Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 8110514..11ae274 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -576,10 +576,9 @@
 	}
 
 	lockdep_assert_irqs_disabled();
-	trace_rcu_dyntick(TPS("Start"), rdp->dynticks_nesting, 0, rdp->dynticks);
+	trace_rcu_dyntick(TPS("Start"), rdp->dynticks_nesting, 0, atomic_read(&rdp->dynticks));
 	WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !user && !is_idle_task(current));
 	rdp = this_cpu_ptr(&rcu_data);
-	do_nocb_deferred_wakeup(rdp);
 	rcu_prepare_for_idle();
 	rcu_preempt_deferred_qs(current);
 	WRITE_ONCE(rdp->dynticks_nesting, 0); /* Avoid irq-access tearing. */
@@ -618,7 +617,14 @@
  */
 void rcu_user_enter(void)
 {
+	struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
+
 	lockdep_assert_irqs_disabled();
+
+	instrumentation_begin();
+	do_nocb_deferred_wakeup(rdp);
+	instrumentation_end();
+
 	rcu_eqs_enter(true);
 }
 #endif /* CONFIG_NO_HZ_FULL */
@@ -649,14 +655,15 @@
 	 * leave it in non-RCU-idle state.
 	 */
 	if (rdp->dynticks_nmi_nesting != 1) {
-		trace_rcu_dyntick(TPS("--="), rdp->dynticks_nmi_nesting, rdp->dynticks_nmi_nesting - 2, rdp->dynticks);
+		trace_rcu_dyntick(TPS("--="), rdp->dynticks_nmi_nesting, rdp->dynticks_nmi_nesting - 2,
+				  atomic_read(&rdp->dynticks));
 		WRITE_ONCE(rdp->dynticks_nmi_nesting, /* No store tearing. */
 			   rdp->dynticks_nmi_nesting - 2);
 		return;
 	}
 
 	/* This NMI interrupted an RCU-idle CPU, restore RCU-idleness. */
-	trace_rcu_dyntick(TPS("Startirq"), rdp->dynticks_nmi_nesting, 0, rdp->dynticks);
+	trace_rcu_dyntick(TPS("Startirq"), rdp->dynticks_nmi_nesting, 0, atomic_read(&rdp->dynticks));
 	WRITE_ONCE(rdp->dynticks_nmi_nesting, 0); /* Avoid store tearing. */
 
 	if (irq)
@@ -743,7 +750,7 @@
 	rcu_dynticks_task_exit();
 	rcu_dynticks_eqs_exit();
 	rcu_cleanup_after_idle();
-	trace_rcu_dyntick(TPS("End"), rdp->dynticks_nesting, 1, rdp->dynticks);
+	trace_rcu_dyntick(TPS("End"), rdp->dynticks_nesting, 1, atomic_read(&rdp->dynticks));
 	WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !user && !is_idle_task(current));
 	WRITE_ONCE(rdp->dynticks_nesting, 1);
 	WARN_ON_ONCE(rdp->dynticks_nmi_nesting);
@@ -827,7 +834,7 @@
 	}
 	trace_rcu_dyntick(incby == 1 ? TPS("Endirq") : TPS("++="),
 			  rdp->dynticks_nmi_nesting,
-			  rdp->dynticks_nmi_nesting + incby, rdp->dynticks);
+			  rdp->dynticks_nmi_nesting + incby, atomic_read(&rdp->dynticks));
 	WRITE_ONCE(rdp->dynticks_nmi_nesting, /* Prevent store tearing. */
 		   rdp->dynticks_nmi_nesting + incby);
 	barrier();
@@ -2491,7 +2498,6 @@
 		  "%s: Could not start rcuc kthread, OOM is now expected behavior\n", __func__);
 	return 0;
 }
-early_initcall(rcu_spawn_core_kthreads);
 
 /*
  * Handle any core-RCU processing required by a call_rcu() invocation.
@@ -3156,7 +3162,6 @@
 	smp_mb(); /* Ensure RCU read-side usage follows above initialization. */
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
 /*
  * The outgoing function has no further need of RCU, so remove it from
  * the rcu_node tree's ->qsmaskinitnext bit masks.
@@ -3196,6 +3201,7 @@
 	per_cpu(rcu_cpu_started, cpu) = 0;
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
 /*
  * The outgoing CPU has just passed through the dying-idle state, and we
  * are being invoked from the CPU that was IPIed to continue the offline
@@ -3308,6 +3314,7 @@
 	wake_up_process(t);
 	rcu_spawn_nocb_kthreads();
 	rcu_spawn_boost_kthreads();
+	rcu_spawn_core_kthreads();
 	return 0;
 }
 early_initcall(rcu_spawn_gp_kthread);
@@ -3418,11 +3425,25 @@
  * replace the definitions in tree.h because those are needed to size
  * the ->node array in the rcu_state structure.
  */
-static void __init rcu_init_geometry(void)
+void rcu_init_geometry(void)
 {
 	ulong d;
 	int i;
+	static unsigned long old_nr_cpu_ids;
 	int rcu_capacity[RCU_NUM_LVLS];
+	static bool initialized;
+
+	if (initialized) {
+		/*
+		 * Warn if setup_nr_cpu_ids() had not yet been invoked,
+		 * unless nr_cpus_ids == NR_CPUS, in which case who cares?
+		 */
+		WARN_ON_ONCE(old_nr_cpu_ids != nr_cpu_ids);
+		return;
+	}
+
+	old_nr_cpu_ids = nr_cpu_ids;
+	initialized = true;
 
 	/*
 	 * Initialize any unspecified boot parameters.