From: Greg Kroah-Hartman <gregkh@suse.de>
Subject: Linux 2.6.27.6

Upstream 2.6.27.6 release from kernel.org

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Automatically created from "patches.kernel.org/patch-2.6.27.5-6" by xen-port-patches.py

Index: head-2008-11-17/arch/x86/Kconfig
===================================================================
--- head-2008-11-17.orig/arch/x86/Kconfig	2008-11-18 16:18:56.000000000 +0100
+++ head-2008-11-17/arch/x86/Kconfig	2008-11-18 16:19:14.000000000 +0100
@@ -1143,6 +1143,7 @@ config HIGHPTE
 config X86_RESERVE_LOW_64K
         bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
 	default y
+	depends on !XEN
 	help
 	 Reserve the first 64K of physical RAM on BIOSes that are known
 	 to potentially corrupt that memory range. A numbers of BIOSes are
Index: head-2008-11-17/arch/x86/kernel/setup-xen.c
===================================================================
--- head-2008-11-17.orig/arch/x86/kernel/setup-xen.c	2008-11-17 13:42:08.000000000 +0100
+++ head-2008-11-17/arch/x86/kernel/setup-xen.c	2008-11-17 13:55:53.000000000 +0100
@@ -645,6 +645,41 @@ static struct x86_quirks default_x86_qui
 
 struct x86_quirks *x86_quirks __initdata = &default_x86_quirks;
 
+#ifdef CONFIG_X86_RESERVE_LOW_64K
+static int __init dmi_low_memory_corruption(const struct dmi_system_id *d)
+{
+	printk(KERN_NOTICE
+		"%s detected: BIOS may corrupt low RAM, working it around.\n",
+		d->ident);
+
+	e820_update_range(0, 0x10000, E820_RAM, E820_RESERVED);
+	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+
+	return 0;
+}
+#endif
+
+/* List of systems that have known low memory corruption BIOS problems */
+static struct dmi_system_id __initdata bad_bios_dmi_table[] = {
+#ifdef CONFIG_X86_RESERVE_LOW_64K
+	{
+		.callback = dmi_low_memory_corruption,
+		.ident = "AMI BIOS",
+		.matches = {
+			DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
+		},
+	},
+	{
+		.callback = dmi_low_memory_corruption,
+		.ident = "Phoenix BIOS",
+		.matches = {
+			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies, LTD"),
+		},
+	},
+#endif
+	{}
+};
+
 /*
  * Determine if we were loaded by an EFI loader.  If so, then we have also been
  * passed the efi memmap, systab, etc., so we should use these data structures
@@ -819,6 +854,11 @@ void __init setup_arch(char **cmdline_p)
 
 	finish_e820_parsing();
 
+	if (is_initial_xendomain()) {
+		dmi_scan_machine();
+		dmi_check_system(bad_bios_dmi_table);
+	}
+
 #ifdef CONFIG_X86_32
 	probe_roms();
 #endif
@@ -922,9 +962,6 @@ void __init setup_arch(char **cmdline_p)
 	vsmp_init();
 #endif
 
-	if (is_initial_xendomain())
-		dmi_scan_machine();
-
 	io_delay_init();
 
 #ifdef CONFIG_ACPI