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[PATCH] USB: clean out an unnecessary NULL check from ub
[deliverable/linux.git] / drivers / block / ub.c
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 * -- set readonly flag for CDs, set removable flag for CF readers
12 * -- do inquiry and verify we got a disk and not a tape (for LUN mismatch)
13 * -- special case some senses, e.g. 3a/0 -> no media present, reduce retries
14 * -- verify the 13 conditions and do bulk resets
15 * -- kill last_pipe and simply do two-state clearing on both pipes
16 * -- highmem
17 * -- move top_sense and work_bcs into separate allocations (if they survive)
18 * for cache purists and esoteric architectures.
19 * -- Allocate structure for LUN 0 before the first ub_sync_tur, avoid NULL. ?
20 * -- prune comments, they are too volumnous
21 * -- Exterminate P3 printks
22 * -- Resove XXX's
23 * -- Redo "benh's retries", perhaps have spin-up code to handle them. V:D=?
24 * -- CLEAR, CLR2STS, CLRRS seem to be ripe for refactoring.
25 */
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/usb.h>
29 #include <linux/usb_usual.h>
30 #include <linux/blkdev.h>
31 #include <linux/devfs_fs_kernel.h>
32 #include <linux/timer.h>
33 #include <scsi/scsi.h>
34
35 #define DRV_NAME "ub"
36 #define DEVFS_NAME DRV_NAME
37
38 #define UB_MAJOR 180
39
40 /*
41 * The command state machine is the key model for understanding of this driver.
42 *
43 * The general rule is that all transitions are done towards the bottom
44 * of the diagram, thus preventing any loops.
45 *
46 * An exception to that is how the STAT state is handled. A counter allows it
47 * to be re-entered along the path marked with [C].
48 *
49 * +--------+
50 * ! INIT !
51 * +--------+
52 * !
53 * ub_scsi_cmd_start fails ->--------------------------------------\
54 * ! !
55 * V !
56 * +--------+ !
57 * ! CMD ! !
58 * +--------+ !
59 * ! +--------+ !
60 * was -EPIPE -->-------------------------------->! CLEAR ! !
61 * ! +--------+ !
62 * ! ! !
63 * was error -->------------------------------------- ! --------->\
64 * ! ! !
65 * /--<-- cmd->dir == NONE ? ! !
66 * ! ! ! !
67 * ! V ! !
68 * ! +--------+ ! !
69 * ! ! DATA ! ! !
70 * ! +--------+ ! !
71 * ! ! +---------+ ! !
72 * ! was -EPIPE -->--------------->! CLR2STS ! ! !
73 * ! ! +---------+ ! !
74 * ! ! ! ! !
75 * ! ! was error -->---- ! --------->\
76 * ! was error -->--------------------- ! ------------- ! --------->\
77 * ! ! ! ! !
78 * ! V ! ! !
79 * \--->+--------+ ! ! !
80 * ! STAT !<--------------------------/ ! !
81 * /--->+--------+ ! !
82 * ! ! ! !
83 * [C] was -EPIPE -->-----------\ ! !
84 * ! ! ! ! !
85 * +<---- len == 0 ! ! !
86 * ! ! ! ! !
87 * ! was error -->--------------------------------------!---------->\
88 * ! ! ! ! !
89 * +<---- bad CSW ! ! !
90 * +<---- bad tag ! ! !
91 * ! ! V ! !
92 * ! ! +--------+ ! !
93 * ! ! ! CLRRS ! ! !
94 * ! ! +--------+ ! !
95 * ! ! ! ! !
96 * \------- ! --------------------[C]--------\ ! !
97 * ! ! ! !
98 * cmd->error---\ +--------+ ! !
99 * ! +--------------->! SENSE !<----------/ !
100 * STAT_FAIL----/ +--------+ !
101 * ! ! V
102 * ! V +--------+
103 * \--------------------------------\--------------------->! DONE !
104 * +--------+
105 */
106
107 /*
108 * This many LUNs per USB device.
109 * Every one of them takes a host, see UB_MAX_HOSTS.
110 */
111 #define UB_MAX_LUNS 9
112
113 /*
114 */
115
116 #define UB_PARTS_PER_LUN 8
117
118 #define UB_MAX_CDB_SIZE 16 /* Corresponds to Bulk */
119
120 #define UB_SENSE_SIZE 18
121
122 /*
123 */
124
125 /* command block wrapper */
126 struct bulk_cb_wrap {
127 __le32 Signature; /* contains 'USBC' */
128 u32 Tag; /* unique per command id */
129 __le32 DataTransferLength; /* size of data */
130 u8 Flags; /* direction in bit 0 */
131 u8 Lun; /* LUN */
132 u8 Length; /* of of the CDB */
133 u8 CDB[UB_MAX_CDB_SIZE]; /* max command */
134 };
135
136 #define US_BULK_CB_WRAP_LEN 31
137 #define US_BULK_CB_SIGN 0x43425355 /*spells out USBC */
138 #define US_BULK_FLAG_IN 1
139 #define US_BULK_FLAG_OUT 0
140
141 /* command status wrapper */
142 struct bulk_cs_wrap {
143 __le32 Signature; /* should = 'USBS' */
144 u32 Tag; /* same as original command */
145 __le32 Residue; /* amount not transferred */
146 u8 Status; /* see below */
147 };
148
149 #define US_BULK_CS_WRAP_LEN 13
150 #define US_BULK_CS_SIGN 0x53425355 /* spells out 'USBS' */
151 #define US_BULK_STAT_OK 0
152 #define US_BULK_STAT_FAIL 1
153 #define US_BULK_STAT_PHASE 2
154
155 /* bulk-only class specific requests */
156 #define US_BULK_RESET_REQUEST 0xff
157 #define US_BULK_GET_MAX_LUN 0xfe
158
159 /*
160 */
161 struct ub_dev;
162
163 #define UB_MAX_REQ_SG 9 /* cdrecord requires 32KB and maybe a header */
164 #define UB_MAX_SECTORS 64
165
166 /*
167 * A second is more than enough for a 32K transfer (UB_MAX_SECTORS)
168 * even if a webcam hogs the bus, but some devices need time to spin up.
169 */
170 #define UB_URB_TIMEOUT (HZ*2)
171 #define UB_DATA_TIMEOUT (HZ*5) /* ZIP does spin-ups in the data phase */
172 #define UB_STAT_TIMEOUT (HZ*5) /* Same spinups and eject for a dataless cmd. */
173 #define UB_CTRL_TIMEOUT (HZ/2) /* 500ms ought to be enough to clear a stall */
174
175 /*
176 * An instance of a SCSI command in transit.
177 */
178 #define UB_DIR_NONE 0
179 #define UB_DIR_READ 1
180 #define UB_DIR_ILLEGAL2 2
181 #define UB_DIR_WRITE 3
182
183 /* P3 */
184 #define UB_DIR_CHAR(c) (((c)==UB_DIR_WRITE)? 'w': \
185 (((c)==UB_DIR_READ)? 'r': 'n'))
186
187 enum ub_scsi_cmd_state {
188 UB_CMDST_INIT, /* Initial state */
189 UB_CMDST_CMD, /* Command submitted */
190 UB_CMDST_DATA, /* Data phase */
191 UB_CMDST_CLR2STS, /* Clearing before requesting status */
192 UB_CMDST_STAT, /* Status phase */
193 UB_CMDST_CLEAR, /* Clearing a stall (halt, actually) */
194 UB_CMDST_CLRRS, /* Clearing before retrying status */
195 UB_CMDST_SENSE, /* Sending Request Sense */
196 UB_CMDST_DONE /* Final state */
197 };
198
199 struct ub_scsi_cmd {
200 unsigned char cdb[UB_MAX_CDB_SIZE];
201 unsigned char cdb_len;
202
203 unsigned char dir; /* 0 - none, 1 - read, 3 - write. */
204 enum ub_scsi_cmd_state state;
205 unsigned int tag;
206 struct ub_scsi_cmd *next;
207
208 int error; /* Return code - valid upon done */
209 unsigned int act_len; /* Return size */
210 unsigned char key, asc, ascq; /* May be valid if error==-EIO */
211
212 int stat_count; /* Retries getting status. */
213
214 unsigned int len; /* Requested length */
215 unsigned int current_sg;
216 unsigned int nsg; /* sgv[nsg] */
217 struct scatterlist sgv[UB_MAX_REQ_SG];
218
219 struct ub_lun *lun;
220 void (*done)(struct ub_dev *, struct ub_scsi_cmd *);
221 void *back;
222 };
223
224 struct ub_request {
225 struct request *rq;
226 unsigned int current_try;
227 unsigned int nsg; /* sgv[nsg] */
228 struct scatterlist sgv[UB_MAX_REQ_SG];
229 };
230
231 /*
232 */
233 struct ub_capacity {
234 unsigned long nsec; /* Linux size - 512 byte sectors */
235 unsigned int bsize; /* Linux hardsect_size */
236 unsigned int bshift; /* Shift between 512 and hard sects */
237 };
238
239 /*
240 * This is a direct take-off from linux/include/completion.h
241 * The difference is that I do not wait on this thing, just poll.
242 * When I want to wait (ub_probe), I just use the stock completion.
243 *
244 * Note that INIT_COMPLETION takes no lock. It is correct. But why
245 * in the bloody hell that thing takes struct instead of pointer to struct
246 * is quite beyond me. I just copied it from the stock completion.
247 */
248 struct ub_completion {
249 unsigned int done;
250 spinlock_t lock;
251 };
252
253 static inline void ub_init_completion(struct ub_completion *x)
254 {
255 x->done = 0;
256 spin_lock_init(&x->lock);
257 }
258
259 #define UB_INIT_COMPLETION(x) ((x).done = 0)
260
261 static void ub_complete(struct ub_completion *x)
262 {
263 unsigned long flags;
264
265 spin_lock_irqsave(&x->lock, flags);
266 x->done++;
267 spin_unlock_irqrestore(&x->lock, flags);
268 }
269
270 static int ub_is_completed(struct ub_completion *x)
271 {
272 unsigned long flags;
273 int ret;
274
275 spin_lock_irqsave(&x->lock, flags);
276 ret = x->done;
277 spin_unlock_irqrestore(&x->lock, flags);
278 return ret;
279 }
280
281 /*
282 */
283 struct ub_scsi_cmd_queue {
284 int qlen, qmax;
285 struct ub_scsi_cmd *head, *tail;
286 };
287
288 /*
289 * The block device instance (one per LUN).
290 */
291 struct ub_lun {
292 struct ub_dev *udev;
293 struct list_head link;
294 struct gendisk *disk;
295 int id; /* Host index */
296 int num; /* LUN number */
297 char name[16];
298
299 int changed; /* Media was changed */
300 int removable;
301 int readonly;
302
303 struct ub_request urq;
304
305 /* Use Ingo's mempool if or when we have more than one command. */
306 /*
307 * Currently we never need more than one command for the whole device.
308 * However, giving every LUN a command is a cheap and automatic way
309 * to enforce fairness between them.
310 */
311 int cmda[1];
312 struct ub_scsi_cmd cmdv[1];
313
314 struct ub_capacity capacity;
315 };
316
317 /*
318 * The USB device instance.
319 */
320 struct ub_dev {
321 spinlock_t *lock;
322 atomic_t poison; /* The USB device is disconnected */
323 int openc; /* protected by ub_lock! */
324 /* kref is too implicit for our taste */
325 int reset; /* Reset is running */
326 unsigned int tagcnt;
327 char name[12];
328 struct usb_device *dev;
329 struct usb_interface *intf;
330
331 struct list_head luns;
332
333 unsigned int send_bulk_pipe; /* cached pipe values */
334 unsigned int recv_bulk_pipe;
335 unsigned int send_ctrl_pipe;
336 unsigned int recv_ctrl_pipe;
337
338 struct tasklet_struct tasklet;
339
340 struct ub_scsi_cmd_queue cmd_queue;
341 struct ub_scsi_cmd top_rqs_cmd; /* REQUEST SENSE */
342 unsigned char top_sense[UB_SENSE_SIZE];
343
344 struct ub_completion work_done;
345 struct urb work_urb;
346 struct timer_list work_timer;
347 int last_pipe; /* What might need clearing */
348 __le32 signature; /* Learned signature */
349 struct bulk_cb_wrap work_bcb;
350 struct bulk_cs_wrap work_bcs;
351 struct usb_ctrlrequest work_cr;
352
353 struct work_struct reset_work;
354 wait_queue_head_t reset_wait;
355
356 int sg_stat[6];
357 };
358
359 /*
360 */
361 static void ub_cleanup(struct ub_dev *sc);
362 static int ub_request_fn_1(struct ub_lun *lun, struct request *rq);
363 static void ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
364 struct ub_scsi_cmd *cmd, struct ub_request *urq);
365 static void ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
366 struct ub_scsi_cmd *cmd, struct ub_request *urq);
367 static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
368 static void ub_end_rq(struct request *rq, int uptodate);
369 static int ub_rw_cmd_retry(struct ub_dev *sc, struct ub_lun *lun,
370 struct ub_request *urq, struct ub_scsi_cmd *cmd);
371 static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
372 static void ub_urb_complete(struct urb *urb, struct pt_regs *pt);
373 static void ub_scsi_action(unsigned long _dev);
374 static void ub_scsi_dispatch(struct ub_dev *sc);
375 static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
376 static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
377 static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc);
378 static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
379 static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
380 static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
381 static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
382 static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
383 int stalled_pipe);
384 static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd);
385 static void ub_reset_enter(struct ub_dev *sc, int try);
386 static void ub_reset_task(void *arg);
387 static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun);
388 static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
389 struct ub_capacity *ret);
390 static int ub_sync_reset(struct ub_dev *sc);
391 static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe);
392 static int ub_probe_lun(struct ub_dev *sc, int lnum);
393
394 /*
395 */
396 #ifdef CONFIG_USB_LIBUSUAL
397
398 #define ub_usb_ids storage_usb_ids
399 #else
400
401 static struct usb_device_id ub_usb_ids[] = {
402 { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, US_SC_SCSI, US_PR_BULK) },
403 { }
404 };
405
406 MODULE_DEVICE_TABLE(usb, ub_usb_ids);
407 #endif /* CONFIG_USB_LIBUSUAL */
408
409 /*
410 * Find me a way to identify "next free minor" for add_disk(),
411 * and the array disappears the next day. However, the number of
412 * hosts has something to do with the naming and /proc/partitions.
413 * This has to be thought out in detail before changing.
414 * If UB_MAX_HOST was 1000, we'd use a bitmap. Or a better data structure.
415 */
416 #define UB_MAX_HOSTS 26
417 static char ub_hostv[UB_MAX_HOSTS];
418
419 #define UB_QLOCK_NUM 5
420 static spinlock_t ub_qlockv[UB_QLOCK_NUM];
421 static int ub_qlock_next = 0;
422
423 static DEFINE_SPINLOCK(ub_lock); /* Locks globals and ->openc */
424
425 /*
426 * The id allocator.
427 *
428 * This also stores the host for indexing by minor, which is somewhat dirty.
429 */
430 static int ub_id_get(void)
431 {
432 unsigned long flags;
433 int i;
434
435 spin_lock_irqsave(&ub_lock, flags);
436 for (i = 0; i < UB_MAX_HOSTS; i++) {
437 if (ub_hostv[i] == 0) {
438 ub_hostv[i] = 1;
439 spin_unlock_irqrestore(&ub_lock, flags);
440 return i;
441 }
442 }
443 spin_unlock_irqrestore(&ub_lock, flags);
444 return -1;
445 }
446
447 static void ub_id_put(int id)
448 {
449 unsigned long flags;
450
451 if (id < 0 || id >= UB_MAX_HOSTS) {
452 printk(KERN_ERR DRV_NAME ": bad host ID %d\n", id);
453 return;
454 }
455
456 spin_lock_irqsave(&ub_lock, flags);
457 if (ub_hostv[id] == 0) {
458 spin_unlock_irqrestore(&ub_lock, flags);
459 printk(KERN_ERR DRV_NAME ": freeing free host ID %d\n", id);
460 return;
461 }
462 ub_hostv[id] = 0;
463 spin_unlock_irqrestore(&ub_lock, flags);
464 }
465
466 /*
467 * This is necessitated by the fact that blk_cleanup_queue does not
468 * necesserily destroy the queue. Instead, it may merely decrease q->refcnt.
469 * Since our blk_init_queue() passes a spinlock common with ub_dev,
470 * we have life time issues when ub_cleanup frees ub_dev.
471 */
472 static spinlock_t *ub_next_lock(void)
473 {
474 unsigned long flags;
475 spinlock_t *ret;
476
477 spin_lock_irqsave(&ub_lock, flags);
478 ret = &ub_qlockv[ub_qlock_next];
479 ub_qlock_next = (ub_qlock_next + 1) % UB_QLOCK_NUM;
480 spin_unlock_irqrestore(&ub_lock, flags);
481 return ret;
482 }
483
484 /*
485 * Downcount for deallocation. This rides on two assumptions:
486 * - once something is poisoned, its refcount cannot grow
487 * - opens cannot happen at this time (del_gendisk was done)
488 * If the above is true, we can drop the lock, which we need for
489 * blk_cleanup_queue(): the silly thing may attempt to sleep.
490 * [Actually, it never needs to sleep for us, but it calls might_sleep()]
491 */
492 static void ub_put(struct ub_dev *sc)
493 {
494 unsigned long flags;
495
496 spin_lock_irqsave(&ub_lock, flags);
497 --sc->openc;
498 if (sc->openc == 0 && atomic_read(&sc->poison)) {
499 spin_unlock_irqrestore(&ub_lock, flags);
500 ub_cleanup(sc);
501 } else {
502 spin_unlock_irqrestore(&ub_lock, flags);
503 }
504 }
505
506 /*
507 * Final cleanup and deallocation.
508 */
509 static void ub_cleanup(struct ub_dev *sc)
510 {
511 struct list_head *p;
512 struct ub_lun *lun;
513 request_queue_t *q;
514
515 while (!list_empty(&sc->luns)) {
516 p = sc->luns.next;
517 lun = list_entry(p, struct ub_lun, link);
518 list_del(p);
519
520 /* I don't think queue can be NULL. But... Stolen from sx8.c */
521 if ((q = lun->disk->queue) != NULL)
522 blk_cleanup_queue(q);
523 /*
524 * If we zero disk->private_data BEFORE put_disk, we have
525 * to check for NULL all over the place in open, release,
526 * check_media and revalidate, because the block level
527 * semaphore is well inside the put_disk.
528 * But we cannot zero after the call, because *disk is gone.
529 * The sd.c is blatantly racy in this area.
530 */
531 /* disk->private_data = NULL; */
532 put_disk(lun->disk);
533 lun->disk = NULL;
534
535 ub_id_put(lun->id);
536 kfree(lun);
537 }
538
539 usb_set_intfdata(sc->intf, NULL);
540 usb_put_intf(sc->intf);
541 usb_put_dev(sc->dev);
542 kfree(sc);
543 }
544
545 /*
546 * The "command allocator".
547 */
548 static struct ub_scsi_cmd *ub_get_cmd(struct ub_lun *lun)
549 {
550 struct ub_scsi_cmd *ret;
551
552 if (lun->cmda[0])
553 return NULL;
554 ret = &lun->cmdv[0];
555 lun->cmda[0] = 1;
556 return ret;
557 }
558
559 static void ub_put_cmd(struct ub_lun *lun, struct ub_scsi_cmd *cmd)
560 {
561 if (cmd != &lun->cmdv[0]) {
562 printk(KERN_WARNING "%s: releasing a foreign cmd %p\n",
563 lun->name, cmd);
564 return;
565 }
566 if (!lun->cmda[0]) {
567 printk(KERN_WARNING "%s: releasing a free cmd\n", lun->name);
568 return;
569 }
570 lun->cmda[0] = 0;
571 }
572
573 /*
574 * The command queue.
575 */
576 static void ub_cmdq_add(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
577 {
578 struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
579
580 if (t->qlen++ == 0) {
581 t->head = cmd;
582 t->tail = cmd;
583 } else {
584 t->tail->next = cmd;
585 t->tail = cmd;
586 }
587
588 if (t->qlen > t->qmax)
589 t->qmax = t->qlen;
590 }
591
592 static void ub_cmdq_insert(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
593 {
594 struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
595
596 if (t->qlen++ == 0) {
597 t->head = cmd;
598 t->tail = cmd;
599 } else {
600 cmd->next = t->head;
601 t->head = cmd;
602 }
603
604 if (t->qlen > t->qmax)
605 t->qmax = t->qlen;
606 }
607
608 static struct ub_scsi_cmd *ub_cmdq_pop(struct ub_dev *sc)
609 {
610 struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
611 struct ub_scsi_cmd *cmd;
612
613 if (t->qlen == 0)
614 return NULL;
615 if (--t->qlen == 0)
616 t->tail = NULL;
617 cmd = t->head;
618 t->head = cmd->next;
619 cmd->next = NULL;
620 return cmd;
621 }
622
623 #define ub_cmdq_peek(sc) ((sc)->cmd_queue.head)
624
625 /*
626 * The request function is our main entry point
627 */
628
629 static void ub_request_fn(request_queue_t *q)
630 {
631 struct ub_lun *lun = q->queuedata;
632 struct request *rq;
633
634 while ((rq = elv_next_request(q)) != NULL) {
635 if (ub_request_fn_1(lun, rq) != 0) {
636 blk_stop_queue(q);
637 break;
638 }
639 }
640 }
641
642 static int ub_request_fn_1(struct ub_lun *lun, struct request *rq)
643 {
644 struct ub_dev *sc = lun->udev;
645 struct ub_scsi_cmd *cmd;
646 struct ub_request *urq;
647 int n_elem;
648
649 if (atomic_read(&sc->poison) || lun->changed) {
650 blkdev_dequeue_request(rq);
651 ub_end_rq(rq, 0);
652 return 0;
653 }
654
655 if (lun->urq.rq != NULL)
656 return -1;
657 if ((cmd = ub_get_cmd(lun)) == NULL)
658 return -1;
659 memset(cmd, 0, sizeof(struct ub_scsi_cmd));
660
661 blkdev_dequeue_request(rq);
662
663 urq = &lun->urq;
664 memset(urq, 0, sizeof(struct ub_request));
665 urq->rq = rq;
666
667 /*
668 * get scatterlist from block layer
669 */
670 n_elem = blk_rq_map_sg(lun->disk->queue, rq, &urq->sgv[0]);
671 if (n_elem < 0) {
672 printk(KERN_INFO "%s: failed request map (%d)\n",
673 lun->name, n_elem); /* P3 */
674 goto drop;
675 }
676 if (n_elem > UB_MAX_REQ_SG) { /* Paranoia */
677 printk(KERN_WARNING "%s: request with %d segments\n",
678 lun->name, n_elem);
679 goto drop;
680 }
681 urq->nsg = n_elem;
682 sc->sg_stat[n_elem < 5 ? n_elem : 5]++;
683
684 if (blk_pc_request(rq)) {
685 ub_cmd_build_packet(sc, lun, cmd, urq);
686 } else {
687 ub_cmd_build_block(sc, lun, cmd, urq);
688 }
689 cmd->state = UB_CMDST_INIT;
690 cmd->lun = lun;
691 cmd->done = ub_rw_cmd_done;
692 cmd->back = urq;
693
694 cmd->tag = sc->tagcnt++;
695 if (ub_submit_scsi(sc, cmd) != 0)
696 goto drop;
697
698 return 0;
699
700 drop:
701 ub_put_cmd(lun, cmd);
702 ub_end_rq(rq, 0);
703 return 0;
704 }
705
706 static void ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
707 struct ub_scsi_cmd *cmd, struct ub_request *urq)
708 {
709 struct request *rq = urq->rq;
710 unsigned int block, nblks;
711
712 if (rq_data_dir(rq) == WRITE)
713 cmd->dir = UB_DIR_WRITE;
714 else
715 cmd->dir = UB_DIR_READ;
716
717 cmd->nsg = urq->nsg;
718 memcpy(cmd->sgv, urq->sgv, sizeof(struct scatterlist) * cmd->nsg);
719
720 /*
721 * build the command
722 *
723 * The call to blk_queue_hardsect_size() guarantees that request
724 * is aligned, but it is given in terms of 512 byte units, always.
725 */
726 block = rq->sector >> lun->capacity.bshift;
727 nblks = rq->nr_sectors >> lun->capacity.bshift;
728
729 cmd->cdb[0] = (cmd->dir == UB_DIR_READ)? READ_10: WRITE_10;
730 /* 10-byte uses 4 bytes of LBA: 2147483648KB, 2097152MB, 2048GB */
731 cmd->cdb[2] = block >> 24;
732 cmd->cdb[3] = block >> 16;
733 cmd->cdb[4] = block >> 8;
734 cmd->cdb[5] = block;
735 cmd->cdb[7] = nblks >> 8;
736 cmd->cdb[8] = nblks;
737 cmd->cdb_len = 10;
738
739 cmd->len = rq->nr_sectors * 512;
740 }
741
742 static void ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
743 struct ub_scsi_cmd *cmd, struct ub_request *urq)
744 {
745 struct request *rq = urq->rq;
746
747 if (rq->data_len == 0) {
748 cmd->dir = UB_DIR_NONE;
749 } else {
750 if (rq_data_dir(rq) == WRITE)
751 cmd->dir = UB_DIR_WRITE;
752 else
753 cmd->dir = UB_DIR_READ;
754 }
755
756 cmd->nsg = urq->nsg;
757 memcpy(cmd->sgv, urq->sgv, sizeof(struct scatterlist) * cmd->nsg);
758
759 memcpy(&cmd->cdb, rq->cmd, rq->cmd_len);
760 cmd->cdb_len = rq->cmd_len;
761
762 cmd->len = rq->data_len;
763 }
764
765 static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
766 {
767 struct ub_lun *lun = cmd->lun;
768 struct ub_request *urq = cmd->back;
769 struct request *rq;
770 int uptodate;
771
772 rq = urq->rq;
773
774 if (cmd->error == 0) {
775 uptodate = 1;
776
777 if (blk_pc_request(rq)) {
778 if (cmd->act_len >= rq->data_len)
779 rq->data_len = 0;
780 else
781 rq->data_len -= cmd->act_len;
782 }
783 } else {
784 uptodate = 0;
785
786 if (blk_pc_request(rq)) {
787 /* UB_SENSE_SIZE is smaller than SCSI_SENSE_BUFFERSIZE */
788 memcpy(rq->sense, sc->top_sense, UB_SENSE_SIZE);
789 rq->sense_len = UB_SENSE_SIZE;
790 if (sc->top_sense[0] != 0)
791 rq->errors = SAM_STAT_CHECK_CONDITION;
792 else
793 rq->errors = DID_ERROR << 16;
794 } else {
795 if (cmd->error == -EIO) {
796 if (ub_rw_cmd_retry(sc, lun, urq, cmd) == 0)
797 return;
798 }
799 }
800 }
801
802 urq->rq = NULL;
803
804 ub_put_cmd(lun, cmd);
805 ub_end_rq(rq, uptodate);
806 blk_start_queue(lun->disk->queue);
807 }
808
809 static void ub_end_rq(struct request *rq, int uptodate)
810 {
811 end_that_request_first(rq, uptodate, rq->hard_nr_sectors);
812 end_that_request_last(rq, uptodate);
813 }
814
815 static int ub_rw_cmd_retry(struct ub_dev *sc, struct ub_lun *lun,
816 struct ub_request *urq, struct ub_scsi_cmd *cmd)
817 {
818
819 if (atomic_read(&sc->poison))
820 return -ENXIO;
821
822 ub_reset_enter(sc, urq->current_try);
823
824 if (urq->current_try >= 3)
825 return -EIO;
826 urq->current_try++;
827 /* P3 */ printk("%s: dir %c len/act %d/%d "
828 "[sense %x %02x %02x] retry %d\n",
829 sc->name, UB_DIR_CHAR(cmd->dir), cmd->len, cmd->act_len,
830 cmd->key, cmd->asc, cmd->ascq, urq->current_try);
831
832 memset(cmd, 0, sizeof(struct ub_scsi_cmd));
833 ub_cmd_build_block(sc, lun, cmd, urq);
834
835 cmd->state = UB_CMDST_INIT;
836 cmd->lun = lun;
837 cmd->done = ub_rw_cmd_done;
838 cmd->back = urq;
839
840 cmd->tag = sc->tagcnt++;
841
842 #if 0 /* Wasteful */
843 return ub_submit_scsi(sc, cmd);
844 #else
845 ub_cmdq_add(sc, cmd);
846 return 0;
847 #endif
848 }
849
850 /*
851 * Submit a regular SCSI operation (not an auto-sense).
852 *
853 * The Iron Law of Good Submit Routine is:
854 * Zero return - callback is done, Nonzero return - callback is not done.
855 * No exceptions.
856 *
857 * Host is assumed locked.
858 */
859 static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
860 {
861
862 if (cmd->state != UB_CMDST_INIT ||
863 (cmd->dir != UB_DIR_NONE && cmd->len == 0)) {
864 return -EINVAL;
865 }
866
867 ub_cmdq_add(sc, cmd);
868 /*
869 * We can call ub_scsi_dispatch(sc) right away here, but it's a little
870 * safer to jump to a tasklet, in case upper layers do something silly.
871 */
872 tasklet_schedule(&sc->tasklet);
873 return 0;
874 }
875
876 /*
877 * Submit the first URB for the queued command.
878 * This function does not deal with queueing in any way.
879 */
880 static int ub_scsi_cmd_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
881 {
882 struct bulk_cb_wrap *bcb;
883 int rc;
884
885 bcb = &sc->work_bcb;
886
887 /*
888 * ``If the allocation length is eighteen or greater, and a device
889 * server returns less than eithteen bytes of data, the application
890 * client should assume that the bytes not transferred would have been
891 * zeroes had the device server returned those bytes.''
892 *
893 * We zero sense for all commands so that when a packet request
894 * fails it does not return a stale sense.
895 */
896 memset(&sc->top_sense, 0, UB_SENSE_SIZE);
897
898 /* set up the command wrapper */
899 bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
900 bcb->Tag = cmd->tag; /* Endianness is not important */
901 bcb->DataTransferLength = cpu_to_le32(cmd->len);
902 bcb->Flags = (cmd->dir == UB_DIR_READ) ? 0x80 : 0;
903 bcb->Lun = (cmd->lun != NULL) ? cmd->lun->num : 0;
904 bcb->Length = cmd->cdb_len;
905
906 /* copy the command payload */
907 memcpy(bcb->CDB, cmd->cdb, UB_MAX_CDB_SIZE);
908
909 UB_INIT_COMPLETION(sc->work_done);
910
911 sc->last_pipe = sc->send_bulk_pipe;
912 usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->send_bulk_pipe,
913 bcb, US_BULK_CB_WRAP_LEN, ub_urb_complete, sc);
914
915 /* Fill what we shouldn't be filling, because usb-storage did so. */
916 sc->work_urb.actual_length = 0;
917 sc->work_urb.error_count = 0;
918 sc->work_urb.status = 0;
919
920 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
921 /* XXX Clear stalls */
922 ub_complete(&sc->work_done);
923 return rc;
924 }
925
926 sc->work_timer.expires = jiffies + UB_URB_TIMEOUT;
927 add_timer(&sc->work_timer);
928
929 cmd->state = UB_CMDST_CMD;
930 return 0;
931 }
932
933 /*
934 * Timeout handler.
935 */
936 static void ub_urb_timeout(unsigned long arg)
937 {
938 struct ub_dev *sc = (struct ub_dev *) arg;
939 unsigned long flags;
940
941 spin_lock_irqsave(sc->lock, flags);
942 if (!ub_is_completed(&sc->work_done))
943 usb_unlink_urb(&sc->work_urb);
944 spin_unlock_irqrestore(sc->lock, flags);
945 }
946
947 /*
948 * Completion routine for the work URB.
949 *
950 * This can be called directly from usb_submit_urb (while we have
951 * the sc->lock taken) and from an interrupt (while we do NOT have
952 * the sc->lock taken). Therefore, bounce this off to a tasklet.
953 */
954 static void ub_urb_complete(struct urb *urb, struct pt_regs *pt)
955 {
956 struct ub_dev *sc = urb->context;
957
958 ub_complete(&sc->work_done);
959 tasklet_schedule(&sc->tasklet);
960 }
961
962 static void ub_scsi_action(unsigned long _dev)
963 {
964 struct ub_dev *sc = (struct ub_dev *) _dev;
965 unsigned long flags;
966
967 spin_lock_irqsave(sc->lock, flags);
968 ub_scsi_dispatch(sc);
969 spin_unlock_irqrestore(sc->lock, flags);
970 }
971
972 static void ub_scsi_dispatch(struct ub_dev *sc)
973 {
974 struct ub_scsi_cmd *cmd;
975 int rc;
976
977 while (!sc->reset && (cmd = ub_cmdq_peek(sc)) != NULL) {
978 if (cmd->state == UB_CMDST_DONE) {
979 ub_cmdq_pop(sc);
980 (*cmd->done)(sc, cmd);
981 } else if (cmd->state == UB_CMDST_INIT) {
982 if ((rc = ub_scsi_cmd_start(sc, cmd)) == 0)
983 break;
984 cmd->error = rc;
985 cmd->state = UB_CMDST_DONE;
986 } else {
987 if (!ub_is_completed(&sc->work_done))
988 break;
989 del_timer(&sc->work_timer);
990 ub_scsi_urb_compl(sc, cmd);
991 }
992 }
993 }
994
995 static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
996 {
997 struct urb *urb = &sc->work_urb;
998 struct bulk_cs_wrap *bcs;
999 int len;
1000 int rc;
1001
1002 if (atomic_read(&sc->poison)) {
1003 ub_state_done(sc, cmd, -ENODEV);
1004 return;
1005 }
1006
1007 if (cmd->state == UB_CMDST_CLEAR) {
1008 if (urb->status == -EPIPE) {
1009 /*
1010 * STALL while clearning STALL.
1011 * The control pipe clears itself - nothing to do.
1012 */
1013 printk(KERN_NOTICE "%s: stall on control pipe\n",
1014 sc->name);
1015 goto Bad_End;
1016 }
1017
1018 /*
1019 * We ignore the result for the halt clear.
1020 */
1021
1022 /* reset the endpoint toggle */
1023 usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
1024 usb_pipeout(sc->last_pipe), 0);
1025
1026 ub_state_sense(sc, cmd);
1027
1028 } else if (cmd->state == UB_CMDST_CLR2STS) {
1029 if (urb->status == -EPIPE) {
1030 printk(KERN_NOTICE "%s: stall on control pipe\n",
1031 sc->name);
1032 goto Bad_End;
1033 }
1034
1035 /*
1036 * We ignore the result for the halt clear.
1037 */
1038
1039 /* reset the endpoint toggle */
1040 usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
1041 usb_pipeout(sc->last_pipe), 0);
1042
1043 ub_state_stat(sc, cmd);
1044
1045 } else if (cmd->state == UB_CMDST_CLRRS) {
1046 if (urb->status == -EPIPE) {
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 /* reset the endpoint toggle */
1057 usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
1058 usb_pipeout(sc->last_pipe), 0);
1059
1060 ub_state_stat_counted(sc, cmd);
1061
1062 } else if (cmd->state == UB_CMDST_CMD) {
1063 switch (urb->status) {
1064 case 0:
1065 break;
1066 case -EOVERFLOW:
1067 goto Bad_End;
1068 case -EPIPE:
1069 rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1070 if (rc != 0) {
1071 printk(KERN_NOTICE "%s: "
1072 "unable to submit clear (%d)\n",
1073 sc->name, rc);
1074 /*
1075 * This is typically ENOMEM or some other such shit.
1076 * Retrying is pointless. Just do Bad End on it...
1077 */
1078 ub_state_done(sc, cmd, rc);
1079 return;
1080 }
1081 cmd->state = UB_CMDST_CLEAR;
1082 return;
1083 case -ESHUTDOWN: /* unplug */
1084 case -EILSEQ: /* unplug timeout on uhci */
1085 ub_state_done(sc, cmd, -ENODEV);
1086 return;
1087 default:
1088 goto Bad_End;
1089 }
1090 if (urb->actual_length != US_BULK_CB_WRAP_LEN) {
1091 goto Bad_End;
1092 }
1093
1094 if (cmd->dir == UB_DIR_NONE || cmd->nsg < 1) {
1095 ub_state_stat(sc, cmd);
1096 return;
1097 }
1098
1099 // udelay(125); // usb-storage has this
1100 ub_data_start(sc, cmd);
1101
1102 } else if (cmd->state == UB_CMDST_DATA) {
1103 if (urb->status == -EPIPE) {
1104 rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1105 if (rc != 0) {
1106 printk(KERN_NOTICE "%s: "
1107 "unable to submit clear (%d)\n",
1108 sc->name, rc);
1109 ub_state_done(sc, cmd, rc);
1110 return;
1111 }
1112 cmd->state = UB_CMDST_CLR2STS;
1113 return;
1114 }
1115 if (urb->status == -EOVERFLOW) {
1116 /*
1117 * A babble? Failure, but we must transfer CSW now.
1118 */
1119 cmd->error = -EOVERFLOW; /* A cheap trick... */
1120 ub_state_stat(sc, cmd);
1121 return;
1122 }
1123
1124 if (cmd->dir == UB_DIR_WRITE) {
1125 /*
1126 * Do not continue writes in case of a failure.
1127 * Doing so would cause sectors to be mixed up,
1128 * which is worse than sectors lost.
1129 *
1130 * We must try to read the CSW, or many devices
1131 * get confused.
1132 */
1133 len = urb->actual_length;
1134 if (urb->status != 0 ||
1135 len != cmd->sgv[cmd->current_sg].length) {
1136 cmd->act_len += len;
1137
1138 cmd->error = -EIO;
1139 ub_state_stat(sc, cmd);
1140 return;
1141 }
1142
1143 } else {
1144 /*
1145 * If an error occurs on read, we record it, and
1146 * continue to fetch data in order to avoid bubble.
1147 *
1148 * As a small shortcut, we stop if we detect that
1149 * a CSW mixed into data.
1150 */
1151 if (urb->status != 0)
1152 cmd->error = -EIO;
1153
1154 len = urb->actual_length;
1155 if (urb->status != 0 ||
1156 len != cmd->sgv[cmd->current_sg].length) {
1157 if ((len & 0x1FF) == US_BULK_CS_WRAP_LEN)
1158 goto Bad_End;
1159 }
1160 }
1161
1162 cmd->act_len += urb->actual_length;
1163
1164 if (++cmd->current_sg < cmd->nsg) {
1165 ub_data_start(sc, cmd);
1166 return;
1167 }
1168 ub_state_stat(sc, cmd);
1169
1170 } else if (cmd->state == UB_CMDST_STAT) {
1171 if (urb->status == -EPIPE) {
1172 rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1173 if (rc != 0) {
1174 printk(KERN_NOTICE "%s: "
1175 "unable to submit clear (%d)\n",
1176 sc->name, rc);
1177 ub_state_done(sc, cmd, rc);
1178 return;
1179 }
1180
1181 /*
1182 * Having a stall when getting CSW is an error, so
1183 * make sure uppper levels are not oblivious to it.
1184 */
1185 cmd->error = -EIO; /* A cheap trick... */
1186
1187 cmd->state = UB_CMDST_CLRRS;
1188 return;
1189 }
1190
1191 /* Catch everything, including -EOVERFLOW and other nasties. */
1192 if (urb->status != 0)
1193 goto Bad_End;
1194
1195 if (urb->actual_length == 0) {
1196 ub_state_stat_counted(sc, cmd);
1197 return;
1198 }
1199
1200 /*
1201 * Check the returned Bulk protocol status.
1202 * The status block has to be validated first.
1203 */
1204
1205 bcs = &sc->work_bcs;
1206
1207 if (sc->signature == cpu_to_le32(0)) {
1208 /*
1209 * This is the first reply, so do not perform the check.
1210 * Instead, remember the signature the device uses
1211 * for future checks. But do not allow a nul.
1212 */
1213 sc->signature = bcs->Signature;
1214 if (sc->signature == cpu_to_le32(0)) {
1215 ub_state_stat_counted(sc, cmd);
1216 return;
1217 }
1218 } else {
1219 if (bcs->Signature != sc->signature) {
1220 ub_state_stat_counted(sc, cmd);
1221 return;
1222 }
1223 }
1224
1225 if (bcs->Tag != cmd->tag) {
1226 /*
1227 * This usually happens when we disagree with the
1228 * device's microcode about something. For instance,
1229 * a few of them throw this after timeouts. They buffer
1230 * commands and reply at commands we timed out before.
1231 * Without flushing these replies we loop forever.
1232 */
1233 ub_state_stat_counted(sc, cmd);
1234 return;
1235 }
1236
1237 len = le32_to_cpu(bcs->Residue);
1238 if (len != cmd->len - cmd->act_len) {
1239 /*
1240 * It is all right to transfer less, the caller has
1241 * to check. But it's not all right if the device
1242 * counts disagree with our counts.
1243 */
1244 /* P3 */ printk("%s: resid %d len %d act %d\n",
1245 sc->name, len, cmd->len, cmd->act_len);
1246 goto Bad_End;
1247 }
1248
1249 switch (bcs->Status) {
1250 case US_BULK_STAT_OK:
1251 break;
1252 case US_BULK_STAT_FAIL:
1253 ub_state_sense(sc, cmd);
1254 return;
1255 case US_BULK_STAT_PHASE:
1256 /* P3 */ printk("%s: status PHASE\n", sc->name);
1257 goto Bad_End;
1258 default:
1259 printk(KERN_INFO "%s: unknown CSW status 0x%x\n",
1260 sc->name, bcs->Status);
1261 ub_state_done(sc, cmd, -EINVAL);
1262 return;
1263 }
1264
1265 /* Not zeroing error to preserve a babble indicator */
1266 if (cmd->error != 0) {
1267 ub_state_sense(sc, cmd);
1268 return;
1269 }
1270 cmd->state = UB_CMDST_DONE;
1271 ub_cmdq_pop(sc);
1272 (*cmd->done)(sc, cmd);
1273
1274 } else if (cmd->state == UB_CMDST_SENSE) {
1275 ub_state_done(sc, cmd, -EIO);
1276
1277 } else {
1278 printk(KERN_WARNING "%s: "
1279 "wrong command state %d\n",
1280 sc->name, cmd->state);
1281 ub_state_done(sc, cmd, -EINVAL);
1282 return;
1283 }
1284 return;
1285
1286 Bad_End: /* Little Excel is dead */
1287 ub_state_done(sc, cmd, -EIO);
1288 }
1289
1290 /*
1291 * Factorization helper for the command state machine:
1292 * Initiate a data segment transfer.
1293 */
1294 static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1295 {
1296 struct scatterlist *sg = &cmd->sgv[cmd->current_sg];
1297 int pipe;
1298 int rc;
1299
1300 UB_INIT_COMPLETION(sc->work_done);
1301
1302 if (cmd->dir == UB_DIR_READ)
1303 pipe = sc->recv_bulk_pipe;
1304 else
1305 pipe = sc->send_bulk_pipe;
1306 sc->last_pipe = pipe;
1307 usb_fill_bulk_urb(&sc->work_urb, sc->dev, pipe,
1308 page_address(sg->page) + sg->offset, sg->length,
1309 ub_urb_complete, sc);
1310 sc->work_urb.actual_length = 0;
1311 sc->work_urb.error_count = 0;
1312 sc->work_urb.status = 0;
1313
1314 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1315 /* XXX Clear stalls */
1316 ub_complete(&sc->work_done);
1317 ub_state_done(sc, cmd, rc);
1318 return;
1319 }
1320
1321 sc->work_timer.expires = jiffies + UB_DATA_TIMEOUT;
1322 add_timer(&sc->work_timer);
1323
1324 cmd->state = UB_CMDST_DATA;
1325 }
1326
1327 /*
1328 * Factorization helper for the command state machine:
1329 * Finish the command.
1330 */
1331 static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc)
1332 {
1333
1334 cmd->error = rc;
1335 cmd->state = UB_CMDST_DONE;
1336 ub_cmdq_pop(sc);
1337 (*cmd->done)(sc, cmd);
1338 }
1339
1340 /*
1341 * Factorization helper for the command state machine:
1342 * Submit a CSW read.
1343 */
1344 static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1345 {
1346 int rc;
1347
1348 UB_INIT_COMPLETION(sc->work_done);
1349
1350 sc->last_pipe = sc->recv_bulk_pipe;
1351 usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->recv_bulk_pipe,
1352 &sc->work_bcs, US_BULK_CS_WRAP_LEN, ub_urb_complete, sc);
1353 sc->work_urb.actual_length = 0;
1354 sc->work_urb.error_count = 0;
1355 sc->work_urb.status = 0;
1356
1357 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1358 /* XXX Clear stalls */
1359 ub_complete(&sc->work_done);
1360 ub_state_done(sc, cmd, rc);
1361 return -1;
1362 }
1363
1364 sc->work_timer.expires = jiffies + UB_STAT_TIMEOUT;
1365 add_timer(&sc->work_timer);
1366 return 0;
1367 }
1368
1369 /*
1370 * Factorization helper for the command state machine:
1371 * Submit a CSW read and go to STAT state.
1372 */
1373 static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1374 {
1375
1376 if (__ub_state_stat(sc, cmd) != 0)
1377 return;
1378
1379 cmd->stat_count = 0;
1380 cmd->state = UB_CMDST_STAT;
1381 }
1382
1383 /*
1384 * Factorization helper for the command state machine:
1385 * Submit a CSW read and go to STAT state with counter (along [C] path).
1386 */
1387 static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1388 {
1389
1390 if (++cmd->stat_count >= 4) {
1391 ub_state_sense(sc, cmd);
1392 return;
1393 }
1394
1395 if (__ub_state_stat(sc, cmd) != 0)
1396 return;
1397
1398 cmd->state = UB_CMDST_STAT;
1399 }
1400
1401 /*
1402 * Factorization helper for the command state machine:
1403 * Submit a REQUEST SENSE and go to SENSE state.
1404 */
1405 static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1406 {
1407 struct ub_scsi_cmd *scmd;
1408 struct scatterlist *sg;
1409 int rc;
1410
1411 if (cmd->cdb[0] == REQUEST_SENSE) {
1412 rc = -EPIPE;
1413 goto error;
1414 }
1415
1416 scmd = &sc->top_rqs_cmd;
1417 memset(scmd, 0, sizeof(struct ub_scsi_cmd));
1418 scmd->cdb[0] = REQUEST_SENSE;
1419 scmd->cdb[4] = UB_SENSE_SIZE;
1420 scmd->cdb_len = 6;
1421 scmd->dir = UB_DIR_READ;
1422 scmd->state = UB_CMDST_INIT;
1423 scmd->nsg = 1;
1424 sg = &scmd->sgv[0];
1425 sg->page = virt_to_page(sc->top_sense);
1426 sg->offset = (unsigned long)sc->top_sense & (PAGE_SIZE-1);
1427 sg->length = UB_SENSE_SIZE;
1428 scmd->len = UB_SENSE_SIZE;
1429 scmd->lun = cmd->lun;
1430 scmd->done = ub_top_sense_done;
1431 scmd->back = cmd;
1432
1433 scmd->tag = sc->tagcnt++;
1434
1435 cmd->state = UB_CMDST_SENSE;
1436
1437 ub_cmdq_insert(sc, scmd);
1438 return;
1439
1440 error:
1441 ub_state_done(sc, cmd, rc);
1442 }
1443
1444 /*
1445 * A helper for the command's state machine:
1446 * Submit a stall clear.
1447 */
1448 static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
1449 int stalled_pipe)
1450 {
1451 int endp;
1452 struct usb_ctrlrequest *cr;
1453 int rc;
1454
1455 endp = usb_pipeendpoint(stalled_pipe);
1456 if (usb_pipein (stalled_pipe))
1457 endp |= USB_DIR_IN;
1458
1459 cr = &sc->work_cr;
1460 cr->bRequestType = USB_RECIP_ENDPOINT;
1461 cr->bRequest = USB_REQ_CLEAR_FEATURE;
1462 cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
1463 cr->wIndex = cpu_to_le16(endp);
1464 cr->wLength = cpu_to_le16(0);
1465
1466 UB_INIT_COMPLETION(sc->work_done);
1467
1468 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
1469 (unsigned char*) cr, NULL, 0, ub_urb_complete, sc);
1470 sc->work_urb.actual_length = 0;
1471 sc->work_urb.error_count = 0;
1472 sc->work_urb.status = 0;
1473
1474 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1475 ub_complete(&sc->work_done);
1476 return rc;
1477 }
1478
1479 sc->work_timer.expires = jiffies + UB_CTRL_TIMEOUT;
1480 add_timer(&sc->work_timer);
1481 return 0;
1482 }
1483
1484 /*
1485 */
1486 static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd)
1487 {
1488 unsigned char *sense = sc->top_sense;
1489 struct ub_scsi_cmd *cmd;
1490
1491 /*
1492 * Find the command which triggered the unit attention or a check,
1493 * save the sense into it, and advance its state machine.
1494 */
1495 if ((cmd = ub_cmdq_peek(sc)) == NULL) {
1496 printk(KERN_WARNING "%s: sense done while idle\n", sc->name);
1497 return;
1498 }
1499 if (cmd != scmd->back) {
1500 printk(KERN_WARNING "%s: "
1501 "sense done for wrong command 0x%x\n",
1502 sc->name, cmd->tag);
1503 return;
1504 }
1505 if (cmd->state != UB_CMDST_SENSE) {
1506 printk(KERN_WARNING "%s: "
1507 "sense done with bad cmd state %d\n",
1508 sc->name, cmd->state);
1509 return;
1510 }
1511
1512 /*
1513 * Ignoring scmd->act_len, because the buffer was pre-zeroed.
1514 */
1515 cmd->key = sense[2] & 0x0F;
1516 cmd->asc = sense[12];
1517 cmd->ascq = sense[13];
1518
1519 ub_scsi_urb_compl(sc, cmd);
1520 }
1521
1522 /*
1523 * Reset management
1524 * XXX Move usb_reset_device to khubd. Hogging kevent is not a good thing.
1525 * XXX Make usb_sync_reset asynchronous.
1526 */
1527
1528 static void ub_reset_enter(struct ub_dev *sc, int try)
1529 {
1530
1531 if (sc->reset) {
1532 /* This happens often on multi-LUN devices. */
1533 return;
1534 }
1535 sc->reset = try + 1;
1536
1537 #if 0 /* Not needed because the disconnect waits for us. */
1538 unsigned long flags;
1539 spin_lock_irqsave(&ub_lock, flags);
1540 sc->openc++;
1541 spin_unlock_irqrestore(&ub_lock, flags);
1542 #endif
1543
1544 #if 0 /* We let them stop themselves. */
1545 struct list_head *p;
1546 struct ub_lun *lun;
1547 list_for_each(p, &sc->luns) {
1548 lun = list_entry(p, struct ub_lun, link);
1549 blk_stop_queue(lun->disk->queue);
1550 }
1551 #endif
1552
1553 schedule_work(&sc->reset_work);
1554 }
1555
1556 static void ub_reset_task(void *arg)
1557 {
1558 struct ub_dev *sc = arg;
1559 unsigned long flags;
1560 struct list_head *p;
1561 struct ub_lun *lun;
1562 int lkr, rc;
1563
1564 if (!sc->reset) {
1565 printk(KERN_WARNING "%s: Running reset unrequested\n",
1566 sc->name);
1567 return;
1568 }
1569
1570 if (atomic_read(&sc->poison)) {
1571 printk(KERN_NOTICE "%s: Not resetting disconnected device\n",
1572 sc->name); /* P3 This floods. Remove soon. XXX */
1573 } else if ((sc->reset & 1) == 0) {
1574 ub_sync_reset(sc);
1575 msleep(700); /* usb-storage sleeps 6s (!) */
1576 ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
1577 ub_probe_clear_stall(sc, sc->send_bulk_pipe);
1578 } else if (sc->dev->actconfig->desc.bNumInterfaces != 1) {
1579 printk(KERN_NOTICE "%s: Not resetting multi-interface device\n",
1580 sc->name); /* P3 This floods. Remove soon. XXX */
1581 } else {
1582 if ((lkr = usb_lock_device_for_reset(sc->dev, sc->intf)) < 0) {
1583 printk(KERN_NOTICE
1584 "%s: usb_lock_device_for_reset failed (%d)\n",
1585 sc->name, lkr);
1586 } else {
1587 rc = usb_reset_device(sc->dev);
1588 if (rc < 0) {
1589 printk(KERN_NOTICE "%s: "
1590 "usb_lock_device_for_reset failed (%d)\n",
1591 sc->name, rc);
1592 }
1593
1594 if (lkr)
1595 usb_unlock_device(sc->dev);
1596 }
1597 }
1598
1599 /*
1600 * In theory, no commands can be running while reset is active,
1601 * so nobody can ask for another reset, and so we do not need any
1602 * queues of resets or anything. We do need a spinlock though,
1603 * to interact with block layer.
1604 */
1605 spin_lock_irqsave(sc->lock, flags);
1606 sc->reset = 0;
1607 tasklet_schedule(&sc->tasklet);
1608 list_for_each(p, &sc->luns) {
1609 lun = list_entry(p, struct ub_lun, link);
1610 blk_start_queue(lun->disk->queue);
1611 }
1612 wake_up(&sc->reset_wait);
1613 spin_unlock_irqrestore(sc->lock, flags);
1614 }
1615
1616 /*
1617 * This is called from a process context.
1618 */
1619 static void ub_revalidate(struct ub_dev *sc, struct ub_lun *lun)
1620 {
1621
1622 lun->readonly = 0; /* XXX Query this from the device */
1623
1624 lun->capacity.nsec = 0;
1625 lun->capacity.bsize = 512;
1626 lun->capacity.bshift = 0;
1627
1628 if (ub_sync_tur(sc, lun) != 0)
1629 return; /* Not ready */
1630 lun->changed = 0;
1631
1632 if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
1633 /*
1634 * The retry here means something is wrong, either with the
1635 * device, with the transport, or with our code.
1636 * We keep this because sd.c has retries for capacity.
1637 */
1638 if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
1639 lun->capacity.nsec = 0;
1640 lun->capacity.bsize = 512;
1641 lun->capacity.bshift = 0;
1642 }
1643 }
1644 }
1645
1646 /*
1647 * The open funcion.
1648 * This is mostly needed to keep refcounting, but also to support
1649 * media checks on removable media drives.
1650 */
1651 static int ub_bd_open(struct inode *inode, struct file *filp)
1652 {
1653 struct gendisk *disk = inode->i_bdev->bd_disk;
1654 struct ub_lun *lun = disk->private_data;
1655 struct ub_dev *sc = lun->udev;
1656 unsigned long flags;
1657 int rc;
1658
1659 spin_lock_irqsave(&ub_lock, flags);
1660 if (atomic_read(&sc->poison)) {
1661 spin_unlock_irqrestore(&ub_lock, flags);
1662 return -ENXIO;
1663 }
1664 sc->openc++;
1665 spin_unlock_irqrestore(&ub_lock, flags);
1666
1667 if (lun->removable || lun->readonly)
1668 check_disk_change(inode->i_bdev);
1669
1670 /*
1671 * The sd.c considers ->media_present and ->changed not equivalent,
1672 * under some pretty murky conditions (a failure of READ CAPACITY).
1673 * We may need it one day.
1674 */
1675 if (lun->removable && lun->changed && !(filp->f_flags & O_NDELAY)) {
1676 rc = -ENOMEDIUM;
1677 goto err_open;
1678 }
1679
1680 if (lun->readonly && (filp->f_mode & FMODE_WRITE)) {
1681 rc = -EROFS;
1682 goto err_open;
1683 }
1684
1685 return 0;
1686
1687 err_open:
1688 ub_put(sc);
1689 return rc;
1690 }
1691
1692 /*
1693 */
1694 static int ub_bd_release(struct inode *inode, struct file *filp)
1695 {
1696 struct gendisk *disk = inode->i_bdev->bd_disk;
1697 struct ub_lun *lun = disk->private_data;
1698 struct ub_dev *sc = lun->udev;
1699
1700 ub_put(sc);
1701 return 0;
1702 }
1703
1704 /*
1705 * The ioctl interface.
1706 */
1707 static int ub_bd_ioctl(struct inode *inode, struct file *filp,
1708 unsigned int cmd, unsigned long arg)
1709 {
1710 struct gendisk *disk = inode->i_bdev->bd_disk;
1711 void __user *usermem = (void __user *) arg;
1712
1713 return scsi_cmd_ioctl(filp, disk, cmd, usermem);
1714 }
1715
1716 /*
1717 * This is called once a new disk was seen by the block layer or by ub_probe().
1718 * The main onjective here is to discover the features of the media such as
1719 * the capacity, read-only status, etc. USB storage generally does not
1720 * need to be spun up, but if we needed it, this would be the place.
1721 *
1722 * This call can sleep.
1723 *
1724 * The return code is not used.
1725 */
1726 static int ub_bd_revalidate(struct gendisk *disk)
1727 {
1728 struct ub_lun *lun = disk->private_data;
1729
1730 ub_revalidate(lun->udev, lun);
1731
1732 /* XXX Support sector size switching like in sr.c */
1733 blk_queue_hardsect_size(disk->queue, lun->capacity.bsize);
1734 set_capacity(disk, lun->capacity.nsec);
1735 // set_disk_ro(sdkp->disk, lun->readonly);
1736
1737 return 0;
1738 }
1739
1740 /*
1741 * The check is called by the block layer to verify if the media
1742 * is still available. It is supposed to be harmless, lightweight and
1743 * non-intrusive in case the media was not changed.
1744 *
1745 * This call can sleep.
1746 *
1747 * The return code is bool!
1748 */
1749 static int ub_bd_media_changed(struct gendisk *disk)
1750 {
1751 struct ub_lun *lun = disk->private_data;
1752
1753 if (!lun->removable)
1754 return 0;
1755
1756 /*
1757 * We clean checks always after every command, so this is not
1758 * as dangerous as it looks. If the TEST_UNIT_READY fails here,
1759 * the device is actually not ready with operator or software
1760 * intervention required. One dangerous item might be a drive which
1761 * spins itself down, and come the time to write dirty pages, this
1762 * will fail, then block layer discards the data. Since we never
1763 * spin drives up, such devices simply cannot be used with ub anyway.
1764 */
1765 if (ub_sync_tur(lun->udev, lun) != 0) {
1766 lun->changed = 1;
1767 return 1;
1768 }
1769
1770 return lun->changed;
1771 }
1772
1773 static struct block_device_operations ub_bd_fops = {
1774 .owner = THIS_MODULE,
1775 .open = ub_bd_open,
1776 .release = ub_bd_release,
1777 .ioctl = ub_bd_ioctl,
1778 .media_changed = ub_bd_media_changed,
1779 .revalidate_disk = ub_bd_revalidate,
1780 };
1781
1782 /*
1783 * Common ->done routine for commands executed synchronously.
1784 */
1785 static void ub_probe_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1786 {
1787 struct completion *cop = cmd->back;
1788 complete(cop);
1789 }
1790
1791 /*
1792 * Test if the device has a check condition on it, synchronously.
1793 */
1794 static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun)
1795 {
1796 struct ub_scsi_cmd *cmd;
1797 enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) };
1798 unsigned long flags;
1799 struct completion compl;
1800 int rc;
1801
1802 init_completion(&compl);
1803
1804 rc = -ENOMEM;
1805 if ((cmd = kzalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
1806 goto err_alloc;
1807
1808 cmd->cdb[0] = TEST_UNIT_READY;
1809 cmd->cdb_len = 6;
1810 cmd->dir = UB_DIR_NONE;
1811 cmd->state = UB_CMDST_INIT;
1812 cmd->lun = lun; /* This may be NULL, but that's ok */
1813 cmd->done = ub_probe_done;
1814 cmd->back = &compl;
1815
1816 spin_lock_irqsave(sc->lock, flags);
1817 cmd->tag = sc->tagcnt++;
1818
1819 rc = ub_submit_scsi(sc, cmd);
1820 spin_unlock_irqrestore(sc->lock, flags);
1821
1822 if (rc != 0) {
1823 printk("ub: testing ready: submit error (%d)\n", rc); /* P3 */
1824 goto err_submit;
1825 }
1826
1827 wait_for_completion(&compl);
1828
1829 rc = cmd->error;
1830
1831 if (rc == -EIO && cmd->key != 0) /* Retries for benh's key */
1832 rc = cmd->key;
1833
1834 err_submit:
1835 kfree(cmd);
1836 err_alloc:
1837 return rc;
1838 }
1839
1840 /*
1841 * Read the SCSI capacity synchronously (for probing).
1842 */
1843 static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
1844 struct ub_capacity *ret)
1845 {
1846 struct ub_scsi_cmd *cmd;
1847 struct scatterlist *sg;
1848 char *p;
1849 enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) + 8 };
1850 unsigned long flags;
1851 unsigned int bsize, shift;
1852 unsigned long nsec;
1853 struct completion compl;
1854 int rc;
1855
1856 init_completion(&compl);
1857
1858 rc = -ENOMEM;
1859 if ((cmd = kzalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
1860 goto err_alloc;
1861 p = (char *)cmd + sizeof(struct ub_scsi_cmd);
1862
1863 cmd->cdb[0] = 0x25;
1864 cmd->cdb_len = 10;
1865 cmd->dir = UB_DIR_READ;
1866 cmd->state = UB_CMDST_INIT;
1867 cmd->nsg = 1;
1868 sg = &cmd->sgv[0];
1869 sg->page = virt_to_page(p);
1870 sg->offset = (unsigned long)p & (PAGE_SIZE-1);
1871 sg->length = 8;
1872 cmd->len = 8;
1873 cmd->lun = lun;
1874 cmd->done = ub_probe_done;
1875 cmd->back = &compl;
1876
1877 spin_lock_irqsave(sc->lock, flags);
1878 cmd->tag = sc->tagcnt++;
1879
1880 rc = ub_submit_scsi(sc, cmd);
1881 spin_unlock_irqrestore(sc->lock, flags);
1882
1883 if (rc != 0) {
1884 printk("ub: reading capacity: submit error (%d)\n", rc); /* P3 */
1885 goto err_submit;
1886 }
1887
1888 wait_for_completion(&compl);
1889
1890 if (cmd->error != 0) {
1891 printk("ub: reading capacity: error %d\n", cmd->error); /* P3 */
1892 rc = -EIO;
1893 goto err_read;
1894 }
1895 if (cmd->act_len != 8) {
1896 printk("ub: reading capacity: size %d\n", cmd->act_len); /* P3 */
1897 rc = -EIO;
1898 goto err_read;
1899 }
1900
1901 /* sd.c special-cases sector size of 0 to mean 512. Needed? Safe? */
1902 nsec = be32_to_cpu(*(__be32 *)p) + 1;
1903 bsize = be32_to_cpu(*(__be32 *)(p + 4));
1904 switch (bsize) {
1905 case 512: shift = 0; break;
1906 case 1024: shift = 1; break;
1907 case 2048: shift = 2; break;
1908 case 4096: shift = 3; break;
1909 default:
1910 printk("ub: Bad sector size %u\n", bsize); /* P3 */
1911 rc = -EDOM;
1912 goto err_inv_bsize;
1913 }
1914
1915 ret->bsize = bsize;
1916 ret->bshift = shift;
1917 ret->nsec = nsec << shift;
1918 rc = 0;
1919
1920 err_inv_bsize:
1921 err_read:
1922 err_submit:
1923 kfree(cmd);
1924 err_alloc:
1925 return rc;
1926 }
1927
1928 /*
1929 */
1930 static void ub_probe_urb_complete(struct urb *urb, struct pt_regs *pt)
1931 {
1932 struct completion *cop = urb->context;
1933 complete(cop);
1934 }
1935
1936 static void ub_probe_timeout(unsigned long arg)
1937 {
1938 struct completion *cop = (struct completion *) arg;
1939 complete(cop);
1940 }
1941
1942 /*
1943 * Reset with a Bulk reset.
1944 */
1945 static int ub_sync_reset(struct ub_dev *sc)
1946 {
1947 int ifnum = sc->intf->cur_altsetting->desc.bInterfaceNumber;
1948 struct usb_ctrlrequest *cr;
1949 struct completion compl;
1950 struct timer_list timer;
1951 int rc;
1952
1953 init_completion(&compl);
1954
1955 cr = &sc->work_cr;
1956 cr->bRequestType = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
1957 cr->bRequest = US_BULK_RESET_REQUEST;
1958 cr->wValue = cpu_to_le16(0);
1959 cr->wIndex = cpu_to_le16(ifnum);
1960 cr->wLength = cpu_to_le16(0);
1961
1962 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
1963 (unsigned char*) cr, NULL, 0, ub_probe_urb_complete, &compl);
1964 sc->work_urb.actual_length = 0;
1965 sc->work_urb.error_count = 0;
1966 sc->work_urb.status = 0;
1967
1968 if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
1969 printk(KERN_WARNING
1970 "%s: Unable to submit a bulk reset (%d)\n", sc->name, rc);
1971 return rc;
1972 }
1973
1974 init_timer(&timer);
1975 timer.function = ub_probe_timeout;
1976 timer.data = (unsigned long) &compl;
1977 timer.expires = jiffies + UB_CTRL_TIMEOUT;
1978 add_timer(&timer);
1979
1980 wait_for_completion(&compl);
1981
1982 del_timer_sync(&timer);
1983 usb_kill_urb(&sc->work_urb);
1984
1985 return sc->work_urb.status;
1986 }
1987
1988 /*
1989 * Get number of LUNs by the way of Bulk GetMaxLUN command.
1990 */
1991 static int ub_sync_getmaxlun(struct ub_dev *sc)
1992 {
1993 int ifnum = sc->intf->cur_altsetting->desc.bInterfaceNumber;
1994 unsigned char *p;
1995 enum { ALLOC_SIZE = 1 };
1996 struct usb_ctrlrequest *cr;
1997 struct completion compl;
1998 struct timer_list timer;
1999 int nluns;
2000 int rc;
2001
2002 init_completion(&compl);
2003
2004 rc = -ENOMEM;
2005 if ((p = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
2006 goto err_alloc;
2007 *p = 55;
2008
2009 cr = &sc->work_cr;
2010 cr->bRequestType = USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE;
2011 cr->bRequest = US_BULK_GET_MAX_LUN;
2012 cr->wValue = cpu_to_le16(0);
2013 cr->wIndex = cpu_to_le16(ifnum);
2014 cr->wLength = cpu_to_le16(1);
2015
2016 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->recv_ctrl_pipe,
2017 (unsigned char*) cr, p, 1, ub_probe_urb_complete, &compl);
2018 sc->work_urb.actual_length = 0;
2019 sc->work_urb.error_count = 0;
2020 sc->work_urb.status = 0;
2021
2022 if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
2023 if (rc == -EPIPE) {
2024 printk("%s: Stall submitting GetMaxLUN, using 1 LUN\n",
2025 sc->name); /* P3 */
2026 } else {
2027 printk(KERN_NOTICE
2028 "%s: Unable to submit GetMaxLUN (%d)\n",
2029 sc->name, rc);
2030 }
2031 goto err_submit;
2032 }
2033
2034 init_timer(&timer);
2035 timer.function = ub_probe_timeout;
2036 timer.data = (unsigned long) &compl;
2037 timer.expires = jiffies + UB_CTRL_TIMEOUT;
2038 add_timer(&timer);
2039
2040 wait_for_completion(&compl);
2041
2042 del_timer_sync(&timer);
2043 usb_kill_urb(&sc->work_urb);
2044
2045 if ((rc = sc->work_urb.status) < 0) {
2046 if (rc == -EPIPE) {
2047 printk("%s: Stall at GetMaxLUN, using 1 LUN\n",
2048 sc->name); /* P3 */
2049 } else {
2050 printk(KERN_NOTICE
2051 "%s: Error at GetMaxLUN (%d)\n",
2052 sc->name, rc);
2053 }
2054 goto err_io;
2055 }
2056
2057 if (sc->work_urb.actual_length != 1) {
2058 printk("%s: GetMaxLUN returned %d bytes\n", sc->name,
2059 sc->work_urb.actual_length); /* P3 */
2060 nluns = 0;
2061 } else {
2062 if ((nluns = *p) == 55) {
2063 nluns = 0;
2064 } else {
2065 /* GetMaxLUN returns the maximum LUN number */
2066 nluns += 1;
2067 if (nluns > UB_MAX_LUNS)
2068 nluns = UB_MAX_LUNS;
2069 }
2070 printk("%s: GetMaxLUN returned %d, using %d LUNs\n", sc->name,
2071 *p, nluns); /* P3 */
2072 }
2073
2074 kfree(p);
2075 return nluns;
2076
2077 err_io:
2078 err_submit:
2079 kfree(p);
2080 err_alloc:
2081 return rc;
2082 }
2083
2084 /*
2085 * Clear initial stalls.
2086 */
2087 static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe)
2088 {
2089 int endp;
2090 struct usb_ctrlrequest *cr;
2091 struct completion compl;
2092 struct timer_list timer;
2093 int rc;
2094
2095 init_completion(&compl);
2096
2097 endp = usb_pipeendpoint(stalled_pipe);
2098 if (usb_pipein (stalled_pipe))
2099 endp |= USB_DIR_IN;
2100
2101 cr = &sc->work_cr;
2102 cr->bRequestType = USB_RECIP_ENDPOINT;
2103 cr->bRequest = USB_REQ_CLEAR_FEATURE;
2104 cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
2105 cr->wIndex = cpu_to_le16(endp);
2106 cr->wLength = cpu_to_le16(0);
2107
2108 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
2109 (unsigned char*) cr, NULL, 0, ub_probe_urb_complete, &compl);
2110 sc->work_urb.actual_length = 0;
2111 sc->work_urb.error_count = 0;
2112 sc->work_urb.status = 0;
2113
2114 if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
2115 printk(KERN_WARNING
2116 "%s: Unable to submit a probe clear (%d)\n", sc->name, rc);
2117 return rc;
2118 }
2119
2120 init_timer(&timer);
2121 timer.function = ub_probe_timeout;
2122 timer.data = (unsigned long) &compl;
2123 timer.expires = jiffies + UB_CTRL_TIMEOUT;
2124 add_timer(&timer);
2125
2126 wait_for_completion(&compl);
2127
2128 del_timer_sync(&timer);
2129 usb_kill_urb(&sc->work_urb);
2130
2131 /* reset the endpoint toggle */
2132 usb_settoggle(sc->dev, endp, usb_pipeout(sc->last_pipe), 0);
2133
2134 return 0;
2135 }
2136
2137 /*
2138 * Get the pipe settings.
2139 */
2140 static int ub_get_pipes(struct ub_dev *sc, struct usb_device *dev,
2141 struct usb_interface *intf)
2142 {
2143 struct usb_host_interface *altsetting = intf->cur_altsetting;
2144 struct usb_endpoint_descriptor *ep_in = NULL;
2145 struct usb_endpoint_descriptor *ep_out = NULL;
2146 struct usb_endpoint_descriptor *ep;
2147 int i;
2148
2149 /*
2150 * Find the endpoints we need.
2151 * We are expecting a minimum of 2 endpoints - in and out (bulk).
2152 * We will ignore any others.
2153 */
2154 for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
2155 ep = &altsetting->endpoint[i].desc;
2156
2157 /* Is it a BULK endpoint? */
2158 if ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
2159 == USB_ENDPOINT_XFER_BULK) {
2160 /* BULK in or out? */
2161 if (ep->bEndpointAddress & USB_DIR_IN)
2162 ep_in = ep;
2163 else
2164 ep_out = ep;
2165 }
2166 }
2167
2168 if (ep_in == NULL || ep_out == NULL) {
2169 printk(KERN_NOTICE "%s: failed endpoint check\n",
2170 sc->name);
2171 return -ENODEV;
2172 }
2173
2174 /* Calculate and store the pipe values */
2175 sc->send_ctrl_pipe = usb_sndctrlpipe(dev, 0);
2176 sc->recv_ctrl_pipe = usb_rcvctrlpipe(dev, 0);
2177 sc->send_bulk_pipe = usb_sndbulkpipe(dev,
2178 ep_out->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2179 sc->recv_bulk_pipe = usb_rcvbulkpipe(dev,
2180 ep_in->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2181
2182 return 0;
2183 }
2184
2185 /*
2186 * Probing is done in the process context, which allows us to cheat
2187 * and not to build a state machine for the discovery.
2188 */
2189 static int ub_probe(struct usb_interface *intf,
2190 const struct usb_device_id *dev_id)
2191 {
2192 struct ub_dev *sc;
2193 int nluns;
2194 int rc;
2195 int i;
2196
2197 if (usb_usual_check_type(dev_id, USB_US_TYPE_UB))
2198 return -ENXIO;
2199
2200 rc = -ENOMEM;
2201 if ((sc = kzalloc(sizeof(struct ub_dev), GFP_KERNEL)) == NULL)
2202 goto err_core;
2203 sc->lock = ub_next_lock();
2204 INIT_LIST_HEAD(&sc->luns);
2205 usb_init_urb(&sc->work_urb);
2206 tasklet_init(&sc->tasklet, ub_scsi_action, (unsigned long)sc);
2207 atomic_set(&sc->poison, 0);
2208 INIT_WORK(&sc->reset_work, ub_reset_task, sc);
2209 init_waitqueue_head(&sc->reset_wait);
2210
2211 init_timer(&sc->work_timer);
2212 sc->work_timer.data = (unsigned long) sc;
2213 sc->work_timer.function = ub_urb_timeout;
2214
2215 ub_init_completion(&sc->work_done);
2216 sc->work_done.done = 1; /* A little yuk, but oh well... */
2217
2218 sc->dev = interface_to_usbdev(intf);
2219 sc->intf = intf;
2220 // sc->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
2221 usb_set_intfdata(intf, sc);
2222 usb_get_dev(sc->dev);
2223 /*
2224 * Since we give the interface struct to the block level through
2225 * disk->driverfs_dev, we have to pin it. Otherwise, block_uevent
2226 * oopses on close after a disconnect (kernels 2.6.16 and up).
2227 */
2228 usb_get_intf(sc->intf);
2229
2230 snprintf(sc->name, 12, DRV_NAME "(%d.%d)",
2231 sc->dev->bus->busnum, sc->dev->devnum);
2232
2233 /* XXX Verify that we can handle the device (from descriptors) */
2234
2235 if (ub_get_pipes(sc, sc->dev, intf) != 0)
2236 goto err_dev_desc;
2237
2238 /*
2239 * At this point, all USB initialization is done, do upper layer.
2240 * We really hate halfway initialized structures, so from the
2241 * invariants perspective, this ub_dev is fully constructed at
2242 * this point.
2243 */
2244
2245 /*
2246 * This is needed to clear toggles. It is a problem only if we do
2247 * `rmmod ub && modprobe ub` without disconnects, but we like that.
2248 */
2249 #if 0 /* iPod Mini fails if we do this (big white iPod works) */
2250 ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
2251 ub_probe_clear_stall(sc, sc->send_bulk_pipe);
2252 #endif
2253
2254 /*
2255 * The way this is used by the startup code is a little specific.
2256 * A SCSI check causes a USB stall. Our common case code sees it
2257 * and clears the check, after which the device is ready for use.
2258 * But if a check was not present, any command other than
2259 * TEST_UNIT_READY ends with a lockup (including REQUEST_SENSE).
2260 *
2261 * If we neglect to clear the SCSI check, the first real command fails
2262 * (which is the capacity readout). We clear that and retry, but why
2263 * causing spurious retries for no reason.
2264 *
2265 * Revalidation may start with its own TEST_UNIT_READY, but that one
2266 * has to succeed, so we clear checks with an additional one here.
2267 * In any case it's not our business how revaliadation is implemented.
2268 */
2269 for (i = 0; i < 3; i++) { /* Retries for benh's key */
2270 if ((rc = ub_sync_tur(sc, NULL)) <= 0) break;
2271 if (rc != 0x6) break;
2272 msleep(10);
2273 }
2274
2275 nluns = 1;
2276 for (i = 0; i < 3; i++) {
2277 if ((rc = ub_sync_getmaxlun(sc)) < 0)
2278 break;
2279 if (rc != 0) {
2280 nluns = rc;
2281 break;
2282 }
2283 msleep(100);
2284 }
2285
2286 for (i = 0; i < nluns; i++) {
2287 ub_probe_lun(sc, i);
2288 }
2289 return 0;
2290
2291 err_dev_desc:
2292 usb_set_intfdata(intf, NULL);
2293 usb_put_intf(sc->intf);
2294 usb_put_dev(sc->dev);
2295 kfree(sc);
2296 err_core:
2297 return rc;
2298 }
2299
2300 static int ub_probe_lun(struct ub_dev *sc, int lnum)
2301 {
2302 struct ub_lun *lun;
2303 request_queue_t *q;
2304 struct gendisk *disk;
2305 int rc;
2306
2307 rc = -ENOMEM;
2308 if ((lun = kzalloc(sizeof(struct ub_lun), GFP_KERNEL)) == NULL)
2309 goto err_alloc;
2310 lun->num = lnum;
2311
2312 rc = -ENOSR;
2313 if ((lun->id = ub_id_get()) == -1)
2314 goto err_id;
2315
2316 lun->udev = sc;
2317 list_add(&lun->link, &sc->luns);
2318
2319 snprintf(lun->name, 16, DRV_NAME "%c(%d.%d.%d)",
2320 lun->id + 'a', sc->dev->bus->busnum, sc->dev->devnum, lun->num);
2321
2322 lun->removable = 1; /* XXX Query this from the device */
2323 lun->changed = 1; /* ub_revalidate clears only */
2324 ub_revalidate(sc, lun);
2325
2326 rc = -ENOMEM;
2327 if ((disk = alloc_disk(UB_PARTS_PER_LUN)) == NULL)
2328 goto err_diskalloc;
2329
2330 lun->disk = disk;
2331 sprintf(disk->disk_name, DRV_NAME "%c", lun->id + 'a');
2332 sprintf(disk->devfs_name, DEVFS_NAME "/%c", lun->id + 'a');
2333 disk->major = UB_MAJOR;
2334 disk->first_minor = lun->id * UB_PARTS_PER_LUN;
2335 disk->fops = &ub_bd_fops;
2336 disk->private_data = lun;
2337 disk->driverfs_dev = &sc->intf->dev;
2338
2339 rc = -ENOMEM;
2340 if ((q = blk_init_queue(ub_request_fn, sc->lock)) == NULL)
2341 goto err_blkqinit;
2342
2343 disk->queue = q;
2344
2345 blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
2346 blk_queue_max_hw_segments(q, UB_MAX_REQ_SG);
2347 blk_queue_max_phys_segments(q, UB_MAX_REQ_SG);
2348 blk_queue_segment_boundary(q, 0xffffffff); /* Dubious. */
2349 blk_queue_max_sectors(q, UB_MAX_SECTORS);
2350 blk_queue_hardsect_size(q, lun->capacity.bsize);
2351
2352 q->queuedata = lun;
2353
2354 set_capacity(disk, lun->capacity.nsec);
2355 if (lun->removable)
2356 disk->flags |= GENHD_FL_REMOVABLE;
2357
2358 add_disk(disk);
2359
2360 return 0;
2361
2362 err_blkqinit:
2363 put_disk(disk);
2364 err_diskalloc:
2365 list_del(&lun->link);
2366 ub_id_put(lun->id);
2367 err_id:
2368 kfree(lun);
2369 err_alloc:
2370 return rc;
2371 }
2372
2373 static void ub_disconnect(struct usb_interface *intf)
2374 {
2375 struct ub_dev *sc = usb_get_intfdata(intf);
2376 struct list_head *p;
2377 struct ub_lun *lun;
2378 struct gendisk *disk;
2379 unsigned long flags;
2380
2381 /*
2382 * Prevent ub_bd_release from pulling the rug from under us.
2383 * XXX This is starting to look like a kref.
2384 * XXX Why not to take this ref at probe time?
2385 */
2386 spin_lock_irqsave(&ub_lock, flags);
2387 sc->openc++;
2388 spin_unlock_irqrestore(&ub_lock, flags);
2389
2390 /*
2391 * Fence stall clearnings, operations triggered by unlinkings and so on.
2392 * We do not attempt to unlink any URBs, because we do not trust the
2393 * unlink paths in HC drivers. Also, we get -84 upon disconnect anyway.
2394 */
2395 atomic_set(&sc->poison, 1);
2396
2397 /*
2398 * Wait for reset to end, if any.
2399 */
2400 wait_event(sc->reset_wait, !sc->reset);
2401
2402 /*
2403 * Blow away queued commands.
2404 *
2405 * Actually, this never works, because before we get here
2406 * the HCD terminates outstanding URB(s). It causes our
2407 * SCSI command queue to advance, commands fail to submit,
2408 * and the whole queue drains. So, we just use this code to
2409 * print warnings.
2410 */
2411 spin_lock_irqsave(sc->lock, flags);
2412 {
2413 struct ub_scsi_cmd *cmd;
2414 int cnt = 0;
2415 while ((cmd = ub_cmdq_peek(sc)) != NULL) {
2416 cmd->error = -ENOTCONN;
2417 cmd->state = UB_CMDST_DONE;
2418 ub_cmdq_pop(sc);
2419 (*cmd->done)(sc, cmd);
2420 cnt++;
2421 }
2422 if (cnt != 0) {
2423 printk(KERN_WARNING "%s: "
2424 "%d was queued after shutdown\n", sc->name, cnt);
2425 }
2426 }
2427 spin_unlock_irqrestore(sc->lock, flags);
2428
2429 /*
2430 * Unregister the upper layer.
2431 */
2432 list_for_each (p, &sc->luns) {
2433 lun = list_entry(p, struct ub_lun, link);
2434 disk = lun->disk;
2435 if (disk->flags & GENHD_FL_UP)
2436 del_gendisk(disk);
2437 /*
2438 * I wish I could do:
2439 * set_bit(QUEUE_FLAG_DEAD, &q->queue_flags);
2440 * As it is, we rely on our internal poisoning and let
2441 * the upper levels to spin furiously failing all the I/O.
2442 */
2443 }
2444
2445 /*
2446 * Testing for -EINPROGRESS is always a bug, so we are bending
2447 * the rules a little.
2448 */
2449 spin_lock_irqsave(sc->lock, flags);
2450 if (sc->work_urb.status == -EINPROGRESS) { /* janitors: ignore */
2451 printk(KERN_WARNING "%s: "
2452 "URB is active after disconnect\n", sc->name);
2453 }
2454 spin_unlock_irqrestore(sc->lock, flags);
2455
2456 /*
2457 * There is virtually no chance that other CPU runs times so long
2458 * after ub_urb_complete should have called del_timer, but only if HCD
2459 * didn't forget to deliver a callback on unlink.
2460 */
2461 del_timer_sync(&sc->work_timer);
2462
2463 /*
2464 * At this point there must be no commands coming from anyone
2465 * and no URBs left in transit.
2466 */
2467
2468 ub_put(sc);
2469 }
2470
2471 static struct usb_driver ub_driver = {
2472 .name = "ub",
2473 .probe = ub_probe,
2474 .disconnect = ub_disconnect,
2475 .id_table = ub_usb_ids,
2476 };
2477
2478 static int __init ub_init(void)
2479 {
2480 int rc;
2481 int i;
2482
2483 for (i = 0; i < UB_QLOCK_NUM; i++)
2484 spin_lock_init(&ub_qlockv[i]);
2485
2486 if ((rc = register_blkdev(UB_MAJOR, DRV_NAME)) != 0)
2487 goto err_regblkdev;
2488 devfs_mk_dir(DEVFS_NAME);
2489
2490 if ((rc = usb_register(&ub_driver)) != 0)
2491 goto err_register;
2492
2493 usb_usual_set_present(USB_US_TYPE_UB);
2494 return 0;
2495
2496 err_register:
2497 devfs_remove(DEVFS_NAME);
2498 unregister_blkdev(UB_MAJOR, DRV_NAME);
2499 err_regblkdev:
2500 return rc;
2501 }
2502
2503 static void __exit ub_exit(void)
2504 {
2505 usb_deregister(&ub_driver);
2506
2507 devfs_remove(DEVFS_NAME);
2508 unregister_blkdev(UB_MAJOR, DRV_NAME);
2509 usb_usual_clear_present(USB_US_TYPE_UB);
2510 }
2511
2512 module_init(ub_init);
2513 module_exit(ub_exit);
2514
2515 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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