Hello,

people maintaining self-modifying code (obj-c compiler writers, java JIT
compiler writers etc) currently have to guess how to synchronize i-cache and
d-cache on our d-cache machines (or grep through the kernel sources). See
pr 4951 and back-then port-amiga or port-m68k discussions.


So, to close pr 4951, I plan to do something like this. Comments please.

cacheflush.S, to go into libc (or libarch?) on m68k:

/* $NetBSD$ */

/* Copyright (c) 1998 Ignatios Souvatzis. All rights reserved. */

#include <sys/cdefs.h>

	.globl	cerror
ENTRY(_cachectl)
	movl	sp@(4),a1
	movl	sp@(8),d1
        movl	sp@(12),d0
        trap    #12
	tstl	d0
        jne     err
        rts
err:
        jra     cerror

<m68k/cacheflush.h>, also to be included by the sys_machdep.c files to avoid
duplication of the flag definitions:

/* $NetBSD$ */

/* Copyright (c) 1998 Ignatios Souvatzis. All rights reserved. */

#ifndef _M68K_CACHEFLUSH_H_
#define _M68K_CACHEFLUSH_H_

#ifndef _KERNEL

#include <sys/cdefs.h>
#include <sys/types.h>

int _cacheflush __P((void *, size_t, u_int32_t));

#endif /* ! _KERNEL */


#define CC_PURGE        1
#define CC_FLUSH        2
#define CC_IPURGE       4
#define CC_EXTPURGE     0x80000000

#endif /* _M68K_CACHEFLUSH_H_ */


Regards,
	-is