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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-m68k/checksum.h | |
download | lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-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-m68k/checksum.h')
-rw-r--r-- | include/asm-m68k/checksum.h | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/include/asm-m68k/checksum.h b/include/asm-m68k/checksum.h new file mode 100644 index 000000000000..78860c20db01 --- /dev/null +++ b/include/asm-m68k/checksum.h @@ -0,0 +1,150 @@ +#ifndef _M68K_CHECKSUM_H +#define _M68K_CHECKSUM_H + +#include <linux/in6.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 + */ +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 int csum_partial_copy_from_user(const unsigned char *src, + unsigned char *dst, + int len, int sum, + int *csum_err); + +extern unsigned int csum_partial_copy_nocheck(const unsigned char *src, + unsigned char *dst, int len, + int sum); + +/* + * This is a version of ip_compute_csum() optimized for IP headers, + * which always checksum on 4 octet boundaries. + * + */ +static inline unsigned short +ip_fast_csum(unsigned char *iph, unsigned int ihl) +{ + unsigned int sum = 0; + unsigned long tmp; + + __asm__ ("subqw #1,%2\n" + "1:\t" + "movel %1@+,%3\n\t" + "addxl %3,%0\n\t" + "dbra %2,1b\n\t" + "movel %0,%3\n\t" + "swap %3\n\t" + "addxw %3,%0\n\t" + "clrw %3\n\t" + "addxw %3,%0\n\t" + : "=d" (sum), "=&a" (iph), "=&d" (ihl), "=&d" (tmp) + : "0" (sum), "1" (iph), "2" (ihl) + : "memory"); + return ~sum; +} + +/* + * Fold a partial checksum + */ + +static inline unsigned int csum_fold(unsigned int sum) +{ + unsigned int tmp = sum; + __asm__("swap %1\n\t" + "addw %1, %0\n\t" + "clrw %1\n\t" + "addxw %1, %0" + : "=&d" (sum), "=&d" (tmp) + : "0" (sum), "1" (tmp)); + return ~sum; +} + + +static inline unsigned int +csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len, + unsigned short proto, unsigned int sum) +{ + __asm__ ("addl %2,%0\n\t" + "addxl %3,%0\n\t" + "addxl %4,%0\n\t" + "clrl %1\n\t" + "addxl %1,%0" + : "=&d" (sum), "=d" (saddr) + : "g" (daddr), "1" (saddr), "d" (len + proto), + "0" (sum)); + return sum; +} + + +/* + * computes the checksum of the TCP/UDP pseudo-header + * returns a 16-bit checksum, already complemented + */ +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 + */ + +static inline unsigned short +ip_compute_csum(unsigned char * buff, int len) +{ + return csum_fold (csum_partial(buff, len, 0)); +} + +#define _HAVE_ARCH_IPV6_CSUM +static __inline__ unsigned short int +csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, + __u32 len, unsigned short proto, unsigned int sum) +{ + register unsigned long tmp; + __asm__("addl %2@,%0\n\t" + "movel %2@(4),%1\n\t" + "addxl %1,%0\n\t" + "movel %2@(8),%1\n\t" + "addxl %1,%0\n\t" + "movel %2@(12),%1\n\t" + "addxl %1,%0\n\t" + "movel %3@,%1\n\t" + "addxl %1,%0\n\t" + "movel %3@(4),%1\n\t" + "addxl %1,%0\n\t" + "movel %3@(8),%1\n\t" + "addxl %1,%0\n\t" + "movel %3@(12),%1\n\t" + "addxl %1,%0\n\t" + "addxl %4,%0\n\t" + "clrl %1\n\t" + "addxl %1,%0" + : "=&d" (sum), "=&d" (tmp) + : "a" (saddr), "a" (daddr), "d" (len + proto), + "0" (sum)); + + return csum_fold(sum); +} + +#endif /* _M68K_CHECKSUM_H */ |