include/asm-ppc/spinlock.h

   1 #ifndef __ASM_SPINLOCK_H
   2 #define __ASM_SPINLOCK_H
   3
   4 #include <asm/system.h>
   5
   6 /*
   7  * Simple spin lock operations.
   8  */
   9
  10 typedef struct {
  11         volatile unsigned long lock;
  12 #ifdef CONFIG_DEBUG_SPINLOCK
  13         volatile unsigned long owner_pc;
  14         volatile unsigned long owner_cpu;
  15 #endif
  16 } spinlock_t;
  17
  18 #ifdef __KERNEL__
  19 #ifdef CONFIG_DEBUG_SPINLOCK
  20 #define SPINLOCK_DEBUG_INIT     , 0, 0
  21 #else
  22 #define SPINLOCK_DEBUG_INIT     /* */
  23 #endif
  24
  25 #define SPIN_LOCK_UNLOCKED      (spinlock_t) { 0 SPINLOCK_DEBUG_INIT }
  26
  27 #define spin_lock_init(x)       do { *(x) = SPIN_LOCK_UNLOCKED; } while(0)
  28 #define spin_is_locked(x)       ((x)->lock != 0)
  29 #define spin_unlock_wait(x)     do { barrier(); } while(spin_is_locked(x))
  30 #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
  31
  32 #ifndef CONFIG_DEBUG_SPINLOCK
  33
  34 static inline void _raw_spin_lock(spinlock_t *lock)
  35 {
  36         unsigned long tmp;
  37
  38         __asm__ __volatile__(
  39         "b      1f              # spin_lock\n\
  40 2:      lwzx    %0,0,%1\n\
  41         cmpwi   0,%0,0\n\
  42         bne+    2b\n\
  43 1:      lwarx   %0,0,%1\n\
  44         cmpwi   0,%0,0\n\
  45         bne-    2b\n"
  46         PPC405_ERR77(0,%1)
  47 "       stwcx.  %2,0,%1\n\
  48         bne-    2b\n\
  49         isync"
  50         : "=&r"(tmp)
  51         : "r"(&lock->lock), "r"(1)
  52         : "cr0", "memory");
  53 }
  54
  55 static inline void _raw_spin_unlock(spinlock_t *lock)
  56 {
  57         __asm__ __volatile__("eieio             # spin_unlock": : :"memory");
  58         lock->lock = 0;
  59 }
  60
  61 #define _raw_spin_trylock(l) (!test_and_set_bit(0,&(l)->lock))
  62
  63 #else
  64
  65 extern void _raw_spin_lock(spinlock_t *lock);
  66 extern void _raw_spin_unlock(spinlock_t *lock);
  67 extern int _raw_spin_trylock(spinlock_t *lock);
  68
  69 #endif
  70
  71 /*
  72  * Read-write spinlocks, allowing multiple readers
  73  * but only one writer.
  74  *
  75  * NOTE! it is quite common to have readers in interrupts
  76  * but no interrupt writers. For those circumstances we
  77  * can "mix" irq-safe locks - any writer needs to get a
  78  * irq-safe write-lock, but readers can get non-irqsafe
  79  * read-locks.
  80  */
  81 typedef struct {
  82         volatile unsigned long lock;
  83 #ifdef CONFIG_DEBUG_SPINLOCK
  84         volatile unsigned long owner_pc;
  85 #endif
  86 } rwlock_t;
  87
  88 #ifdef CONFIG_DEBUG_SPINLOCK
  89 #define RWLOCK_DEBUG_INIT     , 0
  90 #else
  91 #define RWLOCK_DEBUG_INIT     /* */
  92 #endif
  93
  94 #define RW_LOCK_UNLOCKED (rwlock_t) { 0 RWLOCK_DEBUG_INIT }
  95 #define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0)
  96
  97 #define rwlock_is_locked(x)     ((x)->lock != 0)
  98
  99 #ifndef CONFIG_DEBUG_SPINLOCK
 100
 101 static __inline__ void _raw_read_lock(rwlock_t *rw)
 102 {
 103         unsigned int tmp;
 104
 105         __asm__ __volatile__(
 106         "b      2f              # read_lock\n\
 107 1:      lwzx    %0,0,%1\n\
 108         cmpwi   0,%0,0\n\
 109         blt+    1b\n\
 110 2:      lwarx   %0,0,%1\n\
 111         addic.  %0,%0,1\n\
 112         ble-    1b\n"
 113         PPC405_ERR77(0,%1)
 114 "       stwcx.  %0,0,%1\n\
 115         bne-    2b\n\
 116         isync"
 117         : "=&r"(tmp)
 118         : "r"(&rw->lock)
 119         : "cr0", "memory");
 120 }
 121
 122 static __inline__ void _raw_read_unlock(rwlock_t *rw)
 123 {
 124         unsigned int tmp;
 125
 126         __asm__ __volatile__(
 127         "eieio                  # read_unlock\n\
 128 1:      lwarx   %0,0,%1\n\
 129         addic   %0,%0,-1\n"
 130         PPC405_ERR77(0,%1)
 131 "       stwcx.  %0,0,%1\n\
 132         bne-    1b"
 133         : "=&r"(tmp)
 134         : "r"(&rw->lock)
 135         : "cr0", "memory");
 136 }
 137
 138 static __inline__ int _raw_write_trylock(rwlock_t *rw)
 139 {
 140         unsigned int tmp;
 141
 142         __asm__ __volatile__(
 143 "2:     lwarx   %0,0,%1         # write_trylock\n\
 144         cmpwi   0,%0,0\n\
 145         bne-    1f\n"
 146         PPC405_ERR77(0,%1)
 147 "       stwcx.  %2,0,%1\n\
 148         bne-    2b\n\
 149         isync\n\
 150 1:"
 151         : "=&r"(tmp)
 152         : "r"(&rw->lock), "r"(-1)
 153         : "cr0", "memory");
 154
 155         return tmp == 0;
 156 }
 157
 158 static __inline__ void _raw_write_lock(rwlock_t *rw)
 159 {
 160         unsigned int tmp;
 161
 162         __asm__ __volatile__(
 163         "b      2f              # write_lock\n\
 164 1:      lwzx    %0,0,%1\n\
 165         cmpwi   0,%0,0\n\
 166         bne+    1b\n\
 167 2:      lwarx   %0,0,%1\n\
 168         cmpwi   0,%0,0\n\
 169         bne-    1b\n"
 170         PPC405_ERR77(0,%1)
 171 "       stwcx.  %2,0,%1\n\
 172         bne-    2b\n\
 173         isync"
 174         : "=&r"(tmp)
 175         : "r"(&rw->lock), "r"(-1)
 176         : "cr0", "memory");
 177 }
 178
 179 static __inline__ void _raw_write_unlock(rwlock_t *rw)
 180 {
 181         __asm__ __volatile__("eieio             # write_unlock": : :"memory");
 182         rw->lock = 0;
 183 }
 184
 185 #else
 186
 187 extern void _raw_read_lock(rwlock_t *rw);
 188 extern void _raw_read_unlock(rwlock_t *rw);
 189 extern void _raw_write_lock(rwlock_t *rw);
 190 extern void _raw_write_unlock(rwlock_t *rw);
 191 extern int _raw_write_trylock(rwlock_t *rw);
 192
 193 #endif
 194
 195 #endif /* __ASM_SPINLOCK_H */
 196 #endif /* __KERNEL__ */