532 lines
12 KiB
C
532 lines
12 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_POWERPC_CMPXCHG_H_
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#define _ASM_POWERPC_CMPXCHG_H_
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#ifdef __KERNEL__
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#include <linux/compiler.h>
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#include <asm/synch.h>
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#include <linux/bug.h>
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#ifdef __BIG_ENDIAN
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#define BITOFF_CAL(size, off) ((sizeof(u32) - size - off) * BITS_PER_BYTE)
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#else
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#define BITOFF_CAL(size, off) (off * BITS_PER_BYTE)
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#endif
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#define XCHG_GEN(type, sfx, cl) \
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static inline u32 __xchg_##type##sfx(volatile void *p, u32 val) \
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{ \
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unsigned int prev, prev_mask, tmp, bitoff, off; \
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\
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off = (unsigned long)p % sizeof(u32); \
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bitoff = BITOFF_CAL(sizeof(type), off); \
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p -= off; \
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val <<= bitoff; \
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prev_mask = (u32)(type)-1 << bitoff; \
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\
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__asm__ __volatile__( \
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"1: lwarx %0,0,%3\n" \
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" andc %1,%0,%5\n" \
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" or %1,%1,%4\n" \
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" stwcx. %1,0,%3\n" \
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" bne- 1b\n" \
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: "=&r" (prev), "=&r" (tmp), "+m" (*(u32*)p) \
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: "r" (p), "r" (val), "r" (prev_mask) \
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: "cc", cl); \
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\
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return prev >> bitoff; \
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}
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#define CMPXCHG_GEN(type, sfx, br, br2, cl) \
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static inline \
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u32 __cmpxchg_##type##sfx(volatile void *p, u32 old, u32 new) \
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{ \
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unsigned int prev, prev_mask, tmp, bitoff, off; \
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\
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off = (unsigned long)p % sizeof(u32); \
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bitoff = BITOFF_CAL(sizeof(type), off); \
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p -= off; \
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old <<= bitoff; \
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new <<= bitoff; \
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prev_mask = (u32)(type)-1 << bitoff; \
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\
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__asm__ __volatile__( \
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br \
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"1: lwarx %0,0,%3\n" \
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" and %1,%0,%6\n" \
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" cmpw 0,%1,%4\n" \
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" bne- 2f\n" \
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" andc %1,%0,%6\n" \
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" or %1,%1,%5\n" \
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" stwcx. %1,0,%3\n" \
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" bne- 1b\n" \
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br2 \
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"\n" \
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"2:" \
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: "=&r" (prev), "=&r" (tmp), "+m" (*(u32*)p) \
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: "r" (p), "r" (old), "r" (new), "r" (prev_mask) \
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: "cc", cl); \
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\
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return prev >> bitoff; \
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}
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/*
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* Atomic exchange
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*
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* Changes the memory location '*p' to be val and returns
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* the previous value stored there.
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*/
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XCHG_GEN(u8, _local, "memory");
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XCHG_GEN(u8, _relaxed, "cc");
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XCHG_GEN(u16, _local, "memory");
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XCHG_GEN(u16, _relaxed, "cc");
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static __always_inline unsigned long
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__xchg_u32_local(volatile void *p, unsigned long val)
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{
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unsigned long prev;
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__asm__ __volatile__(
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"1: lwarx %0,0,%2 \n"
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" stwcx. %3,0,%2 \n\
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bne- 1b"
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: "=&r" (prev), "+m" (*(volatile unsigned int *)p)
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: "r" (p), "r" (val)
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: "cc", "memory");
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return prev;
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}
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static __always_inline unsigned long
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__xchg_u32_relaxed(u32 *p, unsigned long val)
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{
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unsigned long prev;
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__asm__ __volatile__(
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"1: lwarx %0,0,%2\n"
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" stwcx. %3,0,%2\n"
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" bne- 1b"
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: "=&r" (prev), "+m" (*p)
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: "r" (p), "r" (val)
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: "cc");
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return prev;
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}
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#ifdef CONFIG_PPC64
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static __always_inline unsigned long
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__xchg_u64_local(volatile void *p, unsigned long val)
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{
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unsigned long prev;
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__asm__ __volatile__(
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"1: ldarx %0,0,%2 \n"
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" stdcx. %3,0,%2 \n\
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bne- 1b"
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: "=&r" (prev), "+m" (*(volatile unsigned long *)p)
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: "r" (p), "r" (val)
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: "cc", "memory");
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return prev;
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}
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static __always_inline unsigned long
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__xchg_u64_relaxed(u64 *p, unsigned long val)
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{
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unsigned long prev;
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__asm__ __volatile__(
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"1: ldarx %0,0,%2\n"
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" stdcx. %3,0,%2\n"
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" bne- 1b"
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: "=&r" (prev), "+m" (*p)
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: "r" (p), "r" (val)
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: "cc");
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return prev;
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}
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#endif
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static __always_inline unsigned long
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__xchg_local(void *ptr, unsigned long x, unsigned int size)
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{
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switch (size) {
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case 1:
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return __xchg_u8_local(ptr, x);
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case 2:
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return __xchg_u16_local(ptr, x);
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case 4:
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return __xchg_u32_local(ptr, x);
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#ifdef CONFIG_PPC64
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case 8:
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return __xchg_u64_local(ptr, x);
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#endif
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}
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BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg");
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return x;
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}
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static __always_inline unsigned long
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__xchg_relaxed(void *ptr, unsigned long x, unsigned int size)
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{
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switch (size) {
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case 1:
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return __xchg_u8_relaxed(ptr, x);
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case 2:
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return __xchg_u16_relaxed(ptr, x);
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case 4:
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return __xchg_u32_relaxed(ptr, x);
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#ifdef CONFIG_PPC64
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case 8:
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return __xchg_u64_relaxed(ptr, x);
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#endif
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}
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BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg_local");
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return x;
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}
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#define xchg_local(ptr,x) \
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({ \
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__typeof__(*(ptr)) _x_ = (x); \
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(__typeof__(*(ptr))) __xchg_local((ptr), \
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(unsigned long)_x_, sizeof(*(ptr))); \
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})
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#define xchg_relaxed(ptr, x) \
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({ \
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__typeof__(*(ptr)) _x_ = (x); \
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(__typeof__(*(ptr))) __xchg_relaxed((ptr), \
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(unsigned long)_x_, sizeof(*(ptr))); \
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})
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/*
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* Compare and exchange - if *p == old, set it to new,
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* and return the old value of *p.
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*/
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CMPXCHG_GEN(u8, , PPC_ATOMIC_ENTRY_BARRIER, PPC_ATOMIC_EXIT_BARRIER, "memory");
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CMPXCHG_GEN(u8, _local, , , "memory");
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CMPXCHG_GEN(u8, _acquire, , PPC_ACQUIRE_BARRIER, "memory");
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CMPXCHG_GEN(u8, _relaxed, , , "cc");
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CMPXCHG_GEN(u16, , PPC_ATOMIC_ENTRY_BARRIER, PPC_ATOMIC_EXIT_BARRIER, "memory");
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CMPXCHG_GEN(u16, _local, , , "memory");
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CMPXCHG_GEN(u16, _acquire, , PPC_ACQUIRE_BARRIER, "memory");
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CMPXCHG_GEN(u16, _relaxed, , , "cc");
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static __always_inline unsigned long
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__cmpxchg_u32(volatile unsigned int *p, unsigned long old, unsigned long new)
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{
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unsigned int prev;
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__asm__ __volatile__ (
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PPC_ATOMIC_ENTRY_BARRIER
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"1: lwarx %0,0,%2 # __cmpxchg_u32\n\
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cmpw 0,%0,%3\n\
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bne- 2f\n"
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" stwcx. %4,0,%2\n\
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bne- 1b"
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PPC_ATOMIC_EXIT_BARRIER
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"\n\
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2:"
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: "=&r" (prev), "+m" (*p)
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: "r" (p), "r" (old), "r" (new)
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: "cc", "memory");
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return prev;
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}
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static __always_inline unsigned long
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__cmpxchg_u32_local(volatile unsigned int *p, unsigned long old,
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unsigned long new)
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{
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unsigned int prev;
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__asm__ __volatile__ (
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"1: lwarx %0,0,%2 # __cmpxchg_u32\n\
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cmpw 0,%0,%3\n\
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bne- 2f\n"
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" stwcx. %4,0,%2\n\
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bne- 1b"
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"\n\
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2:"
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: "=&r" (prev), "+m" (*p)
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: "r" (p), "r" (old), "r" (new)
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: "cc", "memory");
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return prev;
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}
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static __always_inline unsigned long
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__cmpxchg_u32_relaxed(u32 *p, unsigned long old, unsigned long new)
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{
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unsigned long prev;
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__asm__ __volatile__ (
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"1: lwarx %0,0,%2 # __cmpxchg_u32_relaxed\n"
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" cmpw 0,%0,%3\n"
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" bne- 2f\n"
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" stwcx. %4,0,%2\n"
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" bne- 1b\n"
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"2:"
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: "=&r" (prev), "+m" (*p)
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: "r" (p), "r" (old), "r" (new)
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: "cc");
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return prev;
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}
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/*
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* cmpxchg family don't have order guarantee if cmp part fails, therefore we
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* can avoid superfluous barriers if we use assembly code to implement
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* cmpxchg() and cmpxchg_acquire(), however we don't do the similar for
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* cmpxchg_release() because that will result in putting a barrier in the
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* middle of a ll/sc loop, which is probably a bad idea. For example, this
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* might cause the conditional store more likely to fail.
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*/
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static __always_inline unsigned long
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__cmpxchg_u32_acquire(u32 *p, unsigned long old, unsigned long new)
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{
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unsigned long prev;
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__asm__ __volatile__ (
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"1: lwarx %0,0,%2 # __cmpxchg_u32_acquire\n"
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" cmpw 0,%0,%3\n"
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" bne- 2f\n"
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" stwcx. %4,0,%2\n"
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" bne- 1b\n"
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PPC_ACQUIRE_BARRIER
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"\n"
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"2:"
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: "=&r" (prev), "+m" (*p)
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: "r" (p), "r" (old), "r" (new)
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: "cc", "memory");
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return prev;
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}
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#ifdef CONFIG_PPC64
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static __always_inline unsigned long
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__cmpxchg_u64(volatile unsigned long *p, unsigned long old, unsigned long new)
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{
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unsigned long prev;
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__asm__ __volatile__ (
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PPC_ATOMIC_ENTRY_BARRIER
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"1: ldarx %0,0,%2 # __cmpxchg_u64\n\
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cmpd 0,%0,%3\n\
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bne- 2f\n\
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stdcx. %4,0,%2\n\
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bne- 1b"
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PPC_ATOMIC_EXIT_BARRIER
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"\n\
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2:"
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: "=&r" (prev), "+m" (*p)
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: "r" (p), "r" (old), "r" (new)
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: "cc", "memory");
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return prev;
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}
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static __always_inline unsigned long
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__cmpxchg_u64_local(volatile unsigned long *p, unsigned long old,
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unsigned long new)
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{
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unsigned long prev;
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__asm__ __volatile__ (
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"1: ldarx %0,0,%2 # __cmpxchg_u64\n\
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cmpd 0,%0,%3\n\
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bne- 2f\n\
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stdcx. %4,0,%2\n\
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bne- 1b"
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"\n\
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2:"
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: "=&r" (prev), "+m" (*p)
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: "r" (p), "r" (old), "r" (new)
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: "cc", "memory");
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return prev;
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}
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static __always_inline unsigned long
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__cmpxchg_u64_relaxed(u64 *p, unsigned long old, unsigned long new)
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{
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unsigned long prev;
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__asm__ __volatile__ (
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"1: ldarx %0,0,%2 # __cmpxchg_u64_relaxed\n"
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" cmpd 0,%0,%3\n"
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" bne- 2f\n"
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" stdcx. %4,0,%2\n"
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" bne- 1b\n"
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"2:"
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: "=&r" (prev), "+m" (*p)
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: "r" (p), "r" (old), "r" (new)
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: "cc");
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return prev;
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}
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static __always_inline unsigned long
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__cmpxchg_u64_acquire(u64 *p, unsigned long old, unsigned long new)
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{
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unsigned long prev;
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__asm__ __volatile__ (
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"1: ldarx %0,0,%2 # __cmpxchg_u64_acquire\n"
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" cmpd 0,%0,%3\n"
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" bne- 2f\n"
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" stdcx. %4,0,%2\n"
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" bne- 1b\n"
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PPC_ACQUIRE_BARRIER
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"\n"
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"2:"
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: "=&r" (prev), "+m" (*p)
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: "r" (p), "r" (old), "r" (new)
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: "cc", "memory");
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return prev;
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}
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#endif
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static __always_inline unsigned long
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__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new,
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unsigned int size)
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{
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switch (size) {
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case 1:
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return __cmpxchg_u8(ptr, old, new);
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case 2:
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return __cmpxchg_u16(ptr, old, new);
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case 4:
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return __cmpxchg_u32(ptr, old, new);
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#ifdef CONFIG_PPC64
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case 8:
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return __cmpxchg_u64(ptr, old, new);
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#endif
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}
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BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg");
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return old;
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}
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static __always_inline unsigned long
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__cmpxchg_local(void *ptr, unsigned long old, unsigned long new,
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unsigned int size)
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{
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switch (size) {
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case 1:
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return __cmpxchg_u8_local(ptr, old, new);
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case 2:
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return __cmpxchg_u16_local(ptr, old, new);
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case 4:
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return __cmpxchg_u32_local(ptr, old, new);
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#ifdef CONFIG_PPC64
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case 8:
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return __cmpxchg_u64_local(ptr, old, new);
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#endif
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}
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BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg_local");
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return old;
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}
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static __always_inline unsigned long
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__cmpxchg_relaxed(void *ptr, unsigned long old, unsigned long new,
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unsigned int size)
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{
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switch (size) {
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case 1:
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return __cmpxchg_u8_relaxed(ptr, old, new);
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case 2:
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return __cmpxchg_u16_relaxed(ptr, old, new);
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case 4:
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return __cmpxchg_u32_relaxed(ptr, old, new);
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#ifdef CONFIG_PPC64
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case 8:
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return __cmpxchg_u64_relaxed(ptr, old, new);
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#endif
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}
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BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg_relaxed");
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return old;
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}
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static __always_inline unsigned long
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__cmpxchg_acquire(void *ptr, unsigned long old, unsigned long new,
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unsigned int size)
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{
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switch (size) {
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case 1:
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return __cmpxchg_u8_acquire(ptr, old, new);
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case 2:
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return __cmpxchg_u16_acquire(ptr, old, new);
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case 4:
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return __cmpxchg_u32_acquire(ptr, old, new);
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#ifdef CONFIG_PPC64
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case 8:
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return __cmpxchg_u64_acquire(ptr, old, new);
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#endif
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}
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BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg_acquire");
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return old;
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}
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#define cmpxchg(ptr, o, n) \
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({ \
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__typeof__(*(ptr)) _o_ = (o); \
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__typeof__(*(ptr)) _n_ = (n); \
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(__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
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(unsigned long)_n_, sizeof(*(ptr))); \
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})
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#define cmpxchg_local(ptr, o, n) \
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({ \
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__typeof__(*(ptr)) _o_ = (o); \
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__typeof__(*(ptr)) _n_ = (n); \
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(__typeof__(*(ptr))) __cmpxchg_local((ptr), (unsigned long)_o_, \
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(unsigned long)_n_, sizeof(*(ptr))); \
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})
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#define cmpxchg_relaxed(ptr, o, n) \
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({ \
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__typeof__(*(ptr)) _o_ = (o); \
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__typeof__(*(ptr)) _n_ = (n); \
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(__typeof__(*(ptr))) __cmpxchg_relaxed((ptr), \
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(unsigned long)_o_, (unsigned long)_n_, \
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sizeof(*(ptr))); \
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})
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#define cmpxchg_acquire(ptr, o, n) \
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({ \
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__typeof__(*(ptr)) _o_ = (o); \
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|
__typeof__(*(ptr)) _n_ = (n); \
|
|
(__typeof__(*(ptr))) __cmpxchg_acquire((ptr), \
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|
(unsigned long)_o_, (unsigned long)_n_, \
|
|
sizeof(*(ptr))); \
|
|
})
|
|
#ifdef CONFIG_PPC64
|
|
#define cmpxchg64(ptr, o, n) \
|
|
({ \
|
|
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
|
|
cmpxchg((ptr), (o), (n)); \
|
|
})
|
|
#define cmpxchg64_local(ptr, o, n) \
|
|
({ \
|
|
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
|
|
cmpxchg_local((ptr), (o), (n)); \
|
|
})
|
|
#define cmpxchg64_relaxed(ptr, o, n) \
|
|
({ \
|
|
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
|
|
cmpxchg_relaxed((ptr), (o), (n)); \
|
|
})
|
|
#define cmpxchg64_acquire(ptr, o, n) \
|
|
({ \
|
|
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
|
|
cmpxchg_acquire((ptr), (o), (n)); \
|
|
})
|
|
#else
|
|
#include <asm-generic/cmpxchg-local.h>
|
|
#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
|
|
#endif
|
|
|
|
#endif /* __KERNEL__ */
|
|
#endif /* _ASM_POWERPC_CMPXCHG_H_ */
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