1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3 * Copyright (c) 2013 The Chromium OS Authors.
4 * Coypright (c) 2013 Guntermann & Drunck GmbH
5 */
6
7 #ifndef __TPM_COMMON_H
8 #define __TPM_COMMON_H
9
10 #include <command.h>
11
12 struct udevice;
13
14 enum tpm_duration {
15 TPM_SHORT = 0,
16 TPM_MEDIUM = 1,
17 TPM_LONG = 2,
18 TPM_UNDEFINED,
19
20 TPM_DURATION_COUNT,
21 };
22
23 /*
24 * Here is a partial implementation of TPM commands. Please consult TCG Main
25 * Specification for definitions of TPM commands.
26 */
27
28 #define TPM_HEADER_SIZE 10
29
30 /* Max buffer size supported by our tpm */
31 #define TPM_DEV_BUFSIZE 1260
32
33 #define TPM_PCR_MINIMUM_DIGEST_SIZE 20
34
35 /**
36 * enum tpm_version - The version of the TPM stack to be used
37 * @TPM_V1: Use TPM v1.x stack
38 * @TPM_V2: Use TPM v2.x stack
39 */
40 enum tpm_version {
41 TPM_V1 = 0,
42 TPM_V2,
43 };
44
45 /**
46 * struct tpm_chip_priv - Information about a TPM, stored by the uclass
47 *
48 * These values must be set up by the device's probe() method before
49 * communcation is attempted. If the device has an xfer() method, this is
50 * not needed. There is no need to set up @buf.
51 *
52 * @version: TPM stack to be used
53 * @duration_ms: Length of each duration type in milliseconds
54 * @retry_time_ms: Time to wait before retrying receive
55 * @buf: Buffer used during the exchanges with the chip
56 * @pcr_count: Number of PCR per bank
57 * @pcr_select_min: Minimum size in bytes of the pcrSelect array
58 * @plat_hier_disabled: Platform hierarchy has been disabled (TPM is locked
59 * down until next reboot)
60 */
61 struct tpm_chip_priv {
62 enum tpm_version version;
63
64 uint duration_ms[TPM_DURATION_COUNT];
65 uint retry_time_ms;
66 u8 buf[TPM_DEV_BUFSIZE + sizeof(u8)]; /* Max buffer size + addr */
67
68 /* TPM v2 specific data */
69 uint pcr_count;
70 uint pcr_select_min;
71 bool plat_hier_disabled;
72 };
73
74 /**
75 * struct tpm_ops - low-level TPM operations
76 *
77 * These are designed to avoid loops and delays in the driver itself. These
78 * should be handled in the uclass.
79 *
80 * In gneral you should implement everything except xfer(). Where you need
81 * complete control of the transfer, then xfer() can be provided and will
82 * override the other methods.
83 *
84 * This interface is for low-level TPM access. It does not understand the
85 * concept of localities or the various TPM messages. That interface is
86 * defined in the functions later on in this file, but they all translate
87 * to bytes which are sent and received.
88 */
89 struct tpm_ops {
90 /**
91 * open() - Request access to locality 0 for the caller
92 *
93 * After all commands have been completed the caller should call
94 * close().
95 *
96 * @dev: Device to open
97 * @return 0 ok OK, -ve on error
98 */
99 int (*open)(struct udevice *dev);
100
101 /**
102 * close() - Close the current session
103 *
104 * Releasing the locked locality. Returns 0 on success, -ve 1 on
105 * failure (in case lock removal did not succeed).
106 *
107 * @dev: Device to close
108 * @return 0 ok OK, -ve on error
109 */
110 int (*close)(struct udevice *dev);
111
112 /**
113 * get_desc() - Get a text description of the TPM
114 *
115 * @dev: Device to check
116 * @buf: Buffer to put the string
117 * @size: Maximum size of buffer
118 * @return length of string, or -ENOSPC it no space
119 */
120 int (*get_desc)(struct udevice *dev, char *buf, int size);
121
122 /**
123 * report_state() - Collect information about the current TPM state
124 *
125 * @dev: Device to check
126 * @buf: Buffer to put the string
127 * @size: Maximum size of buffer
128 * Return: return code of the operation (0 = success)
129 */
130 int (*report_state)(struct udevice *dev, char *buf, int size);
131
132 /**
133 * send() - send data to the TPM
134 *
135 * @dev: Device to talk to
136 * @sendbuf: Buffer of the data to send
137 * @send_size: Size of the data to send
138 *
139 * Returns 0 on success or -ve on failure.
140 */
141 int (*send)(struct udevice *dev, const u8 *sendbuf, size_t send_size);
142
143 /**
144 * recv() - receive a response from the TPM
145 *
146 * @dev: Device to talk to
147 * @recvbuf: Buffer to save the response to
148 * @max_size: Maximum number of bytes to receive
149 *
150 * Returns number of bytes received on success, -EAGAIN if the TPM
151 * response is not ready, -EINTR if cancelled, or other -ve value on
152 * failure.
153 */
154 int (*recv)(struct udevice *dev, u8 *recvbuf, size_t max_size);
155
156 /**
157 * cleanup() - clean up after an operation in progress
158 *
159 * This is called if receiving times out. The TPM may need to abort
160 * the current transaction if it did not complete, and make itself
161 * ready for another.
162 *
163 * @dev: Device to talk to
164 */
165 int (*cleanup)(struct udevice *dev);
166
167 /**
168 * xfer() - send data to the TPM and get response
169 *
170 * This method is optional. If it exists it is used in preference
171 * to send(), recv() and cleanup(). It should handle all aspects of
172 * TPM communication for a single transfer.
173 *
174 * @dev: Device to talk to
175 * @sendbuf: Buffer of the data to send
176 * @send_size: Size of the data to send
177 * @recvbuf: Buffer to save the response to
178 * @recv_size: Pointer to the size of the response buffer
179 *
180 * Returns 0 on success (and places the number of response bytes at
181 * recv_size) or -ve on failure.
182 */
183 int (*xfer)(struct udevice *dev, const u8 *sendbuf, size_t send_size,
184 u8 *recvbuf, size_t *recv_size);
185 };
186
187 #define tpm_get_ops(dev) ((struct tpm_ops *)device_get_ops(dev))
188
189 #define MAKE_TPM_CMD_ENTRY(cmd) \
190 U_BOOT_CMD_MKENT(cmd, 0, 1, do_tpm_ ## cmd, "", "")
191
192 #define TPM_COMMAND_NO_ARG(cmd) \
193 int do_##cmd(cmd_tbl_t *cmdtp, int flag, \
194 int argc, char *const argv[]) \
195 { \
196 struct udevice *dev; \
197 int rc; \
198 \
199 rc = get_tpm(&dev); \
200 if (rc) \
201 return rc; \
202 if (argc != 1) \
203 return CMD_RET_USAGE; \
204 return report_return_code(cmd(dev)); \
205 }
206
207 /**
208 * tpm_open() - Request access to locality 0 for the caller
209 *
210 * After all commands have been completed the caller is supposed to
211 * call tpm_close().
212 *
213 * @dev - TPM device
214 * Returns 0 on success, -ve on failure.
215 */
216 int tpm_open(struct udevice *dev);
217
218 /**
219 * tpm_close() - Close the current session
220 *
221 * Releasing the locked locality. Returns 0 on success, -ve 1 on
222 * failure (in case lock removal did not succeed).
223 *
224 * @dev - TPM device
225 * Returns 0 on success, -ve on failure.
226 */
227 int tpm_close(struct udevice *dev);
228
229 /**
230 * tpm_clear_and_reenable() - Force clear the TPM and reenable it
231 *
232 * @dev: TPM device
233 * Return: 0 on success, -ve on failure
234 */
235 u32 tpm_clear_and_reenable(struct udevice *dev);
236
237 /**
238 * tpm_get_desc() - Get a text description of the TPM
239 *
240 * @dev: Device to check
241 * @buf: Buffer to put the string
242 * @size: Maximum size of buffer
243 * Return: length of string, or -ENOSPC it no space
244 */
245 int tpm_get_desc(struct udevice *dev, char *buf, int size);
246
247 /**
248 * tpm_report_state() - Collect information about the current TPM state
249 *
250 * @dev: Device to check
251 * @buf: Buffer to put the string
252 * @size: Maximum size of buffer
253 * Return: return code of the operation (0 = success)
254 */
255 int tpm_report_state(struct udevice *dev, char *buf, int size);
256
257 /**
258 * tpm_xfer() - send data to the TPM and get response
259 *
260 * This first uses the device's send() method to send the bytes. Then it calls
261 * recv() to get the reply. If recv() returns -EAGAIN then it will delay a
262 * short time and then call recv() again.
263 *
264 * Regardless of whether recv() completes successfully, it will then call
265 * cleanup() to finish the transaction.
266 *
267 * Note that the outgoing data is inspected to determine command type
268 * (ordinal) and a timeout is used for that command type.
269 *
270 * @dev - TPM device
271 * @sendbuf - buffer of the data to send
272 * @send_size size of the data to send
273 * @recvbuf - memory to save the response to
274 * @recv_len - pointer to the size of the response buffer
275 *
276 * Returns 0 on success (and places the number of response bytes at
277 * recv_len) or -ve on failure.
278 */
279 int tpm_xfer(struct udevice *dev, const u8 *sendbuf, size_t send_size,
280 u8 *recvbuf, size_t *recv_size);
281
282 /**
283 * Initialize TPM device. It must be called before any TPM commands.
284 *
285 * @dev - TPM device
286 * Return: 0 on success, non-0 on error.
287 */
288 int tpm_init(struct udevice *dev);
289
290 /**
291 * Retrieve the array containing all the v1 (resp. v2) commands.
292 *
293 * Return: a cmd_tbl_t array.
294 */
295 #if defined(CONFIG_TPM_V1)
296 cmd_tbl_t *get_tpm1_commands(unsigned int *size);
297 #else
get_tpm1_commands(unsigned int * size)298 static inline cmd_tbl_t *get_tpm1_commands(unsigned int *size)
299 {
300 return NULL;
301 }
302 #endif
303 #if defined(CONFIG_TPM_V2)
304 cmd_tbl_t *get_tpm2_commands(unsigned int *size);
305 #else
get_tpm2_commands(unsigned int * size)306 static inline cmd_tbl_t *get_tpm2_commands(unsigned int *size)
307 {
308 return NULL;
309 }
310 #endif
311
312 /**
313 * tpm_get_version() - Find the version of a TPM
314 *
315 * This checks the uclass data for a TPM device and returns the version number
316 * it supports.
317 *
318 * @dev: TPM device
319 * Return: version number (TPM_V1 or TPMV2)
320 */
321 enum tpm_version tpm_get_version(struct udevice *dev);
322
323 /* Iterate on all TPM devices */
324 #define for_each_tpm_device(dev) uclass_foreach_dev_probe(UCLASS_TPM, (dev))
325
326 #endif /* __TPM_COMMON_H */
327