1#ifndef _ALPHA_SPINLOCK_H 2#define _ALPHA_SPINLOCK_H 3 4#include <linux/config.h> 5#include <asm/system.h> 6#include <linux/kernel.h> 7#include <asm/current.h> 8 9 10/* 11 * Simple spin lock operations. There are two variants, one clears IRQ's 12 * on the local processor, one does not. 13 * 14 * We make no fairness assumptions. They have a cost. 15 */ 16 17typedef struct { 18 volatile unsigned int lock /*__attribute__((aligned(32))) */; 19#if CONFIG_DEBUG_SPINLOCK 20 int on_cpu; 21 int line_no; 22 void *previous; 23 struct task_struct * task; 24 const char *base_file; 25#endif 26} spinlock_t; 27 28#if CONFIG_DEBUG_SPINLOCK 29#define SPIN_LOCK_UNLOCKED (spinlock_t) {0, -1, 0, 0, 0, 0} 30#define spin_lock_init(x) \ 31 ((x)->lock = 0, (x)->on_cpu = -1, (x)->previous = 0, (x)->task = 0) 32#else 33#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } 34#define spin_lock_init(x) ((x)->lock = 0) 35#endif 36 37#define spin_is_locked(x) ((x)->lock != 0) 38#define spin_unlock_wait(x) ({ do { barrier(); } while ((x)->lock); }) 39 40#if CONFIG_DEBUG_SPINLOCK 41extern void spin_unlock(spinlock_t * lock); 42extern void debug_spin_lock(spinlock_t * lock, const char *, int); 43extern int debug_spin_trylock(spinlock_t * lock, const char *, int); 44 45#define spin_lock(LOCK) debug_spin_lock(LOCK, __BASE_FILE__, __LINE__) 46#define spin_trylock(LOCK) debug_spin_trylock(LOCK, __BASE_FILE__, __LINE__) 47 48#define spin_lock_own(LOCK, LOCATION) \ 49do { \ 50 if (!((LOCK)->lock && (LOCK)->on_cpu == smp_processor_id())) \ 51 printk("%s: called on %d from %p but lock %s on %d\n", \ 52 LOCATION, smp_processor_id(), \ 53 __builtin_return_address(0), \ 54 (LOCK)->lock ? "taken" : "freed", (LOCK)->on_cpu); \ 55} while (0) 56#else 57static inline void spin_unlock(spinlock_t * lock) 58{ 59 mb(); 60 lock->lock = 0; 61} 62 63static inline void spin_lock(spinlock_t * lock) 64{ 65 long tmp; 66 67 /* Use sub-sections to put the actual loop at the end 68 of this object file's text section so as to perfect 69 branch prediction. */ 70 __asm__ __volatile__( 71 "1: ldl_l %0,%1\n" 72 " blbs %0,2f\n" 73 " or %0,1,%0\n" 74 " stl_c %0,%1\n" 75 " beq %0,2f\n" 76 " mb\n" 77 ".subsection 2\n" 78 "2: ldl %0,%1\n" 79 " blbs %0,2b\n" 80 " br 1b\n" 81 ".previous" 82 : "=&r" (tmp), "=m" (lock->lock) 83 : "m"(lock->lock) : "memory"); 84} 85 86#define spin_trylock(lock) (!test_and_set_bit(0,(lock))) 87#define spin_lock_own(LOCK, LOCATION) ((void)0) 88#endif /* CONFIG_DEBUG_SPINLOCK */ 89 90/***********************************************************/ 91 92typedef struct { 93 volatile int write_lock:1, read_counter:31; 94} /*__attribute__((aligned(32)))*/ rwlock_t; 95 96#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 } 97 98#define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0) 99 100#if CONFIG_DEBUG_RWLOCK 101extern void write_lock(rwlock_t * lock); 102extern void read_lock(rwlock_t * lock); 103#else 104static inline void write_lock(rwlock_t * lock) 105{ 106 long regx; 107 108 __asm__ __volatile__( 109 "1: ldl_l %1,%0\n" 110 " bne %1,6f\n" 111 " or $31,1,%1\n" 112 " stl_c %1,%0\n" 113 " beq %1,6f\n" 114 " mb\n" 115 ".subsection 2\n" 116 "6: ldl %1,%0\n" 117 " bne %1,6b\n" 118 " br 1b\n" 119 ".previous" 120 : "=m" (*(volatile int *)lock), "=&r" (regx) 121 : "0" (*(volatile int *)lock) : "memory"); 122} 123 124static inline void read_lock(rwlock_t * lock) 125{ 126 long regx; 127 128 __asm__ __volatile__( 129 "1: ldl_l %1,%0\n" 130 " blbs %1,6f\n" 131 " subl %1,2,%1\n" 132 " stl_c %1,%0\n" 133 " beq %1,6f\n" 134 "4: mb\n" 135 ".subsection 2\n" 136 "6: ldl %1,%0\n" 137 " blbs %1,6b\n" 138 " br 1b\n" 139 ".previous" 140 : "=m" (*(volatile int *)lock), "=&r" (regx) 141 : "m" (*(volatile int *)lock) : "memory"); 142} 143#endif /* CONFIG_DEBUG_RWLOCK */ 144 145static inline void write_unlock(rwlock_t * lock) 146{ 147 mb(); 148 *(volatile int *)lock = 0; 149} 150 151static inline void read_unlock(rwlock_t * lock) 152{ 153 long regx; 154 __asm__ __volatile__( 155 " mb\n" 156 "1: ldl_l %1,%0\n" 157 " addl %1,2,%1\n" 158 " stl_c %1,%0\n" 159 " beq %1,6f\n" 160 ".subsection 2\n" 161 "6: br 1b\n" 162 ".previous" 163 : "=m" (*(volatile int *)lock), "=&r" (regx) 164 : "m" (*(volatile int *)lock) : "memory"); 165} 166 167#endif /* _ALPHA_SPINLOCK_H */ 168