11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #ident "%Z%%M% %I% %E% SMI"
28
29 #include <sys/asm_linkage.h>
30
31 #if defined(lint)
32 #include <sys/types.h>
33 #endif /* lint */
34
35 /*
36 * ip_ocsum(address, halfword_count, sum)
37 * Do a 16 bit one's complement sum of a given number of (16-bit)
38 * halfwords. The halfword pointer must not be odd.
39 * %o0 address; %o1 count; %o2 sum accumulator; %o4 temp
40 * %g2 and %g3 used in main loop
41 *
42 * (from @(#)ocsum.s 1.3 89/02/24 SMI)
43 *
44 */
45
46 #if defined(lint)
47
48 /* ARGSUSED */
49 unsigned int
50 ip_ocsum(u_short *address, int halfword_count, unsigned int sum)
51 { return (0); }
52
53 #else /* lint */
54
55 ENTRY(ip_ocsum)
56 cmp %o1, 31 ! less than 62 bytes?
57 bl,a .dohw ! just do halfwords
58 tst %o1 ! delay slot, test count
59
60 btst 31, %o0 ! (delay slot)
61 bz 2f ! if 32 byte aligned, skip
62 nop
63
64 !
65 ! Do first halfwords until 32-byte aligned
66 !
67 1:
68 lduh [%o0], %g2 ! read data
69 add %o0, 2, %o0 ! increment address
70 add %o2, %g2, %o2 ! add to accumulator, don't need carry yet
71 btst 31, %o0 ! 32 byte aligned?
72 bnz 1b
73 sub %o1, 1, %o1 ! decrement count
74 !
107 3:
108 add %o0, 2, %o0 ! increment address
109 addcc %o2, %g2, %o2 ! add to accumulator
110 addxcc %o2, 0, %o2 ! if carry, add it in
111 subcc %o1, 1, %o1 ! decrement count
112 .dohw:
113 bg,a 3b ! more to do?
114 lduh [%o0], %g2 ! read data
115
116 !
117 ! at this point the 32-bit accumulator
118 ! has the result that needs to be returned in 16-bits
119 !
120 sll %o2, 16, %o4 ! put low halfword in high halfword %o4
121 addcc %o4, %o2, %o2 ! add the 2 halfwords in high %o2, set carry
122 srl %o2, 16, %o2 ! shift to low halfword
123 retl ! return
124 addxcc %o2, 0, %o0 ! add in carry if any. result in %o0
125 SET_SIZE(ip_ocsum)
126
127 #endif /* lint */
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11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #ident "%Z%%M% %I% %E% SMI"
28
29 #include <sys/asm_linkage.h>
30
31 /*
32 * ip_ocsum(address, halfword_count, sum)
33 * Do a 16 bit one's complement sum of a given number of (16-bit)
34 * halfwords. The halfword pointer must not be odd.
35 * %o0 address; %o1 count; %o2 sum accumulator; %o4 temp
36 * %g2 and %g3 used in main loop
37 *
38 * (from @(#)ocsum.s 1.3 89/02/24 SMI)
39 *
40 */
41
42 ENTRY(ip_ocsum)
43 cmp %o1, 31 ! less than 62 bytes?
44 bl,a .dohw ! just do halfwords
45 tst %o1 ! delay slot, test count
46
47 btst 31, %o0 ! (delay slot)
48 bz 2f ! if 32 byte aligned, skip
49 nop
50
51 !
52 ! Do first halfwords until 32-byte aligned
53 !
54 1:
55 lduh [%o0], %g2 ! read data
56 add %o0, 2, %o0 ! increment address
57 add %o2, %g2, %o2 ! add to accumulator, don't need carry yet
58 btst 31, %o0 ! 32 byte aligned?
59 bnz 1b
60 sub %o1, 1, %o1 ! decrement count
61 !
94 3:
95 add %o0, 2, %o0 ! increment address
96 addcc %o2, %g2, %o2 ! add to accumulator
97 addxcc %o2, 0, %o2 ! if carry, add it in
98 subcc %o1, 1, %o1 ! decrement count
99 .dohw:
100 bg,a 3b ! more to do?
101 lduh [%o0], %g2 ! read data
102
103 !
104 ! at this point the 32-bit accumulator
105 ! has the result that needs to be returned in 16-bits
106 !
107 sll %o2, 16, %o4 ! put low halfword in high halfword %o4
108 addcc %o4, %o2, %o2 ! add the 2 halfwords in high %o2, set carry
109 srl %o2, 16, %o2 ! shift to low halfword
110 retl ! return
111 addxcc %o2, 0, %o0 ! add in carry if any. result in %o0
112 SET_SIZE(ip_ocsum)
113
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