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-rw-r--r--drivers/s390/block/dasd.c2065
1 files changed, 2065 insertions, 0 deletions
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
new file mode 100644
index 000000000000..b755bac6ccbc
--- /dev/null
+++ b/drivers/s390/block/dasd.c
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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: 1.158 $
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 */
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 */
179 device->debug_area = debug_register(device->cdev->dev.bus_id, 0, 2,
180 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;
1134 int nr_queued;
1135
1136 queue = device->request_queue;
1137 /* No queue ? Then there is nothing to do. */
1138 if (queue == NULL)
1139 return;
1140
1141 /*
1142 * We requeue request from the block device queue to the ccw
1143 * queue only in two states. In state DASD_STATE_READY the
1144 * partition detection is done and we need to requeue requests
1145 * for that. State DASD_STATE_ONLINE is normal block device
1146 * operation.
1147 */
1148 if (device->state != DASD_STATE_READY &&
1149 device->state != DASD_STATE_ONLINE)
1150 return;
1151 nr_queued = 0;
1152 /* Now we try to fetch requests from the request queue */
1153 list_for_each_entry(cqr, &device->ccw_queue, list)
1154 if (cqr->status == DASD_CQR_QUEUED)
1155 nr_queued++;
1156 while (!blk_queue_plugged(queue) &&
1157 elv_next_request(queue) &&
1158 nr_queued < DASD_CHANQ_MAX_SIZE) {
1159 req = elv_next_request(queue);
1160 if (test_bit(DASD_FLAG_RO, &device->flags) &&
1161 rq_data_dir(req) == WRITE) {
1162 DBF_DEV_EVENT(DBF_ERR, device,
1163 "Rejecting write request %p",
1164 req);
1165 blkdev_dequeue_request(req);
1166 dasd_end_request(req, 0);
1167 continue;
1168 }
1169 if (device->stopped & DASD_STOPPED_DC_EIO) {
1170 blkdev_dequeue_request(req);
1171 dasd_end_request(req, 0);
1172 continue;
1173 }
1174 cqr = device->discipline->build_cp(device, req);
1175 if (IS_ERR(cqr)) {
1176 if (PTR_ERR(cqr) == -ENOMEM)
1177 break; /* terminate request queue loop */
1178 DBF_DEV_EVENT(DBF_ERR, device,
1179 "CCW creation failed (rc=%ld) "
1180 "on request %p",
1181 PTR_ERR(cqr), req);
1182 blkdev_dequeue_request(req);
1183 dasd_end_request(req, 0);
1184 continue;
1185 }
1186 cqr->callback = dasd_end_request_cb;
1187 cqr->callback_data = (void *) req;
1188 cqr->status = DASD_CQR_QUEUED;
1189 blkdev_dequeue_request(req);
1190 list_add_tail(&cqr->list, &device->ccw_queue);
1191 dasd_profile_start(device, cqr, req);
1192 nr_queued++;
1193 }
1194}
1195
1196/*
1197 * Take a look at the first request on the ccw queue and check
1198 * if it reached its expire time. If so, terminate the IO.
1199 */
1200static inline void
1201__dasd_check_expire(struct dasd_device * device)
1202{
1203 struct dasd_ccw_req *cqr;
1204
1205 if (list_empty(&device->ccw_queue))
1206 return;
1207 cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1208 if (cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) {
1209 if (time_after_eq(jiffies, cqr->expires + cqr->starttime)) {
1210 if (device->discipline->term_IO(cqr) != 0)
1211 /* Hmpf, try again in 1/10 sec */
1212 dasd_set_timer(device, 10);
1213 }
1214 }
1215}
1216
1217/*
1218 * Take a look at the first request on the ccw queue and check
1219 * if it needs to be started.
1220 */
1221static inline void
1222__dasd_start_head(struct dasd_device * device)
1223{
1224 struct dasd_ccw_req *cqr;
1225 int rc;
1226
1227 if (list_empty(&device->ccw_queue))
1228 return;
1229 cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1230 if ((cqr->status == DASD_CQR_QUEUED) &&
1231 (!device->stopped)) {
1232 /* try to start the first I/O that can be started */
1233 rc = device->discipline->start_IO(cqr);
1234 if (rc == 0)
1235 dasd_set_timer(device, cqr->expires);
1236 else if (rc == -EACCES) {
1237 dasd_schedule_bh(device);
1238 } else
1239 /* Hmpf, try again in 1/2 sec */
1240 dasd_set_timer(device, 50);
1241 }
1242}
1243
1244/*
1245 * Remove requests from the ccw queue.
1246 */
1247static void
1248dasd_flush_ccw_queue(struct dasd_device * device, int all)
1249{
1250 struct list_head flush_queue;
1251 struct list_head *l, *n;
1252 struct dasd_ccw_req *cqr;
1253
1254 INIT_LIST_HEAD(&flush_queue);
1255 spin_lock_irq(get_ccwdev_lock(device->cdev));
1256 list_for_each_safe(l, n, &device->ccw_queue) {
1257 cqr = list_entry(l, struct dasd_ccw_req, list);
1258 /* Flush all request or only block device requests? */
1259 if (all == 0 && cqr->callback == dasd_end_request_cb)
1260 continue;
1261 if (cqr->status == DASD_CQR_IN_IO)
1262 device->discipline->term_IO(cqr);
1263 if (cqr->status != DASD_CQR_DONE ||
1264 cqr->status != DASD_CQR_FAILED) {
1265 cqr->status = DASD_CQR_FAILED;
1266 cqr->stopclk = get_clock();
1267 }
1268 /* Process finished ERP request. */
1269 if (cqr->refers) {
1270 __dasd_process_erp(device, cqr);
1271 continue;
1272 }
1273 /* Rechain request on device request queue */
1274 cqr->endclk = get_clock();
1275 list_move_tail(&cqr->list, &flush_queue);
1276 }
1277 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1278 /* Now call the callback function of flushed requests */
1279 list_for_each_safe(l, n, &flush_queue) {
1280 cqr = list_entry(l, struct dasd_ccw_req, list);
1281 if (cqr->callback != NULL)
1282 (cqr->callback)(cqr, cqr->callback_data);
1283 }
1284}
1285
1286/*
1287 * Acquire the device lock and process queues for the device.
1288 */
1289static void
1290dasd_tasklet(struct dasd_device * device)
1291{
1292 struct list_head final_queue;
1293 struct list_head *l, *n;
1294 struct dasd_ccw_req *cqr;
1295
1296 atomic_set (&device->tasklet_scheduled, 0);
1297 INIT_LIST_HEAD(&final_queue);
1298 spin_lock_irq(get_ccwdev_lock(device->cdev));
1299 /* Check expire time of first request on the ccw queue. */
1300 __dasd_check_expire(device);
1301 /* Finish off requests on ccw queue */
1302 __dasd_process_ccw_queue(device, &final_queue);
1303 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1304 /* Now call the callback function of requests with final status */
1305 list_for_each_safe(l, n, &final_queue) {
1306 cqr = list_entry(l, struct dasd_ccw_req, list);
1307 list_del(&cqr->list);
1308 if (cqr->callback != NULL)
1309 (cqr->callback)(cqr, cqr->callback_data);
1310 }
1311 spin_lock_irq(&device->request_queue_lock);
1312 spin_lock(get_ccwdev_lock(device->cdev));
1313 /* Get new request from the block device request queue */
1314 __dasd_process_blk_queue(device);
1315 /* Now check if the head of the ccw queue needs to be started. */
1316 __dasd_start_head(device);
1317 spin_unlock(get_ccwdev_lock(device->cdev));
1318 spin_unlock_irq(&device->request_queue_lock);
1319 dasd_put_device(device);
1320}
1321
1322/*
1323 * Schedules a call to dasd_tasklet over the device tasklet.
1324 */
1325void
1326dasd_schedule_bh(struct dasd_device * device)
1327{
1328 /* Protect against rescheduling. */
1329 if (atomic_compare_and_swap (0, 1, &device->tasklet_scheduled))
1330 return;
1331 dasd_get_device(device);
1332 tasklet_hi_schedule(&device->tasklet);
1333}
1334
1335/*
1336 * Queue a request to the head of the ccw_queue. Start the I/O if
1337 * possible.
1338 */
1339void
1340dasd_add_request_head(struct dasd_ccw_req *req)
1341{
1342 struct dasd_device *device;
1343 unsigned long flags;
1344
1345 device = req->device;
1346 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1347 req->status = DASD_CQR_QUEUED;
1348 req->device = device;
1349 list_add(&req->list, &device->ccw_queue);
1350 /* let the bh start the request to keep them in order */
1351 dasd_schedule_bh(device);
1352 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1353}
1354
1355/*
1356 * Queue a request to the tail of the ccw_queue. Start the I/O if
1357 * possible.
1358 */
1359void
1360dasd_add_request_tail(struct dasd_ccw_req *req)
1361{
1362 struct dasd_device *device;
1363 unsigned long flags;
1364
1365 device = req->device;
1366 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1367 req->status = DASD_CQR_QUEUED;
1368 req->device = device;
1369 list_add_tail(&req->list, &device->ccw_queue);
1370 /* let the bh start the request to keep them in order */
1371 dasd_schedule_bh(device);
1372 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1373}
1374
1375/*
1376 * Wakeup callback.
1377 */
1378static void
1379dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
1380{
1381 wake_up((wait_queue_head_t *) data);
1382}
1383
1384static inline int
1385_wait_for_wakeup(struct dasd_ccw_req *cqr)
1386{
1387 struct dasd_device *device;
1388 int rc;
1389
1390 device = cqr->device;
1391 spin_lock_irq(get_ccwdev_lock(device->cdev));
1392 rc = cqr->status == DASD_CQR_DONE || cqr->status == DASD_CQR_FAILED;
1393 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1394 return rc;
1395}
1396
1397/*
1398 * Attempts to start a special ccw queue and waits for its completion.
1399 */
1400int
1401dasd_sleep_on(struct dasd_ccw_req * cqr)
1402{
1403 wait_queue_head_t wait_q;
1404 struct dasd_device *device;
1405 int rc;
1406
1407 device = cqr->device;
1408 spin_lock_irq(get_ccwdev_lock(device->cdev));
1409
1410 init_waitqueue_head (&wait_q);
1411 cqr->callback = dasd_wakeup_cb;
1412 cqr->callback_data = (void *) &wait_q;
1413 cqr->status = DASD_CQR_QUEUED;
1414 list_add_tail(&cqr->list, &device->ccw_queue);
1415
1416 /* let the bh start the request to keep them in order */
1417 dasd_schedule_bh(device);
1418
1419 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1420
1421 wait_event(wait_q, _wait_for_wakeup(cqr));
1422
1423 /* Request status is either done or failed. */
1424 rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1425 return rc;
1426}
1427
1428/*
1429 * Attempts to start a special ccw queue and wait interruptible
1430 * for its completion.
1431 */
1432int
1433dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
1434{
1435 wait_queue_head_t wait_q;
1436 struct dasd_device *device;
1437 int rc, finished;
1438
1439 device = cqr->device;
1440 spin_lock_irq(get_ccwdev_lock(device->cdev));
1441
1442 init_waitqueue_head (&wait_q);
1443 cqr->callback = dasd_wakeup_cb;
1444 cqr->callback_data = (void *) &wait_q;
1445 cqr->status = DASD_CQR_QUEUED;
1446 list_add_tail(&cqr->list, &device->ccw_queue);
1447
1448 /* let the bh start the request to keep them in order */
1449 dasd_schedule_bh(device);
1450 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1451
1452 finished = 0;
1453 while (!finished) {
1454 rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
1455 if (rc != -ERESTARTSYS) {
1456 /* Request status is either done or failed. */
1457 rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1458 break;
1459 }
1460 spin_lock_irq(get_ccwdev_lock(device->cdev));
1461 if (cqr->status == DASD_CQR_IN_IO &&
1462 device->discipline->term_IO(cqr) == 0) {
1463 list_del(&cqr->list);
1464 finished = 1;
1465 }
1466 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1467 }
1468 return rc;
1469}
1470
1471/*
1472 * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
1473 * for eckd devices) the currently running request has to be terminated
1474 * and be put back to status queued, before the special request is added
1475 * to the head of the queue. Then the special request is waited on normally.
1476 */
1477static inline int
1478_dasd_term_running_cqr(struct dasd_device *device)
1479{
1480 struct dasd_ccw_req *cqr;
1481 int rc;
1482
1483 if (list_empty(&device->ccw_queue))
1484 return 0;
1485 cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
1486 rc = device->discipline->term_IO(cqr);
1487 if (rc == 0) {
1488 /* termination successful */
1489 cqr->status = DASD_CQR_QUEUED;
1490 cqr->startclk = cqr->stopclk = 0;
1491 cqr->starttime = 0;
1492 }
1493 return rc;
1494}
1495
1496int
1497dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
1498{
1499 wait_queue_head_t wait_q;
1500 struct dasd_device *device;
1501 int rc;
1502
1503 device = cqr->device;
1504 spin_lock_irq(get_ccwdev_lock(device->cdev));
1505 rc = _dasd_term_running_cqr(device);
1506 if (rc) {
1507 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1508 return rc;
1509 }
1510
1511 init_waitqueue_head (&wait_q);
1512 cqr->callback = dasd_wakeup_cb;
1513 cqr->callback_data = (void *) &wait_q;
1514 cqr->status = DASD_CQR_QUEUED;
1515 list_add(&cqr->list, &device->ccw_queue);
1516
1517 /* let the bh start the request to keep them in order */
1518 dasd_schedule_bh(device);
1519
1520 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1521
1522 wait_event(wait_q, _wait_for_wakeup(cqr));
1523
1524 /* Request status is either done or failed. */
1525 rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
1526 return rc;
1527}
1528
1529/*
1530 * Cancels a request that was started with dasd_sleep_on_req.
1531 * This is useful to timeout requests. The request will be
1532 * terminated if it is currently in i/o.
1533 * Returns 1 if the request has been terminated.
1534 */
1535int
1536dasd_cancel_req(struct dasd_ccw_req *cqr)
1537{
1538 struct dasd_device *device = cqr->device;
1539 unsigned long flags;
1540 int rc;
1541
1542 rc = 0;
1543 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1544 switch (cqr->status) {
1545 case DASD_CQR_QUEUED:
1546 /* request was not started - just set to failed */
1547 cqr->status = DASD_CQR_FAILED;
1548 break;
1549 case DASD_CQR_IN_IO:
1550 /* request in IO - terminate IO and release again */
1551 if (device->discipline->term_IO(cqr) != 0)
1552 /* what to do if unable to terminate ??????
1553 e.g. not _IN_IO */
1554 cqr->status = DASD_CQR_FAILED;
1555 cqr->stopclk = get_clock();
1556 rc = 1;
1557 break;
1558 case DASD_CQR_DONE:
1559 case DASD_CQR_FAILED:
1560 /* already finished - do nothing */
1561 break;
1562 default:
1563 DEV_MESSAGE(KERN_ALERT, device,
1564 "invalid status %02x in request",
1565 cqr->status);
1566 BUG();
1567
1568 }
1569 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1570 dasd_schedule_bh(device);
1571 return rc;
1572}
1573
1574/*
1575 * SECTION: Block device operations (request queue, partitions, open, release).
1576 */
1577
1578/*
1579 * Dasd request queue function. Called from ll_rw_blk.c
1580 */
1581static void
1582do_dasd_request(request_queue_t * queue)
1583{
1584 struct dasd_device *device;
1585
1586 device = (struct dasd_device *) queue->queuedata;
1587 spin_lock(get_ccwdev_lock(device->cdev));
1588 /* Get new request from the block device request queue */
1589 __dasd_process_blk_queue(device);
1590 /* Now check if the head of the ccw queue needs to be started. */
1591 __dasd_start_head(device);
1592 spin_unlock(get_ccwdev_lock(device->cdev));
1593}
1594
1595/*
1596 * Allocate and initialize request queue and default I/O scheduler.
1597 */
1598static int
1599dasd_alloc_queue(struct dasd_device * device)
1600{
1601 int rc;
1602
1603 device->request_queue = blk_init_queue(do_dasd_request,
1604 &device->request_queue_lock);
1605 if (device->request_queue == NULL)
1606 return -ENOMEM;
1607
1608 device->request_queue->queuedata = device;
1609
1610 elevator_exit(device->request_queue->elevator);
1611 rc = elevator_init(device->request_queue, "deadline");
1612 if (rc) {
1613 blk_cleanup_queue(device->request_queue);
1614 return rc;
1615 }
1616 return 0;
1617}
1618
1619/*
1620 * Allocate and initialize request queue.
1621 */
1622static void
1623dasd_setup_queue(struct dasd_device * device)
1624{
1625 int max;
1626
1627 blk_queue_hardsect_size(device->request_queue, device->bp_block);
1628 max = device->discipline->max_blocks << device->s2b_shift;
1629 blk_queue_max_sectors(device->request_queue, max);
1630 blk_queue_max_phys_segments(device->request_queue, -1L);
1631 blk_queue_max_hw_segments(device->request_queue, -1L);
1632 blk_queue_max_segment_size(device->request_queue, -1L);
1633 blk_queue_segment_boundary(device->request_queue, -1L);
1634}
1635
1636/*
1637 * Deactivate and free request queue.
1638 */
1639static void
1640dasd_free_queue(struct dasd_device * device)
1641{
1642 if (device->request_queue) {
1643 blk_cleanup_queue(device->request_queue);
1644 device->request_queue = NULL;
1645 }
1646}
1647
1648/*
1649 * Flush request on the request queue.
1650 */
1651static void
1652dasd_flush_request_queue(struct dasd_device * device)
1653{
1654 struct request *req;
1655
1656 if (!device->request_queue)
1657 return;
1658
1659 spin_lock_irq(&device->request_queue_lock);
1660 while (!list_empty(&device->request_queue->queue_head)) {
1661 req = elv_next_request(device->request_queue);
1662 if (req == NULL)
1663 break;
1664 dasd_end_request(req, 0);
1665 blkdev_dequeue_request(req);
1666 }
1667 spin_unlock_irq(&device->request_queue_lock);
1668}
1669
1670static int
1671dasd_open(struct inode *inp, struct file *filp)
1672{
1673 struct gendisk *disk = inp->i_bdev->bd_disk;
1674 struct dasd_device *device = disk->private_data;
1675 int rc;
1676
1677 atomic_inc(&device->open_count);
1678 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1679 rc = -ENODEV;
1680 goto unlock;
1681 }
1682
1683 if (!try_module_get(device->discipline->owner)) {
1684 rc = -EINVAL;
1685 goto unlock;
1686 }
1687
1688 if (dasd_probeonly) {
1689 DEV_MESSAGE(KERN_INFO, device, "%s",
1690 "No access to device due to probeonly mode");
1691 rc = -EPERM;
1692 goto out;
1693 }
1694
1695 if (device->state < DASD_STATE_BASIC) {
1696 DBF_DEV_EVENT(DBF_ERR, device, " %s",
1697 " Cannot open unrecognized device");
1698 rc = -ENODEV;
1699 goto out;
1700 }
1701
1702 return 0;
1703
1704out:
1705 module_put(device->discipline->owner);
1706unlock:
1707 atomic_dec(&device->open_count);
1708 return rc;
1709}
1710
1711static int
1712dasd_release(struct inode *inp, struct file *filp)
1713{
1714 struct gendisk *disk = inp->i_bdev->bd_disk;
1715 struct dasd_device *device = disk->private_data;
1716
1717 atomic_dec(&device->open_count);
1718 module_put(device->discipline->owner);
1719 return 0;
1720}
1721
1722struct block_device_operations
1723dasd_device_operations = {
1724 .owner = THIS_MODULE,
1725 .open = dasd_open,
1726 .release = dasd_release,
1727 .ioctl = dasd_ioctl,
1728};
1729
1730
1731static void
1732dasd_exit(void)
1733{
1734#ifdef CONFIG_PROC_FS
1735 dasd_proc_exit();
1736#endif
1737 dasd_ioctl_exit();
1738 dasd_gendisk_exit();
1739 dasd_devmap_exit();
1740 devfs_remove("dasd");
1741 if (dasd_debug_area != NULL) {
1742 debug_unregister(dasd_debug_area);
1743 dasd_debug_area = NULL;
1744 }
1745}
1746
1747/*
1748 * SECTION: common functions for ccw_driver use
1749 */
1750
1751/* initial attempt at a probe function. this can be simplified once
1752 * the other detection code is gone */
1753int
1754dasd_generic_probe (struct ccw_device *cdev,
1755 struct dasd_discipline *discipline)
1756{
1757 int ret;
1758
1759 ret = dasd_add_sysfs_files(cdev);
1760 if (ret) {
1761 printk(KERN_WARNING
1762 "dasd_generic_probe: could not add sysfs entries "
1763 "for %s\n", cdev->dev.bus_id);
1764 }
1765
1766 cdev->handler = &dasd_int_handler;
1767
1768 return ret;
1769}
1770
1771/* this will one day be called from a global not_oper handler.
1772 * It is also used by driver_unregister during module unload */
1773void
1774dasd_generic_remove (struct ccw_device *cdev)
1775{
1776 struct dasd_device *device;
1777
1778 dasd_remove_sysfs_files(cdev);
1779 device = dasd_device_from_cdev(cdev);
1780 if (IS_ERR(device))
1781 return;
1782 if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1783 /* Already doing offline processing */
1784 dasd_put_device(device);
1785 return;
1786 }
1787 /*
1788 * This device is removed unconditionally. Set offline
1789 * flag to prevent dasd_open from opening it while it is
1790 * no quite down yet.
1791 */
1792 dasd_set_target_state(device, DASD_STATE_NEW);
1793 /* dasd_delete_device destroys the device reference. */
1794 dasd_delete_device(device);
1795}
1796
1797/* activate a device. This is called from dasd_{eckd,fba}_probe() when either
1798 * the device is detected for the first time and is supposed to be used
1799 * or the user has started activation through sysfs */
1800int
1801dasd_generic_set_online (struct ccw_device *cdev,
1802 struct dasd_discipline *discipline)
1803
1804{
1805 struct dasd_device *device;
1806 int rc;
1807
1808 device = dasd_create_device(cdev);
1809 if (IS_ERR(device))
1810 return PTR_ERR(device);
1811
1812 if (test_bit(DASD_FLAG_USE_DIAG, &device->flags)) {
1813 if (!dasd_diag_discipline_pointer) {
1814 printk (KERN_WARNING
1815 "dasd_generic couldn't online device %s "
1816 "- discipline DIAG not available\n",
1817 cdev->dev.bus_id);
1818 dasd_delete_device(device);
1819 return -ENODEV;
1820 }
1821 discipline = dasd_diag_discipline_pointer;
1822 }
1823 device->discipline = discipline;
1824
1825 rc = discipline->check_device(device);
1826 if (rc) {
1827 printk (KERN_WARNING
1828 "dasd_generic couldn't online device %s "
1829 "with discipline %s rc=%i\n",
1830 cdev->dev.bus_id, discipline->name, rc);
1831 dasd_delete_device(device);
1832 return rc;
1833 }
1834
1835 dasd_set_target_state(device, DASD_STATE_ONLINE);
1836 if (device->state <= DASD_STATE_KNOWN) {
1837 printk (KERN_WARNING
1838 "dasd_generic discipline not found for %s\n",
1839 cdev->dev.bus_id);
1840 rc = -ENODEV;
1841 dasd_set_target_state(device, DASD_STATE_NEW);
1842 dasd_delete_device(device);
1843 } else
1844 pr_debug("dasd_generic device %s found\n",
1845 cdev->dev.bus_id);
1846
1847 /* FIXME: we have to wait for the root device but we don't want
1848 * to wait for each single device but for all at once. */
1849 wait_event(dasd_init_waitq, _wait_for_device(device));
1850
1851 dasd_put_device(device);
1852
1853 return rc;
1854}
1855
1856int
1857dasd_generic_set_offline (struct ccw_device *cdev)
1858{
1859 struct dasd_device *device;
1860 int max_count;
1861
1862 device = dasd_device_from_cdev(cdev);
1863 if (IS_ERR(device))
1864 return PTR_ERR(device);
1865 if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
1866 /* Already doing offline processing */
1867 dasd_put_device(device);
1868 return 0;
1869 }
1870 /*
1871 * We must make sure that this device is currently not in use.
1872 * The open_count is increased for every opener, that includes
1873 * the blkdev_get in dasd_scan_partitions. We are only interested
1874 * in the other openers.
1875 */
1876 max_count = device->bdev ? 0 : -1;
1877 if (atomic_read(&device->open_count) > max_count) {
1878 printk (KERN_WARNING "Can't offline dasd device with open"
1879 " count = %i.\n",
1880 atomic_read(&device->open_count));
1881 clear_bit(DASD_FLAG_OFFLINE, &device->flags);
1882 dasd_put_device(device);
1883 return -EBUSY;
1884 }
1885 dasd_set_target_state(device, DASD_STATE_NEW);
1886 /* dasd_delete_device destroys the device reference. */
1887 dasd_delete_device(device);
1888
1889 return 0;
1890}
1891
1892int
1893dasd_generic_notify(struct ccw_device *cdev, int event)
1894{
1895 struct dasd_device *device;
1896 struct dasd_ccw_req *cqr;
1897 unsigned long flags;
1898 int ret;
1899
1900 device = dasd_device_from_cdev(cdev);
1901 if (IS_ERR(device))
1902 return 0;
1903 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1904 ret = 0;
1905 switch (event) {
1906 case CIO_GONE:
1907 case CIO_NO_PATH:
1908 if (device->state < DASD_STATE_BASIC)
1909 break;
1910 /* Device is active. We want to keep it. */
1911 if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
1912 list_for_each_entry(cqr, &device->ccw_queue, list)
1913 if (cqr->status == DASD_CQR_IN_IO)
1914 cqr->status = DASD_CQR_FAILED;
1915 device->stopped |= DASD_STOPPED_DC_EIO;
1916 dasd_schedule_bh(device);
1917 } else {
1918 list_for_each_entry(cqr, &device->ccw_queue, list)
1919 if (cqr->status == DASD_CQR_IN_IO) {
1920 cqr->status = DASD_CQR_QUEUED;
1921 cqr->retries++;
1922 }
1923 device->stopped |= DASD_STOPPED_DC_WAIT;
1924 dasd_set_timer(device, 0);
1925 }
1926 ret = 1;
1927 break;
1928 case CIO_OPER:
1929 /* FIXME: add a sanity check. */
1930 device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
1931 dasd_schedule_bh(device);
1932 ret = 1;
1933 break;
1934 }
1935 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1936 dasd_put_device(device);
1937 return ret;
1938}
1939
1940/*
1941 * Automatically online either all dasd devices (dasd_autodetect) or
1942 * all devices specified with dasd= parameters.
1943 */
1944void
1945dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver)
1946{
1947 struct device_driver *drv;
1948 struct device *d, *dev;
1949 struct ccw_device *cdev;
1950
1951 drv = get_driver(&dasd_discipline_driver->driver);
1952 down_read(&drv->bus->subsys.rwsem);
1953 dev = NULL;
1954 list_for_each_entry(d, &drv->devices, driver_list) {
1955 dev = get_device(d);
1956 if (!dev)
1957 continue;
1958 cdev = to_ccwdev(dev);
1959 if (dasd_autodetect || dasd_busid_known(cdev->dev.bus_id) == 0)
1960 ccw_device_set_online(cdev);
1961 put_device(dev);
1962 }
1963 up_read(&drv->bus->subsys.rwsem);
1964 put_driver(drv);
1965}
1966
1967static int __init
1968dasd_init(void)
1969{
1970 int rc;
1971
1972 init_waitqueue_head(&dasd_init_waitq);
1973
1974 /* register 'common' DASD debug area, used for all DBF_XXX calls */
1975 dasd_debug_area = debug_register("dasd", 0, 2, 8 * sizeof (long));
1976 if (dasd_debug_area == NULL) {
1977 rc = -ENOMEM;
1978 goto failed;
1979 }
1980 debug_register_view(dasd_debug_area, &debug_sprintf_view);
1981 debug_set_level(dasd_debug_area, DBF_EMERG);
1982
1983 DBF_EVENT(DBF_EMERG, "%s", "debug area created");
1984
1985 dasd_diag_discipline_pointer = NULL;
1986
1987 rc = devfs_mk_dir("dasd");
1988 if (rc)
1989 goto failed;
1990 rc = dasd_devmap_init();
1991 if (rc)
1992 goto failed;
1993 rc = dasd_gendisk_init();
1994 if (rc)
1995 goto failed;
1996 rc = dasd_parse();
1997 if (rc)
1998 goto failed;
1999 rc = dasd_ioctl_init();
2000 if (rc)
2001 goto failed;
2002#ifdef CONFIG_PROC_FS
2003 rc = dasd_proc_init();
2004 if (rc)
2005 goto failed;
2006#endif
2007
2008 return 0;
2009failed:
2010 MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
2011 dasd_exit();
2012 return rc;
2013}
2014
2015module_init(dasd_init);
2016module_exit(dasd_exit);
2017
2018EXPORT_SYMBOL(dasd_debug_area);
2019EXPORT_SYMBOL(dasd_diag_discipline_pointer);
2020
2021EXPORT_SYMBOL(dasd_add_request_head);
2022EXPORT_SYMBOL(dasd_add_request_tail);
2023EXPORT_SYMBOL(dasd_cancel_req);
2024EXPORT_SYMBOL(dasd_clear_timer);
2025EXPORT_SYMBOL(dasd_enable_device);
2026EXPORT_SYMBOL(dasd_int_handler);
2027EXPORT_SYMBOL(dasd_kfree_request);
2028EXPORT_SYMBOL(dasd_kick_device);
2029EXPORT_SYMBOL(dasd_kmalloc_request);
2030EXPORT_SYMBOL(dasd_schedule_bh);
2031EXPORT_SYMBOL(dasd_set_target_state);
2032EXPORT_SYMBOL(dasd_set_timer);
2033EXPORT_SYMBOL(dasd_sfree_request);
2034EXPORT_SYMBOL(dasd_sleep_on);
2035EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2036EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2037EXPORT_SYMBOL(dasd_smalloc_request);
2038EXPORT_SYMBOL(dasd_start_IO);
2039EXPORT_SYMBOL(dasd_term_IO);
2040
2041EXPORT_SYMBOL_GPL(dasd_generic_probe);
2042EXPORT_SYMBOL_GPL(dasd_generic_remove);
2043EXPORT_SYMBOL_GPL(dasd_generic_notify);
2044EXPORT_SYMBOL_GPL(dasd_generic_set_online);
2045EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
2046EXPORT_SYMBOL_GPL(dasd_generic_auto_online);
2047
2048/*
2049 * Overrides for Emacs so that we follow Linus's tabbing style.
2050 * Emacs will notice this stuff at the end of the file and automatically
2051 * adjust the settings for this buffer only. This must remain at the end
2052 * of the file.
2053 * ---------------------------------------------------------------------------
2054 * Local variables:
2055 * c-indent-level: 4
2056 * c-brace-imaginary-offset: 0
2057 * c-brace-offset: -4
2058 * c-argdecl-indent: 4
2059 * c-label-offset: -4
2060 * c-continued-statement-offset: 4
2061 * c-continued-brace-offset: 0
2062 * indent-tabs-mode: 1
2063 * tab-width: 8
2064 * End:
2065 */
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