#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 unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum) { /* * Experiments with ethernet and slip connections show that buf * is aligned on either a 2-byte or 4-byte boundary. */ #ifndef __s390x__ register_pair rp; rp.subreg.even = (unsigned long) buff; rp.subreg.odd = (unsigned long) len; __asm__ __volatile__ ( "0: cksm %0,%1\n" /* do checksum on longs */ " jo 0b\n" : "+&d" (sum), "+&a" (rp) : : "cc", "memory" ); #else /* __s390x__ */ __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", "memory", "2", "3" ); #endif /* __s390x__ */ return sum; } /* * csum_partial as an inline function */ static inline unsigned int csum_partial_inline(const unsigned char * buff, int len, unsigned int sum) { #ifndef __s390x__ register_pair rp; rp.subreg.even = (unsigned long) buff; rp.subreg.odd = (unsigned long) len; __asm__ __volatile__ ( "0: cksm %0,%1\n" /* do checksum on longs */ " jo 0b\n" : "+&d" (sum), "+&a" (rp) : : "cc", "memory" ); #else /* __s390x__ */ __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", "memory", "2", "3" ); #endif /* __s390x__ */ 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 unsigned int csum_partial_copy_from_user(const char __user *src, char *dst, int len, unsigned int 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 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 */ static inline unsigned short csum_fold(unsigned int 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, 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"); #endif /* __s390x__ */ return ((unsigned short) ~sum); } /* * This is a version of ip_compute_csum() optimized for IP headers, * which always checksum on 4 octet boundaries. * */ static inline unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl) { unsigned long sum; #ifndef __s390x__ register_pair rp; rp.subreg.even = (unsigned long) iph; rp.subreg.odd = (unsigned long) ihl*4; __asm__ __volatile__ ( " sr %0,%0\n" /* set sum to zero */ "0: cksm %0,%1\n" /* do checksum on longs */ " jo 0b\n" : "=&d" (sum), "+&a" (rp) : : "cc", "memory" ); #else /* __s390x__ */ __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", "memory", "2", "3" ); #endif /* __s390x__ */ return csum_fold(sum); } /* * computes the checksum of the TCP/UDP pseudo-header * returns a 32-bit checksum */ static inline unsigned int csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len, unsigned short proto, unsigned int sum) { #ifndef __s390x__ __asm__ __volatile__ ( " alr %0,%1\n" /* sum += saddr */ " brc 12,0f\n" " ahi %0,1\n" /* add carry */ "0:" : "+&d" (sum) : "d" (saddr) : "cc" ); __asm__ __volatile__ ( " alr %0,%1\n" /* sum += daddr */ " brc 12,1f\n" " ahi %0,1\n" /* add carry */ "1:" : "+&d" (sum) : "d" (daddr) : "cc" ); __asm__ __volatile__ ( " alr %0,%1\n" /* sum += (len<<16) + (proto<<8) */ " brc 12,2f\n" " ahi %0,1\n" /* add carry */ "2:" : "+&d" (sum) : "d" (((unsigned int) len<<16) + (unsigned int) proto) : "cc" ); #else /* __s390x__ */ __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" ); #endif /* __s390x__ */ return sum; } /* * computes the checksum of the TCP/UDP pseudo-header * returns a 16-bit checksum, already complemented */ static 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 */ static inline unsigned short ip_compute_csum(unsigned char * buff, int len) { return csum_fold(csum_partial(buff, len, 0)); } #endif /* _S390_CHECKSUM_H */