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