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Diffstat (limited to 'include/asm-sh/checksum.h')
| -rw-r--r-- | include/asm-sh/checksum.h | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/include/asm-sh/checksum.h b/include/asm-sh/checksum.h new file mode 100644 index 0000000..5113c7f --- /dev/null +++ b/include/asm-sh/checksum.h @@ -0,0 +1,216 @@ +#ifndef __ASM_SH_CHECKSUM_H +#define __ASM_SH_CHECKSUM_H + +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1999 by Kaz Kojima & Niibe Yutaka + */ + +#include <linux/config.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 + */ +asmlinkage 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 + */ + +asmlinkage unsigned int csum_partial_copy_generic(const unsigned char *src, unsigned char *dst, + int len, int sum, int *src_err_ptr, int *dst_err_ptr); + +/* + * Note: when you get a NULL pointer exception here this means someone + * passed in an incorrect kernel address to one of these functions. + * + * If you use these functions directly please don't forget the + * verify_area(). + */ +static __inline__ +unsigned int csum_partial_copy_nocheck (const unsigned char *src, unsigned char *dst, + int len, int sum) +{ + return csum_partial_copy_generic ( src, dst, len, sum, NULL, NULL); +} + +static __inline__ +unsigned int csum_partial_copy_from_user (const unsigned char *src, unsigned char *dst, + int len, int sum, int *err_ptr) +{ + return csum_partial_copy_generic ( src, dst, len, sum, err_ptr, NULL); +} + +/* + * Fold a partial checksum + */ + +static __inline__ unsigned int csum_fold(unsigned int sum) +{ + unsigned int __dummy; + __asm__("swap.w %0, %1\n\t" + "extu.w %0, %0\n\t" + "extu.w %1, %1\n\t" + "add %1, %0\n\t" + "swap.w %0, %1\n\t" + "add %1, %0\n\t" + "not %0, %0\n\t" + : "=r" (sum), "=&r" (__dummy) + : "0" (sum) + : "t"); + return sum; +} + +/* + * This is a version of ip_compute_csum() optimized for IP headers, + * which always checksum on 4 octet boundaries. + * + * i386 version by Jorge Cwik <jorge@laser.satlink.net>, adapted + * for linux by * Arnt Gulbrandsen. + */ +static __inline__ unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl) +{ + unsigned int sum, __dummy0, __dummy1; + + __asm__ __volatile__( + "mov.l @%1+, %0\n\t" + "mov.l @%1+, %3\n\t" + "add #-2, %2\n\t" + "clrt\n\t" + "1:\t" + "addc %3, %0\n\t" + "movt %4\n\t" + "mov.l @%1+, %3\n\t" + "dt %2\n\t" + "bf/s 1b\n\t" + " cmp/eq #1, %4\n\t" + "addc %3, %0\n\t" + "addc %2, %0" /* Here %2 is 0, add carry-bit */ + /* Since the input registers which are loaded with iph and ihl + are modified, we must also specify them as outputs, or gcc + will assume they contain their original values. */ + : "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (__dummy0), "=&z" (__dummy1) + : "1" (iph), "2" (ihl) + : "t"); + + return csum_fold(sum); +} + +static __inline__ unsigned long csum_tcpudp_nofold(unsigned long saddr, + unsigned long daddr, + unsigned short len, + unsigned short proto, + unsigned int sum) +{ +#ifdef __LITTLE_ENDIAN__ + unsigned long len_proto = (ntohs(len)<<16)+proto*256; +#else + unsigned long len_proto = (proto<<16)+len; +#endif + __asm__("clrt\n\t" + "addc %0, %1\n\t" + "addc %2, %1\n\t" + "addc %3, %1\n\t" + "movt %0\n\t" + "add %1, %0" + : "=r" (sum), "=r" (len_proto) + : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum) + : "t"); + 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) +{ + return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,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) +{ + return csum_fold (csum_partial(buff, len, 0)); +} + +#define _HAVE_ARCH_IPV6_CSUM +static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr, + struct in6_addr *daddr, + __u32 len, + unsigned short proto, + unsigned int sum) +{ + unsigned int __dummy; + __asm__("clrt\n\t" + "mov.l @(0,%2), %1\n\t" + "addc %1, %0\n\t" + "mov.l @(4,%2), %1\n\t" + "addc %1, %0\n\t" + "mov.l @(8,%2), %1\n\t" + "addc %1, %0\n\t" + "mov.l @(12,%2), %1\n\t" + "addc %1, %0\n\t" + "mov.l @(0,%3), %1\n\t" + "addc %1, %0\n\t" + "mov.l @(4,%3), %1\n\t" + "addc %1, %0\n\t" + "mov.l @(8,%3), %1\n\t" + "addc %1, %0\n\t" + "mov.l @(12,%3), %1\n\t" + "addc %1, %0\n\t" + "addc %4, %0\n\t" + "addc %5, %0\n\t" + "movt %1\n\t" + "add %1, %0\n" + : "=r" (sum), "=&r" (__dummy) + : "r" (saddr), "r" (daddr), + "r" (htonl(len)), "r" (htonl(proto)), "0" (sum) + : "t"); + + return csum_fold(sum); +} + +/* + * Copy and checksum to user + */ +#define HAVE_CSUM_COPY_USER +static __inline__ unsigned int csum_and_copy_to_user (const unsigned char *src, + unsigned char __user *dst, + int len, int sum, + int *err_ptr) +{ + if (access_ok(VERIFY_WRITE, dst, len)) + return csum_partial_copy_generic(src, dst, len, sum, NULL, err_ptr); + + if (len) + *err_ptr = -EFAULT; + + return -1; /* invalid checksum */ +} +#endif /* __ASM_SH_CHECKSUM_H */ |