ftrace: core support for ARM
Core ftrace support for the ARM architecture, which includes support
for dynamic function tracing.
Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 597ed00..8f79a47 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -99,6 +99,53 @@
#undef CALL
#define CALL(x) .long x
+#ifdef CONFIG_FTRACE
+#ifdef CONFIG_DYNAMIC_FTRACE
+ENTRY(mcount)
+ stmdb sp!, {r0-r3, lr}
+ mov r0, lr
+
+ .globl mcount_call
+mcount_call:
+ bl ftrace_stub
+ ldmia sp!, {r0-r3, pc}
+
+ENTRY(ftrace_caller)
+ stmdb sp!, {r0-r3, lr}
+ ldr r1, [fp, #-4]
+ mov r0, lr
+
+ .globl ftrace_call
+ftrace_call:
+ bl ftrace_stub
+ ldmia sp!, {r0-r3, pc}
+
+#else
+
+ENTRY(mcount)
+ stmdb sp!, {r0-r3, lr}
+ ldr r0, =ftrace_trace_function
+ ldr r2, [r0]
+ adr r0, ftrace_stub
+ cmp r0, r2
+ bne trace
+ ldmia sp!, {r0-r3, pc}
+
+trace:
+ ldr r1, [fp, #-4]
+ mov r0, lr
+ mov lr, pc
+ mov pc, r2
+ ldmia sp!, {r0-r3, pc}
+
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+ .globl ftrace_stub
+ftrace_stub:
+ mov pc, lr
+
+#endif /* CONFIG_FTRACE */
+
/*=============================================================================
* SWI handler
*-----------------------------------------------------------------------------