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 #include "io_sch.h"
  26
  27 /*
  28  * Helper function called from interrupt context to decide whether an
  29  * operation should be tried again.
  30  */
  31 static int __ccw_device_should_retry(struct scsw *scsw)
  32 {
  33         /* CC is only valid if start function bit is set. */
  34         if ((scsw->fctl & SCSW_FCTL_START_FUNC) && scsw->cc == 1)
  35                 return 1;
  36         /* No more activity. For sense and set PGID we stubbornly try again. */
  37         if (!scsw->actl)
  38                 return 1;
  39         return 0;
  40 }
  41
  42 /*
  43  * Start Sense Path Group ID helper function. Used in ccw_device_recog
  44  * and ccw_device_sense_pgid.
  45  */
  46 static int
  47 __ccw_device_sense_pgid_start(struct ccw_device *cdev)
  48 {
  49         struct subchannel *sch;
  50         struct ccw1 *ccw;
  51         int ret;
  52         int i;
  53
  54         sch = to_subchannel(cdev->dev.parent);
  55         /* Return if we already checked on all paths. */
  56         if (cdev->private->imask == 0)
  57                 return (sch->lpm == 0) ? -ENODEV : -EACCES;
  58         i = 8 - ffs(cdev->private->imask);
  59
  60         /* Setup sense path group id channel program. */
  61         ccw = cdev->private->iccws;
  62         ccw->cmd_code = CCW_CMD_SENSE_PGID;
  63         ccw->count = sizeof (struct pgid);
  64         ccw->flags = CCW_FLAG_SLI;
  65
  66         /* Reset device status. */
  67         memset(&cdev->private->irb, 0, sizeof(struct irb));
  68         /* Try on every path. */
  69         ret = -ENODEV;
  70         while (cdev->private->imask != 0) {
  71                 /* Try every path multiple times. */
  72                 ccw->cda = (__u32) __pa (&cdev->private->pgid[i]);
  73                 if (cdev->private->iretry > 0) {
  74                         cdev->private->iretry--;
  75                         /* Reset internal retry indication. */
  76                         cdev->private->flags.intretry = 0;
  77                         ret = cio_start (sch, cdev->private->iccws,
  78                                          cdev->private->imask);
  79                         /* ret is 0, -EBUSY, -EACCES or -ENODEV */
  80                         if (ret != -EACCES)
  81                                 return ret;
  82                         CIO_MSG_EVENT(3, "SNID - Device %04x on Subchannel "
  83                                       "0.%x.%04x, lpm %02X, became 'not "
  84                                       "operational'\n",
  85                                       cdev->private->dev_id.devno,
  86                                       sch->schid.ssid,
  87                                       sch->schid.sch_no, cdev->private->imask);
  88
  89                 }
  90                 cdev->private->imask >>= 1;
  91                 cdev->private->iretry = 5;
  92                 i++;
  93         }
  94
  95         return ret;
  96 }
  97
  98 void
  99 ccw_device_sense_pgid_start(struct ccw_device *cdev)
 100 {
 101         int ret;
 102
 103         /* Set a timeout of 60s */
 104         ccw_device_set_timeout(cdev, 60*HZ);
 105
 106         cdev->private->state = DEV_STATE_SENSE_PGID;
 107         cdev->private->imask = 0x80;
 108         cdev->private->iretry = 5;
 109         memset (&cdev->private->pgid, 0, sizeof (cdev->private->pgid));
 110         ret = __ccw_device_sense_pgid_start(cdev);
 111         if (ret && ret != -EBUSY)
 112                 ccw_device_sense_pgid_done(cdev, ret);
 113 }
 114
 115 /*
 116  * Called from interrupt context to check if a valid answer
 117  * to Sense Path Group ID was received.
 118  */
 119 static int
 120 __ccw_device_check_sense_pgid(struct ccw_device *cdev)
 121 {
 122         struct subchannel *sch;
 123         struct irb *irb;
 124         int i;
 125
 126         sch = to_subchannel(cdev->dev.parent);
 127         irb = &cdev->private->irb;
 128         if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
 129                 /* Retry Sense PGID if requested. */
 130                 if (cdev->private->flags.intretry) {
 131                         cdev->private->flags.intretry = 0;
 132                         return -EAGAIN;
 133                 }
 134                 return -ETIME;
 135         }
 136         if (irb->esw.esw0.erw.cons &&
 137             (irb->ecw[0]&(SNS0_CMD_REJECT|SNS0_INTERVENTION_REQ))) {
 138                 /*
 139                  * If the device doesn't support the Sense Path Group ID
 140                  *  command further retries wouldn't help ...
 141                  */
 142                 return -EOPNOTSUPP;
 143         }
 144         if (irb->esw.esw0.erw.cons) {
 145                 CIO_MSG_EVENT(2, "SNID - device 0.%x.%04x, unit check, "
 146                               "lpum %02X, cnt %02d, sns : "
 147                               "%02X%02X%02X%02X %02X%02X%02X%02X ...\n",
 148                               cdev->private->dev_id.ssid,
 149                               cdev->private->dev_id.devno,
 150                               irb->esw.esw0.sublog.lpum,
 151                               irb->esw.esw0.erw.scnt,
 152                               irb->ecw[0], irb->ecw[1],
 153                               irb->ecw[2], irb->ecw[3],
 154                               irb->ecw[4], irb->ecw[5],
 155                               irb->ecw[6], irb->ecw[7]);
 156                 return -EAGAIN;
 157         }
 158         if (irb->scsw.cc == 3) {
 159                 u8 lpm;
 160
 161                 lpm = to_io_private(sch)->orb.lpm;
 162                 CIO_MSG_EVENT(3, "SNID - Device %04x on Subchannel 0.%x.%04x,"
 163                               " lpm %02X, became 'not operational'\n",
 164                               cdev->private->dev_id.devno, sch->schid.ssid,
 165                               sch->schid.sch_no, lpm);
 166                 return -EACCES;
 167         }
 168         i = 8 - ffs(cdev->private->imask);
 169         if (cdev->private->pgid[i].inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
 170                 CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x "
 171                               "is reserved by someone else\n",
 172                               cdev->private->dev_id.devno, sch->schid.ssid,
 173                               sch->schid.sch_no);
 174                 return -EUSERS;
 175         }
 176         return 0;
 177 }
 178
 179 /*
 180  * Got interrupt for Sense Path Group ID.
 181  */
 182 void
 183 ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
 184 {
 185         struct subchannel *sch;
 186         struct irb *irb;
 187         int ret;
 188
 189         irb = (struct irb *) __LC_IRB;
 190
 191         if (irb->scsw.stctl ==
 192             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 193                 if (__ccw_device_should_retry(&irb->scsw)) {
 194                         ret = __ccw_device_sense_pgid_start(cdev);
 195                         if (ret && ret != -EBUSY)
 196                                 ccw_device_sense_pgid_done(cdev, ret);
 197                 }
 198                 return;
 199         }
 200         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 201                 return;
 202         sch = to_subchannel(cdev->dev.parent);
 203         ret = __ccw_device_check_sense_pgid(cdev);
 204         memset(&cdev->private->irb, 0, sizeof(struct irb));
 205         switch (ret) {
 206         /* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
 207         case -EOPNOTSUPP:       /* Sense Path Group ID not supported */
 208                 ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
 209                 break;
 210         case -ETIME:            /* Sense path group id stopped by timeout. */
 211                 ccw_device_sense_pgid_done(cdev, -ETIME);
 212                 break;
 213         case -EACCES:           /* channel is not operational. */
 214                 sch->lpm &= ~cdev->private->imask;
 215                 /* Fall through. */
 216         case 0:                 /* Sense Path Group ID successful. */
 217                 cdev->private->imask >>= 1;
 218                 cdev->private->iretry = 5;
 219                 /* Fall through. */
 220         case -EAGAIN:           /* Try again. */
 221                 ret = __ccw_device_sense_pgid_start(cdev);
 222                 if (ret != 0 && ret != -EBUSY)
 223                         ccw_device_sense_pgid_done(cdev, ret);
 224                 break;
 225         case -EUSERS:           /* device is reserved for someone else. */
 226                 ccw_device_sense_pgid_done(cdev, -EUSERS);
 227                 break;
 228         }
 229 }
 230
 231 /*
 232  * Path Group ID helper function.
 233  */
 234 static int
 235 __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
 236 {
 237         struct subchannel *sch;
 238         struct ccw1 *ccw;
 239         int ret;
 240
 241         sch = to_subchannel(cdev->dev.parent);
 242
 243         /* Setup sense path group id channel program. */
 244         cdev->private->pgid[0].inf.fc = func;
 245         ccw = cdev->private->iccws;
 246         if (cdev->private->flags.pgid_single)
 247                 cdev->private->pgid[0].inf.fc |= SPID_FUNC_SINGLE_PATH;
 248         else
 249                 cdev->private->pgid[0].inf.fc |= SPID_FUNC_MULTI_PATH;
 250         ccw->cmd_code = CCW_CMD_SET_PGID;
 251         ccw->cda = (__u32) __pa (&cdev->private->pgid[0]);
 252         ccw->count = sizeof (struct pgid);
 253         ccw->flags = CCW_FLAG_SLI;
 254
 255         /* Reset device status. */
 256         memset(&cdev->private->irb, 0, sizeof(struct irb));
 257
 258         /* Try multiple times. */
 259         ret = -EACCES;
 260         if (cdev->private->iretry > 0) {
 261                 cdev->private->iretry--;
 262                 /* Reset internal retry indication. */
 263                 cdev->private->flags.intretry = 0;
 264                 ret = cio_start (sch, cdev->private->iccws,
 265                                  cdev->private->imask);
 266                 /* We expect an interrupt in case of success or busy
 267                  * indication. */
 268                 if ((ret == 0) || (ret == -EBUSY))
 269                         return ret;
 270         }
 271         /* PGID command failed on this path. */
 272         CIO_MSG_EVENT(3, "SPID - Device %04x on Subchannel "
 273                       "0.%x.%04x, lpm %02X, became 'not operational'\n",
 274                       cdev->private->dev_id.devno, sch->schid.ssid,
 275                       sch->schid.sch_no, cdev->private->imask);
 276         return ret;
 277 }
 278
 279 /*
 280  * Helper function to send a nop ccw down a path.
 281  */
 282 static int __ccw_device_do_nop(struct ccw_device *cdev)
 283 {
 284         struct subchannel *sch;
 285         struct ccw1 *ccw;
 286         int ret;
 287
 288         sch = to_subchannel(cdev->dev.parent);
 289
 290         /* Setup nop channel program. */
 291         ccw = cdev->private->iccws;
 292         ccw->cmd_code = CCW_CMD_NOOP;
 293         ccw->cda = 0;
 294         ccw->count = 0;
 295         ccw->flags = CCW_FLAG_SLI;
 296
 297         /* Reset device status. */
 298         memset(&cdev->private->irb, 0, sizeof(struct irb));
 299
 300         /* Try multiple times. */
 301         ret = -EACCES;
 302         if (cdev->private->iretry > 0) {
 303                 cdev->private->iretry--;
 304                 /* Reset internal retry indication. */
 305                 cdev->private->flags.intretry = 0;
 306                 ret = cio_start (sch, cdev->private->iccws,
 307                                  cdev->private->imask);
 308                 /* We expect an interrupt in case of success or busy
 309                  * indication. */
 310                 if ((ret == 0) || (ret == -EBUSY))
 311                         return ret;
 312         }
 313         /* nop command failed on this path. */
 314         CIO_MSG_EVENT(3, "NOP - Device %04x on Subchannel "
 315                       "0.%x.%04x, lpm %02X, became 'not operational'\n",
 316                       cdev->private->dev_id.devno, sch->schid.ssid,
 317                       sch->schid.sch_no, cdev->private->imask);
 318         return ret;
 319 }
 320
 321
 322 /*
 323  * Called from interrupt context to check if a valid answer
 324  * to Set Path Group ID was received.
 325  */
 326 static int
 327 __ccw_device_check_pgid(struct ccw_device *cdev)
 328 {
 329         struct subchannel *sch;
 330         struct irb *irb;
 331
 332         sch = to_subchannel(cdev->dev.parent);
 333         irb = &cdev->private->irb;
 334         if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
 335                 /* Retry Set PGID if requested. */
 336                 if (cdev->private->flags.intretry) {
 337                         cdev->private->flags.intretry = 0;
 338                         return -EAGAIN;
 339                 }
 340                 return -ETIME;
 341         }
 342         if (irb->esw.esw0.erw.cons) {
 343                 if (irb->ecw[0] & SNS0_CMD_REJECT)
 344                         return -EOPNOTSUPP;
 345                 /* Hmm, whatever happened, try again. */
 346                 CIO_MSG_EVENT(2, "SPID - device 0.%x.%04x, unit check, "
 347                               "cnt %02d, "
 348                               "sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
 349                               cdev->private->dev_id.ssid,
 350                               cdev->private->dev_id.devno,
 351                               irb->esw.esw0.erw.scnt,
 352                               irb->ecw[0], irb->ecw[1],
 353                               irb->ecw[2], irb->ecw[3],
 354                               irb->ecw[4], irb->ecw[5],
 355                               irb->ecw[6], irb->ecw[7]);
 356                 return -EAGAIN;
 357         }
 358         if (irb->scsw.cc == 3) {
 359                 CIO_MSG_EVENT(3, "SPID - Device %04x on Subchannel 0.%x.%04x,"
 360                               " lpm %02X, became 'not operational'\n",
 361                               cdev->private->dev_id.devno, sch->schid.ssid,
 362                               sch->schid.sch_no, cdev->private->imask);
 363                 return -EACCES;
 364         }
 365         return 0;
 366 }
 367
 368 /*
 369  * Called from interrupt context to check the path status after a nop has
 370  * been send.
 371  */
 372 static int __ccw_device_check_nop(struct ccw_device *cdev)
 373 {
 374         struct subchannel *sch;
 375         struct irb *irb;
 376
 377         sch = to_subchannel(cdev->dev.parent);
 378         irb = &cdev->private->irb;
 379         if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
 380                 /* Retry NOP if requested. */
 381                 if (cdev->private->flags.intretry) {
 382                         cdev->private->flags.intretry = 0;
 383                         return -EAGAIN;
 384                 }
 385                 return -ETIME;
 386         }
 387         if (irb->scsw.cc == 3) {
 388                 CIO_MSG_EVENT(3, "NOP - Device %04x on Subchannel 0.%x.%04x,"
 389                               " lpm %02X, became 'not operational'\n",
 390                               cdev->private->dev_id.devno, sch->schid.ssid,
 391                               sch->schid.sch_no, cdev->private->imask);
 392                 return -EACCES;
 393         }
 394         return 0;
 395 }
 396
 397 static void
 398 __ccw_device_verify_start(struct ccw_device *cdev)
 399 {
 400         struct subchannel *sch;
 401         __u8 func;
 402         int ret;
 403
 404         sch = to_subchannel(cdev->dev.parent);
 405         /* Repeat for all paths. */
 406         for (; cdev->private->imask; cdev->private->imask >>= 1,
 407                                      cdev->private->iretry = 5) {
 408                 if ((cdev->private->imask & sch->schib.pmcw.pam) == 0)
 409                         /* Path not available, try next. */
 410                         continue;
 411                 if (cdev->private->options.pgroup) {
 412                         if (sch->opm & cdev->private->imask)
 413                                 func = SPID_FUNC_ESTABLISH;
 414                         else
 415                                 func = SPID_FUNC_RESIGN;
 416                         ret = __ccw_device_do_pgid(cdev, func);
 417                 } else
 418                         ret = __ccw_device_do_nop(cdev);
 419                 /* We expect an interrupt in case of success or busy
 420                  * indication. */
 421                 if (ret == 0 || ret == -EBUSY)
 422                         return;
 423                 /* Permanent path failure, try next. */
 424         }
 425         /* Done with all paths. */
 426         ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV);
 427 }
 428
 429 /*
 430  * Got interrupt for Set Path Group ID.
 431  */
 432 void
 433 ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
 434 {
 435         struct subchannel *sch;
 436         struct irb *irb;
 437         int ret;
 438
 439         irb = (struct irb *) __LC_IRB;
 440
 441         if (irb->scsw.stctl ==
 442             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 443                 if (__ccw_device_should_retry(&irb->scsw))
 444                         __ccw_device_verify_start(cdev);
 445                 return;
 446         }
 447         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 448                 return;
 449         sch = to_subchannel(cdev->dev.parent);
 450         if (cdev->private->options.pgroup)
 451                 ret = __ccw_device_check_pgid(cdev);
 452         else
 453                 ret = __ccw_device_check_nop(cdev);
 454         memset(&cdev->private->irb, 0, sizeof(struct irb));
 455
 456         switch (ret) {
 457         /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
 458         case 0:
 459                 /* Path verification ccw finished successfully, update lpm. */
 460                 sch->vpm |= sch->opm & cdev->private->imask;
 461                 /* Go on with next path. */
 462                 cdev->private->imask >>= 1;
 463                 cdev->private->iretry = 5;
 464                 __ccw_device_verify_start(cdev);
 465                 break;
 466         case -EOPNOTSUPP:
 467                 /*
 468                  * One of those strange devices which claim to be able
 469                  * to do multipathing but not for Set Path Group ID.
 470                  */
 471                 if (cdev->private->flags.pgid_single)
 472                         cdev->private->options.pgroup = 0;
 473                 else
 474                         cdev->private->flags.pgid_single = 1;
 475                 /* Retry */
 476                 sch->vpm = 0;
 477                 cdev->private->imask = 0x80;
 478                 cdev->private->iretry = 5;
 479                 /* fall through. */
 480         case -EAGAIN:           /* Try again. */
 481                 __ccw_device_verify_start(cdev);
 482                 break;
 483         case -ETIME:            /* Set path group id stopped by timeout. */
 484                 ccw_device_verify_done(cdev, -ETIME);
 485                 break;
 486         case -EACCES:           /* channel is not operational. */
 487                 cdev->private->imask >>= 1;
 488                 cdev->private->iretry = 5;
 489                 __ccw_device_verify_start(cdev);
 490                 break;
 491         }
 492 }
 493
 494 void
 495 ccw_device_verify_start(struct ccw_device *cdev)
 496 {
 497         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 498
 499         cdev->private->flags.pgid_single = 0;
 500         cdev->private->imask = 0x80;
 501         cdev->private->iretry = 5;
 502
 503         /* Start with empty vpm. */
 504         sch->vpm = 0;
 505
 506         /* Get current pam. */
 507         if (stsch(sch->schid, &sch->schib)) {
 508                 ccw_device_verify_done(cdev, -ENODEV);
 509                 return;
 510         }
 511         /* After 60s path verification is considered to have failed. */
 512         ccw_device_set_timeout(cdev, 60*HZ);
 513         __ccw_device_verify_start(cdev);
 514 }
 515
 516 static void
 517 __ccw_device_disband_start(struct ccw_device *cdev)
 518 {
 519         struct subchannel *sch;
 520         int ret;
 521
 522         sch = to_subchannel(cdev->dev.parent);
 523         while (cdev->private->imask != 0) {
 524                 if (sch->lpm & cdev->private->imask) {
 525                         ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
 526                         if (ret == 0)
 527                                 return;
 528                 }
 529                 cdev->private->iretry = 5;
 530                 cdev->private->imask >>= 1;
 531         }
 532         ccw_device_disband_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
 533 }
 534
 535 /*
 536  * Got interrupt for Unset Path Group ID.
 537  */
 538 void
 539 ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
 540 {
 541         struct subchannel *sch;
 542         struct irb *irb;
 543         int ret;
 544
 545         irb = (struct irb *) __LC_IRB;
 546
 547         if (irb->scsw.stctl ==
 548             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 549                 if (__ccw_device_should_retry(&irb->scsw))
 550                         __ccw_device_disband_start(cdev);
 551                 return;
 552         }
 553         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 554                 return;
 555         sch = to_subchannel(cdev->dev.parent);
 556         ret = __ccw_device_check_pgid(cdev);
 557         memset(&cdev->private->irb, 0, sizeof(struct irb));
 558         switch (ret) {
 559         /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
 560         case 0:                 /* disband successful. */
 561                 ccw_device_disband_done(cdev, ret);
 562                 break;
 563         case -EOPNOTSUPP:
 564                 /*
 565                  * One of those strange devices which claim to be able
 566                  * to do multipathing but not for Unset Path Group ID.
 567                  */
 568                 cdev->private->flags.pgid_single = 1;
 569                 /* fall through. */
 570         case -EAGAIN:           /* Try again. */
 571                 __ccw_device_disband_start(cdev);
 572                 break;
 573         case -ETIME:            /* Set path group id stopped by timeout. */
 574                 ccw_device_disband_done(cdev, -ETIME);
 575                 break;
 576         case -EACCES:           /* channel is not operational. */
 577                 cdev->private->imask >>= 1;
 578                 cdev->private->iretry = 5;
 579                 __ccw_device_disband_start(cdev);
 580                 break;
 581         }
 582 }
 583
 584 void
 585 ccw_device_disband_start(struct ccw_device *cdev)
 586 {
 587         /* After 60s disbanding is considered to have failed. */
 588         ccw_device_set_timeout(cdev, 60*HZ);
 589
 590         cdev->private->flags.pgid_single = 0;
 591         cdev->private->iretry = 5;
 592         cdev->private->imask = 0x80;
 593         __ccw_device_disband_start(cdev);
 594 }