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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
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18
drivers/pci/hotplug/shpchp_pci.c
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@@ -40,7 +40,9 @@ int __ref shpchp_configure_device(struct slot *p_slot)
struct controller *ctrl = p_slot->ctrl;
struct pci_dev *bridge = ctrl->pci_dev;
struct pci_bus *parent = bridge->subordinate;
int num;
int num, ret = 0;
pci_lock_rescan_remove();
dev = pci_get_slot(parent, PCI_DEVFN(p_slot->device, 0));
if (dev) {
@@ -48,13 +50,15 @@ int __ref shpchp_configure_device(struct slot *p_slot)
"at %04x:%02x:%02x, cannot hot-add\n", pci_name(dev),
pci_domain_nr(parent), p_slot->bus, p_slot->device);
pci_dev_put(dev);
return -EINVAL;
ret = -EINVAL;
goto out;
}
num = pci_scan_slot(parent, PCI_DEVFN(p_slot->device, 0));
if (num == 0) {
ctrl_err(ctrl, "No new device found\n");
return -ENODEV;
ret = -ENODEV;
goto out;
}
list_for_each_entry(dev, &parent->devices, bus_list) {
@@ -75,7 +79,9 @@ int __ref shpchp_configure_device(struct slot *p_slot)
pci_bus_add_devices(parent);
return 0;
out:
pci_unlock_rescan_remove();
return ret;
}
int shpchp_unconfigure_device(struct slot *p_slot)
@@ -89,6 +95,8 @@ int shpchp_unconfigure_device(struct slot *p_slot)
ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:%02x\n",
__func__, pci_domain_nr(parent), p_slot->bus, p_slot->device);
pci_lock_rescan_remove();
list_for_each_entry_safe(dev, temp, &parent->devices, bus_list) {
if (PCI_SLOT(dev->devfn) != p_slot->device)
continue;
@@ -108,6 +116,8 @@ int shpchp_unconfigure_device(struct slot *p_slot)
pci_stop_and_remove_bus_device(dev);
pci_dev_put(dev);
}
pci_unlock_rescan_remove();
return rc;
}