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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifdef __KERNEL__
2#ifndef _ASM_IRQ_H
3#define _ASM_IRQ_H
4
5/*
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12#include <linux/config.h>
13#include <linux/threads.h>
14
15/*
16 * Maximum number of interrupt sources that we can handle.
17 */
18#define NR_IRQS 512
19
20/* this number is used when no interrupt has been assigned */
21#define NO_IRQ (-1)
22
23/*
24 * These constants are used for passing information about interrupt
25 * signal polarity and level/edge sensing to the low-level PIC chip
26 * drivers.
27 */
28#define IRQ_SENSE_MASK 0x1
29#define IRQ_SENSE_LEVEL 0x1 /* interrupt on active level */
30#define IRQ_SENSE_EDGE 0x0 /* interrupt triggered by edge */
31
32#define IRQ_POLARITY_MASK 0x2
33#define IRQ_POLARITY_POSITIVE 0x2 /* high level or low->high edge */
34#define IRQ_POLARITY_NEGATIVE 0x0 /* low level or high->low edge */
35
36#define get_irq_desc(irq) (&irq_desc[(irq)])
37
38/* Define a way to iterate across irqs. */
39#define for_each_irq(i) \
40 for ((i) = 0; (i) < NR_IRQS; ++(i))
41
42/* Interrupt numbers are virtual in case they are sparsely
43 * distributed by the hardware.
44 */
45extern unsigned int virt_irq_to_real_map[NR_IRQS];
46
47/* Create a mapping for a real_irq if it doesn't already exist.
48 * Return the virtual irq as a convenience.
49 */
50int virt_irq_create_mapping(unsigned int real_irq);
51void virt_irq_init(void);
52
53static inline unsigned int virt_irq_to_real(unsigned int virt_irq)
54{
55 return virt_irq_to_real_map[virt_irq];
56}
57
58extern unsigned int real_irq_to_virt_slowpath(unsigned int real_irq);
59
60/*
61 * Because many systems have two overlapping names spaces for
62 * interrupts (ISA and XICS for example), and the ISA interrupts
63 * have historically not been easy to renumber, we allow ISA
64 * interrupts to take values 0 - 15, and shift up the remaining
65 * interrupts by 0x10.
66 */
67#define NUM_ISA_INTERRUPTS 0x10
68extern int __irq_offset_value;
69
70static inline int irq_offset_up(int irq)
71{
72 return(irq + __irq_offset_value);
73}
74
75static inline int irq_offset_down(int irq)
76{
77 return(irq - __irq_offset_value);
78}
79
80static inline int irq_offset_value(void)
81{
82 return __irq_offset_value;
83}
84
85static __inline__ int irq_canonicalize(int irq)
86{
87 return irq;
88}
89
90extern int distribute_irqs;
91
92struct irqaction;
93struct pt_regs;
94
95#ifdef CONFIG_IRQSTACKS
96/*
97 * Per-cpu stacks for handling hard and soft interrupts.
98 */
99extern struct thread_info *hardirq_ctx[NR_CPUS];
100extern struct thread_info *softirq_ctx[NR_CPUS];
101
102extern void irq_ctx_init(void);
103extern void call_do_softirq(struct thread_info *tp);
104extern int call_handle_IRQ_event(int irq, struct pt_regs *regs,
105 struct irqaction *action, struct thread_info *tp);
106
107#define __ARCH_HAS_DO_SOFTIRQ
108
109#else
110#define irq_ctx_init()
111
112#endif /* CONFIG_IRQSTACKS */
113
114#endif /* _ASM_IRQ_H */
115#endif /* __KERNEL__ */