Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / tile / lib / strlen_32.c

diff --git a/kernel/arch/tile/lib/strlen_32.c b/kernel/arch/tile/lib/strlen_32.c
new file mode 100644 (file)
index 0000000..f26f88e
--- /dev/null
+++ b/kernel/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);