view src/g23m-fad/tcpip/include/general.h @ 220:0ed36de51973

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 fa8dc04885d8
children
line wrap: on
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/****************************************************************************/
/*                                                                          */
/*  Name        general.h                                                   */
/*                                                                          */
/*  Function    this file contains common data type definitions used        */
/*              throughout the SWE                                          */
/*                                                                          */
/*  Date       Modification                                                 */
/*  -----------------------                                                 */
/*  3/12/99    Create                                                       */
/* **************************************************************************/
/*  10/27/1999 David Lamy-Charrier: remove declaration of ntohs, htons,     */
/*                                  ntohl, htonl in order to avoid conflict */
/*                                  with winsock.h                          */
/*                                                                          */
/*  11/30/1999 Pascal Pompei: 'string.h' included in order to define memcmp,*/
/*                            memset and memcpy functions.                  */
/*                                                                          */
/*                                                                          */
/****************************************************************************/

#ifndef GENERAL_H
#define GENERAL_H

#ifdef _WINDOWS
   #include <string.h>
#endif

/* WINDOWS */
#ifdef _WINDOWS
   typedef unsigned short UINT16;
   typedef unsigned int UINT32;
   typedef unsigned char UBYTE;
   typedef short SHORT;
   typedef int BOOL;

/* BOARD */
#else
   #ifndef __TYPEDEFS_H__ /* This #define allows to Condat to use general.h without conflict */
      typedef unsigned short UINT16;
      typedef unsigned char UBYTE;
      typedef short SHORT;
      typedef signed char BYTE;
      #if !defined (BOOL_FLAG)
         #define BOOL_FLAG
         typedef unsigned char BOOL;
      #endif
      typedef unsigned short USHORT;
      typedef unsigned int ULONG;
   #endif
   typedef unsigned long UINT32;
#endif

typedef unsigned char UINT8;
typedef signed char INT8;
typedef short INT16;
typedef int INT32;
typedef unsigned char BOOLEAN;

typedef void (*FUNC)(void); /* pointer to a function */

#define OK 1

#ifndef NULL
   #define NULL 0
#endif

#ifndef TRUE
   #define TRUE 1
#endif

#ifndef FALSE
   #define FALSE 0
#endif

#define htons ntohs
#define htonl ntohl

#if !defined(_WIN32)
   #define ntohs(n) (n)
   #define ntohl(n) (n)
   #define ntoh6(n) (n)
#endif

#endif /* #ifndef GENERAL_H */