diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-11-01 09:51:51 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-11-01 09:51:51 -0700 |
commit | 0242909a6135e10a28822c64f9ad50fdad52757c (patch) | |
tree | c5f9c8abe95a65433e6ac356871f2379c02488fe /arch/cris/include/arch-v32/arch/checksum.h | |
parent | 0a6d2fac615972142715d736289abeeb7382e81d (diff) | |
parent | 556dcee7b829e5c350c3ffdbdb87a8b15aa3c5d3 (diff) |
Merge branch 'cris_move' of git://www.jni.nu/cris
* 'cris_move' of git://www.jni.nu/cris:
[CRIS] Move header files from include to arch/cris/include.
[CRISv32] Remove warning in io.h
Diffstat (limited to 'arch/cris/include/arch-v32/arch/checksum.h')
-rw-r--r-- | arch/cris/include/arch-v32/arch/checksum.h | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/arch/cris/include/arch-v32/arch/checksum.h b/arch/cris/include/arch-v32/arch/checksum.h new file mode 100644 index 00000000000..e5dcfce6e0d --- /dev/null +++ b/arch/cris/include/arch-v32/arch/checksum.h @@ -0,0 +1,29 @@ +#ifndef _ASM_CRIS_ARCH_CHECKSUM_H +#define _ASM_CRIS_ARCH_CHECKSUM_H + +/* + * Check values used in TCP/UDP headers. + * + * The gain of doing this in assembler instead of C, is that C doesn't + * generate carry-additions for the 32-bit components of the + * checksum. Which means it would be necessary to split all those into + * 16-bit components and then add. + */ +static inline __wsum +csum_tcpudp_nofold(__be32 saddr, __be32 daddr, + unsigned short len, unsigned short proto, __wsum sum) +{ + __wsum res; + + __asm__ __volatile__ ("add.d %2, %0\n\t" + "addc %3, %0\n\t" + "addc %4, %0\n\t" + "addc 0, %0\n\t" + : "=r" (res) + : "0" (sum), "r" (daddr), "r" (saddr), \ + "r" ((len + proto) << 8)); + + return res; +} + +#endif /* _ASM_CRIS_ARCH_CHECKSUM_H */ |