1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright IBM Corp. 2001,2008
4  *
5  * This file contains the IRQ specific code for hvc_console
6  *
7  */
8 
9 #include <linux/interrupt.h>
10 
11 #include "hvc_console.h"
12 
hvc_handle_interrupt(int irq,void * dev_instance)13 static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance)
14 {
15 	/* if hvc_poll request a repoll, then kick the hvcd thread */
16 	if (hvc_poll(dev_instance))
17 		hvc_kick();
18 
19 	/*
20 	 * We're safe to always return IRQ_HANDLED as the hvcd thread will
21 	 * iterate through each hvc_struct.
22 	 */
23 	return IRQ_HANDLED;
24 }
25 
26 /*
27  * For IRQ based systems these callbacks can be used
28  */
notifier_add_irq(struct hvc_struct * hp,int irq)29 int notifier_add_irq(struct hvc_struct *hp, int irq)
30 {
31 	int rc;
32 
33 	if (!irq) {
34 		hp->irq_requested = 0;
35 		return 0;
36 	}
37 	rc = request_irq(irq, hvc_handle_interrupt, hp->flags,
38 			"hvc_console", hp);
39 	if (!rc)
40 		hp->irq_requested = 1;
41 	return rc;
42 }
43 
notifier_del_irq(struct hvc_struct * hp,int irq)44 void notifier_del_irq(struct hvc_struct *hp, int irq)
45 {
46 	if (!hp->irq_requested)
47 		return;
48 	free_irq(irq, hp);
49 	hp->irq_requested = 0;
50 }
51 
notifier_hangup_irq(struct hvc_struct * hp,int irq)52 void notifier_hangup_irq(struct hvc_struct *hp, int irq)
53 {
54 	notifier_del_irq(hp, irq);
55 }
56