1 // SPDX-License-Identifier: GPL-2.0
3 * S/390 common I/O routines -- low level i/o calls
5 * Copyright IBM Corp. 1999, 2008
12 #define KMSG_COMPONENT "cio"
13 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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>
24 #include <asm/delay.h>
26 #include <asm/irq_regs.h>
27 #include <asm/setup.h>
29 #include <asm/chpid.h>
32 #include <linux/sched/cputime.h>
41 #include "blacklist.h"
42 #include "cio_debug.h"
46 debug_info_t *cio_debug_msg_id;
47 debug_info_t *cio_debug_trace_id;
48 debug_info_t *cio_debug_crw_id;
50 DEFINE_PER_CPU_ALIGNED(struct irb, cio_irb);
51 EXPORT_PER_CPU_SYMBOL(cio_irb);
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
60 static int __init cio_debug_init(void)
62 cio_debug_msg_id = debug_register("cio_msg", 16, 1, 11 * sizeof(long));
63 if (!cio_debug_msg_id)
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)
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)
75 debug_register_view(cio_debug_crw_id, &debug_sprintf_view);
76 debug_set_level(cio_debug_crw_id, 4);
80 debug_unregister(cio_debug_msg_id);
81 debug_unregister(cio_debug_trace_id);
82 debug_unregister(cio_debug_crw_id);
86 arch_initcall (cio_debug_init);
88 int cio_set_options(struct subchannel *sch, int flags)
90 struct io_subchannel_private *priv = to_io_private(sch);
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;
99 cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
108 CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
109 "subchannel 0.%x.%04x!\n", sch->schid.ssid,
112 if (cio_update_schib(sch))
115 sprintf(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));
119 return (sch->lpm ? -EACCES : -ENODEV);
123 cio_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 */
128 struct io_subchannel_private *priv = to_io_private(sch);
129 union orb *orb = &priv->orb;
132 CIO_TRACE_EVENT(5, "stIO");
133 CIO_TRACE_EVENT(5, dev_name(&sch->dev));
135 memset(orb, 0, sizeof(union orb));
136 /* sch is always under 2G. */
137 orb->cmd.intparm = (u32)virt_to_phys(sch);
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;
145 * for 64 bit we always support 64 bit IDAWs with 4k page size only
149 orb->cmd.key = key >> 4;
150 /* issue "Start Subchannel" */
151 orb->cmd.cpa = virt_to_dma32(cpa);
152 ccode = ssch(sch->schid, orb);
154 /* process condition code */
155 CIO_HEX_EVENT(5, &ccode, sizeof(ccode));
160 * initialize device status information
162 sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
164 case 1: /* status pending */
167 case 3: /* device/path not operational */
168 return cio_start_handle_notoper(sch, lpm);
173 EXPORT_SYMBOL_GPL(cio_start_key);
176 cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
178 return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
180 EXPORT_SYMBOL_GPL(cio_start);
183 * resume suspended I/O operation
186 cio_resume (struct subchannel *sch)
190 CIO_TRACE_EVENT(4, "resIO");
191 CIO_TRACE_EVENT(4, dev_name(&sch->dev));
193 ccode = rsch (sch->schid);
195 CIO_HEX_EVENT(4, &ccode, sizeof(ccode));
199 sch->schib.scsw.cmd.actl |= SCSW_ACTL_RESUME_PEND;
207 * useless to wait for request completion
208 * as device is no longer operational !
213 EXPORT_SYMBOL_GPL(cio_resume);
219 cio_halt(struct subchannel *sch)
226 CIO_TRACE_EVENT(2, "haltIO");
227 CIO_TRACE_EVENT(2, dev_name(&sch->dev));
230 * Issue "Halt subchannel" and process condition code
232 ccode = hsch (sch->schid);
234 CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
238 sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND;
240 case 1: /* status pending */
243 default: /* device not operational */
247 EXPORT_SYMBOL_GPL(cio_halt);
250 * Clear I/O operation
253 cio_clear(struct subchannel *sch)
260 CIO_TRACE_EVENT(2, "clearIO");
261 CIO_TRACE_EVENT(2, dev_name(&sch->dev));
264 * Issue "Clear subchannel" and process condition code
266 ccode = csch (sch->schid);
268 CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
272 sch->schib.scsw.cmd.actl |= SCSW_ACTL_CLEAR_PEND;
274 default: /* device not operational */
278 EXPORT_SYMBOL_GPL(cio_clear);
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.
288 cio_cancel (struct subchannel *sch)
295 CIO_TRACE_EVENT(2, "cancelIO");
296 CIO_TRACE_EVENT(2, dev_name(&sch->dev));
298 ccode = xsch (sch->schid);
300 CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
303 case 0: /* success */
304 /* Update information in scsw. */
305 if (cio_update_schib(sch))
308 case 1: /* status pending */
310 case 2: /* not applicable */
312 default: /* not oper */
316 EXPORT_SYMBOL_GPL(cio_cancel);
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
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.
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.
334 int cio_cancel_halt_clear(struct subchannel *sch, int *iretry)
338 if (cio_update_schib(sch))
340 if (!sch->schib.pmcw.ena)
341 /* Not operational -> done. */
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);
352 * Cancel io unsuccessful or not applicable (transport mode).
353 * Continue with asynchronous instructions.
355 *iretry = 3; /* 3 halt retries. */
357 /* Stage 2: halt io. */
358 if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
363 return (ret == 0) ? -EBUSY : ret;
365 /* Halt io unsuccessful. */
366 *iretry = 255; /* 255 clear retries. */
368 /* Stage 3: clear io. */
371 ret = cio_clear(sch);
372 return (ret == 0) ? -EBUSY : ret;
374 /* Function was unsuccessful */
377 EXPORT_SYMBOL_GPL(cio_cancel_halt_clear);
379 static void cio_apply_config(struct subchannel *sch, struct schib *schib)
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;
393 static int cio_check_config(struct subchannel *sch, struct schib *schib)
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));
407 * cio_commit_config - apply configuration to the subchannel
409 int cio_commit_config(struct subchannel *sch)
411 int ccode, retry, ret = 0;
415 if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
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. */
425 case 0: /* successful */
426 if (stsch(sch->schid, &schib) ||
427 !css_sch_is_valid(&schib))
429 if (cio_check_config(sch, &schib)) {
430 /* commit changes from local schib */
431 memcpy(&sch->schib, &schib, sizeof(schib));
436 case 1: /* status pending */
438 if (tsch(sch->schid, &irb))
442 udelay(100); /* allow for recovery */
445 case 3: /* not operational */
451 EXPORT_SYMBOL_GPL(cio_commit_config);
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.
458 int cio_update_schib(struct subchannel *sch)
462 if (stsch(sch->schid, &schib))
465 memcpy(&sch->schib, &schib, sizeof(schib));
467 if (!css_sch_is_valid(&schib))
472 EXPORT_SYMBOL_GPL(cio_update_schib);
475 * cio_enable_subchannel - enable a subchannel.
476 * @sch: subchannel to be enabled
477 * @intparm: interruption parameter to set
479 int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
483 CIO_TRACE_EVENT(2, "ensch");
484 CIO_TRACE_EVENT(2, dev_name(&sch->dev));
486 if (sch_is_pseudo_sch(sch))
488 if (cio_update_schib(sch))
492 sch->config.isc = sch->isc;
493 sch->config.intparm = intparm;
495 ret = cio_commit_config(sch);
498 * Got a program check in msch. Try without
499 * the concurrent sense bit the next time.
501 sch->config.csense = 0;
502 ret = cio_commit_config(sch);
504 CIO_HEX_EVENT(2, &ret, sizeof(ret));
507 EXPORT_SYMBOL_GPL(cio_enable_subchannel);
510 * cio_disable_subchannel - disable a subchannel.
511 * @sch: subchannel to disable
513 int cio_disable_subchannel(struct subchannel *sch)
517 CIO_TRACE_EVENT(2, "dissch");
518 CIO_TRACE_EVENT(2, dev_name(&sch->dev));
520 if (sch_is_pseudo_sch(sch))
522 if (cio_update_schib(sch))
526 ret = cio_commit_config(sch);
528 CIO_HEX_EVENT(2, &ret, sizeof(ret));
531 EXPORT_SYMBOL_GPL(cio_disable_subchannel);
534 * do_cio_interrupt() handles all normal I/O device IRQ's
536 static irqreturn_t do_cio_interrupt(int irq, void *dummy)
538 struct tpi_info *tpi_info;
539 struct subchannel *sch;
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);
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);
561 inc_irq_stat(IRQIO_CIO);
563 inc_irq_stat(IRQIO_CIO);
564 spin_unlock(&sch->lock);
569 void __init init_cio_interrupts(void)
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");
577 #ifdef CONFIG_CCW_CONSOLE
578 static struct subchannel *console_sch;
579 static struct lock_class_key console_sch_key;
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.
585 void cio_tsch(struct subchannel *sch)
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. */
595 memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
596 /* Call interrupt handler with updated status. */
597 irq_context = in_interrupt();
602 kstat_incr_irq_this_cpu(IO_INTERRUPT);
603 if (sch->driver && sch->driver->irq)
604 sch->driver->irq(sch);
606 inc_irq_stat(IRQIO_CIO);
613 static int cio_test_for_console(struct subchannel_id schid, void *data)
617 if (stsch(schid, &schib) != 0)
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 */
627 static int cio_get_console_sch_no(void)
629 struct subchannel_id schid;
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)
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);
647 struct subchannel *cio_probe_console(void)
649 struct subchannel_id schid;
650 struct subchannel *sch;
654 sch_no = cio_get_console_sch_no();
656 pr_warn("No CCW console was found\n");
657 return ERR_PTR(-ENODEV);
659 init_subchannel_id(&schid);
660 schid.sch_no = sch_no;
661 ret = stsch(schid, &schib);
663 return ERR_PTR(-ENODEV);
665 sch = css_alloc_subchannel(schid, &schib);
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);
675 isc_unregister(CONSOLE_ISC);
676 put_device(&sch->dev);
683 int cio_is_console(struct subchannel_id schid)
687 return schid_equal(&schid, &console_sch->schid);
690 void cio_register_early_subchannels(void)
697 ret = css_register_subchannel(console_sch);
699 put_device(&console_sch->dev);
701 #endif /* CONFIG_CCW_CONSOLE */
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
710 * Start the tcw on the given subchannel. Return zero on success, non-zero
713 int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
716 union orb *orb = &to_io_private(sch)->orb;
718 memset(orb, 0, sizeof(union orb));
719 orb->tm.intparm = (u32)virt_to_phys(sch);
720 orb->tm.key = key >> 4;
722 orb->tm.lpm = lpm ? lpm : sch->lpm;
723 orb->tm.tcw = virt_to_dma32(tcw);
724 cc = ssch(sch->schid, orb);
732 return cio_start_handle_notoper(sch, lpm);
735 EXPORT_SYMBOL_GPL(cio_tm_start_key);
738 * cio_tm_intrg - perform interrogate function
739 * @sch: subchannel on which to perform the interrogate function
741 * If the specified subchannel is running in transport-mode, perform the
742 * interrogate function. Return zero on success, non-zero otherwie.
744 int cio_tm_intrg(struct subchannel *sch)
748 if (!to_io_private(sch)->orb.tm.b)
750 cc = xsch(sch->schid);
761 EXPORT_SYMBOL_GPL(cio_tm_intrg);