drivers/s390/cio/chsc.c

   1 /*
   2  *  drivers/s390/cio/chsc.c
   3  *   S/390 common I/O routines -- channel subsystem call
   4  *   $Revision: 1.128 $
   5  *
   6  *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
   7  *                            IBM Corporation
   8  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
   9  *               Cornelia Huck (cornelia.huck@de.ibm.com)
  10  *               Arnd Bergmann (arndb@de.ibm.com)
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/config.h>
  15 #include <linux/slab.h>
  16 #include <linux/init.h>
  17 #include <linux/device.h>
  18
  19 #include <asm/cio.h>
  20
  21 #include "css.h"
  22 #include "cio.h"
  23 #include "cio_debug.h"
  24 #include "ioasm.h"
  25 #include "chsc.h"
  26
  27 static void *sei_page;
  28
  29 static int new_channel_path(int chpid);
  30
  31 static inline void
  32 set_chp_logically_online(int chp, int onoff)
  33 {
  34         css[0]->chps[chp]->state = onoff;
  35 }
  36
  37 static int
  38 get_chp_status(int chp)
  39 {
  40         return (css[0]->chps[chp] ? css[0]->chps[chp]->state : -ENODEV);
  41 }
  42
  43 void
  44 chsc_validate_chpids(struct subchannel *sch)
  45 {
  46         int mask, chp;
  47
  48         for (chp = 0; chp <= 7; chp++) {
  49                 mask = 0x80 >> chp;
  50                 if (!get_chp_status(sch->schib.pmcw.chpid[chp]))
  51                         /* disable using this path */
  52                         sch->opm &= ~mask;
  53         }
  54 }
  55
  56 void
  57 chpid_is_actually_online(int chp)
  58 {
  59         int state;
  60
  61         state = get_chp_status(chp);
  62         if (state < 0) {
  63                 need_rescan = 1;
  64                 queue_work(slow_path_wq, &slow_path_work);
  65         } else
  66                 WARN_ON(!state);
  67 }
  68
  69 /* FIXME: this is _always_ called for every subchannel. shouldn't we
  70  *        process more than one at a time? */
  71 static int
  72 chsc_get_sch_desc_irq(struct subchannel *sch, void *page)
  73 {
  74         int ccode, j;
  75
  76         struct {
  77                 struct chsc_header request;
  78                 u16 reserved1a:10;
  79                 u16 ssid:2;
  80                 u16 reserved1b:4;
  81                 u16 f_sch;        /* first subchannel */
  82                 u16 reserved2;
  83                 u16 l_sch;        /* last subchannel */
  84                 u32 reserved3;
  85                 struct chsc_header response;
  86                 u32 reserved4;
  87                 u8 sch_valid : 1;
  88                 u8 dev_valid : 1;
  89                 u8 st        : 3; /* subchannel type */
  90                 u8 zeroes    : 3;
  91                 u8  unit_addr;    /* unit address */
  92                 u16 devno;        /* device number */
  93                 u8 path_mask;
  94                 u8 fla_valid_mask;
  95                 u16 sch;          /* subchannel */
  96                 u8 chpid[8];      /* chpids 0-7 */
  97                 u16 fla[8];       /* full link addresses 0-7 */
  98         } *ssd_area;
  99
 100         ssd_area = page;
 101
 102         ssd_area->request = (struct chsc_header) {
 103                 .length = 0x0010,
 104                 .code   = 0x0004,
 105         };
 106
 107         ssd_area->ssid = sch->schid.ssid;
 108         ssd_area->f_sch = sch->schid.sch_no;
 109         ssd_area->l_sch = sch->schid.sch_no;
 110
 111         ccode = chsc(ssd_area);
 112         if (ccode > 0) {
 113                 pr_debug("chsc returned with ccode = %d\n", ccode);
 114                 return (ccode == 3) ? -ENODEV : -EBUSY;
 115         }
 116
 117         switch (ssd_area->response.code) {
 118         case 0x0001: /* everything ok */
 119                 break;
 120         case 0x0002:
 121                 CIO_CRW_EVENT(2, "Invalid command!\n");
 122                 return -EINVAL;
 123         case 0x0003:
 124                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
 125                 return -EINVAL;
 126         case 0x0004:
 127                 CIO_CRW_EVENT(2, "Model does not provide ssd\n");
 128                 return -EOPNOTSUPP;
 129         default:
 130                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
 131                               ssd_area->response.code);
 132                 return -EIO;
 133         }
 134
 135         /*
 136          * ssd_area->st stores the type of the detected
 137          * subchannel, with the following definitions:
 138          *
 139          * 0: I/O subchannel:     All fields have meaning
 140          * 1: CHSC subchannel:    Only sch_val, st and sch
 141          *                        have meaning
 142          * 2: Message subchannel: All fields except unit_addr
 143          *                        have meaning
 144          * 3: ADM subchannel:     Only sch_val, st and sch
 145          *                        have meaning
 146          *
 147          * Other types are currently undefined.
 148          */
 149         if (ssd_area->st > 3) { /* uhm, that looks strange... */
 150                 CIO_CRW_EVENT(0, "Strange subchannel type %d"
 151                               " for sch 0.%x.%04x\n", ssd_area->st,
 152                               sch->schid.ssid, sch->schid.sch_no);
 153                 /*
 154                  * There may have been a new subchannel type defined in the
 155                  * time since this code was written; since we don't know which
 156                  * fields have meaning and what to do with it we just jump out
 157                  */
 158                 return 0;
 159         } else {
 160                 const char *type[4] = {"I/O", "chsc", "message", "ADM"};
 161                 CIO_CRW_EVENT(6, "ssd: sch 0.%x.%04x is %s subchannel\n",
 162                               sch->schid.ssid, sch->schid.sch_no,
 163                               type[ssd_area->st]);
 164
 165                 sch->ssd_info.valid = 1;
 166                 sch->ssd_info.type = ssd_area->st;
 167         }
 168
 169         if (ssd_area->st == 0 || ssd_area->st == 2) {
 170                 for (j = 0; j < 8; j++) {
 171                         if (!((0x80 >> j) & ssd_area->path_mask &
 172                               ssd_area->fla_valid_mask))
 173                                 continue;
 174                         sch->ssd_info.chpid[j] = ssd_area->chpid[j];
 175                         sch->ssd_info.fla[j]   = ssd_area->fla[j];
 176                 }
 177         }
 178         return 0;
 179 }
 180
 181 int
 182 css_get_ssd_info(struct subchannel *sch)
 183 {
 184         int ret;
 185         void *page;
 186
 187         page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
 188         if (!page)
 189                 return -ENOMEM;
 190         spin_lock_irq(&sch->lock);
 191         ret = chsc_get_sch_desc_irq(sch, page);
 192         if (ret) {
 193                 static int cio_chsc_err_msg;
 194
 195                 if (!cio_chsc_err_msg) {
 196                         printk(KERN_ERR
 197                                "chsc_get_sch_descriptions:"
 198                                " Error %d while doing chsc; "
 199                                "processing some machine checks may "
 200                                "not work\n", ret);
 201                         cio_chsc_err_msg = 1;
 202                 }
 203         }
 204         spin_unlock_irq(&sch->lock);
 205         free_page((unsigned long)page);
 206         if (!ret) {
 207                 int j, chpid;
 208                 /* Allocate channel path structures, if needed. */
 209                 for (j = 0; j < 8; j++) {
 210                         chpid = sch->ssd_info.chpid[j];
 211                         if (chpid && (get_chp_status(chpid) < 0))
 212                             new_channel_path(chpid);
 213                 }
 214         }
 215         return ret;
 216 }
 217
 218 static int
 219 s390_subchannel_remove_chpid(struct device *dev, void *data)
 220 {
 221         int j;
 222         int mask;
 223         struct subchannel *sch;
 224         struct channel_path *chpid;
 225         struct schib schib;
 226
 227         sch = to_subchannel(dev);
 228         chpid = data;
 229         for (j = 0; j < 8; j++)
 230                 if (sch->schib.pmcw.chpid[j] == chpid->id)
 231                         break;
 232         if (j >= 8)
 233                 return 0;
 234
 235         mask = 0x80 >> j;
 236         spin_lock(&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         if (sch->vpm == mask)
 246                 goto out_unreg;
 247
 248         if ((sch->schib.scsw.actl & (SCSW_ACTL_CLEAR_PEND |
 249                                      SCSW_ACTL_HALT_PEND |
 250                                      SCSW_ACTL_START_PEND |
 251                                      SCSW_ACTL_RESUME_PEND)) &&
 252             (sch->schib.pmcw.lpum == mask)) {
 253                 int cc = cio_cancel(sch);
 254
 255                 if (cc == -ENODEV)
 256                         goto out_unreg;
 257
 258                 if (cc == -EINVAL) {
 259                         cc = cio_clear(sch);
 260                         if (cc == -ENODEV)
 261                                 goto out_unreg;
 262                         /* Call handler. */
 263                         if (sch->driver && sch->driver->termination)
 264                                 sch->driver->termination(&sch->dev);
 265                         goto out_unlock;
 266                 }
 267         } else if ((sch->schib.scsw.actl & SCSW_ACTL_DEVACT) &&
 268                    (sch->schib.scsw.actl & SCSW_ACTL_SCHACT) &&
 269                    (sch->schib.pmcw.lpum == mask)) {
 270                 int cc;
 271
 272                 cc = cio_clear(sch);
 273                 if (cc == -ENODEV)
 274                         goto out_unreg;
 275                 /* Call handler. */
 276                 if (sch->driver && sch->driver->termination)
 277                         sch->driver->termination(&sch->dev);
 278                 goto out_unlock;
 279         }
 280
 281         /* trigger path verification. */
 282         if (sch->driver && sch->driver->verify)
 283                 sch->driver->verify(&sch->dev);
 284 out_unlock:
 285         spin_unlock(&sch->lock);
 286         return 0;
 287 out_unreg:
 288         spin_unlock(&sch->lock);
 289         sch->lpm = 0;
 290         if (css_enqueue_subchannel_slow(sch->schid)) {
 291                 css_clear_subchannel_slow_list();
 292                 need_rescan = 1;
 293         }
 294         return 0;
 295 }
 296
 297 static inline void
 298 s390_set_chpid_offline( __u8 chpid)
 299 {
 300         char dbf_txt[15];
 301         struct device *dev;
 302
 303         sprintf(dbf_txt, "chpr%x", chpid);
 304         CIO_TRACE_EVENT(2, dbf_txt);
 305
 306         if (get_chp_status(chpid) <= 0)
 307                 return;
 308         dev = get_device(&css[0]->chps[chpid]->dev);
 309         bus_for_each_dev(&css_bus_type, NULL, to_channelpath(dev),
 310                          s390_subchannel_remove_chpid);
 311
 312         if (need_rescan || css_slow_subchannels_exist())
 313                 queue_work(slow_path_wq, &slow_path_work);
 314         put_device(dev);
 315 }
 316
 317 struct res_acc_data {
 318         struct channel_path *chp;
 319         u32 fla_mask;
 320         u16 fla;
 321 };
 322
 323 static int
 324 s390_process_res_acc_sch(struct res_acc_data *res_data, struct subchannel *sch)
 325 {
 326         int found;
 327         int chp;
 328         int ccode;
 329
 330         found = 0;
 331         for (chp = 0; chp <= 7; chp++)
 332                 /*
 333                  * check if chpid is in information updated by ssd
 334                  */
 335                 if (sch->ssd_info.valid &&
 336                     sch->ssd_info.chpid[chp] == res_data->chp->id &&
 337                     (sch->ssd_info.fla[chp] & res_data->fla_mask)
 338                     == res_data->fla) {
 339                         found = 1;
 340                         break;
 341                 }
 342
 343         if (found == 0)
 344                 return 0;
 345
 346         /*
 347          * Do a stsch to update our subchannel structure with the
 348          * new path information and eventually check for logically
 349          * offline chpids.
 350          */
 351         ccode = stsch(sch->schid, &sch->schib);
 352         if (ccode > 0)
 353                 return 0;
 354
 355         return 0x80 >> chp;
 356 }
 357
 358 static inline int
 359 s390_process_res_acc_new_sch(struct subchannel_id schid)
 360 {
 361         struct schib schib;
 362         int ret;
 363         /*
 364          * We don't know the device yet, but since a path
 365          * may be available now to the device we'll have
 366          * to do recognition again.
 367          * Since we don't have any idea about which chpid
 368          * that beast may be on we'll have to do a stsch
 369          * on all devices, grr...
 370          */
 371         if (stsch_err(schid, &schib))
 372                 /* We're through */
 373                 return need_rescan ? -EAGAIN : -ENXIO;
 374
 375         /* Put it on the slow path. */
 376         ret = css_enqueue_subchannel_slow(schid);
 377         if (ret) {
 378                 css_clear_subchannel_slow_list();
 379                 need_rescan = 1;
 380                 return -EAGAIN;
 381         }
 382         return 0;
 383 }
 384
 385 static int
 386 __s390_process_res_acc(struct subchannel_id schid, void *data)
 387 {
 388         int chp_mask, old_lpm;
 389         struct res_acc_data *res_data;
 390         struct subchannel *sch;
 391
 392         res_data = (struct res_acc_data *)data;
 393         sch = get_subchannel_by_schid(schid);
 394         if (!sch)
 395                 /* Check if a subchannel is newly available. */
 396                 return s390_process_res_acc_new_sch(schid);
 397
 398         spin_lock_irq(&sch->lock);
 399
 400         chp_mask = s390_process_res_acc_sch(res_data, sch);
 401
 402         if (chp_mask == 0) {
 403                 spin_unlock_irq(&sch->lock);
 404                 return 0;
 405         }
 406         old_lpm = sch->lpm;
 407         sch->lpm = ((sch->schib.pmcw.pim &
 408                      sch->schib.pmcw.pam &
 409                      sch->schib.pmcw.pom)
 410                     | chp_mask) & sch->opm;
 411         if (!old_lpm && sch->lpm)
 412                 device_trigger_reprobe(sch);
 413         else if (sch->driver && sch->driver->verify)
 414                 sch->driver->verify(&sch->dev);
 415
 416         spin_unlock_irq(&sch->lock);
 417         put_device(&sch->dev);
 418         return (res_data->fla_mask == 0xffff) ? -ENODEV : 0;
 419 }
 420
 421
 422 static int
 423 s390_process_res_acc (struct res_acc_data *res_data)
 424 {
 425         int rc;
 426         char dbf_txt[15];
 427
 428         sprintf(dbf_txt, "accpr%x", res_data->chp->id);
 429         CIO_TRACE_EVENT( 2, dbf_txt);
 430         if (res_data->fla != 0) {
 431                 sprintf(dbf_txt, "fla%x", res_data->fla);
 432                 CIO_TRACE_EVENT( 2, dbf_txt);
 433         }
 434
 435         /*
 436          * I/O resources may have become accessible.
 437          * Scan through all subchannels that may be concerned and
 438          * do a validation on those.
 439          * The more information we have (info), the less scanning
 440          * will we have to do.
 441          */
 442         rc = for_each_subchannel(__s390_process_res_acc, res_data);
 443         if (css_slow_subchannels_exist())
 444                 rc = -EAGAIN;
 445         else if (rc != -EAGAIN)
 446                 rc = 0;
 447         return rc;
 448 }
 449
 450 static int
 451 __get_chpid_from_lir(void *data)
 452 {
 453         struct lir {
 454                 u8  iq;
 455                 u8  ic;
 456                 u16 sci;
 457                 /* incident-node descriptor */
 458                 u32 indesc[28];
 459                 /* attached-node descriptor */
 460                 u32 andesc[28];
 461                 /* incident-specific information */
 462                 u32 isinfo[28];
 463         } *lir;
 464
 465         lir = (struct lir*) data;
 466         if (!(lir->iq&0x80))
 467                 /* NULL link incident record */
 468                 return -EINVAL;
 469         if (!(lir->indesc[0]&0xc0000000))
 470                 /* node descriptor not valid */
 471                 return -EINVAL;
 472         if (!(lir->indesc[0]&0x10000000))
 473                 /* don't handle device-type nodes - FIXME */
 474                 return -EINVAL;
 475         /* Byte 3 contains the chpid. Could also be CTCA, but we don't care */
 476
 477         return (u16) (lir->indesc[0]&0x000000ff);
 478 }
 479
 480 int
 481 chsc_process_crw(void)
 482 {
 483         int chpid, ret;
 484         struct res_acc_data res_data;
 485         struct {
 486                 struct chsc_header request;
 487                 u32 reserved1;
 488                 u32 reserved2;
 489                 u32 reserved3;
 490                 struct chsc_header response;
 491                 u32 reserved4;
 492                 u8  flags;
 493                 u8  vf;         /* validity flags */
 494                 u8  rs;         /* reporting source */
 495                 u8  cc;         /* content code */
 496                 u16 fla;        /* full link address */
 497                 u16 rsid;       /* reporting source id */
 498                 u32 reserved5;
 499                 u32 reserved6;
 500                 u32 ccdf[96];   /* content-code dependent field */
 501                 /* ccdf has to be big enough for a link-incident record */
 502         } *sei_area;
 503
 504         if (!sei_page)
 505                 return 0;
 506         /*
 507          * build the chsc request block for store event information
 508          * and do the call
 509          * This function is only called by the machine check handler thread,
 510          * so we don't need locking for the sei_page.
 511          */
 512         sei_area = sei_page;
 513
 514         CIO_TRACE_EVENT( 2, "prcss");
 515         ret = 0;
 516         do {
 517                 int ccode, status;
 518                 struct device *dev;
 519                 memset(sei_area, 0, sizeof(*sei_area));
 520                 memset(&res_data, 0, sizeof(struct res_acc_data));
 521                 sei_area->request = (struct chsc_header) {
 522                         .length = 0x0010,
 523                         .code   = 0x000e,
 524                 };
 525
 526                 ccode = chsc(sei_area);
 527                 if (ccode > 0)
 528                         return 0;
 529
 530                 switch (sei_area->response.code) {
 531                         /* for debug purposes, check for problems */
 532                 case 0x0001:
 533                         CIO_CRW_EVENT(4, "chsc_process_crw: event information "
 534                                         "successfully stored\n");
 535                         break; /* everything ok */
 536                 case 0x0002:
 537                         CIO_CRW_EVENT(2,
 538                                       "chsc_process_crw: invalid command!\n");
 539                         return 0;
 540                 case 0x0003:
 541                         CIO_CRW_EVENT(2, "chsc_process_crw: error in chsc "
 542                                       "request block!\n");
 543                         return 0;
 544                 case 0x0005:
 545                         CIO_CRW_EVENT(2, "chsc_process_crw: no event "
 546                                       "information stored\n");
 547                         return 0;
 548                 default:
 549                         CIO_CRW_EVENT(2, "chsc_process_crw: chsc response %d\n",
 550                                       sei_area->response.code);
 551                         return 0;
 552                 }
 553
 554                 /* Check if we might have lost some information. */
 555                 if (sei_area->flags & 0x40)
 556                         CIO_CRW_EVENT(2, "chsc_process_crw: Event information "
 557                                        "has been lost due to overflow!\n");
 558
 559                 if (sei_area->rs != 4) {
 560                         CIO_CRW_EVENT(2, "chsc_process_crw: reporting source "
 561                                       "(%04X) isn't a chpid!\n",
 562                                       sei_area->rsid);
 563                         continue;
 564                 }
 565
 566                 /* which kind of information was stored? */
 567                 switch (sei_area->cc) {
 568                 case 1: /* link incident*/
 569                         CIO_CRW_EVENT(4, "chsc_process_crw: "
 570                                       "channel subsystem reports link incident,"
 571                                       " reporting source is chpid %x\n",
 572                                       sei_area->rsid);
 573                         chpid = __get_chpid_from_lir(sei_area->ccdf);
 574                         if (chpid < 0)
 575                                 CIO_CRW_EVENT(4, "%s: Invalid LIR, skipping\n",
 576                                               __FUNCTION__);
 577                         else
 578                                 s390_set_chpid_offline(chpid);
 579                         break;
 580
 581                 case 2: /* i/o resource accessibiliy */
 582                         CIO_CRW_EVENT(4, "chsc_process_crw: "
 583                                       "channel subsystem reports some I/O "
 584                                       "devices may have become accessible\n");
 585                         pr_debug("Data received after sei: \n");
 586                         pr_debug("Validity flags: %x\n", sei_area->vf);
 587
 588                         /* allocate a new channel path structure, if needed */
 589                         status = get_chp_status(sei_area->rsid);
 590                         if (status < 0)
 591                                 new_channel_path(sei_area->rsid);
 592                         else if (!status)
 593                                 break;
 594                         dev = get_device(&css[0]->chps[sei_area->rsid]->dev);
 595                         res_data.chp = to_channelpath(dev);
 596                         pr_debug("chpid: %x", sei_area->rsid);
 597                         if ((sei_area->vf & 0xc0) != 0) {
 598                                 res_data.fla = sei_area->fla;
 599                                 if ((sei_area->vf & 0xc0) == 0xc0) {
 600                                         pr_debug(" full link addr: %x",
 601                                                  sei_area->fla);
 602                                         res_data.fla_mask = 0xffff;
 603                                 } else {
 604                                         pr_debug(" link addr: %x",
 605                                                  sei_area->fla);
 606                                         res_data.fla_mask = 0xff00;
 607                                 }
 608                         }
 609                         ret = s390_process_res_acc(&res_data);
 610                         pr_debug("\n\n");
 611                         put_device(dev);
 612                         break;
 613
 614                 default: /* other stuff */
 615                         CIO_CRW_EVENT(4, "chsc_process_crw: event %d\n",
 616                                       sei_area->cc);
 617                         break;
 618                 }
 619         } while (sei_area->flags & 0x80);
 620         return ret;
 621 }
 622
 623 static inline int
 624 __chp_add_new_sch(struct subchannel_id schid)
 625 {
 626         struct schib schib;
 627         int ret;
 628
 629         if (stsch(schid, &schib))
 630                 /* We're through */
 631                 return need_rescan ? -EAGAIN : -ENXIO;
 632
 633         /* Put it on the slow path. */
 634         ret = css_enqueue_subchannel_slow(schid);
 635         if (ret) {
 636                 css_clear_subchannel_slow_list();
 637                 need_rescan = 1;
 638                 return -EAGAIN;
 639         }
 640         return 0;
 641 }
 642
 643
 644 static int
 645 __chp_add(struct subchannel_id schid, void *data)
 646 {
 647         int i;
 648         struct channel_path *chp;
 649         struct subchannel *sch;
 650
 651         chp = (struct channel_path *)data;
 652         sch = get_subchannel_by_schid(schid);
 653         if (!sch)
 654                 /* Check if the subchannel is now available. */
 655                 return __chp_add_new_sch(schid);
 656         spin_lock(&sch->lock);
 657         for (i=0; i<8; i++)
 658                 if (sch->schib.pmcw.chpid[i] == chp->id) {
 659                         if (stsch(sch->schid, &sch->schib) != 0) {
 660                                 /* Endgame. */
 661                                 spin_unlock(&sch->lock);
 662                                 return -ENXIO;
 663                         }
 664                         break;
 665                 }
 666         if (i==8) {
 667                 spin_unlock(&sch->lock);
 668                 return 0;
 669         }
 670         sch->lpm = ((sch->schib.pmcw.pim &
 671                      sch->schib.pmcw.pam &
 672                      sch->schib.pmcw.pom)
 673                     | 0x80 >> i) & sch->opm;
 674
 675         if (sch->driver && sch->driver->verify)
 676                 sch->driver->verify(&sch->dev);
 677
 678         spin_unlock(&sch->lock);
 679         put_device(&sch->dev);
 680         return 0;
 681 }
 682
 683 static int
 684 chp_add(int chpid)
 685 {
 686         int rc;
 687         char dbf_txt[15];
 688         struct device *dev;
 689
 690         if (!get_chp_status(chpid))
 691                 return 0; /* no need to do the rest */
 692
 693         sprintf(dbf_txt, "cadd%x", chpid);
 694         CIO_TRACE_EVENT(2, dbf_txt);
 695
 696         dev = get_device(&css[0]->chps[chpid]->dev);
 697         rc = for_each_subchannel(__chp_add, to_channelpath(dev));
 698         if (css_slow_subchannels_exist())
 699                 rc = -EAGAIN;
 700         if (rc != -EAGAIN)
 701                 rc = 0;
 702         put_device(dev);
 703         return rc;
 704 }
 705
 706 /*
 707  * Handling of crw machine checks with channel path source.
 708  */
 709 int
 710 chp_process_crw(int chpid, int on)
 711 {
 712         if (on == 0) {
 713                 /* Path has gone. We use the link incident routine.*/
 714                 s390_set_chpid_offline(chpid);
 715                 return 0; /* De-register is async anyway. */
 716         }
 717         /*
 718          * Path has come. Allocate a new channel path structure,
 719          * if needed.
 720          */
 721         if (get_chp_status(chpid) < 0)
 722                 new_channel_path(chpid);
 723         /* Avoid the extra overhead in process_rec_acc. */
 724         return chp_add(chpid);
 725 }
 726
 727 static inline int
 728 __check_for_io_and_kill(struct subchannel *sch, int index)
 729 {
 730         int cc;
 731
 732         if (!device_is_online(sch))
 733                 /* cio could be doing I/O. */
 734                 return 0;
 735         cc = stsch(sch->schid, &sch->schib);
 736         if (cc)
 737                 return 0;
 738         if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index)) {
 739                 device_set_waiting(sch);
 740                 return 1;
 741         }
 742         return 0;
 743 }
 744
 745 static inline void
 746 __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
 747 {
 748         int chp, old_lpm;
 749         unsigned long flags;
 750
 751         if (!sch->ssd_info.valid)
 752                 return;
 753
 754         spin_lock_irqsave(&sch->lock, flags);
 755         old_lpm = sch->lpm;
 756         for (chp = 0; chp < 8; chp++) {
 757                 if (sch->ssd_info.chpid[chp] != chpid)
 758                         continue;
 759
 760                 if (on) {
 761                         sch->opm |= (0x80 >> chp);
 762                         sch->lpm |= (0x80 >> chp);
 763                         if (!old_lpm)
 764                                 device_trigger_reprobe(sch);
 765                         else if (sch->driver && sch->driver->verify)
 766                                 sch->driver->verify(&sch->dev);
 767                 } else {
 768                         sch->opm &= ~(0x80 >> chp);
 769                         sch->lpm &= ~(0x80 >> chp);
 770                         /*
 771                          * Give running I/O a grace period in which it
 772                          * can successfully terminate, even using the
 773                          * just varied off path. Then kill it.
 774                          */
 775                         if (!__check_for_io_and_kill(sch, chp) && !sch->lpm) {
 776                                 if (css_enqueue_subchannel_slow(sch->schid)) {
 777                                         css_clear_subchannel_slow_list();
 778                                         need_rescan = 1;
 779                                 }
 780                         } else if (sch->driver && sch->driver->verify)
 781                                 sch->driver->verify(&sch->dev);
 782                 }
 783                 break;
 784         }
 785         spin_unlock_irqrestore(&sch->lock, flags);
 786 }
 787
 788 static int
 789 s390_subchannel_vary_chpid_off(struct device *dev, void *data)
 790 {
 791         struct subchannel *sch;
 792         __u8 *chpid;
 793
 794         sch = to_subchannel(dev);
 795         chpid = data;
 796
 797         __s390_subchannel_vary_chpid(sch, *chpid, 0);
 798         return 0;
 799 }
 800
 801 static int
 802 s390_subchannel_vary_chpid_on(struct device *dev, void *data)
 803 {
 804         struct subchannel *sch;
 805         __u8 *chpid;
 806
 807         sch = to_subchannel(dev);
 808         chpid = data;
 809
 810         __s390_subchannel_vary_chpid(sch, *chpid, 1);
 811         return 0;
 812 }
 813
 814 static int
 815 __s390_vary_chpid_on(struct subchannel_id schid, void *data)
 816 {
 817         struct schib schib;
 818         struct subchannel *sch;
 819
 820         sch = get_subchannel_by_schid(schid);
 821         if (sch) {
 822                 put_device(&sch->dev);
 823                 return 0;
 824         }
 825         if (stsch_err(schid, &schib))
 826                 /* We're through */
 827                 return -ENXIO;
 828         /* Put it on the slow path. */
 829         if (css_enqueue_subchannel_slow(schid)) {
 830                 css_clear_subchannel_slow_list();
 831                 need_rescan = 1;
 832                 return -EAGAIN;
 833         }
 834         return 0;
 835 }
 836
 837 /*
 838  * Function: s390_vary_chpid
 839  * Varies the specified chpid online or offline
 840  */
 841 static int
 842 s390_vary_chpid( __u8 chpid, int on)
 843 {
 844         char dbf_text[15];
 845         int status;
 846
 847         sprintf(dbf_text, on?"varyon%x":"varyoff%x", chpid);
 848         CIO_TRACE_EVENT( 2, dbf_text);
 849
 850         status = get_chp_status(chpid);
 851         if (status < 0) {
 852                 printk(KERN_ERR "Can't vary unknown chpid %02X\n", chpid);
 853                 return -EINVAL;
 854         }
 855
 856         if (!on && !status) {
 857                 printk(KERN_ERR "chpid %x is already offline\n", chpid);
 858                 return -EINVAL;
 859         }
 860
 861         set_chp_logically_online(chpid, on);
 862
 863         /*
 864          * Redo PathVerification on the devices the chpid connects to
 865          */
 866
 867         bus_for_each_dev(&css_bus_type, NULL, &chpid, on ?
 868                          s390_subchannel_vary_chpid_on :
 869                          s390_subchannel_vary_chpid_off);
 870         if (on)
 871                 /* Scan for new devices on varied on path. */
 872                 for_each_subchannel(__s390_vary_chpid_on, NULL);
 873         if (need_rescan || css_slow_subchannels_exist())
 874                 queue_work(slow_path_wq, &slow_path_work);
 875         return 0;
 876 }
 877
 878 /*
 879  * Files for the channel path entries.
 880  */
 881 static ssize_t
 882 chp_status_show(struct device *dev, struct device_attribute *attr, char *buf)
 883 {
 884         struct channel_path *chp = container_of(dev, struct channel_path, dev);
 885
 886         if (!chp)
 887                 return 0;
 888         return (get_chp_status(chp->id) ? sprintf(buf, "online\n") :
 889                 sprintf(buf, "offline\n"));
 890 }
 891
 892 static ssize_t
 893 chp_status_write(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 894 {
 895         struct channel_path *cp = container_of(dev, struct channel_path, dev);
 896         char cmd[10];
 897         int num_args;
 898         int error;
 899
 900         num_args = sscanf(buf, "%5s", cmd);
 901         if (!num_args)
 902                 return count;
 903
 904         if (!strnicmp(cmd, "on", 2))
 905                 error = s390_vary_chpid(cp->id, 1);
 906         else if (!strnicmp(cmd, "off", 3))
 907                 error = s390_vary_chpid(cp->id, 0);
 908         else
 909                 error = -EINVAL;
 910
 911         return error < 0 ? error : count;
 912
 913 }
 914
 915 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
 916
 917 static ssize_t
 918 chp_type_show(struct device *dev, struct device_attribute *attr, char *buf)
 919 {
 920         struct channel_path *chp = container_of(dev, struct channel_path, dev);
 921
 922         if (!chp)
 923                 return 0;
 924         return sprintf(buf, "%x\n", chp->desc.desc);
 925 }
 926
 927 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
 928
 929 static struct attribute * chp_attrs[] = {
 930         &dev_attr_status.attr,
 931         &dev_attr_type.attr,
 932         NULL,
 933 };
 934
 935 static struct attribute_group chp_attr_group = {
 936         .attrs = chp_attrs,
 937 };
 938
 939 static void
 940 chp_release(struct device *dev)
 941 {
 942         struct channel_path *cp;
 943
 944         cp = container_of(dev, struct channel_path, dev);
 945         kfree(cp);
 946 }
 947
 948 static int
 949 chsc_determine_channel_path_description(int chpid,
 950                                         struct channel_path_desc *desc)
 951 {
 952         int ccode, ret;
 953
 954         struct {
 955                 struct chsc_header request;
 956                 u32 : 24;
 957                 u32 first_chpid : 8;
 958                 u32 : 24;
 959                 u32 last_chpid : 8;
 960                 u32 zeroes1;
 961                 struct chsc_header response;
 962                 u32 zeroes2;
 963                 struct channel_path_desc desc;
 964         } *scpd_area;
 965
 966         scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
 967         if (!scpd_area)
 968                 return -ENOMEM;
 969
 970         scpd_area->request = (struct chsc_header) {
 971                 .length = 0x0010,
 972                 .code   = 0x0002,
 973         };
 974
 975         scpd_area->first_chpid = chpid;
 976         scpd_area->last_chpid = chpid;
 977
 978         ccode = chsc(scpd_area);
 979         if (ccode > 0) {
 980                 ret = (ccode == 3) ? -ENODEV : -EBUSY;
 981                 goto out;
 982         }
 983
 984         switch (scpd_area->response.code) {
 985         case 0x0001: /* Success. */
 986                 memcpy(desc, &scpd_area->desc,
 987                        sizeof(struct channel_path_desc));
 988                 ret = 0;
 989                 break;
 990         case 0x0003: /* Invalid block. */
 991         case 0x0007: /* Invalid format. */
 992         case 0x0008: /* Other invalid block. */
 993                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
 994                 ret = -EINVAL;
 995                 break;
 996         case 0x0004: /* Command not provided in model. */
 997                 CIO_CRW_EVENT(2, "Model does not provide scpd\n");
 998                 ret = -EOPNOTSUPP;
 999                 break;
1000         default:
1001                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
1002                               scpd_area->response.code);
1003                 ret = -EIO;
1004         }
1005 out:
1006         free_page((unsigned long)scpd_area);
1007         return ret;
1008 }
1009
1010 /*
1011  * Entries for chpids on the system bus.
1012  * This replaces /proc/chpids.
1013  */
1014 static int
1015 new_channel_path(int chpid)
1016 {
1017         struct channel_path *chp;
1018         int ret;
1019
1020         chp = kmalloc(sizeof(struct channel_path), GFP_KERNEL);
1021         if (!chp)
1022                 return -ENOMEM;
1023         memset(chp, 0, sizeof(struct channel_path));
1024
1025         /* fill in status, etc. */
1026         chp->id = chpid;
1027         chp->state = 1;
1028         chp->dev = (struct device) {
1029                 .parent  = &css[0]->device,
1030                 .release = chp_release,
1031         };
1032         snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp0.%x", chpid);
1033
1034         /* Obtain channel path description and fill it in. */
1035         ret = chsc_determine_channel_path_description(chpid, &chp->desc);
1036         if (ret)
1037                 goto out_free;
1038
1039         /* make it known to the system */
1040         ret = device_register(&chp->dev);
1041         if (ret) {
1042                 printk(KERN_WARNING "%s: could not register %02x\n",
1043                        __func__, chpid);
1044                 goto out_free;
1045         }
1046         ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
1047         if (ret) {
1048                 device_unregister(&chp->dev);
1049                 goto out_free;
1050         } else
1051                 css[0]->chps[chpid] = chp;
1052         return ret;
1053 out_free:
1054         kfree(chp);
1055         return ret;
1056 }
1057
1058 void *
1059 chsc_get_chp_desc(struct subchannel *sch, int chp_no)
1060 {
1061         struct channel_path *chp;
1062         struct channel_path_desc *desc;
1063
1064         chp = css[0]->chps[sch->schib.pmcw.chpid[chp_no]];
1065         if (!chp)
1066                 return NULL;
1067         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
1068         if (!desc)
1069                 return NULL;
1070         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
1071         return desc;
1072 }
1073
1074
1075 static int __init
1076 chsc_alloc_sei_area(void)
1077 {
1078         sei_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1079         if (!sei_page)
1080                 printk(KERN_WARNING"Can't allocate page for processing of " \
1081                        "chsc machine checks!\n");
1082         return (sei_page ? 0 : -ENOMEM);
1083 }
1084
1085 int __init
1086 chsc_enable_facility(int operation_code)
1087 {
1088         int ret;
1089         struct {
1090                 struct chsc_header request;
1091                 u8 reserved1:4;
1092                 u8 format:4;
1093                 u8 reserved2;
1094                 u16 operation_code;
1095                 u32 reserved3;
1096                 u32 reserved4;
1097                 u32 operation_data_area[252];
1098                 struct chsc_header response;
1099                 u32 reserved5:4;
1100                 u32 format2:4;
1101                 u32 reserved6:24;
1102         } *sda_area;
1103
1104         sda_area = (void *)get_zeroed_page(GFP_KERNEL|GFP_DMA);
1105         if (!sda_area)
1106                 return -ENOMEM;
1107         sda_area->request = (struct chsc_header) {
1108                 .length = 0x0400,
1109                 .code = 0x0031,
1110         };
1111         sda_area->operation_code = operation_code;
1112
1113         ret = chsc(sda_area);
1114         if (ret > 0) {
1115                 ret = (ret == 3) ? -ENODEV : -EBUSY;
1116                 goto out;
1117         }
1118         switch (sda_area->response.code) {
1119         case 0x0003: /* invalid request block */
1120         case 0x0007:
1121                 ret = -EINVAL;
1122                 break;
1123         case 0x0004: /* command not provided */
1124         case 0x0101: /* facility not provided */
1125                 ret = -EOPNOTSUPP;
1126                 break;
1127         }
1128  out:
1129         free_page((unsigned long)sda_area);
1130         return ret;
1131 }
1132
1133 subsys_initcall(chsc_alloc_sei_area);
1134
1135 struct css_general_char css_general_characteristics;
1136 struct css_chsc_char css_chsc_characteristics;
1137
1138 int __init
1139 chsc_determine_css_characteristics(void)
1140 {
1141         int result;
1142         struct {
1143                 struct chsc_header request;
1144                 u32 reserved1;
1145                 u32 reserved2;
1146                 u32 reserved3;
1147                 struct chsc_header response;
1148                 u32 reserved4;
1149                 u32 general_char[510];
1150                 u32 chsc_char[518];
1151         } *scsc_area;
1152
1153         scsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1154         if (!scsc_area) {
1155                 printk(KERN_WARNING"cio: Was not able to determine available" \
1156                        "CHSCs due to no memory.\n");
1157                 return -ENOMEM;
1158         }
1159
1160         scsc_area->request = (struct chsc_header) {
1161                 .length = 0x0010,
1162                 .code   = 0x0010,
1163         };
1164
1165         result = chsc(scsc_area);
1166         if (result) {
1167                 printk(KERN_WARNING"cio: Was not able to determine " \
1168                        "available CHSCs, cc=%i.\n", result);
1169                 result = -EIO;
1170                 goto exit;
1171         }
1172
1173         if (scsc_area->response.code != 1) {
1174                 printk(KERN_WARNING"cio: Was not able to determine " \
1175                        "available CHSCs.\n");
1176                 result = -EIO;
1177                 goto exit;
1178         }
1179         memcpy(&css_general_characteristics, scsc_area->general_char,
1180                sizeof(css_general_characteristics));
1181         memcpy(&css_chsc_characteristics, scsc_area->chsc_char,
1182                sizeof(css_chsc_characteristics));
1183 exit:
1184         free_page ((unsigned long) scsc_area);
1185         return result;
1186 }
1187
1188 EXPORT_SYMBOL_GPL(css_general_characteristics);
1189 EXPORT_SYMBOL_GPL(css_chsc_characteristics);