[RFC 19/27] PCI: dwc: Simplify config space handling

[Rob Herring <robh@kernel.org>]

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.

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>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Rob Herring <robh@kernel.org>
---
 drivers/pci/controller/dwc/pci-keystone.c     |  8 ---
 .../pci/controller/dwc/pcie-designware-host.c | 63 ++++++-------------
 drivers/pci/controller/dwc/pcie-designware.h  |  4 --
 3 files changed, 20 insertions(+), 55 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
index bdf4fe1fc822..e9028c98d6c0 100644
--- a/drivers/pci/controller/dwc/pci-keystone.c
+++ b/drivers/pci/controller/dwc/pci-keystone.c
@@ -873,16 +873,8 @@ static int __init ks_pcie_add_pcie_port(struct keystone_pcie *ks_pcie,
 	struct dw_pcie *pci = ks_pcie->pci;
 	struct pcie_port *pp = &pci->pp;
 	struct device *dev = &pdev->dev;
-	struct resource *res;
 	int ret;
 
-	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
-	pp->va_cfg0_base = devm_pci_remap_cfg_resource(dev, res);
-	if (IS_ERR(pp->va_cfg0_base))
-		return PTR_ERR(pp->va_cfg0_base);
-
-	pp->va_cfg1_base = pp->va_cfg0_base;
-
 	ret = dw_pcie_host_init(pp);
 	if (ret) {
 		dev_err(dev, "failed to initialize host\n");
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index a981e9de81d7..1ff4702595b6 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");
 	}
@@ -336,25 +334,22 @@ 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);
@@ -364,16 +359,6 @@ 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;
@@ -455,32 +440,24 @@ 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 (bus->parent->number == pp->root_bus_nr) {
+	if (bus->parent->number == pp->root_bus_nr)
 		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_size,
+				  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,
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 3d552ec8a850..2db6f52dfe81 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -170,13 +170,9 @@ struct pcie_port {
 	u64			cfg0_base;
 	void __iomem		*va_cfg0_base;
 	u32			cfg0_size;
-	u64			cfg1_base;
-	void __iomem		*va_cfg1_base;
-	u32			cfg1_size;
 	resource_size_t		io_base;
 	phys_addr_t		io_bus_addr;
 	u32			io_size;
-	struct resource		*cfg;
 	int			irq;
 	const struct dw_pcie_host_ops *ops;
 	int			msi_irq;
-- 
2.25.1