2 files changed, 61 insertions, 6 deletions

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 4f1bbc68cd1b..546d68057e3b 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -1,6 +1,10 @@
 #ifndef _DYNAMIC_DEBUG_H
 #define _DYNAMIC_DEBUG_H
 
+#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
+#include <linux/jump_label.h>
+#endif
+
 /*
  * An instance of this structure is created in a special
  * ELF section at every dynamic debug callsite.  At runtime,
@@ -33,6 +37,12 @@ struct _ddebug {
 #define _DPRINTK_FLAGS_DEFAULT 0
 #endif
         unsigned int flags:8;
+#ifdef HAVE_JUMP_LABEL
+        union {
+                struct static_key_true dd_key_true;
+                struct static_key_false dd_key_false;
+        } key;
+#endif
 } __attribute__((aligned(8)));
 
 
@@ -60,7 +70,7 @@ void __dynamic_netdev_dbg(struct _ddebug *descriptor,
                           const struct net_device *dev,
                           const char *fmt, ...);
 
-#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)                \
+#define DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, key, init) \
         static struct _ddebug  __aligned(8)                     \
         __attribute__((section("__verbose"))) name = {          \
                 .modname = KBUILD_MODNAME,                      \
@@ -68,13 +78,51 @@ void __dynamic_netdev_dbg(struct _ddebug *descriptor,
                 .filename = __FILE__,                           \
                 .format = (fmt),                                \
                 .lineno = __LINE__,                             \
-                .flags =  _DPRINTK_FLAGS_DEFAULT,               \
+                .flags = _DPRINTK_FLAGS_DEFAULT,                \
+                dd_key_init(key, init)                          \
         }
 
+#ifdef HAVE_JUMP_LABEL
+
+#define dd_key_init(key, init) key = (init)
+
+#ifdef DEBUG
+#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
+        DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, .key.dd_key_true, \
+                                          (STATIC_KEY_TRUE_INIT))
+
+#define DYNAMIC_DEBUG_BRANCH(descriptor) \
+        static_branch_likely(&descriptor.key.dd_key_true)
+#else
+#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
+        DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, .key.dd_key_false, \
+                                          (STATIC_KEY_FALSE_INIT))
+
+#define DYNAMIC_DEBUG_BRANCH(descriptor) \
+        static_branch_unlikely(&descriptor.key.dd_key_false)
+#endif
+
+#else
+
+#define dd_key_init(key, init)
+
+#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
+        DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, 0, 0)
+
+#ifdef DEBUG
+#define DYNAMIC_DEBUG_BRANCH(descriptor) \
+        likely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
+#else
+#define DYNAMIC_DEBUG_BRANCH(descriptor) \
+        unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
+#endif
+
+#endif
+
 #define dynamic_pr_debug(fmt, ...)                              \
 do {                                                            \
         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         \
-        if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  \
+        if (DYNAMIC_DEBUG_BRANCH(descriptor))                   \
                 __dynamic_pr_debug(&descriptor, pr_fmt(fmt),    \
                                    ##__VA_ARGS__);              \
 } while (0)
@@ -82,7 +130,7 @@ do {								\
 #define dynamic_dev_dbg(dev, fmt, ...)                          \
 do {                                                            \
         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         \
-        if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  \
+        if (DYNAMIC_DEBUG_BRANCH(descriptor))                   \
                 __dynamic_dev_dbg(&descriptor, dev, fmt,        \
                                   ##__VA_ARGS__);               \
 } while (0)
@@ -90,7 +138,7 @@ do {								\
 #define dynamic_netdev_dbg(dev, fmt, ...)                       \
 do {                                                            \
         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);         \
-        if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  \
+        if (DYNAMIC_DEBUG_BRANCH(descriptor))                   \
                 __dynamic_netdev_dbg(&descriptor, dev, fmt,     \
                                      ##__VA_ARGS__);            \
 } while (0)
@@ -100,7 +148,7 @@ do {								\
 do {                                                            \
         DEFINE_DYNAMIC_DEBUG_METADATA(descriptor,               \
                 __builtin_constant_p(prefix_str) ? prefix_str : "hexdump");\
-        if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))  \
+        if (DYNAMIC_DEBUG_BRANCH(descriptor))                   \
                 print_hex_dump(KERN_DEBUG, prefix_str,          \
                                prefix_type, rowsize, groupsize, \
                                buf, len, ascii);                \
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index fe42b6ec3f0c..da796e2dc4f5 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -188,6 +188,13 @@ static int ddebug_change(const struct ddebug_query *query,
                         newflags = (dp->flags & mask) | flags;
                         if (newflags == dp->flags)
                                 continue;
+#ifdef HAVE_JUMP_LABEL
+                        if (dp->flags & _DPRINTK_FLAGS_PRINT) {
+                                if (!(flags & _DPRINTK_FLAGS_PRINT))
+                                        static_branch_disable(&dp->key.dd_key_true);
+                        } else if (flags & _DPRINTK_FLAGS_PRINT)
+                                static_branch_enable(&dp->key.dd_key_true);
+#endif
                         dp->flags = newflags;
                         vpr_info("changed %s:%d [%s]%s =%s\n",
                                  trim_prefix(dp->filename), dp->lineno,