1/*
2 * Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29/* Helper macros for 64-bit mode switching */
30
31#if __i386__
32/*
33 * Long jump to 64-bit space from 32-bit compatibility mode.
34 */
35#define	ENTER_64BIT_MODE()			\
36	.code32					;\
37	.byte   0xea	/* far jump longmode */	;\
38	.long   1f				;\
39	.word   KERNEL64_CS			;\
40        .code64					;\
411:
42
43/*
44 * Here in long mode but still running below 4G.
45 * "Near" jump into uber-space.
46 */
47#define	ENTER_UBERSPACE()			\
48        mov     2f,%rax				;\
49        jmp     *%rax				;\
502:      .long   3f				;\
51        .long   KERNEL_UBER_BASE_HI32		;\
523:
53
54/*
55 * Long jump to 32-bit compatibility mode from 64-bit space.
56 */
57#define ENTER_COMPAT_MODE()			\
58	ljmp	*(%rip)				;\
59	.long	4f				;\
60	.word	KERNEL32_CS			;\
61	.code32					;\
624:
63
64#else
65
66/*
67 * Long jump to 64-bit space from 32-bit compatibility mode.
68 * Effected, in fact, by a long return ..
69 *  - we push the 64-bit kernel code selector KERNEL64_CS
70 *  - call .+1 to get EIP on stack
71 *  - adjust return address after lret
72 *  - lret to return to next instruction but 64-bit mode.
73 */
74#define	ENTER_64BIT_MODE()			\
75	push	$KERNEL64_CS			;\
76	call    1f				;\
771:	addl    $(2f-1b), (%esp)		;\
78	lret					;\
792:	.code64
80
81/*
82 * Long jump to 32-bit compatibility mode from 64-bit space.
83 * Effected by long return similar to ENTER_64BIT_MODE.
84 */
85#define ENTER_COMPAT_MODE()			\
86	call	3f				;\
873:	addq	$(4f-3b), (%rsp)		;\
88	movl	$KERNEL32_CS, 4(%rsp)		;\
89	lret					;\
904:	.code32
91
92#endif
93