[PATCH v4 05/10] PCI/AER: Apply function level reset to RCiEP on fatal error

[Sean V Kelley <sean.v.kelley@intel.com>]

From: Qiuxu Zhuo <qiuxu.zhuo@intel.com>

Attempt to do function level reset for an RCiEP associated with an
RCEC device on fatal error.

Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
---
 drivers/pci/pcie/err.c | 31 ++++++++++++++++++++++---------
 1 file changed, 22 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index e575fa6cee63..5380ecc41506 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -169,6 +169,17 @@ static void pci_bridge_walk(struct pci_dev *bridge, int (*cb)(struct pci_dev *,
 		cb(bridge, userdata);
 }
 
+static pci_ers_result_t flr_on_rciep(struct pci_dev *dev)
+{
+	if (!pcie_has_flr(dev))
+		return PCI_ERS_RESULT_NONE;
+
+	if (pcie_flr(dev))
+		return PCI_ERS_RESULT_DISCONNECT;
+
+	return PCI_ERS_RESULT_RECOVERED;
+}
+
 pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
 			pci_channel_state_t state,
 			pci_ers_result_t (*reset_subordinate_devices)(struct pci_dev *pdev))
@@ -195,15 +206,17 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
 	if (state == pci_channel_io_frozen) {
 		pci_bridge_walk(bridge, report_frozen_detected, &status);
 		if (type == PCI_EXP_TYPE_RC_END) {
-			pci_warn(dev, "link reset not possible for RCiEP\n");
-			status = PCI_ERS_RESULT_NONE;
-			goto failed;
-		}
-
-		status = reset_subordinate_devices(bridge);
-		if (status != PCI_ERS_RESULT_RECOVERED) {
-			pci_warn(dev, "subordinate device reset failed\n");
-			goto failed;
+			status = flr_on_rciep(dev);
+			if (status != PCI_ERS_RESULT_RECOVERED) {
+				pci_warn(dev, "function level reset failed\n");
+				goto failed;
+			}
+		} else {
+			status = reset_subordinate_devices(bridge);
+			if (status != PCI_ERS_RESULT_RECOVERED) {
+				pci_warn(dev, "subordinate device reset failed\n");
+				goto failed;
+			}
 		}
 	} else {
 		pci_bridge_walk(bridge, report_normal_detected, &status);
-- 
2.28.0