xref: /openbmc/linux/drivers/usb/storage/uas.c (revision 5a86bf34)
1 /*
2  * USB Attached SCSI
3  * Note that this is not the same as the USB Mass Storage driver
4  *
5  * Copyright Matthew Wilcox for Intel Corp, 2010
6  * Copyright Sarah Sharp for Intel Corp, 2010
7  *
8  * Distributed under the terms of the GNU GPL, version two.
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/hcd.h>
17 #include <linux/usb/storage.h>
18 #include <linux/usb/uas.h>
19 
20 #include <scsi/scsi.h>
21 #include <scsi/scsi_dbg.h>
22 #include <scsi/scsi_cmnd.h>
23 #include <scsi/scsi_device.h>
24 #include <scsi/scsi_host.h>
25 #include <scsi/scsi_tcq.h>
26 
27 /*
28  * The r00-r01c specs define this version of the SENSE IU data structure.
29  * It's still in use by several different firmware releases.
30  */
31 struct sense_iu_old {
32 	__u8 iu_id;
33 	__u8 rsvd1;
34 	__be16 tag;
35 	__be16 len;
36 	__u8 status;
37 	__u8 service_response;
38 	__u8 sense[SCSI_SENSE_BUFFERSIZE];
39 };
40 
41 struct uas_dev_info {
42 	struct usb_interface *intf;
43 	struct usb_device *udev;
44 	struct usb_anchor cmd_urbs;
45 	struct usb_anchor sense_urbs;
46 	struct usb_anchor data_urbs;
47 	int qdepth, resetting;
48 	struct response_ui response;
49 	unsigned cmd_pipe, status_pipe, data_in_pipe, data_out_pipe;
50 	unsigned use_streams:1;
51 	unsigned uas_sense_old:1;
52 	struct scsi_cmnd *cmnd;
53 	spinlock_t lock;
54 };
55 
56 enum {
57 	SUBMIT_STATUS_URB	= (1 << 1),
58 	ALLOC_DATA_IN_URB	= (1 << 2),
59 	SUBMIT_DATA_IN_URB	= (1 << 3),
60 	ALLOC_DATA_OUT_URB	= (1 << 4),
61 	SUBMIT_DATA_OUT_URB	= (1 << 5),
62 	ALLOC_CMD_URB		= (1 << 6),
63 	SUBMIT_CMD_URB		= (1 << 7),
64 	COMMAND_INFLIGHT        = (1 << 8),
65 	DATA_IN_URB_INFLIGHT    = (1 << 9),
66 	DATA_OUT_URB_INFLIGHT   = (1 << 10),
67 	COMMAND_COMPLETED       = (1 << 11),
68 	COMMAND_ABORTED         = (1 << 12),
69 	UNLINK_DATA_URBS        = (1 << 13),
70 	IS_IN_WORK_LIST         = (1 << 14),
71 };
72 
73 /* Overrides scsi_pointer */
74 struct uas_cmd_info {
75 	unsigned int state;
76 	unsigned int stream;
77 	struct urb *cmd_urb;
78 	struct urb *data_in_urb;
79 	struct urb *data_out_urb;
80 	struct list_head list;
81 };
82 
83 /* I hate forward declarations, but I actually have a loop */
84 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
85 				struct uas_dev_info *devinfo, gfp_t gfp);
86 static void uas_do_work(struct work_struct *work);
87 static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller);
88 
89 static DECLARE_WORK(uas_work, uas_do_work);
90 static DEFINE_SPINLOCK(uas_work_lock);
91 static LIST_HEAD(uas_work_list);
92 
93 static void uas_unlink_data_urbs(struct uas_dev_info *devinfo,
94 				 struct uas_cmd_info *cmdinfo)
95 {
96 	unsigned long flags;
97 
98 	/*
99 	 * The UNLINK_DATA_URBS flag makes sure uas_try_complete
100 	 * (called by urb completion) doesn't release cmdinfo
101 	 * underneath us.
102 	 */
103 	spin_lock_irqsave(&devinfo->lock, flags);
104 	cmdinfo->state |= UNLINK_DATA_URBS;
105 	spin_unlock_irqrestore(&devinfo->lock, flags);
106 
107 	if (cmdinfo->data_in_urb)
108 		usb_unlink_urb(cmdinfo->data_in_urb);
109 	if (cmdinfo->data_out_urb)
110 		usb_unlink_urb(cmdinfo->data_out_urb);
111 
112 	spin_lock_irqsave(&devinfo->lock, flags);
113 	cmdinfo->state &= ~UNLINK_DATA_URBS;
114 	spin_unlock_irqrestore(&devinfo->lock, flags);
115 }
116 
117 static void uas_do_work(struct work_struct *work)
118 {
119 	struct uas_cmd_info *cmdinfo;
120 	struct uas_cmd_info *temp;
121 	struct list_head list;
122 	unsigned long flags;
123 	int err;
124 
125 	spin_lock_irq(&uas_work_lock);
126 	list_replace_init(&uas_work_list, &list);
127 	spin_unlock_irq(&uas_work_lock);
128 
129 	list_for_each_entry_safe(cmdinfo, temp, &list, list) {
130 		struct scsi_pointer *scp = (void *)cmdinfo;
131 		struct scsi_cmnd *cmnd = container_of(scp,
132 							struct scsi_cmnd, SCp);
133 		struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
134 		spin_lock_irqsave(&devinfo->lock, flags);
135 		err = uas_submit_urbs(cmnd, cmnd->device->hostdata, GFP_ATOMIC);
136 		if (!err)
137 			cmdinfo->state &= ~IS_IN_WORK_LIST;
138 		spin_unlock_irqrestore(&devinfo->lock, flags);
139 		if (err) {
140 			list_del(&cmdinfo->list);
141 			spin_lock_irq(&uas_work_lock);
142 			list_add_tail(&cmdinfo->list, &uas_work_list);
143 			spin_unlock_irq(&uas_work_lock);
144 			schedule_work(&uas_work);
145 		}
146 	}
147 }
148 
149 static void uas_abort_work(struct uas_dev_info *devinfo)
150 {
151 	struct uas_cmd_info *cmdinfo;
152 	struct uas_cmd_info *temp;
153 	struct list_head list;
154 	unsigned long flags;
155 
156 	spin_lock_irq(&uas_work_lock);
157 	list_replace_init(&uas_work_list, &list);
158 	spin_unlock_irq(&uas_work_lock);
159 
160 	spin_lock_irqsave(&devinfo->lock, flags);
161 	list_for_each_entry_safe(cmdinfo, temp, &list, list) {
162 		struct scsi_pointer *scp = (void *)cmdinfo;
163 		struct scsi_cmnd *cmnd = container_of(scp,
164 							struct scsi_cmnd, SCp);
165 		struct uas_dev_info *di = (void *)cmnd->device->hostdata;
166 
167 		if (di == devinfo) {
168 			cmdinfo->state |= COMMAND_ABORTED;
169 			cmdinfo->state &= ~IS_IN_WORK_LIST;
170 			if (devinfo->resetting) {
171 				/* uas_stat_cmplt() will not do that
172 				 * when a device reset is in
173 				 * progress */
174 				cmdinfo->state &= ~COMMAND_INFLIGHT;
175 			}
176 			uas_try_complete(cmnd, __func__);
177 		} else {
178 			/* not our uas device, relink into list */
179 			list_del(&cmdinfo->list);
180 			spin_lock_irq(&uas_work_lock);
181 			list_add_tail(&cmdinfo->list, &uas_work_list);
182 			spin_unlock_irq(&uas_work_lock);
183 		}
184 	}
185 	spin_unlock_irqrestore(&devinfo->lock, flags);
186 }
187 
188 static void uas_sense(struct urb *urb, struct scsi_cmnd *cmnd)
189 {
190 	struct sense_iu *sense_iu = urb->transfer_buffer;
191 	struct scsi_device *sdev = cmnd->device;
192 
193 	if (urb->actual_length > 16) {
194 		unsigned len = be16_to_cpup(&sense_iu->len);
195 		if (len + 16 != urb->actual_length) {
196 			int newlen = min(len + 16, urb->actual_length) - 16;
197 			if (newlen < 0)
198 				newlen = 0;
199 			sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
200 				"disagrees with IU sense data length %d, "
201 				"using %d bytes of sense data\n", __func__,
202 					urb->actual_length, len, newlen);
203 			len = newlen;
204 		}
205 		memcpy(cmnd->sense_buffer, sense_iu->sense, len);
206 	}
207 
208 	cmnd->result = sense_iu->status;
209 }
210 
211 static void uas_sense_old(struct urb *urb, struct scsi_cmnd *cmnd)
212 {
213 	struct sense_iu_old *sense_iu = urb->transfer_buffer;
214 	struct scsi_device *sdev = cmnd->device;
215 
216 	if (urb->actual_length > 8) {
217 		unsigned len = be16_to_cpup(&sense_iu->len) - 2;
218 		if (len + 8 != urb->actual_length) {
219 			int newlen = min(len + 8, urb->actual_length) - 8;
220 			if (newlen < 0)
221 				newlen = 0;
222 			sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
223 				"disagrees with IU sense data length %d, "
224 				"using %d bytes of sense data\n", __func__,
225 					urb->actual_length, len, newlen);
226 			len = newlen;
227 		}
228 		memcpy(cmnd->sense_buffer, sense_iu->sense, len);
229 	}
230 
231 	cmnd->result = sense_iu->status;
232 }
233 
234 static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *caller)
235 {
236 	struct uas_cmd_info *ci = (void *)&cmnd->SCp;
237 
238 	scmd_printk(KERN_INFO, cmnd, "%s %p tag %d, inflight:"
239 		    "%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
240 		    caller, cmnd, cmnd->request->tag,
241 		    (ci->state & SUBMIT_STATUS_URB)     ? " s-st"  : "",
242 		    (ci->state & ALLOC_DATA_IN_URB)     ? " a-in"  : "",
243 		    (ci->state & SUBMIT_DATA_IN_URB)    ? " s-in"  : "",
244 		    (ci->state & ALLOC_DATA_OUT_URB)    ? " a-out" : "",
245 		    (ci->state & SUBMIT_DATA_OUT_URB)   ? " s-out" : "",
246 		    (ci->state & ALLOC_CMD_URB)         ? " a-cmd" : "",
247 		    (ci->state & SUBMIT_CMD_URB)        ? " s-cmd" : "",
248 		    (ci->state & COMMAND_INFLIGHT)      ? " CMD"   : "",
249 		    (ci->state & DATA_IN_URB_INFLIGHT)  ? " IN"    : "",
250 		    (ci->state & DATA_OUT_URB_INFLIGHT) ? " OUT"   : "",
251 		    (ci->state & COMMAND_COMPLETED)     ? " done"  : "",
252 		    (ci->state & COMMAND_ABORTED)       ? " abort" : "",
253 		    (ci->state & UNLINK_DATA_URBS)      ? " unlink": "",
254 		    (ci->state & IS_IN_WORK_LIST)       ? " work"  : "");
255 }
256 
257 static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller)
258 {
259 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
260 	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
261 
262 	WARN_ON(!spin_is_locked(&devinfo->lock));
263 	if (cmdinfo->state & (COMMAND_INFLIGHT |
264 			      DATA_IN_URB_INFLIGHT |
265 			      DATA_OUT_URB_INFLIGHT |
266 			      UNLINK_DATA_URBS))
267 		return -EBUSY;
268 	BUG_ON(cmdinfo->state & COMMAND_COMPLETED);
269 	cmdinfo->state |= COMMAND_COMPLETED;
270 	usb_free_urb(cmdinfo->data_in_urb);
271 	usb_free_urb(cmdinfo->data_out_urb);
272 	if (cmdinfo->state & COMMAND_ABORTED) {
273 		scmd_printk(KERN_INFO, cmnd, "abort completed\n");
274 		cmnd->result = DID_ABORT << 16;
275 	}
276 	cmnd->scsi_done(cmnd);
277 	return 0;
278 }
279 
280 static void uas_xfer_data(struct urb *urb, struct scsi_cmnd *cmnd,
281 			  unsigned direction)
282 {
283 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
284 	int err;
285 
286 	cmdinfo->state |= direction | SUBMIT_STATUS_URB;
287 	err = uas_submit_urbs(cmnd, cmnd->device->hostdata, GFP_ATOMIC);
288 	if (err) {
289 		spin_lock(&uas_work_lock);
290 		list_add_tail(&cmdinfo->list, &uas_work_list);
291 		cmdinfo->state |= IS_IN_WORK_LIST;
292 		spin_unlock(&uas_work_lock);
293 		schedule_work(&uas_work);
294 	}
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 = (void *)shost->hostdata[0];
302 	struct scsi_cmnd *cmnd;
303 	struct uas_cmd_info *cmdinfo;
304 	unsigned long flags;
305 	u16 tag;
306 
307 	if (urb->status) {
308 		dev_err(&urb->dev->dev, "URB BAD STATUS %d\n", urb->status);
309 		usb_free_urb(urb);
310 		return;
311 	}
312 
313 	if (devinfo->resetting) {
314 		usb_free_urb(urb);
315 		return;
316 	}
317 
318 	spin_lock_irqsave(&devinfo->lock, flags);
319 	tag = be16_to_cpup(&iu->tag) - 1;
320 	if (tag == 0)
321 		cmnd = devinfo->cmnd;
322 	else
323 		cmnd = scsi_host_find_tag(shost, tag - 1);
324 
325 	if (!cmnd) {
326 		if (iu->iu_id == IU_ID_RESPONSE) {
327 			/* store results for uas_eh_task_mgmt() */
328 			memcpy(&devinfo->response, iu, sizeof(devinfo->response));
329 		}
330 		usb_free_urb(urb);
331 		spin_unlock_irqrestore(&devinfo->lock, flags);
332 		return;
333 	}
334 
335 	cmdinfo = (void *)&cmnd->SCp;
336 	switch (iu->iu_id) {
337 	case IU_ID_STATUS:
338 		if (devinfo->cmnd == cmnd)
339 			devinfo->cmnd = NULL;
340 
341 		if (urb->actual_length < 16)
342 			devinfo->uas_sense_old = 1;
343 		if (devinfo->uas_sense_old)
344 			uas_sense_old(urb, cmnd);
345 		else
346 			uas_sense(urb, cmnd);
347 		if (cmnd->result != 0) {
348 			/* cancel data transfers on error */
349 			spin_unlock_irqrestore(&devinfo->lock, flags);
350 			uas_unlink_data_urbs(devinfo, cmdinfo);
351 			spin_lock_irqsave(&devinfo->lock, flags);
352 		}
353 		cmdinfo->state &= ~COMMAND_INFLIGHT;
354 		uas_try_complete(cmnd, __func__);
355 		break;
356 	case IU_ID_READ_READY:
357 		uas_xfer_data(urb, cmnd, SUBMIT_DATA_IN_URB);
358 		break;
359 	case IU_ID_WRITE_READY:
360 		uas_xfer_data(urb, cmnd, SUBMIT_DATA_OUT_URB);
361 		break;
362 	default:
363 		scmd_printk(KERN_ERR, cmnd,
364 			"Bogus IU (%d) received on status pipe\n", iu->iu_id);
365 	}
366 	usb_free_urb(urb);
367 	spin_unlock_irqrestore(&devinfo->lock, flags);
368 }
369 
370 static void uas_data_cmplt(struct urb *urb)
371 {
372 	struct scsi_cmnd *cmnd = urb->context;
373 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
374 	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
375 	struct scsi_data_buffer *sdb = NULL;
376 	unsigned long flags;
377 
378 	spin_lock_irqsave(&devinfo->lock, flags);
379 	if (cmdinfo->data_in_urb == urb) {
380 		sdb = scsi_in(cmnd);
381 		cmdinfo->state &= ~DATA_IN_URB_INFLIGHT;
382 	} else if (cmdinfo->data_out_urb == urb) {
383 		sdb = scsi_out(cmnd);
384 		cmdinfo->state &= ~DATA_OUT_URB_INFLIGHT;
385 	}
386 	BUG_ON(sdb == NULL);
387 	if (urb->status) {
388 		/* error: no data transfered */
389 		sdb->resid = sdb->length;
390 	} else {
391 		sdb->resid = sdb->length - urb->actual_length;
392 	}
393 	uas_try_complete(cmnd, __func__);
394 	spin_unlock_irqrestore(&devinfo->lock, flags);
395 }
396 
397 static struct urb *uas_alloc_data_urb(struct uas_dev_info *devinfo, gfp_t gfp,
398 				      unsigned int pipe, u16 stream_id,
399 				      struct scsi_cmnd *cmnd,
400 				      enum dma_data_direction dir)
401 {
402 	struct usb_device *udev = devinfo->udev;
403 	struct urb *urb = usb_alloc_urb(0, gfp);
404 	struct scsi_data_buffer *sdb = (dir == DMA_FROM_DEVICE)
405 		? scsi_in(cmnd) : scsi_out(cmnd);
406 
407 	if (!urb)
408 		goto out;
409 	usb_fill_bulk_urb(urb, udev, pipe, NULL, sdb->length,
410 			  uas_data_cmplt, cmnd);
411 	if (devinfo->use_streams)
412 		urb->stream_id = stream_id;
413 	urb->num_sgs = udev->bus->sg_tablesize ? sdb->table.nents : 0;
414 	urb->sg = sdb->table.sgl;
415  out:
416 	return urb;
417 }
418 
419 static struct urb *uas_alloc_sense_urb(struct uas_dev_info *devinfo, gfp_t gfp,
420 				       struct Scsi_Host *shost, u16 stream_id)
421 {
422 	struct usb_device *udev = devinfo->udev;
423 	struct urb *urb = usb_alloc_urb(0, gfp);
424 	struct sense_iu *iu;
425 
426 	if (!urb)
427 		goto out;
428 
429 	iu = kzalloc(sizeof(*iu), gfp);
430 	if (!iu)
431 		goto free;
432 
433 	usb_fill_bulk_urb(urb, udev, devinfo->status_pipe, iu, sizeof(*iu),
434 						uas_stat_cmplt, shost);
435 	urb->stream_id = stream_id;
436 	urb->transfer_flags |= URB_FREE_BUFFER;
437  out:
438 	return urb;
439  free:
440 	usb_free_urb(urb);
441 	return NULL;
442 }
443 
444 static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
445 					struct scsi_cmnd *cmnd, u16 stream_id)
446 {
447 	struct usb_device *udev = devinfo->udev;
448 	struct scsi_device *sdev = cmnd->device;
449 	struct urb *urb = usb_alloc_urb(0, gfp);
450 	struct command_iu *iu;
451 	int len;
452 
453 	if (!urb)
454 		goto out;
455 
456 	len = cmnd->cmd_len - 16;
457 	if (len < 0)
458 		len = 0;
459 	len = ALIGN(len, 4);
460 	iu = kzalloc(sizeof(*iu) + len, gfp);
461 	if (!iu)
462 		goto free;
463 
464 	iu->iu_id = IU_ID_COMMAND;
465 	if (blk_rq_tagged(cmnd->request))
466 		iu->tag = cpu_to_be16(cmnd->request->tag + 2);
467 	else
468 		iu->tag = cpu_to_be16(1);
469 	iu->prio_attr = UAS_SIMPLE_TAG;
470 	iu->len = len;
471 	int_to_scsilun(sdev->lun, &iu->lun);
472 	memcpy(iu->cdb, cmnd->cmnd, cmnd->cmd_len);
473 
474 	usb_fill_bulk_urb(urb, udev, devinfo->cmd_pipe, iu, sizeof(*iu) + len,
475 							usb_free_urb, NULL);
476 	urb->transfer_flags |= URB_FREE_BUFFER;
477  out:
478 	return urb;
479  free:
480 	usb_free_urb(urb);
481 	return NULL;
482 }
483 
484 static int uas_submit_task_urb(struct scsi_cmnd *cmnd, gfp_t gfp,
485 			       u8 function, u16 stream_id)
486 {
487 	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
488 	struct usb_device *udev = devinfo->udev;
489 	struct urb *urb = usb_alloc_urb(0, gfp);
490 	struct task_mgmt_iu *iu;
491 	int err = -ENOMEM;
492 
493 	if (!urb)
494 		goto err;
495 
496 	iu = kzalloc(sizeof(*iu), gfp);
497 	if (!iu)
498 		goto err;
499 
500 	iu->iu_id = IU_ID_TASK_MGMT;
501 	iu->tag = cpu_to_be16(stream_id);
502 	int_to_scsilun(cmnd->device->lun, &iu->lun);
503 
504 	iu->function = function;
505 	switch (function) {
506 	case TMF_ABORT_TASK:
507 		if (blk_rq_tagged(cmnd->request))
508 			iu->task_tag = cpu_to_be16(cmnd->request->tag + 2);
509 		else
510 			iu->task_tag = cpu_to_be16(1);
511 		break;
512 	}
513 
514 	usb_fill_bulk_urb(urb, udev, devinfo->cmd_pipe, iu, sizeof(*iu),
515 			  usb_free_urb, NULL);
516 	urb->transfer_flags |= URB_FREE_BUFFER;
517 
518 	err = usb_submit_urb(urb, gfp);
519 	if (err)
520 		goto err;
521 	usb_anchor_urb(urb, &devinfo->cmd_urbs);
522 
523 	return 0;
524 
525 err:
526 	usb_free_urb(urb);
527 	return err;
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 
536 static int uas_submit_sense_urb(struct Scsi_Host *shost,
537 				gfp_t gfp, unsigned int stream)
538 {
539 	struct uas_dev_info *devinfo = (void *)shost->hostdata[0];
540 	struct urb *urb;
541 
542 	urb = uas_alloc_sense_urb(devinfo, gfp, shost, stream);
543 	if (!urb)
544 		return SCSI_MLQUEUE_DEVICE_BUSY;
545 	if (usb_submit_urb(urb, gfp)) {
546 		shost_printk(KERN_INFO, shost,
547 			     "sense urb submission failure\n");
548 		usb_free_urb(urb);
549 		return SCSI_MLQUEUE_DEVICE_BUSY;
550 	}
551 	usb_anchor_urb(urb, &devinfo->sense_urbs);
552 	return 0;
553 }
554 
555 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
556 			   struct uas_dev_info *devinfo, gfp_t gfp)
557 {
558 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
559 	int err;
560 
561 	WARN_ON(!spin_is_locked(&devinfo->lock));
562 	if (cmdinfo->state & SUBMIT_STATUS_URB) {
563 		err = uas_submit_sense_urb(cmnd->device->host, gfp,
564 					   cmdinfo->stream);
565 		if (err) {
566 			return err;
567 		}
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,
573 					devinfo->data_in_pipe, cmdinfo->stream,
574 					cmnd, DMA_FROM_DEVICE);
575 		if (!cmdinfo->data_in_urb)
576 			return SCSI_MLQUEUE_DEVICE_BUSY;
577 		cmdinfo->state &= ~ALLOC_DATA_IN_URB;
578 	}
579 
580 	if (cmdinfo->state & SUBMIT_DATA_IN_URB) {
581 		if (usb_submit_urb(cmdinfo->data_in_urb, gfp)) {
582 			scmd_printk(KERN_INFO, cmnd,
583 					"data in urb submission failure\n");
584 			return SCSI_MLQUEUE_DEVICE_BUSY;
585 		}
586 		cmdinfo->state &= ~SUBMIT_DATA_IN_URB;
587 		cmdinfo->state |= DATA_IN_URB_INFLIGHT;
588 		usb_anchor_urb(cmdinfo->data_in_urb, &devinfo->data_urbs);
589 	}
590 
591 	if (cmdinfo->state & ALLOC_DATA_OUT_URB) {
592 		cmdinfo->data_out_urb = uas_alloc_data_urb(devinfo, gfp,
593 					devinfo->data_out_pipe, cmdinfo->stream,
594 					cmnd, DMA_TO_DEVICE);
595 		if (!cmdinfo->data_out_urb)
596 			return SCSI_MLQUEUE_DEVICE_BUSY;
597 		cmdinfo->state &= ~ALLOC_DATA_OUT_URB;
598 	}
599 
600 	if (cmdinfo->state & SUBMIT_DATA_OUT_URB) {
601 		if (usb_submit_urb(cmdinfo->data_out_urb, gfp)) {
602 			scmd_printk(KERN_INFO, cmnd,
603 					"data out urb submission failure\n");
604 			return SCSI_MLQUEUE_DEVICE_BUSY;
605 		}
606 		cmdinfo->state &= ~SUBMIT_DATA_OUT_URB;
607 		cmdinfo->state |= DATA_OUT_URB_INFLIGHT;
608 		usb_anchor_urb(cmdinfo->data_out_urb, &devinfo->data_urbs);
609 	}
610 
611 	if (cmdinfo->state & ALLOC_CMD_URB) {
612 		cmdinfo->cmd_urb = uas_alloc_cmd_urb(devinfo, gfp, cmnd,
613 						     cmdinfo->stream);
614 		if (!cmdinfo->cmd_urb)
615 			return SCSI_MLQUEUE_DEVICE_BUSY;
616 		cmdinfo->state &= ~ALLOC_CMD_URB;
617 	}
618 
619 	if (cmdinfo->state & SUBMIT_CMD_URB) {
620 		usb_get_urb(cmdinfo->cmd_urb);
621 		if (usb_submit_urb(cmdinfo->cmd_urb, gfp)) {
622 			scmd_printk(KERN_INFO, cmnd,
623 					"cmd urb submission failure\n");
624 			return SCSI_MLQUEUE_DEVICE_BUSY;
625 		}
626 		usb_anchor_urb(cmdinfo->cmd_urb, &devinfo->cmd_urbs);
627 		usb_put_urb(cmdinfo->cmd_urb);
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 err;
644 
645 	BUILD_BUG_ON(sizeof(struct uas_cmd_info) > sizeof(struct scsi_pointer));
646 
647 	if (devinfo->resetting) {
648 		cmnd->result = DID_ERROR << 16;
649 		cmnd->scsi_done(cmnd);
650 		return 0;
651 	}
652 
653 	spin_lock_irqsave(&devinfo->lock, flags);
654 	if (devinfo->cmnd) {
655 		spin_unlock_irqrestore(&devinfo->lock, flags);
656 		return SCSI_MLQUEUE_DEVICE_BUSY;
657 	}
658 
659 	if (blk_rq_tagged(cmnd->request)) {
660 		cmdinfo->stream = cmnd->request->tag + 2;
661 	} else {
662 		devinfo->cmnd = cmnd;
663 		cmdinfo->stream = 1;
664 	}
665 
666 	cmnd->scsi_done = done;
667 
668 	cmdinfo->state = SUBMIT_STATUS_URB |
669 			ALLOC_CMD_URB | SUBMIT_CMD_URB;
670 
671 	switch (cmnd->sc_data_direction) {
672 	case DMA_FROM_DEVICE:
673 		cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
674 		break;
675 	case DMA_BIDIRECTIONAL:
676 		cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
677 	case DMA_TO_DEVICE:
678 		cmdinfo->state |= ALLOC_DATA_OUT_URB | SUBMIT_DATA_OUT_URB;
679 	case DMA_NONE:
680 		break;
681 	}
682 
683 	if (!devinfo->use_streams) {
684 		cmdinfo->state &= ~(SUBMIT_DATA_IN_URB | SUBMIT_DATA_OUT_URB);
685 		cmdinfo->stream = 0;
686 	}
687 
688 	err = uas_submit_urbs(cmnd, devinfo, GFP_ATOMIC);
689 	if (err) {
690 		/* If we did nothing, give up now */
691 		if (cmdinfo->state & SUBMIT_STATUS_URB) {
692 			spin_unlock_irqrestore(&devinfo->lock, flags);
693 			return SCSI_MLQUEUE_DEVICE_BUSY;
694 		}
695 		spin_lock(&uas_work_lock);
696 		list_add_tail(&cmdinfo->list, &uas_work_list);
697 		cmdinfo->state |= IS_IN_WORK_LIST;
698 		spin_unlock(&uas_work_lock);
699 		schedule_work(&uas_work);
700 	}
701 
702 	spin_unlock_irqrestore(&devinfo->lock, flags);
703 	return 0;
704 }
705 
706 static DEF_SCSI_QCMD(uas_queuecommand)
707 
708 static int uas_eh_task_mgmt(struct scsi_cmnd *cmnd,
709 			    const char *fname, u8 function)
710 {
711 	struct Scsi_Host *shost = cmnd->device->host;
712 	struct uas_dev_info *devinfo = (void *)shost->hostdata[0];
713 	u16 tag = devinfo->qdepth - 1;
714 	unsigned long flags;
715 
716 	spin_lock_irqsave(&devinfo->lock, flags);
717 	memset(&devinfo->response, 0, sizeof(devinfo->response));
718 	if (uas_submit_sense_urb(shost, GFP_ATOMIC, tag)) {
719 		shost_printk(KERN_INFO, shost,
720 			     "%s: %s: submit sense urb failed\n",
721 			     __func__, fname);
722 		spin_unlock_irqrestore(&devinfo->lock, flags);
723 		return FAILED;
724 	}
725 	if (uas_submit_task_urb(cmnd, GFP_ATOMIC, function, tag)) {
726 		shost_printk(KERN_INFO, shost,
727 			     "%s: %s: submit task mgmt urb failed\n",
728 			     __func__, fname);
729 		spin_unlock_irqrestore(&devinfo->lock, flags);
730 		return FAILED;
731 	}
732 	spin_unlock_irqrestore(&devinfo->lock, flags);
733 
734 	if (usb_wait_anchor_empty_timeout(&devinfo->sense_urbs, 3000) == 0) {
735 		shost_printk(KERN_INFO, shost,
736 			     "%s: %s timed out\n", __func__, fname);
737 		return FAILED;
738 	}
739 	if (be16_to_cpu(devinfo->response.tag) != tag) {
740 		shost_printk(KERN_INFO, shost,
741 			     "%s: %s failed (wrong tag %d/%d)\n", __func__,
742 			     fname, be16_to_cpu(devinfo->response.tag), tag);
743 		return FAILED;
744 	}
745 	if (devinfo->response.response_code != RC_TMF_COMPLETE) {
746 		shost_printk(KERN_INFO, shost,
747 			     "%s: %s failed (rc 0x%x)\n", __func__,
748 			     fname, devinfo->response.response_code);
749 		return FAILED;
750 	}
751 	return SUCCESS;
752 }
753 
754 static int uas_eh_abort_handler(struct scsi_cmnd *cmnd)
755 {
756 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
757 	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
758 	unsigned long flags;
759 	int ret;
760 
761 	uas_log_cmd_state(cmnd, __func__);
762 	spin_lock_irqsave(&devinfo->lock, flags);
763 	cmdinfo->state |= COMMAND_ABORTED;
764 	if (cmdinfo->state & IS_IN_WORK_LIST) {
765 		spin_lock(&uas_work_lock);
766 		list_del(&cmdinfo->list);
767 		cmdinfo->state &= ~IS_IN_WORK_LIST;
768 		spin_unlock(&uas_work_lock);
769 	}
770 	if (cmdinfo->state & COMMAND_INFLIGHT) {
771 		spin_unlock_irqrestore(&devinfo->lock, flags);
772 		ret = uas_eh_task_mgmt(cmnd, "ABORT TASK", TMF_ABORT_TASK);
773 	} else {
774 		spin_unlock_irqrestore(&devinfo->lock, flags);
775 		uas_unlink_data_urbs(devinfo, cmdinfo);
776 		spin_lock_irqsave(&devinfo->lock, flags);
777 		uas_try_complete(cmnd, __func__);
778 		spin_unlock_irqrestore(&devinfo->lock, flags);
779 		ret = SUCCESS;
780 	}
781 	return ret;
782 }
783 
784 static int uas_eh_device_reset_handler(struct scsi_cmnd *cmnd)
785 {
786 	sdev_printk(KERN_INFO, cmnd->device, "%s\n", __func__);
787 	return uas_eh_task_mgmt(cmnd, "LOGICAL UNIT RESET",
788 				TMF_LOGICAL_UNIT_RESET);
789 }
790 
791 static int uas_eh_bus_reset_handler(struct scsi_cmnd *cmnd)
792 {
793 	struct scsi_device *sdev = cmnd->device;
794 	struct uas_dev_info *devinfo = sdev->hostdata;
795 	struct usb_device *udev = devinfo->udev;
796 	int err;
797 
798 	devinfo->resetting = 1;
799 	uas_abort_work(devinfo);
800 	usb_kill_anchored_urbs(&devinfo->cmd_urbs);
801 	usb_kill_anchored_urbs(&devinfo->sense_urbs);
802 	usb_kill_anchored_urbs(&devinfo->data_urbs);
803 	err = usb_reset_device(udev);
804 	devinfo->resetting = 0;
805 
806 	if (err) {
807 		shost_printk(KERN_INFO, sdev->host, "%s FAILED\n", __func__);
808 		return FAILED;
809 	}
810 
811 	shost_printk(KERN_INFO, sdev->host, "%s success\n", __func__);
812 	return SUCCESS;
813 }
814 
815 static int uas_slave_alloc(struct scsi_device *sdev)
816 {
817 	sdev->hostdata = (void *)sdev->host->hostdata[0];
818 	return 0;
819 }
820 
821 static int uas_slave_configure(struct scsi_device *sdev)
822 {
823 	struct uas_dev_info *devinfo = sdev->hostdata;
824 	scsi_set_tag_type(sdev, MSG_ORDERED_TAG);
825 	scsi_activate_tcq(sdev, devinfo->qdepth - 3);
826 	return 0;
827 }
828 
829 static struct scsi_host_template uas_host_template = {
830 	.module = THIS_MODULE,
831 	.name = "uas",
832 	.queuecommand = uas_queuecommand,
833 	.slave_alloc = uas_slave_alloc,
834 	.slave_configure = uas_slave_configure,
835 	.eh_abort_handler = uas_eh_abort_handler,
836 	.eh_device_reset_handler = uas_eh_device_reset_handler,
837 	.eh_bus_reset_handler = uas_eh_bus_reset_handler,
838 	.can_queue = 65536,	/* Is there a limit on the _host_ ? */
839 	.this_id = -1,
840 	.sg_tablesize = SG_NONE,
841 	.cmd_per_lun = 1,	/* until we override it */
842 	.skip_settle_delay = 1,
843 	.ordered_tag = 1,
844 };
845 
846 static struct usb_device_id uas_usb_ids[] = {
847 	{ USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_BULK) },
848 	{ USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_UAS) },
849 	/* 0xaa is a prototype device I happen to have access to */
850 	{ USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, 0xaa) },
851 	{ }
852 };
853 MODULE_DEVICE_TABLE(usb, uas_usb_ids);
854 
855 static int uas_is_interface(struct usb_host_interface *intf)
856 {
857 	return (intf->desc.bInterfaceClass == USB_CLASS_MASS_STORAGE &&
858 		intf->desc.bInterfaceSubClass == USB_SC_SCSI &&
859 		intf->desc.bInterfaceProtocol == USB_PR_UAS);
860 }
861 
862 static int uas_isnt_supported(struct usb_device *udev)
863 {
864 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
865 
866 	dev_warn(&udev->dev, "The driver for the USB controller %s does not "
867 			"support scatter-gather which is\n",
868 			hcd->driver->description);
869 	dev_warn(&udev->dev, "required by the UAS driver. Please try an"
870 			"alternative USB controller if you wish to use UAS.\n");
871 	return -ENODEV;
872 }
873 
874 static int uas_switch_interface(struct usb_device *udev,
875 						struct usb_interface *intf)
876 {
877 	int i;
878 	int sg_supported = udev->bus->sg_tablesize != 0;
879 
880 	for (i = 0; i < intf->num_altsetting; i++) {
881 		struct usb_host_interface *alt = &intf->altsetting[i];
882 
883 		if (uas_is_interface(alt)) {
884 			if (!sg_supported)
885 				return uas_isnt_supported(udev);
886 			return usb_set_interface(udev,
887 						alt->desc.bInterfaceNumber,
888 						alt->desc.bAlternateSetting);
889 		}
890 	}
891 
892 	return -ENODEV;
893 }
894 
895 static void uas_configure_endpoints(struct uas_dev_info *devinfo)
896 {
897 	struct usb_host_endpoint *eps[4] = { };
898 	struct usb_interface *intf = devinfo->intf;
899 	struct usb_device *udev = devinfo->udev;
900 	struct usb_host_endpoint *endpoint = intf->cur_altsetting->endpoint;
901 	unsigned i, n_endpoints = intf->cur_altsetting->desc.bNumEndpoints;
902 
903 	devinfo->uas_sense_old = 0;
904 	devinfo->cmnd = NULL;
905 
906 	for (i = 0; i < n_endpoints; i++) {
907 		unsigned char *extra = endpoint[i].extra;
908 		int len = endpoint[i].extralen;
909 		while (len > 1) {
910 			if (extra[1] == USB_DT_PIPE_USAGE) {
911 				unsigned pipe_id = extra[2];
912 				if (pipe_id > 0 && pipe_id < 5)
913 					eps[pipe_id - 1] = &endpoint[i];
914 				break;
915 			}
916 			len -= extra[0];
917 			extra += extra[0];
918 		}
919 	}
920 
921 	/*
922 	 * Assume that if we didn't find a control pipe descriptor, we're
923 	 * using a device with old firmware that happens to be set up like
924 	 * this.
925 	 */
926 	if (!eps[0]) {
927 		devinfo->cmd_pipe = usb_sndbulkpipe(udev, 1);
928 		devinfo->status_pipe = usb_rcvbulkpipe(udev, 1);
929 		devinfo->data_in_pipe = usb_rcvbulkpipe(udev, 2);
930 		devinfo->data_out_pipe = usb_sndbulkpipe(udev, 2);
931 
932 		eps[1] = usb_pipe_endpoint(udev, devinfo->status_pipe);
933 		eps[2] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
934 		eps[3] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
935 	} else {
936 		devinfo->cmd_pipe = usb_sndbulkpipe(udev,
937 						eps[0]->desc.bEndpointAddress);
938 		devinfo->status_pipe = usb_rcvbulkpipe(udev,
939 						eps[1]->desc.bEndpointAddress);
940 		devinfo->data_in_pipe = usb_rcvbulkpipe(udev,
941 						eps[2]->desc.bEndpointAddress);
942 		devinfo->data_out_pipe = usb_sndbulkpipe(udev,
943 						eps[3]->desc.bEndpointAddress);
944 	}
945 
946 	devinfo->qdepth = usb_alloc_streams(devinfo->intf, eps + 1, 3, 256,
947 								GFP_KERNEL);
948 	if (devinfo->qdepth < 0) {
949 		devinfo->qdepth = 256;
950 		devinfo->use_streams = 0;
951 	} else {
952 		devinfo->use_streams = 1;
953 	}
954 }
955 
956 static void uas_free_streams(struct uas_dev_info *devinfo)
957 {
958 	struct usb_device *udev = devinfo->udev;
959 	struct usb_host_endpoint *eps[3];
960 
961 	eps[0] = usb_pipe_endpoint(udev, devinfo->status_pipe);
962 	eps[1] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
963 	eps[2] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
964 	usb_free_streams(devinfo->intf, eps, 3, GFP_KERNEL);
965 }
966 
967 /*
968  * XXX: What I'd like to do here is register a SCSI host for each USB host in
969  * the system.  Follow usb-storage's design of registering a SCSI host for
970  * each USB device for the moment.  Can implement this by walking up the
971  * USB hierarchy until we find a USB host.
972  */
973 static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id)
974 {
975 	int result;
976 	struct Scsi_Host *shost;
977 	struct uas_dev_info *devinfo;
978 	struct usb_device *udev = interface_to_usbdev(intf);
979 
980 	if (uas_switch_interface(udev, intf))
981 		return -ENODEV;
982 
983 	devinfo = kmalloc(sizeof(struct uas_dev_info), GFP_KERNEL);
984 	if (!devinfo)
985 		return -ENOMEM;
986 
987 	result = -ENOMEM;
988 	shost = scsi_host_alloc(&uas_host_template, sizeof(void *));
989 	if (!shost)
990 		goto free;
991 
992 	shost->max_cmd_len = 16 + 252;
993 	shost->max_id = 1;
994 	shost->max_lun = 256;
995 	shost->max_channel = 0;
996 	shost->sg_tablesize = udev->bus->sg_tablesize;
997 
998 	devinfo->intf = intf;
999 	devinfo->udev = udev;
1000 	devinfo->resetting = 0;
1001 	init_usb_anchor(&devinfo->cmd_urbs);
1002 	init_usb_anchor(&devinfo->sense_urbs);
1003 	init_usb_anchor(&devinfo->data_urbs);
1004 	spin_lock_init(&devinfo->lock);
1005 	uas_configure_endpoints(devinfo);
1006 
1007 	result = scsi_init_shared_tag_map(shost, devinfo->qdepth - 3);
1008 	if (result)
1009 		goto free;
1010 
1011 	result = scsi_add_host(shost, &intf->dev);
1012 	if (result)
1013 		goto deconfig_eps;
1014 
1015 	shost->hostdata[0] = (unsigned long)devinfo;
1016 
1017 	scsi_scan_host(shost);
1018 	usb_set_intfdata(intf, shost);
1019 	return result;
1020 
1021 deconfig_eps:
1022 	uas_free_streams(devinfo);
1023  free:
1024 	kfree(devinfo);
1025 	if (shost)
1026 		scsi_host_put(shost);
1027 	return result;
1028 }
1029 
1030 static int uas_pre_reset(struct usb_interface *intf)
1031 {
1032 /* XXX: Need to return 1 if it's not our device in error handling */
1033 	return 0;
1034 }
1035 
1036 static int uas_post_reset(struct usb_interface *intf)
1037 {
1038 /* XXX: Need to return 1 if it's not our device in error handling */
1039 	return 0;
1040 }
1041 
1042 static void uas_disconnect(struct usb_interface *intf)
1043 {
1044 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1045 	struct uas_dev_info *devinfo = (void *)shost->hostdata[0];
1046 
1047 	devinfo->resetting = 1;
1048 	uas_abort_work(devinfo);
1049 	usb_kill_anchored_urbs(&devinfo->cmd_urbs);
1050 	usb_kill_anchored_urbs(&devinfo->sense_urbs);
1051 	usb_kill_anchored_urbs(&devinfo->data_urbs);
1052 	scsi_remove_host(shost);
1053 	uas_free_streams(devinfo);
1054 	kfree(devinfo);
1055 }
1056 
1057 /*
1058  * XXX: Should this plug into libusual so we can auto-upgrade devices from
1059  * Bulk-Only to UAS?
1060  */
1061 static struct usb_driver uas_driver = {
1062 	.name = "uas",
1063 	.probe = uas_probe,
1064 	.disconnect = uas_disconnect,
1065 	.pre_reset = uas_pre_reset,
1066 	.post_reset = uas_post_reset,
1067 	.id_table = uas_usb_ids,
1068 };
1069 
1070 module_usb_driver(uas_driver);
1071 
1072 MODULE_LICENSE("GPL");
1073 MODULE_AUTHOR("Matthew Wilcox and Sarah Sharp");
1074