jump label: Convert dynamic debug to use jump labels

Convert the 'dynamic debug' infrastructure to use jump labels.

Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <b77627358cea3e27d7be4386f45f66219afb8452.1284733808.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 21 insertions, 18 deletions

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 52c0da4bdd18..bef3cda44c4c 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -1,6 +1,8 @@
 #ifndef _DYNAMIC_DEBUG_H
 #define _DYNAMIC_DEBUG_H
 
+#include <linux/jump_label.h>
+
 /* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which
  * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
  * use independent hash functions, to reduce the chance of false positives.
@@ -22,8 +24,6 @@ struct _ddebug {
         const char *function;
         const char *filename;
         const char *format;
-        char primary_hash;
-        char secondary_hash;
         unsigned int lineno:24;
         /*
          * The flags field controls the behaviour at the callsite.
@@ -33,6 +33,7 @@ struct _ddebug {
 #define _DPRINTK_FLAGS_PRINT   (1<<0)  /* printk() a message using the format */
 #define _DPRINTK_FLAGS_DEFAULT 0
         unsigned int flags:8;
+        char enabled;
 } __attribute__((aligned(8)));
 
 
@@ -42,33 +43,35 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n,
 #if defined(CONFIG_DYNAMIC_DEBUG)
 extern int ddebug_remove_module(const char *mod_name);
 
-#define __dynamic_dbg_enabled(dd)  ({        \
-        int __ret = 0;                                                       \
-        if (unlikely((dynamic_debug_enabled & (1LL << DEBUG_HASH)) &&        \
-                        (dynamic_debug_enabled2 & (1LL << DEBUG_HASH2))))   \
-                                if (unlikely(dd.flags))                      \
-                                        __ret = 1;                           \
-        __ret; })
-
 #define dynamic_pr_debug(fmt, ...) do {                                 \
+        __label__ do_printk;                                            \
+        __label__ out;                                                  \
         static struct _ddebug descriptor                                \
         __used                                                          \
         __attribute__((section("__verbose"), aligned(8))) =             \
-        { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH,  \
-                DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT };        \
-        if (__dynamic_dbg_enabled(descriptor))                          \
-                printk(KERN_DEBUG pr_fmt(fmt),  ##__VA_ARGS__);         \
+        { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__,            \
+                _DPRINTK_FLAGS_DEFAULT };                               \
+        JUMP_LABEL(&descriptor.enabled, do_printk);                     \
+        goto out;                                                       \
+do_printk:                                                              \
+        printk(KERN_DEBUG pr_fmt(fmt),  ##__VA_ARGS__);                 \
+out:    ;                                                               \
         } while (0)
 
 
 #define dynamic_dev_dbg(dev, fmt, ...) do {                             \
+        __label__ do_printk;                                            \
+        __label__ out;                                                  \
         static struct _ddebug descriptor                                \
         __used                                                          \
         __attribute__((section("__verbose"), aligned(8))) =             \
-        { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH,  \
-                DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT };        \
-        if (__dynamic_dbg_enabled(descriptor))                          \
-                dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);        \
+        { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__,            \
+                _DPRINTK_FLAGS_DEFAULT };                               \
+        JUMP_LABEL(&descriptor.enabled, do_printk);                     \
+        goto out;                                                       \
+do_printk:                                                              \
+        dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);                \
+out:    ;                                                               \
         } while (0)
 
 #else