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Merge branch 'master'
[deliverable/linux.git] / drivers / char / tpm / tpm.c
1 /*
2 * Copyright (C) 2004 IBM Corporation
3 *
4 * Authors:
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>
9 *
10 * Maintained by: <tpmdd_devel@lists.sourceforge.net>
11 *
12 * Device driver for TCG/TCPA TPM (trusted platform module).
13 * Specifications at www.trustedcomputinggroup.org
14 *
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
18 * License.
19 *
20 * Note, the TPM chip is not interrupt driven (only polling)
21 * and can have very long timeouts (minutes!). Hence the unusual
22 * calls to msleep.
23 *
24 */
25
26 #include <linux/sched.h>
27 #include <linux/poll.h>
28 #include <linux/spinlock.h>
29 #include "tpm.h"
30
31 enum tpm_const {
32 TPM_MINOR = 224, /* officially assigned */
33 TPM_BUFSIZE = 2048,
34 TPM_NUM_DEVICES = 256,
35 TPM_NUM_MASK_ENTRIES = TPM_NUM_DEVICES / (8 * sizeof(int))
36 };
37
38 static LIST_HEAD(tpm_chip_list);
39 static DEFINE_SPINLOCK(driver_lock);
40 static int dev_mask[TPM_NUM_MASK_ENTRIES];
41
42 static void user_reader_timeout(unsigned long ptr)
43 {
44 struct tpm_chip *chip = (struct tpm_chip *) ptr;
45
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);
50 }
51
52 /*
53 * Internal kernel interface to transmit TPM commands
54 */
55 static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
56 size_t bufsiz)
57 {
58 ssize_t rc;
59 u32 count;
60 unsigned long stop;
61
62 count = be32_to_cpu(*((__be32 *) (buf + 2)));
63
64 if (count == 0)
65 return -ENODATA;
66 if (count > bufsiz) {
67 dev_err(chip->dev,
68 "invalid count value %x %zx \n", count, bufsiz);
69 return -E2BIG;
70 }
71
72 down(&chip->tpm_mutex);
73
74 if ((rc = chip->vendor->send(chip, (u8 *) buf, count)) < 0) {
75 dev_err(chip->dev,
76 "tpm_transmit: tpm_send: error %zd\n", rc);
77 goto out;
78 }
79
80 stop = jiffies + 2 * 60 * HZ;
81 do {
82 u8 status = chip->vendor->status(chip);
83 if ((status & chip->vendor->req_complete_mask) ==
84 chip->vendor->req_complete_val) {
85 goto out_recv;
86 }
87
88 if ((status == chip->vendor->req_canceled)) {
89 dev_err(chip->dev, "Operation Canceled\n");
90 rc = -ECANCELED;
91 goto out;
92 }
93
94 msleep(TPM_TIMEOUT); /* CHECK */
95 rmb();
96 } while (time_before(jiffies, stop));
97
98
99 chip->vendor->cancel(chip);
100 dev_err(chip->dev, "Operation Timed out\n");
101 rc = -ETIME;
102 goto out;
103
104 out_recv:
105 rc = chip->vendor->recv(chip, (u8 *) buf, bufsiz);
106 if (rc < 0)
107 dev_err(chip->dev,
108 "tpm_transmit: tpm_recv: error %zd\n", rc);
109 out:
110 up(&chip->tpm_mutex);
111 return rc;
112 }
113
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 */
120 0, 0, 0, 5,
121 0, 0, 0, 4,
122 0, 0, 1, 1
123 };
124
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 */
131 };
132
133 ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
134 char *buf)
135 {
136 u8 data[READ_PCR_RESULT_SIZE];
137 ssize_t len;
138 int i, j, num_pcrs;
139 __be32 index;
140 char *str = buf;
141
142 struct tpm_chip *chip = dev_get_drvdata(dev);
143 if (chip == NULL)
144 return -ENODEV;
145
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))));
152 return 0;
153 }
154
155 num_pcrs = be32_to_cpu(*((__be32 *) (data + 14)));
156
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))),
166 i, num_pcrs);
167 goto out;
168 }
169 str += sprintf(str, "PCR-%02d: ", i);
170 for (j = 0; j < TPM_DIGEST_SIZE; j++)
171 str += sprintf(str, "%02X ", *(data + 10 + j));
172 str += sprintf(str, "\n");
173 }
174 out:
175 return str - buf;
176 }
177 EXPORT_SYMBOL_GPL(tpm_show_pcrs);
178
179 #define READ_PUBEK_RESULT_SIZE 314
180 static const u8 readpubek[] = {
181 0, 193, /* TPM_TAG_RQU_COMMAND */
182 0, 0, 0, 30, /* length */
183 0, 0, 0, 124, /* TPM_ORD_ReadPubek */
184 };
185
186 ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
187 char *buf)
188 {
189 u8 *data;
190 ssize_t len;
191 int i, rc;
192 char *str = buf;
193
194 struct tpm_chip *chip = dev_get_drvdata(dev);
195 if (chip == NULL)
196 return -ENODEV;
197
198 data = kzalloc(READ_PUBEK_RESULT_SIZE, GFP_KERNEL);
199 if (!data)
200 return -ENOMEM;
201
202 memcpy(data, readpubek, sizeof(readpubek));
203
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))));
209 rc = 0;
210 goto out;
211 }
212
213 /*
214 ignore header 10 bytes
215 algorithm 32 bits (1 == RSA )
216 encscheme 16 bits
217 sigscheme 16 bits
218 parameters (RSA 12->bytes: keybit, #primes, expbit)
219 keylenbytes 32 bits
220 256 byte modulus
221 ignore checksum 20 bytes
222 */
223
224 str +=
225 sprintf(str,
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))));
235
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");
240 }
241 rc = str - buf;
242 out:
243 kfree(data);
244 return rc;
245 }
246 EXPORT_SYMBOL_GPL(tpm_show_pubek);
247
248 #define CAP_VER_RESULT_SIZE 18
249 static const u8 cap_version[] = {
250 0, 193, /* TPM_TAG_RQU_COMMAND */
251 0, 0, 0, 18, /* length */
252 0, 0, 0, 101, /* TPM_ORD_GetCapability */
253 0, 0, 0, 6,
254 0, 0, 0, 0
255 };
256
257 #define CAP_MANUFACTURER_RESULT_SIZE 18
258 static const u8 cap_manufacturer[] = {
259 0, 193, /* TPM_TAG_RQU_COMMAND */
260 0, 0, 0, 22, /* length */
261 0, 0, 0, 101, /* TPM_ORD_GetCapability */
262 0, 0, 0, 5,
263 0, 0, 0, 4,
264 0, 0, 1, 3
265 };
266
267 ssize_t tpm_show_caps(struct device *dev, struct device_attribute *attr,
268 char *buf)
269 {
270 u8 data[sizeof(cap_manufacturer)];
271 ssize_t len;
272 char *str = buf;
273
274 struct tpm_chip *chip = dev_get_drvdata(dev);
275 if (chip == NULL)
276 return -ENODEV;
277
278 memcpy(data, cap_manufacturer, sizeof(cap_manufacturer));
279
280 if ((len = tpm_transmit(chip, data, sizeof(data))) <
281 CAP_MANUFACTURER_RESULT_SIZE)
282 return len;
283
284 str += sprintf(str, "Manufacturer: 0x%x\n",
285 be32_to_cpu(*((__be32 *) (data + 14))));
286
287 memcpy(data, cap_version, sizeof(cap_version));
288
289 if ((len = tpm_transmit(chip, data, sizeof(data))) <
290 CAP_VER_RESULT_SIZE)
291 return len;
292
293 str +=
294 sprintf(str, "TCG version: %d.%d\nFirmware version: %d.%d\n",
295 (int) data[14], (int) data[15], (int) data[16],
296 (int) data[17]);
297
298 return str - buf;
299 }
300 EXPORT_SYMBOL_GPL(tpm_show_caps);
301
302 ssize_t tpm_store_cancel(struct device *dev, struct device_attribute *attr,
303 const char *buf, size_t count)
304 {
305 struct tpm_chip *chip = dev_get_drvdata(dev);
306 if (chip == NULL)
307 return 0;
308
309 chip->vendor->cancel(chip);
310 return count;
311 }
312 EXPORT_SYMBOL_GPL(tpm_store_cancel);
313
314 /*
315 * Device file system interface to the TPM
316 */
317 int tpm_open(struct inode *inode, struct file *file)
318 {
319 int rc = 0, minor = iminor(inode);
320 struct tpm_chip *chip = NULL, *pos;
321
322 spin_lock(&driver_lock);
323
324 list_for_each_entry(pos, &tpm_chip_list, list) {
325 if (pos->vendor->miscdev.minor == minor) {
326 chip = pos;
327 break;
328 }
329 }
330
331 if (chip == NULL) {
332 rc = -ENODEV;
333 goto err_out;
334 }
335
336 if (chip->num_opens) {
337 dev_dbg(chip->dev, "Another process owns this TPM\n");
338 rc = -EBUSY;
339 goto err_out;
340 }
341
342 chip->num_opens++;
343 get_device(chip->dev);
344
345 spin_unlock(&driver_lock);
346
347 chip->data_buffer = kmalloc(TPM_BUFSIZE * sizeof(u8), GFP_KERNEL);
348 if (chip->data_buffer == NULL) {
349 chip->num_opens--;
350 put_device(chip->dev);
351 return -ENOMEM;
352 }
353
354 atomic_set(&chip->data_pending, 0);
355
356 file->private_data = chip;
357 return 0;
358
359 err_out:
360 spin_unlock(&driver_lock);
361 return rc;
362 }
363 EXPORT_SYMBOL_GPL(tpm_open);
364
365 int tpm_release(struct inode *inode, struct file *file)
366 {
367 struct tpm_chip *chip = file->private_data;
368
369 spin_lock(&driver_lock);
370 file->private_data = NULL;
371 chip->num_opens--;
372 del_singleshot_timer_sync(&chip->user_read_timer);
373 atomic_set(&chip->data_pending, 0);
374 put_device(chip->dev);
375 kfree(chip->data_buffer);
376 spin_unlock(&driver_lock);
377 return 0;
378 }
379 EXPORT_SYMBOL_GPL(tpm_release);
380
381 ssize_t tpm_write(struct file *file, const char __user *buf,
382 size_t size, loff_t * off)
383 {
384 struct tpm_chip *chip = file->private_data;
385 int in_size = size, out_size;
386
387 /* cannot perform a write until the read has cleared
388 either via tpm_read or a user_read_timer timeout */
389 while (atomic_read(&chip->data_pending) != 0)
390 msleep(TPM_TIMEOUT);
391
392 down(&chip->buffer_mutex);
393
394 if (in_size > TPM_BUFSIZE)
395 in_size = TPM_BUFSIZE;
396
397 if (copy_from_user
398 (chip->data_buffer, (void __user *) buf, in_size)) {
399 up(&chip->buffer_mutex);
400 return -EFAULT;
401 }
402
403 /* atomic tpm command send and result receive */
404 out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE);
405
406 atomic_set(&chip->data_pending, out_size);
407 up(&chip->buffer_mutex);
408
409 /* Set a timeout by which the reader must come claim the result */
410 mod_timer(&chip->user_read_timer, jiffies + (60 * HZ));
411
412 return in_size;
413 }
414
415 EXPORT_SYMBOL_GPL(tpm_write);
416
417 ssize_t tpm_read(struct file * file, char __user *buf,
418 size_t size, loff_t * off)
419 {
420 struct tpm_chip *chip = file->private_data;
421 int ret_size;
422
423 del_singleshot_timer_sync(&chip->user_read_timer);
424 ret_size = atomic_read(&chip->data_pending);
425 atomic_set(&chip->data_pending, 0);
426 if (ret_size > 0) { /* relay data */
427 if (size < ret_size)
428 ret_size = size;
429
430 down(&chip->buffer_mutex);
431 if (copy_to_user
432 ((void __user *) buf, chip->data_buffer, ret_size))
433 ret_size = -EFAULT;
434 up(&chip->buffer_mutex);
435 }
436
437 return ret_size;
438 }
439 EXPORT_SYMBOL_GPL(tpm_read);
440
441 void tpm_remove_hardware(struct device *dev)
442 {
443 struct tpm_chip *chip = dev_get_drvdata(dev);
444
445 if (chip == NULL) {
446 dev_err(dev, "No device data found\n");
447 return;
448 }
449
450 spin_lock(&driver_lock);
451
452 list_del(&chip->list);
453
454 spin_unlock(&driver_lock);
455
456 dev_set_drvdata(dev, NULL);
457 misc_deregister(&chip->vendor->miscdev);
458 kfree(chip->vendor->miscdev.name);
459
460 sysfs_remove_group(&dev->kobj, chip->vendor->attr_group);
461
462 dev_mask[chip->dev_num / TPM_NUM_MASK_ENTRIES ] &=
463 !(1 << (chip->dev_num % TPM_NUM_MASK_ENTRIES));
464
465 kfree(chip);
466
467 put_device(dev);
468 }
469 EXPORT_SYMBOL_GPL(tpm_remove_hardware);
470
471 static u8 savestate[] = {
472 0, 193, /* TPM_TAG_RQU_COMMAND */
473 0, 0, 0, 10, /* blob length (in bytes) */
474 0, 0, 0, 152 /* TPM_ORD_SaveState */
475 };
476
477 /*
478 * We are about to suspend. Save the TPM state
479 * so that it can be restored.
480 */
481 int tpm_pm_suspend(struct device *dev, pm_message_t pm_state)
482 {
483 struct tpm_chip *chip = dev_get_drvdata(dev);
484 if (chip == NULL)
485 return -ENODEV;
486
487 tpm_transmit(chip, savestate, sizeof(savestate));
488 return 0;
489 }
490 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
491
492 /*
493 * Resume from a power safe. The BIOS already restored
494 * the TPM state.
495 */
496 int tpm_pm_resume(struct device *dev)
497 {
498 struct tpm_chip *chip = dev_get_drvdata(dev);
499
500 if (chip == NULL)
501 return -ENODEV;
502
503 return 0;
504 }
505 EXPORT_SYMBOL_GPL(tpm_pm_resume);
506
507 /*
508 * Called from tpm_<specific>.c probe function only for devices
509 * the driver has determined it should claim. Prior to calling
510 * this function the specific probe function has called pci_enable_device
511 * upon errant exit from this function specific probe function should call
512 * pci_disable_device
513 */
514 int tpm_register_hardware(struct device *dev, struct tpm_vendor_specific *entry)
515 {
516 #define DEVNAME_SIZE 7
517
518 char *devname;
519 struct tpm_chip *chip;
520 int i, j;
521
522 /* Driver specific per-device data */
523 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
524 if (chip == NULL)
525 return -ENOMEM;
526
527 init_MUTEX(&chip->buffer_mutex);
528 init_MUTEX(&chip->tpm_mutex);
529 INIT_LIST_HEAD(&chip->list);
530
531 init_timer(&chip->user_read_timer);
532 chip->user_read_timer.function = user_reader_timeout;
533 chip->user_read_timer.data = (unsigned long) chip;
534
535 chip->vendor = entry;
536
537 chip->dev_num = -1;
538
539 for (i = 0; i < TPM_NUM_MASK_ENTRIES; i++)
540 for (j = 0; j < 8 * sizeof(int); j++)
541 if ((dev_mask[i] & (1 << j)) == 0) {
542 chip->dev_num =
543 i * TPM_NUM_MASK_ENTRIES + j;
544 dev_mask[i] |= 1 << j;
545 goto dev_num_search_complete;
546 }
547
548 dev_num_search_complete:
549 if (chip->dev_num < 0) {
550 dev_err(dev, "No available tpm device numbers\n");
551 kfree(chip);
552 return -ENODEV;
553 } else if (chip->dev_num == 0)
554 chip->vendor->miscdev.minor = TPM_MINOR;
555 else
556 chip->vendor->miscdev.minor = MISC_DYNAMIC_MINOR;
557
558 devname = kmalloc(DEVNAME_SIZE, GFP_KERNEL);
559 scnprintf(devname, DEVNAME_SIZE, "%s%d", "tpm", chip->dev_num);
560 chip->vendor->miscdev.name = devname;
561
562 chip->vendor->miscdev.dev = dev;
563 chip->dev = get_device(dev);
564
565 if (misc_register(&chip->vendor->miscdev)) {
566 dev_err(chip->dev,
567 "unable to misc_register %s, minor %d\n",
568 chip->vendor->miscdev.name,
569 chip->vendor->miscdev.minor);
570 put_device(dev);
571 kfree(chip);
572 dev_mask[i] &= !(1 << j);
573 return -ENODEV;
574 }
575
576 spin_lock(&driver_lock);
577
578 dev_set_drvdata(dev, chip);
579
580 list_add(&chip->list, &tpm_chip_list);
581
582 spin_unlock(&driver_lock);
583
584 sysfs_create_group(&dev->kobj, chip->vendor->attr_group);
585
586 return 0;
587 }
588 EXPORT_SYMBOL_GPL(tpm_register_hardware);
589
590 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
591 MODULE_DESCRIPTION("TPM Driver");
592 MODULE_VERSION("2.0");
593 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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