/*
* The implementation of the wait_bit*() and related waiting APIs:
*/
-#include <linux/wait_bit.h>
-#include <linux/sched/signal.h>
-#include <linux/sched/debug.h>
-#include <linux/hash.h>
+#include "sched.h"
#define WAIT_TABLE_BITS 8
#define WAIT_TABLE_SIZE (1 << WAIT_TABLE_BITS)
wait_bit->key.bit_nr != key->bit_nr ||
test_bit(key->bit_nr, key->flags))
return 0;
- else
- return autoremove_wake_function(wq_entry, mode, sync, key);
+
+ return autoremove_wake_function(wq_entry, mode, sync, key);
}
EXPORT_SYMBOL(wake_bit_function);
if (test_bit(wbq_entry->key.bit_nr, wbq_entry->key.flags))
ret = (*action)(&wbq_entry->key, mode);
} while (test_bit(wbq_entry->key.bit_nr, wbq_entry->key.flags) && !ret);
+
finish_wait(wq_head, &wbq_entry->wq_entry);
+
return ret;
}
EXPORT_SYMBOL(__wait_on_bit);
DEFINE_WAIT_BIT(wq_entry, word, bit);
wq_entry.key.timeout = jiffies + timeout;
+
return __wait_on_bit(wq_head, &wq_entry, action, mode);
}
EXPORT_SYMBOL_GPL(out_of_line_wait_on_bit_timeout);
void __wake_up_bit(struct wait_queue_head *wq_head, void *word, int bit)
{
struct wait_bit_key key = __WAIT_BIT_KEY_INITIALIZER(word, bit);
+
if (waitqueue_active(wq_head))
__wake_up(wq_head, TASK_NORMAL, 1, &key);
}
}
EXPORT_SYMBOL(wake_up_bit);
-/*
- * Manipulate the atomic_t address to produce a better bit waitqueue table hash
- * index (we're keying off bit -1, but that would produce a horrible hash
- * value).
- */
-static inline wait_queue_head_t *atomic_t_waitqueue(atomic_t *p)
+wait_queue_head_t *__var_waitqueue(void *p)
{
- if (BITS_PER_LONG == 64) {
- unsigned long q = (unsigned long)p;
- return bit_waitqueue((void *)(q & ~1), q & 1);
- }
- return bit_waitqueue(p, 0);
+ return bit_wait_table + hash_ptr(p, WAIT_TABLE_BITS);
}
+EXPORT_SYMBOL(__var_waitqueue);
-static int wake_atomic_t_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync,
- void *arg)
+static int
+var_wake_function(struct wait_queue_entry *wq_entry, unsigned int mode,
+ int sync, void *arg)
{
struct wait_bit_key *key = arg;
- struct wait_bit_queue_entry *wait_bit = container_of(wq_entry, struct wait_bit_queue_entry, wq_entry);
- atomic_t *val = key->flags;
+ struct wait_bit_queue_entry *wbq_entry =
+ container_of(wq_entry, struct wait_bit_queue_entry, wq_entry);
- if (wait_bit->key.flags != key->flags ||
- wait_bit->key.bit_nr != key->bit_nr ||
- atomic_read(val) != 0)
+ if (wbq_entry->key.flags != key->flags ||
+ wbq_entry->key.bit_nr != key->bit_nr)
return 0;
- return autoremove_wake_function(wq_entry, mode, sync, key);
-}
-/*
- * To allow interruptible waiting and asynchronous (i.e. nonblocking) waiting,
- * the actions of __wait_on_atomic_t() are permitted return codes. Nonzero
- * return codes halt waiting and return.
- */
-static __sched
-int __wait_on_atomic_t(struct wait_queue_head *wq_head, struct wait_bit_queue_entry *wbq_entry,
- wait_atomic_t_action_f action, unsigned int mode)
-{
- atomic_t *val;
- int ret = 0;
-
- do {
- prepare_to_wait(wq_head, &wbq_entry->wq_entry, mode);
- val = wbq_entry->key.flags;
- if (atomic_read(val) == 0)
- break;
- ret = (*action)(val, mode);
- } while (!ret && atomic_read(val) != 0);
- finish_wait(wq_head, &wbq_entry->wq_entry);
- return ret;
+ return autoremove_wake_function(wq_entry, mode, sync, key);
}
-#define DEFINE_WAIT_ATOMIC_T(name, p) \
- struct wait_bit_queue_entry name = { \
- .key = __WAIT_ATOMIC_T_KEY_INITIALIZER(p), \
- .wq_entry = { \
- .private = current, \
- .func = wake_atomic_t_function, \
- .entry = \
- LIST_HEAD_INIT((name).wq_entry.entry), \
- }, \
- }
-
-__sched int out_of_line_wait_on_atomic_t(atomic_t *p,
- wait_atomic_t_action_f action,
- unsigned int mode)
+void init_wait_var_entry(struct wait_bit_queue_entry *wbq_entry, void *var, int flags)
{
- struct wait_queue_head *wq_head = atomic_t_waitqueue(p);
- DEFINE_WAIT_ATOMIC_T(wq_entry, p);
-
- return __wait_on_atomic_t(wq_head, &wq_entry, action, mode);
+ *wbq_entry = (struct wait_bit_queue_entry){
+ .key = {
+ .flags = (var),
+ .bit_nr = -1,
+ },
+ .wq_entry = {
+ .private = current,
+ .func = var_wake_function,
+ .entry = LIST_HEAD_INIT(wbq_entry->wq_entry.entry),
+ },
+ };
}
-EXPORT_SYMBOL(out_of_line_wait_on_atomic_t);
+EXPORT_SYMBOL(init_wait_var_entry);
-__sched int atomic_t_wait(atomic_t *counter, unsigned int mode)
+void wake_up_var(void *var)
{
- schedule();
- if (signal_pending_state(mode, current))
- return -EINTR;
- return 0;
+ __wake_up_bit(__var_waitqueue(var), var, -1);
}
-EXPORT_SYMBOL(atomic_t_wait);
-
-/**
- * wake_up_atomic_t - Wake up a waiter on a atomic_t
- * @p: The atomic_t being waited on, a kernel virtual address
- *
- * Wake up anyone waiting for the atomic_t to go to zero.
- *
- * Abuse the bit-waker function and its waitqueue hash table set (the atomic_t
- * check is done by the waiter's wake function, not the by the waker itself).
- */
-void wake_up_atomic_t(atomic_t *p)
-{
- __wake_up_bit(atomic_t_waitqueue(p), p, WAIT_ATOMIC_T_BIT_NR);
-}
-EXPORT_SYMBOL(wake_up_atomic_t);
+EXPORT_SYMBOL(wake_up_var);
__sched int bit_wait(struct wait_bit_key *word, int mode)
{
schedule();
if (signal_pending_state(mode, current))
return -EINTR;
+
return 0;
}
EXPORT_SYMBOL(bit_wait);
io_schedule();
if (signal_pending_state(mode, current))
return -EINTR;
+
return 0;
}
EXPORT_SYMBOL(bit_wait_io);
__sched int bit_wait_timeout(struct wait_bit_key *word, int mode)
{
unsigned long now = READ_ONCE(jiffies);
+
if (time_after_eq(now, word->timeout))
return -EAGAIN;
schedule_timeout(word->timeout - now);
if (signal_pending_state(mode, current))
return -EINTR;
+
return 0;
}
EXPORT_SYMBOL_GPL(bit_wait_timeout);
__sched int bit_wait_io_timeout(struct wait_bit_key *word, int mode)
{
unsigned long now = READ_ONCE(jiffies);
+
if (time_after_eq(now, word->timeout))
return -EAGAIN;
io_schedule_timeout(word->timeout - now);
if (signal_pending_state(mode, current))
return -EINTR;
+
return 0;
}
EXPORT_SYMBOL_GPL(bit_wait_io_timeout);
git.samba.org / sfrench / cifs-2.6.git / blobdiff