drivers/s390/cio/cio.c

   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 (adlung@de.ibm.com)
   6  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   7  *               Arnd Bergmann (arndb@de.ibm.com)
   8  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   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
  44 debug_info_t *cio_debug_msg_id;
  45 debug_info_t *cio_debug_trace_id;
  46 debug_info_t *cio_debug_crw_id;
  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
  86 int cio_set_options(struct subchannel *sch, int flags)
  87 {
  88         struct io_subchannel_private *priv = to_io_private(sch);
  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 {
 126         struct io_subchannel_private *priv = to_io_private(sch);
 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  */
 343 int cio_commit_config(struct subchannel *sch)
 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
 382 /**
 383  * cio_update_schib - Perform stsch and update schib if subchannel is valid.
 384  * @sch: subchannel on which to perform stsch
 385  * Return zero on success, -ENODEV otherwise.
 386  */
 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 }
 397 EXPORT_SYMBOL_GPL(cio_update_schib);
 398
 399 /**
 400  * cio_enable_subchannel - enable a subchannel.
 401  * @sch: subchannel to be enabled
 402  * @intparm: interruption parameter to set
 403  */
 404 int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
 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 }
 439 EXPORT_SYMBOL_GPL(cio_enable_subchannel);
 440
 441 /**
 442  * cio_disable_subchannel - disable a subchannel.
 443  * @sch: subchannel to disable
 444  */
 445 int cio_disable_subchannel(struct subchannel *sch)
 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 }
 472 EXPORT_SYMBOL_GPL(cio_disable_subchannel);
 473
 474 static int cio_check_devno_blacklisted(struct subchannel *sch)
 475 {
 476         if (is_blacklisted(sch->schid.ssid, sch->schib.pmcw.dev)) {
 477                 /*
 478                  * This device must not be known to Linux. So we simply
 479                  * say that there is no device and return ENODEV.
 480                  */
 481                 CIO_MSG_EVENT(6, "Blacklisted device detected "
 482                               "at devno %04X, subchannel set %x\n",
 483                               sch->schib.pmcw.dev, sch->schid.ssid);
 484                 return -ENODEV;
 485         }
 486         return 0;
 487 }
 488
 489 static int cio_validate_io_subchannel(struct subchannel *sch)
 490 {
 491         /* Initialization for io subchannels. */
 492         if (!css_sch_is_valid(&sch->schib))
 493                 return -ENODEV;
 494
 495         /* Devno is valid. */
 496         return cio_check_devno_blacklisted(sch);
 497 }
 498
 499 static int cio_validate_msg_subchannel(struct subchannel *sch)
 500 {
 501         /* Initialization for message 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 /**
 510  * cio_validate_subchannel - basic validation of subchannel
 511  * @sch: subchannel structure to be filled out
 512  * @schid: subchannel id
 513  *
 514  * Find out subchannel type and initialize struct subchannel.
 515  * Return codes:
 516  *   0 on success
 517  *   -ENXIO for non-defined subchannels
 518  *   -ENODEV for invalid subchannels or blacklisted devices
 519  *   -EIO for subchannels in an invalid subchannel set
 520  */
 521 int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
 522 {
 523         char dbf_txt[15];
 524         int ccode;
 525         int err;
 526
 527         sprintf(dbf_txt, "valsch%x", schid.sch_no);
 528         CIO_TRACE_EVENT(4, dbf_txt);
 529
 530         /*
 531          * The first subchannel that is not-operational (ccode==3)
 532          * indicates that there aren't any more devices available.
 533          * If stsch gets an exception, it means the current subchannel set
 534          * is not valid.
 535          */
 536         ccode = stsch_err(schid, &sch->schib);
 537         if (ccode) {
 538                 err = (ccode == 3) ? -ENXIO : ccode;
 539                 goto out;
 540         }
 541         sch->st = sch->schib.pmcw.st;
 542         sch->schid = schid;
 543
 544         switch (sch->st) {
 545         case SUBCHANNEL_TYPE_IO:
 546                 err = cio_validate_io_subchannel(sch);
 547                 break;
 548         case SUBCHANNEL_TYPE_MSG:
 549                 err = cio_validate_msg_subchannel(sch);
 550                 break;
 551         default:
 552                 err = 0;
 553         }
 554         if (err)
 555                 goto out;
 556
 557         CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
 558                       sch->schid.ssid, sch->schid.sch_no, sch->st);
 559 out:
 560         return err;
 561 }
 562
 563 /*
 564  * do_IRQ() handles all normal I/O device IRQ's (the special
 565  *          SMP cross-CPU interrupts have their own specific
 566  *          handlers).
 567  *
 568  */
 569 void __irq_entry do_IRQ(struct pt_regs *regs)
 570 {
 571         struct tpi_info *tpi_info;
 572         struct subchannel *sch;
 573         struct irb *irb;
 574         struct pt_regs *old_regs;
 575
 576         old_regs = set_irq_regs(regs);
 577         irq_enter();
 578         __this_cpu_write(s390_idle.nohz_delay, 1);
 579         if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
 580                 /* Serve timer interrupts first. */
 581                 clock_comparator_work();
 582         /*
 583          * Get interrupt information from lowcore
 584          */
 585         tpi_info = (struct tpi_info *)&S390_lowcore.subchannel_id;
 586         irb = (struct irb *)&S390_lowcore.irb;
 587         do {
 588                 kstat_incr_irqs_this_cpu(IO_INTERRUPT, NULL);
 589                 if (tpi_info->adapter_IO) {
 590                         do_adapter_IO(tpi_info->isc);
 591                         continue;
 592                 }
 593                 sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 594                 if (!sch) {
 595                         /* Clear pending interrupt condition. */
 596                         inc_irq_stat(IRQIO_CIO);
 597                         tsch(tpi_info->schid, irb);
 598                         continue;
 599                 }
 600                 spin_lock(sch->lock);
 601                 /* Store interrupt response block to lowcore. */
 602                 if (tsch(tpi_info->schid, irb) == 0) {
 603                         /* Keep subchannel information word up to date. */
 604                         memcpy (&sch->schib.scsw, &irb->scsw,
 605                                 sizeof (irb->scsw));
 606                         /* Call interrupt handler if there is one. */
 607                         if (sch->driver && sch->driver->irq)
 608                                 sch->driver->irq(sch);
 609                         else
 610                                 inc_irq_stat(IRQIO_CIO);
 611                 } else
 612                         inc_irq_stat(IRQIO_CIO);
 613                 spin_unlock(sch->lock);
 614                 /*
 615                  * Are more interrupts pending?
 616                  * If so, the tpi instruction will update the lowcore
 617                  * to hold the info for the next interrupt.
 618                  * We don't do this for VM because a tpi drops the cpu
 619                  * out of the sie which costs more cycles than it saves.
 620                  */
 621         } while (MACHINE_IS_LPAR && tpi(NULL) != 0);
 622         irq_exit();
 623         set_irq_regs(old_regs);
 624 }
 625
 626 #ifdef CONFIG_CCW_CONSOLE
 627 static struct subchannel *console_sch;
 628
 629 /*
 630  * Use cio_tsch to update the subchannel status and call the interrupt handler
 631  * if status had been pending. Called with the subchannel's lock held.
 632  */
 633 void cio_tsch(struct subchannel *sch)
 634 {
 635         struct irb *irb;
 636         int irq_context;
 637
 638         irb = (struct irb *)&S390_lowcore.irb;
 639         /* Store interrupt response block to lowcore. */
 640         if (tsch(sch->schid, irb) != 0)
 641                 /* Not status pending or not operational. */
 642                 return;
 643         memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
 644         /* Call interrupt handler with updated status. */
 645         irq_context = in_interrupt();
 646         if (!irq_context) {
 647                 local_bh_disable();
 648                 irq_enter();
 649         }
 650         kstat_incr_irqs_this_cpu(IO_INTERRUPT, NULL);
 651         if (sch->driver && sch->driver->irq)
 652                 sch->driver->irq(sch);
 653         else
 654                 inc_irq_stat(IRQIO_CIO);
 655         if (!irq_context) {
 656                 irq_exit();
 657                 _local_bh_enable();
 658         }
 659 }
 660
 661 static int cio_test_for_console(struct subchannel_id schid, void *data)
 662 {
 663         struct schib schib;
 664
 665         if (stsch_err(schid, &schib) != 0)
 666                 return -ENXIO;
 667         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
 668             (schib.pmcw.dev == console_devno)) {
 669                 console_irq = schid.sch_no;
 670                 return 1; /* found */
 671         }
 672         return 0;
 673 }
 674
 675 static int cio_get_console_sch_no(void)
 676 {
 677         struct subchannel_id schid;
 678         struct schib schib;
 679
 680         init_subchannel_id(&schid);
 681         if (console_irq != -1) {
 682                 /* VM provided us with the irq number of the console. */
 683                 schid.sch_no = console_irq;
 684                 if (stsch_err(schid, &schib) != 0 ||
 685                     (schib.pmcw.st != SUBCHANNEL_TYPE_IO) || !schib.pmcw.dnv)
 686                         return -1;
 687                 console_devno = schib.pmcw.dev;
 688         } else if (console_devno != -1) {
 689                 /* At least the console device number is known. */
 690                 for_each_subchannel(cio_test_for_console, NULL);
 691         }
 692         return console_irq;
 693 }
 694
 695 struct subchannel *cio_probe_console(void)
 696 {
 697         struct subchannel_id schid;
 698         struct subchannel *sch;
 699         int sch_no, ret;
 700
 701         sch_no = cio_get_console_sch_no();
 702         if (sch_no == -1) {
 703                 pr_warning("No CCW console was found\n");
 704                 return ERR_PTR(-ENODEV);
 705         }
 706         init_subchannel_id(&schid);
 707         schid.sch_no = sch_no;
 708         sch = css_alloc_subchannel(schid);
 709         if (IS_ERR(sch))
 710                 return sch;
 711
 712         isc_register(CONSOLE_ISC);
 713         sch->config.isc = CONSOLE_ISC;
 714         sch->config.intparm = (u32)(addr_t)sch;
 715         ret = cio_commit_config(sch);
 716         if (ret) {
 717                 isc_unregister(CONSOLE_ISC);
 718                 put_device(&sch->dev);
 719                 return ERR_PTR(ret);
 720         }
 721         console_sch = sch;
 722         return sch;
 723 }
 724
 725 int cio_is_console(struct subchannel_id schid)
 726 {
 727         if (!console_sch)
 728                 return 0;
 729         return schid_equal(&schid, &console_sch->schid);
 730 }
 731
 732 void cio_register_early_subchannels(void)
 733 {
 734         int ret;
 735
 736         if (!console_sch)
 737                 return;
 738
 739         ret = css_register_subchannel(console_sch);
 740         if (ret)
 741                 put_device(&console_sch->dev);
 742 }
 743 #endif /* CONFIG_CCW_CONSOLE */
 744
 745 static int
 746 __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
 747 {
 748         int retry, cc;
 749
 750         cc = 0;
 751         for (retry=0;retry<3;retry++) {
 752                 schib->pmcw.ena = 0;
 753                 cc = msch_err(schid, schib);
 754                 if (cc)
 755                         return (cc==3?-ENODEV:-EBUSY);
 756                 if (stsch_err(schid, schib) || !css_sch_is_valid(schib))
 757                         return -ENODEV;
 758                 if (!schib->pmcw.ena)
 759                         return 0;
 760         }
 761         return -EBUSY; /* uhm... */
 762 }
 763
 764 static int
 765 __clear_io_subchannel_easy(struct subchannel_id schid)
 766 {
 767         int retry;
 768
 769         if (csch(schid))
 770                 return -ENODEV;
 771         for (retry=0;retry<20;retry++) {
 772                 struct tpi_info ti;
 773
 774                 if (tpi(&ti)) {
 775                         tsch(ti.schid, (struct irb *)&S390_lowcore.irb);
 776                         if (schid_equal(&ti.schid, &schid))
 777                                 return 0;
 778                 }
 779                 udelay_simple(100);
 780         }
 781         return -EBUSY;
 782 }
 783
 784 static void __clear_chsc_subchannel_easy(void)
 785 {
 786         /* It seems we can only wait for a bit here :/ */
 787         udelay_simple(100);
 788 }
 789
 790 static int pgm_check_occured;
 791
 792 static void cio_reset_pgm_check_handler(void)
 793 {
 794         pgm_check_occured = 1;
 795 }
 796
 797 static int stsch_reset(struct subchannel_id schid, struct schib *addr)
 798 {
 799         int rc;
 800
 801         pgm_check_occured = 0;
 802         s390_base_pgm_handler_fn = cio_reset_pgm_check_handler;
 803         rc = stsch_err(schid, addr);
 804         s390_base_pgm_handler_fn = NULL;
 805
 806         /* The program check handler could have changed pgm_check_occured. */
 807         barrier();
 808
 809         if (pgm_check_occured)
 810                 return -EIO;
 811         else
 812                 return rc;
 813 }
 814
 815 static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
 816 {
 817         struct schib schib;
 818
 819         if (stsch_reset(schid, &schib))
 820                 return -ENXIO;
 821         if (!schib.pmcw.ena)
 822                 return 0;
 823         switch(__disable_subchannel_easy(schid, &schib)) {
 824         case 0:
 825         case -ENODEV:
 826                 break;
 827         default: /* -EBUSY */
 828                 switch (schib.pmcw.st) {
 829                 case SUBCHANNEL_TYPE_IO:
 830                         if (__clear_io_subchannel_easy(schid))
 831                                 goto out; /* give up... */
 832                         break;
 833                 case SUBCHANNEL_TYPE_CHSC:
 834                         __clear_chsc_subchannel_easy();
 835                         break;
 836                 default:
 837                         /* No default clear strategy */
 838                         break;
 839                 }
 840                 stsch_err(schid, &schib);
 841                 __disable_subchannel_easy(schid, &schib);
 842         }
 843 out:
 844         return 0;
 845 }
 846
 847 static atomic_t chpid_reset_count;
 848
 849 static void s390_reset_chpids_mcck_handler(void)
 850 {
 851         struct crw crw;
 852         struct mci *mci;
 853
 854         /* Check for pending channel report word. */
 855         mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
 856         if (!mci->cp)
 857                 return;
 858         /* Process channel report words. */
 859         while (stcrw(&crw) == 0) {
 860                 /* Check for responses to RCHP. */
 861                 if (crw.slct && crw.rsc == CRW_RSC_CPATH)
 862                         atomic_dec(&chpid_reset_count);
 863         }
 864 }
 865
 866 #define RCHP_TIMEOUT (30 * USEC_PER_SEC)
 867 static void css_reset(void)
 868 {
 869         int i, ret;
 870         unsigned long long timeout;
 871         struct chp_id chpid;
 872
 873         /* Reset subchannels. */
 874         for_each_subchannel(__shutdown_subchannel_easy,  NULL);
 875         /* Reset channel paths. */
 876         s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler;
 877         /* Enable channel report machine checks. */
 878         __ctl_set_bit(14, 28);
 879         /* Temporarily reenable machine checks. */
 880         local_mcck_enable();
 881         chp_id_init(&chpid);
 882         for (i = 0; i <= __MAX_CHPID; i++) {
 883                 chpid.id = i;
 884                 ret = rchp(chpid);
 885                 if ((ret == 0) || (ret == 2))
 886                         /*
 887                          * rchp either succeeded, or another rchp is already
 888                          * in progress. In either case, we'll get a crw.
 889                          */
 890                         atomic_inc(&chpid_reset_count);
 891         }
 892         /* Wait for machine check for all channel paths. */
 893         timeout = get_tod_clock() + (RCHP_TIMEOUT << 12);
 894         while (atomic_read(&chpid_reset_count) != 0) {
 895                 if (get_tod_clock() > timeout)
 896                         break;
 897                 cpu_relax();
 898         }
 899         /* Disable machine checks again. */
 900         local_mcck_disable();
 901         /* Disable channel report machine checks. */
 902         __ctl_clear_bit(14, 28);
 903         s390_base_mcck_handler_fn = NULL;
 904 }
 905
 906 static struct reset_call css_reset_call = {
 907         .fn = css_reset,
 908 };
 909
 910 static int __init init_css_reset_call(void)
 911 {
 912         atomic_set(&chpid_reset_count, 0);
 913         register_reset_call(&css_reset_call);
 914         return 0;
 915 }
 916
 917 arch_initcall(init_css_reset_call);
 918
 919 struct sch_match_id {
 920         struct subchannel_id schid;
 921         struct ccw_dev_id devid;
 922         int rc;
 923 };
 924
 925 static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
 926 {
 927         struct schib schib;
 928         struct sch_match_id *match_id = data;
 929
 930         if (stsch_reset(schid, &schib))
 931                 return -ENXIO;
 932         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
 933             (schib.pmcw.dev == match_id->devid.devno) &&
 934             (schid.ssid == match_id->devid.ssid)) {
 935                 match_id->schid = schid;
 936                 match_id->rc = 0;
 937                 return 1;
 938         }
 939         return 0;
 940 }
 941
 942 static int reipl_find_schid(struct ccw_dev_id *devid,
 943                             struct subchannel_id *schid)
 944 {
 945         struct sch_match_id match_id;
 946
 947         match_id.devid = *devid;
 948         match_id.rc = -ENODEV;
 949         for_each_subchannel(__reipl_subchannel_match, &match_id);
 950         if (match_id.rc == 0)
 951                 *schid = match_id.schid;
 952         return match_id.rc;
 953 }
 954
 955 extern void do_reipl_asm(__u32 schid);
 956
 957 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
 958 void reipl_ccw_dev(struct ccw_dev_id *devid)
 959 {
 960         struct subchannel_id uninitialized_var(schid);
 961
 962         s390_reset_system(NULL, NULL);
 963         if (reipl_find_schid(devid, &schid) != 0)
 964                 panic("IPL Device not found\n");
 965         do_reipl_asm(*((__u32*)&schid));
 966 }
 967
 968 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
 969 {
 970         struct subchannel_id schid;
 971         struct schib schib;
 972
 973         schid = *(struct subchannel_id *)&S390_lowcore.subchannel_id;
 974         if (!schid.one)
 975                 return -ENODEV;
 976         if (stsch_err(schid, &schib))
 977                 return -ENODEV;
 978         if (schib.pmcw.st != SUBCHANNEL_TYPE_IO)
 979                 return -ENODEV;
 980         if (!schib.pmcw.dnv)
 981                 return -ENODEV;
 982         iplinfo->devno = schib.pmcw.dev;
 983         iplinfo->is_qdio = schib.pmcw.qf;
 984         return 0;
 985 }
 986
 987 /**
 988  * cio_tm_start_key - perform start function
 989  * @sch: subchannel on which to perform the start function
 990  * @tcw: transport-command word to be started
 991  * @lpm: mask of paths to use
 992  * @key: storage key to use for storage access
 993  *
 994  * Start the tcw on the given subchannel. Return zero on success, non-zero
 995  * otherwise.
 996  */
 997 int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
 998 {
 999         int cc;
1000         union orb *orb = &to_io_private(sch)->orb;
1001
1002         memset(orb, 0, sizeof(union orb));
1003         orb->tm.intparm = (u32) (addr_t) sch;
1004         orb->tm.key = key >> 4;
1005         orb->tm.b = 1;
1006         orb->tm.lpm = lpm ? lpm : sch->lpm;
1007         orb->tm.tcw = (u32) (addr_t) tcw;
1008         cc = ssch(sch->schid, orb);
1009         switch (cc) {
1010         case 0:
1011                 return 0;
1012         case 1:
1013         case 2:
1014                 return -EBUSY;
1015         default:
1016                 return cio_start_handle_notoper(sch, lpm);
1017         }
1018 }
1019
1020 /**
1021  * cio_tm_intrg - perform interrogate function
1022  * @sch - subchannel on which to perform the interrogate function
1023  *
1024  * If the specified subchannel is running in transport-mode, perform the
1025  * interrogate function. Return zero on success, non-zero otherwie.
1026  */
1027 int cio_tm_intrg(struct subchannel *sch)
1028 {
1029         int cc;
1030
1031         if (!to_io_private(sch)->orb.tm.b)
1032                 return -EINVAL;
1033         cc = xsch(sch->schid);
1034         switch (cc) {
1035         case 0:
1036         case 2:
1037                 return 0;
1038         case 1:
1039                 return -EBUSY;
1040         default:
1041                 return -ENODEV;
1042         }
1043 }