arch/tile: core support for Tilera 32-bit chips.

This change is the core kernel support for TILEPro and TILE64 chips.
No driver support (except the console driver) is included yet.

This includes the relevant Linux headers in asm/; the low-level
low-level "Tile architecture" headers in arch/, which are
shared with the hypervisor, etc., and are build-system agnostic;
and the relevant hypervisor headers in hv/.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Paul Mundt <lethal@linux-sh.org>

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 0000000..e4bab5b
--- /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;
+}