1 files changed, 82 insertions, 2 deletions

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 98115d9d04da..ea7c6be354b7 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -59,8 +59,88 @@ extern void __chk_io_ptr(const volatile void __iomem *);
  * specific implementations come from the above header files
  */
 
-#define likely(x)       __builtin_expect(!!(x), 1)
-#define unlikely(x)     __builtin_expect(!!(x), 0)
+struct ftrace_branch_data {
+        const char *func;
+        const char *file;
+        unsigned line;
+        union {
+                struct {
+                        unsigned long correct;
+                        unsigned long incorrect;
+                };
+                struct {
+                        unsigned long miss;
+                        unsigned long hit;
+                };
+        };
+};
+
+/*
+ * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
+ * to disable branch tracing on a per file basis.
+ */
+#if defined(CONFIG_TRACE_BRANCH_PROFILING) && !defined(DISABLE_BRANCH_PROFILING)
+void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
+
+#define likely_notrace(x)       __builtin_expect(!!(x), 1)
+#define unlikely_notrace(x)     __builtin_expect(!!(x), 0)
+
+#define __branch_check__(x, expect) ({                                  \
+                        int ______r;                                    \
+                        static struct ftrace_branch_data                \
+                                __attribute__((__aligned__(4)))         \
+                                __attribute__((section("_ftrace_annotated_branch"))) \
+                                ______f = {                             \
+                                .func = __func__,                       \
+                                .file = __FILE__,                       \
+                                .line = __LINE__,                       \
+                        };                                              \
+                        ______r = likely_notrace(x);                    \
+                        ftrace_likely_update(&______f, ______r, expect); \
+                        ______r;                                        \
+                })
+
+/*
+ * Using __builtin_constant_p(x) to ignore cases where the return
+ * value is always the same.  This idea is taken from a similar patch
+ * written by Daniel Walker.
+ */
+# ifndef likely
+#  define likely(x)     (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
+# endif
+# ifndef unlikely
+#  define unlikely(x)   (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
+# endif
+
+#ifdef CONFIG_PROFILE_ALL_BRANCHES
+/*
+ * "Define 'is'", Bill Clinton
+ * "Define 'if'", Steven Rostedt
+ */
+#define if(cond) if (__builtin_constant_p((cond)) ? !!(cond) :          \
+        ({                                                              \
+                int ______r;                                            \
+                static struct ftrace_branch_data                        \
+                        __attribute__((__aligned__(4)))                 \
+                        __attribute__((section("_ftrace_branch")))      \
+                        ______f = {                                     \
+                                .func = __func__,                       \
+                                .file = __FILE__,                       \
+                                .line = __LINE__,                       \
+                        };                                              \
+                ______r = !!(cond);                                     \
+                if (______r)                                            \
+                        ______f.hit++;                                  \
+                else                                                    \
+                        ______f.miss++;                                 \
+                ______r;                                                \
+        }))
+#endif /* CONFIG_PROFILE_ALL_BRANCHES */
+
+#else
+# define likely(x)      __builtin_expect(!!(x), 1)
+# define unlikely(x)    __builtin_expect(!!(x), 0)
+#endif
 
 /* Optimization barrier */
 #ifndef barrier