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