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