sysarch(2) syscall to sync icache

[Valery Ushakov <uwe%stderr.spb.ru@localhost>]

Re http://gnats.netbsd.org/52260

Does attached patch look ok?  This is only the kernel part, the
lib/libarch counterpart is mechanical.

-uwe

/*	$NetBSD$ */

/*-
 * Copyright (c) 2017 The NetBSD Foundation, Inc.
 * All rights reserved.
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 * modification, are permitted provided that the following conditions
 * are met:
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 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
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 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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#ifndef _SH3_SYSARCH_H_
#define _SH3_SYSARCH_H_

/*
 * Architecture specific syscalls (sh3)
 */
#define SH3_SYNC_ICACHE		0

struct sh3_sync_icache_args {
	uintptr_t	addr;		/* Virtual start address */
	size_t		len;		/* Region size */
};

#ifndef _KERNEL
#include <sys/cdefs.h>

__BEGIN_DECLS
int	sh3_sync_icache(uintptr_t, size_t);
int	sysarch(int, void *);
__END_DECLS
#endif /* !_KERNEL */
#endif /* !_SH3_SYSARCH_H_ */

Index: sys_machdep.c
===================================================================
RCS file: /cvsroot/src/sys/arch/sh3/sh3/sys_machdep.c,v
retrieving revision 1.13
diff -u -p -u -r1.13 sys_machdep.c
--- sys_machdep.c	22 Dec 2007 08:59:02 -0000	1.13
+++ sys_machdep.c	20 Oct 2017 01:00:18 -0000
@@ -80,9 +80,39 @@ __KERNEL_RCSID(0, "$NetBSD: sys_machdep.
 #include <sys/mount.h>
 #include <sys/syscallargs.h>
 
+#include <sh3/sysarch.h>
+#include <sh3/cache.h>
+
 int
 sys_sysarch(struct lwp *l, const struct sys_sysarch_args *uap, register_t *retval)
 {
+	/* {
+		syscallarg(int) op;
+		syscallarg(void *) parms;
+	} */
+	int op;
+	int error = 0;
+
+	op = SCARG(uap, op);
+	switch (op) {
+	case SH3_SYNC_ICACHE: {
+		struct sh3_sync_icache_args args;
+
+		error = copyin(SCARG(uap, parms), &args, sizeof(args));
+		if (error != 0)
+			break;
+
+		if (args.len < (size_t)sh_cache_size_icache)
+			sh_icache_sync_range_index(args.addr, args.len);
+		else
+			sh_icache_sync_all();
+		break;
+	}
+
+	default:
+		error = ENOSYS;
+		break;
+	}
 
-	return (ENOSYS);
+	return error;
 }