From: Jayachandran C <jchandra@broadcom.com>
Date: Wed, 16 Jan 2013 11:12:40 +0000 (+0000)
Subject: MIPS: PCI: Byteswap not needed in little-endian mode
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=a264b5e8dc3cae1b07cea010d6283be6e67b0209;p=linux-beck.git

MIPS: PCI: Byteswap not needed in little-endian mode

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>
---

diff --git a/arch/mips/pci/pci-xlp.c b/arch/mips/pci/pci-xlp.c
index 140557a20488..5077148bd67d 100644
--- a/arch/mips/pci/pci-xlp.c
+++ b/arch/mips/pci/pci-xlp.c
@@ -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;