From: Sean V Kelley <sean.v.kelley@intel.com>
Date: Fri, 20 Nov 2020 16:10:30 -0800
Subject: PCI/ERR: Add pci_walk_bridge() to pcie_do_recovery()
Git-commit: 05e9ae19ab83881a0f33025bd1288e41e552a34b
Patch-mainline: v5.11-rc1
References: bsc#1174426

Consolidate subordinate bus checks with pci_walk_bus() into
pci_walk_bridge() for walking below potentially AER affected bridges.

Link: https://lore.kernel.org/r/20201121001036.8560-10-sean.v.kelley@intel.com
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # non-native/no RCEC
Signed-off-by: Sean V Kelley <sean.v.kelley@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/pci/pcie/err.c |   30 +++++++++++++++++++++++-------
 1 file changed, 23 insertions(+), 7 deletions(-)

--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -142,13 +142,30 @@ out:
 	return 0;
 }
 
+/**
+ * pci_walk_bridge - walk bridges potentially AER affected
+ * @bridge:	bridge which may be a Port
+ * @cb:		callback to be called for each device found
+ * @userdata:	arbitrary pointer to be passed to callback
+ *
+ * If the device provided is a bridge, walk the subordinate bus, including
+ * any bridged devices on buses under this bus.  Call the provided callback
+ * on each device found.
+ */
+static void pci_walk_bridge(struct pci_dev *bridge,
+			    int (*cb)(struct pci_dev *, void *),
+			    void *userdata)
+{
+	if (bridge->subordinate)
+		pci_walk_bus(bridge->subordinate, cb, userdata);
+}
+
 pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
 		pci_channel_state_t state,
 		pci_ers_result_t (*reset_subordinates)(struct pci_dev *pdev))
 {
 	int type = pci_pcie_type(dev);
 	struct pci_dev *bridge;
-	struct pci_bus *bus;
 	pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
 
 	/*
@@ -161,23 +178,22 @@ pci_ers_result_t pcie_do_recovery(struct
 	else
 		bridge = pci_upstream_bridge(dev);
 
-	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);
+		pci_walk_bridge(bridge, report_frozen_detected, &status);
 		status = reset_subordinates(bridge);
 		if (status != PCI_ERS_RESULT_RECOVERED) {
 			pci_warn(bridge, "subordinate device reset failed\n");
 			goto failed;
 		}
 	} else {
-		pci_walk_bus(bus, report_normal_detected, &status);
+		pci_walk_bridge(bridge, report_normal_detected, &status);
 	}
 
 	if (status == PCI_ERS_RESULT_CAN_RECOVER) {
 		status = PCI_ERS_RESULT_RECOVERED;
 		pci_dbg(bridge, "broadcast mmio_enabled message\n");
-		pci_walk_bus(bus, report_mmio_enabled, &status);
+		pci_walk_bridge(bridge, report_mmio_enabled, &status);
 	}
 
 	if (status == PCI_ERS_RESULT_NEED_RESET) {
@@ -188,14 +204,14 @@ pci_ers_result_t pcie_do_recovery(struct
 		 */
 		status = PCI_ERS_RESULT_RECOVERED;
 		pci_dbg(bridge, "broadcast slot_reset message\n");
-		pci_walk_bus(bus, report_slot_reset, &status);
+		pci_walk_bridge(bridge, report_slot_reset, &status);
 	}
 
 	if (status != PCI_ERS_RESULT_RECOVERED)
 		goto failed;
 
 	pci_dbg(bridge, "broadcast resume message\n");
-	pci_walk_bus(bus, report_resume, &status);
+	pci_walk_bridge(bridge, report_resume, &status);
 
 	if (pcie_aer_is_native(bridge))
 		pci_aer_clear_device_status(bridge);