X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;ds=sidebyside;f=include%2Flinux%2Fwait.h;h=ddb0a16f31c9161be2456c7e919043d20f28e18c;hb=6a77f38946aaee1cd85eeec6cf4229b204c15071;hp=21cd4df67b241845cbc71bd6c8997d52b4938c8d;hpb=87fc8d1bb10cd459024a742c6a10961fefcef18f;p=linux-2.6.git

diff --git a/include/linux/wait.h b/include/linux/wait.h
index 21cd4df67..ddb0a16f3 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -24,6 +24,7 @@
 #include <linux/stddef.h>
 #include <linux/spinlock.h>
 #include <asm/system.h>
+#include <asm/current.h>
 
 typedef struct __wait_queue wait_queue_t;
 typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int sync, void *key);
@@ -37,6 +38,16 @@ struct __wait_queue {
 	struct list_head task_list;
 };
 
+struct wait_bit_key {
+	void *flags;
+	int bit_nr;
+};
+
+struct wait_bit_queue {
+	struct wait_bit_key key;
+	wait_queue_t wait;
+};
+
 struct __wait_queue_head {
 	spinlock_t lock;
 	struct list_head task_list;
@@ -63,6 +74,9 @@ typedef struct __wait_queue_head wait_queue_head_t;
 #define DECLARE_WAIT_QUEUE_HEAD(name) \
 	wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
 
+#define __WAIT_BIT_KEY_INITIALIZER(word, bit)				\
+	{ .flags = word, .bit_nr = bit, }
+
 static inline void init_waitqueue_head(wait_queue_head_t *q)
 {
 	q->lock = SPIN_LOCK_UNLOCKED;
@@ -125,11 +139,17 @@ static inline void __remove_wait_queue(wait_queue_head_t *head,
 void FASTCALL(__wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key));
 extern void FASTCALL(__wake_up_locked(wait_queue_head_t *q, unsigned int mode));
 extern void FASTCALL(__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr));
+void FASTCALL(__wake_up_bit(wait_queue_head_t *, void *, int));
+int FASTCALL(__wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned));
+int FASTCALL(__wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned));
+void FASTCALL(wake_up_bit(void *, int));
+int FASTCALL(out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned));
+int FASTCALL(out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned));
+wait_queue_head_t *FASTCALL(bit_waitqueue(void *, int));
 
 #define wake_up(x)			__wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 1, NULL)
 #define wake_up_nr(x, nr)		__wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, nr, NULL)
 #define wake_up_all(x)			__wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 0, NULL)
-#define wake_up_all_sync(x)			__wake_up_sync((x),TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 0)
 #define wake_up_interruptible(x)	__wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
 #define wake_up_interruptible_nr(x, nr)	__wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
 #define wake_up_interruptible_all(x)	__wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
@@ -300,22 +320,80 @@ void FASTCALL(prepare_to_wait_exclusive(wait_queue_head_t *q,
 				wait_queue_t *wait, int state));
 void FASTCALL(finish_wait(wait_queue_head_t *q, wait_queue_t *wait));
 int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
+int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
 
 #define DEFINE_WAIT(name)						\
 	wait_queue_t name = {						\
 		.task		= current,				\
 		.func		= autoremove_wake_function,		\
-		.task_list	= {	.next = &name.task_list,	\
-					.prev = &name.task_list,	\
+		.task_list	= {	.next = &(name).task_list,	\
+					.prev = &(name).task_list,	\
 				},					\
 	}
 
+#define DEFINE_WAIT_BIT(name, word, bit)				\
+	struct wait_bit_queue name = {					\
+		.key = __WAIT_BIT_KEY_INITIALIZER(word, bit),		\
+		.wait	= {						\
+			.task		= current,			\
+			.func		= wake_bit_function,		\
+			.task_list	=				\
+				LIST_HEAD_INIT((name).wait.task_list),	\
+		},							\
+	}
+
 #define init_wait(wait)							\
 	do {								\
-		wait->task = current;					\
-		wait->func = autoremove_wake_function;			\
-		INIT_LIST_HEAD(&wait->task_list);			\
+		(wait)->task = current;					\
+		(wait)->func = autoremove_wake_function;		\
+		INIT_LIST_HEAD(&(wait)->task_list);			\
 	} while (0)
+
+/**
+ * wait_on_bit - wait for a bit to be cleared
+ * @word: the word being waited on, a kernel virtual address
+ * @bit: the bit of the word being waited on
+ * @action: the function used to sleep, which may take special actions
+ * @mode: the task state to sleep in
+ *
+ * There is a standard hashed waitqueue table for generic use. This
+ * is the part of the hashtable's accessor API that waits on a bit.
+ * For instance, if one were to have waiters on a bitflag, one would
+ * call wait_on_bit() in threads waiting for the bit to clear.
+ * One uses wait_on_bit() where one is waiting for the bit to clear,
+ * but has no intention of setting it.
+ */
+static inline int wait_on_bit(void *word, int bit,
+				int (*action)(void *), unsigned mode)
+{
+	if (!test_bit(bit, word))
+		return 0;
+	return out_of_line_wait_on_bit(word, bit, action, mode);
+}
+
+/**
+ * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
+ * @word: the word being waited on, a kernel virtual address
+ * @bit: the bit of the word being waited on
+ * @action: the function used to sleep, which may take special actions
+ * @mode: the task state to sleep in
+ *
+ * There is a standard hashed waitqueue table for generic use. This
+ * is the part of the hashtable's accessor API that waits on a bit
+ * when one intends to set it, for instance, trying to lock bitflags.
+ * For instance, if one were to have waiters trying to set bitflag
+ * and waiting for it to clear before setting it, one would call
+ * wait_on_bit() in threads waiting to be able to set the bit.
+ * One uses wait_on_bit_lock() where one is waiting for the bit to
+ * clear with the intention of setting it, and when done, clearing it.
+ */
+static inline int wait_on_bit_lock(void *word, int bit,
+				int (*action)(void *), unsigned mode)
+{
+	if (!test_and_set_bit(bit, word))
+		return 0;
+	return out_of_line_wait_on_bit_lock(word, bit, action, mode);
+}
 	
 #endif /* __KERNEL__ */