Revert "x86/PCI: MMCONFIG: Check earlier for MMCONFIG region at address zero"

This reverts commit 07f9b61c3915e8eb156cb4461b3946736356ad02.

07f9b61c was intended to be a cleanup that didn't change anything, but in
fact, for systems without _CBA (which is almost everything), it broke
extended config space for domain 0 and all config space for other domains.

Reference: http://lkml.kernel.org/r/20131004011806.GE20450@dangermouse.emea.sgi.com
Reported-by: Hedi Berriche <hedi@sgi.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 5596c7bdd327b1af38138a3d32be36be3e21cb17..082e88129712b4eb9e2027852c890a02ff31a1c7 100644 (file)
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -700,7 +700,7 @@ int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
        if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
                return -ENODEV;
 
-       if (start > end || !addr)
+       if (start > end)
                return -EINVAL;
 
        mutex_lock(&pci_mmcfg_lock);
@@ -716,6 +716,11 @@ int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
                return -EEXIST;
        }
 
+       if (!addr) {
+               mutex_unlock(&pci_mmcfg_lock);
+               return -EINVAL;
+       }
+
        rc = -EBUSY;
        cfg = pci_mmconfig_alloc(seg, start, end, addr);
        if (cfg == NULL) {