drivers/s390/cio/chsc.c

   1 /*
   2  *  drivers/s390/cio/chsc.c
   3  *   S/390 common I/O routines -- channel subsystem call
   4  *   $Revision: 1.120 $
   5  *
   6  *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
   7  *                            IBM Corporation
   8  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
   9  *               Cornelia Huck (cohuck@de.ibm.com)
  10  *               Arnd Bergmann (arndb@de.ibm.com)
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/config.h>
  15 #include <linux/slab.h>
  16 #include <linux/init.h>
  17 #include <linux/device.h>
  18
  19 #include <asm/cio.h>
  20
  21 #include "css.h"
  22 #include "cio.h"
  23 #include "cio_debug.h"
  24 #include "ioasm.h"
  25 #include "chsc.h"
  26
  27 static struct channel_path *chps[NR_CHPIDS];
  28
  29 static void *sei_page;
  30
  31 static int new_channel_path(int chpid);
  32
  33 static inline void
  34 set_chp_logically_online(int chp, int onoff)
  35 {
  36         chps[chp]->state = onoff;
  37 }
  38
  39 static int
  40 get_chp_status(int chp)
  41 {
  42         return (chps[chp] ? chps[chp]->state : -ENODEV);
  43 }
  44
  45 void
  46 chsc_validate_chpids(struct subchannel *sch)
  47 {
  48         int mask, chp;
  49
  50         for (chp = 0; chp <= 7; chp++) {
  51                 mask = 0x80 >> chp;
  52                 if (!get_chp_status(sch->schib.pmcw.chpid[chp]))
  53                         /* disable using this path */
  54                         sch->opm &= ~mask;
  55         }
  56 }
  57
  58 void
  59 chpid_is_actually_online(int chp)
  60 {
  61         int state;
  62
  63         state = get_chp_status(chp);
  64         if (state < 0) {
  65                 need_rescan = 1;
  66                 queue_work(slow_path_wq, &slow_path_work);
  67         } else
  68                 WARN_ON(!state);
  69 }
  70
  71 /* FIXME: this is _always_ called for every subchannel. shouldn't we
  72  *        process more than one at a time? */
  73 static int
  74 chsc_get_sch_desc_irq(struct subchannel *sch, void *page)
  75 {
  76         int ccode, j;
  77
  78         struct {
  79                 struct chsc_header request;
  80                 u16 reserved1;
  81                 u16 f_sch;        /* first subchannel */
  82                 u16 reserved2;
  83                 u16 l_sch;        /* last subchannel */
  84                 u32 reserved3;
  85                 struct chsc_header response;
  86                 u32 reserved4;
  87                 u8 sch_valid : 1;
  88                 u8 dev_valid : 1;
  89                 u8 st        : 3; /* subchannel type */
  90                 u8 zeroes    : 3;
  91                 u8  unit_addr;    /* unit address */
  92                 u16 devno;        /* device number */
  93                 u8 path_mask;
  94                 u8 fla_valid_mask;
  95                 u16 sch;          /* subchannel */
  96                 u8 chpid[8];      /* chpids 0-7 */
  97                 u16 fla[8];       /* full link addresses 0-7 */
  98         } *ssd_area;
  99
 100         ssd_area = page;
 101
 102         ssd_area->request = (struct chsc_header) {
 103                 .length = 0x0010,
 104                 .code   = 0x0004,
 105         };
 106
 107         ssd_area->f_sch = sch->irq;
 108         ssd_area->l_sch = sch->irq;
 109
 110         ccode = chsc(ssd_area);
 111         if (ccode > 0) {
 112                 pr_debug("chsc returned with ccode = %d\n", ccode);
 113                 return (ccode == 3) ? -ENODEV : -EBUSY;
 114         }
 115
 116         switch (ssd_area->response.code) {
 117         case 0x0001: /* everything ok */
 118                 break;
 119         case 0x0002:
 120                 CIO_CRW_EVENT(2, "Invalid command!\n");
 121                 return -EINVAL;
 122         case 0x0003:
 123                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
 124                 return -EINVAL;
 125         case 0x0004:
 126                 CIO_CRW_EVENT(2, "Model does not provide ssd\n");
 127                 return -EOPNOTSUPP;
 128         default:
 129                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
 130                               ssd_area->response.code);
 131                 return -EIO;
 132         }
 133
 134         /*
 135          * ssd_area->st stores the type of the detected
 136          * subchannel, with the following definitions:
 137          *
 138          * 0: I/O subchannel:     All fields have meaning
 139          * 1: CHSC subchannel:    Only sch_val, st and sch
 140          *                        have meaning
 141          * 2: Message subchannel: All fields except unit_addr
 142          *                        have meaning
 143          * 3: ADM subchannel:     Only sch_val, st and sch
 144          *                        have meaning
 145          *
 146          * Other types are currently undefined.
 147          */
 148         if (ssd_area->st > 3) { /* uhm, that looks strange... */
 149                 CIO_CRW_EVENT(0, "Strange subchannel type %d"
 150                               " for sch %04x\n", ssd_area->st, sch->irq);
 151                 /*
 152                  * There may have been a new subchannel type defined in the
 153                  * time since this code was written; since we don't know which
 154                  * fields have meaning and what to do with it we just jump out
 155                  */
 156                 return 0;
 157         } else {
 158                 const char *type[4] = {"I/O", "chsc", "message", "ADM"};
 159                 CIO_CRW_EVENT(6, "ssd: sch %04x is %s subchannel\n",
 160                               sch->irq, type[ssd_area->st]);
 161
 162                 sch->ssd_info.valid = 1;
 163                 sch->ssd_info.type = ssd_area->st;
 164         }
 165
 166         if (ssd_area->st == 0 || ssd_area->st == 2) {
 167                 for (j = 0; j < 8; j++) {
 168                         if (!((0x80 >> j) & ssd_area->path_mask &
 169                               ssd_area->fla_valid_mask))
 170                                 continue;
 171                         sch->ssd_info.chpid[j] = ssd_area->chpid[j];
 172                         sch->ssd_info.fla[j]   = ssd_area->fla[j];
 173                 }
 174         }
 175         return 0;
 176 }
 177
 178 int
 179 css_get_ssd_info(struct subchannel *sch)
 180 {
 181         int ret;
 182         void *page;
 183
 184         page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
 185         if (!page)
 186                 return -ENOMEM;
 187         spin_lock_irq(&sch->lock);
 188         ret = chsc_get_sch_desc_irq(sch, page);
 189         if (ret) {
 190                 static int cio_chsc_err_msg;
 191
 192                 if (!cio_chsc_err_msg) {
 193                         printk(KERN_ERR
 194                                "chsc_get_sch_descriptions:"
 195                                " Error %d while doing chsc; "
 196                                "processing some machine checks may "
 197                                "not work\n", ret);
 198                         cio_chsc_err_msg = 1;
 199                 }
 200         }
 201         spin_unlock_irq(&sch->lock);
 202         free_page((unsigned long)page);
 203         if (!ret) {
 204                 int j, chpid;
 205                 /* Allocate channel path structures, if needed. */
 206                 for (j = 0; j < 8; j++) {
 207                         chpid = sch->ssd_info.chpid[j];
 208                         if (chpid && (get_chp_status(chpid) < 0))
 209                             new_channel_path(chpid);
 210                 }
 211         }
 212         return ret;
 213 }
 214
 215 static int
 216 s390_subchannel_remove_chpid(struct device *dev, void *data)
 217 {
 218         int j;
 219         int mask;
 220         struct subchannel *sch;
 221         __u8 *chpid;
 222         struct schib schib;
 223
 224         sch = to_subchannel(dev);
 225         chpid = data;
 226         for (j = 0; j < 8; j++)
 227                 if (sch->schib.pmcw.chpid[j] == *chpid)
 228                         break;
 229         if (j >= 8)
 230                 return 0;
 231
 232         mask = 0x80 >> j;
 233         spin_lock(&sch->lock);
 234
 235         stsch(sch->irq, &schib);
 236         if (!schib.pmcw.dnv)
 237                 goto out_unreg;
 238         memcpy(&sch->schib, &schib, sizeof(struct schib));
 239         /* Check for single path devices. */
 240         if (sch->schib.pmcw.pim == 0x80)
 241                 goto out_unreg;
 242         if (sch->vpm == mask)
 243                 goto out_unreg;
 244
 245         if ((sch->schib.scsw.actl & (SCSW_ACTL_CLEAR_PEND |
 246                                      SCSW_ACTL_HALT_PEND |
 247                                      SCSW_ACTL_START_PEND |
 248                                      SCSW_ACTL_RESUME_PEND)) &&
 249             (sch->schib.pmcw.lpum == mask)) {
 250                 int cc = cio_cancel(sch);
 251
 252                 if (cc == -ENODEV)
 253                         goto out_unreg;
 254
 255                 if (cc == -EINVAL) {
 256                         cc = cio_clear(sch);
 257                         if (cc == -ENODEV)
 258                                 goto out_unreg;
 259                         /* Call handler. */
 260                         if (sch->driver && sch->driver->termination)
 261                                 sch->driver->termination(&sch->dev);
 262                         goto out_unlock;
 263                 }
 264         } else if ((sch->schib.scsw.actl & SCSW_ACTL_DEVACT) &&
 265                    (sch->schib.scsw.actl & SCSW_ACTL_SCHACT) &&
 266                    (sch->schib.pmcw.lpum == mask)) {
 267                 int cc;
 268
 269                 cc = cio_clear(sch);
 270                 if (cc == -ENODEV)
 271                         goto out_unreg;
 272                 /* Call handler. */
 273                 if (sch->driver && sch->driver->termination)
 274                         sch->driver->termination(&sch->dev);
 275                 goto out_unlock;
 276         }
 277
 278         /* trigger path verification. */
 279         if (sch->driver && sch->driver->verify)
 280                 sch->driver->verify(&sch->dev);
 281 out_unlock:
 282         spin_unlock(&sch->lock);
 283         return 0;
 284 out_unreg:
 285         spin_unlock(&sch->lock);
 286         sch->lpm = 0;
 287         if (css_enqueue_subchannel_slow(sch->irq)) {
 288                 css_clear_subchannel_slow_list();
 289                 need_rescan = 1;
 290         }
 291         return 0;
 292 }
 293
 294 static inline void
 295 s390_set_chpid_offline( __u8 chpid)
 296 {
 297         char dbf_txt[15];
 298
 299         sprintf(dbf_txt, "chpr%x", chpid);
 300         CIO_TRACE_EVENT(2, dbf_txt);
 301
 302         if (get_chp_status(chpid) <= 0)
 303                 return;
 304
 305         bus_for_each_dev(&css_bus_type, NULL, &chpid,
 306                          s390_subchannel_remove_chpid);
 307
 308         if (need_rescan || css_slow_subchannels_exist())
 309                 queue_work(slow_path_wq, &slow_path_work);
 310 }
 311
 312 static int
 313 s390_process_res_acc_sch(u8 chpid, __u16 fla, u32 fla_mask,
 314                          struct subchannel *sch)
 315 {
 316         int found;
 317         int chp;
 318         int ccode;
 319
 320         found = 0;
 321         for (chp = 0; chp <= 7; chp++)
 322                 /*
 323                  * check if chpid is in information updated by ssd
 324                  */
 325                 if (sch->ssd_info.valid &&
 326                     sch->ssd_info.chpid[chp] == chpid &&
 327                     (sch->ssd_info.fla[chp] & fla_mask) == fla) {
 328                         found = 1;
 329                         break;
 330                 }
 331
 332         if (found == 0)
 333                 return 0;
 334
 335         /*
 336          * Do a stsch to update our subchannel structure with the
 337          * new path information and eventually check for logically
 338          * offline chpids.
 339          */
 340         ccode = stsch(sch->irq, &sch->schib);
 341         if (ccode > 0)
 342                 return 0;
 343
 344         return 0x80 >> chp;
 345 }
 346
 347 static int
 348 s390_process_res_acc (u8 chpid, __u16 fla, u32 fla_mask)
 349 {
 350         struct subchannel *sch;
 351         int irq, rc;
 352         char dbf_txt[15];
 353
 354         sprintf(dbf_txt, "accpr%x", chpid);
 355         CIO_TRACE_EVENT( 2, dbf_txt);
 356         if (fla != 0) {
 357                 sprintf(dbf_txt, "fla%x", fla);
 358                 CIO_TRACE_EVENT( 2, dbf_txt);
 359         }
 360
 361         /*
 362          * I/O resources may have become accessible.
 363          * Scan through all subchannels that may be concerned and
 364          * do a validation on those.
 365          * The more information we have (info), the less scanning
 366          * will we have to do.
 367          */
 368
 369         if (!get_chp_status(chpid))
 370                 return 0; /* no need to do the rest */
 371
 372         rc = 0;
 373         for (irq = 0; irq < __MAX_SUBCHANNELS; irq++) {
 374                 int chp_mask, old_lpm;
 375
 376                 sch = get_subchannel_by_schid(irq);
 377                 if (!sch) {
 378                         struct schib schib;
 379                         int ret;
 380                         /*
 381                          * We don't know the device yet, but since a path
 382                          * may be available now to the device we'll have
 383                          * to do recognition again.
 384                          * Since we don't have any idea about which chpid
 385                          * that beast may be on we'll have to do a stsch
 386                          * on all devices, grr...
 387                          */
 388                         if (stsch(irq, &schib)) {
 389                                 /* We're through */
 390                                 if (need_rescan)
 391                                         rc = -EAGAIN;
 392                                 break;
 393                         }
 394                         if (need_rescan) {
 395                                 rc = -EAGAIN;
 396                                 continue;
 397                         }
 398                         /* Put it on the slow path. */
 399                         ret = css_enqueue_subchannel_slow(irq);
 400                         if (ret) {
 401                                 css_clear_subchannel_slow_list();
 402                                 need_rescan = 1;
 403                         }
 404                         rc = -EAGAIN;
 405                         continue;
 406                 }
 407
 408                 spin_lock_irq(&sch->lock);
 409
 410                 chp_mask = s390_process_res_acc_sch(chpid, fla, fla_mask, sch);
 411
 412                 if (chp_mask == 0) {
 413
 414                         spin_unlock_irq(&sch->lock);
 415                         continue;
 416                 }
 417                 old_lpm = sch->lpm;
 418                 sch->lpm = ((sch->schib.pmcw.pim &
 419                              sch->schib.pmcw.pam &
 420                              sch->schib.pmcw.pom)
 421                             | chp_mask) & sch->opm;
 422                 if (!old_lpm && sch->lpm)
 423                         device_trigger_reprobe(sch);
 424                 else if (sch->driver && sch->driver->verify)
 425                         sch->driver->verify(&sch->dev);
 426
 427                 spin_unlock_irq(&sch->lock);
 428                 put_device(&sch->dev);
 429                 if (fla_mask == 0xffff)
 430                         break;
 431         }
 432         return rc;
 433 }
 434
 435 static int
 436 __get_chpid_from_lir(void *data)
 437 {
 438         struct lir {
 439                 u8  iq;
 440                 u8  ic;
 441                 u16 sci;
 442                 /* incident-node descriptor */
 443                 u32 indesc[28];
 444                 /* attached-node descriptor */
 445                 u32 andesc[28];
 446                 /* incident-specific information */
 447                 u32 isinfo[28];
 448         } *lir;
 449
 450         lir = (struct lir*) data;
 451         if (!(lir->iq&0x80))
 452                 /* NULL link incident record */
 453                 return -EINVAL;
 454         if (!(lir->indesc[0]&0xc0000000))
 455                 /* node descriptor not valid */
 456                 return -EINVAL;
 457         if (!(lir->indesc[0]&0x10000000))
 458                 /* don't handle device-type nodes - FIXME */
 459                 return -EINVAL;
 460         /* Byte 3 contains the chpid. Could also be CTCA, but we don't care */
 461
 462         return (u16) (lir->indesc[0]&0x000000ff);
 463 }
 464
 465 int
 466 chsc_process_crw(void)
 467 {
 468         int chpid, ret;
 469         struct {
 470                 struct chsc_header request;
 471                 u32 reserved1;
 472                 u32 reserved2;
 473                 u32 reserved3;
 474                 struct chsc_header response;
 475                 u32 reserved4;
 476                 u8  flags;
 477                 u8  vf;         /* validity flags */
 478                 u8  rs;         /* reporting source */
 479                 u8  cc;         /* content code */
 480                 u16 fla;        /* full link address */
 481                 u16 rsid;       /* reporting source id */
 482                 u32 reserved5;
 483                 u32 reserved6;
 484                 u32 ccdf[96];   /* content-code dependent field */
 485                 /* ccdf has to be big enough for a link-incident record */
 486         } *sei_area;
 487
 488         if (!sei_page)
 489                 return 0;
 490         /*
 491          * build the chsc request block for store event information
 492          * and do the call
 493          * This function is only called by the machine check handler thread,
 494          * so we don't need locking for the sei_page.
 495          */
 496         sei_area = sei_page;
 497
 498         CIO_TRACE_EVENT( 2, "prcss");
 499         ret = 0;
 500         do {
 501                 int ccode, status;
 502                 memset(sei_area, 0, sizeof(*sei_area));
 503
 504                 sei_area->request = (struct chsc_header) {
 505                         .length = 0x0010,
 506                         .code   = 0x000e,
 507                 };
 508
 509                 ccode = chsc(sei_area);
 510                 if (ccode > 0)
 511                         return 0;
 512
 513                 switch (sei_area->response.code) {
 514                         /* for debug purposes, check for problems */
 515                 case 0x0001:
 516                         CIO_CRW_EVENT(4, "chsc_process_crw: event information "
 517                                         "successfully stored\n");
 518                         break; /* everything ok */
 519                 case 0x0002:
 520                         CIO_CRW_EVENT(2,
 521                                       "chsc_process_crw: invalid command!\n");
 522                         return 0;
 523                 case 0x0003:
 524                         CIO_CRW_EVENT(2, "chsc_process_crw: error in chsc "
 525                                       "request block!\n");
 526                         return 0;
 527                 case 0x0005:
 528                         CIO_CRW_EVENT(2, "chsc_process_crw: no event "
 529                                       "information stored\n");
 530                         return 0;
 531                 default:
 532                         CIO_CRW_EVENT(2, "chsc_process_crw: chsc response %d\n",
 533                                       sei_area->response.code);
 534                         return 0;
 535                 }
 536
 537                 /* Check if we might have lost some information. */
 538                 if (sei_area->flags & 0x40)
 539                         CIO_CRW_EVENT(2, "chsc_process_crw: Event information "
 540                                        "has been lost due to overflow!\n");
 541
 542                 if (sei_area->rs != 4) {
 543                         CIO_CRW_EVENT(2, "chsc_process_crw: reporting source "
 544                                       "(%04X) isn't a chpid!\n",
 545                                       sei_area->rsid);
 546                         continue;
 547                 }
 548
 549                 /* which kind of information was stored? */
 550                 switch (sei_area->cc) {
 551                 case 1: /* link incident*/
 552                         CIO_CRW_EVENT(4, "chsc_process_crw: "
 553                                       "channel subsystem reports link incident,"
 554                                       " reporting source is chpid %x\n",
 555                                       sei_area->rsid);
 556                         chpid = __get_chpid_from_lir(sei_area->ccdf);
 557                         if (chpid < 0)
 558                                 CIO_CRW_EVENT(4, "%s: Invalid LIR, skipping\n",
 559                                               __FUNCTION__);
 560                         else
 561                                 s390_set_chpid_offline(chpid);
 562                         break;
 563
 564                 case 2: /* i/o resource accessibiliy */
 565                         CIO_CRW_EVENT(4, "chsc_process_crw: "
 566                                       "channel subsystem reports some I/O "
 567                                       "devices may have become accessible\n");
 568                         pr_debug("Data received after sei: \n");
 569                         pr_debug("Validity flags: %x\n", sei_area->vf);
 570
 571                         /* allocate a new channel path structure, if needed */
 572                         status = get_chp_status(sei_area->rsid);
 573                         if (status < 0)
 574                                 new_channel_path(sei_area->rsid);
 575                         else if (!status)
 576                                 return 0;
 577                         if ((sei_area->vf & 0x80) == 0) {
 578                                 pr_debug("chpid: %x\n", sei_area->rsid);
 579                                 ret = s390_process_res_acc(sei_area->rsid,
 580                                                            0, 0);
 581                         } else if ((sei_area->vf & 0xc0) == 0x80) {
 582                                 pr_debug("chpid: %x link addr: %x\n",
 583                                          sei_area->rsid, sei_area->fla);
 584                                 ret = s390_process_res_acc(sei_area->rsid,
 585                                                            sei_area->fla,
 586                                                            0xff00);
 587                         } else if ((sei_area->vf & 0xc0) == 0xc0) {
 588                                 pr_debug("chpid: %x full link addr: %x\n",
 589                                          sei_area->rsid, sei_area->fla);
 590                                 ret = s390_process_res_acc(sei_area->rsid,
 591                                                            sei_area->fla,
 592                                                            0xffff);
 593                         }
 594                         pr_debug("\n");
 595
 596                         break;
 597
 598                 default: /* other stuff */
 599                         CIO_CRW_EVENT(4, "chsc_process_crw: event %d\n",
 600                                       sei_area->cc);
 601                         break;
 602                 }
 603         } while (sei_area->flags & 0x80);
 604         return ret;
 605 }
 606
 607 static int
 608 chp_add(int chpid)
 609 {
 610         struct subchannel *sch;
 611         int irq, ret, rc;
 612         char dbf_txt[15];
 613
 614         if (!get_chp_status(chpid))
 615                 return 0; /* no need to do the rest */
 616
 617         sprintf(dbf_txt, "cadd%x", chpid);
 618         CIO_TRACE_EVENT(2, dbf_txt);
 619
 620         rc = 0;
 621         for (irq = 0; irq < __MAX_SUBCHANNELS; irq++) {
 622                 int i;
 623
 624                 sch = get_subchannel_by_schid(irq);
 625                 if (!sch) {
 626                         struct schib schib;
 627
 628                         if (stsch(irq, &schib)) {
 629                                 /* We're through */
 630                                 if (need_rescan)
 631                                         rc = -EAGAIN;
 632                                 break;
 633                         }
 634                         if (need_rescan) {
 635                                 rc = -EAGAIN;
 636                                 continue;
 637                         }
 638                         /* Put it on the slow path. */
 639                         ret = css_enqueue_subchannel_slow(irq);
 640                         if (ret) {
 641                                 css_clear_subchannel_slow_list();
 642                                 need_rescan = 1;
 643                         }
 644                         rc = -EAGAIN;
 645                         continue;
 646                 }
 647
 648                 spin_lock(&sch->lock);
 649                 for (i=0; i<8; i++)
 650                         if (sch->schib.pmcw.chpid[i] == chpid) {
 651                                 if (stsch(sch->irq, &sch->schib) != 0) {
 652                                         /* Endgame. */
 653                                         spin_unlock(&sch->lock);
 654                                         return rc;
 655                                 }
 656                                 break;
 657                         }
 658                 if (i==8) {
 659                         spin_unlock(&sch->lock);
 660                         return rc;
 661                 }
 662                 sch->lpm = ((sch->schib.pmcw.pim &
 663                              sch->schib.pmcw.pam &
 664                              sch->schib.pmcw.pom)
 665                             | 0x80 >> i) & sch->opm;
 666
 667                 if (sch->driver && sch->driver->verify)
 668                         sch->driver->verify(&sch->dev);
 669
 670                 spin_unlock(&sch->lock);
 671                 put_device(&sch->dev);
 672         }
 673         return rc;
 674 }
 675
 676 /*
 677  * Handling of crw machine checks with channel path source.
 678  */
 679 int
 680 chp_process_crw(int chpid, int on)
 681 {
 682         if (on == 0) {
 683                 /* Path has gone. We use the link incident routine.*/
 684                 s390_set_chpid_offline(chpid);
 685                 return 0; /* De-register is async anyway. */
 686         }
 687         /*
 688          * Path has come. Allocate a new channel path structure,
 689          * if needed.
 690          */
 691         if (get_chp_status(chpid) < 0)
 692                 new_channel_path(chpid);
 693         /* Avoid the extra overhead in process_rec_acc. */
 694         return chp_add(chpid);
 695 }
 696
 697 static inline int
 698 __check_for_io_and_kill(struct subchannel *sch, int index)
 699 {
 700         int cc;
 701
 702         if (!device_is_online(sch))
 703                 /* cio could be doing I/O. */
 704                 return 0;
 705         cc = stsch(sch->irq, &sch->schib);
 706         if (cc)
 707                 return 0;
 708         if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index)) {
 709                 device_set_waiting(sch);
 710                 return 1;
 711         }
 712         return 0;
 713 }
 714
 715 static inline void
 716 __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
 717 {
 718         int chp, old_lpm;
 719         unsigned long flags;
 720
 721         if (!sch->ssd_info.valid)
 722                 return;
 723
 724         spin_lock_irqsave(&sch->lock, flags);
 725         old_lpm = sch->lpm;
 726         for (chp = 0; chp < 8; chp++) {
 727                 if (sch->ssd_info.chpid[chp] != chpid)
 728                         continue;
 729
 730                 if (on) {
 731                         sch->opm |= (0x80 >> chp);
 732                         sch->lpm |= (0x80 >> chp);
 733                         if (!old_lpm)
 734                                 device_trigger_reprobe(sch);
 735                         else if (sch->driver && sch->driver->verify)
 736                                 sch->driver->verify(&sch->dev);
 737                 } else {
 738                         sch->opm &= ~(0x80 >> chp);
 739                         sch->lpm &= ~(0x80 >> chp);
 740                         /*
 741                          * Give running I/O a grace period in which it
 742                          * can successfully terminate, even using the
 743                          * just varied off path. Then kill it.
 744                          */
 745                         if (!__check_for_io_and_kill(sch, chp) && !sch->lpm) {
 746                                 if (css_enqueue_subchannel_slow(sch->irq)) {
 747                                         css_clear_subchannel_slow_list();
 748                                         need_rescan = 1;
 749                                 }
 750                         } else if (sch->driver && sch->driver->verify)
 751                                 sch->driver->verify(&sch->dev);
 752                 }
 753                 break;
 754         }
 755         spin_unlock_irqrestore(&sch->lock, flags);
 756 }
 757
 758 static int
 759 s390_subchannel_vary_chpid_off(struct device *dev, void *data)
 760 {
 761         struct subchannel *sch;
 762         __u8 *chpid;
 763
 764         sch = to_subchannel(dev);
 765         chpid = data;
 766
 767         __s390_subchannel_vary_chpid(sch, *chpid, 0);
 768         return 0;
 769 }
 770
 771 static int
 772 s390_subchannel_vary_chpid_on(struct device *dev, void *data)
 773 {
 774         struct subchannel *sch;
 775         __u8 *chpid;
 776
 777         sch = to_subchannel(dev);
 778         chpid = data;
 779
 780         __s390_subchannel_vary_chpid(sch, *chpid, 1);
 781         return 0;
 782 }
 783
 784 /*
 785  * Function: s390_vary_chpid
 786  * Varies the specified chpid online or offline
 787  */
 788 static int
 789 s390_vary_chpid( __u8 chpid, int on)
 790 {
 791         char dbf_text[15];
 792         int status, irq, ret;
 793         struct subchannel *sch;
 794
 795         sprintf(dbf_text, on?"varyon%x":"varyoff%x", chpid);
 796         CIO_TRACE_EVENT( 2, dbf_text);
 797
 798         status = get_chp_status(chpid);
 799         if (status < 0) {
 800                 printk(KERN_ERR "Can't vary unknown chpid %02X\n", chpid);
 801                 return -EINVAL;
 802         }
 803
 804         if (!on && !status) {
 805                 printk(KERN_ERR "chpid %x is already offline\n", chpid);
 806                 return -EINVAL;
 807         }
 808
 809         set_chp_logically_online(chpid, on);
 810
 811         /*
 812          * Redo PathVerification on the devices the chpid connects to
 813          */
 814
 815         bus_for_each_dev(&css_bus_type, NULL, &chpid, on ?
 816                          s390_subchannel_vary_chpid_on :
 817                          s390_subchannel_vary_chpid_off);
 818         if (!on)
 819                 goto out;
 820         /* Scan for new devices on varied on path. */
 821         for (irq = 0; irq < __MAX_SUBCHANNELS; irq++) {
 822                 struct schib schib;
 823
 824                 if (need_rescan)
 825                         break;
 826                 sch = get_subchannel_by_schid(irq);
 827                 if (sch) {
 828                         put_device(&sch->dev);
 829                         continue;
 830                 }
 831                 if (stsch(irq, &schib))
 832                         /* We're through */
 833                         break;
 834                 /* Put it on the slow path. */
 835                 ret = css_enqueue_subchannel_slow(irq);
 836                 if (ret) {
 837                         css_clear_subchannel_slow_list();
 838                         need_rescan = 1;
 839                 }
 840         }
 841 out:
 842         if (need_rescan || css_slow_subchannels_exist())
 843                 queue_work(slow_path_wq, &slow_path_work);
 844         return 0;
 845 }
 846
 847 /*
 848  * Files for the channel path entries.
 849  */
 850 static ssize_t
 851 chp_status_show(struct device *dev, struct device_attribute *attr, char *buf)
 852 {
 853         struct channel_path *chp = container_of(dev, struct channel_path, dev);
 854
 855         if (!chp)
 856                 return 0;
 857         return (get_chp_status(chp->id) ? sprintf(buf, "online\n") :
 858                 sprintf(buf, "offline\n"));
 859 }
 860
 861 static ssize_t
 862 chp_status_write(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 863 {
 864         struct channel_path *cp = container_of(dev, struct channel_path, dev);
 865         char cmd[10];
 866         int num_args;
 867         int error;
 868
 869         num_args = sscanf(buf, "%5s", cmd);
 870         if (!num_args)
 871                 return count;
 872
 873         if (!strnicmp(cmd, "on", 2))
 874                 error = s390_vary_chpid(cp->id, 1);
 875         else if (!strnicmp(cmd, "off", 3))
 876                 error = s390_vary_chpid(cp->id, 0);
 877         else
 878                 error = -EINVAL;
 879
 880         return error < 0 ? error : count;
 881
 882 }
 883
 884 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
 885
 886 static ssize_t
 887 chp_type_show(struct device *dev, struct device_attribute *attr, char *buf)
 888 {
 889         struct channel_path *chp = container_of(dev, struct channel_path, dev);
 890
 891         if (!chp)
 892                 return 0;
 893         return sprintf(buf, "%x\n", chp->desc.desc);
 894 }
 895
 896 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
 897
 898 static struct attribute * chp_attrs[] = {
 899         &dev_attr_status.attr,
 900         &dev_attr_type.attr,
 901         NULL,
 902 };
 903
 904 static struct attribute_group chp_attr_group = {
 905         .attrs = chp_attrs,
 906 };
 907
 908 static void
 909 chp_release(struct device *dev)
 910 {
 911         struct channel_path *cp;
 912
 913         cp = container_of(dev, struct channel_path, dev);
 914         kfree(cp);
 915 }
 916
 917 static int
 918 chsc_determine_channel_path_description(int chpid,
 919                                         struct channel_path_desc *desc)
 920 {
 921         int ccode, ret;
 922
 923         struct {
 924                 struct chsc_header request;
 925                 u32 : 24;
 926                 u32 first_chpid : 8;
 927                 u32 : 24;
 928                 u32 last_chpid : 8;
 929                 u32 zeroes1;
 930                 struct chsc_header response;
 931                 u32 zeroes2;
 932                 struct channel_path_desc desc;
 933         } *scpd_area;
 934
 935         scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
 936         if (!scpd_area)
 937                 return -ENOMEM;
 938
 939         scpd_area->request = (struct chsc_header) {
 940                 .length = 0x0010,
 941                 .code   = 0x0002,
 942         };
 943
 944         scpd_area->first_chpid = chpid;
 945         scpd_area->last_chpid = chpid;
 946
 947         ccode = chsc(scpd_area);
 948         if (ccode > 0) {
 949                 ret = (ccode == 3) ? -ENODEV : -EBUSY;
 950                 goto out;
 951         }
 952
 953         switch (scpd_area->response.code) {
 954         case 0x0001: /* Success. */
 955                 memcpy(desc, &scpd_area->desc,
 956                        sizeof(struct channel_path_desc));
 957                 ret = 0;
 958                 break;
 959         case 0x0003: /* Invalid block. */
 960         case 0x0007: /* Invalid format. */
 961         case 0x0008: /* Other invalid block. */
 962                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
 963                 ret = -EINVAL;
 964                 break;
 965         case 0x0004: /* Command not provided in model. */
 966                 CIO_CRW_EVENT(2, "Model does not provide scpd\n");
 967                 ret = -EOPNOTSUPP;
 968                 break;
 969         default:
 970                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
 971                               scpd_area->response.code);
 972                 ret = -EIO;
 973         }
 974 out:
 975         free_page((unsigned long)scpd_area);
 976         return ret;
 977 }
 978
 979 /*
 980  * Entries for chpids on the system bus.
 981  * This replaces /proc/chpids.
 982  */
 983 static int
 984 new_channel_path(int chpid)
 985 {
 986         struct channel_path *chp;
 987         int ret;
 988
 989         chp = kmalloc(sizeof(struct channel_path), GFP_KERNEL);
 990         if (!chp)
 991                 return -ENOMEM;
 992         memset(chp, 0, sizeof(struct channel_path));
 993
 994         /* fill in status, etc. */
 995         chp->id = chpid;
 996         chp->state = 1;
 997         chp->dev = (struct device) {
 998                 .parent  = &css_bus_device,
 999                 .release = chp_release,
1000         };
1001         snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp0.%x", chpid);
1002
1003         /* Obtain channel path description and fill it in. */
1004         ret = chsc_determine_channel_path_description(chpid, &chp->desc);
1005         if (ret)
1006                 goto out_free;
1007
1008         /* make it known to the system */
1009         ret = device_register(&chp->dev);
1010         if (ret) {
1011                 printk(KERN_WARNING "%s: could not register %02x\n",
1012                        __func__, chpid);
1013                 goto out_free;
1014         }
1015         ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
1016         if (ret) {
1017                 device_unregister(&chp->dev);
1018                 goto out_free;
1019         } else
1020                 chps[chpid] = chp;
1021         return ret;
1022 out_free:
1023         kfree(chp);
1024         return ret;
1025 }
1026
1027 void *
1028 chsc_get_chp_desc(struct subchannel *sch, int chp_no)
1029 {
1030         struct channel_path *chp;
1031         struct channel_path_desc *desc;
1032
1033         chp = chps[sch->schib.pmcw.chpid[chp_no]];
1034         if (!chp)
1035                 return NULL;
1036         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
1037         if (!desc)
1038                 return NULL;
1039         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
1040         return desc;
1041 }
1042
1043
1044 static int __init
1045 chsc_alloc_sei_area(void)
1046 {
1047         sei_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1048         if (!sei_page)
1049                 printk(KERN_WARNING"Can't allocate page for processing of " \
1050                        "chsc machine checks!\n");
1051         return (sei_page ? 0 : -ENOMEM);
1052 }
1053
1054 subsys_initcall(chsc_alloc_sei_area);
1055
1056 struct css_general_char css_general_characteristics;
1057 struct css_chsc_char css_chsc_characteristics;
1058
1059 int __init
1060 chsc_determine_css_characteristics(void)
1061 {
1062         int result;
1063         struct {
1064                 struct chsc_header request;
1065                 u32 reserved1;
1066                 u32 reserved2;
1067                 u32 reserved3;
1068                 struct chsc_header response;
1069                 u32 reserved4;
1070                 u32 general_char[510];
1071                 u32 chsc_char[518];
1072         } *scsc_area;
1073
1074         scsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1075         if (!scsc_area) {
1076                 printk(KERN_WARNING"cio: Was not able to determine available" \
1077                        "CHSCs due to no memory.\n");
1078                 return -ENOMEM;
1079         }
1080
1081         scsc_area->request = (struct chsc_header) {
1082                 .length = 0x0010,
1083                 .code   = 0x0010,
1084         };
1085
1086         result = chsc(scsc_area);
1087         if (result) {
1088                 printk(KERN_WARNING"cio: Was not able to determine " \
1089                        "available CHSCs, cc=%i.\n", result);
1090                 result = -EIO;
1091                 goto exit;
1092         }
1093
1094         if (scsc_area->response.code != 1) {
1095                 printk(KERN_WARNING"cio: Was not able to determine " \
1096                        "available CHSCs.\n");
1097                 result = -EIO;
1098                 goto exit;
1099         }
1100         memcpy(&css_general_characteristics, scsc_area->general_char,
1101                sizeof(css_general_characteristics));
1102         memcpy(&css_chsc_characteristics, scsc_area->chsc_char,
1103                sizeof(css_chsc_characteristics));
1104 exit:
1105         free_page ((unsigned long) scsc_area);
1106         return result;
1107 }
1108
1109 EXPORT_SYMBOL_GPL(css_general_characteristics);
1110 EXPORT_SYMBOL_GPL(css_chsc_characteristics);