[PATCH v9 09/15] PCI/ERR: Add pci_walk_bridge() to pcie_do_recovery()

Sean V Kelley
2020-10-16T00:13:23Z

From: Sean V Kelley <sean.v.kelley@intel.com>

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

[bhelgaas: fix kerneldoc]
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20201002184735.1229220-7-seanvk.dev@oregontracks.org
Signed-off-by: Sean V Kelley <sean.v.kelley@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
drivers/pci/pcie/err.c | 30 +++++++++++++++++++++++-------
1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index 931e75f2549d..8b53aecdb43d 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -146,13 +146,30 @@ static int report_resume(struct pci_dev *dev, void *data)
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);
--
2.28.0