MIPS: Loongson: Add basic Loongson 2F support

Loongson 2F has built-in DDR2 and PCI-X controller. The PCI-X controller
has a programming interface similiar to the the FPGA northbridge used on
Loongson 2E.

The main differences between Loongson 2E and Loongson 2F include:

1. Loongson 2F has an extra address window configuration module, which
   is used to map CPU address space to DDR or PCI address space, or map
   the PCI-DMA address space to DDR or LIO address space.

2. Loongson 2F supports 8 levels of software configurable CPu frequency
   which can be configured in the LOONGSON_CHIPCFG0 register.  The coming
   cpufreq and standby support are based on this feature.

Loongson.h abstracts the modules and corresponding methods are abstracted.

Add other Loongson-2F-specific source code including gcc 4.4 support, PCI
memory space, PCI IO space, DMA address.

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/loongson/common/bonito-irq.c b/arch/mips/loongson/common/bonito-irq.c
index a1cbd11..2dc2a4c 100644
--- a/arch/mips/loongson/common/bonito-irq.c
+++ b/arch/mips/loongson/common/bonito-irq.c
@@ -12,6 +12,7 @@
  *  option) any later version.
  */
 #include <linux/interrupt.h>
+#include <linux/compiler.h>
 
 #include <loongson.h>
 
@@ -35,7 +36,7 @@
 	.unmask	= bonito_irq_enable,
 };
 
-static struct irqaction dma_timeout_irqaction = {
+static struct irqaction __maybe_unused dma_timeout_irqaction = {
 	.handler	= no_action,
 	.name		= "dma_timeout",
 };
@@ -47,5 +48,7 @@
 	for (i = LOONGSON_IRQ_BASE; i < LOONGSON_IRQ_BASE + 32; i++)
 		set_irq_chip_and_handler(i, &bonito_irq_type, handle_level_irq);
 
+#ifdef CONFIG_CPU_LOONGSON2E
 	setup_irq(LOONGSON_IRQ_BASE + 10, &dma_timeout_irqaction);
+#endif
 }