drivers/s390/cio/cio.c

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