xref: /linux/arch/s390/net/bpf_timed_may_goto.S (revision 68a052239fc4b351e961f698b824f7654a346091)
1/* SPDX-License-Identifier: GPL-2.0 */
2
3#include <linux/export.h>
4#include <linux/linkage.h>
5#include <asm/asm-offsets.h>
6#include <asm/nospec-insn.h>
7
8#define R2_OFF 0
9#define R5_OFF (R2_OFF + (5 - 2 + 1) * 8)
10#define R14_OFF (R5_OFF + 8)
11#define RETADDR_OFF (R14_OFF + 8)
12#define R15_OFF (RETADDR_OFF + 8)
13#define BACKCHAIN_OFF (R15_OFF + 8)
14#define FRAME_SIZE (BACKCHAIN_OFF + 8)
15#define FRAME_OFF (STACK_FRAME_OVERHEAD - FRAME_SIZE)
16#if (FRAME_OFF + BACKCHAIN_OFF) != __SF_BACKCHAIN
17#error Stack frame layout calculation is broken
18#endif
19
20	GEN_BR_THUNK %r1
21
22SYM_FUNC_START(arch_bpf_timed_may_goto)
23	/*
24	 * This function has a special ABI: the parameters are in %r12 and
25	 * %r13; the return value is in %r12; all GPRs except %r0, %r1, and
26	 * %r12 are callee-saved; and the return address is in %r0.
27	 */
28	stmg %r2,%r5,FRAME_OFF+R2_OFF(%r15)
29	stg %r14,FRAME_OFF+R14_OFF(%r15)
30	stg %r0,FRAME_OFF+RETADDR_OFF(%r15)
31	stg %r15,FRAME_OFF+R15_OFF(%r15)
32	lgr %r1,%r15
33	lay %r15,-FRAME_SIZE(%r15)
34	stg %r1,__SF_BACKCHAIN(%r15)
35
36	lay %r2,0(%r12,%r13)
37	brasl %r14,bpf_check_timed_may_goto
38	lgr %r12,%r2
39
40	lg %r15,FRAME_SIZE+FRAME_OFF+R15_OFF(%r15)
41	lmg %r2,%r5,FRAME_OFF+R2_OFF(%r15)
42	lg %r14,FRAME_OFF+R14_OFF(%r15)
43	lg %r1,FRAME_OFF+RETADDR_OFF(%r15)
44	BR_EX %r1
45SYM_FUNC_END(arch_bpf_timed_may_goto)
46