1/* $Id: checksum.h,v 1.1.1.1 2008/10/15 03:29:17 james26_jang Exp $ */
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 <asm/uaccess.h>
21#include <asm/cprefix.h>
22
23/* computes the checksum of a memory block at buff, length len,
24 * and adds in "sum" (32-bit)
25 *
26 * returns a 32-bit number suitable for feeding into itself
27 * or csum_tcpudp_magic
28 *
29 * this function must be called with even lengths, except
30 * for the last fragment, which may be odd
31 *
32 * it's best to have buff aligned on a 32-bit boundary
33 */
34extern unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
35
36/* the same as csum_partial, but copies from fs:src while it
37 * checksums
38 *
39 * here even more important to align src and dst on a 32-bit (or even
40 * better 64-bit) boundary
41 */
42
43#define csum_partial_copy(src, dst, len, sum) \
44 		       csum_partial_copy_nocheck(src,dst,len,sum)
45#define csum_partial_copy_fromuser(s, d, l, w)  \
46                         csum_partial_copy((char *) (s), (d), (l), (w))
47
48extern unsigned int __csum_partial_copy_sparc_generic (const char *, char *);
49
50extern __inline__ unsigned int
51csum_partial_copy_nocheck (const char *src, char *dst, int len,
52			   unsigned int sum)
53{
54	register unsigned int ret asm("o0") = (unsigned int)src;
55	register char *d asm("o1") = dst;
56	register int l asm("g1") = len;
57
58	__asm__ __volatile__ (
59		"call " C_LABEL_STR(__csum_partial_copy_sparc_generic) "\n\t"
60		" mov %4, %%g7\n"
61	: "=r" (ret) : "0" (ret), "r" (d), "r" (l), "r" (sum) :
62	"o1", "o2", "o3", "o4", "o5", "o7", "g1", "g2", "g3", "g4", "g5", "g7");
63	return ret;
64}
65
66extern __inline__ unsigned int
67csum_partial_copy_from_user(const char *src, char *dst, int len,
68			    unsigned int sum, int *err)
69  {
70	if (!access_ok (VERIFY_READ, src, len)) {
71		*err = -EFAULT;
72		memset (dst, 0, len);
73		return sum;
74	} else {
75		register unsigned int ret asm("o0") = (unsigned int)src;
76		register char *d asm("o1") = dst;
77		register int l asm("g1") = len;
78		register unsigned int s asm("g7") = sum;
79
80		__asm__ __volatile__ (
81		".section __ex_table,#alloc\n\t"
82		".align 4\n\t"
83		".word 1f,2\n\t"
84		".previous\n"
85		"1:\n\t"
86		"call " C_LABEL_STR(__csum_partial_copy_sparc_generic) "\n\t"
87		" st %5, [%%sp + 64]\n"
88		: "=r" (ret) : "0" (ret), "r" (d), "r" (l), "r" (s), "r" (err) :
89		"o1", "o2", "o3", "o4", "o5", "o7", "g1", "g2", "g3", "g4", "g5", "g7");
90		return ret;
91	}
92  }
93
94extern __inline__ unsigned int
95csum_partial_copy_to_user(const char *src, char *dst, int len,
96			  unsigned int sum, int *err)
97{
98	if (!access_ok (VERIFY_WRITE, dst, len)) {
99		*err = -EFAULT;
100		return sum;
101	} else {
102		register unsigned int ret asm("o0") = (unsigned int)src;
103		register char *d asm("o1") = dst;
104		register int l asm("g1") = len;
105		register unsigned int 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 " C_LABEL_STR(__csum_partial_copy_sparc_generic) "\n\t"
114		" st %5, [%%sp + 64]\n"
115		: "=r" (ret) : "0" (ret), "r" (d), "r" (l), "r" (s), "r" (err) :
116		"o1", "o2", "o3", "o4", "o5", "o7", "g1", "g2", "g3", "g4", "g5", "g7");
117		return ret;
118	}
119}
120
121#define HAVE_CSUM_COPY_USER
122#define csum_and_copy_to_user csum_partial_copy_to_user
123
124/* ihl is always 5 or greater, almost always is 5, and iph is word aligned
125 * the majority of the time.
126 */
127extern __inline__ unsigned short ip_fast_csum(__const__ unsigned char *iph,
128					      unsigned int ihl)
129{
130	unsigned short sum;
131
132	/* Note: We must read %2 before we touch %0 for the first time,
133	 *       because GCC can legitimately use the same register for
134	 *       both operands.
135	 */
136	__asm__ __volatile__("sub\t%2, 4, %%g4\n\t"
137			     "ld\t[%1 + 0x00], %0\n\t"
138			     "ld\t[%1 + 0x04], %%g2\n\t"
139			     "ld\t[%1 + 0x08], %%g3\n\t"
140			     "addcc\t%%g2, %0, %0\n\t"
141			     "addxcc\t%%g3, %0, %0\n\t"
142			     "ld\t[%1 + 0x0c], %%g2\n\t"
143			     "ld\t[%1 + 0x10], %%g3\n\t"
144			     "addxcc\t%%g2, %0, %0\n\t"
145			     "addx\t%0, %%g0, %0\n"
146			     "1:\taddcc\t%%g3, %0, %0\n\t"
147			     "add\t%1, 4, %1\n\t"
148			     "addxcc\t%0, %%g0, %0\n\t"
149			     "subcc\t%%g4, 1, %%g4\n\t"
150			     "be,a\t2f\n\t"
151			     "sll\t%0, 16, %%g2\n\t"
152			     "b\t1b\n\t"
153			     "ld\t[%1 + 0x10], %%g3\n"
154			     "2:\taddcc\t%0, %%g2, %%g2\n\t"
155			     "srl\t%%g2, 16, %0\n\t"
156			     "addx\t%0, %%g0, %0\n\t"
157			     "xnor\t%%g0, %0, %0"
158			     : "=r" (sum), "=&r" (iph)
159			     : "r" (ihl), "1" (iph)
160			     : "g2", "g3", "g4", "cc");
161	return sum;
162}
163
164/* Fold a partial checksum without adding pseudo headers. */
165extern __inline__ unsigned int csum_fold(unsigned int sum)
166{
167	unsigned int tmp;
168
169	__asm__ __volatile__("addcc\t%0, %1, %1\n\t"
170			     "srl\t%1, 16, %1\n\t"
171			     "addx\t%1, %%g0, %1\n\t"
172			     "xnor\t%%g0, %1, %0"
173			     : "=&r" (sum), "=r" (tmp)
174			     : "0" (sum), "1" (sum<<16)
175			     : "cc");
176	return sum;
177}
178
179extern __inline__ unsigned long csum_tcpudp_nofold(unsigned long saddr,
180						   unsigned long daddr,
181						   unsigned int len,
182						   unsigned short proto,
183						   unsigned int sum)
184{
185	__asm__ __volatile__("addcc\t%1, %0, %0\n\t"
186			     "addxcc\t%2, %0, %0\n\t"
187			     "addxcc\t%3, %0, %0\n\t"
188			     "addx\t%0, %%g0, %0\n\t"
189			     : "=r" (sum), "=r" (saddr)
190			     : "r" (daddr), "r" ((proto<<16)+len), "0" (sum),
191			       "1" (saddr)
192			     : "cc");
193	return sum;
194}
195
196/*
197 * computes the checksum of the TCP/UDP pseudo-header
198 * returns a 16-bit checksum, already complemented
199 */
200static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
201						   unsigned long daddr,
202						   unsigned short len,
203						   unsigned short proto,
204						   unsigned int sum)
205{
206	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
207}
208
209#define _HAVE_ARCH_IPV6_CSUM
210
211static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
212						     struct in6_addr *daddr,
213						     __u32 len,
214						     unsigned short proto,
215						     unsigned int sum)
216{
217	__asm__ __volatile__ (
218		"addcc	%3, %4, %%g4\n\t"
219		"addxcc	%5, %%g4, %%g4\n\t"
220		"ld	[%2 + 0x0c], %%g2\n\t"
221		"ld	[%2 + 0x08], %%g3\n\t"
222		"addxcc	%%g2, %%g4, %%g4\n\t"
223		"ld	[%2 + 0x04], %%g2\n\t"
224		"addxcc	%%g3, %%g4, %%g4\n\t"
225		"ld	[%2 + 0x00], %%g3\n\t"
226		"addxcc	%%g2, %%g4, %%g4\n\t"
227		"ld	[%1 + 0x0c], %%g2\n\t"
228		"addxcc	%%g3, %%g4, %%g4\n\t"
229		"ld	[%1 + 0x08], %%g3\n\t"
230		"addxcc	%%g2, %%g4, %%g4\n\t"
231		"ld	[%1 + 0x04], %%g2\n\t"
232		"addxcc	%%g3, %%g4, %%g4\n\t"
233		"ld	[%1 + 0x00], %%g3\n\t"
234		"addxcc	%%g2, %%g4, %%g4\n\t"
235		"addxcc	%%g3, %%g4, %0\n\t"
236		"addx	0, %0, %0\n"
237		: "=&r" (sum)
238		: "r" (saddr), "r" (daddr),
239		  "r"(htonl(len)), "r"(htonl(proto)), "r"(sum)
240		: "g2", "g3", "g4", "cc");
241
242	return csum_fold(sum);
243}
244
245/* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
246extern __inline__ unsigned short ip_compute_csum(unsigned char * buff, int len)
247{
248	return csum_fold(csum_partial(buff, len, 0));
249}
250
251#endif /* !(__SPARC_CHECKSUM_H) */
252