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Diffstat (limited to 'include/asm-xtensa/checksum.h')
| -rw-r--r-- | include/asm-xtensa/checksum.h | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/include/asm-xtensa/checksum.h b/include/asm-xtensa/checksum.h new file mode 100644 index 000000000000..1a00fad19929 --- /dev/null +++ b/include/asm-xtensa/checksum.h @@ -0,0 +1,264 @@ +/* + * include/asm-xtensa/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) 2001 - 2005 Tensilica Inc. + */ + +#ifndef _XTENSA_CHECKSUM_H +#define _XTENSA_CHECKSUM_H + +#include <linux/config.h> +#include <linux/in6.h> +#include <xtensa/config/core.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 char *src, 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(). + */ +extern __inline__ +unsigned int csum_partial_copy_nocheck ( const char *src, char *dst, + int len, int sum) +{ + return csum_partial_copy_generic ( src, dst, len, sum, NULL, NULL); +} + +extern __inline__ +unsigned int csum_partial_copy_from_user ( const char *src, char *dst, + int len, int sum, int *err_ptr) +{ + return csum_partial_copy_generic ( src, dst, len, sum, err_ptr, NULL); +} + +/* + * These are the old (and unsafe) way of doing checksums, a warning message will be + * printed if they are used and an exeption 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); + +/* + * Fold a partial checksum + */ + +static __inline__ unsigned int csum_fold(unsigned int sum) +{ + unsigned int __dummy; + __asm__("extui %1, %0, 16, 16\n\t" + "extui %0 ,%0, 0, 16\n\t" + "add %0, %0, %1\n\t" + "slli %1, %0, 16\n\t" + "add %0, %0, %1\n\t" + "extui %0, %0, 16, 16\n\t" + "neg %0, %0\n\t" + "addi %0, %0, -1\n\t" + "extui %0, %0, 0, 16\n\t" + : "=r" (sum), "=&r" (__dummy) + : "0" (sum)); + return 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, tmp, endaddr; + + __asm__ __volatile__( + "sub %0, %0, %0\n\t" +#if XCHAL_HAVE_LOOPS + "loopgtz %2, 2f\n\t" +#else + "beqz %2, 2f\n\t" + "slli %4, %2, 2\n\t" + "add %4, %4, %1\n\t" + "0:\t" +#endif + "l32i %3, %1, 0\n\t" + "add %0, %0, %3\n\t" + "bgeu %0, %3, 1f\n\t" + "addi %0, %0, 1\n\t" + "1:\t" + "addi %1, %1, 4\n\t" +#if !XCHAL_HAVE_LOOPS + "blt %1, %4, 0b\n\t" +#endif + "2:\t" + /* 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" (tmp), "=&r" (endaddr) + : "1" (iph), "2" (ihl)); + + 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 __XTENSA_EL__ + unsigned long len_proto = (ntohs(len)<<16)+proto*256; +#elif defined(__XTENSA_EB__) + unsigned long len_proto = (proto<<16)+len; +#else +# error processor byte order undefined! +#endif + __asm__("add %0, %0, %1\n\t" + "bgeu %0, %1, 1f\n\t" + "addi %0, %0, 1\n\t" + "1:\t" + "add %0, %0, %2\n\t" + "bgeu %0, %2, 1f\n\t" + "addi %0, %0, 1\n\t" + "1:\t" + "add %0, %0, %3\n\t" + "bgeu %0, %3, 1f\n\t" + "addi %0, %0, 1\n\t" + "1:\t" + : "=r" (sum), "=r" (len_proto) + : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum)); + 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__("l32i %1, %2, 0\n\t" + "add %0, %0, %1\n\t" + "bgeu %0, %1, 1f\n\t" + "addi %0, %0, 1\n\t" + "1:\t" + "l32i %1, %2, 4\n\t" + "add %0, %0, %1\n\t" + "bgeu %0, %1, 1f\n\t" + "addi %0, %0, 1\n\t" + "1:\t" + "l32i %1, %2, 8\n\t" + "add %0, %0, %1\n\t" + "bgeu %0, %1, 1f\n\t" + "addi %0, %0, 1\n\t" + "1:\t" + "l32i %1, %2, 12\n\t" + "add %0, %0, %1\n\t" + "bgeu %0, %1, 1f\n\t" + "addi %0, %0, 1\n\t" + "1:\t" + "l32i %1, %3, 0\n\t" + "add %0, %0, %1\n\t" + "bgeu %0, %1, 1f\n\t" + "addi %0, %0, 1\n\t" + "1:\t" + "l32i %1, %3, 4\n\t" + "add %0, %0, %1\n\t" + "bgeu %0, %1, 1f\n\t" + "addi %0, %0, 1\n\t" + "1:\t" + "l32i %1, %3, 8\n\t" + "add %0, %0, %1\n\t" + "bgeu %0, %1, 1f\n\t" + "addi %0, %0, 1\n\t" + "1:\t" + "l32i %1, %3, 12\n\t" + "add %0, %0, %1\n\t" + "bgeu %0, %1, 1f\n\t" + "addi %0, %0, 1\n\t" + "1:\t" + "add %0, %0, %4\n\t" + "bgeu %0, %4, 1f\n\t" + "addi %0, %0, 1\n\t" + "1:\t" + "add %0, %0, %5\n\t" + "bgeu %0, %5, 1f\n\t" + "addi %0, %0, 1\n\t" + "1:\t" + : "=r" (sum), "=&r" (__dummy) + : "r" (saddr), "r" (daddr), + "r" (htonl(len)), "r" (htonl(proto)), "0" (sum)); + + return csum_fold(sum); +} + +/* + * Copy and checksum to user + */ +#define HAVE_CSUM_COPY_USER +static __inline__ unsigned int csum_and_copy_to_user (const char *src, char *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 |
