FreeCalypso > hg > fc-tourmaline
view src/g23m-gsm/dl/dl_dcch0.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 |
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/* +----------------------------------------------------------------------------- | Project : GSM-PS | Modul : DL_DCCH0 +----------------------------------------------------------------------------- | 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 the stand alone | dedicated control channel (SDCCH) and the fast dedicated | control channel (FACCH) each with SAPI 0 of the component DL +----------------------------------------------------------------------------- */ #ifndef DL_DCCH0_C #define DL_DCCH0_C #define ENTITY_DL /*==== INCLUDES ===================================================*/ #include "typedefs.h" #include "string.h" #include "vsi.h" #include "pconst.cdg" #include "custom.h" #include "gsm.h" #include "mon_dl.h" #include "prim.h" #include "pei.h" #include "tok.h" #include "ccdapi.h" #include "dl.h" #include "dl_trc.h" /*==== EXPORT =====================================================*/ /*==== PRIVAT =====================================================*/ LOCAL void dcch0_resume_reconnect_req (T_PRIM * prim, U8 ch_type); /*==== VARIABLES ==================================================*/ /*==== FUNCTIONS ==================================================*/ /* +--------------------------------------------------------------------+ | PROJECT : GSM-PS (6147) MODULE : DL_SDCCH | | STATE : code ROUTINE : sdcch0_init_dl_data | +--------------------------------------------------------------------+ PURPOSE : Initialisation of DCCH data (SAPI 0) for an instance. */ GLOBAL void dcch0_init_dl_data (void) { GET_INSTANCE_DATA; T_CCH *pcch = &dl_data->cch[C_DCCH0]; TRACE_FUNCTION ("dcch0_init_dl_data()"); memset (pcch, 0, sizeof (T_CCH)); dcch3_init_dl_data (); /*Disabling SAPI 3 connections */ com_clear_queue (PS_SAPI_0); dl_data->rr_short_pd_buffer.l_buf = 0; if (dl_data->dcch0_in_msg) { COM_FREE_POINTER (dl_data->dcch0_in_msg); dl_data->dcch0_in_msg = NULL; } dl_data->RR_dedicated = FALSE; dl_data->dcch0_ch_type = 0; dl_data->dcch0_disc_request = FALSE; #if defined(DELAYED_SABM) dl_data->dcch0_sabm_delay = 0; dl_data->dcch0_sabm_flag = NOT_PRESENT_8BIT; #endif /* DELAYED_SABM */ #if defined(DELAYED_RELEASE_IND) dl_data->release_ind_delay = 0; dl_data->release_ind_ch_type = NOT_PRESENT_8BIT; #endif /* DELAYED_RELEASE_IND */ set_channel_state(C_DCCH0, STATE_IDLE_DL); sacch0_init_dl_data (); } #if defined(DELAYED_SABM) GLOBAL void dcch0_delay_sabm (T_CCH *pcch) { GET_INSTANCE_DATA; BOOL send_sabm = FALSE; if (dl_data->dcch0_sabm_flag EQ NOT_PRESENT_8BIT) { if ((pcch->ch_type EQ L2_CHANNEL_FACCH_F) OR (pcch->ch_type EQ L2_CHANNEL_FACCH_H)) { /* start delay */ pcch->vtx = EMPTY_CMD; /* send dummy only */ dl_data->dcch0_sabm_flag = SABM_CMD; dl_data->dcch0_sabm_delay = DL_FACCH_SABM_DELAY_VALUE; DL_OFFLINE_TRACE (TRACE_DL_EVENT, C_DCCH0, pcch->ch_type, "delay SABM on FACCH"); } else { /* but for FACCH only */ send_sabm = TRUE; } } else /* this part is called also called during uplink opportunity */ { /* pending delay */ if (dl_data->dcch0_sabm_delay > 0) { dl_data->dcch0_sabm_delay--; DL_OFFLINE_TRACE (TRACE_DL_EVENT, C_DCCH0, pcch->ch_type, "pending delayed SABM"); } else {/* finishing delay, send SABM with the current (next) uplink opportunity */ #if !defined(DL_TRACE_ENABLED) TRACE_EVENT ("delayed SABM"); #endif /* ! DL_TRACE_ENABLED*/ dl_data->dcch0_sabm_flag = NOT_PRESENT_8BIT; send_sabm = TRUE; DL_OFFLINE_TRACE (TRACE_DL_EVENT, C_DCCH0, pcch->ch_type, "send delayed SABM"); } } if (send_sabm) { pcch->vtx = SABM_CMD; pcch->time_flag = TRUE; pcch->rc = 0; set_channel_state (C_DCCH0, STATE_CONTENTION_RESOLUTION); } } #endif /* DELAYED_SABM */ /* +--------------------------------------------------------------------+ | PROJECT : GSM-PS (6147) MODULE : DL_SDCCH | | STATE : code ROUTINE : sdcch0_establish_req | +--------------------------------------------------------------------+ PURPOSE : Establish Request for SDCCH SAPI 0. */ GLOBAL void dcch0_establish_req (T_DL_ESTABLISH_REQ * est_req) { GET_INSTANCE_DATA; T_CCH *pcch = &dl_data->cch[C_DCCH0]; TRACE_FUNCTION ("sdcch0_establish_req()"); DL_OFFLINE_TRACE (TRACE_DL_EVENT, C_DCCH0, est_req->ch_type, "est req"); dl_data->dcch0_ch_type = pcch->ch_type = est_req->ch_type; TRACE_EVENT_WIN_P1 ("set dcch0_ch_type=%s", CH_TYPE_NAME[dl_data->dcch0_ch_type]); dl_data->dcch0_unserved = com_queue_awaiting_transmission (PS_SAPI_0) ? DL_UNSERVED : DL_ALL_DONE; switch (dl_data->state[C_DCCH0]) { case STATE_IDLE_DL: /* * initialize sacch buffer */ dl_data->sacch_act_buffer = meas_report_no_nc; dl_data->sacch_last_buffer= meas_report_no_nc; com_clear_queue (PS_SAPI_0); pcch->contention_resolution = TRUE; dl_data->dcch0_queue.switch_buffer = (T_DL_DATA_REQ*)est_req; dl_data->dcch0_disc_request = FALSE; #if defined(DELAYED_SABM) dcch0_delay_sabm(pcch); #else /* DELAYED_SABM */ pcch->vtx = SABM_CMD; pcch->time_flag = TRUE; pcch->rc = 0; set_channel_state (C_DCCH0, STATE_CONTENTION_RESOLUTION); #endif /* DELAYED_SABM */ TRACE_EVENT_WIN_P5 ("EST_REQ: %s SAPI=%u vtx=%s (%s#%u)", CH_TYPE_NAME[pcch->ch_type], est_req->sapi, VTX_NAME[pcch->vtx], __FILE10__, __LINE__); #if defined(DELAYED_SABM) dcch0_delay_sabm(pcch); #endif /* DELAYED_SABM */ break; case STATE_MULTIPLE_FRAME_ESTABLISHED: case STATE_TIMER_RECOVERY: if (est_req->sdu.l_buf EQ 0) { dcch3_init_dl_data (); /*Disabling SAPI 3 connections */ com_clear_queue (PS_SAPI_0); pcch->T200_counter = 0; pcch->contention_resolution = FALSE; pcch->vtx = SABM_CMD; pcch->time_flag = TRUE; pcch->rc = 0; set_channel_state (C_DCCH0, STATE_CONTENTION_RESOLUTION); TRACE_EVENT_WIN_P5 ("EST_REQ: %s SAPI=%u vtx=%s (%s#%u)", CH_TYPE_NAME[pcch->ch_type], est_req->sapi, VTX_NAME[pcch->vtx], __FILE10__, __LINE__); } else { dcch0_mdl_release_req (); } COM_FREE_POINTER (est_req); break; default: COM_FREE_POINTER (est_req); dcch0_mdl_release_req (); break; } } /* +--------------------------------------------------------------------+ | PROJECT : GSM-PS (6147) MODULE : DL_SDCCH | | STATE : code ROUTINE : sdcch0_resume_req | +--------------------------------------------------------------------+ PURPOSE : Resume Request for SDCCH (SAPI 0). */ GLOBAL void dcch0_resume_req (T_DL_RESUME_REQ * resume_req) { TRACE_FUNCTION ("dcch0_resume_req()"); DL_OFFLINE_TRACE (TRACE_DL_EVENT, C_DCCH0, resume_req->ch_type, "resume req"); dcch0_resume_reconnect_req( (T_PRIM *)D2P(resume_req), resume_req->ch_type); } /* +--------------------------------------------------------------------+ | PROJECT : GSM-PS (6147) MODULE : DL_SDCCH | | STATE : code ROUTINE : sdcch0_reconnect_req | +--------------------------------------------------------------------+ PURPOSE : Reconnect Request for SDCCH (SAPI 0). */ GLOBAL void dcch0_reconnect_req (T_DL_RECONNECT_REQ * reconnect_req) { TRACE_FUNCTION ("dcch0_reconnect_req()"); DL_OFFLINE_TRACE (TRACE_DL_EVENT, C_DCCH0, reconnect_req->ch_type, "reconn req"); dcch0_resume_reconnect_req( (T_PRIM *)D2P (reconnect_req),reconnect_req->ch_type); } /* +--------------------------------------------------------------------+ | PROJECT : GSM-PS (6147) MODULE : DL_SDCCH | | STATE : code ROUTINE : dcch0_res_recon_req | +--------------------------------------------------------------------+ PURPOSE : This function processes Resume Request and Reconnect Request for SDCCH (SAPI 0). */ LOCAL void dcch0_resume_reconnect_req (T_PRIM * prim, U8 ch_type) { GET_INSTANCE_DATA; TRACE_FUNCTION ("dcch0_resume_reconnect_req()"); switch (dl_data->state[C_DCCH0]) { case STATE_SUSPENDED: case STATE_IDLE_DL: { T_CCH *pcch = &dl_data->cch[C_DCCH0]; dl_data->dcch0_ch_type = pcch->ch_type = ch_type; TRACE_EVENT_WIN_P1 ("set dcch0_ch_type=%s", CH_TYPE_NAME[dl_data->dcch0_ch_type]); com_restore_queue(PS_SAPI_0, (T_DL_DATA_REQ*)P2D(prim)); pcch->contention_resolution = FALSE; #if defined(DELAYED_SABM) dcch0_delay_sabm(dl_data, pcch); #else /* DELAYED_SABM */ pcch->vtx = SABM_CMD; pcch->time_flag = TRUE; pcch->rc = 0; set_channel_state (C_DCCH0, STATE_CONTENTION_RESOLUTION); #endif /* DELAYED_SABM */ if(prim->custom.opc EQ DL_RECONNECT_REQ) { TRACE_EVENT_WIN_P5 ("RECONN_REQ: %s SAPI=%u vtx=%s (%s#%u)", CH_TYPE_NAME[pcch->ch_type], PS_SAPI_0, VTX_NAME[pcch->vtx], __FILE10__, __LINE__); } else { TRACE_EVENT_WIN_P5 ("RESUME_REQ: %s SAPI=%u vtx=%s (%s#%u)", CH_TYPE_NAME[pcch->ch_type], PS_SAPI_0, VTX_NAME[pcch->vtx], __FILE10__, __LINE__); /* invalid measurement report first */ sacch0_reset_meas (); } break; } default: { COM_FREE_POINTER (P2D(prim)); } break; }/* endswitch */ } /* +--------------------------------------------------------------------+ | PROJECT : GSM-PS (6147) MODULE : DL_SDCCH | | STATE : code ROUTINE : sdcch0_release_req | +--------------------------------------------------------------------+ PURPOSE : Release Request for SDCCH (SAPI 0). */ GLOBAL BOOL dcch0_release_req (T_DL_RELEASE_REQ * release_req) { GET_INSTANCE_DATA; BOOL bFree = TRUE; TRACE_FUNCTION ("dcch0_release_req()"); if (release_req->mode EQ DL_LOCAL_END_RELEASE) { DL_OFFLINE_TRACE (TRACE_DL_EVENT, C_DCCH0, release_req->ch_type, "local end release req"); dcch0_init_dl_data (); bFree = FALSE; } else { DL_OFFLINE_TRACE (TRACE_DL_EVENT, C_DCCH0, release_req->ch_type, "normal release req"); dl_data->cch[C_DCCH0].ch_type = release_req->ch_type; switch (dl_data->state[C_DCCH0]) { default: bFree = FALSE; break; case STATE_CONTENTION_RESOLUTION: case STATE_MULTIPLE_FRAME_ESTABLISHED: case STATE_TIMER_RECOVERY: if (!dl_data->dcch0_disc_request AND (dl_data->cch[C_DCCH0].vtx EQ RR_CMD)) { dl_data->dcch0_disc_request = TRUE; dcch3_init_dl_data (); /*Disabling SAPI 3 connections */ } else { dcch3_init_dl_data (); /*Disabling SAPI 3 connections */ com_prepare_DISC (C_DCCH0, release_req->sapi); } break; case STATE_AWAITING_RELEASE: dl_data->cch[C_DCCH0].T200_counter = 0; break; } } if (bFree EQ FALSE) { PREUSE (release_req, release_cnf, DL_RELEASE_CNF); release_cnf->indication = com_queue_awaiting_transmission (PS_SAPI_0) ? DL_UNSERVED : DL_ALL_DONE; PSENDX (RR, release_cnf); dcch0_init_dl_data (); } return bFree; } /* +--------------------------------------------------------------------+ | PROJECT : GSM-PS (6147) MODULE : DL_SDCCH | | STATE : code ROUTINE : sdcch0_mdl_release_req | +--------------------------------------------------------------------+ PURPOSE : Release Request from Mobility Management for SDCCH (SAPI 0). */ GLOBAL void dcch0_mdl_release_req (void) { GET_INSTANCE_DATA; TRACE_FUNCTION ("dcch0_mdl_release_req()"); DL_OFFLINE_TRACE (TRACE_DL_EVENT, C_DCCH0, dl_data->cch[C_DCCH0].ch_type, "mdl rel req"); switch (dl_data->state[C_DCCH0]) { case STATE_CONTENTION_RESOLUTION: case STATE_AWAITING_RELEASE: drr_dl_release_cnf (dl_data->cch[C_DCCH0].ch_type, PS_SAPI_0, TRUE); break; case STATE_MULTIPLE_FRAME_ESTABLISHED: case STATE_TIMER_RECOVERY: drr_dl_release_ind (dl_data->cch[C_DCCH0].ch_type, PS_SAPI_0, NOT_PRESENT_8BIT, TRUE); break; default: break; } } /* +--------------------------------------------------------------------+ | PROJECT : GSM-PS (6147) MODULE : DL_SDCCH | | STATE : code ROUTINE : sdcch0_suspend_req | +--------------------------------------------------------------------+ PURPOSE : Suspend Request for SDCCH (SAPI 0). */ GLOBAL void dcch0_suspend_req (T_DL_SUSPEND_REQ * suspend_req) { GET_INSTANCE_DATA; T_CCH *pcch = &dl_data->cch[C_DCCH0]; TRACE_FUNCTION ("dcch0_suspend_req()"); DL_OFFLINE_TRACE (TRACE_DL_EVENT, C_DCCH0, suspend_req->ch_type, "suspend req"); pcch->ch_type = suspend_req->ch_type; TRACE_EVENT_WIN_P1 ("reset dcch0_ch_type=%s ->0", CH_TYPE_NAME[dl_data->dcch0_ch_type]); dl_data->dcch0_ch_type = 0; switch (dl_data->state[C_DCCH0]) { case STATE_CONTENTION_RESOLUTION: case STATE_MULTIPLE_FRAME_ESTABLISHED: case STATE_TIMER_RECOVERY: case STATE_AWAITING_RELEASE: pcch->T200_counter = 0; pcch->time_flag = FALSE; pcch->contention_resolution = FALSE; set_channel_state (C_DCCH0, STATE_SUSPENDED); dcch3_init_dl_data (); /* Disabling SAPI 3 connections */ #if 0 /* yes, from now DL sends measurement reports also in suspended state */ /* * no further measurement reports */ sacch0_reset_meas (dl_data); #endif /* 0|1 */ break; default: TRACE_EVENT ("INVALID SUSPEND STATE"); break; } COM_FREE_POINTER (suspend_req); TRACE_EVENT_WIN_P5 ("SUSPEND_REQ: %s SAPI=%u vtx=%s (%s#%u)", CH_TYPE_NAME[pcch->ch_type], PS_SAPI_0, VTX_NAME[pcch->vtx], __FILE10__, __LINE__); } /* +--------------------------------------------------------------------+ | PROJECT : GSM-PS (6147) MODULE : DL_SDCCH | | STATE : code ROUTINE : dcch0_check_disc | +--------------------------------------------------------------------+ PURPOSE : DISC command frame on DCCH0. */ GLOBAL int dcch0_check_disc (int send) { GET_INSTANCE_DATA; TRACE_FUNCTION ("dcch0_check_disc()"); if (dl_data->dcch0_disc_request AND !(dl_data->cch[C_DCCH0].vtx EQ RR_CMD)) { dcch3_init_dl_data (); /*Disabling SAPI 3 connections */ com_prepare_DISC (C_DCCH0, PS_SAPI_0); dl_data->dcch0_disc_request = FALSE; #if defined(DELAYED_SABM) dl_data->dcch0_sabm_flag = NOT_PRESENT_8BIT; /* delete pending delayed SABM */ #endif /* DELAYED_SABM */ return uplink_awaiting_release (C_DCCH0, PS_SAPI_0); } else return send; } /* +--------------------------------------------------------------------+ | PROJECT : GSM-PS (6147) MODULE : DL_SDCCH | | STATE : code ROUTINE : dcch0_data_req | +--------------------------------------------------------------------+ PURPOSE : Data Request on SDCCH (SAPI 0). */ GLOBAL void dcch0_data_req (T_DL_DATA_REQ * data_req) { GET_INSTANCE_DATA; TRACE_FUNCTION ("sdcch0_data_req()"); dl_data->cch[C_DCCH0].ch_type = data_req->ch_type; switch (dl_data->state[C_DCCH0]) { case STATE_MULTIPLE_FRAME_ESTABLISHED: case STATE_TIMER_RECOVERY: case STATE_SUSPENDED: case STATE_CONTENTION_RESOLUTION: com_store_queue (PS_SAPI_0, data_req); break; default: COM_FREE_POINTER (data_req); break; } } #endif /* !DL_DCCH0_C */