jump_label: move 'asm goto' support test to Kconfig

commit e9666d10a5677a494260d60d1fa0b73cc7646eb3 upstream.

Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".

The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:

  #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
  # define HAVE_JUMP_LABEL
  #endif

We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.

Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
[nc: Fix trivial conflicts in 4.19
     arch/xtensa/kernel/jump_label.c doesn't exist yet
     Ensured CC_HAVE_ASM_GOTO and HAVE_JUMP_LABEL were sufficiently
     eliminated]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

6 files changed, 13 insertions, 17 deletions

diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 2e62503bea0d..7c8262635b29 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -18,8 +18,6 @@
 #include <linux/cpu.h>
 #include <asm/sections.h>
 
-#ifdef HAVE_JUMP_LABEL
-
 /* mutex to protect coming/going of the the jump_label table */
 static DEFINE_MUTEX(jump_label_mutex);
 
@@ -60,13 +58,13 @@ jump_label_sort_entries(struct jump_entry *start, struct jump_entry *stop)
 static void jump_label_update(struct static_key *key);
 
 /*
- * There are similar definitions for the !HAVE_JUMP_LABEL case in jump_label.h.
+ * There are similar definitions for the !CONFIG_JUMP_LABEL case in jump_label.h.
  * The use of 'atomic_read()' requires atomic.h and its problematic for some
  * kernel headers such as kernel.h and others. Since static_key_count() is not
- * used in the branch statements as it is for the !HAVE_JUMP_LABEL case its ok
+ * used in the branch statements as it is for the !CONFIG_JUMP_LABEL case its ok
  * to have it be a function here. Similarly, for 'static_key_enable()' and
  * 'static_key_disable()', which require bug.h. This should allow jump_label.h
- * to be included from most/all places for HAVE_JUMP_LABEL.
+ * to be included from most/all places for CONFIG_JUMP_LABEL.
  */
 int static_key_count(struct static_key *key)
 {
@@ -796,5 +794,3 @@ static __init int jump_label_test(void)
 }
 early_initcall(jump_label_test);
 #endif /* STATIC_KEYS_SELFTEST */
-
-#endif /* HAVE_JUMP_LABEL */
diff --git a/kernel/module.c b/kernel/module.c
index f797c6ace712..b8f37376856b 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3100,7 +3100,7 @@ static int find_module_sections(struct module *mod, struct load_info *info)
 					     sizeof(*mod->tracepoints_ptrs),
 					     &mod->num_tracepoints);
 #endif
-#ifdef HAVE_JUMP_LABEL
+#ifdef CONFIG_JUMP_LABEL
 	mod->jump_entries = section_objs(info, "__jump_table",
 					sizeof(*mod->jump_entries),
 					&mod->num_jump_entries);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 6138754e5030..6859ea1d5c04 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -24,7 +24,7 @@
 
 DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
 
-#if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
+#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_JUMP_LABEL)
 /*
  * Debugging: various feature bits
  *
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 141ea9ff210e..78fadf0438ea 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -73,7 +73,7 @@ static int sched_feat_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-#ifdef HAVE_JUMP_LABEL
+#ifdef CONFIG_JUMP_LABEL
 
 #define jump_label_key__true  STATIC_KEY_INIT_TRUE
 #define jump_label_key__false STATIC_KEY_INIT_FALSE
@@ -99,7 +99,7 @@ static void sched_feat_enable(int i)
 #else
 static void sched_feat_disable(int i) { };
 static void sched_feat_enable(int i) { };
-#endif /* HAVE_JUMP_LABEL */
+#endif /* CONFIG_JUMP_LABEL */
 
 static int sched_feat_set(char *cmp)
 {
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 7a1e9db617f7..4a433608ba74 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4209,7 +4209,7 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
 
 #ifdef CONFIG_CFS_BANDWIDTH
 
-#ifdef HAVE_JUMP_LABEL
+#ifdef CONFIG_JUMP_LABEL
 static struct static_key __cfs_bandwidth_used;
 
 static inline bool cfs_bandwidth_used(void)
@@ -4226,7 +4226,7 @@ void cfs_bandwidth_usage_dec(void)
 {
 	static_key_slow_dec_cpuslocked(&__cfs_bandwidth_used);
 }
-#else /* HAVE_JUMP_LABEL */
+#else /* CONFIG_JUMP_LABEL */
 static bool cfs_bandwidth_used(void)
 {
 	return true;
@@ -4234,7 +4234,7 @@ static bool cfs_bandwidth_used(void)
 
 void cfs_bandwidth_usage_inc(void) {}
 void cfs_bandwidth_usage_dec(void) {}
-#endif /* HAVE_JUMP_LABEL */
+#endif /* CONFIG_JUMP_LABEL */
 
 /*
  * default period for cfs group bandwidth.
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 4c7a837d7c14..9a7c3d08b39f 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1359,7 +1359,7 @@ enum {
 
 #undef SCHED_FEAT
 
-#if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
+#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_JUMP_LABEL)
 
 /*
  * To support run-time toggling of sched features, all the translation units
@@ -1379,7 +1379,7 @@ static __always_inline bool static_branch_##name(struct static_key *key) \
 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
 
-#else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
+#else /* !(SCHED_DEBUG && CONFIG_JUMP_LABEL) */
 
 /*
  * Each translation unit has its own copy of sysctl_sched_features to allow
@@ -1395,7 +1395,7 @@ static const_debug __maybe_unused unsigned int sysctl_sched_features =
 
 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
 
-#endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
+#endif /* SCHED_DEBUG && CONFIG_JUMP_LABEL */
 
 extern struct static_key_false sched_numa_balancing;
 extern struct static_key_false sched_schedstats;