diff options
Diffstat (limited to 'include/asm-blackfin/checksum.h')
-rw-r--r-- | include/asm-blackfin/checksum.h | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/include/asm-blackfin/checksum.h b/include/asm-blackfin/checksum.h new file mode 100644 index 000000000000..2638f2586d2f --- /dev/null +++ b/include/asm-blackfin/checksum.h @@ -0,0 +1,101 @@ +#ifndef _BFIN_CHECKSUM_H +#define _BFIN_CHECKSUM_H + +/* + * MODIFIED FOR BFIN April 30, 2001 akbar.hussain@lineo.com + * + * 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 + */ +unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum); + +/* + * the same as csum_partial, but copies from src while it + * checksums + * + * here even more important to align src and dst on a 32-bit (or even + * better 64-bit) boundary + */ + +unsigned int csum_partial_copy(const unsigned char *src, unsigned char *dst, + int len, int sum); + +/* + * the same as csum_partial_copy, but copies from user space. + * + * here even more important to align src and dst on a 32-bit (or even + * better 64-bit) boundary + */ + +extern unsigned int csum_partial_copy_from_user(const unsigned char *src, + unsigned char *dst, int len, + int sum, int *csum_err); + +#define csum_partial_copy_nocheck(src, dst, len, sum) \ + csum_partial_copy((src), (dst), (len), (sum)) + +unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl); + +/* + * Fold a partial checksum + */ + +static inline unsigned int csum_fold(unsigned int sum) +{ + while (sum >> 16) + sum = (sum & 0xffff) + (sum >> 16); + return ((~(sum << 16)) >> 16); +} + +/* + * computes the checksum of the TCP/UDP pseudo-header + * returns a 16-bit checksum, already complemented + */ + +static inline unsigned int +csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len, + unsigned short proto, unsigned int sum) +{ + + __asm__ ("%0 = %0 + %1;\n\t" + "CC = AC0;\n\t" + "if !CC jump 4;\n\t" + "%0 = %0 + %4;\n\t" + "%0 = %0 + %2;\n\t" + "CC = AC0;\n\t" + "if !CC jump 4;\n\t" + "%0 = %0 + %4;\n\t" + "%0 = %0 + %3;\n\t" + "CC = AC0;\n\t" + "if !CC jump 4;\n\t" + "%0 = %0 + %4;\n\t" + "NOP;\n\t" + : "=d" (sum) + : "d" (daddr), "d" (saddr), "d" ((ntohs(len)<<16)+proto*256), "d" (1), "0"(sum)); + + return (sum); +} + +static inline unsigned short int +csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len, + unsigned short proto, unsigned int 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 + */ + +extern unsigned short ip_compute_csum(const unsigned char *buff, int len); + +#endif /* _BFIN_CHECKSUM_H */ |