[S390] irq: external interrupt code passing

The external interrupt handlers have a parameter called ext_int_code.
Besides the name this paramter does not only contain the ext_int_code
but in addition also the "cpu address" (POP) which caused the external
interrupt.
To make the code a bit more obvious pass a struct instead so the called
function can easily distinguish between external interrupt code and
cpu address. The cpu address field however is named "subcode" since
some external interrupt sources do not pass a cpu address but a
different parameter (or none at all).

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/entry.h

@@ -35,7 +35,8 @@ int handle_signal32(unsigned long sig, struct k_sigaction *ka,
 		    siginfo_t *info, sigset_t *oldset, struct pt_regs *regs);
 void do_notify_resume(struct pt_regs *regs);
 
-void do_extint(struct pt_regs *regs, unsigned int, unsigned int, unsigned long);
+struct ext_code;
+void do_extint(struct pt_regs *regs, struct ext_code, unsigned int, unsigned long);
 void do_restart(void);
 void __init startup_init(void);
 void die(struct pt_regs *regs, const char *str);

arch/s390/kernel/irq.c

@@ -209,29 +209,27 @@ int unregister_external_interrupt(u16 code, ext_int_handler_t handler)
 }
 EXPORT_SYMBOL(unregister_external_interrupt);
 
-void __irq_entry do_extint(struct pt_regs *regs, unsigned int ext_int_code,
+void __irq_entry do_extint(struct pt_regs *regs, struct ext_code ext_code,
 			   unsigned int param32, unsigned long param64)
 {
 	struct pt_regs *old_regs;
-	unsigned short code;
 	struct ext_int_info *p;
 	int index;
 
-	code = (unsigned short) ext_int_code;
 	old_regs = set_irq_regs(regs);
 	irq_enter();
 	if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
 		/* Serve timer interrupts first. */
 		clock_comparator_work();
 	kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
-	if (code != 0x1004)
+	if (ext_code.code != 0x1004)
 		__get_cpu_var(s390_idle).nohz_delay = 1;
 
-	index = ext_hash(code);
+	index = ext_hash(ext_code.code);
 	rcu_read_lock();
 	list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
-		if (likely(p->code == code))
-			p->handler(ext_int_code, param32, param64);
+		if (likely(p->code == ext_code.code))
+			p->handler(ext_code, param32, param64);
 	rcu_read_unlock();
 	irq_exit();
 	set_irq_regs(old_regs);

arch/s390/kernel/smp.c

@@ -434,14 +434,14 @@ void smp_stop_cpu(void)
  * This is the main routine where commands issued by other
  * cpus are handled.
  */
-static void do_ext_call_interrupt(unsigned int ext_int_code,
+static void do_ext_call_interrupt(struct ext_code ext_code,
 				  unsigned int param32, unsigned long param64)
 {
 	unsigned long bits;
 	int cpu;
 
 	cpu = smp_processor_id();
-	if ((ext_int_code & 0xffff) == 0x1202)
+	if (ext_code.code == 0x1202)
 		kstat_cpu(cpu).irqs[EXTINT_EXC]++;
 	else
 		kstat_cpu(cpu).irqs[EXTINT_EMS]++;

arch/s390/kernel/time.c

@@ -165,7 +165,7 @@ void init_cpu_timer(void)
 	__ctl_set_bit(0, 4);
 }
 
-static void clock_comparator_interrupt(unsigned int ext_int_code,
+static void clock_comparator_interrupt(struct ext_code ext_code,
 				       unsigned int param32,
 				       unsigned long param64)
 {
@@ -177,7 +177,7 @@ static void clock_comparator_interrupt(unsigned int ext_int_code,
 static void etr_timing_alert(struct etr_irq_parm *);
 static void stp_timing_alert(struct stp_irq_parm *);
 
-static void timing_alert_interrupt(unsigned int ext_int_code,
+static void timing_alert_interrupt(struct ext_code ext_code,
 				   unsigned int param32, unsigned long param64)
 {
 	kstat_cpu(smp_processor_id()).irqs[EXTINT_TLA]++;

arch/s390/kernel/vtime.c

@@ -220,7 +220,7 @@ static void do_callbacks(struct list_head *cb_list)
 /*
  * Handler for the virtual CPU timer.
  */
-static void do_cpu_timer_interrupt(unsigned int ext_int_code,
+static void do_cpu_timer_interrupt(struct ext_code ext_code,
 				   unsigned int param32, unsigned long param64)
 {
 	struct vtimer_queue *vq;