[PATCH v3 1/9] pci: Create pci_reset_bridge_secondary_bus()

Alex Williamson
2013-08-01T16:55:25Z

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>
---
drivers/pci/pci.c | 32 +++++++++++++++++++++++---------
include/linux/pci.h | 1 +
2 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index a599a6b..bfd629c 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3276,9 +3276,30 @@ 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)
@@ -3291,14 +3312,7 @@ 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 0fd1f15..35c1bc4 100644
--- 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);