sys/dev/drm/include/linux/idr.h

   1 /*
   2  * Copyright (c) 2013-2016 François Tigeot
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice unmodified, this list of conditions, and the following
  10  *    disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #ifndef _LINUX_IDR_H_
  28 #define _LINUX_IDR_H_
  29
  30 #include <sys/idr.h>
  31
  32 MALLOC_DECLARE(M_IDR);
  33
  34 #define IDA_CHUNK_SIZE          128     /* 128 bytes per chunk */
  35 #define IDA_BITMAP_LONGS        (IDA_CHUNK_SIZE / sizeof(long) - 1)
  36 #define IDA_BITMAP_BITS         (IDA_BITMAP_LONGS * sizeof(long) * 8)
  37
  38 struct ida_bitmap {
  39         long                    nr_busy;
  40         unsigned long           bitmap[IDA_BITMAP_LONGS];
  41 };
  42
  43 struct ida {
  44         struct idr              idr;
  45         struct ida_bitmap       *free_bitmap;
  46 };
  47
  48 static inline void
  49 ida_init(struct ida *ida)
  50 {
  51         idr_init(&ida->idr);
  52 }
  53
  54 static inline void
  55 ida_simple_remove(struct ida *ida, unsigned int id)
  56 {
  57         idr_remove(&ida->idr, id);
  58 }
  59
  60 static inline void
  61 ida_remove(struct ida *ida, int id)
  62 {
  63         idr_remove(&ida->idr, id);
  64 }
  65
  66 static inline void
  67 ida_destroy(struct ida *ida)
  68 {
  69         idr_destroy(&ida->idr);
  70         if (ida->free_bitmap != NULL) {
  71                 /* kfree() is a linux macro! Work around the cpp pass */
  72                 (kfree)(ida->free_bitmap, M_IDR);
  73         }
  74 }
  75
  76 static inline int
  77 ida_simple_get(struct ida *ida, unsigned int start, unsigned int end, gfp_t gfp_mask)
  78 {
  79         int id;
  80         unsigned int lim;
  81
  82         if ((end == 0) || (end > 0x80000000))
  83                 lim = 0x80000000;
  84         else
  85                 lim = end - 1;
  86
  87         idr_preload(gfp_mask);
  88         id = idr_alloc(&ida->idr, NULL, start, lim, gfp_mask);
  89         idr_preload_end();
  90
  91         return id;
  92 }
  93
  94 #endif  /* _LINUX_IDR_H_ */