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      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 (at) 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 #if HAVE_LIBDRM_ATOMIC_PRIMITIVES
     38 
     39 #define HAS_ATOMIC_OPS 1
     40 
     41 typedef struct {
     42 	int atomic;
     43 } atomic_t;
     44 
     45 # define atomic_read(x) ((x)->atomic)
     46 # define atomic_set(x, val) ((x)->atomic = (val))
     47 # define atomic_inc(x) ((void) __sync_fetch_and_add (&(x)->atomic, 1))
     48 # define atomic_inc_return(x) (__sync_add_and_fetch (&(x)->atomic, 1))
     49 # define atomic_dec_and_test(x) (__sync_add_and_fetch (&(x)->atomic, -1) == 0)
     50 # define atomic_add(x, v) ((void) __sync_add_and_fetch(&(x)->atomic, (v)))
     51 # define atomic_dec(x, v) ((void) __sync_sub_and_fetch(&(x)->atomic, (v)))
     52 # define atomic_cmpxchg(x, oldv, newv) __sync_val_compare_and_swap (&(x)->atomic, oldv, newv)
     53 
     54 #endif
     55 
     56 #if HAVE_LIB_ATOMIC_OPS
     57 #define AO_REQUIRE_CAS
     58 #include <atomic_ops.h>
     59 
     60 #define HAS_ATOMIC_OPS 1
     61 
     62 typedef struct {
     63 	AO_t atomic;
     64 } atomic_t;
     65 
     66 # define atomic_read(x) AO_load_full(&(x)->atomic)
     67 # define atomic_set(x, val) AO_store_full(&(x)->atomic, (val))
     68 # define atomic_inc(x) ((void) AO_fetch_and_add1_full(&(x)->atomic))
     69 # define atomic_inc_return(x) (AO_fetch_and_add1_full(&(x)->atomic) + 1)
     70 # define atomic_add(x, v) ((void) AO_fetch_and_add_full(&(x)->atomic, (v)))
     71 # define atomic_dec(x, v) ((void) AO_fetch_and_add_full(&(x)->atomic, -(v)))
     72 # define atomic_dec_and_test(x) (AO_fetch_and_sub1_full(&(x)->atomic) == 1)
     73 # define atomic_cmpxchg(x, oldv, newv) AO_compare_and_swap_full(&(x)->atomic, oldv, newv)
     74 
     75 #endif
     76 
     77 #if (defined(__sun) || defined(__NetBSD__)) && !defined(HAS_ATOMIC_OPS)  /* Solaris & OpenSolaris & NetBSD */
     78 
     79 #include <sys/atomic.h>
     80 #define HAS_ATOMIC_OPS 1
     81 
     82 #if defined(__NetBSD__)
     83 #define LIBDRM_ATOMIC_TYPE unsigned int
     84 #else
     85 #define LIBDRM_ATOMIC_TYPE uint_t
     86 #endif
     87 
     88 typedef struct { volatile LIBDRM_ATOMIC_TYPE atomic; } atomic_t;
     89 
     90 # define atomic_read(x) (int) ((x)->atomic)
     91 # define atomic_set(x, val) ((x)->atomic = (LIBDRM_ATOMIC_TYPE)(val))
     92 # define atomic_inc(x) (atomic_inc_uint (&(x)->atomic))
     93 # define atomic_inc_return(x) (atomic_inc_uint_nv(&(x)->atomic))
     94 # define atomic_dec_and_test(x) (atomic_dec_uint_nv(&(x)->atomic) == 0)
     95 # define atomic_add(x, v) (atomic_add_int(&(x)->atomic, (v)))
     96 # define atomic_dec(x, v) (atomic_add_int(&(x)->atomic, -(v)))
     97 # define atomic_cmpxchg(x, oldv, newv) atomic_cas_uint (&(x)->atomic, oldv, newv)
     98 
     99 #endif
    100 
    101 #if !defined(HAS_ATOMIC_OPS)
    102 #error libdrm requires atomic operations, please define them for your CPU/compiler.
    103 #endif
    104 
    105 static inline int atomic_add_unless(atomic_t *v, int add, int unless)
    106 {
    107 	int c, old;
    108 	c = atomic_read(v);
    109 	while (c != unless && (old = atomic_cmpxchg(v, c, c + add)) != c)
    110 		c = old;
    111 	return c != unless;
    112 }
    113 
    114 #endif
    115