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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>
Ingo Molnarfbb9ce952006-07-03 00:24:50 -07005#include <linux/lockdep.h>
Steven Rostedt6a60dd12008-11-06 15:55:21 -05006#include <linux/ftrace_irq.h>
Frederic Weisbeckerdcbf8322012-10-05 23:07:19 +02007#include <linux/vtime.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07008#include <asm/hardirq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07009
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 *
Steven Rostedt5a5fb7d2009-02-12 10:53:37 -050017 * The hardirq count can in theory reach the same as NR_IRQS.
18 * In reality, the number of nested IRQS is limited to the stack
19 * size as well. For archs with over 1000 IRQS it is not practical
20 * to expect that they will all nest. We give a max of 10 bits for
21 * hardirq nesting. An arch may choose to give less than 10 bits.
22 * m68k expects it to be 8.
Linus Torvalds1da177e2005-04-16 15:20:36 -070023 *
Steven Rostedt5a5fb7d2009-02-12 10:53:37 -050024 * - bits 16-25 are the hardirq count (max # of nested hardirqs: 1024)
25 * - bit 26 is the NMI_MASK
Srivatsa S. Bhata7e47862012-07-21 00:54:59 +053026 * - bit 27 is the PREEMPT_ACTIVE flag
Linus Torvalds1da177e2005-04-16 15:20:36 -070027 *
28 * PREEMPT_MASK: 0x000000ff
29 * SOFTIRQ_MASK: 0x0000ff00
Steven Rostedt5a5fb7d2009-02-12 10:53:37 -050030 * HARDIRQ_MASK: 0x03ff0000
31 * NMI_MASK: 0x04000000
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 */
33#define PREEMPT_BITS 8
34#define SOFTIRQ_BITS 8
Steven Rostedt5a5fb7d2009-02-12 10:53:37 -050035#define NMI_BITS 1
36
37#define MAX_HARDIRQ_BITS 10
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39#ifndef HARDIRQ_BITS
Steven Rostedt5a5fb7d2009-02-12 10:53:37 -050040# define HARDIRQ_BITS MAX_HARDIRQ_BITS
Eric W. Biederman23d0b8b2006-10-04 02:16:49 -070041#endif
42
Steven Rostedt5a5fb7d2009-02-12 10:53:37 -050043#if HARDIRQ_BITS > MAX_HARDIRQ_BITS
44#error HARDIRQ_BITS too high!
Linus Torvalds1da177e2005-04-16 15:20:36 -070045#endif
46
47#define PREEMPT_SHIFT 0
48#define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS)
49#define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
Steven Rostedt5a5fb7d2009-02-12 10:53:37 -050050#define NMI_SHIFT (HARDIRQ_SHIFT + HARDIRQ_BITS)
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
52#define __IRQ_MASK(x) ((1UL << (x))-1)
53
54#define PREEMPT_MASK (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
Linus Torvalds1da177e2005-04-16 15:20:36 -070055#define SOFTIRQ_MASK (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
Paolo 'Blaisorblade' Giarrusso8f28e8f2005-05-28 15:52:02 -070056#define HARDIRQ_MASK (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
Steven Rostedt5a5fb7d2009-02-12 10:53:37 -050057#define NMI_MASK (__IRQ_MASK(NMI_BITS) << NMI_SHIFT)
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
59#define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT)
60#define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT)
61#define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
Steven Rostedt5a5fb7d2009-02-12 10:53:37 -050062#define NMI_OFFSET (1UL << NMI_SHIFT)
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
Venkatesh Pallipadi75e10562010-10-04 17:03:16 -070064#define SOFTIRQ_DISABLE_OFFSET (2 * SOFTIRQ_OFFSET)
65
Arnd Bergmann8e5b59a2009-08-06 16:02:50 -070066#ifndef PREEMPT_ACTIVE
67#define PREEMPT_ACTIVE_BITS 1
68#define PREEMPT_ACTIVE_SHIFT (NMI_SHIFT + NMI_BITS)
69#define PREEMPT_ACTIVE (__IRQ_MASK(PREEMPT_ACTIVE_BITS) << PREEMPT_ACTIVE_SHIFT)
70#endif
71
Steven Rostedt5a5fb7d2009-02-12 10:53:37 -050072#if PREEMPT_ACTIVE < (1 << (NMI_SHIFT + NMI_BITS))
Paolo 'Blaisorblade' Giarrusso8f28e8f2005-05-28 15:52:02 -070073#error PREEMPT_ACTIVE is too low!
74#endif
75
Linus Torvalds1da177e2005-04-16 15:20:36 -070076#define hardirq_count() (preempt_count() & HARDIRQ_MASK)
77#define softirq_count() (preempt_count() & SOFTIRQ_MASK)
Steven Rostedt5a5fb7d2009-02-12 10:53:37 -050078#define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \
79 | NMI_MASK))
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
81/*
82 * Are we doing bottom half or hardware interrupt processing?
83 * Are we in a softirq context? Interrupt context?
Venkatesh Pallipadi75e10562010-10-04 17:03:16 -070084 * in_softirq - Are we currently processing softirq or have bh disabled?
85 * in_serving_softirq - Are we currently processing softirq?
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 */
87#define in_irq() (hardirq_count())
88#define in_softirq() (softirq_count())
89#define in_interrupt() (irq_count())
Venkatesh Pallipadi75e10562010-10-04 17:03:16 -070090#define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
Steven Rostedt375b38b2009-02-06 00:51:37 -050092/*
93 * Are we in NMI context?
94 */
Steven Rostedt5a5fb7d2009-02-12 10:53:37 -050095#define in_nmi() (preempt_count() & NMI_MASK)
Steven Rostedt375b38b2009-02-06 00:51:37 -050096
Frederic Weisbeckerbdd4e852011-06-08 01:13:27 +020097#if defined(CONFIG_PREEMPT_COUNT)
Arnd Bergmann7fe19da2010-10-28 16:12:33 +020098# define PREEMPT_CHECK_OFFSET 1
99#else
Linus Torvalds8e3e0762008-05-10 20:58:02 -0700100# define PREEMPT_CHECK_OFFSET 0
101#endif
102
Jonathan Corbet8c703d32008-03-28 14:15:49 -0700103/*
104 * Are we running in atomic context? WARNING: this macro cannot
105 * always detect atomic context; in particular, it cannot know about
106 * held spinlocks in non-preemptible kernels. Thus it should not be
107 * used in the general case to determine whether sleeping is possible.
108 * Do not use in_atomic() in driver code.
109 */
Arnd Bergmann4ba82162011-01-25 22:52:22 +0100110#define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != 0)
Ingo Molnar4da1ce62007-07-09 18:51:58 +0200111
112/*
113 * Check whether we were atomic before we did preempt_disable():
Linus Torvalds8e3e0762008-05-10 20:58:02 -0700114 * (used by the scheduler, *after* releasing the kernel lock)
Ingo Molnar4da1ce62007-07-09 18:51:58 +0200115 */
116#define in_atomic_preempt_off() \
117 ((preempt_count() & ~PREEMPT_ACTIVE) != PREEMPT_CHECK_OFFSET)
118
Frederic Weisbeckerbdd4e852011-06-08 01:13:27 +0200119#ifdef CONFIG_PREEMPT_COUNT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120# define preemptible() (preempt_count() == 0 && !irqs_disabled())
121# define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1)
122#else
123# define preemptible() 0
124# define IRQ_EXIT_OFFSET HARDIRQ_OFFSET
125#endif
126
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100127#if defined(CONFIG_SMP) || defined(CONFIG_GENERIC_HARDIRQS)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128extern void synchronize_irq(unsigned int irq);
129#else
130# define synchronize_irq(irq) barrier()
131#endif
132
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700133#if defined(CONFIG_TINY_RCU) || defined(CONFIG_TINY_PREEMPT_RCU)
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700134
135static inline void rcu_nmi_enter(void)
136{
137}
138
139static inline void rcu_nmi_exit(void)
140{
141}
142
143#else
Paul E. McKenney64db4cf2008-12-18 21:55:32 +0100144extern void rcu_nmi_enter(void);
145extern void rcu_nmi_exit(void);
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700146#endif
Steven Rostedt2232c2d2008-02-29 18:46:50 +0100147
Ingo Molnarde30a2b2006-07-03 00:24:42 -0700148/*
149 * It is safe to do non-atomic ops on ->hardirq_context,
150 * because NMI handlers may not preempt and the ops are
151 * always balanced, so the interrupted value of ->hardirq_context
152 * will always be restored.
153 */
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -0800154#define __irq_enter() \
155 do { \
Frederic Weisbeckerfa5058f2012-10-06 04:07:19 +0200156 vtime_account_irq_enter(current); \
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -0800157 add_preempt_count(HARDIRQ_OFFSET); \
158 trace_hardirq_enter(); \
159 } while (0)
160
161/*
162 * Enter irq context (on NO_HZ, update jiffies):
163 */
Ingo Molnardde4b2b2007-02-16 01:27:45 -0800164extern void irq_enter(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
Ingo Molnarde30a2b2006-07-03 00:24:42 -0700166/*
167 * Exit irq context without processing softirqs:
168 */
169#define __irq_exit() \
170 do { \
171 trace_hardirq_exit(); \
Frederic Weisbeckerfa5058f2012-10-06 04:07:19 +0200172 vtime_account_irq_exit(current); \
Ingo Molnarde30a2b2006-07-03 00:24:42 -0700173 sub_preempt_count(HARDIRQ_OFFSET); \
174 } while (0)
175
176/*
177 * Exit irq context and process softirqs if needed:
178 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179extern void irq_exit(void);
180
Steven Rostedt2a7b8df2009-02-12 14:16:46 -0500181#define nmi_enter() \
182 do { \
Steven Rostedt0f1ac8f2013-01-15 22:11:19 -0500183 lockdep_off(); \
Steven Rostedt2a7b8df2009-02-12 14:16:46 -0500184 ftrace_nmi_enter(); \
185 BUG_ON(in_nmi()); \
186 add_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \
Steven Rostedt2a7b8df2009-02-12 14:16:46 -0500187 rcu_nmi_enter(); \
188 trace_hardirq_enter(); \
Steven Rostedt17666f02008-10-30 16:08:32 -0400189 } while (0)
Linus Torvalds5f34fe12008-12-30 16:10:19 -0800190
Steven Rostedt2a7b8df2009-02-12 14:16:46 -0500191#define nmi_exit() \
192 do { \
193 trace_hardirq_exit(); \
194 rcu_nmi_exit(); \
Steven Rostedt2a7b8df2009-02-12 14:16:46 -0500195 BUG_ON(!in_nmi()); \
196 sub_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \
197 ftrace_nmi_exit(); \
Steven Rostedt0f1ac8f2013-01-15 22:11:19 -0500198 lockdep_on(); \
Steven Rostedt17666f02008-10-30 16:08:32 -0400199 } while (0)
Ingo Molnarde30a2b2006-07-03 00:24:42 -0700200
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201#endif /* LINUX_HARDIRQ_H */