ARC: Checksum/byteorder/swab routines
TBD: do_csum still needs to be written in asm
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/arc/include/asm/checksum.h b/arch/arc/include/asm/checksum.h
new file mode 100644
index 0000000..1095729
--- /dev/null
+++ b/arch/arc/include/asm/checksum.h
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Joern Rennecke <joern.rennecke@embecosm.com>: Jan 2012
+ * -Insn Scheduling improvements to csum core routines.
+ * = csum_fold( ) largely derived from ARM version.
+ * = ip_fast_cum( ) to have module scheduling
+ * -gcc 4.4.x broke networking. Alias analysis needed to be primed.
+ * worked around by adding memory clobber to ip_fast_csum( )
+ *
+ * vineetg: May 2010
+ * -Rewrote ip_fast_cscum( ) and csum_fold( ) with fast inline asm
+ */
+
+#ifndef _ASM_ARC_CHECKSUM_H
+#define _ASM_ARC_CHECKSUM_H
+
+/*
+ * Fold a partial checksum
+ *
+ * The 2 swords comprising the 32bit sum are added, any carry to 16th bit
+ * added back and final sword result inverted.
+ */
+static inline __sum16 csum_fold(__wsum s)
+{
+ unsigned r = s << 16 | s >> 16; /* ror */
+ s = ~s;
+ s -= r;
+ return s >> 16;
+}
+
+/*
+ * This is a version of ip_compute_csum() optimized for IP headers,
+ * which always checksum on 4 octet boundaries.
+ */
+static inline __sum16
+ip_fast_csum(const void *iph, unsigned int ihl)
+{
+ const void *ptr = iph;
+ unsigned int tmp, tmp2, sum;
+
+ __asm__(
+ " ld.ab %0, [%3, 4] \n"
+ " ld.ab %2, [%3, 4] \n"
+ " sub %1, %4, 2 \n"
+ " lsr.f lp_count, %1, 1 \n"
+ " bcc 0f \n"
+ " add.f %0, %0, %2 \n"
+ " ld.ab %2, [%3, 4] \n"
+ "0: lp 1f \n"
+ " ld.ab %1, [%3, 4] \n"
+ " adc.f %0, %0, %2 \n"
+ " ld.ab %2, [%3, 4] \n"
+ " adc.f %0, %0, %1 \n"
+ "1: adc.f %0, %0, %2 \n"
+ " add.cs %0,%0,1 \n"
+ : "=&r"(sum), "=r"(tmp), "=&r"(tmp2), "+&r" (ptr)
+ : "r"(ihl)
+ : "cc", "lp_count", "memory");
+
+ return csum_fold(sum);
+}
+
+/*
+ * TCP pseudo Header is 12 bytes:
+ * SA [4], DA [4], zeroes [1], Proto[1], TCP Seg(hdr+data) Len [2]
+ */
+static inline __wsum
+csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
+ unsigned short proto, __wsum sum)
+{
+ __asm__ __volatile__(
+ " add.f %0, %0, %1 \n"
+ " adc.f %0, %0, %2 \n"
+ " adc.f %0, %0, %3 \n"
+ " adc.f %0, %0, %4 \n"
+ " adc %0, %0, 0 \n"
+ : "+&r"(sum)
+ : "r"(saddr), "r"(daddr),
+#ifdef CONFIG_CPU_BIG_ENDIAN
+ "r"(len),
+#else
+ "r"(len << 8),
+#endif
+ "r"(htons(proto))
+ : "cc");
+
+ return sum;
+}
+
+#define csum_fold csum_fold
+#define ip_fast_csum ip_fast_csum
+#define csum_tcpudp_nofold csum_tcpudp_nofold
+
+#include <asm-generic/checksum.h>
+
+#endif /* _ASM_ARC_CHECKSUM_H */