2 * arch/alpha/lib/csum_ipv6_magic.S
3 * Contributed by Richard Henderson <rth@tamu.edu>
5 * unsigned short csum_ipv6_magic(struct in6_addr *saddr,
6 * struct in6_addr *daddr,
8 * unsigned short proto,
11 * Misalignment handling (which costs 16 instructions / 8 cycles)
12 * added by Ivan Kokshaysky <ink@jurassic.park.msu.ru>
15 #include <asm/export.h>
16 .globl csum_ipv6_magic
23 ldq_u $0,0($16) # e0 : load src & dst addr words
24 zapnot $20,15,$20 # .. e1 : zero extend incoming csum
25 extqh $18,1,$4 # e0 : byte swap len & proto while we wait
26 ldq_u $21,7($16) # .. e1 : handle misalignment
29 ldq_u $1,8($16) # .. e1 :
31 ldq_u $22,15($16) # .. e1 :
33 extbl $18,3,$18 # e0 :
34 ldq_u $2,0($17) # .. e1 :
36 ldq_u $23,7($17) # .. e1 :
38 extql $0,$16,$0 # e0 :
39 ldq_u $3,8($17) # .. e1 :
40 extqh $21,$16,$21 # e0 :
41 ldq_u $24,15($17) # .. e1 :
44 or $0,$21,$0 # .. e1 : 1st src word complete
45 extql $1,$16,$1 # e0 :
46 addq $20,$0,$20 # .. e1 : begin summing the words
48 extqh $22,$16,$22 # e0 :
49 cmpult $20,$0,$0 # .. e1 :
51 or $1,$22,$1 # .. e1 : 2nd src word complete
53 extql $2,$17,$2 # e0 :
54 or $4,$18,$18 # .. e1 :
55 extqh $23,$17,$23 # e0 :
58 extql $3,$17,$3 # e0 :
59 or $2,$23,$2 # .. e1 : 1st dst word complete
60 extqh $24,$17,$24 # e0 :
61 or $18,$5,$18 # .. e1 : len complete
64 or $3,$24,$3 # .. e1 : 2nd dst word complete
65 extbl $19,1,$19 # e0 :
66 addq $20,$1,$20 # .. e1 :
69 cmpult $20,$1,$1 # .. e1 :
73 sra $19,32,$19 # e0 : proto complete
74 addq $20,$2,$20 # .. e1 :
75 cmpult $20,$2,$2 # e0 :
76 addq $20,$3,$20 # .. e1 :
78 cmpult $20,$3,$3 # e0 :
79 addq $20,$18,$20 # .. e1 :
80 cmpult $20,$18,$18 # e0 :
81 addq $20,$19,$20 # .. e1 :
83 cmpult $20,$19,$19 # e0 :
84 addq $0,$1,$0 # .. e1 : merge the carries back into the csum
86 addq $18,$19,$18 # .. e1 :
89 addq $20,$18,$20 # .. e1 :
93 extwl $0,2,$2 # e0 : begin folding the 64-bit value
94 zapnot $0,3,$3 # .. e1 :
96 addq $2,$3,$3 # .. e1 :
99 addq $3,$1,$3 # .. e1 :
103 extwl $0,2,$1 # e0 : fold 18-bit value
104 zapnot $0,3,$0 # .. e1 :
108 extwl $0,2,$1 # e0 : fold 17-bit value
109 zapnot $0,3,$0 # .. e1 :
111 not $0,$0 # .. e1 : and complement.
113 zapnot $0,3,$0 # e0 :
117 EXPORT_SYMBOL(csum_ipv6_magic)