/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Macro to call vDSO functions
 *
 * Copyright (C) 2024 Christophe Leroy <christophe.leroy@csgroup.eu>, CS GROUP France
 */
#ifndef __VDSO_CALL_H__
#define __VDSO_CALL_H__

#ifdef __powerpc__

#define LOADARGS_1(fn, __arg1) do {                                     \
        _r0 = fn;                                                       \
        _r3 = (long)__arg1;                                             \
} while (0)

#define LOADARGS_2(fn, __arg1, __arg2) do {                             \
        _r0 = fn;                                                       \
        _r3 = (long)__arg1;                                             \
        _r4 = (long)__arg2;                                             \
} while (0)

#define LOADARGS_3(fn, __arg1, __arg2, __arg3) do {                     \
        _r0 = fn;                                                       \
        _r3 = (long)__arg1;                                             \
        _r4 = (long)__arg2;                                             \
        _r5 = (long)__arg3;                                             \
} while (0)

#define LOADARGS_5(fn, __arg1, __arg2, __arg3, __arg4, __arg5) do {     \
        _r0 = fn;                                                       \
        _r3 = (long)__arg1;                                             \
        _r4 = (long)__arg2;                                             \
        _r5 = (long)__arg3;                                             \
        _r6 = (long)__arg4;                                             \
        _r7 = (long)__arg5;                                             \
} while (0)

#define VDSO_CALL(fn, nr, args...) ({                                   \
        register void *_r0 asm ("r0");                                  \
        register long _r3 asm ("r3");                                   \
        register long _r4 asm ("r4");                                   \
        register long _r5 asm ("r5");                                   \
        register long _r6 asm ("r6");                                   \
        register long _r7 asm ("r7");                                   \
        register long _r8 asm ("r8");                                   \
                                                                        \
        LOADARGS_##nr(fn, args);                                        \
                                                                        \
        asm volatile(                                                   \
                "       mtctr %0\n"                                     \
                "       bctrl\n"                                        \
                "       bns+    1f\n"                                   \
                "       neg     3, 3\n"                                 \
                "1:"                                                    \
                : "+r" (_r0), "+r" (_r3), "+r" (_r4), "+r" (_r5),       \
                  "+r" (_r6), "+r" (_r7), "+r" (_r8)                    \
                :                                                       \
                : "r9", "r10", "r11", "r12", "cr0", "cr1", "cr5",       \
                  "cr6", "cr7", "xer", "lr", "ctr", "memory"            \
        );                                                              \
        _r3;                                                            \
})

#else
#define VDSO_CALL(fn, nr, args...)      fn(args)
#endif

#endif