xen/pciback: simplify pcistub device handling

The Xen pciback driver maintains a list of all its seized devices.
There are two functions searching the list for a specific device with
basically the same semantics just returning different structures in
case of a match.

Split out the search function.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index 258b7c3..79a9e4d 100644 (file)
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -149,13 +149,10 @@ static inline void pcistub_device_put(struct pcistub_device *psdev)
        kref_put(&psdev->kref, pcistub_device_release);
 }
 
-static struct pcistub_device *pcistub_device_find(int domain, int bus,
-                                                 int slot, int func)
+static struct pcistub_device *pcistub_device_find_locked(int domain, int bus,
+                                                        int slot, int func)
 {
-       struct pcistub_device *psdev = NULL;
-       unsigned long flags;
-
-       spin_lock_irqsave(&pcistub_devices_lock, flags);
+       struct pcistub_device *psdev;
 
        list_for_each_entry(psdev, &pcistub_devices, dev_list) {
                if (psdev->dev != NULL
@@ -163,15 +160,25 @@ static struct pcistub_device *pcistub_device_find(int domain, int bus,
                    && bus == psdev->dev->bus->number
                    && slot == PCI_SLOT(psdev->dev->devfn)
                    && func == PCI_FUNC(psdev->dev->devfn)) {
-                       pcistub_device_get(psdev);
-                       goto out;
+                       return psdev;
                }
        }
 
-       /* didn't find it */
-       psdev = NULL;
+       return NULL;
+}
+
+static struct pcistub_device *pcistub_device_find(int domain, int bus,
+                                                 int slot, int func)
+{
+       struct pcistub_device *psdev;
+       unsigned long flags;
+
+       spin_lock_irqsave(&pcistub_devices_lock, flags);
+
+       psdev = pcistub_device_find_locked(domain, bus, slot, func);
+       if (psdev)
+               pcistub_device_get(psdev);
 
-out:
        spin_unlock_irqrestore(&pcistub_devices_lock, flags);
        return psdev;
 }
@@ -207,16 +214,9 @@ struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev,
 
        spin_lock_irqsave(&pcistub_devices_lock, flags);
 
-       list_for_each_entry(psdev, &pcistub_devices, dev_list) {
-               if (psdev->dev != NULL
-                   && domain == pci_domain_nr(psdev->dev->bus)
-                   && bus == psdev->dev->bus->number
-                   && slot == PCI_SLOT(psdev->dev->devfn)
-                   && func == PCI_FUNC(psdev->dev->devfn)) {
-                       found_dev = pcistub_device_get_pci_dev(pdev, psdev);
-                       break;
-               }
-       }
+       psdev = pcistub_device_find_locked(domain, bus, slot, func);
+       if (psdev)
+               found_dev = pcistub_device_get_pci_dev(pdev, psdev);
 
        spin_unlock_irqrestore(&pcistub_devices_lock, flags);
        return found_dev;