[PATCH v4 5/5] PCI: dwc: Save root bus for driver remove

[Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>]

Currently dwc host doesn't support the remove, but nothing prevent us
from supporting it. Save the root bus for clean up work in driver
remove code path.

After this patch, the dwc host users could implement its remove as:

static int foo_pcie_remove(struct platform_device *pdev)
{
	...
	pci_stop_root_bus(pp->root_bus);
	pci_remove_root_bus(pp->root_bus);
	dw_pcie_free_msi(pp);
	...
}

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>
Acked-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
---
 drivers/pci/controller/dwc/pcie-designware-host.c | 12 ++++++------
 drivers/pci/controller/dwc/pcie-designware.h      |  1 +
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index dcc7405aff9a..3e4169e738a5 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -341,7 +341,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
 	struct device_node *np = dev->of_node;
 	struct platform_device *pdev = to_platform_device(dev);
 	struct resource_entry *win, *tmp;
-	struct pci_bus *bus, *child;
+	struct pci_bus *child;
 	struct pci_host_bridge *bridge;
 	struct resource *cfg_res;
 	int ret;
@@ -496,18 +496,18 @@ int dw_pcie_host_init(struct pcie_port *pp)
 	if (ret)
 		goto err_free_msi;
 
-	bus = bridge->bus;
+	pp->root_bus = bridge->bus;
 
 	if (pp->ops->scan_bus)
 		pp->ops->scan_bus(pp);
 
-	pci_bus_size_bridges(bus);
-	pci_bus_assign_resources(bus);
+	pci_bus_size_bridges(pp->root_bus);
+	pci_bus_assign_resources(pp->root_bus);
 
-	list_for_each_entry(child, &bus->children, node)
+	list_for_each_entry(child, &pp->root_bus->children, node)
 		pcie_bus_configure_settings(child);
 
-	pci_bus_add_devices(bus);
+	pci_bus_add_devices(pp->root_bus);
 	return 0;
 
 err_free_msi:
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 6fb0a1879932..adff0c713665 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -182,6 +182,7 @@ struct pcie_port {
 	struct page		*msi_page;
 	u32			num_vectors;
 	u32			irq_mask[MAX_MSI_CTRLS];
+	struct pci_bus		*root_bus;
 	raw_spinlock_t		lock;
 	DECLARE_BITMAP(msi_irq_in_use, MAX_MSI_IRQS);
 };
-- 
2.20.1