2 * Copyright (C) 2004 IBM Corporation
5 * Leendert van Doorn <leendert@watson.ibm.com>
6 * Dave Safford <safford@watson.ibm.com>
7 * Reiner Sailer <sailer@watson.ibm.com>
8 * Kylene Hall <kjhall@us.ibm.com>
10 * Maintained by: <tpmdd_devel@lists.sourceforge.net>
12 * Device driver for TCG/TCPA TPM (trusted platform module).
13 * Specifications at www.trustedcomputinggroup.org
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License as
17 * published by the Free Software Foundation, version 2 of the
20 * Note, the TPM chip is not interrupt driven (only polling)
21 * and can have very long timeouts (minutes!). Hence the unusual
26 #include <linux/sched.h>
27 #include <linux/poll.h>
28 #include <linux/spinlock.h>
32 TPM_MINOR = 224, /* officially assigned */
34 TPM_NUM_DEVICES = 256,
35 TPM_NUM_MASK_ENTRIES = TPM_NUM_DEVICES / (8 * sizeof(int))
38 static LIST_HEAD(tpm_chip_list);
39 static DEFINE_SPINLOCK(driver_lock);
40 static int dev_mask[TPM_NUM_MASK_ENTRIES];
42 static void user_reader_timeout(unsigned long ptr)
44 struct tpm_chip *chip = (struct tpm_chip *) ptr;
46 schedule_work(&chip->work);
49 static void timeout_work(void *ptr)
51 struct tpm_chip *chip = ptr;
53 down(&chip->buffer_mutex);
54 atomic_set(&chip->data_pending, 0);
55 memset(chip->data_buffer, 0, TPM_BUFSIZE);
56 up(&chip->buffer_mutex);
60 * Internal kernel interface to transmit TPM commands
62 static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
69 count = be32_to_cpu(*((__be32 *) (buf + 2)));
75 "invalid count value %x %zx \n", count, bufsiz);
79 down(&chip->tpm_mutex);
81 if ((rc = chip->vendor.send(chip, (u8 *) buf, count)) < 0) {
83 "tpm_transmit: tpm_send: error %zd\n", rc);
87 stop = jiffies + 2 * 60 * HZ;
89 u8 status = chip->vendor.status(chip);
90 if ((status & chip->vendor.req_complete_mask) ==
91 chip->vendor.req_complete_val)
94 if ((status == chip->vendor.req_canceled)) {
95 dev_err(chip->dev, "Operation Canceled\n");
100 msleep(TPM_TIMEOUT); /* CHECK */
102 } while (time_before(jiffies, stop));
104 chip->vendor.cancel(chip);
105 dev_err(chip->dev, "Operation Timed out\n");
110 rc = chip->vendor.recv(chip, (u8 *) buf, bufsiz);
113 "tpm_transmit: tpm_recv: error %zd\n", rc);
115 up(&chip->tpm_mutex);
119 #define TPM_DIGEST_SIZE 20
120 #define TPM_ERROR_SIZE 10
121 #define TPM_RET_CODE_IDX 6
122 #define TPM_GET_CAP_RET_SIZE_IDX 10
123 #define TPM_GET_CAP_RET_UINT32_1_IDX 14
124 #define TPM_GET_CAP_RET_UINT32_2_IDX 18
125 #define TPM_GET_CAP_RET_UINT32_3_IDX 22
126 #define TPM_GET_CAP_RET_UINT32_4_IDX 26
128 #define TPM_CAP_IDX 13
129 #define TPM_CAP_SUBCAP_IDX 21
131 enum tpm_capabilities {
135 enum tpm_sub_capabilities {
136 TPM_CAP_PROP_PCR = 0x1,
137 TPM_CAP_PROP_MANUFACTURER = 0x3,
141 * This is a semi generic GetCapability command for use
142 * with the capability type TPM_CAP_PROP or TPM_CAP_FLAG
143 * and their associated sub_capabilities.
146 static const u8 tpm_cap[] = {
147 0, 193, /* TPM_TAG_RQU_COMMAND */
148 0, 0, 0, 22, /* length */
149 0, 0, 0, 101, /* TPM_ORD_GetCapability */
150 0, 0, 0, 0, /* TPM_CAP_<TYPE> */
151 0, 0, 0, 4, /* TPM_CAP_SUB_<TYPE> size */
152 0, 0, 1, 0 /* TPM_CAP_SUB_<TYPE> */
155 static ssize_t transmit_cmd(struct tpm_chip *chip, u8 *data, int len,
160 len = tpm_transmit(chip, data, len);
163 if (len == TPM_ERROR_SIZE) {
164 err = be32_to_cpu(*((__be32 *) (data + TPM_RET_CODE_IDX)));
165 dev_dbg(chip->dev, "A TPM error (%d) occurred %s\n", err, desc);
171 static const u8 pcrread[] = {
172 0, 193, /* TPM_TAG_RQU_COMMAND */
173 0, 0, 0, 14, /* length */
174 0, 0, 0, 21, /* TPM_ORD_PcrRead */
175 0, 0, 0, 0 /* PCR index */
178 ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
187 struct tpm_chip *chip = dev_get_drvdata(dev);
191 memcpy(data, tpm_cap, sizeof(tpm_cap));
192 data[TPM_CAP_IDX] = TPM_CAP_PROP;
193 data[TPM_CAP_SUBCAP_IDX] = TPM_CAP_PROP_PCR;
195 rc = transmit_cmd(chip, data, sizeof(data),
196 "attempting to determine the number of PCRS");
200 num_pcrs = be32_to_cpu(*((__be32 *) (data + 14)));
201 for (i = 0; i < num_pcrs; i++) {
202 memcpy(data, pcrread, sizeof(pcrread));
203 index = cpu_to_be32(i);
204 memcpy(data + 10, &index, 4);
205 rc = transmit_cmd(chip, data, sizeof(data),
206 "attempting to read a PCR");
209 str += sprintf(str, "PCR-%02d: ", i);
210 for (j = 0; j < TPM_DIGEST_SIZE; j++)
211 str += sprintf(str, "%02X ", *(data + 10 + j));
212 str += sprintf(str, "\n");
217 EXPORT_SYMBOL_GPL(tpm_show_pcrs);
219 #define READ_PUBEK_RESULT_SIZE 314
220 static const u8 readpubek[] = {
221 0, 193, /* TPM_TAG_RQU_COMMAND */
222 0, 0, 0, 30, /* length */
223 0, 0, 0, 124, /* TPM_ORD_ReadPubek */
226 ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
234 struct tpm_chip *chip = dev_get_drvdata(dev);
238 data = kzalloc(READ_PUBEK_RESULT_SIZE, GFP_KERNEL);
242 memcpy(data, readpubek, sizeof(readpubek));
244 err = transmit_cmd(chip, data, READ_PUBEK_RESULT_SIZE,
245 "attempting to read the PUBEK");
250 ignore header 10 bytes
251 algorithm 32 bits (1 == RSA )
254 parameters (RSA 12->bytes: keybit, #primes, expbit)
257 ignore checksum 20 bytes
262 "Algorithm: %02X %02X %02X %02X\nEncscheme: %02X %02X\n"
263 "Sigscheme: %02X %02X\nParameters: %02X %02X %02X %02X"
264 " %02X %02X %02X %02X %02X %02X %02X %02X\n"
265 "Modulus length: %d\nModulus: \n",
266 data[10], data[11], data[12], data[13], data[14],
267 data[15], data[16], data[17], data[22], data[23],
268 data[24], data[25], data[26], data[27], data[28],
269 data[29], data[30], data[31], data[32], data[33],
270 be32_to_cpu(*((__be32 *) (data + 34))));
272 for (i = 0; i < 256; i++) {
273 str += sprintf(str, "%02X ", data[i + 38]);
274 if ((i + 1) % 16 == 0)
275 str += sprintf(str, "\n");
282 EXPORT_SYMBOL_GPL(tpm_show_pubek);
284 #define CAP_VERSION_1_1 6
285 #define CAP_VERSION_IDX 13
286 static const u8 cap_version[] = {
287 0, 193, /* TPM_TAG_RQU_COMMAND */
288 0, 0, 0, 18, /* length */
289 0, 0, 0, 101, /* TPM_ORD_GetCapability */
294 ssize_t tpm_show_caps(struct device *dev, struct device_attribute *attr,
301 struct tpm_chip *chip = dev_get_drvdata(dev);
305 memcpy(data, tpm_cap, sizeof(tpm_cap));
306 data[TPM_CAP_IDX] = TPM_CAP_PROP;
307 data[TPM_CAP_SUBCAP_IDX] = TPM_CAP_PROP_MANUFACTURER;
309 rc = transmit_cmd(chip, data, sizeof(data),
310 "attempting to determine the manufacturer");
314 str += sprintf(str, "Manufacturer: 0x%x\n",
315 be32_to_cpu(*((__be32 *) (data + TPM_GET_CAP_RET_UINT32_1_IDX))));
317 memcpy(data, cap_version, sizeof(cap_version));
318 data[CAP_VERSION_IDX] = CAP_VERSION_1_1;
319 rc = transmit_cmd(chip, data, sizeof(data),
320 "attempting to determine the 1.1 version");
325 "TCG version: %d.%d\nFirmware version: %d.%d\n",
326 (int) data[14], (int) data[15], (int) data[16],
332 EXPORT_SYMBOL_GPL(tpm_show_caps);
334 ssize_t tpm_store_cancel(struct device *dev, struct device_attribute *attr,
335 const char *buf, size_t count)
337 struct tpm_chip *chip = dev_get_drvdata(dev);
341 chip->vendor.cancel(chip);
344 EXPORT_SYMBOL_GPL(tpm_store_cancel);
347 * Device file system interface to the TPM
349 int tpm_open(struct inode *inode, struct file *file)
351 int rc = 0, minor = iminor(inode);
352 struct tpm_chip *chip = NULL, *pos;
354 spin_lock(&driver_lock);
356 list_for_each_entry(pos, &tpm_chip_list, list) {
357 if (pos->vendor.miscdev.minor == minor) {
368 if (chip->num_opens) {
369 dev_dbg(chip->dev, "Another process owns this TPM\n");
375 get_device(chip->dev);
377 spin_unlock(&driver_lock);
379 chip->data_buffer = kmalloc(TPM_BUFSIZE * sizeof(u8), GFP_KERNEL);
380 if (chip->data_buffer == NULL) {
382 put_device(chip->dev);
386 atomic_set(&chip->data_pending, 0);
388 file->private_data = chip;
392 spin_unlock(&driver_lock);
395 EXPORT_SYMBOL_GPL(tpm_open);
397 int tpm_release(struct inode *inode, struct file *file)
399 struct tpm_chip *chip = file->private_data;
401 spin_lock(&driver_lock);
402 file->private_data = NULL;
404 del_singleshot_timer_sync(&chip->user_read_timer);
405 flush_scheduled_work();
406 atomic_set(&chip->data_pending, 0);
407 put_device(chip->dev);
408 kfree(chip->data_buffer);
409 spin_unlock(&driver_lock);
412 EXPORT_SYMBOL_GPL(tpm_release);
414 ssize_t tpm_write(struct file *file, const char __user *buf,
415 size_t size, loff_t *off)
417 struct tpm_chip *chip = file->private_data;
418 int in_size = size, out_size;
420 /* cannot perform a write until the read has cleared
421 either via tpm_read or a user_read_timer timeout */
422 while (atomic_read(&chip->data_pending) != 0)
425 down(&chip->buffer_mutex);
427 if (in_size > TPM_BUFSIZE)
428 in_size = TPM_BUFSIZE;
431 (chip->data_buffer, (void __user *) buf, in_size)) {
432 up(&chip->buffer_mutex);
436 /* atomic tpm command send and result receive */
437 out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE);
439 atomic_set(&chip->data_pending, out_size);
440 up(&chip->buffer_mutex);
442 /* Set a timeout by which the reader must come claim the result */
443 mod_timer(&chip->user_read_timer, jiffies + (60 * HZ));
447 EXPORT_SYMBOL_GPL(tpm_write);
449 ssize_t tpm_read(struct file *file, char __user *buf,
450 size_t size, loff_t *off)
452 struct tpm_chip *chip = file->private_data;
455 del_singleshot_timer_sync(&chip->user_read_timer);
456 flush_scheduled_work();
457 ret_size = atomic_read(&chip->data_pending);
458 atomic_set(&chip->data_pending, 0);
459 if (ret_size > 0) { /* relay data */
463 down(&chip->buffer_mutex);
464 if (copy_to_user(buf, chip->data_buffer, ret_size))
466 up(&chip->buffer_mutex);
471 EXPORT_SYMBOL_GPL(tpm_read);
473 void tpm_remove_hardware(struct device *dev)
475 struct tpm_chip *chip = dev_get_drvdata(dev);
478 dev_err(dev, "No device data found\n");
482 spin_lock(&driver_lock);
484 list_del(&chip->list);
486 spin_unlock(&driver_lock);
488 dev_set_drvdata(dev, NULL);
489 misc_deregister(&chip->vendor.miscdev);
490 kfree(chip->vendor.miscdev.name);
492 sysfs_remove_group(&dev->kobj, chip->vendor.attr_group);
493 tpm_bios_log_teardown(chip->bios_dir);
495 dev_mask[chip->dev_num / TPM_NUM_MASK_ENTRIES] &=
496 ~(1 << (chip->dev_num % TPM_NUM_MASK_ENTRIES));
502 EXPORT_SYMBOL_GPL(tpm_remove_hardware);
504 static u8 savestate[] = {
505 0, 193, /* TPM_TAG_RQU_COMMAND */
506 0, 0, 0, 10, /* blob length (in bytes) */
507 0, 0, 0, 152 /* TPM_ORD_SaveState */
511 * We are about to suspend. Save the TPM state
512 * so that it can be restored.
514 int tpm_pm_suspend(struct device *dev, pm_message_t pm_state)
516 struct tpm_chip *chip = dev_get_drvdata(dev);
520 tpm_transmit(chip, savestate, sizeof(savestate));
523 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
526 * Resume from a power safe. The BIOS already restored
529 int tpm_pm_resume(struct device *dev)
531 struct tpm_chip *chip = dev_get_drvdata(dev);
538 EXPORT_SYMBOL_GPL(tpm_pm_resume);
541 * Called from tpm_<specific>.c probe function only for devices
542 * the driver has determined it should claim. Prior to calling
543 * this function the specific probe function has called pci_enable_device
544 * upon errant exit from this function specific probe function should call
547 struct tpm_chip *tpm_register_hardware(struct device *dev, const struct tpm_vendor_specific
550 #define DEVNAME_SIZE 7
553 struct tpm_chip *chip;
556 /* Driver specific per-device data */
557 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
561 init_MUTEX(&chip->buffer_mutex);
562 init_MUTEX(&chip->tpm_mutex);
563 INIT_LIST_HEAD(&chip->list);
565 INIT_WORK(&chip->work, timeout_work, chip);
567 init_timer(&chip->user_read_timer);
568 chip->user_read_timer.function = user_reader_timeout;
569 chip->user_read_timer.data = (unsigned long) chip;
571 memcpy(&chip->vendor, entry, sizeof(struct tpm_vendor_specific));
575 for (i = 0; i < TPM_NUM_MASK_ENTRIES; i++)
576 for (j = 0; j < 8 * sizeof(int); j++)
577 if ((dev_mask[i] & (1 << j)) == 0) {
579 i * TPM_NUM_MASK_ENTRIES + j;
580 dev_mask[i] |= 1 << j;
581 goto dev_num_search_complete;
584 dev_num_search_complete:
585 if (chip->dev_num < 0) {
586 dev_err(dev, "No available tpm device numbers\n");
589 } else if (chip->dev_num == 0)
590 chip->vendor.miscdev.minor = TPM_MINOR;
592 chip->vendor.miscdev.minor = MISC_DYNAMIC_MINOR;
594 devname = kmalloc(DEVNAME_SIZE, GFP_KERNEL);
595 scnprintf(devname, DEVNAME_SIZE, "%s%d", "tpm", chip->dev_num);
596 chip->vendor.miscdev.name = devname;
598 chip->vendor.miscdev.dev = dev;
599 chip->dev = get_device(dev);
601 if (misc_register(&chip->vendor.miscdev)) {
603 "unable to misc_register %s, minor %d\n",
604 chip->vendor.miscdev.name,
605 chip->vendor.miscdev.minor);
608 dev_mask[i] &= !(1 << j);
612 spin_lock(&driver_lock);
614 dev_set_drvdata(dev, chip);
616 list_add(&chip->list, &tpm_chip_list);
618 spin_unlock(&driver_lock);
620 sysfs_create_group(&dev->kobj, chip->vendor.attr_group);
622 chip->bios_dir = tpm_bios_log_setup(devname);
626 EXPORT_SYMBOL_GPL(tpm_register_hardware);
628 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
629 MODULE_DESCRIPTION("TPM Driver");
630 MODULE_VERSION("2.0");
631 MODULE_LICENSE("GPL");