| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* |
| * Copyright (C) 2022 Loongson Technology Corporation Limited |
| */ |
| |
| #include <asm/ftrace.h> |
| #include <asm/regdef.h> |
| #include <asm/stackframe.h> |
| |
| .text |
| /* |
| * Due to -fpatchable-function-entry=2: the compiler inserted 2 NOPs before the |
| * regular C function prologue. When PC arrived here, the last 2 instructions |
| * are as follows: |
| * move t0, ra |
| * bl callsite (for modules, callsite is a tramplione) |
| * |
| * modules trampoline is as follows: |
| * lu12i.w t1, callsite[31:12] |
| * lu32i.d t1, callsite[51:32] |
| * lu52i.d t1, t1, callsite[63:52] |
| * jirl zero, t1, callsite[11:0] >> 2 |
| * |
| * See arch/loongarch/kernel/ftrace_dyn.c for details. Here, pay attention to |
| * that the T series regs are available and safe because each C functions |
| * follows the LoongArch's psABI as well. |
| */ |
| |
| .macro ftrace_regs_entry allregs=0 |
| PTR_ADDI sp, sp, -PT_SIZE |
| PTR_S t0, sp, PT_R1 /* Save parent ra at PT_R1(RA) */ |
| PTR_S a0, sp, PT_R4 |
| PTR_S a1, sp, PT_R5 |
| PTR_S a2, sp, PT_R6 |
| PTR_S a3, sp, PT_R7 |
| PTR_S a4, sp, PT_R8 |
| PTR_S a5, sp, PT_R9 |
| PTR_S a6, sp, PT_R10 |
| PTR_S a7, sp, PT_R11 |
| PTR_S fp, sp, PT_R22 |
| .if \allregs |
| PTR_S tp, sp, PT_R2 |
| PTR_S t0, sp, PT_R12 |
| PTR_S t2, sp, PT_R14 |
| PTR_S t3, sp, PT_R15 |
| PTR_S t4, sp, PT_R16 |
| PTR_S t5, sp, PT_R17 |
| PTR_S t6, sp, PT_R18 |
| PTR_S t7, sp, PT_R19 |
| PTR_S t8, sp, PT_R20 |
| PTR_S u0, sp, PT_R21 |
| PTR_S s0, sp, PT_R23 |
| PTR_S s1, sp, PT_R24 |
| PTR_S s2, sp, PT_R25 |
| PTR_S s3, sp, PT_R26 |
| PTR_S s4, sp, PT_R27 |
| PTR_S s5, sp, PT_R28 |
| PTR_S s6, sp, PT_R29 |
| PTR_S s7, sp, PT_R30 |
| PTR_S s8, sp, PT_R31 |
| /* Clear it for later use as a flag sometimes. */ |
| PTR_S zero, sp, PT_R0 |
| .endif |
| PTR_S ra, sp, PT_ERA /* Save trace function ra at PT_ERA */ |
| move t1, zero |
| PTR_S t1, sp, PT_R13 |
| PTR_ADDI t8, sp, PT_SIZE |
| PTR_S t8, sp, PT_R3 |
| .endm |
| |
| SYM_FUNC_START(ftrace_stub) |
| jr ra |
| SYM_FUNC_END(ftrace_stub) |
| |
| SYM_CODE_START(ftrace_common) |
| UNWIND_HINT_UNDEFINED |
| PTR_ADDI a0, ra, -8 /* arg0: ip */ |
| move a1, t0 /* arg1: parent_ip */ |
| la.pcrel t1, function_trace_op |
| PTR_L a2, t1, 0 /* arg2: op */ |
| move a3, sp /* arg3: regs */ |
| |
| SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL) |
| bl ftrace_stub |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL) |
| nop /* b ftrace_graph_caller */ |
| #endif |
| |
| /* |
| * As we didn't use S series regs in this assmembly code and all calls |
| * are C function which will save S series regs by themselves, there is |
| * no need to restore S series regs. The T series is available and safe |
| * at the callsite, so there is no need to restore the T series regs. |
| */ |
| ftrace_common_return: |
| PTR_L ra, sp, PT_R1 |
| PTR_L a0, sp, PT_R4 |
| PTR_L a1, sp, PT_R5 |
| PTR_L a2, sp, PT_R6 |
| PTR_L a3, sp, PT_R7 |
| PTR_L a4, sp, PT_R8 |
| PTR_L a5, sp, PT_R9 |
| PTR_L a6, sp, PT_R10 |
| PTR_L a7, sp, PT_R11 |
| PTR_L fp, sp, PT_R22 |
| PTR_L t0, sp, PT_ERA |
| PTR_L t1, sp, PT_R13 |
| PTR_ADDI sp, sp, PT_SIZE |
| bnez t1, .Ldirect |
| jr t0 |
| .Ldirect: |
| jr t1 |
| SYM_CODE_END(ftrace_common) |
| |
| SYM_CODE_START(ftrace_caller) |
| UNWIND_HINT_UNDEFINED |
| ftrace_regs_entry allregs=0 |
| b ftrace_common |
| SYM_CODE_END(ftrace_caller) |
| |
| #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
| SYM_CODE_START(ftrace_regs_caller) |
| UNWIND_HINT_UNDEFINED |
| ftrace_regs_entry allregs=1 |
| b ftrace_common |
| SYM_CODE_END(ftrace_regs_caller) |
| #endif |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| SYM_CODE_START(ftrace_graph_caller) |
| UNWIND_HINT_UNDEFINED |
| PTR_L a0, sp, PT_ERA |
| PTR_ADDI a0, a0, -8 /* arg0: self_addr */ |
| PTR_ADDI a1, sp, PT_R1 /* arg1: parent */ |
| bl prepare_ftrace_return |
| b ftrace_common_return |
| SYM_CODE_END(ftrace_graph_caller) |
| |
| SYM_CODE_START(return_to_handler) |
| UNWIND_HINT_UNDEFINED |
| /* Save return value regs */ |
| PTR_ADDI sp, sp, -FGRET_REGS_SIZE |
| PTR_S a0, sp, FGRET_REGS_A0 |
| PTR_S a1, sp, FGRET_REGS_A1 |
| PTR_S zero, sp, FGRET_REGS_FP |
| |
| move a0, sp |
| bl ftrace_return_to_handler |
| move ra, a0 |
| |
| /* Restore return value regs */ |
| PTR_L a0, sp, FGRET_REGS_A0 |
| PTR_L a1, sp, FGRET_REGS_A1 |
| PTR_ADDI sp, sp, FGRET_REGS_SIZE |
| |
| jr ra |
| SYM_CODE_END(return_to_handler) |
| #endif |
| |
| #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
| SYM_CODE_START(ftrace_stub_direct_tramp) |
| UNWIND_HINT_UNDEFINED |
| jr t0 |
| SYM_CODE_END(ftrace_stub_direct_tramp) |
| #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |
