1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Common features for sandbox TPM1 and TPM2 implementations
4  *
5  * Copyright 2021 Google LLC
6  */
7 
8 #ifndef __TPM_SANDBOX_COMMON_H
9 #define __TPM_SANDBOX_COMMON_H
10 
11 /*
12  * These numbers derive from adding the sizes of command fields as shown in
13  * the TPM commands manual.
14  */
15 #define TPM_HDR_LEN	10
16 
17 /* These are the different non-volatile spaces that we emulate */
18 enum sandbox_nv_space {
19 	NV_SEQ_ENABLE_LOCKING,
20 	NV_SEQ_GLOBAL_LOCK,
21 	NV_SEQ_FIRMWARE,
22 	NV_SEQ_KERNEL,
23 	NV_SEQ_BACKUP,
24 	NV_SEQ_FWMP,
25 	NV_SEQ_REC_HASH,
26 
27 	NV_SEQ_COUNT,
28 };
29 
30 /* TPM NVRAM location indices */
31 #define FIRMWARE_NV_INDEX		0x1007
32 #define KERNEL_NV_INDEX			0x1008
33 #define BACKUP_NV_INDEX			0x1009
34 #define FWMP_NV_INDEX			0x100a
35 #define MRC_REC_HASH_NV_INDEX		0x100b
36 
37 /* Size of each non-volatile space */
38 #define NV_DATA_SIZE		0x28
39 
40 /**
41  * struct nvdata_state - state of a single non-volatile-data 'space'
42  *
43  * @present: true if present
44  * @length: length in bytes (max NV_DATA_SIZE)
45  * @data: contents of non-volatile space
46  */
47 struct nvdata_state {
48 	bool present;
49 	int length;
50 	u8 data[NV_DATA_SIZE];
51 };
52 
53 /**
54  * sb_tpm_index_to_seq() - convert an index into a space sequence number
55  *
56  * This converts the index as used by the vboot code into an internal sequence
57  * number used by the sandbox emulation.
58  *
59  * @index: Index to use (FIRMWARE_NV_INDEX, etc.)
60  * Return: associated space (enum sandbox_nv_space)
61  */
62 int sb_tpm_index_to_seq(uint index);
63 
64 /**
65  * sb_tpm_read_data() - Read non-volatile data
66  *
67  * This handles a TPM read of nvdata. If the nvdata is not present, a
68  * TPM_BADINDEX error is put in the buffer. If @length is too large,
69  * TPM_BAD_DATASIZE is put in the buffer.
70  *
71  * @nvdata: Current nvdata state
72  * @seq: Sequence number to read
73  * @recvbuf: Buffer to update with the TPM response, assumed to contain zeroes
74  * @data_ofs: Offset of the 'data' portion of @recvbuf
75  * @length: Number of bytes to read
76  */
77 void sb_tpm_read_data(const struct nvdata_state nvdata[NV_SEQ_COUNT],
78 		      enum sandbox_nv_space seq, u8 *recvbuf, int data_ofs,
79 		      int length);
80 
81 /**
82  * sb_tpm_write_data() - Write non-volatile data
83  *
84  * If @length is too large, an error is logged and nothing is written.
85  *
86  * @nvdata: Current nvdata state
87  * @seq: Sequence number to read
88  * @buf: Buffer containing the data to write
89  * @data_ofs: Offset of the 'data' portion of @buf
90  * @length: Number of bytes to write
91  */
92 void sb_tpm_write_data(struct nvdata_state nvdata[NV_SEQ_COUNT],
93 		       enum sandbox_nv_space seq, const u8 *buf, int data_ofs,
94 		       int length);
95 
96 /**
97  * sb_tpm_define_data() - Set up non-volatile data
98  *
99  * If @length is too large, an error is logged and nothing is written.
100  *
101  * @nvdata: Current nvdata state
102  * @seq: Sequence number to set up
103  * @length: Length of space in bytes
104  */
105 void sb_tpm_define_data(struct nvdata_state nvdata[NV_SEQ_COUNT],
106 			enum sandbox_nv_space seq, int length);
107 
108 #endif
109