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
  88 cio_set_options (struct subchannel *sch, int flags)
  89 {
  90        sch->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
  91        sch->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
  92        sch->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
  93        return 0;
  94 }
  95
  96 /* FIXME: who wants to use this? */
  97 int
  98 cio_get_options (struct subchannel *sch)
  99 {
 100        int flags;
 101
 102        flags = 0;
 103        if (sch->options.suspend)
 104                 flags |= DOIO_ALLOW_SUSPEND;
 105        if (sch->options.prefetch)
 106                 flags |= DOIO_DENY_PREFETCH;
 107        if (sch->options.inter)
 108                 flags |= DOIO_SUPPRESS_INTER;
 109        return flags;
 110 }
 111
 112 static int
 113 cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
 114 {
 115         char dbf_text[15];
 116
 117         if (lpm != 0)
 118                 sch->lpm &= ~lpm;
 119         else
 120                 sch->lpm = 0;
 121
 122         CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
 123                       "subchannel 0.%x.%04x!\n", sch->schid.ssid,
 124                       sch->schid.sch_no);
 125
 126         if (cio_update_schib(sch))
 127                 return -ENODEV;
 128
 129         sprintf(dbf_text, "no%s", dev_name(&sch->dev));
 130         CIO_TRACE_EVENT(0, dbf_text);
 131         CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
 132
 133         return (sch->lpm ? -EACCES : -ENODEV);
 134 }
 135
 136 int
 137 cio_start_key (struct subchannel *sch,  /* subchannel structure */
 138                struct ccw1 * cpa,       /* logical channel prog addr */
 139                __u8 lpm,                /* logical path mask */
 140                __u8 key)                /* storage key */
 141 {
 142         int ccode;
 143         union orb *orb;
 144
 145         CIO_TRACE_EVENT(5, "stIO");
 146         CIO_TRACE_EVENT(5, dev_name(&sch->dev));
 147
 148         orb = &to_io_private(sch)->orb;
 149         memset(orb, 0, sizeof(union orb));
 150         /* sch is always under 2G. */
 151         orb->cmd.intparm = (u32)(addr_t)sch;
 152         orb->cmd.fmt = 1;
 153
 154         orb->cmd.pfch = sch->options.prefetch == 0;
 155         orb->cmd.spnd = sch->options.suspend;
 156         orb->cmd.ssic = sch->options.suspend && sch->options.inter;
 157         orb->cmd.lpm = (lpm != 0) ? lpm : sch->lpm;
 158 #ifdef CONFIG_64BIT
 159         /*
 160          * for 64 bit we always support 64 bit IDAWs with 4k page size only
 161          */
 162         orb->cmd.c64 = 1;
 163         orb->cmd.i2k = 0;
 164 #endif
 165         orb->cmd.key = key >> 4;
 166         /* issue "Start Subchannel" */
 167         orb->cmd.cpa = (__u32) __pa(cpa);
 168         ccode = ssch(sch->schid, orb);
 169
 170         /* process condition code */
 171         CIO_HEX_EVENT(5, &ccode, sizeof(ccode));
 172
 173         switch (ccode) {
 174         case 0:
 175                 /*
 176                  * initialize device status information
 177                  */
 178                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
 179                 return 0;
 180         case 1:         /* status pending */
 181         case 2:         /* busy */
 182                 return -EBUSY;
 183         case 3:         /* device/path not operational */
 184                 return cio_start_handle_notoper(sch, lpm);
 185         default:
 186                 return ccode;
 187         }
 188 }
 189
 190 int
 191 cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
 192 {
 193         return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
 194 }
 195
 196 /*
 197  * resume suspended I/O operation
 198  */
 199 int
 200 cio_resume (struct subchannel *sch)
 201 {
 202         int ccode;
 203
 204         CIO_TRACE_EVENT(4, "resIO");
 205         CIO_TRACE_EVENT(4, dev_name(&sch->dev));
 206
 207         ccode = rsch (sch->schid);
 208
 209         CIO_HEX_EVENT(4, &ccode, sizeof(ccode));
 210
 211         switch (ccode) {
 212         case 0:
 213                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_RESUME_PEND;
 214                 return 0;
 215         case 1:
 216                 return -EBUSY;
 217         case 2:
 218                 return -EINVAL;
 219         default:
 220                 /*
 221                  * useless to wait for request completion
 222                  *  as device is no longer operational !
 223                  */
 224                 return -ENODEV;
 225         }
 226 }
 227
 228 /*
 229  * halt I/O operation
 230  */
 231 int
 232 cio_halt(struct subchannel *sch)
 233 {
 234         int ccode;
 235
 236         if (!sch)
 237                 return -ENODEV;
 238
 239         CIO_TRACE_EVENT(2, "haltIO");
 240         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 241
 242         /*
 243          * Issue "Halt subchannel" and process condition code
 244          */
 245         ccode = hsch (sch->schid);
 246
 247         CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
 248
 249         switch (ccode) {
 250         case 0:
 251                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND;
 252                 return 0;
 253         case 1:         /* status pending */
 254         case 2:         /* busy */
 255                 return -EBUSY;
 256         default:                /* device not operational */
 257                 return -ENODEV;
 258         }
 259 }
 260
 261 /*
 262  * Clear I/O operation
 263  */
 264 int
 265 cio_clear(struct subchannel *sch)
 266 {
 267         int ccode;
 268
 269         if (!sch)
 270                 return -ENODEV;
 271
 272         CIO_TRACE_EVENT(2, "clearIO");
 273         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 274
 275         /*
 276          * Issue "Clear subchannel" and process condition code
 277          */
 278         ccode = csch (sch->schid);
 279
 280         CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
 281
 282         switch (ccode) {
 283         case 0:
 284                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_CLEAR_PEND;
 285                 return 0;
 286         default:                /* device not operational */
 287                 return -ENODEV;
 288         }
 289 }
 290
 291 /*
 292  * Function: cio_cancel
 293  * Issues a "Cancel Subchannel" on the specified subchannel
 294  * Note: We don't need any fancy intparms and flags here
 295  *       since xsch is executed synchronously.
 296  * Only for common I/O internal use as for now.
 297  */
 298 int
 299 cio_cancel (struct subchannel *sch)
 300 {
 301         int ccode;
 302
 303         if (!sch)
 304                 return -ENODEV;
 305
 306         CIO_TRACE_EVENT(2, "cancelIO");
 307         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 308
 309         ccode = xsch (sch->schid);
 310
 311         CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
 312
 313         switch (ccode) {
 314         case 0:         /* success */
 315                 /* Update information in scsw. */
 316                 if (cio_update_schib(sch))
 317                         return -ENODEV;
 318                 return 0;
 319         case 1:         /* status pending */
 320                 return -EBUSY;
 321         case 2:         /* not applicable */
 322                 return -EINVAL;
 323         default:        /* not oper */
 324                 return -ENODEV;
 325         }
 326 }
 327
 328
 329 static void cio_apply_config(struct subchannel *sch, struct schib *schib)
 330 {
 331         schib->pmcw.intparm = sch->config.intparm;
 332         schib->pmcw.mbi = sch->config.mbi;
 333         schib->pmcw.isc = sch->config.isc;
 334         schib->pmcw.ena = sch->config.ena;
 335         schib->pmcw.mme = sch->config.mme;
 336         schib->pmcw.mp = sch->config.mp;
 337         schib->pmcw.csense = sch->config.csense;
 338         schib->pmcw.mbfc = sch->config.mbfc;
 339         if (sch->config.mbfc)
 340                 schib->mba = sch->config.mba;
 341 }
 342
 343 static int cio_check_config(struct subchannel *sch, struct schib *schib)
 344 {
 345         return (schib->pmcw.intparm == sch->config.intparm) &&
 346                 (schib->pmcw.mbi == sch->config.mbi) &&
 347                 (schib->pmcw.isc == sch->config.isc) &&
 348                 (schib->pmcw.ena == sch->config.ena) &&
 349                 (schib->pmcw.mme == sch->config.mme) &&
 350                 (schib->pmcw.mp == sch->config.mp) &&
 351                 (schib->pmcw.csense == sch->config.csense) &&
 352                 (schib->pmcw.mbfc == sch->config.mbfc) &&
 353                 (!sch->config.mbfc || (schib->mba == sch->config.mba));
 354 }
 355
 356 /*
 357  * cio_commit_config - apply configuration to the subchannel
 358  */
 359 int cio_commit_config(struct subchannel *sch)
 360 {
 361         struct schib schib;
 362         int ccode, retry, ret = 0;
 363
 364         if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
 365                 return -ENODEV;
 366
 367         for (retry = 0; retry < 5; retry++) {
 368                 /* copy desired changes to local schib */
 369                 cio_apply_config(sch, &schib);
 370                 ccode = msch_err(sch->schid, &schib);
 371                 if (ccode < 0) /* -EIO if msch gets a program check. */
 372                         return ccode;
 373                 switch (ccode) {
 374                 case 0: /* successful */
 375                         if (stsch(sch->schid, &schib) ||
 376                             !css_sch_is_valid(&schib))
 377                                 return -ENODEV;
 378                         if (cio_check_config(sch, &schib)) {
 379                                 /* commit changes from local schib */
 380                                 memcpy(&sch->schib, &schib, sizeof(schib));
 381                                 return 0;
 382                         }
 383                         ret = -EAGAIN;
 384                         break;
 385                 case 1: /* status pending */
 386                         return -EBUSY;
 387                 case 2: /* busy */
 388                         udelay(100); /* allow for recovery */
 389                         ret = -EBUSY;
 390                         break;
 391                 case 3: /* not operational */
 392                         return -ENODEV;
 393                 }
 394         }
 395         return ret;
 396 }
 397
 398 /**
 399  * cio_update_schib - Perform stsch and update schib if subchannel is valid.
 400  * @sch: subchannel on which to perform stsch
 401  * Return zero on success, -ENODEV otherwise.
 402  */
 403 int cio_update_schib(struct subchannel *sch)
 404 {
 405         struct schib schib;
 406
 407         if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
 408                 return -ENODEV;
 409
 410         memcpy(&sch->schib, &schib, sizeof(schib));
 411         return 0;
 412 }
 413 EXPORT_SYMBOL_GPL(cio_update_schib);
 414
 415 /**
 416  * cio_enable_subchannel - enable a subchannel.
 417  * @sch: subchannel to be enabled
 418  * @intparm: interruption parameter to set
 419  */
 420 int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
 421 {
 422         int retry;
 423         int ret;
 424
 425         CIO_TRACE_EVENT(2, "ensch");
 426         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 427
 428         if (sch_is_pseudo_sch(sch))
 429                 return -EINVAL;
 430         if (cio_update_schib(sch))
 431                 return -ENODEV;
 432
 433         sch->config.ena = 1;
 434         sch->config.isc = sch->isc;
 435         sch->config.intparm = intparm;
 436
 437         for (retry = 0; retry < 3; retry++) {
 438                 ret = cio_commit_config(sch);
 439                 if (ret == -EIO) {
 440                         /*
 441                          * Got a program check in msch. Try without
 442                          * the concurrent sense bit the next time.
 443                          */
 444                         sch->config.csense = 0;
 445                 } else if (ret == -EBUSY) {
 446                         struct irb irb;
 447                         if (tsch(sch->schid, &irb) != 0)
 448                                 break;
 449                 } else
 450                         break;
 451         }
 452         CIO_HEX_EVENT(2, &ret, sizeof(ret));
 453         return ret;
 454 }
 455 EXPORT_SYMBOL_GPL(cio_enable_subchannel);
 456
 457 /**
 458  * cio_disable_subchannel - disable a subchannel.
 459  * @sch: subchannel to disable
 460  */
 461 int cio_disable_subchannel(struct subchannel *sch)
 462 {
 463         int retry;
 464         int ret;
 465
 466         CIO_TRACE_EVENT(2, "dissch");
 467         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 468
 469         if (sch_is_pseudo_sch(sch))
 470                 return 0;
 471         if (cio_update_schib(sch))
 472                 return -ENODEV;
 473
 474         sch->config.ena = 0;
 475
 476         for (retry = 0; retry < 3; retry++) {
 477                 ret = cio_commit_config(sch);
 478                 if (ret == -EBUSY) {
 479                         struct irb irb;
 480                         if (tsch(sch->schid, &irb) != 0)
 481                                 break;
 482                 } else
 483                         break;
 484         }
 485         CIO_HEX_EVENT(2, &ret, sizeof(ret));
 486         return ret;
 487 }
 488 EXPORT_SYMBOL_GPL(cio_disable_subchannel);
 489
 490 int cio_create_sch_lock(struct subchannel *sch)
 491 {
 492         sch->lock = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
 493         if (!sch->lock)
 494                 return -ENOMEM;
 495         spin_lock_init(sch->lock);
 496         return 0;
 497 }
 498
 499 static int cio_check_devno_blacklisted(struct subchannel *sch)
 500 {
 501         if (is_blacklisted(sch->schid.ssid, sch->schib.pmcw.dev)) {
 502                 /*
 503                  * This device must not be known to Linux. So we simply
 504                  * say that there is no device and return ENODEV.
 505                  */
 506                 CIO_MSG_EVENT(6, "Blacklisted device detected "
 507                               "at devno %04X, subchannel set %x\n",
 508                               sch->schib.pmcw.dev, sch->schid.ssid);
 509                 return -ENODEV;
 510         }
 511         return 0;
 512 }
 513
 514 static int cio_validate_io_subchannel(struct subchannel *sch)
 515 {
 516         /* Initialization for io subchannels. */
 517         if (!css_sch_is_valid(&sch->schib))
 518                 return -ENODEV;
 519
 520         /* Devno is valid. */
 521         return cio_check_devno_blacklisted(sch);
 522 }
 523
 524 static int cio_validate_msg_subchannel(struct subchannel *sch)
 525 {
 526         /* Initialization for message subchannels. */
 527         if (!css_sch_is_valid(&sch->schib))
 528                 return -ENODEV;
 529
 530         /* Devno is valid. */
 531         return cio_check_devno_blacklisted(sch);
 532 }
 533
 534 /**
 535  * cio_validate_subchannel - basic validation of subchannel
 536  * @sch: subchannel structure to be filled out
 537  * @schid: subchannel id
 538  *
 539  * Find out subchannel type and initialize struct subchannel.
 540  * Return codes:
 541  *   0 on success
 542  *   -ENXIO for non-defined subchannels
 543  *   -ENODEV for invalid subchannels or blacklisted devices
 544  *   -EIO for subchannels in an invalid subchannel set
 545  */
 546 int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
 547 {
 548         char dbf_txt[15];
 549         int ccode;
 550         int err;
 551
 552         sprintf(dbf_txt, "valsch%x", schid.sch_no);
 553         CIO_TRACE_EVENT(4, dbf_txt);
 554
 555         /* Nuke all fields. */
 556         memset(sch, 0, sizeof(struct subchannel));
 557
 558         sch->schid = schid;
 559         if (cio_is_console(schid)) {
 560                 sch->lock = cio_get_console_lock();
 561         } else {
 562                 err = cio_create_sch_lock(sch);
 563                 if (err)
 564                         goto out;
 565         }
 566         mutex_init(&sch->reg_mutex);
 567
 568         /*
 569          * The first subchannel that is not-operational (ccode==3)
 570          *  indicates that there aren't any more devices available.
 571          * If stsch gets an exception, it means the current subchannel set
 572          *  is not valid.
 573          */
 574         ccode = stsch_err (schid, &sch->schib);
 575         if (ccode) {
 576                 err = (ccode == 3) ? -ENXIO : ccode;
 577                 goto out;
 578         }
 579         /* Copy subchannel type from path management control word. */
 580         sch->st = sch->schib.pmcw.st;
 581
 582         switch (sch->st) {
 583         case SUBCHANNEL_TYPE_IO:
 584                 err = cio_validate_io_subchannel(sch);
 585                 break;
 586         case SUBCHANNEL_TYPE_MSG:
 587                 err = cio_validate_msg_subchannel(sch);
 588                 break;
 589         default:
 590                 err = 0;
 591         }
 592         if (err)
 593                 goto out;
 594
 595         CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
 596                       sch->schid.ssid, sch->schid.sch_no, sch->st);
 597         return 0;
 598 out:
 599         if (!cio_is_console(schid))
 600                 kfree(sch->lock);
 601         sch->lock = NULL;
 602         return err;
 603 }
 604
 605 /*
 606  * do_IRQ() handles all normal I/O device IRQ's (the special
 607  *          SMP cross-CPU interrupts have their own specific
 608  *          handlers).
 609  *
 610  */
 611 void __irq_entry do_IRQ(struct pt_regs *regs)
 612 {
 613         struct tpi_info *tpi_info;
 614         struct subchannel *sch;
 615         struct irb *irb;
 616         struct pt_regs *old_regs;
 617
 618         old_regs = set_irq_regs(regs);
 619         s390_idle_check();
 620         irq_enter();
 621         if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
 622                 /* Serve timer interrupts first. */
 623                 clock_comparator_work();
 624         /*
 625          * Get interrupt information from lowcore
 626          */
 627         tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
 628         irb = (struct irb *) __LC_IRB;
 629         do {
 630                 kstat_cpu(smp_processor_id()).irqs[IO_INTERRUPT]++;
 631                 /*
 632                  * Non I/O-subchannel thin interrupts are processed differently
 633                  */
 634                 if (tpi_info->adapter_IO == 1 &&
 635                     tpi_info->int_type == IO_INTERRUPT_TYPE) {
 636                         do_adapter_IO(tpi_info->isc);
 637                         continue;
 638                 }
 639                 sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 640                 if (!sch) {
 641                         /* Clear pending interrupt condition. */
 642                         tsch(tpi_info->schid, irb);
 643                         continue;
 644                 }
 645                 spin_lock(sch->lock);
 646                 /* Store interrupt response block to lowcore. */
 647                 if (tsch(tpi_info->schid, irb) == 0) {
 648                         /* Keep subchannel information word up to date. */
 649                         memcpy (&sch->schib.scsw, &irb->scsw,
 650                                 sizeof (irb->scsw));
 651                         /* Call interrupt handler if there is one. */
 652                         if (sch->driver && sch->driver->irq)
 653                                 sch->driver->irq(sch);
 654                 }
 655                 spin_unlock(sch->lock);
 656                 /*
 657                  * Are more interrupts pending?
 658                  * If so, the tpi instruction will update the lowcore
 659                  * to hold the info for the next interrupt.
 660                  * We don't do this for VM because a tpi drops the cpu
 661                  * out of the sie which costs more cycles than it saves.
 662                  */
 663         } while (!MACHINE_IS_VM && tpi (NULL) != 0);
 664         irq_exit();
 665         set_irq_regs(old_regs);
 666 }
 667
 668 #ifdef CONFIG_CCW_CONSOLE
 669 static struct subchannel console_subchannel;
 670 static struct io_subchannel_private console_priv;
 671 static int console_subchannel_in_use;
 672
 673 /*
 674  * Use tpi to get a pending interrupt, call the interrupt handler and
 675  * return a pointer to the subchannel structure.
 676  */
 677 static int cio_tpi(void)
 678 {
 679         struct tpi_info *tpi_info;
 680         struct subchannel *sch;
 681         struct irb *irb;
 682         int irq_context;
 683
 684         tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
 685         if (tpi(NULL) != 1)
 686                 return 0;
 687         irb = (struct irb *) __LC_IRB;
 688         /* Store interrupt response block to lowcore. */
 689         if (tsch(tpi_info->schid, irb) != 0)
 690                 /* Not status pending or not operational. */
 691                 return 1;
 692         sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 693         if (!sch)
 694                 return 1;
 695         irq_context = in_interrupt();
 696         if (!irq_context)
 697                 local_bh_disable();
 698         irq_enter();
 699         spin_lock(sch->lock);
 700         memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
 701         if (sch->driver && sch->driver->irq)
 702                 sch->driver->irq(sch);
 703         spin_unlock(sch->lock);
 704         irq_exit();
 705         if (!irq_context)
 706                 _local_bh_enable();
 707         return 1;
 708 }
 709
 710 void *cio_get_console_priv(void)
 711 {
 712         return &console_priv;
 713 }
 714
 715 /*
 716  * busy wait for the next interrupt on the console
 717  */
 718 void wait_cons_dev(void)
 719         __releases(console_subchannel.lock)
 720         __acquires(console_subchannel.lock)
 721 {
 722         unsigned long cr6      __attribute__ ((aligned (8)));
 723         unsigned long save_cr6 __attribute__ ((aligned (8)));
 724
 725         /*
 726          * before entering the spinlock we may already have
 727          * processed the interrupt on a different CPU...
 728          */
 729         if (!console_subchannel_in_use)
 730                 return;
 731
 732         /* disable all but the console isc */
 733         __ctl_store (save_cr6, 6, 6);
 734         cr6 = 1UL << (31 - CONSOLE_ISC);
 735         __ctl_load (cr6, 6, 6);
 736
 737         do {
 738                 spin_unlock(console_subchannel.lock);
 739                 if (!cio_tpi())
 740                         cpu_relax();
 741                 spin_lock(console_subchannel.lock);
 742         } while (console_subchannel.schib.scsw.cmd.actl != 0);
 743         /*
 744          * restore previous isc value
 745          */
 746         __ctl_load (save_cr6, 6, 6);
 747 }
 748
 749 static int
 750 cio_test_for_console(struct subchannel_id schid, void *data)
 751 {
 752         if (stsch_err(schid, &console_subchannel.schib) != 0)
 753                 return -ENXIO;
 754         if ((console_subchannel.schib.pmcw.st == SUBCHANNEL_TYPE_IO) &&
 755             console_subchannel.schib.pmcw.dnv &&
 756             (console_subchannel.schib.pmcw.dev == console_devno)) {
 757                 console_irq = schid.sch_no;
 758                 return 1; /* found */
 759         }
 760         return 0;
 761 }
 762
 763
 764 static int
 765 cio_get_console_sch_no(void)
 766 {
 767         struct subchannel_id schid;
 768
 769         init_subchannel_id(&schid);
 770         if (console_irq != -1) {
 771                 /* VM provided us with the irq number of the console. */
 772                 schid.sch_no = console_irq;
 773                 if (stsch(schid, &console_subchannel.schib) != 0 ||
 774                     (console_subchannel.schib.pmcw.st != SUBCHANNEL_TYPE_IO) ||
 775                     !console_subchannel.schib.pmcw.dnv)
 776                         return -1;
 777                 console_devno = console_subchannel.schib.pmcw.dev;
 778         } else if (console_devno != -1) {
 779                 /* At least the console device number is known. */
 780                 for_each_subchannel(cio_test_for_console, NULL);
 781                 if (console_irq == -1)
 782                         return -1;
 783         } else {
 784                 /* unlike in 2.4, we cannot autoprobe here, since
 785                  * the channel subsystem is not fully initialized.
 786                  * With some luck, the HWC console can take over */
 787                 return -1;
 788         }
 789         return console_irq;
 790 }
 791
 792 struct subchannel *
 793 cio_probe_console(void)
 794 {
 795         int sch_no, ret;
 796         struct subchannel_id schid;
 797
 798         if (xchg(&console_subchannel_in_use, 1) != 0)
 799                 return ERR_PTR(-EBUSY);
 800         sch_no = cio_get_console_sch_no();
 801         if (sch_no == -1) {
 802                 console_subchannel_in_use = 0;
 803                 pr_warning("No CCW console was found\n");
 804                 return ERR_PTR(-ENODEV);
 805         }
 806         memset(&console_subchannel, 0, sizeof(struct subchannel));
 807         init_subchannel_id(&schid);
 808         schid.sch_no = sch_no;
 809         ret = cio_validate_subchannel(&console_subchannel, schid);
 810         if (ret) {
 811                 console_subchannel_in_use = 0;
 812                 return ERR_PTR(-ENODEV);
 813         }
 814
 815         /*
 816          * enable console I/O-interrupt subclass
 817          */
 818         isc_register(CONSOLE_ISC);
 819         console_subchannel.config.isc = CONSOLE_ISC;
 820         console_subchannel.config.intparm = (u32)(addr_t)&console_subchannel;
 821         ret = cio_commit_config(&console_subchannel);
 822         if (ret) {
 823                 isc_unregister(CONSOLE_ISC);
 824                 console_subchannel_in_use = 0;
 825                 return ERR_PTR(ret);
 826         }
 827         return &console_subchannel;
 828 }
 829
 830 void
 831 cio_release_console(void)
 832 {
 833         console_subchannel.config.intparm = 0;
 834         cio_commit_config(&console_subchannel);
 835         isc_unregister(CONSOLE_ISC);
 836         console_subchannel_in_use = 0;
 837 }
 838
 839 /* Bah... hack to catch console special sausages. */
 840 int
 841 cio_is_console(struct subchannel_id schid)
 842 {
 843         if (!console_subchannel_in_use)
 844                 return 0;
 845         return schid_equal(&schid, &console_subchannel.schid);
 846 }
 847
 848 struct subchannel *
 849 cio_get_console_subchannel(void)
 850 {
 851         if (!console_subchannel_in_use)
 852                 return NULL;
 853         return &console_subchannel;
 854 }
 855
 856 #endif
 857 static int
 858 __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
 859 {
 860         int retry, cc;
 861
 862         cc = 0;
 863         for (retry=0;retry<3;retry++) {
 864                 schib->pmcw.ena = 0;
 865                 cc = msch(schid, schib);
 866                 if (cc)
 867                         return (cc==3?-ENODEV:-EBUSY);
 868                 if (stsch(schid, schib) || !css_sch_is_valid(schib))
 869                         return -ENODEV;
 870                 if (!schib->pmcw.ena)
 871                         return 0;
 872         }
 873         return -EBUSY; /* uhm... */
 874 }
 875
 876 static int
 877 __clear_io_subchannel_easy(struct subchannel_id schid)
 878 {
 879         int retry;
 880
 881         if (csch(schid))
 882                 return -ENODEV;
 883         for (retry=0;retry<20;retry++) {
 884                 struct tpi_info ti;
 885
 886                 if (tpi(&ti)) {
 887                         tsch(ti.schid, (struct irb *)__LC_IRB);
 888                         if (schid_equal(&ti.schid, &schid))
 889                                 return 0;
 890                 }
 891                 udelay_simple(100);
 892         }
 893         return -EBUSY;
 894 }
 895
 896 static void __clear_chsc_subchannel_easy(void)
 897 {
 898         /* It seems we can only wait for a bit here :/ */
 899         udelay_simple(100);
 900 }
 901
 902 static int pgm_check_occured;
 903
 904 static void cio_reset_pgm_check_handler(void)
 905 {
 906         pgm_check_occured = 1;
 907 }
 908
 909 static int stsch_reset(struct subchannel_id schid, struct schib *addr)
 910 {
 911         int rc;
 912
 913         pgm_check_occured = 0;
 914         s390_base_pgm_handler_fn = cio_reset_pgm_check_handler;
 915         rc = stsch(schid, addr);
 916         s390_base_pgm_handler_fn = NULL;
 917
 918         /* The program check handler could have changed pgm_check_occured. */
 919         barrier();
 920
 921         if (pgm_check_occured)
 922                 return -EIO;
 923         else
 924                 return rc;
 925 }
 926
 927 static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
 928 {
 929         struct schib schib;
 930
 931         if (stsch_reset(schid, &schib))
 932                 return -ENXIO;
 933         if (!schib.pmcw.ena)
 934                 return 0;
 935         switch(__disable_subchannel_easy(schid, &schib)) {
 936         case 0:
 937         case -ENODEV:
 938                 break;
 939         default: /* -EBUSY */
 940                 switch (schib.pmcw.st) {
 941                 case SUBCHANNEL_TYPE_IO:
 942                         if (__clear_io_subchannel_easy(schid))
 943                                 goto out; /* give up... */
 944                         break;
 945                 case SUBCHANNEL_TYPE_CHSC:
 946                         __clear_chsc_subchannel_easy();
 947                         break;
 948                 default:
 949                         /* No default clear strategy */
 950                         break;
 951                 }
 952                 stsch(schid, &schib);
 953                 __disable_subchannel_easy(schid, &schib);
 954         }
 955 out:
 956         return 0;
 957 }
 958
 959 static atomic_t chpid_reset_count;
 960
 961 static void s390_reset_chpids_mcck_handler(void)
 962 {
 963         struct crw crw;
 964         struct mci *mci;
 965
 966         /* Check for pending channel report word. */
 967         mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
 968         if (!mci->cp)
 969                 return;
 970         /* Process channel report words. */
 971         while (stcrw(&crw) == 0) {
 972                 /* Check for responses to RCHP. */
 973                 if (crw.slct && crw.rsc == CRW_RSC_CPATH)
 974                         atomic_dec(&chpid_reset_count);
 975         }
 976 }
 977
 978 #define RCHP_TIMEOUT (30 * USEC_PER_SEC)
 979 static void css_reset(void)
 980 {
 981         int i, ret;
 982         unsigned long long timeout;
 983         struct chp_id chpid;
 984
 985         /* Reset subchannels. */
 986         for_each_subchannel(__shutdown_subchannel_easy,  NULL);
 987         /* Reset channel paths. */
 988         s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler;
 989         /* Enable channel report machine checks. */
 990         __ctl_set_bit(14, 28);
 991         /* Temporarily reenable machine checks. */
 992         local_mcck_enable();
 993         chp_id_init(&chpid);
 994         for (i = 0; i <= __MAX_CHPID; i++) {
 995                 chpid.id = i;
 996                 ret = rchp(chpid);
 997                 if ((ret == 0) || (ret == 2))
 998                         /*
 999                          * rchp either succeeded, or another rchp is already
1000                          * in progress. In either case, we'll get a crw.
1001                          */
1002                         atomic_inc(&chpid_reset_count);
1003         }
1004         /* Wait for machine check for all channel paths. */
1005         timeout = get_clock() + (RCHP_TIMEOUT << 12);
1006         while (atomic_read(&chpid_reset_count) != 0) {
1007                 if (get_clock() > timeout)
1008                         break;
1009                 cpu_relax();
1010         }
1011         /* Disable machine checks again. */
1012         local_mcck_disable();
1013         /* Disable channel report machine checks. */
1014         __ctl_clear_bit(14, 28);
1015         s390_base_mcck_handler_fn = NULL;
1016 }
1017
1018 static struct reset_call css_reset_call = {
1019         .fn = css_reset,
1020 };
1021
1022 static int __init init_css_reset_call(void)
1023 {
1024         atomic_set(&chpid_reset_count, 0);
1025         register_reset_call(&css_reset_call);
1026         return 0;
1027 }
1028
1029 arch_initcall(init_css_reset_call);
1030
1031 struct sch_match_id {
1032         struct subchannel_id schid;
1033         struct ccw_dev_id devid;
1034         int rc;
1035 };
1036
1037 static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
1038 {
1039         struct schib schib;
1040         struct sch_match_id *match_id = data;
1041
1042         if (stsch_reset(schid, &schib))
1043                 return -ENXIO;
1044         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
1045             (schib.pmcw.dev == match_id->devid.devno) &&
1046             (schid.ssid == match_id->devid.ssid)) {
1047                 match_id->schid = schid;
1048                 match_id->rc = 0;
1049                 return 1;
1050         }
1051         return 0;
1052 }
1053
1054 static int reipl_find_schid(struct ccw_dev_id *devid,
1055                             struct subchannel_id *schid)
1056 {
1057         struct sch_match_id match_id;
1058
1059         match_id.devid = *devid;
1060         match_id.rc = -ENODEV;
1061         for_each_subchannel(__reipl_subchannel_match, &match_id);
1062         if (match_id.rc == 0)
1063                 *schid = match_id.schid;
1064         return match_id.rc;
1065 }
1066
1067 extern void do_reipl_asm(__u32 schid);
1068
1069 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
1070 void reipl_ccw_dev(struct ccw_dev_id *devid)
1071 {
1072         struct subchannel_id schid;
1073
1074         s390_reset_system();
1075         if (reipl_find_schid(devid, &schid) != 0)
1076                 panic("IPL Device not found\n");
1077         do_reipl_asm(*((__u32*)&schid));
1078 }
1079
1080 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
1081 {
1082         struct subchannel_id schid;
1083         struct schib schib;
1084
1085         schid = *(struct subchannel_id *)__LC_SUBCHANNEL_ID;
1086         if (!schid.one)
1087                 return -ENODEV;
1088         if (stsch(schid, &schib))
1089                 return -ENODEV;
1090         if (schib.pmcw.st != SUBCHANNEL_TYPE_IO)
1091                 return -ENODEV;
1092         if (!schib.pmcw.dnv)
1093                 return -ENODEV;
1094         iplinfo->devno = schib.pmcw.dev;
1095         iplinfo->is_qdio = schib.pmcw.qf;
1096         return 0;
1097 }
1098
1099 /**
1100  * cio_tm_start_key - perform start function
1101  * @sch: subchannel on which to perform the start function
1102  * @tcw: transport-command word to be started
1103  * @lpm: mask of paths to use
1104  * @key: storage key to use for storage access
1105  *
1106  * Start the tcw on the given subchannel. Return zero on success, non-zero
1107  * otherwise.
1108  */
1109 int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
1110 {
1111         int cc;
1112         union orb *orb = &to_io_private(sch)->orb;
1113
1114         memset(orb, 0, sizeof(union orb));
1115         orb->tm.intparm = (u32) (addr_t) sch;
1116         orb->tm.key = key >> 4;
1117         orb->tm.b = 1;
1118         orb->tm.lpm = lpm ? lpm : sch->lpm;
1119         orb->tm.tcw = (u32) (addr_t) tcw;
1120         cc = ssch(sch->schid, orb);
1121         switch (cc) {
1122         case 0:
1123                 return 0;
1124         case 1:
1125         case 2:
1126                 return -EBUSY;
1127         default:
1128                 return cio_start_handle_notoper(sch, lpm);
1129         }
1130 }
1131
1132 /**
1133  * cio_tm_intrg - perform interrogate function
1134  * @sch - subchannel on which to perform the interrogate function
1135  *
1136  * If the specified subchannel is running in transport-mode, perform the
1137  * interrogate function. Return zero on success, non-zero otherwie.
1138  */
1139 int cio_tm_intrg(struct subchannel *sch)
1140 {
1141         int cc;
1142
1143         if (!to_io_private(sch)->orb.tm.b)
1144                 return -EINVAL;
1145         cc = xsch(sch->schid);
1146         switch (cc) {
1147         case 0:
1148         case 2:
1149                 return 0;
1150         case 1:
1151                 return -EBUSY;
1152         default:
1153                 return -ENODEV;
1154         }
1155 }