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