drivers/s390/cio/cio.c

   1 /*
   2  *   S/390 common I/O routines -- low level i/o calls
   3  *
   4  *    Copyright IBM Corp. 1999, 2008
   5  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
   6  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   7  *               Arnd Bergmann (arndb@de.ibm.com)
   8  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   9  */
  10
  11 #define KMSG_COMPONENT "cio"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/ftrace.h>
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/slab.h>
  18 #include <linux/device.h>
  19 #include <linux/kernel_stat.h>
  20 #include <linux/interrupt.h>
  21 #include <asm/cio.h>
  22 #include <asm/delay.h>
  23 #include <asm/irq.h>
  24 #include <asm/irq_regs.h>
  25 #include <asm/setup.h>
  26 #include <asm/reset.h>
  27 #include <asm/ipl.h>
  28 #include <asm/chpid.h>
  29 #include <asm/airq.h>
  30 #include <asm/isc.h>
  31 #include <linux/cputime.h>
  32 #include <asm/fcx.h>
  33 #include <asm/nmi.h>
  34 #include <asm/crw.h>
  35 #include "cio.h"
  36 #include "css.h"
  37 #include "chsc.h"
  38 #include "ioasm.h"
  39 #include "io_sch.h"
  40 #include "blacklist.h"
  41 #include "cio_debug.h"
  42 #include "chp.h"
  43
  44 debug_info_t *cio_debug_msg_id;
  45 debug_info_t *cio_debug_trace_id;
  46 debug_info_t *cio_debug_crw_id;
  47
  48 /*
  49  * Function: cio_debug_init
  50  * Initializes three debug logs for common I/O:
  51  * - cio_msg logs generic cio messages
  52  * - cio_trace logs the calling of different functions
  53  * - cio_crw logs machine check related cio messages
  54  */
  55 static int __init cio_debug_init(void)
  56 {
  57         cio_debug_msg_id = debug_register("cio_msg", 16, 1, 11 * sizeof(long));
  58         if (!cio_debug_msg_id)
  59                 goto out_unregister;
  60         debug_register_view(cio_debug_msg_id, &debug_sprintf_view);
  61         debug_set_level(cio_debug_msg_id, 2);
  62         cio_debug_trace_id = debug_register("cio_trace", 16, 1, 16);
  63         if (!cio_debug_trace_id)
  64                 goto out_unregister;
  65         debug_register_view(cio_debug_trace_id, &debug_hex_ascii_view);
  66         debug_set_level(cio_debug_trace_id, 2);
  67         cio_debug_crw_id = debug_register("cio_crw", 8, 1, 8 * sizeof(long));
  68         if (!cio_debug_crw_id)
  69                 goto out_unregister;
  70         debug_register_view(cio_debug_crw_id, &debug_sprintf_view);
  71         debug_set_level(cio_debug_crw_id, 4);
  72         return 0;
  73
  74 out_unregister:
  75         if (cio_debug_msg_id)
  76                 debug_unregister(cio_debug_msg_id);
  77         if (cio_debug_trace_id)
  78                 debug_unregister(cio_debug_trace_id);
  79         if (cio_debug_crw_id)
  80                 debug_unregister(cio_debug_crw_id);
  81         return -1;
  82 }
  83
  84 arch_initcall (cio_debug_init);
  85
  86 int cio_set_options(struct subchannel *sch, int flags)
  87 {
  88         struct io_subchannel_private *priv = to_io_private(sch);
  89
  90         priv->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
  91         priv->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
  92         priv->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
  93         return 0;
  94 }
  95
  96 static int
  97 cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
  98 {
  99         char dbf_text[15];
 100
 101         if (lpm != 0)
 102                 sch->lpm &= ~lpm;
 103         else
 104                 sch->lpm = 0;
 105
 106         CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
 107                       "subchannel 0.%x.%04x!\n", sch->schid.ssid,
 108                       sch->schid.sch_no);
 109
 110         if (cio_update_schib(sch))
 111                 return -ENODEV;
 112
 113         sprintf(dbf_text, "no%s", dev_name(&sch->dev));
 114         CIO_TRACE_EVENT(0, dbf_text);
 115         CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
 116
 117         return (sch->lpm ? -EACCES : -ENODEV);
 118 }
 119
 120 int
 121 cio_start_key (struct subchannel *sch,  /* subchannel structure */
 122                struct ccw1 * cpa,       /* logical channel prog addr */
 123                __u8 lpm,                /* logical path mask */
 124                __u8 key)                /* storage key */
 125 {
 126         struct io_subchannel_private *priv = to_io_private(sch);
 127         union orb *orb = &priv->orb;
 128         int ccode;
 129
 130         CIO_TRACE_EVENT(5, "stIO");
 131         CIO_TRACE_EVENT(5, dev_name(&sch->dev));
 132
 133         memset(orb, 0, sizeof(union orb));
 134         /* sch is always under 2G. */
 135         orb->cmd.intparm = (u32)(addr_t)sch;
 136         orb->cmd.fmt = 1;
 137
 138         orb->cmd.pfch = priv->options.prefetch == 0;
 139         orb->cmd.spnd = priv->options.suspend;
 140         orb->cmd.ssic = priv->options.suspend && priv->options.inter;
 141         orb->cmd.lpm = (lpm != 0) ? lpm : sch->lpm;
 142 #ifdef CONFIG_64BIT
 143         /*
 144          * for 64 bit we always support 64 bit IDAWs with 4k page size only
 145          */
 146         orb->cmd.c64 = 1;
 147         orb->cmd.i2k = 0;
 148 #endif
 149         orb->cmd.key = key >> 4;
 150         /* issue "Start Subchannel" */
 151         orb->cmd.cpa = (__u32) __pa(cpa);
 152         ccode = ssch(sch->schid, orb);
 153
 154         /* process condition code */
 155         CIO_HEX_EVENT(5, &ccode, sizeof(ccode));
 156
 157         switch (ccode) {
 158         case 0:
 159                 /*
 160                  * initialize device status information
 161                  */
 162                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
 163                 return 0;
 164         case 1:         /* status pending */
 165         case 2:         /* busy */
 166                 return -EBUSY;
 167         case 3:         /* device/path not operational */
 168                 return cio_start_handle_notoper(sch, lpm);
 169         default:
 170                 return ccode;
 171         }
 172 }
 173
 174 int
 175 cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
 176 {
 177         return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
 178 }
 179
 180 /*
 181  * resume suspended I/O operation
 182  */
 183 int
 184 cio_resume (struct subchannel *sch)
 185 {
 186         int ccode;
 187
 188         CIO_TRACE_EVENT(4, "resIO");
 189         CIO_TRACE_EVENT(4, dev_name(&sch->dev));
 190
 191         ccode = rsch (sch->schid);
 192
 193         CIO_HEX_EVENT(4, &ccode, sizeof(ccode));
 194
 195         switch (ccode) {
 196         case 0:
 197                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_RESUME_PEND;
 198                 return 0;
 199         case 1:
 200                 return -EBUSY;
 201         case 2:
 202                 return -EINVAL;
 203         default:
 204                 /*
 205                  * useless to wait for request completion
 206                  *  as device is no longer operational !
 207                  */
 208                 return -ENODEV;
 209         }
 210 }
 211
 212 /*
 213  * halt I/O operation
 214  */
 215 int
 216 cio_halt(struct subchannel *sch)
 217 {
 218         int ccode;
 219
 220         if (!sch)
 221                 return -ENODEV;
 222
 223         CIO_TRACE_EVENT(2, "haltIO");
 224         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 225
 226         /*
 227          * Issue "Halt subchannel" and process condition code
 228          */
 229         ccode = hsch (sch->schid);
 230
 231         CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
 232
 233         switch (ccode) {
 234         case 0:
 235                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND;
 236                 return 0;
 237         case 1:         /* status pending */
 238         case 2:         /* busy */
 239                 return -EBUSY;
 240         default:                /* device not operational */
 241                 return -ENODEV;
 242         }
 243 }
 244
 245 /*
 246  * Clear I/O operation
 247  */
 248 int
 249 cio_clear(struct subchannel *sch)
 250 {
 251         int ccode;
 252
 253         if (!sch)
 254                 return -ENODEV;
 255
 256         CIO_TRACE_EVENT(2, "clearIO");
 257         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 258
 259         /*
 260          * Issue "Clear subchannel" and process condition code
 261          */
 262         ccode = csch (sch->schid);
 263
 264         CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
 265
 266         switch (ccode) {
 267         case 0:
 268                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_CLEAR_PEND;
 269                 return 0;
 270         default:                /* device not operational */
 271                 return -ENODEV;
 272         }
 273 }
 274
 275 /*
 276  * Function: cio_cancel
 277  * Issues a "Cancel Subchannel" on the specified subchannel
 278  * Note: We don't need any fancy intparms and flags here
 279  *       since xsch is executed synchronously.
 280  * Only for common I/O internal use as for now.
 281  */
 282 int
 283 cio_cancel (struct subchannel *sch)
 284 {
 285         int ccode;
 286
 287         if (!sch)
 288                 return -ENODEV;
 289
 290         CIO_TRACE_EVENT(2, "cancelIO");
 291         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 292
 293         ccode = xsch (sch->schid);
 294
 295         CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
 296
 297         switch (ccode) {
 298         case 0:         /* success */
 299                 /* Update information in scsw. */
 300                 if (cio_update_schib(sch))
 301                         return -ENODEV;
 302                 return 0;
 303         case 1:         /* status pending */
 304                 return -EBUSY;
 305         case 2:         /* not applicable */
 306                 return -EINVAL;
 307         default:        /* not oper */
 308                 return -ENODEV;
 309         }
 310 }
 311
 312
 313 static void cio_apply_config(struct subchannel *sch, struct schib *schib)
 314 {
 315         schib->pmcw.intparm = sch->config.intparm;
 316         schib->pmcw.mbi = sch->config.mbi;
 317         schib->pmcw.isc = sch->config.isc;
 318         schib->pmcw.ena = sch->config.ena;
 319         schib->pmcw.mme = sch->config.mme;
 320         schib->pmcw.mp = sch->config.mp;
 321         schib->pmcw.csense = sch->config.csense;
 322         schib->pmcw.mbfc = sch->config.mbfc;
 323         if (sch->config.mbfc)
 324                 schib->mba = sch->config.mba;
 325 }
 326
 327 static int cio_check_config(struct subchannel *sch, struct schib *schib)
 328 {
 329         return (schib->pmcw.intparm == sch->config.intparm) &&
 330                 (schib->pmcw.mbi == sch->config.mbi) &&
 331                 (schib->pmcw.isc == sch->config.isc) &&
 332                 (schib->pmcw.ena == sch->config.ena) &&
 333                 (schib->pmcw.mme == sch->config.mme) &&
 334                 (schib->pmcw.mp == sch->config.mp) &&
 335                 (schib->pmcw.csense == sch->config.csense) &&
 336                 (schib->pmcw.mbfc == sch->config.mbfc) &&
 337                 (!sch->config.mbfc || (schib->mba == sch->config.mba));
 338 }
 339
 340 /*
 341  * cio_commit_config - apply configuration to the subchannel
 342  */
 343 int cio_commit_config(struct subchannel *sch)
 344 {
 345         int ccode, retry, ret = 0;
 346         struct schib schib;
 347         struct irb irb;
 348
 349         if (stsch_err(sch->schid, &schib) || !css_sch_is_valid(&schib))
 350                 return -ENODEV;
 351
 352         for (retry = 0; retry < 5; retry++) {
 353                 /* copy desired changes to local schib */
 354                 cio_apply_config(sch, &schib);
 355                 ccode = msch_err(sch->schid, &schib);
 356                 if (ccode < 0) /* -EIO if msch gets a program check. */
 357                         return ccode;
 358                 switch (ccode) {
 359                 case 0: /* successful */
 360                         if (stsch_err(sch->schid, &schib) ||
 361                             !css_sch_is_valid(&schib))
 362                                 return -ENODEV;
 363                         if (cio_check_config(sch, &schib)) {
 364                                 /* commit changes from local schib */
 365                                 memcpy(&sch->schib, &schib, sizeof(schib));
 366                                 return 0;
 367                         }
 368                         ret = -EAGAIN;
 369                         break;
 370                 case 1: /* status pending */
 371                         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_err(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 static int cio_validate_io_subchannel(struct subchannel *sch)
 478 {
 479         /* Initialization for io subchannels. */
 480         if (!css_sch_is_valid(&sch->schib))
 481                 return -ENODEV;
 482
 483         /* Devno is valid. */
 484         return cio_check_devno_blacklisted(sch);
 485 }
 486
 487 static int cio_validate_msg_subchannel(struct subchannel *sch)
 488 {
 489         /* Initialization for message subchannels. */
 490         if (!css_sch_is_valid(&sch->schib))
 491                 return -ENODEV;
 492
 493         /* Devno is valid. */
 494         return cio_check_devno_blacklisted(sch);
 495 }
 496
 497 /**
 498  * cio_validate_subchannel - basic validation of subchannel
 499  * @sch: subchannel structure to be filled out
 500  * @schid: subchannel id
 501  *
 502  * Find out subchannel type and initialize struct subchannel.
 503  * Return codes:
 504  *   0 on success
 505  *   -ENXIO for non-defined subchannels
 506  *   -ENODEV for invalid subchannels or blacklisted devices
 507  *   -EIO for subchannels in an invalid subchannel set
 508  */
 509 int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
 510 {
 511         char dbf_txt[15];
 512         int ccode;
 513         int err;
 514
 515         sprintf(dbf_txt, "valsch%x", schid.sch_no);
 516         CIO_TRACE_EVENT(4, dbf_txt);
 517
 518         /*
 519          * The first subchannel that is not-operational (ccode==3)
 520          * indicates that there aren't any more devices available.
 521          * If stsch gets an exception, it means the current subchannel set
 522          * is not valid.
 523          */
 524         ccode = stsch_err(schid, &sch->schib);
 525         if (ccode) {
 526                 err = (ccode == 3) ? -ENXIO : ccode;
 527                 goto out;
 528         }
 529         sch->st = sch->schib.pmcw.st;
 530         sch->schid = schid;
 531
 532         switch (sch->st) {
 533         case SUBCHANNEL_TYPE_IO:
 534                 err = cio_validate_io_subchannel(sch);
 535                 break;
 536         case SUBCHANNEL_TYPE_MSG:
 537                 err = cio_validate_msg_subchannel(sch);
 538                 break;
 539         default:
 540                 err = 0;
 541         }
 542         if (err)
 543                 goto out;
 544
 545         CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
 546                       sch->schid.ssid, sch->schid.sch_no, sch->st);
 547 out:
 548         return err;
 549 }
 550
 551 /*
 552  * do_cio_interrupt() handles all normal I/O device IRQ's
 553  */
 554 static irqreturn_t do_cio_interrupt(int irq, void *dummy)
 555 {
 556         struct tpi_info *tpi_info;
 557         struct subchannel *sch;
 558         struct irb *irb;
 559
 560         __this_cpu_write(s390_idle.nohz_delay, 1);
 561         tpi_info = (struct tpi_info *) &get_irq_regs()->int_code;
 562         irb = (struct irb *) &S390_lowcore.irb;
 563         sch = (struct subchannel *)(unsigned long) tpi_info->intparm;
 564         if (!sch) {
 565                 /* Clear pending interrupt condition. */
 566                 inc_irq_stat(IRQIO_CIO);
 567                 tsch(tpi_info->schid, irb);
 568                 return IRQ_HANDLED;
 569         }
 570         spin_lock(sch->lock);
 571         /* Store interrupt response block to lowcore. */
 572         if (tsch(tpi_info->schid, irb) == 0) {
 573                 /* Keep subchannel information word up to date. */
 574                 memcpy (&sch->schib.scsw, &irb->scsw, sizeof (irb->scsw));
 575                 /* Call interrupt handler if there is one. */
 576                 if (sch->driver && sch->driver->irq)
 577                         sch->driver->irq(sch);
 578                 else
 579                         inc_irq_stat(IRQIO_CIO);
 580         } else
 581                 inc_irq_stat(IRQIO_CIO);
 582         spin_unlock(sch->lock);
 583
 584         return IRQ_HANDLED;
 585 }
 586
 587 static struct irq_desc *irq_desc_io;
 588
 589 static struct irqaction io_interrupt = {
 590         .name    = "IO",
 591         .handler = do_cio_interrupt,
 592 };
 593
 594 void __init init_cio_interrupts(void)
 595 {
 596         irq_set_chip_and_handler(IO_INTERRUPT,
 597                                  &dummy_irq_chip, handle_percpu_irq);
 598         setup_irq(IO_INTERRUPT, &io_interrupt);
 599         irq_desc_io = irq_to_desc(IO_INTERRUPT);
 600 }
 601
 602 #ifdef CONFIG_CCW_CONSOLE
 603 static struct subchannel *console_sch;
 604
 605 /*
 606  * Use cio_tsch to update the subchannel status and call the interrupt handler
 607  * if status had been pending. Called with the subchannel's lock held.
 608  */
 609 void cio_tsch(struct subchannel *sch)
 610 {
 611         struct irb *irb;
 612         int irq_context;
 613
 614         irb = (struct irb *)&S390_lowcore.irb;
 615         /* Store interrupt response block to lowcore. */
 616         if (tsch(sch->schid, irb) != 0)
 617                 /* Not status pending or not operational. */
 618                 return;
 619         memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
 620         /* Call interrupt handler with updated status. */
 621         irq_context = in_interrupt();
 622         if (!irq_context) {
 623                 local_bh_disable();
 624                 irq_enter();
 625         }
 626         kstat_incr_irqs_this_cpu(IO_INTERRUPT, irq_desc_io);
 627         if (sch->driver && sch->driver->irq)
 628                 sch->driver->irq(sch);
 629         else
 630                 inc_irq_stat(IRQIO_CIO);
 631         if (!irq_context) {
 632                 irq_exit();
 633                 _local_bh_enable();
 634         }
 635 }
 636
 637 static int cio_test_for_console(struct subchannel_id schid, void *data)
 638 {
 639         struct schib schib;
 640
 641         if (stsch_err(schid, &schib) != 0)
 642                 return -ENXIO;
 643         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
 644             (schib.pmcw.dev == console_devno)) {
 645                 console_irq = schid.sch_no;
 646                 return 1; /* found */
 647         }
 648         return 0;
 649 }
 650
 651 static int cio_get_console_sch_no(void)
 652 {
 653         struct subchannel_id schid;
 654         struct schib schib;
 655
 656         init_subchannel_id(&schid);
 657         if (console_irq != -1) {
 658                 /* VM provided us with the irq number of the console. */
 659                 schid.sch_no = console_irq;
 660                 if (stsch_err(schid, &schib) != 0 ||
 661                     (schib.pmcw.st != SUBCHANNEL_TYPE_IO) || !schib.pmcw.dnv)
 662                         return -1;
 663                 console_devno = schib.pmcw.dev;
 664         } else if (console_devno != -1) {
 665                 /* At least the console device number is known. */
 666                 for_each_subchannel(cio_test_for_console, NULL);
 667         }
 668         return console_irq;
 669 }
 670
 671 struct subchannel *cio_probe_console(void)
 672 {
 673         struct subchannel_id schid;
 674         struct subchannel *sch;
 675         int sch_no, ret;
 676
 677         sch_no = cio_get_console_sch_no();
 678         if (sch_no == -1) {
 679                 pr_warning("No CCW console was found\n");
 680                 return ERR_PTR(-ENODEV);
 681         }
 682         init_subchannel_id(&schid);
 683         schid.sch_no = sch_no;
 684         sch = css_alloc_subchannel(schid);
 685         if (IS_ERR(sch))
 686                 return sch;
 687
 688         isc_register(CONSOLE_ISC);
 689         sch->config.isc = CONSOLE_ISC;
 690         sch->config.intparm = (u32)(addr_t)sch;
 691         ret = cio_commit_config(sch);
 692         if (ret) {
 693                 isc_unregister(CONSOLE_ISC);
 694                 put_device(&sch->dev);
 695                 return ERR_PTR(ret);
 696         }
 697         console_sch = sch;
 698         return sch;
 699 }
 700
 701 int cio_is_console(struct subchannel_id schid)
 702 {
 703         if (!console_sch)
 704                 return 0;
 705         return schid_equal(&schid, &console_sch->schid);
 706 }
 707
 708 void cio_register_early_subchannels(void)
 709 {
 710         int ret;
 711
 712         if (!console_sch)
 713                 return;
 714
 715         ret = css_register_subchannel(console_sch);
 716         if (ret)
 717                 put_device(&console_sch->dev);
 718 }
 719 #endif /* CONFIG_CCW_CONSOLE */
 720
 721 static int
 722 __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
 723 {
 724         int retry, cc;
 725
 726         cc = 0;
 727         for (retry=0;retry<3;retry++) {
 728                 schib->pmcw.ena = 0;
 729                 cc = msch_err(schid, schib);
 730                 if (cc)
 731                         return (cc==3?-ENODEV:-EBUSY);
 732                 if (stsch_err(schid, schib) || !css_sch_is_valid(schib))
 733                         return -ENODEV;
 734                 if (!schib->pmcw.ena)
 735                         return 0;
 736         }
 737         return -EBUSY; /* uhm... */
 738 }
 739
 740 static int
 741 __clear_io_subchannel_easy(struct subchannel_id schid)
 742 {
 743         int retry;
 744
 745         if (csch(schid))
 746                 return -ENODEV;
 747         for (retry=0;retry<20;retry++) {
 748                 struct tpi_info ti;
 749
 750                 if (tpi(&ti)) {
 751                         tsch(ti.schid, (struct irb *)&S390_lowcore.irb);
 752                         if (schid_equal(&ti.schid, &schid))
 753                                 return 0;
 754                 }
 755                 udelay_simple(100);
 756         }
 757         return -EBUSY;
 758 }
 759
 760 static void __clear_chsc_subchannel_easy(void)
 761 {
 762         /* It seems we can only wait for a bit here :/ */
 763         udelay_simple(100);
 764 }
 765
 766 static int pgm_check_occured;
 767
 768 static void cio_reset_pgm_check_handler(void)
 769 {
 770         pgm_check_occured = 1;
 771 }
 772
 773 static int stsch_reset(struct subchannel_id schid, struct schib *addr)
 774 {
 775         int rc;
 776
 777         pgm_check_occured = 0;
 778         s390_base_pgm_handler_fn = cio_reset_pgm_check_handler;
 779         rc = stsch_err(schid, addr);
 780         s390_base_pgm_handler_fn = NULL;
 781
 782         /* The program check handler could have changed pgm_check_occured. */
 783         barrier();
 784
 785         if (pgm_check_occured)
 786                 return -EIO;
 787         else
 788                 return rc;
 789 }
 790
 791 static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
 792 {
 793         struct schib schib;
 794
 795         if (stsch_reset(schid, &schib))
 796                 return -ENXIO;
 797         if (!schib.pmcw.ena)
 798                 return 0;
 799         switch(__disable_subchannel_easy(schid, &schib)) {
 800         case 0:
 801         case -ENODEV:
 802                 break;
 803         default: /* -EBUSY */
 804                 switch (schib.pmcw.st) {
 805                 case SUBCHANNEL_TYPE_IO:
 806                         if (__clear_io_subchannel_easy(schid))
 807                                 goto out; /* give up... */
 808                         break;
 809                 case SUBCHANNEL_TYPE_CHSC:
 810                         __clear_chsc_subchannel_easy();
 811                         break;
 812                 default:
 813                         /* No default clear strategy */
 814                         break;
 815                 }
 816                 stsch_err(schid, &schib);
 817                 __disable_subchannel_easy(schid, &schib);
 818         }
 819 out:
 820         return 0;
 821 }
 822
 823 static atomic_t chpid_reset_count;
 824
 825 static void s390_reset_chpids_mcck_handler(void)
 826 {
 827         struct crw crw;
 828         struct mci *mci;
 829
 830         /* Check for pending channel report word. */
 831         mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
 832         if (!mci->cp)
 833                 return;
 834         /* Process channel report words. */
 835         while (stcrw(&crw) == 0) {
 836                 /* Check for responses to RCHP. */
 837                 if (crw.slct && crw.rsc == CRW_RSC_CPATH)
 838                         atomic_dec(&chpid_reset_count);
 839         }
 840 }
 841
 842 #define RCHP_TIMEOUT (30 * USEC_PER_SEC)
 843 static void css_reset(void)
 844 {
 845         int i, ret;
 846         unsigned long long timeout;
 847         struct chp_id chpid;
 848
 849         /* Reset subchannels. */
 850         for_each_subchannel(__shutdown_subchannel_easy,  NULL);
 851         /* Reset channel paths. */
 852         s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler;
 853         /* Enable channel report machine checks. */
 854         __ctl_set_bit(14, 28);
 855         /* Temporarily reenable machine checks. */
 856         local_mcck_enable();
 857         chp_id_init(&chpid);
 858         for (i = 0; i <= __MAX_CHPID; i++) {
 859                 chpid.id = i;
 860                 ret = rchp(chpid);
 861                 if ((ret == 0) || (ret == 2))
 862                         /*
 863                          * rchp either succeeded, or another rchp is already
 864                          * in progress. In either case, we'll get a crw.
 865                          */
 866                         atomic_inc(&chpid_reset_count);
 867         }
 868         /* Wait for machine check for all channel paths. */
 869         timeout = get_tod_clock_fast() + (RCHP_TIMEOUT << 12);
 870         while (atomic_read(&chpid_reset_count) != 0) {
 871                 if (get_tod_clock_fast() > timeout)
 872                         break;
 873                 cpu_relax();
 874         }
 875         /* Disable machine checks again. */
 876         local_mcck_disable();
 877         /* Disable channel report machine checks. */
 878         __ctl_clear_bit(14, 28);
 879         s390_base_mcck_handler_fn = NULL;
 880 }
 881
 882 static struct reset_call css_reset_call = {
 883         .fn = css_reset,
 884 };
 885
 886 static int __init init_css_reset_call(void)
 887 {
 888         atomic_set(&chpid_reset_count, 0);
 889         register_reset_call(&css_reset_call);
 890         return 0;
 891 }
 892
 893 arch_initcall(init_css_reset_call);
 894
 895 struct sch_match_id {
 896         struct subchannel_id schid;
 897         struct ccw_dev_id devid;
 898         int rc;
 899 };
 900
 901 static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
 902 {
 903         struct schib schib;
 904         struct sch_match_id *match_id = data;
 905
 906         if (stsch_reset(schid, &schib))
 907                 return -ENXIO;
 908         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
 909             (schib.pmcw.dev == match_id->devid.devno) &&
 910             (schid.ssid == match_id->devid.ssid)) {
 911                 match_id->schid = schid;
 912                 match_id->rc = 0;
 913                 return 1;
 914         }
 915         return 0;
 916 }
 917
 918 static int reipl_find_schid(struct ccw_dev_id *devid,
 919                             struct subchannel_id *schid)
 920 {
 921         struct sch_match_id match_id;
 922
 923         match_id.devid = *devid;
 924         match_id.rc = -ENODEV;
 925         for_each_subchannel(__reipl_subchannel_match, &match_id);
 926         if (match_id.rc == 0)
 927                 *schid = match_id.schid;
 928         return match_id.rc;
 929 }
 930
 931 extern void do_reipl_asm(__u32 schid);
 932
 933 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
 934 void reipl_ccw_dev(struct ccw_dev_id *devid)
 935 {
 936         struct subchannel_id uninitialized_var(schid);
 937
 938         s390_reset_system(NULL, NULL);
 939         if (reipl_find_schid(devid, &schid) != 0)
 940                 panic("IPL Device not found\n");
 941         do_reipl_asm(*((__u32*)&schid));
 942 }
 943
 944 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
 945 {
 946         struct subchannel_id schid;
 947         struct schib schib;
 948
 949         schid = *(struct subchannel_id *)&S390_lowcore.subchannel_id;
 950         if (!schid.one)
 951                 return -ENODEV;
 952         if (stsch_err(schid, &schib))
 953                 return -ENODEV;
 954         if (schib.pmcw.st != SUBCHANNEL_TYPE_IO)
 955                 return -ENODEV;
 956         if (!schib.pmcw.dnv)
 957                 return -ENODEV;
 958         iplinfo->devno = schib.pmcw.dev;
 959         iplinfo->is_qdio = schib.pmcw.qf;
 960         return 0;
 961 }
 962
 963 /**
 964  * cio_tm_start_key - perform start function
 965  * @sch: subchannel on which to perform the start function
 966  * @tcw: transport-command word to be started
 967  * @lpm: mask of paths to use
 968  * @key: storage key to use for storage access
 969  *
 970  * Start the tcw on the given subchannel. Return zero on success, non-zero
 971  * otherwise.
 972  */
 973 int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
 974 {
 975         int cc;
 976         union orb *orb = &to_io_private(sch)->orb;
 977
 978         memset(orb, 0, sizeof(union orb));
 979         orb->tm.intparm = (u32) (addr_t) sch;
 980         orb->tm.key = key >> 4;
 981         orb->tm.b = 1;
 982         orb->tm.lpm = lpm ? lpm : sch->lpm;
 983         orb->tm.tcw = (u32) (addr_t) tcw;
 984         cc = ssch(sch->schid, orb);
 985         switch (cc) {
 986         case 0:
 987                 return 0;
 988         case 1:
 989         case 2:
 990                 return -EBUSY;
 991         default:
 992                 return cio_start_handle_notoper(sch, lpm);
 993         }
 994 }
 995
 996 /**
 997  * cio_tm_intrg - perform interrogate function
 998  * @sch - subchannel on which to perform the interrogate function
 999  *
1000  * If the specified subchannel is running in transport-mode, perform the
1001  * interrogate function. Return zero on success, non-zero otherwie.
1002  */
1003 int cio_tm_intrg(struct subchannel *sch)
1004 {
1005         int cc;
1006
1007         if (!to_io_private(sch)->orb.tm.b)
1008                 return -EINVAL;
1009         cc = xsch(sch->schid);
1010         switch (cc) {
1011         case 0:
1012         case 2:
1013                 return 0;
1014         case 1:
1015                 return -EBUSY;
1016         default:
1017                 return -ENODEV;
1018         }
1019 }