PCI: allow multiple calls to pcim_pin_device()

Sanity check in pcim_pin_device() was too restrictive in that it didn't
allow multiple calls to the function, which is against the devres
philosohpy of fire-and-forget.  Track pinned status separately and allow
pinning multiple times.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Acked-by: NIan McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/pci/pci.c

@@ -757,7 +757,8 @@ int pci_enable_device(struct pci_dev *dev)
  * when a device is enabled using managed PCI device enable interface.
  */
 struct pci_devres {
-	unsigned int disable:1;
+	unsigned int enabled:1;
+	unsigned int pinned:1;
 	unsigned int orig_intx:1;
 	unsigned int restore_intx:1;
 	u32 region_mask;
@@ -781,7 +782,7 @@ static void pcim_release(struct device *gendev, void *res)
 	if (this->restore_intx)
 		pci_intx(dev, this->orig_intx);
 
-	if (this->disable)
+	if (this->enabled && !this->pinned)
 		pci_disable_device(dev);
 }
 
@@ -820,12 +821,12 @@ int pcim_enable_device(struct pci_dev *pdev)
 	dr = get_pci_dr(pdev);
 	if (unlikely(!dr))
 		return -ENOMEM;
-	WARN_ON(!!dr->disable);
+	WARN_ON(!!dr->enabled);
 
 	rc = pci_enable_device(pdev);
 	if (!rc) {
 		pdev->is_managed = 1;
-		dr->disable = 1;
+		dr->enabled = 1;
 	}
 	return rc;
 }
@@ -843,9 +844,9 @@ void pcim_pin_device(struct pci_dev *pdev)
 	struct pci_devres *dr;
 
 	dr = find_pci_dr(pdev);
-	WARN_ON(!dr || !dr->disable);
+	WARN_ON(!dr || !dr->enabled);
 	if (dr)
-		dr->disable = 0;
+		dr->pinned = 1;
 }
 
 /**
@@ -876,7 +877,7 @@ pci_disable_device(struct pci_dev *dev)
 
 	dr = find_pci_dr(dev);
 	if (dr)
-		dr->disable = 0;
+		dr->enabled = 0;
 
 	if (atomic_sub_return(1, &dev->enable_cnt) != 0)
 		return;