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Diffstat (limited to 'arch/ia64/lib/checksum.c')
-rw-r--r-- | arch/ia64/lib/checksum.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/arch/ia64/lib/checksum.c b/arch/ia64/lib/checksum.c new file mode 100644 index 000000000..d26517fe3 --- /dev/null +++ b/arch/ia64/lib/checksum.c @@ -0,0 +1,102 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Network checksum routines + * + * Copyright (C) 1999, 2003 Hewlett-Packard Co + * Stephane Eranian <eranian@hpl.hp.com> + * + * Most of the code coming from arch/alpha/lib/checksum.c + * + * This file contains network checksum routines that are better done + * in an architecture-specific manner due to speed.. + */ + +#include <linux/module.h> +#include <linux/string.h> + +#include <asm/byteorder.h> + +static inline unsigned short +from64to16 (unsigned long x) +{ + /* add up 32-bit words for 33 bits */ + x = (x & 0xffffffff) + (x >> 32); + /* add up 16-bit and 17-bit words for 17+c bits */ + x = (x & 0xffff) + (x >> 16); + /* add up 16-bit and 2-bit for 16+c bit */ + x = (x & 0xffff) + (x >> 16); + /* add up carry.. */ + x = (x & 0xffff) + (x >> 16); + return x; +} + +/* + * computes the checksum of the TCP/UDP pseudo-header + * returns a 16-bit checksum, already complemented. + */ +__sum16 +csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len, + __u8 proto, __wsum sum) +{ + return (__force __sum16)~from64to16( + (__force u64)saddr + (__force u64)daddr + + (__force u64)sum + ((len + proto) << 8)); +} + +EXPORT_SYMBOL(csum_tcpudp_magic); + +__wsum +csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len, + __u8 proto, __wsum sum) +{ + unsigned long result; + + result = (__force u64)saddr + (__force u64)daddr + + (__force u64)sum + ((len + proto) << 8); + + /* Fold down to 32-bits so we don't lose in the typedef-less network stack. */ + /* 64 to 33 */ + result = (result & 0xffffffff) + (result >> 32); + /* 33 to 32 */ + result = (result & 0xffffffff) + (result >> 32); + return (__force __wsum)result; +} +EXPORT_SYMBOL(csum_tcpudp_nofold); + +extern unsigned long do_csum (const unsigned char *, long); + +/* + * 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) +{ + u64 result = do_csum(buff, len); + + /* add in old sum, and carry.. */ + result += (__force u32)sum; + /* 32+c bits -> 32 bits */ + result = (result & 0xffffffff) + (result >> 32); + return (__force __wsum)result; +} + +EXPORT_SYMBOL(csum_partial); + +/* + * this routine is used for miscellaneous IP-like checksums, mainly + * in icmp.c + */ +__sum16 ip_compute_csum (const void *buff, int len) +{ + return (__force __sum16)~do_csum(buff,len); +} + +EXPORT_SYMBOL(ip_compute_csum); |