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, sch->schib.pmcw.pam & ~sch->vpm); 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->callback = spid_callback; 212 spid_do(cdev); 213 } 214 215 static int pgid_cmp(struct pgid *p1, struct pgid *p2) 216 { 217 return memcmp((char *) p1 + 1, (char *) p2 + 1, 218 sizeof(struct pgid) - 1); 219 } 220 221 /* 222 * Determine pathgroup state from PGID data. 223 */ 224 static void pgid_analyze(struct ccw_device *cdev, struct pgid **p, 225 int *mismatch, int *reserved, int *reset) 226 { 227 struct pgid *pgid = &cdev->private->pgid[0]; 228 struct pgid *first = NULL; 229 int lpm; 230 int i; 231 232 *mismatch = 0; 233 *reserved = 0; 234 *reset = 0; 235 for (i = 0, lpm = 0x80; i < 8; i++, pgid++, lpm >>= 1) { 236 if ((cdev->private->pgid_valid_mask & lpm) == 0) 237 continue; 238 if (pgid->inf.ps.state2 == SNID_STATE2_RESVD_ELSE) 239 *reserved = 1; 240 if (pgid->inf.ps.state1 == SNID_STATE1_RESET) { 241 /* A PGID was reset. */ 242 *reset = 1; 243 continue; 244 } 245 if (!first) { 246 first = pgid; 247 continue; 248 } 249 if (pgid_cmp(pgid, first) != 0) 250 *mismatch = 1; 251 } 252 if (!first) 253 first = &channel_subsystems[0]->global_pgid; 254 *p = first; 255 } 256 257 static u8 pgid_to_vpm(struct ccw_device *cdev) 258 { 259 struct subchannel *sch = to_subchannel(cdev->dev.parent); 260 struct pgid *pgid; 261 int i; 262 int lpm; 263 u8 vpm = 0; 264 265 /* Set VPM bits for paths which are already in the target state. */ 266 for (i = 0; i < 8; i++) { 267 lpm = 0x80 >> i; 268 if ((cdev->private->pgid_valid_mask & lpm) == 0) 269 continue; 270 pgid = &cdev->private->pgid[i]; 271 if (sch->opm & lpm) { 272 if (pgid->inf.ps.state1 != SNID_STATE1_GROUPED) 273 continue; 274 } else { 275 if (pgid->inf.ps.state1 != SNID_STATE1_UNGROUPED) 276 continue; 277 } 278 if (cdev->private->flags.mpath) { 279 if (pgid->inf.ps.state3 != SNID_STATE3_MULTI_PATH) 280 continue; 281 } else { 282 if (pgid->inf.ps.state3 != SNID_STATE3_SINGLE_PATH) 283 continue; 284 } 285 vpm |= lpm; 286 } 287 288 return vpm; 289 } 290 291 static void pgid_fill(struct ccw_device *cdev, struct pgid *pgid) 292 { 293 int i; 294 295 for (i = 0; i < 8; i++) 296 memcpy(&cdev->private->pgid[i], pgid, sizeof(struct pgid)); 297 } 298 299 /* 300 * Process SENSE PGID data and report result. 301 */ 302 static void snid_done(struct ccw_device *cdev, int rc) 303 { 304 struct ccw_dev_id *id = &cdev->private->dev_id; 305 struct subchannel *sch = to_subchannel(cdev->dev.parent); 306 struct pgid *pgid; 307 int mismatch = 0; 308 int reserved = 0; 309 int reset = 0; 310 311 if (rc) 312 goto out; 313 pgid_analyze(cdev, &pgid, &mismatch, &reserved, &reset); 314 if (reserved) 315 rc = -EUSERS; 316 else if (mismatch) 317 rc = -EOPNOTSUPP; 318 else { 319 sch->vpm = pgid_to_vpm(cdev); 320 pgid_fill(cdev, pgid); 321 } 322 out: 323 CIO_MSG_EVENT(2, "snid: device 0.%x.%04x: rc=%d pvm=%02x vpm=%02x " 324 "mism=%d rsvd=%d reset=%d\n", id->ssid, id->devno, rc, 325 cdev->private->pgid_valid_mask, sch->vpm, mismatch, 326 reserved, reset); 327 switch (rc) { 328 case 0: 329 /* Anything left to do? */ 330 if (sch->vpm == sch->schib.pmcw.pam) { 331 verify_done(cdev, sch->vpm == 0 ? -EACCES : 0); 332 return; 333 } 334 /* Perform path-grouping. */ 335 spid_start(cdev); 336 break; 337 case -EOPNOTSUPP: 338 /* Path-grouping not supported. */ 339 cdev->private->flags.pgroup = 0; 340 cdev->private->flags.mpath = 0; 341 verify_start(cdev); 342 break; 343 default: 344 verify_done(cdev, rc); 345 } 346 } 347 348 /* 349 * Create channel program to perform a SENSE PGID on a single path. 350 */ 351 static void snid_build_cp(struct ccw_device *cdev) 352 { 353 struct ccw_request *req = &cdev->private->req; 354 struct ccw1 *cp = cdev->private->iccws; 355 int i = 8 - ffs(req->lpm); 356 357 /* Channel program setup. */ 358 cp->cmd_code = CCW_CMD_SENSE_PGID; 359 cp->cda = (u32) (addr_t) &cdev->private->pgid[i]; 360 cp->count = sizeof(struct pgid); 361 cp->flags = CCW_FLAG_SLI; 362 req->cp = cp; 363 } 364 365 /* 366 * Perform SENSE PGID on a single path. 367 */ 368 static void snid_do(struct ccw_device *cdev) 369 { 370 struct subchannel *sch = to_subchannel(cdev->dev.parent); 371 struct ccw_request *req = &cdev->private->req; 372 373 /* Adjust lpm if paths are not set in pam. */ 374 req->lpm = lpm_adjust(req->lpm, sch->schib.pmcw.pam); 375 if (!req->lpm) 376 goto out_nopath; 377 snid_build_cp(cdev); 378 ccw_request_start(cdev); 379 return; 380 381 out_nopath: 382 snid_done(cdev, cdev->private->pgid_valid_mask ? 0 : -EACCES); 383 } 384 385 /* 386 * Process SENSE PGID request result for single path. 387 */ 388 static void snid_callback(struct ccw_device *cdev, void *data, int rc) 389 { 390 struct ccw_request *req = &cdev->private->req; 391 392 if (rc == 0) 393 cdev->private->pgid_valid_mask |= req->lpm; 394 else if (rc != -EACCES) 395 goto err; 396 req->lpm >>= 1; 397 snid_do(cdev); 398 return; 399 400 err: 401 snid_done(cdev, rc); 402 } 403 404 /* 405 * Perform path verification. 406 */ 407 static void verify_start(struct ccw_device *cdev) 408 { 409 struct subchannel *sch = to_subchannel(cdev->dev.parent); 410 struct ccw_request *req = &cdev->private->req; 411 struct ccw_dev_id *devid = &cdev->private->dev_id; 412 413 sch->vpm = 0; 414 /* Initialize request data. */ 415 memset(req, 0, sizeof(*req)); 416 req->timeout = PGID_TIMEOUT; 417 req->maxretries = PGID_RETRIES; 418 req->lpm = 0x80; 419 if (cdev->private->flags.pgroup) { 420 CIO_TRACE_EVENT(4, "snid"); 421 CIO_HEX_EVENT(4, devid, sizeof(*devid)); 422 req->callback = snid_callback; 423 snid_do(cdev); 424 } else { 425 CIO_TRACE_EVENT(4, "nop"); 426 CIO_HEX_EVENT(4, devid, sizeof(*devid)); 427 req->filter = nop_filter; 428 req->callback = nop_callback; 429 nop_do(cdev); 430 } 431 } 432 433 /** 434 * ccw_device_verify_start - perform path verification 435 * @cdev: ccw device 436 * 437 * Perform an I/O on each available channel path to @cdev to determine which 438 * paths are operational. The resulting path mask is stored in sch->vpm. 439 * If device options specify pathgrouping, establish a pathgroup for the 440 * operational paths. When finished, call ccw_device_verify_done with a 441 * return code specifying the result. 442 */ 443 void ccw_device_verify_start(struct ccw_device *cdev) 444 { 445 CIO_TRACE_EVENT(4, "vrfy"); 446 CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id)); 447 /* Initialize PGID data. */ 448 memset(cdev->private->pgid, 0, sizeof(cdev->private->pgid)); 449 cdev->private->pgid_valid_mask = 0; 450 /* 451 * Initialize pathgroup and multipath state with target values. 452 * They may change in the course of path verification. 453 */ 454 cdev->private->flags.pgroup = cdev->private->options.pgroup; 455 cdev->private->flags.mpath = cdev->private->options.mpath; 456 cdev->private->flags.doverify = 0; 457 verify_start(cdev); 458 } 459 460 /* 461 * Process disband SET PGID request result. 462 */ 463 static void disband_callback(struct ccw_device *cdev, void *data, int rc) 464 { 465 struct subchannel *sch = to_subchannel(cdev->dev.parent); 466 struct ccw_dev_id *id = &cdev->private->dev_id; 467 468 if (rc) 469 goto out; 470 /* Ensure consistent multipathing state at device and channel. */ 471 cdev->private->flags.mpath = 0; 472 if (sch->config.mp) { 473 sch->config.mp = 0; 474 rc = cio_commit_config(sch); 475 } 476 out: 477 CIO_MSG_EVENT(0, "disb: device 0.%x.%04x: rc=%d\n", id->ssid, id->devno, 478 rc); 479 ccw_device_disband_done(cdev, rc); 480 } 481 482 /** 483 * ccw_device_disband_start - disband pathgroup 484 * @cdev: ccw device 485 * 486 * Execute a SET PGID channel program on @cdev to disband a previously 487 * established pathgroup. When finished, call ccw_device_disband_done with 488 * a return code specifying the result. 489 */ 490 void ccw_device_disband_start(struct ccw_device *cdev) 491 { 492 struct subchannel *sch = to_subchannel(cdev->dev.parent); 493 struct ccw_request *req = &cdev->private->req; 494 u8 fn; 495 496 CIO_TRACE_EVENT(4, "disb"); 497 CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id)); 498 /* Request setup. */ 499 memset(req, 0, sizeof(*req)); 500 req->timeout = PGID_TIMEOUT; 501 req->maxretries = PGID_RETRIES; 502 req->lpm = sch->schib.pmcw.pam & sch->opm; 503 req->callback = disband_callback; 504 fn = SPID_FUNC_DISBAND; 505 if (cdev->private->flags.mpath) 506 fn |= SPID_FUNC_MULTI_PATH; 507 spid_build_cp(cdev, fn); 508 ccw_request_start(cdev); 509 } 510 511 static void stlck_build_cp(struct ccw_device *cdev, void *buf1, void *buf2) 512 { 513 struct ccw_request *req = &cdev->private->req; 514 struct ccw1 *cp = cdev->private->iccws; 515 516 cp[0].cmd_code = CCW_CMD_STLCK; 517 cp[0].cda = (u32) (addr_t) buf1; 518 cp[0].count = 32; 519 cp[0].flags = CCW_FLAG_CC; 520 cp[1].cmd_code = CCW_CMD_RELEASE; 521 cp[1].cda = (u32) (addr_t) buf2; 522 cp[1].count = 32; 523 cp[1].flags = 0; 524 req->cp = cp; 525 } 526 527 static void stlck_callback(struct ccw_device *cdev, void *data, int rc) 528 { 529 ccw_device_stlck_done(cdev, data, rc); 530 } 531 532 /** 533 * ccw_device_stlck_start - perform unconditional release 534 * @cdev: ccw device 535 * @data: data pointer to be passed to ccw_device_stlck_done 536 * @buf1: data pointer used in channel program 537 * @buf2: data pointer used in channel program 538 * 539 * Execute a channel program on @cdev to release an existing PGID reservation. 540 * When finished, call ccw_device_stlck_done with a return code specifying the 541 * result. 542 */ 543 void ccw_device_stlck_start(struct ccw_device *cdev, void *data, void *buf1, 544 void *buf2) 545 { 546 struct subchannel *sch = to_subchannel(cdev->dev.parent); 547 struct ccw_request *req = &cdev->private->req; 548 549 CIO_TRACE_EVENT(4, "stlck"); 550 CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id)); 551 /* Request setup. */ 552 memset(req, 0, sizeof(*req)); 553 req->timeout = PGID_TIMEOUT; 554 req->maxretries = PGID_RETRIES; 555 req->lpm = sch->schib.pmcw.pam & sch->opm; 556 req->data = data; 557 req->callback = stlck_callback; 558 stlck_build_cp(cdev, buf1, buf2); 559 ccw_request_start(cdev); 560 } 561 562