cio.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  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 pr_fmt(fmt) "cio: " fmt
 13
 14#include <linux/export.h>
 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 <linux/irq.h>
 23#include <asm/cio.h>
 24#include <asm/delay.h>
 25#include <asm/irq.h>
 26#include <asm/irq_regs.h>
 27#include <asm/setup.h>
 28#include <asm/ipl.h>
 29#include <asm/chpid.h>
 30#include <asm/airq.h>
 31#include <asm/isc.h>
 32#include <linux/sched/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#include "trace.h"
 45
 46debug_info_t *cio_debug_msg_id;
 47debug_info_t *cio_debug_trace_id;
 48debug_info_t *cio_debug_crw_id;
 49
 50DEFINE_PER_CPU_ALIGNED(struct irb, cio_irb);
 51EXPORT_PER_CPU_SYMBOL(cio_irb);
 52
 53/*
 54 * Function: cio_debug_init
 55 * Initializes three debug logs for common I/O:
 56 * - cio_msg logs generic cio messages
 57 * - cio_trace logs the calling of different functions
 58 * - cio_crw logs machine check related cio messages
 59 */
 60static int __init cio_debug_init(void)
 61{
 62	cio_debug_msg_id = debug_register("cio_msg", 16, 1, 11 * sizeof(long));
 63	if (!cio_debug_msg_id)
 64		goto out_unregister;
 65	debug_register_view(cio_debug_msg_id, &debug_sprintf_view);
 66	debug_set_level(cio_debug_msg_id, 2);
 67	cio_debug_trace_id = debug_register("cio_trace", 16, 1, 16);
 68	if (!cio_debug_trace_id)
 69		goto out_unregister;
 70	debug_register_view(cio_debug_trace_id, &debug_hex_ascii_view);
 71	debug_set_level(cio_debug_trace_id, 2);
 72	cio_debug_crw_id = debug_register("cio_crw", 8, 1, 8 * sizeof(long));
 73	if (!cio_debug_crw_id)
 74		goto out_unregister;
 75	debug_register_view(cio_debug_crw_id, &debug_sprintf_view);
 76	debug_set_level(cio_debug_crw_id, 4);
 77	return 0;
 78
 79out_unregister:
 80	debug_unregister(cio_debug_msg_id);
 81	debug_unregister(cio_debug_trace_id);
 82	debug_unregister(cio_debug_crw_id);
 83	return -1;
 84}
 85
 86arch_initcall (cio_debug_init);
 87
 88int cio_set_options(struct subchannel *sch, int flags)
 89{
 90	struct io_subchannel_private *priv = to_io_private(sch);
 91
 92	priv->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
 93	priv->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
 94	priv->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
 95	return 0;
 96}
 97
 98static int
 99cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
100{
101	char dbf_text[15];
102
103	if (lpm != 0)
104		sch->lpm &= ~lpm;
105	else
106		sch->lpm = 0;
107
108	CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
109		      "subchannel 0.%x.%04x!\n", sch->schid.ssid,
110		      sch->schid.sch_no);
111
112	if (cio_update_schib(sch))
113		return -ENODEV;
114
115	scnprintf(dbf_text, sizeof(dbf_text), "no%s", dev_name(&sch->dev));
116	CIO_TRACE_EVENT(0, dbf_text);
117	CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
118
119	return (sch->lpm ? -EACCES : -ENODEV);
120}
121
122int
123cio_start_key (struct subchannel *sch,	/* subchannel structure */
124	       struct ccw1 * cpa,	/* logical channel prog addr */
125	       __u8 lpm,		/* logical path mask */
126	       __u8 key)                /* storage key */
127{
128	struct io_subchannel_private *priv = to_io_private(sch);
129	union orb *orb = &priv->orb;
130	int ccode;
131
132	CIO_TRACE_EVENT(5, "stIO");
133	CIO_TRACE_EVENT(5, dev_name(&sch->dev));
134
135	memset(orb, 0, sizeof(union orb));
136	/* sch is always under 2G. */
137	orb->cmd.intparm = (u32)virt_to_phys(sch);
138	orb->cmd.fmt = 1;
139
140	orb->cmd.pfch = priv->options.prefetch == 0;
141	orb->cmd.spnd = priv->options.suspend;
142	orb->cmd.ssic = priv->options.suspend && priv->options.inter;
143	orb->cmd.lpm = (lpm != 0) ? lpm : sch->lpm;
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	orb->cmd.key = key >> 4;
150	/* issue "Start Subchannel" */
151	orb->cmd.cpa = virt_to_dma32(cpa);
152	ccode = ssch(sch->schid, orb);
153
154	/* process condition code */
155	CIO_HEX_EVENT(5, &ccode, sizeof(ccode));
156
157	switch (ccode) {
158	case 0:
159		/*
160		 * initialize device status information
161		 */
162		sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
163		return 0;
164	case 1:		/* status pending */
165	case 2:		/* busy */
166		return -EBUSY;
167	case 3:		/* device/path not operational */
168		return cio_start_handle_notoper(sch, lpm);
169	default:
170		return ccode;
171	}
172}
173EXPORT_SYMBOL_GPL(cio_start_key);
174
175int
176cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
177{
178	return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
179}
180EXPORT_SYMBOL_GPL(cio_start);
181
182/*
183 * resume suspended I/O operation
184 */
185int
186cio_resume (struct subchannel *sch)
187{
188	int ccode;
189
190	CIO_TRACE_EVENT(4, "resIO");
191	CIO_TRACE_EVENT(4, dev_name(&sch->dev));
192
193	ccode = rsch (sch->schid);
194
195	CIO_HEX_EVENT(4, &ccode, sizeof(ccode));
196
197	switch (ccode) {
198	case 0:
199		sch->schib.scsw.cmd.actl |= SCSW_ACTL_RESUME_PEND;
200		return 0;
201	case 1:
202		return -EBUSY;
203	case 2:
204		return -EINVAL;
205	default:
206		/*
207		 * useless to wait for request completion
208		 *  as device is no longer operational !
209		 */
210		return -ENODEV;
211	}
212}
213EXPORT_SYMBOL_GPL(cio_resume);
214
215/*
216 * halt I/O operation
217 */
218int
219cio_halt(struct subchannel *sch)
220{
221	int ccode;
222
223	if (!sch)
224		return -ENODEV;
225
226	CIO_TRACE_EVENT(2, "haltIO");
227	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
228
229	/*
230	 * Issue "Halt subchannel" and process condition code
231	 */
232	ccode = hsch (sch->schid);
233
234	CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
235
236	switch (ccode) {
237	case 0:
238		sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND;
239		return 0;
240	case 1:		/* status pending */
241	case 2:		/* busy */
242		return -EBUSY;
243	default:		/* device not operational */
244		return -ENODEV;
245	}
246}
247EXPORT_SYMBOL_GPL(cio_halt);
248
249/*
250 * Clear I/O operation
251 */
252int
253cio_clear(struct subchannel *sch)
254{
255	int ccode;
256
257	if (!sch)
258		return -ENODEV;
259
260	CIO_TRACE_EVENT(2, "clearIO");
261	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
262
263	/*
264	 * Issue "Clear subchannel" and process condition code
265	 */
266	ccode = csch (sch->schid);
267
268	CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
269
270	switch (ccode) {
271	case 0:
272		sch->schib.scsw.cmd.actl |= SCSW_ACTL_CLEAR_PEND;
273		return 0;
274	default:		/* device not operational */
275		return -ENODEV;
276	}
277}
278EXPORT_SYMBOL_GPL(cio_clear);
279
280/*
281 * Function: cio_cancel
282 * Issues a "Cancel Subchannel" on the specified subchannel
283 * Note: We don't need any fancy intparms and flags here
284 *	 since xsch is executed synchronously.
285 * Only for common I/O internal use as for now.
286 */
287int
288cio_cancel (struct subchannel *sch)
289{
290	int ccode;
291
292	if (!sch)
293		return -ENODEV;
294
295	CIO_TRACE_EVENT(2, "cancelIO");
296	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
297
298	ccode = xsch (sch->schid);
299
300	CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
301
302	switch (ccode) {
303	case 0:		/* success */
304		/* Update information in scsw. */
305		if (cio_update_schib(sch))
306			return -ENODEV;
307		return 0;
308	case 1:		/* status pending */
309		return -EBUSY;
310	case 2:		/* not applicable */
311		return -EINVAL;
312	default:	/* not oper */
313		return -ENODEV;
314	}
315}
316EXPORT_SYMBOL_GPL(cio_cancel);
317
318/**
319 * cio_cancel_halt_clear - Cancel running I/O by performing cancel, halt
320 * and clear ordinally if subchannel is valid.
321 * @sch: subchannel on which to perform the cancel_halt_clear operation
322 * @iretry: the number of the times remained to retry the next operation
323 *
324 * This should be called repeatedly since halt/clear are asynchronous
325 * operations. We do one try with cio_cancel, three tries with cio_halt,
326 * 255 tries with cio_clear. The caller should initialize @iretry with
327 * the value 255 for its first call to this, and keep using the same
328 * @iretry in the subsequent calls until it gets a non -EBUSY return.
329 *
330 * Returns 0 if device now idle, -ENODEV for device not operational,
331 * -EBUSY if an interrupt is expected (either from halt/clear or from a
332 * status pending), and -EIO if out of retries.
333 */
334int cio_cancel_halt_clear(struct subchannel *sch, int *iretry)
335{
336	int ret;
337
338	if (cio_update_schib(sch))
339		return -ENODEV;
340	if (!sch->schib.pmcw.ena)
341		/* Not operational -> done. */
342		return 0;
343	/* Stage 1: cancel io. */
344	if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_HALT_PEND) &&
345	    !(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
346		if (!scsw_is_tm(&sch->schib.scsw)) {
347			ret = cio_cancel(sch);
348			if (ret != -EINVAL)
349				return ret;
350		}
351		/*
352		 * Cancel io unsuccessful or not applicable (transport mode).
353		 * Continue with asynchronous instructions.
354		 */
355		*iretry = 3;	/* 3 halt retries. */
356	}
357	/* Stage 2: halt io. */
358	if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
359		if (*iretry) {
360			*iretry -= 1;
361			ret = cio_halt(sch);
362			if (ret != -EBUSY)
363				return (ret == 0) ? -EBUSY : ret;
364		}
365		/* Halt io unsuccessful. */
366		*iretry = 255;	/* 255 clear retries. */
367	}
368	/* Stage 3: clear io. */
369	if (*iretry) {
370		*iretry -= 1;
371		ret = cio_clear(sch);
372		return (ret == 0) ? -EBUSY : ret;
373	}
374	/* Function was unsuccessful */
375	return -EIO;
376}
377EXPORT_SYMBOL_GPL(cio_cancel_halt_clear);
378
379static void cio_apply_config(struct subchannel *sch, struct schib *schib)
380{
381	schib->pmcw.intparm = sch->config.intparm;
382	schib->pmcw.mbi = sch->config.mbi;
383	schib->pmcw.isc = sch->config.isc;
384	schib->pmcw.ena = sch->config.ena;
385	schib->pmcw.mme = sch->config.mme;
386	schib->pmcw.mp = sch->config.mp;
387	schib->pmcw.csense = sch->config.csense;
388	schib->pmcw.mbfc = sch->config.mbfc;
389	if (sch->config.mbfc)
390		schib->mba = sch->config.mba;
391}
392
393static int cio_check_config(struct subchannel *sch, struct schib *schib)
394{
395	return (schib->pmcw.intparm == sch->config.intparm) &&
396		(schib->pmcw.mbi == sch->config.mbi) &&
397		(schib->pmcw.isc == sch->config.isc) &&
398		(schib->pmcw.ena == sch->config.ena) &&
399		(schib->pmcw.mme == sch->config.mme) &&
400		(schib->pmcw.mp == sch->config.mp) &&
401		(schib->pmcw.csense == sch->config.csense) &&
402		(schib->pmcw.mbfc == sch->config.mbfc) &&
403		(!sch->config.mbfc || (schib->mba == sch->config.mba));
404}
405
406/*
407 * cio_commit_config - apply configuration to the subchannel
408 */
409int cio_commit_config(struct subchannel *sch)
410{
411	int ccode, retry, ret = 0;
412	struct schib schib;
413	struct irb irb;
414
415	if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
416		return -ENODEV;
417
418	for (retry = 0; retry < 5; retry++) {
419		/* copy desired changes to local schib */
420		cio_apply_config(sch, &schib);
421		ccode = msch(sch->schid, &schib);
422		if (ccode < 0) /* -EIO if msch gets a program check. */
423			return ccode;
424		switch (ccode) {
425		case 0: /* successful */
426			if (stsch(sch->schid, &schib) ||
427			    !css_sch_is_valid(&schib))
428				return -ENODEV;
429			if (cio_check_config(sch, &schib)) {
430				/* commit changes from local schib */
431				memcpy(&sch->schib, &schib, sizeof(schib));
432				return 0;
433			}
434			ret = -EAGAIN;
435			break;
436		case 1: /* status pending */
437			ret = -EBUSY;
438			if (tsch(sch->schid, &irb))
439				return ret;
440			break;
441		case 2: /* busy */
442			udelay(100); /* allow for recovery */
443			ret = -EBUSY;
444			break;
445		case 3: /* not operational */
446			return -ENODEV;
447		}
448	}
449	return ret;
450}
451EXPORT_SYMBOL_GPL(cio_commit_config);
452
453/**
454 * cio_update_schib - Perform stsch and update schib if subchannel is valid.
455 * @sch: subchannel on which to perform stsch
456 * Return zero on success, -ENODEV otherwise.
457 */
458int cio_update_schib(struct subchannel *sch)
459{
460	struct schib schib;
461
462	if (stsch(sch->schid, &schib))
463		return -ENODEV;
464
465	memcpy(&sch->schib, &schib, sizeof(schib));
466
467	if (!css_sch_is_valid(&schib))
468		return -EACCES;
469
470	return 0;
471}
472EXPORT_SYMBOL_GPL(cio_update_schib);
473
474/**
475 * cio_enable_subchannel - enable a subchannel.
476 * @sch: subchannel to be enabled
477 * @intparm: interruption parameter to set
478 */
479int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
480{
481	int ret;
482
483	CIO_TRACE_EVENT(2, "ensch");
484	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
485
486	if (sch_is_pseudo_sch(sch))
487		return -EINVAL;
488	if (cio_update_schib(sch))
489		return -ENODEV;
490
491	sch->config.ena = 1;
492	sch->config.isc = sch->isc;
493	sch->config.intparm = intparm;
494
495	ret = cio_commit_config(sch);
496	if (ret == -EIO) {
497		/*
498		 * Got a program check in msch. Try without
499		 * the concurrent sense bit the next time.
500		 */
501		sch->config.csense = 0;
502		ret = cio_commit_config(sch);
503	}
504	CIO_HEX_EVENT(2, &ret, sizeof(ret));
505	return ret;
506}
507EXPORT_SYMBOL_GPL(cio_enable_subchannel);
508
509/**
510 * cio_disable_subchannel - disable a subchannel.
511 * @sch: subchannel to disable
512 */
513int cio_disable_subchannel(struct subchannel *sch)
514{
515	int ret;
516
517	CIO_TRACE_EVENT(2, "dissch");
518	CIO_TRACE_EVENT(2, dev_name(&sch->dev));
519
520	if (sch_is_pseudo_sch(sch))
521		return 0;
522	if (cio_update_schib(sch))
523		return -ENODEV;
524
525	sch->config.ena = 0;
526	ret = cio_commit_config(sch);
527
528	CIO_HEX_EVENT(2, &ret, sizeof(ret));
529	return ret;
530}
531EXPORT_SYMBOL_GPL(cio_disable_subchannel);
532
533/*
534 * do_cio_interrupt() handles all normal I/O device IRQ's
535 */
536static irqreturn_t do_cio_interrupt(int irq, void *dummy)
537{
538	struct tpi_info *tpi_info;
539	struct subchannel *sch;
540	struct irb *irb;
541
542	tpi_info = &get_irq_regs()->tpi_info;
543	trace_s390_cio_interrupt(tpi_info);
544	irb = this_cpu_ptr(&cio_irb);
545	if (!tpi_info->intparm) {
546		/* Clear pending interrupt condition. */
547		inc_irq_stat(IRQIO_CIO);
548		tsch(tpi_info->schid, irb);
549		return IRQ_HANDLED;
550	}
551	sch = phys_to_virt(tpi_info->intparm);
552	spin_lock(&sch->lock);
553	/* Store interrupt response block to lowcore. */
554	if (tsch(tpi_info->schid, irb) == 0) {
555		/* Keep subchannel information word up to date. */
556		memcpy (&sch->schib.scsw, &irb->scsw, sizeof (irb->scsw));
557		/* Call interrupt handler if there is one. */
558		if (sch->driver && sch->driver->irq)
559			sch->driver->irq(sch);
560		else
561			inc_irq_stat(IRQIO_CIO);
562	} else
563		inc_irq_stat(IRQIO_CIO);
564	spin_unlock(&sch->lock);
565
566	return IRQ_HANDLED;
567}
568
569void __init init_cio_interrupts(void)
570{
571	irq_set_chip_and_handler(IO_INTERRUPT,
572				 &dummy_irq_chip, handle_percpu_irq);
573	if (request_irq(IO_INTERRUPT, do_cio_interrupt, 0, "I/O", NULL))
574		panic("Failed to register I/O interrupt\n");
575}
576
577#ifdef CONFIG_CCW_CONSOLE
578static struct subchannel *console_sch;
579static struct lock_class_key console_sch_key;
580
581/*
582 * Use cio_tsch to update the subchannel status and call the interrupt handler
583 * if status had been pending. Called with the subchannel's lock held.
584 */
585void cio_tsch(struct subchannel *sch)
586{
587	struct irb *irb;
588	int irq_context;
589
590	irb = this_cpu_ptr(&cio_irb);
591	/* Store interrupt response block to lowcore. */
592	if (tsch(sch->schid, irb) != 0)
593		/* Not status pending or not operational. */
594		return;
595	memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
596	/* Call interrupt handler with updated status. */
597	irq_context = in_interrupt();
598	if (!irq_context) {
599		local_bh_disable();
600		irq_enter();
601	}
602	kstat_incr_irq_this_cpu(IO_INTERRUPT);
603	if (sch->driver && sch->driver->irq)
604		sch->driver->irq(sch);
605	else
606		inc_irq_stat(IRQIO_CIO);
607	if (!irq_context) {
608		irq_exit();
609		_local_bh_enable();
610	}
611}
612
613static int cio_test_for_console(struct subchannel_id schid, void *data)
614{
615	struct schib schib;
616
617	if (stsch(schid, &schib) != 0)
618		return -ENXIO;
619	if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
620	    (schib.pmcw.dev == console_devno)) {
621		console_irq = schid.sch_no;
622		return 1; /* found */
623	}
624	return 0;
625}
626
627static int cio_get_console_sch_no(void)
628{
629	struct subchannel_id schid;
630	struct schib schib;
631
632	init_subchannel_id(&schid);
633	if (console_irq != -1) {
634		/* VM provided us with the irq number of the console. */
635		schid.sch_no = console_irq;
636		if (stsch(schid, &schib) != 0 ||
637		    (schib.pmcw.st != SUBCHANNEL_TYPE_IO) || !schib.pmcw.dnv)
638			return -1;
639		console_devno = schib.pmcw.dev;
640	} else if (console_devno != -1) {
641		/* At least the console device number is known. */
642		for_each_subchannel(cio_test_for_console, NULL);
643	}
644	return console_irq;
645}
646
647struct subchannel *cio_probe_console(void)
648{
649	struct subchannel_id schid;
650	struct subchannel *sch;
651	struct schib schib;
652	int sch_no, ret;
653
654	sch_no = cio_get_console_sch_no();
655	if (sch_no == -1) {
656		pr_warn("No CCW console was found\n");
657		return ERR_PTR(-ENODEV);
658	}
659	init_subchannel_id(&schid);
660	schid.sch_no = sch_no;
661	ret = stsch(schid, &schib);
662	if (ret)
663		return ERR_PTR(-ENODEV);
664
665	sch = css_alloc_subchannel(schid, &schib);
666	if (IS_ERR(sch))
667		return sch;
668
669	lockdep_set_class(&sch->lock, &console_sch_key);
670	isc_register(CONSOLE_ISC);
671	sch->config.isc = CONSOLE_ISC;
672	sch->config.intparm = (u32)virt_to_phys(sch);
673	ret = cio_commit_config(sch);
674	if (ret) {
675		isc_unregister(CONSOLE_ISC);
676		put_device(&sch->dev);
677		return ERR_PTR(ret);
678	}
679	console_sch = sch;
680	return sch;
681}
682
683int cio_is_console(struct subchannel_id schid)
684{
685	if (!console_sch)
686		return 0;
687	return schid_equal(&schid, &console_sch->schid);
688}
689
690void cio_register_early_subchannels(void)
691{
692	int ret;
693
694	if (!console_sch)
695		return;
696
697	ret = css_register_subchannel(console_sch);
698	if (ret)
699		put_device(&console_sch->dev);
700}
701#endif /* CONFIG_CCW_CONSOLE */
702
703/**
704 * cio_tm_start_key - perform start function
705 * @sch: subchannel on which to perform the start function
706 * @tcw: transport-command word to be started
707 * @lpm: mask of paths to use
708 * @key: storage key to use for storage access
709 *
710 * Start the tcw on the given subchannel. Return zero on success, non-zero
711 * otherwise.
712 */
713int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
714{
715	int cc;
716	union orb *orb = &to_io_private(sch)->orb;
717
718	memset(orb, 0, sizeof(union orb));
719	orb->tm.intparm = (u32)virt_to_phys(sch);
720	orb->tm.key = key >> 4;
721	orb->tm.b = 1;
722	orb->tm.lpm = lpm ? lpm : sch->lpm;
723	orb->tm.tcw = virt_to_dma32(tcw);
724	cc = ssch(sch->schid, orb);
725	switch (cc) {
726	case 0:
727		return 0;
728	case 1:
729	case 2:
730		return -EBUSY;
731	default:
732		return cio_start_handle_notoper(sch, lpm);
733	}
734}
735EXPORT_SYMBOL_GPL(cio_tm_start_key);
736
737/**
738 * cio_tm_intrg - perform interrogate function
739 * @sch: subchannel on which to perform the interrogate function
740 *
741 * If the specified subchannel is running in transport-mode, perform the
742 * interrogate function. Return zero on success, non-zero otherwie.
743 */
744int cio_tm_intrg(struct subchannel *sch)
745{
746	int cc;
747
748	if (!to_io_private(sch)->orb.tm.b)
749		return -EINVAL;
750	cc = xsch(sch->schid);
751	switch (cc) {
752	case 0:
753	case 2:
754		return 0;
755	case 1:
756		return -EBUSY;
757	default:
758		return -ENODEV;
759	}
760}
761EXPORT_SYMBOL_GPL(cio_tm_intrg);