kitten/include/lwk/spinlock.h

   1 #ifndef _LWK_SPINLOCK_H
   2 #define _LWK_SPINLOCK_H
   3
   4 /*
   5  * include/lwk/spinlock.h - generic spinlock/rwlock declarations
   6  *
   7  * here's the role of the various spinlock/rwlock related include files:
   8  *
   9  *  arch/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
  10  *                         initializers
  11  *
  12  *  lwk/spinlock_types.h:
  13  *                         defines the generic type and initializers
  14  *
  15  *  arch/spinlock.h:       contains the __raw_spin_*()/etc. lowlevel
  16  *                         implementations, mostly inline assembly code
  17  *
  18  *  lwk/spinlock_api_smp.h:
  19  *                         contains the prototypes for the _spin_*() APIs.
  20  *
  21  *  lwk/spinlock.h:        builds the final spin_*() APIs.
  22  *
  23  *  lwk/spinlock.h:        builds the final spin_*() APIs.
  24  */
  25
  26 #include <lwk/kernel.h>
  27 #include <lwk/linkage.h>
  28 #include <lwk/compiler.h>
  29 #include <lwk/stringify.h>
  30 #include <arch/system.h>
  31
  32 /*
  33  * Must define these before including other files, inline functions need them
  34  */
  35 #define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME
  36
  37 #define LOCK_SECTION_START(extra)               \
  38         ".subsection 1\n\t"                     \
  39         extra                                   \
  40         ".ifndef " LOCK_SECTION_NAME "\n\t"     \
  41         LOCK_SECTION_NAME ":\n\t"               \
  42         ".endif\n"
  43
  44 #define LOCK_SECTION_END                        \
  45         ".previous\n\t"
  46
  47 #define __lockfunc fastcall __attribute__((section(".spinlock.text")))
  48
  49 /*
  50  * Pull the raw_spinlock_t and raw_rwlock_t definitions:
  51  */
  52 #include <lwk/spinlock_types.h>
  53
  54 extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
  55
  56 /*
  57  * Pull the __raw*() functions/declarations:
  58  */
  59 # include <arch/spinlock.h>
  60
  61 #define spin_lock_init(lock)    do { *(lock) = (spinlock_t)SPIN_LOCK_UNLOCKED; } while (0)
  62 #define rwlock_init(lock)       do { *(lock) = (rwlock_t)RW_LOCK_UNLOCKED; } while (0)
  63
  64 #define spin_is_locked(lock)    __raw_spin_is_locked(&(lock)->raw_lock)
  65
  66 /**
  67  * spin_unlock_wait - wait until the spinlock gets unlocked
  68  * @lock: the spinlock in question.
  69  */
  70 #define spin_unlock_wait(lock)  __raw_spin_unlock_wait(&(lock)->raw_lock)
  71
  72 /*
  73  * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
  74  */
  75 #include <lwk/spinlock_api_smp.h>
  76
  77 #ifdef CONFIG_DEBUG_SPINLOCK
  78  extern void _raw_spin_lock(spinlock_t *lock);
  79 #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
  80  extern int _raw_spin_trylock(spinlock_t *lock);
  81  extern void _raw_spin_unlock(spinlock_t *lock);
  82
  83  extern void _raw_read_lock(rwlock_t *lock);
  84  extern int _raw_read_trylock(rwlock_t *lock);
  85  extern void _raw_read_unlock(rwlock_t *lock);
  86  extern void _raw_write_lock(rwlock_t *lock);
  87  extern int _raw_write_trylock(rwlock_t *lock);
  88  extern void _raw_write_unlock(rwlock_t *lock);
  89 #else
  90 # define _raw_spin_unlock(lock)         __raw_spin_unlock(&(lock)->raw_lock)
  91 # define _raw_spin_trylock(lock)        __raw_spin_trylock(&(lock)->raw_lock)
  92 # define _raw_spin_lock(lock)           __raw_spin_lock(&(lock)->raw_lock)
  93 # define _raw_spin_lock_flags(lock, flags) \
  94                 __raw_spin_lock_flags(&(lock)->raw_lock, *(flags))
  95 # define _raw_read_lock(rwlock)         __raw_read_lock(&(rwlock)->raw_lock)
  96 # define _raw_write_lock(rwlock)        __raw_write_lock(&(rwlock)->raw_lock)
  97 # define _raw_read_unlock(rwlock)       __raw_read_unlock(&(rwlock)->raw_lock)
  98 # define _raw_write_unlock(rwlock)      __raw_write_unlock(&(rwlock)->raw_lock)
  99 # define _raw_read_trylock(rwlock)      __raw_read_trylock(&(rwlock)->raw_lock)
 100 # define _raw_write_trylock(rwlock)     __raw_write_trylock(&(rwlock)->raw_lock)
 101 #endif
 102
 103 #define read_can_lock(rwlock)           __raw_read_can_lock(&(rwlock)->raw_lock)
 104 #define write_can_lock(rwlock)          __raw_write_can_lock(&(rwlock)->raw_lock)
 105
 106 /*
 107  * Define the various spin_lock and rw_lock methods.
 108  */
 109 #define spin_trylock(lock)              __cond_lock(_spin_trylock(lock))
 110 #define read_trylock(lock)              __cond_lock(_read_trylock(lock))
 111 #define write_trylock(lock)             __cond_lock(_write_trylock(lock))
 112
 113 #define spin_lock(lock)                 _spin_lock(lock)
 114 #define write_lock(lock)                _write_lock(lock)
 115 #define read_lock(lock)                 _read_lock(lock)
 116
 117 #define spin_lock_irqsave(lock, flags)  flags = _spin_lock_irqsave(lock)
 118 #define read_lock_irqsave(lock, flags)  flags = _read_lock_irqsave(lock)
 119 #define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock)
 120
 121 #define spin_lock_irq(lock)             _spin_lock_irq(lock)
 122 #define spin_lock_bh(lock)              _spin_lock_bh(lock)
 123
 124 #define read_lock_irq(lock)             _read_lock_irq(lock)
 125 #define read_lock_bh(lock)              _read_lock_bh(lock)
 126
 127 #define write_lock_irq(lock)            _write_lock_irq(lock)
 128 #define write_lock_bh(lock)             _write_lock_bh(lock)
 129
 130 /*
 131  * We inline the unlock functions in the nondebug case:
 132  */
 133 #if defined(CONFIG_DEBUG_SPINLOCK)
 134 # define spin_unlock(lock)              _spin_unlock(lock)
 135 # define read_unlock(lock)              _read_unlock(lock)
 136 # define write_unlock(lock)             _write_unlock(lock)
 137 #else
 138 # define spin_unlock(lock)              __raw_spin_unlock(&(lock)->raw_lock)
 139 # define read_unlock(lock)              __raw_read_unlock(&(lock)->raw_lock)
 140 # define write_unlock(lock)             __raw_write_unlock(&(lock)->raw_lock)
 141 #endif
 142
 143 #if defined(CONFIG_DEBUG_SPINLOCK)
 144 # define spin_unlock_irq(lock)          _spin_unlock_irq(lock)
 145 # define read_unlock_irq(lock)          _read_unlock_irq(lock)
 146 # define write_unlock_irq(lock)         _write_unlock_irq(lock)
 147 #else
 148 # define spin_unlock_irq(lock) \
 149     do { __raw_spin_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
 150 # define read_unlock_irq(lock) \
 151     do { __raw_read_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
 152 # define write_unlock_irq(lock) \
 153     do { __raw_write_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
 154 #endif
 155
 156 #define spin_unlock_irqrestore(lock, flags) \
 157                                         _spin_unlock_irqrestore(lock, flags)
 158 #define spin_unlock_bh(lock)            _spin_unlock_bh(lock)
 159
 160 #define read_unlock_irqrestore(lock, flags) \
 161                                         _read_unlock_irqrestore(lock, flags)
 162 #define read_unlock_bh(lock)            _read_unlock_bh(lock)
 163
 164 #define write_unlock_irqrestore(lock, flags) \
 165                                         _write_unlock_irqrestore(lock, flags)
 166 #define write_unlock_bh(lock)           _write_unlock_bh(lock)
 167
 168 #define spin_trylock_bh(lock)           __cond_lock(_spin_trylock_bh(lock))
 169
 170 #define spin_trylock_irq(lock) \
 171 ({ \
 172         local_irq_disable(); \
 173         _spin_trylock(lock) ? \
 174         1 : ({ local_irq_enable(); 0;  }); \
 175 })
 176
 177 #define spin_trylock_irqsave(lock, flags) \
 178 ({ \
 179         local_irq_save(flags); \
 180         _spin_trylock(lock) ? \
 181         1 : ({ local_irq_restore(flags); 0; }); \
 182 })
 183
 184 /*
 185  * Pull the atomic_t declaration:
 186  * (asm-mips/atomic.h needs above definitions)
 187  */
 188 #include <arch/atomic.h>
 189 /**
 190  * atomic_dec_and_lock - lock on reaching reference count zero
 191  * @atomic: the atomic counter
 192  * @lock: the spinlock in question
 193  */
 194 extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
 195 #define atomic_dec_and_lock(atomic, lock) \
 196                 __cond_lock(_atomic_dec_and_lock(atomic, lock))
 197
 198 /**
 199  * spin_can_lock - would spin_trylock() succeed?
 200  * @lock: the spinlock in question.
 201  */
 202 #define spin_can_lock(lock)     (!spin_is_locked(lock))
 203
 204 #endif /* _LWK_SPINLOCK_H */