From: "H. Peter Anvin" <hpa@zytor.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: guenter.roeck@ericsson.com, linux-kernel@vger.kernel.org,
Yinghai <yinghai.lu@oracle.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Bjorn Helgaas <bjorn.helgaas@hp.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"x86@kernel.org" <x86@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 15:42:17 -0700 [thread overview]
Message-ID: <4BBFAD49.3000208@zytor.com> (raw)
In-Reply-To: <20100409234245.4081994a@lxorguk.ukuu.org.uk>
On 04/09/2010 03:42 PM, Alan Cox wrote:
>> "Don't use legacy fixed-function addresses for nonstandard purposes."
>>
>> There, there is your documentation.
>
> It's probably a good idea to only reserve it if the space is actually
> being used. There are a variety of legitimate reasons to use that space
> for other things on embedded x86 boards.
>
> They are only "legacy fixed function" if you have a PCI bus...
No they're not. The 0xa0000...0xbffff range has been a legacy video
area since the very first PC (although the first PC only used
0xb0000..0xbffff, 0xa0000..0xbffff was declared reserved at that time.)
I'm wondering what those legitimate reasons are. This is particularly
so since it affects our ability to deal with very early errors, long
before we have enumerated anything. At this point we can at least lay
down bytes in the video area and hope the user can see them.
-hpa
next prev parent reply other threads:[~2010-04-09 22:43 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 [this message]
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
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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