arch/s390/include/asm/ftrace.h

   1 #ifndef _ASM_S390_FTRACE_H
   2 #define _ASM_S390_FTRACE_H
   3
   4 #define ARCH_SUPPORTS_FTRACE_OPS 1
   5
   6 #ifdef CC_USING_HOTPATCH
   7 #define MCOUNT_INSN_SIZE        6
   8 #else
   9 #define MCOUNT_INSN_SIZE        24
  10 #define MCOUNT_RETURN_FIXUP     18
  11 #endif
  12
  13 #ifndef __ASSEMBLY__
  14
  15 unsigned long return_address(int depth);
  16
  17 #define ftrace_return_address(n) return_address(n)
  18
  19 void _mcount(void);
  20 void ftrace_caller(void);
  21
  22 extern char ftrace_graph_caller_end;
  23 extern unsigned long ftrace_plt;
  24
  25 struct dyn_arch_ftrace { };
  26
  27 #define MCOUNT_ADDR ((unsigned long)_mcount)
  28 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
  29
  30 #define KPROBE_ON_FTRACE_NOP    0
  31 #define KPROBE_ON_FTRACE_CALL   1
  32
  33 static inline unsigned long ftrace_call_adjust(unsigned long addr)
  34 {
  35         return addr;
  36 }
  37
  38 struct ftrace_insn {
  39         u16 opc;
  40         s32 disp;
  41 } __packed;
  42
  43 static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn)
  44 {
  45 #ifdef CONFIG_FUNCTION_TRACER
  46 #ifdef CC_USING_HOTPATCH
  47         /* brcl 0,0 */
  48         insn->opc = 0xc004;
  49         insn->disp = 0;
  50 #else
  51         /* jg .+24 */
  52         insn->opc = 0xc0f4;
  53         insn->disp = MCOUNT_INSN_SIZE / 2;
  54 #endif
  55 #endif
  56 }
  57
  58 static inline int is_ftrace_nop(struct ftrace_insn *insn)
  59 {
  60 #ifdef CONFIG_FUNCTION_TRACER
  61 #ifdef CC_USING_HOTPATCH
  62         if (insn->disp == 0)
  63                 return 1;
  64 #else
  65         if (insn->disp == MCOUNT_INSN_SIZE / 2)
  66                 return 1;
  67 #endif
  68 #endif
  69         return 0;
  70 }
  71
  72 static inline void ftrace_generate_call_insn(struct ftrace_insn *insn,
  73                                              unsigned long ip)
  74 {
  75 #ifdef CONFIG_FUNCTION_TRACER
  76         unsigned long target;
  77
  78         /* brasl r0,ftrace_caller */
  79         target = is_module_addr((void *) ip) ? ftrace_plt : FTRACE_ADDR;
  80         insn->opc = 0xc005;
  81         insn->disp = (target - ip) / 2;
  82 #endif
  83 }
  84
  85 #endif /* __ASSEMBLY__ */
  86 #endif /* _ASM_S390_FTRACE_H */