xref: /linux/arch/sh/include/asm/futex.h (revision 02680c23d7b3febe45ea3d4f9818c2b2dc89020a)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_SH_FUTEX_H
3 #define __ASM_SH_FUTEX_H
4 
5 #include <linux/futex.h>
6 #include <linux/uaccess.h>
7 #include <asm/errno.h>
8 
9 #if !defined(CONFIG_SMP)
10 #include <asm/futex-irq.h>
11 #elif defined(CONFIG_CPU_J2)
12 #include <asm/futex-cas.h>
13 #elif defined(CONFIG_CPU_SH4A)
14 #include <asm/futex-llsc.h>
15 #else
16 #error SMP not supported on this configuration.
17 #endif
18 
19 static inline int
20 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
21 			      u32 oldval, u32 newval)
22 {
23 	if (!access_ok(uaddr, sizeof(u32)))
24 		return -EFAULT;
25 
26 	return atomic_futex_op_cmpxchg_inatomic(uval, uaddr, oldval, newval);
27 }
28 
29 static inline int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval,
30 		u32 __user *uaddr)
31 {
32 	u32 oldval, newval, prev;
33 	int ret;
34 
35 	do {
36 		ret = get_user(oldval, uaddr);
37 
38 		if (ret) break;
39 
40 		switch (op) {
41 		case FUTEX_OP_SET:
42 			newval = oparg;
43 			break;
44 		case FUTEX_OP_ADD:
45 			newval = oldval + oparg;
46 			break;
47 		case FUTEX_OP_OR:
48 			newval = oldval | oparg;
49 			break;
50 		case FUTEX_OP_ANDN:
51 			newval = oldval & ~oparg;
52 			break;
53 		case FUTEX_OP_XOR:
54 			newval = oldval ^ oparg;
55 			break;
56 		default:
57 			ret = -ENOSYS;
58 			break;
59 		}
60 
61 		if (ret) break;
62 
63 		ret = futex_atomic_cmpxchg_inatomic(&prev, uaddr, oldval, newval);
64 	} while (!ret && prev != oldval);
65 
66 	if (!ret)
67 		*oval = oldval;
68 
69 	return ret;
70 }
71 
72 #endif /* __ASM_SH_FUTEX_H */
73