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idle: add support for nanokernel tickless idle

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The architectures need to add support for it in their nano_cpu_idle()
and nano_cpu_atomic_idle() implementations, as well as in their
interrupt entry and exit code.

Change-Id: I44a241c56e624dc8e32e08db29a84489314cd7a4
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Signed-off-by: Peter Mitsis <peter.mitsis@windriver.com>
This commit is contained in:
Benjamin Walsh 2015-10-05 07:19:39 -07:00 • committed by Anas Nashif
commit 38a601e578
1 changed files with 69 additions and 2 deletions
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71
kernel/nanokernel/idle.c
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@ -22,12 +22,13 @@
* data structure. * data structure.
*/ */
#ifdef CONFIG_ADVANCED_POWER_MANAGEMENT
#include <nanokernel.h> #include <nanokernel.h>
#include <nano_private.h> #include <nano_private.h>
#include <toolchain.h> #include <toolchain.h>
#include <sections.h> #include <sections.h>
#include <drivers/system_timer.h>
#include <wait_q.h>
/** /**
* *
@ -46,4 +47,70 @@ void nano_cpu_set_idle(int32_t ticks)
_nanokernel.idle = ticks; _nanokernel.idle = ticks;
} }
#endif /* CONFIG_ADVANCED_POWER_MANAGEMENT */ #if defined(CONFIG_NANOKERNEL) && defined(CONFIG_TICKLESS_IDLE)
int32_t _sys_idle_ticks_threshold = CONFIG_TICKLESS_IDLE_THRESH;
#if defined(CONFIG_NANO_TIMEOUTS)
static inline int32_t get_next_timeout_expiry(void)
{
return _nano_get_earliest_timeouts_deadline();
}
#else
#define get_next_timeout_expiry(void) TICKS_UNLIMITED
#endif
/**
*
* @brief - obtain number of ticks until next timer expires
*
* Must be called with interrupts locked to prevent the timer queues from
* changing.
*
* @return Number of ticks until next timer expires.
*
*/
static inline int32_t get_next_timer_expiry(void)
{
return _nano_timer_list ? _nano_timer_list->ticks : TICKS_UNLIMITED;
}
static inline int was_in_tickless_idle(void)
{
return (_nanokernel.idle == TICKS_UNLIMITED) ||
(_nanokernel.idle >= _sys_idle_ticks_threshold);
}
static inline int must_enter_tickless_idle(void)
{
/* uses same logic as was_in_tickless_idle() */
return was_in_tickless_idle();
}
static inline int32_t get_next_tick_expiry(void)
{
int32_t timers = get_next_timer_expiry();
int32_t timeouts = get_next_timeout_expiry();
return (int32_t)min((uint32_t)timers, (uint32_t)timeouts);
}
void _power_save_idle(void)
{
_nanokernel.idle = get_next_tick_expiry();
if (must_enter_tickless_idle()) {
_timer_idle_enter((uint32_t)_nanokernel.idle);
}
}
void _power_save_idle_exit(void)
{
if (was_in_tickless_idle()) {
_timer_idle_exit();
_nanokernel.idle = 0;
}
}
#endif /* CONFIG_NANOKERNEL && CONFIG_TICKLESS_IDLE */