diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-ppc64/checksum.h |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/asm-ppc64/checksum.h')
-rw-r--r-- | include/asm-ppc64/checksum.h | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/include/asm-ppc64/checksum.h b/include/asm-ppc64/checksum.h new file mode 100644 index 00000000000..d22d4469de4 --- /dev/null +++ b/include/asm-ppc64/checksum.h @@ -0,0 +1,107 @@ +#ifndef _PPC64_CHECKSUM_H +#define _PPC64_CHECKSUM_H + +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +/* + * 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); + +/* + * 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); + +/* + * the same as csum_partial, but copies from src to dst while it + * checksums + */ +extern unsigned int csum_partial_copy_generic(const char *src, char *dst, + int len, unsigned int sum, + int *src_err, int *dst_err); +/* + * the same as csum_partial, but copies from src to dst while it + * checksums. + */ + +unsigned int csum_partial_copy_nocheck(const char *src, + char *dst, + int len, + unsigned int sum); + +/* + * 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)); +} + +#define csum_partial_copy_from_user(src, dst, len, sum, errp) \ + csum_partial_copy_generic((src), (dst), (len), (sum), (errp), NULL) + +#define csum_partial_copy_nocheck(src, dst, len, sum) \ + csum_partial_copy_generic((src), (dst), (len), (sum), NULL, NULL) + +static inline u32 csum_tcpudp_nofold(u32 saddr, + u32 daddr, + unsigned short len, + unsigned short proto, + unsigned int sum) +{ + unsigned long s = sum; + + s += saddr; + s += daddr; + s += (proto << 16) + len; + s += (s >> 32); + return (u32) s; +} + +#endif |