view src/g23m-fad/t30/t30_bcss.c @ 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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/* 
+----------------------------------------------------------------------------- 
|  Project :  GSM-F&D (8411)
|  Modul   :  t30_bcss
+----------------------------------------------------------------------------- 
|  Copyright 2002 Texas Instruments Berlin, AG 
|                 All rights reserved. 
| 
|                 This file is confidential and a trade secret of Texas 
|                 Instruments Berlin, AG 
|                 The receipt of or possession of this file does not convey 
|                 any rights to reproduce or disclose its contents or to 
|                 manufacture, use, or sell anything it may describe, in 
|                 whole, or in part, without the specific written consent of 
|                 Texas Instruments Berlin, AG. 
+----------------------------------------------------------------------------- 
|  Purpose :  This Modul defines the functions for processing
|             of incomming signals for the component T30
|             of the mobile station
+----------------------------------------------------------------------------- 
*/ 

#ifndef T30_BCSS_C
#define T30_BCSS_C
#endif

#define ENTITY_T30

/*==== INCLUDES ===================================================*/

#include <string.h>
#include <stdlib.h>
#include <stddef.h>
#include "typedefs.h"
#include "pcm.h"
#include "vsi.h"
#include "macdef.h"
#include "pconst.cdg"
#include "mconst.cdg"
#include "message.h"
#include "ccdapi.h"
#include "custom.h"
#include "gsm.h"
#include "prim.h"
#include "cnf_t30.h"
#include "mon_t30.h"
#include "pei.h"
#include "tok.h"
#include "dti.h"      /* functionality of the dti library */
#include "t30.h"

/*==== CONST =======================================================*/

/*==== TYPES =======================================================*/

/*==== VAR EXPORT ==================================================*/

/*==== VAR LOCAL ===================================================*/

/*==== FUNCTIONS ===================================================*/

/*
+--------------------------------------------------------------------+
| PROJECT : GSM-F&D (8411)             MODULE  : T30_BCSF            |
| STATE   : code                       ROUTINE : bcs_encode          |
+--------------------------------------------------------------------+

  PURPOSE : This function encodes an HDLC frame.
*/

LOCAL UBYTE bcs_encode(void)
{
  SHORT ret;
  T_sdu *BCI_stream = (T_sdu*)t30_data->BCI_stream;

  BCI_stream->o_buf = 16;
  BCI_stream->l_buf = BIT_STREAM_LEN_BYT * 8;

  ret = ccd_codeMsg(CCDENT_T30, UPLINK, (T_MSGBUF*)BCI_stream, _decodedMsg, HDLC_ADDR);

  if (ret EQ ccdError)
  {
    TRACE_EVENT ("ERROR: ccd_encode") ;
  }

#ifdef _SIMULATION_ /* show contents of buffer */
  if (t30_data->test_mode & TST_BUF)
  {
    if (ret EQ ccdOK)
    {
      ker_debug("ccd_encode", &BCI_stream->buf[3], (USHORT)(BCI_stream->l_buf >> 3));
    }
  }
#endif

  return ((ret EQ ccdError) ? CCD_ERR : CCD_OK);
}

/*
+--------------------------------------------------------------------+
| PROJECT : GSM-F&D (8411)             MODULE  : T30_BCSS            |
| STATE   : code                       ROUTINE : sig_ker_bcs_bdat_req|
+--------------------------------------------------------------------+

  PURPOSE : Process signal BDAT_REQ received from process KER.
            The received bcs_data is encoded and collected.
*/

GLOBAL void sig_ker_bcs_bdat_req (UBYTE final)
{
  T_FAD_DATA_REQ *fad_data_req_fin;

  TRACE_FUNCTION ("sig_ker_bcs_bdat_req()");

  if (t30_data->fad_data_req EQ NULL)
  {
    PALLOC_SDU (fad_data_req, FAD_DATA_REQ, BCS_FRM_SIZE_BITS);
    memset (fad_data_req, 0, sizeof (T_FAD_DATA_REQ));
    t30_data->fad_data_req = fad_data_req;
    t30_data->stuff_bits = 8;
  }
  else
    bcs_bcs_encode(CTL_C0, FINAL_NO);

  switch (bcs_encode())
  {
  case CCD_OK:
    if (!final)
      return;

    bcs_bcs_encode (CTL_C8, FINAL_YES);
    fad_data_req_fin = t30_data->fad_data_req;
    t30_data->fad_data_req = NULL;
    fad_data_req_fin->final = TRUE;
    fad_data_req_fin->trans_rate = R_BCS;
    sig_bcs_mux_bcs_req(fad_data_req_fin);
    break;

  case CCD_ERR:
    PFREE (t30_data->fad_data_req);
    t30_data->fad_data_req = NULL;
    snd_error_ind(ERR_CCD_ENC);
    break;
  }
}

/*
+--------------------------------------------------------------------+
| PROJECT : GSM-F&D (8411)             MODULE  : T30_BCSS            |
| STATE   : code                       ROUTINE : sig_mux_bcs_bcs_ind |
+--------------------------------------------------------------------+

  PURPOSE : Process signal BCS_IND received from process MUX.
            The received bcs_data is collected, destuffed and
            decoded. The decoded data is sent to the kernel.
*/

GLOBAL void sig_mux_bcs_bcs_ind (T_FAD_DATA_IND *fad_data_ind)
{
  TRACE_FUNCTION ("sig_mux_bcs_bcs_ind()");

  switch (bcs_fill_bcs_frm(fad_data_ind))
  {
  case BCS_FRM_FILLING:
    return;

  case BCS_FRM_FILLED:
    bcs_bcs_decode();
    break;

  case BCS_FRM_FULL:
    sig_bcs_ker_err_ind(ERR_BUF_FULL);
    break;
  }

  memset (t30_data->bcs_frm, 0, BCS_FRM_SIZE);
}