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-rw-r--r--arch/tile/include/asm/checksum.h18
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/tile/include/asm/checksum.h b/arch/tile/include/asm/checksum.h
index a120766..b21a2fd 100644
--- a/arch/tile/include/asm/checksum.h
+++ b/arch/tile/include/asm/checksum.h
@@ -21,4 +21,22 @@
__wsum do_csum(const unsigned char *buff, int len);
#define do_csum do_csum
+/*
+ * Return the sum of all the 16-bit subwords in a long.
+ * This sums two subwords on a 32-bit machine, and four on 64 bits.
+ * The implementation does two vector adds to capture any overflow.
+ */
+static inline unsigned int csum_long(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;
+}
+
#endif /* _ASM_TILE_CHECKSUM_H */