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Antonio Nino Diaz3c817f42018-03-21 10:49:27 +00001/*
2 * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
Antonio Nino Diaz5eb88372018-11-08 10:20:19 +00007#ifndef SMCCC_HELPERS_H
8#define SMCCC_HELPERS_H
Antonio Nino Diaz3c817f42018-03-21 10:49:27 +00009
Antonio Nino Diaze0f90632018-12-14 00:18:21 +000010#include <lib/smccc.h>
Antonio Nino Diaz3c817f42018-03-21 10:49:27 +000011
12/* These are offsets to registers in smc_ctx_t */
Antonio Nino Diazf0b14cf2018-10-04 09:55:23 +010013#define SMC_CTX_GPREG_R0 U(0x0)
14#define SMC_CTX_GPREG_R1 U(0x4)
15#define SMC_CTX_GPREG_R2 U(0x8)
16#define SMC_CTX_GPREG_R3 U(0xC)
17#define SMC_CTX_GPREG_R4 U(0x10)
18#define SMC_CTX_GPREG_R5 U(0x14)
19#define SMC_CTX_SP_USR U(0x34)
20#define SMC_CTX_SPSR_MON U(0x78)
21#define SMC_CTX_SP_MON U(0x7C)
22#define SMC_CTX_LR_MON U(0x80)
23#define SMC_CTX_SCR U(0x84)
24#define SMC_CTX_PMCR U(0x88)
25#define SMC_CTX_SIZE U(0x90)
Antonio Nino Diaz3c817f42018-03-21 10:49:27 +000026
Julius Werner53456fc2019-07-09 13:49:11 -070027#ifndef __ASSEMBLER__
Antonio Nino Diaze0f90632018-12-14 00:18:21 +000028
Antonio Nino Diaz4b32e622018-08-16 16:52:57 +010029#include <stdint.h>
Antonio Nino Diaz3c817f42018-03-21 10:49:27 +000030
Antonio Nino Diaze0f90632018-12-14 00:18:21 +000031#include <lib/cassert.h>
32
Antonio Nino Diaz3c817f42018-03-21 10:49:27 +000033/*
34 * The generic structure to save arguments and callee saved registers during
35 * an SMC. Also this structure is used to store the result return values after
36 * the completion of SMC service.
37 */
38typedef struct smc_ctx {
39 u_register_t r0;
40 u_register_t r1;
41 u_register_t r2;
42 u_register_t r3;
43 u_register_t r4;
44 u_register_t r5;
45 u_register_t r6;
46 u_register_t r7;
47 u_register_t r8;
48 u_register_t r9;
49 u_register_t r10;
50 u_register_t r11;
51 u_register_t r12;
52 /* spsr_usr doesn't exist */
53 u_register_t sp_usr;
54 u_register_t lr_usr;
55 u_register_t spsr_irq;
56 u_register_t sp_irq;
57 u_register_t lr_irq;
58 u_register_t spsr_fiq;
59 u_register_t sp_fiq;
60 u_register_t lr_fiq;
61 u_register_t spsr_svc;
62 u_register_t sp_svc;
63 u_register_t lr_svc;
64 u_register_t spsr_abt;
65 u_register_t sp_abt;
66 u_register_t lr_abt;
67 u_register_t spsr_und;
68 u_register_t sp_und;
69 u_register_t lr_und;
70 u_register_t spsr_mon;
71 /*
72 * `sp_mon` will point to the C runtime stack in monitor mode. But prior
73 * to exit from SMC, this will point to the `smc_ctx_t` so that
74 * on next entry due to SMC, the `smc_ctx_t` can be easily accessed.
75 */
76 u_register_t sp_mon;
77 u_register_t lr_mon;
78 u_register_t scr;
79 u_register_t pmcr;
80 /*
81 * The workaround for CVE-2017-5715 requires storing information in
82 * the bottom 3 bits of the stack pointer. Add a padding field to
83 * force the size of the struct to be a multiple of 8.
84 */
85 u_register_t pad;
86} smc_ctx_t __aligned(8);
87
88/*
89 * Compile time assertions related to the 'smc_context' structure to
90 * ensure that the assembler and the compiler view of the offsets of
91 * the structure members is the same.
92 */
93CASSERT(SMC_CTX_GPREG_R0 == __builtin_offsetof(smc_ctx_t, r0), \
94 assert_smc_ctx_greg_r0_offset_mismatch);
95CASSERT(SMC_CTX_GPREG_R1 == __builtin_offsetof(smc_ctx_t, r1), \
96 assert_smc_ctx_greg_r1_offset_mismatch);
97CASSERT(SMC_CTX_GPREG_R2 == __builtin_offsetof(smc_ctx_t, r2), \
98 assert_smc_ctx_greg_r2_offset_mismatch);
99CASSERT(SMC_CTX_GPREG_R3 == __builtin_offsetof(smc_ctx_t, r3), \
100 assert_smc_ctx_greg_r3_offset_mismatch);
101CASSERT(SMC_CTX_GPREG_R4 == __builtin_offsetof(smc_ctx_t, r4), \
102 assert_smc_ctx_greg_r4_offset_mismatch);
103CASSERT(SMC_CTX_SP_USR == __builtin_offsetof(smc_ctx_t, sp_usr), \
104 assert_smc_ctx_sp_usr_offset_mismatch);
105CASSERT(SMC_CTX_LR_MON == __builtin_offsetof(smc_ctx_t, lr_mon), \
106 assert_smc_ctx_lr_mon_offset_mismatch);
107CASSERT(SMC_CTX_SPSR_MON == __builtin_offsetof(smc_ctx_t, spsr_mon), \
108 assert_smc_ctx_spsr_mon_offset_mismatch);
109
Antonio Nino Diazf0b14cf2018-10-04 09:55:23 +0100110CASSERT((sizeof(smc_ctx_t) & 0x7U) == 0U, assert_smc_ctx_not_aligned);
Antonio Nino Diaz3c817f42018-03-21 10:49:27 +0000111CASSERT(SMC_CTX_SIZE == sizeof(smc_ctx_t), assert_smc_ctx_size_mismatch);
112
113/* Convenience macros to return from SMC handler */
114#define SMC_RET0(_h) { \
115 return (uintptr_t)(_h); \
116}
117#define SMC_RET1(_h, _r0) { \
118 ((smc_ctx_t *)(_h))->r0 = (_r0); \
119 SMC_RET0(_h); \
120}
121#define SMC_RET2(_h, _r0, _r1) { \
122 ((smc_ctx_t *)(_h))->r1 = (_r1); \
123 SMC_RET1(_h, (_r0)); \
124}
125#define SMC_RET3(_h, _r0, _r1, _r2) { \
126 ((smc_ctx_t *)(_h))->r2 = (_r2); \
127 SMC_RET2(_h, (_r0), (_r1)); \
128}
129#define SMC_RET4(_h, _r0, _r1, _r2, _r3) { \
130 ((smc_ctx_t *)(_h))->r3 = (_r3); \
131 SMC_RET3(_h, (_r0), (_r1), (_r2)); \
132}
133
Antonio Nino Diaz3c817f42018-03-21 10:49:27 +0000134/*
135 * Helper macro to retrieve the SMC parameters from smc_ctx_t.
136 */
137#define get_smc_params_from_ctx(_hdl, _r1, _r2, _r3, _r4) { \
138 _r1 = ((smc_ctx_t *)_hdl)->r1; \
139 _r2 = ((smc_ctx_t *)_hdl)->r2; \
140 _r3 = ((smc_ctx_t *)_hdl)->r3; \
141 _r4 = ((smc_ctx_t *)_hdl)->r4; \
142 }
143
144/* ------------------------------------------------------------------------
145 * Helper APIs for setting and retrieving appropriate `smc_ctx_t`.
146 * These functions need to implemented by the BL including this library.
147 * ------------------------------------------------------------------------
148 */
149
150/* Get the pointer to `smc_ctx_t` corresponding to the security state. */
151void *smc_get_ctx(unsigned int security_state);
152
153/* Set the next `smc_ctx_t` corresponding to the security state. */
154void smc_set_next_ctx(unsigned int security_state);
155
156/* Get the pointer to next `smc_ctx_t` already set by `smc_set_next_ctx()`. */
157void *smc_get_next_ctx(void);
158
Julius Werner53456fc2019-07-09 13:49:11 -0700159#endif /*__ASSEMBLER__*/
Antonio Nino Diaz3c817f42018-03-21 10:49:27 +0000160
Antonio Nino Diaz5eb88372018-11-08 10:20:19 +0000161#endif /* SMCCC_HELPERS_H */