1 files changed, 166 insertions, 0 deletions

diff --git a/arch/s390/include/asm/checksum.h b/arch/s390/include/asm/checksum.h
new file mode 100644
index 000000000000..d5a8e7c1477c
--- /dev/null
+++ b/arch/s390/include/asm/checksum.h
@@ -0,0 +1,166 @@
+#ifndef _S390_CHECKSUM_H
+#define _S390_CHECKSUM_H
+
+/*
+ *  include/asm-s390/checksum.h
+ *    S390 fast network checksum routines
+ *    see also arch/S390/lib/checksum.c
+ *
+ *  S390 version
+ *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Ulrich Hild        (first version)
+ *               Martin Schwidefsky (heavily optimized CKSM version)
+ *               D.J. Barrow        (third attempt) 
+ */
+
+#include <asm/uaccess.h>
+
+/*
+ * computes the checksum of a memory block at buff, length len,
+ * and adds in "sum" (32-bit)
+ *
+ * returns a 32-bit number suitable for feeding into itself
+ * or csum_tcpudp_magic
+ *
+ * this function must be called with even lengths, except
+ * for the last fragment, which may be odd
+ *
+ * it's best to have buff aligned on a 32-bit boundary
+ */
+static inline __wsum
+csum_partial(const void *buff, int len, __wsum sum)
+{
+        register unsigned long reg2 asm("2") = (unsigned long) buff;
+        register unsigned long reg3 asm("3") = (unsigned long) len;
+
+        asm volatile(
+                "0:     cksm    %0,%1\n"        /* do checksum on longs */
+                "       jo      0b\n"
+                : "+d" (sum), "+d" (reg2), "+d" (reg3) : : "cc", "memory");
+        return sum;
+}
+
+/*
+ * the same as csum_partial_copy, but copies from user space.
+ *
+ * here even more important to align src and dst on a 32-bit (or even
+ * better 64-bit) boundary
+ *
+ * Copy from userspace and compute checksum.  If we catch an exception
+ * then zero the rest of the buffer.
+ */
+static inline __wsum
+csum_partial_copy_from_user(const void __user *src, void *dst,
+                                          int len, __wsum sum,
+                                          int *err_ptr)
+{
+        int missing;
+
+        missing = copy_from_user(dst, src, len);
+        if (missing) {
+                memset(dst + len - missing, 0, missing);
+                *err_ptr = -EFAULT;
+        }
+                
+        return csum_partial(dst, len, sum);
+}
+
+
+static inline __wsum
+csum_partial_copy_nocheck (const void *src, void *dst, int len, __wsum sum)
+{
+        memcpy(dst,src,len);
+        return csum_partial(dst, len, sum);
+}
+
+/*
+ *      Fold a partial checksum without adding pseudo headers
+ */
+static inline __sum16 csum_fold(__wsum sum)
+{
+#ifndef __s390x__
+        register_pair rp;
+
+        asm volatile(
+                "       slr     %N1,%N1\n"      /* %0 = H L */
+                "       lr      %1,%0\n"        /* %0 = H L, %1 = H L 0 0 */
+                "       srdl    %1,16\n"        /* %0 = H L, %1 = 0 H L 0 */
+                "       alr     %1,%N1\n"       /* %0 = H L, %1 = L H L 0 */
+                "       alr     %0,%1\n"        /* %0 = H+L+C L+H */
+                "       srl     %0,16\n"        /* %0 = H+L+C */
+                : "+&d" (sum), "=d" (rp) : : "cc");
+#else /* __s390x__ */
+        asm volatile(
+                "       sr      3,3\n"          /* %0 = H*65536 + L */
+                "       lr      2,%0\n"         /* %0 = H L, 2/3 = H L / 0 0 */
+                "       srdl    2,16\n"         /* %0 = H L, 2/3 = 0 H / L 0 */
+                "       alr     2,3\n"          /* %0 = H L, 2/3 = L H / L 0 */
+                "       alr     %0,2\n"         /* %0 = H+L+C L+H */
+                "       srl     %0,16\n"        /* %0 = H+L+C */
+                : "+&d" (sum) : : "cc", "2", "3");
+#endif /* __s390x__ */
+        return (__force __sum16) ~sum;
+}
+
+/*
+ *      This is a version of ip_compute_csum() optimized for IP headers,
+ *      which always checksum on 4 octet boundaries.
+ *
+ */
+static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
+{
+        return csum_fold(csum_partial(iph, ihl*4, 0));
+}
+
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 32-bit checksum
+ */
+static inline __wsum
+csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
+                   unsigned short len, unsigned short proto,
+                   __wsum sum)
+{
+        __u32 csum = (__force __u32)sum;
+
+        csum += (__force __u32)saddr;
+        if (csum < (__force __u32)saddr)
+                csum++;
+
+        csum += (__force __u32)daddr;
+        if (csum < (__force __u32)daddr)
+                csum++;
+
+        csum += len + proto;
+        if (csum < len + proto)
+                csum++;
+
+        return (__force __wsum)csum;
+}
+
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+
+static inline __sum16
+csum_tcpudp_magic(__be32 saddr, __be32 daddr,
+                  unsigned short len, unsigned short proto,
+                  __wsum sum)
+{
+        return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
+}
+
+/*
+ * this routine is used for miscellaneous IP-like checksums, mainly
+ * in icmp.c
+ */
+
+static inline __sum16 ip_compute_csum(const void *buff, int len)
+{
+        return csum_fold(csum_partial(buff, len, 0));
+}
+
+#endif /* _S390_CHECKSUM_H */
+
+