drivers/s390/cio/cio.c

   1 /*
   2  *   S/390 common I/O routines -- low level i/o calls
   3  *
   4  *    Copyright IBM Corp. 1999, 2008
   5  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
   6  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   7  *               Arnd Bergmann (arndb@de.ibm.com)
   8  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   9  */
  10
  11 #define KMSG_COMPONENT "cio"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/ftrace.h>
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/slab.h>
  18 #include <linux/device.h>
  19 #include <linux/kernel_stat.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/irq.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 <linux/sched/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 #include "trace.h"
  45
  46 debug_info_t *cio_debug_msg_id;
  47 debug_info_t *cio_debug_trace_id;
  48 debug_info_t *cio_debug_crw_id;
  49
  50 DEFINE_PER_CPU_ALIGNED(struct irb, cio_irb);
  51 EXPORT_PER_CPU_SYMBOL(cio_irb);
  52
  53 /*
  54  * Function: cio_debug_init
  55  * Initializes three debug logs for common I/O:
  56  * - cio_msg logs generic cio messages
  57  * - cio_trace logs the calling of different functions
  58  * - cio_crw logs machine check related cio messages
  59  */
  60 static int __init cio_debug_init(void)
  61 {
  62         cio_debug_msg_id = debug_register("cio_msg", 16, 1, 11 * sizeof(long));
  63         if (!cio_debug_msg_id)
  64                 goto out_unregister;
  65         debug_register_view(cio_debug_msg_id, &debug_sprintf_view);
  66         debug_set_level(cio_debug_msg_id, 2);
  67         cio_debug_trace_id = debug_register("cio_trace", 16, 1, 16);
  68         if (!cio_debug_trace_id)
  69                 goto out_unregister;
  70         debug_register_view(cio_debug_trace_id, &debug_hex_ascii_view);
  71         debug_set_level(cio_debug_trace_id, 2);
  72         cio_debug_crw_id = debug_register("cio_crw", 8, 1, 8 * sizeof(long));
  73         if (!cio_debug_crw_id)
  74                 goto out_unregister;
  75         debug_register_view(cio_debug_crw_id, &debug_sprintf_view);
  76         debug_set_level(cio_debug_crw_id, 4);
  77         return 0;
  78
  79 out_unregister:
  80         debug_unregister(cio_debug_msg_id);
  81         debug_unregister(cio_debug_trace_id);
  82         debug_unregister(cio_debug_crw_id);
  83         return -1;
  84 }
  85
  86 arch_initcall (cio_debug_init);
  87
  88 int cio_set_options(struct subchannel *sch, int flags)
  89 {
  90         struct io_subchannel_private *priv = to_io_private(sch);
  91
  92         priv->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
  93         priv->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
  94         priv->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
  95         return 0;
  96 }
  97
  98 static int
  99 cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
 100 {
 101         char dbf_text[15];
 102
 103         if (lpm != 0)
 104                 sch->lpm &= ~lpm;
 105         else
 106                 sch->lpm = 0;
 107
 108         CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
 109                       "subchannel 0.%x.%04x!\n", sch->schid.ssid,
 110                       sch->schid.sch_no);
 111
 112         if (cio_update_schib(sch))
 113                 return -ENODEV;
 114
 115         sprintf(dbf_text, "no%s", dev_name(&sch->dev));
 116         CIO_TRACE_EVENT(0, dbf_text);
 117         CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
 118
 119         return (sch->lpm ? -EACCES : -ENODEV);
 120 }
 121
 122 int
 123 cio_start_key (struct subchannel *sch,  /* subchannel structure */
 124                struct ccw1 * cpa,       /* logical channel prog addr */
 125                __u8 lpm,                /* logical path mask */
 126                __u8 key)                /* storage key */
 127 {
 128         struct io_subchannel_private *priv = to_io_private(sch);
 129         union orb *orb = &priv->orb;
 130         int ccode;
 131
 132         CIO_TRACE_EVENT(5, "stIO");
 133         CIO_TRACE_EVENT(5, dev_name(&sch->dev));
 134
 135         memset(orb, 0, sizeof(union orb));
 136         /* sch is always under 2G. */
 137         orb->cmd.intparm = (u32)(addr_t)sch;
 138         orb->cmd.fmt = 1;
 139
 140         orb->cmd.pfch = priv->options.prefetch == 0;
 141         orb->cmd.spnd = priv->options.suspend;
 142         orb->cmd.ssic = priv->options.suspend && priv->options.inter;
 143         orb->cmd.lpm = (lpm != 0) ? lpm : sch->lpm;
 144         /*
 145          * for 64 bit we always support 64 bit IDAWs with 4k page size only
 146          */
 147         orb->cmd.c64 = 1;
 148         orb->cmd.i2k = 0;
 149         orb->cmd.key = key >> 4;
 150         /* issue "Start Subchannel" */
 151         orb->cmd.cpa = (__u32) __pa(cpa);
 152         ccode = ssch(sch->schid, orb);
 153
 154         /* process condition code */
 155         CIO_HEX_EVENT(5, &ccode, sizeof(ccode));
 156
 157         switch (ccode) {
 158         case 0:
 159                 /*
 160                  * initialize device status information
 161                  */
 162                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
 163                 return 0;
 164         case 1:         /* status pending */
 165         case 2:         /* busy */
 166                 return -EBUSY;
 167         case 3:         /* device/path not operational */
 168                 return cio_start_handle_notoper(sch, lpm);
 169         default:
 170                 return ccode;
 171         }
 172 }
 173 EXPORT_SYMBOL_GPL(cio_start_key);
 174
 175 int
 176 cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
 177 {
 178         return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
 179 }
 180 EXPORT_SYMBOL_GPL(cio_start);
 181
 182 /*
 183  * resume suspended I/O operation
 184  */
 185 int
 186 cio_resume (struct subchannel *sch)
 187 {
 188         int ccode;
 189
 190         CIO_TRACE_EVENT(4, "resIO");
 191         CIO_TRACE_EVENT(4, dev_name(&sch->dev));
 192
 193         ccode = rsch (sch->schid);
 194
 195         CIO_HEX_EVENT(4, &ccode, sizeof(ccode));
 196
 197         switch (ccode) {
 198         case 0:
 199                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_RESUME_PEND;
 200                 return 0;
 201         case 1:
 202                 return -EBUSY;
 203         case 2:
 204                 return -EINVAL;
 205         default:
 206                 /*
 207                  * useless to wait for request completion
 208                  *  as device is no longer operational !
 209                  */
 210                 return -ENODEV;
 211         }
 212 }
 213 EXPORT_SYMBOL_GPL(cio_resume);
 214
 215 /*
 216  * halt I/O operation
 217  */
 218 int
 219 cio_halt(struct subchannel *sch)
 220 {
 221         int ccode;
 222
 223         if (!sch)
 224                 return -ENODEV;
 225
 226         CIO_TRACE_EVENT(2, "haltIO");
 227         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 228
 229         /*
 230          * Issue "Halt subchannel" and process condition code
 231          */
 232         ccode = hsch (sch->schid);
 233
 234         CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
 235
 236         switch (ccode) {
 237         case 0:
 238                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND;
 239                 return 0;
 240         case 1:         /* status pending */
 241         case 2:         /* busy */
 242                 return -EBUSY;
 243         default:                /* device not operational */
 244                 return -ENODEV;
 245         }
 246 }
 247 EXPORT_SYMBOL_GPL(cio_halt);
 248
 249 /*
 250  * Clear I/O operation
 251  */
 252 int
 253 cio_clear(struct subchannel *sch)
 254 {
 255         int ccode;
 256
 257         if (!sch)
 258                 return -ENODEV;
 259
 260         CIO_TRACE_EVENT(2, "clearIO");
 261         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 262
 263         /*
 264          * Issue "Clear subchannel" and process condition code
 265          */
 266         ccode = csch (sch->schid);
 267
 268         CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
 269
 270         switch (ccode) {
 271         case 0:
 272                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_CLEAR_PEND;
 273                 return 0;
 274         default:                /* device not operational */
 275                 return -ENODEV;
 276         }
 277 }
 278 EXPORT_SYMBOL_GPL(cio_clear);
 279
 280 /*
 281  * Function: cio_cancel
 282  * Issues a "Cancel Subchannel" on the specified subchannel
 283  * Note: We don't need any fancy intparms and flags here
 284  *       since xsch is executed synchronously.
 285  * Only for common I/O internal use as for now.
 286  */
 287 int
 288 cio_cancel (struct subchannel *sch)
 289 {
 290         int ccode;
 291
 292         if (!sch)
 293                 return -ENODEV;
 294
 295         CIO_TRACE_EVENT(2, "cancelIO");
 296         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 297
 298         ccode = xsch (sch->schid);
 299
 300         CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
 301
 302         switch (ccode) {
 303         case 0:         /* success */
 304                 /* Update information in scsw. */
 305                 if (cio_update_schib(sch))
 306                         return -ENODEV;
 307                 return 0;
 308         case 1:         /* status pending */
 309                 return -EBUSY;
 310         case 2:         /* not applicable */
 311                 return -EINVAL;
 312         default:        /* not oper */
 313                 return -ENODEV;
 314         }
 315 }
 316 EXPORT_SYMBOL_GPL(cio_cancel);
 317
 318 /**
 319  * cio_cancel_halt_clear - Cancel running I/O by performing cancel, halt
 320  * and clear ordinally if subchannel is valid.
 321  * @sch: subchannel on which to perform the cancel_halt_clear operation
 322  * @iretry: the number of the times remained to retry the next operation
 323  *
 324  * This should be called repeatedly since halt/clear are asynchronous
 325  * operations. We do one try with cio_cancel, three tries with cio_halt,
 326  * 255 tries with cio_clear. The caller should initialize @iretry with
 327  * the value 255 for its first call to this, and keep using the same
 328  * @iretry in the subsequent calls until it gets a non -EBUSY return.
 329  *
 330  * Returns 0 if device now idle, -ENODEV for device not operational,
 331  * -EBUSY if an interrupt is expected (either from halt/clear or from a
 332  * status pending), and -EIO if out of retries.
 333  */
 334 int cio_cancel_halt_clear(struct subchannel *sch, int *iretry)
 335 {
 336         int ret;
 337
 338         if (cio_update_schib(sch))
 339                 return -ENODEV;
 340         if (!sch->schib.pmcw.ena)
 341                 /* Not operational -> done. */
 342                 return 0;
 343         /* Stage 1: cancel io. */
 344         if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_HALT_PEND) &&
 345             !(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
 346                 if (!scsw_is_tm(&sch->schib.scsw)) {
 347                         ret = cio_cancel(sch);
 348                         if (ret != -EINVAL)
 349                                 return ret;
 350                 }
 351                 /*
 352                  * Cancel io unsuccessful or not applicable (transport mode).
 353                  * Continue with asynchronous instructions.
 354                  */
 355                 *iretry = 3;    /* 3 halt retries. */
 356         }
 357         /* Stage 2: halt io. */
 358         if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
 359                 if (*iretry) {
 360                         *iretry -= 1;
 361                         ret = cio_halt(sch);
 362                         if (ret != -EBUSY)
 363                                 return (ret == 0) ? -EBUSY : ret;
 364                 }
 365                 /* Halt io unsuccessful. */
 366                 *iretry = 255;  /* 255 clear retries. */
 367         }
 368         /* Stage 3: clear io. */
 369         if (*iretry) {
 370                 *iretry -= 1;
 371                 ret = cio_clear(sch);
 372                 return (ret == 0) ? -EBUSY : ret;
 373         }
 374         /* Function was unsuccessful */
 375         return -EIO;
 376 }
 377 EXPORT_SYMBOL_GPL(cio_cancel_halt_clear);
 378
 379 static void cio_apply_config(struct subchannel *sch, struct schib *schib)
 380 {
 381         schib->pmcw.intparm = sch->config.intparm;
 382         schib->pmcw.mbi = sch->config.mbi;
 383         schib->pmcw.isc = sch->config.isc;
 384         schib->pmcw.ena = sch->config.ena;
 385         schib->pmcw.mme = sch->config.mme;
 386         schib->pmcw.mp = sch->config.mp;
 387         schib->pmcw.csense = sch->config.csense;
 388         schib->pmcw.mbfc = sch->config.mbfc;
 389         if (sch->config.mbfc)
 390                 schib->mba = sch->config.mba;
 391 }
 392
 393 static int cio_check_config(struct subchannel *sch, struct schib *schib)
 394 {
 395         return (schib->pmcw.intparm == sch->config.intparm) &&
 396                 (schib->pmcw.mbi == sch->config.mbi) &&
 397                 (schib->pmcw.isc == sch->config.isc) &&
 398                 (schib->pmcw.ena == sch->config.ena) &&
 399                 (schib->pmcw.mme == sch->config.mme) &&
 400                 (schib->pmcw.mp == sch->config.mp) &&
 401                 (schib->pmcw.csense == sch->config.csense) &&
 402                 (schib->pmcw.mbfc == sch->config.mbfc) &&
 403                 (!sch->config.mbfc || (schib->mba == sch->config.mba));
 404 }
 405
 406 /*
 407  * cio_commit_config - apply configuration to the subchannel
 408  */
 409 int cio_commit_config(struct subchannel *sch)
 410 {
 411         int ccode, retry, ret = 0;
 412         struct schib schib;
 413         struct irb irb;
 414
 415         if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
 416                 return -ENODEV;
 417
 418         for (retry = 0; retry < 5; retry++) {
 419                 /* copy desired changes to local schib */
 420                 cio_apply_config(sch, &schib);
 421                 ccode = msch(sch->schid, &schib);
 422                 if (ccode < 0) /* -EIO if msch gets a program check. */
 423                         return ccode;
 424                 switch (ccode) {
 425                 case 0: /* successful */
 426                         if (stsch(sch->schid, &schib) ||
 427                             !css_sch_is_valid(&schib))
 428                                 return -ENODEV;
 429                         if (cio_check_config(sch, &schib)) {
 430                                 /* commit changes from local schib */
 431                                 memcpy(&sch->schib, &schib, sizeof(schib));
 432                                 return 0;
 433                         }
 434                         ret = -EAGAIN;
 435                         break;
 436                 case 1: /* status pending */
 437                         ret = -EBUSY;
 438                         if (tsch(sch->schid, &irb))
 439                                 return ret;
 440                         break;
 441                 case 2: /* busy */
 442                         udelay(100); /* allow for recovery */
 443                         ret = -EBUSY;
 444                         break;
 445                 case 3: /* not operational */
 446                         return -ENODEV;
 447                 }
 448         }
 449         return ret;
 450 }
 451 EXPORT_SYMBOL_GPL(cio_commit_config);
 452
 453 /**
 454  * cio_update_schib - Perform stsch and update schib if subchannel is valid.
 455  * @sch: subchannel on which to perform stsch
 456  * Return zero on success, -ENODEV otherwise.
 457  */
 458 int cio_update_schib(struct subchannel *sch)
 459 {
 460         struct schib schib;
 461
 462         if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
 463                 return -ENODEV;
 464
 465         memcpy(&sch->schib, &schib, sizeof(schib));
 466         return 0;
 467 }
 468 EXPORT_SYMBOL_GPL(cio_update_schib);
 469
 470 /**
 471  * cio_enable_subchannel - enable a subchannel.
 472  * @sch: subchannel to be enabled
 473  * @intparm: interruption parameter to set
 474  */
 475 int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
 476 {
 477         int ret;
 478
 479         CIO_TRACE_EVENT(2, "ensch");
 480         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 481
 482         if (sch_is_pseudo_sch(sch))
 483                 return -EINVAL;
 484         if (cio_update_schib(sch))
 485                 return -ENODEV;
 486
 487         sch->config.ena = 1;
 488         sch->config.isc = sch->isc;
 489         sch->config.intparm = intparm;
 490
 491         ret = cio_commit_config(sch);
 492         if (ret == -EIO) {
 493                 /*
 494                  * Got a program check in msch. Try without
 495                  * the concurrent sense bit the next time.
 496                  */
 497                 sch->config.csense = 0;
 498                 ret = cio_commit_config(sch);
 499         }
 500         CIO_HEX_EVENT(2, &ret, sizeof(ret));
 501         return ret;
 502 }
 503 EXPORT_SYMBOL_GPL(cio_enable_subchannel);
 504
 505 /**
 506  * cio_disable_subchannel - disable a subchannel.
 507  * @sch: subchannel to disable
 508  */
 509 int cio_disable_subchannel(struct subchannel *sch)
 510 {
 511         int ret;
 512
 513         CIO_TRACE_EVENT(2, "dissch");
 514         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 515
 516         if (sch_is_pseudo_sch(sch))
 517                 return 0;
 518         if (cio_update_schib(sch))
 519                 return -ENODEV;
 520
 521         sch->config.ena = 0;
 522         ret = cio_commit_config(sch);
 523
 524         CIO_HEX_EVENT(2, &ret, sizeof(ret));
 525         return ret;
 526 }
 527 EXPORT_SYMBOL_GPL(cio_disable_subchannel);
 528
 529 static int cio_check_devno_blacklisted(struct subchannel *sch)
 530 {
 531         if (is_blacklisted(sch->schid.ssid, sch->schib.pmcw.dev)) {
 532                 /*
 533                  * This device must not be known to Linux. So we simply
 534                  * say that there is no device and return ENODEV.
 535                  */
 536                 CIO_MSG_EVENT(6, "Blacklisted device detected "
 537                               "at devno %04X, subchannel set %x\n",
 538                               sch->schib.pmcw.dev, sch->schid.ssid);
 539                 return -ENODEV;
 540         }
 541         return 0;
 542 }
 543
 544 /**
 545  * cio_validate_subchannel - basic validation of subchannel
 546  * @sch: subchannel structure to be filled out
 547  * @schid: subchannel id
 548  *
 549  * Find out subchannel type and initialize struct subchannel.
 550  * Return codes:
 551  *   0 on success
 552  *   -ENXIO for non-defined subchannels
 553  *   -ENODEV for invalid subchannels or blacklisted devices
 554  *   -EIO for subchannels in an invalid subchannel set
 555  */
 556 int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
 557 {
 558         char dbf_txt[15];
 559         int ccode;
 560         int err;
 561
 562         sprintf(dbf_txt, "valsch%x", schid.sch_no);
 563         CIO_TRACE_EVENT(4, dbf_txt);
 564
 565         /*
 566          * The first subchannel that is not-operational (ccode==3)
 567          * indicates that there aren't any more devices available.
 568          * If stsch gets an exception, it means the current subchannel set
 569          * is not valid.
 570          */
 571         ccode = stsch(schid, &sch->schib);
 572         if (ccode) {
 573                 err = (ccode == 3) ? -ENXIO : ccode;
 574                 goto out;
 575         }
 576         sch->st = sch->schib.pmcw.st;
 577         sch->schid = schid;
 578
 579         switch (sch->st) {
 580         case SUBCHANNEL_TYPE_IO:
 581         case SUBCHANNEL_TYPE_MSG:
 582                 if (!css_sch_is_valid(&sch->schib))
 583                         err = -ENODEV;
 584                 else
 585                         err = cio_check_devno_blacklisted(sch);
 586                 break;
 587         default:
 588                 err = 0;
 589         }
 590         if (err)
 591                 goto out;
 592
 593         CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
 594                       sch->schid.ssid, sch->schid.sch_no, sch->st);
 595 out:
 596         return err;
 597 }
 598
 599 /*
 600  * do_cio_interrupt() handles all normal I/O device IRQ's
 601  */
 602 static irqreturn_t do_cio_interrupt(int irq, void *dummy)
 603 {
 604         struct tpi_info *tpi_info;
 605         struct subchannel *sch;
 606         struct irb *irb;
 607
 608         set_cpu_flag(CIF_NOHZ_DELAY);
 609         tpi_info = (struct tpi_info *) &get_irq_regs()->int_code;
 610         trace_s390_cio_interrupt(tpi_info);
 611         irb = this_cpu_ptr(&cio_irb);
 612         sch = (struct subchannel *)(unsigned long) tpi_info->intparm;
 613         if (!sch) {
 614                 /* Clear pending interrupt condition. */
 615                 inc_irq_stat(IRQIO_CIO);
 616                 tsch(tpi_info->schid, irb);
 617                 return IRQ_HANDLED;
 618         }
 619         spin_lock(sch->lock);
 620         /* Store interrupt response block to lowcore. */
 621         if (tsch(tpi_info->schid, irb) == 0) {
 622                 /* Keep subchannel information word up to date. */
 623                 memcpy (&sch->schib.scsw, &irb->scsw, sizeof (irb->scsw));
 624                 /* Call interrupt handler if there is one. */
 625                 if (sch->driver && sch->driver->irq)
 626                         sch->driver->irq(sch);
 627                 else
 628                         inc_irq_stat(IRQIO_CIO);
 629         } else
 630                 inc_irq_stat(IRQIO_CIO);
 631         spin_unlock(sch->lock);
 632
 633         return IRQ_HANDLED;
 634 }
 635
 636 static struct irqaction io_interrupt = {
 637         .name    = "IO",
 638         .handler = do_cio_interrupt,
 639 };
 640
 641 void __init init_cio_interrupts(void)
 642 {
 643         irq_set_chip_and_handler(IO_INTERRUPT,
 644                                  &dummy_irq_chip, handle_percpu_irq);
 645         setup_irq(IO_INTERRUPT, &io_interrupt);
 646 }
 647
 648 #ifdef CONFIG_CCW_CONSOLE
 649 static struct subchannel *console_sch;
 650 static struct lock_class_key console_sch_key;
 651
 652 /*
 653  * Use cio_tsch to update the subchannel status and call the interrupt handler
 654  * if status had been pending. Called with the subchannel's lock held.
 655  */
 656 void cio_tsch(struct subchannel *sch)
 657 {
 658         struct irb *irb;
 659         int irq_context;
 660
 661         irb = this_cpu_ptr(&cio_irb);
 662         /* Store interrupt response block to lowcore. */
 663         if (tsch(sch->schid, irb) != 0)
 664                 /* Not status pending or not operational. */
 665                 return;
 666         memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
 667         /* Call interrupt handler with updated status. */
 668         irq_context = in_interrupt();
 669         if (!irq_context) {
 670                 local_bh_disable();
 671                 irq_enter();
 672         }
 673         kstat_incr_irq_this_cpu(IO_INTERRUPT);
 674         if (sch->driver && sch->driver->irq)
 675                 sch->driver->irq(sch);
 676         else
 677                 inc_irq_stat(IRQIO_CIO);
 678         if (!irq_context) {
 679                 irq_exit();
 680                 _local_bh_enable();
 681         }
 682 }
 683
 684 static int cio_test_for_console(struct subchannel_id schid, void *data)
 685 {
 686         struct schib schib;
 687
 688         if (stsch(schid, &schib) != 0)
 689                 return -ENXIO;
 690         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
 691             (schib.pmcw.dev == console_devno)) {
 692                 console_irq = schid.sch_no;
 693                 return 1; /* found */
 694         }
 695         return 0;
 696 }
 697
 698 static int cio_get_console_sch_no(void)
 699 {
 700         struct subchannel_id schid;
 701         struct schib schib;
 702
 703         init_subchannel_id(&schid);
 704         if (console_irq != -1) {
 705                 /* VM provided us with the irq number of the console. */
 706                 schid.sch_no = console_irq;
 707                 if (stsch(schid, &schib) != 0 ||
 708                     (schib.pmcw.st != SUBCHANNEL_TYPE_IO) || !schib.pmcw.dnv)
 709                         return -1;
 710                 console_devno = schib.pmcw.dev;
 711         } else if (console_devno != -1) {
 712                 /* At least the console device number is known. */
 713                 for_each_subchannel(cio_test_for_console, NULL);
 714         }
 715         return console_irq;
 716 }
 717
 718 struct subchannel *cio_probe_console(void)
 719 {
 720         struct subchannel_id schid;
 721         struct subchannel *sch;
 722         int sch_no, ret;
 723
 724         sch_no = cio_get_console_sch_no();
 725         if (sch_no == -1) {
 726                 pr_warn("No CCW console was found\n");
 727                 return ERR_PTR(-ENODEV);
 728         }
 729         init_subchannel_id(&schid);
 730         schid.sch_no = sch_no;
 731         sch = css_alloc_subchannel(schid);
 732         if (IS_ERR(sch))
 733                 return sch;
 734
 735         lockdep_set_class(sch->lock, &console_sch_key);
 736         isc_register(CONSOLE_ISC);
 737         sch->config.isc = CONSOLE_ISC;
 738         sch->config.intparm = (u32)(addr_t)sch;
 739         ret = cio_commit_config(sch);
 740         if (ret) {
 741                 isc_unregister(CONSOLE_ISC);
 742                 put_device(&sch->dev);
 743                 return ERR_PTR(ret);
 744         }
 745         console_sch = sch;
 746         return sch;
 747 }
 748
 749 int cio_is_console(struct subchannel_id schid)
 750 {
 751         if (!console_sch)
 752                 return 0;
 753         return schid_equal(&schid, &console_sch->schid);
 754 }
 755
 756 void cio_register_early_subchannels(void)
 757 {
 758         int ret;
 759
 760         if (!console_sch)
 761                 return;
 762
 763         ret = css_register_subchannel(console_sch);
 764         if (ret)
 765                 put_device(&console_sch->dev);
 766 }
 767 #endif /* CONFIG_CCW_CONSOLE */
 768
 769 static int
 770 __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
 771 {
 772         int retry, cc;
 773
 774         cc = 0;
 775         for (retry=0;retry<3;retry++) {
 776                 schib->pmcw.ena = 0;
 777                 cc = msch(schid, schib);
 778                 if (cc)
 779                         return (cc==3?-ENODEV:-EBUSY);
 780                 if (stsch(schid, schib) || !css_sch_is_valid(schib))
 781                         return -ENODEV;
 782                 if (!schib->pmcw.ena)
 783                         return 0;
 784         }
 785         return -EBUSY; /* uhm... */
 786 }
 787
 788 static int
 789 __clear_io_subchannel_easy(struct subchannel_id schid)
 790 {
 791         int retry;
 792
 793         if (csch(schid))
 794                 return -ENODEV;
 795         for (retry=0;retry<20;retry++) {
 796                 struct tpi_info ti;
 797
 798                 if (tpi(&ti)) {
 799                         tsch(ti.schid, this_cpu_ptr(&cio_irb));
 800                         if (schid_equal(&ti.schid, &schid))
 801                                 return 0;
 802                 }
 803                 udelay_simple(100);
 804         }
 805         return -EBUSY;
 806 }
 807
 808 static void __clear_chsc_subchannel_easy(void)
 809 {
 810         /* It seems we can only wait for a bit here :/ */
 811         udelay_simple(100);
 812 }
 813
 814 static int pgm_check_occured;
 815
 816 static void cio_reset_pgm_check_handler(void)
 817 {
 818         pgm_check_occured = 1;
 819 }
 820
 821 static int stsch_reset(struct subchannel_id schid, struct schib *addr)
 822 {
 823         int rc;
 824
 825         pgm_check_occured = 0;
 826         s390_base_pgm_handler_fn = cio_reset_pgm_check_handler;
 827         rc = stsch(schid, addr);
 828         s390_base_pgm_handler_fn = NULL;
 829
 830         /* The program check handler could have changed pgm_check_occured. */
 831         barrier();
 832
 833         if (pgm_check_occured)
 834                 return -EIO;
 835         else
 836                 return rc;
 837 }
 838
 839 static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
 840 {
 841         struct schib schib;
 842
 843         if (stsch_reset(schid, &schib))
 844                 return -ENXIO;
 845         if (!schib.pmcw.ena)
 846                 return 0;
 847         switch(__disable_subchannel_easy(schid, &schib)) {
 848         case 0:
 849         case -ENODEV:
 850                 break;
 851         default: /* -EBUSY */
 852                 switch (schib.pmcw.st) {
 853                 case SUBCHANNEL_TYPE_IO:
 854                         if (__clear_io_subchannel_easy(schid))
 855                                 goto out; /* give up... */
 856                         break;
 857                 case SUBCHANNEL_TYPE_CHSC:
 858                         __clear_chsc_subchannel_easy();
 859                         break;
 860                 default:
 861                         /* No default clear strategy */
 862                         break;
 863                 }
 864                 stsch(schid, &schib);
 865                 __disable_subchannel_easy(schid, &schib);
 866         }
 867 out:
 868         return 0;
 869 }
 870
 871 static atomic_t chpid_reset_count;
 872
 873 static void s390_reset_chpids_mcck_handler(void)
 874 {
 875         struct crw crw;
 876         union mci mci;
 877
 878         /* Check for pending channel report word. */
 879         mci.val = S390_lowcore.mcck_interruption_code;
 880         if (!mci.cp)
 881                 return;
 882         /* Process channel report words. */
 883         while (stcrw(&crw) == 0) {
 884                 /* Check for responses to RCHP. */
 885                 if (crw.slct && crw.rsc == CRW_RSC_CPATH)
 886                         atomic_dec(&chpid_reset_count);
 887         }
 888 }
 889
 890 #define RCHP_TIMEOUT (30 * USEC_PER_SEC)
 891 static void css_reset(void)
 892 {
 893         int i, ret;
 894         unsigned long long timeout;
 895         struct chp_id chpid;
 896
 897         /* Reset subchannels. */
 898         for_each_subchannel(__shutdown_subchannel_easy,  NULL);
 899         /* Reset channel paths. */
 900         s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler;
 901         /* Enable channel report machine checks. */
 902         __ctl_set_bit(14, 28);
 903         /* Temporarily reenable machine checks. */
 904         local_mcck_enable();
 905         chp_id_init(&chpid);
 906         for (i = 0; i <= __MAX_CHPID; i++) {
 907                 chpid.id = i;
 908                 ret = rchp(chpid);
 909                 if ((ret == 0) || (ret == 2))
 910                         /*
 911                          * rchp either succeeded, or another rchp is already
 912                          * in progress. In either case, we'll get a crw.
 913                          */
 914                         atomic_inc(&chpid_reset_count);
 915         }
 916         /* Wait for machine check for all channel paths. */
 917         timeout = get_tod_clock_fast() + (RCHP_TIMEOUT << 12);
 918         while (atomic_read(&chpid_reset_count) != 0) {
 919                 if (get_tod_clock_fast() > timeout)
 920                         break;
 921                 cpu_relax();
 922         }
 923         /* Disable machine checks again. */
 924         local_mcck_disable();
 925         /* Disable channel report machine checks. */
 926         __ctl_clear_bit(14, 28);
 927         s390_base_mcck_handler_fn = NULL;
 928 }
 929
 930 static struct reset_call css_reset_call = {
 931         .fn = css_reset,
 932 };
 933
 934 static int __init init_css_reset_call(void)
 935 {
 936         atomic_set(&chpid_reset_count, 0);
 937         register_reset_call(&css_reset_call);
 938         return 0;
 939 }
 940
 941 arch_initcall(init_css_reset_call);
 942
 943 struct sch_match_id {
 944         struct subchannel_id schid;
 945         struct ccw_dev_id devid;
 946         int rc;
 947 };
 948
 949 static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
 950 {
 951         struct schib schib;
 952         struct sch_match_id *match_id = data;
 953
 954         if (stsch_reset(schid, &schib))
 955                 return -ENXIO;
 956         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
 957             (schib.pmcw.dev == match_id->devid.devno) &&
 958             (schid.ssid == match_id->devid.ssid)) {
 959                 match_id->schid = schid;
 960                 match_id->rc = 0;
 961                 return 1;
 962         }
 963         return 0;
 964 }
 965
 966 static int reipl_find_schid(struct ccw_dev_id *devid,
 967                             struct subchannel_id *schid)
 968 {
 969         struct sch_match_id match_id;
 970
 971         match_id.devid = *devid;
 972         match_id.rc = -ENODEV;
 973         for_each_subchannel(__reipl_subchannel_match, &match_id);
 974         if (match_id.rc == 0)
 975                 *schid = match_id.schid;
 976         return match_id.rc;
 977 }
 978
 979 extern void do_reipl_asm(__u32 schid);
 980
 981 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
 982 void reipl_ccw_dev(struct ccw_dev_id *devid)
 983 {
 984         struct subchannel_id uninitialized_var(schid);
 985
 986         s390_reset_system();
 987         if (reipl_find_schid(devid, &schid) != 0)
 988                 panic("IPL Device not found\n");
 989         do_reipl_asm(*((__u32*)&schid));
 990 }
 991
 992 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
 993 {
 994         static struct chsc_sda_area sda_area __initdata;
 995         struct subchannel_id schid;
 996         struct schib schib;
 997
 998         schid = *(struct subchannel_id *)&S390_lowcore.subchannel_id;
 999         if (!schid.one)
1000                 return -ENODEV;
1001
1002         if (schid.ssid) {
1003                 /*
1004                  * Firmware should have already enabled MSS but whoever started
1005                  * the kernel might have initiated a channel subsystem reset.
1006                  * Ensure that MSS is enabled.
1007                  */
1008                 memset(&sda_area, 0, sizeof(sda_area));
1009                 if (__chsc_enable_facility(&sda_area, CHSC_SDA_OC_MSS))
1010                         return -ENODEV;
1011         }
1012         if (stsch(schid, &schib))
1013                 return -ENODEV;
1014         if (schib.pmcw.st != SUBCHANNEL_TYPE_IO)
1015                 return -ENODEV;
1016         if (!schib.pmcw.dnv)
1017                 return -ENODEV;
1018
1019         iplinfo->ssid = schid.ssid;
1020         iplinfo->devno = schib.pmcw.dev;
1021         iplinfo->is_qdio = schib.pmcw.qf;
1022         return 0;
1023 }
1024
1025 /**
1026  * cio_tm_start_key - perform start function
1027  * @sch: subchannel on which to perform the start function
1028  * @tcw: transport-command word to be started
1029  * @lpm: mask of paths to use
1030  * @key: storage key to use for storage access
1031  *
1032  * Start the tcw on the given subchannel. Return zero on success, non-zero
1033  * otherwise.
1034  */
1035 int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
1036 {
1037         int cc;
1038         union orb *orb = &to_io_private(sch)->orb;
1039
1040         memset(orb, 0, sizeof(union orb));
1041         orb->tm.intparm = (u32) (addr_t) sch;
1042         orb->tm.key = key >> 4;
1043         orb->tm.b = 1;
1044         orb->tm.lpm = lpm ? lpm : sch->lpm;
1045         orb->tm.tcw = (u32) (addr_t) tcw;
1046         cc = ssch(sch->schid, orb);
1047         switch (cc) {
1048         case 0:
1049                 return 0;
1050         case 1:
1051         case 2:
1052                 return -EBUSY;
1053         default:
1054                 return cio_start_handle_notoper(sch, lpm);
1055         }
1056 }
1057 EXPORT_SYMBOL_GPL(cio_tm_start_key);
1058
1059 /**
1060  * cio_tm_intrg - perform interrogate function
1061  * @sch - subchannel on which to perform the interrogate function
1062  *
1063  * If the specified subchannel is running in transport-mode, perform the
1064  * interrogate function. Return zero on success, non-zero otherwie.
1065  */
1066 int cio_tm_intrg(struct subchannel *sch)
1067 {
1068         int cc;
1069
1070         if (!to_io_private(sch)->orb.tm.b)
1071                 return -EINVAL;
1072         cc = xsch(sch->schid);
1073         switch (cc) {
1074         case 0:
1075         case 2:
1076                 return 0;
1077         case 1:
1078                 return -EBUSY;
1079         default:
1080                 return -ENODEV;
1081         }
1082 }
1083 EXPORT_SYMBOL_GPL(cio_tm_intrg);