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-rw-r--r--arch/alpha/lib/csum_ipv6_magic.S118
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/alpha/lib/csum_ipv6_magic.S b/arch/alpha/lib/csum_ipv6_magic.S
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+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * arch/alpha/lib/csum_ipv6_magic.S
+ * Contributed by Richard Henderson <rth@tamu.edu>
+ *
+ * unsigned short csum_ipv6_magic(struct in6_addr *saddr,
+ * struct in6_addr *daddr,
+ * __u32 len,
+ * unsigned short proto,
+ * unsigned int csum);
+ *
+ * Misalignment handling (which costs 16 instructions / 8 cycles)
+ * added by Ivan Kokshaysky <ink@jurassic.park.msu.ru>
+ */
+
+#include <asm/export.h>
+ .globl csum_ipv6_magic
+ .align 4
+ .ent csum_ipv6_magic
+ .frame $30,0,$26,0
+csum_ipv6_magic:
+ .prologue 0
+
+ ldq_u $0,0($16) # e0 : load src & dst addr words
+ zapnot $20,15,$20 # .. e1 : zero extend incoming csum
+ extqh $18,1,$4 # e0 : byte swap len & proto while we wait
+ ldq_u $21,7($16) # .. e1 : handle misalignment
+
+ extbl $18,1,$5 # e0 :
+ ldq_u $1,8($16) # .. e1 :
+ extbl $18,2,$6 # e0 :
+ ldq_u $22,15($16) # .. e1 :
+
+ extbl $18,3,$18 # e0 :
+ ldq_u $2,0($17) # .. e1 :
+ sra $4,32,$4 # e0 :
+ ldq_u $23,7($17) # .. e1 :
+
+ extql $0,$16,$0 # e0 :
+ ldq_u $3,8($17) # .. e1 :
+ extqh $21,$16,$21 # e0 :
+ ldq_u $24,15($17) # .. e1 :
+
+ sll $5,16,$5 # e0 :
+ or $0,$21,$0 # .. e1 : 1st src word complete
+ extql $1,$16,$1 # e0 :
+ addq $20,$0,$20 # .. e1 : begin summing the words
+
+ extqh $22,$16,$22 # e0 :
+ cmpult $20,$0,$0 # .. e1 :
+ sll $6,8,$6 # e0 :
+ or $1,$22,$1 # .. e1 : 2nd src word complete
+
+ extql $2,$17,$2 # e0 :
+ or $4,$18,$18 # .. e1 :
+ extqh $23,$17,$23 # e0 :
+ or $5,$6,$5 # .. e1 :
+
+ extql $3,$17,$3 # e0 :
+ or $2,$23,$2 # .. e1 : 1st dst word complete
+ extqh $24,$17,$24 # e0 :
+ or $18,$5,$18 # .. e1 : len complete
+
+ extwh $19,7,$7 # e0 :
+ or $3,$24,$3 # .. e1 : 2nd dst word complete
+ extbl $19,1,$19 # e0 :
+ addq $20,$1,$20 # .. e1 :
+
+ or $19,$7,$19 # e0 :
+ cmpult $20,$1,$1 # .. e1 :
+ sll $19,48,$19 # e0 :
+ nop # .. e0 :
+
+ sra $19,32,$19 # e0 : proto complete
+ addq $20,$2,$20 # .. e1 :
+ cmpult $20,$2,$2 # e0 :
+ addq $20,$3,$20 # .. e1 :
+
+ cmpult $20,$3,$3 # e0 :
+ addq $20,$18,$20 # .. e1 :
+ cmpult $20,$18,$18 # e0 :
+ addq $20,$19,$20 # .. e1 :
+
+ cmpult $20,$19,$19 # e0 :
+ addq $0,$1,$0 # .. e1 : merge the carries back into the csum
+ addq $2,$3,$2 # e0 :
+ addq $18,$19,$18 # .. e1 :
+
+ addq $0,$2,$0 # e0 :
+ addq $20,$18,$20 # .. e1 :
+ addq $0,$20,$0 # e0 :
+ unop # :
+
+ extwl $0,2,$2 # e0 : begin folding the 64-bit value
+ zapnot $0,3,$3 # .. e1 :
+ extwl $0,4,$1 # e0 :
+ addq $2,$3,$3 # .. e1 :
+
+ extwl $0,6,$0 # e0 :
+ addq $3,$1,$3 # .. e1 :
+ addq $0,$3,$0 # e0 :
+ unop # :
+
+ extwl $0,2,$1 # e0 : fold 18-bit value
+ zapnot $0,3,$0 # .. e1 :
+ addq $0,$1,$0 # e0 :
+ unop # :
+
+ extwl $0,2,$1 # e0 : fold 17-bit value
+ zapnot $0,3,$0 # .. e1 :
+ addq $0,$1,$0 # e0 :
+ not $0,$0 # .. e1 : and complement.
+
+ zapnot $0,3,$0 # e0 :
+ ret # .. e1 :
+
+ .end csum_ipv6_magic
+ EXPORT_SYMBOL(csum_ipv6_magic)