FreeCalypso > hg > fc-tourmaline
view src/cs/layer1/cust0/ind_os.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 | 4e78acac3d88 |
| children |
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/************* Revision Controle System Header ************* * GSM Layer 1 software * IND_OS.C * * Filename ind_os.c * Version 1.1 * Date 04/26/00 * ************* Revision Controle System Header *************/ // Nucleus include files. #include "nucleus.h" #include "tc_defs.h" #include "sys_types.h" #include "ind_os.h" #include "l1_confg.h" // Layer1 and debug include files. #include "l1_types.h" #include "l1_const.h" #if (L1_GTT == 1) #include "l1gtt_const.h" #include "l1gtt_defty.h" #endif //#if ((ANALOG == 1) || (ANALOG == 2)) // #include "spi_drv.h" //#endif #if TESTMODE #include "l1tm_defty.h" #endif #include "l1audio_const.h" #include "l1audio_cust.h" #include "l1audio_defty.h" #include "l1_defty.h" #include "l1_msgty.h" #include "l1_varex.h" #if (CHIPSET == 2 || CHIPSET == 3 || CHIPSET == 4 || CHIPSET == 5 || CHIPSET == 6 || CHIPSET == 7 || CHIPSET == 8 || CHIPSET == 10 || CHIPSET == 11 || CHIPSET == 12) #include "ulpd.h" #endif extern UWORD32 TCD_Priority_Groups; extern TC_HCB *TCD_Active_HISR_Heads[TC_HISR_PRIORITIES]; extern VOID *TCD_Current_Thread; extern TC_HCB *TCD_Active_HISR_Tails[TC_HISR_PRIORITIES]; extern INT TMD_Timer_State; extern UWORD32 TMD_Timer; // for big sleep extern TC_PROTECT TCD_System_Protect; /*-------------------------------------------------------*/ /* int ind_os_sleep() */ /*-------------------------------------------------------*/ /* Parameters : none */ /* Return : */ /* Functionality : Suspend the thread an interval */ /* of millisecs. */ /* Limitation : */ /*-------------------------------------------------------*/ T_OS_RETURN ind_os_sleep (SYS_UWORD32 millisecs) { NU_Sleep ((SYS_UWORD32) millisecs); return OS_OK; } /*-------------------------------------------------------*/ /* int OS_get_inactivity_ticks() */ /*-------------------------------------------------------*/ /* Parameters : none */ /* Return : Number of ticks of inactivity */ /* 0 means immediate activity planned */ /* -1 means no activity planned */ /* Functionality : Evaluates the OS activity planned */ /* by looking at ready tasks, activated */ /* HISR and the elapsed time of the timers*/ /* Limitation : Must be protected from H/W interrupts */ /*-------------------------------------------------------*/ int OS_get_inactivity_ticks(void) { int i; // Returns immediate activity if a task is ready if (TCD_Priority_Groups) return 0; //for all HISR priorities for (i = 0; i < TC_HISR_PRIORITIES ; i++) { // if no hisr of priority "i" ==> go to next priority if (TCD_Active_HISR_Heads[i] == 0) continue; // the first hisr is NOT the current one (frame hisr) so it may be // with other priority ==> abort if (TCD_Active_HISR_Heads[i] != TCD_Current_Thread) return 0; // the last hisr is NOT the current one (frame hisr) so there is // at least another hisr with same priority ==> abort if (TCD_Active_HISR_Tails[i] != TCD_Current_Thread) return 0; // the first and last hisrs are the current one (frame hisr) but // there are several occurences of it ! ==> abort if ( (TCD_Active_HISR_Heads[i]->tc_activation_count != 1)) return 0; } // Returns remaining ticks number if any timer is active if (TMD_Timer_State == TM_ACTIVE) // any active timer ? { if (TMD_Timer <= MIN_SLEEP_TIME) return(0); else return TMD_Timer; } // Returns not activity if no timer active if (TMD_Timer_State == TM_NOT_ACTIVE) return -1; else // otherwise, returns immediate activity if a timer is expired (TM_EXPIRED) return(0); } /*-------------------------------------------------------*/ /* int OS_system_protect() */ /*-------------------------------------------------------*/ /* Parameters : none */ /* Return : The Thread Control Block of the thread */ /* which already owns the protection or */ /* 0 if no protection */ /* Functionality : Checks whether the system structures */ /* are already protected or not */ /*-------------------------------------------------------*/ void OS_system_protect (void) { NU_Protect((NU_PROTECT*) &TCD_System_Protect); } /*-------------------------------------------------------*/ /* int OS_system_Unprotect() */ /*-------------------------------------------------------*/ /* Parameters : none */ /* Return : */ /* Functionality : unprotect the system structures */ /*-------------------------------------------------------*/ void OS_system_Unprotect (void) { NU_Unprotect(); }
