[MIPS] Define MIPS_CPU_IRQ_BASE in generic header

The irq_base for {mips,rm7k,rm9k}_cpu_irq_init() are constant on all
platforms and are same value on most platforms (0 or 16, depends on
CONFIG_I8259).  Define them in asm-mips/mach-generic/irq.h and make
them customizable.  This will save a few cycle on each CPU interrupt.

A good side effect is removing some dependencies to MALTA in generic
SMTC code.

Although MIPS_CPU_IRQ_BASE is customizable, this patch changes irq
mappings on DDB5477, EMMA2RH and MIPS_SIM, since really customizing
them might cause some header dependency problem and there seems no
good reason to customize it.  So currently only VR41XX is using custom
MIPS_CPU_IRQ_BASE value, which is 0 regardless of CONFIG_I8259.

Testing this patch on those platforms is greatly appreciated.  Thank
you.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 26 insertions, 0 deletions

diff --git a/include/asm-mips/mach-generic/irq.h b/include/asm-mips/mach-generic/irq.h
index 500e10ff24de..91e6778907fe 100644
--- a/include/asm-mips/mach-generic/irq.h
+++ b/include/asm-mips/mach-generic/irq.h
@@ -8,6 +8,32 @@
 #ifndef __ASM_MACH_GENERIC_IRQ_H
 #define __ASM_MACH_GENERIC_IRQ_H
 
+#ifndef NR_IRQS
 #define NR_IRQS 128
+#endif
+
+#ifdef CONFIG_IRQ_CPU
+
+#ifndef MIPS_CPU_IRQ_BASE
+#ifdef CONFIG_I8259
+#define MIPS_CPU_IRQ_BASE 16
+#else
+#define MIPS_CPU_IRQ_BASE 0
+#endif /* CONFIG_I8259 */
+#endif
+
+#ifdef CONFIG_IRQ_CPU_RM7K
+#ifndef RM7K_CPU_IRQ_BASE
+#define RM7K_CPU_IRQ_BASE (MIPS_CPU_IRQ_BASE+8)
+#endif
+#endif
+
+#ifdef CONFIG_IRQ_CPU_RM9K
+#ifndef RM9K_CPU_IRQ_BASE
+#define RM9K_CPU_IRQ_BASE (MIPS_CPU_IRQ_BASE+12)
+#endif
+#endif
+
+#endif /* CONFIG_IRQ_CPU */
 
 #endif /* __ASM_MACH_GENERIC_IRQ_H */