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/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, 11 * 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", 8, 1, 8 * 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         int ccode, retry, ret = 0;
 347         struct schib schib;
 348         struct irb irb;
 349
 350         if (stsch_err(sch->schid, &schib) || !css_sch_is_valid(&schib))
 351                 return -ENODEV;
 352
 353         for (retry = 0; retry < 5; retry++) {
 354                 /* copy desired changes to local schib */
 355                 cio_apply_config(sch, &schib);
 356                 ccode = msch_err(sch->schid, &schib);
 357                 if (ccode < 0) /* -EIO if msch gets a program check. */
 358                         return ccode;
 359                 switch (ccode) {
 360                 case 0: /* successful */
 361                         if (stsch_err(sch->schid, &schib) ||
 362                             !css_sch_is_valid(&schib))
 363                                 return -ENODEV;
 364                         if (cio_check_config(sch, &schib)) {
 365                                 /* commit changes from local schib */
 366                                 memcpy(&sch->schib, &schib, sizeof(schib));
 367                                 return 0;
 368                         }
 369                         ret = -EAGAIN;
 370                         break;
 371                 case 1: /* status pending */
 372                         ret = -EBUSY;
 373                         if (tsch(sch->schid, &irb))
 374                                 return ret;
 375                         break;
 376                 case 2: /* busy */
 377                         udelay(100); /* allow for recovery */
 378                         ret = -EBUSY;
 379                         break;
 380                 case 3: /* not operational */
 381                         return -ENODEV;
 382                 }
 383         }
 384         return ret;
 385 }
 386
 387 /**
 388  * cio_update_schib - Perform stsch and update schib if subchannel is valid.
 389  * @sch: subchannel on which to perform stsch
 390  * Return zero on success, -ENODEV otherwise.
 391  */
 392 int cio_update_schib(struct subchannel *sch)
 393 {
 394         struct schib schib;
 395
 396         if (stsch_err(sch->schid, &schib) || !css_sch_is_valid(&schib))
 397                 return -ENODEV;
 398
 399         memcpy(&sch->schib, &schib, sizeof(schib));
 400         return 0;
 401 }
 402 EXPORT_SYMBOL_GPL(cio_update_schib);
 403
 404 /**
 405  * cio_enable_subchannel - enable a subchannel.
 406  * @sch: subchannel to be enabled
 407  * @intparm: interruption parameter to set
 408  */
 409 int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
 410 {
 411         int ret;
 412
 413         CIO_TRACE_EVENT(2, "ensch");
 414         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 415
 416         if (sch_is_pseudo_sch(sch))
 417                 return -EINVAL;
 418         if (cio_update_schib(sch))
 419                 return -ENODEV;
 420
 421         sch->config.ena = 1;
 422         sch->config.isc = sch->isc;
 423         sch->config.intparm = intparm;
 424
 425         ret = cio_commit_config(sch);
 426         if (ret == -EIO) {
 427                 /*
 428                  * Got a program check in msch. Try without
 429                  * the concurrent sense bit the next time.
 430                  */
 431                 sch->config.csense = 0;
 432                 ret = cio_commit_config(sch);
 433         }
 434         CIO_HEX_EVENT(2, &ret, sizeof(ret));
 435         return ret;
 436 }
 437 EXPORT_SYMBOL_GPL(cio_enable_subchannel);
 438
 439 /**
 440  * cio_disable_subchannel - disable a subchannel.
 441  * @sch: subchannel to disable
 442  */
 443 int cio_disable_subchannel(struct subchannel *sch)
 444 {
 445         int ret;
 446
 447         CIO_TRACE_EVENT(2, "dissch");
 448         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 449
 450         if (sch_is_pseudo_sch(sch))
 451                 return 0;
 452         if (cio_update_schib(sch))
 453                 return -ENODEV;
 454
 455         sch->config.ena = 0;
 456         ret = cio_commit_config(sch);
 457
 458         CIO_HEX_EVENT(2, &ret, sizeof(ret));
 459         return ret;
 460 }
 461 EXPORT_SYMBOL_GPL(cio_disable_subchannel);
 462
 463 static int cio_check_devno_blacklisted(struct subchannel *sch)
 464 {
 465         if (is_blacklisted(sch->schid.ssid, sch->schib.pmcw.dev)) {
 466                 /*
 467                  * This device must not be known to Linux. So we simply
 468                  * say that there is no device and return ENODEV.
 469                  */
 470                 CIO_MSG_EVENT(6, "Blacklisted device detected "
 471                               "at devno %04X, subchannel set %x\n",
 472                               sch->schib.pmcw.dev, sch->schid.ssid);
 473                 return -ENODEV;
 474         }
 475         return 0;
 476 }
 477
 478 static int cio_validate_io_subchannel(struct subchannel *sch)
 479 {
 480         /* Initialization for io subchannels. */
 481         if (!css_sch_is_valid(&sch->schib))
 482                 return -ENODEV;
 483
 484         /* Devno is valid. */
 485         return cio_check_devno_blacklisted(sch);
 486 }
 487
 488 static int cio_validate_msg_subchannel(struct subchannel *sch)
 489 {
 490         /* Initialization for message subchannels. */
 491         if (!css_sch_is_valid(&sch->schib))
 492                 return -ENODEV;
 493
 494         /* Devno is valid. */
 495         return cio_check_devno_blacklisted(sch);
 496 }
 497
 498 /**
 499  * cio_validate_subchannel - basic validation of subchannel
 500  * @sch: subchannel structure to be filled out
 501  * @schid: subchannel id
 502  *
 503  * Find out subchannel type and initialize struct subchannel.
 504  * Return codes:
 505  *   0 on success
 506  *   -ENXIO for non-defined subchannels
 507  *   -ENODEV for invalid subchannels or blacklisted devices
 508  *   -EIO for subchannels in an invalid subchannel set
 509  */
 510 int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
 511 {
 512         char dbf_txt[15];
 513         int ccode;
 514         int err;
 515
 516         sprintf(dbf_txt, "valsch%x", schid.sch_no);
 517         CIO_TRACE_EVENT(4, dbf_txt);
 518
 519         /*
 520          * The first subchannel that is not-operational (ccode==3)
 521          * indicates that there aren't any more devices available.
 522          * If stsch gets an exception, it means the current subchannel set
 523          * is not valid.
 524          */
 525         ccode = stsch_err(schid, &sch->schib);
 526         if (ccode) {
 527                 err = (ccode == 3) ? -ENXIO : ccode;
 528                 goto out;
 529         }
 530         sch->st = sch->schib.pmcw.st;
 531         sch->schid = schid;
 532
 533         switch (sch->st) {
 534         case SUBCHANNEL_TYPE_IO:
 535                 err = cio_validate_io_subchannel(sch);
 536                 break;
 537         case SUBCHANNEL_TYPE_MSG:
 538                 err = cio_validate_msg_subchannel(sch);
 539                 break;
 540         default:
 541                 err = 0;
 542         }
 543         if (err)
 544                 goto out;
 545
 546         CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
 547                       sch->schid.ssid, sch->schid.sch_no, sch->st);
 548 out:
 549         return err;
 550 }
 551
 552 /*
 553  * do_cio_interrupt() handles all normal I/O device IRQ's
 554  */
 555 static irqreturn_t do_cio_interrupt(int irq, void *dummy)
 556 {
 557         struct tpi_info *tpi_info;
 558         struct subchannel *sch;
 559         struct irb *irb;
 560
 561         __this_cpu_write(s390_idle.nohz_delay, 1);
 562         tpi_info = (struct tpi_info *) &get_irq_regs()->int_code;
 563         irb = (struct irb *) &S390_lowcore.irb;
 564         sch = (struct subchannel *)(unsigned long) tpi_info->intparm;
 565         if (!sch) {
 566                 /* Clear pending interrupt condition. */
 567                 inc_irq_stat(IRQIO_CIO);
 568                 tsch(tpi_info->schid, irb);
 569                 return IRQ_HANDLED;
 570         }
 571         spin_lock(sch->lock);
 572         /* Store interrupt response block to lowcore. */
 573         if (tsch(tpi_info->schid, irb) == 0) {
 574                 /* Keep subchannel information word up to date. */
 575                 memcpy (&sch->schib.scsw, &irb->scsw, sizeof (irb->scsw));
 576                 /* Call interrupt handler if there is one. */
 577                 if (sch->driver && sch->driver->irq)
 578                         sch->driver->irq(sch);
 579                 else
 580                         inc_irq_stat(IRQIO_CIO);
 581         } else
 582                 inc_irq_stat(IRQIO_CIO);
 583         spin_unlock(sch->lock);
 584
 585         return IRQ_HANDLED;
 586 }
 587
 588 static struct irqaction io_interrupt = {
 589         .name    = "IO",
 590         .handler = do_cio_interrupt,
 591 };
 592
 593 void __init init_cio_interrupts(void)
 594 {
 595         irq_set_chip_and_handler(IO_INTERRUPT,
 596                                  &dummy_irq_chip, handle_percpu_irq);
 597         setup_irq(IO_INTERRUPT, &io_interrupt);
 598 }
 599
 600 #ifdef CONFIG_CCW_CONSOLE
 601 static struct subchannel *console_sch;
 602
 603 /*
 604  * Use cio_tsch to update the subchannel status and call the interrupt handler
 605  * if status had been pending. Called with the subchannel's lock held.
 606  */
 607 void cio_tsch(struct subchannel *sch)
 608 {
 609         struct irb *irb;
 610         int irq_context;
 611
 612         irb = (struct irb *)&S390_lowcore.irb;
 613         /* Store interrupt response block to lowcore. */
 614         if (tsch(sch->schid, irb) != 0)
 615                 /* Not status pending or not operational. */
 616                 return;
 617         memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
 618         /* Call interrupt handler with updated status. */
 619         irq_context = in_interrupt();
 620         if (!irq_context) {
 621                 local_bh_disable();
 622                 irq_enter();
 623         }
 624         kstat_incr_irq_this_cpu(IO_INTERRUPT);
 625         if (sch->driver && sch->driver->irq)
 626                 sch->driver->irq(sch);
 627         else
 628                 inc_irq_stat(IRQIO_CIO);
 629         if (!irq_context) {
 630                 irq_exit();
 631                 _local_bh_enable();
 632         }
 633 }
 634
 635 static int cio_test_for_console(struct subchannel_id schid, void *data)
 636 {
 637         struct schib schib;
 638
 639         if (stsch_err(schid, &schib) != 0)
 640                 return -ENXIO;
 641         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
 642             (schib.pmcw.dev == console_devno)) {
 643                 console_irq = schid.sch_no;
 644                 return 1; /* found */
 645         }
 646         return 0;
 647 }
 648
 649 static int cio_get_console_sch_no(void)
 650 {
 651         struct subchannel_id schid;
 652         struct schib schib;
 653
 654         init_subchannel_id(&schid);
 655         if (console_irq != -1) {
 656                 /* VM provided us with the irq number of the console. */
 657                 schid.sch_no = console_irq;
 658                 if (stsch_err(schid, &schib) != 0 ||
 659                     (schib.pmcw.st != SUBCHANNEL_TYPE_IO) || !schib.pmcw.dnv)
 660                         return -1;
 661                 console_devno = schib.pmcw.dev;
 662         } else if (console_devno != -1) {
 663                 /* At least the console device number is known. */
 664                 for_each_subchannel(cio_test_for_console, NULL);
 665         }
 666         return console_irq;
 667 }
 668
 669 struct subchannel *cio_probe_console(void)
 670 {
 671         struct subchannel_id schid;
 672         struct subchannel *sch;
 673         int sch_no, ret;
 674
 675         sch_no = cio_get_console_sch_no();
 676         if (sch_no == -1) {
 677                 pr_warning("No CCW console was found\n");
 678                 return ERR_PTR(-ENODEV);
 679         }
 680         init_subchannel_id(&schid);
 681         schid.sch_no = sch_no;
 682         sch = css_alloc_subchannel(schid);
 683         if (IS_ERR(sch))
 684                 return sch;
 685
 686         isc_register(CONSOLE_ISC);
 687         sch->config.isc = CONSOLE_ISC;
 688         sch->config.intparm = (u32)(addr_t)sch;
 689         ret = cio_commit_config(sch);
 690         if (ret) {
 691                 isc_unregister(CONSOLE_ISC);
 692                 put_device(&sch->dev);
 693                 return ERR_PTR(ret);
 694         }
 695         console_sch = sch;
 696         return sch;
 697 }
 698
 699 int cio_is_console(struct subchannel_id schid)
 700 {
 701         if (!console_sch)
 702                 return 0;
 703         return schid_equal(&schid, &console_sch->schid);
 704 }
 705
 706 void cio_register_early_subchannels(void)
 707 {
 708         int ret;
 709
 710         if (!console_sch)
 711                 return;
 712
 713         ret = css_register_subchannel(console_sch);
 714         if (ret)
 715                 put_device(&console_sch->dev);
 716 }
 717 #endif /* CONFIG_CCW_CONSOLE */
 718
 719 static int
 720 __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
 721 {
 722         int retry, cc;
 723
 724         cc = 0;
 725         for (retry=0;retry<3;retry++) {
 726                 schib->pmcw.ena = 0;
 727                 cc = msch_err(schid, schib);
 728                 if (cc)
 729                         return (cc==3?-ENODEV:-EBUSY);
 730                 if (stsch_err(schid, schib) || !css_sch_is_valid(schib))
 731                         return -ENODEV;
 732                 if (!schib->pmcw.ena)
 733                         return 0;
 734         }
 735         return -EBUSY; /* uhm... */
 736 }
 737
 738 static int
 739 __clear_io_subchannel_easy(struct subchannel_id schid)
 740 {
 741         int retry;
 742
 743         if (csch(schid))
 744                 return -ENODEV;
 745         for (retry=0;retry<20;retry++) {
 746                 struct tpi_info ti;
 747
 748                 if (tpi(&ti)) {
 749                         tsch(ti.schid, (struct irb *)&S390_lowcore.irb);
 750                         if (schid_equal(&ti.schid, &schid))
 751                                 return 0;
 752                 }
 753                 udelay_simple(100);
 754         }
 755         return -EBUSY;
 756 }
 757
 758 static void __clear_chsc_subchannel_easy(void)
 759 {
 760         /* It seems we can only wait for a bit here :/ */
 761         udelay_simple(100);
 762 }
 763
 764 static int pgm_check_occured;
 765
 766 static void cio_reset_pgm_check_handler(void)
 767 {
 768         pgm_check_occured = 1;
 769 }
 770
 771 static int stsch_reset(struct subchannel_id schid, struct schib *addr)
 772 {
 773         int rc;
 774
 775         pgm_check_occured = 0;
 776         s390_base_pgm_handler_fn = cio_reset_pgm_check_handler;
 777         rc = stsch_err(schid, addr);
 778         s390_base_pgm_handler_fn = NULL;
 779
 780         /* The program check handler could have changed pgm_check_occured. */
 781         barrier();
 782
 783         if (pgm_check_occured)
 784                 return -EIO;
 785         else
 786                 return rc;
 787 }
 788
 789 static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
 790 {
 791         struct schib schib;
 792
 793         if (stsch_reset(schid, &schib))
 794                 return -ENXIO;
 795         if (!schib.pmcw.ena)
 796                 return 0;
 797         switch(__disable_subchannel_easy(schid, &schib)) {
 798         case 0:
 799         case -ENODEV:
 800                 break;
 801         default: /* -EBUSY */
 802                 switch (schib.pmcw.st) {
 803                 case SUBCHANNEL_TYPE_IO:
 804                         if (__clear_io_subchannel_easy(schid))
 805                                 goto out; /* give up... */
 806                         break;
 807                 case SUBCHANNEL_TYPE_CHSC:
 808                         __clear_chsc_subchannel_easy();
 809                         break;
 810                 default:
 811                         /* No default clear strategy */
 812                         break;
 813                 }
 814                 stsch_err(schid, &schib);
 815                 __disable_subchannel_easy(schid, &schib);
 816         }
 817 out:
 818         return 0;
 819 }
 820
 821 static atomic_t chpid_reset_count;
 822
 823 static void s390_reset_chpids_mcck_handler(void)
 824 {
 825         struct crw crw;
 826         struct mci *mci;
 827
 828         /* Check for pending channel report word. */
 829         mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
 830         if (!mci->cp)
 831                 return;
 832         /* Process channel report words. */
 833         while (stcrw(&crw) == 0) {
 834                 /* Check for responses to RCHP. */
 835                 if (crw.slct && crw.rsc == CRW_RSC_CPATH)
 836                         atomic_dec(&chpid_reset_count);
 837         }
 838 }
 839
 840 #define RCHP_TIMEOUT (30 * USEC_PER_SEC)
 841 static void css_reset(void)
 842 {
 843         int i, ret;
 844         unsigned long long timeout;
 845         struct chp_id chpid;
 846
 847         /* Reset subchannels. */
 848         for_each_subchannel(__shutdown_subchannel_easy,  NULL);
 849         /* Reset channel paths. */
 850         s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler;
 851         /* Enable channel report machine checks. */
 852         __ctl_set_bit(14, 28);
 853         /* Temporarily reenable machine checks. */
 854         local_mcck_enable();
 855         chp_id_init(&chpid);
 856         for (i = 0; i <= __MAX_CHPID; i++) {
 857                 chpid.id = i;
 858                 ret = rchp(chpid);
 859                 if ((ret == 0) || (ret == 2))
 860                         /*
 861                          * rchp either succeeded, or another rchp is already
 862                          * in progress. In either case, we'll get a crw.
 863                          */
 864                         atomic_inc(&chpid_reset_count);
 865         }
 866         /* Wait for machine check for all channel paths. */
 867         timeout = get_tod_clock_fast() + (RCHP_TIMEOUT << 12);
 868         while (atomic_read(&chpid_reset_count) != 0) {
 869                 if (get_tod_clock_fast() > timeout)
 870                         break;
 871                 cpu_relax();
 872         }
 873         /* Disable machine checks again. */
 874         local_mcck_disable();
 875         /* Disable channel report machine checks. */
 876         __ctl_clear_bit(14, 28);
 877         s390_base_mcck_handler_fn = NULL;
 878 }
 879
 880 static struct reset_call css_reset_call = {
 881         .fn = css_reset,
 882 };
 883
 884 static int __init init_css_reset_call(void)
 885 {
 886         atomic_set(&chpid_reset_count, 0);
 887         register_reset_call(&css_reset_call);
 888         return 0;
 889 }
 890
 891 arch_initcall(init_css_reset_call);
 892
 893 struct sch_match_id {
 894         struct subchannel_id schid;
 895         struct ccw_dev_id devid;
 896         int rc;
 897 };
 898
 899 static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
 900 {
 901         struct schib schib;
 902         struct sch_match_id *match_id = data;
 903
 904         if (stsch_reset(schid, &schib))
 905                 return -ENXIO;
 906         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
 907             (schib.pmcw.dev == match_id->devid.devno) &&
 908             (schid.ssid == match_id->devid.ssid)) {
 909                 match_id->schid = schid;
 910                 match_id->rc = 0;
 911                 return 1;
 912         }
 913         return 0;
 914 }
 915
 916 static int reipl_find_schid(struct ccw_dev_id *devid,
 917                             struct subchannel_id *schid)
 918 {
 919         struct sch_match_id match_id;
 920
 921         match_id.devid = *devid;
 922         match_id.rc = -ENODEV;
 923         for_each_subchannel(__reipl_subchannel_match, &match_id);
 924         if (match_id.rc == 0)
 925                 *schid = match_id.schid;
 926         return match_id.rc;
 927 }
 928
 929 extern void do_reipl_asm(__u32 schid);
 930
 931 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
 932 void reipl_ccw_dev(struct ccw_dev_id *devid)
 933 {
 934         struct subchannel_id uninitialized_var(schid);
 935
 936         s390_reset_system(NULL, NULL);
 937         if (reipl_find_schid(devid, &schid) != 0)
 938                 panic("IPL Device not found\n");
 939         do_reipl_asm(*((__u32*)&schid));
 940 }
 941
 942 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
 943 {
 944         struct subchannel_id schid;
 945         struct schib schib;
 946
 947         schid = *(struct subchannel_id *)&S390_lowcore.subchannel_id;
 948         if (!schid.one)
 949                 return -ENODEV;
 950         if (stsch_err(schid, &schib))
 951                 return -ENODEV;
 952         if (schib.pmcw.st != SUBCHANNEL_TYPE_IO)
 953                 return -ENODEV;
 954         if (!schib.pmcw.dnv)
 955                 return -ENODEV;
 956         iplinfo->devno = schib.pmcw.dev;
 957         iplinfo->is_qdio = schib.pmcw.qf;
 958         return 0;
 959 }
 960
 961 /**
 962  * cio_tm_start_key - perform start function
 963  * @sch: subchannel on which to perform the start function
 964  * @tcw: transport-command word to be started
 965  * @lpm: mask of paths to use
 966  * @key: storage key to use for storage access
 967  *
 968  * Start the tcw on the given subchannel. Return zero on success, non-zero
 969  * otherwise.
 970  */
 971 int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
 972 {
 973         int cc;
 974         union orb *orb = &to_io_private(sch)->orb;
 975
 976         memset(orb, 0, sizeof(union orb));
 977         orb->tm.intparm = (u32) (addr_t) sch;
 978         orb->tm.key = key >> 4;
 979         orb->tm.b = 1;
 980         orb->tm.lpm = lpm ? lpm : sch->lpm;
 981         orb->tm.tcw = (u32) (addr_t) tcw;
 982         cc = ssch(sch->schid, orb);
 983         switch (cc) {
 984         case 0:
 985                 return 0;
 986         case 1:
 987         case 2:
 988                 return -EBUSY;
 989         default:
 990                 return cio_start_handle_notoper(sch, lpm);
 991         }
 992 }
 993
 994 /**
 995  * cio_tm_intrg - perform interrogate function
 996  * @sch - subchannel on which to perform the interrogate function
 997  *
 998  * If the specified subchannel is running in transport-mode, perform the
 999  * interrogate function. Return zero on success, non-zero otherwie.
1000  */
1001 int cio_tm_intrg(struct subchannel *sch)
1002 {
1003         int cc;
1004
1005         if (!to_io_private(sch)->orb.tm.b)
1006                 return -EINVAL;
1007         cc = xsch(sch->schid);
1008         switch (cc) {
1009         case 0:
1010         case 2:
1011                 return 0;
1012         case 1:
1013                 return -EBUSY;
1014         default:
1015                 return -ENODEV;
1016         }
1017 }