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source: rtems/cpukit/libnetworking/netinet/in_cksum_sparc.h @ c6cb9ba

5

Last change on this file since c6cb9ba was c6cb9ba, checked in by Sebastian Huber <sebastian.huber@…>, on 04/22/16 at 06:52:41
network: Delete unused in4_cksum()
Property mode set to `100644`
File size: 9.0 KB

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1	/* $NetBSD: in_cksum.c,v 1.12.10.4 2005/12/11 10:28:36 christos Exp $ */
2
3	/*
4	* Copyright (c) 1995 Matthew R. Green.
5	* Copyright (c) 1992, 1993
6	* The Regents of the University of California. All rights reserved.
7	*
8	* All advertising materials mentioning features or use of this software
9	* must display the following acknowledgement:
10	* This product includes software developed by the University of
11	* California, and it's contributors.
12	*
13	* Redistribution and use in source and binary forms, with or without
14	* modification, are permitted provided that the following conditions
15	* are met:
16	* 1. Redistributions of source code must retain the above copyright
17	* notice, this list of conditions and the following disclaimer.
18	* 2. Redistributions in binary form must reproduce the above copyright
19	* notice, this list of conditions and the following disclaimer in the
20	* documentation and/or other materials provided with the distribution.
21	* 3. Neither the name of the University nor the names of its contributors
22	* may be used to endorse or promote products derived from this software
23	* without specific prior written permission.
24	*
25	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35	* SUCH DAMAGE.
36	*
37	* @(#)in_cksum.c 8.1 (Berkeley) 6/11/93
38	*/
39
40	/*
41	* Copyright (c) 1995 Zubin Dittia.
42	* Copyright (c) 1994, 1998 Charles M. Hannum.
43	*
44	* All advertising materials mentioning features or use of this software
45	* must display the following acknowledgement:
46	* This product includes software developed by the University of
47	* California, and it's contributors.
48	*
49	* Redistribution and use in source and binary forms, with or without
50	* modification, are permitted provided that the following conditions
51	* are met:
52	* 1. Redistributions of source code must retain the above copyright
53	* notice, this list of conditions and the following disclaimer.
54	* 2. Redistributions in binary form must reproduce the above copyright
55	* notice, this list of conditions and the following disclaimer in the
56	* documentation and/or other materials provided with the distribution.
57	* 3. All advertising materials mentioning features or use of this software
58	* must display the following acknowledgement:
59	* This product includes software developed by the University of
60	* California, Berkeley and its contributors.
61	* 4. Neither the name of the University nor the names of its contributors
62	* may be used to endorse or promote products derived from this software
63	* without specific prior written permission.
64	*
65	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
66	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
67	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
68	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
69	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
70	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
71	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
72	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
73	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
74	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
75	* SUCH DAMAGE.
76	*
77	* @(#)in_cksum.c 8.1 (Berkeley) 6/11/93
78	*/
79
80	#include <sys/cdefs.h>
81	#include <sys/param.h>
82	#include <sys/systm.h>
83	#include <sys/mbuf.h>
84	#include <netinet/in.h>
85	#include <netinet/in_systm.h>
86	#include <netinet/ip.h>
87	#include <netinet/ip_var.h>
88
89	/*
90	* Checksum routine for Internet Protocol family headers.
91	*
92	* This routine is very heavily used in the network
93	* code and should be modified for each CPU to be as fast as possible.
94	*
95	* SPARC version.
96	*/
97
98	/*
99	* The checksum computation code here is significantly faster than its
100	* vanilla C counterpart (by significantly, I mean 2-3 times faster if
101	* the data is in cache, and 1.5-2 times faster if the data is not in
102	* cache).
103	* We optimize on three fronts:
104	* 1. By using the add-with-carry (addxcc) instruction, we can use
105	* 32-bit operations instead of 16-bit operations.
106	* 2. By unrolling the main loop to reduce branch overheads.
107	* 3. By doing a sequence of load,load,add,add,load,load,add,add,
108	* we can avoid the extra stall cycle which is incurred if the
109	* instruction immediately following a load tries to use the
110	* target register of the load.
111	* Another possible optimization is to replace a pair of 32-bit loads
112	* with a single 64-bit load (ldd) instruction, but I found that although
113	* this improves performance somewhat on Sun4c machines, it actually
114	* reduces performance considerably on Sun4m machines (I don't know why).
115	* So I chose to leave it out.
116	*
117	* Zubin Dittia (zubin@dworkin.wustl.edu)
118	*/
119
120	#define Asm __asm __volatile
121	#define ADD64 Asm(" ld [%4+ 0],%1; ld [%4+ 4],%2; \
122	addcc %0,%1,%0; addxcc %0,%2,%0; \
123	ld [%4+ 8],%1; ld [%4+12],%2; \
124	addxcc %0,%1,%0; addxcc %0,%2,%0; \
125	ld [%4+16],%1; ld [%4+20],%2; \
126	addxcc %0,%1,%0; addxcc %0,%2,%0; \
127	ld [%4+24],%1; ld [%4+28],%2; \
128	addxcc %0,%1,%0; addxcc %0,%2,%0; \
129	ld [%4+32],%1; ld [%4+36],%2; \
130	addxcc %0,%1,%0; addxcc %0,%2,%0; \
131	ld [%4+40],%1; ld [%4+44],%2; \
132	addxcc %0,%1,%0; addxcc %0,%2,%0; \
133	ld [%4+48],%1; ld [%4+52],%2; \
134	addxcc %0,%1,%0; addxcc %0,%2,%0; \
135	ld [%4+56],%1; ld [%4+60],%2; \
136	addxcc %0,%1,%0; addxcc %0,%2,%0; \
137	addxcc %0,0,%0" \
138	: "=r" (sum), "=&r" (tmp1), "=&r" (tmp2)\
139	: "0" (sum), "r" (w))
140	#define ADD32 Asm(" ld [%4+ 0],%1; ld [%4+ 4],%2; \
141	addcc %0,%1,%0; addxcc %0,%2,%0; \
142	ld [%4+ 8],%1; ld [%4+12],%2; \
143	addxcc %0,%1,%0; addxcc %0,%2,%0; \
144	ld [%4+16],%1; ld [%4+20],%2; \
145	addxcc %0,%1,%0; addxcc %0,%2,%0; \
146	ld [%4+24],%1; ld [%4+28],%2; \
147	addxcc %0,%1,%0; addxcc %0,%2,%0; \
148	addxcc %0,0,%0" \
149	: "=r" (sum), "=&r" (tmp1), "=&r" (tmp2)\
150	: "0" (sum), "r" (w))
151	#define ADD16 Asm(" ld [%4+ 0],%1; ld [%4+ 4],%2; \
152	addcc %0,%1,%0; addxcc %0,%2,%0; \
153	ld [%4+ 8],%1; ld [%4+12],%2; \
154	addxcc %0,%1,%0; addxcc %0,%2,%0; \
155	addxcc %0,0,%0" \
156	: "=r" (sum), "=&r" (tmp1), "=&r" (tmp2)\
157	: "0" (sum), "r" (w))
158	#define ADD8 Asm(" ld [%4+ 0],%1; ld [%4+ 4],%2; \
159	addcc %0,%1,%0; addxcc %0,%2,%0; \
160	addxcc %0,0,%0" \
161	: "=r" (sum), "=&r" (tmp1), "=&r" (tmp2)\
162	: "0" (sum), "r" (w))
163	#define ADD4 Asm(" ld [%3+ 0],%1; \
164	addcc %0,%1,%0; \
165	addxcc %0,0,%0" \
166	: "=r" (sum), "=&r" (tmp1) \
167	: "0" (sum), "r" (w))
168
169	#define REDUCE {sum = (sum & 0xffff) + (sum >> 16);}
170	#define ADDCARRY {if (sum > 0xffff) sum -= 0xffff;}
171	#define ROL {sum = sum << 8;} /* depends on recent REDUCE */
172	#define ADDBYTE {ROL; sum += *w; byte_swapped ^= 1;}
173	#define ADDSHORT {sum += (u_short )w;}
174	#define ADVANCE(n) {w += n; mlen -= n;}
175
176	static __inline__ int
177	in_cksum_internal(struct mbuf *m, int off, int len, u_int sum)
178	{
179	u_char *w;
180	int mlen = 0;
181	int byte_swapped = 0;
182
183	/*
184	* Declare two temporary registers for use by the asm code. We
185	* allow the compiler to pick which specific machine registers to
186	* use, instead of hard-coding this in the asm code above.
187	*/
188	u_int tmp1, tmp2;
189
190	for (; m && len; m = m->m_next) {
191	if (m->m_len == 0)
192	continue;
193	w = mtod(m, u_char *) + off;
194	mlen = m->m_len - off;
195	off = 0;
196	if (len < mlen)
197	mlen = len;
198	len -= mlen;
199
200	/*
201	* Ensure that we're aligned on a word boundary here so
202	* that we can do 32 bit operations below.
203	*/
204	if ((3 & (long)w) != 0) {
205	REDUCE;
206	if ((1 & (long)w) != 0 && mlen >= 1) {
207	ADDBYTE;
208	ADVANCE(1);
209	}
210	if ((2 & (long)w) != 0 && mlen >= 2) {
211	ADDSHORT;
212	ADVANCE(2);
213	}
214	}
215
216	/*
217	* Do as many 32 bit operations as possible using the
218	* 64/32/16/8/4 macro's above, using as many as possible of
219	* these.
220	*/
221	while (mlen >= 64) {
222	ADD64;
223	ADVANCE(64);
224	}
225	if (mlen >= 32) {
226	ADD32;
227	ADVANCE(32);
228	}
229	if (mlen >= 16) {
230	ADD16;
231	ADVANCE(16);
232	}
233	if (mlen >= 8) {
234	ADD8;
235	ADVANCE(8);
236	}
237	if (mlen >= 4) {
238	ADD4;
239	ADVANCE(4)
240	}
241	if (mlen == 0)
242	continue;
243
244	REDUCE;
245	if (mlen >= 2) {
246	ADDSHORT;
247	ADVANCE(2);
248	}
249	if (mlen == 1) {
250	ADDBYTE;
251	}
252	}
253	if (byte_swapped) {
254	REDUCE;
255	ROL;
256	}
257	REDUCE;
258	ADDCARRY;
259
260	return (0xffff ^ sum);
261	}
262
263	int
264	in_cksum(struct mbuf *m, int len)
265	{
266
267	return (in_cksum_internal(m, 0, len, 0));
268	}

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