209 lines
6.8 KiB
C
209 lines
6.8 KiB
C
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/* $NetBSD: cdefs_elf.h,v 1.34 2010/12/08 01:18:55 joerg Exp $ */
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/*
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* Copyright (c) 1995, 1996 Carnegie-Mellon University.
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* All rights reserved.
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*
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* Author: Chris G. Demetriou
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*
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* Permission to use, copy, modify and distribute this software and
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* its documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation.
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*
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* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
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* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
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* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
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*
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* Carnegie Mellon requests users of this software to return to
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*
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* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
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* School of Computer Science
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* Carnegie Mellon University
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* Pittsburgh PA 15213-3890
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*
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* any improvements or extensions that they make and grant Carnegie the
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* rights to redistribute these changes.
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*/
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#ifndef _SYS_CDEFS_ELF_H_
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#define _SYS_CDEFS_ELF_H_
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#ifdef __LEADING_UNDERSCORE
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#define _C_LABEL(x) __CONCAT(_,x)
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#define _C_LABEL_STRING(x) "_"x
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#else
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#define _C_LABEL(x) x
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#define _C_LABEL_STRING(x) x
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#endif
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#if __STDC__
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#define ___RENAME(x) __asm(___STRING(_C_LABEL(x)))
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#else
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#ifdef __LEADING_UNDERSCORE
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#define ___RENAME(x) ____RENAME(_/**/x)
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#define ____RENAME(x) __asm(___STRING(x))
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#else
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#define ___RENAME(x) __asm(___STRING(x))
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#endif
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#endif
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#define __indr_reference(sym,alias) /* nada, since we do weak refs */
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#if __STDC__
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#define __strong_alias(alias,sym) \
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__asm(".global " _C_LABEL_STRING(#alias) "\n" \
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_C_LABEL_STRING(#alias) " = " _C_LABEL_STRING(#sym));
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#define __weak_alias(alias,sym) \
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__asm(".weak " _C_LABEL_STRING(#alias) "\n" \
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_C_LABEL_STRING(#alias) " = " _C_LABEL_STRING(#sym));
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/* Do not use __weak_extern, use __weak_reference instead */
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#define __weak_extern(sym) \
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__asm(".weak " _C_LABEL_STRING(#sym));
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#if __GNUC_PREREQ__(4, 0) && !defined(__minix)
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#define __weak_reference(sym) __attribute__((__weakref__))
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#else
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#define __weak_reference(sym) ; __asm(".weak " _C_LABEL_STRING(#sym))
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#endif
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#if defined(__clang__)
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#define __warn_references(sym,msg) \
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static __attribute__((__used__, __section__(".gnu.warning." #sym))) \
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const char ___CONCAT(__warn_reference_##sym,__COUNTER__)[] = msg;
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#else
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#define __warn_references(sym,msg) \
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__asm(".pushsection .gnu.warning." #sym "\n" \
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".ascii \"" msg "\"\n" \
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".popsection");
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#endif
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#else /* !__STDC__ */
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#ifdef __LEADING_UNDERSCORE
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#define __weak_alias(alias,sym) ___weak_alias(_/**/alias,_/**/sym)
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#define ___weak_alias(alias,sym) \
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__asm(".weak alias\nalias = sym");
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#else
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#define __weak_alias(alias,sym) \
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__asm(".weak alias\nalias = sym");
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#endif
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#ifdef __LEADING_UNDERSCORE
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#define __weak_extern(sym) ___weak_extern(_/**/sym)
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#define ___weak_extern(sym) \
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__asm(".weak sym");
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#else
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#define __weak_extern(sym) \
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__asm(".weak sym");
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#endif
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#define __warn_references(sym,msg) \
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__asm(".pushsection .gnu.warning.sym\n" \
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".ascii \"" msg "\"\n" \
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".popsection");
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#endif /* !__STDC__ */
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#if defined(__clang__)
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#define __SECTIONSTRING(_sec, _str) \
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static __attribute__((__used__, __section__(#_sec))) const char \
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___CONCAT(__sectstr,__COUNTER__)[] = _str
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#elif __STDC__
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#define __SECTIONSTRING(_sec, _str) \
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__asm(".pushsection " #_sec "\n" \
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".asciz \"" _str "\"\n" \
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".popsection")
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#else
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#define __SECTIONSTRING(_sec, _str) \
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__asm(".pushsection _sec\n" \
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".asciz \"" _str "\"\n" \
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".popsection")
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#endif
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#define __IDSTRING(_n,_s) __SECTIONSTRING(.ident,_s)
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#define __RCSID(_s) __IDSTRING(rcsid,_s)
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#define __SCCSID(_s)
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#define __SCCSID2(_s)
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#define __COPYRIGHT(_s) __SECTIONSTRING(.copyright,_s)
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#define __KERNEL_RCSID(_n, _s) __RCSID(_s)
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#define __KERNEL_SCCSID(_n, _s)
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#define __KERNEL_COPYRIGHT(_n, _s) __COPYRIGHT(_s)
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#ifndef __lint__
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#define __link_set_make_entry(set, sym) \
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static void const * const __link_set_##set##_sym_##sym \
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__section("link_set_" #set) __used = &sym
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#define __link_set_make_entry2(set, sym, n) \
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static void const * const __link_set_##set##_sym_##sym##_##n \
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__section("link_set_" #set) __used = &sym[n]
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#else
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#define __link_set_make_entry(set, sym) \
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extern void const * const __link_set_##set##_sym_##sym
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#define __link_set_make_entry2(set, sym, n) \
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extern void const * const __link_set_##set##_sym_##sym##_##n
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#endif /* __lint__ */
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#define __link_set_add_text(set, sym) __link_set_make_entry(set, sym)
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#define __link_set_add_rodata(set, sym) __link_set_make_entry(set, sym)
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#define __link_set_add_data(set, sym) __link_set_make_entry(set, sym)
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#define __link_set_add_bss(set, sym) __link_set_make_entry(set, sym)
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#define __link_set_add_text2(set, sym, n) __link_set_make_entry2(set, sym, n)
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#define __link_set_add_rodata2(set, sym, n) __link_set_make_entry2(set, sym, n)
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#define __link_set_add_data2(set, sym, n) __link_set_make_entry2(set, sym, n)
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#define __link_set_add_bss2(set, sym, n) __link_set_make_entry2(set, sym, n)
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#define __link_set_decl(set, ptype) \
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extern ptype * const __start_link_set_##set[]; \
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extern ptype * const __stop_link_set_##set[] \
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#define __link_set_start(set) (__start_link_set_##set)
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#define __link_set_end(set) (__stop_link_set_##set)
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#define __link_set_count(set) \
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(__link_set_end(set) - __link_set_start(set))
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#ifdef _KERNEL
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/*
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* On multiprocessor systems we can gain an improvement in performance
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* by being mindful of which cachelines data is placed in.
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*
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* __read_mostly:
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*
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* It makes sense to ensure that rarely modified data is not
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* placed in the same cacheline as frequently modified data.
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* To mitigate the phenomenon known as "false-sharing" we
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* can annotate rarely modified variables with __read_mostly.
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* All such variables are placed into the .data.read_mostly
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* section in the kernel ELF.
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*
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* Prime candidates for __read_mostly annotation are variables
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* which are hardly ever modified and which are used in code
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* hot-paths, e.g. pmap_initialized.
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*
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* __cacheline_aligned:
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*
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* Some data structures (mainly locks) benefit from being aligned
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* on a cacheline boundary, and having a cacheline to themselves.
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* This way, the modification of other data items cannot adversely
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* affect the lock and vice versa.
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*
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* Any variables annotated with __cacheline_aligned will be
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* placed into the .data.cacheline_aligned ELF section.
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*/
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#define __read_mostly \
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__attribute__((__section__(".data.read_mostly")))
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#define __cacheline_aligned \
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__attribute__((__aligned__(COHERENCY_UNIT) \
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__section__(".data.cacheline_aligned")))
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#endif /* _KERNEL */
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#endif /* !_SYS_CDEFS_ELF_H_ */
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