366 success = uas_evaluate_response_iu(riu: (struct response_iu *)iu, cmnd);
367 if (!success) {
368 /* Error, cancel data transfers */
369 data_in_urb = usb_get_urb(urb: cmdinfo->data_in_urb);
370 data_out_urb = usb_get_urb(urb: cmdinfo->data_out_urb);
371 }
372 uas_try_complete(cmnd, caller: __func__);
373 break;
374 default:
375 uas_log_cmd_state(cmnd, prefix: "bogus IU", status: iu->iu_id);
376 }
377out:
378 usb_free_urb(urb);
379 spin_unlock_irqrestore(lock: &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(urb: data_in_urb);
384 usb_put_urb(urb: data_in_urb);
385 }
386 if (data_out_urb) {
387 usb_unlink_urb(urb: data_out_urb);
388 usb_put_urb(urb: data_out_urb);
389 }
390}
391
392static void uas_data_cmplt(struct urb *urb)
393{
394 struct scsi_cmnd *cmnd = urb->context;
395 struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmd: 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, prefix: "unexpected data cmplt", status: 0);
417 goto out;
418 }
419
420 if (status) {
421 if (status != -ENOENT && status != -ECONNRESET && status != -ESHUTDOWN)
422 uas_log_cmd_state(cmnd, prefix: "data cmplt err", status);
423 /* error: no data transfered */
424 scsi_set_resid(cmd: cmnd, resid: sdb->length);
425 } else {
426 scsi_set_resid(cmd: cmnd, resid: sdb->length - urb->actual_length);
427 }
428 uas_try_complete(cmnd, caller: __func__);
429out:
430 usb_free_urb(urb);
431 spin_unlock_irqrestore(lock: &devinfo->lock, flags);
432}
433
434static void uas_cmd_cmplt(struct urb *urb)
435{
436 if (urb->status)
437 dev_err(&urb->dev->dev, "cmd cmplt err %d\n", urb->status);
438
439 usb_free_urb(urb);
440}
441
442static struct urb *uas_alloc_data_urb(struct uas_dev_info *devinfo, gfp_t gfp,
443 struct scsi_cmnd *cmnd,
444 enum dma_data_direction dir)
445{
446 struct usb_device *udev = devinfo->udev;
447 struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmd: cmnd);
448 struct urb *urb = usb_alloc_urb(iso_packets: 0, mem_flags: gfp);
449 struct scsi_data_buffer *sdb = &cmnd->sdb;
450 unsigned int pipe = (dir == DMA_FROM_DEVICE)
451 ? devinfo->data_in_pipe : devinfo->data_out_pipe;
452
453 if (!urb)
454 goto out;
455 usb_fill_bulk_urb(urb, dev: udev, pipe, NULL, buffer_length: sdb->length,
456 complete_fn: uas_data_cmplt, context: cmnd);
457 if (devinfo->use_streams)
458 urb->stream_id = cmdinfo->uas_tag;
459 urb->num_sgs = udev->bus->sg_tablesize ? sdb->table.nents : 0;
460 urb->sg = sdb->table.sgl;
461 out:
462 return urb;
463}
464
465static struct urb *uas_alloc_sense_urb(struct uas_dev_info *devinfo, gfp_t gfp,
466 struct scsi_cmnd *cmnd)
467{
468 struct usb_device *udev = devinfo->udev;
469 struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmd: cmnd);
470 struct urb *urb = usb_alloc_urb(iso_packets: 0, mem_flags: gfp);
471 struct sense_iu *iu;
472
473 if (!urb)
474 goto out;
475
476 iu = kzalloc(size: sizeof(*iu), flags: gfp);
477 if (!iu)
478 goto free;
479
480 usb_fill_bulk_urb(urb, dev: udev, pipe: devinfo->status_pipe, transfer_buffer: iu, buffer_length: sizeof(*iu),
481 complete_fn: uas_stat_cmplt, context: cmnd->device->host);
482 if (devinfo->use_streams)
483 urb->stream_id = cmdinfo->uas_tag;
484 urb->transfer_flags |= URB_FREE_BUFFER;
485 out:
486 return urb;
487 free:
488 usb_free_urb(urb);
489 return NULL;
490}
491
492static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
493 struct scsi_cmnd *cmnd)
494{
495 struct usb_device *udev = devinfo->udev;
496 struct scsi_device *sdev = cmnd->device;
497 struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmd: cmnd);
498 struct urb *urb = usb_alloc_urb(iso_packets: 0, mem_flags: gfp);
499 struct command_iu *iu;
500 int len;
501
502 if (!urb)
503 goto out;
504
505 len = cmnd->cmd_len - 16;
506 if (len < 0)
507 len = 0;
508 len = ALIGN(len, 4);
509 iu = kzalloc(size: sizeof(*iu) + len, flags: gfp);
510 if (!iu)
511 goto free;
512
513 iu->iu_id = IU_ID_COMMAND;
514 iu->tag = cpu_to_be16(cmdinfo->uas_tag);
515 iu->prio_attr = UAS_SIMPLE_TAG;
516 iu->len = len;
517 int_to_scsilun(sdev->lun, &iu->lun);
518 memcpy(iu->cdb, cmnd->cmnd, cmnd->cmd_len);
519
520 usb_fill_bulk_urb(urb, dev: udev, pipe: devinfo->cmd_pipe, transfer_buffer: iu, buffer_length: sizeof(*iu) + len,
521 complete_fn: uas_cmd_cmplt, NULL);
522 urb->transfer_flags |= URB_FREE_BUFFER;
523 out:
524 return urb;
525 free:
526 usb_free_urb(urb);
527 return NULL;
528}
529
530/*
531 * Why should I request the Status IU before sending the Command IU? Spec
532 * says to, but also says the device may receive them in any order. Seems
533 * daft to me.
534 */
535
536static struct urb *uas_submit_sense_urb(struct scsi_cmnd *cmnd, gfp_t gfp)
537{
538 struct uas_dev_info *devinfo = cmnd->device->hostdata;
539 struct urb *urb;
540 int err;
541
542 urb = uas_alloc_sense_urb(devinfo, gfp, cmnd);
543 if (!urb)
544 return NULL;
545 usb_anchor_urb(urb, anchor: &devinfo->sense_urbs);
546 err = usb_submit_urb(urb, mem_flags: gfp);
547 if (err) {
548 usb_unanchor_urb(urb);
549 uas_log_cmd_state(cmnd, prefix: "sense submit err", status: err);
550 usb_free_urb(urb);
551 return NULL;
552 }
553 return urb;
554}
555
556static int uas_submit_urbs(struct scsi_cmnd *cmnd,
557 struct uas_dev_info *devinfo)
558{
559 struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmd: cmnd);
560 struct urb *urb;
561 int err;
562
563 lockdep_assert_held(&devinfo->lock);
564 if (cmdinfo->state & SUBMIT_STATUS_URB) {
565 urb = uas_submit_sense_urb(cmnd, GFP_ATOMIC);
566 if (!urb)
567 return SCSI_MLQUEUE_DEVICE_BUSY;
568 cmdinfo->state &= ~SUBMIT_STATUS_URB;
569 }
570
571 if (cmdinfo->state & ALLOC_DATA_IN_URB) {
572 cmdinfo->data_in_urb = uas_alloc_data_urb(devinfo, GFP_ATOMIC,
573 cmnd, dir: DMA_FROM_DEVICE);
574 if (!cmdinfo->data_in_urb)
575 return SCSI_MLQUEUE_DEVICE_BUSY;
576 cmdinfo->state &= ~ALLOC_DATA_IN_URB;
577 }
578
579 if (cmdinfo->state & SUBMIT_DATA_IN_URB) {
580 usb_anchor_urb(urb: cmdinfo->data_in_urb, anchor: &devinfo->data_urbs);
581 err = usb_submit_urb(urb: cmdinfo->data_in_urb, GFP_ATOMIC);
582 if (err) {
583 usb_unanchor_urb(urb: cmdinfo->data_in_urb);
584 uas_log_cmd_state(cmnd, prefix: "data in submit err", status: err);
585 return SCSI_MLQUEUE_DEVICE_BUSY;
586 }
587 cmdinfo->state &= ~SUBMIT_DATA_IN_URB;
588 cmdinfo->state |= DATA_IN_URB_INFLIGHT;
589 }
590
591 if (cmdinfo->state & ALLOC_DATA_OUT_URB) {
592 cmdinfo->data_out_urb = uas_alloc_data_urb(devinfo, GFP_ATOMIC,
593 cmnd, dir: DMA_TO_DEVICE);
594 if (!cmdinfo->data_out_urb)
595 return SCSI_MLQUEUE_DEVICE_BUSY;
596 cmdinfo->state &= ~ALLOC_DATA_OUT_URB;
597 }
598
599 if (cmdinfo->state & SUBMIT_DATA_OUT_URB) {
600 usb_anchor_urb(urb: cmdinfo->data_out_urb, anchor: &devinfo->data_urbs);
601 err = usb_submit_urb(urb: cmdinfo->data_out_urb, GFP_ATOMIC);
602 if (err) {
603 usb_unanchor_urb(urb: cmdinfo->data_out_urb);
604 uas_log_cmd_state(cmnd, prefix: "data out submit err", status: err);
605 return SCSI_MLQUEUE_DEVICE_BUSY;
606 }
607 cmdinfo->state &= ~SUBMIT_DATA_OUT_URB;
608 cmdinfo->state |= DATA_OUT_URB_INFLIGHT;
609 }
610
611 if (cmdinfo->state & ALLOC_CMD_URB) {
612 cmdinfo->cmd_urb = uas_alloc_cmd_urb(devinfo, GFP_ATOMIC, cmnd);
613 if (!cmdinfo->cmd_urb)
614 return SCSI_MLQUEUE_DEVICE_BUSY;
615 cmdinfo->state &= ~ALLOC_CMD_URB;
616 }
617
618 if (cmdinfo->state & SUBMIT_CMD_URB) {
619 usb_anchor_urb(urb: cmdinfo->cmd_urb, anchor: &devinfo->cmd_urbs);
620 err = usb_submit_urb(urb: cmdinfo->cmd_urb, GFP_ATOMIC);
621 if (err) {
622 usb_unanchor_urb(urb: cmdinfo->cmd_urb);
623 uas_log_cmd_state(cmnd, prefix: "cmd submit err", status: err);
624 return SCSI_MLQUEUE_DEVICE_BUSY;
625 }
626 cmdinfo->cmd_urb = NULL;
627 cmdinfo->state &= ~SUBMIT_CMD_URB;
628 cmdinfo->state |= COMMAND_INFLIGHT;
629 }
630
631 return 0;
632}
633
634static int uas_queuecommand_lck(struct scsi_cmnd *cmnd)
635{
636 struct scsi_device *sdev = cmnd->device;
637 struct uas_dev_info *devinfo = sdev->hostdata;
638 struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmd: cmnd);
639 unsigned long flags;
640 int idx, err;
641
642 /* Re-check scsi_block_requests now that we've the host-lock */
643 if (cmnd->device->host->host_self_blocked)
644 return SCSI_MLQUEUE_DEVICE_BUSY;
645
646 if ((devinfo->flags & US_FL_NO_ATA_1X) &&
647 (cmnd->cmnd[0] == ATA_12 || cmnd->cmnd[0] == ATA_16)) {
648 memcpy(cmnd->sense_buffer, usb_stor_sense_invalidCDB,
649 sizeof(usb_stor_sense_invalidCDB));
650 cmnd->result = SAM_STAT_CHECK_CONDITION;
651 scsi_done(cmd: cmnd);
652 return 0;
653 }
654
655 spin_lock_irqsave(&devinfo->lock, flags);
656
657 if (devinfo->resetting) {
658 set_host_byte(cmd: cmnd, status: DID_ERROR);
659 scsi_done(cmd: cmnd);
660 goto zombie;
661 }
662
663 /* Find a free uas-tag */
664 for (idx = 0; idx < devinfo->qdepth; idx++) {
665 if (!devinfo->cmnd[idx])
666 break;
667 }
668 if (idx == devinfo->qdepth) {
669 spin_unlock_irqrestore(lock: &devinfo->lock, flags);
670 return SCSI_MLQUEUE_DEVICE_BUSY;
671 }
672
673 memset(cmdinfo, 0, sizeof(*cmdinfo));
674 cmdinfo->uas_tag = idx + 1; /* uas-tag == usb-stream-id, so 1 based */
675 cmdinfo->state = SUBMIT_STATUS_URB | ALLOC_CMD_URB | SUBMIT_CMD_URB;
676
677 switch (cmnd->sc_data_direction) {
678 case DMA_FROM_DEVICE:
679 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
680 break;
681 case DMA_BIDIRECTIONAL:
682 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
683 fallthrough;
684 case DMA_TO_DEVICE:
685 cmdinfo->state |= ALLOC_DATA_OUT_URB | SUBMIT_DATA_OUT_URB;
686 break;
687 case DMA_NONE:
688 break;
689 }
690
691 if (!devinfo->use_streams)
692 cmdinfo->state &= ~(SUBMIT_DATA_IN_URB | SUBMIT_DATA_OUT_URB);
693
694 err = uas_submit_urbs(cmnd, devinfo);
695 /*
696 * in case of fatal errors the SCSI layer is peculiar
697 * a command that has finished is a success for the purpose
698 * of queueing, no matter how fatal the error
699 */
700 if (err == -ENODEV) {
701 set_host_byte(cmd: cmnd, status: DID_ERROR);
702 scsi_done(cmd: cmnd);
703 goto zombie;
704 }
705 if (err) {
706 /* If we did nothing, give up now */
707 if (cmdinfo->state & SUBMIT_STATUS_URB) {
708 spin_unlock_irqrestore(lock: &devinfo->lock, flags);
709 return SCSI_MLQUEUE_DEVICE_BUSY;
710 }
711 uas_add_work(cmnd);
712 }
713
714 devinfo->cmnd[idx] = cmnd;
715zombie:
716 spin_unlock_irqrestore(lock: &devinfo->lock, flags);
717 return 0;
718}
719
720static DEF_SCSI_QCMD(uas_queuecommand)
721
722/*
723 * For now we do not support actually sending an abort to the device, so
724 * this eh always fails. Still we must define it to make sure that we've
725 * dropped all references to the cmnd in question once this function exits.
726 */
727static int uas_eh_abort_handler(struct scsi_cmnd *cmnd)
728{
729 struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmd: cmnd);
730 struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
731 struct urb *data_in_urb = NULL;
732 struct urb *data_out_urb = NULL;
733 unsigned long flags;
734
735 spin_lock_irqsave(&devinfo->lock, flags);
736
737 uas_log_cmd_state(cmnd, prefix: __func__, status: 0);
738
739 /* Ensure that try_complete does not call scsi_done */
740 cmdinfo->state |= COMMAND_ABORTED;
741
742 /* Drop all refs to this cmnd, kill data urbs to break their ref */
743 devinfo->cmnd[cmdinfo->uas_tag - 1] = NULL;
744 if (cmdinfo->state & DATA_IN_URB_INFLIGHT)
745 data_in_urb = usb_get_urb(urb: cmdinfo->data_in_urb);
746 if (cmdinfo->state & DATA_OUT_URB_INFLIGHT)
747 data_out_urb = usb_get_urb(urb: cmdinfo->data_out_urb);
748
749 uas_free_unsubmitted_urbs(cmnd);
750
751 spin_unlock_irqrestore(lock: &devinfo->lock, flags);
752
753 if (data_in_urb) {
754 usb_kill_urb(urb: data_in_urb);
755 usb_put_urb(urb: data_in_urb);
756 }
757 if (data_out_urb) {
758 usb_kill_urb(urb: data_out_urb);
759 usb_put_urb(urb: data_out_urb);
760 }
761
762 return FAILED;
763}
764
765static int uas_eh_device_reset_handler(struct scsi_cmnd *cmnd)
766{
767 struct scsi_device *sdev = cmnd->device;
768 struct uas_dev_info *devinfo = sdev->hostdata;
769 struct usb_device *udev = devinfo->udev;
770 unsigned long flags;
771 int err;
772
773 err = usb_lock_device_for_reset(udev, iface: devinfo->intf);
774 if (err) {
775 shost_printk(KERN_ERR, sdev->host,
776 "%s FAILED to get lock err %d\n", __func__, err);
777 return FAILED;
778 }
779
780 shost_printk(KERN_INFO, sdev->host, "%s start\n", __func__);
781
782 spin_lock_irqsave(&devinfo->lock, flags);
783 devinfo->resetting = 1;
784 spin_unlock_irqrestore(lock: &devinfo->lock, flags);
785
786 usb_kill_anchored_urbs(anchor: &devinfo->cmd_urbs);
787 usb_kill_anchored_urbs(anchor: &devinfo->sense_urbs);
788 usb_kill_anchored_urbs(anchor: &devinfo->data_urbs);
789 uas_zap_pending(devinfo, result: DID_RESET);
790
791 err = usb_reset_device(dev: udev);
792
793 spin_lock_irqsave(&devinfo->lock, flags);
794 devinfo->resetting = 0;
795 spin_unlock_irqrestore(lock: &devinfo->lock, flags);
796
797 usb_unlock_device(udev);
798
799 if (err) {
800 shost_printk(KERN_INFO, sdev->host, "%s FAILED err %d\n",
801 __func__, err);
802 return FAILED;
803 }
804
805 shost_printk(KERN_INFO, sdev->host, "%s success\n", __func__);
806 return SUCCESS;
807}
808
809static int uas_target_alloc(struct scsi_target *starget)
810{
811 struct uas_dev_info *devinfo = (struct uas_dev_info *)
812 dev_to_shost(dev: starget->dev.parent)->hostdata;
813
814 if (devinfo->flags & US_FL_NO_REPORT_LUNS)
815 starget->no_report_luns = 1;
816
817 return 0;
818}
819
820static int uas_slave_alloc(struct scsi_device *sdev)
821{
822 struct uas_dev_info *devinfo =
823 (struct uas_dev_info *)sdev->host->hostdata;
824
825 sdev->hostdata = devinfo;
826
827 /*
828 * The protocol has no requirements on alignment in the strict sense.
829 * Controllers may or may not have alignment restrictions.
830 * As this is not exported, we use an extremely conservative guess.
831 */
832 blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
833
834 if (devinfo->flags & US_FL_MAX_SECTORS_64)
835 blk_queue_max_hw_sectors(sdev->request_queue, 64);
836 else if (devinfo->flags & US_FL_MAX_SECTORS_240)
837 blk_queue_max_hw_sectors(sdev->request_queue, 240);
838
839 return 0;
840}
841
842static int uas_slave_configure(struct scsi_device *sdev)
843{
844 struct uas_dev_info *devinfo = sdev->hostdata;
845
846 if (devinfo->flags & US_FL_NO_REPORT_OPCODES)
847 sdev->no_report_opcodes = 1;
848
849 /* A few buggy USB-ATA bridges don't understand FUA */
850 if (devinfo->flags & US_FL_BROKEN_FUA)
851 sdev->broken_fua = 1;
852
853 /* UAS also needs to support FL_ALWAYS_SYNC */
854 if (devinfo->flags & US_FL_ALWAYS_SYNC) {
855 sdev->skip_ms_page_3f = 1;
856 sdev->skip_ms_page_8 = 1;
857 sdev->wce_default_on = 1;
858 }
859
860 /* Some disks cannot handle READ_CAPACITY_16 */
861 if (devinfo->flags & US_FL_NO_READ_CAPACITY_16)
862 sdev->no_read_capacity_16 = 1;
863
864 /* Some disks cannot handle WRITE_SAME */
865 if (devinfo->flags & US_FL_NO_SAME)
866 sdev->no_write_same = 1;
867 /*
868 * Some disks return the total number of blocks in response
869 * to READ CAPACITY rather than the highest block number.
870 * If this device makes that mistake, tell the sd driver.
871 */
872 if (devinfo->flags & US_FL_FIX_CAPACITY)
873 sdev->fix_capacity = 1;
874
875 /*
876 * in some cases we have to guess
877 */
878 if (devinfo->flags & US_FL_CAPACITY_HEURISTICS)
879 sdev->guess_capacity = 1;
880
881 /*
882 * Some devices don't like MODE SENSE with page=0x3f,
883 * which is the command used for checking if a device
884 * is write-protected. Now that we tell the sd driver
885 * to do a 192-byte transfer with this command the
886 * majority of devices work fine, but a few still can't
887 * handle it. The sd driver will simply assume those
888 * devices are write-enabled.
889 */
890 if (devinfo->flags & US_FL_NO_WP_DETECT)
891 sdev->skip_ms_page_3f = 1;
892
893 scsi_change_queue_depth(sdev, devinfo->qdepth - 2);
894 return 0;
895}
896
897static const struct scsi_host_template uas_host_template = {
898 .module = THIS_MODULE,
899 .name = "uas",
900 .queuecommand = uas_queuecommand,
901 .target_alloc = uas_target_alloc,
902 .slave_alloc = uas_slave_alloc,
903 .slave_configure = uas_slave_configure,
904 .eh_abort_handler = uas_eh_abort_handler,
905 .eh_device_reset_handler = uas_eh_device_reset_handler,
906 .this_id = -1,
907 .skip_settle_delay = 1,
908 .dma_boundary = PAGE_SIZE - 1,
909 .cmd_size = sizeof(struct uas_cmd_info),
910};
911
912#define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
913 vendorName, productName, useProtocol, useTransport, \
914 initFunction, flags) \
915{ USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
916 .driver_info = (flags) }
917
918static struct usb_device_id uas_usb_ids[] = {
919# include "unusual_uas.h"
920 { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_BULK) },
921 { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_UAS) },
922 { }
923};
924MODULE_DEVICE_TABLE(usb, uas_usb_ids);
925
926#undef UNUSUAL_DEV
927
928static int uas_switch_interface(struct usb_device *udev,
929 struct usb_interface *intf)
930{
931 struct usb_host_interface *alt;
932
933 alt = uas_find_uas_alt_setting(intf);
934 if (!alt)
935 return -ENODEV;
936
937 return usb_set_interface(dev: udev, ifnum: alt->desc.bInterfaceNumber,
938 alternate: alt->desc.bAlternateSetting);
939}
940
941static int uas_configure_endpoints(struct uas_dev_info *devinfo)
942{
943 struct usb_host_endpoint *eps[4] = { };
944 struct usb_device *udev = devinfo->udev;
945 int r;
946
947 r = uas_find_endpoints(alt: devinfo->intf->cur_altsetting, eps);
948 if (r)
949 return r;
950
951 devinfo->cmd_pipe = usb_sndbulkpipe(udev,
952 usb_endpoint_num(&eps[0]->desc));
953 devinfo->status_pipe = usb_rcvbulkpipe(udev,
954 usb_endpoint_num(&eps[1]->desc));
955 devinfo->data_in_pipe = usb_rcvbulkpipe(udev,
956 usb_endpoint_num(&eps[2]->desc));
957 devinfo->data_out_pipe = usb_sndbulkpipe(udev,
958 usb_endpoint_num(&eps[3]->desc));
959
960 if (udev->speed < USB_SPEED_SUPER) {
961 devinfo->qdepth = 32;
962 devinfo->use_streams = 0;
963 } else {
964 devinfo->qdepth = usb_alloc_streams(interface: devinfo->intf, eps: eps + 1,
965 num_eps: 3, MAX_CMNDS, GFP_NOIO);
966 if (devinfo->qdepth < 0)
967 return devinfo->qdepth;
968 devinfo->use_streams = 1;
969 }
970
971 return 0;
972}
973
974static void uas_free_streams(struct uas_dev_info *devinfo)
975{
976 struct usb_device *udev = devinfo->udev;
977 struct usb_host_endpoint *eps[3];
978
979 eps[0] = usb_pipe_endpoint(dev: udev, pipe: devinfo->status_pipe);
980 eps[1] = usb_pipe_endpoint(dev: udev, pipe: devinfo->data_in_pipe);
981 eps[2] = usb_pipe_endpoint(dev: udev, pipe: devinfo->data_out_pipe);
982 usb_free_streams(interface: devinfo->intf, eps, num_eps: 3, GFP_NOIO);
983}
984
985static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id)
986{
987 int result = -ENOMEM;
988 struct Scsi_Host *shost = NULL;
989 struct uas_dev_info *devinfo;
990 struct usb_device *udev = interface_to_usbdev(intf);
991 u64 dev_flags;
992
993 if (!uas_use_uas_driver(intf, id, flags_ret: &dev_flags))
994 return -ENODEV;
995
996 if (uas_switch_interface(udev, intf))
997 return -ENODEV;
998
999 shost = scsi_host_alloc(&uas_host_template,
1000 sizeof(struct uas_dev_info));
1001 if (!shost)
1002 goto set_alt0;
1003
1004 shost->max_cmd_len = 16 + 252;
1005 shost->max_id = 1;
1006 shost->max_lun = 256;
1007 shost->max_channel = 0;
1008 shost->sg_tablesize = udev->bus->sg_tablesize;
1009
1010 devinfo = (struct uas_dev_info *)shost->hostdata;
1011 devinfo->intf = intf;
1012 devinfo->udev = udev;
1013 devinfo->resetting = 0;
1014 devinfo->shutdown = 0;
1015 devinfo->flags = dev_flags;
1016 init_usb_anchor(anchor: &devinfo->cmd_urbs);
1017 init_usb_anchor(anchor: &devinfo->sense_urbs);
1018 init_usb_anchor(anchor: &devinfo->data_urbs);
1019 spin_lock_init(&devinfo->lock);
1020 INIT_WORK(&devinfo->work, uas_do_work);
1021 INIT_WORK(&devinfo->scan_work, uas_scan_work);
1022
1023 result = uas_configure_endpoints(devinfo);
1024 if (result)
1025 goto set_alt0;
1026
1027 /*
1028 * 1 tag is reserved for untagged commands +
1029 * 1 tag to avoid off by one errors in some bridge firmwares
1030 */
1031 shost->can_queue = devinfo->qdepth - 2;
1032
1033 usb_set_intfdata(intf, data: shost);
1034 result = scsi_add_host(host: shost, dev: &intf->dev);
1035 if (result)
1036 goto free_streams;
1037
1038 /* Submit the delayed_work for SCSI-device scanning */
1039 schedule_work(work: &devinfo->scan_work);
1040
1041 return result;
1042
1043free_streams:
1044 uas_free_streams(devinfo);
1045 usb_set_intfdata(intf, NULL);
1046set_alt0:
1047 usb_set_interface(dev: udev, ifnum: intf->altsetting[0].desc.bInterfaceNumber, alternate: 0);
1048 if (shost)
1049 scsi_host_put(t: shost);
1050 return result;
1051}
1052
1053static int uas_cmnd_list_empty(struct uas_dev_info *devinfo)
1054{
1055 unsigned long flags;
1056 int i, r = 1;
1057
1058 spin_lock_irqsave(&devinfo->lock, flags);
1059
1060 for (i = 0; i < devinfo->qdepth; i++) {
1061 if (devinfo->cmnd[i]) {
1062 r = 0; /* Not empty */
1063 break;
1064 }
1065 }
1066
1067 spin_unlock_irqrestore(lock: &devinfo->lock, flags);
1068
1069 return r;
1070}
1071
1072/*
1073 * Wait for any pending cmnds to complete, on usb-2 sense_urbs may temporarily
1074 * get empty while there still is more work to do due to sense-urbs completing
1075 * with a READ/WRITE_READY iu code, so keep waiting until the list gets empty.
1076 */
1077static int uas_wait_for_pending_cmnds(struct uas_dev_info *devinfo)
1078{
1079 unsigned long start_time;
1080 int r;
1081
1082 start_time = jiffies;
1083 do {
1084 flush_work(work: &devinfo->work);
1085
1086 r = usb_wait_anchor_empty_timeout(anchor: &devinfo->sense_urbs, timeout: 5000);
1087 if (r == 0)
1088 return -ETIME;
1089
1090 r = usb_wait_anchor_empty_timeout(anchor: &devinfo->data_urbs, timeout: 500);
1091 if (r == 0)
1092 return -ETIME;
1093
1094 if (time_after(jiffies, start_time + 5 * HZ))
1095 return -ETIME;
1096 } while (!uas_cmnd_list_empty(devinfo));
1097
1098 return 0;
1099}
1100
1101static int uas_pre_reset(struct usb_interface *intf)
1102{
1103 struct Scsi_Host *shost = usb_get_intfdata(intf);
1104 struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1105 unsigned long flags;
1106
1107 if (devinfo->shutdown)
1108 return 0;
1109
1110 /* Block new requests */
1111 spin_lock_irqsave(shost->host_lock, flags);
1112 scsi_block_requests(shost);
1113 spin_unlock_irqrestore(lock: shost->host_lock, flags);
1114
1115 if (uas_wait_for_pending_cmnds(devinfo) != 0) {
1116 shost_printk(KERN_ERR, shost, "%s: timed out\n", __func__);
1117 scsi_unblock_requests(shost);
1118 return 1;
1119 }
1120
1121 uas_free_streams(devinfo);
1122
1123 return 0;
1124}
1125
1126static int uas_post_reset(struct usb_interface *intf)
1127{
1128 struct Scsi_Host *shost = usb_get_intfdata(intf);
1129 struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1130 unsigned long flags;
1131 int err;
1132
1133 if (devinfo->shutdown)
1134 return 0;
1135
1136 err = uas_configure_endpoints(devinfo);
1137 if (err && err != -ENODEV)
1138 shost_printk(KERN_ERR, shost,
1139 "%s: alloc streams error %d after reset",
1140 __func__, err);
1141
1142 /* we must unblock the host in every case lest we deadlock */
1143 spin_lock_irqsave(shost->host_lock, flags);
1144 scsi_report_bus_reset(shost, 0);
1145 spin_unlock_irqrestore(lock: shost->host_lock, flags);
1146
1147 scsi_unblock_requests(shost);
1148
1149 return err ? 1 : 0;
1150}
1151
1152static int uas_suspend(struct usb_interface *intf, pm_message_t message)
1153{
1154 struct Scsi_Host *shost = usb_get_intfdata(intf);
1155 struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1156
1157 if (uas_wait_for_pending_cmnds(devinfo) != 0) {
1158 shost_printk(KERN_ERR, shost, "%s: timed out\n", __func__);
1159 return -ETIME;
1160 }
1161
1162 return 0;
1163}
1164
1165static int uas_resume(struct usb_interface *intf)
1166{
1167 return 0;
1168}
1169
1170static int uas_reset_resume(struct usb_interface *intf)
1171{
1172 struct Scsi_Host *shost = usb_get_intfdata(intf);
1173 struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1174 unsigned long flags;
1175 int err;
1176
1177 err = uas_configure_endpoints(devinfo);
1178 if (err) {
1179 shost_printk(KERN_ERR, shost,
1180 "%s: alloc streams error %d after reset",
1181 __func__, err);
1182 return -EIO;
1183 }
1184
1185 spin_lock_irqsave(shost->host_lock, flags);
1186 scsi_report_bus_reset(shost, 0);
1187 spin_unlock_irqrestore(lock: shost->host_lock, flags);
1188
1189 return 0;
1190}
1191
1192static void uas_disconnect(struct usb_interface *intf)
1193{
1194 struct Scsi_Host *shost = usb_get_intfdata(intf);
1195 struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1196 unsigned long flags;
1197
1198 spin_lock_irqsave(&devinfo->lock, flags);
1199 devinfo->resetting = 1;
1200 spin_unlock_irqrestore(lock: &devinfo->lock, flags);
1201
1202 cancel_work_sync(work: &devinfo->work);
1203 usb_kill_anchored_urbs(anchor: &devinfo->cmd_urbs);
1204 usb_kill_anchored_urbs(anchor: &devinfo->sense_urbs);
1205 usb_kill_anchored_urbs(anchor: &devinfo->data_urbs);
1206 uas_zap_pending(devinfo, result: DID_NO_CONNECT);
1207
1208 /*
1209 * Prevent SCSI scanning (if it hasn't started yet)
1210 * or wait for the SCSI-scanning routine to stop.
1211 */
1212 cancel_work_sync(work: &devinfo->scan_work);
1213
1214 scsi_remove_host(shost);
1215 uas_free_streams(devinfo);
1216 scsi_host_put(t: shost);
1217}
1218
1219/*
1220 * Put the device back in usb-storage mode on shutdown, as some BIOS-es
1221 * hang on reboot when the device is still in uas mode. Note the reset is
1222 * necessary as some devices won't revert to usb-storage mode without it.
1223 */
1224static void uas_shutdown(struct device *dev)
1225{
1226 struct usb_interface *intf = to_usb_interface(dev);
1227 struct usb_device *udev = interface_to_usbdev(intf);
1228 struct Scsi_Host *shost = usb_get_intfdata(intf);
1229 struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1230
1231 if (system_state != SYSTEM_RESTART)
1232 return;
1233
1234 devinfo->shutdown = 1;
1235 uas_free_streams(devinfo);
1236 usb_set_interface(dev: udev, ifnum: intf->altsetting[0].desc.bInterfaceNumber, alternate: 0);
1237 usb_reset_device(dev: udev);
1238}
1239
1240static struct usb_driver uas_driver = {
1241 .name = "uas",
1242 .probe = uas_probe,
1243 .disconnect = uas_disconnect,
1244 .pre_reset = uas_pre_reset,
1245 .post_reset = uas_post_reset,
1246 .suspend = uas_suspend,
1247 .resume = uas_resume,
1248 .reset_resume = uas_reset_resume,
1249 .drvwrap.driver.shutdown = uas_shutdown,
1250 .id_table = uas_usb_ids,
1251};
1252
1253static int __init uas_init(void)
1254{
1255 int rv;
1256
1257 workqueue = alloc_workqueue(fmt: "uas", flags: WQ_MEM_RECLAIM, max_active: 0);
1258 if (!workqueue)
1259 return -ENOMEM;
1260
1261 rv = usb_register(&uas_driver);
1262 if (rv) {
1263 destroy_workqueue(wq: workqueue);
1264 return -ENOMEM;
1265 }
1266
1267 return 0;
1268}
1269
1270static void __exit uas_exit(void)
1271{
1272 usb_deregister(&uas_driver);
1273 destroy_workqueue(wq: workqueue);
1274}
1275
1276module_init(uas_init);
1277module_exit(uas_exit);
1278
1279MODULE_LICENSE("GPL");
1280MODULE_IMPORT_NS(USB_STORAGE);
1281MODULE_AUTHOR(
1282 "Hans de Goede <hdegoede@redhat.com>, Matthew Wilcox and Sarah Sharp");
1283

source code of linux/drivers/usb/storage/uas.c