FreeCalypso > hg > fc-tourmaline
view src/cs/os/nucleus/tm_defs.h @ 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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/*************************************************************************/ /* */ /* Copyright (c) 1993-1994 Accelerated Technology, Inc. */ /* */ /* PROPRIETARY RIGHTS of Accelerated Technology are involved in the */ /* subject matter of this material. All manufacturing, reproduction, */ /* use, and sales rights pertaining to this subject matter are governed */ /* by the license agreement. The recipient of this software implicitly */ /* accepts the terms of the license. */ /* */ /*************************************************************************/ /*************************************************************************/ /* */ /* FILE NAME VERSION */ /* */ /* tm_defs.h PLUS 1.1 */ /* */ /* COMPONENT */ /* */ /* TM - Timer Management */ /* */ /* DESCRIPTION */ /* */ /* This file contains data structure definitions and constants for */ /* the Timer Management component. */ /* */ /* AUTHOR */ /* */ /* William E. Lamie, Accelerated Technology, Inc. */ /* */ /* DATA STRUCTURES */ /* */ /* TM_TCB Timer control block */ /* TM_APP_TCB Application timer control */ /* block */ /* */ /* FUNCTIONS */ /* */ /* None */ /* */ /* DEPENDENCIES */ /* */ /* cs_defs.h Common service definitions */ /* tc_defs.h Thread control definitions */ /* */ /* HISTORY */ /* */ /* NAME DATE REMARKS */ /* */ /* W. Lamie 03-01-1993 Created initial version 1.0 */ /* D. Lamie 04-19-1993 Verified version 1.0 */ /* W. Lamie 03-01-1994 Moved include files outside of */ /* the file #ifndef to allow the */ /* use of actual data structures, */ /* resulting in version 1.1 */ /* R. Pfaff - */ /* D. Lamie 03-18-1994 Verified version 1.1 */ /* */ /*************************************************************************/ #include "cs_defs.h" /* Common service constants */ /* Check to see if the file has been included already. */ #ifndef TM_DEFS #define TM_DEFS /* Define constants local to this component. */ #define TM_TIMER_ID 0x54494d45UL #define TM_ACTIVE 0 #define TM_NOT_ACTIVE 1 #define TM_EXPIRED 2 #define TM_TASK_TIMER 0 #define TM_APPL_TIMER 1 /* Define the Timer Control Block data type. */ typedef struct TM_TCB_STRUCT { INT tm_timer_type; /* Application/Task */ UNSIGNED tm_remaining_time; /* Remaining time */ VOID *tm_information; /* Information pointer */ struct TM_TCB_STRUCT *tm_next_timer, /* Next timer in list */ *tm_previous_timer; /* Previous timer in list*/ } TM_TCB; /* Define Application's Timer Control Block data type. */ typedef struct TM_APP_TCB_STRUCT { CS_NODE tm_created; /* Node for linking to */ /* created timer list */ UNSIGNED tm_id; /* Internal TCB ID */ CHAR tm_name[NU_MAX_NAME]; /* Timer name */ VOID (*tm_expiration_routine)(UNSIGNED); /* Expiration function */ UNSIGNED tm_expiration_id; /* Expiration ID */ INT tm_enabled; /* Timer enabled flag */ UNSIGNED tm_expirations; /* Number of expirations */ UNSIGNED tm_initial_time; /* Initial time */ UNSIGNED tm_reschedule_time; /* Reschedule time */ TM_TCB tm_actual_timer; /* Actual timer internals*/ } TM_APP_TCB; /* Include this file here, since it contains references to the timer definition structure that is defined by this file. */ #include "tc_defs.h" #endif