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/config.h>
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15
  16 #include <asm/ccwdev.h>
  17 #include <asm/cio.h>
  18 #include <asm/delay.h>
  19 #include <asm/lowcore.h>
  20
  21 #include "cio.h"
  22 #include "cio_debug.h"
  23 #include "css.h"
  24 #include "device.h"
  25 #include "ioasm.h"
  26
  27 /*
  28  * Start Sense Path Group ID helper function. Used in ccw_device_recog
  29  * and ccw_device_sense_pgid.
  30  */
  31 static int
  32 __ccw_device_sense_pgid_start(struct ccw_device *cdev)
  33 {
  34         struct subchannel *sch;
  35         struct ccw1 *ccw;
  36         int ret;
  37
  38         sch = to_subchannel(cdev->dev.parent);
  39         /* Setup sense path group id channel program. */
  40         ccw = cdev->private->iccws;
  41         ccw->cmd_code = CCW_CMD_SENSE_PGID;
  42         ccw->cda = (__u32) __pa (&cdev->private->pgid);
  43         ccw->count = sizeof (struct pgid);
  44         ccw->flags = CCW_FLAG_SLI;
  45
  46         /* Reset device status. */
  47         memset(&cdev->private->irb, 0, sizeof(struct irb));
  48         /* Try on every path. */
  49         ret = -ENODEV;
  50         while (cdev->private->imask != 0) {
  51                 /* Try every path multiple times. */
  52                 if (cdev->private->iretry > 0) {
  53                         cdev->private->iretry--;
  54                         ret = cio_start (sch, cdev->private->iccws,
  55                                          cdev->private->imask);
  56                         /* ret is 0, -EBUSY, -EACCES or -ENODEV */
  57                         if (ret != -EACCES)
  58                                 return ret;
  59                         CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel "
  60                                       "0.%x.%04x, lpm %02X, became 'not "
  61                                       "operational'\n",
  62                                       cdev->private->devno, sch->schid.ssid,
  63                                       sch->schid.sch_no, cdev->private->imask);
  64
  65                 }
  66                 cdev->private->imask >>= 1;
  67                 cdev->private->iretry = 5;
  68         }
  69         return ret;
  70 }
  71
  72 void
  73 ccw_device_sense_pgid_start(struct ccw_device *cdev)
  74 {
  75         int ret;
  76
  77         cdev->private->state = DEV_STATE_SENSE_PGID;
  78         cdev->private->imask = 0x80;
  79         cdev->private->iretry = 5;
  80         memset (&cdev->private->pgid, 0, sizeof (struct pgid));
  81         ret = __ccw_device_sense_pgid_start(cdev);
  82         if (ret && ret != -EBUSY)
  83                 ccw_device_sense_pgid_done(cdev, ret);
  84 }
  85
  86 /*
  87  * Called from interrupt context to check if a valid answer
  88  * to Sense Path Group ID was received.
  89  */
  90 static int
  91 __ccw_device_check_sense_pgid(struct ccw_device *cdev)
  92 {
  93         struct subchannel *sch;
  94         struct irb *irb;
  95
  96         sch = to_subchannel(cdev->dev.parent);
  97         irb = &cdev->private->irb;
  98         if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
  99                 return -ETIME;
 100         if (irb->esw.esw0.erw.cons &&
 101             (irb->ecw[0]&(SNS0_CMD_REJECT|SNS0_INTERVENTION_REQ))) {
 102                 /*
 103                  * If the device doesn't support the Sense Path Group ID
 104                  *  command further retries wouldn't help ...
 105                  */
 106                 return -EOPNOTSUPP;
 107         }
 108         if (irb->esw.esw0.erw.cons) {
 109                 CIO_MSG_EVENT(2, "SNID - device 0.%x.%04x, unit check, "
 110                               "lpum %02X, cnt %02d, sns : "
 111                               "%02X%02X%02X%02X %02X%02X%02X%02X ...\n",
 112                               cdev->private->ssid, cdev->private->devno,
 113                               irb->esw.esw0.sublog.lpum,
 114                               irb->esw.esw0.erw.scnt,
 115                               irb->ecw[0], irb->ecw[1],
 116                               irb->ecw[2], irb->ecw[3],
 117                               irb->ecw[4], irb->ecw[5],
 118                               irb->ecw[6], irb->ecw[7]);
 119                 return -EAGAIN;
 120         }
 121         if (irb->scsw.cc == 3) {
 122                 CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x,"
 123                               " lpm %02X, became 'not operational'\n",
 124                               cdev->private->devno, sch->schid.ssid,
 125                               sch->schid.sch_no, sch->orb.lpm);
 126                 return -EACCES;
 127         }
 128         if (cdev->private->pgid.inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
 129                 CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x "
 130                               "is reserved by someone else\n",
 131                               cdev->private->devno, sch->schid.ssid,
 132                               sch->schid.sch_no);
 133                 return -EUSERS;
 134         }
 135         return 0;
 136 }
 137
 138 /*
 139  * Got interrupt for Sense Path Group ID.
 140  */
 141 void
 142 ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
 143 {
 144         struct subchannel *sch;
 145         struct irb *irb;
 146         int ret;
 147
 148         irb = (struct irb *) __LC_IRB;
 149         /* Retry sense pgid for cc=1. */
 150         if (irb->scsw.stctl ==
 151             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 152                 if (irb->scsw.cc == 1) {
 153                         ret = __ccw_device_sense_pgid_start(cdev);
 154                         if (ret && ret != -EBUSY)
 155                                 ccw_device_sense_pgid_done(cdev, ret);
 156                 }
 157                 return;
 158         }
 159         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 160                 return;
 161         sch = to_subchannel(cdev->dev.parent);
 162         ret = __ccw_device_check_sense_pgid(cdev);
 163         memset(&cdev->private->irb, 0, sizeof(struct irb));
 164         switch (ret) {
 165         /* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
 166         case 0:                 /* Sense Path Group ID successful. */
 167                 if (cdev->private->pgid.inf.ps.state1 == SNID_STATE1_RESET)
 168                         memcpy(&cdev->private->pgid, &css[0]->global_pgid,
 169                                sizeof(struct pgid));
 170                 ccw_device_sense_pgid_done(cdev, 0);
 171                 break;
 172         case -EOPNOTSUPP:       /* Sense Path Group ID not supported */
 173                 ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
 174                 break;
 175         case -ETIME:            /* Sense path group id stopped by timeout. */
 176                 ccw_device_sense_pgid_done(cdev, -ETIME);
 177                 break;
 178         case -EACCES:           /* channel is not operational. */
 179                 sch->lpm &= ~cdev->private->imask;
 180                 cdev->private->imask >>= 1;
 181                 cdev->private->iretry = 5;
 182                 /* Fall through. */
 183         case -EAGAIN:           /* Try again. */
 184                 ret = __ccw_device_sense_pgid_start(cdev);
 185                 if (ret != 0 && ret != -EBUSY)
 186                         ccw_device_sense_pgid_done(cdev, -ENODEV);
 187                 break;
 188         case -EUSERS:           /* device is reserved for someone else. */
 189                 ccw_device_sense_pgid_done(cdev, -EUSERS);
 190                 break;
 191         }
 192 }
 193
 194 /*
 195  * Path Group ID helper function.
 196  */
 197 static int
 198 __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
 199 {
 200         struct subchannel *sch;
 201         struct ccw1 *ccw;
 202         int ret;
 203
 204         sch = to_subchannel(cdev->dev.parent);
 205
 206         /* Setup sense path group id channel program. */
 207         cdev->private->pgid.inf.fc = func;
 208         ccw = cdev->private->iccws;
 209         if (!cdev->private->flags.pgid_single) {
 210                 cdev->private->pgid.inf.fc |= SPID_FUNC_MULTI_PATH;
 211                 ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
 212                 ccw->cda = 0;
 213                 ccw->count = 0;
 214                 ccw->flags = CCW_FLAG_SLI | CCW_FLAG_CC;
 215                 ccw++;
 216         } else
 217                 cdev->private->pgid.inf.fc |= SPID_FUNC_SINGLE_PATH;
 218
 219         ccw->cmd_code = CCW_CMD_SET_PGID;
 220         ccw->cda = (__u32) __pa (&cdev->private->pgid);
 221         ccw->count = sizeof (struct pgid);
 222         ccw->flags = CCW_FLAG_SLI;
 223
 224         /* Reset device status. */
 225         memset(&cdev->private->irb, 0, sizeof(struct irb));
 226
 227         /* Try multiple times. */
 228         ret = -ENODEV;
 229         if (cdev->private->iretry > 0) {
 230                 cdev->private->iretry--;
 231                 ret = cio_start (sch, cdev->private->iccws,
 232                                  cdev->private->imask);
 233                 /* ret is 0, -EBUSY, -EACCES or -ENODEV */
 234                 if ((ret != -EACCES) && (ret != -ENODEV))
 235                         return ret;
 236         }
 237         /* PGID command failed on this path. Switch it off. */
 238         sch->lpm &= ~cdev->private->imask;
 239         sch->vpm &= ~cdev->private->imask;
 240         CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
 241                       "0.%x.%04x, lpm %02X, became 'not operational'\n",
 242                       cdev->private->devno, sch->schid.ssid,
 243                       sch->schid.sch_no, cdev->private->imask);
 244         return ret;
 245 }
 246
 247 /*
 248  * Called from interrupt context to check if a valid answer
 249  * to Set Path Group ID was received.
 250  */
 251 static int
 252 __ccw_device_check_pgid(struct ccw_device *cdev)
 253 {
 254         struct subchannel *sch;
 255         struct irb *irb;
 256
 257         sch = to_subchannel(cdev->dev.parent);
 258         irb = &cdev->private->irb;
 259         if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
 260                 return -ETIME;
 261         if (irb->esw.esw0.erw.cons) {
 262                 if (irb->ecw[0] & SNS0_CMD_REJECT)
 263                         return -EOPNOTSUPP;
 264                 /* Hmm, whatever happened, try again. */
 265                 CIO_MSG_EVENT(2, "SPID - device 0.%x.%04x, unit check, "
 266                               "cnt %02d, "
 267                               "sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
 268                               cdev->private->ssid,
 269                               cdev->private->devno, irb->esw.esw0.erw.scnt,
 270                               irb->ecw[0], irb->ecw[1],
 271                               irb->ecw[2], irb->ecw[3],
 272                               irb->ecw[4], irb->ecw[5],
 273                               irb->ecw[6], irb->ecw[7]);
 274                 return -EAGAIN;
 275         }
 276         if (irb->scsw.cc == 3) {
 277                 CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel 0.%x.%04x,"
 278                               " lpm %02X, became 'not operational'\n",
 279                               cdev->private->devno, sch->schid.ssid,
 280                               sch->schid.sch_no, cdev->private->imask);
 281                 return -EACCES;
 282         }
 283         return 0;
 284 }
 285
 286 static void
 287 __ccw_device_verify_start(struct ccw_device *cdev)
 288 {
 289         struct subchannel *sch;
 290         __u8 imask, func;
 291         int ret;
 292
 293         sch = to_subchannel(cdev->dev.parent);
 294         while (sch->vpm != sch->lpm) {
 295                 /* Find first unequal bit in vpm vs. lpm */
 296                 for (imask = 0x80; imask != 0; imask >>= 1)
 297                         if ((sch->vpm & imask) != (sch->lpm & imask))
 298                                 break;
 299                 cdev->private->imask = imask;
 300                 func = (sch->vpm & imask) ?
 301                         SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH;
 302                 ret = __ccw_device_do_pgid(cdev, func);
 303                 if (ret == 0 || ret == -EBUSY)
 304                         return;
 305                 cdev->private->iretry = 5;
 306         }
 307         ccw_device_verify_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
 308 }
 309
 310 /*
 311  * Got interrupt for Set Path Group ID.
 312  */
 313 void
 314 ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
 315 {
 316         struct subchannel *sch;
 317         struct irb *irb;
 318         int ret;
 319
 320         irb = (struct irb *) __LC_IRB;
 321         /* Retry set pgid for cc=1. */
 322         if (irb->scsw.stctl ==
 323             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 324                 if (irb->scsw.cc == 1)
 325                         __ccw_device_verify_start(cdev);
 326                 return;
 327         }
 328         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 329                 return;
 330         sch = to_subchannel(cdev->dev.parent);
 331         ret = __ccw_device_check_pgid(cdev);
 332         memset(&cdev->private->irb, 0, sizeof(struct irb));
 333         switch (ret) {
 334         /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
 335         case 0:
 336                 /* Establish or Resign Path Group done. Update vpm. */
 337                 if ((sch->lpm & cdev->private->imask) != 0)
 338                         sch->vpm |= cdev->private->imask;
 339                 else
 340                         sch->vpm &= ~cdev->private->imask;
 341                 cdev->private->iretry = 5;
 342                 __ccw_device_verify_start(cdev);
 343                 break;
 344         case -EOPNOTSUPP:
 345                 /*
 346                  * One of those strange devices which claim to be able
 347                  * to do multipathing but not for Set Path Group ID.
 348                  */
 349                 if (cdev->private->flags.pgid_single) {
 350                         ccw_device_verify_done(cdev, -EOPNOTSUPP);
 351                         break;
 352                 }
 353                 cdev->private->flags.pgid_single = 1;
 354                 /* fall through. */
 355         case -EAGAIN:           /* Try again. */
 356                 __ccw_device_verify_start(cdev);
 357                 break;
 358         case -ETIME:            /* Set path group id stopped by timeout. */
 359                 ccw_device_verify_done(cdev, -ETIME);
 360                 break;
 361         case -EACCES:           /* channel is not operational. */
 362                 sch->lpm &= ~cdev->private->imask;
 363                 sch->vpm &= ~cdev->private->imask;
 364                 cdev->private->iretry = 5;
 365                 __ccw_device_verify_start(cdev);
 366                 break;
 367         }
 368 }
 369
 370 void
 371 ccw_device_verify_start(struct ccw_device *cdev)
 372 {
 373         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 374
 375         cdev->private->flags.pgid_single = 0;
 376         cdev->private->iretry = 5;
 377         /*
 378          * Update sch->lpm with current values to catch paths becoming
 379          * available again.
 380          */
 381         if (stsch(sch->schid, &sch->schib)) {
 382                 ccw_device_verify_done(cdev, -ENODEV);
 383                 return;
 384         }
 385         sch->lpm = sch->schib.pmcw.pim &
 386                 sch->schib.pmcw.pam &
 387                 sch->schib.pmcw.pom &
 388                 sch->opm;
 389         __ccw_device_verify_start(cdev);
 390 }
 391
 392 static void
 393 __ccw_device_disband_start(struct ccw_device *cdev)
 394 {
 395         struct subchannel *sch;
 396         int ret;
 397
 398         sch = to_subchannel(cdev->dev.parent);
 399         while (cdev->private->imask != 0) {
 400                 if (sch->lpm & cdev->private->imask) {
 401                         ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
 402                         if (ret == 0)
 403                                 return;
 404                 }
 405                 cdev->private->iretry = 5;
 406                 cdev->private->imask >>= 1;
 407         }
 408         ccw_device_disband_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
 409 }
 410
 411 /*
 412  * Got interrupt for Unset Path Group ID.
 413  */
 414 void
 415 ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
 416 {
 417         struct subchannel *sch;
 418         struct irb *irb;
 419         int ret;
 420
 421         irb = (struct irb *) __LC_IRB;
 422         /* Retry set pgid for cc=1. */
 423         if (irb->scsw.stctl ==
 424             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 425                 if (irb->scsw.cc == 1)
 426                         __ccw_device_disband_start(cdev);
 427                 return;
 428         }
 429         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 430                 return;
 431         sch = to_subchannel(cdev->dev.parent);
 432         ret = __ccw_device_check_pgid(cdev);
 433         memset(&cdev->private->irb, 0, sizeof(struct irb));
 434         switch (ret) {
 435         /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
 436         case 0:                 /* disband successful. */
 437                 sch->vpm = 0;
 438                 ccw_device_disband_done(cdev, ret);
 439                 break;
 440         case -EOPNOTSUPP:
 441                 /*
 442                  * One of those strange devices which claim to be able
 443                  * to do multipathing but not for Unset Path Group ID.
 444                  */
 445                 cdev->private->flags.pgid_single = 1;
 446                 /* fall through. */
 447         case -EAGAIN:           /* Try again. */
 448                 __ccw_device_disband_start(cdev);
 449                 break;
 450         case -ETIME:            /* Set path group id stopped by timeout. */
 451                 ccw_device_disband_done(cdev, -ETIME);
 452                 break;
 453         case -EACCES:           /* channel is not operational. */
 454                 cdev->private->imask >>= 1;
 455                 cdev->private->iretry = 5;
 456                 __ccw_device_disband_start(cdev);
 457                 break;
 458         }
 459 }
 460
 461 void
 462 ccw_device_disband_start(struct ccw_device *cdev)
 463 {
 464         cdev->private->flags.pgid_single = 0;
 465         cdev->private->iretry = 5;
 466         cdev->private->imask = 0x80;
 467         __ccw_device_disband_start(cdev);
 468 }