Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/scripts/get_abi.pl b/scripts/get_abi.pl
new file mode 100755
index 0000000..c738cb7
--- /dev/null
+++ b/scripts/get_abi.pl
@@ -0,0 +1,468 @@
+#!/usr/bin/perl
+# SPDX-License-Identifier: GPL-2.0
+
+use strict;
+use Pod::Usage;
+use Getopt::Long;
+use File::Find;
+use Fcntl ':mode';
+
+my $help;
+my $man;
+my $debug;
+my $prefix="Documentation/ABI";
+
+GetOptions(
+	"debug|d+" => \$debug,
+	"dir=s" => \$prefix,
+	'help|?' => \$help,
+	man => \$man
+) or pod2usage(2);
+
+pod2usage(1) if $help;
+pod2usage(-exitstatus => 0, -verbose => 2) if $man;
+
+pod2usage(2) if (scalar @ARGV < 1 || @ARGV > 2);
+
+my ($cmd, $arg) = @ARGV;
+
+pod2usage(2) if ($cmd ne "search" && $cmd ne "rest" && $cmd ne "validate");
+pod2usage(2) if ($cmd eq "search" && !$arg);
+
+require Data::Dumper if ($debug);
+
+my %data;
+
+#
+# Displays an error message, printing file name and line
+#
+sub parse_error($$$$) {
+	my ($file, $ln, $msg, $data) = @_;
+
+	print STDERR "file $file#$ln: $msg at\n\t$data";
+}
+
+#
+# Parse an ABI file, storing its contents at %data
+#
+sub parse_abi {
+	my $file = $File::Find::name;
+
+	my $mode = (stat($file))[2];
+	return if ($mode & S_IFDIR);
+	return if ($file =~ m,/README,);
+
+	my $name = $file;
+	$name =~ s,.*/,,;
+
+	my $nametag = "File $name";
+	$data{$nametag}->{what} = "File $name";
+	$data{$nametag}->{type} = "File";
+	$data{$nametag}->{file} = $name;
+	$data{$nametag}->{filepath} = $file;
+	$data{$nametag}->{is_file} = 1;
+
+	my $type = $file;
+	$type =~ s,.*/(.*)/.*,$1,;
+
+	my $what;
+	my $new_what;
+	my $tag;
+	my $ln;
+	my $xrefs;
+	my $space;
+	my @labels;
+	my $label;
+
+	print STDERR "Opening $file\n" if ($debug > 1);
+	open IN, $file;
+	while(<IN>) {
+		$ln++;
+		if (m/^(\S+)(:\s*)(.*)/i) {
+			my $new_tag = lc($1);
+			my $sep = $2;
+			my $content = $3;
+
+			if (!($new_tag =~ m/(what|where|date|kernelversion|contact|description|users)/)) {
+				if ($tag eq "description") {
+					# New "tag" is actually part of
+					# description. Don't consider it a tag
+					$new_tag = "";
+				} elsif ($tag ne "") {
+					parse_error($file, $ln, "tag '$tag' is invalid", $_);
+				}
+			}
+
+			# Invalid, but it is a common mistake
+			if ($new_tag eq "where") {
+				parse_error($file, $ln, "tag 'Where' is invalid. Should be 'What:' instead", $_);
+				$new_tag = "what";
+			}
+
+			if ($new_tag =~ m/what/) {
+				$space = "";
+				if ($tag =~ m/what/) {
+					$what .= ", " . $content;
+				} else {
+					parse_error($file, $ln, "What '$what' doesn't have a description", "") if ($what && !$data{$what}->{description});
+
+					$what = $content;
+					$label = $content;
+					$new_what = 1;
+				}
+				push @labels, [($content, $label)];
+				$tag = $new_tag;
+
+				push @{$data{$nametag}->{xrefs}}, [($content, $label)] if ($data{$nametag}->{what});
+				next;
+			}
+
+			if ($tag ne "" && $new_tag) {
+				$tag = $new_tag;
+
+				if ($new_what) {
+					@{$data{$what}->{label}} = @labels if ($data{$nametag}->{what});
+					@labels = ();
+					$label = "";
+					$new_what = 0;
+
+					$data{$what}->{type} = $type;
+					$data{$what}->{file} = $name;
+					$data{$what}->{filepath} = $file;
+					print STDERR "\twhat: $what\n" if ($debug > 1);
+				}
+
+				if (!$what) {
+					parse_error($file, $ln, "'What:' should come first:", $_);
+					next;
+				}
+				if ($tag eq "description") {
+					next if ($content =~ m/^\s*$/);
+					if ($content =~ m/^(\s*)(.*)/) {
+						my $new_content = $2;
+						$space = $new_tag . $sep . $1;
+						while ($space =~ s/\t+/' ' x (length($&) * 8 - length($`) % 8)/e) {}
+						$space =~ s/./ /g;
+						$data{$what}->{$tag} .= "$new_content\n";
+					}
+				} else {
+					$data{$what}->{$tag} = $content;
+				}
+				next;
+			}
+		}
+
+		# Store any contents before tags at the database
+		if (!$tag && $data{$nametag}->{what}) {
+			$data{$nametag}->{description} .= $_;
+			next;
+		}
+
+		if ($tag eq "description") {
+			if (!$data{$what}->{description}) {
+				next if (m/^\s*\n/);
+				if (m/^(\s*)(.*)/) {
+					$space = $1;
+					while ($space =~ s/\t+/' ' x (length($&) * 8 - length($`) % 8)/e) {}
+					$data{$what}->{$tag} .= "$2\n";
+				}
+			} else {
+				my $content = $_;
+				if (m/^\s*\n/) {
+					$data{$what}->{$tag} .= $content;
+					next;
+				}
+
+				while ($content =~ s/\t+/' ' x (length($&) * 8 - length($`) % 8)/e) {}
+				$space = "" if (!($content =~ s/^($space)//));
+
+				# Compress spaces with tabs
+				$content =~ s<^ {8}> <\t>;
+				$content =~ s<^ {1,7}\t> <\t>;
+				$content =~ s< {1,7}\t> <\t>;
+				$data{$what}->{$tag} .= $content;
+			}
+			next;
+		}
+		if (m/^\s*(.*)/) {
+			$data{$what}->{$tag} .= "\n$1";
+			$data{$what}->{$tag} =~ s/\n+$//;
+			next;
+		}
+
+		# Everything else is error
+		parse_error($file, $ln, "Unexpected line:", $_);
+	}
+	$data{$nametag}->{description} =~ s/^\n+//;
+	close IN;
+}
+
+#
+# Outputs the book on ReST format
+#
+
+my %labels;
+
+sub output_rest {
+	foreach my $what (sort {
+				($data{$a}->{type} eq "File") cmp ($data{$b}->{type} eq "File") ||
+				$a cmp $b
+			       } keys %data) {
+		my $type = $data{$what}->{type};
+		my $file = $data{$what}->{file};
+		my $filepath = $data{$what}->{filepath};
+
+		my $w = $what;
+		$w =~ s/([\(\)\_\-\*\=\^\~\\])/\\$1/g;
+
+
+		foreach my $p (@{$data{$what}->{label}}) {
+			my ($content, $label) = @{$p};
+			$label = "abi_" . $label . " ";
+			$label =~ tr/A-Z/a-z/;
+
+			# Convert special chars to "_"
+			$label =~s/([\x00-\x2f\x3a-\x40\x5b-\x60\x7b-\xff])/_/g;
+			$label =~ s,_+,_,g;
+			$label =~ s,_$,,;
+
+			# Avoid duplicated labels
+			while (defined($labels{$label})) {
+			    my @chars = ("A".."Z", "a".."z");
+			    $label .= $chars[rand @chars];
+			}
+			$labels{$label} = 1;
+
+			$data{$what}->{label} .= $label;
+
+			printf ".. _%s:\n\n", $label;
+
+			# only one label is enough
+			last;
+		}
+
+
+		$filepath =~ s,.*/(.*/.*),\1,;;
+		$filepath =~ s,[/\-],_,g;;
+		my $fileref = "abi_file_".$filepath;
+
+		if ($type eq "File") {
+			my $bar = $w;
+			$bar =~ s/./-/g;
+
+			print ".. _$fileref:\n\n";
+			print "$w\n$bar\n\n";
+		} else {
+			my @names = split /\s*,\s*/,$w;
+
+			my $len = 0;
+
+			foreach my $name (@names) {
+				$len = length($name) if (length($name) > $len);
+			}
+
+			print "What:\n\n";
+
+			print "+-" . "-" x $len . "-+\n";
+			foreach my $name (@names) {
+				printf "| %s", $name . " " x ($len - length($name)) . " |\n";
+				print "+-" . "-" x $len . "-+\n";
+			}
+			print "\n";
+		}
+
+		print "Defined on file :ref:`$file <$fileref>`\n\n" if ($type ne "File");
+
+		my $desc = $data{$what}->{description};
+		$desc =~ s/^\s+//;
+
+		# Remove title markups from the description, as they won't work
+		$desc =~ s/\n[\-\*\=\^\~]+\n/\n/g;
+
+		if (!($desc =~ /^\s*$/)) {
+			if ($desc =~ m/\:\n/ || $desc =~ m/\n[\t ]+/  || $desc =~ m/[\x00-\x08\x0b-\x1f\x7b-\xff]/) {
+				# put everything inside a code block
+				$desc =~ s/\n/\n /g;
+
+				print "::\n\n";
+				print " $desc\n\n";
+			} else {
+				# Escape any special chars from description
+				$desc =~s/([\x00-\x08\x0b-\x1f\x21-\x2a\x2d\x2f\x3c-\x40\x5c\x5e-\x60\x7b-\xff])/\\$1/g;
+
+				print "$desc\n\n";
+			}
+		} else {
+			print "DESCRIPTION MISSING for $what\n\n" if (!$data{$what}->{is_file});
+		}
+
+		if ($data{$what}->{xrefs}) {
+			printf "Has the following ABI:\n\n";
+
+			foreach my $p(@{$data{$what}->{xrefs}}) {
+				my ($content, $label) = @{$p};
+				$label = "abi_" . $label . " ";
+				$label =~ tr/A-Z/a-z/;
+
+				# Convert special chars to "_"
+				$label =~s/([\x00-\x2f\x3a-\x40\x5b-\x60\x7b-\xff])/_/g;
+				$label =~ s,_+,_,g;
+				$label =~ s,_$,,;
+
+				# Escape special chars from content
+				$content =~s/([\x00-\x1f\x21-\x2f\x3a-\x40\x7b-\xff])/\\$1/g;
+
+				print "- :ref:`$content <$label>`\n\n";
+			}
+		}
+	}
+}
+
+#
+# Searches for ABI symbols
+#
+sub search_symbols {
+	foreach my $what (sort keys %data) {
+		next if (!($what =~ m/($arg)/));
+
+		my $type = $data{$what}->{type};
+		next if ($type eq "File");
+
+		my $file = $data{$what}->{filepath};
+
+		my $bar = $what;
+		$bar =~ s/./-/g;
+
+		print "\n$what\n$bar\n\n";
+
+		my $kernelversion = $data{$what}->{kernelversion};
+		my $contact = $data{$what}->{contact};
+		my $users = $data{$what}->{users};
+		my $date = $data{$what}->{date};
+		my $desc = $data{$what}->{description};
+		$kernelversion =~ s/^\s+//;
+		$contact =~ s/^\s+//;
+		$users =~ s/^\s+//;
+		$users =~ s/\n//g;
+		$date =~ s/^\s+//;
+		$desc =~ s/^\s+//;
+
+		printf "Kernel version:\t\t%s\n", $kernelversion if ($kernelversion);
+		printf "Date:\t\t\t%s\n", $date if ($date);
+		printf "Contact:\t\t%s\n", $contact if ($contact);
+		printf "Users:\t\t\t%s\n", $users if ($users);
+		print "Defined on file:\t$file\n\n";
+		print "Description:\n\n$desc";
+	}
+}
+
+
+#
+# Parses all ABI files located at $prefix dir
+#
+find({wanted =>\&parse_abi, no_chdir => 1}, $prefix);
+
+print STDERR Data::Dumper->Dump([\%data], [qw(*data)]) if ($debug);
+
+#
+# Handles the command
+#
+if ($cmd eq "rest") {
+	output_rest;
+} elsif ($cmd eq "search") {
+	search_symbols;
+}
+
+
+__END__
+
+=head1 NAME
+
+abi_book.pl - parse the Linux ABI files and produce a ReST book.
+
+=head1 SYNOPSIS
+
+B<abi_book.pl> [--debug] [--man] [--help] [--dir=<dir>] <COMAND> [<ARGUMENT>]
+
+Where <COMMAND> can be:
+
+=over 8
+
+B<search> [SEARCH_REGEX] - search for [SEARCH_REGEX] inside ABI
+
+B<rest>                  - output the ABI in ReST markup language
+
+B<validate>              - validate the ABI contents
+
+=back
+
+=head1 OPTIONS
+
+=over 8
+
+=item B<--dir>
+
+Changes the location of the ABI search. By default, it uses
+the Documentation/ABI directory.
+
+=item B<--debug>
+
+Put the script in verbose mode, useful for debugging. Can be called multiple
+times, to increase verbosity.
+
+=item B<--help>
+
+Prints a brief help message and exits.
+
+=item B<--man>
+
+Prints the manual page and exits.
+
+=back
+
+=head1 DESCRIPTION
+
+Parse the Linux ABI files from ABI DIR (usually located at Documentation/ABI),
+allowing to search for ABI symbols or to produce a ReST book containing
+the Linux ABI documentation.
+
+=head1 EXAMPLES
+
+Search for all stable symbols with the word "usb":
+
+=over 8
+
+$ scripts/get_abi.pl search usb --dir Documentation/ABI/stable
+
+=back
+
+Search for all symbols that match the regex expression "usb.*cap":
+
+=over 8
+
+$ scripts/get_abi.pl search usb.*cap
+
+=back
+
+Output all obsoleted symbols in ReST format
+
+=over 8
+
+$ scripts/get_abi.pl rest --dir Documentation/ABI/obsolete
+
+=back
+
+=head1 BUGS
+
+Report bugs to Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
+
+=head1 COPYRIGHT
+
+Copyright (c) 2016-2019 by Mauro Carvalho Chehab <mchehab+samsung@kernel.org>.
+
+License GPLv2: GNU GPL version 2 <http://gnu.org/licenses/gpl.html>.
+
+This is free software: you are free to change and redistribute it.
+There is NO WARRANTY, to the extent permitted by law.
+
+=cut