File: /usr/src/linux/include/asm-s390/hardirq.h

1     /*
2      *  include/asm-s390/hardirq.h
3      *
4      *  S390 version
5      *    Copyright (C) 1999,2000 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 */
21     typedef 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	/* CONFIG_SMP */
51     
52     #include <asm/atomic.h>
53     #include <asm/smp.h>
54     
55     extern atomic_t global_irq_holder;
56     extern atomic_t global_irq_lock;
57     extern atomic_t global_irq_count;
58     
59     static 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     
68     static inline void hardirq_enter(int cpu)
69     {
70             ++local_irq_count(cpu);
71     	atomic_inc(&global_irq_count);
72     }
73     
74     static inline void hardirq_exit(int cpu)
75     {
76     	atomic_dec(&global_irq_count);
77             --local_irq_count(cpu);
78     }
79     
80     static 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     
88     extern void synchronize_irq(void);
89     
90     #endif	/* CONFIG_SMP */
91     
92     #endif /* __ASM_HARDIRQ_H */
93