PCI: Fix build if quirks are not enabled

After commit b9c3b266411d27f1a6466c19d146d08db576bfea ("PCI: support
device-specific reset methods") the kernel build is broken if
CONFIG_PCI_QUIRKS is unset.

Fix this by moving pci_dev_specific_reset() to drivers/pci/quirks.c and
providing an empty replacement for !CONFIG_PCI_QUIRKS builds.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/pci/pci.c

@@ -2284,21 +2284,6 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
 	return 0;
 }
 
-static int pci_dev_specific_reset(struct pci_dev *dev, int probe)
-{
-	struct pci_dev_reset_methods *i;
-
-	for (i = pci_dev_reset_methods; i->reset; i++) {
-		if ((i->vendor == dev->vendor ||
-		     i->vendor == (u16)PCI_ANY_ID) &&
-		    (i->device == dev->device ||
-		     i->device == (u16)PCI_ANY_ID))
-			return i->reset(dev, probe);
-	}
-
-	return -ENOTTY;
-}
-
 static int pci_dev_reset(struct pci_dev *dev, int probe)
 {
 	int rc;

drivers/pci/pci.h

@@ -319,6 +319,6 @@ struct pci_dev_reset_methods {
 	int (*reset)(struct pci_dev *dev, int probe);
 };
 
-extern struct pci_dev_reset_methods pci_dev_reset_methods[];
+extern int pci_dev_specific_reset(struct pci_dev *dev, int probe);
 
 #endif /* DRIVERS_PCI_H */

drivers/pci/quirks.c

@@ -2684,14 +2684,31 @@ static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, int probe)
 
 #define PCI_DEVICE_ID_INTEL_82599_SFP_VF   0x10ed
 
-struct pci_dev_reset_methods pci_dev_reset_methods[] = {
+static const struct pci_dev_reset_methods pci_dev_reset_methods[] = {
 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82599_SFP_VF,
 		 reset_intel_82599_sfp_virtfn },
 	{ PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
 		reset_intel_generic_dev },
 	{ 0 }
 };
+
+int pci_dev_specific_reset(struct pci_dev *dev, int probe)
+{
+	struct pci_dev_reset_methods *i;
+
+	for (i = pci_dev_reset_methods; i->reset; i++) {
+		if ((i->vendor == dev->vendor ||
+		     i->vendor == (u16)PCI_ANY_ID) &&
+		    (i->device == dev->device ||
+		     i->device == (u16)PCI_ANY_ID))
+			return i->reset(dev, probe);
+	}
+
+	return -ENOTTY;
+}
+
 #else
 void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev) {}
+int pci_dev_specific_reset(struct pci_dev *dev, int probe) { return -ENOTTY; }
 #endif
 EXPORT_SYMBOL(pci_fixup_device);