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PCI: hotplug: Use global PCI rescan-remove locking

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Multiple race conditions are possible between PCI hotplug and the generic
PCI bus rescan and device removal that can be triggered via sysfs.

To avoid those race conditions make PCI hotplug use global PCI
rescan-remove locking.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Rafael J. Wysocki
2014-01-14 12:03:14 -07:00
committed by Bjorn Helgaas
parent 5ef68e8867
commit c4ec84c7db
9 changed files with 83 additions and 19 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/pci/hotplug/cpci_hotplug_pci.c
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@@ -254,9 +254,12 @@ int __ref cpci_configure_slot(struct slot *slot)
{
struct pci_dev *dev;
struct pci_bus *parent;
int ret = 0;
dbg("%s - enter", __func__);
pci_lock_rescan_remove();
if (slot->dev == NULL) {
dbg("pci_dev null, finding %02x:%02x:%x",
slot->bus->number, PCI_SLOT(slot->devfn), PCI_FUNC(slot->devfn));
@@ -277,7 +280,8 @@ int __ref cpci_configure_slot(struct slot *slot)
slot->dev = pci_get_slot(slot->bus, slot->devfn);
if (slot->dev == NULL) {
err("Could not find PCI device for slot %02x", slot->number);
return -ENODEV;
ret = -ENODEV;
goto out;
}
}
parent = slot->dev->bus;
@@ -294,8 +298,10 @@ int __ref cpci_configure_slot(struct slot *slot)
pci_bus_add_devices(parent);
out:
pci_unlock_rescan_remove();
dbg("%s - exit", __func__);
return 0;
return ret;
}
int cpci_unconfigure_slot(struct slot* slot)
@@ -308,6 +314,8 @@ int cpci_unconfigure_slot(struct slot* slot)
return -ENODEV;
}
pci_lock_rescan_remove();
list_for_each_entry_safe(dev, temp, &slot->bus->devices, bus_list) {
if (PCI_SLOT(dev->devfn) != PCI_SLOT(slot->devfn))
continue;
@@ -318,6 +326,8 @@ int cpci_unconfigure_slot(struct slot* slot)
pci_dev_put(slot->dev);
slot->dev = NULL;
pci_unlock_rescan_remove();
dbg("%s - exit", __func__);
return 0;
}