sh4 pmap bug? (Re: port-dreamcast/34243)

"Valeriy E. Ushakov" <[email protected]> Wed, 23 Aug 2006 16:26:46 +0400
Newsgroups gmane.os.netbsd.ports.sh3
Message-ID <[email protected]> 
Can someone who is more familiar with sh4 pmap take a look at this PR?

On Wed, Aug 23, 2006 at 06:02:04 +0400, Valeriy E. Ushakov wrote:

> I've traced it a bit further.  What happens is that we see an infinite
> recurring tlb miss for the instruction we are stuck at:
> 
>   0x20690a9c:     mov.l   @r4, r1         ! where r4 == 0x206a0fcc
> 
> Some debugging printfs show that the following sequence of calls is
> repeated over and over:
> 
>   tlbinv: va=20690000 (from pmap_remove)
> 
>   _pteld: va=20690a9c flags=1 -> entry == 0
> 
>   tlbupd: va=20690000 pte=0c6f1158 (from pmap_enter)
>   tlbinv: va=20690000 (from sh4_tlb_update)
> 
>   _pteld: va=20690a9c flags=1 -> entry=0c6f1158 =V
>   tlbupd: va=20690a9c pte=0c6f1158 (from __pmap_pte_load)
>   tlbinv: va=20690a9c (from sh4_tlb_update)
> 
> 
> And DDB shows that TLB looks very strage.  Note lots of invalid
> entries for the page in question:
> 
> db> mach tlb
> multiple virtual storage mode, SQ access: (kernel)
> random counter limit=61
> ASID=3 (passwd)---ITLB DUMP ---
>    VPN      ASID    PFN  AREA VDCGWtPR  SZ TC SA
>           U/K                       U/K
> 0x20690800     3 0x0c6f1000 3 ._|._ rr  4K
> 0x20690800     3 0x0c6f1000 3 |_|._ rr  4K
> 0x20690800     3 0x0c6f1000 3 ._|._ rr  4K
> 0x20690800     3 0x0c6f1000 3 ._|._ rr  4K
> ---UTLB DUMP---
>    VPN      ASID    PFN  AREA VDCGWtPR  SZ TC SA
>           U/K                       U/K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0xc0024000     0 0x0ff68000 3 ||||. _w  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0xc0046000     0 0x0ff43000 3 ||||. _w  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0xc1648000     0 0x0ffe1000 3 ||||. _w  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0xc006e000     0 0x0d440000 3 ||||. _w  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 |.|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0xc0063000     0 0x0ff17000 3 ||||. _w  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0xc1adf000     0 0x0d429000 3 ||||. _w  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0xc0060000     0 0x0ff1a000 3 ||||. _w  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0xc006d000     0 0x0d445000 3 ||||. _w  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0xc0064000     0 0x0ff16000 3 ||||. _w  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0xc005f000     0 0x0ff1b000 3 ||||. _w  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0xc004d000     0 0x0ff3c000 3 ||||. _w  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0xc001d000     0 0x0ff70000 3 ||||. _w  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x206a0000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0x20690000     3 0x0c6f1000 3 ..|.. rr  4K
> 0xc000a000     0 0x0ffcd000 3 ||||. _w  4K
> 0xc004e000     0 0x0ff3a000 3 ||||. _w  4K
> 0xc0023000     0 0x0ff6a000 3 ||||. _w  4K
> 0xc2344000     0 0x0c676000 3 ||||. _w  4K
> 0xc2345000     0 0x0c677000 3 ||||. _w  4K
> 0xc2346000     0 0x0c678000 3 ||||. _w  4K

SY, Uwe
-- 
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