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         /*
 147          * Unsolicited interrupts may pertain to an earlier status pending or
 148          * busy condition on the subchannel. Retry sense pgid.
 149          */
 150         if (irb->scsw.stctl ==
 151             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 152                 ret = __ccw_device_sense_pgid_start(cdev);
 153                 if (ret && ret != -EBUSY)
 154                         ccw_device_sense_pgid_done(cdev, ret);
 155                 return;
 156         }
 157         if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
 158                 return;
 159         sch = to_subchannel(cdev->dev.parent);
 160         switch (__ccw_device_check_sense_pgid(cdev)) {
 161         /* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
 162         case 0:                 /* Sense Path Group ID successful. */
 163                 if (cdev->private->pgid.inf.ps.state1 == SNID_STATE1_RESET)
 164                         memcpy(&cdev->private->pgid, &global_pgid,
 165                                sizeof(struct pgid));
 166                 ccw_device_sense_pgid_done(cdev, 0);
 167                 break;
 168         case -EOPNOTSUPP:       /* Sense Path Group ID not supported */
 169                 ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
 170                 break;
 171         case -ETIME:            /* Sense path group id stopped by timeout. */
 172                 ccw_device_sense_pgid_done(cdev, -ETIME);
 173                 break;
 174         case -EACCES:           /* channel is not operational. */
 175                 sch->lpm &= ~cdev->private->imask;
 176                 cdev->private->imask >>= 1;
 177                 cdev->private->iretry = 5;
 178                 /* Fall through. */
 179         case -EAGAIN:           /* Try again. */
 180                 ret = __ccw_device_sense_pgid_start(cdev);
 181                 if (ret != 0 && ret != -EBUSY)
 182                         ccw_device_sense_pgid_done(cdev, -ENODEV);
 183                 break;
 184         case -EUSERS:           /* device is reserved for someone else. */
 185                 ccw_device_sense_pgid_done(cdev, -EUSERS);
 186                 break;
 187         }
 188 }
 189
 190 /*
 191  * Path Group ID helper function.
 192  */
 193 static int
 194 __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
 195 {
 196         struct subchannel *sch;
 197         struct ccw1 *ccw;
 198         int ret;
 199
 200         sch = to_subchannel(cdev->dev.parent);
 201
 202         /* Setup sense path group id channel program. */
 203         cdev->private->pgid.inf.fc = func;
 204         ccw = cdev->private->iccws;
 205         if (!cdev->private->flags.pgid_single) {
 206                 cdev->private->pgid.inf.fc |= SPID_FUNC_MULTI_PATH;
 207                 ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
 208                 ccw->cda = 0;
 209                 ccw->count = 0;
 210                 ccw->flags = CCW_FLAG_SLI | CCW_FLAG_CC;
 211                 ccw++;
 212         } else
 213                 cdev->private->pgid.inf.fc |= SPID_FUNC_SINGLE_PATH;
 214
 215         ccw->cmd_code = CCW_CMD_SET_PGID;
 216         ccw->cda = (__u32) __pa (&cdev->private->pgid);
 217         ccw->count = sizeof (struct pgid);
 218         ccw->flags = CCW_FLAG_SLI;
 219
 220         /* Reset device status. */
 221         memset(&cdev->private->irb, 0, sizeof(struct irb));
 222
 223         /* Try multiple times. */
 224         ret = -ENODEV;
 225         if (cdev->private->iretry > 0) {
 226                 cdev->private->iretry--;
 227                 ret = cio_start (sch, cdev->private->iccws,
 228                                  cdev->private->imask);
 229                 /* ret is 0, -EBUSY, -EACCES or -ENODEV */
 230                 if ((ret != -EACCES) && (ret != -ENODEV))
 231                         return ret;
 232         }
 233         /* PGID command failed on this path. Switch it off. */
 234         sch->lpm &= ~cdev->private->imask;
 235         sch->vpm &= ~cdev->private->imask;
 236         CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
 237                       "%04x, lpm %02X, became 'not operational'\n",
 238                       cdev->private->devno, sch->irq, cdev->private->imask);
 239         return ret;
 240 }
 241
 242 /*
 243  * Called from interrupt context to check if a valid answer
 244  * to Set Path Group ID was received.
 245  */
 246 static int
 247 __ccw_device_check_pgid(struct ccw_device *cdev)
 248 {
 249         struct subchannel *sch;
 250         struct irb *irb;
 251
 252         sch = to_subchannel(cdev->dev.parent);
 253         irb = &cdev->private->irb;
 254         if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
 255                 return -ETIME;
 256         if (irb->esw.esw0.erw.cons) {
 257                 if (irb->ecw[0] & SNS0_CMD_REJECT)
 258                         return -EOPNOTSUPP;
 259                 /* Hmm, whatever happened, try again. */
 260                 CIO_MSG_EVENT(2, "SPID - device %04x, unit check, cnt %02d, "
 261                               "sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
 262                               cdev->private->devno, irb->esw.esw0.erw.scnt,
 263                               irb->ecw[0], irb->ecw[1],
 264                               irb->ecw[2], irb->ecw[3],
 265                               irb->ecw[4], irb->ecw[5],
 266                               irb->ecw[6], irb->ecw[7]);
 267                 return -EAGAIN;
 268         }
 269         if (irb->scsw.cc == 3) {
 270                 CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
 271                               "%04x, lpm %02X, became 'not operational'\n",
 272                               cdev->private->devno, sch->irq,
 273                               cdev->private->imask);
 274                 return -EACCES;
 275         }
 276         return 0;
 277 }
 278
 279 static void
 280 __ccw_device_verify_start(struct ccw_device *cdev)
 281 {
 282         struct subchannel *sch;
 283         __u8 imask, func;
 284         int ret;
 285
 286         sch = to_subchannel(cdev->dev.parent);
 287         while (sch->vpm != sch->lpm) {
 288                 /* Find first unequal bit in vpm vs. lpm */
 289                 for (imask = 0x80; imask != 0; imask >>= 1)
 290                         if ((sch->vpm & imask) != (sch->lpm & imask))
 291                                 break;
 292                 cdev->private->imask = imask;
 293                 func = (sch->vpm & imask) ?
 294                         SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH;
 295                 ret = __ccw_device_do_pgid(cdev, func);
 296                 if (ret == 0 || ret == -EBUSY)
 297                         return;
 298                 cdev->private->iretry = 5;
 299         }
 300         ccw_device_verify_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
 301 }
 302
 303 /*
 304  * Got interrupt for Set Path Group ID.
 305  */
 306 void
 307 ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
 308 {
 309         struct subchannel *sch;
 310         struct irb *irb;
 311
 312         irb = (struct irb *) __LC_IRB;
 313         /*
 314          * Unsolicited interrupts may pertain to an earlier status pending or
 315          * busy condition on the subchannel. Restart path verification.
 316          */
 317         if (irb->scsw.stctl ==
 318             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 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         switch (__ccw_device_check_pgid(cdev)) {
 326         /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
 327         case 0:
 328                 /* Establish or Resign Path Group done. Update vpm. */
 329                 if ((sch->lpm & cdev->private->imask) != 0)
 330                         sch->vpm |= cdev->private->imask;
 331                 else
 332                         sch->vpm &= ~cdev->private->imask;
 333                 cdev->private->iretry = 5;
 334                 __ccw_device_verify_start(cdev);
 335                 break;
 336         case -EOPNOTSUPP:
 337                 /*
 338                  * One of those strange devices which claim to be able
 339                  * to do multipathing but not for Set Path Group ID.
 340                  */
 341                 if (cdev->private->flags.pgid_single) {
 342                         ccw_device_verify_done(cdev, -EOPNOTSUPP);
 343                         break;
 344                 }
 345                 cdev->private->flags.pgid_single = 1;
 346                 /* fall through. */
 347         case -EAGAIN:           /* Try again. */
 348                 __ccw_device_verify_start(cdev);
 349                 break;
 350         case -ETIME:            /* Set path group id stopped by timeout. */
 351                 ccw_device_verify_done(cdev, -ETIME);
 352                 break;
 353         case -EACCES:           /* channel is not operational. */
 354                 sch->lpm &= ~cdev->private->imask;
 355                 sch->vpm &= ~cdev->private->imask;
 356                 cdev->private->iretry = 5;
 357                 __ccw_device_verify_start(cdev);
 358                 break;
 359         }
 360 }
 361
 362 void
 363 ccw_device_verify_start(struct ccw_device *cdev)
 364 {
 365         cdev->private->flags.pgid_single = 0;
 366         cdev->private->iretry = 5;
 367         __ccw_device_verify_start(cdev);
 368 }
 369
 370 static void
 371 __ccw_device_disband_start(struct ccw_device *cdev)
 372 {
 373         struct subchannel *sch;
 374         int ret;
 375
 376         sch = to_subchannel(cdev->dev.parent);
 377         while (cdev->private->imask != 0) {
 378                 if (sch->lpm & cdev->private->imask) {
 379                         ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
 380                         if (ret == 0)
 381                                 return;
 382                 }
 383                 cdev->private->iretry = 5;
 384                 cdev->private->imask >>= 1;
 385         }
 386         ccw_device_verify_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
 387 }
 388
 389 /*
 390  * Got interrupt for Unset Path Group ID.
 391  */
 392 void
 393 ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
 394 {
 395         struct subchannel *sch;
 396         struct irb *irb;
 397         int ret;
 398
 399         irb = (struct irb *) __LC_IRB;
 400         /* Ignore unsolicited interrupts. */
 401         if (irb->scsw.stctl ==
 402                         (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS))
 403                 return;
 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 }