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, s64 *timeout); 118 extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds, 119 s64 *timeout); 120 121 #endif /* KERNEL */ 122 123 #endif /* _LINUX_POLL_H */ 124