/* * Generic UP xchg and cmpxchg using interrupt disablement. Does not * support SMP. */ #ifndef __ASM_GENERIC_CMPXCHG_H #define __ASM_GENERIC_CMPXCHG_H #ifdef CONFIG_SMP #error "Cannot use generic cmpxchg on SMP" #endif #include #include #ifndef xchg /* * This function doesn't exist, so you'll get a linker error if * something tries to do an invalidly-sized xchg(). */ extern void __xchg_called_with_bad_pointer(void); static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size) { unsigned long ret, flags; switch (size) { case 1: #ifdef __xchg_u8 return __xchg_u8(x, ptr); #else local_irq_save(flags); ret = *(volatile u8 *)ptr; *(volatile u8 *)ptr = x; local_irq_restore(flags); return ret; #endif /* __xchg_u8 */ case 2: #ifdef __xchg_u16 return __xchg_u16(x, ptr); #else local_irq_save(flags); ret = *(volatile u16 *)ptr; *(volatile u16 *)ptr = x; local_irq_restore(flags); return ret; #endif /* __xchg_u16 */ case 4: #ifdef __xchg_u32 return __xchg_u32(x, ptr); #else local_irq_save(flags); ret = *(volatile u32 *)ptr; *(volatile u32 *)ptr = x; local_irq_restore(flags); return ret; #endif /* __xchg_u32 */ #ifdef CONFIG_64BIT case 8: #ifdef __xchg_u64 return __xchg_u64(x, ptr); #else local_irq_save(flags); ret = *(volatile u64 *)ptr; *(volatile u64 *)ptr = x; local_irq_restore(flags); return ret; #endif /* __xchg_u64 */ #endif /* CONFIG_64BIT */ default: __xchg_called_with_bad_pointer(); return x; } } #define xchg(ptr, x) ({ \ ((__typeof__(*(ptr))) \ __xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))); \ }) #endif /* xchg */ /* * Atomic compare and exchange. */ #include #ifndef cmpxchg_local #define cmpxchg_local(ptr, o, n) ({ \ ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\ (unsigned long)(n), sizeof(*(ptr)))); \ }) #endif #ifndef cmpxchg64_local #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) #endif #define cmpxchg(ptr, o, n) cmpxchg_local((ptr), (o), (n)) #define cmpxchg64(ptr, o, n) cmpxchg64_local((ptr), (o), (n)) #endif /* __ASM_GENERIC_CMPXCHG_H */ a8e2'/>
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