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[PATCH] USB: drivers/usb/storage/libusual
[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 * -- Kill first_open (Al Viro fixed the block layer now)
12 * -- Do resets with usb_device_reset (needs a thread context, use khubd)
13 * -- set readonly flag for CDs, set removable flag for CF readers
14 * -- do inquiry and verify we got a disk and not a tape (for LUN mismatch)
15 * -- special case some senses, e.g. 3a/0 -> no media present, reduce retries
16 * -- verify the 13 conditions and do bulk resets
17 * -- kill last_pipe and simply do two-state clearing on both pipes
18 * -- verify protocol (bulk) from USB descriptors (maybe...)
19 * -- highmem
20 * -- move top_sense and work_bcs into separate allocations (if they survive)
21 * for cache purists and esoteric architectures.
22 * -- Allocate structure for LUN 0 before the first ub_sync_tur, avoid NULL. ?
23 * -- prune comments, they are too volumnous
24 * -- Exterminate P3 printks
25 * -- Resove XXX's
26 * -- Redo "benh's retries", perhaps have spin-up code to handle them. V:D=?
27 * -- CLEAR, CLR2STS, CLRRS seem to be ripe for refactoring.
28 */
29 #include <linux/kernel.h>
30 #include <linux/module.h>
31 #include <linux/usb.h>
32 #include <linux/usb_usual.h>
33 #include <linux/blkdev.h>
34 #include <linux/devfs_fs_kernel.h>
35 #include <linux/timer.h>
36 #include <scsi/scsi.h>
37
38 #define DRV_NAME "ub"
39 #define DEVFS_NAME DRV_NAME
40
41 #define UB_MAJOR 180
42
43 /*
44 * The command state machine is the key model for understanding of this driver.
45 *
46 * The general rule is that all transitions are done towards the bottom
47 * of the diagram, thus preventing any loops.
48 *
49 * An exception to that is how the STAT state is handled. A counter allows it
50 * to be re-entered along the path marked with [C].
51 *
52 * +--------+
53 * ! INIT !
54 * +--------+
55 * !
56 * ub_scsi_cmd_start fails ->--------------------------------------\
57 * ! !
58 * V !
59 * +--------+ !
60 * ! CMD ! !
61 * +--------+ !
62 * ! +--------+ !
63 * was -EPIPE -->-------------------------------->! CLEAR ! !
64 * ! +--------+ !
65 * ! ! !
66 * was error -->------------------------------------- ! --------->\
67 * ! ! !
68 * /--<-- cmd->dir == NONE ? ! !
69 * ! ! ! !
70 * ! V ! !
71 * ! +--------+ ! !
72 * ! ! DATA ! ! !
73 * ! +--------+ ! !
74 * ! ! +---------+ ! !
75 * ! was -EPIPE -->--------------->! CLR2STS ! ! !
76 * ! ! +---------+ ! !
77 * ! ! ! ! !
78 * ! ! was error -->---- ! --------->\
79 * ! was error -->--------------------- ! ------------- ! --------->\
80 * ! ! ! ! !
81 * ! V ! ! !
82 * \--->+--------+ ! ! !
83 * ! STAT !<--------------------------/ ! !
84 * /--->+--------+ ! !
85 * ! ! ! !
86 * [C] was -EPIPE -->-----------\ ! !
87 * ! ! ! ! !
88 * +<---- len == 0 ! ! !
89 * ! ! ! ! !
90 * ! was error -->--------------------------------------!---------->\
91 * ! ! ! ! !
92 * +<---- bad CSW ! ! !
93 * +<---- bad tag ! ! !
94 * ! ! V ! !
95 * ! ! +--------+ ! !
96 * ! ! ! CLRRS ! ! !
97 * ! ! +--------+ ! !
98 * ! ! ! ! !
99 * \------- ! --------------------[C]--------\ ! !
100 * ! ! ! !
101 * cmd->error---\ +--------+ ! !
102 * ! +--------------->! SENSE !<----------/ !
103 * STAT_FAIL----/ +--------+ !
104 * ! ! V
105 * ! V +--------+
106 * \--------------------------------\--------------------->! DONE !
107 * +--------+
108 */
109
110 /*
111 * This many LUNs per USB device.
112 * Every one of them takes a host, see UB_MAX_HOSTS.
113 */
114 #define UB_MAX_LUNS 9
115
116 /*
117 */
118
119 #define UB_MINORS_PER_MAJOR 8
120
121 #define UB_MAX_CDB_SIZE 16 /* Corresponds to Bulk */
122
123 #define UB_SENSE_SIZE 18
124
125 /*
126 */
127
128 /* command block wrapper */
129 struct bulk_cb_wrap {
130 __le32 Signature; /* contains 'USBC' */
131 u32 Tag; /* unique per command id */
132 __le32 DataTransferLength; /* size of data */
133 u8 Flags; /* direction in bit 0 */
134 u8 Lun; /* LUN */
135 u8 Length; /* of of the CDB */
136 u8 CDB[UB_MAX_CDB_SIZE]; /* max command */
137 };
138
139 #define US_BULK_CB_WRAP_LEN 31
140 #define US_BULK_CB_SIGN 0x43425355 /*spells out USBC */
141 #define US_BULK_FLAG_IN 1
142 #define US_BULK_FLAG_OUT 0
143
144 /* command status wrapper */
145 struct bulk_cs_wrap {
146 __le32 Signature; /* should = 'USBS' */
147 u32 Tag; /* same as original command */
148 __le32 Residue; /* amount not transferred */
149 u8 Status; /* see below */
150 };
151
152 #define US_BULK_CS_WRAP_LEN 13
153 #define US_BULK_CS_SIGN 0x53425355 /* spells out 'USBS' */
154 #define US_BULK_STAT_OK 0
155 #define US_BULK_STAT_FAIL 1
156 #define US_BULK_STAT_PHASE 2
157
158 /* bulk-only class specific requests */
159 #define US_BULK_RESET_REQUEST 0xff
160 #define US_BULK_GET_MAX_LUN 0xfe
161
162 /*
163 */
164 struct ub_dev;
165
166 #define UB_MAX_REQ_SG 9 /* cdrecord requires 32KB and maybe a header */
167 #define UB_MAX_SECTORS 64
168
169 /*
170 * A second is more than enough for a 32K transfer (UB_MAX_SECTORS)
171 * even if a webcam hogs the bus, but some devices need time to spin up.
172 */
173 #define UB_URB_TIMEOUT (HZ*2)
174 #define UB_DATA_TIMEOUT (HZ*5) /* ZIP does spin-ups in the data phase */
175 #define UB_STAT_TIMEOUT (HZ*5) /* Same spinups and eject for a dataless cmd. */
176 #define UB_CTRL_TIMEOUT (HZ/2) /* 500ms ought to be enough to clear a stall */
177
178 /*
179 * An instance of a SCSI command in transit.
180 */
181 #define UB_DIR_NONE 0
182 #define UB_DIR_READ 1
183 #define UB_DIR_ILLEGAL2 2
184 #define UB_DIR_WRITE 3
185
186 #define UB_DIR_CHAR(c) (((c)==UB_DIR_WRITE)? 'w': \
187 (((c)==UB_DIR_READ)? 'r': 'n'))
188
189 enum ub_scsi_cmd_state {
190 UB_CMDST_INIT, /* Initial state */
191 UB_CMDST_CMD, /* Command submitted */
192 UB_CMDST_DATA, /* Data phase */
193 UB_CMDST_CLR2STS, /* Clearing before requesting status */
194 UB_CMDST_STAT, /* Status phase */
195 UB_CMDST_CLEAR, /* Clearing a stall (halt, actually) */
196 UB_CMDST_CLRRS, /* Clearing before retrying status */
197 UB_CMDST_SENSE, /* Sending Request Sense */
198 UB_CMDST_DONE /* Final state */
199 };
200
201 static char *ub_scsi_cmd_stname[] = {
202 ". ",
203 "Cmd",
204 "dat",
205 "c2s",
206 "sts",
207 "clr",
208 "crs",
209 "Sen",
210 "fin"
211 };
212
213 struct ub_scsi_cmd {
214 unsigned char cdb[UB_MAX_CDB_SIZE];
215 unsigned char cdb_len;
216
217 unsigned char dir; /* 0 - none, 1 - read, 3 - write. */
218 unsigned char trace_index;
219 enum ub_scsi_cmd_state state;
220 unsigned int tag;
221 struct ub_scsi_cmd *next;
222
223 int error; /* Return code - valid upon done */
224 unsigned int act_len; /* Return size */
225 unsigned char key, asc, ascq; /* May be valid if error==-EIO */
226
227 int stat_count; /* Retries getting status. */
228
229 unsigned int len; /* Requested length */
230 unsigned int current_sg;
231 unsigned int nsg; /* sgv[nsg] */
232 struct scatterlist sgv[UB_MAX_REQ_SG];
233
234 struct ub_lun *lun;
235 void (*done)(struct ub_dev *, struct ub_scsi_cmd *);
236 void *back;
237 };
238
239 /*
240 */
241 struct ub_capacity {
242 unsigned long nsec; /* Linux size - 512 byte sectors */
243 unsigned int bsize; /* Linux hardsect_size */
244 unsigned int bshift; /* Shift between 512 and hard sects */
245 };
246
247 /*
248 * The SCSI command tracing structure.
249 */
250
251 #define SCMD_ST_HIST_SZ 8
252 #define SCMD_TRACE_SZ 63 /* Less than 4KB of 61-byte lines */
253
254 struct ub_scsi_cmd_trace {
255 int hcur;
256 unsigned int tag;
257 unsigned int req_size, act_size;
258 unsigned char op;
259 unsigned char dir;
260 unsigned char key, asc, ascq;
261 char st_hst[SCMD_ST_HIST_SZ];
262 };
263
264 struct ub_scsi_trace {
265 int cur;
266 struct ub_scsi_cmd_trace vec[SCMD_TRACE_SZ];
267 };
268
269 /*
270 * This is a direct take-off from linux/include/completion.h
271 * The difference is that I do not wait on this thing, just poll.
272 * When I want to wait (ub_probe), I just use the stock completion.
273 *
274 * Note that INIT_COMPLETION takes no lock. It is correct. But why
275 * in the bloody hell that thing takes struct instead of pointer to struct
276 * is quite beyond me. I just copied it from the stock completion.
277 */
278 struct ub_completion {
279 unsigned int done;
280 spinlock_t lock;
281 };
282
283 static inline void ub_init_completion(struct ub_completion *x)
284 {
285 x->done = 0;
286 spin_lock_init(&x->lock);
287 }
288
289 #define UB_INIT_COMPLETION(x) ((x).done = 0)
290
291 static void ub_complete(struct ub_completion *x)
292 {
293 unsigned long flags;
294
295 spin_lock_irqsave(&x->lock, flags);
296 x->done++;
297 spin_unlock_irqrestore(&x->lock, flags);
298 }
299
300 static int ub_is_completed(struct ub_completion *x)
301 {
302 unsigned long flags;
303 int ret;
304
305 spin_lock_irqsave(&x->lock, flags);
306 ret = x->done;
307 spin_unlock_irqrestore(&x->lock, flags);
308 return ret;
309 }
310
311 /*
312 */
313 struct ub_scsi_cmd_queue {
314 int qlen, qmax;
315 struct ub_scsi_cmd *head, *tail;
316 };
317
318 /*
319 * The block device instance (one per LUN).
320 */
321 struct ub_lun {
322 struct ub_dev *udev;
323 struct list_head link;
324 struct gendisk *disk;
325 int id; /* Host index */
326 int num; /* LUN number */
327 char name[16];
328
329 int changed; /* Media was changed */
330 int removable;
331 int readonly;
332 int first_open; /* Kludge. See ub_bd_open. */
333
334 /* Use Ingo's mempool if or when we have more than one command. */
335 /*
336 * Currently we never need more than one command for the whole device.
337 * However, giving every LUN a command is a cheap and automatic way
338 * to enforce fairness between them.
339 */
340 int cmda[1];
341 struct ub_scsi_cmd cmdv[1];
342
343 struct ub_capacity capacity;
344 };
345
346 /*
347 * The USB device instance.
348 */
349 struct ub_dev {
350 spinlock_t lock;
351 atomic_t poison; /* The USB device is disconnected */
352 int openc; /* protected by ub_lock! */
353 /* kref is too implicit for our taste */
354 unsigned int tagcnt;
355 char name[12];
356 struct usb_device *dev;
357 struct usb_interface *intf;
358
359 struct list_head luns;
360
361 unsigned int send_bulk_pipe; /* cached pipe values */
362 unsigned int recv_bulk_pipe;
363 unsigned int send_ctrl_pipe;
364 unsigned int recv_ctrl_pipe;
365
366 struct tasklet_struct tasklet;
367
368 struct ub_scsi_cmd_queue cmd_queue;
369 struct ub_scsi_cmd top_rqs_cmd; /* REQUEST SENSE */
370 unsigned char top_sense[UB_SENSE_SIZE];
371
372 struct ub_completion work_done;
373 struct urb work_urb;
374 struct timer_list work_timer;
375 int last_pipe; /* What might need clearing */
376 __le32 signature; /* Learned signature */
377 struct bulk_cb_wrap work_bcb;
378 struct bulk_cs_wrap work_bcs;
379 struct usb_ctrlrequest work_cr;
380
381 int sg_stat[6];
382 struct ub_scsi_trace tr;
383 };
384
385 /*
386 */
387 static void ub_cleanup(struct ub_dev *sc);
388 static int ub_request_fn_1(struct ub_lun *lun, struct request *rq);
389 static int ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
390 struct ub_scsi_cmd *cmd, struct request *rq);
391 static int ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
392 struct ub_scsi_cmd *cmd, struct request *rq);
393 static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
394 static void ub_end_rq(struct request *rq, int uptodate);
395 static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
396 static void ub_urb_complete(struct urb *urb, struct pt_regs *pt);
397 static void ub_scsi_action(unsigned long _dev);
398 static void ub_scsi_dispatch(struct ub_dev *sc);
399 static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
400 static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
401 static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc);
402 static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
403 static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
404 static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
405 static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
406 static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
407 int stalled_pipe);
408 static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd);
409 static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun);
410 static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
411 struct ub_capacity *ret);
412 static int ub_probe_lun(struct ub_dev *sc, int lnum);
413
414 /*
415 */
416 #ifdef CONFIG_USB_LIBUSUAL
417
418 #define ub_usb_ids storage_usb_ids
419 #else
420
421 static struct usb_device_id ub_usb_ids[] = {
422 { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, US_SC_SCSI, US_PR_BULK) },
423 { }
424 };
425
426 MODULE_DEVICE_TABLE(usb, ub_usb_ids);
427 #endif /* CONFIG_USB_LIBUSUAL */
428
429 /*
430 * Find me a way to identify "next free minor" for add_disk(),
431 * and the array disappears the next day. However, the number of
432 * hosts has something to do with the naming and /proc/partitions.
433 * This has to be thought out in detail before changing.
434 * If UB_MAX_HOST was 1000, we'd use a bitmap. Or a better data structure.
435 */
436 #define UB_MAX_HOSTS 26
437 static char ub_hostv[UB_MAX_HOSTS];
438
439 static DEFINE_SPINLOCK(ub_lock); /* Locks globals and ->openc */
440
441 /*
442 * The SCSI command tracing procedures.
443 */
444
445 static void ub_cmdtr_new(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
446 {
447 int n;
448 struct ub_scsi_cmd_trace *t;
449
450 if ((n = sc->tr.cur + 1) == SCMD_TRACE_SZ) n = 0;
451 t = &sc->tr.vec[n];
452
453 memset(t, 0, sizeof(struct ub_scsi_cmd_trace));
454 t->tag = cmd->tag;
455 t->op = cmd->cdb[0];
456 t->dir = cmd->dir;
457 t->req_size = cmd->len;
458 t->st_hst[0] = cmd->state;
459
460 sc->tr.cur = n;
461 cmd->trace_index = n;
462 }
463
464 static void ub_cmdtr_state(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
465 {
466 int n;
467 struct ub_scsi_cmd_trace *t;
468
469 t = &sc->tr.vec[cmd->trace_index];
470 if (t->tag == cmd->tag) {
471 if ((n = t->hcur + 1) == SCMD_ST_HIST_SZ) n = 0;
472 t->st_hst[n] = cmd->state;
473 t->hcur = n;
474 }
475 }
476
477 static void ub_cmdtr_act_len(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
478 {
479 struct ub_scsi_cmd_trace *t;
480
481 t = &sc->tr.vec[cmd->trace_index];
482 if (t->tag == cmd->tag)
483 t->act_size = cmd->act_len;
484 }
485
486 static void ub_cmdtr_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
487 unsigned char *sense)
488 {
489 struct ub_scsi_cmd_trace *t;
490
491 t = &sc->tr.vec[cmd->trace_index];
492 if (t->tag == cmd->tag) {
493 t->key = sense[2] & 0x0F;
494 t->asc = sense[12];
495 t->ascq = sense[13];
496 }
497 }
498
499 static ssize_t ub_diag_show(struct device *dev, struct device_attribute *attr,
500 char *page)
501 {
502 struct usb_interface *intf;
503 struct ub_dev *sc;
504 struct list_head *p;
505 struct ub_lun *lun;
506 int cnt;
507 unsigned long flags;
508 int nc, nh;
509 int i, j;
510 struct ub_scsi_cmd_trace *t;
511
512 intf = to_usb_interface(dev);
513 sc = usb_get_intfdata(intf);
514 if (sc == NULL)
515 return 0;
516
517 cnt = 0;
518 spin_lock_irqsave(&sc->lock, flags);
519
520 cnt += sprintf(page + cnt,
521 "qlen %d qmax %d\n",
522 sc->cmd_queue.qlen, sc->cmd_queue.qmax);
523 cnt += sprintf(page + cnt,
524 "sg %d %d %d %d %d .. %d\n",
525 sc->sg_stat[0],
526 sc->sg_stat[1],
527 sc->sg_stat[2],
528 sc->sg_stat[3],
529 sc->sg_stat[4],
530 sc->sg_stat[5]);
531
532 list_for_each (p, &sc->luns) {
533 lun = list_entry(p, struct ub_lun, link);
534 cnt += sprintf(page + cnt,
535 "lun %u changed %d removable %d readonly %d\n",
536 lun->num, lun->changed, lun->removable, lun->readonly);
537 }
538
539 if ((nc = sc->tr.cur + 1) == SCMD_TRACE_SZ) nc = 0;
540 for (j = 0; j < SCMD_TRACE_SZ; j++) {
541 t = &sc->tr.vec[nc];
542
543 cnt += sprintf(page + cnt, "%08x %02x", t->tag, t->op);
544 if (t->op == REQUEST_SENSE) {
545 cnt += sprintf(page + cnt, " [sense %x %02x %02x]",
546 t->key, t->asc, t->ascq);
547 } else {
548 cnt += sprintf(page + cnt, " %c", UB_DIR_CHAR(t->dir));
549 cnt += sprintf(page + cnt, " [%5d %5d]",
550 t->req_size, t->act_size);
551 }
552 if ((nh = t->hcur + 1) == SCMD_ST_HIST_SZ) nh = 0;
553 for (i = 0; i < SCMD_ST_HIST_SZ; i++) {
554 cnt += sprintf(page + cnt, " %s",
555 ub_scsi_cmd_stname[(int)t->st_hst[nh]]);
556 if (++nh == SCMD_ST_HIST_SZ) nh = 0;
557 }
558 cnt += sprintf(page + cnt, "\n");
559
560 if (++nc == SCMD_TRACE_SZ) nc = 0;
561 }
562
563 spin_unlock_irqrestore(&sc->lock, flags);
564 return cnt;
565 }
566
567 static DEVICE_ATTR(diag, S_IRUGO, ub_diag_show, NULL); /* N.B. World readable */
568
569 /*
570 * The id allocator.
571 *
572 * This also stores the host for indexing by minor, which is somewhat dirty.
573 */
574 static int ub_id_get(void)
575 {
576 unsigned long flags;
577 int i;
578
579 spin_lock_irqsave(&ub_lock, flags);
580 for (i = 0; i < UB_MAX_HOSTS; i++) {
581 if (ub_hostv[i] == 0) {
582 ub_hostv[i] = 1;
583 spin_unlock_irqrestore(&ub_lock, flags);
584 return i;
585 }
586 }
587 spin_unlock_irqrestore(&ub_lock, flags);
588 return -1;
589 }
590
591 static void ub_id_put(int id)
592 {
593 unsigned long flags;
594
595 if (id < 0 || id >= UB_MAX_HOSTS) {
596 printk(KERN_ERR DRV_NAME ": bad host ID %d\n", id);
597 return;
598 }
599
600 spin_lock_irqsave(&ub_lock, flags);
601 if (ub_hostv[id] == 0) {
602 spin_unlock_irqrestore(&ub_lock, flags);
603 printk(KERN_ERR DRV_NAME ": freeing free host ID %d\n", id);
604 return;
605 }
606 ub_hostv[id] = 0;
607 spin_unlock_irqrestore(&ub_lock, flags);
608 }
609
610 /*
611 * Downcount for deallocation. This rides on two assumptions:
612 * - once something is poisoned, its refcount cannot grow
613 * - opens cannot happen at this time (del_gendisk was done)
614 * If the above is true, we can drop the lock, which we need for
615 * blk_cleanup_queue(): the silly thing may attempt to sleep.
616 * [Actually, it never needs to sleep for us, but it calls might_sleep()]
617 */
618 static void ub_put(struct ub_dev *sc)
619 {
620 unsigned long flags;
621
622 spin_lock_irqsave(&ub_lock, flags);
623 --sc->openc;
624 if (sc->openc == 0 && atomic_read(&sc->poison)) {
625 spin_unlock_irqrestore(&ub_lock, flags);
626 ub_cleanup(sc);
627 } else {
628 spin_unlock_irqrestore(&ub_lock, flags);
629 }
630 }
631
632 /*
633 * Final cleanup and deallocation.
634 */
635 static void ub_cleanup(struct ub_dev *sc)
636 {
637 struct list_head *p;
638 struct ub_lun *lun;
639 request_queue_t *q;
640
641 while (!list_empty(&sc->luns)) {
642 p = sc->luns.next;
643 lun = list_entry(p, struct ub_lun, link);
644 list_del(p);
645
646 /* I don't think queue can be NULL. But... Stolen from sx8.c */
647 if ((q = lun->disk->queue) != NULL)
648 blk_cleanup_queue(q);
649 /*
650 * If we zero disk->private_data BEFORE put_disk, we have
651 * to check for NULL all over the place in open, release,
652 * check_media and revalidate, because the block level
653 * semaphore is well inside the put_disk.
654 * But we cannot zero after the call, because *disk is gone.
655 * The sd.c is blatantly racy in this area.
656 */
657 /* disk->private_data = NULL; */
658 put_disk(lun->disk);
659 lun->disk = NULL;
660
661 ub_id_put(lun->id);
662 kfree(lun);
663 }
664
665 kfree(sc);
666 }
667
668 /*
669 * The "command allocator".
670 */
671 static struct ub_scsi_cmd *ub_get_cmd(struct ub_lun *lun)
672 {
673 struct ub_scsi_cmd *ret;
674
675 if (lun->cmda[0])
676 return NULL;
677 ret = &lun->cmdv[0];
678 lun->cmda[0] = 1;
679 return ret;
680 }
681
682 static void ub_put_cmd(struct ub_lun *lun, struct ub_scsi_cmd *cmd)
683 {
684 if (cmd != &lun->cmdv[0]) {
685 printk(KERN_WARNING "%s: releasing a foreign cmd %p\n",
686 lun->name, cmd);
687 return;
688 }
689 if (!lun->cmda[0]) {
690 printk(KERN_WARNING "%s: releasing a free cmd\n", lun->name);
691 return;
692 }
693 lun->cmda[0] = 0;
694 }
695
696 /*
697 * The command queue.
698 */
699 static void ub_cmdq_add(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
700 {
701 struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
702
703 if (t->qlen++ == 0) {
704 t->head = cmd;
705 t->tail = cmd;
706 } else {
707 t->tail->next = cmd;
708 t->tail = cmd;
709 }
710
711 if (t->qlen > t->qmax)
712 t->qmax = t->qlen;
713 }
714
715 static void ub_cmdq_insert(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
716 {
717 struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
718
719 if (t->qlen++ == 0) {
720 t->head = cmd;
721 t->tail = cmd;
722 } else {
723 cmd->next = t->head;
724 t->head = cmd;
725 }
726
727 if (t->qlen > t->qmax)
728 t->qmax = t->qlen;
729 }
730
731 static struct ub_scsi_cmd *ub_cmdq_pop(struct ub_dev *sc)
732 {
733 struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
734 struct ub_scsi_cmd *cmd;
735
736 if (t->qlen == 0)
737 return NULL;
738 if (--t->qlen == 0)
739 t->tail = NULL;
740 cmd = t->head;
741 t->head = cmd->next;
742 cmd->next = NULL;
743 return cmd;
744 }
745
746 #define ub_cmdq_peek(sc) ((sc)->cmd_queue.head)
747
748 /*
749 * The request function is our main entry point
750 */
751
752 static void ub_request_fn(request_queue_t *q)
753 {
754 struct ub_lun *lun = q->queuedata;
755 struct request *rq;
756
757 while ((rq = elv_next_request(q)) != NULL) {
758 if (ub_request_fn_1(lun, rq) != 0) {
759 blk_stop_queue(q);
760 break;
761 }
762 }
763 }
764
765 static int ub_request_fn_1(struct ub_lun *lun, struct request *rq)
766 {
767 struct ub_dev *sc = lun->udev;
768 struct ub_scsi_cmd *cmd;
769 int rc;
770
771 if (atomic_read(&sc->poison) || lun->changed) {
772 blkdev_dequeue_request(rq);
773 ub_end_rq(rq, 0);
774 return 0;
775 }
776
777 if ((cmd = ub_get_cmd(lun)) == NULL)
778 return -1;
779 memset(cmd, 0, sizeof(struct ub_scsi_cmd));
780
781 blkdev_dequeue_request(rq);
782 if (blk_pc_request(rq)) {
783 rc = ub_cmd_build_packet(sc, lun, cmd, rq);
784 } else {
785 rc = ub_cmd_build_block(sc, lun, cmd, rq);
786 }
787 if (rc != 0) {
788 ub_put_cmd(lun, cmd);
789 ub_end_rq(rq, 0);
790 return 0;
791 }
792 cmd->state = UB_CMDST_INIT;
793 cmd->lun = lun;
794 cmd->done = ub_rw_cmd_done;
795 cmd->back = rq;
796
797 cmd->tag = sc->tagcnt++;
798 if (ub_submit_scsi(sc, cmd) != 0) {
799 ub_put_cmd(lun, cmd);
800 ub_end_rq(rq, 0);
801 return 0;
802 }
803
804 return 0;
805 }
806
807 static int ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
808 struct ub_scsi_cmd *cmd, struct request *rq)
809 {
810 int ub_dir;
811 int n_elem;
812 unsigned int block, nblks;
813
814 if (rq_data_dir(rq) == WRITE)
815 ub_dir = UB_DIR_WRITE;
816 else
817 ub_dir = UB_DIR_READ;
818 cmd->dir = ub_dir;
819
820 /*
821 * get scatterlist from block layer
822 */
823 n_elem = blk_rq_map_sg(lun->disk->queue, rq, &cmd->sgv[0]);
824 if (n_elem <= 0) {
825 printk(KERN_INFO "%s: failed request map (%d)\n",
826 sc->name, n_elem); /* P3 */
827 return -1; /* request with no s/g entries? */
828 }
829 if (n_elem > UB_MAX_REQ_SG) { /* Paranoia */
830 printk(KERN_WARNING "%s: request with %d segments\n",
831 sc->name, n_elem);
832 return -1;
833 }
834 cmd->nsg = n_elem;
835 sc->sg_stat[n_elem < 5 ? n_elem : 5]++;
836
837 /*
838 * build the command
839 *
840 * The call to blk_queue_hardsect_size() guarantees that request
841 * is aligned, but it is given in terms of 512 byte units, always.
842 */
843 block = rq->sector >> lun->capacity.bshift;
844 nblks = rq->nr_sectors >> lun->capacity.bshift;
845
846 cmd->cdb[0] = (ub_dir == UB_DIR_READ)? READ_10: WRITE_10;
847 /* 10-byte uses 4 bytes of LBA: 2147483648KB, 2097152MB, 2048GB */
848 cmd->cdb[2] = block >> 24;
849 cmd->cdb[3] = block >> 16;
850 cmd->cdb[4] = block >> 8;
851 cmd->cdb[5] = block;
852 cmd->cdb[7] = nblks >> 8;
853 cmd->cdb[8] = nblks;
854 cmd->cdb_len = 10;
855
856 cmd->len = rq->nr_sectors * 512;
857
858 return 0;
859 }
860
861 static int ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
862 struct ub_scsi_cmd *cmd, struct request *rq)
863 {
864 int n_elem;
865
866 if (rq->data_len == 0) {
867 cmd->dir = UB_DIR_NONE;
868 } else {
869 if (rq_data_dir(rq) == WRITE)
870 cmd->dir = UB_DIR_WRITE;
871 else
872 cmd->dir = UB_DIR_READ;
873
874 }
875
876 /*
877 * get scatterlist from block layer
878 */
879 n_elem = blk_rq_map_sg(lun->disk->queue, rq, &cmd->sgv[0]);
880 if (n_elem < 0) {
881 printk(KERN_INFO "%s: failed request map (%d)\n",
882 sc->name, n_elem); /* P3 */
883 return -1;
884 }
885 if (n_elem > UB_MAX_REQ_SG) { /* Paranoia */
886 printk(KERN_WARNING "%s: request with %d segments\n",
887 sc->name, n_elem);
888 return -1;
889 }
890 cmd->nsg = n_elem;
891 sc->sg_stat[n_elem < 5 ? n_elem : 5]++;
892
893 memcpy(&cmd->cdb, rq->cmd, rq->cmd_len);
894 cmd->cdb_len = rq->cmd_len;
895
896 cmd->len = rq->data_len;
897
898 return 0;
899 }
900
901 static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
902 {
903 struct request *rq = cmd->back;
904 struct ub_lun *lun = cmd->lun;
905 int uptodate;
906
907 if (cmd->error == 0) {
908 uptodate = 1;
909
910 if (blk_pc_request(rq)) {
911 if (cmd->act_len >= rq->data_len)
912 rq->data_len = 0;
913 else
914 rq->data_len -= cmd->act_len;
915 }
916 } else {
917 uptodate = 0;
918
919 if (blk_pc_request(rq)) {
920 /* UB_SENSE_SIZE is smaller than SCSI_SENSE_BUFFERSIZE */
921 memcpy(rq->sense, sc->top_sense, UB_SENSE_SIZE);
922 rq->sense_len = UB_SENSE_SIZE;
923 if (sc->top_sense[0] != 0)
924 rq->errors = SAM_STAT_CHECK_CONDITION;
925 else
926 rq->errors = DID_ERROR << 16;
927 }
928 }
929
930 ub_put_cmd(lun, cmd);
931 ub_end_rq(rq, uptodate);
932 blk_start_queue(lun->disk->queue);
933 }
934
935 static void ub_end_rq(struct request *rq, int uptodate)
936 {
937 int rc;
938
939 rc = end_that_request_first(rq, uptodate, rq->hard_nr_sectors);
940 // assert(rc == 0);
941 end_that_request_last(rq);
942 }
943
944 /*
945 * Submit a regular SCSI operation (not an auto-sense).
946 *
947 * The Iron Law of Good Submit Routine is:
948 * Zero return - callback is done, Nonzero return - callback is not done.
949 * No exceptions.
950 *
951 * Host is assumed locked.
952 *
953 * XXX We only support Bulk for the moment.
954 */
955 static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
956 {
957
958 if (cmd->state != UB_CMDST_INIT ||
959 (cmd->dir != UB_DIR_NONE && cmd->len == 0)) {
960 return -EINVAL;
961 }
962
963 ub_cmdq_add(sc, cmd);
964 /*
965 * We can call ub_scsi_dispatch(sc) right away here, but it's a little
966 * safer to jump to a tasklet, in case upper layers do something silly.
967 */
968 tasklet_schedule(&sc->tasklet);
969 return 0;
970 }
971
972 /*
973 * Submit the first URB for the queued command.
974 * This function does not deal with queueing in any way.
975 */
976 static int ub_scsi_cmd_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
977 {
978 struct bulk_cb_wrap *bcb;
979 int rc;
980
981 bcb = &sc->work_bcb;
982
983 /*
984 * ``If the allocation length is eighteen or greater, and a device
985 * server returns less than eithteen bytes of data, the application
986 * client should assume that the bytes not transferred would have been
987 * zeroes had the device server returned those bytes.''
988 *
989 * We zero sense for all commands so that when a packet request
990 * fails it does not return a stale sense.
991 */
992 memset(&sc->top_sense, 0, UB_SENSE_SIZE);
993
994 /* set up the command wrapper */
995 bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
996 bcb->Tag = cmd->tag; /* Endianness is not important */
997 bcb->DataTransferLength = cpu_to_le32(cmd->len);
998 bcb->Flags = (cmd->dir == UB_DIR_READ) ? 0x80 : 0;
999 bcb->Lun = (cmd->lun != NULL) ? cmd->lun->num : 0;
1000 bcb->Length = cmd->cdb_len;
1001
1002 /* copy the command payload */
1003 memcpy(bcb->CDB, cmd->cdb, UB_MAX_CDB_SIZE);
1004
1005 UB_INIT_COMPLETION(sc->work_done);
1006
1007 sc->last_pipe = sc->send_bulk_pipe;
1008 usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->send_bulk_pipe,
1009 bcb, US_BULK_CB_WRAP_LEN, ub_urb_complete, sc);
1010
1011 /* Fill what we shouldn't be filling, because usb-storage did so. */
1012 sc->work_urb.actual_length = 0;
1013 sc->work_urb.error_count = 0;
1014 sc->work_urb.status = 0;
1015
1016 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1017 /* XXX Clear stalls */
1018 ub_complete(&sc->work_done);
1019 return rc;
1020 }
1021
1022 sc->work_timer.expires = jiffies + UB_URB_TIMEOUT;
1023 add_timer(&sc->work_timer);
1024
1025 cmd->state = UB_CMDST_CMD;
1026 ub_cmdtr_state(sc, cmd);
1027 return 0;
1028 }
1029
1030 /*
1031 * Timeout handler.
1032 */
1033 static void ub_urb_timeout(unsigned long arg)
1034 {
1035 struct ub_dev *sc = (struct ub_dev *) arg;
1036 unsigned long flags;
1037
1038 spin_lock_irqsave(&sc->lock, flags);
1039 usb_unlink_urb(&sc->work_urb);
1040 spin_unlock_irqrestore(&sc->lock, flags);
1041 }
1042
1043 /*
1044 * Completion routine for the work URB.
1045 *
1046 * This can be called directly from usb_submit_urb (while we have
1047 * the sc->lock taken) and from an interrupt (while we do NOT have
1048 * the sc->lock taken). Therefore, bounce this off to a tasklet.
1049 */
1050 static void ub_urb_complete(struct urb *urb, struct pt_regs *pt)
1051 {
1052 struct ub_dev *sc = urb->context;
1053
1054 ub_complete(&sc->work_done);
1055 tasklet_schedule(&sc->tasklet);
1056 }
1057
1058 static void ub_scsi_action(unsigned long _dev)
1059 {
1060 struct ub_dev *sc = (struct ub_dev *) _dev;
1061 unsigned long flags;
1062
1063 spin_lock_irqsave(&sc->lock, flags);
1064 del_timer(&sc->work_timer);
1065 ub_scsi_dispatch(sc);
1066 spin_unlock_irqrestore(&sc->lock, flags);
1067 }
1068
1069 static void ub_scsi_dispatch(struct ub_dev *sc)
1070 {
1071 struct ub_scsi_cmd *cmd;
1072 int rc;
1073
1074 while ((cmd = ub_cmdq_peek(sc)) != NULL) {
1075 if (cmd->state == UB_CMDST_DONE) {
1076 ub_cmdq_pop(sc);
1077 (*cmd->done)(sc, cmd);
1078 } else if (cmd->state == UB_CMDST_INIT) {
1079 ub_cmdtr_new(sc, cmd);
1080 if ((rc = ub_scsi_cmd_start(sc, cmd)) == 0)
1081 break;
1082 cmd->error = rc;
1083 cmd->state = UB_CMDST_DONE;
1084 ub_cmdtr_state(sc, cmd);
1085 } else {
1086 if (!ub_is_completed(&sc->work_done))
1087 break;
1088 ub_scsi_urb_compl(sc, cmd);
1089 }
1090 }
1091 }
1092
1093 static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1094 {
1095 struct urb *urb = &sc->work_urb;
1096 struct bulk_cs_wrap *bcs;
1097 int rc;
1098
1099 if (atomic_read(&sc->poison)) {
1100 /* A little too simplistic, I feel... */
1101 goto Bad_End;
1102 }
1103
1104 if (cmd->state == UB_CMDST_CLEAR) {
1105 if (urb->status == -EPIPE) {
1106 /*
1107 * STALL while clearning STALL.
1108 * The control pipe clears itself - nothing to do.
1109 * XXX Might try to reset the device here and retry.
1110 */
1111 printk(KERN_NOTICE "%s: stall on control pipe\n",
1112 sc->name);
1113 goto Bad_End;
1114 }
1115
1116 /*
1117 * We ignore the result for the halt clear.
1118 */
1119
1120 /* reset the endpoint toggle */
1121 usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
1122 usb_pipeout(sc->last_pipe), 0);
1123
1124 ub_state_sense(sc, cmd);
1125
1126 } else if (cmd->state == UB_CMDST_CLR2STS) {
1127 if (urb->status == -EPIPE) {
1128 /*
1129 * STALL while clearning STALL.
1130 * The control pipe clears itself - nothing to do.
1131 * XXX Might try to reset the device here and retry.
1132 */
1133 printk(KERN_NOTICE "%s: stall on control pipe\n",
1134 sc->name);
1135 goto Bad_End;
1136 }
1137
1138 /*
1139 * We ignore the result for the halt clear.
1140 */
1141
1142 /* reset the endpoint toggle */
1143 usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
1144 usb_pipeout(sc->last_pipe), 0);
1145
1146 ub_state_stat(sc, cmd);
1147
1148 } else if (cmd->state == UB_CMDST_CLRRS) {
1149 if (urb->status == -EPIPE) {
1150 /*
1151 * STALL while clearning STALL.
1152 * The control pipe clears itself - nothing to do.
1153 * XXX Might try to reset the device here and retry.
1154 */
1155 printk(KERN_NOTICE "%s: stall on control pipe\n",
1156 sc->name);
1157 goto Bad_End;
1158 }
1159
1160 /*
1161 * We ignore the result for the halt clear.
1162 */
1163
1164 /* reset the endpoint toggle */
1165 usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
1166 usb_pipeout(sc->last_pipe), 0);
1167
1168 ub_state_stat_counted(sc, cmd);
1169
1170 } else if (cmd->state == UB_CMDST_CMD) {
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 /*
1178 * This is typically ENOMEM or some other such shit.
1179 * Retrying is pointless. Just do Bad End on it...
1180 */
1181 goto Bad_End;
1182 }
1183 cmd->state = UB_CMDST_CLEAR;
1184 ub_cmdtr_state(sc, cmd);
1185 return;
1186 }
1187 if (urb->status != 0) {
1188 goto Bad_End;
1189 }
1190 if (urb->actual_length != US_BULK_CB_WRAP_LEN) {
1191 /* XXX Must do reset here to unconfuse the device */
1192 goto Bad_End;
1193 }
1194
1195 if (cmd->dir == UB_DIR_NONE || cmd->nsg < 1) {
1196 ub_state_stat(sc, cmd);
1197 return;
1198 }
1199
1200 // udelay(125); // usb-storage has this
1201 ub_data_start(sc, cmd);
1202
1203 } else if (cmd->state == UB_CMDST_DATA) {
1204 if (urb->status == -EPIPE) {
1205 rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1206 if (rc != 0) {
1207 printk(KERN_NOTICE "%s: "
1208 "unable to submit clear (%d)\n",
1209 sc->name, rc);
1210 /*
1211 * This is typically ENOMEM or some other such shit.
1212 * Retrying is pointless. Just do Bad End on it...
1213 */
1214 goto Bad_End;
1215 }
1216 cmd->state = UB_CMDST_CLR2STS;
1217 ub_cmdtr_state(sc, cmd);
1218 return;
1219 }
1220 if (urb->status == -EOVERFLOW) {
1221 /*
1222 * A babble? Failure, but we must transfer CSW now.
1223 * XXX This is going to end in perpetual babble. Reset.
1224 */
1225 cmd->error = -EOVERFLOW; /* A cheap trick... */
1226 ub_state_stat(sc, cmd);
1227 return;
1228 }
1229 if (urb->status != 0)
1230 goto Bad_End;
1231
1232 cmd->act_len += urb->actual_length;
1233 ub_cmdtr_act_len(sc, cmd);
1234
1235 if (++cmd->current_sg < cmd->nsg) {
1236 ub_data_start(sc, cmd);
1237 return;
1238 }
1239 ub_state_stat(sc, cmd);
1240
1241 } else if (cmd->state == UB_CMDST_STAT) {
1242 if (urb->status == -EPIPE) {
1243 rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1244 if (rc != 0) {
1245 printk(KERN_NOTICE "%s: "
1246 "unable to submit clear (%d)\n",
1247 sc->name, rc);
1248 /*
1249 * This is typically ENOMEM or some other such shit.
1250 * Retrying is pointless. Just do Bad End on it...
1251 */
1252 goto Bad_End;
1253 }
1254
1255 /*
1256 * Having a stall when getting CSW is an error, so
1257 * make sure uppper levels are not oblivious to it.
1258 */
1259 cmd->error = -EIO; /* A cheap trick... */
1260
1261 cmd->state = UB_CMDST_CLRRS;
1262 ub_cmdtr_state(sc, cmd);
1263 return;
1264 }
1265 if (urb->status == -EOVERFLOW) {
1266 /*
1267 * XXX We are screwed here. Retrying is pointless,
1268 * because the pipelined data will not get in until
1269 * we read with a big enough buffer. We must reset XXX.
1270 */
1271 goto Bad_End;
1272 }
1273 if (urb->status != 0)
1274 goto Bad_End;
1275
1276 if (urb->actual_length == 0) {
1277 ub_state_stat_counted(sc, cmd);
1278 return;
1279 }
1280
1281 /*
1282 * Check the returned Bulk protocol status.
1283 * The status block has to be validated first.
1284 */
1285
1286 bcs = &sc->work_bcs;
1287
1288 if (sc->signature == cpu_to_le32(0)) {
1289 /*
1290 * This is the first reply, so do not perform the check.
1291 * Instead, remember the signature the device uses
1292 * for future checks. But do not allow a nul.
1293 */
1294 sc->signature = bcs->Signature;
1295 if (sc->signature == cpu_to_le32(0)) {
1296 ub_state_stat_counted(sc, cmd);
1297 return;
1298 }
1299 } else {
1300 if (bcs->Signature != sc->signature) {
1301 ub_state_stat_counted(sc, cmd);
1302 return;
1303 }
1304 }
1305
1306 if (bcs->Tag != cmd->tag) {
1307 /*
1308 * This usually happens when we disagree with the
1309 * device's microcode about something. For instance,
1310 * a few of them throw this after timeouts. They buffer
1311 * commands and reply at commands we timed out before.
1312 * Without flushing these replies we loop forever.
1313 */
1314 ub_state_stat_counted(sc, cmd);
1315 return;
1316 }
1317
1318 rc = le32_to_cpu(bcs->Residue);
1319 if (rc != cmd->len - cmd->act_len) {
1320 /*
1321 * It is all right to transfer less, the caller has
1322 * to check. But it's not all right if the device
1323 * counts disagree with our counts.
1324 */
1325 /* P3 */ printk("%s: resid %d len %d act %d\n",
1326 sc->name, rc, cmd->len, cmd->act_len);
1327 goto Bad_End;
1328 }
1329
1330 switch (bcs->Status) {
1331 case US_BULK_STAT_OK:
1332 break;
1333 case US_BULK_STAT_FAIL:
1334 ub_state_sense(sc, cmd);
1335 return;
1336 case US_BULK_STAT_PHASE:
1337 /* XXX We must reset the transport here */
1338 /* P3 */ printk("%s: status PHASE\n", sc->name);
1339 goto Bad_End;
1340 default:
1341 printk(KERN_INFO "%s: unknown CSW status 0x%x\n",
1342 sc->name, bcs->Status);
1343 goto Bad_End;
1344 }
1345
1346 /* Not zeroing error to preserve a babble indicator */
1347 if (cmd->error != 0) {
1348 ub_state_sense(sc, cmd);
1349 return;
1350 }
1351 cmd->state = UB_CMDST_DONE;
1352 ub_cmdtr_state(sc, cmd);
1353 ub_cmdq_pop(sc);
1354 (*cmd->done)(sc, cmd);
1355
1356 } else if (cmd->state == UB_CMDST_SENSE) {
1357 ub_state_done(sc, cmd, -EIO);
1358
1359 } else {
1360 printk(KERN_WARNING "%s: "
1361 "wrong command state %d\n",
1362 sc->name, cmd->state);
1363 goto Bad_End;
1364 }
1365 return;
1366
1367 Bad_End: /* Little Excel is dead */
1368 ub_state_done(sc, cmd, -EIO);
1369 }
1370
1371 /*
1372 * Factorization helper for the command state machine:
1373 * Initiate a data segment transfer.
1374 */
1375 static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1376 {
1377 struct scatterlist *sg = &cmd->sgv[cmd->current_sg];
1378 int pipe;
1379 int rc;
1380
1381 UB_INIT_COMPLETION(sc->work_done);
1382
1383 if (cmd->dir == UB_DIR_READ)
1384 pipe = sc->recv_bulk_pipe;
1385 else
1386 pipe = sc->send_bulk_pipe;
1387 sc->last_pipe = pipe;
1388 usb_fill_bulk_urb(&sc->work_urb, sc->dev, pipe,
1389 page_address(sg->page) + sg->offset, sg->length,
1390 ub_urb_complete, sc);
1391 sc->work_urb.actual_length = 0;
1392 sc->work_urb.error_count = 0;
1393 sc->work_urb.status = 0;
1394
1395 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1396 /* XXX Clear stalls */
1397 ub_complete(&sc->work_done);
1398 ub_state_done(sc, cmd, rc);
1399 return;
1400 }
1401
1402 sc->work_timer.expires = jiffies + UB_DATA_TIMEOUT;
1403 add_timer(&sc->work_timer);
1404
1405 cmd->state = UB_CMDST_DATA;
1406 ub_cmdtr_state(sc, cmd);
1407 }
1408
1409 /*
1410 * Factorization helper for the command state machine:
1411 * Finish the command.
1412 */
1413 static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc)
1414 {
1415
1416 cmd->error = rc;
1417 cmd->state = UB_CMDST_DONE;
1418 ub_cmdtr_state(sc, cmd);
1419 ub_cmdq_pop(sc);
1420 (*cmd->done)(sc, cmd);
1421 }
1422
1423 /*
1424 * Factorization helper for the command state machine:
1425 * Submit a CSW read.
1426 */
1427 static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1428 {
1429 int rc;
1430
1431 UB_INIT_COMPLETION(sc->work_done);
1432
1433 sc->last_pipe = sc->recv_bulk_pipe;
1434 usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->recv_bulk_pipe,
1435 &sc->work_bcs, US_BULK_CS_WRAP_LEN, ub_urb_complete, sc);
1436 sc->work_urb.actual_length = 0;
1437 sc->work_urb.error_count = 0;
1438 sc->work_urb.status = 0;
1439
1440 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1441 /* XXX Clear stalls */
1442 ub_complete(&sc->work_done);
1443 ub_state_done(sc, cmd, rc);
1444 return -1;
1445 }
1446
1447 sc->work_timer.expires = jiffies + UB_STAT_TIMEOUT;
1448 add_timer(&sc->work_timer);
1449 return 0;
1450 }
1451
1452 /*
1453 * Factorization helper for the command state machine:
1454 * Submit a CSW read and go to STAT state.
1455 */
1456 static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1457 {
1458
1459 if (__ub_state_stat(sc, cmd) != 0)
1460 return;
1461
1462 cmd->stat_count = 0;
1463 cmd->state = UB_CMDST_STAT;
1464 ub_cmdtr_state(sc, cmd);
1465 }
1466
1467 /*
1468 * Factorization helper for the command state machine:
1469 * Submit a CSW read and go to STAT state with counter (along [C] path).
1470 */
1471 static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1472 {
1473
1474 if (++cmd->stat_count >= 4) {
1475 ub_state_sense(sc, cmd);
1476 return;
1477 }
1478
1479 if (__ub_state_stat(sc, cmd) != 0)
1480 return;
1481
1482 cmd->state = UB_CMDST_STAT;
1483 ub_cmdtr_state(sc, cmd);
1484 }
1485
1486 /*
1487 * Factorization helper for the command state machine:
1488 * Submit a REQUEST SENSE and go to SENSE state.
1489 */
1490 static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1491 {
1492 struct ub_scsi_cmd *scmd;
1493 struct scatterlist *sg;
1494 int rc;
1495
1496 if (cmd->cdb[0] == REQUEST_SENSE) {
1497 rc = -EPIPE;
1498 goto error;
1499 }
1500
1501 scmd = &sc->top_rqs_cmd;
1502 memset(scmd, 0, sizeof(struct ub_scsi_cmd));
1503 scmd->cdb[0] = REQUEST_SENSE;
1504 scmd->cdb[4] = UB_SENSE_SIZE;
1505 scmd->cdb_len = 6;
1506 scmd->dir = UB_DIR_READ;
1507 scmd->state = UB_CMDST_INIT;
1508 scmd->nsg = 1;
1509 sg = &scmd->sgv[0];
1510 sg->page = virt_to_page(sc->top_sense);
1511 sg->offset = (unsigned long)sc->top_sense & (PAGE_SIZE-1);
1512 sg->length = UB_SENSE_SIZE;
1513 scmd->len = UB_SENSE_SIZE;
1514 scmd->lun = cmd->lun;
1515 scmd->done = ub_top_sense_done;
1516 scmd->back = cmd;
1517
1518 scmd->tag = sc->tagcnt++;
1519
1520 cmd->state = UB_CMDST_SENSE;
1521 ub_cmdtr_state(sc, cmd);
1522
1523 ub_cmdq_insert(sc, scmd);
1524 return;
1525
1526 error:
1527 ub_state_done(sc, cmd, rc);
1528 }
1529
1530 /*
1531 * A helper for the command's state machine:
1532 * Submit a stall clear.
1533 */
1534 static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
1535 int stalled_pipe)
1536 {
1537 int endp;
1538 struct usb_ctrlrequest *cr;
1539 int rc;
1540
1541 endp = usb_pipeendpoint(stalled_pipe);
1542 if (usb_pipein (stalled_pipe))
1543 endp |= USB_DIR_IN;
1544
1545 cr = &sc->work_cr;
1546 cr->bRequestType = USB_RECIP_ENDPOINT;
1547 cr->bRequest = USB_REQ_CLEAR_FEATURE;
1548 cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
1549 cr->wIndex = cpu_to_le16(endp);
1550 cr->wLength = cpu_to_le16(0);
1551
1552 UB_INIT_COMPLETION(sc->work_done);
1553
1554 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
1555 (unsigned char*) cr, NULL, 0, ub_urb_complete, sc);
1556 sc->work_urb.actual_length = 0;
1557 sc->work_urb.error_count = 0;
1558 sc->work_urb.status = 0;
1559
1560 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1561 ub_complete(&sc->work_done);
1562 return rc;
1563 }
1564
1565 sc->work_timer.expires = jiffies + UB_CTRL_TIMEOUT;
1566 add_timer(&sc->work_timer);
1567 return 0;
1568 }
1569
1570 /*
1571 */
1572 static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd)
1573 {
1574 unsigned char *sense = sc->top_sense;
1575 struct ub_scsi_cmd *cmd;
1576
1577 /*
1578 * Ignoring scmd->act_len, because the buffer was pre-zeroed.
1579 */
1580 ub_cmdtr_sense(sc, scmd, sense);
1581
1582 /*
1583 * Find the command which triggered the unit attention or a check,
1584 * save the sense into it, and advance its state machine.
1585 */
1586 if ((cmd = ub_cmdq_peek(sc)) == NULL) {
1587 printk(KERN_WARNING "%s: sense done while idle\n", sc->name);
1588 return;
1589 }
1590 if (cmd != scmd->back) {
1591 printk(KERN_WARNING "%s: "
1592 "sense done for wrong command 0x%x\n",
1593 sc->name, cmd->tag);
1594 return;
1595 }
1596 if (cmd->state != UB_CMDST_SENSE) {
1597 printk(KERN_WARNING "%s: "
1598 "sense done with bad cmd state %d\n",
1599 sc->name, cmd->state);
1600 return;
1601 }
1602
1603 cmd->key = sense[2] & 0x0F;
1604 cmd->asc = sense[12];
1605 cmd->ascq = sense[13];
1606
1607 ub_scsi_urb_compl(sc, cmd);
1608 }
1609
1610 /*
1611 * This is called from a process context.
1612 */
1613 static void ub_revalidate(struct ub_dev *sc, struct ub_lun *lun)
1614 {
1615
1616 lun->readonly = 0; /* XXX Query this from the device */
1617
1618 lun->capacity.nsec = 0;
1619 lun->capacity.bsize = 512;
1620 lun->capacity.bshift = 0;
1621
1622 if (ub_sync_tur(sc, lun) != 0)
1623 return; /* Not ready */
1624 lun->changed = 0;
1625
1626 if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
1627 /*
1628 * The retry here means something is wrong, either with the
1629 * device, with the transport, or with our code.
1630 * We keep this because sd.c has retries for capacity.
1631 */
1632 if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
1633 lun->capacity.nsec = 0;
1634 lun->capacity.bsize = 512;
1635 lun->capacity.bshift = 0;
1636 }
1637 }
1638 }
1639
1640 /*
1641 * The open funcion.
1642 * This is mostly needed to keep refcounting, but also to support
1643 * media checks on removable media drives.
1644 */
1645 static int ub_bd_open(struct inode *inode, struct file *filp)
1646 {
1647 struct gendisk *disk = inode->i_bdev->bd_disk;
1648 struct ub_lun *lun;
1649 struct ub_dev *sc;
1650 unsigned long flags;
1651 int rc;
1652
1653 if ((lun = disk->private_data) == NULL)
1654 return -ENXIO;
1655 sc = lun->udev;
1656
1657 spin_lock_irqsave(&ub_lock, flags);
1658 if (atomic_read(&sc->poison)) {
1659 spin_unlock_irqrestore(&ub_lock, flags);
1660 return -ENXIO;
1661 }
1662 sc->openc++;
1663 spin_unlock_irqrestore(&ub_lock, flags);
1664
1665 /*
1666 * This is a workaround for a specific problem in our block layer.
1667 * In 2.6.9, register_disk duplicates the code from rescan_partitions.
1668 * However, if we do add_disk with a device which persistently reports
1669 * a changed media, add_disk calls register_disk, which does do_open,
1670 * which will call rescan_paritions for changed media. After that,
1671 * register_disk attempts to do it all again and causes double kobject
1672 * registration and a eventually an oops on module removal.
1673 *
1674 * The bottom line is, Al Viro says that we should not allow
1675 * bdev->bd_invalidated to be set when doing add_disk no matter what.
1676 */
1677 if (lun->first_open) {
1678 lun->first_open = 0;
1679 if (lun->changed) {
1680 rc = -ENOMEDIUM;
1681 goto err_open;
1682 }
1683 }
1684
1685 if (lun->removable || lun->readonly)
1686 check_disk_change(inode->i_bdev);
1687
1688 /*
1689 * The sd.c considers ->media_present and ->changed not equivalent,
1690 * under some pretty murky conditions (a failure of READ CAPACITY).
1691 * We may need it one day.
1692 */
1693 if (lun->removable && lun->changed && !(filp->f_flags & O_NDELAY)) {
1694 rc = -ENOMEDIUM;
1695 goto err_open;
1696 }
1697
1698 if (lun->readonly && (filp->f_mode & FMODE_WRITE)) {
1699 rc = -EROFS;
1700 goto err_open;
1701 }
1702
1703 return 0;
1704
1705 err_open:
1706 ub_put(sc);
1707 return rc;
1708 }
1709
1710 /*
1711 */
1712 static int ub_bd_release(struct inode *inode, struct file *filp)
1713 {
1714 struct gendisk *disk = inode->i_bdev->bd_disk;
1715 struct ub_lun *lun = disk->private_data;
1716 struct ub_dev *sc = lun->udev;
1717
1718 ub_put(sc);
1719 return 0;
1720 }
1721
1722 /*
1723 * The ioctl interface.
1724 */
1725 static int ub_bd_ioctl(struct inode *inode, struct file *filp,
1726 unsigned int cmd, unsigned long arg)
1727 {
1728 struct gendisk *disk = inode->i_bdev->bd_disk;
1729 void __user *usermem = (void __user *) arg;
1730
1731 return scsi_cmd_ioctl(filp, disk, cmd, usermem);
1732 }
1733
1734 /*
1735 * This is called once a new disk was seen by the block layer or by ub_probe().
1736 * The main onjective here is to discover the features of the media such as
1737 * the capacity, read-only status, etc. USB storage generally does not
1738 * need to be spun up, but if we needed it, this would be the place.
1739 *
1740 * This call can sleep.
1741 *
1742 * The return code is not used.
1743 */
1744 static int ub_bd_revalidate(struct gendisk *disk)
1745 {
1746 struct ub_lun *lun = disk->private_data;
1747
1748 ub_revalidate(lun->udev, lun);
1749
1750 /* XXX Support sector size switching like in sr.c */
1751 blk_queue_hardsect_size(disk->queue, lun->capacity.bsize);
1752 set_capacity(disk, lun->capacity.nsec);
1753 // set_disk_ro(sdkp->disk, lun->readonly);
1754
1755 return 0;
1756 }
1757
1758 /*
1759 * The check is called by the block layer to verify if the media
1760 * is still available. It is supposed to be harmless, lightweight and
1761 * non-intrusive in case the media was not changed.
1762 *
1763 * This call can sleep.
1764 *
1765 * The return code is bool!
1766 */
1767 static int ub_bd_media_changed(struct gendisk *disk)
1768 {
1769 struct ub_lun *lun = disk->private_data;
1770
1771 if (!lun->removable)
1772 return 0;
1773
1774 /*
1775 * We clean checks always after every command, so this is not
1776 * as dangerous as it looks. If the TEST_UNIT_READY fails here,
1777 * the device is actually not ready with operator or software
1778 * intervention required. One dangerous item might be a drive which
1779 * spins itself down, and come the time to write dirty pages, this
1780 * will fail, then block layer discards the data. Since we never
1781 * spin drives up, such devices simply cannot be used with ub anyway.
1782 */
1783 if (ub_sync_tur(lun->udev, lun) != 0) {
1784 lun->changed = 1;
1785 return 1;
1786 }
1787
1788 return lun->changed;
1789 }
1790
1791 static struct block_device_operations ub_bd_fops = {
1792 .owner = THIS_MODULE,
1793 .open = ub_bd_open,
1794 .release = ub_bd_release,
1795 .ioctl = ub_bd_ioctl,
1796 .media_changed = ub_bd_media_changed,
1797 .revalidate_disk = ub_bd_revalidate,
1798 };
1799
1800 /*
1801 * Common ->done routine for commands executed synchronously.
1802 */
1803 static void ub_probe_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1804 {
1805 struct completion *cop = cmd->back;
1806 complete(cop);
1807 }
1808
1809 /*
1810 * Test if the device has a check condition on it, synchronously.
1811 */
1812 static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun)
1813 {
1814 struct ub_scsi_cmd *cmd;
1815 enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) };
1816 unsigned long flags;
1817 struct completion compl;
1818 int rc;
1819
1820 init_completion(&compl);
1821
1822 rc = -ENOMEM;
1823 if ((cmd = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
1824 goto err_alloc;
1825 memset(cmd, 0, ALLOC_SIZE);
1826
1827 cmd->cdb[0] = TEST_UNIT_READY;
1828 cmd->cdb_len = 6;
1829 cmd->dir = UB_DIR_NONE;
1830 cmd->state = UB_CMDST_INIT;
1831 cmd->lun = lun; /* This may be NULL, but that's ok */
1832 cmd->done = ub_probe_done;
1833 cmd->back = &compl;
1834
1835 spin_lock_irqsave(&sc->lock, flags);
1836 cmd->tag = sc->tagcnt++;
1837
1838 rc = ub_submit_scsi(sc, cmd);
1839 spin_unlock_irqrestore(&sc->lock, flags);
1840
1841 if (rc != 0) {
1842 printk("ub: testing ready: submit error (%d)\n", rc); /* P3 */
1843 goto err_submit;
1844 }
1845
1846 wait_for_completion(&compl);
1847
1848 rc = cmd->error;
1849
1850 if (rc == -EIO && cmd->key != 0) /* Retries for benh's key */
1851 rc = cmd->key;
1852
1853 err_submit:
1854 kfree(cmd);
1855 err_alloc:
1856 return rc;
1857 }
1858
1859 /*
1860 * Read the SCSI capacity synchronously (for probing).
1861 */
1862 static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
1863 struct ub_capacity *ret)
1864 {
1865 struct ub_scsi_cmd *cmd;
1866 struct scatterlist *sg;
1867 char *p;
1868 enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) + 8 };
1869 unsigned long flags;
1870 unsigned int bsize, shift;
1871 unsigned long nsec;
1872 struct completion compl;
1873 int rc;
1874
1875 init_completion(&compl);
1876
1877 rc = -ENOMEM;
1878 if ((cmd = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
1879 goto err_alloc;
1880 memset(cmd, 0, ALLOC_SIZE);
1881 p = (char *)cmd + sizeof(struct ub_scsi_cmd);
1882
1883 cmd->cdb[0] = 0x25;
1884 cmd->cdb_len = 10;
1885 cmd->dir = UB_DIR_READ;
1886 cmd->state = UB_CMDST_INIT;
1887 cmd->nsg = 1;
1888 sg = &cmd->sgv[0];
1889 sg->page = virt_to_page(p);
1890 sg->offset = (unsigned long)p & (PAGE_SIZE-1);
1891 sg->length = 8;
1892 cmd->len = 8;
1893 cmd->lun = lun;
1894 cmd->done = ub_probe_done;
1895 cmd->back = &compl;
1896
1897 spin_lock_irqsave(&sc->lock, flags);
1898 cmd->tag = sc->tagcnt++;
1899
1900 rc = ub_submit_scsi(sc, cmd);
1901 spin_unlock_irqrestore(&sc->lock, flags);
1902
1903 if (rc != 0) {
1904 printk("ub: reading capacity: submit error (%d)\n", rc); /* P3 */
1905 goto err_submit;
1906 }
1907
1908 wait_for_completion(&compl);
1909
1910 if (cmd->error != 0) {
1911 printk("ub: reading capacity: error %d\n", cmd->error); /* P3 */
1912 rc = -EIO;
1913 goto err_read;
1914 }
1915 if (cmd->act_len != 8) {
1916 printk("ub: reading capacity: size %d\n", cmd->act_len); /* P3 */
1917 rc = -EIO;
1918 goto err_read;
1919 }
1920
1921 /* sd.c special-cases sector size of 0 to mean 512. Needed? Safe? */
1922 nsec = be32_to_cpu(*(__be32 *)p) + 1;
1923 bsize = be32_to_cpu(*(__be32 *)(p + 4));
1924 switch (bsize) {
1925 case 512: shift = 0; break;
1926 case 1024: shift = 1; break;
1927 case 2048: shift = 2; break;
1928 case 4096: shift = 3; break;
1929 default:
1930 printk("ub: Bad sector size %u\n", bsize); /* P3 */
1931 rc = -EDOM;
1932 goto err_inv_bsize;
1933 }
1934
1935 ret->bsize = bsize;
1936 ret->bshift = shift;
1937 ret->nsec = nsec << shift;
1938 rc = 0;
1939
1940 err_inv_bsize:
1941 err_read:
1942 err_submit:
1943 kfree(cmd);
1944 err_alloc:
1945 return rc;
1946 }
1947
1948 /*
1949 */
1950 static void ub_probe_urb_complete(struct urb *urb, struct pt_regs *pt)
1951 {
1952 struct completion *cop = urb->context;
1953 complete(cop);
1954 }
1955
1956 static void ub_probe_timeout(unsigned long arg)
1957 {
1958 struct completion *cop = (struct completion *) arg;
1959 complete(cop);
1960 }
1961
1962 /*
1963 * Get number of LUNs by the way of Bulk GetMaxLUN command.
1964 */
1965 static int ub_sync_getmaxlun(struct ub_dev *sc)
1966 {
1967 int ifnum = sc->intf->cur_altsetting->desc.bInterfaceNumber;
1968 unsigned char *p;
1969 enum { ALLOC_SIZE = 1 };
1970 struct usb_ctrlrequest *cr;
1971 struct completion compl;
1972 struct timer_list timer;
1973 int nluns;
1974 int rc;
1975
1976 init_completion(&compl);
1977
1978 rc = -ENOMEM;
1979 if ((p = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
1980 goto err_alloc;
1981 *p = 55;
1982
1983 cr = &sc->work_cr;
1984 cr->bRequestType = USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE;
1985 cr->bRequest = US_BULK_GET_MAX_LUN;
1986 cr->wValue = cpu_to_le16(0);
1987 cr->wIndex = cpu_to_le16(ifnum);
1988 cr->wLength = cpu_to_le16(1);
1989
1990 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->recv_ctrl_pipe,
1991 (unsigned char*) cr, p, 1, ub_probe_urb_complete, &compl);
1992 sc->work_urb.actual_length = 0;
1993 sc->work_urb.error_count = 0;
1994 sc->work_urb.status = 0;
1995
1996 if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
1997 if (rc == -EPIPE) {
1998 printk("%s: Stall submitting GetMaxLUN, using 1 LUN\n",
1999 sc->name); /* P3 */
2000 } else {
2001 printk(KERN_NOTICE
2002 "%s: Unable to submit GetMaxLUN (%d)\n",
2003 sc->name, rc);
2004 }
2005 goto err_submit;
2006 }
2007
2008 init_timer(&timer);
2009 timer.function = ub_probe_timeout;
2010 timer.data = (unsigned long) &compl;
2011 timer.expires = jiffies + UB_CTRL_TIMEOUT;
2012 add_timer(&timer);
2013
2014 wait_for_completion(&compl);
2015
2016 del_timer_sync(&timer);
2017 usb_kill_urb(&sc->work_urb);
2018
2019 if ((rc = sc->work_urb.status) < 0) {
2020 if (rc == -EPIPE) {
2021 printk("%s: Stall at GetMaxLUN, using 1 LUN\n",
2022 sc->name); /* P3 */
2023 } else {
2024 printk(KERN_NOTICE
2025 "%s: Error at GetMaxLUN (%d)\n",
2026 sc->name, rc);
2027 }
2028 goto err_io;
2029 }
2030
2031 if (sc->work_urb.actual_length != 1) {
2032 printk("%s: GetMaxLUN returned %d bytes\n", sc->name,
2033 sc->work_urb.actual_length); /* P3 */
2034 nluns = 0;
2035 } else {
2036 if ((nluns = *p) == 55) {
2037 nluns = 0;
2038 } else {
2039 /* GetMaxLUN returns the maximum LUN number */
2040 nluns += 1;
2041 if (nluns > UB_MAX_LUNS)
2042 nluns = UB_MAX_LUNS;
2043 }
2044 printk("%s: GetMaxLUN returned %d, using %d LUNs\n", sc->name,
2045 *p, nluns); /* P3 */
2046 }
2047
2048 kfree(p);
2049 return nluns;
2050
2051 err_io:
2052 err_submit:
2053 kfree(p);
2054 err_alloc:
2055 return rc;
2056 }
2057
2058 /*
2059 * Clear initial stalls.
2060 */
2061 static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe)
2062 {
2063 int endp;
2064 struct usb_ctrlrequest *cr;
2065 struct completion compl;
2066 struct timer_list timer;
2067 int rc;
2068
2069 init_completion(&compl);
2070
2071 endp = usb_pipeendpoint(stalled_pipe);
2072 if (usb_pipein (stalled_pipe))
2073 endp |= USB_DIR_IN;
2074
2075 cr = &sc->work_cr;
2076 cr->bRequestType = USB_RECIP_ENDPOINT;
2077 cr->bRequest = USB_REQ_CLEAR_FEATURE;
2078 cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
2079 cr->wIndex = cpu_to_le16(endp);
2080 cr->wLength = cpu_to_le16(0);
2081
2082 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
2083 (unsigned char*) cr, NULL, 0, ub_probe_urb_complete, &compl);
2084 sc->work_urb.actual_length = 0;
2085 sc->work_urb.error_count = 0;
2086 sc->work_urb.status = 0;
2087
2088 if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
2089 printk(KERN_WARNING
2090 "%s: Unable to submit a probe clear (%d)\n", sc->name, rc);
2091 return rc;
2092 }
2093
2094 init_timer(&timer);
2095 timer.function = ub_probe_timeout;
2096 timer.data = (unsigned long) &compl;
2097 timer.expires = jiffies + UB_CTRL_TIMEOUT;
2098 add_timer(&timer);
2099
2100 wait_for_completion(&compl);
2101
2102 del_timer_sync(&timer);
2103 usb_kill_urb(&sc->work_urb);
2104
2105 /* reset the endpoint toggle */
2106 usb_settoggle(sc->dev, endp, usb_pipeout(sc->last_pipe), 0);
2107
2108 return 0;
2109 }
2110
2111 /*
2112 * Get the pipe settings.
2113 */
2114 static int ub_get_pipes(struct ub_dev *sc, struct usb_device *dev,
2115 struct usb_interface *intf)
2116 {
2117 struct usb_host_interface *altsetting = intf->cur_altsetting;
2118 struct usb_endpoint_descriptor *ep_in = NULL;
2119 struct usb_endpoint_descriptor *ep_out = NULL;
2120 struct usb_endpoint_descriptor *ep;
2121 int i;
2122
2123 /*
2124 * Find the endpoints we need.
2125 * We are expecting a minimum of 2 endpoints - in and out (bulk).
2126 * We will ignore any others.
2127 */
2128 for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
2129 ep = &altsetting->endpoint[i].desc;
2130
2131 /* Is it a BULK endpoint? */
2132 if ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
2133 == USB_ENDPOINT_XFER_BULK) {
2134 /* BULK in or out? */
2135 if (ep->bEndpointAddress & USB_DIR_IN)
2136 ep_in = ep;
2137 else
2138 ep_out = ep;
2139 }
2140 }
2141
2142 if (ep_in == NULL || ep_out == NULL) {
2143 printk(KERN_NOTICE "%s: failed endpoint check\n",
2144 sc->name);
2145 return -EIO;
2146 }
2147
2148 /* Calculate and store the pipe values */
2149 sc->send_ctrl_pipe = usb_sndctrlpipe(dev, 0);
2150 sc->recv_ctrl_pipe = usb_rcvctrlpipe(dev, 0);
2151 sc->send_bulk_pipe = usb_sndbulkpipe(dev,
2152 ep_out->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2153 sc->recv_bulk_pipe = usb_rcvbulkpipe(dev,
2154 ep_in->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2155
2156 return 0;
2157 }
2158
2159 /*
2160 * Probing is done in the process context, which allows us to cheat
2161 * and not to build a state machine for the discovery.
2162 */
2163 static int ub_probe(struct usb_interface *intf,
2164 const struct usb_device_id *dev_id)
2165 {
2166 struct ub_dev *sc;
2167 int nluns;
2168 int rc;
2169 int i;
2170
2171 if (usb_usual_check_type(dev_id, USB_US_TYPE_UB))
2172 return -ENXIO;
2173
2174 rc = -ENOMEM;
2175 if ((sc = kmalloc(sizeof(struct ub_dev), GFP_KERNEL)) == NULL)
2176 goto err_core;
2177 memset(sc, 0, sizeof(struct ub_dev));
2178 spin_lock_init(&sc->lock);
2179 INIT_LIST_HEAD(&sc->luns);
2180 usb_init_urb(&sc->work_urb);
2181 tasklet_init(&sc->tasklet, ub_scsi_action, (unsigned long)sc);
2182 atomic_set(&sc->poison, 0);
2183
2184 init_timer(&sc->work_timer);
2185 sc->work_timer.data = (unsigned long) sc;
2186 sc->work_timer.function = ub_urb_timeout;
2187
2188 ub_init_completion(&sc->work_done);
2189 sc->work_done.done = 1; /* A little yuk, but oh well... */
2190
2191 sc->dev = interface_to_usbdev(intf);
2192 sc->intf = intf;
2193 // sc->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
2194 usb_set_intfdata(intf, sc);
2195 usb_get_dev(sc->dev);
2196 // usb_get_intf(sc->intf); /* Do we need this? */
2197
2198 snprintf(sc->name, 12, DRV_NAME "(%d.%d)",
2199 sc->dev->bus->busnum, sc->dev->devnum);
2200
2201 /* XXX Verify that we can handle the device (from descriptors) */
2202
2203 ub_get_pipes(sc, sc->dev, intf);
2204
2205 if (device_create_file(&sc->intf->dev, &dev_attr_diag) != 0)
2206 goto err_diag;
2207
2208 /*
2209 * At this point, all USB initialization is done, do upper layer.
2210 * We really hate halfway initialized structures, so from the
2211 * invariants perspective, this ub_dev is fully constructed at
2212 * this point.
2213 */
2214
2215 /*
2216 * This is needed to clear toggles. It is a problem only if we do
2217 * `rmmod ub && modprobe ub` without disconnects, but we like that.
2218 */
2219 #if 0 /* iPod Mini fails if we do this (big white iPod works) */
2220 ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
2221 ub_probe_clear_stall(sc, sc->send_bulk_pipe);
2222 #endif
2223
2224 /*
2225 * The way this is used by the startup code is a little specific.
2226 * A SCSI check causes a USB stall. Our common case code sees it
2227 * and clears the check, after which the device is ready for use.
2228 * But if a check was not present, any command other than
2229 * TEST_UNIT_READY ends with a lockup (including REQUEST_SENSE).
2230 *
2231 * If we neglect to clear the SCSI check, the first real command fails
2232 * (which is the capacity readout). We clear that and retry, but why
2233 * causing spurious retries for no reason.
2234 *
2235 * Revalidation may start with its own TEST_UNIT_READY, but that one
2236 * has to succeed, so we clear checks with an additional one here.
2237 * In any case it's not our business how revaliadation is implemented.
2238 */
2239 for (i = 0; i < 3; i++) { /* Retries for benh's key */
2240 if ((rc = ub_sync_tur(sc, NULL)) <= 0) break;
2241 if (rc != 0x6) break;
2242 msleep(10);
2243 }
2244
2245 nluns = 1;
2246 for (i = 0; i < 3; i++) {
2247 if ((rc = ub_sync_getmaxlun(sc)) < 0) {
2248 /*
2249 * This segment is taken from usb-storage. They say
2250 * that ZIP-100 needs this, but my own ZIP-100 works
2251 * fine without this.
2252 * Still, it does not seem to hurt anything.
2253 */
2254 if (rc == -EPIPE) {
2255 ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
2256 ub_probe_clear_stall(sc, sc->send_bulk_pipe);
2257 }
2258 break;
2259 }
2260 if (rc != 0) {
2261 nluns = rc;
2262 break;
2263 }
2264 msleep(100);
2265 }
2266
2267 for (i = 0; i < nluns; i++) {
2268 ub_probe_lun(sc, i);
2269 }
2270 return 0;
2271
2272 /* device_remove_file(&sc->intf->dev, &dev_attr_diag); */
2273 err_diag:
2274 usb_set_intfdata(intf, NULL);
2275 // usb_put_intf(sc->intf);
2276 usb_put_dev(sc->dev);
2277 kfree(sc);
2278 err_core:
2279 return rc;
2280 }
2281
2282 static int ub_probe_lun(struct ub_dev *sc, int lnum)
2283 {
2284 struct ub_lun *lun;
2285 request_queue_t *q;
2286 struct gendisk *disk;
2287 int rc;
2288
2289 rc = -ENOMEM;
2290 if ((lun = kmalloc(sizeof(struct ub_lun), GFP_KERNEL)) == NULL)
2291 goto err_alloc;
2292 memset(lun, 0, sizeof(struct ub_lun));
2293 lun->num = lnum;
2294
2295 rc = -ENOSR;
2296 if ((lun->id = ub_id_get()) == -1)
2297 goto err_id;
2298
2299 lun->udev = sc;
2300 list_add(&lun->link, &sc->luns);
2301
2302 snprintf(lun->name, 16, DRV_NAME "%c(%d.%d.%d)",
2303 lun->id + 'a', sc->dev->bus->busnum, sc->dev->devnum, lun->num);
2304
2305 lun->removable = 1; /* XXX Query this from the device */
2306 lun->changed = 1; /* ub_revalidate clears only */
2307 lun->first_open = 1;
2308 ub_revalidate(sc, lun);
2309
2310 rc = -ENOMEM;
2311 if ((disk = alloc_disk(UB_MINORS_PER_MAJOR)) == NULL)
2312 goto err_diskalloc;
2313
2314 lun->disk = disk;
2315 sprintf(disk->disk_name, DRV_NAME "%c", lun->id + 'a');
2316 sprintf(disk->devfs_name, DEVFS_NAME "/%c", lun->id + 'a');
2317 disk->major = UB_MAJOR;
2318 disk->first_minor = lun->id * UB_MINORS_PER_MAJOR;
2319 disk->fops = &ub_bd_fops;
2320 disk->private_data = lun;
2321 disk->driverfs_dev = &sc->intf->dev;
2322
2323 rc = -ENOMEM;
2324 if ((q = blk_init_queue(ub_request_fn, &sc->lock)) == NULL)
2325 goto err_blkqinit;
2326
2327 disk->queue = q;
2328
2329 blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
2330 blk_queue_max_hw_segments(q, UB_MAX_REQ_SG);
2331 blk_queue_max_phys_segments(q, UB_MAX_REQ_SG);
2332 blk_queue_segment_boundary(q, 0xffffffff); /* Dubious. */
2333 blk_queue_max_sectors(q, UB_MAX_SECTORS);
2334 blk_queue_hardsect_size(q, lun->capacity.bsize);
2335
2336 q->queuedata = lun;
2337
2338 set_capacity(disk, lun->capacity.nsec);
2339 if (lun->removable)
2340 disk->flags |= GENHD_FL_REMOVABLE;
2341
2342 add_disk(disk);
2343
2344 return 0;
2345
2346 err_blkqinit:
2347 put_disk(disk);
2348 err_diskalloc:
2349 list_del(&lun->link);
2350 ub_id_put(lun->id);
2351 err_id:
2352 kfree(lun);
2353 err_alloc:
2354 return rc;
2355 }
2356
2357 static void ub_disconnect(struct usb_interface *intf)
2358 {
2359 struct ub_dev *sc = usb_get_intfdata(intf);
2360 struct list_head *p;
2361 struct ub_lun *lun;
2362 struct gendisk *disk;
2363 unsigned long flags;
2364
2365 /*
2366 * Prevent ub_bd_release from pulling the rug from under us.
2367 * XXX This is starting to look like a kref.
2368 * XXX Why not to take this ref at probe time?
2369 */
2370 spin_lock_irqsave(&ub_lock, flags);
2371 sc->openc++;
2372 spin_unlock_irqrestore(&ub_lock, flags);
2373
2374 /*
2375 * Fence stall clearnings, operations triggered by unlinkings and so on.
2376 * We do not attempt to unlink any URBs, because we do not trust the
2377 * unlink paths in HC drivers. Also, we get -84 upon disconnect anyway.
2378 */
2379 atomic_set(&sc->poison, 1);
2380
2381 /*
2382 * Blow away queued commands.
2383 *
2384 * Actually, this never works, because before we get here
2385 * the HCD terminates outstanding URB(s). It causes our
2386 * SCSI command queue to advance, commands fail to submit,
2387 * and the whole queue drains. So, we just use this code to
2388 * print warnings.
2389 */
2390 spin_lock_irqsave(&sc->lock, flags);
2391 {
2392 struct ub_scsi_cmd *cmd;
2393 int cnt = 0;
2394 while ((cmd = ub_cmdq_pop(sc)) != NULL) {
2395 cmd->error = -ENOTCONN;
2396 cmd->state = UB_CMDST_DONE;
2397 ub_cmdtr_state(sc, cmd);
2398 ub_cmdq_pop(sc);
2399 (*cmd->done)(sc, cmd);
2400 cnt++;
2401 }
2402 if (cnt != 0) {
2403 printk(KERN_WARNING "%s: "
2404 "%d was queued after shutdown\n", sc->name, cnt);
2405 }
2406 }
2407 spin_unlock_irqrestore(&sc->lock, flags);
2408
2409 /*
2410 * Unregister the upper layer.
2411 */
2412 list_for_each (p, &sc->luns) {
2413 lun = list_entry(p, struct ub_lun, link);
2414 disk = lun->disk;
2415 if (disk->flags & GENHD_FL_UP)
2416 del_gendisk(disk);
2417 /*
2418 * I wish I could do:
2419 * set_bit(QUEUE_FLAG_DEAD, &q->queue_flags);
2420 * As it is, we rely on our internal poisoning and let
2421 * the upper levels to spin furiously failing all the I/O.
2422 */
2423 }
2424
2425 /*
2426 * Taking a lock on a structure which is about to be freed
2427 * is very nonsensual. Here it is largely a way to do a debug freeze,
2428 * and a bracket which shows where the nonsensual code segment ends.
2429 *
2430 * Testing for -EINPROGRESS is always a bug, so we are bending
2431 * the rules a little.
2432 */
2433 spin_lock_irqsave(&sc->lock, flags);
2434 if (sc->work_urb.status == -EINPROGRESS) { /* janitors: ignore */
2435 printk(KERN_WARNING "%s: "
2436 "URB is active after disconnect\n", sc->name);
2437 }
2438 spin_unlock_irqrestore(&sc->lock, flags);
2439
2440 /*
2441 * There is virtually no chance that other CPU runs times so long
2442 * after ub_urb_complete should have called del_timer, but only if HCD
2443 * didn't forget to deliver a callback on unlink.
2444 */
2445 del_timer_sync(&sc->work_timer);
2446
2447 /*
2448 * At this point there must be no commands coming from anyone
2449 * and no URBs left in transit.
2450 */
2451
2452 device_remove_file(&sc->intf->dev, &dev_attr_diag);
2453 usb_set_intfdata(intf, NULL);
2454 // usb_put_intf(sc->intf);
2455 sc->intf = NULL;
2456 usb_put_dev(sc->dev);
2457 sc->dev = NULL;
2458
2459 ub_put(sc);
2460 }
2461
2462 static struct usb_driver ub_driver = {
2463 .owner = THIS_MODULE,
2464 .name = "ub",
2465 .probe = ub_probe,
2466 .disconnect = ub_disconnect,
2467 .id_table = ub_usb_ids,
2468 };
2469
2470 static int __init ub_init(void)
2471 {
2472 int rc;
2473
2474 if ((rc = register_blkdev(UB_MAJOR, DRV_NAME)) != 0)
2475 goto err_regblkdev;
2476 devfs_mk_dir(DEVFS_NAME);
2477
2478 if ((rc = usb_register(&ub_driver)) != 0)
2479 goto err_register;
2480
2481 usb_usual_set_present(USB_US_TYPE_UB);
2482 return 0;
2483
2484 err_register:
2485 devfs_remove(DEVFS_NAME);
2486 unregister_blkdev(UB_MAJOR, DRV_NAME);
2487 err_regblkdev:
2488 return rc;
2489 }
2490
2491 static void __exit ub_exit(void)
2492 {
2493 usb_deregister(&ub_driver);
2494
2495 devfs_remove(DEVFS_NAME);
2496 unregister_blkdev(UB_MAJOR, DRV_NAME);
2497 usb_usual_clear_present(USB_US_TYPE_UB);
2498 }
2499
2500 module_init(ub_init);
2501 module_exit(ub_exit);
2502
2503 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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