xref: /linux/arch/alpha/kernel/irq_srm.c (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
1 /*
2  * Handle interrupts from the SRM, assuming no additional weirdness.
3  */
4 
5 #include <linux/init.h>
6 #include <linux/sched.h>
7 #include <linux/irq.h>
8 
9 #include "proto.h"
10 #include "irq_impl.h"
11 
12 
13 /*
14  * Is the palcode SMP safe? In other words: can we call cserve_ena/dis
15  * at the same time in multiple CPUs? To be safe I added a spinlock
16  * but it can be removed trivially if the palcode is robust against smp.
17  */
18 DEFINE_SPINLOCK(srm_irq_lock);
19 
20 static inline void
21 srm_enable_irq(struct irq_data *d)
22 {
23 	spin_lock(&srm_irq_lock);
24 	cserve_ena(d->irq - 16);
25 	spin_unlock(&srm_irq_lock);
26 }
27 
28 static void
29 srm_disable_irq(struct irq_data *d)
30 {
31 	spin_lock(&srm_irq_lock);
32 	cserve_dis(d->irq - 16);
33 	spin_unlock(&srm_irq_lock);
34 }
35 
36 /* Handle interrupts from the SRM, assuming no additional weirdness.  */
37 static struct irq_chip srm_irq_type = {
38 	.name		= "SRM",
39 	.irq_unmask	= srm_enable_irq,
40 	.irq_mask	= srm_disable_irq,
41 	.irq_mask_ack	= srm_disable_irq,
42 };
43 
44 void __init
45 init_srm_irqs(long max, unsigned long ignore_mask)
46 {
47 	long i;
48 
49 	if (NR_IRQS <= 16)
50 		return;
51 	for (i = 16; i < max; ++i) {
52 		if (i < 64 && ((ignore_mask >> i) & 1))
53 			continue;
54 		irq_set_chip_and_handler(i, &srm_irq_type, handle_level_irq);
55 		irq_set_status_flags(i, IRQ_LEVEL);
56 	}
57 }
58 
59 void
60 srm_device_interrupt(unsigned long vector)
61 {
62 	int irq = (vector - 0x800) >> 4;
63 	handle_irq(irq);
64 }
65