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