PCI: Convert Downstream Port Containment driver to use devm_* functions

Use the device resource management (devm) interfaces so we don't need to
explicitly release resources on failure paths or when the driver is
removed.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Keith Busch <keith.busch@intel.com>

drivers/pci/pcie/pcie-dpc.c

@@ -89,7 +89,7 @@ static int dpc_probe(struct pcie_device *dev)
 	int status;
 	u16 ctl, cap;
 
-	dpc = kzalloc(sizeof(*dpc), GFP_KERNEL);
+	dpc = devm_kzalloc(&dev->device, sizeof(*dpc), GFP_KERNEL);
 	if (!dpc)
 		return -ENOMEM;
 
@@ -98,11 +98,12 @@ static int dpc_probe(struct pcie_device *dev)
 	INIT_WORK(&dpc->work, interrupt_event_handler);
 	set_service_data(dev, dpc);
 
-	status = request_irq(dev->irq, dpc_irq, IRQF_SHARED, "pcie-dpc", dpc);
+	status = devm_request_irq(&dev->device, dev->irq, dpc_irq, IRQF_SHARED,
+				  "pcie-dpc", dpc);
 	if (status) {
 		dev_warn(&dev->device, "request IRQ%d failed: %d\n", dev->irq,
 			 status);
-		goto out;
+		return status;
 	}
 
 	pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CAP, &cap);
@@ -117,9 +118,6 @@ static int dpc_probe(struct pcie_device *dev)
 		FLAG(cap, PCI_EXP_DPC_CAP_SW_TRIGGER), (cap >> 8) & 0xf,
 		FLAG(cap, PCI_EXP_DPC_CAP_DL_ACTIVE));
 	return status;
- out:
-	kfree(dpc);
-	return status;
 }
 
 static void dpc_remove(struct pcie_device *dev)
@@ -131,9 +129,6 @@ static void dpc_remove(struct pcie_device *dev)
 	pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl);
 	ctl &= ~(PCI_EXP_DPC_CTL_EN_NONFATAL | PCI_EXP_DPC_CTL_INT_EN);
 	pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl);
-
-	free_irq(dev->irq, dpc);
-	kfree(dpc);
 }
 
 static struct pcie_port_service_driver dpcdriver = {