[PATCH] mmconfig: fix unreachable_devices()

Currently, unreachable_devices() compares value of mmconfig and value
of conf1. But it doesn't check the device is reachable or not.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andi Kleen <ak@suse.de>

3 files changed, 15 insertions, 5 deletions

diff --git a/arch/i386/pci/mmconfig-shared.c b/arch/i386/pci/mmconfig-shared.c
index 4ea0852487a4..473db6257013 100644
--- a/arch/i386/pci/mmconfig-shared.c
+++ b/arch/i386/pci/mmconfig-shared.c
@@ -43,12 +43,14 @@ static void __init unreachable_devices(void)
                         if (val1 == 0xffffffff)
                                 continue;
 
-                        raw_pci_ops->read(0, bus, devfn, 0, 4, &val2);
-                        if (val1 != val2) {
-                                set_bit(i + 32 * bus, pci_mmcfg_fallback_slots);
-                                printk(KERN_NOTICE "PCI: No mmconfig possible"
-                                       " on device %02x:%02x\n", bus, i);
+                        if (pci_mmcfg_arch_reachable(0, bus, devfn)) {
+                                raw_pci_ops->read(0, bus, devfn, 0, 4, &val2);
+                                if (val1 == val2)
+                                        continue;
                         }
+                        set_bit(i + 32 * bus, pci_mmcfg_fallback_slots);
+                        printk(KERN_NOTICE "PCI: No mmconfig possible on device"
+                               " %02x:%02x\n", bus, i);
                 }
         }
 }
diff --git a/arch/i386/pci/mmconfig.c b/arch/i386/pci/mmconfig.c
index 11be089efd7d..bb1afd9e589d 100644
--- a/arch/i386/pci/mmconfig.c
+++ b/arch/i386/pci/mmconfig.c
@@ -136,6 +136,12 @@ static struct pci_raw_ops pci_mmcfg = {
         .write =        pci_mmcfg_write,
 };
 
+int __init pci_mmcfg_arch_reachable(unsigned int seg, unsigned int bus,
+                                    unsigned int devfn)
+{
+        return get_base_addr(seg, bus, devfn) != 0;
+}
+
 int __init pci_mmcfg_arch_init(void)
 {
         printk(KERN_INFO "PCI: Using MMCONFIG\n");
diff --git a/arch/i386/pci/pci.h b/arch/i386/pci/pci.h
index 2ce3d44b09d4..e58bae2076ad 100644
--- a/arch/i386/pci/pci.h
+++ b/arch/i386/pci/pci.h
@@ -101,4 +101,6 @@ extern void pcibios_sort(void);
 #define PCI_MMCFG_MAX_CHECK_BUS 16
 extern DECLARE_BITMAP(pci_mmcfg_fallback_slots, 32*PCI_MMCFG_MAX_CHECK_BUS);
 
+extern int __init pci_mmcfg_arch_reachable(unsigned int seg, unsigned int bus,
+                                           unsigned int devfn);
 extern int __init pci_mmcfg_arch_init(void);