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