include/asm-i386/hardirq.h

   1 #ifndef __ASM_HARDIRQ_H
   2 #define __ASM_HARDIRQ_H
   3
   4 #include <linux/config.h>
   5 #include <linux/threads.h>
   6 #include <linux/irq.h>
   7
   8 /* entry.S is sensitive to the offsets of these fields */
   9 typedef struct {
  10         unsigned int __softirq_active;
  11         unsigned int __softirq_mask;
  12         unsigned int __local_irq_count;
  13         unsigned int __local_bh_count;
  14         unsigned int __syscall_count;
  15         unsigned int __nmi_count;       /* arch dependent */
  16 } ____cacheline_aligned irq_cpustat_t;
  17
  18 #include <linux/irq_cpustat.h>  /* Standard mappings for irq_cpustat_t above */
  19
  20 /*
  21  * Are we in an interrupt context? Either doing bottom half
  22  * or hardware interrupt processing?
  23  */
  24 #define in_interrupt() ({ int __cpu = smp_processor_id(); \
  25         (local_irq_count(__cpu) + local_bh_count(__cpu) != 0); })
  26
  27 #define in_irq() (local_irq_count(smp_processor_id()) != 0)
  28
  29 #ifndef CONFIG_SMP
  30
  31 #define hardirq_trylock(cpu)    (local_irq_count(cpu) == 0)
  32 #define hardirq_endlock(cpu)    do { } while (0)
  33
  34 #define irq_enter(cpu, irq)     (local_irq_count(cpu)++)
  35 #define irq_exit(cpu, irq)      (local_irq_count(cpu)--)
  36
  37 #define synchronize_irq()       barrier()
  38
  39 #else
  40
  41 #include <asm/atomic.h>
  42 #include <asm/smp.h>
  43
  44 extern unsigned char global_irq_holder;
  45 extern unsigned volatile long global_irq_lock; /* long for set_bit -RR */
  46
  47 static inline int irqs_running (void)
  48 {
  49         int i;
  50
  51         for (i = 0; i < smp_num_cpus; i++)
  52                 if (local_irq_count(i))
  53                         return 1;
  54         return 0;
  55 }
  56
  57 static inline void release_irqlock(int cpu)
  58 {
  59         /* if we didn't own the irq lock, just ignore.. */
  60         if (global_irq_holder == (unsigned char) cpu) {
  61                 global_irq_holder = NO_PROC_ID;
  62                 clear_bit(0,&global_irq_lock);
  63         }
  64 }
  65
  66 static inline void irq_enter(int cpu, int irq)
  67 {
  68         ++local_irq_count(cpu);
  69
  70         while (test_bit(0,&global_irq_lock)) {
  71                 /* nothing */;
  72         }
  73 }
  74
  75 static inline void irq_exit(int cpu, int irq)
  76 {
  77         --local_irq_count(cpu);
  78 }
  79
  80 static inline int hardirq_trylock(int cpu)
  81 {
  82         return !local_irq_count(cpu) && !test_bit(0,&global_irq_lock);
  83 }
  84
  85 #define hardirq_endlock(cpu)    do { } while (0)
  86
  87 extern void synchronize_irq(void);
  88
  89 #endif /* CONFIG_SMP */
  90
  91 #endif /* __ASM_HARDIRQ_H */