PCI: dwc: Allow overriding bridge pci_ops

In preparation to allow drivers to set their own root and child pci_ops
instead of using the DWC specific config space ops, we need to make
the pci_host_bridge pointer available and move setting the bridge->ops
and bridge->child_ops pointer to before the .host_init() hook.

Link: https://lore.kernel.org/r/20200821035420.380495-4-robh@kernel.orgSigned-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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>

drivers/pci/controller/dwc/pcie-designware-host.c

@@ -344,6 +344,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
 	if (!bridge)
 		return -ENOMEM;
 
+	pp->bridge = bridge;
+
 	/* Get the I/O and memory ranges from DT */
 	resource_list_for_each_entry(win, &bridge->windows) {
 		switch (resource_type(win->res)) {
@@ -445,6 +447,10 @@ int dw_pcie_host_init(struct pcie_port *pp)
 		}
 	}
 
+	/* Set default bus ops */
+	bridge->ops = &dw_pcie_ops;
+	bridge->child_ops = &dw_pcie_ops;
+
 	if (pp->ops->host_init) {
 		ret = pp->ops->host_init(pp);
 		if (ret)
@@ -452,7 +458,6 @@ int dw_pcie_host_init(struct pcie_port *pp)
 	}
 
 	bridge->sysdata = pp;
-	bridge->ops = &dw_pcie_ops;
 
 	ret = pci_scan_root_bus_bridge(bridge);
 	if (ret)
@@ -654,11 +659,11 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
 	dw_pcie_writel_dbi(pci, PCI_COMMAND, val);
 
 	/*
-	 * If the platform provides ->rd_other_conf, it means the platform
-	 * uses its own address translation component rather than ATU, so
-	 * we should not program the ATU here.
+	 * If the platform provides its own child bus config accesses, it means
+	 * the platform uses its own address translation component rather than
+	 * ATU, so we should not program the ATU here.
 	 */
-	if (!pp->ops->rd_other_conf) {
+	if (pp->bridge->child_ops == &dw_pcie_ops && !pp->ops->rd_other_conf) {
 		dw_pcie_prog_outbound_atu(pci, PCIE_ATU_REGION_INDEX0,
 					  PCIE_ATU_TYPE_MEM, pp->mem_base,
 					  pp->mem_bus_addr, pp->mem_size);

drivers/pci/controller/dwc/pcie-designware.h

@@ -200,6 +200,7 @@ struct pcie_port {
 	u32			num_vectors;
 	u32			irq_mask[MAX_MSI_CTRLS];
 	struct pci_bus		*root_bus;
+	struct pci_host_bridge  *bridge;
 	raw_spinlock_t		lock;
 	DECLARE_BITMAP(msi_irq_in_use, MAX_MSI_IRQS);
 };