| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame^] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | #ifndef _ASM_S390_FTRACE_H |
| 3 | #define _ASM_S390_FTRACE_H |
| 4 | |
| 5 | #define ARCH_SUPPORTS_FTRACE_OPS 1 |
| 6 | |
| 7 | #if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT) |
| 8 | #define MCOUNT_INSN_SIZE 6 |
| 9 | #else |
| 10 | #define MCOUNT_INSN_SIZE 24 |
| 11 | #define MCOUNT_RETURN_FIXUP 18 |
| 12 | #endif |
| 13 | |
| 14 | #ifndef __ASSEMBLY__ |
| 15 | |
| 16 | #define ftrace_return_address(n) __builtin_return_address(n) |
| 17 | |
| 18 | void _mcount(void); |
| 19 | void ftrace_caller(void); |
| 20 | |
| 21 | extern char ftrace_graph_caller_end; |
| 22 | extern unsigned long ftrace_plt; |
| 23 | |
| 24 | struct dyn_arch_ftrace { }; |
| 25 | |
| 26 | #define MCOUNT_ADDR ((unsigned long)_mcount) |
| 27 | #define FTRACE_ADDR ((unsigned long)ftrace_caller) |
| 28 | |
| 29 | #define KPROBE_ON_FTRACE_NOP 0 |
| 30 | #define KPROBE_ON_FTRACE_CALL 1 |
| 31 | |
| 32 | static inline unsigned long ftrace_call_adjust(unsigned long addr) |
| 33 | { |
| 34 | return addr; |
| 35 | } |
| 36 | |
| 37 | struct ftrace_insn { |
| 38 | u16 opc; |
| 39 | s32 disp; |
| 40 | } __packed; |
| 41 | |
| 42 | static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn) |
| 43 | { |
| 44 | #ifdef CONFIG_FUNCTION_TRACER |
| 45 | #if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT) |
| 46 | /* brcl 0,0 */ |
| 47 | insn->opc = 0xc004; |
| 48 | insn->disp = 0; |
| 49 | #else |
| 50 | /* jg .+24 */ |
| 51 | insn->opc = 0xc0f4; |
| 52 | insn->disp = MCOUNT_INSN_SIZE / 2; |
| 53 | #endif |
| 54 | #endif |
| 55 | } |
| 56 | |
| 57 | static inline int is_ftrace_nop(struct ftrace_insn *insn) |
| 58 | { |
| 59 | #ifdef CONFIG_FUNCTION_TRACER |
| 60 | #if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT) |
| 61 | if (insn->disp == 0) |
| 62 | return 1; |
| 63 | #else |
| 64 | if (insn->disp == MCOUNT_INSN_SIZE / 2) |
| 65 | return 1; |
| 66 | #endif |
| 67 | #endif |
| 68 | return 0; |
| 69 | } |
| 70 | |
| 71 | static inline void ftrace_generate_call_insn(struct ftrace_insn *insn, |
| 72 | unsigned long ip) |
| 73 | { |
| 74 | #ifdef CONFIG_FUNCTION_TRACER |
| 75 | unsigned long target; |
| 76 | |
| 77 | /* brasl r0,ftrace_caller */ |
| 78 | target = is_module_addr((void *) ip) ? ftrace_plt : FTRACE_ADDR; |
| 79 | insn->opc = 0xc005; |
| 80 | insn->disp = (target - ip) / 2; |
| 81 | #endif |
| 82 | } |
| 83 | |
| 84 | #endif /* __ASSEMBLY__ */ |
| 85 | #endif /* _ASM_S390_FTRACE_H */ |