include/asm-parisc/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 __PARISC_HARDIRQ_H
   8 #define __PARISC_HARDIRQ_H
   9
  10 #include <linux/config.h>
  11 #include <linux/threads.h>
  12
  13 typedef struct {
  14         unsigned int __softirq_active;
  15         unsigned int __softirq_mask;
  16         unsigned int __local_irq_count;
  17         unsigned int __local_bh_count;
  18         unsigned int __syscall_count;
  19 } ____cacheline_aligned irq_cpustat_t;
  20
  21 #include <linux/irq_cpustat.h>  /* Standard mappings for irq_cpustat_t above */
  22
  23 /*
  24  * Are we in an interrupt context? Either doing bottom half
  25  * or hardware interrupt processing?
  26  */
  27 #define in_interrupt() ({ int __cpu = smp_processor_id(); \
  28         (local_irq_count(__cpu) + local_bh_count(__cpu) != 0); })
  29
  30 #define in_irq() ({ int __cpu = smp_processor_id(); \
  31         (local_irq_count(__cpu) != 0); })
  32
  33 #ifndef CONFIG_SMP
  34
  35 #define hardirq_trylock(cpu)    (local_irq_count(cpu) == 0)
  36 #define hardirq_endlock(cpu)    do { } while (0)
  37
  38 #define irq_enter(cpu, irq)     (local_irq_count(cpu)++)
  39 #define irq_exit(cpu, irq)      (local_irq_count(cpu)--)
  40
  41 #define synchronize_irq()       barrier()
  42
  43 #else
  44
  45 #include <asm/atomic.h>
  46 #include <linux/spinlock.h>
  47 #include <asm/system.h>
  48 #include <asm/smp.h>
  49
  50 extern unsigned char global_irq_holder;
  51 extern spinlock_t global_irq_lock;
  52 extern atomic_t global_irq_count;
  53
  54 static inline void release_irqlock(int cpu)
  55 {
  56         /* if we didn't own the irq lock, just ignore.. */
  57         if (global_irq_holder == (unsigned char) cpu) {
  58                 global_irq_holder = NO_PROC_ID;
  59                 spin_unlock(&global_irq_lock);
  60         }
  61 }
  62
  63 static inline void irq_enter(int cpu)
  64 {
  65         ++local_irq_count(cpu);
  66         atomic_inc(&global_irq_count);
  67 }
  68
  69 static inline void irq_exit(int cpu)
  70 {
  71         atomic_dec(&global_irq_count);
  72         --local_irq_count(cpu);
  73 }
  74
  75 static inline int hardirq_trylock(int cpu)
  76 {
  77         return (! atomic_read(&global_irq_count) &&
  78                 ! spin_is_locked (&global_irq_lock));
  79 }
  80
  81 #define hardirq_endlock(cpu)    do { } while (0)
  82
  83 extern void synchronize_irq(void);
  84
  85 #endif /* CONFIG_SMP */
  86
  87 #endif /* __PARISC_HARDIRQ_H */