--- zzzz-none-000/linux-3.10.107/arch/mips/dec/setup.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/mips/dec/setup.c	2021-02-04 17:41:59.000000000 +0000
@@ -12,17 +12,20 @@
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/irqnr.h>
 #include <linux/module.h>
 #include <linux/param.h>
+#include <linux/percpu-defs.h>
 #include <linux/sched.h>
 #include <linux/spinlock.h>
 #include <linux/types.h>
 #include <linux/pm.h>
-#include <linux/irq.h>
 
 #include <asm/bootinfo.h>
 #include <asm/cpu.h>
 #include <asm/cpu-features.h>
+#include <asm/cpu-type.h>
 #include <asm/irq.h>
 #include <asm/irq_cpu.h>
 #include <asm/mipsregs.h>
@@ -65,7 +68,7 @@
 /*
  * IRQ routing and priority tables.  Priorites are set as follows:
  *
- *		KN01	KN230	KN02	KN02-BA KN02-CA KN03
+ *		KN01	KN230	KN02	KN02-BA	KN02-CA	KN03
  *
  * MEMORY	CPU	CPU	CPU	ASIC	CPU	CPU
  * RTC		CPU	CPU	CPU	ASIC	CPU	CPU
@@ -97,6 +100,7 @@
 	{ { .i = ~0 }, { .p = asic_intr_unimplemented } },
 };
 int cpu_fpu_mask = DEC_CPU_IRQ_MASK(DEC_CPU_INR_FPU);
+int *fpu_kstat_irq;
 
 static struct irqaction ioirq = {
 	.handler = no_action,
@@ -413,7 +417,7 @@
 
 /*
  * Machine-specific initialisation for KN02-BA, aka DS5000/1xx
- * (xx = 20, 25, 33), aka 3min.	 Also applies to KN04(-BA), aka
+ * (xx = 20, 25, 33), aka 3min.  Also applies to KN04(-BA), aka
  * DS5000/150, aka 4min.
  */
 static int kn02ba_interrupt[DEC_NR_INTS] __initdata = {
@@ -748,10 +752,21 @@
 		cpu_fpu_mask = 0;
 		dec_interrupt[DEC_IRQ_FPU] = -1;
 	}
+	/* Free the halt interrupt unused on R4k systems.  */
+	if (current_cpu_type() == CPU_R4000SC ||
+	    current_cpu_type() == CPU_R4400SC)
+		dec_interrupt[DEC_IRQ_HALT] = -1;
 
 	/* Register board interrupts: FPU and cascade. */
-	if (dec_interrupt[DEC_IRQ_FPU] >= 0)
-		setup_irq(dec_interrupt[DEC_IRQ_FPU], &fpuirq);
+	if (dec_interrupt[DEC_IRQ_FPU] >= 0 && cpu_has_fpu) {
+		struct irq_desc *desc_fpu;
+		int irq_fpu;
+
+		irq_fpu = dec_interrupt[DEC_IRQ_FPU];
+		setup_irq(irq_fpu, &fpuirq);
+		desc_fpu = irq_to_desc(irq_fpu);
+		fpu_kstat_irq = this_cpu_ptr(desc_fpu->kstat_irqs);
+	}
 	if (dec_interrupt[DEC_IRQ_CASCADE] >= 0)
 		setup_irq(dec_interrupt[DEC_IRQ_CASCADE], &ioirq);