FreeCalypso > hg > fc-tourmaline
view src/g23m-fad/l2r/l2r_upp.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 : CSD (8411) | Modul : L2r_upp.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 defines the functions for processing | of incomming primitives for the component | L2R of the base station +----------------------------------------------------------------------------- */ #ifndef L2R_UPP_C #define L2R_UPP_C #endif #define ENTITY_L2R /*==== INCLUDES ===================================================*/ #include <string.h> #include "typedefs.h" #include "pconst.cdg" #include "vsi.h" #include "macdef.h" #include "custom.h" #include "gsm.h" #include "cus_l2r.h" #include "cnf_l2r.h" #include "mon_l2r.h" #include "prim.h" #include "pei.h" #include "tok.h" #include "dti.h" /* functionality of the dti library */ #include "cl_ribu.h" #include "l2r.h" /*==== CONST =======================================================*/ /*==== TYPES =======================================================*/ /*==== VAR EXPORT ==================================================*/ /*==== VAR LOCAL ===================================================*/ /*==== FUNCTIONS ===================================================*/ /* +------------------------------------------------------------------------------ | Function : sig_dti_up_data_received_ind +------------------------------------------------------------------------------ | Description : Process primitive DTI2_DATA_REQ received from CSDIWF. | | Parameters : dti_data_req - | | | Return : - +------------------------------------------------------------------------------ */ GLOBAL void sig_dti_up_data_received_ind(T_DTI2_DATA_REQ *dti_data_req) { T_UP *dup = &l2r_data->up; TRACE_FUNCTION ("sig_dti_up_data_received_ind()"); PACCESS (dti_data_req); switch (GET_STATE (UP)) { case UP_CONNECTED: { if (GET_STATE (DTI) NEQ DTI_CLOSED) { /* * do not send flow control primitives automatically */ dti_stop(l2r_hDTI, L2R_DTI_UP_DEF_INSTANCE, L2R_DTI_UP_INTERFACE, L2R_DTI_UP_CHANNEL); } SET_STATE (UP_UL, IW_IDLE); dup->Prim = dti_data_req; /* detect break request */ if (dup->Prim->parameters.st_lines.st_break_len NEQ DTI_BREAK_OFF) { sig_up_mgt_break_ind(dup->Prim); } else { up_store_data(); } switch (GET_STATE (UP_LL)) { case ISW_WAIT: if (dup->LLFlow EQ FL_INACTIVE AND dup->RiBu.idx.filled) { /* L_UDR_1 */ TIMERSTOP (TIMER_TUP_SND); up_send_current_prim(); if (!dup->RiBu.idx.filled) { SET_STATE (UP_LL, ISW_IDLE); } else { SET_STATE (UP_LL, ISW_SEND); } } else { /* L_UDR_2 */ if( dup->LastSentFlow EQ dup->MrgFlow ) return; TIMERSTOP (TIMER_TUP_SND); switch (dup->LLFlow) { case FL_INACTIVE: up_send_prim_timeout(); break; case FL_ACTIVE: up_send_empty_frame(dup->LastSentSa, dup->LastSentSb, dup->MrgFlow); break; } if (!dup->RiBu.idx.filled) { SET_STATE (UP_LL, ISW_IDLE); } else { SET_STATE (UP_LL, ISW_SEND); } } break; default: if (!dup->RiBu.idx.filled) /* no primitive is ready */ return; /* L_UDR3 */ up_check_flow(); up_check_alloc(); SET_STATE (UP_LL, ISW_SEND); break; } break; } } } /* +------------------------------------------------------------------------------ | Function : up_rlp_ready_ind +------------------------------------------------------------------------------ | Description : Process primitive RLP_READY_IND received from RLP. | | Parameters : rlp_ready_ind - | | | Return : - +------------------------------------------------------------------------------ */ GLOBAL void up_rlp_ready_ind(T_RLP_READY_IND *rlp_ready_ind) { T_UP *dup = &l2r_data->up; TRACE_FUNCTION ("rlp_ready_ind()"); PACCESS (rlp_ready_ind); switch (GET_STATE (UP)) { case UP_CONNECTED: switch (GET_STATE (UP_LL)) { case ISW_SEND: if (dup->LLFlow EQ FL_INACTIVE OR dup->UrgentMsg) { up_send_current_prim(); if (!dup->RiBu.idx.filled) { SET_STATE (UP_LL, ISW_IDLE); } } else { if (dup->LastSentFlow NEQ dup->MrgFlow) { up_send_empty_frame(dup->LastSentSa, dup->LastSentSb, dup->MrgFlow); } else { SET_STATE (UP_LL, ISW_WAIT); TIMERSTART(TIMER_TUP_SND, LL_TO); } } break; default: SET_STATE (UP_LL, ISW_WAIT); TIMERSTART(TIMER_TUP_SND, LL_TO); break; } break; case UP_REMAP: SET_STATE (UP_LL, ISW_WAIT); break; } PFREE (rlp_ready_ind); }