diff options
Diffstat (limited to 'pfinet/linux-src/include/asm-ppc')
-rw-r--r-- | pfinet/linux-src/include/asm-ppc/checksum.h | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/pfinet/linux-src/include/asm-ppc/checksum.h b/pfinet/linux-src/include/asm-ppc/checksum.h new file mode 100644 index 00000000..e635ff59 --- /dev/null +++ b/pfinet/linux-src/include/asm-ppc/checksum.h @@ -0,0 +1,113 @@ +#ifndef _PPC_CHECKSUM_H +#define _PPC_CHECKSUM_H + + +/* + * 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 + */ +extern unsigned int csum_partial(const unsigned char * buff, int len, + unsigned int sum); + +/* + * Computes the checksum of a memory block at src, length len, + * and adds in "sum" (32-bit), while copying the block to dst. + * If an access exception occurs on src or dst, it stores -EFAULT + * to *src_err or *dst_err respectively (if that pointer is not + * NULL), and, for an error on src, zeroes the rest of dst. + * + * Like csum_partial, this must be called with even lengths, + * except for the last fragment. + */ +extern unsigned int csum_partial_copy_generic(const char *src, char *dst, + int len, unsigned int sum, + int *src_err, int *dst_err); + +#define csum_partial_copy_from_user(src, dst, len, sum, errp) \ + csum_partial_copy_generic((src), (dst), (len), (sum), (errp), 0) + +/* FIXME: this needs to be written to really do no check -- Cort */ +#define csum_partial_copy_nocheck(src, dst, len, sum) \ + csum_partial_copy_generic((src), (dst), (len), (sum), 0, 0) +/* + * Old versions which ignore errors. + */ +#define csum_partial_copy(src, dst, len, sum) \ + csum_partial_copy_generic((src), (dst), (len), (sum), 0, 0) +#define csum_partial_copy_fromuser(src, dst, len, sum) \ + csum_partial_copy_generic((src), (dst), (len), (sum), 0, 0) + + +/* + * turns a 32-bit partial checksum (e.g. from csum_partial) into a + * 1's complement 16-bit checksum. + */ +static inline unsigned int csum_fold(unsigned int sum) +{ + unsigned int tmp; + + /* swap the two 16-bit halves of sum */ + __asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum)); + /* if there is a carry from adding the two 16-bit halves, + it will carry from the lower half into the upper half, + giving us the correct sum in the upper half. */ + sum = ~(sum + tmp) >> 16; + return sum; +} + +/* + * this routine is used for miscellaneous IP-like checksums, mainly + * in icmp.c + */ +static inline unsigned short ip_compute_csum(unsigned char * buff, int len) +{ + return csum_fold(csum_partial(buff, len, 0)); +} + +/* + * FIXME: I swiped this one from the sparc and made minor modifications. + * It may not be correct. -- Cort + */ +static inline unsigned long csum_tcpudp_nofold(unsigned long saddr, + unsigned long daddr, + unsigned short len, + unsigned short proto, + unsigned int sum) +{ + __asm__(" + addc %0,%0,%1 + adde %0,%0,%2 + adde %0,%0,%3 + addze %0,%0 + " + : "=r" (sum) + : "r" (daddr), "r"(saddr), "r"((proto<<16)+len), "0"(sum)); + return sum; +} + +/* + * This is a version of ip_compute_csum() optimized for IP headers, + * which always checksum on 4 octet boundaries. ihl is the number + * of 32-bit words and is always >= 5. + */ +extern unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl); + +/* + * computes the checksum of the TCP/UDP pseudo-header + * returns a 16-bit checksum, already complemented + */ +extern unsigned short csum_tcpudp_magic(unsigned long saddr, + unsigned long daddr, + unsigned short len, + unsigned short proto, + unsigned int sum); + +#endif |