ARM: ftrace: use gas macros to avoid code duplication

Use assembler macros to avoid copy/pasting code between the
implementations of the two variants of the mcount call.

Signed-off-by: Rabin Vincent <rabin@rab.in>

1 files changed, 80 insertions, 66 deletions

diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 8bfa98757cd..fe1d5862b19 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -141,98 +141,112 @@ ENDPROC(ret_from_fork)
 #endif
 #endif
 
-#ifdef CONFIG_DYNAMIC_FTRACE
-ENTRY(__gnu_mcount_nc)
-        mov     ip, lr
-        ldmia   sp!, {lr}
-        mov     pc, ip
-ENDPROC(__gnu_mcount_nc)
+.macro __mcount suffix
+        mcount_enter
+        ldr     r0, =ftrace_trace_function
+        ldr     r2, [r0]
+        adr     r0, .Lftrace_stub
+        cmp     r0, r2
+        bne     1f
+        mcount_exit
 
-ENTRY(ftrace_caller)
-        stmdb   sp!, {r0-r3, lr}
-        mov     r0, lr
+1:      mcount_get_lr   r1                      @ lr of instrumented func
+        mov     r0, lr                          @ instrumented function
+        sub     r0, r0, #MCOUNT_INSN_SIZE
+        adr     lr, BSYM(2f)
+        mov     pc, r2
+2:      mcount_exit
+.endm
+
+.macro __ftrace_caller suffix
+        mcount_enter
+
+        mcount_get_lr   r1                      @ lr of instrumented func
+        mov     r0, lr                          @ instrumented function
         sub     r0, r0, #MCOUNT_INSN_SIZE
-        ldr     r1, [sp, #20]
 
-        .global ftrace_call
-ftrace_call:
+        .globl ftrace_call\suffix
+ftrace_call\suffix:
         bl      ftrace_stub
-        ldmia   sp!, {r0-r3, ip, lr}
-        mov     pc, ip
-ENDPROC(ftrace_caller)
+
+        mcount_exit
+.endm
 
 #ifdef CONFIG_OLD_MCOUNT
+/*
+ * mcount
+ */
+
+.macro mcount_enter
+        stmdb   sp!, {r0-r3, lr}
+.endm
+
+.macro mcount_get_lr reg
+        ldr     \reg, [fp, #-4]
+.endm
+
+.macro mcount_exit
+        ldr     lr, [fp, #-4]
+        ldmia   sp!, {r0-r3, pc}
+.endm
+
 ENTRY(mcount)
+#ifdef CONFIG_DYNAMIC_FTRACE
         stmdb   sp!, {lr}
         ldr     lr, [fp, #-4]
         ldmia   sp!, {pc}
+#else
+        __mcount _old
+#endif
 ENDPROC(mcount)
 
+#ifdef CONFIG_DYNAMIC_FTRACE
 ENTRY(ftrace_caller_old)
-        stmdb   sp!, {r0-r3, lr}
-        ldr     r1, [fp, #-4]
-        mov     r0, lr
-        sub     r0, r0, #MCOUNT_INSN_SIZE
-
-        .globl ftrace_call_old
-ftrace_call_old:
-        bl      ftrace_stub
-        ldr     lr, [fp, #-4]                   @ restore lr
-        ldmia   sp!, {r0-r3, pc}
+        __ftrace_caller _old
 ENDPROC(ftrace_caller_old)
 #endif
 
-#else
+.purgem mcount_enter
+.purgem mcount_get_lr
+.purgem mcount_exit
+#endif
 
-ENTRY(__gnu_mcount_nc)
+/*
+ * __gnu_mcount_nc
+ */
+
+.macro mcount_enter
         stmdb   sp!, {r0-r3, lr}
-        ldr     r0, =ftrace_trace_function
-        ldr     r2, [r0]
-        adr     r0, .Lftrace_stub
-        cmp     r0, r2
-        bne     gnu_trace
+.endm
+
+.macro mcount_get_lr reg
+        ldr     \reg, [sp, #20]
+.endm
+
+.macro mcount_exit
         ldmia   sp!, {r0-r3, ip, lr}
         mov     pc, ip
+.endm
 
-gnu_trace:
-        ldr     r1, [sp, #20]                   @ lr of instrumented routine
-        mov     r0, lr
-        sub     r0, r0, #MCOUNT_INSN_SIZE
-        adr     lr, BSYM(1f)
-        mov     pc, r2
-1:
-        ldmia   sp!, {r0-r3, ip, lr}
+ENTRY(__gnu_mcount_nc)
+#ifdef CONFIG_DYNAMIC_FTRACE
+        mov     ip, lr
+        ldmia   sp!, {lr}
         mov     pc, ip
+#else
+        __mcount
+#endif
 ENDPROC(__gnu_mcount_nc)
 
-#ifdef CONFIG_OLD_MCOUNT
-/*
- * This is under an ifdef in order to force link-time errors for people trying
- * to build with !FRAME_POINTER with a GCC which doesn't use the new-style
- * mcount.
- */
-ENTRY(mcount)
-        stmdb   sp!, {r0-r3, lr}
-        ldr     r0, =ftrace_trace_function
-        ldr     r2, [r0]
-        adr     r0, ftrace_stub
-        cmp     r0, r2
-        bne     trace
-        ldr     lr, [fp, #-4]                   @ restore lr
-        ldmia   sp!, {r0-r3, pc}
-
-trace:
-        ldr     r1, [fp, #-4]                   @ lr of instrumented routine
-        mov     r0, lr
-        sub     r0, r0, #MCOUNT_INSN_SIZE
-        mov     lr, pc
-        mov     pc, r2
-        ldr     lr, [fp, #-4]                   @ restore lr
-        ldmia   sp!, {r0-r3, pc}
-ENDPROC(mcount)
+#ifdef CONFIG_DYNAMIC_FTRACE
+ENTRY(ftrace_caller)
+        __ftrace_caller
+ENDPROC(ftrace_caller)
 #endif
 
-#endif /* CONFIG_DYNAMIC_FTRACE */
+.purgem mcount_enter
+.purgem mcount_get_lr
+.purgem mcount_exit
 
 ENTRY(ftrace_stub)
 .Lftrace_stub: