0,0 → 1,98 |
# |
# Copyright (C) 2001-2004 Jakub Jermar |
# All rights reserved. |
# |
# Redistribution and use in source and binary forms, with or without |
# modification, are permitted provided that the following conditions |
# are met: |
# |
# - Redistributions of source code must retain the above copyright |
# notice, this list of conditions and the following disclaimer. |
# - Redistributions in binary form must reproduce the above copyright |
# notice, this list of conditions and the following disclaimer in the |
# documentation and/or other materials provided with the distribution. |
# - The name of the author may not be used to endorse or promote products |
# derived from this software without specific prior written permission. |
# |
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
# |
|
.text |
|
.global atomic_inc |
atomic_inc: |
pushl %ebx |
movl 8(%esp),%ebx |
#ifdef __SMP__ |
lock incl (%ebx) |
#else |
incl (%ebx) |
#endif |
popl %ebx |
ret |
|
.global atomic_dec |
atomic_dec: |
pushl %ebx |
movl 8(%esp),%ebx |
#ifdef __SMP__ |
lock decl (%ebx) |
#else |
decl (%ebx) |
#endif |
popl %ebx |
ret |
|
|
#ifdef __SMP__ |
|
|
.global test_and_set |
.global spinlock_arch |
|
test_and_set: |
pushl %ebx |
|
movl 8(%esp),%ebx |
movl $1,%eax |
xchgl %eax,(%ebx) # xchg implicitly turns on the LOCK signal |
|
popl %ebx |
ret |
|
|
# |
# This is a bus-and-hyperthreading-friendly implementation of spinlock |
# |
spinlock_arch: |
pushl %eax |
pushl %ebx |
|
movl 12(%esp),%ebx |
|
0: |
#ifdef __HT__ |
pause # Pentium 4's with HT love this instruction |
#endif |
movl (%ebx),%eax |
testl %eax,%eax |
jnz 0b # lightweight looping while it is locked |
incl %eax |
xchgl %eax,(%ebx) # now use the atomic operation |
testl %eax,%eax |
jnz 0b |
|
popl %ebx |
popl %eax |
ret |
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#endif |