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         /*
 147          * for 64 bit we always support 64 bit IDAWs with 4k page size only
 148          */
 149         orb->cmd.c64 = 1;
 150         orb->cmd.i2k = 0;
 151         orb->cmd.key = key >> 4;
 152         /* issue "Start Subchannel" */
 153         orb->cmd.cpa = (__u32) __pa(cpa);
 154         ccode = ssch(sch->schid, orb);
 155
 156         /* process condition code */
 157         CIO_HEX_EVENT(5, &ccode, sizeof(ccode));
 158
 159         switch (ccode) {
 160         case 0:
 161                 /*
 162                  * initialize device status information
 163                  */
 164                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
 165                 return 0;
 166         case 1:         /* status pending */
 167         case 2:         /* busy */
 168                 return -EBUSY;
 169         case 3:         /* device/path not operational */
 170                 return cio_start_handle_notoper(sch, lpm);
 171         default:
 172                 return ccode;
 173         }
 174 }
 175
 176 int
 177 cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
 178 {
 179         return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
 180 }
 181
 182 /*
 183  * resume suspended I/O operation
 184  */
 185 int
 186 cio_resume (struct subchannel *sch)
 187 {
 188         int ccode;
 189
 190         CIO_TRACE_EVENT(4, "resIO");
 191         CIO_TRACE_EVENT(4, dev_name(&sch->dev));
 192
 193         ccode = rsch (sch->schid);
 194
 195         CIO_HEX_EVENT(4, &ccode, sizeof(ccode));
 196
 197         switch (ccode) {
 198         case 0:
 199                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_RESUME_PEND;
 200                 return 0;
 201         case 1:
 202                 return -EBUSY;
 203         case 2:
 204                 return -EINVAL;
 205         default:
 206                 /*
 207                  * useless to wait for request completion
 208                  *  as device is no longer operational !
 209                  */
 210                 return -ENODEV;
 211         }
 212 }
 213
 214 /*
 215  * halt I/O operation
 216  */
 217 int
 218 cio_halt(struct subchannel *sch)
 219 {
 220         int ccode;
 221
 222         if (!sch)
 223                 return -ENODEV;
 224
 225         CIO_TRACE_EVENT(2, "haltIO");
 226         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 227
 228         /*
 229          * Issue "Halt subchannel" and process condition code
 230          */
 231         ccode = hsch (sch->schid);
 232
 233         CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
 234
 235         switch (ccode) {
 236         case 0:
 237                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND;
 238                 return 0;
 239         case 1:         /* status pending */
 240         case 2:         /* busy */
 241                 return -EBUSY;
 242         default:                /* device not operational */
 243                 return -ENODEV;
 244         }
 245 }
 246
 247 /*
 248  * Clear I/O operation
 249  */
 250 int
 251 cio_clear(struct subchannel *sch)
 252 {
 253         int ccode;
 254
 255         if (!sch)
 256                 return -ENODEV;
 257
 258         CIO_TRACE_EVENT(2, "clearIO");
 259         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 260
 261         /*
 262          * Issue "Clear subchannel" and process condition code
 263          */
 264         ccode = csch (sch->schid);
 265
 266         CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
 267
 268         switch (ccode) {
 269         case 0:
 270                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_CLEAR_PEND;
 271                 return 0;
 272         default:                /* device not operational */
 273                 return -ENODEV;
 274         }
 275 }
 276
 277 /*
 278  * Function: cio_cancel
 279  * Issues a "Cancel Subchannel" on the specified subchannel
 280  * Note: We don't need any fancy intparms and flags here
 281  *       since xsch is executed synchronously.
 282  * Only for common I/O internal use as for now.
 283  */
 284 int
 285 cio_cancel (struct subchannel *sch)
 286 {
 287         int ccode;
 288
 289         if (!sch)
 290                 return -ENODEV;
 291
 292         CIO_TRACE_EVENT(2, "cancelIO");
 293         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 294
 295         ccode = xsch (sch->schid);
 296
 297         CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
 298
 299         switch (ccode) {
 300         case 0:         /* success */
 301                 /* Update information in scsw. */
 302                 if (cio_update_schib(sch))
 303                         return -ENODEV;
 304                 return 0;
 305         case 1:         /* status pending */
 306                 return -EBUSY;
 307         case 2:         /* not applicable */
 308                 return -EINVAL;
 309         default:        /* not oper */
 310                 return -ENODEV;
 311         }
 312 }
 313
 314
 315 static void cio_apply_config(struct subchannel *sch, struct schib *schib)
 316 {
 317         schib->pmcw.intparm = sch->config.intparm;
 318         schib->pmcw.mbi = sch->config.mbi;
 319         schib->pmcw.isc = sch->config.isc;
 320         schib->pmcw.ena = sch->config.ena;
 321         schib->pmcw.mme = sch->config.mme;
 322         schib->pmcw.mp = sch->config.mp;
 323         schib->pmcw.csense = sch->config.csense;
 324         schib->pmcw.mbfc = sch->config.mbfc;
 325         if (sch->config.mbfc)
 326                 schib->mba = sch->config.mba;
 327 }
 328
 329 static int cio_check_config(struct subchannel *sch, struct schib *schib)
 330 {
 331         return (schib->pmcw.intparm == sch->config.intparm) &&
 332                 (schib->pmcw.mbi == sch->config.mbi) &&
 333                 (schib->pmcw.isc == sch->config.isc) &&
 334                 (schib->pmcw.ena == sch->config.ena) &&
 335                 (schib->pmcw.mme == sch->config.mme) &&
 336                 (schib->pmcw.mp == sch->config.mp) &&
 337                 (schib->pmcw.csense == sch->config.csense) &&
 338                 (schib->pmcw.mbfc == sch->config.mbfc) &&
 339                 (!sch->config.mbfc || (schib->mba == sch->config.mba));
 340 }
 341
 342 /*
 343  * cio_commit_config - apply configuration to the subchannel
 344  */
 345 int cio_commit_config(struct subchannel *sch)
 346 {
 347         int ccode, retry, ret = 0;
 348         struct schib schib;
 349         struct irb irb;
 350
 351         if (stsch_err(sch->schid, &schib) || !css_sch_is_valid(&schib))
 352                 return -ENODEV;
 353
 354         for (retry = 0; retry < 5; retry++) {
 355                 /* copy desired changes to local schib */
 356                 cio_apply_config(sch, &schib);
 357                 ccode = msch_err(sch->schid, &schib);
 358                 if (ccode < 0) /* -EIO if msch gets a program check. */
 359                         return ccode;
 360                 switch (ccode) {
 361                 case 0: /* successful */
 362                         if (stsch_err(sch->schid, &schib) ||
 363                             !css_sch_is_valid(&schib))
 364                                 return -ENODEV;
 365                         if (cio_check_config(sch, &schib)) {
 366                                 /* commit changes from local schib */
 367                                 memcpy(&sch->schib, &schib, sizeof(schib));
 368                                 return 0;
 369                         }
 370                         ret = -EAGAIN;
 371                         break;
 372                 case 1: /* status pending */
 373                         ret = -EBUSY;
 374                         if (tsch(sch->schid, &irb))
 375                                 return ret;
 376                         break;
 377                 case 2: /* busy */
 378                         udelay(100); /* allow for recovery */
 379                         ret = -EBUSY;
 380                         break;
 381                 case 3: /* not operational */
 382                         return -ENODEV;
 383                 }
 384         }
 385         return ret;
 386 }
 387
 388 /**
 389  * cio_update_schib - Perform stsch and update schib if subchannel is valid.
 390  * @sch: subchannel on which to perform stsch
 391  * Return zero on success, -ENODEV otherwise.
 392  */
 393 int cio_update_schib(struct subchannel *sch)
 394 {
 395         struct schib schib;
 396
 397         if (stsch_err(sch->schid, &schib) || !css_sch_is_valid(&schib))
 398                 return -ENODEV;
 399
 400         memcpy(&sch->schib, &schib, sizeof(schib));
 401         return 0;
 402 }
 403 EXPORT_SYMBOL_GPL(cio_update_schib);
 404
 405 /**
 406  * cio_enable_subchannel - enable a subchannel.
 407  * @sch: subchannel to be enabled
 408  * @intparm: interruption parameter to set
 409  */
 410 int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
 411 {
 412         int ret;
 413
 414         CIO_TRACE_EVENT(2, "ensch");
 415         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 416
 417         if (sch_is_pseudo_sch(sch))
 418                 return -EINVAL;
 419         if (cio_update_schib(sch))
 420                 return -ENODEV;
 421
 422         sch->config.ena = 1;
 423         sch->config.isc = sch->isc;
 424         sch->config.intparm = intparm;
 425
 426         ret = cio_commit_config(sch);
 427         if (ret == -EIO) {
 428                 /*
 429                  * Got a program check in msch. Try without
 430                  * the concurrent sense bit the next time.
 431                  */
 432                 sch->config.csense = 0;
 433                 ret = cio_commit_config(sch);
 434         }
 435         CIO_HEX_EVENT(2, &ret, sizeof(ret));
 436         return ret;
 437 }
 438 EXPORT_SYMBOL_GPL(cio_enable_subchannel);
 439
 440 /**
 441  * cio_disable_subchannel - disable a subchannel.
 442  * @sch: subchannel to disable
 443  */
 444 int cio_disable_subchannel(struct subchannel *sch)
 445 {
 446         int ret;
 447
 448         CIO_TRACE_EVENT(2, "dissch");
 449         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 450
 451         if (sch_is_pseudo_sch(sch))
 452                 return 0;
 453         if (cio_update_schib(sch))
 454                 return -ENODEV;
 455
 456         sch->config.ena = 0;
 457         ret = cio_commit_config(sch);
 458
 459         CIO_HEX_EVENT(2, &ret, sizeof(ret));
 460         return ret;
 461 }
 462 EXPORT_SYMBOL_GPL(cio_disable_subchannel);
 463
 464 static int cio_check_devno_blacklisted(struct subchannel *sch)
 465 {
 466         if (is_blacklisted(sch->schid.ssid, sch->schib.pmcw.dev)) {
 467                 /*
 468                  * This device must not be known to Linux. So we simply
 469                  * say that there is no device and return ENODEV.
 470                  */
 471                 CIO_MSG_EVENT(6, "Blacklisted device detected "
 472                               "at devno %04X, subchannel set %x\n",
 473                               sch->schib.pmcw.dev, sch->schid.ssid);
 474                 return -ENODEV;
 475         }
 476         return 0;
 477 }
 478
 479 static int cio_validate_io_subchannel(struct subchannel *sch)
 480 {
 481         /* Initialization for io subchannels. */
 482         if (!css_sch_is_valid(&sch->schib))
 483                 return -ENODEV;
 484
 485         /* Devno is valid. */
 486         return cio_check_devno_blacklisted(sch);
 487 }
 488
 489 static int cio_validate_msg_subchannel(struct subchannel *sch)
 490 {
 491         /* Initialization for message subchannels. */
 492         if (!css_sch_is_valid(&sch->schib))
 493                 return -ENODEV;
 494
 495         /* Devno is valid. */
 496         return cio_check_devno_blacklisted(sch);
 497 }
 498
 499 /**
 500  * cio_validate_subchannel - basic validation of subchannel
 501  * @sch: subchannel structure to be filled out
 502  * @schid: subchannel id
 503  *
 504  * Find out subchannel type and initialize struct subchannel.
 505  * Return codes:
 506  *   0 on success
 507  *   -ENXIO for non-defined subchannels
 508  *   -ENODEV for invalid subchannels or blacklisted devices
 509  *   -EIO for subchannels in an invalid subchannel set
 510  */
 511 int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
 512 {
 513         char dbf_txt[15];
 514         int ccode;
 515         int err;
 516
 517         sprintf(dbf_txt, "valsch%x", schid.sch_no);
 518         CIO_TRACE_EVENT(4, dbf_txt);
 519
 520         /*
 521          * The first subchannel that is not-operational (ccode==3)
 522          * indicates that there aren't any more devices available.
 523          * If stsch gets an exception, it means the current subchannel set
 524          * is not valid.
 525          */
 526         ccode = stsch_err(schid, &sch->schib);
 527         if (ccode) {
 528                 err = (ccode == 3) ? -ENXIO : ccode;
 529                 goto out;
 530         }
 531         sch->st = sch->schib.pmcw.st;
 532         sch->schid = schid;
 533
 534         switch (sch->st) {
 535         case SUBCHANNEL_TYPE_IO:
 536                 err = cio_validate_io_subchannel(sch);
 537                 break;
 538         case SUBCHANNEL_TYPE_MSG:
 539                 err = cio_validate_msg_subchannel(sch);
 540                 break;
 541         default:
 542                 err = 0;
 543         }
 544         if (err)
 545                 goto out;
 546
 547         CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
 548                       sch->schid.ssid, sch->schid.sch_no, sch->st);
 549 out:
 550         return err;
 551 }
 552
 553 /*
 554  * do_cio_interrupt() handles all normal I/O device IRQ's
 555  */
 556 static irqreturn_t do_cio_interrupt(int irq, void *dummy)
 557 {
 558         struct tpi_info *tpi_info;
 559         struct subchannel *sch;
 560         struct irb *irb;
 561
 562         set_cpu_flag(CIF_NOHZ_DELAY);
 563         tpi_info = (struct tpi_info *) &get_irq_regs()->int_code;
 564         irb = this_cpu_ptr(&cio_irb);
 565         sch = (struct subchannel *)(unsigned long) tpi_info->intparm;
 566         if (!sch) {
 567                 /* Clear pending interrupt condition. */
 568                 inc_irq_stat(IRQIO_CIO);
 569                 tsch(tpi_info->schid, irb);
 570                 return IRQ_HANDLED;
 571         }
 572         spin_lock(sch->lock);
 573         /* Store interrupt response block to lowcore. */
 574         if (tsch(tpi_info->schid, irb) == 0) {
 575                 /* Keep subchannel information word up to date. */
 576                 memcpy (&sch->schib.scsw, &irb->scsw, sizeof (irb->scsw));
 577                 /* Call interrupt handler if there is one. */
 578                 if (sch->driver && sch->driver->irq)
 579                         sch->driver->irq(sch);
 580                 else
 581                         inc_irq_stat(IRQIO_CIO);
 582         } else
 583                 inc_irq_stat(IRQIO_CIO);
 584         spin_unlock(sch->lock);
 585
 586         return IRQ_HANDLED;
 587 }
 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 }
 600
 601 #ifdef CONFIG_CCW_CONSOLE
 602 static struct subchannel *console_sch;
 603 static struct lock_class_key console_sch_key;
 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 = this_cpu_ptr(&cio_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_irq_this_cpu(IO_INTERRUPT);
 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         lockdep_set_class(sch->lock, &console_sch_key);
 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, this_cpu_ptr(&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, 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 }