PCI: hotplug: Use global PCI rescan-remove locking

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>

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/pci/hotplug/ibmphp_core.c b/drivers/pci/hotplug/ibmphp_core.c
index efdc13adbe41..cf3ac1e4b099 100644
--- a/drivers/pci/hotplug/ibmphp_core.c
+++ b/drivers/pci/hotplug/ibmphp_core.c
@@ -718,6 +718,8 @@ static void ibm_unconfigure_device(struct pci_func *func)
                                         func->device, func->function);
         debug("func->device << 3 | 0x0  = %x\n", func->device << 3 | 0x0);
 
+        pci_lock_rescan_remove();
+
         for (j = 0; j < 0x08; j++) {
                 temp = pci_get_bus_and_slot(func->busno, (func->device << 3) | j);
                 if (temp) {
@@ -725,7 +727,10 @@ static void ibm_unconfigure_device(struct pci_func *func)
                         pci_dev_put(temp);
                 }
         }
+
         pci_dev_put(func->dev);
+
+        pci_unlock_rescan_remove();
 }
 
 /*
@@ -780,6 +785,8 @@ static int ibm_configure_device(struct pci_func *func)
         int flag = 0;   /* this is to make sure we don't double scan the bus,
                                         for bridged devices primarily */
 
+        pci_lock_rescan_remove();
+
         if (!(bus_structure_fixup(func->busno)))
                 flag = 1;
         if (func->dev == NULL)
@@ -789,7 +796,7 @@ static int ibm_configure_device(struct pci_func *func)
         if (func->dev == NULL) {
                 struct pci_bus *bus = pci_find_bus(0, func->busno);
                 if (!bus)
-                        return 0;
+                        goto out;
 
                 num = pci_scan_slot(bus,
                                 PCI_DEVFN(func->device, func->function));
@@ -800,7 +807,7 @@ static int ibm_configure_device(struct pci_func *func)
                                 PCI_DEVFN(func->device, func->function));
                 if (func->dev == NULL) {
                         err("ERROR... : pci_dev still NULL\n");
-                        return 0;
+                        goto out;
                 }
         }
         if (!(flag) && (func->dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)) {
@@ -810,6 +817,8 @@ static int ibm_configure_device(struct pci_func *func)
                         pci_bus_add_devices(child);
         }
 
+ out:
+        pci_unlock_rescan_remove();
         return 0;
 }