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Soby Mathewacc144b2016-05-05 12:53:53 +01001/*
Dimitris Papastamos0a4cded2018-01-02 11:37:02 +00002 * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
Soby Mathewacc144b2016-05-05 12:53:53 +01003 *
dp-armfa3cf0b2017-05-03 09:38:09 +01004 * SPDX-License-Identifier: BSD-3-Clause
Soby Mathewacc144b2016-05-05 12:53:53 +01005 */
6
7#ifndef __SMCC_HELPERS_H__
8#define __SMCC_HELPERS_H__
9
10#include <smcc.h>
11
12/* These are offsets to registers in smc_ctx_t */
13#define SMC_CTX_GPREG_R0 0x0
14#define SMC_CTX_GPREG_R1 0x4
15#define SMC_CTX_GPREG_R2 0x8
16#define SMC_CTX_GPREG_R3 0xC
17#define SMC_CTX_GPREG_R4 0x10
Soby Mathewadb70272016-12-06 12:10:51 +000018#define SMC_CTX_GPREG_R5 0x14
Soby Mathewacc144b2016-05-05 12:53:53 +010019#define SMC_CTX_SP_USR 0x34
20#define SMC_CTX_SPSR_MON 0x78
Soby Mathewf3e3a432017-03-30 14:42:54 +010021#define SMC_CTX_SP_MON 0x7C
22#define SMC_CTX_LR_MON 0x80
23#define SMC_CTX_SCR 0x84
David Cunado4168f2f2017-10-02 17:41:39 +010024#define SMC_CTX_PMCR 0x88
Dimitris Papastamos0a4cded2018-01-02 11:37:02 +000025#define SMC_CTX_SIZE 0x90
Soby Mathewacc144b2016-05-05 12:53:53 +010026
27#ifndef __ASSEMBLY__
28#include <cassert.h>
29#include <types.h>
30
31/*
32 * The generic structure to save arguments and callee saved registers during
33 * an SMC. Also this structure is used to store the result return values after
34 * the completion of SMC service.
35 */
36typedef struct smc_ctx {
37 u_register_t r0;
38 u_register_t r1;
39 u_register_t r2;
40 u_register_t r3;
41 u_register_t r4;
42 u_register_t r5;
43 u_register_t r6;
44 u_register_t r7;
45 u_register_t r8;
46 u_register_t r9;
47 u_register_t r10;
48 u_register_t r11;
49 u_register_t r12;
50 /* spsr_usr doesn't exist */
51 u_register_t sp_usr;
52 u_register_t lr_usr;
53 u_register_t spsr_irq;
54 u_register_t sp_irq;
55 u_register_t lr_irq;
56 u_register_t spsr_fiq;
57 u_register_t sp_fiq;
58 u_register_t lr_fiq;
59 u_register_t spsr_svc;
60 u_register_t sp_svc;
61 u_register_t lr_svc;
62 u_register_t spsr_abt;
63 u_register_t sp_abt;
64 u_register_t lr_abt;
65 u_register_t spsr_und;
66 u_register_t sp_und;
67 u_register_t lr_und;
68 u_register_t spsr_mon;
Soby Mathewf3e3a432017-03-30 14:42:54 +010069 /*
70 * `sp_mon` will point to the C runtime stack in monitor mode. But prior
71 * to exit from SMC, this will point to the `smc_ctx_t` so that
72 * on next entry due to SMC, the `smc_ctx_t` can be easily accessed.
73 */
74 u_register_t sp_mon;
Soby Mathewacc144b2016-05-05 12:53:53 +010075 u_register_t lr_mon;
Soby Mathewf3e3a432017-03-30 14:42:54 +010076 u_register_t scr;
David Cunado4168f2f2017-10-02 17:41:39 +010077 u_register_t pmcr;
Dimitris Papastamos0a4cded2018-01-02 11:37:02 +000078 /*
79 * The workaround for CVE-2017-5715 requires storing information in
80 * the bottom 3 bits of the stack pointer. Add a padding field to
81 * force the size of the struct to be a multiple of 8.
82 */
83 u_register_t pad;
84} smc_ctx_t __aligned(8);
Soby Mathewacc144b2016-05-05 12:53:53 +010085
86/*
87 * Compile time assertions related to the 'smc_context' structure to
88 * ensure that the assembler and the compiler view of the offsets of
89 * the structure members is the same.
90 */
91CASSERT(SMC_CTX_GPREG_R0 == __builtin_offsetof(smc_ctx_t, r0), \
92 assert_smc_ctx_greg_r0_offset_mismatch);
93CASSERT(SMC_CTX_GPREG_R1 == __builtin_offsetof(smc_ctx_t, r1), \
94 assert_smc_ctx_greg_r1_offset_mismatch);
95CASSERT(SMC_CTX_GPREG_R2 == __builtin_offsetof(smc_ctx_t, r2), \
96 assert_smc_ctx_greg_r2_offset_mismatch);
97CASSERT(SMC_CTX_GPREG_R3 == __builtin_offsetof(smc_ctx_t, r3), \
98 assert_smc_ctx_greg_r3_offset_mismatch);
99CASSERT(SMC_CTX_GPREG_R4 == __builtin_offsetof(smc_ctx_t, r4), \
100 assert_smc_ctx_greg_r4_offset_mismatch);
101CASSERT(SMC_CTX_SP_USR == __builtin_offsetof(smc_ctx_t, sp_usr), \
102 assert_smc_ctx_sp_usr_offset_mismatch);
103CASSERT(SMC_CTX_LR_MON == __builtin_offsetof(smc_ctx_t, lr_mon), \
104 assert_smc_ctx_lr_mon_offset_mismatch);
105CASSERT(SMC_CTX_SPSR_MON == __builtin_offsetof(smc_ctx_t, spsr_mon), \
106 assert_smc_ctx_spsr_mon_offset_mismatch);
107
Dimitris Papastamos0a4cded2018-01-02 11:37:02 +0000108CASSERT((sizeof(smc_ctx_t) & 0x7) == 0, assert_smc_ctx_not_aligned);
Soby Mathewacc144b2016-05-05 12:53:53 +0100109CASSERT(SMC_CTX_SIZE == sizeof(smc_ctx_t), assert_smc_ctx_size_mismatch);
110
111/* Convenience macros to return from SMC handler */
112#define SMC_RET0(_h) { \
113 return (uintptr_t)(_h); \
114}
115#define SMC_RET1(_h, _r0) { \
116 ((smc_ctx_t *)(_h))->r0 = (_r0); \
117 SMC_RET0(_h); \
118}
119#define SMC_RET2(_h, _r0, _r1) { \
120 ((smc_ctx_t *)(_h))->r1 = (_r1); \
121 SMC_RET1(_h, (_r0)); \
122}
123#define SMC_RET3(_h, _r0, _r1, _r2) { \
124 ((smc_ctx_t *)(_h))->r2 = (_r2); \
125 SMC_RET2(_h, (_r0), (_r1)); \
126}
127#define SMC_RET4(_h, _r0, _r1, _r2, _r3) { \
128 ((smc_ctx_t *)(_h))->r3 = (_r3); \
129 SMC_RET3(_h, (_r0), (_r1), (_r2)); \
130}
131
132/* Return a UUID in the SMC return registers */
133#define SMC_UUID_RET(_h, _uuid) \
134 SMC_RET4(handle, ((const uint32_t *) &(_uuid))[0], \
135 ((const uint32_t *) &(_uuid))[1], \
136 ((const uint32_t *) &(_uuid))[2], \
137 ((const uint32_t *) &(_uuid))[3])
138
139/*
140 * Helper macro to retrieve the SMC parameters from smc_ctx_t.
141 */
142#define get_smc_params_from_ctx(_hdl, _r1, _r2, _r3, _r4) { \
143 _r1 = ((smc_ctx_t *)_hdl)->r1; \
144 _r2 = ((smc_ctx_t *)_hdl)->r2; \
145 _r3 = ((smc_ctx_t *)_hdl)->r3; \
146 _r4 = ((smc_ctx_t *)_hdl)->r4; \
147 }
148
149/* ------------------------------------------------------------------------
150 * Helper APIs for setting and retrieving appropriate `smc_ctx_t`.
151 * These functions need to implemented by the BL including this library.
152 * ------------------------------------------------------------------------
153 */
154
155/* Get the pointer to `smc_ctx_t` corresponding to the security state. */
Etienne Carrierebfe12d32017-06-07 16:45:42 +0200156void *smc_get_ctx(unsigned int security_state);
Soby Mathewacc144b2016-05-05 12:53:53 +0100157
158/* Set the next `smc_ctx_t` corresponding to the security state. */
Etienne Carrierebfe12d32017-06-07 16:45:42 +0200159void smc_set_next_ctx(unsigned int security_state);
Soby Mathewacc144b2016-05-05 12:53:53 +0100160
161/* Get the pointer to next `smc_ctx_t` already set by `smc_set_next_ctx()`. */
162void *smc_get_next_ctx(void);
163
164#endif /*__ASSEMBLY__*/
165#endif /* __SMCC_HELPERS_H__ */