* Factor out the object system from new-bus so that it can be used by

  non-device code.
* Re-implement the method dispatch to improve efficiency. The new system
  takes about 40ns for a method dispatch on a 300Mhz PII which is only
  10ns slower than a direct function call on the same hardware.

This changes the new-bus ABI slightly so make sure you re-compile any
driver modules which you use.

5 files changed, 708 insertions, 194 deletions

diff --git a/sys/kern/bus_if.m b/sys/kern/bus_if.m
index e555462..48d4dc8 100644
--- a/sys/kern/bus_if.m
+++ b/sys/kern/bus_if.m
@@ -26,6 +26,8 @@
 # $FreeBSD$
 #
 
+#include <sys/bus.h>
+
 INTERFACE bus;
 
 #
diff --git a/sys/kern/device_if.m b/sys/kern/device_if.m
index 1d6215b..005eb38 100644
--- a/sys/kern/device_if.m
+++ b/sys/kern/device_if.m
@@ -26,6 +26,8 @@
 # $FreeBSD$
 #
 
+#include <sys/bus.h>
+
 INTERFACE device;
 
 #
diff --git a/sys/kern/makeobjops.pl b/sys/kern/makeobjops.pl
new file mode 100644
index 0000000..951c9df
--- /dev/null
+++ b/sys/kern/makeobjops.pl
@@ -0,0 +1,481 @@
+#!/usr/bin/perl
+#
+# Copyright (c) 1992, 1993
+#        The Regents of the University of California.  All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    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
+#    documentation and/or other materials provided with the distribution.
+# 3. All advertising materials mentioning features or use of this software
+#    must display the following acknowledgement:
+#        This product includes software developed by the University of
+#        California, Berkeley and its contributors.
+# 4. Neither the name of the University nor the names of its contributors
+#    may be used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+# From @(#)vnode_if.sh        8.1 (Berkeley) 6/10/93
+# From @(#)makedevops.sh 1.1 1998/06/14 13:53:12 dfr Exp $
+# From @(#)makedevops.sh ?.? 1998/10/05
+# From src/sys/kern/makedevops.pl,v 1.12 1999/11/22 14:40:04 n_hibma Exp
+#
+# $FreeBSD$
+
+#
+# Script to produce kobj front-end sugar.
+#
+
+$debug = 0;
+$cfile = 0;          # by default do not produce any file type
+$hfile = 0;
+
+$keepcurrentdir = 1;
+
+$line_width = 80;
+
+# Process the command line
+#
+while ( $arg = shift @ARGV ) {
+   if ( $arg eq '-c' ) {
+      warn "Producing .c output files"
+         if $debug;
+      $cfile = 1;
+   } elsif ( $arg eq '-h' ) {
+      warn "Producing .h output files"
+         if $debug;
+      $hfile = 1;
+   } elsif ( $arg eq '-ch' || $arg eq '-hc' ) {
+      warn "Producing .c and .h output files"
+         if $debug;
+      $cfile = 1;
+      $hfile = 1;
+   } elsif ( $arg eq '-d' ) {
+      $debug = 1;
+   } elsif ( $arg eq '-p' ) {
+      warn "Will produce files in original not in current directory"
+         if $debug;
+      $keepcurrentdir = 0;
+   } elsif ( $arg eq '-l' ) {
+      if ( $line_width = shift @ARGV and $line_width > 0 ) {
+         warn "Line width set to $line_width"
+            if $debug;
+      } else {
+         die "Please specify a valid line width after -l";
+      }
+   } elsif ( $arg =~ m/\.m$/ ) {
+      warn "Filename: $arg"
+         if $debug;
+      push @filenames, $arg;
+   } else {
+      warn "$arg ignored"
+         if $debug;
+   }
+}
+
+
+# Validate the command line parameters
+#
+die "usage: $0 [-d] [-p] [-l <nr>] [-c|-h] srcfile
+where -c   produce only .c files
+      -h   produce only .h files
+      -p   use the path component in the source file for destination dir
+      -l   set line width for output files [80]
+      -d   switch on debugging
+"
+        unless ($cfile or $hfile)
+           and $#filenames != -1;
+
+# FIXME should be able to do this more easily
+#
+$tmpdir = $ENV{'TMPDIR'};           # environment variables
+$tmpdir = $ENV{'TMP'}
+   if !$tmpdir;
+$tmpdir = $ENV{'TEMP'}
+   if !$tmpdir;
+$tmpdir = '/tmp'                    # look for a physical directory
+   if !$tmpdir and -d '/tmp';
+$tmpdir = '/usr/tmp'
+   if !$tmpdir and -d '/usr/tmp';
+$tmpdir = '/var/tmp'
+   if !$tmpdir and -d '/var/tmp';
+$tmpdir = '.'                       # give up and use current dir
+   if !$tmpdir;
+
+foreach $src ( @filenames ) {
+   # Names of the created files
+   $ctmpname = "$tmpdir/ctmp.$$";
+   $htmpname = "$tmpdir/htmp.$$";
+
+   ($name, $path, $suffix) = &fileparse($src, '.m');
+   $path = '.'
+      if $keepcurrentdir;
+   $cfilename="$path/$name.c";
+   $hfilename="$path/$name.h";
+
+   warn "Processing from $src to $cfilename / $hfilename via $ctmpname / $htmpname"
+      if $debug;
+
+   die "Could not open $src, $!"
+      if !open SRC, "$src";
+   die "Could not open $ctmpname, $!"
+      if $cfile and !open CFILE, ">$ctmpname";
+   die "Could not open $htmpname, $!"
+      if $hfile and !open HFILE, ">$htmpname";
+
+   if ($cfile) {
+      # Produce the header of the C file
+      #
+      print CFILE "/*\n";
+      print CFILE " * This file is produced automatically.\n";
+      print CFILE " * Do not modify anything in here by hand.\n";
+      print CFILE " *\n";
+      print CFILE " * Created from source file\n";
+      print CFILE " *   $src\n";
+      print CFILE " * with\n";
+      print CFILE " *   $0\n";
+      print CFILE " *\n";
+      print CFILE " * See the source file for legal information\n";
+      print CFILE " */\n";
+      print CFILE "\n";
+      print CFILE "#include <sys/param.h>\n";
+      print CFILE "#include <sys/queue.h>\n";
+      print CFILE "#include <sys/kernel.h>\n";
+      print CFILE "#include <sys/kobj.h>\n";
+   }
+
+   if ($hfile) {
+      # Produce the header of the H file
+      #
+      print HFILE "/*\n";
+      print HFILE " * This file is produced automatically.\n";
+      print HFILE " * Do not modify anything in here by hand.\n";
+      print HFILE " *\n";
+      print HFILE " * Created from source file\n";
+      print HFILE " *   $src\n";
+      print HFILE " * with\n";
+      print HFILE " *   $0\n";
+      print HFILE " *\n";
+      print HFILE " * See the source file for legal information\n";
+      print HFILE " */\n";
+      print HFILE "\n";
+   }
+
+   %methods = ();    # clear list of methods
+   @mnames = ();
+   @defaultmethods = ();
+   $lineno = 0;
+   $error = 0;       # to signal clean up and gerror setting
+
+   LINE:
+   while ( $line = <SRC> ) {
+       $lineno++;
+       
+       # take special notice of include directives.
+       #
+       if ( $line =~ m/^#\s*include\s+(["<])([^">]+)([">]).*/i ) {
+	    warn "Included file: $1$2" . ($1 eq '<'? '>':'"')
+            if $debug;
+	    print CFILE "#include $1$2" . ($1 eq '<'? '>':'"') . "\n"
+            if $cfile;
+       }
+       
+       $line =~ s/#.*//;                # remove comments
+	 $line =~ s/^\s+//;               # remove leading ...
+       $line =~ s/\s+$//;               # remove trailing whitespace
+       
+       if ( $line =~ m/^$/ ) {          # skip empty lines
+	   # nop
+	   
+       } elsif ( $line =~ m/^INTERFACE\s*([^\s;]*)(\s*;?)/i ) {
+	   $intname = $1;
+	   $semicolon = $2;
+	   unless ( $intname =~ m/^[a-z_][a-z0-9_]*$/ ) {
+	       warn $line
+		 if $debug;
+	       warn "$src:$lineno: Invalid interface name '$intname', use [a-z_][a-z0-9_]*";
+	       $error = 1;
+	       last LINE;
+	   }
+	   
+	   warn "$src:$lineno: semicolon missing at end of line, no problem"
+	     if $semicolon !~ s/;$//;
+	   
+	   warn "Interface $intname"
+	     if $debug;
+	   
+	   print HFILE '#ifndef _'.$intname."_if_h_\n"
+	     if $hfile;
+	   print HFILE '#define _'.$intname."_if_h_\n\n"
+	     if $hfile;
+	   print CFILE '#include "'.$intname.'_if.h"'."\n\n"
+	     if $cfile;
+       } elsif ( $line =~ m/^CODE\s*{$/i ) {
+	   $code = "";
+	   $line = <SRC>;
+	   $line =~ m/^(\s*)/;
+	   $indent = $1;           # find the indent used
+	   while ( $line !~ m/^}/ ) {
+	   $line =~ s/^$indent//g; # remove the indent
+	   $code .= $line;
+	   $line = <SRC>;
+	   $lineno++
+       }
+		 if ($cfile) {
+		     print CFILE "\n".$code."\n";
+		 }
+	    } elsif ( $line =~ m/^HEADER\s*{$/i ) {
+		$header = "";
+		$line = <SRC>;
+		$line =~ m/^(\s*)/;
+		$indent = $1;              # find the indent used
+		while ( $line !~ m/^}/ ) {
+		$line =~ s/^$indent//g; # remove the indent
+		$header .= $line;
+		$line = <SRC>;
+		$lineno++
+	    }
+		      if ($hfile) {
+			  print HFILE $header;
+		      }
+		 } elsif ( $line =~ m/^(STATIC|)METHOD/i ) {
+		     # Get the return type function name and delete that from
+		     # the line. What is left is the possibly first function argument
+		     # if it is on the same line.
+		     #
+		     if ( !$intname ) {
+			 warn "$src:$lineno: No interface name defined";
+			 $error = 1;
+			 last LINE;
+		     }
+		     $line =~ s/^(STATIC|)METHOD\s+([^\{]+?)\s*\{\s*//i;
+		     $static = $1;                                                    
+		     @ret = split m/\s+/, $2;
+		     $name = pop @ret;          # last element is name of method
+		     $ret = join(" ", @ret);    # return type
+		     
+		     warn "Method: name=$name return type=$ret"
+		       if $debug;
+		     
+		     if ( !$name or !$ret ) {
+			 warn $line
+			   if $debug;
+			 warn "$src:$lineno: Invalid method specification";
+			 $error = 1;
+			 last LINE;
+		     }
+		     
+		     unless ( $name =~ m/^[a-z_][a-z_0-9]*$/ ) {
+			 warn $line
+			   if $debug;
+			 warn "$src:$lineno: Invalid method name '$name', use [a-z_][a-z0-9_]*";
+			 $error = 1;
+			 last LINE;
+		     }
+		     
+		     if ( defined($methods{$name}) ) {
+			 warn "$src:$lineno: Duplicate method name";
+			 $error = 1;
+			 last LINE;
+		     }
+		     
+		     $methods{$name} = $name;
+		     push @mnames, $name;
+		     
+		     while ( $line !~ m/}/ and $line .= <SRC> ) {
+		     $lineno++
+		 }
+       
+       $default = "";
+       if ( $line !~ s/};?(.*)// ) { # remove first '}' and trailing garbage
+       # The '}' was not there (the rest is optional), so complain
+       warn "$src:$lineno: Premature end of file";
+       $error = 1;
+       last LINE;
+   }
+   $extra = $1;
+   if ( $extra =~ /\s*DEFAULT\s*([a-zA-Z_][a-zA-Z_0-9]*)\s*;/ ) {
+       $default = $1;
+   } else {
+       warn "$src:$lineno: Ignored '$1'"  # warn about garbage at end of line
+	 if $debug and $1;
+   }
+   
+   # Create a list of variables without the types prepended
+   #
+   $line =~ s/^\s+//;            # remove leading ...
+   $line =~ s/\s+$//;            # ... and trailing whitespace
+   $line =~ s/\s+/ /g;           # remove double spaces
+   
+   @arguments = split m/\s*;\s*/, $line;
+   @varnames = ();               # list of varnames
+   foreach $argument (@arguments) {
+       next                       # skip argument if argument is empty
+	 if !$argument;
+
+       @ar = split m/[*\s]+/, $argument;
+       if ( $#ar == 0 ) {         # only 1 word in argument?
+	   warn "$src:$lineno: no type for '$argument'";
+	   $error = 1;
+	   last LINE;
+       }
+       
+       push @varnames, $ar[-1];   # last element is name of variable
+   };
+   
+   warn 'Arguments: ' . join(', ', @arguments) . "\n"
+     . 'Varnames: ' . join(', ', @varnames)
+       if $debug;
+   
+   $mname = $intname.'_'.$name;  # method name
+   $umname = uc($mname);         # uppercase method name
+   
+   $arguments = join(", ", @arguments);
+   $firstvar = $varnames[0];
+   $varnames = join(", ", @varnames);
+   
+   $default = "0" if $default eq "";
+   push @defaultmethods, $default;
+   
+   if ($hfile) {
+       # the method description 
+       print HFILE "extern struct kobjop_desc $mname\_desc;\n";
+       # the method typedef
+       print HFILE &format_line("typedef $ret $mname\_t($arguments);",
+				$line_width, ', ',
+				',',' ' x length("typedef $ret $mname\_t("))
+	 . "\n";
+   }
+   
+   if ($cfile) {
+       # Print out the method desc
+       print CFILE "struct kobjop_desc $mname\_desc = {\n";
+       print CFILE "\t0, (kobjop_t) $default\n";
+       print CFILE "};\n\n";
+   }
+   
+   if ($hfile) {
+       # Print out the method itself
+       if (0) {                 # haven't chosen the format yet
+	   print HFILE "static __inline $ret $umname($varnames)\n";
+	   print HFILE "\t".join(";\n\t", @arguments).";\n";
+       } else {
+	   print HFILE &format_line("static __inline $ret $umname($arguments)",
+				    $line_width, ', ',
+				    ',', ' ' x length("$ret $umname(")) . "\n";
+       }
+       print HFILE "{\n";
+       print HFILE "\tkobjop_t _m;\n";
+       if ( $static ) {
+	   print HFILE "\tKOBJOPLOOKUP($firstvar->ops,$mname);\n";
+       } else {
+	   print HFILE "\tKOBJOPLOOKUP(((kobj_t)$firstvar)->ops,$mname);\n";
+       }
+       print HFILE "\t";
+       if ($ret ne 'void') {
+	   print HFILE "return ";
+       }
+       print HFILE "(($mname\_t *) _m)($varnames);\n";
+       print HFILE "}\n\n";
+   }
+} else {
+    warn $line
+      if $debug;
+    warn "$src:$lineno: Invalid line encountered";
+    $error = 1;
+    last LINE;
+}
+} # end LINE
+
+# print the final '#endif' in the header file
+#
+print HFILE "#endif /* _".$intname."_if_h_ */\n"
+  if $hfile;
+
+close SRC;
+close CFILE
+  if $cfile;
+close HFILE
+  if $hfile;
+
+if ( !$error ) {
+    if ($cfile) {
+	($rc = system("mv $ctmpname $cfilename"))
+	  and warn "mv $ctmpname $cfilename failed, $rc";
+    }
+    
+    if ($hfile) {
+	($rc = system("mv $htmpname $hfilename"))
+	  and warn "mv $htmpname $hfilename failed, $rc";
+    }
+} else {
+    warn 'Output skipped';
+    ($rc = system("rm -f $htmpname $ctmpname"))
+      and warn "rm -f $htmpname $ctmpname failed, $rc";
+    $gerror = 1;
+}
+}
+
+exit $gerror;
+
+
+sub format_line {
+    my ($line, $maxlength, $break, $new_end, $new_start) = @_;
+    my $rline = "";
+    
+    while ( length($line) > $maxlength
+	    and ($i = rindex $line, $break, $maxlength-length($new_end)) != -1 ) {
+	$rline .= substr($line, 0, $i) . $new_end . "\n";
+	$line = $new_start . substr($line, $i+length($break));
+    }
+    
+    return $rline . $line;
+}
+
+# This routine is a crude replacement for one in File::Basename. We
+# cannot use any library code because it fouls up the Perl bootstrap
+# when we update a perl version. MarkM
+
+sub fileparse {
+    my ($filename, @suffix) = @_;
+    my ($dir, $name, $type, $i);
+    
+    $type = '';
+    foreach $i (@suffix) {
+	if ($filename =~ m|$i$|) {
+	    $filename =~ s|$i$||;
+	    $type = $i;
+	}
+    }
+    if ($filename =~ m|/|) {
+	$filename =~ m|([^/]*)$|;
+	$name = $1;
+	$dir = $filename;
+	$dir =~ s|$name$||;
+    }
+    else {
+	$dir = '';
+	$name = $filename;
+    }
+    ($name, $dir, $type);
+}
+
+sub write_interface {
+    $mcount = $#mnames + 1;
+}
diff --git a/sys/kern/subr_bus.c b/sys/kern/subr_bus.c
index 7492a4b..dbcf4ee 100644
--- a/sys/kern/subr_bus.c
+++ b/sys/kern/subr_bus.c
@@ -36,6 +36,7 @@
 #ifdef DEVICE_SYSCTLS
 #include <sys/sysctl.h>
 #endif
+#include <sys/kobj.h>
 #include <sys/bus_private.h>
 #include <sys/systm.h>
 #include <machine/bus.h>
@@ -56,7 +57,6 @@ MALLOC_DEFINE(M_BUS, "bus", "Bus data structures");
 #define indentprintf(p)	do { int iJ; printf("."); for (iJ=0; iJ<indent; iJ++) printf("  "); printf p ; } while(0)
 
 static void print_method_list(device_method_t *m, int indent);
-static void print_device_ops(device_ops_t ops, int indent);
 static void print_device_short(device_t dev, int indent);
 static void print_device(device_t dev, int indent);
 void print_device_tree_short(device_t dev, int indent);
@@ -77,7 +77,6 @@ void print_devclass_list(void);
 #define DEVCLANAME(d)			/* nop */
 
 #define print_method_list(m,i)		/* nop */
-#define print_device_ops(o,i)		/* nop */
 #define print_device_short(d,i)		/* nop */
 #define print_device(d,i)		/* nop */
 #define print_device_tree_short(d,i)	/* nop */
@@ -96,146 +95,11 @@ static void device_register_oids(device_t dev);
 static void device_unregister_oids(device_t dev);
 #endif
 
-/*
- * Method table handling
- */
-static int error_method(void);
-static int next_method_offset = 1;
-
-LIST_HEAD(methodlist, method) methods;
-struct method {
-    LIST_ENTRY(method) link;	/* linked list of methods */
-    int offset;			/* offset in method table */
-    int refs;			/* count of device_op_desc users */
-    devop_t deflt;		/* default implementation */
-    char* name;			/* unique name of method */
+kobj_method_t null_methods[] = {
+    { 0, 0 }
 };
 
-static void
-register_method(struct device_op_desc *desc)
-{
-    struct method* m;
-
-    if (desc->method) {
-	desc->method->refs++;
-	return;
-    }
-
-    /*
-     * Make sure that desc->deflt is always valid to simplify dispatch.
-     */
-    if (!desc->deflt)
-	desc->deflt = error_method;
-
-    for (m = LIST_FIRST(&methods); m; m = LIST_NEXT(m, link)) {
-	if (!strcmp(m->name, desc->name)) {
-	    desc->offset = m->offset;
-	    desc->method = m;
-	    m->refs++;
-	    PDEBUG(("method %p has the same name, %s, with offset %d",
-		    (void *)m, desc->name, desc->offset));
-	    return;
-	}
-    }
-
-    m = (struct method *) malloc(sizeof(struct method)
-				 + strlen(desc->name) + 1,
-				 M_BUS, M_NOWAIT);
-    if (!m)
-	    panic("register_method: out of memory");
-    bzero(m, sizeof(struct method) + strlen(desc->name) + 1);
-    m->offset = next_method_offset++;
-    m->refs = 1;
-    m->deflt = desc->deflt;
-    m->name = (char*) (m + 1);
-    strcpy(m->name, desc->name);
-    LIST_INSERT_HEAD(&methods, m, link);
-
-    desc->offset = m->offset;
-    desc->method = m;
-}
-
-static void
-unregister_method(struct device_op_desc *desc)
-{
-    struct method *m = desc->method;
-    m->refs--;
-    if (m->refs == 0) {
-	PDEBUG(("method %s, reached refcount 0", desc->name));
-	LIST_REMOVE(m, link);
-	free(m, M_BUS);
-    	desc->method = 0;
-    }
-}
-
-static int error_method(void)
-{
-    return ENXIO;
-}
-
-static struct device_ops null_ops = {
-    1, 
-    { error_method }
-};
-
-static void
-compile_methods(driver_t *driver)
-{
-    device_ops_t ops;
-    struct device_method *m;
-    struct method *cm;
-    int i;
-
-    /*
-     * First register any methods which need it.
-     */
-    for (i = 0, m = driver->methods; m->desc; i++, m++)
-	register_method(m->desc);
-
-    /*
-     * Then allocate the compiled op table.
-     */
-    ops = malloc(sizeof(struct device_ops) + (next_method_offset-1) * sizeof(devop_t),
-		 M_BUS, M_NOWAIT);
-    if (!ops)
-	panic("compile_methods: out of memory");
-    bzero(ops, sizeof(struct device_ops) + (next_method_offset-1) * sizeof(devop_t));
-
-    ops->maxoffset = next_method_offset;
-    /* Fill in default methods and then overwrite with driver methods */
-    for (i = 0; i < next_method_offset; i++)
-	ops->methods[i] = error_method;
-    for (cm = LIST_FIRST(&methods); cm; cm = LIST_NEXT(cm, link)) {
-	if (cm->deflt)
-	    ops->methods[cm->offset] = cm->deflt;
-    }
-    for (i = 0, m = driver->methods; m->desc; i++, m++)
-	ops->methods[m->desc->offset] = m->func;
-    PDEBUG(("%s has %d method%s, wasting %d bytes",
-    		DRIVERNAME(driver), i, (i==1?"":"s"),
-		(next_method_offset-i)*sizeof(devop_t)));
-
-    driver->ops = ops;
-}
-
-static void
-free_methods(driver_t *driver)
-{
-    int i;
-    struct device_method *m;
-
-    /*
-     * Unregister any methods which are no longer used.
-     */
-    for (i = 0, m = driver->methods; m->desc; i++, m++)
-	unregister_method(m->desc);
-
-    /*
-     * Free memory and clean up.
-     */
-    free(driver->ops, M_BUS);
-    driver->ops = 0;
-}
+DEFINE_CLASS(null, null_methods, 0);
 
 /*
  * Devclass implementation
@@ -302,8 +166,7 @@ devclass_add_driver(devclass_t dc, driver_t *driver)
     /*
      * Compile the driver's methods.
      */
-    if (!driver->ops)
-	compile_methods(driver);
+    kobj_class_compile((kobj_class_t) driver);
 
     /*
      * Make sure the devclass which the driver is implementing exists.
@@ -379,7 +242,7 @@ devclass_delete_driver(devclass_t busclass, driver_t *driver)
 
     driver->refs--;
     if (driver->refs == 0)
-	free_methods(driver);
+	kobj_class_free((kobj_class_t) driver);
 
     return 0;
 }
@@ -609,7 +472,7 @@ make_device(device_t parent, const char *name, int unit)
 
     dev->parent = parent;
     TAILQ_INIT(&dev->children);
-    dev->ops = &null_ops;
+    kobj_init((kobj_t) dev, &null_class);
     dev->driver = NULL;
     dev->devclass = NULL;
     dev->unit = unit;
@@ -630,6 +493,8 @@ make_device(device_t parent, const char *name, int unit)
 
     dev->state = DS_NOTPRESENT;
 
+    kobj_init((kobj_t) dev, &null_class);
+
     return dev;
 }
 
@@ -1112,18 +977,19 @@ device_set_driver(device_t dev, driver_t *driver)
 	free(dev->softc, M_BUS);
 	dev->softc = NULL;
     }
-    dev->ops = &null_ops;
+    kobj_delete((kobj_t) dev, 0);
     dev->driver = driver;
     if (driver) {
-	dev->ops = driver->ops;
-	dev->softc = malloc(driver->softc, M_BUS, M_NOWAIT);
+	kobj_init((kobj_t) dev, (kobj_class_t) driver);
+	dev->softc = malloc(driver->size, M_BUS, M_NOWAIT);
 	if (!dev->softc) {
-	    dev->ops = &null_ops;
+	    kobj_init((kobj_t) dev, &null_class);
 	    dev->driver = NULL;
 	    return ENOMEM;
 	}
-	bzero(dev->softc, driver->softc);
-    }
+	bzero(dev->softc, driver->size);
+    } else
+	kobj_init((kobj_t) dev, &null_class);
     return 0;
 }
 
@@ -2180,17 +2046,17 @@ root_setup_intr(device_t dev, device_t child, driver_intr_t *intr, void *arg,
 	panic("root_setup_intr");
 }
 
-static device_method_t root_methods[] = {
+static kobj_method_t root_methods[] = {
 	/* Device interface */
-	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
-	DEVMETHOD(device_suspend,	bus_generic_suspend),
-	DEVMETHOD(device_resume,	bus_generic_resume),
+	KOBJMETHOD(device_shutdown,	bus_generic_shutdown),
+	KOBJMETHOD(device_suspend,	bus_generic_suspend),
+	KOBJMETHOD(device_resume,	bus_generic_resume),
 
 	/* Bus interface */
-	DEVMETHOD(bus_print_child,	root_print_child),
-	DEVMETHOD(bus_read_ivar,	bus_generic_read_ivar),
-	DEVMETHOD(bus_write_ivar,	bus_generic_write_ivar),
-	DEVMETHOD(bus_setup_intr,	root_setup_intr),
+	KOBJMETHOD(bus_print_child,	root_print_child),
+	KOBJMETHOD(bus_read_ivar,	bus_generic_read_ivar),
+	KOBJMETHOD(bus_write_ivar,	bus_generic_write_ivar),
+	KOBJMETHOD(bus_setup_intr,	root_setup_intr),
 
 	{ 0, 0 }
 };
@@ -2209,10 +2075,10 @@ root_bus_module_handler(module_t mod, int what, void* arg)
 {
     switch (what) {
     case MOD_LOAD:
-	compile_methods(&root_driver);
+	kobj_class_compile((kobj_class_t) &root_driver);
 	root_bus = make_device(NULL, "root", 0);
 	root_bus->desc = "System root bus";
-	root_bus->ops = root_driver.ops;
+	kobj_init((kobj_t) root_bus, (kobj_class_t) &root_driver);
 	root_bus->driver = &root_driver;
 	root_bus->state = DS_ATTACHED;
 	root_devclass = devclass_find_internal("root", FALSE);
@@ -2318,36 +2184,6 @@ print_method_list(device_method_t *m, int indent)
 }
 
 static void
-print_device_ops(device_ops_t ops, int indent)
-{
-	int i;
-	int count = 0;
-
-	if (!ops)
-		return;
-
-	/* we present a list of the methods that are pointing to the
-	 * error_method, but ignore the 0'th elements; it is always
-	 * error_method.
-	 */
-	for (i = 1; i < ops->maxoffset; i++) {
-		if (ops->methods[i] == error_method) {
-			if (count == 0)
-				indentprintf(("error_method:"));
-			printf(" %d", i);
-			count++;
-		}
-	}
-	if (count)
-		printf("\n");
-
-	indentprintf(("(%d method%s, %d valid, %d error_method%s)\n",
-		ops->maxoffset-1, (ops->maxoffset-1 == 1? "":"s"),
-		ops->maxoffset-1-count,
-		count, (count == 1? "":"'s")));
-}
-
-static void
 print_device_short(device_t dev, int indent)
 {
 	if (!dev)
@@ -2376,8 +2212,6 @@ print_device(device_t dev, int indent)
 
 	indentprintf(("Parent:\n"));
 	print_device_short(dev->parent, indent+1);
-	indentprintf(("Methods:\n"));
-	print_device_ops(dev->ops, indent+1);
 	indentprintf(("Driver:\n"));
 	print_driver_short(dev->driver, indent+1);
 	indentprintf(("Devclass:\n"));
@@ -2435,8 +2269,6 @@ print_driver(driver_t *driver, int indent)
 	print_driver_short(driver, indent);
 	indentprintf(("Methods:\n"));
 	print_method_list(driver->methods, indent+1);
-	indentprintf(("Operations:\n"));
-	print_device_ops(driver->ops, indent+1);
 }
 
 
diff --git a/sys/kern/subr_kobj.c b/sys/kern/subr_kobj.c
new file mode 100644
index 0000000..9a2eafb
--- /dev/null
+++ b/sys/kern/subr_kobj.c
@@ -0,0 +1,197 @@
+/*-
+ * Copyright (c) 2000 Doug Rabson
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    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
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	$FreeBSD$
+ */
+
+#include <sys/param.h>
+#include <sys/queue.h>
+#include <sys/malloc.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+#include <sys/errno.h>
+#ifndef TEST
+#include <sys/systm.h>
+#endif
+#include <sys/kobj.h>
+
+#ifdef TEST
+#include "usertest.h"
+#endif
+
+static MALLOC_DEFINE(M_KOBJ, "kobj", "Kernel object structures");
+
+#ifdef KOBJ_STATS
+
+#include <sys/sysctl.h>
+
+int kobj_lookup_hits;
+int kobj_lookup_misses;
+
+SYSCTL_INT(_kern, OID_AUTO, kobj_hits, CTLFLAG_RD,
+	   &kobj_lookup_hits, 0, "")
+SYSCTL_INT(_kern, OID_AUTO, kobj_misses, CTLFLAG_RD,
+	   &kobj_lookup_misses, 0, "")
+
+#endif
+
+static int kobj_next_id = 1;
+
+static int
+kobj_error_method(void)
+{
+	return ENXIO;
+}
+
+static void
+kobj_register_method(struct kobjop_desc *desc)
+{
+	if (desc->id == 0)
+		desc->id = kobj_next_id++;
+}
+
+static void
+kobj_unregister_method(struct kobjop_desc *desc)
+{
+}
+
+void
+kobj_class_compile(kobj_class_t cls)
+{
+	kobj_ops_t ops;
+	kobj_method_t *m;
+	int i;
+
+	/*
+	 * Don't do anything if we are already compiled.
+	 */
+	if (cls->ops)
+		return;
+
+	/*
+	 * First register any methods which need it.
+	 */
+	for (i = 0, m = cls->methods; m->desc; i++, m++)
+		kobj_register_method(m->desc);
+
+	/*
+	 * Then allocate the compiled op table.
+	 */
+	ops = malloc(sizeof(struct kobj_ops), M_KOBJ, M_NOWAIT);
+	if (!ops)
+		panic("kobj_compile_methods: out of memory");
+	bzero(ops, sizeof(struct kobj_ops));
+	ops->cls = cls;
+	cls->ops = ops;
+}
+
+void
+kobj_lookup_method(kobj_method_t *methods,
+		   kobj_method_t *ce,
+		   kobjop_desc_t desc)
+{
+	ce->desc = desc;
+	for (; methods && methods->desc; methods++) {
+		if (methods->desc == desc) {
+			ce->func = methods->func;
+			return;
+		}
+	}
+	if (desc->deflt)
+		ce->func = desc->deflt;
+	else
+		ce->func = kobj_error_method;
+	return;
+}
+
+void
+kobj_class_free(kobj_class_t cls)
+{
+	int i;
+	kobj_method_t *m;
+
+	/*
+	 * Unregister any methods which are no longer used.
+	 */
+	for (i = 0, m = cls->methods; m->desc; i++, m++)
+		kobj_unregister_method(m->desc);
+
+	/*
+	 * Free memory and clean up.
+	 */
+	free(cls->ops, M_KOBJ);
+	cls->ops = 0;
+}
+
+kobj_t
+kobj_create(kobj_class_t cls,
+	    struct malloc_type *mtype,
+	    int mflags)
+{
+	kobj_t obj;
+
+	/*
+	 * Allocate and initialise the new object.
+	 */
+	obj = malloc(cls->size, mtype, mflags);
+	if (!obj)
+		return 0;
+	bzero(obj, cls->size);
+	kobj_init(obj, cls);
+
+	return obj;
+}
+
+void
+kobj_init(kobj_t obj, kobj_class_t cls)
+{
+	/*
+	 * Consider compiling the class' method table.
+	 */
+	if (!cls->ops)
+		kobj_class_compile(cls);
+
+	obj->ops = cls->ops;
+	cls->instances++;
+}
+
+void
+kobj_delete(kobj_t obj, struct malloc_type *mtype)
+{
+	kobj_class_t cls = obj->ops->cls;
+
+	/*
+	 * Consider freeing the compiled method table for the class
+	 * after its last instance is deleted. As an optimisation, we
+	 * should defer this for a short while to avoid thrashing.
+	 */
+	cls->instances--;
+	if (!cls->instances)
+		kobj_class_free(cls);
+
+	obj->ops = 0;
+	if (mtype)
+		free(obj, mtype);
+}