1 /* 2 * tpm_tis_i2c.c - QEMU's TPM TIS I2C Device 3 * 4 * Copyright (c) 2023 IBM Corporation 5 * 6 * Authors: 7 * Ninad Palsule <ninad@linux.ibm.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or later. 10 * See the COPYING file in the top-level directory. 11 * 12 * TPM I2C implementation follows TCG TPM I2c Interface specification, 13 * Family 2.0, Level 00, Revision 1.00 14 * 15 * TPM TIS for TPM 2 implementation following TCG PC Client Platform 16 * TPM Profile (PTP) Specification, Familiy 2.0, Revision 00.43 17 * 18 */ 19 20 #include "qemu/osdep.h" 21 #include "hw/i2c/i2c.h" 22 #include "hw/sysbus.h" 23 #include "hw/acpi/tpm.h" 24 #include "migration/vmstate.h" 25 #include "tpm_prop.h" 26 #include "qemu/log.h" 27 #include "trace.h" 28 #include "tpm_tis.h" 29 30 /* Operations */ 31 #define OP_SEND 1 32 #define OP_RECV 2 33 34 /* Is locality valid */ 35 #define TPM_TIS_I2C_IS_VALID_LOCTY(x) TPM_TIS_IS_VALID_LOCTY(x) 36 37 typedef struct TPMStateI2C { 38 /*< private >*/ 39 I2CSlave parent_obj; 40 41 uint8_t offset; /* offset into data[] */ 42 uint8_t operation; /* OP_SEND & OP_RECV */ 43 uint8_t data[5]; /* Data */ 44 45 /* i2c registers */ 46 uint8_t loc_sel; /* Current locality */ 47 uint8_t csum_enable; /* Is checksum enabled */ 48 49 /* Derived from the above */ 50 const char *reg_name; /* Register name */ 51 uint32_t tis_addr; /* Converted tis address including locty */ 52 53 /*< public >*/ 54 TPMState state; /* not a QOM object */ 55 56 } TPMStateI2C; 57 58 DECLARE_INSTANCE_CHECKER(TPMStateI2C, TPM_TIS_I2C, 59 TYPE_TPM_TIS_I2C) 60 61 /* Prototype */ 62 static inline void tpm_tis_i2c_to_tis_reg(TPMStateI2C *i2cst, uint8_t i2c_reg); 63 64 /* Register map */ 65 typedef struct regMap { 66 uint8_t i2c_reg; /* I2C register */ 67 uint16_t tis_reg; /* TIS register */ 68 const char *reg_name; /* Register name */ 69 } I2CRegMap; 70 71 /* 72 * The register values in the common code is different than the latest 73 * register numbers as per the spec hence add the conversion map 74 */ 75 static const I2CRegMap tpm_tis_reg_map[] = { 76 /* 77 * These registers are sent to TIS layer. The register with UNKNOWN 78 * mapping are not sent to TIS layer and handled in I2c layer. 79 * NOTE: Adding frequently used registers at the start 80 */ 81 { TPM_I2C_REG_DATA_FIFO, TPM_TIS_REG_DATA_FIFO, "FIFO", }, 82 { TPM_I2C_REG_STS, TPM_TIS_REG_STS, "STS", }, 83 { TPM_I2C_REG_DATA_CSUM_GET, TPM_I2C_REG_UNKNOWN, "CSUM_GET", }, 84 { TPM_I2C_REG_LOC_SEL, TPM_I2C_REG_UNKNOWN, "LOC_SEL", }, 85 { TPM_I2C_REG_ACCESS, TPM_TIS_REG_ACCESS, "ACCESS", }, 86 { TPM_I2C_REG_INT_ENABLE, TPM_TIS_REG_INT_ENABLE, "INTR_ENABLE",}, 87 { TPM_I2C_REG_INT_CAPABILITY, TPM_I2C_REG_UNKNOWN, "INTR_CAP", }, 88 { TPM_I2C_REG_INTF_CAPABILITY, TPM_TIS_REG_INTF_CAPABILITY, "INTF_CAP", }, 89 { TPM_I2C_REG_DID_VID, TPM_TIS_REG_DID_VID, "DID_VID", }, 90 { TPM_I2C_REG_RID, TPM_TIS_REG_RID, "RID", }, 91 { TPM_I2C_REG_I2C_DEV_ADDRESS, TPM_I2C_REG_UNKNOWN, "DEV_ADDRESS",}, 92 { TPM_I2C_REG_DATA_CSUM_ENABLE, TPM_I2C_REG_UNKNOWN, "CSUM_ENABLE",}, 93 }; 94 95 static int tpm_tis_i2c_pre_save(void *opaque) 96 { 97 TPMStateI2C *i2cst = opaque; 98 99 return tpm_tis_pre_save(&i2cst->state); 100 } 101 102 static int tpm_tis_i2c_post_load(void *opaque, int version_id) 103 { 104 TPMStateI2C *i2cst = opaque; 105 106 if (i2cst->offset >= 1) { 107 tpm_tis_i2c_to_tis_reg(i2cst, i2cst->data[0]); 108 } 109 110 return 0; 111 } 112 113 static const VMStateDescription vmstate_tpm_tis_i2c = { 114 .name = "tpm-tis-i2c", 115 .version_id = 0, 116 .pre_save = tpm_tis_i2c_pre_save, 117 .post_load = tpm_tis_i2c_post_load, 118 .fields = (VMStateField[]) { 119 VMSTATE_BUFFER(state.buffer, TPMStateI2C), 120 VMSTATE_UINT16(state.rw_offset, TPMStateI2C), 121 VMSTATE_UINT8(state.active_locty, TPMStateI2C), 122 VMSTATE_UINT8(state.aborting_locty, TPMStateI2C), 123 VMSTATE_UINT8(state.next_locty, TPMStateI2C), 124 125 VMSTATE_STRUCT_ARRAY(state.loc, TPMStateI2C, TPM_TIS_NUM_LOCALITIES, 0, 126 vmstate_locty, TPMLocality), 127 128 /* i2c specifics */ 129 VMSTATE_UINT8(offset, TPMStateI2C), 130 VMSTATE_UINT8(operation, TPMStateI2C), 131 VMSTATE_BUFFER(data, TPMStateI2C), 132 VMSTATE_UINT8(loc_sel, TPMStateI2C), 133 VMSTATE_UINT8(csum_enable, TPMStateI2C), 134 135 VMSTATE_END_OF_LIST() 136 } 137 }; 138 139 /* 140 * Set data value. The i2cst->offset is not updated as called in 141 * the read path. 142 */ 143 static void tpm_tis_i2c_set_data(TPMStateI2C *i2cst, uint32_t data) 144 { 145 i2cst->data[1] = data; 146 i2cst->data[2] = data >> 8; 147 i2cst->data[3] = data >> 16; 148 i2cst->data[4] = data >> 24; 149 } 150 /* 151 * Generate interface capability based on what is returned by TIS and what is 152 * expected by I2C. Save the capability in the data array overwriting the TIS 153 * capability. 154 */ 155 static uint32_t tpm_tis_i2c_interface_capability(TPMStateI2C *i2cst, 156 uint32_t tis_cap) 157 { 158 uint32_t i2c_cap; 159 160 /* Now generate i2c capability */ 161 i2c_cap = (TPM_I2C_CAP_INTERFACE_TYPE | 162 TPM_I2C_CAP_INTERFACE_VER | 163 TPM_I2C_CAP_TPM2_FAMILY | 164 TPM_I2C_CAP_LOCALITY_CAP | 165 TPM_I2C_CAP_BUS_SPEED | 166 TPM_I2C_CAP_DEV_ADDR_CHANGE); 167 168 /* Now check the TIS and set some capabilities */ 169 170 /* Static burst count set */ 171 if (tis_cap & TPM_TIS_CAP_BURST_COUNT_STATIC) { 172 i2c_cap |= TPM_I2C_CAP_BURST_COUNT_STATIC; 173 } 174 175 return i2c_cap; 176 } 177 178 /* Convert I2C register to TIS address and returns the name of the register */ 179 static inline void tpm_tis_i2c_to_tis_reg(TPMStateI2C *i2cst, uint8_t i2c_reg) 180 { 181 const I2CRegMap *reg_map; 182 int i; 183 184 i2cst->tis_addr = 0xffffffff; 185 186 /* Special case for the STS register. */ 187 if (i2c_reg >= TPM_I2C_REG_STS && i2c_reg <= TPM_I2C_REG_STS + 3) { 188 i2c_reg = TPM_I2C_REG_STS; 189 } 190 191 for (i = 0; i < ARRAY_SIZE(tpm_tis_reg_map); i++) { 192 reg_map = &tpm_tis_reg_map[i]; 193 if (reg_map->i2c_reg == i2c_reg) { 194 i2cst->reg_name = reg_map->reg_name; 195 i2cst->tis_addr = reg_map->tis_reg; 196 197 /* Include the locality in the address. */ 198 assert(TPM_TIS_I2C_IS_VALID_LOCTY(i2cst->loc_sel)); 199 i2cst->tis_addr += (i2cst->loc_sel << TPM_TIS_LOCALITY_SHIFT); 200 break; 201 } 202 } 203 } 204 205 /* Clear some fields from the structure. */ 206 static inline void tpm_tis_i2c_clear_data(TPMStateI2C *i2cst) 207 { 208 /* Clear operation and offset */ 209 i2cst->operation = 0; 210 i2cst->offset = 0; 211 i2cst->tis_addr = 0xffffffff; 212 i2cst->reg_name = NULL; 213 memset(i2cst->data, 0, sizeof(i2cst->data)); 214 215 return; 216 } 217 218 /* Send data to TPM */ 219 static inline void tpm_tis_i2c_tpm_send(TPMStateI2C *i2cst) 220 { 221 uint32_t data; 222 size_t offset = 0; 223 uint32_t sz = 4; 224 225 if ((i2cst->operation == OP_SEND) && (i2cst->offset > 1)) { 226 227 switch (i2cst->data[0]) { 228 case TPM_I2C_REG_DATA_CSUM_ENABLE: 229 /* 230 * Checksum is not handled by TIS code hence we will consume the 231 * register here. 232 */ 233 i2cst->csum_enable = i2cst->data[1] & TPM_DATA_CSUM_ENABLED; 234 break; 235 case TPM_I2C_REG_DATA_FIFO: 236 /* Handled in the main i2c_send function */ 237 break; 238 case TPM_I2C_REG_LOC_SEL: 239 /* 240 * This register is not handled by TIS so save the locality 241 * locally 242 */ 243 if (TPM_TIS_I2C_IS_VALID_LOCTY(i2cst->data[1])) { 244 i2cst->loc_sel = i2cst->data[1]; 245 } 246 break; 247 default: 248 /* We handle non-FIFO here */ 249 250 /* Index 0 is a register. Convert byte stream to uint32_t */ 251 data = i2cst->data[1]; 252 data |= i2cst->data[2] << 8; 253 data |= i2cst->data[3] << 16; 254 data |= i2cst->data[4] << 24; 255 256 /* Add register specific masking */ 257 switch (i2cst->data[0]) { 258 case TPM_I2C_REG_INT_ENABLE: 259 data &= TPM_I2C_INT_ENABLE_MASK; 260 break; 261 case TPM_I2C_REG_STS ... TPM_I2C_REG_STS + 3: 262 /* 263 * STS register has 4 bytes data. 264 * As per the specs following writes must be allowed. 265 * - From base address 1 to 4 bytes are allowed. 266 * - Single byte write to first or last byte must 267 * be allowed. 268 */ 269 offset = i2cst->data[0] - TPM_I2C_REG_STS; 270 if (offset > 0) { 271 sz = 1; 272 } 273 data &= (TPM_I2C_STS_WRITE_MASK >> (offset * 8)); 274 break; 275 } 276 277 tpm_tis_write_data(&i2cst->state, i2cst->tis_addr + offset, data, 278 sz); 279 break; 280 } 281 282 tpm_tis_i2c_clear_data(i2cst); 283 } 284 285 return; 286 } 287 288 /* Callback from TPM to indicate that response is copied */ 289 static void tpm_tis_i2c_request_completed(TPMIf *ti, int ret) 290 { 291 TPMStateI2C *i2cst = TPM_TIS_I2C(ti); 292 TPMState *s = &i2cst->state; 293 294 /* Inform the common code. */ 295 tpm_tis_request_completed(s, ret); 296 } 297 298 static enum TPMVersion tpm_tis_i2c_get_tpm_version(TPMIf *ti) 299 { 300 TPMStateI2C *i2cst = TPM_TIS_I2C(ti); 301 TPMState *s = &i2cst->state; 302 303 return tpm_tis_get_tpm_version(s); 304 } 305 306 static int tpm_tis_i2c_event(I2CSlave *i2c, enum i2c_event event) 307 { 308 TPMStateI2C *i2cst = TPM_TIS_I2C(i2c); 309 int ret = 0; 310 311 switch (event) { 312 case I2C_START_RECV: 313 trace_tpm_tis_i2c_event("START_RECV"); 314 break; 315 case I2C_START_SEND: 316 trace_tpm_tis_i2c_event("START_SEND"); 317 tpm_tis_i2c_clear_data(i2cst); 318 break; 319 case I2C_FINISH: 320 trace_tpm_tis_i2c_event("FINISH"); 321 if (i2cst->operation == OP_SEND) { 322 tpm_tis_i2c_tpm_send(i2cst); 323 } else { 324 tpm_tis_i2c_clear_data(i2cst); 325 } 326 break; 327 default: 328 break; 329 } 330 331 return ret; 332 } 333 334 /* 335 * If data is for FIFO then it is received from tpm_tis_common buffer 336 * otherwise it will be handled using single call to common code and 337 * cached in the local buffer. 338 */ 339 static uint8_t tpm_tis_i2c_recv(I2CSlave *i2c) 340 { 341 int ret = 0; 342 uint32_t data_read; 343 TPMStateI2C *i2cst = TPM_TIS_I2C(i2c); 344 TPMState *s = &i2cst->state; 345 uint16_t i2c_reg = i2cst->data[0]; 346 size_t offset; 347 348 if (i2cst->operation == OP_RECV) { 349 350 /* Do not cache FIFO data. */ 351 if (i2cst->data[0] == TPM_I2C_REG_DATA_FIFO) { 352 data_read = tpm_tis_read_data(s, i2cst->tis_addr, 1); 353 ret = (data_read & 0xff); 354 } else if (i2cst->offset < sizeof(i2cst->data)) { 355 ret = i2cst->data[i2cst->offset++]; 356 } 357 358 } else if ((i2cst->operation == OP_SEND) && (i2cst->offset < 2)) { 359 /* First receive call after send */ 360 361 i2cst->operation = OP_RECV; 362 363 switch (i2c_reg) { 364 case TPM_I2C_REG_LOC_SEL: 365 /* Location selection register is managed by i2c */ 366 tpm_tis_i2c_set_data(i2cst, i2cst->loc_sel); 367 break; 368 case TPM_I2C_REG_DATA_FIFO: 369 /* FIFO data is directly read from TPM TIS */ 370 data_read = tpm_tis_read_data(s, i2cst->tis_addr, 1); 371 tpm_tis_i2c_set_data(i2cst, (data_read & 0xff)); 372 break; 373 case TPM_I2C_REG_DATA_CSUM_ENABLE: 374 tpm_tis_i2c_set_data(i2cst, i2cst->csum_enable); 375 break; 376 case TPM_I2C_REG_INT_CAPABILITY: 377 /* 378 * Interrupt is not supported in the linux kernel hence we cannot 379 * test this model with interrupts. 380 */ 381 tpm_tis_i2c_set_data(i2cst, TPM_I2C_INT_ENABLE_MASK); 382 break; 383 case TPM_I2C_REG_DATA_CSUM_GET: 384 /* 385 * Checksum registers are not supported by common code hence 386 * call a common code to get the checksum. 387 */ 388 data_read = tpm_tis_get_checksum(s); 389 390 /* Save the byte stream in data field */ 391 tpm_tis_i2c_set_data(i2cst, data_read); 392 break; 393 default: 394 data_read = tpm_tis_read_data(s, i2cst->tis_addr, 4); 395 396 switch (i2c_reg) { 397 case TPM_I2C_REG_INTF_CAPABILITY: 398 /* Prepare the capabilities as per I2C interface */ 399 data_read = tpm_tis_i2c_interface_capability(i2cst, 400 data_read); 401 break; 402 case TPM_I2C_REG_STS ... TPM_I2C_REG_STS + 3: 403 offset = i2c_reg - TPM_I2C_REG_STS; 404 /* 405 * As per specs, STS bit 31:26 are reserved and must 406 * be set to 0 407 */ 408 data_read &= TPM_I2C_STS_READ_MASK; 409 /* 410 * STS register has 4 bytes data. 411 * As per the specs following reads must be allowed. 412 * - From base address 1 to 4 bytes are allowed. 413 * - Last byte must be allowed to read as a single byte 414 * - Second and third byte must be allowed to read as two 415 * two bytes. 416 */ 417 data_read >>= (offset * 8); 418 break; 419 } 420 421 /* Save byte stream in data[] */ 422 tpm_tis_i2c_set_data(i2cst, data_read); 423 break; 424 } 425 426 /* Return first byte with this call */ 427 i2cst->offset = 1; /* keep the register value intact for debug */ 428 ret = i2cst->data[i2cst->offset++]; 429 } else { 430 i2cst->operation = OP_RECV; 431 } 432 433 trace_tpm_tis_i2c_recv(ret); 434 435 return ret; 436 } 437 438 /* 439 * Send function only remembers data in the buffer and then calls 440 * TPM TIS common code during FINISH event. 441 */ 442 static int tpm_tis_i2c_send(I2CSlave *i2c, uint8_t data) 443 { 444 TPMStateI2C *i2cst = TPM_TIS_I2C(i2c); 445 446 /* Reject non-supported registers. */ 447 if (i2cst->offset == 0) { 448 /* Convert I2C register to TIS register */ 449 tpm_tis_i2c_to_tis_reg(i2cst, data); 450 if (i2cst->tis_addr == 0xffffffff) { 451 return 0xffffffff; 452 } 453 454 trace_tpm_tis_i2c_send_reg(i2cst->reg_name, data); 455 456 /* We do not support device address change */ 457 if (data == TPM_I2C_REG_I2C_DEV_ADDRESS) { 458 qemu_log_mask(LOG_UNIMP, "%s: Device address change " 459 "is not supported.\n", __func__); 460 return 0xffffffff; 461 } 462 } else { 463 trace_tpm_tis_i2c_send(data); 464 } 465 466 if (i2cst->offset < sizeof(i2cst->data)) { 467 i2cst->operation = OP_SEND; 468 469 /* 470 * In two cases, we save values in the local buffer. 471 * 1) The first value is always a register. 472 * 2) In case of non-FIFO multibyte registers, TIS expects full 473 * register value hence I2C layer cache the register value and send 474 * to TIS during FINISH event. 475 */ 476 if ((i2cst->offset == 0) || 477 (i2cst->data[0] != TPM_I2C_REG_DATA_FIFO)) { 478 i2cst->data[i2cst->offset++] = data; 479 } else { 480 /* 481 * The TIS can process FIFO data one byte at a time hence the FIFO 482 * data is sent to TIS directly. 483 */ 484 tpm_tis_write_data(&i2cst->state, i2cst->tis_addr, data, 1); 485 } 486 487 return 0; 488 } 489 490 /* Return non-zero to indicate NAK */ 491 return 1; 492 } 493 494 static Property tpm_tis_i2c_properties[] = { 495 DEFINE_PROP_TPMBE("tpmdev", TPMStateI2C, state.be_driver), 496 DEFINE_PROP_END_OF_LIST(), 497 }; 498 499 static void tpm_tis_i2c_realizefn(DeviceState *dev, Error **errp) 500 { 501 TPMStateI2C *i2cst = TPM_TIS_I2C(dev); 502 TPMState *s = &i2cst->state; 503 504 if (!tpm_find()) { 505 error_setg(errp, "at most one TPM device is permitted"); 506 return; 507 } 508 509 /* 510 * Get the backend pointer. It is not initialized propery during 511 * device_class_set_props 512 */ 513 s->be_driver = qemu_find_tpm_be("tpm0"); 514 515 if (!s->be_driver) { 516 error_setg(errp, "'tpmdev' property is required"); 517 return; 518 } 519 } 520 521 static void tpm_tis_i2c_reset(DeviceState *dev) 522 { 523 TPMStateI2C *i2cst = TPM_TIS_I2C(dev); 524 TPMState *s = &i2cst->state; 525 526 tpm_tis_i2c_clear_data(i2cst); 527 528 i2cst->csum_enable = 0; 529 i2cst->loc_sel = 0x00; 530 531 return tpm_tis_reset(s); 532 } 533 534 static void tpm_tis_i2c_class_init(ObjectClass *klass, void *data) 535 { 536 DeviceClass *dc = DEVICE_CLASS(klass); 537 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); 538 TPMIfClass *tc = TPM_IF_CLASS(klass); 539 540 dc->realize = tpm_tis_i2c_realizefn; 541 dc->reset = tpm_tis_i2c_reset; 542 dc->vmsd = &vmstate_tpm_tis_i2c; 543 device_class_set_props(dc, tpm_tis_i2c_properties); 544 set_bit(DEVICE_CATEGORY_MISC, dc->categories); 545 546 k->event = tpm_tis_i2c_event; 547 k->recv = tpm_tis_i2c_recv; 548 k->send = tpm_tis_i2c_send; 549 550 tc->model = TPM_MODEL_TPM_TIS; 551 tc->request_completed = tpm_tis_i2c_request_completed; 552 tc->get_version = tpm_tis_i2c_get_tpm_version; 553 } 554 555 static const TypeInfo tpm_tis_i2c_info = { 556 .name = TYPE_TPM_TIS_I2C, 557 .parent = TYPE_I2C_SLAVE, 558 .instance_size = sizeof(TPMStateI2C), 559 .class_init = tpm_tis_i2c_class_init, 560 .interfaces = (InterfaceInfo[]) { 561 { TYPE_TPM_IF }, 562 { } 563 } 564 }; 565 566 static void tpm_tis_i2c_register_types(void) 567 { 568 type_register_static(&tpm_tis_i2c_info); 569 } 570 571 type_init(tpm_tis_i2c_register_types) 572