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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef LINUX_HARDIRQ_H
2#define LINUX_HARDIRQ_H
3
4#include <linux/config.h>
Randy Dunlap67bc4eb2005-07-12 13:58:36 -07005#include <linux/preempt.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07006#include <linux/smp_lock.h>
7#include <asm/hardirq.h>
8#include <asm/system.h>
9
10/*
11 * We put the hardirq and softirq counter into the preemption
12 * counter. The bitmask has the following meaning:
13 *
14 * - bits 0-7 are the preemption count (max preemption depth: 256)
15 * - bits 8-15 are the softirq count (max # of softirqs: 256)
16 *
17 * The hardirq count can be overridden per architecture, the default is:
18 *
19 * - bits 16-27 are the hardirq count (max # of hardirqs: 4096)
20 * - ( bit 28 is the PREEMPT_ACTIVE flag. )
21 *
22 * PREEMPT_MASK: 0x000000ff
23 * SOFTIRQ_MASK: 0x0000ff00
24 * HARDIRQ_MASK: 0x0fff0000
25 */
26#define PREEMPT_BITS 8
27#define SOFTIRQ_BITS 8
28
29#ifndef HARDIRQ_BITS
30#define HARDIRQ_BITS 12
31/*
32 * The hardirq mask has to be large enough to have space for potentially
33 * all IRQ sources in the system nesting on a single CPU.
34 */
35#if (1 << HARDIRQ_BITS) < NR_IRQS
36# error HARDIRQ_BITS is too low!
37#endif
38#endif
39
40#define PREEMPT_SHIFT 0
41#define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS)
42#define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
43
44#define __IRQ_MASK(x) ((1UL << (x))-1)
45
46#define PREEMPT_MASK (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#define SOFTIRQ_MASK (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
Paolo 'Blaisorblade' Giarrusso8f28e8f2005-05-28 15:52:02 -070048#define HARDIRQ_MASK (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
50#define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT)
51#define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT)
52#define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
53
Paolo 'Blaisorblade' Giarrusso8f28e8f2005-05-28 15:52:02 -070054#if PREEMPT_ACTIVE < (1 << (HARDIRQ_SHIFT + HARDIRQ_BITS))
55#error PREEMPT_ACTIVE is too low!
56#endif
57
Linus Torvalds1da177e2005-04-16 15:20:36 -070058#define hardirq_count() (preempt_count() & HARDIRQ_MASK)
59#define softirq_count() (preempt_count() & SOFTIRQ_MASK)
60#define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK))
61
62/*
63 * Are we doing bottom half or hardware interrupt processing?
64 * Are we in a softirq context? Interrupt context?
65 */
66#define in_irq() (hardirq_count())
67#define in_softirq() (softirq_count())
68#define in_interrupt() (irq_count())
69
70#if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_BKL)
71# define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != kernel_locked())
72#else
73# define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != 0)
74#endif
75
76#ifdef CONFIG_PREEMPT
77# define preemptible() (preempt_count() == 0 && !irqs_disabled())
78# define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1)
79#else
80# define preemptible() 0
81# define IRQ_EXIT_OFFSET HARDIRQ_OFFSET
82#endif
83
84#ifdef CONFIG_SMP
85extern void synchronize_irq(unsigned int irq);
86#else
87# define synchronize_irq(irq) barrier()
88#endif
89
90#define nmi_enter() irq_enter()
91#define nmi_exit() sub_preempt_count(HARDIRQ_OFFSET)
92
93#ifndef CONFIG_VIRT_CPU_ACCOUNTING
94static inline void account_user_vtime(struct task_struct *tsk)
95{
96}
97
98static inline void account_system_vtime(struct task_struct *tsk)
99{
100}
101#endif
102
103#define irq_enter() \
104 do { \
105 account_system_vtime(current); \
106 add_preempt_count(HARDIRQ_OFFSET); \
107 } while (0)
108
109extern void irq_exit(void);
110
111#endif /* LINUX_HARDIRQ_H */