PCI/ERR: Use "bridge" for clarity in pcie_do_recovery()

mainline inclusion
from mainline-v5.11-rc1
commit 0791721d
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I51U4T
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0791721d800790e6e533bd8467df67f0dc4f2fec

--------------------------------------------------------------------------

pcie_do_recovery() may be called with "dev" being either a bridge (Root
Port or Switch Downstream Port) or an Endpoint.  The bulk of the function
deals with the bridge, so if we start with an Endpoint, we reset "dev" to
be the bridge leading to it.

For clarity, replace "dev" in the body of the function with "bridge".  No
functional change intended.

Link: https://lore.kernel.org/r/20201121001036.8560-8-sean.v.kelley@intel.com
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # non-native/no RCEC
Signed-off-by: NSean V Kelley <sean.v.kelley@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJiefeng Ou <oujiefeng@h-partners.com>
Reviewed-by: NKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: NJay Fang <f.fangjian@huawei.com>
Reviewed-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/pci/pcie/err.c

@@ -151,24 +151,27 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
 		pci_ers_result_t (*reset_subordinates)(struct pci_dev *pdev))
 {
 	int type = pci_pcie_type(dev);
-	pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
+	struct pci_dev *bridge;
 	struct pci_bus *bus;
+	pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
 
 	/*
-	 * Error recovery runs on all subordinates of the first downstream port.
-	 * If the downstream port detected the error, it is cleared at the end.
+	 * Error recovery runs on all subordinates of the bridge.  If the
+	 * bridge detected the error, it is cleared at the end.
 	 */
 	if (!(type == PCI_EXP_TYPE_ROOT_PORT ||
 	      type == PCI_EXP_TYPE_DOWNSTREAM))
-		dev = pci_upstream_bridge(dev);
-	bus = dev->subordinate;
+		bridge = pci_upstream_bridge(dev);
+	else
+		bridge = dev;
 
-	pci_dbg(dev, "broadcast error_detected message\n");
+	bus = bridge->subordinate;
+	pci_dbg(bridge, "broadcast error_detected message\n");
 	if (state == pci_channel_io_frozen) {
 		pci_walk_bus(bus, report_frozen_detected, &status);
-		status = reset_subordinates(dev);
+		status = reset_subordinates(bridge);
 		if (status != PCI_ERS_RESULT_RECOVERED) {
-			pci_warn(dev, "subordinate device reset failed\n");
+			pci_warn(bridge, "subordinate device reset failed\n");
 			goto failed;
 		}
 	} else {
@@ -177,7 +180,7 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
 
 	if (status == PCI_ERS_RESULT_CAN_RECOVER) {
 		status = PCI_ERS_RESULT_RECOVERED;
-		pci_dbg(dev, "broadcast mmio_enabled message\n");
+		pci_dbg(bridge, "broadcast mmio_enabled message\n");
 		pci_walk_bus(bus, report_mmio_enabled, &status);
 	}
 
@@ -188,27 +191,27 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
 		 * drivers' slot_reset callbacks?
 		 */
 		status = PCI_ERS_RESULT_RECOVERED;
-		pci_dbg(dev, "broadcast slot_reset message\n");
+		pci_dbg(bridge, "broadcast slot_reset message\n");
 		pci_walk_bus(bus, report_slot_reset, &status);
 	}
 
 	if (status != PCI_ERS_RESULT_RECOVERED)
 		goto failed;
 
-	pci_dbg(dev, "broadcast resume message\n");
+	pci_dbg(bridge, "broadcast resume message\n");
 	pci_walk_bus(bus, report_resume, &status);
 
-	if (pcie_aer_is_native(dev))
-		pcie_clear_device_status(dev);
-	pci_aer_clear_nonfatal_status(dev);
-	pci_info(dev, "device recovery successful\n");
+	if (pcie_aer_is_native(bridge))
+		pcie_clear_device_status(bridge);
+	pci_aer_clear_nonfatal_status(bridge);
+	pci_info(bridge, "device recovery successful\n");
 	return status;
 
 failed:
-	pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT);
+	pci_uevent_ers(bridge, PCI_ERS_RESULT_DISCONNECT);
 
 	/* TODO: Should kernel panic here? */
-	pci_info(dev, "device recovery failed\n");
+	pci_info(bridge, "device recovery failed\n");
 
 	return status;
 }