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;
 204                 /* Allocate channel path structures, if needed. */
 205                 for (j = 0; j < 8; j++) {
 206                         chpid = sch->ssd_info.chpid[j];
 207                         if (chpid && (get_chp_status(chpid) < 0))
 208                             new_channel_path(chpid);
 209                 }
 210         }
 211         return ret;
 212 }
 213
 214 static int
 215 s390_subchannel_remove_chpid(struct device *dev, void *data)
 216 {
 217         int j;
 218         int mask;
 219         struct subchannel *sch;
 220         struct channel_path *chpid;
 221         struct schib schib;
 222
 223         sch = to_subchannel(dev);
 224         chpid = data;
 225         for (j = 0; j < 8; j++)
 226                 if (sch->schib.pmcw.chpid[j] == chpid->id)
 227                         break;
 228         if (j >= 8)
 229                 return 0;
 230
 231         mask = 0x80 >> j;
 232         spin_lock_irq(&sch->lock);
 233
 234         stsch(sch->schid, &schib);
 235         if (!schib.pmcw.dnv)
 236                 goto out_unreg;
 237         memcpy(&sch->schib, &schib, sizeof(struct schib));
 238         /* Check for single path devices. */
 239         if (sch->schib.pmcw.pim == 0x80)
 240                 goto out_unreg;
 241
 242         if ((sch->schib.scsw.actl & SCSW_ACTL_DEVACT) &&
 243             (sch->schib.scsw.actl & SCSW_ACTL_SCHACT) &&
 244             (sch->schib.pmcw.lpum == mask)) {
 245                 int cc;
 246
 247                 cc = cio_clear(sch);
 248                 if (cc == -ENODEV)
 249                         goto out_unreg;
 250                 /* Call handler. */
 251                 if (sch->driver && sch->driver->termination)
 252                         sch->driver->termination(&sch->dev);
 253                 goto out_unlock;
 254         }
 255
 256         /* trigger path verification. */
 257         if (sch->driver && sch->driver->verify)
 258                 sch->driver->verify(&sch->dev);
 259         else if (sch->vpm == mask)
 260                 goto out_unreg;
 261 out_unlock:
 262         spin_unlock_irq(&sch->lock);
 263         return 0;
 264 out_unreg:
 265         spin_unlock_irq(&sch->lock);
 266         sch->lpm = 0;
 267         if (css_enqueue_subchannel_slow(sch->schid)) {
 268                 css_clear_subchannel_slow_list();
 269                 need_rescan = 1;
 270         }
 271         return 0;
 272 }
 273
 274 static inline void
 275 s390_set_chpid_offline( __u8 chpid)
 276 {
 277         char dbf_txt[15];
 278         struct device *dev;
 279
 280         sprintf(dbf_txt, "chpr%x", chpid);
 281         CIO_TRACE_EVENT(2, dbf_txt);
 282
 283         if (get_chp_status(chpid) <= 0)
 284                 return;
 285         dev = get_device(&css[0]->chps[chpid]->dev);
 286         bus_for_each_dev(&css_bus_type, NULL, to_channelpath(dev),
 287                          s390_subchannel_remove_chpid);
 288
 289         if (need_rescan || css_slow_subchannels_exist())
 290                 queue_work(slow_path_wq, &slow_path_work);
 291         put_device(dev);
 292 }
 293
 294 struct res_acc_data {
 295         struct channel_path *chp;
 296         u32 fla_mask;
 297         u16 fla;
 298 };
 299
 300 static int
 301 s390_process_res_acc_sch(struct res_acc_data *res_data, struct subchannel *sch)
 302 {
 303         int found;
 304         int chp;
 305         int ccode;
 306
 307         found = 0;
 308         for (chp = 0; chp <= 7; chp++)
 309                 /*
 310                  * check if chpid is in information updated by ssd
 311                  */
 312                 if (sch->ssd_info.valid &&
 313                     sch->ssd_info.chpid[chp] == res_data->chp->id &&
 314                     (sch->ssd_info.fla[chp] & res_data->fla_mask)
 315                     == res_data->fla) {
 316                         found = 1;
 317                         break;
 318                 }
 319
 320         if (found == 0)
 321                 return 0;
 322
 323         /*
 324          * Do a stsch to update our subchannel structure with the
 325          * new path information and eventually check for logically
 326          * offline chpids.
 327          */
 328         ccode = stsch(sch->schid, &sch->schib);
 329         if (ccode > 0)
 330                 return 0;
 331
 332         return 0x80 >> chp;
 333 }
 334
 335 static inline int
 336 s390_process_res_acc_new_sch(struct subchannel_id schid)
 337 {
 338         struct schib schib;
 339         int ret;
 340         /*
 341          * We don't know the device yet, but since a path
 342          * may be available now to the device we'll have
 343          * to do recognition again.
 344          * Since we don't have any idea about which chpid
 345          * that beast may be on we'll have to do a stsch
 346          * on all devices, grr...
 347          */
 348         if (stsch_err(schid, &schib))
 349                 /* We're through */
 350                 return need_rescan ? -EAGAIN : -ENXIO;
 351
 352         /* Put it on the slow path. */
 353         ret = css_enqueue_subchannel_slow(schid);
 354         if (ret) {
 355                 css_clear_subchannel_slow_list();
 356                 need_rescan = 1;
 357                 return -EAGAIN;
 358         }
 359         return 0;
 360 }
 361
 362 static int
 363 __s390_process_res_acc(struct subchannel_id schid, void *data)
 364 {
 365         int chp_mask, old_lpm;
 366         struct res_acc_data *res_data;
 367         struct subchannel *sch;
 368
 369         res_data = (struct res_acc_data *)data;
 370         sch = get_subchannel_by_schid(schid);
 371         if (!sch)
 372                 /* Check if a subchannel is newly available. */
 373                 return s390_process_res_acc_new_sch(schid);
 374
 375         spin_lock_irq(&sch->lock);
 376
 377         chp_mask = s390_process_res_acc_sch(res_data, sch);
 378
 379         if (chp_mask == 0) {
 380                 spin_unlock_irq(&sch->lock);
 381                 return 0;
 382         }
 383         old_lpm = sch->lpm;
 384         sch->lpm = ((sch->schib.pmcw.pim &
 385                      sch->schib.pmcw.pam &
 386                      sch->schib.pmcw.pom)
 387                     | chp_mask) & sch->opm;
 388         if (!old_lpm && sch->lpm)
 389                 device_trigger_reprobe(sch);
 390         else if (sch->driver && sch->driver->verify)
 391                 sch->driver->verify(&sch->dev);
 392
 393         spin_unlock_irq(&sch->lock);
 394         put_device(&sch->dev);
 395         return (res_data->fla_mask == 0xffff) ? -ENODEV : 0;
 396 }
 397
 398
 399 static int
 400 s390_process_res_acc (struct res_acc_data *res_data)
 401 {
 402         int rc;
 403         char dbf_txt[15];
 404
 405         sprintf(dbf_txt, "accpr%x", res_data->chp->id);
 406         CIO_TRACE_EVENT( 2, dbf_txt);
 407         if (res_data->fla != 0) {
 408                 sprintf(dbf_txt, "fla%x", res_data->fla);
 409                 CIO_TRACE_EVENT( 2, dbf_txt);
 410         }
 411
 412         /*
 413          * I/O resources may have become accessible.
 414          * Scan through all subchannels that may be concerned and
 415          * do a validation on those.
 416          * The more information we have (info), the less scanning
 417          * will we have to do.
 418          */
 419         rc = for_each_subchannel(__s390_process_res_acc, res_data);
 420         if (css_slow_subchannels_exist())
 421                 rc = -EAGAIN;
 422         else if (rc != -EAGAIN)
 423                 rc = 0;
 424         return rc;
 425 }
 426
 427 static int
 428 __get_chpid_from_lir(void *data)
 429 {
 430         struct lir {
 431                 u8  iq;
 432                 u8  ic;
 433                 u16 sci;
 434                 /* incident-node descriptor */
 435                 u32 indesc[28];
 436                 /* attached-node descriptor */
 437                 u32 andesc[28];
 438                 /* incident-specific information */
 439                 u32 isinfo[28];
 440         } *lir;
 441
 442         lir = (struct lir*) data;
 443         if (!(lir->iq&0x80))
 444                 /* NULL link incident record */
 445                 return -EINVAL;
 446         if (!(lir->indesc[0]&0xc0000000))
 447                 /* node descriptor not valid */
 448                 return -EINVAL;
 449         if (!(lir->indesc[0]&0x10000000))
 450                 /* don't handle device-type nodes - FIXME */
 451                 return -EINVAL;
 452         /* Byte 3 contains the chpid. Could also be CTCA, but we don't care */
 453
 454         return (u16) (lir->indesc[0]&0x000000ff);
 455 }
 456
 457 int
 458 chsc_process_crw(void)
 459 {
 460         int chpid, ret;
 461         struct res_acc_data res_data;
 462         struct {
 463                 struct chsc_header request;
 464                 u32 reserved1;
 465                 u32 reserved2;
 466                 u32 reserved3;
 467                 struct chsc_header response;
 468                 u32 reserved4;
 469                 u8  flags;
 470                 u8  vf;         /* validity flags */
 471                 u8  rs;         /* reporting source */
 472                 u8  cc;         /* content code */
 473                 u16 fla;        /* full link address */
 474                 u16 rsid;       /* reporting source id */
 475                 u32 reserved5;
 476                 u32 reserved6;
 477                 u32 ccdf[96];   /* content-code dependent field */
 478                 /* ccdf has to be big enough for a link-incident record */
 479         } *sei_area;
 480
 481         if (!sei_page)
 482                 return 0;
 483         /*
 484          * build the chsc request block for store event information
 485          * and do the call
 486          * This function is only called by the machine check handler thread,
 487          * so we don't need locking for the sei_page.
 488          */
 489         sei_area = sei_page;
 490
 491         CIO_TRACE_EVENT( 2, "prcss");
 492         ret = 0;
 493         do {
 494                 int ccode, status;
 495                 struct device *dev;
 496                 memset(sei_area, 0, sizeof(*sei_area));
 497                 memset(&res_data, 0, sizeof(struct res_acc_data));
 498                 sei_area->request.length = 0x0010;
 499                 sei_area->request.code = 0x000e;
 500
 501                 ccode = chsc(sei_area);
 502                 if (ccode > 0)
 503                         return 0;
 504
 505                 switch (sei_area->response.code) {
 506                         /* for debug purposes, check for problems */
 507                 case 0x0001:
 508                         CIO_CRW_EVENT(4, "chsc_process_crw: event information "
 509                                         "successfully stored\n");
 510                         break; /* everything ok */
 511                 case 0x0002:
 512                         CIO_CRW_EVENT(2,
 513                                       "chsc_process_crw: invalid command!\n");
 514                         return 0;
 515                 case 0x0003:
 516                         CIO_CRW_EVENT(2, "chsc_process_crw: error in chsc "
 517                                       "request block!\n");
 518                         return 0;
 519                 case 0x0005:
 520                         CIO_CRW_EVENT(2, "chsc_process_crw: no event "
 521                                       "information stored\n");
 522                         return 0;
 523                 default:
 524                         CIO_CRW_EVENT(2, "chsc_process_crw: chsc response %d\n",
 525                                       sei_area->response.code);
 526                         return 0;
 527                 }
 528
 529                 /* Check if we might have lost some information. */
 530                 if (sei_area->flags & 0x40)
 531                         CIO_CRW_EVENT(2, "chsc_process_crw: Event information "
 532                                        "has been lost due to overflow!\n");
 533
 534                 if (sei_area->rs != 4) {
 535                         CIO_CRW_EVENT(2, "chsc_process_crw: reporting source "
 536                                       "(%04X) isn't a chpid!\n",
 537                                       sei_area->rsid);
 538                         continue;
 539                 }
 540
 541                 /* which kind of information was stored? */
 542                 switch (sei_area->cc) {
 543                 case 1: /* link incident*/
 544                         CIO_CRW_EVENT(4, "chsc_process_crw: "
 545                                       "channel subsystem reports link incident,"
 546                                       " reporting source is chpid %x\n",
 547                                       sei_area->rsid);
 548                         chpid = __get_chpid_from_lir(sei_area->ccdf);
 549                         if (chpid < 0)
 550                                 CIO_CRW_EVENT(4, "%s: Invalid LIR, skipping\n",
 551                                               __FUNCTION__);
 552                         else
 553                                 s390_set_chpid_offline(chpid);
 554                         break;
 555
 556                 case 2: /* i/o resource accessibiliy */
 557                         CIO_CRW_EVENT(4, "chsc_process_crw: "
 558                                       "channel subsystem reports some I/O "
 559                                       "devices may have become accessible\n");
 560                         pr_debug("Data received after sei: \n");
 561                         pr_debug("Validity flags: %x\n", sei_area->vf);
 562
 563                         /* allocate a new channel path structure, if needed */
 564                         status = get_chp_status(sei_area->rsid);
 565                         if (status < 0)
 566                                 new_channel_path(sei_area->rsid);
 567                         else if (!status)
 568                                 break;
 569                         dev = get_device(&css[0]->chps[sei_area->rsid]->dev);
 570                         res_data.chp = to_channelpath(dev);
 571                         pr_debug("chpid: %x", sei_area->rsid);
 572                         if ((sei_area->vf & 0xc0) != 0) {
 573                                 res_data.fla = sei_area->fla;
 574                                 if ((sei_area->vf & 0xc0) == 0xc0) {
 575                                         pr_debug(" full link addr: %x",
 576                                                  sei_area->fla);
 577                                         res_data.fla_mask = 0xffff;
 578                                 } else {
 579                                         pr_debug(" link addr: %x",
 580                                                  sei_area->fla);
 581                                         res_data.fla_mask = 0xff00;
 582                                 }
 583                         }
 584                         ret = s390_process_res_acc(&res_data);
 585                         pr_debug("\n\n");
 586                         put_device(dev);
 587                         break;
 588
 589                 default: /* other stuff */
 590                         CIO_CRW_EVENT(4, "chsc_process_crw: event %d\n",
 591                                       sei_area->cc);
 592                         break;
 593                 }
 594         } while (sei_area->flags & 0x80);
 595         return ret;
 596 }
 597
 598 static inline int
 599 __chp_add_new_sch(struct subchannel_id schid)
 600 {
 601         struct schib schib;
 602         int ret;
 603
 604         if (stsch(schid, &schib))
 605                 /* We're through */
 606                 return need_rescan ? -EAGAIN : -ENXIO;
 607
 608         /* Put it on the slow path. */
 609         ret = css_enqueue_subchannel_slow(schid);
 610         if (ret) {
 611                 css_clear_subchannel_slow_list();
 612                 need_rescan = 1;
 613                 return -EAGAIN;
 614         }
 615         return 0;
 616 }
 617
 618
 619 static int
 620 __chp_add(struct subchannel_id schid, void *data)
 621 {
 622         int i;
 623         struct channel_path *chp;
 624         struct subchannel *sch;
 625
 626         chp = (struct channel_path *)data;
 627         sch = get_subchannel_by_schid(schid);
 628         if (!sch)
 629                 /* Check if the subchannel is now available. */
 630                 return __chp_add_new_sch(schid);
 631         spin_lock_irq(&sch->lock);
 632         for (i=0; i<8; i++)
 633                 if (sch->schib.pmcw.chpid[i] == chp->id) {
 634                         if (stsch(sch->schid, &sch->schib) != 0) {
 635                                 /* Endgame. */
 636                                 spin_unlock_irq(&sch->lock);
 637                                 return -ENXIO;
 638                         }
 639                         break;
 640                 }
 641         if (i==8) {
 642                 spin_unlock_irq(&sch->lock);
 643                 return 0;
 644         }
 645         sch->lpm = ((sch->schib.pmcw.pim &
 646                      sch->schib.pmcw.pam &
 647                      sch->schib.pmcw.pom)
 648                     | 0x80 >> i) & sch->opm;
 649
 650         if (sch->driver && sch->driver->verify)
 651                 sch->driver->verify(&sch->dev);
 652
 653         spin_unlock_irq(&sch->lock);
 654         put_device(&sch->dev);
 655         return 0;
 656 }
 657
 658 static int
 659 chp_add(int chpid)
 660 {
 661         int rc;
 662         char dbf_txt[15];
 663         struct device *dev;
 664
 665         if (!get_chp_status(chpid))
 666                 return 0; /* no need to do the rest */
 667
 668         sprintf(dbf_txt, "cadd%x", chpid);
 669         CIO_TRACE_EVENT(2, dbf_txt);
 670
 671         dev = get_device(&css[0]->chps[chpid]->dev);
 672         rc = for_each_subchannel(__chp_add, to_channelpath(dev));
 673         if (css_slow_subchannels_exist())
 674                 rc = -EAGAIN;
 675         if (rc != -EAGAIN)
 676                 rc = 0;
 677         put_device(dev);
 678         return rc;
 679 }
 680
 681 /*
 682  * Handling of crw machine checks with channel path source.
 683  */
 684 int
 685 chp_process_crw(int chpid, int on)
 686 {
 687         if (on == 0) {
 688                 /* Path has gone. We use the link incident routine.*/
 689                 s390_set_chpid_offline(chpid);
 690                 return 0; /* De-register is async anyway. */
 691         }
 692         /*
 693          * Path has come. Allocate a new channel path structure,
 694          * if needed.
 695          */
 696         if (get_chp_status(chpid) < 0)
 697                 new_channel_path(chpid);
 698         /* Avoid the extra overhead in process_rec_acc. */
 699         return chp_add(chpid);
 700 }
 701
 702 static inline int
 703 __check_for_io_and_kill(struct subchannel *sch, int index)
 704 {
 705         int cc;
 706
 707         if (!device_is_online(sch))
 708                 /* cio could be doing I/O. */
 709                 return 0;
 710         cc = stsch(sch->schid, &sch->schib);
 711         if (cc)
 712                 return 0;
 713         if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index)) {
 714                 device_set_waiting(sch);
 715                 return 1;
 716         }
 717         return 0;
 718 }
 719
 720 static inline void
 721 __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
 722 {
 723         int chp, old_lpm;
 724         unsigned long flags;
 725
 726         if (!sch->ssd_info.valid)
 727                 return;
 728
 729         spin_lock_irqsave(&sch->lock, flags);
 730         old_lpm = sch->lpm;
 731         for (chp = 0; chp < 8; chp++) {
 732                 if (sch->ssd_info.chpid[chp] != chpid)
 733                         continue;
 734
 735                 if (on) {
 736                         sch->opm |= (0x80 >> chp);
 737                         sch->lpm |= (0x80 >> chp);
 738                         if (!old_lpm)
 739                                 device_trigger_reprobe(sch);
 740                         else if (sch->driver && sch->driver->verify)
 741                                 sch->driver->verify(&sch->dev);
 742                 } else {
 743                         sch->opm &= ~(0x80 >> chp);
 744                         sch->lpm &= ~(0x80 >> chp);
 745                         /*
 746                          * Give running I/O a grace period in which it
 747                          * can successfully terminate, even using the
 748                          * just varied off path. Then kill it.
 749                          */
 750                         if (!__check_for_io_and_kill(sch, chp) && !sch->lpm) {
 751                                 if (css_enqueue_subchannel_slow(sch->schid)) {
 752                                         css_clear_subchannel_slow_list();
 753                                         need_rescan = 1;
 754                                 }
 755                         } else if (sch->driver && sch->driver->verify)
 756                                 sch->driver->verify(&sch->dev);
 757                 }
 758                 break;
 759         }
 760         spin_unlock_irqrestore(&sch->lock, flags);
 761 }
 762
 763 static int
 764 s390_subchannel_vary_chpid_off(struct device *dev, void *data)
 765 {
 766         struct subchannel *sch;
 767         __u8 *chpid;
 768
 769         sch = to_subchannel(dev);
 770         chpid = data;
 771
 772         __s390_subchannel_vary_chpid(sch, *chpid, 0);
 773         return 0;
 774 }
 775
 776 static int
 777 s390_subchannel_vary_chpid_on(struct device *dev, void *data)
 778 {
 779         struct subchannel *sch;
 780         __u8 *chpid;
 781
 782         sch = to_subchannel(dev);
 783         chpid = data;
 784
 785         __s390_subchannel_vary_chpid(sch, *chpid, 1);
 786         return 0;
 787 }
 788
 789 static int
 790 __s390_vary_chpid_on(struct subchannel_id schid, void *data)
 791 {
 792         struct schib schib;
 793         struct subchannel *sch;
 794
 795         sch = get_subchannel_by_schid(schid);
 796         if (sch) {
 797                 put_device(&sch->dev);
 798                 return 0;
 799         }
 800         if (stsch_err(schid, &schib))
 801                 /* We're through */
 802                 return -ENXIO;
 803         /* Put it on the slow path. */
 804         if (css_enqueue_subchannel_slow(schid)) {
 805                 css_clear_subchannel_slow_list();
 806                 need_rescan = 1;
 807                 return -EAGAIN;
 808         }
 809         return 0;
 810 }
 811
 812 /*
 813  * Function: s390_vary_chpid
 814  * Varies the specified chpid online or offline
 815  */
 816 static int
 817 s390_vary_chpid( __u8 chpid, int on)
 818 {
 819         char dbf_text[15];
 820         int status;
 821
 822         sprintf(dbf_text, on?"varyon%x":"varyoff%x", chpid);
 823         CIO_TRACE_EVENT( 2, dbf_text);
 824
 825         status = get_chp_status(chpid);
 826         if (status < 0) {
 827                 printk(KERN_ERR "Can't vary unknown chpid %02X\n", chpid);
 828                 return -EINVAL;
 829         }
 830
 831         if (!on && !status) {
 832                 printk(KERN_ERR "chpid %x is already offline\n", chpid);
 833                 return -EINVAL;
 834         }
 835
 836         set_chp_logically_online(chpid, on);
 837
 838         /*
 839          * Redo PathVerification on the devices the chpid connects to
 840          */
 841
 842         bus_for_each_dev(&css_bus_type, NULL, &chpid, on ?
 843                          s390_subchannel_vary_chpid_on :
 844                          s390_subchannel_vary_chpid_off);
 845         if (on)
 846                 /* Scan for new devices on varied on path. */
 847                 for_each_subchannel(__s390_vary_chpid_on, NULL);
 848         if (need_rescan || css_slow_subchannels_exist())
 849                 queue_work(slow_path_wq, &slow_path_work);
 850         return 0;
 851 }
 852
 853 /*
 854  * Channel measurement related functions
 855  */
 856 static ssize_t
 857 chp_measurement_chars_read(struct kobject *kobj, char *buf, loff_t off,
 858                            size_t count)
 859 {
 860         struct channel_path *chp;
 861         unsigned int size;
 862
 863         chp = to_channelpath(container_of(kobj, struct device, kobj));
 864         if (!chp->cmg_chars)
 865                 return 0;
 866
 867         size = sizeof(struct cmg_chars);
 868
 869         if (off > size)
 870                 return 0;
 871         if (off + count > size)
 872                 count = size - off;
 873         memcpy(buf, chp->cmg_chars + off, count);
 874         return count;
 875 }
 876
 877 static struct bin_attribute chp_measurement_chars_attr = {
 878         .attr = {
 879                 .name = "measurement_chars",
 880                 .mode = S_IRUSR,
 881                 .owner = THIS_MODULE,
 882         },
 883         .size = sizeof(struct cmg_chars),
 884         .read = chp_measurement_chars_read,
 885 };
 886
 887 static void
 888 chp_measurement_copy_block(struct cmg_entry *buf,
 889                            struct channel_subsystem *css, int chpid)
 890 {
 891         void *area;
 892         struct cmg_entry *entry, reference_buf;
 893         int idx;
 894
 895         if (chpid < 128) {
 896                 area = css->cub_addr1;
 897                 idx = chpid;
 898         } else {
 899                 area = css->cub_addr2;
 900                 idx = chpid - 128;
 901         }
 902         entry = area + (idx * sizeof(struct cmg_entry));
 903         do {
 904                 memcpy(buf, entry, sizeof(*entry));
 905                 memcpy(&reference_buf, entry, sizeof(*entry));
 906         } while (reference_buf.values[0] != buf->values[0]);
 907 }
 908
 909 static ssize_t
 910 chp_measurement_read(struct kobject *kobj, char *buf, loff_t off, size_t count)
 911 {
 912         struct channel_path *chp;
 913         struct channel_subsystem *css;
 914         unsigned int size;
 915
 916         chp = to_channelpath(container_of(kobj, struct device, kobj));
 917         css = to_css(chp->dev.parent);
 918
 919         size = sizeof(struct cmg_entry);
 920
 921         /* Only allow single reads. */
 922         if (off || count < size)
 923                 return 0;
 924         chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->id);
 925         count = size;
 926         return count;
 927 }
 928
 929 static struct bin_attribute chp_measurement_attr = {
 930         .attr = {
 931                 .name = "measurement",
 932                 .mode = S_IRUSR,
 933                 .owner = THIS_MODULE,
 934         },
 935         .size = sizeof(struct cmg_entry),
 936         .read = chp_measurement_read,
 937 };
 938
 939 static void
 940 chsc_remove_chp_cmg_attr(struct channel_path *chp)
 941 {
 942         sysfs_remove_bin_file(&chp->dev.kobj, &chp_measurement_chars_attr);
 943         sysfs_remove_bin_file(&chp->dev.kobj, &chp_measurement_attr);
 944 }
 945
 946 static int
 947 chsc_add_chp_cmg_attr(struct channel_path *chp)
 948 {
 949         int ret;
 950
 951         ret = sysfs_create_bin_file(&chp->dev.kobj,
 952                                     &chp_measurement_chars_attr);
 953         if (ret)
 954                 return ret;
 955         ret = sysfs_create_bin_file(&chp->dev.kobj, &chp_measurement_attr);
 956         if (ret)
 957                 sysfs_remove_bin_file(&chp->dev.kobj,
 958                                       &chp_measurement_chars_attr);
 959         return ret;
 960 }
 961
 962 static void
 963 chsc_remove_cmg_attr(struct channel_subsystem *css)
 964 {
 965         int i;
 966
 967         for (i = 0; i <= __MAX_CHPID; i++) {
 968                 if (!css->chps[i])
 969                         continue;
 970                 chsc_remove_chp_cmg_attr(css->chps[i]);
 971         }
 972 }
 973
 974 static int
 975 chsc_add_cmg_attr(struct channel_subsystem *css)
 976 {
 977         int i, ret;
 978
 979         ret = 0;
 980         for (i = 0; i <= __MAX_CHPID; i++) {
 981                 if (!css->chps[i])
 982                         continue;
 983                 ret = chsc_add_chp_cmg_attr(css->chps[i]);
 984                 if (ret)
 985                         goto cleanup;
 986         }
 987         return ret;
 988 cleanup:
 989         for (--i; i >= 0; i--) {
 990                 if (!css->chps[i])
 991                         continue;
 992                 chsc_remove_chp_cmg_attr(css->chps[i]);
 993         }
 994         return ret;
 995 }
 996
 997
 998 static int
 999 __chsc_do_secm(struct channel_subsystem *css, int enable, void *page)
1000 {
1001         struct {
1002                 struct chsc_header request;
1003                 u32 operation_code : 2;
1004                 u32 : 30;
1005                 u32 key : 4;
1006                 u32 : 28;
1007                 u32 zeroes1;
1008                 u32 cub_addr1;
1009                 u32 zeroes2;
1010                 u32 cub_addr2;
1011                 u32 reserved[13];
1012                 struct chsc_header response;
1013                 u32 status : 8;
1014                 u32 : 4;
1015                 u32 fmt : 4;
1016                 u32 : 16;
1017         } *secm_area;
1018         int ret, ccode;
1019
1020         secm_area = page;
1021         secm_area->request.length = 0x0050;
1022         secm_area->request.code = 0x0016;
1023
1024         secm_area->key = PAGE_DEFAULT_KEY;
1025         secm_area->cub_addr1 = (u64)(unsigned long)css->cub_addr1;
1026         secm_area->cub_addr2 = (u64)(unsigned long)css->cub_addr2;
1027
1028         secm_area->operation_code = enable ? 0 : 1;
1029
1030         ccode = chsc(secm_area);
1031         if (ccode > 0)
1032                 return (ccode == 3) ? -ENODEV : -EBUSY;
1033
1034         switch (secm_area->response.code) {
1035         case 0x0001: /* Success. */
1036                 ret = 0;
1037                 break;
1038         case 0x0003: /* Invalid block. */
1039         case 0x0007: /* Invalid format. */
1040         case 0x0008: /* Other invalid block. */
1041                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1042                 ret = -EINVAL;
1043                 break;
1044         case 0x0004: /* Command not provided in model. */
1045                 CIO_CRW_EVENT(2, "Model does not provide secm\n");
1046                 ret = -EOPNOTSUPP;
1047                 break;
1048         case 0x0102: /* cub adresses incorrect */
1049                 CIO_CRW_EVENT(2, "Invalid addresses in chsc request block\n");
1050                 ret = -EINVAL;
1051                 break;
1052         case 0x0103: /* key error */
1053                 CIO_CRW_EVENT(2, "Access key error in secm\n");
1054                 ret = -EINVAL;
1055                 break;
1056         case 0x0105: /* error while starting */
1057                 CIO_CRW_EVENT(2, "Error while starting channel measurement\n");
1058                 ret = -EIO;
1059                 break;
1060         default:
1061                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1062                               secm_area->response.code);
1063                 ret = -EIO;
1064         }
1065         return ret;
1066 }
1067
1068 int
1069 chsc_secm(struct channel_subsystem *css, int enable)
1070 {
1071         void  *secm_area;
1072         int ret;
1073
1074         secm_area = (void *)get_zeroed_page(GFP_KERNEL |  GFP_DMA);
1075         if (!secm_area)
1076                 return -ENOMEM;
1077
1078         mutex_lock(&css->mutex);
1079         if (enable && !css->cm_enabled) {
1080                 css->cub_addr1 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1081                 css->cub_addr2 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1082                 if (!css->cub_addr1 || !css->cub_addr2) {
1083                         free_page((unsigned long)css->cub_addr1);
1084                         free_page((unsigned long)css->cub_addr2);
1085                         free_page((unsigned long)secm_area);
1086                         mutex_unlock(&css->mutex);
1087                         return -ENOMEM;
1088                 }
1089         }
1090         ret = __chsc_do_secm(css, enable, secm_area);
1091         if (!ret) {
1092                 css->cm_enabled = enable;
1093                 if (css->cm_enabled) {
1094                         ret = chsc_add_cmg_attr(css);
1095                         if (ret) {
1096                                 memset(secm_area, 0, PAGE_SIZE);
1097                                 __chsc_do_secm(css, 0, secm_area);
1098                                 css->cm_enabled = 0;
1099                         }
1100                 } else
1101                         chsc_remove_cmg_attr(css);
1102         }
1103         if (enable && !css->cm_enabled) {
1104                 free_page((unsigned long)css->cub_addr1);
1105                 free_page((unsigned long)css->cub_addr2);
1106         }
1107         mutex_unlock(&css->mutex);
1108         free_page((unsigned long)secm_area);
1109         return ret;
1110 }
1111
1112 /*
1113  * Files for the channel path entries.
1114  */
1115 static ssize_t
1116 chp_status_show(struct device *dev, struct device_attribute *attr, char *buf)
1117 {
1118         struct channel_path *chp = container_of(dev, struct channel_path, dev);
1119
1120         if (!chp)
1121                 return 0;
1122         return (get_chp_status(chp->id) ? sprintf(buf, "online\n") :
1123                 sprintf(buf, "offline\n"));
1124 }
1125
1126 static ssize_t
1127 chp_status_write(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
1128 {
1129         struct channel_path *cp = container_of(dev, struct channel_path, dev);
1130         char cmd[10];
1131         int num_args;
1132         int error;
1133
1134         num_args = sscanf(buf, "%5s", cmd);
1135         if (!num_args)
1136                 return count;
1137
1138         if (!strnicmp(cmd, "on", 2))
1139                 error = s390_vary_chpid(cp->id, 1);
1140         else if (!strnicmp(cmd, "off", 3))
1141                 error = s390_vary_chpid(cp->id, 0);
1142         else
1143                 error = -EINVAL;
1144
1145         return error < 0 ? error : count;
1146
1147 }
1148
1149 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
1150
1151 static ssize_t
1152 chp_type_show(struct device *dev, struct device_attribute *attr, char *buf)
1153 {
1154         struct channel_path *chp = container_of(dev, struct channel_path, dev);
1155
1156         if (!chp)
1157                 return 0;
1158         return sprintf(buf, "%x\n", chp->desc.desc);
1159 }
1160
1161 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
1162
1163 static ssize_t
1164 chp_cmg_show(struct device *dev, struct device_attribute *attr, char *buf)
1165 {
1166         struct channel_path *chp = to_channelpath(dev);
1167
1168         if (!chp)
1169                 return 0;
1170         if (chp->cmg == -1) /* channel measurements not available */
1171                 return sprintf(buf, "unknown\n");
1172         return sprintf(buf, "%x\n", chp->cmg);
1173 }
1174
1175 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
1176
1177 static ssize_t
1178 chp_shared_show(struct device *dev, struct device_attribute *attr, char *buf)
1179 {
1180         struct channel_path *chp = to_channelpath(dev);
1181
1182         if (!chp)
1183                 return 0;
1184         if (chp->shared == -1) /* channel measurements not available */
1185                 return sprintf(buf, "unknown\n");
1186         return sprintf(buf, "%x\n", chp->shared);
1187 }
1188
1189 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
1190
1191 static struct attribute * chp_attrs[] = {
1192         &dev_attr_status.attr,
1193         &dev_attr_type.attr,
1194         &dev_attr_cmg.attr,
1195         &dev_attr_shared.attr,
1196         NULL,
1197 };
1198
1199 static struct attribute_group chp_attr_group = {
1200         .attrs = chp_attrs,
1201 };
1202
1203 static void
1204 chp_release(struct device *dev)
1205 {
1206         struct channel_path *cp;
1207
1208         cp = container_of(dev, struct channel_path, dev);
1209         kfree(cp);
1210 }
1211
1212 static int
1213 chsc_determine_channel_path_description(int chpid,
1214                                         struct channel_path_desc *desc)
1215 {
1216         int ccode, ret;
1217
1218         struct {
1219                 struct chsc_header request;
1220                 u32 : 24;
1221                 u32 first_chpid : 8;
1222                 u32 : 24;
1223                 u32 last_chpid : 8;
1224                 u32 zeroes1;
1225                 struct chsc_header response;
1226                 u32 zeroes2;
1227                 struct channel_path_desc desc;
1228         } *scpd_area;
1229
1230         scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1231         if (!scpd_area)
1232                 return -ENOMEM;
1233
1234         scpd_area->request.length = 0x0010;
1235         scpd_area->request.code = 0x0002;
1236
1237         scpd_area->first_chpid = chpid;
1238         scpd_area->last_chpid = chpid;
1239
1240         ccode = chsc(scpd_area);
1241         if (ccode > 0) {
1242                 ret = (ccode == 3) ? -ENODEV : -EBUSY;
1243                 goto out;
1244         }
1245
1246         switch (scpd_area->response.code) {
1247         case 0x0001: /* Success. */
1248                 memcpy(desc, &scpd_area->desc,
1249                        sizeof(struct channel_path_desc));
1250                 ret = 0;
1251                 break;
1252         case 0x0003: /* Invalid block. */
1253         case 0x0007: /* Invalid format. */
1254         case 0x0008: /* Other invalid block. */
1255                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1256                 ret = -EINVAL;
1257                 break;
1258         case 0x0004: /* Command not provided in model. */
1259                 CIO_CRW_EVENT(2, "Model does not provide scpd\n");
1260                 ret = -EOPNOTSUPP;
1261                 break;
1262         default:
1263                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1264                               scpd_area->response.code);
1265                 ret = -EIO;
1266         }
1267 out:
1268         free_page((unsigned long)scpd_area);
1269         return ret;
1270 }
1271
1272 static void
1273 chsc_initialize_cmg_chars(struct channel_path *chp, u8 cmcv,
1274                           struct cmg_chars *chars)
1275 {
1276         switch (chp->cmg) {
1277         case 2:
1278         case 3:
1279                 chp->cmg_chars = kmalloc(sizeof(struct cmg_chars),
1280                                          GFP_KERNEL);
1281                 if (chp->cmg_chars) {
1282                         int i, mask;
1283                         struct cmg_chars *cmg_chars;
1284
1285                         cmg_chars = chp->cmg_chars;
1286                         for (i = 0; i < NR_MEASUREMENT_CHARS; i++) {
1287                                 mask = 0x80 >> (i + 3);
1288                                 if (cmcv & mask)
1289                                         cmg_chars->values[i] = chars->values[i];
1290                                 else
1291                                         cmg_chars->values[i] = 0;
1292                         }
1293                 }
1294                 break;
1295         default:
1296                 /* No cmg-dependent data. */
1297                 break;
1298         }
1299 }
1300
1301 static int
1302 chsc_get_channel_measurement_chars(struct channel_path *chp)
1303 {
1304         int ccode, ret;
1305
1306         struct {
1307                 struct chsc_header request;
1308                 u32 : 24;
1309                 u32 first_chpid : 8;
1310                 u32 : 24;
1311                 u32 last_chpid : 8;
1312                 u32 zeroes1;
1313                 struct chsc_header response;
1314                 u32 zeroes2;
1315                 u32 not_valid : 1;
1316                 u32 shared : 1;
1317                 u32 : 22;
1318                 u32 chpid : 8;
1319                 u32 cmcv : 5;
1320                 u32 : 11;
1321                 u32 cmgq : 8;
1322                 u32 cmg : 8;
1323                 u32 zeroes3;
1324                 u32 data[NR_MEASUREMENT_CHARS];
1325         } *scmc_area;
1326
1327         scmc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1328         if (!scmc_area)
1329                 return -ENOMEM;
1330
1331         scmc_area->request.length = 0x0010;
1332         scmc_area->request.code = 0x0022;
1333
1334         scmc_area->first_chpid = chp->id;
1335         scmc_area->last_chpid = chp->id;
1336
1337         ccode = chsc(scmc_area);
1338         if (ccode > 0) {
1339                 ret = (ccode == 3) ? -ENODEV : -EBUSY;
1340                 goto out;
1341         }
1342
1343         switch (scmc_area->response.code) {
1344         case 0x0001: /* Success. */
1345                 if (!scmc_area->not_valid) {
1346                         chp->cmg = scmc_area->cmg;
1347                         chp->shared = scmc_area->shared;
1348                         chsc_initialize_cmg_chars(chp, scmc_area->cmcv,
1349                                                   (struct cmg_chars *)
1350                                                   &scmc_area->data);
1351                 } else {
1352                         chp->cmg = -1;
1353                         chp->shared = -1;
1354                 }
1355                 ret = 0;
1356                 break;
1357         case 0x0003: /* Invalid block. */
1358         case 0x0007: /* Invalid format. */
1359         case 0x0008: /* Invalid bit combination. */
1360                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
1361                 ret = -EINVAL;
1362                 break;
1363         case 0x0004: /* Command not provided. */
1364                 CIO_CRW_EVENT(2, "Model does not provide scmc\n");
1365                 ret = -EOPNOTSUPP;
1366                 break;
1367         default:
1368                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1369                               scmc_area->response.code);
1370                 ret = -EIO;
1371         }
1372 out:
1373         free_page((unsigned long)scmc_area);
1374         return ret;
1375 }
1376
1377 /*
1378  * Entries for chpids on the system bus.
1379  * This replaces /proc/chpids.
1380  */
1381 static int
1382 new_channel_path(int chpid)
1383 {
1384         struct channel_path *chp;
1385         int ret;
1386
1387         chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
1388         if (!chp)
1389                 return -ENOMEM;
1390
1391         /* fill in status, etc. */
1392         chp->id = chpid;
1393         chp->state = 1;
1394         chp->dev.parent = &css[0]->device;
1395         chp->dev.release = chp_release;
1396         snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp0.%x", chpid);
1397
1398         /* Obtain channel path description and fill it in. */
1399         ret = chsc_determine_channel_path_description(chpid, &chp->desc);
1400         if (ret)
1401                 goto out_free;
1402         /* Get channel-measurement characteristics. */
1403         if (css_characteristics_avail && css_chsc_characteristics.scmc
1404             && css_chsc_characteristics.secm) {
1405                 ret = chsc_get_channel_measurement_chars(chp);
1406                 if (ret)
1407                         goto out_free;
1408         } else {
1409                 static int msg_done;
1410
1411                 if (!msg_done) {
1412                         printk(KERN_WARNING "cio: Channel measurements not "
1413                                "available, continuing.\n");
1414                         msg_done = 1;
1415                 }
1416                 chp->cmg = -1;
1417         }
1418
1419         /* make it known to the system */
1420         ret = device_register(&chp->dev);
1421         if (ret) {
1422                 printk(KERN_WARNING "%s: could not register %02x\n",
1423                        __func__, chpid);
1424                 goto out_free;
1425         }
1426         ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
1427         if (ret) {
1428                 device_unregister(&chp->dev);
1429                 goto out_free;
1430         }
1431         mutex_lock(&css[0]->mutex);
1432         if (css[0]->cm_enabled) {
1433                 ret = chsc_add_chp_cmg_attr(chp);
1434                 if (ret) {
1435                         sysfs_remove_group(&chp->dev.kobj, &chp_attr_group);
1436                         device_unregister(&chp->dev);
1437                         mutex_unlock(&css[0]->mutex);
1438                         goto out_free;
1439                 }
1440         }
1441         css[0]->chps[chpid] = chp;
1442         mutex_unlock(&css[0]->mutex);
1443         return ret;
1444 out_free:
1445         kfree(chp);
1446         return ret;
1447 }
1448
1449 void *
1450 chsc_get_chp_desc(struct subchannel *sch, int chp_no)
1451 {
1452         struct channel_path *chp;
1453         struct channel_path_desc *desc;
1454
1455         chp = css[0]->chps[sch->schib.pmcw.chpid[chp_no]];
1456         if (!chp)
1457                 return NULL;
1458         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
1459         if (!desc)
1460                 return NULL;
1461         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
1462         return desc;
1463 }
1464
1465 static int reset_channel_path(struct channel_path *chp)
1466 {
1467         int cc;
1468
1469         cc = rchp(chp->id);
1470         switch (cc) {
1471         case 0:
1472                 return 0;
1473         case 2:
1474                 return -EBUSY;
1475         default:
1476                 return -ENODEV;
1477         }
1478 }
1479
1480 static void reset_channel_paths_css(struct channel_subsystem *css)
1481 {
1482         int i;
1483
1484         for (i = 0; i <= __MAX_CHPID; i++) {
1485                 if (css->chps[i])
1486                         reset_channel_path(css->chps[i]);
1487         }
1488 }
1489
1490 void cio_reset_channel_paths(void)
1491 {
1492         int i;
1493
1494         for (i = 0; i <= __MAX_CSSID; i++) {
1495                 if (css[i] && css[i]->valid)
1496                         reset_channel_paths_css(css[i]);
1497         }
1498 }
1499
1500 static int __init
1501 chsc_alloc_sei_area(void)
1502 {
1503         sei_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1504         if (!sei_page)
1505                 printk(KERN_WARNING"Can't allocate page for processing of " \
1506                        "chsc machine checks!\n");
1507         return (sei_page ? 0 : -ENOMEM);
1508 }
1509
1510 int __init
1511 chsc_enable_facility(int operation_code)
1512 {
1513         int ret;
1514         struct {
1515                 struct chsc_header request;
1516                 u8 reserved1:4;
1517                 u8 format:4;
1518                 u8 reserved2;
1519                 u16 operation_code;
1520                 u32 reserved3;
1521                 u32 reserved4;
1522                 u32 operation_data_area[252];
1523                 struct chsc_header response;
1524                 u32 reserved5:4;
1525                 u32 format2:4;
1526                 u32 reserved6:24;
1527         } *sda_area;
1528
1529         sda_area = (void *)get_zeroed_page(GFP_KERNEL|GFP_DMA);
1530         if (!sda_area)
1531                 return -ENOMEM;
1532         sda_area->request.length = 0x0400;
1533         sda_area->request.code = 0x0031;
1534         sda_area->operation_code = operation_code;
1535
1536         ret = chsc(sda_area);
1537         if (ret > 0) {
1538                 ret = (ret == 3) ? -ENODEV : -EBUSY;
1539                 goto out;
1540         }
1541         switch (sda_area->response.code) {
1542         case 0x0001: /* everything ok */
1543                 ret = 0;
1544                 break;
1545         case 0x0003: /* invalid request block */
1546         case 0x0007:
1547                 ret = -EINVAL;
1548                 break;
1549         case 0x0004: /* command not provided */
1550         case 0x0101: /* facility not provided */
1551                 ret = -EOPNOTSUPP;
1552                 break;
1553         default: /* something went wrong */
1554                 ret = -EIO;
1555         }
1556  out:
1557         free_page((unsigned long)sda_area);
1558         return ret;
1559 }
1560
1561 subsys_initcall(chsc_alloc_sei_area);
1562
1563 struct css_general_char css_general_characteristics;
1564 struct css_chsc_char css_chsc_characteristics;
1565
1566 int __init
1567 chsc_determine_css_characteristics(void)
1568 {
1569         int result;
1570         struct {
1571                 struct chsc_header request;
1572                 u32 reserved1;
1573                 u32 reserved2;
1574                 u32 reserved3;
1575                 struct chsc_header response;
1576                 u32 reserved4;
1577                 u32 general_char[510];
1578                 u32 chsc_char[518];
1579         } *scsc_area;
1580
1581         scsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1582         if (!scsc_area) {
1583                 printk(KERN_WARNING"cio: Was not able to determine available" \
1584                        "CHSCs due to no memory.\n");
1585                 return -ENOMEM;
1586         }
1587
1588         scsc_area->request.length = 0x0010;
1589         scsc_area->request.code = 0x0010;
1590
1591         result = chsc(scsc_area);
1592         if (result) {
1593                 printk(KERN_WARNING"cio: Was not able to determine " \
1594                        "available CHSCs, cc=%i.\n", result);
1595                 result = -EIO;
1596                 goto exit;
1597         }
1598
1599         if (scsc_area->response.code != 1) {
1600                 printk(KERN_WARNING"cio: Was not able to determine " \
1601                        "available CHSCs.\n");
1602                 result = -EIO;
1603                 goto exit;
1604         }
1605         memcpy(&css_general_characteristics, scsc_area->general_char,
1606                sizeof(css_general_characteristics));
1607         memcpy(&css_chsc_characteristics, scsc_area->chsc_char,
1608                sizeof(css_chsc_characteristics));
1609 exit:
1610         free_page ((unsigned long) scsc_area);
1611         return result;
1612 }
1613
1614 EXPORT_SYMBOL_GPL(css_general_characteristics);
1615 EXPORT_SYMBOL_GPL(css_chsc_characteristics);