FreeCalypso > hg > fc-tourmaline
view src/g23m-fad/ppp/ppp_paps.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 : | Modul : +----------------------------------------------------------------------------- | 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 PPP and implements all | functions to handles the incoming process internal signals as | described in the SDL-documentation (PAP-statemachine) +----------------------------------------------------------------------------- */ #ifndef PPP_PAPS_C #define PPP_PAPS_C #endif /* !PPP_PAPS_C */ #define ENTITY_PPP /*==== INCLUDES =============================================================*/ #include "typedefs.h" /* to get Condat data types */ #include "vsi.h" /* to get a lot of macros */ #include "macdef.h" /* to get a lot of macros */ #include "custom.h" /* to get a lot of macros */ #include "gsm.h" /* to get a lot of macros */ #include "cnf_ppp.h" /* to get cnf-definitions */ #include "mon_ppp.h" /* to get mon-definitions */ #include "prim.h" /* to get the definitions of used SAP and directions */ #include "dti.h" /* to get the DTILIB definitions */ #include "ppp.h" /* to get the global entity definitions */ #include "ppp_papf.h" /* to get function interface from pap */ #include "ppp_arbf.h" /* to get function interface from arb */ #include "ppp_ftxs.h" /* to get signal interface from ftx */ #include "ppp_arbs.h" /* to get signal interface from arb */ #include "ppp_rts.h" /* to get the rt signal interface */ /*==== CONST ================================================================*/ /*==== LOCAL VARS ===========================================================*/ /*==== PRIVATE FUNCTIONS ====================================================*/ /*==== PUBLIC FUNCTIONS =====================================================*/ /* +------------------------------------------------------------------------------ | Function : sig_arb_pap_packet_req +------------------------------------------------------------------------------ | Description : Handles the internal signal SIG_ARB_PAP_PACKET_REQ | | Parameters : packet - pointer to a generic data descriptor | +------------------------------------------------------------------------------ */ GLOBAL void sig_arb_pap_packet_req (T_desc2* packet) { UBYTE forward; TRACE_ISIG( "sig_arb_pap_packet_req" ); /* * depend on the code-field call appropriate function */ switch(packet->buffer[0]) { case CODE_AUTH_REQ: pap_rar(&packet, &forward); break; case CODE_AUTH_ACK: pap_raa(packet, &forward); break; case CODE_AUTH_NAK: pap_ran(packet, &forward); break; default: forward = FORWARD_DISCARD; break; } switch(forward) { case FORWARD_RARP: /* * send Authentication Ack packets until receive a stop signal from arb * or the counter becomes zero */ SET_STATE( PPP_SERVICE_PAP, PAP_UP ); ppp_data->pap.counter = ppp_data->mc; sig_any_ftx_packet_req(DTI_PID_PAP, packet); /* saa */ if(ppp_data->pap.counter > 0) ppp_data->pap.counter--; sig_any_rt_rrt_req(); sig_any_arb_tlu_ind(); break; case FORWARD_RARN: /* * just send Authentication NAK packet and * wait for next Authentication Request * to avoid endless authentication timer will not restarted */ sig_any_ftx_packet_req(DTI_PID_PAP, packet); /* san */ break; case FORWARD_RAA: /* * Authentication successful */ sig_any_rt_srt_req(); sig_any_arb_tlu_ind(); break; case FORWARD_RAN: /* * send new Authentication Request */ ppp_data->pap.counter = ppp_data->mc; /* * set new identifier */ ppp_data->pap.nari++; /* * create and send authenticate request packet */ pap_get_sar(&packet); sig_any_ftx_packet_req(DTI_PID_PAP, packet); if(ppp_data->pap.counter > 0) ppp_data->pap.counter--; sig_any_rt_rrt_req(); break; default: arb_discard_packet(packet); break; } } /* sig_arb_pap_packet_req() */ /* +------------------------------------------------------------------------------ | Function : sig_arb_pap_open_req +------------------------------------------------------------------------------ | Description : Handles the internal signal SIG_ARB_PAP_OPEN_REQ | | Parameters : no parameters | +------------------------------------------------------------------------------ */ GLOBAL void sig_arb_pap_open_req () { T_desc2* packet; TRACE_ISIG( "sig_arb_pap_open_req" ); SET_STATE( PPP_SERVICE_PAP, PAP_DOWN ); ppp_data->pap.counter = ppp_data->mc; if(ppp_data->mode EQ PPP_CLIENT) { /* * set new identifier */ ppp_data->pap.nari++; /* * create and send authenticate request packet */ pap_get_sar(&packet); sig_any_ftx_packet_req(DTI_PID_PAP, packet); } if(ppp_data->pap.counter > 0) ppp_data->pap.counter--; sig_any_rt_rrt_req(); } /* sig_arb_pap_open_req() */ /* +------------------------------------------------------------------------------ | Function : sig_arb_pap_down_req +------------------------------------------------------------------------------ | Description : Handles the internal signal SIG_ARB_PAP_DOWN_REQ | | Parameters : no parameters | +------------------------------------------------------------------------------ */ GLOBAL void sig_arb_pap_down_req () { TRACE_ISIG( "sig_arb_pap_down_req" ); sig_any_rt_srt_req(); arb_discard_packet(ppp_data->pap.ar_packet); ppp_data->pap.ar_packet = NULL; } /* sig_arb_pap_down_req() */ /* +------------------------------------------------------------------------------ | Function : sig_arb_pap_stop_req +------------------------------------------------------------------------------ | Description : Handles the internal signal SIG_ARB_PAP_STOP_REQ | | Parameters : no parameters | +------------------------------------------------------------------------------ */ GLOBAL void sig_arb_pap_stop_req () { TRACE_ISIG( "sig_arb_pap_stop_req" ); sig_any_rt_srt_req(); } /* sig_arb_pap_stop_req() */ /* +------------------------------------------------------------------------------ | Function : sig_arb_pap_to_req +------------------------------------------------------------------------------ | Description : Handles the internal signal SIG_ARB_PAP_TO_REQ | | Parameters : no parameters | +------------------------------------------------------------------------------ */ GLOBAL void sig_arb_pap_to_req () { T_desc2* packet; TRACE_ISIG( "sig_arb_pap_to_req" ); if (ppp_data->pap.counter EQ 0) { /* * authentication failed (client and server mode) */ if((ppp_data->ppp_cause EQ 0) && (ppp_data->mode EQ PPP_CLIENT)) ppp_data->ppp_cause = PPP_TERM_NO_RESPONSE; sig_any_arb_tlf_ind(); } else { if(ppp_data->mode EQ PPP_CLIENT) { /* * send new authentication request packet */ pap_get_sar(&packet); sig_any_ftx_packet_req(DTI_PID_PAP, packet); } else /* server mode */ { switch( GET_STATE( PPP_SERVICE_PAP ) ) { case PAP_UP: /* * send new authentication ack packet */ pap_get_saa(&packet); sig_any_ftx_packet_req(DTI_PID_PAP, packet); break; } } /* * restart timer */ ppp_data->pap.counter--; sig_any_rt_rrt_req(); } } /* sig_arb_pap_to_req() */