PCI/pciehp: Use PCI Express Capability accessors

Use PCI Express Capability access functions to simplify pciehp.
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Signed-off-by: NYijing Wang <wangyijing@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>

drivers/pci/hotplug/pciehp_acpi.c

@@ -81,16 +81,12 @@ static struct list_head __initdata dummy_slots = LIST_HEAD_INIT(dummy_slots);
 /* Dummy driver for dumplicate name detection */
 static int __init dummy_probe(struct pcie_device *dev)
 {
-	int pos;
 	u32 slot_cap;
 	acpi_handle handle;
 	struct dummy_slot *slot, *tmp;
 	struct pci_dev *pdev = dev->port;
 
-	pos = pci_pcie_cap(pdev);
-	if (!pos)
-		return -ENODEV;
-	pci_read_config_dword(pdev, pos + PCI_EXP_SLTCAP, &slot_cap);
+	pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
 	if (!slot)
 		return -ENOMEM;

drivers/pci/hotplug/pciehp_hpc.c

@@ -44,25 +44,25 @@
 static inline int pciehp_readw(struct controller *ctrl, int reg, u16 *value)
 {
 	struct pci_dev *dev = ctrl->pcie->port;
-	return pci_read_config_word(dev, pci_pcie_cap(dev) + reg, value);
+	return pcie_capability_read_word(dev, reg, value);
 }
 
 static inline int pciehp_readl(struct controller *ctrl, int reg, u32 *value)
 {
 	struct pci_dev *dev = ctrl->pcie->port;
-	return pci_read_config_dword(dev, pci_pcie_cap(dev) + reg, value);
+	return pcie_capability_read_dword(dev, reg, value);
 }
 
 static inline int pciehp_writew(struct controller *ctrl, int reg, u16 value)
 {
 	struct pci_dev *dev = ctrl->pcie->port;
-	return pci_write_config_word(dev, pci_pcie_cap(dev) + reg, value);
+	return pcie_capability_write_word(dev, reg, value);
 }
 
 static inline int pciehp_writel(struct controller *ctrl, int reg, u32 value)
 {
 	struct pci_dev *dev = ctrl->pcie->port;
-	return pci_write_config_dword(dev, pci_pcie_cap(dev) + reg, value);
+	return pcie_capability_write_dword(dev, reg, value);
 }
 
 /* Power Control Command */
@@ -855,10 +855,6 @@ struct controller *pcie_init(struct pcie_device *dev)
 		goto abort;
 	}
 	ctrl->pcie = dev;
-	if (!pci_pcie_cap(pdev)) {
-		ctrl_err(ctrl, "Cannot find PCI Express capability\n");
-		goto abort_ctrl;
-	}
 	if (pciehp_readl(ctrl, PCI_EXP_SLTCAP, &slot_cap)) {
 		ctrl_err(ctrl, "Cannot read SLOTCAP register\n");
 		goto abort_ctrl;