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