1/*
2 *  include/asm-s390/hardirq.h
3 *
4 *  S390 version
5 *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
7 *               Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
8 *
9 *  Derived from "include/asm-i386/hardirq.h"
10 */
11
12#ifndef __ASM_HARDIRQ_H
13#define __ASM_HARDIRQ_H
14
15#include <linux/config.h>
16#include <linux/threads.h>
17#include <asm/lowcore.h>
18#include <linux/sched.h>
19
20/* entry.S is sensitive to the offsets of these fields */
21typedef struct {
22	unsigned int __softirq_pending;
23	unsigned int __local_irq_count;
24	unsigned int __local_bh_count;
25	unsigned int __syscall_count;
26	struct task_struct * __ksoftirqd_task; /* waitqueue is too large */
27} ____cacheline_aligned irq_cpustat_t;
28
29#include <linux/irq_cpustat.h>	/* Standard mappings for irq_cpustat_t above */
30
31/*
32 * Are we in an interrupt context? Either doing bottom half
33 * or hardware interrupt processing?
34 */
35#define in_interrupt() ({ int __cpu = smp_processor_id(); \
36	(local_irq_count(__cpu) + local_bh_count(__cpu) != 0); })
37
38#define in_irq() (local_irq_count(smp_processor_id()) != 0)
39
40#ifndef CONFIG_SMP
41
42#define hardirq_trylock(cpu)	(local_irq_count(cpu) == 0)
43#define hardirq_endlock(cpu)	do { } while (0)
44
45#define hardirq_enter(cpu)	(local_irq_count(cpu)++)
46#define hardirq_exit(cpu)	(local_irq_count(cpu)--)
47
48#define synchronize_irq()	do { } while (0)
49
50#else
51
52#include <asm/atomic.h>
53#include <asm/smp.h>
54
55extern atomic_t global_irq_holder;
56extern atomic_t global_irq_lock;
57extern atomic_t global_irq_count;
58
59static inline void release_irqlock(int cpu)
60{
61	/* if we didn't own the irq lock, just ignore.. */
62	if (atomic_read(&global_irq_holder) ==  cpu) {
63		atomic_set(&global_irq_holder,NO_PROC_ID);
64                atomic_set(&global_irq_lock,0);
65	}
66}
67
68static inline void hardirq_enter(int cpu)
69{
70        ++local_irq_count(cpu);
71	atomic_inc(&global_irq_count);
72}
73
74static inline void hardirq_exit(int cpu)
75{
76	atomic_dec(&global_irq_count);
77        --local_irq_count(cpu);
78}
79
80static inline int hardirq_trylock(int cpu)
81{
82	return !atomic_read(&global_irq_count) &&
83               !atomic_read(&global_irq_lock);
84}
85
86#define hardirq_endlock(cpu)	do { } while (0)
87
88extern void synchronize_irq(void);
89
90#endif /* CONFIG_SMP */
91
92#endif /* __ASM_HARDIRQ_H */
93