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Diffstat (limited to 'include/asm-x86_64/checksum.h')
| -rw-r--r-- | include/asm-x86_64/checksum.h | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/include/asm-x86_64/checksum.h b/include/asm-x86_64/checksum.h new file mode 100644 index 00000000000..d01356f0144 --- /dev/null +++ b/include/asm-x86_64/checksum.h @@ -0,0 +1,193 @@ +#ifndef _X86_64_CHECKSUM_H +#define _X86_64_CHECKSUM_H + +/* + * Checksums for x86-64 + * Copyright 2002 by Andi Kleen, SuSE Labs + * with some code from asm-i386/checksum.h + */ + +#include <linux/compiler.h> +#include <asm/uaccess.h> +#include <asm/byteorder.h> + +/** + * csum_fold - Fold and invert a 32bit checksum. + * sum: 32bit unfolded sum + * + * Fold a 32bit running checksum to 16bit and invert it. This is usually + * the last step before putting a checksum into a packet. + * Make sure not to mix with 64bit checksums. + */ +static inline unsigned int csum_fold(unsigned int sum) +{ + __asm__( + " addl %1,%0\n" + " adcl $0xffff,%0" + : "=r" (sum) + : "r" (sum << 16), "0" (sum & 0xffff0000) + ); + return (~sum) >> 16; +} + +/* + * This is a version of ip_compute_csum() optimized for IP headers, + * which always checksum on 4 octet boundaries. + * + * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by + * Arnt Gulbrandsen. + */ + +/** + * ip_fast_csum - Compute the IPv4 header checksum efficiently. + * iph: ipv4 header + * ihl: length of header / 4 + */ +static inline unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl) +{ + unsigned int sum; + + asm( " movl (%1), %0\n" + " subl $4, %2\n" + " jbe 2f\n" + " addl 4(%1), %0\n" + " adcl 8(%1), %0\n" + " adcl 12(%1), %0\n" + "1: adcl 16(%1), %0\n" + " lea 4(%1), %1\n" + " decl %2\n" + " jne 1b\n" + " adcl $0, %0\n" + " movl %0, %2\n" + " shrl $16, %0\n" + " addw %w2, %w0\n" + " adcl $0, %0\n" + " notl %0\n" + "2:" + /* Since the input registers which are loaded with iph and ipl + are modified, we must also specify them as outputs, or gcc + will assume they contain their original values. */ + : "=r" (sum), "=r" (iph), "=r" (ihl) + : "1" (iph), "2" (ihl) + : "memory"); + return(sum); +} + +/** + * csum_tcpup_nofold - Compute an IPv4 pseudo header checksum. + * @saddr: source address + * @daddr: destination address + * @len: length of packet + * @proto: ip protocol of packet + * @sum: initial sum to be added in (32bit unfolded) + * + * Returns the pseudo header checksum the input data. Result is + * 32bit unfolded. + */ +static inline unsigned long +csum_tcpudp_nofold(unsigned saddr, unsigned daddr, unsigned short len, + unsigned short proto, unsigned int sum) +{ + asm(" addl %1, %0\n" + " adcl %2, %0\n" + " adcl %3, %0\n" + " adcl $0, %0\n" + : "=r" (sum) + : "g" (daddr), "g" (saddr), "g" ((ntohs(len)<<16)+proto*256), "0" (sum)); + return sum; +} + + +/** + * csum_tcpup_magic - Compute an IPv4 pseudo header checksum. + * @saddr: source address + * @daddr: destination address + * @len: length of packet + * @proto: ip protocol of packet + * @sum: initial sum to be added in (32bit unfolded) + * + * Returns the 16bit pseudo header checksum the input data already + * complemented and ready to be filled in. + */ +static inline unsigned short int +csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, + unsigned short len, unsigned short proto, unsigned int sum) +{ + return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); +} + +/** + * csum_partial - Compute an internet checksum. + * @buff: buffer to be checksummed + * @len: length of buffer. + * @sum: initial sum to be added in (32bit unfolded) + * + * Returns the 32bit unfolded internet checksum of the buffer. + * Before filling it in it needs to be csum_fold()'ed. + * buff should be aligned to a 64bit boundary if possible. + */ +extern unsigned int csum_partial(const unsigned char *buff, unsigned len, unsigned int sum); + +#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 1 +#define HAVE_CSUM_COPY_USER 1 + + +/* Do not call this directly. Use the wrappers below */ +extern unsigned long csum_partial_copy_generic(const unsigned char *src, const unsigned char *dst, + unsigned len, + unsigned sum, + int *src_err_ptr, int *dst_err_ptr); + + +extern unsigned int csum_partial_copy_from_user(const unsigned char __user *src, unsigned char *dst, + int len, unsigned int isum, int *errp); +extern unsigned int csum_partial_copy_to_user(const unsigned char *src, unsigned char __user *dst, + int len, unsigned int isum, int *errp); +extern unsigned int csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst, int len, + unsigned int sum); + +/* Old names. To be removed. */ +#define csum_and_copy_to_user csum_partial_copy_to_user +#define csum_and_copy_from_user csum_partial_copy_from_user + +/** + * ip_compute_csum - Compute an 16bit IP checksum. + * @buff: buffer address. + * @len: length of buffer. + * + * Returns the 16bit folded/inverted checksum of the passed buffer. + * Ready to fill in. + */ +extern unsigned short ip_compute_csum(unsigned char * buff, int len); + +/** + * csum_ipv6_magic - Compute checksum of an IPv6 pseudo header. + * @saddr: source address + * @daddr: destination address + * @len: length of packet + * @proto: protocol of packet + * @sum: initial sum (32bit unfolded) to be added in + * + * Computes an IPv6 pseudo header checksum. This sum is added the checksum + * into UDP/TCP packets and contains some link layer information. + * Returns the unfolded 32bit checksum. + */ + +struct in6_addr; + +#define _HAVE_ARCH_IPV6_CSUM 1 +extern unsigned short +csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, + __u32 len, unsigned short proto, unsigned int sum); + +static inline unsigned add32_with_carry(unsigned a, unsigned b) +{ + asm("addl %2,%0\n\t" + "adcl $0,%0" + : "=r" (a) + : "0" (a), "r" (b)); + return a; +} + +#endif + |