summaryrefslogtreecommitdiffstats
path: root/include/arch/aarch32/smccc_helpers.h
blob: 2ce7874ef27d83d8972c65d6b84683b62e239c13 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/*
 * Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#ifndef SMCCC_HELPERS_H
#define SMCCC_HELPERS_H

#include <lib/smccc.h>

/* These are offsets to registers in smc_ctx_t */
#define SMC_CTX_GPREG_R0	U(0x0)
#define SMC_CTX_GPREG_R1	U(0x4)
#define SMC_CTX_GPREG_R2	U(0x8)
#define SMC_CTX_GPREG_R3	U(0xC)
#define SMC_CTX_GPREG_R4	U(0x10)
#define SMC_CTX_GPREG_R5	U(0x14)
#define SMC_CTX_SP_USR		U(0x34)
#define SMC_CTX_SPSR_MON	U(0x78)
#define SMC_CTX_SP_MON		U(0x7C)
#define SMC_CTX_LR_MON		U(0x80)
#define SMC_CTX_SCR		U(0x84)
#define SMC_CTX_PMCR		U(0x88)
#define SMC_CTX_SIZE		U(0x90)

#ifndef __ASSEMBLER__

#include <stdint.h>

#include <lib/cassert.h>

/*
 * The generic structure to save arguments and callee saved registers during
 * an SMC. Also this structure is used to store the result return values after
 * the completion of SMC service.
 */
typedef struct smc_ctx {
	u_register_t r0;
	u_register_t r1;
	u_register_t r2;
	u_register_t r3;
	u_register_t r4;
	u_register_t r5;
	u_register_t r6;
	u_register_t r7;
	u_register_t r8;
	u_register_t r9;
	u_register_t r10;
	u_register_t r11;
	u_register_t r12;
	/* spsr_usr doesn't exist */
	u_register_t sp_usr;
	u_register_t lr_usr;
	u_register_t spsr_irq;
	u_register_t sp_irq;
	u_register_t lr_irq;
	u_register_t spsr_fiq;
	u_register_t sp_fiq;
	u_register_t lr_fiq;
	u_register_t spsr_svc;
	u_register_t sp_svc;
	u_register_t lr_svc;
	u_register_t spsr_abt;
	u_register_t sp_abt;
	u_register_t lr_abt;
	u_register_t spsr_und;
	u_register_t sp_und;
	u_register_t lr_und;
	u_register_t spsr_mon;
	/*
	 * `sp_mon` will point to the C runtime stack in monitor mode. But prior
	 * to exit from SMC, this will point to the `smc_ctx_t` so that
	 * on next entry due to SMC, the `smc_ctx_t` can be easily accessed.
	 */
	u_register_t sp_mon;
	u_register_t lr_mon;
	u_register_t scr;
	u_register_t pmcr;
	/*
	 * The workaround for CVE-2017-5715 requires storing information in
	 * the bottom 3 bits of the stack pointer.  Add a padding field to
	 * force the size of the struct to be a multiple of 8.
	 */
	u_register_t pad;
} smc_ctx_t __aligned(8);

/*
 * Compile time assertions related to the 'smc_context' structure to
 * ensure that the assembler and the compiler view of the offsets of
 * the structure members is the same.
 */
CASSERT(SMC_CTX_GPREG_R0 == __builtin_offsetof(smc_ctx_t, r0), \
	assert_smc_ctx_greg_r0_offset_mismatch);
CASSERT(SMC_CTX_GPREG_R1 == __builtin_offsetof(smc_ctx_t, r1), \
	assert_smc_ctx_greg_r1_offset_mismatch);
CASSERT(SMC_CTX_GPREG_R2 == __builtin_offsetof(smc_ctx_t, r2), \
	assert_smc_ctx_greg_r2_offset_mismatch);
CASSERT(SMC_CTX_GPREG_R3 == __builtin_offsetof(smc_ctx_t, r3), \
	assert_smc_ctx_greg_r3_offset_mismatch);
CASSERT(SMC_CTX_GPREG_R4 == __builtin_offsetof(smc_ctx_t, r4), \
	assert_smc_ctx_greg_r4_offset_mismatch);
CASSERT(SMC_CTX_SP_USR == __builtin_offsetof(smc_ctx_t, sp_usr), \
	assert_smc_ctx_sp_usr_offset_mismatch);
CASSERT(SMC_CTX_LR_MON == __builtin_offsetof(smc_ctx_t, lr_mon), \
	assert_smc_ctx_lr_mon_offset_mismatch);
CASSERT(SMC_CTX_SPSR_MON == __builtin_offsetof(smc_ctx_t, spsr_mon), \
	assert_smc_ctx_spsr_mon_offset_mismatch);

CASSERT((sizeof(smc_ctx_t) & 0x7U) == 0U, assert_smc_ctx_not_aligned);
CASSERT(SMC_CTX_SIZE == sizeof(smc_ctx_t), assert_smc_ctx_size_mismatch);

/* Convenience macros to return from SMC handler */
#define SMC_RET0(_h) {				\
	return (uintptr_t)(_h);			\
}
#define SMC_RET1(_h, _r0) {			\
	((smc_ctx_t *)(_h))->r0 = (_r0);	\
	SMC_RET0(_h);				\
}
#define SMC_RET2(_h, _r0, _r1) {		\
	((smc_ctx_t *)(_h))->r1 = (_r1);	\
	SMC_RET1(_h, (_r0));			\
}
#define SMC_RET3(_h, _r0, _r1, _r2) {		\
	((smc_ctx_t *)(_h))->r2 = (_r2);	\
	SMC_RET2(_h, (_r0), (_r1));		\
}
#define SMC_RET4(_h, _r0, _r1, _r2, _r3) {	\
	((smc_ctx_t *)(_h))->r3 = (_r3);	\
	SMC_RET3(_h, (_r0), (_r1), (_r2));	\
}
#define SMC_RET5(_h, _r0, _r1, _r2, _r3, _r4) {	\
	((smc_ctx_t *)(_h))->r4 = (_r4);	\
	SMC_RET4(_h, (_r0), (_r1), (_r2), (_r3));	\
}
#define SMC_RET6(_h, _r0, _r1, _r2, _r3, _r4, _r5) {	\
	((smc_ctx_t *)(_h))->r5 = (_r5);	\
	SMC_RET5(_h, (_r0), (_r1), (_r2), (_r3), (_r4));	\
}
#define SMC_RET7(_h, _r0, _r1, _r2, _r3, _r4, _r5, _r6) {	\
	((smc_ctx_t *)(_h))->r6 = (_r6);	\
	SMC_RET6(_h, (_r0), (_r1), (_r2), (_r3), (_r4), (_r5));	\
}
#define SMC_RET8(_h, _r0, _r1, _r2, _r3, _r4, _r5, _r6, _r7) {	\
	((smc_ctx_t *)(_h))->r7 = (_r7);	\
	SMC_RET7(_h, (_r0), (_r1), (_r2), (_r3), (_r4), (_r5), (_r6));	\
}

/*
 * Helper macro to retrieve the SMC parameters from smc_ctx_t.
 */
#define get_smc_params_from_ctx(_hdl, _r1, _r2, _r3, _r4) {	\
		_r1 = ((smc_ctx_t *)_hdl)->r1;		\
		_r2 = ((smc_ctx_t *)_hdl)->r2;		\
		_r3 = ((smc_ctx_t *)_hdl)->r3;		\
		_r4 = ((smc_ctx_t *)_hdl)->r4;		\
		}

/* ------------------------------------------------------------------------
 * Helper APIs for setting and retrieving appropriate `smc_ctx_t`.
 * These functions need to implemented by the BL including this library.
 * ------------------------------------------------------------------------
 */

/* Get the pointer to `smc_ctx_t` corresponding to the security state. */
void *smc_get_ctx(unsigned int security_state);

/* Set the next `smc_ctx_t` corresponding to the security state. */
void smc_set_next_ctx(unsigned int security_state);

/* Get the pointer to next `smc_ctx_t` already set by `smc_set_next_ctx()`. */
void *smc_get_next_ctx(void);

#endif /*__ASSEMBLER__*/

#endif /* SMCCC_HELPERS_H */