summaryrefslogtreecommitdiffstats
path: root/include/asm-s390x/checksum.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-s390x/checksum.h')
-rw-r--r--include/asm-s390x/checksum.h188
1 files changed, 188 insertions, 0 deletions
diff --git a/include/asm-s390x/checksum.h b/include/asm-s390x/checksum.h
new file mode 100644
index 000000000..bb825c546
--- /dev/null
+++ b/include/asm-s390x/checksum.h
@@ -0,0 +1,188 @@
+#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
+ */
+unsigned int
+csum_partial(const unsigned char * buff, int len, unsigned int sum);
+
+/*
+ * csum_partial as an inline function
+ */
+extern inline unsigned int
+csum_partial_inline(const unsigned char * buff, int len, unsigned int sum)
+{
+ __asm__ __volatile__ (
+ " lgr 2,%1\n" /* address in gpr 2 */
+ " lgfr 3,%2\n" /* length in gpr 3 */
+ "0: cksm %0,2\n" /* do checksum on longs */
+ " jo 0b\n"
+ : "+&d" (sum)
+ : "d" (buff), "d" (len)
+ : "cc", "2", "3" );
+ return sum;
+}
+
+/*
+ * the same as csum_partial, but copies from src while it
+ * checksums
+ *
+ * here even more important to align src and dst on a 32-bit (or even
+ * better 64-bit) boundary
+ */
+
+extern inline unsigned int
+csum_partial_copy(const char *src, char *dst, int len,unsigned int sum)
+{
+ memcpy(dst,src,len);
+ return csum_partial_inline(dst, len, 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
+ */
+
+extern inline unsigned int
+csum_partial_copy_from_user(const char *src, char *dst,
+ int len, unsigned int sum, int *errp)
+{
+ if (copy_from_user(dst, src, len)) {
+ *errp = -EFAULT;
+ memset(dst, 0, len);
+ return sum;
+ }
+ return csum_partial_inline(dst, len, sum);
+}
+
+extern inline unsigned int
+csum_partial_copy_nocheck (const char *src, char *dst, int len, unsigned int sum)
+{
+ memcpy(dst,src,len);
+ return csum_partial_inline(dst, len, sum);
+}
+
+/*
+ * Fold a partial checksum without adding pseudo headers
+ */
+extern inline unsigned short
+csum_fold(unsigned int sum)
+{
+ __asm__ __volatile__ (
+ " sr 3,3\n" /* %0 = H*65536 + L */
+ " lr 2,%0\n" /* %0 = H L, R2/R3 = H L / 0 0 */
+ " srdl 2,16\n" /* %0 = H L, R2/R3 = 0 H / L 0 */
+ " alr 2,3\n" /* %0 = H L, R2/R3 = 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");
+ return ((unsigned short) ~sum);
+}
+
+/*
+ * This is a version of ip_compute_csum() optimized for IP headers,
+ * which always checksum on 4 octet boundaries.
+ *
+ */
+extern inline unsigned short
+ip_fast_csum(unsigned char *iph, unsigned int ihl)
+{
+ unsigned long sum;
+
+ __asm__ __volatile__ (
+ " slgr %0,%0\n" /* set sum to zero */
+ " lgr 2,%1\n" /* address in gpr 2 */
+ " lgfr 3,%2\n" /* length in gpr 3 */
+ "0: cksm %0,2\n" /* do checksum on ints */
+ " jo 0b\n"
+ : "=&d" (sum)
+ : "d" (iph), "d" (ihl*4)
+ : "cc", "2", "3" );
+ return csum_fold(sum);
+}
+
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 32-bit checksum
+ */
+extern inline unsigned int
+csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr,
+ unsigned short len, unsigned short proto,
+ unsigned int sum)
+{
+ __asm__ __volatile__ (
+ " lgfr %0,%0\n"
+ " algr %0,%1\n" /* sum += saddr */
+ " brc 12,0f\n"
+ " aghi %0,1\n" /* add carry */
+ "0: algr %0,%2\n" /* sum += daddr */
+ " brc 12,1f\n"
+ " aghi %0,1\n" /* add carry */
+ "1: algfr %0,%3\n" /* sum += (len<<16) + proto */
+ " brc 12,2f\n"
+ " aghi %0,1\n" /* add carry */
+ "2: srlg 0,%0,32\n"
+ " alr %0,0\n" /* fold to 32 bits */
+ " brc 12,3f\n"
+ " ahi %0,1\n" /* add carry */
+ "3: llgfr %0,%0"
+ : "+&d" (sum)
+ : "d" (saddr), "d" (daddr),
+ "d" (((unsigned int) len<<16) + (unsigned int) proto)
+ : "cc", "0" );
+ return sum;
+}
+
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+
+extern inline unsigned short int
+csum_tcpudp_magic(unsigned long saddr, unsigned long daddr,
+ unsigned short len, unsigned short proto,
+ unsigned int 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
+ */
+
+extern inline unsigned short
+ip_compute_csum(unsigned char * buff, int len)
+{
+ return csum_fold(csum_partial_inline(buff, len, 0));
+}
+
+#endif /* _S390_CHECKSUM_H */
+
+