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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-v850/checksum.h | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
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-v850/checksum.h')
-rw-r--r-- | include/asm-v850/checksum.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/include/asm-v850/checksum.h b/include/asm-v850/checksum.h new file mode 100644 index 0000000..d3aedb7 --- /dev/null +++ b/include/asm-v850/checksum.h @@ -0,0 +1,115 @@ +/* + * include/asm-v850/checksum.h -- Checksum ops + * + * Copyright (C) 2001 NEC Corporation + * Copyright (C) 2001 Miles Bader <miles@gnu.org> + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file COPYING in the main directory of this + * archive for more details. + * + * Written by Miles Bader <miles@gnu.org> + */ + +#ifndef __V850_CHECKSUM_H__ +#define __V850_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); + +/* + * 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 + */ +extern unsigned csum_partial_copy (const char *src, char *dst, int len, + unsigned 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 csum_partial_copy_from_user (const char *src, char *dst, + int len, unsigned 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 long sum) +{ + unsigned int result; + /* + %0 %1 + hsw %1, %0 H L L H + add %1, %0 H L H+L+C H+L + */ + asm ("hsw %1, %0; add %1, %0" : "=&r" (result) : "r" (sum)); + return (~result) >> 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) +{ + int __carry; + __asm__ ("add %2, %0;" + "setf c, %1;" + "add %1, %0;" + "add %3, %0;" + "setf c, %1;" + "add %1, %0;" + "add %4, %0;" + "setf c, %1;" + "add %1, %0" + : "=&r" (sum), "=&r" (__carry) + : "r" (daddr), "r" (saddr), + "r" (ntohs (len) + (proto << 8)), + "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 /* __V850_CHECKSUM_H__ */ |