[PATCH 3.12 01/88] PCI/AER: Clear error status registers during enumeration and restore

[Jiri Slaby]

From: Taku Izumi <izumi.taku@xxxxxxxxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit b07461a8e45b7a62ef7fb46e4f6ada66f63406a8 upstream.

AER errors might be recorded when powering-on devices.  These errors can be
ignored, so firmware usually clears them before the OS enumerates devices.
However, firmware is not involved when devices are added via hotplug, so
the OS may discover power-up errors that should be ignored.  The same may
happen when powering up devices when resuming after suspend.

Clear the AER error status registers during enumeration and resume.

[bhelgaas: changelog, remove repetitive comments]
Signed-off-by: Taku Izumi <izumi.taku@xxxxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 drivers/pci/pci.c                  |  3 +++
 drivers/pci/pcie/aer/aerdrv_core.c | 28 ++++++++++++++++++++++++++++
 drivers/pci/probe.c                |  3 +++
 include/linux/aer.h                |  5 +++++
 4 files changed, 39 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 1e480a898d28..36c3e71d54b5 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -25,6 +25,7 @@
 #include <linux/pci_hotplug.h>
 #include <asm-generic/pci-bridge.h>
 #include <asm/setup.h>
+#include <linux/aer.h>
 #include "pci.h"
 
 const char *pci_power_names[] = {
@@ -1005,6 +1006,8 @@ void pci_restore_state(struct pci_dev *dev)
 	pci_restore_pcie_state(dev);
 	pci_restore_ats_state(dev);
 
+	pci_cleanup_aer_error_status_regs(dev);
+
 	pci_restore_config_space(dev);
 
 	pci_restore_pcix_state(dev);
diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c
index 28d4c0a0d31a..382eacfd5636 100644
--- a/drivers/pci/pcie/aer/aerdrv_core.c
+++ b/drivers/pci/pcie/aer/aerdrv_core.c
@@ -74,6 +74,34 @@ int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev)
 }
 EXPORT_SYMBOL_GPL(pci_cleanup_aer_uncorrect_error_status);
 
+int pci_cleanup_aer_error_status_regs(struct pci_dev *dev)
+{
+	int pos;
+	u32 status;
+	int port_type;
+
+	if (!pci_is_pcie(dev))
+		return -ENODEV;
+
+	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
+	if (!pos)
+		return -EIO;
+
+	port_type = pci_pcie_type(dev);
+	if (port_type == PCI_EXP_TYPE_ROOT_PORT) {
+		pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &status);
+		pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, status);
+	}
+
+	pci_read_config_dword(dev, pos + PCI_ERR_COR_STATUS, &status);
+	pci_write_config_dword(dev, pos + PCI_ERR_COR_STATUS, status);
+
+	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
+	pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
+
+	return 0;
+}
+
 /**
  * add_error_device - list device to be handled
  * @e_info: pointer to error info
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 53b23ff577b4..4e415a85da29 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -10,6 +10,7 @@
 #include <linux/module.h>
 #include <linux/cpumask.h>
 #include <linux/pci-aspm.h>
+#include <linux/aer.h>
 #include <asm-generic/pci-bridge.h>
 #include "pci.h"
 
@@ -1356,6 +1357,8 @@ static void pci_init_capabilities(struct pci_dev *dev)
 
 	/* Enable ACS P2P upstream forwarding */
 	pci_enable_acs(dev);
+
+	pci_cleanup_aer_error_status_regs(dev);
 }
 
 void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
diff --git a/include/linux/aer.h b/include/linux/aer.h
index 4dbaa7081530..1cbc28eb1f90 100644
--- a/include/linux/aer.h
+++ b/include/linux/aer.h
@@ -38,6 +38,7 @@ struct aer_capability_regs {
 int pci_enable_pcie_error_reporting(struct pci_dev *dev);
 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);
 #else
 static inline int pci_enable_pcie_error_reporting(struct pci_dev *dev)
 {
@@ -51,6 +52,10 @@ static inline int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev)
 {
 	return -EINVAL;
 }
+static inline int pci_cleanup_aer_error_status_regs(struct pci_dev *dev)
+{
+	return -EINVAL;
+}
 #endif
 
 void cper_print_aer(struct pci_dev *dev, int cper_severity,
-- 
2.9.1