[PATCH] Calgary IOMMU: fix reference counting of Calgary PCI devices

The pci_get_device() API decrements the reference count on the 'from'
parameter when it continues searching. Therefore, take a ref count on
Calgary bus when we initialize them in either translated or
non-translated mode.

Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Jon Mason <jdmason@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>

diff --git a/arch/x86_64/kernel/pci-calgary.c b/arch/x86_64/kernel/pci-calgary.c
index 6c5da1d813f33b84d336ac70faaec8988e6f5705..7302834718c8742522717f3fcc67b2815dc555cc 100644 (file)
--- a/arch/x86_64/kernel/pci-calgary.c
+++ b/arch/x86_64/kernel/pci-calgary.c
@@ -786,6 +786,7 @@ static inline unsigned int __init locate_register_space(struct pci_dev *dev)
 
 static int __init calgary_init_one_nontraslated(struct pci_dev *dev)
 {
+       pci_dev_get(dev);
        dev->sysdata = NULL;
        dev->bus->self = dev;
 
@@ -810,6 +811,7 @@ static int __init calgary_init_one(struct pci_dev *dev)
        if (ret)
                goto iounmap;
 
+       pci_dev_get(dev);
        dev->bus->self = dev;
        calgary_enable_translation(dev);
 
@@ -836,10 +838,9 @@ static int __init calgary_init(void)
                        calgary_init_one_nontraslated(dev);
                        continue;
                }
-               if (!bus_info[dev->bus->number].tce_space && !translate_empty_slots) {
-                       pci_dev_put(dev);
+               if (!bus_info[dev->bus->number].tce_space && !translate_empty_slots)
                        continue;
-               }
+
                ret = calgary_init_one(dev);
                if (ret)
                        goto error;
@@ -860,9 +861,10 @@ error:
                }
                if (!bus_info[dev->bus->number].tce_space && !translate_empty_slots)
                        continue;
+
                calgary_disable_translation(dev);
                calgary_free_bus(dev);
-               pci_dev_put(dev);
+               pci_dev_put(dev); /* Undo calgary_init_one()'s pci_dev_get() */
        }
 
        return ret;