[RFC 05/13] pci: Introduce pci_mmio_configure()

[Nicolas Saenz Julienne]

The function will traverse the pci device's bus hierarchy and set
the relevant MMIO access flags.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne at suse.de>
---
 drivers/pci/pci-driver.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index ec44a79e951a..554d91e7ec52 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -1596,6 +1596,31 @@ static int pci_dma_configure(struct device *dev)
 	return ret;
 }
 
+/**
+ * pci_mmio_configure - Setup MMIO configuration
+ * @dev: ptr to dev structure
+ *
+ * Function to update PCI devices's MMIO configuration using the same
+ * info from the OF node of host bridge's parent (if any).
+ */
+static int pci_mmio_configure(struct device *dev)
+{
+	struct device *bridge;
+	int ret = 0;
+
+	bridge = pci_get_host_bridge_device(to_pci_dev(dev));
+
+	dev_info(dev, "MMIO CONFIGURATION\n");
+	if (IS_ENABLED(CONFIG_OF) && bridge->parent &&
+	    bridge->parent->of_node) {
+		dev_info(dev, "MMIO CONFIGURATION, %pOF\n", bridge->parent->of_node);
+		ret = of_mmio_configure(dev, bridge->parent->of_node);
+	}
+
+	pci_put_host_bridge_device(bridge);
+	return ret;
+}
+
 struct bus_type pci_bus_type = {
 	.name		= "pci",
 	.match		= pci_bus_match,
@@ -1609,6 +1634,7 @@ struct bus_type pci_bus_type = {
 	.pm		= PCI_PM_OPS_PTR,
 	.num_vf		= pci_bus_num_vf,
 	.dma_configure	= pci_dma_configure,
+	.mmio_configure = pci_mmio_configure,
 };
 EXPORT_SYMBOL(pci_bus_type);
 
-- 
2.30.1