1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * bitops.c: atomic operations which got too long to be inlined all over
4*4882a593Smuzhiyun * the place.
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * Copyright 1999 Philipp Rumpf (prumpf@tux.org)
7*4882a593Smuzhiyun * Copyright 2000 Grant Grundler (grundler@cup.hp.com)
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <linux/kernel.h>
11*4882a593Smuzhiyun #include <linux/spinlock.h>
12*4882a593Smuzhiyun #include <linux/atomic.h>
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun #ifdef CONFIG_SMP
15*4882a593Smuzhiyun arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
16*4882a593Smuzhiyun [0 ... (ATOMIC_HASH_SIZE-1)] = __ARCH_SPIN_LOCK_UNLOCKED
17*4882a593Smuzhiyun };
18*4882a593Smuzhiyun #endif
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun #ifdef CONFIG_64BIT
__xchg64(unsigned long x,volatile unsigned long * ptr)21*4882a593Smuzhiyun unsigned long __xchg64(unsigned long x, volatile unsigned long *ptr)
22*4882a593Smuzhiyun {
23*4882a593Smuzhiyun unsigned long temp, flags;
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun _atomic_spin_lock_irqsave(ptr, flags);
26*4882a593Smuzhiyun temp = *ptr;
27*4882a593Smuzhiyun *ptr = x;
28*4882a593Smuzhiyun _atomic_spin_unlock_irqrestore(ptr, flags);
29*4882a593Smuzhiyun return temp;
30*4882a593Smuzhiyun }
31*4882a593Smuzhiyun #endif
32*4882a593Smuzhiyun
__xchg32(int x,volatile int * ptr)33*4882a593Smuzhiyun unsigned long __xchg32(int x, volatile int *ptr)
34*4882a593Smuzhiyun {
35*4882a593Smuzhiyun unsigned long flags;
36*4882a593Smuzhiyun long temp;
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun _atomic_spin_lock_irqsave(ptr, flags);
39*4882a593Smuzhiyun temp = (long) *ptr; /* XXX - sign extension wanted? */
40*4882a593Smuzhiyun *ptr = x;
41*4882a593Smuzhiyun _atomic_spin_unlock_irqrestore(ptr, flags);
42*4882a593Smuzhiyun return (unsigned long)temp;
43*4882a593Smuzhiyun }
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun
__xchg8(char x,volatile char * ptr)46*4882a593Smuzhiyun unsigned long __xchg8(char x, volatile char *ptr)
47*4882a593Smuzhiyun {
48*4882a593Smuzhiyun unsigned long flags;
49*4882a593Smuzhiyun long temp;
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun _atomic_spin_lock_irqsave(ptr, flags);
52*4882a593Smuzhiyun temp = (long) *ptr; /* XXX - sign extension wanted? */
53*4882a593Smuzhiyun *ptr = x;
54*4882a593Smuzhiyun _atomic_spin_unlock_irqrestore(ptr, flags);
55*4882a593Smuzhiyun return (unsigned long)temp;
56*4882a593Smuzhiyun }
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun
__cmpxchg_u64(volatile u64 * ptr,u64 old,u64 new)59*4882a593Smuzhiyun u64 __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new)
60*4882a593Smuzhiyun {
61*4882a593Smuzhiyun unsigned long flags;
62*4882a593Smuzhiyun u64 prev;
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun _atomic_spin_lock_irqsave(ptr, flags);
65*4882a593Smuzhiyun if ((prev = *ptr) == old)
66*4882a593Smuzhiyun *ptr = new;
67*4882a593Smuzhiyun _atomic_spin_unlock_irqrestore(ptr, flags);
68*4882a593Smuzhiyun return prev;
69*4882a593Smuzhiyun }
70*4882a593Smuzhiyun
__cmpxchg_u32(volatile unsigned int * ptr,unsigned int old,unsigned int new)71*4882a593Smuzhiyun unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsigned int new)
72*4882a593Smuzhiyun {
73*4882a593Smuzhiyun unsigned long flags;
74*4882a593Smuzhiyun unsigned int prev;
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun _atomic_spin_lock_irqsave(ptr, flags);
77*4882a593Smuzhiyun if ((prev = *ptr) == old)
78*4882a593Smuzhiyun *ptr = new;
79*4882a593Smuzhiyun _atomic_spin_unlock_irqrestore(ptr, flags);
80*4882a593Smuzhiyun return (unsigned long)prev;
81*4882a593Smuzhiyun }
82*4882a593Smuzhiyun
__cmpxchg_u8(volatile u8 * ptr,u8 old,u8 new)83*4882a593Smuzhiyun u8 __cmpxchg_u8(volatile u8 *ptr, u8 old, u8 new)
84*4882a593Smuzhiyun {
85*4882a593Smuzhiyun unsigned long flags;
86*4882a593Smuzhiyun u8 prev;
87*4882a593Smuzhiyun
88*4882a593Smuzhiyun _atomic_spin_lock_irqsave(ptr, flags);
89*4882a593Smuzhiyun if ((prev = *ptr) == old)
90*4882a593Smuzhiyun *ptr = new;
91*4882a593Smuzhiyun _atomic_spin_unlock_irqrestore(ptr, flags);
92*4882a593Smuzhiyun return prev;
93*4882a593Smuzhiyun }
94