Revert "ANDROID: Revert "Mark HI and TASKLET softirq synchronous""

This reverts commit ea05d25c78  as the
softirq code is rewritten in 5.11-rc1 and massive merge conflicts are
happening.

If this change is still needed, please work with upstream to get the
patches accepted so they can then come into this tree automatically.

Bug: 168521633
Cc: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>
Cc: J. Avila <elavila@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I4ab5adcf06824b0b7d052ea07e8c851c9052fe6b

kernel/softirq.c

@@ -88,12 +88,16 @@ static void wakeup_softirqd(void)
 
 /*
  * If ksoftirqd is scheduled, we do not want to process pending softirqs
- * right now. Let ksoftirqd handle this at its own rate, to get fairness.
+ * right now. Let ksoftirqd handle this at its own rate, to get fairness,
+ * unless we're doing some of the synchronous softirqs.
  */
-static bool ksoftirqd_running(void)
+#define SOFTIRQ_NOW_MASK ((1 << HI_SOFTIRQ) | (1 << TASKLET_SOFTIRQ))
+static bool ksoftirqd_running(unsigned long pending)
 {
 	struct task_struct *tsk = __this_cpu_read(ksoftirqd);
 
+	if (pending & SOFTIRQ_NOW_MASK)
+		return false;
 	return tsk && (tsk->state == TASK_RUNNING) &&
 		!__kthread_should_park(tsk);
 }
@@ -362,7 +366,7 @@ asmlinkage __visible void do_softirq(void)
 
 	pending = local_softirq_pending();
 
-	if (pending && !ksoftirqd_running())
+	if (pending && !ksoftirqd_running(pending))
 		do_softirq_own_stack();
 
 	local_irq_restore(flags);
@@ -396,7 +400,7 @@ void irq_enter(void)
 
 static inline void invoke_softirq(void)
 {
-	if (ksoftirqd_running())
+	if (ksoftirqd_running(local_softirq_pending()))
 		return;
 
 	if (!force_irqthreads) {