Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6

1 files changed, 36 insertions, 0 deletions

diff --git a/arch/tile/lib/strlen_32.c b/arch/tile/lib/strlen_32.c
new file mode 100644
index 000000000000..f26f88e11e4a
--- /dev/null
+++ b/arch/tile/lib/strlen_32.c
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   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, version 2.
+ *
+ *   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, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+
+size_t strlen(const char *s)
+{
+	/* Get an aligned pointer. */
+	const uintptr_t s_int = (uintptr_t) s;
+	const uint32_t *p = (const uint32_t *)(s_int & -4);
+
+	/* Read the first word, but force bytes before the string to be nonzero.
+	 * This expression works because we know shift counts are taken mod 32.
+	 */
+	uint32_t v = *p | ((1 << (s_int << 3)) - 1);
+
+	uint32_t bits;
+	while ((bits = __insn_seqb(v, 0)) == 0)
+		v = *++p;
+
+	return ((const char *)p) + (__insn_ctz(bits) >> 3) - s;
+}
+EXPORT_SYMBOL(strlen);