x86/amd-iommu: Fix boot crash with hidden PCI devices

Some PCIe cards ship with a PCI-PCIe bridge which is not
visible as a PCI device in Linux. But the device-id of the
bridge is present in the IOMMU tables which causes a boot
crash in the IOMMU driver.
This patch fixes by removing these cards from the IOMMU
handling. This is a pure -stable fix, a real fix to handle
this situation appriatly will follow for the next merge
window.

Cc: stable@kernel.org	# > 2.6.32
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 21 insertions, 1 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index b2c309b07427..7c3a95e54ec5 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -155,6 +155,10 @@ static int iommu_init_device(struct device *dev)
         pdev = pci_get_bus_and_slot(PCI_BUS(alias), alias & 0xff);
         if (pdev)
                 dev_data->alias = &pdev->dev;
+        else {
+                kfree(dev_data);
+                return -ENOTSUPP;
+        }
 
         atomic_set(&dev_data->bind, 0);
 
@@ -164,6 +168,20 @@ static int iommu_init_device(struct device *dev)
         return 0;
 }
 
+static void iommu_ignore_device(struct device *dev)
+{
+        u16 devid, alias;
+
+        devid = get_device_id(dev);
+        alias = amd_iommu_alias_table[devid];
+
+        memset(&amd_iommu_dev_table[devid], 0, sizeof(struct dev_table_entry));
+        memset(&amd_iommu_dev_table[alias], 0, sizeof(struct dev_table_entry));
+
+        amd_iommu_rlookup_table[devid] = NULL;
+        amd_iommu_rlookup_table[alias] = NULL;
+}
+
 static void iommu_uninit_device(struct device *dev)
 {
         kfree(dev->archdata.iommu);
@@ -193,7 +211,9 @@ int __init amd_iommu_init_devices(void)
                         continue;
 
                 ret = iommu_init_device(&pdev->dev);
-                if (ret)
+                if (ret == -ENOTSUPP)
+                        iommu_ignore_device(&pdev->dev);
+                else if (ret)
                         goto out_free;
         }