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 
42 unsigned int __csum_partial_copy_sparc_generic (const unsigned char *, unsigned char *);
43 
44 static inline __wsum
45 csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
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 %6, %%g7\n"
54 	: "=&r" (ret), "=&r" (d), "=&r" (l)
55 	: "0" (ret), "1" (d), "2" (l), "r" (sum)
56 	: "o2", "o3", "o4", "o5", "o7",
57 	  "g2", "g3", "g4", "g5", "g7",
58 	  "memory", "cc");
59 	return (__force __wsum)ret;
60 }
61 
62 static inline __wsum
63 csum_and_copy_from_user(const void __user *src, void *dst, int len,
64 			    __wsum sum, int *err)
65   {
66 	register unsigned long ret asm("o0") = (unsigned long)src;
67 	register char *d asm("o1") = dst;
68 	register int l asm("g1") = len;
69 	register __wsum s asm("g7") = sum;
70 
71 	if (unlikely(!access_ok(src, len))) {
72 		if (len)
73 			*err = -EFAULT;
74 		return sum;
75 	}
76 
77 	__asm__ __volatile__ (
78 	".section __ex_table,#alloc\n\t"
79 	".align 4\n\t"
80 	".word 1f,2\n\t"
81 	".previous\n"
82 	"1:\n\t"
83 	"call __csum_partial_copy_sparc_generic\n\t"
84 	" st %8, [%%sp + 64]\n"
85 	: "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
86 	: "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
87 	: "o2", "o3", "o4", "o5", "o7", "g2", "g3", "g4", "g5",
88 	  "cc", "memory");
89 	return (__force __wsum)ret;
90 }
91 
92 #define HAVE_CSUM_COPY_USER
93 
94 static inline __wsum
95 csum_and_copy_to_user(const void *src, void __user *dst, int len,
96 			  __wsum sum, int *err)
97 {
98 	if (!access_ok(dst, len)) {
99 		*err = -EFAULT;
100 		return sum;
101 	} else {
102 		register unsigned long ret asm("o0") = (unsigned long)src;
103 		register char __user *d asm("o1") = dst;
104 		register int l asm("g1") = len;
105 		register __wsum s asm("g7") = sum;
106 
107 		__asm__ __volatile__ (
108 		".section __ex_table,#alloc\n\t"
109 		".align 4\n\t"
110 		".word 1f,1\n\t"
111 		".previous\n"
112 		"1:\n\t"
113 		"call __csum_partial_copy_sparc_generic\n\t"
114 		" st %8, [%%sp + 64]\n"
115 		: "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
116 		: "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
117 		: "o2", "o3", "o4", "o5", "o7",
118 		  "g2", "g3", "g4", "g5",
119 		  "cc", "memory");
120 		return (__force __wsum)ret;
121 	}
122 }
123 
124 /* ihl is always 5 or greater, almost always is 5, and iph is word aligned
125  * the majority of the time.
126  */
127 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
128 {
129 	__sum16 sum;
130 
131 	/* Note: We must read %2 before we touch %0 for the first time,
132 	 *       because GCC can legitimately use the same register for
133 	 *       both operands.
134 	 */
135 	__asm__ __volatile__("sub\t%2, 4, %%g4\n\t"
136 			     "ld\t[%1 + 0x00], %0\n\t"
137 			     "ld\t[%1 + 0x04], %%g2\n\t"
138 			     "ld\t[%1 + 0x08], %%g3\n\t"
139 			     "addcc\t%%g2, %0, %0\n\t"
140 			     "addxcc\t%%g3, %0, %0\n\t"
141 			     "ld\t[%1 + 0x0c], %%g2\n\t"
142 			     "ld\t[%1 + 0x10], %%g3\n\t"
143 			     "addxcc\t%%g2, %0, %0\n\t"
144 			     "addx\t%0, %%g0, %0\n"
145 			     "1:\taddcc\t%%g3, %0, %0\n\t"
146 			     "add\t%1, 4, %1\n\t"
147 			     "addxcc\t%0, %%g0, %0\n\t"
148 			     "subcc\t%%g4, 1, %%g4\n\t"
149 			     "be,a\t2f\n\t"
150 			     "sll\t%0, 16, %%g2\n\t"
151 			     "b\t1b\n\t"
152 			     "ld\t[%1 + 0x10], %%g3\n"
153 			     "2:\taddcc\t%0, %%g2, %%g2\n\t"
154 			     "srl\t%%g2, 16, %0\n\t"
155 			     "addx\t%0, %%g0, %0\n\t"
156 			     "xnor\t%%g0, %0, %0"
157 			     : "=r" (sum), "=&r" (iph)
158 			     : "r" (ihl), "1" (iph)
159 			     : "g2", "g3", "g4", "cc", "memory");
160 	return sum;
161 }
162 
163 /* Fold a partial checksum without adding pseudo headers. */
164 static inline __sum16 csum_fold(__wsum sum)
165 {
166 	unsigned int tmp;
167 
168 	__asm__ __volatile__("addcc\t%0, %1, %1\n\t"
169 			     "srl\t%1, 16, %1\n\t"
170 			     "addx\t%1, %%g0, %1\n\t"
171 			     "xnor\t%%g0, %1, %0"
172 			     : "=&r" (sum), "=r" (tmp)
173 			     : "0" (sum), "1" ((__force u32)sum<<16)
174 			     : "cc");
175 	return (__force __sum16)sum;
176 }
177 
178 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
179 					__u32 len, __u8 proto,
180 					__wsum sum)
181 {
182 	__asm__ __volatile__("addcc\t%1, %0, %0\n\t"
183 			     "addxcc\t%2, %0, %0\n\t"
184 			     "addxcc\t%3, %0, %0\n\t"
185 			     "addx\t%0, %%g0, %0\n\t"
186 			     : "=r" (sum), "=r" (saddr)
187 			     : "r" (daddr), "r" (proto + len), "0" (sum),
188 			       "1" (saddr)
189 			     : "cc");
190 	return sum;
191 }
192 
193 /*
194  * computes the checksum of the TCP/UDP pseudo-header
195  * returns a 16-bit checksum, already complemented
196  */
197 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
198 					__u32 len, __u8 proto,
199 					__wsum sum)
200 {
201 	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
202 }
203 
204 #define _HAVE_ARCH_IPV6_CSUM
205 
206 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
207 				      const struct in6_addr *daddr,
208 				      __u32 len, __u8 proto, __wsum sum)
209 {
210 	__asm__ __volatile__ (
211 		"addcc	%3, %4, %%g4\n\t"
212 		"addxcc	%5, %%g4, %%g4\n\t"
213 		"ld	[%2 + 0x0c], %%g2\n\t"
214 		"ld	[%2 + 0x08], %%g3\n\t"
215 		"addxcc	%%g2, %%g4, %%g4\n\t"
216 		"ld	[%2 + 0x04], %%g2\n\t"
217 		"addxcc	%%g3, %%g4, %%g4\n\t"
218 		"ld	[%2 + 0x00], %%g3\n\t"
219 		"addxcc	%%g2, %%g4, %%g4\n\t"
220 		"ld	[%1 + 0x0c], %%g2\n\t"
221 		"addxcc	%%g3, %%g4, %%g4\n\t"
222 		"ld	[%1 + 0x08], %%g3\n\t"
223 		"addxcc	%%g2, %%g4, %%g4\n\t"
224 		"ld	[%1 + 0x04], %%g2\n\t"
225 		"addxcc	%%g3, %%g4, %%g4\n\t"
226 		"ld	[%1 + 0x00], %%g3\n\t"
227 		"addxcc	%%g2, %%g4, %%g4\n\t"
228 		"addxcc	%%g3, %%g4, %0\n\t"
229 		"addx	0, %0, %0\n"
230 		: "=&r" (sum)
231 		: "r" (saddr), "r" (daddr),
232 		  "r"(htonl(len)), "r"(htonl(proto)), "r"(sum)
233 		: "g2", "g3", "g4", "cc");
234 
235 	return csum_fold(sum);
236 }
237 
238 /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
239 static inline __sum16 ip_compute_csum(const void *buff, int len)
240 {
241 	return csum_fold(csum_partial(buff, len, 0));
242 }
243 
244 #define HAVE_ARCH_CSUM_ADD
245 static inline __wsum csum_add(__wsum csum, __wsum addend)
246 {
247 	__asm__ __volatile__(
248 		"addcc   %0, %1, %0\n"
249 		"addx    %0, %%g0, %0"
250 		: "=r" (csum)
251 		: "r" (addend), "0" (csum));
252 
253 	return csum;
254 }
255 
256 #endif /* !(__SPARC_CHECKSUM_H) */
257