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afb5abc2 JS |
1 | /* |
2 | * Copyright (C) 2004 IBM Corporation | |
3 | * Copyright (C) 2014 Intel Corporation | |
4 | * | |
5 | * Authors: | |
6 | * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> | |
7 | * Leendert van Doorn <leendert@watson.ibm.com> | |
8 | * Dave Safford <safford@watson.ibm.com> | |
9 | * Reiner Sailer <sailer@watson.ibm.com> | |
10 | * Kylene Hall <kjhall@us.ibm.com> | |
11 | * | |
12 | * Maintained by: <tpmdd-devel@lists.sourceforge.net> | |
13 | * | |
14 | * TPM chip management routines. | |
15 | * | |
16 | * This program is free software; you can redistribute it and/or | |
17 | * modify it under the terms of the GNU General Public License as | |
18 | * published by the Free Software Foundation, version 2 of the | |
19 | * License. | |
20 | * | |
21 | */ | |
22 | ||
23 | #include <linux/poll.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/mutex.h> | |
26 | #include <linux/spinlock.h> | |
27 | #include <linux/freezer.h> | |
313d21ee | 28 | #include <linux/major.h> |
afb5abc2 JS |
29 | #include "tpm.h" |
30 | #include "tpm_eventlog.h" | |
31 | ||
32 | static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES); | |
33 | static LIST_HEAD(tpm_chip_list); | |
34 | static DEFINE_SPINLOCK(driver_lock); | |
35 | ||
313d21ee JS |
36 | struct class *tpm_class; |
37 | dev_t tpm_devt; | |
38 | ||
afb5abc2 JS |
39 | /* |
40 | * tpm_chip_find_get - return tpm_chip for a given chip number | |
41 | * @chip_num the device number for the chip | |
42 | */ | |
43 | struct tpm_chip *tpm_chip_find_get(int chip_num) | |
44 | { | |
45 | struct tpm_chip *pos, *chip = NULL; | |
46 | ||
47 | rcu_read_lock(); | |
48 | list_for_each_entry_rcu(pos, &tpm_chip_list, list) { | |
49 | if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num) | |
50 | continue; | |
51 | ||
71ed848f | 52 | if (try_module_get(pos->pdev->driver->owner)) { |
afb5abc2 JS |
53 | chip = pos; |
54 | break; | |
55 | } | |
56 | } | |
57 | rcu_read_unlock(); | |
58 | return chip; | |
59 | } | |
60 | ||
61 | /** | |
313d21ee JS |
62 | * tpm_dev_release() - free chip memory and the device number |
63 | * @dev: the character device for the TPM chip | |
afb5abc2 | 64 | * |
313d21ee | 65 | * This is used as the release function for the character device. |
afb5abc2 | 66 | */ |
313d21ee | 67 | static void tpm_dev_release(struct device *dev) |
afb5abc2 | 68 | { |
313d21ee | 69 | struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev); |
afb5abc2 JS |
70 | |
71 | spin_lock(&driver_lock); | |
72 | clear_bit(chip->dev_num, dev_mask); | |
73 | spin_unlock(&driver_lock); | |
74 | kfree(chip); | |
75 | } | |
76 | ||
77 | /** | |
78 | * tpmm_chip_alloc() - allocate a new struct tpm_chip instance | |
79 | * @dev: device to which the chip is associated | |
80 | * @ops: struct tpm_class_ops instance | |
81 | * | |
82 | * Allocates a new struct tpm_chip instance and assigns a free | |
83 | * device number for it. Caller does not have to worry about | |
84 | * freeing the allocated resources. When the devices is removed | |
85 | * devres calls tpmm_chip_remove() to do the job. | |
86 | */ | |
87 | struct tpm_chip *tpmm_chip_alloc(struct device *dev, | |
88 | const struct tpm_class_ops *ops) | |
89 | { | |
90 | struct tpm_chip *chip; | |
91 | ||
92 | chip = kzalloc(sizeof(*chip), GFP_KERNEL); | |
93 | if (chip == NULL) | |
94 | return ERR_PTR(-ENOMEM); | |
95 | ||
96 | mutex_init(&chip->tpm_mutex); | |
97 | INIT_LIST_HEAD(&chip->list); | |
98 | ||
99 | chip->ops = ops; | |
100 | ||
101 | spin_lock(&driver_lock); | |
102 | chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES); | |
103 | spin_unlock(&driver_lock); | |
104 | ||
105 | if (chip->dev_num >= TPM_NUM_DEVICES) { | |
106 | dev_err(dev, "No available tpm device numbers\n"); | |
107 | kfree(chip); | |
108 | return ERR_PTR(-ENOMEM); | |
109 | } | |
110 | ||
111 | set_bit(chip->dev_num, dev_mask); | |
112 | ||
113 | scnprintf(chip->devname, sizeof(chip->devname), "tpm%d", chip->dev_num); | |
114 | ||
71ed848f | 115 | chip->pdev = dev; |
313d21ee | 116 | |
afb5abc2 JS |
117 | dev_set_drvdata(dev, chip); |
118 | ||
313d21ee JS |
119 | chip->dev.class = tpm_class; |
120 | chip->dev.release = tpm_dev_release; | |
121 | chip->dev.parent = chip->pdev; | |
122 | ||
123 | if (chip->dev_num == 0) | |
124 | chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR); | |
125 | else | |
126 | chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num); | |
127 | ||
743410a0 | 128 | dev_set_name(&chip->dev, "%s", chip->devname); |
313d21ee JS |
129 | |
130 | device_initialize(&chip->dev); | |
131 | ||
132 | chip->cdev.owner = chip->pdev->driver->owner; | |
133 | cdev_init(&chip->cdev, &tpm_fops); | |
134 | ||
afb5abc2 JS |
135 | return chip; |
136 | } | |
137 | EXPORT_SYMBOL_GPL(tpmm_chip_alloc); | |
138 | ||
313d21ee JS |
139 | static int tpm_dev_add_device(struct tpm_chip *chip) |
140 | { | |
141 | int rc; | |
142 | ||
19913b6d | 143 | rc = cdev_add(&chip->cdev, chip->dev.devt, 1); |
313d21ee JS |
144 | if (rc) { |
145 | dev_err(&chip->dev, | |
19913b6d | 146 | "unable to cdev_add() %s, major %d, minor %d, err=%d\n", |
313d21ee JS |
147 | chip->devname, MAJOR(chip->dev.devt), |
148 | MINOR(chip->dev.devt), rc); | |
149 | ||
19913b6d | 150 | device_unregister(&chip->dev); |
313d21ee JS |
151 | return rc; |
152 | } | |
153 | ||
19913b6d | 154 | rc = device_add(&chip->dev); |
313d21ee JS |
155 | if (rc) { |
156 | dev_err(&chip->dev, | |
19913b6d | 157 | "unable to device_register() %s, major %d, minor %d, err=%d\n", |
313d21ee JS |
158 | chip->devname, MAJOR(chip->dev.devt), |
159 | MINOR(chip->dev.devt), rc); | |
160 | ||
313d21ee JS |
161 | return rc; |
162 | } | |
163 | ||
164 | return rc; | |
165 | } | |
166 | ||
167 | static void tpm_dev_del_device(struct tpm_chip *chip) | |
168 | { | |
169 | cdev_del(&chip->cdev); | |
170 | device_unregister(&chip->dev); | |
171 | } | |
172 | ||
afb5abc2 | 173 | /* |
313d21ee | 174 | * tpm_chip_register() - create a character device for the TPM chip |
afb5abc2 JS |
175 | * @chip: TPM chip to use. |
176 | * | |
19913b6d JS |
177 | * Creates a character device for the TPM chip and adds sysfs attributes for |
178 | * the device. As the last step this function adds the chip to the list of TPM | |
179 | * chips available for in-kernel use. | |
afb5abc2 | 180 | * |
19913b6d JS |
181 | * This function should be only called after the chip initialization is |
182 | * complete. | |
afb5abc2 JS |
183 | */ |
184 | int tpm_chip_register(struct tpm_chip *chip) | |
185 | { | |
186 | int rc; | |
187 | ||
7a1d7e6d JS |
188 | /* Populate sysfs for TPM1 devices. */ |
189 | if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) { | |
190 | rc = tpm_sysfs_add_device(chip); | |
191 | if (rc) | |
192 | goto del_misc; | |
afb5abc2 | 193 | |
7a1d7e6d JS |
194 | rc = tpm_add_ppi(chip); |
195 | if (rc) | |
196 | goto del_sysfs; | |
afb5abc2 | 197 | |
7a1d7e6d JS |
198 | chip->bios_dir = tpm_bios_log_setup(chip->devname); |
199 | } | |
afb5abc2 | 200 | |
19913b6d JS |
201 | rc = tpm_dev_add_device(chip); |
202 | if (rc) | |
203 | return rc; | |
204 | ||
afb5abc2 JS |
205 | /* Make the chip available. */ |
206 | spin_lock(&driver_lock); | |
207 | list_add_rcu(&chip->list, &tpm_chip_list); | |
208 | spin_unlock(&driver_lock); | |
209 | ||
210 | chip->flags |= TPM_CHIP_FLAG_REGISTERED; | |
211 | ||
212 | return 0; | |
213 | del_sysfs: | |
214 | tpm_sysfs_del_device(chip); | |
215 | del_misc: | |
216 | tpm_dev_del_device(chip); | |
217 | return rc; | |
218 | } | |
219 | EXPORT_SYMBOL_GPL(tpm_chip_register); | |
220 | ||
221 | /* | |
222 | * tpm_chip_unregister() - release the TPM driver | |
223 | * @chip: TPM chip to use. | |
224 | * | |
225 | * Takes the chip first away from the list of available TPM chips and then | |
226 | * cleans up all the resources reserved by tpm_chip_register(). | |
227 | * | |
228 | * NOTE: This function should be only called before deinitializing chip | |
229 | * resources. | |
230 | */ | |
231 | void tpm_chip_unregister(struct tpm_chip *chip) | |
232 | { | |
233 | if (!(chip->flags & TPM_CHIP_FLAG_REGISTERED)) | |
234 | return; | |
235 | ||
236 | spin_lock(&driver_lock); | |
237 | list_del_rcu(&chip->list); | |
238 | spin_unlock(&driver_lock); | |
239 | synchronize_rcu(); | |
240 | ||
7a1d7e6d JS |
241 | if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) { |
242 | if (chip->bios_dir) | |
243 | tpm_bios_log_teardown(chip->bios_dir); | |
244 | tpm_remove_ppi(chip); | |
245 | tpm_sysfs_del_device(chip); | |
246 | } | |
afb5abc2 JS |
247 | |
248 | tpm_dev_del_device(chip); | |
249 | } | |
250 | EXPORT_SYMBOL_GPL(tpm_chip_unregister); |