xtensa: Fix checksum header file
We need to add a "memory" dependency (barrier) in assembly macros
that access (read or write) memory. Otherwise, the compiler might
ill-optimize the order of memory accesses.
Signed-off-by: Chris Zankel <chris@zankel.net>
diff --git a/arch/xtensa/include/asm/checksum.h b/arch/xtensa/include/asm/checksum.h
index f84d3f0..e4d831a 100644
--- a/arch/xtensa/include/asm/checksum.h
+++ b/arch/xtensa/include/asm/checksum.h
@@ -113,7 +113,8 @@
are modified, we must also specify them as outputs, or gcc
will assume they contain their original values. */
: "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (tmp), "=&r" (endaddr)
- : "1" (iph), "2" (ihl));
+ : "1" (iph), "2" (ihl)
+ : "memory");
return csum_fold(sum);
}
@@ -227,7 +228,8 @@
"1:\t"
: "=r" (sum), "=&r" (__dummy)
: "r" (saddr), "r" (daddr),
- "r" (htonl(len)), "r" (htonl(proto)), "0" (sum));
+ "r" (htonl(len)), "r" (htonl(proto)), "0" (sum)
+ : "memory");
return csum_fold(sum);
}