[PATCH] Fix restore of 64-bit PCI BAR's

For 64-bit BAR[i] only pci_dev->resource[i] is valid, ->resource[i+1]
slot is unused and contains zeroes in all fields.

So when we update a PCI BAR, all we need is just to check that we're
going to update a _valid_ resource.

Also make sure to write high bits - use "x >> 16 >> 16" (rather than the
simpler ">> 32") to avoid warnings on 32-bit architectures where we're
not going to have any high bits.

Signed-off-by: Linus Torvalds <[e-mail]>

drivers/pci/setup-res.c

···
 	u32 new, check, mask;
 	int reg;
 
+	/* Ignore resources for unimplemented BARs and unused resource slots
+	   for 64 bit BARs. */
+	if (!res->flags)
+		return;
+
 	pcibios_resource_to_bus(dev, &region, res);
 
 	pr_debug("  got res [%lx:%lx] bus [%lx:%lx] flags %lx for "
···
 
 	if ((new & (PCI_BASE_ADDRESS_SPACE|PCI_BASE_ADDRESS_MEM_TYPE_MASK)) ==
 	    (PCI_BASE_ADDRESS_SPACE_MEMORY|PCI_BASE_ADDRESS_MEM_TYPE_64)) {
-		new = 0; /* currently everyone zeros the high address */
+		new = region.start >> 16 >> 16;
 		pci_write_config_dword(dev, reg + 4, new);
 		pci_read_config_dword(dev, reg + 4, &check);
 		if (check != new) {