/* Shared Memory Lock Routines
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/* Shared Memory Lock Routines
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*
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*
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* This shared memory locked queue support routine need to be
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* This shared memory locked queue support routine need to be
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* able to lock the specified locked queue. Interrupts are
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* able to lock the specified locked queue. Interrupts are
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* disabled while the queue is locked to prevent preemption
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* disabled while the queue is locked to prevent preemption
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* and deadlock when two tasks poll for the same lock.
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* and deadlock when two tasks poll for the same lock.
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* previous level.
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* previous level.
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*
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*
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* COPYRIGHT (c) 1989-1997.
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* COPYRIGHT (c) 1989-1997.
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* On-Line Applications Research Corporation (OAR).
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* On-Line Applications Research Corporation (OAR).
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* Copyright assigned to U.S. Government, 1994.
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* Copyright assigned to U.S. Government, 1994.
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*
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*
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* The license and distribution terms for this file may in
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* The license and distribution terms for this file may in
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* the file LICENSE in this distribution or at
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* the file LICENSE in this distribution or at
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* http://www.OARcorp.com/rtems/license.html.
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* http://www.OARcorp.com/rtems/license.html.
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*
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*
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* $Id: lock.c,v 1.2 2001-09-27 12:01:02 chris Exp $
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* $Id: lock.c,v 1.2 2001-09-27 12:01:02 chris Exp $
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*/
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*/
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#include <rtems.h>
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#include <rtems.h>
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#include <bsp.h>
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#include <bsp.h>
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#include <shm_driver.h>
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#include <shm_driver.h>
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typedef volatile unsigned int volint;
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typedef volatile unsigned int volint;
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/*
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/*
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* Shm_Initialize_lock
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* Shm_Initialize_lock
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*
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*
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* Initialize the lock for the specified locked queue.
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* Initialize the lock for the specified locked queue.
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*/
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*/
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void Shm_Initialize_lock(
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void Shm_Initialize_lock(
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Shm_Locked_queue_Control *lq_cb
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Shm_Locked_queue_Control *lq_cb
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)
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)
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{
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{
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/* nothing required -- done implicitly by device tree */
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/* nothing required -- done implicitly by device tree */
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}
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}
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/* void _Shm_Lock( &lq_cb )
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/* void _Shm_Lock( &lq_cb )
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*
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*
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* This shared memory locked queue support routine locks the
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* This shared memory locked queue support routine locks the
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* specified locked queue. It disables interrupts to prevent
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* specified locked queue. It disables interrupts to prevent
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* a deadlock condition.
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* a deadlock condition.
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*/
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*/
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void Shm_Lock(
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void Shm_Lock(
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Shm_Locked_queue_Control *lq_cb
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Shm_Locked_queue_Control *lq_cb
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)
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)
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{
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{
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volint *p = (volint *)0xc0010000;
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volint *p = (volint *)0xc0010000;
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(void) p[1];
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(void) p[1];
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}
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}
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/*
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/*
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* Shm_Unlock
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* Shm_Unlock
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*
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*
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* Unlock the lock for the specified locked queue.
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* Unlock the lock for the specified locked queue.
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*/
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*/
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void Shm_Unlock(
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void Shm_Unlock(
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Shm_Locked_queue_Control *lq_cb
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Shm_Locked_queue_Control *lq_cb
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)
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)
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{
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{
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volint *p = (volint *)0xc0010000;
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volint *p = (volint *)0xc0010000;
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(void) p[2];
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(void) p[2];
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}
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}
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