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#ifdef __KERNEL__
#ifndef __ASM_HARDIRQ_H
#define __ASM_HARDIRQ_H
#include <linux/config.h>
#include <asm/smp.h>
/* entry.S is sensitive to the offsets of these fields */
/* The __last_jiffy_stamp field is needed to ensure that no decrementer
* interrupt is lost on SMP machines. Since on most CPUs it is in the same
* cache line as local_irq_count, it is cheap to access and is also used on UP
* for uniformity.
*/
typedef struct {
unsigned int __softirq_active;
unsigned int __softirq_mask;
unsigned int __local_irq_count;
unsigned int __local_bh_count;
unsigned int __syscall_count;
unsigned int __last_jiffy_stamp;
} ____cacheline_aligned irq_cpustat_t;
#include <linux/irq_cpustat.h> /* Standard mappings for irq_cpustat_t above */
#define last_jiffy_stamp(cpu) __IRQ_STAT((cpu), __last_jiffy_stamp)
/*
* Are we in an interrupt context? Either doing bottom half
* or hardware interrupt processing?
*/
#define in_interrupt() ({ int __cpu = smp_processor_id(); \
(local_irq_count(__cpu) + local_bh_count(__cpu) != 0); })
#define in_irq() (local_irq_count(smp_processor_id()) != 0)
#ifndef CONFIG_SMP
#define hardirq_trylock(cpu) (local_irq_count(cpu) == 0)
#define hardirq_endlock(cpu) do { } while (0)
#define hardirq_enter(cpu) (local_irq_count(cpu)++)
#define hardirq_exit(cpu) (local_irq_count(cpu)--)
#define synchronize_irq() do { } while (0)
#else /* CONFIG_SMP */
#include <asm/atomic.h>
extern unsigned char global_irq_holder;
extern unsigned volatile long global_irq_lock;
extern atomic_t global_irq_count;
static inline void release_irqlock(int cpu)
{
/* if we didn't own the irq lock, just ignore.. */
if (global_irq_holder == (unsigned char) cpu) {
global_irq_holder = NO_PROC_ID;
clear_bit(0,&global_irq_lock);
}
}
static inline void hardirq_enter(int cpu)
{
unsigned int loops = 10000000;
++local_irq_count(cpu);
atomic_inc(&global_irq_count);
while (test_bit(0,&global_irq_lock)) {
if (cpu == global_irq_holder) {
printk("uh oh, interrupt while we hold global irq lock! (CPU %d)\n", cpu);
#ifdef CONFIG_XMON
xmon(0);
#endif
break;
}
if (loops-- == 0) {
printk("do_IRQ waiting for irq lock (holder=%d)\n", global_irq_holder);
#ifdef CONFIG_XMON
xmon(0);
#endif
}
}
}
static inline void hardirq_exit(int cpu)
{
atomic_dec(&global_irq_count);
--local_irq_count(cpu);
}
static inline int hardirq_trylock(int cpu)
{
return !atomic_read(&global_irq_count) && !test_bit(0,&global_irq_lock);
}
#define hardirq_endlock(cpu) do { } while (0)
extern void synchronize_irq(void);
#endif /* CONFIG_SMP */
#endif /* __ASM_HARDIRQ_H */
#endif /* __KERNEL__ */
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