linux/arch/s390/kernel/mcount.S
Martin Schwidefsky 4cc9bed034 [S390] cleanup ftrace backend functions
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05 12:47:31 +01:00

76 lines
1.3 KiB
ArmAsm

/*
* Copyright IBM Corp. 2008,2009
*
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
*
*/
#include <asm/asm-offsets.h>
.section .kprobes.text, "ax"
.globl ftrace_stub
ftrace_stub:
br %r14
.globl _mcount
_mcount:
#ifdef CONFIG_DYNAMIC_FTRACE
br %r14
.globl ftrace_caller
ftrace_caller:
#endif
stm %r2,%r5,16(%r15)
bras %r1,2f
0: .long ftrace_trace_function
1: .long function_trace_stop
2: l %r2,1b-0b(%r1)
icm %r2,0xf,0(%r2)
jnz 3f
st %r14,56(%r15)
lr %r0,%r15
ahi %r15,-96
l %r3,100(%r15)
la %r2,0(%r14)
st %r0,__SF_BACKCHAIN(%r15)
la %r3,0(%r3)
l %r14,0b-0b(%r1)
l %r14,0(%r14)
basr %r14,%r14
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
l %r2,100(%r15)
l %r3,152(%r15)
.globl ftrace_graph_caller
ftrace_graph_caller:
# The bras instruction gets runtime patched to call prepare_ftrace_return.
# See ftrace_enable_ftrace_graph_caller. The patched instruction is:
# bras %r14,prepare_ftrace_return
bras %r14,0f
0: st %r2,100(%r15)
#endif
ahi %r15,96
l %r14,56(%r15)
3: lm %r2,%r5,16(%r15)
br %r14
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
.globl return_to_handler
return_to_handler:
stm %r2,%r5,16(%r15)
st %r14,56(%r15)
lr %r0,%r15
ahi %r15,-96
st %r0,__SF_BACKCHAIN(%r15)
bras %r1,0f
.long ftrace_return_to_handler
0: l %r2,0b-0b(%r1)
basr %r14,%r2
lr %r14,%r2
ahi %r15,96
lm %r2,%r5,16(%r15)
br %r14
#endif