1// SPDX-License-Identifier: GPL-2.0+ 2/* 3 * ipmi_smic_sm.c 4 * 5 * The state-machine driver for an IPMI SMIC driver 6 * 7 * It started as a copy of Corey Minyard's driver for the KSC interface 8 * and the kernel patch "mmcdev-patch-245" by HP 9 * 10 * modified by: Hannes Schulz <schulz@schwaar.com> 11 * ipmi@schwaar.com 12 * 13 * 14 * Corey Minyard's driver for the KSC interface has the following 15 * copyright notice: 16 * Copyright 2002 MontaVista Software Inc. 17 * 18 * the kernel patch "mmcdev-patch-245" by HP has the following 19 * copyright notice: 20 * (c) Copyright 2001 Grant Grundler (c) Copyright 21 * 2001 Hewlett-Packard Company 22 */ 23 24#define DEBUG /* So dev_dbg() is always available. */ 25 26#include <linux/kernel.h> /* For printk. */ 27#include <linux/string.h> 28#include <linux/module.h> 29#include <linux/moduleparam.h> 30#include <linux/ipmi_msgdefs.h> /* for completion codes */ 31#include "ipmi_si_sm.h" 32 33/* smic_debug is a bit-field 34 * SMIC_DEBUG_ENABLE - turned on for now 35 * SMIC_DEBUG_MSG - commands and their responses 36 * SMIC_DEBUG_STATES - state machine 37*/ 38#define SMIC_DEBUG_STATES 4 39#define SMIC_DEBUG_MSG 2 40#define SMIC_DEBUG_ENABLE 1 41 42static int smic_debug = 1; 43module_param(smic_debug, int, 0644); 44MODULE_PARM_DESC(smic_debug, "debug bitmask, 1=enable, 2=messages, 4=states"); 45 46enum smic_states { 47 SMIC_IDLE, 48 SMIC_START_OP, 49 SMIC_OP_OK, 50 SMIC_WRITE_START, 51 SMIC_WRITE_NEXT, 52 SMIC_WRITE_END, 53 SMIC_WRITE2READ, 54 SMIC_READ_START, 55 SMIC_READ_NEXT, 56 SMIC_READ_END, 57 SMIC_HOSED 58}; 59 60#define MAX_SMIC_READ_SIZE 80 61#define MAX_SMIC_WRITE_SIZE 80 62#define SMIC_MAX_ERROR_RETRIES 3 63 64/* Timeouts in microseconds. */ 65#define SMIC_RETRY_TIMEOUT (2*USEC_PER_SEC) 66 67/* SMIC Flags Register Bits */ 68#define SMIC_RX_DATA_READY 0x80 69#define SMIC_TX_DATA_READY 0x40 70 71/* 72 * SMIC_SMI and SMIC_EVM_DATA_AVAIL are only used by 73 * a few systems, and then only by Systems Management 74 * Interrupts, not by the OS. Always ignore these bits. 75 * 76 */ 77#define SMIC_SMI 0x10 78#define SMIC_EVM_DATA_AVAIL 0x08 79#define SMIC_SMS_DATA_AVAIL 0x04 80#define SMIC_FLAG_BSY 0x01 81 82/* SMIC Error Codes */ 83#define EC_NO_ERROR 0x00 84#define EC_ABORTED 0x01 85#define EC_ILLEGAL_CONTROL 0x02 86#define EC_NO_RESPONSE 0x03 87#define EC_ILLEGAL_COMMAND 0x04 88#define EC_BUFFER_FULL 0x05 89 90struct si_sm_data { 91 enum smic_states state; 92 struct si_sm_io *io; 93 unsigned char write_data[MAX_SMIC_WRITE_SIZE]; 94 int write_pos; 95 int write_count; 96 int orig_write_count; 97 unsigned char read_data[MAX_SMIC_READ_SIZE]; 98 int read_pos; 99 int truncated; 100 unsigned int error_retries; 101 long smic_timeout; 102}; 103 104static unsigned int init_smic_data(struct si_sm_data *smic, 105 struct si_sm_io *io) 106{ 107 smic->state = SMIC_IDLE; 108 smic->io = io; 109 smic->write_pos = 0; 110 smic->write_count = 0; 111 smic->orig_write_count = 0; 112 smic->read_pos = 0; 113 smic->error_retries = 0; 114 smic->truncated = 0; 115 smic->smic_timeout = SMIC_RETRY_TIMEOUT; 116 117 /* We use 3 bytes of I/O. */ 118 return 3; 119} 120 121static int start_smic_transaction(struct si_sm_data *smic, 122 unsigned char *data, unsigned int size) 123{ 124 unsigned int i; 125 126 if (size < 2) 127 return IPMI_REQ_LEN_INVALID_ERR; 128 if (size > MAX_SMIC_WRITE_SIZE) 129 return IPMI_REQ_LEN_EXCEEDED_ERR; 130 131 if ((smic->state != SMIC_IDLE) && (smic->state != SMIC_HOSED)) { 132 dev_warn(smic->io->dev, 133 "SMIC in invalid state %d\n", smic->state); 134 return IPMI_NOT_IN_MY_STATE_ERR; 135 } 136 137 if (smic_debug & SMIC_DEBUG_MSG) { 138 dev_dbg(smic->io->dev, "%s -", __func__); 139 for (i = 0; i < size; i++) 140 pr_cont(" %02x", data[i]); 141 pr_cont("\n"); 142 } 143 smic->error_retries = 0; 144 memcpy(smic->write_data, data, size); 145 smic->write_count = size; 146 smic->orig_write_count = size; 147 smic->write_pos = 0; 148 smic->read_pos = 0; 149 smic->state = SMIC_START_OP; 150 smic->smic_timeout = SMIC_RETRY_TIMEOUT; 151 return 0; 152} 153 154static int smic_get_result(struct si_sm_data *smic, 155 unsigned char *data, unsigned int length) 156{ 157 int i; 158 159 if (smic_debug & SMIC_DEBUG_MSG) { 160 dev_dbg(smic->io->dev, "smic_get result -"); 161 for (i = 0; i < smic->read_pos; i++) 162 pr_cont(" %02x", smic->read_data[i]); 163 pr_cont("\n"); 164 } 165 if (length < smic->read_pos) { 166 smic->read_pos = length; 167 smic->truncated = 1; 168 } 169 memcpy(data, smic->read_data, smic->read_pos); 170 171 if ((length >= 3) && (smic->read_pos < 3)) { 172 data[2] = IPMI_ERR_UNSPECIFIED; 173 smic->read_pos = 3; 174 } 175 if (smic->truncated) { 176 data[2] = IPMI_ERR_MSG_TRUNCATED; 177 smic->truncated = 0; 178 } 179 return smic->read_pos; 180} 181 182static inline unsigned char read_smic_flags(struct si_sm_data *smic) 183{ 184 return smic->io->inputb(smic->io, 2); 185} 186 187static inline unsigned char read_smic_status(struct si_sm_data *smic) 188{ 189 return smic->io->inputb(smic->io, 1); 190} 191 192static inline unsigned char read_smic_data(struct si_sm_data *smic) 193{ 194 return smic->io->inputb(smic->io, 0); 195} 196 197static inline void write_smic_flags(struct si_sm_data *smic, 198 unsigned char flags) 199{ 200 smic->io->outputb(smic->io, 2, flags); 201} 202 203static inline void write_smic_control(struct si_sm_data *smic, 204 unsigned char control) 205{ 206 smic->io->outputb(smic->io, 1, control); 207} 208 209static inline void write_si_sm_data(struct si_sm_data *smic, 210 unsigned char data) 211{ 212 smic->io->outputb(smic->io, 0, data); 213} 214 215static inline void start_error_recovery(struct si_sm_data *smic, char *reason) 216{ 217 (smic->error_retries)++; 218 if (smic->error_retries > SMIC_MAX_ERROR_RETRIES) { 219 if (smic_debug & SMIC_DEBUG_ENABLE) 220 pr_warn("ipmi_smic_drv: smic hosed: %s\n", reason); 221 smic->state = SMIC_HOSED; 222 } else { 223 smic->write_count = smic->orig_write_count; 224 smic->write_pos = 0; 225 smic->read_pos = 0; 226 smic->state = SMIC_START_OP; 227 smic->smic_timeout = SMIC_RETRY_TIMEOUT; 228 } 229} 230 231static inline void write_next_byte(struct si_sm_data *smic) 232{ 233 write_si_sm_data(smic, smic->write_data[smic->write_pos]); 234 (smic->write_pos)++; 235 (smic->write_count)--; 236} 237 238static inline void read_next_byte(struct si_sm_data *smic) 239{ 240 if (smic->read_pos >= MAX_SMIC_READ_SIZE) { 241 read_smic_data(smic); 242 smic->truncated = 1; 243 } else { 244 smic->read_data[smic->read_pos] = read_smic_data(smic); 245 smic->read_pos++; 246 } 247} 248 249/* SMIC Control/Status Code Components */ 250#define SMIC_GET_STATUS 0x00 /* Control form's name */ 251#define SMIC_READY 0x00 /* Status form's name */ 252#define SMIC_WR_START 0x01 /* Unified Control/Status names... */ 253#define SMIC_WR_NEXT 0x02 254#define SMIC_WR_END 0x03 255#define SMIC_RD_START 0x04 256#define SMIC_RD_NEXT 0x05 257#define SMIC_RD_END 0x06 258#define SMIC_CODE_MASK 0x0f 259 260#define SMIC_CONTROL 0x00 261#define SMIC_STATUS 0x80 262#define SMIC_CS_MASK 0x80 263 264#define SMIC_SMS 0x40 265#define SMIC_SMM 0x60 266#define SMIC_STREAM_MASK 0x60 267 268/* SMIC Control Codes */ 269#define SMIC_CC_SMS_GET_STATUS (SMIC_CONTROL|SMIC_SMS|SMIC_GET_STATUS) 270#define SMIC_CC_SMS_WR_START (SMIC_CONTROL|SMIC_SMS|SMIC_WR_START) 271#define SMIC_CC_SMS_WR_NEXT (SMIC_CONTROL|SMIC_SMS|SMIC_WR_NEXT) 272#define SMIC_CC_SMS_WR_END (SMIC_CONTROL|SMIC_SMS|SMIC_WR_END) 273#define SMIC_CC_SMS_RD_START (SMIC_CONTROL|SMIC_SMS|SMIC_RD_START) 274#define SMIC_CC_SMS_RD_NEXT (SMIC_CONTROL|SMIC_SMS|SMIC_RD_NEXT) 275#define SMIC_CC_SMS_RD_END (SMIC_CONTROL|SMIC_SMS|SMIC_RD_END) 276 277#define SMIC_CC_SMM_GET_STATUS (SMIC_CONTROL|SMIC_SMM|SMIC_GET_STATUS) 278#define SMIC_CC_SMM_WR_START (SMIC_CONTROL|SMIC_SMM|SMIC_WR_START) 279#define SMIC_CC_SMM_WR_NEXT (SMIC_CONTROL|SMIC_SMM|SMIC_WR_NEXT) 280#define SMIC_CC_SMM_WR_END (SMIC_CONTROL|SMIC_SMM|SMIC_WR_END) 281#define SMIC_CC_SMM_RD_START (SMIC_CONTROL|SMIC_SMM|SMIC_RD_START) 282#define SMIC_CC_SMM_RD_NEXT (SMIC_CONTROL|SMIC_SMM|SMIC_RD_NEXT) 283#define SMIC_CC_SMM_RD_END (SMIC_CONTROL|SMIC_SMM|SMIC_RD_END) 284 285/* SMIC Status Codes */ 286#define SMIC_SC_SMS_READY (SMIC_STATUS|SMIC_SMS|SMIC_READY) 287#define SMIC_SC_SMS_WR_START (SMIC_STATUS|SMIC_SMS|SMIC_WR_START) 288#define SMIC_SC_SMS_WR_NEXT (SMIC_STATUS|SMIC_SMS|SMIC_WR_NEXT) 289#define SMIC_SC_SMS_WR_END (SMIC_STATUS|SMIC_SMS|SMIC_WR_END) 290#define SMIC_SC_SMS_RD_START (SMIC_STATUS|SMIC_SMS|SMIC_RD_START) 291#define SMIC_SC_SMS_RD_NEXT (SMIC_STATUS|SMIC_SMS|SMIC_RD_NEXT) 292#define SMIC_SC_SMS_RD_END (SMIC_STATUS|SMIC_SMS|SMIC_RD_END) 293 294#define SMIC_SC_SMM_READY (SMIC_STATUS|SMIC_SMM|SMIC_READY) 295#define SMIC_SC_SMM_WR_START (SMIC_STATUS|SMIC_SMM|SMIC_WR_START) 296#define SMIC_SC_SMM_WR_NEXT (SMIC_STATUS|SMIC_SMM|SMIC_WR_NEXT) 297#define SMIC_SC_SMM_WR_END (SMIC_STATUS|SMIC_SMM|SMIC_WR_END) 298#define SMIC_SC_SMM_RD_START (SMIC_STATUS|SMIC_SMM|SMIC_RD_START) 299#define SMIC_SC_SMM_RD_NEXT (SMIC_STATUS|SMIC_SMM|SMIC_RD_NEXT) 300#define SMIC_SC_SMM_RD_END (SMIC_STATUS|SMIC_SMM|SMIC_RD_END) 301 302/* these are the control/status codes we actually use 303 SMIC_CC_SMS_GET_STATUS 0x40 304 SMIC_CC_SMS_WR_START 0x41 305 SMIC_CC_SMS_WR_NEXT 0x42 306 SMIC_CC_SMS_WR_END 0x43 307 SMIC_CC_SMS_RD_START 0x44 308 SMIC_CC_SMS_RD_NEXT 0x45 309 SMIC_CC_SMS_RD_END 0x46 310 311 SMIC_SC_SMS_READY 0xC0 312 SMIC_SC_SMS_WR_START 0xC1 313 SMIC_SC_SMS_WR_NEXT 0xC2 314 SMIC_SC_SMS_WR_END 0xC3 315 SMIC_SC_SMS_RD_START 0xC4 316 SMIC_SC_SMS_RD_NEXT 0xC5 317 SMIC_SC_SMS_RD_END 0xC6 318*/ 319 320static enum si_sm_result smic_event(struct si_sm_data *smic, long time) 321{ 322 unsigned char status; 323 unsigned char flags; 324 unsigned char data; 325 326 if (smic->state == SMIC_HOSED) { 327 init_smic_data(smic, smic->io); 328 return SI_SM_HOSED; 329 } 330 if (smic->state != SMIC_IDLE) { 331 if (smic_debug & SMIC_DEBUG_STATES) 332 dev_dbg(smic->io->dev, 333 "%s - smic->smic_timeout = %ld, time = %ld\n", 334 __func__, smic->smic_timeout, time); 335 /* 336 * FIXME: smic_event is sometimes called with time > 337 * SMIC_RETRY_TIMEOUT 338 */ 339 if (time < SMIC_RETRY_TIMEOUT) { 340 smic->smic_timeout -= time; 341 if (smic->smic_timeout < 0) { 342 start_error_recovery(smic, "smic timed out."); 343 return SI_SM_CALL_WITH_DELAY; 344 } 345 } 346 } 347 flags = read_smic_flags(smic); 348 if (flags & SMIC_FLAG_BSY) 349 return SI_SM_CALL_WITH_DELAY; 350 351 status = read_smic_status(smic); 352 if (smic_debug & SMIC_DEBUG_STATES) 353 dev_dbg(smic->io->dev, 354 "%s - state = %d, flags = 0x%02x, status = 0x%02x\n", 355 __func__, smic->state, flags, status); 356 357 switch (smic->state) { 358 case SMIC_IDLE: 359 /* in IDLE we check for available messages */ 360 if (flags & SMIC_SMS_DATA_AVAIL) 361 return SI_SM_ATTN; 362 return SI_SM_IDLE; 363 364 case SMIC_START_OP: 365 /* sanity check whether smic is really idle */ 366 write_smic_control(smic, SMIC_CC_SMS_GET_STATUS); 367 write_smic_flags(smic, flags | SMIC_FLAG_BSY); 368 smic->state = SMIC_OP_OK; 369 break; 370 371 case SMIC_OP_OK: 372 if (status != SMIC_SC_SMS_READY) { 373 /* this should not happen */ 374 start_error_recovery(smic, 375 "state = SMIC_OP_OK," 376 " status != SMIC_SC_SMS_READY"); 377 return SI_SM_CALL_WITH_DELAY; 378 } 379 /* OK so far; smic is idle let us start ... */ 380 write_smic_control(smic, SMIC_CC_SMS_WR_START); 381 write_next_byte(smic); 382 write_smic_flags(smic, flags | SMIC_FLAG_BSY); 383 smic->state = SMIC_WRITE_START; 384 break; 385 386 case SMIC_WRITE_START: 387 if (status != SMIC_SC_SMS_WR_START) { 388 start_error_recovery(smic, 389 "state = SMIC_WRITE_START, " 390 "status != SMIC_SC_SMS_WR_START"); 391 return SI_SM_CALL_WITH_DELAY; 392 } 393 /* 394 * we must not issue WR_(NEXT|END) unless 395 * TX_DATA_READY is set 396 * */ 397 if (flags & SMIC_TX_DATA_READY) { 398 if (smic->write_count == 1) { 399 /* last byte */ 400 write_smic_control(smic, SMIC_CC_SMS_WR_END); 401 smic->state = SMIC_WRITE_END; 402 } else { 403 write_smic_control(smic, SMIC_CC_SMS_WR_NEXT); 404 smic->state = SMIC_WRITE_NEXT; 405 } 406 write_next_byte(smic); 407 write_smic_flags(smic, flags | SMIC_FLAG_BSY); 408 } else 409 return SI_SM_CALL_WITH_DELAY; 410 break; 411 412 case SMIC_WRITE_NEXT: 413 if (status != SMIC_SC_SMS_WR_NEXT) { 414 start_error_recovery(smic, 415 "state = SMIC_WRITE_NEXT, " 416 "status != SMIC_SC_SMS_WR_NEXT"); 417 return SI_SM_CALL_WITH_DELAY; 418 } 419 /* this is the same code as in SMIC_WRITE_START */ 420 if (flags & SMIC_TX_DATA_READY) { 421 if (smic->write_count == 1) { 422 write_smic_control(smic, SMIC_CC_SMS_WR_END); 423 smic->state = SMIC_WRITE_END; 424 } else { 425 write_smic_control(smic, SMIC_CC_SMS_WR_NEXT); 426 smic->state = SMIC_WRITE_NEXT; 427 } 428 write_next_byte(smic); 429 write_smic_flags(smic, flags | SMIC_FLAG_BSY); 430 } else 431 return SI_SM_CALL_WITH_DELAY; 432 break; 433 434 case SMIC_WRITE_END: 435 if (status != SMIC_SC_SMS_WR_END) { 436 start_error_recovery(smic, 437 "state = SMIC_WRITE_END, " 438 "status != SMIC_SC_SMS_WR_END"); 439 return SI_SM_CALL_WITH_DELAY; 440 } 441 /* data register holds an error code */ 442 data = read_smic_data(smic); 443 if (data != 0) { 444 if (smic_debug & SMIC_DEBUG_ENABLE) 445 dev_dbg(smic->io->dev, 446 "SMIC_WRITE_END: data = %02x\n", 447 data); 448 start_error_recovery(smic, 449 "state = SMIC_WRITE_END, " 450 "data != SUCCESS"); 451 return SI_SM_CALL_WITH_DELAY; 452 } else 453 smic->state = SMIC_WRITE2READ; 454 break; 455 456 case SMIC_WRITE2READ: 457 /* 458 * we must wait for RX_DATA_READY to be set before we 459 * can continue 460 */ 461 if (flags & SMIC_RX_DATA_READY) { 462 write_smic_control(smic, SMIC_CC_SMS_RD_START); 463 write_smic_flags(smic, flags | SMIC_FLAG_BSY); 464 smic->state = SMIC_READ_START; 465 } else 466 return SI_SM_CALL_WITH_DELAY; 467 break; 468 469 case SMIC_READ_START: 470 if (status != SMIC_SC_SMS_RD_START) { 471 start_error_recovery(smic, 472 "state = SMIC_READ_START, " 473 "status != SMIC_SC_SMS_RD_START"); 474 return SI_SM_CALL_WITH_DELAY; 475 } 476 if (flags & SMIC_RX_DATA_READY) { 477 read_next_byte(smic); 478 write_smic_control(smic, SMIC_CC_SMS_RD_NEXT); 479 write_smic_flags(smic, flags | SMIC_FLAG_BSY); 480 smic->state = SMIC_READ_NEXT; 481 } else 482 return SI_SM_CALL_WITH_DELAY; 483 break; 484 485 case SMIC_READ_NEXT: 486 switch (status) { 487 /* 488 * smic tells us that this is the last byte to be read 489 * --> clean up 490 */ 491 case SMIC_SC_SMS_RD_END: 492 read_next_byte(smic); 493 write_smic_control(smic, SMIC_CC_SMS_RD_END); 494 write_smic_flags(smic, flags | SMIC_FLAG_BSY); 495 smic->state = SMIC_READ_END; 496 break; 497 case SMIC_SC_SMS_RD_NEXT: 498 if (flags & SMIC_RX_DATA_READY) { 499 read_next_byte(smic); 500 write_smic_control(smic, SMIC_CC_SMS_RD_NEXT); 501 write_smic_flags(smic, flags | SMIC_FLAG_BSY); 502 smic->state = SMIC_READ_NEXT; 503 } else 504 return SI_SM_CALL_WITH_DELAY; 505 break; 506 default: 507 start_error_recovery( 508 smic, 509 "state = SMIC_READ_NEXT, " 510 "status != SMIC_SC_SMS_RD_(NEXT|END)"); 511 return SI_SM_CALL_WITH_DELAY; 512 } 513 break; 514 515 case SMIC_READ_END: 516 if (status != SMIC_SC_SMS_READY) { 517 start_error_recovery(smic, 518 "state = SMIC_READ_END, " 519 "status != SMIC_SC_SMS_READY"); 520 return SI_SM_CALL_WITH_DELAY; 521 } 522 data = read_smic_data(smic); 523 /* data register holds an error code */ 524 if (data != 0) { 525 if (smic_debug & SMIC_DEBUG_ENABLE) 526 dev_dbg(smic->io->dev, 527 "SMIC_READ_END: data = %02x\n", 528 data); 529 start_error_recovery(smic, 530 "state = SMIC_READ_END, " 531 "data != SUCCESS"); 532 return SI_SM_CALL_WITH_DELAY; 533 } else { 534 smic->state = SMIC_IDLE; 535 return SI_SM_TRANSACTION_COMPLETE; 536 } 537 538 case SMIC_HOSED: 539 init_smic_data(smic, smic->io); 540 return SI_SM_HOSED; 541 542 default: 543 if (smic_debug & SMIC_DEBUG_ENABLE) { 544 dev_dbg(smic->io->dev, 545 "smic->state = %d\n", smic->state); 546 start_error_recovery(smic, "state = UNKNOWN"); 547 return SI_SM_CALL_WITH_DELAY; 548 } 549 } 550 smic->smic_timeout = SMIC_RETRY_TIMEOUT; 551 return SI_SM_CALL_WITHOUT_DELAY; 552} 553 554static int smic_detect(struct si_sm_data *smic) 555{ 556 /* 557 * It's impossible for the SMIC fnags register to be all 1's, 558 * (assuming a properly functioning, self-initialized BMC) 559 * but that's what you get from reading a bogus address, so we 560 * test that first. 561 */ 562 if (read_smic_flags(smic) == 0xff) 563 return 1; 564 565 return 0; 566} 567 568static void smic_cleanup(struct si_sm_data *kcs) 569{ 570} 571 572static int smic_size(void) 573{ 574 return sizeof(struct si_sm_data); 575} 576 577const struct si_sm_handlers smic_smi_handlers = { 578 .init_data = init_smic_data, 579 .start_transaction = start_smic_transaction, 580 .get_result = smic_get_result, 581 .event = smic_event, 582 .detect = smic_detect, 583 .cleanup = smic_cleanup, 584 .size = smic_size, 585}; 586