include/asm-alpha/hardirq.h

   1 #ifndef _ALPHA_HARDIRQ_H
   2 #define _ALPHA_HARDIRQ_H
   3
   4 /* Initially just a straight copy of the i386 code.  */
   5
   6 #include <linux/threads.h>
   7
   8 #ifndef __SMP__
   9 extern int __local_irq_count;
  10 #define local_irq_count(cpu)  ((void)(cpu), __local_irq_count)
  11 #else
  12 #define local_irq_count(cpu)  (cpu_data[cpu].irq_count)
  13 #endif
  14
  15 /*
  16  * Are we in an interrupt context? Either doing bottom half
  17  * or hardware interrupt processing?
  18  */
  19
  20 #define in_interrupt()                                          \
  21 ({                                                              \
  22         int __cpu = smp_processor_id();                         \
  23         (local_irq_count(__cpu) + local_bh_count(__cpu)) != 0;  \
  24 })
  25
  26 #ifndef __SMP__
  27
  28 #define hardirq_trylock(cpu)    (local_irq_count(cpu) == 0)
  29 #define hardirq_endlock(cpu)    ((void) 0)
  30
  31 #define hardirq_enter(cpu, irq) (local_irq_count(cpu)++)
  32 #define hardirq_exit(cpu, irq)  (local_irq_count(cpu)--)
  33
  34 #define synchronize_irq()       barrier()
  35
  36 #else
  37
  38 #include <asm/atomic.h>
  39 #include <linux/spinlock.h>
  40 #include <asm/smp.h>
  41
  42 extern int global_irq_holder;
  43 extern spinlock_t global_irq_lock;
  44 extern atomic_t global_irq_count;
  45
  46 static inline void release_irqlock(int cpu)
  47 {
  48         /* if we didn't own the irq lock, just ignore.. */
  49         if (global_irq_holder == cpu) {
  50                 global_irq_holder = NO_PROC_ID;
  51                 spin_unlock(&global_irq_lock);
  52         }
  53 }
  54
  55 static inline void hardirq_enter(int cpu, int irq)
  56 {
  57         ++local_irq_count(cpu);
  58         atomic_inc(&global_irq_count);
  59 }
  60
  61 static inline void hardirq_exit(int cpu, int irq)
  62 {
  63         atomic_dec(&global_irq_count);
  64         --local_irq_count(cpu);
  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)  ((void)0)
  74
  75 extern void synchronize_irq(void);
  76
  77 #endif /* __SMP__ */
  78 #endif /* _ALPHA_HARDIRQ_H */