118 lines
2.8 KiB
C
118 lines
2.8 KiB
C
/*
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* Atomic operations that C can't guarantee us. Useful for
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* resource counting etc.
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*
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* But use these as seldom as possible since they are slower than
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* regular operations.
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*
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* Copyright (C) 2004-2006 Atmel Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef __ASM_AVR32_CMPXCHG_H
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#define __ASM_AVR32_CMPXCHG_H
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#define xchg(ptr,x) \
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((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
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extern void __xchg_called_with_bad_pointer(void);
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static inline unsigned long xchg_u32(u32 val, volatile u32 *m)
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{
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u32 ret;
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asm volatile("xchg %[ret], %[m], %[val]"
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: [ret] "=&r"(ret), "=m"(*m)
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: "m"(*m), [m] "r"(m), [val] "r"(val)
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: "memory");
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return ret;
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}
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static inline unsigned long __xchg(unsigned long x,
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volatile void *ptr,
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int size)
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{
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switch(size) {
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case 4:
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return xchg_u32(x, ptr);
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default:
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__xchg_called_with_bad_pointer();
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return x;
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}
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}
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static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old,
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unsigned long new)
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{
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__u32 ret;
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asm volatile(
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"1: ssrf 5\n"
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" ld.w %[ret], %[m]\n"
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" cp.w %[ret], %[old]\n"
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" brne 2f\n"
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" stcond %[m], %[new]\n"
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" brne 1b\n"
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"2:\n"
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: [ret] "=&r"(ret), [m] "=m"(*m)
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: "m"(m), [old] "ir"(old), [new] "r"(new)
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: "memory", "cc");
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return ret;
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}
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extern unsigned long __cmpxchg_u64_unsupported_on_32bit_kernels(
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volatile int * m, unsigned long old, unsigned long new);
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#define __cmpxchg_u64 __cmpxchg_u64_unsupported_on_32bit_kernels
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/* This function doesn't exist, so you'll get a linker error
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if something tries to do an invalid cmpxchg(). */
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extern void __cmpxchg_called_with_bad_pointer(void);
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#define __HAVE_ARCH_CMPXCHG 1
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static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
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unsigned long new, int size)
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{
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switch (size) {
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case 4:
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return __cmpxchg_u32(ptr, old, new);
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case 8:
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return __cmpxchg_u64(ptr, old, new);
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}
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__cmpxchg_called_with_bad_pointer();
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return old;
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}
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#define cmpxchg(ptr, old, new) \
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((typeof(*(ptr)))__cmpxchg((ptr), (unsigned long)(old), \
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(unsigned long)(new), \
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sizeof(*(ptr))))
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#include <asm-generic/cmpxchg-local.h>
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static inline unsigned long __cmpxchg_local(volatile void *ptr,
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unsigned long old,
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unsigned long new, int size)
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{
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switch (size) {
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case 4:
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return __cmpxchg_u32(ptr, old, new);
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default:
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return __cmpxchg_local_generic(ptr, old, new, size);
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}
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return old;
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}
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#define cmpxchg_local(ptr, old, new) \
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((typeof(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(old), \
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(unsigned long)(new), \
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sizeof(*(ptr))))
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#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
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#endif /* __ASM_AVR32_CMPXCHG_H */
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