drivers/s390/cio/cio.c

   1 /*
   2  *  drivers/s390/cio/cio.c
   3  *   S/390 common I/O routines -- low level i/o calls
   4  *
   5  *    Copyright IBM Corp. 1999,2008
   6  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
   7  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   8  *               Arnd Bergmann (arndb@de.ibm.com)
   9  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/slab.h>
  15 #include <linux/device.h>
  16 #include <linux/kernel_stat.h>
  17 #include <linux/interrupt.h>
  18 #include <asm/cio.h>
  19 #include <asm/delay.h>
  20 #include <asm/irq.h>
  21 #include <asm/irq_regs.h>
  22 #include <asm/setup.h>
  23 #include <asm/reset.h>
  24 #include <asm/ipl.h>
  25 #include <asm/chpid.h>
  26 #include <asm/airq.h>
  27 #include <asm/isc.h>
  28 #include <asm/cpu.h>
  29 #include <asm/fcx.h>
  30 #include "cio.h"
  31 #include "css.h"
  32 #include "chsc.h"
  33 #include "ioasm.h"
  34 #include "io_sch.h"
  35 #include "blacklist.h"
  36 #include "cio_debug.h"
  37 #include "chp.h"
  38 #include "../s390mach.h"
  39
  40 debug_info_t *cio_debug_msg_id;
  41 debug_info_t *cio_debug_trace_id;
  42 debug_info_t *cio_debug_crw_id;
  43
  44 /*
  45  * Function: cio_debug_init
  46  * Initializes three debug logs for common I/O:
  47  * - cio_msg logs generic cio messages
  48  * - cio_trace logs the calling of different functions
  49  * - cio_crw logs machine check related cio messages
  50  */
  51 static int __init cio_debug_init(void)
  52 {
  53         cio_debug_msg_id = debug_register("cio_msg", 16, 1, 16 * sizeof(long));
  54         if (!cio_debug_msg_id)
  55                 goto out_unregister;
  56         debug_register_view(cio_debug_msg_id, &debug_sprintf_view);
  57         debug_set_level(cio_debug_msg_id, 2);
  58         cio_debug_trace_id = debug_register("cio_trace", 16, 1, 16);
  59         if (!cio_debug_trace_id)
  60                 goto out_unregister;
  61         debug_register_view(cio_debug_trace_id, &debug_hex_ascii_view);
  62         debug_set_level(cio_debug_trace_id, 2);
  63         cio_debug_crw_id = debug_register("cio_crw", 16, 1, 16 * sizeof(long));
  64         if (!cio_debug_crw_id)
  65                 goto out_unregister;
  66         debug_register_view(cio_debug_crw_id, &debug_sprintf_view);
  67         debug_set_level(cio_debug_crw_id, 4);
  68         return 0;
  69
  70 out_unregister:
  71         if (cio_debug_msg_id)
  72                 debug_unregister(cio_debug_msg_id);
  73         if (cio_debug_trace_id)
  74                 debug_unregister(cio_debug_trace_id);
  75         if (cio_debug_crw_id)
  76                 debug_unregister(cio_debug_crw_id);
  77         return -1;
  78 }
  79
  80 arch_initcall (cio_debug_init);
  81
  82 int
  83 cio_set_options (struct subchannel *sch, int flags)
  84 {
  85        sch->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
  86        sch->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
  87        sch->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
  88        return 0;
  89 }
  90
  91 /* FIXME: who wants to use this? */
  92 int
  93 cio_get_options (struct subchannel *sch)
  94 {
  95        int flags;
  96
  97        flags = 0;
  98        if (sch->options.suspend)
  99                 flags |= DOIO_ALLOW_SUSPEND;
 100        if (sch->options.prefetch)
 101                 flags |= DOIO_DENY_PREFETCH;
 102        if (sch->options.inter)
 103                 flags |= DOIO_SUPPRESS_INTER;
 104        return flags;
 105 }
 106
 107 /*
 108  * Use tpi to get a pending interrupt, call the interrupt handler and
 109  * return a pointer to the subchannel structure.
 110  */
 111 static int
 112 cio_tpi(void)
 113 {
 114         struct tpi_info *tpi_info;
 115         struct subchannel *sch;
 116         struct irb *irb;
 117         int irq_context;
 118
 119         tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
 120         if (tpi (NULL) != 1)
 121                 return 0;
 122         irb = (struct irb *) __LC_IRB;
 123         /* Store interrupt response block to lowcore. */
 124         if (tsch (tpi_info->schid, irb) != 0)
 125                 /* Not status pending or not operational. */
 126                 return 1;
 127         sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 128         if (!sch)
 129                 return 1;
 130         irq_context = in_interrupt();
 131         if (!irq_context)
 132                 local_bh_disable();
 133         irq_enter ();
 134         spin_lock(sch->lock);
 135         memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
 136         if (sch->driver && sch->driver->irq)
 137                 sch->driver->irq(sch);
 138         spin_unlock(sch->lock);
 139         irq_exit ();
 140         if (!irq_context)
 141                 _local_bh_enable();
 142         return 1;
 143 }
 144
 145 static int
 146 cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
 147 {
 148         char dbf_text[15];
 149
 150         if (lpm != 0)
 151                 sch->lpm &= ~lpm;
 152         else
 153                 sch->lpm = 0;
 154
 155         stsch (sch->schid, &sch->schib);
 156
 157         CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
 158                       "subchannel 0.%x.%04x!\n", sch->schid.ssid,
 159                       sch->schid.sch_no);
 160         sprintf(dbf_text, "no%s", dev_name(&sch->dev));
 161         CIO_TRACE_EVENT(0, dbf_text);
 162         CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
 163
 164         return (sch->lpm ? -EACCES : -ENODEV);
 165 }
 166
 167 int
 168 cio_start_key (struct subchannel *sch,  /* subchannel structure */
 169                struct ccw1 * cpa,       /* logical channel prog addr */
 170                __u8 lpm,                /* logical path mask */
 171                __u8 key)                /* storage key */
 172 {
 173         char dbf_txt[15];
 174         int ccode;
 175         union orb *orb;
 176
 177         CIO_TRACE_EVENT(4, "stIO");
 178         CIO_TRACE_EVENT(4, dev_name(&sch->dev));
 179
 180         orb = &to_io_private(sch)->orb;
 181         memset(orb, 0, sizeof(union orb));
 182         /* sch is always under 2G. */
 183         orb->cmd.intparm = (u32)(addr_t)sch;
 184         orb->cmd.fmt = 1;
 185
 186         orb->cmd.pfch = sch->options.prefetch == 0;
 187         orb->cmd.spnd = sch->options.suspend;
 188         orb->cmd.ssic = sch->options.suspend && sch->options.inter;
 189         orb->cmd.lpm = (lpm != 0) ? lpm : sch->lpm;
 190 #ifdef CONFIG_64BIT
 191         /*
 192          * for 64 bit we always support 64 bit IDAWs with 4k page size only
 193          */
 194         orb->cmd.c64 = 1;
 195         orb->cmd.i2k = 0;
 196 #endif
 197         orb->cmd.key = key >> 4;
 198         /* issue "Start Subchannel" */
 199         orb->cmd.cpa = (__u32) __pa(cpa);
 200         ccode = ssch(sch->schid, orb);
 201
 202         /* process condition code */
 203         sprintf(dbf_txt, "ccode:%d", ccode);
 204         CIO_TRACE_EVENT(4, dbf_txt);
 205
 206         switch (ccode) {
 207         case 0:
 208                 /*
 209                  * initialize device status information
 210                  */
 211                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
 212                 return 0;
 213         case 1:         /* status pending */
 214         case 2:         /* busy */
 215                 return -EBUSY;
 216         case 3:         /* device/path not operational */
 217                 return cio_start_handle_notoper(sch, lpm);
 218         default:
 219                 return ccode;
 220         }
 221 }
 222
 223 int
 224 cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
 225 {
 226         return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
 227 }
 228
 229 /*
 230  * resume suspended I/O operation
 231  */
 232 int
 233 cio_resume (struct subchannel *sch)
 234 {
 235         char dbf_txt[15];
 236         int ccode;
 237
 238         CIO_TRACE_EVENT (4, "resIO");
 239         CIO_TRACE_EVENT(4, dev_name(&sch->dev));
 240
 241         ccode = rsch (sch->schid);
 242
 243         sprintf (dbf_txt, "ccode:%d", ccode);
 244         CIO_TRACE_EVENT (4, dbf_txt);
 245
 246         switch (ccode) {
 247         case 0:
 248                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_RESUME_PEND;
 249                 return 0;
 250         case 1:
 251                 return -EBUSY;
 252         case 2:
 253                 return -EINVAL;
 254         default:
 255                 /*
 256                  * useless to wait for request completion
 257                  *  as device is no longer operational !
 258                  */
 259                 return -ENODEV;
 260         }
 261 }
 262
 263 /*
 264  * halt I/O operation
 265  */
 266 int
 267 cio_halt(struct subchannel *sch)
 268 {
 269         char dbf_txt[15];
 270         int ccode;
 271
 272         if (!sch)
 273                 return -ENODEV;
 274
 275         CIO_TRACE_EVENT (2, "haltIO");
 276         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 277
 278         /*
 279          * Issue "Halt subchannel" and process condition code
 280          */
 281         ccode = hsch (sch->schid);
 282
 283         sprintf (dbf_txt, "ccode:%d", ccode);
 284         CIO_TRACE_EVENT (2, dbf_txt);
 285
 286         switch (ccode) {
 287         case 0:
 288                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND;
 289                 return 0;
 290         case 1:         /* status pending */
 291         case 2:         /* busy */
 292                 return -EBUSY;
 293         default:                /* device not operational */
 294                 return -ENODEV;
 295         }
 296 }
 297
 298 /*
 299  * Clear I/O operation
 300  */
 301 int
 302 cio_clear(struct subchannel *sch)
 303 {
 304         char dbf_txt[15];
 305         int ccode;
 306
 307         if (!sch)
 308                 return -ENODEV;
 309
 310         CIO_TRACE_EVENT (2, "clearIO");
 311         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 312
 313         /*
 314          * Issue "Clear subchannel" and process condition code
 315          */
 316         ccode = csch (sch->schid);
 317
 318         sprintf (dbf_txt, "ccode:%d", ccode);
 319         CIO_TRACE_EVENT (2, dbf_txt);
 320
 321         switch (ccode) {
 322         case 0:
 323                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_CLEAR_PEND;
 324                 return 0;
 325         default:                /* device not operational */
 326                 return -ENODEV;
 327         }
 328 }
 329
 330 /*
 331  * Function: cio_cancel
 332  * Issues a "Cancel Subchannel" on the specified subchannel
 333  * Note: We don't need any fancy intparms and flags here
 334  *       since xsch is executed synchronously.
 335  * Only for common I/O internal use as for now.
 336  */
 337 int
 338 cio_cancel (struct subchannel *sch)
 339 {
 340         char dbf_txt[15];
 341         int ccode;
 342
 343         if (!sch)
 344                 return -ENODEV;
 345
 346         CIO_TRACE_EVENT (2, "cancelIO");
 347         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 348
 349         ccode = xsch (sch->schid);
 350
 351         sprintf (dbf_txt, "ccode:%d", ccode);
 352         CIO_TRACE_EVENT (2, dbf_txt);
 353
 354         switch (ccode) {
 355         case 0:         /* success */
 356                 /* Update information in scsw. */
 357                 stsch (sch->schid, &sch->schib);
 358                 return 0;
 359         case 1:         /* status pending */
 360                 return -EBUSY;
 361         case 2:         /* not applicable */
 362                 return -EINVAL;
 363         default:        /* not oper */
 364                 return -ENODEV;
 365         }
 366 }
 367
 368 /*
 369  * Function: cio_modify
 370  * Issues a "Modify Subchannel" on the specified subchannel
 371  */
 372 int
 373 cio_modify (struct subchannel *sch)
 374 {
 375         int ccode, retry, ret;
 376
 377         ret = 0;
 378         for (retry = 0; retry < 5; retry++) {
 379                 ccode = msch_err (sch->schid, &sch->schib);
 380                 if (ccode < 0)  /* -EIO if msch gets a program check. */
 381                         return ccode;
 382                 switch (ccode) {
 383                 case 0: /* successfull */
 384                         return 0;
 385                 case 1: /* status pending */
 386                         return -EBUSY;
 387                 case 2: /* busy */
 388                         udelay (100);   /* allow for recovery */
 389                         ret = -EBUSY;
 390                         break;
 391                 case 3: /* not operational */
 392                         return -ENODEV;
 393                 }
 394         }
 395         return ret;
 396 }
 397
 398 /**
 399  * cio_enable_subchannel - enable a subchannel.
 400  * @sch: subchannel to be enabled
 401  * @intparm: interruption parameter to set
 402  */
 403 int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
 404 {
 405         char dbf_txt[15];
 406         int ccode;
 407         int retry;
 408         int ret;
 409
 410         CIO_TRACE_EVENT (2, "ensch");
 411         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 412
 413         if (sch_is_pseudo_sch(sch))
 414                 return -EINVAL;
 415         ccode = stsch (sch->schid, &sch->schib);
 416         if (ccode)
 417                 return -ENODEV;
 418
 419         for (retry = 5, ret = 0; retry > 0; retry--) {
 420                 sch->schib.pmcw.ena = 1;
 421                 sch->schib.pmcw.isc = sch->isc;
 422                 sch->schib.pmcw.intparm = intparm;
 423                 ret = cio_modify(sch);
 424                 if (ret == -ENODEV)
 425                         break;
 426                 if (ret == -EIO)
 427                         /*
 428                          * Got a program check in cio_modify. Try without
 429                          * the concurrent sense bit the next time.
 430                          */
 431                         sch->schib.pmcw.csense = 0;
 432                 if (ret == 0) {
 433                         stsch (sch->schid, &sch->schib);
 434                         if (sch->schib.pmcw.ena)
 435                                 break;
 436                 }
 437                 if (ret == -EBUSY) {
 438                         struct irb irb;
 439                         if (tsch(sch->schid, &irb) != 0)
 440                                 break;
 441                 }
 442         }
 443         sprintf (dbf_txt, "ret:%d", ret);
 444         CIO_TRACE_EVENT (2, dbf_txt);
 445         return ret;
 446 }
 447 EXPORT_SYMBOL_GPL(cio_enable_subchannel);
 448
 449 /**
 450  * cio_disable_subchannel - disable a subchannel.
 451  * @sch: subchannel to disable
 452  */
 453 int cio_disable_subchannel(struct subchannel *sch)
 454 {
 455         char dbf_txt[15];
 456         int ccode;
 457         int retry;
 458         int ret;
 459
 460         CIO_TRACE_EVENT (2, "dissch");
 461         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 462
 463         if (sch_is_pseudo_sch(sch))
 464                 return 0;
 465         ccode = stsch (sch->schid, &sch->schib);
 466         if (ccode == 3)         /* Not operational. */
 467                 return -ENODEV;
 468
 469         if (scsw_actl(&sch->schib.scsw) != 0)
 470                 /*
 471                  * the disable function must not be called while there are
 472                  *  requests pending for completion !
 473                  */
 474                 return -EBUSY;
 475
 476         for (retry = 5, ret = 0; retry > 0; retry--) {
 477                 sch->schib.pmcw.ena = 0;
 478                 ret = cio_modify(sch);
 479                 if (ret == -ENODEV)
 480                         break;
 481                 if (ret == -EBUSY)
 482                         /*
 483                          * The subchannel is busy or status pending.
 484                          * We'll disable when the next interrupt was delivered
 485                          * via the state machine.
 486                          */
 487                         break;
 488                 if (ret == 0) {
 489                         stsch (sch->schid, &sch->schib);
 490                         if (!sch->schib.pmcw.ena)
 491                                 break;
 492                 }
 493         }
 494         sprintf (dbf_txt, "ret:%d", ret);
 495         CIO_TRACE_EVENT (2, dbf_txt);
 496         return ret;
 497 }
 498 EXPORT_SYMBOL_GPL(cio_disable_subchannel);
 499
 500 int cio_create_sch_lock(struct subchannel *sch)
 501 {
 502         sch->lock = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
 503         if (!sch->lock)
 504                 return -ENOMEM;
 505         spin_lock_init(sch->lock);
 506         return 0;
 507 }
 508
 509 static int cio_check_devno_blacklisted(struct subchannel *sch)
 510 {
 511         if (is_blacklisted(sch->schid.ssid, sch->schib.pmcw.dev)) {
 512                 /*
 513                  * This device must not be known to Linux. So we simply
 514                  * say that there is no device and return ENODEV.
 515                  */
 516                 CIO_MSG_EVENT(6, "Blacklisted device detected "
 517                               "at devno %04X, subchannel set %x\n",
 518                               sch->schib.pmcw.dev, sch->schid.ssid);
 519                 return -ENODEV;
 520         }
 521         return 0;
 522 }
 523
 524 static int cio_validate_io_subchannel(struct subchannel *sch)
 525 {
 526         /* Initialization for io subchannels. */
 527         if (!css_sch_is_valid(&sch->schib))
 528                 return -ENODEV;
 529
 530         /* Devno is valid. */
 531         return cio_check_devno_blacklisted(sch);
 532 }
 533
 534 static int cio_validate_msg_subchannel(struct subchannel *sch)
 535 {
 536         /* Initialization for message subchannels. */
 537         if (!css_sch_is_valid(&sch->schib))
 538                 return -ENODEV;
 539
 540         /* Devno is valid. */
 541         return cio_check_devno_blacklisted(sch);
 542 }
 543
 544 /**
 545  * cio_validate_subchannel - basic validation of subchannel
 546  * @sch: subchannel structure to be filled out
 547  * @schid: subchannel id
 548  *
 549  * Find out subchannel type and initialize struct subchannel.
 550  * Return codes:
 551  *   0 on success
 552  *   -ENXIO for non-defined subchannels
 553  *   -ENODEV for invalid subchannels or blacklisted devices
 554  *   -EIO for subchannels in an invalid subchannel set
 555  */
 556 int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
 557 {
 558         char dbf_txt[15];
 559         int ccode;
 560         int err;
 561
 562         sprintf(dbf_txt, "valsch%x", schid.sch_no);
 563         CIO_TRACE_EVENT(4, dbf_txt);
 564
 565         /* Nuke all fields. */
 566         memset(sch, 0, sizeof(struct subchannel));
 567
 568         sch->schid = schid;
 569         if (cio_is_console(schid)) {
 570                 sch->lock = cio_get_console_lock();
 571         } else {
 572                 err = cio_create_sch_lock(sch);
 573                 if (err)
 574                         goto out;
 575         }
 576         mutex_init(&sch->reg_mutex);
 577         /* Set a name for the subchannel */
 578         if (cio_is_console(schid))
 579                 sch->dev.init_name = cio_get_console_sch_name(schid);
 580         else
 581                 dev_set_name(&sch->dev, "0.%x.%04x", schid.ssid, schid.sch_no);
 582
 583         /*
 584          * The first subchannel that is not-operational (ccode==3)
 585          *  indicates that there aren't any more devices available.
 586          * If stsch gets an exception, it means the current subchannel set
 587          *  is not valid.
 588          */
 589         ccode = stsch_err (schid, &sch->schib);
 590         if (ccode) {
 591                 err = (ccode == 3) ? -ENXIO : ccode;
 592                 goto out;
 593         }
 594         /* Copy subchannel type from path management control word. */
 595         sch->st = sch->schib.pmcw.st;
 596
 597         switch (sch->st) {
 598         case SUBCHANNEL_TYPE_IO:
 599                 err = cio_validate_io_subchannel(sch);
 600                 break;
 601         case SUBCHANNEL_TYPE_MSG:
 602                 err = cio_validate_msg_subchannel(sch);
 603                 break;
 604         default:
 605                 err = 0;
 606         }
 607         if (err)
 608                 goto out;
 609
 610         CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
 611                       sch->schid.ssid, sch->schid.sch_no, sch->st);
 612         return 0;
 613 out:
 614         if (!cio_is_console(schid))
 615                 kfree(sch->lock);
 616         sch->lock = NULL;
 617         return err;
 618 }
 619
 620 /*
 621  * do_IRQ() handles all normal I/O device IRQ's (the special
 622  *          SMP cross-CPU interrupts have their own specific
 623  *          handlers).
 624  *
 625  */
 626 void
 627 do_IRQ (struct pt_regs *regs)
 628 {
 629         struct tpi_info *tpi_info;
 630         struct subchannel *sch;
 631         struct irb *irb;
 632         struct pt_regs *old_regs;
 633
 634         old_regs = set_irq_regs(regs);
 635         irq_enter();
 636         s390_idle_check();
 637         if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
 638                 /* Serve timer interrupts first. */
 639                 clock_comparator_work();
 640         /*
 641          * Get interrupt information from lowcore
 642          */
 643         tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
 644         irb = (struct irb *) __LC_IRB;
 645         do {
 646                 kstat_cpu(smp_processor_id()).irqs[IO_INTERRUPT]++;
 647                 /*
 648                  * Non I/O-subchannel thin interrupts are processed differently
 649                  */
 650                 if (tpi_info->adapter_IO == 1 &&
 651                     tpi_info->int_type == IO_INTERRUPT_TYPE) {
 652                         do_adapter_IO(tpi_info->isc);
 653                         continue;
 654                 }
 655                 sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 656                 if (!sch) {
 657                         /* Clear pending interrupt condition. */
 658                         tsch(tpi_info->schid, irb);
 659                         continue;
 660                 }
 661                 spin_lock(sch->lock);
 662                 /* Store interrupt response block to lowcore. */
 663                 if (tsch(tpi_info->schid, irb) == 0) {
 664                         /* Keep subchannel information word up to date. */
 665                         memcpy (&sch->schib.scsw, &irb->scsw,
 666                                 sizeof (irb->scsw));
 667                         /* Call interrupt handler if there is one. */
 668                         if (sch->driver && sch->driver->irq)
 669                                 sch->driver->irq(sch);
 670                 }
 671                 spin_unlock(sch->lock);
 672                 /*
 673                  * Are more interrupts pending?
 674                  * If so, the tpi instruction will update the lowcore
 675                  * to hold the info for the next interrupt.
 676                  * We don't do this for VM because a tpi drops the cpu
 677                  * out of the sie which costs more cycles than it saves.
 678                  */
 679         } while (!MACHINE_IS_VM && tpi (NULL) != 0);
 680         irq_exit();
 681         set_irq_regs(old_regs);
 682 }
 683
 684 #ifdef CONFIG_CCW_CONSOLE
 685 static struct subchannel console_subchannel;
 686 static char console_sch_name[10] = "0.x.xxxx";
 687 static struct io_subchannel_private console_priv;
 688 static int console_subchannel_in_use;
 689
 690 void *cio_get_console_priv(void)
 691 {
 692         return &console_priv;
 693 }
 694
 695 /*
 696  * busy wait for the next interrupt on the console
 697  */
 698 void wait_cons_dev(void)
 699         __releases(console_subchannel.lock)
 700         __acquires(console_subchannel.lock)
 701 {
 702         unsigned long cr6      __attribute__ ((aligned (8)));
 703         unsigned long save_cr6 __attribute__ ((aligned (8)));
 704
 705         /*
 706          * before entering the spinlock we may already have
 707          * processed the interrupt on a different CPU...
 708          */
 709         if (!console_subchannel_in_use)
 710                 return;
 711
 712         /* disable all but the console isc */
 713         __ctl_store (save_cr6, 6, 6);
 714         cr6 = 1UL << (31 - CONSOLE_ISC);
 715         __ctl_load (cr6, 6, 6);
 716
 717         do {
 718                 spin_unlock(console_subchannel.lock);
 719                 if (!cio_tpi())
 720                         cpu_relax();
 721                 spin_lock(console_subchannel.lock);
 722         } while (console_subchannel.schib.scsw.cmd.actl != 0);
 723         /*
 724          * restore previous isc value
 725          */
 726         __ctl_load (save_cr6, 6, 6);
 727 }
 728
 729 static int
 730 cio_test_for_console(struct subchannel_id schid, void *data)
 731 {
 732         if (stsch_err(schid, &console_subchannel.schib) != 0)
 733                 return -ENXIO;
 734         if ((console_subchannel.schib.pmcw.st == SUBCHANNEL_TYPE_IO) &&
 735             console_subchannel.schib.pmcw.dnv &&
 736             (console_subchannel.schib.pmcw.dev == console_devno)) {
 737                 console_irq = schid.sch_no;
 738                 return 1; /* found */
 739         }
 740         return 0;
 741 }
 742
 743
 744 static int
 745 cio_get_console_sch_no(void)
 746 {
 747         struct subchannel_id schid;
 748
 749         init_subchannel_id(&schid);
 750         if (console_irq != -1) {
 751                 /* VM provided us with the irq number of the console. */
 752                 schid.sch_no = console_irq;
 753                 if (stsch(schid, &console_subchannel.schib) != 0 ||
 754                     (console_subchannel.schib.pmcw.st != SUBCHANNEL_TYPE_IO) ||
 755                     !console_subchannel.schib.pmcw.dnv)
 756                         return -1;
 757                 console_devno = console_subchannel.schib.pmcw.dev;
 758         } else if (console_devno != -1) {
 759                 /* At least the console device number is known. */
 760                 for_each_subchannel(cio_test_for_console, NULL);
 761                 if (console_irq == -1)
 762                         return -1;
 763         } else {
 764                 /* unlike in 2.4, we cannot autoprobe here, since
 765                  * the channel subsystem is not fully initialized.
 766                  * With some luck, the HWC console can take over */
 767                 return -1;
 768         }
 769         return console_irq;
 770 }
 771
 772 struct subchannel *
 773 cio_probe_console(void)
 774 {
 775         int sch_no, ret;
 776         struct subchannel_id schid;
 777
 778         if (xchg(&console_subchannel_in_use, 1) != 0)
 779                 return ERR_PTR(-EBUSY);
 780         sch_no = cio_get_console_sch_no();
 781         if (sch_no == -1) {
 782                 console_subchannel_in_use = 0;
 783                 printk(KERN_WARNING "cio: No ccw console found!\n");
 784                 return ERR_PTR(-ENODEV);
 785         }
 786         memset(&console_subchannel, 0, sizeof(struct subchannel));
 787         init_subchannel_id(&schid);
 788         schid.sch_no = sch_no;
 789         ret = cio_validate_subchannel(&console_subchannel, schid);
 790         if (ret) {
 791                 console_subchannel_in_use = 0;
 792                 return ERR_PTR(-ENODEV);
 793         }
 794
 795         /*
 796          * enable console I/O-interrupt subclass
 797          */
 798         isc_register(CONSOLE_ISC);
 799         console_subchannel.schib.pmcw.isc = CONSOLE_ISC;
 800         console_subchannel.schib.pmcw.intparm =
 801                 (u32)(addr_t)&console_subchannel;
 802         ret = cio_modify(&console_subchannel);
 803         if (ret) {
 804                 isc_unregister(CONSOLE_ISC);
 805                 console_subchannel_in_use = 0;
 806                 return ERR_PTR(ret);
 807         }
 808         return &console_subchannel;
 809 }
 810
 811 void
 812 cio_release_console(void)
 813 {
 814         console_subchannel.schib.pmcw.intparm = 0;
 815         cio_modify(&console_subchannel);
 816         isc_unregister(CONSOLE_ISC);
 817         console_subchannel_in_use = 0;
 818 }
 819
 820 /* Bah... hack to catch console special sausages. */
 821 int
 822 cio_is_console(struct subchannel_id schid)
 823 {
 824         if (!console_subchannel_in_use)
 825                 return 0;
 826         return schid_equal(&schid, &console_subchannel.schid);
 827 }
 828
 829 struct subchannel *
 830 cio_get_console_subchannel(void)
 831 {
 832         if (!console_subchannel_in_use)
 833                 return NULL;
 834         return &console_subchannel;
 835 }
 836
 837 const char *cio_get_console_sch_name(struct subchannel_id schid)
 838 {
 839         snprintf(console_sch_name, 10, "0.%x.%04x", schid.ssid, schid.sch_no);
 840         return (const char *)console_sch_name;
 841 }
 842
 843 #endif
 844 static int
 845 __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
 846 {
 847         int retry, cc;
 848
 849         cc = 0;
 850         for (retry=0;retry<3;retry++) {
 851                 schib->pmcw.ena = 0;
 852                 cc = msch(schid, schib);
 853                 if (cc)
 854                         return (cc==3?-ENODEV:-EBUSY);
 855                 stsch(schid, schib);
 856                 if (!schib->pmcw.ena)
 857                         return 0;
 858         }
 859         return -EBUSY; /* uhm... */
 860 }
 861
 862 static int
 863 __clear_io_subchannel_easy(struct subchannel_id schid)
 864 {
 865         int retry;
 866
 867         if (csch(schid))
 868                 return -ENODEV;
 869         for (retry=0;retry<20;retry++) {
 870                 struct tpi_info ti;
 871
 872                 if (tpi(&ti)) {
 873                         tsch(ti.schid, (struct irb *)__LC_IRB);
 874                         if (schid_equal(&ti.schid, &schid))
 875                                 return 0;
 876                 }
 877                 udelay_simple(100);
 878         }
 879         return -EBUSY;
 880 }
 881
 882 static void __clear_chsc_subchannel_easy(void)
 883 {
 884         /* It seems we can only wait for a bit here :/ */
 885         udelay_simple(100);
 886 }
 887
 888 static int pgm_check_occured;
 889
 890 static void cio_reset_pgm_check_handler(void)
 891 {
 892         pgm_check_occured = 1;
 893 }
 894
 895 static int stsch_reset(struct subchannel_id schid, struct schib *addr)
 896 {
 897         int rc;
 898
 899         pgm_check_occured = 0;
 900         s390_base_pgm_handler_fn = cio_reset_pgm_check_handler;
 901         rc = stsch(schid, addr);
 902         s390_base_pgm_handler_fn = NULL;
 903
 904         /* The program check handler could have changed pgm_check_occured. */
 905         barrier();
 906
 907         if (pgm_check_occured)
 908                 return -EIO;
 909         else
 910                 return rc;
 911 }
 912
 913 static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
 914 {
 915         struct schib schib;
 916
 917         if (stsch_reset(schid, &schib))
 918                 return -ENXIO;
 919         if (!schib.pmcw.ena)
 920                 return 0;
 921         switch(__disable_subchannel_easy(schid, &schib)) {
 922         case 0:
 923         case -ENODEV:
 924                 break;
 925         default: /* -EBUSY */
 926                 switch (schib.pmcw.st) {
 927                 case SUBCHANNEL_TYPE_IO:
 928                         if (__clear_io_subchannel_easy(schid))
 929                                 goto out; /* give up... */
 930                         break;
 931                 case SUBCHANNEL_TYPE_CHSC:
 932                         __clear_chsc_subchannel_easy();
 933                         break;
 934                 default:
 935                         /* No default clear strategy */
 936                         break;
 937                 }
 938                 stsch(schid, &schib);
 939                 __disable_subchannel_easy(schid, &schib);
 940         }
 941 out:
 942         return 0;
 943 }
 944
 945 static atomic_t chpid_reset_count;
 946
 947 static void s390_reset_chpids_mcck_handler(void)
 948 {
 949         struct crw crw;
 950         struct mci *mci;
 951
 952         /* Check for pending channel report word. */
 953         mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
 954         if (!mci->cp)
 955                 return;
 956         /* Process channel report words. */
 957         while (stcrw(&crw) == 0) {
 958                 /* Check for responses to RCHP. */
 959                 if (crw.slct && crw.rsc == CRW_RSC_CPATH)
 960                         atomic_dec(&chpid_reset_count);
 961         }
 962 }
 963
 964 #define RCHP_TIMEOUT (30 * USEC_PER_SEC)
 965 static void css_reset(void)
 966 {
 967         int i, ret;
 968         unsigned long long timeout;
 969         struct chp_id chpid;
 970
 971         /* Reset subchannels. */
 972         for_each_subchannel(__shutdown_subchannel_easy,  NULL);
 973         /* Reset channel paths. */
 974         s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler;
 975         /* Enable channel report machine checks. */
 976         __ctl_set_bit(14, 28);
 977         /* Temporarily reenable machine checks. */
 978         local_mcck_enable();
 979         chp_id_init(&chpid);
 980         for (i = 0; i <= __MAX_CHPID; i++) {
 981                 chpid.id = i;
 982                 ret = rchp(chpid);
 983                 if ((ret == 0) || (ret == 2))
 984                         /*
 985                          * rchp either succeeded, or another rchp is already
 986                          * in progress. In either case, we'll get a crw.
 987                          */
 988                         atomic_inc(&chpid_reset_count);
 989         }
 990         /* Wait for machine check for all channel paths. */
 991         timeout = get_clock() + (RCHP_TIMEOUT << 12);
 992         while (atomic_read(&chpid_reset_count) != 0) {
 993                 if (get_clock() > timeout)
 994                         break;
 995                 cpu_relax();
 996         }
 997         /* Disable machine checks again. */
 998         local_mcck_disable();
 999         /* Disable channel report machine checks. */
1000         __ctl_clear_bit(14, 28);
1001         s390_base_mcck_handler_fn = NULL;
1002 }
1003
1004 static struct reset_call css_reset_call = {
1005         .fn = css_reset,
1006 };
1007
1008 static int __init init_css_reset_call(void)
1009 {
1010         atomic_set(&chpid_reset_count, 0);
1011         register_reset_call(&css_reset_call);
1012         return 0;
1013 }
1014
1015 arch_initcall(init_css_reset_call);
1016
1017 struct sch_match_id {
1018         struct subchannel_id schid;
1019         struct ccw_dev_id devid;
1020         int rc;
1021 };
1022
1023 static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
1024 {
1025         struct schib schib;
1026         struct sch_match_id *match_id = data;
1027
1028         if (stsch_reset(schid, &schib))
1029                 return -ENXIO;
1030         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
1031             (schib.pmcw.dev == match_id->devid.devno) &&
1032             (schid.ssid == match_id->devid.ssid)) {
1033                 match_id->schid = schid;
1034                 match_id->rc = 0;
1035                 return 1;
1036         }
1037         return 0;
1038 }
1039
1040 static int reipl_find_schid(struct ccw_dev_id *devid,
1041                             struct subchannel_id *schid)
1042 {
1043         struct sch_match_id match_id;
1044
1045         match_id.devid = *devid;
1046         match_id.rc = -ENODEV;
1047         for_each_subchannel(__reipl_subchannel_match, &match_id);
1048         if (match_id.rc == 0)
1049                 *schid = match_id.schid;
1050         return match_id.rc;
1051 }
1052
1053 extern void do_reipl_asm(__u32 schid);
1054
1055 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
1056 void reipl_ccw_dev(struct ccw_dev_id *devid)
1057 {
1058         struct subchannel_id schid;
1059
1060         s390_reset_system();
1061         if (reipl_find_schid(devid, &schid) != 0)
1062                 panic("IPL Device not found\n");
1063         do_reipl_asm(*((__u32*)&schid));
1064 }
1065
1066 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
1067 {
1068         struct subchannel_id schid;
1069         struct schib schib;
1070
1071         schid = *(struct subchannel_id *)__LC_SUBCHANNEL_ID;
1072         if (!schid.one)
1073                 return -ENODEV;
1074         if (stsch(schid, &schib))
1075                 return -ENODEV;
1076         if (schib.pmcw.st != SUBCHANNEL_TYPE_IO)
1077                 return -ENODEV;
1078         if (!schib.pmcw.dnv)
1079                 return -ENODEV;
1080         iplinfo->devno = schib.pmcw.dev;
1081         iplinfo->is_qdio = schib.pmcw.qf;
1082         return 0;
1083 }
1084
1085 /**
1086  * cio_tm_start_key - perform start function
1087  * @sch: subchannel on which to perform the start function
1088  * @tcw: transport-command word to be started
1089  * @lpm: mask of paths to use
1090  * @key: storage key to use for storage access
1091  *
1092  * Start the tcw on the given subchannel. Return zero on success, non-zero
1093  * otherwise.
1094  */
1095 int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
1096 {
1097         int cc;
1098         union orb *orb = &to_io_private(sch)->orb;
1099
1100         memset(orb, 0, sizeof(union orb));
1101         orb->tm.intparm = (u32) (addr_t) sch;
1102         orb->tm.key = key >> 4;
1103         orb->tm.b = 1;
1104         orb->tm.lpm = lpm ? lpm : sch->lpm;
1105         orb->tm.tcw = (u32) (addr_t) tcw;
1106         cc = ssch(sch->schid, orb);
1107         switch (cc) {
1108         case 0:
1109                 return 0;
1110         case 1:
1111         case 2:
1112                 return -EBUSY;
1113         default:
1114                 return cio_start_handle_notoper(sch, lpm);
1115         }
1116 }
1117
1118 /**
1119  * cio_tm_intrg - perform interrogate function
1120  * @sch - subchannel on which to perform the interrogate function
1121  *
1122  * If the specified subchannel is running in transport-mode, perform the
1123  * interrogate function. Return zero on success, non-zero otherwie.
1124  */
1125 int cio_tm_intrg(struct subchannel *sch)
1126 {
1127         int cc;
1128
1129         if (!to_io_private(sch)->orb.tm.b)
1130                 return -EINVAL;
1131         cc = xsch(sch->schid);
1132         switch (cc) {
1133         case 0:
1134         case 2:
1135                 return 0;
1136         case 1:
1137                 return -EBUSY;
1138         default:
1139                 return -ENODEV;
1140         }
1141 }