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      1 /*	$NetBSD: ras.h,v 1.15 2021/01/11 21:51:20 skrll Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2002, 2004, 2007 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Gregory McGarry.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #ifndef _SYS_RAS_H_
     33 #define _SYS_RAS_H_
     34 
     35 #ifndef __ASSEMBLER__
     36 #include <sys/types.h>
     37 #include <sys/queue.h>
     38 
     39 struct ras {
     40 	struct ras	*ras_next;
     41 	void		*ras_startaddr;
     42 	void		*ras_endaddr;
     43 };
     44 
     45 #define RAS_INSTALL		0
     46 #define RAS_PURGE		1
     47 #define RAS_PURGE_ALL		2
     48 #else
     49 #include <sys/cdefs.h>
     50 #endif /* __ASSEMBLER__ */
     51 
     52 #ifdef _KERNEL
     53 
     54 #ifndef __ASSEMBLER__
     55 struct proc;
     56 
     57 void	*ras_lookup(struct proc *, void *);
     58 int	ras_fork(struct proc *, struct proc *);
     59 int	ras_purgeall(void);
     60 #endif /* __ASSEMBLER__ */
     61 
     62 #else /* !_KERNEL */
     63 
     64 #ifndef	RAS_DECL
     65 
     66 #define	RAS_DECL(name)							\
     67 extern void __CONCAT(name,_ras_start(void)), __CONCAT(name,_ras_end(void))
     68 
     69 #endif	/* RAS_DECL */
     70 
     71 /*
     72  * RAS_START and RAS_END contain implicit instruction reordering
     73  * barriers.  See __insn_barrier() in <sys/cdefs.h>.
     74  *
     75  * Note: You are strongly advised to avoid coding RASs in C. There is a
     76  * good chance the compiler will generate code which cannot be restarted.
     77  */
     78 #define	RAS_START(name)							\
     79 	__asm volatile(".globl " ___STRING(name) "_ras_start\n"	\
     80 			 ___STRING(name) "_ras_start:" 			\
     81 	    ::: "memory")
     82 
     83 #define	RAS_END(name)							\
     84 	__asm volatile(".globl " ___STRING(name) "_ras_end\n"		\
     85 			 ___STRING(name) "_ras_end:"			\
     86 	    ::: "memory")
     87 
     88 #define	RAS_ADDR(name)	((void *)(uintptr_t) __CONCAT(name,_ras_start))
     89 #define	RAS_SIZE(name)	((size_t)((uintptr_t) __CONCAT(name,_ras_end) -	\
     90 				  (uintptr_t) __CONCAT(name,_ras_start)))
     91 
     92 #ifndef __ASSEMBLER__
     93 __BEGIN_DECLS
     94 int rasctl(void *, size_t, int);
     95 __END_DECLS
     96 
     97 #else /* __ASSEMBLER__ */
     98 
     99 #ifndef	_ASM_LS_CHAR
    100 #define	_ASM_LS_CHAR	;
    101 #endif
    102 
    103 /*
    104  * RAS_START_ASM and RAS_END_ASM are for use within assembly code.
    105  * This is the preferred method of coding a RAS.
    106  */
    107 #define	RAS_START_ASM(name)						\
    108 	.globl _C_LABEL(__CONCAT(name,_ras_start))	 _ASM_LS_CHAR	\
    109 	_C_LABEL(__CONCAT(name,_ras_start)):
    110 
    111 #define	RAS_END_ASM(name)						\
    112 	.globl _C_LABEL(__CONCAT(name,_ras_end)) 	_ASM_LS_CHAR	\
    113 	_C_LABEL(__CONCAT(name,_ras_end)):
    114 
    115 /*
    116  * RAS_START_ASM_HIDDEN and RAS_END_ASM_HIDDEN are similar to the above,
    117  * except that they limit the scope of the symbol such that it will not
    118  * be placed into the dynamic symbol table. Thus no other module (executable
    119  * or shared library) can reference it directly.
    120  */
    121 #define	RAS_START_ASM_HIDDEN(name)					\
    122 	.globl _C_LABEL(__CONCAT(name,_ras_start)) 	_ASM_LS_CHAR	\
    123 	.hidden _C_LABEL(__CONCAT(name,_ras_start)) 	_ASM_LS_CHAR	\
    124 	_C_LABEL(__CONCAT(name,_ras_start)):
    125 
    126 #define	RAS_END_ASM_HIDDEN(name)					\
    127 	.globl _C_LABEL(__CONCAT(name,_ras_end)) 	_ASM_LS_CHAR	\
    128 	.hidden _C_LABEL(__CONCAT(name,_ras_end)) 	_ASM_LS_CHAR	\
    129 	_C_LABEL(__CONCAT(name,_ras_end)):
    130 #endif /* __ASSEMBLER__ */
    131 
    132 #endif /* _KERNEL */
    133 
    134 #endif /* !_SYS_RAS_H_ */
    135