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329c161b8b
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 parisc 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: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Helge Deller <deller@gmx.de>
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/20210525140232.53872-27-mark.rutland@arm.com
124 lines
3.7 KiB
C
124 lines
3.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* forked from parisc asm/atomic.h which was:
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* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
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* Copyright (C) 2006 Kyle McMartin <kyle@parisc-linux.org>
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*/
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#ifndef _ASM_PARISC_CMPXCHG_H_
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#define _ASM_PARISC_CMPXCHG_H_
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/* This should get optimized out since it's never called.
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** Or get a link error if xchg is used "wrong".
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*/
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extern void __xchg_called_with_bad_pointer(void);
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/* __xchg32/64 defined in arch/parisc/lib/bitops.c */
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extern unsigned long __xchg8(char, volatile char *);
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extern unsigned long __xchg32(int, volatile int *);
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#ifdef CONFIG_64BIT
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extern unsigned long __xchg64(unsigned long, volatile unsigned long *);
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#endif
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/* optimizer better get rid of switch since size is a constant */
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static inline unsigned long
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__xchg(unsigned long x, volatile void *ptr, int size)
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{
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switch (size) {
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#ifdef CONFIG_64BIT
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case 8: return __xchg64(x, (volatile unsigned long *) ptr);
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#endif
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case 4: return __xchg32((int) x, (volatile int *) ptr);
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case 1: return __xchg8((char) x, (volatile char *) ptr);
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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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/*
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** REVISIT - Abandoned use of LDCW in xchg() for now:
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** o need to test sizeof(*ptr) to avoid clearing adjacent bytes
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** o and while we are at it, could CONFIG_64BIT code use LDCD too?
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**
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** if (__builtin_constant_p(x) && (x == NULL))
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** if (((unsigned long)p & 0xf) == 0)
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** return __ldcw(p);
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*/
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#define arch_xchg(ptr, x) \
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({ \
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__typeof__(*(ptr)) __ret; \
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__typeof__(*(ptr)) _x_ = (x); \
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__ret = (__typeof__(*(ptr))) \
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__xchg((unsigned long)_x_, (ptr), sizeof(*(ptr))); \
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__ret; \
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})
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/* bug catcher for when unsupported size is used - won't link */
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extern void __cmpxchg_called_with_bad_pointer(void);
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/* __cmpxchg_u32/u64 defined in arch/parisc/lib/bitops.c */
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extern unsigned long __cmpxchg_u32(volatile unsigned int *m, unsigned int old,
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unsigned int new_);
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extern u64 __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new_);
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extern u8 __cmpxchg_u8(volatile u8 *ptr, u8 old, u8 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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#ifdef CONFIG_64BIT
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case 8: return __cmpxchg_u64((u64 *)ptr, old, new_);
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#endif
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case 4: return __cmpxchg_u32((unsigned int *)ptr,
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(unsigned int)old, (unsigned int)new_);
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case 1: return __cmpxchg_u8((u8 *)ptr, old & 0xff, new_ & 0xff);
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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 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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#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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#ifdef CONFIG_64BIT
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case 8: return __cmpxchg_u64((u64 *)ptr, old, new_);
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#endif
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case 4: return __cmpxchg_u32(ptr, old, new_);
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default:
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return __generic_cmpxchg_local(ptr, old, new_, size);
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}
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}
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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)))__cmpxchg_local((ptr), (unsigned long)(o), \
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(unsigned long)(n), sizeof(*(ptr))))
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#ifdef CONFIG_64BIT
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#define arch_cmpxchg64_local(ptr, o, n) \
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({ \
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BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
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cmpxchg_local((ptr), (o), (n)); \
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})
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#else
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#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
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#endif
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#define arch_cmpxchg64(ptr, o, n) __cmpxchg_u64(ptr, o, n)
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#endif /* _ASM_PARISC_CMPXCHG_H_ */
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