PCI: Export pci_dev_lock()

Commit e3a9b121 ("PCI: Export pci_dev_trylock() and pci_dev_unlock()")
already exported pci_dev_trylock()/pci_dev_unlock() however in some
circumstances such as during error recovery it makes sense to block
waiting to get full access to the device so also export pci_dev_lock().

Link: https://lore.kernel.org/all/20210928181014.GA713179@bhelgaas/Acked-by: NPierre Morel <pmorel@linux.ibm.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NNiklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

drivers/pci/pci.c

@@ -5074,12 +5074,13 @@ static int pci_reset_bus_function(struct pci_dev *dev, bool probe)
 	return pci_parent_bus_reset(dev, probe);
 }
 
-static void pci_dev_lock(struct pci_dev *dev)
+void pci_dev_lock(struct pci_dev *dev)
 {
 	pci_cfg_access_lock(dev);
 	/* block PM suspend, driver probe, etc. */
 	device_lock(&dev->dev);
 }
+EXPORT_SYMBOL_GPL(pci_dev_lock);
 
 /* Return 1 on successful lock, 0 on contention */
 int pci_dev_trylock(struct pci_dev *dev)

include/linux/pci.h

@@ -1664,6 +1664,7 @@ void pci_cfg_access_lock(struct pci_dev *dev);
 bool pci_cfg_access_trylock(struct pci_dev *dev);
 void pci_cfg_access_unlock(struct pci_dev *dev);
 
+void pci_dev_lock(struct pci_dev *dev);
 int pci_dev_trylock(struct pci_dev *dev);
 void pci_dev_unlock(struct pci_dev *dev);