PCI : add extremely specialized __pci_reenable_device for default resume

Original patch was posted as "PCI : Move pci_fixup_device and is_enabled".
This 3 of 3 patches does:

  - add __pci_reenable_device
    (recover former change of 1st patch)
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/pci/pci-driver.c

@@ -324,8 +324,7 @@ static int pci_default_resume(struct pci_dev *pci_dev)
 	/* restore the PCI config space */
 	pci_restore_state(pci_dev);
 	/* if the device was enabled before suspend, reenable */
-	if (atomic_read(&pci_dev->enable_cnt))
-		retval = pci_enable_device(pci_dev);
+	retval = __pci_reenable_device(pci_dev);
 	/* if the device was busmaster before the suspend, make it busmaster again */
 	if (pci_dev->is_busmaster)
 		pci_set_master(pci_dev);

drivers/pci/pci.c

@@ -676,6 +676,36 @@ pci_restore_state(struct pci_dev *dev)
 	return 0;
 }
 
+static int do_pci_enable_device(struct pci_dev *dev, int bars)
+{
+	int err;
+
+	err = pci_set_power_state(dev, PCI_D0);
+	if (err < 0 && err != -EIO)
+		return err;
+	err = pcibios_enable_device(dev, bars);
+	if (err < 0)
+		return err;
+	pci_fixup_device(pci_fixup_enable, dev);
+
+	return 0;
+}
+
+/**
+ * __pci_reenable_device - Resume abandoned device
+ * @dev: PCI device to be resumed
+ *
+ *  Note this function is a backend of pci_default_resume and is not supposed
+ *  to be called by normal code, write proper resume handler and use it instead.
+ */
+int
+__pci_reenable_device(struct pci_dev *dev)
+{
+	if (atomic_read(&dev->enable_cnt))
+		return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1);
+	return 0;
+}
+
 /**
  * pci_enable_device_bars - Initialize some of a device for use
  * @dev: PCI device to be initialized
@@ -693,15 +723,8 @@ pci_enable_device_bars(struct pci_dev *dev, int bars)
 	if (atomic_add_return(1, &dev->enable_cnt) > 1)
 		return 0;		/* already enabled */
 
-	err = pci_set_power_state(dev, PCI_D0);
-	if (err < 0 && err != -EIO)
-		goto err_out;
-	err = pcibios_enable_device(dev, bars);
+	err = do_pci_enable_device(dev, bars);
 	if (err < 0)
-		goto err_out;
-	pci_fixup_device(pci_fixup_enable, dev);
-
-err_out:
 		atomic_dec(&dev->enable_cnt);
 	return err;
 }

drivers/pci/pci.h

 /* Functions internal to the PCI core code */
 
+extern int __must_check __pci_reenable_device(struct pci_dev *);
 extern int pci_uevent(struct device *dev, char **envp, int num_envp,
 		      char *buffer, int buffer_size);
 extern int pci_create_sysfs_dev_files(struct pci_dev *pdev);