linux-sg2042/arch/arm64/kvm/hyp.S

35 lines
1.1 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012,2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
#include <linux/linkage.h>
#include <asm/alternative.h>
#include <asm/assembler.h>
#include <asm/cpufeature.h>
/*
* u64 __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 x0, x1, and x2 (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 x0.
*
* A function pointer with a value less than 0xfff has a special meaning,
* and is used to implement hyp stubs in the same way as in
* arch/arm64/kernel/hyp_stub.S.
*/
ENTRY(__kvm_call_hyp)
hvc #0
ret
ENDPROC(__kvm_call_hyp)