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/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 DEFINE_PER_CPU_ALIGNED(struct irb, cio_irb);
  50 EXPORT_PER_CPU_SYMBOL(cio_irb);
  51
  52 /*
  53  * Function: cio_debug_init
  54  * Initializes three debug logs for common I/O:
  55  * - cio_msg logs generic cio messages
  56  * - cio_trace logs the calling of different functions
  57  * - cio_crw logs machine check related cio messages
  58  */
  59 static int __init cio_debug_init(void)
  60 {
  61         cio_debug_msg_id = debug_register("cio_msg", 16, 1, 11 * sizeof(long));
  62         if (!cio_debug_msg_id)
  63                 goto out_unregister;
  64         debug_register_view(cio_debug_msg_id, &debug_sprintf_view);
  65         debug_set_level(cio_debug_msg_id, 2);
  66         cio_debug_trace_id = debug_register("cio_trace", 16, 1, 16);
  67         if (!cio_debug_trace_id)
  68                 goto out_unregister;
  69         debug_register_view(cio_debug_trace_id, &debug_hex_ascii_view);
  70         debug_set_level(cio_debug_trace_id, 2);
  71         cio_debug_crw_id = debug_register("cio_crw", 8, 1, 8 * sizeof(long));
  72         if (!cio_debug_crw_id)
  73                 goto out_unregister;
  74         debug_register_view(cio_debug_crw_id, &debug_sprintf_view);
  75         debug_set_level(cio_debug_crw_id, 4);
  76         return 0;
  77
  78 out_unregister:
  79         if (cio_debug_msg_id)
  80                 debug_unregister(cio_debug_msg_id);
  81         if (cio_debug_trace_id)
  82                 debug_unregister(cio_debug_trace_id);
  83         if (cio_debug_crw_id)
  84                 debug_unregister(cio_debug_crw_id);
  85         return -1;
  86 }
  87
  88 arch_initcall (cio_debug_init);
  89
  90 int cio_set_options(struct subchannel *sch, int flags)
  91 {
  92         struct io_subchannel_private *priv = to_io_private(sch);
  93
  94         priv->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
  95         priv->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
  96         priv->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
  97         return 0;
  98 }
  99
 100 static int
 101 cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
 102 {
 103         char dbf_text[15];
 104
 105         if (lpm != 0)
 106                 sch->lpm &= ~lpm;
 107         else
 108                 sch->lpm = 0;
 109
 110         CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
 111                       "subchannel 0.%x.%04x!\n", sch->schid.ssid,
 112                       sch->schid.sch_no);
 113
 114         if (cio_update_schib(sch))
 115                 return -ENODEV;
 116
 117         sprintf(dbf_text, "no%s", dev_name(&sch->dev));
 118         CIO_TRACE_EVENT(0, dbf_text);
 119         CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
 120
 121         return (sch->lpm ? -EACCES : -ENODEV);
 122 }
 123
 124 int
 125 cio_start_key (struct subchannel *sch,  /* subchannel structure */
 126                struct ccw1 * cpa,       /* logical channel prog addr */
 127                __u8 lpm,                /* logical path mask */
 128                __u8 key)                /* storage key */
 129 {
 130         struct io_subchannel_private *priv = to_io_private(sch);
 131         union orb *orb = &priv->orb;
 132         int ccode;
 133
 134         CIO_TRACE_EVENT(5, "stIO");
 135         CIO_TRACE_EVENT(5, dev_name(&sch->dev));
 136
 137         memset(orb, 0, sizeof(union orb));
 138         /* sch is always under 2G. */
 139         orb->cmd.intparm = (u32)(addr_t)sch;
 140         orb->cmd.fmt = 1;
 141
 142         orb->cmd.pfch = priv->options.prefetch == 0;
 143         orb->cmd.spnd = priv->options.suspend;
 144         orb->cmd.ssic = priv->options.suspend && priv->options.inter;
 145         orb->cmd.lpm = (lpm != 0) ? lpm : sch->lpm;
 146 #ifdef CONFIG_64BIT
 147         /*
 148          * for 64 bit we always support 64 bit IDAWs with 4k page size only
 149          */
 150         orb->cmd.c64 = 1;
 151         orb->cmd.i2k = 0;
 152 #endif
 153         orb->cmd.key = key >> 4;
 154         /* issue "Start Subchannel" */
 155         orb->cmd.cpa = (__u32) __pa(cpa);
 156         ccode = ssch(sch->schid, orb);
 157
 158         /* process condition code */
 159         CIO_HEX_EVENT(5, &ccode, sizeof(ccode));
 160
 161         switch (ccode) {
 162         case 0:
 163                 /*
 164                  * initialize device status information
 165                  */
 166                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
 167                 return 0;
 168         case 1:         /* status pending */
 169         case 2:         /* busy */
 170                 return -EBUSY;
 171         case 3:         /* device/path not operational */
 172                 return cio_start_handle_notoper(sch, lpm);
 173         default:
 174                 return ccode;
 175         }
 176 }
 177
 178 int
 179 cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
 180 {
 181         return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
 182 }
 183
 184 /*
 185  * resume suspended I/O operation
 186  */
 187 int
 188 cio_resume (struct subchannel *sch)
 189 {
 190         int ccode;
 191
 192         CIO_TRACE_EVENT(4, "resIO");
 193         CIO_TRACE_EVENT(4, dev_name(&sch->dev));
 194
 195         ccode = rsch (sch->schid);
 196
 197         CIO_HEX_EVENT(4, &ccode, sizeof(ccode));
 198
 199         switch (ccode) {
 200         case 0:
 201                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_RESUME_PEND;
 202                 return 0;
 203         case 1:
 204                 return -EBUSY;
 205         case 2:
 206                 return -EINVAL;
 207         default:
 208                 /*
 209                  * useless to wait for request completion
 210                  *  as device is no longer operational !
 211                  */
 212                 return -ENODEV;
 213         }
 214 }
 215
 216 /*
 217  * halt I/O operation
 218  */
 219 int
 220 cio_halt(struct subchannel *sch)
 221 {
 222         int ccode;
 223
 224         if (!sch)
 225                 return -ENODEV;
 226
 227         CIO_TRACE_EVENT(2, "haltIO");
 228         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 229
 230         /*
 231          * Issue "Halt subchannel" and process condition code
 232          */
 233         ccode = hsch (sch->schid);
 234
 235         CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
 236
 237         switch (ccode) {
 238         case 0:
 239                 sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND;
 240                 return 0;
 241         case 1:         /* status pending */
 242         case 2:         /* busy */
 243                 return -EBUSY;
 244         default:                /* device not operational */
 245                 return -ENODEV;
 246         }
 247 }
 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
 279 /*
 280  * Function: cio_cancel
 281  * Issues a "Cancel Subchannel" on the specified subchannel
 282  * Note: We don't need any fancy intparms and flags here
 283  *       since xsch is executed synchronously.
 284  * Only for common I/O internal use as for now.
 285  */
 286 int
 287 cio_cancel (struct subchannel *sch)
 288 {
 289         int ccode;
 290
 291         if (!sch)
 292                 return -ENODEV;
 293
 294         CIO_TRACE_EVENT(2, "cancelIO");
 295         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 296
 297         ccode = xsch (sch->schid);
 298
 299         CIO_HEX_EVENT(2, &ccode, sizeof(ccode));
 300
 301         switch (ccode) {
 302         case 0:         /* success */
 303                 /* Update information in scsw. */
 304                 if (cio_update_schib(sch))
 305                         return -ENODEV;
 306                 return 0;
 307         case 1:         /* status pending */
 308                 return -EBUSY;
 309         case 2:         /* not applicable */
 310                 return -EINVAL;
 311         default:        /* not oper */
 312                 return -ENODEV;
 313         }
 314 }
 315
 316
 317 static void cio_apply_config(struct subchannel *sch, struct schib *schib)
 318 {
 319         schib->pmcw.intparm = sch->config.intparm;
 320         schib->pmcw.mbi = sch->config.mbi;
 321         schib->pmcw.isc = sch->config.isc;
 322         schib->pmcw.ena = sch->config.ena;
 323         schib->pmcw.mme = sch->config.mme;
 324         schib->pmcw.mp = sch->config.mp;
 325         schib->pmcw.csense = sch->config.csense;
 326         schib->pmcw.mbfc = sch->config.mbfc;
 327         if (sch->config.mbfc)
 328                 schib->mba = sch->config.mba;
 329 }
 330
 331 static int cio_check_config(struct subchannel *sch, struct schib *schib)
 332 {
 333         return (schib->pmcw.intparm == sch->config.intparm) &&
 334                 (schib->pmcw.mbi == sch->config.mbi) &&
 335                 (schib->pmcw.isc == sch->config.isc) &&
 336                 (schib->pmcw.ena == sch->config.ena) &&
 337                 (schib->pmcw.mme == sch->config.mme) &&
 338                 (schib->pmcw.mp == sch->config.mp) &&
 339                 (schib->pmcw.csense == sch->config.csense) &&
 340                 (schib->pmcw.mbfc == sch->config.mbfc) &&
 341                 (!sch->config.mbfc || (schib->mba == sch->config.mba));
 342 }
 343
 344 /*
 345  * cio_commit_config - apply configuration to the subchannel
 346  */
 347 int cio_commit_config(struct subchannel *sch)
 348 {
 349         int ccode, retry, ret = 0;
 350         struct schib schib;
 351         struct irb irb;
 352
 353         if (stsch_err(sch->schid, &schib) || !css_sch_is_valid(&schib))
 354                 return -ENODEV;
 355
 356         for (retry = 0; retry < 5; retry++) {
 357                 /* copy desired changes to local schib */
 358                 cio_apply_config(sch, &schib);
 359                 ccode = msch_err(sch->schid, &schib);
 360                 if (ccode < 0) /* -EIO if msch gets a program check. */
 361                         return ccode;
 362                 switch (ccode) {
 363                 case 0: /* successful */
 364                         if (stsch_err(sch->schid, &schib) ||
 365                             !css_sch_is_valid(&schib))
 366                                 return -ENODEV;
 367                         if (cio_check_config(sch, &schib)) {
 368                                 /* commit changes from local schib */
 369                                 memcpy(&sch->schib, &schib, sizeof(schib));
 370                                 return 0;
 371                         }
 372                         ret = -EAGAIN;
 373                         break;
 374                 case 1: /* status pending */
 375                         ret = -EBUSY;
 376                         if (tsch(sch->schid, &irb))
 377                                 return ret;
 378                         break;
 379                 case 2: /* busy */
 380                         udelay(100); /* allow for recovery */
 381                         ret = -EBUSY;
 382                         break;
 383                 case 3: /* not operational */
 384                         return -ENODEV;
 385                 }
 386         }
 387         return ret;
 388 }
 389
 390 /**
 391  * cio_update_schib - Perform stsch and update schib if subchannel is valid.
 392  * @sch: subchannel on which to perform stsch
 393  * Return zero on success, -ENODEV otherwise.
 394  */
 395 int cio_update_schib(struct subchannel *sch)
 396 {
 397         struct schib schib;
 398
 399         if (stsch_err(sch->schid, &schib) || !css_sch_is_valid(&schib))
 400                 return -ENODEV;
 401
 402         memcpy(&sch->schib, &schib, sizeof(schib));
 403         return 0;
 404 }
 405 EXPORT_SYMBOL_GPL(cio_update_schib);
 406
 407 /**
 408  * cio_enable_subchannel - enable a subchannel.
 409  * @sch: subchannel to be enabled
 410  * @intparm: interruption parameter to set
 411  */
 412 int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
 413 {
 414         int ret;
 415
 416         CIO_TRACE_EVENT(2, "ensch");
 417         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 418
 419         if (sch_is_pseudo_sch(sch))
 420                 return -EINVAL;
 421         if (cio_update_schib(sch))
 422                 return -ENODEV;
 423
 424         sch->config.ena = 1;
 425         sch->config.isc = sch->isc;
 426         sch->config.intparm = intparm;
 427
 428         ret = cio_commit_config(sch);
 429         if (ret == -EIO) {
 430                 /*
 431                  * Got a program check in msch. Try without
 432                  * the concurrent sense bit the next time.
 433                  */
 434                 sch->config.csense = 0;
 435                 ret = cio_commit_config(sch);
 436         }
 437         CIO_HEX_EVENT(2, &ret, sizeof(ret));
 438         return ret;
 439 }
 440 EXPORT_SYMBOL_GPL(cio_enable_subchannel);
 441
 442 /**
 443  * cio_disable_subchannel - disable a subchannel.
 444  * @sch: subchannel to disable
 445  */
 446 int cio_disable_subchannel(struct subchannel *sch)
 447 {
 448         int ret;
 449
 450         CIO_TRACE_EVENT(2, "dissch");
 451         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
 452
 453         if (sch_is_pseudo_sch(sch))
 454                 return 0;
 455         if (cio_update_schib(sch))
 456                 return -ENODEV;
 457
 458         sch->config.ena = 0;
 459         ret = cio_commit_config(sch);
 460
 461         CIO_HEX_EVENT(2, &ret, sizeof(ret));
 462         return ret;
 463 }
 464 EXPORT_SYMBOL_GPL(cio_disable_subchannel);
 465
 466 static int cio_check_devno_blacklisted(struct subchannel *sch)
 467 {
 468         if (is_blacklisted(sch->schid.ssid, sch->schib.pmcw.dev)) {
 469                 /*
 470                  * This device must not be known to Linux. So we simply
 471                  * say that there is no device and return ENODEV.
 472                  */
 473                 CIO_MSG_EVENT(6, "Blacklisted device detected "
 474                               "at devno %04X, subchannel set %x\n",
 475                               sch->schib.pmcw.dev, sch->schid.ssid);
 476                 return -ENODEV;
 477         }
 478         return 0;
 479 }
 480
 481 static int cio_validate_io_subchannel(struct subchannel *sch)
 482 {
 483         /* Initialization for io subchannels. */
 484         if (!css_sch_is_valid(&sch->schib))
 485                 return -ENODEV;
 486
 487         /* Devno is valid. */
 488         return cio_check_devno_blacklisted(sch);
 489 }
 490
 491 static int cio_validate_msg_subchannel(struct subchannel *sch)
 492 {
 493         /* Initialization for message subchannels. */
 494         if (!css_sch_is_valid(&sch->schib))
 495                 return -ENODEV;
 496
 497         /* Devno is valid. */
 498         return cio_check_devno_blacklisted(sch);
 499 }
 500
 501 /**
 502  * cio_validate_subchannel - basic validation of subchannel
 503  * @sch: subchannel structure to be filled out
 504  * @schid: subchannel id
 505  *
 506  * Find out subchannel type and initialize struct subchannel.
 507  * Return codes:
 508  *   0 on success
 509  *   -ENXIO for non-defined subchannels
 510  *   -ENODEV for invalid subchannels or blacklisted devices
 511  *   -EIO for subchannels in an invalid subchannel set
 512  */
 513 int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
 514 {
 515         char dbf_txt[15];
 516         int ccode;
 517         int err;
 518
 519         sprintf(dbf_txt, "valsch%x", schid.sch_no);
 520         CIO_TRACE_EVENT(4, dbf_txt);
 521
 522         /*
 523          * The first subchannel that is not-operational (ccode==3)
 524          * indicates that there aren't any more devices available.
 525          * If stsch gets an exception, it means the current subchannel set
 526          * is not valid.
 527          */
 528         ccode = stsch_err(schid, &sch->schib);
 529         if (ccode) {
 530                 err = (ccode == 3) ? -ENXIO : ccode;
 531                 goto out;
 532         }
 533         sch->st = sch->schib.pmcw.st;
 534         sch->schid = schid;
 535
 536         switch (sch->st) {
 537         case SUBCHANNEL_TYPE_IO:
 538                 err = cio_validate_io_subchannel(sch);
 539                 break;
 540         case SUBCHANNEL_TYPE_MSG:
 541                 err = cio_validate_msg_subchannel(sch);
 542                 break;
 543         default:
 544                 err = 0;
 545         }
 546         if (err)
 547                 goto out;
 548
 549         CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
 550                       sch->schid.ssid, sch->schid.sch_no, sch->st);
 551 out:
 552         return err;
 553 }
 554
 555 /*
 556  * do_cio_interrupt() handles all normal I/O device IRQ's
 557  */
 558 static irqreturn_t do_cio_interrupt(int irq, void *dummy)
 559 {
 560         struct tpi_info *tpi_info;
 561         struct subchannel *sch;
 562         struct irb *irb;
 563
 564         __this_cpu_write(s390_idle.nohz_delay, 1);
 565         tpi_info = (struct tpi_info *) &get_irq_regs()->int_code;
 566         irb = &__get_cpu_var(cio_irb);
 567         sch = (struct subchannel *)(unsigned long) tpi_info->intparm;
 568         if (!sch) {
 569                 /* Clear pending interrupt condition. */
 570                 inc_irq_stat(IRQIO_CIO);
 571                 tsch(tpi_info->schid, irb);
 572                 return IRQ_HANDLED;
 573         }
 574         spin_lock(sch->lock);
 575         /* Store interrupt response block to lowcore. */
 576         if (tsch(tpi_info->schid, irb) == 0) {
 577                 /* Keep subchannel information word up to date. */
 578                 memcpy (&sch->schib.scsw, &irb->scsw, sizeof (irb->scsw));
 579                 /* Call interrupt handler if there is one. */
 580                 if (sch->driver && sch->driver->irq)
 581                         sch->driver->irq(sch);
 582                 else
 583                         inc_irq_stat(IRQIO_CIO);
 584         } else
 585                 inc_irq_stat(IRQIO_CIO);
 586         spin_unlock(sch->lock);
 587
 588         return IRQ_HANDLED;
 589 }
 590
 591 static struct irqaction io_interrupt = {
 592         .name    = "IO",
 593         .handler = do_cio_interrupt,
 594 };
 595
 596 void __init init_cio_interrupts(void)
 597 {
 598         irq_set_chip_and_handler(IO_INTERRUPT,
 599                                  &dummy_irq_chip, handle_percpu_irq);
 600         setup_irq(IO_INTERRUPT, &io_interrupt);
 601 }
 602
 603 #ifdef CONFIG_CCW_CONSOLE
 604 static struct subchannel *console_sch;
 605 static struct lock_class_key console_sch_key;
 606
 607 /*
 608  * Use cio_tsch to update the subchannel status and call the interrupt handler
 609  * if status had been pending. Called with the subchannel's lock held.
 610  */
 611 void cio_tsch(struct subchannel *sch)
 612 {
 613         struct irb *irb;
 614         int irq_context;
 615
 616         irb = &__get_cpu_var(cio_irb);
 617         /* Store interrupt response block to lowcore. */
 618         if (tsch(sch->schid, irb) != 0)
 619                 /* Not status pending or not operational. */
 620                 return;
 621         memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw));
 622         /* Call interrupt handler with updated status. */
 623         irq_context = in_interrupt();
 624         if (!irq_context) {
 625                 local_bh_disable();
 626                 irq_enter();
 627         }
 628         kstat_incr_irq_this_cpu(IO_INTERRUPT);
 629         if (sch->driver && sch->driver->irq)
 630                 sch->driver->irq(sch);
 631         else
 632                 inc_irq_stat(IRQIO_CIO);
 633         if (!irq_context) {
 634                 irq_exit();
 635                 _local_bh_enable();
 636         }
 637 }
 638
 639 static int cio_test_for_console(struct subchannel_id schid, void *data)
 640 {
 641         struct schib schib;
 642
 643         if (stsch_err(schid, &schib) != 0)
 644                 return -ENXIO;
 645         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
 646             (schib.pmcw.dev == console_devno)) {
 647                 console_irq = schid.sch_no;
 648                 return 1; /* found */
 649         }
 650         return 0;
 651 }
 652
 653 static int cio_get_console_sch_no(void)
 654 {
 655         struct subchannel_id schid;
 656         struct schib schib;
 657
 658         init_subchannel_id(&schid);
 659         if (console_irq != -1) {
 660                 /* VM provided us with the irq number of the console. */
 661                 schid.sch_no = console_irq;
 662                 if (stsch_err(schid, &schib) != 0 ||
 663                     (schib.pmcw.st != SUBCHANNEL_TYPE_IO) || !schib.pmcw.dnv)
 664                         return -1;
 665                 console_devno = schib.pmcw.dev;
 666         } else if (console_devno != -1) {
 667                 /* At least the console device number is known. */
 668                 for_each_subchannel(cio_test_for_console, NULL);
 669         }
 670         return console_irq;
 671 }
 672
 673 struct subchannel *cio_probe_console(void)
 674 {
 675         struct subchannel_id schid;
 676         struct subchannel *sch;
 677         int sch_no, ret;
 678
 679         sch_no = cio_get_console_sch_no();
 680         if (sch_no == -1) {
 681                 pr_warning("No CCW console was found\n");
 682                 return ERR_PTR(-ENODEV);
 683         }
 684         init_subchannel_id(&schid);
 685         schid.sch_no = sch_no;
 686         sch = css_alloc_subchannel(schid);
 687         if (IS_ERR(sch))
 688                 return sch;
 689
 690         lockdep_set_class(sch->lock, &console_sch_key);
 691         isc_register(CONSOLE_ISC);
 692         sch->config.isc = CONSOLE_ISC;
 693         sch->config.intparm = (u32)(addr_t)sch;
 694         ret = cio_commit_config(sch);
 695         if (ret) {
 696                 isc_unregister(CONSOLE_ISC);
 697                 put_device(&sch->dev);
 698                 return ERR_PTR(ret);
 699         }
 700         console_sch = sch;
 701         return sch;
 702 }
 703
 704 int cio_is_console(struct subchannel_id schid)
 705 {
 706         if (!console_sch)
 707                 return 0;
 708         return schid_equal(&schid, &console_sch->schid);
 709 }
 710
 711 void cio_register_early_subchannels(void)
 712 {
 713         int ret;
 714
 715         if (!console_sch)
 716                 return;
 717
 718         ret = css_register_subchannel(console_sch);
 719         if (ret)
 720                 put_device(&console_sch->dev);
 721 }
 722 #endif /* CONFIG_CCW_CONSOLE */
 723
 724 static int
 725 __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
 726 {
 727         int retry, cc;
 728
 729         cc = 0;
 730         for (retry=0;retry<3;retry++) {
 731                 schib->pmcw.ena = 0;
 732                 cc = msch_err(schid, schib);
 733                 if (cc)
 734                         return (cc==3?-ENODEV:-EBUSY);
 735                 if (stsch_err(schid, schib) || !css_sch_is_valid(schib))
 736                         return -ENODEV;
 737                 if (!schib->pmcw.ena)
 738                         return 0;
 739         }
 740         return -EBUSY; /* uhm... */
 741 }
 742
 743 static int
 744 __clear_io_subchannel_easy(struct subchannel_id schid)
 745 {
 746         int retry;
 747
 748         if (csch(schid))
 749                 return -ENODEV;
 750         for (retry=0;retry<20;retry++) {
 751                 struct tpi_info ti;
 752
 753                 if (tpi(&ti)) {
 754                         tsch(ti.schid, &__get_cpu_var(cio_irb));
 755                         if (schid_equal(&ti.schid, &schid))
 756                                 return 0;
 757                 }
 758                 udelay_simple(100);
 759         }
 760         return -EBUSY;
 761 }
 762
 763 static void __clear_chsc_subchannel_easy(void)
 764 {
 765         /* It seems we can only wait for a bit here :/ */
 766         udelay_simple(100);
 767 }
 768
 769 static int pgm_check_occured;
 770
 771 static void cio_reset_pgm_check_handler(void)
 772 {
 773         pgm_check_occured = 1;
 774 }
 775
 776 static int stsch_reset(struct subchannel_id schid, struct schib *addr)
 777 {
 778         int rc;
 779
 780         pgm_check_occured = 0;
 781         s390_base_pgm_handler_fn = cio_reset_pgm_check_handler;
 782         rc = stsch_err(schid, addr);
 783         s390_base_pgm_handler_fn = NULL;
 784
 785         /* The program check handler could have changed pgm_check_occured. */
 786         barrier();
 787
 788         if (pgm_check_occured)
 789                 return -EIO;
 790         else
 791                 return rc;
 792 }
 793
 794 static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
 795 {
 796         struct schib schib;
 797
 798         if (stsch_reset(schid, &schib))
 799                 return -ENXIO;
 800         if (!schib.pmcw.ena)
 801                 return 0;
 802         switch(__disable_subchannel_easy(schid, &schib)) {
 803         case 0:
 804         case -ENODEV:
 805                 break;
 806         default: /* -EBUSY */
 807                 switch (schib.pmcw.st) {
 808                 case SUBCHANNEL_TYPE_IO:
 809                         if (__clear_io_subchannel_easy(schid))
 810                                 goto out; /* give up... */
 811                         break;
 812                 case SUBCHANNEL_TYPE_CHSC:
 813                         __clear_chsc_subchannel_easy();
 814                         break;
 815                 default:
 816                         /* No default clear strategy */
 817                         break;
 818                 }
 819                 stsch_err(schid, &schib);
 820                 __disable_subchannel_easy(schid, &schib);
 821         }
 822 out:
 823         return 0;
 824 }
 825
 826 static atomic_t chpid_reset_count;
 827
 828 static void s390_reset_chpids_mcck_handler(void)
 829 {
 830         struct crw crw;
 831         struct mci *mci;
 832
 833         /* Check for pending channel report word. */
 834         mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
 835         if (!mci->cp)
 836                 return;
 837         /* Process channel report words. */
 838         while (stcrw(&crw) == 0) {
 839                 /* Check for responses to RCHP. */
 840                 if (crw.slct && crw.rsc == CRW_RSC_CPATH)
 841                         atomic_dec(&chpid_reset_count);
 842         }
 843 }
 844
 845 #define RCHP_TIMEOUT (30 * USEC_PER_SEC)
 846 static void css_reset(void)
 847 {
 848         int i, ret;
 849         unsigned long long timeout;
 850         struct chp_id chpid;
 851
 852         /* Reset subchannels. */
 853         for_each_subchannel(__shutdown_subchannel_easy,  NULL);
 854         /* Reset channel paths. */
 855         s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler;
 856         /* Enable channel report machine checks. */
 857         __ctl_set_bit(14, 28);
 858         /* Temporarily reenable machine checks. */
 859         local_mcck_enable();
 860         chp_id_init(&chpid);
 861         for (i = 0; i <= __MAX_CHPID; i++) {
 862                 chpid.id = i;
 863                 ret = rchp(chpid);
 864                 if ((ret == 0) || (ret == 2))
 865                         /*
 866                          * rchp either succeeded, or another rchp is already
 867                          * in progress. In either case, we'll get a crw.
 868                          */
 869                         atomic_inc(&chpid_reset_count);
 870         }
 871         /* Wait for machine check for all channel paths. */
 872         timeout = get_tod_clock_fast() + (RCHP_TIMEOUT << 12);
 873         while (atomic_read(&chpid_reset_count) != 0) {
 874                 if (get_tod_clock_fast() > timeout)
 875                         break;
 876                 cpu_relax();
 877         }
 878         /* Disable machine checks again. */
 879         local_mcck_disable();
 880         /* Disable channel report machine checks. */
 881         __ctl_clear_bit(14, 28);
 882         s390_base_mcck_handler_fn = NULL;
 883 }
 884
 885 static struct reset_call css_reset_call = {
 886         .fn = css_reset,
 887 };
 888
 889 static int __init init_css_reset_call(void)
 890 {
 891         atomic_set(&chpid_reset_count, 0);
 892         register_reset_call(&css_reset_call);
 893         return 0;
 894 }
 895
 896 arch_initcall(init_css_reset_call);
 897
 898 struct sch_match_id {
 899         struct subchannel_id schid;
 900         struct ccw_dev_id devid;
 901         int rc;
 902 };
 903
 904 static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
 905 {
 906         struct schib schib;
 907         struct sch_match_id *match_id = data;
 908
 909         if (stsch_reset(schid, &schib))
 910                 return -ENXIO;
 911         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
 912             (schib.pmcw.dev == match_id->devid.devno) &&
 913             (schid.ssid == match_id->devid.ssid)) {
 914                 match_id->schid = schid;
 915                 match_id->rc = 0;
 916                 return 1;
 917         }
 918         return 0;
 919 }
 920
 921 static int reipl_find_schid(struct ccw_dev_id *devid,
 922                             struct subchannel_id *schid)
 923 {
 924         struct sch_match_id match_id;
 925
 926         match_id.devid = *devid;
 927         match_id.rc = -ENODEV;
 928         for_each_subchannel(__reipl_subchannel_match, &match_id);
 929         if (match_id.rc == 0)
 930                 *schid = match_id.schid;
 931         return match_id.rc;
 932 }
 933
 934 extern void do_reipl_asm(__u32 schid);
 935
 936 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
 937 void reipl_ccw_dev(struct ccw_dev_id *devid)
 938 {
 939         struct subchannel_id uninitialized_var(schid);
 940
 941         s390_reset_system(NULL, NULL);
 942         if (reipl_find_schid(devid, &schid) != 0)
 943                 panic("IPL Device not found\n");
 944         do_reipl_asm(*((__u32*)&schid));
 945 }
 946
 947 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
 948 {
 949         struct subchannel_id schid;
 950         struct schib schib;
 951
 952         schid = *(struct subchannel_id *)&S390_lowcore.subchannel_id;
 953         if (!schid.one)
 954                 return -ENODEV;
 955         if (stsch_err(schid, &schib))
 956                 return -ENODEV;
 957         if (schib.pmcw.st != SUBCHANNEL_TYPE_IO)
 958                 return -ENODEV;
 959         if (!schib.pmcw.dnv)
 960                 return -ENODEV;
 961         iplinfo->devno = schib.pmcw.dev;
 962         iplinfo->is_qdio = schib.pmcw.qf;
 963         return 0;
 964 }
 965
 966 /**
 967  * cio_tm_start_key - perform start function
 968  * @sch: subchannel on which to perform the start function
 969  * @tcw: transport-command word to be started
 970  * @lpm: mask of paths to use
 971  * @key: storage key to use for storage access
 972  *
 973  * Start the tcw on the given subchannel. Return zero on success, non-zero
 974  * otherwise.
 975  */
 976 int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
 977 {
 978         int cc;
 979         union orb *orb = &to_io_private(sch)->orb;
 980
 981         memset(orb, 0, sizeof(union orb));
 982         orb->tm.intparm = (u32) (addr_t) sch;
 983         orb->tm.key = key >> 4;
 984         orb->tm.b = 1;
 985         orb->tm.lpm = lpm ? lpm : sch->lpm;
 986         orb->tm.tcw = (u32) (addr_t) tcw;
 987         cc = ssch(sch->schid, orb);
 988         switch (cc) {
 989         case 0:
 990                 return 0;
 991         case 1:
 992         case 2:
 993                 return -EBUSY;
 994         default:
 995                 return cio_start_handle_notoper(sch, lpm);
 996         }
 997 }
 998
 999 /**
1000  * cio_tm_intrg - perform interrogate function
1001  * @sch - subchannel on which to perform the interrogate function
1002  *
1003  * If the specified subchannel is running in transport-mode, perform the
1004  * interrogate function. Return zero on success, non-zero otherwie.
1005  */
1006 int cio_tm_intrg(struct subchannel *sch)
1007 {
1008         int cc;
1009
1010         if (!to_io_private(sch)->orb.tm.b)
1011                 return -EINVAL;
1012         cc = xsch(sch->schid);
1013         switch (cc) {
1014         case 0:
1015         case 2:
1016                 return 0;
1017         case 1:
1018                 return -EBUSY;
1019         default:
1020                 return -ENODEV;
1021         }
1022 }