Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 102 insertions, 42 deletions

diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
index f7c69580fea..c513a40510f 100644
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -9,15 +9,15 @@
  *
  * Jump labels provide an interface to generate dynamic branches using
  * self-modifying code. Assuming toolchain and architecture support the result
- * of a "if (static_branch(&key))" statement is a unconditional branch (which
+ * of a "if (static_key_false(&key))" statement is a unconditional branch (which
  * defaults to false - and the true block is placed out of line).
  *
- * However at runtime we can change the 'static' branch target using
- * jump_label_{inc,dec}(). These function as a 'reference' count on the key
+ * However at runtime we can change the branch target using
+ * static_key_slow_{inc,dec}(). These function as a 'reference' count on the key
  * object and for as long as there are references all branches referring to
  * that particular key will point to the (out of line) true block.
  *
- * Since this relies on modifying code the jump_label_{inc,dec}() functions
+ * Since this relies on modifying code the static_key_slow_{inc,dec}() functions
  * must be considered absolute slow paths (machine wide synchronization etc.).
  * OTOH, since the affected branches are unconditional their runtime overhead
  * will be absolutely minimal, esp. in the default (off) case where the total
@@ -26,12 +26,26 @@
  *
  * When the control is directly exposed to userspace it is prudent to delay the
  * decrement to avoid high frequency code modifications which can (and do)
- * cause significant performance degradation. Struct jump_label_key_deferred and
- * jump_label_dec_deferred() provide for this.
+ * cause significant performance degradation. Struct static_key_deferred and
+ * static_key_slow_dec_deferred() provide for this.
  *
  * Lacking toolchain and or architecture support, it falls back to a simple
  * conditional branch.
- */
+ *
+ * struct static_key my_key = STATIC_KEY_INIT_TRUE;
+ *
+ *   if (static_key_true(&my_key)) {
+ *   }
+ *
+ * will result in the true case being in-line and starts the key with a single
+ * reference. Mixing static_key_true() and static_key_false() on the same key is not
+ * allowed.
+ *
+ * Not initializing the key (static data is initialized to 0s anyway) is the
+ * same as using STATIC_KEY_INIT_FALSE and static_key_false() is
+ * equivalent with static_branch().
+ *
+*/
 
 #include <linux/types.h>
 #include <linux/compiler.h>
@@ -39,16 +53,17 @@
 
 #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
 
-struct jump_label_key {
+struct static_key {
 	atomic_t enabled;
+/* Set lsb bit to 1 if branch is default true, 0 ot */
 	struct jump_entry *entries;
 #ifdef CONFIG_MODULES
-	struct jump_label_mod *next;
+	struct static_key_mod *next;
 #endif
 };
 
-struct jump_label_key_deferred {
-	struct jump_label_key key;
+struct static_key_deferred {
+	struct static_key key;
 	unsigned long timeout;
 	struct delayed_work work;
 };
@@ -66,13 +81,34 @@ struct module;
 
 #ifdef HAVE_JUMP_LABEL
 
-#ifdef CONFIG_MODULES
-#define JUMP_LABEL_INIT {ATOMIC_INIT(0), NULL, NULL}
-#else
-#define JUMP_LABEL_INIT {ATOMIC_INIT(0), NULL}
-#endif
+#define JUMP_LABEL_TRUE_BRANCH 1UL
+
+static
+inline struct jump_entry *jump_label_get_entries(struct static_key *key)
+{
+	return (struct jump_entry *)((unsigned long)key->entries
+						& ~JUMP_LABEL_TRUE_BRANCH);
+}
+
+static inline bool jump_label_get_branch_default(struct static_key *key)
+{
+	if ((unsigned long)key->entries & JUMP_LABEL_TRUE_BRANCH)
+		return true;
+	return false;
+}
+
+static __always_inline bool static_key_false(struct static_key *key)
+{
+	return arch_static_branch(key);
+}
+
+static __always_inline bool static_key_true(struct static_key *key)
+{
+	return !static_key_false(key);
+}
 
-static __always_inline bool static_branch(struct jump_label_key *key)
+/* Deprecated. Please use 'static_key_false() instead. */
+static __always_inline bool static_branch(struct static_key *key)
 {
 	return arch_static_branch(key);
 }
@@ -88,21 +124,23 @@ extern void arch_jump_label_transform(struct jump_entry *entry,
 extern void arch_jump_label_transform_static(struct jump_entry *entry,
 					     enum jump_label_type type);
 extern int jump_label_text_reserved(void *start, void *end);
-extern void jump_label_inc(struct jump_label_key *key);
-extern void jump_label_dec(struct jump_label_key *key);
-extern void jump_label_dec_deferred(struct jump_label_key_deferred *key);
-extern bool jump_label_enabled(struct jump_label_key *key);
+extern void static_key_slow_inc(struct static_key *key);
+extern void static_key_slow_dec(struct static_key *key);
+extern void static_key_slow_dec_deferred(struct static_key_deferred *key);
 extern void jump_label_apply_nops(struct module *mod);
-extern void jump_label_rate_limit(struct jump_label_key_deferred *key,
-		unsigned long rl);
+extern void
+jump_label_rate_limit(struct static_key_deferred *key, unsigned long rl);
+
+#define STATIC_KEY_INIT_TRUE ((struct static_key) \
+	{ .enabled = ATOMIC_INIT(1), .entries = (void *)1 })
+#define STATIC_KEY_INIT_FALSE ((struct static_key) \
+	{ .enabled = ATOMIC_INIT(0), .entries = (void *)0 })
 
 #else  /* !HAVE_JUMP_LABEL */
 
 #include <linux/atomic.h>
 
-#define JUMP_LABEL_INIT {ATOMIC_INIT(0)}
-
-struct jump_label_key {
+struct static_key {
 	atomic_t enabled;
 };
 
@@ -110,30 +148,45 @@ static __always_inline void jump_label_init(void)
 {
 }
 
-struct jump_label_key_deferred {
-	struct jump_label_key  key;
+struct static_key_deferred {
+	struct static_key  key;
 };
 
-static __always_inline bool static_branch(struct jump_label_key *key)
+static __always_inline bool static_key_false(struct static_key *key)
 {
-	if (unlikely(atomic_read(&key->enabled)))
+	if (unlikely(atomic_read(&key->enabled)) > 0)
 		return true;
 	return false;
 }
 
-static inline void jump_label_inc(struct jump_label_key *key)
+static __always_inline bool static_key_true(struct static_key *key)
+{
+	if (likely(atomic_read(&key->enabled)) > 0)
+		return true;
+	return false;
+}
+
+/* Deprecated. Please use 'static_key_false() instead. */
+static __always_inline bool static_branch(struct static_key *key)
+{
+	if (unlikely(atomic_read(&key->enabled)) > 0)
+		return true;
+	return false;
+}
+
+static inline void static_key_slow_inc(struct static_key *key)
 {
 	atomic_inc(&key->enabled);
 }
 
-static inline void jump_label_dec(struct jump_label_key *key)
+static inline void static_key_slow_dec(struct static_key *key)
 {
 	atomic_dec(&key->enabled);
 }
 
-static inline void jump_label_dec_deferred(struct jump_label_key_deferred *key)
+static inline void static_key_slow_dec_deferred(struct static_key_deferred *key)
 {
-	jump_label_dec(&key->key);
+	static_key_slow_dec(&key->key);
 }
 
 static inline int jump_label_text_reserved(void *start, void *end)
@@ -144,23 +197,30 @@ static inline int jump_label_text_reserved(void *start, void *end)
 static inline void jump_label_lock(void) {}
 static inline void jump_label_unlock(void) {}
 
-static inline bool jump_label_enabled(struct jump_label_key *key)
-{
-	return !!atomic_read(&key->enabled);
-}
-
 static inline int jump_label_apply_nops(struct module *mod)
 {
 	return 0;
 }
 
-static inline void jump_label_rate_limit(struct jump_label_key_deferred *key,
+static inline void
+jump_label_rate_limit(struct static_key_deferred *key,
 		unsigned long rl)
 {
 }
+
+#define STATIC_KEY_INIT_TRUE ((struct static_key) \
+		{ .enabled = ATOMIC_INIT(1) })
+#define STATIC_KEY_INIT_FALSE ((struct static_key) \
+		{ .enabled = ATOMIC_INIT(0) })
+
 #endif	/* HAVE_JUMP_LABEL */
 
-#define jump_label_key_enabled	((struct jump_label_key){ .enabled = ATOMIC_INIT(1), })
-#define jump_label_key_disabled	((struct jump_label_key){ .enabled = ATOMIC_INIT(0), })
+#define STATIC_KEY_INIT STATIC_KEY_INIT_FALSE
+#define jump_label_enabled static_key_enabled
+
+static inline bool static_key_enabled(struct static_key *key)
+{
+	return (atomic_read(&key->enabled) > 0);
+}
 
 #endif	/* _LINUX_JUMP_LABEL_H */