From 7ab92e89bf8b0a93f0d53b6d83270e4cd0f7c563 Mon Sep 17 00:00:00 2001
From: Bjorn Helgaas <bhelgaas@google.com>
Date: Thu, 19 Jul 2018 17:55:58 -0500
Subject: [PATCH] PCI/AER: Clear only ERR_FATAL status bits during fatal recovery
Git-commit: 7ab92e89bf8b0a93f0d53b6d83270e4cd0f7c563
Patch-mainline: v4.19-rc1
References: bsc#1161561

During recovery from fatal errors, we previously called
pci_cleanup_aer_uncorrect_error_status(), which cleared *all* uncorrectable
error status bits (both ERR_FATAL and ERR_NONFATAL).

Instead, call a new pci_aer_clear_fatal_status() that clears only the
ERR_FATAL bits (as indicated by the PCI_ERR_UNCOR_SEVER register).

Based-on-patch-by: Oza Pawandeep <poza@codeaurora.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/pci/pcie/aer/aerdrv_core.c |   17 +++++++++++++++++
 drivers/pci/pcie/err.c             |    2 +-
 include/linux/aer.h                |    2 ++
 3 files changed, 20 insertions(+), 1 deletion(-)

--- a/drivers/pci/pcie/aer/aerdrv_core.c
+++ b/drivers/pci/pcie/aer/aerdrv_core.c
@@ -70,6 +70,23 @@ int pci_cleanup_aer_uncorrect_error_stat
 }
 EXPORT_SYMBOL_GPL(pci_cleanup_aer_uncorrect_error_status);
 
+void pci_aer_clear_fatal_status(struct pci_dev *dev)
+{
+	int pos;
+	u32 status, sev;
+
+	pos = dev->aer_cap;
+	if (!pos)
+		return;
+
+	/* Clear status bits for ERR_FATAL errors only */
+	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
+	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &sev);
+	status &= sev;
+	if (status)
+		pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
+}
+
 int pci_cleanup_aer_error_status_regs(struct pci_dev *dev)
 {
 	int pos;
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -262,7 +262,7 @@ void pcie_do_fatal_recovery(struct pci_d
 		 * do error recovery on all subordinates of the bridge instead
 		 * of the bridge and clear the error status of the bridge.
 		 */
-		pci_cleanup_aer_uncorrect_error_status(dev);
+		pci_aer_clear_fatal_status(dev);
 	}
 
 	if (result == PCI_ERS_RESULT_RECOVERED) {
--- a/include/linux/aer.h
+++ b/include/linux/aer.h
@@ -45,6 +45,7 @@ int pci_enable_pcie_error_reporting(stru
 int pci_disable_pcie_error_reporting(struct pci_dev *dev);
 int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev);
 int pci_cleanup_aer_error_status_regs(struct pci_dev *dev);
+void pci_aer_clear_fatal_status(struct pci_dev *dev);
 #else
 static inline int pci_enable_pcie_error_reporting(struct pci_dev *dev)
 {
@@ -62,6 +63,7 @@ static inline int pci_cleanup_aer_error_
 {
 	return -EINVAL;
 }
+static inline void pci_aer_clear_fatal_status(struct pci_dev *dev) { }
 #endif
 
 void cper_print_aer(struct pci_dev *dev, int aer_severity,