tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __ASM_OPENRISC_FUTEX_H
3#define __ASM_OPENRISC_FUTEX_H
4
5#ifdef __KERNEL__
6
7#include <linux/futex.h>
8#include <linux/uaccess.h>
9#include <asm/errno.h>
10
11#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
12({ \
13 __asm__ __volatile__ ( \
14 "1: l.lwa %0, %2 \n" \
15 insn "\n" \
16 "2: l.swa %2, %1 \n" \
17 " l.bnf 1b \n" \
18 " l.ori %1, r0, 0 \n" \
19 "3: \n" \
20 ".section .fixup,\"ax\" \n" \
21 "4: l.j 3b \n" \
22 " l.addi %1, r0, %3 \n" \
23 ".previous \n" \
24 ".section __ex_table,\"a\" \n" \
25 ".word 1b,4b,2b,4b \n" \
26 ".previous \n" \
27 : "=&r" (oldval), "=&r" (ret), "+m" (*uaddr) \
28 : "i" (-EFAULT), "r" (oparg) \
29 : "cc", "memory" \
30 ); \
31})
32
33static inline int
34arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
35{
36 int oldval = 0, ret;
37
38 pagefault_disable();
39
40 switch (op) {
41 case FUTEX_OP_SET:
42 __futex_atomic_op("l.or %1,%4,%4", ret, oldval, uaddr, oparg);
43 break;
44 case FUTEX_OP_ADD:
45 __futex_atomic_op("l.add %1,%0,%4", ret, oldval, uaddr, oparg);
46 break;
47 case FUTEX_OP_OR:
48 __futex_atomic_op("l.or %1,%0,%4", ret, oldval, uaddr, oparg);
49 break;
50 case FUTEX_OP_ANDN:
51 __futex_atomic_op("l.and %1,%0,%4", ret, oldval, uaddr, ~oparg);
52 break;
53 case FUTEX_OP_XOR:
54 __futex_atomic_op("l.xor %1,%0,%4", ret, oldval, uaddr, oparg);
55 break;
56 default:
57 ret = -ENOSYS;
58 }
59
60 pagefault_enable();
61
62 if (!ret)
63 *oval = oldval;
64
65 return ret;
66}
67
68static inline int
69futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
70 u32 oldval, u32 newval)
71{
72 int ret = 0;
73 u32 prev;
74
75 if (!access_ok(uaddr, sizeof(u32)))
76 return -EFAULT;
77
78 __asm__ __volatile__ ( \
79 "1: l.lwa %1, %2 \n" \
80 " l.sfeq %1, %3 \n" \
81 " l.bnf 3f \n" \
82 " l.nop \n" \
83 "2: l.swa %2, %4 \n" \
84 " l.bnf 1b \n" \
85 " l.nop \n" \
86 "3: \n" \
87 ".section .fixup,\"ax\" \n" \
88 "4: l.j 3b \n" \
89 " l.addi %0, r0, %5 \n" \
90 ".previous \n" \
91 ".section __ex_table,\"a\" \n" \
92 ".word 1b,4b,2b,4b \n" \
93 ".previous \n" \
94 : "+r" (ret), "=&r" (prev), "+m" (*uaddr) \
95 : "r" (oldval), "r" (newval), "i" (-EFAULT) \
96 : "cc", "memory" \
97 );
98
99 *uval = prev;
100 return ret;
101}
102
103#endif /* __KERNEL__ */
104
105#endif /* __ASM_OPENRISC_FUTEX_H */