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Merge commit 'v2.6.30.10' into mini2440-stable-v2.6.30
[linux-2.6/mini2440.git] / drivers / block / ub.c
blob689cd27ac890afff8c39dc11bdac5e605e37816c
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 unsigned int cmd_len);
365 static int ub_rw_cmd_retry(struct ub_dev *sc, struct ub_lun *lun,
366 struct ub_request *urq, struct ub_scsi_cmd *cmd);
367 static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
368 static void ub_urb_complete(struct urb *urb);
369 static void ub_scsi_action(unsigned long _dev);
370 static void ub_scsi_dispatch(struct ub_dev *sc);
371 static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
372 static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
373 static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc);
374 static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
375 static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
376 static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
377 static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
378 static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
379 int stalled_pipe);
380 static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd);
381 static void ub_reset_enter(struct ub_dev *sc, int try);
382 static void ub_reset_task(struct work_struct *work);
383 static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun);
384 static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
385 struct ub_capacity *ret);
386 static int ub_sync_reset(struct ub_dev *sc);
387 static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe);
388 static int ub_probe_lun(struct ub_dev *sc, int lnum);
389
390 /*
391 */
392 #ifdef CONFIG_USB_LIBUSUAL
393
394 #define ub_usb_ids usb_storage_usb_ids
395 #else
396
397 static struct usb_device_id ub_usb_ids[] = {
398 { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, US_SC_SCSI, US_PR_BULK) },
399 { }
400 };
401
402 MODULE_DEVICE_TABLE(usb, ub_usb_ids);
403 #endif /* CONFIG_USB_LIBUSUAL */
404
405 /*
406 * Find me a way to identify "next free minor" for add_disk(),
407 * and the array disappears the next day. However, the number of
408 * hosts has something to do with the naming and /proc/partitions.
409 * This has to be thought out in detail before changing.
410 * If UB_MAX_HOST was 1000, we'd use a bitmap. Or a better data structure.
411 */
412 #define UB_MAX_HOSTS 26
413 static char ub_hostv[UB_MAX_HOSTS];
414
415 #define UB_QLOCK_NUM 5
416 static spinlock_t ub_qlockv[UB_QLOCK_NUM];
417 static int ub_qlock_next = 0;
418
419 static DEFINE_SPINLOCK(ub_lock); /* Locks globals and ->openc */
420
421 /*
422 * The id allocator.
423 *
424 * This also stores the host for indexing by minor, which is somewhat dirty.
425 */
426 static int ub_id_get(void)
427 {
428 unsigned long flags;
429 int i;
430
431 spin_lock_irqsave(&ub_lock, flags);
432 for (i = 0; i < UB_MAX_HOSTS; i++) {
433 if (ub_hostv[i] == 0) {
434 ub_hostv[i] = 1;
435 spin_unlock_irqrestore(&ub_lock, flags);
436 return i;
437 }
438 }
439 spin_unlock_irqrestore(&ub_lock, flags);
440 return -1;
441 }
442
443 static void ub_id_put(int id)
444 {
445 unsigned long flags;
446
447 if (id < 0 || id >= UB_MAX_HOSTS) {
448 printk(KERN_ERR DRV_NAME ": bad host ID %d\n", id);
449 return;
450 }
451
452 spin_lock_irqsave(&ub_lock, flags);
453 if (ub_hostv[id] == 0) {
454 spin_unlock_irqrestore(&ub_lock, flags);
455 printk(KERN_ERR DRV_NAME ": freeing free host ID %d\n", id);
456 return;
457 }
458 ub_hostv[id] = 0;
459 spin_unlock_irqrestore(&ub_lock, flags);
460 }
461
462 /*
463 * This is necessitated by the fact that blk_cleanup_queue does not
464 * necesserily destroy the queue. Instead, it may merely decrease q->refcnt.
465 * Since our blk_init_queue() passes a spinlock common with ub_dev,
466 * we have life time issues when ub_cleanup frees ub_dev.
467 */
468 static spinlock_t *ub_next_lock(void)
469 {
470 unsigned long flags;
471 spinlock_t *ret;
472
473 spin_lock_irqsave(&ub_lock, flags);
474 ret = &ub_qlockv[ub_qlock_next];
475 ub_qlock_next = (ub_qlock_next + 1) % UB_QLOCK_NUM;
476 spin_unlock_irqrestore(&ub_lock, flags);
477 return ret;
478 }
479
480 /*
481 * Downcount for deallocation. This rides on two assumptions:
482 * - once something is poisoned, its refcount cannot grow
483 * - opens cannot happen at this time (del_gendisk was done)
484 * If the above is true, we can drop the lock, which we need for
485 * blk_cleanup_queue(): the silly thing may attempt to sleep.
486 * [Actually, it never needs to sleep for us, but it calls might_sleep()]
487 */
488 static void ub_put(struct ub_dev *sc)
489 {
490 unsigned long flags;
491
492 spin_lock_irqsave(&ub_lock, flags);
493 --sc->openc;
494 if (sc->openc == 0 && atomic_read(&sc->poison)) {
495 spin_unlock_irqrestore(&ub_lock, flags);
496 ub_cleanup(sc);
497 } else {
498 spin_unlock_irqrestore(&ub_lock, flags);
499 }
500 }
501
502 /*
503 * Final cleanup and deallocation.
504 */
505 static void ub_cleanup(struct ub_dev *sc)
506 {
507 struct list_head *p;
508 struct ub_lun *lun;
509 struct request_queue *q;
510
511 while (!list_empty(&sc->luns)) {
512 p = sc->luns.next;
513 lun = list_entry(p, struct ub_lun, link);
514 list_del(p);
515
516 /* I don't think queue can be NULL. But... Stolen from sx8.c */
517 if ((q = lun->disk->queue) != NULL)
518 blk_cleanup_queue(q);
519 /*
520 * If we zero disk->private_data BEFORE put_disk, we have
521 * to check for NULL all over the place in open, release,
522 * check_media and revalidate, because the block level
523 * semaphore is well inside the put_disk.
524 * But we cannot zero after the call, because *disk is gone.
525 * The sd.c is blatantly racy in this area.
526 */
527 /* disk->private_data = NULL; */
528 put_disk(lun->disk);
529 lun->disk = NULL;
530
531 ub_id_put(lun->id);
532 kfree(lun);
533 }
534
535 usb_set_intfdata(sc->intf, NULL);
536 usb_put_intf(sc->intf);
537 usb_put_dev(sc->dev);
538 kfree(sc);
539 }
540
541 /*
542 * The "command allocator".
543 */
544 static struct ub_scsi_cmd *ub_get_cmd(struct ub_lun *lun)
545 {
546 struct ub_scsi_cmd *ret;
547
548 if (lun->cmda[0])
549 return NULL;
550 ret = &lun->cmdv[0];
551 lun->cmda[0] = 1;
552 return ret;
553 }
554
555 static void ub_put_cmd(struct ub_lun *lun, struct ub_scsi_cmd *cmd)
556 {
557 if (cmd != &lun->cmdv[0]) {
558 printk(KERN_WARNING "%s: releasing a foreign cmd %p\n",
559 lun->name, cmd);
560 return;
561 }
562 if (!lun->cmda[0]) {
563 printk(KERN_WARNING "%s: releasing a free cmd\n", lun->name);
564 return;
565 }
566 lun->cmda[0] = 0;
567 }
568
569 /*
570 * The command queue.
571 */
572 static void ub_cmdq_add(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
573 {
574 struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
575
576 if (t->qlen++ == 0) {
577 t->head = cmd;
578 t->tail = cmd;
579 } else {
580 t->tail->next = cmd;
581 t->tail = cmd;
582 }
583
584 if (t->qlen > t->qmax)
585 t->qmax = t->qlen;
586 }
587
588 static void ub_cmdq_insert(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
589 {
590 struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
591
592 if (t->qlen++ == 0) {
593 t->head = cmd;
594 t->tail = cmd;
595 } else {
596 cmd->next = t->head;
597 t->head = cmd;
598 }
599
600 if (t->qlen > t->qmax)
601 t->qmax = t->qlen;
602 }
603
604 static struct ub_scsi_cmd *ub_cmdq_pop(struct ub_dev *sc)
605 {
606 struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
607 struct ub_scsi_cmd *cmd;
608
609 if (t->qlen == 0)
610 return NULL;
611 if (--t->qlen == 0)
612 t->tail = NULL;
613 cmd = t->head;
614 t->head = cmd->next;
615 cmd->next = NULL;
616 return cmd;
617 }
618
619 #define ub_cmdq_peek(sc) ((sc)->cmd_queue.head)
620
621 /*
622 * The request function is our main entry point
623 */
624
625 static void ub_request_fn(struct request_queue *q)
626 {
627 struct ub_lun *lun = q->queuedata;
628 struct request *rq;
629
630 while ((rq = elv_next_request(q)) != NULL) {
631 if (ub_request_fn_1(lun, rq) != 0) {
632 blk_stop_queue(q);
633 break;
634 }
635 }
636 }
637
638 static int ub_request_fn_1(struct ub_lun *lun, struct request *rq)
639 {
640 struct ub_dev *sc = lun->udev;
641 struct ub_scsi_cmd *cmd;
642 struct ub_request *urq;
643 int n_elem;
644
645 if (atomic_read(&sc->poison)) {
646 blkdev_dequeue_request(rq);
647 ub_end_rq(rq, DID_NO_CONNECT << 16, blk_rq_bytes(rq));
648 return 0;
649 }
650
651 if (lun->changed && !blk_pc_request(rq)) {
652 blkdev_dequeue_request(rq);
653 ub_end_rq(rq, SAM_STAT_CHECK_CONDITION, blk_rq_bytes(rq));
654 return 0;
655 }
656
657 if (lun->urq.rq != NULL)
658 return -1;
659 if ((cmd = ub_get_cmd(lun)) == NULL)
660 return -1;
661 memset(cmd, 0, sizeof(struct ub_scsi_cmd));
662
663 blkdev_dequeue_request(rq);
664
665 urq = &lun->urq;
666 memset(urq, 0, sizeof(struct ub_request));
667 urq->rq = rq;
668
669 /*
670 * get scatterlist from block layer
671 */
672 sg_init_table(&urq->sgv[0], UB_MAX_REQ_SG);
673 n_elem = blk_rq_map_sg(lun->disk->queue, rq, &urq->sgv[0]);
674 if (n_elem < 0) {
675 /* Impossible, because blk_rq_map_sg should not hit ENOMEM. */
676 printk(KERN_INFO "%s: failed request map (%d)\n",
677 lun->name, n_elem);
678 goto drop;
679 }
680 if (n_elem > UB_MAX_REQ_SG) { /* Paranoia */
681 printk(KERN_WARNING "%s: request with %d segments\n",
682 lun->name, n_elem);
683 goto drop;
684 }
685 urq->nsg = n_elem;
686
687 if (blk_pc_request(rq)) {
688 ub_cmd_build_packet(sc, lun, cmd, urq);
689 } else {
690 ub_cmd_build_block(sc, lun, cmd, urq);
691 }
692 cmd->state = UB_CMDST_INIT;
693 cmd->lun = lun;
694 cmd->done = ub_rw_cmd_done;
695 cmd->back = urq;
696
697 cmd->tag = sc->tagcnt++;
698 if (ub_submit_scsi(sc, cmd) != 0)
699 goto drop;
700
701 return 0;
702
703 drop:
704 ub_put_cmd(lun, cmd);
705 ub_end_rq(rq, DID_ERROR << 16, blk_rq_bytes(rq));
706 return 0;
707 }
708
709 static void ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
710 struct ub_scsi_cmd *cmd, struct ub_request *urq)
711 {
712 struct request *rq = urq->rq;
713 unsigned int block, nblks;
714
715 if (rq_data_dir(rq) == WRITE)
716 cmd->dir = UB_DIR_WRITE;
717 else
718 cmd->dir = UB_DIR_READ;
719
720 cmd->nsg = urq->nsg;
721 memcpy(cmd->sgv, urq->sgv, sizeof(struct scatterlist) * cmd->nsg);
722
723 /*
724 * build the command
725 *
726 * The call to blk_queue_hardsect_size() guarantees that request
727 * is aligned, but it is given in terms of 512 byte units, always.
728 */
729 block = rq->sector >> lun->capacity.bshift;
730 nblks = rq->nr_sectors >> lun->capacity.bshift;
731
732 cmd->cdb[0] = (cmd->dir == UB_DIR_READ)? READ_10: WRITE_10;
733 /* 10-byte uses 4 bytes of LBA: 2147483648KB, 2097152MB, 2048GB */
734 cmd->cdb[2] = block >> 24;
735 cmd->cdb[3] = block >> 16;
736 cmd->cdb[4] = block >> 8;
737 cmd->cdb[5] = block;
738 cmd->cdb[7] = nblks >> 8;
739 cmd->cdb[8] = nblks;
740 cmd->cdb_len = 10;
741
742 cmd->len = rq->nr_sectors * 512;
743 }
744
745 static void ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
746 struct ub_scsi_cmd *cmd, struct ub_request *urq)
747 {
748 struct request *rq = urq->rq;
749
750 if (rq->data_len == 0) {
751 cmd->dir = UB_DIR_NONE;
752 } else {
753 if (rq_data_dir(rq) == WRITE)
754 cmd->dir = UB_DIR_WRITE;
755 else
756 cmd->dir = UB_DIR_READ;
757 }
758
759 cmd->nsg = urq->nsg;
760 memcpy(cmd->sgv, urq->sgv, sizeof(struct scatterlist) * cmd->nsg);
761
762 memcpy(&cmd->cdb, rq->cmd, rq->cmd_len);
763 cmd->cdb_len = rq->cmd_len;
764
765 cmd->len = rq->data_len;
766
767 /*
768 * To reapply this to every URB is not as incorrect as it looks.
769 * In return, we avoid any complicated tracking calculations.
770 */
771 cmd->timeo = rq->timeout;
772 }
773
774 static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
775 {
776 struct ub_lun *lun = cmd->lun;
777 struct ub_request *urq = cmd->back;
778 struct request *rq;
779 unsigned int scsi_status;
780 unsigned int cmd_len;
781
782 rq = urq->rq;
783
784 if (cmd->error == 0) {
785 if (blk_pc_request(rq)) {
786 if (cmd->act_len >= rq->data_len)
787 rq->data_len = 0;
788 else
789 rq->data_len -= cmd->act_len;
790 scsi_status = 0;
791 } else {
792 if (cmd->act_len != cmd->len) {
793 scsi_status = SAM_STAT_CHECK_CONDITION;
794 } else {
795 scsi_status = 0;
796 }
797 }
798 } else {
799 if (blk_pc_request(rq)) {
800 /* UB_SENSE_SIZE is smaller than SCSI_SENSE_BUFFERSIZE */
801 memcpy(rq->sense, sc->top_sense, UB_SENSE_SIZE);
802 rq->sense_len = UB_SENSE_SIZE;
803 if (sc->top_sense[0] != 0)
804 scsi_status = SAM_STAT_CHECK_CONDITION;
805 else
806 scsi_status = DID_ERROR << 16;
807 } else {
808 if (cmd->error == -EIO &&
809 (cmd->key == 0 ||
810 cmd->key == MEDIUM_ERROR ||
811 cmd->key == UNIT_ATTENTION)) {
812 if (ub_rw_cmd_retry(sc, lun, urq, cmd) == 0)
813 return;
814 }
815 scsi_status = SAM_STAT_CHECK_CONDITION;
816 }
817 }
818
819 urq->rq = NULL;
820
821 cmd_len = cmd->len;
822 ub_put_cmd(lun, cmd);
823 ub_end_rq(rq, scsi_status, cmd_len);
824 blk_start_queue(lun->disk->queue);
825 }
826
827 static void ub_end_rq(struct request *rq, unsigned int scsi_status,
828 unsigned int cmd_len)
829 {
830 int error;
831 long rqlen;
832
833 if (scsi_status == 0) {
834 error = 0;
835 } else {
836 error = -EIO;
837 rq->errors = scsi_status;
838 }
839 rqlen = blk_rq_bytes(rq); /* Oddly enough, this is the residue. */
840 if (__blk_end_request(rq, error, cmd_len)) {
841 printk(KERN_WARNING DRV_NAME
842 ": __blk_end_request blew, %s-cmd total %u rqlen %ld\n",
843 blk_pc_request(rq)? "pc": "fs", cmd_len, rqlen);
844 }
845 }
846
847 static int ub_rw_cmd_retry(struct ub_dev *sc, struct ub_lun *lun,
848 struct ub_request *urq, struct ub_scsi_cmd *cmd)
849 {
850
851 if (atomic_read(&sc->poison))
852 return -ENXIO;
853
854 ub_reset_enter(sc, urq->current_try);
855
856 if (urq->current_try >= 3)
857 return -EIO;
858 urq->current_try++;
859
860 /* Remove this if anyone complains of flooding. */
861 printk(KERN_DEBUG "%s: dir %c len/act %d/%d "
862 "[sense %x %02x %02x] retry %d\n",
863 sc->name, UB_DIR_CHAR(cmd->dir), cmd->len, cmd->act_len,
864 cmd->key, cmd->asc, cmd->ascq, urq->current_try);
865
866 memset(cmd, 0, sizeof(struct ub_scsi_cmd));
867 ub_cmd_build_block(sc, lun, cmd, urq);
868
869 cmd->state = UB_CMDST_INIT;
870 cmd->lun = lun;
871 cmd->done = ub_rw_cmd_done;
872 cmd->back = urq;
873
874 cmd->tag = sc->tagcnt++;
875
876 #if 0 /* Wasteful */
877 return ub_submit_scsi(sc, cmd);
878 #else
879 ub_cmdq_add(sc, cmd);
880 return 0;
881 #endif
882 }
883
884 /*
885 * Submit a regular SCSI operation (not an auto-sense).
886 *
887 * The Iron Law of Good Submit Routine is:
888 * Zero return - callback is done, Nonzero return - callback is not done.
889 * No exceptions.
890 *
891 * Host is assumed locked.
892 */
893 static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
894 {
895
896 if (cmd->state != UB_CMDST_INIT ||
897 (cmd->dir != UB_DIR_NONE && cmd->len == 0)) {
898 return -EINVAL;
899 }
900
901 ub_cmdq_add(sc, cmd);
902 /*
903 * We can call ub_scsi_dispatch(sc) right away here, but it's a little
904 * safer to jump to a tasklet, in case upper layers do something silly.
905 */
906 tasklet_schedule(&sc->tasklet);
907 return 0;
908 }
909
910 /*
911 * Submit the first URB for the queued command.
912 * This function does not deal with queueing in any way.
913 */
914 static int ub_scsi_cmd_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
915 {
916 struct bulk_cb_wrap *bcb;
917 int rc;
918
919 bcb = &sc->work_bcb;
920
921 /*
922 * ``If the allocation length is eighteen or greater, and a device
923 * server returns less than eithteen bytes of data, the application
924 * client should assume that the bytes not transferred would have been
925 * zeroes had the device server returned those bytes.''
926 *
927 * We zero sense for all commands so that when a packet request
928 * fails it does not return a stale sense.
929 */
930 memset(&sc->top_sense, 0, UB_SENSE_SIZE);
931
932 /* set up the command wrapper */
933 bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
934 bcb->Tag = cmd->tag; /* Endianness is not important */
935 bcb->DataTransferLength = cpu_to_le32(cmd->len);
936 bcb->Flags = (cmd->dir == UB_DIR_READ) ? 0x80 : 0;
937 bcb->Lun = (cmd->lun != NULL) ? cmd->lun->num : 0;
938 bcb->Length = cmd->cdb_len;
939
940 /* copy the command payload */
941 memcpy(bcb->CDB, cmd->cdb, UB_MAX_CDB_SIZE);
942
943 UB_INIT_COMPLETION(sc->work_done);
944
945 sc->last_pipe = sc->send_bulk_pipe;
946 usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->send_bulk_pipe,
947 bcb, US_BULK_CB_WRAP_LEN, ub_urb_complete, sc);
948
949 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
950 /* XXX Clear stalls */
951 ub_complete(&sc->work_done);
952 return rc;
953 }
954
955 sc->work_timer.expires = jiffies + UB_URB_TIMEOUT;
956 add_timer(&sc->work_timer);
957
958 cmd->state = UB_CMDST_CMD;
959 return 0;
960 }
961
962 /*
963 * Timeout handler.
964 */
965 static void ub_urb_timeout(unsigned long arg)
966 {
967 struct ub_dev *sc = (struct ub_dev *) arg;
968 unsigned long flags;
969
970 spin_lock_irqsave(sc->lock, flags);
971 if (!ub_is_completed(&sc->work_done))
972 usb_unlink_urb(&sc->work_urb);
973 spin_unlock_irqrestore(sc->lock, flags);
974 }
975
976 /*
977 * Completion routine for the work URB.
978 *
979 * This can be called directly from usb_submit_urb (while we have
980 * the sc->lock taken) and from an interrupt (while we do NOT have
981 * the sc->lock taken). Therefore, bounce this off to a tasklet.
982 */
983 static void ub_urb_complete(struct urb *urb)
984 {
985 struct ub_dev *sc = urb->context;
986
987 ub_complete(&sc->work_done);
988 tasklet_schedule(&sc->tasklet);
989 }
990
991 static void ub_scsi_action(unsigned long _dev)
992 {
993 struct ub_dev *sc = (struct ub_dev *) _dev;
994 unsigned long flags;
995
996 spin_lock_irqsave(sc->lock, flags);
997 ub_scsi_dispatch(sc);
998 spin_unlock_irqrestore(sc->lock, flags);
999 }
1000
1001 static void ub_scsi_dispatch(struct ub_dev *sc)
1002 {
1003 struct ub_scsi_cmd *cmd;
1004 int rc;
1005
1006 while (!sc->reset && (cmd = ub_cmdq_peek(sc)) != NULL) {
1007 if (cmd->state == UB_CMDST_DONE) {
1008 ub_cmdq_pop(sc);
1009 (*cmd->done)(sc, cmd);
1010 } else if (cmd->state == UB_CMDST_INIT) {
1011 if ((rc = ub_scsi_cmd_start(sc, cmd)) == 0)
1012 break;
1013 cmd->error = rc;
1014 cmd->state = UB_CMDST_DONE;
1015 } else {
1016 if (!ub_is_completed(&sc->work_done))
1017 break;
1018 del_timer(&sc->work_timer);
1019 ub_scsi_urb_compl(sc, cmd);
1020 }
1021 }
1022 }
1023
1024 static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1025 {
1026 struct urb *urb = &sc->work_urb;
1027 struct bulk_cs_wrap *bcs;
1028 int endp;
1029 int len;
1030 int rc;
1031
1032 if (atomic_read(&sc->poison)) {
1033 ub_state_done(sc, cmd, -ENODEV);
1034 return;
1035 }
1036
1037 endp = usb_pipeendpoint(sc->last_pipe);
1038 if (usb_pipein(sc->last_pipe))
1039 endp |= USB_DIR_IN;
1040
1041 if (cmd->state == UB_CMDST_CLEAR) {
1042 if (urb->status == -EPIPE) {
1043 /*
1044 * STALL while clearning STALL.
1045 * The control pipe clears itself - nothing to do.
1046 */
1047 printk(KERN_NOTICE "%s: stall on control pipe\n",
1048 sc->name);
1049 goto Bad_End;
1050 }
1051
1052 /*
1053 * We ignore the result for the halt clear.
1054 */
1055
1056 usb_reset_endpoint(sc->dev, endp);
1057
1058 ub_state_sense(sc, cmd);
1059
1060 } else if (cmd->state == UB_CMDST_CLR2STS) {
1061 if (urb->status == -EPIPE) {
1062 printk(KERN_NOTICE "%s: stall on control pipe\n",
1063 sc->name);
1064 goto Bad_End;
1065 }
1066
1067 /*
1068 * We ignore the result for the halt clear.
1069 */
1070
1071 usb_reset_endpoint(sc->dev, endp);
1072
1073 ub_state_stat(sc, cmd);
1074
1075 } else if (cmd->state == UB_CMDST_CLRRS) {
1076 if (urb->status == -EPIPE) {
1077 printk(KERN_NOTICE "%s: stall on control pipe\n",
1078 sc->name);
1079 goto Bad_End;
1080 }
1081
1082 /*
1083 * We ignore the result for the halt clear.
1084 */
1085
1086 usb_reset_endpoint(sc->dev, endp);
1087
1088 ub_state_stat_counted(sc, cmd);
1089
1090 } else if (cmd->state == UB_CMDST_CMD) {
1091 switch (urb->status) {
1092 case 0:
1093 break;
1094 case -EOVERFLOW:
1095 goto Bad_End;
1096 case -EPIPE:
1097 rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1098 if (rc != 0) {
1099 printk(KERN_NOTICE "%s: "
1100 "unable to submit clear (%d)\n",
1101 sc->name, rc);
1102 /*
1103 * This is typically ENOMEM or some other such shit.
1104 * Retrying is pointless. Just do Bad End on it...
1105 */
1106 ub_state_done(sc, cmd, rc);
1107 return;
1108 }
1109 cmd->state = UB_CMDST_CLEAR;
1110 return;
1111 case -ESHUTDOWN: /* unplug */
1112 case -EILSEQ: /* unplug timeout on uhci */
1113 ub_state_done(sc, cmd, -ENODEV);
1114 return;
1115 default:
1116 goto Bad_End;
1117 }
1118 if (urb->actual_length != US_BULK_CB_WRAP_LEN) {
1119 goto Bad_End;
1120 }
1121
1122 if (cmd->dir == UB_DIR_NONE || cmd->nsg < 1) {
1123 ub_state_stat(sc, cmd);
1124 return;
1125 }
1126
1127 // udelay(125); // usb-storage has this
1128 ub_data_start(sc, cmd);
1129
1130 } else if (cmd->state == UB_CMDST_DATA) {
1131 if (urb->status == -EPIPE) {
1132 rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1133 if (rc != 0) {
1134 printk(KERN_NOTICE "%s: "
1135 "unable to submit clear (%d)\n",
1136 sc->name, rc);
1137 ub_state_done(sc, cmd, rc);
1138 return;
1139 }
1140 cmd->state = UB_CMDST_CLR2STS;
1141 return;
1142 }
1143 if (urb->status == -EOVERFLOW) {
1144 /*
1145 * A babble? Failure, but we must transfer CSW now.
1146 */
1147 cmd->error = -EOVERFLOW; /* A cheap trick... */
1148 ub_state_stat(sc, cmd);
1149 return;
1150 }
1151
1152 if (cmd->dir == UB_DIR_WRITE) {
1153 /*
1154 * Do not continue writes in case of a failure.
1155 * Doing so would cause sectors to be mixed up,
1156 * which is worse than sectors lost.
1157 *
1158 * We must try to read the CSW, or many devices
1159 * get confused.
1160 */
1161 len = urb->actual_length;
1162 if (urb->status != 0 ||
1163 len != cmd->sgv[cmd->current_sg].length) {
1164 cmd->act_len += len;
1165
1166 cmd->error = -EIO;
1167 ub_state_stat(sc, cmd);
1168 return;
1169 }
1170
1171 } else {
1172 /*
1173 * If an error occurs on read, we record it, and
1174 * continue to fetch data in order to avoid bubble.
1175 *
1176 * As a small shortcut, we stop if we detect that
1177 * a CSW mixed into data.
1178 */
1179 if (urb->status != 0)
1180 cmd->error = -EIO;
1181
1182 len = urb->actual_length;
1183 if (urb->status != 0 ||
1184 len != cmd->sgv[cmd->current_sg].length) {
1185 if ((len & 0x1FF) == US_BULK_CS_WRAP_LEN)
1186 goto Bad_End;
1187 }
1188 }
1189
1190 cmd->act_len += urb->actual_length;
1191
1192 if (++cmd->current_sg < cmd->nsg) {
1193 ub_data_start(sc, cmd);
1194 return;
1195 }
1196 ub_state_stat(sc, cmd);
1197
1198 } else if (cmd->state == UB_CMDST_STAT) {
1199 if (urb->status == -EPIPE) {
1200 rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1201 if (rc != 0) {
1202 printk(KERN_NOTICE "%s: "
1203 "unable to submit clear (%d)\n",
1204 sc->name, rc);
1205 ub_state_done(sc, cmd, rc);
1206 return;
1207 }
1208
1209 /*
1210 * Having a stall when getting CSW is an error, so
1211 * make sure uppper levels are not oblivious to it.
1212 */
1213 cmd->error = -EIO; /* A cheap trick... */
1214
1215 cmd->state = UB_CMDST_CLRRS;
1216 return;
1217 }
1218
1219 /* Catch everything, including -EOVERFLOW and other nasties. */
1220 if (urb->status != 0)
1221 goto Bad_End;
1222
1223 if (urb->actual_length == 0) {
1224 ub_state_stat_counted(sc, cmd);
1225 return;
1226 }
1227
1228 /*
1229 * Check the returned Bulk protocol status.
1230 * The status block has to be validated first.
1231 */
1232
1233 bcs = &sc->work_bcs;
1234
1235 if (sc->signature == cpu_to_le32(0)) {
1236 /*
1237 * This is the first reply, so do not perform the check.
1238 * Instead, remember the signature the device uses
1239 * for future checks. But do not allow a nul.
1240 */
1241 sc->signature = bcs->Signature;
1242 if (sc->signature == cpu_to_le32(0)) {
1243 ub_state_stat_counted(sc, cmd);
1244 return;
1245 }
1246 } else {
1247 if (bcs->Signature != sc->signature) {
1248 ub_state_stat_counted(sc, cmd);
1249 return;
1250 }
1251 }
1252
1253 if (bcs->Tag != cmd->tag) {
1254 /*
1255 * This usually happens when we disagree with the
1256 * device's microcode about something. For instance,
1257 * a few of them throw this after timeouts. They buffer
1258 * commands and reply at commands we timed out before.
1259 * Without flushing these replies we loop forever.
1260 */
1261 ub_state_stat_counted(sc, cmd);
1262 return;
1263 }
1264
1265 if (!sc->bad_resid) {
1266 len = le32_to_cpu(bcs->Residue);
1267 if (len != cmd->len - cmd->act_len) {
1268 /*
1269 * Only start ignoring if this cmd ended well.
1270 */
1271 if (cmd->len == cmd->act_len) {
1272 printk(KERN_NOTICE "%s: "
1273 "bad residual %d of %d, ignoring\n",
1274 sc->name, len, cmd->len);
1275 sc->bad_resid = 1;
1276 }
1277 }
1278 }
1279
1280 switch (bcs->Status) {
1281 case US_BULK_STAT_OK:
1282 break;
1283 case US_BULK_STAT_FAIL:
1284 ub_state_sense(sc, cmd);
1285 return;
1286 case US_BULK_STAT_PHASE:
1287 goto Bad_End;
1288 default:
1289 printk(KERN_INFO "%s: unknown CSW status 0x%x\n",
1290 sc->name, bcs->Status);
1291 ub_state_done(sc, cmd, -EINVAL);
1292 return;
1293 }
1294
1295 /* Not zeroing error to preserve a babble indicator */
1296 if (cmd->error != 0) {
1297 ub_state_sense(sc, cmd);
1298 return;
1299 }
1300 cmd->state = UB_CMDST_DONE;
1301 ub_cmdq_pop(sc);
1302 (*cmd->done)(sc, cmd);
1303
1304 } else if (cmd->state == UB_CMDST_SENSE) {
1305 ub_state_done(sc, cmd, -EIO);
1306
1307 } else {
1308 printk(KERN_WARNING "%s: wrong command state %d\n",
1309 sc->name, cmd->state);
1310 ub_state_done(sc, cmd, -EINVAL);
1311 return;
1312 }
1313 return;
1314
1315 Bad_End: /* Little Excel is dead */
1316 ub_state_done(sc, cmd, -EIO);
1317 }
1318
1319 /*
1320 * Factorization helper for the command state machine:
1321 * Initiate a data segment transfer.
1322 */
1323 static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1324 {
1325 struct scatterlist *sg = &cmd->sgv[cmd->current_sg];
1326 int pipe;
1327 int rc;
1328
1329 UB_INIT_COMPLETION(sc->work_done);
1330
1331 if (cmd->dir == UB_DIR_READ)
1332 pipe = sc->recv_bulk_pipe;
1333 else
1334 pipe = sc->send_bulk_pipe;
1335 sc->last_pipe = pipe;
1336 usb_fill_bulk_urb(&sc->work_urb, sc->dev, pipe, sg_virt(sg),
1337 sg->length, ub_urb_complete, sc);
1338
1339 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1340 /* XXX Clear stalls */
1341 ub_complete(&sc->work_done);
1342 ub_state_done(sc, cmd, rc);
1343 return;
1344 }
1345
1346 if (cmd->timeo)
1347 sc->work_timer.expires = jiffies + cmd->timeo;
1348 else
1349 sc->work_timer.expires = jiffies + UB_DATA_TIMEOUT;
1350 add_timer(&sc->work_timer);
1351
1352 cmd->state = UB_CMDST_DATA;
1353 }
1354
1355 /*
1356 * Factorization helper for the command state machine:
1357 * Finish the command.
1358 */
1359 static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc)
1360 {
1361
1362 cmd->error = rc;
1363 cmd->state = UB_CMDST_DONE;
1364 ub_cmdq_pop(sc);
1365 (*cmd->done)(sc, cmd);
1366 }
1367
1368 /*
1369 * Factorization helper for the command state machine:
1370 * Submit a CSW read.
1371 */
1372 static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1373 {
1374 int rc;
1375
1376 UB_INIT_COMPLETION(sc->work_done);
1377
1378 sc->last_pipe = sc->recv_bulk_pipe;
1379 usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->recv_bulk_pipe,
1380 &sc->work_bcs, US_BULK_CS_WRAP_LEN, ub_urb_complete, sc);
1381
1382 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1383 /* XXX Clear stalls */
1384 ub_complete(&sc->work_done);
1385 ub_state_done(sc, cmd, rc);
1386 return -1;
1387 }
1388
1389 if (cmd->timeo)
1390 sc->work_timer.expires = jiffies + cmd->timeo;
1391 else
1392 sc->work_timer.expires = jiffies + UB_STAT_TIMEOUT;
1393 add_timer(&sc->work_timer);
1394 return 0;
1395 }
1396
1397 /*
1398 * Factorization helper for the command state machine:
1399 * Submit a CSW read and go to STAT state.
1400 */
1401 static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1402 {
1403
1404 if (__ub_state_stat(sc, cmd) != 0)
1405 return;
1406
1407 cmd->stat_count = 0;
1408 cmd->state = UB_CMDST_STAT;
1409 }
1410
1411 /*
1412 * Factorization helper for the command state machine:
1413 * Submit a CSW read and go to STAT state with counter (along [C] path).
1414 */
1415 static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1416 {
1417
1418 if (++cmd->stat_count >= 4) {
1419 ub_state_sense(sc, cmd);
1420 return;
1421 }
1422
1423 if (__ub_state_stat(sc, cmd) != 0)
1424 return;
1425
1426 cmd->state = UB_CMDST_STAT;
1427 }
1428
1429 /*
1430 * Factorization helper for the command state machine:
1431 * Submit a REQUEST SENSE and go to SENSE state.
1432 */
1433 static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1434 {
1435 struct ub_scsi_cmd *scmd;
1436 struct scatterlist *sg;
1437 int rc;
1438
1439 if (cmd->cdb[0] == REQUEST_SENSE) {
1440 rc = -EPIPE;
1441 goto error;
1442 }
1443
1444 scmd = &sc->top_rqs_cmd;
1445 memset(scmd, 0, sizeof(struct ub_scsi_cmd));
1446 scmd->cdb[0] = REQUEST_SENSE;
1447 scmd->cdb[4] = UB_SENSE_SIZE;
1448 scmd->cdb_len = 6;
1449 scmd->dir = UB_DIR_READ;
1450 scmd->state = UB_CMDST_INIT;
1451 scmd->nsg = 1;
1452 sg = &scmd->sgv[0];
1453 sg_init_table(sg, UB_MAX_REQ_SG);
1454 sg_set_page(sg, virt_to_page(sc->top_sense), UB_SENSE_SIZE,
1455 (unsigned long)sc->top_sense & (PAGE_SIZE-1));
1456 scmd->len = UB_SENSE_SIZE;
1457 scmd->lun = cmd->lun;
1458 scmd->done = ub_top_sense_done;
1459 scmd->back = cmd;
1460
1461 scmd->tag = sc->tagcnt++;
1462
1463 cmd->state = UB_CMDST_SENSE;
1464
1465 ub_cmdq_insert(sc, scmd);
1466 return;
1467
1468 error:
1469 ub_state_done(sc, cmd, rc);
1470 }
1471
1472 /*
1473 * A helper for the command's state machine:
1474 * Submit a stall clear.
1475 */
1476 static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
1477 int stalled_pipe)
1478 {
1479 int endp;
1480 struct usb_ctrlrequest *cr;
1481 int rc;
1482
1483 endp = usb_pipeendpoint(stalled_pipe);
1484 if (usb_pipein (stalled_pipe))
1485 endp |= USB_DIR_IN;
1486
1487 cr = &sc->work_cr;
1488 cr->bRequestType = USB_RECIP_ENDPOINT;
1489 cr->bRequest = USB_REQ_CLEAR_FEATURE;
1490 cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
1491 cr->wIndex = cpu_to_le16(endp);
1492 cr->wLength = cpu_to_le16(0);
1493
1494 UB_INIT_COMPLETION(sc->work_done);
1495
1496 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
1497 (unsigned char*) cr, NULL, 0, ub_urb_complete, sc);
1498
1499 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1500 ub_complete(&sc->work_done);
1501 return rc;
1502 }
1503
1504 sc->work_timer.expires = jiffies + UB_CTRL_TIMEOUT;
1505 add_timer(&sc->work_timer);
1506 return 0;
1507 }
1508
1509 /*
1510 */
1511 static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd)
1512 {
1513 unsigned char *sense = sc->top_sense;
1514 struct ub_scsi_cmd *cmd;
1515
1516 /*
1517 * Find the command which triggered the unit attention or a check,
1518 * save the sense into it, and advance its state machine.
1519 */
1520 if ((cmd = ub_cmdq_peek(sc)) == NULL) {
1521 printk(KERN_WARNING "%s: sense done while idle\n", sc->name);
1522 return;
1523 }
1524 if (cmd != scmd->back) {
1525 printk(KERN_WARNING "%s: "
1526 "sense done for wrong command 0x%x\n",
1527 sc->name, cmd->tag);
1528 return;
1529 }
1530 if (cmd->state != UB_CMDST_SENSE) {
1531 printk(KERN_WARNING "%s: sense done with bad cmd state %d\n",
1532 sc->name, cmd->state);
1533 return;
1534 }
1535
1536 /*
1537 * Ignoring scmd->act_len, because the buffer was pre-zeroed.
1538 */
1539 cmd->key = sense[2] & 0x0F;
1540 cmd->asc = sense[12];
1541 cmd->ascq = sense[13];
1542
1543 ub_scsi_urb_compl(sc, cmd);
1544 }
1545
1546 /*
1547 * Reset management
1548 */
1549
1550 static void ub_reset_enter(struct ub_dev *sc, int try)
1551 {
1552
1553 if (sc->reset) {
1554 /* This happens often on multi-LUN devices. */
1555 return;
1556 }
1557 sc->reset = try + 1;
1558
1559 #if 0 /* Not needed because the disconnect waits for us. */
1560 unsigned long flags;
1561 spin_lock_irqsave(&ub_lock, flags);
1562 sc->openc++;
1563 spin_unlock_irqrestore(&ub_lock, flags);
1564 #endif
1565
1566 #if 0 /* We let them stop themselves. */
1567 struct ub_lun *lun;
1568 list_for_each_entry(lun, &sc->luns, link) {
1569 blk_stop_queue(lun->disk->queue);
1570 }
1571 #endif
1572
1573 schedule_work(&sc->reset_work);
1574 }
1575
1576 static void ub_reset_task(struct work_struct *work)
1577 {
1578 struct ub_dev *sc = container_of(work, struct ub_dev, reset_work);
1579 unsigned long flags;
1580 struct ub_lun *lun;
1581 int rc;
1582
1583 if (!sc->reset) {
1584 printk(KERN_WARNING "%s: Running reset unrequested\n",
1585 sc->name);
1586 return;
1587 }
1588
1589 if (atomic_read(&sc->poison)) {
1590 ;
1591 } else if ((sc->reset & 1) == 0) {
1592 ub_sync_reset(sc);
1593 msleep(700); /* usb-storage sleeps 6s (!) */
1594 ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
1595 ub_probe_clear_stall(sc, sc->send_bulk_pipe);
1596 } else if (sc->dev->actconfig->desc.bNumInterfaces != 1) {
1597 ;
1598 } else {
1599 rc = usb_lock_device_for_reset(sc->dev, sc->intf);
1600 if (rc < 0) {
1601 printk(KERN_NOTICE
1602 "%s: usb_lock_device_for_reset failed (%d)\n",
1603 sc->name, rc);
1604 } else {
1605 rc = usb_reset_device(sc->dev);
1606 if (rc < 0) {
1607 printk(KERN_NOTICE "%s: "
1608 "usb_lock_device_for_reset failed (%d)\n",
1609 sc->name, rc);
1610 }
1611 usb_unlock_device(sc->dev);
1612 }
1613 }
1614
1615 /*
1616 * In theory, no commands can be running while reset is active,
1617 * so nobody can ask for another reset, and so we do not need any
1618 * queues of resets or anything. We do need a spinlock though,
1619 * to interact with block layer.
1620 */
1621 spin_lock_irqsave(sc->lock, flags);
1622 sc->reset = 0;
1623 tasklet_schedule(&sc->tasklet);
1624 list_for_each_entry(lun, &sc->luns, link) {
1625 blk_start_queue(lun->disk->queue);
1626 }
1627 wake_up(&sc->reset_wait);
1628 spin_unlock_irqrestore(sc->lock, flags);
1629 }
1630
1631 /*
1632 * XXX Reset brackets are too much hassle to implement, so just stub them
1633 * in order to prevent forced unbinding (which deadlocks solid when our
1634 * ->disconnect method waits for the reset to complete and this kills keventd).
1635 *
1636 * XXX Tell Alan to move usb_unlock_device inside of usb_reset_device,
1637 * or else the post_reset is invoked, and restats I/O on a locked device.
1638 */
1639 static int ub_pre_reset(struct usb_interface *iface) {
1640 return 0;
1641 }
1642
1643 static int ub_post_reset(struct usb_interface *iface) {
1644 return 0;
1645 }
1646
1647 /*
1648 * This is called from a process context.
1649 */
1650 static void ub_revalidate(struct ub_dev *sc, struct ub_lun *lun)
1651 {
1652
1653 lun->readonly = 0; /* XXX Query this from the device */
1654
1655 lun->capacity.nsec = 0;
1656 lun->capacity.bsize = 512;
1657 lun->capacity.bshift = 0;
1658
1659 if (ub_sync_tur(sc, lun) != 0)
1660 return; /* Not ready */
1661 lun->changed = 0;
1662
1663 if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
1664 /*
1665 * The retry here means something is wrong, either with the
1666 * device, with the transport, or with our code.
1667 * We keep this because sd.c has retries for capacity.
1668 */
1669 if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
1670 lun->capacity.nsec = 0;
1671 lun->capacity.bsize = 512;
1672 lun->capacity.bshift = 0;
1673 }
1674 }
1675 }
1676
1677 /*
1678 * The open funcion.
1679 * This is mostly needed to keep refcounting, but also to support
1680 * media checks on removable media drives.
1681 */
1682 static int ub_bd_open(struct block_device *bdev, fmode_t mode)
1683 {
1684 struct ub_lun *lun = bdev->bd_disk->private_data;
1685 struct ub_dev *sc = lun->udev;
1686 unsigned long flags;
1687 int rc;
1688
1689 spin_lock_irqsave(&ub_lock, flags);
1690 if (atomic_read(&sc->poison)) {
1691 spin_unlock_irqrestore(&ub_lock, flags);
1692 return -ENXIO;
1693 }
1694 sc->openc++;
1695 spin_unlock_irqrestore(&ub_lock, flags);
1696
1697 if (lun->removable || lun->readonly)
1698 check_disk_change(bdev);
1699
1700 /*
1701 * The sd.c considers ->media_present and ->changed not equivalent,
1702 * under some pretty murky conditions (a failure of READ CAPACITY).
1703 * We may need it one day.
1704 */
1705 if (lun->removable && lun->changed && !(mode & FMODE_NDELAY)) {
1706 rc = -ENOMEDIUM;
1707 goto err_open;
1708 }
1709
1710 if (lun->readonly && (mode & FMODE_WRITE)) {
1711 rc = -EROFS;
1712 goto err_open;
1713 }
1714
1715 return 0;
1716
1717 err_open:
1718 ub_put(sc);
1719 return rc;
1720 }
1721
1722 /*
1723 */
1724 static int ub_bd_release(struct gendisk *disk, fmode_t mode)
1725 {
1726 struct ub_lun *lun = disk->private_data;
1727 struct ub_dev *sc = lun->udev;
1728
1729 ub_put(sc);
1730 return 0;
1731 }
1732
1733 /*
1734 * The ioctl interface.
1735 */
1736 static int ub_bd_ioctl(struct block_device *bdev, fmode_t mode,
1737 unsigned int cmd, unsigned long arg)
1738 {
1739 struct gendisk *disk = bdev->bd_disk;
1740 void __user *usermem = (void __user *) arg;
1741
1742 return scsi_cmd_ioctl(disk->queue, disk, mode, cmd, usermem);
1743 }
1744
1745 /*
1746 * This is called by check_disk_change if we reported a media change.
1747 * The main onjective here is to discover the features of the media such as
1748 * the capacity, read-only status, etc. USB storage generally does not
1749 * need to be spun up, but if we needed it, this would be the place.
1750 *
1751 * This call can sleep.
1752 *
1753 * The return code is not used.
1754 */
1755 static int ub_bd_revalidate(struct gendisk *disk)
1756 {
1757 struct ub_lun *lun = disk->private_data;
1758
1759 ub_revalidate(lun->udev, lun);
1760
1761 /* XXX Support sector size switching like in sr.c */
1762 blk_queue_hardsect_size(disk->queue, lun->capacity.bsize);
1763 set_capacity(disk, lun->capacity.nsec);
1764 // set_disk_ro(sdkp->disk, lun->readonly);
1765
1766 return 0;
1767 }
1768
1769 /*
1770 * The check is called by the block layer to verify if the media
1771 * is still available. It is supposed to be harmless, lightweight and
1772 * non-intrusive in case the media was not changed.
1773 *
1774 * This call can sleep.
1775 *
1776 * The return code is bool!
1777 */
1778 static int ub_bd_media_changed(struct gendisk *disk)
1779 {
1780 struct ub_lun *lun = disk->private_data;
1781
1782 if (!lun->removable)
1783 return 0;
1784
1785 /*
1786 * We clean checks always after every command, so this is not
1787 * as dangerous as it looks. If the TEST_UNIT_READY fails here,
1788 * the device is actually not ready with operator or software
1789 * intervention required. One dangerous item might be a drive which
1790 * spins itself down, and come the time to write dirty pages, this
1791 * will fail, then block layer discards the data. Since we never
1792 * spin drives up, such devices simply cannot be used with ub anyway.
1793 */
1794 if (ub_sync_tur(lun->udev, lun) != 0) {
1795 lun->changed = 1;
1796 return 1;
1797 }
1798
1799 return lun->changed;
1800 }
1801
1802 static struct block_device_operations ub_bd_fops = {
1803 .owner = THIS_MODULE,
1804 .open = ub_bd_open,
1805 .release = ub_bd_release,
1806 .locked_ioctl = ub_bd_ioctl,
1807 .media_changed = ub_bd_media_changed,
1808 .revalidate_disk = ub_bd_revalidate,
1809 };
1810
1811 /*
1812 * Common ->done routine for commands executed synchronously.
1813 */
1814 static void ub_probe_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1815 {
1816 struct completion *cop = cmd->back;
1817 complete(cop);
1818 }
1819
1820 /*
1821 * Test if the device has a check condition on it, synchronously.
1822 */
1823 static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun)
1824 {
1825 struct ub_scsi_cmd *cmd;
1826 enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) };
1827 unsigned long flags;
1828 struct completion compl;
1829 int rc;
1830
1831 init_completion(&compl);
1832
1833 rc = -ENOMEM;
1834 if ((cmd = kzalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
1835 goto err_alloc;
1836
1837 cmd->cdb[0] = TEST_UNIT_READY;
1838 cmd->cdb_len = 6;
1839 cmd->dir = UB_DIR_NONE;
1840 cmd->state = UB_CMDST_INIT;
1841 cmd->lun = lun; /* This may be NULL, but that's ok */
1842 cmd->done = ub_probe_done;
1843 cmd->back = &compl;
1844
1845 spin_lock_irqsave(sc->lock, flags);
1846 cmd->tag = sc->tagcnt++;
1847
1848 rc = ub_submit_scsi(sc, cmd);
1849 spin_unlock_irqrestore(sc->lock, flags);
1850
1851 if (rc != 0)
1852 goto err_submit;
1853
1854 wait_for_completion(&compl);
1855
1856 rc = cmd->error;
1857
1858 if (rc == -EIO && cmd->key != 0) /* Retries for benh's key */
1859 rc = cmd->key;
1860
1861 err_submit:
1862 kfree(cmd);
1863 err_alloc:
1864 return rc;
1865 }
1866
1867 /*
1868 * Read the SCSI capacity synchronously (for probing).
1869 */
1870 static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
1871 struct ub_capacity *ret)
1872 {
1873 struct ub_scsi_cmd *cmd;
1874 struct scatterlist *sg;
1875 char *p;
1876 enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) + 8 };
1877 unsigned long flags;
1878 unsigned int bsize, shift;
1879 unsigned long nsec;
1880 struct completion compl;
1881 int rc;
1882
1883 init_completion(&compl);
1884
1885 rc = -ENOMEM;
1886 if ((cmd = kzalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
1887 goto err_alloc;
1888 p = (char *)cmd + sizeof(struct ub_scsi_cmd);
1889
1890 cmd->cdb[0] = 0x25;
1891 cmd->cdb_len = 10;
1892 cmd->dir = UB_DIR_READ;
1893 cmd->state = UB_CMDST_INIT;
1894 cmd->nsg = 1;
1895 sg = &cmd->sgv[0];
1896 sg_init_table(sg, UB_MAX_REQ_SG);
1897 sg_set_page(sg, virt_to_page(p), 8, (unsigned long)p & (PAGE_SIZE-1));
1898 cmd->len = 8;
1899 cmd->lun = lun;
1900 cmd->done = ub_probe_done;
1901 cmd->back = &compl;
1902
1903 spin_lock_irqsave(sc->lock, flags);
1904 cmd->tag = sc->tagcnt++;
1905
1906 rc = ub_submit_scsi(sc, cmd);
1907 spin_unlock_irqrestore(sc->lock, flags);
1908
1909 if (rc != 0)
1910 goto err_submit;
1911
1912 wait_for_completion(&compl);
1913
1914 if (cmd->error != 0) {
1915 rc = -EIO;
1916 goto err_read;
1917 }
1918 if (cmd->act_len != 8) {
1919 rc = -EIO;
1920 goto err_read;
1921 }
1922
1923 /* sd.c special-cases sector size of 0 to mean 512. Needed? Safe? */
1924 nsec = be32_to_cpu(*(__be32 *)p) + 1;
1925 bsize = be32_to_cpu(*(__be32 *)(p + 4));
1926 switch (bsize) {
1927 case 512: shift = 0; break;
1928 case 1024: shift = 1; break;
1929 case 2048: shift = 2; break;
1930 case 4096: shift = 3; break;
1931 default:
1932 rc = -EDOM;
1933 goto err_inv_bsize;
1934 }
1935
1936 ret->bsize = bsize;
1937 ret->bshift = shift;
1938 ret->nsec = nsec << shift;
1939 rc = 0;
1940
1941 err_inv_bsize:
1942 err_read:
1943 err_submit:
1944 kfree(cmd);
1945 err_alloc:
1946 return rc;
1947 }
1948
1949 /*
1950 */
1951 static void ub_probe_urb_complete(struct urb *urb)
1952 {
1953 struct completion *cop = urb->context;
1954 complete(cop);
1955 }
1956
1957 static void ub_probe_timeout(unsigned long arg)
1958 {
1959 struct completion *cop = (struct completion *) arg;
1960 complete(cop);
1961 }
1962
1963 /*
1964 * Reset with a Bulk reset.
1965 */
1966 static int ub_sync_reset(struct ub_dev *sc)
1967 {
1968 int ifnum = sc->intf->cur_altsetting->desc.bInterfaceNumber;
1969 struct usb_ctrlrequest *cr;
1970 struct completion compl;
1971 struct timer_list timer;
1972 int rc;
1973
1974 init_completion(&compl);
1975
1976 cr = &sc->work_cr;
1977 cr->bRequestType = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
1978 cr->bRequest = US_BULK_RESET_REQUEST;
1979 cr->wValue = cpu_to_le16(0);
1980 cr->wIndex = cpu_to_le16(ifnum);
1981 cr->wLength = cpu_to_le16(0);
1982
1983 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
1984 (unsigned char*) cr, NULL, 0, ub_probe_urb_complete, &compl);
1985
1986 if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
1987 printk(KERN_WARNING
1988 "%s: Unable to submit a bulk reset (%d)\n", sc->name, rc);
1989 return rc;
1990 }
1991
1992 init_timer(&timer);
1993 timer.function = ub_probe_timeout;
1994 timer.data = (unsigned long) &compl;
1995 timer.expires = jiffies + UB_CTRL_TIMEOUT;
1996 add_timer(&timer);
1997
1998 wait_for_completion(&compl);
1999
2000 del_timer_sync(&timer);
2001 usb_kill_urb(&sc->work_urb);
2002
2003 return sc->work_urb.status;
2004 }
2005
2006 /*
2007 * Get number of LUNs by the way of Bulk GetMaxLUN command.
2008 */
2009 static int ub_sync_getmaxlun(struct ub_dev *sc)
2010 {
2011 int ifnum = sc->intf->cur_altsetting->desc.bInterfaceNumber;
2012 unsigned char *p;
2013 enum { ALLOC_SIZE = 1 };
2014 struct usb_ctrlrequest *cr;
2015 struct completion compl;
2016 struct timer_list timer;
2017 int nluns;
2018 int rc;
2019
2020 init_completion(&compl);
2021
2022 rc = -ENOMEM;
2023 if ((p = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
2024 goto err_alloc;
2025 *p = 55;
2026
2027 cr = &sc->work_cr;
2028 cr->bRequestType = USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE;
2029 cr->bRequest = US_BULK_GET_MAX_LUN;
2030 cr->wValue = cpu_to_le16(0);
2031 cr->wIndex = cpu_to_le16(ifnum);
2032 cr->wLength = cpu_to_le16(1);
2033
2034 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->recv_ctrl_pipe,
2035 (unsigned char*) cr, p, 1, ub_probe_urb_complete, &compl);
2036
2037 if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0)
2038 goto err_submit;
2039
2040 init_timer(&timer);
2041 timer.function = ub_probe_timeout;
2042 timer.data = (unsigned long) &compl;
2043 timer.expires = jiffies + UB_CTRL_TIMEOUT;
2044 add_timer(&timer);
2045
2046 wait_for_completion(&compl);
2047
2048 del_timer_sync(&timer);
2049 usb_kill_urb(&sc->work_urb);
2050
2051 if ((rc = sc->work_urb.status) < 0)
2052 goto err_io;
2053
2054 if (sc->work_urb.actual_length != 1) {
2055 nluns = 0;
2056 } else {
2057 if ((nluns = *p) == 55) {
2058 nluns = 0;
2059 } else {
2060 /* GetMaxLUN returns the maximum LUN number */
2061 nluns += 1;
2062 if (nluns > UB_MAX_LUNS)
2063 nluns = UB_MAX_LUNS;
2064 }
2065 }
2066
2067 kfree(p);
2068 return nluns;
2069
2070 err_io:
2071 err_submit:
2072 kfree(p);
2073 err_alloc:
2074 return rc;
2075 }
2076
2077 /*
2078 * Clear initial stalls.
2079 */
2080 static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe)
2081 {
2082 int endp;
2083 struct usb_ctrlrequest *cr;
2084 struct completion compl;
2085 struct timer_list timer;
2086 int rc;
2087
2088 init_completion(&compl);
2089
2090 endp = usb_pipeendpoint(stalled_pipe);
2091 if (usb_pipein (stalled_pipe))
2092 endp |= USB_DIR_IN;
2093
2094 cr = &sc->work_cr;
2095 cr->bRequestType = USB_RECIP_ENDPOINT;
2096 cr->bRequest = USB_REQ_CLEAR_FEATURE;
2097 cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
2098 cr->wIndex = cpu_to_le16(endp);
2099 cr->wLength = cpu_to_le16(0);
2100
2101 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
2102 (unsigned char*) cr, NULL, 0, ub_probe_urb_complete, &compl);
2103
2104 if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
2105 printk(KERN_WARNING
2106 "%s: Unable to submit a probe clear (%d)\n", sc->name, rc);
2107 return rc;
2108 }
2109
2110 init_timer(&timer);
2111 timer.function = ub_probe_timeout;
2112 timer.data = (unsigned long) &compl;
2113 timer.expires = jiffies + UB_CTRL_TIMEOUT;
2114 add_timer(&timer);
2115
2116 wait_for_completion(&compl);
2117
2118 del_timer_sync(&timer);
2119 usb_kill_urb(&sc->work_urb);
2120
2121 usb_reset_endpoint(sc->dev, endp);
2122
2123 return 0;
2124 }
2125
2126 /*
2127 * Get the pipe settings.
2128 */
2129 static int ub_get_pipes(struct ub_dev *sc, struct usb_device *dev,
2130 struct usb_interface *intf)
2131 {
2132 struct usb_host_interface *altsetting = intf->cur_altsetting;
2133 struct usb_endpoint_descriptor *ep_in = NULL;
2134 struct usb_endpoint_descriptor *ep_out = NULL;
2135 struct usb_endpoint_descriptor *ep;
2136 int i;
2137
2138 /*
2139 * Find the endpoints we need.
2140 * We are expecting a minimum of 2 endpoints - in and out (bulk).
2141 * We will ignore any others.
2142 */
2143 for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
2144 ep = &altsetting->endpoint[i].desc;
2145
2146 /* Is it a BULK endpoint? */
2147 if (usb_endpoint_xfer_bulk(ep)) {
2148 /* BULK in or out? */
2149 if (usb_endpoint_dir_in(ep)) {
2150 if (ep_in == NULL)
2151 ep_in = ep;
2152 } else {
2153 if (ep_out == NULL)
2154 ep_out = ep;
2155 }
2156 }
2157 }
2158
2159 if (ep_in == NULL || ep_out == NULL) {
2160 printk(KERN_NOTICE "%s: failed endpoint check\n", sc->name);
2161 return -ENODEV;
2162 }
2163
2164 /* Calculate and store the pipe values */
2165 sc->send_ctrl_pipe = usb_sndctrlpipe(dev, 0);
2166 sc->recv_ctrl_pipe = usb_rcvctrlpipe(dev, 0);
2167 sc->send_bulk_pipe = usb_sndbulkpipe(dev,
2168 usb_endpoint_num(ep_out));
2169 sc->recv_bulk_pipe = usb_rcvbulkpipe(dev,
2170 usb_endpoint_num(ep_in));
2171
2172 return 0;
2173 }
2174
2175 /*
2176 * Probing is done in the process context, which allows us to cheat
2177 * and not to build a state machine for the discovery.
2178 */
2179 static int ub_probe(struct usb_interface *intf,
2180 const struct usb_device_id *dev_id)
2181 {
2182 struct ub_dev *sc;
2183 int nluns;
2184 int rc;
2185 int i;
2186
2187 if (usb_usual_check_type(dev_id, USB_US_TYPE_UB))
2188 return -ENXIO;
2189
2190 rc = -ENOMEM;
2191 if ((sc = kzalloc(sizeof(struct ub_dev), GFP_KERNEL)) == NULL)
2192 goto err_core;
2193 sc->lock = ub_next_lock();
2194 INIT_LIST_HEAD(&sc->luns);
2195 usb_init_urb(&sc->work_urb);
2196 tasklet_init(&sc->tasklet, ub_scsi_action, (unsigned long)sc);
2197 atomic_set(&sc->poison, 0);
2198 INIT_WORK(&sc->reset_work, ub_reset_task);
2199 init_waitqueue_head(&sc->reset_wait);
2200
2201 init_timer(&sc->work_timer);
2202 sc->work_timer.data = (unsigned long) sc;
2203 sc->work_timer.function = ub_urb_timeout;
2204
2205 ub_init_completion(&sc->work_done);
2206 sc->work_done.done = 1; /* A little yuk, but oh well... */
2207
2208 sc->dev = interface_to_usbdev(intf);
2209 sc->intf = intf;
2210 // sc->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
2211 usb_set_intfdata(intf, sc);
2212 usb_get_dev(sc->dev);
2213 /*
2214 * Since we give the interface struct to the block level through
2215 * disk->driverfs_dev, we have to pin it. Otherwise, block_uevent
2216 * oopses on close after a disconnect (kernels 2.6.16 and up).
2217 */
2218 usb_get_intf(sc->intf);
2219
2220 snprintf(sc->name, 12, DRV_NAME "(%d.%d)",
2221 sc->dev->bus->busnum, sc->dev->devnum);
2222
2223 /* XXX Verify that we can handle the device (from descriptors) */
2224
2225 if (ub_get_pipes(sc, sc->dev, intf) != 0)
2226 goto err_dev_desc;
2227
2228 /*
2229 * At this point, all USB initialization is done, do upper layer.
2230 * We really hate halfway initialized structures, so from the
2231 * invariants perspective, this ub_dev is fully constructed at
2232 * this point.
2233 */
2234
2235 /*
2236 * This is needed to clear toggles. It is a problem only if we do
2237 * `rmmod ub && modprobe ub` without disconnects, but we like that.
2238 */
2239 #if 0 /* iPod Mini fails if we do this (big white iPod works) */
2240 ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
2241 ub_probe_clear_stall(sc, sc->send_bulk_pipe);
2242 #endif
2243
2244 /*
2245 * The way this is used by the startup code is a little specific.
2246 * A SCSI check causes a USB stall. Our common case code sees it
2247 * and clears the check, after which the device is ready for use.
2248 * But if a check was not present, any command other than
2249 * TEST_UNIT_READY ends with a lockup (including REQUEST_SENSE).
2250 *
2251 * If we neglect to clear the SCSI check, the first real command fails
2252 * (which is the capacity readout). We clear that and retry, but why
2253 * causing spurious retries for no reason.
2254 *
2255 * Revalidation may start with its own TEST_UNIT_READY, but that one
2256 * has to succeed, so we clear checks with an additional one here.
2257 * In any case it's not our business how revaliadation is implemented.
2258 */
2259 for (i = 0; i < 3; i++) { /* Retries for the schwag key from KS'04 */
2260 if ((rc = ub_sync_tur(sc, NULL)) <= 0) break;
2261 if (rc != 0x6) break;
2262 msleep(10);
2263 }
2264
2265 nluns = 1;
2266 for (i = 0; i < 3; i++) {
2267 if ((rc = ub_sync_getmaxlun(sc)) < 0)
2268 break;
2269 if (rc != 0) {
2270 nluns = rc;
2271 break;
2272 }
2273 msleep(100);
2274 }
2275
2276 for (i = 0; i < nluns; i++) {
2277 ub_probe_lun(sc, i);
2278 }
2279 return 0;
2280
2281 err_dev_desc:
2282 usb_set_intfdata(intf, NULL);
2283 usb_put_intf(sc->intf);
2284 usb_put_dev(sc->dev);
2285 kfree(sc);
2286 err_core:
2287 return rc;
2288 }
2289
2290 static int ub_probe_lun(struct ub_dev *sc, int lnum)
2291 {
2292 struct ub_lun *lun;
2293 struct request_queue *q;
2294 struct gendisk *disk;
2295 int rc;
2296
2297 rc = -ENOMEM;
2298 if ((lun = kzalloc(sizeof(struct ub_lun), GFP_KERNEL)) == NULL)
2299 goto err_alloc;
2300 lun->num = lnum;
2301
2302 rc = -ENOSR;
2303 if ((lun->id = ub_id_get()) == -1)
2304 goto err_id;
2305
2306 lun->udev = sc;
2307
2308 snprintf(lun->name, 16, DRV_NAME "%c(%d.%d.%d)",
2309 lun->id + 'a', sc->dev->bus->busnum, sc->dev->devnum, lun->num);
2310
2311 lun->removable = 1; /* XXX Query this from the device */
2312 lun->changed = 1; /* ub_revalidate clears only */
2313 ub_revalidate(sc, lun);
2314
2315 rc = -ENOMEM;
2316 if ((disk = alloc_disk(UB_PARTS_PER_LUN)) == NULL)
2317 goto err_diskalloc;
2318
2319 sprintf(disk->disk_name, DRV_NAME "%c", lun->id + 'a');
2320 disk->major = UB_MAJOR;
2321 disk->first_minor = lun->id * UB_PARTS_PER_LUN;
2322 disk->fops = &ub_bd_fops;
2323 disk->private_data = lun;
2324 disk->driverfs_dev = &sc->intf->dev;
2325
2326 rc = -ENOMEM;
2327 if ((q = blk_init_queue(ub_request_fn, sc->lock)) == NULL)
2328 goto err_blkqinit;
2329
2330 disk->queue = q;
2331
2332 blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
2333 blk_queue_max_hw_segments(q, UB_MAX_REQ_SG);
2334 blk_queue_max_phys_segments(q, UB_MAX_REQ_SG);
2335 blk_queue_segment_boundary(q, 0xffffffff); /* Dubious. */
2336 blk_queue_max_sectors(q, UB_MAX_SECTORS);
2337 blk_queue_hardsect_size(q, lun->capacity.bsize);
2338
2339 lun->disk = disk;
2340 q->queuedata = lun;
2341 list_add(&lun->link, &sc->luns);
2342
2343 set_capacity(disk, lun->capacity.nsec);
2344 if (lun->removable)
2345 disk->flags |= GENHD_FL_REMOVABLE;
2346
2347 add_disk(disk);
2348
2349 return 0;
2350
2351 err_blkqinit:
2352 put_disk(disk);
2353 err_diskalloc:
2354 ub_id_put(lun->id);
2355 err_id:
2356 kfree(lun);
2357 err_alloc:
2358 return rc;
2359 }
2360
2361 static void ub_disconnect(struct usb_interface *intf)
2362 {
2363 struct ub_dev *sc = usb_get_intfdata(intf);
2364 struct ub_lun *lun;
2365 unsigned long flags;
2366
2367 /*
2368 * Prevent ub_bd_release from pulling the rug from under us.
2369 * XXX This is starting to look like a kref.
2370 * XXX Why not to take this ref at probe time?
2371 */
2372 spin_lock_irqsave(&ub_lock, flags);
2373 sc->openc++;
2374 spin_unlock_irqrestore(&ub_lock, flags);
2375
2376 /*
2377 * Fence stall clearings, operations triggered by unlinkings and so on.
2378 * We do not attempt to unlink any URBs, because we do not trust the
2379 * unlink paths in HC drivers. Also, we get -84 upon disconnect anyway.
2380 */
2381 atomic_set(&sc->poison, 1);
2382
2383 /*
2384 * Wait for reset to end, if any.
2385 */
2386 wait_event(sc->reset_wait, !sc->reset);
2387
2388 /*
2389 * Blow away queued commands.
2390 *
2391 * Actually, this never works, because before we get here
2392 * the HCD terminates outstanding URB(s). It causes our
2393 * SCSI command queue to advance, commands fail to submit,
2394 * and the whole queue drains. So, we just use this code to
2395 * print warnings.
2396 */
2397 spin_lock_irqsave(sc->lock, flags);
2398 {
2399 struct ub_scsi_cmd *cmd;
2400 int cnt = 0;
2401 while ((cmd = ub_cmdq_peek(sc)) != NULL) {
2402 cmd->error = -ENOTCONN;
2403 cmd->state = UB_CMDST_DONE;
2404 ub_cmdq_pop(sc);
2405 (*cmd->done)(sc, cmd);
2406 cnt++;
2407 }
2408 if (cnt != 0) {
2409 printk(KERN_WARNING "%s: "
2410 "%d was queued after shutdown\n", sc->name, cnt);
2411 }
2412 }
2413 spin_unlock_irqrestore(sc->lock, flags);
2414
2415 /*
2416 * Unregister the upper layer.
2417 */
2418 list_for_each_entry(lun, &sc->luns, link) {
2419 del_gendisk(lun->disk);
2420 /*
2421 * I wish I could do:
2422 * queue_flag_set(QUEUE_FLAG_DEAD, q);
2423 * As it is, we rely on our internal poisoning and let
2424 * the upper levels to spin furiously failing all the I/O.
2425 */
2426 }
2427
2428 /*
2429 * Testing for -EINPROGRESS is always a bug, so we are bending
2430 * the rules a little.
2431 */
2432 spin_lock_irqsave(sc->lock, flags);
2433 if (sc->work_urb.status == -EINPROGRESS) { /* janitors: ignore */
2434 printk(KERN_WARNING "%s: "
2435 "URB is active after disconnect\n", sc->name);
2436 }
2437 spin_unlock_irqrestore(sc->lock, flags);
2438
2439 /*
2440 * There is virtually no chance that other CPU runs a timeout so long
2441 * after ub_urb_complete should have called del_timer, but only if HCD
2442 * didn't forget to deliver a callback on unlink.
2443 */
2444 del_timer_sync(&sc->work_timer);
2445
2446 /*
2447 * At this point there must be no commands coming from anyone
2448 * and no URBs left in transit.
2449 */
2450
2451 ub_put(sc);
2452 }
2453
2454 static struct usb_driver ub_driver = {
2455 .name = "ub",
2456 .probe = ub_probe,
2457 .disconnect = ub_disconnect,
2458 .id_table = ub_usb_ids,
2459 .pre_reset = ub_pre_reset,
2460 .post_reset = ub_post_reset,
2461 };
2462
2463 static int __init ub_init(void)
2464 {
2465 int rc;
2466 int i;
2467
2468 for (i = 0; i < UB_QLOCK_NUM; i++)
2469 spin_lock_init(&ub_qlockv[i]);
2470
2471 if ((rc = register_blkdev(UB_MAJOR, DRV_NAME)) != 0)
2472 goto err_regblkdev;
2473
2474 if ((rc = usb_register(&ub_driver)) != 0)
2475 goto err_register;
2476
2477 usb_usual_set_present(USB_US_TYPE_UB);
2478 return 0;
2479
2480 err_register:
2481 unregister_blkdev(UB_MAJOR, DRV_NAME);
2482 err_regblkdev:
2483 return rc;
2484 }
2485
2486 static void __exit ub_exit(void)
2487 {
2488 usb_deregister(&ub_driver);
2489
2490 unregister_blkdev(UB_MAJOR, DRV_NAME);
2491 usb_usual_clear_present(USB_US_TYPE_UB);
2492 }
2493
2494 module_init(ub_init);
2495 module_exit(ub_exit);
2496
2497 MODULE_LICENSE("GPL");
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