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authorDave Airlie <airlied@starflyer.(none)>2005-07-30 14:37:43 +1000
committerDave Airlie <airlied@linux.ie>2005-07-30 14:37:43 +1000
commitbdf242eeb0f69567fe43eba93889d80ecacbfe94 (patch)
treedc402eeeb75fd51e92b4f4a63712c6e64ac4c2fb /include/asm-cris/arch-v32/checksum.h
parent836cf0465c422ee6d654060edd7c620d9cf0c09c (diff)
parentb0825488a642cadcf39709961dde61440cb0731c (diff)
downloadblackbird-op-linux-bdf242eeb0f69567fe43eba93889d80ecacbfe94.tar.gz
blackbird-op-linux-bdf242eeb0f69567fe43eba93889d80ecacbfe94.zip
Merge ../linux-2.6/
Diffstat (limited to 'include/asm-cris/arch-v32/checksum.h')
-rw-r--r--include/asm-cris/arch-v32/checksum.h29
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 */
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