1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * forked from parisc asm/atomic.h which was:
4*4882a593Smuzhiyun * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
5*4882a593Smuzhiyun * Copyright (C) 2006 Kyle McMartin <kyle@parisc-linux.org>
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun #ifndef _ASM_PARISC_CMPXCHG_H_
9*4882a593Smuzhiyun #define _ASM_PARISC_CMPXCHG_H_
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun /* This should get optimized out since it's never called.
12*4882a593Smuzhiyun ** Or get a link error if xchg is used "wrong".
13*4882a593Smuzhiyun */
14*4882a593Smuzhiyun extern void __xchg_called_with_bad_pointer(void);
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun /* __xchg32/64 defined in arch/parisc/lib/bitops.c */
17*4882a593Smuzhiyun extern unsigned long __xchg8(char, volatile char *);
18*4882a593Smuzhiyun extern unsigned long __xchg32(int, volatile int *);
19*4882a593Smuzhiyun #ifdef CONFIG_64BIT
20*4882a593Smuzhiyun extern unsigned long __xchg64(unsigned long, volatile unsigned long *);
21*4882a593Smuzhiyun #endif
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun /* optimizer better get rid of switch since size is a constant */
24*4882a593Smuzhiyun static inline unsigned long
__xchg(unsigned long x,volatile void * ptr,int size)25*4882a593Smuzhiyun __xchg(unsigned long x, volatile void *ptr, int size)
26*4882a593Smuzhiyun {
27*4882a593Smuzhiyun switch (size) {
28*4882a593Smuzhiyun #ifdef CONFIG_64BIT
29*4882a593Smuzhiyun case 8: return __xchg64(x, (volatile unsigned long *) ptr);
30*4882a593Smuzhiyun #endif
31*4882a593Smuzhiyun case 4: return __xchg32((int) x, (volatile int *) ptr);
32*4882a593Smuzhiyun case 1: return __xchg8((char) x, (volatile char *) ptr);
33*4882a593Smuzhiyun }
34*4882a593Smuzhiyun __xchg_called_with_bad_pointer();
35*4882a593Smuzhiyun return x;
36*4882a593Smuzhiyun }
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun /*
39*4882a593Smuzhiyun ** REVISIT - Abandoned use of LDCW in xchg() for now:
40*4882a593Smuzhiyun ** o need to test sizeof(*ptr) to avoid clearing adjacent bytes
41*4882a593Smuzhiyun ** o and while we are at it, could CONFIG_64BIT code use LDCD too?
42*4882a593Smuzhiyun **
43*4882a593Smuzhiyun ** if (__builtin_constant_p(x) && (x == NULL))
44*4882a593Smuzhiyun ** if (((unsigned long)p & 0xf) == 0)
45*4882a593Smuzhiyun ** return __ldcw(p);
46*4882a593Smuzhiyun */
47*4882a593Smuzhiyun #define xchg(ptr, x) \
48*4882a593Smuzhiyun ({ \
49*4882a593Smuzhiyun __typeof__(*(ptr)) __ret; \
50*4882a593Smuzhiyun __typeof__(*(ptr)) _x_ = (x); \
51*4882a593Smuzhiyun __ret = (__typeof__(*(ptr))) \
52*4882a593Smuzhiyun __xchg((unsigned long)_x_, (ptr), sizeof(*(ptr))); \
53*4882a593Smuzhiyun __ret; \
54*4882a593Smuzhiyun })
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun /* bug catcher for when unsupported size is used - won't link */
57*4882a593Smuzhiyun extern void __cmpxchg_called_with_bad_pointer(void);
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun /* __cmpxchg_u32/u64 defined in arch/parisc/lib/bitops.c */
60*4882a593Smuzhiyun extern unsigned long __cmpxchg_u32(volatile unsigned int *m, unsigned int old,
61*4882a593Smuzhiyun unsigned int new_);
62*4882a593Smuzhiyun extern u64 __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new_);
63*4882a593Smuzhiyun extern u8 __cmpxchg_u8(volatile u8 *ptr, u8 old, u8 new_);
64*4882a593Smuzhiyun
65*4882a593Smuzhiyun /* don't worry...optimizer will get rid of most of this */
66*4882a593Smuzhiyun static inline unsigned long
__cmpxchg(volatile void * ptr,unsigned long old,unsigned long new_,int size)67*4882a593Smuzhiyun __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
68*4882a593Smuzhiyun {
69*4882a593Smuzhiyun switch (size) {
70*4882a593Smuzhiyun #ifdef CONFIG_64BIT
71*4882a593Smuzhiyun case 8: return __cmpxchg_u64((u64 *)ptr, old, new_);
72*4882a593Smuzhiyun #endif
73*4882a593Smuzhiyun case 4: return __cmpxchg_u32((unsigned int *)ptr,
74*4882a593Smuzhiyun (unsigned int)old, (unsigned int)new_);
75*4882a593Smuzhiyun case 1: return __cmpxchg_u8((u8 *)ptr, old & 0xff, new_ & 0xff);
76*4882a593Smuzhiyun }
77*4882a593Smuzhiyun __cmpxchg_called_with_bad_pointer();
78*4882a593Smuzhiyun return old;
79*4882a593Smuzhiyun }
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun #define cmpxchg(ptr, o, n) \
82*4882a593Smuzhiyun ({ \
83*4882a593Smuzhiyun __typeof__(*(ptr)) _o_ = (o); \
84*4882a593Smuzhiyun __typeof__(*(ptr)) _n_ = (n); \
85*4882a593Smuzhiyun (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
86*4882a593Smuzhiyun (unsigned long)_n_, sizeof(*(ptr))); \
87*4882a593Smuzhiyun })
88*4882a593Smuzhiyun
89*4882a593Smuzhiyun #include <asm-generic/cmpxchg-local.h>
90*4882a593Smuzhiyun
__cmpxchg_local(volatile void * ptr,unsigned long old,unsigned long new_,int size)91*4882a593Smuzhiyun static inline unsigned long __cmpxchg_local(volatile void *ptr,
92*4882a593Smuzhiyun unsigned long old,
93*4882a593Smuzhiyun unsigned long new_, int size)
94*4882a593Smuzhiyun {
95*4882a593Smuzhiyun switch (size) {
96*4882a593Smuzhiyun #ifdef CONFIG_64BIT
97*4882a593Smuzhiyun case 8: return __cmpxchg_u64((u64 *)ptr, old, new_);
98*4882a593Smuzhiyun #endif
99*4882a593Smuzhiyun case 4: return __cmpxchg_u32(ptr, old, new_);
100*4882a593Smuzhiyun default:
101*4882a593Smuzhiyun return __cmpxchg_local_generic(ptr, old, new_, size);
102*4882a593Smuzhiyun }
103*4882a593Smuzhiyun }
104*4882a593Smuzhiyun
105*4882a593Smuzhiyun /*
106*4882a593Smuzhiyun * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
107*4882a593Smuzhiyun * them available.
108*4882a593Smuzhiyun */
109*4882a593Smuzhiyun #define cmpxchg_local(ptr, o, n) \
110*4882a593Smuzhiyun ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
111*4882a593Smuzhiyun (unsigned long)(n), sizeof(*(ptr))))
112*4882a593Smuzhiyun #ifdef CONFIG_64BIT
113*4882a593Smuzhiyun #define cmpxchg64_local(ptr, o, n) \
114*4882a593Smuzhiyun ({ \
115*4882a593Smuzhiyun BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
116*4882a593Smuzhiyun cmpxchg_local((ptr), (o), (n)); \
117*4882a593Smuzhiyun })
118*4882a593Smuzhiyun #else
119*4882a593Smuzhiyun #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
120*4882a593Smuzhiyun #endif
121*4882a593Smuzhiyun
122*4882a593Smuzhiyun #define cmpxchg64(ptr, o, n) __cmpxchg_u64(ptr, o, n)
123*4882a593Smuzhiyun
124*4882a593Smuzhiyun #endif /* _ASM_PARISC_CMPXCHG_H_ */
125