mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-28 21:33:52 +00:00
f12fb73b74
Architectures which don't define their own use the one in asm-generic/bitops/lock.h. Get rid of all the ifdefs around "maybe we don't have it". Link: https://lkml.kernel.org/r/20231004165317.1061855-15-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Henderson <richard.henderson@linaro.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
82 lines
2.1 KiB
C
82 lines
2.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _ASM_GENERIC_BITOPS_LOCK_H_
|
|
#define _ASM_GENERIC_BITOPS_LOCK_H_
|
|
|
|
#include <linux/atomic.h>
|
|
#include <linux/compiler.h>
|
|
#include <asm/barrier.h>
|
|
|
|
/**
|
|
* arch_test_and_set_bit_lock - Set a bit and return its old value, for lock
|
|
* @nr: Bit to set
|
|
* @addr: Address to count from
|
|
*
|
|
* This operation is atomic and provides acquire barrier semantics if
|
|
* the returned value is 0.
|
|
* It can be used to implement bit locks.
|
|
*/
|
|
static __always_inline int
|
|
arch_test_and_set_bit_lock(unsigned int nr, volatile unsigned long *p)
|
|
{
|
|
long old;
|
|
unsigned long mask = BIT_MASK(nr);
|
|
|
|
p += BIT_WORD(nr);
|
|
if (READ_ONCE(*p) & mask)
|
|
return 1;
|
|
|
|
old = raw_atomic_long_fetch_or_acquire(mask, (atomic_long_t *)p);
|
|
return !!(old & mask);
|
|
}
|
|
|
|
|
|
/**
|
|
* arch_clear_bit_unlock - Clear a bit in memory, for unlock
|
|
* @nr: the bit to set
|
|
* @addr: the address to start counting from
|
|
*
|
|
* This operation is atomic and provides release barrier semantics.
|
|
*/
|
|
static __always_inline void
|
|
arch_clear_bit_unlock(unsigned int nr, volatile unsigned long *p)
|
|
{
|
|
p += BIT_WORD(nr);
|
|
raw_atomic_long_fetch_andnot_release(BIT_MASK(nr), (atomic_long_t *)p);
|
|
}
|
|
|
|
/**
|
|
* arch___clear_bit_unlock - Clear a bit in memory, for unlock
|
|
* @nr: the bit to set
|
|
* @addr: the address to start counting from
|
|
*
|
|
* A weaker form of clear_bit_unlock() as used by __bit_lock_unlock(). If all
|
|
* the bits in the word are protected by this lock some archs can use weaker
|
|
* ops to safely unlock.
|
|
*
|
|
* See for example x86's implementation.
|
|
*/
|
|
static inline void
|
|
arch___clear_bit_unlock(unsigned int nr, volatile unsigned long *p)
|
|
{
|
|
unsigned long old;
|
|
|
|
p += BIT_WORD(nr);
|
|
old = READ_ONCE(*p);
|
|
old &= ~BIT_MASK(nr);
|
|
raw_atomic_long_set_release((atomic_long_t *)p, old);
|
|
}
|
|
|
|
#ifndef arch_xor_unlock_is_negative_byte
|
|
static inline bool arch_xor_unlock_is_negative_byte(unsigned long mask,
|
|
volatile unsigned long *p)
|
|
{
|
|
long old;
|
|
|
|
old = raw_atomic_long_fetch_xor_release(mask, (atomic_long_t *)p);
|
|
return !!(old & BIT(7));
|
|
}
|
|
#endif
|
|
|
|
#include <asm-generic/bitops/instrumented-lock.h>
|
|
|
|
#endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */
|