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         switch (__ccw_device_check_sense_pgid(cdev)) {
 160         /* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
 161         case 0:                 /* Sense Path Group ID successful. */
 162                 if (cdev->private->pgid.inf.ps.state1 == SNID_STATE1_RESET)
 163                         memcpy(&cdev->private->pgid, &global_pgid,
 164                                sizeof(struct pgid));
 165                 ccw_device_sense_pgid_done(cdev, 0);
 166                 break;
 167         case -EOPNOTSUPP:       /* Sense Path Group ID not supported */
 168                 ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
 169                 break;
 170         case -ETIME:            /* Sense path group id stopped by timeout. */
 171                 ccw_device_sense_pgid_done(cdev, -ETIME);
 172                 break;
 173         case -EACCES:           /* channel is not operational. */
 174                 sch->lpm &= ~cdev->private->imask;
 175                 cdev->private->imask >>= 1;
 176                 cdev->private->iretry = 5;
 177                 /* Fall through. */
 178         case -EAGAIN:           /* Try again. */
 179                 ret = __ccw_device_sense_pgid_start(cdev);
 180                 if (ret != 0 && ret != -EBUSY)
 181                         ccw_device_sense_pgid_done(cdev, -ENODEV);
 182                 break;
 183         case -EUSERS:           /* device is reserved for someone else. */
 184                 ccw_device_sense_pgid_done(cdev, -EUSERS);
 185                 break;
 186         }
 187 }
 188
 189 /*
 190  * Path Group ID helper function.
 191  */
 192 static int
 193 __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
 194 {
 195         struct subchannel *sch;
 196         struct ccw1 *ccw;
 197         int ret;
 198
 199         sch = to_subchannel(cdev->dev.parent);
 200
 201         /* Setup sense path group id channel program. */
 202         cdev->private->pgid.inf.fc = func;
 203         ccw = cdev->private->iccws;
 204         if (!cdev->private->flags.pgid_single) {
 205                 cdev->private->pgid.inf.fc |= SPID_FUNC_MULTI_PATH;
 206                 ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
 207                 ccw->cda = 0;
 208                 ccw->count = 0;
 209                 ccw->flags = CCW_FLAG_SLI | CCW_FLAG_CC;
 210                 ccw++;
 211         } else
 212                 cdev->private->pgid.inf.fc |= SPID_FUNC_SINGLE_PATH;
 213
 214         ccw->cmd_code = CCW_CMD_SET_PGID;
 215         ccw->cda = (__u32) __pa (&cdev->private->pgid);
 216         ccw->count = sizeof (struct pgid);
 217         ccw->flags = CCW_FLAG_SLI;
 218
 219         /* Reset device status. */
 220         memset(&cdev->private->irb, 0, sizeof(struct irb));
 221
 222         /* Try multiple times. */
 223         ret = -ENODEV;
 224         if (cdev->private->iretry > 0) {
 225                 cdev->private->iretry--;
 226                 ret = cio_start (sch, cdev->private->iccws,
 227                                  cdev->private->imask);
 228                 /* ret is 0, -EBUSY, -EACCES or -ENODEV */
 229                 if ((ret != -EACCES) && (ret != -ENODEV))
 230                         return ret;
 231         }
 232         /* PGID command failed on this path. Switch it off. */
 233         sch->lpm &= ~cdev->private->imask;
 234         sch->vpm &= ~cdev->private->imask;
 235         CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
 236                       "%04x, lpm %02X, became 'not operational'\n",
 237                       cdev->private->devno, sch->irq, cdev->private->imask);
 238         return ret;
 239 }
 240
 241 /*
 242  * Called from interrupt context to check if a valid answer
 243  * to Set Path Group ID was received.
 244  */
 245 static int
 246 __ccw_device_check_pgid(struct ccw_device *cdev)
 247 {
 248         struct subchannel *sch;
 249         struct irb *irb;
 250
 251         sch = to_subchannel(cdev->dev.parent);
 252         irb = &cdev->private->irb;
 253         if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
 254                 return -ETIME;
 255         if (irb->esw.esw0.erw.cons) {
 256                 if (irb->ecw[0] & SNS0_CMD_REJECT)
 257                         return -EOPNOTSUPP;
 258                 /* Hmm, whatever happened, try again. */
 259                 CIO_MSG_EVENT(2, "SPID - device %04x, unit check, cnt %02d, "
 260                               "sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
 261                               cdev->private->devno, irb->esw.esw0.erw.scnt,
 262                               irb->ecw[0], irb->ecw[1],
 263                               irb->ecw[2], irb->ecw[3],
 264                               irb->ecw[4], irb->ecw[5],
 265                               irb->ecw[6], irb->ecw[7]);
 266                 return -EAGAIN;
 267         }
 268         if (irb->scsw.cc == 3) {
 269                 CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
 270                               "%04x, lpm %02X, became 'not operational'\n",
 271                               cdev->private->devno, sch->irq,
 272                               cdev->private->imask);
 273                 return -EACCES;
 274         }
 275         return 0;
 276 }
 277
 278 static void
 279 __ccw_device_verify_start(struct ccw_device *cdev)
 280 {
 281         struct subchannel *sch;
 282         __u8 imask, func;
 283         int ret;
 284
 285         sch = to_subchannel(cdev->dev.parent);
 286         while (sch->vpm != sch->lpm) {
 287                 /* Find first unequal bit in vpm vs. lpm */
 288                 for (imask = 0x80; imask != 0; imask >>= 1)
 289                         if ((sch->vpm & imask) != (sch->lpm & imask))
 290                                 break;
 291                 cdev->private->imask = imask;
 292                 func = (sch->vpm & imask) ?
 293                         SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH;
 294                 ret = __ccw_device_do_pgid(cdev, func);
 295                 if (ret == 0 || ret == -EBUSY)
 296                         return;
 297                 cdev->private->iretry = 5;
 298         }
 299         ccw_device_verify_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
 300 }
 301
 302 /*
 303  * Got interrupt for Set Path Group ID.
 304  */
 305 void
 306 ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
 307 {
 308         struct subchannel *sch;
 309         struct irb *irb;
 310
 311         irb = (struct irb *) __LC_IRB;
 312         /* Retry set pgid for cc=1. */
 313         if (irb->scsw.stctl ==
 314             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 315                 if (irb->scsw.cc == 1)
 316                         __ccw_device_verify_start(cdev);
 317                 return;
 318         }
 319         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 320                 return;
 321         sch = to_subchannel(cdev->dev.parent);
 322         switch (__ccw_device_check_pgid(cdev)) {
 323         /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
 324         case 0:
 325                 /* Establish or Resign Path Group done. Update vpm. */
 326                 if ((sch->lpm & cdev->private->imask) != 0)
 327                         sch->vpm |= cdev->private->imask;
 328                 else
 329                         sch->vpm &= ~cdev->private->imask;
 330                 cdev->private->iretry = 5;
 331                 __ccw_device_verify_start(cdev);
 332                 break;
 333         case -EOPNOTSUPP:
 334                 /*
 335                  * One of those strange devices which claim to be able
 336                  * to do multipathing but not for Set Path Group ID.
 337                  */
 338                 if (cdev->private->flags.pgid_single) {
 339                         ccw_device_verify_done(cdev, -EOPNOTSUPP);
 340                         break;
 341                 }
 342                 cdev->private->flags.pgid_single = 1;
 343                 /* fall through. */
 344         case -EAGAIN:           /* Try again. */
 345                 __ccw_device_verify_start(cdev);
 346                 break;
 347         case -ETIME:            /* Set path group id stopped by timeout. */
 348                 ccw_device_verify_done(cdev, -ETIME);
 349                 break;
 350         case -EACCES:           /* channel is not operational. */
 351                 sch->lpm &= ~cdev->private->imask;
 352                 sch->vpm &= ~cdev->private->imask;
 353                 cdev->private->iretry = 5;
 354                 __ccw_device_verify_start(cdev);
 355                 break;
 356         }
 357 }
 358
 359 void
 360 ccw_device_verify_start(struct ccw_device *cdev)
 361 {
 362         cdev->private->flags.pgid_single = 0;
 363         cdev->private->iretry = 5;
 364         __ccw_device_verify_start(cdev);
 365 }
 366
 367 static void
 368 __ccw_device_disband_start(struct ccw_device *cdev)
 369 {
 370         struct subchannel *sch;
 371         int ret;
 372
 373         sch = to_subchannel(cdev->dev.parent);
 374         while (cdev->private->imask != 0) {
 375                 if (sch->lpm & cdev->private->imask) {
 376                         ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
 377                         if (ret == 0)
 378                                 return;
 379                 }
 380                 cdev->private->iretry = 5;
 381                 cdev->private->imask >>= 1;
 382         }
 383         ccw_device_verify_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
 384 }
 385
 386 /*
 387  * Got interrupt for Unset Path Group ID.
 388  */
 389 void
 390 ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
 391 {
 392         struct subchannel *sch;
 393         struct irb *irb;
 394         int ret;
 395
 396         irb = (struct irb *) __LC_IRB;
 397         /* Retry set pgid for cc=1. */
 398         if (irb->scsw.stctl ==
 399             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 400                 if (irb->scsw.cc == 1)
 401                         __ccw_device_disband_start(cdev);
 402                 return;
 403         }
 404         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 405                 return;
 406         sch = to_subchannel(cdev->dev.parent);
 407         ret = __ccw_device_check_pgid(cdev);
 408         switch (ret) {
 409         /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
 410         case 0:                 /* disband successful. */
 411                 sch->vpm = 0;
 412                 ccw_device_disband_done(cdev, ret);
 413                 break;
 414         case -EOPNOTSUPP:
 415                 /*
 416                  * One of those strange devices which claim to be able
 417                  * to do multipathing but not for Unset Path Group ID.
 418                  */
 419                 cdev->private->flags.pgid_single = 1;
 420                 /* fall through. */
 421         case -EAGAIN:           /* Try again. */
 422                 __ccw_device_disband_start(cdev);
 423                 break;
 424         case -ETIME:            /* Set path group id stopped by timeout. */
 425                 ccw_device_disband_done(cdev, -ETIME);
 426                 break;
 427         case -EACCES:           /* channel is not operational. */
 428                 cdev->private->imask >>= 1;
 429                 cdev->private->iretry = 5;
 430                 __ccw_device_disband_start(cdev);
 431                 break;
 432         }
 433 }
 434
 435 void
 436 ccw_device_disband_start(struct ccw_device *cdev)
 437 {
 438         cdev->private->flags.pgid_single = 0;
 439         cdev->private->iretry = 5;
 440         cdev->private->imask = 0x80;
 441         __ccw_device_disband_start(cdev);
 442 }