drivers/s390/cio/chsc.c

   1 /*
   2  *  drivers/s390/cio/chsc.c
   3  *   S/390 common I/O routines -- channel subsystem call
   4  *   $Revision: 1.120 $
   5  *
   6  *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
   7  *                            IBM Corporation
   8  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
   9  *               Cornelia Huck (cohuck@de.ibm.com)
  10  *               Arnd Bergmann (arndb@de.ibm.com)
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/config.h>
  15 #include <linux/slab.h>
  16 #include <linux/init.h>
  17 #include <linux/device.h>
  18
  19 #include <asm/cio.h>
  20
  21 #include "css.h"
  22 #include "cio.h"
  23 #include "cio_debug.h"
  24 #include "ioasm.h"
  25 #include "chsc.h"
  26
  27 static struct channel_path *chps[NR_CHPIDS];
  28
  29 static void *sei_page;
  30
  31 static int new_channel_path(int chpid);
  32
  33 static inline void
  34 set_chp_logically_online(int chp, int onoff)
  35 {
  36         chps[chp]->state = onoff;
  37 }
  38
  39 static int
  40 get_chp_status(int chp)
  41 {
  42         return (chps[chp] ? chps[chp]->state : -ENODEV);
  43 }
  44
  45 void
  46 chsc_validate_chpids(struct subchannel *sch)
  47 {
  48         int mask, chp;
  49
  50         for (chp = 0; chp <= 7; chp++) {
  51                 mask = 0x80 >> chp;
  52                 if (!get_chp_status(sch->schib.pmcw.chpid[chp]))
  53                         /* disable using this path */
  54                         sch->opm &= ~mask;
  55         }
  56 }
  57
  58 void
  59 chpid_is_actually_online(int chp)
  60 {
  61         int state;
  62
  63         state = get_chp_status(chp);
  64         if (state < 0) {
  65                 need_rescan = 1;
  66                 queue_work(slow_path_wq, &slow_path_work);
  67         } else
  68                 WARN_ON(!state);
  69 }
  70
  71 /* FIXME: this is _always_ called for every subchannel. shouldn't we
  72  *        process more than one at a time? */
  73 static int
  74 chsc_get_sch_desc_irq(struct subchannel *sch, void *page)
  75 {
  76         int ccode, j;
  77
  78         struct {
  79                 struct chsc_header request;
  80                 u16 reserved1;
  81                 u16 f_sch;        /* first subchannel */
  82                 u16 reserved2;
  83                 u16 l_sch;        /* last subchannel */
  84                 u32 reserved3;
  85                 struct chsc_header response;
  86                 u32 reserved4;
  87                 u8 sch_valid : 1;
  88                 u8 dev_valid : 1;
  89                 u8 st        : 3; /* subchannel type */
  90                 u8 zeroes    : 3;
  91                 u8  unit_addr;    /* unit address */
  92                 u16 devno;        /* device number */
  93                 u8 path_mask;
  94                 u8 fla_valid_mask;
  95                 u16 sch;          /* subchannel */
  96                 u8 chpid[8];      /* chpids 0-7 */
  97                 u16 fla[8];       /* full link addresses 0-7 */
  98         } *ssd_area;
  99
 100         ssd_area = page;
 101
 102         ssd_area->request = (struct chsc_header) {
 103                 .length = 0x0010,
 104                 .code   = 0x0004,
 105         };
 106
 107         ssd_area->f_sch = sch->schid.sch_no;
 108         ssd_area->l_sch = sch->schid.sch_no;
 109
 110         ccode = chsc(ssd_area);
 111         if (ccode > 0) {
 112                 pr_debug("chsc returned with ccode = %d\n", ccode);
 113                 return (ccode == 3) ? -ENODEV : -EBUSY;
 114         }
 115
 116         switch (ssd_area->response.code) {
 117         case 0x0001: /* everything ok */
 118                 break;
 119         case 0x0002:
 120                 CIO_CRW_EVENT(2, "Invalid command!\n");
 121                 return -EINVAL;
 122         case 0x0003:
 123                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
 124                 return -EINVAL;
 125         case 0x0004:
 126                 CIO_CRW_EVENT(2, "Model does not provide ssd\n");
 127                 return -EOPNOTSUPP;
 128         default:
 129                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
 130                               ssd_area->response.code);
 131                 return -EIO;
 132         }
 133
 134         /*
 135          * ssd_area->st stores the type of the detected
 136          * subchannel, with the following definitions:
 137          *
 138          * 0: I/O subchannel:     All fields have meaning
 139          * 1: CHSC subchannel:    Only sch_val, st and sch
 140          *                        have meaning
 141          * 2: Message subchannel: All fields except unit_addr
 142          *                        have meaning
 143          * 3: ADM subchannel:     Only sch_val, st and sch
 144          *                        have meaning
 145          *
 146          * Other types are currently undefined.
 147          */
 148         if (ssd_area->st > 3) { /* uhm, that looks strange... */
 149                 CIO_CRW_EVENT(0, "Strange subchannel type %d"
 150                               " for sch %04x\n", ssd_area->st,
 151                               sch->schid.sch_no);
 152                 /*
 153                  * There may have been a new subchannel type defined in the
 154                  * time since this code was written; since we don't know which
 155                  * fields have meaning and what to do with it we just jump out
 156                  */
 157                 return 0;
 158         } else {
 159                 const char *type[4] = {"I/O", "chsc", "message", "ADM"};
 160                 CIO_CRW_EVENT(6, "ssd: sch %04x is %s subchannel\n",
 161                               sch->schid.sch_no, type[ssd_area->st]);
 162
 163                 sch->ssd_info.valid = 1;
 164                 sch->ssd_info.type = ssd_area->st;
 165         }
 166
 167         if (ssd_area->st == 0 || ssd_area->st == 2) {
 168                 for (j = 0; j < 8; j++) {
 169                         if (!((0x80 >> j) & ssd_area->path_mask &
 170                               ssd_area->fla_valid_mask))
 171                                 continue;
 172                         sch->ssd_info.chpid[j] = ssd_area->chpid[j];
 173                         sch->ssd_info.fla[j]   = ssd_area->fla[j];
 174                 }
 175         }
 176         return 0;
 177 }
 178
 179 int
 180 css_get_ssd_info(struct subchannel *sch)
 181 {
 182         int ret;
 183         void *page;
 184
 185         page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
 186         if (!page)
 187                 return -ENOMEM;
 188         spin_lock_irq(&sch->lock);
 189         ret = chsc_get_sch_desc_irq(sch, page);
 190         if (ret) {
 191                 static int cio_chsc_err_msg;
 192
 193                 if (!cio_chsc_err_msg) {
 194                         printk(KERN_ERR
 195                                "chsc_get_sch_descriptions:"
 196                                " Error %d while doing chsc; "
 197                                "processing some machine checks may "
 198                                "not work\n", ret);
 199                         cio_chsc_err_msg = 1;
 200                 }
 201         }
 202         spin_unlock_irq(&sch->lock);
 203         free_page((unsigned long)page);
 204         if (!ret) {
 205                 int j, chpid;
 206                 /* Allocate channel path structures, if needed. */
 207                 for (j = 0; j < 8; j++) {
 208                         chpid = sch->ssd_info.chpid[j];
 209                         if (chpid && (get_chp_status(chpid) < 0))
 210                             new_channel_path(chpid);
 211                 }
 212         }
 213         return ret;
 214 }
 215
 216 static int
 217 s390_subchannel_remove_chpid(struct device *dev, void *data)
 218 {
 219         int j;
 220         int mask;
 221         struct subchannel *sch;
 222         __u8 *chpid;
 223         struct schib schib;
 224
 225         sch = to_subchannel(dev);
 226         chpid = data;
 227         for (j = 0; j < 8; j++)
 228                 if (sch->schib.pmcw.chpid[j] == *chpid)
 229                         break;
 230         if (j >= 8)
 231                 return 0;
 232
 233         mask = 0x80 >> j;
 234         spin_lock(&sch->lock);
 235
 236         stsch(sch->schid, &schib);
 237         if (!schib.pmcw.dnv)
 238                 goto out_unreg;
 239         memcpy(&sch->schib, &schib, sizeof(struct schib));
 240         /* Check for single path devices. */
 241         if (sch->schib.pmcw.pim == 0x80)
 242                 goto out_unreg;
 243         if (sch->vpm == mask)
 244                 goto out_unreg;
 245
 246         if ((sch->schib.scsw.actl & (SCSW_ACTL_CLEAR_PEND |
 247                                      SCSW_ACTL_HALT_PEND |
 248                                      SCSW_ACTL_START_PEND |
 249                                      SCSW_ACTL_RESUME_PEND)) &&
 250             (sch->schib.pmcw.lpum == mask)) {
 251                 int cc = cio_cancel(sch);
 252
 253                 if (cc == -ENODEV)
 254                         goto out_unreg;
 255
 256                 if (cc == -EINVAL) {
 257                         cc = cio_clear(sch);
 258                         if (cc == -ENODEV)
 259                                 goto out_unreg;
 260                         /* Call handler. */
 261                         if (sch->driver && sch->driver->termination)
 262                                 sch->driver->termination(&sch->dev);
 263                         goto out_unlock;
 264                 }
 265         } else if ((sch->schib.scsw.actl & SCSW_ACTL_DEVACT) &&
 266                    (sch->schib.scsw.actl & SCSW_ACTL_SCHACT) &&
 267                    (sch->schib.pmcw.lpum == mask)) {
 268                 int cc;
 269
 270                 cc = cio_clear(sch);
 271                 if (cc == -ENODEV)
 272                         goto out_unreg;
 273                 /* Call handler. */
 274                 if (sch->driver && sch->driver->termination)
 275                         sch->driver->termination(&sch->dev);
 276                 goto out_unlock;
 277         }
 278
 279         /* trigger path verification. */
 280         if (sch->driver && sch->driver->verify)
 281                 sch->driver->verify(&sch->dev);
 282 out_unlock:
 283         spin_unlock(&sch->lock);
 284         return 0;
 285 out_unreg:
 286         spin_unlock(&sch->lock);
 287         sch->lpm = 0;
 288         if (css_enqueue_subchannel_slow(sch->schid)) {
 289                 css_clear_subchannel_slow_list();
 290                 need_rescan = 1;
 291         }
 292         return 0;
 293 }
 294
 295 static inline void
 296 s390_set_chpid_offline( __u8 chpid)
 297 {
 298         char dbf_txt[15];
 299
 300         sprintf(dbf_txt, "chpr%x", chpid);
 301         CIO_TRACE_EVENT(2, dbf_txt);
 302
 303         if (get_chp_status(chpid) <= 0)
 304                 return;
 305
 306         bus_for_each_dev(&css_bus_type, NULL, &chpid,
 307                          s390_subchannel_remove_chpid);
 308
 309         if (need_rescan || css_slow_subchannels_exist())
 310                 queue_work(slow_path_wq, &slow_path_work);
 311 }
 312
 313 struct res_acc_data {
 314         struct channel_path *chp;
 315         u32 fla_mask;
 316         u16 fla;
 317 };
 318
 319 static int
 320 s390_process_res_acc_sch(struct res_acc_data *res_data, struct subchannel *sch)
 321 {
 322         int found;
 323         int chp;
 324         int ccode;
 325
 326         found = 0;
 327         for (chp = 0; chp <= 7; chp++)
 328                 /*
 329                  * check if chpid is in information updated by ssd
 330                  */
 331                 if (sch->ssd_info.valid &&
 332                     sch->ssd_info.chpid[chp] == res_data->chp->id &&
 333                     (sch->ssd_info.fla[chp] & res_data->fla_mask)
 334                     == res_data->fla) {
 335                         found = 1;
 336                         break;
 337                 }
 338
 339         if (found == 0)
 340                 return 0;
 341
 342         /*
 343          * Do a stsch to update our subchannel structure with the
 344          * new path information and eventually check for logically
 345          * offline chpids.
 346          */
 347         ccode = stsch(sch->schid, &sch->schib);
 348         if (ccode > 0)
 349                 return 0;
 350
 351         return 0x80 >> chp;
 352 }
 353
 354 static inline int
 355 s390_process_res_acc_new_sch(struct subchannel_id schid)
 356 {
 357         struct schib schib;
 358         int ret;
 359         /*
 360          * We don't know the device yet, but since a path
 361          * may be available now to the device we'll have
 362          * to do recognition again.
 363          * Since we don't have any idea about which chpid
 364          * that beast may be on we'll have to do a stsch
 365          * on all devices, grr...
 366          */
 367         if (stsch(schid, &schib))
 368                 /* We're through */
 369                 return need_rescan ? -EAGAIN : -ENXIO;
 370
 371         /* Put it on the slow path. */
 372         ret = css_enqueue_subchannel_slow(schid);
 373         if (ret) {
 374                 css_clear_subchannel_slow_list();
 375                 need_rescan = 1;
 376                 return -EAGAIN;
 377         }
 378         return 0;
 379 }
 380
 381 static int
 382 __s390_process_res_acc(struct subchannel_id schid, void *data)
 383 {
 384         int chp_mask, old_lpm;
 385         struct res_acc_data *res_data;
 386         struct subchannel *sch;
 387
 388         res_data = (struct res_acc_data *)data;
 389         sch = get_subchannel_by_schid(schid);
 390         if (!sch)
 391                 /* Check if a subchannel is newly available. */
 392                 return s390_process_res_acc_new_sch(schid);
 393
 394         spin_lock_irq(&sch->lock);
 395
 396         chp_mask = s390_process_res_acc_sch(res_data, sch);
 397
 398         if (chp_mask == 0) {
 399                 spin_unlock_irq(&sch->lock);
 400                 return 0;
 401         }
 402         old_lpm = sch->lpm;
 403         sch->lpm = ((sch->schib.pmcw.pim &
 404                      sch->schib.pmcw.pam &
 405                      sch->schib.pmcw.pom)
 406                     | chp_mask) & sch->opm;
 407         if (!old_lpm && sch->lpm)
 408                 device_trigger_reprobe(sch);
 409         else if (sch->driver && sch->driver->verify)
 410                 sch->driver->verify(&sch->dev);
 411
 412         spin_unlock_irq(&sch->lock);
 413         put_device(&sch->dev);
 414         return (res_data->fla_mask == 0xffff) ? -ENODEV : 0;
 415 }
 416
 417
 418 static int
 419 s390_process_res_acc (struct res_acc_data *res_data)
 420 {
 421         int rc;
 422         char dbf_txt[15];
 423
 424         sprintf(dbf_txt, "accpr%x", res_data->chp->id);
 425         CIO_TRACE_EVENT( 2, dbf_txt);
 426         if (res_data->fla != 0) {
 427                 sprintf(dbf_txt, "fla%x", res_data->fla);
 428                 CIO_TRACE_EVENT( 2, dbf_txt);
 429         }
 430
 431         /*
 432          * I/O resources may have become accessible.
 433          * Scan through all subchannels that may be concerned and
 434          * do a validation on those.
 435          * The more information we have (info), the less scanning
 436          * will we have to do.
 437          */
 438         rc = for_each_subchannel(__s390_process_res_acc, res_data);
 439         if (css_slow_subchannels_exist())
 440                 rc = -EAGAIN;
 441         else if (rc != -EAGAIN)
 442                 rc = 0;
 443         return rc;
 444 }
 445
 446 static int
 447 __get_chpid_from_lir(void *data)
 448 {
 449         struct lir {
 450                 u8  iq;
 451                 u8  ic;
 452                 u16 sci;
 453                 /* incident-node descriptor */
 454                 u32 indesc[28];
 455                 /* attached-node descriptor */
 456                 u32 andesc[28];
 457                 /* incident-specific information */
 458                 u32 isinfo[28];
 459         } *lir;
 460
 461         lir = (struct lir*) data;
 462         if (!(lir->iq&0x80))
 463                 /* NULL link incident record */
 464                 return -EINVAL;
 465         if (!(lir->indesc[0]&0xc0000000))
 466                 /* node descriptor not valid */
 467                 return -EINVAL;
 468         if (!(lir->indesc[0]&0x10000000))
 469                 /* don't handle device-type nodes - FIXME */
 470                 return -EINVAL;
 471         /* Byte 3 contains the chpid. Could also be CTCA, but we don't care */
 472
 473         return (u16) (lir->indesc[0]&0x000000ff);
 474 }
 475
 476 int
 477 chsc_process_crw(void)
 478 {
 479         int chpid, ret;
 480         struct res_acc_data res_data;
 481         struct {
 482                 struct chsc_header request;
 483                 u32 reserved1;
 484                 u32 reserved2;
 485                 u32 reserved3;
 486                 struct chsc_header response;
 487                 u32 reserved4;
 488                 u8  flags;
 489                 u8  vf;         /* validity flags */
 490                 u8  rs;         /* reporting source */
 491                 u8  cc;         /* content code */
 492                 u16 fla;        /* full link address */
 493                 u16 rsid;       /* reporting source id */
 494                 u32 reserved5;
 495                 u32 reserved6;
 496                 u32 ccdf[96];   /* content-code dependent field */
 497                 /* ccdf has to be big enough for a link-incident record */
 498         } *sei_area;
 499
 500         if (!sei_page)
 501                 return 0;
 502         /*
 503          * build the chsc request block for store event information
 504          * and do the call
 505          * This function is only called by the machine check handler thread,
 506          * so we don't need locking for the sei_page.
 507          */
 508         sei_area = sei_page;
 509
 510         CIO_TRACE_EVENT( 2, "prcss");
 511         ret = 0;
 512         do {
 513                 int ccode, status;
 514                 memset(sei_area, 0, sizeof(*sei_area));
 515                 memset(&res_data, 0, sizeof(struct res_acc_data));
 516                 sei_area->request = (struct chsc_header) {
 517                         .length = 0x0010,
 518                         .code   = 0x000e,
 519                 };
 520
 521                 ccode = chsc(sei_area);
 522                 if (ccode > 0)
 523                         return 0;
 524
 525                 switch (sei_area->response.code) {
 526                         /* for debug purposes, check for problems */
 527                 case 0x0001:
 528                         CIO_CRW_EVENT(4, "chsc_process_crw: event information "
 529                                         "successfully stored\n");
 530                         break; /* everything ok */
 531                 case 0x0002:
 532                         CIO_CRW_EVENT(2,
 533                                       "chsc_process_crw: invalid command!\n");
 534                         return 0;
 535                 case 0x0003:
 536                         CIO_CRW_EVENT(2, "chsc_process_crw: error in chsc "
 537                                       "request block!\n");
 538                         return 0;
 539                 case 0x0005:
 540                         CIO_CRW_EVENT(2, "chsc_process_crw: no event "
 541                                       "information stored\n");
 542                         return 0;
 543                 default:
 544                         CIO_CRW_EVENT(2, "chsc_process_crw: chsc response %d\n",
 545                                       sei_area->response.code);
 546                         return 0;
 547                 }
 548
 549                 /* Check if we might have lost some information. */
 550                 if (sei_area->flags & 0x40)
 551                         CIO_CRW_EVENT(2, "chsc_process_crw: Event information "
 552                                        "has been lost due to overflow!\n");
 553
 554                 if (sei_area->rs != 4) {
 555                         CIO_CRW_EVENT(2, "chsc_process_crw: reporting source "
 556                                       "(%04X) isn't a chpid!\n",
 557                                       sei_area->rsid);
 558                         continue;
 559                 }
 560
 561                 /* which kind of information was stored? */
 562                 switch (sei_area->cc) {
 563                 case 1: /* link incident*/
 564                         CIO_CRW_EVENT(4, "chsc_process_crw: "
 565                                       "channel subsystem reports link incident,"
 566                                       " reporting source is chpid %x\n",
 567                                       sei_area->rsid);
 568                         chpid = __get_chpid_from_lir(sei_area->ccdf);
 569                         if (chpid < 0)
 570                                 CIO_CRW_EVENT(4, "%s: Invalid LIR, skipping\n",
 571                                               __FUNCTION__);
 572                         else
 573                                 s390_set_chpid_offline(chpid);
 574                         break;
 575
 576                 case 2: /* i/o resource accessibiliy */
 577                         CIO_CRW_EVENT(4, "chsc_process_crw: "
 578                                       "channel subsystem reports some I/O "
 579                                       "devices may have become accessible\n");
 580                         pr_debug("Data received after sei: \n");
 581                         pr_debug("Validity flags: %x\n", sei_area->vf);
 582
 583                         /* allocate a new channel path structure, if needed */
 584                         status = get_chp_status(sei_area->rsid);
 585                         if (status < 0)
 586                                 new_channel_path(sei_area->rsid);
 587                         else if (!status)
 588                                 break;
 589                         res_data.chp = chps[sei_area->rsid];
 590                         pr_debug("chpid: %x", sei_area->rsid);
 591                         if ((sei_area->vf & 0xc0) != 0) {
 592                                 res_data.fla = sei_area->fla;
 593                                 if ((sei_area->vf & 0xc0) == 0xc0) {
 594                                         pr_debug(" full link addr: %x",
 595                                                  sei_area->fla);
 596                                         res_data.fla_mask = 0xffff;
 597                                 } else {
 598                                         pr_debug(" link addr: %x",
 599                                                  sei_area->fla);
 600                                         res_data.fla_mask = 0xff00;
 601                                 }
 602                         }
 603                         ret = s390_process_res_acc(&res_data);
 604                         pr_debug("\n\n");
 605                         break;
 606
 607                 default: /* other stuff */
 608                         CIO_CRW_EVENT(4, "chsc_process_crw: event %d\n",
 609                                       sei_area->cc);
 610                         break;
 611                 }
 612         } while (sei_area->flags & 0x80);
 613         return ret;
 614 }
 615
 616 static inline int
 617 __chp_add_new_sch(struct subchannel_id schid)
 618 {
 619         struct schib schib;
 620         int ret;
 621
 622         if (stsch(schid, &schib))
 623                 /* We're through */
 624                 return need_rescan ? -EAGAIN : -ENXIO;
 625
 626         /* Put it on the slow path. */
 627         ret = css_enqueue_subchannel_slow(schid);
 628         if (ret) {
 629                 css_clear_subchannel_slow_list();
 630                 need_rescan = 1;
 631                 return -EAGAIN;
 632         }
 633         return 0;
 634 }
 635
 636
 637 static int
 638 __chp_add(struct subchannel_id schid, void *data)
 639 {
 640         int i;
 641         struct channel_path *chp;
 642         struct subchannel *sch;
 643
 644         chp = (struct channel_path *)data;
 645         sch = get_subchannel_by_schid(schid);
 646         if (!sch)
 647                 /* Check if the subchannel is now available. */
 648                 return __chp_add_new_sch(schid);
 649         spin_lock(&sch->lock);
 650         for (i=0; i<8; i++)
 651                 if (sch->schib.pmcw.chpid[i] == chp->id) {
 652                         if (stsch(sch->schid, &sch->schib) != 0) {
 653                                 /* Endgame. */
 654                                 spin_unlock(&sch->lock);
 655                                 return -ENXIO;
 656                         }
 657                         break;
 658                 }
 659         if (i==8) {
 660                 spin_unlock(&sch->lock);
 661                 return 0;
 662         }
 663         sch->lpm = ((sch->schib.pmcw.pim &
 664                      sch->schib.pmcw.pam &
 665                      sch->schib.pmcw.pom)
 666                     | 0x80 >> i) & sch->opm;
 667
 668         if (sch->driver && sch->driver->verify)
 669                 sch->driver->verify(&sch->dev);
 670
 671         spin_unlock(&sch->lock);
 672         put_device(&sch->dev);
 673         return 0;
 674 }
 675
 676 static int
 677 chp_add(int chpid)
 678 {
 679         int rc;
 680         char dbf_txt[15];
 681
 682         if (!get_chp_status(chpid))
 683                 return 0; /* no need to do the rest */
 684
 685         sprintf(dbf_txt, "cadd%x", chpid);
 686         CIO_TRACE_EVENT(2, dbf_txt);
 687
 688         rc = for_each_subchannel(__chp_add, chps[chpid]);
 689         if (css_slow_subchannels_exist())
 690                 rc = -EAGAIN;
 691         if (rc != -EAGAIN)
 692                 rc = 0;
 693         return rc;
 694 }
 695
 696 /*
 697  * Handling of crw machine checks with channel path source.
 698  */
 699 int
 700 chp_process_crw(int chpid, int on)
 701 {
 702         if (on == 0) {
 703                 /* Path has gone. We use the link incident routine.*/
 704                 s390_set_chpid_offline(chpid);
 705                 return 0; /* De-register is async anyway. */
 706         }
 707         /*
 708          * Path has come. Allocate a new channel path structure,
 709          * if needed.
 710          */
 711         if (get_chp_status(chpid) < 0)
 712                 new_channel_path(chpid);
 713         /* Avoid the extra overhead in process_rec_acc. */
 714         return chp_add(chpid);
 715 }
 716
 717 static inline int
 718 __check_for_io_and_kill(struct subchannel *sch, int index)
 719 {
 720         int cc;
 721
 722         if (!device_is_online(sch))
 723                 /* cio could be doing I/O. */
 724                 return 0;
 725         cc = stsch(sch->schid, &sch->schib);
 726         if (cc)
 727                 return 0;
 728         if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index)) {
 729                 device_set_waiting(sch);
 730                 return 1;
 731         }
 732         return 0;
 733 }
 734
 735 static inline void
 736 __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
 737 {
 738         int chp, old_lpm;
 739         unsigned long flags;
 740
 741         if (!sch->ssd_info.valid)
 742                 return;
 743
 744         spin_lock_irqsave(&sch->lock, flags);
 745         old_lpm = sch->lpm;
 746         for (chp = 0; chp < 8; chp++) {
 747                 if (sch->ssd_info.chpid[chp] != chpid)
 748                         continue;
 749
 750                 if (on) {
 751                         sch->opm |= (0x80 >> chp);
 752                         sch->lpm |= (0x80 >> chp);
 753                         if (!old_lpm)
 754                                 device_trigger_reprobe(sch);
 755                         else if (sch->driver && sch->driver->verify)
 756                                 sch->driver->verify(&sch->dev);
 757                 } else {
 758                         sch->opm &= ~(0x80 >> chp);
 759                         sch->lpm &= ~(0x80 >> chp);
 760                         /*
 761                          * Give running I/O a grace period in which it
 762                          * can successfully terminate, even using the
 763                          * just varied off path. Then kill it.
 764                          */
 765                         if (!__check_for_io_and_kill(sch, chp) && !sch->lpm) {
 766                                 if (css_enqueue_subchannel_slow(sch->schid)) {
 767                                         css_clear_subchannel_slow_list();
 768                                         need_rescan = 1;
 769                                 }
 770                         } else if (sch->driver && sch->driver->verify)
 771                                 sch->driver->verify(&sch->dev);
 772                 }
 773                 break;
 774         }
 775         spin_unlock_irqrestore(&sch->lock, flags);
 776 }
 777
 778 static int
 779 s390_subchannel_vary_chpid_off(struct device *dev, void *data)
 780 {
 781         struct subchannel *sch;
 782         __u8 *chpid;
 783
 784         sch = to_subchannel(dev);
 785         chpid = data;
 786
 787         __s390_subchannel_vary_chpid(sch, *chpid, 0);
 788         return 0;
 789 }
 790
 791 static int
 792 s390_subchannel_vary_chpid_on(struct device *dev, void *data)
 793 {
 794         struct subchannel *sch;
 795         __u8 *chpid;
 796
 797         sch = to_subchannel(dev);
 798         chpid = data;
 799
 800         __s390_subchannel_vary_chpid(sch, *chpid, 1);
 801         return 0;
 802 }
 803
 804 static int
 805 __s390_vary_chpid_on(struct subchannel_id schid, void *data)
 806 {
 807         struct schib schib;
 808         struct subchannel *sch;
 809
 810         sch = get_subchannel_by_schid(schid);
 811         if (sch) {
 812                 put_device(&sch->dev);
 813                 return 0;
 814         }
 815         if (stsch(schid, &schib))
 816                 /* We're through */
 817                 return -ENXIO;
 818         /* Put it on the slow path. */
 819         if (css_enqueue_subchannel_slow(schid)) {
 820                 css_clear_subchannel_slow_list();
 821                 need_rescan = 1;
 822                 return -EAGAIN;
 823         }
 824         return 0;
 825 }
 826
 827 /*
 828  * Function: s390_vary_chpid
 829  * Varies the specified chpid online or offline
 830  */
 831 static int
 832 s390_vary_chpid( __u8 chpid, int on)
 833 {
 834         char dbf_text[15];
 835         int status;
 836
 837         sprintf(dbf_text, on?"varyon%x":"varyoff%x", chpid);
 838         CIO_TRACE_EVENT( 2, dbf_text);
 839
 840         status = get_chp_status(chpid);
 841         if (status < 0) {
 842                 printk(KERN_ERR "Can't vary unknown chpid %02X\n", chpid);
 843                 return -EINVAL;
 844         }
 845
 846         if (!on && !status) {
 847                 printk(KERN_ERR "chpid %x is already offline\n", chpid);
 848                 return -EINVAL;
 849         }
 850
 851         set_chp_logically_online(chpid, on);
 852
 853         /*
 854          * Redo PathVerification on the devices the chpid connects to
 855          */
 856
 857         bus_for_each_dev(&css_bus_type, NULL, &chpid, on ?
 858                          s390_subchannel_vary_chpid_on :
 859                          s390_subchannel_vary_chpid_off);
 860         if (on)
 861                 /* Scan for new devices on varied on path. */
 862                 for_each_subchannel(__s390_vary_chpid_on, NULL);
 863         if (need_rescan || css_slow_subchannels_exist())
 864                 queue_work(slow_path_wq, &slow_path_work);
 865         return 0;
 866 }
 867
 868 /*
 869  * Files for the channel path entries.
 870  */
 871 static ssize_t
 872 chp_status_show(struct device *dev, struct device_attribute *attr, char *buf)
 873 {
 874         struct channel_path *chp = container_of(dev, struct channel_path, dev);
 875
 876         if (!chp)
 877                 return 0;
 878         return (get_chp_status(chp->id) ? sprintf(buf, "online\n") :
 879                 sprintf(buf, "offline\n"));
 880 }
 881
 882 static ssize_t
 883 chp_status_write(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 884 {
 885         struct channel_path *cp = container_of(dev, struct channel_path, dev);
 886         char cmd[10];
 887         int num_args;
 888         int error;
 889
 890         num_args = sscanf(buf, "%5s", cmd);
 891         if (!num_args)
 892                 return count;
 893
 894         if (!strnicmp(cmd, "on", 2))
 895                 error = s390_vary_chpid(cp->id, 1);
 896         else if (!strnicmp(cmd, "off", 3))
 897                 error = s390_vary_chpid(cp->id, 0);
 898         else
 899                 error = -EINVAL;
 900
 901         return error < 0 ? error : count;
 902
 903 }
 904
 905 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
 906
 907 static ssize_t
 908 chp_type_show(struct device *dev, struct device_attribute *attr, char *buf)
 909 {
 910         struct channel_path *chp = container_of(dev, struct channel_path, dev);
 911
 912         if (!chp)
 913                 return 0;
 914         return sprintf(buf, "%x\n", chp->desc.desc);
 915 }
 916
 917 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
 918
 919 static struct attribute * chp_attrs[] = {
 920         &dev_attr_status.attr,
 921         &dev_attr_type.attr,
 922         NULL,
 923 };
 924
 925 static struct attribute_group chp_attr_group = {
 926         .attrs = chp_attrs,
 927 };
 928
 929 static void
 930 chp_release(struct device *dev)
 931 {
 932         struct channel_path *cp;
 933
 934         cp = container_of(dev, struct channel_path, dev);
 935         kfree(cp);
 936 }
 937
 938 static int
 939 chsc_determine_channel_path_description(int chpid,
 940                                         struct channel_path_desc *desc)
 941 {
 942         int ccode, ret;
 943
 944         struct {
 945                 struct chsc_header request;
 946                 u32 : 24;
 947                 u32 first_chpid : 8;
 948                 u32 : 24;
 949                 u32 last_chpid : 8;
 950                 u32 zeroes1;
 951                 struct chsc_header response;
 952                 u32 zeroes2;
 953                 struct channel_path_desc desc;
 954         } *scpd_area;
 955
 956         scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
 957         if (!scpd_area)
 958                 return -ENOMEM;
 959
 960         scpd_area->request = (struct chsc_header) {
 961                 .length = 0x0010,
 962                 .code   = 0x0002,
 963         };
 964
 965         scpd_area->first_chpid = chpid;
 966         scpd_area->last_chpid = chpid;
 967
 968         ccode = chsc(scpd_area);
 969         if (ccode > 0) {
 970                 ret = (ccode == 3) ? -ENODEV : -EBUSY;
 971                 goto out;
 972         }
 973
 974         switch (scpd_area->response.code) {
 975         case 0x0001: /* Success. */
 976                 memcpy(desc, &scpd_area->desc,
 977                        sizeof(struct channel_path_desc));
 978                 ret = 0;
 979                 break;
 980         case 0x0003: /* Invalid block. */
 981         case 0x0007: /* Invalid format. */
 982         case 0x0008: /* Other invalid block. */
 983                 CIO_CRW_EVENT(2, "Error in chsc request block!\n");
 984                 ret = -EINVAL;
 985                 break;
 986         case 0x0004: /* Command not provided in model. */
 987                 CIO_CRW_EVENT(2, "Model does not provide scpd\n");
 988                 ret = -EOPNOTSUPP;
 989                 break;
 990         default:
 991                 CIO_CRW_EVENT(2, "Unknown CHSC response %d\n",
 992                               scpd_area->response.code);
 993                 ret = -EIO;
 994         }
 995 out:
 996         free_page((unsigned long)scpd_area);
 997         return ret;
 998 }
 999
1000 /*
1001  * Entries for chpids on the system bus.
1002  * This replaces /proc/chpids.
1003  */
1004 static int
1005 new_channel_path(int chpid)
1006 {
1007         struct channel_path *chp;
1008         int ret;
1009
1010         chp = kmalloc(sizeof(struct channel_path), GFP_KERNEL);
1011         if (!chp)
1012                 return -ENOMEM;
1013         memset(chp, 0, sizeof(struct channel_path));
1014
1015         /* fill in status, etc. */
1016         chp->id = chpid;
1017         chp->state = 1;
1018         chp->dev = (struct device) {
1019                 .parent  = &css_bus_device,
1020                 .release = chp_release,
1021         };
1022         snprintf(chp->dev.bus_id, BUS_ID_SIZE, "chp0.%x", chpid);
1023
1024         /* Obtain channel path description and fill it in. */
1025         ret = chsc_determine_channel_path_description(chpid, &chp->desc);
1026         if (ret)
1027                 goto out_free;
1028
1029         /* make it known to the system */
1030         ret = device_register(&chp->dev);
1031         if (ret) {
1032                 printk(KERN_WARNING "%s: could not register %02x\n",
1033                        __func__, chpid);
1034                 goto out_free;
1035         }
1036         ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
1037         if (ret) {
1038                 device_unregister(&chp->dev);
1039                 goto out_free;
1040         } else
1041                 chps[chpid] = chp;
1042         return ret;
1043 out_free:
1044         kfree(chp);
1045         return ret;
1046 }
1047
1048 void *
1049 chsc_get_chp_desc(struct subchannel *sch, int chp_no)
1050 {
1051         struct channel_path *chp;
1052         struct channel_path_desc *desc;
1053
1054         chp = chps[sch->schib.pmcw.chpid[chp_no]];
1055         if (!chp)
1056                 return NULL;
1057         desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
1058         if (!desc)
1059                 return NULL;
1060         memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
1061         return desc;
1062 }
1063
1064
1065 static int __init
1066 chsc_alloc_sei_area(void)
1067 {
1068         sei_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1069         if (!sei_page)
1070                 printk(KERN_WARNING"Can't allocate page for processing of " \
1071                        "chsc machine checks!\n");
1072         return (sei_page ? 0 : -ENOMEM);
1073 }
1074
1075 subsys_initcall(chsc_alloc_sei_area);
1076
1077 struct css_general_char css_general_characteristics;
1078 struct css_chsc_char css_chsc_characteristics;
1079
1080 int __init
1081 chsc_determine_css_characteristics(void)
1082 {
1083         int result;
1084         struct {
1085                 struct chsc_header request;
1086                 u32 reserved1;
1087                 u32 reserved2;
1088                 u32 reserved3;
1089                 struct chsc_header response;
1090                 u32 reserved4;
1091                 u32 general_char[510];
1092                 u32 chsc_char[518];
1093         } *scsc_area;
1094
1095         scsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
1096         if (!scsc_area) {
1097                 printk(KERN_WARNING"cio: Was not able to determine available" \
1098                        "CHSCs due to no memory.\n");
1099                 return -ENOMEM;
1100         }
1101
1102         scsc_area->request = (struct chsc_header) {
1103                 .length = 0x0010,
1104                 .code   = 0x0010,
1105         };
1106
1107         result = chsc(scsc_area);
1108         if (result) {
1109                 printk(KERN_WARNING"cio: Was not able to determine " \
1110                        "available CHSCs, cc=%i.\n", result);
1111                 result = -EIO;
1112                 goto exit;
1113         }
1114
1115         if (scsc_area->response.code != 1) {
1116                 printk(KERN_WARNING"cio: Was not able to determine " \
1117                        "available CHSCs.\n");
1118                 result = -EIO;
1119                 goto exit;
1120         }
1121         memcpy(&css_general_characteristics, scsc_area->general_char,
1122                sizeof(css_general_characteristics));
1123         memcpy(&css_chsc_characteristics, scsc_area->chsc_char,
1124                sizeof(css_chsc_characteristics));
1125 exit:
1126         free_page ((unsigned long) scsc_area);
1127         return result;
1128 }
1129
1130 EXPORT_SYMBOL_GPL(css_general_characteristics);
1131 EXPORT_SYMBOL_GPL(css_chsc_characteristics);