PCI: dwc: Add unroll iATU space support to dw_pcie_disable_atu()

dw_pcie_disable_atu() was introduced by f8aed6ec ("PCI: dwc:
designware: Add EP mode support") and supported only the viewport version
of the iATU CSRs.

DW PCIe IP cores v4.80a and newer also support unrolled iATU/eDMA space.
Callers of dw_pcie_disable_atu(), including pci_epc_ops.clear_bar(),
pci_epc_ops.unmap_addr(), and dw_pcie_setup_rc(), don't work correctly when
it is enabled.

Add dw_pcie_disable_atu() support for controllers with unrolled iATU CSRs
enabled.

[bhelgaas: commit log]
Fixes: f8aed6ec ("PCI: dwc: designware: Add EP mode support")
Link: https://lore.kernel.org/r/20220624143428.8334-3-Sergey.Semin@baikalelectronics.ruTested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>

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

@@ -491,7 +491,7 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, u8 func_no, int index,
 void dw_pcie_disable_atu(struct dw_pcie *pci, int index,
 			 enum dw_pcie_region_type type)
 {
-	int region;
+	u32 region;
 
 	switch (type) {
 	case DW_PCIE_REGION_INBOUND:
@@ -504,8 +504,18 @@ void dw_pcie_disable_atu(struct dw_pcie *pci, int index,
 		return;
 	}
 
-	dw_pcie_writel_dbi(pci, PCIE_ATU_VIEWPORT, region | index);
-	dw_pcie_writel_dbi(pci, PCIE_ATU_CR2, ~(u32)PCIE_ATU_ENABLE);
+	if (pci->iatu_unroll_enabled) {
+		if (region == PCIE_ATU_REGION_INBOUND) {
+			dw_pcie_writel_ib_unroll(pci, index, PCIE_ATU_UNR_REGION_CTRL2,
+						 ~(u32)PCIE_ATU_ENABLE);
+		} else {
+			dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_REGION_CTRL2,
+						 ~(u32)PCIE_ATU_ENABLE);
+		}
+	} else {
+		dw_pcie_writel_dbi(pci, PCIE_ATU_VIEWPORT, region | index);
+		dw_pcie_writel_dbi(pci, PCIE_ATU_CR2, ~(u32)PCIE_ATU_ENABLE);
+	}
 }
 
 int dw_pcie_wait_for_link(struct dw_pcie *pci)