cifs: add winucase_convert.pl to Documentation/ directory

Add the script used to generate the case-conversion tables to the
Documentation/ directory, in case we ever need to update or regenerate
these tables in the future.

Signed-off-by: Jeff Layton <jlayton@redhat.com>

diff --git a/Documentation/filesystems/cifs/winucase_convert.pl b/Documentation/filesystems/cifs/winucase_convert.pl
new file mode 100755 (executable)
index 0000000..322a9c8
--- /dev/null
+++ b/Documentation/filesystems/cifs/winucase_convert.pl
@@ -0,0 +1,62 @@
+#!/usr/bin/perl -w
+#
+# winucase_convert.pl -- convert "Windows 8 Upper Case Mapping Table.txt" to
+#                        a two-level set of C arrays.
+#
+#   Copyright 2013: Jeff Layton <jlayton@redhat.com>
+#
+#   This program is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation, either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+while(<>) {
+       next if (!/^0x(..)(..)\t0x(....)\t/);
+       $firstchar = hex($1);
+       $secondchar = hex($2);
+       $uppercase = hex($3);
+
+       $top[$firstchar][$secondchar] = $uppercase;
+}
+
+for ($i = 0; $i < 256; $i++) {
+       next if (!$top[$i]);
+
+       printf("static const wchar_t t2_%2.2x[256] = {", $i);
+       for ($j = 0; $j < 256; $j++) {
+               if (($j % 8) == 0) {
+                       print "\n\t";
+               } else {
+                       print " ";
+               }
+               printf("0x%4.4x,", $top[$i][$j] ? $top[$i][$j] : 0);
+       }
+       print "\n};\n\n";
+}
+
+printf("static const wchar_t *const toplevel[256] = {", $i);
+for ($i = 0; $i < 256; $i++) {
+       if (($i % 8) == 0) {
+               print "\n\t";
+       } elsif ($top[$i]) {
+               print " ";
+       } else {
+               print "  ";
+       }
+
+       if ($top[$i]) {
+               printf("t2_%2.2x,", $i);
+       } else {
+               print "NULL,";
+       }
+}
+print "\n};\n\n";