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 (C) IBM Corp. 1999,2006
   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 "airq.h"
  27 #include "cio.h"
  28 #include "css.h"
  29 #include "chsc.h"
  30 #include "ioasm.h"
  31 #include "blacklist.h"
  32 #include "cio_debug.h"
  33 #include "chp.h"
  34 #include "../s390mach.h"
  35
  36 debug_info_t *cio_debug_msg_id;
  37 debug_info_t *cio_debug_trace_id;
  38 debug_info_t *cio_debug_crw_id;
  39
  40 int cio_show_msg;
  41
  42 static int __init
  43 cio_setup (char *parm)
  44 {
  45         if (!strcmp (parm, "yes"))
  46                 cio_show_msg = 1;
  47         else if (!strcmp (parm, "no"))
  48                 cio_show_msg = 0;
  49         else
  50                 printk (KERN_ERR "cio_setup : invalid cio_msg parameter '%s'",
  51                         parm);
  52         return 1;
  53 }
  54
  55 __setup ("cio_msg=", cio_setup);
  56
  57 /*
  58  * Function: cio_debug_init
  59  * Initializes three debug logs (under /proc/s390dbf) for common I/O:
  60  * - cio_msg logs the messages which are printk'ed when CONFIG_DEBUG_IO is on
  61  * - cio_trace logs the calling of different functions
  62  * - cio_crw logs the messages which are printk'ed when CONFIG_DEBUG_CRW is on
  63  * debug levels depend on CONFIG_DEBUG_IO resp. CONFIG_DEBUG_CRW
  64  */
  65 static int __init
  66 cio_debug_init (void)
  67 {
  68         cio_debug_msg_id = debug_register ("cio_msg", 16, 4, 16*sizeof (long));
  69         if (!cio_debug_msg_id)
  70                 goto out_unregister;
  71         debug_register_view (cio_debug_msg_id, &debug_sprintf_view);
  72         debug_set_level (cio_debug_msg_id, 2);
  73         cio_debug_trace_id = debug_register ("cio_trace", 16, 4, 16);
  74         if (!cio_debug_trace_id)
  75                 goto out_unregister;
  76         debug_register_view (cio_debug_trace_id, &debug_hex_ascii_view);
  77         debug_set_level (cio_debug_trace_id, 2);
  78         cio_debug_crw_id = debug_register ("cio_crw", 4, 4, 16*sizeof (long));
  79         if (!cio_debug_crw_id)
  80                 goto out_unregister;
  81         debug_register_view (cio_debug_crw_id, &debug_sprintf_view);
  82         debug_set_level (cio_debug_crw_id, 2);
  83         pr_debug("debugging initialized\n");
  84         return 0;
  85
  86 out_unregister:
  87         if (cio_debug_msg_id)
  88                 debug_unregister (cio_debug_msg_id);
  89         if (cio_debug_trace_id)
  90                 debug_unregister (cio_debug_trace_id);
  91         if (cio_debug_crw_id)
  92                 debug_unregister (cio_debug_crw_id);
  93         pr_debug("could not initialize debugging\n");
  94         return -1;
  95 }
  96
  97 arch_initcall (cio_debug_init);
  98
  99 int
 100 cio_set_options (struct subchannel *sch, int flags)
 101 {
 102        sch->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
 103        sch->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
 104        sch->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
 105        return 0;
 106 }
 107
 108 /* FIXME: who wants to use this? */
 109 int
 110 cio_get_options (struct subchannel *sch)
 111 {
 112        int flags;
 113
 114        flags = 0;
 115        if (sch->options.suspend)
 116                 flags |= DOIO_ALLOW_SUSPEND;
 117        if (sch->options.prefetch)
 118                 flags |= DOIO_DENY_PREFETCH;
 119        if (sch->options.inter)
 120                 flags |= DOIO_SUPPRESS_INTER;
 121        return flags;
 122 }
 123
 124 /*
 125  * Use tpi to get a pending interrupt, call the interrupt handler and
 126  * return a pointer to the subchannel structure.
 127  */
 128 static int
 129 cio_tpi(void)
 130 {
 131         struct tpi_info *tpi_info;
 132         struct subchannel *sch;
 133         struct irb *irb;
 134
 135         tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
 136         if (tpi (NULL) != 1)
 137                 return 0;
 138         irb = (struct irb *) __LC_IRB;
 139         /* Store interrupt response block to lowcore. */
 140         if (tsch (tpi_info->schid, irb) != 0)
 141                 /* Not status pending or not operational. */
 142                 return 1;
 143         sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 144         if (!sch)
 145                 return 1;
 146         local_bh_disable();
 147         irq_enter ();
 148         spin_lock(sch->lock);
 149         memcpy (&sch->schib.scsw, &irb->scsw, sizeof (struct scsw));
 150         if (sch->driver && sch->driver->irq)
 151                 sch->driver->irq(&sch->dev);
 152         spin_unlock(sch->lock);
 153         irq_exit ();
 154         _local_bh_enable();
 155         return 1;
 156 }
 157
 158 static int
 159 cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
 160 {
 161         char dbf_text[15];
 162
 163         if (lpm != 0)
 164                 sch->lpm &= ~lpm;
 165         else
 166                 sch->lpm = 0;
 167
 168         stsch (sch->schid, &sch->schib);
 169
 170         CIO_MSG_EVENT(0, "cio_start: 'not oper' status for "
 171                       "subchannel 0.%x.%04x!\n", sch->schid.ssid,
 172                       sch->schid.sch_no);
 173         sprintf(dbf_text, "no%s", sch->dev.bus_id);
 174         CIO_TRACE_EVENT(0, dbf_text);
 175         CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
 176
 177         return (sch->lpm ? -EACCES : -ENODEV);
 178 }
 179
 180 int
 181 cio_start_key (struct subchannel *sch,  /* subchannel structure */
 182                struct ccw1 * cpa,       /* logical channel prog addr */
 183                __u8 lpm,                /* logical path mask */
 184                __u8 key)                /* storage key */
 185 {
 186         char dbf_txt[15];
 187         int ccode;
 188
 189         CIO_TRACE_EVENT (4, "stIO");
 190         CIO_TRACE_EVENT (4, sch->dev.bus_id);
 191
 192         /* sch is always under 2G. */
 193         sch->orb.intparm = (__u32)(unsigned long)sch;
 194         sch->orb.fmt = 1;
 195
 196         sch->orb.pfch = sch->options.prefetch == 0;
 197         sch->orb.spnd = sch->options.suspend;
 198         sch->orb.ssic = sch->options.suspend && sch->options.inter;
 199         sch->orb.lpm = (lpm != 0) ? lpm : sch->lpm;
 200 #ifdef CONFIG_64BIT
 201         /*
 202          * for 64 bit we always support 64 bit IDAWs with 4k page size only
 203          */
 204         sch->orb.c64 = 1;
 205         sch->orb.i2k = 0;
 206 #endif
 207         sch->orb.key = key >> 4;
 208         /* issue "Start Subchannel" */
 209         sch->orb.cpa = (__u32) __pa (cpa);
 210         ccode = ssch (sch->schid, &sch->orb);
 211
 212         /* process condition code */
 213         sprintf (dbf_txt, "ccode:%d", ccode);
 214         CIO_TRACE_EVENT (4, dbf_txt);
 215
 216         switch (ccode) {
 217         case 0:
 218                 /*
 219                  * initialize device status information
 220                  */
 221                 sch->schib.scsw.actl |= SCSW_ACTL_START_PEND;
 222                 return 0;
 223         case 1:         /* status pending */
 224         case 2:         /* busy */
 225                 return -EBUSY;
 226         default:                /* device/path not operational */
 227                 return cio_start_handle_notoper(sch, lpm);
 228         }
 229 }
 230
 231 int
 232 cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
 233 {
 234         return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
 235 }
 236
 237 /*
 238  * resume suspended I/O operation
 239  */
 240 int
 241 cio_resume (struct subchannel *sch)
 242 {
 243         char dbf_txt[15];
 244         int ccode;
 245
 246         CIO_TRACE_EVENT (4, "resIO");
 247         CIO_TRACE_EVENT (4, sch->dev.bus_id);
 248
 249         ccode = rsch (sch->schid);
 250
 251         sprintf (dbf_txt, "ccode:%d", ccode);
 252         CIO_TRACE_EVENT (4, dbf_txt);
 253
 254         switch (ccode) {
 255         case 0:
 256                 sch->schib.scsw.actl |= SCSW_ACTL_RESUME_PEND;
 257                 return 0;
 258         case 1:
 259                 return -EBUSY;
 260         case 2:
 261                 return -EINVAL;
 262         default:
 263                 /*
 264                  * useless to wait for request completion
 265                  *  as device is no longer operational !
 266                  */
 267                 return -ENODEV;
 268         }
 269 }
 270
 271 /*
 272  * halt I/O operation
 273  */
 274 int
 275 cio_halt(struct subchannel *sch)
 276 {
 277         char dbf_txt[15];
 278         int ccode;
 279
 280         if (!sch)
 281                 return -ENODEV;
 282
 283         CIO_TRACE_EVENT (2, "haltIO");
 284         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 285
 286         /*
 287          * Issue "Halt subchannel" and process condition code
 288          */
 289         ccode = hsch (sch->schid);
 290
 291         sprintf (dbf_txt, "ccode:%d", ccode);
 292         CIO_TRACE_EVENT (2, dbf_txt);
 293
 294         switch (ccode) {
 295         case 0:
 296                 sch->schib.scsw.actl |= SCSW_ACTL_HALT_PEND;
 297                 return 0;
 298         case 1:         /* status pending */
 299         case 2:         /* busy */
 300                 return -EBUSY;
 301         default:                /* device not operational */
 302                 return -ENODEV;
 303         }
 304 }
 305
 306 /*
 307  * Clear I/O operation
 308  */
 309 int
 310 cio_clear(struct subchannel *sch)
 311 {
 312         char dbf_txt[15];
 313         int ccode;
 314
 315         if (!sch)
 316                 return -ENODEV;
 317
 318         CIO_TRACE_EVENT (2, "clearIO");
 319         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 320
 321         /*
 322          * Issue "Clear subchannel" and process condition code
 323          */
 324         ccode = csch (sch->schid);
 325
 326         sprintf (dbf_txt, "ccode:%d", ccode);
 327         CIO_TRACE_EVENT (2, dbf_txt);
 328
 329         switch (ccode) {
 330         case 0:
 331                 sch->schib.scsw.actl |= SCSW_ACTL_CLEAR_PEND;
 332                 return 0;
 333         default:                /* device not operational */
 334                 return -ENODEV;
 335         }
 336 }
 337
 338 /*
 339  * Function: cio_cancel
 340  * Issues a "Cancel Subchannel" on the specified subchannel
 341  * Note: We don't need any fancy intparms and flags here
 342  *       since xsch is executed synchronously.
 343  * Only for common I/O internal use as for now.
 344  */
 345 int
 346 cio_cancel (struct subchannel *sch)
 347 {
 348         char dbf_txt[15];
 349         int ccode;
 350
 351         if (!sch)
 352                 return -ENODEV;
 353
 354         CIO_TRACE_EVENT (2, "cancelIO");
 355         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 356
 357         ccode = xsch (sch->schid);
 358
 359         sprintf (dbf_txt, "ccode:%d", ccode);
 360         CIO_TRACE_EVENT (2, dbf_txt);
 361
 362         switch (ccode) {
 363         case 0:         /* success */
 364                 /* Update information in scsw. */
 365                 stsch (sch->schid, &sch->schib);
 366                 return 0;
 367         case 1:         /* status pending */
 368                 return -EBUSY;
 369         case 2:         /* not applicable */
 370                 return -EINVAL;
 371         default:        /* not oper */
 372                 return -ENODEV;
 373         }
 374 }
 375
 376 /*
 377  * Function: cio_modify
 378  * Issues a "Modify Subchannel" on the specified subchannel
 379  */
 380 int
 381 cio_modify (struct subchannel *sch)
 382 {
 383         int ccode, retry, ret;
 384
 385         ret = 0;
 386         for (retry = 0; retry < 5; retry++) {
 387                 ccode = msch_err (sch->schid, &sch->schib);
 388                 if (ccode < 0)  /* -EIO if msch gets a program check. */
 389                         return ccode;
 390                 switch (ccode) {
 391                 case 0: /* successfull */
 392                         return 0;
 393                 case 1: /* status pending */
 394                         return -EBUSY;
 395                 case 2: /* busy */
 396                         udelay (100);   /* allow for recovery */
 397                         ret = -EBUSY;
 398                         break;
 399                 case 3: /* not operational */
 400                         return -ENODEV;
 401                 }
 402         }
 403         return ret;
 404 }
 405
 406 /*
 407  * Enable subchannel.
 408  */
 409 int
 410 cio_enable_subchannel (struct subchannel *sch, unsigned int isc)
 411 {
 412         char dbf_txt[15];
 413         int ccode;
 414         int retry;
 415         int ret;
 416
 417         CIO_TRACE_EVENT (2, "ensch");
 418         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 419
 420         if (sch_is_pseudo_sch(sch))
 421                 return -EINVAL;
 422         ccode = stsch (sch->schid, &sch->schib);
 423         if (ccode)
 424                 return -ENODEV;
 425
 426         for (retry = 5, ret = 0; retry > 0; retry--) {
 427                 sch->schib.pmcw.ena = 1;
 428                 sch->schib.pmcw.isc = isc;
 429                 sch->schib.pmcw.intparm = (__u32)(unsigned long)sch;
 430                 ret = cio_modify(sch);
 431                 if (ret == -ENODEV)
 432                         break;
 433                 if (ret == -EIO)
 434                         /*
 435                          * Got a program check in cio_modify. Try without
 436                          * the concurrent sense bit the next time.
 437                          */
 438                         sch->schib.pmcw.csense = 0;
 439                 if (ret == 0) {
 440                         stsch (sch->schid, &sch->schib);
 441                         if (sch->schib.pmcw.ena)
 442                                 break;
 443                 }
 444                 if (ret == -EBUSY) {
 445                         struct irb irb;
 446                         if (tsch(sch->schid, &irb) != 0)
 447                                 break;
 448                 }
 449         }
 450         sprintf (dbf_txt, "ret:%d", ret);
 451         CIO_TRACE_EVENT (2, dbf_txt);
 452         return ret;
 453 }
 454
 455 /*
 456  * Disable subchannel.
 457  */
 458 int
 459 cio_disable_subchannel (struct subchannel *sch)
 460 {
 461         char dbf_txt[15];
 462         int ccode;
 463         int retry;
 464         int ret;
 465
 466         CIO_TRACE_EVENT (2, "dissch");
 467         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 468
 469         if (sch_is_pseudo_sch(sch))
 470                 return 0;
 471         ccode = stsch (sch->schid, &sch->schib);
 472         if (ccode == 3)         /* Not operational. */
 473                 return -ENODEV;
 474
 475         if (sch->schib.scsw.actl != 0)
 476                 /*
 477                  * the disable function must not be called while there are
 478                  *  requests pending for completion !
 479                  */
 480                 return -EBUSY;
 481
 482         for (retry = 5, ret = 0; retry > 0; retry--) {
 483                 sch->schib.pmcw.ena = 0;
 484                 ret = cio_modify(sch);
 485                 if (ret == -ENODEV)
 486                         break;
 487                 if (ret == -EBUSY)
 488                         /*
 489                          * The subchannel is busy or status pending.
 490                          * We'll disable when the next interrupt was delivered
 491                          * via the state machine.
 492                          */
 493                         break;
 494                 if (ret == 0) {
 495                         stsch (sch->schid, &sch->schib);
 496                         if (!sch->schib.pmcw.ena)
 497                                 break;
 498                 }
 499         }
 500         sprintf (dbf_txt, "ret:%d", ret);
 501         CIO_TRACE_EVENT (2, dbf_txt);
 502         return ret;
 503 }
 504
 505 int cio_create_sch_lock(struct subchannel *sch)
 506 {
 507         sch->lock = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
 508         if (!sch->lock)
 509                 return -ENOMEM;
 510         spin_lock_init(sch->lock);
 511         return 0;
 512 }
 513
 514 /*
 515  * cio_validate_subchannel()
 516  *
 517  * Find out subchannel type and initialize struct subchannel.
 518  * Return codes:
 519  *   SUBCHANNEL_TYPE_IO for a normal io subchannel
 520  *   SUBCHANNEL_TYPE_CHSC for a chsc subchannel
 521  *   SUBCHANNEL_TYPE_MESSAGE for a messaging subchannel
 522  *   SUBCHANNEL_TYPE_ADM for a adm(?) subchannel
 523  *   -ENXIO for non-defined subchannels
 524  *   -ENODEV for subchannels with invalid device number or blacklisted devices
 525  */
 526 int
 527 cio_validate_subchannel (struct subchannel *sch, struct subchannel_id schid)
 528 {
 529         char dbf_txt[15];
 530         int ccode;
 531         int err;
 532
 533         sprintf (dbf_txt, "valsch%x", schid.sch_no);
 534         CIO_TRACE_EVENT (4, dbf_txt);
 535
 536         /* Nuke all fields. */
 537         memset(sch, 0, sizeof(struct subchannel));
 538
 539         sch->schid = schid;
 540         if (cio_is_console(schid)) {
 541                 sch->lock = cio_get_console_lock();
 542         } else {
 543                 err = cio_create_sch_lock(sch);
 544                 if (err)
 545                         goto out;
 546         }
 547         mutex_init(&sch->reg_mutex);
 548         /* Set a name for the subchannel */
 549         snprintf (sch->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x", schid.ssid,
 550                   schid.sch_no);
 551
 552         /*
 553          * The first subchannel that is not-operational (ccode==3)
 554          *  indicates that there aren't any more devices available.
 555          * If stsch gets an exception, it means the current subchannel set
 556          *  is not valid.
 557          */
 558         ccode = stsch_err (schid, &sch->schib);
 559         if (ccode) {
 560                 err = (ccode == 3) ? -ENXIO : ccode;
 561                 goto out;
 562         }
 563         /* Copy subchannel type from path management control word. */
 564         sch->st = sch->schib.pmcw.st;
 565
 566         /*
 567          * ... just being curious we check for non I/O subchannels
 568          */
 569         if (sch->st != 0) {
 570                 CIO_DEBUG(KERN_INFO, 0,
 571                           "Subchannel 0.%x.%04x reports "
 572                           "non-I/O subchannel type %04X\n",
 573                           sch->schid.ssid, sch->schid.sch_no, sch->st);
 574                 /* We stop here for non-io subchannels. */
 575                 err = sch->st;
 576                 goto out;
 577         }
 578
 579         /* Initialization for io subchannels. */
 580         if (!sch->schib.pmcw.dnv) {
 581                 /* io subchannel but device number is invalid. */
 582                 err = -ENODEV;
 583                 goto out;
 584         }
 585         /* Devno is valid. */
 586         if (is_blacklisted (sch->schid.ssid, sch->schib.pmcw.dev)) {
 587                 /*
 588                  * This device must not be known to Linux. So we simply
 589                  * say that there is no device and return ENODEV.
 590                  */
 591                 CIO_MSG_EVENT(4, "Blacklisted device detected "
 592                               "at devno %04X, subchannel set %x\n",
 593                               sch->schib.pmcw.dev, sch->schid.ssid);
 594                 err = -ENODEV;
 595                 goto out;
 596         }
 597         if (cio_is_console(sch->schid))
 598                 sch->opm = 0xff;
 599         else
 600                 sch->opm = chp_get_sch_opm(sch);
 601         sch->lpm = sch->schib.pmcw.pam & sch->opm;
 602
 603         CIO_DEBUG(KERN_INFO, 0,
 604                   "Detected device %04x on subchannel 0.%x.%04X"
 605                   " - PIM = %02X, PAM = %02X, POM = %02X\n",
 606                   sch->schib.pmcw.dev, sch->schid.ssid,
 607                   sch->schid.sch_no, sch->schib.pmcw.pim,
 608                   sch->schib.pmcw.pam, sch->schib.pmcw.pom);
 609
 610         /*
 611          * We now have to initially ...
 612          *  ... set "interruption subclass"
 613          *  ... enable "concurrent sense"
 614          *  ... enable "multipath mode" if more than one
 615          *        CHPID is available. This is done regardless
 616          *        whether multiple paths are available for us.
 617          */
 618         sch->schib.pmcw.isc = 3;        /* could be smth. else */
 619         sch->schib.pmcw.csense = 1;     /* concurrent sense */
 620         sch->schib.pmcw.ena = 0;
 621         if ((sch->lpm & (sch->lpm - 1)) != 0)
 622                 sch->schib.pmcw.mp = 1; /* multipath mode */
 623         return 0;
 624 out:
 625         if (!cio_is_console(schid))
 626                 kfree(sch->lock);
 627         sch->lock = NULL;
 628         return err;
 629 }
 630
 631 /*
 632  * do_IRQ() handles all normal I/O device IRQ's (the special
 633  *          SMP cross-CPU interrupts have their own specific
 634  *          handlers).
 635  *
 636  */
 637 void
 638 do_IRQ (struct pt_regs *regs)
 639 {
 640         struct tpi_info *tpi_info;
 641         struct subchannel *sch;
 642         struct irb *irb;
 643         struct pt_regs *old_regs;
 644
 645         old_regs = set_irq_regs(regs);
 646         irq_enter();
 647         asm volatile ("mc 0,0");
 648         if (S390_lowcore.int_clock >= S390_lowcore.jiffy_timer)
 649                 /**
 650                  * Make sure that the i/o interrupt did not "overtake"
 651                  * the last HZ timer interrupt.
 652                  */
 653                 account_ticks(S390_lowcore.int_clock);
 654         /*
 655          * Get interrupt information from lowcore
 656          */
 657         tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
 658         irb = (struct irb *) __LC_IRB;
 659         do {
 660                 kstat_cpu(smp_processor_id()).irqs[IO_INTERRUPT]++;
 661                 /*
 662                  * Non I/O-subchannel thin interrupts are processed differently
 663                  */
 664                 if (tpi_info->adapter_IO == 1 &&
 665                     tpi_info->int_type == IO_INTERRUPT_TYPE) {
 666                         do_adapter_IO();
 667                         continue;
 668                 }
 669                 sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 670                 if (sch)
 671                         spin_lock(sch->lock);
 672                 /* Store interrupt response block to lowcore. */
 673                 if (tsch (tpi_info->schid, irb) == 0 && sch) {
 674                         /* Keep subchannel information word up to date. */
 675                         memcpy (&sch->schib.scsw, &irb->scsw,
 676                                 sizeof (irb->scsw));
 677                         /* Call interrupt handler if there is one. */
 678                         if (sch->driver && sch->driver->irq)
 679                                 sch->driver->irq(&sch->dev);
 680                 }
 681                 if (sch)
 682                         spin_unlock(sch->lock);
 683                 /*
 684                  * Are more interrupts pending?
 685                  * If so, the tpi instruction will update the lowcore
 686                  * to hold the info for the next interrupt.
 687                  * We don't do this for VM because a tpi drops the cpu
 688                  * out of the sie which costs more cycles than it saves.
 689                  */
 690         } while (!MACHINE_IS_VM && tpi (NULL) != 0);
 691         irq_exit();
 692         set_irq_regs(old_regs);
 693 }
 694
 695 #ifdef CONFIG_CCW_CONSOLE
 696 static struct subchannel console_subchannel;
 697 static int console_subchannel_in_use;
 698
 699 /*
 700  * busy wait for the next interrupt on the console
 701  */
 702 void
 703 wait_cons_dev (void)
 704 {
 705         unsigned long cr6      __attribute__ ((aligned (8)));
 706         unsigned long save_cr6 __attribute__ ((aligned (8)));
 707
 708         /*
 709          * before entering the spinlock we may already have
 710          * processed the interrupt on a different CPU...
 711          */
 712         if (!console_subchannel_in_use)
 713                 return;
 714
 715         /* disable all but isc 7 (console device) */
 716         __ctl_store (save_cr6, 6, 6);
 717         cr6 = 0x01000000;
 718         __ctl_load (cr6, 6, 6);
 719
 720         do {
 721                 spin_unlock(console_subchannel.lock);
 722                 if (!cio_tpi())
 723                         cpu_relax();
 724                 spin_lock(console_subchannel.lock);
 725         } while (console_subchannel.schib.scsw.actl != 0);
 726         /*
 727          * restore previous isc value
 728          */
 729         __ctl_load (save_cr6, 6, 6);
 730 }
 731
 732 static int
 733 cio_test_for_console(struct subchannel_id schid, void *data)
 734 {
 735         if (stsch_err(schid, &console_subchannel.schib) != 0)
 736                 return -ENXIO;
 737         if (console_subchannel.schib.pmcw.dnv &&
 738             console_subchannel.schib.pmcw.dev ==
 739             console_devno) {
 740                 console_irq = schid.sch_no;
 741                 return 1; /* found */
 742         }
 743         return 0;
 744 }
 745
 746
 747 static int
 748 cio_get_console_sch_no(void)
 749 {
 750         struct subchannel_id schid;
 751
 752         init_subchannel_id(&schid);
 753         if (console_irq != -1) {
 754                 /* VM provided us with the irq number of the console. */
 755                 schid.sch_no = console_irq;
 756                 if (stsch(schid, &console_subchannel.schib) != 0 ||
 757                     !console_subchannel.schib.pmcw.dnv)
 758                         return -1;
 759                 console_devno = console_subchannel.schib.pmcw.dev;
 760         } else if (console_devno != -1) {
 761                 /* At least the console device number is known. */
 762                 for_each_subchannel(cio_test_for_console, NULL);
 763                 if (console_irq == -1)
 764                         return -1;
 765         } else {
 766                 /* unlike in 2.4, we cannot autoprobe here, since
 767                  * the channel subsystem is not fully initialized.
 768                  * With some luck, the HWC console can take over */
 769                 printk(KERN_WARNING "No ccw console found!\n");
 770                 return -1;
 771         }
 772         return console_irq;
 773 }
 774
 775 struct subchannel *
 776 cio_probe_console(void)
 777 {
 778         int sch_no, ret;
 779         struct subchannel_id schid;
 780
 781         if (xchg(&console_subchannel_in_use, 1) != 0)
 782                 return ERR_PTR(-EBUSY);
 783         sch_no = cio_get_console_sch_no();
 784         if (sch_no == -1) {
 785                 console_subchannel_in_use = 0;
 786                 return ERR_PTR(-ENODEV);
 787         }
 788         memset(&console_subchannel, 0, sizeof(struct subchannel));
 789         init_subchannel_id(&schid);
 790         schid.sch_no = sch_no;
 791         ret = cio_validate_subchannel(&console_subchannel, schid);
 792         if (ret) {
 793                 console_subchannel_in_use = 0;
 794                 return ERR_PTR(-ENODEV);
 795         }
 796
 797         /*
 798          * enable console I/O-interrupt subclass 7
 799          */
 800         ctl_set_bit(6, 24);
 801         console_subchannel.schib.pmcw.isc = 7;
 802         console_subchannel.schib.pmcw.intparm =
 803                 (__u32)(unsigned long)&console_subchannel;
 804         ret = cio_modify(&console_subchannel);
 805         if (ret) {
 806                 console_subchannel_in_use = 0;
 807                 return ERR_PTR(ret);
 808         }
 809         return &console_subchannel;
 810 }
 811
 812 void
 813 cio_release_console(void)
 814 {
 815         console_subchannel.schib.pmcw.intparm = 0;
 816         cio_modify(&console_subchannel);
 817         ctl_clear_bit(6, 24);
 818         console_subchannel_in_use = 0;
 819 }
 820
 821 /* Bah... hack to catch console special sausages. */
 822 int
 823 cio_is_console(struct subchannel_id schid)
 824 {
 825         if (!console_subchannel_in_use)
 826                 return 0;
 827         return schid_equal(&schid, &console_subchannel.schid);
 828 }
 829
 830 struct subchannel *
 831 cio_get_console_subchannel(void)
 832 {
 833         if (!console_subchannel_in_use)
 834                 return NULL;
 835         return &console_subchannel;
 836 }
 837
 838 #endif
 839 static int
 840 __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
 841 {
 842         int retry, cc;
 843
 844         cc = 0;
 845         for (retry=0;retry<3;retry++) {
 846                 schib->pmcw.ena = 0;
 847                 cc = msch(schid, schib);
 848                 if (cc)
 849                         return (cc==3?-ENODEV:-EBUSY);
 850                 stsch(schid, schib);
 851                 if (!schib->pmcw.ena)
 852                         return 0;
 853         }
 854         return -EBUSY; /* uhm... */
 855 }
 856
 857 /* we can't use the normal udelay here, since it enables external interrupts */
 858
 859 static void udelay_reset(unsigned long usecs)
 860 {
 861         uint64_t start_cc, end_cc;
 862
 863         asm volatile ("STCK %0" : "=m" (start_cc));
 864         do {
 865                 cpu_relax();
 866                 asm volatile ("STCK %0" : "=m" (end_cc));
 867         } while (((end_cc - start_cc)/4096) < usecs);
 868 }
 869
 870 static int
 871 __clear_subchannel_easy(struct subchannel_id schid)
 872 {
 873         int retry;
 874
 875         if (csch(schid))
 876                 return -ENODEV;
 877         for (retry=0;retry<20;retry++) {
 878                 struct tpi_info ti;
 879
 880                 if (tpi(&ti)) {
 881                         tsch(ti.schid, (struct irb *)__LC_IRB);
 882                         if (schid_equal(&ti.schid, &schid))
 883                                 return 0;
 884                 }
 885                 udelay_reset(100);
 886         }
 887         return -EBUSY;
 888 }
 889
 890 static int pgm_check_occured;
 891
 892 static void cio_reset_pgm_check_handler(void)
 893 {
 894         pgm_check_occured = 1;
 895 }
 896
 897 static int stsch_reset(struct subchannel_id schid, volatile struct schib *addr)
 898 {
 899         int rc;
 900
 901         pgm_check_occured = 0;
 902         s390_base_pgm_handler_fn = cio_reset_pgm_check_handler;
 903         rc = stsch(schid, addr);
 904         s390_base_pgm_handler_fn = NULL;
 905
 906         /* The program check handler could have changed pgm_check_occured. */
 907         barrier();
 908
 909         if (pgm_check_occured)
 910                 return -EIO;
 911         else
 912                 return rc;
 913 }
 914
 915 static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
 916 {
 917         struct schib schib;
 918
 919         if (stsch_reset(schid, &schib))
 920                 return -ENXIO;
 921         if (!schib.pmcw.ena)
 922                 return 0;
 923         switch(__disable_subchannel_easy(schid, &schib)) {
 924         case 0:
 925         case -ENODEV:
 926                 break;
 927         default: /* -EBUSY */
 928                 if (__clear_subchannel_easy(schid))
 929                         break; /* give up... */
 930                 stsch(schid, &schib);
 931                 __disable_subchannel_easy(schid, &schib);
 932         }
 933         return 0;
 934 }
 935
 936 static atomic_t chpid_reset_count;
 937
 938 static void s390_reset_chpids_mcck_handler(void)
 939 {
 940         struct crw crw;
 941         struct mci *mci;
 942
 943         /* Check for pending channel report word. */
 944         mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
 945         if (!mci->cp)
 946                 return;
 947         /* Process channel report words. */
 948         while (stcrw(&crw) == 0) {
 949                 /* Check for responses to RCHP. */
 950                 if (crw.slct && crw.rsc == CRW_RSC_CPATH)
 951                         atomic_dec(&chpid_reset_count);
 952         }
 953 }
 954
 955 #define RCHP_TIMEOUT (30 * USEC_PER_SEC)
 956 static void css_reset(void)
 957 {
 958         int i, ret;
 959         unsigned long long timeout;
 960         struct chp_id chpid;
 961
 962         /* Reset subchannels. */
 963         for_each_subchannel(__shutdown_subchannel_easy,  NULL);
 964         /* Reset channel paths. */
 965         s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler;
 966         /* Enable channel report machine checks. */
 967         __ctl_set_bit(14, 28);
 968         /* Temporarily reenable machine checks. */
 969         local_mcck_enable();
 970         chp_id_init(&chpid);
 971         for (i = 0; i <= __MAX_CHPID; i++) {
 972                 chpid.id = i;
 973                 ret = rchp(chpid);
 974                 if ((ret == 0) || (ret == 2))
 975                         /*
 976                          * rchp either succeeded, or another rchp is already
 977                          * in progress. In either case, we'll get a crw.
 978                          */
 979                         atomic_inc(&chpid_reset_count);
 980         }
 981         /* Wait for machine check for all channel paths. */
 982         timeout = get_clock() + (RCHP_TIMEOUT << 12);
 983         while (atomic_read(&chpid_reset_count) != 0) {
 984                 if (get_clock() > timeout)
 985                         break;
 986                 cpu_relax();
 987         }
 988         /* Disable machine checks again. */
 989         local_mcck_disable();
 990         /* Disable channel report machine checks. */
 991         __ctl_clear_bit(14, 28);
 992         s390_base_mcck_handler_fn = NULL;
 993 }
 994
 995 static struct reset_call css_reset_call = {
 996         .fn = css_reset,
 997 };
 998
 999 static int __init init_css_reset_call(void)
1000 {
1001         atomic_set(&chpid_reset_count, 0);
1002         register_reset_call(&css_reset_call);
1003         return 0;
1004 }
1005
1006 arch_initcall(init_css_reset_call);
1007
1008 struct sch_match_id {
1009         struct subchannel_id schid;
1010         struct ccw_dev_id devid;
1011         int rc;
1012 };
1013
1014 static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
1015 {
1016         struct schib schib;
1017         struct sch_match_id *match_id = data;
1018
1019         if (stsch_reset(schid, &schib))
1020                 return -ENXIO;
1021         if (schib.pmcw.dnv &&
1022             (schib.pmcw.dev == match_id->devid.devno) &&
1023             (schid.ssid == match_id->devid.ssid)) {
1024                 match_id->schid = schid;
1025                 match_id->rc = 0;
1026                 return 1;
1027         }
1028         return 0;
1029 }
1030
1031 static int reipl_find_schid(struct ccw_dev_id *devid,
1032                             struct subchannel_id *schid)
1033 {
1034         struct sch_match_id match_id;
1035
1036         match_id.devid = *devid;
1037         match_id.rc = -ENODEV;
1038         for_each_subchannel(__reipl_subchannel_match, &match_id);
1039         if (match_id.rc == 0)
1040                 *schid = match_id.schid;
1041         return match_id.rc;
1042 }
1043
1044 extern void do_reipl_asm(__u32 schid);
1045
1046 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
1047 void reipl_ccw_dev(struct ccw_dev_id *devid)
1048 {
1049         struct subchannel_id schid;
1050
1051         s390_reset_system();
1052         if (reipl_find_schid(devid, &schid) != 0)
1053                 panic("IPL Device not found\n");
1054         do_reipl_asm(*((__u32*)&schid));
1055 }
1056
1057 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
1058 {
1059         struct subchannel_id schid;
1060         struct schib schib;
1061
1062         schid = *(struct subchannel_id *)__LC_SUBCHANNEL_ID;
1063         if (!schid.one)
1064                 return -ENODEV;
1065         if (stsch(schid, &schib))
1066                 return -ENODEV;
1067         if (!schib.pmcw.dnv)
1068                 return -ENODEV;
1069         iplinfo->devno = schib.pmcw.dev;
1070         iplinfo->is_qdio = schib.pmcw.qf;
1071         return 0;
1072 }