PCI: Add pci_reset_bridge_secondary_bus()

Move the secondary bus reset code from pci_parent_bus_reset() into its own
function.  Export it as we'll later be calling it from hotplug controllers
and elsewhere.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e37fea6e178d2dab00d3334848d231117d525013..d46860898e1fb634aa1c1dde8b056ba7ce3d1956 100644 (file)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3215,9 +3215,30 @@ static int pci_pm_reset(struct pci_dev *dev, int probe)
        return 0;
 }
 
-static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
+/**
+ * pci_reset_bridge_secondary_bus - Reset the secondary bus on a PCI bridge.
+ * @dev: Bridge device
+ *
+ * Use the bridge control register to assert reset on the secondary bus.
+ * Devices on the secondary bus are left in power-on state.
+ */
+void pci_reset_bridge_secondary_bus(struct pci_dev *dev)
 {
        u16 ctrl;
+
+       pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &ctrl);
+       ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
+       pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
+       msleep(100);
+
+       ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
+       pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
+       msleep(100);
+}
+EXPORT_SYMBOL_GPL(pci_reset_bridge_secondary_bus);
+
+static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
+{
        struct pci_dev *pdev;
 
        if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self)
@@ -3230,14 +3251,7 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
        if (probe)
                return 0;
 
-       pci_read_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, &ctrl);
-       ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
-       pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl);
-       msleep(100);
-
-       ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
-       pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl);
-       msleep(100);
+       pci_reset_bridge_secondary_bus(dev->bus->self);
 
        return 0;
 }

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 0fd1f1582fa1cdf359b33f3cddeaa60026f492ac..35c1bc4909f371a7b0ff89669e01104587dfafdc 100644 (file)
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -924,6 +924,7 @@ int pcie_set_mps(struct pci_dev *dev, int mps);
 int __pci_reset_function(struct pci_dev *dev);
 int __pci_reset_function_locked(struct pci_dev *dev);
 int pci_reset_function(struct pci_dev *dev);
+void pci_reset_bridge_secondary_bus(struct pci_dev *dev);
 void pci_update_resource(struct pci_dev *dev, int resno);
 int __must_check pci_assign_resource(struct pci_dev *dev, int i);
 int __must_check pci_reassign_resource(struct pci_dev *dev, int i, resource_size_t add_size, resource_size_t align);