FreeCalypso > hg > fc-tourmaline
view src/g23m-gprs/sndcp/sndcp_suf.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 : GPRS (8441) | Modul : sndcp_suf.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 (SU-statemachine) +----------------------------------------------------------------------------- */ /*---- HISTORY --------------------------------------------------------------*/ #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_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 : su_get_nsapi +------------------------------------------------------------------------------ | Description : finde the affected nsapi in sn-PDU. | | Parameters : ll_unitdata_req* | Returns : the nsapi | +------------------------------------------------------------------------------ */ GLOBAL U8 su_get_nsapi (T_LL_UNITDESC_REQ* ll_unitdesc_req) { T_desc3* desc3 = NULL; U8 * sndcp_header = NULL; /* Get the descriptor describing the memory area with the sndcp header */ desc3 = (T_desc3*)ll_unitdesc_req->desc_list3.first; sndcp_header = (U8*)desc3->buffer; TRACE_FUNCTION( "su_get_nsapi" ); return (*(sndcp_header + ENCODE_OFFSET_BYTE)) & 0xf; } /* sua_get_nsapi() */ #else /* _SNDCP_DTI_2_ */ /* +------------------------------------------------------------------------------ | Function : su_get_nsapi +------------------------------------------------------------------------------ | Description : finde the affected nsapi in sn-PDU. | | Parameters : ll_unitdata_req* | Returns : the nsapi | +------------------------------------------------------------------------------ */ GLOBAL UBYTE su_get_nsapi (T_LL_UNITDATA_REQ* ll_unitdata_req) { USHORT octet_offset = (ll_unitdata_req->sdu.o_buf) >> 3; TRACE_FUNCTION( "su_get_nsapi" ); return ll_unitdata_req->sdu.buf[octet_offset] & 0xf; } /* su_get_nsapi() */ #endif /* _SNDCP_DTI_2_ */ /* +------------------------------------------------------------------------------ | Function : su_init +------------------------------------------------------------------------------ | Description : The function su_init() .... | | Parameters : | +------------------------------------------------------------------------------ */ GLOBAL void su_init (void) { TRACE_FUNCTION( "su_init" ); /* * Not initialized: * Members of sn_unitdata_q are not set to NULL. * Members of npdu_number_q are not set to 0. * Members of ll_unitdata_q are not set to NULL. */ sndcp_data->su = & sndcp_data->su_base[0]; INIT_STATE(SU_0, SU_LLC_NOT_RECEPTIVE); #ifdef SNDCP_2to1 sndcp_data->su->sapi = PS_SAPI_3; #else sndcp_data->su->sapi = LL_SAPI_3; #endif /*SNDCP_2to1*/ sndcp_data->su = & sndcp_data->su_base[1]; INIT_STATE(SU_1, SU_LLC_NOT_RECEPTIVE); #ifdef SNDCP_2to1 sndcp_data->su->sapi = PS_SAPI_5; #else sndcp_data->su->sapi = LL_SAPI_5; #endif /*SNDCP_2to1*/ sndcp_data->su = & sndcp_data->su_base[2]; INIT_STATE(SU_2, SU_LLC_NOT_RECEPTIVE); #ifdef SNDCP_2to1 sndcp_data->su->sapi = PS_SAPI_9; #else sndcp_data->su->sapi = LL_SAPI_9; #endif /*SNDCP_2to1*/ sndcp_data->su = & sndcp_data->su_base[3]; INIT_STATE(SU_3, SU_LLC_NOT_RECEPTIVE); #ifdef SNDCP_2to1 sndcp_data->su->sapi = PS_SAPI_11; #else sndcp_data->su->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->su = & sndcp_data->su_base[sapi_index]; sndcp_data->su->n201_u = N201_U_DEFAULT; sndcp_data->su->sn_unitdata_q_read = 0; sndcp_data->su->sn_unitdata_q_write = 0; #ifdef _SNDCP_DTI_2_ sndcp_data->su->ll_unitdesc_q_read = 0; sndcp_data->su->ll_unitdesc_q_write = 0; #else /* _SNDCP_DTI_2_ */ sndcp_data->su->ll_unitdata_q_read = 0; sndcp_data->su->ll_unitdata_q_write = 0; #endif /* _SNDCP_DTI_2_ */ sndcp_data->su->cia_state = CIA_IDLE; } } } /* su_init() */ /* +------------------------------------------------------------------------------ | Function : su_next_sn_unitdata_req +------------------------------------------------------------------------------ | Description : If queue with sn_unitdata_req is | not empty, send SIG_SU_CIA_DATA_REQ with next prim from sn_unitdata_req queue | | Parameters : sapi | Pre : cia_state == CIA_IDLE | +------------------------------------------------------------------------------ */ GLOBAL void su_next_sn_unitdata_req (UBYTE sapi) { TRACE_FUNCTION( "su_next_sn_unitdata_req" ); if (sndcp_data->su->sn_unitdata_q_write != sndcp_data->su->sn_unitdata_q_read) { /* * Get sn_unitdata_req from queue. */ T_SN_UNITDATA_REQ* sn_unitdata_req = sndcp_data->su->sn_unitdata_q[sndcp_data->su->sn_unitdata_q_read]; /* * Get npdu_number from queue. */ USHORT npdu_num = sndcp_data->su->npdu_number_q[sndcp_data->su->sn_unitdata_q_read]; UBYTE nsapi = sn_unitdata_req->nsapi; sndcp_data->su->sn_unitdata_q[sndcp_data->su->sn_unitdata_q_read] = NULL; sndcp_data->su->sn_unitdata_q_read = (sndcp_data->su->sn_unitdata_q_read + 1 ) % SN_UNITDATA_Q_LEN; /* * Cia is now busy. Send data. */ sndcp_data->su->cia_state = CIA_BUSY; sig_su_cia_cia_comp_req(sn_unitdata_req, npdu_num, nsapi, sapi); } else if (sndcp_data->su->cia_state == CIA_IDLE) { UBYTE nsapi = 0; for (nsapi = 0; nsapi < SNDCP_NUMBER_OF_NSAPIS; nsapi++) { UBYTE used_sapi = 0; BOOL used = FALSE; sndcp_is_nsapi_used(nsapi, &used); if (used) { sndcp_get_nsapi_sapi(nsapi, &used_sapi); if (used_sapi == sapi) { sig_su_nu_ready_ind(nsapi); } } } } } /* su_next_sn_unitdata_req() */