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/ktime.h> 10 #include <linux/wait.h> 11 #include <linux/string.h> 12 #include <linux/fs.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 unsigned long key; 36 } poll_table; 37 38 static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p) 39 { 40 if (p && wait_address) 41 p->qproc(filp, wait_address, p); 42 } 43 44 static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc) 45 { 46 pt->qproc = qproc; 47 pt->key = ~0UL; /* all events enabled */ 48 } 49 50 struct poll_table_entry { 51 struct file *filp; 52 unsigned long key; 53 wait_queue_t wait; 54 wait_queue_head_t *wait_address; 55 }; 56 57 /* 58 * Structures and helpers for sys_poll/sys_poll 59 */ 60 struct poll_wqueues { 61 poll_table pt; 62 struct poll_table_page *table; 63 struct task_struct *polling_task; 64 int triggered; 65 int error; 66 int inline_index; 67 struct poll_table_entry inline_entries[N_INLINE_POLL_ENTRIES]; 68 }; 69 70 extern void poll_initwait(struct poll_wqueues *pwq); 71 extern void poll_freewait(struct poll_wqueues *pwq); 72 extern int poll_schedule_timeout(struct poll_wqueues *pwq, int state, 73 ktime_t *expires, unsigned long slack); 74 75 static inline int poll_schedule(struct poll_wqueues *pwq, int state) 76 { 77 return poll_schedule_timeout(pwq, state, NULL, 0); 78 } 79 80 /* 81 * Scaleable version of the fd_set. 82 */ 83 84 typedef struct { 85 unsigned long *in, *out, *ex; 86 unsigned long *res_in, *res_out, *res_ex; 87 } fd_set_bits; 88 89 /* 90 * How many longwords for "nr" bits? 91 */ 92 #define FDS_BITPERLONG (8*sizeof(long)) 93 #define FDS_LONGS(nr) (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG) 94 #define FDS_BYTES(nr) (FDS_LONGS(nr)*sizeof(long)) 95 96 /* 97 * We do a VERIFY_WRITE here even though we are only reading this time: 98 * we'll write to it eventually.. 99 * 100 * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned. 101 */ 102 static inline 103 int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset) 104 { 105 nr = FDS_BYTES(nr); 106 if (ufdset) 107 return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0; 108 109 memset(fdset, 0, nr); 110 return 0; 111 } 112 113 static inline unsigned long __must_check 114 set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset) 115 { 116 if (ufdset) 117 return __copy_to_user(ufdset, fdset, FDS_BYTES(nr)); 118 return 0; 119 } 120 121 static inline 122 void zero_fd_set(unsigned long nr, unsigned long *fdset) 123 { 124 memset(fdset, 0, FDS_BYTES(nr)); 125 } 126 127 #define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1) 128 129 extern int do_select(int n, fd_set_bits *fds, struct timespec *end_time); 130 extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds, 131 struct timespec *end_time); 132 extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp, 133 fd_set __user *exp, struct timespec *end_time); 134 135 extern int poll_select_set_timeout(struct timespec *to, long sec, long nsec); 136 137 #endif /* KERNEL */ 138 139 #endif /* _LINUX_POLL_H */ 140