blob: 612472aaa79c1607159794a2257356bde263e9a0 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef LINUX_HARDIRQ_H
2#define LINUX_HARDIRQ_H
3
Randy Dunlap67bc4eb2005-07-12 13:58:36 -07004#include <linux/preempt.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07005#include <linux/smp_lock.h>
Ingo Molnarfbb9ce952006-07-03 00:24:50 -07006#include <linux/lockdep.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007#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
Eric W. Biederman23d0b8b2006-10-04 02:16:49 -070031
32#ifndef MAX_HARDIRQS_PER_CPU
33#define MAX_HARDIRQS_PER_CPU NR_IRQS
34#endif
35
Linus Torvalds1da177e2005-04-16 15:20:36 -070036/*
37 * The hardirq mask has to be large enough to have space for potentially
38 * all IRQ sources in the system nesting on a single CPU.
39 */
Eric W. Biederman23d0b8b2006-10-04 02:16:49 -070040#if (1 << HARDIRQ_BITS) < MAX_HARDIRQS_PER_CPU
Linus Torvalds1da177e2005-04-16 15:20:36 -070041# error HARDIRQ_BITS is too low!
42#endif
43#endif
44
45#define PREEMPT_SHIFT 0
46#define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS)
47#define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
48
49#define __IRQ_MASK(x) ((1UL << (x))-1)
50
51#define PREEMPT_MASK (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
Linus Torvalds1da177e2005-04-16 15:20:36 -070052#define SOFTIRQ_MASK (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
Paolo 'Blaisorblade' Giarrusso8f28e8f2005-05-28 15:52:02 -070053#define HARDIRQ_MASK (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
55#define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT)
56#define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT)
57#define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
58
Paolo 'Blaisorblade' Giarrusso8f28e8f2005-05-28 15:52:02 -070059#if PREEMPT_ACTIVE < (1 << (HARDIRQ_SHIFT + HARDIRQ_BITS))
60#error PREEMPT_ACTIVE is too low!
61#endif
62
Linus Torvalds1da177e2005-04-16 15:20:36 -070063#define hardirq_count() (preempt_count() & HARDIRQ_MASK)
64#define softirq_count() (preempt_count() & SOFTIRQ_MASK)
65#define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK))
66
67/*
68 * Are we doing bottom half or hardware interrupt processing?
69 * Are we in a softirq context? Interrupt context?
70 */
71#define in_irq() (hardirq_count())
72#define in_softirq() (softirq_count())
73#define in_interrupt() (irq_count())
74
75#if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_BKL)
76# define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != kernel_locked())
77#else
78# define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != 0)
79#endif
80
81#ifdef CONFIG_PREEMPT
82# define preemptible() (preempt_count() == 0 && !irqs_disabled())
83# define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1)
84#else
85# define preemptible() 0
86# define IRQ_EXIT_OFFSET HARDIRQ_OFFSET
87#endif
88
89#ifdef CONFIG_SMP
90extern void synchronize_irq(unsigned int irq);
91#else
92# define synchronize_irq(irq) barrier()
93#endif
94
Al Virof0373602005-11-13 16:06:57 -080095struct task_struct;
96
Linus Torvalds1da177e2005-04-16 15:20:36 -070097#ifndef CONFIG_VIRT_CPU_ACCOUNTING
Linus Torvalds1da177e2005-04-16 15:20:36 -070098static inline void account_system_vtime(struct task_struct *tsk)
99{
100}
101#endif
102
Ingo Molnarde30a2b2006-07-03 00:24:42 -0700103/*
104 * It is safe to do non-atomic ops on ->hardirq_context,
105 * because NMI handlers may not preempt and the ops are
106 * always balanced, so the interrupted value of ->hardirq_context
107 * will always be restored.
108 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109#define irq_enter() \
110 do { \
111 account_system_vtime(current); \
112 add_preempt_count(HARDIRQ_OFFSET); \
Ingo Molnarde30a2b2006-07-03 00:24:42 -0700113 trace_hardirq_enter(); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 } while (0)
115
Ingo Molnarde30a2b2006-07-03 00:24:42 -0700116/*
117 * Exit irq context without processing softirqs:
118 */
119#define __irq_exit() \
120 do { \
121 trace_hardirq_exit(); \
122 account_system_vtime(current); \
123 sub_preempt_count(HARDIRQ_OFFSET); \
124 } while (0)
125
126/*
127 * Exit irq context and process softirqs if needed:
128 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129extern void irq_exit(void);
130
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700131#define nmi_enter() do { lockdep_off(); irq_enter(); } while (0)
132#define nmi_exit() do { __irq_exit(); lockdep_on(); } while (0)
Ingo Molnarde30a2b2006-07-03 00:24:42 -0700133
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134#endif /* LINUX_HARDIRQ_H */