diff options
Diffstat (limited to 'c/src/lib/libbsp/no_cpu/no_bsp/shmsupp/lock.c')
-rw-r--r-- | c/src/lib/libbsp/no_cpu/no_bsp/shmsupp/lock.c | 86 |
1 files changed, 0 insertions, 86 deletions
diff --git a/c/src/lib/libbsp/no_cpu/no_bsp/shmsupp/lock.c b/c/src/lib/libbsp/no_cpu/no_bsp/shmsupp/lock.c deleted file mode 100644 index acdc8b7b48..0000000000 --- a/c/src/lib/libbsp/no_cpu/no_bsp/shmsupp/lock.c +++ /dev/null @@ -1,86 +0,0 @@ -/* Shared Memory Lock Routines - * - * This shared memory locked queue support routine need to be - * able to lock the specified locked queue. Interrupts are - * disabled while the queue is locked to prevent preemption - * and deadlock when two tasks poll for the same lock. - * previous level. - * - * COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994. - * On-Line Applications Research Corporation (OAR). - * All rights assigned to U.S. Government, 1994. - * - * This material may be reproduced by or for the U.S. Government pursuant - * to the copyright license under the clause at DFARS 252.227-7013. This - * notice must appear in all copies of this file and its derivatives. - * - * $Id$ - */ - -#include <rtems.h> -#include <bsp.h> -#include <shm.h> - -/* - * Shm_Initialize_lock - * - * Initialize the lock for the specified locked queue. - */ - -void Shm_Initialize_lock( - Shm_Locked_queue_Control *lq_cb -) -{ - lq_cb->lock = LQ_UNLOCKED; -} - -/* void _Shm_Lock( &lq_cb ) - * - * This shared memory locked queue support routine locks the - * specified locked queue. It disables interrupts to prevent - * a deadlock condition. - */ - -void Shm_Lock( - Shm_Locked_queue_Control *lq_cb -) -{ - rtems_unsigned32 isr_level; - rtems_unsigned32 *lockptr = &lq_cb->lock; - rtems_unsigned32 lock_value; - - lock_value = 0x80000000; - rtems_interrupt_disable( isr_level ); - - Shm_isrstat = isr_level; - while ( lock_value ) { - asm volatile( "" - : "=r" (lockptr), "=r" (lock_value) - : "0" (lockptr), "1" (lock_value) - ); - /* - * If not available, then may want to delay to reduce load on lock. - */ - - if ( lock_value ) - delay( 10 ); /* approximately 10 microseconds */ - } -} - -/* - * Shm_Unlock - * - * Unlock the lock for the specified locked queue. - */ - -void Shm_Unlock( - Shm_Locked_queue_Control *lq_cb -) -{ - rtems_unsigned32 isr_level; - - lq_cb->lock = SHM_UNLOCK_VALUE; - isr_level = Shm_isrstat; - rtems_interrupt_enable( isr_level ); -} - |