drivers/s390/cio/device_pgid.c

   1 /*
   2  *  CCW device PGID and path verification I/O handling.
   3  *
   4  *    Copyright IBM Corp. 2002,2009
   5  *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
   6  *               Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  *               Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/string.h>
  12 #include <linux/types.h>
  13 #include <linux/errno.h>
  14 #include <linux/bitops.h>
  15 #include <asm/ccwdev.h>
  16 #include <asm/cio.h>
  17
  18 #include "cio.h"
  19 #include "cio_debug.h"
  20 #include "device.h"
  21 #include "io_sch.h"
  22
  23 #define PGID_RETRIES    256
  24 #define PGID_TIMEOUT    (10 * HZ)
  25
  26 /*
  27  * Process path verification data and report result.
  28  */
  29 static void verify_done(struct ccw_device *cdev, int rc)
  30 {
  31         struct subchannel *sch = to_subchannel(cdev->dev.parent);
  32         struct ccw_dev_id *id = &cdev->private->dev_id;
  33         int mpath = cdev->private->flags.mpath;
  34         int pgroup = cdev->private->flags.pgroup;
  35
  36         if (rc)
  37                 goto out;
  38         /* Ensure consistent multipathing state at device and channel. */
  39         if (sch->config.mp != mpath) {
  40                 sch->config.mp = mpath;
  41                 rc = cio_commit_config(sch);
  42         }
  43 out:
  44         CIO_MSG_EVENT(2, "vrfy: device 0.%x.%04x: rc=%d pgroup=%d mpath=%d "
  45                          "vpm=%02x\n", id->ssid, id->devno, rc, pgroup, mpath,
  46                          sch->vpm);
  47         ccw_device_verify_done(cdev, rc);
  48 }
  49
  50 /*
  51  * Create channel program to perform a NOOP.
  52  */
  53 static void nop_build_cp(struct ccw_device *cdev)
  54 {
  55         struct ccw_request *req = &cdev->private->req;
  56         struct ccw1 *cp = cdev->private->iccws;
  57
  58         cp->cmd_code    = CCW_CMD_NOOP;
  59         cp->cda         = 0;
  60         cp->count       = 0;
  61         cp->flags       = CCW_FLAG_SLI;
  62         req->cp         = cp;
  63 }
  64
  65 /*
  66  * Perform NOOP on a single path.
  67  */
  68 static void nop_do(struct ccw_device *cdev)
  69 {
  70         struct subchannel *sch = to_subchannel(cdev->dev.parent);
  71         struct ccw_request *req = &cdev->private->req;
  72
  73         /* Adjust lpm. */
  74         req->lpm = lpm_adjust(req->lpm, sch->schib.pmcw.pam & sch->opm);
  75         if (!req->lpm)
  76                 goto out_nopath;
  77         nop_build_cp(cdev);
  78         ccw_request_start(cdev);
  79         return;
  80
  81 out_nopath:
  82         verify_done(cdev, sch->vpm ? 0 : -EACCES);
  83 }
  84
  85 /*
  86  * Adjust NOOP I/O status.
  87  */
  88 static enum io_status nop_filter(struct ccw_device *cdev, void *data,
  89                                  struct irb *irb, enum io_status status)
  90 {
  91         /* Only subchannel status might indicate a path error. */
  92         if (status == IO_STATUS_ERROR && irb->scsw.cmd.cstat == 0)
  93                 return IO_DONE;
  94         return status;
  95 }
  96
  97 /*
  98  * Process NOOP request result for a single path.
  99  */
 100 static void nop_callback(struct ccw_device *cdev, void *data, int rc)
 101 {
 102         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 103         struct ccw_request *req = &cdev->private->req;
 104
 105         if (rc == 0)
 106                 sch->vpm |= req->lpm;
 107         else if (rc != -EACCES)
 108                 goto err;
 109         req->lpm >>= 1;
 110         nop_do(cdev);
 111         return;
 112
 113 err:
 114         verify_done(cdev, rc);
 115 }
 116
 117 /*
 118  * Create channel program to perform SET PGID on a single path.
 119  */
 120 static void spid_build_cp(struct ccw_device *cdev, u8 fn)
 121 {
 122         struct ccw_request *req = &cdev->private->req;
 123         struct ccw1 *cp = cdev->private->iccws;
 124         int i = 8 - ffs(req->lpm);
 125         struct pgid *pgid = &cdev->private->pgid[i];
 126
 127         pgid->inf.fc    = fn;
 128         cp->cmd_code    = CCW_CMD_SET_PGID;
 129         cp->cda         = (u32) (addr_t) pgid;
 130         cp->count       = sizeof(*pgid);
 131         cp->flags       = CCW_FLAG_SLI;
 132         req->cp         = cp;
 133 }
 134
 135 /*
 136  * Perform establish/resign SET PGID on a single path.
 137  */
 138 static void spid_do(struct ccw_device *cdev)
 139 {
 140         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 141         struct ccw_request *req = &cdev->private->req;
 142         u8 fn;
 143
 144         /* Use next available path that is not already in correct state. */
 145         req->lpm = lpm_adjust(req->lpm, cdev->private->pgid_todo_mask);
 146         if (!req->lpm)
 147                 goto out_nopath;
 148         /* Channel program setup. */
 149         if (req->lpm & sch->opm)
 150                 fn = SPID_FUNC_ESTABLISH;
 151         else
 152                 fn = SPID_FUNC_RESIGN;
 153         if (cdev->private->flags.mpath)
 154                 fn |= SPID_FUNC_MULTI_PATH;
 155         spid_build_cp(cdev, fn);
 156         ccw_request_start(cdev);
 157         return;
 158
 159 out_nopath:
 160         verify_done(cdev, sch->vpm ? 0 : -EACCES);
 161 }
 162
 163 static void verify_start(struct ccw_device *cdev);
 164
 165 /*
 166  * Process SET PGID request result for a single path.
 167  */
 168 static void spid_callback(struct ccw_device *cdev, void *data, int rc)
 169 {
 170         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 171         struct ccw_request *req = &cdev->private->req;
 172
 173         switch (rc) {
 174         case 0:
 175                 sch->vpm |= req->lpm & sch->opm;
 176                 break;
 177         case -EACCES:
 178                 break;
 179         case -EOPNOTSUPP:
 180                 if (cdev->private->flags.mpath) {
 181                         /* Try without multipathing. */
 182                         cdev->private->flags.mpath = 0;
 183                         goto out_restart;
 184                 }
 185                 /* Try without pathgrouping. */
 186                 cdev->private->flags.pgroup = 0;
 187                 goto out_restart;
 188         default:
 189                 goto err;
 190         }
 191         req->lpm >>= 1;
 192         spid_do(cdev);
 193         return;
 194
 195 out_restart:
 196         verify_start(cdev);
 197         return;
 198 err:
 199         verify_done(cdev, rc);
 200 }
 201
 202 static void spid_start(struct ccw_device *cdev)
 203 {
 204         struct ccw_request *req = &cdev->private->req;
 205
 206         /* Initialize request data. */
 207         memset(req, 0, sizeof(*req));
 208         req->timeout    = PGID_TIMEOUT;
 209         req->maxretries = PGID_RETRIES;
 210         req->lpm        = 0x80;
 211         req->singlepath = 1;
 212         req->callback   = spid_callback;
 213         spid_do(cdev);
 214 }
 215
 216 static int pgid_is_reset(struct pgid *p)
 217 {
 218         char *c;
 219
 220         for (c = (char *)p + 1; c < (char *)(p + 1); c++) {
 221                 if (*c != 0)
 222                         return 0;
 223         }
 224         return 1;
 225 }
 226
 227 static int pgid_cmp(struct pgid *p1, struct pgid *p2)
 228 {
 229         return memcmp((char *) p1 + 1, (char *) p2 + 1,
 230                       sizeof(struct pgid) - 1);
 231 }
 232
 233 /*
 234  * Determine pathgroup state from PGID data.
 235  */
 236 static void pgid_analyze(struct ccw_device *cdev, struct pgid **p,
 237                          int *mismatch, u8 *reserved, u8 *reset)
 238 {
 239         struct pgid *pgid = &cdev->private->pgid[0];
 240         struct pgid *first = NULL;
 241         int lpm;
 242         int i;
 243
 244         *mismatch = 0;
 245         *reserved = 0;
 246         *reset = 0;
 247         for (i = 0, lpm = 0x80; i < 8; i++, pgid++, lpm >>= 1) {
 248                 if ((cdev->private->pgid_valid_mask & lpm) == 0)
 249                         continue;
 250                 if (pgid->inf.ps.state2 == SNID_STATE2_RESVD_ELSE)
 251                         *reserved |= lpm;
 252                 if (pgid_is_reset(pgid)) {
 253                         *reset |= lpm;
 254                         continue;
 255                 }
 256                 if (!first) {
 257                         first = pgid;
 258                         continue;
 259                 }
 260                 if (pgid_cmp(pgid, first) != 0)
 261                         *mismatch = 1;
 262         }
 263         if (!first)
 264                 first = &channel_subsystems[0]->global_pgid;
 265         *p = first;
 266 }
 267
 268 static u8 pgid_to_donepm(struct ccw_device *cdev)
 269 {
 270         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 271         struct pgid *pgid;
 272         int i;
 273         int lpm;
 274         u8 donepm = 0;
 275
 276         /* Set bits for paths which are already in the target state. */
 277         for (i = 0; i < 8; i++) {
 278                 lpm = 0x80 >> i;
 279                 if ((cdev->private->pgid_valid_mask & lpm) == 0)
 280                         continue;
 281                 pgid = &cdev->private->pgid[i];
 282                 if (sch->opm & lpm) {
 283                         if (pgid->inf.ps.state1 != SNID_STATE1_GROUPED)
 284                                 continue;
 285                 } else {
 286                         if (pgid->inf.ps.state1 != SNID_STATE1_UNGROUPED)
 287                                 continue;
 288                 }
 289                 if (cdev->private->flags.mpath) {
 290                         if (pgid->inf.ps.state3 != SNID_STATE3_MULTI_PATH)
 291                                 continue;
 292                 } else {
 293                         if (pgid->inf.ps.state3 != SNID_STATE3_SINGLE_PATH)
 294                                 continue;
 295                 }
 296                 donepm |= lpm;
 297         }
 298
 299         return donepm;
 300 }
 301
 302 static void pgid_fill(struct ccw_device *cdev, struct pgid *pgid)
 303 {
 304         int i;
 305
 306         for (i = 0; i < 8; i++)
 307                 memcpy(&cdev->private->pgid[i], pgid, sizeof(struct pgid));
 308 }
 309
 310 /*
 311  * Process SENSE PGID data and report result.
 312  */
 313 static void snid_done(struct ccw_device *cdev, int rc)
 314 {
 315         struct ccw_dev_id *id = &cdev->private->dev_id;
 316         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 317         struct pgid *pgid;
 318         int mismatch = 0;
 319         u8 reserved = 0;
 320         u8 reset = 0;
 321         u8 donepm;
 322
 323         if (rc)
 324                 goto out;
 325         pgid_analyze(cdev, &pgid, &mismatch, &reserved, &reset);
 326         if (reserved == cdev->private->pgid_valid_mask)
 327                 rc = -EUSERS;
 328         else if (mismatch)
 329                 rc = -EOPNOTSUPP;
 330         else {
 331                 donepm = pgid_to_donepm(cdev);
 332                 sch->vpm = donepm & sch->opm;
 333                 cdev->private->pgid_todo_mask &= ~donepm;
 334                 cdev->private->pgid_reset_mask |= reset;
 335                 pgid_fill(cdev, pgid);
 336         }
 337 out:
 338         CIO_MSG_EVENT(2, "snid: device 0.%x.%04x: rc=%d pvm=%02x vpm=%02x "
 339                       "todo=%02x mism=%d rsvd=%02x reset=%02x\n", id->ssid,
 340                       id->devno, rc, cdev->private->pgid_valid_mask, sch->vpm,
 341                       cdev->private->pgid_todo_mask, mismatch, reserved, reset);
 342         switch (rc) {
 343         case 0:
 344                 /* Anything left to do? */
 345                 if (cdev->private->pgid_todo_mask == 0) {
 346                         verify_done(cdev, sch->vpm == 0 ? -EACCES : 0);
 347                         return;
 348                 }
 349                 /* Perform path-grouping. */
 350                 spid_start(cdev);
 351                 break;
 352         case -EOPNOTSUPP:
 353                 /* Path-grouping not supported. */
 354                 cdev->private->flags.pgroup = 0;
 355                 cdev->private->flags.mpath = 0;
 356                 verify_start(cdev);
 357                 break;
 358         default:
 359                 verify_done(cdev, rc);
 360         }
 361 }
 362
 363 /*
 364  * Create channel program to perform a SENSE PGID on a single path.
 365  */
 366 static void snid_build_cp(struct ccw_device *cdev)
 367 {
 368         struct ccw_request *req = &cdev->private->req;
 369         struct ccw1 *cp = cdev->private->iccws;
 370         int i = 8 - ffs(req->lpm);
 371
 372         /* Channel program setup. */
 373         cp->cmd_code    = CCW_CMD_SENSE_PGID;
 374         cp->cda         = (u32) (addr_t) &cdev->private->pgid[i];
 375         cp->count       = sizeof(struct pgid);
 376         cp->flags       = CCW_FLAG_SLI;
 377         req->cp         = cp;
 378 }
 379
 380 /*
 381  * Perform SENSE PGID on a single path.
 382  */
 383 static void snid_do(struct ccw_device *cdev)
 384 {
 385         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 386         struct ccw_request *req = &cdev->private->req;
 387
 388         /* Adjust lpm if paths are not set in pam. */
 389         req->lpm = lpm_adjust(req->lpm, sch->schib.pmcw.pam);
 390         if (!req->lpm)
 391                 goto out_nopath;
 392         snid_build_cp(cdev);
 393         ccw_request_start(cdev);
 394         return;
 395
 396 out_nopath:
 397         snid_done(cdev, cdev->private->pgid_valid_mask ? 0 : -EACCES);
 398 }
 399
 400 /*
 401  * Process SENSE PGID request result for single path.
 402  */
 403 static void snid_callback(struct ccw_device *cdev, void *data, int rc)
 404 {
 405         struct ccw_request *req = &cdev->private->req;
 406
 407         if (rc == 0)
 408                 cdev->private->pgid_valid_mask |= req->lpm;
 409         else if (rc != -EACCES)
 410                 goto err;
 411         req->lpm >>= 1;
 412         snid_do(cdev);
 413         return;
 414
 415 err:
 416         snid_done(cdev, rc);
 417 }
 418
 419 /*
 420  * Perform path verification.
 421  */
 422 static void verify_start(struct ccw_device *cdev)
 423 {
 424         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 425         struct ccw_request *req = &cdev->private->req;
 426         struct ccw_dev_id *devid = &cdev->private->dev_id;
 427
 428         sch->vpm = 0;
 429         sch->lpm = sch->schib.pmcw.pam;
 430         /* Initialize request data. */
 431         memset(req, 0, sizeof(*req));
 432         req->timeout    = PGID_TIMEOUT;
 433         req->maxretries = PGID_RETRIES;
 434         req->lpm        = 0x80;
 435         req->singlepath = 1;
 436         if (cdev->private->flags.pgroup) {
 437                 CIO_TRACE_EVENT(4, "snid");
 438                 CIO_HEX_EVENT(4, devid, sizeof(*devid));
 439                 req->callback   = snid_callback;
 440                 snid_do(cdev);
 441         } else {
 442                 CIO_TRACE_EVENT(4, "nop");
 443                 CIO_HEX_EVENT(4, devid, sizeof(*devid));
 444                 req->filter     = nop_filter;
 445                 req->callback   = nop_callback;
 446                 nop_do(cdev);
 447         }
 448 }
 449
 450 /**
 451  * ccw_device_verify_start - perform path verification
 452  * @cdev: ccw device
 453  *
 454  * Perform an I/O on each available channel path to @cdev to determine which
 455  * paths are operational. The resulting path mask is stored in sch->vpm.
 456  * If device options specify pathgrouping, establish a pathgroup for the
 457  * operational paths. When finished, call ccw_device_verify_done with a
 458  * return code specifying the result.
 459  */
 460 void ccw_device_verify_start(struct ccw_device *cdev)
 461 {
 462         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 463
 464         CIO_TRACE_EVENT(4, "vrfy");
 465         CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
 466         /* Initialize PGID data. */
 467         memset(cdev->private->pgid, 0, sizeof(cdev->private->pgid));
 468         cdev->private->pgid_valid_mask = 0;
 469         cdev->private->pgid_todo_mask = sch->schib.pmcw.pam;
 470         /*
 471          * Initialize pathgroup and multipath state with target values.
 472          * They may change in the course of path verification.
 473          */
 474         cdev->private->flags.pgroup = cdev->private->options.pgroup;
 475         cdev->private->flags.mpath = cdev->private->options.mpath;
 476         cdev->private->flags.doverify = 0;
 477         verify_start(cdev);
 478 }
 479
 480 /*
 481  * Process disband SET PGID request result.
 482  */
 483 static void disband_callback(struct ccw_device *cdev, void *data, int rc)
 484 {
 485         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 486         struct ccw_dev_id *id = &cdev->private->dev_id;
 487
 488         if (rc)
 489                 goto out;
 490         /* Ensure consistent multipathing state at device and channel. */
 491         cdev->private->flags.mpath = 0;
 492         if (sch->config.mp) {
 493                 sch->config.mp = 0;
 494                 rc = cio_commit_config(sch);
 495         }
 496 out:
 497         CIO_MSG_EVENT(0, "disb: device 0.%x.%04x: rc=%d\n", id->ssid, id->devno,
 498                       rc);
 499         ccw_device_disband_done(cdev, rc);
 500 }
 501
 502 /**
 503  * ccw_device_disband_start - disband pathgroup
 504  * @cdev: ccw device
 505  *
 506  * Execute a SET PGID channel program on @cdev to disband a previously
 507  * established pathgroup. When finished, call ccw_device_disband_done with
 508  * a return code specifying the result.
 509  */
 510 void ccw_device_disband_start(struct ccw_device *cdev)
 511 {
 512         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 513         struct ccw_request *req = &cdev->private->req;
 514         u8 fn;
 515
 516         CIO_TRACE_EVENT(4, "disb");
 517         CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
 518         /* Request setup. */
 519         memset(req, 0, sizeof(*req));
 520         req->timeout    = PGID_TIMEOUT;
 521         req->maxretries = PGID_RETRIES;
 522         req->lpm        = sch->schib.pmcw.pam & sch->opm;
 523         req->singlepath = 1;
 524         req->callback   = disband_callback;
 525         fn = SPID_FUNC_DISBAND;
 526         if (cdev->private->flags.mpath)
 527                 fn |= SPID_FUNC_MULTI_PATH;
 528         spid_build_cp(cdev, fn);
 529         ccw_request_start(cdev);
 530 }
 531
 532 static void stlck_build_cp(struct ccw_device *cdev, void *buf1, void *buf2)
 533 {
 534         struct ccw_request *req = &cdev->private->req;
 535         struct ccw1 *cp = cdev->private->iccws;
 536
 537         cp[0].cmd_code = CCW_CMD_STLCK;
 538         cp[0].cda = (u32) (addr_t) buf1;
 539         cp[0].count = 32;
 540         cp[0].flags = CCW_FLAG_CC;
 541         cp[1].cmd_code = CCW_CMD_RELEASE;
 542         cp[1].cda = (u32) (addr_t) buf2;
 543         cp[1].count = 32;
 544         cp[1].flags = 0;
 545         req->cp = cp;
 546 }
 547
 548 static void stlck_callback(struct ccw_device *cdev, void *data, int rc)
 549 {
 550         ccw_device_stlck_done(cdev, data, rc);
 551 }
 552
 553 /**
 554  * ccw_device_stlck_start - perform unconditional release
 555  * @cdev: ccw device
 556  * @data: data pointer to be passed to ccw_device_stlck_done
 557  * @buf1: data pointer used in channel program
 558  * @buf2: data pointer used in channel program
 559  *
 560  * Execute a channel program on @cdev to release an existing PGID reservation.
 561  * When finished, call ccw_device_stlck_done with a return code specifying the
 562  * result.
 563  */
 564 void ccw_device_stlck_start(struct ccw_device *cdev, void *data, void *buf1,
 565                             void *buf2)
 566 {
 567         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 568         struct ccw_request *req = &cdev->private->req;
 569
 570         CIO_TRACE_EVENT(4, "stlck");
 571         CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
 572         /* Request setup. */
 573         memset(req, 0, sizeof(*req));
 574         req->timeout    = PGID_TIMEOUT;
 575         req->maxretries = PGID_RETRIES;
 576         req->lpm        = sch->schib.pmcw.pam & sch->opm;
 577         req->data       = data;
 578         req->callback   = stlck_callback;
 579         stlck_build_cp(cdev, buf1, buf2);
 580         ccw_request_start(cdev);
 581 }
 582