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132 lines
3.3 KiB
132 lines
3.3 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
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/* |
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* S390 fast network checksum routines |
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* |
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* S390 version |
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* Copyright IBM Corp. 1999 |
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* Author(s): Ulrich Hild (first version) |
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* Martin Schwidefsky (heavily optimized CKSM version) |
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* D.J. Barrow (third attempt) |
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*/ |
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#ifndef _S390_CHECKSUM_H |
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#define _S390_CHECKSUM_H |
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#include <linux/uaccess.h> |
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#include <linux/in6.h> |
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/* |
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* Computes the checksum of a memory block at buff, length len, |
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* and adds in "sum" (32-bit). |
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* |
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* Returns a 32-bit number suitable for feeding into itself |
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* or csum_tcpudp_magic. |
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* |
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* This function must be called with even lengths, except |
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* for the last fragment, which may be odd. |
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* |
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* It's best to have buff aligned on a 32-bit boundary. |
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*/ |
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static inline __wsum csum_partial(const void *buff, int len, __wsum sum) |
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{ |
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union register_pair rp = { |
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.even = (unsigned long) buff, |
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.odd = (unsigned long) len, |
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}; |
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asm volatile( |
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"0: cksm %[sum],%[rp]\n" |
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" jo 0b\n" |
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: [sum] "+&d" (sum), [rp] "+&d" (rp.pair) : : "cc", "memory"); |
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return sum; |
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} |
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/* |
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* Fold a partial checksum without adding pseudo headers. |
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*/ |
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static inline __sum16 csum_fold(__wsum sum) |
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{ |
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u32 csum = (__force u32) sum; |
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csum += (csum >> 16) | (csum << 16); |
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csum >>= 16; |
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return (__force __sum16) ~csum; |
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} |
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/* |
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* This is a version of ip_compute_csum() optimized for IP headers, |
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* which always checksums on 4 octet boundaries. |
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*/ |
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static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) |
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{ |
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__u64 csum = 0; |
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__u32 *ptr = (u32 *)iph; |
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csum += *ptr++; |
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csum += *ptr++; |
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csum += *ptr++; |
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csum += *ptr++; |
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ihl -= 4; |
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while (ihl--) |
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csum += *ptr++; |
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csum += (csum >> 32) | (csum << 32); |
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return csum_fold((__force __wsum)(csum >> 32)); |
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} |
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/* |
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* Computes the checksum of the TCP/UDP pseudo-header. |
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* Returns a 32-bit checksum. |
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*/ |
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static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len, |
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__u8 proto, __wsum sum) |
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{ |
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__u64 csum = (__force __u64)sum; |
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csum += (__force __u32)saddr; |
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csum += (__force __u32)daddr; |
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csum += len; |
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csum += proto; |
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csum += (csum >> 32) | (csum << 32); |
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return (__force __wsum)(csum >> 32); |
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} |
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/* |
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* Computes the checksum of the TCP/UDP pseudo-header. |
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* Returns a 16-bit checksum, already complemented. |
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*/ |
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static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len, |
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__u8 proto, __wsum sum) |
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{ |
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return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); |
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} |
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/* |
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* Used for miscellaneous IP-like checksums, mainly icmp. |
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*/ |
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static inline __sum16 ip_compute_csum(const void *buff, int len) |
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{ |
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return csum_fold(csum_partial(buff, len, 0)); |
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} |
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#define _HAVE_ARCH_IPV6_CSUM |
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static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr, |
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const struct in6_addr *daddr, |
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__u32 len, __u8 proto, __wsum csum) |
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{ |
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__u64 sum = (__force __u64)csum; |
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sum += (__force __u32)saddr->s6_addr32[0]; |
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sum += (__force __u32)saddr->s6_addr32[1]; |
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sum += (__force __u32)saddr->s6_addr32[2]; |
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sum += (__force __u32)saddr->s6_addr32[3]; |
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sum += (__force __u32)daddr->s6_addr32[0]; |
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sum += (__force __u32)daddr->s6_addr32[1]; |
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sum += (__force __u32)daddr->s6_addr32[2]; |
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sum += (__force __u32)daddr->s6_addr32[3]; |
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sum += len; |
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sum += proto; |
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sum += (sum >> 32) | (sum << 32); |
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return csum_fold((__force __wsum)(sum >> 32)); |
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} |
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#endif /* _S390_CHECKSUM_H */
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