FreeCalypso > hg > fc-tourmaline
view src/gpf/inc/nuc/old/qu_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 |
line wrap: on
line source
/*************************************************************************/ /* */ /* Copyright (c) 1993-1996 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 */ /* */ /* qu_defs.h PLUS 1.2 */ /* */ /* COMPONENT */ /* */ /* QU - Queue Management */ /* */ /* DESCRIPTION */ /* */ /* This file contains data structure definitions and constants for */ /* the message Queue component. */ /* */ /* AUTHOR */ /* */ /* William E. Lamie, Accelerated Technology, Inc. */ /* */ /* DATA STRUCTURES */ /* */ /* QU_QCB Queue control block */ /* QU_SUSPEND Queue suspension 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, */ /* removed protection structure, */ /* put padding into structure, */ /* resulting in version 1.1 */ /* R. Pfaff - */ /* D. Lamie 03-18-1994 Verified version 1.1 */ /* M.Q. Qian 04-17-1996 updated to version 1.2 */ /* */ /*************************************************************************/ #include "cs_defs.h" /* Common service constants */ #include "tc_defs.h" /* Thread control constants */ /* Check to see if the file has been included already. */ #ifndef QU_DEFS #define QU_DEFS /* Define constants local to this component. */ #define QU_QUEUE_ID 0x51554555UL /* Define the Queue Control Block data type. */ typedef struct QU_QCB_STRUCT { CS_NODE qu_created; /* Node for linking to */ /* created queue list */ UNSIGNED qu_id; /* Internal QCB ID */ CHAR qu_name[NU_MAX_NAME]; /* Queue name */ DATA_ELEMENT qu_fixed_size; /* Fixed-size messages? */ DATA_ELEMENT qu_fifo_suspend; /* Suspension type flag */ #if PAD_2 DATA_ELEMENT qu_padding[PAD_2]; #endif UNSIGNED qu_queue_size; /* Total size of queue */ UNSIGNED qu_messages; /* Messages in queue */ UNSIGNED qu_message_size; /* Size of each message */ UNSIGNED qu_available; /* Available words */ UNSIGNED_PTR qu_start; /* Start of queue area */ UNSIGNED_PTR qu_end; /* End of queue area + 1 */ UNSIGNED_PTR qu_read; /* Read pointer */ UNSIGNED_PTR qu_write; /* Write pointer */ UNSIGNED qu_tasks_waiting; /* Number of waiting tasks*/ struct QU_SUSPEND_STRUCT *qu_urgent_list; /* Urgent message suspend */ struct QU_SUSPEND_STRUCT *qu_suspension_list; /* Suspension list */ } QU_QCB; /* Define the queue suspension structure. This structure is allocated off of the caller's stack. */ typedef struct QU_SUSPEND_STRUCT { CS_NODE qu_suspend_link; /* Link to suspend blocks */ QU_QCB *qu_queue; /* Pointer to the queue */ TC_TCB *qu_suspended_task; /* Task suspended */ UNSIGNED_PTR qu_message_area; /* Pointer to message area*/ UNSIGNED qu_message_size; /* Message size requested */ UNSIGNED qu_actual_size; /* Actual size of message */ STATUS qu_return_status; /* Return status */ } QU_SUSPEND; #endif