| Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 1 | #ifndef _BFIN_CHECKSUM_H |
| 2 | #define _BFIN_CHECKSUM_H |
| 3 | |
| 4 | /* |
| 5 | * MODIFIED FOR BFIN April 30, 2001 akbar.hussain@lineo.com |
| 6 | * |
| 7 | * computes the checksum of a memory block at buff, length len, |
| 8 | * and adds in "sum" (32-bit) |
| 9 | * |
| 10 | * returns a 32-bit number suitable for feeding into itself |
| 11 | * or csum_tcpudp_magic |
| 12 | * |
| 13 | * this function must be called with even lengths, except |
| 14 | * for the last fragment, which may be odd |
| 15 | * |
| 16 | * it's best to have buff aligned on a 32-bit boundary |
| 17 | */ |
| 18 | unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum); |
| 19 | |
| 20 | /* |
| 21 | * the same as csum_partial, but copies from src while it |
| 22 | * checksums |
| 23 | * |
| 24 | * here even more important to align src and dst on a 32-bit (or even |
| 25 | * better 64-bit) boundary |
| 26 | */ |
| 27 | |
| 28 | unsigned int csum_partial_copy(const unsigned char *src, unsigned char *dst, |
| 29 | int len, int sum); |
| 30 | |
| 31 | /* |
| 32 | * the same as csum_partial_copy, but copies from user space. |
| 33 | * |
| 34 | * here even more important to align src and dst on a 32-bit (or even |
| 35 | * better 64-bit) boundary |
| 36 | */ |
| 37 | |
| 38 | extern unsigned int csum_partial_copy_from_user(const unsigned char *src, |
| 39 | unsigned char *dst, int len, |
| 40 | int sum, int *csum_err); |
| 41 | |
| 42 | #define csum_partial_copy_nocheck(src, dst, len, sum) \ |
| 43 | csum_partial_copy((src), (dst), (len), (sum)) |
| 44 | |
| 45 | unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl); |
| 46 | |
| 47 | /* |
| 48 | * Fold a partial checksum |
| 49 | */ |
| 50 | |
| 51 | static inline unsigned int csum_fold(unsigned int sum) |
| 52 | { |
| 53 | while (sum >> 16) |
| 54 | sum = (sum & 0xffff) + (sum >> 16); |
| 55 | return ((~(sum << 16)) >> 16); |
| 56 | } |
| 57 | |
| 58 | /* |
| 59 | * computes the checksum of the TCP/UDP pseudo-header |
| 60 | * returns a 16-bit checksum, already complemented |
| 61 | */ |
| 62 | |
| 63 | static inline unsigned int |
| 64 | csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len, |
| 65 | unsigned short proto, unsigned int sum) |
| 66 | { |
| 67 | |
| 68 | __asm__ ("%0 = %0 + %1;\n\t" |
| 69 | "CC = AC0;\n\t" |
| 70 | "if !CC jump 4;\n\t" |
| 71 | "%0 = %0 + %4;\n\t" |
| 72 | "%0 = %0 + %2;\n\t" |
| 73 | "CC = AC0;\n\t" |
| 74 | "if !CC jump 4;\n\t" |
| 75 | "%0 = %0 + %4;\n\t" |
| 76 | "%0 = %0 + %3;\n\t" |
| 77 | "CC = AC0;\n\t" |
| 78 | "if !CC jump 4;\n\t" |
| 79 | "%0 = %0 + %4;\n\t" |
| 80 | "NOP;\n\t" |
| 81 | : "=d" (sum) |
| 82 | : "d" (daddr), "d" (saddr), "d" ((ntohs(len)<<16)+proto*256), "d" (1), "0"(sum)); |
| 83 | |
| 84 | return (sum); |
| 85 | } |
| 86 | |
| 87 | static inline unsigned short int |
| 88 | csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len, |
| 89 | unsigned short proto, unsigned int sum) |
| 90 | { |
| 91 | return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); |
| 92 | } |
| 93 | |
| 94 | /* |
| 95 | * this routine is used for miscellaneous IP-like checksums, mainly |
| 96 | * in icmp.c |
| 97 | */ |
| 98 | |
| 99 | extern unsigned short ip_compute_csum(const unsigned char *buff, int len); |
| 100 | |
| 101 | #endif /* _BFIN_CHECKSUM_H */ |