[PATCH 8/8] PCI: dw: Add support for PCI_PROBE_ONLY/PCI_REASSIGN_ALL_BUS flags

From: Jonathan Chocron
Date: Thu Jul 11 2019 - 10:58:02 EST


This basically aligns the usage of PCI_PROBE_ONLY and
PCI_REASSIGN_ALL_BUS in dw_pcie_host_init() with the logic in
pci_host_common_probe().

Now it will be possible to control via the devicetree whether to just
probe the PCI bus (in cases where FW already configured it) or to fully
configure it.

Signed-off-by: Jonathan Chocron <jonnyc@xxxxxxxxxx>
---
.../pci/controller/dwc/pcie-designware-host.c | 23 +++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index d2ca748e4c85..0a294d8aa21a 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -342,6 +342,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
if (!bridge)
return -ENOMEM;

+ of_pci_check_probe_only();
+
ret = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff,
&bridge->windows, &pp->io_base);
if (ret)
@@ -474,6 +476,10 @@ int dw_pcie_host_init(struct pcie_port *pp)

pp->root_bus_nr = pp->busn->start;

+ /* Do not reassign bus nums if probe only */
+ if (!pci_has_flag(PCI_PROBE_ONLY))
+ pci_add_flags(PCI_REASSIGN_ALL_BUS);
+
bridge->dev.parent = dev;
bridge->sysdata = pp;
bridge->busnr = pp->root_bus_nr;
@@ -490,11 +496,20 @@ int dw_pcie_host_init(struct pcie_port *pp)
if (pp->ops->scan_bus)
pp->ops->scan_bus(pp);

- pci_bus_size_bridges(pp->root_bus);
- pci_bus_assign_resources(pp->root_bus);
+ /*
+ * We insert PCI resources into the iomem_resource and
+ * ioport_resource trees in either pci_bus_claim_resources()
+ * or pci_bus_assign_resources().
+ */
+ if (pci_has_flag(PCI_PROBE_ONLY)) {
+ pci_bus_claim_resources(pp->root_bus);
+ } else {
+ pci_bus_size_bridges(pp->root_bus);
+ pci_bus_assign_resources(pp->root_bus);

- list_for_each_entry(child, &pp->root_bus->children, node)
- pcie_bus_configure_settings(child);
+ list_for_each_entry(child, &pp->root_bus->children, node)
+ pcie_bus_configure_settings(child);
+ }

pci_bus_add_devices(pp->root_bus);
return 0;
--
2.17.1