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