[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 <[e-mail]>
Signed-off-by: Martin Schwidefsky <[e-mail]>

arch/s390/include/asm/irq.h

···
 	NR_IRQS,
 };
 
-typedef void (*ext_int_handler_t)(unsigned int, unsigned int, unsigned long);
+struct ext_code {
+	unsigned short subcode;
+	unsigned short code;
+};
+
+typedef void (*ext_int_handler_t)(struct ext_code, unsigned int, unsigned long);
 
 int register_external_interrupt(u16 code, ext_int_handler_t handler);
 int unregister_external_interrupt(u16 code, ext_int_handler_t handler);

arch/s390/kernel/entry.h

···
 		    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

···
 }
 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

···
  * 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

···
 	__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)
 {
···
 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

···
 /*
  * 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;

arch/s390/mm/fault.c

···
 static DEFINE_SPINLOCK(pfault_lock);
 static LIST_HEAD(pfault_list);
 
-static void pfault_interrupt(unsigned int ext_int_code,
+static void pfault_interrupt(struct ext_code ext_code,
 			     unsigned int param32, unsigned long param64)
 {
 	struct task_struct *tsk;
···
 	 * in the 'cpu address' field associated with the
          * external interrupt. 
 	 */
-	subcode = ext_int_code >> 16;
+	subcode = ext_code.subcode;
 	if ((subcode & 0xff00) != __SUBCODE_MASK)
 		return;
 	kstat_cpu(smp_processor_id()).irqs[EXTINT_PFL]++;

arch/s390/oprofile/hwsampler.c

···
 }
 
 /* prototypes for external interrupt handler and worker */
-static void hws_ext_handler(unsigned int ext_int_code,
-				unsigned int param32, unsigned long param64);
+static void hws_ext_handler(struct ext_code ext_code,
+			    unsigned int param32, unsigned long param64);
 
 static void worker(struct work_struct *work);
 
···
 	return rc;
 }
 
-static void hws_ext_handler(unsigned int ext_int_code,
+static void hws_ext_handler(struct ext_code ext_code,
 			    unsigned int param32, unsigned long param64)
 {
 	struct hws_cpu_buffer *cb;

drivers/s390/block/dasd_diag.c

···
 }
 
 /* Handle external interruption. */
-static void dasd_ext_handler(unsigned int ext_int_code,
+static void dasd_ext_handler(struct ext_code ext_code,
 			     unsigned int param32, unsigned long param64)
 {
 	struct dasd_ccw_req *cqr, *next;
···
 	addr_t ip;
 	int rc;
 
-	switch (ext_int_code >> 24) {
+	switch (ext_code.subcode >> 8) {
 	case DASD_DIAG_CODE_31BIT:
 		ip = (addr_t) param32;
 		break;
···
 	cqr->stopclk = get_clock();
 
 	expires = 0;
-	if ((ext_int_code & 0xff0000) == 0) {
+	if ((ext_code.subcode & 0xff) == 0) {
 		cqr->status = DASD_CQR_SUCCESS;
 		/* Start first request on queue if possible -> fast_io. */
 		if (!list_empty(&device->ccw_queue)) {
···
 		cqr->status = DASD_CQR_QUEUED;
 		DBF_DEV_EVENT(DBF_DEBUG, device, "interrupt status for "
 			      "request %p was %d (%d retries left)", cqr,
-			      (ext_int_code >> 16) & 0xff, cqr->retries);
+			      ext_code.subcode & 0xff, cqr->retries);
 		dasd_diag_erp(device);
 	}
 

drivers/s390/char/sclp.c

···
 /* Handler for external interruption. Perform request post-processing.
  * Prepare read event data request if necessary. Start processing of next
  * request on queue. */
-static void sclp_interrupt_handler(unsigned int ext_int_code,
+static void sclp_interrupt_handler(struct ext_code ext_code,
 				   unsigned int param32, unsigned long param64)
 {
 	struct sclp_req *req;
···
 
 /* Handler for external interruption used during initialization. Modify
  * request state to done. */
-static void sclp_check_handler(unsigned int ext_int_code,
+static void sclp_check_handler(struct ext_code ext_code,
 			       unsigned int param32, unsigned long param64)
 {
 	u32 finished_sccb;

drivers/s390/kvm/kvm_virtio.c

···
 /*
  * we emulate the request_irq behaviour on top of s390 extints
  */
-static void kvm_extint_handler(unsigned int ext_int_code,
+static void kvm_extint_handler(struct ext_code ext_code,
 			       unsigned int param32, unsigned long param64)
 {
 	struct virtqueue *vq;
-	u16 subcode;
 	u32 param;
 
-	subcode = ext_int_code >> 16;
-	if ((subcode & 0xff00) != VIRTIO_SUBCODE_64)
+	if ((ext_code.subcode & 0xff00) != VIRTIO_SUBCODE_64)
 		return;
 	kstat_cpu(smp_processor_id()).irqs[EXTINT_VRT]++;
 

net/iucv/iucv.c

···
  * Handles external interrupts coming in from CP.
  * Places the interrupt buffer on a queue and schedules iucv_tasklet_fn().
  */
-static void iucv_external_interrupt(unsigned int ext_int_code,
+static void iucv_external_interrupt(struct ext_code ext_code,
 				    unsigned int param32, unsigned long param64)
 {
 	struct iucv_irq_data *p;