diff options
| author | Ivan Kokshaysky <ink@jurassic.park.msu.ru> | 2007-06-23 17:16:35 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-06-24 08:59:11 -0700 |
| commit | 58ed2f9c75b719da4f494f24ed2d56d45f5b4959 (patch) | |
| tree | 6ecb60cf2d7b18da36fd29f2a6bd03d15a8cfefb /arch/alpha/lib/csum_ipv6_magic.S | |
| parent | 653d4876b730fedca8473481863cf700245e3582 (diff) | |
alpha: fix alignment problem in csum_ipv6_magic()
Hopefully this fixes http://bugzilla.kernel.org/show_bug.cgi?id=8635
The struct in6_addr passed to csum_ipv6_magic() is 4 byte aligned, so we
can't use the regular 64-bit loads. Since the cost of handling of 4 byte
and 1 byte aligned 64-bit data is roughly the same, this code can cope with
any src/dst [mis]alignment.
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Dustin Marquess <jailbird@alcatraz.fdf.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/alpha/lib/csum_ipv6_magic.S')
| -rw-r--r-- | arch/alpha/lib/csum_ipv6_magic.S | 51 |
1 files changed, 37 insertions, 14 deletions
diff --git a/arch/alpha/lib/csum_ipv6_magic.S b/arch/alpha/lib/csum_ipv6_magic.S index e09748dbf2e..2c2acb96deb 100644 --- a/arch/alpha/lib/csum_ipv6_magic.S +++ b/arch/alpha/lib/csum_ipv6_magic.S @@ -7,6 +7,9 @@ * __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> */ .globl csum_ipv6_magic @@ -16,37 +19,57 @@ csum_ipv6_magic: .prologue 0 - ldq $0,0($16) # e0 : load src & dst addr words + 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 $1,8($16) # .. e1 : + ldq_u $21,7($16) # .. e1 : handle misalignment extbl $18,1,$5 # e0 : - ldq $2,0($17) # .. e1 : + ldq_u $1,8($16) # .. e1 : extbl $18,2,$6 # e0 : - ldq $3,8($17) # .. e1 : + 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 - sll $6,8,$6 # e0 : + extqh $22,$16,$22 # e0 : cmpult $20,$0,$0 # .. e1 : - extwh $19,7,$7 # e0 : - or $4,$18,$18 # .. e1 : + sll $6,8,$6 # e0 : + or $1,$22,$1 # .. e1 : 2nd src word complete - extbl $19,1,$19 # e0 : + extql $2,$17,$2 # e0 : + or $4,$18,$18 # .. e1 : + extqh $23,$17,$23 # e0 : or $5,$6,$5 # .. e1 : - or $18,$5,$18 # e0 : len complete - or $19,$7,$19 # .. e1 : - sll $19,48,$19 # e0 : + 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 : - sra $19,32,$19 # e0 : proto complete + + or $19,$7,$19 # e0 : cmpult $20,$1,$1 # .. e1 : + sll $19,48,$19 # e0 : + nop # .. 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 : @@ -84,7 +107,7 @@ csum_ipv6_magic: 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. + not $0,$0 # .. e1 : and complement. zapnot $0,3,$0 # e0 : ret # .. e1 : |