MIPS: PCI: Byteswap not needed in little-endian mode
authorJayachandran C <jchandra@broadcom.com>
Wed, 16 Jan 2013 11:12:40 +0000 (11:12 +0000)
committerJohn Crispin <blogic@openwrt.org>
Sat, 16 Feb 2013 23:15:19 +0000 (00:15 +0100)
Rename function xlp_enable_pci_bswap() to xlp_config_pci_bswap(), which
is a better description for its functionality.  When compiled in
big-endian mode, xlp_config_pci_bswap() will configure the PCIe links
to byteswap.  In little-endian mode, no swap configuration is needed
for the PCIe controller, and the function is empty.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4802/
Signed-off-by: John Crispin <blogic@openwrt.org>
arch/mips/pci/pci-xlp.c

index 140557a20488fdcb049013de83cc66043a83e205..5077148bd67debc0985834016340c987743db7de 100644 (file)
@@ -191,7 +191,13 @@ int pcibios_plat_dev_init(struct pci_dev *dev)
        return 0;
 }
 
-static int xlp_enable_pci_bswap(void)
+/*
+ * If big-endian, enable hardware byteswap on the PCIe bridges.
+ * This will make both the SoC and PCIe devices behave consistently with
+ * readl/writel.
+ */
+#ifdef __BIG_ENDIAN
+static void xlp_config_pci_bswap(void)
 {
        uint64_t pciebase, sysbase;
        int node, i;
@@ -222,8 +228,11 @@ static int xlp_enable_pci_bswap(void)
                reg = nlm_read_bridge_reg(sysbase, BRIDGE_PCIEIO_LIMIT0 + i);
                nlm_write_pci_reg(pciebase, PCIE_BYTE_SWAP_IO_LIM, reg | 0xfff);
        }
-       return 0;
 }
+#else
+/* Swap configuration not needed in little-endian mode */
+static inline void xlp_config_pci_bswap(void) {}
+#endif /* __BIG_ENDIAN */
 
 static int __init pcibios_init(void)
 {
@@ -235,7 +244,7 @@ static int __init pcibios_init(void)
        ioport_resource.start =  0;
        ioport_resource.end   = ~0;
 
-       xlp_enable_pci_bswap();
+       xlp_config_pci_bswap();
        set_io_port_base(CKSEG1);
        nlm_pci_controller.io_map_base = CKSEG1;