include/asm-sparc/hardirq.h

   1 /* hardirq.h: 32-bit Sparc hard IRQ support.
   2  *
   3  * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
   4  * Copyright (C) 1998-99 Anton Blanchard (anton@progsoc.uts.edu.au)
   5  */
   6
   7 #ifndef __SPARC_HARDIRQ_H
   8 #define __SPARC_HARDIRQ_H
   9
  10 #include <linux/threads.h>
  11
  12 #ifndef __SMP__
  13 extern unsigned int local_irq_count;
  14
  15 /*
  16  * Are we in an interrupt context? Either doing bottom half
  17  * or hardware interrupt processing?
  18  */
  19 #define in_interrupt()  ((local_irq_count + local_bh_count) != 0)
  20
  21 #define hardirq_trylock(cpu)    (local_irq_count == 0)
  22 #define hardirq_endlock(cpu)    do { } while (0)
  23
  24 #define hardirq_enter(cpu)      (local_irq_count++)
  25 #define hardirq_exit(cpu)       (local_irq_count--)
  26
  27 #define synchronize_irq()       barrier()
  28
  29 #else
  30
  31 #include <asm/atomic.h>
  32 #include <linux/spinlock.h>
  33 #include <asm/system.h>
  34 #include <asm/smp.h>
  35
  36 extern unsigned int local_irq_count[NR_CPUS];
  37 extern unsigned char global_irq_holder;
  38 extern spinlock_t global_irq_lock;
  39 extern atomic_t global_irq_count;
  40
  41 /*
  42  * Are we in an interrupt context? Either doing bottom half
  43  * or hardware interrupt processing?
  44  */
  45 #define in_interrupt() ({ int __cpu = smp_processor_id(); \
  46         (local_irq_count[__cpu] + local_bh_count[__cpu] != 0); })
  47
  48 static inline void release_irqlock(int cpu)
  49 {
  50         /* if we didn't own the irq lock, just ignore.. */
  51         if (global_irq_holder == (unsigned char) cpu) {
  52                 global_irq_holder = NO_PROC_ID;
  53                 spin_unlock(&global_irq_lock);
  54         }
  55 }
  56
  57 static inline void hardirq_enter(int cpu)
  58 {
  59         ++local_irq_count[cpu];
  60         atomic_inc(&global_irq_count);
  61 }
  62
  63 static inline void hardirq_exit(int cpu)
  64 {
  65         atomic_dec(&global_irq_count);
  66         --local_irq_count[cpu];
  67 }
  68
  69 static inline int hardirq_trylock(int cpu)
  70 {
  71         return (! atomic_read(&global_irq_count) &&
  72                 ! spin_is_locked (&global_irq_lock));
  73 }
  74
  75 #define hardirq_endlock(cpu)    do { } while (0)
  76
  77 extern void synchronize_irq(void);
  78
  79 #endif /* __SMP__ */
  80
  81 #endif /* __SPARC_HARDIRQ_H */