2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 2003, 06, 07 by Ralf Baechle (ralf@linux-mips.org)
8 #ifndef __ASM_CMPXCHG_H
9 #define __ASM_CMPXCHG_H
11 #include <linux/bug.h>
12 #include <linux/irqflags.h>
15 static inline unsigned long __xchg_u32(volatile int * m
, unsigned int val
)
19 smp_mb__before_llsc();
21 if (kernel_uses_llsc
&& R10000_LLSC_WAR
) {
26 "1: ll %0, %3 # xchg_u32 \n"
33 : "=&r" (retval
), "=m" (*m
), "=&r" (dummy
)
34 : "R" (*m
), "Jr" (val
)
36 } else if (kernel_uses_llsc
) {
42 " ll %0, %3 # xchg_u32 \n"
48 : "=&r" (retval
), "=m" (*m
), "=&r" (dummy
)
49 : "R" (*m
), "Jr" (val
)
51 } while (unlikely(!dummy
));
55 raw_local_irq_save(flags
);
58 raw_local_irq_restore(flags
); /* implies memory barrier */
67 static inline __u64
__xchg_u64(volatile __u64
* m
, __u64 val
)
71 smp_mb__before_llsc();
73 if (kernel_uses_llsc
&& R10000_LLSC_WAR
) {
78 "1: lld %0, %3 # xchg_u64 \n"
83 : "=&r" (retval
), "=m" (*m
), "=&r" (dummy
)
84 : "R" (*m
), "Jr" (val
)
86 } else if (kernel_uses_llsc
) {
92 " lld %0, %3 # xchg_u64 \n"
96 : "=&r" (retval
), "=m" (*m
), "=&r" (dummy
)
97 : "R" (*m
), "Jr" (val
)
99 } while (unlikely(!dummy
));
103 raw_local_irq_save(flags
);
106 raw_local_irq_restore(flags
); /* implies memory barrier */
114 extern __u64
__xchg_u64_unsupported_on_32bit_kernels(volatile __u64
* m
, __u64 val
);
115 #define __xchg_u64 __xchg_u64_unsupported_on_32bit_kernels
118 static inline unsigned long __xchg(unsigned long x
, volatile void * ptr
, int size
)
122 return __xchg_u32(ptr
, x
);
124 return __xchg_u64(ptr
, x
);
130 #define xchg(ptr, x) \
132 BUILD_BUG_ON(sizeof(*(ptr)) & ~0xc); \
134 ((__typeof__(*(ptr))) \
135 __xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))); \
138 #define __HAVE_ARCH_CMPXCHG 1
140 #define __cmpxchg_asm(ld, st, m, old, new) \
142 __typeof(*(m)) __ret; \
144 if (kernel_uses_llsc && R10000_LLSC_WAR) { \
145 __asm__ __volatile__( \
149 "1: " ld " %0, %2 # __cmpxchg_asm \n" \
150 " bne %0, %z3, 2f \n" \
154 " " st " $1, %1 \n" \
158 : "=&r" (__ret), "=R" (*m) \
159 : "R" (*m), "Jr" (old), "Jr" (new) \
161 } else if (kernel_uses_llsc) { \
162 __asm__ __volatile__( \
166 "1: " ld " %0, %2 # __cmpxchg_asm \n" \
167 " bne %0, %z3, 2f \n" \
171 " " st " $1, %1 \n" \
175 : "=&r" (__ret), "=R" (*m) \
176 : "R" (*m), "Jr" (old), "Jr" (new) \
179 unsigned long __flags; \
181 raw_local_irq_save(__flags); \
185 raw_local_irq_restore(__flags); \
192 * This function doesn't exist, so you'll get a linker error
193 * if something tries to do an invalid cmpxchg().
195 extern void __cmpxchg_called_with_bad_pointer(void);
197 #define __cmpxchg(ptr, old, new, pre_barrier, post_barrier) \
199 __typeof__(ptr) __ptr = (ptr); \
200 __typeof__(*(ptr)) __old = (old); \
201 __typeof__(*(ptr)) __new = (new); \
202 __typeof__(*(ptr)) __res = 0; \
206 switch (sizeof(*(__ptr))) { \
208 __res = __cmpxchg_asm("ll", "sc", __ptr, __old, __new); \
211 if (sizeof(long) == 8) { \
212 __res = __cmpxchg_asm("lld", "scd", __ptr, \
217 __cmpxchg_called_with_bad_pointer(); \
226 #define cmpxchg(ptr, old, new) __cmpxchg(ptr, old, new, smp_mb__before_llsc(), smp_llsc_mb())
227 #define cmpxchg_local(ptr, old, new) __cmpxchg(ptr, old, new, , )
229 #define cmpxchg64(ptr, o, n) \
231 BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
232 cmpxchg((ptr), (o), (n)); \
236 #define cmpxchg64_local(ptr, o, n) \
238 BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
239 cmpxchg_local((ptr), (o), (n)); \
242 #include <asm-generic/cmpxchg-local.h>
243 #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
246 #endif /* __ASM_CMPXCHG_H */