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- /* SPDX-License-Identifier: GPL-2.0 */
- /*
- * This file provides wrappers with sanitizer instrumentation for bit
- * locking operations.
- *
- * To use this functionality, an arch's bitops.h file needs to define each of
- * the below bit operations with an arch_ prefix (e.g. arch_set_bit(),
- * arch___set_bit(), etc.).
- */
- #ifndef _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H
- #define _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H
- #include <linux/instrumented.h>
- /**
- * 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 inline void clear_bit_unlock(long nr, volatile unsigned long *addr)
- {
- kcsan_release();
- instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long));
- arch_clear_bit_unlock(nr, addr);
- }
- /**
- * __clear_bit_unlock - Clears a bit in memory
- * @nr: Bit to clear
- * @addr: Address to start counting from
- *
- * This is a non-atomic operation but implies a release barrier before the
- * memory operation. It can be used for an unlock if no other CPUs can
- * concurrently modify other bits in the word.
- */
- static inline void __clear_bit_unlock(long nr, volatile unsigned long *addr)
- {
- kcsan_release();
- instrument_write(addr + BIT_WORD(nr), sizeof(long));
- arch___clear_bit_unlock(nr, addr);
- }
- /**
- * 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 inline bool test_and_set_bit_lock(long nr, volatile unsigned long *addr)
- {
- instrument_atomic_read_write(addr + BIT_WORD(nr), sizeof(long));
- return arch_test_and_set_bit_lock(nr, addr);
- }
- #if defined(arch_clear_bit_unlock_is_negative_byte)
- /**
- * clear_bit_unlock_is_negative_byte - Clear a bit in memory and test if bottom
- * byte is negative, for unlock.
- * @nr: the bit to clear
- * @addr: the address to start counting from
- *
- * This operation is atomic and provides release barrier semantics.
- *
- * This is a bit of a one-trick-pony for the filemap code, which clears
- * PG_locked and tests PG_waiters,
- */
- static inline bool
- clear_bit_unlock_is_negative_byte(long nr, volatile unsigned long *addr)
- {
- kcsan_release();
- instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long));
- return arch_clear_bit_unlock_is_negative_byte(nr, addr);
- }
- /* Let everybody know we have it. */
- #define clear_bit_unlock_is_negative_byte clear_bit_unlock_is_negative_byte
- #endif
- #endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H */
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