From: Geoff Levand <geoffrey.levand@am•sony.com>
To: benh@kernel•crashing.org
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom•com>,
Linux/PPC Development <linuxppc-dev@ozlabs•org>
Subject: Re: PS3 early lock-up
Date: Mon, 4 Aug 2008 17:31:43 -0700 [thread overview]
Message-ID: <48979F6F.1050507@am.sony.com> (raw)
In-Reply-To: <1217886777.24157.91.camel@pasglop>
Hi,
Benjamin Herrenschmidt wrote:
>> > ps3_hpte_insert() seems to be called during system initialization with the
>> > following values of rflags:
>> > - first call: 0x190
>> > - initial memory: 0x194 (455 times)
>> > - hotplug memory:
>> > o crash: 0x115
>> > o OK: 0x117
>> >
>> > Do you have an idea of what's really going on?
>>
>> Weird... Both look incorrect. In fact, it's a bit scary...
>>
>> The one with the 7 at the end means that user space as RO access to
>> the segment (oops !) and supervisor too. The one with the 5 means
>> RO for user and RW for supervisor.
>>
>> That is unless your HV is munging them in strange ways... I don't
>> know why LV1 is refusing a combination though.
>>
>> As for the flags, it depends what htab_bolt_mapping() is called
>> with.
>>
>> Do you have a backtrace ? I'm a bit lots in the mem hotswap code
>> trying to figure out where the mapping comes from..
>
> Ah, found it... It should be ok... both the mapping of the RAM itself
> and vmemmap_populate() should be passing
>
> _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX;
>
> Which should be 0x194.
That is 0x190.
0x194 = _PAGE_EXEC | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX
>
> Can you find out where that stupid value comes from ?
I didn't have time to look at in detail, but it fails from the
ioremap call in ps3_map_htab (arch/powerpc/platfroms/ps3/htab.c):
htab = (__force struct hash_pte *)ioremap_flags(htab_addr, htab_size,
pgprot_val(PAGE_READONLY_X));
IIRC, lv1 doesn't allow a read/write mapping of the htab, and that is
why I used pgprot_val(PAGE_READONLY_X) here.
I guess the value returned from pgprot_val(PAGE_READONLY_X)
changed in recent kernels, and that is what is causing the failure.
Just FYI, I put these in:
printk("%s:%d: flags = %x\n", __func__, __LINE__, (_PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX));
printk("%s:%d: flags = %x\n", __func__, __LINE__, pgprot_val(PAGE_READONLY_X));
and got this (and lv1_write_htab_entry failed):
ps3_map_htab:288: flags = 190
ps3_map_htab:289: flags = 117
-Geoff
next prev parent reply other threads:[~2008-08-05 0:32 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-04 15:48 PS3 early lock-up Geert Uytterhoeven
2008-08-04 21:44 ` Benjamin Herrenschmidt
2008-08-04 21:52 ` Benjamin Herrenschmidt
2008-08-05 0:31 ` Geoff Levand [this message]
2008-08-05 1:40 ` Benjamin Herrenschmidt
2008-08-05 9:43 ` Geert Uytterhoeven
2008-08-05 10:28 ` Benjamin Herrenschmidt
2008-08-05 11:31 ` Benjamin Herrenschmidt
2008-08-05 23:24 ` Geoff Levand
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