LXR linux-old/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) 1998-2000 Anton Blanchard (anton@samba.org)
   5 */
   6
   7#ifndef __SPARC_HARDIRQ_H
   8#define __SPARC_HARDIRQ_H
   9
  10#include <linux/config.h>
  11#include <linux/threads.h>
  12#include <linux/brlock.h>
  13#include <linux/spinlock.h>
  14
  15/* entry.S is sensitive to the offsets of these fields */
  16typedef struct {
  17        unsigned int __softirq_pending;
  18        unsigned int __unused_1;
  19#ifndef CONFIG_SMP
  20        unsigned int __local_irq_count;
  21#else
  22        unsigned int __unused_on_SMP;   /* DaveM says use brlock for SMP irq. KAO */
  23#endif
  24        unsigned int __local_bh_count;
  25        unsigned int __syscall_count;
  26        struct task_struct * __ksoftirqd_task;
  27} ____cacheline_aligned irq_cpustat_t;
  28
  29#include <linux/irq_cpustat.h>  /* Standard mappings for irq_cpustat_t above */
  30/* Note that local_irq_count() is replaced by sparc64 specific version for SMP */
  31
  32#ifndef CONFIG_SMP
  33#define irq_enter(cpu, irq)     ((void)(irq), local_irq_count(cpu)++)
  34#define irq_exit(cpu, irq)      ((void)(irq), local_irq_count(cpu)--)
  35#else
  36#undef local_irq_count
  37#define local_irq_count(cpu)    (__brlock_array[cpu][BR_GLOBALIRQ_LOCK])
  38#define irq_enter(cpu, irq)     br_read_lock(BR_GLOBALIRQ_LOCK)
  39#define irq_exit(cpu, irq)      br_read_unlock(BR_GLOBALIRQ_LOCK)
  40#endif
  41
  42/*
  43 * Are we in an interrupt context? Either doing bottom half
  44 * or hardware interrupt processing?
  45 */
  46#define in_interrupt() ((local_irq_count(smp_processor_id()) + \
  47                         local_bh_count(smp_processor_id())) != 0)
  48
  49/* This tests only the local processors hw IRQ context disposition.  */
  50#define in_irq() (local_irq_count(smp_processor_id()) != 0)
  51
  52#ifndef CONFIG_SMP
  53
  54#define hardirq_trylock(cpu)    ((void)(cpu), local_irq_count(smp_processor_id()) == 0)
  55#define hardirq_endlock(cpu)    do { (void)(cpu); } while(0)
  56
  57#define synchronize_irq()       barrier()
  58
  59#else /* (CONFIG_SMP) */
  60
  61static __inline__ int irqs_running(void)
  62{
  63        int i;
  64
  65        for (i = 0; i < smp_num_cpus; i++)
  66                if (local_irq_count(cpu_logical_map(i)))
  67                        return 1;
  68        return 0;
  69}
  70
  71extern unsigned char global_irq_holder;
  72
  73static inline void release_irqlock(int cpu)
  74{
  75        /* if we didn't own the irq lock, just ignore... */
  76        if(global_irq_holder == (unsigned char) cpu) {
  77                global_irq_holder = NO_PROC_ID;
  78                br_write_unlock(BR_GLOBALIRQ_LOCK);
  79        }
  80}
  81
  82static inline int hardirq_trylock(int cpu)
  83{
  84        spinlock_t *lock = &__br_write_locks[BR_GLOBALIRQ_LOCK].lock;
  85
  86        return (!local_irq_count(cpu) && !spin_is_locked(lock));
  87}
  88
  89#define hardirq_endlock(cpu)    do { (void)(cpu); } while (0)
  90
  91extern void synchronize_irq(void);
  92
  93#endif /* CONFIG_SMP */
  94
  95#endif /* __SPARC_HARDIRQ_H */
  96