[linux-2.6-block.git] / include / uapi / linux / futex.h

#ifndef _UAPI_LINUX_FUTEX_H
#define _UAPI_LINUX_FUTEX_H

#include <linux/compiler.h>
#include <linux/types.h>

/* Second argument to futex syscall */


#define FUTEX_WAIT		0
#define FUTEX_WAKE		1
#define FUTEX_FD		2
#define FUTEX_REQUEUE		3
#define FUTEX_CMP_REQUEUE	4
#define FUTEX_WAKE_OP		5
#define FUTEX_LOCK_PI		6
#define FUTEX_UNLOCK_PI		7
#define FUTEX_TRYLOCK_PI	8
#define FUTEX_WAIT_BITSET	9
#define FUTEX_WAKE_BITSET	10
#define FUTEX_WAIT_REQUEUE_PI	11
#define FUTEX_CMP_REQUEUE_PI	12

#define FUTEX_PRIVATE_FLAG	128
#define FUTEX_CLOCK_REALTIME	256
#define FUTEX_CMD_MASK		~(FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME)

#define FUTEX_WAIT_PRIVATE	(FUTEX_WAIT | FUTEX_PRIVATE_FLAG)
#define FUTEX_WAKE_PRIVATE	(FUTEX_WAKE | FUTEX_PRIVATE_FLAG)
#define FUTEX_REQUEUE_PRIVATE	(FUTEX_REQUEUE | FUTEX_PRIVATE_FLAG)
#define FUTEX_CMP_REQUEUE_PRIVATE (FUTEX_CMP_REQUEUE | FUTEX_PRIVATE_FLAG)
#define FUTEX_WAKE_OP_PRIVATE	(FUTEX_WAKE_OP | FUTEX_PRIVATE_FLAG)
#define FUTEX_LOCK_PI_PRIVATE	(FUTEX_LOCK_PI | FUTEX_PRIVATE_FLAG)
#define FUTEX_UNLOCK_PI_PRIVATE	(FUTEX_UNLOCK_PI | FUTEX_PRIVATE_FLAG)
#define FUTEX_TRYLOCK_PI_PRIVATE (FUTEX_TRYLOCK_PI | FUTEX_PRIVATE_FLAG)
#define FUTEX_WAIT_BITSET_PRIVATE	(FUTEX_WAIT_BITSET | FUTEX_PRIVATE_FLAG)
#define FUTEX_WAKE_BITSET_PRIVATE	(FUTEX_WAKE_BITSET | FUTEX_PRIVATE_FLAG)
#define FUTEX_WAIT_REQUEUE_PI_PRIVATE	(FUTEX_WAIT_REQUEUE_PI | \
					 FUTEX_PRIVATE_FLAG)
#define FUTEX_CMP_REQUEUE_PI_PRIVATE	(FUTEX_CMP_REQUEUE_PI | \
					 FUTEX_PRIVATE_FLAG)

/*
 * Support for robust futexes: the kernel cleans up held futexes at
 * thread exit time.
 */

/*
 * Per-lock list entry - embedded in user-space locks, somewhere close
 * to the futex field. (Note: user-space uses a double-linked list to
 * achieve O(1) list add and remove, but the kernel only needs to know
 * about the forward link)
 *
 * NOTE: this structure is part of the syscall ABI, and must not be
 * changed.
 */
struct robust_list {
	struct robust_list __user *next;
};

/*
 * Per-thread list head:
 *
 * NOTE: this structure is part of the syscall ABI, and must only be
 * changed if the change is first communicated with the glibc folks.
 * (When an incompatible change is done, we'll increase the structure
 *  size, which glibc will detect)
 */
struct robust_list_head {
	/*
	 * The head of the list. Points back to itself if empty:
	 */
	struct robust_list list;

	/*
	 * This relative offset is set by user-space, it gives the kernel
	 * the relative position of the futex field to examine. This way
	 * we keep userspace flexible, to freely shape its data-structure,
	 * without hardcoding any particular offset into the kernel:
	 */
	long futex_offset;

	/*
	 * The death of the thread may race with userspace setting
	 * up a lock's links. So to handle this race, userspace first
	 * sets this field to the address of the to-be-taken lock,
	 * then does the lock acquire, and then adds itself to the
	 * list, and then clears this field. Hence the kernel will
	 * always have full knowledge of all locks that the thread
	 * _might_ have taken. We check the owner TID in any case,
	 * so only truly owned locks will be handled.
	 */
	struct robust_list __user *list_op_pending;
};

/*
 * Are there any waiters for this robust futex:
 */
#define FUTEX_WAITERS		0x80000000

/*
 * The kernel signals via this bit that a thread holding a futex
 * has exited without unlocking the futex. The kernel also does
 * a FUTEX_WAKE on such futexes, after setting the bit, to wake
 * up any possible waiters:
 */
#define FUTEX_OWNER_DIED	0x40000000

/*
 * The rest of the robust-futex field is for the TID:
 */
#define FUTEX_TID_MASK		0x3fffffff

/*
 * This limit protects against a deliberately circular list.
 * (Not worth introducing an rlimit for it)
 */
#define ROBUST_LIST_LIMIT	2048

/*
 * bitset with all bits set for the FUTEX_xxx_BITSET OPs to request a
 * match of any bit.
 */
#define FUTEX_BITSET_MATCH_ANY	0xffffffff


#define FUTEX_OP_SET		0	/* *(int *)UADDR2 = OPARG; */
#define FUTEX_OP_ADD		1	/* *(int *)UADDR2 += OPARG; */
#define FUTEX_OP_OR		2	/* *(int *)UADDR2 |= OPARG; */
#define FUTEX_OP_ANDN		3	/* *(int *)UADDR2 &= ~OPARG; */
#define FUTEX_OP_XOR		4	/* *(int *)UADDR2 ^= OPARG; */

#define FUTEX_OP_OPARG_SHIFT	8	/* Use (1 << OPARG) instead of OPARG.  */

#define FUTEX_OP_CMP_EQ		0	/* if (oldval == CMPARG) wake */
#define FUTEX_OP_CMP_NE		1	/* if (oldval != CMPARG) wake */
#define FUTEX_OP_CMP_LT		2	/* if (oldval < CMPARG) wake */
#define FUTEX_OP_CMP_LE		3	/* if (oldval <= CMPARG) wake */
#define FUTEX_OP_CMP_GT		4	/* if (oldval > CMPARG) wake */
#define FUTEX_OP_CMP_GE		5	/* if (oldval >= CMPARG) wake */

/* FUTEX_WAKE_OP will perform atomically
   int oldval = *(int *)UADDR2;
   *(int *)UADDR2 = oldval OP OPARG;
   if (oldval CMP CMPARG)
     wake UADDR2;  */

#define FUTEX_OP(op, oparg, cmp, cmparg) \
  (((op & 0xf) << 28) | ((cmp & 0xf) << 24)		\
   | ((oparg & 0xfff) << 12) | (cmparg & 0xfff))

#endif /* _UAPI_LINUX_FUTEX_H */
Commit	Line	Data
607ca46e DH	1	#ifndef _UAPI_LINUX_FUTEX_H
	2	#define _UAPI_LINUX_FUTEX_H
	3
	4	#include <linux/compiler.h>
	5	#include <linux/types.h>
	6
	7	/* Second argument to futex syscall */
	8
	9
	10	#define FUTEX_WAIT 0
	11	#define FUTEX_WAKE 1
	12	#define FUTEX_FD 2
	13	#define FUTEX_REQUEUE 3
	14	#define FUTEX_CMP_REQUEUE 4
	15	#define FUTEX_WAKE_OP 5
	16	#define FUTEX_LOCK_PI 6
	17	#define FUTEX_UNLOCK_PI 7
	18	#define FUTEX_TRYLOCK_PI 8
	19	#define FUTEX_WAIT_BITSET 9
	20	#define FUTEX_WAKE_BITSET 10
	21	#define FUTEX_WAIT_REQUEUE_PI 11
	22	#define FUTEX_CMP_REQUEUE_PI 12
	23
	24	#define FUTEX_PRIVATE_FLAG 128
	25	#define FUTEX_CLOCK_REALTIME 256
	26	#define FUTEX_CMD_MASK ~(FUTEX_PRIVATE_FLAG \| FUTEX_CLOCK_REALTIME)
	27
	28	#define FUTEX_WAIT_PRIVATE (FUTEX_WAIT \| FUTEX_PRIVATE_FLAG)
	29	#define FUTEX_WAKE_PRIVATE (FUTEX_WAKE \| FUTEX_PRIVATE_FLAG)
	30	#define FUTEX_REQUEUE_PRIVATE (FUTEX_REQUEUE \| FUTEX_PRIVATE_FLAG)
	31	#define FUTEX_CMP_REQUEUE_PRIVATE (FUTEX_CMP_REQUEUE \| FUTEX_PRIVATE_FLAG)
	32	#define FUTEX_WAKE_OP_PRIVATE (FUTEX_WAKE_OP \| FUTEX_PRIVATE_FLAG)
	33	#define FUTEX_LOCK_PI_PRIVATE (FUTEX_LOCK_PI \| FUTEX_PRIVATE_FLAG)
	34	#define FUTEX_UNLOCK_PI_PRIVATE (FUTEX_UNLOCK_PI \| FUTEX_PRIVATE_FLAG)
	35	#define FUTEX_TRYLOCK_PI_PRIVATE (FUTEX_TRYLOCK_PI \| FUTEX_PRIVATE_FLAG)
	36	#define FUTEX_WAIT_BITSET_PRIVATE (FUTEX_WAIT_BITSET \| FUTEX_PRIVATE_FLAG)
	37	#define FUTEX_WAKE_BITSET_PRIVATE (FUTEX_WAKE_BITSET \| FUTEX_PRIVATE_FLAG)
	38	#define FUTEX_WAIT_REQUEUE_PI_PRIVATE (FUTEX_WAIT_REQUEUE_PI \| \
	39	FUTEX_PRIVATE_FLAG)
	40	#define FUTEX_CMP_REQUEUE_PI_PRIVATE (FUTEX_CMP_REQUEUE_PI \| \
	41	FUTEX_PRIVATE_FLAG)
	42
	43	/*
	44	* Support for robust futexes: the kernel cleans up held futexes at
	45	* thread exit time.
	46	*/
	47
	48	/*
	49	* Per-lock list entry - embedded in user-space locks, somewhere close
	50	* to the futex field. (Note: user-space uses a double-linked list to
	51	* achieve O(1) list add and remove, but the kernel only needs to know
	52	* about the forward link)
	53	*
	54	* NOTE: this structure is part of the syscall ABI, and must not be
	55	* changed.
	56	*/
	57	struct robust_list {
	58	struct robust_list __user *next;
	59	};
	60
	61	/*
	62	* Per-thread list head:
	63	*
	64	* NOTE: this structure is part of the syscall ABI, and must only be
65	* changed if the change is first communicated with the glibc folks.
66	* (When an incompatible change is done, we'll increase the structure
67	* size, which glibc will detect)
68	*/
69	struct robust_list_head {
70	/*
71	* The head of the list. Points back to itself if empty:
72	*/
73	struct robust_list list;
74
75	/*
76	* This relative offset is set by user-space, it gives the kernel
77	* the relative position of the futex field to examine. This way
78	* we keep userspace flexible, to freely shape its data-structure,
79	* without hardcoding any particular offset into the kernel:
80	*/
81	long futex_offset;
82
83	/*
84	* The death of the thread may race with userspace setting
85	* up a lock's links. So to handle this race, userspace first
86	* sets this field to the address of the to-be-taken lock,
87	* then does the lock acquire, and then adds itself to the
88	* list, and then clears this field. Hence the kernel will
89	* always have full knowledge of all locks that the thread
90	* _might_ have taken. We check the owner TID in any case,
91	* so only truly owned locks will be handled.
92	*/
93	struct robust_list __user *list_op_pending;
94	};
95
96	/*
97	* Are there any waiters for this robust futex:
98	*/
99	#define FUTEX_WAITERS 0x80000000
100
101	/*
102	* The kernel signals via this bit that a thread holding a futex
103	* has exited without unlocking the futex. The kernel also does
104	* a FUTEX_WAKE on such futexes, after setting the bit, to wake
105	* up any possible waiters:
106	*/
107	#define FUTEX_OWNER_DIED 0x40000000
108
109	/*
110	* The rest of the robust-futex field is for the TID:
111	*/
112	#define FUTEX_TID_MASK 0x3fffffff
113
114	/*
115	* This limit protects against a deliberately circular list.
116	* (Not worth introducing an rlimit for it)
117	*/
118	#define ROBUST_LIST_LIMIT 2048
119
120	/*
121	* bitset with all bits set for the FUTEX_xxx_BITSET OPs to request a
122	* match of any bit.
123	*/
124	#define FUTEX_BITSET_MATCH_ANY 0xffffffff
125
126
127	#define FUTEX_OP_SET 0 /* (int )UADDR2 = OPARG; */
128	#define FUTEX_OP_ADD 1 /* (int )UADDR2 += OPARG; */
129	#define FUTEX_OP_OR 2 /* (int )UADDR2 \|= OPARG; */
130	#define FUTEX_OP_ANDN 3 /* (int )UADDR2 &= ~OPARG; */
131	#define FUTEX_OP_XOR 4 /* (int )UADDR2 ^= OPARG; */
132
133	#define FUTEX_OP_OPARG_SHIFT 8 /* Use (1 << OPARG) instead of OPARG. */
134
135	#define FUTEX_OP_CMP_EQ 0 /* if (oldval == CMPARG) wake */
136	#define FUTEX_OP_CMP_NE 1 /* if (oldval != CMPARG) wake */
137	#define FUTEX_OP_CMP_LT 2 /* if (oldval < CMPARG) wake */
138	#define FUTEX_OP_CMP_LE 3 /* if (oldval <= CMPARG) wake */
139	#define FUTEX_OP_CMP_GT 4 /* if (oldval > CMPARG) wake */
140	#define FUTEX_OP_CMP_GE 5 /* if (oldval >= CMPARG) wake */
141
142	/* FUTEX_WAKE_OP will perform atomically
143	int oldval = (int )UADDR2;
144	(int )UADDR2 = oldval OP OPARG;
145	if (oldval CMP CMPARG)
146	wake UADDR2; */
147
148	#define FUTEX_OP(op, oparg, cmp, cmparg) \
149	(((op & 0xf) << 28) \| ((cmp & 0xf) << 24) \
150	\| ((oparg & 0xfff) << 12) \| (cmparg & 0xfff))
151
152	#endif /* _UAPI_LINUX_FUTEX_H */