1/* 2 * Copyright IBM Corp. 2008, 2009 3 * 4 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>, 5 * 6 */ 7 8#include <linux/linkage.h> 9#include <asm/asm-offsets.h> 10#include <asm/ftrace.h> 11 12 .section .kprobes.text, "ax" 13 14ENTRY(ftrace_stub) 15 br %r14 16 17ENTRY(_mcount) 18#ifdef CONFIG_DYNAMIC_FTRACE 19 br %r14 20 21ENTRY(ftrace_caller) 22#endif 23 stm %r2,%r5,16(%r15) 24 bras %r1,1f 250: .long ftrace_trace_function 261: st %r14,56(%r15) 27 lr %r0,%r15 28 ahi %r15,-96 29 l %r3,100(%r15) 30 la %r2,0(%r14) 31 st %r0,__SF_BACKCHAIN(%r15) 32 la %r3,0(%r3) 33 ahi %r2,-MCOUNT_INSN_SIZE 34 l %r14,0b-0b(%r1) 35 l %r14,0(%r14) 36 basr %r14,%r14 37#ifdef CONFIG_FUNCTION_GRAPH_TRACER 38 l %r2,100(%r15) 39 l %r3,152(%r15) 40ENTRY(ftrace_graph_caller) 41# The bras instruction gets runtime patched to call prepare_ftrace_return. 42# See ftrace_enable_ftrace_graph_caller. The patched instruction is: 43# bras %r14,prepare_ftrace_return 44 bras %r14,0f 450: st %r2,100(%r15) 46#endif 47 ahi %r15,96 48 l %r14,56(%r15) 49 lm %r2,%r5,16(%r15) 50 br %r14 51 52#ifdef CONFIG_FUNCTION_GRAPH_TRACER 53 54ENTRY(return_to_handler) 55 stm %r2,%r5,16(%r15) 56 st %r14,56(%r15) 57 lr %r0,%r15 58 ahi %r15,-96 59 st %r0,__SF_BACKCHAIN(%r15) 60 bras %r1,0f 61 .long ftrace_return_to_handler 620: l %r2,0b-0b(%r1) 63 basr %r14,%r2 64 lr %r14,%r2 65 ahi %r15,96 66 lm %r2,%r5,16(%r15) 67 br %r14 68 69#endif 70