1/* 2 * Copyright © 2009 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 * 23 * Authors: 24 * Chris Wilson <chris@chris-wilson.co.uk> 25 * 26 */ 27 28/** 29 * @file xf86atomics.h 30 * 31 * Private definitions for atomic operations 32 */ 33 34#ifndef LIBDRM_ATOMICS_H 35#define LIBDRM_ATOMICS_H 36 37#ifdef HAVE_CONFIG_H 38#include "config.h" 39#endif 40 41#if HAVE_LIBDRM_ATOMIC_PRIMITIVES 42 43#define HAS_ATOMIC_OPS 1 44 45typedef struct { 46 int atomic; 47} atomic_t; 48 49# define atomic_read(x) ((x)->atomic) 50# define atomic_set(x, val) ((x)->atomic = (val)) 51# define atomic_inc(x) ((void) __sync_fetch_and_add (&(x)->atomic, 1)) 52# define atomic_inc_return(x) (__sync_add_and_fetch (&(x)->atomic, 1)) 53# define atomic_dec_and_test(x) (__sync_add_and_fetch (&(x)->atomic, -1) == 0) 54# define atomic_add(x, v) ((void) __sync_add_and_fetch(&(x)->atomic, (v))) 55# define atomic_dec(x, v) ((void) __sync_sub_and_fetch(&(x)->atomic, (v))) 56# define atomic_cmpxchg(x, oldv, newv) __sync_val_compare_and_swap (&(x)->atomic, oldv, newv) 57 58#endif 59 60#if HAVE_LIB_ATOMIC_OPS 61#include <atomic_ops.h> 62 63#define HAS_ATOMIC_OPS 1 64 65typedef struct { 66 AO_t atomic; 67} atomic_t; 68 69# define atomic_read(x) AO_load_full(&(x)->atomic) 70# define atomic_set(x, val) AO_store_full(&(x)->atomic, (val)) 71# define atomic_inc(x) ((void) AO_fetch_and_add1_full(&(x)->atomic)) 72# define atomic_inc_return(x) (AO_fetch_and_add1_full(&(x)->atomic) + 1) 73# define atomic_add(x, v) ((void) AO_fetch_and_add_full(&(x)->atomic, (v))) 74# define atomic_dec(x, v) ((void) AO_fetch_and_add_full(&(x)->atomic, -(v))) 75# define atomic_dec_and_test(x) (AO_fetch_and_sub1_full(&(x)->atomic) == 1) 76# define atomic_cmpxchg(x, oldv, newv) AO_compare_and_swap_full(&(x)->atomic, oldv, newv) 77 78#endif 79 80#if (defined(__sun) || defined(__NetBSD__)) && !defined(HAS_ATOMIC_OPS) /* Solaris & OpenSolaris & NetBSD */ 81 82#include <sys/atomic.h> 83#define HAS_ATOMIC_OPS 1 84 85#if defined(__NetBSD__) 86#define LIBDRM_ATOMIC_TYPE int 87#else 88#define LIBDRM_ATOMIC_TYPE uint_t 89#endif 90 91typedef struct { LIBDRM_ATOMIC_TYPE atomic; } atomic_t; 92 93# define atomic_read(x) (int) ((x)->atomic) 94# define atomic_set(x, val) ((x)->atomic = (LIBDRM_ATOMIC_TYPE)(val)) 95# define atomic_inc(x) (atomic_inc_uint (&(x)->atomic)) 96# define atomic_inc_return(x) (atomic_inc_uint_nv(&(x)->atomic)) 97# define atomic_dec_and_test(x) (atomic_dec_uint_nv(&(x)->atomic) == 0) 98# define atomic_add(x, v) (atomic_add_int(&(x)->atomic, (v))) 99# define atomic_dec(x, v) (atomic_add_int(&(x)->atomic, -(v))) 100# define atomic_cmpxchg(x, oldv, newv) atomic_cas_uint (&(x)->atomic, oldv, newv) 101 102#endif 103 104#if ! HAS_ATOMIC_OPS 105#error libdrm requires atomic operations, please define them for your CPU/compiler. 106#endif 107 108static inline int atomic_add_unless(atomic_t *v, int add, int unless) 109{ 110 int c, old; 111 c = atomic_read(v); 112 while (c != unless && (old = atomic_cmpxchg(v, c, c + add)) != c) 113 c = old; 114 return c == unless; 115} 116 117#endif 118