Commit | Line | Data |
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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 | ||
8cfffc9d | 52 | if (try_module_get(pos->dev.parent->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; | |
4f3b193d | 91 | int rc; |
afb5abc2 JS |
92 | |
93 | chip = kzalloc(sizeof(*chip), GFP_KERNEL); | |
94 | if (chip == NULL) | |
95 | return ERR_PTR(-ENOMEM); | |
96 | ||
97 | mutex_init(&chip->tpm_mutex); | |
98 | INIT_LIST_HEAD(&chip->list); | |
99 | ||
100 | chip->ops = ops; | |
101 | ||
102 | spin_lock(&driver_lock); | |
103 | chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES); | |
104 | spin_unlock(&driver_lock); | |
105 | ||
106 | if (chip->dev_num >= TPM_NUM_DEVICES) { | |
107 | dev_err(dev, "No available tpm device numbers\n"); | |
108 | kfree(chip); | |
109 | return ERR_PTR(-ENOMEM); | |
110 | } | |
111 | ||
112 | set_bit(chip->dev_num, dev_mask); | |
113 | ||
114 | scnprintf(chip->devname, sizeof(chip->devname), "tpm%d", chip->dev_num); | |
115 | ||
afb5abc2 JS |
116 | dev_set_drvdata(dev, chip); |
117 | ||
313d21ee JS |
118 | chip->dev.class = tpm_class; |
119 | chip->dev.release = tpm_dev_release; | |
8cfffc9d | 120 | chip->dev.parent = dev; |
9b774d5c JS |
121 | #ifdef CONFIG_ACPI |
122 | chip->dev.groups = chip->groups; | |
123 | #endif | |
313d21ee JS |
124 | |
125 | if (chip->dev_num == 0) | |
126 | chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR); | |
127 | else | |
128 | chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num); | |
129 | ||
743410a0 | 130 | dev_set_name(&chip->dev, "%s", chip->devname); |
313d21ee JS |
131 | |
132 | device_initialize(&chip->dev); | |
133 | ||
313d21ee | 134 | cdev_init(&chip->cdev, &tpm_fops); |
8cfffc9d | 135 | chip->cdev.owner = dev->driver->owner; |
ba0ef854 | 136 | chip->cdev.kobj.parent = &chip->dev.kobj; |
313d21ee | 137 | |
4f3b193d JS |
138 | rc = devm_add_action(dev, (void (*)(void *)) put_device, &chip->dev); |
139 | if (rc) { | |
140 | put_device(&chip->dev); | |
141 | return ERR_PTR(rc); | |
142 | } | |
8e0ee3c9 | 143 | |
afb5abc2 JS |
144 | return chip; |
145 | } | |
146 | EXPORT_SYMBOL_GPL(tpmm_chip_alloc); | |
147 | ||
72c91ce8 | 148 | static int tpm_add_char_device(struct tpm_chip *chip) |
313d21ee JS |
149 | { |
150 | int rc; | |
151 | ||
d972b052 | 152 | rc = cdev_add(&chip->cdev, chip->dev.devt, 1); |
313d21ee JS |
153 | if (rc) { |
154 | dev_err(&chip->dev, | |
d972b052 | 155 | "unable to cdev_add() %s, major %d, minor %d, err=%d\n", |
313d21ee JS |
156 | chip->devname, MAJOR(chip->dev.devt), |
157 | MINOR(chip->dev.devt), rc); | |
158 | ||
159 | return rc; | |
160 | } | |
161 | ||
d972b052 | 162 | rc = device_add(&chip->dev); |
313d21ee JS |
163 | if (rc) { |
164 | dev_err(&chip->dev, | |
d972b052 | 165 | "unable to device_register() %s, major %d, minor %d, err=%d\n", |
313d21ee JS |
166 | chip->devname, MAJOR(chip->dev.devt), |
167 | MINOR(chip->dev.devt), rc); | |
168 | ||
72c91ce8 | 169 | cdev_del(&chip->cdev); |
313d21ee JS |
170 | return rc; |
171 | } | |
172 | ||
173 | return rc; | |
174 | } | |
175 | ||
72c91ce8 | 176 | static void tpm_del_char_device(struct tpm_chip *chip) |
313d21ee JS |
177 | { |
178 | cdev_del(&chip->cdev); | |
8e0ee3c9 | 179 | device_del(&chip->dev); |
313d21ee JS |
180 | } |
181 | ||
34d47b63 JS |
182 | static int tpm1_chip_register(struct tpm_chip *chip) |
183 | { | |
184 | int rc; | |
185 | ||
186 | if (chip->flags & TPM_CHIP_FLAG_TPM2) | |
187 | return 0; | |
188 | ||
189 | rc = tpm_sysfs_add_device(chip); | |
190 | if (rc) | |
191 | return rc; | |
192 | ||
34d47b63 JS |
193 | chip->bios_dir = tpm_bios_log_setup(chip->devname); |
194 | ||
195 | return 0; | |
196 | } | |
197 | ||
198 | static void tpm1_chip_unregister(struct tpm_chip *chip) | |
199 | { | |
200 | if (chip->flags & TPM_CHIP_FLAG_TPM2) | |
201 | return; | |
202 | ||
203 | if (chip->bios_dir) | |
204 | tpm_bios_log_teardown(chip->bios_dir); | |
205 | ||
34d47b63 JS |
206 | tpm_sysfs_del_device(chip); |
207 | } | |
208 | ||
afb5abc2 | 209 | /* |
313d21ee | 210 | * tpm_chip_register() - create a character device for the TPM chip |
afb5abc2 JS |
211 | * @chip: TPM chip to use. |
212 | * | |
d972b052 JS |
213 | * Creates a character device for the TPM chip and adds sysfs attributes for |
214 | * the device. As the last step this function adds the chip to the list of TPM | |
215 | * chips available for in-kernel use. | |
afb5abc2 | 216 | * |
d972b052 JS |
217 | * This function should be only called after the chip initialization is |
218 | * complete. | |
afb5abc2 JS |
219 | */ |
220 | int tpm_chip_register(struct tpm_chip *chip) | |
221 | { | |
222 | int rc; | |
223 | ||
34d47b63 JS |
224 | rc = tpm1_chip_register(chip); |
225 | if (rc) | |
226 | return rc; | |
afb5abc2 | 227 | |
9b774d5c JS |
228 | tpm_add_ppi(chip); |
229 | ||
72c91ce8 | 230 | rc = tpm_add_char_device(chip); |
d972b052 | 231 | if (rc) |
34d47b63 | 232 | goto out_err; |
d972b052 | 233 | |
afb5abc2 JS |
234 | /* Make the chip available. */ |
235 | spin_lock(&driver_lock); | |
b1a4144a | 236 | list_add_tail_rcu(&chip->list, &tpm_chip_list); |
afb5abc2 JS |
237 | spin_unlock(&driver_lock); |
238 | ||
239 | chip->flags |= TPM_CHIP_FLAG_REGISTERED; | |
240 | ||
d56e4f75 | 241 | if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) { |
8cfffc9d JG |
242 | rc = __compat_only_sysfs_link_entry_to_kobj( |
243 | &chip->dev.parent->kobj, &chip->dev.kobj, "ppi"); | |
d56e4f75 JS |
244 | if (rc && rc != -ENOENT) { |
245 | tpm_chip_unregister(chip); | |
246 | return rc; | |
247 | } | |
248 | } | |
249 | ||
afb5abc2 | 250 | return 0; |
34d47b63 JS |
251 | out_err: |
252 | tpm1_chip_unregister(chip); | |
afb5abc2 JS |
253 | return rc; |
254 | } | |
255 | EXPORT_SYMBOL_GPL(tpm_chip_register); | |
256 | ||
257 | /* | |
258 | * tpm_chip_unregister() - release the TPM driver | |
259 | * @chip: TPM chip to use. | |
260 | * | |
261 | * Takes the chip first away from the list of available TPM chips and then | |
262 | * cleans up all the resources reserved by tpm_chip_register(). | |
263 | * | |
264 | * NOTE: This function should be only called before deinitializing chip | |
265 | * resources. | |
266 | */ | |
267 | void tpm_chip_unregister(struct tpm_chip *chip) | |
268 | { | |
269 | if (!(chip->flags & TPM_CHIP_FLAG_REGISTERED)) | |
270 | return; | |
271 | ||
272 | spin_lock(&driver_lock); | |
273 | list_del_rcu(&chip->list); | |
274 | spin_unlock(&driver_lock); | |
275 | synchronize_rcu(); | |
276 | ||
9b774d5c | 277 | if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) |
8cfffc9d | 278 | sysfs_remove_link(&chip->dev.parent->kobj, "ppi"); |
9b774d5c | 279 | |
34d47b63 | 280 | tpm1_chip_unregister(chip); |
72c91ce8 | 281 | tpm_del_char_device(chip); |
afb5abc2 JS |
282 | } |
283 | EXPORT_SYMBOL_GPL(tpm_chip_unregister); |