drivers/s390/cio/device_pgid.c

   1 /*
   2  * drivers/s390/cio/device_pgid.c
   3  *
   4  *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
   5  *                       IBM Corporation
   6  *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
   7  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   8  *
   9  * Path Group ID functions.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14
  15 #include <asm/ccwdev.h>
  16 #include <asm/cio.h>
  17 #include <asm/delay.h>
  18 #include <asm/lowcore.h>
  19
  20 #include "cio.h"
  21 #include "cio_debug.h"
  22 #include "css.h"
  23 #include "device.h"
  24 #include "ioasm.h"
  25
  26 /*
  27  * Helper function called from interrupt context to decide whether an
  28  * operation should be tried again.
  29  */
  30 static int __ccw_device_should_retry(struct scsw *scsw)
  31 {
  32         /* CC is only valid if start function bit is set. */
  33         if ((scsw->fctl & SCSW_FCTL_START_FUNC) && scsw->cc == 1)
  34                 return 1;
  35         /* No more activity. For sense and set PGID we stubbornly try again. */
  36         if (!scsw->actl)
  37                 return 1;
  38         return 0;
  39 }
  40
  41 /*
  42  * Start Sense Path Group ID helper function. Used in ccw_device_recog
  43  * and ccw_device_sense_pgid.
  44  */
  45 static int
  46 __ccw_device_sense_pgid_start(struct ccw_device *cdev)
  47 {
  48         struct subchannel *sch;
  49         struct ccw1 *ccw;
  50         int ret;
  51         int i;
  52
  53         sch = to_subchannel(cdev->dev.parent);
  54         /* Return if we already checked on all paths. */
  55         if (cdev->private->imask == 0)
  56                 return (sch->lpm == 0) ? -ENODEV : -EACCES;
  57         i = 8 - ffs(cdev->private->imask);
  58
  59         /* Setup sense path group id channel program. */
  60         ccw = cdev->private->iccws;
  61         ccw->cmd_code = CCW_CMD_SENSE_PGID;
  62         ccw->count = sizeof (struct pgid);
  63         ccw->flags = CCW_FLAG_SLI;
  64
  65         /* Reset device status. */
  66         memset(&cdev->private->irb, 0, sizeof(struct irb));
  67         /* Try on every path. */
  68         ret = -ENODEV;
  69         while (cdev->private->imask != 0) {
  70                 /* Try every path multiple times. */
  71                 ccw->cda = (__u32) __pa (&cdev->private->pgid[i]);
  72                 if (cdev->private->iretry > 0) {
  73                         cdev->private->iretry--;
  74                         ret = cio_start (sch, cdev->private->iccws,
  75                                          cdev->private->imask);
  76                         /* ret is 0, -EBUSY, -EACCES or -ENODEV */
  77                         if (ret != -EACCES)
  78                                 return ret;
  79                         CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel "
  80                                       "0.%x.%04x, lpm %02X, became 'not "
  81                                       "operational'\n",
  82                                       cdev->private->devno, sch->schid.ssid,
  83                                       sch->schid.sch_no, cdev->private->imask);
  84
  85                 }
  86                 cdev->private->imask >>= 1;
  87                 cdev->private->iretry = 5;
  88                 i++;
  89         }
  90
  91         return ret;
  92 }
  93
  94 void
  95 ccw_device_sense_pgid_start(struct ccw_device *cdev)
  96 {
  97         int ret;
  98
  99         cdev->private->state = DEV_STATE_SENSE_PGID;
 100         cdev->private->imask = 0x80;
 101         cdev->private->iretry = 5;
 102         memset (&cdev->private->pgid, 0, sizeof (cdev->private->pgid));
 103         ret = __ccw_device_sense_pgid_start(cdev);
 104         if (ret && ret != -EBUSY)
 105                 ccw_device_sense_pgid_done(cdev, ret);
 106 }
 107
 108 /*
 109  * Called from interrupt context to check if a valid answer
 110  * to Sense Path Group ID was received.
 111  */
 112 static int
 113 __ccw_device_check_sense_pgid(struct ccw_device *cdev)
 114 {
 115         struct subchannel *sch;
 116         struct irb *irb;
 117         int i;
 118
 119         sch = to_subchannel(cdev->dev.parent);
 120         irb = &cdev->private->irb;
 121         if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
 122                 return -ETIME;
 123         if (irb->esw.esw0.erw.cons &&
 124             (irb->ecw[0]&(SNS0_CMD_REJECT|SNS0_INTERVENTION_REQ))) {
 125                 /*
 126                  * If the device doesn't support the Sense Path Group ID
 127                  *  command further retries wouldn't help ...
 128                  */
 129                 return -EOPNOTSUPP;
 130         }
 131         if (irb->esw.esw0.erw.cons) {
 132                 CIO_MSG_EVENT(2, "SNID - device 0.%x.%04x, unit check, "
 133                               "lpum %02X, cnt %02d, sns : "
 134                               "%02X%02X%02X%02X %02X%02X%02X%02X ...\n",
 135                               cdev->private->ssid, cdev->private->devno,
 136                               irb->esw.esw0.sublog.lpum,
 137                               irb->esw.esw0.erw.scnt,
 138                               irb->ecw[0], irb->ecw[1],
 139                               irb->ecw[2], irb->ecw[3],
 140                               irb->ecw[4], irb->ecw[5],
 141                               irb->ecw[6], irb->ecw[7]);
 142                 return -EAGAIN;
 143         }
 144         if (irb->scsw.cc == 3) {
 145                 CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x,"
 146                               " lpm %02X, became 'not operational'\n",
 147                               cdev->private->devno, sch->schid.ssid,
 148                               sch->schid.sch_no, sch->orb.lpm);
 149                 return -EACCES;
 150         }
 151         i = 8 - ffs(cdev->private->imask);
 152         if (cdev->private->pgid[i].inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
 153                 CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x "
 154                               "is reserved by someone else\n",
 155                               cdev->private->devno, sch->schid.ssid,
 156                               sch->schid.sch_no);
 157                 return -EUSERS;
 158         }
 159         return 0;
 160 }
 161
 162 /*
 163  * Got interrupt for Sense Path Group ID.
 164  */
 165 void
 166 ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
 167 {
 168         struct subchannel *sch;
 169         struct irb *irb;
 170         int ret;
 171
 172         irb = (struct irb *) __LC_IRB;
 173
 174         if (irb->scsw.stctl ==
 175             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 176                 if (__ccw_device_should_retry(&irb->scsw)) {
 177                         ret = __ccw_device_sense_pgid_start(cdev);
 178                         if (ret && ret != -EBUSY)
 179                                 ccw_device_sense_pgid_done(cdev, ret);
 180                 }
 181                 return;
 182         }
 183         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 184                 return;
 185         sch = to_subchannel(cdev->dev.parent);
 186         ret = __ccw_device_check_sense_pgid(cdev);
 187         memset(&cdev->private->irb, 0, sizeof(struct irb));
 188         switch (ret) {
 189         /* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
 190         case -EOPNOTSUPP:       /* Sense Path Group ID not supported */
 191                 ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
 192                 break;
 193         case -ETIME:            /* Sense path group id stopped by timeout. */
 194                 ccw_device_sense_pgid_done(cdev, -ETIME);
 195                 break;
 196         case -EACCES:           /* channel is not operational. */
 197                 sch->lpm &= ~cdev->private->imask;
 198                 /* Fall through. */
 199         case 0:                 /* Sense Path Group ID successful. */
 200                 cdev->private->imask >>= 1;
 201                 cdev->private->iretry = 5;
 202                 /* Fall through. */
 203         case -EAGAIN:           /* Try again. */
 204                 ret = __ccw_device_sense_pgid_start(cdev);
 205                 if (ret != 0 && ret != -EBUSY)
 206                         ccw_device_sense_pgid_done(cdev, ret);
 207                 break;
 208         case -EUSERS:           /* device is reserved for someone else. */
 209                 ccw_device_sense_pgid_done(cdev, -EUSERS);
 210                 break;
 211         }
 212 }
 213
 214 /*
 215  * Path Group ID helper function.
 216  */
 217 static int
 218 __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
 219 {
 220         struct subchannel *sch;
 221         struct ccw1 *ccw;
 222         int ret;
 223
 224         sch = to_subchannel(cdev->dev.parent);
 225
 226         /* Setup sense path group id channel program. */
 227         cdev->private->pgid[0].inf.fc = func;
 228         ccw = cdev->private->iccws;
 229         if (!cdev->private->flags.pgid_single) {
 230                 cdev->private->pgid[0].inf.fc |= SPID_FUNC_MULTI_PATH;
 231                 ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
 232                 ccw->cda = 0;
 233                 ccw->count = 0;
 234                 ccw->flags = CCW_FLAG_SLI | CCW_FLAG_CC;
 235                 ccw++;
 236         } else
 237                 cdev->private->pgid[0].inf.fc |= SPID_FUNC_SINGLE_PATH;
 238
 239         ccw->cmd_code = CCW_CMD_SET_PGID;
 240         ccw->cda = (__u32) __pa (&cdev->private->pgid[0]);
 241         ccw->count = sizeof (struct pgid);
 242         ccw->flags = CCW_FLAG_SLI;
 243
 244         /* Reset device status. */
 245         memset(&cdev->private->irb, 0, sizeof(struct irb));
 246
 247         /* Try multiple times. */
 248         ret = -EACCES;
 249         if (cdev->private->iretry > 0) {
 250                 cdev->private->iretry--;
 251                 ret = cio_start (sch, cdev->private->iccws,
 252                                  cdev->private->imask);
 253                 /* We expect an interrupt in case of success or busy
 254                  * indication. */
 255                 if ((ret == 0) || (ret == -EBUSY))
 256                         return ret;
 257         }
 258         /* PGID command failed on this path. */
 259         CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
 260                       "0.%x.%04x, lpm %02X, became 'not operational'\n",
 261                       cdev->private->devno, sch->schid.ssid,
 262                       sch->schid.sch_no, cdev->private->imask);
 263         return ret;
 264 }
 265
 266 /*
 267  * Helper function to send a nop ccw down a path.
 268  */
 269 static int __ccw_device_do_nop(struct ccw_device *cdev)
 270 {
 271         struct subchannel *sch;
 272         struct ccw1 *ccw;
 273         int ret;
 274
 275         sch = to_subchannel(cdev->dev.parent);
 276
 277         /* Setup nop channel program. */
 278         ccw = cdev->private->iccws;
 279         ccw->cmd_code = CCW_CMD_NOOP;
 280         ccw->cda = 0;
 281         ccw->count = 0;
 282         ccw->flags = CCW_FLAG_SLI;
 283
 284         /* Reset device status. */
 285         memset(&cdev->private->irb, 0, sizeof(struct irb));
 286
 287         /* Try multiple times. */
 288         ret = -EACCES;
 289         if (cdev->private->iretry > 0) {
 290                 cdev->private->iretry--;
 291                 ret = cio_start (sch, cdev->private->iccws,
 292                                  cdev->private->imask);
 293                 /* We expect an interrupt in case of success or busy
 294                  * indication. */
 295                 if ((ret == 0) || (ret == -EBUSY))
 296                         return ret;
 297         }
 298         /* nop command failed on this path. */
 299         CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel "
 300                       "0.%x.%04x, lpm %02X, became 'not operational'\n",
 301                       cdev->private->devno, sch->schid.ssid,
 302                       sch->schid.sch_no, cdev->private->imask);
 303         return ret;
 304 }
 305
 306
 307 /*
 308  * Called from interrupt context to check if a valid answer
 309  * to Set Path Group ID was received.
 310  */
 311 static int
 312 __ccw_device_check_pgid(struct ccw_device *cdev)
 313 {
 314         struct subchannel *sch;
 315         struct irb *irb;
 316
 317         sch = to_subchannel(cdev->dev.parent);
 318         irb = &cdev->private->irb;
 319         if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
 320                 return -ETIME;
 321         if (irb->esw.esw0.erw.cons) {
 322                 if (irb->ecw[0] & SNS0_CMD_REJECT)
 323                         return -EOPNOTSUPP;
 324                 /* Hmm, whatever happened, try again. */
 325                 CIO_MSG_EVENT(2, "SPID - device 0.%x.%04x, unit check, "
 326                               "cnt %02d, "
 327                               "sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
 328                               cdev->private->ssid,
 329                               cdev->private->devno, irb->esw.esw0.erw.scnt,
 330                               irb->ecw[0], irb->ecw[1],
 331                               irb->ecw[2], irb->ecw[3],
 332                               irb->ecw[4], irb->ecw[5],
 333                               irb->ecw[6], irb->ecw[7]);
 334                 return -EAGAIN;
 335         }
 336         if (irb->scsw.cc == 3) {
 337                 CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel 0.%x.%04x,"
 338                               " lpm %02X, became 'not operational'\n",
 339                               cdev->private->devno, sch->schid.ssid,
 340                               sch->schid.sch_no, cdev->private->imask);
 341                 return -EACCES;
 342         }
 343         return 0;
 344 }
 345
 346 /*
 347  * Called from interrupt context to check the path status after a nop has
 348  * been send.
 349  */
 350 static int __ccw_device_check_nop(struct ccw_device *cdev)
 351 {
 352         struct subchannel *sch;
 353         struct irb *irb;
 354
 355         sch = to_subchannel(cdev->dev.parent);
 356         irb = &cdev->private->irb;
 357         if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
 358                 return -ETIME;
 359         if (irb->scsw.cc == 3) {
 360                 CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel 0.%x.%04x,"
 361                               " lpm %02X, became 'not operational'\n",
 362                               cdev->private->devno, sch->schid.ssid,
 363                               sch->schid.sch_no, cdev->private->imask);
 364                 return -EACCES;
 365         }
 366         return 0;
 367 }
 368
 369 static void
 370 __ccw_device_verify_start(struct ccw_device *cdev)
 371 {
 372         struct subchannel *sch;
 373         __u8 func;
 374         int ret;
 375
 376         sch = to_subchannel(cdev->dev.parent);
 377         /* Repeat for all paths. */
 378         for (; cdev->private->imask; cdev->private->imask >>= 1,
 379                                      cdev->private->iretry = 5) {
 380                 if ((cdev->private->imask & sch->schib.pmcw.pam) == 0)
 381                         /* Path not available, try next. */
 382                         continue;
 383                 if (cdev->private->options.pgroup) {
 384                         if (sch->opm & cdev->private->imask)
 385                                 func = SPID_FUNC_ESTABLISH;
 386                         else
 387                                 func = SPID_FUNC_RESIGN;
 388                         ret = __ccw_device_do_pgid(cdev, func);
 389                 } else
 390                         ret = __ccw_device_do_nop(cdev);
 391                 /* We expect an interrupt in case of success or busy
 392                  * indication. */
 393                 if (ret == 0 || ret == -EBUSY)
 394                         return;
 395                 /* Permanent path failure, try next. */
 396         }
 397         /* Done with all paths. */
 398         ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV);
 399 }
 400
 401 /*
 402  * Got interrupt for Set Path Group ID.
 403  */
 404 void
 405 ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
 406 {
 407         struct subchannel *sch;
 408         struct irb *irb;
 409         int ret;
 410
 411         irb = (struct irb *) __LC_IRB;
 412
 413         if (irb->scsw.stctl ==
 414             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 415                 if (__ccw_device_should_retry(&irb->scsw))
 416                         __ccw_device_verify_start(cdev);
 417                 return;
 418         }
 419         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 420                 return;
 421         sch = to_subchannel(cdev->dev.parent);
 422         if (cdev->private->options.pgroup)
 423                 ret = __ccw_device_check_pgid(cdev);
 424         else
 425                 ret = __ccw_device_check_nop(cdev);
 426         memset(&cdev->private->irb, 0, sizeof(struct irb));
 427
 428         switch (ret) {
 429         /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
 430         case 0:
 431                 /* Path verification ccw finished successfully, update lpm. */
 432                 sch->vpm |= sch->opm & cdev->private->imask;
 433                 /* Go on with next path. */
 434                 cdev->private->imask >>= 1;
 435                 cdev->private->iretry = 5;
 436                 __ccw_device_verify_start(cdev);
 437                 break;
 438         case -EOPNOTSUPP:
 439                 /*
 440                  * One of those strange devices which claim to be able
 441                  * to do multipathing but not for Set Path Group ID.
 442                  */
 443                 if (cdev->private->flags.pgid_single)
 444                         cdev->private->options.pgroup = 0;
 445                 else
 446                         cdev->private->flags.pgid_single = 1;
 447                 /* Retry */
 448                 sch->vpm = 0;
 449                 cdev->private->imask = 0x80;
 450                 cdev->private->iretry = 5;
 451                 /* fall through. */
 452         case -EAGAIN:           /* Try again. */
 453                 __ccw_device_verify_start(cdev);
 454                 break;
 455         case -ETIME:            /* Set path group id stopped by timeout. */
 456                 ccw_device_verify_done(cdev, -ETIME);
 457                 break;
 458         case -EACCES:           /* channel is not operational. */
 459                 cdev->private->imask >>= 1;
 460                 cdev->private->iretry = 5;
 461                 __ccw_device_verify_start(cdev);
 462                 break;
 463         }
 464 }
 465
 466 void
 467 ccw_device_verify_start(struct ccw_device *cdev)
 468 {
 469         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 470
 471         cdev->private->flags.pgid_single = 0;
 472         cdev->private->imask = 0x80;
 473         cdev->private->iretry = 5;
 474
 475         /* Start with empty vpm. */
 476         sch->vpm = 0;
 477
 478         /* Get current pam. */
 479         if (stsch(sch->schid, &sch->schib)) {
 480                 ccw_device_verify_done(cdev, -ENODEV);
 481                 return;
 482         }
 483         __ccw_device_verify_start(cdev);
 484 }
 485
 486 static void
 487 __ccw_device_disband_start(struct ccw_device *cdev)
 488 {
 489         struct subchannel *sch;
 490         int ret;
 491
 492         sch = to_subchannel(cdev->dev.parent);
 493         while (cdev->private->imask != 0) {
 494                 if (sch->lpm & cdev->private->imask) {
 495                         ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
 496                         if (ret == 0)
 497                                 return;
 498                 }
 499                 cdev->private->iretry = 5;
 500                 cdev->private->imask >>= 1;
 501         }
 502         ccw_device_disband_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
 503 }
 504
 505 /*
 506  * Got interrupt for Unset Path Group ID.
 507  */
 508 void
 509 ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
 510 {
 511         struct subchannel *sch;
 512         struct irb *irb;
 513         int ret;
 514
 515         irb = (struct irb *) __LC_IRB;
 516
 517         if (irb->scsw.stctl ==
 518             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 519                 if (__ccw_device_should_retry(&irb->scsw))
 520                         __ccw_device_disband_start(cdev);
 521                 return;
 522         }
 523         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 524                 return;
 525         sch = to_subchannel(cdev->dev.parent);
 526         ret = __ccw_device_check_pgid(cdev);
 527         memset(&cdev->private->irb, 0, sizeof(struct irb));
 528         switch (ret) {
 529         /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
 530         case 0:                 /* disband successful. */
 531                 ccw_device_disband_done(cdev, ret);
 532                 break;
 533         case -EOPNOTSUPP:
 534                 /*
 535                  * One of those strange devices which claim to be able
 536                  * to do multipathing but not for Unset Path Group ID.
 537                  */
 538                 cdev->private->flags.pgid_single = 1;
 539                 /* fall through. */
 540         case -EAGAIN:           /* Try again. */
 541                 __ccw_device_disband_start(cdev);
 542                 break;
 543         case -ETIME:            /* Set path group id stopped by timeout. */
 544                 ccw_device_disband_done(cdev, -ETIME);
 545                 break;
 546         case -EACCES:           /* channel is not operational. */
 547                 cdev->private->imask >>= 1;
 548                 cdev->private->iretry = 5;
 549                 __ccw_device_disband_start(cdev);
 550                 break;
 551         }
 552 }
 553
 554 void
 555 ccw_device_disband_start(struct ccw_device *cdev)
 556 {
 557         cdev->private->flags.pgid_single = 0;
 558         cdev->private->iretry = 5;
 559         cdev->private->imask = 0x80;
 560         __ccw_device_disband_start(cdev);
 561 }