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                 /* Call handler. */
 255                 if (sch->driver && sch->driver->termination)
 256                         sch->driver->termination(&sch->dev);
 257                 goto out_unlock;
 258         }
 259
 260         /* trigger path verification. */
 261         if (sch->driver && sch->driver->verify)
 262                 sch->driver->verify(&sch->dev);
 263         else if (sch->lpm == mask)
 264                 goto out_unreg;
 265 out_unlock:
 266         spin_unlock_irq(&sch->lock);
 267         return 0;
 268 out_unreg:
 269         spin_unlock_irq(&sch->lock);
 270         sch->lpm = 0;
 271         if (css_enqueue_subchannel_slow(sch->schid)) {
 272                 css_clear_subchannel_slow_list();
 273                 need_rescan = 1;
 274         }
 275         return 0;
 276 }
 277
 278 static inline void
 279 s390_set_chpid_offline( __u8 chpid)
 280 {
 281         char dbf_txt[15];
 282         struct device *dev;
 283
 284         sprintf(dbf_txt, "chpr%x", chpid);
 285         CIO_TRACE_EVENT(2, dbf_txt);
 286
 287         if (get_chp_status(chpid) <= 0)
 288                 return;
 289         dev = get_device(&css[0]->chps[chpid]->dev);
 290         bus_for_each_dev(&css_bus_type, NULL, to_channelpath(dev),
 291                          s390_subchannel_remove_chpid);
 292
 293         if (need_rescan || css_slow_subchannels_exist())
 294                 queue_work(slow_path_wq, &slow_path_work);
 295         put_device(dev);
 296 }
 297
 298 struct res_acc_data {
 299         struct channel_path *chp;
 300         u32 fla_mask;
 301         u16 fla;
 302 };
 303
 304 static int
 305 s390_process_res_acc_sch(struct res_acc_data *res_data, struct subchannel *sch)
 306 {
 307         int found;
 308         int chp;
 309         int ccode;
 310
 311         found = 0;
 312         for (chp = 0; chp <= 7; chp++)
 313                 /*
 314                  * check if chpid is in information updated by ssd
 315                  */
 316                 if (sch->ssd_info.valid &&
 317                     sch->ssd_info.chpid[chp] == res_data->chp->id &&
 318                     (sch->ssd_info.fla[chp] & res_data->fla_mask)
 319                     == res_data->fla) {
 320                         found = 1;
 321                         break;
 322                 }
 323
 324         if (found == 0)
 325                 return 0;
 326
 327         /*
 328          * Do a stsch to update our subchannel structure with the
 329          * new path information and eventually check for logically
 330          * offline chpids.
 331          */
 332         ccode = stsch(sch->schid, &sch->schib);
 333         if (ccode > 0)
 334                 return 0;
 335
 336         return 0x80 >> chp;
 337 }
 338
 339 static inline int
 340 s390_process_res_acc_new_sch(struct subchannel_id schid)
 341 {
 342         struct schib schib;
 343         int ret;
 344         /*
 345          * We don't know the device yet, but since a path
 346          * may be available now to the device we'll have
 347          * to do recognition again.
 348          * Since we don't have any idea about which chpid
 349          * that beast may be on we'll have to do a stsch
 350          * on all devices, grr...
 351          */
 352         if (stsch_err(schid, &schib))
 353                 /* We're through */
 354                 return need_rescan ? -EAGAIN : -ENXIO;
 355
 356         /* Put it on the slow path. */
 357         ret = css_enqueue_subchannel_slow(schid);
 358         if (ret) {
 359                 css_clear_subchannel_slow_list();
 360                 need_rescan = 1;
 361                 return -EAGAIN;
 362         }
 363         return 0;
 364 }
 365
 366 static int
 367 __s390_process_res_acc(struct subchannel_id schid, void *data)
 368 {
 369         int chp_mask, old_lpm;
 370         struct res_acc_data *res_data;
 371         struct subchannel *sch;
 372
 373         res_data = (struct res_acc_data *)data;
 374         sch = get_subchannel_by_schid(schid);
 375         if (!sch)
 376                 /* Check if a subchannel is newly available. */
 377                 return s390_process_res_acc_new_sch(schid);
 378
 379         spin_lock_irq(&sch->lock);
 380
 381         chp_mask = s390_process_res_acc_sch(res_data, sch);
 382
 383         if (chp_mask == 0) {
 384                 spin_unlock_irq(&sch->lock);
 385                 put_device(&sch->dev);
 386                 return 0;
 387         }
 388         old_lpm = sch->lpm;
 389         sch->lpm = ((sch->schib.pmcw.pim &
 390                      sch->schib.pmcw.pam &
 391                      sch->schib.pmcw.pom)
 392                     | chp_mask) & sch->opm;
 393         if (!old_lpm && sch->lpm)
 394                 device_trigger_reprobe(sch);
 395         else if (sch->driver && sch->driver->verify)
 396                 sch->driver->verify(&sch->dev);
 397
 398         spin_unlock_irq(&sch->lock);
 399         put_device(&sch->dev);
 400         return 0;
 401 }
 402
 403
 404 static int
 405 s390_process_res_acc (struct res_acc_data *res_data)
 406 {
 407         int rc;
 408         char dbf_txt[15];
 409
 410         sprintf(dbf_txt, "accpr%x", res_data->chp->id);
 411         CIO_TRACE_EVENT( 2, dbf_txt);
 412         if (res_data->fla != 0) {
 413                 sprintf(dbf_txt, "fla%x", res_data->fla);
 414                 CIO_TRACE_EVENT( 2, dbf_txt);
 415         }
 416
 417         /*
 418          * I/O resources may have become accessible.
 419          * Scan through all subchannels that may be concerned and
 420          * do a validation on those.
 421          * The more information we have (info), the less scanning
 422          * will we have to do.
 423          */
 424         rc = for_each_subchannel(__s390_process_res_acc, res_data);
 425         if (css_slow_subchannels_exist())
 426                 rc = -EAGAIN;
 427         else if (rc != -EAGAIN)
 428                 rc = 0;
 429         return rc;
 430 }
 431
 432 static int
 433 __get_chpid_from_lir(void *data)
 434 {
 435         struct lir {
 436                 u8  iq;
 437                 u8  ic;
 438                 u16 sci;
 439                 /* incident-node descriptor */
 440                 u32 indesc[28];
 441                 /* attached-node descriptor */
 442                 u32 andesc[28];
 443                 /* incident-specific information */
 444                 u32 isinfo[28];
 445         } *lir;
 446
 447         lir = (struct lir*) data;
 448         if (!(lir->iq&0x80))
 449                 /* NULL link incident record */
 450                 return -EINVAL;
 451         if (!(lir->indesc[0]&0xc0000000))
 452                 /* node descriptor not valid */
 453                 return -EINVAL;
 454         if (!(lir->indesc[0]&0x10000000))
 455                 /* don't handle device-type nodes - FIXME */
 456                 return -EINVAL;
 457         /* Byte 3 contains the chpid. Could also be CTCA, but we don't care */
 458
 459         return (u16) (lir->indesc[0]&0x000000ff);
 460 }
 461
 462 int
 463 chsc_process_crw(void)
 464 {
 465         int chpid, ret;
 466         struct res_acc_data res_data;
 467         struct {
 468                 struct chsc_header request;
 469                 u32 reserved1;
 470                 u32 reserved2;
 471                 u32 reserved3;
 472                 struct chsc_header response;
 473                 u32 reserved4;
 474                 u8  flags;
 475                 u8  vf;         /* validity flags */
 476                 u8  rs;         /* reporting source */
 477                 u8  cc;         /* content code */
 478                 u16 fla;        /* full link address */
 479                 u16 rsid;       /* reporting source id */
 480                 u32 reserved5;
 481                 u32 reserved6;
 482                 u32 ccdf[96];   /* content-code dependent field */
 483                 /* ccdf has to be big enough for a link-incident record */
 484         } *sei_area;
 485
 486         if (!sei_page)
 487                 return 0;
 488         /*
 489          * build the chsc request block for store event information
 490          * and do the call
 491          * This function is only called by the machine check handler thread,
 492          * so we don't need locking for the sei_page.
 493          */
 494         sei_area = sei_page;
 495
 496         CIO_TRACE_EVENT( 2, "prcss");
 497         ret = 0;
 498         do {
 499                 int ccode, status;
 500                 struct device *dev;
 501                 memset(sei_area, 0, sizeof(*sei_area));
 502                 memset(&res_data, 0, sizeof(struct res_acc_data));
 503                 sei_area->request.length = 0x0010;
 504                 sei_area->request.code = 0x000e;
 505
 506                 ccode = chsc(sei_area);
 507                 if (ccode > 0)
 508                         return 0;
 509
 510                 switch (sei_area->response.code) {
 511                         /* for debug purposes, check for problems */
 512                 case 0x0001:
 513                         CIO_CRW_EVENT(4, "chsc_process_crw: event information "
 514                                         "successfully stored\n");
 515                         break; /* everything ok */
 516                 case 0x0002:
 517                         CIO_CRW_EVENT(2,
 518                                       "chsc_process_crw: invalid command!\n");
 519                         return 0;
 520                 case 0x0003:
 521                         CIO_CRW_EVENT(2, "chsc_process_crw: error in chsc "
 522                                       "request block!\n");
 523                         return 0;
 524                 case 0x0005:
 525                         CIO_CRW_EVENT(2, "chsc_process_crw: no event "
 526                                       "information stored\n");
 527                         return 0;
 528                 default:
 529                         CIO_CRW_EVENT(2, "chsc_process_crw: chsc response %d\n",
 530                                       sei_area->response.code);
 531                         return 0;
 532                 }
 533
 534                 /* Check if we might have lost some information. */
 535                 if (sei_area->flags & 0x40)
 536                         CIO_CRW_EVENT(2, "chsc_process_crw: Event information "
 537                                        "has been lost due to overflow!\n");
 538
 539                 if (sei_area->rs != 4) {
 540                         CIO_CRW_EVENT(2, "chsc_process_crw: reporting source "
 541                                       "(%04X) isn't a chpid!\n",
 542                                       sei_area->rsid);
 543                         continue;
 544                 }
 545
 546                 /* which kind of information was stored? */
 547                 switch (sei_area->cc) {
 548                 case 1: /* link incident*/
 549                         CIO_CRW_EVENT(4, "chsc_process_crw: "
 550                                       "channel subsystem reports link incident,"
 551                                       " reporting source is chpid %x\n",
 552                                       sei_area->rsid);
 553                         chpid = __get_chpid_from_lir(sei_area->ccdf);
 554                         if (chpid < 0)
 555                                 CIO_CRW_EVENT(4, "%s: Invalid LIR, skipping\n",
 556                                               __FUNCTION__);
 557                         else
 558                                 s390_set_chpid_offline(chpid);
 559                         break;
 560
 561                 case 2: /* i/o resource accessibiliy */
 562                         CIO_CRW_EVENT(4, "chsc_process_crw: "
 563                                       "channel subsystem reports some I/O "
 564                                       "devices may have become accessible\n");
 565                         pr_debug("Data received after sei: \n");
 566                         pr_debug("Validity flags: %x\n", sei_area->vf);
 567
 568                         /* allocate a new channel path structure, if needed */
 569                         status = get_chp_status(sei_area->rsid);
 570                         if (status < 0)
 571                                 new_channel_path(sei_area->rsid);
 572                         else if (!status)
 573                                 break;
 574                         dev = get_device(&css[0]->chps[sei_area->rsid]->dev);
 575                         res_data.chp = to_channelpath(dev);
 576                         pr_debug("chpid: %x", sei_area->rsid);
 577                         if ((sei_area->vf & 0xc0) != 0) {
 578                                 res_data.fla = sei_area->fla;
 579                                 if ((sei_area->vf & 0xc0) == 0xc0) {
 580                                         pr_debug(" full link addr: %x",
 581                                                  sei_area->fla);
 582                                         res_data.fla_mask = 0xffff;
 583                                 } else {
 584                                         pr_debug(" link addr: %x",
 585                                                  sei_area->fla);
 586                                         res_data.fla_mask = 0xff00;
 587                                 }
 588                         }
 589                         ret = s390_process_res_acc(&res_data);
 590                         pr_debug("\n\n");
 591                         put_device(dev);
 592                         break;
 593
 594                 default: /* other stuff */
 595                         CIO_CRW_EVENT(4, "chsc_process_crw: event %d\n",
 596                                       sei_area->cc);
 597                         break;
 598                 }
 599         } while (sei_area->flags & 0x80);
 600         return ret;
 601 }
 602
 603 static inline int
 604 __chp_add_new_sch(struct subchannel_id schid)
 605 {
 606         struct schib schib;
 607         int ret;
 608
 609         if (stsch(schid, &schib))
 610                 /* We're through */
 611                 return need_rescan ? -EAGAIN : -ENXIO;
 612
 613         /* Put it on the slow path. */
 614         ret = css_enqueue_subchannel_slow(schid);
 615         if (ret) {
 616                 css_clear_subchannel_slow_list();
 617                 need_rescan = 1;
 618                 return -EAGAIN;
 619         }
 620         return 0;
 621 }
 622
 623
 624 static int
 625 __chp_add(struct subchannel_id schid, void *data)
 626 {
 627         int i, mask;
 628         struct channel_path *chp;
 629         struct subchannel *sch;
 630
 631         chp = (struct channel_path *)data;
 632         sch = get_subchannel_by_schid(schid);
 633         if (!sch)
 634                 /* Check if the subchannel is now available. */
 635                 return __chp_add_new_sch(schid);
 636         spin_lock_irq(&sch->lock);
 637         for (i=0; i<8; i++) {
 638                 mask = 0x80 >> i;
 639                 if ((sch->schib.pmcw.pim & mask) &&
 640                     (sch->schib.pmcw.chpid[i] == chp->id)) {
 641                         if (stsch(sch->schid, &sch->schib) != 0) {
 642                                 /* Endgame. */
 643                                 spin_unlock_irq(&sch->lock);
 644                                 return -ENXIO;
 645                         }
 646                         break;
 647                 }
 648         }
 649         if (i==8) {
 650                 spin_unlock_irq(&sch->lock);
 651                 return 0;
 652         }
 653         sch->lpm = ((sch->schib.pmcw.pim &
 654                      sch->schib.pmcw.pam &
 655                      sch->schib.pmcw.pom)
 656                     | mask) & sch->opm;
 657
 658         if (sch->driver && sch->driver->verify)
 659                 sch->driver->verify(&sch->dev);
 660
 661         spin_unlock_irq(&sch->lock);
 662         put_device(&sch->dev);
 663         return 0;
 664 }
 665
 666 static int
 667 chp_add(int chpid)
 668 {
 669         int rc;
 670         char dbf_txt[15];
 671         struct device *dev;
 672
 673         if (!get_chp_status(chpid))
 674                 return 0; /* no need to do the rest */
 675
 676         sprintf(dbf_txt, "cadd%x", chpid);
 677         CIO_TRACE_EVENT(2, dbf_txt);
 678
 679         dev = get_device(&css[0]->chps[chpid]->dev);
 680         rc = for_each_subchannel(__chp_add, to_channelpath(dev));
 681         if (css_slow_subchannels_exist())
 682                 rc = -EAGAIN;
 683         if (rc != -EAGAIN)
 684                 rc = 0;
 685         put_device(dev);
 686         return rc;
 687 }
 688
 689 /*
 690  * Handling of crw machine checks with channel path source.
 691  */
 692 int
 693 chp_process_crw(int chpid, int on)
 694 {
 695         if (on == 0) {
 696                 /* Path has gone. We use the link incident routine.*/
 697                 s390_set_chpid_offline(chpid);
 698                 return 0; /* De-register is async anyway. */
 699         }
 700         /*
 701          * Path has come. Allocate a new channel path structure,
 702          * if needed.
 703          */
 704         if (get_chp_status(chpid) < 0)
 705                 new_channel_path(chpid);
 706         /* Avoid the extra overhead in process_rec_acc. */
 707         return chp_add(chpid);
 708 }
 709
 710 static inline int
 711 __check_for_io_and_kill(struct subchannel *sch, int index)
 712 {
 713         int cc;
 714
 715         if (!device_is_online(sch))
 716                 /* cio could be doing I/O. */
 717                 return 0;
 718         cc = stsch(sch->schid, &sch->schib);
 719         if (cc)
 720                 return 0;
 721         if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index)) {
 722                 device_set_waiting(sch);
 723                 return 1;
 724         }
 725         return 0;
 726 }
 727
 728 static inline void
 729 __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
 730 {
 731         int chp, old_lpm;
 732         unsigned long flags;
 733
 734         if (!sch->ssd_info.valid)
 735                 return;
 736
 737         spin_lock_irqsave(&sch->lock, flags);
 738         old_lpm = sch->lpm;
 739         for (chp = 0; chp < 8; chp++) {
 740                 if (sch->ssd_info.chpid[chp] != chpid)
 741                         continue;
 742
 743                 if (on) {
 744                         sch->opm |= (0x80 >> chp);
 745                         sch->lpm |= (0x80 >> chp);
 746                         if (!old_lpm)
 747                                 device_trigger_reprobe(sch);
 748                         else if (sch->driver && sch->driver->verify)
 749                                 sch->driver->verify(&sch->dev);
 750                 } else {
 751                         sch->opm &= ~(0x80 >> chp);
 752                         sch->lpm &= ~(0x80 >> chp);
 753                         /*
 754                          * Give running I/O a grace period in which it
 755                          * can successfully terminate, even using the
 756                          * just varied off path. Then kill it.
 757                          */
 758                         if (!__check_for_io_and_kill(sch, chp) && !sch->lpm) {
 759                                 if (css_enqueue_subchannel_slow(sch->schid)) {
 760                                         css_clear_subchannel_slow_list();
 761                                         need_rescan = 1;
 762                                 }
 763                         } else if (sch->driver && sch->driver->verify)
 764                                 sch->driver->verify(&sch->dev);
 765                 }
 766                 break;
 767         }
 768         spin_unlock_irqrestore(&sch->lock, flags);
 769 }
 770
 771 static int
 772 s390_subchannel_vary_chpid_off(struct device *dev, void *data)
 773 {
 774         struct subchannel *sch;
 775         __u8 *chpid;
 776
 777         sch = to_subchannel(dev);
 778         chpid = data;
 779
 780         __s390_subchannel_vary_chpid(sch, *chpid, 0);
 781         return 0;
 782 }
 783
 784 static int
 785 s390_subchannel_vary_chpid_on(struct device *dev, void *data)
 786 {
 787         struct subchannel *sch;
 788         __u8 *chpid;
 789
 790         sch = to_subchannel(dev);
 791         chpid = data;
 792
 793         __s390_subchannel_vary_chpid(sch, *chpid, 1);
 794         return 0;
 795 }
 796
 797 static int
 798 __s390_vary_chpid_on(struct subchannel_id schid, void *data)
 799 {
 800         struct schib schib;
 801         struct subchannel *sch;
 802
 803         sch = get_subchannel_by_schid(schid);
 804         if (sch) {
 805                 put_device(&sch->dev);
 806                 return 0;
 807         }
 808         if (stsch_err(schid, &schib))
 809                 /* We're through */
 810                 return -ENXIO;
 811         /* Put it on the slow path. */
 812         if (css_enqueue_subchannel_slow(schid)) {
 813                 css_clear_subchannel_slow_list();
 814                 need_rescan = 1;
 815                 return -EAGAIN;
 816         }
 817         return 0;
 818 }
 819
 820 /*
 821  * Function: s390_vary_chpid
 822  * Varies the specified chpid online or offline
 823  */
 824 static int
 825 s390_vary_chpid( __u8 chpid, int on)
 826 {
 827         char dbf_text[15];
 828         int status;
 829
 830         sprintf(dbf_text, on?"varyon%x":"varyoff%x", chpid);
 831         CIO_TRACE_EVENT( 2, dbf_text);
 832
 833         status = get_chp_status(chpid);
 834         if (status < 0) {
 835                 printk(KERN_ERR "Can't vary unknown chpid %02X\n", chpid);
 836                 return -EINVAL;
 837         }
 838
 839         if (!on && !status) {
 840                 printk(KERN_ERR "chpid %x is already offline\n", chpid);
 841                 return -EINVAL;
 842         }
 843
 844         set_chp_logically_online(chpid, on);
 845
 846         /*
 847          * Redo PathVerification on the devices the chpid connects to
 848          */
 849
 850         bus_for_each_dev(&css_bus_type, NULL, &chpid, on ?
 851                          s390_subchannel_vary_chpid_on :
 852                          s390_subchannel_vary_chpid_off);
 853         if (on)
 854                 /* Scan for new devices on varied on path. */
 855                 for_each_subchannel(__s390_vary_chpid_on, NULL);
 856         if (need_rescan || css_slow_subchannels_exist())
 857                 queue_work(slow_path_wq, &slow_path_work);
 858         return 0;
 859 }
 860
 861 /*
 862  * Channel measurement related functions
 863  */
 864 static ssize_t
 865 chp_measurement_chars_read(struct kobject *kobj, char *buf, loff_t off,
 866                            size_t count)
 867 {
 868         struct channel_path *chp;
 869         unsigned int size;
 870
 871         chp = to_channelpath(container_of(kobj, struct device, kobj));
 872         if (!chp->cmg_chars)
 873                 return 0;
 874
 875         size = sizeof(struct cmg_chars);
 876
 877         if (off > size)
 878                 return 0;
 879         if (off + count > size)
 880                 count = size - off;
 881         memcpy(buf, chp->cmg_chars + off, count);
 882         return count;
 883 }
 884
 885 static struct bin_attribute chp_measurement_chars_attr = {
 886         .attr = {
 887                 .name = "measurement_chars",
 888                 .mode = S_IRUSR,
 889                 .owner = THIS_MODULE,
 890         },
 891         .size = sizeof(struct cmg_chars),
 892         .read = chp_measurement_chars_read,
 893 };
 894
 895 static void
 896 chp_measurement_copy_block(struct cmg_entry *buf,
 897                            struct channel_subsystem *css, int chpid)
 898 {
 899         void *area;
 900         struct cmg_entry *entry, reference_buf;
 901         int idx;
 902
 903         if (chpid < 128) {
 904                 area = css->cub_addr1;
 905                 idx = chpid;
 906         } else {
 907                 area = css->cub_addr2;
 908                 idx = chpid - 128;
 909         }
 910         entry = area + (idx * sizeof(struct cmg_entry));
 911         do {
 912                 memcpy(buf, entry, sizeof(*entry));
 913                 memcpy(&reference_buf, entry, sizeof(*entry));
 914         } while (reference_buf.values[0] != buf->values[0]);
 915 }
 916
 917 static ssize_t
 918 chp_measurement_read(struct kobject *kobj, char *buf, loff_t off, size_t count)
 919 {
 920         struct channel_path *chp;
 921         struct channel_subsystem *css;
 922         unsigned int size;
 923
 924         chp = to_channelpath(container_of(kobj, struct device, kobj));
 925         css = to_css(chp->dev.parent);
 926
 927         size = sizeof(struct cmg_entry);
 928
 929         /* Only allow single reads. */
 930         if (off || count < size)
 931                 return 0;
 932         chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->id);
 933         count = size;
 934         return count;
 935 }
 936
 937 static struct bin_attribute chp_measurement_attr = {
 938         .attr = {
 939                 .name = "measurement",
 940                 .mode = S_IRUSR,
 941                 .owner = THIS_MODULE,
 942         },
 943         .size = sizeof(struct cmg_entry),
 944         .read = chp_measurement_read,
 945 };
 946
 947 static void
 948 chsc_remove_chp_cmg_attr(struct channel_path *chp)
 949 {
 950         sysfs_remove_bin_file(&chp->dev.kobj, &chp_measurement_chars_attr);
 951         sysfs_remove_bin_file(&chp->dev.kobj, &chp_measurement_attr);
 952 }
 953
 954 static int
 955 chsc_add_chp_cmg_attr(struct channel_path *chp)
 956 {
 957         int ret;
 958
 959         ret = sysfs_create_bin_file(&chp->dev.kobj,
 960                                     &chp_measurement_chars_attr);
 961         if (ret)
 962                 return ret;
 963         ret = sysfs_create_bin_file(&chp->dev.kobj, &chp_measurement_attr);
 964         if (ret)
 965                 sysfs_remove_bin_file(&chp->dev.kobj,
 966                                       &chp_measurement_chars_attr);
 967         return ret;
 968 }
 969
 970 static void
 971 chsc_remove_cmg_attr(struct channel_subsystem *css)
 972 {
 973         int i;
 974
 975         for (i = 0; i <= __MAX_CHPID; i++) {
 976                 if (!css->chps[i])
 977                         continue;
 978                 chsc_remove_chp_cmg_attr(css->chps[i]);
 979         }
 980 }
 981
 982 static int
 983 chsc_add_cmg_attr(struct channel_subsystem *css)
 984 {
 985         int i, ret;
 986
 987         ret = 0;
 988         for (i = 0; i <= __MAX_CHPID; i++) {
 989                 if (!css->chps[i])
 990                         continue;
 991                 ret = chsc_add_chp_cmg_attr(css->chps[i]);
 992                 if (ret)
 993                         goto cleanup;
 994         }
 995         return ret;
 996 cleanup:
 997         for (--i; i >= 0; i--) {
 998                 if (!css->chps[i])
 999                         continue;
1000                 chsc_remove_chp_cmg_attr(css->chps[i]);
1001         }
1002         return ret;
1003 }
1004
1005
1006 static int
1007 __chsc_do_secm(struct channel_subsystem *css, int enable, void *page)
1008 {
1009         struct {
1010                 struct chsc_header request;
1011                 u32 operation_code : 2;
1012                 u32 : 30;
1013                 u32 key : 4;
1014                 u32 : 28;
1015                 u32 zeroes1;
1016                 u32 cub_addr1;
1017                 u32 zeroes2;
1018                 u32 cub_addr2;
1019                 u32 reserved[13];
1020                 struct chsc_header response;
1021                 u32 status : 8;
1022                 u32 : 4;
1023                 u32 fmt : 4;
1024                 u32 : 16;
1025         } *secm_area;
1026         int ret, ccode;
1027
1028         secm_area = page;
1029         secm_area->request.length = 0x0050;
1030         secm_area->request.code = 0x0016;
1031
1032         secm_area->key = PAGE_DEFAULT_KEY;
1033         secm_area->cub_addr1 = (u64)(unsigned long)css->cub_addr1;
1034         secm_area->cub_addr2 = (u64)(unsigned long)css->cub_addr2;
1035
1036         secm_area->operation_code = enable ? 0 : 1;
1037
1038         ccode = chsc(secm_area);
1039         if (ccode > 0)
1040                 return (ccode == 3) ? -ENODEV : -EBUSY;
1041
1042         switch (secm_area->response.code) {
1043         case 0x0001: /* Success. */
1044                 ret = 0;
1045                 break;
1046         case 0x0003: /* Invalid block. */
1047         case 0x0007: /* Invalid format. */
1048         case 0x0008: /* Other invalid block. */
1049                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1050                 ret = -EINVAL;
1051                 break;
1052         case 0x0004: /* Command not provided in model. */
1053                 CIO_CRW_EVENT(2, "Model does not provide secm\n");
1054                 ret = -EOPNOTSUPP;
1055                 break;
1056         case 0x0102: /* cub adresses incorrect */
1057                 CIO_CRW_EVENT(2, "Invalid addresses in chsc request block\n");
1058                 ret = -EINVAL;
1059                 break;
1060         case 0x0103: /* key error */
1061                 CIO_CRW_EVENT(2, "Access key error in secm\n");
1062                 ret = -EINVAL;
1063                 break;
1064         case 0x0105: /* error while starting */
1065                 CIO_CRW_EVENT(2, "Error while starting channel measurement\n");
1066                 ret = -EIO;
1067                 break;
1068         default:
1069                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1070                               secm_area->response.code);
1071                 ret = -EIO;
1072         }
1073         return ret;
1074 }
1075
1076 int
1077 chsc_secm(struct channel_subsystem *css, int enable)
1078 {
1079         void  *secm_area;
1080         int ret;
1081
1082         secm_area = (void *)get_zeroed_page(GFP_KERNEL |  GFP_DMA);
1083         if (!secm_area)
1084                 return -ENOMEM;
1085
1086         mutex_lock(&css->mutex);
1087         if (enable && !css->cm_enabled) {
1088                 css->cub_addr1 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1089                 css->cub_addr2 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1090                 if (!css->cub_addr1 || !css->cub_addr2) {
1091                         free_page((unsigned long)css->cub_addr1);
1092                         free_page((unsigned long)css->cub_addr2);
1093                         free_page((unsigned long)secm_area);
1094                         mutex_unlock(&css->mutex);
1095                         return -ENOMEM;
1096                 }
1097         }
1098         ret = __chsc_do_secm(css, enable, secm_area);
1099         if (!ret) {
1100                 css->cm_enabled = enable;
1101                 if (css->cm_enabled) {
1102                         ret = chsc_add_cmg_attr(css);
1103                         if (ret) {
1104                                 memset(secm_area, 0, PAGE_SIZE);
1105                                 __chsc_do_secm(css, 0, secm_area);
1106                                 css->cm_enabled = 0;
1107                         }
1108                 } else
1109                         chsc_remove_cmg_attr(css);
1110         }
1111         if (enable && !css->cm_enabled) {
1112                 free_page((unsigned long)css->cub_addr1);
1113                 free_page((unsigned long)css->cub_addr2);
1114         }
1115         mutex_unlock(&css->mutex);
1116         free_page((unsigned long)secm_area);
1117         return ret;
1118 }
1119
1120 /*
1121  * Files for the channel path entries.
1122  */
1123 static ssize_t
1124 chp_status_show(struct device *dev, struct device_attribute *attr, char *buf)
1125 {
1126         struct channel_path *chp = container_of(dev, struct channel_path, dev);
1127
1128         if (!chp)
1129                 return 0;
1130         return (get_chp_status(chp->id) ? sprintf(buf, "online\n") :
1131                 sprintf(buf, "offline\n"));
1132 }
1133
1134 static ssize_t
1135 chp_status_write(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
1136 {
1137         struct channel_path *cp = container_of(dev, struct channel_path, dev);
1138         char cmd[10];
1139         int num_args;
1140         int error;
1141
1142         num_args = sscanf(buf, "%5s", cmd);
1143         if (!num_args)
1144                 return count;
1145
1146         if (!strnicmp(cmd, "on", 2))
1147                 error = s390_vary_chpid(cp->id, 1);
1148         else if (!strnicmp(cmd, "off", 3))
1149                 error = s390_vary_chpid(cp->id, 0);
1150         else
1151                 error = -EINVAL;
1152
1153         return error < 0 ? error : count;
1154
1155 }
1156
1157 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
1158
1159 static ssize_t
1160 chp_type_show(struct device *dev, struct device_attribute *attr, char *buf)
1161 {
1162         struct channel_path *chp = container_of(dev, struct channel_path, dev);
1163
1164         if (!chp)
1165                 return 0;
1166         return sprintf(buf, "%x\n", chp->desc.desc);
1167 }
1168
1169 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
1170
1171 static ssize_t
1172 chp_cmg_show(struct device *dev, struct device_attribute *attr, char *buf)
1173 {
1174         struct channel_path *chp = to_channelpath(dev);
1175
1176         if (!chp)
1177                 return 0;
1178         if (chp->cmg == -1) /* channel measurements not available */
1179                 return sprintf(buf, "unknown\n");
1180         return sprintf(buf, "%x\n", chp->cmg);
1181 }
1182
1183 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
1184
1185 static ssize_t
1186 chp_shared_show(struct device *dev, struct device_attribute *attr, char *buf)
1187 {
1188         struct channel_path *chp = to_channelpath(dev);
1189
1190         if (!chp)
1191                 return 0;
1192         if (chp->shared == -1) /* channel measurements not available */
1193                 return sprintf(buf, "unknown\n");
1194         return sprintf(buf, "%x\n", chp->shared);
1195 }
1196
1197 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
1198
1199 static struct attribute * chp_attrs[] = {
1200         &dev_attr_status.attr,
1201         &dev_attr_type.attr,
1202         &dev_attr_cmg.attr,
1203         &dev_attr_shared.attr,
1204         NULL,
1205 };
1206
1207 static struct attribute_group chp_attr_group = {
1208         .attrs = chp_attrs,
1209 };
1210
1211 static void
1212 chp_release(struct device *dev)
1213 {
1214         struct channel_path *cp;
1215
1216         cp = container_of(dev, struct channel_path, dev);
1217         kfree(cp);
1218 }
1219
1220 static int
1221 chsc_determine_channel_path_description(int chpid,
1222                                         struct channel_path_desc *desc)
1223 {
1224         int ccode, ret;
1225
1226         struct {
1227                 struct chsc_header request;
1228                 u32 : 24;
1229                 u32 first_chpid : 8;
1230                 u32 : 24;
1231                 u32 last_chpid : 8;
1232                 u32 zeroes1;
1233                 struct chsc_header response;
1234                 u32 zeroes2;
1235                 struct channel_path_desc desc;
1236         } *scpd_area;
1237
1238         scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1239         if (!scpd_area)
1240                 return -ENOMEM;
1241
1242         scpd_area->request.length = 0x0010;
1243         scpd_area->request.code = 0x0002;
1244
1245         scpd_area->first_chpid = chpid;
1246         scpd_area->last_chpid = chpid;
1247
1248         ccode = chsc(scpd_area);
1249         if (ccode > 0) {
1250                 ret = (ccode == 3) ? -ENODEV : -EBUSY;
1251                 goto out;
1252         }
1253
1254         switch (scpd_area->response.code) {
1255         case 0x0001: /* Success. */
1256                 memcpy(desc, &scpd_area->desc,
1257                        sizeof(struct channel_path_desc));
1258                 ret = 0;
1259                 break;
1260         case 0x0003: /* Invalid block. */
1261         case 0x0007: /* Invalid format. */
1262         case 0x0008: /* Other invalid block. */
1263                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1264                 ret = -EINVAL;
1265                 break;
1266         case 0x0004: /* Command not provided in model. */
1267                 CIO_CRW_EVENT(2, "Model does not provide scpd\n");
1268                 ret = -EOPNOTSUPP;
1269                 break;
1270         default:
1271                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1272                               scpd_area->response.code);
1273                 ret = -EIO;
1274         }
1275 out:
1276         free_page((unsigned long)scpd_area);
1277         return ret;
1278 }
1279
1280 static void
1281 chsc_initialize_cmg_chars(struct channel_path *chp, u8 cmcv,
1282                           struct cmg_chars *chars)
1283 {
1284         switch (chp->cmg) {
1285         case 2:
1286         case 3:
1287                 chp->cmg_chars = kmalloc(sizeof(struct cmg_chars),
1288                                          GFP_KERNEL);
1289                 if (chp->cmg_chars) {
1290                         int i, mask;
1291                         struct cmg_chars *cmg_chars;
1292
1293                         cmg_chars = chp->cmg_chars;
1294                         for (i = 0; i < NR_MEASUREMENT_CHARS; i++) {
1295                                 mask = 0x80 >> (i + 3);
1296                                 if (cmcv & mask)
1297                                         cmg_chars->values[i] = chars->values[i];
1298                                 else
1299                                         cmg_chars->values[i] = 0;
1300                         }
1301                 }
1302                 break;
1303         default:
1304                 /* No cmg-dependent data. */
1305                 break;
1306         }
1307 }
1308
1309 static int
1310 chsc_get_channel_measurement_chars(struct channel_path *chp)
1311 {
1312         int ccode, ret;
1313
1314         struct {
1315                 struct chsc_header request;
1316                 u32 : 24;
1317                 u32 first_chpid : 8;
1318                 u32 : 24;
1319                 u32 last_chpid : 8;
1320                 u32 zeroes1;
1321                 struct chsc_header response;
1322                 u32 zeroes2;
1323                 u32 not_valid : 1;
1324                 u32 shared : 1;
1325                 u32 : 22;
1326                 u32 chpid : 8;
1327                 u32 cmcv : 5;
1328                 u32 : 11;
1329                 u32 cmgq : 8;
1330                 u32 cmg : 8;
1331                 u32 zeroes3;
1332                 u32 data[NR_MEASUREMENT_CHARS];
1333         } *scmc_area;
1334
1335         scmc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1336         if (!scmc_area)
1337                 return -ENOMEM;
1338
1339         scmc_area->request.length = 0x0010;
1340         scmc_area->request.code = 0x0022;
1341
1342         scmc_area->first_chpid = chp->id;
1343         scmc_area->last_chpid = chp->id;
1344
1345         ccode = chsc(scmc_area);
1346         if (ccode > 0) {
1347                 ret = (ccode == 3) ? -ENODEV : -EBUSY;
1348                 goto out;
1349         }
1350
1351         switch (scmc_area->response.code) {
1352         case 0x0001: /* Success. */
1353                 if (!scmc_area->not_valid) {
1354                         chp->cmg = scmc_area->cmg;
1355                         chp->shared = scmc_area->shared;
1356                         chsc_initialize_cmg_chars(chp, scmc_area->cmcv,
1357                                                   (struct cmg_chars *)
1358                                                   &scmc_area->data);
1359                 } else {
1360                         chp->cmg = -1;
1361                         chp->shared = -1;
1362                 }
1363                 ret = 0;
1364                 break;
1365         case 0x0003: /* Invalid block. */
1366         case 0x0007: /* Invalid format. */
1367         case 0x0008: /* Invalid bit combination. */
1368                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1369                 ret = -EINVAL;
1370                 break;
1371         case 0x0004: /* Command not provided. */
1372                 CIO_CRW_EVENT(2, "Model does not provide scmc\n");
1373                 ret = -EOPNOTSUPP;
1374                 break;
1375         default:
1376                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1377                               scmc_area->response.code);
1378                 ret = -EIO;
1379         }
1380 out:
1381         free_page((unsigned long)scmc_area);
1382         return ret;
1383 }
1384
1385 /*
1386  * Entries for chpids on the system bus.
1387  * This replaces /proc/chpids.
1388  */
1389 static int
1390 new_channel_path(int chpid)
1391 {
1392         struct channel_path *chp;
1393         int ret;
1394
1395         chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
1396         if (!chp)
1397                 return -ENOMEM;
1398
1399         /* fill in status, etc. */
1400         chp->id = chpid;
1401         chp->state = 1;
1402         chp->dev.parent = &css[0]->device;
1403         chp->dev.release = chp_release;
1404         snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp0.%x", chpid);
1405
1406         /* Obtain channel path description and fill it in. */
1407         ret = chsc_determine_channel_path_description(chpid, &chp->desc);
1408         if (ret)
1409                 goto out_free;
1410         /* Get channel-measurement characteristics. */
1411         if (css_characteristics_avail && css_chsc_characteristics.scmc
1412             && css_chsc_characteristics.secm) {
1413                 ret = chsc_get_channel_measurement_chars(chp);
1414                 if (ret)
1415                         goto out_free;
1416         } else {
1417                 static int msg_done;
1418
1419                 if (!msg_done) {
1420                         printk(KERN_WARNING "cio: Channel measurements not "
1421                                "available, continuing.\n");
1422                         msg_done = 1;
1423                 }
1424                 chp->cmg = -1;
1425         }
1426
1427         /* make it known to the system */
1428         ret = device_register(&chp->dev);
1429         if (ret) {
1430                 printk(KERN_WARNING "%s: could not register %02x\n",
1431                        __func__, chpid);
1432                 goto out_free;
1433         }
1434         ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
1435         if (ret) {
1436                 device_unregister(&chp->dev);
1437                 goto out_free;
1438         }
1439         mutex_lock(&css[0]->mutex);
1440         if (css[0]->cm_enabled) {
1441                 ret = chsc_add_chp_cmg_attr(chp);
1442                 if (ret) {
1443                         sysfs_remove_group(&chp->dev.kobj, &chp_attr_group);
1444                         device_unregister(&chp->dev);
1445                         mutex_unlock(&css[0]->mutex);
1446                         goto out_free;
1447                 }
1448         }
1449         css[0]->chps[chpid] = chp;
1450         mutex_unlock(&css[0]->mutex);
1451         return ret;
1452 out_free:
1453         kfree(chp);
1454         return ret;
1455 }
1456
1457 void *
1458 chsc_get_chp_desc(struct subchannel *sch, int chp_no)
1459 {
1460         struct channel_path *chp;
1461         struct channel_path_desc *desc;
1462
1463         chp = css[0]->chps[sch->schib.pmcw.chpid[chp_no]];
1464         if (!chp)
1465                 return NULL;
1466         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
1467         if (!desc)
1468                 return NULL;
1469         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
1470         return desc;
1471 }
1472
1473 static int reset_channel_path(struct channel_path *chp)
1474 {
1475         int cc;
1476
1477         cc = rchp(chp->id);
1478         switch (cc) {
1479         case 0:
1480                 return 0;
1481         case 2:
1482                 return -EBUSY;
1483         default:
1484                 return -ENODEV;
1485         }
1486 }
1487
1488 static void reset_channel_paths_css(struct channel_subsystem *css)
1489 {
1490         int i;
1491
1492         for (i = 0; i <= __MAX_CHPID; i++) {
1493                 if (css->chps[i])
1494                         reset_channel_path(css->chps[i]);
1495         }
1496 }
1497
1498 void cio_reset_channel_paths(void)
1499 {
1500         int i;
1501
1502         for (i = 0; i <= __MAX_CSSID; i++) {
1503                 if (css[i] && css[i]->valid)
1504                         reset_channel_paths_css(css[i]);
1505         }
1506 }
1507
1508 static int __init
1509 chsc_alloc_sei_area(void)
1510 {
1511         sei_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1512         if (!sei_page)
1513                 printk(KERN_WARNING"Can't allocate page for processing of " \
1514                        "chsc machine checks!\n");
1515         return (sei_page ? 0 : -ENOMEM);
1516 }
1517
1518 int __init
1519 chsc_enable_facility(int operation_code)
1520 {
1521         int ret;
1522         struct {
1523                 struct chsc_header request;
1524                 u8 reserved1:4;
1525                 u8 format:4;
1526                 u8 reserved2;
1527                 u16 operation_code;
1528                 u32 reserved3;
1529                 u32 reserved4;
1530                 u32 operation_data_area[252];
1531                 struct chsc_header response;
1532                 u32 reserved5:4;
1533                 u32 format2:4;
1534                 u32 reserved6:24;
1535         } *sda_area;
1536
1537         sda_area = (void *)get_zeroed_page(GFP_KERNEL|GFP_DMA);
1538         if (!sda_area)
1539                 return -ENOMEM;
1540         sda_area->request.length = 0x0400;
1541         sda_area->request.code = 0x0031;
1542         sda_area->operation_code = operation_code;
1543
1544         ret = chsc(sda_area);
1545         if (ret > 0) {
1546                 ret = (ret == 3) ? -ENODEV : -EBUSY;
1547                 goto out;
1548         }
1549         switch (sda_area->response.code) {
1550         case 0x0001: /* everything ok */
1551                 ret = 0;
1552                 break;
1553         case 0x0003: /* invalid request block */
1554         case 0x0007:
1555                 ret = -EINVAL;
1556                 break;
1557         case 0x0004: /* command not provided */
1558         case 0x0101: /* facility not provided */
1559                 ret = -EOPNOTSUPP;
1560                 break;
1561         default: /* something went wrong */
1562                 ret = -EIO;
1563         }
1564  out:
1565         free_page((unsigned long)sda_area);
1566         return ret;
1567 }
1568
1569 subsys_initcall(chsc_alloc_sei_area);
1570
1571 struct css_general_char css_general_characteristics;
1572 struct css_chsc_char css_chsc_characteristics;
1573
1574 int __init
1575 chsc_determine_css_characteristics(void)
1576 {
1577         int result;
1578         struct {
1579                 struct chsc_header request;
1580                 u32 reserved1;
1581                 u32 reserved2;
1582                 u32 reserved3;
1583                 struct chsc_header response;
1584                 u32 reserved4;
1585                 u32 general_char[510];
1586                 u32 chsc_char[518];
1587         } *scsc_area;
1588
1589         scsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1590         if (!scsc_area) {
1591                 printk(KERN_WARNING"cio: Was not able to determine available" \
1592                        "CHSCs due to no memory.\n");
1593                 return -ENOMEM;
1594         }
1595
1596         scsc_area->request.length = 0x0010;
1597         scsc_area->request.code = 0x0010;
1598
1599         result = chsc(scsc_area);
1600         if (result) {
1601                 printk(KERN_WARNING"cio: Was not able to determine " \
1602                        "available CHSCs, cc=%i.\n", result);
1603                 result = -EIO;
1604                 goto exit;
1605         }
1606
1607         if (scsc_area->response.code != 1) {
1608                 printk(KERN_WARNING"cio: Was not able to determine " \
1609                        "available CHSCs.\n");
1610                 result = -EIO;
1611                 goto exit;
1612         }
1613         memcpy(&css_general_characteristics, scsc_area->general_char,
1614                sizeof(css_general_characteristics));
1615         memcpy(&css_chsc_characteristics, scsc_area->chsc_char,
1616                sizeof(css_chsc_characteristics));
1617 exit:
1618         free_page ((unsigned long) scsc_area);
1619         return result;
1620 }
1621
1622 EXPORT_SYMBOL_GPL(css_general_characteristics);
1623 EXPORT_SYMBOL_GPL(css_chsc_characteristics);