projects / mirror_ubuntu-focal-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 086e9dc0 JH |
1 | #ifndef _METAG_CHECKSUM_H |
| 2 | #define _METAG_CHECKSUM_H | |
| 3 | ||
| 4 | /* | |
| 5 | * computes the checksum of a memory block at buff, length len, | |
| 6 | * and adds in "sum" (32-bit) | |
| 7 | * | |
| 8 | * returns a 32-bit number suitable for feeding into itself | |
| 9 | * or csum_tcpudp_magic | |
| 10 | * | |
| 11 | * this function must be called with even lengths, except | |
| 12 | * for the last fragment, which may be odd | |
| 13 | * | |
| 14 | * it's best to have buff aligned on a 32-bit boundary | |
| 15 | */ | |
| 16 | extern __wsum csum_partial(const void *buff, int len, __wsum sum); | |
| 17 | ||
| 18 | /* | |
| 19 | * the same as csum_partial, but copies from src while it | |
| 20 | * checksums | |
| 21 | * | |
| 22 | * here even more important to align src and dst on a 32-bit (or even | |
| 23 | * better 64-bit) boundary | |
| 24 | */ | |
| 25 | extern __wsum csum_partial_copy(const void *src, void *dst, int len, | |
| 26 | __wsum sum); | |
| 27 | ||
| 28 | /* | |
| 29 | * the same as csum_partial_copy, but copies from user space. | |
| 30 | * | |
| 31 | * here even more important to align src and dst on a 32-bit (or even | |
| 32 | * better 64-bit) boundary | |
| 33 | */ | |
| 34 | extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst, | |
| 35 | int len, __wsum sum, int *csum_err); | |
| 36 | ||
| 37 | #define csum_partial_copy_nocheck(src, dst, len, sum) \ | |
| 38 | csum_partial_copy((src), (dst), (len), (sum)) | |
| 39 | ||
| 40 | /* | |
| 41 | * Fold a partial checksum | |
| 42 | */ | |
| 43 | static inline __sum16 csum_fold(__wsum csum) | |
| 44 | { | |
| 45 | u32 sum = (__force u32)csum; | |
| 46 | sum = (sum & 0xffff) + (sum >> 16); | |
| 47 | sum = (sum & 0xffff) + (sum >> 16); | |
| 48 | return (__force __sum16)~sum; | |
| 49 | } | |
| 50 | ||
| 51 | /* | |
| 52 | * This is a version of ip_compute_csum() optimized for IP headers, | |
| 53 | * which always checksum on 4 octet boundaries. | |
| 54 | */ | |
| 55 | extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl); | |
| 56 | ||
| 57 | /* | |
| 58 | * computes the checksum of the TCP/UDP pseudo-header | |
| 59 | * returns a 16-bit checksum, already complemented | |
| 60 | */ | |
| 61 | static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, | |
| 62 | unsigned short len, | |
| 63 | unsigned short proto, | |
| 64 | __wsum sum) | |
| 65 | { | |
| 66 | unsigned long len_proto = (proto + len) << 8; | |
| 67 | asm ("ADD %0, %0, %1\n" | |
| 68 | "ADDS %0, %0, %2\n" | |
| 69 | "ADDCS %0, %0, #1\n" | |
| 70 | "ADDS %0, %0, %3\n" | |
| 71 | "ADDCS %0, %0, #1\n" | |
| 72 | : "=d" (sum) | |
| 73 | : "d" (daddr), "d" (saddr), "d" (len_proto), | |
| 74 | "0" (sum) | |
| 75 | : "cc"); | |
| 76 | return sum; | |
| 77 | } | |
| 78 | ||
| 79 | static inline __sum16 | |
| 80 | csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len, | |
| 81 | unsigned short proto, __wsum sum) | |
| 82 | { | |
| 83 | return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); | |
| 84 | } | |
| 85 | ||
| 86 | /* | |
| 87 | * this routine is used for miscellaneous IP-like checksums, mainly | |
| 88 | * in icmp.c | |
| 89 | */ | |
| 90 | extern __sum16 ip_compute_csum(const void *buff, int len); | |
| 91 | ||
| 92 | #endif /* _METAG_CHECKSUM_H */ |