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authorRussell King <rmk+kernel@arm.linux.org.uk>2014-10-28 13:26:48 +0000
committerRussell King <rmk+kernel@arm.linux.org.uk>2014-11-21 15:25:01 +0000
commit82112379b73c937576f40c99b4d93162343af6f9 (patch)
tree52efb9d4ec5adc902753c57a4314ecabd8ba5a49 /arch/arm/kernel/entry-common.S
parent719c9d1489bad6ff26fa1f6a7e3f760935663398 (diff)
downloadlinux-82112379b73c937576f40c99b4d93162343af6f9.tar.gz
ARM: move ftrace assembly code to separate file
The ftrace assembly code doesn't need to live in entry-common.S and
be surrounded with #ifdef CONFIG_FUNCTION_TRACER.  Instead, move it
to its own file and conditionally assemble it.

Tested-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/entry-common.S')
-rw-r--r--arch/arm/kernel/entry-common.S235
1 files changed, 0 insertions, 235 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 6bb09d4abdea..f8ccc21fa032 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -109,241 +109,6 @@ ENDPROC(ret_from_fork)
 #undef CALL
 #define CALL(x) .long x
 
-#ifdef CONFIG_FUNCTION_TRACER
-/*
- * When compiling with -pg, gcc inserts a call to the mcount routine at the
- * start of every function.  In mcount, apart from the function's address (in
- * lr), we need to get hold of the function's caller's address.
- *
- * Older GCCs (pre-4.4) inserted a call to a routine called mcount like this:
- *
- *	bl	mcount
- *
- * These versions have the limitation that in order for the mcount routine to
- * be able to determine the function's caller's address, an APCS-style frame
- * pointer (which is set up with something like the code below) is required.
- *
- *	mov     ip, sp
- *	push    {fp, ip, lr, pc}
- *	sub     fp, ip, #4
- *
- * With EABI, these frame pointers are not available unless -mapcs-frame is
- * specified, and if building as Thumb-2, not even then.
- *
- * Newer GCCs (4.4+) solve this problem by introducing a new version of mcount,
- * with call sites like:
- *
- *	push	{lr}
- *	bl	__gnu_mcount_nc
- *
- * With these compilers, frame pointers are not necessary.
- *
- * mcount can be thought of as a function called in the middle of a subroutine
- * call.  As such, it needs to be transparent for both the caller and the
- * callee: the original lr needs to be restored when leaving mcount, and no
- * registers should be clobbered.  (In the __gnu_mcount_nc implementation, we
- * clobber the ip register.  This is OK because the ARM calling convention
- * allows it to be clobbered in subroutines and doesn't use it to hold
- * parameters.)
- *
- * When using dynamic ftrace, we patch out the mcount call by a "mov r0, r0"
- * for the mcount case, and a "pop {lr}" for the __gnu_mcount_nc case (see
- * arch/arm/kernel/ftrace.c).
- */
-
-#ifndef CONFIG_OLD_MCOUNT
-#if (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 4))
-#error Ftrace requires CONFIG_FRAME_POINTER=y with GCC older than 4.4.0.
-#endif
-#endif
-
-.macro mcount_adjust_addr rd, rn
-	bic	\rd, \rn, #1		@ clear the Thumb bit if present
-	sub	\rd, \rd, #MCOUNT_INSN_SIZE
-.endm
-
-.macro __mcount suffix
-	mcount_enter
-	ldr	r0, =ftrace_trace_function
-	ldr	r2, [r0]
-	adr	r0, .Lftrace_stub
-	cmp	r0, r2
-	bne	1f
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-	ldr     r1, =ftrace_graph_return
-	ldr     r2, [r1]
-	cmp     r0, r2
-	bne     ftrace_graph_caller\suffix
-
-	ldr     r1, =ftrace_graph_entry
-	ldr     r2, [r1]
-	ldr     r0, =ftrace_graph_entry_stub
-	cmp     r0, r2
-	bne     ftrace_graph_caller\suffix
-#endif
-
-	mcount_exit
-
-1: 	mcount_get_lr	r1			@ lr of instrumented func
-	mcount_adjust_addr	r0, lr		@ instrumented function
-	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
-	mcount_adjust_addr	r0, lr		@ instrumented function
-
-	.globl ftrace_call\suffix
-ftrace_call\suffix:
-	bl	ftrace_stub
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-	.globl ftrace_graph_call\suffix
-ftrace_graph_call\suffix:
-	mov	r0, r0
-#endif
-
-	mcount_exit
-.endm
-
-.macro __ftrace_graph_caller
-	sub	r0, fp, #4		@ &lr of instrumented routine (&parent)
-#ifdef CONFIG_DYNAMIC_FTRACE
-	@ called from __ftrace_caller, saved in mcount_enter
-	ldr	r1, [sp, #16]		@ instrumented routine (func)
-	mcount_adjust_addr	r1, r1
-#else
-	@ called from __mcount, untouched in lr
-	mcount_adjust_addr	r1, lr	@ instrumented routine (func)
-#endif
-	mov	r2, fp			@ frame pointer
-	bl	prepare_ftrace_return
-	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)
-	__ftrace_caller _old
-ENDPROC(ftrace_caller_old)
-#endif
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-ENTRY(ftrace_graph_caller_old)
-	__ftrace_graph_caller
-ENDPROC(ftrace_graph_caller_old)
-#endif
-
-.purgem mcount_enter
-.purgem mcount_get_lr
-.purgem mcount_exit
-#endif
-
-/*
- * __gnu_mcount_nc
- */
-
-.macro mcount_enter
-/*
- * This pad compensates for the push {lr} at the call site.  Note that we are
- * unable to unwind through a function which does not otherwise save its lr.
- */
- UNWIND(.pad	#4)
-	stmdb	sp!, {r0-r3, lr}
- UNWIND(.save	{r0-r3, lr})
-.endm
-
-.macro mcount_get_lr reg
-	ldr	\reg, [sp, #20]
-.endm
-
-.macro mcount_exit
-	ldmia	sp!, {r0-r3, ip, lr}
-	ret	ip
-.endm
-
-ENTRY(__gnu_mcount_nc)
-UNWIND(.fnstart)
-#ifdef CONFIG_DYNAMIC_FTRACE
-	mov	ip, lr
-	ldmia	sp!, {lr}
-	ret	ip
-#else
-	__mcount
-#endif
-UNWIND(.fnend)
-ENDPROC(__gnu_mcount_nc)
-
-#ifdef CONFIG_DYNAMIC_FTRACE
-ENTRY(ftrace_caller)
-UNWIND(.fnstart)
-	__ftrace_caller
-UNWIND(.fnend)
-ENDPROC(ftrace_caller)
-#endif
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-ENTRY(ftrace_graph_caller)
-UNWIND(.fnstart)
-	__ftrace_graph_caller
-UNWIND(.fnend)
-ENDPROC(ftrace_graph_caller)
-#endif
-
-.purgem mcount_enter
-.purgem mcount_get_lr
-.purgem mcount_exit
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-	.globl return_to_handler
-return_to_handler:
-	stmdb	sp!, {r0-r3}
-	mov	r0, fp			@ frame pointer
-	bl	ftrace_return_to_handler
-	mov	lr, r0			@ r0 has real ret addr
-	ldmia	sp!, {r0-r3}
-	ret	lr
-#endif
-
-ENTRY(ftrace_stub)
-.Lftrace_stub:
-	ret	lr
-ENDPROC(ftrace_stub)
-
-#endif /* CONFIG_FUNCTION_TRACER */
-
 /*=============================================================================
  * SWI handler
  *-----------------------------------------------------------------------------