diff options
author | Ralf Baechle <ralf@linux-mips.org> | 1998-03-17 22:05:47 +0000 |
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committer | Ralf Baechle <ralf@linux-mips.org> | 1998-03-17 22:05:47 +0000 |
commit | 27cfca1ec98e91261b1a5355d10a8996464b63af (patch) | |
tree | 8e895a53e372fa682b4c0a585b9377d67ed70d0e /include/asm-arm/checksum.h | |
parent | 6a76fb7214c477ccf6582bd79c5b4ccc4f9c41b1 (diff) |
Look Ma' what I found on my harddisk ...
o New faster syscalls for 2.1.x, too
o Upgrade to 2.1.89.
Don't try to run this. It's flaky as hell. But feel free to debug ...
Diffstat (limited to 'include/asm-arm/checksum.h')
-rw-r--r-- | include/asm-arm/checksum.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/include/asm-arm/checksum.h b/include/asm-arm/checksum.h new file mode 100644 index 000000000..ccfadd761 --- /dev/null +++ b/include/asm-arm/checksum.h @@ -0,0 +1,154 @@ +/* + * linux/include/asm-arm/checksum.h + * + * IP checksum routines + * + * Copyright (C) Original authors of ../asm-i386/checksum.h + * Copyright (C) 1996,1997,1998 Russell King + */ +#ifndef __ASM_ARM_CHECKSUM_H +#define __ASM_ARM_CHECKSUM_H + +#ifndef __ASM_ARM_SEGMENT_H +#include <asm/segment.h> +#endif + +/* + * 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, and handles user-space pointer exceptions correctly, when needed. + * + * 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 char *src, char *dst, int len, int sum, int *err_ptr); + +/* + * This combination is currently not used, but possible: + */ +extern +unsigned int csum_partial_copy_to_user (const char *src, char *dst, int len, int sum, int *err_ptr); + +/* + * These are the old (and unsafe) way of doing checksums, a warning message will be + * printed if they are used and an exception occurs. + * + * these functions should go away after some time. + */ +#define csum_partial_copy_fromuser csum_partial_copy +unsigned int csum_partial_copy(const char *src, 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. + * + * Converted and optimised for ARM by R. M. King. + * + * Note: the order that the LDM registers are loaded with respect to + * the adc's doesn't matter. + */ +static inline unsigned short ip_fast_csum(unsigned char * iph, + unsigned int ihl) { + unsigned int sum, tmp1; + + __asm__ __volatile__(" + sub %2, %2, #5 + ldr %0, [%1], #4 + ldr %3, [%1], #4 + adds %0, %0, %3 + ldr %3, [%1], #4 + adcs %0, %0, %3 + ldr %3, [%1], #4 + adcs %0, %0, %3 +1: ldr %3, [%1], #4 + adcs %0, %0, %3 + tst %2, #15 + subne %2, %2, #1 + bne 1b + adc %0, %0, #0 + adds %0, %0, %0, lsl #16 + addcs %0, %0, #0x10000 + mvn %0, %0 + mov %0, %0, lsr #16 + " + : "=&r" (sum), "=&r" (iph), "=&r" (ihl), "=&r" (tmp1) + : "1" (iph), "2" (ihl)); + 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) { + __asm__ __volatile__(" + adds %0, %0, %1 + adcs %0, %0, %4 + adcs %0, %0, %5 + adc %0, %0, #0 + adds %0, %0, %0, lsl #16 + addcs %0, %0, #0x10000 + mvn %0, %0 + mov %0, %0, lsr #16 + " + : "=&r" (sum), "=&r" (saddr) + : "0" (daddr), "1"(saddr), "r"((ntohs(len)<<16)+proto*256), "r"(sum)); + return((unsigned short)sum); +} + +/* + * Fold a partial checksum without adding pseudo headers + */ +static inline unsigned int csum_fold(unsigned int sum) +{ + __asm__ __volatile__(" + adds %0, %0, %0, lsl #16 + addcs %0, %0, #0x10000 + mvn %0, %0 + mov %0, %0, lsr #16 + " + : "=r" (sum) + : "0" (sum)); + return 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) { + unsigned int sum; + + __asm__ __volatile__(" + adds %0, %0, %0, lsl #16 + addcs %0, %0, #0x10000 + mvn %0, %0 + mov %0, %0, lsr #16 + " + : "=r"(sum) + : "0" (csum_partial(buff, len, 0))); + return(sum); +} + +#endif |