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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * bitops.c: atomic operations which got too long to be inlined all over | |
4 | * the place. | |
5 | * | |
6 | * Copyright 1999 Philipp Rumpf (prumpf@tux.org) | |
7 | * Copyright 2000 Grant Grundler (grundler@cup.hp.com) | |
8 | */ | |
9 | ||
1da177e4 LT |
10 | #include <linux/kernel.h> |
11 | #include <linux/spinlock.h> | |
60063497 | 12 | #include <linux/atomic.h> |
1da177e4 LT |
13 | |
14 | #ifdef CONFIG_SMP | |
445c8951 | 15 | arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = { |
edc35bd7 | 16 | [0 ... (ATOMIC_HASH_SIZE-1)] = __ARCH_SPIN_LOCK_UNLOCKED |
1da177e4 LT |
17 | }; |
18 | #endif | |
19 | ||
a8f44e38 | 20 | #ifdef CONFIG_64BIT |
1da177e4 LT |
21 | unsigned long __xchg64(unsigned long x, unsigned long *ptr) |
22 | { | |
23 | unsigned long temp, flags; | |
24 | ||
25 | _atomic_spin_lock_irqsave(ptr, flags); | |
26 | temp = *ptr; | |
27 | *ptr = x; | |
28 | _atomic_spin_unlock_irqrestore(ptr, flags); | |
29 | return temp; | |
30 | } | |
31 | #endif | |
32 | ||
33 | unsigned long __xchg32(int x, int *ptr) | |
34 | { | |
35 | unsigned long flags; | |
36 | long temp; | |
37 | ||
38 | _atomic_spin_lock_irqsave(ptr, flags); | |
39 | temp = (long) *ptr; /* XXX - sign extension wanted? */ | |
40 | *ptr = x; | |
41 | _atomic_spin_unlock_irqrestore(ptr, flags); | |
42 | return (unsigned long)temp; | |
43 | } | |
44 | ||
45 | ||
46 | unsigned long __xchg8(char x, char *ptr) | |
47 | { | |
48 | unsigned long flags; | |
49 | long temp; | |
50 | ||
51 | _atomic_spin_lock_irqsave(ptr, flags); | |
52 | temp = (long) *ptr; /* XXX - sign extension wanted? */ | |
53 | *ptr = x; | |
54 | _atomic_spin_unlock_irqrestore(ptr, flags); | |
55 | return (unsigned long)temp; | |
56 | } | |
57 | ||
58 | ||
54b66800 | 59 | u64 __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new) |
1da177e4 LT |
60 | { |
61 | unsigned long flags; | |
54b66800 | 62 | u64 prev; |
1da177e4 LT |
63 | |
64 | _atomic_spin_lock_irqsave(ptr, flags); | |
65 | if ((prev = *ptr) == old) | |
66 | *ptr = new; | |
67 | _atomic_spin_unlock_irqrestore(ptr, flags); | |
68 | return prev; | |
69 | } | |
1da177e4 LT |
70 | |
71 | unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsigned int new) | |
72 | { | |
73 | unsigned long flags; | |
74 | unsigned int prev; | |
75 | ||
76 | _atomic_spin_lock_irqsave(ptr, flags); | |
77 | if ((prev = *ptr) == old) | |
78 | *ptr = new; | |
79 | _atomic_spin_unlock_irqrestore(ptr, flags); | |
80 | return (unsigned long)prev; | |
81 | } |