include/asm-sparc64/hardirq.h

   1 /* hardirq.h: 64-bit Sparc hard IRQ support.
   2  *
   3  * Copyright (C) 1997, 1998 David S. Miller (davem@caip.rutgers.edu)
   4  */
   5
   6 #ifndef __SPARC64_HARDIRQ_H
   7 #define __SPARC64_HARDIRQ_H
   8
   9 #include <linux/threads.h>
  10
  11 #ifndef __SMP__
  12 extern unsigned int local_irq_count;
  13 #else
  14 #define local_irq_count         (cpu_data[smp_processor_id()].irq_count)
  15 #endif
  16
  17 /*
  18  * Are we in an interrupt context? Either doing bottom half
  19  * or hardware interrupt processing?
  20  */
  21 #define in_interrupt() ((local_irq_count + local_bh_count) != 0)
  22
  23 #ifndef __SMP__
  24
  25 #define hardirq_trylock(cpu)    (local_irq_count == 0)
  26 #define hardirq_endlock(cpu)    do { } while(0)
  27
  28 #define hardirq_enter(cpu)      (local_irq_count++)
  29 #define hardirq_exit(cpu)       (local_irq_count--)
  30
  31 #define synchronize_irq()       barrier()
  32
  33 #else /* (__SMP__) */
  34
  35 #include <asm/atomic.h>
  36 #include <linux/spinlock.h>
  37 #include <asm/system.h>
  38 #include <asm/smp.h>
  39
  40 extern unsigned char global_irq_holder;
  41 extern spinlock_t global_irq_lock;
  42 extern atomic_t global_irq_count;
  43
  44 static inline void release_irqlock(int cpu)
  45 {
  46         /* if we didn't own the irq lock, just ignore... */
  47         if(global_irq_holder == (unsigned char) cpu) {
  48                 global_irq_holder = NO_PROC_ID;
  49                 spin_unlock(&global_irq_lock);
  50         }
  51 }
  52
  53 static inline void hardirq_enter(int cpu)
  54 {
  55         ++(cpu_data[cpu].irq_count);
  56         atomic_inc(&global_irq_count);
  57         membar("#StoreLoad | #StoreStore");
  58 }
  59
  60 static inline void hardirq_exit(int cpu)
  61 {
  62         membar("#StoreStore | #LoadStore");
  63         atomic_dec(&global_irq_count);
  64         --(cpu_data[cpu].irq_count);
  65 }
  66
  67 static inline int hardirq_trylock(int cpu)
  68 {
  69         return (! atomic_read(&global_irq_count) &&
  70                 ! spin_is_locked (&global_irq_lock));
  71 }
  72
  73 #define hardirq_endlock(cpu)    do { } while (0)
  74
  75 extern void synchronize_irq(void);
  76
  77 #endif /* __SMP__ */
  78
  79 #endif /* !(__SPARC64_HARDIRQ_H) */