1 /* 2 * Copyright (C) 2012 IBM Corporation 3 * 4 * Author: Ashley Lai <ashleydlai@gmail.com> 5 * 6 * Maintained by: <tpmdd-devel@lists.sourceforge.net> 7 * 8 * Device driver for TCG/TCPA TPM (trusted platform module). 9 * Specifications at www.trustedcomputinggroup.org 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License as 13 * published by the Free Software Foundation, version 2 of the 14 * License. 15 * 16 */ 17 18 #include <linux/dma-mapping.h> 19 #include <linux/dmapool.h> 20 #include <linux/slab.h> 21 #include <asm/vio.h> 22 #include <asm/irq.h> 23 #include <linux/types.h> 24 #include <linux/list.h> 25 #include <linux/spinlock.h> 26 #include <linux/interrupt.h> 27 #include <linux/wait.h> 28 #include <asm/prom.h> 29 30 #include "tpm.h" 31 #include "tpm_ibmvtpm.h" 32 33 static const char tpm_ibmvtpm_driver_name[] = "tpm_ibmvtpm"; 34 35 static struct vio_device_id tpm_ibmvtpm_device_table[] = { 36 { "IBM,vtpm", "IBM,vtpm"}, 37 { "", "" } 38 }; 39 MODULE_DEVICE_TABLE(vio, tpm_ibmvtpm_device_table); 40 41 /** 42 * ibmvtpm_send_crq - Send a CRQ request 43 * @vdev: vio device struct 44 * @w1: first word 45 * @w2: second word 46 * 47 * Return value: 48 * 0 -Sucess 49 * Non-zero - Failure 50 */ 51 static int ibmvtpm_send_crq(struct vio_dev *vdev, u64 w1, u64 w2) 52 { 53 return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, w1, w2); 54 } 55 56 /** 57 * ibmvtpm_get_data - Retrieve ibm vtpm data 58 * @dev: device struct 59 * 60 * Return value: 61 * vtpm device struct 62 */ 63 static struct ibmvtpm_dev *ibmvtpm_get_data(const struct device *dev) 64 { 65 struct tpm_chip *chip = dev_get_drvdata(dev); 66 if (chip) 67 return (struct ibmvtpm_dev *)TPM_VPRIV(chip); 68 return NULL; 69 } 70 71 /** 72 * tpm_ibmvtpm_recv - Receive data after send 73 * @chip: tpm chip struct 74 * @buf: buffer to read 75 * count: size of buffer 76 * 77 * Return value: 78 * Number of bytes read 79 */ 80 static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count) 81 { 82 struct ibmvtpm_dev *ibmvtpm; 83 u16 len; 84 int sig; 85 86 ibmvtpm = (struct ibmvtpm_dev *)TPM_VPRIV(chip); 87 88 if (!ibmvtpm->rtce_buf) { 89 dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n"); 90 return 0; 91 } 92 93 sig = wait_event_interruptible(ibmvtpm->wq, ibmvtpm->res_len != 0); 94 if (sig) 95 return -EINTR; 96 97 len = ibmvtpm->res_len; 98 99 if (count < len) { 100 dev_err(ibmvtpm->dev, 101 "Invalid size in recv: count=%zd, crq_size=%d\n", 102 count, len); 103 return -EIO; 104 } 105 106 spin_lock(&ibmvtpm->rtce_lock); 107 memcpy((void *)buf, (void *)ibmvtpm->rtce_buf, len); 108 memset(ibmvtpm->rtce_buf, 0, len); 109 ibmvtpm->res_len = 0; 110 spin_unlock(&ibmvtpm->rtce_lock); 111 return len; 112 } 113 114 /** 115 * tpm_ibmvtpm_send - Send tpm request 116 * @chip: tpm chip struct 117 * @buf: buffer contains data to send 118 * count: size of buffer 119 * 120 * Return value: 121 * Number of bytes sent 122 */ 123 static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count) 124 { 125 struct ibmvtpm_dev *ibmvtpm; 126 struct ibmvtpm_crq crq; 127 u64 *word = (u64 *) &crq; 128 int rc; 129 130 ibmvtpm = (struct ibmvtpm_dev *)TPM_VPRIV(chip); 131 132 if (!ibmvtpm->rtce_buf) { 133 dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n"); 134 return 0; 135 } 136 137 if (count > ibmvtpm->rtce_size) { 138 dev_err(ibmvtpm->dev, 139 "Invalid size in send: count=%zd, rtce_size=%d\n", 140 count, ibmvtpm->rtce_size); 141 return -EIO; 142 } 143 144 spin_lock(&ibmvtpm->rtce_lock); 145 memcpy((void *)ibmvtpm->rtce_buf, (void *)buf, count); 146 crq.valid = (u8)IBMVTPM_VALID_CMD; 147 crq.msg = (u8)VTPM_TPM_COMMAND; 148 crq.len = (u16)count; 149 crq.data = ibmvtpm->rtce_dma_handle; 150 151 rc = ibmvtpm_send_crq(ibmvtpm->vdev, word[0], word[1]); 152 if (rc != H_SUCCESS) { 153 dev_err(ibmvtpm->dev, "tpm_ibmvtpm_send failed rc=%d\n", rc); 154 rc = 0; 155 } else 156 rc = count; 157 158 spin_unlock(&ibmvtpm->rtce_lock); 159 return rc; 160 } 161 162 static void tpm_ibmvtpm_cancel(struct tpm_chip *chip) 163 { 164 return; 165 } 166 167 static u8 tpm_ibmvtpm_status(struct tpm_chip *chip) 168 { 169 return 0; 170 } 171 172 /** 173 * ibmvtpm_crq_get_rtce_size - Send a CRQ request to get rtce size 174 * @ibmvtpm: vtpm device struct 175 * 176 * Return value: 177 * 0 - Success 178 * Non-zero - Failure 179 */ 180 static int ibmvtpm_crq_get_rtce_size(struct ibmvtpm_dev *ibmvtpm) 181 { 182 struct ibmvtpm_crq crq; 183 u64 *buf = (u64 *) &crq; 184 int rc; 185 186 crq.valid = (u8)IBMVTPM_VALID_CMD; 187 crq.msg = (u8)VTPM_GET_RTCE_BUFFER_SIZE; 188 189 rc = ibmvtpm_send_crq(ibmvtpm->vdev, buf[0], buf[1]); 190 if (rc != H_SUCCESS) 191 dev_err(ibmvtpm->dev, 192 "ibmvtpm_crq_get_rtce_size failed rc=%d\n", rc); 193 194 return rc; 195 } 196 197 /** 198 * ibmvtpm_crq_get_version - Send a CRQ request to get vtpm version 199 * - Note that this is vtpm version and not tpm version 200 * @ibmvtpm: vtpm device struct 201 * 202 * Return value: 203 * 0 - Success 204 * Non-zero - Failure 205 */ 206 static int ibmvtpm_crq_get_version(struct ibmvtpm_dev *ibmvtpm) 207 { 208 struct ibmvtpm_crq crq; 209 u64 *buf = (u64 *) &crq; 210 int rc; 211 212 crq.valid = (u8)IBMVTPM_VALID_CMD; 213 crq.msg = (u8)VTPM_GET_VERSION; 214 215 rc = ibmvtpm_send_crq(ibmvtpm->vdev, buf[0], buf[1]); 216 if (rc != H_SUCCESS) 217 dev_err(ibmvtpm->dev, 218 "ibmvtpm_crq_get_version failed rc=%d\n", rc); 219 220 return rc; 221 } 222 223 /** 224 * ibmvtpm_crq_send_init_complete - Send a CRQ initialize complete message 225 * @ibmvtpm: vtpm device struct 226 * 227 * Return value: 228 * 0 - Success 229 * Non-zero - Failure 230 */ 231 static int ibmvtpm_crq_send_init_complete(struct ibmvtpm_dev *ibmvtpm) 232 { 233 int rc; 234 235 rc = ibmvtpm_send_crq(ibmvtpm->vdev, INIT_CRQ_COMP_CMD, 0); 236 if (rc != H_SUCCESS) 237 dev_err(ibmvtpm->dev, 238 "ibmvtpm_crq_send_init_complete failed rc=%d\n", rc); 239 240 return rc; 241 } 242 243 /** 244 * ibmvtpm_crq_send_init - Send a CRQ initialize message 245 * @ibmvtpm: vtpm device struct 246 * 247 * Return value: 248 * 0 - Success 249 * Non-zero - Failure 250 */ 251 static int ibmvtpm_crq_send_init(struct ibmvtpm_dev *ibmvtpm) 252 { 253 int rc; 254 255 rc = ibmvtpm_send_crq(ibmvtpm->vdev, INIT_CRQ_CMD, 0); 256 if (rc != H_SUCCESS) 257 dev_err(ibmvtpm->dev, 258 "ibmvtpm_crq_send_init failed rc=%d\n", rc); 259 260 return rc; 261 } 262 263 /** 264 * tpm_ibmvtpm_remove - ibm vtpm remove entry point 265 * @vdev: vio device struct 266 * 267 * Return value: 268 * 0 269 */ 270 static int tpm_ibmvtpm_remove(struct vio_dev *vdev) 271 { 272 struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(&vdev->dev); 273 struct tpm_chip *chip = dev_get_drvdata(ibmvtpm->dev); 274 int rc = 0; 275 276 tpm_chip_unregister(chip); 277 278 free_irq(vdev->irq, ibmvtpm); 279 280 do { 281 if (rc) 282 msleep(100); 283 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address); 284 } while (rc == H_BUSY || H_IS_LONG_BUSY(rc)); 285 286 dma_unmap_single(ibmvtpm->dev, ibmvtpm->crq_dma_handle, 287 CRQ_RES_BUF_SIZE, DMA_BIDIRECTIONAL); 288 free_page((unsigned long)ibmvtpm->crq_queue.crq_addr); 289 290 if (ibmvtpm->rtce_buf) { 291 dma_unmap_single(ibmvtpm->dev, ibmvtpm->rtce_dma_handle, 292 ibmvtpm->rtce_size, DMA_BIDIRECTIONAL); 293 kfree(ibmvtpm->rtce_buf); 294 } 295 296 kfree(ibmvtpm); 297 298 return 0; 299 } 300 301 /** 302 * tpm_ibmvtpm_get_desired_dma - Get DMA size needed by this driver 303 * @vdev: vio device struct 304 * 305 * Return value: 306 * Number of bytes the driver needs to DMA map 307 */ 308 static unsigned long tpm_ibmvtpm_get_desired_dma(struct vio_dev *vdev) 309 { 310 struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(&vdev->dev); 311 312 /* ibmvtpm initializes at probe time, so the data we are 313 * asking for may not be set yet. Estimate that 4K required 314 * for TCE-mapped buffer in addition to CRQ. 315 */ 316 if (!ibmvtpm) 317 return CRQ_RES_BUF_SIZE + PAGE_SIZE; 318 319 return CRQ_RES_BUF_SIZE + ibmvtpm->rtce_size; 320 } 321 322 /** 323 * tpm_ibmvtpm_suspend - Suspend 324 * @dev: device struct 325 * 326 * Return value: 327 * 0 328 */ 329 static int tpm_ibmvtpm_suspend(struct device *dev) 330 { 331 struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(dev); 332 struct ibmvtpm_crq crq; 333 u64 *buf = (u64 *) &crq; 334 int rc = 0; 335 336 crq.valid = (u8)IBMVTPM_VALID_CMD; 337 crq.msg = (u8)VTPM_PREPARE_TO_SUSPEND; 338 339 rc = ibmvtpm_send_crq(ibmvtpm->vdev, buf[0], buf[1]); 340 if (rc != H_SUCCESS) 341 dev_err(ibmvtpm->dev, 342 "tpm_ibmvtpm_suspend failed rc=%d\n", rc); 343 344 return rc; 345 } 346 347 /** 348 * ibmvtpm_reset_crq - Reset CRQ 349 * @ibmvtpm: ibm vtpm struct 350 * 351 * Return value: 352 * 0 - Success 353 * Non-zero - Failure 354 */ 355 static int ibmvtpm_reset_crq(struct ibmvtpm_dev *ibmvtpm) 356 { 357 int rc = 0; 358 359 do { 360 if (rc) 361 msleep(100); 362 rc = plpar_hcall_norets(H_FREE_CRQ, 363 ibmvtpm->vdev->unit_address); 364 } while (rc == H_BUSY || H_IS_LONG_BUSY(rc)); 365 366 memset(ibmvtpm->crq_queue.crq_addr, 0, CRQ_RES_BUF_SIZE); 367 ibmvtpm->crq_queue.index = 0; 368 369 return plpar_hcall_norets(H_REG_CRQ, ibmvtpm->vdev->unit_address, 370 ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE); 371 } 372 373 /** 374 * tpm_ibmvtpm_resume - Resume from suspend 375 * @dev: device struct 376 * 377 * Return value: 378 * 0 379 */ 380 static int tpm_ibmvtpm_resume(struct device *dev) 381 { 382 struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(dev); 383 int rc = 0; 384 385 do { 386 if (rc) 387 msleep(100); 388 rc = plpar_hcall_norets(H_ENABLE_CRQ, 389 ibmvtpm->vdev->unit_address); 390 } while (rc == H_IN_PROGRESS || rc == H_BUSY || H_IS_LONG_BUSY(rc)); 391 392 if (rc) { 393 dev_err(dev, "Error enabling ibmvtpm rc=%d\n", rc); 394 return rc; 395 } 396 397 rc = vio_enable_interrupts(ibmvtpm->vdev); 398 if (rc) { 399 dev_err(dev, "Error vio_enable_interrupts rc=%d\n", rc); 400 return rc; 401 } 402 403 rc = ibmvtpm_crq_send_init(ibmvtpm); 404 if (rc) 405 dev_err(dev, "Error send_init rc=%d\n", rc); 406 407 return rc; 408 } 409 410 static bool tpm_ibmvtpm_req_canceled(struct tpm_chip *chip, u8 status) 411 { 412 return (status == 0); 413 } 414 415 static const struct tpm_class_ops tpm_ibmvtpm = { 416 .recv = tpm_ibmvtpm_recv, 417 .send = tpm_ibmvtpm_send, 418 .cancel = tpm_ibmvtpm_cancel, 419 .status = tpm_ibmvtpm_status, 420 .req_complete_mask = 0, 421 .req_complete_val = 0, 422 .req_canceled = tpm_ibmvtpm_req_canceled, 423 }; 424 425 static const struct dev_pm_ops tpm_ibmvtpm_pm_ops = { 426 .suspend = tpm_ibmvtpm_suspend, 427 .resume = tpm_ibmvtpm_resume, 428 }; 429 430 /** 431 * ibmvtpm_crq_get_next - Get next responded crq 432 * @ibmvtpm vtpm device struct 433 * 434 * Return value: 435 * vtpm crq pointer 436 */ 437 static struct ibmvtpm_crq *ibmvtpm_crq_get_next(struct ibmvtpm_dev *ibmvtpm) 438 { 439 struct ibmvtpm_crq_queue *crq_q = &ibmvtpm->crq_queue; 440 struct ibmvtpm_crq *crq = &crq_q->crq_addr[crq_q->index]; 441 442 if (crq->valid & VTPM_MSG_RES) { 443 if (++crq_q->index == crq_q->num_entry) 444 crq_q->index = 0; 445 smp_rmb(); 446 } else 447 crq = NULL; 448 return crq; 449 } 450 451 /** 452 * ibmvtpm_crq_process - Process responded crq 453 * @crq crq to be processed 454 * @ibmvtpm vtpm device struct 455 * 456 * Return value: 457 * Nothing 458 */ 459 static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq, 460 struct ibmvtpm_dev *ibmvtpm) 461 { 462 int rc = 0; 463 464 switch (crq->valid) { 465 case VALID_INIT_CRQ: 466 switch (crq->msg) { 467 case INIT_CRQ_RES: 468 dev_info(ibmvtpm->dev, "CRQ initialized\n"); 469 rc = ibmvtpm_crq_send_init_complete(ibmvtpm); 470 if (rc) 471 dev_err(ibmvtpm->dev, "Unable to send CRQ init complete rc=%d\n", rc); 472 return; 473 case INIT_CRQ_COMP_RES: 474 dev_info(ibmvtpm->dev, 475 "CRQ initialization completed\n"); 476 return; 477 default: 478 dev_err(ibmvtpm->dev, "Unknown crq message type: %d\n", crq->msg); 479 return; 480 } 481 case IBMVTPM_VALID_CMD: 482 switch (crq->msg) { 483 case VTPM_GET_RTCE_BUFFER_SIZE_RES: 484 if (crq->len <= 0) { 485 dev_err(ibmvtpm->dev, "Invalid rtce size\n"); 486 return; 487 } 488 ibmvtpm->rtce_size = crq->len; 489 ibmvtpm->rtce_buf = kmalloc(ibmvtpm->rtce_size, 490 GFP_KERNEL); 491 if (!ibmvtpm->rtce_buf) { 492 dev_err(ibmvtpm->dev, "Failed to allocate memory for rtce buffer\n"); 493 return; 494 } 495 496 ibmvtpm->rtce_dma_handle = dma_map_single(ibmvtpm->dev, 497 ibmvtpm->rtce_buf, ibmvtpm->rtce_size, 498 DMA_BIDIRECTIONAL); 499 500 if (dma_mapping_error(ibmvtpm->dev, 501 ibmvtpm->rtce_dma_handle)) { 502 kfree(ibmvtpm->rtce_buf); 503 ibmvtpm->rtce_buf = NULL; 504 dev_err(ibmvtpm->dev, "Failed to dma map rtce buffer\n"); 505 } 506 507 return; 508 case VTPM_GET_VERSION_RES: 509 ibmvtpm->vtpm_version = crq->data; 510 return; 511 case VTPM_TPM_COMMAND_RES: 512 /* len of the data in rtce buffer */ 513 ibmvtpm->res_len = crq->len; 514 wake_up_interruptible(&ibmvtpm->wq); 515 return; 516 default: 517 return; 518 } 519 } 520 return; 521 } 522 523 /** 524 * ibmvtpm_interrupt - Interrupt handler 525 * @irq: irq number to handle 526 * @vtpm_instance: vtpm that received interrupt 527 * 528 * Returns: 529 * IRQ_HANDLED 530 **/ 531 static irqreturn_t ibmvtpm_interrupt(int irq, void *vtpm_instance) 532 { 533 struct ibmvtpm_dev *ibmvtpm = (struct ibmvtpm_dev *) vtpm_instance; 534 struct ibmvtpm_crq *crq; 535 536 /* while loop is needed for initial setup (get version and 537 * get rtce_size). There should be only one tpm request at any 538 * given time. 539 */ 540 while ((crq = ibmvtpm_crq_get_next(ibmvtpm)) != NULL) { 541 ibmvtpm_crq_process(crq, ibmvtpm); 542 crq->valid = 0; 543 smp_wmb(); 544 } 545 546 return IRQ_HANDLED; 547 } 548 549 /** 550 * tpm_ibmvtpm_probe - ibm vtpm initialize entry point 551 * @vio_dev: vio device struct 552 * @id: vio device id struct 553 * 554 * Return value: 555 * 0 - Success 556 * Non-zero - Failure 557 */ 558 static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, 559 const struct vio_device_id *id) 560 { 561 struct ibmvtpm_dev *ibmvtpm; 562 struct device *dev = &vio_dev->dev; 563 struct ibmvtpm_crq_queue *crq_q; 564 struct tpm_chip *chip; 565 int rc = -ENOMEM, rc1; 566 567 chip = tpmm_chip_alloc(dev, &tpm_ibmvtpm); 568 if (IS_ERR(chip)) 569 return PTR_ERR(chip); 570 571 ibmvtpm = kzalloc(sizeof(struct ibmvtpm_dev), GFP_KERNEL); 572 if (!ibmvtpm) { 573 dev_err(dev, "kzalloc for ibmvtpm failed\n"); 574 goto cleanup; 575 } 576 577 crq_q = &ibmvtpm->crq_queue; 578 crq_q->crq_addr = (struct ibmvtpm_crq *)get_zeroed_page(GFP_KERNEL); 579 if (!crq_q->crq_addr) { 580 dev_err(dev, "Unable to allocate memory for crq_addr\n"); 581 goto cleanup; 582 } 583 584 crq_q->num_entry = CRQ_RES_BUF_SIZE / sizeof(*crq_q->crq_addr); 585 ibmvtpm->crq_dma_handle = dma_map_single(dev, crq_q->crq_addr, 586 CRQ_RES_BUF_SIZE, 587 DMA_BIDIRECTIONAL); 588 589 if (dma_mapping_error(dev, ibmvtpm->crq_dma_handle)) { 590 dev_err(dev, "dma mapping failed\n"); 591 goto cleanup; 592 } 593 594 rc = plpar_hcall_norets(H_REG_CRQ, vio_dev->unit_address, 595 ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE); 596 if (rc == H_RESOURCE) 597 rc = ibmvtpm_reset_crq(ibmvtpm); 598 599 if (rc) { 600 dev_err(dev, "Unable to register CRQ rc=%d\n", rc); 601 goto reg_crq_cleanup; 602 } 603 604 rc = request_irq(vio_dev->irq, ibmvtpm_interrupt, 0, 605 tpm_ibmvtpm_driver_name, ibmvtpm); 606 if (rc) { 607 dev_err(dev, "Error %d register irq 0x%x\n", rc, vio_dev->irq); 608 goto init_irq_cleanup; 609 } 610 611 rc = vio_enable_interrupts(vio_dev); 612 if (rc) { 613 dev_err(dev, "Error %d enabling interrupts\n", rc); 614 goto init_irq_cleanup; 615 } 616 617 init_waitqueue_head(&ibmvtpm->wq); 618 619 crq_q->index = 0; 620 621 ibmvtpm->dev = dev; 622 ibmvtpm->vdev = vio_dev; 623 TPM_VPRIV(chip) = (void *)ibmvtpm; 624 625 spin_lock_init(&ibmvtpm->rtce_lock); 626 627 rc = ibmvtpm_crq_send_init(ibmvtpm); 628 if (rc) 629 goto init_irq_cleanup; 630 631 rc = ibmvtpm_crq_get_version(ibmvtpm); 632 if (rc) 633 goto init_irq_cleanup; 634 635 rc = ibmvtpm_crq_get_rtce_size(ibmvtpm); 636 if (rc) 637 goto init_irq_cleanup; 638 639 return tpm_chip_register(chip); 640 init_irq_cleanup: 641 do { 642 rc1 = plpar_hcall_norets(H_FREE_CRQ, vio_dev->unit_address); 643 } while (rc1 == H_BUSY || H_IS_LONG_BUSY(rc1)); 644 reg_crq_cleanup: 645 dma_unmap_single(dev, ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE, 646 DMA_BIDIRECTIONAL); 647 cleanup: 648 if (ibmvtpm) { 649 if (crq_q->crq_addr) 650 free_page((unsigned long)crq_q->crq_addr); 651 kfree(ibmvtpm); 652 } 653 654 return rc; 655 } 656 657 static struct vio_driver ibmvtpm_driver = { 658 .id_table = tpm_ibmvtpm_device_table, 659 .probe = tpm_ibmvtpm_probe, 660 .remove = tpm_ibmvtpm_remove, 661 .get_desired_dma = tpm_ibmvtpm_get_desired_dma, 662 .name = tpm_ibmvtpm_driver_name, 663 .pm = &tpm_ibmvtpm_pm_ops, 664 }; 665 666 /** 667 * ibmvtpm_module_init - Initialize ibm vtpm module 668 * 669 * Return value: 670 * 0 -Success 671 * Non-zero - Failure 672 */ 673 static int __init ibmvtpm_module_init(void) 674 { 675 return vio_register_driver(&ibmvtpm_driver); 676 } 677 678 /** 679 * ibmvtpm_module_exit - Teardown ibm vtpm module 680 * 681 * Return value: 682 * Nothing 683 */ 684 static void __exit ibmvtpm_module_exit(void) 685 { 686 vio_unregister_driver(&ibmvtpm_driver); 687 } 688 689 module_init(ibmvtpm_module_init); 690 module_exit(ibmvtpm_module_exit); 691 692 MODULE_AUTHOR("adlai@us.ibm.com"); 693 MODULE_DESCRIPTION("IBM vTPM Driver"); 694 MODULE_VERSION("1.0"); 695 MODULE_LICENSE("GPL"); 696