f779f674dfa0414b498f1cf0be497e4a87a89291
[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  * $Revision: 1.172 $
11  */
12
13 #include <linux/config.h>
14 #include <linux/kmod.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/ctype.h>
18 #include <linux/major.h>
19 #include <linux/slab.h>
20 #include <linux/buffer_head.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_PARM(dasd, "1-" __MODULE_STRING(256) "s");
47 MODULE_LICENSE("GPL");
48
49 /*
50  * SECTION: prototypes for static functions of dasd.c
51  */
52 static int  dasd_alloc_queue(struct dasd_device * device);
53 static void dasd_setup_queue(struct dasd_device * device);
54 static void dasd_free_queue(struct dasd_device * device);
55 static void dasd_flush_request_queue(struct dasd_device *);
56 static void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
57 static void dasd_flush_ccw_queue(struct dasd_device *, int);
58 static void dasd_tasklet(struct dasd_device *);
59 static void do_kick_device(void *data);
60
61 /*
62  * SECTION: Operations on the device structure.
63  */
64 static wait_queue_head_t dasd_init_waitq;
65
66 /*
67  * Allocate memory for a new device structure.
68  */
69 struct dasd_device *
70 dasd_alloc_device(void)
71 {
72         struct dasd_device *device;
73
74         device = kmalloc(sizeof (struct dasd_device), GFP_ATOMIC);
75         if (device == NULL)
76                 return ERR_PTR(-ENOMEM);
77         memset(device, 0, sizeof (struct dasd_device));
78         /* open_count = 0 means device online but not in use */
79         atomic_set(&device->open_count, -1);
80
81         /* Get two pages for normal block device operations. */
82         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
83         if (device->ccw_mem == NULL) {
84                 kfree(device);
85                 return ERR_PTR(-ENOMEM);
86         }
87         /* Get one page for error recovery. */
88         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
89         if (device->erp_mem == NULL) {
90                 free_pages((unsigned long) device->ccw_mem, 1);
91                 kfree(device);
92                 return ERR_PTR(-ENOMEM);
93         }
94
95         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
96         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
97         spin_lock_init(&device->mem_lock);
98         spin_lock_init(&device->request_queue_lock);
99         atomic_set (&device->tasklet_scheduled, 0);
100         tasklet_init(&device->tasklet, 
101                      (void (*)(unsigned long)) dasd_tasklet,
102                      (unsigned long) device);
103         INIT_LIST_HEAD(&device->ccw_queue);
104         init_timer(&device->timer);
105         INIT_WORK(&device->kick_work, do_kick_device, device);
106         device->state = DASD_STATE_NEW;
107         device->target = DASD_STATE_NEW;
108
109         return device;
110 }
111
112 /*
113  * Free memory of a device structure.
114  */
115 void
116 dasd_free_device(struct dasd_device *device)
117 {
118         kfree(device->private);
119         free_page((unsigned long) device->erp_mem);
120         free_pages((unsigned long) device->ccw_mem, 1);
121         kfree(device);
122 }
123
124 /*
125  * Make a new device known to the system.
126  */
127 static inline int
128 dasd_state_new_to_known(struct dasd_device *device)
129 {
130         int rc;
131
132         /*
133          * As long as the device is not in state DASD_STATE_NEW we want to 
134          * keep the reference count > 0.
135          */
136         dasd_get_device(device);
137
138         rc = dasd_alloc_queue(device);
139         if (rc) {
140                 dasd_put_device(device);
141                 return rc;
142         }
143
144         device->state = DASD_STATE_KNOWN;
145         return 0;
146 }
147
148 /*
149  * Let the system forget about a device.
150  */
151 static inline void
152 dasd_state_known_to_new(struct dasd_device * device)
153 {
154         /* Forget the discipline information. */
155         device->discipline = NULL;
156         device->state = DASD_STATE_NEW;
157
158         dasd_free_queue(device);
159
160         /* Give up reference we took in dasd_state_new_to_known. */
161         dasd_put_device(device);
162 }
163
164 /*
165  * Request the irq line for the device.
166  */
167 static inline int
168 dasd_state_known_to_basic(struct dasd_device * device)
169 {
170         int rc;
171
172         /* Allocate and register gendisk structure. */
173         rc = dasd_gendisk_alloc(device);
174         if (rc)
175                 return rc;
176
177         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
178         device->debug_area = debug_register(device->cdev->dev.bus_id, 1, 2,
179                                             8 * sizeof (long));
180         debug_register_view(device->debug_area, &debug_sprintf_view);
181         debug_set_level(device->debug_area, DBF_EMERG);
182         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
183
184         device->state = DASD_STATE_BASIC;
185         return 0;
186 }
187
188 /*
189  * Release the irq line for the device. Terminate any running i/o.
190  */
191 static inline void
192 dasd_state_basic_to_known(struct dasd_device * device)
193 {
194         dasd_gendisk_free(device);
195         dasd_flush_ccw_queue(device, 1);
196         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
197         if (device->debug_area != NULL) {
198                 debug_unregister(device->debug_area);
199                 device->debug_area = NULL;
200         }
201         device->state = DASD_STATE_KNOWN;
202 }
203
204 /*
205  * Do the initial analysis. The do_analysis function may return
206  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
207  * until the discipline decides to continue the startup sequence
208  * by calling the function dasd_change_state. The eckd disciplines
209  * uses this to start a ccw that detects the format. The completion
210  * interrupt for this detection ccw uses the kernel event daemon to
211  * trigger the call to dasd_change_state. All this is done in the
212  * discipline code, see dasd_eckd.c.
213  * After the analysis ccw is done (do_analysis returned 0 or error)
214  * the block device is setup. Either a fake disk is added to allow
215  * formatting or a proper device request queue is created.
216  */
217 static inline int
218 dasd_state_basic_to_ready(struct dasd_device * device)
219 {
220         int rc;
221
222         rc = 0;
223         if (device->discipline->do_analysis != NULL)
224                 rc = device->discipline->do_analysis(device);
225         if (rc)
226                 return rc;
227         dasd_setup_queue(device);
228         device->state = DASD_STATE_READY;
229         if (dasd_scan_partitions(device) != 0)
230                 device->state = DASD_STATE_BASIC;
231         return 0;
232 }
233
234 /*
235  * Remove device from block device layer. Destroy dirty buffers.
236  * Forget format information. Check if the target level is basic
237  * and if it is create fake disk for formatting.
238  */
239 static inline void
240 dasd_state_ready_to_basic(struct dasd_device * device)
241 {
242         dasd_flush_ccw_queue(device, 0);
243         dasd_destroy_partitions(device);
244         dasd_flush_request_queue(device);
245         device->blocks = 0;
246         device->bp_block = 0;
247         device->s2b_shift = 0;
248         device->state = DASD_STATE_BASIC;
249 }
250
251 /*
252  * Make the device online and schedule the bottom half to start
253  * the requeueing of requests from the linux request queue to the
254  * ccw queue.
255  */
256 static inline int
257 dasd_state_ready_to_online(struct dasd_device * device)
258 {
259         device->state = DASD_STATE_ONLINE;
260         dasd_schedule_bh(device);
261         return 0;
262 }
263
264 /*
265  * Stop the requeueing of requests again.
266  */
267 static inline void
268 dasd_state_online_to_ready(struct dasd_device * device)
269 {
270         device->state = DASD_STATE_READY;
271 }
272
273 /*
274  * Device startup state changes.
275  */
276 static inline int
277 dasd_increase_state(struct dasd_device *device)
278 {
279         int rc;
280
281         rc = 0;
282         if (device->state == DASD_STATE_NEW &&
283             device->target >= DASD_STATE_KNOWN)
284                 rc = dasd_state_new_to_known(device);
285
286         if (!rc &&
287             device->state == DASD_STATE_KNOWN &&
288             device->target >= DASD_STATE_BASIC)
289                 rc = dasd_state_known_to_basic(device);
290
291         if (!rc &&
292             device->state == DASD_STATE_BASIC &&
293             device->target >= DASD_STATE_READY)
294                 rc = dasd_state_basic_to_ready(device);
295
296         if (!rc &&
297             device->state == DASD_STATE_READY &&
298             device->target >= DASD_STATE_ONLINE)
299                 rc = dasd_state_ready_to_online(device);
300
301         return rc;
302 }
303
304 /*
305  * Device shutdown state changes.
306  */
307 static inline int
308 dasd_decrease_state(struct dasd_device *device)
309 {
310         if (device->state == DASD_STATE_ONLINE &&
311             device->target <= DASD_STATE_READY)
312                 dasd_state_online_to_ready(device);
313         
314         if (device->state == DASD_STATE_READY &&
315             device->target <= DASD_STATE_BASIC)
316                 dasd_state_ready_to_basic(device);
317         
318         if (device->state == DASD_STATE_BASIC && 
319             device->target <= DASD_STATE_KNOWN)
320                 dasd_state_basic_to_known(device);
321         
322         if (device->state == DASD_STATE_KNOWN &&
323             device->target <= DASD_STATE_NEW)
324                 dasd_state_known_to_new(device);
325
326         return 0;
327 }
328
329 /*
330  * This is the main startup/shutdown routine.
331  */
332 static void
333 dasd_change_state(struct dasd_device *device)
334 {
335         int rc;
336
337         if (device->state == device->target)
338                 /* Already where we want to go today... */
339                 return;
340         if (device->state < device->target)
341                 rc = dasd_increase_state(device);
342         else
343                 rc = dasd_decrease_state(device);
344         if (rc && rc != -EAGAIN)
345                 device->target = device->state;
346
347         if (device->state == device->target)
348                 wake_up(&dasd_init_waitq);
349 }
350
351 /*
352  * Kick starter for devices that did not complete the startup/shutdown
353  * procedure or were sleeping because of a pending state.
354  * dasd_kick_device will schedule a call do do_kick_device to the kernel
355  * event daemon.
356  */
357 static void
358 do_kick_device(void *data)
359 {
360         struct dasd_device *device;
361
362         device = (struct dasd_device *) data;
363         dasd_change_state(device);
364         dasd_schedule_bh(device);
365         dasd_put_device(device);
366 }
367
368 void
369 dasd_kick_device(struct dasd_device *device)
370 {
371         dasd_get_device(device);
372         /* queue call to dasd_kick_device to the kernel event daemon. */
373         schedule_work(&device->kick_work);
374 }
375
376 /*
377  * Set the target state for a device and starts the state change.
378  */
379 void
380 dasd_set_target_state(struct dasd_device *device, int target)
381 {
382         /* If we are in probeonly mode stop at DASD_STATE_READY. */
383         if (dasd_probeonly && target > DASD_STATE_READY)
384                 target = DASD_STATE_READY;
385         if (device->target != target) {
386                 if (device->state == target)
387                         wake_up(&dasd_init_waitq);
388                 device->target = target;
389         }
390         if (device->state != device->target)
391                 dasd_change_state(device);
392 }
393
394 /*
395  * Enable devices with device numbers in [from..to].
396  */
397 static inline int
398 _wait_for_device(struct dasd_device *device)
399 {
400         return (device->state == device->target);
401 }
402
403 void
404 dasd_enable_device(struct dasd_device *device)
405 {
406         dasd_set_target_state(device, DASD_STATE_ONLINE);
407         if (device->state <= DASD_STATE_KNOWN)
408                 /* No discipline for device found. */
409                 dasd_set_target_state(device, DASD_STATE_NEW);
410         /* Now wait for the devices to come up. */
411         wait_event(dasd_init_waitq, _wait_for_device(device));
412 }
413
414 /*
415  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
416  */
417 #ifdef CONFIG_DASD_PROFILE
418
419 struct dasd_profile_info_t dasd_global_profile;
420 unsigned int dasd_profile_level = DASD_PROFILE_OFF;
421
422 /*
423  * Increments counter in global and local profiling structures.
424  */
425 #define dasd_profile_counter(value, counter, device) \
426 { \
427         int index; \
428         for (index = 0; index < 31 && value >> (2+index); index++); \
429         dasd_global_profile.counter[index]++; \
430         device->profile.counter[index]++; \
431 }
432
433 /*
434  * Add profiling information for cqr before execution.
435  */
436 static inline void
437 dasd_profile_start(struct dasd_device *device, struct dasd_ccw_req * cqr,
438                    struct request *req)
439 {
440         struct list_head *l;
441         unsigned int counter;
442
443         if (dasd_profile_level != DASD_PROFILE_ON)
444                 return;
445
446         /* count the length of the chanq for statistics */
447         counter = 0;
448         list_for_each(l, &device->ccw_queue)
449                 if (++counter >= 31)
450                         break;
451         dasd_global_profile.dasd_io_nr_req[counter]++;
452         device->profile.dasd_io_nr_req[counter]++;
453 }
454
455 /*
456  * Add profiling information for cqr after execution.
457  */
458 static inline void
459 dasd_profile_end(struct dasd_device *device, struct dasd_ccw_req * cqr,
460                  struct request *req)
461 {
462         long strtime, irqtime, endtime, tottime;        /* in microseconds */
463         long tottimeps, sectors;
464
465         if (dasd_profile_level != DASD_PROFILE_ON)
466                 return;
467
468         sectors = req->nr_sectors;
469         if (!cqr->buildclk || !cqr->startclk ||
470             !cqr->stopclk || !cqr->endclk ||
471             !sectors)
472                 return;
473
474         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
475         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
476         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
477         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
478         tottimeps = tottime / sectors;
479
480         if (!dasd_global_profile.dasd_io_reqs)
481                 memset(&dasd_global_profile, 0,
482                        sizeof (struct dasd_profile_info_t));
483         dasd_global_profile.dasd_io_reqs++;
484         dasd_global_profile.dasd_io_sects += sectors;
485
486         if (!device->profile.dasd_io_reqs)
487                 memset(&device->profile, 0,
488                        sizeof (struct dasd_profile_info_t));
489         device->profile.dasd_io_reqs++;
490         device->profile.dasd_io_sects += sectors;
491
492         dasd_profile_counter(sectors, dasd_io_secs, device);
493         dasd_profile_counter(tottime, dasd_io_times, device);
494         dasd_profile_counter(tottimeps, dasd_io_timps, device);
495         dasd_profile_counter(strtime, dasd_io_time1, device);
496         dasd_profile_counter(irqtime, dasd_io_time2, device);
497         dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, device);
498         dasd_profile_counter(endtime, dasd_io_time3, device);
499 }
500 #else
501 #define dasd_profile_start(device, cqr, req) do {} while (0)
502 #define dasd_profile_end(device, cqr, req) do {} while (0)
503 #endif                          /* CONFIG_DASD_PROFILE */
504
505 /*
506  * Allocate memory for a channel program with 'cplength' channel
507  * command words and 'datasize' additional space. There are two
508  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
509  * memory and 2) dasd_smalloc_request uses the static ccw memory
510  * that gets allocated for each device.
511  */
512 struct dasd_ccw_req *
513 dasd_kmalloc_request(char *magic, int cplength, int datasize,
514                    struct dasd_device * device)
515 {
516         struct dasd_ccw_req *cqr;
517
518         /* Sanity checks */
519         if ( magic == NULL || datasize > PAGE_SIZE ||
520              (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
521                 BUG();
522
523         cqr = kmalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
524         if (cqr == NULL)
525                 return ERR_PTR(-ENOMEM);
526         memset(cqr, 0, sizeof(struct dasd_ccw_req));
527         cqr->cpaddr = NULL;
528         if (cplength > 0) {
529                 cqr->cpaddr = kmalloc(cplength*sizeof(struct ccw1),
530                                       GFP_ATOMIC | GFP_DMA);
531                 if (cqr->cpaddr == NULL) {
532                         kfree(cqr);
533                         return ERR_PTR(-ENOMEM);
534                 }
535                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
536         }
537         cqr->data = NULL;
538         if (datasize > 0) {
539                 cqr->data = kmalloc(datasize, GFP_ATOMIC | GFP_DMA);
540                 if (cqr->data == NULL) {
541                         kfree(cqr->cpaddr);
542                         kfree(cqr);
543                         return ERR_PTR(-ENOMEM);
544                 }
545                 memset(cqr->data, 0, datasize);
546         }
547         strncpy((char *) &cqr->magic, magic, 4);
548         ASCEBC((char *) &cqr->magic, 4);
549         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
550         dasd_get_device(device);
551         return cqr;
552 }
553
554 struct dasd_ccw_req *
555 dasd_smalloc_request(char *magic, int cplength, int datasize,
556                    struct dasd_device * device)
557 {
558         unsigned long flags;
559         struct dasd_ccw_req *cqr;
560         char *data;
561         int size;
562
563         /* Sanity checks */
564         if ( magic == NULL || datasize > PAGE_SIZE ||
565              (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
566                 BUG();
567
568         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
569         if (cplength > 0)
570                 size += cplength * sizeof(struct ccw1);
571         if (datasize > 0)
572                 size += datasize;
573         spin_lock_irqsave(&device->mem_lock, flags);
574         cqr = (struct dasd_ccw_req *)
575                 dasd_alloc_chunk(&device->ccw_chunks, size);
576         spin_unlock_irqrestore(&device->mem_lock, flags);
577         if (cqr == NULL)
578                 return ERR_PTR(-ENOMEM);
579         memset(cqr, 0, sizeof(struct dasd_ccw_req));
580         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
581         cqr->cpaddr = NULL;
582         if (cplength > 0) {
583                 cqr->cpaddr = (struct ccw1 *) data;
584                 data += cplength*sizeof(struct ccw1);
585                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
586         }
587         cqr->data = NULL;
588         if (datasize > 0) {
589                 cqr->data = data;
590                 memset(cqr->data, 0, datasize);
591         }
592         strncpy((char *) &cqr->magic, magic, 4);
593         ASCEBC((char *) &cqr->magic, 4);
594         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
595         dasd_get_device(device);
596         return cqr;
597 }
598
599 /*
600  * Free memory of a channel program. This function needs to free all the
601  * idal lists that might have been created by dasd_set_cda and the
602  * struct dasd_ccw_req itself.
603  */
604 void
605 dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
606 {
607 #ifdef CONFIG_64BIT
608         struct ccw1 *ccw;
609
610         /* Clear any idals used for the request. */
611         ccw = cqr->cpaddr;
612         do {
613                 clear_normalized_cda(ccw);
614         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
615 #endif
616         kfree(cqr->cpaddr);
617         kfree(cqr->data);
618         kfree(cqr);
619         dasd_put_device(device);
620 }
621
622 void
623 dasd_sfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
624 {
625         unsigned long flags;
626
627         spin_lock_irqsave(&device->mem_lock, flags);
628         dasd_free_chunk(&device->ccw_chunks, cqr);
629         spin_unlock_irqrestore(&device->mem_lock, flags);
630         dasd_put_device(device);
631 }
632
633 /*
634  * Check discipline magic in cqr.
635  */
636 static inline int
637 dasd_check_cqr(struct dasd_ccw_req *cqr)
638 {
639         struct dasd_device *device;
640
641         if (cqr == NULL)
642                 return -EINVAL;
643         device = cqr->device;
644         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
645                 DEV_MESSAGE(KERN_WARNING, device,
646                             " dasd_ccw_req 0x%08x magic doesn't match"
647                             " discipline 0x%08x",
648                             cqr->magic,
649                             *(unsigned int *) device->discipline->name);
650                 return -EINVAL;
651         }
652         return 0;
653 }
654
655 /*
656  * Terminate the current i/o and set the request to clear_pending.
657  * Timer keeps device runnig.
658  * ccw_device_clear can fail if the i/o subsystem
659  * is in a bad mood.
660  */
661 int
662 dasd_term_IO(struct dasd_ccw_req * cqr)
663 {
664         struct dasd_device *device;
665         int retries, rc;
666
667         /* Check the cqr */
668         rc = dasd_check_cqr(cqr);
669         if (rc)
670                 return rc;
671         retries = 0;
672         device = (struct dasd_device *) cqr->device;
673         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
674                 rc = ccw_device_clear(device->cdev, (long) cqr);
675                 switch (rc) {
676                 case 0: /* termination successful */
677                         if (cqr->retries > 0) {
678                                 cqr->retries--;
679                                 cqr->status = DASD_CQR_CLEAR;
680                         } else
681                                 cqr->status = DASD_CQR_FAILED;
682                         cqr->stopclk = get_clock();
683                         DBF_DEV_EVENT(DBF_DEBUG, device,
684                                       "terminate cqr %p successful",
685                                       cqr);
686                         break;
687                 case -ENODEV:
688                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
689                                       "device gone, retry");
690                         break;
691                 case -EIO:
692                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
693                                       "I/O error, retry");
694                         break;
695                 case -EINVAL:
696                 case -EBUSY:
697                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
698                                       "device busy, retry later");
699                         break;
700                 default:
701                         DEV_MESSAGE(KERN_ERR, device,
702                                     "line %d unknown RC=%d, please "
703                                     "report to linux390@de.ibm.com",
704                                     __LINE__, rc);
705                         BUG();
706                         break;
707                 }
708                 retries++;
709         }
710         dasd_schedule_bh(device);
711         return rc;
712 }
713
714 /*
715  * Start the i/o. This start_IO can fail if the channel is really busy.
716  * In that case set up a timer to start the request later.
717  */
718 int
719 dasd_start_IO(struct dasd_ccw_req * cqr)
720 {
721         struct dasd_device *device;
722         int rc;
723
724         /* Check the cqr */
725         rc = dasd_check_cqr(cqr);
726         if (rc)
727                 return rc;
728         device = (struct dasd_device *) cqr->device;
729         if (cqr->retries < 0) {
730                 DEV_MESSAGE(KERN_DEBUG, device,
731                             "start_IO: request %p (%02x/%i) - no retry left.",
732                             cqr, cqr->status, cqr->retries);
733                 cqr->status = DASD_CQR_FAILED;
734                 return -EIO;
735         }
736         cqr->startclk = get_clock();
737         cqr->starttime = jiffies;
738         cqr->retries--;
739         rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr,
740                               cqr->lpm, 0);
741         switch (rc) {
742         case 0:
743                 cqr->status = DASD_CQR_IN_IO;
744                 DBF_DEV_EVENT(DBF_DEBUG, device,
745                               "start_IO: request %p started successful",
746                               cqr);
747                 break;
748         case -EBUSY:
749                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
750                               "start_IO: device busy, retry later");
751                 break;
752         case -ETIMEDOUT:
753                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
754                               "start_IO: request timeout, retry later");
755                 break;
756         case -EACCES:
757                 /* -EACCES indicates that the request used only a
758                  * subset of the available pathes and all these
759                  * pathes are gone.
760                  * Do a retry with all available pathes.
761                  */
762                 cqr->lpm = LPM_ANYPATH;
763                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
764                               "start_IO: selected pathes gone,"
765                               " retry on all pathes");
766                 break;
767         case -ENODEV:
768         case -EIO:
769                 DBF_DEV_EVENT(DBF_ERR, device, "%s",
770                               "start_IO: device gone, retry");
771                 break;
772         default:
773                 DEV_MESSAGE(KERN_ERR, device,
774                             "line %d unknown RC=%d, please report"
775                             " to linux390@de.ibm.com", __LINE__, rc);
776                 BUG();
777                 break;
778         }
779         return rc;
780 }
781
782 /*
783  * Timeout function for dasd devices. This is used for different purposes
784  *  1) missing interrupt handler for normal operation
785  *  2) delayed start of request where start_IO failed with -EBUSY
786  *  3) timeout for missing state change interrupts
787  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
788  * DASD_CQR_QUEUED for 2) and 3).
789  */
790 static void
791 dasd_timeout_device(unsigned long ptr)
792 {
793         unsigned long flags;
794         struct dasd_device *device;
795
796         device = (struct dasd_device *) ptr;
797         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
798         /* re-activate request queue */
799         device->stopped &= ~DASD_STOPPED_PENDING;
800         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
801         dasd_schedule_bh(device);
802 }
803
804 /*
805  * Setup timeout for a device in jiffies.
806  */
807 void
808 dasd_set_timer(struct dasd_device *device, int expires)
809 {
810         if (expires == 0) {
811                 if (timer_pending(&device->timer))
812                         del_timer(&device->timer);
813                 return;
814         }
815         if (timer_pending(&device->timer)) {
816                 if (mod_timer(&device->timer, jiffies + expires))
817                         return;
818         }
819         device->timer.function = dasd_timeout_device;
820         device->timer.data = (unsigned long) device;
821         device->timer.expires = jiffies + expires;
822         add_timer(&device->timer);
823 }
824
825 /*
826  * Clear timeout for a device.
827  */
828 void
829 dasd_clear_timer(struct dasd_device *device)
830 {
831         if (timer_pending(&device->timer))
832                 del_timer(&device->timer);
833 }
834
835 static void
836 dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm)
837 {
838         struct dasd_ccw_req *cqr;
839         struct dasd_device *device;
840
841         cqr = (struct dasd_ccw_req *) intparm;
842         if (cqr->status != DASD_CQR_IN_IO) {
843                 MESSAGE(KERN_DEBUG,
844                         "invalid status in handle_killed_request: "
845                         "bus_id %s, status %02x",
846                         cdev->dev.bus_id, cqr->status);
847                 return;
848         }
849
850         device = (struct dasd_device *) cqr->device;
851         if (device == NULL ||
852             device != dasd_device_from_cdev(cdev) ||
853             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
854                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
855                         cdev->dev.bus_id);
856                 return;
857         }
858
859         /* Schedule request to be retried. */
860         cqr->status = DASD_CQR_QUEUED;
861
862         dasd_clear_timer(device);
863         dasd_schedule_bh(device);
864         dasd_put_device(device);
865 }
866
867 static void
868 dasd_handle_state_change_pending(struct dasd_device *device)
869 {
870         struct dasd_ccw_req *cqr;
871         struct list_head *l, *n;
872
873         device->stopped &= ~DASD_STOPPED_PENDING;
874
875         /* restart all 'running' IO on queue */
876         list_for_each_safe(l, n, &device->ccw_queue) {
877                 cqr = list_entry(l, struct dasd_ccw_req, list);
878                 if (cqr->status == DASD_CQR_IN_IO) {
879                         cqr->status = DASD_CQR_QUEUED;
880                 }
881         }
882         dasd_clear_timer(device);
883         dasd_schedule_bh(device);
884 }
885
886 /*
887  * Interrupt handler for "normal" ssch-io based dasd devices.
888  */
889 void
890 dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
891                  struct irb *irb)
892 {
893         struct dasd_ccw_req *cqr, *next;
894         struct dasd_device *device;
895         unsigned long long now;
896         int expires;
897         dasd_era_t era;
898         char mask;
899
900         if (IS_ERR(irb)) {
901                 switch (PTR_ERR(irb)) {
902                 case -EIO:
903                         dasd_handle_killed_request(cdev, intparm);
904                         break;
905                 case -ETIMEDOUT:
906                         printk(KERN_WARNING"%s(%s): request timed out\n",
907                                __FUNCTION__, cdev->dev.bus_id);
908                         //FIXME - dasd uses own timeout interface...
909                         break;
910                 default:
911                         printk(KERN_WARNING"%s(%s): unknown error %ld\n",
912                                __FUNCTION__, cdev->dev.bus_id, PTR_ERR(irb));
913                 }
914                 return;
915         }
916
917         now = get_clock();
918
919         DBF_EVENT(DBF_ERR, "Interrupt: bus_id %s CS/DS %04x ip %08x",
920                   cdev->dev.bus_id, ((irb->scsw.cstat<<8)|irb->scsw.dstat),
921                   (unsigned int) intparm);
922
923         /* first of all check for state change pending interrupt */
924         mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
925         if ((irb->scsw.dstat & mask) == mask) {
926                 device = dasd_device_from_cdev(cdev);
927                 if (!IS_ERR(device)) {
928                         dasd_handle_state_change_pending(device);
929                         dasd_put_device(device);
930                 }
931                 return;
932         }
933
934         cqr = (struct dasd_ccw_req *) intparm;
935
936         /* check for unsolicited interrupts */
937         if (cqr == NULL) {
938                 MESSAGE(KERN_DEBUG,
939                         "unsolicited interrupt received: bus_id %s",
940                         cdev->dev.bus_id);
941                 return;
942         }
943
944         device = (struct dasd_device *) cqr->device;
945         if (device == NULL ||
946             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
947                 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
948                         cdev->dev.bus_id);
949                 return;
950         }
951
952         /* Check for clear pending */
953         if (cqr->status == DASD_CQR_CLEAR &&
954             irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
955                 cqr->status = DASD_CQR_QUEUED;
956                 dasd_clear_timer(device);
957                 dasd_schedule_bh(device);
958                 return;
959         }
960
961         /* check status - the request might have been killed by dyn detach */
962         if (cqr->status != DASD_CQR_IN_IO) {
963                 MESSAGE(KERN_DEBUG,
964                         "invalid status: bus_id %s, status %02x",
965                         cdev->dev.bus_id, cqr->status);
966                 return;
967         }
968         DBF_DEV_EVENT(DBF_DEBUG, device, "Int: CS/DS 0x%04x for cqr %p",
969                       ((irb->scsw.cstat << 8) | irb->scsw.dstat), cqr);
970
971         /* Find out the appropriate era_action. */
972         if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC) 
973                 era = dasd_era_fatal;
974         else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
975                  irb->scsw.cstat == 0 &&
976                  !irb->esw.esw0.erw.cons)
977                 era = dasd_era_none;
978         else if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags))
979                 era = dasd_era_fatal; /* don't recover this request */
980         else if (irb->esw.esw0.erw.cons)
981                 era = device->discipline->examine_error(cqr, irb);
982         else 
983                 era = dasd_era_recover;
984
985         DBF_DEV_EVENT(DBF_DEBUG, device, "era_code %d", era);
986         expires = 0;
987         if (era == dasd_era_none) {
988                 cqr->status = DASD_CQR_DONE;
989                 cqr->stopclk = now;
990                 /* Start first request on queue if possible -> fast_io. */
991                 if (cqr->list.next != &device->ccw_queue) {
992                         next = list_entry(cqr->list.next,
993                                           struct dasd_ccw_req, list);
994                         if ((next->status == DASD_CQR_QUEUED) &&
995                             (!device->stopped)) {
996                                 if (device->discipline->start_IO(next) == 0)
997                                         expires = next->expires;
998                                 else
999                                         DEV_MESSAGE(KERN_DEBUG, device, "%s",
1000                                                     "Interrupt fastpath "
1001                                                     "failed!");
1002                         }
1003                 }
1004         } else {                /* error */
1005                 memcpy(&cqr->irb, irb, sizeof (struct irb));
1006 #ifdef ERP_DEBUG
1007                 /* dump sense data */
1008                 dasd_log_sense(cqr, irb);
1009 #endif
1010                 switch (era) {
1011                 case dasd_era_fatal:
1012                         cqr->status = DASD_CQR_FAILED;
1013                         cqr->stopclk = now;
1014                         break;
1015                 case dasd_era_recover:
1016                         cqr->status = DASD_CQR_ERROR;
1017                         break;
1018                 default:
1019                         BUG();
1020                 }
1021         }
1022         if (expires != 0)
1023                 dasd_set_timer(device, expires);
1024         else
1025                 dasd_clear_timer(device);
1026         dasd_schedule_bh(device);
1027 }
1028
1029 /*
1030  * posts the buffer_cache about a finalized request
1031  */
1032 static inline void
1033 dasd_end_request(struct request *req, int uptodate)
1034 {
1035         if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
1036                 BUG();
1037         add_disk_randomness(req->rq_disk);
1038         end_that_request_last(req, uptodate);
1039 }
1040
1041 /*
1042  * Process finished error recovery ccw.
1043  */
1044 static inline void
1045 __dasd_process_erp(struct dasd_device *device, struct dasd_ccw_req *cqr)
1046 {
1047         dasd_erp_fn_t erp_fn;
1048
1049         if (cqr->status == DASD_CQR_DONE)
1050                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
1051         else
1052                 DEV_MESSAGE(KERN_ERR, device, "%s", "ERP unsuccessful");
1053         erp_fn = device->discipline->erp_postaction(cqr);
1054         erp_fn(cqr);
1055 }
1056
1057 /*
1058  * Process ccw request queue.
1059  */
1060 static inline void
1061 __dasd_process_ccw_queue(struct dasd_device * device,
1062                          struct list_head *final_queue)
1063 {
1064         struct list_head *l, *n;
1065         struct dasd_ccw_req *cqr;
1066         dasd_erp_fn_t erp_fn;
1067
1068 restart:
1069         /* Process request with final status. */
1070         list_for_each_safe(l, n, &device->ccw_queue) {
1071                 cqr = list_entry(l, struct dasd_ccw_req, list);
1072                 /* Stop list processing at the first non-final request. */
1073                 if (cqr->status != DASD_CQR_DONE &&
1074                     cqr->status != DASD_CQR_FAILED &&
1075                     cqr->status != DASD_CQR_ERROR)
1076                         break;
1077                 /*  Process requests with DASD_CQR_ERROR */
1078                 if (cqr->status == DASD_CQR_ERROR) {
1079                         if (cqr->irb.scsw.fctl & SCSW_FCTL_HALT_FUNC) {
1080                                 cqr->status = DASD_CQR_FAILED;
1081                                 cqr->stopclk = get_clock();
1082                         } else {
1083                                 if (cqr->irb.esw.esw0.erw.cons) {
1084                                         erp_fn = device->discipline->
1085                                                 erp_action(cqr);
1086                                         erp_fn(cqr);
1087                                 } else
1088                                         dasd_default_erp_action(cqr);
1089                         }
1090                         goto restart;
1091                 }
1092                 /* Process finished ERP request. */
1093                 if (cqr->refers) {
1094                         __dasd_process_erp(device, cqr);
1095                         goto restart;
1096                 }
1097
1098                 /* Rechain finished requests to final queue */
1099                 cqr->endclk = get_clock();
1100                 list_move_tail(&cqr->list, final_queue);
1101         }
1102 }
1103
1104 static void
1105 dasd_end_request_cb(struct dasd_ccw_req * cqr, void *data)
1106 {
1107         struct request *req;
1108         struct dasd_device *device;
1109         int status;
1110
1111         req = (struct request *) data;
1112         device = cqr->device;
1113         dasd_profile_end(device, cqr, req);
1114         status = cqr->device->discipline->free_cp(cqr,req);
1115         spin_lock_irq(&device->request_queue_lock);
1116         dasd_end_request(req, status);
1117         spin_unlock_irq(&device->request_queue_lock);
1118 }
1119
1120
1121 /*
1122  * Fetch requests from the block device queue.
1123  */
1124 static inline void
1125 __dasd_process_blk_queue(struct dasd_device * device)
1126 {
1127         request_queue_t *queue;
1128         struct request *req;
1129         struct dasd_ccw_req *cqr;
1130         int nr_queued;
1131
1132         queue = device->request_queue;
1133         /* No queue ? Then there is nothing to do. */
1134         if (queue == NULL)
1135                 return;
1136
1137         /*
1138          * We requeue request from the block device queue to the ccw
1139          * queue only in two states. In state DASD_STATE_READY the
1140          * partition detection is done and we need to requeue requests
1141          * for that. State DASD_STATE_ONLINE is normal block device
1142          * operation.
1143          */
1144         if (device->state != DASD_STATE_READY &&
1145             device->state != DASD_STATE_ONLINE)
1146                 return;
1147         nr_queued = 0;
1148         /* Now we try to fetch requests from the request queue */
1149         list_for_each_entry(cqr, &device->ccw_queue, list)
1150                 if (cqr->status == DASD_CQR_QUEUED)
1151                         nr_queued++;
1152         while (!blk_queue_plugged(queue) &&
1153                elv_next_request(queue) &&
1154                 nr_queued < DASD_CHANQ_MAX_SIZE) {
1155                 req = elv_next_request(queue);
1156
1157                 if (device->features & DASD_FEATURE_READONLY &&
1158                     rq_data_dir(req) == WRITE) {
1159                         DBF_DEV_EVENT(DBF_ERR, device,
1160                                       "Rejecting write request %p",
1161                                       req);
1162                         blkdev_dequeue_request(req);
1163                         dasd_end_request(req, 0);
1164                         continue;
1165                 }
1166                 if (device->stopped & DASD_STOPPED_DC_EIO) {
1167                         blkdev_dequeue_request(req);
1168                         dasd_end_request(req, 0);
1169                         continue;
1170                 }
1171                 cqr = device->discipline->build_cp(device, req);
1172                 if (IS_ERR(cqr)) {
1173                         if (PTR_ERR(cqr) == -ENOMEM)
1174                                 break;  /* terminate request queue loop */
1175                         DBF_DEV_EVENT(DBF_ERR, device,
1176                                       "CCW creation failed (rc=%ld) "
1177                                       "on request %p",
1178                                       PTR_ERR(cqr), req);
1179                         blkdev_dequeue_request(req);
1180                         dasd_end_request(req, 0);
1181                         continue;
1182                 }
1183                 cqr->callback = dasd_end_request_cb;
1184                 cqr->callback_data = (void *) req;
1185                 cqr->status = DASD_CQR_QUEUED;
1186                 blkdev_dequeue_request(req);
1187                 list_add_tail(&cqr->list, &device->ccw_queue);
1188                 dasd_profile_start(device, cqr, req);
1189                 nr_queued++;
1190         }
1191 }
1192
1193 /*
1194  * Take a look at the first request on the ccw queue and check
1195  * if it reached its expire time. If so, terminate the IO.
1196  */
1197 static inline void
1198 __dasd_check_expire(struct dasd_device * device)
1199 {
1200         struct dasd_ccw_req *cqr;
1201
1202         if (list_empty(&device->ccw_queue))
1203                 return;
1204         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1205         if (cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) {
1206                 if (time_after_eq(jiffies, cqr->expires + cqr->starttime)) {
1207                         if (device->discipline->term_IO(cqr) != 0)
1208                                 /* Hmpf, try again in 1/10 sec */
1209                                 dasd_set_timer(device, 10);
1210                 }
1211         }
1212 }
1213
1214 /*
1215  * Take a look at the first request on the ccw queue and check
1216  * if it needs to be started.
1217  */
1218 static inline void
1219 __dasd_start_head(struct dasd_device * device)
1220 {
1221         struct dasd_ccw_req *cqr;
1222         int rc;
1223
1224         if (list_empty(&device->ccw_queue))
1225                 return;
1226         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1227         /* check FAILFAST */
1228         if (device->stopped & ~DASD_STOPPED_PENDING &&
1229             test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags)) {
1230                 cqr->status = DASD_CQR_FAILED;
1231                 dasd_schedule_bh(device);
1232         }
1233         if ((cqr->status == DASD_CQR_QUEUED) &&
1234             (!device->stopped)) {
1235                 /* try to start the first I/O that can be started */
1236                 rc = device->discipline->start_IO(cqr);
1237                 if (rc == 0)
1238                         dasd_set_timer(device, cqr->expires);
1239                 else if (rc == -EACCES) {
1240                         dasd_schedule_bh(device);
1241                 } else
1242                         /* Hmpf, try again in 1/2 sec */
1243                         dasd_set_timer(device, 50);
1244         }
1245 }
1246
1247 /*
1248  * Remove requests from the ccw queue. 
1249  */
1250 static void
1251 dasd_flush_ccw_queue(struct dasd_device * device, int all)
1252 {
1253         struct list_head flush_queue;
1254         struct list_head *l, *n;
1255         struct dasd_ccw_req *cqr;
1256
1257         INIT_LIST_HEAD(&flush_queue);
1258         spin_lock_irq(get_ccwdev_lock(device->cdev));
1259         list_for_each_safe(l, n, &device->ccw_queue) {
1260                 cqr = list_entry(l, struct dasd_ccw_req, list);
1261                 /* Flush all request or only block device requests? */
1262                 if (all == 0 && cqr->callback == dasd_end_request_cb)
1263                         continue;
1264                 if (cqr->status == DASD_CQR_IN_IO)
1265                         device->discipline->term_IO(cqr);
1266                 if (cqr->status != DASD_CQR_DONE ||
1267                     cqr->status != DASD_CQR_FAILED) {
1268                         cqr->status = DASD_CQR_FAILED;
1269                         cqr->stopclk = get_clock();
1270                 }
1271                 /* Process finished ERP request. */
1272                 if (cqr->refers) {
1273                         __dasd_process_erp(device, cqr);
1274                         continue;
1275                 }
1276                 /* Rechain request on device request queue */
1277                 cqr->endclk = get_clock();
1278                 list_move_tail(&cqr->list, &flush_queue);
1279         }
1280         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1281         /* Now call the callback function of flushed requests */
1282         list_for_each_safe(l, n, &flush_queue) {
1283                 cqr = list_entry(l, struct dasd_ccw_req, list);
1284                 if (cqr->callback != NULL)
1285                         (cqr->callback)(cqr, cqr->callback_data);
1286         }
1287 }
1288
1289 /*
1290  * Acquire the device lock and process queues for the device.
1291  */
1292 static void
1293 dasd_tasklet(struct dasd_device * device)
1294 {
1295         struct list_head final_queue;
1296         struct list_head *l, *n;
1297         struct dasd_ccw_req *cqr;
1298
1299         atomic_set (&device->tasklet_scheduled, 0);
1300         INIT_LIST_HEAD(&final_queue);
1301         spin_lock_irq(get_ccwdev_lock(device->cdev));
1302         /* Check expire time of first request on the ccw queue. */
1303         __dasd_check_expire(device);
1304         /* Finish off requests on ccw queue */
1305         __dasd_process_ccw_queue(device, &final_queue);
1306         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1307         /* Now call the callback function of requests with final status */
1308         list_for_each_safe(l, n, &final_queue) {
1309                 cqr = list_entry(l, struct dasd_ccw_req, list);
1310                 list_del(&cqr->list);
1311                 if (cqr->callback != NULL)
1312                         (cqr->callback)(cqr, cqr->callback_data);
1313         }
1314         spin_lock_irq(&device->request_queue_lock);
1315         spin_lock(get_ccwdev_lock(device->cdev));
1316         /* Get new request from the block device request queue */
1317         __dasd_process_blk_queue(device);
1318         /* Now check if the head of the ccw queue needs to be started. */
1319         __dasd_start_head(device);
1320         spin_unlock(get_ccwdev_lock(device->cdev));
1321         spin_unlock_irq(&device->request_queue_lock);
1322         dasd_put_device(device);
1323 }
1324
1325 /*
1326  * Schedules a call to dasd_tasklet over the device tasklet.
1327  */
1328 void
1329 dasd_schedule_bh(struct dasd_device * device)
1330 {
1331         /* Protect against rescheduling. */
1332         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
1333                 return;
1334         dasd_get_device(device);
1335         tasklet_hi_schedule(&device->tasklet);
1336 }
1337
1338 /*
1339  * Queue a request to the head of the ccw_queue. Start the I/O if
1340  * possible.
1341  */
1342 void
1343 dasd_add_request_head(struct dasd_ccw_req *req)
1344 {
1345         struct dasd_device *device;
1346         unsigned long flags;
1347
1348         device = req->device;
1349         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1350         req->status = DASD_CQR_QUEUED;
1351         req->device = device;
1352         list_add(&req->list, &device->ccw_queue);
1353         /* let the bh start the request to keep them in order */
1354         dasd_schedule_bh(device);
1355         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1356 }
1357
1358 /*
1359  * Queue a request to the tail of the ccw_queue. Start the I/O if
1360  * possible.
1361  */
1362 void
1363 dasd_add_request_tail(struct dasd_ccw_req *req)
1364 {
1365         struct dasd_device *device;
1366         unsigned long flags;
1367
1368         device = req->device;
1369         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1370         req->status = DASD_CQR_QUEUED;
1371         req->device = device;
1372         list_add_tail(&req->list, &device->ccw_queue);
1373         /* let the bh start the request to keep them in order */
1374         dasd_schedule_bh(device);
1375         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1376 }
1377
1378 /*
1379  * Wakeup callback.
1380  */
1381 static void
1382 dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
1383 {
1384         wake_up((wait_queue_head_t *) data);
1385 }
1386
1387 static inline int
1388 _wait_for_wakeup(struct dasd_ccw_req *cqr)
1389 {
1390         struct dasd_device *device;
1391         int rc;
1392
1393         device = cqr->device;
1394         spin_lock_irq(get_ccwdev_lock(device->cdev));
1395         rc = cqr->status == DASD_CQR_DONE || cqr->status == DASD_CQR_FAILED;
1396         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1397         return rc;
1398 }
1399
1400 /*
1401  * Attempts to start a special ccw queue and waits for its completion.
1402  */
1403 int
1404 dasd_sleep_on(struct dasd_ccw_req * cqr)
1405 {
1406         wait_queue_head_t wait_q;
1407         struct dasd_device *device;
1408         int rc;
1409         
1410         device = cqr->device;
1411         spin_lock_irq(get_ccwdev_lock(device->cdev));
1412         
1413         init_waitqueue_head (&wait_q);
1414         cqr->callback = dasd_wakeup_cb;
1415         cqr->callback_data = (void *) &wait_q;
1416         cqr->status = DASD_CQR_QUEUED;
1417         list_add_tail(&cqr->list, &device->ccw_queue);
1418         
1419         /* let the bh start the request to keep them in order */
1420         dasd_schedule_bh(device);
1421         
1422         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1423
1424         wait_event(wait_q, _wait_for_wakeup(cqr));
1425         
1426         /* Request status is either done or failed. */
1427         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1428         return rc;
1429 }
1430
1431 /*
1432  * Attempts to start a special ccw queue and wait interruptible
1433  * for its completion.
1434  */
1435 int
1436 dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
1437 {
1438         wait_queue_head_t wait_q;
1439         struct dasd_device *device;
1440         int rc, finished;
1441
1442         device = cqr->device;
1443         spin_lock_irq(get_ccwdev_lock(device->cdev));
1444
1445         init_waitqueue_head (&wait_q);
1446         cqr->callback = dasd_wakeup_cb;
1447         cqr->callback_data = (void *) &wait_q;
1448         cqr->status = DASD_CQR_QUEUED;
1449         list_add_tail(&cqr->list, &device->ccw_queue);
1450
1451         /* let the bh start the request to keep them in order */
1452         dasd_schedule_bh(device);
1453         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1454
1455         finished = 0;
1456         while (!finished) {
1457                 rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
1458                 if (rc != -ERESTARTSYS) {
1459                         /* Request status is either done or failed. */
1460                         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1461                         break;
1462                 }
1463                 spin_lock_irq(get_ccwdev_lock(device->cdev));
1464                 if (cqr->status == DASD_CQR_IN_IO &&
1465                     device->discipline->term_IO(cqr) == 0) {
1466                         list_del(&cqr->list);
1467                         finished = 1;
1468                 }
1469                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1470         }
1471         return rc;
1472 }
1473
1474 /*
1475  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
1476  * for eckd devices) the currently running request has to be terminated
1477  * and be put back to status queued, before the special request is added
1478  * to the head of the queue. Then the special request is waited on normally.
1479  */
1480 static inline int
1481 _dasd_term_running_cqr(struct dasd_device *device)
1482 {
1483         struct dasd_ccw_req *cqr;
1484         int rc;
1485
1486         if (list_empty(&device->ccw_queue))
1487                 return 0;
1488         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1489         rc = device->discipline->term_IO(cqr);
1490         if (rc == 0) {
1491                 /* termination successful */
1492                 cqr->status = DASD_CQR_QUEUED;
1493                 cqr->startclk = cqr->stopclk = 0;
1494                 cqr->starttime = 0;
1495         }
1496         return rc;
1497 }
1498
1499 int
1500 dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
1501 {
1502         wait_queue_head_t wait_q;
1503         struct dasd_device *device;
1504         int rc;
1505         
1506         device = cqr->device;
1507         spin_lock_irq(get_ccwdev_lock(device->cdev));
1508         rc = _dasd_term_running_cqr(device);
1509         if (rc) {
1510                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1511                 return rc;
1512         }
1513         
1514         init_waitqueue_head (&wait_q);
1515         cqr->callback = dasd_wakeup_cb;
1516         cqr->callback_data = (void *) &wait_q;
1517         cqr->status = DASD_CQR_QUEUED;
1518         list_add(&cqr->list, &device->ccw_queue);
1519         
1520         /* let the bh start the request to keep them in order */
1521         dasd_schedule_bh(device);
1522         
1523         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1524
1525         wait_event(wait_q, _wait_for_wakeup(cqr));
1526         
1527         /* Request status is either done or failed. */
1528         rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1529         return rc;
1530 }
1531
1532 /*
1533  * Cancels a request that was started with dasd_sleep_on_req.
1534  * This is useful to timeout requests. The request will be
1535  * terminated if it is currently in i/o.
1536  * Returns 1 if the request has been terminated.
1537  */
1538 int
1539 dasd_cancel_req(struct dasd_ccw_req *cqr)
1540 {
1541         struct dasd_device *device = cqr->device;
1542         unsigned long flags;
1543         int rc;
1544
1545         rc = 0;
1546         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1547         switch (cqr->status) {
1548         case DASD_CQR_QUEUED:
1549                 /* request was not started - just set to failed */
1550                 cqr->status = DASD_CQR_FAILED;
1551                 break;
1552         case DASD_CQR_IN_IO:
1553                 /* request in IO - terminate IO and release again */
1554                 if (device->discipline->term_IO(cqr) != 0)
1555                         /* what to do if unable to terminate ??????
1556                            e.g. not _IN_IO */
1557                         cqr->status = DASD_CQR_FAILED;
1558                 cqr->stopclk = get_clock();
1559                 rc = 1;
1560                 break;
1561         case DASD_CQR_DONE:
1562         case DASD_CQR_FAILED:
1563                 /* already finished - do nothing */
1564                 break;
1565         default:
1566                 DEV_MESSAGE(KERN_ALERT, device,
1567                             "invalid status %02x in request",
1568                             cqr->status);
1569                 BUG();
1570
1571         }
1572         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1573         dasd_schedule_bh(device);
1574         return rc;
1575 }
1576
1577 /*
1578  * SECTION: Block device operations (request queue, partitions, open, release).
1579  */
1580
1581 /*
1582  * Dasd request queue function. Called from ll_rw_blk.c
1583  */
1584 static void
1585 do_dasd_request(request_queue_t * queue)
1586 {
1587         struct dasd_device *device;
1588
1589         device = (struct dasd_device *) queue->queuedata;
1590         spin_lock(get_ccwdev_lock(device->cdev));
1591         /* Get new request from the block device request queue */
1592         __dasd_process_blk_queue(device);
1593         /* Now check if the head of the ccw queue needs to be started. */
1594         __dasd_start_head(device);
1595         spin_unlock(get_ccwdev_lock(device->cdev));
1596 }
1597
1598 /*
1599  * Allocate and initialize request queue and default I/O scheduler.
1600  */
1601 static int
1602 dasd_alloc_queue(struct dasd_device * device)
1603 {
1604         int rc;
1605
1606         device->request_queue = blk_init_queue(do_dasd_request,
1607                                                &device->request_queue_lock);
1608         if (device->request_queue == NULL)
1609                 return -ENOMEM;
1610
1611         device->request_queue->queuedata = device;
1612
1613         elevator_exit(device->request_queue->elevator);
1614         rc = elevator_init(device->request_queue, "deadline");
1615         if (rc) {
1616                 blk_cleanup_queue(device->request_queue);
1617                 return rc;
1618         }
1619         return 0;
1620 }
1621
1622 /*
1623  * Allocate and initialize request queue.
1624  */
1625 static void
1626 dasd_setup_queue(struct dasd_device * device)
1627 {
1628         int max;
1629
1630         blk_queue_hardsect_size(device->request_queue, device->bp_block);
1631         max = device->discipline->max_blocks << device->s2b_shift;
1632         blk_queue_max_sectors(device->request_queue, max);
1633         blk_queue_max_phys_segments(device->request_queue, -1L);
1634         blk_queue_max_hw_segments(device->request_queue, -1L);
1635         blk_queue_max_segment_size(device->request_queue, -1L);
1636         blk_queue_segment_boundary(device->request_queue, -1L);
1637         blk_queue_ordered(device->request_queue, 1);
1638 }
1639
1640 /*
1641  * Deactivate and free request queue.
1642  */
1643 static void
1644 dasd_free_queue(struct dasd_device * device)
1645 {
1646         if (device->request_queue) {
1647                 blk_cleanup_queue(device->request_queue);
1648                 device->request_queue = NULL;
1649         }
1650 }
1651
1652 /*
1653  * Flush request on the request queue.
1654  */
1655 static void
1656 dasd_flush_request_queue(struct dasd_device * device)
1657 {
1658         struct request *req;
1659
1660         if (!device->request_queue)
1661                 return;
1662         
1663         spin_lock_irq(&device->request_queue_lock);
1664         while (!list_empty(&device->request_queue->queue_head)) {
1665                 req = elv_next_request(device->request_queue);
1666                 if (req == NULL)
1667                         break;
1668                 dasd_end_request(req, 0);
1669                 blkdev_dequeue_request(req);
1670         }
1671         spin_unlock_irq(&device->request_queue_lock);
1672 }
1673
1674 static int
1675 dasd_open(struct inode *inp, struct file *filp)
1676 {
1677         struct gendisk *disk = inp->i_bdev->bd_disk;
1678         struct dasd_device *device = disk->private_data;
1679         int rc;
1680
1681         atomic_inc(&device->open_count);
1682         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1683                 rc = -ENODEV;
1684                 goto unlock;
1685         }
1686
1687         if (!try_module_get(device->discipline->owner)) {
1688                 rc = -EINVAL;
1689                 goto unlock;
1690         }
1691
1692         if (dasd_probeonly) {
1693                 DEV_MESSAGE(KERN_INFO, device, "%s",
1694                             "No access to device due to probeonly mode");
1695                 rc = -EPERM;
1696                 goto out;
1697         }
1698
1699         if (device->state < DASD_STATE_BASIC) {
1700                 DBF_DEV_EVENT(DBF_ERR, device, " %s",
1701                               " Cannot open unrecognized device");
1702                 rc = -ENODEV;
1703                 goto out;
1704         }
1705
1706         return 0;
1707
1708 out:
1709         module_put(device->discipline->owner);
1710 unlock:
1711         atomic_dec(&device->open_count);
1712         return rc;
1713 }
1714
1715 static int
1716 dasd_release(struct inode *inp, struct file *filp)
1717 {
1718         struct gendisk *disk = inp->i_bdev->bd_disk;
1719         struct dasd_device *device = disk->private_data;
1720
1721         atomic_dec(&device->open_count);
1722         module_put(device->discipline->owner);
1723         return 0;
1724 }
1725
1726 struct block_device_operations
1727 dasd_device_operations = {
1728         .owner          = THIS_MODULE,
1729         .open           = dasd_open,
1730         .release        = dasd_release,
1731         .ioctl          = dasd_ioctl,
1732 };
1733
1734
1735 static void
1736 dasd_exit(void)
1737 {
1738 #ifdef CONFIG_PROC_FS
1739         dasd_proc_exit();
1740 #endif
1741         dasd_ioctl_exit();
1742         if (dasd_page_cache != NULL) {
1743                 kmem_cache_destroy(dasd_page_cache);
1744                 dasd_page_cache = NULL;
1745         }
1746         dasd_gendisk_exit();
1747         dasd_devmap_exit();
1748         devfs_remove("dasd");
1749         if (dasd_debug_area != NULL) {
1750                 debug_unregister(dasd_debug_area);
1751                 dasd_debug_area = NULL;
1752         }
1753 }
1754
1755 /*
1756  * SECTION: common functions for ccw_driver use
1757  */
1758
1759 /*
1760  * Initial attempt at a probe function. this can be simplified once
1761  * the other detection code is gone.
1762  */
1763 int
1764 dasd_generic_probe (struct ccw_device *cdev,
1765                     struct dasd_discipline *discipline)
1766 {
1767         int ret;
1768
1769         ret = dasd_add_sysfs_files(cdev);
1770         if (ret) {
1771                 printk(KERN_WARNING
1772                        "dasd_generic_probe: could not add sysfs entries "
1773                        "for %s\n", cdev->dev.bus_id);
1774         } else {
1775                 cdev->handler = &dasd_int_handler;
1776         }
1777
1778         return ret;
1779 }
1780
1781 /*
1782  * This will one day be called from a global not_oper handler.
1783  * It is also used by driver_unregister during module unload.
1784  */
1785 void
1786 dasd_generic_remove (struct ccw_device *cdev)
1787 {
1788         struct dasd_device *device;
1789
1790         cdev->handler = NULL;
1791
1792         dasd_remove_sysfs_files(cdev);
1793         device = dasd_device_from_cdev(cdev);
1794         if (IS_ERR(device))
1795                 return;
1796         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1797                 /* Already doing offline processing */
1798                 dasd_put_device(device);
1799                 return;
1800         }
1801         /*
1802          * This device is removed unconditionally. Set offline
1803          * flag to prevent dasd_open from opening it while it is
1804          * no quite down yet.
1805          */
1806         dasd_set_target_state(device, DASD_STATE_NEW);
1807         /* dasd_delete_device destroys the device reference. */
1808         dasd_delete_device(device);
1809 }
1810
1811 /*
1812  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
1813  * the device is detected for the first time and is supposed to be used
1814  * or the user has started activation through sysfs.
1815  */
1816 int
1817 dasd_generic_set_online (struct ccw_device *cdev,
1818                          struct dasd_discipline *discipline)
1819
1820 {
1821         struct dasd_device *device;
1822         int rc;
1823
1824         device = dasd_create_device(cdev);
1825         if (IS_ERR(device))
1826                 return PTR_ERR(device);
1827
1828         if (device->features & DASD_FEATURE_USEDIAG) {
1829                 if (!dasd_diag_discipline_pointer) {
1830                         printk (KERN_WARNING
1831                                 "dasd_generic couldn't online device %s "
1832                                 "- discipline DIAG not available\n",
1833                                 cdev->dev.bus_id);
1834                         dasd_delete_device(device);
1835                         return -ENODEV;
1836                 }
1837                 discipline = dasd_diag_discipline_pointer;
1838         }
1839         device->discipline = discipline;
1840
1841         rc = discipline->check_device(device);
1842         if (rc) {
1843                 printk (KERN_WARNING
1844                         "dasd_generic couldn't online device %s "
1845                         "with discipline %s rc=%i\n",
1846                         cdev->dev.bus_id, discipline->name, rc);
1847                 dasd_delete_device(device);
1848                 return rc;
1849         }
1850
1851         dasd_set_target_state(device, DASD_STATE_ONLINE);
1852         if (device->state <= DASD_STATE_KNOWN) {
1853                 printk (KERN_WARNING
1854                         "dasd_generic discipline not found for %s\n",
1855                         cdev->dev.bus_id);
1856                 rc = -ENODEV;
1857                 dasd_set_target_state(device, DASD_STATE_NEW);
1858                 dasd_delete_device(device);
1859         } else
1860                 pr_debug("dasd_generic device %s found\n",
1861                                 cdev->dev.bus_id);
1862
1863         /* FIXME: we have to wait for the root device but we don't want
1864          * to wait for each single device but for all at once. */
1865         wait_event(dasd_init_waitq, _wait_for_device(device));
1866
1867         dasd_put_device(device);
1868
1869         return rc;
1870 }
1871
1872 int
1873 dasd_generic_set_offline (struct ccw_device *cdev)
1874 {
1875         struct dasd_device *device;
1876         int max_count;
1877
1878         device = dasd_device_from_cdev(cdev);
1879         if (IS_ERR(device))
1880                 return PTR_ERR(device);
1881         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1882                 /* Already doing offline processing */
1883                 dasd_put_device(device);
1884                 return 0;
1885         }
1886         /*
1887          * We must make sure that this device is currently not in use.
1888          * The open_count is increased for every opener, that includes
1889          * the blkdev_get in dasd_scan_partitions. We are only interested
1890          * in the other openers.
1891          */
1892         max_count = device->bdev ? 0 : -1;
1893         if (atomic_read(&device->open_count) > max_count) {
1894                 printk (KERN_WARNING "Can't offline dasd device with open"
1895                         " count = %i.\n",
1896                         atomic_read(&device->open_count));
1897                 clear_bit(DASD_FLAG_OFFLINE, &device->flags);
1898                 dasd_put_device(device);
1899                 return -EBUSY;
1900         }
1901         dasd_set_target_state(device, DASD_STATE_NEW);
1902         /* dasd_delete_device destroys the device reference. */
1903         dasd_delete_device(device);
1904
1905         return 0;
1906 }
1907
1908 int
1909 dasd_generic_notify(struct ccw_device *cdev, int event)
1910 {
1911         struct dasd_device *device;
1912         struct dasd_ccw_req *cqr;
1913         unsigned long flags;
1914         int ret;
1915
1916         device = dasd_device_from_cdev(cdev);
1917         if (IS_ERR(device))
1918                 return 0;
1919         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1920         ret = 0;
1921         switch (event) {
1922         case CIO_GONE:
1923         case CIO_NO_PATH:
1924                 if (device->state < DASD_STATE_BASIC)
1925                         break;
1926                 /* Device is active. We want to keep it. */
1927                 if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
1928                         list_for_each_entry(cqr, &device->ccw_queue, list)
1929                                 if (cqr->status == DASD_CQR_IN_IO)
1930                                         cqr->status = DASD_CQR_FAILED;
1931                         device->stopped |= DASD_STOPPED_DC_EIO;
1932                 } else {
1933                         list_for_each_entry(cqr, &device->ccw_queue, list)
1934                                 if (cqr->status == DASD_CQR_IN_IO) {
1935                                         cqr->status = DASD_CQR_QUEUED;
1936                                         cqr->retries++;
1937                                 }
1938                         device->stopped |= DASD_STOPPED_DC_WAIT;
1939                         dasd_set_timer(device, 0);
1940                 }
1941                 dasd_schedule_bh(device);
1942                 ret = 1;
1943                 break;
1944         case CIO_OPER:
1945                 /* FIXME: add a sanity check. */
1946                 device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
1947                 dasd_schedule_bh(device);
1948                 ret = 1;
1949                 break;
1950         }
1951         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1952         dasd_put_device(device);
1953         return ret;
1954 }
1955
1956 /*
1957  * Automatically online either all dasd devices (dasd_autodetect) or
1958  * all devices specified with dasd= parameters.
1959  */
1960 static int
1961 __dasd_auto_online(struct device *dev, void *data)
1962 {
1963         struct ccw_device *cdev;
1964
1965         cdev = to_ccwdev(dev);
1966         if (dasd_autodetect || dasd_busid_known(cdev->dev.bus_id) == 0)
1967                 ccw_device_set_online(cdev);
1968         return 0;
1969 }
1970
1971 void
1972 dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver)
1973 {
1974         struct device_driver *drv;
1975
1976         drv = get_driver(&dasd_discipline_driver->driver);
1977         driver_for_each_device(drv, NULL, NULL, __dasd_auto_online);
1978         put_driver(drv);
1979 }
1980
1981 static int __init
1982 dasd_init(void)
1983 {
1984         int rc;
1985
1986         init_waitqueue_head(&dasd_init_waitq);
1987
1988         /* register 'common' DASD debug area, used for all DBF_XXX calls */
1989         dasd_debug_area = debug_register("dasd", 1, 2, 8 * sizeof (long));
1990         if (dasd_debug_area == NULL) {
1991                 rc = -ENOMEM;
1992                 goto failed;
1993         }
1994         debug_register_view(dasd_debug_area, &debug_sprintf_view);
1995         debug_set_level(dasd_debug_area, DBF_EMERG);
1996
1997         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
1998
1999         dasd_diag_discipline_pointer = NULL;
2000
2001         rc = devfs_mk_dir("dasd");
2002         if (rc)
2003                 goto failed;
2004         rc = dasd_devmap_init();
2005         if (rc)
2006                 goto failed;
2007         rc = dasd_gendisk_init();
2008         if (rc)
2009                 goto failed;
2010         rc = dasd_parse();
2011         if (rc)
2012                 goto failed;
2013         rc = dasd_ioctl_init();
2014         if (rc)
2015                 goto failed;
2016 #ifdef CONFIG_PROC_FS
2017         rc = dasd_proc_init();
2018         if (rc)
2019                 goto failed;
2020 #endif
2021
2022         return 0;
2023 failed:
2024         MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
2025         dasd_exit();
2026         return rc;
2027 }
2028
2029 module_init(dasd_init);
2030 module_exit(dasd_exit);
2031
2032 EXPORT_SYMBOL(dasd_debug_area);
2033 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
2034
2035 EXPORT_SYMBOL(dasd_add_request_head);
2036 EXPORT_SYMBOL(dasd_add_request_tail);
2037 EXPORT_SYMBOL(dasd_cancel_req);
2038 EXPORT_SYMBOL(dasd_clear_timer);
2039 EXPORT_SYMBOL(dasd_enable_device);
2040 EXPORT_SYMBOL(dasd_int_handler);
2041 EXPORT_SYMBOL(dasd_kfree_request);
2042 EXPORT_SYMBOL(dasd_kick_device);
2043 EXPORT_SYMBOL(dasd_kmalloc_request);
2044 EXPORT_SYMBOL(dasd_schedule_bh);
2045 EXPORT_SYMBOL(dasd_set_target_state);
2046 EXPORT_SYMBOL(dasd_set_timer);
2047 EXPORT_SYMBOL(dasd_sfree_request);
2048 EXPORT_SYMBOL(dasd_sleep_on);
2049 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2050 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2051 EXPORT_SYMBOL(dasd_smalloc_request);
2052 EXPORT_SYMBOL(dasd_start_IO);
2053 EXPORT_SYMBOL(dasd_term_IO);
2054
2055 EXPORT_SYMBOL_GPL(dasd_generic_probe);
2056 EXPORT_SYMBOL_GPL(dasd_generic_remove);
2057 EXPORT_SYMBOL_GPL(dasd_generic_notify);
2058 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
2059 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
2060 EXPORT_SYMBOL_GPL(dasd_generic_auto_online);
2061
2062 /*
2063  * Overrides for Emacs so that we follow Linus's tabbing style.
2064  * Emacs will notice this stuff at the end of the file and automatically
2065  * adjust the settings for this buffer only.  This must remain at the end
2066  * of the file.
2067  * ---------------------------------------------------------------------------
2068  * Local variables:
2069  * c-indent-level: 4
2070  * c-brace-imaginary-offset: 0
2071  * c-brace-offset: -4
2072  * c-argdecl-indent: 4
2073  * c-label-offset: -4
2074  * c-continued-statement-offset: 4
2075  * c-continued-brace-offset: 0
2076  * indent-tabs-mode: 1
2077  * tab-width: 8
2078  * End:
2079  */