1/* SPDX-License-Identifier: GPL-2.0 */
 2
 3/*
 4 * This file provides wrappers with sanitizer instrumentation for bit
 5 * locking operations.
 6 *
 7 * To use this functionality, an arch's bitops.h file needs to define each of
 8 * the below bit operations with an arch_ prefix (e.g. arch_set_bit(),
 9 * arch___set_bit(), etc.).
10 */
11#ifndef _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H
12#define _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H
13
14#include <linux/instrumented.h>
15
16/**
17 * clear_bit_unlock - Clear a bit in memory, for unlock
18 * @nr: the bit to set
19 * @addr: the address to start counting from
20 *
21 * This operation is atomic and provides release barrier semantics.
22 */
23static inline void clear_bit_unlock(long nr, volatile unsigned long *addr)
24{
25	kcsan_release();
26	instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long));
27	arch_clear_bit_unlock(nr, addr);
28}
29
30/**
31 * __clear_bit_unlock - Clears a bit in memory
32 * @nr: Bit to clear
33 * @addr: Address to start counting from
34 *
35 * This is a non-atomic operation but implies a release barrier before the
36 * memory operation. It can be used for an unlock if no other CPUs can
37 * concurrently modify other bits in the word.
38 */
39static inline void __clear_bit_unlock(long nr, volatile unsigned long *addr)
40{
41	kcsan_release();
42	instrument_write(addr + BIT_WORD(nr), sizeof(long));
43	arch___clear_bit_unlock(nr, addr);
44}
45
46/**
47 * test_and_set_bit_lock - Set a bit and return its old value, for lock
48 * @nr: Bit to set
49 * @addr: Address to count from
50 *
51 * This operation is atomic and provides acquire barrier semantics if
52 * the returned value is 0.
53 * It can be used to implement bit locks.
54 */
55static inline bool test_and_set_bit_lock(long nr, volatile unsigned long *addr)
56{
57	instrument_atomic_read_write(addr + BIT_WORD(nr), sizeof(long));
58	return arch_test_and_set_bit_lock(nr, addr);
59}
60
 
61/**
62 * xor_unlock_is_negative_byte - XOR a single byte in memory and test if
63 * it is negative, for unlock.
64 * @mask: Change the bits which are set in this mask.
65 * @addr: The address of the word containing the byte to change.
66 *
67 * Changes some of bits 0-6 in the word pointed to by @addr.
68 * This operation is atomic and provides release barrier semantics.
69 * Used to optimise some folio operations which are commonly paired
70 * with an unlock or end of writeback.  Bit 7 is used as PG_waiters to
71 * indicate whether anybody is waiting for the unlock.
72 *
73 * Return: Whether the top bit of the byte is set.
 
74 */
75static inline bool xor_unlock_is_negative_byte(unsigned long mask,
76		volatile unsigned long *addr)
77{
78	kcsan_release();
79	instrument_atomic_write(addr, sizeof(long));
80	return arch_xor_unlock_is_negative_byte(mask, addr);
81}
 
 
 
 
82#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H */

 1/* SPDX-License-Identifier: GPL-2.0 */
 2
 3/*
 4 * This file provides wrappers with sanitizer instrumentation for bit
 5 * locking operations.
 6 *
 7 * To use this functionality, an arch's bitops.h file needs to define each of
 8 * the below bit operations with an arch_ prefix (e.g. arch_set_bit(),
 9 * arch___set_bit(), etc.).
10 */
11#ifndef _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H
12#define _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H
13
14#include <linux/instrumented.h>
15
16/**
17 * clear_bit_unlock - Clear a bit in memory, for unlock
18 * @nr: the bit to set
19 * @addr: the address to start counting from
20 *
21 * This operation is atomic and provides release barrier semantics.
22 */
23static inline void clear_bit_unlock(long nr, volatile unsigned long *addr)
24{
 
25	instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long));
26	arch_clear_bit_unlock(nr, addr);
27}
28
29/**
30 * __clear_bit_unlock - Clears a bit in memory
31 * @nr: Bit to clear
32 * @addr: Address to start counting from
33 *
34 * This is a non-atomic operation but implies a release barrier before the
35 * memory operation. It can be used for an unlock if no other CPUs can
36 * concurrently modify other bits in the word.
37 */
38static inline void __clear_bit_unlock(long nr, volatile unsigned long *addr)
39{
 
40	instrument_write(addr + BIT_WORD(nr), sizeof(long));
41	arch___clear_bit_unlock(nr, addr);
42}
43
44/**
45 * test_and_set_bit_lock - Set a bit and return its old value, for lock
46 * @nr: Bit to set
47 * @addr: Address to count from
48 *
49 * This operation is atomic and provides acquire barrier semantics if
50 * the returned value is 0.
51 * It can be used to implement bit locks.
52 */
53static inline bool test_and_set_bit_lock(long nr, volatile unsigned long *addr)
54{
55	instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long));
56	return arch_test_and_set_bit_lock(nr, addr);
57}
58
59#if defined(arch_clear_bit_unlock_is_negative_byte)
60/**
61 * clear_bit_unlock_is_negative_byte - Clear a bit in memory and test if bottom
62 *                                     byte is negative, for unlock.
63 * @nr: the bit to clear
64 * @addr: the address to start counting from
65 *
 
66 * This operation is atomic and provides release barrier semantics.
 
 
 
67 *
68 * This is a bit of a one-trick-pony for the filemap code, which clears
69 * PG_locked and tests PG_waiters,
70 */
71static inline bool
72clear_bit_unlock_is_negative_byte(long nr, volatile unsigned long *addr)
73{
74	instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long));
75	return arch_clear_bit_unlock_is_negative_byte(nr, addr);
 
76}
77/* Let everybody know we have it. */
78#define clear_bit_unlock_is_negative_byte clear_bit_unlock_is_negative_byte
79#endif
80
81#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H */