2 * Copyright IBM Corp. 1999, 2011
4 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
7 #ifndef __ASM_CMPXCHG_H
8 #define __ASM_CMPXCHG_H
10 #include <linux/types.h>
12 extern void __xchg_called_with_bad_pointer(void);
14 static inline unsigned long __xchg(unsigned long x, void *ptr, int size)
16 unsigned long addr, old;
21 addr = (unsigned long) ptr;
22 shift = (3 ^ (addr & 3)) << 3;
31 : "=&d" (old), "=Q" (*(int *) addr)
32 : "d" (x << shift), "d" (~(255 << shift)),
33 "Q" (*(int *) addr) : "memory", "cc", "0");
36 addr = (unsigned long) ptr;
37 shift = (2 ^ (addr & 2)) << 3;
46 : "=&d" (old), "=Q" (*(int *) addr)
47 : "d" (x << shift), "d" (~(65535 << shift)),
48 "Q" (*(int *) addr) : "memory", "cc", "0");
55 : "=&d" (old), "=Q" (*(int *) ptr)
56 : "d" (x), "Q" (*(int *) ptr)
65 : "=&d" (old), "=m" (*(long *) ptr)
66 : "d" (x), "Q" (*(long *) ptr)
69 #endif /* CONFIG_64BIT */
71 __xchg_called_with_bad_pointer();
75 #define xchg(ptr, x) \
77 __typeof__(*(ptr)) __ret; \
78 __ret = (__typeof__(*(ptr))) \
79 __xchg((unsigned long)(x), (void *)(ptr), sizeof(*(ptr)));\
84 * Atomic compare and exchange. Compare OLD with MEM, if identical,
85 * store NEW in MEM. Return the initial value in MEM. Success is
86 * indicated by comparing RETURN with OLD.
89 #define __HAVE_ARCH_CMPXCHG
91 extern void __cmpxchg_called_with_bad_pointer(void);
93 static inline unsigned long __cmpxchg(void *ptr, unsigned long old,
94 unsigned long new, int size)
96 unsigned long addr, prev, tmp;
101 addr = (unsigned long) ptr;
102 shift = (3 ^ (addr & 3)) << 3;
116 : "=&d" (prev), "=&d" (tmp), "=Q" (*(int *) ptr)
117 : "d" (old << shift), "d" (new << shift),
118 "d" (~(255 << shift)), "Q" (*(int *) ptr)
120 return prev >> shift;
122 addr = (unsigned long) ptr;
123 shift = (2 ^ (addr & 2)) << 3;
137 : "=&d" (prev), "=&d" (tmp), "=Q" (*(int *) ptr)
138 : "d" (old << shift), "d" (new << shift),
139 "d" (~(65535 << shift)), "Q" (*(int *) ptr)
141 return prev >> shift;
145 : "=&d" (prev), "=Q" (*(int *) ptr)
146 : "0" (old), "d" (new), "Q" (*(int *) ptr)
153 : "=&d" (prev), "=Q" (*(long *) ptr)
154 : "0" (old), "d" (new), "Q" (*(long *) ptr)
157 #endif /* CONFIG_64BIT */
159 __cmpxchg_called_with_bad_pointer();
163 #define cmpxchg(ptr, o, n) \
164 ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \
165 (unsigned long)(n), sizeof(*(ptr))))
168 #define cmpxchg64(ptr, o, n) \
170 cmpxchg((ptr), (o), (n)); \
172 #else /* CONFIG_64BIT */
173 static inline unsigned long long __cmpxchg64(void *ptr,
174 unsigned long long old,
175 unsigned long long new)
177 register_pair rp_old = {.pair = old};
178 register_pair rp_new = {.pair = new};
182 : "+&d" (rp_old), "=Q" (ptr)
183 : "d" (rp_new), "Q" (ptr)
187 #define cmpxchg64(ptr, o, n) \
188 ((__typeof__(*(ptr)))__cmpxchg64((ptr), \
189 (unsigned long long)(o), \
190 (unsigned long long)(n)))
191 #endif /* CONFIG_64BIT */
193 #include <asm-generic/cmpxchg-local.h>
195 static inline unsigned long __cmpxchg_local(void *ptr,
197 unsigned long new, int size)
206 return __cmpxchg(ptr, old, new, size);
208 return __cmpxchg_local_generic(ptr, old, new, size);
215 * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
218 #define cmpxchg_local(ptr, o, n) \
219 ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
220 (unsigned long)(n), sizeof(*(ptr))))
222 #define cmpxchg64_local(ptr, o, n) cmpxchg64((ptr), (o), (n))
224 #endif /* __ASM_CMPXCHG_H */