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 <linux/irq.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 <linux/sched/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 #include "trace.h"
  45
  46 debug_info_t *cio_debug_msg_id;
  47 debug_info_t *cio_debug_trace_id;
  48 debug_info_t *cio_debug_crw_id;
  49
  50 DEFINE_PER_CPU_ALIGNED(struct irb, cio_irb);
  51 EXPORT_PER_CPU_SYMBOL(cio_irb);
  52
  53 /*
  54  * Function: cio_debug_init
  55  * Initializes three debug logs for common I/O:
  56  * - cio_msg logs generic cio messages
  57  * - cio_trace logs the calling of different functions
  58  * - cio_crw logs machine check related cio messages
  59  */
  60 static int __init cio_debug_init(void)
  61 {
  62         cio_debug_msg_id = debug_register("cio_msg", 16, 1, 11 * sizeof(long));
  63         if (!cio_debug_msg_id)
  64                 goto out_unregister;
  65         debug_register_view(cio_debug_msg_id, &debug_sprintf_view);
  66         debug_set_level(cio_debug_msg_id, 2);
  67         cio_debug_trace_id = debug_register("cio_trace", 16, 1, 16);
  68         if (!cio_debug_trace_id)
  69                 goto out_unregister;
  70         debug_register_view(cio_debug_trace_id, &debug_hex_ascii_view);
  71         debug_set_level(cio_debug_trace_id, 2);
  72         cio_debug_crw_id = debug_register("cio_crw", 8, 1, 8 * sizeof(long));
  73         if (!cio_debug_crw_id)
  74                 goto out_unregister;
  75         debug_register_view(cio_debug_crw_id, &debug_sprintf_view);
  76         debug_set_level(cio_debug_crw_id, 4);
  77         return 0;
  78
  79 out_unregister:
  80         debug_unregister(cio_debug_msg_id);
  81         debug_unregister(cio_debug_trace_id);
  82         debug_unregister(cio_debug_crw_id);
  83         return -1;
  84 }
  85
  86 arch_initcall (cio_debug_init);
  87
  88 int cio_set_options(struct subchannel *sch, int flags)
  89 {
  90         struct io_subchannel_private *priv = to_io_private(sch);
  91
  92         priv->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
  93         priv->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
  94         priv->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
  95         return 0;
  96 }
  97
  98 static int
  99 cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
 100 {
 101         char dbf_text[15];
 102
 103         if (lpm != 0)
 104                 sch->lpm &= ~lpm;
 105         else
 106                 sch->lpm = 0;
 107
 108         CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
 109                       "subchannel 0.%x.%04x!\n", sch->schid.ssid,
 110                       sch->schid.sch_no);
 111
 112         if (cio_update_schib(sch))
 113                 return -ENODEV;
 114
 115         sprintf(dbf_text, "no%s", dev_name(&sch->dev));
 116         CIO_TRACE_EVENT(0, dbf_text);
 117         CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
 118
 119         return (sch->lpm ? -EACCES : -ENODEV);
 120 }
 121
 122 int
 123 cio_start_key (struct subchannel *sch,  /* subchannel structure */
 124                struct ccw1 * cpa,       /* logical channel prog addr */
 125                __u8 lpm,                /* logical path mask */
 126                __u8 key)                /* storage key */
 127 {
 128         struct io_subchannel_private *priv = to_io_private(sch);
 129         union orb *orb = &priv->orb;
 130         int ccode;
 131
 132         CIO_TRACE_EVENT(5, "stIO");
 133         CIO_TRACE_EVENT(5, dev_name(&sch->dev));
 134
 135         memset(orb, 0, sizeof(union orb));
 136         /* sch is always under 2G. */
 137         orb->cmd.intparm = (u32)(addr_t)sch;
 138         orb->cmd.fmt = 1;
 139
 140         orb->cmd.pfch = priv->options.prefetch == 0;
 141         orb->cmd.spnd = priv->options.suspend;
 142         orb->cmd.ssic = priv->options.suspend && priv->options.inter;
 143         orb->cmd.lpm = (lpm != 0) ? lpm : sch->lpm;
 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         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         int ccode, retry, ret = 0;
 346         struct schib schib;
 347         struct irb irb;
 348
 349         if (stsch(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(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(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                         ret = -EBUSY;
 372                         if (tsch(sch->schid, &irb))
 373                                 return ret;
 374                         break;
 375                 case 2: /* busy */
 376                         udelay(100); /* allow for recovery */
 377                         ret = -EBUSY;
 378                         break;
 379                 case 3: /* not operational */
 380                         return -ENODEV;
 381                 }
 382         }
 383         return ret;
 384 }
 385
 386 /**
 387  * cio_update_schib - Perform stsch and update schib if subchannel is valid.
 388  * @sch: subchannel on which to perform stsch
 389  * Return zero on success, -ENODEV otherwise.
 390  */
 391 int cio_update_schib(struct subchannel *sch)
 392 {
 393         struct schib schib;
 394
 395         if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
 396                 return -ENODEV;
 397
 398         memcpy(&sch->schib, &schib, sizeof(schib));
 399         return 0;
 400 }
 401 EXPORT_SYMBOL_GPL(cio_update_schib);
 402
 403 /**
 404  * cio_enable_subchannel - enable a subchannel.
 405  * @sch: subchannel to be enabled
 406  * @intparm: interruption parameter to set
 407  */
 408 int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
 409 {
 410         int ret;
 411
 412         CIO_TRACE_EVENT(2, "ensch");
 413         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 414
 415         if (sch_is_pseudo_sch(sch))
 416                 return -EINVAL;
 417         if (cio_update_schib(sch))
 418                 return -ENODEV;
 419
 420         sch->config.ena = 1;
 421         sch->config.isc = sch->isc;
 422         sch->config.intparm = intparm;
 423
 424         ret = cio_commit_config(sch);
 425         if (ret == -EIO) {
 426                 /*
 427                  * Got a program check in msch. Try without
 428                  * the concurrent sense bit the next time.
 429                  */
 430                 sch->config.csense = 0;
 431                 ret = cio_commit_config(sch);
 432         }
 433         CIO_HEX_EVENT(2, &ret, sizeof(ret));
 434         return ret;
 435 }
 436 EXPORT_SYMBOL_GPL(cio_enable_subchannel);
 437
 438 /**
 439  * cio_disable_subchannel - disable a subchannel.
 440  * @sch: subchannel to disable
 441  */
 442 int cio_disable_subchannel(struct subchannel *sch)
 443 {
 444         int ret;
 445
 446         CIO_TRACE_EVENT(2, "dissch");
 447         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 448
 449         if (sch_is_pseudo_sch(sch))
 450                 return 0;
 451         if (cio_update_schib(sch))
 452                 return -ENODEV;
 453
 454         sch->config.ena = 0;
 455         ret = cio_commit_config(sch);
 456
 457         CIO_HEX_EVENT(2, &ret, sizeof(ret));
 458         return ret;
 459 }
 460 EXPORT_SYMBOL_GPL(cio_disable_subchannel);
 461
 462 static int cio_check_devno_blacklisted(struct subchannel *sch)
 463 {
 464         if (is_blacklisted(sch->schid.ssid, sch->schib.pmcw.dev)) {
 465                 /*
 466                  * This device must not be known to Linux. So we simply
 467                  * say that there is no device and return ENODEV.
 468                  */
 469                 CIO_MSG_EVENT(6, "Blacklisted device detected "
 470                               "at devno %04X, subchannel set %x\n",
 471                               sch->schib.pmcw.dev, sch->schid.ssid);
 472                 return -ENODEV;
 473         }
 474         return 0;
 475 }
 476
 477 /**
 478  * cio_validate_subchannel - basic validation of subchannel
 479  * @sch: subchannel structure to be filled out
 480  * @schid: subchannel id
 481  *
 482  * Find out subchannel type and initialize struct subchannel.
 483  * Return codes:
 484  *   0 on success
 485  *   -ENXIO for non-defined subchannels
 486  *   -ENODEV for invalid subchannels or blacklisted devices
 487  *   -EIO for subchannels in an invalid subchannel set
 488  */
 489 int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
 490 {
 491         char dbf_txt[15];
 492         int ccode;
 493         int err;
 494
 495         sprintf(dbf_txt, "valsch%x", schid.sch_no);
 496         CIO_TRACE_EVENT(4, dbf_txt);
 497
 498         /*
 499          * The first subchannel that is not-operational (ccode==3)
 500          * indicates that there aren't any more devices available.
 501          * If stsch gets an exception, it means the current subchannel set
 502          * is not valid.
 503          */
 504         ccode = stsch(schid, &sch->schib);
 505         if (ccode) {
 506                 err = (ccode == 3) ? -ENXIO : ccode;
 507                 goto out;
 508         }
 509         sch->st = sch->schib.pmcw.st;
 510         sch->schid = schid;
 511
 512         switch (sch->st) {
 513         case SUBCHANNEL_TYPE_IO:
 514         case SUBCHANNEL_TYPE_MSG:
 515                 if (!css_sch_is_valid(&sch->schib))
 516                         err = -ENODEV;
 517                 else
 518                         err = cio_check_devno_blacklisted(sch);
 519                 break;
 520         default:
 521                 err = 0;
 522         }
 523         if (err)
 524                 goto out;
 525
 526         CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
 527                       sch->schid.ssid, sch->schid.sch_no, sch->st);
 528 out:
 529         return err;
 530 }
 531
 532 /*
 533  * do_cio_interrupt() handles all normal I/O device IRQ's
 534  */
 535 static irqreturn_t do_cio_interrupt(int irq, void *dummy)
 536 {
 537         struct tpi_info *tpi_info;
 538         struct subchannel *sch;
 539         struct irb *irb;
 540
 541         set_cpu_flag(CIF_NOHZ_DELAY);
 542         tpi_info = (struct tpi_info *) &get_irq_regs()->int_code;
 543         trace_s390_cio_interrupt(tpi_info);
 544         irb = this_cpu_ptr(&cio_irb);
 545         sch = (struct subchannel *)(unsigned long) tpi_info->intparm;
 546         if (!sch) {
 547                 /* Clear pending interrupt condition. */
 548                 inc_irq_stat(IRQIO_CIO);
 549                 tsch(tpi_info->schid, irb);
 550                 return IRQ_HANDLED;
 551         }
 552         spin_lock(sch->lock);
 553         /* Store interrupt response block to lowcore. */
 554         if (tsch(tpi_info->schid, irb) == 0) {
 555                 /* Keep subchannel information word up to date. */
 556                 memcpy (&sch->schib.scsw, &irb->scsw, sizeof (irb->scsw));
 557                 /* Call interrupt handler if there is one. */
 558                 if (sch->driver && sch->driver->irq)
 559                         sch->driver->irq(sch);
 560                 else
 561                         inc_irq_stat(IRQIO_CIO);
 562         } else
 563                 inc_irq_stat(IRQIO_CIO);
 564         spin_unlock(sch->lock);
 565
 566         return IRQ_HANDLED;
 567 }
 568
 569 static struct irqaction io_interrupt = {
 570         .name    = "IO",
 571         .handler = do_cio_interrupt,
 572 };
 573
 574 void __init init_cio_interrupts(void)
 575 {
 576         irq_set_chip_and_handler(IO_INTERRUPT,
 577                                  &dummy_irq_chip, handle_percpu_irq);
 578         setup_irq(IO_INTERRUPT, &io_interrupt);
 579 }
 580
 581 #ifdef CONFIG_CCW_CONSOLE
 582 static struct subchannel *console_sch;
 583 static struct lock_class_key console_sch_key;
 584
 585 /*
 586  * Use cio_tsch to update the subchannel status and call the interrupt handler
 587  * if status had been pending. Called with the subchannel's lock held.
 588  */
 589 void cio_tsch(struct subchannel *sch)
 590 {
 591         struct irb *irb;
 592         int irq_context;
 593
 594         irb = this_cpu_ptr(&cio_irb);
 595         /* Store interrupt response block to lowcore. */
 596         if (tsch(sch->schid, irb) != 0)
 597                 /* Not status pending or not operational. */
 598                 return;
 599         memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
 600         /* Call interrupt handler with updated status. */
 601         irq_context = in_interrupt();
 602         if (!irq_context) {
 603                 local_bh_disable();
 604                 irq_enter();
 605         }
 606         kstat_incr_irq_this_cpu(IO_INTERRUPT);
 607         if (sch->driver && sch->driver->irq)
 608                 sch->driver->irq(sch);
 609         else
 610                 inc_irq_stat(IRQIO_CIO);
 611         if (!irq_context) {
 612                 irq_exit();
 613                 _local_bh_enable();
 614         }
 615 }
 616
 617 static int cio_test_for_console(struct subchannel_id schid, void *data)
 618 {
 619         struct schib schib;
 620
 621         if (stsch(schid, &schib) != 0)
 622                 return -ENXIO;
 623         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
 624             (schib.pmcw.dev == console_devno)) {
 625                 console_irq = schid.sch_no;
 626                 return 1; /* found */
 627         }
 628         return 0;
 629 }
 630
 631 static int cio_get_console_sch_no(void)
 632 {
 633         struct subchannel_id schid;
 634         struct schib schib;
 635
 636         init_subchannel_id(&schid);
 637         if (console_irq != -1) {
 638                 /* VM provided us with the irq number of the console. */
 639                 schid.sch_no = console_irq;
 640                 if (stsch(schid, &schib) != 0 ||
 641                     (schib.pmcw.st != SUBCHANNEL_TYPE_IO) || !schib.pmcw.dnv)
 642                         return -1;
 643                 console_devno = schib.pmcw.dev;
 644         } else if (console_devno != -1) {
 645                 /* At least the console device number is known. */
 646                 for_each_subchannel(cio_test_for_console, NULL);
 647         }
 648         return console_irq;
 649 }
 650
 651 struct subchannel *cio_probe_console(void)
 652 {
 653         struct subchannel_id schid;
 654         struct subchannel *sch;
 655         int sch_no, ret;
 656
 657         sch_no = cio_get_console_sch_no();
 658         if (sch_no == -1) {
 659                 pr_warn("No CCW console was found\n");
 660                 return ERR_PTR(-ENODEV);
 661         }
 662         init_subchannel_id(&schid);
 663         schid.sch_no = sch_no;
 664         sch = css_alloc_subchannel(schid);
 665         if (IS_ERR(sch))
 666                 return sch;
 667
 668         lockdep_set_class(sch->lock, &console_sch_key);
 669         isc_register(CONSOLE_ISC);
 670         sch->config.isc = CONSOLE_ISC;
 671         sch->config.intparm = (u32)(addr_t)sch;
 672         ret = cio_commit_config(sch);
 673         if (ret) {
 674                 isc_unregister(CONSOLE_ISC);
 675                 put_device(&sch->dev);
 676                 return ERR_PTR(ret);
 677         }
 678         console_sch = sch;
 679         return sch;
 680 }
 681
 682 int cio_is_console(struct subchannel_id schid)
 683 {
 684         if (!console_sch)
 685                 return 0;
 686         return schid_equal(&schid, &console_sch->schid);
 687 }
 688
 689 void cio_register_early_subchannels(void)
 690 {
 691         int ret;
 692
 693         if (!console_sch)
 694                 return;
 695
 696         ret = css_register_subchannel(console_sch);
 697         if (ret)
 698                 put_device(&console_sch->dev);
 699 }
 700 #endif /* CONFIG_CCW_CONSOLE */
 701
 702 static int
 703 __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
 704 {
 705         int retry, cc;
 706
 707         cc = 0;
 708         for (retry=0;retry<3;retry++) {
 709                 schib->pmcw.ena = 0;
 710                 cc = msch(schid, schib);
 711                 if (cc)
 712                         return (cc==3?-ENODEV:-EBUSY);
 713                 if (stsch(schid, schib) || !css_sch_is_valid(schib))
 714                         return -ENODEV;
 715                 if (!schib->pmcw.ena)
 716                         return 0;
 717         }
 718         return -EBUSY; /* uhm... */
 719 }
 720
 721 static int
 722 __clear_io_subchannel_easy(struct subchannel_id schid)
 723 {
 724         int retry;
 725
 726         if (csch(schid))
 727                 return -ENODEV;
 728         for (retry=0;retry<20;retry++) {
 729                 struct tpi_info ti;
 730
 731                 if (tpi(&ti)) {
 732                         tsch(ti.schid, this_cpu_ptr(&cio_irb));
 733                         if (schid_equal(&ti.schid, &schid))
 734                                 return 0;
 735                 }
 736                 udelay_simple(100);
 737         }
 738         return -EBUSY;
 739 }
 740
 741 static void __clear_chsc_subchannel_easy(void)
 742 {
 743         /* It seems we can only wait for a bit here :/ */
 744         udelay_simple(100);
 745 }
 746
 747 static int pgm_check_occured;
 748
 749 static void cio_reset_pgm_check_handler(void)
 750 {
 751         pgm_check_occured = 1;
 752 }
 753
 754 static int stsch_reset(struct subchannel_id schid, struct schib *addr)
 755 {
 756         int rc;
 757
 758         pgm_check_occured = 0;
 759         s390_base_pgm_handler_fn = cio_reset_pgm_check_handler;
 760         rc = stsch(schid, addr);
 761         s390_base_pgm_handler_fn = NULL;
 762
 763         /* The program check handler could have changed pgm_check_occured. */
 764         barrier();
 765
 766         if (pgm_check_occured)
 767                 return -EIO;
 768         else
 769                 return rc;
 770 }
 771
 772 static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
 773 {
 774         struct schib schib;
 775
 776         if (stsch_reset(schid, &schib))
 777                 return -ENXIO;
 778         if (!schib.pmcw.ena)
 779                 return 0;
 780         switch(__disable_subchannel_easy(schid, &schib)) {
 781         case 0:
 782         case -ENODEV:
 783                 break;
 784         default: /* -EBUSY */
 785                 switch (schib.pmcw.st) {
 786                 case SUBCHANNEL_TYPE_IO:
 787                         if (__clear_io_subchannel_easy(schid))
 788                                 goto out; /* give up... */
 789                         break;
 790                 case SUBCHANNEL_TYPE_CHSC:
 791                         __clear_chsc_subchannel_easy();
 792                         break;
 793                 default:
 794                         /* No default clear strategy */
 795                         break;
 796                 }
 797                 stsch(schid, &schib);
 798                 __disable_subchannel_easy(schid, &schib);
 799         }
 800 out:
 801         return 0;
 802 }
 803
 804 static atomic_t chpid_reset_count;
 805
 806 static void s390_reset_chpids_mcck_handler(void)
 807 {
 808         struct crw crw;
 809         union mci mci;
 810
 811         /* Check for pending channel report word. */
 812         mci.val = S390_lowcore.mcck_interruption_code;
 813         if (!mci.cp)
 814                 return;
 815         /* Process channel report words. */
 816         while (stcrw(&crw) == 0) {
 817                 /* Check for responses to RCHP. */
 818                 if (crw.slct && crw.rsc == CRW_RSC_CPATH)
 819                         atomic_dec(&chpid_reset_count);
 820         }
 821 }
 822
 823 #define RCHP_TIMEOUT (30 * USEC_PER_SEC)
 824 static void css_reset(void)
 825 {
 826         int i, ret;
 827         unsigned long long timeout;
 828         struct chp_id chpid;
 829
 830         /* Reset subchannels. */
 831         for_each_subchannel(__shutdown_subchannel_easy,  NULL);
 832         /* Reset channel paths. */
 833         s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler;
 834         /* Enable channel report machine checks. */
 835         __ctl_set_bit(14, 28);
 836         /* Temporarily reenable machine checks. */
 837         local_mcck_enable();
 838         chp_id_init(&chpid);
 839         for (i = 0; i <= __MAX_CHPID; i++) {
 840                 chpid.id = i;
 841                 ret = rchp(chpid);
 842                 if ((ret == 0) || (ret == 2))
 843                         /*
 844                          * rchp either succeeded, or another rchp is already
 845                          * in progress. In either case, we'll get a crw.
 846                          */
 847                         atomic_inc(&chpid_reset_count);
 848         }
 849         /* Wait for machine check for all channel paths. */
 850         timeout = get_tod_clock_fast() + (RCHP_TIMEOUT << 12);
 851         while (atomic_read(&chpid_reset_count) != 0) {
 852                 if (get_tod_clock_fast() > timeout)
 853                         break;
 854                 cpu_relax();
 855         }
 856         /* Disable machine checks again. */
 857         local_mcck_disable();
 858         /* Disable channel report machine checks. */
 859         __ctl_clear_bit(14, 28);
 860         s390_base_mcck_handler_fn = NULL;
 861 }
 862
 863 static struct reset_call css_reset_call = {
 864         .fn = css_reset,
 865 };
 866
 867 static int __init init_css_reset_call(void)
 868 {
 869         atomic_set(&chpid_reset_count, 0);
 870         register_reset_call(&css_reset_call);
 871         return 0;
 872 }
 873
 874 arch_initcall(init_css_reset_call);
 875
 876 struct sch_match_id {
 877         struct subchannel_id schid;
 878         struct ccw_dev_id devid;
 879         int rc;
 880 };
 881
 882 static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
 883 {
 884         struct schib schib;
 885         struct sch_match_id *match_id = data;
 886
 887         if (stsch_reset(schid, &schib))
 888                 return -ENXIO;
 889         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
 890             (schib.pmcw.dev == match_id->devid.devno) &&
 891             (schid.ssid == match_id->devid.ssid)) {
 892                 match_id->schid = schid;
 893                 match_id->rc = 0;
 894                 return 1;
 895         }
 896         return 0;
 897 }
 898
 899 static int reipl_find_schid(struct ccw_dev_id *devid,
 900                             struct subchannel_id *schid)
 901 {
 902         struct sch_match_id match_id;
 903
 904         match_id.devid = *devid;
 905         match_id.rc = -ENODEV;
 906         for_each_subchannel(__reipl_subchannel_match, &match_id);
 907         if (match_id.rc == 0)
 908                 *schid = match_id.schid;
 909         return match_id.rc;
 910 }
 911
 912 extern void do_reipl_asm(__u32 schid);
 913
 914 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
 915 void reipl_ccw_dev(struct ccw_dev_id *devid)
 916 {
 917         struct subchannel_id uninitialized_var(schid);
 918
 919         s390_reset_system();
 920         if (reipl_find_schid(devid, &schid) != 0)
 921                 panic("IPL Device not found\n");
 922         do_reipl_asm(*((__u32*)&schid));
 923 }
 924
 925 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
 926 {
 927         static struct chsc_sda_area sda_area __initdata;
 928         struct subchannel_id schid;
 929         struct schib schib;
 930
 931         schid = *(struct subchannel_id *)&S390_lowcore.subchannel_id;
 932         if (!schid.one)
 933                 return -ENODEV;
 934
 935         if (schid.ssid) {
 936                 /*
 937                  * Firmware should have already enabled MSS but whoever started
 938                  * the kernel might have initiated a channel subsystem reset.
 939                  * Ensure that MSS is enabled.
 940                  */
 941                 memset(&sda_area, 0, sizeof(sda_area));
 942                 if (__chsc_enable_facility(&sda_area, CHSC_SDA_OC_MSS))
 943                         return -ENODEV;
 944         }
 945         if (stsch(schid, &schib))
 946                 return -ENODEV;
 947         if (schib.pmcw.st != SUBCHANNEL_TYPE_IO)
 948                 return -ENODEV;
 949         if (!schib.pmcw.dnv)
 950                 return -ENODEV;
 951
 952         iplinfo->ssid = schid.ssid;
 953         iplinfo->devno = schib.pmcw.dev;
 954         iplinfo->is_qdio = schib.pmcw.qf;
 955         return 0;
 956 }
 957
 958 /**
 959  * cio_tm_start_key - perform start function
 960  * @sch: subchannel on which to perform the start function
 961  * @tcw: transport-command word to be started
 962  * @lpm: mask of paths to use
 963  * @key: storage key to use for storage access
 964  *
 965  * Start the tcw on the given subchannel. Return zero on success, non-zero
 966  * otherwise.
 967  */
 968 int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
 969 {
 970         int cc;
 971         union orb *orb = &to_io_private(sch)->orb;
 972
 973         memset(orb, 0, sizeof(union orb));
 974         orb->tm.intparm = (u32) (addr_t) sch;
 975         orb->tm.key = key >> 4;
 976         orb->tm.b = 1;
 977         orb->tm.lpm = lpm ? lpm : sch->lpm;
 978         orb->tm.tcw = (u32) (addr_t) tcw;
 979         cc = ssch(sch->schid, orb);
 980         switch (cc) {
 981         case 0:
 982                 return 0;
 983         case 1:
 984         case 2:
 985                 return -EBUSY;
 986         default:
 987                 return cio_start_handle_notoper(sch, lpm);
 988         }
 989 }
 990
 991 /**
 992  * cio_tm_intrg - perform interrogate function
 993  * @sch - subchannel on which to perform the interrogate function
 994  *
 995  * If the specified subchannel is running in transport-mode, perform the
 996  * interrogate function. Return zero on success, non-zero otherwie.
 997  */
 998 int cio_tm_intrg(struct subchannel *sch)
 999 {
1000         int cc;
1001
1002         if (!to_io_private(sch)->orb.tm.b)
1003                 return -EINVAL;
1004         cc = xsch(sch->schid);
1005         switch (cc) {
1006         case 0:
1007         case 2:
1008                 return 0;
1009         case 1:
1010                 return -EBUSY;
1011         default:
1012                 return -ENODEV;
1013         }
1014 }