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         printk(KERN_WARNING"cio: could not initialize debugging\n");
  78         return -1;
  79 }
  80
  81 arch_initcall (cio_debug_init);
  82
  83 int
  84 cio_set_options (struct subchannel *sch, int flags)
  85 {
  86        sch->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
  87        sch->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
  88        sch->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
  89        return 0;
  90 }
  91
  92 /* FIXME: who wants to use this? */
  93 int
  94 cio_get_options (struct subchannel *sch)
  95 {
  96        int flags;
  97
  98        flags = 0;
  99        if (sch->options.suspend)
 100                 flags |= DOIO_ALLOW_SUSPEND;
 101        if (sch->options.prefetch)
 102                 flags |= DOIO_DENY_PREFETCH;
 103        if (sch->options.inter)
 104                 flags |= DOIO_SUPPRESS_INTER;
 105        return flags;
 106 }
 107
 108 /*
 109  * Use tpi to get a pending interrupt, call the interrupt handler and
 110  * return a pointer to the subchannel structure.
 111  */
 112 static int
 113 cio_tpi(void)
 114 {
 115         struct tpi_info *tpi_info;
 116         struct subchannel *sch;
 117         struct irb *irb;
 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         local_bh_disable();
 131         irq_enter ();
 132         spin_lock(sch->lock);
 133         memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
 134         if (sch->driver && sch->driver->irq)
 135                 sch->driver->irq(sch);
 136         spin_unlock(sch->lock);
 137         irq_exit ();
 138         _local_bh_enable();
 139         return 1;
 140 }
 141
 142 static int
 143 cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
 144 {
 145         char dbf_text[15];
 146
 147         if (lpm != 0)
 148                 sch->lpm &= ~lpm;
 149         else
 150                 sch->lpm = 0;
 151
 152         stsch (sch->schid, &sch->schib);
 153
 154         CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
 155                       "subchannel 0.%x.%04x!\n", sch->schid.ssid,
 156                       sch->schid.sch_no);
 157         sprintf(dbf_text, "no%s", sch->dev.bus_id);
 158         CIO_TRACE_EVENT(0, dbf_text);
 159         CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
 160
 161         return (sch->lpm ? -EACCES : -ENODEV);
 162 }
 163
 164 int
 165 cio_start_key (struct subchannel *sch,  /* subchannel structure */
 166                struct ccw1 * cpa,       /* logical channel prog addr */
 167                __u8 lpm,                /* logical path mask */
 168                __u8 key)                /* storage key */
 169 {
 170         char dbf_txt[15];
 171         int ccode;
 172         union orb *orb;
 173
 174         CIO_TRACE_EVENT(4, "stIO");
 175         CIO_TRACE_EVENT(4, sch->dev.bus_id);
 176
 177         orb = &to_io_private(sch)->orb;
 178         /* sch is always under 2G. */
 179         orb->cmd.intparm = (u32)(addr_t)sch;
 180         orb->cmd.fmt = 1;
 181
 182         orb->cmd.pfch = sch->options.prefetch == 0;
 183         orb->cmd.spnd = sch->options.suspend;
 184         orb->cmd.ssic = sch->options.suspend && sch->options.inter;
 185         orb->cmd.lpm = (lpm != 0) ? lpm : sch->lpm;
 186 #ifdef CONFIG_64BIT
 187         /*
 188          * for 64 bit we always support 64 bit IDAWs with 4k page size only
 189          */
 190         orb->cmd.c64 = 1;
 191         orb->cmd.i2k = 0;
 192 #endif
 193         orb->cmd.key = key >> 4;
 194         /* issue "Start Subchannel" */
 195         orb->cmd.cpa = (__u32) __pa(cpa);
 196         ccode = ssch(sch->schid, orb);
 197
 198         /* process condition code */
 199         sprintf(dbf_txt, "ccode:%d", ccode);
 200         CIO_TRACE_EVENT(4, dbf_txt);
 201
 202         switch (ccode) {
 203         case 0:
 204                 /*
 205                  * initialize device status information
 206                  */
 207                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
 208                 return 0;
 209         case 1:         /* status pending */
 210         case 2:         /* busy */
 211                 return -EBUSY;
 212         default:                /* device/path not operational */
 213                 return cio_start_handle_notoper(sch, lpm);
 214         }
 215 }
 216
 217 int
 218 cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
 219 {
 220         return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
 221 }
 222
 223 /*
 224  * resume suspended I/O operation
 225  */
 226 int
 227 cio_resume (struct subchannel *sch)
 228 {
 229         char dbf_txt[15];
 230         int ccode;
 231
 232         CIO_TRACE_EVENT (4, "resIO");
 233         CIO_TRACE_EVENT (4, sch->dev.bus_id);
 234
 235         ccode = rsch (sch->schid);
 236
 237         sprintf (dbf_txt, "ccode:%d", ccode);
 238         CIO_TRACE_EVENT (4, dbf_txt);
 239
 240         switch (ccode) {
 241         case 0:
 242                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_RESUME_PEND;
 243                 return 0;
 244         case 1:
 245                 return -EBUSY;
 246         case 2:
 247                 return -EINVAL;
 248         default:
 249                 /*
 250                  * useless to wait for request completion
 251                  *  as device is no longer operational !
 252                  */
 253                 return -ENODEV;
 254         }
 255 }
 256
 257 /*
 258  * halt I/O operation
 259  */
 260 int
 261 cio_halt(struct subchannel *sch)
 262 {
 263         char dbf_txt[15];
 264         int ccode;
 265
 266         if (!sch)
 267                 return -ENODEV;
 268
 269         CIO_TRACE_EVENT (2, "haltIO");
 270         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 271
 272         /*
 273          * Issue "Halt subchannel" and process condition code
 274          */
 275         ccode = hsch (sch->schid);
 276
 277         sprintf (dbf_txt, "ccode:%d", ccode);
 278         CIO_TRACE_EVENT (2, dbf_txt);
 279
 280         switch (ccode) {
 281         case 0:
 282                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND;
 283                 return 0;
 284         case 1:         /* status pending */
 285         case 2:         /* busy */
 286                 return -EBUSY;
 287         default:                /* device not operational */
 288                 return -ENODEV;
 289         }
 290 }
 291
 292 /*
 293  * Clear I/O operation
 294  */
 295 int
 296 cio_clear(struct subchannel *sch)
 297 {
 298         char dbf_txt[15];
 299         int ccode;
 300
 301         if (!sch)
 302                 return -ENODEV;
 303
 304         CIO_TRACE_EVENT (2, "clearIO");
 305         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 306
 307         /*
 308          * Issue "Clear subchannel" and process condition code
 309          */
 310         ccode = csch (sch->schid);
 311
 312         sprintf (dbf_txt, "ccode:%d", ccode);
 313         CIO_TRACE_EVENT (2, dbf_txt);
 314
 315         switch (ccode) {
 316         case 0:
 317                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_CLEAR_PEND;
 318                 return 0;
 319         default:                /* device not operational */
 320                 return -ENODEV;
 321         }
 322 }
 323
 324 /*
 325  * Function: cio_cancel
 326  * Issues a "Cancel Subchannel" on the specified subchannel
 327  * Note: We don't need any fancy intparms and flags here
 328  *       since xsch is executed synchronously.
 329  * Only for common I/O internal use as for now.
 330  */
 331 int
 332 cio_cancel (struct subchannel *sch)
 333 {
 334         char dbf_txt[15];
 335         int ccode;
 336
 337         if (!sch)
 338                 return -ENODEV;
 339
 340         CIO_TRACE_EVENT (2, "cancelIO");
 341         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 342
 343         ccode = xsch (sch->schid);
 344
 345         sprintf (dbf_txt, "ccode:%d", ccode);
 346         CIO_TRACE_EVENT (2, dbf_txt);
 347
 348         switch (ccode) {
 349         case 0:         /* success */
 350                 /* Update information in scsw. */
 351                 stsch (sch->schid, &sch->schib);
 352                 return 0;
 353         case 1:         /* status pending */
 354                 return -EBUSY;
 355         case 2:         /* not applicable */
 356                 return -EINVAL;
 357         default:        /* not oper */
 358                 return -ENODEV;
 359         }
 360 }
 361
 362 /*
 363  * Function: cio_modify
 364  * Issues a "Modify Subchannel" on the specified subchannel
 365  */
 366 int
 367 cio_modify (struct subchannel *sch)
 368 {
 369         int ccode, retry, ret;
 370
 371         ret = 0;
 372         for (retry = 0; retry < 5; retry++) {
 373                 ccode = msch_err (sch->schid, &sch->schib);
 374                 if (ccode < 0)  /* -EIO if msch gets a program check. */
 375                         return ccode;
 376                 switch (ccode) {
 377                 case 0: /* successfull */
 378                         return 0;
 379                 case 1: /* status pending */
 380                         return -EBUSY;
 381                 case 2: /* busy */
 382                         udelay (100);   /* allow for recovery */
 383                         ret = -EBUSY;
 384                         break;
 385                 case 3: /* not operational */
 386                         return -ENODEV;
 387                 }
 388         }
 389         return ret;
 390 }
 391
 392 /**
 393  * cio_enable_subchannel - enable a subchannel.
 394  * @sch: subchannel to be enabled
 395  * @intparm: interruption parameter to set
 396  */
 397 int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
 398 {
 399         char dbf_txt[15];
 400         int ccode;
 401         int retry;
 402         int ret;
 403
 404         CIO_TRACE_EVENT (2, "ensch");
 405         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 406
 407         if (sch_is_pseudo_sch(sch))
 408                 return -EINVAL;
 409         ccode = stsch (sch->schid, &sch->schib);
 410         if (ccode)
 411                 return -ENODEV;
 412
 413         for (retry = 5, ret = 0; retry > 0; retry--) {
 414                 sch->schib.pmcw.ena = 1;
 415                 sch->schib.pmcw.isc = sch->isc;
 416                 sch->schib.pmcw.intparm = intparm;
 417                 ret = cio_modify(sch);
 418                 if (ret == -ENODEV)
 419                         break;
 420                 if (ret == -EIO)
 421                         /*
 422                          * Got a program check in cio_modify. Try without
 423                          * the concurrent sense bit the next time.
 424                          */
 425                         sch->schib.pmcw.csense = 0;
 426                 if (ret == 0) {
 427                         stsch (sch->schid, &sch->schib);
 428                         if (sch->schib.pmcw.ena)
 429                                 break;
 430                 }
 431                 if (ret == -EBUSY) {
 432                         struct irb irb;
 433                         if (tsch(sch->schid, &irb) != 0)
 434                                 break;
 435                 }
 436         }
 437         sprintf (dbf_txt, "ret:%d", ret);
 438         CIO_TRACE_EVENT (2, dbf_txt);
 439         return ret;
 440 }
 441 EXPORT_SYMBOL_GPL(cio_enable_subchannel);
 442
 443 /**
 444  * cio_disable_subchannel - disable a subchannel.
 445  * @sch: subchannel to disable
 446  */
 447 int cio_disable_subchannel(struct subchannel *sch)
 448 {
 449         char dbf_txt[15];
 450         int ccode;
 451         int retry;
 452         int ret;
 453
 454         CIO_TRACE_EVENT (2, "dissch");
 455         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 456
 457         if (sch_is_pseudo_sch(sch))
 458                 return 0;
 459         ccode = stsch (sch->schid, &sch->schib);
 460         if (ccode == 3)         /* Not operational. */
 461                 return -ENODEV;
 462
 463         if (scsw_actl(&sch->schib.scsw) != 0)
 464                 /*
 465                  * the disable function must not be called while there are
 466                  *  requests pending for completion !
 467                  */
 468                 return -EBUSY;
 469
 470         for (retry = 5, ret = 0; retry > 0; retry--) {
 471                 sch->schib.pmcw.ena = 0;
 472                 ret = cio_modify(sch);
 473                 if (ret == -ENODEV)
 474                         break;
 475                 if (ret == -EBUSY)
 476                         /*
 477                          * The subchannel is busy or status pending.
 478                          * We'll disable when the next interrupt was delivered
 479                          * via the state machine.
 480                          */
 481                         break;
 482                 if (ret == 0) {
 483                         stsch (sch->schid, &sch->schib);
 484                         if (!sch->schib.pmcw.ena)
 485                                 break;
 486                 }
 487         }
 488         sprintf (dbf_txt, "ret:%d", ret);
 489         CIO_TRACE_EVENT (2, dbf_txt);
 490         return ret;
 491 }
 492 EXPORT_SYMBOL_GPL(cio_disable_subchannel);
 493
 494 int cio_create_sch_lock(struct subchannel *sch)
 495 {
 496         sch->lock = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
 497         if (!sch->lock)
 498                 return -ENOMEM;
 499         spin_lock_init(sch->lock);
 500         return 0;
 501 }
 502
 503 static int cio_check_devno_blacklisted(struct subchannel *sch)
 504 {
 505         if (is_blacklisted(sch->schid.ssid, sch->schib.pmcw.dev)) {
 506                 /*
 507                  * This device must not be known to Linux. So we simply
 508                  * say that there is no device and return ENODEV.
 509                  */
 510                 CIO_MSG_EVENT(6, "Blacklisted device detected "
 511                               "at devno %04X, subchannel set %x\n",
 512                               sch->schib.pmcw.dev, sch->schid.ssid);
 513                 return -ENODEV;
 514         }
 515         return 0;
 516 }
 517
 518 static int cio_validate_io_subchannel(struct subchannel *sch)
 519 {
 520         /* Initialization for io subchannels. */
 521         if (!css_sch_is_valid(&sch->schib))
 522                 return -ENODEV;
 523
 524         /* Devno is valid. */
 525         return cio_check_devno_blacklisted(sch);
 526 }
 527
 528 static int cio_validate_msg_subchannel(struct subchannel *sch)
 529 {
 530         /* Initialization for message subchannels. */
 531         if (!css_sch_is_valid(&sch->schib))
 532                 return -ENODEV;
 533
 534         /* Devno is valid. */
 535         return cio_check_devno_blacklisted(sch);
 536 }
 537
 538 /**
 539  * cio_validate_subchannel - basic validation of subchannel
 540  * @sch: subchannel structure to be filled out
 541  * @schid: subchannel id
 542  *
 543  * Find out subchannel type and initialize struct subchannel.
 544  * Return codes:
 545  *   0 on success
 546  *   -ENXIO for non-defined subchannels
 547  *   -ENODEV for invalid subchannels or blacklisted devices
 548  *   -EIO for subchannels in an invalid subchannel set
 549  */
 550 int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
 551 {
 552         char dbf_txt[15];
 553         int ccode;
 554         int err;
 555
 556         sprintf(dbf_txt, "valsch%x", schid.sch_no);
 557         CIO_TRACE_EVENT(4, dbf_txt);
 558
 559         /* Nuke all fields. */
 560         memset(sch, 0, sizeof(struct subchannel));
 561
 562         sch->schid = schid;
 563         if (cio_is_console(schid)) {
 564                 sch->lock = cio_get_console_lock();
 565         } else {
 566                 err = cio_create_sch_lock(sch);
 567                 if (err)
 568                         goto out;
 569         }
 570         mutex_init(&sch->reg_mutex);
 571         /* Set a name for the subchannel */
 572         snprintf (sch->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x", schid.ssid,
 573                   schid.sch_no);
 574
 575         /*
 576          * The first subchannel that is not-operational (ccode==3)
 577          *  indicates that there aren't any more devices available.
 578          * If stsch gets an exception, it means the current subchannel set
 579          *  is not valid.
 580          */
 581         ccode = stsch_err (schid, &sch->schib);
 582         if (ccode) {
 583                 err = (ccode == 3) ? -ENXIO : ccode;
 584                 goto out;
 585         }
 586         /* Copy subchannel type from path management control word. */
 587         sch->st = sch->schib.pmcw.st;
 588
 589         switch (sch->st) {
 590         case SUBCHANNEL_TYPE_IO:
 591                 err = cio_validate_io_subchannel(sch);
 592                 break;
 593         case SUBCHANNEL_TYPE_MSG:
 594                 err = cio_validate_msg_subchannel(sch);
 595                 break;
 596         default:
 597                 err = 0;
 598         }
 599         if (err)
 600                 goto out;
 601
 602         CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
 603                       sch->schid.ssid, sch->schid.sch_no, sch->st);
 604         return 0;
 605 out:
 606         if (!cio_is_console(schid))
 607                 kfree(sch->lock);
 608         sch->lock = NULL;
 609         return err;
 610 }
 611
 612 /*
 613  * do_IRQ() handles all normal I/O device IRQ's (the special
 614  *          SMP cross-CPU interrupts have their own specific
 615  *          handlers).
 616  *
 617  */
 618 void
 619 do_IRQ (struct pt_regs *regs)
 620 {
 621         struct tpi_info *tpi_info;
 622         struct subchannel *sch;
 623         struct irb *irb;
 624         struct pt_regs *old_regs;
 625
 626         old_regs = set_irq_regs(regs);
 627         irq_enter();
 628         s390_idle_check();
 629         if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
 630                 /* Serve timer interrupts first. */
 631                 clock_comparator_work();
 632         /*
 633          * Get interrupt information from lowcore
 634          */
 635         tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
 636         irb = (struct irb *) __LC_IRB;
 637         do {
 638                 kstat_cpu(smp_processor_id()).irqs[IO_INTERRUPT]++;
 639                 /*
 640                  * Non I/O-subchannel thin interrupts are processed differently
 641                  */
 642                 if (tpi_info->adapter_IO == 1 &&
 643                     tpi_info->int_type == IO_INTERRUPT_TYPE) {
 644                         do_adapter_IO(tpi_info->isc);
 645                         continue;
 646                 }
 647                 sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 648                 if (!sch) {
 649                         /* Clear pending interrupt condition. */
 650                         tsch(tpi_info->schid, irb);
 651                         continue;
 652                 }
 653                 spin_lock(sch->lock);
 654                 /* Store interrupt response block to lowcore. */
 655                 if (tsch(tpi_info->schid, irb) == 0) {
 656                         /* Keep subchannel information word up to date. */
 657                         memcpy (&sch->schib.scsw, &irb->scsw,
 658                                 sizeof (irb->scsw));
 659                         /* Call interrupt handler if there is one. */
 660                         if (sch->driver && sch->driver->irq)
 661                                 sch->driver->irq(sch);
 662                 }
 663                 spin_unlock(sch->lock);
 664                 /*
 665                  * Are more interrupts pending?
 666                  * If so, the tpi instruction will update the lowcore
 667                  * to hold the info for the next interrupt.
 668                  * We don't do this for VM because a tpi drops the cpu
 669                  * out of the sie which costs more cycles than it saves.
 670                  */
 671         } while (!MACHINE_IS_VM && tpi (NULL) != 0);
 672         irq_exit();
 673         set_irq_regs(old_regs);
 674 }
 675
 676 #ifdef CONFIG_CCW_CONSOLE
 677 static struct subchannel console_subchannel;
 678 static struct io_subchannel_private console_priv;
 679 static int console_subchannel_in_use;
 680
 681 void *cio_get_console_priv(void)
 682 {
 683         return &console_priv;
 684 }
 685
 686 /*
 687  * busy wait for the next interrupt on the console
 688  */
 689 void wait_cons_dev(void)
 690         __releases(console_subchannel.lock)
 691         __acquires(console_subchannel.lock)
 692 {
 693         unsigned long cr6      __attribute__ ((aligned (8)));
 694         unsigned long save_cr6 __attribute__ ((aligned (8)));
 695
 696         /*
 697          * before entering the spinlock we may already have
 698          * processed the interrupt on a different CPU...
 699          */
 700         if (!console_subchannel_in_use)
 701                 return;
 702
 703         /* disable all but the console isc */
 704         __ctl_store (save_cr6, 6, 6);
 705         cr6 = 1UL << (31 - CONSOLE_ISC);
 706         __ctl_load (cr6, 6, 6);
 707
 708         do {
 709                 spin_unlock(console_subchannel.lock);
 710                 if (!cio_tpi())
 711                         cpu_relax();
 712                 spin_lock(console_subchannel.lock);
 713         } while (console_subchannel.schib.scsw.cmd.actl != 0);
 714         /*
 715          * restore previous isc value
 716          */
 717         __ctl_load (save_cr6, 6, 6);
 718 }
 719
 720 static int
 721 cio_test_for_console(struct subchannel_id schid, void *data)
 722 {
 723         if (stsch_err(schid, &console_subchannel.schib) != 0)
 724                 return -ENXIO;
 725         if ((console_subchannel.schib.pmcw.st == SUBCHANNEL_TYPE_IO) &&
 726             console_subchannel.schib.pmcw.dnv &&
 727             (console_subchannel.schib.pmcw.dev == console_devno)) {
 728                 console_irq = schid.sch_no;
 729                 return 1; /* found */
 730         }
 731         return 0;
 732 }
 733
 734
 735 static int
 736 cio_get_console_sch_no(void)
 737 {
 738         struct subchannel_id schid;
 739
 740         init_subchannel_id(&schid);
 741         if (console_irq != -1) {
 742                 /* VM provided us with the irq number of the console. */
 743                 schid.sch_no = console_irq;
 744                 if (stsch(schid, &console_subchannel.schib) != 0 ||
 745                     (console_subchannel.schib.pmcw.st != SUBCHANNEL_TYPE_IO) ||
 746                     !console_subchannel.schib.pmcw.dnv)
 747                         return -1;
 748                 console_devno = console_subchannel.schib.pmcw.dev;
 749         } else if (console_devno != -1) {
 750                 /* At least the console device number is known. */
 751                 for_each_subchannel(cio_test_for_console, NULL);
 752                 if (console_irq == -1)
 753                         return -1;
 754         } else {
 755                 /* unlike in 2.4, we cannot autoprobe here, since
 756                  * the channel subsystem is not fully initialized.
 757                  * With some luck, the HWC console can take over */
 758                 printk(KERN_WARNING "cio: No ccw console found!\n");
 759                 return -1;
 760         }
 761         return console_irq;
 762 }
 763
 764 struct subchannel *
 765 cio_probe_console(void)
 766 {
 767         int sch_no, ret;
 768         struct subchannel_id schid;
 769
 770         if (xchg(&console_subchannel_in_use, 1) != 0)
 771                 return ERR_PTR(-EBUSY);
 772         sch_no = cio_get_console_sch_no();
 773         if (sch_no == -1) {
 774                 console_subchannel_in_use = 0;
 775                 return ERR_PTR(-ENODEV);
 776         }
 777         memset(&console_subchannel, 0, sizeof(struct subchannel));
 778         init_subchannel_id(&schid);
 779         schid.sch_no = sch_no;
 780         ret = cio_validate_subchannel(&console_subchannel, schid);
 781         if (ret) {
 782                 console_subchannel_in_use = 0;
 783                 return ERR_PTR(-ENODEV);
 784         }
 785
 786         /*
 787          * enable console I/O-interrupt subclass
 788          */
 789         ctl_set_bit(6, 31 - CONSOLE_ISC);
 790         console_subchannel.schib.pmcw.isc = CONSOLE_ISC;
 791         console_subchannel.schib.pmcw.intparm =
 792                 (u32)(addr_t)&console_subchannel;
 793         ret = cio_modify(&console_subchannel);
 794         if (ret) {
 795                 console_subchannel_in_use = 0;
 796                 return ERR_PTR(ret);
 797         }
 798         return &console_subchannel;
 799 }
 800
 801 void
 802 cio_release_console(void)
 803 {
 804         console_subchannel.schib.pmcw.intparm = 0;
 805         cio_modify(&console_subchannel);
 806         ctl_clear_bit(6, 31 - CONSOLE_ISC);
 807         console_subchannel_in_use = 0;
 808 }
 809
 810 /* Bah... hack to catch console special sausages. */
 811 int
 812 cio_is_console(struct subchannel_id schid)
 813 {
 814         if (!console_subchannel_in_use)
 815                 return 0;
 816         return schid_equal(&schid, &console_subchannel.schid);
 817 }
 818
 819 struct subchannel *
 820 cio_get_console_subchannel(void)
 821 {
 822         if (!console_subchannel_in_use)
 823                 return NULL;
 824         return &console_subchannel;
 825 }
 826
 827 #endif
 828 static int
 829 __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
 830 {
 831         int retry, cc;
 832
 833         cc = 0;
 834         for (retry=0;retry<3;retry++) {
 835                 schib->pmcw.ena = 0;
 836                 cc = msch(schid, schib);
 837                 if (cc)
 838                         return (cc==3?-ENODEV:-EBUSY);
 839                 stsch(schid, schib);
 840                 if (!schib->pmcw.ena)
 841                         return 0;
 842         }
 843         return -EBUSY; /* uhm... */
 844 }
 845
 846 /* we can't use the normal udelay here, since it enables external interrupts */
 847
 848 static void udelay_reset(unsigned long usecs)
 849 {
 850         uint64_t start_cc, end_cc;
 851
 852         asm volatile ("STCK %0" : "=m" (start_cc));
 853         do {
 854                 cpu_relax();
 855                 asm volatile ("STCK %0" : "=m" (end_cc));
 856         } while (((end_cc - start_cc)/4096) < usecs);
 857 }
 858
 859 static int
 860 __clear_io_subchannel_easy(struct subchannel_id schid)
 861 {
 862         int retry;
 863
 864         if (csch(schid))
 865                 return -ENODEV;
 866         for (retry=0;retry<20;retry++) {
 867                 struct tpi_info ti;
 868
 869                 if (tpi(&ti)) {
 870                         tsch(ti.schid, (struct irb *)__LC_IRB);
 871                         if (schid_equal(&ti.schid, &schid))
 872                                 return 0;
 873                 }
 874                 udelay_reset(100);
 875         }
 876         return -EBUSY;
 877 }
 878
 879 static int pgm_check_occured;
 880
 881 static void cio_reset_pgm_check_handler(void)
 882 {
 883         pgm_check_occured = 1;
 884 }
 885
 886 static int stsch_reset(struct subchannel_id schid, volatile struct schib *addr)
 887 {
 888         int rc;
 889
 890         pgm_check_occured = 0;
 891         s390_base_pgm_handler_fn = cio_reset_pgm_check_handler;
 892         rc = stsch(schid, addr);
 893         s390_base_pgm_handler_fn = NULL;
 894
 895         /* The program check handler could have changed pgm_check_occured. */
 896         barrier();
 897
 898         if (pgm_check_occured)
 899                 return -EIO;
 900         else
 901                 return rc;
 902 }
 903
 904 static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
 905 {
 906         struct schib schib;
 907
 908         if (stsch_reset(schid, &schib))
 909                 return -ENXIO;
 910         if (!schib.pmcw.ena)
 911                 return 0;
 912         switch(__disable_subchannel_easy(schid, &schib)) {
 913         case 0:
 914         case -ENODEV:
 915                 break;
 916         default: /* -EBUSY */
 917                 switch (schib.pmcw.st) {
 918                 case SUBCHANNEL_TYPE_IO:
 919                         if (__clear_io_subchannel_easy(schid))
 920                                 goto out; /* give up... */
 921                         break;
 922                 default:
 923                         /* No default clear strategy */
 924                         break;
 925                 }
 926                 stsch(schid, &schib);
 927                 __disable_subchannel_easy(schid, &schib);
 928         }
 929 out:
 930         return 0;
 931 }
 932
 933 static atomic_t chpid_reset_count;
 934
 935 static void s390_reset_chpids_mcck_handler(void)
 936 {
 937         struct crw crw;
 938         struct mci *mci;
 939
 940         /* Check for pending channel report word. */
 941         mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
 942         if (!mci->cp)
 943                 return;
 944         /* Process channel report words. */
 945         while (stcrw(&crw) == 0) {
 946                 /* Check for responses to RCHP. */
 947                 if (crw.slct && crw.rsc == CRW_RSC_CPATH)
 948                         atomic_dec(&chpid_reset_count);
 949         }
 950 }
 951
 952 #define RCHP_TIMEOUT (30 * USEC_PER_SEC)
 953 static void css_reset(void)
 954 {
 955         int i, ret;
 956         unsigned long long timeout;
 957         struct chp_id chpid;
 958
 959         /* Reset subchannels. */
 960         for_each_subchannel(__shutdown_subchannel_easy,  NULL);
 961         /* Reset channel paths. */
 962         s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler;
 963         /* Enable channel report machine checks. */
 964         __ctl_set_bit(14, 28);
 965         /* Temporarily reenable machine checks. */
 966         local_mcck_enable();
 967         chp_id_init(&chpid);
 968         for (i = 0; i <= __MAX_CHPID; i++) {
 969                 chpid.id = i;
 970                 ret = rchp(chpid);
 971                 if ((ret == 0) || (ret == 2))
 972                         /*
 973                          * rchp either succeeded, or another rchp is already
 974                          * in progress. In either case, we'll get a crw.
 975                          */
 976                         atomic_inc(&chpid_reset_count);
 977         }
 978         /* Wait for machine check for all channel paths. */
 979         timeout = get_clock() + (RCHP_TIMEOUT << 12);
 980         while (atomic_read(&chpid_reset_count) != 0) {
 981                 if (get_clock() > timeout)
 982                         break;
 983                 cpu_relax();
 984         }
 985         /* Disable machine checks again. */
 986         local_mcck_disable();
 987         /* Disable channel report machine checks. */
 988         __ctl_clear_bit(14, 28);
 989         s390_base_mcck_handler_fn = NULL;
 990 }
 991
 992 static struct reset_call css_reset_call = {
 993         .fn = css_reset,
 994 };
 995
 996 static int __init init_css_reset_call(void)
 997 {
 998         atomic_set(&chpid_reset_count, 0);
 999         register_reset_call(&css_reset_call);
1000         return 0;
1001 }
1002
1003 arch_initcall(init_css_reset_call);
1004
1005 struct sch_match_id {
1006         struct subchannel_id schid;
1007         struct ccw_dev_id devid;
1008         int rc;
1009 };
1010
1011 static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
1012 {
1013         struct schib schib;
1014         struct sch_match_id *match_id = data;
1015
1016         if (stsch_reset(schid, &schib))
1017                 return -ENXIO;
1018         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
1019             (schib.pmcw.dev == match_id->devid.devno) &&
1020             (schid.ssid == match_id->devid.ssid)) {
1021                 match_id->schid = schid;
1022                 match_id->rc = 0;
1023                 return 1;
1024         }
1025         return 0;
1026 }
1027
1028 static int reipl_find_schid(struct ccw_dev_id *devid,
1029                             struct subchannel_id *schid)
1030 {
1031         struct sch_match_id match_id;
1032
1033         match_id.devid = *devid;
1034         match_id.rc = -ENODEV;
1035         for_each_subchannel(__reipl_subchannel_match, &match_id);
1036         if (match_id.rc == 0)
1037                 *schid = match_id.schid;
1038         return match_id.rc;
1039 }
1040
1041 extern void do_reipl_asm(__u32 schid);
1042
1043 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
1044 void reipl_ccw_dev(struct ccw_dev_id *devid)
1045 {
1046         struct subchannel_id schid;
1047
1048         s390_reset_system();
1049         if (reipl_find_schid(devid, &schid) != 0)
1050                 panic("IPL Device not found\n");
1051         do_reipl_asm(*((__u32*)&schid));
1052 }
1053
1054 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
1055 {
1056         struct subchannel_id schid;
1057         struct schib schib;
1058
1059         schid = *(struct subchannel_id *)__LC_SUBCHANNEL_ID;
1060         if (!schid.one)
1061                 return -ENODEV;
1062         if (stsch(schid, &schib))
1063                 return -ENODEV;
1064         if (schib.pmcw.st != SUBCHANNEL_TYPE_IO)
1065                 return -ENODEV;
1066         if (!schib.pmcw.dnv)
1067                 return -ENODEV;
1068         iplinfo->devno = schib.pmcw.dev;
1069         iplinfo->is_qdio = schib.pmcw.qf;
1070         return 0;
1071 }
1072
1073 /**
1074  * cio_tm_start_key - perform start function
1075  * @sch: subchannel on which to perform the start function
1076  * @tcw: transport-command word to be started
1077  * @lpm: mask of paths to use
1078  * @key: storage key to use for storage access
1079  *
1080  * Start the tcw on the given subchannel. Return zero on success, non-zero
1081  * otherwise.
1082  */
1083 int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
1084 {
1085         int cc;
1086         union orb *orb = &to_io_private(sch)->orb;
1087
1088         memset(orb, 0, sizeof(union orb));
1089         orb->tm.intparm = (u32) (addr_t) sch;
1090         orb->tm.key = key >> 4;
1091         orb->tm.b = 1;
1092         orb->tm.lpm = lpm ? lpm : sch->lpm;
1093         orb->tm.tcw = (u32) (addr_t) tcw;
1094         cc = ssch(sch->schid, orb);
1095         switch (cc) {
1096         case 0:
1097                 return 0;
1098         case 1:
1099         case 2:
1100                 return -EBUSY;
1101         default:
1102                 return cio_start_handle_notoper(sch, lpm);
1103         }
1104 }
1105
1106 /**
1107  * cio_tm_intrg - perform interrogate function
1108  * @sch - subchannel on which to perform the interrogate function
1109  *
1110  * If the specified subchannel is running in transport-mode, perform the
1111  * interrogate function. Return zero on success, non-zero otherwie.
1112  */
1113 int cio_tm_intrg(struct subchannel *sch)
1114 {
1115         int cc;
1116
1117         if (!to_io_private(sch)->orb.tm.b)
1118                 return -EINVAL;
1119         cc = xsch(sch->schid);
1120         switch (cc) {
1121         case 0:
1122         case 2:
1123                 return 0;
1124         case 1:
1125                 return -EBUSY;
1126         default:
1127                 return -ENODEV;
1128         }
1129 }