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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-cris/arch-v10/checksum.h
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/asm-cris/arch-v10/checksum.h')
-rw-r--r--include/asm-cris/arch-v10/checksum.h29
1 files changed, 29 insertions, 0 deletions
diff --git a/include/asm-cris/arch-v10/checksum.h b/include/asm-cris/arch-v10/checksum.h
new file mode 100644
index 00000000000..fde1d00aaa9
--- /dev/null
+++ b/include/asm-cris/arch-v10/checksum.h
@@ -0,0 +1,29 @@
+#ifndef _CRIS_ARCH_CHECKSUM_H
+#define _CRIS_ARCH_CHECKSUM_H
+
+/* Checksum some values used in TCP/UDP headers.
+ *
+ * The gain by doing this in asm is that C will not generate carry-additions
+ * for the 32-bit components of the checksum, so otherwise we would have had
+ * to split all of those into 16-bit components, 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__ ("add.d %2, %0\n\t"
+ "ax\n\t"
+ "add.d %3, %0\n\t"
+ "ax\n\t"
+ "add.d %4, %0\n\t"
+ "ax\n\t"
+ "addq 0, %0\n"
+ : "=r" (res)
+ : "0" (sum), "r" (daddr), "r" (saddr), "r" ((ntohs(len) << 16) + (proto << 8)));
+
+ return res;
+}
+
+#endif