DP: use real module deadline calculation in DP

this commit enables (re) calculation of all DP
modules deadlines at every DP scheduler run.

It calculates all deadlines based on current buffers
status and modules needs, as described

Signed-off-by: Marcin Szkudlinski <marcin.szkudlinski@intel.com>

Author: marcinszkudlinski

src/schedule/zephyr_dp_schedule.c

@@ -30,12 +30,15 @@ DECLARE_TR_CTX(dp_tr, SOF_UUID(dp_sched_uuid), LOG_LEVEL_INFO);
 struct scheduler_dp_data {
 	struct list_item tasks;		/* list of active dp tasks */
 	struct task ll_tick_src;	/* LL task - source of DP tick */
+	uint32_t last_ll_tick_timestamp;/* a timestamp as k_cycle_get_32 of last LL tick,
+					 * "NOW" for DP deadline calculation
+					 */
+
 };
 
 struct task_dp_pdata {
 	k_tid_t thread_id;		/* zephyr thread ID */
 	struct k_thread thread;		/* memory space for a thread */
-	uint32_t deadline_clock_ticks;	/* dp module deadline in Zephyr ticks */
 	k_thread_stack_t __sparse_cache *p_stack;	/* pointer to thread stack */
 	size_t stack_size;		/* size of the stack in bytes */
 	struct k_sem sem;		/* semaphore for task scheduling */
@@ -555,31 +558,30 @@ static enum task_state scheduler_dp_ll_tick_dummy(void *data)
  * Now - pipeline is in stable state, CPU used almost in 100% (it would be 100% if DP3
  * needed 1.2ms for processing - but the example would be too complicated)
  */
-void scheduler_dp_ll_tick(void *receiver_data, enum notify_id event_type, void *caller_data)
+
+/* Go through all DP tasks and recalculate their readness and dedlines
+ * NOT REENTRANT, should be called with scheduler_dp_lock()
+ */
+static void scheduler_dp_recalculate(struct scheduler_dp_data *dp_sch, bool is_ll_post_run)
 {
-	(void)receiver_data;
-	(void)event_type;
-	(void)caller_data;
 	struct list_item *tlist;
 	struct task *curr_task;
 	struct task_dp_pdata *pdata;
-	unsigned int lock_key;
-	struct scheduler_dp_data *dp_sch = scheduler_get_data(SOF_SCHEDULE_DP);
 
-	lock_key = scheduler_dp_lock();
 	list_for_item(tlist, &dp_sch->tasks) {
 		curr_task = container_of(tlist, struct task, list);
 		pdata = curr_task->priv_data;
 		struct processing_module *mod = pdata->mod;
 
 		/* decrease number of LL ticks/cycles left till the module reaches its deadline */
-		if (pdata->ll_cycles_to_start) {
+		if (mod->dp_startup_delay && is_ll_post_run && pdata->ll_cycles_to_start) {
 			pdata->ll_cycles_to_start--;
 			if (!pdata->ll_cycles_to_start)
-				/* deadline reached, clear startup delay flag.
+				/* delayed start complete, clear startup delay flag.
 				 * see dp_startup_delay comment for details
 				 */
 				mod->dp_startup_delay = false;
+
 		}
 
 		if (curr_task->state == SOF_TASK_STATE_QUEUED) {
@@ -590,16 +592,58 @@ void scheduler_dp_ll_tick(void *receiver_data, enum notify_id event_type, void *
 							       mod->sinks,
 							       mod->num_of_sinks);
 			if (mod_ready) {
-				/* set a deadline for given num of ticks, starting now */
-				k_thread_deadline_set(pdata->thread_id,
-						      pdata->deadline_clock_ticks);
-
 				/* trigger the task */
 				curr_task->state = SOF_TASK_STATE_RUNNING;
+				if (mod->dp_startup_delay && !pdata->ll_cycles_to_start) {
+					/* first time run - use delayed start */
+					pdata->ll_cycles_to_start =
+						module_get_LPT(pdata->mod) / LL_TIMER_PERIOD_US;
+
+					/* in case LPT < LL cycle - delay at least cycle */
+					if (!pdata->ll_cycles_to_start)
+						pdata->ll_cycles_to_start = 1;
+				}
+
 				k_sem_give(&pdata->sem);
 			}
 		}
+		if (curr_task->state == SOF_TASK_STATE_RUNNING) {
+			/* (re) calculate deadline for all running tasks */
+			/* get module deadline in us*/
+			uint32_t deadline = module_get_deadline(mod);
+
+			/* round down to 1ms */
+			deadline = deadline / 1000;
+
+			/* calculate number of ticks */
+			deadline = deadline * (CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC / 1000);
+
+			/* add to "NOW", overflows are OK  */
+			deadline = dp_sch->last_ll_tick_timestamp + deadline;
+
+			/* set in Zephyr. Note that it may be in past, it does not matter,
+			 * Zephyr still will schedule the thread with earlier deadline
+			 * first
+			 */
+			k_thread_absolute_deadline_set(pdata->thread_id, deadline);
+		}
 	}
+}
+
+void scheduler_dp_ll_tick(void *receiver_data, enum notify_id event_type, void *caller_data)
+{
+	(void)receiver_data;
+	(void)event_type;
+	(void)caller_data;
+	unsigned int lock_key;
+	struct scheduler_dp_data *dp_sch = scheduler_get_data(SOF_SCHEDULE_DP);
+
+	if (event_type == NOTIFIER_ID_LL_PRE_RUN)
+		/* remember current timestamp as "NOW" */
+		dp_sch->last_ll_tick_timestamp = k_cycle_get_32();
+
+	lock_key = scheduler_dp_lock();
+	scheduler_dp_recalculate(dp_sch, event_type == NOTIFIER_ID_LL_POST_RUN);
 	scheduler_dp_unlock(lock_key);
 }
 
@@ -663,6 +707,7 @@ static void dp_thread_fn(void *p1, void *p2, void *p3)
 	unsigned int lock_key;
 	enum task_state state;
 	bool task_stop;
+	struct scheduler_dp_data *dp_sch = scheduler_get_data(SOF_SCHEDULE_DP);
 
 	do {
 		/*
@@ -704,6 +749,11 @@ static void dp_thread_fn(void *p1, void *p2, void *p3)
 		/* if true exit the while loop, terminate the thread */
 		task_stop = task->state == SOF_TASK_STATE_COMPLETED ||
 			task->state == SOF_TASK_STATE_CANCEL;
+		/* recalculate all DP tasks readiness and deadlines
+		 * TODO: it should be for all tasks, for all cores
+		 * currently its limited to current core only
+		 */
+		scheduler_dp_recalculate(dp_sch, false);
 
 		scheduler_dp_unlock(lock_key);
 	} while (!task_stop);
@@ -719,7 +769,6 @@ static int scheduler_dp_task_shedule(void *data, struct task *task, uint64_t sta
 	struct scheduler_dp_data *dp_sch = (struct scheduler_dp_data *)data;
 	struct task_dp_pdata *pdata = task->priv_data;
 	unsigned int lock_key;
-	uint64_t deadline_clock_ticks;
 	int ret;
 
 	lock_key = scheduler_dp_lock();
@@ -755,14 +804,6 @@ static int scheduler_dp_task_shedule(void *data, struct task *task, uint64_t sta
 	task->state = SOF_TASK_STATE_QUEUED;
 	list_item_prepend(&task->list, &dp_sch->tasks);
 
-	deadline_clock_ticks = period * CONFIG_SYS_CLOCK_TICKS_PER_SEC;
-	/* period/deadline is in us - convert to seconds in next step
-	 * or it always will be zero because of integer calculation
-	 */
-	deadline_clock_ticks /= 1000000;
-
-	pdata->deadline_clock_ticks = deadline_clock_ticks;
-	pdata->ll_cycles_to_start = period / LL_TIMER_PERIOD_US;
 	pdata->mod->dp_startup_delay = true;
 	scheduler_dp_unlock(lock_key);
 
@@ -804,6 +845,7 @@ int scheduler_dp_init(void)
 	if (ret)
 		return ret;
 
+	notifier_register(NULL, NULL, NOTIFIER_ID_LL_PRE_RUN, scheduler_dp_ll_tick, 0);
 	notifier_register(NULL, NULL, NOTIFIER_ID_LL_POST_RUN, scheduler_dp_ll_tick, 0);
 
 	return 0;