tpm.c revision 1.19.6.1
1 /* $NetBSD: tpm.c,v 1.19.6.1 2021/05/31 22:15:18 cjep Exp $ */ 2 3 /* 4 * Copyright (c) 2019 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Maxime Villard. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * Copyright (c) 2008, 2009 Michael Shalayeff 34 * Copyright (c) 2009, 2010 Hans-Joerg Hoexer 35 * All rights reserved. 36 * 37 * Permission to use, copy, modify, and distribute this software for any 38 * purpose with or without fee is hereby granted, provided that the above 39 * copyright notice and this permission notice appear in all copies. 40 * 41 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 42 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 43 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 44 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 45 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER IN 46 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 47 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 48 */ 49 50 #include <sys/cdefs.h> 51 __KERNEL_RCSID(0, "$NetBSD: tpm.c,v 1.19.6.1 2021/05/31 22:15:18 cjep Exp $"); 52 53 #include <sys/param.h> 54 #include <sys/types.h> 55 56 #include <sys/atomic.h> 57 #include <sys/bus.h> 58 #include <sys/conf.h> 59 #include <sys/device.h> 60 #include <sys/kernel.h> 61 #include <sys/malloc.h> 62 #include <sys/pmf.h> 63 #include <sys/proc.h> 64 #include <sys/systm.h> 65 #include <sys/workqueue.h> 66 67 #include <dev/ic/tpmreg.h> 68 #include <dev/ic/tpmvar.h> 69 70 #include "ioconf.h" 71 72 CTASSERT(sizeof(struct tpm_header) == 10); 73 74 #define TPM_BUFSIZ 1024 75 76 #define TPM_PARAM_SIZE 0x0001 /* that's a flag */ 77 78 /* Timeouts. */ 79 #define TPM_ACCESS_TMO 2000 /* 2sec */ 80 #define TPM_READY_TMO 2000 /* 2sec */ 81 #define TPM_READ_TMO 2000 /* 2sec */ 82 #define TPM_BURST_TMO 2000 /* 2sec */ 83 84 #define TPM_CAPS_REQUIRED \ 85 (TPM_INTF_DATA_AVAIL_INT|TPM_INTF_LOCALITY_CHANGE_INT| \ 86 TPM_INTF_INT_LEVEL_LOW) 87 88 static inline int 89 tpm_tmotohz(int tmo) 90 { 91 struct timeval tv; 92 93 tv.tv_sec = tmo / 1000; 94 tv.tv_usec = 1000 * (tmo % 1000); 95 96 return tvtohz(&tv); 97 } 98 99 static int 100 tpm_getburst(struct tpm_softc *sc) 101 { 102 int burst, to, rv; 103 104 to = tpm_tmotohz(TPM_BURST_TMO); 105 106 while (to--) { 107 /* 108 * Burst count is in bits 23:8, so read the two higher bytes. 109 */ 110 burst = bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_STS + 1); 111 burst |= bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_STS + 2) 112 << 8; 113 114 if (burst) 115 return burst; 116 117 rv = tsleep(sc, PCATCH, "tpm_getburst", 1); 118 if (rv && rv != EWOULDBLOCK) { 119 return 0; 120 } 121 } 122 123 return 0; 124 } 125 126 static inline uint8_t 127 tpm_status(struct tpm_softc *sc) 128 { 129 return bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_STS) & 130 TPM_STS_STATUS_BITS; 131 } 132 133 /* -------------------------------------------------------------------------- */ 134 135 static bool 136 tpm12_suspend(struct tpm_softc *sc) 137 { 138 static const uint8_t command[10] = { 139 0x00, 0xC1, /* TPM_TAG_RQU_COMMAND */ 140 0x00, 0x00, 0x00, 10, /* Length in bytes */ 141 0x00, 0x00, 0x00, 0x98 /* TPM_ORD_SaveState */ 142 }; 143 struct tpm_header response; 144 145 if ((*sc->sc_intf->write)(sc, &command, sizeof(command)) != 0) 146 return false; 147 if ((*sc->sc_intf->read)(sc, &response, sizeof(response), NULL, 0) != 0) 148 return false; 149 if (TPM_BE32(response.code) != 0) 150 return false; 151 152 return true; 153 } 154 155 static bool 156 tpm20_suspend(struct tpm_softc *sc) 157 { 158 static const uint8_t command[12] = { 159 0x80, 0x01, /* TPM_ST_NO_SESSIONS */ 160 0x00, 0x00, 0x00, 12, /* Length in bytes */ 161 0x00, 0x00, 0x01, 0x45, /* TPM_CC_Shutdown */ 162 0x00, 0x01 /* TPM_SU_STATE */ 163 }; 164 struct tpm_header response; 165 166 if ((*sc->sc_intf->write)(sc, &command, sizeof(command)) != 0) 167 return false; 168 if ((*sc->sc_intf->read)(sc, &response, sizeof(response), NULL, 0) != 0) 169 return false; 170 if (TPM_BE32(response.code) != 0) 171 return false; 172 173 return true; 174 } 175 176 bool 177 tpm_suspend(device_t dev, const pmf_qual_t *qual) 178 { 179 struct tpm_softc *sc = device_private(dev); 180 181 switch (sc->sc_ver) { 182 case TPM_1_2: 183 return tpm12_suspend(sc); 184 case TPM_2_0: 185 return tpm20_suspend(sc); 186 default: 187 panic("%s: impossible", __func__); 188 } 189 } 190 191 bool 192 tpm_resume(device_t dev, const pmf_qual_t *qual) 193 { 194 /* 195 * Don't do anything, the BIOS is supposed to restore the previously 196 * saved state. 197 */ 198 return true; 199 } 200 201 /* -------------------------------------------------------------------------- */ 202 203 static int 204 tpm_poll(struct tpm_softc *sc, uint8_t mask, int to, wchan_t chan) 205 { 206 int rv; 207 208 while (((sc->sc_status = tpm_status(sc)) & mask) != mask && to--) { 209 rv = tsleep(chan, PCATCH, "tpm_poll", 1); 210 if (rv && rv != EWOULDBLOCK) { 211 return rv; 212 } 213 } 214 215 return 0; 216 } 217 218 static int 219 tpm_waitfor(struct tpm_softc *sc, uint8_t bits, int tmo, wchan_t chan) 220 { 221 int retry, to, rv; 222 uint8_t todo; 223 224 to = tpm_tmotohz(tmo); 225 retry = 3; 226 227 restart: 228 todo = bits; 229 230 /* 231 * TPM_STS_VALID has priority over the others. 232 */ 233 if (todo & TPM_STS_VALID) { 234 if ((rv = tpm_poll(sc, TPM_STS_VALID, to+1, chan)) != 0) 235 return rv; 236 todo &= ~TPM_STS_VALID; 237 } 238 239 if ((rv = tpm_poll(sc, todo, to, chan)) != 0) 240 return rv; 241 242 if ((todo & sc->sc_status) != todo) { 243 if ((retry-- > 0) && (bits & TPM_STS_VALID)) { 244 bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_STS, 245 TPM_STS_RESP_RETRY); 246 goto restart; 247 } 248 return EIO; 249 } 250 251 return 0; 252 } 253 254 /* -------------------------------------------------------------------------- */ 255 256 /* 257 * TPM using the TIS 1.2 interface. 258 */ 259 260 static int 261 tpm12_request_locality(struct tpm_softc *sc, int l) 262 { 263 uint32_t r; 264 int to, rv; 265 266 if (l != 0) 267 return EINVAL; 268 269 if ((bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_ACCESS) & 270 (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) == 271 (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) 272 return 0; 273 274 bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_ACCESS, 275 TPM_ACCESS_REQUEST_USE); 276 277 to = tpm_tmotohz(TPM_ACCESS_TMO); 278 279 while ((r = bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_ACCESS) & 280 (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) != 281 (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY) && to--) { 282 rv = tsleep(sc->sc_intf->init, PCATCH, "tpm_locality", 1); 283 if (rv && rv != EWOULDBLOCK) { 284 return rv; 285 } 286 } 287 288 if ((r & (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) != 289 (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) { 290 return EBUSY; 291 } 292 293 return 0; 294 } 295 296 static int 297 tpm_tis12_probe(bus_space_tag_t bt, bus_space_handle_t bh) 298 { 299 uint32_t cap; 300 uint8_t reg; 301 int tmo; 302 303 cap = bus_space_read_4(bt, bh, TPM_INTF_CAPABILITY); 304 if (cap == 0xffffffff) 305 return EINVAL; 306 if ((cap & TPM_CAPS_REQUIRED) != TPM_CAPS_REQUIRED) 307 return ENOTSUP; 308 309 /* Request locality 0. */ 310 bus_space_write_1(bt, bh, TPM_ACCESS, TPM_ACCESS_REQUEST_USE); 311 312 /* Wait for it to become active. */ 313 tmo = TPM_ACCESS_TMO; /* Milliseconds. */ 314 while ((reg = bus_space_read_1(bt, bh, TPM_ACCESS) & 315 (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) != 316 (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY) && tmo--) { 317 DELAY(1000); /* 1 millisecond. */ 318 } 319 if ((reg & (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) != 320 (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) { 321 return ETIMEDOUT; 322 } 323 324 if (bus_space_read_4(bt, bh, TPM_ID) == 0xffffffff) 325 return EINVAL; 326 327 return 0; 328 } 329 330 static int 331 tpm12_rng(struct tpm_softc *sc, unsigned *entropybitsp) 332 { 333 /* 334 * TPM Specification Version 1.2, Main Part 3: Commands, 335 * Sec. 13.6 TPM_GetRandom 336 */ 337 struct { 338 struct tpm_header hdr; 339 uint32_t bytesRequested; 340 } __packed command; 341 struct response { 342 struct tpm_header hdr; 343 uint32_t randomBytesSize; 344 uint8_t bytes[64]; 345 } __packed response; 346 bool endwrite = false, endread = false; 347 size_t nread; 348 uint16_t tag; 349 uint32_t pktlen, code, nbytes, entropybits = 0; 350 int rv; 351 352 /* Encode the command. */ 353 memset(&command, 0, sizeof(command)); 354 command.hdr.tag = htobe16(TPM_TAG_RQU_COMMAND); 355 command.hdr.length = htobe32(sizeof(command)); 356 command.hdr.code = htobe32(TPM_ORD_GetRandom); 357 command.bytesRequested = htobe32(sizeof(response.bytes)); 358 359 /* Write the command. */ 360 if ((rv = (*sc->sc_intf->start)(sc, UIO_WRITE)) != 0) { 361 device_printf(sc->sc_dev, "start write failed, error=%d\n", 362 rv); 363 goto out; 364 } 365 endwrite = true; 366 if ((rv = (*sc->sc_intf->write)(sc, &command, sizeof(command))) != 0) { 367 device_printf(sc->sc_dev, "write failed, error=%d\n", rv); 368 goto out; 369 } 370 rv = (*sc->sc_intf->end)(sc, UIO_WRITE, 0); 371 endwrite = false; 372 if (rv) { 373 device_printf(sc->sc_dev, "end write failed, error=%d\n", rv); 374 goto out; 375 } 376 377 /* Read the response header. */ 378 if ((rv = (*sc->sc_intf->start)(sc, UIO_READ)) != 0) { 379 device_printf(sc->sc_dev, "start write failed, error=%d\n", 380 rv); 381 goto out; 382 } 383 endread = true; 384 if ((rv = (*sc->sc_intf->read)(sc, &response.hdr, sizeof(response.hdr), 385 &nread, 0)) != 0) { 386 device_printf(sc->sc_dev, "read failed, error=%d\n", rv); 387 goto out; 388 } 389 390 /* Verify the response header looks sensible. */ 391 if (nread != sizeof(response.hdr)) { 392 device_printf(sc->sc_dev, "read %zu bytes, expected %zu", 393 nread, sizeof(response.hdr)); 394 goto out; 395 } 396 tag = be16toh(response.hdr.tag); 397 pktlen = be32toh(response.hdr.length); 398 code = be32toh(response.hdr.code); 399 if (tag != TPM_TAG_RSP_COMMAND || 400 pktlen < offsetof(struct response, bytes) || 401 pktlen > sizeof(response) || 402 code != 0) { 403 /* 404 * If the tpm itself is busy (e.g., it has yet to run a 405 * self-test, or it's in a timeout period to defend 406 * against brute force attacks), then we can try again 407 * later. Otherwise, give up. 408 */ 409 if (code & TPM_NON_FATAL) { 410 aprint_debug_dev(sc->sc_dev, "%s: tpm busy, code=%u\n", 411 __func__, code & ~TPM_NON_FATAL); 412 rv = 0; 413 } else if (code == TPM_DEACTIVATED) { 414 device_printf(sc->sc_dev, "tpm is deactivated\n"); 415 rv = ENXIO; 416 } else { 417 device_printf(sc->sc_dev, "bad tpm response:" 418 " tag=%u len=%u code=%u\n", tag, pktlen, code); 419 hexdump(aprint_debug, "tpm response header", 420 (const void *)&response.hdr, 421 sizeof(response.hdr)); 422 rv = EIO; 423 } 424 goto out; 425 } 426 427 /* Read the response payload. */ 428 if ((rv = (*sc->sc_intf->read)(sc, 429 (char *)&response + nread, pktlen - nread, 430 NULL, TPM_PARAM_SIZE)) != 0) { 431 device_printf(sc->sc_dev, "read failed, error=%d\n", rv); 432 goto out; 433 } 434 endread = false; 435 if ((rv = (*sc->sc_intf->end)(sc, UIO_READ, 0)) != 0) { 436 device_printf(sc->sc_dev, "end read failed, error=%d\n", rv); 437 goto out; 438 } 439 440 /* Verify the number of bytes read looks sensible. */ 441 nbytes = be32toh(response.randomBytesSize); 442 if (nbytes > pktlen - offsetof(struct response, bytes)) { 443 device_printf(sc->sc_dev, "overlong GetRandom length:" 444 " %u, max %zu\n", 445 nbytes, pktlen - offsetof(struct response, bytes)); 446 nbytes = pktlen - offsetof(struct response, bytes); 447 } 448 449 /* 450 * Enter the data into the entropy pool. Conservatively (or, 451 * perhaps, cargocultily) estimate half a bit of entropy per 452 * bit of data. 453 */ 454 CTASSERT(sizeof(response.bytes) <= UINT_MAX/(NBBY/2)); 455 entropybits = (NBBY/2)*nbytes; 456 rnd_add_data(&sc->sc_rnd, response.bytes, nbytes, entropybits); 457 458 out: /* End the read or write if still ongoing. */ 459 if (endread) 460 rv = (*sc->sc_intf->end)(sc, UIO_READ, rv); 461 if (endwrite) 462 rv = (*sc->sc_intf->end)(sc, UIO_WRITE, rv); 463 464 *entropybitsp = entropybits; 465 return rv; 466 } 467 468 static int 469 tpm20_rng(struct tpm_softc *sc, unsigned *entropybitsp) 470 { 471 /* 472 * Trusted Platform Module Library, Family "2.0", Level 00 473 * Revision 01.38, Part 3: Commands, Sec. 16.1 `TPM2_GetRandom' 474 * 475 * https://trustedcomputinggroup.org/wp-content/uploads/TPM-Rev-2.0-Part-3-Commands-01.38.pdf#page=133 476 */ 477 struct { 478 struct tpm_header hdr; 479 uint16_t bytesRequested; 480 } __packed command; 481 struct response { 482 struct tpm_header hdr; 483 uint16_t randomBytesSize; 484 uint8_t bytes[64]; 485 } __packed response; 486 bool endwrite = false, endread = false; 487 size_t nread; 488 uint16_t tag; 489 uint32_t pktlen, code, nbytes, entropybits = 0; 490 int rv; 491 492 /* Encode the command. */ 493 memset(&command, 0, sizeof(command)); 494 command.hdr.tag = htobe16(TPM2_ST_NO_SESSIONS); 495 command.hdr.length = htobe32(sizeof(command)); 496 command.hdr.code = htobe32(TPM2_CC_GetRandom); 497 command.bytesRequested = htobe16(sizeof(response.bytes)); 498 499 /* Write the command. */ 500 if ((rv = (*sc->sc_intf->start)(sc, UIO_WRITE)) != 0) { 501 device_printf(sc->sc_dev, "start write failed, error=%d\n", 502 rv); 503 goto out; 504 } 505 endwrite = true; 506 if ((rv = (*sc->sc_intf->write)(sc, &command, sizeof(command))) != 0) { 507 device_printf(sc->sc_dev, "write failed, error=%d\n", rv); 508 goto out; 509 } 510 rv = (*sc->sc_intf->end)(sc, UIO_WRITE, 0); 511 endwrite = false; 512 if (rv) { 513 device_printf(sc->sc_dev, "end write failed, error=%d\n", rv); 514 goto out; 515 } 516 517 /* Read the response header. */ 518 if ((rv = (*sc->sc_intf->start)(sc, UIO_READ)) != 0) { 519 device_printf(sc->sc_dev, "start write failed, error=%d\n", 520 rv); 521 goto out; 522 } 523 endread = true; 524 if ((rv = (*sc->sc_intf->read)(sc, &response.hdr, sizeof(response.hdr), 525 &nread, 0)) != 0) { 526 device_printf(sc->sc_dev, "read failed, error=%d\n", rv); 527 goto out; 528 } 529 530 /* Verify the response header looks sensible. */ 531 if (nread != sizeof(response.hdr)) { 532 device_printf(sc->sc_dev, "read %zu bytes, expected %zu", 533 nread, sizeof(response.hdr)); 534 goto out; 535 } 536 tag = be16toh(response.hdr.tag); 537 pktlen = be32toh(response.hdr.length); 538 code = be32toh(response.hdr.code); 539 if (tag != TPM2_ST_NO_SESSIONS || 540 pktlen < offsetof(struct response, bytes) || 541 pktlen > sizeof(response) || 542 code != 0) { 543 /* 544 * If the tpm itself is busy (e.g., it has yet to run a 545 * self-test, or it's in a timeout period to defend 546 * against brute force attacks), then we can try again 547 * later. Otherwise, give up. 548 */ 549 if (code & TPM2_RC_WARN) { 550 aprint_debug_dev(sc->sc_dev, "%s: tpm busy," 551 " code=TPM_RC_WARN+0x%x\n", 552 __func__, code & ~TPM2_RC_WARN); 553 rv = 0; 554 } else { 555 device_printf(sc->sc_dev, "bad tpm response:" 556 " tag=%u len=%u code=0x%x\n", tag, pktlen, code); 557 hexdump(aprint_debug, "tpm response header", 558 (const void *)&response.hdr, 559 sizeof(response.hdr)); 560 rv = EIO; 561 } 562 goto out; 563 } 564 565 /* Read the response payload. */ 566 if ((rv = (*sc->sc_intf->read)(sc, 567 (char *)&response + nread, pktlen - nread, 568 NULL, TPM_PARAM_SIZE)) != 0) { 569 device_printf(sc->sc_dev, "read failed, error=%d\n", rv); 570 goto out; 571 } 572 endread = false; 573 if ((rv = (*sc->sc_intf->end)(sc, UIO_READ, 0)) != 0) { 574 device_printf(sc->sc_dev, "end read failed, error=%d\n", rv); 575 goto out; 576 } 577 578 /* Verify the number of bytes read looks sensible. */ 579 nbytes = be16toh(response.randomBytesSize); 580 if (nbytes > pktlen - offsetof(struct response, bytes)) { 581 device_printf(sc->sc_dev, "overlong GetRandom length:" 582 " %u, max %zu\n", 583 nbytes, pktlen - offsetof(struct response, bytes)); 584 nbytes = pktlen - offsetof(struct response, bytes); 585 } 586 587 /* 588 * Enter the data into the entropy pool. Conservatively (or, 589 * perhaps, cargocultily) estimate half a bit of entropy per 590 * bit of data. 591 */ 592 CTASSERT(sizeof(response.bytes) <= UINT_MAX/(NBBY/2)); 593 entropybits = (NBBY/2)*nbytes; 594 rnd_add_data(&sc->sc_rnd, response.bytes, nbytes, entropybits); 595 596 out: /* End the read or write if still ongoing. */ 597 if (endread) 598 rv = (*sc->sc_intf->end)(sc, UIO_READ, rv); 599 if (endwrite) 600 rv = (*sc->sc_intf->end)(sc, UIO_WRITE, rv); 601 602 *entropybitsp = entropybits; 603 return rv; 604 } 605 606 static void 607 tpm_rng_work(struct work *wk, void *cookie) 608 { 609 struct tpm_softc *sc = cookie; 610 unsigned nbytes, entropybits; 611 bool busy; 612 int rv; 613 614 /* Acknowledge the request. */ 615 nbytes = atomic_swap_uint(&sc->sc_rndpending, 0); 616 617 /* Lock userland out of the tpm, or fail if it's already open. */ 618 mutex_enter(&sc->sc_lock); 619 busy = sc->sc_busy; 620 sc->sc_busy = true; 621 mutex_exit(&sc->sc_lock); 622 if (busy) { /* tough */ 623 aprint_debug_dev(sc->sc_dev, "%s: device in use\n", __func__); 624 return; 625 } 626 627 /* 628 * Issue as many commands as needed to fulfill the request, but 629 * stop if anything fails. 630 */ 631 for (; nbytes; nbytes -= MIN(nbytes, MAX(1, entropybits/NBBY))) { 632 switch (sc->sc_ver) { 633 case TPM_1_2: 634 rv = tpm12_rng(sc, &entropybits); 635 break; 636 case TPM_2_0: 637 rv = tpm20_rng(sc, &entropybits); 638 break; 639 default: 640 panic("bad tpm version: %d", sc->sc_ver); 641 } 642 if (rv) 643 break; 644 } 645 646 /* 647 * If the tpm is busted, no sense in trying again -- most 648 * likely, it is deactivated, and by the spec it cannot be 649 * reactivated until after a reboot. 650 */ 651 if (rv) { 652 device_printf(sc->sc_dev, "deactivating entropy source\n"); 653 rnd_detach_source(&sc->sc_rnd); 654 /* XXX worker thread can't workqueue_destroy its own queue */ 655 } 656 657 /* Relinquish the tpm back to userland. */ 658 mutex_enter(&sc->sc_lock); 659 KASSERT(sc->sc_busy); 660 sc->sc_busy = false; 661 mutex_exit(&sc->sc_lock); 662 } 663 664 static void 665 tpm_rng_get(size_t nbytes, void *cookie) 666 { 667 struct tpm_softc *sc = cookie; 668 669 if (atomic_swap_uint(&sc->sc_rndpending, MIN(nbytes, UINT_MAX/NBBY)) 670 == 0) 671 workqueue_enqueue(sc->sc_rndwq, &sc->sc_rndwk, NULL); 672 } 673 674 static int 675 tpm_tis12_init(struct tpm_softc *sc) 676 { 677 int rv; 678 679 sc->sc_caps = bus_space_read_4(sc->sc_bt, sc->sc_bh, 680 TPM_INTF_CAPABILITY); 681 sc->sc_devid = bus_space_read_4(sc->sc_bt, sc->sc_bh, TPM_ID); 682 sc->sc_rev = bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_REV); 683 684 aprint_normal_dev(sc->sc_dev, "device 0x%08x rev 0x%x\n", 685 sc->sc_devid, sc->sc_rev); 686 687 if ((rv = tpm12_request_locality(sc, 0)) != 0) 688 return rv; 689 690 /* Abort whatever it thought it was doing. */ 691 bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_STS, TPM_STS_CMD_READY); 692 693 /* XXX Run this at higher priority? */ 694 if ((rv = workqueue_create(&sc->sc_rndwq, device_xname(sc->sc_dev), 695 tpm_rng_work, sc, PRI_NONE, IPL_VM, WQ_MPSAFE)) != 0) 696 return rv; 697 rndsource_setcb(&sc->sc_rnd, tpm_rng_get, sc); 698 rnd_attach_source(&sc->sc_rnd, device_xname(sc->sc_dev), 699 RND_TYPE_RNG, 700 RND_FLAG_COLLECT_VALUE|RND_FLAG_ESTIMATE_VALUE|RND_FLAG_HASCB); 701 702 return 0; 703 } 704 705 static int 706 tpm_tis12_start(struct tpm_softc *sc, int rw) 707 { 708 int rv; 709 710 if (rw == UIO_READ) { 711 rv = tpm_waitfor(sc, TPM_STS_DATA_AVAIL | TPM_STS_VALID, 712 TPM_READ_TMO, sc->sc_intf->read); 713 return rv; 714 } 715 716 /* Request the 0th locality. */ 717 if ((rv = tpm12_request_locality(sc, 0)) != 0) 718 return rv; 719 720 sc->sc_status = tpm_status(sc); 721 if (sc->sc_status & TPM_STS_CMD_READY) 722 return 0; 723 724 /* Abort previous and restart. */ 725 bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_STS, TPM_STS_CMD_READY); 726 rv = tpm_waitfor(sc, TPM_STS_CMD_READY, TPM_READY_TMO, sc->sc_intf->write); 727 if (rv) 728 return rv; 729 730 return 0; 731 } 732 733 static int 734 tpm_tis12_read(struct tpm_softc *sc, void *buf, size_t len, size_t *count, 735 int flags) 736 { 737 uint8_t *p = buf; 738 size_t cnt; 739 int rv, n; 740 741 cnt = 0; 742 while (len > 0) { 743 rv = tpm_waitfor(sc, TPM_STS_DATA_AVAIL | TPM_STS_VALID, 744 TPM_READ_TMO, sc->sc_intf->read); 745 if (rv) 746 return rv; 747 748 n = MIN(len, tpm_getburst(sc)); 749 while (n > 0) { 750 *p++ = bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_DATA); 751 cnt++; 752 len--; 753 n--; 754 } 755 756 if ((flags & TPM_PARAM_SIZE) == 0 && cnt >= 6) 757 break; 758 } 759 760 if (count) 761 *count = cnt; 762 763 return 0; 764 } 765 766 static int 767 tpm_tis12_write(struct tpm_softc *sc, const void *buf, size_t len) 768 { 769 const uint8_t *p = buf; 770 size_t cnt; 771 int rv, r; 772 773 if (len == 0) 774 return 0; 775 if ((rv = tpm12_request_locality(sc, 0)) != 0) 776 return rv; 777 778 cnt = 0; 779 while (cnt < len - 1) { 780 for (r = tpm_getburst(sc); r > 0 && cnt < len - 1; r--) { 781 bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_DATA, *p++); 782 cnt++; 783 } 784 if ((rv = tpm_waitfor(sc, TPM_STS_VALID, TPM_READ_TMO, sc))) { 785 return rv; 786 } 787 sc->sc_status = tpm_status(sc); 788 if (!(sc->sc_status & TPM_STS_DATA_EXPECT)) { 789 return EIO; 790 } 791 } 792 793 bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_DATA, *p++); 794 cnt++; 795 796 if ((rv = tpm_waitfor(sc, TPM_STS_VALID, TPM_READ_TMO, sc))) { 797 return rv; 798 } 799 if ((sc->sc_status & TPM_STS_DATA_EXPECT) != 0) { 800 return EIO; 801 } 802 803 return 0; 804 } 805 806 static int 807 tpm_tis12_end(struct tpm_softc *sc, int rw, int err) 808 { 809 int rv = 0; 810 811 if (rw == UIO_READ) { 812 rv = tpm_waitfor(sc, TPM_STS_VALID, TPM_READ_TMO, sc->sc_intf->read); 813 if (rv) 814 return rv; 815 816 /* Still more data? */ 817 sc->sc_status = tpm_status(sc); 818 if (!err && (sc->sc_status & TPM_STS_DATA_AVAIL)) { 819 rv = EIO; 820 } 821 822 bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_STS, 823 TPM_STS_CMD_READY); 824 825 /* Release the 0th locality. */ 826 bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_ACCESS, 827 TPM_ACCESS_ACTIVE_LOCALITY); 828 } else { 829 /* Hungry for more? */ 830 sc->sc_status = tpm_status(sc); 831 if (!err && (sc->sc_status & TPM_STS_DATA_EXPECT)) { 832 rv = EIO; 833 } 834 835 bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_STS, 836 err ? TPM_STS_CMD_READY : TPM_STS_GO); 837 } 838 839 return rv; 840 } 841 842 const struct tpm_intf tpm_intf_tis12 = { 843 .version = TIS_1_2, 844 .probe = tpm_tis12_probe, 845 .init = tpm_tis12_init, 846 .start = tpm_tis12_start, 847 .read = tpm_tis12_read, 848 .write = tpm_tis12_write, 849 .end = tpm_tis12_end 850 }; 851 852 /* -------------------------------------------------------------------------- */ 853 854 static dev_type_open(tpmopen); 855 static dev_type_close(tpmclose); 856 static dev_type_read(tpmread); 857 static dev_type_write(tpmwrite); 858 static dev_type_ioctl(tpmioctl); 859 860 const struct cdevsw tpm_cdevsw = { 861 .d_open = tpmopen, 862 .d_close = tpmclose, 863 .d_read = tpmread, 864 .d_write = tpmwrite, 865 .d_ioctl = tpmioctl, 866 .d_stop = nostop, 867 .d_tty = notty, 868 .d_poll = nopoll, 869 .d_mmap = nommap, 870 .d_kqfilter = nokqfilter, 871 .d_discard = nodiscard, 872 .d_flag = D_OTHER | D_MPSAFE, 873 }; 874 875 static int 876 tpmopen(dev_t dev, int flag, int mode, struct lwp *l) 877 { 878 struct tpm_softc *sc = device_lookup_private(&tpm_cd, minor(dev)); 879 int ret = 0; 880 881 if (sc == NULL) 882 return ENXIO; 883 884 mutex_enter(&sc->sc_lock); 885 if (sc->sc_busy) { 886 ret = EBUSY; 887 } else { 888 sc->sc_busy = true; 889 } 890 mutex_exit(&sc->sc_lock); 891 892 return ret; 893 } 894 895 static int 896 tpmclose(dev_t dev, int flag, int mode, struct lwp *l) 897 { 898 struct tpm_softc *sc = device_lookup_private(&tpm_cd, minor(dev)); 899 int ret = 0; 900 901 if (sc == NULL) 902 return ENXIO; 903 904 mutex_enter(&sc->sc_lock); 905 if (!sc->sc_busy) { 906 ret = EINVAL; 907 } else { 908 sc->sc_busy = false; 909 } 910 mutex_exit(&sc->sc_lock); 911 912 return ret; 913 } 914 915 static int 916 tpmread(dev_t dev, struct uio *uio, int flags) 917 { 918 struct tpm_softc *sc = device_lookup_private(&tpm_cd, minor(dev)); 919 struct tpm_header hdr; 920 uint8_t buf[TPM_BUFSIZ]; 921 size_t cnt, len, n; 922 int rv; 923 924 if (sc == NULL) 925 return ENXIO; 926 927 if ((rv = (*sc->sc_intf->start)(sc, UIO_READ))) 928 return rv; 929 930 /* Get the header. */ 931 if ((rv = (*sc->sc_intf->read)(sc, &hdr, sizeof(hdr), &cnt, 0))) { 932 goto out; 933 } 934 len = TPM_BE32(hdr.length); 935 if (len > uio->uio_resid || len < cnt) { 936 rv = EIO; 937 goto out; 938 } 939 940 /* Copy out the header. */ 941 if ((rv = uiomove(&hdr, cnt, uio))) { 942 goto out; 943 } 944 945 /* Process the rest. */ 946 len -= cnt; 947 while (len > 0) { 948 n = MIN(sizeof(buf), len); 949 if ((rv = (*sc->sc_intf->read)(sc, buf, n, NULL, TPM_PARAM_SIZE))) { 950 goto out; 951 } 952 if ((rv = uiomove(buf, n, uio))) { 953 goto out; 954 } 955 len -= n; 956 } 957 958 out: 959 rv = (*sc->sc_intf->end)(sc, UIO_READ, rv); 960 return rv; 961 } 962 963 static int 964 tpmwrite(dev_t dev, struct uio *uio, int flags) 965 { 966 struct tpm_softc *sc = device_lookup_private(&tpm_cd, minor(dev)); 967 uint8_t buf[TPM_BUFSIZ]; 968 int n, rv; 969 970 if (sc == NULL) 971 return ENXIO; 972 973 n = MIN(sizeof(buf), uio->uio_resid); 974 if ((rv = uiomove(buf, n, uio))) { 975 goto out; 976 } 977 if ((rv = (*sc->sc_intf->start)(sc, UIO_WRITE))) { 978 goto out; 979 } 980 if ((rv = (*sc->sc_intf->write)(sc, buf, n))) { 981 goto out; 982 } 983 984 rv = (*sc->sc_intf->end)(sc, UIO_WRITE, rv); 985 out: 986 return rv; 987 } 988 989 static int 990 tpmioctl(dev_t dev, u_long cmd, void *addr, int flag, struct lwp *l) 991 { 992 struct tpm_softc *sc = device_lookup_private(&tpm_cd, minor(dev)); 993 struct tpm_ioc_getinfo *info; 994 995 if (sc == NULL) 996 return ENXIO; 997 998 switch (cmd) { 999 case TPM_IOC_GETINFO: 1000 info = addr; 1001 info->api_version = TPM_API_VERSION; 1002 info->tpm_version = sc->sc_ver; 1003 info->itf_version = sc->sc_intf->version; 1004 info->device_id = sc->sc_devid; 1005 info->device_rev = sc->sc_rev; 1006 info->device_caps = sc->sc_caps; 1007 return 0; 1008 default: 1009 break; 1010 } 1011 1012 return ENOTTY; 1013 } 1014
Indexes created Thu Oct 02 07:10:07 GMT 2025