1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_HEXAGON_FUTEX_H
3 #define _ASM_HEXAGON_FUTEX_H
4
5 #ifdef __KERNEL__
6
7 #include <linux/futex.h>
8 #include <linux/uaccess.h>
9 #include <asm/errno.h>
10
11 /* XXX TODO-- need to add sync barriers! */
12
13 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
14 __asm__ __volatile( \
15 "1: %0 = memw_locked(%3);\n" \
16 /* For example: %1 = %4 */ \
17 insn \
18 "2: memw_locked(%3,p2) = %1;\n" \
19 " if (!p2) jump 1b;\n" \
20 " %1 = #0;\n" \
21 "3:\n" \
22 ".section .fixup,\"ax\"\n" \
23 "4: %1 = #%5;\n" \
24 " jump ##3b\n" \
25 ".previous\n" \
26 ".section __ex_table,\"a\"\n" \
27 ".long 1b,4b,2b,4b\n" \
28 ".previous\n" \
29 : "=&r" (oldval), "=&r" (ret), "+m" (*uaddr) \
30 : "r" (uaddr), "r" (oparg), "i" (-EFAULT) \
31 : "p2", "memory")
32
33
34 static inline int
35 arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
36 {
37 int oldval = 0, ret;
38
39 if (!access_ok(uaddr, sizeof(u32)))
40 return -EFAULT;
41
42 switch (op) {
43 case FUTEX_OP_SET:
44 __futex_atomic_op("%1 = %4\n", ret, oldval, uaddr, oparg);
45 break;
46 case FUTEX_OP_ADD:
47 __futex_atomic_op("%1 = add(%0,%4)\n", ret, oldval, uaddr,
48 oparg);
49 break;
50 case FUTEX_OP_OR:
51 __futex_atomic_op("%1 = or(%0,%4)\n", ret, oldval, uaddr,
52 oparg);
53 break;
54 case FUTEX_OP_ANDN:
55 __futex_atomic_op("%1 = not(%4); %1 = and(%0,%1)\n", ret,
56 oldval, uaddr, oparg);
57 break;
58 case FUTEX_OP_XOR:
59 __futex_atomic_op("%1 = xor(%0,%4)\n", ret, oldval, uaddr,
60 oparg);
61 break;
62 default:
63 ret = -ENOSYS;
64 }
65
66 if (!ret)
67 *oval = oldval;
68
69 return ret;
70 }
71
72 static inline int
73 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval,
74 u32 newval)
75 {
76 int prev;
77 int ret;
78
79 if (!access_ok(uaddr, sizeof(u32)))
80 return -EFAULT;
81
82 __asm__ __volatile__ (
83 "1: %1 = memw_locked(%3)\n"
84 " {\n"
85 " p2 = cmp.eq(%1,%4)\n"
86 " if (!p2.new) jump:NT 3f\n"
87 " }\n"
88 "2: memw_locked(%3,p2) = %5\n"
89 " if (!p2) jump 1b\n"
90 "3:\n"
91 ".section .fixup,\"ax\"\n"
92 "4: %0 = #%6\n"
93 " jump ##3b\n"
94 ".previous\n"
95 ".section __ex_table,\"a\"\n"
96 ".long 1b,4b,2b,4b\n"
97 ".previous\n"
98 : "+r" (ret), "=&r" (prev), "+m" (*uaddr)
99 : "r" (uaddr), "r" (oldval), "r" (newval), "i"(-EFAULT)
100 : "p2", "memory");
101
102 *uval = prev;
103 return ret;
104 }
105
106 #endif /* __KERNEL__ */
107 #endif /* _ASM_HEXAGON_FUTEX_H */
108
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