--- zzzz-none-000/linux-3.10.107/arch/xtensa/kernel/traps.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/xtensa/kernel/traps.c	2021-02-04 17:41:59.000000000 +0000
@@ -62,6 +62,7 @@
 
 extern void do_illegal_instruction (struct pt_regs*);
 extern void do_interrupt (struct pt_regs*);
+extern void do_nmi(struct pt_regs *);
 extern void do_unaligned_user (struct pt_regs*);
 extern void do_multihit (struct pt_regs*, unsigned long);
 extern void do_page_fault (struct pt_regs*, unsigned long);
@@ -101,9 +102,8 @@
 #if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
 #ifdef CONFIG_XTENSA_UNALIGNED_USER
 { EXCCAUSE_UNALIGNED,		USER,	   fast_unaligned },
-#else
-{ EXCCAUSE_UNALIGNED,		0,	   do_unaligned_user },
 #endif
+{ EXCCAUSE_UNALIGNED,		0,	   do_unaligned_user },
 { EXCCAUSE_UNALIGNED,		KRNL,	   fast_unaligned },
 #endif
 #ifdef CONFIG_MMU
@@ -147,6 +147,9 @@
 #if XTENSA_HAVE_COPROCESSOR(7)
 COPROCESSOR(7),
 #endif
+#if XTENSA_FAKE_NMI
+{ EXCCAUSE_MAPPED_NMI,			0,		do_nmi },
+#endif
 { EXCCAUSE_MAPPED_DEBUG,		0,		do_debug },
 { -1, -1, 0 }
 
@@ -157,7 +160,7 @@
  * 2. it is a temporary memory buffer for the exception handlers.
  */
 
-unsigned long exc_table[EXC_TABLE_SIZE/4];
+DEFINE_PER_CPU(unsigned long, exc_table[EXC_TABLE_SIZE/4]);
 
 void die(const char*, struct pt_regs*, long);
 
@@ -200,6 +203,28 @@
 
 extern void do_IRQ(int, struct pt_regs *);
 
+#if XTENSA_FAKE_NMI
+
+irqreturn_t xtensa_pmu_irq_handler(int irq, void *dev_id);
+
+DEFINE_PER_CPU(unsigned long, nmi_count);
+
+void do_nmi(struct pt_regs *regs)
+{
+	struct pt_regs *old_regs;
+
+	if ((regs->ps & PS_INTLEVEL_MASK) < LOCKLEVEL)
+		trace_hardirqs_off();
+
+	old_regs = set_irq_regs(regs);
+	nmi_enter();
+	++*this_cpu_ptr(&nmi_count);
+	xtensa_pmu_irq_handler(0, NULL);
+	nmi_exit();
+	set_irq_regs(old_regs);
+}
+#endif
+
 void do_interrupt(struct pt_regs *regs)
 {
 	static const unsigned int_level_mask[] = {
@@ -212,6 +237,12 @@
 		XCHAL_INTLEVEL6_MASK,
 		XCHAL_INTLEVEL7_MASK,
 	};
+	struct pt_regs *old_regs;
+
+	trace_hardirqs_off();
+
+	old_regs = set_irq_regs(regs);
+	irq_enter();
 
 	for (;;) {
 		unsigned intread = get_sr(interrupt);
@@ -227,21 +258,13 @@
 		}
 
 		if (level == 0)
-			return;
+			break;
 
-		/*
-		 * Clear the interrupt before processing, in case it's
-		 *  edge-triggered or software-generated
-		 */
-		while (int_at_level) {
-			unsigned i = __ffs(int_at_level);
-			unsigned mask = 1 << i;
-
-			int_at_level ^= mask;
-			set_sr(mask, intclear);
-			do_IRQ(i, regs);
-		}
+		do_IRQ(__ffs(int_at_level), regs);
 	}
+
+	irq_exit();
+	set_irq_regs(old_regs);
 }
 
 /*
@@ -269,7 +292,6 @@
  */
 
 #if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
-#ifndef CONFIG_XTENSA_UNALIGNED_USER
 void
 do_unaligned_user (struct pt_regs *regs)
 {
@@ -291,7 +313,6 @@
 
 }
 #endif
-#endif
 
 void
 do_debug(struct pt_regs *regs)
@@ -318,17 +339,31 @@
 }
 
 
+static void set_handler(int idx, void *handler)
+{
+	unsigned int cpu;
+
+	for_each_possible_cpu(cpu)
+		per_cpu(exc_table, cpu)[idx] = (unsigned long)handler;
+}
+
 /* Set exception C handler - for temporary use when probing exceptions */
 
 void * __init trap_set_handler(int cause, void *handler)
 {
-	unsigned long *entry = &exc_table[EXC_TABLE_DEFAULT / 4 + cause];
-	void *previous = (void *)*entry;
-	*entry = (unsigned long)handler;
+	void *previous = (void *)per_cpu(exc_table, 0)[
+		EXC_TABLE_DEFAULT / 4 + cause];
+	set_handler(EXC_TABLE_DEFAULT / 4 + cause, handler);
 	return previous;
 }
 
 
+static void trap_init_excsave(void)
+{
+	unsigned long excsave1 = (unsigned long)this_cpu_ptr(exc_table);
+	__asm__ __volatile__("wsr  %0, excsave1\n" : : "a" (excsave1));
+}
+
 /*
  * Initialize dispatch tables.
  *
@@ -342,8 +377,6 @@
  * See vectors.S for more details.
  */
 
-#define set_handler(idx,handler) (exc_table[idx] = (unsigned long) (handler))
-
 void __init trap_init(void)
 {
 	int i;
@@ -373,10 +406,15 @@
 	}
 
 	/* Initialize EXCSAVE_1 to hold the address of the exception table. */
+	trap_init_excsave();
+}
 
-	i = (unsigned long)exc_table;
-	__asm__ __volatile__("wsr  %0, excsave1\n" : : "a" (i));
+#ifdef CONFIG_SMP
+void secondary_trap_init(void)
+{
+	trap_init_excsave();
 }
+#endif
 
 /*
  * This function dumps the current valid window frame and other base registers.