lib/checksum.c: make do_csum optional

Mike Frysinger suggested that do_csum should be optional so that an architecture can use the generic checksum code but still provide an optimized fast-path for the most critical function. This can mean an implementation using inline assembly, or in case of Alpha one using 64-bit arithmetic in C. Cc: Mike Frysinger <[email protected]> Signed-off-by: Arnd Bergmann <[email protected]>
chewitt · Nov 3, 2009 · 20c1f64 · 20c1f64
1 parent c44ba9f
commit 20c1f64
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/lib/checksum.c b/lib/checksum.c
@@ -37,6 +37,7 @@
 
 #include <asm/byteorder.h>
 
+#ifndef do_csum
 static inline unsigned short from32to16(unsigned int x)
 {
 	/* add up 16-bit and 16-bit for 16+c bit */
@@ -102,6 +103,7 @@ static unsigned int do_csum(const unsigned char *buff, int len)
 out:
 	return result;
 }
+#endif
 
 /*
  *	This is a version of ip_compute_csum() optimized for IP headers,