Subversion Repositories HelenOS

Rev

Rev 1702 | Rev 1888 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
153 jermar 1
/*
2
 * Copyright (C) 2005 Jakub Jermar
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
 *
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - 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
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
28
 
1702 cejka 29
 /** @addtogroup ia32  
30
 * @{
31
 */
32
/** @file
33
 */
34
 
153 jermar 35
#ifndef __ia32_BARRIER_H__
36
#define __ia32_BARRIER_H__
37
 
38
/*
39
 * NOTE:
40
 * No barriers for critical section (i.e. spinlock) on IA-32 are needed:
41
 * - spinlock_lock() and spinlock_trylock() use serializing XCHG instruction
42
 * - writes cannot pass reads on IA-32 => spinlock_unlock() needs no barriers
43
 */
44
 
45
/*
46
 * Provisions are made to prevent compiler from reordering instructions itself.
47
 */
48
 
49
#define CS_ENTER_BARRIER()  __asm__ volatile ("" ::: "memory")
50
#define CS_LEAVE_BARRIER()  __asm__ volatile ("" ::: "memory")
51
 
469 jermar 52
static inline void cpuid_serialization(void)
53
{
54
    __asm__ volatile (
55
        "xorl %%eax, %%eax\n"
56
        "cpuid\n"
57
        ::: "eax", "ebx", "ecx", "edx", "memory"
58
    );
59
}
60
 
468 decky 61
#ifdef CONFIG_FENCES_P4
470 jermar 62
#   define memory_barrier()     __asm__ volatile ("mfence\n" ::: "memory")
468 decky 63
#   define read_barrier()       __asm__ volatile ("lfence\n" ::: "memory")
470 jermar 64
#   ifdef CONFIG_WEAK_MEMORY
65
#       define write_barrier()  __asm__ volatile ("sfence\n" ::: "memory")
66
#   else
1434 palkovsky 67
#       define write_barrier()  __asm__ volatile( "" ::: "memory");
470 jermar 68
#   endif
468 decky 69
#elif CONFIG_FENCES_P3
469 jermar 70
#   define memory_barrier()     cpuid_serialization()
71
#   define read_barrier()       cpuid_serialization()
470 jermar 72
#   ifdef CONFIG_WEAK_MEMORY
73
#       define write_barrier()  __asm__ volatile ("sfence\n" ::: "memory")
74
#   else
1434 palkovsky 75
#       define write_barrier()  __asm__ volatile( "" ::: "memory");
470 jermar 76
#   endif
469 jermar 77
#else
78
#   define memory_barrier()     cpuid_serialization()
79
#   define read_barrier()       cpuid_serialization()
470 jermar 80
#   ifdef CONFIG_WEAK_MEMORY
81
#       define write_barrier()  cpuid_serialization()
82
#   else
1434 palkovsky 83
#       define write_barrier()  __asm__ volatile( "" ::: "memory");
470 jermar 84
#   endif
153 jermar 85
#endif
423 decky 86
 
87
#endif
1702 cejka 88
 
89
 /** @}
90
 */
91