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/fs.h>

    12 #include <linux/sched.h>

    13 #include <asm/uaccess.h>

    14 

    15 /* ~832 bytes of stack space used max in sys_select/sys_poll before allocating

    16    additional memory. */

    17 #define MAX_STACK_ALLOC 832

    18 #define FRONTEND_STACK_ALLOC	256

    19 #define SELECT_STACK_ALLOC	FRONTEND_STACK_ALLOC

    20 #define POLL_STACK_ALLOC	FRONTEND_STACK_ALLOC

    21 #define WQUEUES_STACK_ALLOC	(MAX_STACK_ALLOC - FRONTEND_STACK_ALLOC)

    22 #define N_INLINE_POLL_ENTRIES	(WQUEUES_STACK_ALLOC / sizeof(struct poll_table_entry))

    23 

    24 #define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)

    25 

    26 struct poll_table_struct;

    27 

    28 /* 

    29  * structures and helpers for f_op->poll implementations

    30  */

    31 typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *);

    32 

    33 typedef struct poll_table_struct {

    34 	poll_queue_proc qproc;

    35 } poll_table;

    36 

    37 static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)

    38 {

    39 	if (p && wait_address)

    40 		p->qproc(filp, wait_address, p);

    41 }

    42 

    43 static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)

    44 {

    45 	pt->qproc = qproc;

    46 }

    47 

    48 struct poll_table_entry {

    49 	struct file * filp;

    50 	wait_queue_t wait;

    51 	wait_queue_head_t * wait_address;

    52 };

    53 

    54 /*

    55  * Structures and helpers for sys_poll/sys_poll

    56  */

    57 struct poll_wqueues {

    58 	poll_table pt;

    59 	struct poll_table_page * table;

    60 	int error;

    61 	int inline_index;

    62 	struct poll_table_entry inline_entries[N_INLINE_POLL_ENTRIES];

    63 };

    64 

    65 extern void poll_initwait(struct poll_wqueues *pwq);

    66 extern void poll_freewait(struct poll_wqueues *pwq);

    67 

    68 /*

    69  * Scaleable version of the fd_set.

    70  */

    71 

    72 typedef struct {

    73 	unsigned long *in, *out, *ex;

    74 	unsigned long *res_in, *res_out, *res_ex;

    75 } fd_set_bits;

    76 

    77 /*

    78  * How many longwords for "nr" bits?

    79  */

    80 #define FDS_BITPERLONG	(8*sizeof(long))

    81 #define FDS_LONGS(nr)	(((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG)

    82 #define FDS_BYTES(nr)	(FDS_LONGS(nr)*sizeof(long))

    83 

    84 /*

    85  * We do a VERIFY_WRITE here even though we are only reading this time:

    86  * we'll write to it eventually..

    87  *

    88  * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned.

    89  */

    90 static inline

    91 int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)

    92 {

    93 	nr = FDS_BYTES(nr);

    94 	if (ufdset)

    95 		return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0;

    96 

    97 	memset(fdset, 0, nr);

    98 	return 0;

    99 }

   100 

   101 static inline unsigned long __must_check

   102 set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)

   103 {

   104 	if (ufdset)

   105 		return __copy_to_user(ufdset, fdset, FDS_BYTES(nr));

   106 	return 0;

   107 }

   108 

   109 static inline

   110 void zero_fd_set(unsigned long nr, unsigned long *fdset)

   111 {

   112 	memset(fdset, 0, FDS_BYTES(nr));

   113 }

   114 

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

   116 

   117 extern int do_select(int n, fd_set_bits *fds, struct timespec *end_time);

   118 extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds,

   119 		       struct timespec *end_time);

   120 extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,

   121 			   fd_set __user *exp, struct timespec *end_time);

   122 

   123 extern int poll_select_set_timeout(struct timespec *to, long sec, long nsec);

   124 

   125 #endif /* KERNEL */

   126 

   127 #endif /* _LINUX_POLL_H */