Pass the previously returned IRQ back to arm_get_next_irq() so that

the implementation can guarantee forward progress in the event of
a stuck interrupt or interrupt storm. This is especially critical
for fast interrupt handlers, as they can cause a hard hang in that
case. When first called, arm_get_next_irq() is passed -1.

Obtained from:	Juniper Networks, Inc.

sys/arm/arm/intr.c

@@ -120,7 +120,8 @@ arm_handler_execute(struct trapframe *frame, int irqnb)
 	int i;
 
 	PCPU_INC(cnt.v_intr);
-	while ((i = arm_get_next_irq()) != -1) {
+	i = -1;
+	while ((i = arm_get_next_irq(i)) != -1) {
 		intrcnt[intrcnt_tab[i]]++;
 		event = intr_events[i];
 		if (intr_event_handle(event, frame) != 0) {

sys/arm/at91/at91.c

@@ -702,9 +702,8 @@ arm_mask_irq(uintptr_t nb)
 }
 
 int
-arm_get_next_irq()
+arm_get_next_irq(int last __unused)
 {
-
 	int status;
 	int irq;
 	

sys/arm/include/intr.h

@@ -56,7 +56,7 @@
 
 #include <machine/psl.h>
 
-int arm_get_next_irq(void);
+int arm_get_next_irq(int);
 void arm_mask_irq(uintptr_t);
 void arm_unmask_irq(uintptr_t);
 void arm_setup_irqhandler(const char *, int (*)(void*), void (*)(void*), 

sys/arm/mv/ic.c

@@ -137,7 +137,7 @@ static devclass_t mv_ic_devclass;
 DRIVER_MODULE(ic, mbus, mv_ic_driver, mv_ic_devclass, 0, 0);
 
 int
-arm_get_next_irq(void)
+arm_get_next_irq(int last __unused)
 {
 	int irq;
 

sys/arm/sa11x0/sa11x0_irqhandler.c

@@ -108,7 +108,7 @@ static uint32_t sa11x0_irq_mask = 0xfffffff;
 extern vm_offset_t saipic_base;
 
 int
-arm_get_next_irq()
+arm_get_next_irq(int last __unused)
 {
 	int irq;
 

sys/arm/xscale/i80321/i80321.c

@@ -240,7 +240,7 @@ i80321_iintsrc_read(void)
 }
 
 int
-arm_get_next_irq()
+arm_get_next_irq(int last __unused)
 {
 	int irq;
 

sys/arm/xscale/i8134x/i81342.c

@@ -295,7 +295,7 @@ arm_unmask_irq(uintptr_t nb)
 }
 
 int
-arm_get_next_irq(void)
+arm_get_next_irq(int last __unused)
 {
 	uint32_t val;
 	val = intpnd0_read() & intr_enabled0;

sys/arm/xscale/ixp425/ixp425.c

@@ -202,7 +202,7 @@ ixp435_irq_read(void)
 }
 
 int
-arm_get_next_irq(void)
+arm_get_next_irq(int last __unused)
 {
 	uint32_t irq;
 

sys/arm/xscale/pxa/pxa_icu.c

@@ -128,7 +128,7 @@ static devclass_t pxa_icu_devclass;
 DRIVER_MODULE(pxaicu, pxa, pxa_icu_driver, pxa_icu_devclass, 0, 0);
 
 int
-arm_get_next_irq()
+arm_get_next_irq(int last __unused)
 {
 	int	irq;