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) 1999-2002 IBM Deutschland Entwicklung GmbH,
   6  *                            IBM Corporation
   7  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
   8  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   9  *               Arnd Bergmann (arndb@de.ibm.com)
  10  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/config.h>
  15 #include <linux/init.h>
  16 #include <linux/slab.h>
  17 #include <linux/device.h>
  18 #include <linux/kernel_stat.h>
  19 #include <linux/interrupt.h>
  20
  21 #include <asm/cio.h>
  22 #include <asm/delay.h>
  23 #include <asm/irq.h>
  24
  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
  33 debug_info_t *cio_debug_msg_id;
  34 debug_info_t *cio_debug_trace_id;
  35 debug_info_t *cio_debug_crw_id;
  36
  37 int cio_show_msg;
  38
  39 static int __init
  40 cio_setup (char *parm)
  41 {
  42         if (!strcmp (parm, "yes"))
  43                 cio_show_msg = 1;
  44         else if (!strcmp (parm, "no"))
  45                 cio_show_msg = 0;
  46         else
  47                 printk (KERN_ERR "cio_setup : invalid cio_msg parameter '%s'",
  48                         parm);
  49         return 1;
  50 }
  51
  52 __setup ("cio_msg=", cio_setup);
  53
  54 /*
  55  * Function: cio_debug_init
  56  * Initializes three debug logs (under /proc/s390dbf) for common I/O:
  57  * - cio_msg logs the messages which are printk'ed when CONFIG_DEBUG_IO is on
  58  * - cio_trace logs the calling of different functions
  59  * - cio_crw logs the messages which are printk'ed when CONFIG_DEBUG_CRW is on
  60  * debug levels depend on CONFIG_DEBUG_IO resp. CONFIG_DEBUG_CRW
  61  */
  62 static int __init
  63 cio_debug_init (void)
  64 {
  65         cio_debug_msg_id = debug_register ("cio_msg", 16, 4, 16*sizeof (long));
  66         if (!cio_debug_msg_id)
  67                 goto out_unregister;
  68         debug_register_view (cio_debug_msg_id, &debug_sprintf_view);
  69         debug_set_level (cio_debug_msg_id, 2);
  70         cio_debug_trace_id = debug_register ("cio_trace", 16, 4, 16);
  71         if (!cio_debug_trace_id)
  72                 goto out_unregister;
  73         debug_register_view (cio_debug_trace_id, &debug_hex_ascii_view);
  74         debug_set_level (cio_debug_trace_id, 2);
  75         cio_debug_crw_id = debug_register ("cio_crw", 4, 4, 16*sizeof (long));
  76         if (!cio_debug_crw_id)
  77                 goto out_unregister;
  78         debug_register_view (cio_debug_crw_id, &debug_sprintf_view);
  79         debug_set_level (cio_debug_crw_id, 2);
  80         pr_debug("debugging initialized\n");
  81         return 0;
  82
  83 out_unregister:
  84         if (cio_debug_msg_id)
  85                 debug_unregister (cio_debug_msg_id);
  86         if (cio_debug_trace_id)
  87                 debug_unregister (cio_debug_trace_id);
  88         if (cio_debug_crw_id)
  89                 debug_unregister (cio_debug_crw_id);
  90         pr_debug("could not initialize debugging\n");
  91         return -1;
  92 }
  93
  94 arch_initcall (cio_debug_init);
  95
  96 int
  97 cio_set_options (struct subchannel *sch, int flags)
  98 {
  99        sch->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
 100        sch->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
 101        sch->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
 102        return 0;
 103 }
 104
 105 /* FIXME: who wants to use this? */
 106 int
 107 cio_get_options (struct subchannel *sch)
 108 {
 109        int flags;
 110
 111        flags = 0;
 112        if (sch->options.suspend)
 113                 flags |= DOIO_ALLOW_SUSPEND;
 114        if (sch->options.prefetch)
 115                 flags |= DOIO_DENY_PREFETCH;
 116        if (sch->options.inter)
 117                 flags |= DOIO_SUPPRESS_INTER;
 118        return flags;
 119 }
 120
 121 /*
 122  * Use tpi to get a pending interrupt, call the interrupt handler and
 123  * return a pointer to the subchannel structure.
 124  */
 125 static inline int
 126 cio_tpi(void)
 127 {
 128         struct tpi_info *tpi_info;
 129         struct subchannel *sch;
 130         struct irb *irb;
 131
 132         tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
 133         if (tpi (NULL) != 1)
 134                 return 0;
 135         irb = (struct irb *) __LC_IRB;
 136         /* Store interrupt response block to lowcore. */
 137         if (tsch (tpi_info->schid, irb) != 0)
 138                 /* Not status pending or not operational. */
 139                 return 1;
 140         sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 141         if (!sch)
 142                 return 1;
 143         local_bh_disable();
 144         irq_enter ();
 145         spin_lock(&sch->lock);
 146         memcpy (&sch->schib.scsw, &irb->scsw, sizeof (struct scsw));
 147         if (sch->driver && sch->driver->irq)
 148                 sch->driver->irq(&sch->dev);
 149         spin_unlock(&sch->lock);
 150         irq_exit ();
 151         __local_bh_enable();
 152         return 1;
 153 }
 154
 155 static inline int
 156 cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
 157 {
 158         char dbf_text[15];
 159
 160         if (lpm != 0)
 161                 sch->lpm &= ~lpm;
 162         else
 163                 sch->lpm = 0;
 164
 165         stsch (sch->schid, &sch->schib);
 166
 167         CIO_MSG_EVENT(0, "cio_start: 'not oper' status for "
 168                       "subchannel 0.%x.%04x!\n", sch->schid.ssid,
 169                       sch->schid.sch_no);
 170         sprintf(dbf_text, "no%s", sch->dev.bus_id);
 171         CIO_TRACE_EVENT(0, dbf_text);
 172         CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
 173
 174         return (sch->lpm ? -EACCES : -ENODEV);
 175 }
 176
 177 int
 178 cio_start_key (struct subchannel *sch,  /* subchannel structure */
 179                struct ccw1 * cpa,       /* logical channel prog addr */
 180                __u8 lpm,                /* logical path mask */
 181                __u8 key)                /* storage key */
 182 {
 183         char dbf_txt[15];
 184         int ccode;
 185
 186         CIO_TRACE_EVENT (4, "stIO");
 187         CIO_TRACE_EVENT (4, sch->dev.bus_id);
 188
 189         /* sch is always under 2G. */
 190         sch->orb.intparm = (__u32)(unsigned long)sch;
 191         sch->orb.fmt = 1;
 192
 193         sch->orb.pfch = sch->options.prefetch == 0;
 194         sch->orb.spnd = sch->options.suspend;
 195         sch->orb.ssic = sch->options.suspend && sch->options.inter;
 196         sch->orb.lpm = (lpm != 0) ? (lpm & sch->opm) : sch->lpm;
 197 #ifdef CONFIG_64BIT
 198         /*
 199          * for 64 bit we always support 64 bit IDAWs with 4k page size only
 200          */
 201         sch->orb.c64 = 1;
 202         sch->orb.i2k = 0;
 203 #endif
 204         sch->orb.key = key >> 4;
 205         /* issue "Start Subchannel" */
 206         sch->orb.cpa = (__u32) __pa (cpa);
 207         ccode = ssch (sch->schid, &sch->orb);
 208
 209         /* process condition code */
 210         sprintf (dbf_txt, "ccode:%d", ccode);
 211         CIO_TRACE_EVENT (4, dbf_txt);
 212
 213         switch (ccode) {
 214         case 0:
 215                 /*
 216                  * initialize device status information
 217                  */
 218                 sch->schib.scsw.actl |= SCSW_ACTL_START_PEND;
 219                 return 0;
 220         case 1:         /* status pending */
 221         case 2:         /* busy */
 222                 return -EBUSY;
 223         default:                /* device/path not operational */
 224                 return cio_start_handle_notoper(sch, lpm);
 225         }
 226 }
 227
 228 int
 229 cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
 230 {
 231         return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
 232 }
 233
 234 /*
 235  * resume suspended I/O operation
 236  */
 237 int
 238 cio_resume (struct subchannel *sch)
 239 {
 240         char dbf_txt[15];
 241         int ccode;
 242
 243         CIO_TRACE_EVENT (4, "resIO");
 244         CIO_TRACE_EVENT (4, sch->dev.bus_id);
 245
 246         ccode = rsch (sch->schid);
 247
 248         sprintf (dbf_txt, "ccode:%d", ccode);
 249         CIO_TRACE_EVENT (4, dbf_txt);
 250
 251         switch (ccode) {
 252         case 0:
 253                 sch->schib.scsw.actl |= SCSW_ACTL_RESUME_PEND;
 254                 return 0;
 255         case 1:
 256                 return -EBUSY;
 257         case 2:
 258                 return -EINVAL;
 259         default:
 260                 /*
 261                  * useless to wait for request completion
 262                  *  as device is no longer operational !
 263                  */
 264                 return -ENODEV;
 265         }
 266 }
 267
 268 /*
 269  * halt I/O operation
 270  */
 271 int
 272 cio_halt(struct subchannel *sch)
 273 {
 274         char dbf_txt[15];
 275         int ccode;
 276
 277         if (!sch)
 278                 return -ENODEV;
 279
 280         CIO_TRACE_EVENT (2, "haltIO");
 281         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 282
 283         /*
 284          * Issue "Halt subchannel" and process condition code
 285          */
 286         ccode = hsch (sch->schid);
 287
 288         sprintf (dbf_txt, "ccode:%d", ccode);
 289         CIO_TRACE_EVENT (2, dbf_txt);
 290
 291         switch (ccode) {
 292         case 0:
 293                 sch->schib.scsw.actl |= SCSW_ACTL_HALT_PEND;
 294                 return 0;
 295         case 1:         /* status pending */
 296         case 2:         /* busy */
 297                 return -EBUSY;
 298         default:                /* device not operational */
 299                 return -ENODEV;
 300         }
 301 }
 302
 303 /*
 304  * Clear I/O operation
 305  */
 306 int
 307 cio_clear(struct subchannel *sch)
 308 {
 309         char dbf_txt[15];
 310         int ccode;
 311
 312         if (!sch)
 313                 return -ENODEV;
 314
 315         CIO_TRACE_EVENT (2, "clearIO");
 316         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 317
 318         /*
 319          * Issue "Clear subchannel" and process condition code
 320          */
 321         ccode = csch (sch->schid);
 322
 323         sprintf (dbf_txt, "ccode:%d", ccode);
 324         CIO_TRACE_EVENT (2, dbf_txt);
 325
 326         switch (ccode) {
 327         case 0:
 328                 sch->schib.scsw.actl |= SCSW_ACTL_CLEAR_PEND;
 329                 return 0;
 330         default:                /* device not operational */
 331                 return -ENODEV;
 332         }
 333 }
 334
 335 /*
 336  * Function: cio_cancel
 337  * Issues a "Cancel Subchannel" on the specified subchannel
 338  * Note: We don't need any fancy intparms and flags here
 339  *       since xsch is executed synchronously.
 340  * Only for common I/O internal use as for now.
 341  */
 342 int
 343 cio_cancel (struct subchannel *sch)
 344 {
 345         char dbf_txt[15];
 346         int ccode;
 347
 348         if (!sch)
 349                 return -ENODEV;
 350
 351         CIO_TRACE_EVENT (2, "cancelIO");
 352         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 353
 354         ccode = xsch (sch->schid);
 355
 356         sprintf (dbf_txt, "ccode:%d", ccode);
 357         CIO_TRACE_EVENT (2, dbf_txt);
 358
 359         switch (ccode) {
 360         case 0:         /* success */
 361                 /* Update information in scsw. */
 362                 stsch (sch->schid, &sch->schib);
 363                 return 0;
 364         case 1:         /* status pending */
 365                 return -EBUSY;
 366         case 2:         /* not applicable */
 367                 return -EINVAL;
 368         default:        /* not oper */
 369                 return -ENODEV;
 370         }
 371 }
 372
 373 /*
 374  * Function: cio_modify
 375  * Issues a "Modify Subchannel" on the specified subchannel
 376  */
 377 int
 378 cio_modify (struct subchannel *sch)
 379 {
 380         int ccode, retry, ret;
 381
 382         ret = 0;
 383         for (retry = 0; retry < 5; retry++) {
 384                 ccode = msch_err (sch->schid, &sch->schib);
 385                 if (ccode < 0)  /* -EIO if msch gets a program check. */
 386                         return ccode;
 387                 switch (ccode) {
 388                 case 0: /* successfull */
 389                         return 0;
 390                 case 1: /* status pending */
 391                         return -EBUSY;
 392                 case 2: /* busy */
 393                         udelay (100);   /* allow for recovery */
 394                         ret = -EBUSY;
 395                         break;
 396                 case 3: /* not operational */
 397                         return -ENODEV;
 398                 }
 399         }
 400         return ret;
 401 }
 402
 403 /*
 404  * Enable subchannel.
 405  */
 406 int
 407 cio_enable_subchannel (struct subchannel *sch, unsigned int isc)
 408 {
 409         char dbf_txt[15];
 410         int ccode;
 411         int retry;
 412         int ret;
 413
 414         CIO_TRACE_EVENT (2, "ensch");
 415         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 416
 417         ccode = stsch (sch->schid, &sch->schib);
 418         if (ccode)
 419                 return -ENODEV;
 420
 421         for (retry = 5, ret = 0; retry > 0; retry--) {
 422                 sch->schib.pmcw.ena = 1;
 423                 sch->schib.pmcw.isc = isc;
 424                 sch->schib.pmcw.intparm = (__u32)(unsigned long)sch;
 425                 ret = cio_modify(sch);
 426                 if (ret == -ENODEV)
 427                         break;
 428                 if (ret == -EIO)
 429                         /*
 430                          * Got a program check in cio_modify. Try without
 431                          * the concurrent sense bit the next time.
 432                          */
 433                         sch->schib.pmcw.csense = 0;
 434                 if (ret == 0) {
 435                         stsch (sch->schid, &sch->schib);
 436                         if (sch->schib.pmcw.ena)
 437                                 break;
 438                 }
 439                 if (ret == -EBUSY) {
 440                         struct irb irb;
 441                         if (tsch(sch->schid, &irb) != 0)
 442                                 break;
 443                 }
 444         }
 445         sprintf (dbf_txt, "ret:%d", ret);
 446         CIO_TRACE_EVENT (2, dbf_txt);
 447         return ret;
 448 }
 449
 450 /*
 451  * Disable subchannel.
 452  */
 453 int
 454 cio_disable_subchannel (struct subchannel *sch)
 455 {
 456         char dbf_txt[15];
 457         int ccode;
 458         int retry;
 459         int ret;
 460
 461         CIO_TRACE_EVENT (2, "dissch");
 462         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 463
 464         ccode = stsch (sch->schid, &sch->schib);
 465         if (ccode == 3)         /* Not operational. */
 466                 return -ENODEV;
 467
 468         if (sch->schib.scsw.actl != 0)
 469                 /*
 470                  * the disable function must not be called while there are
 471                  *  requests pending for completion !
 472                  */
 473                 return -EBUSY;
 474
 475         for (retry = 5, ret = 0; retry > 0; retry--) {
 476                 sch->schib.pmcw.ena = 0;
 477                 ret = cio_modify(sch);
 478                 if (ret == -ENODEV)
 479                         break;
 480                 if (ret == -EBUSY)
 481                         /*
 482                          * The subchannel is busy or status pending.
 483                          * We'll disable when the next interrupt was delivered
 484                          * via the state machine.
 485                          */
 486                         break;
 487                 if (ret == 0) {
 488                         stsch (sch->schid, &sch->schib);
 489                         if (!sch->schib.pmcw.ena)
 490                                 break;
 491                 }
 492         }
 493         sprintf (dbf_txt, "ret:%d", ret);
 494         CIO_TRACE_EVENT (2, dbf_txt);
 495         return ret;
 496 }
 497
 498 /*
 499  * cio_validate_subchannel()
 500  *
 501  * Find out subchannel type and initialize struct subchannel.
 502  * Return codes:
 503  *   SUBCHANNEL_TYPE_IO for a normal io subchannel
 504  *   SUBCHANNEL_TYPE_CHSC for a chsc subchannel
 505  *   SUBCHANNEL_TYPE_MESSAGE for a messaging subchannel
 506  *   SUBCHANNEL_TYPE_ADM for a adm(?) subchannel
 507  *   -ENXIO for non-defined subchannels
 508  *   -ENODEV for subchannels with invalid device number or blacklisted devices
 509  */
 510 int
 511 cio_validate_subchannel (struct subchannel *sch, struct subchannel_id schid)
 512 {
 513         char dbf_txt[15];
 514         int ccode;
 515
 516         sprintf (dbf_txt, "valsch%x", schid.sch_no);
 517         CIO_TRACE_EVENT (4, dbf_txt);
 518
 519         /* Nuke all fields. */
 520         memset(sch, 0, sizeof(struct subchannel));
 521
 522         spin_lock_init(&sch->lock);
 523
 524         /* Set a name for the subchannel */
 525         snprintf (sch->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x", schid.ssid,
 526                   schid.sch_no);
 527
 528         /*
 529          * The first subchannel that is not-operational (ccode==3)
 530          *  indicates that there aren't any more devices available.
 531          * If stsch gets an exception, it means the current subchannel set
 532          *  is not valid.
 533          */
 534         ccode = stsch_err (schid, &sch->schib);
 535         if (ccode)
 536                 return (ccode == 3) ? -ENXIO : ccode;
 537
 538         sch->schid = schid;
 539         /* Copy subchannel type from path management control word. */
 540         sch->st = sch->schib.pmcw.st;
 541
 542         /*
 543          * ... just being curious we check for non I/O subchannels
 544          */
 545         if (sch->st != 0) {
 546                 CIO_DEBUG(KERN_INFO, 0,
 547                           "Subchannel 0.%x.%04x reports "
 548                           "non-I/O subchannel type %04X\n",
 549                           sch->schid.ssid, sch->schid.sch_no, sch->st);
 550                 /* We stop here for non-io subchannels. */
 551                 return sch->st;
 552         }
 553
 554         /* Initialization for io subchannels. */
 555         if (!sch->schib.pmcw.dnv)
 556                 /* io subchannel but device number is invalid. */
 557                 return -ENODEV;
 558
 559         /* Devno is valid. */
 560         if (is_blacklisted (sch->schid.ssid, sch->schib.pmcw.dev)) {
 561                 /*
 562                  * This device must not be known to Linux. So we simply
 563                  * say that there is no device and return ENODEV.
 564                  */
 565                 CIO_MSG_EVENT(0, "Blacklisted device detected "
 566                               "at devno %04X, subchannel set %x\n",
 567                               sch->schib.pmcw.dev, sch->schid.ssid);
 568                 return -ENODEV;
 569         }
 570         sch->opm = 0xff;
 571         if (!cio_is_console(sch->schid))
 572                 chsc_validate_chpids(sch);
 573         sch->lpm = sch->schib.pmcw.pim &
 574                 sch->schib.pmcw.pam &
 575                 sch->schib.pmcw.pom &
 576                 sch->opm;
 577
 578         CIO_DEBUG(KERN_INFO, 0,
 579                   "Detected device %04x on subchannel 0.%x.%04X"
 580                   " - PIM = %02X, PAM = %02X, POM = %02X\n",
 581                   sch->schib.pmcw.dev, sch->schid.ssid,
 582                   sch->schid.sch_no, sch->schib.pmcw.pim,
 583                   sch->schib.pmcw.pam, sch->schib.pmcw.pom);
 584
 585         /*
 586          * We now have to initially ...
 587          *  ... set "interruption subclass"
 588          *  ... enable "concurrent sense"
 589          *  ... enable "multipath mode" if more than one
 590          *        CHPID is available. This is done regardless
 591          *        whether multiple paths are available for us.
 592          */
 593         sch->schib.pmcw.isc = 3;        /* could be smth. else */
 594         sch->schib.pmcw.csense = 1;     /* concurrent sense */
 595         sch->schib.pmcw.ena = 0;
 596         if ((sch->lpm & (sch->lpm - 1)) != 0)
 597                 sch->schib.pmcw.mp = 1; /* multipath mode */
 598         return 0;
 599 }
 600
 601 /*
 602  * do_IRQ() handles all normal I/O device IRQ's (the special
 603  *          SMP cross-CPU interrupts have their own specific
 604  *          handlers).
 605  *
 606  */
 607 void
 608 do_IRQ (struct pt_regs *regs)
 609 {
 610         struct tpi_info *tpi_info;
 611         struct subchannel *sch;
 612         struct irb *irb;
 613
 614         irq_enter ();
 615         asm volatile ("mc 0,0");
 616         if (S390_lowcore.int_clock >= S390_lowcore.jiffy_timer)
 617                 /**
 618                  * Make sure that the i/o interrupt did not "overtake"
 619                  * the last HZ timer interrupt.
 620                  */
 621                 account_ticks(regs);
 622         /*
 623          * Get interrupt information from lowcore
 624          */
 625         tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
 626         irb = (struct irb *) __LC_IRB;
 627         do {
 628                 kstat_cpu(smp_processor_id()).irqs[IO_INTERRUPT]++;
 629                 /*
 630                  * Non I/O-subchannel thin interrupts are processed differently
 631                  */
 632                 if (tpi_info->adapter_IO == 1 &&
 633                     tpi_info->int_type == IO_INTERRUPT_TYPE) {
 634                         do_adapter_IO();
 635                         continue;
 636                 }
 637                 sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 638                 if (sch)
 639                         spin_lock(&sch->lock);
 640                 /* Store interrupt response block to lowcore. */
 641                 if (tsch (tpi_info->schid, irb) == 0 && sch) {
 642                         /* Keep subchannel information word up to date. */
 643                         memcpy (&sch->schib.scsw, &irb->scsw,
 644                                 sizeof (irb->scsw));
 645                         /* Call interrupt handler if there is one. */
 646                         if (sch->driver && sch->driver->irq)
 647                                 sch->driver->irq(&sch->dev);
 648                 }
 649                 if (sch)
 650                         spin_unlock(&sch->lock);
 651                 /*
 652                  * Are more interrupts pending?
 653                  * If so, the tpi instruction will update the lowcore
 654                  * to hold the info for the next interrupt.
 655                  * We don't do this for VM because a tpi drops the cpu
 656                  * out of the sie which costs more cycles than it saves.
 657                  */
 658         } while (!MACHINE_IS_VM && tpi (NULL) != 0);
 659         irq_exit ();
 660 }
 661
 662 #ifdef CONFIG_CCW_CONSOLE
 663 static struct subchannel console_subchannel;
 664 static int console_subchannel_in_use;
 665
 666 /*
 667  * busy wait for the next interrupt on the console
 668  */
 669 void
 670 wait_cons_dev (void)
 671 {
 672         unsigned long cr6      __attribute__ ((aligned (8)));
 673         unsigned long save_cr6 __attribute__ ((aligned (8)));
 674
 675         /*
 676          * before entering the spinlock we may already have
 677          * processed the interrupt on a different CPU...
 678          */
 679         if (!console_subchannel_in_use)
 680                 return;
 681
 682         /* disable all but isc 7 (console device) */
 683         __ctl_store (save_cr6, 6, 6);
 684         cr6 = 0x01000000;
 685         __ctl_load (cr6, 6, 6);
 686
 687         do {
 688                 spin_unlock(&console_subchannel.lock);
 689                 if (!cio_tpi())
 690                         cpu_relax();
 691                 spin_lock(&console_subchannel.lock);
 692         } while (console_subchannel.schib.scsw.actl != 0);
 693         /*
 694          * restore previous isc value
 695          */
 696         __ctl_load (save_cr6, 6, 6);
 697 }
 698
 699 static int
 700 cio_test_for_console(struct subchannel_id schid, void *data)
 701 {
 702         if (stsch_err(schid, &console_subchannel.schib) != 0)
 703                 return -ENXIO;
 704         if (console_subchannel.schib.pmcw.dnv &&
 705             console_subchannel.schib.pmcw.dev ==
 706             console_devno) {
 707                 console_irq = schid.sch_no;
 708                 return 1; /* found */
 709         }
 710         return 0;
 711 }
 712
 713
 714 static int
 715 cio_get_console_sch_no(void)
 716 {
 717         struct subchannel_id schid;
 718
 719         init_subchannel_id(&schid);
 720         if (console_irq != -1) {
 721                 /* VM provided us with the irq number of the console. */
 722                 schid.sch_no = console_irq;
 723                 if (stsch(schid, &console_subchannel.schib) != 0 ||
 724                     !console_subchannel.schib.pmcw.dnv)
 725                         return -1;
 726                 console_devno = console_subchannel.schib.pmcw.dev;
 727         } else if (console_devno != -1) {
 728                 /* At least the console device number is known. */
 729                 for_each_subchannel(cio_test_for_console, NULL);
 730                 if (console_irq == -1)
 731                         return -1;
 732         } else {
 733                 /* unlike in 2.4, we cannot autoprobe here, since
 734                  * the channel subsystem is not fully initialized.
 735                  * With some luck, the HWC console can take over */
 736                 printk(KERN_WARNING "No ccw console found!\n");
 737                 return -1;
 738         }
 739         return console_irq;
 740 }
 741
 742 struct subchannel *
 743 cio_probe_console(void)
 744 {
 745         int sch_no, ret;
 746         struct subchannel_id schid;
 747
 748         if (xchg(&console_subchannel_in_use, 1) != 0)
 749                 return ERR_PTR(-EBUSY);
 750         sch_no = cio_get_console_sch_no();
 751         if (sch_no == -1) {
 752                 console_subchannel_in_use = 0;
 753                 return ERR_PTR(-ENODEV);
 754         }
 755         memset(&console_subchannel, 0, sizeof(struct subchannel));
 756         init_subchannel_id(&schid);
 757         schid.sch_no = sch_no;
 758         ret = cio_validate_subchannel(&console_subchannel, schid);
 759         if (ret) {
 760                 console_subchannel_in_use = 0;
 761                 return ERR_PTR(-ENODEV);
 762         }
 763
 764         /*
 765          * enable console I/O-interrupt subclass 7
 766          */
 767         ctl_set_bit(6, 24);
 768         console_subchannel.schib.pmcw.isc = 7;
 769         console_subchannel.schib.pmcw.intparm =
 770                 (__u32)(unsigned long)&console_subchannel;
 771         ret = cio_modify(&console_subchannel);
 772         if (ret) {
 773                 console_subchannel_in_use = 0;
 774                 return ERR_PTR(ret);
 775         }
 776         return &console_subchannel;
 777 }
 778
 779 void
 780 cio_release_console(void)
 781 {
 782         console_subchannel.schib.pmcw.intparm = 0;
 783         cio_modify(&console_subchannel);
 784         ctl_clear_bit(6, 24);
 785         console_subchannel_in_use = 0;
 786 }
 787
 788 /* Bah... hack to catch console special sausages. */
 789 int
 790 cio_is_console(struct subchannel_id schid)
 791 {
 792         if (!console_subchannel_in_use)
 793                 return 0;
 794         return schid_equal(&schid, &console_subchannel.schid);
 795 }
 796
 797 struct subchannel *
 798 cio_get_console_subchannel(void)
 799 {
 800         if (!console_subchannel_in_use)
 801                 return 0;
 802         return &console_subchannel;
 803 }
 804
 805 #endif
 806 static inline int
 807 __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
 808 {
 809         int retry, cc;
 810
 811         cc = 0;
 812         for (retry=0;retry<3;retry++) {
 813                 schib->pmcw.ena = 0;
 814                 cc = msch(schid, schib);
 815                 if (cc)
 816                         return (cc==3?-ENODEV:-EBUSY);
 817                 stsch(schid, schib);
 818                 if (!schib->pmcw.ena)
 819                         return 0;
 820         }
 821         return -EBUSY; /* uhm... */
 822 }
 823
 824 static inline int
 825 __clear_subchannel_easy(struct subchannel_id schid)
 826 {
 827         int retry;
 828
 829         if (csch(schid))
 830                 return -ENODEV;
 831         for (retry=0;retry<20;retry++) {
 832                 struct tpi_info ti;
 833
 834                 if (tpi(&ti)) {
 835                         tsch(ti.schid, (struct irb *)__LC_IRB);
 836                         if (schid_equal(&ti.schid, &schid))
 837                                 return 0;
 838                 }
 839                 udelay(100);
 840         }
 841         return -EBUSY;
 842 }
 843
 844 extern void do_reipl(unsigned long devno);
 845 static int
 846 __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
 847 {
 848         struct schib schib;
 849
 850         if (stsch_err(schid, &schib))
 851                 return -ENXIO;
 852         if (!schib.pmcw.ena)
 853                 return 0;
 854         switch(__disable_subchannel_easy(schid, &schib)) {
 855         case 0:
 856         case -ENODEV:
 857                 break;
 858         default: /* -EBUSY */
 859                 if (__clear_subchannel_easy(schid))
 860                         break; /* give up... */
 861                 stsch(schid, &schib);
 862                 __disable_subchannel_easy(schid, &schib);
 863         }
 864         return 0;
 865 }
 866
 867 void
 868 clear_all_subchannels(void)
 869 {
 870         local_irq_disable();
 871         for_each_subchannel(__shutdown_subchannel_easy, NULL);
 872 }
 873
 874 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
 875 void
 876 reipl(unsigned long devno)
 877 {
 878         clear_all_subchannels();
 879         do_reipl(devno);
 880 }