MIPS: Tracing: Make ftrace for MIPS work without -fno-omit-frame-pointer

When remove the -fno-omit-frame-pointer, gcc will not save the frame
pointer for us, we need to save one ourselves.

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Nicholas Mc Guire <der.herr@hofr.at>
Cc: zhangfx@lemote.com
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/679/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 57 insertions, 0 deletions

diff --git a/arch/mips/include/asm/ftrace.h b/arch/mips/include/asm/ftrace.h
index 7094a40b96d..3986cd8704f 100644
--- a/arch/mips/include/asm/ftrace.h
+++ b/arch/mips/include/asm/ftrace.h
@@ -19,6 +19,62 @@
 extern void _mcount(void);
 #define mcount _mcount
 
+#define safe_load(load, src, dst, error)                \
+do {                                                    \
+        asm volatile (                                  \
+                "1: " load " %[" STR(dst) "], 0(%[" STR(src) "])\n"\
+                "   li %[" STR(error) "], 0\n"          \
+                "2:\n"                                  \
+                                                        \
+                ".section .fixup, \"ax\"\n"             \
+                "3: li %[" STR(error) "], 1\n"          \
+                "   j 2b\n"                             \
+                ".previous\n"                           \
+                                                        \
+                ".section\t__ex_table,\"a\"\n\t"        \
+                STR(PTR) "\t1b, 3b\n\t"                 \
+                ".previous\n"                           \
+                                                        \
+                : [dst] "=&r" (dst), [error] "=r" (error)\
+                : [src] "r" (src)                       \
+                : "memory"                              \
+        );                                              \
+} while (0)
+
+#define safe_store(store, src, dst, error)      \
+do {                                            \
+        asm volatile (                          \
+                "1: " store " %[" STR(src) "], 0(%[" STR(dst) "])\n"\
+                "   li %[" STR(error) "], 0\n"  \
+                "2:\n"                          \
+                                                \
+                ".section .fixup, \"ax\"\n"     \
+                "3: li %[" STR(error) "], 1\n"  \
+                "   j 2b\n"                     \
+                ".previous\n"                   \
+                                                \
+                ".section\t__ex_table,\"a\"\n\t"\
+                STR(PTR) "\t1b, 3b\n\t"         \
+                ".previous\n"                   \
+                                                \
+                : [error] "=r" (error)          \
+                : [dst] "r" (dst), [src] "r" (src)\
+                : "memory"                      \
+        );                                      \
+} while (0)
+
+#define safe_load_code(dst, src, error) \
+        safe_load(STR(lw), src, dst, error)
+#define safe_store_code(src, dst, error) \
+        safe_store(STR(sw), src, dst, error)
+
+#define safe_load_stack(dst, src, error) \
+        safe_load(STR(PTR_L), src, dst, error)
+
+#define safe_store_stack(src, dst, error) \
+        safe_store(STR(PTR_S), src, dst, error)
+
+
 #ifdef CONFIG_DYNAMIC_FTRACE
 static inline unsigned long ftrace_call_adjust(unsigned long addr)
 {
@@ -27,6 +83,7 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
 
 struct dyn_arch_ftrace {
 };
+
 #endif /*  CONFIG_DYNAMIC_FTRACE */
 #endif /* __ASSEMBLY__ */
 #endif /* CONFIG_FUNCTION_TRACER */