From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Yinghai <yinghai.lu@oracle.com>, "H. Peter Anvin" <hpa@zytor.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, 9 Apr 2010 23:51:48 +0100 [thread overview]
Message-ID: <20100409235148.793e4200@lxorguk.ukuu.org.uk> (raw)
In-Reply-To: <201004091004.39857.bjorn.helgaas@hp.com>
> 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.
Alan
next prev parent reply other threads:[~2010-04-09 22:48 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 [this message]
2010-04-09 22:55 ` H. Peter Anvin
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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