checksum_32.h

  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) */