1 /* hardirq.h: 32-bit Sparc hard IRQ support.
2 *
3 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
4 * Copyright (C) 1998-2000 Anton Blanchard (anton@linuxcare.com)
5 */
6
7 #ifndef __SPARC_HARDIRQ_H
8 #define __SPARC_HARDIRQ_H
9
10 #include <linux/config.h>
11 #include <linux/threads.h>
12 #include <linux/brlock.h>
13 #include <linux/spinlock.h>
14
15 /* entry.S is sensitive to the offsets of these fields */
16 typedef struct {
17 unsigned int __softirq_active;
18 unsigned int __softirq_mask;
19 #ifndef CONFIG_SMP
20 unsigned int __local_irq_count;
21 #else
22 unsigned int __unused_on_SMP; /* DaveM says use brlock for SMP irq. KAO */
23 #endif
24 unsigned int __local_bh_count;
25 unsigned int __syscall_count;
26 } ____cacheline_aligned irq_cpustat_t;
27
28 #include <linux/irq_cpustat.h> /* Standard mappings for irq_cpustat_t above */
29 /* Note that local_irq_count() is replaced by sparc64 specific version for SMP */
30
31 #ifndef CONFIG_SMP
32 #define irq_enter(cpu, irq) ((void)(irq), local_irq_count(cpu)++)
33 #define irq_exit(cpu, irq) ((void)(irq), local_irq_count(cpu)--)
34 #else
35 #undef local_irq_count
36 #define local_irq_count(cpu) (__brlock_array[cpu][BR_GLOBALIRQ_LOCK])
37 #define irq_enter(cpu, irq) br_read_lock(BR_GLOBALIRQ_LOCK)
38 #define irq_exit(cpu, irq) br_read_unlock(BR_GLOBALIRQ_LOCK)
39 #endif
40
41 /*
42 * Are we in an interrupt context? Either doing bottom half
43 * or hardware interrupt processing?
44 */
45 #define in_interrupt() ((local_irq_count(smp_processor_id()) + \
46 local_bh_count(smp_processor_id())) != 0)
47
48 /* This tests only the local processors hw IRQ context disposition. */
49 #define in_irq() (local_irq_count(smp_processor_id()) != 0)
50
51 #ifndef CONFIG_SMP
52
53 #define hardirq_trylock(cpu) ((void)(cpu), local_irq_count(smp_processor_id()) == 0)
54 #define hardirq_endlock(cpu) do { (void)(cpu); } while(0)
55
56 #define synchronize_irq() barrier()
57
58 #else /* (CONFIG_SMP) */
59
60 static __inline__ int irqs_running(void)
61 {
62 int i;
63
64 for (i = 0; i < smp_num_cpus; i++)
65 if (local_irq_count(cpu_logical_map(i)))
66 return 1;
67 return 0;
68 }
69
70 extern unsigned char global_irq_holder;
71
72 static inline void release_irqlock(int cpu)
73 {
74 /* if we didn't own the irq lock, just ignore... */
75 if(global_irq_holder == (unsigned char) cpu) {
76 global_irq_holder = NO_PROC_ID;
77 br_write_unlock(BR_GLOBALIRQ_LOCK);
78 }
79 }
80
81 static inline int hardirq_trylock(int cpu)
82 {
83 spinlock_t *lock = &__br_write_locks[BR_GLOBALIRQ_LOCK].lock;
84
85 return (!local_irq_count(cpu) && !spin_is_locked(lock));
86 }
87
88 #define hardirq_endlock(cpu) do { (void)(cpu); } while (0)
89
90 extern void synchronize_irq(void);
91
92 #endif /* CONFIG_SMP */
93
94 #endif /* __SPARC_HARDIRQ_H */
95
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