diff options
Diffstat (limited to 'include/asm-cris/arch-v10/checksum.h')
| -rw-r--r-- | include/asm-cris/arch-v10/checksum.h | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/include/asm-cris/arch-v10/checksum.h b/include/asm-cris/arch-v10/checksum.h new file mode 100644 index 00000000000..fde1d00aaa9 --- /dev/null +++ b/include/asm-cris/arch-v10/checksum.h @@ -0,0 +1,29 @@ +#ifndef _CRIS_ARCH_CHECKSUM_H +#define _CRIS_ARCH_CHECKSUM_H + +/* Checksum some values used in TCP/UDP headers. + * + * The gain by doing this in asm is that C will not generate carry-additions + * for the 32-bit components of the checksum, so otherwise we would have had + * to split all of those into 16-bit components, then add. + */ + +extern inline unsigned int +csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len, + unsigned short proto, unsigned int sum) +{ + int res; + __asm__ ("add.d %2, %0\n\t" + "ax\n\t" + "add.d %3, %0\n\t" + "ax\n\t" + "add.d %4, %0\n\t" + "ax\n\t" + "addq 0, %0\n" + : "=r" (res) + : "0" (sum), "r" (daddr), "r" (saddr), "r" ((ntohs(len) << 16) + (proto << 8))); + + return res; +} + +#endif |