1 /* SPDX-License-Identifier: GPL-2.0 */
6  * Linux wait-bit related types and methods:
21 #define __WAIT_BIT_KEY_INITIALIZER(word, bit)					\  argument
22 	{ .flags = word, .bit_nr = bit, }
26 void __wake_up_bit(struct wait_queue_head *wq_head, void *word, int bit);
29 void wake_up_bit(void *word, int bit);
33 struct wait_queue_head *bit_waitqueue(void *word, int bit);
38 #define DEFINE_WAIT_BIT(name, word, bit)					\  argument
40 		.key = __WAIT_BIT_KEY_INITIALIZER(word, bit),			\
55  * wait_on_bit - wait for a bit to be cleared
56  * @word: the word being waited on, a kernel virtual address
57  * @bit: the bit of the word being waited on
60  * There is a standard hashed waitqueue table for generic use. This
61  * is the part of the hashtable's accessor API that waits on a bit.
62  * For instance, if one were to have waiters on a bitflag, one would
63  * call wait_on_bit() in threads waiting for the bit to clear.
64  * One uses wait_on_bit() where one is waiting for the bit to clear,
66  * Returned value will be zero if the bit was cleared, or non-zero
67  * if the process received a signal and the mode permitted wakeup
71 wait_on_bit(unsigned long *word, int bit, unsigned mode)  in wait_on_bit()  argument
74 	if (!test_bit_acquire(bit, word))  in wait_on_bit()
76 	return out_of_line_wait_on_bit(word, bit,  in wait_on_bit()
82  * wait_on_bit_io - wait for a bit to be cleared
83  * @word: the word being waited on, a kernel virtual address
84  * @bit: the bit of the word being waited on
87  * Use the standard hashed waitqueue table to wait for a bit
91  * Returned value will be zero if the bit was cleared, or non-zero
92  * if the process received a signal and the mode permitted wakeup
96 wait_on_bit_io(unsigned long *word, int bit, unsigned mode)  in wait_on_bit_io()  argument
99 	if (!test_bit_acquire(bit, word))  in wait_on_bit_io()
101 	return out_of_line_wait_on_bit(word, bit,  in wait_on_bit_io()
107  * wait_on_bit_timeout - wait for a bit to be cleared or a timeout elapses
108  * @word: the word being waited on, a kernel virtual address
109  * @bit: the bit of the word being waited on
113  * Use the standard hashed waitqueue table to wait for a bit
114  * to be cleared. This is similar to wait_on_bit(), except also takes a
117  * Returned value will be zero if the bit was cleared before the
118  * @timeout elapsed, or non-zero if the @timeout elapsed or process
119  * received a signal and the mode permitted wakeup on that signal.
122 wait_on_bit_timeout(unsigned long *word, int bit, unsigned mode,  in wait_on_bit_timeout()  argument
126 	if (!test_bit_acquire(bit, word))  in wait_on_bit_timeout()
128 	return out_of_line_wait_on_bit_timeout(word, bit,  in wait_on_bit_timeout()
134  * wait_on_bit_action - wait for a bit to be cleared
135  * @word: the word being waited on, a kernel virtual address
136  * @bit: the bit of the word being waited on
140  * Use the standard hashed waitqueue table to wait for a bit
145  * Returned value will be zero if the bit was cleared, or non-zero
146  * if the process received a signal and the mode permitted wakeup
150 wait_on_bit_action(unsigned long *word, int bit, wait_bit_action_f *action,  in wait_on_bit_action()  argument
154 	if (!test_bit_acquire(bit, word))  in wait_on_bit_action()
156 	return out_of_line_wait_on_bit(word, bit, action, mode);  in wait_on_bit_action()
160  * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
161  * @word: the word being waited on, a kernel virtual address
162  * @bit: the bit of the word being waited on
165  * There is a standard hashed waitqueue table for generic use. This
166  * is the part of the hashtable's accessor API that waits on a bit
170  * wait_on_bit() in threads waiting to be able to set the bit.
171  * One uses wait_on_bit_lock() where one is waiting for the bit to
174  * Returns zero if the bit was (eventually) found to be clear and was
175  * set.  Returns non-zero if a signal was delivered to the process and
179 wait_on_bit_lock(unsigned long *word, int bit, unsigned mode)  in wait_on_bit_lock()  argument
182 	if (!test_and_set_bit(bit, word))  in wait_on_bit_lock()
184 	return out_of_line_wait_on_bit_lock(word, bit, bit_wait, mode);  in wait_on_bit_lock()
188  * wait_on_bit_lock_io - wait for a bit to be cleared, when wanting to set it
189  * @word: the word being waited on, a kernel virtual address
190  * @bit: the bit of the word being waited on
193  * Use the standard hashed waitqueue table to wait for a bit
198  * Returns zero if the bit was (eventually) found to be clear and was
199  * set.  Returns non-zero if a signal was delivered to the process and
203 wait_on_bit_lock_io(unsigned long *word, int bit, unsigned mode)  in wait_on_bit_lock_io()  argument
206 	if (!test_and_set_bit(bit, word))  in wait_on_bit_lock_io()
208 	return out_of_line_wait_on_bit_lock(word, bit, bit_wait_io, mode);  in wait_on_bit_lock_io()
212  * wait_on_bit_lock_action - wait for a bit to be cleared, when wanting to set it
213  * @word: the word being waited on, a kernel virtual address
214  * @bit: the bit of the word being waited on
218  * Use the standard hashed waitqueue table to wait for a bit
224  * Returns zero if the bit was (eventually) found to be clear and was
225  * set.  Returns non-zero if a signal was delivered to the process and
229 wait_on_bit_lock_action(unsigned long *word, int bit, wait_bit_action_f *action,  in wait_on_bit_lock_action()  argument
233 	if (!test_and_set_bit(bit, word))  in wait_on_bit_lock_action()
235 	return out_of_line_wait_on_bit_lock(word, bit, action, mode);  in wait_on_bit_lock_action()
322  * clear_and_wake_up_bit - clear a bit and wake up anyone waiting on that bit
324  * @bit: the bit of the word being waited on
325  * @word: the word being waited on, a kernel virtual address
328  * non-atomically under a lock.
330 static inline void clear_and_wake_up_bit(int bit, void *word)  in clear_and_wake_up_bit()  argument
332 	clear_bit_unlock(bit, word);  in clear_and_wake_up_bit()
335 	wake_up_bit(word, bit);  in clear_and_wake_up_bit()