platform/generic-arm64/smc.c

/*
 * Copyright (c) 2015 Google Inc. All rights reserved
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include "smc.h"

#if ARCH_ARM64
#define SMC_ARG0 "x0"
#define SMC_ARG1 "x1"
#define SMC_ARG2 "x2"
#define SMC_ARG3 "x3"
#define SMC_ARCH_EXTENSION ""
#define SMC_REGISTERS_TRASHED                                              \
    "x4", "x5", "x6", "x7", "x8", "x9", "x10", "x11", "x12", "x13", "x14", \
            "x15", "x16", "x17"
#else
#define SMC_ARG0 "r0"
#define SMC_ARG1 "r1"
#define SMC_ARG2 "r2"
#define SMC_ARG3 "r3"
#define SMC_ARCH_EXTENSION ".arch_extension sec\n"
#define SMC_REGISTERS_TRASHED "ip"
#endif

ulong generic_arm64_smc(ulong r0, ulong r1, ulong r2, ulong r3) {
    register ulong _r0 __asm__(SMC_ARG0) = r0;
    register ulong _r1 __asm__(SMC_ARG1) = r1;
    register ulong _r2 __asm__(SMC_ARG2) = r2;
    register ulong _r3 __asm__(SMC_ARG3) = r3;

    __asm__ volatile(SMC_ARCH_EXTENSION "smc	#0" /* switch to secure world */
                     : "=r"(_r0), "=r"(_r1), "=r"(_r2), "=r"(_r3)
                     : "r"(_r0), "r"(_r1), "r"(_r2), "r"(_r3)
                     : SMC_REGISTERS_TRASHED);
    return _r0;
}