[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>

5 files changed, 14 insertions, 1 deletions

diff --git a/arch/x86_64/kernel/aperture.c b/arch/x86_64/kernel/aperture.c
index f851e1f9c82a..b487396c4c5b 100644
--- a/arch/x86_64/kernel/aperture.c
+++ b/arch/x86_64/kernel/aperture.c
@@ -212,7 +212,7 @@ void __init iommu_hole_init(void)
         u64 aper_base, last_aper_base = 0;
         int valid_agp = 0;
 
-        if (iommu_aperture_disabled || !fix_aperture)
+        if (iommu_aperture_disabled || !fix_aperture || !early_pci_allowed())
                 return;
 
         printk("Checking aperture...\n"); 
diff --git a/arch/x86_64/kernel/early-quirks.c b/arch/x86_64/kernel/early-quirks.c
index d637cff1c4b1..208e38a372c1 100644
--- a/arch/x86_64/kernel/early-quirks.c
+++ b/arch/x86_64/kernel/early-quirks.c
@@ -82,6 +82,10 @@ static struct chipset early_qrk[] = {
 void __init early_quirks(void)
 {
         int num, slot, func;
+
+        if (!early_pci_allowed())
+                return;
+
         /* Poor man's PCI discovery */
         for (num = 0; num < 32; num++) {
                 for (slot = 0; slot < 32; slot++) {
diff --git a/arch/x86_64/kernel/pci-calgary.c b/arch/x86_64/kernel/pci-calgary.c
index 466588f95601..cfb09b07ae99 100644
--- a/arch/x86_64/kernel/pci-calgary.c
+++ b/arch/x86_64/kernel/pci-calgary.c
@@ -924,6 +924,9 @@ void __init detect_calgary(void)
         if (swiotlb || no_iommu || iommu_detected)
                 return;
 
+        if (!early_pci_allowed())
+                return;
+
         specified_table_size = determine_tce_table_size(end_pfn * PAGE_SIZE);
 
         for (bus = 0; bus < MAX_PHB_BUS_NUM; bus++) {
diff --git a/arch/x86_64/kernel/vsmp.c b/arch/x86_64/kernel/vsmp.c
index 92f70c74965f..044e852bd25e 100644
--- a/arch/x86_64/kernel/vsmp.c
+++ b/arch/x86_64/kernel/vsmp.c
@@ -20,6 +20,9 @@ static int __init vsmp_init(void)
         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))
diff --git a/arch/x86_64/mm/k8topology.c b/arch/x86_64/mm/k8topology.c
index 7c45c2d2b8b2..5cf594f9230d 100644
--- a/arch/x86_64/mm/k8topology.c
+++ b/arch/x86_64/mm/k8topology.c
@@ -54,6 +54,9 @@ int __init k8_scan_nodes(unsigned long start, unsigned long end)
 
         nodes_clear(nodes_parsed);
 
+        if (!early_pci_allowed())
+                return -1;
+
         nb = find_northbridge(); 
         if (nb < 0) 
                 return nb;