xref: /openbmc/linux/arch/s390/include/asm/futex.h (revision cef69974)
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/asm-extable.h>
8 #include <asm/mmu_context.h>
9 #include <asm/errno.h>
10 
11 #define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg)	\
12 	asm volatile(							\
13 		"   sacf  256\n"					\
14 		"0: l     %1,0(%6)\n"					\
15 		"1:"insn						\
16 		"2: cs    %1,%2,0(%6)\n"				\
17 		"3: jl    1b\n"						\
18 		"   lhi   %0,0\n"					\
19 		"4: sacf  768\n"					\
20 		EX_TABLE(0b,4b) 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 
26 static 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 
31 	switch (op) {
32 	case FUTEX_OP_SET:
33 		__futex_atomic_op("lr %2,%5\n",
34 				  ret, oldval, newval, uaddr, oparg);
35 		break;
36 	case FUTEX_OP_ADD:
37 		__futex_atomic_op("lr %2,%1\nar %2,%5\n",
38 				  ret, oldval, newval, uaddr, oparg);
39 		break;
40 	case FUTEX_OP_OR:
41 		__futex_atomic_op("lr %2,%1\nor %2,%5\n",
42 				  ret, oldval, newval, uaddr, oparg);
43 		break;
44 	case FUTEX_OP_ANDN:
45 		__futex_atomic_op("lr %2,%1\nnr %2,%5\n",
46 				  ret, oldval, newval, uaddr, oparg);
47 		break;
48 	case FUTEX_OP_XOR:
49 		__futex_atomic_op("lr %2,%1\nxr %2,%5\n",
50 				  ret, oldval, newval, uaddr, oparg);
51 		break;
52 	default:
53 		ret = -ENOSYS;
54 	}
55 
56 	if (!ret)
57 		*oval = oldval;
58 
59 	return ret;
60 }
61 
62 static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
63 						u32 oldval, u32 newval)
64 {
65 	int ret;
66 
67 	asm volatile(
68 		"   sacf 256\n"
69 		"0: cs   %1,%4,0(%5)\n"
70 		"1: la   %0,0\n"
71 		"2: sacf 768\n"
72 		EX_TABLE(0b,2b) EX_TABLE(1b,2b)
73 		: "=d" (ret), "+d" (oldval), "=m" (*uaddr)
74 		: "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
75 		: "cc", "memory");
76 	*uval = oldval;
77 	return ret;
78 }
79 
80 #endif /* _ASM_S390_FUTEX_H */
81