diff options
Diffstat (limited to 'arch/cris/arch-v10/lib/old_checksum.c')
| -rw-r--r-- | arch/cris/arch-v10/lib/old_checksum.c | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/lib/old_checksum.c b/arch/cris/arch-v10/lib/old_checksum.c new file mode 100644 index 0000000..22a6f0a --- /dev/null +++ b/arch/cris/arch-v10/lib/old_checksum.c @@ -0,0 +1,85 @@ +/* $Id: old_checksum.c,v 1.3 2003/10/27 08:04:32 starvik Exp $ + * + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * IP/TCP/UDP checksumming routines + * + * Authors: Jorge Cwik, <jorge@laser.satlink.net> + * Arnt Gulbrandsen, <agulbra@nvg.unit.no> + * Tom May, <ftom@netcom.com> + * Lots of code moved from tcp.c and ip.c; see those files + * for more names. + * + * 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. + */ + +#include <net/checksum.h> +#include <net/module.h> + +#undef PROFILE_CHECKSUM + +#ifdef PROFILE_CHECKSUM +/* these are just for profiling the checksum code with an oscillioscope.. uh */ +#if 0 +#define BITOFF *((unsigned char *)0xb0000030) = 0xff +#define BITON *((unsigned char *)0xb0000030) = 0x0 +#endif +#include <asm/io.h> +#define CBITON LED_ACTIVE_SET(1) +#define CBITOFF LED_ACTIVE_SET(0) +#define BITOFF +#define BITON +#else +#define BITOFF +#define BITON +#define CBITOFF +#define CBITON +#endif + +/* + * computes a partial checksum, e.g. for TCP/UDP fragments + */ + +#include <asm/delay.h> + +unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum) +{ + /* + * Experiments with ethernet and slip connections show that buff + * is aligned on either a 2-byte or 4-byte boundary. + */ + const unsigned char *endMarker = buff + len; + const unsigned char *marker = endMarker - (len % 16); +#if 0 + if((int)buff & 0x3) + printk("unaligned buff %p\n", buff); + __delay(900); /* extra delay of 90 us to test performance hit */ +#endif + BITON; + while (buff < marker) { + sum += *((unsigned short *)buff)++; + sum += *((unsigned short *)buff)++; + sum += *((unsigned short *)buff)++; + sum += *((unsigned short *)buff)++; + sum += *((unsigned short *)buff)++; + sum += *((unsigned short *)buff)++; + sum += *((unsigned short *)buff)++; + sum += *((unsigned short *)buff)++; + } + marker = endMarker - (len % 2); + while(buff < marker) { + sum += *((unsigned short *)buff)++; + } + if(endMarker - buff > 0) { + sum += *buff; /* add extra byte seperately */ + } + BITOFF; + return(sum); +} + +EXPORT_SYMBOL(csum_partial); |