Add pcie_print_link_status() function for querying and verifying
a PCI device link status. The PCI speed and width are reported
in kernel log.
This provides a unified method for all PCI devices to
report status and issues, instead of each device reporting in a
different way, using different code.
Signed-off-by: Tal Gilboa <talgi@xxxxxxxxxxxx>
Reviewed-by: Tariq Toukan <tariqt@xxxxxxxxxxxx>
---
drivers/pci/pci.c | 25 +++++++++++++++++++++++++
include/linux/pci.h | 1 +
2 files changed, 26 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 48b9fd6..ac876c4 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5229,6 +5229,31 @@ int pcie_get_width_cap(struct pci_dev *dev, enum pcie_link_width *width)
EXPORT_SYMBOL(pcie_get_width_cap);
/**
+ * pcie_print_link_status - Reports the PCI device's link speed and width.
+ * @dev: PCI device to query
+ *
+ * This function checks whether the PCI device current speed and width are equal
+ * to the maximum PCI device capabilities.
+ */
+void pcie_print_link_status(struct pci_dev *dev)
+{
+ enum pcie_link_width width, width_cap;
+ enum pci_bus_speed speed, speed_cap;
+
+ pcie_get_speed_cap(dev, &speed_cap);
+ pcie_get_width_cap(dev, &width_cap);
+ pcie_get_minimum_link(dev, &speed, &width);
+
+ if (speed == speed_cap && width == width_cap)
+ pci_info(dev, "%s x%d link\n", PCIE_SPEED2STR(speed), width);
+ else
+ pci_info(dev, "%s x%d link (capable of %s x%d)\n",
+ PCIE_SPEED2STR(speed), width,
+ PCIE_SPEED2STR(speed_cap), width_cap);
+}
+EXPORT_SYMBOL(pcie_print_link_status);
+
+/**
* pci_select_bars - Make BAR mask from the type of resource
* @dev: the PCI device for which BAR mask is made
* @flags: resource type mask to be selected
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8242d3d..4a20870 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1085,6 +1085,7 @@ int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed,
enum pcie_link_width *width);
int pcie_get_speed_cap(struct pci_dev *dev, enum pci_bus_speed *speed);
int pcie_get_width_cap(struct pci_dev *dev, enum pcie_link_width *width);
+void pcie_print_link_status(struct pci_dev *dev);
int pcie_flr(struct pci_dev *dev);
int __pci_reset_function_locked(struct pci_dev *dev);
int pci_reset_function(struct pci_dev *dev);
--
1.8.3.1
