cp/nucleus/spinlock.c

   1 /*
   2  * (C) Copyright 2007-2010  Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
   3  *
   4  * This file is released under the GPLv2.  See the COPYING file for more
   5  * details.
   6  */
   7
   8 #include <interrupt.h>
   9 #include <spinlock.h>
  10
  11 void __spin_lock_wait(spinlock_t *lp, unsigned int pc)
  12 {
  13         while (1) {
  14                 if (__compare_and_swap(&lp->lock, 0, pc) == 0)
  15                         return;
  16         }
  17 }
  18
  19 int __spin_trylock_retry(spinlock_t *lp, unsigned int pc)
  20 {
  21         int count = SPIN_RETRY;
  22
  23         while (count-- > 0)
  24                 if (__compare_and_swap(&lp->lock, 0, pc) == 0)
  25                         return 1;
  26         return 0;
  27 }
  28
  29 /**
  30  * spin_lock_intsave - disable interrupts and lock
  31  * @lock:       lock to lock
  32  * @mask:       pointer to where interrupt mask will be stored
  33  */
  34 void spin_lock_intsave(spinlock_t *lock, unsigned long *mask)
  35 {
  36         *mask = local_int_disable();
  37         spin_lock(lock);
  38 }
  39
  40 /**
  41  * spin_unlock_intrestore - unlock and restore interrupt flags flags
  42  * @lock:       lock to unlock
  43  * @mask:       mask to restore
  44  */
  45 void spin_unlock_intrestore(spinlock_t *lock, unsigned long mask)
  46 {
  47         spin_unlock(lock);
  48         local_int_restore(mask);
  49 }
  50