Skip to content

GitLab

Switch branch/tag
Find file Normal viewHistoryPermalink
smccc_helpers.h 4.74 KB
Newer Older
Antonio Nino Diaz's avatar
Rename 'smcc' to 'smccc'    
Antonio Nino Diaz committed
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 
/*
 * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#ifndef __SMCCC_HELPERS_H__
#define __SMCCC_HELPERS_H__

#include <smccc.h>

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

#ifndef __ASSEMBLY__
#include <cassert.h>
Antonio Nino Diaz's avatar
libc: Fix all includes in codebase    
Antonio Nino Diaz committed
29 
#include <stdint.h>
Antonio Nino Diaz's avatar
Rename 'smcc' to 'smccc'    
Antonio Nino Diaz committed
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 

/*
 * 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) & 0x7) == 0, 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));	\
}

/*
 * 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 /*__ASSEMBLY__*/

#endif /* __SMCCC_HELPERS_H__ */