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Christoffer Dall749cf76c2013-01-20 18:28:06 -05001/*
2 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
3 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2, as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
17 */
Christoffer Dall342cd0a2013-01-20 18:28:06 -050018
19#include <linux/linkage.h>
Christoffer Dall342cd0a2013-01-20 18:28:06 -050020
21 .text
Christoffer Dall342cd0a2013-01-20 18:28:06 -050022
23/********************************************************************
24 * Call function in Hyp mode
25 *
26 *
Marc Zyngierb57cd6f2016-01-06 12:10:58 +000027 * unsigned long kvm_call_hyp(void *hypfn, ...);
Christoffer Dall342cd0a2013-01-20 18:28:06 -050028 *
29 * This is not really a variadic function in the classic C-way and care must
30 * be taken when calling this to ensure parameters are passed in registers
31 * only, since the stack will change between the caller and the callee.
32 *
33 * Call the function with the first argument containing a pointer to the
34 * function you wish to call in Hyp mode, and subsequent arguments will be
35 * passed as r0, r1, and r2 (a maximum of 3 arguments in addition to the
36 * function pointer can be passed). The function being called must be mapped
37 * in Hyp mode (see init_hyp_mode in arch/arm/kvm/arm.c). Return values are
Marc Zyngierb57cd6f2016-01-06 12:10:58 +000038 * passed in r0 (strictly 32bit).
Christoffer Dall342cd0a2013-01-20 18:28:06 -050039 *
Marc Zyngierb20c9f22014-02-26 18:47:36 +000040 * A function pointer with a value of 0xffffffff has a special meaning,
41 * and is used to implement __hyp_get_vectors in the same way as in
42 * arch/arm/kernel/hyp_stub.S.
43 *
Christoffer Dall342cd0a2013-01-20 18:28:06 -050044 * The calling convention follows the standard AAPCS:
45 * r0 - r3: caller save
46 * r12: caller save
47 * rest: callee save
48 */
49ENTRY(kvm_call_hyp)
50 hvc #0
51 bx lr
Marc Zyngierb98e2e72016-01-05 18:45:17 +000052ENDPROC(kvm_call_hyp)