/* * include/asm-xtensa/checksum.h * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 2001 - 2005 Tensilica Inc. */ #ifndef _XTENSA_CHECKSUM_H #define _XTENSA_CHECKSUM_H #include <linux/config.h> #include <linux/in6.h> #include <xtensa/config/core.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 */ asmlinkage unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum); /* * the same as csum_partial, but copies from src while it * checksums, and handles user-space pointer exceptions correctly, when needed. * * here even more important to align src and dst on a 32-bit (or even * better 64-bit) boundary */ asmlinkage unsigned int csum_partial_copy_generic( const char *src, char *dst, int len, int sum, int *src_err_ptr, int *dst_err_ptr); /* * Note: when you get a NULL pointer exception here this means someone * passed in an incorrect kernel address to one of these functions. * * If you use these functions directly please don't forget the * verify_area(). */ extern __inline__ unsigned int csum_partial_copy_nocheck ( const char *src, char *dst, int len, int sum) { return csum_partial_copy_generic ( src, dst, len, sum, NULL, NULL); } extern __inline__ unsigned int csum_partial_copy_from_user ( const char *src, char *dst, int len, int sum, int *err_ptr) { return csum_partial_copy_generic ( src, dst, len, sum, err_ptr, NULL); } /* * These are the old (and unsafe) way of doing checksums, a warning message will be * printed if they are used and an exeption occurs. * * these functions should go away after some time. */ #define csum_partial_copy_fromuser csum_partial_copy unsigned int csum_partial_copy( const char *src, char *dst, int len, int sum); /* * Fold a partial checksum */ static __inline__ unsigned int csum_fold(unsigned int sum) { unsigned int __dummy; __asm__("extui %1, %0, 16, 16\n\t" "extui %0 ,%0, 0, 16\n\t" "add %0, %0, %1\n\t" "slli %1, %0, 16\n\t" "add %0, %0, %1\n\t" "extui %0, %0, 16, 16\n\t" "neg %0, %0\n\t" "addi %0, %0, -1\n\t" "extui %0, %0, 0, 16\n\t" : "=r" (sum), "=&r" (__dummy) : "0" (sum)); return 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 int sum, tmp, endaddr; __asm__ __volatile__( "sub %0, %0, %0\n\t" #if XCHAL_HAVE_LOOPS "loopgtz %2, 2f\n\t" #else "beqz %2, 2f\n\t" "slli %4, %2, 2\n\t" "add %4, %4, %1\n\t" "0:\t" #endif "l32i %3, %1, 0\n\t" "add %0, %0, %3\n\t" "bgeu %0, %3, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "addi %1, %1, 4\n\t" #if !XCHAL_HAVE_LOOPS "blt %1, %4, 0b\n\t" #endif "2:\t" /* Since the input registers which are loaded with iph and ihl 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)); return csum_fold(sum); } static __inline__ unsigned long csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len, unsigned short proto, unsigned int sum) { #ifdef __XTENSA_EL__ unsigned long len_proto = (ntohs(len)<<16)+proto*256; #elif defined(__XTENSA_EB__) unsigned long len_proto = (proto<<16)+len; #else # error processor byte order undefined! #endif __asm__("add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "add %0, %0, %2\n\t" "bgeu %0, %2, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "add %0, %0, %3\n\t" "bgeu %0, %3, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" : "=r" (sum), "=r" (len_proto) : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum)); 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)); } #define _HAVE_ARCH_IPV6_CSUM static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, __u32 len, unsigned short proto, unsigned int sum) { unsigned int __dummy; __asm__("l32i %1, %2, 0\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "l32i %1, %2, 4\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "l32i %1, %2, 8\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "l32i %1, %2, 12\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "l32i %1, %3, 0\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "l32i %1, %3, 4\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "l32i %1, %3, 8\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "l32i %1, %3, 12\n\t" "add %0, %0, %1\n\t" "bgeu %0, %1, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "add %0, %0, %4\n\t" "bgeu %0, %4, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" "add %0, %0, %5\n\t" "bgeu %0, %5, 1f\n\t" "addi %0, %0, 1\n\t" "1:\t" : "=r" (sum), "=&r" (__dummy) : "r" (saddr), "r" (daddr), "r" (htonl(len)), "r" (htonl(proto)), "0" (sum)); return csum_fold(sum); } /* * Copy and checksum to user */ #define HAVE_CSUM_COPY_USER static __inline__ unsigned int csum_and_copy_to_user (const char *src, char *dst, int len, int sum, int *err_ptr) { if (access_ok(VERIFY_WRITE, dst, len)) return csum_partial_copy_generic(src, dst, len, sum, NULL, err_ptr); if (len) *err_ptr = -EFAULT; return -1; /* invalid checksum */ } #endif