xref: /linux/arch/loongarch/net/bpf_timed_may_goto.S (revision caf325ab81be0bc22adf75248ecd22f52f01ad21)
1*3fbf3534SGeorge Guo/* SPDX-License-Identifier: GPL-2.0 */
2*3fbf3534SGeorge Guo/*
3*3fbf3534SGeorge Guo * Author: George Guo <guodongtai@kylinos.cn>
4*3fbf3534SGeorge Guo * Copyright (C) 2026 KylinSoft Corporation.
5*3fbf3534SGeorge Guo */
6*3fbf3534SGeorge Guo
7*3fbf3534SGeorge Guo#include <asm/asmmacro.h>
8*3fbf3534SGeorge Guo#include <asm/regdef.h>
9*3fbf3534SGeorge Guo#include <linux/export.h>
10*3fbf3534SGeorge Guo#include <linux/linkage.h>
11*3fbf3534SGeorge Guo
12*3fbf3534SGeorge GuoSYM_FUNC_START(arch_bpf_timed_may_goto)
13*3fbf3534SGeorge Guo	addi.d		sp, sp, -64
14*3fbf3534SGeorge Guo	st.d		ra, sp, 56
15*3fbf3534SGeorge Guo
16*3fbf3534SGeorge Guo	/* Save BPF registers R0 - R5 (a5, a0 - a4) */
17*3fbf3534SGeorge Guo	st.d		a5, sp, 8
18*3fbf3534SGeorge Guo	st.d		a0, sp, 16
19*3fbf3534SGeorge Guo	st.d		a1, sp, 24
20*3fbf3534SGeorge Guo	st.d		a2, sp, 32
21*3fbf3534SGeorge Guo	st.d		a3, sp, 40
22*3fbf3534SGeorge Guo	st.d		a4, sp, 48
23*3fbf3534SGeorge Guo
24*3fbf3534SGeorge Guo	/*
25*3fbf3534SGeorge Guo	 * BPF_REG_AX (t0) holds the offset passed in by the verifier;
26*3fbf3534SGeorge Guo	 * add it to BPF_REG_FP (s4) to get the pointer to the count and
27*3fbf3534SGeorge Guo	 * timestamp, then pass it as the first argument in a0.
28*3fbf3534SGeorge Guo	 *
29*3fbf3534SGeorge Guo	 * The verifier emits a load using FP right before this call,
30*3fbf3534SGeorge Guo	 * so BPF_REG_FP (s4) is always set up by the JIT in this case.
31*3fbf3534SGeorge Guo	 */
32*3fbf3534SGeorge Guo	add.d		a0, t0, s4
33*3fbf3534SGeorge Guo	bl		bpf_check_timed_may_goto
34*3fbf3534SGeorge Guo	/* BPF_REG_AX (t0) will be stored into count, so move the return value to it. */
35*3fbf3534SGeorge Guo	move		t0, a0
36*3fbf3534SGeorge Guo
37*3fbf3534SGeorge Guo	ld.d		ra, sp, 56
38*3fbf3534SGeorge Guo	ld.d		a5, sp, 8
39*3fbf3534SGeorge Guo	ld.d		a0, sp, 16
40*3fbf3534SGeorge Guo	ld.d		a1, sp, 24
41*3fbf3534SGeorge Guo	ld.d		a2, sp, 32
42*3fbf3534SGeorge Guo	ld.d		a3, sp, 40
43*3fbf3534SGeorge Guo	ld.d		a4, sp, 48
44*3fbf3534SGeorge Guo	addi.d		sp, sp, 64
45*3fbf3534SGeorge Guo
46*3fbf3534SGeorge Guo	jr		ra
47*3fbf3534SGeorge GuoSYM_FUNC_END(arch_bpf_timed_may_goto)
48