drivers/s390/cio/chsc.c

   1 /*
   2  *  drivers/s390/cio/chsc.c
   3  *   S/390 common I/O routines -- channel subsystem call
   4  *   $Revision: 1.119 $
   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
 416                         if (fla_mask != 0)
 417                                 break;
 418                         else
 419                                 continue;
 420                 }
 421                 old_lpm = sch->lpm;
 422                 sch->lpm = ((sch->schib.pmcw.pim &
 423                              sch->schib.pmcw.pam &
 424                              sch->schib.pmcw.pom)
 425                             | chp_mask) & sch->opm;
 426                 if (!old_lpm && sch->lpm)
 427                         device_trigger_reprobe(sch);
 428                 else if (sch->driver && sch->driver->verify)
 429                         sch->driver->verify(&sch->dev);
 430
 431                 spin_unlock_irq(&sch->lock);
 432                 put_device(&sch->dev);
 433                 if (fla_mask != 0)
 434                         break;
 435         }
 436         return rc;
 437 }
 438
 439 static int
 440 __get_chpid_from_lir(void *data)
 441 {
 442         struct lir {
 443                 u8  iq;
 444                 u8  ic;
 445                 u16 sci;
 446                 /* incident-node descriptor */
 447                 u32 indesc[28];
 448                 /* attached-node descriptor */
 449                 u32 andesc[28];
 450                 /* incident-specific information */
 451                 u32 isinfo[28];
 452         } *lir;
 453
 454         lir = (struct lir*) data;
 455         if (!(lir->iq&0x80))
 456                 /* NULL link incident record */
 457                 return -EINVAL;
 458         if (!(lir->indesc[0]&0xc0000000))
 459                 /* node descriptor not valid */
 460                 return -EINVAL;
 461         if (!(lir->indesc[0]&0x10000000))
 462                 /* don't handle device-type nodes - FIXME */
 463                 return -EINVAL;
 464         /* Byte 3 contains the chpid. Could also be CTCA, but we don't care */
 465
 466         return (u16) (lir->indesc[0]&0x000000ff);
 467 }
 468
 469 int
 470 chsc_process_crw(void)
 471 {
 472         int chpid, ret;
 473         struct {
 474                 struct chsc_header request;
 475                 u32 reserved1;
 476                 u32 reserved2;
 477                 u32 reserved3;
 478                 struct chsc_header response;
 479                 u32 reserved4;
 480                 u8  flags;
 481                 u8  vf;         /* validity flags */
 482                 u8  rs;         /* reporting source */
 483                 u8  cc;         /* content code */
 484                 u16 fla;        /* full link address */
 485                 u16 rsid;       /* reporting source id */
 486                 u32 reserved5;
 487                 u32 reserved6;
 488                 u32 ccdf[96];   /* content-code dependent field */
 489                 /* ccdf has to be big enough for a link-incident record */
 490         } *sei_area;
 491
 492         if (!sei_page)
 493                 return 0;
 494         /*
 495          * build the chsc request block for store event information
 496          * and do the call
 497          * This function is only called by the machine check handler thread,
 498          * so we don't need locking for the sei_page.
 499          */
 500         sei_area = sei_page;
 501
 502         CIO_TRACE_EVENT( 2, "prcss");
 503         ret = 0;
 504         do {
 505                 int ccode, status;
 506                 memset(sei_area, 0, sizeof(*sei_area));
 507
 508                 sei_area->request = (struct chsc_header) {
 509                         .length = 0x0010,
 510                         .code   = 0x000e,
 511                 };
 512
 513                 ccode = chsc(sei_area);
 514                 if (ccode > 0)
 515                         return 0;
 516
 517                 switch (sei_area->response.code) {
 518                         /* for debug purposes, check for problems */
 519                 case 0x0001:
 520                         CIO_CRW_EVENT(4, "chsc_process_crw: event information "
 521                                         "successfully stored\n");
 522                         break; /* everything ok */
 523                 case 0x0002:
 524                         CIO_CRW_EVENT(2,
 525                                       "chsc_process_crw: invalid command!\n");
 526                         return 0;
 527                 case 0x0003:
 528                         CIO_CRW_EVENT(2, "chsc_process_crw: error in chsc "
 529                                       "request block!\n");
 530                         return 0;
 531                 case 0x0005:
 532                         CIO_CRW_EVENT(2, "chsc_process_crw: no event "
 533                                       "information stored\n");
 534                         return 0;
 535                 default:
 536                         CIO_CRW_EVENT(2, "chsc_process_crw: chsc response %d\n",
 537                                       sei_area->response.code);
 538                         return 0;
 539                 }
 540
 541                 /* Check if we might have lost some information. */
 542                 if (sei_area->flags & 0x40)
 543                         CIO_CRW_EVENT(2, "chsc_process_crw: Event information "
 544                                        "has been lost due to overflow!\n");
 545
 546                 if (sei_area->rs != 4) {
 547                         CIO_CRW_EVENT(2, "chsc_process_crw: reporting source "
 548                                       "(%04X) isn't a chpid!\n",
 549                                       sei_area->rsid);
 550                         continue;
 551                 }
 552
 553                 /* which kind of information was stored? */
 554                 switch (sei_area->cc) {
 555                 case 1: /* link incident*/
 556                         CIO_CRW_EVENT(4, "chsc_process_crw: "
 557                                       "channel subsystem reports link incident,"
 558                                       " reporting source is chpid %x\n",
 559                                       sei_area->rsid);
 560                         chpid = __get_chpid_from_lir(sei_area->ccdf);
 561                         if (chpid < 0)
 562                                 CIO_CRW_EVENT(4, "%s: Invalid LIR, skipping\n",
 563                                               __FUNCTION__);
 564                         else
 565                                 s390_set_chpid_offline(chpid);
 566                         break;
 567
 568                 case 2: /* i/o resource accessibiliy */
 569                         CIO_CRW_EVENT(4, "chsc_process_crw: "
 570                                       "channel subsystem reports some I/O "
 571                                       "devices may have become accessible\n");
 572                         pr_debug("Data received after sei: \n");
 573                         pr_debug("Validity flags: %x\n", sei_area->vf);
 574
 575                         /* allocate a new channel path structure, if needed */
 576                         status = get_chp_status(sei_area->rsid);
 577                         if (status < 0)
 578                                 new_channel_path(sei_area->rsid);
 579                         else if (!status)
 580                                 return 0;
 581                         if ((sei_area->vf & 0x80) == 0) {
 582                                 pr_debug("chpid: %x\n", sei_area->rsid);
 583                                 ret = s390_process_res_acc(sei_area->rsid,
 584                                                            0, 0);
 585                         } else if ((sei_area->vf & 0xc0) == 0x80) {
 586                                 pr_debug("chpid: %x link addr: %x\n",
 587                                          sei_area->rsid, sei_area->fla);
 588                                 ret = s390_process_res_acc(sei_area->rsid,
 589                                                            sei_area->fla,
 590                                                            0xff00);
 591                         } else if ((sei_area->vf & 0xc0) == 0xc0) {
 592                                 pr_debug("chpid: %x full link addr: %x\n",
 593                                          sei_area->rsid, sei_area->fla);
 594                                 ret = s390_process_res_acc(sei_area->rsid,
 595                                                            sei_area->fla,
 596                                                            0xffff);
 597                         }
 598                         pr_debug("\n");
 599
 600                         break;
 601
 602                 default: /* other stuff */
 603                         CIO_CRW_EVENT(4, "chsc_process_crw: event %d\n",
 604                                       sei_area->cc);
 605                         break;
 606                 }
 607         } while (sei_area->flags & 0x80);
 608         return ret;
 609 }
 610
 611 static int
 612 chp_add(int chpid)
 613 {
 614         struct subchannel *sch;
 615         int irq, ret, rc;
 616         char dbf_txt[15];
 617
 618         if (!get_chp_status(chpid))
 619                 return 0; /* no need to do the rest */
 620
 621         sprintf(dbf_txt, "cadd%x", chpid);
 622         CIO_TRACE_EVENT(2, dbf_txt);
 623
 624         rc = 0;
 625         for (irq = 0; irq < __MAX_SUBCHANNELS; irq++) {
 626                 int i;
 627
 628                 sch = get_subchannel_by_schid(irq);
 629                 if (!sch) {
 630                         struct schib schib;
 631
 632                         if (stsch(irq, &schib)) {
 633                                 /* We're through */
 634                                 if (need_rescan)
 635                                         rc = -EAGAIN;
 636                                 break;
 637                         }
 638                         if (need_rescan) {
 639                                 rc = -EAGAIN;
 640                                 continue;
 641                         }
 642                         /* Put it on the slow path. */
 643                         ret = css_enqueue_subchannel_slow(irq);
 644                         if (ret) {
 645                                 css_clear_subchannel_slow_list();
 646                                 need_rescan = 1;
 647                         }
 648                         rc = -EAGAIN;
 649                         continue;
 650                 }
 651
 652                 spin_lock(&sch->lock);
 653                 for (i=0; i<8; i++)
 654                         if (sch->schib.pmcw.chpid[i] == chpid) {
 655                                 if (stsch(sch->irq, &sch->schib) != 0) {
 656                                         /* Endgame. */
 657                                         spin_unlock(&sch->lock);
 658                                         return rc;
 659                                 }
 660                                 break;
 661                         }
 662                 if (i==8) {
 663                         spin_unlock(&sch->lock);
 664                         return rc;
 665                 }
 666                 sch->lpm = ((sch->schib.pmcw.pim &
 667                              sch->schib.pmcw.pam &
 668                              sch->schib.pmcw.pom)
 669                             | 0x80 >> i) & sch->opm;
 670
 671                 if (sch->driver && sch->driver->verify)
 672                         sch->driver->verify(&sch->dev);
 673
 674                 spin_unlock(&sch->lock);
 675                 put_device(&sch->dev);
 676         }
 677         return rc;
 678 }
 679
 680 /*
 681  * Handling of crw machine checks with channel path source.
 682  */
 683 int
 684 chp_process_crw(int chpid, int on)
 685 {
 686         if (on == 0) {
 687                 /* Path has gone. We use the link incident routine.*/
 688                 s390_set_chpid_offline(chpid);
 689                 return 0; /* De-register is async anyway. */
 690         }
 691         /*
 692          * Path has come. Allocate a new channel path structure,
 693          * if needed.
 694          */
 695         if (get_chp_status(chpid) < 0)
 696                 new_channel_path(chpid);
 697         /* Avoid the extra overhead in process_rec_acc. */
 698         return chp_add(chpid);
 699 }
 700
 701 static inline int
 702 __check_for_io_and_kill(struct subchannel *sch, int index)
 703 {
 704         int cc;
 705
 706         if (!device_is_online(sch))
 707                 /* cio could be doing I/O. */
 708                 return 0;
 709         cc = stsch(sch->irq, &sch->schib);
 710         if (cc)
 711                 return 0;
 712         if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index)) {
 713                 device_set_waiting(sch);
 714                 return 1;
 715         }
 716         return 0;
 717 }
 718
 719 static inline void
 720 __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
 721 {
 722         int chp, old_lpm;
 723         unsigned long flags;
 724
 725         if (!sch->ssd_info.valid)
 726                 return;
 727
 728         spin_lock_irqsave(&sch->lock, flags);
 729         old_lpm = sch->lpm;
 730         for (chp = 0; chp < 8; chp++) {
 731                 if (sch->ssd_info.chpid[chp] != chpid)
 732                         continue;
 733
 734                 if (on) {
 735                         sch->opm |= (0x80 >> chp);
 736                         sch->lpm |= (0x80 >> chp);
 737                         if (!old_lpm)
 738                                 device_trigger_reprobe(sch);
 739                         else if (sch->driver && sch->driver->verify)
 740                                 sch->driver->verify(&sch->dev);
 741                 } else {
 742                         sch->opm &= ~(0x80 >> chp);
 743                         sch->lpm &= ~(0x80 >> chp);
 744                         /*
 745                          * Give running I/O a grace period in which it
 746                          * can successfully terminate, even using the
 747                          * just varied off path. Then kill it.
 748                          */
 749                         if (!__check_for_io_and_kill(sch, chp) && !sch->lpm) {
 750                                 if (css_enqueue_subchannel_slow(sch->irq)) {
 751                                         css_clear_subchannel_slow_list();
 752                                         need_rescan = 1;
 753                                 }
 754                         } else if (sch->driver && sch->driver->verify)
 755                                 sch->driver->verify(&sch->dev);
 756                 }
 757                 break;
 758         }
 759         spin_unlock_irqrestore(&sch->lock, flags);
 760 }
 761
 762 static int
 763 s390_subchannel_vary_chpid_off(struct device *dev, void *data)
 764 {
 765         struct subchannel *sch;
 766         __u8 *chpid;
 767
 768         sch = to_subchannel(dev);
 769         chpid = data;
 770
 771         __s390_subchannel_vary_chpid(sch, *chpid, 0);
 772         return 0;
 773 }
 774
 775 static int
 776 s390_subchannel_vary_chpid_on(struct device *dev, void *data)
 777 {
 778         struct subchannel *sch;
 779         __u8 *chpid;
 780
 781         sch = to_subchannel(dev);
 782         chpid = data;
 783
 784         __s390_subchannel_vary_chpid(sch, *chpid, 1);
 785         return 0;
 786 }
 787
 788 /*
 789  * Function: s390_vary_chpid
 790  * Varies the specified chpid online or offline
 791  */
 792 static int
 793 s390_vary_chpid( __u8 chpid, int on)
 794 {
 795         char dbf_text[15];
 796         int status, irq, ret;
 797         struct subchannel *sch;
 798
 799         sprintf(dbf_text, on?"varyon%x":"varyoff%x", chpid);
 800         CIO_TRACE_EVENT( 2, dbf_text);
 801
 802         status = get_chp_status(chpid);
 803         if (status < 0) {
 804                 printk(KERN_ERR "Can't vary unknown chpid %02X\n", chpid);
 805                 return -EINVAL;
 806         }
 807
 808         if (!on && !status) {
 809                 printk(KERN_ERR "chpid %x is already offline\n", chpid);
 810                 return -EINVAL;
 811         }
 812
 813         set_chp_logically_online(chpid, on);
 814
 815         /*
 816          * Redo PathVerification on the devices the chpid connects to
 817          */
 818
 819         bus_for_each_dev(&css_bus_type, NULL, &chpid, on ?
 820                          s390_subchannel_vary_chpid_on :
 821                          s390_subchannel_vary_chpid_off);
 822         if (!on)
 823                 goto out;
 824         /* Scan for new devices on varied on path. */
 825         for (irq = 0; irq < __MAX_SUBCHANNELS; irq++) {
 826                 struct schib schib;
 827
 828                 if (need_rescan)
 829                         break;
 830                 sch = get_subchannel_by_schid(irq);
 831                 if (sch) {
 832                         put_device(&sch->dev);
 833                         continue;
 834                 }
 835                 if (stsch(irq, &schib))
 836                         /* We're through */
 837                         break;
 838                 /* Put it on the slow path. */
 839                 ret = css_enqueue_subchannel_slow(irq);
 840                 if (ret) {
 841                         css_clear_subchannel_slow_list();
 842                         need_rescan = 1;
 843                 }
 844         }
 845 out:
 846         if (need_rescan || css_slow_subchannels_exist())
 847                 queue_work(slow_path_wq, &slow_path_work);
 848         return 0;
 849 }
 850
 851 /*
 852  * Files for the channel path entries.
 853  */
 854 static ssize_t
 855 chp_status_show(struct device *dev, char *buf)
 856 {
 857         struct channel_path *chp = container_of(dev, struct channel_path, dev);
 858
 859         if (!chp)
 860                 return 0;
 861         return (get_chp_status(chp->id) ? sprintf(buf, "online\n") :
 862                 sprintf(buf, "offline\n"));
 863 }
 864
 865 static ssize_t
 866 chp_status_write(struct device *dev, const char *buf, size_t count)
 867 {
 868         struct channel_path *cp = container_of(dev, struct channel_path, dev);
 869         char cmd[10];
 870         int num_args;
 871         int error;
 872
 873         num_args = sscanf(buf, "%5s", cmd);
 874         if (!num_args)
 875                 return count;
 876
 877         if (!strnicmp(cmd, "on", 2))
 878                 error = s390_vary_chpid(cp->id, 1);
 879         else if (!strnicmp(cmd, "off", 3))
 880                 error = s390_vary_chpid(cp->id, 0);
 881         else
 882                 error = -EINVAL;
 883
 884         return error < 0 ? error : count;
 885
 886 }
 887
 888 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
 889
 890 static ssize_t
 891 chp_type_show(struct device *dev, char *buf)
 892 {
 893         struct channel_path *chp = container_of(dev, struct channel_path, dev);
 894
 895         if (!chp)
 896                 return 0;
 897         return sprintf(buf, "%x\n", chp->desc.desc);
 898 }
 899
 900 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
 901
 902 static struct attribute * chp_attrs[] = {
 903         &dev_attr_status.attr,
 904         &dev_attr_type.attr,
 905         NULL,
 906 };
 907
 908 static struct attribute_group chp_attr_group = {
 909         .attrs = chp_attrs,
 910 };
 911
 912 static void
 913 chp_release(struct device *dev)
 914 {
 915         struct channel_path *cp;
 916
 917         cp = container_of(dev, struct channel_path, dev);
 918         kfree(cp);
 919 }
 920
 921 static int
 922 chsc_determine_channel_path_description(int chpid,
 923                                         struct channel_path_desc *desc)
 924 {
 925         int ccode, ret;
 926
 927         struct {
 928                 struct chsc_header request;
 929                 u32 : 24;
 930                 u32 first_chpid : 8;
 931                 u32 : 24;
 932                 u32 last_chpid : 8;
 933                 u32 zeroes1;
 934                 struct chsc_header response;
 935                 u32 zeroes2;
 936                 struct channel_path_desc desc;
 937         } *scpd_area;
 938
 939         scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
 940         if (!scpd_area)
 941                 return -ENOMEM;
 942
 943         scpd_area->request = (struct chsc_header) {
 944                 .length = 0x0010,
 945                 .code   = 0x0002,
 946         };
 947
 948         scpd_area->first_chpid = chpid;
 949         scpd_area->last_chpid = chpid;
 950
 951         ccode = chsc(scpd_area);
 952         if (ccode > 0) {
 953                 ret = (ccode == 3) ? -ENODEV : -EBUSY;
 954                 goto out;
 955         }
 956
 957         switch (scpd_area->response.code) {
 958         case 0x0001: /* Success. */
 959                 memcpy(desc, &scpd_area->desc,
 960                        sizeof(struct channel_path_desc));
 961                 ret = 0;
 962                 break;
 963         case 0x0003: /* Invalid block. */
 964         case 0x0007: /* Invalid format. */
 965         case 0x0008: /* Other invalid block. */
 966                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
 967                 ret = -EINVAL;
 968                 break;
 969         case 0x0004: /* Command not provided in model. */
 970                 CIO_CRW_EVENT(2, "Model does not provide scpd\n");
 971                 ret = -EOPNOTSUPP;
 972                 break;
 973         default:
 974                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
 975                               scpd_area->response.code);
 976                 ret = -EIO;
 977         }
 978 out:
 979         free_page((unsigned long)scpd_area);
 980         return ret;
 981 }
 982
 983 /*
 984  * Entries for chpids on the system bus.
 985  * This replaces /proc/chpids.
 986  */
 987 static int
 988 new_channel_path(int chpid)
 989 {
 990         struct channel_path *chp;
 991         int ret;
 992
 993         chp = kmalloc(sizeof(struct channel_path), GFP_KERNEL);
 994         if (!chp)
 995                 return -ENOMEM;
 996         memset(chp, 0, sizeof(struct channel_path));
 997
 998         /* fill in status, etc. */
 999         chp->id = chpid;
1000         chp->state = 1;
1001         chp->dev = (struct device) {
1002                 .parent  = &css_bus_device,
1003                 .release = chp_release,
1004         };
1005         snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp0.%x", chpid);
1006
1007         /* Obtain channel path description and fill it in. */
1008         ret = chsc_determine_channel_path_description(chpid, &chp->desc);
1009         if (ret)
1010                 goto out_free;
1011
1012         /* make it known to the system */
1013         ret = device_register(&chp->dev);
1014         if (ret) {
1015                 printk(KERN_WARNING "%s: could not register %02x\n",
1016                        __func__, chpid);
1017                 goto out_free;
1018         }
1019         ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
1020         if (ret) {
1021                 device_unregister(&chp->dev);
1022                 goto out_free;
1023         } else
1024                 chps[chpid] = chp;
1025         return ret;
1026 out_free:
1027         kfree(chp);
1028         return ret;
1029 }
1030
1031 void *
1032 chsc_get_chp_desc(struct subchannel *sch, int chp_no)
1033 {
1034         struct channel_path *chp;
1035         struct channel_path_desc *desc;
1036
1037         chp = chps[sch->schib.pmcw.chpid[chp_no]];
1038         if (!chp)
1039                 return NULL;
1040         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
1041         if (!desc)
1042                 return NULL;
1043         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
1044         return desc;
1045 }
1046
1047
1048 static int __init
1049 chsc_alloc_sei_area(void)
1050 {
1051         sei_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1052         if (!sei_page)
1053                 printk(KERN_WARNING"Can't allocate page for processing of " \
1054                        "chsc machine checks!\n");
1055         return (sei_page ? 0 : -ENOMEM);
1056 }
1057
1058 subsys_initcall(chsc_alloc_sei_area);
1059
1060 struct css_general_char css_general_characteristics;
1061 struct css_chsc_char css_chsc_characteristics;
1062
1063 int __init
1064 chsc_determine_css_characteristics(void)
1065 {
1066         int result;
1067         struct {
1068                 struct chsc_header request;
1069                 u32 reserved1;
1070                 u32 reserved2;
1071                 u32 reserved3;
1072                 struct chsc_header response;
1073                 u32 reserved4;
1074                 u32 general_char[510];
1075                 u32 chsc_char[518];
1076         } *scsc_area;
1077
1078         scsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1079         if (!scsc_area) {
1080                 printk(KERN_WARNING"cio: Was not able to determine available" \
1081                        "CHSCs due to no memory.\n");
1082                 return -ENOMEM;
1083         }
1084
1085         scsc_area->request = (struct chsc_header) {
1086                 .length = 0x0010,
1087                 .code   = 0x0010,
1088         };
1089
1090         result = chsc(scsc_area);
1091         if (result) {
1092                 printk(KERN_WARNING"cio: Was not able to determine " \
1093                        "available CHSCs, cc=%i.\n", result);
1094                 result = -EIO;
1095                 goto exit;
1096         }
1097
1098         if (scsc_area->response.code != 1) {
1099                 printk(KERN_WARNING"cio: Was not able to determine " \
1100                        "available CHSCs.\n");
1101                 result = -EIO;
1102                 goto exit;
1103         }
1104         memcpy(&css_general_characteristics, scsc_area->general_char,
1105                sizeof(css_general_characteristics));
1106         memcpy(&css_chsc_characteristics, scsc_area->chsc_char,
1107                sizeof(css_chsc_characteristics));
1108 exit:
1109         free_page ((unsigned long) scsc_area);
1110         return result;
1111 }
1112
1113 EXPORT_SYMBOL_GPL(css_general_characteristics);
1114 EXPORT_SYMBOL_GPL(css_chsc_characteristics);