1 #ifndef LINUX_HARDIRQ_H
2 #define LINUX_HARDIRQ_H
4 #include <linux/preempt.h>
5 #include <linux/smp_lock.h>
6 #include <linux/lockdep.h>
7 #include <linux/ftrace_irq.h>
8 #include <asm/hardirq.h>
9 #include <asm/system.h>
12 * We put the hardirq and softirq counter into the preemption
13 * counter. The bitmask has the following meaning:
15 * - bits 0-7 are the preemption count (max preemption depth: 256)
16 * - bits 8-15 are the softirq count (max # of softirqs: 256)
18 * The hardirq count can be overridden per architecture, the default is:
20 * - bits 16-27 are the hardirq count (max # of hardirqs: 4096)
21 * - ( bit 28 is the PREEMPT_ACTIVE flag. )
23 * PREEMPT_MASK: 0x000000ff
24 * SOFTIRQ_MASK: 0x0000ff00
25 * HARDIRQ_MASK: 0x0fff0000
27 #define PREEMPT_BITS 8
28 #define SOFTIRQ_BITS 8
31 #define HARDIRQ_BITS 12
33 #ifndef MAX_HARDIRQS_PER_CPU
34 #define MAX_HARDIRQS_PER_CPU NR_IRQS
38 * The hardirq mask has to be large enough to have space for potentially
39 * all IRQ sources in the system nesting on a single CPU.
41 #if (1 << HARDIRQ_BITS) < MAX_HARDIRQS_PER_CPU
42 # error HARDIRQ_BITS is too low!
46 #define PREEMPT_SHIFT 0
47 #define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS)
48 #define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
50 #define __IRQ_MASK(x) ((1UL << (x))-1)
52 #define PREEMPT_MASK (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
53 #define SOFTIRQ_MASK (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
54 #define HARDIRQ_MASK (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
56 #define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT)
57 #define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT)
58 #define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
60 #if PREEMPT_ACTIVE < (1 << (HARDIRQ_SHIFT + HARDIRQ_BITS))
61 #error PREEMPT_ACTIVE is too low!
64 #define hardirq_count() (preempt_count() & HARDIRQ_MASK)
65 #define softirq_count() (preempt_count() & SOFTIRQ_MASK)
66 #define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK))
69 * Are we doing bottom half or hardware interrupt processing?
70 * Are we in a softirq context? Interrupt context?
72 #define in_irq() (hardirq_count())
73 #define in_softirq() (softirq_count())
74 #define in_interrupt() (irq_count())
76 #if defined(CONFIG_PREEMPT)
77 # define PREEMPT_INATOMIC_BASE kernel_locked()
78 # define PREEMPT_CHECK_OFFSET 1
80 # define PREEMPT_INATOMIC_BASE 0
81 # define PREEMPT_CHECK_OFFSET 0
85 * Are we running in atomic context? WARNING: this macro cannot
86 * always detect atomic context; in particular, it cannot know about
87 * held spinlocks in non-preemptible kernels. Thus it should not be
88 * used in the general case to determine whether sleeping is possible.
89 * Do not use in_atomic() in driver code.
91 #define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != PREEMPT_INATOMIC_BASE)
94 * Check whether we were atomic before we did preempt_disable():
95 * (used by the scheduler, *after* releasing the kernel lock)
97 #define in_atomic_preempt_off() \
98 ((preempt_count() & ~PREEMPT_ACTIVE) != PREEMPT_CHECK_OFFSET)
100 #ifdef CONFIG_PREEMPT
101 # define preemptible() (preempt_count() == 0 && !irqs_disabled())
102 # define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1)
104 # define preemptible() 0
105 # define IRQ_EXIT_OFFSET HARDIRQ_OFFSET
109 extern void synchronize_irq(unsigned int irq
);
111 # define synchronize_irq(irq) barrier()
116 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
117 static inline void account_system_vtime(struct task_struct
*tsk
)
122 #if defined(CONFIG_NO_HZ) && !defined(CONFIG_CLASSIC_RCU)
123 extern void rcu_irq_enter(void);
124 extern void rcu_irq_exit(void);
125 extern void rcu_nmi_enter(void);
126 extern void rcu_nmi_exit(void);
128 # define rcu_irq_enter() do { } while (0)
129 # define rcu_irq_exit() do { } while (0)
130 # define rcu_nmi_enter() do { } while (0)
131 # define rcu_nmi_exit() do { } while (0)
132 #endif /* #if defined(CONFIG_NO_HZ) && !defined(CONFIG_CLASSIC_RCU) */
135 * It is safe to do non-atomic ops on ->hardirq_context,
136 * because NMI handlers may not preempt and the ops are
137 * always balanced, so the interrupted value of ->hardirq_context
138 * will always be restored.
140 #define __irq_enter() \
142 account_system_vtime(current); \
143 add_preempt_count(HARDIRQ_OFFSET); \
144 trace_hardirq_enter(); \
148 * Enter irq context (on NO_HZ, update jiffies):
150 extern void irq_enter(void);
153 * Exit irq context without processing softirqs:
155 #define __irq_exit() \
157 trace_hardirq_exit(); \
158 account_system_vtime(current); \
159 sub_preempt_count(HARDIRQ_OFFSET); \
163 * Exit irq context and process softirqs if needed:
165 extern void irq_exit(void);
167 #define nmi_enter() \
169 ftrace_nmi_enter(); \
183 #endif /* LINUX_HARDIRQ_H */
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