[mirror_ubuntu-zesty-kernel.git] / include / linux / poll.h

#ifndef _LINUX_POLL_H
#define _LINUX_POLL_H

#include <asm/poll.h>

#ifdef __KERNEL__

#include <linux/compiler.h>
#include <linux/wait.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <asm/uaccess.h>

/* ~832 bytes of stack space used max in sys_select/sys_poll before allocating
   additional memory. */
#define MAX_STACK_ALLOC 832
#define FRONTEND_STACK_ALLOC	256
#define SELECT_STACK_ALLOC	FRONTEND_STACK_ALLOC
#define POLL_STACK_ALLOC	FRONTEND_STACK_ALLOC
#define WQUEUES_STACK_ALLOC	(MAX_STACK_ALLOC - FRONTEND_STACK_ALLOC)
#define N_INLINE_POLL_ENTRIES	(WQUEUES_STACK_ALLOC / sizeof(struct poll_table_entry))

struct poll_table_struct;

/* 
 * structures and helpers for f_op->poll implementations
 */
typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *);

typedef struct poll_table_struct {
	poll_queue_proc qproc;
} poll_table;

static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
{
	if (p && wait_address)
		p->qproc(filp, wait_address, p);
}

static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
{
	pt->qproc = qproc;
}

struct poll_table_entry {
	struct file * filp;
	wait_queue_t wait;
	wait_queue_head_t * wait_address;
};

/*
 * Structures and helpers for sys_poll/sys_poll
 */
struct poll_wqueues {
	poll_table pt;
	struct poll_table_page * table;
	int error;
	int inline_index;
	struct poll_table_entry inline_entries[N_INLINE_POLL_ENTRIES];
};

extern void poll_initwait(struct poll_wqueues *pwq);
extern void poll_freewait(struct poll_wqueues *pwq);

/*
 * Scaleable version of the fd_set.
 */

typedef struct {
	unsigned long *in, *out, *ex;
	unsigned long *res_in, *res_out, *res_ex;
} fd_set_bits;

/*
 * How many longwords for "nr" bits?
 */
#define FDS_BITPERLONG	(8*sizeof(long))
#define FDS_LONGS(nr)	(((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG)
#define FDS_BYTES(nr)	(FDS_LONGS(nr)*sizeof(long))

/*
 * We do a VERIFY_WRITE here even though we are only reading this time:
 * we'll write to it eventually..
 *
 * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned.
 */
static inline
int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
{
	nr = FDS_BYTES(nr);
	if (ufdset)
		return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0;

	memset(fdset, 0, nr);
	return 0;
}

static inline unsigned long __must_check
set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
{
	if (ufdset)
		return __copy_to_user(ufdset, fdset, FDS_BYTES(nr));
	return 0;
}

static inline
void zero_fd_set(unsigned long nr, unsigned long *fdset)
{
	memset(fdset, 0, FDS_BYTES(nr));
}

#define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1)

extern int do_select(int n, fd_set_bits *fds, s64 *timeout);
extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds,
		       s64 *timeout);

#endif /* KERNEL */

#endif /* _LINUX_POLL_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef _LINUX_POLL_H
	2	#define _LINUX_POLL_H
	3
	4	#include <asm/poll.h>
	5
	6	#ifdef __KERNEL__
	7
	8	#include <linux/compiler.h>
	9	#include <linux/wait.h>
	10	#include <linux/string.h>
	11	#include <linux/mm.h>
	12	#include <asm/uaccess.h>
	13
70674f95 AK	14	/* ~832 bytes of stack space used max in sys_select/sys_poll before allocating
	15	additional memory. */
	16	#define MAX_STACK_ALLOC 832
	17	#define FRONTEND_STACK_ALLOC 256
	18	#define SELECT_STACK_ALLOC FRONTEND_STACK_ALLOC
	19	#define POLL_STACK_ALLOC FRONTEND_STACK_ALLOC
	20	#define WQUEUES_STACK_ALLOC (MAX_STACK_ALLOC - FRONTEND_STACK_ALLOC)
	21	#define N_INLINE_POLL_ENTRIES (WQUEUES_STACK_ALLOC / sizeof(struct poll_table_entry))
	22
1da177e4 LT	23	struct poll_table_struct;
	24
	25	/*
	26	* structures and helpers for f_op->poll implementations
	27	*/
	28	typedef void (poll_queue_proc)(struct file , wait_queue_head_t , struct poll_table_struct );
	29
	30	typedef struct poll_table_struct {
	31	poll_queue_proc qproc;
	32	} poll_table;
	33
	34	static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
	35	{
	36	if (p && wait_address)
	37	p->qproc(filp, wait_address, p);
	38	}
	39
	40	static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
	41	{
	42	pt->qproc = qproc;
	43	}
	44
70674f95 AK	45	struct poll_table_entry {
	46	struct file * filp;
	47	wait_queue_t wait;
	48	wait_queue_head_t * wait_address;
	49	};
	50
1da177e4 LT	51	/*
	52	* Structures and helpers for sys_poll/sys_poll
	53	*/
	54	struct poll_wqueues {
	55	poll_table pt;
	56	struct poll_table_page * table;
	57	int error;
70674f95 AK	58	int inline_index;
70674f95 AK	59	struct poll_table_entry inline_entries[N_INLINE_POLL_ENTRIES];
1da177e4 LT	60	};
	61
	62	extern void poll_initwait(struct poll_wqueues *pwq);
	63	extern void poll_freewait(struct poll_wqueues *pwq);
	64
	65	/*
	66	* Scaleable version of the fd_set.
	67	*/
	68
	69	typedef struct {
	70	unsigned long in, out, *ex;
	71	unsigned long res_in, res_out, *res_ex;
	72	} fd_set_bits;
	73
	74	/*
	75	* How many longwords for "nr" bits?
	76	*/
	77	#define FDS_BITPERLONG (8*sizeof(long))
	78	#define FDS_LONGS(nr) (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG)
	79	#define FDS_BYTES(nr) (FDS_LONGS(nr)*sizeof(long))
	80
	81	/*
	82	* We do a VERIFY_WRITE here even though we are only reading this time:
	83	* we'll write to it eventually..
	84	*
	85	* Use "unsigned long" accesses to let user-mode fd_set's be long-aligned.
	86	*/
	87	static inline
	88	int get_fd_set(unsigned long nr, void __user ufdset, unsigned long fdset)
	89	{
	90	nr = FDS_BYTES(nr);
	91	if (ufdset)
	92	return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0;
	93
	94	memset(fdset, 0, nr);
	95	return 0;
	96	}
	97
	98	static inline unsigned long __must_check
	99	set_fd_set(unsigned long nr, void __user ufdset, unsigned long fdset)
	100	{
	101	if (ufdset)
	102	return __copy_to_user(ufdset, fdset, FDS_BYTES(nr));
	103	return 0;
	104	}
	105
	106	static inline
	107	void zero_fd_set(unsigned long nr, unsigned long *fdset)
	108	{
	109	memset(fdset, 0, FDS_BYTES(nr));
	110	}
	111
9f72949f DW	112	#define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1)
	113
	114	extern int do_select(int n, fd_set_bits fds, s64 timeout);
	115	extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds,
	116	s64 *timeout);
1da177e4 LT	117
	118	#endif /* KERNEL */
	119
	120	#endif /* _LINUX_POLL_H */