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/*
* 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 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 __ASSEMBLY__
#include <cassert.h>
#include <stdint.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)); \
}
/*
* 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 */