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[NETFILTER]: ipt_helper.c needs linux/interrupt.h
[linux-2.6/kvm.git] / drivers / block / ub.c
bloba05fe5843e6c7ee5645d9c5b71572c5d0632d4e6
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 * -- set readonly flag for CDs, set removable flag for CF readers
13 * -- do inquiry and verify we got a disk and not a tape (for LUN mismatch)
14 * -- special case some senses, e.g. 3a/0 -> no media present, reduce retries
15 * -- verify the 13 conditions and do bulk resets
16 * -- kill last_pipe and simply do two-state clearing on both pipes
17 * -- verify protocol (bulk) from USB descriptors (maybe...)
18 * -- highmem
19 * -- move top_sense and work_bcs into separate allocations (if they survive)
20 * for cache purists and esoteric architectures.
21 * -- Allocate structure for LUN 0 before the first ub_sync_tur, avoid NULL. ?
22 * -- prune comments, they are too volumnous
23 * -- Exterminate P3 printks
24 * -- Resove XXX's
25 * -- Redo "benh's retries", perhaps have spin-up code to handle them. V:D=?
26 * -- CLEAR, CLR2STS, CLRRS seem to be ripe for refactoring.
27 */
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/usb.h>
31 #include <linux/usb_usual.h>
32 #include <linux/blkdev.h>
33 #include <linux/devfs_fs_kernel.h>
34 #include <linux/timer.h>
35 #include <scsi/scsi.h>
36
37 #define DRV_NAME "ub"
38 #define DEVFS_NAME DRV_NAME
39
40 #define UB_MAJOR 180
41
42 /*
43 * The command state machine is the key model for understanding of this driver.
44 *
45 * The general rule is that all transitions are done towards the bottom
46 * of the diagram, thus preventing any loops.
47 *
48 * An exception to that is how the STAT state is handled. A counter allows it
49 * to be re-entered along the path marked with [C].
50 *
51 * +--------+
52 * ! INIT !
53 * +--------+
54 * !
55 * ub_scsi_cmd_start fails ->--------------------------------------\
56 * ! !
57 * V !
58 * +--------+ !
59 * ! CMD ! !
60 * +--------+ !
61 * ! +--------+ !
62 * was -EPIPE -->-------------------------------->! CLEAR ! !
63 * ! +--------+ !
64 * ! ! !
65 * was error -->------------------------------------- ! --------->\
66 * ! ! !
67 * /--<-- cmd->dir == NONE ? ! !
68 * ! ! ! !
69 * ! V ! !
70 * ! +--------+ ! !
71 * ! ! DATA ! ! !
72 * ! +--------+ ! !
73 * ! ! +---------+ ! !
74 * ! was -EPIPE -->--------------->! CLR2STS ! ! !
75 * ! ! +---------+ ! !
76 * ! ! ! ! !
77 * ! ! was error -->---- ! --------->\
78 * ! was error -->--------------------- ! ------------- ! --------->\
79 * ! ! ! ! !
80 * ! V ! ! !
81 * \--->+--------+ ! ! !
82 * ! STAT !<--------------------------/ ! !
83 * /--->+--------+ ! !
84 * ! ! ! !
85 * [C] was -EPIPE -->-----------\ ! !
86 * ! ! ! ! !
87 * +<---- len == 0 ! ! !
88 * ! ! ! ! !
89 * ! was error -->--------------------------------------!---------->\
90 * ! ! ! ! !
91 * +<---- bad CSW ! ! !
92 * +<---- bad tag ! ! !
93 * ! ! V ! !
94 * ! ! +--------+ ! !
95 * ! ! ! CLRRS ! ! !
96 * ! ! +--------+ ! !
97 * ! ! ! ! !
98 * \------- ! --------------------[C]--------\ ! !
99 * ! ! ! !
100 * cmd->error---\ +--------+ ! !
101 * ! +--------------->! SENSE !<----------/ !
102 * STAT_FAIL----/ +--------+ !
103 * ! ! V
104 * ! V +--------+
105 * \--------------------------------\--------------------->! DONE !
106 * +--------+
107 */
108
109 /*
110 * This many LUNs per USB device.
111 * Every one of them takes a host, see UB_MAX_HOSTS.
112 */
113 #define UB_MAX_LUNS 9
114
115 /*
116 */
117
118 #define UB_PARTS_PER_LUN 8
119
120 #define UB_MAX_CDB_SIZE 16 /* Corresponds to Bulk */
121
122 #define UB_SENSE_SIZE 18
123
124 /*
125 */
126
127 /* command block wrapper */
128 struct bulk_cb_wrap {
129 __le32 Signature; /* contains 'USBC' */
130 u32 Tag; /* unique per command id */
131 __le32 DataTransferLength; /* size of data */
132 u8 Flags; /* direction in bit 0 */
133 u8 Lun; /* LUN */
134 u8 Length; /* of of the CDB */
135 u8 CDB[UB_MAX_CDB_SIZE]; /* max command */
136 };
137
138 #define US_BULK_CB_WRAP_LEN 31
139 #define US_BULK_CB_SIGN 0x43425355 /*spells out USBC */
140 #define US_BULK_FLAG_IN 1
141 #define US_BULK_FLAG_OUT 0
142
143 /* command status wrapper */
144 struct bulk_cs_wrap {
145 __le32 Signature; /* should = 'USBS' */
146 u32 Tag; /* same as original command */
147 __le32 Residue; /* amount not transferred */
148 u8 Status; /* see below */
149 };
150
151 #define US_BULK_CS_WRAP_LEN 13
152 #define US_BULK_CS_SIGN 0x53425355 /* spells out 'USBS' */
153 #define US_BULK_STAT_OK 0
154 #define US_BULK_STAT_FAIL 1
155 #define US_BULK_STAT_PHASE 2
156
157 /* bulk-only class specific requests */
158 #define US_BULK_RESET_REQUEST 0xff
159 #define US_BULK_GET_MAX_LUN 0xfe
160
161 /*
162 */
163 struct ub_dev;
164
165 #define UB_MAX_REQ_SG 9 /* cdrecord requires 32KB and maybe a header */
166 #define UB_MAX_SECTORS 64
167
168 /*
169 * A second is more than enough for a 32K transfer (UB_MAX_SECTORS)
170 * even if a webcam hogs the bus, but some devices need time to spin up.
171 */
172 #define UB_URB_TIMEOUT (HZ*2)
173 #define UB_DATA_TIMEOUT (HZ*5) /* ZIP does spin-ups in the data phase */
174 #define UB_STAT_TIMEOUT (HZ*5) /* Same spinups and eject for a dataless cmd. */
175 #define UB_CTRL_TIMEOUT (HZ/2) /* 500ms ought to be enough to clear a stall */
176
177 /*
178 * An instance of a SCSI command in transit.
179 */
180 #define UB_DIR_NONE 0
181 #define UB_DIR_READ 1
182 #define UB_DIR_ILLEGAL2 2
183 #define UB_DIR_WRITE 3
184
185 #define UB_DIR_CHAR(c) (((c)==UB_DIR_WRITE)? 'w': \
186 (((c)==UB_DIR_READ)? 'r': 'n'))
187
188 enum ub_scsi_cmd_state {
189 UB_CMDST_INIT, /* Initial state */
190 UB_CMDST_CMD, /* Command submitted */
191 UB_CMDST_DATA, /* Data phase */
192 UB_CMDST_CLR2STS, /* Clearing before requesting status */
193 UB_CMDST_STAT, /* Status phase */
194 UB_CMDST_CLEAR, /* Clearing a stall (halt, actually) */
195 UB_CMDST_CLRRS, /* Clearing before retrying status */
196 UB_CMDST_SENSE, /* Sending Request Sense */
197 UB_CMDST_DONE /* Final state */
198 };
199
200 static char *ub_scsi_cmd_stname[] = {
201 ". ",
202 "Cmd",
203 "dat",
204 "c2s",
205 "sts",
206 "clr",
207 "crs",
208 "Sen",
209 "fin"
210 };
211
212 struct ub_scsi_cmd {
213 unsigned char cdb[UB_MAX_CDB_SIZE];
214 unsigned char cdb_len;
215
216 unsigned char dir; /* 0 - none, 1 - read, 3 - write. */
217 unsigned char trace_index;
218 enum ub_scsi_cmd_state state;
219 unsigned int tag;
220 struct ub_scsi_cmd *next;
221
222 int error; /* Return code - valid upon done */
223 unsigned int act_len; /* Return size */
224 unsigned char key, asc, ascq; /* May be valid if error==-EIO */
225
226 int stat_count; /* Retries getting status. */
227
228 unsigned int len; /* Requested length */
229 unsigned int current_sg;
230 unsigned int nsg; /* sgv[nsg] */
231 struct scatterlist sgv[UB_MAX_REQ_SG];
232
233 struct ub_lun *lun;
234 void (*done)(struct ub_dev *, struct ub_scsi_cmd *);
235 void *back;
236 };
237
238 struct ub_request {
239 struct request *rq;
240 unsigned int current_try;
241 unsigned int nsg; /* sgv[nsg] */
242 struct scatterlist sgv[UB_MAX_REQ_SG];
243 };
244
245 /*
246 */
247 struct ub_capacity {
248 unsigned long nsec; /* Linux size - 512 byte sectors */
249 unsigned int bsize; /* Linux hardsect_size */
250 unsigned int bshift; /* Shift between 512 and hard sects */
251 };
252
253 /*
254 * The SCSI command tracing structure.
255 */
256
257 #define SCMD_ST_HIST_SZ 8
258 #define SCMD_TRACE_SZ 63 /* Less than 4KB of 61-byte lines */
259
260 struct ub_scsi_cmd_trace {
261 int hcur;
262 unsigned int tag;
263 unsigned int req_size, act_size;
264 unsigned char op;
265 unsigned char dir;
266 unsigned char key, asc, ascq;
267 char st_hst[SCMD_ST_HIST_SZ];
268 };
269
270 struct ub_scsi_trace {
271 int cur;
272 struct ub_scsi_cmd_trace vec[SCMD_TRACE_SZ];
273 };
274
275 /*
276 * This is a direct take-off from linux/include/completion.h
277 * The difference is that I do not wait on this thing, just poll.
278 * When I want to wait (ub_probe), I just use the stock completion.
279 *
280 * Note that INIT_COMPLETION takes no lock. It is correct. But why
281 * in the bloody hell that thing takes struct instead of pointer to struct
282 * is quite beyond me. I just copied it from the stock completion.
283 */
284 struct ub_completion {
285 unsigned int done;
286 spinlock_t lock;
287 };
288
289 static inline void ub_init_completion(struct ub_completion *x)
290 {
291 x->done = 0;
292 spin_lock_init(&x->lock);
293 }
294
295 #define UB_INIT_COMPLETION(x) ((x).done = 0)
296
297 static void ub_complete(struct ub_completion *x)
298 {
299 unsigned long flags;
300
301 spin_lock_irqsave(&x->lock, flags);
302 x->done++;
303 spin_unlock_irqrestore(&x->lock, flags);
304 }
305
306 static int ub_is_completed(struct ub_completion *x)
307 {
308 unsigned long flags;
309 int ret;
310
311 spin_lock_irqsave(&x->lock, flags);
312 ret = x->done;
313 spin_unlock_irqrestore(&x->lock, flags);
314 return ret;
315 }
316
317 /*
318 */
319 struct ub_scsi_cmd_queue {
320 int qlen, qmax;
321 struct ub_scsi_cmd *head, *tail;
322 };
323
324 /*
325 * The block device instance (one per LUN).
326 */
327 struct ub_lun {
328 struct ub_dev *udev;
329 struct list_head link;
330 struct gendisk *disk;
331 int id; /* Host index */
332 int num; /* LUN number */
333 char name[16];
334
335 int changed; /* Media was changed */
336 int removable;
337 int readonly;
338 int first_open; /* Kludge. See ub_bd_open. */
339
340 struct ub_request urq;
341
342 /* Use Ingo's mempool if or when we have more than one command. */
343 /*
344 * Currently we never need more than one command for the whole device.
345 * However, giving every LUN a command is a cheap and automatic way
346 * to enforce fairness between them.
347 */
348 int cmda[1];
349 struct ub_scsi_cmd cmdv[1];
350
351 struct ub_capacity capacity;
352 };
353
354 /*
355 * The USB device instance.
356 */
357 struct ub_dev {
358 spinlock_t lock;
359 atomic_t poison; /* The USB device is disconnected */
360 int openc; /* protected by ub_lock! */
361 /* kref is too implicit for our taste */
362 int reset; /* Reset is running */
363 unsigned int tagcnt;
364 char name[12];
365 struct usb_device *dev;
366 struct usb_interface *intf;
367
368 struct list_head luns;
369
370 unsigned int send_bulk_pipe; /* cached pipe values */
371 unsigned int recv_bulk_pipe;
372 unsigned int send_ctrl_pipe;
373 unsigned int recv_ctrl_pipe;
374
375 struct tasklet_struct tasklet;
376
377 struct ub_scsi_cmd_queue cmd_queue;
378 struct ub_scsi_cmd top_rqs_cmd; /* REQUEST SENSE */
379 unsigned char top_sense[UB_SENSE_SIZE];
380
381 struct ub_completion work_done;
382 struct urb work_urb;
383 struct timer_list work_timer;
384 int last_pipe; /* What might need clearing */
385 __le32 signature; /* Learned signature */
386 struct bulk_cb_wrap work_bcb;
387 struct bulk_cs_wrap work_bcs;
388 struct usb_ctrlrequest work_cr;
389
390 struct work_struct reset_work;
391 wait_queue_head_t reset_wait;
392
393 int sg_stat[6];
394 struct ub_scsi_trace tr;
395 };
396
397 /*
398 */
399 static void ub_cleanup(struct ub_dev *sc);
400 static int ub_request_fn_1(struct ub_lun *lun, struct request *rq);
401 static void ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
402 struct ub_scsi_cmd *cmd, struct ub_request *urq);
403 static void ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
404 struct ub_scsi_cmd *cmd, struct ub_request *urq);
405 static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
406 static void ub_end_rq(struct request *rq, int uptodate);
407 static int ub_rw_cmd_retry(struct ub_dev *sc, struct ub_lun *lun,
408 struct ub_request *urq, struct ub_scsi_cmd *cmd);
409 static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
410 static void ub_urb_complete(struct urb *urb, struct pt_regs *pt);
411 static void ub_scsi_action(unsigned long _dev);
412 static void ub_scsi_dispatch(struct ub_dev *sc);
413 static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
414 static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
415 static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc);
416 static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
417 static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
418 static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
419 static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
420 static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
421 int stalled_pipe);
422 static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd);
423 static void ub_reset_enter(struct ub_dev *sc);
424 static void ub_reset_task(void *arg);
425 static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun);
426 static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
427 struct ub_capacity *ret);
428 static int ub_probe_lun(struct ub_dev *sc, int lnum);
429
430 /*
431 */
432 #ifdef CONFIG_USB_LIBUSUAL
433
434 #define ub_usb_ids storage_usb_ids
435 #else
436
437 static struct usb_device_id ub_usb_ids[] = {
438 { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, US_SC_SCSI, US_PR_BULK) },
439 { }
440 };
441
442 MODULE_DEVICE_TABLE(usb, ub_usb_ids);
443 #endif /* CONFIG_USB_LIBUSUAL */
444
445 /*
446 * Find me a way to identify "next free minor" for add_disk(),
447 * and the array disappears the next day. However, the number of
448 * hosts has something to do with the naming and /proc/partitions.
449 * This has to be thought out in detail before changing.
450 * If UB_MAX_HOST was 1000, we'd use a bitmap. Or a better data structure.
451 */
452 #define UB_MAX_HOSTS 26
453 static char ub_hostv[UB_MAX_HOSTS];
454
455 static DEFINE_SPINLOCK(ub_lock); /* Locks globals and ->openc */
456
457 /*
458 * The SCSI command tracing procedures.
459 */
460
461 static void ub_cmdtr_new(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
462 {
463 int n;
464 struct ub_scsi_cmd_trace *t;
465
466 if ((n = sc->tr.cur + 1) == SCMD_TRACE_SZ) n = 0;
467 t = &sc->tr.vec[n];
468
469 memset(t, 0, sizeof(struct ub_scsi_cmd_trace));
470 t->tag = cmd->tag;
471 t->op = cmd->cdb[0];
472 t->dir = cmd->dir;
473 t->req_size = cmd->len;
474 t->st_hst[0] = cmd->state;
475
476 sc->tr.cur = n;
477 cmd->trace_index = n;
478 }
479
480 static void ub_cmdtr_state(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
481 {
482 int n;
483 struct ub_scsi_cmd_trace *t;
484
485 t = &sc->tr.vec[cmd->trace_index];
486 if (t->tag == cmd->tag) {
487 if ((n = t->hcur + 1) == SCMD_ST_HIST_SZ) n = 0;
488 t->st_hst[n] = cmd->state;
489 t->hcur = n;
490 }
491 }
492
493 static void ub_cmdtr_act_len(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
494 {
495 struct ub_scsi_cmd_trace *t;
496
497 t = &sc->tr.vec[cmd->trace_index];
498 if (t->tag == cmd->tag)
499 t->act_size = cmd->act_len;
500 }
501
502 static void ub_cmdtr_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
503 unsigned char *sense)
504 {
505 struct ub_scsi_cmd_trace *t;
506
507 t = &sc->tr.vec[cmd->trace_index];
508 if (t->tag == cmd->tag) {
509 t->key = sense[2] & 0x0F;
510 t->asc = sense[12];
511 t->ascq = sense[13];
512 }
513 }
514
515 static ssize_t ub_diag_show(struct device *dev, struct device_attribute *attr,
516 char *page)
517 {
518 struct usb_interface *intf;
519 struct ub_dev *sc;
520 struct list_head *p;
521 struct ub_lun *lun;
522 int cnt;
523 unsigned long flags;
524 int nc, nh;
525 int i, j;
526 struct ub_scsi_cmd_trace *t;
527
528 intf = to_usb_interface(dev);
529 sc = usb_get_intfdata(intf);
530 if (sc == NULL)
531 return 0;
532
533 cnt = 0;
534 spin_lock_irqsave(&sc->lock, flags);
535
536 cnt += sprintf(page + cnt,
537 "poison %d reset %d\n",
538 atomic_read(&sc->poison), sc->reset);
539 cnt += sprintf(page + cnt,
540 "qlen %d qmax %d\n",
541 sc->cmd_queue.qlen, sc->cmd_queue.qmax);
542 cnt += sprintf(page + cnt,
543 "sg %d %d %d %d %d .. %d\n",
544 sc->sg_stat[0],
545 sc->sg_stat[1],
546 sc->sg_stat[2],
547 sc->sg_stat[3],
548 sc->sg_stat[4],
549 sc->sg_stat[5]);
550
551 list_for_each (p, &sc->luns) {
552 lun = list_entry(p, struct ub_lun, link);
553 cnt += sprintf(page + cnt,
554 "lun %u changed %d removable %d readonly %d\n",
555 lun->num, lun->changed, lun->removable, lun->readonly);
556 }
557
558 if ((nc = sc->tr.cur + 1) == SCMD_TRACE_SZ) nc = 0;
559 for (j = 0; j < SCMD_TRACE_SZ; j++) {
560 t = &sc->tr.vec[nc];
561
562 cnt += sprintf(page + cnt, "%08x %02x", t->tag, t->op);
563 if (t->op == REQUEST_SENSE) {
564 cnt += sprintf(page + cnt, " [sense %x %02x %02x]",
565 t->key, t->asc, t->ascq);
566 } else {
567 cnt += sprintf(page + cnt, " %c", UB_DIR_CHAR(t->dir));
568 cnt += sprintf(page + cnt, " [%5d %5d]",
569 t->req_size, t->act_size);
570 }
571 if ((nh = t->hcur + 1) == SCMD_ST_HIST_SZ) nh = 0;
572 for (i = 0; i < SCMD_ST_HIST_SZ; i++) {
573 cnt += sprintf(page + cnt, " %s",
574 ub_scsi_cmd_stname[(int)t->st_hst[nh]]);
575 if (++nh == SCMD_ST_HIST_SZ) nh = 0;
576 }
577 cnt += sprintf(page + cnt, "\n");
578
579 if (++nc == SCMD_TRACE_SZ) nc = 0;
580 }
581
582 spin_unlock_irqrestore(&sc->lock, flags);
583 return cnt;
584 }
585
586 static DEVICE_ATTR(diag, S_IRUGO, ub_diag_show, NULL); /* N.B. World readable */
587
588 /*
589 * The id allocator.
590 *
591 * This also stores the host for indexing by minor, which is somewhat dirty.
592 */
593 static int ub_id_get(void)
594 {
595 unsigned long flags;
596 int i;
597
598 spin_lock_irqsave(&ub_lock, flags);
599 for (i = 0; i < UB_MAX_HOSTS; i++) {
600 if (ub_hostv[i] == 0) {
601 ub_hostv[i] = 1;
602 spin_unlock_irqrestore(&ub_lock, flags);
603 return i;
604 }
605 }
606 spin_unlock_irqrestore(&ub_lock, flags);
607 return -1;
608 }
609
610 static void ub_id_put(int id)
611 {
612 unsigned long flags;
613
614 if (id < 0 || id >= UB_MAX_HOSTS) {
615 printk(KERN_ERR DRV_NAME ": bad host ID %d\n", id);
616 return;
617 }
618
619 spin_lock_irqsave(&ub_lock, flags);
620 if (ub_hostv[id] == 0) {
621 spin_unlock_irqrestore(&ub_lock, flags);
622 printk(KERN_ERR DRV_NAME ": freeing free host ID %d\n", id);
623 return;
624 }
625 ub_hostv[id] = 0;
626 spin_unlock_irqrestore(&ub_lock, flags);
627 }
628
629 /*
630 * Downcount for deallocation. This rides on two assumptions:
631 * - once something is poisoned, its refcount cannot grow
632 * - opens cannot happen at this time (del_gendisk was done)
633 * If the above is true, we can drop the lock, which we need for
634 * blk_cleanup_queue(): the silly thing may attempt to sleep.
635 * [Actually, it never needs to sleep for us, but it calls might_sleep()]
636 */
637 static void ub_put(struct ub_dev *sc)
638 {
639 unsigned long flags;
640
641 spin_lock_irqsave(&ub_lock, flags);
642 --sc->openc;
643 if (sc->openc == 0 && atomic_read(&sc->poison)) {
644 spin_unlock_irqrestore(&ub_lock, flags);
645 ub_cleanup(sc);
646 } else {
647 spin_unlock_irqrestore(&ub_lock, flags);
648 }
649 }
650
651 /*
652 * Final cleanup and deallocation.
653 */
654 static void ub_cleanup(struct ub_dev *sc)
655 {
656 struct list_head *p;
657 struct ub_lun *lun;
658 request_queue_t *q;
659
660 while (!list_empty(&sc->luns)) {
661 p = sc->luns.next;
662 lun = list_entry(p, struct ub_lun, link);
663 list_del(p);
664
665 /* I don't think queue can be NULL. But... Stolen from sx8.c */
666 if ((q = lun->disk->queue) != NULL)
667 blk_cleanup_queue(q);
668 /*
669 * If we zero disk->private_data BEFORE put_disk, we have
670 * to check for NULL all over the place in open, release,
671 * check_media and revalidate, because the block level
672 * semaphore is well inside the put_disk.
673 * But we cannot zero after the call, because *disk is gone.
674 * The sd.c is blatantly racy in this area.
675 */
676 /* disk->private_data = NULL; */
677 put_disk(lun->disk);
678 lun->disk = NULL;
679
680 ub_id_put(lun->id);
681 kfree(lun);
682 }
683
684 kfree(sc);
685 }
686
687 /*
688 * The "command allocator".
689 */
690 static struct ub_scsi_cmd *ub_get_cmd(struct ub_lun *lun)
691 {
692 struct ub_scsi_cmd *ret;
693
694 if (lun->cmda[0])
695 return NULL;
696 ret = &lun->cmdv[0];
697 lun->cmda[0] = 1;
698 return ret;
699 }
700
701 static void ub_put_cmd(struct ub_lun *lun, struct ub_scsi_cmd *cmd)
702 {
703 if (cmd != &lun->cmdv[0]) {
704 printk(KERN_WARNING "%s: releasing a foreign cmd %p\n",
705 lun->name, cmd);
706 return;
707 }
708 if (!lun->cmda[0]) {
709 printk(KERN_WARNING "%s: releasing a free cmd\n", lun->name);
710 return;
711 }
712 lun->cmda[0] = 0;
713 }
714
715 /*
716 * The command queue.
717 */
718 static void ub_cmdq_add(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
719 {
720 struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
721
722 if (t->qlen++ == 0) {
723 t->head = cmd;
724 t->tail = cmd;
725 } else {
726 t->tail->next = cmd;
727 t->tail = cmd;
728 }
729
730 if (t->qlen > t->qmax)
731 t->qmax = t->qlen;
732 }
733
734 static void ub_cmdq_insert(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
735 {
736 struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
737
738 if (t->qlen++ == 0) {
739 t->head = cmd;
740 t->tail = cmd;
741 } else {
742 cmd->next = t->head;
743 t->head = cmd;
744 }
745
746 if (t->qlen > t->qmax)
747 t->qmax = t->qlen;
748 }
749
750 static struct ub_scsi_cmd *ub_cmdq_pop(struct ub_dev *sc)
751 {
752 struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
753 struct ub_scsi_cmd *cmd;
754
755 if (t->qlen == 0)
756 return NULL;
757 if (--t->qlen == 0)
758 t->tail = NULL;
759 cmd = t->head;
760 t->head = cmd->next;
761 cmd->next = NULL;
762 return cmd;
763 }
764
765 #define ub_cmdq_peek(sc) ((sc)->cmd_queue.head)
766
767 /*
768 * The request function is our main entry point
769 */
770
771 static void ub_request_fn(request_queue_t *q)
772 {
773 struct ub_lun *lun = q->queuedata;
774 struct request *rq;
775
776 while ((rq = elv_next_request(q)) != NULL) {
777 if (ub_request_fn_1(lun, rq) != 0) {
778 blk_stop_queue(q);
779 break;
780 }
781 }
782 }
783
784 static int ub_request_fn_1(struct ub_lun *lun, struct request *rq)
785 {
786 struct ub_dev *sc = lun->udev;
787 struct ub_scsi_cmd *cmd;
788 struct ub_request *urq;
789 int n_elem;
790
791 if (atomic_read(&sc->poison) || lun->changed) {
792 blkdev_dequeue_request(rq);
793 ub_end_rq(rq, 0);
794 return 0;
795 }
796
797 if (lun->urq.rq != NULL)
798 return -1;
799 if ((cmd = ub_get_cmd(lun)) == NULL)
800 return -1;
801 memset(cmd, 0, sizeof(struct ub_scsi_cmd));
802
803 blkdev_dequeue_request(rq);
804
805 urq = &lun->urq;
806 memset(urq, 0, sizeof(struct ub_request));
807 urq->rq = rq;
808
809 /*
810 * get scatterlist from block layer
811 */
812 n_elem = blk_rq_map_sg(lun->disk->queue, rq, &urq->sgv[0]);
813 if (n_elem < 0) {
814 printk(KERN_INFO "%s: failed request map (%d)\n",
815 lun->name, n_elem); /* P3 */
816 goto drop;
817 }
818 if (n_elem > UB_MAX_REQ_SG) { /* Paranoia */
819 printk(KERN_WARNING "%s: request with %d segments\n",
820 lun->name, n_elem);
821 goto drop;
822 }
823 urq->nsg = n_elem;
824 sc->sg_stat[n_elem < 5 ? n_elem : 5]++;
825
826 if (blk_pc_request(rq)) {
827 ub_cmd_build_packet(sc, lun, cmd, urq);
828 } else {
829 ub_cmd_build_block(sc, lun, cmd, urq);
830 }
831 cmd->state = UB_CMDST_INIT;
832 cmd->lun = lun;
833 cmd->done = ub_rw_cmd_done;
834 cmd->back = urq;
835
836 cmd->tag = sc->tagcnt++;
837 if (ub_submit_scsi(sc, cmd) != 0)
838 goto drop;
839
840 return 0;
841
842 drop:
843 ub_put_cmd(lun, cmd);
844 ub_end_rq(rq, 0);
845 return 0;
846 }
847
848 static void ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
849 struct ub_scsi_cmd *cmd, struct ub_request *urq)
850 {
851 struct request *rq = urq->rq;
852 unsigned int block, nblks;
853
854 if (rq_data_dir(rq) == WRITE)
855 cmd->dir = UB_DIR_WRITE;
856 else
857 cmd->dir = UB_DIR_READ;
858
859 cmd->nsg = urq->nsg;
860 memcpy(cmd->sgv, urq->sgv, sizeof(struct scatterlist) * cmd->nsg);
861
862 /*
863 * build the command
864 *
865 * The call to blk_queue_hardsect_size() guarantees that request
866 * is aligned, but it is given in terms of 512 byte units, always.
867 */
868 block = rq->sector >> lun->capacity.bshift;
869 nblks = rq->nr_sectors >> lun->capacity.bshift;
870
871 cmd->cdb[0] = (cmd->dir == UB_DIR_READ)? READ_10: WRITE_10;
872 /* 10-byte uses 4 bytes of LBA: 2147483648KB, 2097152MB, 2048GB */
873 cmd->cdb[2] = block >> 24;
874 cmd->cdb[3] = block >> 16;
875 cmd->cdb[4] = block >> 8;
876 cmd->cdb[5] = block;
877 cmd->cdb[7] = nblks >> 8;
878 cmd->cdb[8] = nblks;
879 cmd->cdb_len = 10;
880
881 cmd->len = rq->nr_sectors * 512;
882 }
883
884 static void ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
885 struct ub_scsi_cmd *cmd, struct ub_request *urq)
886 {
887 struct request *rq = urq->rq;
888
889 if (rq->data_len == 0) {
890 cmd->dir = UB_DIR_NONE;
891 } else {
892 if (rq_data_dir(rq) == WRITE)
893 cmd->dir = UB_DIR_WRITE;
894 else
895 cmd->dir = UB_DIR_READ;
896 }
897
898 cmd->nsg = urq->nsg;
899 memcpy(cmd->sgv, urq->sgv, sizeof(struct scatterlist) * cmd->nsg);
900
901 memcpy(&cmd->cdb, rq->cmd, rq->cmd_len);
902 cmd->cdb_len = rq->cmd_len;
903
904 cmd->len = rq->data_len;
905 }
906
907 static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
908 {
909 struct ub_lun *lun = cmd->lun;
910 struct ub_request *urq = cmd->back;
911 struct request *rq;
912 int uptodate;
913
914 rq = urq->rq;
915
916 if (cmd->error == 0) {
917 uptodate = 1;
918
919 if (blk_pc_request(rq)) {
920 if (cmd->act_len >= rq->data_len)
921 rq->data_len = 0;
922 else
923 rq->data_len -= cmd->act_len;
924 }
925 } else {
926 uptodate = 0;
927
928 if (blk_pc_request(rq)) {
929 /* UB_SENSE_SIZE is smaller than SCSI_SENSE_BUFFERSIZE */
930 memcpy(rq->sense, sc->top_sense, UB_SENSE_SIZE);
931 rq->sense_len = UB_SENSE_SIZE;
932 if (sc->top_sense[0] != 0)
933 rq->errors = SAM_STAT_CHECK_CONDITION;
934 else
935 rq->errors = DID_ERROR << 16;
936 } else {
937 if (cmd->error == -EIO) {
938 if (ub_rw_cmd_retry(sc, lun, urq, cmd) == 0)
939 return;
940 }
941 }
942 }
943
944 urq->rq = NULL;
945
946 ub_put_cmd(lun, cmd);
947 ub_end_rq(rq, uptodate);
948 blk_start_queue(lun->disk->queue);
949 }
950
951 static void ub_end_rq(struct request *rq, int uptodate)
952 {
953 end_that_request_first(rq, uptodate, rq->hard_nr_sectors);
954 end_that_request_last(rq, uptodate);
955 }
956
957 static int ub_rw_cmd_retry(struct ub_dev *sc, struct ub_lun *lun,
958 struct ub_request *urq, struct ub_scsi_cmd *cmd)
959 {
960
961 if (atomic_read(&sc->poison))
962 return -ENXIO;
963
964 ub_reset_enter(sc);
965
966 if (urq->current_try >= 3)
967 return -EIO;
968 urq->current_try++;
969 /* P3 */ printk("%s: dir %c len/act %d/%d "
970 "[sense %x %02x %02x] retry %d\n",
971 sc->name, UB_DIR_CHAR(cmd->dir), cmd->len, cmd->act_len,
972 cmd->key, cmd->asc, cmd->ascq, urq->current_try);
973
974 memset(cmd, 0, sizeof(struct ub_scsi_cmd));
975 ub_cmd_build_block(sc, lun, cmd, urq);
976
977 cmd->state = UB_CMDST_INIT;
978 cmd->lun = lun;
979 cmd->done = ub_rw_cmd_done;
980 cmd->back = urq;
981
982 cmd->tag = sc->tagcnt++;
983
984 #if 0 /* Wasteful */
985 return ub_submit_scsi(sc, cmd);
986 #else
987 ub_cmdq_add(sc, cmd);
988 return 0;
989 #endif
990 }
991
992 /*
993 * Submit a regular SCSI operation (not an auto-sense).
994 *
995 * The Iron Law of Good Submit Routine is:
996 * Zero return - callback is done, Nonzero return - callback is not done.
997 * No exceptions.
998 *
999 * Host is assumed locked.
1000 *
1001 * XXX We only support Bulk for the moment.
1002 */
1003 static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1004 {
1005
1006 if (cmd->state != UB_CMDST_INIT ||
1007 (cmd->dir != UB_DIR_NONE && cmd->len == 0)) {
1008 return -EINVAL;
1009 }
1010
1011 ub_cmdq_add(sc, cmd);
1012 /*
1013 * We can call ub_scsi_dispatch(sc) right away here, but it's a little
1014 * safer to jump to a tasklet, in case upper layers do something silly.
1015 */
1016 tasklet_schedule(&sc->tasklet);
1017 return 0;
1018 }
1019
1020 /*
1021 * Submit the first URB for the queued command.
1022 * This function does not deal with queueing in any way.
1023 */
1024 static int ub_scsi_cmd_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1025 {
1026 struct bulk_cb_wrap *bcb;
1027 int rc;
1028
1029 bcb = &sc->work_bcb;
1030
1031 /*
1032 * ``If the allocation length is eighteen or greater, and a device
1033 * server returns less than eithteen bytes of data, the application
1034 * client should assume that the bytes not transferred would have been
1035 * zeroes had the device server returned those bytes.''
1036 *
1037 * We zero sense for all commands so that when a packet request
1038 * fails it does not return a stale sense.
1039 */
1040 memset(&sc->top_sense, 0, UB_SENSE_SIZE);
1041
1042 /* set up the command wrapper */
1043 bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
1044 bcb->Tag = cmd->tag; /* Endianness is not important */
1045 bcb->DataTransferLength = cpu_to_le32(cmd->len);
1046 bcb->Flags = (cmd->dir == UB_DIR_READ) ? 0x80 : 0;
1047 bcb->Lun = (cmd->lun != NULL) ? cmd->lun->num : 0;
1048 bcb->Length = cmd->cdb_len;
1049
1050 /* copy the command payload */
1051 memcpy(bcb->CDB, cmd->cdb, UB_MAX_CDB_SIZE);
1052
1053 UB_INIT_COMPLETION(sc->work_done);
1054
1055 sc->last_pipe = sc->send_bulk_pipe;
1056 usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->send_bulk_pipe,
1057 bcb, US_BULK_CB_WRAP_LEN, ub_urb_complete, sc);
1058
1059 /* Fill what we shouldn't be filling, because usb-storage did so. */
1060 sc->work_urb.actual_length = 0;
1061 sc->work_urb.error_count = 0;
1062 sc->work_urb.status = 0;
1063
1064 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1065 /* XXX Clear stalls */
1066 ub_complete(&sc->work_done);
1067 return rc;
1068 }
1069
1070 sc->work_timer.expires = jiffies + UB_URB_TIMEOUT;
1071 add_timer(&sc->work_timer);
1072
1073 cmd->state = UB_CMDST_CMD;
1074 ub_cmdtr_state(sc, cmd);
1075 return 0;
1076 }
1077
1078 /*
1079 * Timeout handler.
1080 */
1081 static void ub_urb_timeout(unsigned long arg)
1082 {
1083 struct ub_dev *sc = (struct ub_dev *) arg;
1084 unsigned long flags;
1085
1086 spin_lock_irqsave(&sc->lock, flags);
1087 usb_unlink_urb(&sc->work_urb);
1088 spin_unlock_irqrestore(&sc->lock, flags);
1089 }
1090
1091 /*
1092 * Completion routine for the work URB.
1093 *
1094 * This can be called directly from usb_submit_urb (while we have
1095 * the sc->lock taken) and from an interrupt (while we do NOT have
1096 * the sc->lock taken). Therefore, bounce this off to a tasklet.
1097 */
1098 static void ub_urb_complete(struct urb *urb, struct pt_regs *pt)
1099 {
1100 struct ub_dev *sc = urb->context;
1101
1102 ub_complete(&sc->work_done);
1103 tasklet_schedule(&sc->tasklet);
1104 }
1105
1106 static void ub_scsi_action(unsigned long _dev)
1107 {
1108 struct ub_dev *sc = (struct ub_dev *) _dev;
1109 unsigned long flags;
1110
1111 spin_lock_irqsave(&sc->lock, flags);
1112 del_timer(&sc->work_timer);
1113 ub_scsi_dispatch(sc);
1114 spin_unlock_irqrestore(&sc->lock, flags);
1115 }
1116
1117 static void ub_scsi_dispatch(struct ub_dev *sc)
1118 {
1119 struct ub_scsi_cmd *cmd;
1120 int rc;
1121
1122 while (!sc->reset && (cmd = ub_cmdq_peek(sc)) != NULL) {
1123 if (cmd->state == UB_CMDST_DONE) {
1124 ub_cmdq_pop(sc);
1125 (*cmd->done)(sc, cmd);
1126 } else if (cmd->state == UB_CMDST_INIT) {
1127 ub_cmdtr_new(sc, cmd);
1128 if ((rc = ub_scsi_cmd_start(sc, cmd)) == 0)
1129 break;
1130 cmd->error = rc;
1131 cmd->state = UB_CMDST_DONE;
1132 ub_cmdtr_state(sc, cmd);
1133 } else {
1134 if (!ub_is_completed(&sc->work_done))
1135 break;
1136 ub_scsi_urb_compl(sc, cmd);
1137 }
1138 }
1139 }
1140
1141 static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1142 {
1143 struct urb *urb = &sc->work_urb;
1144 struct bulk_cs_wrap *bcs;
1145 int len;
1146 int rc;
1147
1148 if (atomic_read(&sc->poison)) {
1149 ub_state_done(sc, cmd, -ENODEV);
1150 return;
1151 }
1152
1153 if (cmd->state == UB_CMDST_CLEAR) {
1154 if (urb->status == -EPIPE) {
1155 /*
1156 * STALL while clearning STALL.
1157 * The control pipe clears itself - nothing to do.
1158 */
1159 printk(KERN_NOTICE "%s: stall on control pipe\n",
1160 sc->name);
1161 goto Bad_End;
1162 }
1163
1164 /*
1165 * We ignore the result for the halt clear.
1166 */
1167
1168 /* reset the endpoint toggle */
1169 usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
1170 usb_pipeout(sc->last_pipe), 0);
1171
1172 ub_state_sense(sc, cmd);
1173
1174 } else if (cmd->state == UB_CMDST_CLR2STS) {
1175 if (urb->status == -EPIPE) {
1176 printk(KERN_NOTICE "%s: stall on control pipe\n",
1177 sc->name);
1178 goto Bad_End;
1179 }
1180
1181 /*
1182 * We ignore the result for the halt clear.
1183 */
1184
1185 /* reset the endpoint toggle */
1186 usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
1187 usb_pipeout(sc->last_pipe), 0);
1188
1189 ub_state_stat(sc, cmd);
1190
1191 } else if (cmd->state == UB_CMDST_CLRRS) {
1192 if (urb->status == -EPIPE) {
1193 printk(KERN_NOTICE "%s: stall on control pipe\n",
1194 sc->name);
1195 goto Bad_End;
1196 }
1197
1198 /*
1199 * We ignore the result for the halt clear.
1200 */
1201
1202 /* reset the endpoint toggle */
1203 usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
1204 usb_pipeout(sc->last_pipe), 0);
1205
1206 ub_state_stat_counted(sc, cmd);
1207
1208 } else if (cmd->state == UB_CMDST_CMD) {
1209 switch (urb->status) {
1210 case 0:
1211 break;
1212 case -EOVERFLOW:
1213 goto Bad_End;
1214 case -EPIPE:
1215 rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1216 if (rc != 0) {
1217 printk(KERN_NOTICE "%s: "
1218 "unable to submit clear (%d)\n",
1219 sc->name, rc);
1220 /*
1221 * This is typically ENOMEM or some other such shit.
1222 * Retrying is pointless. Just do Bad End on it...
1223 */
1224 ub_state_done(sc, cmd, rc);
1225 return;
1226 }
1227 cmd->state = UB_CMDST_CLEAR;
1228 ub_cmdtr_state(sc, cmd);
1229 return;
1230 case -ESHUTDOWN: /* unplug */
1231 case -EILSEQ: /* unplug timeout on uhci */
1232 ub_state_done(sc, cmd, -ENODEV);
1233 return;
1234 default:
1235 goto Bad_End;
1236 }
1237 if (urb->actual_length != US_BULK_CB_WRAP_LEN) {
1238 goto Bad_End;
1239 }
1240
1241 if (cmd->dir == UB_DIR_NONE || cmd->nsg < 1) {
1242 ub_state_stat(sc, cmd);
1243 return;
1244 }
1245
1246 // udelay(125); // usb-storage has this
1247 ub_data_start(sc, cmd);
1248
1249 } else if (cmd->state == UB_CMDST_DATA) {
1250 if (urb->status == -EPIPE) {
1251 rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1252 if (rc != 0) {
1253 printk(KERN_NOTICE "%s: "
1254 "unable to submit clear (%d)\n",
1255 sc->name, rc);
1256 ub_state_done(sc, cmd, rc);
1257 return;
1258 }
1259 cmd->state = UB_CMDST_CLR2STS;
1260 ub_cmdtr_state(sc, cmd);
1261 return;
1262 }
1263 if (urb->status == -EOVERFLOW) {
1264 /*
1265 * A babble? Failure, but we must transfer CSW now.
1266 */
1267 cmd->error = -EOVERFLOW; /* A cheap trick... */
1268 ub_state_stat(sc, cmd);
1269 return;
1270 }
1271
1272 if (cmd->dir == UB_DIR_WRITE) {
1273 /*
1274 * Do not continue writes in case of a failure.
1275 * Doing so would cause sectors to be mixed up,
1276 * which is worse than sectors lost.
1277 *
1278 * We must try to read the CSW, or many devices
1279 * get confused.
1280 */
1281 len = urb->actual_length;
1282 if (urb->status != 0 ||
1283 len != cmd->sgv[cmd->current_sg].length) {
1284 cmd->act_len += len;
1285 ub_cmdtr_act_len(sc, cmd);
1286
1287 cmd->error = -EIO;
1288 ub_state_stat(sc, cmd);
1289 return;
1290 }
1291
1292 } else {
1293 /*
1294 * If an error occurs on read, we record it, and
1295 * continue to fetch data in order to avoid bubble.
1296 *
1297 * As a small shortcut, we stop if we detect that
1298 * a CSW mixed into data.
1299 */
1300 if (urb->status != 0)
1301 cmd->error = -EIO;
1302
1303 len = urb->actual_length;
1304 if (urb->status != 0 ||
1305 len != cmd->sgv[cmd->current_sg].length) {
1306 if ((len & 0x1FF) == US_BULK_CS_WRAP_LEN)
1307 goto Bad_End;
1308 }
1309 }
1310
1311 cmd->act_len += urb->actual_length;
1312 ub_cmdtr_act_len(sc, cmd);
1313
1314 if (++cmd->current_sg < cmd->nsg) {
1315 ub_data_start(sc, cmd);
1316 return;
1317 }
1318 ub_state_stat(sc, cmd);
1319
1320 } else if (cmd->state == UB_CMDST_STAT) {
1321 if (urb->status == -EPIPE) {
1322 rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1323 if (rc != 0) {
1324 printk(KERN_NOTICE "%s: "
1325 "unable to submit clear (%d)\n",
1326 sc->name, rc);
1327 ub_state_done(sc, cmd, rc);
1328 return;
1329 }
1330
1331 /*
1332 * Having a stall when getting CSW is an error, so
1333 * make sure uppper levels are not oblivious to it.
1334 */
1335 cmd->error = -EIO; /* A cheap trick... */
1336
1337 cmd->state = UB_CMDST_CLRRS;
1338 ub_cmdtr_state(sc, cmd);
1339 return;
1340 }
1341
1342 /* Catch everything, including -EOVERFLOW and other nasties. */
1343 if (urb->status != 0)
1344 goto Bad_End;
1345
1346 if (urb->actual_length == 0) {
1347 ub_state_stat_counted(sc, cmd);
1348 return;
1349 }
1350
1351 /*
1352 * Check the returned Bulk protocol status.
1353 * The status block has to be validated first.
1354 */
1355
1356 bcs = &sc->work_bcs;
1357
1358 if (sc->signature == cpu_to_le32(0)) {
1359 /*
1360 * This is the first reply, so do not perform the check.
1361 * Instead, remember the signature the device uses
1362 * for future checks. But do not allow a nul.
1363 */
1364 sc->signature = bcs->Signature;
1365 if (sc->signature == cpu_to_le32(0)) {
1366 ub_state_stat_counted(sc, cmd);
1367 return;
1368 }
1369 } else {
1370 if (bcs->Signature != sc->signature) {
1371 ub_state_stat_counted(sc, cmd);
1372 return;
1373 }
1374 }
1375
1376 if (bcs->Tag != cmd->tag) {
1377 /*
1378 * This usually happens when we disagree with the
1379 * device's microcode about something. For instance,
1380 * a few of them throw this after timeouts. They buffer
1381 * commands and reply at commands we timed out before.
1382 * Without flushing these replies we loop forever.
1383 */
1384 ub_state_stat_counted(sc, cmd);
1385 return;
1386 }
1387
1388 len = le32_to_cpu(bcs->Residue);
1389 if (len != cmd->len - cmd->act_len) {
1390 /*
1391 * It is all right to transfer less, the caller has
1392 * to check. But it's not all right if the device
1393 * counts disagree with our counts.
1394 */
1395 /* P3 */ printk("%s: resid %d len %d act %d\n",
1396 sc->name, len, cmd->len, cmd->act_len);
1397 goto Bad_End;
1398 }
1399
1400 switch (bcs->Status) {
1401 case US_BULK_STAT_OK:
1402 break;
1403 case US_BULK_STAT_FAIL:
1404 ub_state_sense(sc, cmd);
1405 return;
1406 case US_BULK_STAT_PHASE:
1407 /* P3 */ printk("%s: status PHASE\n", sc->name);
1408 goto Bad_End;
1409 default:
1410 printk(KERN_INFO "%s: unknown CSW status 0x%x\n",
1411 sc->name, bcs->Status);
1412 ub_state_done(sc, cmd, -EINVAL);
1413 return;
1414 }
1415
1416 /* Not zeroing error to preserve a babble indicator */
1417 if (cmd->error != 0) {
1418 ub_state_sense(sc, cmd);
1419 return;
1420 }
1421 cmd->state = UB_CMDST_DONE;
1422 ub_cmdtr_state(sc, cmd);
1423 ub_cmdq_pop(sc);
1424 (*cmd->done)(sc, cmd);
1425
1426 } else if (cmd->state == UB_CMDST_SENSE) {
1427 ub_state_done(sc, cmd, -EIO);
1428
1429 } else {
1430 printk(KERN_WARNING "%s: "
1431 "wrong command state %d\n",
1432 sc->name, cmd->state);
1433 ub_state_done(sc, cmd, -EINVAL);
1434 return;
1435 }
1436 return;
1437
1438 Bad_End: /* Little Excel is dead */
1439 ub_state_done(sc, cmd, -EIO);
1440 }
1441
1442 /*
1443 * Factorization helper for the command state machine:
1444 * Initiate a data segment transfer.
1445 */
1446 static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1447 {
1448 struct scatterlist *sg = &cmd->sgv[cmd->current_sg];
1449 int pipe;
1450 int rc;
1451
1452 UB_INIT_COMPLETION(sc->work_done);
1453
1454 if (cmd->dir == UB_DIR_READ)
1455 pipe = sc->recv_bulk_pipe;
1456 else
1457 pipe = sc->send_bulk_pipe;
1458 sc->last_pipe = pipe;
1459 usb_fill_bulk_urb(&sc->work_urb, sc->dev, pipe,
1460 page_address(sg->page) + sg->offset, sg->length,
1461 ub_urb_complete, sc);
1462 sc->work_urb.actual_length = 0;
1463 sc->work_urb.error_count = 0;
1464 sc->work_urb.status = 0;
1465
1466 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1467 /* XXX Clear stalls */
1468 ub_complete(&sc->work_done);
1469 ub_state_done(sc, cmd, rc);
1470 return;
1471 }
1472
1473 sc->work_timer.expires = jiffies + UB_DATA_TIMEOUT;
1474 add_timer(&sc->work_timer);
1475
1476 cmd->state = UB_CMDST_DATA;
1477 ub_cmdtr_state(sc, cmd);
1478 }
1479
1480 /*
1481 * Factorization helper for the command state machine:
1482 * Finish the command.
1483 */
1484 static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc)
1485 {
1486
1487 cmd->error = rc;
1488 cmd->state = UB_CMDST_DONE;
1489 ub_cmdtr_state(sc, cmd);
1490 ub_cmdq_pop(sc);
1491 (*cmd->done)(sc, cmd);
1492 }
1493
1494 /*
1495 * Factorization helper for the command state machine:
1496 * Submit a CSW read.
1497 */
1498 static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1499 {
1500 int rc;
1501
1502 UB_INIT_COMPLETION(sc->work_done);
1503
1504 sc->last_pipe = sc->recv_bulk_pipe;
1505 usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->recv_bulk_pipe,
1506 &sc->work_bcs, US_BULK_CS_WRAP_LEN, ub_urb_complete, sc);
1507 sc->work_urb.actual_length = 0;
1508 sc->work_urb.error_count = 0;
1509 sc->work_urb.status = 0;
1510
1511 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1512 /* XXX Clear stalls */
1513 ub_complete(&sc->work_done);
1514 ub_state_done(sc, cmd, rc);
1515 return -1;
1516 }
1517
1518 sc->work_timer.expires = jiffies + UB_STAT_TIMEOUT;
1519 add_timer(&sc->work_timer);
1520 return 0;
1521 }
1522
1523 /*
1524 * Factorization helper for the command state machine:
1525 * Submit a CSW read and go to STAT state.
1526 */
1527 static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1528 {
1529
1530 if (__ub_state_stat(sc, cmd) != 0)
1531 return;
1532
1533 cmd->stat_count = 0;
1534 cmd->state = UB_CMDST_STAT;
1535 ub_cmdtr_state(sc, cmd);
1536 }
1537
1538 /*
1539 * Factorization helper for the command state machine:
1540 * Submit a CSW read and go to STAT state with counter (along [C] path).
1541 */
1542 static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1543 {
1544
1545 if (++cmd->stat_count >= 4) {
1546 ub_state_sense(sc, cmd);
1547 return;
1548 }
1549
1550 if (__ub_state_stat(sc, cmd) != 0)
1551 return;
1552
1553 cmd->state = UB_CMDST_STAT;
1554 ub_cmdtr_state(sc, cmd);
1555 }
1556
1557 /*
1558 * Factorization helper for the command state machine:
1559 * Submit a REQUEST SENSE and go to SENSE state.
1560 */
1561 static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1562 {
1563 struct ub_scsi_cmd *scmd;
1564 struct scatterlist *sg;
1565 int rc;
1566
1567 if (cmd->cdb[0] == REQUEST_SENSE) {
1568 rc = -EPIPE;
1569 goto error;
1570 }
1571
1572 scmd = &sc->top_rqs_cmd;
1573 memset(scmd, 0, sizeof(struct ub_scsi_cmd));
1574 scmd->cdb[0] = REQUEST_SENSE;
1575 scmd->cdb[4] = UB_SENSE_SIZE;
1576 scmd->cdb_len = 6;
1577 scmd->dir = UB_DIR_READ;
1578 scmd->state = UB_CMDST_INIT;
1579 scmd->nsg = 1;
1580 sg = &scmd->sgv[0];
1581 sg->page = virt_to_page(sc->top_sense);
1582 sg->offset = (unsigned long)sc->top_sense & (PAGE_SIZE-1);
1583 sg->length = UB_SENSE_SIZE;
1584 scmd->len = UB_SENSE_SIZE;
1585 scmd->lun = cmd->lun;
1586 scmd->done = ub_top_sense_done;
1587 scmd->back = cmd;
1588
1589 scmd->tag = sc->tagcnt++;
1590
1591 cmd->state = UB_CMDST_SENSE;
1592 ub_cmdtr_state(sc, cmd);
1593
1594 ub_cmdq_insert(sc, scmd);
1595 return;
1596
1597 error:
1598 ub_state_done(sc, cmd, rc);
1599 }
1600
1601 /*
1602 * A helper for the command's state machine:
1603 * Submit a stall clear.
1604 */
1605 static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
1606 int stalled_pipe)
1607 {
1608 int endp;
1609 struct usb_ctrlrequest *cr;
1610 int rc;
1611
1612 endp = usb_pipeendpoint(stalled_pipe);
1613 if (usb_pipein (stalled_pipe))
1614 endp |= USB_DIR_IN;
1615
1616 cr = &sc->work_cr;
1617 cr->bRequestType = USB_RECIP_ENDPOINT;
1618 cr->bRequest = USB_REQ_CLEAR_FEATURE;
1619 cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
1620 cr->wIndex = cpu_to_le16(endp);
1621 cr->wLength = cpu_to_le16(0);
1622
1623 UB_INIT_COMPLETION(sc->work_done);
1624
1625 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
1626 (unsigned char*) cr, NULL, 0, ub_urb_complete, sc);
1627 sc->work_urb.actual_length = 0;
1628 sc->work_urb.error_count = 0;
1629 sc->work_urb.status = 0;
1630
1631 if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1632 ub_complete(&sc->work_done);
1633 return rc;
1634 }
1635
1636 sc->work_timer.expires = jiffies + UB_CTRL_TIMEOUT;
1637 add_timer(&sc->work_timer);
1638 return 0;
1639 }
1640
1641 /*
1642 */
1643 static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd)
1644 {
1645 unsigned char *sense = sc->top_sense;
1646 struct ub_scsi_cmd *cmd;
1647
1648 /*
1649 * Ignoring scmd->act_len, because the buffer was pre-zeroed.
1650 */
1651 ub_cmdtr_sense(sc, scmd, sense);
1652
1653 /*
1654 * Find the command which triggered the unit attention or a check,
1655 * save the sense into it, and advance its state machine.
1656 */
1657 if ((cmd = ub_cmdq_peek(sc)) == NULL) {
1658 printk(KERN_WARNING "%s: sense done while idle\n", sc->name);
1659 return;
1660 }
1661 if (cmd != scmd->back) {
1662 printk(KERN_WARNING "%s: "
1663 "sense done for wrong command 0x%x\n",
1664 sc->name, cmd->tag);
1665 return;
1666 }
1667 if (cmd->state != UB_CMDST_SENSE) {
1668 printk(KERN_WARNING "%s: "
1669 "sense done with bad cmd state %d\n",
1670 sc->name, cmd->state);
1671 return;
1672 }
1673
1674 cmd->key = sense[2] & 0x0F;
1675 cmd->asc = sense[12];
1676 cmd->ascq = sense[13];
1677
1678 ub_scsi_urb_compl(sc, cmd);
1679 }
1680
1681 /*
1682 * Reset management
1683 */
1684
1685 static void ub_reset_enter(struct ub_dev *sc)
1686 {
1687
1688 if (sc->reset) {
1689 /* This happens often on multi-LUN devices. */
1690 return;
1691 }
1692 sc->reset = 1;
1693
1694 #if 0 /* Not needed because the disconnect waits for us. */
1695 unsigned long flags;
1696 spin_lock_irqsave(&ub_lock, flags);
1697 sc->openc++;
1698 spin_unlock_irqrestore(&ub_lock, flags);
1699 #endif
1700
1701 #if 0 /* We let them stop themselves. */
1702 struct list_head *p;
1703 struct ub_lun *lun;
1704 list_for_each(p, &sc->luns) {
1705 lun = list_entry(p, struct ub_lun, link);
1706 blk_stop_queue(lun->disk->queue);
1707 }
1708 #endif
1709
1710 schedule_work(&sc->reset_work);
1711 }
1712
1713 static void ub_reset_task(void *arg)
1714 {
1715 struct ub_dev *sc = arg;
1716 unsigned long flags;
1717 struct list_head *p;
1718 struct ub_lun *lun;
1719 int lkr, rc;
1720
1721 if (!sc->reset) {
1722 printk(KERN_WARNING "%s: Running reset unrequested\n",
1723 sc->name);
1724 return;
1725 }
1726
1727 if (atomic_read(&sc->poison)) {
1728 printk(KERN_NOTICE "%s: Not resetting disconnected device\n",
1729 sc->name); /* P3 This floods. Remove soon. XXX */
1730 } else if (sc->dev->actconfig->desc.bNumInterfaces != 1) {
1731 printk(KERN_NOTICE "%s: Not resetting multi-interface device\n",
1732 sc->name); /* P3 This floods. Remove soon. XXX */
1733 } else {
1734 if ((lkr = usb_lock_device_for_reset(sc->dev, sc->intf)) < 0) {
1735 printk(KERN_NOTICE
1736 "%s: usb_lock_device_for_reset failed (%d)\n",
1737 sc->name, lkr);
1738 } else {
1739 rc = usb_reset_device(sc->dev);
1740 if (rc < 0) {
1741 printk(KERN_NOTICE "%s: "
1742 "usb_lock_device_for_reset failed (%d)\n",
1743 sc->name, rc);
1744 }
1745
1746 if (lkr)
1747 usb_unlock_device(sc->dev);
1748 }
1749 }
1750
1751 /*
1752 * In theory, no commands can be running while reset is active,
1753 * so nobody can ask for another reset, and so we do not need any
1754 * queues of resets or anything. We do need a spinlock though,
1755 * to interact with block layer.
1756 */
1757 spin_lock_irqsave(&sc->lock, flags);
1758 sc->reset = 0;
1759 tasklet_schedule(&sc->tasklet);
1760 list_for_each(p, &sc->luns) {
1761 lun = list_entry(p, struct ub_lun, link);
1762 blk_start_queue(lun->disk->queue);
1763 }
1764 wake_up(&sc->reset_wait);
1765 spin_unlock_irqrestore(&sc->lock, flags);
1766 }
1767
1768 /*
1769 * This is called from a process context.
1770 */
1771 static void ub_revalidate(struct ub_dev *sc, struct ub_lun *lun)
1772 {
1773
1774 lun->readonly = 0; /* XXX Query this from the device */
1775
1776 lun->capacity.nsec = 0;
1777 lun->capacity.bsize = 512;
1778 lun->capacity.bshift = 0;
1779
1780 if (ub_sync_tur(sc, lun) != 0)
1781 return; /* Not ready */
1782 lun->changed = 0;
1783
1784 if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
1785 /*
1786 * The retry here means something is wrong, either with the
1787 * device, with the transport, or with our code.
1788 * We keep this because sd.c has retries for capacity.
1789 */
1790 if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
1791 lun->capacity.nsec = 0;
1792 lun->capacity.bsize = 512;
1793 lun->capacity.bshift = 0;
1794 }
1795 }
1796 }
1797
1798 /*
1799 * The open funcion.
1800 * This is mostly needed to keep refcounting, but also to support
1801 * media checks on removable media drives.
1802 */
1803 static int ub_bd_open(struct inode *inode, struct file *filp)
1804 {
1805 struct gendisk *disk = inode->i_bdev->bd_disk;
1806 struct ub_lun *lun;
1807 struct ub_dev *sc;
1808 unsigned long flags;
1809 int rc;
1810
1811 if ((lun = disk->private_data) == NULL)
1812 return -ENXIO;
1813 sc = lun->udev;
1814
1815 spin_lock_irqsave(&ub_lock, flags);
1816 if (atomic_read(&sc->poison)) {
1817 spin_unlock_irqrestore(&ub_lock, flags);
1818 return -ENXIO;
1819 }
1820 sc->openc++;
1821 spin_unlock_irqrestore(&ub_lock, flags);
1822
1823 /*
1824 * This is a workaround for a specific problem in our block layer.
1825 * In 2.6.9, register_disk duplicates the code from rescan_partitions.
1826 * However, if we do add_disk with a device which persistently reports
1827 * a changed media, add_disk calls register_disk, which does do_open,
1828 * which will call rescan_paritions for changed media. After that,
1829 * register_disk attempts to do it all again and causes double kobject
1830 * registration and a eventually an oops on module removal.
1831 *
1832 * The bottom line is, Al Viro says that we should not allow
1833 * bdev->bd_invalidated to be set when doing add_disk no matter what.
1834 */
1835 if (lun->first_open) {
1836 lun->first_open = 0;
1837 if (lun->changed) {
1838 rc = -ENOMEDIUM;
1839 goto err_open;
1840 }
1841 }
1842
1843 if (lun->removable || lun->readonly)
1844 check_disk_change(inode->i_bdev);
1845
1846 /*
1847 * The sd.c considers ->media_present and ->changed not equivalent,
1848 * under some pretty murky conditions (a failure of READ CAPACITY).
1849 * We may need it one day.
1850 */
1851 if (lun->removable && lun->changed && !(filp->f_flags & O_NDELAY)) {
1852 rc = -ENOMEDIUM;
1853 goto err_open;
1854 }
1855
1856 if (lun->readonly && (filp->f_mode & FMODE_WRITE)) {
1857 rc = -EROFS;
1858 goto err_open;
1859 }
1860
1861 return 0;
1862
1863 err_open:
1864 ub_put(sc);
1865 return rc;
1866 }
1867
1868 /*
1869 */
1870 static int ub_bd_release(struct inode *inode, struct file *filp)
1871 {
1872 struct gendisk *disk = inode->i_bdev->bd_disk;
1873 struct ub_lun *lun = disk->private_data;
1874 struct ub_dev *sc = lun->udev;
1875
1876 ub_put(sc);
1877 return 0;
1878 }
1879
1880 /*
1881 * The ioctl interface.
1882 */
1883 static int ub_bd_ioctl(struct inode *inode, struct file *filp,
1884 unsigned int cmd, unsigned long arg)
1885 {
1886 struct gendisk *disk = inode->i_bdev->bd_disk;
1887 void __user *usermem = (void __user *) arg;
1888
1889 return scsi_cmd_ioctl(filp, disk, cmd, usermem);
1890 }
1891
1892 /*
1893 * This is called once a new disk was seen by the block layer or by ub_probe().
1894 * The main onjective here is to discover the features of the media such as
1895 * the capacity, read-only status, etc. USB storage generally does not
1896 * need to be spun up, but if we needed it, this would be the place.
1897 *
1898 * This call can sleep.
1899 *
1900 * The return code is not used.
1901 */
1902 static int ub_bd_revalidate(struct gendisk *disk)
1903 {
1904 struct ub_lun *lun = disk->private_data;
1905
1906 ub_revalidate(lun->udev, lun);
1907
1908 /* XXX Support sector size switching like in sr.c */
1909 blk_queue_hardsect_size(disk->queue, lun->capacity.bsize);
1910 set_capacity(disk, lun->capacity.nsec);
1911 // set_disk_ro(sdkp->disk, lun->readonly);
1912
1913 return 0;
1914 }
1915
1916 /*
1917 * The check is called by the block layer to verify if the media
1918 * is still available. It is supposed to be harmless, lightweight and
1919 * non-intrusive in case the media was not changed.
1920 *
1921 * This call can sleep.
1922 *
1923 * The return code is bool!
1924 */
1925 static int ub_bd_media_changed(struct gendisk *disk)
1926 {
1927 struct ub_lun *lun = disk->private_data;
1928
1929 if (!lun->removable)
1930 return 0;
1931
1932 /*
1933 * We clean checks always after every command, so this is not
1934 * as dangerous as it looks. If the TEST_UNIT_READY fails here,
1935 * the device is actually not ready with operator or software
1936 * intervention required. One dangerous item might be a drive which
1937 * spins itself down, and come the time to write dirty pages, this
1938 * will fail, then block layer discards the data. Since we never
1939 * spin drives up, such devices simply cannot be used with ub anyway.
1940 */
1941 if (ub_sync_tur(lun->udev, lun) != 0) {
1942 lun->changed = 1;
1943 return 1;
1944 }
1945
1946 return lun->changed;
1947 }
1948
1949 static struct block_device_operations ub_bd_fops = {
1950 .owner = THIS_MODULE,
1951 .open = ub_bd_open,
1952 .release = ub_bd_release,
1953 .ioctl = ub_bd_ioctl,
1954 .media_changed = ub_bd_media_changed,
1955 .revalidate_disk = ub_bd_revalidate,
1956 };
1957
1958 /*
1959 * Common ->done routine for commands executed synchronously.
1960 */
1961 static void ub_probe_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1962 {
1963 struct completion *cop = cmd->back;
1964 complete(cop);
1965 }
1966
1967 /*
1968 * Test if the device has a check condition on it, synchronously.
1969 */
1970 static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun)
1971 {
1972 struct ub_scsi_cmd *cmd;
1973 enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) };
1974 unsigned long flags;
1975 struct completion compl;
1976 int rc;
1977
1978 init_completion(&compl);
1979
1980 rc = -ENOMEM;
1981 if ((cmd = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
1982 goto err_alloc;
1983 memset(cmd, 0, ALLOC_SIZE);
1984
1985 cmd->cdb[0] = TEST_UNIT_READY;
1986 cmd->cdb_len = 6;
1987 cmd->dir = UB_DIR_NONE;
1988 cmd->state = UB_CMDST_INIT;
1989 cmd->lun = lun; /* This may be NULL, but that's ok */
1990 cmd->done = ub_probe_done;
1991 cmd->back = &compl;
1992
1993 spin_lock_irqsave(&sc->lock, flags);
1994 cmd->tag = sc->tagcnt++;
1995
1996 rc = ub_submit_scsi(sc, cmd);
1997 spin_unlock_irqrestore(&sc->lock, flags);
1998
1999 if (rc != 0) {
2000 printk("ub: testing ready: submit error (%d)\n", rc); /* P3 */
2001 goto err_submit;
2002 }
2003
2004 wait_for_completion(&compl);
2005
2006 rc = cmd->error;
2007
2008 if (rc == -EIO && cmd->key != 0) /* Retries for benh's key */
2009 rc = cmd->key;
2010
2011 err_submit:
2012 kfree(cmd);
2013 err_alloc:
2014 return rc;
2015 }
2016
2017 /*
2018 * Read the SCSI capacity synchronously (for probing).
2019 */
2020 static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
2021 struct ub_capacity *ret)
2022 {
2023 struct ub_scsi_cmd *cmd;
2024 struct scatterlist *sg;
2025 char *p;
2026 enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) + 8 };
2027 unsigned long flags;
2028 unsigned int bsize, shift;
2029 unsigned long nsec;
2030 struct completion compl;
2031 int rc;
2032
2033 init_completion(&compl);
2034
2035 rc = -ENOMEM;
2036 if ((cmd = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
2037 goto err_alloc;
2038 memset(cmd, 0, ALLOC_SIZE);
2039 p = (char *)cmd + sizeof(struct ub_scsi_cmd);
2040
2041 cmd->cdb[0] = 0x25;
2042 cmd->cdb_len = 10;
2043 cmd->dir = UB_DIR_READ;
2044 cmd->state = UB_CMDST_INIT;
2045 cmd->nsg = 1;
2046 sg = &cmd->sgv[0];
2047 sg->page = virt_to_page(p);
2048 sg->offset = (unsigned long)p & (PAGE_SIZE-1);
2049 sg->length = 8;
2050 cmd->len = 8;
2051 cmd->lun = lun;
2052 cmd->done = ub_probe_done;
2053 cmd->back = &compl;
2054
2055 spin_lock_irqsave(&sc->lock, flags);
2056 cmd->tag = sc->tagcnt++;
2057
2058 rc = ub_submit_scsi(sc, cmd);
2059 spin_unlock_irqrestore(&sc->lock, flags);
2060
2061 if (rc != 0) {
2062 printk("ub: reading capacity: submit error (%d)\n", rc); /* P3 */
2063 goto err_submit;
2064 }
2065
2066 wait_for_completion(&compl);
2067
2068 if (cmd->error != 0) {
2069 printk("ub: reading capacity: error %d\n", cmd->error); /* P3 */
2070 rc = -EIO;
2071 goto err_read;
2072 }
2073 if (cmd->act_len != 8) {
2074 printk("ub: reading capacity: size %d\n", cmd->act_len); /* P3 */
2075 rc = -EIO;
2076 goto err_read;
2077 }
2078
2079 /* sd.c special-cases sector size of 0 to mean 512. Needed? Safe? */
2080 nsec = be32_to_cpu(*(__be32 *)p) + 1;
2081 bsize = be32_to_cpu(*(__be32 *)(p + 4));
2082 switch (bsize) {
2083 case 512: shift = 0; break;
2084 case 1024: shift = 1; break;
2085 case 2048: shift = 2; break;
2086 case 4096: shift = 3; break;
2087 default:
2088 printk("ub: Bad sector size %u\n", bsize); /* P3 */
2089 rc = -EDOM;
2090 goto err_inv_bsize;
2091 }
2092
2093 ret->bsize = bsize;
2094 ret->bshift = shift;
2095 ret->nsec = nsec << shift;
2096 rc = 0;
2097
2098 err_inv_bsize:
2099 err_read:
2100 err_submit:
2101 kfree(cmd);
2102 err_alloc:
2103 return rc;
2104 }
2105
2106 /*
2107 */
2108 static void ub_probe_urb_complete(struct urb *urb, struct pt_regs *pt)
2109 {
2110 struct completion *cop = urb->context;
2111 complete(cop);
2112 }
2113
2114 static void ub_probe_timeout(unsigned long arg)
2115 {
2116 struct completion *cop = (struct completion *) arg;
2117 complete(cop);
2118 }
2119
2120 /*
2121 * Get number of LUNs by the way of Bulk GetMaxLUN command.
2122 */
2123 static int ub_sync_getmaxlun(struct ub_dev *sc)
2124 {
2125 int ifnum = sc->intf->cur_altsetting->desc.bInterfaceNumber;
2126 unsigned char *p;
2127 enum { ALLOC_SIZE = 1 };
2128 struct usb_ctrlrequest *cr;
2129 struct completion compl;
2130 struct timer_list timer;
2131 int nluns;
2132 int rc;
2133
2134 init_completion(&compl);
2135
2136 rc = -ENOMEM;
2137 if ((p = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
2138 goto err_alloc;
2139 *p = 55;
2140
2141 cr = &sc->work_cr;
2142 cr->bRequestType = USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE;
2143 cr->bRequest = US_BULK_GET_MAX_LUN;
2144 cr->wValue = cpu_to_le16(0);
2145 cr->wIndex = cpu_to_le16(ifnum);
2146 cr->wLength = cpu_to_le16(1);
2147
2148 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->recv_ctrl_pipe,
2149 (unsigned char*) cr, p, 1, ub_probe_urb_complete, &compl);
2150 sc->work_urb.actual_length = 0;
2151 sc->work_urb.error_count = 0;
2152 sc->work_urb.status = 0;
2153
2154 if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
2155 if (rc == -EPIPE) {
2156 printk("%s: Stall submitting GetMaxLUN, using 1 LUN\n",
2157 sc->name); /* P3 */
2158 } else {
2159 printk(KERN_NOTICE
2160 "%s: Unable to submit GetMaxLUN (%d)\n",
2161 sc->name, rc);
2162 }
2163 goto err_submit;
2164 }
2165
2166 init_timer(&timer);
2167 timer.function = ub_probe_timeout;
2168 timer.data = (unsigned long) &compl;
2169 timer.expires = jiffies + UB_CTRL_TIMEOUT;
2170 add_timer(&timer);
2171
2172 wait_for_completion(&compl);
2173
2174 del_timer_sync(&timer);
2175 usb_kill_urb(&sc->work_urb);
2176
2177 if ((rc = sc->work_urb.status) < 0) {
2178 if (rc == -EPIPE) {
2179 printk("%s: Stall at GetMaxLUN, using 1 LUN\n",
2180 sc->name); /* P3 */
2181 } else {
2182 printk(KERN_NOTICE
2183 "%s: Error at GetMaxLUN (%d)\n",
2184 sc->name, rc);
2185 }
2186 goto err_io;
2187 }
2188
2189 if (sc->work_urb.actual_length != 1) {
2190 printk("%s: GetMaxLUN returned %d bytes\n", sc->name,
2191 sc->work_urb.actual_length); /* P3 */
2192 nluns = 0;
2193 } else {
2194 if ((nluns = *p) == 55) {
2195 nluns = 0;
2196 } else {
2197 /* GetMaxLUN returns the maximum LUN number */
2198 nluns += 1;
2199 if (nluns > UB_MAX_LUNS)
2200 nluns = UB_MAX_LUNS;
2201 }
2202 printk("%s: GetMaxLUN returned %d, using %d LUNs\n", sc->name,
2203 *p, nluns); /* P3 */
2204 }
2205
2206 kfree(p);
2207 return nluns;
2208
2209 err_io:
2210 err_submit:
2211 kfree(p);
2212 err_alloc:
2213 return rc;
2214 }
2215
2216 /*
2217 * Clear initial stalls.
2218 */
2219 static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe)
2220 {
2221 int endp;
2222 struct usb_ctrlrequest *cr;
2223 struct completion compl;
2224 struct timer_list timer;
2225 int rc;
2226
2227 init_completion(&compl);
2228
2229 endp = usb_pipeendpoint(stalled_pipe);
2230 if (usb_pipein (stalled_pipe))
2231 endp |= USB_DIR_IN;
2232
2233 cr = &sc->work_cr;
2234 cr->bRequestType = USB_RECIP_ENDPOINT;
2235 cr->bRequest = USB_REQ_CLEAR_FEATURE;
2236 cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
2237 cr->wIndex = cpu_to_le16(endp);
2238 cr->wLength = cpu_to_le16(0);
2239
2240 usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
2241 (unsigned char*) cr, NULL, 0, ub_probe_urb_complete, &compl);
2242 sc->work_urb.actual_length = 0;
2243 sc->work_urb.error_count = 0;
2244 sc->work_urb.status = 0;
2245
2246 if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
2247 printk(KERN_WARNING
2248 "%s: Unable to submit a probe clear (%d)\n", sc->name, rc);
2249 return rc;
2250 }
2251
2252 init_timer(&timer);
2253 timer.function = ub_probe_timeout;
2254 timer.data = (unsigned long) &compl;
2255 timer.expires = jiffies + UB_CTRL_TIMEOUT;
2256 add_timer(&timer);
2257
2258 wait_for_completion(&compl);
2259
2260 del_timer_sync(&timer);
2261 usb_kill_urb(&sc->work_urb);
2262
2263 /* reset the endpoint toggle */
2264 usb_settoggle(sc->dev, endp, usb_pipeout(sc->last_pipe), 0);
2265
2266 return 0;
2267 }
2268
2269 /*
2270 * Get the pipe settings.
2271 */
2272 static int ub_get_pipes(struct ub_dev *sc, struct usb_device *dev,
2273 struct usb_interface *intf)
2274 {
2275 struct usb_host_interface *altsetting = intf->cur_altsetting;
2276 struct usb_endpoint_descriptor *ep_in = NULL;
2277 struct usb_endpoint_descriptor *ep_out = NULL;
2278 struct usb_endpoint_descriptor *ep;
2279 int i;
2280
2281 /*
2282 * Find the endpoints we need.
2283 * We are expecting a minimum of 2 endpoints - in and out (bulk).
2284 * We will ignore any others.
2285 */
2286 for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
2287 ep = &altsetting->endpoint[i].desc;
2288
2289 /* Is it a BULK endpoint? */
2290 if ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
2291 == USB_ENDPOINT_XFER_BULK) {
2292 /* BULK in or out? */
2293 if (ep->bEndpointAddress & USB_DIR_IN)
2294 ep_in = ep;
2295 else
2296 ep_out = ep;
2297 }
2298 }
2299
2300 if (ep_in == NULL || ep_out == NULL) {
2301 printk(KERN_NOTICE "%s: failed endpoint check\n",
2302 sc->name);
2303 return -ENODEV;
2304 }
2305
2306 /* Calculate and store the pipe values */
2307 sc->send_ctrl_pipe = usb_sndctrlpipe(dev, 0);
2308 sc->recv_ctrl_pipe = usb_rcvctrlpipe(dev, 0);
2309 sc->send_bulk_pipe = usb_sndbulkpipe(dev,
2310 ep_out->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2311 sc->recv_bulk_pipe = usb_rcvbulkpipe(dev,
2312 ep_in->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2313
2314 return 0;
2315 }
2316
2317 /*
2318 * Probing is done in the process context, which allows us to cheat
2319 * and not to build a state machine for the discovery.
2320 */
2321 static int ub_probe(struct usb_interface *intf,
2322 const struct usb_device_id *dev_id)
2323 {
2324 struct ub_dev *sc;
2325 int nluns;
2326 int rc;
2327 int i;
2328
2329 if (usb_usual_check_type(dev_id, USB_US_TYPE_UB))
2330 return -ENXIO;
2331
2332 rc = -ENOMEM;
2333 if ((sc = kmalloc(sizeof(struct ub_dev), GFP_KERNEL)) == NULL)
2334 goto err_core;
2335 memset(sc, 0, sizeof(struct ub_dev));
2336 spin_lock_init(&sc->lock);
2337 INIT_LIST_HEAD(&sc->luns);
2338 usb_init_urb(&sc->work_urb);
2339 tasklet_init(&sc->tasklet, ub_scsi_action, (unsigned long)sc);
2340 atomic_set(&sc->poison, 0);
2341 INIT_WORK(&sc->reset_work, ub_reset_task, sc);
2342 init_waitqueue_head(&sc->reset_wait);
2343
2344 init_timer(&sc->work_timer);
2345 sc->work_timer.data = (unsigned long) sc;
2346 sc->work_timer.function = ub_urb_timeout;
2347
2348 ub_init_completion(&sc->work_done);
2349 sc->work_done.done = 1; /* A little yuk, but oh well... */
2350
2351 sc->dev = interface_to_usbdev(intf);
2352 sc->intf = intf;
2353 // sc->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
2354 usb_set_intfdata(intf, sc);
2355 usb_get_dev(sc->dev);
2356 // usb_get_intf(sc->intf); /* Do we need this? */
2357
2358 snprintf(sc->name, 12, DRV_NAME "(%d.%d)",
2359 sc->dev->bus->busnum, sc->dev->devnum);
2360
2361 /* XXX Verify that we can handle the device (from descriptors) */
2362
2363 if (ub_get_pipes(sc, sc->dev, intf) != 0)
2364 goto err_dev_desc;
2365
2366 if (device_create_file(&sc->intf->dev, &dev_attr_diag) != 0)
2367 goto err_diag;
2368
2369 /*
2370 * At this point, all USB initialization is done, do upper layer.
2371 * We really hate halfway initialized structures, so from the
2372 * invariants perspective, this ub_dev is fully constructed at
2373 * this point.
2374 */
2375
2376 /*
2377 * This is needed to clear toggles. It is a problem only if we do
2378 * `rmmod ub && modprobe ub` without disconnects, but we like that.
2379 */
2380 #if 0 /* iPod Mini fails if we do this (big white iPod works) */
2381 ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
2382 ub_probe_clear_stall(sc, sc->send_bulk_pipe);
2383 #endif
2384
2385 /*
2386 * The way this is used by the startup code is a little specific.
2387 * A SCSI check causes a USB stall. Our common case code sees it
2388 * and clears the check, after which the device is ready for use.
2389 * But if a check was not present, any command other than
2390 * TEST_UNIT_READY ends with a lockup (including REQUEST_SENSE).
2391 *
2392 * If we neglect to clear the SCSI check, the first real command fails
2393 * (which is the capacity readout). We clear that and retry, but why
2394 * causing spurious retries for no reason.
2395 *
2396 * Revalidation may start with its own TEST_UNIT_READY, but that one
2397 * has to succeed, so we clear checks with an additional one here.
2398 * In any case it's not our business how revaliadation is implemented.
2399 */
2400 for (i = 0; i < 3; i++) { /* Retries for benh's key */
2401 if ((rc = ub_sync_tur(sc, NULL)) <= 0) break;
2402 if (rc != 0x6) break;
2403 msleep(10);
2404 }
2405
2406 nluns = 1;
2407 for (i = 0; i < 3; i++) {
2408 if ((rc = ub_sync_getmaxlun(sc)) < 0) {
2409 /*
2410 * This segment is taken from usb-storage. They say
2411 * that ZIP-100 needs this, but my own ZIP-100 works
2412 * fine without this.
2413 * Still, it does not seem to hurt anything.
2414 */
2415 if (rc == -EPIPE) {
2416 ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
2417 ub_probe_clear_stall(sc, sc->send_bulk_pipe);
2418 }
2419 break;
2420 }
2421 if (rc != 0) {
2422 nluns = rc;
2423 break;
2424 }
2425 msleep(100);
2426 }
2427
2428 for (i = 0; i < nluns; i++) {
2429 ub_probe_lun(sc, i);
2430 }
2431 return 0;
2432
2433 /* device_remove_file(&sc->intf->dev, &dev_attr_diag); */
2434 err_diag:
2435 err_dev_desc:
2436 usb_set_intfdata(intf, NULL);
2437 // usb_put_intf(sc->intf);
2438 usb_put_dev(sc->dev);
2439 kfree(sc);
2440 err_core:
2441 return rc;
2442 }
2443
2444 static int ub_probe_lun(struct ub_dev *sc, int lnum)
2445 {
2446 struct ub_lun *lun;
2447 request_queue_t *q;
2448 struct gendisk *disk;
2449 int rc;
2450
2451 rc = -ENOMEM;
2452 if ((lun = kmalloc(sizeof(struct ub_lun), GFP_KERNEL)) == NULL)
2453 goto err_alloc;
2454 memset(lun, 0, sizeof(struct ub_lun));
2455 lun->num = lnum;
2456
2457 rc = -ENOSR;
2458 if ((lun->id = ub_id_get()) == -1)
2459 goto err_id;
2460
2461 lun->udev = sc;
2462 list_add(&lun->link, &sc->luns);
2463
2464 snprintf(lun->name, 16, DRV_NAME "%c(%d.%d.%d)",
2465 lun->id + 'a', sc->dev->bus->busnum, sc->dev->devnum, lun->num);
2466
2467 lun->removable = 1; /* XXX Query this from the device */
2468 lun->changed = 1; /* ub_revalidate clears only */
2469 lun->first_open = 1;
2470 ub_revalidate(sc, lun);
2471
2472 rc = -ENOMEM;
2473 if ((disk = alloc_disk(UB_PARTS_PER_LUN)) == NULL)
2474 goto err_diskalloc;
2475
2476 lun->disk = disk;
2477 sprintf(disk->disk_name, DRV_NAME "%c", lun->id + 'a');
2478 sprintf(disk->devfs_name, DEVFS_NAME "/%c", lun->id + 'a');
2479 disk->major = UB_MAJOR;
2480 disk->first_minor = lun->id * UB_PARTS_PER_LUN;
2481 disk->fops = &ub_bd_fops;
2482 disk->private_data = lun;
2483 disk->driverfs_dev = &sc->intf->dev;
2484
2485 rc = -ENOMEM;
2486 if ((q = blk_init_queue(ub_request_fn, &sc->lock)) == NULL)
2487 goto err_blkqinit;
2488
2489 disk->queue = q;
2490
2491 blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
2492 blk_queue_max_hw_segments(q, UB_MAX_REQ_SG);
2493 blk_queue_max_phys_segments(q, UB_MAX_REQ_SG);
2494 blk_queue_segment_boundary(q, 0xffffffff); /* Dubious. */
2495 blk_queue_max_sectors(q, UB_MAX_SECTORS);
2496 blk_queue_hardsect_size(q, lun->capacity.bsize);
2497
2498 q->queuedata = lun;
2499
2500 set_capacity(disk, lun->capacity.nsec);
2501 if (lun->removable)
2502 disk->flags |= GENHD_FL_REMOVABLE;
2503
2504 add_disk(disk);
2505
2506 return 0;
2507
2508 err_blkqinit:
2509 put_disk(disk);
2510 err_diskalloc:
2511 list_del(&lun->link);
2512 ub_id_put(lun->id);
2513 err_id:
2514 kfree(lun);
2515 err_alloc:
2516 return rc;
2517 }
2518
2519 static void ub_disconnect(struct usb_interface *intf)
2520 {
2521 struct ub_dev *sc = usb_get_intfdata(intf);
2522 struct list_head *p;
2523 struct ub_lun *lun;
2524 struct gendisk *disk;
2525 unsigned long flags;
2526
2527 /*
2528 * Prevent ub_bd_release from pulling the rug from under us.
2529 * XXX This is starting to look like a kref.
2530 * XXX Why not to take this ref at probe time?
2531 */
2532 spin_lock_irqsave(&ub_lock, flags);
2533 sc->openc++;
2534 spin_unlock_irqrestore(&ub_lock, flags);
2535
2536 /*
2537 * Fence stall clearnings, operations triggered by unlinkings and so on.
2538 * We do not attempt to unlink any URBs, because we do not trust the
2539 * unlink paths in HC drivers. Also, we get -84 upon disconnect anyway.
2540 */
2541 atomic_set(&sc->poison, 1);
2542
2543 /*
2544 * Wait for reset to end, if any.
2545 */
2546 wait_event(sc->reset_wait, !sc->reset);
2547
2548 /*
2549 * Blow away queued commands.
2550 *
2551 * Actually, this never works, because before we get here
2552 * the HCD terminates outstanding URB(s). It causes our
2553 * SCSI command queue to advance, commands fail to submit,
2554 * and the whole queue drains. So, we just use this code to
2555 * print warnings.
2556 */
2557 spin_lock_irqsave(&sc->lock, flags);
2558 {
2559 struct ub_scsi_cmd *cmd;
2560 int cnt = 0;
2561 while ((cmd = ub_cmdq_peek(sc)) != NULL) {
2562 cmd->error = -ENOTCONN;
2563 cmd->state = UB_CMDST_DONE;
2564 ub_cmdtr_state(sc, cmd);
2565 ub_cmdq_pop(sc);
2566 (*cmd->done)(sc, cmd);
2567 cnt++;
2568 }
2569 if (cnt != 0) {
2570 printk(KERN_WARNING "%s: "
2571 "%d was queued after shutdown\n", sc->name, cnt);
2572 }
2573 }
2574 spin_unlock_irqrestore(&sc->lock, flags);
2575
2576 /*
2577 * Unregister the upper layer.
2578 */
2579 list_for_each (p, &sc->luns) {
2580 lun = list_entry(p, struct ub_lun, link);
2581 disk = lun->disk;
2582 if (disk->flags & GENHD_FL_UP)
2583 del_gendisk(disk);
2584 /*
2585 * I wish I could do:
2586 * set_bit(QUEUE_FLAG_DEAD, &q->queue_flags);
2587 * As it is, we rely on our internal poisoning and let
2588 * the upper levels to spin furiously failing all the I/O.
2589 */
2590 }
2591
2592 /*
2593 * Taking a lock on a structure which is about to be freed
2594 * is very nonsensual. Here it is largely a way to do a debug freeze,
2595 * and a bracket which shows where the nonsensual code segment ends.
2596 *
2597 * Testing for -EINPROGRESS is always a bug, so we are bending
2598 * the rules a little.
2599 */
2600 spin_lock_irqsave(&sc->lock, flags);
2601 if (sc->work_urb.status == -EINPROGRESS) { /* janitors: ignore */
2602 printk(KERN_WARNING "%s: "
2603 "URB is active after disconnect\n", sc->name);
2604 }
2605 spin_unlock_irqrestore(&sc->lock, flags);
2606
2607 /*
2608 * There is virtually no chance that other CPU runs times so long
2609 * after ub_urb_complete should have called del_timer, but only if HCD
2610 * didn't forget to deliver a callback on unlink.
2611 */
2612 del_timer_sync(&sc->work_timer);
2613
2614 /*
2615 * At this point there must be no commands coming from anyone
2616 * and no URBs left in transit.
2617 */
2618
2619 device_remove_file(&sc->intf->dev, &dev_attr_diag);
2620 usb_set_intfdata(intf, NULL);
2621 // usb_put_intf(sc->intf);
2622 sc->intf = NULL;
2623 usb_put_dev(sc->dev);
2624 sc->dev = NULL;
2625
2626 ub_put(sc);
2627 }
2628
2629 static struct usb_driver ub_driver = {
2630 .name = "ub",
2631 .probe = ub_probe,
2632 .disconnect = ub_disconnect,
2633 .id_table = ub_usb_ids,
2634 };
2635
2636 static int __init ub_init(void)
2637 {
2638 int rc;
2639
2640 if ((rc = register_blkdev(UB_MAJOR, DRV_NAME)) != 0)
2641 goto err_regblkdev;
2642 devfs_mk_dir(DEVFS_NAME);
2643
2644 if ((rc = usb_register(&ub_driver)) != 0)
2645 goto err_register;
2646
2647 usb_usual_set_present(USB_US_TYPE_UB);
2648 return 0;
2649
2650 err_register:
2651 devfs_remove(DEVFS_NAME);
2652 unregister_blkdev(UB_MAJOR, DRV_NAME);
2653 err_regblkdev:
2654 return rc;
2655 }
2656
2657 static void __exit ub_exit(void)
2658 {
2659 usb_deregister(&ub_driver);
2660
2661 devfs_remove(DEVFS_NAME);
2662 unregister_blkdev(UB_MAJOR, DRV_NAME);
2663 usb_usual_clear_present(USB_US_TYPE_UB);
2664 }
2665
2666 module_init(ub_init);
2667 module_exit(ub_exit);
2668
2669 MODULE_LICENSE("GPL");
kernel-based virtual machine