1 /* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */ 2 3 #if HAVE_CONFIG_H 4 #include "config.h" 5 #endif 6 7 #if HAVE_ENDIAN_H 8 #include <endian.h> 9 #endif 10 11 #include <assert.h> 12 #include <err.h> 13 #include <errno.h> 14 #include <inttypes.h> 15 #include <stdbool.h> 16 #include <stdlib.h> 17 #include <string.h> 18 19 #define pr_fmt(x) "astlpc: " x 20 21 #include "container_of.h" 22 #include "crc32.h" 23 #include "libmctp.h" 24 #include "libmctp-alloc.h" 25 #include "libmctp-log.h" 26 #include "libmctp-astlpc.h" 27 #include "range.h" 28 29 #ifdef MCTP_HAVE_FILEIO 30 31 #include <unistd.h> 32 #include <fcntl.h> 33 #include <sys/ioctl.h> 34 #include <sys/mman.h> 35 #include <linux/aspeed-lpc-ctrl.h> 36 37 /* kernel interface */ 38 static const char *kcs_path = "/dev/mctp0"; 39 static const char *lpc_path = "/dev/aspeed-lpc-ctrl"; 40 41 #endif 42 43 struct mctp_astlpc_buffer { 44 uint32_t offset; 45 uint32_t size; 46 }; 47 48 struct mctp_astlpc_layout { 49 struct mctp_astlpc_buffer rx; 50 struct mctp_astlpc_buffer tx; 51 }; 52 53 struct mctp_astlpc_protocol { 54 uint16_t version; 55 uint32_t (*packet_size)(uint32_t body); 56 uint32_t (*body_size)(uint32_t packet); 57 void (*pktbuf_protect)(struct mctp_pktbuf *pkt); 58 bool (*pktbuf_validate)(struct mctp_pktbuf *pkt); 59 }; 60 61 struct mctp_binding_astlpc { 62 struct mctp_binding binding; 63 64 void *lpc_map; 65 struct mctp_astlpc_layout layout; 66 67 uint8_t mode; 68 uint32_t requested_mtu; 69 70 const struct mctp_astlpc_protocol *proto; 71 72 /* direct ops data */ 73 struct mctp_binding_astlpc_ops ops; 74 void *ops_data; 75 76 /* fileio ops data */ 77 int kcs_fd; 78 uint8_t kcs_status; 79 80 bool running; 81 }; 82 83 #define binding_to_astlpc(b) \ 84 container_of(b, struct mctp_binding_astlpc, binding) 85 86 #define astlpc_prlog(ctx, lvl, fmt, ...) \ 87 do { \ 88 bool __bmc = ((ctx)->mode == MCTP_BINDING_ASTLPC_MODE_BMC); \ 89 mctp_prlog(lvl, pr_fmt("%s: " fmt), __bmc ? "bmc" : "host", \ 90 ##__VA_ARGS__); \ 91 } while (0) 92 93 #define astlpc_prerr(ctx, fmt, ...) \ 94 astlpc_prlog(ctx, MCTP_LOG_ERR, fmt, ##__VA_ARGS__) 95 #define astlpc_prwarn(ctx, fmt, ...) \ 96 astlpc_prlog(ctx, MCTP_LOG_WARNING, fmt, ##__VA_ARGS__) 97 #define astlpc_prinfo(ctx, fmt, ...) \ 98 astlpc_prlog(ctx, MCTP_LOG_INFO, fmt, ##__VA_ARGS__) 99 #define astlpc_prdebug(ctx, fmt, ...) \ 100 astlpc_prlog(ctx, MCTP_LOG_DEBUG, fmt, ##__VA_ARGS__) 101 102 /* clang-format off */ 103 #define ASTLPC_MCTP_MAGIC 0x4d435450 104 #define ASTLPC_VER_BAD 0 105 #define ASTLPC_VER_MIN 1 106 107 /* Support testing of new binding protocols */ 108 #ifndef ASTLPC_VER_CUR 109 #define ASTLPC_VER_CUR 3 110 #endif 111 /* clang-format on */ 112 113 #ifndef ARRAY_SIZE 114 #define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0])) 115 #endif 116 117 static uint32_t astlpc_packet_size_v1(uint32_t body) 118 { 119 assert((body + 4) > body); 120 121 return body + 4; 122 } 123 124 static uint32_t astlpc_body_size_v1(uint32_t packet) 125 { 126 assert((packet - 4) < packet); 127 128 return packet - 4; 129 } 130 131 void astlpc_pktbuf_protect_v1(struct mctp_pktbuf *pkt) 132 { 133 (void)pkt; 134 } 135 136 bool astlpc_pktbuf_validate_v1(struct mctp_pktbuf *pkt) 137 { 138 (void)pkt; 139 return true; 140 } 141 142 static uint32_t astlpc_packet_size_v3(uint32_t body) 143 { 144 assert((body + 4 + 4) > body); 145 146 return body + 4 + 4; 147 } 148 149 static uint32_t astlpc_body_size_v3(uint32_t packet) 150 { 151 assert((packet - 4 - 4) < packet); 152 153 return packet - 4 - 4; 154 } 155 156 void astlpc_pktbuf_protect_v3(struct mctp_pktbuf *pkt) 157 { 158 uint32_t code; 159 160 code = htobe32(crc32(mctp_pktbuf_hdr(pkt), mctp_pktbuf_size(pkt))); 161 mctp_prdebug("%s: 0x%" PRIx32, __func__, code); 162 mctp_pktbuf_push(pkt, &code, 4); 163 } 164 165 bool astlpc_pktbuf_validate_v3(struct mctp_pktbuf *pkt) 166 { 167 uint32_t code; 168 void *check; 169 170 code = be32toh(crc32(mctp_pktbuf_hdr(pkt), mctp_pktbuf_size(pkt) - 4)); 171 mctp_prdebug("%s: 0x%" PRIx32, __func__, code); 172 check = mctp_pktbuf_pop(pkt, 4); 173 return check && !memcmp(&code, check, 4); 174 } 175 176 static const struct mctp_astlpc_protocol astlpc_protocol_version[] = { 177 [0] = { 178 .version = 0, 179 .packet_size = NULL, 180 .body_size = NULL, 181 .pktbuf_protect = NULL, 182 .pktbuf_validate = NULL, 183 }, 184 [1] = { 185 .version = 1, 186 .packet_size = astlpc_packet_size_v1, 187 .body_size = astlpc_body_size_v1, 188 .pktbuf_protect = astlpc_pktbuf_protect_v1, 189 .pktbuf_validate = astlpc_pktbuf_validate_v1, 190 }, 191 [2] = { 192 .version = 2, 193 .packet_size = astlpc_packet_size_v1, 194 .body_size = astlpc_body_size_v1, 195 .pktbuf_protect = astlpc_pktbuf_protect_v1, 196 .pktbuf_validate = astlpc_pktbuf_validate_v1, 197 }, 198 [3] = { 199 .version = 3, 200 .packet_size = astlpc_packet_size_v3, 201 .body_size = astlpc_body_size_v3, 202 .pktbuf_protect = astlpc_pktbuf_protect_v3, 203 .pktbuf_validate = astlpc_pktbuf_validate_v3, 204 }, 205 }; 206 207 struct mctp_lpcmap_hdr { 208 uint32_t magic; 209 210 uint16_t bmc_ver_min; 211 uint16_t bmc_ver_cur; 212 uint16_t host_ver_min; 213 uint16_t host_ver_cur; 214 uint16_t negotiated_ver; 215 uint16_t pad0; 216 217 struct { 218 uint32_t rx_offset; 219 uint32_t rx_size; 220 uint32_t tx_offset; 221 uint32_t tx_size; 222 } layout; 223 } __attribute__((packed)); 224 225 static const uint32_t control_size = 0x100; 226 227 #define LPC_WIN_SIZE (1 * 1024 * 1024) 228 229 #define KCS_STATUS_BMC_READY 0x80 230 #define KCS_STATUS_CHANNEL_ACTIVE 0x40 231 #define KCS_STATUS_IBF 0x02 232 #define KCS_STATUS_OBF 0x01 233 234 static inline int mctp_astlpc_kcs_write(struct mctp_binding_astlpc *astlpc, 235 enum mctp_binding_astlpc_kcs_reg reg, 236 uint8_t val) 237 { 238 return astlpc->ops.kcs_write(astlpc->ops_data, reg, val); 239 } 240 241 static inline int mctp_astlpc_kcs_read(struct mctp_binding_astlpc *astlpc, 242 enum mctp_binding_astlpc_kcs_reg reg, 243 uint8_t *val) 244 { 245 return astlpc->ops.kcs_read(astlpc->ops_data, reg, val); 246 } 247 248 static inline int mctp_astlpc_lpc_write(struct mctp_binding_astlpc *astlpc, 249 const void *buf, long offset, 250 size_t len) 251 { 252 astlpc_prdebug(astlpc, "%s: %zu bytes to 0x%lx", __func__, len, offset); 253 254 assert(offset >= 0); 255 256 /* Indirect access */ 257 if (astlpc->ops.lpc_write) { 258 void *data = astlpc->ops_data; 259 260 return astlpc->ops.lpc_write(data, buf, offset, len); 261 } 262 263 /* Direct mapping */ 264 assert(astlpc->lpc_map); 265 memcpy(&((char *)astlpc->lpc_map)[offset], buf, len); 266 267 return 0; 268 } 269 270 static inline int mctp_astlpc_lpc_read(struct mctp_binding_astlpc *astlpc, 271 void *buf, long offset, size_t len) 272 { 273 astlpc_prdebug(astlpc, "%s: %zu bytes from 0x%lx", __func__, len, 274 offset); 275 276 assert(offset >= 0); 277 278 /* Indirect access */ 279 if (astlpc->ops.lpc_read) { 280 void *data = astlpc->ops_data; 281 282 return astlpc->ops.lpc_read(data, buf, offset, len); 283 } 284 285 /* Direct mapping */ 286 assert(astlpc->lpc_map); 287 memcpy(buf, &((char *)astlpc->lpc_map)[offset], len); 288 289 return 0; 290 } 291 292 static int mctp_astlpc_kcs_set_status(struct mctp_binding_astlpc *astlpc, 293 uint8_t status) 294 { 295 uint8_t data; 296 int rc; 297 298 /* Since we're setting the status register, we want the other endpoint 299 * to be interrupted. However, some hardware may only raise a host-side 300 * interrupt on an ODR event. 301 * So, write a dummy value of 0xff to ODR, which will ensure that an 302 * interrupt is triggered, and can be ignored by the host. 303 */ 304 data = 0xff; 305 306 rc = mctp_astlpc_kcs_write(astlpc, MCTP_ASTLPC_KCS_REG_STATUS, status); 307 if (rc) { 308 astlpc_prwarn(astlpc, "KCS status write failed"); 309 return -1; 310 } 311 312 rc = mctp_astlpc_kcs_write(astlpc, MCTP_ASTLPC_KCS_REG_DATA, data); 313 if (rc) { 314 astlpc_prwarn(astlpc, "KCS dummy data write failed"); 315 return -1; 316 } 317 318 return 0; 319 } 320 321 static int mctp_astlpc_layout_read(struct mctp_binding_astlpc *astlpc, 322 struct mctp_astlpc_layout *layout) 323 { 324 struct mctp_lpcmap_hdr hdr; 325 int rc; 326 327 rc = mctp_astlpc_lpc_read(astlpc, &hdr, 0, sizeof(hdr)); 328 if (rc < 0) 329 return rc; 330 331 /* Flip the buffers as the names are defined in terms of the host */ 332 if (astlpc->mode == MCTP_BINDING_ASTLPC_MODE_BMC) { 333 layout->rx.offset = be32toh(hdr.layout.tx_offset); 334 layout->rx.size = be32toh(hdr.layout.tx_size); 335 layout->tx.offset = be32toh(hdr.layout.rx_offset); 336 layout->tx.size = be32toh(hdr.layout.rx_size); 337 } else { 338 assert(astlpc->mode == MCTP_BINDING_ASTLPC_MODE_HOST); 339 340 layout->rx.offset = be32toh(hdr.layout.rx_offset); 341 layout->rx.size = be32toh(hdr.layout.rx_size); 342 layout->tx.offset = be32toh(hdr.layout.tx_offset); 343 layout->tx.size = be32toh(hdr.layout.tx_size); 344 } 345 346 return 0; 347 } 348 349 static int mctp_astlpc_layout_write(struct mctp_binding_astlpc *astlpc, 350 struct mctp_astlpc_layout *layout) 351 { 352 uint32_t rx_size_be; 353 354 if (astlpc->mode == MCTP_BINDING_ASTLPC_MODE_BMC) { 355 struct mctp_lpcmap_hdr hdr; 356 357 /* 358 * Flip the buffers as the names are defined in terms of the 359 * host 360 */ 361 hdr.layout.rx_offset = htobe32(layout->tx.offset); 362 hdr.layout.rx_size = htobe32(layout->tx.size); 363 hdr.layout.tx_offset = htobe32(layout->rx.offset); 364 hdr.layout.tx_size = htobe32(layout->rx.size); 365 366 return mctp_astlpc_lpc_write(astlpc, &hdr.layout, 367 offsetof(struct mctp_lpcmap_hdr, layout), 368 sizeof(hdr.layout)); 369 } 370 371 assert(astlpc->mode == MCTP_BINDING_ASTLPC_MODE_HOST); 372 373 /* 374 * As of v2 we only need to write rx_size - the offsets are controlled 375 * by the BMC, as is the BMC's rx_size (host tx_size). 376 */ 377 rx_size_be = htobe32(layout->rx.size); 378 return mctp_astlpc_lpc_write(astlpc, &rx_size_be, 379 offsetof(struct mctp_lpcmap_hdr, layout.rx_size), 380 sizeof(rx_size_be)); 381 } 382 383 static bool 384 mctp_astlpc_buffer_validate(const struct mctp_binding_astlpc *astlpc, 385 const struct mctp_astlpc_buffer *buf, 386 const char *name) 387 { 388 /* Check for overflow */ 389 if (buf->offset + buf->size < buf->offset) { 390 mctp_prerr( 391 "%s packet buffer parameters overflow: offset: 0x%" PRIx32 392 ", size: %" PRIu32, 393 name, buf->offset, buf->size); 394 return false; 395 } 396 397 /* Check that the buffers are contained within the allocated space */ 398 if (buf->offset + buf->size > LPC_WIN_SIZE) { 399 mctp_prerr( 400 "%s packet buffer parameters exceed %uM window size: offset: 0x%" PRIx32 401 ", size: %" PRIu32, 402 name, (LPC_WIN_SIZE / (1024 * 1024)), buf->offset, 403 buf->size); 404 return false; 405 } 406 407 /* Check that the baseline transmission unit is supported */ 408 if (buf->size < astlpc->proto->packet_size(MCTP_PACKET_SIZE(MCTP_BTU))) { 409 mctp_prerr( 410 "%s packet buffer too small: Require %" PRIu32 " bytes to support the %u byte baseline transmission unit, found %" PRIu32, 411 name, 412 astlpc->proto->packet_size(MCTP_PACKET_SIZE(MCTP_BTU)), 413 MCTP_BTU, buf->size); 414 return false; 415 } 416 417 /* Check for overlap with the control space */ 418 if (buf->offset < control_size) { 419 mctp_prerr( 420 "%s packet buffer overlaps control region {0x%" PRIx32 421 ", %" PRIu32 "}: Rx {0x%" PRIx32 ", %" PRIu32 "}", 422 name, 0U, control_size, buf->offset, buf->size); 423 return false; 424 } 425 426 return true; 427 } 428 429 static bool 430 mctp_astlpc_layout_validate(const struct mctp_binding_astlpc *astlpc, 431 const struct mctp_astlpc_layout *layout) 432 { 433 const struct mctp_astlpc_buffer *rx = &layout->rx; 434 const struct mctp_astlpc_buffer *tx = &layout->tx; 435 bool rx_valid, tx_valid; 436 437 rx_valid = mctp_astlpc_buffer_validate(astlpc, rx, "Rx"); 438 tx_valid = mctp_astlpc_buffer_validate(astlpc, tx, "Tx"); 439 440 if (!(rx_valid && tx_valid)) 441 return false; 442 443 /* Check that the buffers are disjoint */ 444 if ((rx->offset <= tx->offset && rx->offset + rx->size > tx->offset) || 445 (tx->offset <= rx->offset && tx->offset + tx->size > rx->offset)) { 446 mctp_prerr("Rx and Tx packet buffers overlap: Rx {0x%" PRIx32 447 ", %" PRIu32 "}, Tx {0x%" PRIx32 ", %" PRIu32 "}", 448 rx->offset, rx->size, tx->offset, tx->size); 449 return false; 450 } 451 452 return true; 453 } 454 455 static int mctp_astlpc_init_bmc(struct mctp_binding_astlpc *astlpc) 456 { 457 struct mctp_lpcmap_hdr hdr = { 0 }; 458 uint8_t status; 459 uint32_t sz; 460 461 /* 462 * The largest buffer size is half of the allocated MCTP space 463 * excluding the control space. 464 */ 465 sz = ((LPC_WIN_SIZE - control_size) / 2); 466 467 /* 468 * Trim the MTU to a multiple of 16 to meet the requirements of 12.17 469 * Query Hop in DSP0236 v1.3.0. 470 */ 471 sz = MCTP_BODY_SIZE(astlpc->proto->body_size(sz)); 472 sz &= ~0xfUL; 473 sz = astlpc->proto->packet_size(MCTP_PACKET_SIZE(sz)); 474 475 if (astlpc->requested_mtu) { 476 uint32_t rpkt, rmtu; 477 478 rmtu = astlpc->requested_mtu; 479 rpkt = astlpc->proto->packet_size(MCTP_PACKET_SIZE(rmtu)); 480 sz = MIN(sz, rpkt); 481 } 482 483 /* Flip the buffers as the names are defined in terms of the host */ 484 astlpc->layout.tx.offset = control_size; 485 astlpc->layout.tx.size = sz; 486 astlpc->layout.rx.offset = 487 astlpc->layout.tx.offset + astlpc->layout.tx.size; 488 astlpc->layout.rx.size = sz; 489 490 if (!mctp_astlpc_layout_validate(astlpc, &astlpc->layout)) { 491 astlpc_prerr(astlpc, "Cannot support an MTU of %" PRIu32, sz); 492 return -EINVAL; 493 } 494 495 hdr = (struct mctp_lpcmap_hdr){ 496 .magic = htobe32(ASTLPC_MCTP_MAGIC), 497 .bmc_ver_min = htobe16(ASTLPC_VER_MIN), 498 .bmc_ver_cur = htobe16(ASTLPC_VER_CUR), 499 500 /* Flip the buffers back as we're now describing the host's 501 * configuration to the host */ 502 .layout.rx_offset = htobe32(astlpc->layout.tx.offset), 503 .layout.rx_size = htobe32(astlpc->layout.tx.size), 504 .layout.tx_offset = htobe32(astlpc->layout.rx.offset), 505 .layout.tx_size = htobe32(astlpc->layout.rx.size), 506 }; 507 508 mctp_astlpc_lpc_write(astlpc, &hdr, 0, sizeof(hdr)); 509 510 /* 511 * Set status indicating that the BMC is now active. Be explicit about 512 * clearing OBF; we're reinitialising the binding and so any previous 513 * buffer state is irrelevant. 514 */ 515 status = KCS_STATUS_BMC_READY & ~KCS_STATUS_OBF; 516 return mctp_astlpc_kcs_set_status(astlpc, status); 517 } 518 519 static int mctp_binding_astlpc_start_bmc(struct mctp_binding *b) 520 { 521 struct mctp_binding_astlpc *astlpc = 522 container_of(b, struct mctp_binding_astlpc, binding); 523 524 astlpc->proto = &astlpc_protocol_version[ASTLPC_VER_CUR]; 525 526 return mctp_astlpc_init_bmc(astlpc); 527 } 528 529 static bool mctp_astlpc_validate_version(uint16_t bmc_ver_min, 530 uint16_t bmc_ver_cur, 531 uint16_t host_ver_min, 532 uint16_t host_ver_cur) 533 { 534 if (!(bmc_ver_min && bmc_ver_cur && host_ver_min && host_ver_cur)) { 535 mctp_prerr("Invalid version present in [%" PRIu16 ", %" PRIu16 536 "], [%" PRIu16 ", %" PRIu16 "]", 537 bmc_ver_min, bmc_ver_cur, host_ver_min, 538 host_ver_cur); 539 return false; 540 } else if (bmc_ver_min > bmc_ver_cur) { 541 mctp_prerr("Invalid bmc version range [%" PRIu16 ", %" PRIu16 542 "]", 543 bmc_ver_min, bmc_ver_cur); 544 return false; 545 } else if (host_ver_min > host_ver_cur) { 546 mctp_prerr("Invalid host version range [%" PRIu16 ", %" PRIu16 547 "]", 548 host_ver_min, host_ver_cur); 549 return false; 550 } else if ((host_ver_cur < bmc_ver_min) || 551 (host_ver_min > bmc_ver_cur)) { 552 mctp_prerr( 553 "Unable to satisfy version negotiation with ranges [%" PRIu16 554 ", %" PRIu16 "] and [%" PRIu16 ", %" PRIu16 "]", 555 bmc_ver_min, bmc_ver_cur, host_ver_min, host_ver_cur); 556 return false; 557 } 558 559 return true; 560 } 561 562 static int mctp_astlpc_negotiate_layout_host(struct mctp_binding_astlpc *astlpc) 563 { 564 struct mctp_astlpc_layout layout; 565 uint32_t rmtu; 566 uint32_t sz; 567 int rc; 568 569 rc = mctp_astlpc_layout_read(astlpc, &layout); 570 if (rc < 0) 571 return rc; 572 573 if (!mctp_astlpc_layout_validate(astlpc, &layout)) { 574 astlpc_prerr( 575 astlpc, 576 "BMC provided invalid buffer layout: Rx {0x%" PRIx32 577 ", %" PRIu32 "}, Tx {0x%" PRIx32 ", %" PRIu32 "}", 578 layout.rx.offset, layout.rx.size, layout.tx.offset, 579 layout.tx.size); 580 return -EINVAL; 581 } 582 583 astlpc_prinfo(astlpc, "Desire an MTU of %" PRIu32 " bytes", 584 astlpc->requested_mtu); 585 586 rmtu = astlpc->requested_mtu; 587 sz = astlpc->proto->packet_size(MCTP_PACKET_SIZE(rmtu)); 588 layout.rx.size = sz; 589 590 if (!mctp_astlpc_layout_validate(astlpc, &layout)) { 591 astlpc_prerr( 592 astlpc, 593 "Generated invalid buffer layout with size %" PRIu32 594 ": Rx {0x%" PRIx32 ", %" PRIu32 "}, Tx {0x%" PRIx32 595 ", %" PRIu32 "}", 596 sz, layout.rx.offset, layout.rx.size, layout.tx.offset, 597 layout.tx.size); 598 return -EINVAL; 599 } 600 601 astlpc_prinfo(astlpc, "Requesting MTU of %" PRIu32 " bytes", 602 astlpc->requested_mtu); 603 604 return mctp_astlpc_layout_write(astlpc, &layout); 605 } 606 607 static uint16_t mctp_astlpc_negotiate_version(uint16_t bmc_ver_min, 608 uint16_t bmc_ver_cur, 609 uint16_t host_ver_min, 610 uint16_t host_ver_cur) 611 { 612 if (!mctp_astlpc_validate_version(bmc_ver_min, bmc_ver_cur, 613 host_ver_min, host_ver_cur)) 614 return ASTLPC_VER_BAD; 615 616 if (bmc_ver_cur < host_ver_cur) 617 return bmc_ver_cur; 618 619 return host_ver_cur; 620 } 621 622 static int mctp_astlpc_init_host(struct mctp_binding_astlpc *astlpc) 623 { 624 const uint16_t ver_min_be = htobe16(ASTLPC_VER_MIN); 625 const uint16_t ver_cur_be = htobe16(ASTLPC_VER_CUR); 626 uint16_t bmc_ver_min, bmc_ver_cur, negotiated; 627 struct mctp_lpcmap_hdr hdr; 628 uint8_t status; 629 int rc; 630 631 rc = mctp_astlpc_kcs_read(astlpc, MCTP_ASTLPC_KCS_REG_STATUS, &status); 632 if (rc) { 633 mctp_prwarn("KCS status read failed"); 634 return rc; 635 } 636 637 astlpc->kcs_status = status; 638 639 if (!(status & KCS_STATUS_BMC_READY)) 640 return -EHOSTDOWN; 641 642 mctp_astlpc_lpc_read(astlpc, &hdr, 0, sizeof(hdr)); 643 644 bmc_ver_min = be16toh(hdr.bmc_ver_min); 645 bmc_ver_cur = be16toh(hdr.bmc_ver_cur); 646 647 /* Calculate the expected value of negotiated_ver */ 648 negotiated = mctp_astlpc_negotiate_version(bmc_ver_min, bmc_ver_cur, 649 ASTLPC_VER_MIN, 650 ASTLPC_VER_CUR); 651 if (!negotiated) { 652 astlpc_prerr(astlpc, "Cannot negotiate with invalid versions"); 653 return -EINVAL; 654 } 655 656 /* Assign protocol ops so we can calculate the packet buffer sizes */ 657 assert(negotiated < ARRAY_SIZE(astlpc_protocol_version)); 658 astlpc->proto = &astlpc_protocol_version[negotiated]; 659 660 /* Negotiate packet buffers in v2 style if the BMC supports it */ 661 if (negotiated >= 2) { 662 rc = mctp_astlpc_negotiate_layout_host(astlpc); 663 if (rc < 0) 664 return rc; 665 } 666 667 /* Advertise the host's supported protocol versions */ 668 mctp_astlpc_lpc_write(astlpc, &ver_min_be, 669 offsetof(struct mctp_lpcmap_hdr, host_ver_min), 670 sizeof(ver_min_be)); 671 672 mctp_astlpc_lpc_write(astlpc, &ver_cur_be, 673 offsetof(struct mctp_lpcmap_hdr, host_ver_cur), 674 sizeof(ver_cur_be)); 675 676 /* Send channel init command */ 677 rc = mctp_astlpc_kcs_write(astlpc, MCTP_ASTLPC_KCS_REG_DATA, 0x0); 678 if (rc) { 679 astlpc_prwarn(astlpc, "KCS write failed"); 680 } 681 682 /* 683 * Configure the host so `astlpc->proto->version == 0` holds until we 684 * receive a subsequent status update from the BMC. Until then, 685 * `astlpc->proto->version == 0` indicates that we're yet to complete 686 * the channel initialisation handshake. 687 * 688 * When the BMC provides a status update with KCS_STATUS_CHANNEL_ACTIVE 689 * set we will assign the appropriate protocol ops struct in accordance 690 * with `negotiated_ver`. 691 */ 692 astlpc->proto = &astlpc_protocol_version[ASTLPC_VER_BAD]; 693 694 return rc; 695 } 696 697 static int mctp_binding_astlpc_start_host(struct mctp_binding *b) 698 { 699 struct mctp_binding_astlpc *astlpc = 700 container_of(b, struct mctp_binding_astlpc, binding); 701 702 return mctp_astlpc_init_host(astlpc); 703 } 704 705 static bool __mctp_astlpc_kcs_ready(struct mctp_binding_astlpc *astlpc, 706 uint8_t status, bool is_write) 707 { 708 bool is_bmc; 709 bool ready_state; 710 uint8_t flag; 711 712 is_bmc = (astlpc->mode == MCTP_BINDING_ASTLPC_MODE_BMC); 713 flag = (is_bmc ^ is_write) ? KCS_STATUS_IBF : KCS_STATUS_OBF; 714 ready_state = is_write ? 0 : 1; 715 716 return !!(status & flag) == ready_state; 717 } 718 719 static inline bool 720 mctp_astlpc_kcs_read_ready(struct mctp_binding_astlpc *astlpc, uint8_t status) 721 { 722 return __mctp_astlpc_kcs_ready(astlpc, status, false); 723 } 724 725 static inline bool 726 mctp_astlpc_kcs_write_ready(struct mctp_binding_astlpc *astlpc, uint8_t status) 727 { 728 return __mctp_astlpc_kcs_ready(astlpc, status, true); 729 } 730 731 static int mctp_astlpc_kcs_send(struct mctp_binding_astlpc *astlpc, 732 uint8_t data) 733 { 734 uint8_t status; 735 int rc; 736 737 for (;;) { 738 rc = mctp_astlpc_kcs_read(astlpc, MCTP_ASTLPC_KCS_REG_STATUS, 739 &status); 740 if (rc) { 741 astlpc_prwarn(astlpc, "KCS status read failed"); 742 return -1; 743 } 744 if (mctp_astlpc_kcs_write_ready(astlpc, status)) 745 break; 746 /* todo: timeout */ 747 } 748 749 rc = mctp_astlpc_kcs_write(astlpc, MCTP_ASTLPC_KCS_REG_DATA, data); 750 if (rc) { 751 astlpc_prwarn(astlpc, "KCS data write failed"); 752 return -1; 753 } 754 755 return 0; 756 } 757 758 static int mctp_binding_astlpc_tx(struct mctp_binding *b, 759 struct mctp_pktbuf *pkt) 760 { 761 struct mctp_binding_astlpc *astlpc = binding_to_astlpc(b); 762 uint32_t len, len_be; 763 struct mctp_hdr *hdr; 764 765 hdr = mctp_pktbuf_hdr(pkt); 766 len = mctp_pktbuf_size(pkt); 767 768 astlpc_prdebug(astlpc, 769 "%s: Transmitting %" PRIu32 770 "-byte packet (%hhu, %hhu, 0x%hhx)", 771 __func__, len, hdr->src, hdr->dest, hdr->flags_seq_tag); 772 773 if (len > astlpc->proto->body_size(astlpc->layout.tx.size)) { 774 astlpc_prwarn(astlpc, "invalid TX len %" PRIu32 ": %" PRIu32, len, 775 astlpc->proto->body_size(astlpc->layout.tx.size)); 776 return -1; 777 } 778 779 len_be = htobe32(len); 780 mctp_astlpc_lpc_write(astlpc, &len_be, astlpc->layout.tx.offset, 781 sizeof(len_be)); 782 783 astlpc->proto->pktbuf_protect(pkt); 784 len = mctp_pktbuf_size(pkt); 785 786 mctp_astlpc_lpc_write(astlpc, hdr, astlpc->layout.tx.offset + 4, len); 787 788 mctp_binding_set_tx_enabled(b, false); 789 790 mctp_astlpc_kcs_send(astlpc, 0x1); 791 792 return 0; 793 } 794 795 static uint32_t mctp_astlpc_calculate_mtu(struct mctp_binding_astlpc *astlpc, 796 struct mctp_astlpc_layout *layout) 797 { 798 uint32_t low, high, limit, rpkt; 799 800 /* Derive the largest MTU the BMC _can_ support */ 801 low = MIN(astlpc->layout.rx.offset, astlpc->layout.tx.offset); 802 high = MAX(astlpc->layout.rx.offset, astlpc->layout.tx.offset); 803 limit = high - low; 804 805 /* Determine the largest MTU the BMC _wants_ to support */ 806 if (astlpc->requested_mtu) { 807 uint32_t rmtu = astlpc->requested_mtu; 808 809 rpkt = astlpc->proto->packet_size(MCTP_PACKET_SIZE(rmtu)); 810 limit = MIN(limit, rpkt); 811 } 812 813 /* Determine the accepted MTU, applied both directions by convention */ 814 rpkt = MIN(limit, layout->tx.size); 815 return MCTP_BODY_SIZE(astlpc->proto->body_size(rpkt)); 816 } 817 818 static int mctp_astlpc_negotiate_layout_bmc(struct mctp_binding_astlpc *astlpc) 819 { 820 struct mctp_astlpc_layout proposed, pending; 821 uint32_t sz, mtu; 822 int rc; 823 824 /* Do we have a valid protocol version? */ 825 if (!astlpc->proto->version) 826 return -EINVAL; 827 828 /* Extract the host's proposed layout */ 829 rc = mctp_astlpc_layout_read(astlpc, &proposed); 830 if (rc < 0) 831 return rc; 832 833 /* Do we have a reasonable layout? */ 834 if (!mctp_astlpc_layout_validate(astlpc, &proposed)) 835 return -EINVAL; 836 837 /* Negotiate the MTU */ 838 mtu = mctp_astlpc_calculate_mtu(astlpc, &proposed); 839 sz = astlpc->proto->packet_size(MCTP_PACKET_SIZE(mtu)); 840 841 /* 842 * Use symmetric MTUs by convention and to pass constraints in rx/tx 843 * functions 844 */ 845 pending = astlpc->layout; 846 pending.tx.size = sz; 847 pending.rx.size = sz; 848 849 if (mctp_astlpc_layout_validate(astlpc, &pending)) { 850 /* We found a sensible Rx MTU, so honour it */ 851 astlpc->layout = pending; 852 853 /* Enforce the negotiated MTU */ 854 rc = mctp_astlpc_layout_write(astlpc, &astlpc->layout); 855 if (rc < 0) 856 return rc; 857 858 astlpc_prinfo(astlpc, "Negotiated an MTU of %" PRIu32 " bytes", 859 mtu); 860 } else { 861 astlpc_prwarn(astlpc, "MTU negotiation failed"); 862 return -EINVAL; 863 } 864 865 if (astlpc->proto->version >= 2) 866 astlpc->binding.pkt_size = MCTP_PACKET_SIZE(mtu); 867 868 return 0; 869 } 870 871 static void mctp_astlpc_init_channel(struct mctp_binding_astlpc *astlpc) 872 { 873 uint16_t negotiated, negotiated_be; 874 struct mctp_lpcmap_hdr hdr; 875 uint8_t status; 876 int rc; 877 878 mctp_astlpc_lpc_read(astlpc, &hdr, 0, sizeof(hdr)); 879 880 /* Version negotiation */ 881 negotiated = 882 mctp_astlpc_negotiate_version(ASTLPC_VER_MIN, ASTLPC_VER_CUR, 883 be16toh(hdr.host_ver_min), 884 be16toh(hdr.host_ver_cur)); 885 886 /* MTU negotiation requires knowing which protocol we'll use */ 887 assert(negotiated < ARRAY_SIZE(astlpc_protocol_version)); 888 astlpc->proto = &astlpc_protocol_version[negotiated]; 889 890 /* Host Rx MTU negotiation: Failure terminates channel init */ 891 rc = mctp_astlpc_negotiate_layout_bmc(astlpc); 892 if (rc < 0) 893 negotiated = ASTLPC_VER_BAD; 894 895 /* Populate the negotiated version */ 896 negotiated_be = htobe16(negotiated); 897 mctp_astlpc_lpc_write(astlpc, &negotiated_be, 898 offsetof(struct mctp_lpcmap_hdr, negotiated_ver), 899 sizeof(negotiated_be)); 900 901 /* Finalise the configuration */ 902 status = KCS_STATUS_BMC_READY | KCS_STATUS_OBF; 903 if (negotiated > 0) { 904 astlpc_prinfo(astlpc, "Negotiated binding version %" PRIu16, 905 negotiated); 906 status |= KCS_STATUS_CHANNEL_ACTIVE; 907 } else { 908 astlpc_prerr(astlpc, "Failed to initialise channel"); 909 } 910 911 mctp_astlpc_kcs_set_status(astlpc, status); 912 913 mctp_binding_set_tx_enabled(&astlpc->binding, 914 status & KCS_STATUS_CHANNEL_ACTIVE); 915 } 916 917 static void mctp_astlpc_rx_start(struct mctp_binding_astlpc *astlpc) 918 { 919 struct mctp_pktbuf *pkt; 920 uint32_t body, packet; 921 922 mctp_astlpc_lpc_read(astlpc, &body, astlpc->layout.rx.offset, 923 sizeof(body)); 924 body = be32toh(body); 925 926 if (body > astlpc->proto->body_size(astlpc->layout.rx.size)) { 927 astlpc_prwarn(astlpc, "invalid RX len 0x%x", body); 928 return; 929 } 930 931 assert(astlpc->binding.pkt_size >= 0); 932 if (body > (uint32_t)astlpc->binding.pkt_size) { 933 astlpc_prwarn(astlpc, "invalid RX len 0x%x", body); 934 return; 935 } 936 937 /* Eliminate the medium-specific header that we just read */ 938 packet = astlpc->proto->packet_size(body) - 4; 939 pkt = mctp_pktbuf_alloc(&astlpc->binding, packet); 940 if (!pkt) 941 goto out_complete; 942 943 /* 944 * Read payload and medium-specific trailer from immediately after the 945 * medium-specific header. 946 */ 947 mctp_astlpc_lpc_read(astlpc, mctp_pktbuf_hdr(pkt), 948 astlpc->layout.rx.offset + 4, packet); 949 950 /* 951 * v3 will validate the CRC32 in the medium-specific trailer and adjust 952 * the packet size accordingly. On older protocols validation is a no-op 953 * that always returns true. 954 */ 955 if (astlpc->proto->pktbuf_validate(pkt)) { 956 mctp_bus_rx(&astlpc->binding, pkt); 957 } else { 958 /* TODO: Drop any associated assembly */ 959 mctp_pktbuf_free(pkt); 960 astlpc_prdebug(astlpc, "Dropped corrupt packet"); 961 } 962 963 out_complete: 964 mctp_astlpc_kcs_send(astlpc, 0x2); 965 } 966 967 static void mctp_astlpc_tx_complete(struct mctp_binding_astlpc *astlpc) 968 { 969 mctp_binding_set_tx_enabled(&astlpc->binding, true); 970 } 971 972 static int mctp_astlpc_finalise_channel(struct mctp_binding_astlpc *astlpc) 973 { 974 struct mctp_astlpc_layout layout; 975 uint16_t negotiated; 976 int rc; 977 978 rc = mctp_astlpc_lpc_read(astlpc, &negotiated, 979 offsetof(struct mctp_lpcmap_hdr, 980 negotiated_ver), 981 sizeof(negotiated)); 982 if (rc < 0) 983 return rc; 984 985 negotiated = be16toh(negotiated); 986 astlpc_prerr(astlpc, "Version negotiation got: %u", negotiated); 987 988 if (negotiated == ASTLPC_VER_BAD || negotiated < ASTLPC_VER_MIN || 989 negotiated > ASTLPC_VER_CUR) { 990 astlpc_prerr(astlpc, "Failed to negotiate version, got: %u\n", 991 negotiated); 992 return -EINVAL; 993 } 994 995 assert(negotiated < ARRAY_SIZE(astlpc_protocol_version)); 996 astlpc->proto = &astlpc_protocol_version[negotiated]; 997 998 rc = mctp_astlpc_layout_read(astlpc, &layout); 999 if (rc < 0) 1000 return rc; 1001 1002 if (!mctp_astlpc_layout_validate(astlpc, &layout)) { 1003 mctp_prerr("BMC proposed invalid buffer parameters"); 1004 return -EINVAL; 1005 } 1006 1007 astlpc->layout = layout; 1008 1009 if (negotiated >= 2) 1010 astlpc->binding.pkt_size = 1011 astlpc->proto->body_size(astlpc->layout.tx.size); 1012 1013 return 0; 1014 } 1015 1016 static int mctp_astlpc_update_channel(struct mctp_binding_astlpc *astlpc, 1017 uint8_t status) 1018 { 1019 uint8_t updated; 1020 int rc = 0; 1021 1022 assert(astlpc->mode == MCTP_BINDING_ASTLPC_MODE_HOST); 1023 1024 updated = astlpc->kcs_status ^ status; 1025 1026 astlpc_prdebug(astlpc, "%s: status: 0x%x, update: 0x%x", __func__, 1027 status, updated); 1028 1029 if (updated & KCS_STATUS_BMC_READY) { 1030 if (status & KCS_STATUS_BMC_READY) { 1031 astlpc->kcs_status = status; 1032 return astlpc->binding.start(&astlpc->binding); 1033 } else { 1034 mctp_binding_set_tx_enabled(&astlpc->binding, false); 1035 } 1036 } 1037 1038 if (astlpc->proto->version == 0 || 1039 updated & KCS_STATUS_CHANNEL_ACTIVE) { 1040 bool enable; 1041 1042 rc = mctp_astlpc_finalise_channel(astlpc); 1043 enable = (status & KCS_STATUS_CHANNEL_ACTIVE) && rc == 0; 1044 1045 mctp_binding_set_tx_enabled(&astlpc->binding, enable); 1046 } 1047 1048 astlpc->kcs_status = status; 1049 1050 return rc; 1051 } 1052 1053 int mctp_astlpc_poll(struct mctp_binding_astlpc *astlpc) 1054 { 1055 uint8_t status, data; 1056 int rc; 1057 1058 rc = mctp_astlpc_kcs_read(astlpc, MCTP_ASTLPC_KCS_REG_STATUS, &status); 1059 if (rc) { 1060 astlpc_prwarn(astlpc, "KCS read error"); 1061 return -1; 1062 } 1063 1064 astlpc_prdebug(astlpc, "%s: status: 0x%hhx", __func__, status); 1065 1066 if (!mctp_astlpc_kcs_read_ready(astlpc, status)) 1067 return 0; 1068 1069 rc = mctp_astlpc_kcs_read(astlpc, MCTP_ASTLPC_KCS_REG_DATA, &data); 1070 if (rc) { 1071 astlpc_prwarn(astlpc, "KCS data read error"); 1072 return -1; 1073 } 1074 1075 astlpc_prdebug(astlpc, "%s: data: 0x%hhx", __func__, data); 1076 1077 if (!astlpc->proto->version && !(data == 0x0 || data == 0xff)) { 1078 astlpc_prwarn(astlpc, "Invalid message for binding state: 0x%x", 1079 data); 1080 return 0; 1081 } 1082 1083 switch (data) { 1084 case 0x0: 1085 mctp_astlpc_init_channel(astlpc); 1086 break; 1087 case 0x1: 1088 mctp_astlpc_rx_start(astlpc); 1089 break; 1090 case 0x2: 1091 mctp_astlpc_tx_complete(astlpc); 1092 break; 1093 case 0xff: 1094 /* No responsibilities for the BMC on 0xff */ 1095 if (astlpc->mode == MCTP_BINDING_ASTLPC_MODE_HOST) { 1096 rc = mctp_astlpc_update_channel(astlpc, status); 1097 if (rc < 0) 1098 return rc; 1099 } 1100 break; 1101 default: 1102 astlpc_prwarn(astlpc, "unknown message 0x%x", data); 1103 } 1104 1105 /* Handle silent loss of bmc-ready */ 1106 if (astlpc->mode == MCTP_BINDING_ASTLPC_MODE_HOST) { 1107 if (!(status & KCS_STATUS_BMC_READY && data == 0xff)) 1108 return mctp_astlpc_update_channel(astlpc, status); 1109 } 1110 1111 return rc; 1112 } 1113 1114 /* allocate and basic initialisation */ 1115 static struct mctp_binding_astlpc *__mctp_astlpc_init(uint8_t mode, 1116 uint32_t mtu) 1117 { 1118 struct mctp_binding_astlpc *astlpc; 1119 1120 assert((mode == MCTP_BINDING_ASTLPC_MODE_BMC) || 1121 (mode == MCTP_BINDING_ASTLPC_MODE_HOST)); 1122 1123 astlpc = __mctp_alloc(sizeof(*astlpc)); 1124 if (!astlpc) 1125 return NULL; 1126 1127 memset(astlpc, 0, sizeof(*astlpc)); 1128 astlpc->mode = mode; 1129 astlpc->lpc_map = NULL; 1130 astlpc->requested_mtu = mtu; 1131 astlpc->binding.name = "astlpc"; 1132 astlpc->binding.version = 1; 1133 astlpc->binding.pkt_size = 1134 MCTP_PACKET_SIZE(mtu > MCTP_BTU ? mtu : MCTP_BTU); 1135 astlpc->binding.pkt_header = 4; 1136 astlpc->binding.pkt_trailer = 4; 1137 astlpc->binding.tx = mctp_binding_astlpc_tx; 1138 if (mode == MCTP_BINDING_ASTLPC_MODE_BMC) 1139 astlpc->binding.start = mctp_binding_astlpc_start_bmc; 1140 else if (mode == MCTP_BINDING_ASTLPC_MODE_HOST) 1141 astlpc->binding.start = mctp_binding_astlpc_start_host; 1142 else { 1143 astlpc_prerr(astlpc, "%s: Invalid mode: %d\n", __func__, mode); 1144 __mctp_free(astlpc); 1145 return NULL; 1146 } 1147 1148 return astlpc; 1149 } 1150 1151 struct mctp_binding *mctp_binding_astlpc_core(struct mctp_binding_astlpc *b) 1152 { 1153 return &b->binding; 1154 } 1155 1156 struct mctp_binding_astlpc * 1157 mctp_astlpc_init(uint8_t mode, uint32_t mtu, void *lpc_map, 1158 const struct mctp_binding_astlpc_ops *ops, void *ops_data) 1159 { 1160 struct mctp_binding_astlpc *astlpc; 1161 1162 if (!(mode == MCTP_BINDING_ASTLPC_MODE_BMC || 1163 mode == MCTP_BINDING_ASTLPC_MODE_HOST)) { 1164 mctp_prerr("Unknown binding mode: %u", mode); 1165 return NULL; 1166 } 1167 1168 astlpc = __mctp_astlpc_init(mode, mtu); 1169 if (!astlpc) 1170 return NULL; 1171 1172 memcpy(&astlpc->ops, ops, sizeof(astlpc->ops)); 1173 astlpc->ops_data = ops_data; 1174 astlpc->lpc_map = lpc_map; 1175 astlpc->mode = mode; 1176 1177 return astlpc; 1178 } 1179 1180 struct mctp_binding_astlpc * 1181 mctp_astlpc_init_ops(const struct mctp_binding_astlpc_ops *ops, void *ops_data, 1182 void *lpc_map) 1183 { 1184 return mctp_astlpc_init(MCTP_BINDING_ASTLPC_MODE_BMC, MCTP_BTU, lpc_map, 1185 ops, ops_data); 1186 } 1187 1188 void mctp_astlpc_destroy(struct mctp_binding_astlpc *astlpc) 1189 { 1190 /* Clear channel-active and bmc-ready */ 1191 if (astlpc->mode == MCTP_BINDING_ASTLPC_MODE_BMC) 1192 mctp_astlpc_kcs_set_status(astlpc, KCS_STATUS_OBF); 1193 __mctp_free(astlpc); 1194 } 1195 1196 #ifdef MCTP_HAVE_FILEIO 1197 1198 static int mctp_astlpc_init_fileio_lpc(struct mctp_binding_astlpc *astlpc) 1199 { 1200 struct aspeed_lpc_ctrl_mapping map = { 1201 .window_type = ASPEED_LPC_CTRL_WINDOW_MEMORY, 1202 .window_id = 0, /* There's only one */ 1203 .flags = 0, 1204 .addr = 0, 1205 .offset = 0, 1206 .size = 0 1207 }; 1208 void *lpc_map_base; 1209 int fd, rc; 1210 1211 fd = open(lpc_path, O_RDWR | O_SYNC); 1212 if (fd < 0) { 1213 astlpc_prwarn(astlpc, "LPC open (%s) failed", lpc_path); 1214 return -1; 1215 } 1216 1217 rc = ioctl(fd, ASPEED_LPC_CTRL_IOCTL_GET_SIZE, &map); 1218 if (rc) { 1219 astlpc_prwarn(astlpc, "LPC GET_SIZE failed"); 1220 close(fd); 1221 return -1; 1222 } 1223 1224 lpc_map_base = 1225 mmap(NULL, map.size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); 1226 if (lpc_map_base == MAP_FAILED) { 1227 astlpc_prwarn(astlpc, "LPC mmap failed"); 1228 rc = -1; 1229 } else { 1230 astlpc->lpc_map = lpc_map_base + map.size - LPC_WIN_SIZE; 1231 } 1232 1233 close(fd); 1234 1235 return rc; 1236 } 1237 1238 static int mctp_astlpc_init_fileio_kcs(struct mctp_binding_astlpc *astlpc) 1239 { 1240 astlpc->kcs_fd = open(kcs_path, O_RDWR); 1241 if (astlpc->kcs_fd < 0) 1242 return -1; 1243 1244 return 0; 1245 } 1246 1247 static int __mctp_astlpc_fileio_kcs_read(void *arg, 1248 enum mctp_binding_astlpc_kcs_reg reg, uint8_t *val) 1249 { 1250 struct mctp_binding_astlpc *astlpc = arg; 1251 off_t offset = reg; 1252 int rc; 1253 1254 rc = pread(astlpc->kcs_fd, val, 1, offset); 1255 1256 return rc == 1 ? 0 : -1; 1257 } 1258 1259 static int __mctp_astlpc_fileio_kcs_write(void *arg, 1260 enum mctp_binding_astlpc_kcs_reg reg, uint8_t val) 1261 { 1262 struct mctp_binding_astlpc *astlpc = arg; 1263 off_t offset = reg; 1264 int rc; 1265 1266 rc = pwrite(astlpc->kcs_fd, &val, 1, offset); 1267 1268 return rc == 1 ? 0 : -1; 1269 } 1270 1271 int mctp_astlpc_get_fd(struct mctp_binding_astlpc *astlpc) 1272 { 1273 return astlpc->kcs_fd; 1274 } 1275 1276 struct mctp_binding_astlpc *mctp_astlpc_init_fileio(void) 1277 { 1278 struct mctp_binding_astlpc *astlpc; 1279 int rc; 1280 1281 /* 1282 * If we're doing file IO then we're very likely not running 1283 * freestanding, so lets assume that we're on the BMC side. 1284 * 1285 * Requesting an MTU of 0 requests the largest possible MTU, whatever 1286 * value that might take. 1287 */ 1288 astlpc = __mctp_astlpc_init(MCTP_BINDING_ASTLPC_MODE_BMC, 0); 1289 if (!astlpc) 1290 return NULL; 1291 1292 /* Set internal operations for kcs. We use direct accesses to the lpc 1293 * map area */ 1294 astlpc->ops.kcs_read = __mctp_astlpc_fileio_kcs_read; 1295 astlpc->ops.kcs_write = __mctp_astlpc_fileio_kcs_write; 1296 astlpc->ops_data = astlpc; 1297 1298 rc = mctp_astlpc_init_fileio_lpc(astlpc); 1299 if (rc) { 1300 free(astlpc); 1301 return NULL; 1302 } 1303 1304 rc = mctp_astlpc_init_fileio_kcs(astlpc); 1305 if (rc) { 1306 free(astlpc); 1307 return NULL; 1308 } 1309 1310 return astlpc; 1311 } 1312 #else 1313 struct mctp_binding_astlpc * __attribute__((const)) 1314 mctp_astlpc_init_fileio(void) 1315 { 1316 astlpc_prerr(astlpc, "Missing support for file IO"); 1317 return NULL; 1318 } 1319 1320 int __attribute__((const)) mctp_astlpc_get_fd( 1321 struct mctp_binding_astlpc *astlpc __attribute__((unused))) 1322 { 1323 astlpc_prerr(astlpc, "Missing support for file IO"); 1324 return -1; 1325 } 1326 #endif 1327