chsc.c 24.6 KB
Newer Older
Linus Torvalds's avatar
Linus Torvalds committed
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
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
/*
 *  drivers/s390/cio/chsc.c
 *   S/390 common I/O routines -- channel subsystem call
 *   $Revision: 1.119 $
 *
 *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
 *			      IBM Corporation
 *    Author(s): Ingo Adlung (adlung@de.ibm.com)
 *		 Cornelia Huck (cohuck@de.ibm.com)
 *		 Arnd Bergmann (arndb@de.ibm.com)
 */

#include <linux/module.h>
#include <linux/config.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/device.h>

#include <asm/cio.h>

#include "css.h"
#include "cio.h"
#include "cio_debug.h"
#include "ioasm.h"
#include "chsc.h"

static struct channel_path *chps[NR_CHPIDS];

static void *sei_page;

static int new_channel_path(int chpid);

static inline void
set_chp_logically_online(int chp, int onoff)
{
	chps[chp]->state = onoff;
}

static int
get_chp_status(int chp)
{
	return (chps[chp] ? chps[chp]->state : -ENODEV);
}

void
chsc_validate_chpids(struct subchannel *sch)
{
	int mask, chp;

	for (chp = 0; chp <= 7; chp++) {
		mask = 0x80 >> chp;
		if (!get_chp_status(sch->schib.pmcw.chpid[chp]))
			/* disable using this path */
			sch->opm &= ~mask;
	}
}

void
chpid_is_actually_online(int chp)
{
	int state;

	state = get_chp_status(chp);
	if (state < 0) {
		need_rescan = 1;
		queue_work(slow_path_wq, &slow_path_work);
	} else
		WARN_ON(!state);
}

/* FIXME: this is _always_ called for every subchannel. shouldn't we
 *	  process more than one at a time? */
static int
chsc_get_sch_desc_irq(struct subchannel *sch, void *page)
{
	int ccode, j;

	struct {
		struct chsc_header request;
		u16 reserved1;
		u16 f_sch;	  /* first subchannel */
		u16 reserved2;
		u16 l_sch;	  /* last subchannel */
		u32 reserved3;
		struct chsc_header response;
		u32 reserved4;
		u8 sch_valid : 1;
		u8 dev_valid : 1;
		u8 st	     : 3; /* subchannel type */
		u8 zeroes    : 3;
		u8  unit_addr;	  /* unit address */
		u16 devno;	  /* device number */
		u8 path_mask;
		u8 fla_valid_mask;
		u16 sch;	  /* subchannel */
		u8 chpid[8];	  /* chpids 0-7 */
		u16 fla[8];	  /* full link addresses 0-7 */
	} *ssd_area;

	ssd_area = page;

	ssd_area->request = (struct chsc_header) {
		.length = 0x0010,
		.code   = 0x0004,
	};

	ssd_area->f_sch = sch->irq;
	ssd_area->l_sch = sch->irq;

	ccode = chsc(ssd_area);
	if (ccode > 0) {
		pr_debug("chsc returned with ccode = %d\n", ccode);
		return (ccode == 3) ? -ENODEV : -EBUSY;
	}

	switch (ssd_area->response.code) {
	case 0x0001: /* everything ok */
		break;
	case 0x0002:
		CIO_CRW_EVENT(2, "Invalid command!\n");
		return -EINVAL;
	case 0x0003:
		CIO_CRW_EVENT(2, "Error in chsc request block!\n");
		return -EINVAL;
	case 0x0004:
		CIO_CRW_EVENT(2, "Model does not provide ssd\n");
		return -EOPNOTSUPP;
	default:
		CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
			      ssd_area->response.code);
		return -EIO;
	}

	/*
	 * ssd_area->st stores the type of the detected
	 * subchannel, with the following definitions:
	 *
	 * 0: I/O subchannel:	  All fields have meaning
	 * 1: CHSC subchannel:	  Only sch_val, st and sch
	 *			  have meaning
	 * 2: Message subchannel: All fields except unit_addr
	 *			  have meaning
	 * 3: ADM subchannel:	  Only sch_val, st and sch
	 *			  have meaning
	 *
	 * Other types are currently undefined.
	 */
	if (ssd_area->st > 3) { /* uhm, that looks strange... */
		CIO_CRW_EVENT(0, "Strange subchannel type %d"
			      " for sch %04x\n", ssd_area->st, sch->irq);
		/*
		 * There may have been a new subchannel type defined in the
		 * time since this code was written; since we don't know which
		 * fields have meaning and what to do with it we just jump out
		 */
		return 0;
	} else {
		const char *type[4] = {"I/O", "chsc", "message", "ADM"};
		CIO_CRW_EVENT(6, "ssd: sch %04x is %s subchannel\n",
			      sch->irq, type[ssd_area->st]);

		sch->ssd_info.valid = 1;
		sch->ssd_info.type = ssd_area->st;
	}

	if (ssd_area->st == 0 || ssd_area->st == 2) {
		for (j = 0; j < 8; j++) {
			if (!((0x80 >> j) & ssd_area->path_mask &
			      ssd_area->fla_valid_mask))
				continue;
			sch->ssd_info.chpid[j] = ssd_area->chpid[j];
			sch->ssd_info.fla[j]   = ssd_area->fla[j];
		}
	}
	return 0;
}

int
css_get_ssd_info(struct subchannel *sch)
{
	int ret;
	void *page;

	page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
	if (!page)
		return -ENOMEM;
	spin_lock_irq(&sch->lock);
	ret = chsc_get_sch_desc_irq(sch, page);
	if (ret) {
		static int cio_chsc_err_msg;
		
		if (!cio_chsc_err_msg) {
			printk(KERN_ERR
			       "chsc_get_sch_descriptions:"
			       " Error %d while doing chsc; "
			       "processing some machine checks may "
			       "not work\n", ret);
			cio_chsc_err_msg = 1;
		}
	}
	spin_unlock_irq(&sch->lock);
	free_page((unsigned long)page);
	if (!ret) {
		int j, chpid;
		/* Allocate channel path structures, if needed. */
		for (j = 0; j < 8; j++) {
			chpid = sch->ssd_info.chpid[j];
			if (chpid && (get_chp_status(chpid) < 0))
			    new_channel_path(chpid);
		}
	}
	return ret;
}

static int
s390_subchannel_remove_chpid(struct device *dev, void *data)
{
	int j;
	int mask;
	struct subchannel *sch;
	__u8 *chpid;
	struct schib schib;

	sch = to_subchannel(dev);
	chpid = data;
	for (j = 0; j < 8; j++)
		if (sch->schib.pmcw.chpid[j] == *chpid)
			break;
	if (j >= 8)
		return 0;

	mask = 0x80 >> j;
	spin_lock(&sch->lock);

	stsch(sch->irq, &schib);
	if (!schib.pmcw.dnv)
		goto out_unreg;
	memcpy(&sch->schib, &schib, sizeof(struct schib));
	/* Check for single path devices. */
	if (sch->schib.pmcw.pim == 0x80)
		goto out_unreg;
	if (sch->vpm == mask)
		goto out_unreg;

	if ((sch->schib.scsw.actl & (SCSW_ACTL_CLEAR_PEND |
				     SCSW_ACTL_HALT_PEND |
				     SCSW_ACTL_START_PEND |
				     SCSW_ACTL_RESUME_PEND)) &&
	    (sch->schib.pmcw.lpum == mask)) {
		int cc = cio_cancel(sch);
		
		if (cc == -ENODEV)
			goto out_unreg;

		if (cc == -EINVAL) {
			cc = cio_clear(sch);
			if (cc == -ENODEV)
				goto out_unreg;
			/* Call handler. */
			if (sch->driver && sch->driver->termination)
				sch->driver->termination(&sch->dev);
			goto out_unlock;
		}
	} else if ((sch->schib.scsw.actl & SCSW_ACTL_DEVACT) &&
		   (sch->schib.scsw.actl & SCSW_ACTL_SCHACT) &&
		   (sch->schib.pmcw.lpum == mask)) {
		int cc;

		cc = cio_clear(sch);
		if (cc == -ENODEV)
			goto out_unreg;
		/* Call handler. */
		if (sch->driver && sch->driver->termination)
			sch->driver->termination(&sch->dev);
		goto out_unlock;
	}

	/* trigger path verification. */
	if (sch->driver && sch->driver->verify)
		sch->driver->verify(&sch->dev);
out_unlock:
	spin_unlock(&sch->lock);
	return 0;
out_unreg:
	spin_unlock(&sch->lock);
	sch->lpm = 0;
	if (css_enqueue_subchannel_slow(sch->irq)) {
		css_clear_subchannel_slow_list();
		need_rescan = 1;
	}
	return 0;
}

static inline void
s390_set_chpid_offline( __u8 chpid)
{
	char dbf_txt[15];

	sprintf(dbf_txt, "chpr%x", chpid);
	CIO_TRACE_EVENT(2, dbf_txt);

	if (get_chp_status(chpid) <= 0)
		return;

	bus_for_each_dev(&css_bus_type, NULL, &chpid,
			 s390_subchannel_remove_chpid);

	if (need_rescan || css_slow_subchannels_exist())
		queue_work(slow_path_wq, &slow_path_work);
}

static int
s390_process_res_acc_sch(u8 chpid, __u16 fla, u32 fla_mask,
			 struct subchannel *sch)
{
	int found;
	int chp;
	int ccode;
	
	found = 0;
	for (chp = 0; chp <= 7; chp++)
		/*
		 * check if chpid is in information updated by ssd
		 */
		if (sch->ssd_info.valid &&
		    sch->ssd_info.chpid[chp] == chpid &&
		    (sch->ssd_info.fla[chp] & fla_mask) == fla) {
			found = 1;
			break;
		}
	
	if (found == 0)
		return 0;

	/*
	 * Do a stsch to update our subchannel structure with the
	 * new path information and eventually check for logically
	 * offline chpids.
	 */
	ccode = stsch(sch->irq, &sch->schib);
	if (ccode > 0)
		return 0;

	return 0x80 >> chp;
}

static int
s390_process_res_acc (u8 chpid, __u16 fla, u32 fla_mask)
{
	struct subchannel *sch;
	int irq, rc;
	char dbf_txt[15];

	sprintf(dbf_txt, "accpr%x", chpid);
	CIO_TRACE_EVENT( 2, dbf_txt);
	if (fla != 0) {
		sprintf(dbf_txt, "fla%x", fla);
		CIO_TRACE_EVENT( 2, dbf_txt);
	}

	/*
	 * I/O resources may have become accessible.
	 * Scan through all subchannels that may be concerned and
	 * do a validation on those.
	 * The more information we have (info), the less scanning
	 * will we have to do.
	 */

	if (!get_chp_status(chpid))
		return 0; /* no need to do the rest */

	rc = 0;
	for (irq = 0; irq < __MAX_SUBCHANNELS; irq++) {
		int chp_mask, old_lpm;

		sch = get_subchannel_by_schid(irq);
		if (!sch) {
			struct schib schib;
			int ret;
			/*
			 * We don't know the device yet, but since a path
			 * may be available now to the device we'll have
			 * to do recognition again.
			 * Since we don't have any idea about which chpid
			 * that beast may be on we'll have to do a stsch
			 * on all devices, grr...
			 */
			if (stsch(irq, &schib)) {
				/* We're through */
				if (need_rescan)
					rc = -EAGAIN;
				break;
			}
			if (need_rescan) {
				rc = -EAGAIN;
				continue;
			}
			/* Put it on the slow path. */
			ret = css_enqueue_subchannel_slow(irq);
			if (ret) {
				css_clear_subchannel_slow_list();
				need_rescan = 1;
			}
			rc = -EAGAIN;
			continue;
		}
	
		spin_lock_irq(&sch->lock);

		chp_mask = s390_process_res_acc_sch(chpid, fla, fla_mask, sch);

		if (chp_mask == 0) {

			spin_unlock_irq(&sch->lock);

			if (fla_mask != 0)
				break;
			else
				continue;
		}
		old_lpm = sch->lpm;
		sch->lpm = ((sch->schib.pmcw.pim &
			     sch->schib.pmcw.pam &
			     sch->schib.pmcw.pom)
			    | chp_mask) & sch->opm;
		if (!old_lpm && sch->lpm)
			device_trigger_reprobe(sch);
		else if (sch->driver && sch->driver->verify)
			sch->driver->verify(&sch->dev);

		spin_unlock_irq(&sch->lock);
		put_device(&sch->dev);
		if (fla_mask != 0)
			break;
	}
	return rc;
}

static int
__get_chpid_from_lir(void *data)
{
	struct lir {
		u8  iq;
		u8  ic;
		u16 sci;
		/* incident-node descriptor */
		u32 indesc[28];
		/* attached-node descriptor */
		u32 andesc[28];
		/* incident-specific information */
		u32 isinfo[28];
	} *lir;

	lir = (struct lir*) data;
	if (!(lir->iq&0x80))
		/* NULL link incident record */
		return -EINVAL;
	if (!(lir->indesc[0]&0xc0000000))
		/* node descriptor not valid */
		return -EINVAL;
	if (!(lir->indesc[0]&0x10000000))
		/* don't handle device-type nodes - FIXME */
		return -EINVAL;
	/* Byte 3 contains the chpid. Could also be CTCA, but we don't care */

	return (u16) (lir->indesc[0]&0x000000ff);
}

int
chsc_process_crw(void)
{
	int chpid, ret;
	struct {
		struct chsc_header request;
		u32 reserved1;
		u32 reserved2;
		u32 reserved3;
		struct chsc_header response;
		u32 reserved4;
		u8  flags;
		u8  vf;		/* validity flags */
		u8  rs;		/* reporting source */
		u8  cc;		/* content code */
		u16 fla;	/* full link address */
		u16 rsid;	/* reporting source id */
		u32 reserved5;
		u32 reserved6;
		u32 ccdf[96];	/* content-code dependent field */
		/* ccdf has to be big enough for a link-incident record */
	} *sei_area;

	if (!sei_page)
		return 0;
	/*
	 * build the chsc request block for store event information
	 * and do the call
	 * This function is only called by the machine check handler thread,
	 * so we don't need locking for the sei_page.
	 */
	sei_area = sei_page;

	CIO_TRACE_EVENT( 2, "prcss");
	ret = 0;
	do {
		int ccode, status;
		memset(sei_area, 0, sizeof(*sei_area));

		sei_area->request = (struct chsc_header) {
			.length = 0x0010,
			.code   = 0x000e,
		};

		ccode = chsc(sei_area);
		if (ccode > 0)
			return 0;

		switch (sei_area->response.code) {
			/* for debug purposes, check for problems */
		case 0x0001:
			CIO_CRW_EVENT(4, "chsc_process_crw: event information "
					"successfully stored\n");
			break; /* everything ok */
		case 0x0002:
			CIO_CRW_EVENT(2,
				      "chsc_process_crw: invalid command!\n");
			return 0;
		case 0x0003:
			CIO_CRW_EVENT(2, "chsc_process_crw: error in chsc "
				      "request block!\n");
			return 0;
		case 0x0005:
			CIO_CRW_EVENT(2, "chsc_process_crw: no event "
				      "information stored\n");
			return 0;
		default:
			CIO_CRW_EVENT(2, "chsc_process_crw: chsc response %d\n",
				      sei_area->response.code);
			return 0;
		}

		/* Check if we might have lost some information. */
		if (sei_area->flags & 0x40)
			CIO_CRW_EVENT(2, "chsc_process_crw: Event information "
				       "has been lost due to overflow!\n");

		if (sei_area->rs != 4) {
			CIO_CRW_EVENT(2, "chsc_process_crw: reporting source "
				      "(%04X) isn't a chpid!\n",
				      sei_area->rsid);
			continue;
		}

		/* which kind of information was stored? */
		switch (sei_area->cc) {
		case 1: /* link incident*/
			CIO_CRW_EVENT(4, "chsc_process_crw: "
				      "channel subsystem reports link incident,"
				      " reporting source is chpid %x\n",
				      sei_area->rsid);
			chpid = __get_chpid_from_lir(sei_area->ccdf);
			if (chpid < 0)
				CIO_CRW_EVENT(4, "%s: Invalid LIR, skipping\n",
					      __FUNCTION__);
			else
				s390_set_chpid_offline(chpid);
			break;
			
		case 2: /* i/o resource accessibiliy */
			CIO_CRW_EVENT(4, "chsc_process_crw: "
				      "channel subsystem reports some I/O "
				      "devices may have become accessible\n");
			pr_debug("Data received after sei: \n");
			pr_debug("Validity flags: %x\n", sei_area->vf);
			
			/* allocate a new channel path structure, if needed */
			status = get_chp_status(sei_area->rsid);
			if (status < 0)
				new_channel_path(sei_area->rsid);
			else if (!status)
				return 0;
			if ((sei_area->vf & 0x80) == 0) {
				pr_debug("chpid: %x\n", sei_area->rsid);
				ret = s390_process_res_acc(sei_area->rsid,
							   0, 0);
			} else if ((sei_area->vf & 0xc0) == 0x80) {
				pr_debug("chpid: %x link addr: %x\n",
					 sei_area->rsid, sei_area->fla);
				ret = s390_process_res_acc(sei_area->rsid,
							   sei_area->fla,
							   0xff00);
			} else if ((sei_area->vf & 0xc0) == 0xc0) {
				pr_debug("chpid: %x full link addr: %x\n",
					 sei_area->rsid, sei_area->fla);
				ret = s390_process_res_acc(sei_area->rsid,
							   sei_area->fla,
							   0xffff);
			}
			pr_debug("\n");
			
			break;
			
		default: /* other stuff */
			CIO_CRW_EVENT(4, "chsc_process_crw: event %d\n",
				      sei_area->cc);
			break;
		}
	} while (sei_area->flags & 0x80);
	return ret;
}

static int
chp_add(int chpid)
{
	struct subchannel *sch;
	int irq, ret, rc;
	char dbf_txt[15];

	if (!get_chp_status(chpid))
		return 0; /* no need to do the rest */
	
	sprintf(dbf_txt, "cadd%x", chpid);
	CIO_TRACE_EVENT(2, dbf_txt);

	rc = 0;
	for (irq = 0; irq < __MAX_SUBCHANNELS; irq++) {
		int i;

		sch = get_subchannel_by_schid(irq);
		if (!sch) {
			struct schib schib;

			if (stsch(irq, &schib)) {
				/* We're through */
				if (need_rescan)
					rc = -EAGAIN;
				break;
			}
			if (need_rescan) {
				rc = -EAGAIN;
				continue;
			}
			/* Put it on the slow path. */
			ret = css_enqueue_subchannel_slow(irq);
			if (ret) {
				css_clear_subchannel_slow_list();
				need_rescan = 1;
			}
			rc = -EAGAIN;
			continue;
		}
	
		spin_lock(&sch->lock);
		for (i=0; i<8; i++)
			if (sch->schib.pmcw.chpid[i] == chpid) {
				if (stsch(sch->irq, &sch->schib) != 0) {
					/* Endgame. */
					spin_unlock(&sch->lock);
					return rc;
				}
				break;
			}
		if (i==8) {
			spin_unlock(&sch->lock);
			return rc;
		}
		sch->lpm = ((sch->schib.pmcw.pim &
			     sch->schib.pmcw.pam &
			     sch->schib.pmcw.pom)
			    | 0x80 >> i) & sch->opm;

		if (sch->driver && sch->driver->verify)
			sch->driver->verify(&sch->dev);

		spin_unlock(&sch->lock);
		put_device(&sch->dev);
	}
	return rc;
}

/* 
 * Handling of crw machine checks with channel path source.
 */
int
chp_process_crw(int chpid, int on)
{
	if (on == 0) {
		/* Path has gone. We use the link incident routine.*/
		s390_set_chpid_offline(chpid);
		return 0; /* De-register is async anyway. */
	}
	/*
	 * Path has come. Allocate a new channel path structure,
	 * if needed.
	 */
	if (get_chp_status(chpid) < 0)
		new_channel_path(chpid);
	/* Avoid the extra overhead in process_rec_acc. */
	return chp_add(chpid);
}

static inline int
__check_for_io_and_kill(struct subchannel *sch, int index)
{
	int cc;

	if (!device_is_online(sch))
		/* cio could be doing I/O. */
		return 0;
	cc = stsch(sch->irq, &sch->schib);
	if (cc)
		return 0;
	if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index)) {
		device_set_waiting(sch);
		return 1;
	}
	return 0;
}

static inline void
__s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
{
	int chp, old_lpm;
	unsigned long flags;

	if (!sch->ssd_info.valid)
		return;
	
	spin_lock_irqsave(&sch->lock, flags);
	old_lpm = sch->lpm;
	for (chp = 0; chp < 8; chp++) {
		if (sch->ssd_info.chpid[chp] != chpid)
			continue;

		if (on) {
			sch->opm |= (0x80 >> chp);
			sch->lpm |= (0x80 >> chp);
			if (!old_lpm)
				device_trigger_reprobe(sch);
			else if (sch->driver && sch->driver->verify)
				sch->driver->verify(&sch->dev);
		} else {
			sch->opm &= ~(0x80 >> chp);
			sch->lpm &= ~(0x80 >> chp);
			/*
			 * Give running I/O a grace period in which it
			 * can successfully terminate, even using the
			 * just varied off path. Then kill it.
			 */
			if (!__check_for_io_and_kill(sch, chp) && !sch->lpm) {
				if (css_enqueue_subchannel_slow(sch->irq)) {
					css_clear_subchannel_slow_list();
					need_rescan = 1;
				}
			} else if (sch->driver && sch->driver->verify)
				sch->driver->verify(&sch->dev);
		}
		break;
	}
	spin_unlock_irqrestore(&sch->lock, flags);
}

static int
s390_subchannel_vary_chpid_off(struct device *dev, void *data)
{
	struct subchannel *sch;
	__u8 *chpid;

	sch = to_subchannel(dev);
	chpid = data;

	__s390_subchannel_vary_chpid(sch, *chpid, 0);
	return 0;
}

static int
s390_subchannel_vary_chpid_on(struct device *dev, void *data)
{
	struct subchannel *sch;
	__u8 *chpid;

	sch = to_subchannel(dev);
	chpid = data;

	__s390_subchannel_vary_chpid(sch, *chpid, 1);
	return 0;
}

/*
 * Function: s390_vary_chpid
 * Varies the specified chpid online or offline
 */
static int
s390_vary_chpid( __u8 chpid, int on)
{
	char dbf_text[15];
	int status, irq, ret;
	struct subchannel *sch;

	sprintf(dbf_text, on?"varyon%x":"varyoff%x", chpid);
	CIO_TRACE_EVENT( 2, dbf_text);

	status = get_chp_status(chpid);
	if (status < 0) {
		printk(KERN_ERR "Can't vary unknown chpid %02X\n", chpid);
		return -EINVAL;
	}

	if (!on && !status) {
		printk(KERN_ERR "chpid %x is already offline\n", chpid);
		return -EINVAL;
	}

	set_chp_logically_online(chpid, on);

	/*
	 * Redo PathVerification on the devices the chpid connects to
	 */

	bus_for_each_dev(&css_bus_type, NULL, &chpid, on ?
			 s390_subchannel_vary_chpid_on :
			 s390_subchannel_vary_chpid_off);
	if (!on)
		goto out;
	/* Scan for new devices on varied on path. */
	for (irq = 0; irq < __MAX_SUBCHANNELS; irq++) {
		struct schib schib;

		if (need_rescan)
			break;
		sch = get_subchannel_by_schid(irq);
		if (sch) {
			put_device(&sch->dev);
			continue;
		}
		if (stsch(irq, &schib))
			/* We're through */
			break;
		/* Put it on the slow path. */
		ret = css_enqueue_subchannel_slow(irq);
		if (ret) {
			css_clear_subchannel_slow_list();
			need_rescan = 1;
		}
	}
out:
	if (need_rescan || css_slow_subchannels_exist())
		queue_work(slow_path_wq, &slow_path_work);
	return 0;
}

/*
 * Files for the channel path entries.
 */
static ssize_t
855
chp_status_show(struct device *dev, struct device_attribute *attr, char *buf)
Linus Torvalds's avatar
Linus Torvalds committed
856
857
858
859
860
861
862
863
864
865
{
	struct channel_path *chp = container_of(dev, struct channel_path, dev);

	if (!chp)
		return 0;
	return (get_chp_status(chp->id) ? sprintf(buf, "online\n") :
		sprintf(buf, "offline\n"));
}

static ssize_t
866
chp_status_write(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
Linus Torvalds's avatar
Linus Torvalds committed
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
{
	struct channel_path *cp = container_of(dev, struct channel_path, dev);
	char cmd[10];
	int num_args;
	int error;

	num_args = sscanf(buf, "%5s", cmd);
	if (!num_args)
		return count;

	if (!strnicmp(cmd, "on", 2))
		error = s390_vary_chpid(cp->id, 1);
	else if (!strnicmp(cmd, "off", 3))
		error = s390_vary_chpid(cp->id, 0);
	else
		error = -EINVAL;

	return error < 0 ? error : count;

}

static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);

static ssize_t
891
chp_type_show(struct device *dev, struct device_attribute *attr, char *buf)
Linus Torvalds's avatar
Linus Torvalds committed
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
{
	struct channel_path *chp = container_of(dev, struct channel_path, dev);

	if (!chp)
		return 0;
	return sprintf(buf, "%x\n", chp->desc.desc);
}

static DEVICE_ATTR(type, 0444, chp_type_show, NULL);

static struct attribute * chp_attrs[] = {
	&dev_attr_status.attr,
	&dev_attr_type.attr,
	NULL,
};

static struct attribute_group chp_attr_group = {
	.attrs = chp_attrs,
};

static void
chp_release(struct device *dev)
{
	struct channel_path *cp;
	
	cp = container_of(dev, struct channel_path, dev);
	kfree(cp);
}

static int
chsc_determine_channel_path_description(int chpid,
					struct channel_path_desc *desc)
{
	int ccode, ret;

	struct {
		struct chsc_header request;
		u32 : 24;
		u32 first_chpid : 8;
		u32 : 24;
		u32 last_chpid : 8;
		u32 zeroes1;
		struct chsc_header response;
		u32 zeroes2;
		struct channel_path_desc desc;
	} *scpd_area;

	scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
	if (!scpd_area)
		return -ENOMEM;

	scpd_area->request = (struct chsc_header) {
		.length = 0x0010,
		.code   = 0x0002,
	};

	scpd_area->first_chpid = chpid;
	scpd_area->last_chpid = chpid;

	ccode = chsc(scpd_area);
	if (ccode > 0) {
		ret = (ccode == 3) ? -ENODEV : -EBUSY;
		goto out;
	}

	switch (scpd_area->response.code) {
	case 0x0001: /* Success. */
		memcpy(desc, &scpd_area->desc,
		       sizeof(struct channel_path_desc));
		ret = 0;
		break;
	case 0x0003: /* Invalid block. */
	case 0x0007: /* Invalid format. */
	case 0x0008: /* Other invalid block. */
		CIO_CRW_EVENT(2, "Error in chsc request block!\n");
		ret = -EINVAL;
		break;
	case 0x0004: /* Command not provided in model. */
		CIO_CRW_EVENT(2, "Model does not provide scpd\n");
		ret = -EOPNOTSUPP;
		break;
	default:
		CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
			      scpd_area->response.code);
		ret = -EIO;
	}
out:
	free_page((unsigned long)scpd_area);
	return ret;
}

/*
 * Entries for chpids on the system bus.
 * This replaces /proc/chpids.
 */
static int
new_channel_path(int chpid)
{
	struct channel_path *chp;
	int ret;

	chp = kmalloc(sizeof(struct channel_path), GFP_KERNEL);
	if (!chp)
		return -ENOMEM;
	memset(chp, 0, sizeof(struct channel_path));

	/* fill in status, etc. */
	chp->id = chpid;
	chp->state = 1;
	chp->dev = (struct device) {
		.parent  = &css_bus_device,
		.release = chp_release,
	};
	snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp0.%x", chpid);

	/* Obtain channel path description and fill it in. */
	ret = chsc_determine_channel_path_description(chpid, &chp->desc);
	if (ret)
		goto out_free;

	/* make it known to the system */
	ret = device_register(&chp->dev);
	if (ret) {
		printk(KERN_WARNING "%s: could not register %02x\n",
		       __func__, chpid);
		goto out_free;
	}
	ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
	if (ret) {
		device_unregister(&chp->dev);
		goto out_free;
	} else
		chps[chpid] = chp;
	return ret;
out_free:
	kfree(chp);
	return ret;
}

void *
chsc_get_chp_desc(struct subchannel *sch, int chp_no)
{
	struct channel_path *chp;
	struct channel_path_desc *desc;

	chp = chps[sch->schib.pmcw.chpid[chp_no]];
	if (!chp)
		return NULL;
	desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
	if (!desc)
		return NULL;
	memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
	return desc;
}


static int __init
chsc_alloc_sei_area(void)
{
	sei_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
	if (!sei_page)
		printk(KERN_WARNING"Can't allocate page for processing of " \
		       "chsc machine checks!\n");
	return (sei_page ? 0 : -ENOMEM);
}

subsys_initcall(chsc_alloc_sei_area);

struct css_general_char css_general_characteristics;
struct css_chsc_char css_chsc_characteristics;

int __init
chsc_determine_css_characteristics(void)
{
	int result;
	struct {
		struct chsc_header request;
		u32 reserved1;
		u32 reserved2;
		u32 reserved3;
		struct chsc_header response;
		u32 reserved4;
		u32 general_char[510];
		u32 chsc_char[518];
	} *scsc_area;

	scsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
	if (!scsc_area) {
	        printk(KERN_WARNING"cio: Was not able to determine available" \
		       "CHSCs due to no memory.\n");
		return -ENOMEM;
	}

	scsc_area->request = (struct chsc_header) {
		.length = 0x0010,
		.code   = 0x0010,
	};

	result = chsc(scsc_area);
	if (result) {
		printk(KERN_WARNING"cio: Was not able to determine " \
		       "available CHSCs, cc=%i.\n", result);
		result = -EIO;
		goto exit;
	}

	if (scsc_area->response.code != 1) {
		printk(KERN_WARNING"cio: Was not able to determine " \
		       "available CHSCs.\n");
		result = -EIO;
		goto exit;
	}
	memcpy(&css_general_characteristics, scsc_area->general_char,
	       sizeof(css_general_characteristics));
	memcpy(&css_chsc_characteristics, scsc_area->chsc_char,
	       sizeof(css_chsc_characteristics));
exit:
	free_page ((unsigned long) scsc_area);
	return result;
}

EXPORT_SYMBOL_GPL(css_general_characteristics);
EXPORT_SYMBOL_GPL(css_chsc_characteristics);