PCI: mvebu: Check for valid ports

Some mvebu ports do not have to be initialized. So skip these uninitialized
mvebu ports in every port iteration function to prevent access to unmapped
memory or dereferencing NULL pointers. Uninitialized mvebu port has base
address set to NULL.

Link: https://lore.kernel.org/r/20211125124605.25915-2-pali@kernel.orgSigned-off-by: NPali Rohár <pali@kernel.org>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>

drivers/pci/controller/pci-mvebu.c

@@ -606,6 +606,9 @@ static struct mvebu_pcie_port *mvebu_pcie_find_port(struct mvebu_pcie *pcie,
 	for (i = 0; i < pcie->nports; i++) {
 		struct mvebu_pcie_port *port = &pcie->ports[i];
 
+		if (!port->base)
+			continue;
+
 		if (bus->number == 0 && port->devfn == devfn)
 			return port;
 		if (bus->number != 0 &&
@@ -781,6 +784,8 @@ static int mvebu_pcie_suspend(struct device *dev)
 	pcie = dev_get_drvdata(dev);
 	for (i = 0; i < pcie->nports; i++) {
 		struct mvebu_pcie_port *port = pcie->ports + i;
+		if (!port->base)
+			continue;
 		port->saved_pcie_stat = mvebu_readl(port, PCIE_STAT_OFF);
 	}
 
@@ -795,6 +800,8 @@ static int mvebu_pcie_resume(struct device *dev)
 	pcie = dev_get_drvdata(dev);
 	for (i = 0; i < pcie->nports; i++) {
 		struct mvebu_pcie_port *port = pcie->ports + i;
+		if (!port->base)
+			continue;
 		mvebu_writel(port, port->saved_pcie_stat, PCIE_STAT_OFF);
 		mvebu_pcie_setup_hw(port);
 	}