[PATCH] x86: Disable MMCONFIG on Intel SDV using DMI blacklist

As a replacement for the earlier removal of the e820 MCFG check
we blacklist the Intel SDV with the original BIOS bug that
motivated that check. On those machines don't use MMCONFIG.

This also adds a new pci=mmconf parameter to override the blacklist.

Cc: Greg KH <gregkh@suse.de>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 24 insertions, 1 deletions

diff --git a/arch/x86_64/pci/mmconfig.c b/arch/x86_64/pci/mmconfig.c
index 8a4a0f9..2d48a79 100644
--- a/arch/x86_64/pci/mmconfig.c
+++ b/arch/x86_64/pci/mmconfig.c
@@ -9,6 +9,7 @@
 #include <linux/init.h>
 #include <linux/acpi.h>
 #include <linux/bitmap.h>
+#include <linux/dmi.h>
 #include <asm/e820.h>
 
 #include "pci.h"
@@ -164,11 +165,33 @@ static __init void unreachable_devices(void)
 	}
 }
 
+static int disable_mcfg(struct dmi_system_id *d)
+{
+	printk("PCI: %s detected. Disabling MCFG.\n", d->ident);
+	pci_probe &= ~PCI_PROBE_MMCONF;
+	return 0;
+}
+
+static struct dmi_system_id __initdata dmi_bad_mcfg[] = {
+	/* Has broken MCFG table that makes the system hang when used */
+        {
+         .callback = disable_mcfg,
+         .ident = "Intel D3C5105 SDV",
+         .matches = {
+                     DMI_MATCH(DMI_BIOS_VENDOR, "Intel"),
+                     DMI_MATCH(DMI_BOARD_NAME, "D26928"),
+                     },
+         },
+         {}
+};
+
 void __init pci_mmcfg_init(void)
 {
 	int i;
 
-	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
+	dmi_check_system(dmi_bad_mcfg);
+
+	if ((pci_probe & (PCI_PROBE_MMCONF|PCI_PROBE_MMCONF_FORCE)) == 0)
 		return;
 
 	acpi_table_parse(ACPI_MCFG, acpi_parse_mcfg);