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| /* SPDX-License-Identifier: GPL-2.0 */
| /* Copyright (C) 2017 Andes Technology Corporation */
|
| #include <linux/init.h>
| #include <linux/linkage.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-generic/export.h>
| #include <asm/ftrace.h>
|
| .text
|
| .macro SAVE_ABI_STATE
| addi sp, sp, -16
| sd s0, 0(sp)
| sd ra, 8(sp)
| addi s0, sp, 16
| .endm
|
| /*
| * The call to ftrace_return_to_handler would overwrite the return
| * register if a0 was not saved.
| */
| .macro SAVE_RET_ABI_STATE
| addi sp, sp, -32
| sd s0, 16(sp)
| sd ra, 24(sp)
| sd a0, 8(sp)
| addi s0, sp, 32
| .endm
|
| .macro RESTORE_ABI_STATE
| ld ra, 8(sp)
| ld s0, 0(sp)
| addi sp, sp, 16
| .endm
|
| .macro RESTORE_RET_ABI_STATE
| ld ra, 24(sp)
| ld s0, 16(sp)
| ld a0, 8(sp)
| addi sp, sp, 32
| .endm
|
| ENTRY(ftrace_stub)
| #ifdef CONFIG_DYNAMIC_FTRACE
| .global MCOUNT_NAME
| .set MCOUNT_NAME, ftrace_stub
| #endif
| ret
| ENDPROC(ftrace_stub)
|
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER
| ENTRY(return_to_handler)
| /*
| * On implementing the frame point test, the ideal way is to compare the
| * s0 (frame pointer, if enabled) on entry and the sp (stack pointer) on return.
| * However, the psABI of variable-length-argument functions does not allow this.
| *
| * So alternatively we check the *old* frame pointer position, that is, the
| * value stored in -16(s0) on entry, and the s0 on return.
| */
| #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
| mv t6, s0
| #endif
| SAVE_RET_ABI_STATE
| #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
| mv a0, t6
| #endif
| call ftrace_return_to_handler
| mv a1, a0
| RESTORE_RET_ABI_STATE
| jalr a1
| ENDPROC(return_to_handler)
| EXPORT_SYMBOL(return_to_handler)
| #endif
|
| #ifndef CONFIG_DYNAMIC_FTRACE
| ENTRY(MCOUNT_NAME)
| la t4, ftrace_stub
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER
| la t0, ftrace_graph_return
| ld t1, 0(t0)
| bne t1, t4, do_ftrace_graph_caller
|
| la t3, ftrace_graph_entry
| ld t2, 0(t3)
| la t6, ftrace_graph_entry_stub
| bne t2, t6, do_ftrace_graph_caller
| #endif
| la t3, ftrace_trace_function
| ld t5, 0(t3)
| bne t5, t4, do_trace
| ret
|
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER
| /*
| * A pseudo representation for the function graph tracer:
| * prepare_to_return(&ra_to_caller_of_caller, ra_to_caller)
| */
| do_ftrace_graph_caller:
| addi a0, s0, -8
| mv a1, ra
| #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
| ld a2, -16(s0)
| #endif
| SAVE_ABI_STATE
| call prepare_ftrace_return
| RESTORE_ABI_STATE
| ret
| #endif
|
| /*
| * A pseudo representation for the function tracer:
| * (*ftrace_trace_function)(ra_to_caller, ra_to_caller_of_caller)
| */
| do_trace:
| ld a1, -8(s0)
| mv a0, ra
|
| SAVE_ABI_STATE
| jalr t5
| RESTORE_ABI_STATE
| ret
| ENDPROC(MCOUNT_NAME)
| #endif
| EXPORT_SYMBOL(MCOUNT_NAME)
|
|
