PCI: dwc: Simplify config space handling

The config space is divided in half for type 0 and type 1 accesses, but
this is pointless as there's only one iATU window which is
reconfigured on each access.

The only platform doing something custom is TI Keystone (surprise!).
It does its own mapping of the config space to avoid spliting the
config space and never actually uses va_cfg1_base as it has its own
config space accessors. With the splitting removed, Keystone can use the
default mapping of config space.

Link: https://lore.kernel.org/r/20200821035420.380495-20-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Murali Karicheri <m-karicheri2@ti.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jingoo Han <jingoohan1@gmail.com>
Cc: Gustavo Pimentel <gustavo.pimentel@synopsys.com>

1 files changed, 20 insertions, 43 deletions

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index b40aeae78809..38d7c89dbb21 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -308,10 +308,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
 
 	cfg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
 	if (cfg_res) {
-		pp->cfg0_size = resource_size(cfg_res) >> 1;
-		pp->cfg1_size = resource_size(cfg_res) >> 1;
+		pp->cfg0_size = resource_size(cfg_res);
 		pp->cfg0_base = cfg_res->start;
-		pp->cfg1_base = cfg_res->start + pp->cfg0_size;
 	} else if (!pp->va_cfg0_base) {
 		dev_err(dev, "Missing *config* reg space\n");
 	}
@@ -331,25 +329,22 @@ int dw_pcie_host_init(struct pcie_port *pp)
 			pp->io_base = pci_pio_to_address(win->res->start);
 			break;
 		case 0:
-			pp->cfg = win->res;
-			pp->cfg0_size = resource_size(pp->cfg) >> 1;
-			pp->cfg1_size = resource_size(pp->cfg) >> 1;
-			pp->cfg0_base = pp->cfg->start;
-			pp->cfg1_base = pp->cfg->start + pp->cfg0_size;
+			dev_err(dev, "Missing *config* reg space\n");
+			pp->cfg0_size = resource_size(win->res);
+			pp->cfg0_base = win->res->start;
+			if (!pci->dbi_base) {
+				pci->dbi_base = devm_pci_remap_cfgspace(dev,
+								pp->cfg0_base,
+								pp->cfg0_size);
+				if (!pci->dbi_base) {
+					dev_err(dev, "Error with ioremap\n");
+					return -ENOMEM;
+				}
+			}
 			break;
 		}
 	}
 
-	if (!pci->dbi_base) {
-		pci->dbi_base = devm_pci_remap_cfgspace(dev,
-						pp->cfg->start,
-						resource_size(pp->cfg));
-		if (!pci->dbi_base) {
-			dev_err(dev, "Error with ioremap\n");
-			return -ENOMEM;
-		}
-	}
-
 	if (!pp->va_cfg0_base) {
 		pp->va_cfg0_base = devm_pci_remap_cfgspace(dev,
 					pp->cfg0_base, pp->cfg0_size);
@@ -359,16 +354,6 @@ int dw_pcie_host_init(struct pcie_port *pp)
 		}
 	}
 
-	if (!pp->va_cfg1_base) {
-		pp->va_cfg1_base = devm_pci_remap_cfgspace(dev,
-						pp->cfg1_base,
-						pp->cfg1_size);
-		if (!pp->va_cfg1_base) {
-			dev_err(dev, "Error with ioremap\n");
-			return -ENOMEM;
-		}
-	}
-
 	ret = of_property_read_u32(np, "num-viewport", &pci->num_viewport);
 	if (ret)
 		pci->num_viewport = 2;
@@ -446,32 +431,24 @@ static void __iomem *dw_pcie_other_conf_map_bus(struct pci_bus *bus,
 						unsigned int devfn, int where)
 {
 	int type;
-	u32 busdev, cfg_size;
-	u64 cpu_addr;
-	void __iomem *va_cfg_base;
+	u32 busdev;
 	struct pcie_port *pp = bus->sysdata;
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 
 	busdev = PCIE_ATU_BUS(bus->number) | PCIE_ATU_DEV(PCI_SLOT(devfn)) |
 		 PCIE_ATU_FUNC(PCI_FUNC(devfn));
 
-	if (pci_is_root_bus(bus->parent)) {
+	if (pci_is_root_bus(bus->parent))
 		type = PCIE_ATU_TYPE_CFG0;
-		cpu_addr = pp->cfg0_base;
-		cfg_size = pp->cfg0_size;
-		va_cfg_base = pp->va_cfg0_base;
-	} else {
+	else
 		type = PCIE_ATU_TYPE_CFG1;
-		cpu_addr = pp->cfg1_base;
-		cfg_size = pp->cfg1_size;
-		va_cfg_base = pp->va_cfg1_base;
-	}
+
 
 	dw_pcie_prog_outbound_atu(pci, PCIE_ATU_REGION_INDEX1,
-				  type, cpu_addr,
-				  busdev, cfg_size);
+				  type, pp->cfg0_base,
+				  busdev, pp->cfg0_size);
 
-	return va_cfg_base + where;
+	return pp->va_cfg0_base + where;
 }
 
 static int dw_pcie_rd_other_conf(struct pci_bus *bus, unsigned int devfn,