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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 *
Horst Hummel6bb0e012005-07-27 11:45:03 -070010 * $Revision: 1.165 $
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 */
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 */
39debug_info_t *dasd_debug_area;
40struct dasd_discipline *dasd_diag_discipline_pointer;
41
42MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
43MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
44 " Copyright 2000 IBM Corporation");
45MODULE_SUPPORTED_DEVICE("dasd");
46MODULE_PARM(dasd, "1-" __MODULE_STRING(256) "s");
47MODULE_LICENSE("GPL");
48
49/*
50 * SECTION: prototypes for static functions of dasd.c
51 */
52static int dasd_alloc_queue(struct dasd_device * device);
53static void dasd_setup_queue(struct dasd_device * device);
54static void dasd_free_queue(struct dasd_device * device);
55static void dasd_flush_request_queue(struct dasd_device *);
56static void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
57static void dasd_flush_ccw_queue(struct dasd_device *, int);
58static void dasd_tasklet(struct dasd_device *);
59static void do_kick_device(void *data);
60
61/*
62 * SECTION: Operations on the device structure.
63 */
64static wait_queue_head_t dasd_init_waitq;
65
66/*
67 * Allocate memory for a new device structure.
68 */
69struct dasd_device *
70dasd_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 */
115void
116dasd_free_device(struct dasd_device *device)
117{
118 if (device->private)
119 kfree(device->private);
120 free_page((unsigned long) device->erp_mem);
121 free_pages((unsigned long) device->ccw_mem, 1);
122 kfree(device);
123}
124
125/*
126 * Make a new device known to the system.
127 */
128static inline int
129dasd_state_new_to_known(struct dasd_device *device)
130{
131 int rc;
132
133 /*
134 * As long as the device is not in state DASD_STATE_NEW we want to
135 * keep the reference count > 0.
136 */
137 dasd_get_device(device);
138
139 rc = dasd_alloc_queue(device);
140 if (rc) {
141 dasd_put_device(device);
142 return rc;
143 }
144
145 device->state = DASD_STATE_KNOWN;
146 return 0;
147}
148
149/*
150 * Let the system forget about a device.
151 */
152static inline void
153dasd_state_known_to_new(struct dasd_device * device)
154{
155 /* Forget the discipline information. */
156 device->discipline = NULL;
157 device->state = DASD_STATE_NEW;
158
159 dasd_free_queue(device);
160
161 /* Give up reference we took in dasd_state_new_to_known. */
162 dasd_put_device(device);
163}
164
165/*
166 * Request the irq line for the device.
167 */
168static inline int
169dasd_state_known_to_basic(struct dasd_device * device)
170{
171 int rc;
172
173 /* Allocate and register gendisk structure. */
174 rc = dasd_gendisk_alloc(device);
175 if (rc)
176 return rc;
177
178 /* register 'device' debug area, used for all DBF_DEV_XXX calls */
Michael Holzheu66a464d2005-06-25 14:55:33 -0700179 device->debug_area = debug_register(device->cdev->dev.bus_id, 1, 2,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 8 * sizeof (long));
181 debug_register_view(device->debug_area, &debug_sprintf_view);
182 debug_set_level(device->debug_area, DBF_EMERG);
183 DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
184
185 device->state = DASD_STATE_BASIC;
186 return 0;
187}
188
189/*
190 * Release the irq line for the device. Terminate any running i/o.
191 */
192static inline void
193dasd_state_basic_to_known(struct dasd_device * device)
194{
195 dasd_gendisk_free(device);
196 dasd_flush_ccw_queue(device, 1);
197 DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
198 if (device->debug_area != NULL) {
199 debug_unregister(device->debug_area);
200 device->debug_area = NULL;
201 }
202 device->state = DASD_STATE_KNOWN;
203}
204
205/*
206 * Do the initial analysis. The do_analysis function may return
207 * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
208 * until the discipline decides to continue the startup sequence
209 * by calling the function dasd_change_state. The eckd disciplines
210 * uses this to start a ccw that detects the format. The completion
211 * interrupt for this detection ccw uses the kernel event daemon to
212 * trigger the call to dasd_change_state. All this is done in the
213 * discipline code, see dasd_eckd.c.
214 * After the analysis ccw is done (do_analysis returned 0 or error)
215 * the block device is setup. Either a fake disk is added to allow
216 * formatting or a proper device request queue is created.
217 */
218static inline int
219dasd_state_basic_to_ready(struct dasd_device * device)
220{
221 int rc;
222
223 rc = 0;
224 if (device->discipline->do_analysis != NULL)
225 rc = device->discipline->do_analysis(device);
226 if (rc)
227 return rc;
228 dasd_setup_queue(device);
229 device->state = DASD_STATE_READY;
230 if (dasd_scan_partitions(device) != 0)
231 device->state = DASD_STATE_BASIC;
232 return 0;
233}
234
235/*
236 * Remove device from block device layer. Destroy dirty buffers.
237 * Forget format information. Check if the target level is basic
238 * and if it is create fake disk for formatting.
239 */
240static inline void
241dasd_state_ready_to_basic(struct dasd_device * device)
242{
243 dasd_flush_ccw_queue(device, 0);
244 dasd_destroy_partitions(device);
245 dasd_flush_request_queue(device);
246 device->blocks = 0;
247 device->bp_block = 0;
248 device->s2b_shift = 0;
249 device->state = DASD_STATE_BASIC;
250}
251
252/*
253 * Make the device online and schedule the bottom half to start
254 * the requeueing of requests from the linux request queue to the
255 * ccw queue.
256 */
257static inline int
258dasd_state_ready_to_online(struct dasd_device * device)
259{
260 device->state = DASD_STATE_ONLINE;
261 dasd_schedule_bh(device);
262 return 0;
263}
264
265/*
266 * Stop the requeueing of requests again.
267 */
268static inline void
269dasd_state_online_to_ready(struct dasd_device * device)
270{
271 device->state = DASD_STATE_READY;
272}
273
274/*
275 * Device startup state changes.
276 */
277static inline int
278dasd_increase_state(struct dasd_device *device)
279{
280 int rc;
281
282 rc = 0;
283 if (device->state == DASD_STATE_NEW &&
284 device->target >= DASD_STATE_KNOWN)
285 rc = dasd_state_new_to_known(device);
286
287 if (!rc &&
288 device->state == DASD_STATE_KNOWN &&
289 device->target >= DASD_STATE_BASIC)
290 rc = dasd_state_known_to_basic(device);
291
292 if (!rc &&
293 device->state == DASD_STATE_BASIC &&
294 device->target >= DASD_STATE_READY)
295 rc = dasd_state_basic_to_ready(device);
296
297 if (!rc &&
298 device->state == DASD_STATE_READY &&
299 device->target >= DASD_STATE_ONLINE)
300 rc = dasd_state_ready_to_online(device);
301
302 return rc;
303}
304
305/*
306 * Device shutdown state changes.
307 */
308static inline int
309dasd_decrease_state(struct dasd_device *device)
310{
311 if (device->state == DASD_STATE_ONLINE &&
312 device->target <= DASD_STATE_READY)
313 dasd_state_online_to_ready(device);
314
315 if (device->state == DASD_STATE_READY &&
316 device->target <= DASD_STATE_BASIC)
317 dasd_state_ready_to_basic(device);
318
319 if (device->state == DASD_STATE_BASIC &&
320 device->target <= DASD_STATE_KNOWN)
321 dasd_state_basic_to_known(device);
322
323 if (device->state == DASD_STATE_KNOWN &&
324 device->target <= DASD_STATE_NEW)
325 dasd_state_known_to_new(device);
326
327 return 0;
328}
329
330/*
331 * This is the main startup/shutdown routine.
332 */
333static void
334dasd_change_state(struct dasd_device *device)
335{
336 int rc;
337
338 if (device->state == device->target)
339 /* Already where we want to go today... */
340 return;
341 if (device->state < device->target)
342 rc = dasd_increase_state(device);
343 else
344 rc = dasd_decrease_state(device);
345 if (rc && rc != -EAGAIN)
346 device->target = device->state;
347
348 if (device->state == device->target)
349 wake_up(&dasd_init_waitq);
350}
351
352/*
353 * Kick starter for devices that did not complete the startup/shutdown
354 * procedure or were sleeping because of a pending state.
355 * dasd_kick_device will schedule a call do do_kick_device to the kernel
356 * event daemon.
357 */
358static void
359do_kick_device(void *data)
360{
361 struct dasd_device *device;
362
363 device = (struct dasd_device *) data;
364 dasd_change_state(device);
365 dasd_schedule_bh(device);
366 dasd_put_device(device);
367}
368
369void
370dasd_kick_device(struct dasd_device *device)
371{
372 dasd_get_device(device);
373 /* queue call to dasd_kick_device to the kernel event daemon. */
374 schedule_work(&device->kick_work);
375}
376
377/*
378 * Set the target state for a device and starts the state change.
379 */
380void
381dasd_set_target_state(struct dasd_device *device, int target)
382{
383 /* If we are in probeonly mode stop at DASD_STATE_READY. */
384 if (dasd_probeonly && target > DASD_STATE_READY)
385 target = DASD_STATE_READY;
386 if (device->target != target) {
387 if (device->state == target)
388 wake_up(&dasd_init_waitq);
389 device->target = target;
390 }
391 if (device->state != device->target)
392 dasd_change_state(device);
393}
394
395/*
396 * Enable devices with device numbers in [from..to].
397 */
398static inline int
399_wait_for_device(struct dasd_device *device)
400{
401 return (device->state == device->target);
402}
403
404void
405dasd_enable_device(struct dasd_device *device)
406{
407 dasd_set_target_state(device, DASD_STATE_ONLINE);
408 if (device->state <= DASD_STATE_KNOWN)
409 /* No discipline for device found. */
410 dasd_set_target_state(device, DASD_STATE_NEW);
411 /* Now wait for the devices to come up. */
412 wait_event(dasd_init_waitq, _wait_for_device(device));
413}
414
415/*
416 * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
417 */
418#ifdef CONFIG_DASD_PROFILE
419
420struct dasd_profile_info_t dasd_global_profile;
421unsigned int dasd_profile_level = DASD_PROFILE_OFF;
422
423/*
424 * Increments counter in global and local profiling structures.
425 */
426#define dasd_profile_counter(value, counter, device) \
427{ \
428 int index; \
429 for (index = 0; index < 31 && value >> (2+index); index++); \
430 dasd_global_profile.counter[index]++; \
431 device->profile.counter[index]++; \
432}
433
434/*
435 * Add profiling information for cqr before execution.
436 */
437static inline void
438dasd_profile_start(struct dasd_device *device, struct dasd_ccw_req * cqr,
439 struct request *req)
440{
441 struct list_head *l;
442 unsigned int counter;
443
444 if (dasd_profile_level != DASD_PROFILE_ON)
445 return;
446
447 /* count the length of the chanq for statistics */
448 counter = 0;
449 list_for_each(l, &device->ccw_queue)
450 if (++counter >= 31)
451 break;
452 dasd_global_profile.dasd_io_nr_req[counter]++;
453 device->profile.dasd_io_nr_req[counter]++;
454}
455
456/*
457 * Add profiling information for cqr after execution.
458 */
459static inline void
460dasd_profile_end(struct dasd_device *device, struct dasd_ccw_req * cqr,
461 struct request *req)
462{
463 long strtime, irqtime, endtime, tottime; /* in microseconds */
464 long tottimeps, sectors;
465
466 if (dasd_profile_level != DASD_PROFILE_ON)
467 return;
468
469 sectors = req->nr_sectors;
470 if (!cqr->buildclk || !cqr->startclk ||
471 !cqr->stopclk || !cqr->endclk ||
472 !sectors)
473 return;
474
475 strtime = ((cqr->startclk - cqr->buildclk) >> 12);
476 irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
477 endtime = ((cqr->endclk - cqr->stopclk) >> 12);
478 tottime = ((cqr->endclk - cqr->buildclk) >> 12);
479 tottimeps = tottime / sectors;
480
481 if (!dasd_global_profile.dasd_io_reqs)
482 memset(&dasd_global_profile, 0,
483 sizeof (struct dasd_profile_info_t));
484 dasd_global_profile.dasd_io_reqs++;
485 dasd_global_profile.dasd_io_sects += sectors;
486
487 if (!device->profile.dasd_io_reqs)
488 memset(&device->profile, 0,
489 sizeof (struct dasd_profile_info_t));
490 device->profile.dasd_io_reqs++;
491 device->profile.dasd_io_sects += sectors;
492
493 dasd_profile_counter(sectors, dasd_io_secs, device);
494 dasd_profile_counter(tottime, dasd_io_times, device);
495 dasd_profile_counter(tottimeps, dasd_io_timps, device);
496 dasd_profile_counter(strtime, dasd_io_time1, device);
497 dasd_profile_counter(irqtime, dasd_io_time2, device);
498 dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, device);
499 dasd_profile_counter(endtime, dasd_io_time3, device);
500}
501#else
502#define dasd_profile_start(device, cqr, req) do {} while (0)
503#define dasd_profile_end(device, cqr, req) do {} while (0)
504#endif /* CONFIG_DASD_PROFILE */
505
506/*
507 * Allocate memory for a channel program with 'cplength' channel
508 * command words and 'datasize' additional space. There are two
509 * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
510 * memory and 2) dasd_smalloc_request uses the static ccw memory
511 * that gets allocated for each device.
512 */
513struct dasd_ccw_req *
514dasd_kmalloc_request(char *magic, int cplength, int datasize,
515 struct dasd_device * device)
516{
517 struct dasd_ccw_req *cqr;
518
519 /* Sanity checks */
520 if ( magic == NULL || datasize > PAGE_SIZE ||
521 (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
522 BUG();
523
524 cqr = kmalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
525 if (cqr == NULL)
526 return ERR_PTR(-ENOMEM);
527 memset(cqr, 0, sizeof(struct dasd_ccw_req));
528 cqr->cpaddr = NULL;
529 if (cplength > 0) {
530 cqr->cpaddr = kmalloc(cplength*sizeof(struct ccw1),
531 GFP_ATOMIC | GFP_DMA);
532 if (cqr->cpaddr == NULL) {
533 kfree(cqr);
534 return ERR_PTR(-ENOMEM);
535 }
536 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
537 }
538 cqr->data = NULL;
539 if (datasize > 0) {
540 cqr->data = kmalloc(datasize, GFP_ATOMIC | GFP_DMA);
541 if (cqr->data == NULL) {
542 if (cqr->cpaddr != NULL)
543 kfree(cqr->cpaddr);
544 kfree(cqr);
545 return ERR_PTR(-ENOMEM);
546 }
547 memset(cqr->data, 0, datasize);
548 }
549 strncpy((char *) &cqr->magic, magic, 4);
550 ASCEBC((char *) &cqr->magic, 4);
551 set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
552 dasd_get_device(device);
553 return cqr;
554}
555
556struct dasd_ccw_req *
557dasd_smalloc_request(char *magic, int cplength, int datasize,
558 struct dasd_device * device)
559{
560 unsigned long flags;
561 struct dasd_ccw_req *cqr;
562 char *data;
563 int size;
564
565 /* Sanity checks */
566 if ( magic == NULL || datasize > PAGE_SIZE ||
567 (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
568 BUG();
569
570 size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
571 if (cplength > 0)
572 size += cplength * sizeof(struct ccw1);
573 if (datasize > 0)
574 size += datasize;
575 spin_lock_irqsave(&device->mem_lock, flags);
576 cqr = (struct dasd_ccw_req *)
577 dasd_alloc_chunk(&device->ccw_chunks, size);
578 spin_unlock_irqrestore(&device->mem_lock, flags);
579 if (cqr == NULL)
580 return ERR_PTR(-ENOMEM);
581 memset(cqr, 0, sizeof(struct dasd_ccw_req));
582 data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
583 cqr->cpaddr = NULL;
584 if (cplength > 0) {
585 cqr->cpaddr = (struct ccw1 *) data;
586 data += cplength*sizeof(struct ccw1);
587 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
588 }
589 cqr->data = NULL;
590 if (datasize > 0) {
591 cqr->data = data;
592 memset(cqr->data, 0, datasize);
593 }
594 strncpy((char *) &cqr->magic, magic, 4);
595 ASCEBC((char *) &cqr->magic, 4);
596 set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
597 dasd_get_device(device);
598 return cqr;
599}
600
601/*
602 * Free memory of a channel program. This function needs to free all the
603 * idal lists that might have been created by dasd_set_cda and the
604 * struct dasd_ccw_req itself.
605 */
606void
607dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
608{
609#ifdef CONFIG_ARCH_S390X
610 struct ccw1 *ccw;
611
612 /* Clear any idals used for the request. */
613 ccw = cqr->cpaddr;
614 do {
615 clear_normalized_cda(ccw);
616 } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
617#endif
618 if (cqr->cpaddr != NULL)
619 kfree(cqr->cpaddr);
620 if (cqr->data != NULL)
621 kfree(cqr->data);
622 kfree(cqr);
623 dasd_put_device(device);
624}
625
626void
627dasd_sfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
628{
629 unsigned long flags;
630
631 spin_lock_irqsave(&device->mem_lock, flags);
632 dasd_free_chunk(&device->ccw_chunks, cqr);
633 spin_unlock_irqrestore(&device->mem_lock, flags);
634 dasd_put_device(device);
635}
636
637/*
638 * Check discipline magic in cqr.
639 */
640static inline int
641dasd_check_cqr(struct dasd_ccw_req *cqr)
642{
643 struct dasd_device *device;
644
645 if (cqr == NULL)
646 return -EINVAL;
647 device = cqr->device;
648 if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
649 DEV_MESSAGE(KERN_WARNING, device,
650 " dasd_ccw_req 0x%08x magic doesn't match"
651 " discipline 0x%08x",
652 cqr->magic,
653 *(unsigned int *) device->discipline->name);
654 return -EINVAL;
655 }
656 return 0;
657}
658
659/*
660 * Terminate the current i/o and set the request to clear_pending.
661 * Timer keeps device runnig.
662 * ccw_device_clear can fail if the i/o subsystem
663 * is in a bad mood.
664 */
665int
666dasd_term_IO(struct dasd_ccw_req * cqr)
667{
668 struct dasd_device *device;
669 int retries, rc;
670
671 /* Check the cqr */
672 rc = dasd_check_cqr(cqr);
673 if (rc)
674 return rc;
675 retries = 0;
676 device = (struct dasd_device *) cqr->device;
677 while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
678 rc = ccw_device_clear(device->cdev, (long) cqr);
679 switch (rc) {
680 case 0: /* termination successful */
681 if (cqr->retries > 0) {
682 cqr->retries--;
683 cqr->status = DASD_CQR_CLEAR;
684 } else
685 cqr->status = DASD_CQR_FAILED;
686 cqr->stopclk = get_clock();
687 DBF_DEV_EVENT(DBF_DEBUG, device,
688 "terminate cqr %p successful",
689 cqr);
690 break;
691 case -ENODEV:
692 DBF_DEV_EVENT(DBF_ERR, device, "%s",
693 "device gone, retry");
694 break;
695 case -EIO:
696 DBF_DEV_EVENT(DBF_ERR, device, "%s",
697 "I/O error, retry");
698 break;
699 case -EINVAL:
700 case -EBUSY:
701 DBF_DEV_EVENT(DBF_ERR, device, "%s",
702 "device busy, retry later");
703 break;
704 default:
705 DEV_MESSAGE(KERN_ERR, device,
706 "line %d unknown RC=%d, please "
707 "report to linux390@de.ibm.com",
708 __LINE__, rc);
709 BUG();
710 break;
711 }
712 retries++;
713 }
714 dasd_schedule_bh(device);
715 return rc;
716}
717
718/*
719 * Start the i/o. This start_IO can fail if the channel is really busy.
720 * In that case set up a timer to start the request later.
721 */
722int
723dasd_start_IO(struct dasd_ccw_req * cqr)
724{
725 struct dasd_device *device;
726 int rc;
727
728 /* Check the cqr */
729 rc = dasd_check_cqr(cqr);
730 if (rc)
731 return rc;
732 device = (struct dasd_device *) cqr->device;
733 if (cqr->retries < 0) {
734 DEV_MESSAGE(KERN_DEBUG, device,
735 "start_IO: request %p (%02x/%i) - no retry left.",
736 cqr, cqr->status, cqr->retries);
737 cqr->status = DASD_CQR_FAILED;
738 return -EIO;
739 }
740 cqr->startclk = get_clock();
741 cqr->starttime = jiffies;
742 cqr->retries--;
743 rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr,
744 cqr->lpm, 0);
745 switch (rc) {
746 case 0:
747 cqr->status = DASD_CQR_IN_IO;
748 DBF_DEV_EVENT(DBF_DEBUG, device,
749 "start_IO: request %p started successful",
750 cqr);
751 break;
752 case -EBUSY:
753 DBF_DEV_EVENT(DBF_ERR, device, "%s",
754 "start_IO: device busy, retry later");
755 break;
756 case -ETIMEDOUT:
757 DBF_DEV_EVENT(DBF_ERR, device, "%s",
758 "start_IO: request timeout, retry later");
759 break;
760 case -EACCES:
761 /* -EACCES indicates that the request used only a
762 * subset of the available pathes and all these
763 * pathes are gone.
764 * Do a retry with all available pathes.
765 */
766 cqr->lpm = LPM_ANYPATH;
767 DBF_DEV_EVENT(DBF_ERR, device, "%s",
768 "start_IO: selected pathes gone,"
769 " retry on all pathes");
770 break;
771 case -ENODEV:
772 case -EIO:
773 DBF_DEV_EVENT(DBF_ERR, device, "%s",
774 "start_IO: device gone, retry");
775 break;
776 default:
777 DEV_MESSAGE(KERN_ERR, device,
778 "line %d unknown RC=%d, please report"
779 " to linux390@de.ibm.com", __LINE__, rc);
780 BUG();
781 break;
782 }
783 return rc;
784}
785
786/*
787 * Timeout function for dasd devices. This is used for different purposes
788 * 1) missing interrupt handler for normal operation
789 * 2) delayed start of request where start_IO failed with -EBUSY
790 * 3) timeout for missing state change interrupts
791 * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
792 * DASD_CQR_QUEUED for 2) and 3).
793 */
794static void
795dasd_timeout_device(unsigned long ptr)
796{
797 unsigned long flags;
798 struct dasd_device *device;
799
800 device = (struct dasd_device *) ptr;
801 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
802 /* re-activate request queue */
803 device->stopped &= ~DASD_STOPPED_PENDING;
804 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
805 dasd_schedule_bh(device);
806}
807
808/*
809 * Setup timeout for a device in jiffies.
810 */
811void
812dasd_set_timer(struct dasd_device *device, int expires)
813{
814 if (expires == 0) {
815 if (timer_pending(&device->timer))
816 del_timer(&device->timer);
817 return;
818 }
819 if (timer_pending(&device->timer)) {
820 if (mod_timer(&device->timer, jiffies + expires))
821 return;
822 }
823 device->timer.function = dasd_timeout_device;
824 device->timer.data = (unsigned long) device;
825 device->timer.expires = jiffies + expires;
826 add_timer(&device->timer);
827}
828
829/*
830 * Clear timeout for a device.
831 */
832void
833dasd_clear_timer(struct dasd_device *device)
834{
835 if (timer_pending(&device->timer))
836 del_timer(&device->timer);
837}
838
839static void
840dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm)
841{
842 struct dasd_ccw_req *cqr;
843 struct dasd_device *device;
844
845 cqr = (struct dasd_ccw_req *) intparm;
846 if (cqr->status != DASD_CQR_IN_IO) {
847 MESSAGE(KERN_DEBUG,
848 "invalid status in handle_killed_request: "
849 "bus_id %s, status %02x",
850 cdev->dev.bus_id, cqr->status);
851 return;
852 }
853
854 device = (struct dasd_device *) cqr->device;
855 if (device == NULL ||
856 device != dasd_device_from_cdev(cdev) ||
857 strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
858 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
859 cdev->dev.bus_id);
860 return;
861 }
862
863 /* Schedule request to be retried. */
864 cqr->status = DASD_CQR_QUEUED;
865
866 dasd_clear_timer(device);
867 dasd_schedule_bh(device);
868 dasd_put_device(device);
869}
870
871static void
872dasd_handle_state_change_pending(struct dasd_device *device)
873{
874 struct dasd_ccw_req *cqr;
875 struct list_head *l, *n;
876
877 device->stopped &= ~DASD_STOPPED_PENDING;
878
879 /* restart all 'running' IO on queue */
880 list_for_each_safe(l, n, &device->ccw_queue) {
881 cqr = list_entry(l, struct dasd_ccw_req, list);
882 if (cqr->status == DASD_CQR_IN_IO) {
883 cqr->status = DASD_CQR_QUEUED;
884 }
885 }
886 dasd_clear_timer(device);
887 dasd_schedule_bh(device);
888}
889
890/*
891 * Interrupt handler for "normal" ssch-io based dasd devices.
892 */
893void
894dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
895 struct irb *irb)
896{
897 struct dasd_ccw_req *cqr, *next;
898 struct dasd_device *device;
899 unsigned long long now;
900 int expires;
901 dasd_era_t era;
902 char mask;
903
904 if (IS_ERR(irb)) {
905 switch (PTR_ERR(irb)) {
906 case -EIO:
907 dasd_handle_killed_request(cdev, intparm);
908 break;
909 case -ETIMEDOUT:
910 printk(KERN_WARNING"%s(%s): request timed out\n",
911 __FUNCTION__, cdev->dev.bus_id);
912 //FIXME - dasd uses own timeout interface...
913 break;
914 default:
915 printk(KERN_WARNING"%s(%s): unknown error %ld\n",
916 __FUNCTION__, cdev->dev.bus_id, PTR_ERR(irb));
917 }
918 return;
919 }
920
921 now = get_clock();
922
923 DBF_EVENT(DBF_ERR, "Interrupt: bus_id %s CS/DS %04x ip %08x",
924 cdev->dev.bus_id, ((irb->scsw.cstat<<8)|irb->scsw.dstat),
925 (unsigned int) intparm);
926
927 /* first of all check for state change pending interrupt */
928 mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
929 if ((irb->scsw.dstat & mask) == mask) {
930 device = dasd_device_from_cdev(cdev);
931 if (!IS_ERR(device)) {
932 dasd_handle_state_change_pending(device);
933 dasd_put_device(device);
934 }
935 return;
936 }
937
938 cqr = (struct dasd_ccw_req *) intparm;
939
940 /* check for unsolicited interrupts */
941 if (cqr == NULL) {
942 MESSAGE(KERN_DEBUG,
943 "unsolicited interrupt received: bus_id %s",
944 cdev->dev.bus_id);
945 return;
946 }
947
948 device = (struct dasd_device *) cqr->device;
949 if (device == NULL ||
950 strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
951 MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
952 cdev->dev.bus_id);
953 return;
954 }
955
956 /* Check for clear pending */
957 if (cqr->status == DASD_CQR_CLEAR &&
958 irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
959 cqr->status = DASD_CQR_QUEUED;
960 dasd_clear_timer(device);
961 dasd_schedule_bh(device);
962 return;
963 }
964
965 /* check status - the request might have been killed by dyn detach */
966 if (cqr->status != DASD_CQR_IN_IO) {
967 MESSAGE(KERN_DEBUG,
968 "invalid status: bus_id %s, status %02x",
969 cdev->dev.bus_id, cqr->status);
970 return;
971 }
972 DBF_DEV_EVENT(DBF_DEBUG, device, "Int: CS/DS 0x%04x for cqr %p",
973 ((irb->scsw.cstat << 8) | irb->scsw.dstat), cqr);
974
975 /* Find out the appropriate era_action. */
976 if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC)
977 era = dasd_era_fatal;
978 else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
979 irb->scsw.cstat == 0 &&
980 !irb->esw.esw0.erw.cons)
981 era = dasd_era_none;
982 else if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags))
983 era = dasd_era_fatal; /* don't recover this request */
984 else if (irb->esw.esw0.erw.cons)
985 era = device->discipline->examine_error(cqr, irb);
986 else
987 era = dasd_era_recover;
988
989 DBF_DEV_EVENT(DBF_DEBUG, device, "era_code %d", era);
990 expires = 0;
991 if (era == dasd_era_none) {
992 cqr->status = DASD_CQR_DONE;
993 cqr->stopclk = now;
994 /* Start first request on queue if possible -> fast_io. */
995 if (cqr->list.next != &device->ccw_queue) {
996 next = list_entry(cqr->list.next,
997 struct dasd_ccw_req, list);
998 if ((next->status == DASD_CQR_QUEUED) &&
999 (!device->stopped)) {
1000 if (device->discipline->start_IO(next) == 0)
1001 expires = next->expires;
1002 else
1003 DEV_MESSAGE(KERN_DEBUG, device, "%s",
1004 "Interrupt fastpath "
1005 "failed!");
1006 }
1007 }
1008 } else { /* error */
1009 memcpy(&cqr->irb, irb, sizeof (struct irb));
1010#ifdef ERP_DEBUG
1011 /* dump sense data */
1012 dasd_log_sense(cqr, irb);
1013#endif
1014 switch (era) {
1015 case dasd_era_fatal:
1016 cqr->status = DASD_CQR_FAILED;
1017 cqr->stopclk = now;
1018 break;
1019 case dasd_era_recover:
1020 cqr->status = DASD_CQR_ERROR;
1021 break;
1022 default:
1023 BUG();
1024 }
1025 }
1026 if (expires != 0)
1027 dasd_set_timer(device, expires);
1028 else
1029 dasd_clear_timer(device);
1030 dasd_schedule_bh(device);
1031}
1032
1033/*
1034 * posts the buffer_cache about a finalized request
1035 */
1036static inline void
1037dasd_end_request(struct request *req, int uptodate)
1038{
1039 if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
1040 BUG();
1041 add_disk_randomness(req->rq_disk);
1042 end_that_request_last(req);
1043}
1044
1045/*
1046 * Process finished error recovery ccw.
1047 */
1048static inline void
1049__dasd_process_erp(struct dasd_device *device, struct dasd_ccw_req *cqr)
1050{
1051 dasd_erp_fn_t erp_fn;
1052
1053 if (cqr->status == DASD_CQR_DONE)
1054 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
1055 else
1056 DEV_MESSAGE(KERN_ERR, device, "%s", "ERP unsuccessful");
1057 erp_fn = device->discipline->erp_postaction(cqr);
1058 erp_fn(cqr);
1059}
1060
1061/*
1062 * Process ccw request queue.
1063 */
1064static inline void
1065__dasd_process_ccw_queue(struct dasd_device * device,
1066 struct list_head *final_queue)
1067{
1068 struct list_head *l, *n;
1069 struct dasd_ccw_req *cqr;
1070 dasd_erp_fn_t erp_fn;
1071
1072restart:
1073 /* Process request with final status. */
1074 list_for_each_safe(l, n, &device->ccw_queue) {
1075 cqr = list_entry(l, struct dasd_ccw_req, list);
1076 /* Stop list processing at the first non-final request. */
1077 if (cqr->status != DASD_CQR_DONE &&
1078 cqr->status != DASD_CQR_FAILED &&
1079 cqr->status != DASD_CQR_ERROR)
1080 break;
1081 /* Process requests with DASD_CQR_ERROR */
1082 if (cqr->status == DASD_CQR_ERROR) {
1083 if (cqr->irb.scsw.fctl & SCSW_FCTL_HALT_FUNC) {
1084 cqr->status = DASD_CQR_FAILED;
1085 cqr->stopclk = get_clock();
1086 } else {
1087 if (cqr->irb.esw.esw0.erw.cons) {
1088 erp_fn = device->discipline->
1089 erp_action(cqr);
1090 erp_fn(cqr);
1091 } else
1092 dasd_default_erp_action(cqr);
1093 }
1094 goto restart;
1095 }
1096 /* Process finished ERP request. */
1097 if (cqr->refers) {
1098 __dasd_process_erp(device, cqr);
1099 goto restart;
1100 }
1101
1102 /* Rechain finished requests to final queue */
1103 cqr->endclk = get_clock();
1104 list_move_tail(&cqr->list, final_queue);
1105 }
1106}
1107
1108static void
1109dasd_end_request_cb(struct dasd_ccw_req * cqr, void *data)
1110{
1111 struct request *req;
1112 struct dasd_device *device;
1113 int status;
1114
1115 req = (struct request *) data;
1116 device = cqr->device;
1117 dasd_profile_end(device, cqr, req);
1118 status = cqr->device->discipline->free_cp(cqr,req);
1119 spin_lock_irq(&device->request_queue_lock);
1120 dasd_end_request(req, status);
1121 spin_unlock_irq(&device->request_queue_lock);
1122}
1123
1124
1125/*
1126 * Fetch requests from the block device queue.
1127 */
1128static inline void
1129__dasd_process_blk_queue(struct dasd_device * device)
1130{
1131 request_queue_t *queue;
1132 struct request *req;
1133 struct dasd_ccw_req *cqr;
Horst Hummelf24acd42005-05-01 08:58:59 -07001134 int nr_queued, feature_ro;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001135
1136 queue = device->request_queue;
1137 /* No queue ? Then there is nothing to do. */
1138 if (queue == NULL)
1139 return;
1140
Horst Hummelf24acd42005-05-01 08:58:59 -07001141 feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
1142 if (feature_ro < 0) /* no devmap */
1143 return;
1144
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145 /*
1146 * We requeue request from the block device queue to the ccw
1147 * queue only in two states. In state DASD_STATE_READY the
1148 * partition detection is done and we need to requeue requests
1149 * for that. State DASD_STATE_ONLINE is normal block device
1150 * operation.
1151 */
1152 if (device->state != DASD_STATE_READY &&
1153 device->state != DASD_STATE_ONLINE)
1154 return;
1155 nr_queued = 0;
1156 /* Now we try to fetch requests from the request queue */
1157 list_for_each_entry(cqr, &device->ccw_queue, list)
1158 if (cqr->status == DASD_CQR_QUEUED)
1159 nr_queued++;
1160 while (!blk_queue_plugged(queue) &&
1161 elv_next_request(queue) &&
1162 nr_queued < DASD_CHANQ_MAX_SIZE) {
1163 req = elv_next_request(queue);
Horst Hummelf24acd42005-05-01 08:58:59 -07001164
1165 if (feature_ro && rq_data_dir(req) == WRITE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001166 DBF_DEV_EVENT(DBF_ERR, device,
1167 "Rejecting write request %p",
1168 req);
1169 blkdev_dequeue_request(req);
1170 dasd_end_request(req, 0);
1171 continue;
1172 }
1173 if (device->stopped & DASD_STOPPED_DC_EIO) {
1174 blkdev_dequeue_request(req);
1175 dasd_end_request(req, 0);
1176 continue;
1177 }
1178 cqr = device->discipline->build_cp(device, req);
1179 if (IS_ERR(cqr)) {
1180 if (PTR_ERR(cqr) == -ENOMEM)
1181 break; /* terminate request queue loop */
1182 DBF_DEV_EVENT(DBF_ERR, device,
1183 "CCW creation failed (rc=%ld) "
1184 "on request %p",
1185 PTR_ERR(cqr), req);
1186 blkdev_dequeue_request(req);
1187 dasd_end_request(req, 0);
1188 continue;
1189 }
1190 cqr->callback = dasd_end_request_cb;
1191 cqr->callback_data = (void *) req;
1192 cqr->status = DASD_CQR_QUEUED;
1193 blkdev_dequeue_request(req);
1194 list_add_tail(&cqr->list, &device->ccw_queue);
1195 dasd_profile_start(device, cqr, req);
1196 nr_queued++;
1197 }
1198}
1199
1200/*
1201 * Take a look at the first request on the ccw queue and check
1202 * if it reached its expire time. If so, terminate the IO.
1203 */
1204static inline void
1205__dasd_check_expire(struct dasd_device * device)
1206{
1207 struct dasd_ccw_req *cqr;
1208
1209 if (list_empty(&device->ccw_queue))
1210 return;
1211 cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1212 if (cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) {
1213 if (time_after_eq(jiffies, cqr->expires + cqr->starttime)) {
1214 if (device->discipline->term_IO(cqr) != 0)
1215 /* Hmpf, try again in 1/10 sec */
1216 dasd_set_timer(device, 10);
1217 }
1218 }
1219}
1220
1221/*
1222 * Take a look at the first request on the ccw queue and check
1223 * if it needs to be started.
1224 */
1225static inline void
1226__dasd_start_head(struct dasd_device * device)
1227{
1228 struct dasd_ccw_req *cqr;
1229 int rc;
1230
1231 if (list_empty(&device->ccw_queue))
1232 return;
1233 cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1234 if ((cqr->status == DASD_CQR_QUEUED) &&
1235 (!device->stopped)) {
1236 /* try to start the first I/O that can be started */
1237 rc = device->discipline->start_IO(cqr);
1238 if (rc == 0)
1239 dasd_set_timer(device, cqr->expires);
1240 else if (rc == -EACCES) {
1241 dasd_schedule_bh(device);
1242 } else
1243 /* Hmpf, try again in 1/2 sec */
1244 dasd_set_timer(device, 50);
1245 }
1246}
1247
1248/*
1249 * Remove requests from the ccw queue.
1250 */
1251static void
1252dasd_flush_ccw_queue(struct dasd_device * device, int all)
1253{
1254 struct list_head flush_queue;
1255 struct list_head *l, *n;
1256 struct dasd_ccw_req *cqr;
1257
1258 INIT_LIST_HEAD(&flush_queue);
1259 spin_lock_irq(get_ccwdev_lock(device->cdev));
1260 list_for_each_safe(l, n, &device->ccw_queue) {
1261 cqr = list_entry(l, struct dasd_ccw_req, list);
1262 /* Flush all request or only block device requests? */
1263 if (all == 0 && cqr->callback == dasd_end_request_cb)
1264 continue;
1265 if (cqr->status == DASD_CQR_IN_IO)
1266 device->discipline->term_IO(cqr);
1267 if (cqr->status != DASD_CQR_DONE ||
1268 cqr->status != DASD_CQR_FAILED) {
1269 cqr->status = DASD_CQR_FAILED;
1270 cqr->stopclk = get_clock();
1271 }
1272 /* Process finished ERP request. */
1273 if (cqr->refers) {
1274 __dasd_process_erp(device, cqr);
1275 continue;
1276 }
1277 /* Rechain request on device request queue */
1278 cqr->endclk = get_clock();
1279 list_move_tail(&cqr->list, &flush_queue);
1280 }
1281 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1282 /* Now call the callback function of flushed requests */
1283 list_for_each_safe(l, n, &flush_queue) {
1284 cqr = list_entry(l, struct dasd_ccw_req, list);
1285 if (cqr->callback != NULL)
1286 (cqr->callback)(cqr, cqr->callback_data);
1287 }
1288}
1289
1290/*
1291 * Acquire the device lock and process queues for the device.
1292 */
1293static void
1294dasd_tasklet(struct dasd_device * device)
1295{
1296 struct list_head final_queue;
1297 struct list_head *l, *n;
1298 struct dasd_ccw_req *cqr;
1299
1300 atomic_set (&device->tasklet_scheduled, 0);
1301 INIT_LIST_HEAD(&final_queue);
1302 spin_lock_irq(get_ccwdev_lock(device->cdev));
1303 /* Check expire time of first request on the ccw queue. */
1304 __dasd_check_expire(device);
1305 /* Finish off requests on ccw queue */
1306 __dasd_process_ccw_queue(device, &final_queue);
1307 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1308 /* Now call the callback function of requests with final status */
1309 list_for_each_safe(l, n, &final_queue) {
1310 cqr = list_entry(l, struct dasd_ccw_req, list);
1311 list_del(&cqr->list);
1312 if (cqr->callback != NULL)
1313 (cqr->callback)(cqr, cqr->callback_data);
1314 }
1315 spin_lock_irq(&device->request_queue_lock);
1316 spin_lock(get_ccwdev_lock(device->cdev));
1317 /* Get new request from the block device request queue */
1318 __dasd_process_blk_queue(device);
1319 /* Now check if the head of the ccw queue needs to be started. */
1320 __dasd_start_head(device);
1321 spin_unlock(get_ccwdev_lock(device->cdev));
1322 spin_unlock_irq(&device->request_queue_lock);
1323 dasd_put_device(device);
1324}
1325
1326/*
1327 * Schedules a call to dasd_tasklet over the device tasklet.
1328 */
1329void
1330dasd_schedule_bh(struct dasd_device * device)
1331{
1332 /* Protect against rescheduling. */
1333 if (atomic_compare_and_swap (0, 1, &device->tasklet_scheduled))
1334 return;
1335 dasd_get_device(device);
1336 tasklet_hi_schedule(&device->tasklet);
1337}
1338
1339/*
1340 * Queue a request to the head of the ccw_queue. Start the I/O if
1341 * possible.
1342 */
1343void
1344dasd_add_request_head(struct dasd_ccw_req *req)
1345{
1346 struct dasd_device *device;
1347 unsigned long flags;
1348
1349 device = req->device;
1350 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1351 req->status = DASD_CQR_QUEUED;
1352 req->device = device;
1353 list_add(&req->list, &device->ccw_queue);
1354 /* let the bh start the request to keep them in order */
1355 dasd_schedule_bh(device);
1356 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1357}
1358
1359/*
1360 * Queue a request to the tail of the ccw_queue. Start the I/O if
1361 * possible.
1362 */
1363void
1364dasd_add_request_tail(struct dasd_ccw_req *req)
1365{
1366 struct dasd_device *device;
1367 unsigned long flags;
1368
1369 device = req->device;
1370 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1371 req->status = DASD_CQR_QUEUED;
1372 req->device = device;
1373 list_add_tail(&req->list, &device->ccw_queue);
1374 /* let the bh start the request to keep them in order */
1375 dasd_schedule_bh(device);
1376 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1377}
1378
1379/*
1380 * Wakeup callback.
1381 */
1382static void
1383dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
1384{
1385 wake_up((wait_queue_head_t *) data);
1386}
1387
1388static inline int
1389_wait_for_wakeup(struct dasd_ccw_req *cqr)
1390{
1391 struct dasd_device *device;
1392 int rc;
1393
1394 device = cqr->device;
1395 spin_lock_irq(get_ccwdev_lock(device->cdev));
1396 rc = cqr->status == DASD_CQR_DONE || cqr->status == DASD_CQR_FAILED;
1397 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1398 return rc;
1399}
1400
1401/*
1402 * Attempts to start a special ccw queue and waits for its completion.
1403 */
1404int
1405dasd_sleep_on(struct dasd_ccw_req * cqr)
1406{
1407 wait_queue_head_t wait_q;
1408 struct dasd_device *device;
1409 int rc;
1410
1411 device = cqr->device;
1412 spin_lock_irq(get_ccwdev_lock(device->cdev));
1413
1414 init_waitqueue_head (&wait_q);
1415 cqr->callback = dasd_wakeup_cb;
1416 cqr->callback_data = (void *) &wait_q;
1417 cqr->status = DASD_CQR_QUEUED;
1418 list_add_tail(&cqr->list, &device->ccw_queue);
1419
1420 /* let the bh start the request to keep them in order */
1421 dasd_schedule_bh(device);
1422
1423 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1424
1425 wait_event(wait_q, _wait_for_wakeup(cqr));
1426
1427 /* Request status is either done or failed. */
1428 rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1429 return rc;
1430}
1431
1432/*
1433 * Attempts to start a special ccw queue and wait interruptible
1434 * for its completion.
1435 */
1436int
1437dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
1438{
1439 wait_queue_head_t wait_q;
1440 struct dasd_device *device;
1441 int rc, finished;
1442
1443 device = cqr->device;
1444 spin_lock_irq(get_ccwdev_lock(device->cdev));
1445
1446 init_waitqueue_head (&wait_q);
1447 cqr->callback = dasd_wakeup_cb;
1448 cqr->callback_data = (void *) &wait_q;
1449 cqr->status = DASD_CQR_QUEUED;
1450 list_add_tail(&cqr->list, &device->ccw_queue);
1451
1452 /* let the bh start the request to keep them in order */
1453 dasd_schedule_bh(device);
1454 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1455
1456 finished = 0;
1457 while (!finished) {
1458 rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
1459 if (rc != -ERESTARTSYS) {
1460 /* Request status is either done or failed. */
1461 rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1462 break;
1463 }
1464 spin_lock_irq(get_ccwdev_lock(device->cdev));
1465 if (cqr->status == DASD_CQR_IN_IO &&
1466 device->discipline->term_IO(cqr) == 0) {
1467 list_del(&cqr->list);
1468 finished = 1;
1469 }
1470 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1471 }
1472 return rc;
1473}
1474
1475/*
1476 * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
1477 * for eckd devices) the currently running request has to be terminated
1478 * and be put back to status queued, before the special request is added
1479 * to the head of the queue. Then the special request is waited on normally.
1480 */
1481static inline int
1482_dasd_term_running_cqr(struct dasd_device *device)
1483{
1484 struct dasd_ccw_req *cqr;
1485 int rc;
1486
1487 if (list_empty(&device->ccw_queue))
1488 return 0;
1489 cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1490 rc = device->discipline->term_IO(cqr);
1491 if (rc == 0) {
1492 /* termination successful */
1493 cqr->status = DASD_CQR_QUEUED;
1494 cqr->startclk = cqr->stopclk = 0;
1495 cqr->starttime = 0;
1496 }
1497 return rc;
1498}
1499
1500int
1501dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
1502{
1503 wait_queue_head_t wait_q;
1504 struct dasd_device *device;
1505 int rc;
1506
1507 device = cqr->device;
1508 spin_lock_irq(get_ccwdev_lock(device->cdev));
1509 rc = _dasd_term_running_cqr(device);
1510 if (rc) {
1511 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1512 return rc;
1513 }
1514
1515 init_waitqueue_head (&wait_q);
1516 cqr->callback = dasd_wakeup_cb;
1517 cqr->callback_data = (void *) &wait_q;
1518 cqr->status = DASD_CQR_QUEUED;
1519 list_add(&cqr->list, &device->ccw_queue);
1520
1521 /* let the bh start the request to keep them in order */
1522 dasd_schedule_bh(device);
1523
1524 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1525
1526 wait_event(wait_q, _wait_for_wakeup(cqr));
1527
1528 /* Request status is either done or failed. */
1529 rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1530 return rc;
1531}
1532
1533/*
1534 * Cancels a request that was started with dasd_sleep_on_req.
1535 * This is useful to timeout requests. The request will be
1536 * terminated if it is currently in i/o.
1537 * Returns 1 if the request has been terminated.
1538 */
1539int
1540dasd_cancel_req(struct dasd_ccw_req *cqr)
1541{
1542 struct dasd_device *device = cqr->device;
1543 unsigned long flags;
1544 int rc;
1545
1546 rc = 0;
1547 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1548 switch (cqr->status) {
1549 case DASD_CQR_QUEUED:
1550 /* request was not started - just set to failed */
1551 cqr->status = DASD_CQR_FAILED;
1552 break;
1553 case DASD_CQR_IN_IO:
1554 /* request in IO - terminate IO and release again */
1555 if (device->discipline->term_IO(cqr) != 0)
1556 /* what to do if unable to terminate ??????
1557 e.g. not _IN_IO */
1558 cqr->status = DASD_CQR_FAILED;
1559 cqr->stopclk = get_clock();
1560 rc = 1;
1561 break;
1562 case DASD_CQR_DONE:
1563 case DASD_CQR_FAILED:
1564 /* already finished - do nothing */
1565 break;
1566 default:
1567 DEV_MESSAGE(KERN_ALERT, device,
1568 "invalid status %02x in request",
1569 cqr->status);
1570 BUG();
1571
1572 }
1573 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1574 dasd_schedule_bh(device);
1575 return rc;
1576}
1577
1578/*
1579 * SECTION: Block device operations (request queue, partitions, open, release).
1580 */
1581
1582/*
1583 * Dasd request queue function. Called from ll_rw_blk.c
1584 */
1585static void
1586do_dasd_request(request_queue_t * queue)
1587{
1588 struct dasd_device *device;
1589
1590 device = (struct dasd_device *) queue->queuedata;
1591 spin_lock(get_ccwdev_lock(device->cdev));
1592 /* Get new request from the block device request queue */
1593 __dasd_process_blk_queue(device);
1594 /* Now check if the head of the ccw queue needs to be started. */
1595 __dasd_start_head(device);
1596 spin_unlock(get_ccwdev_lock(device->cdev));
1597}
1598
1599/*
1600 * Allocate and initialize request queue and default I/O scheduler.
1601 */
1602static int
1603dasd_alloc_queue(struct dasd_device * device)
1604{
1605 int rc;
1606
1607 device->request_queue = blk_init_queue(do_dasd_request,
1608 &device->request_queue_lock);
1609 if (device->request_queue == NULL)
1610 return -ENOMEM;
1611
1612 device->request_queue->queuedata = device;
1613
1614 elevator_exit(device->request_queue->elevator);
1615 rc = elevator_init(device->request_queue, "deadline");
1616 if (rc) {
1617 blk_cleanup_queue(device->request_queue);
1618 return rc;
1619 }
1620 return 0;
1621}
1622
1623/*
1624 * Allocate and initialize request queue.
1625 */
1626static void
1627dasd_setup_queue(struct dasd_device * device)
1628{
1629 int max;
1630
1631 blk_queue_hardsect_size(device->request_queue, device->bp_block);
1632 max = device->discipline->max_blocks << device->s2b_shift;
1633 blk_queue_max_sectors(device->request_queue, max);
1634 blk_queue_max_phys_segments(device->request_queue, -1L);
1635 blk_queue_max_hw_segments(device->request_queue, -1L);
1636 blk_queue_max_segment_size(device->request_queue, -1L);
1637 blk_queue_segment_boundary(device->request_queue, -1L);
Stefan Weinhuber6ed93c82005-05-01 08:58:59 -07001638 blk_queue_ordered(device->request_queue, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001639}
1640
1641/*
1642 * Deactivate and free request queue.
1643 */
1644static void
1645dasd_free_queue(struct dasd_device * device)
1646{
1647 if (device->request_queue) {
1648 blk_cleanup_queue(device->request_queue);
1649 device->request_queue = NULL;
1650 }
1651}
1652
1653/*
1654 * Flush request on the request queue.
1655 */
1656static void
1657dasd_flush_request_queue(struct dasd_device * device)
1658{
1659 struct request *req;
1660
1661 if (!device->request_queue)
1662 return;
1663
1664 spin_lock_irq(&device->request_queue_lock);
1665 while (!list_empty(&device->request_queue->queue_head)) {
1666 req = elv_next_request(device->request_queue);
1667 if (req == NULL)
1668 break;
1669 dasd_end_request(req, 0);
1670 blkdev_dequeue_request(req);
1671 }
1672 spin_unlock_irq(&device->request_queue_lock);
1673}
1674
1675static int
1676dasd_open(struct inode *inp, struct file *filp)
1677{
1678 struct gendisk *disk = inp->i_bdev->bd_disk;
1679 struct dasd_device *device = disk->private_data;
1680 int rc;
1681
1682 atomic_inc(&device->open_count);
1683 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1684 rc = -ENODEV;
1685 goto unlock;
1686 }
1687
1688 if (!try_module_get(device->discipline->owner)) {
1689 rc = -EINVAL;
1690 goto unlock;
1691 }
1692
1693 if (dasd_probeonly) {
1694 DEV_MESSAGE(KERN_INFO, device, "%s",
1695 "No access to device due to probeonly mode");
1696 rc = -EPERM;
1697 goto out;
1698 }
1699
1700 if (device->state < DASD_STATE_BASIC) {
1701 DBF_DEV_EVENT(DBF_ERR, device, " %s",
1702 " Cannot open unrecognized device");
1703 rc = -ENODEV;
1704 goto out;
1705 }
1706
1707 return 0;
1708
1709out:
1710 module_put(device->discipline->owner);
1711unlock:
1712 atomic_dec(&device->open_count);
1713 return rc;
1714}
1715
1716static int
1717dasd_release(struct inode *inp, struct file *filp)
1718{
1719 struct gendisk *disk = inp->i_bdev->bd_disk;
1720 struct dasd_device *device = disk->private_data;
1721
1722 atomic_dec(&device->open_count);
1723 module_put(device->discipline->owner);
1724 return 0;
1725}
1726
1727struct block_device_operations
1728dasd_device_operations = {
1729 .owner = THIS_MODULE,
1730 .open = dasd_open,
1731 .release = dasd_release,
1732 .ioctl = dasd_ioctl,
1733};
1734
1735
1736static void
1737dasd_exit(void)
1738{
1739#ifdef CONFIG_PROC_FS
1740 dasd_proc_exit();
1741#endif
1742 dasd_ioctl_exit();
Horst Hummel6bb0e012005-07-27 11:45:03 -07001743 if (dasd_page_cache != NULL) {
1744 kmem_cache_destroy(dasd_page_cache);
1745 dasd_page_cache = NULL;
1746 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001747 dasd_gendisk_exit();
1748 dasd_devmap_exit();
1749 devfs_remove("dasd");
1750 if (dasd_debug_area != NULL) {
1751 debug_unregister(dasd_debug_area);
1752 dasd_debug_area = NULL;
1753 }
1754}
1755
1756/*
1757 * SECTION: common functions for ccw_driver use
1758 */
1759
1760/* initial attempt at a probe function. this can be simplified once
1761 * the other detection code is gone */
1762int
1763dasd_generic_probe (struct ccw_device *cdev,
1764 struct dasd_discipline *discipline)
1765{
1766 int ret;
1767
1768 ret = dasd_add_sysfs_files(cdev);
1769 if (ret) {
1770 printk(KERN_WARNING
1771 "dasd_generic_probe: could not add sysfs entries "
1772 "for %s\n", cdev->dev.bus_id);
Horst Hummel59afda72005-05-16 21:53:39 -07001773 } else {
1774 cdev->handler = &dasd_int_handler;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001775 }
1776
Linus Torvalds1da177e2005-04-16 15:20:36 -07001777 return ret;
1778}
1779
1780/* this will one day be called from a global not_oper handler.
1781 * It is also used by driver_unregister during module unload */
1782void
1783dasd_generic_remove (struct ccw_device *cdev)
1784{
1785 struct dasd_device *device;
1786
Horst Hummel59afda72005-05-16 21:53:39 -07001787 cdev->handler = NULL;
1788
Linus Torvalds1da177e2005-04-16 15:20:36 -07001789 dasd_remove_sysfs_files(cdev);
1790 device = dasd_device_from_cdev(cdev);
1791 if (IS_ERR(device))
1792 return;
1793 if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1794 /* Already doing offline processing */
1795 dasd_put_device(device);
1796 return;
1797 }
1798 /*
1799 * This device is removed unconditionally. Set offline
1800 * flag to prevent dasd_open from opening it while it is
1801 * no quite down yet.
1802 */
1803 dasd_set_target_state(device, DASD_STATE_NEW);
1804 /* dasd_delete_device destroys the device reference. */
1805 dasd_delete_device(device);
1806}
1807
1808/* activate a device. This is called from dasd_{eckd,fba}_probe() when either
1809 * the device is detected for the first time and is supposed to be used
1810 * or the user has started activation through sysfs */
1811int
1812dasd_generic_set_online (struct ccw_device *cdev,
1813 struct dasd_discipline *discipline)
1814
1815{
1816 struct dasd_device *device;
Horst Hummelf24acd42005-05-01 08:58:59 -07001817 int feature_diag, rc;
1818
Linus Torvalds1da177e2005-04-16 15:20:36 -07001819 device = dasd_create_device(cdev);
1820 if (IS_ERR(device))
1821 return PTR_ERR(device);
1822
Horst Hummel59afda72005-05-16 21:53:39 -07001823 feature_diag = dasd_get_feature(cdev, DASD_FEATURE_USEDIAG);
1824 if (feature_diag < 0)
1825 return feature_diag;
1826
Horst Hummelf24acd42005-05-01 08:58:59 -07001827 if (feature_diag) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001828 if (!dasd_diag_discipline_pointer) {
1829 printk (KERN_WARNING
1830 "dasd_generic couldn't online device %s "
1831 "- discipline DIAG not available\n",
1832 cdev->dev.bus_id);
1833 dasd_delete_device(device);
1834 return -ENODEV;
1835 }
1836 discipline = dasd_diag_discipline_pointer;
1837 }
1838 device->discipline = discipline;
1839
1840 rc = discipline->check_device(device);
1841 if (rc) {
1842 printk (KERN_WARNING
1843 "dasd_generic couldn't online device %s "
1844 "with discipline %s rc=%i\n",
1845 cdev->dev.bus_id, discipline->name, rc);
1846 dasd_delete_device(device);
1847 return rc;
1848 }
1849
1850 dasd_set_target_state(device, DASD_STATE_ONLINE);
1851 if (device->state <= DASD_STATE_KNOWN) {
1852 printk (KERN_WARNING
1853 "dasd_generic discipline not found for %s\n",
1854 cdev->dev.bus_id);
1855 rc = -ENODEV;
1856 dasd_set_target_state(device, DASD_STATE_NEW);
1857 dasd_delete_device(device);
1858 } else
1859 pr_debug("dasd_generic device %s found\n",
1860 cdev->dev.bus_id);
1861
1862 /* FIXME: we have to wait for the root device but we don't want
1863 * to wait for each single device but for all at once. */
1864 wait_event(dasd_init_waitq, _wait_for_device(device));
1865
1866 dasd_put_device(device);
1867
1868 return rc;
1869}
1870
1871int
1872dasd_generic_set_offline (struct ccw_device *cdev)
1873{
1874 struct dasd_device *device;
1875 int max_count;
1876
1877 device = dasd_device_from_cdev(cdev);
1878 if (IS_ERR(device))
1879 return PTR_ERR(device);
1880 if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1881 /* Already doing offline processing */
1882 dasd_put_device(device);
1883 return 0;
1884 }
1885 /*
1886 * We must make sure that this device is currently not in use.
1887 * The open_count is increased for every opener, that includes
1888 * the blkdev_get in dasd_scan_partitions. We are only interested
1889 * in the other openers.
1890 */
1891 max_count = device->bdev ? 0 : -1;
1892 if (atomic_read(&device->open_count) > max_count) {
1893 printk (KERN_WARNING "Can't offline dasd device with open"
1894 " count = %i.\n",
1895 atomic_read(&device->open_count));
1896 clear_bit(DASD_FLAG_OFFLINE, &device->flags);
1897 dasd_put_device(device);
1898 return -EBUSY;
1899 }
1900 dasd_set_target_state(device, DASD_STATE_NEW);
1901 /* dasd_delete_device destroys the device reference. */
1902 dasd_delete_device(device);
1903
1904 return 0;
1905}
1906
1907int
1908dasd_generic_notify(struct ccw_device *cdev, int event)
1909{
1910 struct dasd_device *device;
1911 struct dasd_ccw_req *cqr;
1912 unsigned long flags;
1913 int ret;
1914
1915 device = dasd_device_from_cdev(cdev);
1916 if (IS_ERR(device))
1917 return 0;
1918 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1919 ret = 0;
1920 switch (event) {
1921 case CIO_GONE:
1922 case CIO_NO_PATH:
1923 if (device->state < DASD_STATE_BASIC)
1924 break;
1925 /* Device is active. We want to keep it. */
1926 if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
1927 list_for_each_entry(cqr, &device->ccw_queue, list)
1928 if (cqr->status == DASD_CQR_IN_IO)
1929 cqr->status = DASD_CQR_FAILED;
1930 device->stopped |= DASD_STOPPED_DC_EIO;
1931 dasd_schedule_bh(device);
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 ret = 1;
1942 break;
1943 case CIO_OPER:
1944 /* FIXME: add a sanity check. */
1945 device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
1946 dasd_schedule_bh(device);
1947 ret = 1;
1948 break;
1949 }
1950 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1951 dasd_put_device(device);
1952 return ret;
1953}
1954
1955/*
1956 * Automatically online either all dasd devices (dasd_autodetect) or
1957 * all devices specified with dasd= parameters.
1958 */
Cornelia Huckc5512882005-06-25 14:55:28 -07001959static int
1960__dasd_auto_online(struct device *dev, void *data)
1961{
1962 struct ccw_device *cdev;
1963
1964 cdev = to_ccwdev(dev);
1965 if (dasd_autodetect || dasd_busid_known(cdev->dev.bus_id) == 0)
1966 ccw_device_set_online(cdev);
1967 return 0;
1968}
1969
Linus Torvalds1da177e2005-04-16 15:20:36 -07001970void
1971dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver)
1972{
1973 struct device_driver *drv;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001974
1975 drv = get_driver(&dasd_discipline_driver->driver);
Cornelia Huckc5512882005-06-25 14:55:28 -07001976 driver_for_each_device(drv, NULL, NULL, __dasd_auto_online);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001977 put_driver(drv);
1978}
1979
1980static int __init
1981dasd_init(void)
1982{
1983 int rc;
1984
1985 init_waitqueue_head(&dasd_init_waitq);
1986
1987 /* register 'common' DASD debug area, used for all DBF_XXX calls */
Michael Holzheu66a464d2005-06-25 14:55:33 -07001988 dasd_debug_area = debug_register("dasd", 1, 2, 8 * sizeof (long));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001989 if (dasd_debug_area == NULL) {
1990 rc = -ENOMEM;
1991 goto failed;
1992 }
1993 debug_register_view(dasd_debug_area, &debug_sprintf_view);
1994 debug_set_level(dasd_debug_area, DBF_EMERG);
1995
1996 DBF_EVENT(DBF_EMERG, "%s", "debug area created");
1997
1998 dasd_diag_discipline_pointer = NULL;
1999
2000 rc = devfs_mk_dir("dasd");
2001 if (rc)
2002 goto failed;
2003 rc = dasd_devmap_init();
2004 if (rc)
2005 goto failed;
2006 rc = dasd_gendisk_init();
2007 if (rc)
2008 goto failed;
2009 rc = dasd_parse();
2010 if (rc)
2011 goto failed;
2012 rc = dasd_ioctl_init();
2013 if (rc)
2014 goto failed;
2015#ifdef CONFIG_PROC_FS
2016 rc = dasd_proc_init();
2017 if (rc)
2018 goto failed;
2019#endif
2020
2021 return 0;
2022failed:
2023 MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
2024 dasd_exit();
2025 return rc;
2026}
2027
2028module_init(dasd_init);
2029module_exit(dasd_exit);
2030
2031EXPORT_SYMBOL(dasd_debug_area);
2032EXPORT_SYMBOL(dasd_diag_discipline_pointer);
2033
2034EXPORT_SYMBOL(dasd_add_request_head);
2035EXPORT_SYMBOL(dasd_add_request_tail);
2036EXPORT_SYMBOL(dasd_cancel_req);
2037EXPORT_SYMBOL(dasd_clear_timer);
2038EXPORT_SYMBOL(dasd_enable_device);
2039EXPORT_SYMBOL(dasd_int_handler);
2040EXPORT_SYMBOL(dasd_kfree_request);
2041EXPORT_SYMBOL(dasd_kick_device);
2042EXPORT_SYMBOL(dasd_kmalloc_request);
2043EXPORT_SYMBOL(dasd_schedule_bh);
2044EXPORT_SYMBOL(dasd_set_target_state);
2045EXPORT_SYMBOL(dasd_set_timer);
2046EXPORT_SYMBOL(dasd_sfree_request);
2047EXPORT_SYMBOL(dasd_sleep_on);
2048EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2049EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2050EXPORT_SYMBOL(dasd_smalloc_request);
2051EXPORT_SYMBOL(dasd_start_IO);
2052EXPORT_SYMBOL(dasd_term_IO);
2053
2054EXPORT_SYMBOL_GPL(dasd_generic_probe);
2055EXPORT_SYMBOL_GPL(dasd_generic_remove);
2056EXPORT_SYMBOL_GPL(dasd_generic_notify);
2057EXPORT_SYMBOL_GPL(dasd_generic_set_online);
2058EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
2059EXPORT_SYMBOL_GPL(dasd_generic_auto_online);
2060
2061/*
2062 * Overrides for Emacs so that we follow Linus's tabbing style.
2063 * Emacs will notice this stuff at the end of the file and automatically
2064 * adjust the settings for this buffer only. This must remain at the end
2065 * of the file.
2066 * ---------------------------------------------------------------------------
2067 * Local variables:
2068 * c-indent-level: 4
2069 * c-brace-imaginary-offset: 0
2070 * c-brace-offset: -4
2071 * c-argdecl-indent: 4
2072 * c-label-offset: -4
2073 * c-continued-statement-offset: 4
2074 * c-continued-brace-offset: 0
2075 * indent-tabs-mode: 1
2076 * tab-width: 8
2077 * End:
2078 */