diff options
| author | Joel Sherrill <joel.sherrill@OARcorp.com> | 2003-07-18 14:47:55 +0000 |
|---|---|---|
| committer | Joel Sherrill <joel.sherrill@OARcorp.com> | 2003-07-18 14:47:55 +0000 |
| commit | fbbe5fde57bdc9d0c7f809931c2addb43bc1bd42 (patch) | |
| tree | 52468f8511082fc9893f46b9020817d23bf0c398 /cpukit/score/src/watchdoginsert.c | |
| parent | Fixed formatting so scripts work. (diff) | |
| download | rtems-fbbe5fde57bdc9d0c7f809931c2addb43bc1bd42.tar.bz2 | |
2003-07-18 Till Straumann <strauman@slac.stanford.edu>
PR 430/rtems
* include/rtems/score/watchdog.h: _Watchdog_Ticks_since_boot should
be a VOLATILE variable.
* src/watchdoginsert.c: 'restart' algorithm needs to enforce
reloading the list head in case a TICK interrupt during ISR_Flash()
modified the list. This is achieved by a proper VOLATILE cast.
Also _Watchdog_Sync_count++ should be protected by _ISR_Disable
(prevent corruption in case ISR calls watchdoginsert)
* src/watchdogadjust.c: ISR protection added.
* src/watchdogtickle.c: ISR protection added.
NOTE: PowerPC BSPs using the new exception processing MUST BE UPDATED
to maintain _ISR_Nest_level. See also PR288 which provides fixes
for the affected BSPs distributed with RTEMS.
Diffstat (limited to 'cpukit/score/src/watchdoginsert.c')
| -rw-r--r-- | cpukit/score/src/watchdoginsert.c | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/cpukit/score/src/watchdoginsert.c b/cpukit/score/src/watchdoginsert.c index 43c1eacd76..0602a0c9b6 100644 --- a/cpukit/score/src/watchdoginsert.c +++ b/cpukit/score/src/watchdoginsert.c @@ -38,13 +38,28 @@ void _Watchdog_Insert( insert_isr_nest_level = _ISR_Nest_level; the_watchdog->state = WATCHDOG_BEING_INSERTED; + _ISR_Disable( level ); + _Watchdog_Sync_count++; + restart: delta_interval = the_watchdog->initial; - _ISR_Disable( level ); - - for ( after = _Watchdog_First( header ) ; + /* + * We CANT use _Watchdog_First() here, because a TICK interrupt + * could modify the chain during the _ISR_Flash() below. Hence, + * the header is pointing to volatile data. The _Watchdog_First() + * INLINE routine (but not the macro - note the subtle difference) + * casts away the 'volatile'... + * + * Also, this is only necessary because we call no other routine + * from this piece of code, hence the compiler thinks it's safe to + * cache *header!! + * + * Till Straumann, 7/2003 (gcc-3.2.2 -O4 on powerpc) + * + */ + for ( after = (Watchdog_Control *) ((volatile Chain_Control *)header)->first ; ; after = _Watchdog_Next( after ) ) { @@ -75,7 +90,6 @@ restart: if ( _Watchdog_Sync_level > insert_isr_nest_level ) { _Watchdog_Sync_level = insert_isr_nest_level; - _ISR_Enable( level ); goto restart; } } |