1 | // SPDX-License-Identifier: GPL-2.0 |
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 | |
10 | #include <linux/kernel.h> |
11 | #include <linux/spinlock.h> |
12 | #include <linux/atomic.h> |
13 | |
14 | #ifdef CONFIG_SMP |
15 | arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = { |
16 | [0 ... (ATOMIC_HASH_SIZE-1)] = __ARCH_SPIN_LOCK_UNLOCKED |
17 | }; |
18 | #endif |
19 | |
20 | #ifdef CONFIG_64BIT |
21 | unsigned long notrace __xchg64(unsigned long x, volatile 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 notrace __xchg32(int x, volatile 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 notrace __xchg8(char x, volatile 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 | |
59 | u64 notrace __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new) |
60 | { |
61 | unsigned long flags; |
62 | u64 prev; |
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 | } |
70 | |
71 | unsigned long notrace __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 | } |
82 | |
83 | u8 notrace __cmpxchg_u8(volatile u8 *ptr, u8 old, u8 new) |
84 | { |
85 | unsigned long flags; |
86 | u8 prev; |
87 | |
88 | _atomic_spin_lock_irqsave(ptr, flags); |
89 | if ((prev = *ptr) == old) |
90 | *ptr = new; |
91 | _atomic_spin_unlock_irqrestore(ptr, flags); |
92 | return prev; |
93 | } |
94 | |