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>

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);
 

arch/x86/kernel/entry_64.S

@@ -71,15 +71,7 @@ ENTRY(ftrace_caller)
 	cmpl $0, function_trace_stop
 	jne  ftrace_stub
 
-	/* 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)
+	MCOUNT_SAVE_FRAME
 
 	movq 0x38(%rsp), %rdi
 	movq 8(%rbp), %rsi
@@ -89,14 +81,7 @@ ENTRY(ftrace_caller)
 ftrace_call:
 	call ftrace_stub
 
-	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
+	MCOUNT_RESTORE_FRAME
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 .globl ftrace_graph_call
@@ -130,15 +115,7 @@ ftrace_stub:
 	retq
 
 trace:
-	/* 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)
+	MCOUNT_SAVE_FRAME
 
 	movq 0x38(%rsp), %rdi
 	movq 8(%rbp), %rsi
@@ -146,14 +123,7 @@ trace:
 
 	call   *ftrace_trace_function
 
-	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
+	MCOUNT_RESTORE_FRAME
 
 	jmp ftrace_stub
 END(mcount)
@@ -165,14 +135,7 @@ ENTRY(ftrace_graph_caller)
 	cmpl $0, function_trace_stop
 	jne ftrace_stub
 
-	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)
+	MCOUNT_SAVE_FRAME
 
 	leaq 8(%rbp), %rdi
 	movq 0x38(%rsp), %rsi
@@ -180,14 +143,8 @@ ENTRY(ftrace_graph_caller)
 
 	call	prepare_ftrace_return
 
-	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
+	MCOUNT_RESTORE_FRAME
+
 	retq
 END(ftrace_graph_caller)