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