cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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checksum_32.h (5011B)


      1/* SPDX-License-Identifier: GPL-2.0 */
      2#ifndef __ASM_SH_CHECKSUM_H
      3#define __ASM_SH_CHECKSUM_H
      4
      5/*
      6 * Copyright (C) 1999 by Kaz Kojima & Niibe Yutaka
      7 */
      8
      9#include <linux/in6.h>
     10
     11/*
     12 * computes the checksum of a memory block at buff, length len,
     13 * and adds in "sum" (32-bit)
     14 *
     15 * returns a 32-bit number suitable for feeding into itself
     16 * or csum_tcpudp_magic
     17 *
     18 * this function must be called with even lengths, except
     19 * for the last fragment, which may be odd
     20 *
     21 * it's best to have buff aligned on a 32-bit boundary
     22 */
     23asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum);
     24
     25/*
     26 * the same as csum_partial, but copies from src while it
     27 * checksums, and handles user-space pointer exceptions correctly, when needed.
     28 *
     29 * here even more important to align src and dst on a 32-bit (or even
     30 * better 64-bit) boundary
     31 */
     32
     33asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, int len);
     34
     35#define _HAVE_ARCH_CSUM_AND_COPY
     36/*
     37 *	Note: when you get a NULL pointer exception here this means someone
     38 *	passed in an incorrect kernel address to one of these functions.
     39 *
     40 *	If you use these functions directly please don't forget the
     41 *	access_ok().
     42 */
     43static inline
     44__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)
     45{
     46	return csum_partial_copy_generic(src, dst, len);
     47}
     48
     49#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
     50static inline
     51__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len)
     52{
     53	if (!access_ok(src, len))
     54		return 0;
     55	return csum_partial_copy_generic((__force const void *)src, dst, len);
     56}
     57
     58/*
     59 *	Fold a partial checksum
     60 */
     61
     62static inline __sum16 csum_fold(__wsum sum)
     63{
     64	unsigned int __dummy;
     65	__asm__("swap.w %0, %1\n\t"
     66		"extu.w	%0, %0\n\t"
     67		"extu.w	%1, %1\n\t"
     68		"add	%1, %0\n\t"
     69		"swap.w	%0, %1\n\t"
     70		"add	%1, %0\n\t"
     71		"not	%0, %0\n\t"
     72		: "=r" (sum), "=&r" (__dummy)
     73		: "0" (sum)
     74		: "t");
     75	return (__force __sum16)sum;
     76}
     77
     78/*
     79 *	This is a version of ip_compute_csum() optimized for IP headers,
     80 *	which always checksum on 4 octet boundaries.
     81 *
     82 *      i386 version by Jorge Cwik <jorge@laser.satlink.net>, adapted
     83 *      for linux by * Arnt Gulbrandsen.
     84 */
     85static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
     86{
     87	__wsum sum;
     88	unsigned int __dummy0, __dummy1;
     89
     90	__asm__ __volatile__(
     91		"mov.l	@%1+, %0\n\t"
     92		"mov.l	@%1+, %3\n\t"
     93		"add	#-2, %2\n\t"
     94		"clrt\n\t"
     95		"1:\t"
     96		"addc	%3, %0\n\t"
     97		"movt	%4\n\t"
     98		"mov.l	@%1+, %3\n\t"
     99		"dt	%2\n\t"
    100		"bf/s	1b\n\t"
    101		" cmp/eq #1, %4\n\t"
    102		"addc	%3, %0\n\t"
    103		"addc	%2, %0"	    /* Here %2 is 0, add carry-bit */
    104	/* Since the input registers which are loaded with iph and ihl
    105	   are modified, we must also specify them as outputs, or gcc
    106	   will assume they contain their original values. */
    107	: "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (__dummy0), "=&z" (__dummy1)
    108	: "1" (iph), "2" (ihl)
    109	: "t", "memory");
    110
    111	return	csum_fold(sum);
    112}
    113
    114static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
    115					__u32 len, __u8 proto,
    116					__wsum sum)
    117{
    118#ifdef __LITTLE_ENDIAN__
    119	unsigned long len_proto = (proto + len) << 8;
    120#else
    121	unsigned long len_proto = proto + len;
    122#endif
    123	__asm__("clrt\n\t"
    124		"addc	%0, %1\n\t"
    125		"addc	%2, %1\n\t"
    126		"addc	%3, %1\n\t"
    127		"movt	%0\n\t"
    128		"add	%1, %0"
    129		: "=r" (sum), "=r" (len_proto)
    130		: "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum)
    131		: "t");
    132
    133	return sum;
    134}
    135
    136/*
    137 * computes the checksum of the TCP/UDP pseudo-header
    138 * returns a 16-bit checksum, already complemented
    139 */
    140static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
    141					__u32 len, __u8 proto,
    142					__wsum sum)
    143{
    144	return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
    145}
    146
    147/*
    148 * this routine is used for miscellaneous IP-like checksums, mainly
    149 * in icmp.c
    150 */
    151static inline __sum16 ip_compute_csum(const void *buff, int len)
    152{
    153    return csum_fold(csum_partial(buff, len, 0));
    154}
    155
    156#define _HAVE_ARCH_IPV6_CSUM
    157static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
    158				      const struct in6_addr *daddr,
    159				      __u32 len, __u8 proto, __wsum sum)
    160{
    161	unsigned int __dummy;
    162	__asm__("clrt\n\t"
    163		"mov.l	@(0,%2), %1\n\t"
    164		"addc	%1, %0\n\t"
    165		"mov.l	@(4,%2), %1\n\t"
    166		"addc	%1, %0\n\t"
    167		"mov.l	@(8,%2), %1\n\t"
    168		"addc	%1, %0\n\t"
    169		"mov.l	@(12,%2), %1\n\t"
    170		"addc	%1, %0\n\t"
    171		"mov.l	@(0,%3), %1\n\t"
    172		"addc	%1, %0\n\t"
    173		"mov.l	@(4,%3), %1\n\t"
    174		"addc	%1, %0\n\t"
    175		"mov.l	@(8,%3), %1\n\t"
    176		"addc	%1, %0\n\t"
    177		"mov.l	@(12,%3), %1\n\t"
    178		"addc	%1, %0\n\t"
    179		"addc	%4, %0\n\t"
    180		"addc	%5, %0\n\t"
    181		"movt	%1\n\t"
    182		"add	%1, %0\n"
    183		: "=r" (sum), "=&r" (__dummy)
    184		: "r" (saddr), "r" (daddr),
    185		  "r" (htonl(len)), "r" (htonl(proto)), "0" (sum)
    186		: "t");
    187
    188	return csum_fold(sum);
    189}
    190
    191/*
    192 *	Copy and checksum to user
    193 */
    194#define HAVE_CSUM_COPY_USER
    195static inline __wsum csum_and_copy_to_user(const void *src,
    196					   void __user *dst,
    197					   int len)
    198{
    199	if (!access_ok(dst, len))
    200		return 0;
    201	return csum_partial_copy_generic(src, (__force void *)dst, len);
    202}
    203#endif /* __ASM_SH_CHECKSUM_H */