sys/sys/idr.h

   1 /*
   2  * Copyright (c) 2005-2012 The DragonFly Project.
   3  * Copyright (c) 2013 François Tigeot
   4  * All rights reserved.
   5  *
   6  * This code is derived from software contributed to The DragonFly Project
   7  * by Jeffrey Hsu.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  * 3. Neither the name of The DragonFly Project nor the names of its
  20  *    contributors may be used to endorse or promote products derived
  21  *    from this software without specific, prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  24  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  26  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  27  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  28  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  29  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  30  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  31  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  32  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  33  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  */
  37
  38 /**
  39  * IDR is a small Integer ID management library that provides an interface to
  40  * map integers with some pointer that can later be retrieved.
  41  *
  42  * NOTE: Pointer mapped by integer can't be NULL.
  43  *
  44  */
  45
  46
  47 #ifndef _IDR_H_
  48 #define _IDR_H_
  49
  50 #ifdef _KERNEL
  51
  52 #include <sys/thread.h>
  53
  54 #ifndef GFP_KERNEL
  55 #include <sys/malloc.h>
  56 #define GFP_KERNEL      M_WAITOK
  57 #endif
  58
  59 struct idr_node {
  60         void    *data;
  61         int      allocated;
  62 };
  63
  64 struct idr {
  65         struct      idr_node *idr_nodes;
  66         int         idr_count;
  67         int         idr_lastindex;
  68         int         idr_freeindex;
  69         int         idr_nexpands;
  70         int         idr_maxwant;
  71         struct lwkt_token idr_token;
  72 };
  73
  74 void    *idr_find(struct idr *idp, int id);
  75 void    *idr_replace(struct idr *idp, void *ptr, int id);
  76 void     idr_remove(struct idr *idp, int id);
  77 void     idr_remove_all(struct idr *idp);
  78 void     idr_destroy(struct idr *idp);
  79 int      idr_for_each(struct idr *idp, int (*fn)(int id, void *p, void *data), void *data);
  80 int      idr_get_new(struct idr *idp, void *ptr, int *id);
  81 int      idr_get_new_above(struct idr *idp, void *ptr, int sid, int *id);
  82 int      idr_pre_get(struct idr *idp, unsigned gfp_mask);
  83
  84 void     idr_init(struct idr *idp);
  85
  86 int idr_alloc(struct idr *idp, void *ptr, int start, int end, unsigned gfp_mask);
  87
  88 static inline void idr_preload(unsigned gfp_mask)
  89 {
  90         /* Linux disables preemption and allocates a per-cpu buffer here */
  91 }
  92
  93 static inline void idr_preload_end(void)
  94 {
  95         /* Linux re-enables preemption here */
  96 }
  97
  98 #endif /* _KERNEL */
  99
 100 #endif /* _IDR_H_ */