* [patch] alpha: fix alignment problem in csum_ipv6_magic()
@ 2007-06-16 21:20 Ivan Kokshaysky
2007-06-21 23:35 ` Andrew Morton
0 siblings, 1 reply; 4+ messages in thread
From: Ivan Kokshaysky @ 2007-06-16 21:20 UTC (permalink / raw)
To: Andrew Morton, Richard Henderson; +Cc: linux-kernel
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>
Ivan.
--- 2.6.22-rc4/arch/alpha/lib/ev6-csum_ipv6_magic.S Sun Feb 4 21:44:54 2007
+++ linux/arch/alpha/lib/ev6-csum_ipv6_magic.S Sun Jun 17 00:41:53 2007
@@ -46,6 +46,10 @@
* add the 3 low ushorts together, generating a uint
* a final add of the 2 lower ushorts
* truncating the result.
+ *
+ * Misalignment handling added by Ivan Kokshaysky <ink@jurassic.park.msu.ru>
+ * The cost is 16 instructions (~8 cycles), including two extra loads which
+ * may cause additional delay in rare cases (load-load replay traps).
*/
.globl csum_ipv6_magic
@@ -55,25 +59,45 @@
csum_ipv6_magic:
.prologue 0
- ldq $0,0($16) # L : Latency: 3
+ ldq_u $0,0($16) # L : Latency: 3
inslh $18,7,$4 # U : 0000000000AABBCC
- ldq $1,8($16) # L : Latency: 3
+ ldq_u $1,8($16) # L : Latency: 3
sll $19,8,$7 # U : U L U L : 0x00000000 00aabb00
+ and $16,7,$6 # E : src misalignment
+ ldq_u $5,15($16) # L : Latency: 3
zapnot $20,15,$20 # U : zero extend incoming csum
- ldq $2,0($17) # L : Latency: 3
- sll $19,24,$19 # U : U L L U : 0x000000aa bb000000
- inswl $18,3,$18 # U : 000000CCDD000000
+ ldq_u $2,0($17) # L : U L U L : Latency: 3
+
+ extql $0,$6,$0 # U :
+ extqh $1,$6,$22 # U :
+ ldq_u $3,8($17) # L : Latency: 3
+ sll $19,24,$19 # U : U U L U : 0x000000aa bb000000
+
+ cmoveq $6,$31,$22 # E : src aligned?
+ ldq_u $23,15($17) # L : Latency: 3
+ or $18,$4,$18 # E : 000000CCDDAABBCC
+ extql $1,$6,$1 # U : U L L U :
- ldq $3,8($17) # L : Latency: 3
- bis $18,$4,$18 # E : 000000CCDDAABBCC
+ or $0,$22,$0 # E : 1st src word complete
+ extqh $5,$6,$5 # U :
addl $19,$7,$19 # E : <sign bits>bbaabb00
- nop # E : U L U L
+ and $17,7,$6 # E : L U L U : dst misalignment
+ inswl $18,3,$18 # U : 000000CCDD000000
+ or $1,$5,$1 # E : 2nd src word complete
+ extql $2,$6,$2 # U :
+ extqh $3,$6,$22 # U : U L U U :
+
+ cmoveq $6,$31,$22 # E : dst aligned?
+ extql $3,$6,$3 # U :
addq $20,$0,$20 # E : begin summing the words
+ extqh $23,$6,$23 # U : L U L U :
+
srl $18,16,$4 # U : 0000000000CCDDAA
+ or $2,$22,$2 # E : 1st dst word complete
zap $19,0x3,$19 # U : <sign bits>bbaa0000
- nop # E : L U U L
+ or $3,$23,$3 # E : U L U L : 2nd dst word complete
cmpult $20,$0,$0 # E :
addq $20,$1,$20 # E :
--- 2.6.22-rc4/arch/alpha/lib/csum_ipv6_magic.S Sun Feb 4 21:44:54 2007
+++ linux/arch/alpha/lib/csum_ipv6_magic.S Sun Jun 17 00:29:28 2007
@@ -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 :
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [patch] alpha: fix alignment problem in csum_ipv6_magic()
2007-06-16 21:20 [patch] alpha: fix alignment problem in csum_ipv6_magic() Ivan Kokshaysky
@ 2007-06-21 23:35 ` Andrew Morton
2007-06-22 11:26 ` Ivan Kokshaysky
0 siblings, 1 reply; 4+ messages in thread
From: Andrew Morton @ 2007-06-21 23:35 UTC (permalink / raw)
To: Ivan Kokshaysky; +Cc: rth, linux-kernel, netdev, Dustin Marquess
> On Sun, 17 Jun 2007 01:20:20 +0400 Ivan Kokshaysky <ink@jurassic.park.msu.ru> wrote:
> 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>
>
> Ivan.
>
> --- 2.6.22-rc4/arch/alpha/lib/ev6-csum_ipv6_magic.S Sun Feb 4 21:44:54 2007
> +++ linux/arch/alpha/lib/ev6-csum_ipv6_magic.S Sun Jun 17 00:41:53 2007
> @@ -46,6 +46,10 @@
> * add the 3 low ushorts together, generating a uint
> * a final add of the 2 lower ushorts
> * truncating the result.
> + *
> + * Misalignment handling added by Ivan Kokshaysky <ink@jurassic.park.msu.ru>
> + * The cost is 16 instructions (~8 cycles), including two extra loads which
> + * may cause additional delay in rare cases (load-load replay traps).
> */
>
> .globl csum_ipv6_magic
> @@ -55,25 +59,45 @@
> csum_ipv6_magic:
> .prologue 0
>
> - ldq $0,0($16) # L : Latency: 3
> + ldq_u $0,0($16) # L : Latency: 3
> inslh $18,7,$4 # U : 0000000000AABBCC
> - ldq $1,8($16) # L : Latency: 3
> + ldq_u $1,8($16) # L : Latency: 3
> sll $19,8,$7 # U : U L U L : 0x00000000 00aabb00
>
> + and $16,7,$6 # E : src misalignment
> + ldq_u $5,15($16) # L : Latency: 3
> zapnot $20,15,$20 # U : zero extend incoming csum
> - ldq $2,0($17) # L : Latency: 3
> - sll $19,24,$19 # U : U L L U : 0x000000aa bb000000
> - inswl $18,3,$18 # U : 000000CCDD000000
> + ldq_u $2,0($17) # L : U L U L : Latency: 3
> +
> + extql $0,$6,$0 # U :
> + extqh $1,$6,$22 # U :
> + ldq_u $3,8($17) # L : Latency: 3
> + sll $19,24,$19 # U : U U L U : 0x000000aa bb000000
> +
> + cmoveq $6,$31,$22 # E : src aligned?
> + ldq_u $23,15($17) # L : Latency: 3
> + or $18,$4,$18 # E : 000000CCDDAABBCC
> + extql $1,$6,$1 # U : U L L U :
>
> - ldq $3,8($17) # L : Latency: 3
> - bis $18,$4,$18 # E : 000000CCDDAABBCC
> + or $0,$22,$0 # E : 1st src word complete
> + extqh $5,$6,$5 # U :
> addl $19,$7,$19 # E : <sign bits>bbaabb00
> - nop # E : U L U L
> + and $17,7,$6 # E : L U L U : dst misalignment
>
> + inswl $18,3,$18 # U : 000000CCDD000000
> + or $1,$5,$1 # E : 2nd src word complete
> + extql $2,$6,$2 # U :
> + extqh $3,$6,$22 # U : U L U U :
> +
> + cmoveq $6,$31,$22 # E : dst aligned?
> + extql $3,$6,$3 # U :
> addq $20,$0,$20 # E : begin summing the words
> + extqh $23,$6,$23 # U : L U L U :
> +
> srl $18,16,$4 # U : 0000000000CCDDAA
> + or $2,$22,$2 # E : 1st dst word complete
> zap $19,0x3,$19 # U : <sign bits>bbaa0000
> - nop # E : L U U L
> + or $3,$23,$3 # E : U L U L : 2nd dst word complete
>
> cmpult $20,$0,$0 # E :
> addq $20,$1,$20 # E :
> --- 2.6.22-rc4/arch/alpha/lib/csum_ipv6_magic.S Sun Feb 4 21:44:54 2007
> +++ linux/arch/alpha/lib/csum_ipv6_magic.S Sun Jun 17 00:29:28 2007
> @@ -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 :
In http://bugzilla.kernel.org/show_bug.cgi?id=8659, Dustin is reporting
that this patch broke tcp-on-ipv6.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [patch] alpha: fix alignment problem in csum_ipv6_magic()
2007-06-21 23:35 ` Andrew Morton
@ 2007-06-22 11:26 ` Ivan Kokshaysky
2007-06-22 16:27 ` Dustin Marquess
0 siblings, 1 reply; 4+ messages in thread
From: Ivan Kokshaysky @ 2007-06-22 11:26 UTC (permalink / raw)
To: Andrew Morton; +Cc: rth, linux-kernel, netdev, Dustin Marquess
On Thu, Jun 21, 2007 at 04:35:01PM -0700, Andrew Morton wrote:
> In http://bugzilla.kernel.org/show_bug.cgi?id=8659, Dustin is reporting
> that this patch broke tcp-on-ipv6.
Oops. Two instructions operating on the 'len' arg ($18) got swapped...
This should fix ev6 version, ev5 one seems to be ok.
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Ivan.
--- 2.6.22-rc4-mm2/arch/alpha/lib/ev6-csum_ipv6_magic.S Fri Jun 22 15:02:23 2007
+++ linux/arch/alpha/lib/ev6-csum_ipv6_magic.S Fri Jun 22 15:05:38 2007
@@ -76,18 +76,18 @@ csum_ipv6_magic:
cmoveq $6,$31,$22 # E : src aligned?
ldq_u $23,15($17) # L : Latency: 3
- or $18,$4,$18 # E : 000000CCDDAABBCC
- extql $1,$6,$1 # U : U L L U :
+ inswl $18,3,$18 # U : 000000CCDD000000
+ addl $19,$7,$19 # E : U L U L : <sign bits>bbaabb00
or $0,$22,$0 # E : 1st src word complete
- extqh $5,$6,$5 # U :
- addl $19,$7,$19 # E : <sign bits>bbaabb00
- and $17,7,$6 # E : L U L U : dst misalignment
+ extql $1,$6,$1 # U :
+ or $18,$4,$18 # E : 000000CCDDAABBCC
+ extqh $5,$6,$5 # U : L U L U
- inswl $18,3,$18 # U : 000000CCDD000000
- or $1,$5,$1 # E : 2nd src word complete
+ and $17,7,$6 # E : dst misalignment
extql $2,$6,$2 # U :
- extqh $3,$6,$22 # U : U L U U :
+ or $1,$5,$1 # E : 2nd src word complete
+ extqh $3,$6,$22 # U : L U L U :
cmoveq $6,$31,$22 # E : dst aligned?
extql $3,$6,$3 # U :
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [patch] alpha: fix alignment problem in csum_ipv6_magic()
2007-06-22 11:26 ` Ivan Kokshaysky
@ 2007-06-22 16:27 ` Dustin Marquess
0 siblings, 0 replies; 4+ messages in thread
From: Dustin Marquess @ 2007-06-22 16:27 UTC (permalink / raw)
To: Ivan Kokshaysky; +Cc: Andrew Morton, rth, linux-kernel, netdev
Ivan Kokshaysky wrote:
> On Thu, Jun 21, 2007 at 04:35:01PM -0700, Andrew Morton wrote:
>> In http://bugzilla.kernel.org/show_bug.cgi?id=8659, Dustin is reporting
>> that this patch broke tcp-on-ipv6.
>
> Oops. Two instructions operating on the 'len' arg ($18) got swapped...
> This should fix ev6 version, ev5 one seems to be ok.
>
> Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
>
> Ivan.
>
> --- 2.6.22-rc4-mm2/arch/alpha/lib/ev6-csum_ipv6_magic.S Fri Jun 22 15:02:23 2007
> +++ linux/arch/alpha/lib/ev6-csum_ipv6_magic.S Fri Jun 22 15:05:38 2007
> @@ -76,18 +76,18 @@ csum_ipv6_magic:
>
> cmoveq $6,$31,$22 # E : src aligned?
> ldq_u $23,15($17) # L : Latency: 3
> - or $18,$4,$18 # E : 000000CCDDAABBCC
> - extql $1,$6,$1 # U : U L L U :
> + inswl $18,3,$18 # U : 000000CCDD000000
> + addl $19,$7,$19 # E : U L U L : <sign bits>bbaabb00
>
> or $0,$22,$0 # E : 1st src word complete
> - extqh $5,$6,$5 # U :
> - addl $19,$7,$19 # E : <sign bits>bbaabb00
> - and $17,7,$6 # E : L U L U : dst misalignment
> + extql $1,$6,$1 # U :
> + or $18,$4,$18 # E : 000000CCDDAABBCC
> + extqh $5,$6,$5 # U : L U L U
>
> - inswl $18,3,$18 # U : 000000CCDD000000
> - or $1,$5,$1 # E : 2nd src word complete
> + and $17,7,$6 # E : dst misalignment
> extql $2,$6,$2 # U :
> - extqh $3,$6,$22 # U : U L U U :
> + or $1,$5,$1 # E : 2nd src word complete
> + extqh $3,$6,$22 # U : L U L U :
>
> cmoveq $6,$31,$22 # E : dst aligned?
> extql $3,$6,$3 # U :
>
Awesome! Works like a champ! Thank you guys so very much! You rock!
-Dustin
^ permalink raw reply [flat|nested] 4+ messages in thread
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2007-06-16 21:20 [patch] alpha: fix alignment problem in csum_ipv6_magic() Ivan Kokshaysky
2007-06-21 23:35 ` Andrew Morton
2007-06-22 11:26 ` Ivan Kokshaysky
2007-06-22 16:27 ` Dustin Marquess
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