| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* Copyright (C) 2017 Andes Technology Corporation */ |
| |
| #include <linux/init.h> |
| #include <linux/linkage.h> |
| #include <linux/export.h> |
| #include <asm/asm.h> |
| #include <asm/csr.h> |
| #include <asm/unistd.h> |
| #include <asm/thread_info.h> |
| #include <asm/asm-offsets.h> |
| #include <asm/ftrace.h> |
| |
| .text |
| |
| #define ABI_SIZE_ON_STACK 80 |
| #define ABI_A0 0 |
| #define ABI_A1 8 |
| #define ABI_A2 16 |
| #define ABI_A3 24 |
| #define ABI_A4 32 |
| #define ABI_A5 40 |
| #define ABI_A6 48 |
| #define ABI_A7 56 |
| #define ABI_T0 64 |
| #define ABI_RA 72 |
| |
| .macro SAVE_ABI |
| addi sp, sp, -ABI_SIZE_ON_STACK |
| |
| REG_S a0, ABI_A0(sp) |
| REG_S a1, ABI_A1(sp) |
| REG_S a2, ABI_A2(sp) |
| REG_S a3, ABI_A3(sp) |
| REG_S a4, ABI_A4(sp) |
| REG_S a5, ABI_A5(sp) |
| REG_S a6, ABI_A6(sp) |
| REG_S a7, ABI_A7(sp) |
| REG_S t0, ABI_T0(sp) |
| REG_S ra, ABI_RA(sp) |
| .endm |
| |
| .macro RESTORE_ABI |
| REG_L a0, ABI_A0(sp) |
| REG_L a1, ABI_A1(sp) |
| REG_L a2, ABI_A2(sp) |
| REG_L a3, ABI_A3(sp) |
| REG_L a4, ABI_A4(sp) |
| REG_L a5, ABI_A5(sp) |
| REG_L a6, ABI_A6(sp) |
| REG_L a7, ABI_A7(sp) |
| REG_L t0, ABI_T0(sp) |
| REG_L ra, ABI_RA(sp) |
| |
| addi sp, sp, ABI_SIZE_ON_STACK |
| .endm |
| |
| /** |
| * SAVE_ABI_REGS - save regs against the ftrace_regs struct |
| * |
| * After the stack is established, |
| * |
| * 0(sp) stores the PC of the traced function which can be accessed |
| * by &(fregs)->epc in tracing function. |
| * |
| * 8(sp) stores the function return address (i.e. parent IP) that |
| * can be accessed by &(fregs)->ra in tracing function. |
| * |
| * The other regs are saved at the respective localtion and accessed |
| * by the respective ftrace_regs member. |
| * |
| * Here is the layout of stack for your reference. |
| * |
| * PT_SIZE_ON_STACK -> +++++++++ |
| * + ..... + |
| * + a0-a7 + --++++-> ftrace_caller saved |
| * + t1 + --++++-> direct tramp address |
| * + s0 + --+ // frame pointer |
| * + sp + + |
| * + ra + --+ // parent IP |
| * sp -> + epc + --+ // PC |
| * +++++++++ |
| **/ |
| .macro SAVE_ABI_REGS |
| addi sp, sp, -FREGS_SIZE_ON_STACK |
| REG_S t0, FREGS_EPC(sp) |
| REG_S x1, FREGS_RA(sp) |
| #ifdef HAVE_FUNCTION_GRAPH_FP_TEST |
| REG_S x8, FREGS_S0(sp) |
| #endif |
| REG_S x6, FREGS_T1(sp) |
| #ifdef CONFIG_CC_IS_CLANG |
| REG_S x7, FREGS_T2(sp) |
| REG_S x28, FREGS_T3(sp) |
| REG_S x29, FREGS_T4(sp) |
| REG_S x30, FREGS_T5(sp) |
| REG_S x31, FREGS_T6(sp) |
| #endif |
| // save the arguments |
| REG_S x10, FREGS_A0(sp) |
| REG_S x11, FREGS_A1(sp) |
| REG_S x12, FREGS_A2(sp) |
| REG_S x13, FREGS_A3(sp) |
| REG_S x14, FREGS_A4(sp) |
| REG_S x15, FREGS_A5(sp) |
| REG_S x16, FREGS_A6(sp) |
| REG_S x17, FREGS_A7(sp) |
| mv a0, sp |
| addi a0, a0, FREGS_SIZE_ON_STACK |
| REG_S a0, FREGS_SP(sp) // Put original SP on stack |
| .endm |
| |
| .macro RESTORE_ABI_REGS |
| REG_L t0, FREGS_EPC(sp) |
| REG_L x1, FREGS_RA(sp) |
| #ifdef HAVE_FUNCTION_GRAPH_FP_TEST |
| REG_L x8, FREGS_S0(sp) |
| #endif |
| REG_L x6, FREGS_T1(sp) |
| #ifdef CONFIG_CC_IS_CLANG |
| REG_L x7, FREGS_T2(sp) |
| REG_L x28, FREGS_T3(sp) |
| REG_L x29, FREGS_T4(sp) |
| REG_L x30, FREGS_T5(sp) |
| REG_L x31, FREGS_T6(sp) |
| #endif |
| // restore the arguments |
| REG_L x10, FREGS_A0(sp) |
| REG_L x11, FREGS_A1(sp) |
| REG_L x12, FREGS_A2(sp) |
| REG_L x13, FREGS_A3(sp) |
| REG_L x14, FREGS_A4(sp) |
| REG_L x15, FREGS_A5(sp) |
| REG_L x16, FREGS_A6(sp) |
| REG_L x17, FREGS_A7(sp) |
| |
| addi sp, sp, FREGS_SIZE_ON_STACK |
| .endm |
| |
| .macro PREPARE_ARGS |
| addi a0, t0, -MCOUNT_JALR_SIZE // ip (callsite's jalr insn) |
| #ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS |
| mv a1, ra // parent_ip |
| REG_L a2, -16(t0) // op |
| REG_L ra, FTRACE_OPS_FUNC(a2) // op->func |
| #else |
| la a1, function_trace_op |
| REG_L a2, 0(a1) // op |
| mv a1, ra // parent_ip |
| #endif |
| mv a3, sp // regs |
| .endm |
| |
| SYM_FUNC_START(ftrace_caller) |
| #ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS |
| /* |
| * When CALL_OPS is enabled (2 or 4) nops [8B] are placed before the |
| * function entry, these are later overwritten with the pointer to the |
| * associated struct ftrace_ops. |
| * |
| * -8: &ftrace_ops of the associated tracer function. |
| *<ftrace enable>: |
| * 0: auipc t0/ra, 0x? |
| * 4: jalr t0/ra, ?(t0/ra) |
| * |
| * -8: &ftrace_nop_ops |
| *<ftrace disable>: |
| * 0: nop |
| * 4: nop |
| * |
| * t0 is set to ip+8 after the jalr is executed at the callsite, |
| * so we find the associated op at t0-16. |
| */ |
| REG_L t1, -16(t0) // op Should be SZ_REG instead of 16 |
| |
| #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
| /* |
| * If the op has a direct call, handle it immediately without |
| * saving/restoring registers. |
| */ |
| REG_L t1, FTRACE_OPS_DIRECT_CALL(t1) |
| bnez t1, ftrace_caller_direct |
| #endif |
| #endif |
| SAVE_ABI_REGS |
| PREPARE_ARGS |
| |
| #ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS |
| jalr ra |
| #else |
| SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL) |
| REG_L ra, ftrace_call_dest |
| jalr ra, 0(ra) |
| #endif |
| RESTORE_ABI_REGS |
| #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
| bnez t1, ftrace_caller_direct |
| #endif |
| jr t0 |
| #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
| SYM_INNER_LABEL(ftrace_caller_direct, SYM_L_LOCAL) |
| jr t1 |
| #endif |
| SYM_FUNC_END(ftrace_caller) |
| |
| #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 */ |
