LXR RHEL5/ipc/util.h

   1/*
   2 * linux/ipc/util.h
   3 * Copyright (C) 1999 Christoph Rohland
   4 *
   5 * ipc helper functions (c) 1999 Manfred Spraul <manfred@colorfullife.com>
   6 */
   7
   8#ifndef _IPC_UTIL_H
   9#define _IPC_UTIL_H
  10
  11#define USHRT_MAX 0xffff
  12#define SEQ_MULTIPLIER  (IPCMNI)
  13
  14void sem_init (void);
  15void msg_init (void);
  16void shm_init (void);
  17
  18struct ipc_id_ary {
  19        int size;
  20        struct kern_ipc_perm *p[0];
  21};
  22
  23struct ipc_ids {
  24        int in_use;
  25        int max_id;
  26        unsigned short seq;
  27        unsigned short seq_max;
  28        struct mutex mutex;
  29        struct ipc_id_ary nullentry;
  30        struct ipc_id_ary* entries;
  31};
  32
  33struct seq_file;
  34void __init ipc_init_ids(struct ipc_ids* ids, int size);
  35#ifdef CONFIG_PROC_FS
  36void __init ipc_init_proc_interface(const char *path, const char *header,
  37                                    struct ipc_ids *ids,
  38                                    int (*show)(struct seq_file *, void *));
  39#else
  40#define ipc_init_proc_interface(path, header, ids, show) do {} while (0)
  41#endif
  42
  43/* must be called with ids->mutex acquired.*/
  44int ipc_findkey(struct ipc_ids* ids, key_t key);
  45int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size);
  46
  47/* must be called with both locks acquired. */
  48struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id);
  49
  50int ipcperms (struct kern_ipc_perm *ipcp, short flg);
  51
  52/* for rare, potentially huge allocations.
  53 * both function can sleep
  54 */
  55void* ipc_alloc(int size);
  56void ipc_free(void* ptr, int size);
  57
  58/*
  59 * For allocation that need to be freed by RCU.
  60 * Objects are reference counted, they start with reference count 1.
  61 * getref increases the refcount, the putref call that reduces the recount
  62 * to 0 schedules the rcu destruction. Caller must guarantee locking.
  63 */
  64void* ipc_rcu_alloc(int size);
  65void ipc_rcu_getref(void *ptr);
  66void ipc_rcu_putref(void *ptr);
  67
  68struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id);
  69struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id);
  70void ipc_lock_by_ptr(struct kern_ipc_perm *ipcp);
  71void ipc_unlock(struct kern_ipc_perm* perm);
  72int ipc_buildid(struct ipc_ids* ids, int id, int seq);
  73int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid);
  74
  75void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
  76void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
  77
  78#if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__)
  79  /* On IA-64, we always use the "64-bit version" of the IPC structures.  */ 
  80# define ipc_parse_version(cmd) IPC_64
  81#else
  82int ipc_parse_version (int *cmd);
  83#endif
  84
  85extern void free_msg(struct msg_msg *msg);
  86extern struct msg_msg *load_msg(const void __user *src, int len);
  87extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
  88
  89#endif
  90