[PATCH] tpm: spacing cleanups
[linux-2.6] / 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         schedule_work(&chip->work);
47 }
48
49 static void timeout_work(void *ptr)
50 {
51         struct tpm_chip *chip = ptr;
52
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);
57 }
58
59 /*
60  * Internal kernel interface to transmit TPM commands
61  */
62 static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
63                             size_t bufsiz)
64 {
65         ssize_t rc;
66         u32 count;
67         unsigned long stop;
68
69         count = be32_to_cpu(*((__be32 *) (buf + 2)));
70
71         if (count == 0)
72                 return -ENODATA;
73         if (count > bufsiz) {
74                 dev_err(chip->dev,
75                         "invalid count value %x %zx \n", count, bufsiz);
76                 return -E2BIG;
77         }
78
79         down(&chip->tpm_mutex);
80
81         if ((rc = chip->vendor->send(chip, (u8 *) buf, count)) < 0) {
82                 dev_err(chip->dev,
83                         "tpm_transmit: tpm_send: error %zd\n", rc);
84                 goto out;
85         }
86
87         stop = jiffies + 2 * 60 * HZ;
88         do {
89                 u8 status = chip->vendor->status(chip);
90                 if ((status & chip->vendor->req_complete_mask) ==
91                     chip->vendor->req_complete_val) {
92                         goto out_recv;
93                 }
94
95                 if ((status == chip->vendor->req_canceled)) {
96                         dev_err(chip->dev, "Operation Canceled\n");
97                         rc = -ECANCELED;
98                         goto out;
99                 }
100
101                 msleep(TPM_TIMEOUT);    /* CHECK */
102                 rmb();
103         } while (time_before(jiffies, stop));
104
105
106         chip->vendor->cancel(chip);
107         dev_err(chip->dev, "Operation Timed out\n");
108         rc = -ETIME;
109         goto out;
110
111 out_recv:
112         rc = chip->vendor->recv(chip, (u8 *) buf, bufsiz);
113         if (rc < 0)
114                 dev_err(chip->dev,
115                         "tpm_transmit: tpm_recv: error %zd\n", rc);
116 out:
117         up(&chip->tpm_mutex);
118         return rc;
119 }
120
121 #define TPM_DIGEST_SIZE 20
122 #define CAP_PCR_RESULT_SIZE 18
123 static const u8 cap_pcr[] = {
124         0, 193,                 /* TPM_TAG_RQU_COMMAND */
125         0, 0, 0, 22,            /* length */
126         0, 0, 0, 101,           /* TPM_ORD_GetCapability */
127         0, 0, 0, 5,
128         0, 0, 0, 4,
129         0, 0, 1, 1
130 };
131
132 #define READ_PCR_RESULT_SIZE 30
133 static const u8 pcrread[] = {
134         0, 193,                 /* TPM_TAG_RQU_COMMAND */
135         0, 0, 0, 14,            /* length */
136         0, 0, 0, 21,            /* TPM_ORD_PcrRead */
137         0, 0, 0, 0              /* PCR index */
138 };
139
140 ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
141                       char *buf)
142 {
143         u8 data[READ_PCR_RESULT_SIZE];
144         ssize_t len;
145         int i, j, num_pcrs;
146         __be32 index;
147         char *str = buf;
148
149         struct tpm_chip *chip = dev_get_drvdata(dev);
150         if (chip == NULL)
151                 return -ENODEV;
152
153         memcpy(data, cap_pcr, sizeof(cap_pcr));
154         if ((len = tpm_transmit(chip, data, sizeof(data)))
155             < CAP_PCR_RESULT_SIZE) {
156                 dev_dbg(chip->dev, "A TPM error (%d) occurred "
157                                 "attempting to determine the number of PCRS\n",
158                         be32_to_cpu(*((__be32 *) (data + 6))));
159                 return 0;
160         }
161
162         num_pcrs = be32_to_cpu(*((__be32 *) (data + 14)));
163
164         for (i = 0; i < num_pcrs; i++) {
165                 memcpy(data, pcrread, sizeof(pcrread));
166                 index = cpu_to_be32(i);
167                 memcpy(data + 10, &index, 4);
168                 if ((len = tpm_transmit(chip, data, sizeof(data)))
169                     < READ_PCR_RESULT_SIZE){
170                         dev_dbg(chip->dev, "A TPM error (%d) occurred"
171                                 " attempting to read PCR %d of %d\n",
172                                 be32_to_cpu(*((__be32 *) (data + 6))),
173                                 i, num_pcrs);
174                         goto out;
175                 }
176                 str += sprintf(str, "PCR-%02d: ", i);
177                 for (j = 0; j < TPM_DIGEST_SIZE; j++)
178                         str += sprintf(str, "%02X ", *(data + 10 + j));
179                 str += sprintf(str, "\n");
180         }
181 out:
182         return str - buf;
183 }
184 EXPORT_SYMBOL_GPL(tpm_show_pcrs);
185
186 #define  READ_PUBEK_RESULT_SIZE 314
187 static const u8 readpubek[] = {
188         0, 193,                 /* TPM_TAG_RQU_COMMAND */
189         0, 0, 0, 30,            /* length */
190         0, 0, 0, 124,           /* TPM_ORD_ReadPubek */
191 };
192
193 ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
194                        char *buf)
195 {
196         u8 *data;
197         ssize_t len;
198         int i, rc;
199         char *str = buf;
200
201         struct tpm_chip *chip = dev_get_drvdata(dev);
202         if (chip == NULL)
203                 return -ENODEV;
204
205         data = kzalloc(READ_PUBEK_RESULT_SIZE, GFP_KERNEL);
206         if (!data)
207                 return -ENOMEM;
208
209         memcpy(data, readpubek, sizeof(readpubek));
210
211         if ((len = tpm_transmit(chip, data, READ_PUBEK_RESULT_SIZE)) <
212             READ_PUBEK_RESULT_SIZE) {
213                 dev_dbg(chip->dev, "A TPM error (%d) occurred "
214                                 "attempting to read the PUBEK\n",
215                             be32_to_cpu(*((__be32 *) (data + 6))));
216                 rc = 0;
217                 goto out;
218         }
219
220         /* 
221            ignore header 10 bytes
222            algorithm 32 bits (1 == RSA )
223            encscheme 16 bits
224            sigscheme 16 bits
225            parameters (RSA 12->bytes: keybit, #primes, expbit)  
226            keylenbytes 32 bits
227            256 byte modulus
228            ignore checksum 20 bytes
229          */
230
231         str +=
232             sprintf(str,
233                     "Algorithm: %02X %02X %02X %02X\nEncscheme: %02X %02X\n"
234                     "Sigscheme: %02X %02X\nParameters: %02X %02X %02X %02X"
235                     " %02X %02X %02X %02X %02X %02X %02X %02X\n"
236                     "Modulus length: %d\nModulus: \n",
237                     data[10], data[11], data[12], data[13], data[14],
238                     data[15], data[16], data[17], data[22], data[23],
239                     data[24], data[25], data[26], data[27], data[28],
240                     data[29], data[30], data[31], data[32], data[33],
241                     be32_to_cpu(*((__be32 *) (data + 34))));
242
243         for (i = 0; i < 256; i++) {
244                 str += sprintf(str, "%02X ", data[i + 38]);
245                 if ((i + 1) % 16 == 0)
246                         str += sprintf(str, "\n");
247         }
248         rc = str - buf;
249 out:
250         kfree(data);
251         return rc;
252 }
253 EXPORT_SYMBOL_GPL(tpm_show_pubek);
254
255 #define CAP_VER_RESULT_SIZE 18
256 static const u8 cap_version[] = {
257         0, 193,                 /* TPM_TAG_RQU_COMMAND */
258         0, 0, 0, 18,            /* length */
259         0, 0, 0, 101,           /* TPM_ORD_GetCapability */
260         0, 0, 0, 6,
261         0, 0, 0, 0
262 };
263
264 #define CAP_MANUFACTURER_RESULT_SIZE 18
265 static const u8 cap_manufacturer[] = {
266         0, 193,                 /* TPM_TAG_RQU_COMMAND */
267         0, 0, 0, 22,            /* length */
268         0, 0, 0, 101,           /* TPM_ORD_GetCapability */
269         0, 0, 0, 5,
270         0, 0, 0, 4,
271         0, 0, 1, 3
272 };
273
274 ssize_t tpm_show_caps(struct device *dev, struct device_attribute *attr,
275                       char *buf)
276 {
277         u8 data[sizeof(cap_manufacturer)];
278         ssize_t len;
279         char *str = buf;
280
281         struct tpm_chip *chip = dev_get_drvdata(dev);
282         if (chip == NULL)
283                 return -ENODEV;
284
285         memcpy(data, cap_manufacturer, sizeof(cap_manufacturer));
286
287         if ((len = tpm_transmit(chip, data, sizeof(data))) <
288             CAP_MANUFACTURER_RESULT_SIZE)
289                 return len;
290
291         str += sprintf(str, "Manufacturer: 0x%x\n",
292                        be32_to_cpu(*((__be32 *) (data + 14))));
293
294         memcpy(data, cap_version, sizeof(cap_version));
295
296         if ((len = tpm_transmit(chip, data, sizeof(data))) <
297             CAP_VER_RESULT_SIZE)
298                 return len;
299
300         str +=
301             sprintf(str, "TCG version: %d.%d\nFirmware version: %d.%d\n",
302                     (int) data[14], (int) data[15], (int) data[16],
303                     (int) data[17]);
304
305         return str - buf;
306 }
307 EXPORT_SYMBOL_GPL(tpm_show_caps);
308
309 ssize_t tpm_store_cancel(struct device *dev, struct device_attribute *attr,
310                         const char *buf, size_t count)
311 {
312         struct tpm_chip *chip = dev_get_drvdata(dev);
313         if (chip == NULL)
314                 return 0;
315
316         chip->vendor->cancel(chip);
317         return count;
318 }
319 EXPORT_SYMBOL_GPL(tpm_store_cancel);
320
321 /*
322  * Device file system interface to the TPM
323  */
324 int tpm_open(struct inode *inode, struct file *file)
325 {
326         int rc = 0, minor = iminor(inode);
327         struct tpm_chip *chip = NULL, *pos;
328
329         spin_lock(&driver_lock);
330
331         list_for_each_entry(pos, &tpm_chip_list, list) {
332                 if (pos->vendor->miscdev.minor == minor) {
333                         chip = pos;
334                         break;
335                 }
336         }
337
338         if (chip == NULL) {
339                 rc = -ENODEV;
340                 goto err_out;
341         }
342
343         if (chip->num_opens) {
344                 dev_dbg(chip->dev, "Another process owns this TPM\n");
345                 rc = -EBUSY;
346                 goto err_out;
347         }
348
349         chip->num_opens++;
350         get_device(chip->dev);
351
352         spin_unlock(&driver_lock);
353
354         chip->data_buffer = kmalloc(TPM_BUFSIZE * sizeof(u8), GFP_KERNEL);
355         if (chip->data_buffer == NULL) {
356                 chip->num_opens--;
357                 put_device(chip->dev);
358                 return -ENOMEM;
359         }
360
361         atomic_set(&chip->data_pending, 0);
362
363         file->private_data = chip;
364         return 0;
365
366 err_out:
367         spin_unlock(&driver_lock);
368         return rc;
369 }
370 EXPORT_SYMBOL_GPL(tpm_open);
371
372 int tpm_release(struct inode *inode, struct file *file)
373 {
374         struct tpm_chip *chip = file->private_data;
375
376         spin_lock(&driver_lock);
377         file->private_data = NULL;
378         chip->num_opens--;
379         del_singleshot_timer_sync(&chip->user_read_timer);
380         flush_scheduled_work();
381         atomic_set(&chip->data_pending, 0);
382         put_device(chip->dev);
383         kfree(chip->data_buffer);
384         spin_unlock(&driver_lock);
385         return 0;
386 }
387 EXPORT_SYMBOL_GPL(tpm_release);
388
389 ssize_t tpm_write(struct file *file, const char __user *buf,
390                   size_t size, loff_t *off)
391 {
392         struct tpm_chip *chip = file->private_data;
393         int in_size = size, out_size;
394
395         /* cannot perform a write until the read has cleared
396            either via tpm_read or a user_read_timer timeout */
397         while (atomic_read(&chip->data_pending) != 0)
398                 msleep(TPM_TIMEOUT);
399
400         down(&chip->buffer_mutex);
401
402         if (in_size > TPM_BUFSIZE)
403                 in_size = TPM_BUFSIZE;
404
405         if (copy_from_user
406             (chip->data_buffer, (void __user *) buf, in_size)) {
407                 up(&chip->buffer_mutex);
408                 return -EFAULT;
409         }
410
411         /* atomic tpm command send and result receive */
412         out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE);
413
414         atomic_set(&chip->data_pending, out_size);
415         up(&chip->buffer_mutex);
416
417         /* Set a timeout by which the reader must come claim the result */
418         mod_timer(&chip->user_read_timer, jiffies + (60 * HZ));
419
420         return in_size;
421 }
422 EXPORT_SYMBOL_GPL(tpm_write);
423
424 ssize_t tpm_read(struct file *file, char __user *buf,
425                  size_t size, loff_t *off)
426 {
427         struct tpm_chip *chip = file->private_data;
428         int ret_size;
429
430         del_singleshot_timer_sync(&chip->user_read_timer);
431         flush_scheduled_work();
432         ret_size = atomic_read(&chip->data_pending);
433         atomic_set(&chip->data_pending, 0);
434         if (ret_size > 0) {     /* relay data */
435                 if (size < ret_size)
436                         ret_size = size;
437
438                 down(&chip->buffer_mutex);
439                 if (copy_to_user(buf, chip->data_buffer, ret_size))
440                         ret_size = -EFAULT;
441                 up(&chip->buffer_mutex);
442         }
443
444         return ret_size;
445 }
446 EXPORT_SYMBOL_GPL(tpm_read);
447
448 void tpm_remove_hardware(struct device *dev)
449 {
450         struct tpm_chip *chip = dev_get_drvdata(dev);
451
452         if (chip == NULL) {
453                 dev_err(dev, "No device data found\n");
454                 return;
455         }
456
457         spin_lock(&driver_lock);
458
459         list_del(&chip->list);
460
461         spin_unlock(&driver_lock);
462
463         dev_set_drvdata(dev, NULL);
464         misc_deregister(&chip->vendor->miscdev);
465         kfree(chip->vendor->miscdev.name);
466
467         sysfs_remove_group(&dev->kobj, chip->vendor->attr_group);
468         tpm_bios_log_teardown(chip->bios_dir);
469
470         dev_mask[chip->dev_num / TPM_NUM_MASK_ENTRIES ] &=
471                 ~(1 << (chip->dev_num % TPM_NUM_MASK_ENTRIES));
472
473         kfree(chip);
474
475         put_device(dev);
476 }
477 EXPORT_SYMBOL_GPL(tpm_remove_hardware);
478
479 static u8 savestate[] = {
480         0, 193,                 /* TPM_TAG_RQU_COMMAND */
481         0, 0, 0, 10,            /* blob length (in bytes) */
482         0, 0, 0, 152            /* TPM_ORD_SaveState */
483 };
484
485 /*
486  * We are about to suspend. Save the TPM state
487  * so that it can be restored.
488  */
489 int tpm_pm_suspend(struct device *dev, pm_message_t pm_state)
490 {
491         struct tpm_chip *chip = dev_get_drvdata(dev);
492         if (chip == NULL)
493                 return -ENODEV;
494
495         tpm_transmit(chip, savestate, sizeof(savestate));
496         return 0;
497 }
498 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
499
500 /*
501  * Resume from a power safe. The BIOS already restored
502  * the TPM state.
503  */
504 int tpm_pm_resume(struct device *dev)
505 {
506         struct tpm_chip *chip = dev_get_drvdata(dev);
507
508         if (chip == NULL)
509                 return -ENODEV;
510
511         return 0;
512 }
513 EXPORT_SYMBOL_GPL(tpm_pm_resume);
514
515 /*
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
520  * pci_disable_device
521  */
522 int tpm_register_hardware(struct device *dev, struct tpm_vendor_specific *entry)
523 {
524 #define DEVNAME_SIZE 7
525
526         char *devname;
527         struct tpm_chip *chip;
528         int i, j;
529
530         /* Driver specific per-device data */
531         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
532         if (chip == NULL)
533                 return -ENOMEM;
534
535         init_MUTEX(&chip->buffer_mutex);
536         init_MUTEX(&chip->tpm_mutex);
537         INIT_LIST_HEAD(&chip->list);
538
539         INIT_WORK(&chip->work, timeout_work, chip);
540
541         init_timer(&chip->user_read_timer);
542         chip->user_read_timer.function = user_reader_timeout;
543         chip->user_read_timer.data = (unsigned long) chip;
544
545         chip->vendor = entry;
546
547         chip->dev_num = -1;
548
549         for (i = 0; i < TPM_NUM_MASK_ENTRIES; i++)
550                 for (j = 0; j < 8 * sizeof(int); j++)
551                         if ((dev_mask[i] & (1 << j)) == 0) {
552                                 chip->dev_num =
553                                     i * TPM_NUM_MASK_ENTRIES + j;
554                                 dev_mask[i] |= 1 << j;
555                                 goto dev_num_search_complete;
556                         }
557
558 dev_num_search_complete:
559         if (chip->dev_num < 0) {
560                 dev_err(dev, "No available tpm device numbers\n");
561                 kfree(chip);
562                 return -ENODEV;
563         } else if (chip->dev_num == 0)
564                 chip->vendor->miscdev.minor = TPM_MINOR;
565         else
566                 chip->vendor->miscdev.minor = MISC_DYNAMIC_MINOR;
567
568         devname = kmalloc(DEVNAME_SIZE, GFP_KERNEL);
569         scnprintf(devname, DEVNAME_SIZE, "%s%d", "tpm", chip->dev_num);
570         chip->vendor->miscdev.name = devname;
571
572         chip->vendor->miscdev.dev = dev;
573         chip->dev = get_device(dev);
574
575         if (misc_register(&chip->vendor->miscdev)) {
576                 dev_err(chip->dev,
577                         "unable to misc_register %s, minor %d\n",
578                         chip->vendor->miscdev.name,
579                         chip->vendor->miscdev.minor);
580                 put_device(dev);
581                 kfree(chip);
582                 dev_mask[i] &= !(1 << j);
583                 return -ENODEV;
584         }
585
586         spin_lock(&driver_lock);
587
588         dev_set_drvdata(dev, chip);
589
590         list_add(&chip->list, &tpm_chip_list);
591
592         spin_unlock(&driver_lock);
593
594         sysfs_create_group(&dev->kobj, chip->vendor->attr_group);
595
596         chip->bios_dir = tpm_bios_log_setup(devname);
597
598         return 0;
599 }
600 EXPORT_SYMBOL_GPL(tpm_register_hardware);
601
602 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
603 MODULE_DESCRIPTION("TPM Driver");
604 MODULE_VERSION("2.0");
605 MODULE_LICENSE("GPL");