[RFC 04/27] PCI: dwc: Add a default pci_ops.map_bus for root port

[Rob Herring <robh@kernel.org>]

The Designware root port config space is memory mapped accesses via the
DBI space by default. Add a common implementation
dw_pcie_own_conf_map_bus() for platforms to use.

Cc: Jingoo Han <jingoohan1@gmail.com>
Cc: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rob Herring <robh@kernel.org>
---
 drivers/pci/controller/dwc/pcie-designware-host.c | 11 +++++++++++
 drivers/pci/controller/dwc/pcie-designware.h      |  2 ++
 2 files changed, 13 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 7cd8c9528d4c..e9d31c341881 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -615,6 +615,17 @@ static int dw_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
 	return dw_pcie_wr_other_conf(pp, bus, devfn, where, size, val);
 }
 
+void __iomem *dw_pcie_own_conf_map_bus(struct pci_bus *bus, unsigned int devfn, int where)
+{
+	struct pcie_port *pp = bus->sysdata;
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+
+	if (PCI_SLOT(devfn) > 0)
+		return NULL;
+
+	return pci->dbi_base + where;
+}
+
 static struct pci_ops dw_pcie_ops = {
 	.read = dw_pcie_rd_conf,
 	.write = dw_pcie_wr_conf,
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index bad3cddab28e..dbe53e464e11 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -378,6 +378,8 @@ void dw_pcie_setup_rc(struct pcie_port *pp);
 int dw_pcie_host_init(struct pcie_port *pp);
 void dw_pcie_host_deinit(struct pcie_port *pp);
 int dw_pcie_allocate_domains(struct pcie_port *pp);
+void __iomem *dw_pcie_own_conf_map_bus(struct pci_bus *bus, unsigned int devfn,
+				       int where);
 #else
 static inline irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
 {
-- 
2.25.1