diff options
Diffstat (limited to 'core/cortex-m0/task.c')
| -rw-r--r-- | core/cortex-m0/task.c | 85 |
1 files changed, 48 insertions, 37 deletions
diff --git a/core/cortex-m0/task.c b/core/cortex-m0/task.c index 4e9c66ee95..e51621b41e 100644 --- a/core/cortex-m0/task.c +++ b/core/cortex-m0/task.c @@ -123,19 +123,6 @@ uint32_t scratchpad[17]; static task_ *current_task = (task_ *)scratchpad; /* - * Should IRQs chain to svc_handler()? This should be set if either of the - * following is true: - * - * 1) Task scheduling has started, and task profiling is enabled. Task - * profiling does its tracking in svc_handler(). - * - * 2) An event was set by an interrupt; this could result in a higher-priority - * task unblocking. After checking for a task switch, svc_handler() will clear - * the flag (unless profiling is also enabled; then the flag remains set). - */ -int need_resched_or_profiling; - -/* * Bitmap of all tasks ready to be run. * * Currently all tasks are enabled at startup. @@ -209,7 +196,9 @@ task_ *__svc_handler(int desched, task_id_t resched) * start time explicitly. */ if (exc == 0xb) { - exc_start_time = get_time().val; + t = get_time().val; + current_task->runtime += (t - exc_end_time); + exc_end_time = t; svc_calls++; } #endif @@ -237,22 +226,11 @@ task_ *__svc_handler(int desched, task_id_t resched) next = __task_id_to_ptr(31 - __builtin_clz(tasks_ready)); #ifdef CONFIG_TASK_PROFILING - /* Track time in interrupts */ + /* Track additional time in re-sched exception context */ t = get_time().val; - exc_total_time += (t - exc_start_time); + exc_total_time += (t - exc_end_time); - /* - * Bill the current task for time between the end of the last interrupt - * and the start of this one. - */ - current->runtime += (exc_start_time - exc_end_time); exc_end_time = t; -#else - /* - * Don't chain here from interrupts until the next time an interrupt - * sets an event. - */ - need_resched_or_profiling = 0; #endif /* Switch to new task */ @@ -284,6 +262,18 @@ void __schedule(int desched, int resched) asm("svc 0" : : "r"(p0), "r"(p1)); } +void pendsv_handler(void) +{ + /* Clear pending flag */ + CPU_SCB_ICSR = (1 << 27); + + /* ensure we have priority 0 during re-scheduling */ + __asm__ __volatile__("cpsid i"); + /* re-schedule the highest priority task */ + svc_handler(0, 0); + __asm__ __volatile__("cpsie i"); +} + #ifdef CONFIG_TASK_PROFILING void task_start_irq_handler(void *excep_return) { @@ -302,14 +292,33 @@ void task_start_irq_handler(void *excep_return) irq_dist[irq]++; /* - * Continue iff a rescheduling event happened or profiling is active, - * and we are not called from another exception (this must match the - * logic for when we chain to svc_handler() below). + * Continue iff the tasks are ready and we are not called from another + * exception (as the time accouting is done in the outer irq). */ - if (!need_resched_or_profiling || (((uint32_t)excep_return & 0xf) == 1)) + if (!start_called || ((uint32_t)excep_return & 0xf) == 1) return; exc_start_time = t; + /* + * Bill the current task for time between the end of the last interrupt + * and the start of this one. + */ + current_task->runtime += (exc_start_time - exc_end_time); +} + +void task_end_irq_handler(void *excep_return) +{ + uint64_t t = get_time().val; + /* + * Continue iff the tasks are ready and we are not called from another + * exception (as the time accouting is done in the outer irq). + */ + if (!start_called || ((uint32_t)excep_return & 0xf) == 1) + return; + + /* Track time in interrupts */ + exc_total_time += (t - exc_start_time); + exc_end_time = t; } #endif @@ -357,10 +366,13 @@ uint32_t task_set_event(task_id_t tskid, uint32_t event, int wait) if (in_interrupt_context()) { /* The receiver might run again */ atomic_or(&tasks_ready, 1 << tskid); -#ifndef CONFIG_TASK_PROFILING - if (start_called) - need_resched_or_profiling = 1; -#endif + if (start_called) { + /* + * Trigger the scheduler when there's + * no other irqs happening. + */ + CPU_SCB_ICSR = (1 << 28); + } } else { if (wait) { return __wait_evt(-1, tskid); @@ -646,7 +658,6 @@ int task_start(void) #ifdef CONFIG_TASK_PROFILING task_start_time = exc_end_time = get_time().val; #endif - start_called = 1; - return __task_start(&need_resched_or_profiling); + return __task_start(&start_called); } |