From: Yinghai Lu <yinghai@kernel.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
Suresh Siddha <suresh.b.siddha@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Ralf Jung <ralfjung-e@gmx.de>,
Cyrill Gorcunov <gorcunov@openvz.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] x86, ioapic: Reserve only 128 bytes for IOAPICs
Date: Thu, 25 Aug 2011 23:18:42 -0700 [thread overview]
Message-ID: <4E573AC2.2070908@kernel.org> (raw)
In-Reply-To: <4E56F9E5.4000005@zytor.com>
On 08/25/2011 06:41 PM, H. Peter Anvin wrote:
> On 08/25/2011 05:17 PM, Bjorn Helgaas wrote:
>>
>> If the OS allocated the next 128 bytes to another device, it sounds
>> like it would cause a conflict on Intel boxes. This must be an area
>> that differs between vendors. I haven't seen a spec that mentions 256
>> bytes as the required minimum MMIO size for IOAPICs, and apparently
>> the AMD IOAPIC decodes 240 bytes or fewer.
>>
>
> For what it's worth, it's probably a bad idea on x86 for the OS to
> allocate addresses in the 0xFExxxxxx range...
>
for system with more than one ioapic controllers, could have ioapic address rather low.
and those address are allocated to some pci devices BAR by BIOS.
Yinghai
next prev parent reply other threads:[~2011-08-26 6:19 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-25 23:05 [PATCH 1/2] x86, ioapic: Reserve only 128 bytes for IOAPICs Bjorn Helgaas
2011-08-25 23:05 ` [PATCH 2/2] x86, ioapic: Announce resources reserved " Bjorn Helgaas
2011-08-25 23:33 ` [PATCH 1/2] x86, ioapic: Reserve only 128 bytes " Suresh Siddha
2011-08-26 0:17 ` Bjorn Helgaas
2011-08-26 1:41 ` H. Peter Anvin
2011-08-26 6:18 ` Yinghai Lu [this message]
2011-08-26 6:48 ` Cyrill Gorcunov
2011-08-26 9:22 ` Ralf Jung
2011-08-26 9:39 ` Cyrill Gorcunov
2011-08-26 9:53 ` Ralf Jung
2011-08-26 9:56 ` Cyrill Gorcunov
2011-08-26 6:22 ` Cyrill Gorcunov
2011-08-26 16:21 ` Bjorn Helgaas
2011-08-26 16:24 ` H. Peter Anvin
2011-08-26 18:09 ` Cyrill Gorcunov
2011-08-26 18:21 ` H. Peter Anvin
2011-08-26 19:15 ` Cyrill Gorcunov
[not found] ` <CAErSpo5kEw=VTVv-=_D3hQg5oRNL9yEyJUnpP0biH=t3WRXMZw@mail.gmail.com>
2011-08-26 21:09 ` Fwd: " Ralf Jung
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