x86: entry_64 - introduce FTRACE_ frame macro v2

Impact: clean up

Itroduce MCOUNT_SAVE/RESTORE_FRAME which allow us to
save a number of lines on source level.

Also fix a comment in ftrace.h.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 28 insertions, 1 deletions

diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index 7e61b4ceb9a4..b55b4a7fbefd 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -1,6 +1,33 @@
 #ifndef _ASM_X86_FTRACE_H
 #define _ASM_X86_FTRACE_H
 
+#ifdef __ASSEMBLY__
+
+        .macro MCOUNT_SAVE_FRAME
+        /* taken from glibc */
+        subq $0x38, %rsp
+        movq %rax, (%rsp)
+        movq %rcx, 8(%rsp)
+        movq %rdx, 16(%rsp)
+        movq %rsi, 24(%rsp)
+        movq %rdi, 32(%rsp)
+        movq %r8, 40(%rsp)
+        movq %r9, 48(%rsp)
+        .endm
+
+        .macro MCOUNT_RESTORE_FRAME
+        movq 48(%rsp), %r9
+        movq 40(%rsp), %r8
+        movq 32(%rsp), %rdi
+        movq 24(%rsp), %rsi
+        movq 16(%rsp), %rdx
+        movq 8(%rsp), %rcx
+        movq (%rsp), %rax
+        addq $0x38, %rsp
+        .endm
+
+#endif
+
 #ifdef CONFIG_FUNCTION_TRACER
 #define MCOUNT_ADDR             ((long)(mcount))
 #define MCOUNT_INSN_SIZE        5 /* sizeof mcount call */
@@ -46,7 +73,7 @@ struct ftrace_ret_stack {
 /*
  * Primary handler of a function return.
  * It relays on ftrace_return_to_handler.
- * Defined in entry32.S
+ * Defined in entry_32/64.S
  */
 extern void return_to_handler(void);