[PATCH] devfs: Remove devfs_mk_dir() function from the kernel tree
[linux-2.6.git] / drivers / s390 / block / dasd.c
1 /*
2  * File...........: linux/drivers/s390/block/dasd.c
3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
4  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
5  *                  Carsten Otte <Cotte@de.ibm.com>
6  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
7  * Bugreports.to..: <Linux390@de.ibm.com>
8  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
9  *
10  */
11
12 #include <linux/config.h>
13 #include <linux/kmod.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/ctype.h>
17 #include <linux/major.h>
18 #include <linux/slab.h>
19 #include <linux/buffer_head.h>
20 #include <linux/hdreg.h>
21
22 #include <asm/ccwdev.h>
23 #include <asm/ebcdic.h>
24 #include <asm/idals.h>
25 #include <asm/todclk.h>
26
27 /* This is ugly... */
28 #define PRINTK_HEADER "dasd:"
29
30 #include "dasd_int.h"
31 /*
32  * SECTION: Constant definitions to be used within this file
33  */
34 #define DASD_CHANQ_MAX_SIZE 4
35
36 /*
37  * SECTION: exported variables of dasd.c
38  */
39 debug_info_t *dasd_debug_area;
40 struct dasd_discipline *dasd_diag_discipline_pointer;
41
42 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
43 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
44                    " Copyright 2000 IBM Corporation");
45 MODULE_SUPPORTED_DEVICE("dasd");
46 MODULE_LICENSE("GPL");
47
48 /*
49  * SECTION: prototypes for static functions of dasd.c
50  */
51 static int  dasd_alloc_queue(struct dasd_device * device);
52 static void dasd_setup_queue(struct dasd_device * device);
53 static void dasd_free_queue(struct dasd_device * device);
54 static void dasd_flush_request_queue(struct dasd_device *);
55 static void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
56 static void dasd_flush_ccw_queue(struct dasd_device *, int);
57 static void dasd_tasklet(struct dasd_device *);
58 static void do_kick_device(void *data);
59
60 /*
61  * SECTION: Operations on the device structure.
62  */
63 static wait_queue_head_t dasd_init_waitq;
64
65 /*
66  * Allocate memory for a new device structure.
67  */
68 struct dasd_device *
69 dasd_alloc_device(void)
70 {
71         struct dasd_device *device;
72
73         device = kzalloc(sizeof (struct dasd_device), GFP_ATOMIC);
74         if (device == NULL)
75                 return ERR_PTR(-ENOMEM);
76         /* open_count = 0 means device online but not in use */
77         atomic_set(&device->open_count, -1);
78
79         /* Get two pages for normal block device operations. */
80         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
81         if (device->ccw_mem == NULL) {
82                 kfree(device);
83                 return ERR_PTR(-ENOMEM);
84         }
85         /* Get one page for error recovery. */
86         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
87         if (device->erp_mem == NULL) {
88                 free_pages((unsigned long) device->ccw_mem, 1);
89                 kfree(device);
90                 return ERR_PTR(-ENOMEM);
91         }
92
93         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
94         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
95         spin_lock_init(&device->mem_lock);
96         spin_lock_init(&device->request_queue_lock);
97         atomic_set (&device->tasklet_scheduled, 0);
98         tasklet_init(&device->tasklet, 
99                      (void (*)(unsigned long)) dasd_tasklet,
100                      (unsigned long) device);
101         INIT_LIST_HEAD(&device->ccw_queue);
102         init_timer(&device->timer);
103         INIT_WORK(&device->kick_work, do_kick_device, device);
104         device->state = DASD_STATE_NEW;
105         device->target = DASD_STATE_NEW;
106
107         return device;
108 }
109
110 /*
111  * Free memory of a device structure.
112  */
113 void
114 dasd_free_device(struct dasd_device *device)
115 {
116         kfree(device->private);
117         free_page((unsigned long) device->erp_mem);
118         free_pages((unsigned long) device->ccw_mem, 1);
119         kfree(device);
120 }
121
122 /*
123  * Make a new device known to the system.
124  */
125 static inline int
126 dasd_state_new_to_known(struct dasd_device *device)
127 {
128         int rc;
129
130         /*
131          * As long as the device is not in state DASD_STATE_NEW we want to 
132          * keep the reference count > 0.
133          */
134         dasd_get_device(device);
135
136         rc = dasd_alloc_queue(device);
137         if (rc) {
138                 dasd_put_device(device);
139                 return rc;
140         }
141
142         device->state = DASD_STATE_KNOWN;
143         return 0;
144 }
145
146 /*
147  * Let the system forget about a device.
148  */
149 static inline void
150 dasd_state_known_to_new(struct dasd_device * device)
151 {
152         /* Disable extended error reporting for this device. */
153         dasd_eer_disable(device);
154         /* Forget the discipline information. */
155         if (device->discipline)
156                 module_put(device->discipline->owner);
157         device->discipline = NULL;
158         if (device->base_discipline)
159                 module_put(device->base_discipline->owner);
160         device->base_discipline = NULL;
161         device->state = DASD_STATE_NEW;
162
163         dasd_free_queue(device);
164
165         /* Give up reference we took in dasd_state_new_to_known. */
166         dasd_put_device(device);
167 }
168
169 /*
170  * Request the irq line for the device.
171  */
172 static inline int
173 dasd_state_known_to_basic(struct dasd_device * device)
174 {
175         int rc;
176
177         /* Allocate and register gendisk structure. */
178         rc = dasd_gendisk_alloc(device);
179         if (rc)
180                 return rc;
181
182         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
183         device->debug_area = debug_register(device->cdev->dev.bus_id, 1, 2,
184                                             8 * sizeof (long));
185         debug_register_view(device->debug_area, &debug_sprintf_view);
186         debug_set_level(device->debug_area, DBF_EMERG);
187         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
188
189         device->state = DASD_STATE_BASIC;
190         return 0;
191 }
192
193 /*
194  * Release the irq line for the device. Terminate any running i/o.
195  */
196 static inline void
197 dasd_state_basic_to_known(struct dasd_device * device)
198 {
199         dasd_gendisk_free(device);
200         dasd_flush_ccw_queue(device, 1);
201         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
202         if (device->debug_area != NULL) {
203                 debug_unregister(device->debug_area);
204                 device->debug_area = NULL;
205         }
206         device->state = DASD_STATE_KNOWN;
207 }
208
209 /*
210  * Do the initial analysis. The do_analysis function may return
211  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
212  * until the discipline decides to continue the startup sequence
213  * by calling the function dasd_change_state. The eckd disciplines
214  * uses this to start a ccw that detects the format. The completion
215  * interrupt for this detection ccw uses the kernel event daemon to
216  * trigger the call to dasd_change_state. All this is done in the
217  * discipline code, see dasd_eckd.c.
218  * After the analysis ccw is done (do_analysis returned 0) the block
219  * device is setup.
220  * In case the analysis returns an error, the device setup is stopped
221  * (a fake disk was already added to allow formatting).
222  */
223 static inline int
224 dasd_state_basic_to_ready(struct dasd_device * device)
225 {
226         int rc;
227
228         rc = 0;
229         if (device->discipline->do_analysis != NULL)
230                 rc = device->discipline->do_analysis(device);
231         if (rc) {
232                 if (rc != -EAGAIN)
233                         device->state = DASD_STATE_UNFMT;
234                 return rc;
235         }
236         /* make disk known with correct capacity */
237         dasd_setup_queue(device);
238         set_capacity(device->gdp, device->blocks << device->s2b_shift);
239         device->state = DASD_STATE_READY;
240         rc = dasd_scan_partitions(device);
241         if (rc)
242                 device->state = DASD_STATE_BASIC;
243         return rc;
244 }
245
246 /*
247  * Remove device from block device layer. Destroy dirty buffers.
248  * Forget format information. Check if the target level is basic
249  * and if it is create fake disk for formatting.
250  */
251 static inline void
252 dasd_state_ready_to_basic(struct dasd_device * device)
253 {
254         dasd_flush_ccw_queue(device, 0);
255         dasd_destroy_partitions(device);
256         dasd_flush_request_queue(device);
257         device->blocks = 0;
258         device->bp_block = 0;
259         device->s2b_shift = 0;
260         device->state = DASD_STATE_BASIC;
261 }
262
263 /*
264  * Back to basic.
265  */
266 static inline void
267 dasd_state_unfmt_to_basic(struct dasd_device * device)
268 {
269         device->state = DASD_STATE_BASIC;
270 }
271
272 /*
273  * Make the device online and schedule the bottom half to start
274  * the requeueing of requests from the linux request queue to the
275  * ccw queue.
276  */
277 static inline int
278 dasd_state_ready_to_online(struct dasd_device * device)
279 {
280         device->state = DASD_STATE_ONLINE;
281         dasd_schedule_bh(device);
282         return 0;
283 }
284
285 /*
286  * Stop the requeueing of requests again.
287  */
288 static inline void
289 dasd_state_online_to_ready(struct dasd_device * device)
290 {
291         device->state = DASD_STATE_READY;
292 }
293
294 /*
295  * Device startup state changes.
296  */
297 static inline int
298 dasd_increase_state(struct dasd_device *device)
299 {
300         int rc;
301
302         rc = 0;
303         if (device->state == DASD_STATE_NEW &&
304             device->target >= DASD_STATE_KNOWN)
305                 rc = dasd_state_new_to_known(device);
306
307         if (!rc &&
308             device->state == DASD_STATE_KNOWN &&
309             device->target >= DASD_STATE_BASIC)
310                 rc = dasd_state_known_to_basic(device);
311
312         if (!rc &&
313             device->state == DASD_STATE_BASIC &&
314             device->target >= DASD_STATE_READY)
315                 rc = dasd_state_basic_to_ready(device);
316
317         if (!rc &&
318             device->state == DASD_STATE_UNFMT &&
319             device->target > DASD_STATE_UNFMT)
320                 rc = -EPERM;
321
322         if (!rc &&
323             device->state == DASD_STATE_READY &&
324             device->target >= DASD_STATE_ONLINE)
325                 rc = dasd_state_ready_to_online(device);
326
327         return rc;
328 }
329
330 /*
331  * Device shutdown state changes.
332  */
333 static inline int
334 dasd_decrease_state(struct dasd_device *device)
335 {
336         if (device->state == DASD_STATE_ONLINE &&
337             device->target <= DASD_STATE_READY)
338                 dasd_state_online_to_ready(device);
339         
340         if (device->state == DASD_STATE_READY &&
341             device->target <= DASD_STATE_BASIC)
342                 dasd_state_ready_to_basic(device);
343
344         if (device->state == DASD_STATE_UNFMT &&
345             device->target <= DASD_STATE_BASIC)
346                 dasd_state_unfmt_to_basic(device);
347
348         if (device->state == DASD_STATE_BASIC &&
349             device->target <= DASD_STATE_KNOWN)
350                 dasd_state_basic_to_known(device);
351         
352         if (device->state == DASD_STATE_KNOWN &&
353             device->target <= DASD_STATE_NEW)
354                 dasd_state_known_to_new(device);
355
356         return 0;
357 }
358
359 /*
360  * This is the main startup/shutdown routine.
361  */
362 static void
363 dasd_change_state(struct dasd_device *device)
364 {
365         int rc;
366
367         if (device->state == device->target)
368                 /* Already where we want to go today... */
369                 return;
370         if (device->state < device->target)
371                 rc = dasd_increase_state(device);
372         else
373                 rc = dasd_decrease_state(device);
374         if (rc && rc != -EAGAIN)
375                 device->target = device->state;
376
377         if (device->state == device->target)
378                 wake_up(&dasd_init_waitq);
379 }
380
381 /*
382  * Kick starter for devices that did not complete the startup/shutdown
383  * procedure or were sleeping because of a pending state.
384  * dasd_kick_device will schedule a call do do_kick_device to the kernel
385  * event daemon.
386  */
387 static void
388 do_kick_device(void *data)
389 {
390         struct dasd_device *device;
391
392         device = (struct dasd_device *) data;
393         dasd_change_state(device);
394         dasd_schedule_bh(device);
395         dasd_put_device(device);
396 }
397
398 void
399 dasd_kick_device(struct dasd_device *device)
400 {
401         dasd_get_device(device);
402         /* queue call to dasd_kick_device to the kernel event daemon. */
403         schedule_work(&device->kick_work);
404 }
405
406 /*
407  * Set the target state for a device and starts the state change.
408  */
409 void
410 dasd_set_target_state(struct dasd_device *device, int target)
411 {
412         /* If we are in probeonly mode stop at DASD_STATE_READY. */
413         if (dasd_probeonly && target > DASD_STATE_READY)
414                 target = DASD_STATE_READY;
415         if (device->target != target) {
416                 if (device->state == target)
417                         wake_up(&dasd_init_waitq);
418                 device->target = target;
419         }
420         if (device->state != device->target)
421                 dasd_change_state(device);
422 }
423
424 /*
425  * Enable devices with device numbers in [from..to].
426  */
427 static inline int
428 _wait_for_device(struct dasd_device *device)
429 {
430         return (device->state == device->target);
431 }
432
433 void
434 dasd_enable_device(struct dasd_device *device)
435 {
436         dasd_set_target_state(device, DASD_STATE_ONLINE);
437         if (device->state <= DASD_STATE_KNOWN)
438                 /* No discipline for device found. */
439                 dasd_set_target_state(device, DASD_STATE_NEW);
440         /* Now wait for the devices to come up. */
441         wait_event(dasd_init_waitq, _wait_for_device(device));
442 }
443
444 /*
445  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
446  */
447 #ifdef CONFIG_DASD_PROFILE
448
449 struct dasd_profile_info_t dasd_global_profile;
450 unsigned int dasd_profile_level = DASD_PROFILE_OFF;
451
452 /*
453  * Increments counter in global and local profiling structures.
454  */
455 #define dasd_profile_counter(value, counter, device) \
456 { \
457         int index; \
458         for (index = 0; index < 31 && value >> (2+index); index++); \
459         dasd_global_profile.counter[index]++; \
460         device->profile.counter[index]++; \
461 }
462
463 /*
464  * Add profiling information for cqr before execution.
465  */
466 static inline void
467 dasd_profile_start(struct dasd_device *device, struct dasd_ccw_req * cqr,
468                    struct request *req)
469 {
470         struct list_head *l;
471         unsigned int counter;
472
473         if (dasd_profile_level != DASD_PROFILE_ON)
474                 return;
475
476         /* count the length of the chanq for statistics */
477         counter = 0;
478         list_for_each(l, &device->ccw_queue)
479                 if (++counter >= 31)
480                         break;
481         dasd_global_profile.dasd_io_nr_req[counter]++;
482         device->profile.dasd_io_nr_req[counter]++;
483 }
484
485 /*
486  * Add profiling information for cqr after execution.
487  */
488 static inline void
489 dasd_profile_end(struct dasd_device *device, struct dasd_ccw_req * cqr,
490                  struct request *req)
491 {
492         long strtime, irqtime, endtime, tottime;        /* in microseconds */
493         long tottimeps, sectors;
494
495         if (dasd_profile_level != DASD_PROFILE_ON)
496                 return;
497
498         sectors = req->nr_sectors;
499         if (!cqr->buildclk || !cqr->startclk ||
500             !cqr->stopclk || !cqr->endclk ||
501             !sectors)
502                 return;
503
504         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
505         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
506         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
507         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
508         tottimeps = tottime / sectors;
509
510         if (!dasd_global_profile.dasd_io_reqs)
511                 memset(&dasd_global_profile, 0,
512                        sizeof (struct dasd_profile_info_t));
513         dasd_global_profile.dasd_io_reqs++;
514         dasd_global_profile.dasd_io_sects += sectors;
515
516         if (!device->profile.dasd_io_reqs)
517                 memset(&device->profile, 0,
518                        sizeof (struct dasd_profile_info_t));
519         device->profile.dasd_io_reqs++;
520         device->profile.dasd_io_sects += sectors;
521
522         dasd_profile_counter(sectors, dasd_io_secs, device);
523         dasd_profile_counter(tottime, dasd_io_times, device);
524         dasd_profile_counter(tottimeps, dasd_io_timps, device);
525         dasd_profile_counter(strtime, dasd_io_time1, device);
526         dasd_profile_counter(irqtime, dasd_io_time2, device);
527         dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, device);
528         dasd_profile_counter(endtime, dasd_io_time3, device);
529 }
530 #else
531 #define dasd_profile_start(device, cqr, req) do {} while (0)
532 #define dasd_profile_end(device, cqr, req) do {} while (0)
533 #endif                          /* CONFIG_DASD_PROFILE */
534
535 /*
536  * Allocate memory for a channel program with 'cplength' channel
537  * command words and 'datasize' additional space. There are two
538  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
539  * memory and 2) dasd_smalloc_request uses the static ccw memory
540  * that gets allocated for each device.
541  */
542 struct dasd_ccw_req *
543 dasd_kmalloc_request(char *magic, int cplength, int datasize,
544                    struct dasd_device * device)
545 {
546         struct dasd_ccw_req *cqr;
547
548         /* Sanity checks */
549         BUG_ON( magic == NULL || datasize > PAGE_SIZE ||
550              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
551
552         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
553         if (cqr == NULL)
554                 return ERR_PTR(-ENOMEM);
555         cqr->cpaddr = NULL;
556         if (cplength > 0) {
557                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
558                                       GFP_ATOMIC | GFP_DMA);
559                 if (cqr->cpaddr == NULL) {
560                         kfree(cqr);
561                         return ERR_PTR(-ENOMEM);
562                 }
563         }
564         cqr->data = NULL;
565         if (datasize > 0) {
566                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
567                 if (cqr->data == NULL) {
568                         kfree(cqr->cpaddr);
569                         kfree(cqr);
570                         return ERR_PTR(-ENOMEM);
571                 }
572         }
573         strncpy((char *) &cqr->magic, magic, 4);
574         ASCEBC((char *) &cqr->magic, 4);
575         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
576         dasd_get_device(device);
577         return cqr;
578 }
579
580 struct dasd_ccw_req *
581 dasd_smalloc_request(char *magic, int cplength, int datasize,
582                    struct dasd_device * device)
583 {
584         unsigned long flags;
585         struct dasd_ccw_req *cqr;
586         char *data;
587         int size;
588
589         /* Sanity checks */
590         BUG_ON( magic == NULL || datasize > PAGE_SIZE ||
591              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
592
593         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
594         if (cplength > 0)
595                 size += cplength * sizeof(struct ccw1);
596         if (datasize > 0)
597                 size += datasize;
598         spin_lock_irqsave(&device->mem_lock, flags);
599         cqr = (struct dasd_ccw_req *)
600                 dasd_alloc_chunk(&device->ccw_chunks, size);
601         spin_unlock_irqrestore(&device->mem_lock, flags);
602         if (cqr == NULL)
603                 return ERR_PTR(-ENOMEM);
604         memset(cqr, 0, sizeof(struct dasd_ccw_req));
605         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
606         cqr->cpaddr = NULL;
607         if (cplength > 0) {
608                 cqr->cpaddr = (struct ccw1 *) data;
609                 data += cplength*sizeof(struct ccw1);
610                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
611         }
612         cqr->data = NULL;
613         if (datasize > 0) {
614                 cqr->data = data;
615                 memset(cqr->data, 0, datasize);
616         }
617         strncpy((char *) &cqr->magic, magic, 4);
618         ASCEBC((char *) &cqr->magic, 4);
619         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
620         dasd_get_device(device);
621         return cqr;
622 }
623
624 /*
625  * Free memory of a channel program. This function needs to free all the
626  * idal lists that might have been created by dasd_set_cda and the
627  * struct dasd_ccw_req itself.
628  */
629 void
630 dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
631 {
632 #ifdef CONFIG_64BIT
633         struct ccw1 *ccw;
634
635         /* Clear any idals used for the request. */
636         ccw = cqr->cpaddr;
637         do {
638                 clear_normalized_cda(ccw);
639         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
640 #endif
641         kfree(cqr->cpaddr);
642         kfree(cqr->data);
643         kfree(cqr);
644         dasd_put_device(device);
645 }
646
647 void
648 dasd_sfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
649 {
650         unsigned long flags;
651
652         spin_lock_irqsave(&device->mem_lock, flags);
653         dasd_free_chunk(&device->ccw_chunks, cqr);
654         spin_unlock_irqrestore(&device->mem_lock, flags);
655         dasd_put_device(device);
656 }
657
658 /*
659  * Check discipline magic in cqr.
660  */
661 static inline int
662 dasd_check_cqr(struct dasd_ccw_req *cqr)
663 {
664         struct dasd_device *device;
665
666         if (cqr == NULL)
667                 return -EINVAL;
668         device = cqr->device;
669         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
670                 DEV_MESSAGE(KERN_WARNING, device,
671                             " dasd_ccw_req 0x%08x magic doesn't match"
672                             " discipline 0x%08x",
673                             cqr->magic,
674                             *(unsigned int *) device->discipline->name);
675                 return -EINVAL;
676         }
677         return 0;
678 }
679
680 /*
681  * Terminate the current i/o and set the request to clear_pending.
682  * Timer keeps device runnig.
683  * ccw_device_clear can fail if the i/o subsystem
684  * is in a bad mood.
685  */
686 int
687 dasd_term_IO(struct dasd_ccw_req * cqr)
688 {
689         struct dasd_device *device;
690         int retries, rc;
691
692         /* Check the cqr */
693         rc = dasd_check_cqr(cqr);
694         if (rc)
695                 return rc;
696         retries = 0;
697         device = (struct dasd_device *) cqr->device;
698         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
699                 rc = ccw_device_clear(device->cdev, (long) cqr);
700                 switch (rc) {
701                 case 0: /* termination successful */
702                         cqr->retries--;
703                         cqr->status = DASD_CQR_CLEAR;
704                         cqr->stopclk = get_clock();
705                         DBF_DEV_EVENT(DBF_DEBUG, device,
706                                       "terminate cqr %p successful",
707                                       cqr);
708                         break;
709                 case -ENODEV:
710                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
711                                       "device gone, retry");
712                         break;
713                 case -EIO:
714                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
715                                       "I/O error, retry");
716                         break;
717                 case -EINVAL:
718                 case -EBUSY:
719                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
720                                       "device busy, retry later");
721                         break;
722                 default:
723                         DEV_MESSAGE(KERN_ERR, device,
724                                     "line %d unknown RC=%d, please "
725                                     "report to linux390@de.ibm.com",
726                                     __LINE__, rc);
727                         BUG();
728                         break;
729                 }
730                 retries++;
731         }
732         dasd_schedule_bh(device);
733         return rc;
734 }
735
736 /*
737  * Start the i/o. This start_IO can fail if the channel is really busy.
738  * In that case set up a timer to start the request later.
739  */
740 int
741 dasd_start_IO(struct dasd_ccw_req * cqr)
742 {
743         struct dasd_device *device;
744         int rc;
745
746         /* Check the cqr */
747         rc = dasd_check_cqr(cqr);
748         if (rc)
749                 return rc;
750         device = (struct dasd_device *) cqr->device;
751         if (cqr->retries < 0) {
752                 DEV_MESSAGE(KERN_DEBUG, device,
753                             "start_IO: request %p (%02x/%i) - no retry left.",
754                             cqr, cqr->status, cqr->retries);
755                 cqr->status = DASD_CQR_FAILED;
756                 return -EIO;
757         }
758         cqr->startclk = get_clock();
759         cqr->starttime = jiffies;
760         cqr->retries--;
761         rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr,
762                               cqr->lpm, 0);
763         switch (rc) {
764         case 0:
765                 cqr->status = DASD_CQR_IN_IO;
766                 DBF_DEV_EVENT(DBF_DEBUG, device,
767                               "start_IO: request %p started successful",
768                               cqr);
769                 break;
770         case -EBUSY:
771                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
772                               "start_IO: device busy, retry later");
773                 break;
774         case -ETIMEDOUT:
775                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
776                               "start_IO: request timeout, retry later");
777                 break;
778         case -EACCES:
779                 /* -EACCES indicates that the request used only a
780                  * subset of the available pathes and all these
781                  * pathes are gone.
782                  * Do a retry with all available pathes.
783                  */
784                 cqr->lpm = LPM_ANYPATH;
785                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
786                               "start_IO: selected pathes gone,"
787                               " retry on all pathes");
788                 break;
789         case -ENODEV:
790         case -EIO:
791                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
792                               "start_IO: device gone, retry");
793                 break;
794         default:
795                 DEV_MESSAGE(KERN_ERR, device,
796                             "line %d unknown RC=%d, please report"
797                             " to linux390@de.ibm.com", __LINE__, rc);
798                 BUG();
799                 break;
800         }
801         return rc;
802 }
803
804 /*
805  * Timeout function for dasd devices. This is used for different purposes
806  *  1) missing interrupt handler for normal operation
807  *  2) delayed start of request where start_IO failed with -EBUSY
808  *  3) timeout for missing state change interrupts
809  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
810  * DASD_CQR_QUEUED for 2) and 3).
811  */
812 static void
813 dasd_timeout_device(unsigned long ptr)
814 {
815         unsigned long flags;
816         struct dasd_device *device;
817
818         device = (struct dasd_device *) ptr;
819         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
820         /* re-activate request queue */
821         device->stopped &= ~DASD_STOPPED_PENDING;
822         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
823         dasd_schedule_bh(device);
824 }
825
826 /*
827  * Setup timeout for a device in jiffies.
828  */
829 void
830 dasd_set_timer(struct dasd_device *device, int expires)
831 {
832         if (expires == 0) {
833                 if (timer_pending(&device->timer))
834                         del_timer(&device->timer);
835                 return;
836         }
837         if (timer_pending(&device->timer)) {
838                 if (mod_timer(&device->timer, jiffies + expires))
839                         return;
840         }
841         device->timer.function = dasd_timeout_device;
842         device->timer.data = (unsigned long) device;
843         device->timer.expires = jiffies + expires;
844         add_timer(&device->timer);
845 }
846
847 /*
848  * Clear timeout for a device.
849  */
850 void
851 dasd_clear_timer(struct dasd_device *device)
852 {
853         if (timer_pending(&device->timer))
854                 del_timer(&device->timer);
855 }
856
857 static void
858 dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm)
859 {
860         struct dasd_ccw_req *cqr;
861         struct dasd_device *device;
862
863         cqr = (struct dasd_ccw_req *) intparm;
864         if (cqr->status != DASD_CQR_IN_IO) {
865                 MESSAGE(KERN_DEBUG,
866                         "invalid status in handle_killed_request: "
867                         "bus_id %s, status %02x",
868                         cdev->dev.bus_id, cqr->status);
869                 return;
870         }
871
872         device = (struct dasd_device *) cqr->device;
873         if (device == NULL ||
874             device != dasd_device_from_cdev(cdev) ||
875             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
876                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
877                         cdev->dev.bus_id);
878                 return;
879         }
880
881         /* Schedule request to be retried. */
882         cqr->status = DASD_CQR_QUEUED;
883
884         dasd_clear_timer(device);
885         dasd_schedule_bh(device);
886         dasd_put_device(device);
887 }
888
889 static void
890 dasd_handle_state_change_pending(struct dasd_device *device)
891 {
892         struct dasd_ccw_req *cqr;
893         struct list_head *l, *n;
894
895         /* First of all start sense subsystem status request. */
896         dasd_eer_snss(device);
897
898         device->stopped &= ~DASD_STOPPED_PENDING;
899
900         /* restart all 'running' IO on queue */
901         list_for_each_safe(l, n, &device->ccw_queue) {
902                 cqr = list_entry(l, struct dasd_ccw_req, list);
903                 if (cqr->status == DASD_CQR_IN_IO) {
904                         cqr->status = DASD_CQR_QUEUED;
905                 }
906         }
907         dasd_clear_timer(device);
908         dasd_schedule_bh(device);
909 }
910
911 /*
912  * Interrupt handler for "normal" ssch-io based dasd devices.
913  */
914 void
915 dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
916                  struct irb *irb)
917 {
918         struct dasd_ccw_req *cqr, *next;
919         struct dasd_device *device;
920         unsigned long long now;
921         int expires;
922         dasd_era_t era;
923         char mask;
924
925         if (IS_ERR(irb)) {
926                 switch (PTR_ERR(irb)) {
927                 case -EIO:
928                         dasd_handle_killed_request(cdev, intparm);
929                         break;
930                 case -ETIMEDOUT:
931                         printk(KERN_WARNING"%s(%s): request timed out\n",
932                                __FUNCTION__, cdev->dev.bus_id);
933                         //FIXME - dasd uses own timeout interface...
934                         break;
935                 default:
936                         printk(KERN_WARNING"%s(%s): unknown error %ld\n",
937                                __FUNCTION__, cdev->dev.bus_id, PTR_ERR(irb));
938                 }
939                 return;
940         }
941
942         now = get_clock();
943
944         DBF_EVENT(DBF_ERR, "Interrupt: bus_id %s CS/DS %04x ip %08x",
945                   cdev->dev.bus_id, ((irb->scsw.cstat<<8)|irb->scsw.dstat),
946                   (unsigned int) intparm);
947
948         /* first of all check for state change pending interrupt */
949         mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
950         if ((irb->scsw.dstat & mask) == mask) {
951                 device = dasd_device_from_cdev(cdev);
952                 if (!IS_ERR(device)) {
953                         dasd_handle_state_change_pending(device);
954                         dasd_put_device(device);
955                 }
956                 return;
957         }
958
959         cqr = (struct dasd_ccw_req *) intparm;
960
961         /* check for unsolicited interrupts */
962         if (cqr == NULL) {
963                 MESSAGE(KERN_DEBUG,
964                         "unsolicited interrupt received: bus_id %s",
965                         cdev->dev.bus_id);
966                 return;
967         }
968
969         device = (struct dasd_device *) cqr->device;
970         if (device == NULL ||
971             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
972                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
973                         cdev->dev.bus_id);
974                 return;
975         }
976
977         /* Check for clear pending */
978         if (cqr->status == DASD_CQR_CLEAR &&
979             irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
980                 cqr->status = DASD_CQR_QUEUED;
981                 dasd_clear_timer(device);
982                 dasd_schedule_bh(device);
983                 return;
984         }
985
986         /* check status - the request might have been killed by dyn detach */
987         if (cqr->status != DASD_CQR_IN_IO) {
988                 MESSAGE(KERN_DEBUG,
989                         "invalid status: bus_id %s, status %02x",
990                         cdev->dev.bus_id, cqr->status);
991                 return;
992         }
993         DBF_DEV_EVENT(DBF_DEBUG, device, "Int: CS/DS 0x%04x for cqr %p",
994                       ((irb->scsw.cstat << 8) | irb->scsw.dstat), cqr);
995
996         /* Find out the appropriate era_action. */
997         if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC) 
998                 era = dasd_era_fatal;
999         else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1000                  irb->scsw.cstat == 0 &&
1001                  !irb->esw.esw0.erw.cons)
1002                 era = dasd_era_none;
1003         else if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags))
1004                 era = dasd_era_fatal; /* don't recover this request */
1005         else if (irb->esw.esw0.erw.cons)
1006                 era = device->discipline->examine_error(cqr, irb);
1007         else 
1008                 era = dasd_era_recover;
1009
1010         DBF_DEV_EVENT(DBF_DEBUG, device, "era_code %d", era);
1011         expires = 0;
1012         if (era == dasd_era_none) {
1013                 cqr->status = DASD_CQR_DONE;
1014                 cqr->stopclk = now;
1015                 /* Start first request on queue if possible -> fast_io. */
1016                 if (cqr->list.next != &device->ccw_queue) {
1017                         next = list_entry(cqr->list.next,
1018                                           struct dasd_ccw_req, list);
1019                         if ((next->status == DASD_CQR_QUEUED) &&
1020                             (!device->stopped)) {
1021                                 if (device->discipline->start_IO(next) == 0)
1022                                         expires = next->expires;
1023                                 else
1024                                         DEV_MESSAGE(KERN_DEBUG, device, "%s",
1025                                                     "Interrupt fastpath "
1026                                                     "failed!");
1027                         }
1028                 }
1029         } else {                /* error */
1030                 memcpy(&cqr->irb, irb, sizeof (struct irb));
1031 #ifdef ERP_DEBUG
1032                 /* dump sense data */
1033                 dasd_log_sense(cqr, irb);
1034 #endif
1035                 switch (era) {
1036                 case dasd_era_fatal:
1037                         cqr->status = DASD_CQR_FAILED;
1038                         cqr->stopclk = now;
1039                         break;
1040                 case dasd_era_recover:
1041                         cqr->status = DASD_CQR_ERROR;
1042                         break;
1043                 default:
1044                         BUG();
1045                 }
1046         }
1047         if (expires != 0)
1048                 dasd_set_timer(device, expires);
1049         else
1050                 dasd_clear_timer(device);
1051         dasd_schedule_bh(device);
1052 }
1053
1054 /*
1055  * posts the buffer_cache about a finalized request
1056  */
1057 static inline void
1058 dasd_end_request(struct request *req, int uptodate)
1059 {
1060         if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
1061                 BUG();
1062         add_disk_randomness(req->rq_disk);
1063         end_that_request_last(req, uptodate);
1064 }
1065
1066 /*
1067  * Process finished error recovery ccw.
1068  */
1069 static inline void
1070 __dasd_process_erp(struct dasd_device *device, struct dasd_ccw_req *cqr)
1071 {
1072         dasd_erp_fn_t erp_fn;
1073
1074         if (cqr->status == DASD_CQR_DONE)
1075                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
1076         else
1077                 DEV_MESSAGE(KERN_ERR, device, "%s", "ERP unsuccessful");
1078         erp_fn = device->discipline->erp_postaction(cqr);
1079         erp_fn(cqr);
1080 }
1081
1082 /*
1083  * Process ccw request queue.
1084  */
1085 static inline void
1086 __dasd_process_ccw_queue(struct dasd_device * device,
1087                          struct list_head *final_queue)
1088 {
1089         struct list_head *l, *n;
1090         struct dasd_ccw_req *cqr;
1091         dasd_erp_fn_t erp_fn;
1092
1093 restart:
1094         /* Process request with final status. */
1095         list_for_each_safe(l, n, &device->ccw_queue) {
1096                 cqr = list_entry(l, struct dasd_ccw_req, list);
1097                 /* Stop list processing at the first non-final request. */
1098                 if (cqr->status != DASD_CQR_DONE &&
1099                     cqr->status != DASD_CQR_FAILED &&
1100                     cqr->status != DASD_CQR_ERROR)
1101                         break;
1102                 /*  Process requests with DASD_CQR_ERROR */
1103                 if (cqr->status == DASD_CQR_ERROR) {
1104                         if (cqr->irb.scsw.fctl & SCSW_FCTL_HALT_FUNC) {
1105                                 cqr->status = DASD_CQR_FAILED;
1106                                 cqr->stopclk = get_clock();
1107                         } else {
1108                                 if (cqr->irb.esw.esw0.erw.cons) {
1109                                         erp_fn = device->discipline->
1110                                                 erp_action(cqr);
1111                                         erp_fn(cqr);
1112                                 } else
1113                                         dasd_default_erp_action(cqr);
1114                         }
1115                         goto restart;
1116                 }
1117
1118                 /* First of all call extended error reporting. */
1119                 if (dasd_eer_enabled(device) &&
1120                     cqr->status == DASD_CQR_FAILED) {
1121                         dasd_eer_write(device, cqr, DASD_EER_FATALERROR);
1122
1123                         /* restart request  */
1124                         cqr->status = DASD_CQR_QUEUED;
1125                         cqr->retries = 255;
1126                         device->stopped |= DASD_STOPPED_QUIESCE;
1127                         goto restart;
1128                 }
1129
1130                 /* Process finished ERP request. */
1131                 if (cqr->refers) {
1132                         __dasd_process_erp(device, cqr);
1133                         goto restart;
1134                 }
1135
1136                 /* Rechain finished requests to final queue */
1137                 cqr->endclk = get_clock();
1138                 list_move_tail(&cqr->list, final_queue);
1139         }
1140 }
1141
1142 static void
1143 dasd_end_request_cb(struct dasd_ccw_req * cqr, void *data)
1144 {
1145         struct request *req;
1146         struct dasd_device *device;
1147         int status;
1148
1149         req = (struct request *) data;
1150         device = cqr->device;
1151         dasd_profile_end(device, cqr, req);
1152         status = cqr->device->discipline->free_cp(cqr,req);
1153         spin_lock_irq(&device->request_queue_lock);
1154         dasd_end_request(req, status);
1155         spin_unlock_irq(&device->request_queue_lock);
1156 }
1157
1158
1159 /*
1160  * Fetch requests from the block device queue.
1161  */
1162 static inline void
1163 __dasd_process_blk_queue(struct dasd_device * device)
1164 {
1165         request_queue_t *queue;
1166         struct request *req;
1167         struct dasd_ccw_req *cqr;
1168         int nr_queued;
1169
1170         queue = device->request_queue;
1171         /* No queue ? Then there is nothing to do. */
1172         if (queue == NULL)
1173                 return;
1174
1175         /*
1176          * We requeue request from the block device queue to the ccw
1177          * queue only in two states. In state DASD_STATE_READY the
1178          * partition detection is done and we need to requeue requests
1179          * for that. State DASD_STATE_ONLINE is normal block device
1180          * operation.
1181          */
1182         if (device->state != DASD_STATE_READY &&
1183             device->state != DASD_STATE_ONLINE)
1184                 return;
1185         nr_queued = 0;
1186         /* Now we try to fetch requests from the request queue */
1187         list_for_each_entry(cqr, &device->ccw_queue, list)
1188                 if (cqr->status == DASD_CQR_QUEUED)
1189                         nr_queued++;
1190         while (!blk_queue_plugged(queue) &&
1191                elv_next_request(queue) &&
1192                 nr_queued < DASD_CHANQ_MAX_SIZE) {
1193                 req = elv_next_request(queue);
1194
1195                 if (device->features & DASD_FEATURE_READONLY &&
1196                     rq_data_dir(req) == WRITE) {
1197                         DBF_DEV_EVENT(DBF_ERR, device,
1198                                       "Rejecting write request %p",
1199                                       req);
1200                         blkdev_dequeue_request(req);
1201                         dasd_end_request(req, 0);
1202                         continue;
1203                 }
1204                 if (device->stopped & DASD_STOPPED_DC_EIO) {
1205                         blkdev_dequeue_request(req);
1206                         dasd_end_request(req, 0);
1207                         continue;
1208                 }
1209                 cqr = device->discipline->build_cp(device, req);
1210                 if (IS_ERR(cqr)) {
1211                         if (PTR_ERR(cqr) == -ENOMEM)
1212                                 break;  /* terminate request queue loop */
1213                         DBF_DEV_EVENT(DBF_ERR, device,
1214                                       "CCW creation failed (rc=%ld) "
1215                                       "on request %p",
1216                                       PTR_ERR(cqr), req);
1217                         blkdev_dequeue_request(req);
1218                         dasd_end_request(req, 0);
1219                         continue;
1220                 }
1221                 cqr->callback = dasd_end_request_cb;
1222                 cqr->callback_data = (void *) req;
1223                 cqr->status = DASD_CQR_QUEUED;
1224                 blkdev_dequeue_request(req);
1225                 list_add_tail(&cqr->list, &device->ccw_queue);
1226                 dasd_profile_start(device, cqr, req);
1227                 nr_queued++;
1228         }
1229 }
1230
1231 /*
1232  * Take a look at the first request on the ccw queue and check
1233  * if it reached its expire time. If so, terminate the IO.
1234  */
1235 static inline void
1236 __dasd_check_expire(struct dasd_device * device)
1237 {
1238         struct dasd_ccw_req *cqr;
1239
1240         if (list_empty(&device->ccw_queue))
1241                 return;
1242         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1243         if (cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) {
1244                 if (time_after_eq(jiffies, cqr->expires + cqr->starttime)) {
1245                         if (device->discipline->term_IO(cqr) != 0)
1246                                 /* Hmpf, try again in 1/10 sec */
1247                                 dasd_set_timer(device, 10);
1248                 }
1249         }
1250 }
1251
1252 /*
1253  * Take a look at the first request on the ccw queue and check
1254  * if it needs to be started.
1255  */
1256 static inline void
1257 __dasd_start_head(struct dasd_device * device)
1258 {
1259         struct dasd_ccw_req *cqr;
1260         int rc;
1261
1262         if (list_empty(&device->ccw_queue))
1263                 return;
1264         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1265         if (cqr->status != DASD_CQR_QUEUED)
1266                 return;
1267         /* Non-temporary stop condition will trigger fail fast */
1268         if (device->stopped & ~DASD_STOPPED_PENDING &&
1269             test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
1270             (!dasd_eer_enabled(device))) {
1271                 cqr->status = DASD_CQR_FAILED;
1272                 dasd_schedule_bh(device);
1273                 return;
1274         }
1275         /* Don't try to start requests if device is stopped */
1276         if (device->stopped)
1277                 return;
1278
1279         rc = device->discipline->start_IO(cqr);
1280         if (rc == 0)
1281                 dasd_set_timer(device, cqr->expires);
1282         else if (rc == -EACCES) {
1283                 dasd_schedule_bh(device);
1284         } else
1285                 /* Hmpf, try again in 1/2 sec */
1286                 dasd_set_timer(device, 50);
1287 }
1288
1289 /*
1290  * Remove requests from the ccw queue. 
1291  */
1292 static void
1293 dasd_flush_ccw_queue(struct dasd_device * device, int all)
1294 {
1295         struct list_head flush_queue;
1296         struct list_head *l, *n;
1297         struct dasd_ccw_req *cqr;
1298
1299         INIT_LIST_HEAD(&flush_queue);
1300         spin_lock_irq(get_ccwdev_lock(device->cdev));
1301         list_for_each_safe(l, n, &device->ccw_queue) {
1302                 cqr = list_entry(l, struct dasd_ccw_req, list);
1303                 /* Flush all request or only block device requests? */
1304                 if (all == 0 && cqr->callback == dasd_end_request_cb)
1305                         continue;
1306                 if (cqr->status == DASD_CQR_IN_IO)
1307                         device->discipline->term_IO(cqr);
1308                 if (cqr->status != DASD_CQR_DONE ||
1309                     cqr->status != DASD_CQR_FAILED) {
1310                         cqr->status = DASD_CQR_FAILED;
1311                         cqr->stopclk = get_clock();
1312                 }
1313                 /* Process finished ERP request. */
1314                 if (cqr->refers) {
1315                         __dasd_process_erp(device, cqr);
1316                         continue;
1317                 }
1318                 /* Rechain request on device request queue */
1319                 cqr->endclk = get_clock();
1320                 list_move_tail(&cqr->list, &flush_queue);
1321         }
1322         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1323         /* Now call the callback function of flushed requests */
1324         list_for_each_safe(l, n, &flush_queue) {
1325                 cqr = list_entry(l, struct dasd_ccw_req, list);
1326                 if (cqr->callback != NULL)
1327                         (cqr->callback)(cqr, cqr->callback_data);
1328         }
1329 }
1330
1331 /*
1332  * Acquire the device lock and process queues for the device.
1333  */
1334 static void
1335 dasd_tasklet(struct dasd_device * device)
1336 {
1337         struct list_head final_queue;
1338         struct list_head *l, *n;
1339         struct dasd_ccw_req *cqr;
1340
1341         atomic_set (&device->tasklet_scheduled, 0);
1342         INIT_LIST_HEAD(&final_queue);
1343         spin_lock_irq(get_ccwdev_lock(device->cdev));
1344         /* Check expire time of first request on the ccw queue. */
1345         __dasd_check_expire(device);
1346         /* Finish off requests on ccw queue */
1347         __dasd_process_ccw_queue(device, &final_queue);
1348         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1349         /* Now call the callback function of requests with final status */
1350         list_for_each_safe(l, n, &final_queue) {
1351                 cqr = list_entry(l, struct dasd_ccw_req, list);
1352                 list_del_init(&cqr->list);
1353                 if (cqr->callback != NULL)
1354                         (cqr->callback)(cqr, cqr->callback_data);
1355         }
1356         spin_lock_irq(&device->request_queue_lock);
1357         spin_lock(get_ccwdev_lock(device->cdev));
1358         /* Get new request from the block device request queue */
1359         __dasd_process_blk_queue(device);
1360         /* Now check if the head of the ccw queue needs to be started. */
1361         __dasd_start_head(device);
1362         spin_unlock(get_ccwdev_lock(device->cdev));
1363         spin_unlock_irq(&device->request_queue_lock);
1364         dasd_put_device(device);
1365 }
1366
1367 /*
1368  * Schedules a call to dasd_tasklet over the device tasklet.
1369  */
1370 void
1371 dasd_schedule_bh(struct dasd_device * device)
1372 {
1373         /* Protect against rescheduling. */
1374         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
1375                 return;
1376         dasd_get_device(device);
1377         tasklet_hi_schedule(&device->tasklet);
1378 }
1379
1380 /*
1381  * Queue a request to the head of the ccw_queue. Start the I/O if
1382  * possible.
1383  */
1384 void
1385 dasd_add_request_head(struct dasd_ccw_req *req)
1386 {
1387         struct dasd_device *device;
1388         unsigned long flags;
1389
1390         device = req->device;
1391         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1392         req->status = DASD_CQR_QUEUED;
1393         req->device = device;
1394         list_add(&req->list, &device->ccw_queue);
1395         /* let the bh start the request to keep them in order */
1396         dasd_schedule_bh(device);
1397         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1398 }
1399
1400 /*
1401  * Queue a request to the tail of the ccw_queue. Start the I/O if
1402  * possible.
1403  */
1404 void
1405 dasd_add_request_tail(struct dasd_ccw_req *req)
1406 {
1407         struct dasd_device *device;
1408         unsigned long flags;
1409
1410         device = req->device;
1411         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1412         req->status = DASD_CQR_QUEUED;
1413         req->device = device;
1414         list_add_tail(&req->list, &device->ccw_queue);
1415         /* let the bh start the request to keep them in order */
1416         dasd_schedule_bh(device);
1417         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1418 }
1419
1420 /*
1421  * Wakeup callback.
1422  */
1423 static void
1424 dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
1425 {
1426         wake_up((wait_queue_head_t *) data);
1427 }
1428
1429 static inline int
1430 _wait_for_wakeup(struct dasd_ccw_req *cqr)
1431 {
1432         struct dasd_device *device;
1433         int rc;
1434
1435         device = cqr->device;
1436         spin_lock_irq(get_ccwdev_lock(device->cdev));
1437         rc = ((cqr->status == DASD_CQR_DONE ||
1438                cqr->status == DASD_CQR_FAILED) &&
1439               list_empty(&cqr->list));
1440         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1441         return rc;
1442 }
1443
1444 /*
1445  * Attempts to start a special ccw queue and waits for its completion.
1446  */
1447 int
1448 dasd_sleep_on(struct dasd_ccw_req * cqr)
1449 {
1450         wait_queue_head_t wait_q;
1451         struct dasd_device *device;
1452         int rc;
1453         
1454         device = cqr->device;
1455         spin_lock_irq(get_ccwdev_lock(device->cdev));
1456         
1457         init_waitqueue_head (&wait_q);
1458         cqr->callback = dasd_wakeup_cb;
1459         cqr->callback_data = (void *) &wait_q;
1460         cqr->status = DASD_CQR_QUEUED;
1461         list_add_tail(&cqr->list, &device->ccw_queue);
1462         
1463         /* let the bh start the request to keep them in order */
1464         dasd_schedule_bh(device);
1465         
1466         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1467
1468         wait_event(wait_q, _wait_for_wakeup(cqr));
1469         
1470         /* Request status is either done or failed. */
1471         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1472         return rc;
1473 }
1474
1475 /*
1476  * Attempts to start a special ccw queue and wait interruptible
1477  * for its completion.
1478  */
1479 int
1480 dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
1481 {
1482         wait_queue_head_t wait_q;
1483         struct dasd_device *device;
1484         int rc, finished;
1485
1486         device = cqr->device;
1487         spin_lock_irq(get_ccwdev_lock(device->cdev));
1488
1489         init_waitqueue_head (&wait_q);
1490         cqr->callback = dasd_wakeup_cb;
1491         cqr->callback_data = (void *) &wait_q;
1492         cqr->status = DASD_CQR_QUEUED;
1493         list_add_tail(&cqr->list, &device->ccw_queue);
1494
1495         /* let the bh start the request to keep them in order */
1496         dasd_schedule_bh(device);
1497         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1498
1499         finished = 0;
1500         while (!finished) {
1501                 rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
1502                 if (rc != -ERESTARTSYS) {
1503                         /* Request is final (done or failed) */
1504                         rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1505                         break;
1506                 }
1507                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1508                 switch (cqr->status) {
1509                 case DASD_CQR_IN_IO:
1510                         /* terminate runnig cqr */
1511                         if (device->discipline->term_IO) {
1512                                 cqr->retries = -1;
1513                                 device->discipline->term_IO(cqr);
1514                                 /*nished =
1515                                  * wait (non-interruptible) for final status
1516                                  * because signal ist still pending
1517                                  */
1518                                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1519                                 wait_event(wait_q, _wait_for_wakeup(cqr));
1520                                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1521                                 rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
1522                                 finished = 1;
1523                         }
1524                         break;
1525                 case DASD_CQR_QUEUED:
1526                         /* request  */
1527                         list_del_init(&cqr->list);
1528                         rc = -EIO;
1529                         finished = 1;
1530                         break;
1531                 default:
1532                         /* cqr with 'non-interruptable' status - just wait */
1533                         break;
1534                 }
1535                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1536         }
1537         return rc;
1538 }
1539
1540 /*
1541  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
1542  * for eckd devices) the currently running request has to be terminated
1543  * and be put back to status queued, before the special request is added
1544  * to the head of the queue. Then the special request is waited on normally.
1545  */
1546 static inline int
1547 _dasd_term_running_cqr(struct dasd_device *device)
1548 {
1549         struct dasd_ccw_req *cqr;
1550         int rc;
1551
1552         if (list_empty(&device->ccw_queue))
1553                 return 0;
1554         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1555         rc = device->discipline->term_IO(cqr);
1556         if (rc == 0) {
1557                 /* termination successful */
1558                 cqr->status = DASD_CQR_QUEUED;
1559                 cqr->startclk = cqr->stopclk = 0;
1560                 cqr->starttime = 0;
1561         }
1562         return rc;
1563 }
1564
1565 int
1566 dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
1567 {
1568         wait_queue_head_t wait_q;
1569         struct dasd_device *device;
1570         int rc;
1571         
1572         device = cqr->device;
1573         spin_lock_irq(get_ccwdev_lock(device->cdev));
1574         rc = _dasd_term_running_cqr(device);
1575         if (rc) {
1576                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1577                 return rc;
1578         }
1579         
1580         init_waitqueue_head (&wait_q);
1581         cqr->callback = dasd_wakeup_cb;
1582         cqr->callback_data = (void *) &wait_q;
1583         cqr->status = DASD_CQR_QUEUED;
1584         list_add(&cqr->list, &device->ccw_queue);
1585         
1586         /* let the bh start the request to keep them in order */
1587         dasd_schedule_bh(device);
1588         
1589         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1590
1591         wait_event(wait_q, _wait_for_wakeup(cqr));
1592         
1593         /* Request status is either done or failed. */
1594         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1595         return rc;
1596 }
1597
1598 /*
1599  * Cancels a request that was started with dasd_sleep_on_req.
1600  * This is useful to timeout requests. The request will be
1601  * terminated if it is currently in i/o.
1602  * Returns 1 if the request has been terminated.
1603  */
1604 int
1605 dasd_cancel_req(struct dasd_ccw_req *cqr)
1606 {
1607         struct dasd_device *device = cqr->device;
1608         unsigned long flags;
1609         int rc;
1610
1611         rc = 0;
1612         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1613         switch (cqr->status) {
1614         case DASD_CQR_QUEUED:
1615                 /* request was not started - just set to failed */
1616                 cqr->status = DASD_CQR_FAILED;
1617                 break;
1618         case DASD_CQR_IN_IO:
1619                 /* request in IO - terminate IO and release again */
1620                 if (device->discipline->term_IO(cqr) != 0)
1621                         /* what to do if unable to terminate ??????
1622                            e.g. not _IN_IO */
1623                         cqr->status = DASD_CQR_FAILED;
1624                 cqr->stopclk = get_clock();
1625                 rc = 1;
1626                 break;
1627         case DASD_CQR_DONE:
1628         case DASD_CQR_FAILED:
1629                 /* already finished - do nothing */
1630                 break;
1631         default:
1632                 DEV_MESSAGE(KERN_ALERT, device,
1633                             "invalid status %02x in request",
1634                             cqr->status);
1635                 BUG();
1636
1637         }
1638         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1639         dasd_schedule_bh(device);
1640         return rc;
1641 }
1642
1643 /*
1644  * SECTION: Block device operations (request queue, partitions, open, release).
1645  */
1646
1647 /*
1648  * Dasd request queue function. Called from ll_rw_blk.c
1649  */
1650 static void
1651 do_dasd_request(request_queue_t * queue)
1652 {
1653         struct dasd_device *device;
1654
1655         device = (struct dasd_device *) queue->queuedata;
1656         spin_lock(get_ccwdev_lock(device->cdev));
1657         /* Get new request from the block device request queue */
1658         __dasd_process_blk_queue(device);
1659         /* Now check if the head of the ccw queue needs to be started. */
1660         __dasd_start_head(device);
1661         spin_unlock(get_ccwdev_lock(device->cdev));
1662 }
1663
1664 /*
1665  * Allocate and initialize request queue and default I/O scheduler.
1666  */
1667 static int
1668 dasd_alloc_queue(struct dasd_device * device)
1669 {
1670         int rc;
1671
1672         device->request_queue = blk_init_queue(do_dasd_request,
1673                                                &device->request_queue_lock);
1674         if (device->request_queue == NULL)
1675                 return -ENOMEM;
1676
1677         device->request_queue->queuedata = device;
1678
1679         elevator_exit(device->request_queue->elevator);
1680         rc = elevator_init(device->request_queue, "deadline");
1681         if (rc) {
1682                 blk_cleanup_queue(device->request_queue);
1683                 return rc;
1684         }
1685         return 0;
1686 }
1687
1688 /*
1689  * Allocate and initialize request queue.
1690  */
1691 static void
1692 dasd_setup_queue(struct dasd_device * device)
1693 {
1694         int max;
1695
1696         blk_queue_hardsect_size(device->request_queue, device->bp_block);
1697         max = device->discipline->max_blocks << device->s2b_shift;
1698         blk_queue_max_sectors(device->request_queue, max);
1699         blk_queue_max_phys_segments(device->request_queue, -1L);
1700         blk_queue_max_hw_segments(device->request_queue, -1L);
1701         blk_queue_max_segment_size(device->request_queue, -1L);
1702         blk_queue_segment_boundary(device->request_queue, -1L);
1703         blk_queue_ordered(device->request_queue, QUEUE_ORDERED_TAG, NULL);
1704 }
1705
1706 /*
1707  * Deactivate and free request queue.
1708  */
1709 static void
1710 dasd_free_queue(struct dasd_device * device)
1711 {
1712         if (device->request_queue) {
1713                 blk_cleanup_queue(device->request_queue);
1714                 device->request_queue = NULL;
1715         }
1716 }
1717
1718 /*
1719  * Flush request on the request queue.
1720  */
1721 static void
1722 dasd_flush_request_queue(struct dasd_device * device)
1723 {
1724         struct request *req;
1725
1726         if (!device->request_queue)
1727                 return;
1728         
1729         spin_lock_irq(&device->request_queue_lock);
1730         while (!list_empty(&device->request_queue->queue_head)) {
1731                 req = elv_next_request(device->request_queue);
1732                 if (req == NULL)
1733                         break;
1734                 dasd_end_request(req, 0);
1735                 blkdev_dequeue_request(req);
1736         }
1737         spin_unlock_irq(&device->request_queue_lock);
1738 }
1739
1740 static int
1741 dasd_open(struct inode *inp, struct file *filp)
1742 {
1743         struct gendisk *disk = inp->i_bdev->bd_disk;
1744         struct dasd_device *device = disk->private_data;
1745         int rc;
1746
1747         atomic_inc(&device->open_count);
1748         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1749                 rc = -ENODEV;
1750                 goto unlock;
1751         }
1752
1753         if (!try_module_get(device->discipline->owner)) {
1754                 rc = -EINVAL;
1755                 goto unlock;
1756         }
1757
1758         if (dasd_probeonly) {
1759                 DEV_MESSAGE(KERN_INFO, device, "%s",
1760                             "No access to device due to probeonly mode");
1761                 rc = -EPERM;
1762                 goto out;
1763         }
1764
1765         if (device->state <= DASD_STATE_BASIC) {
1766                 DBF_DEV_EVENT(DBF_ERR, device, " %s",
1767                               " Cannot open unrecognized device");
1768                 rc = -ENODEV;
1769                 goto out;
1770         }
1771
1772         return 0;
1773
1774 out:
1775         module_put(device->discipline->owner);
1776 unlock:
1777         atomic_dec(&device->open_count);
1778         return rc;
1779 }
1780
1781 static int
1782 dasd_release(struct inode *inp, struct file *filp)
1783 {
1784         struct gendisk *disk = inp->i_bdev->bd_disk;
1785         struct dasd_device *device = disk->private_data;
1786
1787         atomic_dec(&device->open_count);
1788         module_put(device->discipline->owner);
1789         return 0;
1790 }
1791
1792 /*
1793  * Return disk geometry.
1794  */
1795 static int
1796 dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1797 {
1798         struct dasd_device *device;
1799
1800         device = bdev->bd_disk->private_data;
1801         if (!device)
1802                 return -ENODEV;
1803
1804         if (!device->discipline ||
1805             !device->discipline->fill_geometry)
1806                 return -EINVAL;
1807
1808         device->discipline->fill_geometry(device, geo);
1809         geo->start = get_start_sect(bdev) >> device->s2b_shift;
1810         return 0;
1811 }
1812
1813 struct block_device_operations
1814 dasd_device_operations = {
1815         .owner          = THIS_MODULE,
1816         .open           = dasd_open,
1817         .release        = dasd_release,
1818         .ioctl          = dasd_ioctl,
1819         .compat_ioctl   = dasd_compat_ioctl,
1820         .getgeo         = dasd_getgeo,
1821 };
1822
1823
1824 static void
1825 dasd_exit(void)
1826 {
1827 #ifdef CONFIG_PROC_FS
1828         dasd_proc_exit();
1829 #endif
1830         dasd_eer_exit();
1831         if (dasd_page_cache != NULL) {
1832                 kmem_cache_destroy(dasd_page_cache);
1833                 dasd_page_cache = NULL;
1834         }
1835         dasd_gendisk_exit();
1836         dasd_devmap_exit();
1837         devfs_remove("dasd");
1838         if (dasd_debug_area != NULL) {
1839                 debug_unregister(dasd_debug_area);
1840                 dasd_debug_area = NULL;
1841         }
1842 }
1843
1844 /*
1845  * SECTION: common functions for ccw_driver use
1846  */
1847
1848 /*
1849  * Initial attempt at a probe function. this can be simplified once
1850  * the other detection code is gone.
1851  */
1852 int
1853 dasd_generic_probe (struct ccw_device *cdev,
1854                     struct dasd_discipline *discipline)
1855 {
1856         int ret;
1857
1858         ret = dasd_add_sysfs_files(cdev);
1859         if (ret) {
1860                 printk(KERN_WARNING
1861                        "dasd_generic_probe: could not add sysfs entries "
1862                        "for %s\n", cdev->dev.bus_id);
1863         } else {
1864                 cdev->handler = &dasd_int_handler;
1865         }
1866
1867         return ret;
1868 }
1869
1870 /*
1871  * This will one day be called from a global not_oper handler.
1872  * It is also used by driver_unregister during module unload.
1873  */
1874 void
1875 dasd_generic_remove (struct ccw_device *cdev)
1876 {
1877         struct dasd_device *device;
1878
1879         cdev->handler = NULL;
1880
1881         dasd_remove_sysfs_files(cdev);
1882         device = dasd_device_from_cdev(cdev);
1883         if (IS_ERR(device))
1884                 return;
1885         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1886                 /* Already doing offline processing */
1887                 dasd_put_device(device);
1888                 return;
1889         }
1890         /*
1891          * This device is removed unconditionally. Set offline
1892          * flag to prevent dasd_open from opening it while it is
1893          * no quite down yet.
1894          */
1895         dasd_set_target_state(device, DASD_STATE_NEW);
1896         /* dasd_delete_device destroys the device reference. */
1897         dasd_delete_device(device);
1898 }
1899
1900 /*
1901  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
1902  * the device is detected for the first time and is supposed to be used
1903  * or the user has started activation through sysfs.
1904  */
1905 int
1906 dasd_generic_set_online (struct ccw_device *cdev,
1907                          struct dasd_discipline *base_discipline)
1908
1909 {
1910         struct dasd_discipline *discipline;
1911         struct dasd_device *device;
1912         int rc;
1913
1914         device = dasd_create_device(cdev);
1915         if (IS_ERR(device))
1916                 return PTR_ERR(device);
1917
1918         discipline = base_discipline;
1919         if (device->features & DASD_FEATURE_USEDIAG) {
1920                 if (!dasd_diag_discipline_pointer) {
1921                         printk (KERN_WARNING
1922                                 "dasd_generic couldn't online device %s "
1923                                 "- discipline DIAG not available\n",
1924                                 cdev->dev.bus_id);
1925                         dasd_delete_device(device);
1926                         return -ENODEV;
1927                 }
1928                 discipline = dasd_diag_discipline_pointer;
1929         }
1930         if (!try_module_get(base_discipline->owner)) {
1931                 dasd_delete_device(device);
1932                 return -EINVAL;
1933         }
1934         if (!try_module_get(discipline->owner)) {
1935                 module_put(base_discipline->owner);
1936                 dasd_delete_device(device);
1937                 return -EINVAL;
1938         }
1939         device->base_discipline = base_discipline;
1940         device->discipline = discipline;
1941
1942         rc = discipline->check_device(device);
1943         if (rc) {
1944                 printk (KERN_WARNING
1945                         "dasd_generic couldn't online device %s "
1946                         "with discipline %s rc=%i\n",
1947                         cdev->dev.bus_id, discipline->name, rc);
1948                 module_put(discipline->owner);
1949                 module_put(base_discipline->owner);
1950                 dasd_delete_device(device);
1951                 return rc;
1952         }
1953
1954         dasd_set_target_state(device, DASD_STATE_ONLINE);
1955         if (device->state <= DASD_STATE_KNOWN) {
1956                 printk (KERN_WARNING
1957                         "dasd_generic discipline not found for %s\n",
1958                         cdev->dev.bus_id);
1959                 rc = -ENODEV;
1960                 dasd_set_target_state(device, DASD_STATE_NEW);
1961                 dasd_delete_device(device);
1962         } else
1963                 pr_debug("dasd_generic device %s found\n",
1964                                 cdev->dev.bus_id);
1965
1966         /* FIXME: we have to wait for the root device but we don't want
1967          * to wait for each single device but for all at once. */
1968         wait_event(dasd_init_waitq, _wait_for_device(device));
1969
1970         dasd_put_device(device);
1971
1972         return rc;
1973 }
1974
1975 int
1976 dasd_generic_set_offline (struct ccw_device *cdev)
1977 {
1978         struct dasd_device *device;
1979         int max_count, open_count;
1980
1981         device = dasd_device_from_cdev(cdev);
1982         if (IS_ERR(device))
1983                 return PTR_ERR(device);
1984         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1985                 /* Already doing offline processing */
1986                 dasd_put_device(device);
1987                 return 0;
1988         }
1989         /*
1990          * We must make sure that this device is currently not in use.
1991          * The open_count is increased for every opener, that includes
1992          * the blkdev_get in dasd_scan_partitions. We are only interested
1993          * in the other openers.
1994          */
1995         max_count = device->bdev ? 0 : -1;
1996         open_count = (int) atomic_read(&device->open_count);
1997         if (open_count > max_count) {
1998                 if (open_count > 0)
1999                         printk (KERN_WARNING "Can't offline dasd device with "
2000                                 "open count = %i.\n",
2001                                 open_count);
2002                 else
2003                         printk (KERN_WARNING "%s",
2004                                 "Can't offline dasd device due to internal "
2005                                 "use\n");
2006                 clear_bit(DASD_FLAG_OFFLINE, &device->flags);
2007                 dasd_put_device(device);
2008                 return -EBUSY;
2009         }
2010         dasd_set_target_state(device, DASD_STATE_NEW);
2011         /* dasd_delete_device destroys the device reference. */
2012         dasd_delete_device(device);
2013
2014         return 0;
2015 }
2016
2017 int
2018 dasd_generic_notify(struct ccw_device *cdev, int event)
2019 {
2020         struct dasd_device *device;
2021         struct dasd_ccw_req *cqr;
2022         unsigned long flags;
2023         int ret;
2024
2025         device = dasd_device_from_cdev(cdev);
2026         if (IS_ERR(device))
2027                 return 0;
2028         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
2029         ret = 0;
2030         switch (event) {
2031         case CIO_GONE:
2032         case CIO_NO_PATH:
2033                 /* First of all call extended error reporting. */
2034                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
2035
2036                 if (device->state < DASD_STATE_BASIC)
2037                         break;
2038                 /* Device is active. We want to keep it. */
2039                 if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
2040                         list_for_each_entry(cqr, &device->ccw_queue, list)
2041                                 if (cqr->status == DASD_CQR_IN_IO)
2042                                         cqr->status = DASD_CQR_FAILED;
2043                         device->stopped |= DASD_STOPPED_DC_EIO;
2044                 } else {
2045                         list_for_each_entry(cqr, &device->ccw_queue, list)
2046                                 if (cqr->status == DASD_CQR_IN_IO) {
2047                                         cqr->status = DASD_CQR_QUEUED;
2048                                         cqr->retries++;
2049                                 }
2050                         device->stopped |= DASD_STOPPED_DC_WAIT;
2051                         dasd_set_timer(device, 0);
2052                 }
2053                 dasd_schedule_bh(device);
2054                 ret = 1;
2055                 break;
2056         case CIO_OPER:
2057                 /* FIXME: add a sanity check. */
2058                 device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
2059                 dasd_schedule_bh(device);
2060                 ret = 1;
2061                 break;
2062         }
2063         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
2064         dasd_put_device(device);
2065         return ret;
2066 }
2067
2068 /*
2069  * Automatically online either all dasd devices (dasd_autodetect) or
2070  * all devices specified with dasd= parameters.
2071  */
2072 static int
2073 __dasd_auto_online(struct device *dev, void *data)
2074 {
2075         struct ccw_device *cdev;
2076
2077         cdev = to_ccwdev(dev);
2078         if (dasd_autodetect || dasd_busid_known(cdev->dev.bus_id) == 0)
2079                 ccw_device_set_online(cdev);
2080         return 0;
2081 }
2082
2083 void
2084 dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver)
2085 {
2086         struct device_driver *drv;
2087
2088         drv = get_driver(&dasd_discipline_driver->driver);
2089         driver_for_each_device(drv, NULL, NULL, __dasd_auto_online);
2090         put_driver(drv);
2091 }
2092
2093
2094 static int __init
2095 dasd_init(void)
2096 {
2097         int rc;
2098
2099         init_waitqueue_head(&dasd_init_waitq);
2100
2101         /* register 'common' DASD debug area, used for all DBF_XXX calls */
2102         dasd_debug_area = debug_register("dasd", 1, 2, 8 * sizeof (long));
2103         if (dasd_debug_area == NULL) {
2104                 rc = -ENOMEM;
2105                 goto failed;
2106         }
2107         debug_register_view(dasd_debug_area, &debug_sprintf_view);
2108         debug_set_level(dasd_debug_area, DBF_EMERG);
2109
2110         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
2111
2112         dasd_diag_discipline_pointer = NULL;
2113
2114         rc = dasd_devmap_init();
2115         if (rc)
2116                 goto failed;
2117         rc = dasd_gendisk_init();
2118         if (rc)
2119                 goto failed;
2120         rc = dasd_parse();
2121         if (rc)
2122                 goto failed;
2123         rc = dasd_eer_init();
2124         if (rc)
2125                 goto failed;
2126 #ifdef CONFIG_PROC_FS
2127         rc = dasd_proc_init();
2128         if (rc)
2129                 goto failed;
2130 #endif
2131
2132         return 0;
2133 failed:
2134         MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
2135         dasd_exit();
2136         return rc;
2137 }
2138
2139 module_init(dasd_init);
2140 module_exit(dasd_exit);
2141
2142 EXPORT_SYMBOL(dasd_debug_area);
2143 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
2144
2145 EXPORT_SYMBOL(dasd_add_request_head);
2146 EXPORT_SYMBOL(dasd_add_request_tail);
2147 EXPORT_SYMBOL(dasd_cancel_req);
2148 EXPORT_SYMBOL(dasd_clear_timer);
2149 EXPORT_SYMBOL(dasd_enable_device);
2150 EXPORT_SYMBOL(dasd_int_handler);
2151 EXPORT_SYMBOL(dasd_kfree_request);
2152 EXPORT_SYMBOL(dasd_kick_device);
2153 EXPORT_SYMBOL(dasd_kmalloc_request);
2154 EXPORT_SYMBOL(dasd_schedule_bh);
2155 EXPORT_SYMBOL(dasd_set_target_state);
2156 EXPORT_SYMBOL(dasd_set_timer);
2157 EXPORT_SYMBOL(dasd_sfree_request);
2158 EXPORT_SYMBOL(dasd_sleep_on);
2159 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2160 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2161 EXPORT_SYMBOL(dasd_smalloc_request);
2162 EXPORT_SYMBOL(dasd_start_IO);
2163 EXPORT_SYMBOL(dasd_term_IO);
2164
2165 EXPORT_SYMBOL_GPL(dasd_generic_probe);
2166 EXPORT_SYMBOL_GPL(dasd_generic_remove);
2167 EXPORT_SYMBOL_GPL(dasd_generic_notify);
2168 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
2169 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
2170 EXPORT_SYMBOL_GPL(dasd_generic_auto_online);
2171
2172 /*
2173  * Overrides for Emacs so that we follow Linus's tabbing style.
2174  * Emacs will notice this stuff at the end of the file and automatically
2175  * adjust the settings for this buffer only.  This must remain at the end
2176  * of the file.
2177  * ---------------------------------------------------------------------------
2178  * Local variables:
2179  * c-indent-level: 4
2180  * c-brace-imaginary-offset: 0
2181  * c-brace-offset: -4
2182  * c-argdecl-indent: 4
2183  * c-label-offset: -4
2184  * c-continued-statement-offset: 4
2185  * c-continued-brace-offset: 0
2186  * indent-tabs-mode: 1
2187  * tab-width: 8
2188  * End:
2189  */