ACPI: Disable MSI on request of FADT

The ACPI spec defines the bit and Microsoft uses it,
so Linux must use it too.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/pci/pci-acpi.c

@@ -317,6 +317,10 @@ static int __init acpi_pci_init(void)
 {
 	int ret;
 
+	if (acpi_gbl_FADT.boot_flags & BAF_MSI_NOT_SUPPORTED) {
+		printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
+		pci_no_msi();
+	}
 	ret = register_acpi_bus_type(&acpi_pci_bus);
 	if (ret)
 		return 0;

include/acpi/actbl.h

@@ -276,6 +276,7 @@ enum acpi_prefered_pm_profiles {
 
 #define BAF_LEGACY_DEVICES              0x0001
 #define BAF_8042_KEYBOARD_CONTROLLER    0x0002
+#define BAF_MSI_NOT_SUPPORTED           0x0008
 
 #define FADT2_REVISION_ID               3
 #define FADT2_MINUS_REVISION_ID         2