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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 | #ifndef _ALPHA_SPINLOCK_H #define _ALPHA_SPINLOCK_H #include <asm/system.h> #include <linux/kernel.h> #include <asm/current.h> #define DEBUG_SPINLOCK 0 #define DEBUG_RWLOCK 0 /* * Simple spin lock operations. There are two variants, one clears IRQ's * on the local processor, one does not. * * We make no fairness assumptions. They have a cost. */ typedef struct { volatile unsigned int lock /*__attribute__((aligned(32))) */; #if DEBUG_SPINLOCK int on_cpu; int line_no; void *previous; struct task_struct * task; const char *base_file; #endif } spinlock_t; #if DEBUG_SPINLOCK #define SPIN_LOCK_UNLOCKED (spinlock_t) {0, -1, 0, 0, 0, 0} #define spin_lock_init(x) \ ((x)->lock = 0, (x)->on_cpu = -1, (x)->previous = 0, (x)->task = 0) #else #define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } #define spin_lock_init(x) ((x)->lock = 0) #endif #define spin_is_locked(x) ((x)->lock != 0) #define spin_unlock_wait(x) ({ do { barrier(); } while ((x)->lock); }) #if DEBUG_SPINLOCK extern void spin_unlock(spinlock_t * lock); extern void debug_spin_lock(spinlock_t * lock, const char *, int); extern int debug_spin_trylock(spinlock_t * lock, const char *, int); #define spin_lock(LOCK) debug_spin_lock(LOCK, __BASE_FILE__, __LINE__) #define spin_trylock(LOCK) debug_spin_trylock(LOCK, __BASE_FILE__, __LINE__) #define spin_lock_own(LOCK, LOCATION) \ do { \ if (!((LOCK)->lock && (LOCK)->on_cpu == smp_processor_id())) \ printk("%s: called on %d from %p but lock %s on %d\n", \ LOCATION, smp_processor_id(), \ __builtin_return_address(0), \ (LOCK)->lock ? "taken" : "freed", (LOCK)->on_cpu); \ } while (0) #else static inline void spin_unlock(spinlock_t * lock) { mb(); lock->lock = 0; } static inline void spin_lock(spinlock_t * lock) { long tmp; /* Use sub-sections to put the actual loop at the end of this object file's text section so as to perfect branch prediction. */ __asm__ __volatile__( "1: ldl_l %0,%1\n" " blbs %0,2f\n" " or %0,1,%0\n" " stl_c %0,%1\n" " beq %0,2f\n" " mb\n" ".subsection 2\n" "2: ldl %0,%1\n" " blbs %0,2b\n" " br 1b\n" ".previous" : "=&r" (tmp), "=m" (lock->lock) : "m"(lock->lock) : "memory"); } #define spin_trylock(lock) (!test_and_set_bit(0,(lock))) #define spin_lock_own(LOCK, LOCATION) ((void)0) #endif /* DEBUG_SPINLOCK */ /***********************************************************/ typedef struct { volatile int write_lock:1, read_counter:31; } /*__attribute__((aligned(32)))*/ rwlock_t; #define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 } #define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0) #if DEBUG_RWLOCK extern void write_lock(rwlock_t * lock); extern void read_lock(rwlock_t * lock); #else static inline void write_lock(rwlock_t * lock) { long regx; __asm__ __volatile__( "1: ldl_l %1,%0\n" " bne %1,6f\n" " or $31,1,%1\n" " stl_c %1,%0\n" " beq %1,6f\n" " mb\n" ".subsection 2\n" "6: ldl %1,%0\n" " bne %1,6b\n" " br 1b\n" ".previous" : "=m" (*(volatile int *)lock), "=&r" (regx) : "0" (*(volatile int *)lock) : "memory"); } static inline void read_lock(rwlock_t * lock) { long regx; __asm__ __volatile__( "1: ldl_l %1,%0\n" " blbs %1,6f\n" " subl %1,2,%1\n" " stl_c %1,%0\n" " beq %1,6f\n" "4: mb\n" ".subsection 2\n" "6: ldl %1,%0\n" " blbs %1,6b\n" " br 1b\n" ".previous" : "=m" (*(volatile int *)lock), "=&r" (regx) : "m" (*(volatile int *)lock) : "memory"); } #endif /* DEBUG_RWLOCK */ static inline void write_unlock(rwlock_t * lock) { mb(); *(volatile int *)lock = 0; } static inline void read_unlock(rwlock_t * lock) { long regx; __asm__ __volatile__( " mb\n" "1: ldl_l %1,%0\n" " addl %1,2,%1\n" " stl_c %1,%0\n" " beq %1,6f\n" ".subsection 2\n" "6: br 1b\n" ".previous" : "=m" (*(volatile int *)lock), "=&r" (regx) : "m" (*(volatile int *)lock) : "memory"); } #endif /* _ALPHA_SPINLOCK_H */ |