Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq
[linux-2.6] / arch / alpha / kernel / irq_srm.c
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(unsigned int irq)
22 {
23         spin_lock(&srm_irq_lock);
24         cserve_ena(irq - 16);
25         spin_unlock(&srm_irq_lock);
26 }
27
28 static void
29 srm_disable_irq(unsigned int irq)
30 {
31         spin_lock(&srm_irq_lock);
32         cserve_dis(irq - 16);
33         spin_unlock(&srm_irq_lock);
34 }
35
36 static unsigned int
37 srm_startup_irq(unsigned int irq)
38 {
39         srm_enable_irq(irq);
40         return 0;
41 }
42
43 static void
44 srm_end_irq(unsigned int irq)
45 {
46         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
47                 srm_enable_irq(irq);
48 }
49
50 /* Handle interrupts from the SRM, assuming no additional weirdness.  */
51 static struct hw_interrupt_type srm_irq_type = {
52         .typename       = "SRM",
53         .startup        = srm_startup_irq,
54         .shutdown       = srm_disable_irq,
55         .enable         = srm_enable_irq,
56         .disable        = srm_disable_irq,
57         .ack            = srm_disable_irq,
58         .end            = srm_end_irq,
59 };
60
61 void __init
62 init_srm_irqs(long max, unsigned long ignore_mask)
63 {
64         long i;
65
66         for (i = 16; i < max; ++i) {
67                 if (i < 64 && ((ignore_mask >> i) & 1))
68                         continue;
69                 irq_desc[i].status = IRQ_DISABLED | IRQ_LEVEL;
70                 irq_desc[i].handler = &srm_irq_type;
71         }
72 }
73
74 void 
75 srm_device_interrupt(unsigned long vector, struct pt_regs * regs)
76 {
77         int irq = (vector - 0x800) >> 4;
78         handle_irq(irq, regs);
79 }