lockdep: irq_pipeline: fix ambiguous naming

lockdep_save/restore_irqs_state might convey the wrong information:
this is not about saving+disabling then conditionally re-enabling the
tracked state, but merely to read/write such state
unconditionally. Let's change this to non-equivocal names.

include/linux/lockdep.h

@@ -593,12 +593,10 @@ do {									\
 		(running_oob() || this_cpu_read(hardirqs_enabled)));	\
 } while (0)
 
-#define lockdep_save_irqs_state(__state)				\
-do {									\
-	(__state) = this_cpu_read(hardirqs_enabled);			\
-} while (0)
+#define lockdep_read_irqs_state()					\
+	({ this_cpu_read(hardirqs_enabled); })
 
-#define lockdep_restore_irqs_state(__state)				\
+#define lockdep_write_irqs_state(__state)				\
 do {									\
 	this_cpu_write(hardirqs_enabled, __state);			\
 } while (0)
@@ -641,8 +639,8 @@ do {									\
 
 # define lockdep_assert_irqs_enabled() do { } while (0)
 # define lockdep_assert_irqs_disabled() do { } while (0)
-# define lockdep_save_irqs_state(__state) do { (void)(__state); } while (0)
-# define lockdep_restore_irqs_state(__state) do { (void)(__state); } while (0)
+# define lockdep_read_irqs_state() 0
+# define lockdep_write_irqs_state(__state) do { (void)(__state); } while (0)
 # define lockdep_assert_in_irq() do { } while (0)
 
 # define lockdep_assert_preemption_enabled() do { } while (0)

kernel/sched/core.c

@@ -9736,7 +9736,7 @@ bool dovetail_context_switch(struct dovetail_altsched_context *out,
 	 * state maintained by lockdep must be preserved across
 	 * switches.
 	 */
-	lockdep_save_irqs_state(lockdep_irqs);
+	lockdep_irqs = lockdep_read_irqs_state();
 
 	switch_to(prev, next, last);
 	barrier();
@@ -9761,7 +9761,7 @@ bool dovetail_context_switch(struct dovetail_altsched_context *out,
 		else
 			preempt_count_sub(STAGE_OFFSET);
 
-		lockdep_restore_irqs_state(lockdep_irqs);
+		lockdep_write_irqs_state(lockdep_irqs);
 
 		/*
 		 * Fixup the interrupt state conversely to what
@@ -9775,7 +9775,7 @@ bool dovetail_context_switch(struct dovetail_altsched_context *out,
 		if (IS_ENABLED(CONFIG_HAVE_PERCPU_PREEMPT_COUNT))
 			preempt_count_set(pc);
 
-		lockdep_restore_irqs_state(lockdep_irqs);
+		lockdep_write_irqs_state(lockdep_irqs);
 	}
 
 	arch_dovetail_switch_finish(leave_inband);