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