1/*-
 2 * SPDX-License-Identifier: MIT-CMU
 3 *
 4 * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
 5 * All rights reserved.
 6 *
 7 * Author: Chris G. Demetriou
 8 * 
 9 * Permission to use, copy, modify and distribute this software and
10 * its documentation is hereby granted, provided that both the copyright
11 * notice and this permission notice appear in all copies of the
12 * software, derivative works or modified versions, and any portions
13 * thereof, and that both notices appear in supporting documentation.
14 * 
15 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 
16 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 
17 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
18 * 
19 * Carnegie Mellon requests users of this software to return to
20 *
21 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
22 *  School of Computer Science
23 *  Carnegie Mellon University
24 *  Pittsburgh PA 15213-3890
25 *
26 * any improvements or extensions that they make and grant Carnegie the
27 * rights to redistribute these changes.
28 *
29 *	from: NetBSD: profile.h,v 1.9 1997/04/06 08:47:37 cgd Exp
30 *	from: FreeBSD: src/sys/alpha/include/profile.h,v 1.4 1999/12/29
31 */
32
33#ifdef __arm__
34#include <arm/profile.h>
35#else /* !__arm__ */
36
37#ifndef _MACHINE_PROFILE_H_
38#define	_MACHINE_PROFILE_H_
39
40#define	FUNCTION_ALIGNMENT	32
41
42typedef u_long	fptrdiff_t;
43
44#ifndef _KERNEL
45
46#include <sys/cdefs.h>
47
48typedef __uintfptr_t    uintfptr_t;
49
50#define	_MCOUNT_DECL \
51static void _mcount(uintfptr_t frompc, uintfptr_t selfpc) __used; \
52static void _mcount
53
54/*
55 * Call into _mcount. On arm64 the .mcount is a function so callers will
56 * handle caller saved registers. As we don't directly touch any callee
57 * saved registers we can just load the two arguments and use a tail call
58 * into the MI _mcount function.
59 *
60 * When building with gcc frompc will be in x0, however this is not the
61 * case on clang. As such we need to load it from the stack. As long as
62 * the caller follows the ABI this will load the correct value.
63 */
64#define	MCOUNT __asm(					\
65"	.text					\n"	\
66"	.align	6				\n"	\
67"	.type	.mcount,#function		\n"	\
68"	.globl	.mcount				\n"	\
69"	.mcount:				\n"	\
70"	.cfi_startproc				\n"	\
71	/* Allow this to work with BTI, see BTI_C in asm.h */ \
72"	hint	#34				\n"	\
73	/* Load the caller return address as frompc */	\
74"	ldr	x0, [x29, #8]			\n"	\
75	/* Use our return address as selfpc */		\
76"	mov	x1, lr				\n"	\
77"	b	_mcount				\n"	\
78"	.cfi_endproc				\n"	\
79"	.size	.mcount, . - .mcount		\n"	\
80	);
81#if 0
82/*
83 * If clang passed frompc correctly we could implement it like this, however
84 * all clang versions we care about would need to be fixed before we could
85 * make this change.
86 */
87void
88mcount(uintfptr_t frompc)
89{
90	_mcount(frompc, __builtin_return_address(0));
91}
92#endif
93
94#endif /* !_KERNEL */
95
96#endif /* !_MACHINE_PROFILE_H_ */
97
98#endif /* !__arm__ */