trusty-smc-arm.S
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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2020 Google, Inc.
*/
#include <linux/linkage.h>
.arch_extension sec
SYM_FUNC_START(trusty_smc8)
/* Save stack location where r3-r7 smc arguments are stored */
mov r12, sp
/* Save original r4-r7 values as caller expects these to be preserved */
push {r4-r7}
/* Save return value pointer and return address */
push {r0, lr}
/* arm abi shifts arguments when returning a struct, shift them back */
mov r0, r1
mov r1, r2
mov r2, r3
/* Load stack based arguments */
ldmia r12, {r3-r7}
smc #0
/* Restore return address and get return value pointer */
pop {r12, lr}
/* Copy 8-register smc return value to struct smc_ret8 return value */
stmia r12, {r0-r7}
/* Restore original r4-r7 values */
pop {r4-r7}
/* Return */
bx lr
SYM_FUNC_END(trusty_smc8)