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/* $NetBSD: cdefs_elf.h,v 1.58 2021/06/04 01:58:02 thorpej Exp $ */
/*
* Copyright (c) 1995, 1996 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Chris G. Demetriou
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
#ifndef _SYS_CDEFS_ELF_H_
#define _SYS_CDEFS_ELF_H_
#ifdef __LEADING_UNDERSCORE
#define _C_LABEL(x) __CONCAT(_,x)
#define _C_LABEL_STRING(x) "_"x
#else
#define _C_LABEL(x) x
#define _C_LABEL_STRING(x) x
#endif
#if __STDC__
#define ___RENAME(x) __asm(___STRING(_C_LABEL(x)))
#else
#ifdef __LEADING_UNDERSCORE
#define ___RENAME(x) ____RENAME(_/**/x)
#define ____RENAME(x) __asm(___STRING(x))
#else
#define ___RENAME(x) __asm(___STRING(x))
#endif
#endif
#define __indr_reference(sym,alias) /* nada, since we do weak refs */
#if __STDC__
#define __strong_alias(alias,sym) \
__asm(".global " _C_LABEL_STRING(#alias) "\n" \
_C_LABEL_STRING(#alias) " = " _C_LABEL_STRING(#sym));
#define __weak_alias(alias,sym) \
__asm(".weak " _C_LABEL_STRING(#alias) "\n" \
_C_LABEL_STRING(#alias) " = " _C_LABEL_STRING(#sym));
/* Do not use __weak_extern, use __weak_reference instead */
#define __weak_extern(sym) \
__asm(".weak " _C_LABEL_STRING(#sym));
#if __GNUC_PREREQ__(4, 0)
#define __weak __attribute__((__weak__))
#else
#define __weak
#endif
#if __GNUC_PREREQ__(4, 0)
#define __weak_reference(sym) __attribute__((__weakref__(#sym)))
#else
#define __weak_reference(sym) ; __asm(".weak " _C_LABEL_STRING(#sym))
#endif
#if __GNUC_PREREQ__(4, 2)
#define __weakref_visible static
#else
#define __weakref_visible extern
#endif
#define __warn_references(sym,msg) \
__asm(".pushsection .gnu.warning." #sym "\n" \
".ascii \"" msg "\"\n" \
".popsection");
#else /* !__STDC__ */
#ifdef __LEADING_UNDERSCORE
#define __weak_alias(alias,sym) ___weak_alias(_/**/alias,_/**/sym)
#define ___weak_alias(alias,sym) \
__asm(".weak alias\nalias = sym");
#else
#define __weak_alias(alias,sym) \
__asm(".weak alias\nalias = sym");
#endif
#ifdef __LEADING_UNDERSCORE
#define __weak_extern(sym) ___weak_extern(_/**/sym)
#define ___weak_extern(sym) \
__asm(".weak sym");
#else
#define __weak_extern(sym) \
__asm(".weak sym");
#endif
#define __warn_references(sym,msg) \
__asm(".pushsection .gnu.warning.sym\n" \
".ascii \"" msg "\"\n" \
".popsection");
#endif /* !__STDC__ */
#if __arm__
#define __ifunc(name, resolver) \
__asm(".globl " _C_LABEL_STRING(#name) "\n" \
".type " _C_LABEL_STRING(#name) ", %gnu_indirect_function\n" \
_C_LABEL_STRING(#name) " = " _C_LABEL_STRING(#resolver))
#define __hidden_ifunc(name, resolver) \
__asm(".globl " _C_LABEL_STRING(#name) "\n" \
".hidden " _C_LABEL_STRING(#name) "\n" \
".type " _C_LABEL_STRING(#name) ", %gnu_indirect_function\n" \
_C_LABEL_STRING(#name) " = " _C_LABEL_STRING(#resolver))
#else
#define __ifunc(name, resolver) \
__asm(".globl " _C_LABEL_STRING(#name) "\n" \
".type " _C_LABEL_STRING(#name) ", @gnu_indirect_function\n" \
_C_LABEL_STRING(#name) " = " _C_LABEL_STRING(#resolver))
#define __hidden_ifunc(name, resolver) \
__asm(".globl " _C_LABEL_STRING(#name) "\n" \
".hidden " _C_LABEL_STRING(#name) "\n" \
".type " _C_LABEL_STRING(#name) ", @gnu_indirect_function\n" \
_C_LABEL_STRING(#name) " = " _C_LABEL_STRING(#resolver))
#endif
#ifdef __arm__
#if __STDC__
# define __SECTIONSTRING(_sec, _str) \
__asm(".pushsection " #_sec ",\"MS\",%progbits,1\n" \
".asciz \"" _str "\"\n" \
".popsection")
#else
# define __SECTIONSTRING(_sec, _str) \
__asm(".pushsection " _sec ",\"MS\",%progbits,1\n" \
".asciz \"" _str "\"\n" \
".popsection")
# endif
#else
# if __STDC__
# define __SECTIONSTRING(_sec, _str) \
__asm(".pushsection " #_sec ",\"MS\",@progbits,1\n" \
".asciz \"" _str "\"\n" \
".popsection")
# else
# define __SECTIONSTRING(_sec, _str) \
__asm(".pushsection " _sec ",\"MS\",@progbits,1\n" \
".asciz \"" _str "\"\n" \
".popsection")
# endif
#endif
#define __IDSTRING(_n,_s) __SECTIONSTRING(.ident,_s)
#define __RCSID(_s) __IDSTRING(rcsid,_s)
#define __SCCSID(_s)
#define __SCCSID2(_s)
#define __COPYRIGHT(_s) __SECTIONSTRING(.copyright,_s)
#define __KERNEL_RCSID(_n, _s) __RCSID(_s)
#define __KERNEL_SCCSID(_n, _s)
#define __KERNEL_COPYRIGHT(_n, _s) __COPYRIGHT(_s)
#ifndef __lint__
#define __link_set_make_entry(set, sym) \
static void const * const __link_set_##set##_sym_##sym \
__section("link_set_" #set) __used = (const void *)&sym
#define __link_set_make_entry2(set, sym, n) \
static void const * const __link_set_##set##_sym_##sym##_##n \
__section("link_set_" #set) __used = (const void *)&sym[n]
#else
#define __link_set_make_entry(set, sym) \
extern void const * const __link_set_##set##_sym_##sym
#define __link_set_make_entry2(set, sym, n) \
extern void const * const __link_set_##set##_sym_##sym##_##n
#endif /* __lint__ */
#define __link_set_add_text(set, sym) __link_set_make_entry(set, sym)
#define __link_set_add_rodata(set, sym) __link_set_make_entry(set, sym)
#define __link_set_add_data(set, sym) __link_set_make_entry(set, sym)
#define __link_set_add_bss(set, sym) __link_set_make_entry(set, sym)
#define __link_set_add_text2(set, sym, n) __link_set_make_entry2(set, sym, n)
#define __link_set_add_rodata2(set, sym, n) __link_set_make_entry2(set, sym, n)
#define __link_set_add_data2(set, sym, n) __link_set_make_entry2(set, sym, n)
#define __link_set_add_bss2(set, sym, n) __link_set_make_entry2(set, sym, n)
#define __link_set_start(set) (__start_link_set_##set)
#define __link_set_end(set) (__stop_link_set_##set)
#define __link_set_decl(set, ptype) \
extern ptype * const __link_set_start(set)[] __dso_hidden; \
__asm__(".hidden " __STRING(__stop_link_set_##set)); \
extern ptype * const __link_set_end(set)[] __weak __dso_hidden
#define __link_set_count(set) \
(__link_set_end(set) - __link_set_start(set))
#ifdef _KERNEL
/*
* On multiprocessor systems we can gain an improvement in performance
* by being mindful of which cachelines data is placed in.
*
* __read_mostly:
*
* It makes sense to ensure that rarely modified data is not
* placed in the same cacheline as frequently modified data.
* To mitigate the phenomenon known as "false-sharing" we
* can annotate rarely modified variables with __read_mostly.
* All such variables are placed into the .data.read_mostly
* section in the kernel ELF.
*
* Prime candidates for __read_mostly annotation are variables
* which are hardly ever modified and which are used in code
* hot-paths, e.g. pmap_initialized.
*
* __cacheline_aligned:
*
* Some data structures (mainly locks) benefit from being aligned
* on a cacheline boundary, and having a cacheline to themselves.
* This way, the modification of other data items cannot adversely
* affect the lock and vice versa.
*
* Any variables annotated with __cacheline_aligned will be
* placed into the .data.cacheline_aligned ELF section.
*/
#define __read_mostly \
__attribute__((__section__(".data.read_mostly")))
#define __cacheline_aligned \
__attribute__((__aligned__(COHERENCY_UNIT), \
__section__(".data.cacheline_aligned")))
#endif /* _KERNEL */
#endif /* !_SYS_CDEFS_ELF_H_ */
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