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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 99 100 101 102 103 104 105 106 107 108 109 110 | #ifndef __ASM_SOFTIRQ_H #define __ASM_SOFTIRQ_H #include <asm/atomic.h> #include <asm/hardirq.h> extern unsigned int local_bh_count[NR_CPUS]; #define get_active_bhs() (bh_mask & bh_active) #define clear_active_bhs(x) atomic_clear_mask((x),&bh_active) extern inline void init_bh(int nr, void (*routine)(void)) { bh_base[nr] = routine; bh_mask_count[nr] = 0; bh_mask |= 1 << nr; } extern inline void remove_bh(int nr) { bh_base[nr] = NULL; bh_mask &= ~(1 << nr); } extern inline void mark_bh(int nr) { set_bit(nr, &bh_active); } #ifdef __SMP__ /* * The locking mechanism for base handlers, to prevent re-entrancy, * is entirely private to an implementation, it should not be * referenced at all outside of this file. */ extern atomic_t global_bh_lock; extern atomic_t global_bh_count; extern void synchronize_bh(void); static inline void start_bh_atomic(void) { atomic_inc(&global_bh_lock); synchronize_bh(); } static inline void end_bh_atomic(void) { atomic_dec(&global_bh_lock); } /* These are for the IRQs testing the lock */ static inline int softirq_trylock(int cpu) { if (!test_and_set_bit(0,&global_bh_count)) { if (atomic_read(&global_bh_lock) == 0) { ++local_bh_count[cpu]; return 1; } clear_bit(0,&global_bh_count); } return 0; } static inline void softirq_endlock(int cpu) { local_bh_count[cpu]--; clear_bit(0,&global_bh_count); } #else extern inline void start_bh_atomic(void) { local_bh_count[smp_processor_id()]++; barrier(); } extern inline void end_bh_atomic(void) { barrier(); local_bh_count[smp_processor_id()]--; } /* These are for the irq's testing the lock */ #define softirq_trylock(cpu) (local_bh_count[cpu] ? 0 : (local_bh_count[cpu]=1)) #define softirq_endlock(cpu) (local_bh_count[cpu] = 0) #define synchronize_bh() barrier() #endif /* SMP */ /* * These use a mask count to correctly handle * nested disable/enable calls */ extern inline void disable_bh(int nr) { bh_mask &= ~(1 << nr); bh_mask_count[nr]++; synchronize_bh(); } extern inline void enable_bh(int nr) { if (!--bh_mask_count[nr]) bh_mask |= 1 << nr; } #endif /* __ASM_SOFTIRQ_H */ |