Re: Issue booting v2.6.39 .. v3.4-rc6 on hp712/100

[John David Anglin <dave.anglin@bell.net>]

On 5/15/2012 5:13 AM, James Bottomley wrote:
> On Tue, 2012-05-15 at 09:09 +0100, James Bottomley wrote:
>> On Mon, 2012-05-14 at 18:38 -0400, John David Anglin wrote:
>>> On 14-May-12, at 6:11 PM, Helge Deller wrote:
>>>
>>>> The B160L and the 715/64 (both 32bit-only PA1.X machines) crashed
>>>> with the following trace.
>>>> All logs attached.
>>>>
>>>> Any ideas?
>>> This is exactly the same failure as reported by Vincent.
>>>
>>> The most likely problem is the PA 1.1 tmpalias support in entry.S is
>>> broken.  For example,
>>> the cache stride that is loaded in flush_dcache_page_asm to register
>>> r1 is wrong.  Probably,
>>> the do_alias macro is wrong for PA 1.1.  This is hunk of code that
>>> should be executed
>>> when a fdc non access fault occurs.
>>>
>>> nadtlb_check_alias_11:
>>>           do_alias        spc,t0,t1,va,pte,prot,nadtlb_emulate
>>>
>>>           idtlba          pte,(va)
>>>           idtlbp          prot,(va)
>>>
>>>           rfir
>>>           nop
>>>
>>> The TLB insert instructions on PA 1.1 have a different format than on
>>> PA 2.0.  I'm not sure
>>> how this would corrupt r1.
>>>
>>> On the other hand, I had asked Vincent to put a "b,n ." instruction
>>> just before the fdc loop,
>>> boot, hit the TOC button, and capture the setup registers for the
>>> flush operation.  It's possible
>>> the stride variable has been clobbered.
>> Actually, I don't think it's that.  I built a PA 1.1 only kernel and
>> booted it successfully on the C360.  That exercises all the _11 paths,
>> so I don't think there's a code fault.  I do think there's a non PA1.1
>> instruction in there somewhere that the C360 wouldn't notice.
> OK, I think this is the problem.  We have a depd instruction in do_alias
> which is now in the _11 fault paths.
>
> This should be the fix, if someone wants to test it before I can get
> around to building it.
>
> James
>
> ---
>
> diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
> index 6f05944..5350342 100644
> --- a/arch/parisc/kernel/entry.S
> +++ b/arch/parisc/kernel/entry.S
> @@ -581,7 +581,11 @@
>   	 */
>   	cmpiclr,=	0x01,\tmp,%r0
>   	ldi		(_PAGE_DIRTY|_PAGE_READ|_PAGE_WRITE),\prot
> +#ifdef CONFIG_64BIT
>   	depd,z		\prot,8,7,\prot
> +#else
> +	depw,z		\prot,8,7,\prot
> +#endif
>   	/*
>   	 * OK, it is in the temp alias region, check whether "from" or "to".
>   	 * Check "subtle" note in pacache.S re: r23/r26.
Better check that this fix doesn't break 32-bit PA 2.0 as the seven bit 
are now being deposited
in a different place.

Dave

-- 
John David Anglin    dave.anglin@bell.net