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