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Revision f32ab7547161b9fa7ebfbc4f18ea1eb3fd49fe25 authored by =?UTF-8?q?Christian=20K=C3=B6nig?= on 11 January 2018, 13:23:29 UTC, committed by Bjorn Helgaas on 11 January 2018, 17:22:39 UTC 
x86/PCI: Add "pci=big_root_window" option for AMD 64-bit windows
 
Only try to enable a 64-bit window on AMD CPUs when "pci=big_root_window"
is specified.

This taints the kernel because the new 64-bit window uses address space we
don't know anything about, and it may contain unreported devices or memory
that would conflict with the window.

The pci_amd_enable_64bit_bar() quirk that enables the window is specific to
AMD CPUs.  The generic solution would be to have the firmware enable the
window and describe it in the host bridge's _CRS method, or at least
describe it in the _PRS method so the OS would have the option of enabling
it.

Signed-off-by: Christian König <christian.koenig@amd.com>
[bhelgaas: changelog, extend doc, mention taint in dmesg]
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
1 parent 1291a0d
Raw File
extract-ikconfig 
#!/bin/sh
# ----------------------------------------------------------------------
# extract-ikconfig - Extract the .config file from a kernel image
#
# This will only work when the kernel was compiled with CONFIG_IKCONFIG.
#
# The obscure use of the "tr" filter is to work around older versions of
# "grep" that report the byte offset of the line instead of the pattern.
#
# (c) 2009,2010 Dick Streefland <dick@streefland.net>
# Licensed under the terms of the GNU General Public License.
# ----------------------------------------------------------------------

cf1='IKCFG_ST\037\213\010'
cf2='0123456789'

dump_config()
{
	if	pos=`tr "$cf1\n$cf2" "\n$cf2=" < "$1" | grep -abo "^$cf2"`
	then
		pos=${pos%%:*}
		tail -c+$(($pos+8)) "$1" | zcat > $tmp1 2> /dev/null
		if	[ $? != 1 ]
		then	# exit status must be 0 or 2 (trailing garbage warning)
			cat $tmp1
			exit 0
		fi
	fi
}

try_decompress()
{
	for	pos in `tr "$1\n$2" "\n$2=" < "$img" | grep -abo "^$2"`
	do
		pos=${pos%%:*}
		tail -c+$pos "$img" | $3 > $tmp2 2> /dev/null
		dump_config $tmp2
	done
}

# Check invocation:
me=${0##*/}
img=$1
if	[ $# -ne 1 -o ! -s "$img" ]
then
	echo "Usage: $me <kernel-image>" >&2
	exit 2
fi

# Prepare temp files:
tmp1=/tmp/ikconfig$$.1
tmp2=/tmp/ikconfig$$.2
trap "rm -f $tmp1 $tmp2" 0

# Initial attempt for uncompressed images or objects:
dump_config "$img"

# That didn't work, so retry after decompression.
try_decompress '\037\213\010' xy    gunzip
try_decompress '\3757zXZ\000' abcde unxz
try_decompress 'BZh'          xy    bunzip2
try_decompress '\135\0\0\0'   xxx   unlzma
try_decompress '\211\114\132' xy    'lzop -d'
try_decompress '\002\041\114\030' xyy 'lz4 -d -l'

# Bail out:
echo "$me: Cannot find kernel config." >&2
exit 1
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