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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 | #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 long __softirq_pending; /* set_bit is used on this */ unsigned int __local_irq_count; unsigned int __local_bh_count; unsigned int __syscall_count; struct task_struct * __ksoftirqd_task; unsigned int __last_jiffy_stamp; unsigned int __heartbeat_count; unsigned int __heartbeat_reset; } ____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) #define heartbeat_count(cpu) __IRQ_STAT((cpu), __heartbeat_count) #define heartbeat_reset(cpu) __IRQ_STAT((cpu), __heartbeat_reset) /* * 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__ */ |