PCI/ERR: Add pci_walk_bridge() to pcie_do_recovery()

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>

diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index 931e75f..8b53aec 100644 (file)
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -146,13 +146,30 @@ 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;
 
        /*
@@ -165,23 +182,22 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
        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) {
@@ -192,14 +208,14 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
                 */
                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))
                pcie_clear_device_status(bridge);