xref: /linux/drivers/s390/cio/cio.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8) 
1 /*
2  *  drivers/s390/cio/cio.c
3  *   S/390 common I/O routines -- low level i/o calls
4  *
5  *    Copyright IBM Corp. 1999,2008
6  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
7  *		 Cornelia Huck (cornelia.huck@de.ibm.com)
8  *		 Arnd Bergmann (arndb@de.ibm.com)
9  *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
10  */
11 
12 #define KMSG_COMPONENT "cio"
13 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
14 
15 #include <linux/ftrace.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/slab.h>
19 #include <linux/device.h>
20 #include <linux/kernel_stat.h>
21 #include <linux/interrupt.h>
22 #include <asm/cio.h>
23 #include <asm/delay.h>
24 #include <asm/irq.h>
25 #include <asm/irq_regs.h>
26 #include <asm/setup.h>
27 #include <asm/reset.h>
28 #include <asm/ipl.h>
29 #include <asm/chpid.h>
30 #include <asm/airq.h>
31 #include <asm/isc.h>
32 #include <asm/cputime.h>
33 #include <asm/fcx.h>
34 #include <asm/nmi.h>
35 #include <asm/crw.h>
36 #include "cio.h"
37 #include "css.h"
38 #include "chsc.h"
39 #include "ioasm.h"
40 #include "io_sch.h"
41 #include "blacklist.h"
42 #include "cio_debug.h"
43 #include "chp.h"
44 
45 debug_info_t *cio_debug_msg_id;
46 debug_info_t *cio_debug_trace_id;
47 debug_info_t *cio_debug_crw_id;
48 
49 /*
50  * Function: cio_debug_init
51  * Initializes three debug logs for common I/O:
52  * - cio_msg logs generic cio messages
53  * - cio_trace logs the calling of different functions
54  * - cio_crw logs machine check related cio messages
55  */
56 static int __init cio_debug_init(void)
57 {
58 	cio_debug_msg_id = debug_register("cio_msg", 16, 1, 16 * sizeof(long));
59 	if (!cio_debug_msg_id)
60 		goto out_unregister;
61 	debug_register_view(cio_debug_msg_id, &debug_sprintf_view);
62 	debug_set_level(cio_debug_msg_id, 2);
63 	cio_debug_trace_id = debug_register("cio_trace", 16, 1, 16);
64 	if (!cio_debug_trace_id)
65 		goto out_unregister;
66 	debug_register_view(cio_debug_trace_id, &debug_hex_ascii_view);
67 	debug_set_level(cio_debug_trace_id, 2);
68 	cio_debug_crw_id = debug_register("cio_crw", 16, 1, 16 * sizeof(long));
69 	if (!cio_debug_crw_id)
70 		goto out_unregister;
71 	debug_register_view(cio_debug_crw_id, &debug_sprintf_view);
72 	debug_set_level(cio_debug_crw_id, 4);
73 	return 0;
74 
75 out_unregister:
76 	if (cio_debug_msg_id)
77 		debug_unregister(cio_debug_msg_id);
78 	if (cio_debug_trace_id)
79 		debug_unregister(cio_debug_trace_id);
80 	if (cio_debug_crw_id)
81 		debug_unregister(cio_debug_crw_id);
82 	return -1;
83 }
84 
85 arch_initcall (cio_debug_init);
86 
87 int cio_set_options(struct subchannel *sch, int flags)
88 {
89 	struct io_subchannel_private *priv = to_io_private(sch);
90 
91 	priv->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
92 	priv->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
93 	priv->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
94 	return 0;
95 }
96 
97 static int
98 cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
99 {
100 	char dbf_text[15];
101 
102 	if (lpm != 0)
103 		sch->lpm &= ~lpm;
104 	else
105 		sch->lpm = 0;
106 
107 	CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
108 		      "subchannel 0.%x.%04x!\n", sch->schid.ssid,
109 		      sch->schid.sch_no);
110 
111 	if (cio_update_schib(sch))
112 		return -ENODEV;
113 
114 	sprintf(dbf_text, "no%s", dev_name(&sch->dev));
115 	CIO_TRACE_EVENT(0, dbf_text);
116 	CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
117 
118 	return (sch->lpm ? -EACCES : -ENODEV);
119 }
120 
121 int
122 cio_start_key (struct subchannel *sch,	/* subchannel structure */
123 	       struct ccw1 * cpa,	/* logical channel prog addr */
124 	       __u8 lpm,		/* logical path mask */
125 	       __u8 key)                /* storage key */
126 {
127 	struct io_subchannel_private *priv = to_io_private(sch);
128 	union orb *orb = &priv->orb;
129 	int ccode;
130 
131 	CIO_TRACE_EVENT(5, "stIO");
132 	CIO_TRACE_EVENT(5, dev_name(&sch->dev));
133 
134 	memset(orb, 0, sizeof(union orb));
135 	/* sch is always under 2G. */
136 	orb->cmd.intparm = (u32)(addr_t)sch;
137 	orb->cmd.fmt = 1;
138 
139 	orb->cmd.pfch = priv->options.prefetch == 0;
140 	orb->cmd.spnd = priv->options.suspend;
141 	orb->cmd.ssic = priv->options.suspend && priv->options.inter;
142 	orb->cmd.lpm = (lpm != 0) ? lpm : sch->lpm;
143 #ifdef CONFIG_64BIT
144 	/*
145 	 * for 64 bit we always support 64 bit IDAWs with 4k page size only
146 	 */
147 	orb->cmd.c64 = 1;
148 	orb->cmd.i2k = 0;
149 #endif
150 	orb->cmd.key = key >> 4;
151 	/* issue "Start Subchannel" */
152 	orb->cmd.cpa = (__u32) __pa(cpa);
153 	ccode = ssch(sch->schid, orb);
154 
155 	/* process condition code */
156 	CIO_HEX_EVENT(5, &ccode, sizeof(ccode));
157 
158 	switch (ccode) {
159 	case 0:
160 		/*
161 		 * initialize device status information
162 		 */
163 		sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
164 		return 0;
165 	case 1:		/* status pending */
166 	case 2:		/* busy */
167 		return -EBUSY;
168 	case 3:		/* device/path not operational */
169 		return cio_start_handle_notoper(sch, lpm);
170 	default:
171 		return ccode;
172 	}
173 }
174 
175 int
176 cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
177 {
178 	return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
179 }
180 
181 /*
182  * resume suspended I/O operation
183  */
184 int
185 cio_resume (struct subchannel *sch)
186 {
187 	int ccode;
188 
189 	CIO_TRACE_EVENT(4, "resIO");
190 	CIO_TRACE_EVENT(4, dev_name(&sch->dev));
191 
192 	ccode = rsch (sch->schid);
193 
194 	CIO_HEX_EVENT(4, &ccode, sizeof(ccode));
195 
196 	switch (ccode) {
197 	case 0:
198 		sch->schib.scsw.cmd.actl |= SCSW_ACTL_RESUME_PEND;
199 		return 0;
200 	case 1:
201 		return -EBUSY;
202 	case 2:
203 		return -EINVAL;
204 	default:
205 		/*
206 		 * useless to wait for request completion
207 		 *  as device is no longer operational !
208 		 */
209 		return -ENODEV;
210 	}
211 }
212 
213 /*
214  * halt I/O operation
215  */
216 int
217 cio_halt(struct subchannel *sch)
218 {
219 	int ccode;
220 
221 	if (!sch)
222 		return -ENODEV;
223 
224 	CIO_TRACE_EVENT(2, "haltIO");
225 	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
226 
227 	/*
228 	 * Issue "Halt subchannel" and process condition code
229 	 */
230 	ccode = hsch (sch->schid);
231 
232 	CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
233 
234 	switch (ccode) {
235 	case 0:
236 		sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND;
237 		return 0;
238 	case 1:		/* status pending */
239 	case 2:		/* busy */
240 		return -EBUSY;
241 	default:		/* device not operational */
242 		return -ENODEV;
243 	}
244 }
245 
246 /*
247  * Clear I/O operation
248  */
249 int
250 cio_clear(struct subchannel *sch)
251 {
252 	int ccode;
253 
254 	if (!sch)
255 		return -ENODEV;
256 
257 	CIO_TRACE_EVENT(2, "clearIO");
258 	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
259 
260 	/*
261 	 * Issue "Clear subchannel" and process condition code
262 	 */
263 	ccode = csch (sch->schid);
264 
265 	CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
266 
267 	switch (ccode) {
268 	case 0:
269 		sch->schib.scsw.cmd.actl |= SCSW_ACTL_CLEAR_PEND;
270 		return 0;
271 	default:		/* device not operational */
272 		return -ENODEV;
273 	}
274 }
275 
276 /*
277  * Function: cio_cancel
278  * Issues a "Cancel Subchannel" on the specified subchannel
279  * Note: We don't need any fancy intparms and flags here
280  *	 since xsch is executed synchronously.
281  * Only for common I/O internal use as for now.
282  */
283 int
284 cio_cancel (struct subchannel *sch)
285 {
286 	int ccode;
287 
288 	if (!sch)
289 		return -ENODEV;
290 
291 	CIO_TRACE_EVENT(2, "cancelIO");
292 	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
293 
294 	ccode = xsch (sch->schid);
295 
296 	CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
297 
298 	switch (ccode) {
299 	case 0:		/* success */
300 		/* Update information in scsw. */
301 		if (cio_update_schib(sch))
302 			return -ENODEV;
303 		return 0;
304 	case 1:		/* status pending */
305 		return -EBUSY;
306 	case 2:		/* not applicable */
307 		return -EINVAL;
308 	default:	/* not oper */
309 		return -ENODEV;
310 	}
311 }
312 
313 
314 static void cio_apply_config(struct subchannel *sch, struct schib *schib)
315 {
316 	schib->pmcw.intparm = sch->config.intparm;
317 	schib->pmcw.mbi = sch->config.mbi;
318 	schib->pmcw.isc = sch->config.isc;
319 	schib->pmcw.ena = sch->config.ena;
320 	schib->pmcw.mme = sch->config.mme;
321 	schib->pmcw.mp = sch->config.mp;
322 	schib->pmcw.csense = sch->config.csense;
323 	schib->pmcw.mbfc = sch->config.mbfc;
324 	if (sch->config.mbfc)
325 		schib->mba = sch->config.mba;
326 }
327 
328 static int cio_check_config(struct subchannel *sch, struct schib *schib)
329 {
330 	return (schib->pmcw.intparm == sch->config.intparm) &&
331 		(schib->pmcw.mbi == sch->config.mbi) &&
332 		(schib->pmcw.isc == sch->config.isc) &&
333 		(schib->pmcw.ena == sch->config.ena) &&
334 		(schib->pmcw.mme == sch->config.mme) &&
335 		(schib->pmcw.mp == sch->config.mp) &&
336 		(schib->pmcw.csense == sch->config.csense) &&
337 		(schib->pmcw.mbfc == sch->config.mbfc) &&
338 		(!sch->config.mbfc || (schib->mba == sch->config.mba));
339 }
340 
341 /*
342  * cio_commit_config - apply configuration to the subchannel
343  */
344 int cio_commit_config(struct subchannel *sch)
345 {
346 	struct schib schib;
347 	int ccode, retry, ret = 0;
348 
349 	if (stsch_err(sch->schid, &schib) || !css_sch_is_valid(&schib))
350 		return -ENODEV;
351 
352 	for (retry = 0; retry < 5; retry++) {
353 		/* copy desired changes to local schib */
354 		cio_apply_config(sch, &schib);
355 		ccode = msch_err(sch->schid, &schib);
356 		if (ccode < 0) /* -EIO if msch gets a program check. */
357 			return ccode;
358 		switch (ccode) {
359 		case 0: /* successful */
360 			if (stsch_err(sch->schid, &schib) ||
361 			    !css_sch_is_valid(&schib))
362 				return -ENODEV;
363 			if (cio_check_config(sch, &schib)) {
364 				/* commit changes from local schib */
365 				memcpy(&sch->schib, &schib, sizeof(schib));
366 				return 0;
367 			}
368 			ret = -EAGAIN;
369 			break;
370 		case 1: /* status pending */
371 			return -EBUSY;
372 		case 2: /* busy */
373 			udelay(100); /* allow for recovery */
374 			ret = -EBUSY;
375 			break;
376 		case 3: /* not operational */
377 			return -ENODEV;
378 		}
379 	}
380 	return ret;
381 }
382 
383 /**
384  * cio_update_schib - Perform stsch and update schib if subchannel is valid.
385  * @sch: subchannel on which to perform stsch
386  * Return zero on success, -ENODEV otherwise.
387  */
388 int cio_update_schib(struct subchannel *sch)
389 {
390 	struct schib schib;
391 
392 	if (stsch_err(sch->schid, &schib) || !css_sch_is_valid(&schib))
393 		return -ENODEV;
394 
395 	memcpy(&sch->schib, &schib, sizeof(schib));
396 	return 0;
397 }
398 EXPORT_SYMBOL_GPL(cio_update_schib);
399 
400 /**
401  * cio_enable_subchannel - enable a subchannel.
402  * @sch: subchannel to be enabled
403  * @intparm: interruption parameter to set
404  */
405 int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
406 {
407 	int retry;
408 	int ret;
409 
410 	CIO_TRACE_EVENT(2, "ensch");
411 	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
412 
413 	if (sch_is_pseudo_sch(sch))
414 		return -EINVAL;
415 	if (cio_update_schib(sch))
416 		return -ENODEV;
417 
418 	sch->config.ena = 1;
419 	sch->config.isc = sch->isc;
420 	sch->config.intparm = intparm;
421 
422 	for (retry = 0; retry < 3; retry++) {
423 		ret = cio_commit_config(sch);
424 		if (ret == -EIO) {
425 			/*
426 			 * Got a program check in msch. Try without
427 			 * the concurrent sense bit the next time.
428 			 */
429 			sch->config.csense = 0;
430 		} else if (ret == -EBUSY) {
431 			struct irb irb;
432 			if (tsch(sch->schid, &irb) != 0)
433 				break;
434 		} else
435 			break;
436 	}
437 	CIO_HEX_EVENT(2, &ret, sizeof(ret));
438 	return ret;
439 }
440 EXPORT_SYMBOL_GPL(cio_enable_subchannel);
441 
442 /**
443  * cio_disable_subchannel - disable a subchannel.
444  * @sch: subchannel to disable
445  */
446 int cio_disable_subchannel(struct subchannel *sch)
447 {
448 	int retry;
449 	int ret;
450 
451 	CIO_TRACE_EVENT(2, "dissch");
452 	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
453 
454 	if (sch_is_pseudo_sch(sch))
455 		return 0;
456 	if (cio_update_schib(sch))
457 		return -ENODEV;
458 
459 	sch->config.ena = 0;
460 
461 	for (retry = 0; retry < 3; retry++) {
462 		ret = cio_commit_config(sch);
463 		if (ret == -EBUSY) {
464 			struct irb irb;
465 			if (tsch(sch->schid, &irb) != 0)
466 				break;
467 		} else
468 			break;
469 	}
470 	CIO_HEX_EVENT(2, &ret, sizeof(ret));
471 	return ret;
472 }
473 EXPORT_SYMBOL_GPL(cio_disable_subchannel);
474 
475 int cio_create_sch_lock(struct subchannel *sch)
476 {
477 	sch->lock = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
478 	if (!sch->lock)
479 		return -ENOMEM;
480 	spin_lock_init(sch->lock);
481 	return 0;
482 }
483 
484 static int cio_check_devno_blacklisted(struct subchannel *sch)
485 {
486 	if (is_blacklisted(sch->schid.ssid, sch->schib.pmcw.dev)) {
487 		/*
488 		 * This device must not be known to Linux. So we simply
489 		 * say that there is no device and return ENODEV.
490 		 */
491 		CIO_MSG_EVENT(6, "Blacklisted device detected "
492 			      "at devno %04X, subchannel set %x\n",
493 			      sch->schib.pmcw.dev, sch->schid.ssid);
494 		return -ENODEV;
495 	}
496 	return 0;
497 }
498 
499 static int cio_validate_io_subchannel(struct subchannel *sch)
500 {
501 	/* Initialization for io subchannels. */
502 	if (!css_sch_is_valid(&sch->schib))
503 		return -ENODEV;
504 
505 	/* Devno is valid. */
506 	return cio_check_devno_blacklisted(sch);
507 }
508 
509 static int cio_validate_msg_subchannel(struct subchannel *sch)
510 {
511 	/* Initialization for message subchannels. */
512 	if (!css_sch_is_valid(&sch->schib))
513 		return -ENODEV;
514 
515 	/* Devno is valid. */
516 	return cio_check_devno_blacklisted(sch);
517 }
518 
519 /**
520  * cio_validate_subchannel - basic validation of subchannel
521  * @sch: subchannel structure to be filled out
522  * @schid: subchannel id
523  *
524  * Find out subchannel type and initialize struct subchannel.
525  * Return codes:
526  *   0 on success
527  *   -ENXIO for non-defined subchannels
528  *   -ENODEV for invalid subchannels or blacklisted devices
529  *   -EIO for subchannels in an invalid subchannel set
530  */
531 int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
532 {
533 	char dbf_txt[15];
534 	int ccode;
535 	int err;
536 
537 	sprintf(dbf_txt, "valsch%x", schid.sch_no);
538 	CIO_TRACE_EVENT(4, dbf_txt);
539 
540 	/* Nuke all fields. */
541 	memset(sch, 0, sizeof(struct subchannel));
542 
543 	sch->schid = schid;
544 	if (cio_is_console(schid)) {
545 		sch->lock = cio_get_console_lock();
546 	} else {
547 		err = cio_create_sch_lock(sch);
548 		if (err)
549 			goto out;
550 	}
551 	mutex_init(&sch->reg_mutex);
552 
553 	/*
554 	 * The first subchannel that is not-operational (ccode==3)
555 	 *  indicates that there aren't any more devices available.
556 	 * If stsch gets an exception, it means the current subchannel set
557 	 *  is not valid.
558 	 */
559 	ccode = stsch_err (schid, &sch->schib);
560 	if (ccode) {
561 		err = (ccode == 3) ? -ENXIO : ccode;
562 		goto out;
563 	}
564 	/* Copy subchannel type from path management control word. */
565 	sch->st = sch->schib.pmcw.st;
566 
567 	switch (sch->st) {
568 	case SUBCHANNEL_TYPE_IO:
569 		err = cio_validate_io_subchannel(sch);
570 		break;
571 	case SUBCHANNEL_TYPE_MSG:
572 		err = cio_validate_msg_subchannel(sch);
573 		break;
574 	default:
575 		err = 0;
576 	}
577 	if (err)
578 		goto out;
579 
580 	CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
581 		      sch->schid.ssid, sch->schid.sch_no, sch->st);
582 	return 0;
583 out:
584 	if (!cio_is_console(schid))
585 		kfree(sch->lock);
586 	sch->lock = NULL;
587 	return err;
588 }
589 
590 /*
591  * do_IRQ() handles all normal I/O device IRQ's (the special
592  *	    SMP cross-CPU interrupts have their own specific
593  *	    handlers).
594  *
595  */
596 void __irq_entry do_IRQ(struct pt_regs *regs)
597 {
598 	struct tpi_info *tpi_info;
599 	struct subchannel *sch;
600 	struct irb *irb;
601 	struct pt_regs *old_regs;
602 
603 	old_regs = set_irq_regs(regs);
604 	s390_idle_check(regs, S390_lowcore.int_clock,
605 			S390_lowcore.async_enter_timer);
606 	irq_enter();
607 	__this_cpu_write(s390_idle.nohz_delay, 1);
608 	if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
609 		/* Serve timer interrupts first. */
610 		clock_comparator_work();
611 	/*
612 	 * Get interrupt information from lowcore
613 	 */
614 	tpi_info = (struct tpi_info *)&S390_lowcore.subchannel_id;
615 	irb = (struct irb *)&S390_lowcore.irb;
616 	do {
617 		kstat_cpu(smp_processor_id()).irqs[IO_INTERRUPT]++;
618 		if (tpi_info->adapter_IO) {
619 			do_adapter_IO(tpi_info->isc);
620 			continue;
621 		}
622 		sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
623 		if (!sch) {
624 			/* Clear pending interrupt condition. */
625 			kstat_cpu(smp_processor_id()).irqs[IOINT_CIO]++;
626 			tsch(tpi_info->schid, irb);
627 			continue;
628 		}
629 		spin_lock(sch->lock);
630 		/* Store interrupt response block to lowcore. */
631 		if (tsch(tpi_info->schid, irb) == 0) {
632 			/* Keep subchannel information word up to date. */
633 			memcpy (&sch->schib.scsw, &irb->scsw,
634 				sizeof (irb->scsw));
635 			/* Call interrupt handler if there is one. */
636 			if (sch->driver && sch->driver->irq)
637 				sch->driver->irq(sch);
638 			else
639 				kstat_cpu(smp_processor_id()).irqs[IOINT_CIO]++;
640 		} else
641 			kstat_cpu(smp_processor_id()).irqs[IOINT_CIO]++;
642 		spin_unlock(sch->lock);
643 		/*
644 		 * Are more interrupts pending?
645 		 * If so, the tpi instruction will update the lowcore
646 		 * to hold the info for the next interrupt.
647 		 * We don't do this for VM because a tpi drops the cpu
648 		 * out of the sie which costs more cycles than it saves.
649 		 */
650 	} while (MACHINE_IS_LPAR && tpi(NULL) != 0);
651 	irq_exit();
652 	set_irq_regs(old_regs);
653 }
654 
655 #ifdef CONFIG_CCW_CONSOLE
656 static struct subchannel console_subchannel;
657 static struct io_subchannel_private console_priv;
658 static int console_subchannel_in_use;
659 
660 /*
661  * Use cio_tpi to get a pending interrupt and call the interrupt handler.
662  * Return non-zero if an interrupt was processed, zero otherwise.
663  */
664 static int cio_tpi(void)
665 {
666 	struct tpi_info *tpi_info;
667 	struct subchannel *sch;
668 	struct irb *irb;
669 	int irq_context;
670 
671 	tpi_info = (struct tpi_info *)&S390_lowcore.subchannel_id;
672 	if (tpi(NULL) != 1)
673 		return 0;
674 	kstat_cpu(smp_processor_id()).irqs[IO_INTERRUPT]++;
675 	if (tpi_info->adapter_IO) {
676 		do_adapter_IO(tpi_info->isc);
677 		return 1;
678 	}
679 	irb = (struct irb *)&S390_lowcore.irb;
680 	/* Store interrupt response block to lowcore. */
681 	if (tsch(tpi_info->schid, irb) != 0) {
682 		/* Not status pending or not operational. */
683 		kstat_cpu(smp_processor_id()).irqs[IOINT_CIO]++;
684 		return 1;
685 	}
686 	sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
687 	if (!sch) {
688 		kstat_cpu(smp_processor_id()).irqs[IOINT_CIO]++;
689 		return 1;
690 	}
691 	irq_context = in_interrupt();
692 	if (!irq_context)
693 		local_bh_disable();
694 	irq_enter();
695 	spin_lock(sch->lock);
696 	memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
697 	if (sch->driver && sch->driver->irq)
698 		sch->driver->irq(sch);
699 	else
700 		kstat_cpu(smp_processor_id()).irqs[IOINT_CIO]++;
701 	spin_unlock(sch->lock);
702 	irq_exit();
703 	if (!irq_context)
704 		_local_bh_enable();
705 	return 1;
706 }
707 
708 void *cio_get_console_priv(void)
709 {
710 	return &console_priv;
711 }
712 
713 /*
714  * busy wait for the next interrupt on the console
715  */
716 void wait_cons_dev(void)
717 	__releases(console_subchannel.lock)
718 	__acquires(console_subchannel.lock)
719 {
720 	unsigned long cr6      __attribute__ ((aligned (8)));
721 	unsigned long save_cr6 __attribute__ ((aligned (8)));
722 
723 	/*
724 	 * before entering the spinlock we may already have
725 	 * processed the interrupt on a different CPU...
726 	 */
727 	if (!console_subchannel_in_use)
728 		return;
729 
730 	/* disable all but the console isc */
731 	__ctl_store (save_cr6, 6, 6);
732 	cr6 = 1UL << (31 - CONSOLE_ISC);
733 	__ctl_load (cr6, 6, 6);
734 
735 	do {
736 		spin_unlock(console_subchannel.lock);
737 		if (!cio_tpi())
738 			cpu_relax();
739 		spin_lock(console_subchannel.lock);
740 	} while (console_subchannel.schib.scsw.cmd.actl != 0);
741 	/*
742 	 * restore previous isc value
743 	 */
744 	__ctl_load (save_cr6, 6, 6);
745 }
746 
747 static int
748 cio_test_for_console(struct subchannel_id schid, void *data)
749 {
750 	if (stsch_err(schid, &console_subchannel.schib) != 0)
751 		return -ENXIO;
752 	if ((console_subchannel.schib.pmcw.st == SUBCHANNEL_TYPE_IO) &&
753 	    console_subchannel.schib.pmcw.dnv &&
754 	    (console_subchannel.schib.pmcw.dev == console_devno)) {
755 		console_irq = schid.sch_no;
756 		return 1; /* found */
757 	}
758 	return 0;
759 }
760 
761 
762 static int
763 cio_get_console_sch_no(void)
764 {
765 	struct subchannel_id schid;
766 
767 	init_subchannel_id(&schid);
768 	if (console_irq != -1) {
769 		/* VM provided us with the irq number of the console. */
770 		schid.sch_no = console_irq;
771 		if (stsch_err(schid, &console_subchannel.schib) != 0 ||
772 		    (console_subchannel.schib.pmcw.st != SUBCHANNEL_TYPE_IO) ||
773 		    !console_subchannel.schib.pmcw.dnv)
774 			return -1;
775 		console_devno = console_subchannel.schib.pmcw.dev;
776 	} else if (console_devno != -1) {
777 		/* At least the console device number is known. */
778 		for_each_subchannel(cio_test_for_console, NULL);
779 		if (console_irq == -1)
780 			return -1;
781 	} else {
782 		/* unlike in 2.4, we cannot autoprobe here, since
783 		 * the channel subsystem is not fully initialized.
784 		 * With some luck, the HWC console can take over */
785 		return -1;
786 	}
787 	return console_irq;
788 }
789 
790 struct subchannel *
791 cio_probe_console(void)
792 {
793 	int sch_no, ret;
794 	struct subchannel_id schid;
795 
796 	if (xchg(&console_subchannel_in_use, 1) != 0)
797 		return ERR_PTR(-EBUSY);
798 	sch_no = cio_get_console_sch_no();
799 	if (sch_no == -1) {
800 		console_subchannel_in_use = 0;
801 		pr_warning("No CCW console was found\n");
802 		return ERR_PTR(-ENODEV);
803 	}
804 	memset(&console_subchannel, 0, sizeof(struct subchannel));
805 	init_subchannel_id(&schid);
806 	schid.sch_no = sch_no;
807 	ret = cio_validate_subchannel(&console_subchannel, schid);
808 	if (ret) {
809 		console_subchannel_in_use = 0;
810 		return ERR_PTR(-ENODEV);
811 	}
812 
813 	/*
814 	 * enable console I/O-interrupt subclass
815 	 */
816 	isc_register(CONSOLE_ISC);
817 	console_subchannel.config.isc = CONSOLE_ISC;
818 	console_subchannel.config.intparm = (u32)(addr_t)&console_subchannel;
819 	ret = cio_commit_config(&console_subchannel);
820 	if (ret) {
821 		isc_unregister(CONSOLE_ISC);
822 		console_subchannel_in_use = 0;
823 		return ERR_PTR(ret);
824 	}
825 	return &console_subchannel;
826 }
827 
828 void
829 cio_release_console(void)
830 {
831 	console_subchannel.config.intparm = 0;
832 	cio_commit_config(&console_subchannel);
833 	isc_unregister(CONSOLE_ISC);
834 	console_subchannel_in_use = 0;
835 }
836 
837 /* Bah... hack to catch console special sausages. */
838 int
839 cio_is_console(struct subchannel_id schid)
840 {
841 	if (!console_subchannel_in_use)
842 		return 0;
843 	return schid_equal(&schid, &console_subchannel.schid);
844 }
845 
846 struct subchannel *
847 cio_get_console_subchannel(void)
848 {
849 	if (!console_subchannel_in_use)
850 		return NULL;
851 	return &console_subchannel;
852 }
853 
854 #endif
855 static int
856 __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
857 {
858 	int retry, cc;
859 
860 	cc = 0;
861 	for (retry=0;retry<3;retry++) {
862 		schib->pmcw.ena = 0;
863 		cc = msch_err(schid, schib);
864 		if (cc)
865 			return (cc==3?-ENODEV:-EBUSY);
866 		if (stsch_err(schid, schib) || !css_sch_is_valid(schib))
867 			return -ENODEV;
868 		if (!schib->pmcw.ena)
869 			return 0;
870 	}
871 	return -EBUSY; /* uhm... */
872 }
873 
874 static int
875 __clear_io_subchannel_easy(struct subchannel_id schid)
876 {
877 	int retry;
878 
879 	if (csch(schid))
880 		return -ENODEV;
881 	for (retry=0;retry<20;retry++) {
882 		struct tpi_info ti;
883 
884 		if (tpi(&ti)) {
885 			tsch(ti.schid, (struct irb *)&S390_lowcore.irb);
886 			if (schid_equal(&ti.schid, &schid))
887 				return 0;
888 		}
889 		udelay_simple(100);
890 	}
891 	return -EBUSY;
892 }
893 
894 static void __clear_chsc_subchannel_easy(void)
895 {
896 	/* It seems we can only wait for a bit here :/ */
897 	udelay_simple(100);
898 }
899 
900 static int pgm_check_occured;
901 
902 static void cio_reset_pgm_check_handler(void)
903 {
904 	pgm_check_occured = 1;
905 }
906 
907 static int stsch_reset(struct subchannel_id schid, struct schib *addr)
908 {
909 	int rc;
910 
911 	pgm_check_occured = 0;
912 	s390_base_pgm_handler_fn = cio_reset_pgm_check_handler;
913 	rc = stsch_err(schid, addr);
914 	s390_base_pgm_handler_fn = NULL;
915 
916 	/* The program check handler could have changed pgm_check_occured. */
917 	barrier();
918 
919 	if (pgm_check_occured)
920 		return -EIO;
921 	else
922 		return rc;
923 }
924 
925 static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
926 {
927 	struct schib schib;
928 
929 	if (stsch_reset(schid, &schib))
930 		return -ENXIO;
931 	if (!schib.pmcw.ena)
932 		return 0;
933 	switch(__disable_subchannel_easy(schid, &schib)) {
934 	case 0:
935 	case -ENODEV:
936 		break;
937 	default: /* -EBUSY */
938 		switch (schib.pmcw.st) {
939 		case SUBCHANNEL_TYPE_IO:
940 			if (__clear_io_subchannel_easy(schid))
941 				goto out; /* give up... */
942 			break;
943 		case SUBCHANNEL_TYPE_CHSC:
944 			__clear_chsc_subchannel_easy();
945 			break;
946 		default:
947 			/* No default clear strategy */
948 			break;
949 		}
950 		stsch_err(schid, &schib);
951 		__disable_subchannel_easy(schid, &schib);
952 	}
953 out:
954 	return 0;
955 }
956 
957 static atomic_t chpid_reset_count;
958 
959 static void s390_reset_chpids_mcck_handler(void)
960 {
961 	struct crw crw;
962 	struct mci *mci;
963 
964 	/* Check for pending channel report word. */
965 	mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
966 	if (!mci->cp)
967 		return;
968 	/* Process channel report words. */
969 	while (stcrw(&crw) == 0) {
970 		/* Check for responses to RCHP. */
971 		if (crw.slct && crw.rsc == CRW_RSC_CPATH)
972 			atomic_dec(&chpid_reset_count);
973 	}
974 }
975 
976 #define RCHP_TIMEOUT (30 * USEC_PER_SEC)
977 static void css_reset(void)
978 {
979 	int i, ret;
980 	unsigned long long timeout;
981 	struct chp_id chpid;
982 
983 	/* Reset subchannels. */
984 	for_each_subchannel(__shutdown_subchannel_easy,  NULL);
985 	/* Reset channel paths. */
986 	s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler;
987 	/* Enable channel report machine checks. */
988 	__ctl_set_bit(14, 28);
989 	/* Temporarily reenable machine checks. */
990 	local_mcck_enable();
991 	chp_id_init(&chpid);
992 	for (i = 0; i <= __MAX_CHPID; i++) {
993 		chpid.id = i;
994 		ret = rchp(chpid);
995 		if ((ret == 0) || (ret == 2))
996 			/*
997 			 * rchp either succeeded, or another rchp is already
998 			 * in progress. In either case, we'll get a crw.
999 			 */
1000 			atomic_inc(&chpid_reset_count);
1001 	}
1002 	/* Wait for machine check for all channel paths. */
1003 	timeout = get_clock() + (RCHP_TIMEOUT << 12);
1004 	while (atomic_read(&chpid_reset_count) != 0) {
1005 		if (get_clock() > timeout)
1006 			break;
1007 		cpu_relax();
1008 	}
1009 	/* Disable machine checks again. */
1010 	local_mcck_disable();
1011 	/* Disable channel report machine checks. */
1012 	__ctl_clear_bit(14, 28);
1013 	s390_base_mcck_handler_fn = NULL;
1014 }
1015 
1016 static struct reset_call css_reset_call = {
1017 	.fn = css_reset,
1018 };
1019 
1020 static int __init init_css_reset_call(void)
1021 {
1022 	atomic_set(&chpid_reset_count, 0);
1023 	register_reset_call(&css_reset_call);
1024 	return 0;
1025 }
1026 
1027 arch_initcall(init_css_reset_call);
1028 
1029 struct sch_match_id {
1030 	struct subchannel_id schid;
1031 	struct ccw_dev_id devid;
1032 	int rc;
1033 };
1034 
1035 static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
1036 {
1037 	struct schib schib;
1038 	struct sch_match_id *match_id = data;
1039 
1040 	if (stsch_reset(schid, &schib))
1041 		return -ENXIO;
1042 	if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
1043 	    (schib.pmcw.dev == match_id->devid.devno) &&
1044 	    (schid.ssid == match_id->devid.ssid)) {
1045 		match_id->schid = schid;
1046 		match_id->rc = 0;
1047 		return 1;
1048 	}
1049 	return 0;
1050 }
1051 
1052 static int reipl_find_schid(struct ccw_dev_id *devid,
1053 			    struct subchannel_id *schid)
1054 {
1055 	struct sch_match_id match_id;
1056 
1057 	match_id.devid = *devid;
1058 	match_id.rc = -ENODEV;
1059 	for_each_subchannel(__reipl_subchannel_match, &match_id);
1060 	if (match_id.rc == 0)
1061 		*schid = match_id.schid;
1062 	return match_id.rc;
1063 }
1064 
1065 extern void do_reipl_asm(__u32 schid);
1066 
1067 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
1068 void reipl_ccw_dev(struct ccw_dev_id *devid)
1069 {
1070 	struct subchannel_id schid;
1071 
1072 	s390_reset_system(NULL, NULL);
1073 	if (reipl_find_schid(devid, &schid) != 0)
1074 		panic("IPL Device not found\n");
1075 	do_reipl_asm(*((__u32*)&schid));
1076 }
1077 
1078 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
1079 {
1080 	struct subchannel_id schid;
1081 	struct schib schib;
1082 
1083 	schid = *(struct subchannel_id *)&S390_lowcore.subchannel_id;
1084 	if (!schid.one)
1085 		return -ENODEV;
1086 	if (stsch_err(schid, &schib))
1087 		return -ENODEV;
1088 	if (schib.pmcw.st != SUBCHANNEL_TYPE_IO)
1089 		return -ENODEV;
1090 	if (!schib.pmcw.dnv)
1091 		return -ENODEV;
1092 	iplinfo->devno = schib.pmcw.dev;
1093 	iplinfo->is_qdio = schib.pmcw.qf;
1094 	return 0;
1095 }
1096 
1097 /**
1098  * cio_tm_start_key - perform start function
1099  * @sch: subchannel on which to perform the start function
1100  * @tcw: transport-command word to be started
1101  * @lpm: mask of paths to use
1102  * @key: storage key to use for storage access
1103  *
1104  * Start the tcw on the given subchannel. Return zero on success, non-zero
1105  * otherwise.
1106  */
1107 int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
1108 {
1109 	int cc;
1110 	union orb *orb = &to_io_private(sch)->orb;
1111 
1112 	memset(orb, 0, sizeof(union orb));
1113 	orb->tm.intparm = (u32) (addr_t) sch;
1114 	orb->tm.key = key >> 4;
1115 	orb->tm.b = 1;
1116 	orb->tm.lpm = lpm ? lpm : sch->lpm;
1117 	orb->tm.tcw = (u32) (addr_t) tcw;
1118 	cc = ssch(sch->schid, orb);
1119 	switch (cc) {
1120 	case 0:
1121 		return 0;
1122 	case 1:
1123 	case 2:
1124 		return -EBUSY;
1125 	default:
1126 		return cio_start_handle_notoper(sch, lpm);
1127 	}
1128 }
1129 
1130 /**
1131  * cio_tm_intrg - perform interrogate function
1132  * @sch - subchannel on which to perform the interrogate function
1133  *
1134  * If the specified subchannel is running in transport-mode, perform the
1135  * interrogate function. Return zero on success, non-zero otherwie.
1136  */
1137 int cio_tm_intrg(struct subchannel *sch)
1138 {
1139 	int cc;
1140 
1141 	if (!to_io_private(sch)->orb.tm.b)
1142 		return -EINVAL;
1143 	cc = xsch(sch->schid);
1144 	switch (cc) {
1145 	case 0:
1146 	case 2:
1147 		return 0;
1148 	case 1:
1149 		return -EBUSY;
1150 	default:
1151 		return -ENODEV;
1152 	}
1153 }
1154