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(2, "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(2, "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_MULTI_PATH;
 248                 ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
 249                 ccw->cda = 0;
 250                 ccw->count = 0;
 251                 ccw->flags = CCW_FLAG_SLI | CCW_FLAG_CC;
 252                 ccw++;
 253         } else
 254                 cdev->private->pgid[0].inf.fc |= SPID_FUNC_SINGLE_PATH;
 255
 256         ccw->cmd_code = CCW_CMD_SET_PGID;
 257         ccw->cda = (__u32) __pa (&cdev->private->pgid[0]);
 258         ccw->count = sizeof (struct pgid);
 259         ccw->flags = CCW_FLAG_SLI;
 260
 261         /* Reset device status. */
 262         memset(&cdev->private->irb, 0, sizeof(struct irb));
 263
 264         /* Try multiple times. */
 265         ret = -EACCES;
 266         if (cdev->private->iretry > 0) {
 267                 cdev->private->iretry--;
 268                 /* Reset internal retry indication. */
 269                 cdev->private->flags.intretry = 0;
 270                 ret = cio_start (sch, cdev->private->iccws,
 271                                  cdev->private->imask);
 272                 /* We expect an interrupt in case of success or busy
 273                  * indication. */
 274                 if ((ret == 0) || (ret == -EBUSY))
 275                         return ret;
 276         }
 277         /* PGID command failed on this path. */
 278         CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
 279                       "0.%x.%04x, lpm %02X, became 'not operational'\n",
 280                       cdev->private->dev_id.devno, sch->schid.ssid,
 281                       sch->schid.sch_no, cdev->private->imask);
 282         return ret;
 283 }
 284
 285 /*
 286  * Helper function to send a nop ccw down a path.
 287  */
 288 static int __ccw_device_do_nop(struct ccw_device *cdev)
 289 {
 290         struct subchannel *sch;
 291         struct ccw1 *ccw;
 292         int ret;
 293
 294         sch = to_subchannel(cdev->dev.parent);
 295
 296         /* Setup nop channel program. */
 297         ccw = cdev->private->iccws;
 298         ccw->cmd_code = CCW_CMD_NOOP;
 299         ccw->cda = 0;
 300         ccw->count = 0;
 301         ccw->flags = CCW_FLAG_SLI;
 302
 303         /* Reset device status. */
 304         memset(&cdev->private->irb, 0, sizeof(struct irb));
 305
 306         /* Try multiple times. */
 307         ret = -EACCES;
 308         if (cdev->private->iretry > 0) {
 309                 cdev->private->iretry--;
 310                 /* Reset internal retry indication. */
 311                 cdev->private->flags.intretry = 0;
 312                 ret = cio_start (sch, cdev->private->iccws,
 313                                  cdev->private->imask);
 314                 /* We expect an interrupt in case of success or busy
 315                  * indication. */
 316                 if ((ret == 0) || (ret == -EBUSY))
 317                         return ret;
 318         }
 319         /* nop command failed on this path. */
 320         CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel "
 321                       "0.%x.%04x, lpm %02X, became 'not operational'\n",
 322                       cdev->private->dev_id.devno, sch->schid.ssid,
 323                       sch->schid.sch_no, cdev->private->imask);
 324         return ret;
 325 }
 326
 327
 328 /*
 329  * Called from interrupt context to check if a valid answer
 330  * to Set Path Group ID was received.
 331  */
 332 static int
 333 __ccw_device_check_pgid(struct ccw_device *cdev)
 334 {
 335         struct subchannel *sch;
 336         struct irb *irb;
 337
 338         sch = to_subchannel(cdev->dev.parent);
 339         irb = &cdev->private->irb;
 340         if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
 341                 /* Retry Set PGID if requested. */
 342                 if (cdev->private->flags.intretry) {
 343                         cdev->private->flags.intretry = 0;
 344                         return -EAGAIN;
 345                 }
 346                 return -ETIME;
 347         }
 348         if (irb->esw.esw0.erw.cons) {
 349                 if (irb->ecw[0] & SNS0_CMD_REJECT)
 350                         return -EOPNOTSUPP;
 351                 /* Hmm, whatever happened, try again. */
 352                 CIO_MSG_EVENT(2, "SPID - device 0.%x.%04x, unit check, "
 353                               "cnt %02d, "
 354                               "sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
 355                               cdev->private->dev_id.ssid,
 356                               cdev->private->dev_id.devno,
 357                               irb->esw.esw0.erw.scnt,
 358                               irb->ecw[0], irb->ecw[1],
 359                               irb->ecw[2], irb->ecw[3],
 360                               irb->ecw[4], irb->ecw[5],
 361                               irb->ecw[6], irb->ecw[7]);
 362                 return -EAGAIN;
 363         }
 364         if (irb->scsw.cc == 3) {
 365                 CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel 0.%x.%04x,"
 366                               " lpm %02X, became 'not operational'\n",
 367                               cdev->private->dev_id.devno, sch->schid.ssid,
 368                               sch->schid.sch_no, cdev->private->imask);
 369                 return -EACCES;
 370         }
 371         return 0;
 372 }
 373
 374 /*
 375  * Called from interrupt context to check the path status after a nop has
 376  * been send.
 377  */
 378 static int __ccw_device_check_nop(struct ccw_device *cdev)
 379 {
 380         struct subchannel *sch;
 381         struct irb *irb;
 382
 383         sch = to_subchannel(cdev->dev.parent);
 384         irb = &cdev->private->irb;
 385         if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
 386                 /* Retry NOP if requested. */
 387                 if (cdev->private->flags.intretry) {
 388                         cdev->private->flags.intretry = 0;
 389                         return -EAGAIN;
 390                 }
 391                 return -ETIME;
 392         }
 393         if (irb->scsw.cc == 3) {
 394                 CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel 0.%x.%04x,"
 395                               " lpm %02X, became 'not operational'\n",
 396                               cdev->private->dev_id.devno, sch->schid.ssid,
 397                               sch->schid.sch_no, cdev->private->imask);
 398                 return -EACCES;
 399         }
 400         return 0;
 401 }
 402
 403 static void
 404 __ccw_device_verify_start(struct ccw_device *cdev)
 405 {
 406         struct subchannel *sch;
 407         __u8 func;
 408         int ret;
 409
 410         sch = to_subchannel(cdev->dev.parent);
 411         /* Repeat for all paths. */
 412         for (; cdev->private->imask; cdev->private->imask >>= 1,
 413                                      cdev->private->iretry = 5) {
 414                 if ((cdev->private->imask & sch->schib.pmcw.pam) == 0)
 415                         /* Path not available, try next. */
 416                         continue;
 417                 if (cdev->private->options.pgroup) {
 418                         if (sch->opm & cdev->private->imask)
 419                                 func = SPID_FUNC_ESTABLISH;
 420                         else
 421                                 func = SPID_FUNC_RESIGN;
 422                         ret = __ccw_device_do_pgid(cdev, func);
 423                 } else
 424                         ret = __ccw_device_do_nop(cdev);
 425                 /* We expect an interrupt in case of success or busy
 426                  * indication. */
 427                 if (ret == 0 || ret == -EBUSY)
 428                         return;
 429                 /* Permanent path failure, try next. */
 430         }
 431         /* Done with all paths. */
 432         ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV);
 433 }
 434
 435 /*
 436  * Got interrupt for Set Path Group ID.
 437  */
 438 void
 439 ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
 440 {
 441         struct subchannel *sch;
 442         struct irb *irb;
 443         int ret;
 444
 445         irb = (struct irb *) __LC_IRB;
 446
 447         if (irb->scsw.stctl ==
 448             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 449                 if (__ccw_device_should_retry(&irb->scsw))
 450                         __ccw_device_verify_start(cdev);
 451                 return;
 452         }
 453         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 454                 return;
 455         sch = to_subchannel(cdev->dev.parent);
 456         if (cdev->private->options.pgroup)
 457                 ret = __ccw_device_check_pgid(cdev);
 458         else
 459                 ret = __ccw_device_check_nop(cdev);
 460         memset(&cdev->private->irb, 0, sizeof(struct irb));
 461
 462         switch (ret) {
 463         /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
 464         case 0:
 465                 /* Path verification ccw finished successfully, update lpm. */
 466                 sch->vpm |= sch->opm & cdev->private->imask;
 467                 /* Go on with next path. */
 468                 cdev->private->imask >>= 1;
 469                 cdev->private->iretry = 5;
 470                 __ccw_device_verify_start(cdev);
 471                 break;
 472         case -EOPNOTSUPP:
 473                 /*
 474                  * One of those strange devices which claim to be able
 475                  * to do multipathing but not for Set Path Group ID.
 476                  */
 477                 if (cdev->private->flags.pgid_single)
 478                         cdev->private->options.pgroup = 0;
 479                 else
 480                         cdev->private->flags.pgid_single = 1;
 481                 /* Retry */
 482                 sch->vpm = 0;
 483                 cdev->private->imask = 0x80;
 484                 cdev->private->iretry = 5;
 485                 /* fall through. */
 486         case -EAGAIN:           /* Try again. */
 487                 __ccw_device_verify_start(cdev);
 488                 break;
 489         case -ETIME:            /* Set path group id stopped by timeout. */
 490                 ccw_device_verify_done(cdev, -ETIME);
 491                 break;
 492         case -EACCES:           /* channel is not operational. */
 493                 cdev->private->imask >>= 1;
 494                 cdev->private->iretry = 5;
 495                 __ccw_device_verify_start(cdev);
 496                 break;
 497         }
 498 }
 499
 500 void
 501 ccw_device_verify_start(struct ccw_device *cdev)
 502 {
 503         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 504
 505         cdev->private->flags.pgid_single = 0;
 506         cdev->private->imask = 0x80;
 507         cdev->private->iretry = 5;
 508
 509         /* Start with empty vpm. */
 510         sch->vpm = 0;
 511
 512         /* Get current pam. */
 513         if (stsch(sch->schid, &sch->schib)) {
 514                 ccw_device_verify_done(cdev, -ENODEV);
 515                 return;
 516         }
 517         /* After 60s path verification is considered to have failed. */
 518         ccw_device_set_timeout(cdev, 60*HZ);
 519         __ccw_device_verify_start(cdev);
 520 }
 521
 522 static void
 523 __ccw_device_disband_start(struct ccw_device *cdev)
 524 {
 525         struct subchannel *sch;
 526         int ret;
 527
 528         sch = to_subchannel(cdev->dev.parent);
 529         while (cdev->private->imask != 0) {
 530                 if (sch->lpm & cdev->private->imask) {
 531                         ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
 532                         if (ret == 0)
 533                                 return;
 534                 }
 535                 cdev->private->iretry = 5;
 536                 cdev->private->imask >>= 1;
 537         }
 538         ccw_device_disband_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
 539 }
 540
 541 /*
 542  * Got interrupt for Unset Path Group ID.
 543  */
 544 void
 545 ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
 546 {
 547         struct subchannel *sch;
 548         struct irb *irb;
 549         int ret;
 550
 551         irb = (struct irb *) __LC_IRB;
 552
 553         if (irb->scsw.stctl ==
 554             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 555                 if (__ccw_device_should_retry(&irb->scsw))
 556                         __ccw_device_disband_start(cdev);
 557                 return;
 558         }
 559         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 560                 return;
 561         sch = to_subchannel(cdev->dev.parent);
 562         ret = __ccw_device_check_pgid(cdev);
 563         memset(&cdev->private->irb, 0, sizeof(struct irb));
 564         switch (ret) {
 565         /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
 566         case 0:                 /* disband successful. */
 567                 ccw_device_disband_done(cdev, ret);
 568                 break;
 569         case -EOPNOTSUPP:
 570                 /*
 571                  * One of those strange devices which claim to be able
 572                  * to do multipathing but not for Unset Path Group ID.
 573                  */
 574                 cdev->private->flags.pgid_single = 1;
 575                 /* fall through. */
 576         case -EAGAIN:           /* Try again. */
 577                 __ccw_device_disband_start(cdev);
 578                 break;
 579         case -ETIME:            /* Set path group id stopped by timeout. */
 580                 ccw_device_disband_done(cdev, -ETIME);
 581                 break;
 582         case -EACCES:           /* channel is not operational. */
 583                 cdev->private->imask >>= 1;
 584                 cdev->private->iretry = 5;
 585                 __ccw_device_disband_start(cdev);
 586                 break;
 587         }
 588 }
 589
 590 void
 591 ccw_device_disband_start(struct ccw_device *cdev)
 592 {
 593         /* After 60s disbanding is considered to have failed. */
 594         ccw_device_set_timeout(cdev, 60*HZ);
 595
 596         cdev->private->flags.pgid_single = 0;
 597         cdev->private->iretry = 5;
 598         cdev->private->imask = 0x80;
 599         __ccw_device_disband_start(cdev);
 600 }