summaryrefslogtreecommitdiff
path: root/drivers/s390/cio/cio.c
blob: 5130d7c67239b337c71eeca67762f7061ee06abb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
// SPDX-License-Identifier: GPL-2.0
/*
 *   S/390 common I/O routines -- low level i/o calls
 *
 *    Copyright IBM Corp. 1999, 2008
 *    Author(s): Ingo Adlung (adlung@de.ibm.com)
 *		 Cornelia Huck (cornelia.huck@de.ibm.com)
 *		 Arnd Bergmann (arndb@de.ibm.com)
 *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
 */

#define KMSG_COMPONENT "cio"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/ftrace.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/kernel_stat.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <asm/cio.h>
#include <asm/delay.h>
#include <asm/irq.h>
#include <asm/irq_regs.h>
#include <asm/setup.h>
#include <asm/ipl.h>
#include <asm/chpid.h>
#include <asm/airq.h>
#include <asm/isc.h>
#include <linux/sched/cputime.h>
#include <asm/fcx.h>
#include <asm/nmi.h>
#include <asm/crw.h>
#include "cio.h"
#include "css.h"
#include "chsc.h"
#include "ioasm.h"
#include "io_sch.h"
#include "blacklist.h"
#include "cio_debug.h"
#include "chp.h"
#include "trace.h"

debug_info_t *cio_debug_msg_id;
debug_info_t *cio_debug_trace_id;
debug_info_t *cio_debug_crw_id;

DEFINE_PER_CPU_ALIGNED(struct irb, cio_irb);
EXPORT_PER_CPU_SYMBOL(cio_irb);

/*
 * Function: cio_debug_init
 * Initializes three debug logs for common I/O:
 * - cio_msg logs generic cio messages
 * - cio_trace logs the calling of different functions
 * - cio_crw logs machine check related cio messages
 */
static int __init cio_debug_init(void)
{
	cio_debug_msg_id = debug_register("cio_msg", 16, 1, 11 * sizeof(long));
	if (!cio_debug_msg_id)
		goto out_unregister;
	debug_register_view(cio_debug_msg_id, &debug_sprintf_view);
	debug_set_level(cio_debug_msg_id, 2);
	cio_debug_trace_id = debug_register("cio_trace", 16, 1, 16);
	if (!cio_debug_trace_id)
		goto out_unregister;
	debug_register_view(cio_debug_trace_id, &debug_hex_ascii_view);
	debug_set_level(cio_debug_trace_id, 2);
	cio_debug_crw_id = debug_register("cio_crw", 8, 1, 8 * sizeof(long));
	if (!cio_debug_crw_id)
		goto out_unregister;
	debug_register_view(cio_debug_crw_id, &debug_sprintf_view);
	debug_set_level(cio_debug_crw_id, 4);
	return 0;

out_unregister:
	debug_unregister(cio_debug_msg_id);
	debug_unregister(cio_debug_trace_id);
	debug_unregister(cio_debug_crw_id);
	return -1;
}

arch_initcall (cio_debug_init);

int cio_set_options(struct subchannel *sch, int flags)
{
	struct io_subchannel_private *priv = to_io_private(sch);

	priv->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
	priv->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
	priv->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
	return 0;
}

static int
cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
{
	char dbf_text[15];

	if (lpm != 0)
		sch->lpm &= ~lpm;
	else
		sch->lpm = 0;

	CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
		      "subchannel 0.%x.%04x!\n", sch->schid.ssid,
		      sch->schid.sch_no);

	if (cio_update_schib(sch))
		return -ENODEV;

	sprintf(dbf_text, "no%s", dev_name(&sch->dev));
	CIO_TRACE_EVENT(0, dbf_text);
	CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));

	return (sch->lpm ? -EACCES : -ENODEV);
}

int
cio_start_key (struct subchannel *sch,	/* subchannel structure */
	       struct ccw1 * cpa,	/* logical channel prog addr */
	       __u8 lpm,		/* logical path mask */
	       __u8 key)                /* storage key */
{
	struct io_subchannel_private *priv = to_io_private(sch);
	union orb *orb = &priv->orb;
	int ccode;

	CIO_TRACE_EVENT(5, "stIO");
	CIO_TRACE_EVENT(5, dev_name(&sch->dev));

	memset(orb, 0, sizeof(union orb));
	/* sch is always under 2G. */
	orb->cmd.intparm = (u32)(addr_t)sch;
	orb->cmd.fmt = 1;

	orb->cmd.pfch = priv->options.prefetch == 0;
	orb->cmd.spnd = priv->options.suspend;
	orb->cmd.ssic = priv->options.suspend && priv->options.inter;
	orb->cmd.lpm = (lpm != 0) ? lpm : sch->lpm;
	/*
	 * for 64 bit we always support 64 bit IDAWs with 4k page size only
	 */
	orb->cmd.c64 = 1;
	orb->cmd.i2k = 0;
	orb->cmd.key = key >> 4;
	/* issue "Start Subchannel" */
	orb->cmd.cpa = (__u32) __pa(cpa);
	ccode = ssch(sch->schid, orb);

	/* process condition code */
	CIO_HEX_EVENT(5, &ccode, sizeof(ccode));

	switch (ccode) {
	case 0:
		/*
		 * initialize device status information
		 */
		sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
		return 0;
	case 1:		/* status pending */
	case 2:		/* busy */
		return -EBUSY;
	case 3:		/* device/path not operational */
		return cio_start_handle_notoper(sch, lpm);
	default:
		return ccode;
	}
}
EXPORT_SYMBOL_GPL(cio_start_key);

int
cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
{
	return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
}
EXPORT_SYMBOL_GPL(cio_start);

/*
 * resume suspended I/O operation
 */
int
cio_resume (struct subchannel *sch)
{
	int ccode;

	CIO_TRACE_EVENT(4, "resIO");
	CIO_TRACE_EVENT(4, dev_name(&sch->dev));

	ccode = rsch (sch->schid);

	CIO_HEX_EVENT(4, &ccode, sizeof(ccode));

	switch (ccode) {
	case 0:
		sch->schib.scsw.cmd.actl |= SCSW_ACTL_RESUME_PEND;
		return 0;
	case 1:
		return -EBUSY;
	case 2:
		return -EINVAL;
	default:
		/*
		 * useless to wait for request completion
		 *  as device is no longer operational !
		 */
		return -ENODEV;
	}
}
EXPORT_SYMBOL_GPL(cio_resume);

/*
 * halt I/O operation
 */
int
cio_halt(struct subchannel *sch)
{
	int ccode;

	if (!sch)
		return -ENODEV;

	CIO_TRACE_EVENT(2, "haltIO");
	CIO_TRACE_EVENT(2, dev_name(&sch->dev));

	/*
	 * Issue "Halt subchannel" and process condition code
	 */
	ccode = hsch (sch->schid);

	CIO_HEX_EVENT(2, &ccode, sizeof(ccode));

	switch (ccode) {
	case 0:
		sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND;
		return 0;
	case 1:		/* status pending */
	case 2:		/* busy */
		return -EBUSY;
	default:		/* device not operational */
		return -ENODEV;
	}
}
EXPORT_SYMBOL_GPL(cio_halt);

/*
 * Clear I/O operation
 */
int
cio_clear(struct subchannel *sch)
{
	int ccode;

	if (!sch)
		return -ENODEV;

	CIO_TRACE_EVENT(2, "clearIO");
	CIO_TRACE_EVENT(2, dev_name(&sch->dev));

	/*
	 * Issue "Clear subchannel" and process condition code
	 */
	ccode = csch (sch->schid);

	CIO_HEX_EVENT(2, &ccode, sizeof(ccode));

	switch (ccode) {
	case 0:
		sch->schib.scsw.cmd.actl |= SCSW_ACTL_CLEAR_PEND;
		return 0;
	default:		/* device not operational */
		return -ENODEV;
	}
}
EXPORT_SYMBOL_GPL(cio_clear);

/*
 * Function: cio_cancel
 * Issues a "Cancel Subchannel" on the specified subchannel
 * Note: We don't need any fancy intparms and flags here
 *	 since xsch is executed synchronously.
 * Only for common I/O internal use as for now.
 */
int
cio_cancel (struct subchannel *sch)
{
	int ccode;

	if (!sch)
		return -ENODEV;

	CIO_TRACE_EVENT(2, "cancelIO");
	CIO_TRACE_EVENT(2, dev_name(&sch->dev));

	ccode = xsch (sch->schid);

	CIO_HEX_EVENT(2, &ccode, sizeof(ccode));

	switch (ccode) {
	case 0:		/* success */
		/* Update information in scsw. */
		if (cio_update_schib(sch))
			return -ENODEV;
		return 0;
	case 1:		/* status pending */
		return -EBUSY;
	case 2:		/* not applicable */
		return -EINVAL;
	default:	/* not oper */
		return -ENODEV;
	}
}
EXPORT_SYMBOL_GPL(cio_cancel);

/**
 * cio_cancel_halt_clear - Cancel running I/O by performing cancel, halt
 * and clear ordinally if subchannel is valid.
 * @sch: subchannel on which to perform the cancel_halt_clear operation
 * @iretry: the number of the times remained to retry the next operation
 *
 * This should be called repeatedly since halt/clear are asynchronous
 * operations. We do one try with cio_cancel, three tries with cio_halt,
 * 255 tries with cio_clear. The caller should initialize @iretry with
 * the value 255 for its first call to this, and keep using the same
 * @iretry in the subsequent calls until it gets a non -EBUSY return.
 *
 * Returns 0 if device now idle, -ENODEV for device not operational,
 * -EBUSY if an interrupt is expected (either from halt/clear or from a
 * status pending), and -EIO if out of retries.
 */
int cio_cancel_halt_clear(struct subchannel *sch, int *iretry)
{
	int ret;

	if (cio_update_schib(sch))
		return -ENODEV;
	if (!sch->schib.pmcw.ena)
		/* Not operational -> done. */
		return 0;
	/* Stage 1: cancel io. */
	if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_HALT_PEND) &&
	    !(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
		if (!scsw_is_tm(&sch->schib.scsw)) {
			ret = cio_cancel(sch);
			if (ret != -EINVAL)
				return ret;
		}
		/*
		 * Cancel io unsuccessful or not applicable (transport mode).
		 * Continue with asynchronous instructions.
		 */
		*iretry = 3;	/* 3 halt retries. */
	}
	/* Stage 2: halt io. */
	if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
		if (*iretry) {
			*iretry -= 1;
			ret = cio_halt(sch);
			if (ret != -EBUSY)
				return (ret == 0) ? -EBUSY : ret;
		}
		/* Halt io unsuccessful. */
		*iretry = 255;	/* 255 clear retries. */
	}
	/* Stage 3: clear io. */
	if (*iretry) {
		*iretry -= 1;
		ret = cio_clear(sch);
		return (ret == 0) ? -EBUSY : ret;
	}
	/* Function was unsuccessful */
	return -EIO;
}
EXPORT_SYMBOL_GPL(cio_cancel_halt_clear);

static void cio_apply_config(struct subchannel *sch, struct schib *schib)
{
	schib->pmcw.intparm = sch->config.intparm;
	schib->pmcw.mbi = sch->config.mbi;
	schib->pmcw.isc = sch->config.isc;
	schib->pmcw.ena = sch->config.ena;
	schib->pmcw.mme = sch->config.mme;
	schib->pmcw.mp = sch->config.mp;
	schib->pmcw.csense = sch->config.csense;
	schib->pmcw.mbfc = sch->config.mbfc;
	if (sch->config.mbfc)
		schib->mba = sch->config.mba;
}

static int cio_check_config(struct subchannel *sch, struct schib *schib)
{
	return (schib->pmcw.intparm == sch->config.intparm) &&
		(schib->pmcw.mbi == sch->config.mbi) &&
		(schib->pmcw.isc == sch->config.isc) &&
		(schib->pmcw.ena == sch->config.ena) &&
		(schib->pmcw.mme == sch->config.mme) &&
		(schib->pmcw.mp == sch->config.mp) &&
		(schib->pmcw.csense == sch->config.csense) &&
		(schib->pmcw.mbfc == sch->config.mbfc) &&
		(!sch->config.mbfc || (schib->mba == sch->config.mba));
}

/*
 * cio_commit_config - apply configuration to the subchannel
 */
int cio_commit_config(struct subchannel *sch)
{
	int ccode, retry, ret = 0;
	struct schib schib;
	struct irb irb;

	if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
		return -ENODEV;

	for (retry = 0; retry < 5; retry++) {
		/* copy desired changes to local schib */
		cio_apply_config(sch, &schib);
		ccode = msch(sch->schid, &schib);
		if (ccode < 0) /* -EIO if msch gets a program check. */
			return ccode;
		switch (ccode) {
		case 0: /* successful */
			if (stsch(sch->schid, &schib) ||
			    !css_sch_is_valid(&schib))
				return -ENODEV;
			if (cio_check_config(sch, &schib)) {
				/* commit changes from local schib */
				memcpy(&sch->schib, &schib, sizeof(schib));
				return 0;
			}
			ret = -EAGAIN;
			break;
		case 1: /* status pending */
			ret = -EBUSY;
			if (tsch(sch->schid, &irb))
				return ret;
			break;
		case 2: /* busy */
			udelay(100); /* allow for recovery */
			ret = -EBUSY;
			break;
		case 3: /* not operational */
			return -ENODEV;
		}
	}
	return ret;
}
EXPORT_SYMBOL_GPL(cio_commit_config);

/**
 * cio_update_schib - Perform stsch and update schib if subchannel is valid.
 * @sch: subchannel on which to perform stsch
 * Return zero on success, -ENODEV otherwise.
 */
int cio_update_schib(struct subchannel *sch)
{
	struct schib schib;

	if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
		return -ENODEV;

	memcpy(&sch->schib, &schib, sizeof(schib));
	return 0;
}
EXPORT_SYMBOL_GPL(cio_update_schib);

/**
 * cio_enable_subchannel - enable a subchannel.
 * @sch: subchannel to be enabled
 * @intparm: interruption parameter to set
 */
int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
{
	int ret;

	CIO_TRACE_EVENT(2, "ensch");
	CIO_TRACE_EVENT(2, dev_name(&sch->dev));

	if (sch_is_pseudo_sch(sch))
		return -EINVAL;
	if (cio_update_schib(sch))
		return -ENODEV;

	sch->config.ena = 1;
	sch->config.isc = sch->isc;
	sch->config.intparm = intparm;

	ret = cio_commit_config(sch);
	if (ret == -EIO) {
		/*
		 * Got a program check in msch. Try without
		 * the concurrent sense bit the next time.
		 */
		sch->config.csense = 0;
		ret = cio_commit_config(sch);
	}
	CIO_HEX_EVENT(2, &ret, sizeof(ret));
	return ret;
}
EXPORT_SYMBOL_GPL(cio_enable_subchannel);

/**
 * cio_disable_subchannel - disable a subchannel.
 * @sch: subchannel to disable
 */
int cio_disable_subchannel(struct subchannel *sch)
{
	int ret;

	CIO_TRACE_EVENT(2, "dissch");
	CIO_TRACE_EVENT(2, dev_name(&sch->dev));

	if (sch_is_pseudo_sch(sch))
		return 0;
	if (cio_update_schib(sch))
		return -ENODEV;

	sch->config.ena = 0;
	ret = cio_commit_config(sch);

	CIO_HEX_EVENT(2, &ret, sizeof(ret));
	return ret;
}
EXPORT_SYMBOL_GPL(cio_disable_subchannel);

static int cio_check_devno_blacklisted(struct subchannel *sch)
{
	if (is_blacklisted(sch->schid.ssid, sch->schib.pmcw.dev)) {
		/*
		 * This device must not be known to Linux. So we simply
		 * say that there is no device and return ENODEV.
		 */
		CIO_MSG_EVENT(6, "Blacklisted device detected "
			      "at devno %04X, subchannel set %x\n",
			      sch->schib.pmcw.dev, sch->schid.ssid);
		return -ENODEV;
	}
	return 0;
}

/**
 * cio_validate_subchannel - basic validation of subchannel
 * @sch: subchannel structure to be filled out
 * @schid: subchannel id
 *
 * Find out subchannel type and initialize struct subchannel.
 * Return codes:
 *   0 on success
 *   -ENXIO for non-defined subchannels
 *   -ENODEV for invalid subchannels or blacklisted devices
 *   -EIO for subchannels in an invalid subchannel set
 */
int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
{
	char dbf_txt[15];
	int ccode;
	int err;

	sprintf(dbf_txt, "valsch%x", schid.sch_no);
	CIO_TRACE_EVENT(4, dbf_txt);

	/*
	 * The first subchannel that is not-operational (ccode==3)
	 * indicates that there aren't any more devices available.
	 * If stsch gets an exception, it means the current subchannel set
	 * is not valid.
	 */
	ccode = stsch(schid, &sch->schib);
	if (ccode) {
		err = (ccode == 3) ? -ENXIO : ccode;
		goto out;
	}
	sch->st = sch->schib.pmcw.st;
	sch->schid = schid;

	switch (sch->st) {
	case SUBCHANNEL_TYPE_IO:
	case SUBCHANNEL_TYPE_MSG:
		if (!css_sch_is_valid(&sch->schib))
			err = -ENODEV;
		else
			err = cio_check_devno_blacklisted(sch);
		break;
	default:
		err = 0;
	}
	if (err)
		goto out;

	CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
		      sch->schid.ssid, sch->schid.sch_no, sch->st);
out:
	return err;
}

/*
 * do_cio_interrupt() handles all normal I/O device IRQ's
 */
static irqreturn_t do_cio_interrupt(int irq, void *dummy)
{
	struct tpi_info *tpi_info;
	struct subchannel *sch;
	struct irb *irb;

	set_cpu_flag(CIF_NOHZ_DELAY);
	tpi_info = (struct tpi_info *) &get_irq_regs()->int_code;
	trace_s390_cio_interrupt(tpi_info);
	irb = this_cpu_ptr(&cio_irb);
	sch = (struct subchannel *)(unsigned long) tpi_info->intparm;
	if (!sch) {
		/* Clear pending interrupt condition. */
		inc_irq_stat(IRQIO_CIO);
		tsch(tpi_info->schid, irb);
		return IRQ_HANDLED;
	}
	spin_lock(sch->lock);
	/* Store interrupt response block to lowcore. */
	if (tsch(tpi_info->schid, irb) == 0) {
		/* Keep subchannel information word up to date. */
		memcpy (&sch->schib.scsw, &irb->scsw, sizeof (irb->scsw));
		/* Call interrupt handler if there is one. */
		if (sch->driver && sch->driver->irq)
			sch->driver->irq(sch);
		else
			inc_irq_stat(IRQIO_CIO);
	} else
		inc_irq_stat(IRQIO_CIO);
	spin_unlock(sch->lock);

	return IRQ_HANDLED;
}

static struct irqaction io_interrupt = {
	.name	 = "IO",
	.handler = do_cio_interrupt,
};

void __init init_cio_interrupts(void)
{
	irq_set_chip_and_handler(IO_INTERRUPT,
				 &dummy_irq_chip, handle_percpu_irq);
	setup_irq(IO_INTERRUPT, &io_interrupt);
}

#ifdef CONFIG_CCW_CONSOLE
static struct subchannel *console_sch;
static struct lock_class_key console_sch_key;

/*
 * Use cio_tsch to update the subchannel status and call the interrupt handler
 * if status had been pending. Called with the subchannel's lock held.
 */
void cio_tsch(struct subchannel *sch)
{
	struct irb *irb;
	int irq_context;

	irb = this_cpu_ptr(&cio_irb);
	/* Store interrupt response block to lowcore. */
	if (tsch(sch->schid, irb) != 0)
		/* Not status pending or not operational. */
		return;
	memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
	/* Call interrupt handler with updated status. */
	irq_context = in_interrupt();
	if (!irq_context) {
		local_bh_disable();
		irq_enter();
	}
	kstat_incr_irq_this_cpu(IO_INTERRUPT);
	if (sch->driver && sch->driver->irq)
		sch->driver->irq(sch);
	else
		inc_irq_stat(IRQIO_CIO);
	if (!irq_context) {
		irq_exit();
		_local_bh_enable();
	}
}

static int cio_test_for_console(struct subchannel_id schid, void *data)
{
	struct schib schib;

	if (stsch(schid, &schib) != 0)
		return -ENXIO;
	if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
	    (schib.pmcw.dev == console_devno)) {
		console_irq = schid.sch_no;
		return 1; /* found */
	}
	return 0;
}

static int cio_get_console_sch_no(void)
{
	struct subchannel_id schid;
	struct schib schib;

	init_subchannel_id(&schid);
	if (console_irq != -1) {
		/* VM provided us with the irq number of the console. */
		schid.sch_no = console_irq;
		if (stsch(schid, &schib) != 0 ||
		    (schib.pmcw.st != SUBCHANNEL_TYPE_IO) || !schib.pmcw.dnv)
			return -1;
		console_devno = schib.pmcw.dev;
	} else if (console_devno != -1) {
		/* At least the console device number is known. */
		for_each_subchannel(cio_test_for_console, NULL);
	}
	return console_irq;
}

struct subchannel *cio_probe_console(void)
{
	struct subchannel_id schid;
	struct subchannel *sch;
	int sch_no, ret;

	sch_no = cio_get_console_sch_no();
	if (sch_no == -1) {
		pr_warn("No CCW console was found\n");
		return ERR_PTR(-ENODEV);
	}
	init_subchannel_id(&schid);
	schid.sch_no = sch_no;
	sch = css_alloc_subchannel(schid);
	if (IS_ERR(sch))
		return sch;

	lockdep_set_class(sch->lock, &console_sch_key);
	isc_register(CONSOLE_ISC);
	sch->config.isc = CONSOLE_ISC;
	sch->config.intparm = (u32)(addr_t)sch;
	ret = cio_commit_config(sch);
	if (ret) {
		isc_unregister(CONSOLE_ISC);
		put_device(&sch->dev);
		return ERR_PTR(ret);
	}
	console_sch = sch;
	return sch;
}

int cio_is_console(struct subchannel_id schid)
{
	if (!console_sch)
		return 0;
	return schid_equal(&schid, &console_sch->schid);
}

void cio_register_early_subchannels(void)
{
	int ret;

	if (!console_sch)
		return;

	ret = css_register_subchannel(console_sch);
	if (ret)
		put_device(&console_sch->dev);
}
#endif /* CONFIG_CCW_CONSOLE */

/**
 * cio_tm_start_key - perform start function
 * @sch: subchannel on which to perform the start function
 * @tcw: transport-command word to be started
 * @lpm: mask of paths to use
 * @key: storage key to use for storage access
 *
 * Start the tcw on the given subchannel. Return zero on success, non-zero
 * otherwise.
 */
int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
{
	int cc;
	union orb *orb = &to_io_private(sch)->orb;

	memset(orb, 0, sizeof(union orb));
	orb->tm.intparm = (u32) (addr_t) sch;
	orb->tm.key = key >> 4;
	orb->tm.b = 1;
	orb->tm.lpm = lpm ? lpm : sch->lpm;
	orb->tm.tcw = (u32) (addr_t) tcw;
	cc = ssch(sch->schid, orb);
	switch (cc) {
	case 0:
		return 0;
	case 1:
	case 2:
		return -EBUSY;
	default:
		return cio_start_handle_notoper(sch, lpm);
	}
}
EXPORT_SYMBOL_GPL(cio_tm_start_key);

/**
 * cio_tm_intrg - perform interrogate function
 * @sch: subchannel on which to perform the interrogate function
 *
 * If the specified subchannel is running in transport-mode, perform the
 * interrogate function. Return zero on success, non-zero otherwie.
 */
int cio_tm_intrg(struct subchannel *sch)
{
	int cc;

	if (!to_io_private(sch)->orb.tm.b)
		return -EINVAL;
	cc = xsch(sch->schid);
	switch (cc) {
	case 0:
	case 2:
		return 0;
	case 1:
		return -EBUSY;
	default:
		return -ENODEV;
	}
}
EXPORT_SYMBOL_GPL(cio_tm_intrg);