/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
 */

#include <linux/linkage.h>

	.text

/********************************************************************
 *  Call function in Hyp mode
 *
 *
 * unsigned long kvm_call_hyp(void *hypfn, ...);
 *
 * This is not really a variadic function in the classic C-way and care must
 * be taken when calling this to ensure parameters are passed in registers
 * only, since the stack will change between the caller and the callee.
 *
 * Call the function with the first argument containing a pointer to the
 * function you wish to call in Hyp mode, and subsequent arguments will be
 * passed as r0, r1, and r2 (a maximum of 3 arguments in addition to the
 * function pointer can be passed).  The function being called must be mapped
 * in Hyp mode (see init_hyp_mode in arch/arm/kvm/arm.c).  Return values are
 * passed in r0 (strictly 32bit).
 *
 * The calling convention follows the standard AAPCS:
 *   r0 - r3: caller save
 *   r12:     caller save
 *   rest:    callee save
 */
ENTRY(__kvm_call_hyp)
	hvc	#0
	bx	lr
ENDPROC(__kvm_call_hyp)