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Diffstat (limited to 'include/asm-mips/checksum.h')
| -rw-r--r-- | include/asm-mips/checksum.h | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/include/asm-mips/checksum.h b/include/asm-mips/checksum.h new file mode 100644 index 0000000..c25cc92 --- /dev/null +++ b/include/asm-mips/checksum.h @@ -0,0 +1,253 @@ +/* + * 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) 1995, 96, 97, 98, 99, 2001 by Ralf Baechle + * Copyright (C) 1999 Silicon Graphics, Inc. + * Copyright (C) 2001 Thiemo Seufer. + * Copyright (C) 2002 Maciej W. Rozycki + */ +#ifndef _ASM_CHECKSUM_H +#define _ASM_CHECKSUM_H + +#include <linux/config.h> +#include <linux/in6.h> + +#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); + +/* + * this is a new version of the above that records errors it finds in *errp, + * but continues and zeros the rest of the buffer. + */ +unsigned int csum_partial_copy_from_user(const unsigned char *src, unsigned char *dst, int len, + unsigned int sum, int *errp); + +/* + * Copy and checksum to user + */ +#define HAVE_CSUM_COPY_USER +static inline unsigned int csum_and_copy_to_user (const unsigned char *src, + unsigned char __user *dst, + int len, int sum, + int *err_ptr) +{ + might_sleep(); + sum = csum_partial(src, len, sum); + + if (copy_to_user(dst, src, len)) { + *err_ptr = -EFAULT; + return -1; + } + + return sum; +} + +/* + * the same as csum_partial, but copies from user space (but on MIPS + * we have just one address space, so this is identical to the above) + */ +unsigned int csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst, + int len, unsigned int sum); + +/* + * Fold a partial checksum without adding pseudo headers + */ +static inline unsigned short int csum_fold(unsigned int sum) +{ + __asm__( + ".set\tnoat\t\t\t# csum_fold\n\t" + "sll\t$1,%0,16\n\t" + "addu\t%0,$1\n\t" + "sltu\t$1,%0,$1\n\t" + "srl\t%0,%0,16\n\t" + "addu\t%0,$1\n\t" + "xori\t%0,0xffff\n\t" + ".set\tat" + : "=r" (sum) + : "0" (sum)); + + return sum; +} + +/* + * This is a version of ip_compute_csum() optimized for IP headers, + * which always checksum on 4 octet boundaries. + * + * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by + * Arnt Gulbrandsen. + */ +static inline unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl) +{ + unsigned int *word = (unsigned int *) iph; + unsigned int *stop = word + ihl; + unsigned int csum; + int carry; + + csum = word[0]; + csum += word[1]; + carry = (csum < word[1]); + csum += carry; + + csum += word[2]; + carry = (csum < word[2]); + csum += carry; + + csum += word[3]; + carry = (csum < word[3]); + csum += carry; + + word += 4; + do { + csum += *word; + carry = (csum < *word); + csum += carry; + word++; + } while (word != stop); + + return csum_fold(csum); +} + +static inline unsigned int csum_tcpudp_nofold(unsigned long saddr, + unsigned long daddr, unsigned short len, unsigned short proto, + unsigned int sum) +{ + __asm__( + ".set\tnoat\t\t\t# csum_tcpudp_nofold\n\t" +#ifdef CONFIG_MIPS32 + "addu\t%0, %2\n\t" + "sltu\t$1, %0, %2\n\t" + "addu\t%0, $1\n\t" + + "addu\t%0, %3\n\t" + "sltu\t$1, %0, %3\n\t" + "addu\t%0, $1\n\t" + + "addu\t%0, %4\n\t" + "sltu\t$1, %0, %4\n\t" + "addu\t%0, $1\n\t" +#endif +#ifdef CONFIG_MIPS64 + "daddu\t%0, %2\n\t" + "daddu\t%0, %3\n\t" + "daddu\t%0, %4\n\t" + "dsll32\t$1, %0, 0\n\t" + "daddu\t%0, $1\n\t" + "dsrl32\t%0, %0, 0\n\t" +#endif + ".set\tat" + : "=r" (sum) + : "0" (daddr), "r"(saddr), +#ifdef __MIPSEL__ + "r" (((unsigned long)htons(len)<<16) + proto*256), +#else + "r" (((unsigned long)(proto)<<16) + len), +#endif + "r" (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) +{ + __asm__( + ".set\tpush\t\t\t# csum_ipv6_magic\n\t" + ".set\tnoreorder\n\t" + ".set\tnoat\n\t" + "addu\t%0, %5\t\t\t# proto (long in network byte order)\n\t" + "sltu\t$1, %0, %5\n\t" + "addu\t%0, $1\n\t" + + "addu\t%0, %6\t\t\t# csum\n\t" + "sltu\t$1, %0, %6\n\t" + "lw\t%1, 0(%2)\t\t\t# four words source address\n\t" + "addu\t%0, $1\n\t" + "addu\t%0, %1\n\t" + "sltu\t$1, %0, %1\n\t" + + "lw\t%1, 4(%2)\n\t" + "addu\t%0, $1\n\t" + "addu\t%0, %1\n\t" + "sltu\t$1, %0, %1\n\t" + + "lw\t%1, 8(%2)\n\t" + "addu\t%0, $1\n\t" + "addu\t%0, %1\n\t" + "sltu\t$1, %0, %1\n\t" + + "lw\t%1, 12(%2)\n\t" + "addu\t%0, $1\n\t" + "addu\t%0, %1\n\t" + "sltu\t$1, %0, %1\n\t" + + "lw\t%1, 0(%3)\n\t" + "addu\t%0, $1\n\t" + "addu\t%0, %1\n\t" + "sltu\t$1, %0, %1\n\t" + + "lw\t%1, 4(%3)\n\t" + "addu\t%0, $1\n\t" + "addu\t%0, %1\n\t" + "sltu\t$1, %0, %1\n\t" + + "lw\t%1, 8(%3)\n\t" + "addu\t%0, $1\n\t" + "addu\t%0, %1\n\t" + "sltu\t$1, %0, %1\n\t" + + "lw\t%1, 12(%3)\n\t" + "addu\t%0, $1\n\t" + "addu\t%0, %1\n\t" + "sltu\t$1, %0, %1\n\t" + + "addu\t%0, $1\t\t\t# Add final carry\n\t" + ".set\tpop" + : "=r" (sum), "=r" (proto) + : "r" (saddr), "r" (daddr), + "0" (htonl(len)), "1" (htonl(proto)), "r" (sum)); + + return csum_fold(sum); +} + +#endif /* _ASM_CHECKSUM_H */ |
