From: Nikunj A Dadhania <nikunj@linux•vnet.ibm.com>
To: Thomas Huth <thuth@redhat•com>
Cc: aik@ozlabs•ru, linuxppc-dev@ozlabs•org, david@gibson•dropbear.id.au
Subject: Re: [PATCH 1/2] pci-phb: check for the 32-bit overflow
Date: Fri, 24 Apr 2015 09:22:33 +0530 [thread overview]
Message-ID: <871tjaxjwe.fsf@abhimanyu.in.ibm.com> (raw)
In-Reply-To: <20150423154314.595b8439@thh440s>
Hi Thomas,
Thomas Huth <thuth@redhat•com> writes:
> Am Wed, 22 Apr 2015 16:27:19 +0530
> schrieb Nikunj A Dadhania <nikunj@linux•vnet.ibm.com>:
>
>> With the addition of 64-bit BARS and increase in the mmio address
>> space, the code was hitting this limit. The memory of pci devices
>> across the bridges were not accessible due to which the drivers
>> failed.
>>
>> Signed-off-by: Nikunj A Dadhania <nikunj@linux•vnet.ibm.com>
>> ---
>> board-qemu/slof/pci-phb.fs | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/board-qemu/slof/pci-phb.fs b/board-qemu/slof/pci-phb.fs
>> index 529772f..e307d95 100644
>> --- a/board-qemu/slof/pci-phb.fs
>> +++ b/board-qemu/slof/pci-phb.fs
>> @@ -258,7 +258,8 @@ setup-puid
>> decode-64 2 / dup >r \ Decode and calc size/2
>> pci-next-mem @ + dup pci-max-mem ! \ and calc max mem address
>
> Could pci-max-mem overflow, too?
Should not, its only the boundary that was an issue.
Qemu sends base and size, base + size can be till uint32 max. So for
example base was 0xC000.0000 and size was 0x4000.0000, we add up base +
size and put pci-max-mmio as 0x1.0000.0000, which would get programmend
in the bridge bars: lower limit as 0xC000 and 0x0000 as upper
limit. And no mmio access were going across the bridge.
In my testing, I have found one more issue with translate-my-address,
it does not take care of 64-bit addresses. I have a patch working for
SLOF, but its breaking the guest kernel booting.
>
>> dup pci-next-mmio ! \ which is the same as MMIO base
>> - r> + pci-max-mmio ! \ calc max MMIO address
>> + r> + FFFFFFFF min pci-max-mmio ! \ calc max MMIO address and
>> + \ check the 32-bit boundary
>
> Thomas
Regards,
Nikunj
next prev parent reply other threads:[~2015-04-24 3:52 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-22 10:57 [PATCH 1/2] pci-phb: check for the 32-bit overflow Nikunj A Dadhania
2015-04-23 13:43 ` Thomas Huth
2015-04-24 3:52 ` Nikunj A Dadhania [this message]
2015-04-24 10:56 ` Thomas Huth
2015-04-24 11:06 ` Thomas Huth
2015-04-27 5:00 ` Nikunj A Dadhania
2015-04-27 5:41 ` Nikunj A Dadhania
2015-04-27 4:58 ` Nikunj A Dadhania
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