LCOM1920-T02G10

/*        $NetBSD: cdefs_elf.h,v 1.49 2015/05/08 13:58:53 christos 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))

#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))

#endif

#if __STDC__

#define        __SECTIONSTRING(_sec, _str)                                        \

        __asm(".pushsection " #_sec "\n"                                \

              ".asciz \"" _str "\"\n"                                        \

              ".popsection")

#else

#define        __SECTIONSTRING(_sec, _str)                                        \

        __asm(".pushsection _sec\n"                                        \

              ".asciz \"" _str "\"\n"                                        \

              ".popsection")

#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;        \

        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_ */