[MIPS] MIPSsim: Move code away from the other MIPS Inc. BSP code.

It shares no code at all.  While at it also fix up the beginning bitrot.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/mipssim/sim_int.c b/arch/mips/mipssim/sim_int.c
new file mode 100644
index 0000000..d86b372
--- /dev/null
+++ b/arch/mips/mipssim/sim_int.c
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 1999, 2005 MIPS Technologies, Inc.  All rights reserved.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ */
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+#include <asm/mips-boards/simint.h>
+#include <asm/irq_cpu.h>
+
+static inline int clz(unsigned long x)
+{
+	__asm__ (
+	"	.set	push					\n"
+	"	.set	mips32					\n"
+	"	clz	%0, %1					\n"
+	"	.set	pop					\n"
+	: "=r" (x)
+	: "r" (x));
+
+	return x;
+}
+
+/*
+ * Version of ffs that only looks at bits 12..15.
+ */
+static inline unsigned int irq_ffs(unsigned int pending)
+{
+#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
+	return -clz(pending) + 31 - CAUSEB_IP;
+#else
+	unsigned int a0 = 7;
+	unsigned int t0;
+
+	t0 = s0 & 0xf000;
+	t0 = t0 < 1;
+	t0 = t0 << 2;
+	a0 = a0 - t0;
+	s0 = s0 << t0;
+
+	t0 = s0 & 0xc000;
+	t0 = t0 < 1;
+	t0 = t0 << 1;
+	a0 = a0 - t0;
+	s0 = s0 << t0;
+
+	t0 = s0 & 0x8000;
+	t0 = t0 < 1;
+	/* t0 = t0 << 2; */
+	a0 = a0 - t0;
+	/* s0 = s0 << t0; */
+
+	return a0;
+#endif
+}
+
+asmlinkage void plat_irq_dispatch(void)
+{
+	unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;
+	int irq;
+
+	irq = irq_ffs(pending);
+
+	if (irq > 0)
+		do_IRQ(MIPSCPU_INT_BASE + irq);
+	else
+		spurious_interrupt();
+}
+
+void __init arch_init_irq(void)
+{
+	mips_cpu_irq_init();
+}