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/config.h>
  10 #include <linux/threads.h>
  11 #include <linux/brlock.h>
  12 #include <linux/spinlock.h>
  13
  14 #ifndef CONFIG_SMP
  15 extern unsigned int __local_irq_count;
  16 #define local_irq_count(cpu)    __local_irq_count
  17 #define irq_enter(cpu, irq)     (__local_irq_count++)
  18 #define irq_exit(cpu, irq)      (__local_irq_count--)
  19 #else
  20 #define local_irq_count(cpu)    (__brlock_array[cpu][BR_GLOBALIRQ_LOCK])
  21 #define irq_enter(cpu, irq)     br_read_lock(BR_GLOBALIRQ_LOCK)
  22 #define irq_exit(cpu, irq)      br_read_unlock(BR_GLOBALIRQ_LOCK)
  23 #endif
  24
  25 /*
  26  * Are we in an interrupt context? Either doing bottom half
  27  * or hardware interrupt processing?  On any cpu?
  28  */
  29 #define in_interrupt() ((local_irq_count(smp_processor_id()) + \
  30                          local_bh_count(smp_processor_id())) != 0)
  31
  32 /* This tests only the local processors hw IRQ context disposition.  */
  33 #define in_irq() (local_irq_count(smp_processor_id()) != 0)
  34
  35 #ifndef CONFIG_SMP
  36
  37 #define hardirq_trylock(cpu)    ((void)(cpu), local_irq_count(smp_processor_id()) == 0)
  38 #define hardirq_endlock(cpu)    do { (void)(cpu); } while(0)
  39
  40 #define hardirq_enter(cpu)      ((void)(cpu), local_irq_count(smp_processor_id())++)
  41 #define hardirq_exit(cpu)       ((void)(cpu), local_irq_count(smp_processor_id())--)
  42
  43 #define synchronize_irq()       barrier()
  44
  45 #else /* (CONFIG_SMP) */
  46
  47 static __inline__ int irqs_running(void)
  48 {
  49         enum brlock_indices idx = BR_GLOBALIRQ_LOCK;
  50         int i, count = 0;
  51
  52         for (i = 0; i < smp_num_cpus; i++)
  53                 count += (__brlock_array[cpu_logical_map(i)][idx] != 0);
  54
  55         return count;
  56 }
  57
  58 extern unsigned char global_irq_holder;
  59
  60 static inline void release_irqlock(int cpu)
  61 {
  62         /* if we didn't own the irq lock, just ignore... */
  63         if(global_irq_holder == (unsigned char) cpu) {
  64                 global_irq_holder = NO_PROC_ID;
  65                 br_write_unlock(BR_GLOBALIRQ_LOCK);
  66         }
  67 }
  68
  69 static inline int hardirq_trylock(int cpu)
  70 {
  71         spinlock_t *lock = &__br_write_locks[BR_GLOBALIRQ_LOCK].lock;
  72
  73         return (!irqs_running() && !spin_is_locked(lock));
  74 }
  75
  76 #define hardirq_endlock(cpu)    do { (void)(cpu); } while (0)
  77
  78 extern void synchronize_irq(void);
  79
  80 #endif /* CONFIG_SMP */
  81
  82 #endif /* !(__SPARC64_HARDIRQ_H) */