xref: /linux/arch/arm64/include/asm/rsi_cmds.h (revision bca5cfbb694d66a1c482d0c347eee80f6afbc870)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2023 ARM Ltd.
4  */
5 
6 #ifndef __ASM_RSI_CMDS_H
7 #define __ASM_RSI_CMDS_H
8 
9 #include <linux/arm-smccc.h>
10 #include <linux/string.h>
11 #include <asm/memory.h>
12 
13 #include <asm/rsi_smc.h>
14 
15 #define RSI_GRANULE_SHIFT		12
16 #define RSI_GRANULE_SIZE		(_AC(1, UL) << RSI_GRANULE_SHIFT)
17 
18 enum ripas {
19 	RSI_RIPAS_EMPTY = 0,
20 	RSI_RIPAS_RAM = 1,
21 	RSI_RIPAS_DESTROYED = 2,
22 	RSI_RIPAS_DEV = 3,
23 };
24 
25 static inline unsigned long rsi_request_version(unsigned long req,
26 						unsigned long *out_lower,
27 						unsigned long *out_higher)
28 {
29 	struct arm_smccc_res res;
30 
31 	arm_smccc_smc(SMC_RSI_ABI_VERSION, req, 0, 0, 0, 0, 0, 0, &res);
32 
33 	if (out_lower)
34 		*out_lower = res.a1;
35 	if (out_higher)
36 		*out_higher = res.a2;
37 
38 	return res.a0;
39 }
40 
41 static inline unsigned long rsi_get_realm_config(struct realm_config *cfg)
42 {
43 	struct arm_smccc_res res;
44 
45 	arm_smccc_smc(SMC_RSI_REALM_CONFIG, virt_to_phys(cfg),
46 		      0, 0, 0, 0, 0, 0, &res);
47 	return res.a0;
48 }
49 
50 static inline unsigned long rsi_ipa_state_get(phys_addr_t start,
51 					      phys_addr_t end,
52 					      enum ripas *state,
53 					      phys_addr_t *top)
54 {
55 	struct arm_smccc_res res;
56 
57 	arm_smccc_smc(SMC_RSI_IPA_STATE_GET,
58 		      start, end, 0, 0, 0, 0, 0,
59 		      &res);
60 
61 	if (res.a0 == RSI_SUCCESS) {
62 		if (top)
63 			*top = res.a1;
64 		if (state)
65 			*state = res.a2;
66 	}
67 
68 	return res.a0;
69 }
70 
71 static inline long rsi_set_addr_range_state(phys_addr_t start,
72 					    phys_addr_t end,
73 					    enum ripas state,
74 					    unsigned long flags,
75 					    phys_addr_t *top)
76 {
77 	struct arm_smccc_res res;
78 
79 	arm_smccc_smc(SMC_RSI_IPA_STATE_SET, start, end, state,
80 		      flags, 0, 0, 0, &res);
81 
82 	if (top)
83 		*top = res.a1;
84 
85 	if (res.a2 != RSI_ACCEPT)
86 		return -EPERM;
87 
88 	return res.a0;
89 }
90 
91 /**
92  * rsi_attestation_token_init - Initialise the operation to retrieve an
93  * attestation token.
94  *
95  * @challenge:	The challenge data to be used in the attestation token
96  *		generation.
97  * @size:	Size of the challenge data in bytes.
98  *
99  * Initialises the attestation token generation and returns an upper bound
100  * on the attestation token size that can be used to allocate an adequate
101  * buffer. The caller is expected to subsequently call
102  * rsi_attestation_token_continue() to retrieve the attestation token data on
103  * the same CPU.
104  *
105  * Returns:
106  *  On success, returns the upper limit of the attestation report size.
107  *  Otherwise, -EINVAL
108  */
109 static inline long
110 rsi_attestation_token_init(const u8 *challenge, unsigned long size)
111 {
112 	struct arm_smccc_1_2_regs regs = { 0 };
113 
114 	/* The challenge must be at least 32bytes and at most 64bytes */
115 	if (!challenge || size < 32 || size > 64)
116 		return -EINVAL;
117 
118 	regs.a0 = SMC_RSI_ATTESTATION_TOKEN_INIT;
119 	memcpy(&regs.a1, challenge, size);
120 	arm_smccc_1_2_smc(&regs, &regs);
121 
122 	if (regs.a0 == RSI_SUCCESS)
123 		return regs.a1;
124 
125 	return -EINVAL;
126 }
127 
128 /**
129  * rsi_attestation_token_continue - Continue the operation to retrieve an
130  * attestation token.
131  *
132  * @granule: {I}PA of the Granule to which the token will be written.
133  * @offset:  Offset within Granule to start of buffer in bytes.
134  * @size:    The size of the buffer.
135  * @len:     The number of bytes written to the buffer.
136  *
137  * Retrieves up to a RSI_GRANULE_SIZE worth of token data per call. The caller
138  * is expected to call rsi_attestation_token_init() before calling this
139  * function to retrieve the attestation token.
140  *
141  * Return:
142  * * %RSI_SUCCESS     - Attestation token retrieved successfully.
143  * * %RSI_INCOMPLETE  - Token generation is not complete.
144  * * %RSI_ERROR_INPUT - A parameter was not valid.
145  * * %RSI_ERROR_STATE - Attestation not in progress.
146  */
147 static inline unsigned long rsi_attestation_token_continue(phys_addr_t granule,
148 							   unsigned long offset,
149 							   unsigned long size,
150 							   unsigned long *len)
151 {
152 	struct arm_smccc_res res;
153 
154 	arm_smccc_1_1_invoke(SMC_RSI_ATTESTATION_TOKEN_CONTINUE,
155 			     granule, offset, size, 0, &res);
156 
157 	if (len)
158 		*len = res.a1;
159 	return res.a0;
160 }
161 
162 #endif /* __ASM_RSI_CMDS_H */
163