PCI: designware: Use iATU0 for cfg and IO, iATU1 for MEM

Most transactions' type are cfg0 and MEM, so the current iATU usage is not
balanced: iATU0 is hot while iATU1 is rarely used.

Refactor the iATU usage so we use iATU0 for cfg and IO and iATU1 for MEM.
This allocation idea comes from Minghuan Lian
<Minghuan.Lian@freescale.com>:

[bhelgaas: use link with Message-ID]
Link: http://lkml.kernel.org/r/1429091315-31891-3-git-send-email-Minghuan.Lian@freescale.com
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Pratyush Anand <pratyush.anand@gmail.com>

drivers/pci/host/pcie-designware.c

@@ -510,6 +510,11 @@ int dw_pcie_host_init(struct pcie_port *pp)
 	if (pp->ops->host_init)
 		pp->ops->host_init(pp);
 
+	if (!pp->ops->rd_other_conf)
+		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX1,
+					  PCIE_ATU_TYPE_MEM, pp->mem_mod_base,
+					  pp->mem_bus_addr, pp->mem_size);
+
 	dw_pcie_wr_own_conf(pp, PCI_BASE_ADDRESS_0, 4, 0);
 
 	/* program correct class for RC */
@@ -535,66 +540,70 @@ int dw_pcie_host_init(struct pcie_port *pp)
 static int dw_pcie_rd_other_conf(struct pcie_port *pp, struct pci_bus *bus,
 		u32 devfn, int where, int size, u32 *val)
 {
-	int ret = PCIBIOS_SUCCESSFUL;
-	u32 address, busdev;
+	int ret, type;
+	u32 address, busdev, cfg_size;
+	u64 cpu_addr;
+	void __iomem *va_cfg_base;
 
 	busdev = PCIE_ATU_BUS(bus->number) | PCIE_ATU_DEV(PCI_SLOT(devfn)) |
 		 PCIE_ATU_FUNC(PCI_FUNC(devfn));
 	address = where & ~0x3;
 
 	if (bus->parent->number == pp->root_bus_nr) {
-		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
-					  PCIE_ATU_TYPE_CFG0, pp->cfg0_mod_base,
-					  busdev, pp->cfg0_size);
-		ret = dw_pcie_cfg_read(pp->va_cfg0_base + address, where, size,
-				val);
-		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
-					  PCIE_ATU_TYPE_MEM, pp->mem_mod_base,
-					  pp->mem_bus_addr, pp->mem_size);
+		type = PCIE_ATU_TYPE_CFG0;
+		cpu_addr = pp->cfg0_mod_base;
+		cfg_size = pp->cfg0_size;
+		va_cfg_base = pp->va_cfg0_base;
 	} else {
-		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX1,
-					  PCIE_ATU_TYPE_CFG1, pp->cfg1_mod_base,
-					  busdev, pp->cfg1_size);
-		ret = dw_pcie_cfg_read(pp->va_cfg1_base + address, where, size,
-				val);
-		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX1,
-					  PCIE_ATU_TYPE_IO, pp->io_mod_base,
-					  pp->io_bus_addr, pp->io_size);
+		type = PCIE_ATU_TYPE_CFG1;
+		cpu_addr = pp->cfg1_mod_base;
+		cfg_size = pp->cfg1_size;
+		va_cfg_base = pp->va_cfg1_base;
 	}
 
+	dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
+				  type, cpu_addr,
+				  busdev, cfg_size);
+	ret = dw_pcie_cfg_read(va_cfg_base + address, where, size, val);
+	dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
+				  PCIE_ATU_TYPE_IO, pp->io_mod_base,
+				  pp->io_bus_addr, pp->io_size);
+
 	return ret;
 }
 
 static int dw_pcie_wr_other_conf(struct pcie_port *pp, struct pci_bus *bus,
 		u32 devfn, int where, int size, u32 val)
 {
-	int ret = PCIBIOS_SUCCESSFUL;
-	u32 address, busdev;
+	int ret, type;
+	u32 address, busdev, cfg_size;
+	u64 cpu_addr;
+	void __iomem *va_cfg_base;
 
 	busdev = PCIE_ATU_BUS(bus->number) | PCIE_ATU_DEV(PCI_SLOT(devfn)) |
 		 PCIE_ATU_FUNC(PCI_FUNC(devfn));
 	address = where & ~0x3;
 
 	if (bus->parent->number == pp->root_bus_nr) {
-		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
-					  PCIE_ATU_TYPE_CFG0, pp->cfg0_mod_base,
-					  busdev, pp->cfg0_size);
-		ret = dw_pcie_cfg_write(pp->va_cfg0_base + address, where, size,
-				val);
-		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
-					  PCIE_ATU_TYPE_MEM, pp->mem_mod_base,
-					  pp->mem_bus_addr, pp->mem_size);
+		type = PCIE_ATU_TYPE_CFG0;
+		cpu_addr = pp->cfg0_mod_base;
+		cfg_size = pp->cfg0_size;
+		va_cfg_base = pp->va_cfg0_base;
 	} else {
-		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX1,
-					  PCIE_ATU_TYPE_CFG1, pp->cfg1_mod_base,
-					  busdev, pp->cfg1_size);
-		ret = dw_pcie_cfg_write(pp->va_cfg1_base + address, where, size,
-				val);
-		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX1,
-					  PCIE_ATU_TYPE_IO, pp->io_mod_base,
-					  pp->io_bus_addr, pp->io_size);
+		type = PCIE_ATU_TYPE_CFG1;
+		cpu_addr = pp->cfg1_mod_base;
+		cfg_size = pp->cfg1_size;
+		va_cfg_base = pp->va_cfg1_base;
 	}
 
+	dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
+				  type, cpu_addr,
+				  busdev, cfg_size);
+	ret = dw_pcie_cfg_write(va_cfg_base + address, where, size, val);
+	dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
+				  PCIE_ATU_TYPE_IO, pp->io_mod_base,
+				  pp->io_bus_addr, pp->io_size);
+
 	return ret;
 }