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 struct poll_table_struct; 25 26 /* 27 * structures and helpers for f_op->poll implementations 28 */ 29 typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *); 30 31 typedef struct poll_table_struct { 32 poll_queue_proc qproc; 33 } poll_table; 34 35 static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p) 36 { 37 if (p && wait_address) 38 p->qproc(filp, wait_address, p); 39 } 40 41 static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc) 42 { 43 pt->qproc = qproc; 44 } 45 46 struct poll_table_entry { 47 struct file * filp; 48 wait_queue_t wait; 49 wait_queue_head_t * wait_address; 50 }; 51 52 /* 53 * Structures and helpers for sys_poll/sys_poll 54 */ 55 struct poll_wqueues { 56 poll_table pt; 57 struct poll_table_page * table; 58 int error; 59 int inline_index; 60 struct poll_table_entry inline_entries[N_INLINE_POLL_ENTRIES]; 61 }; 62 63 extern void poll_initwait(struct poll_wqueues *pwq); 64 extern void poll_freewait(struct poll_wqueues *pwq); 65 66 /* 67 * Scaleable version of the fd_set. 68 */ 69 70 typedef struct { 71 unsigned long *in, *out, *ex; 72 unsigned long *res_in, *res_out, *res_ex; 73 } fd_set_bits; 74 75 /* 76 * How many longwords for "nr" bits? 77 */ 78 #define FDS_BITPERLONG (8*sizeof(long)) 79 #define FDS_LONGS(nr) (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG) 80 #define FDS_BYTES(nr) (FDS_LONGS(nr)*sizeof(long)) 81 82 /* 83 * We do a VERIFY_WRITE here even though we are only reading this time: 84 * we'll write to it eventually.. 85 * 86 * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned. 87 */ 88 static inline 89 int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset) 90 { 91 nr = FDS_BYTES(nr); 92 if (ufdset) 93 return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0; 94 95 memset(fdset, 0, nr); 96 return 0; 97 } 98 99 static inline unsigned long __must_check 100 set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset) 101 { 102 if (ufdset) 103 return __copy_to_user(ufdset, fdset, FDS_BYTES(nr)); 104 return 0; 105 } 106 107 static inline 108 void zero_fd_set(unsigned long nr, unsigned long *fdset) 109 { 110 memset(fdset, 0, FDS_BYTES(nr)); 111 } 112 113 #define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1) 114 115 extern int do_select(int n, fd_set_bits *fds, s64 *timeout); 116 extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds, 117 s64 *timeout); 118 119 #endif /* KERNEL */ 120 121 #endif /* _LINUX_POLL_H */ 122