xen/pciback: avoid multiple entries in slot list

[cascardo/linux.git] / drivers / xen / xen-pciback / pci_stub.c

diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index 258b7c3..0179333 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;
@@ -478,6 +478,36 @@ static int __init pcistub_init_devices_late(void)
        return 0;
 }
 
+static void pcistub_device_id_add_list(struct pcistub_device_id *new,
+                                      int domain, int bus, unsigned int devfn)
+{
+       struct pcistub_device_id *pci_dev_id;
+       unsigned long flags;
+       int found = 0;
+
+       spin_lock_irqsave(&device_ids_lock, flags);
+
+       list_for_each_entry(pci_dev_id, &pcistub_device_ids, slot_list) {
+               if (pci_dev_id->domain == domain && pci_dev_id->bus == bus &&
+                   pci_dev_id->devfn == devfn) {
+                       found = 1;
+                       break;
+               }
+       }
+
+       if (!found) {
+               new->domain = domain;
+               new->bus = bus;
+               new->devfn = devfn;
+               list_add_tail(&new->slot_list, &pcistub_device_ids);
+       }
+
+       spin_unlock_irqrestore(&device_ids_lock, flags);
+
+       if (found)
+               kfree(new);
+}
+
 static int pcistub_seize(struct pci_dev *dev)
 {
        struct pcistub_device *psdev;
@@ -1012,7 +1042,6 @@ static inline int str_to_quirk(const char *buf, int *domain, int *bus, int
 static int pcistub_device_id_add(int domain, int bus, int slot, int func)
 {
        struct pcistub_device_id *pci_dev_id;
-       unsigned long flags;
        int rc = 0, devfn = PCI_DEVFN(slot, func);
 
        if (slot < 0) {
@@ -1042,16 +1071,10 @@ static int pcistub_device_id_add(int domain, int bus, int slot, int func)
        if (!pci_dev_id)
                return -ENOMEM;
 
-       pci_dev_id->domain = domain;
-       pci_dev_id->bus = bus;
-       pci_dev_id->devfn = devfn;
-
        pr_debug("wants to seize %04x:%02x:%02x.%d\n",
                 domain, bus, slot, func);
 
-       spin_lock_irqsave(&device_ids_lock, flags);
-       list_add_tail(&pci_dev_id->slot_list, &pcistub_device_ids);
-       spin_unlock_irqrestore(&device_ids_lock, flags);
+       pcistub_device_id_add_list(pci_dev_id, domain, bus, devfn);
 
        return 0;
 }