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 down(&chip->buffer_mutex);
47 atomic_set(&chip->data_pending, 0);
48 memset(chip->data_buffer, 0, TPM_BUFSIZE);
49 up(&chip->buffer_mutex);
53 * Internal kernel interface to transmit TPM commands
55 static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
62 count = be32_to_cpu(*((__be32 *) (buf + 2)));
68 "invalid count value %x %zx \n", count, bufsiz);
72 down(&chip->tpm_mutex);
74 if ((rc = chip->vendor->send(chip, (u8 *) buf, count)) < 0) {
76 "tpm_transmit: tpm_send: error %zd\n", rc);
80 stop = jiffies + 2 * 60 * HZ;
82 u8 status = chip->vendor->status(chip);
83 if ((status & chip->vendor->req_complete_mask) ==
84 chip->vendor->req_complete_val) {
88 if ((status == chip->vendor->req_canceled)) {
89 dev_err(chip->dev, "Operation Canceled\n");
94 msleep(TPM_TIMEOUT); /* CHECK */
96 } while (time_before(jiffies, stop));
99 chip->vendor->cancel(chip);
100 dev_err(chip->dev, "Operation Timed out\n");
105 rc = chip->vendor->recv(chip, (u8 *) buf, bufsiz);
108 "tpm_transmit: tpm_recv: error %zd\n", rc);
110 up(&chip->tpm_mutex);
114 #define TPM_DIGEST_SIZE 20
115 #define CAP_PCR_RESULT_SIZE 18
116 static const u8 cap_pcr[] = {
117 0, 193, /* TPM_TAG_RQU_COMMAND */
118 0, 0, 0, 22, /* length */
119 0, 0, 0, 101, /* TPM_ORD_GetCapability */
125 #define READ_PCR_RESULT_SIZE 30
126 static const u8 pcrread[] = {
127 0, 193, /* TPM_TAG_RQU_COMMAND */
128 0, 0, 0, 14, /* length */
129 0, 0, 0, 21, /* TPM_ORD_PcrRead */
130 0, 0, 0, 0 /* PCR index */
133 ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
136 u8 data[READ_PCR_RESULT_SIZE];
142 struct tpm_chip *chip = dev_get_drvdata(dev);
146 memcpy(data, cap_pcr, sizeof(cap_pcr));
147 if ((len = tpm_transmit(chip, data, sizeof(data)))
148 < CAP_PCR_RESULT_SIZE) {
149 dev_dbg(chip->dev, "A TPM error (%d) occurred "
150 "attempting to determine the number of PCRS\n",
151 be32_to_cpu(*((__be32 *) (data + 6))));
155 num_pcrs = be32_to_cpu(*((__be32 *) (data + 14)));
157 for (i = 0; i < num_pcrs; i++) {
158 memcpy(data, pcrread, sizeof(pcrread));
159 index = cpu_to_be32(i);
160 memcpy(data + 10, &index, 4);
161 if ((len = tpm_transmit(chip, data, sizeof(data)))
162 < READ_PCR_RESULT_SIZE){
163 dev_dbg(chip->dev, "A TPM error (%d) occurred"
164 " attempting to read PCR %d of %d\n",
165 be32_to_cpu(*((__be32 *) (data + 6))), i, num_pcrs);
168 str += sprintf(str, "PCR-%02d: ", i);
169 for (j = 0; j < TPM_DIGEST_SIZE; j++)
170 str += sprintf(str, "%02X ", *(data + 10 + j));
171 str += sprintf(str, "\n");
176 EXPORT_SYMBOL_GPL(tpm_show_pcrs);
178 #define READ_PUBEK_RESULT_SIZE 314
179 static const u8 readpubek[] = {
180 0, 193, /* TPM_TAG_RQU_COMMAND */
181 0, 0, 0, 30, /* length */
182 0, 0, 0, 124, /* TPM_ORD_ReadPubek */
185 ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
193 struct tpm_chip *chip = dev_get_drvdata(dev);
197 data = kmalloc(READ_PUBEK_RESULT_SIZE, GFP_KERNEL);
201 memcpy(data, readpubek, sizeof(readpubek));
202 memset(data + sizeof(readpubek), 0, 20); /* zero nonce */
204 if ((len = tpm_transmit(chip, data, READ_PUBEK_RESULT_SIZE)) <
205 READ_PUBEK_RESULT_SIZE) {
206 dev_dbg(chip->dev, "A TPM error (%d) occurred "
207 "attempting to read the PUBEK\n",
208 be32_to_cpu(*((__be32 *) (data + 6))));
214 ignore header 10 bytes
215 algorithm 32 bits (1 == RSA )
218 parameters (RSA 12->bytes: keybit, #primes, expbit)
221 ignore checksum 20 bytes
226 "Algorithm: %02X %02X %02X %02X\nEncscheme: %02X %02X\n"
227 "Sigscheme: %02X %02X\nParameters: %02X %02X %02X %02X"
228 " %02X %02X %02X %02X %02X %02X %02X %02X\n"
229 "Modulus length: %d\nModulus: \n",
230 data[10], data[11], data[12], data[13], data[14],
231 data[15], data[16], data[17], data[22], data[23],
232 data[24], data[25], data[26], data[27], data[28],
233 data[29], data[30], data[31], data[32], data[33],
234 be32_to_cpu(*((__be32 *) (data + 34))));
236 for (i = 0; i < 256; i++) {
237 str += sprintf(str, "%02X ", data[i + 38]);
238 if ((i + 1) % 16 == 0)
239 str += sprintf(str, "\n");
247 EXPORT_SYMBOL_GPL(tpm_show_pubek);
249 #define CAP_VER_RESULT_SIZE 18
250 static const u8 cap_version[] = {
251 0, 193, /* TPM_TAG_RQU_COMMAND */
252 0, 0, 0, 18, /* length */
253 0, 0, 0, 101, /* TPM_ORD_GetCapability */
258 #define CAP_MANUFACTURER_RESULT_SIZE 18
259 static const u8 cap_manufacturer[] = {
260 0, 193, /* TPM_TAG_RQU_COMMAND */
261 0, 0, 0, 22, /* length */
262 0, 0, 0, 101, /* TPM_ORD_GetCapability */
268 ssize_t tpm_show_caps(struct device *dev, struct device_attribute *attr,
271 u8 data[sizeof(cap_manufacturer)];
275 struct tpm_chip *chip = dev_get_drvdata(dev);
279 memcpy(data, cap_manufacturer, sizeof(cap_manufacturer));
281 if ((len = tpm_transmit(chip, data, sizeof(data))) <
282 CAP_MANUFACTURER_RESULT_SIZE)
285 str += sprintf(str, "Manufacturer: 0x%x\n",
286 be32_to_cpu(*((__be32 *) (data + 14))));
288 memcpy(data, cap_version, sizeof(cap_version));
290 if ((len = tpm_transmit(chip, data, sizeof(data))) <
295 sprintf(str, "TCG version: %d.%d\nFirmware version: %d.%d\n",
296 (int) data[14], (int) data[15], (int) data[16],
301 EXPORT_SYMBOL_GPL(tpm_show_caps);
303 ssize_t tpm_store_cancel(struct device *dev, struct device_attribute *attr,
304 const char *buf, size_t count)
306 struct tpm_chip *chip = dev_get_drvdata(dev);
310 chip->vendor->cancel(chip);
313 EXPORT_SYMBOL_GPL(tpm_store_cancel);
317 * Device file system interface to the TPM
319 int tpm_open(struct inode *inode, struct file *file)
321 int rc = 0, minor = iminor(inode);
322 struct tpm_chip *chip = NULL, *pos;
324 spin_lock(&driver_lock);
326 list_for_each_entry(pos, &tpm_chip_list, list) {
327 if (pos->vendor->miscdev.minor == minor) {
338 if (chip->num_opens) {
340 "Another process owns this TPM\n");
346 get_device(chip->dev);
348 spin_unlock(&driver_lock);
350 chip->data_buffer = kmalloc(TPM_BUFSIZE * sizeof(u8), GFP_KERNEL);
351 if (chip->data_buffer == NULL) {
353 put_device(chip->dev);
357 atomic_set(&chip->data_pending, 0);
359 file->private_data = chip;
363 spin_unlock(&driver_lock);
367 EXPORT_SYMBOL_GPL(tpm_open);
369 int tpm_release(struct inode *inode, struct file *file)
371 struct tpm_chip *chip = file->private_data;
373 spin_lock(&driver_lock);
374 file->private_data = NULL;
376 del_singleshot_timer_sync(&chip->user_read_timer);
377 atomic_set(&chip->data_pending, 0);
378 put_device(chip->dev);
379 kfree(chip->data_buffer);
380 spin_unlock(&driver_lock);
384 EXPORT_SYMBOL_GPL(tpm_release);
386 ssize_t tpm_write(struct file * file, const char __user * buf,
387 size_t size, loff_t * off)
389 struct tpm_chip *chip = file->private_data;
390 int in_size = size, out_size;
392 /* cannot perform a write until the read has cleared
393 either via tpm_read or a user_read_timer timeout */
394 while (atomic_read(&chip->data_pending) != 0)
397 down(&chip->buffer_mutex);
399 if (in_size > TPM_BUFSIZE)
400 in_size = TPM_BUFSIZE;
403 (chip->data_buffer, (void __user *) buf, in_size)) {
404 up(&chip->buffer_mutex);
408 /* atomic tpm command send and result receive */
409 out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE);
411 atomic_set(&chip->data_pending, out_size);
412 up(&chip->buffer_mutex);
414 /* Set a timeout by which the reader must come claim the result */
415 mod_timer(&chip->user_read_timer, jiffies + (60 * HZ));
420 EXPORT_SYMBOL_GPL(tpm_write);
422 ssize_t tpm_read(struct file * file, char __user * buf,
423 size_t size, loff_t * off)
425 struct tpm_chip *chip = file->private_data;
428 del_singleshot_timer_sync(&chip->user_read_timer);
429 ret_size = atomic_read(&chip->data_pending);
430 atomic_set(&chip->data_pending, 0);
431 if (ret_size > 0) { /* relay data */
435 down(&chip->buffer_mutex);
437 ((void __user *) buf, chip->data_buffer, ret_size))
439 up(&chip->buffer_mutex);
445 EXPORT_SYMBOL_GPL(tpm_read);
447 void tpm_remove_hardware(struct device *dev)
449 struct tpm_chip *chip = dev_get_drvdata(dev);
452 dev_err(dev, "No device data found\n");
456 spin_lock(&driver_lock);
458 list_del(&chip->list);
460 spin_unlock(&driver_lock);
462 dev_set_drvdata(dev, NULL);
463 misc_deregister(&chip->vendor->miscdev);
464 kfree(chip->vendor->miscdev.name);
466 sysfs_remove_group(&dev->kobj, chip->vendor->attr_group);
468 dev_mask[chip->dev_num / TPM_NUM_MASK_ENTRIES ] &= !(1 << (chip->dev_num % TPM_NUM_MASK_ENTRIES));
475 EXPORT_SYMBOL_GPL(tpm_remove_hardware);
477 static u8 savestate[] = {
478 0, 193, /* TPM_TAG_RQU_COMMAND */
479 0, 0, 0, 10, /* blob length (in bytes) */
480 0, 0, 0, 152 /* TPM_ORD_SaveState */
484 * We are about to suspend. Save the TPM state
485 * so that it can be restored.
487 int tpm_pm_suspend(struct device *dev, pm_message_t pm_state)
489 struct tpm_chip *chip = dev_get_drvdata(dev);
493 tpm_transmit(chip, savestate, sizeof(savestate));
497 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
500 * Resume from a power safe. The BIOS already restored
503 int tpm_pm_resume(struct device *dev)
505 struct tpm_chip *chip = dev_get_drvdata(dev);
513 EXPORT_SYMBOL_GPL(tpm_pm_resume);
516 * Called from tpm_<specific>.c probe function only for devices
517 * the driver has determined it should claim. Prior to calling
518 * this function the specific probe function has called pci_enable_device
519 * upon errant exit from this function specific probe function should call
522 int tpm_register_hardware(struct device *dev,
523 struct tpm_vendor_specific *entry)
525 #define DEVNAME_SIZE 7
528 struct tpm_chip *chip;
531 /* Driver specific per-device data */
532 chip = kmalloc(sizeof(*chip), GFP_KERNEL);
536 memset(chip, 0, sizeof(struct tpm_chip));
538 init_MUTEX(&chip->buffer_mutex);
539 init_MUTEX(&chip->tpm_mutex);
540 INIT_LIST_HEAD(&chip->list);
542 init_timer(&chip->user_read_timer);
543 chip->user_read_timer.function = user_reader_timeout;
544 chip->user_read_timer.data = (unsigned long) chip;
546 chip->vendor = entry;
550 for (i = 0; i < TPM_NUM_MASK_ENTRIES; i++)
551 for (j = 0; j < 8 * sizeof(int); j++)
552 if ((dev_mask[i] & (1 << j)) == 0) {
554 i * TPM_NUM_MASK_ENTRIES + j;
555 dev_mask[i] |= 1 << j;
556 goto dev_num_search_complete;
559 dev_num_search_complete:
560 if (chip->dev_num < 0) {
562 "No available tpm device numbers\n");
565 } else if (chip->dev_num == 0)
566 chip->vendor->miscdev.minor = TPM_MINOR;
568 chip->vendor->miscdev.minor = MISC_DYNAMIC_MINOR;
570 devname = kmalloc(DEVNAME_SIZE, GFP_KERNEL);
571 scnprintf(devname, DEVNAME_SIZE, "%s%d", "tpm", chip->dev_num);
572 chip->vendor->miscdev.name = devname;
574 chip->vendor->miscdev.dev = dev;
575 chip->dev = get_device(dev);
577 if (misc_register(&chip->vendor->miscdev)) {
579 "unable to misc_register %s, minor %d\n",
580 chip->vendor->miscdev.name,
581 chip->vendor->miscdev.minor);
584 dev_mask[i] &= !(1 << j);
588 spin_lock(&driver_lock);
590 dev_set_drvdata(dev, chip);
592 list_add(&chip->list, &tpm_chip_list);
594 spin_unlock(&driver_lock);
596 sysfs_create_group(&dev->kobj, chip->vendor->attr_group);
601 EXPORT_SYMBOL_GPL(tpm_register_hardware);
603 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
604 MODULE_DESCRIPTION("TPM Driver");
605 MODULE_VERSION("2.0");
606 MODULE_LICENSE("GPL");