1 files changed, 102 insertions, 0 deletions

diff --git a/arch/tile/lib/checksum.c b/arch/tile/lib/checksum.c
new file mode 100644
index 000000000000..e4bab5bd3f31
--- /dev/null
+++ b/arch/tile/lib/checksum.c
@@ -0,0 +1,102 @@
+/*
+ * 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.
+ * Support code for the main lib/checksum.c.
+ */
+
+#include <net/checksum.h>
+#include <linux/module.h>
+
+static inline unsigned int longto16(unsigned long x)
+{
+        unsigned long ret;
+#ifdef __tilegx__
+        ret = __insn_v2sadu(x, 0);
+        ret = __insn_v2sadu(ret, 0);
+#else
+        ret = __insn_sadh_u(x, 0);
+        ret = __insn_sadh_u(ret, 0);
+#endif
+        return ret;
+}
+
+__wsum do_csum(const unsigned char *buff, int len)
+{
+        int odd, count;
+        unsigned long result = 0;
+
+        if (len <= 0)
+                goto out;
+        odd = 1 & (unsigned long) buff;
+        if (odd) {
+                result = (*buff << 8);
+                len--;
+                buff++;
+        }
+        count = len >> 1;               /* nr of 16-bit words.. */
+        if (count) {
+                if (2 & (unsigned long) buff) {
+                        result += *(const unsigned short *)buff;
+                        count--;
+                        len -= 2;
+                        buff += 2;
+                }
+                count >>= 1;            /* nr of 32-bit words.. */
+                if (count) {
+#ifdef __tilegx__
+                        if (4 & (unsigned long) buff) {
+                                unsigned int w = *(const unsigned int *)buff;
+                                result = __insn_v2sadau(result, w, 0);
+                                count--;
+                                len -= 4;
+                                buff += 4;
+                        }
+                        count >>= 1;            /* nr of 64-bit words.. */
+#endif
+
+                        /*
+                         * This algorithm could wrap around for very
+                         * large buffers, but those should be impossible.
+                         */
+                        BUG_ON(count >= 65530);
+
+                        while (count) {
+                                unsigned long w = *(const unsigned long *)buff;
+                                count--;
+                                buff += sizeof(w);
+#ifdef __tilegx__
+                                result = __insn_v2sadau(result, w, 0);
+#else
+                                result = __insn_sadah_u(result, w, 0);
+#endif
+                        }
+#ifdef __tilegx__
+                        if (len & 4) {
+                                unsigned int w = *(const unsigned int *)buff;
+                                result = __insn_v2sadau(result, w, 0);
+                                buff += 4;
+                        }
+#endif
+                }
+                if (len & 2) {
+                        result += *(const unsigned short *) buff;
+                        buff += 2;
+                }
+        }
+        if (len & 1)
+                result += *buff;
+        result = longto16(result);
+        if (odd)
+                result = swab16(result);
+out:
+        return result;
+}