blob: ebc712e910669ea863b65c684560e1f0d756244f [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef LINUX_HARDIRQ_H
2#define LINUX_HARDIRQ_H
3
4#include <linux/config.h>
5#include <linux/smp_lock.h>
6#include <asm/hardirq.h>
7#include <asm/system.h>
8
9/*
10 * We put the hardirq and softirq counter into the preemption
11 * counter. The bitmask has the following meaning:
12 *
13 * - bits 0-7 are the preemption count (max preemption depth: 256)
14 * - bits 8-15 are the softirq count (max # of softirqs: 256)
15 *
16 * The hardirq count can be overridden per architecture, the default is:
17 *
18 * - bits 16-27 are the hardirq count (max # of hardirqs: 4096)
19 * - ( bit 28 is the PREEMPT_ACTIVE flag. )
20 *
21 * PREEMPT_MASK: 0x000000ff
22 * SOFTIRQ_MASK: 0x0000ff00
23 * HARDIRQ_MASK: 0x0fff0000
24 */
25#define PREEMPT_BITS 8
26#define SOFTIRQ_BITS 8
27
28#ifndef HARDIRQ_BITS
29#define HARDIRQ_BITS 12
30/*
31 * The hardirq mask has to be large enough to have space for potentially
32 * all IRQ sources in the system nesting on a single CPU.
33 */
34#if (1 << HARDIRQ_BITS) < NR_IRQS
35# error HARDIRQ_BITS is too low!
36#endif
37#endif
38
39#define PREEMPT_SHIFT 0
40#define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS)
41#define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
42
43#define __IRQ_MASK(x) ((1UL << (x))-1)
44
45#define PREEMPT_MASK (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
46#define HARDIRQ_MASK (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
47#define SOFTIRQ_MASK (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
48
49#define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT)
50#define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT)
51#define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
52
53#define hardirq_count() (preempt_count() & HARDIRQ_MASK)
54#define softirq_count() (preempt_count() & SOFTIRQ_MASK)
55#define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK))
56
57/*
58 * Are we doing bottom half or hardware interrupt processing?
59 * Are we in a softirq context? Interrupt context?
60 */
61#define in_irq() (hardirq_count())
62#define in_softirq() (softirq_count())
63#define in_interrupt() (irq_count())
64
65#if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_BKL)
66# define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != kernel_locked())
67#else
68# define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != 0)
69#endif
70
71#ifdef CONFIG_PREEMPT
72# define preemptible() (preempt_count() == 0 && !irqs_disabled())
73# define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1)
74#else
75# define preemptible() 0
76# define IRQ_EXIT_OFFSET HARDIRQ_OFFSET
77#endif
78
79#ifdef CONFIG_SMP
80extern void synchronize_irq(unsigned int irq);
81#else
82# define synchronize_irq(irq) barrier()
83#endif
84
85#define nmi_enter() irq_enter()
86#define nmi_exit() sub_preempt_count(HARDIRQ_OFFSET)
87
88#ifndef CONFIG_VIRT_CPU_ACCOUNTING
89static inline void account_user_vtime(struct task_struct *tsk)
90{
91}
92
93static inline void account_system_vtime(struct task_struct *tsk)
94{
95}
96#endif
97
98#define irq_enter() \
99 do { \
100 account_system_vtime(current); \
101 add_preempt_count(HARDIRQ_OFFSET); \
102 } while (0)
103
104extern void irq_exit(void);
105
106#endif /* LINUX_HARDIRQ_H */