1 files changed, 29 insertions, 0 deletions

diff --git a/include/asm-cris/arch-v32/checksum.h b/include/asm-cris/arch-v32/checksum.h
new file mode 100644
index 000000000000..a1d6b2a6cc44
--- /dev/null
+++ b/include/asm-cris/arch-v32/checksum.h
@@ -0,0 +1,29 @@
+#ifndef _ASM_CRIS_ARCH_CHECKSUM_H
+#define _ASM_CRIS_ARCH_CHECKSUM_H
+
+/*
+ * Check values used in TCP/UDP headers.
+ *
+ * The gain of doing this in assembler instead of C, is that C doesn't
+ * generate carry-additions for the 32-bit components of the
+ * checksum. Which means it would be necessary to split all those into
+ * 16-bit components and then add.
+ */
+extern inline unsigned int
+csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr,
+                   unsigned short len, unsigned short proto, unsigned int sum)
+{
+        int res;
+
+        __asm__ __volatile__ ("add.d %2, %0\n\t"
+                              "addc %3, %0\n\t"
+                              "addc %4, %0\n\t"
+                              "addc 0, %0\n\t"
+                              : "=r" (res)
+                              : "0" (sum), "r" (daddr), "r" (saddr), \
+                              "r" ((ntohs(len) << 16) + (proto << 8)));
+
+        return res;
+}
+
+#endif /* _ASM_CRIS_ARCH_CHECKSUM_H */