Initial import of modified Linux 2.6.28 tree

Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y

1 files changed, 378 insertions, 0 deletions

diff --git a/kernel/timeconst.pl b/kernel/timeconst.pl
new file mode 100644
index 0000000..eb51d76
--- /dev/null
+++ b/kernel/timeconst.pl
@@ -0,0 +1,378 @@
+#!/usr/bin/perl
+# -----------------------------------------------------------------------
+#
+#   Copyright 2007-2008 rPath, Inc. - All Rights Reserved
+#
+#   This file is part of the Linux kernel, and is made available under
+#   the terms of the GNU General Public License version 2 or (at your
+#   option) any later version; incorporated herein by reference.
+#
+# -----------------------------------------------------------------------
+#
+
+#
+# Usage: timeconst.pl HZ > timeconst.h
+#
+
+# Precomputed values for systems without Math::BigInt
+# Generated by:
+# timeconst.pl --can 24 32 48 64 100 122 128 200 250 256 300 512 1000 1024 1200
+%canned_values = (
+	24 => [
+		'0xa6aaaaab','0x2aaaaaa',26,
+		125,3,
+		'0xc49ba5e4','0x1fbe76c8b4',37,
+		3,125,
+		'0xa2c2aaab','0xaaaa',16,
+		125000,3,
+		'0xc9539b89','0x7fffbce4217d',47,
+		3,125000,
+	], 32 => [
+		'0xfa000000','0x6000000',27,
+		125,4,
+		'0x83126e98','0xfdf3b645a',36,
+		4,125,
+		'0xf4240000','0x0',17,
+		31250,1,
+		'0x8637bd06','0x3fff79c842fa',46,
+		1,31250,
+	], 48 => [
+		'0xa6aaaaab','0x6aaaaaa',27,
+		125,6,
+		'0xc49ba5e4','0xfdf3b645a',36,
+		6,125,
+		'0xa2c2aaab','0x15555',17,
+		62500,3,
+		'0xc9539b89','0x3fffbce4217d',46,
+		3,62500,
+	], 64 => [
+		'0xfa000000','0xe000000',28,
+		125,8,
+		'0x83126e98','0x7ef9db22d',35,
+		8,125,
+		'0xf4240000','0x0',18,
+		15625,1,
+		'0x8637bd06','0x1fff79c842fa',45,
+		1,15625,
+	], 100 => [
+		'0xa0000000','0x0',28,
+		10,1,
+		'0xcccccccd','0x733333333',35,
+		1,10,
+		'0x9c400000','0x0',18,
+		10000,1,
+		'0xd1b71759','0x1fff2e48e8a7',45,
+		1,10000,
+	], 122 => [
+		'0x8325c53f','0xfbcda3a',28,
+		500,61,
+		'0xf9db22d1','0x7fbe76c8b',35,
+		61,500,
+		'0x8012e2a0','0x3ef36',18,
+		500000,61,
+		'0xffda4053','0x1ffffbce4217',45,
+		61,500000,
+	], 128 => [
+		'0xfa000000','0x1e000000',29,
+		125,16,
+		'0x83126e98','0x3f7ced916',34,
+		16,125,
+		'0xf4240000','0x40000',19,
+		15625,2,
+		'0x8637bd06','0xfffbce4217d',44,
+		2,15625,
+	], 200 => [
+		'0xa0000000','0x0',29,
+		5,1,
+		'0xcccccccd','0x333333333',34,
+		1,5,
+		'0x9c400000','0x0',19,
+		5000,1,
+		'0xd1b71759','0xfff2e48e8a7',44,
+		1,5000,
+	], 250 => [
+		'0x80000000','0x0',29,
+		4,1,
+		'0x80000000','0x180000000',33,
+		1,4,
+		'0xfa000000','0x0',20,
+		4000,1,
+		'0x83126e98','0x7ff7ced9168',43,
+		1,4000,
+	], 256 => [
+		'0xfa000000','0x3e000000',30,
+		125,32,
+		'0x83126e98','0x1fbe76c8b',33,
+		32,125,
+		'0xf4240000','0xc0000',20,
+		15625,4,
+		'0x8637bd06','0x7ffde7210be',43,
+		4,15625,
+	], 300 => [
+		'0xd5555556','0x2aaaaaaa',30,
+		10,3,
+		'0x9999999a','0x1cccccccc',33,
+		3,10,
+		'0xd0555556','0xaaaaa',20,
+		10000,3,
+		'0x9d495183','0x7ffcb923a29',43,
+		3,10000,
+	], 512 => [
+		'0xfa000000','0x7e000000',31,
+		125,64,
+		'0x83126e98','0xfdf3b645',32,
+		64,125,
+		'0xf4240000','0x1c0000',21,
+		15625,8,
+		'0x8637bd06','0x3ffef39085f',42,
+		8,15625,
+	], 1000 => [
+		'0x80000000','0x0',31,
+		1,1,
+		'0x80000000','0x0',31,
+		1,1,
+		'0xfa000000','0x0',22,
+		1000,1,
+		'0x83126e98','0x1ff7ced9168',41,
+		1,1000,
+	], 1024 => [
+		'0xfa000000','0xfe000000',32,
+		125,128,
+		'0x83126e98','0x7ef9db22',31,
+		128,125,
+		'0xf4240000','0x3c0000',22,
+		15625,16,
+		'0x8637bd06','0x1fff79c842f',41,
+		16,15625,
+	], 1200 => [
+		'0xd5555556','0xd5555555',32,
+		5,6,
+		'0x9999999a','0x66666666',31,
+		6,5,
+		'0xd0555556','0x2aaaaa',22,
+		2500,3,
+		'0x9d495183','0x1ffcb923a29',41,
+		3,2500,
+	]
+);
+
+$has_bigint = eval 'use Math::BigInt qw(bgcd); 1;';
+
+sub bint($)
+{
+	my($x) = @_;
+	return Math::BigInt->new($x);
+}
+
+#
+# Constants for division by reciprocal multiplication.
+# (bits, numerator, denominator)
+#
+sub fmul($$$)
+{
+	my ($b,$n,$d) = @_;
+
+	$n = bint($n);
+	$d = bint($d);
+
+	return scalar (($n << $b)+$d-bint(1))/$d;
+}
+
+sub fadj($$$)
+{
+	my($b,$n,$d) = @_;
+
+	$n = bint($n);
+	$d = bint($d);
+
+	$d = $d/bgcd($n, $d);
+	return scalar (($d-bint(1)) << $b)/$d;
+}
+
+sub fmuls($$$) {
+	my($b,$n,$d) = @_;
+	my($s,$m);
+	my($thres) = bint(1) << ($b-1);
+
+	$n = bint($n);
+	$d = bint($d);
+
+	for ($s = 0; 1; $s++) {
+		$m = fmul($s,$n,$d);
+		return $s if ($m >= $thres);
+	}
+	return 0;
+}
+
+# Generate a hex value if the result fits in 64 bits;
+# otherwise skip.
+sub bignum_hex($) {
+	my($x) = @_;
+	my $s = $x->as_hex();
+
+	return (length($s) > 18) ? undef : $s;
+}
+
+# Provides mul, adj, and shr factors for a specific
+# (bit, time, hz) combination
+sub muladj($$$) {
+	my($b, $t, $hz) = @_;
+	my $s = fmuls($b, $t, $hz);
+	my $m = fmul($s, $t, $hz);
+	my $a = fadj($s, $t, $hz);
+	return (bignum_hex($m), bignum_hex($a), $s);
+}
+
+# Provides numerator, denominator values
+sub numden($$) {
+	my($n, $d) = @_;
+	my $g = bgcd($n, $d);
+	return ($n/$g, $d/$g);
+}
+
+# All values for a specific (time, hz) combo
+sub conversions($$) {
+	my ($t, $hz) = @_;
+	my @val = ();
+
+	# HZ_TO_xx
+	push(@val, muladj(32, $t, $hz));
+	push(@val, numden($t, $hz));
+
+	# xx_TO_HZ
+	push(@val, muladj(32, $hz, $t));
+	push(@val, numden($hz, $t));
+
+	return @val;
+}
+
+sub compute_values($) {
+	my($hz) = @_;
+	my @val = ();
+	my $s, $m, $a, $g;
+
+	if (!$has_bigint) {
+		die "$0: HZ == $hz not canned and ".
+		    "Math::BigInt not available\n";
+	}
+
+	# MSEC conversions
+	push(@val, conversions(1000, $hz));
+
+	# USEC conversions
+	push(@val, conversions(1000000, $hz));
+
+	return @val;
+}
+
+sub outputval($$)
+{
+	my($name, $val) = @_;
+	my $csuf;
+
+	if (defined($val)) {
+	    if ($name !~ /SHR/) {
+		$val = "U64_C($val)";
+	    }
+	    printf "#define %-23s %s\n", $name.$csuf, $val.$csuf;
+	}
+}
+
+sub output($@)
+{
+	my($hz, @val) = @_;
+	my $pfx, $bit, $suf, $s, $m, $a;
+
+	print "/* Automatically generated by kernel/timeconst.pl */\n";
+	print "/* Conversion constants for HZ == $hz */\n";
+	print "\n";
+	print "#ifndef KERNEL_TIMECONST_H\n";
+	print "#define KERNEL_TIMECONST_H\n";
+	print "\n";
+
+	print "#include <linux/param.h>\n";
+	print "#include <linux/types.h>\n";
+
+	print "\n";
+	print "#if HZ != $hz\n";
+	print "#error \"kernel/timeconst.h has the wrong HZ value!\"\n";
+	print "#endif\n";
+	print "\n";
+
+	foreach $pfx ('HZ_TO_MSEC','MSEC_TO_HZ',
+		      'HZ_TO_USEC','USEC_TO_HZ') {
+		foreach $bit (32) {
+			foreach $suf ('MUL', 'ADJ', 'SHR') {
+				outputval("${pfx}_$suf$bit", shift(@val));
+			}
+		}
+		foreach $suf ('NUM', 'DEN') {
+			outputval("${pfx}_$suf", shift(@val));
+		}
+	}
+
+	print "\n";
+	print "#endif /* KERNEL_TIMECONST_H */\n";
+}
+
+# Pretty-print Perl values
+sub perlvals(@) {
+	my $v;
+	my @l = ();
+
+	foreach $v (@_) {
+		if (!defined($v)) {
+			push(@l, 'undef');
+		} elsif ($v =~ /^0x/) {
+			push(@l, "\'".$v."\'");
+		} else {
+			push(@l, $v.'');
+		}
+	}
+	return join(',', @l);
+}
+
+($hz) = @ARGV;
+
+# Use this to generate the %canned_values structure
+if ($hz eq '--can') {
+	shift(@ARGV);
+	@hzlist = sort {$a <=> $b} (@ARGV);
+
+	print "# Precomputed values for systems without Math::BigInt\n";
+	print "# Generated by:\n";
+	print "# timeconst.pl --can ", join(' ', @hzlist), "\n";
+	print "\%canned_values = (\n";
+	my $pf = "\t";
+	foreach $hz (@hzlist) {
+		my @values = compute_values($hz);
+		print "$pf$hz => [\n";
+		while (scalar(@values)) {
+			my $bit;
+			foreach $bit (32) {
+				my $m = shift(@values);
+				my $a = shift(@values);
+				my $s = shift(@values);
+				print "\t\t", perlvals($m,$a,$s), ",\n";
+			}
+			my $n = shift(@values);
+			my $d = shift(@values);
+			print "\t\t", perlvals($n,$d), ",\n";
+		}
+		print "\t]";
+		$pf = ', ';
+	}
+	print "\n);\n";
+} else {
+	$hz += 0;			# Force to number
+	if ($hz < 1) {
+		die "Usage: $0 HZ\n";
+	}
+
+	@val = @{$canned_values{$hz}};
+	if (!defined(@val)) {
+		@val = compute_values($hz);
+	}
+	output($hz, @val);
+}
+exit 0;