From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Date: Mon, 23 Mar 2020 17:26:03 -0700
Subject: PCI/ERR: Return status of pcie_do_recovery()
Git-commit: e8e5ff2aeec19ade42f0535f4b554a3f6e1a58f7
Patch-mainline: v5.7-rc1
References: bsc#1169263, jsc#SLE-10700, jsc#SLE-9457, jsc#SLE-12300

As per the DPC Enhancements ECN [1], sec 4.5.1, table 4-4, if the OS
supports Error Disconnect Recover (EDR), it must invalidate the software
state associated with child devices of the port without attempting to
access the child device hardware. In addition, if the OS supports DPC, it
must attempt to recover the child devices if the port implements the DPC
Capability. If the OS continues operation, the OS must inform the firmware
of the status of the recovery operation via the _OST method.

Return the result of pcie_do_recovery() so we can report it to firmware via
_OST.

[1] Downstream Port Containment Related Enhancements ECN, Jan 28, 2019,
    affecting PCI Firmware Specification, Rev. 3.2
    https://members.pcisig.com/wg/PCI-SIG/document/12888

Link: https://lore.kernel.org/r/eb60ec89448769349c6722954ffbf2de163155b5.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/pci/pci.h      |  5 +++--
 drivers/pci/pcie/err.c | 10 ++++++----
 2 files changed, 9 insertions(+), 6 deletions(-)

--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -497,8 +497,9 @@ static inline int pci_dev_specific_disab
 #endif
 
 /* PCI error reporting and recovery */
-void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
-		      pci_ers_result_t (*reset_link)(struct pci_dev *pdev));
+pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
+			enum pci_channel_state state,
+			pci_ers_result_t (*reset_link)(struct pci_dev *pdev));
 
 bool pcie_wait_for_link(struct pci_dev *pdev, bool active);
 #ifdef CONFIG_PCIEASPM
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -142,9 +142,9 @@ out:
 	return 0;
 }
 
-void pcie_do_recovery(struct pci_dev *dev,
-		      enum pci_channel_state state,
-		      pci_ers_result_t (*reset_link)(struct pci_dev *pdev))
+pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
+			enum pci_channel_state state,
+			pci_ers_result_t (*reset_link)(struct pci_dev *pdev))
 {
 	pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
 	struct pci_bus *bus;
@@ -196,11 +196,13 @@ void pcie_do_recovery(struct pci_dev *de
 	pci_aer_clear_device_status(dev);
 	pci_cleanup_aer_uncorrect_error_status(dev);
 	pci_info(dev, "AER: Device recovery successful\n");
-	return;
+	return status;
 
 failed:
 	pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT);
 
 	/* TODO: Should kernel panic here? */
 	pci_info(dev, "AER: Device recovery failed\n");
+
+	return status;
 }