From: "H. Peter Anvin" <hpa@zytor.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>,
Yinghai <yinghai.lu@oracle.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
linux-pci@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org, Andy Isaacson <adi@hexapodia.org>,
Thomas Renninger <trenn@suse.de>
Subject: Re: [PATCH] x86: Reserve legacy VGA MMIO area for x86_64 as well as x86_32
Date: Fri, 09 Apr 2010 15:55:58 -0700 [thread overview]
Message-ID: <4BBFB07E.9020108@zytor.com> (raw)
In-Reply-To: <20100409235148.793e4200@lxorguk.ukuu.org.uk>
On 04/09/2010 03:51 PM, Alan Cox wrote:
>> Why is this different for 64-bit vs 32-bit? Can you point me to any
>> references where I can learn about this?
>
> IMHO its wrong for both
>
> You can only reserve the region in question if you actually have a VGA
> device and mappings present.
>
> It's wrong for non PCI systems
> It's wrong for legacy ISA systems with monochrome video/no video
> It's wrong for several embedded platforms.
> It's wrong if PCI isn't your root bridge
>
> Basically the reservation is the wrong way to fix it. A much saner way to
> fix it would be to simply keep a list of address ranges not to use for
> PCI device relocation. For I/O ports of course we just fix up the PCI
> resources of the device to list them as we discover it (IDE legacy).
>
> You don't want to put anything at the VGA address that needs assigning an
> address. That is *totally* different to the question of whether you want
> to believe the space is 'reserved'. If something is at that address then
> presumably the firmware knows what it is doing. If a device driver wishes
> to reserve that address it's doing so with more information, later in
> boot so should be allowed to.
That's what I mean with reserved, I'm using the term in the
E820_RESERVED sense. As in "don't put anything there without it being
an explicit assignment".
-hpa
next prev parent reply other threads:[~2010-04-09 22:56 UTC|newest]
Thread overview: 110+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-07 21:06 [PATCH] x86: Reserve legacy VGA MMIO area for x86_64 as well as x86_32 Bjorn Helgaas
2010-04-07 22:45 ` Yinghai
2010-04-07 23:05 ` Bjorn Helgaas
2010-04-07 23:22 ` Yinghai
2010-04-08 3:24 ` Bjorn Helgaas
2010-04-08 4:42 ` H. Peter Anvin
2010-04-08 13:04 ` Bjorn Helgaas
2010-04-09 16:04 ` Bjorn Helgaas
2010-04-09 16:44 ` H. Peter Anvin
2010-04-09 17:22 ` Yinghai
2010-04-09 18:23 ` H. Peter Anvin
2010-04-09 18:55 ` Guenter Roeck
2010-04-09 19:55 ` Yinghai
2010-04-09 22:21 ` Andy Isaacson
2010-04-09 22:27 ` Yinghai Lu
2010-04-09 22:35 ` Andy Isaacson
2010-04-09 22:44 ` H. Peter Anvin
2010-04-09 22:54 ` Yinghai
2010-04-09 23:01 ` Yinghai
2010-04-10 0:00 ` Andy Isaacson
2010-04-10 1:10 ` Yinghai
2010-04-10 1:43 ` Andy Isaacson
2010-04-10 1:48 ` Yinghai
2010-04-10 1:57 ` Andy Isaacson
2010-04-10 2:46 ` Yinghai
2010-04-12 18:54 ` Andy Isaacson
2010-04-12 19:34 ` Yinghai
2010-04-12 19:48 ` Andy Isaacson
2010-04-12 19:55 ` yinghai.lu
2010-04-12 20:02 ` Andy Isaacson
2010-04-12 22:32 ` [PATCH -v2 1/2] x86: Reserve [0xa0000, 0x100000] in e820 map Yinghai
2010-04-13 21:02 ` Bjorn Helgaas
2010-04-13 21:08 ` Yinghai
2010-04-13 21:09 ` H. Peter Anvin
2010-04-13 21:11 ` Yinghai
2010-04-13 21:18 ` H. Peter Anvin
2010-04-13 21:22 ` [PATCH -v3 1/3] " Yinghai
2010-04-23 23:30 ` H. Peter Anvin
2010-04-26 15:35 ` Jesse Barnes
2010-04-13 21:23 ` [PATCH -v3 2/3] x86,pci, acpi: host bridge windows inherit BUSY flag from parent Yinghai
2010-04-13 21:24 ` [PATCH -v3 3/3] pci: don't allocate from a BUSY bus resource Yinghai
2010-04-13 21:42 ` [PATCH -v2 1/2] x86: Reserve [0xa0000, 0x100000] in e820 map Yinghai
2010-04-13 21:58 ` H. Peter Anvin
2010-04-13 22:29 ` Yinghai
2010-04-13 22:39 ` Yinghai
2010-04-13 22:41 ` H. Peter Anvin
2010-04-13 22:58 ` Yinghai
2010-04-13 23:02 ` H. Peter Anvin
2010-04-13 23:03 ` Yinghai
2010-04-13 23:07 ` H. Peter Anvin
2010-04-13 23:09 ` Yinghai
2010-04-21 5:33 ` [PATCH -v4 1/3] " Yinghai
2010-04-21 5:34 ` [PATCH 2/3] x86, resource: Add reserve_region_with_split_check_child() Yinghai
2010-04-21 5:35 ` [PATCH 3/3] x86,pci,acpi: Handle invalid _CRS Yinghai
2010-04-21 15:21 ` Bjorn Helgaas
2010-04-21 16:45 ` Yinghai Lu
2010-04-21 16:59 ` Bjorn Helgaas
2010-04-21 22:33 ` H. Peter Anvin
2010-04-21 23:04 ` Bjorn Helgaas
2010-04-21 23:10 ` H. Peter Anvin
2010-04-21 23:43 ` Yinghai
2010-04-22 0:02 ` H. Peter Anvin
2010-04-22 0:06 ` Yinghai
2010-04-21 19:31 ` [PATCH -v4 1/3] x86: Reserve [0xa0000, 0x100000] in e820 map Andy Isaacson
2010-04-23 23:05 ` [PATCH] x86/PCI: never allocate PCI MMIO resources below BIOS_END Bjorn Helgaas
2010-04-23 23:44 ` H. Peter Anvin
2010-04-24 0:36 ` Yinghai Lu
2010-04-26 12:50 ` R. Andrew Bailey
2010-04-26 15:40 ` Bjorn Helgaas
2010-04-26 18:34 ` Andy Isaacson
2010-04-26 19:31 ` Jesse Barnes
2010-04-26 20:27 ` Bjorn Helgaas
2010-04-26 20:37 ` Jesse Barnes
2010-04-26 21:07 ` Yinghai
2010-04-26 21:19 ` H. Peter Anvin
2010-04-26 21:12 ` H. Peter Anvin
2010-04-26 21:25 ` Jesse Barnes
2010-04-26 21:44 ` H. Peter Anvin
2010-04-26 21:53 ` Jesse Barnes
2010-04-26 21:59 ` Yinghai Lu
2010-04-26 22:04 ` [PATCH -v5] reserve a0000 - 0x10000 Yinghai
[not found] ` <4BD60CD4.9020708@oracle.com>
2010-04-26 22:04 ` [PATCH -v5 1/3] x86: Reserve [0xa0000, 0x100000] in e820 map Yinghai
2010-04-26 22:04 ` [PATCH -v5 2/3] x86: Remove probe_roms for 32bit Yinghai
2010-04-26 22:04 ` [PATCH -v5 3/3] x86, resource: Add reserve_region_with_split_check_child() Yinghai
2010-04-26 21:44 ` [PATCH] x86/PCI: never allocate PCI MMIO resources below BIOS_END jacob pan
2010-04-13 23:03 ` [PATCH -v2 1/2] x86: Reserve [0xa0000, 0x100000] in e820 map H. Peter Anvin
2010-04-14 0:57 ` Yinghai
2010-04-14 16:55 ` Bjorn Helgaas
2010-04-14 17:21 ` Yinghai Lu
2010-04-14 19:25 ` Andy Isaacson
2010-04-14 19:27 ` Yinghai
2010-04-14 19:43 ` Andy Isaacson
2010-04-14 19:49 ` Yinghai
2010-04-12 22:33 ` [PATCH -v2 2/2] x86,pci, acpi: Inherent BUSY flag when setup_resource for root bus Yinghai
2010-04-12 22:44 ` Jesse Barnes
2010-04-13 21:02 ` Bjorn Helgaas
2010-04-09 20:11 ` [PATCH] x86: Reserve legacy VGA MMIO area for x86_64 as well as x86_32 H. Peter Anvin
2010-04-09 20:31 ` Guenter Roeck
2010-04-09 20:44 ` H. Peter Anvin
2010-04-09 21:01 ` Guenter Roeck
2010-04-09 22:42 ` Alan Cox
2010-04-09 22:42 ` H. Peter Anvin
2010-04-09 22:54 ` Alan Cox
2010-04-09 22:55 ` H. Peter Anvin
2010-04-09 22:51 ` Alan Cox
2010-04-09 22:55 ` H. Peter Anvin [this message]
2010-04-07 23:43 ` H. Peter Anvin
2010-04-08 0:19 ` Andy Isaacson
2010-04-08 5:00 ` H. Peter Anvin
2010-04-08 21:40 ` Andy Isaacson
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