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Diffstat (limited to 'arch/mips/include/asm/checksum.h')
| -rw-r--r-- | arch/mips/include/asm/checksum.h | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/arch/mips/include/asm/checksum.h b/arch/mips/include/asm/checksum.h new file mode 100644 index 0000000..290485a --- /dev/null +++ b/arch/mips/include/asm/checksum.h @@ -0,0 +1,260 @@ +/* + * 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/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 + */ +__wsum csum_partial(const void *buff, int len, __wsum sum); + +__wsum __csum_partial_copy_user(const void *src, void *dst, + int len, __wsum sum, int *err_ptr); + +/* + * this is a new version of the above that records errors it finds in *errp, + * but continues and zeros 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) +{ + might_sleep(); + return __csum_partial_copy_user((__force void *)src, dst, + len, sum, err_ptr); +} + +/* + * Copy and checksum to user + */ +#define HAVE_CSUM_COPY_USER +static inline +__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len, + __wsum sum, int *err_ptr) +{ + might_sleep(); + if (access_ok(VERIFY_WRITE, dst, len)) + return __csum_partial_copy_user(src, (__force void *)dst, + len, sum, err_ptr); + if (len) + *err_ptr = -EFAULT; + + return (__force __wsum)-1; /* invalid checksum */ +} + +/* + * 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) + */ +__wsum csum_partial_copy_nocheck(const void *src, void *dst, + int len, __wsum sum); + +/* + * Fold a partial checksum without adding pseudo headers + */ +static inline __sum16 csum_fold(__wsum sum) +{ + __asm__( + " .set push # csum_fold\n" + " .set noat \n" + " sll $1, %0, 16 \n" + " addu %0, $1 \n" + " sltu $1, %0, $1 \n" + " srl %0, %0, 16 \n" + " addu %0, $1 \n" + " xori %0, 0xffff \n" + " .set pop" + : "=r" (sum) + : "0" (sum)); + + return (__force __sum16)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 __sum16 ip_fast_csum(const void *iph, unsigned int ihl) +{ + const unsigned int *word = iph; + const 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 __wsum csum_tcpudp_nofold(__be32 saddr, + __be32 daddr, unsigned short len, unsigned short proto, + __wsum sum) +{ + __asm__( + " .set push # csum_tcpudp_nofold\n" + " .set noat \n" +#ifdef CONFIG_32BIT + " addu %0, %2 \n" + " sltu $1, %0, %2 \n" + " addu %0, $1 \n" + + " addu %0, %3 \n" + " sltu $1, %0, %3 \n" + " addu %0, $1 \n" + + " addu %0, %4 \n" + " sltu $1, %0, %4 \n" + " addu %0, $1 \n" +#endif +#ifdef CONFIG_64BIT + " daddu %0, %2 \n" + " daddu %0, %3 \n" + " daddu %0, %4 \n" + " dsll32 $1, %0, 0 \n" + " daddu %0, $1 \n" + " dsra32 %0, %0, 0 \n" +#endif + " .set pop" + : "=r" (sum) + : "0" ((__force unsigned long)daddr), + "r" ((__force unsigned long)saddr), +#ifdef __MIPSEL__ + "r" ((proto + len) << 8), +#else + "r" (proto + len), +#endif + "r" ((__force unsigned long)sum)); + + return sum; +} + +/* + * 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)); +} + +#define _HAVE_ARCH_IPV6_CSUM +static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr, + const struct in6_addr *daddr, + __u32 len, unsigned short proto, + __wsum sum) +{ + __asm__( + " .set push # csum_ipv6_magic\n" + " .set noreorder \n" + " .set noat \n" + " addu %0, %5 # proto (long in network byte order)\n" + " sltu $1, %0, %5 \n" + " addu %0, $1 \n" + + " addu %0, %6 # csum\n" + " sltu $1, %0, %6 \n" + " lw %1, 0(%2) # four words source address\n" + " addu %0, $1 \n" + " addu %0, %1 \n" + " sltu $1, %0, %1 \n" + + " lw %1, 4(%2) \n" + " addu %0, $1 \n" + " addu %0, %1 \n" + " sltu $1, %0, %1 \n" + + " lw %1, 8(%2) \n" + " addu %0, $1 \n" + " addu %0, %1 \n" + " sltu $1, %0, %1 \n" + + " lw %1, 12(%2) \n" + " addu %0, $1 \n" + " addu %0, %1 \n" + " sltu $1, %0, %1 \n" + + " lw %1, 0(%3) \n" + " addu %0, $1 \n" + " addu %0, %1 \n" + " sltu $1, %0, %1 \n" + + " lw %1, 4(%3) \n" + " addu %0, $1 \n" + " addu %0, %1 \n" + " sltu $1, %0, %1 \n" + + " lw %1, 8(%3) \n" + " addu %0, $1 \n" + " addu %0, %1 \n" + " sltu $1, %0, %1 \n" + + " lw %1, 12(%3) \n" + " addu %0, $1 \n" + " addu %0, %1 \n" + " sltu $1, %0, %1 \n" + + " addu %0, $1 # Add final carry\n" + " .set pop" + : "=r" (sum), "=r" (proto) + : "r" (saddr), "r" (daddr), + "0" (htonl(len)), "1" (htonl(proto)), "r" (sum)); + + return csum_fold(sum); +} + +#endif /* _ASM_CHECKSUM_H */ |