ff5b4f1ed5
We'd like all architectures to convert to ARCH_ATOMIC, as once all
architectures are converted it will be possible to make significant
cleanups to the atomics headers, and this will make it much easier to
generically enable atomic functionality (e.g. debug logic in the
instrumented wrappers).
As a step towards that, this patch migrates sparc to ARCH_ATOMIC. The
arch code provides arch_{atomic,atomic64,xchg,cmpxchg}*(), and common
code wraps these with optional instrumentation to provide the regular
functions.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-31-mark.rutland@arm.com
81 lines
2.4 KiB
C
81 lines
2.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/* 32-bit atomic xchg() and cmpxchg() definitions.
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*
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* Copyright (C) 1996 David S. Miller (davem@davemloft.net)
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* Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com.au)
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* Copyright (C) 2007 Kyle McMartin (kyle@parisc-linux.org)
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*
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* Additions by Keith M Wesolowski (wesolows@foobazco.org) based
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* on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>.
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*/
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#ifndef __ARCH_SPARC_CMPXCHG__
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#define __ARCH_SPARC_CMPXCHG__
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unsigned long __xchg_u32(volatile u32 *m, u32 new);
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void __xchg_called_with_bad_pointer(void);
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static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr, 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(ptr, x);
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}
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__xchg_called_with_bad_pointer();
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return x;
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}
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#define arch_xchg(ptr,x) ({(__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)));})
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/* Emulate cmpxchg() the same way we emulate atomics,
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* by hashing the object address and indexing into an array
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* of spinlocks to get a bit of performance...
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*
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* See arch/sparc/lib/atomic32.c for implementation.
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*
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* Cribbed from <asm-parisc/atomic.h>
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*/
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/* bug catcher for when unsupported size is used - won't link */
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void __cmpxchg_called_with_bad_pointer(void);
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/* we only need to support cmpxchg of a u32 on sparc */
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unsigned long __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_);
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/* don't worry...optimizer will get rid of most of this */
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static inline unsigned long
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__cmpxchg(volatile void *ptr, unsigned long old, 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((u32 *)ptr, (u32)old, (u32)new_);
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default:
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__cmpxchg_called_with_bad_pointer();
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break;
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}
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return old;
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}
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#define arch_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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u64 __cmpxchg_u64(u64 *ptr, u64 old, u64 new);
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#define arch_cmpxchg64(ptr, old, new) __cmpxchg_u64(ptr, old, new)
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#include <asm-generic/cmpxchg-local.h>
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/*
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* cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
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* them available.
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*/
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#define arch_cmpxchg_local(ptr, o, n) \
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((__typeof__(*(ptr)))__generic_cmpxchg_local((ptr), (unsigned long)(o),\
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(unsigned long)(n), sizeof(*(ptr))))
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#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
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#endif /* __ARCH_SPARC_CMPXCHG__ */
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