drivers/s390/cio/chsc.c

   1 /*
   2  *  drivers/s390/cio/chsc.c
   3  *   S/390 common I/O routines -- channel subsystem call
   4  *
   5  *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
   6  *                            IBM Corporation
   7  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
   8  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   9  *               Arnd Bergmann (arndb@de.ibm.com)
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include <linux/init.h>
  15 #include <linux/device.h>
  16
  17 #include <asm/cio.h>
  18
  19 #include "css.h"
  20 #include "cio.h"
  21 #include "cio_debug.h"
  22 #include "ioasm.h"
  23 #include "chsc.h"
  24
  25 static void *sei_page;
  26
  27 static int new_channel_path(int chpid);
  28
  29 static inline void
  30 set_chp_logically_online(int chp, int onoff)
  31 {
  32         css[0]->chps[chp]->state = onoff;
  33 }
  34
  35 static int
  36 get_chp_status(int chp)
  37 {
  38         return (css[0]->chps[chp] ? css[0]->chps[chp]->state : -ENODEV);
  39 }
  40
  41 void
  42 chsc_validate_chpids(struct subchannel *sch)
  43 {
  44         int mask, chp;
  45
  46         for (chp = 0; chp <= 7; chp++) {
  47                 mask = 0x80 >> chp;
  48                 if (!get_chp_status(sch->schib.pmcw.chpid[chp]))
  49                         /* disable using this path */
  50                         sch->opm &= ~mask;
  51         }
  52 }
  53
  54 void
  55 chpid_is_actually_online(int chp)
  56 {
  57         int state;
  58
  59         state = get_chp_status(chp);
  60         if (state < 0) {
  61                 need_rescan = 1;
  62                 queue_work(slow_path_wq, &slow_path_work);
  63         } else
  64                 WARN_ON(!state);
  65 }
  66
  67 /* FIXME: this is _always_ called for every subchannel. shouldn't we
  68  *        process more than one at a time? */
  69 static int
  70 chsc_get_sch_desc_irq(struct subchannel *sch, void *page)
  71 {
  72         int ccode, j;
  73
  74         struct {
  75                 struct chsc_header request;
  76                 u16 reserved1a:10;
  77                 u16 ssid:2;
  78                 u16 reserved1b:4;
  79                 u16 f_sch;        /* first subchannel */
  80                 u16 reserved2;
  81                 u16 l_sch;        /* last subchannel */
  82                 u32 reserved3;
  83                 struct chsc_header response;
  84                 u32 reserved4;
  85                 u8 sch_valid : 1;
  86                 u8 dev_valid : 1;
  87                 u8 st        : 3; /* subchannel type */
  88                 u8 zeroes    : 3;
  89                 u8  unit_addr;    /* unit address */
  90                 u16 devno;        /* device number */
  91                 u8 path_mask;
  92                 u8 fla_valid_mask;
  93                 u16 sch;          /* subchannel */
  94                 u8 chpid[8];      /* chpids 0-7 */
  95                 u16 fla[8];       /* full link addresses 0-7 */
  96         } *ssd_area;
  97
  98         ssd_area = page;
  99
 100         ssd_area->request.length = 0x0010;
 101         ssd_area->request.code = 0x0004;
 102
 103         ssd_area->ssid = sch->schid.ssid;
 104         ssd_area->f_sch = sch->schid.sch_no;
 105         ssd_area->l_sch = sch->schid.sch_no;
 106
 107         ccode = chsc(ssd_area);
 108         if (ccode > 0) {
 109                 pr_debug("chsc returned with ccode = %d\n", ccode);
 110                 return (ccode == 3) ? -ENODEV : -EBUSY;
 111         }
 112
 113         switch (ssd_area->response.code) {
 114         case 0x0001: /* everything ok */
 115                 break;
 116         case 0x0002:
 117                 CIO_CRW_EVENT(2, "Invalid command!\n");
 118                 return -EINVAL;
 119         case 0x0003:
 120                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
 121                 return -EINVAL;
 122         case 0x0004:
 123                 CIO_CRW_EVENT(2, "Model does not provide ssd\n");
 124                 return -EOPNOTSUPP;
 125         default:
 126                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
 127                               ssd_area->response.code);
 128                 return -EIO;
 129         }
 130
 131         /*
 132          * ssd_area->st stores the type of the detected
 133          * subchannel, with the following definitions:
 134          *
 135          * 0: I/O subchannel:     All fields have meaning
 136          * 1: CHSC subchannel:    Only sch_val, st and sch
 137          *                        have meaning
 138          * 2: Message subchannel: All fields except unit_addr
 139          *                        have meaning
 140          * 3: ADM subchannel:     Only sch_val, st and sch
 141          *                        have meaning
 142          *
 143          * Other types are currently undefined.
 144          */
 145         if (ssd_area->st > 3) { /* uhm, that looks strange... */
 146                 CIO_CRW_EVENT(0, "Strange subchannel type %d"
 147                               " for sch 0.%x.%04x\n", ssd_area->st,
 148                               sch->schid.ssid, sch->schid.sch_no);
 149                 /*
 150                  * There may have been a new subchannel type defined in the
 151                  * time since this code was written; since we don't know which
 152                  * fields have meaning and what to do with it we just jump out
 153                  */
 154                 return 0;
 155         } else {
 156                 const char *type[4] = {"I/O", "chsc", "message", "ADM"};
 157                 CIO_CRW_EVENT(6, "ssd: sch 0.%x.%04x is %s subchannel\n",
 158                               sch->schid.ssid, sch->schid.sch_no,
 159                               type[ssd_area->st]);
 160
 161                 sch->ssd_info.valid = 1;
 162                 sch->ssd_info.type = ssd_area->st;
 163         }
 164
 165         if (ssd_area->st == 0 || ssd_area->st == 2) {
 166                 for (j = 0; j < 8; j++) {
 167                         if (!((0x80 >> j) & ssd_area->path_mask &
 168                               ssd_area->fla_valid_mask))
 169                                 continue;
 170                         sch->ssd_info.chpid[j] = ssd_area->chpid[j];
 171                         sch->ssd_info.fla[j]   = ssd_area->fla[j];
 172                 }
 173         }
 174         return 0;
 175 }
 176
 177 int
 178 css_get_ssd_info(struct subchannel *sch)
 179 {
 180         int ret;
 181         void *page;
 182
 183         page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
 184         if (!page)
 185                 return -ENOMEM;
 186         spin_lock_irq(sch->lock);
 187         ret = chsc_get_sch_desc_irq(sch, page);
 188         if (ret) {
 189                 static int cio_chsc_err_msg;
 190
 191                 if (!cio_chsc_err_msg) {
 192                         printk(KERN_ERR
 193                                "chsc_get_sch_descriptions:"
 194                                " Error %d while doing chsc; "
 195                                "processing some machine checks may "
 196                                "not work\n", ret);
 197                         cio_chsc_err_msg = 1;
 198                 }
 199         }
 200         spin_unlock_irq(sch->lock);
 201         free_page((unsigned long)page);
 202         if (!ret) {
 203                 int j, chpid, mask;
 204                 /* Allocate channel path structures, if needed. */
 205                 for (j = 0; j < 8; j++) {
 206                         mask = 0x80 >> j;
 207                         chpid = sch->ssd_info.chpid[j];
 208                         if ((sch->schib.pmcw.pim & mask) &&
 209                             (get_chp_status(chpid) < 0))
 210                             new_channel_path(chpid);
 211                 }
 212         }
 213         return ret;
 214 }
 215
 216 static int
 217 s390_subchannel_remove_chpid(struct device *dev, void *data)
 218 {
 219         int j;
 220         int mask;
 221         struct subchannel *sch;
 222         struct channel_path *chpid;
 223         struct schib schib;
 224
 225         sch = to_subchannel(dev);
 226         chpid = data;
 227         for (j = 0; j < 8; j++) {
 228                 mask = 0x80 >> j;
 229                 if ((sch->schib.pmcw.pim & mask) &&
 230                     (sch->schib.pmcw.chpid[j] == chpid->id))
 231                         break;
 232         }
 233         if (j >= 8)
 234                 return 0;
 235
 236         spin_lock_irq(sch->lock);
 237
 238         stsch(sch->schid, &schib);
 239         if (!schib.pmcw.dnv)
 240                 goto out_unreg;
 241         memcpy(&sch->schib, &schib, sizeof(struct schib));
 242         /* Check for single path devices. */
 243         if (sch->schib.pmcw.pim == 0x80)
 244                 goto out_unreg;
 245
 246         if ((sch->schib.scsw.actl & SCSW_ACTL_DEVACT) &&
 247             (sch->schib.scsw.actl & SCSW_ACTL_SCHACT) &&
 248             (sch->schib.pmcw.lpum == mask)) {
 249                 int cc;
 250
 251                 cc = cio_clear(sch);
 252                 if (cc == -ENODEV)
 253                         goto out_unreg;
 254                 /* Request retry of internal operation. */
 255                 device_set_intretry(sch);
 256                 /* Call handler. */
 257                 if (sch->driver && sch->driver->termination)
 258                         sch->driver->termination(&sch->dev);
 259                 goto out_unlock;
 260         }
 261
 262         /* trigger path verification. */
 263         if (sch->driver && sch->driver->verify)
 264                 sch->driver->verify(&sch->dev);
 265         else if (sch->lpm == mask)
 266                 goto out_unreg;
 267 out_unlock:
 268         spin_unlock_irq(sch->lock);
 269         return 0;
 270 out_unreg:
 271         spin_unlock_irq(sch->lock);
 272         sch->lpm = 0;
 273         if (css_enqueue_subchannel_slow(sch->schid)) {
 274                 css_clear_subchannel_slow_list();
 275                 need_rescan = 1;
 276         }
 277         return 0;
 278 }
 279
 280 static inline void
 281 s390_set_chpid_offline( __u8 chpid)
 282 {
 283         char dbf_txt[15];
 284         struct device *dev;
 285
 286         sprintf(dbf_txt, "chpr%x", chpid);
 287         CIO_TRACE_EVENT(2, dbf_txt);
 288
 289         if (get_chp_status(chpid) <= 0)
 290                 return;
 291         dev = get_device(&css[0]->chps[chpid]->dev);
 292         bus_for_each_dev(&css_bus_type, NULL, to_channelpath(dev),
 293                          s390_subchannel_remove_chpid);
 294
 295         if (need_rescan || css_slow_subchannels_exist())
 296                 queue_work(slow_path_wq, &slow_path_work);
 297         put_device(dev);
 298 }
 299
 300 struct res_acc_data {
 301         struct channel_path *chp;
 302         u32 fla_mask;
 303         u16 fla;
 304 };
 305
 306 static int
 307 s390_process_res_acc_sch(struct res_acc_data *res_data, struct subchannel *sch)
 308 {
 309         int found;
 310         int chp;
 311         int ccode;
 312
 313         found = 0;
 314         for (chp = 0; chp <= 7; chp++)
 315                 /*
 316                  * check if chpid is in information updated by ssd
 317                  */
 318                 if (sch->ssd_info.valid &&
 319                     sch->ssd_info.chpid[chp] == res_data->chp->id &&
 320                     (sch->ssd_info.fla[chp] & res_data->fla_mask)
 321                     == res_data->fla) {
 322                         found = 1;
 323                         break;
 324                 }
 325
 326         if (found == 0)
 327                 return 0;
 328
 329         /*
 330          * Do a stsch to update our subchannel structure with the
 331          * new path information and eventually check for logically
 332          * offline chpids.
 333          */
 334         ccode = stsch(sch->schid, &sch->schib);
 335         if (ccode > 0)
 336                 return 0;
 337
 338         return 0x80 >> chp;
 339 }
 340
 341 static inline int
 342 s390_process_res_acc_new_sch(struct subchannel_id schid)
 343 {
 344         struct schib schib;
 345         int ret;
 346         /*
 347          * We don't know the device yet, but since a path
 348          * may be available now to the device we'll have
 349          * to do recognition again.
 350          * Since we don't have any idea about which chpid
 351          * that beast may be on we'll have to do a stsch
 352          * on all devices, grr...
 353          */
 354         if (stsch_err(schid, &schib))
 355                 /* We're through */
 356                 return need_rescan ? -EAGAIN : -ENXIO;
 357
 358         /* Put it on the slow path. */
 359         ret = css_enqueue_subchannel_slow(schid);
 360         if (ret) {
 361                 css_clear_subchannel_slow_list();
 362                 need_rescan = 1;
 363                 return -EAGAIN;
 364         }
 365         return 0;
 366 }
 367
 368 static int
 369 __s390_process_res_acc(struct subchannel_id schid, void *data)
 370 {
 371         int chp_mask, old_lpm;
 372         struct res_acc_data *res_data;
 373         struct subchannel *sch;
 374
 375         res_data = data;
 376         sch = get_subchannel_by_schid(schid);
 377         if (!sch)
 378                 /* Check if a subchannel is newly available. */
 379                 return s390_process_res_acc_new_sch(schid);
 380
 381         spin_lock_irq(sch->lock);
 382
 383         chp_mask = s390_process_res_acc_sch(res_data, sch);
 384
 385         if (chp_mask == 0) {
 386                 spin_unlock_irq(sch->lock);
 387                 put_device(&sch->dev);
 388                 return 0;
 389         }
 390         old_lpm = sch->lpm;
 391         sch->lpm = ((sch->schib.pmcw.pim &
 392                      sch->schib.pmcw.pam &
 393                      sch->schib.pmcw.pom)
 394                     | chp_mask) & sch->opm;
 395         if (!old_lpm && sch->lpm)
 396                 device_trigger_reprobe(sch);
 397         else if (sch->driver && sch->driver->verify)
 398                 sch->driver->verify(&sch->dev);
 399
 400         spin_unlock_irq(sch->lock);
 401         put_device(&sch->dev);
 402         return 0;
 403 }
 404
 405
 406 static int
 407 s390_process_res_acc (struct res_acc_data *res_data)
 408 {
 409         int rc;
 410         char dbf_txt[15];
 411
 412         sprintf(dbf_txt, "accpr%x", res_data->chp->id);
 413         CIO_TRACE_EVENT( 2, dbf_txt);
 414         if (res_data->fla != 0) {
 415                 sprintf(dbf_txt, "fla%x", res_data->fla);
 416                 CIO_TRACE_EVENT( 2, dbf_txt);
 417         }
 418
 419         /*
 420          * I/O resources may have become accessible.
 421          * Scan through all subchannels that may be concerned and
 422          * do a validation on those.
 423          * The more information we have (info), the less scanning
 424          * will we have to do.
 425          */
 426         rc = for_each_subchannel(__s390_process_res_acc, res_data);
 427         if (css_slow_subchannels_exist())
 428                 rc = -EAGAIN;
 429         else if (rc != -EAGAIN)
 430                 rc = 0;
 431         return rc;
 432 }
 433
 434 static int
 435 __get_chpid_from_lir(void *data)
 436 {
 437         struct lir {
 438                 u8  iq;
 439                 u8  ic;
 440                 u16 sci;
 441                 /* incident-node descriptor */
 442                 u32 indesc[28];
 443                 /* attached-node descriptor */
 444                 u32 andesc[28];
 445                 /* incident-specific information */
 446                 u32 isinfo[28];
 447         } *lir;
 448
 449         lir = data;
 450         if (!(lir->iq&0x80))
 451                 /* NULL link incident record */
 452                 return -EINVAL;
 453         if (!(lir->indesc[0]&0xc0000000))
 454                 /* node descriptor not valid */
 455                 return -EINVAL;
 456         if (!(lir->indesc[0]&0x10000000))
 457                 /* don't handle device-type nodes - FIXME */
 458                 return -EINVAL;
 459         /* Byte 3 contains the chpid. Could also be CTCA, but we don't care */
 460
 461         return (u16) (lir->indesc[0]&0x000000ff);
 462 }
 463
 464 int
 465 chsc_process_crw(void)
 466 {
 467         int chpid, ret;
 468         struct res_acc_data res_data;
 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                 struct device *dev;
 503                 memset(sei_area, 0, sizeof(*sei_area));
 504                 memset(&res_data, 0, sizeof(struct res_acc_data));
 505                 sei_area->request.length = 0x0010;
 506                 sei_area->request.code = 0x000e;
 507
 508                 ccode = chsc(sei_area);
 509                 if (ccode > 0)
 510                         return 0;
 511
 512                 switch (sei_area->response.code) {
 513                         /* for debug purposes, check for problems */
 514                 case 0x0001:
 515                         CIO_CRW_EVENT(4, "chsc_process_crw: event information "
 516                                         "successfully stored\n");
 517                         break; /* everything ok */
 518                 case 0x0002:
 519                         CIO_CRW_EVENT(2,
 520                                       "chsc_process_crw: invalid command!\n");
 521                         return 0;
 522                 case 0x0003:
 523                         CIO_CRW_EVENT(2, "chsc_process_crw: error in chsc "
 524                                       "request block!\n");
 525                         return 0;
 526                 case 0x0005:
 527                         CIO_CRW_EVENT(2, "chsc_process_crw: no event "
 528                                       "information stored\n");
 529                         return 0;
 530                 default:
 531                         CIO_CRW_EVENT(2, "chsc_process_crw: chsc response %d\n",
 532                                       sei_area->response.code);
 533                         return 0;
 534                 }
 535
 536                 /* Check if we might have lost some information. */
 537                 if (sei_area->flags & 0x40)
 538                         CIO_CRW_EVENT(2, "chsc_process_crw: Event information "
 539                                        "has been lost due to overflow!\n");
 540
 541                 if (sei_area->rs != 4) {
 542                         CIO_CRW_EVENT(2, "chsc_process_crw: reporting source "
 543                                       "(%04X) isn't a chpid!\n",
 544                                       sei_area->rsid);
 545                         continue;
 546                 }
 547
 548                 /* which kind of information was stored? */
 549                 switch (sei_area->cc) {
 550                 case 1: /* link incident*/
 551                         CIO_CRW_EVENT(4, "chsc_process_crw: "
 552                                       "channel subsystem reports link incident,"
 553                                       " reporting source is chpid %x\n",
 554                                       sei_area->rsid);
 555                         chpid = __get_chpid_from_lir(sei_area->ccdf);
 556                         if (chpid < 0)
 557                                 CIO_CRW_EVENT(4, "%s: Invalid LIR, skipping\n",
 558                                               __FUNCTION__);
 559                         else
 560                                 s390_set_chpid_offline(chpid);
 561                         break;
 562
 563                 case 2: /* i/o resource accessibiliy */
 564                         CIO_CRW_EVENT(4, "chsc_process_crw: "
 565                                       "channel subsystem reports some I/O "
 566                                       "devices may have become accessible\n");
 567                         pr_debug("Data received after sei: \n");
 568                         pr_debug("Validity flags: %x\n", sei_area->vf);
 569
 570                         /* allocate a new channel path structure, if needed */
 571                         status = get_chp_status(sei_area->rsid);
 572                         if (status < 0)
 573                                 new_channel_path(sei_area->rsid);
 574                         else if (!status)
 575                                 break;
 576                         dev = get_device(&css[0]->chps[sei_area->rsid]->dev);
 577                         res_data.chp = to_channelpath(dev);
 578                         pr_debug("chpid: %x", sei_area->rsid);
 579                         if ((sei_area->vf & 0xc0) != 0) {
 580                                 res_data.fla = sei_area->fla;
 581                                 if ((sei_area->vf & 0xc0) == 0xc0) {
 582                                         pr_debug(" full link addr: %x",
 583                                                  sei_area->fla);
 584                                         res_data.fla_mask = 0xffff;
 585                                 } else {
 586                                         pr_debug(" link addr: %x",
 587                                                  sei_area->fla);
 588                                         res_data.fla_mask = 0xff00;
 589                                 }
 590                         }
 591                         ret = s390_process_res_acc(&res_data);
 592                         pr_debug("\n\n");
 593                         put_device(dev);
 594                         break;
 595
 596                 default: /* other stuff */
 597                         CIO_CRW_EVENT(4, "chsc_process_crw: event %d\n",
 598                                       sei_area->cc);
 599                         break;
 600                 }
 601         } while (sei_area->flags & 0x80);
 602         return ret;
 603 }
 604
 605 static inline int
 606 __chp_add_new_sch(struct subchannel_id schid)
 607 {
 608         struct schib schib;
 609         int ret;
 610
 611         if (stsch_err(schid, &schib))
 612                 /* We're through */
 613                 return need_rescan ? -EAGAIN : -ENXIO;
 614
 615         /* Put it on the slow path. */
 616         ret = css_enqueue_subchannel_slow(schid);
 617         if (ret) {
 618                 css_clear_subchannel_slow_list();
 619                 need_rescan = 1;
 620                 return -EAGAIN;
 621         }
 622         return 0;
 623 }
 624
 625
 626 static int
 627 __chp_add(struct subchannel_id schid, void *data)
 628 {
 629         int i, mask;
 630         struct channel_path *chp;
 631         struct subchannel *sch;
 632
 633         chp = data;
 634         sch = get_subchannel_by_schid(schid);
 635         if (!sch)
 636                 /* Check if the subchannel is now available. */
 637                 return __chp_add_new_sch(schid);
 638         spin_lock_irq(sch->lock);
 639         for (i=0; i<8; i++) {
 640                 mask = 0x80 >> i;
 641                 if ((sch->schib.pmcw.pim & mask) &&
 642                     (sch->schib.pmcw.chpid[i] == chp->id)) {
 643                         if (stsch(sch->schid, &sch->schib) != 0) {
 644                                 /* Endgame. */
 645                                 spin_unlock_irq(sch->lock);
 646                                 return -ENXIO;
 647                         }
 648                         break;
 649                 }
 650         }
 651         if (i==8) {
 652                 spin_unlock_irq(sch->lock);
 653                 return 0;
 654         }
 655         sch->lpm = ((sch->schib.pmcw.pim &
 656                      sch->schib.pmcw.pam &
 657                      sch->schib.pmcw.pom)
 658                     | mask) & sch->opm;
 659
 660         if (sch->driver && sch->driver->verify)
 661                 sch->driver->verify(&sch->dev);
 662
 663         spin_unlock_irq(sch->lock);
 664         put_device(&sch->dev);
 665         return 0;
 666 }
 667
 668 static int
 669 chp_add(int chpid)
 670 {
 671         int rc;
 672         char dbf_txt[15];
 673         struct device *dev;
 674
 675         if (!get_chp_status(chpid))
 676                 return 0; /* no need to do the rest */
 677
 678         sprintf(dbf_txt, "cadd%x", chpid);
 679         CIO_TRACE_EVENT(2, dbf_txt);
 680
 681         dev = get_device(&css[0]->chps[chpid]->dev);
 682         rc = for_each_subchannel(__chp_add, to_channelpath(dev));
 683         if (css_slow_subchannels_exist())
 684                 rc = -EAGAIN;
 685         if (rc != -EAGAIN)
 686                 rc = 0;
 687         put_device(dev);
 688         return rc;
 689 }
 690
 691 /*
 692  * Handling of crw machine checks with channel path source.
 693  */
 694 int
 695 chp_process_crw(int chpid, int on)
 696 {
 697         if (on == 0) {
 698                 /* Path has gone. We use the link incident routine.*/
 699                 s390_set_chpid_offline(chpid);
 700                 return 0; /* De-register is async anyway. */
 701         }
 702         /*
 703          * Path has come. Allocate a new channel path structure,
 704          * if needed.
 705          */
 706         if (get_chp_status(chpid) < 0)
 707                 new_channel_path(chpid);
 708         /* Avoid the extra overhead in process_rec_acc. */
 709         return chp_add(chpid);
 710 }
 711
 712 static inline int check_for_io_on_path(struct subchannel *sch, int index)
 713 {
 714         int cc;
 715
 716         cc = stsch(sch->schid, &sch->schib);
 717         if (cc)
 718                 return 0;
 719         if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index))
 720                 return 1;
 721         return 0;
 722 }
 723
 724 static void terminate_internal_io(struct subchannel *sch)
 725 {
 726         if (cio_clear(sch)) {
 727                 /* Recheck device in case clear failed. */
 728                 sch->lpm = 0;
 729                 if (device_trigger_verify(sch) != 0) {
 730                         if(css_enqueue_subchannel_slow(sch->schid)) {
 731                                 css_clear_subchannel_slow_list();
 732                                 need_rescan = 1;
 733                         }
 734                 }
 735                 return;
 736         }
 737         /* Request retry of internal operation. */
 738         device_set_intretry(sch);
 739         /* Call handler. */
 740         if (sch->driver && sch->driver->termination)
 741                 sch->driver->termination(&sch->dev);
 742 }
 743
 744 static inline void
 745 __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
 746 {
 747         int chp, old_lpm;
 748         unsigned long flags;
 749
 750         if (!sch->ssd_info.valid)
 751                 return;
 752
 753         spin_lock_irqsave(sch->lock, flags);
 754         old_lpm = sch->lpm;
 755         for (chp = 0; chp < 8; chp++) {
 756                 if (sch->ssd_info.chpid[chp] != chpid)
 757                         continue;
 758
 759                 if (on) {
 760                         sch->opm |= (0x80 >> chp);
 761                         sch->lpm |= (0x80 >> chp);
 762                         if (!old_lpm)
 763                                 device_trigger_reprobe(sch);
 764                         else if (sch->driver && sch->driver->verify)
 765                                 sch->driver->verify(&sch->dev);
 766                         break;
 767                 }
 768                 sch->opm &= ~(0x80 >> chp);
 769                 sch->lpm &= ~(0x80 >> chp);
 770                 if (check_for_io_on_path(sch, chp)) {
 771                         if (device_is_online(sch))
 772                                 /* Path verification is done after killing. */
 773                                 device_kill_io(sch);
 774                         else
 775                                 /* Kill and retry internal I/O. */
 776                                 terminate_internal_io(sch);
 777                 } else if (!sch->lpm) {
 778                         if (device_trigger_verify(sch) != 0) {
 779                                 if (css_enqueue_subchannel_slow(sch->schid)) {
 780                                         css_clear_subchannel_slow_list();
 781                                         need_rescan = 1;
 782                                 }
 783                         }
 784                 } else if (sch->driver && sch->driver->verify)
 785                         sch->driver->verify(&sch->dev);
 786                 break;
 787         }
 788         spin_unlock_irqrestore(sch->lock, flags);
 789 }
 790
 791 static int
 792 s390_subchannel_vary_chpid_off(struct device *dev, void *data)
 793 {
 794         struct subchannel *sch;
 795         __u8 *chpid;
 796
 797         sch = to_subchannel(dev);
 798         chpid = data;
 799
 800         __s390_subchannel_vary_chpid(sch, *chpid, 0);
 801         return 0;
 802 }
 803
 804 static int
 805 s390_subchannel_vary_chpid_on(struct device *dev, void *data)
 806 {
 807         struct subchannel *sch;
 808         __u8 *chpid;
 809
 810         sch = to_subchannel(dev);
 811         chpid = data;
 812
 813         __s390_subchannel_vary_chpid(sch, *chpid, 1);
 814         return 0;
 815 }
 816
 817 static int
 818 __s390_vary_chpid_on(struct subchannel_id schid, void *data)
 819 {
 820         struct schib schib;
 821         struct subchannel *sch;
 822
 823         sch = get_subchannel_by_schid(schid);
 824         if (sch) {
 825                 put_device(&sch->dev);
 826                 return 0;
 827         }
 828         if (stsch_err(schid, &schib))
 829                 /* We're through */
 830                 return -ENXIO;
 831         /* Put it on the slow path. */
 832         if (css_enqueue_subchannel_slow(schid)) {
 833                 css_clear_subchannel_slow_list();
 834                 need_rescan = 1;
 835                 return -EAGAIN;
 836         }
 837         return 0;
 838 }
 839
 840 /*
 841  * Function: s390_vary_chpid
 842  * Varies the specified chpid online or offline
 843  */
 844 static int
 845 s390_vary_chpid( __u8 chpid, int on)
 846 {
 847         char dbf_text[15];
 848         int status;
 849
 850         sprintf(dbf_text, on?"varyon%x":"varyoff%x", chpid);
 851         CIO_TRACE_EVENT( 2, dbf_text);
 852
 853         status = get_chp_status(chpid);
 854         if (status < 0) {
 855                 printk(KERN_ERR "Can't vary unknown chpid %02X\n", chpid);
 856                 return -EINVAL;
 857         }
 858
 859         if (!on && !status) {
 860                 printk(KERN_ERR "chpid %x is already offline\n", chpid);
 861                 return -EINVAL;
 862         }
 863
 864         set_chp_logically_online(chpid, on);
 865
 866         /*
 867          * Redo PathVerification on the devices the chpid connects to
 868          */
 869
 870         bus_for_each_dev(&css_bus_type, NULL, &chpid, on ?
 871                          s390_subchannel_vary_chpid_on :
 872                          s390_subchannel_vary_chpid_off);
 873         if (on)
 874                 /* Scan for new devices on varied on path. */
 875                 for_each_subchannel(__s390_vary_chpid_on, NULL);
 876         if (need_rescan || css_slow_subchannels_exist())
 877                 queue_work(slow_path_wq, &slow_path_work);
 878         return 0;
 879 }
 880
 881 /*
 882  * Channel measurement related functions
 883  */
 884 static ssize_t
 885 chp_measurement_chars_read(struct kobject *kobj, char *buf, loff_t off,
 886                            size_t count)
 887 {
 888         struct channel_path *chp;
 889         unsigned int size;
 890
 891         chp = to_channelpath(container_of(kobj, struct device, kobj));
 892         if (!chp->cmg_chars)
 893                 return 0;
 894
 895         size = sizeof(struct cmg_chars);
 896
 897         if (off > size)
 898                 return 0;
 899         if (off + count > size)
 900                 count = size - off;
 901         memcpy(buf, chp->cmg_chars + off, count);
 902         return count;
 903 }
 904
 905 static struct bin_attribute chp_measurement_chars_attr = {
 906         .attr = {
 907                 .name = "measurement_chars",
 908                 .mode = S_IRUSR,
 909                 .owner = THIS_MODULE,
 910         },
 911         .size = sizeof(struct cmg_chars),
 912         .read = chp_measurement_chars_read,
 913 };
 914
 915 static void
 916 chp_measurement_copy_block(struct cmg_entry *buf,
 917                            struct channel_subsystem *css, int chpid)
 918 {
 919         void *area;
 920         struct cmg_entry *entry, reference_buf;
 921         int idx;
 922
 923         if (chpid < 128) {
 924                 area = css->cub_addr1;
 925                 idx = chpid;
 926         } else {
 927                 area = css->cub_addr2;
 928                 idx = chpid - 128;
 929         }
 930         entry = area + (idx * sizeof(struct cmg_entry));
 931         do {
 932                 memcpy(buf, entry, sizeof(*entry));
 933                 memcpy(&reference_buf, entry, sizeof(*entry));
 934         } while (reference_buf.values[0] != buf->values[0]);
 935 }
 936
 937 static ssize_t
 938 chp_measurement_read(struct kobject *kobj, char *buf, loff_t off, size_t count)
 939 {
 940         struct channel_path *chp;
 941         struct channel_subsystem *css;
 942         unsigned int size;
 943
 944         chp = to_channelpath(container_of(kobj, struct device, kobj));
 945         css = to_css(chp->dev.parent);
 946
 947         size = sizeof(struct cmg_entry);
 948
 949         /* Only allow single reads. */
 950         if (off || count < size)
 951                 return 0;
 952         chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->id);
 953         count = size;
 954         return count;
 955 }
 956
 957 static struct bin_attribute chp_measurement_attr = {
 958         .attr = {
 959                 .name = "measurement",
 960                 .mode = S_IRUSR,
 961                 .owner = THIS_MODULE,
 962         },
 963         .size = sizeof(struct cmg_entry),
 964         .read = chp_measurement_read,
 965 };
 966
 967 static void
 968 chsc_remove_chp_cmg_attr(struct channel_path *chp)
 969 {
 970         device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
 971         device_remove_bin_file(&chp->dev, &chp_measurement_attr);
 972 }
 973
 974 static int
 975 chsc_add_chp_cmg_attr(struct channel_path *chp)
 976 {
 977         int ret;
 978
 979         ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr);
 980         if (ret)
 981                 return ret;
 982         ret = device_create_bin_file(&chp->dev, &chp_measurement_attr);
 983         if (ret)
 984                 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
 985         return ret;
 986 }
 987
 988 static void
 989 chsc_remove_cmg_attr(struct channel_subsystem *css)
 990 {
 991         int i;
 992
 993         for (i = 0; i <= __MAX_CHPID; i++) {
 994                 if (!css->chps[i])
 995                         continue;
 996                 chsc_remove_chp_cmg_attr(css->chps[i]);
 997         }
 998 }
 999
1000 static int
1001 chsc_add_cmg_attr(struct channel_subsystem *css)
1002 {
1003         int i, ret;
1004
1005         ret = 0;
1006         for (i = 0; i <= __MAX_CHPID; i++) {
1007                 if (!css->chps[i])
1008                         continue;
1009                 ret = chsc_add_chp_cmg_attr(css->chps[i]);
1010                 if (ret)
1011                         goto cleanup;
1012         }
1013         return ret;
1014 cleanup:
1015         for (--i; i >= 0; i--) {
1016                 if (!css->chps[i])
1017                         continue;
1018                 chsc_remove_chp_cmg_attr(css->chps[i]);
1019         }
1020         return ret;
1021 }
1022
1023
1024 static int
1025 __chsc_do_secm(struct channel_subsystem *css, int enable, void *page)
1026 {
1027         struct {
1028                 struct chsc_header request;
1029                 u32 operation_code : 2;
1030                 u32 : 30;
1031                 u32 key : 4;
1032                 u32 : 28;
1033                 u32 zeroes1;
1034                 u32 cub_addr1;
1035                 u32 zeroes2;
1036                 u32 cub_addr2;
1037                 u32 reserved[13];
1038                 struct chsc_header response;
1039                 u32 status : 8;
1040                 u32 : 4;
1041                 u32 fmt : 4;
1042                 u32 : 16;
1043         } *secm_area;
1044         int ret, ccode;
1045
1046         secm_area = page;
1047         secm_area->request.length = 0x0050;
1048         secm_area->request.code = 0x0016;
1049
1050         secm_area->key = PAGE_DEFAULT_KEY;
1051         secm_area->cub_addr1 = (u64)(unsigned long)css->cub_addr1;
1052         secm_area->cub_addr2 = (u64)(unsigned long)css->cub_addr2;
1053
1054         secm_area->operation_code = enable ? 0 : 1;
1055
1056         ccode = chsc(secm_area);
1057         if (ccode > 0)
1058                 return (ccode == 3) ? -ENODEV : -EBUSY;
1059
1060         switch (secm_area->response.code) {
1061         case 0x0001: /* Success. */
1062                 ret = 0;
1063                 break;
1064         case 0x0003: /* Invalid block. */
1065         case 0x0007: /* Invalid format. */
1066         case 0x0008: /* Other invalid block. */
1067                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1068                 ret = -EINVAL;
1069                 break;
1070         case 0x0004: /* Command not provided in model. */
1071                 CIO_CRW_EVENT(2, "Model does not provide secm\n");
1072                 ret = -EOPNOTSUPP;
1073                 break;
1074         case 0x0102: /* cub adresses incorrect */
1075                 CIO_CRW_EVENT(2, "Invalid addresses in chsc request block\n");
1076                 ret = -EINVAL;
1077                 break;
1078         case 0x0103: /* key error */
1079                 CIO_CRW_EVENT(2, "Access key error in secm\n");
1080                 ret = -EINVAL;
1081                 break;
1082         case 0x0105: /* error while starting */
1083                 CIO_CRW_EVENT(2, "Error while starting channel measurement\n");
1084                 ret = -EIO;
1085                 break;
1086         default:
1087                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1088                               secm_area->response.code);
1089                 ret = -EIO;
1090         }
1091         return ret;
1092 }
1093
1094 int
1095 chsc_secm(struct channel_subsystem *css, int enable)
1096 {
1097         void  *secm_area;
1098         int ret;
1099
1100         secm_area = (void *)get_zeroed_page(GFP_KERNEL |  GFP_DMA);
1101         if (!secm_area)
1102                 return -ENOMEM;
1103
1104         mutex_lock(&css->mutex);
1105         if (enable && !css->cm_enabled) {
1106                 css->cub_addr1 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1107                 css->cub_addr2 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1108                 if (!css->cub_addr1 || !css->cub_addr2) {
1109                         free_page((unsigned long)css->cub_addr1);
1110                         free_page((unsigned long)css->cub_addr2);
1111                         free_page((unsigned long)secm_area);
1112                         mutex_unlock(&css->mutex);
1113                         return -ENOMEM;
1114                 }
1115         }
1116         ret = __chsc_do_secm(css, enable, secm_area);
1117         if (!ret) {
1118                 css->cm_enabled = enable;
1119                 if (css->cm_enabled) {
1120                         ret = chsc_add_cmg_attr(css);
1121                         if (ret) {
1122                                 memset(secm_area, 0, PAGE_SIZE);
1123                                 __chsc_do_secm(css, 0, secm_area);
1124                                 css->cm_enabled = 0;
1125                         }
1126                 } else
1127                         chsc_remove_cmg_attr(css);
1128         }
1129         if (enable && !css->cm_enabled) {
1130                 free_page((unsigned long)css->cub_addr1);
1131                 free_page((unsigned long)css->cub_addr2);
1132         }
1133         mutex_unlock(&css->mutex);
1134         free_page((unsigned long)secm_area);
1135         return ret;
1136 }
1137
1138 /*
1139  * Files for the channel path entries.
1140  */
1141 static ssize_t
1142 chp_status_show(struct device *dev, struct device_attribute *attr, char *buf)
1143 {
1144         struct channel_path *chp = container_of(dev, struct channel_path, dev);
1145
1146         if (!chp)
1147                 return 0;
1148         return (get_chp_status(chp->id) ? sprintf(buf, "online\n") :
1149                 sprintf(buf, "offline\n"));
1150 }
1151
1152 static ssize_t
1153 chp_status_write(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
1154 {
1155         struct channel_path *cp = container_of(dev, struct channel_path, dev);
1156         char cmd[10];
1157         int num_args;
1158         int error;
1159
1160         num_args = sscanf(buf, "%5s", cmd);
1161         if (!num_args)
1162                 return count;
1163
1164         if (!strnicmp(cmd, "on", 2))
1165                 error = s390_vary_chpid(cp->id, 1);
1166         else if (!strnicmp(cmd, "off", 3))
1167                 error = s390_vary_chpid(cp->id, 0);
1168         else
1169                 error = -EINVAL;
1170
1171         return error < 0 ? error : count;
1172
1173 }
1174
1175 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
1176
1177 static ssize_t
1178 chp_type_show(struct device *dev, struct device_attribute *attr, char *buf)
1179 {
1180         struct channel_path *chp = container_of(dev, struct channel_path, dev);
1181
1182         if (!chp)
1183                 return 0;
1184         return sprintf(buf, "%x\n", chp->desc.desc);
1185 }
1186
1187 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
1188
1189 static ssize_t
1190 chp_cmg_show(struct device *dev, struct device_attribute *attr, char *buf)
1191 {
1192         struct channel_path *chp = to_channelpath(dev);
1193
1194         if (!chp)
1195                 return 0;
1196         if (chp->cmg == -1) /* channel measurements not available */
1197                 return sprintf(buf, "unknown\n");
1198         return sprintf(buf, "%x\n", chp->cmg);
1199 }
1200
1201 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
1202
1203 static ssize_t
1204 chp_shared_show(struct device *dev, struct device_attribute *attr, char *buf)
1205 {
1206         struct channel_path *chp = to_channelpath(dev);
1207
1208         if (!chp)
1209                 return 0;
1210         if (chp->shared == -1) /* channel measurements not available */
1211                 return sprintf(buf, "unknown\n");
1212         return sprintf(buf, "%x\n", chp->shared);
1213 }
1214
1215 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
1216
1217 static struct attribute * chp_attrs[] = {
1218         &dev_attr_status.attr,
1219         &dev_attr_type.attr,
1220         &dev_attr_cmg.attr,
1221         &dev_attr_shared.attr,
1222         NULL,
1223 };
1224
1225 static struct attribute_group chp_attr_group = {
1226         .attrs = chp_attrs,
1227 };
1228
1229 static void
1230 chp_release(struct device *dev)
1231 {
1232         struct channel_path *cp;
1233
1234         cp = container_of(dev, struct channel_path, dev);
1235         kfree(cp);
1236 }
1237
1238 static int
1239 chsc_determine_channel_path_description(int chpid,
1240                                         struct channel_path_desc *desc)
1241 {
1242         int ccode, ret;
1243
1244         struct {
1245                 struct chsc_header request;
1246                 u32 : 24;
1247                 u32 first_chpid : 8;
1248                 u32 : 24;
1249                 u32 last_chpid : 8;
1250                 u32 zeroes1;
1251                 struct chsc_header response;
1252                 u32 zeroes2;
1253                 struct channel_path_desc desc;
1254         } *scpd_area;
1255
1256         scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1257         if (!scpd_area)
1258                 return -ENOMEM;
1259
1260         scpd_area->request.length = 0x0010;
1261         scpd_area->request.code = 0x0002;
1262
1263         scpd_area->first_chpid = chpid;
1264         scpd_area->last_chpid = chpid;
1265
1266         ccode = chsc(scpd_area);
1267         if (ccode > 0) {
1268                 ret = (ccode == 3) ? -ENODEV : -EBUSY;
1269                 goto out;
1270         }
1271
1272         switch (scpd_area->response.code) {
1273         case 0x0001: /* Success. */
1274                 memcpy(desc, &scpd_area->desc,
1275                        sizeof(struct channel_path_desc));
1276                 ret = 0;
1277                 break;
1278         case 0x0003: /* Invalid block. */
1279         case 0x0007: /* Invalid format. */
1280         case 0x0008: /* Other invalid block. */
1281                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1282                 ret = -EINVAL;
1283                 break;
1284         case 0x0004: /* Command not provided in model. */
1285                 CIO_CRW_EVENT(2, "Model does not provide scpd\n");
1286                 ret = -EOPNOTSUPP;
1287                 break;
1288         default:
1289                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1290                               scpd_area->response.code);
1291                 ret = -EIO;
1292         }
1293 out:
1294         free_page((unsigned long)scpd_area);
1295         return ret;
1296 }
1297
1298 static void
1299 chsc_initialize_cmg_chars(struct channel_path *chp, u8 cmcv,
1300                           struct cmg_chars *chars)
1301 {
1302         switch (chp->cmg) {
1303         case 2:
1304         case 3:
1305                 chp->cmg_chars = kmalloc(sizeof(struct cmg_chars),
1306                                          GFP_KERNEL);
1307                 if (chp->cmg_chars) {
1308                         int i, mask;
1309                         struct cmg_chars *cmg_chars;
1310
1311                         cmg_chars = chp->cmg_chars;
1312                         for (i = 0; i < NR_MEASUREMENT_CHARS; i++) {
1313                                 mask = 0x80 >> (i + 3);
1314                                 if (cmcv & mask)
1315                                         cmg_chars->values[i] = chars->values[i];
1316                                 else
1317                                         cmg_chars->values[i] = 0;
1318                         }
1319                 }
1320                 break;
1321         default:
1322                 /* No cmg-dependent data. */
1323                 break;
1324         }
1325 }
1326
1327 static int
1328 chsc_get_channel_measurement_chars(struct channel_path *chp)
1329 {
1330         int ccode, ret;
1331
1332         struct {
1333                 struct chsc_header request;
1334                 u32 : 24;
1335                 u32 first_chpid : 8;
1336                 u32 : 24;
1337                 u32 last_chpid : 8;
1338                 u32 zeroes1;
1339                 struct chsc_header response;
1340                 u32 zeroes2;
1341                 u32 not_valid : 1;
1342                 u32 shared : 1;
1343                 u32 : 22;
1344                 u32 chpid : 8;
1345                 u32 cmcv : 5;
1346                 u32 : 11;
1347                 u32 cmgq : 8;
1348                 u32 cmg : 8;
1349                 u32 zeroes3;
1350                 u32 data[NR_MEASUREMENT_CHARS];
1351         } *scmc_area;
1352
1353         scmc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1354         if (!scmc_area)
1355                 return -ENOMEM;
1356
1357         scmc_area->request.length = 0x0010;
1358         scmc_area->request.code = 0x0022;
1359
1360         scmc_area->first_chpid = chp->id;
1361         scmc_area->last_chpid = chp->id;
1362
1363         ccode = chsc(scmc_area);
1364         if (ccode > 0) {
1365                 ret = (ccode == 3) ? -ENODEV : -EBUSY;
1366                 goto out;
1367         }
1368
1369         switch (scmc_area->response.code) {
1370         case 0x0001: /* Success. */
1371                 if (!scmc_area->not_valid) {
1372                         chp->cmg = scmc_area->cmg;
1373                         chp->shared = scmc_area->shared;
1374                         chsc_initialize_cmg_chars(chp, scmc_area->cmcv,
1375                                                   (struct cmg_chars *)
1376                                                   &scmc_area->data);
1377                 } else {
1378                         chp->cmg = -1;
1379                         chp->shared = -1;
1380                 }
1381                 ret = 0;
1382                 break;
1383         case 0x0003: /* Invalid block. */
1384         case 0x0007: /* Invalid format. */
1385         case 0x0008: /* Invalid bit combination. */
1386                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1387                 ret = -EINVAL;
1388                 break;
1389         case 0x0004: /* Command not provided. */
1390                 CIO_CRW_EVENT(2, "Model does not provide scmc\n");
1391                 ret = -EOPNOTSUPP;
1392                 break;
1393         default:
1394                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1395                               scmc_area->response.code);
1396                 ret = -EIO;
1397         }
1398 out:
1399         free_page((unsigned long)scmc_area);
1400         return ret;
1401 }
1402
1403 /*
1404  * Entries for chpids on the system bus.
1405  * This replaces /proc/chpids.
1406  */
1407 static int
1408 new_channel_path(int chpid)
1409 {
1410         struct channel_path *chp;
1411         int ret;
1412
1413         chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
1414         if (!chp)
1415                 return -ENOMEM;
1416
1417         /* fill in status, etc. */
1418         chp->id = chpid;
1419         chp->state = 1;
1420         chp->dev.parent = &css[0]->device;
1421         chp->dev.release = chp_release;
1422         snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp0.%x", chpid);
1423
1424         /* Obtain channel path description and fill it in. */
1425         ret = chsc_determine_channel_path_description(chpid, &chp->desc);
1426         if (ret)
1427                 goto out_free;
1428         /* Get channel-measurement characteristics. */
1429         if (css_characteristics_avail && css_chsc_characteristics.scmc
1430             && css_chsc_characteristics.secm) {
1431                 ret = chsc_get_channel_measurement_chars(chp);
1432                 if (ret)
1433                         goto out_free;
1434         } else {
1435                 static int msg_done;
1436
1437                 if (!msg_done) {
1438                         printk(KERN_WARNING "cio: Channel measurements not "
1439                                "available, continuing.\n");
1440                         msg_done = 1;
1441                 }
1442                 chp->cmg = -1;
1443         }
1444
1445         /* make it known to the system */
1446         ret = device_register(&chp->dev);
1447         if (ret) {
1448                 printk(KERN_WARNING "%s: could not register %02x\n",
1449                        __func__, chpid);
1450                 goto out_free;
1451         }
1452         ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
1453         if (ret) {
1454                 device_unregister(&chp->dev);
1455                 goto out_free;
1456         }
1457         mutex_lock(&css[0]->mutex);
1458         if (css[0]->cm_enabled) {
1459                 ret = chsc_add_chp_cmg_attr(chp);
1460                 if (ret) {
1461                         sysfs_remove_group(&chp->dev.kobj, &chp_attr_group);
1462                         device_unregister(&chp->dev);
1463                         mutex_unlock(&css[0]->mutex);
1464                         goto out_free;
1465                 }
1466         }
1467         css[0]->chps[chpid] = chp;
1468         mutex_unlock(&css[0]->mutex);
1469         return ret;
1470 out_free:
1471         kfree(chp);
1472         return ret;
1473 }
1474
1475 void *
1476 chsc_get_chp_desc(struct subchannel *sch, int chp_no)
1477 {
1478         struct channel_path *chp;
1479         struct channel_path_desc *desc;
1480
1481         chp = css[0]->chps[sch->schib.pmcw.chpid[chp_no]];
1482         if (!chp)
1483                 return NULL;
1484         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
1485         if (!desc)
1486                 return NULL;
1487         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
1488         return desc;
1489 }
1490
1491 static int __init
1492 chsc_alloc_sei_area(void)
1493 {
1494         sei_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1495         if (!sei_page)
1496                 printk(KERN_WARNING"Can't allocate page for processing of " \
1497                        "chsc machine checks!\n");
1498         return (sei_page ? 0 : -ENOMEM);
1499 }
1500
1501 int __init
1502 chsc_enable_facility(int operation_code)
1503 {
1504         int ret;
1505         struct {
1506                 struct chsc_header request;
1507                 u8 reserved1:4;
1508                 u8 format:4;
1509                 u8 reserved2;
1510                 u16 operation_code;
1511                 u32 reserved3;
1512                 u32 reserved4;
1513                 u32 operation_data_area[252];
1514                 struct chsc_header response;
1515                 u32 reserved5:4;
1516                 u32 format2:4;
1517                 u32 reserved6:24;
1518         } *sda_area;
1519
1520         sda_area = (void *)get_zeroed_page(GFP_KERNEL|GFP_DMA);
1521         if (!sda_area)
1522                 return -ENOMEM;
1523         sda_area->request.length = 0x0400;
1524         sda_area->request.code = 0x0031;
1525         sda_area->operation_code = operation_code;
1526
1527         ret = chsc(sda_area);
1528         if (ret > 0) {
1529                 ret = (ret == 3) ? -ENODEV : -EBUSY;
1530                 goto out;
1531         }
1532         switch (sda_area->response.code) {
1533         case 0x0001: /* everything ok */
1534                 ret = 0;
1535                 break;
1536         case 0x0003: /* invalid request block */
1537         case 0x0007:
1538                 ret = -EINVAL;
1539                 break;
1540         case 0x0004: /* command not provided */
1541         case 0x0101: /* facility not provided */
1542                 ret = -EOPNOTSUPP;
1543                 break;
1544         default: /* something went wrong */
1545                 ret = -EIO;
1546         }
1547  out:
1548         free_page((unsigned long)sda_area);
1549         return ret;
1550 }
1551
1552 subsys_initcall(chsc_alloc_sei_area);
1553
1554 struct css_general_char css_general_characteristics;
1555 struct css_chsc_char css_chsc_characteristics;
1556
1557 int __init
1558 chsc_determine_css_characteristics(void)
1559 {
1560         int result;
1561         struct {
1562                 struct chsc_header request;
1563                 u32 reserved1;
1564                 u32 reserved2;
1565                 u32 reserved3;
1566                 struct chsc_header response;
1567                 u32 reserved4;
1568                 u32 general_char[510];
1569                 u32 chsc_char[518];
1570         } *scsc_area;
1571
1572         scsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1573         if (!scsc_area) {
1574                 printk(KERN_WARNING"cio: Was not able to determine available" \
1575                        "CHSCs due to no memory.\n");
1576                 return -ENOMEM;
1577         }
1578
1579         scsc_area->request.length = 0x0010;
1580         scsc_area->request.code = 0x0010;
1581
1582         result = chsc(scsc_area);
1583         if (result) {
1584                 printk(KERN_WARNING"cio: Was not able to determine " \
1585                        "available CHSCs, cc=%i.\n", result);
1586                 result = -EIO;
1587                 goto exit;
1588         }
1589
1590         if (scsc_area->response.code != 1) {
1591                 printk(KERN_WARNING"cio: Was not able to determine " \
1592                        "available CHSCs.\n");
1593                 result = -EIO;
1594                 goto exit;
1595         }
1596         memcpy(&css_general_characteristics, scsc_area->general_char,
1597                sizeof(css_general_characteristics));
1598         memcpy(&css_chsc_characteristics, scsc_area->chsc_char,
1599                sizeof(css_chsc_characteristics));
1600 exit:
1601         free_page ((unsigned long) scsc_area);
1602         return result;
1603 }
1604
1605 EXPORT_SYMBOL_GPL(css_general_characteristics);
1606 EXPORT_SYMBOL_GPL(css_chsc_characteristics);