drivers/s390/cio/cio.c

   1 /*
   2  *  drivers/s390/cio/cio.c
   3  *   S/390 common I/O routines -- low level i/o calls
   4  *
   5  *    Copyright IBM Corp. 1999,2008
   6  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
   7  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   8  *               Arnd Bergmann (arndb@de.ibm.com)
   9  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
  10  */
  11
  12 #define KMSG_COMPONENT "cio"
  13 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  14
  15 #include <linux/ftrace.h>
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/slab.h>
  19 #include <linux/device.h>
  20 #include <linux/kernel_stat.h>
  21 #include <linux/interrupt.h>
  22 #include <asm/cio.h>
  23 #include <asm/delay.h>
  24 #include <asm/irq.h>
  25 #include <asm/irq_regs.h>
  26 #include <asm/setup.h>
  27 #include <asm/reset.h>
  28 #include <asm/ipl.h>
  29 #include <asm/chpid.h>
  30 #include <asm/airq.h>
  31 #include <asm/isc.h>
  32 #include <asm/cputime.h>
  33 #include <asm/fcx.h>
  34 #include <asm/nmi.h>
  35 #include <asm/crw.h>
  36 #include "cio.h"
  37 #include "css.h"
  38 #include "chsc.h"
  39 #include "ioasm.h"
  40 #include "io_sch.h"
  41 #include "blacklist.h"
  42 #include "cio_debug.h"
  43 #include "chp.h"
  44
  45 debug_info_t *cio_debug_msg_id;
  46 debug_info_t *cio_debug_trace_id;
  47 debug_info_t *cio_debug_crw_id;
  48
  49 /*
  50  * Function: cio_debug_init
  51  * Initializes three debug logs for common I/O:
  52  * - cio_msg logs generic cio messages
  53  * - cio_trace logs the calling of different functions
  54  * - cio_crw logs machine check related cio messages
  55  */
  56 static int __init cio_debug_init(void)
  57 {
  58         cio_debug_msg_id = debug_register("cio_msg", 16, 1, 16 * sizeof(long));
  59         if (!cio_debug_msg_id)
  60                 goto out_unregister;
  61         debug_register_view(cio_debug_msg_id, &debug_sprintf_view);
  62         debug_set_level(cio_debug_msg_id, 2);
  63         cio_debug_trace_id = debug_register("cio_trace", 16, 1, 16);
  64         if (!cio_debug_trace_id)
  65                 goto out_unregister;
  66         debug_register_view(cio_debug_trace_id, &debug_hex_ascii_view);
  67         debug_set_level(cio_debug_trace_id, 2);
  68         cio_debug_crw_id = debug_register("cio_crw", 16, 1, 16 * sizeof(long));
  69         if (!cio_debug_crw_id)
  70                 goto out_unregister;
  71         debug_register_view(cio_debug_crw_id, &debug_sprintf_view);
  72         debug_set_level(cio_debug_crw_id, 4);
  73         return 0;
  74
  75 out_unregister:
  76         if (cio_debug_msg_id)
  77                 debug_unregister(cio_debug_msg_id);
  78         if (cio_debug_trace_id)
  79                 debug_unregister(cio_debug_trace_id);
  80         if (cio_debug_crw_id)
  81                 debug_unregister(cio_debug_crw_id);
  82         return -1;
  83 }
  84
  85 arch_initcall (cio_debug_init);
  86
  87 int
  88 cio_set_options (struct subchannel *sch, int flags)
  89 {
  90        sch->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
  91        sch->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
  92        sch->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
  93        return 0;
  94 }
  95
  96 /* FIXME: who wants to use this? */
  97 int
  98 cio_get_options (struct subchannel *sch)
  99 {
 100        int flags;
 101
 102        flags = 0;
 103        if (sch->options.suspend)
 104                 flags |= DOIO_ALLOW_SUSPEND;
 105        if (sch->options.prefetch)
 106                 flags |= DOIO_DENY_PREFETCH;
 107        if (sch->options.inter)
 108                 flags |= DOIO_SUPPRESS_INTER;
 109        return flags;
 110 }
 111
 112 static int
 113 cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
 114 {
 115         char dbf_text[15];
 116
 117         if (lpm != 0)
 118                 sch->lpm &= ~lpm;
 119         else
 120                 sch->lpm = 0;
 121
 122         CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
 123                       "subchannel 0.%x.%04x!\n", sch->schid.ssid,
 124                       sch->schid.sch_no);
 125
 126         if (cio_update_schib(sch))
 127                 return -ENODEV;
 128
 129         sprintf(dbf_text, "no%s", dev_name(&sch->dev));
 130         CIO_TRACE_EVENT(0, dbf_text);
 131         CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
 132
 133         return (sch->lpm ? -EACCES : -ENODEV);
 134 }
 135
 136 int
 137 cio_start_key (struct subchannel *sch,  /* subchannel structure */
 138                struct ccw1 * cpa,       /* logical channel prog addr */
 139                __u8 lpm,                /* logical path mask */
 140                __u8 key)                /* storage key */
 141 {
 142         char dbf_txt[15];
 143         int ccode;
 144         union orb *orb;
 145
 146         CIO_TRACE_EVENT(4, "stIO");
 147         CIO_TRACE_EVENT(4, dev_name(&sch->dev));
 148
 149         orb = &to_io_private(sch)->orb;
 150         memset(orb, 0, sizeof(union orb));
 151         /* sch is always under 2G. */
 152         orb->cmd.intparm = (u32)(addr_t)sch;
 153         orb->cmd.fmt = 1;
 154
 155         orb->cmd.pfch = sch->options.prefetch == 0;
 156         orb->cmd.spnd = sch->options.suspend;
 157         orb->cmd.ssic = sch->options.suspend && sch->options.inter;
 158         orb->cmd.lpm = (lpm != 0) ? lpm : sch->lpm;
 159 #ifdef CONFIG_64BIT
 160         /*
 161          * for 64 bit we always support 64 bit IDAWs with 4k page size only
 162          */
 163         orb->cmd.c64 = 1;
 164         orb->cmd.i2k = 0;
 165 #endif
 166         orb->cmd.key = key >> 4;
 167         /* issue "Start Subchannel" */
 168         orb->cmd.cpa = (__u32) __pa(cpa);
 169         ccode = ssch(sch->schid, orb);
 170
 171         /* process condition code */
 172         sprintf(dbf_txt, "ccode:%d", ccode);
 173         CIO_TRACE_EVENT(4, dbf_txt);
 174
 175         switch (ccode) {
 176         case 0:
 177                 /*
 178                  * initialize device status information
 179                  */
 180                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
 181                 return 0;
 182         case 1:         /* status pending */
 183         case 2:         /* busy */
 184                 return -EBUSY;
 185         case 3:         /* device/path not operational */
 186                 return cio_start_handle_notoper(sch, lpm);
 187         default:
 188                 return ccode;
 189         }
 190 }
 191
 192 int
 193 cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
 194 {
 195         return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
 196 }
 197
 198 /*
 199  * resume suspended I/O operation
 200  */
 201 int
 202 cio_resume (struct subchannel *sch)
 203 {
 204         char dbf_txt[15];
 205         int ccode;
 206
 207         CIO_TRACE_EVENT (4, "resIO");
 208         CIO_TRACE_EVENT(4, dev_name(&sch->dev));
 209
 210         ccode = rsch (sch->schid);
 211
 212         sprintf (dbf_txt, "ccode:%d", ccode);
 213         CIO_TRACE_EVENT (4, dbf_txt);
 214
 215         switch (ccode) {
 216         case 0:
 217                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_RESUME_PEND;
 218                 return 0;
 219         case 1:
 220                 return -EBUSY;
 221         case 2:
 222                 return -EINVAL;
 223         default:
 224                 /*
 225                  * useless to wait for request completion
 226                  *  as device is no longer operational !
 227                  */
 228                 return -ENODEV;
 229         }
 230 }
 231
 232 /*
 233  * halt I/O operation
 234  */
 235 int
 236 cio_halt(struct subchannel *sch)
 237 {
 238         char dbf_txt[15];
 239         int ccode;
 240
 241         if (!sch)
 242                 return -ENODEV;
 243
 244         CIO_TRACE_EVENT (2, "haltIO");
 245         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 246
 247         /*
 248          * Issue "Halt subchannel" and process condition code
 249          */
 250         ccode = hsch (sch->schid);
 251
 252         sprintf (dbf_txt, "ccode:%d", ccode);
 253         CIO_TRACE_EVENT (2, dbf_txt);
 254
 255         switch (ccode) {
 256         case 0:
 257                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND;
 258                 return 0;
 259         case 1:         /* status pending */
 260         case 2:         /* busy */
 261                 return -EBUSY;
 262         default:                /* device not operational */
 263                 return -ENODEV;
 264         }
 265 }
 266
 267 /*
 268  * Clear I/O operation
 269  */
 270 int
 271 cio_clear(struct subchannel *sch)
 272 {
 273         char dbf_txt[15];
 274         int ccode;
 275
 276         if (!sch)
 277                 return -ENODEV;
 278
 279         CIO_TRACE_EVENT (2, "clearIO");
 280         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 281
 282         /*
 283          * Issue "Clear subchannel" and process condition code
 284          */
 285         ccode = csch (sch->schid);
 286
 287         sprintf (dbf_txt, "ccode:%d", ccode);
 288         CIO_TRACE_EVENT (2, dbf_txt);
 289
 290         switch (ccode) {
 291         case 0:
 292                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_CLEAR_PEND;
 293                 return 0;
 294         default:                /* device not operational */
 295                 return -ENODEV;
 296         }
 297 }
 298
 299 /*
 300  * Function: cio_cancel
 301  * Issues a "Cancel Subchannel" on the specified subchannel
 302  * Note: We don't need any fancy intparms and flags here
 303  *       since xsch is executed synchronously.
 304  * Only for common I/O internal use as for now.
 305  */
 306 int
 307 cio_cancel (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, "cancelIO");
 316         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 317
 318         ccode = xsch (sch->schid);
 319
 320         sprintf (dbf_txt, "ccode:%d", ccode);
 321         CIO_TRACE_EVENT (2, dbf_txt);
 322
 323         switch (ccode) {
 324         case 0:         /* success */
 325                 /* Update information in scsw. */
 326                 if (cio_update_schib(sch))
 327                         return -ENODEV;
 328                 return 0;
 329         case 1:         /* status pending */
 330                 return -EBUSY;
 331         case 2:         /* not applicable */
 332                 return -EINVAL;
 333         default:        /* not oper */
 334                 return -ENODEV;
 335         }
 336 }
 337
 338
 339 static void cio_apply_config(struct subchannel *sch, struct schib *schib)
 340 {
 341         schib->pmcw.intparm = sch->config.intparm;
 342         schib->pmcw.mbi = sch->config.mbi;
 343         schib->pmcw.isc = sch->config.isc;
 344         schib->pmcw.ena = sch->config.ena;
 345         schib->pmcw.mme = sch->config.mme;
 346         schib->pmcw.mp = sch->config.mp;
 347         schib->pmcw.csense = sch->config.csense;
 348         schib->pmcw.mbfc = sch->config.mbfc;
 349         if (sch->config.mbfc)
 350                 schib->mba = sch->config.mba;
 351 }
 352
 353 static int cio_check_config(struct subchannel *sch, struct schib *schib)
 354 {
 355         return (schib->pmcw.intparm == sch->config.intparm) &&
 356                 (schib->pmcw.mbi == sch->config.mbi) &&
 357                 (schib->pmcw.isc == sch->config.isc) &&
 358                 (schib->pmcw.ena == sch->config.ena) &&
 359                 (schib->pmcw.mme == sch->config.mme) &&
 360                 (schib->pmcw.mp == sch->config.mp) &&
 361                 (schib->pmcw.csense == sch->config.csense) &&
 362                 (schib->pmcw.mbfc == sch->config.mbfc) &&
 363                 (!sch->config.mbfc || (schib->mba == sch->config.mba));
 364 }
 365
 366 /*
 367  * cio_commit_config - apply configuration to the subchannel
 368  */
 369 int cio_commit_config(struct subchannel *sch)
 370 {
 371         struct schib schib;
 372         int ccode, retry, ret = 0;
 373
 374         if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
 375                 return -ENODEV;
 376
 377         for (retry = 0; retry < 5; retry++) {
 378                 /* copy desired changes to local schib */
 379                 cio_apply_config(sch, &schib);
 380                 ccode = msch_err(sch->schid, &schib);
 381                 if (ccode < 0) /* -EIO if msch gets a program check. */
 382                         return ccode;
 383                 switch (ccode) {
 384                 case 0: /* successful */
 385                         if (stsch(sch->schid, &schib) ||
 386                             !css_sch_is_valid(&schib))
 387                                 return -ENODEV;
 388                         if (cio_check_config(sch, &schib)) {
 389                                 /* commit changes from local schib */
 390                                 memcpy(&sch->schib, &schib, sizeof(schib));
 391                                 return 0;
 392                         }
 393                         ret = -EAGAIN;
 394                         break;
 395                 case 1: /* status pending */
 396                         return -EBUSY;
 397                 case 2: /* busy */
 398                         udelay(100); /* allow for recovery */
 399                         ret = -EBUSY;
 400                         break;
 401                 case 3: /* not operational */
 402                         return -ENODEV;
 403                 }
 404         }
 405         return ret;
 406 }
 407
 408 /**
 409  * cio_update_schib - Perform stsch and update schib if subchannel is valid.
 410  * @sch: subchannel on which to perform stsch
 411  * Return zero on success, -ENODEV otherwise.
 412  */
 413 int cio_update_schib(struct subchannel *sch)
 414 {
 415         struct schib schib;
 416
 417         if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
 418                 return -ENODEV;
 419
 420         memcpy(&sch->schib, &schib, sizeof(schib));
 421         return 0;
 422 }
 423 EXPORT_SYMBOL_GPL(cio_update_schib);
 424
 425 /**
 426  * cio_enable_subchannel - enable a subchannel.
 427  * @sch: subchannel to be enabled
 428  * @intparm: interruption parameter to set
 429  */
 430 int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
 431 {
 432         char dbf_txt[15];
 433         int retry;
 434         int ret;
 435
 436         CIO_TRACE_EVENT (2, "ensch");
 437         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 438
 439         if (sch_is_pseudo_sch(sch))
 440                 return -EINVAL;
 441         if (cio_update_schib(sch))
 442                 return -ENODEV;
 443
 444         sch->config.ena = 1;
 445         sch->config.isc = sch->isc;
 446         sch->config.intparm = intparm;
 447
 448         for (retry = 0; retry < 3; retry++) {
 449                 ret = cio_commit_config(sch);
 450                 if (ret == -EIO) {
 451                         /*
 452                          * Got a program check in msch. Try without
 453                          * the concurrent sense bit the next time.
 454                          */
 455                         sch->config.csense = 0;
 456                 } else if (ret == -EBUSY) {
 457                         struct irb irb;
 458                         if (tsch(sch->schid, &irb) != 0)
 459                                 break;
 460                 } else
 461                         break;
 462         }
 463         sprintf (dbf_txt, "ret:%d", ret);
 464         CIO_TRACE_EVENT (2, dbf_txt);
 465         return ret;
 466 }
 467 EXPORT_SYMBOL_GPL(cio_enable_subchannel);
 468
 469 /**
 470  * cio_disable_subchannel - disable a subchannel.
 471  * @sch: subchannel to disable
 472  */
 473 int cio_disable_subchannel(struct subchannel *sch)
 474 {
 475         char dbf_txt[15];
 476         int retry;
 477         int ret;
 478
 479         CIO_TRACE_EVENT (2, "dissch");
 480         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 481
 482         if (sch_is_pseudo_sch(sch))
 483                 return 0;
 484         if (cio_update_schib(sch))
 485                 return -ENODEV;
 486
 487         sch->config.ena = 0;
 488
 489         for (retry = 0; retry < 3; retry++) {
 490                 ret = cio_commit_config(sch);
 491                 if (ret == -EBUSY) {
 492                         struct irb irb;
 493                         if (tsch(sch->schid, &irb) != 0)
 494                                 break;
 495                 } else
 496                         break;
 497         }
 498         sprintf (dbf_txt, "ret:%d", ret);
 499         CIO_TRACE_EVENT (2, dbf_txt);
 500         return ret;
 501 }
 502 EXPORT_SYMBOL_GPL(cio_disable_subchannel);
 503
 504 int cio_create_sch_lock(struct subchannel *sch)
 505 {
 506         sch->lock = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
 507         if (!sch->lock)
 508                 return -ENOMEM;
 509         spin_lock_init(sch->lock);
 510         return 0;
 511 }
 512
 513 static int cio_check_devno_blacklisted(struct subchannel *sch)
 514 {
 515         if (is_blacklisted(sch->schid.ssid, sch->schib.pmcw.dev)) {
 516                 /*
 517                  * This device must not be known to Linux. So we simply
 518                  * say that there is no device and return ENODEV.
 519                  */
 520                 CIO_MSG_EVENT(6, "Blacklisted device detected "
 521                               "at devno %04X, subchannel set %x\n",
 522                               sch->schib.pmcw.dev, sch->schid.ssid);
 523                 return -ENODEV;
 524         }
 525         return 0;
 526 }
 527
 528 static int cio_validate_io_subchannel(struct subchannel *sch)
 529 {
 530         /* Initialization for io subchannels. */
 531         if (!css_sch_is_valid(&sch->schib))
 532                 return -ENODEV;
 533
 534         /* Devno is valid. */
 535         return cio_check_devno_blacklisted(sch);
 536 }
 537
 538 static int cio_validate_msg_subchannel(struct subchannel *sch)
 539 {
 540         /* Initialization for message subchannels. */
 541         if (!css_sch_is_valid(&sch->schib))
 542                 return -ENODEV;
 543
 544         /* Devno is valid. */
 545         return cio_check_devno_blacklisted(sch);
 546 }
 547
 548 /**
 549  * cio_validate_subchannel - basic validation of subchannel
 550  * @sch: subchannel structure to be filled out
 551  * @schid: subchannel id
 552  *
 553  * Find out subchannel type and initialize struct subchannel.
 554  * Return codes:
 555  *   0 on success
 556  *   -ENXIO for non-defined subchannels
 557  *   -ENODEV for invalid subchannels or blacklisted devices
 558  *   -EIO for subchannels in an invalid subchannel set
 559  */
 560 int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
 561 {
 562         char dbf_txt[15];
 563         int ccode;
 564         int err;
 565
 566         sprintf(dbf_txt, "valsch%x", schid.sch_no);
 567         CIO_TRACE_EVENT(4, dbf_txt);
 568
 569         /* Nuke all fields. */
 570         memset(sch, 0, sizeof(struct subchannel));
 571
 572         sch->schid = schid;
 573         if (cio_is_console(schid)) {
 574                 sch->lock = cio_get_console_lock();
 575         } else {
 576                 err = cio_create_sch_lock(sch);
 577                 if (err)
 578                         goto out;
 579         }
 580         mutex_init(&sch->reg_mutex);
 581         /* Set a name for the subchannel */
 582         if (cio_is_console(schid))
 583                 sch->dev.init_name = cio_get_console_sch_name(schid);
 584         else
 585                 dev_set_name(&sch->dev, "0.%x.%04x", schid.ssid, schid.sch_no);
 586
 587         /*
 588          * The first subchannel that is not-operational (ccode==3)
 589          *  indicates that there aren't any more devices available.
 590          * If stsch gets an exception, it means the current subchannel set
 591          *  is not valid.
 592          */
 593         ccode = stsch_err (schid, &sch->schib);
 594         if (ccode) {
 595                 err = (ccode == 3) ? -ENXIO : ccode;
 596                 goto out;
 597         }
 598         /* Copy subchannel type from path management control word. */
 599         sch->st = sch->schib.pmcw.st;
 600
 601         switch (sch->st) {
 602         case SUBCHANNEL_TYPE_IO:
 603                 err = cio_validate_io_subchannel(sch);
 604                 break;
 605         case SUBCHANNEL_TYPE_MSG:
 606                 err = cio_validate_msg_subchannel(sch);
 607                 break;
 608         default:
 609                 err = 0;
 610         }
 611         if (err)
 612                 goto out;
 613
 614         CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
 615                       sch->schid.ssid, sch->schid.sch_no, sch->st);
 616         return 0;
 617 out:
 618         if (!cio_is_console(schid))
 619                 kfree(sch->lock);
 620         sch->lock = NULL;
 621         return err;
 622 }
 623
 624 /*
 625  * do_IRQ() handles all normal I/O device IRQ's (the special
 626  *          SMP cross-CPU interrupts have their own specific
 627  *          handlers).
 628  *
 629  */
 630 void __irq_entry do_IRQ(struct pt_regs *regs)
 631 {
 632         struct tpi_info *tpi_info;
 633         struct subchannel *sch;
 634         struct irb *irb;
 635         struct pt_regs *old_regs;
 636
 637         old_regs = set_irq_regs(regs);
 638         s390_idle_check();
 639         irq_enter();
 640         if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
 641                 /* Serve timer interrupts first. */
 642                 clock_comparator_work();
 643         /*
 644          * Get interrupt information from lowcore
 645          */
 646         tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
 647         irb = (struct irb *) __LC_IRB;
 648         do {
 649                 kstat_cpu(smp_processor_id()).irqs[IO_INTERRUPT]++;
 650                 /*
 651                  * Non I/O-subchannel thin interrupts are processed differently
 652                  */
 653                 if (tpi_info->adapter_IO == 1 &&
 654                     tpi_info->int_type == IO_INTERRUPT_TYPE) {
 655                         do_adapter_IO(tpi_info->isc);
 656                         continue;
 657                 }
 658                 sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 659                 if (!sch) {
 660                         /* Clear pending interrupt condition. */
 661                         tsch(tpi_info->schid, irb);
 662                         continue;
 663                 }
 664                 spin_lock(sch->lock);
 665                 /* Store interrupt response block to lowcore. */
 666                 if (tsch(tpi_info->schid, irb) == 0) {
 667                         /* Keep subchannel information word up to date. */
 668                         memcpy (&sch->schib.scsw, &irb->scsw,
 669                                 sizeof (irb->scsw));
 670                         /* Call interrupt handler if there is one. */
 671                         if (sch->driver && sch->driver->irq)
 672                                 sch->driver->irq(sch);
 673                 }
 674                 spin_unlock(sch->lock);
 675                 /*
 676                  * Are more interrupts pending?
 677                  * If so, the tpi instruction will update the lowcore
 678                  * to hold the info for the next interrupt.
 679                  * We don't do this for VM because a tpi drops the cpu
 680                  * out of the sie which costs more cycles than it saves.
 681                  */
 682         } while (!MACHINE_IS_VM && tpi (NULL) != 0);
 683         irq_exit();
 684         set_irq_regs(old_regs);
 685 }
 686
 687 #ifdef CONFIG_CCW_CONSOLE
 688 static struct subchannel console_subchannel;
 689 static char console_sch_name[10] = "0.x.xxxx";
 690 static struct io_subchannel_private console_priv;
 691 static int console_subchannel_in_use;
 692
 693 /*
 694  * Use tpi to get a pending interrupt, call the interrupt handler and
 695  * return a pointer to the subchannel structure.
 696  */
 697 static int cio_tpi(void)
 698 {
 699         struct tpi_info *tpi_info;
 700         struct subchannel *sch;
 701         struct irb *irb;
 702         int irq_context;
 703
 704         tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
 705         if (tpi(NULL) != 1)
 706                 return 0;
 707         irb = (struct irb *) __LC_IRB;
 708         /* Store interrupt response block to lowcore. */
 709         if (tsch(tpi_info->schid, irb) != 0)
 710                 /* Not status pending or not operational. */
 711                 return 1;
 712         sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 713         if (!sch)
 714                 return 1;
 715         irq_context = in_interrupt();
 716         if (!irq_context)
 717                 local_bh_disable();
 718         irq_enter();
 719         spin_lock(sch->lock);
 720         memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
 721         if (sch->driver && sch->driver->irq)
 722                 sch->driver->irq(sch);
 723         spin_unlock(sch->lock);
 724         irq_exit();
 725         if (!irq_context)
 726                 _local_bh_enable();
 727         return 1;
 728 }
 729
 730 void *cio_get_console_priv(void)
 731 {
 732         return &console_priv;
 733 }
 734
 735 /*
 736  * busy wait for the next interrupt on the console
 737  */
 738 void wait_cons_dev(void)
 739         __releases(console_subchannel.lock)
 740         __acquires(console_subchannel.lock)
 741 {
 742         unsigned long cr6      __attribute__ ((aligned (8)));
 743         unsigned long save_cr6 __attribute__ ((aligned (8)));
 744
 745         /*
 746          * before entering the spinlock we may already have
 747          * processed the interrupt on a different CPU...
 748          */
 749         if (!console_subchannel_in_use)
 750                 return;
 751
 752         /* disable all but the console isc */
 753         __ctl_store (save_cr6, 6, 6);
 754         cr6 = 1UL << (31 - CONSOLE_ISC);
 755         __ctl_load (cr6, 6, 6);
 756
 757         do {
 758                 spin_unlock(console_subchannel.lock);
 759                 if (!cio_tpi())
 760                         cpu_relax();
 761                 spin_lock(console_subchannel.lock);
 762         } while (console_subchannel.schib.scsw.cmd.actl != 0);
 763         /*
 764          * restore previous isc value
 765          */
 766         __ctl_load (save_cr6, 6, 6);
 767 }
 768
 769 static int
 770 cio_test_for_console(struct subchannel_id schid, void *data)
 771 {
 772         if (stsch_err(schid, &console_subchannel.schib) != 0)
 773                 return -ENXIO;
 774         if ((console_subchannel.schib.pmcw.st == SUBCHANNEL_TYPE_IO) &&
 775             console_subchannel.schib.pmcw.dnv &&
 776             (console_subchannel.schib.pmcw.dev == console_devno)) {
 777                 console_irq = schid.sch_no;
 778                 return 1; /* found */
 779         }
 780         return 0;
 781 }
 782
 783
 784 static int
 785 cio_get_console_sch_no(void)
 786 {
 787         struct subchannel_id schid;
 788
 789         init_subchannel_id(&schid);
 790         if (console_irq != -1) {
 791                 /* VM provided us with the irq number of the console. */
 792                 schid.sch_no = console_irq;
 793                 if (stsch(schid, &console_subchannel.schib) != 0 ||
 794                     (console_subchannel.schib.pmcw.st != SUBCHANNEL_TYPE_IO) ||
 795                     !console_subchannel.schib.pmcw.dnv)
 796                         return -1;
 797                 console_devno = console_subchannel.schib.pmcw.dev;
 798         } else if (console_devno != -1) {
 799                 /* At least the console device number is known. */
 800                 for_each_subchannel(cio_test_for_console, NULL);
 801                 if (console_irq == -1)
 802                         return -1;
 803         } else {
 804                 /* unlike in 2.4, we cannot autoprobe here, since
 805                  * the channel subsystem is not fully initialized.
 806                  * With some luck, the HWC console can take over */
 807                 return -1;
 808         }
 809         return console_irq;
 810 }
 811
 812 struct subchannel *
 813 cio_probe_console(void)
 814 {
 815         int sch_no, ret;
 816         struct subchannel_id schid;
 817
 818         if (xchg(&console_subchannel_in_use, 1) != 0)
 819                 return ERR_PTR(-EBUSY);
 820         sch_no = cio_get_console_sch_no();
 821         if (sch_no == -1) {
 822                 console_subchannel_in_use = 0;
 823                 pr_warning("No CCW console was found\n");
 824                 return ERR_PTR(-ENODEV);
 825         }
 826         memset(&console_subchannel, 0, sizeof(struct subchannel));
 827         init_subchannel_id(&schid);
 828         schid.sch_no = sch_no;
 829         ret = cio_validate_subchannel(&console_subchannel, schid);
 830         if (ret) {
 831                 console_subchannel_in_use = 0;
 832                 return ERR_PTR(-ENODEV);
 833         }
 834
 835         /*
 836          * enable console I/O-interrupt subclass
 837          */
 838         isc_register(CONSOLE_ISC);
 839         console_subchannel.config.isc = CONSOLE_ISC;
 840         console_subchannel.config.intparm = (u32)(addr_t)&console_subchannel;
 841         ret = cio_commit_config(&console_subchannel);
 842         if (ret) {
 843                 isc_unregister(CONSOLE_ISC);
 844                 console_subchannel_in_use = 0;
 845                 return ERR_PTR(ret);
 846         }
 847         return &console_subchannel;
 848 }
 849
 850 void
 851 cio_release_console(void)
 852 {
 853         console_subchannel.config.intparm = 0;
 854         cio_commit_config(&console_subchannel);
 855         isc_unregister(CONSOLE_ISC);
 856         console_subchannel_in_use = 0;
 857 }
 858
 859 /* Bah... hack to catch console special sausages. */
 860 int
 861 cio_is_console(struct subchannel_id schid)
 862 {
 863         if (!console_subchannel_in_use)
 864                 return 0;
 865         return schid_equal(&schid, &console_subchannel.schid);
 866 }
 867
 868 struct subchannel *
 869 cio_get_console_subchannel(void)
 870 {
 871         if (!console_subchannel_in_use)
 872                 return NULL;
 873         return &console_subchannel;
 874 }
 875
 876 const char *cio_get_console_sch_name(struct subchannel_id schid)
 877 {
 878         snprintf(console_sch_name, 10, "0.%x.%04x", schid.ssid, schid.sch_no);
 879         return (const char *)console_sch_name;
 880 }
 881
 882 #endif
 883 static int
 884 __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
 885 {
 886         int retry, cc;
 887
 888         cc = 0;
 889         for (retry=0;retry<3;retry++) {
 890                 schib->pmcw.ena = 0;
 891                 cc = msch(schid, schib);
 892                 if (cc)
 893                         return (cc==3?-ENODEV:-EBUSY);
 894                 if (stsch(schid, schib) || !css_sch_is_valid(schib))
 895                         return -ENODEV;
 896                 if (!schib->pmcw.ena)
 897                         return 0;
 898         }
 899         return -EBUSY; /* uhm... */
 900 }
 901
 902 static int
 903 __clear_io_subchannel_easy(struct subchannel_id schid)
 904 {
 905         int retry;
 906
 907         if (csch(schid))
 908                 return -ENODEV;
 909         for (retry=0;retry<20;retry++) {
 910                 struct tpi_info ti;
 911
 912                 if (tpi(&ti)) {
 913                         tsch(ti.schid, (struct irb *)__LC_IRB);
 914                         if (schid_equal(&ti.schid, &schid))
 915                                 return 0;
 916                 }
 917                 udelay_simple(100);
 918         }
 919         return -EBUSY;
 920 }
 921
 922 static void __clear_chsc_subchannel_easy(void)
 923 {
 924         /* It seems we can only wait for a bit here :/ */
 925         udelay_simple(100);
 926 }
 927
 928 static int pgm_check_occured;
 929
 930 static void cio_reset_pgm_check_handler(void)
 931 {
 932         pgm_check_occured = 1;
 933 }
 934
 935 static int stsch_reset(struct subchannel_id schid, struct schib *addr)
 936 {
 937         int rc;
 938
 939         pgm_check_occured = 0;
 940         s390_base_pgm_handler_fn = cio_reset_pgm_check_handler;
 941         rc = stsch(schid, addr);
 942         s390_base_pgm_handler_fn = NULL;
 943
 944         /* The program check handler could have changed pgm_check_occured. */
 945         barrier();
 946
 947         if (pgm_check_occured)
 948                 return -EIO;
 949         else
 950                 return rc;
 951 }
 952
 953 static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
 954 {
 955         struct schib schib;
 956
 957         if (stsch_reset(schid, &schib))
 958                 return -ENXIO;
 959         if (!schib.pmcw.ena)
 960                 return 0;
 961         switch(__disable_subchannel_easy(schid, &schib)) {
 962         case 0:
 963         case -ENODEV:
 964                 break;
 965         default: /* -EBUSY */
 966                 switch (schib.pmcw.st) {
 967                 case SUBCHANNEL_TYPE_IO:
 968                         if (__clear_io_subchannel_easy(schid))
 969                                 goto out; /* give up... */
 970                         break;
 971                 case SUBCHANNEL_TYPE_CHSC:
 972                         __clear_chsc_subchannel_easy();
 973                         break;
 974                 default:
 975                         /* No default clear strategy */
 976                         break;
 977                 }
 978                 stsch(schid, &schib);
 979                 __disable_subchannel_easy(schid, &schib);
 980         }
 981 out:
 982         return 0;
 983 }
 984
 985 static atomic_t chpid_reset_count;
 986
 987 static void s390_reset_chpids_mcck_handler(void)
 988 {
 989         struct crw crw;
 990         struct mci *mci;
 991
 992         /* Check for pending channel report word. */
 993         mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
 994         if (!mci->cp)
 995                 return;
 996         /* Process channel report words. */
 997         while (stcrw(&crw) == 0) {
 998                 /* Check for responses to RCHP. */
 999                 if (crw.slct && crw.rsc == CRW_RSC_CPATH)
1000                         atomic_dec(&chpid_reset_count);
1001         }
1002 }
1003
1004 #define RCHP_TIMEOUT (30 * USEC_PER_SEC)
1005 static void css_reset(void)
1006 {
1007         int i, ret;
1008         unsigned long long timeout;
1009         struct chp_id chpid;
1010
1011         /* Reset subchannels. */
1012         for_each_subchannel(__shutdown_subchannel_easy,  NULL);
1013         /* Reset channel paths. */
1014         s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler;
1015         /* Enable channel report machine checks. */
1016         __ctl_set_bit(14, 28);
1017         /* Temporarily reenable machine checks. */
1018         local_mcck_enable();
1019         chp_id_init(&chpid);
1020         for (i = 0; i <= __MAX_CHPID; i++) {
1021                 chpid.id = i;
1022                 ret = rchp(chpid);
1023                 if ((ret == 0) || (ret == 2))
1024                         /*
1025                          * rchp either succeeded, or another rchp is already
1026                          * in progress. In either case, we'll get a crw.
1027                          */
1028                         atomic_inc(&chpid_reset_count);
1029         }
1030         /* Wait for machine check for all channel paths. */
1031         timeout = get_clock() + (RCHP_TIMEOUT << 12);
1032         while (atomic_read(&chpid_reset_count) != 0) {
1033                 if (get_clock() > timeout)
1034                         break;
1035                 cpu_relax();
1036         }
1037         /* Disable machine checks again. */
1038         local_mcck_disable();
1039         /* Disable channel report machine checks. */
1040         __ctl_clear_bit(14, 28);
1041         s390_base_mcck_handler_fn = NULL;
1042 }
1043
1044 static struct reset_call css_reset_call = {
1045         .fn = css_reset,
1046 };
1047
1048 static int __init init_css_reset_call(void)
1049 {
1050         atomic_set(&chpid_reset_count, 0);
1051         register_reset_call(&css_reset_call);
1052         return 0;
1053 }
1054
1055 arch_initcall(init_css_reset_call);
1056
1057 struct sch_match_id {
1058         struct subchannel_id schid;
1059         struct ccw_dev_id devid;
1060         int rc;
1061 };
1062
1063 static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
1064 {
1065         struct schib schib;
1066         struct sch_match_id *match_id = data;
1067
1068         if (stsch_reset(schid, &schib))
1069                 return -ENXIO;
1070         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
1071             (schib.pmcw.dev == match_id->devid.devno) &&
1072             (schid.ssid == match_id->devid.ssid)) {
1073                 match_id->schid = schid;
1074                 match_id->rc = 0;
1075                 return 1;
1076         }
1077         return 0;
1078 }
1079
1080 static int reipl_find_schid(struct ccw_dev_id *devid,
1081                             struct subchannel_id *schid)
1082 {
1083         struct sch_match_id match_id;
1084
1085         match_id.devid = *devid;
1086         match_id.rc = -ENODEV;
1087         for_each_subchannel(__reipl_subchannel_match, &match_id);
1088         if (match_id.rc == 0)
1089                 *schid = match_id.schid;
1090         return match_id.rc;
1091 }
1092
1093 extern void do_reipl_asm(__u32 schid);
1094
1095 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
1096 void reipl_ccw_dev(struct ccw_dev_id *devid)
1097 {
1098         struct subchannel_id schid;
1099
1100         s390_reset_system();
1101         if (reipl_find_schid(devid, &schid) != 0)
1102                 panic("IPL Device not found\n");
1103         do_reipl_asm(*((__u32*)&schid));
1104 }
1105
1106 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
1107 {
1108         struct subchannel_id schid;
1109         struct schib schib;
1110
1111         schid = *(struct subchannel_id *)__LC_SUBCHANNEL_ID;
1112         if (!schid.one)
1113                 return -ENODEV;
1114         if (stsch(schid, &schib))
1115                 return -ENODEV;
1116         if (schib.pmcw.st != SUBCHANNEL_TYPE_IO)
1117                 return -ENODEV;
1118         if (!schib.pmcw.dnv)
1119                 return -ENODEV;
1120         iplinfo->devno = schib.pmcw.dev;
1121         iplinfo->is_qdio = schib.pmcw.qf;
1122         return 0;
1123 }
1124
1125 /**
1126  * cio_tm_start_key - perform start function
1127  * @sch: subchannel on which to perform the start function
1128  * @tcw: transport-command word to be started
1129  * @lpm: mask of paths to use
1130  * @key: storage key to use for storage access
1131  *
1132  * Start the tcw on the given subchannel. Return zero on success, non-zero
1133  * otherwise.
1134  */
1135 int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
1136 {
1137         int cc;
1138         union orb *orb = &to_io_private(sch)->orb;
1139
1140         memset(orb, 0, sizeof(union orb));
1141         orb->tm.intparm = (u32) (addr_t) sch;
1142         orb->tm.key = key >> 4;
1143         orb->tm.b = 1;
1144         orb->tm.lpm = lpm ? lpm : sch->lpm;
1145         orb->tm.tcw = (u32) (addr_t) tcw;
1146         cc = ssch(sch->schid, orb);
1147         switch (cc) {
1148         case 0:
1149                 return 0;
1150         case 1:
1151         case 2:
1152                 return -EBUSY;
1153         default:
1154                 return cio_start_handle_notoper(sch, lpm);
1155         }
1156 }
1157
1158 /**
1159  * cio_tm_intrg - perform interrogate function
1160  * @sch - subchannel on which to perform the interrogate function
1161  *
1162  * If the specified subchannel is running in transport-mode, perform the
1163  * interrogate function. Return zero on success, non-zero otherwie.
1164  */
1165 int cio_tm_intrg(struct subchannel *sch)
1166 {
1167         int cc;
1168
1169         if (!to_io_private(sch)->orb.tm.b)
1170                 return -EINVAL;
1171         cc = xsch(sch->schid);
1172         switch (cc) {
1173         case 0:
1174         case 2:
1175                 return 0;
1176         case 1:
1177                 return -EBUSY;
1178         default:
1179                 return -ENODEV;
1180         }
1181 }