Merge branch 'pci/controller/al'

- Check IORESOURCE_BUS existence to avoid NULL pointer dereference
  (Aleksandr Mishin)

* pci/controller/al:
  PCI: al: Check IORESOURCE_BUS existence during probe

Author: bjorn-helgaas

drivers/pci/controller/dwc/pcie-al.c

@@ -242,18 +242,24 @@ static struct pci_ops al_child_pci_ops = {
 	.write = pci_generic_config_write,
 };
 
-static void al_pcie_config_prepare(struct al_pcie *pcie)
+static int al_pcie_config_prepare(struct al_pcie *pcie)
 {
 	struct al_pcie_target_bus_cfg *target_bus_cfg;
 	struct dw_pcie_rp *pp = &pcie->pci->pp;
 	unsigned int ecam_bus_mask;
+	struct resource_entry *ft;
 	u32 cfg_control_offset;
+	struct resource *bus;
 	u8 subordinate_bus;
 	u8 secondary_bus;
 	u32 cfg_control;
 	u32 reg;
-	struct resource *bus = resource_list_first_type(&pp->bridge->windows, IORESOURCE_BUS)->res;
 
+	ft = resource_list_first_type(&pp->bridge->windows, IORESOURCE_BUS);
+	if (!ft)
+		return -ENODEV;
+
+	bus = ft->res;
 	target_bus_cfg = &pcie->target_bus_cfg;
 
 	ecam_bus_mask = (pcie->ecam_size >> PCIE_ECAM_BUS_SHIFT) - 1;
@@ -287,6 +293,8 @@ static void al_pcie_config_prepare(struct al_pcie *pcie)
 	       FIELD_PREP(CFG_CONTROL_SEC_BUS_MASK, secondary_bus);
 
 	al_pcie_controller_writel(pcie, cfg_control_offset, reg);
+
+	return 0;
 }
 
 static int al_pcie_host_init(struct dw_pcie_rp *pp)
@@ -305,7 +313,9 @@ static int al_pcie_host_init(struct dw_pcie_rp *pp)
 	if (rc)
 		return rc;
 
-	al_pcie_config_prepare(pcie);
+	rc = al_pcie_config_prepare(pcie);
+	if (rc)
+		return rc;
 
 	return 0;
 }