Subversion Repositories HelenOS-historic

Rev

Rev 1434 | 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