1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_ALPHA_FUTEX_H
3 #define _ASM_ALPHA_FUTEX_H
4
5 #ifdef __KERNEL__
6
7 #include <linux/futex.h>
8 #include <linux/uaccess.h>
9 #include <asm/errno.h>
10 #include <asm/barrier.h>
11
12 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
13 __asm__ __volatile__( \
14 __ASM_SMP_MB \
15 "1: ldl_l %0,0(%2)\n" \
16 insn \
17 "2: stl_c %1,0(%2)\n" \
18 " beq %1,4f\n" \
19 " mov $31,%1\n" \
20 "3: .subsection 2\n" \
21 "4: br 1b\n" \
22 " .previous\n" \
23 EXC(1b,3b,$31,%1) \
24 EXC(2b,3b,$31,%1) \
25 : "=&r" (oldval), "=&r"(ret) \
26 : "r" (uaddr), "r"(oparg) \
27 : "memory")
28
arch_futex_atomic_op_inuser(int op,int oparg,int * oval,u32 __user * uaddr)29 static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
30 u32 __user *uaddr)
31 {
32 int oldval = 0, ret;
33
34 pagefault_disable();
35
36 switch (op) {
37 case FUTEX_OP_SET:
38 __futex_atomic_op("mov %3,%1\n", ret, oldval, uaddr, oparg);
39 break;
40 case FUTEX_OP_ADD:
41 __futex_atomic_op("addl %0,%3,%1\n", ret, oldval, uaddr, oparg);
42 break;
43 case FUTEX_OP_OR:
44 __futex_atomic_op("or %0,%3,%1\n", ret, oldval, uaddr, oparg);
45 break;
46 case FUTEX_OP_ANDN:
47 __futex_atomic_op("andnot %0,%3,%1\n", ret, oldval, uaddr, oparg);
48 break;
49 case FUTEX_OP_XOR:
50 __futex_atomic_op("xor %0,%3,%1\n", ret, oldval, uaddr, oparg);
51 break;
52 default:
53 ret = -ENOSYS;
54 }
55
56 pagefault_enable();
57
58 if (!ret)
59 *oval = oldval;
60
61 return ret;
62 }
63
64 static inline int
futex_atomic_cmpxchg_inatomic(u32 * uval,u32 __user * uaddr,u32 oldval,u32 newval)65 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
66 u32 oldval, u32 newval)
67 {
68 int ret = 0, cmp;
69 u32 prev;
70
71 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
72 return -EFAULT;
73
74 __asm__ __volatile__ (
75 __ASM_SMP_MB
76 "1: ldl_l %1,0(%3)\n"
77 " cmpeq %1,%4,%2\n"
78 " beq %2,3f\n"
79 " mov %5,%2\n"
80 "2: stl_c %2,0(%3)\n"
81 " beq %2,4f\n"
82 "3: .subsection 2\n"
83 "4: br 1b\n"
84 " .previous\n"
85 EXC(1b,3b,$31,%0)
86 EXC(2b,3b,$31,%0)
87 : "+r"(ret), "=&r"(prev), "=&r"(cmp)
88 : "r"(uaddr), "r"((long)(int)oldval), "r"(newval)
89 : "memory");
90
91 *uval = prev;
92 return ret;
93 }
94
95 #endif /* __KERNEL__ */
96 #endif /* _ASM_ALPHA_FUTEX_H */
97
