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 <asm/hardirq.h>
8 #include <asm/system.h>
11 * We put the hardirq and softirq counter into the preemption
12 * counter. The bitmask has the following meaning:
14 * - bits 0-7 are the preemption count (max preemption depth: 256)
15 * - bits 8-15 are the softirq count (max # of softirqs: 256)
17 * The hardirq count can be overridden per architecture, the default is:
19 * - bits 16-27 are the hardirq count (max # of hardirqs: 4096)
20 * - ( bit 28 is the PREEMPT_ACTIVE flag. )
22 * PREEMPT_MASK: 0x000000ff
23 * SOFTIRQ_MASK: 0x0000ff00
24 * HARDIRQ_MASK: 0x0fff0000
26 #define PREEMPT_BITS 8
27 #define SOFTIRQ_BITS 8
30 #define HARDIRQ_BITS 12
32 #ifndef MAX_HARDIRQS_PER_CPU
33 #define MAX_HARDIRQS_PER_CPU NR_IRQS
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.
40 #if (1 << HARDIRQ_BITS) < MAX_HARDIRQS_PER_CPU
41 # error HARDIRQ_BITS is too low!
45 #define PREEMPT_SHIFT 0
46 #define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS)
47 #define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
49 #define __IRQ_MASK(x) ((1UL << (x))-1)
51 #define PREEMPT_MASK (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
52 #define SOFTIRQ_MASK (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
53 #define HARDIRQ_MASK (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
55 #define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT)
56 #define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT)
57 #define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
59 #if PREEMPT_ACTIVE < (1 << (HARDIRQ_SHIFT + HARDIRQ_BITS))
60 #error PREEMPT_ACTIVE is too low!
63 #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))
68 * Are we doing bottom half or hardware interrupt processing?
69 * Are we in a softirq context? Interrupt context?
71 #define in_irq() (hardirq_count())
72 #define in_softirq() (softirq_count())
73 #define in_interrupt() (irq_count())
75 #if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_BKL)
76 # define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != kernel_locked())
78 # define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != 0)
82 # define preemptible() (preempt_count() == 0 && !irqs_disabled())
83 # define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1)
85 # define preemptible() 0
86 # define IRQ_EXIT_OFFSET HARDIRQ_OFFSET
90 extern void synchronize_irq(unsigned int irq
);
92 # define synchronize_irq(irq) barrier()
97 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
98 static inline void account_system_vtime(struct task_struct
*tsk
)
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.
109 #define irq_enter() \
111 account_system_vtime(current); \
112 add_preempt_count(HARDIRQ_OFFSET); \
113 trace_hardirq_enter(); \
117 * Exit irq context without processing softirqs:
119 #define __irq_exit() \
121 trace_hardirq_exit(); \
122 account_system_vtime(current); \
123 sub_preempt_count(HARDIRQ_OFFSET); \
127 * Exit irq context and process softirqs if needed:
129 extern void irq_exit(void);
131 #define nmi_enter() do { lockdep_off(); irq_enter(); } while (0)
132 #define nmi_exit() do { __irq_exit(); lockdep_on(); } while (0)
134 #endif /* LINUX_HARDIRQ_H */