Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 6f58486..0427a86 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -1,10 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *	linux/kernel/softirq.c
  *
  *	Copyright (C) 1992 Linus Torvalds
  *
- *	Distribute under GPLv2.
- *
  *	Rewritten. Old one was good in 2.2, but in 2.3 it was immoral. --ANK (990903)
  */
 
@@ -89,7 +88,8 @@
 
 	if (pending & SOFTIRQ_NOW_MASK)
 		return false;
-	return tsk && (tsk->state == TASK_RUNNING);
+	return tsk && (tsk->state == TASK_RUNNING) &&
+		!__kthread_should_park(tsk);
 }
 
 /*
@@ -257,9 +257,9 @@
 	int softirq_bit;
 
 	/*
-	 * Mask out PF_MEMALLOC s current task context is borrowed for the
-	 * softirq. A softirq handled such as network RX might set PF_MEMALLOC
-	 * again if the socket is related to swap
+	 * Mask out PF_MEMALLOC as the current task context is borrowed for the
+	 * softirq. A softirq handled, such as network RX, might set PF_MEMALLOC
+	 * again if the socket is related to swapping.
 	 */
 	current->flags &= ~PF_MEMALLOC;
 
@@ -301,7 +301,8 @@
 		pending >>= softirq_bit;
 	}
 
-	rcu_bh_qs();
+	if (__this_cpu_read(ksoftirqd) == current)
+		rcu_softirq_qs();
 	local_irq_disable();
 
 	pending = local_softirq_pending();
@@ -571,57 +572,6 @@
 }
 EXPORT_SYMBOL(tasklet_kill);
 
-/*
- * tasklet_hrtimer
- */
-
-/*
- * The trampoline is called when the hrtimer expires. It schedules a tasklet
- * to run __tasklet_hrtimer_trampoline() which in turn will call the intended
- * hrtimer callback, but from softirq context.
- */
-static enum hrtimer_restart __hrtimer_tasklet_trampoline(struct hrtimer *timer)
-{
-	struct tasklet_hrtimer *ttimer =
-		container_of(timer, struct tasklet_hrtimer, timer);
-
-	tasklet_hi_schedule(&ttimer->tasklet);
-	return HRTIMER_NORESTART;
-}
-
-/*
- * Helper function which calls the hrtimer callback from
- * tasklet/softirq context
- */
-static void __tasklet_hrtimer_trampoline(unsigned long data)
-{
-	struct tasklet_hrtimer *ttimer = (void *)data;
-	enum hrtimer_restart restart;
-
-	restart = ttimer->function(&ttimer->timer);
-	if (restart != HRTIMER_NORESTART)
-		hrtimer_restart(&ttimer->timer);
-}
-
-/**
- * tasklet_hrtimer_init - Init a tasklet/hrtimer combo for softirq callbacks
- * @ttimer:	 tasklet_hrtimer which is initialized
- * @function:	 hrtimer callback function which gets called from softirq context
- * @which_clock: clock id (CLOCK_MONOTONIC/CLOCK_REALTIME)
- * @mode:	 hrtimer mode (HRTIMER_MODE_ABS/HRTIMER_MODE_REL)
- */
-void tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer,
-			  enum hrtimer_restart (*function)(struct hrtimer *),
-			  clockid_t which_clock, enum hrtimer_mode mode)
-{
-	hrtimer_init(&ttimer->timer, which_clock, mode);
-	ttimer->timer.function = __hrtimer_tasklet_trampoline;
-	tasklet_init(&ttimer->tasklet, __tasklet_hrtimer_trampoline,
-		     (unsigned long)ttimer);
-	ttimer->function = function;
-}
-EXPORT_SYMBOL_GPL(tasklet_hrtimer_init);
-
 void __init softirq_init(void)
 {
 	int cpu;
@@ -699,7 +649,7 @@
 	/* Find end, append list for that CPU. */
 	if (&per_cpu(tasklet_vec, cpu).head != per_cpu(tasklet_vec, cpu).tail) {
 		*__this_cpu_read(tasklet_vec.tail) = per_cpu(tasklet_vec, cpu).head;
-		this_cpu_write(tasklet_vec.tail, per_cpu(tasklet_vec, cpu).tail);
+		__this_cpu_write(tasklet_vec.tail, per_cpu(tasklet_vec, cpu).tail);
 		per_cpu(tasklet_vec, cpu).head = NULL;
 		per_cpu(tasklet_vec, cpu).tail = &per_cpu(tasklet_vec, cpu).head;
 	}