view src/g23m-gprs/sndcp/sndcp_suaf.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
line source

/* 
+----------------------------------------------------------------------------- 
|  Project :  GPRS (8441)
|  Modul   :  sndcp_suaf.c
+----------------------------------------------------------------------------- 
|  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 is part of the entity SNDCP and implements all 
|             procedures and functions as described in the 
|             SDL-documentation (SUA-statemachine)
+----------------------------------------------------------------------------- 
*/ 

 
#define ENTITY_SNDCP

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

#include "typedefs.h"    /* to get Condat data types */
#include "vsi.h"        /* to get a lot of macros */
#include "macdef.h"
#include "prim.h"       /* to get the definitions of used SAP and directions */

#include "dti.h"

#include "sndcp.h"        /* to get the global entity definitions */
#include "sndcp_f.h"       /* to get the functions to access the global arrays*/

#include "sndcp_suaf.h"  /* to get this file  */
#include "sndcp_nus.h"  /* to get signals to service nu  */
#include "sndcp_cias.h"  /* to get signals to service cia  */


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

/*==== LOCAL VARS ===========================================================*/

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

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

#ifdef _SNDCP_DTI_2_
/*
+------------------------------------------------------------------------------
| Function    : sua_get_nsapi
+------------------------------------------------------------------------------
| Description : find the affected nsapi in sn-PDU.
|
| Parameters  : ll_desc_req*
| Returns     : the nsapi
|
+------------------------------------------------------------------------------
*/
GLOBAL U8 sua_get_nsapi (T_LL_DESC_REQ* ll_desc_req) 
{ 
   T_desc3* desc3 = NULL;
   U8 * sndcp_header = NULL;

  /* Get the descriptor describing the memory area with the sndcp header */

  desc3 = (T_desc3*)ll_desc_req->desc_list3.first;
  sndcp_header = (U8*)desc3->buffer;

  TRACE_FUNCTION( "sua_get_nsapi" );

  return (*(sndcp_header + ENCODE_OFFSET_BYTE)) & 0xf;
} /* sua_get_nsapi() */
#else /* _SNDCP_DTI_2_ */
/*
+------------------------------------------------------------------------------
| Function    : sua_get_nsapi
+------------------------------------------------------------------------------
| Description : find the affected nsapi in sn-PDU.
|
| Parameters  : ll_data_req*
| Returns     : the nsapi
|
+------------------------------------------------------------------------------
*/
GLOBAL UBYTE sua_get_nsapi (T_LL_DATA_REQ* ll_data_req) 
{ 
  USHORT octet_offset = (ll_data_req->sdu.o_buf) >> 3;

  TRACE_FUNCTION( "sua_get_nsapi" );

  return ll_data_req->sdu.buf[octet_offset] & 0xf;

} /* sua_get_nsapi() */
#endif /* _SNDCP_DTI_2_ */
/*
+------------------------------------------------------------------------------
| Function    : sua_init
+------------------------------------------------------------------------------
| Description : The function sua_init()
|
| Parameters  : 
|
+------------------------------------------------------------------------------
*/
GLOBAL void sua_init (void)
{ 
  TRACE_FUNCTION( "sua_init" );

  /*
   * Not initialized:
   * Members of sn_data_q are not set to NULL.
   * Members of npdu_number_q are not set to 0.
   * Members of ll_desc_q are not set to NULL.
   * Members of ll_data_q are not set to NULL.
   */

  sndcp_data->sua = & sndcp_data->sua_base[0];
  INIT_STATE(SUA_0, SUA_LLC_NOT_RECEPTIVE);
#ifdef SNDCP_2to1
  sndcp_data->sua->sapi = PS_SAPI_3; 
#else
  sndcp_data->sua->sapi = LL_SAPI_3; 
#endif /*SNDCP_2to1*/
  sndcp_data->sua = & sndcp_data->sua_base[1];
  INIT_STATE(SUA_1, SUA_LLC_NOT_RECEPTIVE);
#ifdef SNDCP_2to1
  sndcp_data->sua->sapi = PS_SAPI_5; 
#else
  sndcp_data->sua->sapi = LL_SAPI_5; 
#endif /*SNDCP_2to1*/

  sndcp_data->sua = & sndcp_data->sua_base[2];
  INIT_STATE(SUA_2, SUA_LLC_NOT_RECEPTIVE);
#ifdef SNDCP_2to1
  sndcp_data->sua->sapi = PS_SAPI_9; 
#else
  sndcp_data->sua->sapi = LL_SAPI_9; 
#endif /*SNDCP_2to1*/

  sndcp_data->sua = & sndcp_data->sua_base[3];
  INIT_STATE(SUA_3, SUA_LLC_NOT_RECEPTIVE);
#ifdef SNDCP_2to1
  sndcp_data->sua->sapi = PS_SAPI_11; 
#else
  sndcp_data->sua->sapi = LL_SAPI_11; 
#endif /*SNDCP_2to1*/
  {
    UBYTE sapi_index = 0;

    for (sapi_index = 0; sapi_index < SNDCP_NUMBER_OF_SAPIS; sapi_index++) {
      sndcp_data->sua = & sndcp_data->sua_base[sapi_index];
      sndcp_data->sua->n201_i = N201_I_DEFAULT;
      sndcp_data->sua->sn_data_q_read = 0;
      sndcp_data->sua->sn_data_q_write = 0;
#ifdef _SNDCP_DTI_2_
      sndcp_data->sua->ll_desc_q_read = 0;
      sndcp_data->sua->ll_desc_q_write = 0;
#else /* _SNDCP_DTI_2_ */
      sndcp_data->sua->ll_data_q_read = 0;
      sndcp_data->sua->ll_data_q_write = 0;
#endif /* _SNDCP_DTI_2_ */
      sndcp_data->sua->first_seg_info = NULL;
      sndcp_data->sua->cia_state = CIA_IDLE;

    }
  }

} /* sua_init() */

 


/*
+------------------------------------------------------------------------------
| Function    : sua_mark_segment
+------------------------------------------------------------------------------
| Description : The function sua_mark_segment()
|
| Parameters  : N-PDU number, NSAPI, LL_DESC_REQ in which the reference has to be set.
| Pre         : The "correct" sua instance is activated and 
|               sndcp_data->sua->segment_number is the segment number of the
|               current segment.
|
+------------------------------------------------------------------------------
*/
GLOBAL void sua_mark_segment (UBYTE npdu_number,
                              UBYTE nsapi)
{ 
  T_SEG_INFO* seg_info = NULL;

  TRACE_FUNCTION( "sua_mark_segment" );

  /*
   * Add new seg_info to the list.
   */
  if (sndcp_data->sua->first_seg_info == NULL) {
    MALLOC(seg_info, sizeof(T_SEG_INFO));
    /*
     * The list has been empty.
     */
    sndcp_data->sua->first_seg_info = seg_info;
    /*
     * First segment.
     */
    seg_info->number_of_segments = 1;
    /*
     * Reset the confirm mask.
     */
    seg_info->cnf_segments = 0;
    seg_info->npdu_number = npdu_number;
    seg_info->next = NULL;
    seg_info->nsapi = nsapi;
  } else {
    /*
     * There are already some seg_infos. Find the seg_info for the given N-PDU.
     * number and NSAPI or create a new one.
     */
    /*
     * Are N-PDU number and NSAPI different?
     */
    BOOL different = TRUE;
    BOOL end = FALSE;
    T_SEG_INFO* help = sndcp_data->sua->first_seg_info;

    while(!end && different) {
      if (nsapi == help->nsapi && npdu_number == help->npdu_number) {
        different = FALSE;
      } else {
        if (help->next == NULL) {
          end = TRUE;
        } else {
          help = help->next;
        }
      }
    }
    if (different) {
      /*
       * A seg_info with same NSAPI and N-PDU number has not been found.
       * Create a new one.
       */
      MALLOC(seg_info, sizeof(T_SEG_INFO));
      /*
       * First segment.
       */
      seg_info->number_of_segments = 1;
      /*
       * Reset the confirm mask.
       */
      seg_info->cnf_segments = 0;
      seg_info->npdu_number = npdu_number;
      seg_info->next = NULL;
      seg_info->nsapi = nsapi;
      /*
       * Add the new seg_info to the list.
       */
      help->next = seg_info;
    } else {
      /*
       * A seg_info with same NSAPI and N-PDU number has been found.
       * Use this one.
       */
      help->number_of_segments++;
    }

  }
 
} /* sua_mark_segment() */


/*
+------------------------------------------------------------------------------
| Function    : sua_next_sn_data_req
+------------------------------------------------------------------------------
| Description : If queue with sn_data_req is
| not empty, send SIG_SUA_CIA_DATA_REQ with next prim from sn_data_req queue
|
| Parameters  : sapi
| Pre         : cia_state == CIA_IDLE
|
+------------------------------------------------------------------------------
*/
GLOBAL void sua_next_sn_data_req (UBYTE sapi) 
{ 
  TRACE_FUNCTION( "sua_next_sn_data_req" );

  if (sndcp_data->sua->sn_data_q_write !=
      sndcp_data->sua->sn_data_q_read) {
    /*
     * Get sn_data_req from queue.
     */
    T_SN_DATA_REQ* sn_data_req = 
      sndcp_data->sua->sn_data_q[sndcp_data->sua->sn_data_q_read];
    /*
     * Get npdu_number from queue.
     */
    UBYTE npdu_num = 
      sndcp_data->sua->npdu_number_q[sndcp_data->sua->sn_data_q_read];
    UBYTE nsapi = sn_data_req->nsapi;

    sndcp_data->sua->sn_data_q[sndcp_data->sua->sn_data_q_read] = NULL;
    sndcp_data->sua->sn_data_q_read = 
      (sndcp_data->sua->sn_data_q_read + 1) % SN_DATA_Q_LEN;

    /*
     * Cia is now busy. Send data.
     */
    sndcp_data->sua->cia_state = CIA_BUSY;
    sig_sua_cia_cia_comp_req(sn_data_req,
                         npdu_num,
                         nsapi,
                         sapi);
  } else if (sndcp_data->sua->cia_state == CIA_IDLE) {
    UBYTE nsapi = 0;

    for (nsapi = 0; nsapi < SNDCP_NUMBER_OF_NSAPIS; nsapi++) {
      UBYTE used_sapi = 0;
      BOOL used = FALSE;
      BOOL ack = FALSE;

      sndcp_is_nsapi_used(nsapi, &used);
      if (used) {
        sndcp_get_nsapi_sapi(nsapi, &used_sapi);
        sndcp_get_nsapi_ack(nsapi, &ack);
        if (used_sapi == sapi && ack) {
          sig_sua_nu_ready_ind(nsapi);
        }
      }
    }
  }

} /* sua_next_sn_data_req() */