1 /*
   2  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   3  * Use is subject to license terms.
   4  */
   5 /*
   6  * \file drm_atomic.h
   7  * Atomic operations used in the DRM which may or may not be provided by the OS.
   8  *
   9  * \author Eric Anholt <anholt@FreeBSD.org>
  10  */
  11 
  12 /*
  13  * Copyright 2004 Eric Anholt
  14  * Copyright (c) 2009, Intel Corporation.
  15  * All Rights Reserved.
  16  *
  17  * Permission is hereby granted, free of charge, to any person obtaining a
  18  * copy of this software and associated documentation files (the "Software"),
  19  * to deal in the Software without restriction, including without limitation
  20  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  21  * and/or sell copies of the Software, and to permit persons to whom the
  22  * Software is furnished to do so, subject to the following conditions:
  23  *
  24  * The above copyright notice and this permission notice (including the next
  25  * paragraph) shall be included in all copies or substantial portions of the
  26  * Software.
  27  *
  28  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  29  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  30  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  31  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  32  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  33  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  34  * OTHER DEALINGS IN THE SOFTWARE.
  35  */
  36 
  37 /* Many of these implementations are rather fake, but good enough. */
  38 
  39 
  40 
  41 #ifndef _SYS_DRM_ATOMIC_H_
  42 #define _SYS_DRM_ATOMIC_H_
  43 
  44 #ifdef  __cplusplus
  45 extern "C" {
  46 #endif
  47 
  48 #include <sys/atomic.h>
  49 
  50 #ifdef __LINT__
  51 #undef inline
  52 #define inline
  53 #endif
  54 typedef uint32_t        atomic_t;
  55 
  56 #define atomic_set(p, v)        (*(p) = (v))
  57 #define atomic_read(p)          (*(p))
  58 #define atomic_inc(p)           atomic_add_int(p, 1)
  59 #define atomic_dec(p)           atomic_dec_uint(p)
  60 #define atomic_add(n, p)        atomic_add_int(p, n)
  61 #define atomic_sub(n, p)        atomic_add_int(p, -n)
  62 #define atomic_set_int(p, bits) atomic_or_uint(p, bits)
  63 #define atomic_clear_int(p, bits)       atomic_and_uint(p, ~(bits))
  64 #define atomic_cmpset_int(p, c, n) \
  65         ((c == atomic_cas_uint(p, c, n)) ? 1 : 0)
  66 
  67 #define set_bit(b, p) \
  68         atomic_set_int(((volatile uint_t *)(void *)p) + (b >> 5), \
  69         1 << (b & 0x1f))
  70 
  71 #define clear_bit(b, p) \
  72         atomic_clear_int(((volatile uint_t *)(void *)p) + (b >> 5), \
  73         1 << (b & 0x1f))
  74 
  75 #define test_bit(b, p) \
  76         (((volatile uint_t *)(void *)p)[b >> 5] & (1 << (b & 0x1f)))
  77 
  78 /*
  79  * Note: this routine doesn't return old value. It return
  80  * 0 when succeeds, or -1 when fails.
  81  */
  82 #ifdef _LP64
  83 #define test_and_set_bit(b, p) \
  84         atomic_set_long_excl(((ulong_t *)(void *)p) + (b >> 6), (b & 0x3f))
  85 #else
  86 #define test_and_set_bit(b, p) \
  87         atomic_set_long_excl(((ulong_t *)(void *)p) + (b >> 5), (b & 0x1f))
  88 #endif
  89 
  90 #ifdef  __cplusplus
  91 }
  92 #endif
  93 
  94 #endif /* _SYS_DRM_ATOMIC_H_ */