1 #ifndef LINUX_HARDIRQ_H
2 #define LINUX_HARDIRQ_H
4 #include <linux/config.h>
5 #include <linux/smp_lock.h>
6 #include <asm/hardirq.h>
9 * We put the hardirq and softirq counter into the preemption
10 * counter. The bitmask has the following meaning:
12 * - bits 0-7 are the preemption count (max preemption depth: 256)
13 * - bits 8-15 are the softirq count (max # of softirqs: 256)
15 * The hardirq count can be overridden per architecture, the default is:
17 * - bits 16-27 are the hardirq count (max # of hardirqs: 4096)
18 * - ( bit 28 is the PREEMPT_ACTIVE flag. )
20 * PREEMPT_MASK: 0x000000ff
21 * SOFTIRQ_MASK: 0x0000ff00
22 * HARDIRQ_MASK: 0x0fff0000
24 #define PREEMPT_BITS 8
25 #define SOFTIRQ_BITS 8
28 #define HARDIRQ_BITS 12
30 * The hardirq mask has to be large enough to have space for potentially
31 * all IRQ sources in the system nesting on a single CPU.
33 #if (1 << HARDIRQ_BITS) < NR_IRQS
34 # error HARDIRQ_BITS is too low!
38 #define PREEMPT_SHIFT 0
39 #define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS)
40 #define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
42 #define __IRQ_MASK(x) ((1UL << (x))-1)
44 #define PREEMPT_MASK (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
45 #define HARDIRQ_MASK (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
46 #define SOFTIRQ_MASK (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
48 #define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT)
49 #define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT)
50 #define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
52 #define hardirq_count() (preempt_count() & HARDIRQ_MASK)
53 #define softirq_count() (preempt_count() & SOFTIRQ_MASK)
54 #define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK))
57 * Are we doing bottom half or hardware interrupt processing?
58 * Are we in a softirq context? Interrupt context?
60 #define in_irq() (hardirq_count())
61 #define in_softirq() (softirq_count())
62 #define in_interrupt() (irq_count())
65 # define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != kernel_locked())
66 # define preemptible() (preempt_count() == 0 && !irqs_disabled())
67 # define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1)
69 # define in_atomic() (preempt_count() != 0)
70 # define preemptible() 0
71 # define IRQ_EXIT_OFFSET HARDIRQ_OFFSET
75 extern void synchronize_irq(unsigned int irq);
77 # define synchronize_irq(irq) barrier()
80 #ifdef CONFIG_GENERIC_HARDIRQS
81 #define nmi_enter() (preempt_count() += HARDIRQ_OFFSET)
82 #define nmi_exit() (preempt_count() -= HARDIRQ_OFFSET)
84 #define irq_enter() (preempt_count() += HARDIRQ_OFFSET)
85 extern void irq_exit(void);
88 #endif /* LINUX_HARDIRQ_H */