[PATCH] x86: Allow disabling early pci scans with pci=noearly or disallowing conf1
Some buggy systems can machine check when config space accesses
happen for some non existent devices. i386/x86-64 do some early
device scans that might trigger this. Allow pci=noearly to disable
this. Also when type 1 is disabling also don't do any early
accesses which are always type1.
This moves the pci= configuration parsing to be a early parameter.
I don't think this can break anything because it only changes
a single global that is only used by PCI.
Cc: gregkh@suse.de
Cc: Trammell Hudson <hudson@osresearch.net>
Signed-off-by: Andi Kleen <ak@suse.de>
diff --git a/arch/x86_64/kernel/vsmp.c b/arch/x86_64/kernel/vsmp.c
index 92f70c7..044e852 100644
--- a/arch/x86_64/kernel/vsmp.c
+++ b/arch/x86_64/kernel/vsmp.c
@@ -20,6 +20,9 @@
void *address;
unsigned int cap, ctl;
+ if (!early_pci_allowed())
+ return 0;
+
/* Check if we are running on a ScaleMP vSMP box */
if ((read_pci_config_16(0, 0x1f, 0, PCI_VENDOR_ID) != PCI_VENDOR_ID_SCALEMP) ||
(read_pci_config_16(0, 0x1f, 0, PCI_DEVICE_ID) != PCI_DEVICE_ID_SCALEMP_VSMP_CTL))