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view src/cs/os/nucleus/cs_defs.h @ 220:0ed36de51973

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ABB semaphore protection overhaul The ABB semaphone protection logic that came with TCS211 from TI was broken in several ways: * Some semaphore-protected functions were called from Application_Initialize() context. NU_Obtain_Semaphore() called with NU_SUSPEND fails with NU_INVALID_SUSPEND in this context, but the return value wasn't checked, and NU_Release_Semaphore() would be called unconditionally at the end. The latter call would increment the semaphore count past 1, making the semaphore no longer binary and thus no longer effective for resource protection. The fix is to check the return value from NU_Obtain_Semaphore() and skip the NU_Release_Semaphore() call if the semaphore wasn't properly obtained. * Some SPI hardware manipulation was being done before entering the semaphore- protected critical section. The fix is to reorder the code: first obtain the semaphore, then do everything else. * In the corner case of L1/DSP recovery, l1_abb_power_on() would call some non-semaphore-protected ABB & SPI init functions. The fix is to skip those calls in the case of recovery. * A few additional corner cases existed, all of which are fixed by making ABB semaphore protection 100% consistent for all ABB functions and code paths. There is still one remaining problem of priority inversion: suppose a low- priority task calls an ABB function, and some medium-priority task just happens to preempt right in the middle of that semaphore-protected ABB operation. Then the high-priority SPI task is locked out for a non-deterministic time until that medium-priority task finishes its work and goes back to sleep. This priority inversion problem remains outstanding for now.
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 26 Apr 2021 20:55:25 +0000
parents 4e78acac3d88
children
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/*************************************************************************/
/*                                                                       */
/*        Copyright (c) 1993-1994 Accelerated Technology, Inc.           */
/*                                                                       */
/* PROPRIETARY RIGHTS of Accelerated Technology are involved in the      */
/* subject matter of this material.  All manufacturing, reproduction,    */
/* use, and sales rights pertaining to this subject matter are governed  */
/* by the license agreement.  The recipient of this software implicitly  */
/* accepts the terms of the license.                                     */
/*                                                                       */
/*************************************************************************/

/*************************************************************************/
/*                                                                       */
/* FILE NAME                                            VERSION          */
/*                                                                       */
/*      cs_defs.h                                       PLUS  1.1        */
/*                                                                       */
/* COMPONENT                                                             */
/*                                                                       */
/*      CS -    Common Services                                          */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This file contains data structure definitions used in the common */
/*      service linked list routines.                                    */
/*                                                                       */
/* AUTHOR                                                                */
/*                                                                       */
/*      William E. Lamie, Accelerated Technology, Inc.                   */
/*                                                                       */
/* DATA STRUCTURES                                                       */
/*                                                                       */
/*      CS_NODE                             Link node structure          */
/*                                                                       */
/* FUNCTIONS                                                             */
/*                                                                       */
/*      None                                                             */
/*                                                                       */
/* DEPENDENCIES                                                          */
/*                                                                       */
/*      nucleus.h                           Nucleus PLUS constants       */
/*                                                                       */
/* HISTORY                                                               */
/*                                                                       */
/*         NAME            DATE                    REMARKS               */
/*                                                                       */
/*      W. Lamie        03-01-1993      Created initial version 1.0      */
/*      D. Lamie        04-19-1993      Verified version 1.0             */
/*      W. Lamie        06-01-1993      Added padding conditional into   */
/*                                        CS_NODE structure, making      */
/*                                        version 1.0a                   */
/*      D. Lamie        06-01-1993      Verified version 1.0a            */
/*      W. Lamie        03-01-1994      Moved include files outside of   */
/*                                        the file #ifndef to allow the  */
/*                                        use of actual data structures, */
/*                                        resulting in version 1.1       */
/*      R. Pfaff -                                                       */
/*      D. Lamie        03-18-1994      Verified version 1.1             */
/*                                                                       */
/*************************************************************************/

#include        "nucleus.h"                 /* Include Nucleus constants */


/* Check to see if the file has been included already.  */
#ifndef CS_DEFS
#define CS_DEFS


/* Define a common node data structure that can be included inside of
   other system data structures.  */

typedef struct  CS_NODE_STRUCT
{
    struct CS_NODE_STRUCT  *cs_previous;
    struct CS_NODE_STRUCT  *cs_next;
    DATA_ELEMENT            cs_priority;

#if     PAD_1
    DATA_ELEMENT            cs_padding[PAD_1];
#endif

}  CS_NODE;

#endif