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.
12 #include <linux/config.h>
13 #include <linux/threads.h>
16 * Maximum number of interrupt sources that we can handle.
20 /* this number is used when no interrupt has been assigned */
24 * These constants are used for passing information about interrupt
25 * signal polarity and level/edge sensing to the low-level PIC chip
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 */
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 */
36 #define get_irq_desc(irq) (&irq_desc[(irq)])
38 /* Define a way to iterate across irqs. */
39 #define for_each_irq(i) \
40 for ((i) = 0; (i) < NR_IRQS; ++(i))
42 /* Interrupt numbers are virtual in case they are sparsely
43 * distributed by the hardware.
45 extern unsigned int virt_irq_to_real_map[NR_IRQS];
47 /* Create a mapping for a real_irq if it doesn't already exist.
48 * Return the virtual irq as a convenience.
50 int virt_irq_create_mapping(unsigned int real_irq);
51 void virt_irq_init(void);
53 static inline unsigned int virt_irq_to_real(unsigned int virt_irq)
55 return virt_irq_to_real_map[virt_irq];
58 extern unsigned int real_irq_to_virt_slowpath(unsigned int real_irq);
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
67 #define NUM_ISA_INTERRUPTS 0x10
68 extern int __irq_offset_value;
70 static inline int irq_offset_up(int irq)
72 return(irq + __irq_offset_value);
75 static inline int irq_offset_down(int irq)
77 return(irq - __irq_offset_value);
80 static inline int irq_offset_value(void)
82 return __irq_offset_value;
85 static __inline__ int irq_canonicalize(int irq)
90 extern int distribute_irqs;
95 #ifdef CONFIG_IRQSTACKS
97 * Per-cpu stacks for handling hard and soft interrupts.
99 extern struct thread_info *hardirq_ctx[NR_CPUS];
100 extern struct thread_info *softirq_ctx[NR_CPUS];
102 extern void irq_ctx_init(void);
103 extern void call_do_softirq(struct thread_info *tp);
104 extern int call_handle_IRQ_event(int irq, struct pt_regs *regs,
105 struct irqaction *action, struct thread_info *tp);
107 #define __ARCH_HAS_DO_SOFTIRQ
110 #define irq_ctx_init()
112 #endif /* CONFIG_IRQSTACKS */
114 #endif /* _ASM_IRQ_H */
115 #endif /* __KERNEL__ */