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                         /* Reset internal retry indication. */
  75                         cdev->private->flags.intretry = 0;
  76                         ret = cio_start (sch, cdev->private->iccws,
  77                                          cdev->private->imask);
  78                         /* ret is 0, -EBUSY, -EACCES or -ENODEV */
  79                         if (ret != -EACCES)
  80                                 return ret;
  81                         CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel "
  82                                       "0.%x.%04x, lpm %02X, became 'not "
  83                                       "operational'\n",
  84                                       cdev->private->dev_id.devno,
  85                                       sch->schid.ssid,
  86                                       sch->schid.sch_no, cdev->private->imask);
  87
  88                 }
  89                 cdev->private->imask >>= 1;
  90                 cdev->private->iretry = 5;
  91                 i++;
  92         }
  93
  94         return ret;
  95 }
  96
  97 void
  98 ccw_device_sense_pgid_start(struct ccw_device *cdev)
  99 {
 100         int ret;
 101
 102         /* Set a timeout of 60s */
 103         ccw_device_set_timeout(cdev, 60*HZ);
 104
 105         cdev->private->state = DEV_STATE_SENSE_PGID;
 106         cdev->private->imask = 0x80;
 107         cdev->private->iretry = 5;
 108         memset (&cdev->private->pgid, 0, sizeof (cdev->private->pgid));
 109         ret = __ccw_device_sense_pgid_start(cdev);
 110         if (ret && ret != -EBUSY)
 111                 ccw_device_sense_pgid_done(cdev, ret);
 112 }
 113
 114 /*
 115  * Called from interrupt context to check if a valid answer
 116  * to Sense Path Group ID was received.
 117  */
 118 static int
 119 __ccw_device_check_sense_pgid(struct ccw_device *cdev)
 120 {
 121         struct subchannel *sch;
 122         struct irb *irb;
 123         int i;
 124
 125         sch = to_subchannel(cdev->dev.parent);
 126         irb = &cdev->private->irb;
 127         if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
 128                 /* Retry Sense PGID if requested. */
 129                 if (cdev->private->flags.intretry) {
 130                         cdev->private->flags.intretry = 0;
 131                         return -EAGAIN;
 132                 }
 133                 return -ETIME;
 134         }
 135         if (irb->esw.esw0.erw.cons &&
 136             (irb->ecw[0]&(SNS0_CMD_REJECT|SNS0_INTERVENTION_REQ))) {
 137                 /*
 138                  * If the device doesn't support the Sense Path Group ID
 139                  *  command further retries wouldn't help ...
 140                  */
 141                 return -EOPNOTSUPP;
 142         }
 143         if (irb->esw.esw0.erw.cons) {
 144                 CIO_MSG_EVENT(2, "SNID - device 0.%x.%04x, unit check, "
 145                               "lpum %02X, cnt %02d, sns : "
 146                               "%02X%02X%02X%02X %02X%02X%02X%02X ...\n",
 147                               cdev->private->dev_id.ssid,
 148                               cdev->private->dev_id.devno,
 149                               irb->esw.esw0.sublog.lpum,
 150                               irb->esw.esw0.erw.scnt,
 151                               irb->ecw[0], irb->ecw[1],
 152                               irb->ecw[2], irb->ecw[3],
 153                               irb->ecw[4], irb->ecw[5],
 154                               irb->ecw[6], irb->ecw[7]);
 155                 return -EAGAIN;
 156         }
 157         if (irb->scsw.cc == 3) {
 158                 CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x,"
 159                               " lpm %02X, became 'not operational'\n",
 160                               cdev->private->dev_id.devno, sch->schid.ssid,
 161                               sch->schid.sch_no, sch->orb.lpm);
 162                 return -EACCES;
 163         }
 164         i = 8 - ffs(cdev->private->imask);
 165         if (cdev->private->pgid[i].inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
 166                 CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x "
 167                               "is reserved by someone else\n",
 168                               cdev->private->dev_id.devno, sch->schid.ssid,
 169                               sch->schid.sch_no);
 170                 return -EUSERS;
 171         }
 172         return 0;
 173 }
 174
 175 /*
 176  * Got interrupt for Sense Path Group ID.
 177  */
 178 void
 179 ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
 180 {
 181         struct subchannel *sch;
 182         struct irb *irb;
 183         int ret;
 184
 185         irb = (struct irb *) __LC_IRB;
 186
 187         if (irb->scsw.stctl ==
 188             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 189                 if (__ccw_device_should_retry(&irb->scsw)) {
 190                         ret = __ccw_device_sense_pgid_start(cdev);
 191                         if (ret && ret != -EBUSY)
 192                                 ccw_device_sense_pgid_done(cdev, ret);
 193                 }
 194                 return;
 195         }
 196         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 197                 return;
 198         sch = to_subchannel(cdev->dev.parent);
 199         ret = __ccw_device_check_sense_pgid(cdev);
 200         memset(&cdev->private->irb, 0, sizeof(struct irb));
 201         switch (ret) {
 202         /* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
 203         case -EOPNOTSUPP:       /* Sense Path Group ID not supported */
 204                 ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
 205                 break;
 206         case -ETIME:            /* Sense path group id stopped by timeout. */
 207                 ccw_device_sense_pgid_done(cdev, -ETIME);
 208                 break;
 209         case -EACCES:           /* channel is not operational. */
 210                 sch->lpm &= ~cdev->private->imask;
 211                 /* Fall through. */
 212         case 0:                 /* Sense Path Group ID successful. */
 213                 cdev->private->imask >>= 1;
 214                 cdev->private->iretry = 5;
 215                 /* Fall through. */
 216         case -EAGAIN:           /* Try again. */
 217                 ret = __ccw_device_sense_pgid_start(cdev);
 218                 if (ret != 0 && ret != -EBUSY)
 219                         ccw_device_sense_pgid_done(cdev, ret);
 220                 break;
 221         case -EUSERS:           /* device is reserved for someone else. */
 222                 ccw_device_sense_pgid_done(cdev, -EUSERS);
 223                 break;
 224         }
 225 }
 226
 227 /*
 228  * Path Group ID helper function.
 229  */
 230 static int
 231 __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
 232 {
 233         struct subchannel *sch;
 234         struct ccw1 *ccw;
 235         int ret;
 236
 237         sch = to_subchannel(cdev->dev.parent);
 238
 239         /* Setup sense path group id channel program. */
 240         cdev->private->pgid[0].inf.fc = func;
 241         ccw = cdev->private->iccws;
 242         if (!cdev->private->flags.pgid_single) {
 243                 cdev->private->pgid[0].inf.fc |= SPID_FUNC_MULTI_PATH;
 244                 ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
 245                 ccw->cda = 0;
 246                 ccw->count = 0;
 247                 ccw->flags = CCW_FLAG_SLI | CCW_FLAG_CC;
 248                 ccw++;
 249         } else
 250                 cdev->private->pgid[0].inf.fc |= SPID_FUNC_SINGLE_PATH;
 251
 252         ccw->cmd_code = CCW_CMD_SET_PGID;
 253         ccw->cda = (__u32) __pa (&cdev->private->pgid[0]);
 254         ccw->count = sizeof (struct pgid);
 255         ccw->flags = CCW_FLAG_SLI;
 256
 257         /* Reset device status. */
 258         memset(&cdev->private->irb, 0, sizeof(struct irb));
 259
 260         /* Try multiple times. */
 261         ret = -EACCES;
 262         if (cdev->private->iretry > 0) {
 263                 cdev->private->iretry--;
 264                 /* Reset internal retry indication. */
 265                 cdev->private->flags.intretry = 0;
 266                 ret = cio_start (sch, cdev->private->iccws,
 267                                  cdev->private->imask);
 268                 /* We expect an interrupt in case of success or busy
 269                  * indication. */
 270                 if ((ret == 0) || (ret == -EBUSY))
 271                         return ret;
 272         }
 273         /* PGID command failed on this path. */
 274         CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
 275                       "0.%x.%04x, lpm %02X, became 'not operational'\n",
 276                       cdev->private->dev_id.devno, sch->schid.ssid,
 277                       sch->schid.sch_no, cdev->private->imask);
 278         return ret;
 279 }
 280
 281 /*
 282  * Helper function to send a nop ccw down a path.
 283  */
 284 static int __ccw_device_do_nop(struct ccw_device *cdev)
 285 {
 286         struct subchannel *sch;
 287         struct ccw1 *ccw;
 288         int ret;
 289
 290         sch = to_subchannel(cdev->dev.parent);
 291
 292         /* Setup nop channel program. */
 293         ccw = cdev->private->iccws;
 294         ccw->cmd_code = CCW_CMD_NOOP;
 295         ccw->cda = 0;
 296         ccw->count = 0;
 297         ccw->flags = CCW_FLAG_SLI;
 298
 299         /* Reset device status. */
 300         memset(&cdev->private->irb, 0, sizeof(struct irb));
 301
 302         /* Try multiple times. */
 303         ret = -EACCES;
 304         if (cdev->private->iretry > 0) {
 305                 cdev->private->iretry--;
 306                 /* Reset internal retry indication. */
 307                 cdev->private->flags.intretry = 0;
 308                 ret = cio_start (sch, cdev->private->iccws,
 309                                  cdev->private->imask);
 310                 /* We expect an interrupt in case of success or busy
 311                  * indication. */
 312                 if ((ret == 0) || (ret == -EBUSY))
 313                         return ret;
 314         }
 315         /* nop command failed on this path. */
 316         CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel "
 317                       "0.%x.%04x, lpm %02X, became 'not operational'\n",
 318                       cdev->private->dev_id.devno, sch->schid.ssid,
 319                       sch->schid.sch_no, cdev->private->imask);
 320         return ret;
 321 }
 322
 323
 324 /*
 325  * Called from interrupt context to check if a valid answer
 326  * to Set Path Group ID was received.
 327  */
 328 static int
 329 __ccw_device_check_pgid(struct ccw_device *cdev)
 330 {
 331         struct subchannel *sch;
 332         struct irb *irb;
 333
 334         sch = to_subchannel(cdev->dev.parent);
 335         irb = &cdev->private->irb;
 336         if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
 337                 /* Retry Set PGID if requested. */
 338                 if (cdev->private->flags.intretry) {
 339                         cdev->private->flags.intretry = 0;
 340                         return -EAGAIN;
 341                 }
 342                 return -ETIME;
 343         }
 344         if (irb->esw.esw0.erw.cons) {
 345                 if (irb->ecw[0] & SNS0_CMD_REJECT)
 346                         return -EOPNOTSUPP;
 347                 /* Hmm, whatever happened, try again. */
 348                 CIO_MSG_EVENT(2, "SPID - device 0.%x.%04x, unit check, "
 349                               "cnt %02d, "
 350                               "sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
 351                               cdev->private->dev_id.ssid,
 352                               cdev->private->dev_id.devno,
 353                               irb->esw.esw0.erw.scnt,
 354                               irb->ecw[0], irb->ecw[1],
 355                               irb->ecw[2], irb->ecw[3],
 356                               irb->ecw[4], irb->ecw[5],
 357                               irb->ecw[6], irb->ecw[7]);
 358                 return -EAGAIN;
 359         }
 360         if (irb->scsw.cc == 3) {
 361                 CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel 0.%x.%04x,"
 362                               " lpm %02X, became 'not operational'\n",
 363                               cdev->private->dev_id.devno, sch->schid.ssid,
 364                               sch->schid.sch_no, cdev->private->imask);
 365                 return -EACCES;
 366         }
 367         return 0;
 368 }
 369
 370 /*
 371  * Called from interrupt context to check the path status after a nop has
 372  * been send.
 373  */
 374 static int __ccw_device_check_nop(struct ccw_device *cdev)
 375 {
 376         struct subchannel *sch;
 377         struct irb *irb;
 378
 379         sch = to_subchannel(cdev->dev.parent);
 380         irb = &cdev->private->irb;
 381         if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
 382                 /* Retry NOP if requested. */
 383                 if (cdev->private->flags.intretry) {
 384                         cdev->private->flags.intretry = 0;
 385                         return -EAGAIN;
 386                 }
 387                 return -ETIME;
 388         }
 389         if (irb->scsw.cc == 3) {
 390                 CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel 0.%x.%04x,"
 391                               " lpm %02X, became 'not operational'\n",
 392                               cdev->private->dev_id.devno, sch->schid.ssid,
 393                               sch->schid.sch_no, cdev->private->imask);
 394                 return -EACCES;
 395         }
 396         return 0;
 397 }
 398
 399 static void
 400 __ccw_device_verify_start(struct ccw_device *cdev)
 401 {
 402         struct subchannel *sch;
 403         __u8 func;
 404         int ret;
 405
 406         sch = to_subchannel(cdev->dev.parent);
 407         /* Repeat for all paths. */
 408         for (; cdev->private->imask; cdev->private->imask >>= 1,
 409                                      cdev->private->iretry = 5) {
 410                 if ((cdev->private->imask & sch->schib.pmcw.pam) == 0)
 411                         /* Path not available, try next. */
 412                         continue;
 413                 if (cdev->private->options.pgroup) {
 414                         if (sch->opm & cdev->private->imask)
 415                                 func = SPID_FUNC_ESTABLISH;
 416                         else
 417                                 func = SPID_FUNC_RESIGN;
 418                         ret = __ccw_device_do_pgid(cdev, func);
 419                 } else
 420                         ret = __ccw_device_do_nop(cdev);
 421                 /* We expect an interrupt in case of success or busy
 422                  * indication. */
 423                 if (ret == 0 || ret == -EBUSY)
 424                         return;
 425                 /* Permanent path failure, try next. */
 426         }
 427         /* Done with all paths. */
 428         ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV);
 429 }
 430
 431 /*
 432  * Got interrupt for Set Path Group ID.
 433  */
 434 void
 435 ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
 436 {
 437         struct subchannel *sch;
 438         struct irb *irb;
 439         int ret;
 440
 441         irb = (struct irb *) __LC_IRB;
 442
 443         if (irb->scsw.stctl ==
 444             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 445                 if (__ccw_device_should_retry(&irb->scsw))
 446                         __ccw_device_verify_start(cdev);
 447                 return;
 448         }
 449         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 450                 return;
 451         sch = to_subchannel(cdev->dev.parent);
 452         if (cdev->private->options.pgroup)
 453                 ret = __ccw_device_check_pgid(cdev);
 454         else
 455                 ret = __ccw_device_check_nop(cdev);
 456         memset(&cdev->private->irb, 0, sizeof(struct irb));
 457
 458         switch (ret) {
 459         /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
 460         case 0:
 461                 /* Path verification ccw finished successfully, update lpm. */
 462                 sch->vpm |= sch->opm & cdev->private->imask;
 463                 /* Go on with next path. */
 464                 cdev->private->imask >>= 1;
 465                 cdev->private->iretry = 5;
 466                 __ccw_device_verify_start(cdev);
 467                 break;
 468         case -EOPNOTSUPP:
 469                 /*
 470                  * One of those strange devices which claim to be able
 471                  * to do multipathing but not for Set Path Group ID.
 472                  */
 473                 if (cdev->private->flags.pgid_single)
 474                         cdev->private->options.pgroup = 0;
 475                 else
 476                         cdev->private->flags.pgid_single = 1;
 477                 /* Retry */
 478                 sch->vpm = 0;
 479                 cdev->private->imask = 0x80;
 480                 cdev->private->iretry = 5;
 481                 /* fall through. */
 482         case -EAGAIN:           /* Try again. */
 483                 __ccw_device_verify_start(cdev);
 484                 break;
 485         case -ETIME:            /* Set path group id stopped by timeout. */
 486                 ccw_device_verify_done(cdev, -ETIME);
 487                 break;
 488         case -EACCES:           /* channel is not operational. */
 489                 cdev->private->imask >>= 1;
 490                 cdev->private->iretry = 5;
 491                 __ccw_device_verify_start(cdev);
 492                 break;
 493         }
 494 }
 495
 496 void
 497 ccw_device_verify_start(struct ccw_device *cdev)
 498 {
 499         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 500
 501         cdev->private->flags.pgid_single = 0;
 502         cdev->private->imask = 0x80;
 503         cdev->private->iretry = 5;
 504
 505         /* Start with empty vpm. */
 506         sch->vpm = 0;
 507
 508         /* Get current pam. */
 509         if (stsch(sch->schid, &sch->schib)) {
 510                 ccw_device_verify_done(cdev, -ENODEV);
 511                 return;
 512         }
 513         /* After 60s path verification is considered to have failed. */
 514         ccw_device_set_timeout(cdev, 60*HZ);
 515         __ccw_device_verify_start(cdev);
 516 }
 517
 518 static void
 519 __ccw_device_disband_start(struct ccw_device *cdev)
 520 {
 521         struct subchannel *sch;
 522         int ret;
 523
 524         sch = to_subchannel(cdev->dev.parent);
 525         while (cdev->private->imask != 0) {
 526                 if (sch->lpm & cdev->private->imask) {
 527                         ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
 528                         if (ret == 0)
 529                                 return;
 530                 }
 531                 cdev->private->iretry = 5;
 532                 cdev->private->imask >>= 1;
 533         }
 534         ccw_device_disband_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
 535 }
 536
 537 /*
 538  * Got interrupt for Unset Path Group ID.
 539  */
 540 void
 541 ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
 542 {
 543         struct subchannel *sch;
 544         struct irb *irb;
 545         int ret;
 546
 547         irb = (struct irb *) __LC_IRB;
 548
 549         if (irb->scsw.stctl ==
 550             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 551                 if (__ccw_device_should_retry(&irb->scsw))
 552                         __ccw_device_disband_start(cdev);
 553                 return;
 554         }
 555         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 556                 return;
 557         sch = to_subchannel(cdev->dev.parent);
 558         ret = __ccw_device_check_pgid(cdev);
 559         memset(&cdev->private->irb, 0, sizeof(struct irb));
 560         switch (ret) {
 561         /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
 562         case 0:                 /* disband successful. */
 563                 ccw_device_disband_done(cdev, ret);
 564                 break;
 565         case -EOPNOTSUPP:
 566                 /*
 567                  * One of those strange devices which claim to be able
 568                  * to do multipathing but not for Unset Path Group ID.
 569                  */
 570                 cdev->private->flags.pgid_single = 1;
 571                 /* fall through. */
 572         case -EAGAIN:           /* Try again. */
 573                 __ccw_device_disband_start(cdev);
 574                 break;
 575         case -ETIME:            /* Set path group id stopped by timeout. */
 576                 ccw_device_disband_done(cdev, -ETIME);
 577                 break;
 578         case -EACCES:           /* channel is not operational. */
 579                 cdev->private->imask >>= 1;
 580                 cdev->private->iretry = 5;
 581                 __ccw_device_disband_start(cdev);
 582                 break;
 583         }
 584 }
 585
 586 void
 587 ccw_device_disband_start(struct ccw_device *cdev)
 588 {
 589         /* After 60s disbanding is considered to have failed. */
 590         ccw_device_set_timeout(cdev, 60*HZ);
 591
 592         cdev->private->flags.pgid_single = 0;
 593         cdev->private->iretry = 5;
 594         cdev->private->imask = 0x80;
 595         __ccw_device_disband_start(cdev);
 596 }