diff options
Diffstat (limited to 'c/src/lib/libbsp/a29k/portsw/shmsupp/lock.c')
-rw-r--r-- | c/src/lib/libbsp/a29k/portsw/shmsupp/lock.c | 89 |
1 files changed, 0 insertions, 89 deletions
diff --git a/c/src/lib/libbsp/a29k/portsw/shmsupp/lock.c b/c/src/lib/libbsp/a29k/portsw/shmsupp/lock.c deleted file mode 100644 index 3a99179e57..0000000000 --- a/c/src/lib/libbsp/a29k/portsw/shmsupp/lock.c +++ /dev/null @@ -1,89 +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) 1989-1999. - * On-Line Applications Research Corporation (OAR). - * - * The license and distribution terms for this file may be - * found in the file LICENSE in this distribution or at - * http://www.OARcorp.com/rtems/license.html. - * - * $Id$ - */ - -#include <rtems.h> -#include <bsp.h> -#include <shm_driver.h> - -#ifndef lint -static char _sccsid[] = "@(#)lock.c 04/08/96 1.1\n"; -#endif - -/* - * 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 ); -} - |