1 /* SPDX-License-Identifier: GPL-2.0-only */
14  * Generic definitions for bit operations, should not be used in regular code
19  * generic___set_bit - Set a bit in memory
20  * @nr: the bit to set
23  * Unlike set_bit(), this function is non-atomic and may be reordered.
30 	unsigned long mask = BIT_MASK(nr);  in generic___set_bit()  local
33 	*p  |= mask;  in generic___set_bit()
39 	unsigned long mask = BIT_MASK(nr);  in generic___clear_bit()  local
42 	*p &= ~mask;  in generic___clear_bit()
46  * generic___change_bit - Toggle a bit in memory
47  * @nr: the bit to change
50  * Unlike change_bit(), this function is non-atomic and may be reordered.
57 	unsigned long mask = BIT_MASK(nr);  in generic___change_bit()  local
60 	*p ^= mask;  in generic___change_bit()
64  * generic___test_and_set_bit - Set a bit and return its old value
65  * @nr: Bit to set
68  * This operation is non-atomic and can be reordered.
75 	unsigned long mask = BIT_MASK(nr);  in generic___test_and_set_bit()  local
79 	*p = old | mask;  in generic___test_and_set_bit()
80 	return (old & mask) != 0;  in generic___test_and_set_bit()
84  * generic___test_and_clear_bit - Clear a bit and return its old value
85  * @nr: Bit to clear
88  * This operation is non-atomic and can be reordered.
95 	unsigned long mask = BIT_MASK(nr);  in generic___test_and_clear_bit()  local
99 	*p = old & ~mask;  in generic___test_and_clear_bit()
100 	return (old & mask) != 0;  in generic___test_and_clear_bit()
107 	unsigned long mask = BIT_MASK(nr);  in generic___test_and_change_bit()  local
111 	*p = old ^ mask;  in generic___test_and_change_bit()
112 	return (old & mask) != 0;  in generic___test_and_change_bit()
116  * generic_test_bit - Determine whether a bit is set
117  * @nr: bit number to test
125 	 * so `volatile` must always stay here with no cast-aways. See  in generic_test_bit()
128 	return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1)));  in generic_test_bit()
132  * generic_test_bit_acquire - Determine, with acquire semantics, whether a bit is set
133  * @nr: bit number to test
140 	return 1UL & (smp_load_acquire(p) >> (nr & (BITS_PER_LONG-1)));  in generic_test_bit_acquire()
144  * const_*() definitions provide good compile-time optimizations when
156  * const_test_bit - Determine whether a bit is set
157  * @nr: bit number to test
161  * allow a compiler to optimize code harder. Non-atomic and to be called only
162  * for testing compile-time constants, e.g. by the corresponding macros, not
169 	unsigned long mask = BIT_MASK(nr);  in const_test_bit()  local
172 	return !!(val & mask);  in const_test_bit()