diff options
Diffstat (limited to 'arch/loongarch/kernel/mcount_dyn.S')
| -rw-r--r-- | arch/loongarch/kernel/mcount_dyn.S | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/mcount_dyn.S b/arch/loongarch/kernel/mcount_dyn.S new file mode 100644 index 000000000000..482aa553aa2d --- /dev/null +++ b/arch/loongarch/kernel/mcount_dyn.S @@ -0,0 +1,160 @@ +/* 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) + 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) + 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) + 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) + 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) + /* 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) + jr t0 +SYM_CODE_END(ftrace_stub_direct_tramp) +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |