PCI: rockchip-ep: Improve rockchip_pcie_ep_unmap_addr()

There is no need to loop over all regions to find the memory window used
to map an address. We can use rockchip_ob_region() to determine the
region index, together with a check that the address passed as argument
is the address used to create the mapping. Furthermore, the
ob_region_map bitmap should also be checked to ensure that we are not
attempting to unmap an address that is not mapped.

Link: https://lore.kernel.org/r/20241017015849.190271-4-dlemoal@kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/controller/pcie-rockchip-ep.c

@@ -259,13 +259,9 @@ static void rockchip_pcie_ep_unmap_addr(struct pci_epc *epc, u8 fn, u8 vfn,
 {
 	struct rockchip_pcie_ep *ep = epc_get_drvdata(epc);
 	struct rockchip_pcie *rockchip = &ep->rockchip;
-	u32 r;
-
-	for (r = 0; r < ep->max_regions; r++)
-		if (ep->ob_addr[r] == addr)
-			break;
+	u32 r = rockchip_ob_region(addr);
 
-	if (r == ep->max_regions)
+	if (addr != ep->ob_addr[r] || !test_bit(r, &ep->ob_region_map))
 		return;
 
 	rockchip_pcie_clear_ep_ob_atu(rockchip, r);