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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_POWERPC_FUTEX_H
3#define _ASM_POWERPC_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/synch.h>
11
12#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
13 __asm__ __volatile ( \
14 PPC_ATOMIC_ENTRY_BARRIER \
15"1: lwarx %0,0,%2\n" \
16 insn \
17"2: stwcx. %1,0,%2\n" \
18 "bne- 1b\n" \
19 PPC_ATOMIC_EXIT_BARRIER \
20 "li %1,0\n" \
21"3: .section .fixup,\"ax\"\n" \
22"4: li %1,%3\n" \
23 "b 3b\n" \
24 ".previous\n" \
25 EX_TABLE(1b, 4b) \
26 EX_TABLE(2b, 4b) \
27 : "=&r" (oldval), "=&r" (ret) \
28 : "b" (uaddr), "i" (-EFAULT), "r" (oparg) \
29 : "cr0", "memory")
30
31static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
32 u32 __user *uaddr)
33{
34 int oldval = 0, ret;
35
36 if (!user_access_begin(uaddr, sizeof(u32)))
37 return -EFAULT;
38
39 switch (op) {
40 case FUTEX_OP_SET:
41 __futex_atomic_op("mr %1,%4\n", ret, oldval, uaddr, oparg);
42 break;
43 case FUTEX_OP_ADD:
44 __futex_atomic_op("add %1,%0,%4\n", ret, oldval, uaddr, oparg);
45 break;
46 case FUTEX_OP_OR:
47 __futex_atomic_op("or %1,%0,%4\n", ret, oldval, uaddr, oparg);
48 break;
49 case FUTEX_OP_ANDN:
50 __futex_atomic_op("andc %1,%0,%4\n", ret, oldval, uaddr, oparg);
51 break;
52 case FUTEX_OP_XOR:
53 __futex_atomic_op("xor %1,%0,%4\n", ret, oldval, uaddr, oparg);
54 break;
55 default:
56 ret = -ENOSYS;
57 }
58 user_access_end();
59
60 *oval = oldval;
61
62 return ret;
63}
64
65static inline int
66futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
67 u32 oldval, u32 newval)
68{
69 int ret = 0;
70 u32 prev;
71
72 if (!user_access_begin(uaddr, sizeof(u32)))
73 return -EFAULT;
74
75 __asm__ __volatile__ (
76 PPC_ATOMIC_ENTRY_BARRIER
77"1: lwarx %1,0,%3 # futex_atomic_cmpxchg_inatomic\n\
78 cmpw 0,%1,%4\n\
79 bne- 3f\n"
80"2: stwcx. %5,0,%3\n\
81 bne- 1b\n"
82 PPC_ATOMIC_EXIT_BARRIER
83"3: .section .fixup,\"ax\"\n\
844: li %0,%6\n\
85 b 3b\n\
86 .previous\n"
87 EX_TABLE(1b, 4b)
88 EX_TABLE(2b, 4b)
89 : "+r" (ret), "=&r" (prev), "+m" (*uaddr)
90 : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT)
91 : "cc", "memory");
92
93 user_access_end();
94
95 *uval = prev;
96
97 return ret;
98}
99
100#endif /* __KERNEL__ */
101#endif /* _ASM_POWERPC_FUTEX_H */
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_POWERPC_FUTEX_H
3#define _ASM_POWERPC_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/synch.h>
11#include <asm/asm-405.h>
12
13#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
14 __asm__ __volatile ( \
15 PPC_ATOMIC_ENTRY_BARRIER \
16"1: lwarx %0,0,%2\n" \
17 insn \
18 PPC405_ERR77(0, %2) \
19"2: stwcx. %1,0,%2\n" \
20 "bne- 1b\n" \
21 PPC_ATOMIC_EXIT_BARRIER \
22 "li %1,0\n" \
23"3: .section .fixup,\"ax\"\n" \
24"4: li %1,%3\n" \
25 "b 3b\n" \
26 ".previous\n" \
27 EX_TABLE(1b, 4b) \
28 EX_TABLE(2b, 4b) \
29 : "=&r" (oldval), "=&r" (ret) \
30 : "b" (uaddr), "i" (-EFAULT), "r" (oparg) \
31 : "cr0", "memory")
32
33static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
34 u32 __user *uaddr)
35{
36 int oldval = 0, ret;
37
38 allow_write_to_user(uaddr, sizeof(*uaddr));
39 pagefault_disable();
40
41 switch (op) {
42 case FUTEX_OP_SET:
43 __futex_atomic_op("mr %1,%4\n", ret, oldval, uaddr, oparg);
44 break;
45 case FUTEX_OP_ADD:
46 __futex_atomic_op("add %1,%0,%4\n", ret, oldval, uaddr, oparg);
47 break;
48 case FUTEX_OP_OR:
49 __futex_atomic_op("or %1,%0,%4\n", ret, oldval, uaddr, oparg);
50 break;
51 case FUTEX_OP_ANDN:
52 __futex_atomic_op("andc %1,%0,%4\n", ret, oldval, uaddr, oparg);
53 break;
54 case FUTEX_OP_XOR:
55 __futex_atomic_op("xor %1,%0,%4\n", ret, oldval, uaddr, oparg);
56 break;
57 default:
58 ret = -ENOSYS;
59 }
60
61 pagefault_enable();
62
63 *oval = oldval;
64
65 prevent_write_to_user(uaddr, sizeof(*uaddr));
66 return ret;
67}
68
69static inline int
70futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
71 u32 oldval, u32 newval)
72{
73 int ret = 0;
74 u32 prev;
75
76 if (!access_ok(uaddr, sizeof(u32)))
77 return -EFAULT;
78
79 allow_write_to_user(uaddr, sizeof(*uaddr));
80 __asm__ __volatile__ (
81 PPC_ATOMIC_ENTRY_BARRIER
82"1: lwarx %1,0,%3 # futex_atomic_cmpxchg_inatomic\n\
83 cmpw 0,%1,%4\n\
84 bne- 3f\n"
85 PPC405_ERR77(0,%3)
86"2: stwcx. %5,0,%3\n\
87 bne- 1b\n"
88 PPC_ATOMIC_EXIT_BARRIER
89"3: .section .fixup,\"ax\"\n\
904: li %0,%6\n\
91 b 3b\n\
92 .previous\n"
93 EX_TABLE(1b, 4b)
94 EX_TABLE(2b, 4b)
95 : "+r" (ret), "=&r" (prev), "+m" (*uaddr)
96 : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT)
97 : "cc", "memory");
98
99 *uval = prev;
100 prevent_write_to_user(uaddr, sizeof(*uaddr));
101 return ret;
102}
103
104#endif /* __KERNEL__ */
105#endif /* _ASM_POWERPC_FUTEX_H */