1 /*
2 * The low performance USB storage driver (ub).
3 *
4 * Copyright (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
5 * Copyright (C) 2004 Pete Zaitcev (zaitcev@yahoo.com)
6 *
7 * This work is a part of Linux kernel, is derived from it,
8 * and is not licensed separately. See file COPYING for details.
9 *
10 * TODO (sorted by decreasing priority)
11 * -- Return sense now that rq allows it (we always auto-sense anyway).
12 * -- set readonly flag for CDs, set removable flag for CF readers
13 * -- do inquiry and verify we got a disk and not a tape (for LUN mismatch)
14 * -- verify the 13 conditions and do bulk resets
15 * -- highmem
16 * -- move top_sense and work_bcs into separate allocations (if they survive)
17 * for cache purists and esoteric architectures.
18 * -- Allocate structure for LUN 0 before the first ub_sync_tur, avoid NULL. ?
19 * -- prune comments, they are too volumnous
20 * -- Resove XXX's
21 * -- CLEAR, CLR2STS, CLRRS seem to be ripe for refactoring.
22 */
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/usb.h>
26 #include <linux/usb_usual.h>
27 #include <linux/blkdev.h>
28 #include <linux/timer.h>
29 #include <linux/scatterlist.h>
30 #include <scsi/scsi.h>
31
32 #define DRV_NAME "ub"
33
34 #define UB_MAJOR 180
35
36 /*
37 * The command state machine is the key model for understanding of this driver.
38 *
39 * The general rule is that all transitions are done towards the bottom
40 * of the diagram, thus preventing any loops.
41 *
42 * An exception to that is how the STAT state is handled. A counter allows it
43 * to be re-entered along the path marked with [C].
44 *
45 * +--------+
46 * ! INIT !
47 * +--------+
48 * !
49 * ub_scsi_cmd_start fails ->--------------------------------------\
50 * ! !
51 * V !
52 * +--------+ !
53 * ! CMD ! !
54 * +--------+ !
55 * ! +--------+ !
56 * was -EPIPE -->-------------------------------->! CLEAR ! !
57 * ! +--------+ !
58 * ! ! !
59 * was error -->------------------------------------- ! --------->\
60 * ! ! !
61 * /--<-- cmd->dir == NONE ? ! !
62 * ! ! ! !
63 * ! V ! !
64 * ! +--------+ ! !
65 * ! ! DATA ! ! !
66 * ! +--------+ ! !
67 * ! ! +---------+ ! !
68 * ! was -EPIPE -->--------------->! CLR2STS ! ! !
69 * ! ! +---------+ ! !
70 * ! ! ! ! !
71 * ! ! was error -->---- ! --------->\
72 * ! was error -->--------------------- ! ------------- ! --------->\
73 * ! ! ! ! !
74 * ! V ! ! !
75 * \--->+--------+ ! ! !
76 * ! STAT !<--------------------------/ ! !
77 * /--->+--------+ ! !
78 * ! ! ! !
79 * [C] was -EPIPE -->-----------\ ! !
80 * ! ! ! ! !
81 * +<---- len == 0 ! ! !
82 * ! ! ! ! !
83 * ! was error -->--------------------------------------!---------->\
84 * ! ! ! ! !
85 * +<---- bad CSW ! ! !
86 * +<---- bad tag ! ! !
87 * ! ! V ! !
88 * ! ! +--------+ ! !
89 * ! ! ! CLRRS ! ! !
90 * ! ! +--------+ ! !
91 * ! ! ! ! !
92 * \------- ! --------------------[C]--------\ ! !
93 * ! ! ! !
94 * cmd->error---\ +--------+ ! !
95 * ! +--------------->! SENSE !<----------/ !
96 * STAT_FAIL----/ +--------+ !
97 * ! ! V
98 * ! V +--------+
99 * \--------------------------------\--------------------->! DONE !
100 * +--------+
101 */
102
103 /*
104 * This many LUNs per USB device.
105 * Every one of them takes a host, see UB_MAX_HOSTS.
106 */
107 #define UB_MAX_LUNS 9
108
109 /*
110 */
111
112 #define UB_PARTS_PER_LUN 8
113
114 #define UB_MAX_CDB_SIZE 16 /* Corresponds to Bulk */
115
116 #define UB_SENSE_SIZE 18
117
118 /*
119 */
120
121 /* command block wrapper */
122 struct bulk_cb_wrap {
123 __le32 Signature; /* contains 'USBC' */
124 u32 Tag; /* unique per command id */
125 __le32 DataTransferLength; /* size of data */
126 u8 Flags; /* direction in bit 0 */
127 u8 Lun; /* LUN */
128 u8 Length; /* of of the CDB */
129 u8 CDB[UB_MAX_CDB_SIZE]; /* max command */
130 };
131
132 #define US_BULK_CB_WRAP_LEN 31
133 #define US_BULK_CB_SIGN 0x43425355 /*spells out USBC */
134 #define US_BULK_FLAG_IN 1
135 #define US_BULK_FLAG_OUT 0
136
137 /* command status wrapper */
138 struct bulk_cs_wrap {
139 __le32 Signature; /* should = 'USBS' */
140 u32 Tag; /* same as original command */
141 __le32 Residue; /* amount not transferred */
142 u8 Status; /* see below */
143 };
144
145 #define US_BULK_CS_WRAP_LEN 13
146 #define US_BULK_CS_SIGN 0x53425355 /* spells out 'USBS' */
147 #define US_BULK_STAT_OK 0
148 #define US_BULK_STAT_FAIL 1
149 #define US_BULK_STAT_PHASE 2
150
151 /* bulk-only class specific requests */
152 #define US_BULK_RESET_REQUEST 0xff
153 #define US_BULK_GET_MAX_LUN 0xfe
154
155 /*
156 */
157 struct ub_dev;
158
159 #define UB_MAX_REQ_SG 9 /* cdrecord requires 32KB and maybe a header */
160 #define UB_MAX_SECTORS 64
161
162 /*
163 * A second is more than enough for a 32K transfer (UB_MAX_SECTORS)
164 * even if a webcam hogs the bus, but some devices need time to spin up.
165 */
166 #define UB_URB_TIMEOUT (HZ*2)
167 #define UB_DATA_TIMEOUT (HZ*5) /* ZIP does spin-ups in the data phase */
168 #define UB_STAT_TIMEOUT (HZ*5) /* Same spinups and eject for a dataless cmd. */
169 #define UB_CTRL_TIMEOUT (HZ/2) /* 500ms ought to be enough to clear a stall */
170
171 /*
172 * An instance of a SCSI command in transit.
173 */
174 #define UB_DIR_NONE 0
175 #define UB_DIR_READ 1
176 #define UB_DIR_ILLEGAL2 2
177 #define UB_DIR_WRITE 3
178
179 #define UB_DIR_CHAR(c) (((c)==UB_DIR_WRITE)? 'w': \
180 (((c)==UB_DIR_READ)? 'r': 'n'))
181
182 enum ub_scsi_cmd_state {
183 UB_CMDST_INIT, /* Initial state */
184 UB_CMDST_CMD, /* Command submitted */
185 UB_CMDST_DATA, /* Data phase */
186 UB_CMDST_CLR2STS, /* Clearing before requesting status */
187 UB_CMDST_STAT, /* Status phase */
188 UB_CMDST_CLEAR, /* Clearing a stall (halt, actually) */
189 UB_CMDST_CLRRS, /* Clearing before retrying status */
190 UB_CMDST_SENSE, /* Sending Request Sense */
191 UB_CMDST_DONE /* Final state */
192 };
193
194 struct ub_scsi_cmd {
195 unsigned char cdb[UB_MAX_CDB_SIZE];
196 unsigned char cdb_len;
197
198 unsigned char dir; /* 0 - none, 1 - read, 3 - write. */
199 enum ub_scsi_cmd_state state;
200 unsigned int tag;
201 struct ub_scsi_cmd *next;
202
203 int error; /* Return code - valid upon done */
204 unsigned int act_len; /* Return size */
205 unsigned char key, asc, ascq; /* May be valid if error==-EIO */
206
207 int stat_count; /* Retries getting status. */
208 unsigned int timeo; /* jiffies until rq->timeout changes */
209
210 unsigned int len; /* Requested length */
211 unsigned int current_sg;
212 unsigned int nsg; /* sgv[nsg] */
213 struct scatterlist sgv[UB_MAX_REQ_SG];
214
215 struct ub_lun *lun;
216 void (*done)(struct ub_dev *, struct ub_scsi_cmd *);
217 void *back;
218 };
219
220 struct ub_request {
221 struct request *rq;
222 unsigned int current_try;
223 unsigned int nsg; /* sgv[nsg] */
224 struct scatterlist sgv[UB_MAX_REQ_SG];
225 };
226
227 /*
228 */
229 struct ub_capacity {
230 unsigned long nsec; /* Linux size - 512 byte sectors */
231 unsigned int bsize; /* Linux hardsect_size */
232 unsigned int bshift; /* Shift between 512 and hard sects */
233 };
234
235 /*
236 * This is a direct take-off from linux/include/completion.h
237 * The difference is that I do not wait on this thing, just poll.
238 * When I want to wait (ub_probe), I just use the stock completion.
239 *
240 * Note that INIT_COMPLETION takes no lock. It is correct. But why
241 * in the bloody hell that thing takes struct instead of pointer to struct
242 * is quite beyond me. I just copied it from the stock completion.
243 */
244 struct ub_completion {
245 unsigned int done;
246 spinlock_t lock;
247 };
248
249 static inline void ub_init_completion(struct ub_completion *x)
250 {
251 x->done = 0;
252 spin_lock_init(&x->lock);
253 }
254
255 #define UB_INIT_COMPLETION(x) ((x).done = 0)
256
257 static void ub_complete(struct ub_completion *x)
258 {
259 unsigned long flags;
260
261 spin_lock_irqsave(&x->lock, flags);
262 x->done++;
263 spin_unlock_irqrestore(&x->lock, flags);
264 }
265
266 static int ub_is_completed(struct ub_completion *x)
267 {
268 unsigned long flags;
269 int ret;
270
271 spin_lock_irqsave(&x->lock, flags);
272 ret = x->done;
273 spin_unlock_irqrestore(&x->lock, flags);
274 return ret;
275 }
276
277 /*
278 */
279 struct ub_scsi_cmd_queue {
280 int qlen, qmax;
281 struct ub_scsi_cmd *head, *tail;
282 };
283
284 /*
285 * The block device instance (one per LUN).
286 */
287 struct ub_lun {
288 struct ub_dev *udev;
289 struct list_head link;
290 struct gendisk *disk;
291 int id; /* Host index */
292 int num; /* LUN number */
293 char name[16];
294
295 int changed; /* Media was changed */
296 int removable;
297 int readonly;
298
299 struct ub_request urq;
300
301 /* Use Ingo's mempool if or when we have more than one command. */
302 /*
303 * Currently we never need more than one command for the whole device.
304 * However, giving every LUN a command is a cheap and automatic way
305 * to enforce fairness between them.
306 */
307 int cmda[1];
308 struct ub_scsi_cmd cmdv[1];
309
310 struct ub_capacity capacity;
311 };
312
313 /*
314 * The USB device instance.
315 */
316 struct ub_dev {
317 spinlock_t *lock;
318 atomic_t poison; /* The USB device is disconnected */
319 int openc; /* protected by ub_lock! */
320 /* kref is too implicit for our taste */
321 int reset; /* Reset is running */
322 int bad_resid;
323 unsigned int tagcnt;
324 char name[12];
325 struct usb_device *dev;
326 struct usb_interface *intf;
327
328 struct list_head luns;
329
330 unsigned int send_bulk_pipe; /* cached pipe values */
331 unsigned int recv_bulk_pipe;
332 unsigned int send_ctrl_pipe;
333 unsigned int recv_ctrl_pipe;
334
335 struct tasklet_struct tasklet;
336
337 struct ub_scsi_cmd_queue cmd_queue;
338 struct ub_scsi_cmd top_rqs_cmd; /* REQUEST SENSE */
339 unsigned char top_sense[UB_SENSE_SIZE];
340
341 struct ub_completion work_done;
342 struct urb work_urb;
343 struct timer_list work_timer;
344 int last_pipe; /* What might need clearing */
345 __le32 signature; /* Learned signature */
346 struct bulk_cb_wrap work_bcb;
347 struct bulk_cs_wrap work_bcs;
348 struct usb_ctrlrequest work_cr;
349
350 struct work_struct reset_work;
351 wait_queue_head_t reset_wait;
352 };
353
354 /*
355 */
356 static void ub_cleanup(struct ub_dev *sc);
357 static int ub_request_fn_1(struct ub_lun *lun, struct request *rq);
358 static void ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
359 struct ub_scsi_cmd *cmd, struct ub_request *urq);
360 static void ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
361 struct ub_scsi_cmd *cmd, struct ub_request *urq);
362 static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
363 static void ub_end_rq(struct request *rq, unsigned int status);
364 static int ub_rw_cmd_retry(struct ub_dev *sc, struct ub_lun *lun,
365 struct ub_request *urq, struct ub_scsi_cmd *cmd);
366 static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
367 static void ub_urb_complete(struct urb *urb);
368 static void ub_scsi_action(unsigned long _dev);
369 static void ub_scsi_dispatch(struct ub_dev *sc);
370 static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
371 static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
372 static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc);
373 static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
374 static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
375 static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
376 static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
377 static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
378 int stalled_pipe);
379 static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd);
380 static void ub_reset_enter(struct ub_dev *sc, int try);
381 static void ub_reset_task(struct work_struct *work);
382 static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun);
383 static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
384 struct ub_capacity *ret);
385 static int ub_sync_reset(struct ub_dev *sc);
386 static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe);
387 static int ub_probe_lun(struct ub_dev *sc, int lnum);
388
389 /*
390 */
391 #ifdef CONFIG_USB_LIBUSUAL
392
393 #define ub_usb_ids usb_storage_usb_ids
394 #else
395
396 static struct usb_device_id ub_usb_ids[] = {
397 { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, US_SC_SCSI, US_PR_BULK) },
398 { }
399 };
400
401 MODULE_DEVICE_TABLE(usb, ub_usb_ids);
402 #endif /* CONFIG_USB_LIBUSUAL */
403
404 /*
405 * Find me a way to identify "next free minor" for add_disk(),
406 * and the array disappears the next day. However, the number of
407 * hosts has something to do with the naming and /proc/partitions.
408 * This has to be thought out in detail before changing.
409 * If UB_MAX_HOST was 1000, we'd use a bitmap. Or a better data structure.
410 */
411 #define UB_MAX_HOSTS 26
412 static char ub_hostv[UB_MAX_HOSTS];
413
414 #define UB_QLOCK_NUM 5
415 static spinlock_t ub_qlockv[UB_QLOCK_NUM];
416 static int ub_qlock_next = 0;
417
418 static DEFINE_SPINLOCK(ub_lock); /* Locks globals and ->openc */
419
420 /*
421 * The id allocator.
422 *
423 * This also stores the host for indexing by minor, which is somewhat dirty.
424 */
425 static int ub_id_get(void)
426 {
427 unsigned long flags;
428 int i;
429
430 spin_lock_irqsave(&ub_lock, flags);
431 for (i = 0; i < UB_MAX_HOSTS; i++) {
432 if (ub_hostv[i] == 0) {
433 ub_hostv[i] = 1;
434 spin_unlock_irqrestore(&ub_lock, flags);
435 return i;
436 }
437 }
438 spin_unlock_irqrestore(&ub_lock, flags);
439 return -1;
440 }
441
442 static void ub_id_put(int id)
443 {
444 unsigned long flags;
445
446 if (id < 0 || id >= UB_MAX_HOSTS) {
447 printk(KERN_ERR DRV_NAME ": bad host ID %d\n", id);
448 return;
449 }
450
451 spin_lock_irqsave(&ub_lock, flags);
452 if (ub_hostv[id] == 0) {
453 spin_unlock_irqrestore(&ub_lock, flags);
454 printk(KERN_ERR DRV_NAME ": freeing free host ID %d\n", id);
455 return;
456 }
457 ub_hostv[id] = 0;
458 spin_unlock_irqrestore(&ub_lock, flags);
459 }
460
461 /*
462 * This is necessitated by the fact that blk_cleanup_queue does not
463 * necesserily destroy the queue. Instead, it may merely decrease q->refcnt.
464 * Since our blk_init_queue() passes a spinlock common with ub_dev,
465 * we have life time issues when ub_cleanup frees ub_dev.
466 */
467 static spinlock_t *ub_next_lock(void)
468 {
469 unsigned long flags;
470 spinlock_t *ret;
471
472 spin_lock_irqsave(&ub_lock, flags);
473 ret = &ub_qlockv[ub_qlock_next];
474 ub_qlock_next = (ub_qlock_next + 1) % UB_QLOCK_NUM;
475 spin_unlock_irqrestore(&ub_lock, flags);
476 return ret;
477 }
478
479 /*
480 * Downcount for deallocation. This rides on two assumptions:
481 * - once something is poisoned, its refcount cannot grow
482 * - opens cannot happen at this time (del_gendisk was done)
483 * If the above is true, we can drop the lock, which we need for
484 * blk_cleanup_queue(): the silly thing may attempt to sleep.
485 * [Actually, it never needs to sleep for us, but it calls might_sleep()]
486 */
487 static void ub_put(struct ub_dev *sc)
488 {
489 unsigned long flags;
490
491 spin_lock_irqsave(&ub_lock, flags);
492 --sc->openc;
493 if (sc->openc == 0 && atomic_read(&sc->poison)) {
494 spin_unlock_irqrestore(&ub_lock, flags);
495 ub_cleanup(sc);
496 } else {
497 spin_unlock_irqrestore(&ub_lock, flags);
498 }
499 }
500
501 /*
502 * Final cleanup and deallocation.
503 */
504 static void ub_cleanup(struct ub_dev *sc)
505 {
506 struct list_head *p;
507 struct ub_lun *lun;
508 struct request_queue *q;
509
510 while (!list_empty(&sc->luns)) {
511 p = sc->luns.next;
512 lun = list_entry(p, struct ub_lun, link);
513 list_del(p);
514
515 /* I don't think queue can be NULL. But... Stolen from sx8.c */
516 if ((q = lun->disk->queue) != NULL)
517 blk_cleanup_queue(q);
518 /*
519 * If we zero disk->private_data BEFORE put_disk, we have
520 * to check for NULL all over the place in open, release,
521 * check_media and revalidate, because the block level
522 * semaphore is well inside the put_disk.
523 * But we cannot zero after the call, because *disk is gone.
524 * The sd.c is blatantly racy in this area.
525 */
526 /* disk->private_data = NULL; */
527 put_disk(lun->disk);
528 lun->disk = NULL;
529
530 ub_id_put(lun->id);
531 kfree(lun);
532 }
533
534 usb_set_intfdata(sc->intf, NULL);
535 usb_put_intf(sc->intf);
536 usb_put_dev(sc->dev);
537 kfree(sc);
538 }
539
540 /*
541 * The "command allocator".
542 */
543 static struct ub_scsi_cmd *ub_get_cmd(struct ub_lun *lun)
544 {
545 struct ub_scsi_cmd *ret;
546
547 if (lun->cmda[0])
548 return NULL;
549 ret = &lun->cmdv[0];
550 lun->cmda[0] = 1;
551 return ret;
552 }
553
554 static void ub_put_cmd(struct ub_lun *lun, struct ub_scsi_cmd *cmd)
555 {
556 if (cmd != &lun->cmdv[0]) {
557 printk(KERN_WARNING "%s: releasing a foreign cmd %p\n",
558 lun->name, cmd);
559 return;
560 }
561 if (!lun->cmda[0]) {
562 printk(KERN_WARNING "%s: releasing a free cmd\n", lun->name);
563 return;
564 }
565 lun->cmda[0] = 0;
566 }
567
568 /*
569 * The command queue.
570 */
571 static void ub_cmdq_add(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
572 {
573 struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
574
575 if (t->qlen++ == 0) {
576 t->head = cmd;
577 t->tail = cmd;
578 } else {
579 t->tail->next = cmd;
580 t->tail = cmd;
581 }
582
583 if (t->qlen > t->qmax)
584 t->qmax = t->qlen;
585 }
586
587 static void ub_cmdq_insert(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
588 {
589 struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
590
591 if (t->qlen++ == 0) {
592 t->head = cmd;
593 t->tail = cmd;
594 } else {
595 cmd->next = t->head;
596 t->head = cmd;
597 }
598
599 if (t->qlen > t->qmax)
600 t->qmax = t->qlen;
601 }
602
603 static struct ub_scsi_cmd *ub_cmdq_pop(struct ub_dev *sc)
604 {
605 struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
606 struct ub_scsi_cmd *cmd;
607
608 if (t->qlen == 0)
609 return NULL;
610 if (--t->qlen == 0)
611 t->tail = NULL;
612 cmd = t->head;
613 t->head = cmd->next;
614 cmd->next = NULL;
615 return cmd;
616 }
617
618 #define ub_cmdq_peek(sc) ((sc)->cmd_queue.head)
619
620 /*
621 * The request function is our main entry point
622 */
623
624 static void ub_request_fn(struct request_queue *q)
625 {
626 struct ub_lun *lun = q->queuedata;
627 struct request *rq;
628
629 while ((rq = blk_peek_request(q)) != NULL) {
630 if (ub_request_fn_1(lun, rq) != 0) {
631 blk_stop_queue(q);
632 break;
633 }
634 }
635 }
636
637 static int ub_request_fn_1(struct ub_lun *lun, struct request *rq)
638 {
639 struct ub_dev *sc = lun->udev;
640 struct ub_scsi_cmd *cmd;
641 struct ub_request *urq;
642 int n_elem;
643
644 if (atomic_read(&sc->poison)) {
645 blk_start_request(rq);
646 ub_end_rq(rq, DID_NO_CONNECT << 16);
647 return 0;
648 }
649
650 if (lun->changed && !blk_pc_request(rq)) {
651 blk_start_request(rq);
652 ub_end_rq(rq, SAM_STAT_CHECK_CONDITION);
653 return 0;
654 }
655
656 if (lun->urq.rq != NULL)
657 return -1;
658 if ((cmd = ub_get_cmd(lun)) == NULL)
659 return -1;
660 memset(cmd, 0, sizeof(struct ub_scsi_cmd));
661
662 blk_start_request(rq);
663
664 urq = &lun->urq;
665 memset(urq, 0, sizeof(struct ub_request));
666 urq->rq = rq;
667
668 /*
669 * get scatterlist from block layer
670 */
671 sg_init_table(&urq->sgv[0], UB_MAX_REQ_SG);
672 n_elem = blk_rq_map_sg(lun->disk->queue, rq, &urq->sgv[0]);
673 if (n_elem < 0) {
674 /* Impossible, because blk_rq_map_sg should not hit ENOMEM. */
675 printk(KERN_INFO "%s: failed request map (%d)\n",
676 lun->name, n_elem);
677 goto drop;
678 }
679 if (n_elem > UB_MAX_REQ_SG) { /* Paranoia */
680 printk(KERN_WARNING "%s: request with %d segments\n",
681 lun->name, n_elem);
682 goto drop;
683 }
684 urq->nsg = n_elem;
685
686 if (blk_pc_request(rq)) {
687 ub_cmd_build_packet(sc, lun, cmd, urq);
688 } else {
689 ub_cmd_build_block(sc, lun, cmd, urq);
690 }
691 cmd->state = UB_CMDST_INIT;
692 cmd->lun = lun;
693 cmd->done = ub_rw_cmd_done;
694 cmd->back = urq;
695
696 cmd->tag = sc->tagcnt++;
697 if (ub_submit_scsi(sc, cmd) != 0)
698 goto drop;
699
700 return 0;
701
702 drop:
703 ub_put_cmd(lun, cmd);
704 ub_end_rq(rq, DID_ERROR << 16);
705 return 0;
706 }
707
708 static void ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
709 struct ub_scsi_cmd *cmd, struct ub_request *urq)
710 {
711 struct request *rq = urq->rq;
712 unsigned int block, nblks;
713
714 if (rq_data_dir(rq) == WRITE)
715 cmd->dir = UB_DIR_WRITE;
716 else
717 cmd->dir = UB_DIR_READ;
718
719 cmd->nsg = urq->nsg;
720 memcpy(cmd->sgv, urq->sgv, sizeof(struct scatterlist) * cmd->nsg);
721
722 /*
723 * build the command
724 *
725 * The call to blk_queue_logical_block_size() guarantees that request
726 * is aligned, but it is given in terms of 512 byte units, always.
727 */
728 block = blk_rq_pos(rq) >> lun->capacity.bshift;
729 nblks = blk_rq_sectors(rq) >> lun->capacity.bshift;
730
731 cmd->cdb[0] = (cmd->dir == UB_DIR_READ)? READ_10: WRITE_10;
732 /* 10-byte uses 4 bytes of LBA: 2147483648KB, 2097152MB, 2048GB */
733 cmd->cdb[2] = block >> 24;
734 cmd->cdb[3] = block >> 16;
735 cmd->cdb[4] = block >> 8;
736 cmd->cdb[5] = block;
737 cmd->cdb[7] = nblks >> 8;
738 cmd->cdb[8] = nblks;
739 cmd->cdb_len = 10;
740
741 cmd->len = blk_rq_bytes(rq);
742 }
743
744 static void ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
745 struct ub_scsi_cmd *cmd, struct ub_request *urq)
746 {
747 struct request *rq = urq->rq;
748
749 if (blk_rq_bytes(rq) == 0) {
750 cmd->dir = UB_DIR_NONE;
751 } else {
752 if (rq_data_dir(rq) == WRITE)
753 cmd->dir = UB_DIR_WRITE;
754 else
755 cmd->dir = UB_DIR_READ;
756 }
757
758 cmd->nsg = urq->nsg;
759 memcpy(cmd->sgv, urq->sgv, sizeof(struct scatterlist) * cmd->nsg);
760
761 memcpy(&cmd->cdb, rq->cmd, rq->cmd_len);
762 cmd->cdb_len = rq->cmd_len;
763
764 cmd->len = blk_rq_bytes(rq);
765
766 /*
767 * To reapply this to every URB is not as incorrect as it looks.
768 * In return, we avoid any complicated tracking calculations.
769 */
770 cmd->timeo = rq->timeout;
771 }
772
773 static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
774 {
775 struct ub_lun *lun = cmd->lun;
776 struct ub_request *urq = cmd->back;
777 struct request *rq;
778 unsigned int scsi_status;
779
780 rq = urq->rq;
781
782 if (cmd->error == 0) {
783 if (blk_pc_request(rq)) {
784 if (cmd->act_len >= rq->resid_len)
785 rq->resid_len = 0;
786 else
787 rq->resid_len -= cmd->act_len;
788 scsi_status = 0;
789 } else {
790 if (cmd->act_len != cmd->len) {
791 scsi_status = SAM_STAT_CHECK_CONDITION;
792 } else {
793 scsi_status = 0;
794 }
795 }
796 } else {
797 if (blk_pc_request(rq)) {
798 /* UB_SENSE_SIZE is smaller than SCSI_SENSE_BUFFERSIZE */
799 memcpy(rq->sense, sc->top_sense, UB_SENSE_SIZE);
800 rq->sense_len = UB_SENSE_SIZE;
801 if (sc->top_sense[0] != 0)
802 scsi_status = SAM_STAT_CHECK_CONDITION;
803 else
804 scsi_status = DID_ERROR << 16;
805 } else {
806 if (cmd->error == -EIO &&
807 (cmd->key == 0 ||
808 cmd->key == MEDIUM_ERROR ||
809 cmd->key == UNIT_ATTENTION)) {
810 if (ub_rw_cmd_retry(sc, lun, urq, cmd) == 0)
811 return;
812 }
813 scsi_status = SAM_STAT_CHECK_CONDITION;
814 }
815 }
816
817 urq->rq = NULL;
818
819 ub_put_cmd(lun, cmd);
820 ub_end_rq(rq, scsi_status);
821 blk_start_queue(lun->disk->queue);
822 }
823
824 static void ub_end_rq(struct request *rq, unsigned int scsi_status)
825 {
826 int error;
827
828 if (scsi_status == 0) {
829 error = 0;
830 } else {
831 error = -EIO;
832 rq->errors = scsi_status;
833 }
834 __blk_end_request_all(rq, error);
835 }
836
837 static int ub_rw_cmd_retry(struct ub_dev *sc, struct ub_lun *lun,
838 struct ub_request *urq, struct ub_scsi_cmd *cmd)
839 {
840
841 if (atomic_read(&sc->poison))
842 return -ENXIO;
843
844 ub_reset_enter(sc, urq->current_try);
845
846 if (urq->current_try >= 3)
847 return -EIO;
848 urq->current_try++;
849
850 /* Remove this if anyone complains of flooding. */
851 printk(KERN_DEBUG "%s: dir %c len/act %d/%d "
852 "[sense %x %02x %02x] retry %d\n",
853 sc->name, UB_DIR_CHAR(cmd->dir), cmd->len, cmd->act_len,
854 cmd->key, cmd->asc, cmd->ascq, urq->current_try);
855
856 memset(cmd, 0, sizeof(struct ub_scsi_cmd));
857 ub_cmd_build_block(sc, lun, cmd, urq);
858
859 cmd->state = UB_CMDST_INIT;
860 cmd->lun = lun;
861 cmd->done = ub_rw_cmd_done;
862 cmd->back = urq;
863
864 cmd->tag = sc->tagcnt++;
865
866 #if 0 /* Wasteful */
867 return ub_submit_scsi(sc, cmd);
868 #else
869 ub_cmdq_add(sc, cmd);
870 return 0;
871 #endif
872 }
873
874 /*
875 * Submit a regular SCSI operation (not an auto-sense).
876 *
877 * The Iron Law of Good Submit Routine is:
878 * Zero return - callback is done, Nonzero return - callback is not done.
879 * No exceptions.
880 *
881 * Host is assumed locked.
882 */
883 static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
884 {
885
886 if (cmd->state != UB_CMDST_INIT ||
887 (cmd->dir != UB_DIR_NONE && cmd->len == 0)) {
888 return -EINVAL;
889 }
890
891 ub_cmdq_add(sc, cmd);
892 /*
893 * We can call ub_scsi_dispatch(sc) right away here, but it's a little
894 * safer to jump to a tasklet, in case upper layers do something silly.
895 */
896 tasklet_schedule(&sc->tasklet);
897 return 0;
898 }
899
900 /*
901 * Submit the first URB for the queued command.
902 * This function does not deal with queueing in any way.
903 */
904 static int ub_scsi_cmd_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
905 {
906 struct bulk_cb_wrap *bcb;
907 int rc;
908
909 bcb = &sc->work_bcb;
910
911 /*
912 * ``If the allocation length is eighteen or greater, and a device
913 * server returns less than eithteen bytes of data, the application
914 * client should assume that the bytes not transferred would have been
915 * zeroes had the device server returned those bytes.''
916 *
917 * We zero sense for all commands so that when a packet request
918 * fails it does not return a stale sense.
919 */
920 memset(&sc->top_sense, 0, UB_SENSE_SIZE);
921
922 /* set up the command wrapper */
923 bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
924 bcb->Tag = cmd->tag; /* Endianness is not important */
925 bcb->DataTransferLength = cpu_to_le32(cmd->len);
926 bcb->Flags = (cmd->dir == UB_DIR_READ) ? 0x80 : 0;
927 bcb->Lun = (cmd->lun != NULL) ? cmd->lun->num : 0;
928 bcb->Length = cmd->cdb_len;
929
930 /* copy the command payload */
931 memcpy(bcb->CDB, cmd->cdb, UB_MAX_CDB_SIZE);
932
933 UB_INIT_COMPLETION(sc->work_done);
934
935 sc->last_pipe = sc->send_bulk_pipe;
936 usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->send_bulk_pipe,
937 bcb, US_BULK_CB_WRAP_LEN, ub_urb_complete, sc);
938
939 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
940 /* XXX Clear stalls */
941 ub_complete(&sc->work_done);
942 return rc;
943 }
944
945 sc->work_timer.expires = jiffies + UB_URB_TIMEOUT;
946 add_timer(&sc->work_timer);
947
948 cmd->state = UB_CMDST_CMD;
949 return 0;
950 }
951
952 /*
953 * Timeout handler.
954 */
955 static void ub_urb_timeout(unsigned long arg)
956 {
957 struct ub_dev *sc = (struct ub_dev *) arg;
958 unsigned long flags;
959
960 spin_lock_irqsave(sc->lock, flags);
961 if (!ub_is_completed(&sc->work_done))
962 usb_unlink_urb(&sc->work_urb);
963 spin_unlock_irqrestore(sc->lock, flags);
964 }
965
966 /*
967 * Completion routine for the work URB.
968 *
969 * This can be called directly from usb_submit_urb (while we have
970 * the sc->lock taken) and from an interrupt (while we do NOT have
971 * the sc->lock taken). Therefore, bounce this off to a tasklet.
972 */
973 static void ub_urb_complete(struct urb *urb)
974 {
975 struct ub_dev *sc = urb->context;
976
977 ub_complete(&sc->work_done);
978 tasklet_schedule(&sc->tasklet);
979 }
980
981 static void ub_scsi_action(unsigned long _dev)
982 {
983 struct ub_dev *sc = (struct ub_dev *) _dev;
984 unsigned long flags;
985
986 spin_lock_irqsave(sc->lock, flags);
987 ub_scsi_dispatch(sc);
988 spin_unlock_irqrestore(sc->lock, flags);
989 }
990
991 static void ub_scsi_dispatch(struct ub_dev *sc)
992 {
993 struct ub_scsi_cmd *cmd;
994 int rc;
995
996 while (!sc->reset && (cmd = ub_cmdq_peek(sc)) != NULL) {
997 if (cmd->state == UB_CMDST_DONE) {
998 ub_cmdq_pop(sc);
999 (*cmd->done)(sc, cmd);
1000 } else if (cmd->state == UB_CMDST_INIT) {
1001 if ((rc = ub_scsi_cmd_start(sc, cmd)) == 0)
1002 break;
1003 cmd->error = rc;
1004 cmd->state = UB_CMDST_DONE;
1005 } else {
1006 if (!ub_is_completed(&sc->work_done))
1007 break;
1008 del_timer(&sc->work_timer);
1009 ub_scsi_urb_compl(sc, cmd);
1010 }
1011 }
1012 }
1013
1014 static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1015 {
1016 struct urb *urb = &sc->work_urb;
1017 struct bulk_cs_wrap *bcs;
1018 int endp;
1019 int len;
1020 int rc;
1021
1022 if (atomic_read(&sc->poison)) {
1023 ub_state_done(sc, cmd, -ENODEV);
1024 return;
1025 }
1026
1027 endp = usb_pipeendpoint(sc->last_pipe);
1028 if (usb_pipein(sc->last_pipe))
1029 endp |= USB_DIR_IN;
1030
1031 if (cmd->state == UB_CMDST_CLEAR) {
1032 if (urb->status == -EPIPE) {
1033 /*
1034 * STALL while clearning STALL.
1035 * The control pipe clears itself - nothing to do.
1036 */
1037 printk(KERN_NOTICE "%s: stall on control pipe\n",
1038 sc->name);
1039 goto Bad_End;
1040 }
1041
1042 /*
1043 * We ignore the result for the halt clear.
1044 */
1045
1046 usb_reset_endpoint(sc->dev, endp);
1047
1048 ub_state_sense(sc, cmd);
1049
1050 } else if (cmd->state == UB_CMDST_CLR2STS) {
1051 if (urb->status == -EPIPE) {
1052 printk(KERN_NOTICE "%s: stall on control pipe\n",
1053 sc->name);
1054 goto Bad_End;
1055 }
1056
1057 /*
1058 * We ignore the result for the halt clear.
1059 */
1060
1061 usb_reset_endpoint(sc->dev, endp);
1062
1063 ub_state_stat(sc, cmd);
1064
1065 } else if (cmd->state == UB_CMDST_CLRRS) {
1066 if (urb->status == -EPIPE) {
1067 printk(KERN_NOTICE "%s: stall on control pipe\n",
1068 sc->name);
1069 goto Bad_End;
1070 }
1071
1072 /*
1073 * We ignore the result for the halt clear.
1074 */
1075
1076 usb_reset_endpoint(sc->dev, endp);
1077
1078 ub_state_stat_counted(sc, cmd);
1079
1080 } else if (cmd->state == UB_CMDST_CMD) {
1081 switch (urb->status) {
1082 case 0:
1083 break;
1084 case -EOVERFLOW:
1085 goto Bad_End;
1086 case -EPIPE:
1087 rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1088 if (rc != 0) {
1089 printk(KERN_NOTICE "%s: "
1090 "unable to submit clear (%d)\n",
1091 sc->name, rc);
1092 /*
1093 * This is typically ENOMEM or some other such shit.
1094 * Retrying is pointless. Just do Bad End on it...
1095 */
1096 ub_state_done(sc, cmd, rc);
1097 return;
1098 }
1099 cmd->state = UB_CMDST_CLEAR;
1100 return;
1101 case -ESHUTDOWN: /* unplug */
1102 case -EILSEQ: /* unplug timeout on uhci */
1103 ub_state_done(sc, cmd, -ENODEV);
1104 return;
1105 default:
1106 goto Bad_End;
1107 }
1108 if (urb->actual_length != US_BULK_CB_WRAP_LEN) {
1109 goto Bad_End;
1110 }
1111
1112 if (cmd->dir == UB_DIR_NONE || cmd->nsg < 1) {
1113 ub_state_stat(sc, cmd);
1114 return;
1115 }
1116
1117 // udelay(125); // usb-storage has this
1118 ub_data_start(sc, cmd);
1119
1120 } else if (cmd->state == UB_CMDST_DATA) {
1121 if (urb->status == -EPIPE) {
1122 rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1123 if (rc != 0) {
1124 printk(KERN_NOTICE "%s: "
1125 "unable to submit clear (%d)\n",
1126 sc->name, rc);
1127 ub_state_done(sc, cmd, rc);
1128 return;
1129 }
1130 cmd->state = UB_CMDST_CLR2STS;
1131 return;
1132 }
1133 if (urb->status == -EOVERFLOW) {
1134 /*
1135 * A babble? Failure, but we must transfer CSW now.
1136 */
1137 cmd->error = -EOVERFLOW; /* A cheap trick... */
1138 ub_state_stat(sc, cmd);
1139 return;
1140 }
1141
1142 if (cmd->dir == UB_DIR_WRITE) {
1143 /*
1144 * Do not continue writes in case of a failure.
1145 * Doing so would cause sectors to be mixed up,
1146 * which is worse than sectors lost.
1147 *
1148 * We must try to read the CSW, or many devices
1149 * get confused.
1150 */
1151 len = urb->actual_length;
1152 if (urb->status != 0 ||
1153 len != cmd->sgv[cmd->current_sg].length) {
1154 cmd->act_len += len;
1155
1156 cmd->error = -EIO;
1157 ub_state_stat(sc, cmd);
1158 return;
1159 }
1160
1161 } else {
1162 /*
1163 * If an error occurs on read, we record it, and
1164 * continue to fetch data in order to avoid bubble.
1165 *
1166 * As a small shortcut, we stop if we detect that
1167 * a CSW mixed into data.
1168 */
1169 if (urb->status != 0)
1170 cmd->error = -EIO;
1171
1172 len = urb->actual_length;
1173 if (urb->status != 0 ||
1174 len != cmd->sgv[cmd->current_sg].length) {
1175 if ((len & 0x1FF) == US_BULK_CS_WRAP_LEN)
1176 goto Bad_End;
1177 }
1178 }
1179
1180 cmd->act_len += urb->actual_length;
1181
1182 if (++cmd->current_sg < cmd->nsg) {
1183 ub_data_start(sc, cmd);
1184 return;
1185 }
1186 ub_state_stat(sc, cmd);
1187
1188 } else if (cmd->state == UB_CMDST_STAT) {
1189 if (urb->status == -EPIPE) {
1190 rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1191 if (rc != 0) {
1192 printk(KERN_NOTICE "%s: "
1193 "unable to submit clear (%d)\n",
1194 sc->name, rc);
1195 ub_state_done(sc, cmd, rc);
1196 return;
1197 }
1198
1199 /*
1200 * Having a stall when getting CSW is an error, so
1201 * make sure uppper levels are not oblivious to it.
1202 */
1203 cmd->error = -EIO; /* A cheap trick... */
1204
1205 cmd->state = UB_CMDST_CLRRS;
1206 return;
1207 }
1208
1209 /* Catch everything, including -EOVERFLOW and other nasties. */
1210 if (urb->status != 0)
1211 goto Bad_End;
1212
1213 if (urb->actual_length == 0) {
1214 ub_state_stat_counted(sc, cmd);
1215 return;
1216 }
1217
1218 /*
1219 * Check the returned Bulk protocol status.
1220 * The status block has to be validated first.
1221 */
1222
1223 bcs = &sc->work_bcs;
1224
1225 if (sc->signature == cpu_to_le32(0)) {
1226 /*
1227 * This is the first reply, so do not perform the check.
1228 * Instead, remember the signature the device uses
1229 * for future checks. But do not allow a nul.
1230 */
1231 sc->signature = bcs->Signature;
1232 if (sc->signature == cpu_to_le32(0)) {
1233 ub_state_stat_counted(sc, cmd);
1234 return;
1235 }
1236 } else {
1237 if (bcs->Signature != sc->signature) {
1238 ub_state_stat_counted(sc, cmd);
1239 return;
1240 }
1241 }
1242
1243 if (bcs->Tag != cmd->tag) {
1244 /*
1245 * This usually happens when we disagree with the
1246 * device's microcode about something. For instance,
1247 * a few of them throw this after timeouts. They buffer
1248 * commands and reply at commands we timed out before.
1249 * Without flushing these replies we loop forever.
1250 */
1251 ub_state_stat_counted(sc, cmd);
1252 return;
1253 }
1254
1255 if (!sc->bad_resid) {
1256 len = le32_to_cpu(bcs->Residue);
1257 if (len != cmd->len - cmd->act_len) {
1258 /*
1259 * Only start ignoring if this cmd ended well.
1260 */
1261 if (cmd->len == cmd->act_len) {
1262 printk(KERN_NOTICE "%s: "
1263 "bad residual %d of %d, ignoring\n",
1264 sc->name, len, cmd->len);
1265 sc->bad_resid = 1;
1266 }
1267 }
1268 }
1269
1270 switch (bcs->Status) {
1271 case US_BULK_STAT_OK:
1272 break;
1273 case US_BULK_STAT_FAIL:
1274 ub_state_sense(sc, cmd);
1275 return;
1276 case US_BULK_STAT_PHASE:
1277 goto Bad_End;
1278 default:
1279 printk(KERN_INFO "%s: unknown CSW status 0x%x\n",
1280 sc->name, bcs->Status);
1281 ub_state_done(sc, cmd, -EINVAL);
1282 return;
1283 }
1284
1285 /* Not zeroing error to preserve a babble indicator */
1286 if (cmd->error != 0) {
1287 ub_state_sense(sc, cmd);
1288 return;
1289 }
1290 cmd->state = UB_CMDST_DONE;
1291 ub_cmdq_pop(sc);
1292 (*cmd->done)(sc, cmd);
1293
1294 } else if (cmd->state == UB_CMDST_SENSE) {
1295 ub_state_done(sc, cmd, -EIO);
1296
1297 } else {
1298 printk(KERN_WARNING "%s: wrong command state %d\n",
1299 sc->name, cmd->state);
1300 ub_state_done(sc, cmd, -EINVAL);
1301 return;
1302 }
1303 return;
1304
1305 Bad_End: /* Little Excel is dead */
1306 ub_state_done(sc, cmd, -EIO);
1307 }
1308
1309 /*
1310 * Factorization helper for the command state machine:
1311 * Initiate a data segment transfer.
1312 */
1313 static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1314 {
1315 struct scatterlist *sg = &cmd->sgv[cmd->current_sg];
1316 int pipe;
1317 int rc;
1318
1319 UB_INIT_COMPLETION(sc->work_done);
1320
1321 if (cmd->dir == UB_DIR_READ)
1322 pipe = sc->recv_bulk_pipe;
1323 else
1324 pipe = sc->send_bulk_pipe;
1325 sc->last_pipe = pipe;
1326 usb_fill_bulk_urb(&sc->work_urb, sc->dev, pipe, sg_virt(sg),
1327 sg->length, ub_urb_complete, sc);
1328
1329 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1330 /* XXX Clear stalls */
1331 ub_complete(&sc->work_done);
1332 ub_state_done(sc, cmd, rc);
1333 return;
1334 }
1335
1336 if (cmd->timeo)
1337 sc->work_timer.expires = jiffies + cmd->timeo;
1338 else
1339 sc->work_timer.expires = jiffies + UB_DATA_TIMEOUT;
1340 add_timer(&sc->work_timer);
1341
1342 cmd->state = UB_CMDST_DATA;
1343 }
1344
1345 /*
1346 * Factorization helper for the command state machine:
1347 * Finish the command.
1348 */
1349 static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc)
1350 {
1351
1352 cmd->error = rc;
1353 cmd->state = UB_CMDST_DONE;
1354 ub_cmdq_pop(sc);
1355 (*cmd->done)(sc, cmd);
1356 }
1357
1358 /*
1359 * Factorization helper for the command state machine:
1360 * Submit a CSW read.
1361 */
1362 static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1363 {
1364 int rc;
1365
1366 UB_INIT_COMPLETION(sc->work_done);
1367
1368 sc->last_pipe = sc->recv_bulk_pipe;
1369 usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->recv_bulk_pipe,
1370 &sc->work_bcs, US_BULK_CS_WRAP_LEN, ub_urb_complete, sc);
1371
1372 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1373 /* XXX Clear stalls */
1374 ub_complete(&sc->work_done);
1375 ub_state_done(sc, cmd, rc);
1376 return -1;
1377 }
1378
1379 if (cmd->timeo)
1380 sc->work_timer.expires = jiffies + cmd->timeo;
1381 else
1382 sc->work_timer.expires = jiffies + UB_STAT_TIMEOUT;
1383 add_timer(&sc->work_timer);
1384 return 0;
1385 }
1386
1387 /*
1388 * Factorization helper for the command state machine:
1389 * Submit a CSW read and go to STAT state.
1390 */
1391 static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1392 {
1393
1394 if (__ub_state_stat(sc, cmd) != 0)
1395 return;
1396
1397 cmd->stat_count = 0;
1398 cmd->state = UB_CMDST_STAT;
1399 }
1400
1401 /*
1402 * Factorization helper for the command state machine:
1403 * Submit a CSW read and go to STAT state with counter (along [C] path).
1404 */
1405 static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1406 {
1407
1408 if (++cmd->stat_count >= 4) {
1409 ub_state_sense(sc, cmd);
1410 return;
1411 }
1412
1413 if (__ub_state_stat(sc, cmd) != 0)
1414 return;
1415
1416 cmd->state = UB_CMDST_STAT;
1417 }
1418
1419 /*
1420 * Factorization helper for the command state machine:
1421 * Submit a REQUEST SENSE and go to SENSE state.
1422 */
1423 static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1424 {
1425 struct ub_scsi_cmd *scmd;
1426 struct scatterlist *sg;
1427 int rc;
1428
1429 if (cmd->cdb[0] == REQUEST_SENSE) {
1430 rc = -EPIPE;
1431 goto error;
1432 }
1433
1434 scmd = &sc->top_rqs_cmd;
1435 memset(scmd, 0, sizeof(struct ub_scsi_cmd));
1436 scmd->cdb[0] = REQUEST_SENSE;
1437 scmd->cdb[4] = UB_SENSE_SIZE;
1438 scmd->cdb_len = 6;
1439 scmd->dir = UB_DIR_READ;
1440 scmd->state = UB_CMDST_INIT;
1441 scmd->nsg = 1;
1442 sg = &scmd->sgv[0];
1443 sg_init_table(sg, UB_MAX_REQ_SG);
1444 sg_set_page(sg, virt_to_page(sc->top_sense), UB_SENSE_SIZE,
1445 (unsigned long)sc->top_sense & (PAGE_SIZE-1));
1446 scmd->len = UB_SENSE_SIZE;
1447 scmd->lun = cmd->lun;
1448 scmd->done = ub_top_sense_done;
1449 scmd->back = cmd;
1450
1451 scmd->tag = sc->tagcnt++;
1452
1453 cmd->state = UB_CMDST_SENSE;
1454
1455 ub_cmdq_insert(sc, scmd);
1456 return;
1457
1458 error:
1459 ub_state_done(sc, cmd, rc);
1460 }
1461
1462 /*
1463 * A helper for the command's state machine:
1464 * Submit a stall clear.
1465 */
1466 static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
1467 int stalled_pipe)
1468 {
1469 int endp;
1470 struct usb_ctrlrequest *cr;
1471 int rc;
1472
1473 endp = usb_pipeendpoint(stalled_pipe);
1474 if (usb_pipein (stalled_pipe))
1475 endp |= USB_DIR_IN;
1476
1477 cr = &sc->work_cr;
1478 cr->bRequestType = USB_RECIP_ENDPOINT;
1479 cr->bRequest = USB_REQ_CLEAR_FEATURE;
1480 cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
1481 cr->wIndex = cpu_to_le16(endp);
1482 cr->wLength = cpu_to_le16(0);
1483
1484 UB_INIT_COMPLETION(sc->work_done);
1485
1486 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
1487 (unsigned char*) cr, NULL, 0, ub_urb_complete, sc);
1488
1489 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1490 ub_complete(&sc->work_done);
1491 return rc;
1492 }
1493
1494 sc->work_timer.expires = jiffies + UB_CTRL_TIMEOUT;
1495 add_timer(&sc->work_timer);
1496 return 0;
1497 }
1498
1499 /*
1500 */
1501 static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd)
1502 {
1503 unsigned char *sense = sc->top_sense;
1504 struct ub_scsi_cmd *cmd;
1505
1506 /*
1507 * Find the command which triggered the unit attention or a check,
1508 * save the sense into it, and advance its state machine.
1509 */
1510 if ((cmd = ub_cmdq_peek(sc)) == NULL) {
1511 printk(KERN_WARNING "%s: sense done while idle\n", sc->name);
1512 return;
1513 }
1514 if (cmd != scmd->back) {
1515 printk(KERN_WARNING "%s: "
1516 "sense done for wrong command 0x%x\n",
1517 sc->name, cmd->tag);
1518 return;
1519 }
1520 if (cmd->state != UB_CMDST_SENSE) {
1521 printk(KERN_WARNING "%s: sense done with bad cmd state %d\n",
1522 sc->name, cmd->state);
1523 return;
1524 }
1525
1526 /*
1527 * Ignoring scmd->act_len, because the buffer was pre-zeroed.
1528 */
1529 cmd->key = sense[2] & 0x0F;
1530 cmd->asc = sense[12];
1531 cmd->ascq = sense[13];
1532
1533 ub_scsi_urb_compl(sc, cmd);
1534 }
1535
1536 /*
1537 * Reset management
1538 */
1539
1540 static void ub_reset_enter(struct ub_dev *sc, int try)
1541 {
1542
1543 if (sc->reset) {
1544 /* This happens often on multi-LUN devices. */
1545 return;
1546 }
1547 sc->reset = try + 1;
1548
1549 #if 0 /* Not needed because the disconnect waits for us. */
1550 unsigned long flags;
1551 spin_lock_irqsave(&ub_lock, flags);
1552 sc->openc++;
1553 spin_unlock_irqrestore(&ub_lock, flags);
1554 #endif
1555
1556 #if 0 /* We let them stop themselves. */
1557 struct ub_lun *lun;
1558 list_for_each_entry(lun, &sc->luns, link) {
1559 blk_stop_queue(lun->disk->queue);
1560 }
1561 #endif
1562
1563 schedule_work(&sc->reset_work);
1564 }
1565
1566 static void ub_reset_task(struct work_struct *work)
1567 {
1568 struct ub_dev *sc = container_of(work, struct ub_dev, reset_work);
1569 unsigned long flags;
1570 struct ub_lun *lun;
1571 int rc;
1572
1573 if (!sc->reset) {
1574 printk(KERN_WARNING "%s: Running reset unrequested\n",
1575 sc->name);
1576 return;
1577 }
1578
1579 if (atomic_read(&sc->poison)) {
1580 ;
1581 } else if ((sc->reset & 1) == 0) {
1582 ub_sync_reset(sc);
1583 msleep(700); /* usb-storage sleeps 6s (!) */
1584 ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
1585 ub_probe_clear_stall(sc, sc->send_bulk_pipe);
1586 } else if (sc->dev->actconfig->desc.bNumInterfaces != 1) {
1587 ;
1588 } else {
1589 rc = usb_lock_device_for_reset(sc->dev, sc->intf);
1590 if (rc < 0) {
1591 printk(KERN_NOTICE
1592 "%s: usb_lock_device_for_reset failed (%d)\n",
1593 sc->name, rc);
1594 } else {
1595 rc = usb_reset_device(sc->dev);
1596 if (rc < 0) {
1597 printk(KERN_NOTICE "%s: "
1598 "usb_lock_device_for_reset failed (%d)\n",
1599 sc->name, rc);
1600 }
1601 usb_unlock_device(sc->dev);
1602 }
1603 }
1604
1605 /*
1606 * In theory, no commands can be running while reset is active,
1607 * so nobody can ask for another reset, and so we do not need any
1608 * queues of resets or anything. We do need a spinlock though,
1609 * to interact with block layer.
1610 */
1611 spin_lock_irqsave(sc->lock, flags);
1612 sc->reset = 0;
1613 tasklet_schedule(&sc->tasklet);
1614 list_for_each_entry(lun, &sc->luns, link) {
1615 blk_start_queue(lun->disk->queue);
1616 }
1617 wake_up(&sc->reset_wait);
1618 spin_unlock_irqrestore(sc->lock, flags);
1619 }
1620
1621 /*
1622 * XXX Reset brackets are too much hassle to implement, so just stub them
1623 * in order to prevent forced unbinding (which deadlocks solid when our
1624 * ->disconnect method waits for the reset to complete and this kills keventd).
1625 *
1626 * XXX Tell Alan to move usb_unlock_device inside of usb_reset_device,
1627 * or else the post_reset is invoked, and restats I/O on a locked device.
1628 */
1629 static int ub_pre_reset(struct usb_interface *iface) {
1630 return 0;
1631 }
1632
1633 static int ub_post_reset(struct usb_interface *iface) {
1634 return 0;
1635 }
1636
1637 /*
1638 * This is called from a process context.
1639 */
1640 static void ub_revalidate(struct ub_dev *sc, struct ub_lun *lun)
1641 {
1642
1643 lun->readonly = 0; /* XXX Query this from the device */
1644
1645 lun->capacity.nsec = 0;
1646 lun->capacity.bsize = 512;
1647 lun->capacity.bshift = 0;
1648
1649 if (ub_sync_tur(sc, lun) != 0)
1650 return; /* Not ready */
1651 lun->changed = 0;
1652
1653 if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
1654 /*
1655 * The retry here means something is wrong, either with the
1656 * device, with the transport, or with our code.
1657 * We keep this because sd.c has retries for capacity.
1658 */
1659 if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
1660 lun->capacity.nsec = 0;
1661 lun->capacity.bsize = 512;
1662 lun->capacity.bshift = 0;
1663 }
1664 }
1665 }
1666
1667 /*
1668 * The open funcion.
1669 * This is mostly needed to keep refcounting, but also to support
1670 * media checks on removable media drives.
1671 */
1672 static int ub_bd_open(struct block_device *bdev, fmode_t mode)
1673 {
1674 struct ub_lun *lun = bdev->bd_disk->private_data;
1675 struct ub_dev *sc = lun->udev;
1676 unsigned long flags;
1677 int rc;
1678
1679 spin_lock_irqsave(&ub_lock, flags);
1680 if (atomic_read(&sc->poison)) {
1681 spin_unlock_irqrestore(&ub_lock, flags);
1682 return -ENXIO;
1683 }
1684 sc->openc++;
1685 spin_unlock_irqrestore(&ub_lock, flags);
1686
1687 if (lun->removable || lun->readonly)
1688 check_disk_change(bdev);
1689
1690 /*
1691 * The sd.c considers ->media_present and ->changed not equivalent,
1692 * under some pretty murky conditions (a failure of READ CAPACITY).
1693 * We may need it one day.
1694 */
1695 if (lun->removable && lun->changed && !(mode & FMODE_NDELAY)) {
1696 rc = -ENOMEDIUM;
1697 goto err_open;
1698 }
1699
1700 if (lun->readonly && (mode & FMODE_WRITE)) {
1701 rc = -EROFS;
1702 goto err_open;
1703 }
1704
1705 return 0;
1706
1707 err_open:
1708 ub_put(sc);
1709 return rc;
1710 }
1711
1712 /*
1713 */
1714 static int ub_bd_release(struct gendisk *disk, fmode_t mode)
1715 {
1716 struct ub_lun *lun = disk->private_data;
1717 struct ub_dev *sc = lun->udev;
1718
1719 ub_put(sc);
1720 return 0;
1721 }
1722
1723 /*
1724 * The ioctl interface.
1725 */
1726 static int ub_bd_ioctl(struct block_device *bdev, fmode_t mode,
1727 unsigned int cmd, unsigned long arg)
1728 {
1729 struct gendisk *disk = bdev->bd_disk;
1730 void __user *usermem = (void __user *) arg;
1731
1732 return scsi_cmd_ioctl(disk->queue, disk, mode, cmd, usermem);
1733 }
1734
1735 /*
1736 * This is called by check_disk_change if we reported a media change.
1737 * The main onjective here is to discover the features of the media such as
1738 * the capacity, read-only status, etc. USB storage generally does not
1739 * need to be spun up, but if we needed it, this would be the place.
1740 *
1741 * This call can sleep.
1742 *
1743 * The return code is not used.
1744 */
1745 static int ub_bd_revalidate(struct gendisk *disk)
1746 {
1747 struct ub_lun *lun = disk->private_data;
1748
1749 ub_revalidate(lun->udev, lun);
1750
1751 /* XXX Support sector size switching like in sr.c */
1752 blk_queue_logical_block_size(disk->queue, lun->capacity.bsize);
1753 set_capacity(disk, lun->capacity.nsec);
1754 // set_disk_ro(sdkp->disk, lun->readonly);
1755
1756 return 0;
1757 }
1758
1759 /*
1760 * The check is called by the block layer to verify if the media
1761 * is still available. It is supposed to be harmless, lightweight and
1762 * non-intrusive in case the media was not changed.
1763 *
1764 * This call can sleep.
1765 *
1766 * The return code is bool!
1767 */
1768 static int ub_bd_media_changed(struct gendisk *disk)
1769 {
1770 struct ub_lun *lun = disk->private_data;
1771
1772 if (!lun->removable)
1773 return 0;
1774
1775 /*
1776 * We clean checks always after every command, so this is not
1777 * as dangerous as it looks. If the TEST_UNIT_READY fails here,
1778 * the device is actually not ready with operator or software
1779 * intervention required. One dangerous item might be a drive which
1780 * spins itself down, and come the time to write dirty pages, this
1781 * will fail, then block layer discards the data. Since we never
1782 * spin drives up, such devices simply cannot be used with ub anyway.
1783 */
1784 if (ub_sync_tur(lun->udev, lun) != 0) {
1785 lun->changed = 1;
1786 return 1;
1787 }
1788
1789 return lun->changed;
1790 }
1791
1792 static struct block_device_operations ub_bd_fops = {
1793 .owner = THIS_MODULE,
1794 .open = ub_bd_open,
1795 .release = ub_bd_release,
1796 .locked_ioctl = ub_bd_ioctl,
1797 .media_changed = ub_bd_media_changed,
1798 .revalidate_disk = ub_bd_revalidate,
1799 };
1800
1801 /*
1802 * Common ->done routine for commands executed synchronously.
1803 */
1804 static void ub_probe_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1805 {
1806 struct completion *cop = cmd->back;
1807 complete(cop);
1808 }
1809
1810 /*
1811 * Test if the device has a check condition on it, synchronously.
1812 */
1813 static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun)
1814 {
1815 struct ub_scsi_cmd *cmd;
1816 enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) };
1817 unsigned long flags;
1818 struct completion compl;
1819 int rc;
1820
1821 init_completion(&compl);
1822
1823 rc = -ENOMEM;
1824 if ((cmd = kzalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
1825 goto err_alloc;
1826
1827 cmd->cdb[0] = TEST_UNIT_READY;
1828 cmd->cdb_len = 6;
1829 cmd->dir = UB_DIR_NONE;
1830 cmd->state = UB_CMDST_INIT;
1831 cmd->lun = lun; /* This may be NULL, but that's ok */
1832 cmd->done = ub_probe_done;
1833 cmd->back = &compl;
1834
1835 spin_lock_irqsave(sc->lock, flags);
1836 cmd->tag = sc->tagcnt++;
1837
1838 rc = ub_submit_scsi(sc, cmd);
1839 spin_unlock_irqrestore(sc->lock, flags);
1840
1841 if (rc != 0)
1842 goto err_submit;
1843
1844 wait_for_completion(&compl);
1845
1846 rc = cmd->error;
1847
1848 if (rc == -EIO && cmd->key != 0) /* Retries for benh's key */
1849 rc = cmd->key;
1850
1851 err_submit:
1852 kfree(cmd);
1853 err_alloc:
1854 return rc;
1855 }
1856
1857 /*
1858 * Read the SCSI capacity synchronously (for probing).
1859 */
1860 static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
1861 struct ub_capacity *ret)
1862 {
1863 struct ub_scsi_cmd *cmd;
1864 struct scatterlist *sg;
1865 char *p;
1866 enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) + 8 };
1867 unsigned long flags;
1868 unsigned int bsize, shift;
1869 unsigned long nsec;
1870 struct completion compl;
1871 int rc;
1872
1873 init_completion(&compl);
1874
1875 rc = -ENOMEM;
1876 if ((cmd = kzalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
1877 goto err_alloc;
1878 p = (char *)cmd + sizeof(struct ub_scsi_cmd);
1879
1880 cmd->cdb[0] = 0x25;
1881 cmd->cdb_len = 10;
1882 cmd->dir = UB_DIR_READ;
1883 cmd->state = UB_CMDST_INIT;
1884 cmd->nsg = 1;
1885 sg = &cmd->sgv[0];
1886 sg_init_table(sg, UB_MAX_REQ_SG);
1887 sg_set_page(sg, virt_to_page(p), 8, (unsigned long)p & (PAGE_SIZE-1));
1888 cmd->len = 8;
1889 cmd->lun = lun;
1890 cmd->done = ub_probe_done;
1891 cmd->back = &compl;
1892
1893 spin_lock_irqsave(sc->lock, flags);
1894 cmd->tag = sc->tagcnt++;
1895
1896 rc = ub_submit_scsi(sc, cmd);
1897 spin_unlock_irqrestore(sc->lock, flags);
1898
1899 if (rc != 0)
1900 goto err_submit;
1901
1902 wait_for_completion(&compl);
1903
1904 if (cmd->error != 0) {
1905 rc = -EIO;
1906 goto err_read;
1907 }
1908 if (cmd->act_len != 8) {
1909 rc = -EIO;
1910 goto err_read;
1911 }
1912
1913 /* sd.c special-cases sector size of 0 to mean 512. Needed? Safe? */
1914 nsec = be32_to_cpu(*(__be32 *)p) + 1;
1915 bsize = be32_to_cpu(*(__be32 *)(p + 4));
1916 switch (bsize) {
1917 case 512: shift = 0; break;
1918 case 1024: shift = 1; break;
1919 case 2048: shift = 2; break;
1920 case 4096: shift = 3; break;
1921 default:
1922 rc = -EDOM;
1923 goto err_inv_bsize;
1924 }
1925
1926 ret->bsize = bsize;
1927 ret->bshift = shift;
1928 ret->nsec = nsec << shift;
1929 rc = 0;
1930
1931 err_inv_bsize:
1932 err_read:
1933 err_submit:
1934 kfree(cmd);
1935 err_alloc:
1936 return rc;
1937 }
1938
1939 /*
1940 */
1941 static void ub_probe_urb_complete(struct urb *urb)
1942 {
1943 struct completion *cop = urb->context;
1944 complete(cop);
1945 }
1946
1947 static void ub_probe_timeout(unsigned long arg)
1948 {
1949 struct completion *cop = (struct completion *) arg;
1950 complete(cop);
1951 }
1952
1953 /*
1954 * Reset with a Bulk reset.
1955 */
1956 static int ub_sync_reset(struct ub_dev *sc)
1957 {
1958 int ifnum = sc->intf->cur_altsetting->desc.bInterfaceNumber;
1959 struct usb_ctrlrequest *cr;
1960 struct completion compl;
1961 struct timer_list timer;
1962 int rc;
1963
1964 init_completion(&compl);
1965
1966 cr = &sc->work_cr;
1967 cr->bRequestType = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
1968 cr->bRequest = US_BULK_RESET_REQUEST;
1969 cr->wValue = cpu_to_le16(0);
1970 cr->wIndex = cpu_to_le16(ifnum);
1971 cr->wLength = cpu_to_le16(0);
1972
1973 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
1974 (unsigned char*) cr, NULL, 0, ub_probe_urb_complete, &compl);
1975
1976 if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
1977 printk(KERN_WARNING
1978 "%s: Unable to submit a bulk reset (%d)\n", sc->name, rc);
1979 return rc;
1980 }
1981
1982 init_timer(&timer);
1983 timer.function = ub_probe_timeout;
1984 timer.data = (unsigned long) &compl;
1985 timer.expires = jiffies + UB_CTRL_TIMEOUT;
1986 add_timer(&timer);
1987
1988 wait_for_completion(&compl);
1989
1990 del_timer_sync(&timer);
1991 usb_kill_urb(&sc->work_urb);
1992
1993 return sc->work_urb.status;
1994 }
1995
1996 /*
1997 * Get number of LUNs by the way of Bulk GetMaxLUN command.
1998 */
1999 static int ub_sync_getmaxlun(struct ub_dev *sc)
2000 {
2001 int ifnum = sc->intf->cur_altsetting->desc.bInterfaceNumber;
2002 unsigned char *p;
2003 enum { ALLOC_SIZE = 1 };
2004 struct usb_ctrlrequest *cr;
2005 struct completion compl;
2006 struct timer_list timer;
2007 int nluns;
2008 int rc;
2009
2010 init_completion(&compl);
2011
2012 rc = -ENOMEM;
2013 if ((p = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
2014 goto err_alloc;
2015 *p = 55;
2016
2017 cr = &sc->work_cr;
2018 cr->bRequestType = USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE;
2019 cr->bRequest = US_BULK_GET_MAX_LUN;
2020 cr->wValue = cpu_to_le16(0);
2021 cr->wIndex = cpu_to_le16(ifnum);
2022 cr->wLength = cpu_to_le16(1);
2023
2024 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->recv_ctrl_pipe,
2025 (unsigned char*) cr, p, 1, ub_probe_urb_complete, &compl);
2026
2027 if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0)
2028 goto err_submit;
2029
2030 init_timer(&timer);
2031 timer.function = ub_probe_timeout;
2032 timer.data = (unsigned long) &compl;
2033 timer.expires = jiffies + UB_CTRL_TIMEOUT;
2034 add_timer(&timer);
2035
2036 wait_for_completion(&compl);
2037
2038 del_timer_sync(&timer);
2039 usb_kill_urb(&sc->work_urb);
2040
2041 if ((rc = sc->work_urb.status) < 0)
2042 goto err_io;
2043
2044 if (sc->work_urb.actual_length != 1) {
2045 nluns = 0;
2046 } else {
2047 if ((nluns = *p) == 55) {
2048 nluns = 0;
2049 } else {
2050 /* GetMaxLUN returns the maximum LUN number */
2051 nluns += 1;
2052 if (nluns > UB_MAX_LUNS)
2053 nluns = UB_MAX_LUNS;
2054 }
2055 }
2056
2057 kfree(p);
2058 return nluns;
2059
2060 err_io:
2061 err_submit:
2062 kfree(p);
2063 err_alloc:
2064 return rc;
2065 }
2066
2067 /*
2068 * Clear initial stalls.
2069 */
2070 static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe)
2071 {
2072 int endp;
2073 struct usb_ctrlrequest *cr;
2074 struct completion compl;
2075 struct timer_list timer;
2076 int rc;
2077
2078 init_completion(&compl);
2079
2080 endp = usb_pipeendpoint(stalled_pipe);
2081 if (usb_pipein (stalled_pipe))
2082 endp |= USB_DIR_IN;
2083
2084 cr = &sc->work_cr;
2085 cr->bRequestType = USB_RECIP_ENDPOINT;
2086 cr->bRequest = USB_REQ_CLEAR_FEATURE;
2087 cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
2088 cr->wIndex = cpu_to_le16(endp);
2089 cr->wLength = cpu_to_le16(0);
2090
2091 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
2092 (unsigned char*) cr, NULL, 0, ub_probe_urb_complete, &compl);
2093
2094 if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
2095 printk(KERN_WARNING
2096 "%s: Unable to submit a probe clear (%d)\n", sc->name, rc);
2097 return rc;
2098 }
2099
2100 init_timer(&timer);
2101 timer.function = ub_probe_timeout;
2102 timer.data = (unsigned long) &compl;
2103 timer.expires = jiffies + UB_CTRL_TIMEOUT;
2104 add_timer(&timer);
2105
2106 wait_for_completion(&compl);
2107
2108 del_timer_sync(&timer);
2109 usb_kill_urb(&sc->work_urb);
2110
2111 usb_reset_endpoint(sc->dev, endp);
2112
2113 return 0;
2114 }
2115
2116 /*
2117 * Get the pipe settings.
2118 */
2119 static int ub_get_pipes(struct ub_dev *sc, struct usb_device *dev,
2120 struct usb_interface *intf)
2121 {
2122 struct usb_host_interface *altsetting = intf->cur_altsetting;
2123 struct usb_endpoint_descriptor *ep_in = NULL;
2124 struct usb_endpoint_descriptor *ep_out = NULL;
2125 struct usb_endpoint_descriptor *ep;
2126 int i;
2127
2128 /*
2129 * Find the endpoints we need.
2130 * We are expecting a minimum of 2 endpoints - in and out (bulk).
2131 * We will ignore any others.
2132 */
2133 for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
2134 ep = &altsetting->endpoint[i].desc;
2135
2136 /* Is it a BULK endpoint? */
2137 if (usb_endpoint_xfer_bulk(ep)) {
2138 /* BULK in or out? */
2139 if (usb_endpoint_dir_in(ep)) {
2140 if (ep_in == NULL)
2141 ep_in = ep;
2142 } else {
2143 if (ep_out == NULL)
2144 ep_out = ep;
2145 }
2146 }
2147 }
2148
2149 if (ep_in == NULL || ep_out == NULL) {
2150 printk(KERN_NOTICE "%s: failed endpoint check\n", sc->name);
2151 return -ENODEV;
2152 }
2153
2154 /* Calculate and store the pipe values */
2155 sc->send_ctrl_pipe = usb_sndctrlpipe(dev, 0);
2156 sc->recv_ctrl_pipe = usb_rcvctrlpipe(dev, 0);
2157 sc->send_bulk_pipe = usb_sndbulkpipe(dev,
2158 usb_endpoint_num(ep_out));
2159 sc->recv_bulk_pipe = usb_rcvbulkpipe(dev,
2160 usb_endpoint_num(ep_in));
2161
2162 return 0;
2163 }
2164
2165 /*
2166 * Probing is done in the process context, which allows us to cheat
2167 * and not to build a state machine for the discovery.
2168 */
2169 static int ub_probe(struct usb_interface *intf,
2170 const struct usb_device_id *dev_id)
2171 {
2172 struct ub_dev *sc;
2173 int nluns;
2174 int rc;
2175 int i;
2176
2177 if (usb_usual_check_type(dev_id, USB_US_TYPE_UB))
2178 return -ENXIO;
2179
2180 rc = -ENOMEM;
2181 if ((sc = kzalloc(sizeof(struct ub_dev), GFP_KERNEL)) == NULL)
2182 goto err_core;
2183 sc->lock = ub_next_lock();
2184 INIT_LIST_HEAD(&sc->luns);
2185 usb_init_urb(&sc->work_urb);
2186 tasklet_init(&sc->tasklet, ub_scsi_action, (unsigned long)sc);
2187 atomic_set(&sc->poison, 0);
2188 INIT_WORK(&sc->reset_work, ub_reset_task);
2189 init_waitqueue_head(&sc->reset_wait);
2190
2191 init_timer(&sc->work_timer);
2192 sc->work_timer.data = (unsigned long) sc;
2193 sc->work_timer.function = ub_urb_timeout;
2194
2195 ub_init_completion(&sc->work_done);
2196 sc->work_done.done = 1; /* A little yuk, but oh well... */
2197
2198 sc->dev = interface_to_usbdev(intf);
2199 sc->intf = intf;
2200 // sc->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
2201 usb_set_intfdata(intf, sc);
2202 usb_get_dev(sc->dev);
2203 /*
2204 * Since we give the interface struct to the block level through
2205 * disk->driverfs_dev, we have to pin it. Otherwise, block_uevent
2206 * oopses on close after a disconnect (kernels 2.6.16 and up).
2207 */
2208 usb_get_intf(sc->intf);
2209
2210 snprintf(sc->name, 12, DRV_NAME "(%d.%d)",
2211 sc->dev->bus->busnum, sc->dev->devnum);
2212
2213 /* XXX Verify that we can handle the device (from descriptors) */
2214
2215 if (ub_get_pipes(sc, sc->dev, intf) != 0)
2216 goto err_dev_desc;
2217
2218 /*
2219 * At this point, all USB initialization is done, do upper layer.
2220 * We really hate halfway initialized structures, so from the
2221 * invariants perspective, this ub_dev is fully constructed at
2222 * this point.
2223 */
2224
2225 /*
2226 * This is needed to clear toggles. It is a problem only if we do
2227 * `rmmod ub && modprobe ub` without disconnects, but we like that.
2228 */
2229 #if 0 /* iPod Mini fails if we do this (big white iPod works) */
2230 ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
2231 ub_probe_clear_stall(sc, sc->send_bulk_pipe);
2232 #endif
2233
2234 /*
2235 * The way this is used by the startup code is a little specific.
2236 * A SCSI check causes a USB stall. Our common case code sees it
2237 * and clears the check, after which the device is ready for use.
2238 * But if a check was not present, any command other than
2239 * TEST_UNIT_READY ends with a lockup (including REQUEST_SENSE).
2240 *
2241 * If we neglect to clear the SCSI check, the first real command fails
2242 * (which is the capacity readout). We clear that and retry, but why
2243 * causing spurious retries for no reason.
2244 *
2245 * Revalidation may start with its own TEST_UNIT_READY, but that one
2246 * has to succeed, so we clear checks with an additional one here.
2247 * In any case it's not our business how revaliadation is implemented.
2248 */
2249 for (i = 0; i < 3; i++) { /* Retries for the schwag key from KS'04 */
2250 if ((rc = ub_sync_tur(sc, NULL)) <= 0) break;
2251 if (rc != 0x6) break;
2252 msleep(10);
2253 }
2254
2255 nluns = 1;
2256 for (i = 0; i < 3; i++) {
2257 if ((rc = ub_sync_getmaxlun(sc)) < 0)
2258 break;
2259 if (rc != 0) {
2260 nluns = rc;
2261 break;
2262 }
2263 msleep(100);
2264 }
2265
2266 for (i = 0; i < nluns; i++) {
2267 ub_probe_lun(sc, i);
2268 }
2269 return 0;
2270
2271 err_dev_desc:
2272 usb_set_intfdata(intf, NULL);
2273 usb_put_intf(sc->intf);
2274 usb_put_dev(sc->dev);
2275 kfree(sc);
2276 err_core:
2277 return rc;
2278 }
2279
2280 static int ub_probe_lun(struct ub_dev *sc, int lnum)
2281 {
2282 struct ub_lun *lun;
2283 struct request_queue *q;
2284 struct gendisk *disk;
2285 int rc;
2286
2287 rc = -ENOMEM;
2288 if ((lun = kzalloc(sizeof(struct ub_lun), GFP_KERNEL)) == NULL)
2289 goto err_alloc;
2290 lun->num = lnum;
2291
2292 rc = -ENOSR;
2293 if ((lun->id = ub_id_get()) == -1)
2294 goto err_id;
2295
2296 lun->udev = sc;
2297
2298 snprintf(lun->name, 16, DRV_NAME "%c(%d.%d.%d)",
2299 lun->id + 'a', sc->dev->bus->busnum, sc->dev->devnum, lun->num);
2300
2301 lun->removable = 1; /* XXX Query this from the device */
2302 lun->changed = 1; /* ub_revalidate clears only */
2303 ub_revalidate(sc, lun);
2304
2305 rc = -ENOMEM;
2306 if ((disk = alloc_disk(UB_PARTS_PER_LUN)) == NULL)
2307 goto err_diskalloc;
2308
2309 sprintf(disk->disk_name, DRV_NAME "%c", lun->id + 'a');
2310 disk->major = UB_MAJOR;
2311 disk->first_minor = lun->id * UB_PARTS_PER_LUN;
2312 disk->fops = &ub_bd_fops;
2313 disk->private_data = lun;
2314 disk->driverfs_dev = &sc->intf->dev;
2315
2316 rc = -ENOMEM;
2317 if ((q = blk_init_queue(ub_request_fn, sc->lock)) == NULL)
2318 goto err_blkqinit;
2319
2320 disk->queue = q;
2321
2322 blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
2323 blk_queue_max_hw_segments(q, UB_MAX_REQ_SG);
2324 blk_queue_max_phys_segments(q, UB_MAX_REQ_SG);
2325 blk_queue_segment_boundary(q, 0xffffffff); /* Dubious. */
2326 blk_queue_max_sectors(q, UB_MAX_SECTORS);
2327 blk_queue_logical_block_size(q, lun->capacity.bsize);
2328
2329 lun->disk = disk;
2330 q->queuedata = lun;
2331 list_add(&lun->link, &sc->luns);
2332
2333 set_capacity(disk, lun->capacity.nsec);
2334 if (lun->removable)
2335 disk->flags |= GENHD_FL_REMOVABLE;
2336
2337 add_disk(disk);
2338
2339 return 0;
2340
2341 err_blkqinit:
2342 put_disk(disk);
2343 err_diskalloc:
2344 ub_id_put(lun->id);
2345 err_id:
2346 kfree(lun);
2347 err_alloc:
2348 return rc;
2349 }
2350
2351 static void ub_disconnect(struct usb_interface *intf)
2352 {
2353 struct ub_dev *sc = usb_get_intfdata(intf);
2354 struct ub_lun *lun;
2355 unsigned long flags;
2356
2357 /*
2358 * Prevent ub_bd_release from pulling the rug from under us.
2359 * XXX This is starting to look like a kref.
2360 * XXX Why not to take this ref at probe time?
2361 */
2362 spin_lock_irqsave(&ub_lock, flags);
2363 sc->openc++;
2364 spin_unlock_irqrestore(&ub_lock, flags);
2365
2366 /*
2367 * Fence stall clearings, operations triggered by unlinkings and so on.
2368 * We do not attempt to unlink any URBs, because we do not trust the
2369 * unlink paths in HC drivers. Also, we get -84 upon disconnect anyway.
2370 */
2371 atomic_set(&sc->poison, 1);
2372
2373 /*
2374 * Wait for reset to end, if any.
2375 */
2376 wait_event(sc->reset_wait, !sc->reset);
2377
2378 /*
2379 * Blow away queued commands.
2380 *
2381 * Actually, this never works, because before we get here
2382 * the HCD terminates outstanding URB(s). It causes our
2383 * SCSI command queue to advance, commands fail to submit,
2384 * and the whole queue drains. So, we just use this code to
2385 * print warnings.
2386 */
2387 spin_lock_irqsave(sc->lock, flags);
2388 {
2389 struct ub_scsi_cmd *cmd;
2390 int cnt = 0;
2391 while ((cmd = ub_cmdq_peek(sc)) != NULL) {
2392 cmd->error = -ENOTCONN;
2393 cmd->state = UB_CMDST_DONE;
2394 ub_cmdq_pop(sc);
2395 (*cmd->done)(sc, cmd);
2396 cnt++;
2397 }
2398 if (cnt != 0) {
2399 printk(KERN_WARNING "%s: "
2400 "%d was queued after shutdown\n", sc->name, cnt);
2401 }
2402 }
2403 spin_unlock_irqrestore(sc->lock, flags);
2404
2405 /*
2406 * Unregister the upper layer.
2407 */
2408 list_for_each_entry(lun, &sc->luns, link) {
2409 del_gendisk(lun->disk);
2410 /*
2411 * I wish I could do:
2412 * queue_flag_set(QUEUE_FLAG_DEAD, q);
2413 * As it is, we rely on our internal poisoning and let
2414 * the upper levels to spin furiously failing all the I/O.
2415 */
2416 }
2417
2418 /*
2419 * Testing for -EINPROGRESS is always a bug, so we are bending
2420 * the rules a little.
2421 */
2422 spin_lock_irqsave(sc->lock, flags);
2423 if (sc->work_urb.status == -EINPROGRESS) { /* janitors: ignore */
2424 printk(KERN_WARNING "%s: "
2425 "URB is active after disconnect\n", sc->name);
2426 }
2427 spin_unlock_irqrestore(sc->lock, flags);
2428
2429 /*
2430 * There is virtually no chance that other CPU runs a timeout so long
2431 * after ub_urb_complete should have called del_timer, but only if HCD
2432 * didn't forget to deliver a callback on unlink.
2433 */
2434 del_timer_sync(&sc->work_timer);
2435
2436 /*
2437 * At this point there must be no commands coming from anyone
2438 * and no URBs left in transit.
2439 */
2440
2441 ub_put(sc);
2442 }
2443
2444 static struct usb_driver ub_driver = {
2445 .name = "ub",
2446 .probe = ub_probe,
2447 .disconnect = ub_disconnect,
2448 .id_table = ub_usb_ids,
2449 .pre_reset = ub_pre_reset,
2450 .post_reset = ub_post_reset,
2451 };
2452
2453 static int __init ub_init(void)
2454 {
2455 int rc;
2456 int i;
2457
2458 for (i = 0; i < UB_QLOCK_NUM; i++)
2459 spin_lock_init(&ub_qlockv[i]);
2460
2461 if ((rc = register_blkdev(UB_MAJOR, DRV_NAME)) != 0)
2462 goto err_regblkdev;
2463
2464 if ((rc = usb_register(&ub_driver)) != 0)
2465 goto err_register;
2466
2467 usb_usual_set_present(USB_US_TYPE_UB);
2468 return 0;
2469
2470 err_register:
2471 unregister_blkdev(UB_MAJOR, DRV_NAME);
2472 err_regblkdev:
2473 return rc;
2474 }
2475
2476 static void __exit ub_exit(void)
2477 {
2478 usb_deregister(&ub_driver);
2479
2480 unregister_blkdev(UB_MAJOR, DRV_NAME);
2481 usb_usual_clear_present(USB_US_TYPE_UB);
2482 }
2483
2484 module_init(ub_init);
2485 module_exit(ub_exit);
2486
2487 MODULE_LICENSE("GPL");
2488
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