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 (5791B)


      1/* SPDX-License-Identifier: GPL-2.0 */
      2#ifndef __SPARC_CHECKSUM_H
      3#define __SPARC_CHECKSUM_H
      4
      5/*  checksum.h:  IP/UDP/TCP checksum routines on the Sparc.
      6 *
      7 *  Copyright(C) 1995 Linus Torvalds
      8 *  Copyright(C) 1995 Miguel de Icaza
      9 *  Copyright(C) 1996 David S. Miller
     10 *  Copyright(C) 1996 Eddie C. Dost
     11 *  Copyright(C) 1997 Jakub Jelinek
     12 *
     13 * derived from:
     14 *	Alpha checksum c-code
     15 *      ix86 inline assembly
     16 *      RFC1071 Computing the Internet Checksum
     17 */
     18
     19#include <linux/in6.h>
     20#include <linux/uaccess.h>
     21
     22/* computes the checksum of a memory block at buff, length len,
     23 * and adds in "sum" (32-bit)
     24 *
     25 * returns a 32-bit number suitable for feeding into itself
     26 * or csum_tcpudp_magic
     27 *
     28 * this function must be called with even lengths, except
     29 * for the last fragment, which may be odd
     30 *
     31 * it's best to have buff aligned on a 32-bit boundary
     32 */
     33__wsum csum_partial(const void *buff, int len, __wsum sum);
     34
     35/* the same as csum_partial, but copies from fs:src while it
     36 * checksums
     37 *
     38 * here even more important to align src and dst on a 32-bit (or even
     39 * better 64-bit) boundary
     40 */
     41
     42unsigned int __csum_partial_copy_sparc_generic (const unsigned char *, unsigned char *);
     43
     44static inline __wsum
     45csum_partial_copy_nocheck(const void *src, void *dst, int len)
     46{
     47	register unsigned int ret asm("o0") = (unsigned int)src;
     48	register char *d asm("o1") = dst;
     49	register int l asm("g1") = len;
     50
     51	__asm__ __volatile__ (
     52		"call __csum_partial_copy_sparc_generic\n\t"
     53		" mov -1, %%g7\n"
     54	: "=&r" (ret), "=&r" (d), "=&r" (l)
     55	: "0" (ret), "1" (d), "2" (l)
     56	: "o2", "o3", "o4", "o5", "o7",
     57	  "g2", "g3", "g4", "g5", "g7",
     58	  "memory", "cc");
     59	return (__force __wsum)ret;
     60}
     61
     62static inline __wsum
     63csum_and_copy_from_user(const void __user *src, void *dst, int len)
     64{
     65	if (unlikely(!access_ok(src, len)))
     66		return 0;
     67	return csum_partial_copy_nocheck((__force void *)src, dst, len);
     68}
     69
     70static inline __wsum
     71csum_and_copy_to_user(const void *src, void __user *dst, int len)
     72{
     73	if (!access_ok(dst, len))
     74		return 0;
     75	return csum_partial_copy_nocheck(src, (__force void *)dst, len);
     76}
     77
     78/* ihl is always 5 or greater, almost always is 5, and iph is word aligned
     79 * the majority of the time.
     80 */
     81static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
     82{
     83	__sum16 sum;
     84
     85	/* Note: We must read %2 before we touch %0 for the first time,
     86	 *       because GCC can legitimately use the same register for
     87	 *       both operands.
     88	 */
     89	__asm__ __volatile__("sub\t%2, 4, %%g4\n\t"
     90			     "ld\t[%1 + 0x00], %0\n\t"
     91			     "ld\t[%1 + 0x04], %%g2\n\t"
     92			     "ld\t[%1 + 0x08], %%g3\n\t"
     93			     "addcc\t%%g2, %0, %0\n\t"
     94			     "addxcc\t%%g3, %0, %0\n\t"
     95			     "ld\t[%1 + 0x0c], %%g2\n\t"
     96			     "ld\t[%1 + 0x10], %%g3\n\t"
     97			     "addxcc\t%%g2, %0, %0\n\t"
     98			     "addx\t%0, %%g0, %0\n"
     99			     "1:\taddcc\t%%g3, %0, %0\n\t"
    100			     "add\t%1, 4, %1\n\t"
    101			     "addxcc\t%0, %%g0, %0\n\t"
    102			     "subcc\t%%g4, 1, %%g4\n\t"
    103			     "be,a\t2f\n\t"
    104			     "sll\t%0, 16, %%g2\n\t"
    105			     "b\t1b\n\t"
    106			     "ld\t[%1 + 0x10], %%g3\n"
    107			     "2:\taddcc\t%0, %%g2, %%g2\n\t"
    108			     "srl\t%%g2, 16, %0\n\t"
    109			     "addx\t%0, %%g0, %0\n\t"
    110			     "xnor\t%%g0, %0, %0"
    111			     : "=r" (sum), "=&r" (iph)
    112			     : "r" (ihl), "1" (iph)
    113			     : "g2", "g3", "g4", "cc", "memory");
    114	return sum;
    115}
    116
    117/* Fold a partial checksum without adding pseudo headers. */
    118static inline __sum16 csum_fold(__wsum sum)
    119{
    120	unsigned int tmp;
    121
    122	__asm__ __volatile__("addcc\t%0, %1, %1\n\t"
    123			     "srl\t%1, 16, %1\n\t"
    124			     "addx\t%1, %%g0, %1\n\t"
    125			     "xnor\t%%g0, %1, %0"
    126			     : "=&r" (sum), "=r" (tmp)
    127			     : "0" (sum), "1" ((__force u32)sum<<16)
    128			     : "cc");
    129	return (__force __sum16)sum;
    130}
    131
    132static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
    133					__u32 len, __u8 proto,
    134					__wsum sum)
    135{
    136	__asm__ __volatile__("addcc\t%1, %0, %0\n\t"
    137			     "addxcc\t%2, %0, %0\n\t"
    138			     "addxcc\t%3, %0, %0\n\t"
    139			     "addx\t%0, %%g0, %0\n\t"
    140			     : "=r" (sum), "=r" (saddr)
    141			     : "r" (daddr), "r" (proto + len), "0" (sum),
    142			       "1" (saddr)
    143			     : "cc");
    144	return sum;
    145}
    146
    147/*
    148 * computes the checksum of the TCP/UDP pseudo-header
    149 * returns a 16-bit checksum, already complemented
    150 */
    151static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
    152					__u32 len, __u8 proto,
    153					__wsum sum)
    154{
    155	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
    156}
    157
    158#define _HAVE_ARCH_IPV6_CSUM
    159
    160static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
    161				      const struct in6_addr *daddr,
    162				      __u32 len, __u8 proto, __wsum sum)
    163{
    164	__asm__ __volatile__ (
    165		"addcc	%3, %4, %%g4\n\t"
    166		"addxcc	%5, %%g4, %%g4\n\t"
    167		"ld	[%2 + 0x0c], %%g2\n\t"
    168		"ld	[%2 + 0x08], %%g3\n\t"
    169		"addxcc	%%g2, %%g4, %%g4\n\t"
    170		"ld	[%2 + 0x04], %%g2\n\t"
    171		"addxcc	%%g3, %%g4, %%g4\n\t"
    172		"ld	[%2 + 0x00], %%g3\n\t"
    173		"addxcc	%%g2, %%g4, %%g4\n\t"
    174		"ld	[%1 + 0x0c], %%g2\n\t"
    175		"addxcc	%%g3, %%g4, %%g4\n\t"
    176		"ld	[%1 + 0x08], %%g3\n\t"
    177		"addxcc	%%g2, %%g4, %%g4\n\t"
    178		"ld	[%1 + 0x04], %%g2\n\t"
    179		"addxcc	%%g3, %%g4, %%g4\n\t"
    180		"ld	[%1 + 0x00], %%g3\n\t"
    181		"addxcc	%%g2, %%g4, %%g4\n\t"
    182		"addxcc	%%g3, %%g4, %0\n\t"
    183		"addx	0, %0, %0\n"
    184		: "=&r" (sum)
    185		: "r" (saddr), "r" (daddr),
    186		  "r"(htonl(len)), "r"(htonl(proto)), "r"(sum)
    187		: "g2", "g3", "g4", "cc");
    188
    189	return csum_fold(sum);
    190}
    191
    192/* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
    193static inline __sum16 ip_compute_csum(const void *buff, int len)
    194{
    195	return csum_fold(csum_partial(buff, len, 0));
    196}
    197
    198#define HAVE_ARCH_CSUM_ADD
    199static inline __wsum csum_add(__wsum csum, __wsum addend)
    200{
    201	__asm__ __volatile__(
    202		"addcc   %0, %1, %0\n"
    203		"addx    %0, %%g0, %0"
    204		: "=r" (csum)
    205		: "r" (addend), "0" (csum));
    206
    207	return csum;
    208}
    209
    210#endif /* !(__SPARC_CHECKSUM_H) */