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Diffstat (limited to 'include/asm-arm/checksum.h')
| -rw-r--r-- | include/asm-arm/checksum.h | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/include/asm-arm/checksum.h b/include/asm-arm/checksum.h new file mode 100644 index 00000000000..d4256d5f3a7 --- /dev/null +++ b/include/asm-arm/checksum.h @@ -0,0 +1,160 @@ +/* + * linux/include/asm-arm/checksum.h + * + * IP checksum routines + * + * Copyright (C) Original authors of ../asm-i386/checksum.h + * Copyright (C) 1996-1999 Russell King + */ +#ifndef __ASM_ARM_CHECKSUM_H +#define __ASM_ARM_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, 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 + */ + +unsigned int +csum_partial_copy_nocheck(const char *src, char *dst, int len, int sum); + +unsigned int +csum_partial_copy_from_user(const char __user *src, char *dst, int len, int sum, int *err_ptr); + +/* + * This is the old (and unsafe) way of doing checksums, a warning message will + * be printed if it is used and an exception occurs. + * + * this functions should go away after some time. + */ +#define csum_partial_copy(src,dst,len,sum) csum_partial_copy_nocheck(src,dst,len,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, tmp1; + + __asm__ __volatile__( + "ldr %0, [%1], #4 @ ip_fast_csum \n\ + ldr %3, [%1], #4 \n\ + sub %2, %2, #5 \n\ + adds %0, %0, %3 \n\ + ldr %3, [%1], #4 \n\ + adcs %0, %0, %3 \n\ + ldr %3, [%1], #4 \n\ +1: adcs %0, %0, %3 \n\ + ldr %3, [%1], #4 \n\ + tst %2, #15 @ do this carefully \n\ + subne %2, %2, #1 @ without destroying \n\ + bne 1b @ the carry flag \n\ + adcs %0, %0, %3 \n\ + adc %0, %0, #0 \n\ + adds %0, %0, %0, lsl #16 \n\ + addcs %0, %0, #0x10000 \n\ + mvn %0, %0 \n\ + mov %0, %0, lsr #16" + : "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (tmp1) + : "1" (iph), "2" (ihl) + : "cc"); + return sum; +} + +/* + * Fold a partial checksum without adding pseudo headers + */ +static inline unsigned int +csum_fold(unsigned int sum) +{ + __asm__( + "adds %0, %1, %1, lsl #16 @ csum_fold \n\ + addcs %0, %0, #0x10000" + : "=r" (sum) + : "r" (sum) + : "cc"); + return (~sum) >> 16; +} + +static inline unsigned int +csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len, + unsigned int proto, unsigned int sum) +{ + __asm__( + "adds %0, %1, %2 @ csum_tcpudp_nofold \n\ + adcs %0, %0, %3 \n\ + adcs %0, %0, %4 \n\ + adcs %0, %0, %5 \n\ + adc %0, %0, #0" + : "=&r"(sum) + : "r" (sum), "r" (daddr), "r" (saddr), "r" (ntohs(len)), "Ir" (ntohs(proto)) + : "cc"); + 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 int proto, unsigned int sum) +{ + __asm__( + "adds %0, %1, %2 @ csum_tcpudp_magic \n\ + adcs %0, %0, %3 \n\ + adcs %0, %0, %4 \n\ + adcs %0, %0, %5 \n\ + adc %0, %0, #0 \n\ + adds %0, %0, %0, lsl #16 \n\ + addcs %0, %0, #0x10000 \n\ + mvn %0, %0" + : "=&r"(sum) + : "r" (sum), "r" (daddr), "r" (saddr), "r" (ntohs(len)), "Ir" (ntohs(proto)) + : "cc"); + return sum >> 16; +} + + +/* + * 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 +extern unsigned long +__csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, __u32 len, + __u32 proto, unsigned int sum); + +static inline unsigned short int +csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, __u32 len, + unsigned short proto, unsigned int sum) +{ + return csum_fold(__csum_ipv6_magic(saddr, daddr, htonl(len), + htonl(proto), sum)); +} +#endif |