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@linuxcare.com)
   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 */
  16 typedef struct {
  17         unsigned int __softirq_active;
  18         unsigned int __softirq_mask;
  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 } ____cacheline_aligned irq_cpustat_t;
  27
  28 #include <linux/irq_cpustat.h>  /* Standard mappings for irq_cpustat_t above */
  29 /* Note that local_irq_count() is replaced by sparc64 specific version for SMP */
  30
  31 #ifndef CONFIG_SMP
  32 #define irq_enter(cpu, irq)     ((void)(irq), local_irq_count(cpu)++)
  33 #define irq_exit(cpu, irq)      ((void)(irq), local_irq_count(cpu)--)
  34 #else
  35 #undef local_irq_count
  36 #define local_irq_count(cpu)    (__brlock_array[cpu][BR_GLOBALIRQ_LOCK])
  37 #define irq_enter(cpu, irq)     br_read_lock(BR_GLOBALIRQ_LOCK)
  38 #define irq_exit(cpu, irq)      br_read_unlock(BR_GLOBALIRQ_LOCK)
  39 #endif
  40
  41 /*
  42  * Are we in an interrupt context? Either doing bottom half
  43  * or hardware interrupt processing?
  44  */
  45 #define in_interrupt() ((local_irq_count(smp_processor_id()) + \
  46                          local_bh_count(smp_processor_id())) != 0)
  47
  48 /* This tests only the local processors hw IRQ context disposition.  */
  49 #define in_irq() (local_irq_count(smp_processor_id()) != 0)
  50
  51 #ifndef CONFIG_SMP
  52
  53 #define hardirq_trylock(cpu)    ((void)(cpu), local_irq_count(smp_processor_id()) == 0)
  54 #define hardirq_endlock(cpu)    do { (void)(cpu); } while(0)
  55
  56 #define synchronize_irq()       barrier()
  57
  58 #else /* (CONFIG_SMP) */
  59
  60 static __inline__ int irqs_running(void)
  61 {
  62         int i;
  63
  64         for (i = 0; i < smp_num_cpus; i++)
  65                 if (local_irq_count(cpu_logical_map(i)))
  66                         return 1;
  67         return 0;
  68 }
  69
  70 extern unsigned char global_irq_holder;
  71
  72 static inline void release_irqlock(int cpu)
  73 {
  74         /* if we didn't own the irq lock, just ignore... */
  75         if(global_irq_holder == (unsigned char) cpu) {
  76                 global_irq_holder = NO_PROC_ID;
  77                 br_write_unlock(BR_GLOBALIRQ_LOCK);
  78         }
  79 }
  80
  81 static inline int hardirq_trylock(int cpu)
  82 {
  83         spinlock_t *lock = &__br_write_locks[BR_GLOBALIRQ_LOCK].lock;
  84
  85         return (!local_irq_count(cpu) && !spin_is_locked(lock));
  86 }
  87
  88 #define hardirq_endlock(cpu)    do { (void)(cpu); } while (0)
  89
  90 extern void synchronize_irq(void);
  91
  92 #endif /* CONFIG_SMP */
  93
  94 #endif /* __SPARC_HARDIRQ_H */