1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_S390_FUTEX_H
3#define _ASM_S390_FUTEX_H
4
5#include <linux/uaccess.h>
6#include <linux/futex.h>
7#include <asm/mmu_context.h>
8#include <asm/errno.h>
9
10#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg)	\
11	asm volatile(							\
12		"   sacf  256\n"					\
13		"0: l     %1,0(%6)\n"					\
14		"1:"insn						\
15		"2: cs    %1,%2,0(%6)\n"				\
16		"3: jl    1b\n"						\
17		"   lhi   %0,0\n"					\
18		"4: sacf  768\n"					\
19		EX_TABLE(0b,4b) EX_TABLE(1b,4b)				\
20		EX_TABLE(2b,4b) EX_TABLE(3b,4b)				\
21		: "=d" (ret), "=&d" (oldval), "=&d" (newval),		\
22		  "=m" (*uaddr)						\
23		: "0" (-EFAULT), "d" (oparg), "a" (uaddr),		\
24		  "m" (*uaddr) : "cc");
25
26static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
27		u32 __user *uaddr)
28{
29	int oldval = 0, newval, ret;
30	mm_segment_t old_fs;
31
32	old_fs = enable_sacf_uaccess();
33	switch (op) {
34	case FUTEX_OP_SET:
35		__futex_atomic_op("lr %2,%5\n",
36				  ret, oldval, newval, uaddr, oparg);
37		break;
38	case FUTEX_OP_ADD:
39		__futex_atomic_op("lr %2,%1\nar %2,%5\n",
40				  ret, oldval, newval, uaddr, oparg);
41		break;
42	case FUTEX_OP_OR:
43		__futex_atomic_op("lr %2,%1\nor %2,%5\n",
44				  ret, oldval, newval, uaddr, oparg);
45		break;
46	case FUTEX_OP_ANDN:
47		__futex_atomic_op("lr %2,%1\nnr %2,%5\n",
48				  ret, oldval, newval, uaddr, oparg);
49		break;
50	case FUTEX_OP_XOR:
51		__futex_atomic_op("lr %2,%1\nxr %2,%5\n",
52				  ret, oldval, newval, uaddr, oparg);
53		break;
54	default:
55		ret = -ENOSYS;
56	}
57	disable_sacf_uaccess(old_fs);
58
59	if (!ret)
60		*oval = oldval;
61
62	return ret;
63}
64
65static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
66						u32 oldval, u32 newval)
67{
68	mm_segment_t old_fs;
69	int ret;
70
71	old_fs = enable_sacf_uaccess();
72	asm volatile(
73		"   sacf 256\n"
74		"0: cs   %1,%4,0(%5)\n"
75		"1: la   %0,0\n"
76		"2: sacf 768\n"
77		EX_TABLE(0b,2b) EX_TABLE(1b,2b)
78		: "=d" (ret), "+d" (oldval), "=m" (*uaddr)
79		: "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
80		: "cc", "memory");
81	disable_sacf_uaccess(old_fs);
82	*uval = oldval;
83	return ret;
84}
85
86#endif /* _ASM_S390_FUTEX_H */
87